■去SUMO酶sentrin特异性异肽酶2(SENP2)在动脉粥样硬化保护中起着至关重要的作用。然而,在受干扰的流动(D-flow)条件下,SENP2在T368处的磷酸化阻碍了其核功能并促进内皮细胞(EC)活化。SUMO化与D-流诱导的内皮-间质转化(endoMT)有关,但SENP2在抵消这一过程中的确切作用尚不清楚.
■我们开发了磷酸特异性SENP2S344抗体,并使用CRISPR/Cas9技术产生了具有SENP2S344A磷酸位点突变的敲入(KI)小鼠。然后,我们研究了SENP2S344磷酸化在两种不同的流动模式下以及在高胆固醇血症(HC)介导的EC激活过程中的作用。
■我们的发现表明,层流(L-flow)通过检查点激酶1(CHK1)的激活在S344诱导SENP2的磷酸化,导致抑制ERK5和p53SUMO化以及随后抑制EC激活。我们观察到雌性高胆固醇血症SENP2S344AKI小鼠的主动脉弓(在D流下)和降主动脉(在L流下)中脂质负荷病变的显着增加。在雄性高胆固醇血症SENP2S344AKI小鼠中,仅在主动脉弓区域观察到较大的脂质负荷病变,表明与雌性小鼠相比,雄性小鼠的HC介导的动脉粥样硬化较弱。电离辐射(IR)降低CHK1表达和SENP2S344磷酸化,减弱骨髓移植(BMT)后在雌性SENP2S344AKI小鼠中观察到的前动脉粥样硬化作用,特别是在L流地区。磷酸化位点突变SENP2S344A上调了与EC激活相关的过程,包括炎症,迁移,和扩散。此外,观察到EC标记基因的纤维化变化和上调表达。细胞凋亡在SENP2S344AKI小鼠肺来源的ECs中增加,主要通过抑制ERK5介导的DNA损伤诱导的凋亡抑制因子(DDIAS)的表达。
■在这项研究中,我们揭示了L-流对EC炎症抑制作用的新机制,迁移,扩散,凋亡,和纤维化变化通过促进CHK1诱导的SENP2S344磷酸化。磷酸位点突变SENP2S344A通过不同的机制响应L流,这涉及间充质和EC标记基因的上调。
UNASSIGNED: The deSUMOylase sentrin-specific isopeptidase 2 (SENP2) plays a crucial role in atheroprotection. However, the phosphorylation of SENP2 at T368 under disturbed flow (D-flow) conditions hinders its nuclear function and promotes endothelial cell (EC) activation. SUMOylation has been implicated in D-flow-induced endothelial-to-mesenchymal transition (endoMT), but the precise role of SENP2 in counteracting this process remains unclear.
UNASSIGNED: We developed a phospho-specific SENP2 S344 antibody and generated knock-in (KI) mice with a phospho-site mutation of SENP2 S344A using CRISPR/Cas9 technology. We then investigated the effects of SENP2 S344 phosphorylation under two distinct flow patterns and during hypercholesteremia (HC)-mediated EC activation.
UNASSIGNED: Our findings demonstrate that laminar flow (L-flow) induces phosphorylation of SENP2 at S344 through the activation of checkpoint kinase 1 (CHK1), leading to the inhibition of ERK5 and p53 SUMOylation and subsequent suppression of EC activation. We observed a significant increase in lipid-laden lesions in both the aortic arch (under D-flow) and descending aorta (under L-flow) of female hypercholesterolemic SENP2 S344A KI mice. In male hypercholesterolemic SENP2 S344A KI mice, larger lipid-laden lesions were only observed in the aortic arch area, suggesting a weaker HC-mediated atherogenesis in male mice compared to females. Ionizing radiation (IR) reduced CHK1 expression and SENP2 S344 phosphorylation, attenuating the pro-atherosclerotic effects observed in female SENP2 S344A KI mice after bone marrow transplantation (BMT), particularly in L-flow areas. The phospho-site mutation SENP2 S344A upregulates processes associated with EC activation, including inflammation, migration, and proliferation. Additionally, fibrotic changes and up-regulated expression of EC marker genes were observed. Apoptosis was augmented in ECs derived from the lungs of SENP2 S344A KI mice, primarily through the inhibition of ERK5-mediated expression of DNA damage-induced apoptosis suppressor (DDIAS).
UNASSIGNED: In this study, we have revealed a novel mechanism underlying the suppressive effects of L-flow on EC inflammation, migration, proliferation, apoptosis, and fibrotic changes through promoting CHK1-induced SENP2 S344 phosphorylation. The phospho-site mutation SENP2 S344A responds to L-flow through a distinct mechanism, which involves the upregulation of both mesenchymal and EC marker genes.