Effect Of Vitamin D On Lps-induced Mice Acute Lung Injury

Objective: To investigate the role and mechanism of vitamin D involving in lipopolysaccharide(LPS)-induced mice acute lung injure(ALI).Methods: Forty-five C57BL/6 mice were randomized into control group,LPS group and vitamin D treated group(VD+LPS)(n=15).Mice were orally pretreated with three dose of 1,25-(OH)2D3(25?g/kg)at 1h,24 h and 48 h before LPS induction;control group and LPS group were treated with same volume of dimethylsulfoxide(DMSO).ALI mice model were constructed by tracheal intubation of 3mg/kg LPS,mice were sacrificed after 2 days.The proportion of neutrophils in bronchoalveolar lavage fluid(BALF)was measured.Enzyme-linked immunosorbent assay(ELISA)was used to detect the interleukin-6(IL-6),tumor necrosis factor-?(TNF-?)and interleukin-17A(IL-17A)levels in BALF.HE staining was conducted to value the lung tissue pathological changes.Wet to dry ratio(W/D)was detected to evaluate the degree of lung edema.Flow cytometry was adopted to analyze the proportion of T helper 17 cells(Th17).Western blotting(WB)and quantitative real-time polymerase chain reaction(qPCR)were used to evaluate the expressions of retinoic acid-related orphan receptor ?t(ROR?t)in protein and mRNA levels.Results: Pretreated with vitamin D significantly decreased proportion of neutrophils and levels of IL-6,TNF-? and IL-17 A in BALF(P<0.05).The degree of lung injury and lung edema was decreased(P<0.05).Th17 cells proportion was decreased in VD+LPS group(P<0.05).Meanwhile,ROR?t decreased in both protein and mRNA levels after 1,25-(OH)2D3 treatment(P<0.05).Conclusion: Vitamin D may alleviate LPS-induced mice ALI partially through inhibiting the inflammation reaction mediated by Th17 cells.