Adipocytes utilize sucrose as an energy source-Effect of different carbohydrates on adipocyte differentiation

Adipose tissue is a complex and heterogenic tissue exhibiting high variability and appears to have multiple functions, especially in metabolic regulation. Change in carbohydrate source is reported to have a profound effect in the regular functioning of adipocytes. Here, we analyzed the role of two monosaccharides namely, glucose (5.2 and 25 nM), galactose (25 mM), and two disaccharides namely, lactose and sucrose (both at 25 mM) in the adipocyte differentiation process and its utilization by adipocytes as an energy source. The change in cell morphology, adipocyte-specific gene expression, and protein levels were analyzed at three different time points: 2, 6, and 48 hr. Oil Red O staining at Day 8 of differentiation showed that no other carbohydrates were able to increase lipid content as better as 25 mM glucose. Gene expression pattern was altered by the change in glucose concentration and sucrose was able to mimic the effect of glucose even though, the lipid synthesis was solely promoted by high glucose levels. Galactose and lactose did not show any effect in promoting adipocyte differentiation. The expression of PPAR γ was high in the presence of sucrose and galactose, possibly of adipogenic cocktail in enhancing the expression rather than the effect of carbohydrate. Acarbose, a potent glucosidase inhibitor was able to inhibit the lipid content in adipocytes grown with sucrose as a carbohydrate source and shows the possibility of its direct utilization. Lactate production by cells upon differentiation also proved the possible uptake of glucose after sucrose cleavage.