Center of Growth, Metabolism and Aging, Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, State Key Laboratory of Biotherapy, College of Life Sciences, Sichuan University, Chengdu, Sichuan, 610064, China.
Cell Death Dis. 2018 Nov 14;9(11):1133. doi: 10.1038/s41419-018-1178-5.
MicroRNAs are a group of small non-coding RNAs that play key roles in almost every aspect of mammalian cell. In kidney, microRNAs are required for maintaining normal function of renal cells, disruption of which contributes to pathogenesis of renal diseases. In this study, we investigated the potential role of miRNAs as key regulators of podocyte survival by using a primary cell culture model from non-human primates (NHPs). Through microRNA profile comparison in glomeruli from mouse, rat and NHP, miR-27b was found to be among a list of glomeruli-enriched miRNA conserved across species. In NHP primary podocyte culture, significant downregulation of miR-27b was observed during treatment of puromycin aminonucleoside (PAN), a classic nephrotoxin. Overexpression of miR-27b enhanced PAN-induced apoptosis and cytoskeleton destruction in podocytes while its inhibition had a protective effect. Target identification analysis identified Adora2b as a potential direct target of miR-27b. Ectopic expression of miR-27b suppressed both Adora2b mRNA and protein expression, whereas inhibition of miR-27b increased the transcript and protein expression levels of Adora2B. Dual luciferase assay further confirmed Adora2b as a direct target of miR-27b. Furthermore, knockdown of Adora2b by siRNAs enhanced PAN-induced apoptosis, similar to the phenotypes we had observed with miR-27b overexpression. In addition, stimulating the adenosine signaling by an Adora2b agonist, NECA, improved podocyte survival upon PAN treatment. Taken together, our data identified a novel role of miR-27b-adora2b axis in primary podocyte survival upon injury and suggested a critical role of adenosine signaling pathway in podocyte protection.
miRNAs 是一组小的非编码 RNA，在哺乳动物细胞的几乎所有方面都发挥着关键作用。在肾脏中，miRNAs 对于维持肾细胞的正常功能是必需的，其功能紊乱导致肾脏疾病的发病机制。在这项研究中，我们通过使用来自非人灵长类动物（NHP）的原代细胞培养模型，研究了 miRNAs 作为足细胞存活关键调节剂的潜在作用。通过比较小鼠、大鼠和 NHP 肾小球中的 microRNA 谱，发现 miR-27b 是物种间肾小球富集 miRNA 的列表之一。在 NHP 原代足细胞培养中，在用嘌呤霉素氨基核苷（PAN）处理时观察到 miR-27b 的显著下调，PAN 是一种经典的肾毒素。miR-27b 的过表达增强了 PAN 诱导的足细胞凋亡和细胞骨架破坏，而其抑制则具有保护作用。靶标鉴定分析鉴定出 Adora2b 是 miR-27b 的潜在直接靶标。miR-27b 的异位表达抑制了 Adora2b mRNA 和蛋白表达，而 miR-27b 的抑制增加了 Adora2B 的转录和蛋白表达水平。双荧光素酶报告基因实验进一步证实了 Adora2b 是 miR-27b 的直接靶标。此外，通过 siRNAs 敲低 Adora2b 增强了 PAN 诱导的凋亡，类似于我们观察到的 miR-27b 过表达的表型。此外，通过 Adora2b 激动剂 NECA 刺激腺苷信号通路，可改善 PAN 处理时足细胞的存活。总之，我们的数据确定了 miR-27b-adora2b 轴在原代足细胞损伤后存活中的新作用，并表明腺苷信号通路在足细胞保护中的关键作用。
