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Guilherme A, Rowland LA, Wang H, Czech MP. The adipocyte supersystem of insulin and cAMP signaling. Trends Cell Biol 2023; 33:340-354. [PMID: 35989245 PMCID: PMC10339226 DOI: 10.1016/j.tcb.2022.07.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 07/27/2022] [Accepted: 07/28/2022] [Indexed: 01/28/2023]
Abstract
Adipose tissue signals to brain, liver, and muscles to control whole body metabolism through secreted lipid and protein factors as well as neurotransmission, but the mechanisms involved are incompletely understood. Adipocytes sequester triglyceride (TG) in fed conditions stimulated by insulin, while in fasting catecholamines trigger TG hydrolysis, releasing glycerol and fatty acids (FAs). These antagonistic hormone actions result in part from insulin's ability to inhibit cAMP levels generated through such G-protein-coupled receptors as catecholamine-activated β-adrenergic receptors. Consistent with these antagonistic signaling modes, acute actions of catecholamines cause insulin resistance. Yet, paradoxically, chronically activating adipocytes by catecholamines cause increased glucose tolerance, as does insulin. Recent results have helped to unravel this conundrum by revealing enhanced complexities of these hormones' signaling networks, including identification of unexpected common signaling nodes between these canonically antagonistic hormones.
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Affiliation(s)
- Adilson Guilherme
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA.
| | - Leslie A Rowland
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA
| | - Hui Wang
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA
| | - Michael P Czech
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA.
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Liu K, Jin X, Zhang X, Lian H, Ye J. The mechanisms of nucleotide actions in insulin resistance. J Genet Genomics 2022; 49:299-307. [DOI: 10.1016/j.jgg.2022.01.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 01/23/2022] [Accepted: 01/24/2022] [Indexed: 12/14/2022]
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Zhang Q, Cai Z, Lhomme M, Sahana G, Lesnik P, Guerin M, Fredholm M, Karlskov-Mortensen P. Inclusion of endophenotypes in a standard GWAS facilitate a detailed mechanistic understanding of genetic elements that control blood lipid levels. Sci Rep 2020; 10:18434. [PMID: 33116219 PMCID: PMC7595098 DOI: 10.1038/s41598-020-75612-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 10/15/2020] [Indexed: 12/13/2022] Open
Abstract
Dyslipidemia is the primary cause of cardiovascular disease, which is a serious human health problem in large parts of the world. Therefore, it is important to understand the genetic and molecular mechanisms that regulate blood levels of cholesterol and other lipids. Discovery of genetic elements in the regulatory machinery is often based on genome wide associations studies (GWAS) focused on end-point phenotypes such as total cholesterol level or a disease diagnosis. In the present study, we add endophenotypes, such as serum levels of intermediate metabolites in the cholesterol synthesis pathways, to a GWAS analysis and use the pig as an animal model. We do this to increase statistical power and to facilitate biological interpretation of results. Although the study population was limited to ~ 300 individuals, we identify two genome-wide significant associations and ten suggestive associations. Furthermore, we identify 28 tentative associations to loci previously associated with blood lipids or dyslipidemia associated diseases. The associations with endophenotypes may inspire future studies that can dissect the biological mechanisms underlying these previously identified associations and add a new level of understanding to previously identified associations.
