Abstract:

Objective · To investigate the effects of transforming growth factor β1 (TGF-β1) on epithelial-mesenchymal transition (EMT) in pleural mesothelial cells in patients with tuberculous pleurisy and relevant mechanisms. Methods · 35 patients with tuberculous pleurisy were enrolled and underwent thoracoscopy test. Pleural effusion specimens were collected and pleural mesothelial cells (PMCs) were Isolated and purified. The PMCs were cultured and divided into different groups, i.e. the blank control group (containing only cell culture medium), the TGF-β1 treatment group (adding 5 μg/L of recombinant human TGF-β1), the PD150606 treatment group (adding 20 mg/L of PD150606), and the combined group (adding 5 μg/L of recombinant human TGF-β1 and 20 mg/L of PD150606). The gene and protein expressions of calpain-1, CK8, E-cadherin, vimentin, and α-SMA were measured using real-time PCR and Western blotting 48h after culture. Results · EMT was induced in PMCs in the TGF-β1 treatment group with typical characteristics of mesenchymal cells compared with the blank control group. Adding calpain inhibitor PD150606 could block the TGF-β1 induced EMT in PMCs. The TGF-β1 treatment group had higher gene and protein expressions of calpain-1, lower gene and protein expressions of CK8 and E-cadherin, and higher gene and protein expressions of vimentin and α-SMA than the blank control group. The combined group had lower gene and protein expressions of calpain-1, higher gene and protein expressions of CK8 and E-cadherin, and lower gene and protein expressions of vimentin and α-SMA than the TGF-β1 treatment group after adding PD150606. The differences in gene and protein expressions of calpain-1, CK8, E-cadherin, vimentin, and α-SMA between the blank control group and the combined group were not significant, as well as between the PD150606 treatment group and the blank control group. Conclusion · TGF-β1 might induce EMT in PMCs in patients with uberculous pleurisy through up-regulation of calpain-1.

Key words: tuberculous pleurisy, epithelial-mesenchymal transition, transforming growth factor β1, calpain