title: QRFP-43 inhibits lipolysis by preventing ligand-induced complex formation between perilipin A, caveolin-1, the catalytic subunit of protein kinase and hormone-sensitive lipase in 3T3-L1 adipocytes.
abstract: QRFP (RFamide) peptides are neuropeptides involved in food intake and adiposity regulation in rodents. We have previously shown that QRFP-43 (43RFa) and QRFP-26 (26RFa) inhibited isoproterenol (ISO)-induced lipolysis in adipocytes. However, the antilipolytic signaling pathways activated by QRFP peptides have not been investigated. In the present study, 3T3-L1 adipocytes were used to identify the main pathways involved in QRFP-43 decreasing ISO-induced lipolysis. Our results show that QRFP-43 reduced ISO-induced phosphorylation of perilipin A (PLIN) and hormone-sensitive lipase (HSL) on Ser660 by 43 and 25%, respectively, but increased Akt phosphorylation by 44%. However, the inhibition of phosphodiesterase 3B (PDE3B), a regulator of lipolysis activated by Akt, did not reverse the antilipolytic effect of QRFP-43. PDE3B inhibition reversed the decrease of Ser660 HSL phosphorylation associated with QRFP-43 antilipolytic effect. QRFP-43 also prevented PKC activation and ISO-induced Src kinases activation leading to the inhibition of the caveolin-1 (CAV-1) translocation on lipid droplets. Indeed, QRFP-43 attenuated phorbol 12-myristate 13-acetate-induced lipolysis and ISO-induced extracellular signal-regulated and Src kinases by 28, 37 and 48%, respectively. The attenuation of ISO-induced lipolysis by QRFP-43 was associated with a decrease of phosphorylated Ser660 HSL, PKA-catalytic (PKA-c) subunit and CAV-1 translocation on lipid droplets by 37, 50 and 46%, respectively. The decrease in ISO-induced CAV-1 and PKA-c translocation was associated with a reduction of PLIN phosphorylation by 44% in QRFP-43-treated adipocytes. These results suggest that QRFP-43 attenuated ISO-induced lipolysis by preventing the formation of an active complex on lipid droplets and the activation of Src kinases and PKC.
authors: Faculty of Pharmacy, Université de Montréal C.P. 6128, Succursale Centre-Ville, Montréal, Québec H3C 3J7, Canada.
authors: Mukandila
authors: M
authors: Mulumba
authors: Laboratory of Molecular and Cellular Endocrinology, Department of Medical Sciences, University of Turin, Corso Dogliotti 14, Turin 10126, Italy.
authors: Riccarda
authors: R
authors: Granata
authors: Faculty of Pharmacy, Université de Montréal C.P. 6128, Succursale Centre-Ville, Montréal, Québec H3C 3J7, Canada.
authors: Sylvie
authors: S
authors: Marleau
authors: Faculty of Pharmacy, Université de Montréal C.P. 6128, Succursale Centre-Ville, Montréal, Québec H3C 3J7, Canada. Electronic address: huy.ong@umontreal.ca.
authors: Huy
authors: H
authors: Ong
mesh_terms: D041721:3T3-L1 Cells; D017667:Adipocytes / Q000187:drug effects* / Q000201:enzymology; D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism*; D051242:Caveolin 1 / Q000378:metabolism*; D054751:Cyclic AMP-Dependent Protein Kinase Catalytic Subunits / Q000378:metabolism*; D054684:Cyclic Nucleotide Phosphodiesterases, Type 3 / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D036341:Intercellular Signaling Peptides and Proteins; D007545:Isoproterenol / Q000494:pharmacology; D066292:Lipid Droplets / Q000187:drug effects / Q000378:metabolism; D008066:Lipolysis / Q000187:drug effects*; D051379:Mice; D046912:Multiprotein Complexes; D010455:Peptides / Q000494:pharmacology*; D000070778:Perilipin-1; D058987:Phosphodiesterase 3 Inhibitors / Q000494:pharmacology; D010750:Phosphoproteins / Q000378:metabolism*; D010766:Phosphorylation; D011493:Protein Kinase C / Q000378:metabolism; D021381:Protein Transport; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism; D012694:Serine; D015398:Signal Transduction / Q000187:drug effects; D002787:Sterol Esterase / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D019061:src-Family Kinases / Q000378:metabolism
chemical_list: D002352:Carrier Proteins; C495541:Cav1 protein, mouse; D051242:Caveolin 1; D036341:Intercellular Signaling Peptides and Proteins; D046912:Multiprotein Complexes; D010455:Peptides; D000070778:Perilipin-1; D058987:Phosphodiesterase 3 Inhibitors; D010750:Phosphoproteins; C511787:QRFP peptide; C476583:Qrfpr protein, mouse; D043562:Receptors, G-Protein-Coupled; D012694:Serine; D019061:src-Family Kinases; D054751:Cyclic AMP-Dependent Protein Kinase Catalytic Subunits; D011493:Protein Kinase C; D002787:Sterol Esterase; D054684:Cyclic Nucleotide Phosphodiesterases, Type 3; C517293:Pde3b protein, mouse; D007545:Isoproterenol; D013755:Tetradecanoylphorbol Acetate
keywords: Adipocytes; Adrenergic receptors; Caveolins; Lipolysis; Protein kinases; RFamide peptides