Regional specific modulation of the glycocalyx and smooth muscle cell contractile apparatus in conduit arteries of tail-suspended rats
Regional specific modulation of the glycocalyx and smooth muscle cell contractile apparatus in conduit arteries of tail-suspended rats
复制标题
尾悬大鼠导管动脉中糖萼和平滑肌细胞收缩装置的区域特异性调节
DOI：
10.1152/japplphysiol.00245.2015
复制
发表时间：
2016-03-01
影响因子：
3.3
通讯作者：
Deng, Xiaoyan
中科院分区：
文献类型：
--
作者：
Kang, Hongyan;Fan, Yubo;Deng, Xiaoyan
糖萼是血管细胞(内皮细胞和平滑肌细胞)表面的关键机械传感器，最近我们报道了尾悬吊(TS)后肢去负重大鼠血流动力学因子的重新分布以区域依赖的方式诱导内皮细胞的尺寸适应。在本研究中，我们研究了TS大鼠导管动脉中糖萼的覆盖率和基因表达及其与平滑肌收缩的可能关系。异硫氰酸荧光素标记的麦胚凝集素(WGA-FITC)染色对大鼠血管冰冻切片的面积分析表明，尾部悬吊3wk后，颈总动脉增加27.2%，相应的腹主动脉和股动脉减少13.3%和8.0%。TS大鼠颈总动脉Syndecan-2、Syndecan-3、Syndecan-4、Glypcan-1、平滑肌蛋白22(SM22)、SMTN和Calponin的相对mRNA水平分别增加到1.40、1.53、1.70、1.90、2.93、2.30和5.23倍。然而，在TS大鼠的腹主动脉和股动脉中，糖萼相关基因和平滑肌收缩装置都完全或部分下调。在标准化的糖萼覆盖率和标准化的SM22、SMTN和Calponin的mRNA水平之间存在线性正相关。这些结果表明，在模拟微重力条件下，糖萼的区域依赖性适应，可能影响其剪应力的机械转导，以调节平滑肌的收缩能力，最终导致航天后立位耐受。
The glycocalyx is a key mechanosensor on the surfaces of vascular cells (endothelial cells and smooth muscle cells), and recently, we reported that the redistribution of the hemodynamic factors in tail-suspended (TS) hindlimb-unloaded rats induces the dimensional adaptation of the endothelial glycocalyx in a regional-dependent manner. In the present study, we investigated the coverage and gene expression of the glycocalyx and its possible relationship with smooth muscle contractility in the conduit arteries from the TS rats. The coverage of the glycocalyx, determined by the area analysis of the fluorescein isothiocyanate-labeled wheat germ agglutinin (WGA-FITC) staining to the cryosections of rat vessels, showed a 27.2% increase in the common carotid artery, a 13.3 and 8.0% decrease in the corresponding abdominal aorta and the femoral artery after 3 wk of tail suspension. The relative mRNA levels of syndecan-2, 3, 4, glypican-1, smooth muscle protein 22 (SM22), smoothelin (SMTN), and calponin were enhanced to 1.40, 1.53, 1.70, 1.90, 2.93, 2.30, and 5.23-fold, respectively, in the common carotid artery of the TS rat. However, both glycocalyx-related genes and smooth muscle contractile apparatus were totally or partially down-regulated in the abdominal aorta and femoral artery of the TS rat. A linear positive correlation between the normalized coverage of glycocalyx and normalized mRNA levels of SM22, SMTN, and calponin exists. These results suggest the regional-dependent adaptation of the glycocalyx in simulated microgravity condition, which may affect its mechanotransduction of shear stress to regulate the contractility of the smooth muscle, finally contributing to postspaceflight orthostatic intolerance.