Chronic TNFα and cAMP pre-treatment of human adipocytes alter HSL, ATGL and perilipin to regulate basal and stimulated lipolysis

We examined the effects of chronic TNF alpha and dibutyryl-cAMP (Db-cAMP) pre-treatment on the lipolytic machinery of human hMADS adipocytes. TNF alpha decreased adipose triglyceride lipase (ATGL) and hormone-sensitive lipase (HSL) protein content and triglycerides (TG)-hydrolase activity but increased basal lipolysis due to a marked reduction in perilipin (PLIN) protein content. Conversely, Db- cAMP increased ATGL and HSL protein content but prevented PLIN phosphorylation, the net result being accentuated basal lipolysis. In forskolin-stimulated conditions, TNF alpha and Db- cAMP pre-treatment decreased stimulated TG-hydrolase activity and impaired PLIN phosphorylation. Together, this resulted in a severely attenuated response to forskolin-stimulated lipolysis. (C) 2009 Federation of European Biochemical Societies. Published by Elsevier B. V. All rights reserved.