Impaired expansion of regulatory T cells in a neonatal thymectomy-induced autoimmune mouse model.

Neonatal thymectomy in certain mouse strains is known to induce organ-specific autoimmunity due to impaired functions of T cells, including Foxp3(+) regulatory T (Treg) cells in the thymus. The precise mechanism underlying the induction of autoimmunity by neonatal thymectomy remains unclear. One possibility is that depletion of Treg cells breaks down peripheral tolerance. We examined the functions of Treg cells by using a murine Sjögren syndrome model of NFS/sld mice that underwent neonatal thymectomy. The ratio of Treg cells to effector memory phenotype T cells in thymectomy mice was significantly lower than that of nonthymectomy mice. In addition, in vitro induction of peripherally induced Treg cells by transforming growth factor-β (TGF-β) using naive T cells from Sjögren syndrome model mice was severely impaired. The mRNA expression of TGF-β receptor I and II and Smad3 and -4 in the TGF-β-induced signal transduction pathway of Treg cells in this Sjögren syndrome model were lower than those of control mice. In addition, Treg cells in this Sjögren syndrome model exhibited an interferon-γ-producing Th1-like phenotype that resembled effector T cells. In conclusion, these results suggest that abnormal expansion and differentiation of Treg cells and inflammatory cytokines produced by Treg cells contribute to the development of autoimmunity.


Aromatase controls Sjögren syndrome-like lesions through monocyte chemotactic protein-1 in target organ and adipose tissue-associated macrophages.

Several autoimmune diseases are known to develop in postmenopausal women. However, the mechanism by which estrogen deficiency influences autoimmunity is unknown. Aromatase is an enzyme that converts androgens to estrogens. Herein, we used female aromatase gene knockout (ArKO) mice as a model of estrogen deficiency to investigate the molecular mechanism that underlies the onset and development of autoimmunity. Histological analyses showed that inflammatory lesions in the lacrimal and salivary glands of ArKO mice increased with age. Adoptive transfer of spleen cells or bone marrow cells from ArKO mice into recombination activating gene 2 knockout mice failed to induce the autoimmune lesions. Expression of mRNA encoding proinflammatory cytokines and monocyte chemotactic protein-1 increased in white adipose tissue of ArKO mice and was significantly higher than that in wild-type mice. Moreover, an increased number of inflammatory M1 macrophages was observed in white adipose tissue of ArKO mice. A significantly increased monocyte chemotactic protein-1 mRNA expression of the salivary gland tissue in ArKO was found together with adiposity. Furthermore, the autoimmune lesions in a murine model of Sjögren syndrome were exacerbated by administration of an aromatase inhibitor. These results suggest that aromatase may play a key role in the pathogenesis of Sjögren syndrome-like lesions by controlling the target organ and adipose tissue-associated macrophage.


Anti-Inflammatory Effects of Rebamipide Eyedrop Administration on Ocular Lesions in a Murine Model of Primary Sjögren's Syndrome.

Topical therapy is effective for dry eye, and its prolonged effects should help in maintaining the quality of life of patients with dry eye. We previously reported that the oral administration of rebamipide (Reb), a mucosal protective agent, had a potent therapeutic effect on autoimmune lesions in a murine model of Sjögren's syndrome (SS). However, the effects of topical treatment with Reb eyedrops on the ocular lesions in the murine model of SS are unknown. Reb eyedrops were administered to the murine model of SS aged 4-8 weeks four times daily. Inflammatory lesions of the extraorbital and intraorbital lacrimal glands and Harderian gland tissues were histologically evaluated. The direct effects of Reb on the lacrimal glands were analyzed using cultured lacrimal gland cells. Tear secretions of Reb-treated mice were significantly increased compared with those of untreated mice. In addition to the therapeutic effect of Reb treatment on keratoconjunctivitis, severe inflammatory lesions of intraorbital lacrimal gland tissues in this model of SS were resolved. The mRNA expression levels of IL-10 and mucin 5Ac in conjunctival tissues from Reb-treated mice was significantly increased compared with those of control mice. Moreover, lactoferrin production from lacrimal gland cells was restored by Reb treatment. Topical Reb administration had an anti-inflammatory effect on the ocular autoimmune lesions in the murine model of SS and a protective effect on the ocular surfaces.


A critical role for thymic stromal lymphopoietin in nickel-induced allergy in mice.

Ni is the most frequent cause of contact allergy induced by metals. However, the underlying mechanism of this induction is unknown. Our previous research demonstrates that activation of dendritic cells (DCs) through p38MAPK/MKK6 is required for Ni-induced allergy in mice. In the current study, we investigated the cellular and molecular mechanisms underlying Ni-induced allergy using a mouse model that involves injecting Ni into the ear, with or without Freund's incomplete or complete adjuvants. Nickel had greater potential to cause allergic reactions compared with palladium and gold. Among the proteins expressed at higher levels in mice with Ni-induced allergy, we focused on thymic stromal lymphopoietin (TSLP), which is produced in abundance by keratinocytes. We detected increased expression of the TSLP receptor (TSLPR) in DCs from cervical lymph nodes of mice with Ni-induced allergy, suggesting that DCs in ear tissues were activated through TSLPR signaling induced by keratinocyte-derived TSLP. Furthermore, delayed-type hypersensitivity reactions in mice with Ni-induced allergy were decreased significantly by injection of a Tslp-short interfering RNA along with atelocollagen in the ear skin. These results suggest that Ni allergy may be triggered by a TSLP/TSLPR-mediated interaction between epithelial and immune cells.


Effects of Free Fatty Acids on Human Salivary Gland Epithelial Cells.

Obesity and type 2 diabetes (T2D) are characterized by decreased insulin sensitivity and higher concentrations of free fatty acids (FFAs) in plasma. Among FFAs, saturated fatty acids (SFAs), such as palmitate, have been proposed to promote inflammatory responses. Primary Sjögren's syndrome (SS) is an autoimmune disease characterized by inflammatory mononuclear cell infiltration and destruction of epithelial cells in the salivary and lacrimal glands. IL-6 production and -fodrin degradation are increased in salivary gland epithelial cells of patients with primary SS. Although previous studies have shown a link between SS and either dyslipidemia or T2D, little is known about the clinical significance of FFAs in primary SS. Here we report that SFAs, but not unsaturated fatty acids, induced IL-6 production via NF-B and p38 MAPK activation in human salivary gland epithelial cells. Moreover, palmitate induced apoptosis and -fodrin degradation by caspase-3 activation. Unlike salivary gland epithelial cells, induction of IL-6 production and the degradation of -fodrin in response to palmitate were undetectable in squamous carcinoma cells and keratinocytes. Taken together, SFAs induced IL-6 production and -fodrin degradation in salivary gland epithelial cells, implicating a potential link between the pathogenesis of primary SS and SFAs level in plasma.


Induction of Rapid T Cell Death and Phagocytic Activity by Fas-Deficient lpr Macrophages.

Peripheral T cells are maintained by the apoptosis of activated T cells through the Fas-Fas ligand system. Although it is well known that normal T cells fail to survive in the Fas-deficient immune condition, the molecular mechanism for the phenomenon has yet to be elucidated. In this study, we demonstrate that rapid cell death and clearance of normal T cells were induced by Fas-deficient lpr macrophages. Transfer of normal T cells into lpr mice revealed that Fas expression on donor T cells was promptly enhanced through the IFN-/IFN-R. In addition, Fas ligand expression and phagocytic activity of lpr macrophages were promoted through increased NF-B activation. Controlling Fas expression on macrophages plays an essential role in maintaining T cell homeostasis in the peripheral immune system. Our data suggest a critical implication to the therapeutic strategies such as transplantation and immunotherapy for immune disorder or autoimmunity related to abnormal Fas expression.


Fas-Independent T-Cell Apoptosis by Dendritic Cells Controls Autoimmune Arthritis in MRL/lpr Mice

BACKGROUND: Although autoimmunity in MRL/lpr mice occurs due to a defect in Fas-mediated cell death of T cells, the role of Fas-independent apoptosis in pathogenesis has rarely been investigated. We have recently reported that receptor activator of nuclear factor (NF)-B ligand (RANKL)-activated dendritic cells (DCs) play a key role in the pathogenesis of rheumatoid arthritis (RA) in MRL/lpr mice. We here attempted to establish a new therapeutic strategy with RANKL-activated DCs in RA by controlling apoptosis of peripheral T cells. Repeated transfer of RANKL-activated DCs into MRL/lpr mice was tested to determine whether this had a therapeutic effect on autoimmunity. METHODS AND FINDING: Cellular and molecular mechanisms of Fas-independent apoptosis of T cells induced by the DCs were investigated by in vitro and in vivo analyses. We demonstrated that repeated transfers of RANKL-activated DCs into MRL/lpr mice resulted in therapeutic effects on RA lesions and lymphoproliferation due to declines of CD4(+) T, B, and CD4(-)CD8(-) double negative (DN) T cells. We also found that the Fas-independent T-cell apoptosis was induced by a direct interaction between tumor necrosis factor (TNF)-related apoptosis-inducing ligand-receptor 2 (TRAIL-R2) on T cells and TRAIL on Fas-deficient DCs in MRL/lpr mice. CONCLUSION: These results strongly suggest that a novel Fas-independent apoptosis pathway in T cells maintains peripheral tolerance and thus controls autoimmunity in MRL/lpr mice.


CCR7 with S1P1 signaling through AP-1 for migration of Foxp3+ regulatory T-cells controls autoimmune exocrinopathy.

Forkhead box p3-positive (Foxp3(+)) regulatory T cells (T(reg) cells) participate in maintaining peripheral immune tolerance and suppressing autoimmunity. We recently reported that in situ patrolling by C-C-chemokine receptor 7 (CCR7)(+) T(reg) cells in target organs is essential for controlling autoimmune lesions in Sjögren's syndrome. In the present study, the molecular mechanism underlying CCR7-mediated T(reg) cell migration was investigated in a mouse model. The impaired migratory response of Ccr7(-/-) T(reg) cells to sphingosine 1-phosphate (S1P) occurred because of defective association of S1P receptor 1 (S1P(1)) with a G coupled-protein. In addition, T-cell receptor (TCR)- and S1P(1)-mediated Ras-related C3 botulinum toxin substrate 1 (Rac-1), extracellular signal-related kinase (ERK), and c-Jun phosphorylation required for activator protein 1 (AP-1) transcriptional activity were significantly impaired in Ccr7(-/-) T(reg) cells. Surprisingly, the abnormal nuclear localization of Foxp3 was detected after abrogation of the c-Jun and Foxp3 interaction in the nucleus of Ccr7(-/-) T(reg) cells. These results indicate that CCR7 essentially controls the migratory function of T(reg) cells through S1P(1)-mediated AP-1 signaling, which is regulated through its interaction with Foxp3 in the nucleus.


