type: misc

label: url

en: スキャンレス光コム顕微鏡~光コムを用いたスキャンレス共焦点位相イメージング~

ja: スキャンレス光コム顕微鏡~光コムを用いたスキャンレス共焦点位相イメージング~

en: JAPANESE JOURNAL OF OPTICS

ja: 光学


en: 光コムを用いたスキャンレス共焦点位相イメージング

ja: 光コムを用いたスキャンレス共焦点位相イメージング


en: Orientation analysis of collagen fibers in healing tendon by using second-harmonic-generation microscopy

en: Progress in Biomedical Optics and Imaging - Proceedings of SPIE


en: 高時間・空間分解能観察に対応する新規な細胞伸展マイクロデバイスの開発

ja: 高時間・空間分解能観察に対応する新規な細胞伸展マイクロデバイスの開発

en: In this study, we have developed a novel cell stretching micro device to observe cellular response to mechanical stimuli with high spatial and temporal resolution. In conventional cell stretching device, rigid displacement of cell body during stretching operation is not negligible. And this rigid displacement makes it difficult to observe instant initial cellular response to stretching. The novel micro device is fabricated by applying MEMS technique, and consists of a transparent elastic micro chamber and a micro linkage mechanism. The micro chamber and linkage mechanism is fabricated by micro molding and multiple exposure technique of photoresist, respectively. We demonstrated availability of fabrication process, and evaluated performance of the micro device. When applying a stretch to chamber, rigid displacement was well suppressed. This result indicated a potential of this device to observe instant initial cellular response to stretching mechanical stimuli.

en: Transactions of The Japan Society of Mechanical Engineers, Series C

ja: 日本機械学会論文集(C編)


en: Directional dependence of osteoblastic calcium response to mechanical stimuli.

en: In adaptive bone remodeling, mechanical signals such as stress/strain caused by loading/deformation are believed to play important roles as regulators of the process in which osteoclastic resorption and osteoblastic formation are coordinated under a local mechanical environment. The mechanism by which cells sense and transduce mechanical signals to the intracellular biochemical signaling cascade is still unclear, however to address this issue, the present study investigated the characteristic response of a single osteoblastic cell, MC3T3-E1, to a well-defined mechanical stimulus and the involvement of the cytoskeletal actin fiber structure in the mechanotransduction pathway. First, by mechanically perturbing to a single cell using a microneedle, a change in the intracellular calcium ion concentration [Ca(2+)](i) was observed as a primal signaling response to a mechanical stimulus, and the threshold value of the perturbation as the mechanical stimulus was evaluated quantitatively. Second, to study directional dependence of the response to the mechanical stimulus, the effect of actin fiber orientation on the threshold value of the calcium response was investigated at various magnitudes and directions of the stimulus. It was found that the osteoblastic response to the perturbation exhibited a directional dependence. That is, the sensitivity of osteoblastic cells to a mechanical stimulus depends on the angle of the applied deformation with respect to the cytoskeletal actin fiber orientation. This finding is phenomenological evidence that cytoskeletal actin fiber structures are involved in the mechanotransduction mechanism, which may be related to cell polarization behaviors such as cellular alignment caused by mechanical stimulation.

en: Biomechanics and Modeling in Mechanobiology


en: Role of the Organized Cytoskeletal Actin Fiber Structure in Osteoblastic Response to Mechanical Stimulus

ja: アクチン細胞骨格構造の量が培養骨芽細胞の力学刺激応答特性に及ぼす影響

en: Bone responds to change in mechanical environment and adaptively remodels the internal structure and external shape. Therefore, for bone cells, such as bone-forming osteoblasts, a mechanical stimulus as well as biochemical signaling plays an important role in the regulation of their activities. Many studies on various osteoblastic responses to mechanical stimulus have been reported ; however, the mechanosensory mechanism by which cells sense the stimulus and translate it to biochemical signaling is not clearly understood. Cytoskeletal actin fibers have been proposed as one of the candidates playing an important role in the mechanosensory mechanism. In this study, we hypothesize that the organized network structure of actin fibers is essential in the mechanosensory mechanism. Three groups of osteoblas-like cells with different amounts of controlled actin fiber structure were prepared by controlling polymerization time after treatment with cytochalasin D. By applying mechanical stimulus to a single osteoblast-like cell, as localized deformation of the cytomembrane by direct indentation with a glass microneedle, a calcium signaling response to the stimulus was observed using a fluorescent calcium indicator, Fluo 4, under a confocal laser-scanning microscope. As a result, cells responded more sensitively to the applied deformation with a larger amount of actin fiber structure, and a few cells without an organized structure responded to stimulus as well. These results suggest that the organized actin fiber structure is not necessarily essential in the mechanism by which the mechanical stimulus is transduced into a calcium signaling response, but plays a supporting role indirectly, such as improving the efficiency of transmitting the stimulus to the cell or amplifying the stimulus itself.

en: Transactions of the Japanese Society for Medical and Biological Engineering

ja: 生体医工学