miR-497 在腹膜透析超滤衰竭中的作用机制研究

Peritoneal fibrosis (PF) caused by long-term peritoneal dialysis (PD) eventually leads to ultrafiltration failure which is one of the main causes for patients quiting PD, but the exact mechanism is still unknown. . Inflammation, angiogenesis and peritoneal mesothelial cells injury are the main causes of ultrafiltration failure. Vascular endothelial growth factor (VEGF) was involved in the processes of inflammation, angiogenesis and peritoneal mesothelial cells injury. Further studies showed that the formation of tumor angiogenesis and accumulation of extracellular matrix could be inhibited by miR-497. Our previous study demonstrated that the expressions of miR-497 were decreased and VEGF were increased in peritoneal mesothelial cells injured by high glucose. Additionally, we found that VEGF may be the target gene of miR-497 by bioinformatics analysis. . Thus, we propose that miR-497/VEGF pathway may participate in the PF leading to ultrafiltration failure. This project intends to use lentiviral vector to inhibit or over-express miR-497. We will investigate the histological and morphological change of peritoneum in human peritoneal mesothelial cells, uremic PD rats and PD patients. The impact of high glucose and uremia on the transcription and expression of PF related genes, which including TGF-β1, ECM (Col-Ⅳ and FN), MMP-2, MMP-9 and other related genes was detected. The aim is to reveal the role of miR-497/ VEGF pathway in PD. This will provide new clinical evidences for reversing or preventing ultrafiltration failure.

长期腹膜透析( PD)引起的腹膜纤维化最终将导致超滤衰竭，具体机制未明。已有研究表明，腹膜炎症、血管新生和间皮细胞损伤是腹膜纤维化的重要机制。血管内皮生长因子(VEGF)在腹膜炎症、血管新生和间皮细胞损伤中发挥重要作用。miR-497高表达可抑制肿瘤组织血管新生及细胞外基质积聚。我们前期实验证明高糖可诱导损伤的腹膜间皮细胞miR-497表达减少，VEGF表达增多。生物信息学提示VEGF是miR-497的靶基因。我们提出假设：miR-497通过VEGF参与腹膜纤维化，导致超滤衰竭。为证明此假设，本项目拟利用人腹膜间皮细胞、尿毒症PD大鼠、尿毒症PD患者腹膜组织观察腹膜纤维化因子TGF-β1、ECM（Col-Ⅳ和FN）、MMP-2、MMP-9等相关基因的转录和表达变化，从分子水平揭示miR-497/VEGF通路在腹膜纤维化中的作用，为防治腹膜纤维化，延缓PD患者超滤衰竭的发生提供新思路。

终末期肾脏病（end stage renal disease, ESRD）是 21 世纪全人类面临的主要健康问题之一。临床研究发现随着患者 PD 时间延长，将引起腹膜形态和功能的改变，最终引起腹膜纤维化(Peritoneal fibrosis，PF)，导致超滤衰竭(Ultrafiltration Failure，UFF)。因此，探索腹膜纤维化的发生机制，寻找缓解腹膜纤维化的新治疗措施对患者维持 PD 极为重要。本研究应用生物信息学软件分析发现，VEGF 可能是 miR-15a 的靶基因并通过双荧光素酶法进行了验证。本项目通过细胞实验验证了高糖能刺激人腹膜间皮细胞发生转分化，使 miR-15a 表达水平下调，同时证实了过表达 miR-15a 抑制人腹膜间皮细胞 VEGF 的表达，miR-15a 可能通过VEGF 影响腹膜间皮细胞转分化。本项目验证了上调 miR-15a 表达水平改善高糖诱导的人腹膜间皮细胞转分化。综上，本课题组从分子水平验证了 miR-15a 通过 VEGF 参与高糖环境下人腹膜间皮细胞转分化的过程，为腹膜透析相关腹膜纤维化的发生机制提供理论依据。 该研究的开展将进一步加强预防血管新生、腹膜纤维化及炎症等腹膜变化方面的研究，对VEGF参与UFF发生的机制将有更全面、深入的理解，为临床提供可以应用的有效药物，从而为提高PD治疗水平，改善ESRD患者的生活质量提供实验依据。