Effect of dexamethasone on P311/TGF-β1/α-SMA signaling pathway in rabbit biliary fibroblasts

Abstract:

Objective：To investigate effects of dexamethasone（DEX） on P311/transforming growth factor-β1（TGF-β1）/α-smooth muscle actin（α-SMA） signaling pathway in benign biliary stricture（BBS） model fibroblast（MF）. Methods：Two normal rabbits were treated with normal bile duct fibroblasts（NF），BBS model was established via discission and anastomosis of two rabbits and MF was acquired；then they were divided into five groups：NF，MF，MF plus different concentration of DEX（0.02，0.1 and 0.5 mg/mL） groups. After respectively incubated with 48 h，cell proliferation was investigated by CCK-8；Relative mRNA expression of P311，TGF-β1 and α-SMA were assessed by real-time PCR；Relative protein expression of TGF-β1 and α-SMA were investigated by western blot. Results：①optical density（A） in each group：0.331±0.002 in the NF group，0.533±0.005 in the MF group，0.487±0.003 in the MF+DEX 0.02 group，0.434±0.004 in the MF+DEX 0.1 group，0.381±0.004 in the MF+DEX 0.5 group；②P311 mRNA in each group：1.000 0±0.024 8 in the NF group，4.146 3±0.037 1 in the MF group，3.789 9±0.056 8 in the MF+DEX 0.02 group，3.566 1±0.148 1 in the MF+DEX 0.1 group，2.945 8±0.654 0 in the MF+DEX 0.5 group；③TGF-β1 mRNA in each group：1.000 0±0.034 6 in the NF group，2.647 9±0.048 5 in MF group，1.929 7±0.054 8 in the MF+DEX 0.02 group，1.678 2±0.080 2 in MF+DEX 0.1 group and 1.676 2±0.036 9 in the MF+DEX 0.5 group；④cells α-SMA mRNA in each group：1.000 0±0.056 0 in the NF group，4.025 7±0.065 9 in the MF group，3.644 9±0.196 4 in the MF+DEX 0.02 group，2.712 9±0.102 4 in the MF+DEX 0.1 group and 2.320 7±0.031 2 in the MF+DEX 0.5 group；⑤TGF-β1 protein values in each group：0.999 6±0.046 3 in the NF group，2.096 3±0.029 3 in the MF group，1.781 8±0.040 4 in the MF+DEX 0.02 group，1.531 4±0.032 5 in the MF+DEX 0.1 group，and 1.384 0±0.035 7 in the MF+DEX 0.5 group；⑥The number of α-SMA protein in each group：1.000 8±0.051 4 in the NF group，3.2314±0.1160 in the MF group，2.875 3±0.078 0 in the MF+DEX 0.02 group，2.262 8±0.059 8 in the MF+DEX 0.1 group and 1.940 8±0.093 7 in the MF+DEX 0.5 group. After 48 h of DEX intervention，cell proliferation was significantly inhibited and both the mRNA and protein expression of P311，TGF-β1 and α-SMA（all P<0.05，0.1~0.5 mg/mL） were significantly regulated down，with a dose-dependent manner. Conclusion：Mechanism of DEX on anti-BBS may be because it is relevant to modulation of P311/TGF-β1/α-SMA signaling pathway.