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Gómez-Hernández A, de las Heras N, Gálvez BG, Fernández-Marcelo T, Fernández-Millán E, Escribano Ó. New Mediators in the Crosstalk between Different Adipose Tissues. Int J Mol Sci 2024; 25:4659. [PMID: 38731880 PMCID: PMC11083914 DOI: 10.3390/ijms25094659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Revised: 04/19/2024] [Accepted: 04/22/2024] [Indexed: 05/13/2024] Open
Abstract
Adipose tissue is a multifunctional organ that regulates many physiological processes such as energy homeostasis, nutrition, the regulation of insulin sensitivity, body temperature, and immune response. In this review, we highlight the relevance of the different mediators that control adipose tissue activity through a systematic review of the main players present in white and brown adipose tissues. Among them, inflammatory mediators secreted by the adipose tissue, such as classical adipokines and more recent ones, elements of the immune system infiltrated into the adipose tissue (certain cell types and interleukins), as well as the role of intestinal microbiota and derived metabolites, have been reviewed. Furthermore, anti-obesity mediators that promote the activation of beige adipose tissue, e.g., myokines, thyroid hormones, amino acids, and both long and micro RNAs, are exhaustively examined. Finally, we also analyze therapeutic strategies based on those mediators that have been described to date. In conclusion, novel regulators of obesity, such as microRNAs or microbiota, are being characterized and are promising tools to treat obesity in the future.
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Affiliation(s)
- Almudena Gómez-Hernández
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad Complutense de Madrid, Plaza Ramón y Cajal, s/n, 28040 Madrid, Spain; (A.G.-H.); (B.G.G.); (T.F.-M.); (E.F.-M.)
| | - Natalia de las Heras
- Departamento de Fisiología, Facultad de Medicina, Universidad Complutense de Madrid, Plaza Ramón y Cajal, s/n, 28040 Madrid, Spain;
| | - Beatriz G. Gálvez
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad Complutense de Madrid, Plaza Ramón y Cajal, s/n, 28040 Madrid, Spain; (A.G.-H.); (B.G.G.); (T.F.-M.); (E.F.-M.)
| | - Tamara Fernández-Marcelo
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad Complutense de Madrid, Plaza Ramón y Cajal, s/n, 28040 Madrid, Spain; (A.G.-H.); (B.G.G.); (T.F.-M.); (E.F.-M.)
| | - Elisa Fernández-Millán
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad Complutense de Madrid, Plaza Ramón y Cajal, s/n, 28040 Madrid, Spain; (A.G.-H.); (B.G.G.); (T.F.-M.); (E.F.-M.)
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III (ISCIII), 28029 Madrid, Spain
| | - Óscar Escribano
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad Complutense de Madrid, Plaza Ramón y Cajal, s/n, 28040 Madrid, Spain; (A.G.-H.); (B.G.G.); (T.F.-M.); (E.F.-M.)
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III (ISCIII), 28029 Madrid, Spain
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Kim CW, Lee JM, Park SW. Divergent roles of the regulatory subunits of class IA PI3K. Front Endocrinol (Lausanne) 2024; 14:1152579. [PMID: 38317714 PMCID: PMC10839044 DOI: 10.3389/fendo.2023.1152579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Accepted: 12/11/2023] [Indexed: 02/07/2024] Open
Abstract
The regulatory subunit of phosphatidylinositol 3-kinase (PI3K), known as p85, is a critical component in the insulin signaling pathway. Extensive research has shed light on the diverse roles played by the two isoforms of p85, namely p85α and p85β. The gene pik3r1 encodes p85α and its variants, p55α and p50α, while pik3r2 encodes p85β. These isoforms exhibit various activities depending on tissue types, nutrient availability, and cellular stoichiometry. Whole-body or liver-specific deletion of pik3r1 have shown to display increased insulin sensitivity and improved glucose homeostasis; however, skeletal muscle-specific deletion of p85α does not exhibit any significant effects on glucose homeostasis. On the other hand, whole-body deletion of pik3r2 shows improved insulin sensitivity with no significant impact on glucose tolerance. Meanwhile, liver-specific double knockout of pik3r1 and pik3r2 leads to reduced insulin sensitivity and glucose tolerance. In the context of obesity, upregulation of hepatic p85α or p85β has been shown to improve glucose homeostasis. However, hepatic overexpression of p85α in the absence of p50α and p55α results in increased insulin resistance in obese mice. p85α and p85β have distinctive roles in cancer development. p85α acts as a tumor suppressor, but p85β promotes tumor progression. In the immune system, p85α facilitates B cell development, while p85β regulates T cell differentiation and maturation. This review provides a comprehensive overview of the distinct functions attributed to p85α and p85β, highlighting their significance in various physiological processes, including insulin signaling, cancer development, and immune system regulation.
