Effect Of IL-19 On Airway Smooth Muscle Cells Proliferation And The Activity Of ERK Signal Transduction Pathway Of Asthmatic Rats

OBJECTIVE:To investigate the effect of IL-19 on airway smooth muscle cells (ASMCs) proliferation in asthmatic rats and expression of ERK1/2 mRNA and P-ERK1/2 of chronic asthmatic rats.METHODS: 20 healthy male wistar rats were accustomed to feed for one week and divided into two groups,weighing 250g.The rat model of asthma was made through ovalbumin (OVA) sensitization and excitation. Primary culture of ASMCs were established for experiments. ASMCs were treated with 1μg/L,10μg/L,100μg/L IL-19.After the establishment of asthma model,this experiment was divided into two parts.1. To investigate the effect of IL-19 on airway smooth muscle cells (ASMCs) proliferation of asthmatic rats. Primary culture of ASMCs were established for experiments, ASMCs were treated with 1μg/L,10μg/L,100μg/L IL-19. ASMCs were divided into 5 groups randomly : (1) control group;(2)asthmatic group;(3),(4),(5) group were intervened with different concentrations of IL-19. Adopt flow cytometry and MTT colorimetrics assay to detect the proliferation of ASMCs, and observe the influence of IL-19 of different concentrations on the proliferation of ASMCs.2. To investigate the effect of IL-19 on the activity of ERK signal transduction pathway of airway smooth muscle cells of chronic asthmatic rats. Primary culture of ASMCs were established for experiments, and groups are the same as the part 1.The expressions of ERK1/2 mRNA were detected by RT-PCR, the location and protein expressions of phosphorylated forms of ERK1/2(p-ERK1/2) were examined by the immunocytochemical staining.RESULTS:1. Compared with normal rats, the proliferation of ASMCs in chronic asthmatic rats and the percentage of cells at S phase was obvious increased.The percentage of cells at S phase of ASMCs in chronic asthmatic rats intervened by 10μg/L,100μg/L IL-19 was decreased and the proliferation of ASMCs was reduced compared with the asthmatic group,and there is difference between 10μg/L IL-19 group and 100μg/L IL-19 group. But these two indexes of ASMCs in chronic asthmatic rats have no obvious change after intervening by 1μg/L IL-19.2.Compared with normal rats, The expressions of ERK mRNA, p-ERK1/2 proteinin in ASMCs of asthmatic groups were obvious increased.These two indexes of ASMCs in chronic asthmatic rats intervened by 10μg/L,100μg/L IL-19 were significantly decreased . But the ASMCs in chronic asthmatic rat interved by 1μg/L IL-19 had no change compared with the asthmatic group.CONCLUSION:IL-19 may inhibit the proliferation of ASMCs and down-regulate expression of ERK1/2 mRNA and P-ERK1/2 in chronic asthmatic rats. IL-19 is likely to regulate the proliferation of ASMCs in chronic asthmatic rat through changing the gene transcription and protein expression of ERK.