A Novel DC Therapy with Manipulation of MKK6 Gene on Nickel Allergy in Mice

BACKGROUND: Although the activation of dermal dendritic cells (DCs) or Langerhans cells (LCs) via p38 mitogen-activated protein kinase (MAPK) plays a crucial role in the pathogenesis of metal allergy, the in vivo molecular mechanisms have not been identified and a possible therapeutic strategy using the control of dermal DCs or LCs has not been established. In this study, we focused on dermal DCs to define the in vivo mechanisms of metal allergy pathogenesis in a mouse nickel (Ni) allergy model. The effects of DC therapy on Ni allergic responses were also investigated. METHODS AND FINDING: The activation of dermal DCs via p38 MAPK triggered a T cell-mediated allergic immune response in this model. In the MAPK signaling cascade in DCs, Ni potently phosphorylated MAP kinase kinase 6 (MKK6) following increased DC activation. Ni-stimulated DCs could prime T cell activation to induce Ni allergy. Interestingly, when MKK6 gene-transfected DCs were transferred into the model mice, a more pronounced allergic reaction was observed. In addition, injection of short interfering (si) RNA targeting the MKK6 gene protected against a hypersensitivity reaction after Ni immunization. The cooperative action between T cell activation and MKK6-mediated DC activation by Ni played an important role in the development of Ni allergy. CONCLUSIONS: DC activation by Ni played an important role in the development of Ni allergy. Manipulating the MKK6 gene in DCs may be a good therapeutic strategy for dermal Ni allergy.


Aire-dependent production of XCL1 mediates medullary accumulation of thymic dendritic cells and contributes to regulatory T cell development

Dendritic cells (DCs) in the thymus (tDCs) are predominantly accumulated in the medulla and contribute to the establishment of self-tolerance. However, how the medullary accumulation of tDCs is regulated and involved in self-tolerance is unclear. We show that the chemokine receptor XCR1 is expressed by tDCs, whereas medullary thymic epithelial cells (mTECs) express the ligand XCL1. XCL1-deficient mice are defective in the medullary accumulation of tDCs and the thymic generation of naturally occurring regulatory T cells (nT reg cells). Thymocytes from XCL1-deficient mice elicit dacryoadenitis in nude mice. mTEC expression of XCL1, tDC medullary accumulation, and nT reg cell generation are diminished in Aire-deficient mice. These results indicate that the XCL1-mediated medullary accumulation of tDCs contributes to nT reg cell development and is regulated by Aire.


Atelocollagen-mediated systemic administration of myostatin-targeting siRNA improves muscular atrophy in caveolin-3-deficient mice.

Small interfering RNA (siRNA)-mediated silencing of gene expression is rapidly becoming a powerful tool for molecular therapy. However, the rapid degradation of siRNAs and their limited duration of activity require efficient delivery methods. Atelocollagen (ATCOL)-mediated administration of siRNAs is a promising approach to disease treatment, including muscular atrophy. Herein, we report that ATCOL-mediated systemic administration of a myostatin-targeting siRNA into a caveolin-3-deficient mouse model of limb-girdle muscular dystrophy 1C (LGMD1C) induced a marked increase in muscle mass and a significant recovery of contractile force. These results provide evidence that ATCOL-mediated systemic administration of siRNAs may be a powerful therapeutic tool for disease treatment, including muscular atrophy.


Delivery of small interfering RNA with a synthetic collagen poly(Pro-Hyp-Gly) for gene silencing in vitro and in vivo.

Silencing gene expression by small interfering RNAs (siRNAs) has become a powerful tool for the genetic analysis of many animals. However, the rapid degradation of siRNA and the limited duration of its action in vivo have called for an efficient delivery technology. Here, we describe that siRNA complexed with a synthetic collagen poly(Pro-Hyp-Gly) (SYCOL) is resistant to nucleases and is efficiently transferred into cells in vitro and in vivo, thereby allowing long-term gene silencing in vivo. We found that the SYCOL-mediated local application of siRNA targeting myostatin, coding a negative regulator of skeletal muscle growth, in mouse skeletal muscles, caused a marked increase in the muscle mass within a few weeks after application. Furthermore, in vivo administration of an anti-luciferase siRNA/SYCOL complex partially reduced luciferase expression in xenografted tumors in vivo. These results indicate a SYCOL-based non-viral delivery method could be a reliable simple approach to knockdown gene expression by RNAi in vivo as well as in vitro.


Inflammatory disease and cancer with a decrease in Kupffer cell numbers in Nucling-knockout mice.

Nucling is a stress-inducible protein associated with apoptosomes. The cytochrome c-triggered formation of apoptosomes represents a key-initiating event in apoptosis. We have recently reported that Nucling regulates the apoptotic pathway by controlling the activation of NF-kappaB as well. Here we show that hepatocellular carcinoma (HCC) arising spontaneously against a background of hepatitis occurred more frequently in Nucling-knockout (KO) mice than wild-type (WT) mice. Biochemical serum testing revealed potential liver dysfunction with hypercholesterolemia in Nucling-KO males. In the background of Nucling-KO mice, we observed the up-regulation of TNFalpha, spontaneous NF-kappaB-activation and the induction of galectin-3 expression in liver. In addition, we observed a decrease in the number of Kupffer cells (KCs) in the KO mice. KCs are important for the hepatic immune system, acting as phagocytes or antigen-presenting cells (APCs). We found that KCs in Nucling-KO mice were apoptotic possibly through the up-regulation of TNFalpha. These observations indicate that Nucling is important for the regulation of NF-kappaB signals in liver. We propose that Nucling deficiency could be a powerful tool to reveal the NF-kappaB-related molecular networks leading to hepatitis and HCC development.


切除からインプラントを維持源としたエピテーゼまで一貫治療を行った上顎洞悪性線維性組織球腫の1例


新生児におけるダイオキシンへの曝露と自己免疫病の発生

新生児におけるダイオキシンへの曝露と自己免疫病の発生


In situ Patrolling of Regulatory T cells is Essential for Protecting Autoimmune Exocrinopathy

Migration of T cells, including regulatory T (Treg) cells, into the secondary lymph organs is critically controlled by chemokines and adhesion molecules. However, the mechanisms by which Treg cells regulate organ-specific autoimmunity via these molecules remain unclear. Although we previously reported autoimmune exocrinopathy resembling Sjögren's syndrome (SS) in the lacrimal and salivary glands from C-C chemokine receptor 7 (CCR7)-deficient mice, it is still unclear whether CCR7 signaling might specifically affect the dynamics and functions of Treg cells in vivo. We therefore investigated the cellular mechanism for suppressive function of Treg cells via CCR7 in autoimmunity using mouse models and human samples. Patrolling Treg cells were detected in the exocrine organs such as lacrimal and salivary glands from normal mice that tend to be targets for autoimmunity while the Treg cells were almost undetectable in the exocrine glands of CCR7(-/-) mice. In addition, we found the significantly increased retention of CD4(+)CD25(+)Foxp3(+) Treg cells in the lymph nodes of CCR7(-/-) mice with aging. Although Treg cell egress requires sphingosine 1-phosphate (S1P), chemotactic function to S1P of CCR7-/- Treg cells was impaired compared with that of WT Treg cells. Moreover, the in vivo suppression activity was remarkably diminished in CCR7(-/-) Treg cells in the model where Treg cells were co-transferred with CCR7(-/-) CD25(-)CD4(+) T cells into Rag2(-/-) mice. Finally, confocal analysis showed that CCR7(+)Treg cells were detectable in normal salivary glands while the number of CCR7(+)Treg cells was extremely decreased in the tissues from patients with Sjögren's syndrome. These results indicate that CCR7 essentially governs the patrolling functions of Treg cells by controlling the traffic to the exocrine organs for protecting autoimmunity. Characterization of this cellular mechanism could have clinical implications by supporting development of new diagnosis or treatments for the organ-specific autoimmune diseases such as Sjögren's syndrome and clarifying how the local immune system regulates autoimmunity.


Cathepsin L inhivition prevents murine autoimmune diabetes via suppression of CD8+ T cell activity.

Type 1 diabetes (T1D) is an autoimmune disease resulting from defects in central and peripheral tolerance and characterized by T cell-mediated destruction of islet β cells. To determine whether specific lysosomal proteases might influence the outcome of a T cell-mediated autoimmune response, we examined the functional significance of cathepsin inhibition on autoimmune T1D-prone non-obese diabetic (NOD) mice. Here it was found that specific inhibition of cathepsin L affords strong protection from cyclophosphamide (CY)-induced insulitis and diabetes of NOD mice at the advanced stage of CD8(+) T cell infiltration via inhibiting granzyme activity. It was discovered that cathepsin L inhibition prevents cytotoxic activity of CD8(+) T cells in the pancreatic islets through controlling dipeptidyl peptidase I activity. Moreover, the gene targeting for cathepsin L with application of in vivo siRNA administration successfully prevented CY-induced diabetes of NOD mice. Finally, cathepsin L mRNA expression of peripheral CD8(+) T cells from NOD mice developing spontaneous T1D was significantly increased compared with that from control mice. Our results identified a novel function of cathepsin L as an enzyme whose activity is essential for the progression of CD8(+) T cell-mediated autoimmune diabetes, and inhibition of cathepsin L as a powerful therapeutic strategy for autoimmune diabetes.


Recent evidences suggest that the apoptotic pathway plays a central role in tolerazing T cells to tissue-specific self antigen, and may drive the autoimmune phenomenon in the salivary glands. We found that retinoblastoma-associated protein RbAp48 overexpression induces p53-mediated apoptosis in the salivary glands caused by estrogen deficiency. We demonstrated that transgenic (Tg) expression of RbAp48 resulted in the development of autoimmune exocrinopathy resembling Sjögren's syndrome (SS). CD4(+)T cell-mediated autoimmune lesions in the salivary glands were aggravated with age, in association with autoantibody productions. We obtained evidences that salivary epithelial cells can produce interferon-gamma (IFN-gamma) besides interleukin (IL)-18, which activates interferon regulatory factor-1 (IRF-1), and class II transactivator (CIITA). Indeed, the autoimmune lesions into Rag2(-/-) mice were induced by the adoptive transfer of lymph node cells from RbAp48-Tg mice. These results indicate a novel immunocompetent role of epithelial cells that can produce IFN-gamma, resulting in loss of local tolerance prior to developing gender-based autoimmunity. The studies reviewed the molecular mechanisms on the development of salivary gland autoimmunity, and gender-related differences in SS.

The Journal of Medical Investigation : JMI


Sjögren症候群の発症とエストロゲン

Sjögren症候群の発症とエストロゲン


Real-time in vivo imaging of p16Ink4a reveals cross-talk with p53

Expression of the p16(Ink4a) tumor suppressor gene, a sensor of oncogenic stress, is up-regulated by a variety of potentially oncogenic stimuli in cultured primary cells. However, because p16(Ink4a) expression is also induced by tissue culture stress, physiological mechanisms regulating p16(Ink4a) expression remain unclear. To eliminate any potential problems arising from tissue culture-imposed stress, we used bioluminescence imaging for noninvasive and real-time analysis of p16(Ink4a) expression under various physiological conditions in living mice. In this study, we show that oncogenic insults such as ras activation provoke epigenetic derepression of p16(Ink4a) expression through reduction of DNMT1 (DNA methyl transferase 1) levels as a DNA damage response in vivo. This pathway is accelerated in the absence of p53, indicating that p53 normally holds the p16(Ink4a) response in check. These results unveil a backup tumor suppressor role for p16(Ink4a) in the event of p53 inactivation, expanding our understanding of how p16(Ink4a) expression is regulated in vivo.


YKL-40 secreted from adipose tissue inhibits degradation of type I collagen.

Obesity is considered a chronic low-grade inflammatory status and the stromal vascular fraction (SVF) cells of adipose tissue (AT) are considered a source of inflammation-related molecules. We identified YKL-40 as a major protein secreted from SVF cells in human visceral AT. YKL-40 expression levels in SVF cells from visceral AT were higher than in those from subcutaneous AT. Immunofluorescence staining revealed that YKL-40 was exclusively expressed in macrophages among SVF cells. YKL-40 purified from SVF cells inhibited the degradation of type I collagen, a major extracellular matrix of AT, by matrix metalloproteinase (MMP)-1 and increased rate of fibril formation of type I collagen. The expression of MMP-1 in preadipocytes and macrophages was enhanced by interaction between these cells. These results suggest that macrophage/preadipocyte interaction enhances degradation of type I collagen in AT, meanwhile, YKL-40 secreted from macrophages infiltrating into AT inhibits the type I collagen degradation.

