Expression of microtubule-associated protein 1 light chain 3 and Beclin-1 in alveolar macrophages of silicosis rats / 解剖学报

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 .