背景:脓毒症诱导的急性肺损伤(ALI)与低生存率相关。确定预防脓毒症诱导的ALI的潜在治疗靶标具有临床重要性。本研究旨在探讨雌激素相关受体α(ERRα)在脓毒症诱导的ALI中的作用。
方法:采用脂多糖(LPS)模拟脓毒症诱导的大鼠肺微血管内皮细胞(PMVECs)ALI模型。ERRα过表达和敲低对LPS诱导的内皮通透性的影响,通过辣根过氧化物酶通透性测定法测定细胞凋亡和自噬,TdT介导的dUTP尼克末端标记(TUNEL)测定,流式细胞术,免疫荧光染色,RT-PCR和蛋白质印迹。采用盲肠结扎穿刺术麻醉大鼠建立脓毒症致ALI大鼠模型,验证体外实验结果。将动物随机分配以接受载体或ERRα激动剂的腹膜内注射。肺血管通透性,病理损伤,检测细胞凋亡和自噬。
结果:ERRα的过表达改善了LPS诱导的内皮高通透性,粘附连接分子的降解,bax的上调,切割的半胱天冬酶3和切割的半胱天冬酶9水平,下调抗凋亡蛋白Bcl-2水平,促进了自噬通量的形成,而ERRα的敲除加剧了LPS诱导的细胞凋亡,抑制了自噬的激活。ERRα激动剂的给药减轻了肺组织的病理损伤,增加紧密连接蛋白和粘附连接蛋白的水平,并降低凋亡相关蛋白的表达。促进ERRα的表达显著增强了自噬过程,降低了CLP诱导的ALI。机械上,ERRα对于调节自噬和凋亡之间的平衡以维持粘附连接的完整性至关重要。
结论:ERRα通过ERRα介导的细胞凋亡和自噬保护脓毒症诱导的ALI。ERRα的激活为预防脓毒症诱导的ALI提供了新的治疗机会。
Sepsis-induced acute lung injury (ALI) is associated with poor survival rates. The identification of potential therapeutic targets for preventing sepsis-induced ALI has clinical importance. This study aims to investigate the role of estrogen-related receptor alpha (
ERRα) in sepsis-induced ALI.
Lipopolysaccharide (LPS) was used to simulate sepsis-induced ALI model in rat pulmonary microvascular endothelial cells (PMVECs). The effects of
ERRα overexpression and knockdown on LPS-induced endothelial permeability, apoptosis and autophagy were determined by horseradish peroxidase permeability assay, TdT-mediated dUTP Nick End Labeling (TUNEL) assay, flow cytometry, immunofluorescence staining, RT-PCR and Western Blotting. The rat model with sepsis-induced ALI was established by cecal ligation and puncture in anesthetized rats to verify the results of in vitro experiments. Animals were randomly assigned to receive intraperitoneal injection of vehicle or
ERRα agonist. Lung vascular permeability, pathological injury, apoptosis and autophagy were examined.
Overexpression of ERRα ameliorated LPS-induced endothelial hyperpermeability, degradation of adherens junctional molecules, upregulation of bax, cleaved caspase 3 and cleaved caspase 9 levels, downregulation of anti-apoptotic protein Bcl-2 level, and promoted the formation of autophagic flux, while the knockdown of ERRα exacerbated LPS-induced apoptosis and inhibited the activation of autophagy. Administration of ERRα agonist alleviated the pathological damage of lung tissue, increased the levels of tight junction proteins and adherens junction proteins, and decreased the expression of apoptosis-related proteins. Promoting the expression of ERRα significantly enhanced the process of autophagy and reduced CLP-induced ALI. Mechanistically, ERRα is essential to regulate the balance between autophagy and apoptosis to maintain the adherens junctional integrity.
ERRα protects against sepsis-induced ALI through
ERRα-mediated apoptosis and autophagy. Activation of
ERRα provides a new therapeutic opportunity to prevent sepsis-induced ALI.