Biochemical and Biophysical Research Communications


Neonatal Exposure to Loe-Dose 2.3.7.8-Tetrachlorodibenzo-p-Dioxin Causes Autoimmunity Due to the Disruption of TCell Tolerance1

Although 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) has been shown to influence immune responses, the effects of low-dose TCDD on the development of autoimmunity are unclear. In this study, using NFS/sld mice as a model for human Sjögren's syndrome, in which the lesions are induced by the thymectomy on day 3 after birth, the autoimmune lesions in the salivary glands, and in later phase, inflammatory cell infiltrations in the other organs were developed by neonatal exposure to nonapoptotic dosage of TCDD without thymectomy on day 3 after birth. We found disruption of thymic selection, but not thymic atrophy, in TCDD-administered mice. The endogenous expression of aryl hydrocarbon receptor in the neonatal thymus was significantly higher than that in the adult thymus, suggesting that the neonatal thymus may be much more sensitive to TCDD compared with the adult thymus. In addition, the production of T(H)1 cytokines such as IL-2 and IFN-gamma from splenic CD4(+) T cells and the autoantibodies relevant for Sjögren's syndrome in the sera from TCDD-exposed mice were significantly increased compared with those in control mice. These results suggest that TCDD/aryl hydrocarbon receptor signaling in the neonatal thymus plays an important role in the early thymic differentiation related to autoimmunity.


Role of Plasmacytoid Dendric Cells for Aberrant Class Expression in Exocrine Glands from Estrogen-Deficient Mice of healthy Background

Although it has been well documented that aberrant major histocompatibility complex class II molecules may contribute to the development of autoimmune disorders, the precise mechanisms responsible for their tissue-specific expression remain unknown. Here we show that estrogen deficiency induces aberrant class II major histocompatibility complex expression in exocrine glands via interactions between epithelial cells and plasmacytoid dendritic cells. Relatively modest but functionally significant expression levels of major histocompatibility complex class II and class II transactivator molecules were observed in the exocrine glands of ovariectomized (Ovx) C57BL/6 (B6) mice, but were not seen in the exocrine glands of control B6 mice. We observed that the salivary dendritic cells adjacent to the apoptotic epithelial cells positive for terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling, were activated in Ovx mice, but were not activated in control mice. We obtained evidence that the salivary gland cells express both interferon regulatory factor-1 and class II transactivator type IV molecules in Ovx mice. Salivary gland cells from Ovx mice were also capable of inducing the activation of antigen-specific T cells from OT-II transgenic mice. These findings indicate that estrogen deficiency initiates class II transactivator type IV mRNA expression in exocrine glands via interactions between epithelial cells and plasmacytoid dendritic cells, suggesting that plasmacytoid dendritic cells play a pivotal role in gender-based autoimmune disorders in postmenopausal women.


著しい骨吸収を伴う歯性上顎洞炎の1例

著しい骨吸収を伴う歯性上顎洞炎の1例


Expression of the retinoblastoma protein RbAp48 in exocrine glands leads to Sjögren's syndrome-like autoimmune exocrinopathy.

Although several autoimmune diseases are known to develop in postmenopausal women, the mechanisms by which estrogen deficiency influences autoimmunity remain unclear. Recently, we found that retinoblastoma-associated protein 48 (RbAp48) induces tissue-specific apoptosis in the exocrine glands depending on the level of estrogen deficiency. In this study, we report that transgenic (Tg) expression of RbAp48 resulted in the development of autoimmune exocrinopathy resembling Sjögren's syndrome. CD4(+) T cell-mediated autoimmune lesions were aggravated with age, in association with autoantibody productions. Surprisingly, we obtained evidence that salivary and lacrimal epithelial cells can produce interferon-gamma (IFN-gamma) in addition to interleukin-18, which activates IFN regulatory factor-1 and class II transactivator. Indeed, autoimmune lesions in Rag2(-/-) mice were induced by the adoptive transfer of lymph node T cells from RbAp48-Tg mice. These results indicate a novel immunocompetent role of epithelial cells that can produce IFN-gamma, resulting in loss of local tolerance before developing gender-based autoimmunity.


The cytokine RANKL produced by positively selected thymocytes fosters medullary thymic epithelial cells that express autoimmune regulator.

The thymic medulla provides a microenvironment where medullary thymic epithelial cells (mTECs) express autoimmune regulator and diverse tissue-restricted genes, contributing to launching self-tolerance. Positive selection is essential for thymic medulla formation via a previously unknown mechanism. Here we show that the cytokine RANK ligand (RANKL) was produced by positively selected thymocytes and regulated the cellularity of mTEC by interacting with RANK and osteoprotegerin. Forced expression of RANKL restored thymic medulla in mice lacking positive selection, whereas RANKL perturbation impaired medulla formation. These results indicate that RANKL produced by positively selected thymocytes is responsible for fostering thymic medulla formation, thereby establishing central tolerance.


Three Cases of Mikulicz's Disease as an IgG4-related Disease

We reported three cases of Mikuhcz's disease. Mikulicz's disease was diagnosed by the following criteria: 1) symmetrical enlargement of the lacrimal and salivary glands lasting at least 3 months', 2) the lacrimal and salivary glands were microscopically involved in the infiltration of inflammatory cells, 3) sarcoidosis and other lymphoproliferative diseases were excluded. Three patients with Mikulicz's disease were all characterized by elevated IgG4 concentration in the serum and prominent infiltration of IgG4-positive plasmacytes in the minor salivary glands. On the contrary, there were no findings indicating sicca syndrome or anti-SS-A and SS-B antibodies, which characterize Sjögren syndrome. It is suggested that Mikulicz's disease is an IgG4-related plasmacytec disease, with a pathogenesis differing from that of Sjögren syndrome.


Atelocollagen-mediated local and systemic applications of myostatin-targeting siRNA increase skeletal muscle mass.

RNA interference (RNAi) offers a novel therapeutic strategy based on the highly specific and efficient silencing of a target gene. Since it relies on small interfering RNAs (siRNAs), a major issue is the delivery of therapeutically active siRNAs into the target tissue/target cells in vivo. For safety reasons, strategies based on vector delivery may be of only limited clinical use. The more desirable approach is to directly apply active siRNAs in vivo. Here, we report the effectiveness of in vivo siRNA delivery into skeletal muscles of normal or diseased mice through nanoparticle formation of chemically unmodified siRNAs with atelocollagen (ATCOL). ATCOL-mediated local application of siRNA targeting myostatin, a negative regulator of skeletal muscle growth, in mouse skeletal muscles or intravenously, caused a marked increase in the muscle mass within a few weeks after application. These results imply that ATCOL-mediated application of siRNAs is a powerful tool for future therapeutic use for diseases including muscular atrophy.


Development of Inflammatory Bowel Disease in Long-Evans Cinnamon Rats Based on CD4+CD25+Foxp3+ Regulatory T Cell Dysfunction

A mutant strain with defective thymic selection of the Long-Evans Cinnamon (LEC) rat was found to spontaneously develop inflammatory bowel disease (IBD)-like colitis. The secretion of Th1-type cytokines including IFN-gamma and IL-2 from T cells of mesenteric lymph node cells (MLNs) and lamina propria mononuclear cells, but not spleen cells, in LEC rats was significantly increased more than that of the control Long-Evans Agouti rats through up-regulated expression of T-bet and phosphorylation of STAT-1 leading to NF-kappaB activation. In addition, the number of CD4(+)CD25(+)Foxp3(+) regulatory T (Treg) cells of the thymus, MLNs, and lamina propria mononuclear cells from LEC rats was significantly reduced, comparing with that of the control rats. Moreover, bone marrow cell transfer from LEC rats into irradiated control rats revealed significantly reduced CD25(+)Foxp3(+) Treg cells in thymus, spleen, and MLNs compared with those from control rats. Indeed, adoptive transfer with T cells of MLNs, not spleen cells, from LEC rats into SCID mice resulted in the development of inflammatory lesions resembling the IBD-like lesions observed in LEC rats. These results indicate that the dysfunction of the regulatory system controlled by Treg cells may play a crucial role in the development of IBD-like lesions through up-regulated T-bet, STAT-1, and NF-kappaB activation of peripheral T cells in LEC rats.


Effective Treatment With Oral Administration of Rebamipide in a Model of Sjogren's Syndrome

To determine whether oral administration of rebamipide, a mucosal protective agent, is effective in the treatment of Sjögren's syndrome (SS) in the NFS/sld mouse model of the disease. NFS/sld mice were given daily oral doses of rebamipide (0.3 mg/kg of body weight or 3 mg/kg) or vehicle alone starting from the age of 4 weeks to the age of 8 weeks. The volume of saliva and tears was monitored during and after treatment. After the final dose, histologic features of the tissues, TUNEL+ apoptotic duct cells in affected glands, T cell and cytokine function, and levels of immunoglobulin isotypes and serum autoantibodies were examined. The 3-mg/kg dose of rebamipide prevented the development of autoimmune lesions. The average volume of saliva in rebamipide-treated mice was significantly higher than that in control mice. We found decreased TUNEL+ apoptotic duct cells in the salivary and lacrimal glands of rebamipide-treated mice as compared with control mice. Rebamipide treatment suppressed the activation of CD4+ T cells and Th1 cytokines (interleukin-2, interferon-gamma) associated with impaired NF-kappaB activity. Production of serum autoantibodies, IgM, and IgG1 was clearly inhibited. Our findings demonstrate the efficacy of oral administration of rebamipide in the treatment of SS. Rebamipide represents a new therapeutic strategy for the treatment of patients with sicca symptoms caused by SS, as well as for patients with other diseases.


Epitope mapping of anti-α-fodrin antibody in a case of early-onset multiple sclerosis


Possible involvement of stem cell factor and endothelin-1 in the emergence of pigmented squamous cell carcinoma in oral mucosa.

We present here the clinical, morphological and immunohistochemical features of a pigmented squamous cell carcinoma (SCC) in the oral mucosa of the hard palate of a 76-year-old Japanese man. He underwent a partial resection of the maxilla subsequent to radiotherapy. The tumor was typical, moderately well-differentiated SCC but had many melanocytes (melanocytosis) within it. Immunohistochemical analysis for stem cell factor (SCF) and endothelin-1, both of which are known to stimulate proliferation and differentiation of melanocytes, revealed prominent expression of both factors in the neoplastic squamous cells of the pigmented SCC, while the non-pigmented oral SCC showed little sign of either factor. These findings strongly suggest that SCF and endothelin-1 secreted by neoplasmic squamous cells are involved in the emergence of a rare variant of oral SCC.


Visualizing the dynamics of p21 (Wafl/Cip1)cyclin-dependent kinase inhibitor expression in living animals.

