繰返伸展刺激下での血管平滑筋細胞の内部構造変化の解析

抄録

Vascular smooth muscle cells (VSMCs) constitute the main components of blood vessel walls and regulate contraction and dilation of the walls. VSMCs change their intracellular structures and physiological functions adaptively in response to excessive forces due to a chronic increase in the blood pressure, i.e. hypertension. These responses are deeply involved in vascular pathophysiology in diseases such as arteriosclerosis. Therefore, it is important to clarify how VSMCs change their intracellular structures such as cytoskeletons and the nucleus during exposure to mechanical stimuli. Here, we developed a new stretching apparatus to obtain high magnification images of the cells during cyclic stretch stimulation maintaining cell culture environment. By using this apparatus, the morphological changes of cells and their nucleus during cyclic stretching were investigated. We found that the deformation of the cell nucleus during cyclic stretching was significantly increased in the cells whose contractile forces of actin stress fibers were increased with calyculin A treatment. These results indicate that the mechanical connection between actin cytoskeleton and the nucleus may be reinforced by increasing of intracellular mechanical forces, and the force transmission efficiency from cytoskeletons to the nucleus might be improved with contractile activation.