S022011 血管平滑筋細胞内ストレスファイバの配向再現性に関する研究 : 中間径フィラメントとストレスファイバの相互作用の検討([S02201]細胞および分子のマイクロ・ナノスケール解析(1))

抄録

Stress fibers (SFs) play essential roles in various cellular events including cell movement and shape maintenance. They reorganize themselves in response to the mechanical environment as well. Recently, we found that SFs reappeared after temporal disruption with cytochalasin D had similar orientation to those before disruption in vascular smooth muscle cells (SMCs). This may indicate the cells have a memory of SF orientation. We previously found that focal adhesion arrangement served as this memory, while microtubules acted as its eraser. However, the role of intermediate filaments (IFs) to the memory remained unclear. Here we investigated the effects of IFs during the reorganization process of SFs. We preconditioned SMCs with cyclic stretch to make their SFs align in a uniform direction. We then disrupted SFs completely with cytochalasin D for 1 h, and let them reorganize in the drug-free medium for 3 h. IFs were disrupted with acrylamide during the disruption or reorganization process of SFs. The reorganized SFs appeared as they had been in the presence of IFs, while SFs showed random orientation in the absence of IFs. Interestingly, the orientation of SFs tended to coincide with that of IFs following the temporal disruption and the subsequent reorganization of both SFs and IFs, simultaneously. These results may indicate that IFs have a potential interaction with SFs and serve as a guide leading SFs to focal adhesions to facilitate their memory of orientation.