Although the role of p21(Waf1/Cip1) gene expression is well documented in various cell culture studies, its in vivo roles are poorly understood. To gain further insight into the role of p21(Waf1/Cip1) gene expression in vivo, we attempted to visualize the dynamics of p21(Waf1/Cip1) gene expression in living animals. In this study, we established a transgenic mice line (p21-p-luc) expressing the firefly luciferase under the control of the p21(Waf1/Cip1) gene promoter. In conjunction with a noninvasive bioluminescent imaging technique, p21-p-luc mice enabled us to monitor the endogenous p21(Waf1/Cip1) gene expression in vivo. By monitoring and quantifying the p21(Waf1/Cip1) gene expression repeatedly in the same mouse throughout its entire lifespan, we were able to unveil the dynamics of p21(Waf1/Cip1) gene expression in the aging process. We also applied this system to chemically induced skin carcinogenesis and found that the levels of p21(Waf1/Cip1) gene expression rise dramatically in benign skin papillomas, suggesting that p21(Waf1/Cip1) plays a preventative role(s) in skin tumor formation. Surprisingly, moreover, we found that the level of p21(Waf1/Cip1) expression strikingly increased in the hair bulb and oscillated with a 3-week period correlating with hair follicle cycle progression. Notably, this was accompanied by the expression of p63 but not p53. This approach, together with the analysis of p21(Waf1/Cip1) knockout mice, has uncovered a novel role for the p21(Waf1/Cip1) gene in hair development. These data illustrate the unique utility of bioluminescence imaging in advancing our understanding of the timing and, hence, likely roles of specific gene expression in higher eukaryotes.

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


Crosstalk between RANKL and Fas signaling in dendritic cells controls immune tolerance

Although receptor activator of nuclear factor (NF)-kappaB ligand (RANKL) signaling has been shown to prolong the survival of mature dendritic cells (DCs), the association of RANKL pathway with Fas-mediated apoptosis is obscure. Here, we found that bone marrow-derived DCs (BMDCs) from the Fas-deficient strain MRL/lpr mice, could survive much longer than normal DCs. The expressions of Bcl-x and Bcl-2 and the nuclear transport of NF-kappaB of RANKL-stimulated BMDCs from MRL/lpr mice were significantly up-regulated. By contrast, Fas expression of BMDCs from normal C57BL/6 and MRL(+/+) mice was increased by RANKL stimulation, and an enhanced DC apoptosis was found when stimulated with both RANKL and anti-Fas mAb, which was associated with activation of caspase-3 and caspase-9. Furthermore, the expression of FLIP(L), an inhibitory molecule against Fas-mediated apoptosis, in normal DCs was significantly decreased by RANKL and anti-Fas mAb. Indeed, the adoptive transfer of RANKL-stimulated DCs resulted in rapid acceleration of autoimmunity in MRL/lpr recipients. These findings indicate that the crosstalk between RANKL and Fas signaling in DCs might control immune tolerance.


Regulation of naive T cell function by the NF-κB2 pathway

T cell activation involves the orchestration of several signaling pathways, including that of the 'classical' transcription factor NF-kappaB components NF-kappaB1-RelA. The function of the 'nonclassical' NF-kappaB2-RelB pathway is less clear, although T cells lacking components of this pathway have activation defects. Here we show that mice deficient in NF-kappaB-inducing kinase have a complex phenotype consisting of immunosuppression mediated by CD25(-)Foxp3(-) memory CD4(+) cells and, in the absence of those cells, hyper-responsive naive CD4(+) T cells, which caused autoimmune lesions after adoptive transfer into hosts deficient in recombination-activating genes. Biochemical studies indicated involvement of a cell-intrinsic mechanism in which NF-kappaB2 (p100) limits nuclear translocation of NF-kappaB1-RelA and thereby functions as a regulatory 'brake' for the activation of naive T cells.


A novel apoptosis cascade mediated by lysosomal lactoferrin and its participation in hepatocyte apoptosis induced by D-galactosamine.

A new apoptosis cascade mediated by lysosomal lactoferrin was found in apoptotic liver induced by d-galactosamine. Caspase-3 and lactoferrin were increased in the apoptotic liver cytoplasm and serum transaminases were elevated. Recombinant lactoferrin stimulated procaspase-3 processing at 10(-6)-10(-7)M to an extent similar to that by granzyme B in vitro. Lactoferrin changed procaspase-3 structure susceptible to the processing. Synthetic peptide Y(679)-K(695) in lactoferrin molecule inhibited the processing of procaspase-3 by lactoferrin. Lactoferrin in lysosomes was decreased and lactoferrin released into cytoplasm was increased quantitatively in d-galactosamine induced apoptotic liver, and procaspase-3 in cytoplasm was processed to caspase-3.


Cepharanthin,a biscoclaurine alkaloid,prevents destruction of acinar tissues in murine Sjogren's syndrome.

Our previous study suggested that suppression by cepharanthin of tumor necrosis factor-a (TNF-a)-induced matrix metalloproteinase-9 (MMP-9) could prevent destruction of the acinar structure in the salivary glands of patients with Sjögren's syndrome (SS). In this study, we observed that in vivo administration of cepharanthin prevented severe damage to acinar tissues in the murine model of human SS. Cepharanthin was intraperitoneally administered to thymectomized female NFS/sld mice. Inflammatory lesions in the salivary and lacrimal glands were then examined histologically. Expression of phosphorylated IkB-a, MMP-9, and type IV collagen was analyzed immunohistochemically. The apoptotic cell death of acinar cells was determined. Although extensive mononuclear cell infiltration and destruction of acinar tissue in salivary and lacrimal glands were observed in control mice, significant improvement of these lesions was evident in mice treated with cepharanthin. Immunohistochemical analysis revealed that p65, phosphorylated IkB-a, and MMP-9 were more strongly stained in the acinar cells of control mice than in cepharanthin-treated mice. Although no staining for type IV collagen was observed in the acinar tissues of control mice, continuity of staining for type IV collagen was observed in acinar tissues of cepharanthin-treated mice. Destruction of acinar tissues was attributed to the induction of apoptosis, suggesting that cepharanthin inhibits apoptosis by suppressing phosphorylation of IkB-a, followed by prevention of MMP-9 activation. Our findings suggest that cepharanthin may be a promising agent for use in preventing destruction of acinar tissues in murine SS.


Ubiqitin Ligase Cbl-b Downregulates Bone Formation Through Suppression of IGF-I Signaling in Osteoblasts During Denervation

Unloading can prevent bone formation by osteoblasts. To study this mechanism, we focused on a ubiquitin ligase, Cbl-b, which was highly expressed in osteoblastic cells during denervation. Our results suggest that Cbl-b may mediate denervation-induced osteopenia by inhibiting IGF-I signaling in osteoblasts. Unloading, such as denervation (sciatic neurectomy) and spaceflight, suppresses bone formation by osteoblasts, leading to osteopenia. The resistance of osteoblasts to growth factors contributes to such unloading-mediated osteopenia. However, a detailed mechanism of this resistance is unknown. We first found that a RING-type ubiquitin ligase, Cbl-b, was highly expressed in osteoblastic cells after sciatic neurectomy in mice. In this study, we reasoned that Cbl-b played an important role in the resistance of osteoblasts to IGF-I. Cbl-b-deficient (Cbl-b(-/-)) or wildtype (Cbl-b(+/+)) mice were subjected to sciatic neurectomy. Bone formation in these mice was assessed by calcein labeling and histomorphometric analyses. We examined IGF-I signaling molecules in femora of these mice by Western blot and immunohistochemical analyses. We also examined the mitogenic response of Cbl-b-overexpressing or -deficient osteoblastic cells to various growth factors. In Cbl-b(+/+) mice, denervation decreased femur mass and bone formation, whereas it increased the expression of Cbl-b protein in osteoprogenitor cells and in osteocalcin-positive cells (osteoblastic cells) in hindlimb bone. In contrast, in Cbl-b(-/-) mice, bone mass and bone formation were sustained during denervation. Denervation inhibited the mitogenic response of osteoprogenitor cells most significantly to IGF-I. Therefore, we focused on Cbl-b-mediated modification of IGF-I signaling. Denervation decreased the amounts of insulin receptor substrate-1 (IRS-1), phosphatidly inositol 3-phosphate kinase (PI3K), and Akt-1 proteins in femora of Cbl-b(+/+) mice, whereas the amounts of these IGF-I signaling molecules in femora of Cbl-b(-/-) mice were constant after denervation. On a cellular level, primary osteoblastic cells from Cbl-b(-/-) mice were more stimulated to proliferate by IGF-I treatment compared with those from Cbl-b(+/+) mice. Furthermore, overexpression of Cbl-b increased ubiquitination and degradation of IRS-1 in primary Cbl-b(-/-) osteoblastic cells, leading to their impaired mitogenic response to IGF-I. These results suggest that Cbl-b induces resistance of osteoblasts to IGF-I during denervation by increasing IRS-1 degradation and that Cbl-b-mediated modification of IGF-I signaling may contribute to decreased bone formation during denervation.


Novel role for RbAp48 in tissue-specific,estrogen deficiency-dependent apoptosis in the exocrine glands.

Although tissue-specific apoptosis in the exocrine glands in estrogen-deficient mice may contribute to the development of autoimmune exocrinopathy, the molecular mechanism responsible for tissue-specific apoptosis remains obscure. Here we show that RbAp48 overexpression induces p53-mediated apoptosis in the exocrine glands caused by estrogen deficiency. RbAp48-inducible transfectant results in rapid apoptosis with p53 phosphorylation (Ser9) and alpha-fodrin cleavage. Reducing the expression of RbAp48 through small interfering RNA inhibits the apoptosis. Prominent RbAp48 expression with apoptosis was observed in the exocrine glands of C57BL/6 ovariectomized (OVX) mice but not in OVX estrogen receptor alpha(-/-), p53(-/-), and E2F-1(-/-) mice. Indeed, transgenic expression of the RbAp48 gene induced apoptosis in the exocrine glands but not in other organs. These findings indicate that estrogen deficiency initiates p53-mediated apoptosis in the exocrine gland cells through RbAp48 overexpression and exerts a possible gender-based risk of autoimmune exocrinopathy in postmenopausal women.


Crucial Roles of NF-kB for T Cell Activation


Catechin derivatives:specific inhibitor for caspases-3,7and 2,and the prevention of apoptosis at the cell and animal levels.

Tea-catechin derivatives are shown to inhibit activities of caspases-3, 2 and 7 in vitro, and prevented experimental apoptosis at the cell and animal levels. Epigallo-catechin-gallate showed the strongest inhibition at 1 x 10(-7)M to these caspases, but cysteine cathepsins and caspase-8 were not inhibited. Caspase-3 inhibition showed a 2nd-order allosteric-type, but the inhibition of caspases-2 and 7 showed a non-competitive-type. The apoptosis-test using cultured HeLa cells was inhibited by these catechins. In rat hepatocytes, apoptosis was induced by d-galactosamine in vivo. In this case, caspase-3 activity in the cytoplasm, the serum aminotransferases and dUTP nick formation detected by TUNNEL-staining were effects, and these elevations were suppressed by administration of catechin.


CCR7-Dependent Cortex-to-Medulla Migration of Positively Selected Thymocytes Is Essential for Establishing Central Tolerance

Immature CD4+CD8+ thymocytes, which are generated in the thymic cortex, are induced upon positive selection to differentiate into mature T lymphocytes and relocate to the thymic medulla. It was recently shown that a chemokine signal via CCR7 is essential for the cortex-to-medulla migration of positively selected thymocytes in the thymus. However, the role of the cortex-to-medulla migration in T cell development and selection has remained unclear. The present study shows that the developmental kinetics and the thymic export of mature thymocytes were undisturbed in adult mice lacking CCR7 or its ligands (CCR7L). The inhibition of sphingosine-1-phosphate-mediated lymphocyte egress from the thymus led to the accumulation of mature thymocytes in the cortex of CCR7- or CCR7L-deficient mice, unlike the accumulation in the medulla of normal mice, thereby suggesting that mature thymocytes may be exported directly from the cortex in the absence of CCR7 signals. However, the thymocytes that were generated in the absence of CCR7 or CCR7L were potent in causing autoimmune dacryoadenitis and sialadenitis in mice and were thus incapable of establishing central tolerance to organ-specific antigens. These results indicate that CCR7-mediated cortex-to-medulla migration of thymocytes is essential for establishing central tolerance rather than for supporting the maturation or export of thymocytes.


