Reduced carnitine level causes death from hypoglycemia: possible involvement of suppression of hypothalamic orexin expression during weaning period.

The mechanism of onset of hypoglycemia in patients with carnitine deficiency has yet to be determined. Using mice with systemic carnitine deficiency (JVS mice), we examined this mechanism, focusing on the weaning period (days 14-28 postpartum). For normal mice, the survival rate was 100%, and no hypoglycemia was observed at all. Gastric lactose began to decrease on day 17, and cellulose increased sharply in amount thereafter. For JVS mice, the survival rate was 77% on day 14 and 28% on day 28. From day 21 on, hypoglycemia was noted. Gastric lactose had disappeared almost completely by day 17, and cellulose was almost undetectable from days 14 to 28. Expression of orexin mRNA in the hypothalamus did not differ between JVS and normal mice on day 14, but was suppressed in JVS mice on days 21 and 28. When JVS mice were fed a carnitine-rich diet, suppression of expression of orexin mRNA in hypothalamus was eliminated, and on day 28 lactose and cellulose were detected in the stomach without hypoglycemia. In conclusion, the suppression of the expression of orexin in the hypothalamus during the weaning period may be involved in the marked anorexia in JVS mice, which eventually leads to death from hypoglycemia.


Identification and analysis of the promoter region of the type II transmembrane serine protease polyserase-1 and its transcript variants

Polyserase-1/TMPRSS9 and its alternative transcripts, serase-1B and serase-2B, are novel type II transmembrane serine proteases that may regulate physiological and pathological phenomena on the cell surface. To understand the mechanisms of gene expression and regulation of these transcripts, we cloned and characterized the 5' promoter region of the mouse polyserase-1 (mpolyserase-1) gene. Using 5'-rapid amplification of cDNA ends, we located the transcription initiation site 272 nucleotides upstream of the translation initiation site. Luciferase reporter gene analysis revealed that the region from +186 to +272 bp in the 5'-untranslated region (UTR), containing the GATA motif (AGATAA), glucocorticoid responsible element (TGTTCT), and E-box sequence (CAGGTG), is required for maximal promoter activity. Mutations introduced into the E-box sequence but not elsewhere in the promoter region caused a selective decrease in transcriptional activity. Furthermore, a DNA probe (+229 to +255 bp) containing the E-box sequence formed a single nuclear protein complex in a sequence-specific manner. These data suggest that the expression of mpolyserase-1 and its transcript variants is positively regulated by the E-box in its 5'-UTR, which might be responsible for the binding of basic helix-loop-helix transcription factors involved in the development of various organelles.


Gatekeeper Role of 14-3-3τ Protein in HIV-1 gp120-Mediated Apotosis of Human Endothelial Cells by Inactivation of Bad

HIV-1-associated dementia (HAD) is a major neurological complication often observed in the advanced stages of AIDS. We have reported that 14-3-3 proteins in cerebrospinal fluid, reflecting neuronal cell destruction, is a real-time marker of HAD progression. This study was designed to examine the role of 14-3-3 proteins in HAD. An in-vitro human umbilical vein endothelial cells (HUVEC) model of gp120 protein-induced apoptosis to study the protective role of 14-3-3 in HIV-1 gp120/CXCR4-mediated cell death. The alpha-chemokine receptor-mediated cell death by HIV-1 envelope protein, gp120, the critical event that causes neuron loss and endothelial cell injury, was evaluated in HUVEC undergoing gp120-induced apoptosis through the CXCR4 receptor. We studied the effects of siRNA for each 14-3-3 isoform on the death of HUVEC treated with CXCR4-preferring gp120 (IIIB). Gp120 increased the expression of 14-3-3tau in HUVEC. The binding of Gp120 to CXCR4 induced apoptosis of HUVEC through decreased binding of 14-3-3tau to the pro-apoptotic molecule, Bad. Treatment of the cells with dsRNA against 14-3-3tau enhanced the gp120-mediated dephosphorylation of Bad and its association with Bcl-XL in mitochondria, accelerating the gp120-induced apoptosis, whereas suppression of Bad by RNAi rescued the cells from apoptosis triggered by gp120. The specific up-regulation of 14-3-3tau in HUVEC negatively regulated gp120/CXCR4-mediated cell death by protecting Bad dephosphorylation.


Proteases Essential for Human Influenza Virus Entry into Cells and Their Inhibitors as Potential Therapeutic Agents

Influenza A virus (IAV) is one of the most common infectious pathogens in humans. Since IVA genome does not have the processing protease for the viral membrane fusion glycoprotein precursors, entry of this virus into cells is determined primarily by host cellular, trypsin-type, processing proteases that proteolytically activate the fusion glycoprotein precursors of IAV. At least five different processing proteases have been identified in the airways of animals and humans. These proteases determine the infectious organ tropism of IAV infection as well as the efficiency of viral multiplication in the airway, and sometimes in the brain. Proteases in the upper respiratory tract are suppressed by secretory leukoprotease inhibitor, and those in the lower respiratory tract are suppressed by pulmonary surfactant which, by adsorption, inhibits the interaction between the proteases and viral membrane proteins. Since protease activities predominate over those of endogenous inhibitory compounds under normal airway conditions, administration of protease inhibitors in the early-stage of infection significantly suppresses viral entry and viral multiplication. Several viral neuraminidase inhibitors are used clinically as anti-influenza virus agents, based on their inhibitory action on viral release from infected cells. Furthermore, protease inhibitors of viral entry could be potentially useful against influenza virus as well as neuraminidase inhibitor-resistant viruses. We also found that ambroxol, a mucolytic and anti-oxidant agent, up-regulates the levels of endogenous protease inhibitory compounds in the airway fluids in early-phase infection, and that clarithromycin, a macrolide antibiotic, increases IgA levels and mucosal immunity through augmentation of interleukin-12 levels in the airway. The combination of neuraminidase inhibitors and protease inhibitors, clarithromycin or ambroxol, could be potentially used as a potent anti-influenza therapy to minimize the emergence of drug-resistant mutant viruses.


Serase-1B, a new splice variant of polyserase-1/TMPRSS9, activates urokinase-type plasminogen activator and the proteolytic activation is negatively regulated by glycosaminoglycans.

Polyserase-1 (polyserine protease-1)/TMPRSS9 (transmembrane serine protease 9) is a type II transmembrane serine protease (TTSP) that possesses unique three tandem serine protease domains. However, the physiological function of each protease domain remains poorly understood. We discovered a new splice variant of polyserase-1, termed Serase-1B, which contains 34 extra amino acids consisting a SEA module (a domain found in sea urchin sperm protein, enterokinase and agrin) adjacent to the transmembrane domain and the first protease domain with a mucin-like box at the C-terminus. The tissue distribution of this enzyme by RT (reverse transcription)-PCR analysis revealed high expression in the liver, small intestine, pancreas, testis and peripheral blood CD14+ and CD8+ cells. To investigate the role of Serase-1B, a full-length form recombinant protein was produced. Interestingly, recombinant Serase-1B was partly secreted as a soluble inactive precursor and it was also activated by trypsin. This activated enzyme selectively cleaved synthetic peptides for trypsin and activated protein C, and it was inhibited by several natural serine protease inhibitors, such as aprotinin, alpha2-antiplasmin and plasminogen activator inhibitor 1. In addition, Serase-1B efficiently converted pro-uPA (urokinase-type plasminogen activator) into active uPA and this activation was strongly inhibited by these natural inhibitors. Furthermore, this activation was also negatively regulated by glycosaminoglycans. Our results indicate that Serase-1B is a novel member of TTSPs that might be involved in uPA/plasmin-mediated proteolysis and possibly implicated in biological events such as fibrinolysis and tumour progression.


[Introduction of proteomic approach to environmental medicine].

環境医学領域におけるプロテオミクスの導入

Recent progress in life science technology and the availability of much information on genes obtained by genome analysis has enabled us to analyze the changes of proteins on a large scale. Sets of proteins are called proteomes, and proteomics is the scientific field of proteome analysis including differential, post translational modification and interaction analyses. Various proteomic techniques, particularly two-dimensional gel electrophoresis (2-DE), mass spectrometry, protein chip methods, and surface plasmon resonance (SPR), are very useful for acquiring proteomes in cells, tissues and body fluid, and for analyzing interactions between a protein and other biofactors including proteins. A proteomic approach is also useful for determining biomarkers of diseases and key proteins involved in various stages of metabolism such as differentiation, cell cycle and apoptosis. Environmental pollutants including endocrine disruptors inhibit activities of various organs in wild animals and humans. Proteomic approaches could be very useful tools for elucidating the mechanisms of damage caused by environmental pollutants. In this review, we describe the application of a proteomic approach to the field of environmental medicine.


Physiological roles of the type II transmembrane serine protease

広がりを見せるプロテアーゼファミリー,II型膜結合型セリンプロテアーゼの生理機能


Impaired long-chain fatty acid metabolism in mitochondria causes brain vascular invasion by a non-neurotropic epidemic influenza A virus in the newborn/suckling period: implications for influenza-associated encephalopathy

The neuropathogenesis of influenza-associated encephalopathy in children and Reye's syndrome remains unclear. A surveillance effort conducted during 2000-2003 in South-West Japan reveals that almost all fatal and handicapped influenza-associated encephalopathy patients exhibit a disorder of mitochondrial beta-oxidation with elevated serum acylcarnitine ratios (C(16:0)+C(18:1))/C(2). Here we show invasion by a non-neurotropic epidemic influenza A H3N2 virus in cerebral capillaries with progressive brain edema after intranasal infection of mice having impaired mitochondrial beta-oxidation congenitally or posteriorly in the newborn/ suckling periods. Mice genetically lacking of carnitine transporter OCTN2, resulting in carnitine deficiency and impaired beta-oxidation, exhibited significant higher virus-genome numbers in the brain, accumulation of virus antigen exclusively in the cerebral capillaries and increased brain vascular permeability compared to in wild type mice. Mini-plasmin, which proteolytically potentiates influenza virus multiplication in vivo and destroys the blood-brain barrier, accumulated with virus antigen in the brain capillaries of OCTN2-deficient mice but only a little in wild-type mice. These results suggest that the impaired mitochondrial beta-oxidation changes the susceptibility to a non-neurotropic influenza A virus as to multiplication in the brain capillaries and to cause brain edema. These pathological findings in the brain of mice having impaired mitochondrial beta-oxidation after influenza virus infection may have implications for human influenza-associated encephalopathy.


Fab fragment labeled with ICG-derivative for detecting digestive tract cancer


肺サーファクタントの粘膜アジュバント作用

肺サーファクタントの粘膜アジュバント作用


A novel function of 14-3-3 protein: 14-3-3z is a heat shock-related molecular chaperone that dissolves thermal-aggregated proteins

The 14-3-3 proteins are highly conserved molecules that function as intracellular adaptors in a variety of biological processes, such as signal transduction, cell cycle control, and apoptosis. Here, we show that a 14-3-3 protein is a heat-shock protein (Hsp) that protects cells against physiological stress as its new cellular function. We have observed that, in Drosophila cells, the 14-3-3zeta is up-regulated under heat stress conditions, a process mediated by a heat shock transcription factor. As the biological action linked to heat stress, 14-3-3zeta interacted with apocytochrome c, a mitochondrial precursor protein of cytochrome c, in heat-treated cells, and the suppression of 14-3-3zeta expression by RNA interference resulted in the formation of significant amounts of aggregated apocytochrome c in the cytosol. The aggregated apocytochrome c was converted to a soluble form by the addition of 14-3-3zeta protein and ATP in vitro. 14-3-3zeta also resolubilized heat-aggregated citrate synthase and facilitated its reactivation in cooperation with Hsp70/Hsp40 in vitro. Our observations provide the first direct evidence that a 14-3-3 protein functions as a stress-induced molecular chaperone that dissolves and renaturalizes thermal-aggregated proteins.


