116-OR: Lipocalin-Type Prostaglandin D2 Synthase Depletion Induces Adipose Tissue Dysfunction in Response to High-Fat Diet

Adipose tissue dysfunction is the primary defect in obesity which contributes to the development of dyslipidemia, insulin resistance, cardiovascular diseases, type 2 diabetes, nonalcoholic fatty liver disease and some cancers. Previous study from our lab implicated the role of lipocalin-type prostaglandin D2 synthase (L-PGDS) in glucose intolerance and atherosclerosis. Our lab also showed the development of NAFLD in L-PGDS knockout mice on both low fat and high fat diet. In the present study, we examined the role of L-PGDS in adipose tissue in response to high fat diet. We found decreased expression of L-PGDS in visceral and subcutaneous white adipose tissue (WAT) of C57BL/6 mice after 12 weeks on high fat diet (HFD). Our study showed increased fat content in L-PGDS KO mice as compared to control C57BL/6 mice after 14 weeks on HFD. Histological analysis showed hypertrophied adipocytes in visceral WAT of L-PGDS KO mice as compared to control mice. Furthermore, we found increased expression of the lipogenesis genes LXRα, SREBP-1c and FAS in visceral WAT of L-PGDS KO mice after 14 weeks on HFD. L-PGDS KO mice showed reduced gene expression of adiponectin and PPARγ in visceral WAT on HFD. The plasma adiponectin level was also decreased in L-PGDS KO mice. We conclude that absence of L-PGDS has a deleterious effect on adipose tissue functioning which further reduces insulin sensitivity in adipose tissue. Thus, our study suggests L-PGDS as a novel therapeutic target for the treatment of obesity-associated metabolic syndrome.