title: Enhanced leptin sensitivity, reduced adiposity, and improved glucose homeostasis in mice lacking exchange protein directly activated by cyclic AMP isoform 1.
abstract: The prototypic second messenger cyclic AMP (cAMP) is essential for controlling cellular metabolism, including glucose and lipid homeostasis. In mammals, the majority of cAMP functions are mediated by cAMP-dependent protein kinase (PKA) and exchange proteins directly activated by cAMP (Epacs). To explore the physiological functions of Epac1, we generated Epac1 knockout mice. Here we report that Epac1 null mutants have reduced white adipose tissue and reduced plasma leptin levels but display heightened leptin sensitivity. Epac1-deficient mice are more resistant to high-fat diet-induced obesity, hyperleptinemia, and glucose intolerance. Furthermore, pharmacological inhibition of Epac by use of an Epac-specific inhibitor reduces plasma leptin levels in vivo and enhances leptin signaling in organotypic hypothalamic slices. Taken together, our results demonstrate that Epac1 plays an important role in regulating adiposity and energy balance.
authors.affiliation: Department of Pharmacology and Toxicology, Sealy Center for Structural Biology and Molecular Biophysics, The University of Texas Medical Branch, Galveston, Texas, USA.
authors.forename: Jingbo
authors.initials: J
authors.lastname: Yan
authors.forename: Fang C
authors.initials: FC
authors.lastname: Mei
authors.forename: Hongqiang
authors.initials: H
authors.lastname: Cheng
authors.forename: Dieu Hung
authors.initials: DH
authors.lastname: Lao
authors.forename: Yaohua
authors.initials: Y
authors.lastname: Hu
authors.forename: Jingna
authors.initials: J
authors.lastname: Wei
authors.forename: Igor
authors.initials: I
authors.lastname: Patrikeev
authors.forename: Dapeng
authors.initials: D
authors.lastname: Hao
authors.forename: Sonja J
authors.initials: SJ
authors.lastname: Stutz
authors.forename: Kelly T
authors.initials: KT
authors.lastname: Dineley
authors.forename: Massoud
authors.initials: M
authors.lastname: Motamedi
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Hommel
authors.forename: Kathryn A
authors.initials: KA
authors.lastname: Cunningham
authors.forename: Ju
authors.initials: J
authors.lastname: Chen
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Cheng
mesh_terms: D052436:Adipose Tissue, White / Q000378:metabolism; D050154:Adiposity / Q000235:genetics*; D000818:Animals; D000242:Cyclic AMP / Q000378:metabolism*; D059305:Diet, High-Fat / Q000009:adverse effects; D055786:Gene Knockout Techniques; D005947:Glucose / Q000378:metabolism*; D005951:Glucose Tolerance Test; D020662:Guanine Nucleotide Exchange Factors / Q000235:genetics*; D020738:Leptin / Q000097:blood / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009765:Obesity / Q000209:etiology / Q000235:genetics; D015398:Signal Transduction; D015430:Weight Gain
chemical_list: C482601:Epac protein, mouse; D020662:Guanine Nucleotide Exchange Factors; D020738:Leptin; D000242:Cyclic AMP; D005947:Glucose