Biology subjects

Hartley McDermott, T.

Publications and source records attributed to Hartley McDermott, T..

3 recordsLinked to original sources

bioRxiv2026

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

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.

cell biology↗

bioRxiv2026

Maternal obesity induces developmental programming of Intestinal stem cells through an IL-17A/PPAR immune-epithelial axis

Maternal obesity is associated with increased risk of sporadic colorectal cancer (CRC) in offspring, suggesting that early-life environmental exposures durably shape disease susceptibility. Intestinal stem cells (ISCs), long-lived drivers of epithelial renewal and tumor initiation, are well poised to mediate this effect; however, how maternal obesity influences ISC programming during development remains poorly understood. Using mouse models of diet-induced obesity, we show that exposure to a maternal high-fat Western diet (mHFD) during pre- and postnatal development stably programs colonic ISCs. Offspring exhibit increased ISC proliferation, enhanced self-renewal, a hypermetabolic state, and altered epithelial lineage composition that persists into adulthood despite dietary normalization. These changes are accompanied by increased tumor burden following loss of Apc heterozygosity. Mechanistically, we identify the pro-inflammatory cytokine IL-17A as a key extrinsic driver and PPARd/a nuclear receptors as intrinsic mediators of the mHFD phenotype, revealing an immune-epithelial axis that programs ISC function during early life. Together, our findings demonstrate that maternal metabolic environments durably enhance stem cell fitness, providing a mechanistic link between developmental exposure and adult disease risk.

cell biology↗

bioRxiv2026

Diet-induced chromatin states influence intestinal stem cell memory

Intestinal stem cells (ISCs) integrate dietary cues through a metabolic-transcriptional axis, but whether these mechanisms create a lasting epigenetic memory remains unclear. Here, we investigate diet-induced chromatin adaptations in ISCs using a high-fat Western diet (HFD) mouse model. HFD broadly remodels chromatin accessibility, altering pre-existing open regulatory regions. Many differentially accessible regions (DARs) persist during the differentiation of ISCs into transient amplifying cells (TACs). Notably, HFD-induced DARs are retained following diet normalization despite phenotypic reversibility, and HFD re-exposure enhances ISC self-renewal and adenoma growth compared with naive HFD exposure. The HFD-induced chromatin changes require Ppar-d/a nuclear receptors but are independent of their transcriptional targets. Although a subset of HFD-induced DARs is maintained following Apc loss, extensive chromatin remodeling driven by tumor suppressor inactivation largely overrides diet-dependent differences in Lgr5 ISCs. Together, these findings demonstrate that ISCs retain a chromatin-based memory of dietary fat exposure.

cell biology↗