Inhibiting menin attenuates high-fat diet-induced weight gain by limiting intestinal lipid absorption in mice.

Intestinal lipid metabolism is essential for systemic energy homeostasis, and its modulation is emerging as a therapeutic strategy for obesity. Menin, encoded by the MEN1 gene, is a scaffold protein that regulates chromatin remodeling and gene expression and is abundantly expressed in intestinal epithelial cells (IECs), but its metabolic role remains underexplored. Here, we generated IEC-specific Men1-knockout mice and found that Men1 deficiency protected against high-fat diet-induced obesity, accompanied by elevated carboxylesterase 1 (CES1) expression in IECs. Increased CES1 promoted triglyceride (TG) hydrolysis and reduced intracellular TG storage, thereby limiting the lipid substrate pool required for ApoB48-dependent chylomicron assembly. Although lipid hydrolysis was enhanced, steady-state free fatty acid levels were not increased; instead, Men1 deficiency activated fatty acid β-oxidation programs and increased etomoxir-sensitive fatty acid-dependent mitochondrial respiration, supporting enhanced fatty acid catabolism. Mechanistically, menin recruited histone deacetylase 1 and interacted with the nuclear receptor liver X receptor-β to suppress Ces1g transcription, thereby sustaining efficient intestinal lipid absorption. Pharmacological inhibition of menin with MI-463 recapitulated the metabolic effects of inducible Men1 deletion. In a human gut organoid-on-chip system, MI-463 dose-dependently increased CES1 expression and markedly reduced lipid accumulation. Collectively, our findings identify menin as a regulator of intestinal lipid metabolism and suggest menin inhibition as a potential therapeutic strategy for obesity-related metabolic disorders.