miR-10a/b-5p-NCOR2 Regulates Insulin-Resistant Diabetes in Female Mice

Area of Science:

• Endocrinology and Metabolism
• Molecular Biology
• Genetics

Background:

• Biological sex and hormonal status significantly influence type 2 diabetes (T2D) pathogenesis.
• Estrogen deficiency is linked to T2D susceptibility in females, but underlying mechanisms are unclear.
• Previous studies identified a diet-induced T2D pathway (miR-10b-5p/KLF11/KIT) in males, but not females, suggesting hormonal protection.

Purpose of the Study:

• To elucidate the molecular mechanisms of hormonal protection against T2D in estrogen-deficient female mice.
• To investigate the role of the miR-10a/b-5p/NCOR2 axis in insulin resistance.
• To explore the therapeutic potential of miR-10a/b-5p in managing T2D in females.

Main Methods:

• Utilized ovariectomized, estrogen-deficient female mice fed a high-fat, high-sucrose diet (HFHSD) to induce T2D.
• Analyzed molecular changes in insulin (INS), insulin receptor (INSR), and protein kinase B (AKT) pathways.
• Investigated the miR-10a/b-5p/NCOR2 axis and assessed the effects of miR-10a/b-5p and β-estradiol treatments.
• Correlated murine findings with plasma samples from female T2D patients.

Main Results:

• Estrogen deficiency rapidly precipitated T2D in female mice, unlike controls on HFHSD alone.
• Estrogen-deficient T2D mice showed upregulated INS and downregulated INSR and AKT, indicating insulin resistance.
• These dysregulations were mediated by the miR-10a/b-5p/NCOR2 axis.
• miR-10a/b-5p restoration and β-estradiol treatment alleviated hyperglycemia.
• Female T2D patients exhibited reduced miR-10a/b-5p, estrogen, and INSR, with increased insulin levels.

Conclusions:

• Estrogen confers protection against insulin-resistant T2D in females via the miR-10a/b-5p/NCOR2 pathway.
• Reduced miR-10a/b-5p levels are implicated in T2D pathogenesis in estrogen-deficient females.
• Restoration of miR-10a/b-5p represents a potential therapeutic strategy for female T2D management.