2D45 細胞骨格の変形分布とカルシウム応答の同時計測による細胞の力覚システムの検討

Abstract

This paper describes a novel method to investigate a cell mechanosensing system and the quantitative relationship between the deformation of cytoskeletal structure and the change of intracellular calcium ion concentration as biochemical response in a living cell stimulated by a micropipette. Gene transfection of green fluorescent protein enabled visualization of actin cytoskeleton in cells. Local deformation was applied to a cell by a micropipette and the displacement distribution of actin cytoskeleton in the whole cell was automatically obtained from the two images of the cell before and after deformation by using Kanade-Lucas-Tomasi method which is one of the feature tracking algorithms. Intracellular calcium ion response to the same mechanical stimulation was measured as the spatial and temporal changes of intensity of a fluorescent marker loaded to osteoblasts. These measurement were simultaneously conducted in order to clarify the mechanism of converting mechanical deformation into calcium signaling in a cell. As a result, the change of intracellular calcium ion concentration increases with increasing the displacement of actin cytoskeleton and calcium ion response starts in the area of large cytoskeletal displacement. These indicate that the deformation distribution of actin cytoskeleton is highly related to the cell mechanosensing system.