Expression of interleukin-17 in a murine model of experimental systemic sclerosis and its correlation with transforming growth factor-beta 1 / 中华风湿病学杂志

ABSTRACT

ObjectiveThe expression and significance of interleukin(IL)-17 in a murine model of experimental systemic sclerosis(SSc) was studied and its correlation with transforming growth factor-beta 1 (TGF-β1) was explored.Methods Thirty female BALB/c mice were randomly divided into 3 groups,including a control group, bleomycin(BLM) injection for 4 weeks group(model 1 group) and a termination injection of BLM 4 weeks group(model 2 group).The pathological changes of skin and lung were detected.The mRNA expressions of IL-17A,RORγt,TGF-β1 mRNA were evaluated by real-time PCR.Enzyme linked immunosorbent assay was used to measure the levels of IL-17 and TGF-β1 in the serum and bronchoalveolar lavage fluid(BALF).Comparisons among groups were performed by variance analysis.ResultsSkin and lung of the model groups showed evident inflammatory cell infiltration and increased deposition of collagen fibers.The score of dermal inflammation and lung fibrosis was significantly higher in the model 1 and model 2 groups (2.5±0.8,3.0±1.8), (2.4±0.8,3.1±1.2) as compared to that of the control group (0.9±0.7,0.9±1.0),(F=12.19,8.367,25.11,4.641; all P＜0.05).The amount of hydroxyproline was markedly increased in the model groups than in the control group.Compared with those of the control group,the mRNA levels of IL-17A,RORγt,TGF- 31 in the skin and lung of the model 1 group were higher.The levels of IL-17 in serum and BALF of the model 1 group was significantly increased and the levels of TGF- β1 were increased in BALF and decreased in the serum (all P＜0.05).The mRNA levels of IL-17A in skin and lung had a positive correlation with the mRNA levels of TGF- β1,score of dermal inflammation and lung fibrosis.The levels of IL-17 in serum had a positive correlation with hydroxyproline of the skin and lung.ConclusionIL-17 may participate in systemic immune-mediated inflammation and changes of skin and lung in SSc and when combined with TGF-β1 togetter will cause damage to skin and lung in SSc.