N-acetylcysteine inhibits kinase phosphorylation during 3T3-L1 adipocyte differentiation.

OBJECTIVES

Reports investigating the effects of antioxidants on obesity have provided contradictory results. We have previously demonstrated that treatment with the antioxidant N-acetylcysteine (NAC) inhibits cellular triglyceride (Tg) accumulation as well as total cellular monoamine oxidase A (MAOA) expression in 3T3-L1 mature adipocytes (Calzadilla et al., Redox Rep. 2013;210-218). Here we analyzed the role of NAC on adipogenic differentiation pathway.

METHODS

Assays were conducted using 3T3-L1 preadipocytes (undifferentiated cells: CC), which are capable of differentiating into mature adipocytes (differentiated cells: DC). We studied the effects of different doses of NAC (0.01 or 1 mM) on DC, to evaluate cellular expression of phospho-JNK½ (pJNK½), phospho-ERK½ (pERK½) and, mitochondrial expression of citrate synthase, fumarate hydratase and MAOA.

RESULTS

Following the differentiation of preadipocytes, an increase in the expression levels of pJNK½ and pERK½ was observed, together with mitotic clonal expansion (MCE). We found that both doses of NAC decreased the expression of pJNK½ and pERK½. Consistent with these results, NAC significantly inhibited MCE and modified the expression of different mitochondrial proteins.

DISCUSSION

Our results suggested that NAC could inhibit Tg and mitochondrial protein expression by preventing both MCE and kinase phosphorylation.