Tao Hui, Zhang Meng, Yang Jing-Jing, Shi Kai-Hu
Department of Cardiothoracic Surgery, The Second Hospital of Anhui Medical University, Hefei 230601, China; Cardiovascular Research Center, Anhui Medical University, Hefei 230601, China.
Department of Pharmacology, The Second Hospital of Anhui Medical University, Hefei 230601, China.
Heart Lung Circ. 2018 Jan;27(1):104-113. doi: 10.1016/j.hlc.2016.01.022. Epub 2017 Mar 12.
microRNAs (miRs) have been reported to regulate cell biological functions. To explore the underlying mechanism of miR-21 involvement in patients with atrial fibrosis and atrial fibrillation (AF).
In total, 49 patients (24 AF, sinus rhythm 25) aged 33-68 years old, including heart valve replacement surgery and cardiac catheterisation. The pathological changes and collagen depositions was analysed by Masson's Trichrome Staining. miR-21, TGF-β1, Smad2, p-Smad2, WWP-1, collagen I and collagen III expression were analysed by Western blotting, qRT-PCR, miR one step qRT-PCR, respectively. Treatment human cardiac fibroblasts with TGF-β1, qRT-PCR and Western blotting to find changes in miR-21, Smad2 and WWP-1 levels. Transfected human cardiac fibroblasts with miR-21 mimic and miR-21 inhibitor. Finally, cell proliferation ability was assessed by the MTT assay and flow cytometry.
Compared to sinus rhythm (SR) group, the collagen volume fraction was significantly increased in AF patients. The levels of the TGF-β1, collagen I and collagen III were significantly elevated in AF group. In AF patients, the expression of miR-21 was increased, while the expression of WWP-1 was decreased. Transfected cardiac fibroblasts with miR-21 mimic increased miR-21 expression and decreased WWP-1 expression, whereas miR-21 inhibitor causes the opposite effects. Additionally, we demonstrated that knockdown miR-21 targeted up-regulation of WWP-1 may suppress cardiac fibroblasts proliferation.
These indicated that miR-21 inhibits cardiac fibroblasts proliferation by inactivating the TGF-β1/Smad2 signaling pathway via up-regulation of WWP-1.
据报道,微小RNA(miR)可调节细胞生物学功能。旨在探究miR-21参与心房纤维化和心房颤动(AF)患者发病的潜在机制。
共纳入49例年龄在33至68岁之间的患者(24例AF患者,25例窦性心律患者),包括心脏瓣膜置换手术和心导管检查。通过Masson三色染色分析病理变化和胶原沉积。分别采用蛋白质免疫印迹法、qRT-PCR、miR一步法qRT-PCR分析miR-21、转化生长因子-β1(TGF-β1)、Smad2、磷酸化Smad2(p-Smad2)、WWP-1、I型胶原和III型胶原的表达。用TGF-β1处理人心脏成纤维细胞,采用qRT-PCR和蛋白质免疫印迹法检测miR-21、Smad2和WWP-1水平的变化。用miR-21模拟物和miR-21抑制剂转染人心脏成纤维细胞。最后,通过MTT法和流式细胞术评估细胞增殖能力。
与窦性心律(SR)组相比,AF患者的胶原体积分数显著增加。AF组中TGF-β1、I型胶原和III型胶原的水平显著升高。AF患者中,miR-21的表达增加,而WWP-1的表达降低。用miR-21模拟物转染心脏成纤维细胞可增加miR-21表达并降低WWP-1表达,而miR-21抑制剂则产生相反的效果。此外,我们证明敲低miR-21靶向上调WWP-1可能抑制心脏成纤维细胞增殖。
这些结果表明,miR-21通过上调WWP-1使TGF-β1/Smad2信号通路失活,从而抑制心脏成纤维细胞增殖。