Exenatide can inhibit calcification of human VSMCs through the NF-kappaB/RANKL signaling pathway.

Arterial calcification is an important pathological change of diabetic vascular complication. Osteoblastic differentiation of vascular smooth muscle cells (VSMCs) plays an important cytopathologic role in arterial calcification. The glucagon-like peptide-1 receptor agonists (GLP-1RA), a novel type of antidiabetic drugs, exert cardioprotective effects through the GLP-1 receptor (GLP-1R). However, the question of whether or not GLP-1RA regulates osteoblastic differentiation and calcification of VSMCs has not been answered, and the associated molecular mechanisms have not been examined. Calcifying VSMCs (CVSMCs) were isolated from cultured human arterial smooth muscle cells through limiting dilution and cloning. The extent of matrix mineralization was measured by Alizarin Red S staining. Protein expression and phosphorylation were detected by Western blot. Gene expression of receptor activator of nuclear factor-κB ligand (RANKL) was silenced by small interference RNA (siRNA). Exenatide, an agonist of GLP-1 receptor, attenuated β-glycerol phosphate (β-GP) induced osteoblastic differentiation and calcification of human CVSMCs in a dose- and time-dependent manner. RANKL siRNA also inhibited osteoblastic differentiation and calcification. Exenatide decreased the expression of RANKL in a dose-dependent manner. 1,25 vitD3 (an activator of RANKL) upregulated, whereas BAY11-7082 (an inhibitor of NF-κB) downregulated RANKL, alkaline phosphatase (ALP), osteocalcin (OC), and core binding factor α1 (Runx2) protein levels and reduced mineralization in human CVSMCs. Exenatide decreased p-NF-κB and increased p-AMPKα levels in human CVSMCs 48 h after treatment. Significant decrease in p-NF-κB (p-Ser276, p-Ser536) level was observed in cells treated with exenatide or exenatide + BAY11-7082. GLP-1RA exenatide can inhibit human VSMCs calcification through NF-κB/RANKL signaling.

动脉钙化是糖尿病血管并发症的一种重要病理改变。血管平滑肌细胞（VSMCs）的成骨分化在动脉钙化中起着重要的细胞病理作用。胰高血糖素样肽 - 1受体激动剂（GLP - 1RA）是一种新型的抗糖尿病药物，通过胰高血糖素样肽 - 1受体（GLP - 1R）发挥心脏保护作用。然而，GLP - 1RA是否调节VSMCs的成骨分化和钙化这一问题尚未得到解答，相关的分子机制也未得到研究。 钙化的血管平滑肌细胞（CVSMCs）是通过有限稀释和克隆从培养的人动脉平滑肌细胞中分离出来的。基质矿化程度通过茜素红S染色进行测量。蛋白质表达和磷酸化通过蛋白质印迹法检测。核因子 - κB受体激活剂配体（RANKL）的基因表达通过小干扰RNA（siRNA）沉默。 艾塞那肽，一种GLP - 1受体激动剂，以剂量和时间依赖的方式减弱β - 甘油磷酸（β - GP）诱导的人CVSMCs的成骨分化和钙化。RANKL siRNA也抑制成骨分化和钙化。艾塞那肽以剂量依赖的方式降低RANKL的表达。1,25 - 二羟维生素D3（RANKL的激活剂）上调，而BAY11 - 7082（核因子 - κB的抑制剂）下调人CVSMCs中RANKL、碱性磷酸酶（ALP）、骨钙素（OC）和核心结合因子α1（Runx2）的蛋白质水平，并减少矿化。艾塞那肽在处理48小时后降低人CVSMCs中的p - NF - κB并增加p - AMPKα水平。在使用艾塞那肽或艾塞那肽 + BAY11 - 7082处理的细胞中观察到p - NF - κB（p - Ser276，p - Ser536）水平显著降低。 GLP - 1RA艾塞那肽可通过NF - κB / RANKL信号通路抑制人VSMCs钙化。