在人结肠平滑肌收缩和转染 caveolin-1 cDNA 的老年大鼠结肠中，caveolin-1 的实时动态运动。
Real-time dynamic movement of caveolin-1 during smooth muscle contraction of human colon and aged rat colon transfected with caveolin-1 cDNA.
机构信息
Gastrointestinal Molecular Motors Laboratory, Department of Pediatrics, Gastroenterology, University of Michigan Medical Center, Ann Arbor, USA.
出版信息
Am J Physiol Gastrointest Liver Physiol. 2011 Jun;300(6):G1022-32. doi: 10.1152/ajpgi.00301.2010. Epub 2011 Mar 3.
Caveolin-1 (cav-1) plays a key role in PKC-α and RhoA signaling pathways during acetylcholine (ACh)-induced contraction of colonic smooth muscle cells (CSMC). Aged rat CSMC showed sluggish contractility, concomitant with reduced expression of cav-1 with an associated reduction in activation of PKC-α and RhoA signaling pathway. Real-time monitoring of live human CSMC transfected with yellow fluorescent protein-tagged wild-type caveolin 1 cDNA (YFP-wt-cav-1) cDNA in the present study suggests that cav-1 cycles within and along the membrane in a synchronized, highly organized cytoskeletal path. These studies provide, for the first time, the advantages of real-time monitoring of the dynamic movement of caveolin in living cells. Rapid movement of cav-1 in response to ACh suggests its dynamic role in CSMC contraction. Human CSMC transfected with YFP-ΔTFT-cav-1 dominant negative cDNA show fluorescence in the cytosol of the CSMC and no movement of fluorescent cav-1 in response to ACh mimicking the response shown by aged rat CSMC. Transfection of CSMC from aged rat with YFP-wt-cav-1 cDNA restored the physiological contractile response to ACh as well as the dynamic movement of cav-1 along the organized cytoskeletal path observed in normal adult CSMC. To study the force generation by CSMC, three-dimensional colonic rings were bioengineered. Colonic bioengineered rings from aged CSMC showed reduced force generation compared with colonic bioengineered rings from adult CSMC. Colonic bioengineered rings from aged CSMC transfected with wt-cav-1 cDNA showed force generation similar to colonic bioengineered rings from adult rat CSMC. The data suggest that contraction in CSMC is dependent on cav-1 reorganization dynamics, which restores the physiological contractile response in aged CSMC. We hypothesize that dynamic movement of cav-1 is essential for physiological contractile response of colonic smooth muscle.
窖蛋白-1（cav-1）在乙酰胆碱（ACh）诱导的结肠平滑肌细胞（CSMC）收缩过程中，在蛋白激酶 C-α（PKC-α）和RhoA 信号通路中发挥关键作用。老年大鼠 CSMC 的收缩性迟钝，同时窖蛋白-1 的表达减少，与之相关的 PKC-α 和 RhoA 信号通路的激活也减少。本研究实时监测转染了黄色荧光蛋白标记的野生型窖蛋白 1 cDNA（YFP-wt-cav-1）的人 CSMC，结果表明窖蛋白-1 在膜内和膜上沿着同步、高度组织化的细胞骨架路径循环。这些研究首次提供了实时监测活细胞中窖蛋白动态运动的优势。ACh 快速运动提示其在 CSMC 收缩中的动态作用。转染 YFP-ΔTFT-cav-1 显性负性 cDNA 的人 CSMC 在 CSMC 的细胞质中显示荧光，并且对 ACh 没有荧光窖蛋白-1 的运动，这与老年大鼠 CSMC 的反应相似。用 YFP-wt-cav-1 cDNA 转染老年大鼠 CSMC，恢复了对 ACh 的生理收缩反应，以及观察到的正常成年 CSMC 中沿着有组织的细胞骨架路径的窖蛋白-1 的动态运动。为了研究 CSMC 的力产生，构建了三维结肠环。与成年 CSMC 的结肠生物工程环相比，老年 CSMC 的结肠生物工程环产生的力减少。用 wt-cav-1 cDNA 转染老年大鼠的结肠生物工程环显示出与成年大鼠 CSMC 的结肠生物工程环相似的力产生。数据表明 CSMC 的收缩依赖于窖蛋白-1 的重组动力学，这恢复了老年 CSMC 的生理收缩反应。我们假设窖蛋白-1 的动态运动对于结肠平滑肌的生理收缩反应是必不可少的。
Zotero 插件