The Role And Mechanism Of 1,25-Dihydroxyvitamin D-3 In Regulating The Rho-Kinase Signaling Pathway In Asthmatic Rats

Background: Bronchial asthma (referred to as asthma in the present study) is the most common chronic airway inflammatory disease in childhood. The present study aimed to investigate the effect of 1,25-dihydroxyvitamin D-3 [1,25-(OH)(2)D-3] on VDR expression, which is closely associated with asthmatic airway smooth muscle cells (ASMCs), and explored its role and mechanism in the Rho-kinase signaling pathway.Methods: The acute asthma model was induced by ovalbumin (OVA) and pertussis bacillus, and ASMCs obtained from asthmatic rats were cultured in vitro. These cells were randomly divided into five groups: control (N) group, TNF-alpha (TNF) group, 1,25-(OH)(2)D-3 (VD) group, dexamethasone (DXM) group, and 1,25-(OH)(2)D-3 + DXM (L) group. The protein expression levels of VDR, ROCK, MLC20 and P-MLC20 were detected by western blot, and the mRNA expression levels of VDR, ROCK, MLC20 and P-MLC20 were detected by real-time quantitative PCR.Results: The expression of ROCK, MLC20 and P-MLC20 in each treatment group were significantly lower, when compared to the TNF group (P<0.05), but this remained stronger than (P<0.05) or similar to (P>0.05) that in the N group.Conclusions: The regulation mechanism of 1,25-(OH)(2)D-3 in alleviating asthma should be correlated to its regulation of the expression of related signaling molecules in the Rho-kinase signaling pathway, and this effect may be achieved by regulating the mRNA and protein expression of the VDR gene.