インフルエンザウイルス感染の病態とプロテアーゼによる重症化機構

インフルエンザウイルス感染の病態とプロテアーゼによる重症化機構


Sendai virus infection up-regulates trypsin I and matrix metalloproteinase-9, triggering viral multiplication and matrix degrdation in rat lungs and lung L2 cells

To elucidate the virus-host cell interaction, we analyzed quantitatively the expression of various cellular proteases and tumor necrosis factor-alpha (TNF-alpha) after Sendai virus infection in rat lungs and lung L2 cells. After infection, TNF-alpha mRNA levels increased rapidly to a peak on day one, and then trypsin I and matrix metalloproteinase (MMP)-9, but not MMP-2, were significantly up-regulated with a peak on day 2 in vivo. These up-regulations were confirmed in L2 cells. Up-regulation of proMMP-9 and its active convertase trypsin I seems to synergistically enhance virus multiplication and the destruction of lung matrix, resulting in the progression of pneumonia.


Myeloid-related protein-8/14 is associated with proinflammatory cytokines in cervical mucus

Myeloid-related protein-8 (MRP-8), MRP-14, and MRP-8/14 are found in a variety of inflammatory conditions and are involved in the host defense system. The objective of this study was to determine the concentrations of MRP-8, MRP-14, and MRP-8/14 in human cervical mucus and the associations between MRP-8/14 and proinflammatory cytokines. Samples of cervical mucus were obtained using a syringe from sexually active women (n=97) during the preovulatory phase. Samples from seven women were obtained using a swab placed in the cervical canal during the proliferative, preovulatory, and luteal phases. Concentrations of MRP-8, MRP-14, MRP-8/14, IL-1alpha, IL-6, IL-8, and granulocyte elastase were measured using an ELISA. The mean levels of MRP-8, MRP-14, and MRP-8/14 in cervical mucus were 1.87, 0.46, and 23.90microg/ml, respectively. The concentration of MRP-8/14 showed positive correlations with concentrations of IL-1alpha (p<0.0001), IL-8 (p<0.0001), and granulocyte elastase (p<0.0001). However, there were no significant differences in MRP-8/14 levels in the cervical mucus of each patient during the menstrual cycle. MRP-8/14 was mainly detected in human cervical mucus and showed a positive correlation with proinflammatory cytokines. The MRP-8/14 level in cervical mucus may be useful as a marker of inflammation of the uterine cervix.


インフルエンザにおけるマクロライドの役割

インフルエンザにおけるマクロライドの役割


Identification of Trypsin I as a candidate for influenza A virus and Sendai virus envelope glycoprotein processing protease in rat brain,

Extracellular cleavage of virus envelope fusion glycoprotein hemagglutinin (HA0) by host trypsin-like proteases is a prerequisite for the infectivity and pathogenicity of human influenza A viruses and Sendai virus. The common epidemic influenza A viruses are pneumotropic, but occasionally cause encephalopathy or encephalitis, although the HA0 processing enzyme in the brain has not been identified. In searching for the brain processing proteases, we identified a processing enzyme in rat brain that was inducible by infection with these viruses. The purified enzyme exhibited an apparent molecular mass of approximately 22 kDa on SDS-PAGE and the N-terminal amino acid sequence was consistent with that of rat pancreatic trypsin I. Its substrate specificities and inhibition profiles were the same as those of pancreatic trypsin I. In situ hybridization and immunohistochemical studies on trypsin I distribution revealed heavy deposits in the brain capillaries, particularly in the allocortex, as well as in clustered neuronal cells of the hippocampus. The purified enzyme efficiently processed the HA0 of human influenza A virus and the fusion glycoprotein precursor of Sendai virus. Our results suggest that trypsin I in the brain potentiates virus multiplication in the pathogenesis and progression of influenza-associated encephalopathy or encephalitis.


小児インフルエンザ治療における抗ウイルス薬とマクロライド併用療法,

小児インフルエンザ治療における抗ウイルス薬とマクロライド併用療法,


インフルエンザ脳症の発症原因を探る-遺伝子多型と酵素機能解析から見たミトコンドリア脂肪酸代謝障害-


14-3-3 Protein levels and isoform patterns in the cerebrospinal fluid of Creutzfeldt-Jakob diseasepatients in the progressive and terminal stages

To elucidate the diagnostic value and to establish the 14-3-3 isoform patterns in the cerebrospinal fluid (CSF) of Creutzfeldt-Jakob disease (CJD) patients, we analysed the 14-3-3 isoform patterns in the CSF of 11 CJD patients using the Western immunoassay technique. 14-3-3 protein was detected in the CSF of seven CJD patients in the progressive stage, but not in four patients in the terminal stages whose brains were severely atrophied. The amount of 14-3-3 protein measured semi-quantitatively in the CSF was correlated with that of neuron-specific enolase measured using an enzyme-linked immunosorbent assay in the same CSF. CJD patients showed five dominant 14-3-3 isoforms, gamma, epsilon, zeta, eta and beta, but 14-3-3 tau, which mainly originates from T lymphocytes, was not detected. 14-3-3 protein is released into the CSF as a consequence of the extensive and rapid destruction of the brain, and the presence of the five isoforms enhances the diagnostic value of 14-3-3 protein in the progressive stage.


Modified pulmonary surfactant is a potent adjuvant that stimulates the mucosal IgA production in response to the influenza virus antigen

The intranasal administration of influenza hemagglutinin (HA) vaccine with Surfacten, a modified pulmonary surfactant free of antigenic c-type lectins, as a mucosal adjuvant induced the highest protective mucosal immunity in the airway. The intranasal immunization of mice with HA vaccine (0.2 microg)-Surfacten (0.2 microg) selectively induced the neutralizing anti-HA IgA, but not IgG, and conferred nearly maximal protection in the airway, without inducing a systemic response. In contrast, intranasal inoculation of vaccine with 0.2 microg of the potent mucosal adjuvant cholera toxin B* (CT-B*), prepared by adding 0.2% native CT to the B subunit of CT, induced both anti-HA IgA and IgG in the airway and in the serum. The intranasal administration of HA vaccine alone induced a limited amount of mucosal IgA against influenza virus. Although the s.c. administration of HA vaccine prominently induced serum IgG and IgA, Surfacten and CT-B* did not enhance their induction, and the concentrations of Abs leaking into the airways were insufficient to prevent viral multiplication. The intranasal administration of HA-Surfacten stimulated the expression of MHC class II, CD40, and CD86 molecules in the CD11c-positive cells isolated from the nasal mucosa, but not the expression of cells from the lungs or spleens. Lymphocytes isolated from the airway mucosa after intranasal HA-Surfacten immunization prominently induced TGF-beta1 which, compared with inoculation without Surfacten, promoted an Ag-specific mucosal IgA response. Surfacten alone, however, did not induce TGF-beta1. Our observations suggest that Surfacten, by mimicking the natural surfactant, is an effective mucosal adjuvant in the process of airway immunization.


インフルエンザウイルス感染とクラリスロマイシン

インフルエンザウイルス感染とクラリスロマイシン


肺の生体成分粘膜アジュバンドとインフルエンザ経鼻粘膜ワクチン

肺の生体成分粘膜アジュバンドとインフルエンザ経鼻粘膜ワクチン


ハイスループット食物アレルギー診断チップの開発-体質を映し出すテーラーメイド医療-


Chromatin-related proteins in pluripotent mouse embryonic stem cells are downregulated after removal of leukemia inhibitory factor

Embryonic stem (ES) cells have generated enormous interest due to their capacity to self-renew and the potential for growing many different cell types in vitro. Leukemia inhibitory factor (LIF), bone morphogenetic proteins, octamer-binding protein 3 or 4, and Nanog are important factors in the maintenance of pluripotency in mouse ES cells. However, the mechanisms by which these factors regulate the pluripotency remain poorly understood. To identify other proteins involved in this process, we did a proteomic analysis of mouse ES cells that were cultured in the presence or absence of LIF. More than 100 proteins were found to be involved specifically in either the differentiation process or the maintenance of undifferentiated state. Among these, chromatin-related proteins were identified as the major proteins in nuclear extracts of undifferentiated cells. Analysis with real-time RT-PCR revealed that enrichment of these proteins in pluripotent ES cells was regulated at the transcriptional levels. These results suggest that specific chromatin-related proteins may be involved in maintaining the unique properties of pluripotent ES cells.

Biochemical and Biophysical Research Communications


クラリスマイシンの粘膜免疫増張作用とインフルエンザウイルスの感染制御効果

クラリスマイシンの粘膜免疫増張作用とインフルエンザウイルスの感染制御効果


Chaperone Activities of the 26S and 20S Proteasome

The accumulation of misfolded or damaged proteins causes the failure of normal cell structure and functions necessary for growth and viability. To abort this adverse development, defective proteins must be rapidly repaired by molecular chaperones or destroyed by energy-dependent cytoplasmic proteases. A balance among these processes ultimately maintains cellular homeostasis. In eukaryotes, the 26S proteasome, a protease/chaperone complex, is a central component in the protein triage decision process. The 26S proteasome generally acts as a ubiquitination system, though it also selectively degrades structurally abnormal proteins in an ubiquitin-independent manner. In either case, all substrate proteins must undergo structural changes and stabilization necessary for their rapid degradation. It has, therefore, often been suggested that several chaperone functions are closely related to the stimulation of proteasomal degradation. This review summarizes recent discoveries pertaining to chaperone activities in the proteasomal degradation pathway, and to their regulation of protein breakdown mediated by the proteasome.


病気への罹りやすさと重症度を左右する体内酵素—インフルエンザの感染感受性とインフルエンザ脳症の発症感受性を決める酵素群—

第19回「大学と科学」公開シンポジウム講演収録集

第19回「大学と科学」公開シンポジウム講演収録集


Thermolabile phenotype of carnitine palmitoyltransferase II variations as a predisposing factor for influenza-associated encephalopathy

To assess the etiology of influenza-associated encephalopathy (IAE), a surveillance effort was conducted during 2000-2003 in South-West Japan. All fatal and handicapped patients except one (4/34 patients) exhibited a disorder of mitochondrial beta-oxidation evoked by the inactivated carnitine palmitoyltransferase II (CPT II) with transiently elevated serum acylcarnitine ratios (C(16:0) + C(18:1))/C(2) > 0.09 during high-grade fever. Analyses of genotypes and allele compositions of CPT II revealed a thermolabile phenotype of compound heterozygotes for [1055T > G/F352C] and [1102G > A/V368I], which shows a higher frequency in IAE patients than healthy volunteers (P < 0.025). The thermolabile phenotype of CPT II variations may be a principal genetic background of IAE in Japanese.


Purification and characterization of brarinasin, a new tissue kallikurein-like protease from the short-tailed shrew Blarina brevicauda-comparative stadies with blarina toxin

A new tissue kallikrein-like protease, blarinasin, has been purified from the salivary glands of the short-tailed shrew Blarina brevicauda. Blarinasin is a 32-kDa N-glycosylated protease with isoelectric values ranging between 5.3 and 5.7, and an optimum pH of 8.5 for enzyme activity. The cloned blarinasin cDNA coded for a pre-pro-sequence and a mature peptide of 252 amino acids with a catalytic triad typical for serine proteases and 43.7-54.0% identity to other mammalian tissue kallikreins. Blarinasin preferentially hydrolysed Pro-Phe-Arg-4-methylcoumaryl-7-amide (MCA) and N-tert-butyloxycarbonyl-Val-Leu-Lys-MCA, and preferentially converted human high-molecular-weight kininogen (HK) to bradykinin. The activity of blarinasin was prominently inhibited by aprotinin (K(i) =3.4 nM). A similar kallikrein-like protease, the lethal venom blarina toxin, has previously been purified from the salivary glands of the shrew Blarina and shows 67.9% identity to blarinasin. However, blarinasin was not toxic in mice. Blarinasin is a very abundant kallikrein-like protease and represents 70-75% of kallikrein-like enzymes in the salivary gland of B. brevicauda.


