Losartan inhibits EGFR transactivation in vascular smooth muscle cells

Authors: MUSTAFA KIRÇA, AKIN YEŞİLKAYA

Abstract: Background/aim: Angiotensin II (Ang II)-induced molecular signaling pathways play a significant role in the progression of cardiovascular diseases, including hypertension and atherosclerosis. In addition to the well-known effects of Ang II, it may activate epidermal growth factor receptor (EGFR) in a process known as transactivation, which contributes to vascular pathologies. The aim of this study was to determine whether losartan could reduce EGFR transactivation induced by Ang II. Additionally, we evaluated the roles of heparin-binding epidermal-like growth factor (HB-EGF) and matrix metalloproteinases (MMPs) in Ang II-induced EGFR transactivation. Materials and methods: Vascular smooth muscle cells were isolated from a rat aorta and grown in primary culture. Ang II-induced EGFR phosphorylation (tyrosine 1068) and ERK1/2 MAPK phosphorylation (threonine 202 and tyrosine 204) were evaluated by western blotting. Results: Ang II induced EGFR phosphorylation through the Ang II type I receptor (P < 0.05). The transactivation process was inhibited by losartan and mediated by HB-EGF and MMPs. Ang II transactivates EGFR in an AT1R-dependent manner. Conclusion: The results of this study show that losartan, a widely used antihypertensive agent, can suppress EGFR phosphorylation (Y1068) upon Ang II stimulation in vascular smooth muscle cells. EGFR inhibition is a candidate therapy for combating cardiovascular diseases such as hypertension and atherosclerosis.

Keywords: Angiotensin II, EGF receptor, losartan, transactivation, extracellular regulated kinase, vascular smooth muscle, cardiovascular disease

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