Drp1-mediated mitochondrial fission promotes renal fibroblast activation and fibrogenesis
Drp1-mediated mitochondrial fission promotes renal fibroblast activation and fibrogenesis
复制标题
Drp1 介导的线粒体分裂促进肾成纤维细胞活化和纤维化。
DOI：
10.1038/s41419-019-2218-5
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发表时间：
2020-01-16
影响因子：
9
通讯作者：
Mao, Haiping
中科院分区：
文献类型：
--
作者：
Wang, Yating;Lu, Miaoqing;Mao, Haiping
过度的线粒体分裂在某些癌症和器官纤维化中充当促增殖标志物;其在肾成纤维细胞活化和纤维形成中的潜在作用从未被研究过。在这里，我们发现在人类和小鼠中，纤维化的肾成纤维细胞中的线粒体碎片比非纤维化的肾成纤维细胞中的线粒体碎片更明显。在梗阻性肾病小鼠模型中，纤维化肾脏中Drp 1丝氨酸616磷酸化（p-Drp 1 S616）和H3 K27乙酰化（H3 K27 ac）增加; mdivi-1对线粒体分裂的药理学抑制显著降低了H3 K27 ac水平、成纤维细胞蓄积和间质纤维化。此外，mdivi-1治疗能够减弱已建立的肾纤维化。在培养的肾间质成纤维细胞中，使用药理学抑制剂或siRNA靶向Drp 1抑制TGF-β 1引起的细胞活化和增殖，这通过抑制α-平滑肌肌动蛋白（α-SMA）和胶原蛋白I的表达以及减少DNA合成来证明。相反，Drp 1缺失增强细胞凋亡，沿着线粒体碎片减少、线粒体ROS升高和TGF-β 1刺激后糖酵解转变。在Drp 1缺失的成纤维细胞中，野生型Drp 1而不是Drp 1 S616 A突变体的重新表达恢复了TGF-β诱导的Drp 1磷酸化、H3 K27 ac和细胞活化的减少。此外，TGF-β 1处理增加了α-SMA和PCNA启动子处H3 K27 ac的富集，这在与空载体或Drp 1 S616 A共转染的Drp 1敲低成纤维细胞中逆转，但野生型Drp 1未逆转。总的来说，我们的研究结果表明，抑制p-Drp 1 S616介导的线粒体分裂减弱成纤维细胞的活化和增殖在肾纤维化通过表观遗传调控的纤维化相关基因转录，并可能作为一个治疗目标，延缓慢性肾脏疾病的进展。
Excessive mitochondrial fission acts as a pro-proliferative marker in some cancers and organ fibrosis; its potential role in renal fibroblast activation and fibrogenesis has never been investigated. Here, we showed more pronounced fragmented mitochondria in fibrotic than in non-fibrotic renal fibroblast in humans and mice. In a mouse model of obstructive nephropathy, phosphorylation of Drp1 at serine 616 (p-Drp1S616) and acetylation of H3K27(H3K27ac) was increased in fibrotic kidneys; pharmacological inhibition of mitochondrial fission by mdivi-1 substantially reduced H3K27ac levels, fibroblasts accumulation, and interstitial fibrosis. Moreover, mdivi-1 treatment was able to attenuate the established renal fibrosis. In cultured renal interstitial fibroblasts, targeting Drp1 using pharmacological inhibitor or siRNA suppressed TGF-beta 1-elicited cell activation and proliferation, as evidenced by inhibiting expression of alpha-smooth muscle actin (alpha-SMA) and collagen I, as well as by reducing DNA synthesis. In contrast, Drp1 deletion enhanced cell apoptosis, along with decreased mitochondrial fragmentation, mtROS elevation, and glycolytic shift upon TGF-beta 1 stimulation. In Drp1 deletion fibroblasts, re-expression of wild-type Drp1 rather than Drp1S616A mutant restores the reduction of TGF-beta-induced-Drp1 phosphorylation, H3K27ac, and cell activation. Moreover, TGF-beta 1 treatment increased the enrichment of H3K27ac at the promoters of alpha-SMA and PCNA, which was reversed in Drp1-knockdown fibroblasts co-transfected with empty vector or Drp1S616A, but not wild-type Drp1. Collectively, our results imply that inhibiting p-Drp1S616-mediated mitochondrial fission attenuates fibroblast activation and proliferation in renal fibrosis through epigenetic regulation of fibrosis-related genes transcription and may serve as a therapeutic target for retarding progression of chronic kidney disease.