201
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Law NC, Hunzicker-Dunn ME. Insulin Receptor Substrate 1, the Hub Linking Follicle-stimulating Hormone to Phosphatidylinositol 3-Kinase Activation. J Biol Chem 2015; 291:4547-60. [PMID: 26702053 DOI: 10.1074/jbc.m115.698761] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Indexed: 12/21/2022] Open
Abstract
The ubiquitous phosphatidylinositol 3-kinase (PI3K) signaling pathway regulates many cellular functions. However, the mechanism by which G protein-coupled receptors (GPCRs) signal to activate PI3K is poorly understood. We have used ovarian granulosa cells as a model to investigate this pathway, based on evidence that the GPCR agonist follicle-stimulating hormone (FSH) promotes the protein kinase A (PKA)-dependent phosphorylation of insulin receptor substrate 1 (IRS1) on tyrosine residues that activate PI3K. We report that in the absence of FSH, granulosa cells secrete a subthreshold concentration of insulin-like growth factor-1 (IGF-1) that primes the IGF-1 receptor (IGF-1R) but fails to promote tyrosine phosphorylation of IRS1. FSH via PKA acts to sensitize IRS1 to the tyrosine kinase activity of the IGF-1R by activating protein phosphatase 1 (PP1) to promote dephosphorylation of inhibitory Ser/Thr residues on IRS1, including Ser(789). Knockdown of PP1β blocks the ability of FSH to activate PI3K in the presence of endogenous IGF-1. Activation of PI3K thus requires both PKA-mediated relief of IRS1 inhibition and IGF-1R-dependent tyrosine phosphorylation of IRS1. Treatment with FSH and increasing concentrations of exogenous IGF-1 triggers synergistic IRS1 tyrosine phosphorylation at PI3K-activating residues that persists downstream through protein kinase B (AKT) and FOXO1 (forkhead box protein O1) to drive synergistic expression of genes that underlies follicle maturation. Based on the ability of GPCR agonists to synergize with IGFs to enhance gene expression in other cell types, PP1 activation to relieve IRS1 inhibition may be a more general mechanism by which GPCRs act with the IGF-1R to activate PI3K/AKT.
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Affiliation(s)
- Nathan C Law
- From the School of Molecular Biosciences, Washington State University, Pullman, Washington 99164
| | - Mary E Hunzicker-Dunn
- From the School of Molecular Biosciences, Washington State University, Pullman, Washington 99164
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202
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Bedinger DH, Adams SH. Metabolic, anabolic, and mitogenic insulin responses: A tissue-specific perspective for insulin receptor activators. Mol Cell Endocrinol 2015; 415:143-56. [PMID: 26277398 DOI: 10.1016/j.mce.2015.08.013] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 08/05/2015] [Accepted: 08/09/2015] [Indexed: 12/17/2022]
Abstract
Insulin acts as the major regulator of the fasting-to-fed metabolic transition by altering substrate metabolism, promoting energy storage, and helping activate protein synthesis. In addition to its glucoregulatory and other metabolic properties, insulin can also act as a growth factor. The metabolic and mitogenic responses to insulin are regulated by divergent post-receptor signaling mechanisms downstream from the activated insulin receptor (IR). However, the anabolic and growth-promoting properties of insulin require tissue-specific inter-relationships between the two pathways, and the nature and scope of insulin-regulated processes vary greatly across tissues. Understanding the nuances of this interplay between metabolic and growth-regulating properties of insulin would have important implications for development of novel insulin and IR modulator therapies that stimulate insulin receptor activation in both pathway- and tissue-specific manners. This review will provide a unique perspective focusing on the roles of "metabolic" and "mitogenic" actions of insulin signaling in various tissues, and how these networks should be considered when evaluating selective pharmacologic approaches to prevent or treat metabolic disease.