Accumulation of mini-plasmin in the cerebral capillaries causes vascular invasion of the murine brain by a pneumotropic influenza A virus: implications for influenza-associated encephalopathy

The infectivity and pathogenicity of influenza virus are primarily determined by host cellular trypsin-type processing proteases which cleave the viral membrane fusion glycoprotein hemagglutinin (HA). Therefore the distribution of the processing protease is a major determinant of the infectious organ tropism. The common epidemic human influenza A virus is pneumotropic and the HA processing proteases tryptase Clara, mini-plasmin, tryptase TC30 and ectopic anionic trypsin have all been isolated from mammalian airways. However, the pneumotropic influenza virus occasionally causes severe brain edema, particularly in children presenting with Reye's syndrome treated with aspirin, or in children with influenza-associated encephalopathy without antipyretic treatment. We have observed that, after influenza virus infection, the accumulation of mini-plasmin in the cerebral capillaries in mice with a congenital or acquired abnormality of mitochondrial beta-oxidation mimicking the pathological findings of Reye's syndrome, causes an invasion and multiplication of the pneumotropic influenza virus at these same locations. From these findings, we hypothesize that the accumulated mini-plasmin modifies the brain capillaries from a non-permissive to a permissive state, thereby allowing multiplication of pneumotropic influenza virus. In addition, mini-plasmin proteolytically destroys the blood-brain barrier. These pathologic findings, consistent with encephalopathy in mice with a systemic impairment of beta-oxidation, may have implications for human influenza encephalopathy.


Mitochondrial targeting sequence of the influenza A virus PB1-F2 protein and its function in mitochondria

The influenza A virus PB1-F2 protein predominantly localizes in the mitochondria of virus-infected cells. A series of cDNAs encoding N- and C-terminal deletion mutants and site-directed mutagenesis of the basic residues of PB1-F2 appended to 3xFLAG revealed the domain from residues 46 to 75 to be both necessary and sufficient for mitochondrial targeting. In addition, the subdomain residues 63-75 and both Lys73 and Arg75 are minimally required for mitochondrial localization. Transfection of untagged- and 3xFLAG tagged-PB1-F2 into Vero, HeLa and MDCK cells changed the mitochondrial morphology from a filamentous to a dotted structure and suppressed the inner-membrane potential.


Secretory leukoprotease inhibitor and pulmonary surfactant serve as principal defenses against influenza A virus infection in the airway and chemical agents up-regulating their levels may have therapeutic potential

Influenza A virus (IAV) is one of the most common infectious pathogens in humans. Entry of this virus into cells is primarily determined by host cellular trypsin-type processing proteases, which proteolytically activate viral membrane fusion glycoprotein precursors. Human IAV and murine parainfluenza virus type 1 Sendai virus are exclusively pneumotropic, and the infectious organ tropism of these viruses is determined by the susceptibility of the viral envelope glycoprotein to cleavage by proteases in the airway. Proteases in the upper respiratory tract are suppressed by secretory leukoprotease inhibitor, and those in the lower respiratory tract are suppressed by pulmonary surfactant, which by adsorption inhibits the interaction between the proteases and viral membrane proteins. Although the protease activities are predominant over the activities of inhibitory compounds under normal airway conditions, intranasal administration of inhibitors was able to significantly suppress multi-cycles of viral replication in the airway. In addition, we identified chemical agents that could act as defensive factors by up-regulating the levels of the natural inhibitors and immunoglobulin A (IgA) in airway fluids. One of these compounds, ambroxol, is a mucolytic and anti-oxidant agent that stimulates the release of secretory leukoprotease inhibitor and pulmonary surfactant in the early phase, and IgA in the late phase of infection at an optimal dose, i.e. a dose sufficient to inhibit virus proliferation and increase the survival rate of animals after treatment with a lethal dose of IAV. Another agent, clarithromycin, is a macrolide antibiotic that increases IgA levels through augmentation of interleukin-12 levels and mucosal immunization in the airway. In addition to the sialidase inhibitors, which prevent the release of IAV from infected cells, inhibitors of the processing proteases and chemical agents that augment mucosal immunity and/or levels of the relevant defensive compounds may also ultimately prove to be useful as new anti-influenza agents.


Blarina toxin, a mammalian lethal venom from the short-tailed shrew Blarina brevicauda: Isolation and characterization

Venomous mammals are rare, and their venoms have not been characterized. We have purified and characterized the blarina toxin (BLTX), a lethal mammalian venom with a tissue kallikrein-like activity from the submaxillary and sublingual glands of the short-tailed shrew Blarina brevicauda. Mice administered BLTX i.p. developed irregular respiration, paralysis, and convulsions before dying. Based on the amino acid sequence of purified protein, we cloned the BLTX cDNA. It consists of a prosequence and an active form of 253 aa with a typical catalytic triad of serine proteases, with a high identity with tissue kallikreins. BLTX is an N-linked microheterogeneous glycoprotein with a unique insertion of 10 residues, L(106)TFFYKTFLG(115). BLTX converted kininogens to kinins, which may be one of the toxic pathogens, and had dilatory effects on the blood vessel walls. The acute toxicity and proteolytic activity of BLTX were strongly inhibited by aprotinin, a kallikrein inhibitor, suggesting that its toxicity is due to a kallikrein-like activity of the venom.

Proceedings of the National Academy of Sciences of the United States of America


クラリスロマイシンに気道の粘膜免疫増強作用

クラリスロマイシンに気道の粘膜免疫増強作用


20S Proteasome prevents aggregation of heat-denatured proteins without PA700 regulatory subcomplex like a molecular chaperone


インフルエンザウイルスの感染感受性と感染臓器特異性を決める個体のプロテアーゼ群

インフルエンザウイルスの感染感受性と感染臓器特異性を決める個体のプロテアーゼ群

Japanese Journal of Thrombosis and Hemostasis


Inhibitory effect of FK506 and Cyclosporine A on the growth and invation of human liver cancer cells

The prognosis of liver transplantation for liver cancer is determined by recurrence in the liver graft. In this study, the effects of immunosuppressors, FK506 and cyclosporine A (CsA) on the migration of liver cancer cells were investigated. The effects of FK506 at concentrations of 1-100 ng/mL and CsA at 1-1000 ng/mL on the growth of poorly and well differentiated human hepatocellular carcinoma cell lines, HLE and HuH-7, respectively, were examined. After treatment of these cells with FK506 and CsA, the growth of these cells, their cytotoxicities and invasion assay on the Matrigel basement membrane invasion chamber were evaluated. In addition, the effects of FK506 and CsA on the changes in the production of a soluble intercellular adhesion molecule-1 (sICAM-1) of these cells were measured. FK506 and CsA at concentrations of 1-10 ng/mL inhibited the growth of both HLE and HuH-7 and those immunosuppressors at concentrations over 100 ng/mL exhibited cytotoxicity on these cells. FK506 at concentration of 1 ng/mL significantly inhibited the invasion of poorly differentiated HLE, but not well differentiated HuH-7, after treatment for 2-5 days in culture (p<0.05), but FK 506 at 10 ng/mL showed less inhibitory efficient. CsA at concentrations of 1-10 ng/mL, however, did not inhibit or transiently inhibited the invasion of both cell lines. The production of ICAM-1 in HLE and HuH-7 was suppressed by FK506 at concentrations of 1-10 ng/mL after treatment for 3-5 days but the effect was not significant in the initial phase at days 1-2 and the last phase at days 5-6. FK506, but not CsA, at a clinical dose of 1 ng/mL significantly inhibited the invasion of the poorly-differentiated HLE, but not HuH-7 and also inhibited the production of sICAM-1 in HLE.

The Journal of Medical Investigation : JMI


ダイヤモンドコーティング高密度集積技術のプロテオミクス解析への応用

ダイヤモンドコーティング高密度集積技術のプロテオミクス解析への応用


インフルエンザ脳症の発症機序

インフルエンザ脳症の発症機序


The second metal-binding site of 70kDa heat-shock protein is essential for ADP-binding, ATP hydrolysis and ATP synthesis

The chaperone activity of Hsp70 (70 kDa heat-shock protein) in protein folding and its conformational switch, including oligomeric and monomeric interconversion, are regulated by the hydrolysis of ATP and the ATP-ADP exchange cycle. The crystal structure of human ATPase domain shows two metal-binding sites, the first for ATP binding and a second, in close proximity to the first, whose function remains unknown [Sriram, Osipiuk, Freeman, Morimoto and Joachimiak (1997) Structure 5, 403-414]. In this study, we have characterized the second metal-binding motif by site-directed mutagenesis and the kinetics of ATP and ADP binding, and found that the second metal-binding site, comprising a loop co-ordinated by His-227, Glu-231 and Asp-232, participates both in ATP hydrolysis and ATP-synthetic activities, in co-operation with the first metal-binding site. The first metal-binding site, a catalytic centre, is essential for ATP binding and the second site for ADP binding in the reactions of ATP hydrolysis and ATP synthesis.


Endothelin-1 peptides and IL-5 synergistically increase the expression of IL-13 in eosinophils.

The 21-amino acid-length endothelin-1 (ET-1)(1-21) and its novel derivative, 31 amino acid-length ET-1(1-31), have proinflammatory properties and induce significant eosinophil migration mediated by an increase in the local levels of eotaxin and IL-5. We have analyzed by reverse transcription polymerase chain reaction and enzyme immunoassay the effects of ETs on the expression of IL-13 mRNA and protein in eosinophils with or without cell priming with IL-5. The expression of the ETA receptor (ETAR) and its membrane localization were detected in the eosinophils, whereas the ETB receptor was undetectable. ET peptides synergistically increased the expression of IL-13 in eosinophils after priming with IL-5, and the increase was blocked by the ETAR antagonist BQ123, though these peptides did not directly influence the expression. These results may explain the presence of eosinophilia in the airways' epithelium of patients suffering from asthma, along with an increase in immunoreactive ETs.

Biochemical and Biophysical Research Communications


Amiloride and Urinary Trypsin Inhibitor Inhibit Urothelial Cancer Invasion

To determine the contribution of urokinase-type plasminogen activator (uPA) and plasmin in the invasion of highly invasive urothelial cancer cells. We compared expression levels of mRNA and protease activity of uPA and plasmin formation in primary cultures of the noninvasive transitional cell carcinoma, UCT-1, and in the highly invasive type, UCT-2. By using in vitro cell invasion assay system, we evaluated the effects of amiloride and urinary trypsin inhibitor (UTI), which inhibit uPA and plasmin, respectively, on invasion by both cell lines. Expression levels of mRNA, protein, and activities of uPA were significantly higher (p<0.005) and resulted in more plasminogen activation in UCT-2 than in UCT-1. Amiloride and UTI significantly inhibited plasmin formation and the invasion of both cell lines (p<0.001). High expression levels of mRNA, activities of uPA and high plasmin formation significantly potentiated the invasiveness of urothelial cancer cells. Thus, inhibitors of uPA and plasmin, such as amiloride and UTI, respectively, could be useful therapeutic tools with which to treat urothelial cancer.


The effect of topically applied secretory leukocyte protease inhibitor on the eosinophil response in the late phase of allergic conjunctivitis

This study examined the effects of secretory leukocyte protease inhibitor (SLPI), a protease inhibitor in tears, in allergic conjunctivitis. Conjunctiva of male Hartley guinea pigs sensitized with ovalbumin were treated with SLPI or the vehicle 10 min before antigen challenge or simultaneously. The animals were sacrificed after antigen challenges of 0-24 h duration, and the inhibition of eosinophil conjunctival migration and degranulation by SLPI was analyzed histochemically. The effects of SLPI on mast cell chymase and tryptase were also examined. Treatment of sensitized guinea pigs with SLPI suppressed the conjunctival recruitment and degranulation of eosinophils after antigen challenge for 6 h, inhibiting the development of allergic conjunctivitis. The effects of SLPI were observed at concentrations > or =0.1 microM, with a peak at 5 microM. SLPI inhibited chymase in a dose-dependent manner, but had no effect on tryptase. The topical SLPI application may be therapeutic in allergic conjunctivitis.


