Kisspeptin Mitigates Hepatic De Novo Lipogenesis in Metabolic Dysfunction-Associated Steatotic Liver Disease.

The peptide hormone kisspeptin, signaling via its receptor, KISS1R, decreases hepatic steatosis and protects against metabolic dysfunction-associated steatotic liver disease (MASLD). Enhanced de novo lipogenesis (DNL) contributes to MASLD. Here, we investigated whether kisspeptin treatment in obese, diabetic mice directly attenuates DNL. DNL was assessed in kisspeptin-treated mouse livers, using a mouse model of MASLD, (DIAMOND mice), employing (2)H(2)O-enriched water, mass spectrometry analysis, and transcriptomic profiling. Gene and protein expression were evaluated in primary hepatocytes and livers. Additionally, hepatic Kiss1r expression was increased in DIAMOND mice, following which various biochemical and metabolic assessments were employed. Metabolic tracing in kisspeptin-treated steatotic livers demonstrated a decrease in the DNL of free fatty acids (FFAs), known to be associated with diabetes, steatosis, and hepatocellular carcinoma. Transcriptomic profiling of kisspeptin-treated livers identified disruption of key metabolic pathways, the most prominent being a decrease in fatty acid metabolism, and downregulation of Cidea, a key regulator of lipid droplet formation. Kisspeptin treatment of FFA-loaded primary mouse hepatocytes significantly decreased Cidea expression. Mechanistically, we found that kisspeptin administration decreased levels of transcription factor SREBP-1c, a crucial regulator of DNL, and CIDEA. Thus, enhanced KISS1R signaling limits hepatic DNL, suggesting a crucial role in restricting MASLD.