Soybean diet modulates acetyl-coenzyme A carboxylase expression in livers of rats recovering from early-life malnutrition

Abstract

Objective The present study evaluated the effect of nutritional recovery with a soybean diet on the gene and protein expressions and protein phosphorylation of several enzymes and transcription factors involved in hepatic lipid metabolism. Methods Rats from mothers fed with 17% or 6% protein (casein) during pregnancy and lactation were maintained with a 17% casein (CC and LC groups) or soybean (CS and LS groups) diet and with a 6% casein (LL group) diet until 90 d of life. Results The soybean diet enhanced serum insulin levels but decreased body and liver weights and hepatic lipid and glycogen concentrations. Liver peroxisome proliferator receptor-α mRNA abundance was higher in the LS and CS groups than in the LC and CC groups, but the protein content was similar in all groups. Hepatic acetyl-coenzyme A carboxylase (ACC)-α and ACCβ mRNA expression was markedly lower in the LS and CS rats than in the LC and CC rats. ACC protein expression was lower in the CS group than in the CC, LC, and LS groups. Phospho-[Ser 79]2-ACC content was similar in the CS, LC, and LS groups and lower than the CC group. In the CS rats this reduction paralleled the decrease in total ACC protein. Messenger RNA and protein expression of sterol regulatory element-binding protein 1c, adenosine monophosphate-activated protein kinase, and phospho-[Thr 172]-adenosine monophosphate-activated protein kinase was not modified by the soybean diet. Conclusion Thus, the soybean diet reduced the liver lipid concentration through downregulation of the ACC gene and protein expressions rather than by phosphorylation status, which possibly resulted in decreased lipogenesis and increased β-oxidation.