O-GlcNAcylation regulates PPAR-driven metabolic programming in intestinal stem cells

SUMMARY Diet deeply influences health and disease risk by reshaping cellular metabolism. In the intestine, dietary nutrients directly affect intestinal stem cell (ISC) behavior, yet the regulatory mechanisms linking metabolism to transcriptional control remain poorly defined. Because mitochondria function as central metabolic hubs, we focused on mitochondrial signaling to understand how nutrient utilization governs ISC function. Using the MITO-Tag mouse, we isolated metabolites specifically from ISC mitochondria and found that the sugar-derived metabolite UDP-GlcNAc was reduced in ISCs from mice fed a high-fat diet. Moreover, we identified that reducing O-GlcNAcylation (OGN) rapidly increased stem cell frequency, proliferation, regenerative capacity, and the abundance of PPAR target proteins. Mechanistically, these effects depend on PPAR signaling, as genetic loss of Ppar-d/a blocks the ISC phenotypes induced by reduced OGN. These results reveal an OGN–PPAR signaling axis that translates dietary metabolic cues into transcriptional programs governing fuel utilization and ISC behavior in the intestine. Collectively, our findings highlight that OGN is a previously unrecognized regulator of PPAR signaling in intestinal stem cells.