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Affiliation(s)
| | - Sean H Adams
- Arkansas Children's Nutrition Center and University of Arkansas for Medical Sciences, Department of Pediatrics, Little Rock, AR, USA
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203
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Abstract
Until recently, type 2 diabetes was seen as a disease caused by an impaired ability of insulin to promote the uptake and utilisation of glucose. Work on forkhead box protein O (FOXO) transcription factors revealed new aspects of insulin action that have led us to articulate a liver- and beta cell-centric narrative of diabetes pathophysiology and treatment. FOXO integrate a surprisingly diverse subset of biological functions to promote metabolic flexibility. In the liver, they controls the glucokinase/glucose-6-phosphatase switch and bile acid pool composition, directing carbons to glucose or lipid utilisation, thus providing a unifying mechanism for the two abnormalities of the diabetic liver: excessive glucose production and increased lipid synthesis and secretion. Moreover, FOXO are necessary to maintain beta cell differentiation, and diabetes development is associated with a gradual loss of FOXO function that brings about beta cell dedifferentiation. We proposed that dedifferentiation is the main cause of beta cell failure and conversion into non-beta endocrine cells, and that treatment should restore beta cell differentiation. Our studies investigating these proposals have revealed new dimensions to the pathophysiology of diabetes that can be leveraged to design new therapies.
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Affiliation(s)
- Utpal B Pajvani
- Department of Medicine and Naomi Berrie Diabetes Center, Columbia University Medical Center, 1150 St Nicholas Av., New York, NY, 10032, USA.
| | - Domenico Accili
- Department of Medicine and Naomi Berrie Diabetes Center, Columbia University Medical Center, 1150 St Nicholas Av., New York, NY, 10032, USA.
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204
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Chettouh H, Lequoy M, Fartoux L, Vigouroux C, Desbois-Mouthon C. Hyperinsulinaemia and insulin signalling in the pathogenesis and the clinical course of hepatocellular carcinoma. Liver Int 2015; 35:2203-17. [PMID: 26123841 DOI: 10.1111/liv.12903] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Accepted: 06/09/2015] [Indexed: 12/11/2022]
Abstract
Hepatocellular carcinoma (HCC) is the fifth most prevalent cancer and is one of the leading causes of cancer-related death. The risk factors for HCC include cirrhosis, chronic viral hepatitis, heavy alcohol intake and metabolic diseases such as obesity, type 2 diabetes and metabolic syndrome. Insulin resistance is a common denominator of all of these conditions and is tethered to hyperinsulinaemia. Here, we give an overview of the recent advances linking hyperinsulinaemia to HCC development and progression. In particular, we summarise the underlying causes of hyperinsulinaemia in the setting of chronic liver diseases. We present epidemiological evidence linking metabolic diseases to HCC risk and HCC-related mortality, as well as the pathogenic cellular and molecular mechanisms explaining this relation. A better understanding of the mechanisms by which insulin participates in HCC biology might ultimately provide novel opportunities for prevention and treatment.
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Affiliation(s)
- Hamza Chettouh
- Sorbonne Universités, UPMC Univ Paris 06, UMR_S 938, Centre de Recherche Saint-Antoine, Paris, France.,INSERM, UMR_S 938, Centre de Recherche Saint-Antoine, Paris, France
| | - Marie Lequoy
- Sorbonne Universités, UPMC Univ Paris 06, UMR_S 938, Centre de Recherche Saint-Antoine, Paris, France.,INSERM, UMR_S 938, Centre de Recherche Saint-Antoine, Paris, France.,Service d'Hépatologie, AP-HP, Hôpital Saint-Antoine, Paris, France
| | - Laetitia Fartoux
- Sorbonne Universités, UPMC Univ Paris 06, UMR_S 938, Centre de Recherche Saint-Antoine, Paris, France.,INSERM, UMR_S 938, Centre de Recherche Saint-Antoine, Paris, France.,Service d'Hépatologie, AP-HP, Hôpital Saint-Antoine, Paris, France
