Effects of Ophiopogonis Root Decoction on a mouse model of idiopathic pulmonary fibrosis based on PD-1/PD-L1 signaling pathway / 中成药

ABSTRACT

AIM To investigate the effects of Ophiopogonis Root Decoction on bleomycin(BLM)-induced idiopathic pulmonary fibrosis(IPF)in mice and to explore its metabolic modulation of immunity.METHODS The IPF mouse model was constructed by tracheal drip injection of BLM,and the mice were randomly divided into the control group,the model group,the pirfenidone group(0.3 g/kg)and the high,medium and low dose groups of Ophiopogonis Root Decoction(18,9,4.5 g/kg).HE and Masson staining,ELISA,flow cytometry and immunohistochemistry were used to detect the histopathological changes of the lung,the levels of Collagen I,HYP and TGF-β1,the proportion of PD-1+ CD4+T cells in plasma,and the expressions of p-STAT3,PD-1,PD-L1 and IL-17A in lung tissue,respectively.RESULTS Compared with the control group,the model group displayed significantly higher level of lung coefficients(P<0.01),more severe pulmonary inflammatory cell infiltration and collagen fiber deposition,and increased pulmonary fibrosis score(P<0.01),increased levels of Collagen I,HYP and TGF-β1(P<0.01),increased proportion of PD-1+ CD4+ T cells in plasma(P<0.01),increased pulmonary expression of p-STAT3,PD-1,PD-L1 and IL-17A(P<0.01).Compared with the model group,the Ophiopogonis Root Decoction groups shared lower levels of lung coefficients(P<0.05),less pulmonary inflammatory cell infiltration and collagen fiber deposition,decreased pulmonary fibrosis score(P<0.05),decreased levels of Collagen I,HYP and TGF-β1(P<0.05),decreased proportion of PD-1+ CD4+T cells in plasma(P<0.05),and decreased pulmonary expression of p-STAT3,PD-1,PD-L1,and IL-17A(P<0.05).CONCLUSION Ophiopogonis Root Decoction can significantly reduce extracellular matrix(ECM)deposition and curb the progression of IPF via inhibition of STAT3/PD-1/PD-L1 immunomodulatory signaling pathway.