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Affiliation(s)
- Cho-Won Kim
- Division of Endocrinology, Boston Children’s Hospital, Boston, MA, United States
- Department of Pediatrics, Harvard Medical School, Boston, MA, United States
| | - Junsik M. Lee
- Division of Endocrinology, Boston Children’s Hospital, Boston, MA, United States
| | - Sang Won Park
- Division of Endocrinology, Boston Children’s Hospital, Boston, MA, United States
- Department of Pediatrics, Harvard Medical School, Boston, MA, United States
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Tsay A, Wang JC. The Role of PIK3R1 in Metabolic Function and Insulin Sensitivity. Int J Mol Sci 2023; 24:12665. [PMID: 37628845 PMCID: PMC10454413 DOI: 10.3390/ijms241612665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 08/04/2023] [Accepted: 08/08/2023] [Indexed: 08/27/2023] Open
Abstract
PIK3R1 (also known as p85α) is a regulatory subunit of phosphoinositide 3-kinases (PI3Ks). PI3K, a heterodimer of a regulatory subunit and a catalytic subunit, phosphorylates phosphatidylinositol into secondary signaling molecules involved in regulating metabolic homeostasis. PI3K converts phosphatidylinositol 4,5-bisphosphate (PIP2) to phosphatidylinositol 3,4,5-triphosphate (PIP3), which recruits protein kinase AKT to the inner leaflet of the cell membrane to be activated and to participate in various metabolic functions. PIK3R1 stabilizes and inhibits p110 catalytic activity and serves as an adaptor to interact with insulin receptor substrate (IRS) proteins and growth factor receptors. Thus, mutations in PIK3R1 or altered expression of PIK3R1 could modulate the activity of PI3K and result in significant metabolic outcomes. Interestingly, recent studies also found PI3K-independent functions of PIK3R1. Overall, in this article, we will provide an updated review of the metabolic functions of PIK3R1 that includes studies of PIK3R1 in various metabolic tissues using animal models, the mechanisms modulating PIK3R1 activity, and studies on the mutations of human PIK3R1 gene.
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Affiliation(s)
- Ariel Tsay
- Metabolic Biology Graduate Program, University of California Berkeley, Berkeley, CA 94720, USA;
- Department of Nutritional Sciences & Toxicology, University of California Berkeley, Berkeley, CA 94720, USA
| | - Jen-Chywan Wang
- Metabolic Biology Graduate Program, University of California Berkeley, Berkeley, CA 94720, USA;
- Department of Nutritional Sciences & Toxicology, University of California Berkeley, Berkeley, CA 94720, USA
- Endocrinology Graduate Program, University of California Berkeley, Berkeley, CA 94720, USA
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Shvalb NF. SHORT Syndrome: an Update on Pathogenesis and Clinical Spectrum. Curr Diab Rep 2022; 22:571-577. [PMID: 36401775 DOI: 10.1007/s11892-022-01495-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/10/2022] [Indexed: 11/21/2022]
Abstract
PURPOSE OF REVIEW This review describes the unique pathogenesis of SHORT syndrome, a rare genetic form of insulin resistance syndrome, and recent advances in understanding the underlying mechanisms. SHORT syndrome results from dysfunction of PI3K, but the mechanisms behind the clinical manifestations are not entirely understood. Elucidating these mechanisms may contribute to the understanding of the roles of insulin signaling and PI3K signaling in humans. There are paucity of data on treatment and outcomes. RECENT FINDINGS The clinical spectrum of the disorder appears wider than previously understood, and overlaps with other clinical syndromes. PI3K malfunction is associated with insulin resistance, decreased lipogenesis, increased energy expenditure, and possible IGF1 resistance. SHORT syndrome may be underdiagnosed, and should be considered in individuals with growth failure, craniofacial dysmorphism, and lipodystrophy. Much is still unknown about the optimal management and long-term outcomes.
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Affiliation(s)
- Naama Fisch Shvalb
- National Center for Childhood Diabetes, The Jesse Z and Sara Lea Shafer Institute for Endocrinology and Diabetes, Schneider Children's Medical Center of Israel, 14 Kaplan St, 49202-35, Petah Tikva, Israel.
