title: Trans-cinnamic acid increases adiponectin and the phosphorylation of AMP-activated protein kinase through G-protein-coupled receptor signaling in 3T3-L1 adipocytes.
abstract: Adiponectin and intracellular 5'adenosine monophosphate-activated protein kinase (AMPK) are important modulators of glucose and fat metabolism. Cinnamon exerts beneficial effects by improving insulin sensitivity and blood lipids, e.g., through increasing adiponectin concentrations and AMPK activation. The underlying mechanism is unknown. The Gi/Go-protein-coupled receptor (GPR) 109A stimulates adiponectin secretion after binding its ligand niacin. Trans-cinnamic acid (tCA), a compound of cinnamon is another ligand. We hypothesize whether AMPK activation and adiponectin secretion by tCA is transmitted by GPR signaling. Differentiated 3T3-L1 cells were incubated with pertussis toxin (PTX), an inhibitor of G(i)/G(o)-protein-coupling, and treated with different tCA concentrations. Treatment with tCA increased adiponectin and the pAMPK/AMPK ratio (p ≤ 0.001). PTX incubation abolished the increased pAMPK/AMPK ratio and adiponectin secretion. The latter remained increased compared to controls (p ≤ 0.002). tCA treatment stimulated adiponectin secretion and AMPK activation; the inhibitory effect of PTX suggests GPR is involved in tCA stimulated signaling.
authors.affiliation: Institute of Animal Science, Physiology & Hygiene Unit, University of Bonn, Katzenburgweg 7-9, Bonn 53115, Germany. christina.kopp@uni-bonn.de.
authors.forename: Christina
authors.initials: C
authors.lastname: Kopp
authors.affiliation: Institute of Animal Science, Physiology & Hygiene Unit, University of Bonn, Katzenburgweg 7-9, Bonn 53115, Germany. spsingh@uni-bonn.de.
authors.forename: Shiva P
authors.initials: SP
authors.lastname: Singh
authors.affiliation: Institute of Animal Science, Physiology & Hygiene Unit, University of Bonn, Katzenburgweg 7-9, Bonn 53115, Germany. petra.regenhard@lohmann.de.
authors.forename: Petra
authors.initials: P
authors.lastname: Regenhard
authors.affiliation: Institute of Animal Science, Physiology & Hygiene Unit, University of Bonn, Katzenburgweg 7-9, Bonn 53115, Germany. ute-mueller@uni-bonn.de.
authors.forename: Ute
authors.initials: U
authors.lastname: Müller
authors.affiliation: Institute of Animal Science, Physiology & Hygiene Unit, University of Bonn, Katzenburgweg 7-9, Bonn 53115, Germany. sauerwein@uni-bonn.de.
authors.forename: Helga
authors.initials: H
authors.lastname: Sauerwein
authors.affiliation: Institute of Animal Science, Physiology & Hygiene Unit, University of Bonn, Katzenburgweg 7-9, Bonn 53115, Germany. mielenz@fbn-dummerstorf.de.
authors.forename: Manfred
authors.initials: M
authors.lastname: Mielenz
mesh_terms: D041721:3T3-L1 Cells; D055372:AMP-Activated Protein Kinases / Q000378:metabolism*; D017667:Adipocytes / Q000166:cytology / Q000378:metabolism; D052242:Adiponectin / Q000378:metabolism*; D000818:Animals; D002934:Cinnamates / Q000494:pharmacology*; D007536:Isomerism; D051379:Mice; D037342:Pertussis Toxin / Q000633:toxicity; D010766:Phosphorylation / Q000187:drug effects; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects*
chemical_list: D052242:Adiponectin; D002934:Cinnamates; D043562:Receptors, G-Protein-Coupled; C029010:cinnamic acid; D037342:Pertussis Toxin; D055372:AMP-Activated Protein Kinases