外泌体来源的miRNA-122介导H2S对LPS所致急性肾损伤的保护作用研究

H2S has a protective effect on LPS-induced AKI, but the mechanism has not been fully elucidated. The applicant found that H2S can promote the release of exosomes in primary renal tubular epithelial cells, and the exosomes can protect LPS-induced AKI. In addition, microRNAs array is used to screen differentially expressed miRNAs in exosomes and miRNA-122 was found to be up-regulated significantly by H2S. Therefore, it is supposed that H2S protects kidney function by regulating the expression and release of miRNA-122 in exosomes, and reducing the mortality of AKI caused by LPS. In this program we will intervene exosomal miRNA-122 in LPS-induced mouse AKI model and renal tubular epithelial cell injury model to explore whether H2S play a protective role by regulating exosomal miRNA-122. In together, we expect to illustrate the mechanism of H2S to protect AKI caused by LPS.

H2S对LPS诱导的急性肾损伤（acute kidney injury, AKI）具有保护作用，但其机制尚未完全阐明。申请者前期研究发现，H2S能够促进原代肾小管上皮细胞中外泌体的释放；将此外泌体经尾静脉注射入小鼠体内，发现其对LPS诱导的AKI具有保护作用；进一步采用芯片筛选外泌体中差异表达的miRNAs，发现H2S使miRNA-122显著上调，故提出假说：H2S通过调控外泌体中miRNA-122的表达与释放，保护肾脏功能，从而降低LPS所致AKI的死亡率。针对上述假说，本项目拟以LPS诱导的小鼠AKI模型及肾小管上皮细胞损伤模型为研究对象，采用体内外干预Exosomes/miRNA-122的策略，从整体动物、细胞及分子水平探讨H2S是否通过调节外泌体中miRNA-122的表达与释放保护AKI。开展本项目研究，将进一步解析H2S保护LPS所致AKI的机制，为AKI的防治提供新线索。

急性肾损伤(acute kidney injury，AKI)是一种临床常见的综合症，在重症监护室中50-80％的死亡率与AKI有关。研究表明，H2S对LPS诱导的AKI具有保护作用，但其作用机制尚未完全阐明。本研究发现，H2S能够促进原代肾小管上皮细胞中外泌体的释放；将此外泌体注射入小鼠肾脏，发现其对LPS所致小鼠AKI具有保护作用；进一步采用芯片筛选受H2S调控的外泌体中差异表达的miRNA，发现外泌体中的miRNA-122在H2S的作用下上调；将miRNA-122 mimic/inhibitor转入细胞，发现miRNA-122对LPS所致肾小管上皮细胞的损伤具有保护作用。采用miRNA-122 inhibitor降低外泌体中miRNA-122的表达，可以逆转H2S对细胞的保护作用。采用miRNA靶基因预测软件预测miRNA-122的靶基因，发现miRNA-122可以调控PKM2的表达，进一步采用双荧光素酶分析确定二者具有直接靶向关系。综上所述，H2S可能部分通过调节Exsomes/miRNA-122的表达保护LPS诱导的AKI。本研究从整体动物、细胞及分子水平三个层次对H2S的调控机制进行深入研究，进一步解析了H2S保护LPS所致AKI的机制，为AKI的防治提供了新的线索。