Biological and oncogenic properties of p53-deficient salivary gland epithelial cells with particular emphasis on stromal-epithelial interactions in tumorigenesis.

To understand the salivary gland pathobiology, we established an immortalized duct/basal cell line (MSE) from the submandibular glands of p53-deficient mice. A variety of culture assays and xenograft experiments were conducted. Cellular characteristics were analyzed using histological, immunohistochemical, ultrastructural, and molecular techniques. Inoculation of a mixture of MSE and Matrigel reconstructed polarized ducts whereas cotransplantation of MSE with both Matrigel and NIH3T3 (3T3) cells developed mixed tumors of adenoma and sarcoma. A daughter adenoma line (MSA) showed some transformed phenotype in vitro, but was marginally tumorigenic in vivo. Notably, pleomorphic adenoma gene 1 (PLAG1) was expressed in MSA but not in MSE. As compared with MSE, MSA showed higher levels of insulin-like growth factor-I receptor (IGF-IR). Interestingly, 3T3 sarcoma secreted insulin-like growth factor-II (IGF-II), while MSA did not. The intrinsic tumorigenic programs of p53 null salivary epithelium are promoted by 3T3 sarcoma-derived IGF-IIin a paracrine manner through overexpression of PLAG1 and IGF-IR.


Analysis of in vivo role of alpha-fodrin autoantigen in primary Sjogren's syndrome

The alpha-fodrin N-terminal portion (AFN) autoantigen mediates in vivo immunoregulation of autoimmune responses in primary Sjögren's syndrome (SS). We further examined this process and found that cleavage products of AFN were frequently detected in the salivary gland duct cells of SS patients. In in vitro studies using human salivary gland HSY cells, anti-Fas-induced apoptosis resulted in specific cleavage of alpha-fodrin into the 120-kd fragment, in association of alpha-fodrin with mu-calpain, and activation of caspase 3. Significant proliferative responses against AlphaFN autoantigen were observed in the peripheral blood mononuclear cells (PBMCs) from SS patients with higher pathological score (grade 4) and with short duration from onset (within 5 years). In vivo roles of AFN peptides were investigated using PBMCs from patients with SS, systemic lupus erythematosus, and rheumatoid arthritis. Significant proliferative T-cell responses of PBMCs to AFN peptide were detected in SS but not in systemic lupus erythematosus or rheumatoid arthritis. AFN peptide induced Th1-immune responses and accelerated down-regulation of Fas-mediated T-cell apoptosis in SS. Our data further elucidate the in vivo role of AFN autoantigen on the development of SS and suggest that the AFN autoantigen is a novel participant in peripheral tolerance.


Development of autoimmunity against transcriptionally unrepressed target antigen in the thymus of Aire-deficient mice

Autoimmune regulator (AIRE) gene mutation is responsible for the development of organ-specific autoimmune disease with monogenic autosomal recessive inheritance. Although Aire has been considered to regulate the elimination of autoreactive T cells through transcriptional control of tissue-specific Ags in thymic epithelial cells, other mechanisms of AIRE-dependent tolerance remain to be investigated. We have established Aire-deficient mice and examined the mechanisms underlying the breakdown of self-tolerance. The production and/or function of immunoregulatory T cells were retained in the Aire-deficient mice. The mice developed Sjogren's syndrome-like pathologic changes in the exocrine organs, and this was associated with autoimmunity against a ubiquitous protein, alpha-fodrin. Remarkably, transcriptional expression of alpha-fodrin was retained in the Aire-deficient thymus. These results suggest that Aire regulates the survival of autoreactive T cells beyond transcriptional control of self-protein expression in the thymus, at least against this ubiquitous protein. Rather, Aire may regulate the processing and/or presentation of self-proteins so that the maturing T cells can recognize the self-Ags in a form capable of efficiently triggering autoreactive T cells. With the use of inbred Aire-deficient mouse strains, we also demonstrate the presence of some additional factor(s) that determine the target-organ specificity of the autoimmune disease caused by Aire deficiency.


Mutations in the gene encoding fibroblast growth factor 10 are associated with aplasia of lacrimal and salivary glands

Autosomal dominant aplasia of lacrimal and salivary glands (ALSG; OMIM 180920 and OMIM 103420) is a rare condition characterized by irritable eyes and dryness of the mouth. We mapped ALSG to 5p13.2-5q13.1, which coincides with the gene fibroblast growth factor 10 (FGF10). In two extended pedigrees, we identified heterozygous mutations in FGF10 in all individuals with ALSG. Fgf10(+/-) mice have a phenotype similar to ALSG, providing a model for this disorder. We suggest that haploinsufficiency for FGF10 during a crucial stage of development results in ALSG.


Development of Autoimmune Arthritis With Aging Via Bystander T Cell Activation in the Mouse Model of Sjogren's Syndrome

A wide spectrum of extraglandular manifestations may occur in patients with Sjogren's syndrome (SS), but the mechanisms responsible for in vivo progression are still obscure. We undertook this study to evaluate the age-related changes during the development of extraglandular autoimmune lesions, including arthritis, in the murine model of primary SS, and to evaluate the possible relationship between age-related disturbance of activation-induced cell death and the in vivo kinetics against autoantigens. A total of 126 NFS/sld mice were investigated at ages 2, 4, 6, 10, 12, 18, 20, and 24 months. Cytokine production was tested using culture supernatants from anti-CD3 monoclonal antibody-stimulated T cells. Anti-single-stranded DNA (anti-ssDNA) antibodies, Ig isotypes (IgG1, IgG2a), rheumatoid factor (RF), and anti-type II collagen (anti-CII) antibodies were detected by enzyme-linked immunosorbent assay. Proliferative T cell responses against each of 3 recombinant alpha-fodrin proteins and against CII were analyzed. Autoimmune arthritis developed in SS model mice until age 24 months. Significant elevations in serum levels of RF, anti-ssDNA antibodies, and anti-CII antibodies were found in aging SS model mice. A high titer of serum autoantibodies against alpha-fodrin fragments (containing different epitopes that were originally identified in primary SS model mice) was frequently detected in young and aged SS model mice. Moreover, we found that alpha-fodrin autoantigen induced Th1 immune responses and accelerated disturbance of Fas-mediated T cell apoptosis in aged SS model mice. These results indicate that age-related disturbance of activation-induced cell death via bystander T cell activation may play a crucial role in the development of autoimmune arthritis in a murine model of SS.


Effective Treatment of a Mouse Model of Sjogren's Syndrome With Eyedrop Administrasiton of Anti-CD4 Monoclonal Antibody

To determine whether eyedrop administration of an anti-CD4 monoclonal antibody (mAb) is effective in the treatment of Sjögren's syndrome (SS) using a mouse model of the disease. The anti-CD4 mAb was administered daily into the eyes of mice with SS from ages 4 to 8 weeks or ages 10 to 12 weeks. During treatment, tear volume was monitored and after final treatment, histologic features of the lacrimal and salivary glands, the phenotypes and function of T cells, and serum titers of anti-alpha-fodrin antibody were examined. Eyedrop administration of anti-CD4 mAb before the onset of SS prevented the autoimmune pathology seen in the lacrimal glands but not that in the salivary glands. Furthermore, eyedrop administration of anti-CD4 mAb after the development of SS inhibited mononuclear cell infiltration and the destruction of parenchyma only in the lacrimal glands. Eyedrop administration of anti-CD4 mAb suppressed the local activation of CD4+ T cells rather than deleting CD4+ T cells, which reduced the expansion of pathologic CD4+ T cells against alpha-fodrin. These results demonstrate the remarkable efficacy of anti-CD4 mAb eyedrops in the treatment of SS eye symptoms, which illustrates a new antibody-based therapeutic strategy for patients with eye problems caused by SS as well as other diseases.


Newapoptosis cascade mediated by lysosomal enzyme and its protection by epigallo-catechin gallate

We found a novel procaspase-3 activating cascade mediated by lysosomal enzyme. The activating enzyme of procaspase-3, named lysoapoptase having the molecular weight of 78kDa was determined to be a lactoferrin located in the lysosome. Recombinant lactoferrin accelerated the processing of procaspase-3 to form active caspase-3 in vitro. D-Galactosamine is a well-known inducer of hepatocyte apoptosis. The caspase-3 which plays a common central role in the final step of various apoptosis cascades, was dramatically increased in the cytoplasm by the d-galactosamine administration in vivo. When D-galactosamine was administrated as a death signal in vivo, the lysosomal lactoferrin was released into the cytoplasm and procaspase-3 located in the cytoplasm was processed to form active caspase-3. The cotreatment of epigallo-catechin gallate resulted in the complete protection of the hepatocyte apoptosis suppressing the increases of caspase-3 in the cytoplasm. The caspase-3 activity was also inhibited directly by the epigallo-catechin gallate. Therefore, all apoptosis cascades mediated by caspase-3 should be suppressed by epigallo-catechin gallate. The caspase-3 activity was not only directly inhibited by epigallo-catechin gallate in vitro, but the release of lactoferrin from the lysosomes into the cytoplasm was also suppressed by epigallo-catechin gallate treatment in vivo. Therefore, the apoptosis induction was suppressed at the two successive steps by cotreatment of epigallo-catechin gallate in vivo.


Molecular Analysis of the Human Autoantibody Response to α-Fodrin in Sjogren Syndrome Reveals Novel Apoptosis-Induced Specificity

Lymphocyte infiltration of salivary and lacrimal glands leading to diminished secretion and gland destruction as a result of apoptosis is thought to be pivotal in the pathogenesis of Sjögren's syndrome (SS). The cytoskeletal protein alpha-fodrin is cleaved during this apoptotic process, and a strong antibody (Ab) response is elicited to a 120-kd fragment of cleaved alpha-fodrin in the majority of SS patients, but generally not in other diseases in which apoptosis also occurs. Little is known about the anti-alpha-fodrin autoantibody response on a molecular level. To address this issue, IgG phage display libraries were generated from the bone marrow of two SS donors and a panel of anti-alpha-fodrin IgGs was isolated by selection on alpha-fodrin immunoblots. All of the human monoclonal Abs (hmAbs) reacted with a 150-kd fragment and not with the 120-kd fragment or intact alpha-fodrin, indicating that the epitope recognized became exposed after alpha-fodrin cleavage. Analysis of a large panel of SS patients (defined by the strict San Diego diagnostic criteria) showed that 25% of SS sera exhibited this 150-kd alpha-fodrin specificity. The hmAbs stained human cultured salivary acinar cells and the staining was redistributed to surface blebs during apoptosis. They also stained inflamed acinar/ductal epithelial cells in SS salivary tissue biopsies, and only partially co-localized with monoclonal Abs recognizing the full-length alpha-fodrin. Our study shows that in SS patients, neoepitopes on the 150-kd cleaved product of alpha-fodrin become exposed to the immune system, frequently eliciting anti-150-kd alpha-fodrin Abs in addition to the previously reported anti-120-kd Abs. The anti-150-kd alpha-fodrin hmAbs may serve as valuable reagents for the study of SS pathogenesis and diagnostic analyses of SS salivary gland tissue.


