Endogenous CSE/H2 S system mediates TNF-α-induced insulin resistance in 3T3-L1 adipocytes

Tumour necrosis factor-α (TNF- α)is a major contributor to the pathogenesis of insulin resistance associated with obesity and type 2 diabetes. It has been found that endogenous hydrogen sulfide (H2 S) contributes to the pathogenesis of diabetes. We have hypothesized that TNF-α-induced insulin resistance is involved in endogenous H2 S generation. The aim of the present study is to investigate the role of endogenous H2 S in TNF-α-induced insulin resistance by studying 3T3-L1 adipocytes. We found that treatment of 3T3-L1 adipocytes with TNF-α leads to deficiency in insulin-stimulated glucose consumption and uptake and increase in endogenous H2 S generation. We show that cystathionine γ-lyase (CSE) is catalysed in 3T3-L1 adipocytes to generate H2 S and that CSE expression and activity are upregulated by TNF-α treatment. Inhibited CSE by its potent inhibitors significantly attenuates TNF-α-induced insulin resistance in 3T3-L1 adipocytes, whereas H2 S treatment of 3T3-L1 adipocytes impairs insulin-stimulated glucose consumption and uptake. These data indicate that endogenous CSE/H2 S system contributes to TNF-α-caused insulin resistance in 3T3-L1 adipocytes. Our findings suggest that modulation of CSE/H2 S system is a potential therapeutic avenue for insulin resistance.