| | - Corinne Vigouroux
- Sorbonne Universités, UPMC Univ Paris 06, UMR_S 938, Centre de Recherche Saint-Antoine, Paris, France.,INSERM, UMR_S 938, Centre de Recherche Saint-Antoine, Paris, France.,Laboratoire Commun de Biologie et Génétique Moléculaires AP-HP, Hôpital Saint-Antoine, Paris, France.,ICAN, Institute of Cardiometabolism and Nutrition, Paris, France
| | - Christèle Desbois-Mouthon
- Sorbonne Universités, UPMC Univ Paris 06, UMR_S 938, Centre de Recherche Saint-Antoine, Paris, France.,INSERM, UMR_S 938, Centre de Recherche Saint-Antoine, Paris, France
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205
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Nemazanyy I, Montagnac G, Russell RC, Morzyglod L, Burnol AF, Guan KL, Pende M, Panasyuk G. Class III PI3K regulates organismal glucose homeostasis by providing negative feedback on hepatic insulin signalling. Nat Commun 2015; 6:8283. [PMID: 26387534 PMCID: PMC4579570 DOI: 10.1038/ncomms9283] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Accepted: 08/07/2015] [Indexed: 11/09/2022] Open
Abstract
Defective hepatic insulin receptor (IR) signalling is a pathogenic manifestation of metabolic disorders including obesity and diabetes. The endo/lysosomal trafficking system may coordinate insulin action and nutrient homeostasis by endocytosis of IR and the autophagic control of intracellular nutrient levels. Here we show that class III PI3K--a master regulator of endocytosis, endosomal sorting and autophagy--provides negative feedback on hepatic insulin signalling. The ultraviolet radiation resistance-associated gene protein (UVRAG)-associated class III PI3K complex interacts with IR and is stimulated by insulin treatment. Acute and chronic depletion of hepatic Vps15, the regulatory subunit of class III PI3K, increases insulin sensitivity and Akt signalling, an effect that requires functional IR. This is reflected by FoxO1-dependent transcriptional defects and blunted gluconeogenesis in Vps15 mutant cells. On depletion of Vps15, the metabolic syndrome in genetic and diet-induced models of insulin resistance and diabetes is alleviated. Thus, feedback regulation of IR trafficking and function by class III PI3K may be a therapeutic target in metabolic conditions of insulin resistance.
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Affiliation(s)
- Ivan Nemazanyy
- Institut Necker-Enfants Malades (INEM), Cedex 14, 75993 Paris, France.,Institut National de la Santé et de la Recherche Médicale (INSERM), Cedex 14, U1151, 75993 Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, 75006 Paris, France
| | - Guillaume Montagnac
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1170, Gustave Roussy Institute, 94805 Villejuif, France
| | - Ryan C Russell
- Department of Pharmacology, University of California at San Diego, La Jolla, California 92093, USA.,Moores Cancer Center, University of California at San Diego, La Jolla, California 92093, USA
| | - Lucille Morzyglod
- Université Paris Descartes, Sorbonne Paris Cité, 75006 Paris, France.,Institut National de la Santé et de la Recherche Médicale (INSERM), U1016, Institut Cochin, 75014 Paris, France.,Centre national de la recherche scientifique (CNRS), UMR8104, 75014 Paris, France
| | - Anne-Françoise Burnol
- Université Paris Descartes, Sorbonne Paris Cité, 75006 Paris, France.,Institut National de la Santé et de la Recherche Médicale (INSERM), U1016, Institut Cochin, 75014 Paris, France.,Centre national de la recherche scientifique (CNRS), UMR8104, 75014 Paris, France
| | - Kun-Liang Guan
- Department of Pharmacology, University of California at San Diego, La Jolla, California 92093, USA.,Moores Cancer Center, University of California at San Diego, La Jolla, California 92093, USA
| | - Mario Pende
- Institut Necker-Enfants Malades (INEM), Cedex 14, 75993 Paris, France.,Institut National de la Santé et de la Recherche Médicale (INSERM), Cedex 14, U1151, 75993 Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, 75006 Paris, France
| | - Ganna Panasyuk
- Institut Necker-Enfants Malades (INEM), Cedex 14, 75993 Paris, France.,Institut National de la Santé et de la Recherche Médicale (INSERM), Cedex 14, U1151, 75993 Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, 75006 Paris, France
