m-Calpain antagonizes RhoA overactivation and endothelial barrier dysfunction under disturbed shear conditions

摘要: Aims It has been reported that laminar shear flow (LF) improves barrier functions in vascular endothelial cells (ECs), whereas disturbed (DF) impairs the barrier. Our previous study showed LF stimulus led to activation of cysteine protease, m-calpain, ECs, which can influence RhoA activity. We hypothesized m-calpain participates pattern-dependent EC maintenance through signalling. Methods and results m-Calpain expression levels intima inferior aspect mouse aortic arch where DF dominates were higher than those adjacent regions. Elevation transendothelial albumin permeability, was induced by administration a calpain inhibitor (ALLM), prominent arch; moreover, this elevation abolished Rho kinase (ROCK) (Y-27632). Similarly, short interfering RNA (siRNA)-induced silencing resulted increased activity hyperpermeability arch, accompanied ROCK inhibitor-sensitive phosphorylation downstream effecter LIM 2 (LIMK2), stress fibre accumulation endothelium enhanced interendothelial gaps. Exposure human umbilical vein diminished activity; contrast, facilitated siRNA-induced further accelerated DF-induced overactivation, LIMK2, cytoskeletal rearrangement, resulting dysfunction cells. Conclusion findings revealed relatively high arch. The antagonizes overactivation RhoA/ROCK/LIMK2 signalling subsequent rearrangement leads improvement.