Cloning and characterization of a novel transmembrane-type serine Protease from rat kidney, a new member among the sodium channel activators

We have cloned the gene of a new transmembrane-type serine protease from rat kidney, which activates sodium channels. The amino acid sequence deduced from a full-length cDNA revealed that transmembrane serine protease-1 (TMSP-1) is a member of the clan SA/family S1 of serine proteases, comprising a 30 amino acid prepropeptide, a mature form sequence of 274 amino acids starting with the Ile-Val-Gly-Gly-Gln motif, and a common catalytic triad of serine proteases. The hydrophobic amino acid sequence in the carboxy-terminus of this enzyme suggests that it is a glycosylphosphatidylinositol-anchored protein. As revealed by quantitative reverse transcription-polymerase chain reaction analysis, it is highly expressed in kidney, small intestine, and stomach, and moderately expressed in lung, thymus, spleen and skin. The recombinant protease had an optimal pH at 9.0, selectively cleaved synthetic peptide substrates of trypsin, and was inhibited by aprotinin, leupeptin and benzamidine. Immunohistochemical studies revealed that this protease is predominantly expressed in cells from collecting ducts of the renal medulla. We also demonstrate that a C-terminally truncated variant of TMSP-1 significantly activates the epithelial sodium channel, and that its mRNA levels are upregulated by aldosterone. These observations suggest that it is a new member of the trypsin-type transmembrane proteases, which regulate sodium balance by activating the epithelial sodium channel.


Inhibition of the protease activity of influenza virus RNA polymerase PA subunit by viral matrix protein

Influenza virus PA is a subunit of RNA-dependent RNA polymerase. We demonstrated that PA has a unique chymotrypsin-like serine protease activity with Ser624 as an active site. To obtain further insight into the role of the protease activity of PA in viral proliferation, we examined the interaction between PA and matrix protein (M1). Both M1 purified from virion and hexa-histidine-tagged M1 expressed in Escherichia coli bound to PA. Hexa-histidine-tagged M1 pulled down PA. The interaction of PA with M1 was sensitive to ionic strength, suggesting that the interaction is formed by electrostatic force. Using Suc-Leu-Leu-Val-Tyr-MCA, a specific substrate for PA protease, M1 was demonstrated to inhibit the amidolytic activity of PA, whereas M1 did not inhibit that of chymotrypsin or trypsin at all. These results suggest that M1 binds to and inhibits the amidolytic activity of PA.


Human mast cell chymase and 31 amino acid endothelin-1. New inflammatory mediators in cardiovascular diseases

Cardiomyopathies and Heart Failure: Biomolecular, Infectious and Immune Mechanisms


Binding of a new bioactive 31-amino-acid endothelin-1 to an endothelin ETB or ETB-like receptor in porcine lungs.

Endothelin-1-(1-31) is a new bioactive 31-amino-acid-length peptide generated from big endothelin-1 by chymase or other chymotrypsin-type proteases with various pathophysiologic functions. In this study, we have detected the specific and monophasic binding of [125I]endothelin-1-(1-31) in porcine lung membranes. Competition studies of [125I]endothelin-1-(1-31) binding by unlabeled endothelin-1-(1-31), endothelin-1, endothelin-3, and antagonists and agonists of endothelin ET(A) and ET(B) receptors suggest that the binding protein is an endothelin ET(B) or ET(B)-like receptor rather than an endothelin ET(A) receptor in porcine lungs. Kinetic studies showed that the affinity of endothelin-1-(1-31) to its receptor was approximately one order of magnitude lower than that of endothelin-1, and that the specific binding of endothelin-1-(1-31) was about 19% of endothelin-1 binding. The binding of [125I]endothelin-1-(1-31) was extremely slow, slower even than that of endothelin-1, and nearly irreversible. This unique quasi-irreversibility may explain the slow-onset and long-lasting biologic effects of this peptide in vivo.


抗インフルエンザ作用を示す去痰剤の不思議,新たな薬理作用の機序

抗インフルエンザ作用を示す去痰剤の不思議,新たな薬理作用の機序


Cloning, expression analysis, and tissue distribution of esp-1/testisin, a membrane-type serine protease from the rat.

The Journal of Medical Investigation : JMI


インフルエンザウイルスの感染感受性をきめる個体のプロテアーゼ群とインフルエンザ脳症の発症機序

The pathogenesis of the influenza and Sendai viruses is primarily determined by host cellular trypsin-type processing proteases that activate viral fusion activity and infectivity. We isolated three secretory trypsin-type proteases from rat lungs, such as tryptase Clara, mini-plasmin, and ectopic anionic trypsin, candidates for the processing proteases of viral envelope glycoproteins. These enzymes specifically cleave the precursor of fusion glycoprotein hemagglutinin (HA) of influenza virus at Arg325 and the F0 of Sendai virus at Arg116 in the consensus cleavage motif, Gln(Glu)-X-Arg, resulting in the induction of infectivity of these viruses. These proteases show different localization in the airway and susceptibility for the processing of various subtypes of influenza virus HA, suggesting that these processing proteases determine the viral pathogenicity. Influenza virus readily infects and replicates in the airway epithelial cells but occasionally replicates in the central nervous system, particularly in children below 5-6 years of age and Reye's syndrome patients. We found an invasion by a non-neurovirulent influenza virus in cerebral capillaries with progressive brain edema of mice having impaired mitochondrial fatty acid metabolism congenitally or posteriorly in the newborn period. In the brain of these mice, mini-plasmin, which potentiates viral-multiplication in vivo and destroys the blood-brain barrier, accumulated with virus antigen in the brain capillaries but only a little in the control mice without impaired mitochondrial fatty acid metabolism.

インフルエンザウイルスの生体内増殖に個体由来のトリプシン型プロテアーゼが必須で，ウイルスの感染性発現の決定因子になっている．最近このプロテアーゼ群の解明が進み，気道の分泌型プロテアーゼのトリプターゼクララ，ミニプラスミン，異所性肺トリプシン，膜結合型トリプシン型プロテアーゼ群が相次いで同定された．これらのプロテアーゼはそれぞれ局在を異にするだけでなく，ウイルス亜系によってプロテアーゼとの親和性を異にして，ウイルスの増殖部位と臨床症状を決めている．一方これらのプロテアーゼ群に対する生体由来の阻害物質の粘液プロテアーゼインヒビターや肺サーファクタントが明らかとなり，合わせて個体のウイルス感染感受性を決める重要な因子となっている．小児のインフルエンザ感染では，aspirin，diclophenac sodium服用時のライ症候群や，解熱剤を服用していない患者でも見られる急速な脳浮腫を主症状とする致死性の高いインフルエンザ脳症が社会問題になっている．インフルエンザ脳症発症モデル動物を用いた我々の研究から，このインフルエンザ脳症の原因として，インフルエンザ感染と共に脳血管内皮細胞で急速に増加するミニプラスミンが，血液脳関門の障害と血管内皮細胞でのウイルス増殖に，直接関与していることが明らかとなってきた．さらにミニプラスミンの血管内皮での蓄積を裏付けるミニプラスミンやプラスミンのレセプターが，発症感受性の高い動物の血管内皮で見いだされた．これらのことからインフルエンザ脳症は，発症感受性遺伝子，発症感受性因子の検索に研究の焦点が絞られてきた．本総説では，我々の研究を中心に最近の知見を紹介する．


Pathologic mechanisms of influenza encephalitis with an abnormal expression of inflammatory cytokines and accumulation of mini-plasmin

The pathogenesis of influenza encephalopathy or encephalitis is poorly understood. This review summarizes our recent studies of the roles played by inflammatory cytokines, inducible nitric oxide synthase (iNOS), adhesion molecules and mini-plasmin in influenza encephalitis. After the intranasal infection of newborn mice with the non-neurotropic strain of influenza A virus (IAV) Aichi/2/68/H3N2, encephalitis and severe brain edema were observed within 3-5 days. IAV-RNA and abnormalities in the blood-brain barrier permeability were detected in association with an increase in the mRNA expressions of endothelin-1, iNOS, and tumor necrosis factor-alpha. Furthermore, the accumulation in the brain capillaries of mini-plasmin, which proteolytically induces the viral envelope fusion activity and allows the virus to enter the cells, changes the brain from non-susceptible to susceptible to non-neurotropic IAV multiplication. The accumulation of mini-plasmin was markedly greater in newborn mice with an impaired mitochondrial fatty acid metabolism. These inflammatory mediators and the accumulation of mini-plasmin in the brain may play an important role in the onset and progression of LAV encephalitis.


肺サーファクタントはインフルエンザ感染に対する重要な生体防御物質の1つである.肺サーファクタントの作用とその分泌促進剤

Journal of Japanese Medical Society for Biological Interface


A novel influenza A virus activating enzyme from porcine lung: Purification and characterization

Proteolytic activation of hemagglutinin, an envelope glycoprotein of the influenza virus, by host proteases is essential for infection and proliferation of the virus. However, there is no well-defined, inherent source of host proteases in man or swine, both of which are natural hosts for human influenza viruses. We have recently isolated a 32 kDa protein in a high salt extract from porcine lungs, which possess the hemagglutinin processing activity. In this study, we attempted to purify another hemagglutinin processing enzyme from porcine lung. The purified enzyme, named tryptase TC30, exhibited a molecular mass of about 30 kDa by SDS-PAGE and 28.5 kDa by gel filtration chromatography, suggesting that it is a monomer. Tryptase TC30 cleaved peptide substrates with Arg at the P1 position, and preferentially substrates with the Ser-Ile-Gin-Ser-Arg sequence corresponding to the HA cleavage site sequence of the A/PR/8/34 influenza virus. Among various inhibitors tested, trypsin-type serine protease inhibitors, such as aprotinin, antipain, benzamidine and leupeptin, efficiently inhibited the proteolytic activity of the enzyme. The N-terminal 40 amino acid sequence of tryptase TC30 exhibits more than 60% homology to mast cell tryptases from mice MCP-6 and human tryptase-alpha and -beta. These data indicate that tryptase TC30, the 30 kDa enzyme from porcine lung, is a novel hemagglutinin-cleaving enzyme.


インフルエンザウイルスの特性:増殖と感染のメカニズムー最新の知見をもとにー

インフルエンザウイルスの特性:増殖と感染のメカニズムー最新の知見をもとにー


生体のウイルス感染感受性因子と近未来型感染予防法

生体のウイルス感染感受性因子と近未来型感染予防法


Chondroitin sulfate proteoglycan Is a potent enhancer in the processing of procathepsin L

The acceleration effect of chondroitin-4-sulfate(CS-) proteoglycan on the processing of procathepsin L in vitro was investigated using enzyme purified from the culture medium of MLC cells. Procathepsin L was slightly processed even when it was incubated without CS-proteoglycan for 60 min in 50 mm acetate buffer, pH 5.5, and trace amounts of the 31 kDa mature form and 35-38 kDa intermediates of cathepsin L were formed. On the other hand, in the presence of CS-proteoglycan, procathepsin L was completely converted to the mature form within the same 60 minute time period. Moreover, Z-Phe-Arg-MCA hydrolyzing activity was increased significantly by the incubation with CS-proteoglycan, while no considerable increase in the activity was observed during the incubation without CS-proteoglycan. Since the specific cathepsin L inhibitor, CLIK-195, inhibited the processing of procathepsin L accelerated by CS-proteoglycan, the trace amount of cathepsin L activity may participate in the processing. These results suggest that CS-proteoglycan may play a role in accelerating the processing of procathepsin L as an endogenous enhancer in the extracellular environment in vivo.


ダイヤモンドDNAチップ「ジーンダイヤ 」の応用とチップを用いたプロテオミクス解析

The Journal of the Institute of Electronics, Information and Communication Engineers


Identification of ectopic anionic trypsin I in rat lungs potentiating pneumotropic virus infectivity and increased enzyme level after virus infection

Extracellular cleavage of virus envelope fusion glycoproteins by host cellular proteases is a prerequisite for the infectivity of mammalian and nonpathogenic avian influenza viruses, and Sendai virus. In search of such target processing proteases in the airway, we recently found a new candidate trypsin-like processing protease in rat lungs, which was induced by Sendai virus infection, and identified as ectopic rat anionic trypsin I. On SDS/PAGE under reducing and nonreducing conditions, the purified enzyme gave protein bands corresponding to 29 and 22 kDa, respectively, i.e. at the same positions as rat pancreatic anionic trypsin I. It exhibited an apparent molecular mass of 31 kDa on molecular sieve chromatography and its isoelectric point was pH 4.7. The amino-acid sequences of the N-terminus and proteolytic digest peptides of the purified enzyme were consistent with those of rat pancreatic anionic trypsin I. Its substrate specificities and inhibitor sensitivities were the same as those of the pancreatic enzyme. The purified enzyme efficiently processed the fusion glycoprotein precursor of Sendai virus and hemagglutinin of human influenza A virus, and potentiated the infectivity of Sendai virus in the same dose-dependent manner as the pancreatic one. Immunohistochemical studies revealed that this protease is located in the stromal cells in peri-bronchiolar regions. These results suggest that ectopic anionic trypsin I in rat lungs induced by virus infection may trigger virus spread in rat lungs.


