Department of Emergency, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, 250021, China.
Department of Emergency, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, 250021, China.
Biochem Biophys Res Commun. 2020 May 7;525(3):812-818. doi: 10.1016/j.bbrc.2020.02.151. Epub 2020 Mar 10.
Shear stress (SS) and renin-angiotensin system (RAS) play important roles in endothelium homeostasis. Previous studies demonstrated that pulsatile shear stress (PSS) reduced the expression and activity of angiotensin-converting enzyme (ACE), however, the effect of SS on angiotensin-converting enzyme 2 (ACE2) expression is unclear.
We exposed cultured endothelial cells (ECs) to distinct patterns of SS for indicated time points, Western blot and RT-PCR were used to determine the ACE2 expression; En Face staining was used to detect ACE2 expression in vivo; cell proliferation and apoptosis were determined by BrdU staining and TUNEL staining, respectively; the production of NO was detected by a commercial kit; the promoter activity of ACE2 was determined by a Dual-Luciferase Reporter Assay System, inhibitors of ACE2 and signaling pathway were added to the medium 1 h prior for PSS. Our data showed PSS induced a sustained ACE2 expression, but OSS only induced a transient ACE2 expression. The PSS-induced ACE2 expression was higher than that of OSS both in vitro and in vivo. The PSS-induced ACE2 was involved in inhibiting proliferation and inflammation, as well as promoting NO production in ECs. PSS significantly increased ACE2 expression at transcriptional level via activating AMPKα2-KLF2 pathway.
Our results suggest PSS promotes ACE2 expression via AMPKα2-KLF2 pathway to maintain the normal EC functions.
切应力（SS）和肾素-血管紧张素系统（RAS）在血管内皮细胞稳态中发挥重要作用。先前的研究表明，脉动切应力（PSS）降低血管紧张素转换酶（ACE）的表达和活性，然而，SS 对血管紧张素转换酶 2（ACE2）表达的影响尚不清楚。
我们将培养的内皮细胞（ECs）暴露于不同模式的 SS 中不同的时间点，通过 Western blot 和 RT-PCR 检测 ACE2 的表达；通过 En Face 染色检测 ACE2 的体内表达；通过 BrdU 染色和 TUNEL 染色分别检测细胞增殖和凋亡；通过商业试剂盒检测 NO 的产生；通过双荧光素酶报告基因检测系统测定 ACE2 的启动子活性，在 PSS 之前 1 小时向培养基中加入 ACE2 和信号通路的抑制剂。我们的数据表明，PSS 诱导 ACE2 的持续表达，但 OSS 仅诱导 ACE2 的瞬时表达。在体外和体内，PSS 诱导的 ACE2 表达均高于 OSS。PSS 通过激活 AMPKα2-KLF2 通路在转录水平上显著增加 ACE2 的表达，从而抑制 ECs 的增殖和炎症，并促进 NO 的产生。
我们的结果表明，PSS 通过 AMPKα2-KLF2 通路促进 ACE2 的表达，以维持正常的 EC 功能。
