SETD7 drives diabetic endothelial dysfunction through FBXO45-mediated GPX4 ubiquitylation

Area of Science:

• Endocrinology
• Molecular Biology
• Cardiovascular Research

Background:

• Diabetic vasculopathy is a major complication, with endothelial damage contributing to organ dysfunction.
• The role of SETD7 (histone methyltransferase) in diabetic endothelial dysfunction is not well understood.
• This study investigates SETD7's mechanisms in high glucose-induced endothelial injury.

Purpose of the Study:

• To elucidate the involvement and underlying mechanisms of SETD7 in diabetic endothelial dysfunction.
• To investigate the effects of SETD7 on hyperglycemia-induced vascular injury.
• To assess SETD7's regulation of oxidative stress and lipid peroxidation in endothelial cells.

Main Methods:

• Utilized SETD7 knockout mice and endothelial-specific SETD7 interruption via AAV in db/db mice.
• Assessed effects on Streptozotocin (STZ)-induced hyperglycemia and vascular injury.
• Performed in vitro studies on primary rat aortic endothelial cells (RAECs) under high glucose conditions, manipulating SETD7.

Main Results:

• SETD7 deficiency partially restored vascular function and reduced inflammation in diabetic mouse models.
• SETD7 activation exacerbated oxidative stress and endothelial dysfunction via Glutathione Peroxidase 4 (GPX4)-mediated lipid peroxidation.
• SETD7 deficiency reduced p53 mono-methylation, blocked FBXO45 transcription, inhibiting GPX4 degradation.

Conclusions:

• The SETD7-p53-FBXO45-GPX4 pathway is implicated in high glucose-induced oxidative stress and endothelial dysfunction.
• Targeting this pathway may mitigate hyperglycemia-induced endothelial damage.
• Findings highlight SETD7 as a potential therapeutic target for diabetic vascular complications.