Leptin up-regulates microRNA-27a/b-3p level in hepatic stellate cells

Area of Science:

• Hepatology
• Molecular Biology
• Endocrinology

Background:

• Obesity and hyperleptinemia are linked to liver fibrogenesis.
• Leptin, a hormone from adipocytes, promotes liver fibrosis.
• Sterol regulatory element binding protein-1c (SREBP1c) inhibits hepatic stellate cell (HSC) activation, a key fibrogenesis step.

Purpose of the Study:

• To investigate the role of microRNAs (miRNAs) in leptin-induced liver fibrogenesis.
• To elucidate the mechanism by which leptin regulates SREBP1c expression in HSCs.
• To determine the involvement of miR-27a/b-3p in leptin-associated liver fibrosis.

Main Methods:

• Investigated leptin's effect on miR-27a/b-3p levels in HSCs in vitro and in vivo.
• Analyzed the impact of miR-27a/b-3p on SREBP1c, liver x receptor α (LXRα), α-smooth muscle actin (α-SMA), and α1(I)collagen expression.
• Examined the regulatory relationship between miR-27a/b-3p and SREBP1c/LXRα mRNA 3'-untranslated regions.

Main Results:

• Leptin up-regulated miR-27a/b-3p levels in HSCs.
• miR-27a/b-3p reduced SREBP1c and LXRα levels, while increasing α-SMA and α1(I)collagen.
• miR-27a/b-3p was implicated in leptin-induced HSC activation and liver fibrosis in vivo.

Conclusions:

• Leptin promotes liver fibrogenesis via up-regulation of miR-27a/b-3p in HSCs.
• miR-27a/b-3p contributes to liver fibrosis by suppressing SREBP1c and promoting HSC activation.
• These findings offer insights into leptin's role in liver fibrosis in obese patients.