[Effect and its molecular mechanisms of curcumin on pulmonary artery smooth muscle cells in rat model with chronic obstructive pulmonary disease].

To investigate the effects and the underlying molecular mechanisms of curcumin on pulmonary artery smooth muscle cells in rat model with chronic obstructive pulmonary disease (COPD). A total of 75 male Wistar rats were randomly divided into control group (group CN), model group (group M), low-dose curcumin group (group CL), medium-dose curcumin group (group CM) and high-dose curcumin group (group CH). HE staining was used to observe the morphology of pulmonary artery. Proliferating cell nuclear antigen (PCNA), apoptosis-related protein Bcl-2 and Bax were detected by immunohistochemical staining. TUNEL kit was used to analyze the effects of curcumin on apoptosis of smooth muscle cells, and the protein expressions of SOCS-3/JAK2/STAT pathway in lung tissues were determined by western blot. Right ventricular systolic pressure (RVSP) and right ventricular hypertrophy index (RVMI) in group M were significantly higher than those in group CN, group CH and group CM (all <0.05). HE staining and TUNEL kit test showed that the number of pulmonary artery smooth muscle cells had a significant increase in group M, while the pulmonary artery tube became thin, and the smooth muscle cells shrinked in group CM and group CH. Immunohistochemistry showed that PCNA and Bcl-2 in group M were significantly higher than those in group CN (all <0.05), while Bax expression was significantly lower than that in group CN (<0.05). PCNA in group CM and group CH were significantly lower than that in group M (all <0.05), while Bax expression was significantly higher than that in group M (<0.05). Western blot showed that SOCS-3 protein was significantly decreased in group M, while the p-JAK2, p-STAT1, p-STAT3 were significantly increased (all <0.05). Compared with group M, SOCS-3 protein in group CM and group CH were significantly increased (all <0.05), while the p-JAK2, p-STAT3 were significantly reduced (all <0.05). Curcumin could promote the apoptosis of smooth muscle cells in rats with COPD, and improve the mean pulmonary artery pressure and RVMI through stimulating SOCS-3/JAK2/STAT signaling pathway.