The Research Of Tumor Necrosis Factor-α On RBP4 Secreted By Mature Adipocytes

PART ONE:THE TUMOR NECROSIS FACTOR–αINHIBITS RETINOL BINDING PROTEIN 4 SECRETION IN MATURE 3T3-L1 ADIPOCYTESObjective: To explore the effects of tumor necrosis factor-α(TNF-α) on retinol binding protein 4 (RBP4) secreted by mature 3T3-L1 adipocytes in-vitro.Methods: 3T3-L1 preadipocytes were cultured and differentiated into the mature adipocytes after 2 days of confluenence. Recombinant TNF-αat different concentrations was added to the culture medium of fully differentiated adipocytes. Total protein of RBP4 secreted by these adipocytes was evaluated by radioimmunoassay (RIA) at various times.Results: 1.Treatment of mature 3T3-L1 adipocytes with TNF-αat different concentrations (0.2, 1.0, 5.0, 10ng/ml) decreased RBP4 secretion. The inhibitive effect of TNF-αon RBP4 was in dose dependent manner. The level of RBP4 decreased along with the elevated TNF-αconcentration in the culture medium. 2.The RBP4 secretion in all experiment groups had a decreasing tread at different time points, but there was no statistical difference in each group. 3.Regression analysis indicated TNF-αhad significant associations with RBP4.Conclusions: TNF-αinhibits mature adipocytes RBP4 secretion in-vitro in dose-response effects, but there is no time-response effects. PART TWO:THE RELATION BETWEEN PGC-1αAND RBP4 SECRETED BY MATURE 3T3-L1 ADIPOCYTESObjective: To explore the effects of Peroxisome proliferator-activated receptor-gamma coactivator-1α(PGC-1α)and PGC-1αmixed with TNF-αon retinol binding protein 4 (RBP4) secreted by mature 3T3-L1 adipocytes in-vitro.Methods: 3T3-L1 preadipocytes were cultured and differentiated into the mature adipocytes after 2 days of confluenence. Recombinant PGC-1αadenovirus, control virus, recombinant TNF-α(10ng/ml), PGC-1αadenovirus mixed with TNF-α(10ng/ml) were added to the culture medium of fully differentiated adipocytes. Total protein of RBP4 secreted by these adipocytes was evaluated by radioimmunoassay (RIA) for 24h after.Results: 1. Treatment of mature 3T3-L1 adipocytes with all these different interventions resulted in the decreasion of RBP4 secretion. 2. Both of the control virus and recombinant PGC-1αadenovirus groups had an inhibitive effect on RBP4, but there's no statistical difference in the two groups. 3.There's no differences between the groups of TNF-αintervention and PGC-1αmixed with TNF-αon the effects of reduction of RBP4 secretion. 4. There's statistical difference in the two groups between TNF-αand virus intervention groups.Conclusions: PGC-1αhas no effect on RBP4 secreted by mature 3T3-L1 adipocytes while TNF-αcan inhibite the protein from adipocytes , and they have no interaction with each other.