Babaahmadi-Rezaei Hossein, Kheirollah Alireza, Rashidi Mojtaba, Seif Faezeh, Niknam Zahra, Zamanpour Masoumeh
Hyperlipidemia Research Center, Department of Clinical Biochemistry, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
Cellular and Molecular Research Center, Department of Clinical Biochemistry, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
Cell J. 2021 Oct;23(5):510-515. doi: 10.22074/cellj.2021.7392. Epub 2021 Oct 30.
Growth factors [transforming growth factor-β (TGF-β), epidermal growth factor (EGF), endothelin-1 (ET1)] stimulate proteoglycan synthesis resulting in retention and accumulation of low density lipoprotein (LDL) in vessel intima and leading to atherosclerosis development. This study investigated the role of ET-1 on the expression of CHSY1, proteoglycan synthesizing enzyme, through both EGF and TGF-β receptor transactivation in human vascular smooth muscle cells (VSMCs). Also, we explored the involvement of NADPH oxidase (NOX), an important intermediate of redox signaling, in ET-1 transactivated EGF receptor (EGFR) through endothelin receptors.
In this experimental study, phosphorylated ERK1/2 and CHSY1 protein levels in the human VSMCs were measured by Western blot analysis using anti phospho-ERK1/2 (Thr202/Tyr204) and anti CHSY1 antibodies.
ET-1 (100 nM) and EGF (100 ng/ml) stimulated ERK1/2 phosphorylation and inhibited in the presence of bosentan (ET receptor inhibitor), AG1478 (EGFR inhibitor), and DPI (NOX antagonist). Also, ET-1 treatment increased CHSY1 enzyme level; this response was suppressed by bosentan, AG1478, DPI, and SB431542, TGF-β receptor antagonist. This study revealed that ET-1 increases expression of CHSY1 through transactivation of EGF and TGF-β receptors.
Transactivation through the EGF receptor mediated by phospho-ERK1/2 leads to expression of CHSY1 protein. EGF receptor transactivation by ET-1 is shown for the first time, to be dependent on NOX enzymes.
生长因子[转化生长因子-β（TGF-β）、表皮生长因子（EGF）、内皮素-1（ET1）]刺激蛋白聚糖合成，导致低密度脂蛋白（LDL）在血管内膜潴留和积聚，进而引发动脉粥样硬化。本研究通过表皮生长因子受体（EGFR）和转化生长因子-β受体的反式激活，探讨内皮素-1（ET-1）对蛋白聚糖合成酶CHSY1在人血管平滑肌细胞（VSMCs）中表达的作用。此外，我们还通过内皮素受体，探究了氧化还原信号的重要中间体NADPH氧化酶（NOX）在ET-1反式激活表皮生长因子受体（EGFR）中的作用。
在本实验研究中，使用抗磷酸化ERK1/2（Thr202/Tyr204）抗体和抗CHSY1抗体，通过蛋白质印迹分析测定人VSMCs中磷酸化ERK1/2和CHSY1蛋白水平。
ET-1（100 nM）和EGF（100 ng/ml）刺激ERK1/2磷酸化，而在波生坦（ET受体抑制剂）、AG1478（EGFR抑制剂）和二苯基碘（DPI，NOX拮抗剂）存在的情况下这种刺激受到抑制。此外，ET-1处理可增加CHSY1酶水平；波生坦、AG1478、DPI和SB431542（TGF-β受体拮抗剂）可抑制这种反应。本研究表明，ET-1通过表皮生长因子受体和转化生长因子-β受体的反式激活增加CHSY1的表达。
由磷酸化ERK1/2介导的通过表皮生长因子受体的反式激活导致CHSY1蛋白的表达。首次表明ET-1对表皮生长因子受体的反式激活依赖于NOX酶。
