Effect of human recombinant leptin on lipid handling by fully differentiated Caco-2 cells

It has been established that leptin displays a number of effects on periphe ral tissues. We have investigated the effect of the hormone on lipid synthe sis, apolipoprotein biogenesis and lipoprotein secretion in Caco-2 cells. I mmunocytochemistry revealed the presence of leptin receptors (Ob-Rb) on the basolateral membrane. Incubation of cells with 200 nM leptin resulted in a decreased export of triglycerides in the basolateral medium without affect ing monoglyceride, diglyceride and cholesterol ester lipid classes. It also significantly reduced the output of de novo-synthesized apolipoprotein (Ap o)B-100 and ApoB-48 as well as that of newly formed chylomicrons and of low -density lipoproteins. It also enhanced that of ApoA-I, ApoA-IV and ApoE. O ur results support the hypothesis that leptin can affect energy balance at the gut level by reducing lipid release into the circulation. (C) 2001 Publ ished by Elsevier Science B.V. on behalf of the Federation of European Bioc hemical Societies.