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206
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Zou P, Liu L, Zheng L, Liu L, Stoneman RE, Cho A, Emery A, Gilbert ER, Cheng Z. Targeting FoxO1 with AS1842856 suppresses adipogenesis. Cell Cycle 2015; 13:3759-67. [PMID: 25483084 PMCID: PMC4613185 DOI: 10.4161/15384101.2014.965977] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Hyperplasia (i.e., increased adipogenesis) contributes to excess adiposity, the hallmark of obesity that can trigger metabolic complications. As FoxO1 has been implicated in adipogenic regulation, we investigated the kinetics of FoxO1 activation during adipocyte differentiation, and tested the effects of FoxO1 antagonist (AS1842856) on adipogenesis. We found for the first time that the kinetics of FoxO1 activation follows a series of sigmoid curves, and reveals the phases relevant to clonal expansion, cell cycle arrest, and the regulation of PPARγ, adiponectin, and mitochondrial proteins (complexes I and III). In addition, multiple activation-inactivation transitions exist in the stage of terminal differentiation. Importantly, persistent inhibition of FoxO1 with AS1842856 almost completely suppressed adipocyte differentiation, while selective inhibition in specific stages had differential effects on adipogenesis. Our data present a new view of FoxO1 in adipogenic regulation, and suggest AS1842856 can be an anti-obesity agent that warrants further investigation.
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Key Words
- AS1842856
- AS1842856, 5-amino-7-(cyclohexylamino)-1-ethyl-6-fluoro-4-oxo-1, 4-dihydroquinoline-3-carboxylic acid
- BMI, basal media I
- BMII, basal media II
- C1, mitochondrial complex I
- C3, mitochondrial complex III
- DMI, differentiation media I
- DMII, differentiation media II
- FoxO1
- FoxO1, forkhead box O1
- G6P, glucose 6-phosphatase
- PEPCK, phosphoenolpyruvate carboxykinase
- PPARγ, peroxisome proliferator-activated receptor gamma
- T2DM, type 2 diabetes mellitus
- adipogenesis
- mitochondria
- obesity
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Affiliation(s)
- Peng Zou
- a Department of Human Nutrition, Foods and Exercise; Fralin Life Science Institute; College of Agriculture and Life Science; Virginia Tech , Blacksburg , VA USA
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207
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Cordoba-Chacon J, Majumdar N, List EO, Diaz-Ruiz A, Frank SJ, Manzano A, Bartrons R, Puchowicz M, Kopchick JJ, Kineman RD. Growth Hormone Inhibits Hepatic De Novo Lipogenesis in Adult Mice. Diabetes 2015; 64:3093-103. [PMID: 26015548 PMCID: PMC4542445 DOI: 10.2337/db15-0370] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Accepted: 05/20/2015] [Indexed: 02/07/2023]
Abstract
Patients with nonalcoholic fatty liver disease (NAFLD) are reported to have low growth hormone (GH) production and/or hepatic GH resistance. GH replacement can resolve the fatty liver condition in diet-induced obese rodents and in GH-deficient patients. However, it remains to be determined whether this inhibitory action of GH is due to direct regulation of hepatic lipid metabolism. Therefore, an adult-onset, hepatocyte-specific, GH receptor (GHR) knockdown (aLivGHRkd) mouse was developed to model hepatic GH resistance in humans that may occur after sexual maturation. Just 7 days after aLivGHRkd, hepatic de novo lipogenesis (DNL) was increased in male and female chow-fed mice, compared with GHR-intact littermate controls. However, hepatosteatosis developed only in male and ovariectomized female aLivGHRkd mice. The increase in DNL observed in aLivGHRkd mice was not associated with hyperactivation of the pathway by which insulin is classically considered to regulate DNL. However, glucokinase mRNA and protein levels as well as fructose-2,6-bisphosphate levels were increased in aLivGHRkd mice, suggesting that enhanced glycolysis drives DNL in the GH-resistant liver. These results demonstrate that hepatic GH actions normally serve to inhibit DNL, where loss of this inhibitory signal may explain, in part, the inappropriate increase in hepatic DNL observed in NAFLD patients.
