Chen Honglei, Zhang Zhixu, Zhang Li, Wang Junzhi, Zhang Minghui, Zhu Bin
Department of Cardiology, Chengyang People's Hospital, Qingdao, Shandong, China.
Teaching and Research Office of Immunology, Qingdao University, Qingdao, Shandong, China.
Braz J Med Biol Res. 2018;51(6):e6997. doi: 10.1590/1414-431x20186997. Epub 2018 Apr 19.
MicroRNAs (miRNAs) have been reported to be associated with heart valve disease, which can be caused by inflammation. This study aimed to investigate the functional impacts of miR-27a on TNF-α-induced inflammatory injury in human mitral valve interstitial cells (hMVICs). hMVICs were subjected to 40 ng/mL TNF-α for 48 h, before which the expressions of miR-27a and NELL-1 in hMVICs were altered by stable transfection. Trypan blue staining, BrdU incorporation assay, flow cytometry detection, ELISA, and western blot assay were performed to detect cell proliferation, apoptosis, and the release of proinflammatory cytokines. We found that miR-27a was lowly expressed in response to TNF-α exposure in hMVICs. Overexpression of miR-27a rescued hMVICs from TNF-α-induced inflammatory injury, as cell viability and BrdU incorporation were increased, apoptotic cell rate was decreased, Bcl-2 was up-regulated, Bax and cleaved caspase-3/9 were down-regulated, and the release of IL-1β, IL-6, and MMP-9 were reduced. NELL-1 was positively regulated by miR-27a, and NELL-1 up-regulation exhibited protective functions during TNF-α-induced cell damage. Furthermore, miR-27a blocked JNK and Wnt/β-catenin signaling pathways, and the blockage was abolished when NELL-1 was silenced. This study demonstrated that miR-27a overexpression protected hMVICs from TNF-α-induced cell damage, which might be via up-regulation of NELL-1 and thus modulation of JNK and Wnt/β-catenin signaling pathways.
据报道，微小RNA（miRNA）与心脏瓣膜疾病有关，后者可由炎症引起。本研究旨在探讨miR-27a对人二尖瓣间质细胞（hMVICs）中肿瘤坏死因子-α（TNF-α）诱导的炎症损伤的功能影响。hMVICs用40 ng/mL TNF-α处理48小时，在此之前，通过稳定转染改变hMVICs中miR-27a和NELL-1的表达。进行台盼蓝染色、BrdU掺入试验、流式细胞术检测、酶联免疫吸附测定（ELISA）和蛋白质免疫印迹法检测细胞增殖、凋亡及促炎细胞因子的释放。我们发现，在hMVICs中，miR-27a在TNF-α刺激下低表达。miR-27a过表达使hMVICs免受TNF-α诱导的炎症损伤，表现为细胞活力和BrdU掺入增加，凋亡细胞率降低，Bcl-2上调，Bax和裂解的半胱天冬酶-3/9下调，白细胞介素-1β（IL-1β）、白细胞介素-6（IL-6）和基质金属蛋白酶-9（MMP-9）的释放减少。NELL-1受miR-27a正向调控，NELL-1上调在TNF-α诱导的细胞损伤中发挥保护作用。此外，miR-27a阻断JNK和Wnt/β-连环蛋白信号通路，当NELL-1沉默时，这种阻断作用消失。本研究表明，miR-27a过表达可保护hMVICs免受TNF-α诱导的细胞损伤，其机制可能是通过上调NELL-1，进而调节JNK和Wnt/β-连环蛋白信号通路。