Estrogen deficiency accelerates murine autoimmune arthritis associated with receptor activator of nuclear factor-kappaB ligand-mediated osteoclastogenesis

The aims of this study were to evaluate the in vivo effects of estrogen deficiency in MRL/lpr mice as a model for rheumatoid arthritis and to analyze the possible relationship between immune dysregulation and receptor activator of nuclear factor-kappaB ligand (RANKL)-mediated osteoclastogenesis. Experimental studies were performed in ovariectomized (Ovx)-MRL/lpr, Ovx-MRL+/+, sham-operated-MRL/lpr, and sham-operated-MRL+/+ mice. Severe autoimmune arthritis developed in younger Ovx-MRL/lpr mice until 24 wk of age, whereas these lesions were entirely recovered by pharmacological levels of estrogen administration. A significant elevation in serum rheumatoid factor, anti-double-stranded DNA, and anti-type II collagen was found in Ovx-MRL/lpr mice and recovered in mice that underwent estrogen administration. A high proportion of CD4(+) T cells bearing RANKL was found, and an enhanced expression of RANKL mRNA and an impaired osteoprotegerin mRNA was detected in the synovium. An increase in both osteoclast formation and bone resorption pits was found. These results indicate that estrogen deficiency may play a crucial role in acceleration of autoimmune arthritis associated with RANKL-mediated osteoclastogenesis in a murine model for rheumatoid arthritis.


Unique cell membrane expression if topoisomerase-ll alpha as a useful diagnostic marker of liposarcoma

Topoisomerase-II alpha (Topo-II alpha) is known as a cell cycle-related intranuclear marker. To the best of our knowledge, the expression of Topo-II alpha on extranuclear sites has not been reported. The aim of the present study was to determine the usefulness of Topo-II alpha immunostaining for detecting the lipoblasts that are essential to diagnosing liposarcoma. Surgical specimens, including benign lipomatous tumors (four cases), well-differentiated liposarcomas (three cases), myxoid liposarcomas (six cases), pleomorphic liposarcomas (two cases), dedifferentiated liposarcomas (two cases), myxoid malignant fibrous histiocytomas (six cases), and one case of mesenteric panniculitis, were studied. Samples were immunostained using antibodies for Topo-II alpha, S-100 protein and Ki-67. In addition, we used the western blot method to investigate immunohistochemical-affinity in adipocytes. Mature adipocytes and lipoblasts in all of the benign and malignant lipomatous tumors intensively expressed cell contours positivity for Topo-II alpha. Cytoplasm of the lipoblasts occasionally reacted to the antibody and highlighted intracytoplasmic small unilocular, multivacuolated, or bubble-like patterns. Western blot analysis confirmed a 70 kDa product reactive to Topo-II alpha in the cell membrane fragment of mature adipocytes. S-100 protein expressed adipocytes and lipoblasts, but the detection of lipoblasts was not as easy as in Topo-II alpha immunostaining. Immunoreactivity of Ki-67 was limited to the nuclei, and the nuclear labeling index of Ki-67 correlated with that of Topo-II alpha. The immunoreactivity of Topo-II alpha for lipoblasts was more sensitive and obvious than those of S-100 protein. Immunostaining using the antibody for Topo-II alpha seems to be useful in recognizing lipoblasts that have been overlooked in hematoxylin-eosin-stained preparations, and is a useful marker for diagnosing liposarcoma.


Critical Role of Cathepsin-Inhibitors for Autoantigen Processing and Autoimmunity


Two Cases of So-Called Kuttner Tumor of Submandibular Gland

顎下腺に発症した いわゆるKuttner腫瘍の2例


A Case of Quadruple Cancer Arising Synchronously in the Qpper Gingiva,Penis,and Kidney 2 Years After Colon Cancer Treatment

大腸癌治療2年後に同時性に上顎歯肉，陰茎および腎に癌を生じた4重複癌の1例

Japanese Journal of Oral & Maxillofacial Surgery


Development of Autoimmune Exocrinopathy Resembling Sjogren's Syndrome in Adoptively Transferred Mice With Autoreactive CD4+ T Cells

The pathologic mechanisms responsible for organ-specific tissue damage in primary Sjögren's syndrome (SS) remain unclear, but it has been suggested that the pathology is mediated by autoreactive CD4+ T cells infiltrating the salivary and lacrimal glands. This study was undertaken to investigate whether alpha-fodrin autoantigen-specific autoreactive CD4+ T cells are capable of inducing autoimmune lesions. A total of 45 synthetic alpha-fodrin peptides designed to be 20 amino acid residues in length were generated. To establish an autoreactive T cell line, limiting dilution analysis (LDA) was performed on lymph node cells (LNCs) in the presence of alpha-fodrin peptides. The effects of adoptive transfer of autoreactive CD4+ T cells into normal syngeneic recipients were investigated. Autoreactive CD4+ T cell lines that recognize synthetic alpha-fodrin peptide, which produced Th1 cytokines and showed cytotoxic activities, were established in a murine model for SS. T cell receptor V(beta) usage and third complementarity-determining region (CDR3) sequences indicated that in some cases V(beta)6-CDR3 genes matched between the tissue-infiltrating T cells and the autoreactive T cell lines. Adoptive transfer of the autoreactive CD4+ T cells into normal syngeneic recipients induced autoimmune lesions quite similar to those of SS. Our data help to elucidate the pathogenic mechanisms responsible for tissue destruction in autoimmune exocrinopathy and indicate that autoreactive CD4+ T cells play a pivotal role in the development of murine SS.


Anti-a-fodrin autoantibodies in Moyamoya disease

Moyamoya disease (MMD) is a rare entity that results in progressive occlusion of the arteries of the circle of Willis, but the pathogenesis of MMD is unknown. MMD sera (n=32) were tested for anti-endothelial cell antibodies by enzyme-linked immunoassays and flow cytometric analysis. Apoptosis was induced in human umbilical vein endothelial cells by tumor necrosis factor-alpha. We found that a high proportion of MMD sera had anti-endothelial cell antibodies with apoptotic stimuli. Prominent reactivities of MMD sera (72%) with recombinant human alpha-fodrin were observed. Our study demonstrates that MMD sera contain a high incidence of anti-alpha-fodrin autoantibodies, providing new insight into the mechanisms of occlusion of MMD arteries.


Development of autoimmune exocrinopathy resembling Sjogren's syndorome in estorogen deficient mice of healthy background

Although a number of autoimmune diseases are known to develop in postmenopausal women, the mechanisms by which estrogen deficiency influences autoimmune lesions remain unclear. We speculate that antiestrogenic actions might be a potent factor in the formation of pathogenic autoantigens. Previously, we have identified 120-kd alpha-fodrin as an important autoantigen in Sjögren's syndrome (SS). When healthy C57BL/6 (B6) mice were treated with an ovariectomy (Ovx), we found a significant increase in TUNEL(+)-apoptotic epithelial cells in the salivary gland cells associated with alpha-fodrin cleavage during 2 and 3 weeks after Ovx. By contrast, no apoptotic cells were found in estrogen receptor-alpha knockout mice. In in vitro studies using primary cultured mouse salivary gland cells and human salivary gland cells, we found a cleavage product of 120-kd alpha-fodrin in cells that had undergone tamoxifen (Tam)-induced apoptosis through caspase activation, especially caspase-1. Adoptive transfer of alpha-fodrin-reactive T cells into Ovx-B6 and -SCID mice resulted in the development of autoimmune exocrinopathy quite similar to SS. These results suggest that estrogen deficiency exerts a crucial influence on autoantigen cleavage, and may cause, in part, autoimmune exocrinopathy in postmenopausal women.


顎関節に発生した滑膜性軟骨腫症の1例

顎関節に発生した滑膜性軟骨腫症の1例

Although synovial chondromatosis occurs frequently near the ends of long bones, such as the knee, elbow, and hip joints, it rarely affects the temporomandibular joint.<BR>A 52-year-old woman visited our hospital because of swelling in the left side of the temporomandibular joint and trismus. On magnetic resonance imaging, the lesion was found to be chondroid tissue between the left mandibular fossa and the condylar head. Magnetic resonance imaging revealed a high signal mass measuring 35×40mm around the left condylar head. The clinical diagnosis was synovial chondromatosis. Synovectomy and removal of the mass were performed with the patient under general anesthesia. Histopathologically, the mass was formed by typical chondrocytes and was diagnosed to be synovial chondromatosis. The patient has been followed up for 1 year 4 months. There has been no reccurence of the mass or temporomandibular joint disorder.


Insights into the roles of cathepsins in antigen processing and presentation revealed by specific inhibitors

Eleven human cathepsins have been identified, however, the in vivo roles of individual cathepsins are still largely unknown. In this brief review we will summarize the functions of individual cathepsins in antigen processing and presentation, which are the initial steps of the immune response. Two general inhibitors of papain-like cysteine proteases, E-64 and pyridoxal phosphate, can completely suppress antigen presentation in vivo. To evaluate the contribution of individual cathepsins, specific inhibitors have been developed based on cathepsin tertiary structures: CA-074 for cathepsin B, CLIK-148 and -195 for cathepsin L, CLIK-60 for cathepsin S. Administration of CA-074, a cathepsin B inhibitor, suppresses the response to exogenous antigens, such as hepatitis B virus antigen, ovalbumin and Leishmania major antigen, and induces switching of the helper T cell responses from Th-2 to Th-1 of CD4+ T cells, thereby downregulating the production of IgE and IgG1. Administration of the cathepsin S inhibitor CLIK-60 impairs presentation of an autoantigen, alpha-fodrin, in Sjogren's syndrome and suppresses the Th-1 response and autoantibody production.


Activation of Epstein-Barr virus by saliva from Sjogren's syndrome patients

The aim of this study was to examine the mechanism of Epstein-Barr virus (EBV) activation by soluble factors from the inflamed salivary glands of patients with Sjogren's syndrome (SS). Saliva from SS patients was used to examine the regulation of EBV activation by an inflammatory salivary microenvironment. Transient transfection of the EBV-negative salivary gland cell line (HSY) with BZLF1, a trans-activating EBV gene promoter-fusion construct (Zp-luc), was used in this study. The results showed that under conditions where the BZLF1 promoter is activated by potent stimuli, SS saliva (from eight of 12 patients) exerts a significant effect on expression of the luciferase gene. A specific inhibitor of protein kinase C did not affect the SS saliva-induced Zp-luc activity, whereas treatment with inhibitors of calmodulin, calcineurin and IP3, dose-dependently decreased this induction. Transforming growth factor beta1 (TGF-beta1), which is known to be expressed in SS salivary glands, dose-dependently induced Zp-luc activity. Hence, these results demonstrate the activation of EBV by SS saliva and suggest that EBV activation at the inflammatory site may occur in the presence of TGF-beta1 via triggering of the mitogen-activated protein kinase (MAPK) kinase signalling pathway.