生体防御因子群の分泌を促進する塩酸アンブロキソールの抗インフルエンザ効果,

生体防御因子群の分泌を促進する塩酸アンブロキソールの抗インフルエンザ効果,


A novel bioactive 31-amino acid endothelin-1 peptide stimulates eosinophil recruitment, and increases the level of eotaxin and IL-5

Investigation of the role of a novel inflammatory mediator 31-amino acid endothelin-1 [ET-1 (1-31)], a major ET derivative in granulocytes, in eosinophil recruitment after its subcutaneous administration to mice. Various ET-1 derivatives (100 pmol), with or without ET receptor antagonists (200 pmol), were administered subcutaneously to mice, and then the eosinophil migration into and chemokine levels in the injected loci were analyzed. ET-1 (1-31) and a 21-amino acid endothelin-1 (ET-1), but not big ET-1, induced eosinophil migration into the injected loci with a peak after administration for 12 h, and increased the levels of eotaxin and interleukin-5 with peaks at 6 and 24 h, respectively. These effects of ET-1(1-31) and ET-1 were significantly inhibited by an ETA receptor antagonist, BQ-123, but not by an ETB receptor antagonist, BQ-788. Novel bioactive ET-1 (1-31) induces local eosinophil migration, and increases in eotaxin and interleukin-5 through an ETA or ETA-like receptor.


生体防御物質の気道内分泌を促進する塩酸アンブロキソールの抗インフルエンザ効果

生体防御物質の気道内分泌を促進する塩酸アンブロキソールの抗インフルエンザ効果


インフルエンザウイルスの感染性と感染憎悪を制御する生体内プロテアーゼとインヒビター


Ambroxol suppresses influenza-virus proliferation in the mouse airway by incresing antiviral factor levels

The protective effect of ambroxol, a mucolytic agent which has antioxidant properties and stimulates the release of pulmonary surfactant, against influenza-virus proliferation in the airway was investigated in mice. Ambroxol or the vehicle was administered intraperitoneally twice a day for 5-7 days to mice shortly after intranasal infection with a lethal dose of influenza A/Aichi/68 (H3N2) virus, and the survival rate, virus titre and levels of factors regulating virus proliferation in the airway fluid were analysed. Ambroxol significantly suppressed virus multiplication and improved the survival rate of mice. The effect of ambroxol reached a peak at 10 mg x kg(-1) x day(-1), higher doses being less effective. Ambroxol stimulated the release of suppressors of influenza-virus multiplication, such as pulmonary surfactant, mucus protease inhibitor, immunoglobulin (Ig)-A and IgG, although it stimulated the release of a trypsin-type protease that potentiates virus proliferation. In addition, ambroxol transiently suppressed release of the cytokines, tumour necrosis factor-alpha, interferon-gamma and interleukin-12, into airway fluid. Although ambroxol had several negative effects on the host defence system, overall it strikingly increased the concentrations of suppressors of influenza-virus multiplication in the airway.


Involvement of carbohydrate molecules on zona pellucida in human fertilization

Although the involvement of several receptors and ligand molecules in sperm-zona interaction in many species have been proposed, there has been a little analysis of the kinetics between these molecules during the interaction. In the present study, we applied the detection method using surface plasmon resonance (SPR) by a BIAcore apparatus for the analysis of the putative receptor-ligand interaction of sperm-egg binding. Mannose-BSA or [man](5)-[GlcNAc](2)-Asp was immobilized on the surface of a sensor chip. When concanavalin A (Con A) was delivered to each of two different sensor chips to evaluate their usefulness, the resonance signal after sample injection onto a [man](5)-[GlcNAc](2)-Asp-fixed chip decreased rapidly than the mannose-BSA-fixed chip. However, the amount of binding for Con A during the injection onto the [man](5)-[GlcNAc](2)-Asp-fixed chip was high. When acid sperm extracts (acid extracts) and fractions through a CM column, containing protease activity (protease fractions), were delivered to the mannose-BSA-fixed chip, the SPR signal during the injection was not obviously changed compared with that of the control. However, when sperm samples were delivered to the [man](5)-[GlcNAc](2)-Asp-fixed chip, the SPR response during the injection was enormous. These results suggest that the [man](5)-[GlcNAc](2)-Asp-fixed chip is more useful than the mannose-BSA-fixed chip for investigating the interactions with sperm extracts and that the sensitive method using SPR by a BIAcore apparatus is applicable for the analysis of the putative receptor-ligand interaction of sperm-egg binding.


Role of Mast Cell Tryptase in Renal Interstitial Fibrosis

Renal interstitial fibrosis is characterized by increased proliferation of fibroblasts and excessive accumulation of extracellular matrix. Mast cell tryptase has been implicated in the development of tissue fibrosis in skin and lungs. However, the significance of mast cell tryptase in human renal diseases has not been investigated. The potential role of mast cell-derived tryptase in the development of renal fibrosis was studied using immunohistochemical techniques and cultured human renal fibroblast cell lines. Semiquantitative immunostaining analysis of samples from 70 patients with several renal diseases, including IgA glomerulonephritis (GN) (n = 30), non-IgA GN (n = 5), membranous GN (n = 5), focal segmental glomerulosclerosis (n = 4), minor glomerular abnormalities (n = 5), lupus nephritis (n = 3), and acute or chronic tubulointerstitial nephritis (n = 18), revealed that the degree of renal interstitial fibrosis was well correlated with the number of infiltrating tryptase-positive mast cells (P < 0.01). Mast cells could not be detected in damaged glomeruli in any form of renal disease. [(3)H]Thymidine uptake experiments demonstrated that DNA synthesis by cultured renal fibroblasts was increased with the concentration of tryptase (0.5 to 5 nM) coincubated with heparin and was suppressed by coincubation with the protease inhibitors leupeptin and benzamidine hydrochloride. Tryptase alone also increased DNA synthesis by fibroblasts but exhibited less effectiveness, compared with the combination of tryptase and heparin. Conversely, heparin alone suppressed DNA synthesis by fibroblasts. Metabolic [(35)S]methionine-labeling experiments with cultured renal fibroblasts indicated that tryptase increased the synthesis of fibronectin and collagen type I, in a dose-dependent manner. These findings suggest that mast cell tryptase plays a role in the proliferation and extracellular matrix protein production of renal interstitial fibroblasts and thus contributes to the development of renal interstitial fibrosis.

Journal of the American Society of Nephrology


A novel bioactive 31-amino acid endothelin-1 is a potent chemotactic peptide for human neutrophils and monocytes

Endothelin (ET)-1(1-31) is a novel 31-amino acid-length peptide derived from big ET-1 by chymase or other chymotrypsin-type proteases and is a major ET derivative in human neutrophils. In this study, we revealed that ET-1(1-31), but not big ET, exhibited chemotactic activities toward human neutrophils and monocytes as an inflammatory mediator, although the effects were less potent than those of formyl-methionyl-leucyl-phenylalanine or interleukin-8. However, the chemotactic effects of ET-1(1-31) were much greater than those of the 21-amino acid ET-1, ET-1(1-21). Checkerboard analyses revealed that the effects are chemotactic rather than chemokinetic. The effects of ET-1(1-31) are not mediated by interleukin-8 or monocyte chemoattractant protein-1. The chemotactic effects and an increase in intracellular-free Ca(2)(+) caused by ET-1(1-31) were significantly inhibited by BQ123, an ET(A) receptor antagonist, but not by BQ788, an ET(B) receptor antagonist, suggesting that ET-1(1-31) mediates chemotaxis through an ET(A) or ET(A)-like receptor.


Protease activity of influenza virus RNA polymerase PA subunit


Increased concentrations of 14-3-3ϵ,γ and ζ isoforms in cerebrospinal fluid ofAIDS patients with neuronal destruction

14-3-3 proteins are major evolutionarily conserved cytosolic proteins that regulate signal transduction, apoptosis and neurotransmitter synthesis. Five homologous 14-3-3 isoforms, beta, gamma, zeta, epsilon and eta, are reported in mammalian neurones. To elucidate the diagnostic value of 14-3-3 in cerebrospinal fluid (CSF), a highly specific antibody against each isoform and studies on the isoform patterns in patients with neuronal destruction are needed. In this study, we raised isoform-specific antibodies against 14-3-3 proteins and established a semiquantitative method of identification of each isoform by Western immunoblotting. We found that three isoforms, 14-3-3 epsilon, gamma and zeta, appeared in the CSF of HIV patients with AIDS dementia complex or cytomegalovirus encephalitis, but not in AIDS patients without neurological symptoms or the non-HIV patients examined. The isoform patterns in AIDS patients were different from those reported in Creutzfeldt-Jakob disease and herpes simplex encephalitis, suggesting that the isoform patterns may facilitate the differential diagnosis. A high frequency of 14-3-3 in CSF was observed in seriously ill AIDS patients, particularly those with CD4 levels of less than 20 mm(3). These findings suggested that 14-3-3 proteins were released from destroyed neural cells and are useful real-time markers of the rate and amount of neural cell destruction in these patients.


生体防御物質の気道分泌を促進する去痰剤の抗インフルエンザ効果と今後の展望,特集 喘息長期管理"吸入ステロイド軸に成人·小児とも新ステージへ"


プロテアーゼとプロテアーゼインヒビターが決定する,インフルエンザウイルスの感染と防御

第15回大学と科学公開シンポジウム組織委員会編"タンパク質分解の不思議"

第15回大学と科学公開シンポジウム組織委員会編"タンパク質分解の不思議"


Mini-plasmin found in the epithelial cells of bronchioles triggers infection by broad-spectrum influenza A viruses and Sendai virus

Extracellular cleavage of virus envelope fusion glycoproteins by host cellular proteases is a prerequisite for the infectivity of mammalian and nonpathogenic avian influenza viruses, and Sendai virus. Here we report a protease present in the airway that, like tryptase Clara, can process influenza A virus haemagglutinin and Sendai virus envelope fusion glycoprotein. This protease was extracted from the membrane fraction of rat lungs, purified and then identified as a mini-plasmin. Mini-plasmin was distributed predominantly in the epithelial cells of the upward divisions of bronchioles and potentiated the replication of broad-spectrum influenza A viruses and Sendai virus, even that of the plasmin-insensitive influenza A virus strain. In comparison with plasmin, its increased hydrophobicity, leading to its higher local concentrations on membranes, and decreased molecular mass may enable mini-plasmin to gain ready access to the cleavage sites of various haemagglutinins and fusion glycoproteins after expression of these viral proteins on the cell surface. These findings suggest that mini-plasmin in the airway may play a pivotal role in the spread of viruses and their pathogenicity.


シャペロン,プロテアソーム "基礎生化学実験法"タンパク質II 機能

シャペロン,プロテアソーム "基礎生化学実験法"タンパク質II 機能


Cloning and Expression of Novel Mosaic Serine Proteases with and without a Transmembrane Domain from Human Lung

Two cDNAs encoding novel mosaic proteins with a serine protease domain and potential regulatory modules, consisting of a protein kinase substrate and a low-density lipoprotein receptor, were cloned from a human lung cDNA library by PCR. One with a transmembrane domain (MSPL) and the other without one (MSPS) comprise 581 and 537 amino acids, respectively. Except for the C-terminal ends, the two isoforms had an identical serine protease domain exhibiting 42, 39 and 43% identity with those of plasma kallikrein, hepsin and transmembrane protease serine 2, respectively. Both genes were predominantly expressed in human lung, placenta, pancreas and prostate.