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
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Lee JM, Liu R, Park SW. The regulatory subunits of PI3K, p85α and p85β, differentially affect BRD7-mediated regulation of insulin signaling. J Mol Cell Biol 2021; 13:889-901. [PMID: 34751372 PMCID: PMC8800525 DOI: 10.1093/jmcb/mjab073] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 09/15/2021] [Accepted: 09/24/2021] [Indexed: 11/12/2022] Open
Abstract
Bromodomain-containing protein 7 (BRD7) has been shown to interact with the regulatory subunit of phosphatidylinositol 3-kinase (PI3K), p85, in the insulin signaling pathway. Here, we show that upregulation of hepatic BRD7 improves glucose homeostasis even in the absence of either p85 isoform, p85α or p85β. However, BRD7 leads to differential activation of downstream effector proteins in the insulin signaling pathway depending on which isoform of p85 is present. In the presence of only p85α, BRD7 overexpression increases phosphorylation of insulin receptor (IR) upon insulin stimulation, without increasing the recruitment of p85 to IR substrate. Overexpression of BRD7 also increases activation of Akt in response to insulin, but does not affect basal phosphorylation levels of Akt. Meanwhile, the phosphorylation of glycogen synthase kinase 3β (GSK3β) is increased by overexpression of BRD7. On the other hand, in the presence of only p85β, BRD7 overexpression does not affect phosphorylation levels of IR, and Akt phosphorylation is not affected by insulin stimulation following BRD7 upregulation. However, BRD7 overexpression leads to increased basal phosphorylation levels of Akt and GSK3β. These data demonstrate that BRD7’s action on glucose homeostasis does not require the presence of both p85 isoforms, and p85α and p85β have unique roles in insulin signaling in the liver.
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Affiliation(s)
- Junsik M Lee
- Division of Endocrinology, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115 USA
| | - Renyan Liu
- Division of Endocrinology, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115 USA
| | - Sang Won Park
- Division of Endocrinology, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115 USA
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Mig-6 is essential for glucose homeostasis and thermogenesis in brown adipose tissue. Biochem Biophys Res Commun 2021; 572:92-97. [PMID: 34358969 DOI: 10.1016/j.bbrc.2021.07.088] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 07/23/2021] [Accepted: 07/26/2021] [Indexed: 01/06/2023]
Abstract
Brown adipose tissue (BAT) is an anti-obese and anti-diabetic tissue that stimulates energy expenditure in the form of adaptive thermogenesis through uncoupling protein 1 (UCP1). Mitogen-inducible gene-6 (Mig-6) is a negative regulator of epidermal growth factor receptor (EGFR) that interacts with many cellular partners and has multiple cellular functions. We have recently reported that Mig-6 is associated with diabetes and metabolic syndrome. However, its function in BAT is unknown. We generated a brown adipocyte-specific Mig-6 knock-in mouse (BKI) to examine the role of Mig-6 in BAT. Mig-6 BKI mice had improved glucose tolerance on a normal chow diet. Mig-6 BKI mice also revealed activated thermogenesis and the size of the BAT lipid droplets was reduced. Additionally, Mig-6 regulated cAMP-PKA signaling-induced UCP1 expression in brown adipocytes. Taken together, these results demonstrate that Mig-6 affects glucose tolerance and thermogenesis in BAT.
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Fu P, Zhu R, Jia J, Hu Y, Wu C, Cieszczyk P, Holmberg HC, Gong L. Aerobic exercise promotes the functions of brown adipose tissue in obese mice via a mechanism involving COX2 in the VEGF signaling pathway. Nutr Metab (Lond) 2021; 18:56. [PMID: 34082784 PMCID: PMC8176720 DOI: 10.1186/s12986-021-00581-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Accepted: 05/27/2021] [Indexed: 12/18/2022] Open
Abstract
Background High-fat diet (HFD)-induced obesity causes immune cells to infiltrate adipose tissue, leading to chronic inflammation and metabolic syndrome. Brown adipose tissue (BAT) can dissipate the energy produced by lipid oxidation as heat, thereby counteracting obesity. Aerobic exercise activates BAT, but the specific underlying mechanism is still unclear. Methods Male C57BL/6 J mice were divided into a normal diet control group (NC group) and HFD group (H group). After becoming obese, the animals in the H group were subdivided into a control group (HC group) and an exercise group (HE group, with treadmill training). After 4 weeks, the mRNA profile of BAT was determined, and then differentially expressed key genes and pathways were verified in vitro. Results Relative to the NC group, the genes upregulated in the HC group coded mainly for proteins involved in immune system progression and inflammatory and immune responses, while the downregulated genes regulated lipid metabolism and oxidation–reduction. Relative to the HC group, the genes upregulated in the HE group coded for glycolipid metabolism, while those that were downregulated were involved in cell death and apoptosis. VEGF and other signaling pathways were enhanced by aerobic exercise. Interaction analysis revealed that the gene encoding cyclooxygenase 2 (COX2) of the VEGF signaling pathway is central to this process, which was verified by a sympathetic activator (isoprenaline hydrochloride) and COX2 inhibitor (NS-398). Conclusions In mice with HFD-induced obesity, four weeks of aerobic exercise elevated BAT mass and increased the expression of genes related to glycolipid metabolism and anti-inflammatory processes. Several pathways are involved, with COX2 in the VEGF signaling pathway playing a key role.