6歳児の下顎骨に発生した若年性(侵襲性)化骨性線維腫の1例

6歳児の下顎骨に発生した若年性(侵襲性)化骨性線維腫の1例

Pediatric Oral and Maxillofacial Surgery


Cathepsin S-inhibitor prevents autoantigen presentation and autoimmunity

The cysteine endoprotease cathepsin S mediates degradation of the MHC class II invariant chain Ii in human and mouse antigen-presenting cells. Studies described here examine the functional significance of cathepsin S inhibition on autoantigen presentation and organ-specific autoimmune diseases in a murine model for Sjögren syndrome. Specific inhibitor of cathepsin S (Clik60) in vitro markedly impaired presentation of an organ-specific autoantigen, 120-kDa alpha-fodrin, by interfering with MHC class II-peptide binding. Autoantigen-specific T cell responses were significantly and dose-dependently inhibited by incubation with Clik60, but not with inhibitor s of cathepsin B or L. Clik60 treatment of mouse salivary gland cells selectively inhibited autopeptide-bound class II molecules. Moreover, the treatment with Clik60 in vivo profoundly blocked lymphocytic infiltration into the salivary and lacrimal glands, abrogated a rise in serum autoantibody production, and led to recovery from autoimmune manifestations. Thus, inhibition of cathepsin S in vivo alters autoantigen presentation and development of organ-specific autoimmunity. These data identify selective inhibition of cysteine protease cathepsin S as a potential therapeutic strategy for autoimmune disease processes.


Overexpression of extracelular-signal regulated kinases on oral squamous cell carcinoma

Mitogen-activated protein kinases (MAPKs) consist of major three subfamilies, extracellular-signal regulated kinases (ERK MAPKs), the c-Jun N-terminal kinases/stress activated protein kinases (JNK MAPKs/SAP MAPKs), and p38 MAPKs. ERK MAPKs pathway is one of the most important pathways for cell proliferation. ERK MAPKs are located at downstream of a lot of growth factors (epidermal growth factor (EGF), nerve growth factor (NGF), platelet-derived growth factor (PDGF), etc.), the overexpressions and activation of which are frequently detected on a number of cancers including oral squamous cell carcinoma (OSCC). These data indicate that overexpression and activation of ERK MAPKs play an important role in cancer progression. On the contrary, JNK MAPKs are possible regulators of cell death induced by chemotherapeutic agents. p38 MAPKs are activated by pro-inflammatory cytokines and inflammatory drugs (non-steroidal anti-inflammatory drug), which are known to suppress cancer growth. These findings imply that each MAPKs can be molecular targets for cancer therapy in OSCC and its investigation is very important things in OSCC.


Suppression of TNF-α-induced MMP 9 production in human salivary gland acinar cells by cepharanthine occurs via down-regulation of NFκB --- A possible therapeutic agent for preventing the destruction of the acinar structure in the salivary glands of Sjögren's syndrome patients

Our previous results suggested that suppression of tumor necrosis factor alpha (TNFalpha)-induced matrix metalloproteinase 9 (MMP-9) could prevent the destruction of acinar tissue in the salivary glands of patients with Sjögren's syndrome (SS). The present study was undertaken to investigate the effect of cepharanthine on the suppression of TNFalpha-induced MMP-9 production in NS-SV-AC, an SV40-immortalized normal human acinar cell clone. After pretreatment with or without cepharanthine, NS-SV-AC cells were treated with TNFalpha alone or with a combination of TNFalpha and cepharanthine. The expression of MMP-9 was then examined at the protein and messenger RNA levels. In addition, the effect of cepharanthine on the morphogenetic behavior of NS-SV-AC cells cultured on type IV collagen-coated dishes in the presence of TNFalpha was examined. Although TNFalpha induced the production of MMP-9 in NS-SV-AC cells, this production was greatly suppressed when cells were pretreated with cepharanthine, followed by treatment with both TNFalpha and cepharanthine. In addition, cepharanthine suppressed the TNFalpha-stimulated NF-kappaB activity by partly preventing the degradation of IkappaBalpha protein in NS-SV-AC cells. When NS-SV-AC cells were seeded on type IV collagen-coated dishes in the presence of both TNFalpha and plasmin, type IV collagen interaction with the cells was lost and the cells entered apoptosis. However, pretreatment with cepharanthine restored the aberrant in vitro morphogenesis of the NS-SV-AC cells. These results may indicate a molecular mechanism by which cepharanthine is able to protect against the destruction of the acinar structure in salivary glands from patients with SS.


Prevention and induction of autoimmune exocrinopathy is dependent on pathogenic autoantigen cleavage in murine Sjogren's syndrome

The in vivo role of autoantigen cleavage during apoptosis in autoimmune diseases remains unclear. Previously, we found a cleavage product of 120-kDa alpha-fodrin as an important autoantigen in the pathogenesis of primary Sjögren's syndrome (SS). In the murine primary SS model, tissue-infiltrating CD4(+) T cells purified from the salivary glands bear a large proportion of Fas ligand, and the salivary gland duct cells constitutively possess Fas. Infiltrating CD4(+) T cells, but not CD8(+) T cells, identified significant (51)Cr release against mouse salivary gland cells. In vitro studies demonstrated that apoptotic mouse salivary gland cells result in a specific alpha-fodrin cleavage into 120 kDa and that preincubation with caspase inhibitor peptides blocked alpha-fodrin cleavage. In vivo treatment with caspase inhibitors N-benzyloxycarbonyl-Val-Ala-Asp fluoromethyl ketone and N-acetyl-Asp-Glu-Val-Asp-al-CHO into the murine model results in dramatic inhibitory effects on the development of autoimmune lesions and in restoration of sicca syndrome. Furthermore, we found that immunization with recombinant alpha-fodrin protein identical with an autoantigen into normal recipients induced autoimmune lesions similar to SS. These data indicate that prevention and induction of autoimmune exocrinopathy is dependent on autoantigen cleavage via caspase cascade and that caspase inhibitors might provide a new therapeutic option directed at reducing tissue damage in the murine model for SS.


Possible Role of Organ-Specific Autoantigen for Fas Ligand-Mediated Activation-Induced Cell Death in Murine Sjögren's Syndrome1

Activation-induced cell death (AICD) is a well-known mechanism of peripheral T cell tolerance that depends upon an interaction between Fas and Fas ligand (FasL). In this study, we demonstrate that the administration of a soluble form of anti-FasL Ab, FLIM58, results in severe destructive autoimmune exocrinopathy in the murine model of human Sjögren's syndrome (SS), and we found that an organ-specific autoantigen may play an important role on down-modulation of AICD. A high titer of serum autoantibodies against 120-kDa alpha-fodrin autoantigen was detected in the FLIM58-treated mice, and splenic T cell culture supernatants contained high levels of IFN-gamma. In vitro T cell apoptosis assay indicated that FasL-mediated AICD is down-regulated by autoantigen stimulation in spleen cells from the murine SS model, but not from Fas-deficient MRL/lpr mice and FasL-deficient MRL/gld mice. FasL undergo metalloproteinase-mediated proteolytic processing in their extracellular domains, resulting in the release of soluble trimeric ligands (soluble FasL). We showed that the processing of soluble FasL occurs in autoantigen-specific CD4(+) T cells, and that a significant increase in expressions of metalloproteinase-9 mRNA was observed in spleen cells from SS model mice. These findings indicate that the increased generation of soluble FasL inhibits the normal AICD process, leading to the proliferation of effector CD4(+) T cells in the murine SS model.


Possible Involvement of EBV-Mediated α-Fodrin Cleavage for Organ-Specific Autoantigen in Sjogren's Syndrome

A cleavage product of alpha-fodrin may be an important organ-specific autoantigen in the pathogenesis of Sjogren's syndrome (SS), but the mechanisms of alpha-fodrin cleavage remain unclear. Since EBV has been implicated in the pathogenesis of SS, we determined whether EBV activation could induce the SS-specific 120-kDa autoantigen alpha-fodrin. ZEBRA mRNA expression, a marker for activation of the lytic cycle of EBV, was found in the salivary gland tissues from SS patients, but not in those from control individuals. ZEBRA-expressing lymphoid cells were also found in the SS glands in double-stained immunohistochemistry. Furthermore, a significant link between production of Abs against 120-kDa alpha-fodrin and reactivated EBV Ag was found in sera from patients with SS, but not in those from control individuals. EBV-activated lymphoid cells showed specific alpha-fodrin cleavage to the expected 120-kDa fragments in vitro. Pretreatment with caspase inhibitors inhibited cleavage of alpha-fodrin. Thus, an increase in apoptotic protease activities induced by EBV reactivation may be involved in the progression of alpha-fodrin proteolysis in the development of SS.


Anti-alpha-fodrin antibodies in Sjogren's syndrome in children

To investigate the prevalence of anti-alpha-fodrin antibody specific for adult Sjögren's syndrome (SS) in patients with juvenile onset SS. Serum anti-alpha-fodrin antibody was examined in 15 patients with juvenile SS (11 cases of primary SS and 4 secondary SS) and in 16 children with systemic lupus erythematosus (SLE) by Western blot analysis using a recombinant 120 kDa alpha-fodrin fusion protein. All the 15 serum samples from patients with SS reacted with a recombinant alpha-fodrin fusion protein in Western blot analysis. In contrast, reactivity was found in only 2 of the 16 patients with SLE. The clinical features of the 15 patients with juvenile onset SS were very specific; only 4 patients complained of dryness, while 6 had abnormal excretion ability. Salivary gland enlargement was the most common clinical manifestation. Characteristic laboratory findings in juvenile onset SS included a higher prevalence of antinuclear antibodies, anti-SSA/Ro antibodies, and rheumatoid factor, as well as increased erythrocyte sedimentation rate and hypergammaglobulinemia. The pathogenesis of juvenile SS seems to be the same as that of adult SS, although subjective symptoms of dryness are less frequent in juvenile cases. This discrepancy may indicate that SS is a slowly progressive disease with a long time span. The anti-alpha-fodrin antibody is likely to be a reliable diagnostic marker for juvenile SS.


Anti-α-Fordrin Autoantibody Is an Early Diagnostic Marker for Childhood Primary Shogren Syndrome

alpha-fodrin is a recently identified autoantigen associated with adult primary Sjögren's syndrome (SS). We tested whether anti-alpha-fodrin antibody could also be used as a diagnostic marker for childhood SS. We performed immunoblot analysis of sera from 7 patients with childhood primary SS using glutathione-S-transferase alpha-fodrin fusion protein as an antigen. Anti-alpha-fodrin antibody was detected in sera from all 7 patients with childhood primary SS, 2 of 4 with secondary SS, and one of 7 with systemic lupus erythematosus, but in no other healthy controls. The anti-alpha-fodrin autoantibody was detected before anti-SSA or SSB antibody became positive; thus anti-alpha-fodrin antibody could be a useful marker for the early diagnosis of SS.


Improvement of Lacrimal Function by Topical Application of CyA in Murine Models of Sjögren's Syndrome

The object of this study was to evaluate improvement of lacrimal gland (LG) function after topical cyclosporin A (CyA). Topical CyA (0.01% and 0.1%) was applied to two mouse models of Sjögren's syndrome, the NFS/sld after thymectomy and the nonobese diabetic (NOD) mouse, and the functional integrity of the lacrimal gland was evaluated by measuring basal and stimulated tear secretion and its histologic integrity by examining it for apoptosis and lymphocyte invasion. After treatment with CyA at 0.1% in the NFS/sld mice, tear function increased, and there was a decrease in lymphocyte infiltration of the LG and a decrease in apoptotic figures among the acinar cells. In the NOD mice, tear function also improved, but there was no associated decrease in lymphocyte infiltration. However, the expression of Fas ligand (FasL) in NOD mice by infiltrating lymphocytes was suppressed with 0. 1% CyA eye drops. CyA appears to improve tear secretion in mouse models of Sjögren's syndrome by preventing lymphocyte-induced apoptosis of acinar cells. In one model this was achieved by preventing lymphocyte infiltration and in the other by reducing expression of FasL expression on infiltrating lymphocytes.