Biochimica et Biophysica Acta (BBA) - Gene Structure and Expression


プロテアソームの中の分子シャペロン

プロテアソームの中の分子シャペロン


Determination of the Levels of Novel Bioactive 31-Amino-Acid Endothelins and Endothelins in Human Lungs

An effective method for determination of the levels of newly discovered 31-amino acid endothelins [ETs(1-31)] as well as big ETs and 21-amino acid ETs [ETs(1-21)], in human lungs has been developed. About 85% of ETs in human lung homogenates were recovered on acid extraction 8 times. Most of the published protocols for the determination of tissue ETs involve a reverse-phase minicolumn to separate proteins from peptides, after which the levels of ETs are directly determined by enzyme immunoassay. The levels determined, however, include fairly high amounts of non-bioactive ET metabolites in tissues and the data reported are diverse. We established an effective methods for the extraction and the separation of nine different muscle constricting ETs from their metabolites on a reverse-phase C18 column. Using this protocol, the levels of ETs in human lungs were determined by means of a sandwich-enzyme immunoassay specific for each ET derivative. The levels of ET-2(1-21) were the highest among those of ETs, and the levels of ETs(1-31) were in a similar range to those of big ETs but were lower than those of ETs(1-21). This method can be utilized to assess the pathophysiological roles of ETs(1-31) in various human organs.


Influenza Virus RNA Polymerase PA Subunit is a Novel Serine Protease with Ser 624 in the Active Site

Influenza virus RNA polymerase is a multifunctional enzyme that catalyses both transcription and replication of the RNA genome. The function of the influenza virus RNA polymerase PA subunit in viral replication is poorly understood, although the enzyme is known to be required for cRNA --> vRNA synthesis. The protease related activity of PA has been discussed ever since protease-inducing activity was demonstrated in transfection experiments. PA protein was highly purified from insect cells infected with the recombinant baculovirus carrying PA cDNA, and a novel chymotrypsin-type serine protease activity was identified with the synthetic peptide, Suc-LLVY-MCA, in the PA protein. [3H]DFP was crosslinked with PA and a mutational analysis revealed that serine624 was as an active site for the protease activity. These results constitute the demonstration of protease activity in PA subunit of the influenza virus RNA polymerase complexes.


Determination of the levels of novel 31-amino acid endothelins and endothelins in human lungs.


Hormonal Control of mRNA Expression of Immunoglobulin Binding Factor in Uterine Cervix

Uterine cervical mucus contains an immunoglobulin binding factor (IgBF). It may play a role in preventing antibody production against sperm in the female reproductive tract. To elucidate the mechanism involved in the production of activated IgBF, we determined the effects of hormones on the expression of mRNAs of IgBF and of protein disulfide isomerase (PDI), activating enzyme, in uterine cervix by quantitative RT-PCR. The uterine cervices of female rats were excised at preovulatory, ovulatory, and postovulatory phases. The human uterine cervical adenocarcinoma cells (TCO-2) were cultured for 24 h in serum-free medium containing 17beta-estradiol or progesterone. Expression of IgBF and PDI mRNAs was significantly highest during the ovulatory phase. 17beta-estradiol stimulated the expression of both mRNAs in TCO-2; whereas progesterone was ineffective. In conclusion, estrogen regulates the production of IgBF by the endocervix and PDI in vivo, thereby increasing the level of activated IgBF in the female reproductive tract during the ovulatory phase, allowing sperm to enter the uterine cavity.

Biochemical and Biophysical Research Communications


インフルエンザウイルス感染と生体防御物質ー感染機序の最近の進歩ー

インフルエンザウイルス感染と生体防御物質ー感染機序の最近の進歩ー


インフルエンザウイルス感染のメカニズムー基礎研究の進歩

インフルエンザウイルス感染のメカニズムー基礎研究の進歩


分子シャペロンによるタンパク質の立体構造の管理とタンパク質分解

分子シャペロンによるタンパク質の立体構造の管理とタンパク質分解


宿主側からみたインフルエンザウイルス感染のメカニズム

宿主側からみたインフルエンザウイルス感染のメカニズム


ウイルス感染の制御因子,細胞性プロテアーゼとプロテアーゼインヒビター

ウイルス感染の制御因子,細胞性プロテアーゼとプロテアーゼインヒビター

タンパク質分解:分子機構と細胞機能

タンパク質分解:分子機構と細胞機能


インフルエンザ感染を制御する生体内プロテアーゼと気道内制御物質

インフルエンザ感染を制御する生体内プロテアーゼと気道内制御物質


Mast Cell Tryptase from Pig Lungs Triggers Infection by Pneumotropic Sendai and Influenza A Viruses (Purification and Characterizatiion

A novel trypsin-type serine proteinase, which processes the precursors of the envelope fusion glycoproteins of pneumotropic Sendai and human influenza A viruses, was purified to homogeneity from pig lungs. On SDS/PAGE, the purified enzyme gave a protein band corresponding to about 32 kDa, and has an apparent molecular mass of 120 kDa, as determined by gel permeation chromatography. Immunohistochemical staining with antibodies against this enzyme revealed that the enzyme is located in pig lung mast cells. The N-terminal 44-amino-acid sequence of the enzyme exhibits about 80% identity with those of mast cell tryptases from other species. Of the inhibitors tested, di-isopropyl fluorophosphate, antipain, leupeptin, benzamidine and a few proteinaceous inhibitors, such as mucus protease inhibitor and aprotinin, inhibited this enzyme activity. Heparin stabilized the enzyme, but high-ionic-strength conditions did not, unlike for human mast cell tryptase. The purified enzyme efficiently processed the fusion glycoprotein precursor of Sendai virus and slowly processed hemagglutinin of human influenza A virus, and triggered the infectivity of Sendai virus in a dose-dependent manner, although human mast cell tryptase beta and rat mast cell tryptase (rat MCP-7) from lungs did not process these fusion glycoproteins at all. These results suggest that mast cell tryptase in pig lungs is the possible trigger of the pneumotropic virus infections.


インフルエンザ感染は克服できるかー分子生物学と酵素学からの挑戦

インフルエンザ感染は克服できるかー分子生物学と酵素学からの挑戦


14-3-3τAssociates with a Translational Control Factor FKBP12-Rapamycin-Associated Protein in T Cells after Stimulation by Pervanadate

Proteins of the 14-3-3 family can associate with and/or modulate the activities of a variety of proteins, such as protooncogene and oncogene products, Cdc25 phosphatases and phosphatidylinositol 3-kinase, and thus are implicated in regulation of signaling pathways and the cell cycle. We report here that treatment of Jurkat T-cells with an inhibitor of protein tyrosine phosphatase, pervanadate, induces the association of 14-3-3tau with a translational control factor, FKBP12-rapamycin-associated protein (FRAP), with significant latter's autophosphorylation. Coimmunoprecipitation of various mutants of FRAP coexpressed with 14-3-3tau in COS-7 cells revealed that 14-3-3tau binds to the C-terminal side of FRAP at unknown site(s) different from the predicted binding motifs to date.


インフルエンザ20世紀の総括

インフルエンザ20世紀の総括


Chymase is a potent chemoattractant for human monocytes and neutrophils

Chymase is a major chymotrypsin-like serine protease expressed in the secretory granules of mast cells in many mammalian species. In this study, we revealed the chemotactic activity of chymase for human mononuclear cells and neutrophils with a 48-well microchemotaxis chamber technique. Human chymase showed the potent chemotactic activity for monocytes and neutrophils dose-dependently in a concentration range from 0.1 to 10 microg/mL, corresponding to about 4-400 microM. The activity was as potent as that of N-formyl-methionyl-leucyl-phenylalanine. Chymase also stimulated cell migration of lymphocytes and purified T cells, but checkerboard analysis revealed that the effect was chemokinetic rather than chemotactic. Inhibition of chymase activities with chymase inhibitors, such as antileukoprotease and Bowman-Birk soybean trypsin inhibitor, significantly inhibited the chemotactic activity of chymase, suggesting that the proteolytic activity of chymase participates in the chemotactic activity. Our results suggest that mast cell chymase acts as a chemoattractant, and may play a role in the accumulation of inflammatory cells in development of the chronic inflammatory responses of allergic and nonallergic diseases.


Comparison of the effects of endothelin-1,-2 and -3(1-31) on changes in [Ca2+]i in human coronary artery smooth muscle cells.


Effect of endothelin-1 (1-31) on intracellular free calcium in cultured human mesangial cells.


Effect of Endothelin (1-31) on Intracellular Free Calcium in Cultured Human Mesangial Cells


Structural analysis of esp-1 gene (PRSS 21),

The esp-1 gene is originally cloned from human eosinophils and encodes a membrane-type serine protease. This gene is ubiquitously expressed in various tissues but not kidney or muscle, and highly expressed in testis. Among granulocytes, this gene is expressed in eosinophils but not neutrophils, although both are derived from myeloid progenitors. In the present study, we have cloned the esp-1 genome using a BAC library, and determined exon-intron junctions: This gene spans approximately 4.6 kb, and consists of 6 exons and 5 introns. On radiation hybrid and FISH analyses, the esp-1 gene was mapped to 16p13.3. In addition, we have cloned a new splicing variant form of esp-1 from a HeLa cell cDNA library, which contains many esp-1 clones. Both RNase protection and primer extension analyses revealed the transcription initiation site of the esp-1 gene is located at nucleotide position -106, residue G. Dual-luciferase reporter analysis revealed a GC-rich region between nucleotide positions, -106 and -189 containing one AP-1/Sp-1 binding site is responsible for the minimum promoter activity in HeLa cells.


Intrinsic Nucleoside Diphosphate Kinase-like Activity is a Novel Function of the 20S Proteasome

The eukaryotic 20 S proteasome is the prototype of a new family of the N-terminal nucleophil hydrolases and is composed of numerous low molecular mass subunits arranged in a stack of four rings, each containing seven different alpha- or beta-subunits. Among the beta-type subunits in the yeast proteasome, three proteolytically active ones were identified, although the functions of the other beta- and alpha-type subunits remain to be clarified. We report here that the purified 20 S proteasome exhibits intrinsic nucleoside diphosphate (NDP) kinase-like activity. The proteasome exhibited a preference for ATP and dATP as phosphate donors, and a broad specificity for NDPs, other than GDP, as phosphate acceptors, unlike conventional NDP kinase, which catalyzes the transfer of gamma-phosphate between NDPs and nucleoside triphosphates. During the transfer of gamma-phosphate, the proteasome formed acid-labile phosphohistidine as autophosphorylated intermediates, and NDP-dependent dephosphorylation of the latter then occurred. These enzymatic properties are similar to those of the molecular chaperone, Hsp70, which also exhibits intrinsic NDP kinase-like activity, instead of ATPase activity. C5 among the beta-type subunits and C8 among the alpha-type subunits were autophosphorylated during the gamma-phosphate transfer reaction and were photoaffinity labeled with 8-azido-[alpha-(32)P]ATP, suggesting that the C5 and C8 subunits of the proteasome are responsible for the NDP kinase-like activity.


Increased levels of ϵ and γIsoform-Specific Increase of 14-3-3 Proteins in Cerebrospinal Fluid of Patients with Creutzfeldt-Jakob Disease


Human Parathyroid Hormone (1-34) Transiently Increases the Excretion of Lysosomal Enzymes into Urine and the Size of Renal Lysosomes

It has been reported that the urinary excretion of N-acetyl-beta-D-glucosaminidase (NAG), a lysosomal enzyme, transiently increases in human after treatment with human parathyroid hormone (hPTH)(1-34). We report here that hPTH(1-34) caused transient changes in the size and density of rat renal lysosomes following urinary excretion of NAG and other lysosomal enzymes tested. Percoll density gradient centrifugation revealed that hPTH(1-34) slightly but significantly increased the fraction of high density lysosomes (around 1.12 g/ml) 5-10 min after the treatment with hPTH(1-34), with a concomitant decrease in the fraction of intermediate density lysosomes (1.07-1.08 g/ml). On electron micrographs, some lysosomes in proximal tubules but not in distal tubules showed a change in morphology from circular to oval, and became enlarged and electron-dense 5-10 min after the treatment with hPTH(1-34). These responses to hPTH(1-34) were also reversible and transient. NAG excreted in urine after treatment with hPTH(1-34) had the molecular mass of a mature form in lysosomes and/or endosomes and was not a prepro-and/or pro-form of the enzyme. Thus, the changes in the density and size of renal lysosomes appear to be associated with the exocytosis of lysosomal enzymes by hPTH(1-34).


