Oral cholecalciferol supplementation alleviates lipopolysaccharide-induced preterm delivery partially through regulating placental steroid hormones and prostaglandins in mice.

Several epidemiological reports demonstrated that vitamin D deficiency elevated risk of preterm delivery. We investigate the effects of oral cholecalciferol (VD3) supplementation on lipopolysaccharide (LPS)-induced preterm delivery. Pregnant mice were randomly assigned to either oral VD3 (25 μg/kg) or corn oil once daily from gestational day (GD)13 to GD15, and were intraperitoneally injected with either LPS (200 μg/kg) or normal saline on GD15. As expected, LPS was effective in inducing preterm delivery and fetal death. LPS-induced preterm delivery and fetal death were alleviated in VD3-pretreated mice. LPS-induced down-regulation of genes for placental progesterone biosynthetic enzymes was blocked in VD3-pretreated mice. LPS-induced reduction of serum progesterone was correspondingly attenuated by VD3. Although oral VD3 had no effect on estradiol production, it attenuated LPS-induced up-regulation of placental ERβ in mice. LPS-induced placental COX-2 up-regulation and serum PGF2α elevation were alleviated in VD3-pretreated mice. Additionally, LPS-evoked elevations of the placental Tnfα, Il1β, Mcp1 and Mip2 mRNAs were attenuated by VD3. VD3 promoted placental vitamin D receptor nuclear translocation and simultaneously alleviated LPS-induced nuclear translocation of NF-κB p65 and p50 subunits. These results provide evidence that oral VD3 supplementation alleviates LPS-induced preterm delivery and fetal demise partially through regulating placental steroid hormones and prostaglandins.