Effects of Ursolic Acid on the Biological Function of Scar Fibroblasts and the TGF-β1/Smads Pathway

The aim of this study is to investigate the effects of ursolic acid on the biological function of scar fibroblasts and the TGF-β1 (transforming growth factor-β1)/Smads pathway. By culture with different doses of ursolic acid (0, 10, 20, 30, 40, 50, 60 μmol/L), cell survival rate of HSFB (hypertrophic scar fibroblast) in logarithmic growth phase was firstly detected by MTT methods. After that, five experimental groups, named as control group (without ursolic acid adding in culture medium), L-ursolic acid group (with 20 μmol/L ursolic acid adding in culture medium), M-ursolic acid group (with 40 μmol/L ursolic acid adding in culture medium), H-ursolic acid group (with 60 μmol/L ursolic acid adding in culture medium), H-ursolic acid+SRI-011381 group (with 60 μmol/L ursolic acid and 10 μmol/L TGF-β1/Smads pathway activator SRI-011381), were selected for the further study. Apoptosis of HSFB when culture in the above groups was determined by flow cytometry and TUNEL staining. Transwell experiment was applied to measure migration and invasion abilities of HSFB. Western blot was applied to determine the expression of TGF-β1/Smads pathway proteins (TGF-β1, p-Smad2, p-Smad3, Smad4), fibrotic proteins (Col1A1, Col 3A1, α-SMA), and apoptotic proteins (Bax, Bcl-2) in each group. The result showed that with the concentration of ursolic acid increased in culture medium, the survival rate of HSFB gradually decreased in a dosedependent manner (P<0.05). As compared with the blank control, the apoptosis rate, proportion of TUNEL positive cells and expression of Bax protein in HSFB in the L-ursolic acid group, M-ursolic acid group, and H-ursolic acid group were all increased (P<0.05), while the numbers of migrating cells, invading cells, and the expression of fibrotic marker proteins (Col 1A1, Col 3A1, α-SMA, Bcl-2, TGF-β1/Smads pathway related proteins) of HSFB were all reduced on the contrary (P<0.05). Those degree of change in H-ursolic acid group was more obvious than that of L-ursolic acid group (P<0.05). Furthermore, the apoptosis rate, proportion of TUNEL positive cells and expression of Bax protein of HSFB in H-ursolic acid+SRI-011381 group were reduced (P<0.05), while the numbers of migrating cells, invading cells, and the protein expression of fibrotic marker proteins (Col 1A1, Col 3A1, α-SMA), Bcl-2, TGF-β1/Smads pathway related proteins in H-ursolic acid+SRI-011381 group were increased (P<0.05), as compared with that of the H-ursolic acid group. As a reminder, ursolic acid can effectively inhibit the proliferation, invasion, migration, and fibrosis (Col 1A1, Col 3A1, α-SMA) of HSFB, and further induce HSFB’s apoptosis. All the biological processes of HSFB that mediated by ursolic acid may be related to inhibiting the activation of TGF-β1/Smads signaling pathway.

CSTR: 32200.14.cjcb.2024.11.0008