T2DM-elicited oxidative stress represses MTA3 expression in mouse Leydig cells

Area of Science:

• Endocrinology
• Molecular Biology
• Reproductive Biology

Background:

• Metastasis-associated protein 3 (MTA3) is a coregulator in cancer and physiological processes.
• MTA3 is predominantly expressed in Leydig cells (LCs) and modulates testicular steroidogenesis.
• Insulin influences MTA3 expression, suggesting endocrine roles in testicular function.

Purpose of the Study:

• To investigate the mechanism by which type 2 diabetes mellitus (T2DM) affects MTA3 expression in LCs.
• To explore the role of oxidative stress and NR4A1 in T2DM-induced MTA3 downregulation.
• To assess the therapeutic potential of restoring MTA3 expression for male infertility in T2DM.

Main Methods:

• Primary mouse Leydig cell culture and in vivo studies in diabetic mice.
• Biochemical assays to measure MTA3 expression, oxidative stress markers, and NR4A1 activity.
• In vivo gene transfer using lentiviral plasmids to restore MTA3 expression.

Main Results:

• T2DM increased testicular oxidative stress and decreased MTA3 expression in LCs.
• Melatonin ameliorated oxidative stress and restored MTA3 expression without altering insulin levels.
• Oxidative stress suppressed MTA3 via NR4A1 repression; NR4A1 overexpression rescued MTA3 expression.
• In vivo MTA3 replenishment partially restored steroidogenesis and improved fertility in diabetic mice.

Conclusions:

• Oxidative stress-impaired NR4A1-driven transactivation of MTA3 is a key mechanism linking T2DM, hyperinsulinemia, and male infertility.
• Targeting MTA3 represents a potential therapeutic strategy for T2DM-associated male reproductive dysfunction.