Integrator complex subunit 6 promotes hepatocellular steatosis via β-catenin-PPARγ axis

Area of Science:

• Hepatology
• Molecular Biology
• Cell Biology

Background:

• Hepatic adipogenesis shares mechanisms with adipocyte differentiation, involving PPARγ and adipose-specific genes.
• Integrator complex subunit 6 (INTS6) is known to be essential for adipocyte differentiation.
• Metabolic dysfunction-associated steatohepatitis (MASH) is a growing health concern with limited therapeutic options.

Purpose of the Study:

• To investigate the expression of INTS6 in the context of hepatic steatosis.
• To elucidate the role of INTS6 in the progression of MASH.
• To explore INTS6 as a potential therapeutic target for MASH.

Main Methods:

• Examined INTS6 and PPARγ expression in a mouse model of steatohepatitis and human MASH liver biopsies.
• Utilized an in vitro model of hepatocellular steatosis using free fatty acid-treated hepatocytes.
• Performed INTS6 knockdown using siRNA to assess its impact on lipid accumulation and gene expression.

Main Results:

• Hepatic INTS6 and PPARγ were upregulated in a steatohepatitis mouse model and in MASH patients.
• A strong positive correlation was observed between INTS6 and PPARγ mRNA levels in human liver samples.
• INTS6 knockdown significantly reduced hepatic steatosis and lipid accumulation in vitro by modulating the β-catenin-PPARγ axis.

Conclusions:

• INTS6 expression is closely linked to PPARγ and correlates with hepatic steatosis severity.
• INTS6 plays a crucial role in promoting hepatocyte steatosis progression.
• Targeting INTS6 may offer a novel therapeutic strategy for managing MASH.