Aim of study
To investigate the therapeutic effect of idiopathic pulmonary fibrosis (IPF) of GGD, a bleomycin-induced IPF murine model was used in this study. Materials and
Conclusion
Our results indicate that GGD positively affects IPF by regulating PD-1/TGF-β1/IL-17A pathway.
Methods
Mice were induced by bleomycin instillation and GGD was orally administered. Changes on mice weight were recorded during the experiment. Lung weight was recorded on days 14 and 28, and pulmonary index was calculated accordingly. Pathological evaluation, including fibrosis analysis of lung tissue, was assessed by H&E and Masson staining. The expression of PD-1, p-STAT3 and IL-17A were detected by immunohistochemistry (IHC). The expression of p-STAT3 in lung tissues of mice were detected by Western blot. The level of IL-17A in lung tissue were detected by ELISA. The expression of PD-1 in CD4+ T cells in peripheral blood of mice was detected by flow cytometry. The levels of hydroxyproline and TGF-β1 in lung tissue were detected by ELISA. The expression of E-cadherin, vimentin and α-SMA in lung tissues of mice were detected by qRT-PCR and Western blot.
Results
GGD can increase body weight and reduce pulmonary index in mice with pulmonary fibrosis. As such, GGD can significantly improve the inflammatory and alleviate IPF in the lung tissue of mice. GGD treatment was capable of reducing the content of PD-1 in lung tissue as well as the expression of PD-1 in CD4+ T cells in peripheral blood. Likewise, GGD was able to reduce the content of p-STAT3, IL-17A and TGF-β1. In addition, GGD stimulation could inhibit epithelial-mesenchymal transformation (EMT) by increasing the expression of E-cadherin and reducing vimentin and α-SMA, thus reducing extracellular matrix (ECM) deposition.