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Affiliation(s)
- Jose Cordoba-Chacon
- Research and Development Division, Jesse Brown VA Medical Center, Chicago, IL Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, College of Medicine, University of Illinois at Chicago, Chicago, IL
| | - Neena Majumdar
- Research and Development Division, Jesse Brown VA Medical Center, Chicago, IL Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, College of Medicine, University of Illinois at Chicago, Chicago, IL
| | - Edward O List
- Edison Biotechnology Institute, Ohio University, Athens, OH Department of Specialty Medicine, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH
| | - Alberto Diaz-Ruiz
- Experimental Gerontology Section, Translational Gerontology Branch, National Institute on Aging, National Institutes of Health, Baltimore, MD
| | - Stuart J Frank
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, School of Medicine, University of Alabama at Birmingham, Birmingham, AL Endocrinology Section Medical Service, Birmingham VA Medical Center, Birmingham, AL
| | - Anna Manzano
- Department of Physiological Sciences, University of Barcelona, L'Hospitalet, Barcelona, Spain
| | - Ramon Bartrons
- Department of Physiological Sciences, University of Barcelona, L'Hospitalet, Barcelona, Spain
| | - Michelle Puchowicz
- Department of Nutrition, Case Western Reserve University School of Medicine, Cleveland, OH
| | - John J Kopchick
- Edison Biotechnology Institute, Ohio University, Athens, OH Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH
| | - Rhonda D Kineman
- Research and Development Division, Jesse Brown VA Medical Center, Chicago, IL Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, College of Medicine, University of Illinois at Chicago, Chicago, IL
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208
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Shiwa M, Yoneda M, Okubo H, Ohno H, Kobuke K, Monzen Y, Kishimoto R, Nakatsu Y, Asano T, Kohno N. Distinct Time Course of the Decrease in Hepatic AMP-Activated Protein Kinase and Akt Phosphorylation in Mice Fed a High Fat Diet. PLoS One 2015; 10:e0135554. [PMID: 26266809 PMCID: PMC4534138 DOI: 10.1371/journal.pone.0135554] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Accepted: 07/23/2015] [Indexed: 12/25/2022] Open
Abstract
AMP-activated protein kinase (AMPK) plays an important role in insulin resistance, which is characterized by the impairment of the insulin-Akt signaling pathway. However, the time course of the decrease in AMPK and Akt phosphorylation in the liver during the development of obesity and insulin resistance caused by feeding a high fat diet (HFD) remains controversial. Moreover, it is unclear whether the impairment of AMPK and Akt signaling pathways is reversible when changing from a HFD to a standard diet (SD). Male ddY mice were fed the SD or HFD for 3 to 28 days, or fed the HFD for 14 days, followed by the SD for 14 days. We examined the time course of the expression and phosphorylation levels of AMPK and Akt in the liver by immunoblotting. After 3 days of feeding on the HFD, mice gained body weight, resulting in an increased oil red O staining, indicative of hepatic lipid accumulation, and significantly decreased AMPK phosphorylation, in comparison with mice fed the SD. After 14 days on the HFD, systemic insulin resistance occurred and Akt phosphorylation significantly decreased. Subsequently, a change from the HFD to SD for 3 days, after 14 days on the HFD, ameliorated the impairment of AMPK and Akt phosphorylation and systemic insulin resistance. Our findings indicate that AMPK phosphorylation decreases early upon feeding a HFD and emphasizes the importance of prompt lifestyle modification for decreasing the risk of developing diabetes.
