Sodium acetate decreases phosphorylation of hormone sensitive lipase in isoproterenol-stimulated 3T3-L1 mature adipocytes

Lipolysis, the process of hydrolysis of stored triacylglycerol into glycerol and non-esterified fatty acids (NEF A), is reported to be reduced by short chain fatty acids (SCFA) but the mechanism of this inhibition is poorly understood. The aim of this study was to measure the phosphorylation at serine residue 563 of hormone sensitive lipase with and without exposure to sodium acetate. Using the 3T3-L1 cell line, we identified that stimulating the cells with isoproterenol increased phosphorylated hormone sensitive lipase (pHSL) expression by 60% compared with the basal state. In the presence of the SCFA acetate in stimulated cells, pHSL decreased by 15% compared with stimulated cells alone. These results were mirrored by the NEF A release from stimulated cells that had significantly decreased in the presence of sodium acetate after 60 min (from 0.53 mu mol mg(-1) protein to 0.41 mu mol mg(-1) protein, respectively, P = 0.004); and 180 min (1.73 mu mol mg(-1) protein to 1.13 mu mol mg(-1) protein, P = 0.020); however, treatment had no effect on glycerol release (P = 0.109). In conclusion, exposure to 4 mM acetate reduced the level of phosphorylation of HSL(SER563) in mature 3T3-L1 adipocytes and led to a significant reduction in NEF A release, although glycerol release was not affected.