Comparison of the Effects of Endothelin-1,-2 and -3 (1-31) on Changes in [Ca2+]i in Human Coronary Artery Smooth Muscle Cells

We have previously found that human chymase selectively cleaves big endothelins (ETs) at the Tyr31-Gly32 bond to produce 31-amino-acid endothelins, ETs (1-31). In the present study, we investigated the effects of ETs (1-31) on changes in intracellular free Ca2+ ([Ca2+]i) in cultured human coronary artery smooth muscle cells (HCASMCs) using confocal laser microscopy. ETs (1-31) increased [Ca2+]i in a concentration-dependent manner. Phosphoramidon did not inhibit the increases in [Ca2+]i caused by ETs (1-31). The [Ca2+]i increases induced by ETs (1-31) were compared to those of ETs (1-21) and big ETs. ET-1 (1-21) was about 10-times more potent than big ET-1 or ET-1 (1-31), whereas big ET-2 was 10-times less potent than ET-2 (1-21) or ET-2 (1-31). ETs (1-31) may induce [Ca2+]i increase through ET(A)-type or ET(A)-type-like receptors. The 10(-12) M ET (1-31)-induced increases in [Ca2+]i were not affected by removal of extracellular Ca2+, but were inhibited by thapsigargin. These results suggested that ET-1, -2 and -3 (1-31) showed similar potencies in increasing [Ca2+]i and mechanisms of ET (1-31)-induced increases in [Ca2+]i may be similar among the three ETs (1-31).


Human Parathyroid Hormone (1-34) Increases Urinary Excretion of Lysosomal Enzymes in Rats

The kidney is the major target of parathyroid hormone (PTH), and PTH influences the urinary excretion of calcium, phosphate and hydrogen ions. It was previously reported that the urinary, excretion of N-acetyl-beta-D-glucosaminidase (NAG), a lysosomal enzyme, transiently increases after human PTH (hPTH) (1-34) infusion in normal subjects and idiopathic hypoparathyroidism patients, but not in pseudohypoparathyroidism type I patients. Here we report that intravenous infusion of hPTH(1-34) to rats transiently increased the urinary excretion of various lysosomal enzymes, such as beta-glucuronidase and acid phosphatase as well as NAG. However, it did not affect the urinary excretion of tubular brush border membrane enzymes, i.e. alkaline phosphatase, leucine aminopeptidase and gamma-glutamyl transpeptidase. Human PTH(1-34) dose-dependently increased the urinary excretion of NAG in rats with a peak at 30 min, which returned to a baseline within 60 min. The increase in the urinary NAG excretion caused by hPTH(1-34) positively correlated with the increase in the urinary cAMP excretion (r = 0.844, p < 0.01), and infusion of dibutyryl cAMP at a dose of 20 mg/kg similarly increased the urinary excretion of NAG. These results suggested that the increase in the urinary excretion of lysosomal enzymes caused by hPTH(1-34) may be a functional response to hPTH(1-34) occurring in the renal tubules via PTH signaling pathway.


Mechanism of Endothelin-1(1-31)-induced Calcium Signaling in Human Coronary Artery Smooth Muscle Cells.


Mast Cell Cause Apoptosis of Cardiomyocytes and Proliferation of Other Intramyocardial Cells In Vitro


Cellular Proteinases Trigger the Infectivity of the Influenza A and Sendai Viruses

It has been proposed that the pathogenicity of the influenza and Sendai virus is primarily determined by host cellular proteases that activate viral infectivity. We isolated trypsin-type serine proteases from rat lungs, candidates for the processing proteases of viral envelope glycoproteins, such as tryptase Clara localized in the Clara cells of the bronchial epithelium and mini-plasmin. These enzymes specifically cleave the precursor of fusion glycoprotein HA of influenza virus at Arg325, and the F0 of Sendai virus at Arg116 in the consensus cleavage motif, Gln(Glu)-X-Arg, resulting in the induction of infectivity of these viruses. Proteolytic activation of viruses by these enzymes occurs extracellularly, probably on the surface and/or in the lumen of the respiratory tract. On the other hand, we isolated two compounds from human bronchial lavage, which inhibit the activity of tryptase Clara. One was a mucus protease inhibitor and the other was a pulmonary surfactant. These compounds inhibited multiple cycles of virus replication in vitro and in vivo, but did not themselves affect the hemagglutination and the infectivity of the virus. Administration of these compounds in the airway may be useful for preventing and treating infection with influenza virus and Sendai virus.


インフルエンザウイルスの感染を制御する気道内酵素とインヒビター

インフルエンザウイルスの感染を制御する気道内酵素とインヒビター


Cellular Proteinases and Viral Infection: Influenza Virus, Sendai Virus and HIV-1


Human Mucus Protease Inhibitor and its Mutants are Novel Defensive Compounds against


次世代のインフルエンザ感染症の治療を考える

次世代のインフルエンザ感染症の治療を考える


Specific Sandwich-type Enzyme Immunoassays for Smooth Muscle Constricting Novel 31-Amino Acid Endothelins

We established highly sensitive and specific sandwich-enzyme immunoassays (EIAs) for three newly discovered bioactive 31-amino acid endothelins [ETs(1-31)], which can detect as little as 0.16 pg/well of ET-1(1-31), 0.39 pg/well of ET-2(1-31), and 0.16 pg/well of ET-3(1-31). The EIAs showed no crossreactivity with 21-amino acid endothelins [ETs(1-21)] or big ETs at the usual assay concentrations below 1-5 ng/ml. In reversed-phase HPLC, immunoreactive ETs(1-31) in the granulocytes of normal human subjects eluted at the exact positions of authentic ETs(1-31), except for the presence of one additional unknown immunoreactive ET-1(1-31). The results also indicate that ETs(1-31) exist in the granulocytes at levels higher than or similar to those of ETs(1-21). This study is the first to establish EIAs for novel bioactive ETs(1-31). These assays can be utilized to assess the pathophysiological roles of ETs(1-31).

Biochemical and Biophysical Research Communications


インフルエンザウイルスとセンダイウイルス感染を制御する細胞性プロテアーゼとプロテアーゼインヒビター


The Extracellular Processing of HIV-1 Envelope Glycoprotein gp160 by Human Plasmin.


Cloning and Tissue Distribution of a Novel Serine Protease esp-1 from Human Eosinophils

We have cloned a novel serine protease designated as esp-1 from human eosinophils. The amino acid sequence deduced from the cDNA showed that ESP-1 comprises a signal peptide of 18 amino acids, a propeptide of 23 amino acids, an active form sequence of 273 amino acids starting from an Ile-Val-Gly-Gly-Glu motif, the catalytic triad of serine proteases that has been characterized as the essential amino acid residues for the proteolytic activity, and a hydrophobic amino acid stretch in the carboxyl terminus, suggesting this enzyme is a novel membrane-type serine protease. The tissue distributions of esp-1 expression revealed that this protease is not only expressed in human eosinophils, but also widely expressed in mononuclear cells and various tissues other than skeletal muscle and kidney and is most abundant in testis and prostate, and moderately so in lung, spleen and pancreas.


Effect of Endothelin-1(1-31) on Extracellular Signal-regulated Kinase and Proliferation of Human Coronary Artery Smooth Muscle Cells

1. We have previously found that human chymase cleaves big endothelins (ETs) at the Tyr31-Gly32 bond and produces 31-amino acid ETs (1-31), without any further degradation products. In this study, we investigated the effect of synthetic ET-1 (1-31) on the proliferation of cultured human coronary artery smooth muscle cells (HCASMCs). 2. ET-1 (1-31) increased [3H]-thymidine incorporation and cell numbers to a similar extent as ET-1 at 100 nM. This ET-1 (1-31)-induced [3H]-thymidine uptake was not affected by phosphoramidon, an inhibitor of ET-converting enzyme. It was, however, inhibited by BQ123, an endothelin ET(A) receptor antagonist, but not by BQ788, an endothelin ET(B) receptor antagonist. 3. By using an in-gel kinase assay, we demonstrated that ET-1 (1-31) activated extracellular signal-regulated kinase 1/2 (ERK1/2) in a concentration-dependent manner (100 pM to 1 microM) in HCASMCs. ET-1 (1-31)-induced ERK1/2 activation was inhibited by BQ123, but not by BQ788 and phosphoramidon. Inhibition of protein kinase C (PKC) and ERK kinase also caused a reduction of ET-1 (1-31)-induced ERK1/2 activation, whereas tyrosine kinase inhibition had little effect. 4. Gel-mobility shift analysis revealed that the ERK1/2 activation was followed by an increase in transcription factor activator protein-1 DNA binding activity in HCASMCs. 5. Our results strongly suggest that ET-1 (1-31) itself stimulates HCASMC proliferation probably through endothelin ET(A) or ET(A)-like receptors. The underlining mechanism of cell growth by ET-1 (1-31) may be explained in part by PKC-dependent ERK1/2 activation. Since human chymase has been proposed to play a role in atherosclerosis, ET-1 (1-31) may be one of the mediators.


Novel 31-Amino Acid-Length Endothelins Cause Constriction of Vascular Smooth Muscle

We have reported that human chymase specifically cleaves big endothelins (ETs) at the Try31-Gly32 bond, and produces novel trachea-constricting 31-amino-acid-length ETs, ETs(1-31). In this study, we investigated the effect of synthetic ETs(1-31) on the contractile activity toward porcine coronary arteries and rat aortae. Although ETs(1-31) exhibited less potent vasoconstrictile activity in these tissues than 21-amino-acid-length ETs(1-21), or a similar extent, ET-1(1-31) caused significantly slower-developing and longer-lasting contraction than ETs(1-21). The ETA receptor antagonist, BQ485, completely inhibited the activity of ET-1(1-31). The ETB receptor antagonist, BQ788, also inhibited the activity of ET-1(1-31) toward rat aortae more efficiently than that ET-1(1-21). Therefore, trachea-constricting peptides ETs(1-31) play roles as vasoconstrictors in a different manner from ETs(1-21).


The Structure of Asparagine-linked Oligosaccharide of Rat Liver Cathepsin L Reflect the Substrate Specificity of Lysosomal Alpha-Mannosidase

We have studied the structures of asparagine-linked oligosaccharides of cathepsin L purified from rat liver in detail. The oligosaccharides released from rat liver cathepsin L on glycopeptidase-F treatment were tagged with 2-aminopyridine at their reducing ends. The pyridylamino (PA) derivatives were separated into seven fractions according to molecular size by normal-phase HPLC. The structure of each oligosaccharide thus isolated was analyzed by reversed-phase HPLC and characterized by ion-spray mass spectrometry and high-resolution proton nuclear magnetic resonance (1H-NMR) spectroscopy. Our results indicate that the asparagine-linked oligosaccharides of rat liver cathepsin L are of the oligomannose type, having two to six mannose residues. Among them, the five major ones are Manalpha1-6Manbeta1-4-GlcNAcbeta1-4GlcNAc, Manalpha1 -6Manalpha1-6Manbeta1-4GIcNAcbeta1-4GlcNAc, Manalpha1-6(Manalpha1-3)-Manalpha1-6Manbeta1- 4GlcNAcbeta1-4GlcNAc, Manalpha1-6(Manalpha1-3)Manalpha1-6(Manalpha1-3) Manbeta1-4Glc-NAcbeta1-4GlcNAc, and Manalpha1-6(Manalpha1-3)Manalpha1-6(Manalpha1-++ +2Manalpha1-3)Manbeta1-4GlcNAcbeta1-4Glc-NAc. Their structures are shown to be products of Man6GlcNAc2 hydrolysis with lysosomal alpha-mannosidase.


