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【答案】应助回帖
★ ★ ★ 感谢参与,应助指数 +1 wizardfan: 金币+3, BioEPI+1, 看上去是篇摘要,能把文章链接贴出就更好了,还有最好能高亮你的回答。最后活动期间给个EPI 奖励,以后多应助哈 2013-04-22 07:49:12
Background: Cells resident in certain hollow organs are subjected routinely to large transient stretches, including every
adherent cell resident in lungs, heart, great vessels, gut, and bladder. We have shown recently that in response to a transient
stretch the adherent eukaryotic cell promptly fluidizes and then gradually resolidifies, but mechanism is not yet understood.
Principal Findings: In the isolated human bladder smooth muscle cell, here we applied a 10% transient stretch while
measuring cell traction forces, elastic modulus, F-actin imaging and the F-actin/G-actin ratio. Immediately after a transient
stretch, F-actin levels and cell stiffness were lower by about 50%, and traction forces were lower by about 70%, both indicative
of prompt fluidization. Within 5min, F-actin levels recovered completely, cell stiffness recovered by about 90%, and traction
forces recovered by about 60%, all indicative of resolidification. The extent of the fluidization response was uninfluenced by a
variety of signaling inhibitors, and, surprisingly, was localized to the unstretch phase of the stretch-unstretch maneuver in a
manner suggestive of cytoskeletal catch bonds. When we applied an ‘‘unstretch-restretch’’ (transient compression), rather than
a ‘‘stretch-unstretch’’ (transient stretch), the cell did not fluidize and the actin network did not depolymerize.
Conclusions: Taken together, these results implicate extremely rapid actin disassembly in the fluidization response, and slow actin
reassembly in the resolidification response. In the bladder smooth muscle cell, the fluidization response to transient stretch occurs
not through signaling pathways, but rather through release of increased tensile forces that drive acute disassociation of actin.
β-actin作为一个亚基结构存在。前面有人说的有一点点道理,都是cytoskeletal里面的结构。 |
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