Exogenous Lipocalin 2 Facilitates the Upregulation Thermogenic and Beige/Browning Markers in Murine White Adipocytes

Lipocalin2 (Lcn2) belongs to a small molecular weight lipocalin subfamily secretary proteins that bind to small hydrophobic molecules. Recent studies have Lcn2 highly upregulated by adipocytes and categorized as a new adipokine with a role in innate immunity and metabolic disorders including obesity. However, the exact role Lcn2 plays in the mediation and progression of obesity has yet to be elucidated. Herein we have investigated the role of exogenous Lcn2 in inducing the beiging/browning of white adipocytes in vitro using 3T3L1 pre and mature murine adipocyte cell line. Treatment with exogenous recombinant Lcn2 (rec-Lcn2) resulted in up-regulation of thermogenic and beige/brown markers (UCP1, PGC1α, PPARγ, PRDM16, ZIC-1 and TBX1). Additionally, mitochondrial activity was increased through Lcn2 exposure in 3T3L1 cells. Further, Lcn2 treatment to pre-adipocytes resulted in attenuation of adipogenesis via the inhibition of lipid accumulation. These results suggest that Lcn2 as a naturally occurring adipokine and may serve as an anti-obesity agent during the development and transdifferentiation of adipocytes and could be a potential target to attenuate/prevent the obesity.