Enzymatic Activation of Immunoglobulin Binding Factor in Female Reproductive Tract

Human seminal plasma and cervical mucus contains an immunoglobulin binding factor (IgBF) which interacts with IgG as monomers under reducing condition. It may play a role in preventing antibody production against allogeneic sperms in the female reproductive tract. However, since IgBF is secreted as a homodimer that does not bind IgG, in vivo activation systems should be investigated. GSH reduces the inactive native dimer to the active monomer. Protein disulfide isomerase (PDI), a molecular chaperone, alters the configuration of dimers to active monomers. 20S proteasomes produced by activated T cells which cleave the dimers in the presence of GSH to active fragments. All these activating systems are widely distributed as cellular enzymes in vivo. Also PDI mRNAs are expressed in uterine cervix, endometrium and fallopian tube. Since these enzymes are produced upon stimulation by the immune system, we hypothesize that immunocompetent cells interact with allogeneic sperms, leading to the local production of these enzymes that will activate IgBF.


Mast Cell Tryptase Increases not Only the Proliferation of Human Dermal Fibroblast but Also Type I Collagen Production


インフルエンザを,めぐるトピックス

インフルエンザを,めぐるトピックス


Endothelin-1 (1-31), A Novel Vasoactive Peptide Increases [Ca2+ ]i in Human Coronary Artery Smooth Muscle Cells

We have previously found that human chymase cleaves big endothelins at the Tyr31-Gly32 bond and produces 31-amino acid long endothelins-(1-31), without any further degradation products. In this study, we investigated the effect of synthetic endothelin-1-(1-31) on the intracellular free Ca2+ concentration ([Ca2+]i) in cultured human coronary artery smooth muscle cells. Endothelin-1-(1-31) increased [Ca2+]i in a concentration-dependent manner (10(-14) to 10(-10) M). This endothelin-1-(1-31)-induced [Ca2+]i increase was not affected by phosphoramidon (N-(alpha-Rhamnopyranosyloxyhydroxyphosphinyl)-L-Leucyl-L-Tryptoph an), an inhibitor of endothelin-converting enzyme. It was, however, inhibited by 10(-10) M BQ123 (Cyclo-(-D-Trp-D-Asp(ONa)-Pro-D-Val-Leu-)), an endothelin ET(A) receptor antagonist, but not by 10(-10) M BQ788 (N-cis-2,6-dimethylpiperidinocarbonyl-L-yMeLeu-D-Trp(COOM e)-D-Nle-ONa), an endothelin ET(B) receptor antagonist. These results suggest that endothelin-1-(1-31) by itself exhibits vasoactive properties probably through endothelin ET(A) receptors. Since human chymase has been reported to play a role in atherosclerosis, endothelin-1-(1-31) may be one of the candidate substances for its cause.


Human Chymase as the Enzyme Forming Novel Bioactive 31-Amino Acid Length Endothelins

We report the novel role of human chymase in the production of bioactive 31-amino acid length endothelins (ETs), which may play a role in allergies and vascular diseases. In the bronchi of asthmatic patients, the vascular tissue in atherosclerosis, and the heart muscle in cardiac hypertrophy, both ET-like immunoreactivity and the accumulation of mast cells significantly increase. Chymase from human mast cells selectively cleaves big ET-1, -2 and -3 at their Tyr31-Gly32 bonds, and produces novel bioactive 31-amino acid length ETs, ETs(1-31), without any further degradation products. However, chymases from other species, human cathepsin G, and porcine alpha-chymotrypsin, degrade big ETs. ETs(1-31) at concentrations between 10(-9) M and 10(-7) M exhibited various contractile potencies in rat tracheae and porcine coronary arteries in a dose-dependent manner. Furthermore, ET-1(1-31) at concentrations between 10(-14) M and 10(-10) M caused a significant increase in the intracellular free Ca2+ concentration. The contractile activity of ETs(1-31) may not be the consequence of conversion to the corresponding ETs(1-21) by phosphoramidon-sensitive ET converting enzyme(s) or other chymotrypsin-type proteases and metallo-endopeptidases, because the contractile activity was not significantly inhibited on treatment with inhibitors of these proteases prior to the addition of ET-1(1-31).


ヒト粘液プロテアーゼインヒビターによるインフルエンザウイルスの感染抑制

ヒト粘液プロテアーゼインヒビターによるインフルエンザウイルスの感染抑制


Intrinsic ADP-ATP Exchange Activity is a Novel function of the Molecular Chaperone, Hsp70

Hsp70 is a multifunctional molecular chaperone whose interactions with protein substrates are regulated by ATP hydrolysis and ADP-ATP exchange. We show here that, in addition to ATPase activity, purified Hsp70 free from nucleoside-diphosphate (NDP) kinase exhibits intrinsic ADP-ATP exchange activity. The rate constants for ATP hydrolysis and ATP synthesis were in a similar range at the optimum pH of 7.5-8.5 in the presence of 5 mM ATP and 0.5 mM ADP. Hsp70 exhibited a considerably strict preference for ATP as a phosphate donor, and a biased substrate specificity, unlike NDP kinase; ADP, UDP, CDP > dTDP, dCDP > GDP, dGDP. During the reaction, Hsp70 formed an acid-labile autophosphorylated intermediate, and nucleoside diphosphate-dependent dephosphorylation of the latter then occurred. These properties of Hsp70 are not identical but similar to those of NDP kinase, but are not similar to those of adenylate kinase and ATP synthase.


Endothelin-1(1-31), a novel vasoactive peptide, increases [Ca2+]i in humen coronary artery smooth muscle cells.


Effect of endothelin-1(1-31)on extracellular signal-regulated kinase and proliferation of human coronary artery smooth muscle cells.


Human chymase, an enzyme forming novel bioactive 31-amino acid length endothelins.


Inhibition of Tryptase TL2 from Human T4+lymphocytes and Inhibition of HIV-1 Replication in H9 Cells by Recombinant Aprotinin and Bikunin Homologues

The serine esterase TL2 from human T4+ lymphocytes is a binding component to HIV-1 glycoprotein gp120 and seems to play a role in the HIV-1 infection mechanism. Recombinant variants of the Kunitz-type serine proteinase inhibitor aprotinin were investigated for their ability to inhibit tryptase TL2 and the binding of gp120 to this enzyme. Furthermore, the viral replication of HIV-1 was investigated H9 cell cultures under the influence of recombinant aprotinin and bikunin variants. In contrast to native aprotinin, the recombinant variant [Arg15, Phe17, Glu52] aprotinin with a reactive-site sequence homologous to the V3 loop of HIV-1 gp120 showed a specific inhibition of tryptase TL2 (> 80%). However, the [Leu15, Phe17, Glu52] aprotinin variant with hydrophobic subsites was the most potent inhibitor of the binding of gp120 to tryptase TL2 (68%). Our results show that the enzyme activity of purified tryptase TL2 is inhibited not only by variants with basic amino acids, but also those with hydrophobic residues in the reactive-site region. Therefore, tryptase TL2 is not a typical trypsin-like or chymotrypsin-like protease. Investigations on inhibition of HIV-1 replication in H9 cell cultures showed that tryptase TL2 is involved in the mechanism of virus internalization into human lymphocytes. The [Leu15, Phe17, Glu52] aprotinin showed a significant retardation of syncytium formation over a period of 5 days in a 1 micro M concentration. Similar investigations were performed with recombinant variants of bikunin, the light chain of human inter-alpha-trypsin inhibitor. Only the single-headed variant [Arg94] delta 2 bikunin inhibited slightly the syncytium formation over a period of 2 days in a 2.2 micro M concentration. Wild-type bikunin and all full-length variants showed no effect, possibly due to steric hindrance by the second domain of the double-headed inhibitor.


Intrinsic Nucleoside Diphosphate Kinase-like Activity as a Novel Function of 14-3-3 Proteins


Human Mucus Protease Inhibitor and its Mutants Prevent Infection by Influenza A and Sendai Viruses

Medical Aspects of Proteases and Protease Inhibitors


Selective Conversion of Big Endothelins to Tracheal Smooth Muscle-Constricting 31-Amino Acid Length Endothelins by Chymase from Human Mast Cells

Chymase from human mast cells selectively cleaved big endothelins (ETs) at the Tyr31-Gly32 bond and produced novel trachea-constricting 31-amino acid-length endothelins, ETs(1-31), without any further degradation products. Chymases from other species, such as the enzymes from rat connective tissue and mucosal mast cells, and the other chymotrypsin-like proteases examined degraded big ETs. ETs(1-31) exhibited various contractile potencies as to the rat trachea in comparison with 21-amino acid-length endothelins, ETs(1-21), and big ETs: ET-1(1-21) > ET-1(1-31) > big ET-1; ET-2(1-31) > ET-2(1-21) > or = big ET-2; ET-3(1-21) > or = ET-3(1-31) > or = big ET-3. Among the ETs(1-31), ET-2(1-31) was the most potent constrictor, its potency being similar to that of ET-1(1-21) and stronger than that of ET-2(1-21). The contractile activity of ETs(1-31) may not be the consequence of conversion to the corresponding ETs(1-21) by phosphoramidon-sensitive ET-converting enzymes or other chymotrypsin-type proteases and metalloendopeptidases, because the contractile activity was not inhibited significantly on treatment with inhibitors of these proteases before the addition of ET-1(1-31). Inhibitors of chymotrypsin-type serine proteases, on the contrary, significantly enhanced the contractile activity exhibited by ET-1(1-31) and big ET-1, but not that by ET-1(1-21). These results suggest that protease(s) on the surface of the rat trachea tends to degrade ETs(1-31) and big ETs, and thereby reduces their contractile activity. Taken together, the results suggest that trachea-constricting ETs(1-31) generated by human chymase may play a role in the hyper-responsive airway in allergic inflammation.


Structure Studies on the Carbohydrate Moiety of RatLliver Cathepsin L


Protease Inhibitors and a Pulmonary Surfactant in Airway Fluid are Potential Defensive


ウイルス感染を制御する細胞性プロテアーゼとプロテアーゼインヒビター(インフルエンザとエイズウイルスを中心として)


Molecular Basis of Proteolytic Activation of Sendai Virus Infection and the Defensive


HIV-1 の標的細胞認識と感染機序

HIV-1 の標的細胞認識と感染機序

HIV-1 感染による神経障害の診療マニュアル

HIV-1 感染による神経障害の診療マニュアル


Human Mucus Protease Inhibitor in Airway Fluids Is a Potential Defensive Compound against Infection with Influenza A and Sendai Viruses

Tryptase Clara, a trypsin-like protease localized exclusively in and secreted from Clara cells to the bronchial epithelium of rat, proteolytically activates the infectivity of influenza A virus [H. Kido, Y. Yokogoshi, K. Sakai, M. Tashiro, Y. Kishino, A. Fukutomi, and N. Katunuma (1992) J. Biol. Chem. 267, 13573-13579]. We report here that human mucus protease inhibitor (MPI), a major inhibitor of granulocyte elastase in the lining fluids of the human respiratory tract, significantly inhibited proteolytic activation of the infectivity of influenza A and Sendai viruses by tryptase Clara in vitro and multi-cycles of mouse-adapted influenza A virus replication in rat lungs in vitro. Recombinant MPI and the C- but not the N-terminal domain of the MPI inhibited both the proteolytic activity of tryptase Clara and the activation of virus infection. The 50% inhibitory concentrations of recombinant MPI and the C-terminal domain for tryptase Clara with Sendai virus envelope glycoprotein as substrate were 7.4 and 61.6 nM, respectively. These results indicate that MPI is a defensive compound against virus infection. Since there is evidence suggesting that concentrations of MPI in respiratory fluids are insufficient for prevention of virus infection, administration of MPI in the airway may be useful for treatment of these virus infections.


Proteolytic Activation of the Precursor of Membrane Type 1 Matrix Metalloproteinase by Human Plasmin


Inhibitory Effect of Pulmonary Surfactant on Sendai Virus Infection in Rat Lungs