Low Lysine Treatment Increases Adipogenic Potential of Bovine Intramuscular Preadipocytes

The molecular mechanism of adipocyte differentiation has been well documented. However, the effect of specific nutrients such as lysine on adipocyte differentiation is poorly understood especially in ruminant animals. Therefore, the aim of the present study was to elucidate the influence of lysine on adipocyte differentiation and adipogenic genes in cultured bovine preadipocytes. The preadipocytes were treated with different concentrations of lysine (40, 160, 320 mg/L) or troglitazone (10 mu M) for 2 days and then subsequently cultured in differentiation medium until day 6. Expression levels of C/EBP alpha were significantly higher (p<0.001) in 40 and 160 mg/L lysine-treated cells compared to 320 mg/L treatment. Though there was an increasing trend in PPAR gamma expression levels with the decreasing lysine concentration, the results were not significant. The preadipocyte factor (pref-1), expression significantly (p<0.001) reduced with decreasing lysine concentration. The Oil red O staining results were better in 40 mg/L treated cells compared to 160 and 320 mg/L lysine treated cells. Our overall results indicate that insufficient supply of lysine increases the adipogenic potential in bovine intramuscular preadipocytes.