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Affiliation(s)
- Pengyu Fu
- China Institute of Sport and Health Science, Beijing Sport University, Xinxi Road 48, Haidian District, Beijing, 100084, China.,Department of Physical Education, Northwestern Polytechnical University, West Youyi Road 127, Beilin District, Shaanxi, 710109, China
| | - Rongxin Zhu
- China Institute of Sport and Health Science, Beijing Sport University, Xinxi Road 48, Haidian District, Beijing, 100084, China.,Shanghai Research Institute of Sports Science, Xuhui District, Wuxing Road 87, Shanghai, 200030, China
| | - Jie Jia
- China Institute of Sport and Health Science, Beijing Sport University, Xinxi Road 48, Haidian District, Beijing, 100084, China.,Sport Science College, Beijing Sport University, Xinxi Road 48, Haidian District, Beijing, 100084, China
| | - Yang Hu
- China Institute of Sport and Health Science, Beijing Sport University, Xinxi Road 48, Haidian District, Beijing, 100084, China
| | - Chengjun Wu
- School of Biomedical Engineering, Dalian University of Technology and IC Technology Key Lab of Liaoning, Dalian, 116024, China
| | - Pawel Cieszczyk
- Department of Molecular Biology, Faculty of Physical Education, Gdańsk University of Physical Education and Sport, ul. Kazimierza Górskiego 1, 80-336, Gdańsk, Poland
| | - Hans-Christer Holmberg
- Department of Physiology and Pharmacology, Biomedicum C5, Karolinska Institute, Stockholm, Sweden
| | - Lijing Gong
- China Institute of Sport and Health Science, Beijing Sport University, Xinxi Road 48, Haidian District, Beijing, 100084, China.
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Kwok A, Zvetkova I, Virtue S, Luijten I, Huang-Doran I, Tomlinson P, Bulger DA, West J, Murfitt S, Griffin J, Alam R, Hart D, Knox R, Voshol P, Vidal-Puig A, Jensen J, O'Rahilly S, Semple RK. Truncation of Pik3r1 causes severe insulin resistance uncoupled from obesity and dyslipidaemia by increased energy expenditure. Mol Metab 2020; 40:101020. [PMID: 32439336 PMCID: PMC7385515 DOI: 10.1016/j.molmet.2020.101020] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 05/05/2020] [Accepted: 05/12/2020] [Indexed: 12/30/2022] Open
Abstract
OBJECTIVE Insulin signalling via phosphoinositide 3-kinase (PI3K) requires PIK3R1-encoded regulatory subunits. C-terminal PIK3R1 mutations cause SHORT syndrome, as well as lipodystrophy and insulin resistance (IR), surprisingly without fatty liver or metabolic dyslipidaemia. We sought to investigate this discordance. METHODS The human pathogenic Pik3r1 Y657∗ mutation was knocked into mice by homologous recombination. Growth, body composition, bioenergetic and metabolic profiles were investigated on chow and high-fat diet (HFD). We examined adipose and liver histology, and assessed liver responses to fasting and refeeding transcriptomically. RESULTS Like humans with SHORT syndrome, Pik3r1WT/Y657∗ mice were small with severe IR, and adipose expansion on HFD was markedly reduced. Also as in humans, plasma lipid concentrations were low, and insulin-stimulated hepatic lipogenesis was not increased despite hyperinsulinemia. At odds with lipodystrophy, however, no adipocyte hypertrophy nor adipose inflammation was found. Liver lipogenic gene expression was not significantly altered, and unbiased transcriptomics showed only minor changes, including evidence of reduced endoplasmic reticulum stress in the fed state and diminished Rictor-dependent transcription on fasting. Increased energy expenditure, which was not explained by hyperglycaemia nor intestinal malabsorption, provided an alternative explanation for the uncoupling of IR from dyslipidaemia. CONCLUSIONS Pik3r1 dysfunction in mice phenocopies the IR and reduced adiposity without lipotoxicity of human SHORT syndrome. Decreased adiposity may not reflect bona fide lipodystrophy, but rather, increased energy expenditure, and we suggest that further study of brown adipose tissue in both humans and mice is warranted.
