[Expression of HSP27, JAK2 and STAT3 apoptosis factors in silicotic fibrosis rat model]

To explore the relationship between heat shock protein 27(HSP27) and Janus kinase 2(JAK2), Recombinant signal transducer and activator of transcription 3(STAT3) related factors, To further explore the mechanism of silicosis fibrosis and potential therapeutic targets.

The gene expression profile microarray(GSE110147) of a patient with pulmonary fibrosis was obtained from the gene Expression Omnibus(GEO) database, and the HSP27 high expression was set and the genes related to apoptosis pathway were screened out. The STRING online database was used to construct the key gene target map, and the protein interaction network(PPI) was constructed by Cytoscape. The correlation between HSP27 and JAK2, HSP27 and STAT3 was analyzed. The silicosis model was established by one-time instillation of silica(SiO_2) suspension through oropharyngeal endotracheal intubation. Twenty SPF healthy adult Wistar male rats aged 8 weeks were randomly divided into 4 groups, with 5 rats in each group. Silicosis model group for 6 weeks(feeding for 6 weeks) and silicosis model group for 8 weeks(feeding for 8 weeks): oropharyngeal intratracheally instilled 50 mg/mL SiO_2 suspension 1.0 mL per animal. Model control group for 6 weeks(feeding for 6 weeks) and model control group for 8 weeks(feeding for 8 weeks): saline 1.0 mL/animal was instilled into oropharynx and trachea. The pathological changes of lung tissue were observed. The silicon nodule samples were subjected to immunofluorescence assay, and the quantitative analysis of HSP27 and JAK2 apoptosis protein was performed by Western blot.

The correlation coefficient between HSP27 and STAT3, JAK2 was r=-0.815, P<0.01, and the correlation coefficient between HSP27 and STAT3 was r=-0.817, P<0.01, HSP27 and JAK2, STAT3 had a negative correlation. After the rats were exposed to dust, the silicosis model groups of 6 weeks and 8 weeks had significantly increased silicotic nodules in the lung. The result of immunofluorescence staining showed that HSP27, JAK2 and STAT3 were co-expressed in the fibrotic area. Compared with the model control group of 6 weeks and 8 weeks, the expression of HSP27, JAK2 and STAT3 in the fibrotic area of the silicosis model group of 6 weeks and 8 weeks increased, and the difference was statistically significant(With the extension of modeling time, the expression of HSP27 protein in the silicosis model 8 weeks group was higher than that in the silicosis model 6 weeks group(P<0.05). The expression of JAK2 protein in the 8-week silicosis model group was lower than that in the 6-week silicosis model group(P=0.32), and the expression of STAT3 protein was lower than that in the 6-week silicosis model group(P<0.05).

HSP27, JAK2 and STAT3 are highly expressed in the silicotic nodules of the rat model of silicosis. HSP27 is negatively correlated with JAK2 and STAT3.