Expression of HSP27 and BAX/BCL-2 apoptosis factor in silicosis rat model of fibrosis

Abstract

To study the expression of heat shock protein 27(HSP27), BAX and BCL-2 apoptosis in silicosis rat model, and to explore the correlation between HSP27 and BAX and BCL-2 apoptosis. Silicosis model was established by the oropharyngeal and endotracheal intubation. Forty SPF healthy adult Wistar male rats were randomly divided into 4 groups, with 10 rats in each group. Silicosis group for 6 weeks(feeding for 6 weeks), silicosis group for 8 weeks(feeding for 8 weeks): oropharyngeal and tracheal perfusion of 50 mg/mL SiO_2 suspension 1.0 mL/mouse; Model control group for 6 weeks and model control group for 8 weeks: 1.0 mL saline was infused into the oropharynx and trachea. Immunohistochemical staining was used to detect the expression of HSP27, BAX and BCL-2 in the right lower lung of silicosis model group at 6 and 8 weeks and model control group at 6 and 8 weeks. Western blot was used to detect the protein expression of HSP27, BAX and BCL-2 in the left lower lobe lung tissue of silicosis model group at 6 and 8 weeks and model control group at 6 and 8 weeks, respectively. Immunofluorescence staining was used to detect the colocalization of HSP27 with pro-apoptotic factor BAX and HSP27 with anti-apoptotic factor BCL-2. Compared with the model control group at 6 weeks and 8 weeks, the expression of HSP27 and pro-apoptotic factor BAX in fibrotic region increased, and the expression of anti-apoptotic factor BCL-2 decreased in silicosis model group at 6 weeks and 8 weeks(P<0.05). Immunofluorescence staining showed that there was colocalization of HSP27 and pro-apoptotic factor BAX in the fibrotic region. Correlation analysis showed that the correlation coefficient between HSP27 and pro-apoptotic factor BAX was r=0.94, indicating a positive correlation between them, while the correlation coefficient between HSP27 and anti-apoptotic factor BCL-2 was r=-0.81, indicating a negative correlation between them. High expression of HSP27 and pro-apoptotic factor BAX and low expression of anti-apoptotic factor BCL-2 exist in silicosis rats, and their expression is correlated.