MicroRNA-200a/200b Modulate High Glucose-Induced Endothelial Inflammation by Targeting O-linked N-Acetylglucosamine...

Area of Science:

• Molecular Biology
• Endocrinology
• Cardiovascular Research

Background:

• Elevated O-linked N-acetylglucosamine (O-GlcNAc) modification, mediated by O-GlcNAc transferase (OGT), is linked to diabetic complications.
• Oxidative stress exacerbates endothelial inflammation in diabetes, and microRNA-200 (miR-200) family members are sensitive to oxidative stress.

Purpose of the Study:

• To investigate if miR-200a and miR-200b regulate high-glucose (HG)-induced OGT expression in human aortic endothelial cells (HAECs).
• To determine if miR-200a/200b downregulate OGT to mitigate HG-induced endothelial inflammation.

Main Methods:

• Human aortic endothelial cells (HAECs) were exposed to high glucose (HG).
• Techniques included real-time PCR, western blotting, adhesion assays, bioinformatics, luciferase reporter assays, and siRNA-mediated OGT knockdown.
• In vivo validation was performed in db/db diabetic mice using miR-200a/200b mimic injections.

Main Results:

• HG increased OGT expression, protein O-GlcNAcylation, and inflammatory markers (ICAM-1, VCAM-1, E-selectin) in HAECs.
• miR-200a/200b levels decreased under HG conditions, and mimics of miR-200a/200b suppressed HG-induced OGT upregulation and inflammation.
• OGT depletion reduced HG-induced inflammation, and miR-200a/200b mimics downregulated OGT and ICAM-1 in diabetic mouse aortas.

Conclusions:

• miR-200a/200b modulate HG-induced endothelial inflammation by regulating OGT-mediated protein O-GlcNAcylation.
• These findings highlight a potential therapeutic role for miR-200a/200b in managing vascular complications associated with diabetes.