Arsenic trioxide inhibites transgenic tumor necrosis factor-α promoter activity in vascular smooth muscle cells and THP-1 monocytes in vitro

Aim This study was to evaluate the effect of arsenic trioxide （As2O3） on the transgenic TNF-α promoter activity in cultured vascular smooth muscle cells （VSMCs） and THP-1 monocytes. Methods Human TNF-α promoter was constructed by reporter gene system and was transiently transfected into VSMCs and THP-1 in vitro. The promoter activity was tested by luciferase activity with or without LPS and Ang Ⅱ stimulation, before and after different dosage of As2O3 treatment. Results 1. TNF-α promoter effectively expressed in VSMCs and THP-1 compared with CMV promoter （58.3% and 80.9%, respectively）. Both LPS and Ang Ⅱ significantly up-regulated TNF-α promoter activity （P〈0.05）. 2. As2O3 significantly inhibited, both intact and LPS/Ang Ⅱ stimulated promoter activity, in a dose dependent manner （P〈0.05）, and in both cell type. Conclusion These results manifested that, the inhibition effect of As2O3 on the activity of human TNF-α promoter indicated its potential inhibition on pro-inflammatory cytokine genes expression at transcriptional level and its potential anti-inflammatory property in the cardiovascular system.

A study on the expressions and the correlation of TGF-β1 and α-SMA in healing process of bile duct trauma

Objective: To explore the formation mechanism of benign biliary stricture. Methods: A model of trauma of common bile duct was established in 28 dogs and then repaired. The anasomosis tissues were taken on the 1st week, 3rd week and the 3rd month, 6th month respectively after operation and examined by using light microscopy and elec-tromicroscopy. Macrophage, TGF-p, and a-SMA were studied immunohistochemically. Results: The mucosal epithelium of common bile duct restored poorly, chronic inflammation lasted for a long time, fibroblasts proliferated actively, extracellular matrix overdeposited; and myofibroblasts functioned actively and existed during the whole healing process. Immunohistochemical test showed a high expression of macrophage, TGF-β1 and a-SMA during healing process lasting a long duration. Macrophages were found in the lamina propria under mucosa, TGF-β1 in the granulation tissue, fibroblasts and endothelial cells of blood vesssels, while a-SMA in the myofiroblasts and smooth muscle tissue. Conclusion: The healing of bile duct is in the mode of overhealing. Myofibroblast is the main cause for contracture of scar and stricture of bile duct. The high expression of macrophage, TGF-β1 and a-SMA is closely related to active proliferation of fibroblasts, extracelluar matrix overdeposition and scar contracture of bile duct.