The Experimental Study Of Repressing Silicosis Early Fibrosis

Objective:To compare the curative effects of bone marrow-derived mesenchymal-like stem cells (BM-MSCs) and BM-MSCs transfected by pcDNA3.1-HGF in treating SiO2-induced alveolitis and early fibrosis and to study the mechanism of their effects.Methods:1.Primary BM-MSCs from Wistar male young rats were cultured and marked by 4, 6-diamidino-2-phenylindole (DAPI).2.50 wistar rats were randomly divided into 3 groups:model group, administered with SiO2 by the trache, in the next day, injected PBS via the tail vein; BM-MSCs group, administered with SiO2 by the trache, in the next day, injected the suspension of BM-MSCs via the tail vein; pcDNA3.1-HGF+BM-MSC group, administered with SiO2 by the trache, in the next day, injected the suspension of BM-MSCs transfected by pcDNA3.1-HGF via the tail vein.3.Each half of the animals were sacrificed on the 14th,28th day after treatment, and their lungs were harvested for frozen section to observe the cells marked by DAPI. HE staining to observe pulmonary alveolitis and Masson staining to observe fibrosis. Western blot was employed to detect the expression of HGF in BM-MSCs and lung of the rats that treated by BM-MSCs tranfected by pcDNA3.1-HGF. The expression of tumor necrosis factor-a(TNF-a) in pulmonary tissues were analyzed quantitatively by ELISA, HYP in pulmonary tissues were analyzed quantitatively by sample hydrolysis method.Results:1.After induced by SiO2, the lung tissues were obtained and stained by HE,Masson,the pathological changes were in accordance with pulmonary fibrosis.2.Under fluorescence microscope, the cells marked by DAPI were observed in the lung tissues of both BM-MSCsgroup and pcDNA3.1-HGF+BM-MSCs group. 3.The results of HE, Masson staining and HYP showed that in the 14th,28thd after treatment, compared with model group, pneumonia and pulmonary fibrosis were significantly reduced in the rats BM-MSCs group and pcDNA3.1-HGF+BM-MSCs group(P<0.05), the effects of pcDNA3.1-HGF+BM-MSCs group is more significant(P<0.05).4.The TNF-a content in the 28thd were lower than that in 14thd in lung tissues of model group(P<0.05). The TNF-a content of both BM-MSCs group and pcDNA3.1-HGF+BM-MSCs group in the 14th,28thd after treatment were lower than the model group (P<0.05), the TNF-a content of pcDNA3.1-HGF+BM-MSCs group was the lower compared with the BM-MSCs group in the both time.Conclusion:BM-MSCs transfected by pcDNA3.1-HGF was more effective than used BM-MSCs alone in treating SiO2-induced alveolar inflammation and early pulmonary fibrosis, the mechanism was likely thought to be involving with the pneumonia reduced by BM-MSCs transfected by pcDNA3.1-HGF in lung tissue.