bioRxiv Science⌕ Search

Biology subjects

Diaz-Rubio, M. E.

Publications and source records attributed to Diaz-Rubio, M. E..

2 recordsLinked to original sources

A dietary pan-amino acid dropout screen in vivo reveals a critical role for histidine in T-ALL

Dietary interventions show therapeutic potential in cancer, but systematic comparisons are lacking. We performed a dietary pan-amino acid dropout screen in an orthotopic model of NOTCH1-driven T-cell acute lymphoblastic leukemia and identified histidine depletion as uniquely antileukemic. Histidine-restricted diets extended survival of leukemic mice in a dose-dependent manner, while remaining well-tolerated. Mechanistically, multiomic profiling revealed that histidine deprivation-induced ribosome stalling activates GCN2 to suppress cholesterol biosynthesis pathways critical for leukemic proliferation. Dietary cholesterol supplementation partially reverted the antileukemic effects of histidine restriction in vivo. These findings couple histidine levels and translational control to cholesterol metabolism, which can be therapeutically exploited for cancer treatment. Our results suggest that defined dietary amino acid restrictions may expose broader therapeutic opportunities in diseases beyond cancer.

cancer biology↗

Gut microbiota phospholipids regulate intestinal gene expression and can counteract the effects of antibiotic treatment

The gut microbiome influences immune and metabolic homeostasis. Our research using non-obese diabetic (NOD) mice revealed that early-life antibiotic exposure remodels the gut microbiome affecting metabolism and accelerating type 1 diabetes (T1D) incidence, with cecal material transplant (CMT) mitigating the damage. Now examining murine intestinal lipidomic profiles, we identified 747 compounds. Comparing the lipidomic profiles of cecal contents of conventional and germ-free mice and their diets, we identified 87 microbially-produced lipids reduced by antibiotic exposure but CMT-restored. Parallel analysis of human fecal lipid profiles after azithromycin-exposure showed significant alterations with substantial overlap with mice. In vitro co-culture with mouse macrophages or small intestinal epithelial cells and human colonic epithelial cells identified phospholipids that repress inflammation through the NF{kappa}B pathway. Oral administration of these phospholipids to antibiotic-treated NOD mice reduced expression of ileal genes involved in early stages of T1D pathogenesis. These findings indicate potential therapeutic anti-inflammatory roles of microbially-produced lipids.

microbiology↗