On Wednesday May 23rd Dr Karsten Kristiansen of the Department of Biology at the University of Copenhagen will be presenting a talk titled: “Transdifferentiation of white into brown adipose tissue requires cyclooxygenases” at a special seminar at UC Davis.
Cyclooxygenases (COXs) are the rate-limiting enzymes in prostaglandin synthesis and important in inflammatory responses. The COXs have also been implicated in the control of adipogenesis, and a variety of prostaglandins is produced in adipose tissues. However, their specific roles in adipose tissues are not yet elucidated. Here we demonstrate a concomitant induction of COX2 and UCP1 in inguinal white adipose tissue upon cold exposure. Our findings that cold-induced UCP1 expression in inguinal white, but not interscapular brown adipose tissue, was attenuated in COX2 KO mice and in wild type mice treated with a COX-inhibitor, suggest a role of COX2 in regulation of UCP1 expression during transdifferentiation. The importance of COX-activity and prostaglandins in mediating UCP1 induction is underscored by our finding that UCP1 expression can be induced by forced expression of the COXs and injection of a stable PGE2-analog. Finally, we show that inhibition of COXs attenuated diet-induced UCP1 expression and increased energy-efficiency in obesity-resistant mice providing further support for a role of COXs in the control of energy balance and obesity development.
Karsten Kristiansen is Professor of Molecular Biology and head of the Department of Biology, University of Copenhagen. The seminar will take place on Wednesday May 25, 2011 from 3:00-4:00pm at the WHNRC Conference Room #121 at UC Davis