Investigative Ophthalmology & Visual Science


Mechanisms of neonatal tolerance induced in an animal model for primary Sjogren's syndrome by intravenous administration of autoantigen

Neonatal exposure to autoantigen is believed to induce effective antigen-specific T-cell tolerance in experimental models of autoimmunity. We have identified 120 kDa alpha-fodrin autoantigen in an animal model for primary Sjögren's syndrome (SS), that has been determined as a candidate autoantigen in both an animal model and the patients with primary SS. We demonstrate here that neonatal injection of autoantigen induce relevant tolerance when treated with intravenous (i.v.) administration within 24 h after birth, but not with i.v. injection after the thymectomy or with intraperitoneal injection. Autoantigen-specific T-cell response was significantly reduced in mice induced neonatal tolerance, and the activation markers of splenic CD4+ T cells were down-regulated in mice treated with neonatal administration. Because we detected that neonatal i.v. injection of autoantigen prevented Th1 response, it is possible that the autoantigen administration within 24 h after birth induce regulatory T cells that had a protective effect against Th1-mediated autoimmune diseases. These results indicate that the prevention of the spontaneous anti-120 kDa alpha-fodrin response in vivo, by tolerization of the autoantigen-reactive T cells, blocked the development of autoimmune lesions in an animal model for primary SS.


Expression and Function of X Chromosome-Linked Inhibitor of Apoptosis Protein in Sjogren's Syndrome

Apoptotic cell death in acinar and ductal epithelial cells is thought to play an important role in the development of salivary gland dysfunction in patients with Sjogren's syndrome (SS). We examined the expression of anti-apoptotic molecules in salivary glands from patients with SS. The labial salivary glands from six human T-cell leukemia virus (HTLV)-I-seronegative and eleven HTLV-I-seropositive SS patients were analyzed by immunohistochemistry. In vitro experiments were performed with a human salivary gland cell line (HSG cells). Immunohistologic analyses revealed that Bcl-2 and Bcl-x were preferentially expressed in salivary infiltrating mononuclear cells more than acinar and ductal epithelial cells. In contrast, strong X chromosome-linked inhibitor of apoptosis protein (XIAP) expression was evident in both acinar and ductal epithelial cells. The pattern of expression of these anti-apoptotic molecules was similar in both HTLV-I-seropositive and HTLV-I -seronegative SS patients. Western blot analysis confirmed expression of XIAP in cultured HSG cells. The expression of XIAP in HSG cells was increased by IL-1beta, TGF-beta1, or IL-10. However, XIAP expression was down-regulated by TNF-alpha, which induced apoptotic cell death of HSG cells with an increase in caspase-3 activity. These effects of TNF-alpha in HSG cells were antagonized by IL-1beta, TGF-beta1, or IL-10. Our results suggest that XIAP is important in regulating apoptotic cell death of acinar and ductal epithelial cells in patients with SS.

Laboratory Investigation; a Journal of Technical Methods and Pathology


Autoantigen-specific CD4+CD28low T cell subset prevents autoimmune exocrinopathy in murine Sjogren's syndrome

Organ-specific autoimmune exocrinopathy resembling Sjögren's syndrome (SS) that spontaneously develops in NFS/sld mutant mice thymectomized 3 day after birth is dependent on Th1-type CD4+ T cells. We previously reported that a cleavage product of 120-kDa alpha-fodrin may be an important autoantigen in the pathogenesis of SS in both an animal model and the patients. We demonstrate that in an animal model of SS with overt exocrinopathy, a unique CD4+ T cell subset expressing CD28low is dramatically increased in spleen cells before the disease onset, but that the CD4+ T cells of diseased mice were virtually all CD28high. We found that the spleen cells in these mice before the disease onset showed a significant increase in autoantigen-specific T cell proliferation. Analysis of in vitro cytokine production by spleen cells indicated, before the disease onset, severely impaired production of IL-2 and IFN-gamma in the animal model, whereas high levels of IL-4 were observed. Expression of cytokine genes, including IL-4, IL-10, and TGF-beta, was detected in FACS-sorted CD4+CD28low T cells by RT-PCR analysis. Transfer of CD4+CD28low T cells into the animal model actually prevented the development of autoimmune lesions including autoantibody production. These results suggest that a CD4+CD28low T cell subset that is continuously activated by an organ-specific autoantigen may play a regulatory role in the development of organ-specific autoimmune disease in an animal model of SS.


Suppression of tumor necrosis factor-a-induced matrix metalloproteinase-9-production by introduction of a super-repressor form of IkB-cDNA into immotalized human salivary gland acinar cells

We have previously shown that specific enhancement in acinar cells of proteolytic activity induced by tumor necrosis factor alpha (TNFalpha) may be responsible for the destruction of the acinar structure in the salivary glands of patients with Sjögren's syndrome. Because matrix metalloproteinase 9 (MMP-9) is regulated by nuclear factor kappaB (NF-kappaB), we investigated the effect of a super-repressor form of inhibitor of nuclear factor kappaBalpha (srIkappaBalpha) on the suppression of TNFalpha-induced MMP-9 production in acinar cells. Two srIkappaBalpha complementary DNA (cDNA)-transfected acinar cell clones (ACMT-6 and ACMT-7) and 1 empty vector-transfected cell clone (ACpRc-1) were established. After treatment of cell clones with TNFalpha, the expression of MMP-9 was examined. In addition, the effect of TNFalpha on cell growth and the morphogenetic behavior of cell clones cultured on type IV collagen-coated dishes were examined. TNFalpha induced the production of MMP-9 in the ACpRc-1 cell clone, but greatly suppressed MMP-9 production in ACMT-6 and ACMT-7 clones. No apparent cytotoxic effect of TNFalpha treatment was observed in these cell clones. When ACpRc-1 cells were seeded on type IV collagen-coated dishes in the presence of both TNFalpha and plasmin, type IV collagen interaction with the cells was lost and the cells entered apoptosis. However, even when ACMT-6 and ACMT-7 cells were cultured under the same culture conditions as those for ACpRc-1, these cell clones attached to the substrate and grew consistently without showing apoptosis. Conclusion. These observations indicate that suppression of TNFalpha-induced MMP-9 production by the introduction of srIkappaBalpha cDNA corrected the aberrant in vitro morphogenesis of acinar cells grown on type IV collagen.


5-Fluorouracil Induces Apoptosis through the Suppression of NF-κB Activity in Human Salivary Gland Cancer Cells

Activation of the transcription factor NF-kappaB results in protection against apoptosis, and the chemotherapeutic agent 5-Fluorouracil (5-FU) exerts its cytotoxic effect through the induction of apoptosis. Thus, we examined whether 5-FU could induce apoptosis through the suppression of NF-kappaB activity. We found that upon treatment of a human salivary gland cancer cell line (cl-1) with 5-FU, the NF-kappaB activity was suppressed in a time-dependent manner. This inhibition was mediated by a prevention of the degradation of the inhibitory IkappaB-alpha protein. In addition, the expression of TRAF-2 and cIAP-1, which are transcriptionally regulated by NF-kappaB and function as anti-apoptotic molecules through the interruption of caspase pathway, was also inhibited by 5-FU. Finally, the activity of caspase-8 and caspase-3 showed a significant increase in response to 5-FU. By flow cytometric analysis, 5-FU did not affect the expression level of Fas on the cell surface. Thus, our results suggest that one of the molecular mechanisms involved in 5-FU-induced apoptosis in cl-1 cells may be due to the suppression of NF-kappaB activity, resulting in the activation of the pro-apoptotic pathway.

Biochemical and Biophysical Research Communications


The Rate of Cell Growth Is Regulated by Purine Biosynthesis via ATP Production and G to Sphase Transition

We recently showed that an increased supply of purine nucleotides increased the growth rate of cultured fibroblasts. To understand the mechanism of the growth rate regulation, CHO K1 (a wild type of Chinese hamster ovary fibroblast cell line) and CHO ade (-)A (a cell line deficient in amidophosphoribosyltransferase, a rate-limiting enzyme of the de novo pathway) were cultured under various conditions. Moreover, a defective de novo pathway in CHO ade (-)A cells was exogenously restored by 5-amino-4-imidazole-carboxamide riboside, a precursor of the de novo pathway. The following parameters were determined: the growth rate of CHO fibroblasts, the metabolic rate of the de novo pathway, the enzyme activities of amidophosphoribosyltransferase and hypoxanthine phosphoribosyltransferase, the content of intracellular nucleotides, and the duration of each cell-cycle phase. We concluded the following: (i) Purine de novo synthesis, rather than purine salvage synthesis or pyrimidine synthesis, limits the growth rate. (ii) Purine nucleotides are synthesized preferentially by the salvage pathway as long as hypoxanthine is available for energy conservation. (iii) The GTP content depends on the intracellular ATP content. (iv) Biosynthesis of purine nucleotides increases the growth rate mainly through ATP production and promotion of the G(1)/S transition.


Severe destructive autoimmune lesions with aging in murine Sjogren's syndrome through Fas-mediated apoptosis

When we evaluated the age-associated changes in autoimmune exocrinopathy in a NFS/sld murine model for primary Sjögren's syndrome (SS), severe destructive autoimmune lesions developed in the salivary and lacrimal glands in the aged mice, compared with those observed in the younger model. We detected a decreased secretion of saliva and tear flow in the aged group. A significant increase of TUNEL(+)-apoptotic epithelial duct cells in the salivary glands was detected in the aged SS animal model. A higher proportion of mouse salivary gland cells bearing Fas was found in the aged group, whereas no significant changes were seen on tissue-infiltrating CD4(+) T cells bearing FasL in the salivary glands from young and aged mice. We detected an increased cleavage product of organ-specific autoantigen, 120-kd alpha-fodrin, in the aged salivary gland tissues on immunoblotting, and an increase in serum autoantibody production against 120-kd alpha-fodrin by enzyme-linked immunosorbent assay. An increase in the proliferative response of splenic T cells against organ-specific autoantigen was observed, whereas nonspecific concanavalin A responsiveness was decreased in the aged mice. In addition, a decrease in Fas expression was found on splenic CD4(+) T cells in the aged mice, and anti-Fas mAb-stimulated apoptosis was down-regulated on CD4(+) T cells. These results indicate that age-associated dysregulation of CD4(+) T cells may play a crucial role on acceleration of organ-specific autoimmune lesions in a murine model for primary SS through Fas-mediated apoptosis.


Treatment with anti-CD86 costimulatory molecule prevents the autoimmune lesions in murine Sjogren's syndrome (SS) through up-regulated Th2 response


Treatment with anti-CD 86 costimulatory molecule prevents the autoimmune lesions in murine Sjogren's syndrome(SS) through up-regulated Th2 response


The Rate of Cell Growth is Regulated by Purine Biosynthesis via ATP Production and G1 to S Phase Transition.


Theraputic effect of fosfomycin in animal model of sjögren's syndrome

シェーグレン症候群疾患モデルにおけるホスホマイシンの治療効果


慢性GVHDにおける口腔粘膜·口唇腺の免疫組織化学的研究

慢性GVHDにおける口腔粘膜·口唇腺の免疫組織化学的研究


Two cases of ameloblastic fibro-odontoma

エナメル上皮線維歯牙腫の2例

Japanese Journal of Oral & Maxillofacial Surgery


Estrogen Deficiency Accelerates Autoimmune Exocrinopathy in Murine Sjögren's Syndrome through Fas-Mediated Apoptosis