Sodium tanshinone IIA sulfonate promotes endothelial integrity via regulating VE-cadherin dynamics and RhoA/ROCK-mediated cellular contractility and prevents atorvastatin-induced intracerebral hemorrhage in zebrafish

Impaired vascular integrity leads to serious cerebral vascular diseases such as intracerebral hemorrhage (ICH). In addition, high-dose statin therapy is suggested to cause increased ICH risk due to unclear effects of general inhibition of 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) on the vascular system. Here we evaluated the protective effects of sodium tanshinone IIA sulfonate (STS), which has high efficacy and safety in clinical studies of ischemic stroke, by using atorvastatin (Ator) induced ICH zebrafish embryos and human umbilical vein endothelial cells (HUVECs). By using double transgenic Tg(flila:EGFP)yl & Tg(gatala:dsRed)sd2 zebrafish, we demonstrated that STS effectively reduced the occurrence and area of hemorrhage induced by Ator in zebrafish and restored impairment in motor function. We further demonstrated that Ator-induced disruption in VE-cadherin (VEC) containing cell-cell adherens junctions (AJs) in HUVECs by enhancing Src induced VEC internalization and RhoA/ROCK-mediated cellular contraction. STS inhibited Ator-induced Src activation and subsequent VEC internalization and actin depolymerization near cell borders, reducing lesions between neighboring cells and increasing barrier functions. STS also inhibited the Ator-induced RhoA/ROCK-mediated cellular contraction by regulating downstream LIMK/cofilin and MYPT1/MLC phosphatase signaling. These results showed that STS significantly promoted the stability of cell junctions and vascular integrity. Moreover, we observed that regulations of both Src and RhoA/ROCK are required for the maintenance of vascular integrity, and Src inhibitor (PP2) or ROCK inhibitors (fasudil and H1152) alone could not reduce the occurrence Ator-induced ICH. Taken together, we investigated the underlying mechanisms of Ator-induced endothelial instability, and provided scientific evidences of STS as potential ICH therapeutics by promoting vascular integrity.