Xie Caidie, Chen Cheng, Wu Lin, Xiong Yiqing, Xing Changying, Mao Huijuan
Department of Nephrology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China; Department of Nephrology, Nanjing Public Health Medical Center, Nanjing Second Hospital, Nanjing Hospital Affiliated to Nanjing University of Traditional Chinese Medicine, Nanjing, China.
Department of Nephrology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China; Department of Medical Science, Yangzhou Polytechnic College, Yangzhou, China.
Exp Cell Res. 2022 Apr 1;413(1):113051. doi: 10.1016/j.yexcr.2022.113051. Epub 2022 Feb 8.
Vascular calcification (VC) is a strong predictor of cardiovascular mortality and overall mortality in patients with chronic kidney disease (CKD); however, the molecular mechanisms underlying VC have yet to be elucidated. Here, we report the role of the deubiquitinating enzyme BRCC36 in the process of VC in CKD. We established an in vitro VC model of vascular smooth muscle cells (VSMCs) and an adenine-induced CKD mouse model. The expression of BRCC36 was significantly decreased in both the in vivo and in vitro VC models. Alizarin red staining and calcium content assays showed that BRCC36 overexpression reduced calcium deposition in the presence of calcifying medium, while the contractile protein α-smooth muscle actin (α-SMA) was upregulated and phosphorylated β-catenin was downregulated. Cell immunofluorescence showed that BRCC36 overexpression also reduced the expression of phosphorylated β-catenin in the nucleus in the presence of calcifying medium. In addition, coimmunoprecipitation showed that BRCC36 can bind to β-catenin. These results suggest that BRCC36 can interact with β-catenin, the main effector protein of the Wnt/β-catenin pathway, inhibiting the phosphorylation of β-catenin and negatively regulating the cell signalling pathway, thereby inhibiting VC. This may provide new insights into the molecular mechanisms of VC in the context of CKD.
血管钙化（VC）是慢性肾脏病（CKD）患者心血管死亡率和全因死亡率的有力预测指标；然而，VC潜在的分子机制尚未阐明。在此，我们报告去泛素化酶BRCC36在CKD患者VC过程中的作用。我们建立了血管平滑肌细胞（VSMC）的体外VC模型和腺嘌呤诱导的CKD小鼠模型。在体内和体外VC模型中，BRCC36的表达均显著降低。茜素红染色和钙含量测定表明，在存在钙化培养基的情况下，BRCC36过表达减少了钙沉积，同时收缩蛋白α-平滑肌肌动蛋白（α-SMA）上调，磷酸化β-连环蛋白下调。细胞免疫荧光显示，在存在钙化培养基的情况下，BRCC36过表达也降低了细胞核中磷酸化β-连环蛋白的表达。此外，免疫共沉淀表明BRCC36可与β-连环蛋白结合。这些结果表明，BRCC36可与Wnt/β-连环蛋白通路的主要效应蛋白β-连环蛋白相互作用，抑制β-连环蛋白的磷酸化并负向调节细胞信号通路，从而抑制VC。这可能为CKD背景下VC的分子机制提供新的见解。
