Fetal PGC-1α overexpression programs adult pancreatic β-cell dysfunction

Area of Science:

• Endocrinology
• Developmental Biology
• Metabolic Diseases

Background:

• Adult type 2 diabetes is characterized by β-cell dysfunction.
• Adverse fetal environments can program this dysfunction.
• Fetal glucocorticoids (GCs) inhibit β-cell development.

Purpose of the Study:

• Investigate the molecular mechanisms by which fetal GCs program adult β-cell dysfunction.
• Elucidate the role of peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) in this process.

Main Methods:

• Studied the effect of GCs on PGC-1α expression in β-cells.
• Examined PGC-1α's regulation of β-cell development and function genes, including pancreatic duodenal homeobox 1 (Pdx1).
• Generated mice with inducible β-cell PGC-1α overexpression to assess its impact on adult β-cell function.

Main Results:

• GCs stimulate PGC-1α expression, which represses genes crucial for β-cell development and function.
• PGC-1α inhibits Pdx1 expression via a glucocorticoid receptor (GR)/PGC-1α complex binding to the Pdx1 promoter.
• Mice with fetal PGC-1α overexpression exhibited impaired glucose tolerance, reduced insulin secretion, and decreased β-cell mass in adulthood.

Conclusions:

• The GR and PGC-1α mediate the fetal programming of adult β-cell function.
• This programming occurs through the inhibition of Pdx1 expression during fetal development.