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Affiliation(s)
- Albert Kwok
- The University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge, UK; MRC Metabolic Diseases Unit, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge, UK
| | - Ilona Zvetkova
- The University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge, UK; MRC Metabolic Diseases Unit, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge, UK
| | - Sam Virtue
- The University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge, UK; MRC Metabolic Diseases Unit, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge, UK
| | - Ineke Luijten
- Centre for Cardiovascular Science, University of Edinburgh, 47 Little France Crescent, Edinburgh, UK
| | - Isabel Huang-Doran
- The University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge, UK; MRC Metabolic Diseases Unit, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge, UK
| | - Patsy Tomlinson
- The University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge, UK; MRC Metabolic Diseases Unit, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge, UK
| | - David A Bulger
- The University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge, UK; MRC Metabolic Diseases Unit, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge, UK
| | - James West
- Department of Biochemistry and Cambridge Systems Biology Centre, University of Cambridge, Cambridge, UK
| | - Steven Murfitt
- Department of Biochemistry and Cambridge Systems Biology Centre, University of Cambridge, Cambridge, UK
| | - Julian Griffin
- Department of Biochemistry and Cambridge Systems Biology Centre, University of Cambridge, Cambridge, UK; Biomolecular Medicine, Division of Systems Medicine, Department of Metabolism, Digestion and Reproduction, Medicine, Imperial College London, The Sir Alexander Fleming Building, London, UK
| | - Rafeah Alam
- Laboratory of Lymphocyte Signalling and Development, The Babraham Institute, Cambridge, UK
| | - Daniel Hart
- The University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge, UK; MRC Metabolic Diseases Unit, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge, UK
| | - Rachel Knox
- The University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge, UK; MRC Metabolic Diseases Unit, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge, UK
| | - Peter Voshol
- Louis Bolk Institute, Kosterijland 3-5, NL-3981 AJ, Bunnik, the Netherlands
| | - Antonio Vidal-Puig
- The University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge, UK; MRC Metabolic Diseases Unit, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge, UK
| | - Jørgen Jensen
- Department of Physical Performance, Norwegian School of Sport Sciences, P.O. Box 4014, Ulleval Stadion, 0806 Oslo, Norway
| | - Stephen O'Rahilly
- The University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge, UK; MRC Metabolic Diseases Unit, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge, UK
| | - Robert K Semple
- Centre for Cardiovascular Science, University of Edinburgh, 47 Little France Crescent, Edinburgh, UK; The University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge, UK; MRC Metabolic Diseases Unit, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge, UK.
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Oleic Acid Protects Against Insulin Resistance by Regulating the Genes Related to the PI3K Signaling Pathway. J Clin Med 2020; 9:jcm9082615. [PMID: 32806641 PMCID: PMC7463472 DOI: 10.3390/jcm9082615] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 07/28/2020] [Accepted: 08/10/2020] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND The effects of different types of fatty acids on the gene expression of key players in the IRS1/PI3K signaling pathway have been poorly studied. MATERIAL AND METHODS We analyzed IRS1, p85α, and p110β mRNA expression and the fatty acid composition of phospholipids in visceral adipose tissue from patients with morbid obesity and from non-obese patients. Moreover, we analyzed the expression of those genes in visceral adipocytes incubated with oleic, linoleic, palmitic and dosahexaenoic acids. RESULTS We found a reduced IRS1 expression in patients with morbid obesity, independent of insulin resistance, and a reduced p110β expression in those with lower insulin resistance. A positive correlation was found between p85α and stearic acid, and between IRS1 and p110β with palmitic and dosahexaenoic acid. In contrast, a negative correlation was found between p85α and oleic acid, and between IRS1 and p110β with linoleic, arachidonic and adrenic acid. Incubation with palmitic acid decreased IRS1 expression. p85α was down-regulated after incubation with oleic and dosahexaenoic acid and up-regulated with palmitic acid. p110β expression was increased and decreased after incubation with oleic and palmitic acid, respectively. The ratio p85α/p110β was decreased by oleic and dosahexaenoic acid and increased by palmitic acid. CONCLUSIONS Our in vitro results suggest a detrimental role of palmitic acid on the expression of gene related to insulin signaling pathway, with oleic acid being the one with the higher and more beneficial effects. DHA had a slight beneficial effect. Fatty acid-induced regulation of genes related to the IRS1/PI3K pathway may be a novel mechanism by which fatty acids regulate insulin sensitivity in visceral adipocytes.
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