Corticotrophin-releasing hormone (CRH) has been demonstrated to participate in vascular inflammation and permeability. Our previous studies have shown that blockade of S1PR2 or CRHR1 inhibited H₂O₂-induced brain endothelial hyperpermeability via inhibiting cPLA₂ phosphorylation. However, little is known about the linkage between S1PRs and CRHR1 in oxidative stress-induced cerebrovascular endothelial hyperpermeability. Here we observed the opposite effects of S1PR2 to those of S1PR3 on the monolayer permeability of bEnd3 cells in response to H₂O₂. Interestingly, activation of CRHR1 was found to reverse the effects resulting from blockade/silencing of both S1PR2 and S1PR3. In bEnd3 monolayer, blockade/knockdown of S1PR2 reduced the endothelial hyperpermeability and suppressed the tight junction protein ZO-1 redistribution caused by H₂O₂, along with the inhibition of p38, ERK and cPLA₂ phosphorylation. On the contrary, suppression/silencing of S1PR3 further promoted H₂O₂-induced endothelial hyperpermeability and ZO-1 redistribution, accompanied by the increased phosphorylation of p38, ERK and cPLA₂. In the presence of CRH, the effects resulting from the suppression of both S1PR2 and S1PR3 were abolished. Our results elucidate a possible linkage between CRHR1 and S1PR2/S1PR3 involving in the regulation of endothelial monolayer permeability under oxidative stress condition.

已证明促肾上腺皮质激素释放激素 (CRH) 参与血管炎症和通透性。我们之前的研究表明，阻断 S1PR2 或 CRHR1通过抑制 cPLA ₂磷酸化来抑制 H ₂ O _{2诱导的脑内皮细胞通透性过高。}然而，关于 S1PRs 和 CRHR1 在氧化应激诱导的脑血管内皮高通透性中的联系知之甚少。在这里，我们观察到 S1PR2 与 S1PR3 对 bEnd3 细胞响应 H ₂ O _{2的单层渗透性的相反影响}. 有趣的是，发现 CRHR1 的激活可以逆转 S1PR2 和 S1PR3 的阻断/沉默所产生的影响。在 bEnd3 单层中，S1PR2 的阻断/敲低降低了内皮细胞的高通透性并抑制了由 H ₂ O ₂引起的紧密连接蛋白 ZO-1 再分布，同时抑制了 p38、ERK 和 cPLA ₂磷酸化。相反，S1PR3 的抑制/沉默进一步促进了 H ₂ O ₂诱导的内皮通透性过高和 ZO-1 再分布，伴随着 p38、ERK 和 cPLA _{2的磷酸化增加}. 在存在 CRH 的情况下，抑制 S1PR2 和 S1PR3 所产生的影响被消除了。我们的结果阐明了 CRHR1 和 S1PR2/S1PR3 之间可能存在的联系，涉及在氧化应激条件下调节内皮单层通透性。