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Affiliation(s)
- Qianqian Zhang
- Bioinformatics Research Centre (BiRC), Aarhus University, C.F.Møllers Allé 8, 8000, Aarhus C, Denmark
| | - Zexi Cai
- Center for Quantitativ Genetics and Genomics, Aarhus University, Blichers Allé 20, 8830, Tjele, Danmark
| | - Marie Lhomme
- ICANalytics, Institute of Cardiometabolism and Nutrition (ICAN), 47-83 boulevard de l'hôpital, 75013, Paris, France
| | - Goutam Sahana
- Center for Quantitativ Genetics and Genomics, Aarhus University, Blichers Allé 20, 8830, Tjele, Danmark
| | - Philippe Lesnik
- Unité de Recherche sur les maladies cardiovasculaires, le métabolisme et la nutrition, INSERM UMR_S 1166, ICAN Institute of Cardiometabolism & Nutrition, Faculté de Médecine Sorbonne Université, Sorbonne Université, 4ème étage, Bureau 421,91, boulevard de l'Hôpital, 75634, Paris Cedex 13, France
| | - Maryse Guerin
- Unité de Recherche sur les maladies cardiovasculaires, le métabolisme et la nutrition, INSERM UMR_S 1166, ICAN Institute of Cardiometabolism & Nutrition, Faculté de Médecine Sorbonne Université, Sorbonne Université, 4ème étage, Bureau 421,91, boulevard de l'Hôpital, 75634, Paris Cedex 13, France
| | - Merete Fredholm
- Animal Genetics, Bioinformatics and Breeding, Department of Veterinary and Animal Sciences, University of Copenhagen, Gronnegaardsvej 3, 1870, Frederikgsberg C, Denmark
| | - Peter Karlskov-Mortensen
- Animal Genetics, Bioinformatics and Breeding, Department of Veterinary and Animal Sciences, University of Copenhagen, Gronnegaardsvej 3, 1870, Frederikgsberg C, Denmark.
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Getz M, Rangamani P, Ghosh P. Regulating cellular cyclic adenosine monophosphate: "Sources," "sinks," and now, "tunable valves". WILEY INTERDISCIPLINARY REVIEWS-SYSTEMS BIOLOGY AND MEDICINE 2020; 12:e1490. [PMID: 32323924 DOI: 10.1002/wsbm.1490] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Revised: 01/31/2020] [Accepted: 03/31/2020] [Indexed: 12/16/2022]
Abstract
A number of hormones and growth factors stimulate target cells via the second messenger pathways, which in turn regulate cellular phenotypes. Cyclic adenosine monophosphate (cAMP) is a ubiquitous second messenger that facilitates numerous signal transduction pathways; its production in cells is tightly balanced by ligand-stimulated receptors that activate adenylate cyclases (ACs), that is, "source" and by phosphodiesterases (PDEs) that hydrolyze it, that is, "sinks." Because it regulates various cellular functions, including cell growth and differentiation, gene transcription and protein expression, the cAMP signaling pathway has been exploited for the treatment of numerous human diseases. Reduction in cAMP is achieved by blocking "sources"; however, elevation in cAMP is achieved by either stimulating "source" or blocking "sinks." Here we discuss an alternative paradigm for the regulation of cellular cAMP via GIV/Girdin, the prototypical member of a family of modulators of trimeric GTPases, Guanine nucleotide Exchange Modulators (GEMs). Cells upregulate or downregulate cellular levels of GIV-GEM, which modulates cellular cAMP via spatiotemporal mechanisms distinct from the two most often targeted classes of cAMP modulators, "sources" and "sinks." A network-based compartmental model for the paradigm of GEM-facilitated cAMP signaling has recently revealed that GEMs such as GIV serve much like a "tunable valve" that cells may employ to finetune cellular levels of cAMP. Because dysregulated signaling via GIV and other GEMs has been implicated in multiple disease states, GEMs constitute a hitherto untapped class of targets that could be exploited for modulating aberrant cAMP signaling in disease states. This article is categorized under: Models of Systems Properties and Processes > Mechanistic Models Biological Mechanisms > Cell Signaling.
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Affiliation(s)
- Michael Getz
- Chemical Engineering Graduate Program, University of California San Diego, La Jolla, California, USA
| | - Padmini Rangamani
- Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, California, USA
| | - Pradipta Ghosh
- Department of Medicine, University of California San Diego, La Jolla, California, USA
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, California, USA
- Moores Comprehensive Cancer Center, University of California San Diego, La Jolla, California, USA
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