The Impact of miR-34a on Endothelial Cell Viability and Apoptosis in Ischemic Stroke: Unraveling the MTHFR -Homocysteine Pathway

• Published in: Clinical and investigative medicine Vol. 47; no. 3; pp. 27 - 37
• Main Authors: Liang, Lina, Yi, Xueli, Wang, Chunfang, Su, Li, Wei, Guijiang
• Format: Journal Article
• Language: English
• Published: Canada 01.09.2024
• Subjects: Aged; Apoptosis; Cell Survival; Female; Homocysteine - blood; Human Umbilical Vein Endothelial Cells - metabolism; Humans; Ischemic Stroke - blood; Ischemic Stroke - metabolism; Ischemic Stroke - pathology; Male; Methylenetetrahydrofolate Reductase (NADPH2) - genetics; Methylenetetrahydrofolate Reductase (NADPH2) - metabolism; MicroRNAs - genetics; MicroRNAs - metabolism; Middle Aged; homocysteine; MTHFR; miR-34a; ischemic stroke; human umbilical vein endothelial cells
• ISSN: 1488-2353; 1488-2353
• DOI: 10.3138/cim-2024-2711

Ischemic stroke (IS) is a global health concern, often tied to dyslipidemia and vascular endothelial dysfunction. MicroRNA-34a (miR-34a) was reported to be up-regulated in the blood samples of patients with IS, but the specific role of miR-34a and methylenetetrahydrofolate reductase (MTHFR) in IS remains to be elucidated. We studied 143 subjects: 71 IS patients, and 72 healthy controls. Human umbilical vein endothelial cells (HUVECs) were cultured and transfected with a miR-34a mimic, inhibitor, or negative control. The miR-34a expression in serum and HUVECs was quantified via quantitative reverse transcription polymerase chain reaction (qRT-PCR). Viability and apoptosis of HUVECs were assessed using CCK-8 assay and flow cytometry. The expression levels of bcl-2, bax, cyt-c, cleaved caspase 3, MTHFR, and homocysteine were measured by Western blot or enzyme-linked immunosorbent assay (ELISA). The relationship between miR-34a and MTHFR was verified by luciferase reporter assay. The levels of MTHFR and homocysteine in serum were examined by ELISA. MiR-34a expression was increased in IS patients and inhibited viability of HUVECs while promoting their apoptosis. Overexpression of miR-34a up-regulated pro-apoptotic proteins (bax, cyt-c and cleaved caspase 3) and down-regulated anti-apoptotic protein bcl-2 in HUVECs. MTHFR was identified as the downstream target of miR-34a and its expression was reduced by miR-34a overexpression, while homocysteine levels increased. Consistently, MTHFR levels were lower and homocysteine levels were higher in IS patients compared with controls. Our results suggest that up-regulated miR-34a plays a role in the pathogenesis of IS, potentially through inhibiting MTHFR expression and increasing homocysteine in endothelial cells. Therefore, miR-34a might be a therapeutic target for IS.