LncRNA通过miR-21影响的凋亡在造影剂所致急性肾损伤中的发生机制研究

Contrast induced acute kidney injury(CI-AKI) is a common complication after contrast exposure.CI-AKI significantly increased the risk of cardiovascular and renal adverse events, and medical costs. Previous studies have demonstrated cell apoptosis plays an important role in the development of CI-AKI, and micRNA21 may target PDCD4 regulating apoptosis in AKI models after ischemia. In addition, long chain non-coding RNA (LncRNA) has been proved to regulate the apoptosis by mediating miRNA. Our previous studies have established a clinical common CI-AKI model based on low-osmolar, and demonstrated that the level of miR-21 and cell apoptosis were significantly higher than the controls. However, it is still unclear whether lncRNAs correlate to cell apoptosis in CI-AKI by regulating the signaling pathway of miR-21-PDCD4. Therefore, based on our previous researches, we aimed to investigate: (1) Verifying the regulating effect of miR-21 targeting PDCD4; the effect of miR-21 targeting PDCD4 on apoptosis in the CI-AKI renal tubular cell；(2) Verifying the regulating effect of LncRNA targeting microRNA-21; (3) Investigating the animal models and the patients’ blood samples to demonstrate the molecular network mechanism of LncRNA—microRNA-21—PDCD4 axis in cell apoptosis of CI-AKI，and develop a new direction for CI-AKI prevention and treatment.

随着造影剂日益广泛使用，造影剂致急性肾损伤（CI-AKI）发生率明显升高，显著增加心肾不良事件和医疗费用。研究表明凋亡参与CI-AKI发生，micRNA21可能在缺血致AKI中靶向PDCD4调控凋亡，而长链非编码RNA（LncRNAs）可调控miRNA影响凋亡。我们前期率先建立低渗造影剂CI-AKI动物模型，并发现 CI-AKI中miRNA-21与凋亡水平明显高于对照组，但尚不明确lncRNAs是否通过调控miR21-PDCD4而参与CI-AKI的凋亡。本课题拟在前期研究上(1)明确miRNA-21对PDCD4的靶向调控；证实miRNA-21调控PDCD4对肾小管上皮细胞凋亡的影响；(2)证实CI-AKI相关的LncRNA对miRNA-21的靶向调控；(3)动物模型和患者血液标本证实LncRNA-miRNA-21-PDCD4影响的凋亡在CI-AKI的重要作用，为CIAKI防治开拓新方向。

随着造影剂日益广泛使用，造影剂致急性肾损伤（CI-AKI）发生率明显升高，显著增加心 肾不良事件和医疗费用。研究表明凋亡参与CI-AKI发生，micRNA21可能在缺血致AKI中靶向PDC D4调控凋亡。本课题组创新性的采用碘普罗胺诱导大鼠造影剂所致急性肾损伤的发生，从而成功构建贴近临床的、稳定的新型大鼠造影剂所致急性肾损伤模型，并获得国家新型发明专利授权（详见附件）。（1）通过对新型大鼠造影剂所致急性肾损伤模型测序及其生物信息学分析，发现miR-21水平在造影剂所致急性肾损伤大鼠中表达明显增高，生物信息学预测miR-21可能通过结合PDCD4 3’UTR 区，调控凋亡的发生；（2）通过构建 miR-21 类似物及抑制剂，构建 miR-21 稳定高表达及低表达HK-2细胞，检测HK-2细胞凋亡发生率及凋亡相关蛋白表达情况，探讨miR-21 在肾小管上皮细胞凋亡调控的分子机制。（3）完成荧光素酶活性报告分析 miR-21是通过PDCD4基因 UTR 区抑制荧光素酶的活性，明确 miR-21与PDCD4存在明确的靶向调控作用关系。从而为CIAKI防治开拓新方向。