Glutamine is required for 3T3 L1 adipocyte differentiation and lipid accumulation

Differentiation of 3T3 L1 cells into adipocytes, as determined by lipid accumulation, is dependent on glutamine. The process can be blocked by methionine sulfoximine (MSO), an inhibitor of glutamine synthesis, or diazonorleucine (DON), an inhibitor of glutamine metabolism. MSO added at anytime up to 48h after the initiation of differentiation completely abolished lipid accumulation by day 7. Addition of MSO at 60–144h resulted in progressively more lipid accumulation but this never reached control levels. Furthermore, the rates of lipid accumulation from days 7–11 were less than observed in control cells. Similarly, there was no lipid accumulation when DON was added up to 36h. Addition of DON at 48–144h resulted in progressively more lipid accumulation but always below control levels. The rates of lipid accumulation in the presence of DON were also lower than in control cells, particularly from day 9 through 11. The results show that glutamine metabolism is required throughout 3T3 L1 cell differentiation and that this is particularly important for maximal rates of lipid accumulation in fully differentiated cells. Supported by the NJ Agricultural Experiment Station Project 14161.