1,25-dihydroxyvitamin D3 regulates enteroglial bioactivity through butyric acid pathway in a high-fat diet mouse model.

1,25-dihydroxyvitamin D3 (1,25(OH)2D3), affects enteric glial cells (EGCs) activity, but the mechanism is still unknown. The current study aimed to explore whether 1,25(OH)2D3 could regulate EGCs activity via butyrate pathway in a high-fat diet model. Male C57BL/6 J mice were fed with standard diet (SDD), or vitamin-D-deficient diet (VDD), or high-fat diet (HFD), or HFD plus sodium butyrate (SBR), or HFD plus 1,25(OH)2D3, or HFD plus S100B inhibitor ONO-2506 in vivo. CRL-2690 and Caco-2 cells were treated with palmitic acid (PA) and oleic acid (OA) complex, or S100B, or S100B plus butyric acid (BA) in vitro. 25(OH)D3, 1,25(OH)2D3, TNF-α and S100B concentrations were assayed by enzyme-linked immuno- sorbent assay (ELISA). Colonic mucosal permeability was measured by using FITC-dextran 4 kDa. Colonic butyrate was detected using high-performance liquid chromatography (HPLC). The results showed HFD decreased serum 25(OH)D3 and 1,25(OH)2D3 concentrations and colonic butyrate generation. 1,25(OH)2D3 supplementation raised butyrate production in the colon. 1,25(OH)2D3 and sodium butyrate supplementation inhibited EGCs to produce S100B and reduced colonic permeability to FITC-dextran. Inhibition of S100B pathway by ONO- 2506 decreased colonic hyperpermeability. In vitro experiments showed butyrate treatment not only reduced S100B and TNF-α secretion from PA/OA-treated CRL-2690 cells, but also decreased the permeability of S100B-treated Caco-2 cells. Collectively, 1,25(OH)2D3 elicited butyrate to suppress EGCs activation, which helped to prevent intestinal barrier injury.