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Affiliation(s)
- Mami Shiwa
- Department of Molecular and Internal Medicine, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Masayasu Yoneda
- Department of Molecular and Internal Medicine, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Hirofumi Okubo
- Department of Molecular and Internal Medicine, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Haruya Ohno
- Department of Molecular and Internal Medicine, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Kazuhiro Kobuke
- Department of Molecular and Internal Medicine, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Yuko Monzen
- Department of Molecular and Internal Medicine, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Rui Kishimoto
- Department of Molecular and Internal Medicine, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Yusuke Nakatsu
- Department of Biomedical Chemistry, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Tomoichiro Asano
- Department of Biomedical Chemistry, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Nobuoki Kohno
- Department of Molecular and Internal Medicine, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
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209
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Abstract
The transcription factor forkhead box O1 (FoxO1) plays pleiotropic roles in insulin-mediated glucose and lipid metabolism. In the liver, glucose production is finely controlled by insulin signaling that dampens FoxO1. Two recent studies show that silencing of FoxO1 is also essential for extra-hepatic insulin signaling to maintain glucose homeostasis.
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Affiliation(s)
- Zhiyong Cheng
- Department of Human Nutrition, Foods and Exercise, Fralin Translational Obesity Research Center, College of Agriculture and Life Science, Virginia Tech, Blacksburg, VA, USA.
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210
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Abstract
FoxO transcription factors promote longevity across taxa. How they do so is poorly understood. In the nematode Caenorhabditis elegans, the A- and F-isoforms of the FoxO transcription factor DAF-16 extend life span in the context of reduced DAF-2 insulin-like growth factor receptor (IGFR) signaling. To elucidate the mechanistic basis for DAF-16/FoxO-dependent life span extension, we performed an integrative analysis of isoform-specific daf-16/FoxO mutants. In contrast to previous studies suggesting that DAF-16F plays a more prominent role in life span control than DAF-16A, isoform-specific daf-16/FoxO mutant phenotypes and whole transcriptome profiling revealed a predominant role for DAF-16A over DAF-16F in life span control, stress resistance, and target gene regulation. Integration of these datasets enabled the prioritization of a subset of 92 DAF-16/FoxO target genes for functional interrogation. Among 29 genes tested, two DAF-16A-specific target genes significantly influenced longevity. A loss-of-function mutation in the conserved gene gst-20, which is induced by DAF-16A, reduced life span extension in the context of daf-2/IGFR RNAi without influencing longevity in animals subjected to control RNAi. Therefore, gst-20 promotes DAF-16/FoxO-dependent longevity. Conversely, a loss-of-function mutation in srr-4, a gene encoding a seven-transmembrane-domain receptor family member that is repressed by DAF-16A, extended life span in control animals, indicating that DAF-16/FoxO may extend life span at least in part by reducing srr-4 expression. Our discovery of new longevity genes underscores the efficacy of our integrative strategy while providing a general framework for identifying specific downstream gene regulatory events that contribute substantially to transcription factor functions. As FoxO transcription factors have conserved functions in promoting longevity and may be dysregulated in aging-related diseases, these findings promise to illuminate fundamental principles underlying aging in animals.
