Institute for Bio-Medical Convergence, College of Medicine, Catholic Kwandong University, Gangneung, Gangwon-do, 25601, Republic of Korea.
Severance Integrative Research Institute for Cerebral and Cardiovascular Diseases, Yonsei University College of Medicine, Seoul, Republic of Korea.
Inflamm Res. 2018 Aug;67(8):691-701. doi: 10.1007/s00011-018-1160-9. Epub 2018 May 23.
The receptor for advanced glycation endproducts (RAGE) is an innate immunity receptor that has been implicated in the pathogenesis of atherosclerotic cardiovascular disease. However, the possibility that RAGE-mediated signaling is involved in angiotensin II (Ang II)-induced cardiac left ventricular hypertrophy has yet to be investigated. We therefore determined whether RAGE has a role in regulating pathological cardiac hypertrophy.
Protein abundance was estimated using Western blotting and intracellular ROS level and phospho-p65 were detected using fluorescence microscopy. Enzyme-linked immunosorbent assay was used to detect HMGB1 and IL-1β. All in vitro experiments were performed using H9C2 cells.
To induce cardiomyocyte hypertrophy, 300 nM Ang II was treated for 48 h and 2 µg/ml sRAGE was treated 1 h prior to addition of Ang II.
sRAGE attenuated Ang II-induced cardiomyocyte hypertrophy by downregulating RAGE and angiotensin II type 1 receptor expression. Secretion levels of high motility group box 1 and interleukin-1β, estimated from a cell culture medium, were significantly reduced by sRAGE. Activated PKCs and ERK1/2, important signals in left ventricular hypertrophy (LVH) development, were downregulated by sRAGE treatment. Furthermore, we found that nuclear factor-κB and NOD-like receptor protein 3 (NLRP3) were associated with RAGE-mediated cardiomyocyte hypertrophy.
In the context of these results, we conclude that RAGE induces cardiac hypertrophy through the activation of the PKCs-ERK1/2 and NF-κB-NLRP3-IL1β signaling pathway, and suggest that RAGE-NLRP3 may be an important mediator of Ang II-induced cardiomyocyte hypertrophy. In addition, we determined that inhibition of RAGE activation with soluble RAGE (sRAGE) has a protective effect on Ang II-induced cardiomyocyte hypertrophy.
晚期糖基化终产物受体（RAGE）是一种先天免疫受体，已被认为与动脉粥样硬化性心血管疾病的发病机制有关。然而，RAGE 介导的信号转导是否参与血管紧张素 II（Ang II）诱导的心肌左心室肥厚尚未得到研究。因此，我们确定 RAGE 是否在调节病理性心肌肥厚中起作用。
使用 Western 印迹法估计蛋白质丰度，使用荧光显微镜检测细胞内 ROS 水平和磷酸化 p65。酶联免疫吸附试验用于检测 HMGB1 和 IL-1β。所有体外实验均使用 H9C2 细胞进行。
为了诱导心肌细胞肥大，用 300 nM Ang II 处理 48 h，并用 2 µg/ml sRAGE 处理 1 h，然后加入 Ang II。
sRAGE 通过下调 RAGE 和血管紧张素 II 型 1 受体的表达来减弱 Ang II 诱导的心肌细胞肥大。sRAGE 显著降低了细胞培养液中高迁移率族盒 1 和白细胞介素 1β的分泌水平。sRAGE 处理后，PKC 和 ERK1/2 的激活，这是左心室肥厚（LVH）发展的重要信号，被下调。此外，我们发现核因子-κB 和 NOD 样受体蛋白 3（NLRP3）与 RAGE 介导的心肌细胞肥大有关。
在这些结果的背景下，我们得出结论，RAGE 通过激活 PKC-ERK1/2 和 NF-κB-NLRP3-IL1β 信号通路诱导心肌肥大，并表明 RAGE-NLRP3 可能是 Ang II 诱导的心肌细胞肥大的重要介质。此外，我们确定用可溶性 RAGE（sRAGE）抑制 RAGE 激活对 Ang II 诱导的心肌细胞肥大具有保护作用。
