Recent studies reported that advanced glycation end products (AGEs) and endothelial-to-mesenchymal transition (EndMT) were involved in the calcific aortic valve disease (CAVD). However, the roles of AGEs in EndMT in the development of CAVD have not been elucidated. In this study, six-week-old male Apoe^−/− mice were divided into four groups based on the following feeding periods: 0, 2, 4, and 6 months. The latter three groups were further divided into three subgroups corresponding to the following diet treatments: normal diet, high-fat diet + normal saline injection, and high-fat diet + aminoguanidine injection. Weight gain was monitored weekly. Finally, heart echocardiographic assessments were performed, and serum lipid levels, the protein expression and the histological changes in the aortic valves were determined. Results showed that the AGE inhibitor aminoguanidine alleviated the transaortic valve velocity and decreased the total cholesterol and low-density lipoprotein cholesterol levels. Calcification and carboxymethyl-lysine deposition were firstly detected around the aortic valve surfaces, whereas aminoguanidine injection attenuated their accumulation. In the early stage, HFD-activated AGEs-RAGE signaling resulted in the alpha-smooth muscle actin (α-SMA) upregulation and the vascular endothelium cadherin (VE-cadherin) downregulation on the valve endothelial layer. The activation resulted in early the transforming growth factor-β1 (TGF-β1) and the alkaline phosphatase (ALP) upregulation, and simultaneously reduced the bone morphogenetic protein receptor type II (BMPR2) expression. However, aminoguanidine restricted these proteins changes by inhibiting the interaction of AGEs and RAGE. In addition, immunofluorescence images showed obvious double-positive staining of ALP and α-SMA on the valve surfaces, revealing the contribution of EndMT to the early calcification. Therefore, this study demonstrates that activation of the AGEs-RAGE axis induced EndMT, promoting the progression of the aortic valve calcification in the initial stage via the counteraction of BMPR2 and TGF-β1 signaling.

最近的研究报道，晚期糖化终末产物（AGEs）和内皮向间充质转化（EndMT）参与了钙化主动脉瓣疾病（CAVD）。但是，尚未阐明AGEs在EndMT中对CAVD的作用。在这项研究中，六周大的男性Apoe ^-/-根据以下喂养时间将小鼠分为四组：0、2、4和6个月。后三组进一步分为三个亚组，分别对应以下饮食治疗：正常饮食，高脂饮食+生理盐水注射和高脂饮食+氨基胍注射。每周监测体重增加。最后，进行心脏超声心动图评估，并测定血脂水平，蛋白表达和主动脉瓣组织改变。结果表明，AGE抑制剂氨基胍可减轻主动脉瓣速度并降低总胆固醇和低密度脂蛋白胆固醇水平。首先在主动脉瓣表面周围发现钙化和羧甲基赖氨酸沉积，而氨基胍注射减弱了它们的积累。在早期阶段，HFD激活的AGEs-RAGE信号导致瓣膜内皮层上的α平滑肌肌动蛋白（α-SMA）上调和血管内皮钙粘蛋白（VE-cadherin）下调。激活导致早期转化生长因子-β1（TGF-β1）和碱性磷酸酶（ALP）上调，同时降低了II型骨形态发生蛋白受体（BMPR2）的表达。但是，氨基胍通过抑制AGEs和RAGE的相互作用限制了这些蛋白质的变化。此外，免疫荧光图像显示了瓣膜表面ALP和α-SMA的明显双阳性染色，表明EndMT对早期钙化的贡献。因此，