基于肾小管上皮细胞外泌体miR-17-5p调控巨噬细胞M2型极化探讨大黄素干预急性肾损伤的机制研究

AKI后肾脏存在不完全修复、慢性炎症和进展性纤维化。M2型巨噬细胞分泌AIM与KIM-1结合促进坏死细胞清除及肾小管上皮细胞再生。外泌体作为细胞间信息交换媒介与巨噬细胞间存在相互作用，miR-17-5p促进肾小管上皮细胞损伤修复，但其调控巨噬细胞的机制尚不明确。前期研究证实大黄素具有抗氧化、保护血管内皮细胞及延缓肾脏纤维化的作用。故提出“大黄素干预肾小管上皮细胞外泌体miR-17-5p调控巨噬细胞M2型极化，促进AIM-KIM-1形成以阻抑AKI”的假说。拟复制肾脏缺血再灌注损伤及缺氧诱导肾小管上皮细胞损伤模型，采用免疫组化、流式细胞仪、Western blot及RT-PCR等技术，首先观察大黄素对AKI大鼠的干预效应；其次探讨大黄素对肾组织外泌体及M2巨噬细胞的影响；最后用PKH67标记的外泌体干预巨噬细胞，证实miR-17-5p诱导M2巨噬细胞活化，以揭示大黄素干预AKI的分子机制。

Incomplete repair, chronic inflammation, and progressive fibrosis are present in the kidney after AKI. AIM was secreted by M2 macrophages in combination with KIM-1 to promote debris removal of necrotic cells and regeneration of renal tubular epithelial cells.As an intercellular information exchange medium, exosomes interact with macrophages, and miR-17-5p promotes damage repair of renal tubular epithelial cells, but the mechanism of its regulation of macrophages is still unclear.Previous studies have confirmed that emodin has antioxidant, protective effects on vascular endothelial cells and retarding renal fibrosis.Therefore, the hypothesis that emodin can inhibit AKI by interfering with the exosome miR-17-5p of renal tubular epithelial cells to regulate the activation of M2 macrophages and promote the formation of AIM-KIM-1 was proposed. Plan to replicate the model of renal ischemia-reperfusion injury and hypoxia-induced renal tubular epithelial cell injury, and to use immunohistochemistry, flow cytometry, Western blot and RT-PCR to observe the intervention effect of emodin on AKI rats.Secondly, to investigate the effects of emodin on exosomes and M2 macrophages in renal tissues. Finally, PKH67-labeled exosomes were used to intervene macrophages, confirming that miR-17-5p induced the activation of M2 macrophages, so as to reveal the molecular mechanism of emodin interfering with AKI.