Adipocyte-specific deletion of gp130 prevents ketogenic diet-induced hepatic steatosis.

Abstract

Background: Metabolic dysfunction-associated steatotic liver disease (MASLD), the hepatic manifestation of obesity and type 2 diabetes, can progress to metabolic dysfunction-associated steatohepatitis and fibrosis. MASLD is characterized by elevated hepatic lipid accumulation (steatosis) and insulin resistance. The ketogenic diet (KD), a high-fat, low-carbohydrate diet, induces hepatic insulin resistance and steatosis in animal models through unknown mechanisms.

Methods and results: Herein, we investigated the mechanisms behind KD-induced metabolic dysfunction-associated steatohepatitis and fibrosis at thermoneutrality, identifying upregulated inflammatory and lipogenic pathways, including Il-6, Tnf, Mapk13, Lpl, and Pparg. Given the substantial increase in IL-6 during MASLD progression, we investigated IL-6-gp130 signaling using liver- and adipocyte-specific knockout mice. Liver-specific gp130 deletion failed to prevent KD-induced hepatic steatosis and glucose intolerance. In contrast, adipocyte-specific gp130 deletion significantly reduced KD-induced hepatic steatosis by suppressing lipolysis in white adipose tissue and reducing p-JNK and p-p38 signaling in the liver. In agreement, adipocyte-specific deletion of gp130 protected mice from KD-induced hepatic steatosis in response to recombinant IL-6 treatment.

Conclusions: Our studies demonstrate the importance of adipose tissue-liver crosstalk in mediating MASLD progression and identify adipocyte IL-6-gp130 as a potential therapeutic target.