The effect of TNF-α on rat pancreatic islet cells

Objective: To study the effect and mechanism of TNF-α on apoptosis of primary rat pancreatic islet cells.Methods: Pancreatic islet cells were obtained by Collagenase P digestion of SD rat pancreas and purified by Ficoll-400 density gradient kit. Cells were divided into four groups and treated with or without TNF-α at increasing doses( 0,10,30,50ng / ml) for 24 hours. Cell apoptosis was evaluated by TUNEL method; the mRNA expression Bcl-2 and Bax was measured by semiquantitive RT-PCR. Results: 10 ng / ml TNF-α did not induce a significant increase in the percentage of apoptotic cells( P 0. 05),30 ng / ml and 50 ng / ml TNF-α significantly increased the percentage of apoptotic cells,compared with control in a dose-dependent manner( P 0. 05). The level of Bcl-2 mRNA slightly increased in cells after the treatment with 10 ng / ml TNF-α,but significantly decreased in cells after the treatment with 30 ~ 50 ng / ml TNF-α,compared with control cells. Conclusion: In vitro,TNF-α dose- dependently induces apoptosis in pancreatic islet cell. The possible mechanisms may be done through the upregulation of Bax and the downregulation of Bcl-2 expression.