ABSTRACT
Objective:To explore the effect of bone marrow mesenchymal stem cell transplantation on silicosis fibrosis in different time windows in rats.Methods:BMSCs were isolated and cultured from male 3-week-old SD rats in vitro.Fifty healthy female SD rats were randomly divided into 5 groups:control group,silicosis model group,early treatment group,middle treatment group,late treatment group(n=10).The silicosis model was made by one-time infusion of silica dust suspension using the non-exposed tracheal in-tubation(50 μg/ml),and 1 d,14 d,28 d of BMSCs were given for intervention therapy (1 ×106 ml-1 ).Rats in each group were sacrificed 14 days after treatment.The BMSCs identified by flow cytometry;the morphological changes of the lung tissues were observed by HE staining;the expression of MMP-9,collagen type Ⅰ and collagen type Ⅲ were detected by immunocytochemistry and Western blot analysis.Results: BMSCs in early silicosis ( 1 d ) and the middle silicosis ( 14 d ) compared to silicosis model group can significantly alleviate the pathological process of silicosis fibrosis (P0.05).Conclusion:Exogenous BMSCs transplantation on rat silicosis early pathological processes play a role in delaying , late treatment effect is not obvious.
ABSTRACT
Objective To observe expression of autophagy-related proteins LC-3 and Beclin-1 in alveolar macrophages in the silicosis model of rats , and to investigate the molecular mechanisms of silicosis formation from cells autophagy perspective .Methods Fifty adult male SD rats were randomly divided into control and model groups , 25 rats for each group .The silicosis model was made by one-time infusion of silica dust suspension through the trachea without exposed.The rats were sacrificed on the 1st, 3rd, 7th, 14th or 28th day after the modeling .Alveolar macrophages were obtained from bronchoalveolar lavage and used for subsequent research after culture and purification .Morphological characteristics of alveolar macrophages were observed by HE staining and transmission electron microscope ;The expression of LC-3 and Beclin-1 was detected by means of immunocytochemistry and Western blotting in each group .Results Compared with the control group , alveolar macrophages of the model group had larger volume and abundant cytoplasm , the phagocytic silica dust particles were observed in some cells , and autophagosomes were detected by transmission electron microscope .The expressions of LC-3 and Beclin-1 were increased at all time points in the model group ( P<0.05 ) .Both LC-3 and Beclin-1 began to increase at the 1st day.As the extension of time the expression gradually enhanced , peaked at the 14th day(P<0.05), and decreased at the 28th day, but higher than the basal expression .Conclusion Autophagy is activated in alveolar macrophages of the silicosis model , and alveolar macrophages autophagy is involved in the pathological process of silicosis in the rat .