Mitochondrial GTP Links Nutrient Sensing to β Cell Health, Mitochondrial Morphology, and Insulin Secretion Independent of OxPhos.

Mechanisms coordinating pancreatic β cell metabolism with insulin secretion are essential for glucose homeostasis. One key mechanism of β cell nutrient sensing uses the mitochondrial GTP (mtGTP) cycle. In this cycle, mtGTP synthesized by succinyl-CoA synthetase (SCS) is hydrolyzed via mitochondrial PEPCK (PEPCK-M) to make phosphoenolpyruvate, a high-energy metabolite that integrates TCA cycling and anaplerosis with glucose-stimulated insulin secretion (GSIS).

A Diet-Sensitive Commensal Lactobacillus Strain Mediates TLR7-Dependent Systemic Autoimmunity.

Western lifestyle is linked to autoimmune and metabolic diseases, driven by changes in diet and gut microbiota composition. Using Toll-like receptor 7 (TLR7)-dependent mouse models of systemic lupus erythematosus (SLE), we dissect dietary effects on the gut microbiota and find that Lactobacillus reuteri can drive autoimmunity but is ameliorated by dietary resistant starch (RS). Culture of internal organs and 16S rDNA sequencing revealed TLR7-dependent translocation of L.

Conventional Therapy in Adults With X-Linked Hypophosphatemia: Effects on Enthesopathy and Dental Disease.

Context: Treatment of X-linked hypophosphatemia (XLH) with active vitamin D metabolites and phosphate can partially correct skeletal deformities. It is unclear whether therapy influences the occurrence of two major long-term morbidities in XLH: enthesopathy and dental disease.

Objective: The objective of the study was to investigate the relationship between treatment and enthesopathy and dental disease in adult XLH patients.

OPG Treatment Prevents Bone Loss During Lactation But Does Not Affect Milk Production or Maternal Calcium Metabolism.

Lactation is associated with increased bone turnover and rapid bone loss, which liberates skeletal calcium used for milk production. Previous studies suggested that an increase in the skeletal expression of receptor activator of nuclear factor kappa-light-chain-enhancer of activated B cells ligand (RANKL) coupled with a decrease in osteoprotegerin (OPG) levels likely triggered bone loss during lactation. In this study, we treated lactating mice with recombinant OPG to determine whether bone loss during lactation was dependent on RANKL signaling and whether resorption of the maternal skeleton was required to support milk production.

Fibroblast growth factor 7: an inhibitor of phosphate transport derived from oncogenic osteomalacia-causing tumors.

Oncogenic osteomalacia (OO), a tumor-associated phosphate-wasting syndrome, provides an opportunity to identify regulators of renal phosphate homeostasis. We established cultures from OO-associated tumors. Conditioned medium from these cultures inhibited phosphate uptake in renal tubular epithelial cells.