The Effects Of Gremlin On Collagen Expression Induced By Paraquat In Lung Fibroblasts

Background and Objective: The patient with paraquat intoxation can develop to pulmonary fibrosis after acute stage,which is high mortality and mutilation. The pathogenesy of paraquat induced pulmonary fibrosis is primarily unknown.There has no specific treatment options with significant effect on patient survival at present. Gremlin, secreted antagonists of bone morphogenic proteins, have been shown to overexpress in fibrotic desease,however, the profibrotic role of Gremlin has not been clarified so far. The study suggests that paraquat is characterized by resulting in fibrosis directly and induces Gremlin expression. The endogenous Gremlin plays an important role in collagen production induced by paraquat.Methods: Primary lung fibroblasts isolated from BALB/C mouse were cultured,then,identified with cell shape and immunocytochemistry. The Fibroblasts were divided into 5 groups.control group:the cells treated with medium.PQ group: the cells treated with 25μM PQ in the medium.Gremlin Ab group: the cells treated with Gremlin Ab 5μg/ml in the medium.PQ+ Gremlin Ab group: the cells treated with 25μM PQ and Gremlin Ab in the medium. After 12h, Immunohistochemistry (IHC) was used to compare the production of collagen typeⅠand typeⅢandα-SMA.ResuIt:(1)The primary cells showed round nucelus and fusiform shape under microscope. Immunoctyochemistryassay showed that cultured lung cells had positive staining of vimentin, but negative ofkeratin. These data proved that the cultured cells were lung fibroblasts.(2)The cultured cell incubated with 25μM paraquat overexpressed gremlin by 1HC,in contrast,normal fibroblasts expressed no gremlin(P＜0. 05).(3) At the protein level, expression ofα-SMA, ColⅠand ColⅢin cultured fibroblasts was measured by immunocytochemical method. The results showed paraquat induced fibroblasts expression ofα-SMA, ColⅠ, ColⅢ, and Gremlin Ab inhibited the effects of paraquat on the expression ofα-SMA, ColⅠ, ColⅢin fibroblasts in dose-independent manner(P＜0. 05).Conclusion: paraquat stimulated fibroblasts expression of endogenous gremlin and collagen production.To give gremlin affinity purified polyclonal Ab inhibit collagen synthesis induced by paraquat.