ABSTRACT
Cardiac microvascular endothelial cells (CMECs) assume a pivotal role in the regulation of blood flow, and their impairment precipitates a spectrum of pathological transformations. Our previous study unveiled a notable mitigation of CMECs dysfunction through the intervention of integrin subunit alpha 5 (ITGA5), a member of the integrin protein family. This study delves into the effect of ITGA5 on the mitochondrial function in CMECs and reveals the regulation pathway. CMECs were stimulated with oxidized low-density lipoprotein (ox-LDL) to mimic coronary artery disease (CAD). The effects of ITGA5 on diverse facets of CMEC behavior, encompassing viability, apoptosis, angiogenesis, oxidative stress, and mitochondrial function, was systematically ascertained. Employing the phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway as a focal point of investigation, the mediation of this pathway was substantiated utilizing the PI3K inhibitor LY294002. ITGA5 overexpression exerted a mitigating influence upon the ox-LDL-induced detriment to CMECs, manifested as increased viability, angiogenesis, mitochondrial function, and diminished apoptosis and oxidative stress. The counteraction of these salubrious effects by the administration of the PI3K inhibitor attests to the engagement of the PI3K/AKT signaling pathway. Overall, this study has discerned that ITGA5 activates the PI3k/Akt signaling pathway to orchestrate mitochondrial function and diminish ox-LDL-induced CMEC dysfunction. Thus, the targeted amelioration of this cellular injury emerges as a strategically pivotal endeavor for the prevention and amelioration of this ailment.
ABSTRACT
BACKGROUND: The complex process of atherosclerosis is thought to begin with endothelial cell dysfunction, and advanced atherosclerosis is the underlying cause of coronary artery disease (CAD). Uncovering the underlying mechanisms of CAD-related endothelial cell injury may contribute to the treatment. MATERIALS AND METHODS: Cardiac microvascular endothelial cells (CMVECs) were treated with oxidised low-density lipoprotein (ox-LDL) to mimic an injury model. The involvement of Talin-1 (TLN1) and integrin alpha 5 (ITGA5) in the proliferation, apoptosis, angiogenesis, inflammatory response, and oxidative stress in CMVECs were assessed. RESULTS: TLN1 overexpression assisted CMVECs in resistance to ox-LDL stimulation, with alleviated cell proliferation and angiogenesis, reduced apoptosis, inflammatory response, and oxidative stress. TLN1 overexpression triggered increased ITGA5, and ITGA5 knockdown reversed the effects of TLN1 overexpression on the abovementioned aspects. Together, TLN1 synergized with ITGA5 to ameliorate the dysfunction in CMVECs. CONCLUSIONS: This finding suggests their probable involvement in CAD, and increasing their levels is beneficial to disease relief.
Subject(s)
Atherosclerosis , Endothelial Cells , Humans , Heart , Integrins , Oxidative Stress , TalinABSTRACT
Atherosclerosis is a major cause of cardiovascular disease, in which vascular smooth muscle cells (VSMCs) proliferation and migration play a vital role. Circular RNAs (circRNAs) have been reported to be correlated with the VSMCs function. Therefore, this study is designed to explore the role and mechanism of circRNA lipase maturation factor 1 (circLMF1) in Human aortic VSMCs (HASMCs). The microarray was used for detecting the expression of circLMF1 in proliferative and quiescent HASMCs. Levels of circLMF1, microRNA-125a-3p (miR-125a-3p), vascular endothelial growth factor A (VEGFA), and fibroblast growth factor 1 (FGF1) were determined by real-time quantitative polymerase chain reaction (RT-qPCR). Cell viability, cell cycle progression, and migration were assessed by Cell Counting Kit-8 (CCK-8), flow cytometry, wound healing, and transwell assays, respectively. Western blot assay determined proliferating cell nuclear antigen (PCNA), Cyclin D1, matrix metalloproteinase (MMP2), osteopontin (OPN), VEGFA, and FGF1 protein levels. The possible interactions between miR-125a-3p and circLMF1, and miR-125a-3p and VEGFA or FGF1 were predicted by circbank or targetscan, and then verified by a dual-luciferase reporter, RNA Immunoprecipitation (RIP), RNA pull-down assays. CircLMF1, VEGFA, and FGF1 were increased, and miR-125a-3p was decreased in platelet-derived growth factor-BB (PDGF-BB)-inducted HASMCs. Functionally, circLMF1 knockdown hindered cell viability, cell cycle progression, and migration in PDGF-BB-treated HASMCs. Mechanically, circLMF1 could regulate VEGFA or FGF1 expression through sponging miR-125a-3p. Our findings revealed that circLMF1 deficiency could inhibit cell viability, cell cycle progression, and migration of PDGF-BB stimulated atherosclerosis model partly through the miR-125a-3p/VEGFA or FGF1 axis, suggesting that targeting circLMF1 can be a feasible therapeutic strategy for atherosclerosis.