Department of Cardiology, Beijing Friendship Hospital, Capital Medical University, China.
Department of Cardiology, Beijing Friendship Hospital, Capital Medical University, China.
Peptides. 2019 Feb;112:125-132. doi: 10.1016/j.peptides.2018.11.008. Epub 2018 Dec 1.
Vascular smooth muscle cell (VSMC) phenotype transition is involved in diabetes-associated cardiovascular diseases. The mechanism of VSMCs phenotypic transition in T2DM was still unclear. Rat coronary artery SMCs were pretreated with liraglutide alone, liraglutide and H89(a PKA inhibitor), neutralizing anti-RAGE antibody or the antioxidant pyrrolidine dithiocarbamate (PDTC; a nuclear factor-κB (NF-κB) inhibitor), followed by treatment with AGE. The morphological change of the SMCs was observed. We also observed the α-actin positive myofilaments and F-actin distribution in SMC through immunofluorescence microscopy. Smooth muscle myosin heavy chain 11(MYH11), α-smooth muscle actin (α-SMA) and myocardin protein expression were detected by Western blot. Collagen I productionS and NF-κB nuclear translocation were also investigated. AGEs induced a transition of SMC from contractile to synthetic phenotype, which was associated with decreased SMC differentiation markers such as α-SMA, MYH11 and myocardin by activating the NF-κB pathway. AGE also increased collagen I production and secretion by SMCs. Liraglutide inhibited AGEs induced SM phenotypic transition and down-regulation of α-SMA, MYH11 and myocardin. Liraglutide also inhibited AGEs induced NF-κB pathway activation and collagen I production. Pretreatment with liraglutide and H89 together did not exhibit this inhibitory effect as mentioned above. Blockade of RAGE in SMCs with neutralizing antibody inhibited AGEs induced phenotypic transition of SMC, and up-regulated α-SMA and MYH11 expression. Liraglutide inhibited AGE induced SMC phenotypic transition, increased SMC contractile markers expression, and decreased collagen production through down-regulation of myocardin, inhibition of NF-κB pathway, and activation of PKA signaling pathway.
血管平滑肌细胞（VSMC）表型转变与糖尿病相关的心血管疾病有关。T2DM 中 VSMC 表型转变的机制尚不清楚。我们用利拉鲁肽、利拉鲁肽+ H89（PKA 抑制剂）、抗 RAGE 中和抗体或抗氧化剂吡咯烷二硫代氨基甲酸盐（PDTC；NF-κB 抑制剂）预处理大鼠冠状动脉平滑肌细胞，然后用 AGE 处理。观察平滑肌细胞的形态变化。我们还通过免疫荧光显微镜观察平滑肌细胞中α-肌动蛋白阳性肌丝和 F-肌动蛋白分布。通过 Western blot 检测平滑肌肌球蛋白重链 11（MYH11）、α-平滑肌肌动蛋白（α-SMA）和心肌调节蛋白的表达。还研究了胶原 I 的产生和 NF-κB 核易位。AGEs 诱导平滑肌细胞从收缩型向合成型表型转变，这与通过激活 NF-κB 通路下调平滑肌细胞分化标志物如α-SMA、MYH11 和心肌调节蛋白有关。AGEs 还增加了平滑肌细胞的胶原 I 产生和分泌。利拉鲁肽抑制 AGEs 诱导的 SM 表型转变和下调α-SMA、MYH11 和心肌调节蛋白。利拉鲁肽还抑制了 AGEs 诱导的 NF-κB 通路激活和胶原 I 产生。用利拉鲁肽和 H89 预处理并没有表现出上述抑制作用。用中和抗体阻断平滑肌细胞中的 RAGE 抑制了 AGEs 诱导的平滑肌细胞表型转变，并上调了α-SMA 和 MYH11 的表达。利拉鲁肽通过下调心肌调节蛋白、抑制 NF-κB 通路和激活 PKA 信号通路，抑制 AGE 诱导的平滑肌细胞表型转变，增加平滑肌细胞收缩标志物的表达，减少胶原产生。
