J0270204 FLIP法を用いた腱細胞間シグナル伝達に及ぼす力学負荷の影響([J027-02]細胞および分子のマイクロ・ナノスケール解析(2),バイオエンジニアリング部門)

Abstract

Gap junctions have been known to be involved in regulations of cell functions. It is also suggested that gap junction intercellular communications (GJICs) between tenocytes play an essential role in collagen synthesis in response to mechanical loadings. However, there were little knowledge on how GJICs are mechanically regulated and how changes in GJIC affect tenocyte functions. Accordingly, the present study has proposed a new numerical model to estimate intra- and intercellular diffusivity, based on one-dimensional diffusion theory, by fitting the model to data obtained from FLIP experiments, which visualises intercellular mass transport using a confocal laser microscope. Tenocytes were seeded within microgrooves integrated in a custom-made PDMS device, and were loaded with calcein-AM. FLIP experiment consisted of a series of instantaneous 100% power laser irradiation provided to one of tenocytes in a series every 2.6 second for 99 times, and fluorescence decay profiles of the targeted tenocyte and its neighbouring cells were obtained. Using the numerical model, intracellular and intercellular diffusion coefficient of tenocytes under static culture was estimated to be 25.3 and 1.06 μm^2/sec, respectively. The latter was significantly increased by an application of physiological, 4% tensile strain to the tenocytes, whereas that was significantly reduced by excessive, 8% tensile strain to the cells. Therefore, it can be concluded that physiological mechanical loading enhances intercellular communications, whereas non-physiological, overloading disrupt them.