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211
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Abstract
Acne vulgaris, an epidemic inflammatory skin disease of adolescence, is closely related to Western diet. Three major food classes that promote acne are: 1) hyperglycemic carbohydrates, 2) milk and dairy products, 3) saturated fats including trans-fats and deficient ω-3 polyunsaturated fatty acids (PUFAs). Diet-induced insulin/insulin-like growth factor (IGF-1)-signaling is superimposed on elevated IGF-1 levels during puberty, thereby unmasking the impact of aberrant nutrigenomics on sebaceous gland homeostasis. Western diet provides abundant branched-chain amino acids (BCAAs), glutamine, and palmitic acid. Insulin and IGF-1 suppress the activity of the metabolic transcription factor forkhead box O1 (FoxO1). Insulin, IGF-1, BCAAs, glutamine, and palmitate activate the nutrient-sensitive kinase mechanistic target of rapamycin complex 1 (mTORC1), the key regulator of anabolism and lipogenesis. FoxO1 is a negative coregulator of androgen receptor, peroxisome proliferator-activated receptor-γ (PPARγ), liver X receptor-α, and sterol response element binding protein-1c (SREBP-1c), crucial transcription factors of sebaceous lipogenesis. mTORC1 stimulates the expression of PPARγ and SREBP-1c, promoting sebum production. SREBP-1c upregulates stearoyl-CoA- and Δ6-desaturase, enhancing the proportion of monounsaturated fatty acids in sebum triglycerides. Diet-mediated aberrations in sebum quantity (hyperseborrhea) and composition (dysseborrhea) promote Propionibacterium acnes overgrowth and biofilm formation with overexpression of the virulence factor triglyceride lipase increasing follicular levels of free palmitate and oleate. Free palmitate functions as a "danger signal," stimulating toll-like receptor-2-mediated inflammasome activation with interleukin-1β release, Th17 differentiation, and interleukin-17-mediated keratinocyte proliferation. Oleate stimulates P. acnes adhesion, keratinocyte proliferation, and comedogenesis via interleukin-1α release. Thus, diet-induced metabolomic alterations promote the visible sebofollicular inflammasomopathy acne vulgaris. Nutrition therapy of acne has to increase FoxO1 and to attenuate mTORC1/SREBP-1c signaling. Patients should balance total calorie uptake and restrict refined carbohydrates, milk, dairy protein supplements, saturated fats, and trans-fats. A paleolithic-like diet enriched in vegetables and fish is recommended. Plant-derived mTORC1 inhibitors and ω-3-PUFAs are promising dietary supplements supporting nutrition therapy of acne vulgaris.
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Affiliation(s)
- Bodo C Melnik
- Department of Dermatology, Environmental Medicine and Health Theory, University of Osnabrück, Germany
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212
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Song J, Kang SM, Kim E, Kim CH, Song HT, Lee JE. Impairment of insulin receptor substrate 1 signaling by insulin resistance inhibits neurite outgrowth and aggravates neuronal cell death. Neuroscience 2015; 301:26-38. [PMID: 26047734 DOI: 10.1016/j.neuroscience.2015.05.072] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Revised: 05/22/2015] [Accepted: 05/28/2015] [Indexed: 02/02/2023]
Abstract
In the central nervous system (CNS), insulin resistance (I/R) can cause defective neurite outgrowth and neuronal cell death, which can eventually lead to cognitive deficits. Recent research has focused on the relationship between I/R and the cognitive impairment caused by dementia, with the goal of developing treatments for dementia. Insulin signal transduction mediated by insulin receptor substrate (IRS-1) has been thoroughly studied in the CNS of patients with I/R. In the present study, we investigated whether the impairment of IRS-1-mediated insulin signaling contributes to neurite outgrowth and neuronal loss, both in mice fed a high-fat diet and in mouse neuroblastoma (Neuro2A) cells. To investigate the changes caused by the inhibition of IRS-1-mediated insulin signaling in the brain, we performed Cresyl Violet staining and immunochemical analysis. To investigate the changes caused by the inhibition of IRS-1-mediated insulin signaling in neuroblastoma cells, we performed Western blot analysis, reverse transcription-PCR, and immunochemical analysis. We show that the deactivation of IRS-1-mediated insulin signaling can inhibit neuronal outgrowth and aggravate neuronal cell death in the insulin-resistant CNS. Thus, IRS-1-mediated insulin signal transduction may be an important factor in the treatment of cognitive decline induced by I/R.
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Affiliation(s)
- J Song
- Department of Anatomy, Yonsei University College of Medicine, Seoul 120-752, South Korea.
| | - S M Kang
- Department of Anatomy, Yonsei University College of Medicine, Seoul 120-752, South Korea; BK21 Plus Project for Medical Sciences and Brain Research Institute, Yonsei University College of Medicine, Seoul 120-752, South Korea.
| | - E Kim
- Department of Psychiatry, Yonsei University College of Medicine, Seoul 120-752, South Korea.
| | - C-H Kim
- Department of Pharmacology, Yonsei University College of Medicine, Seoul 120-752, South Korea.
| | - H-T Song
- Department of Diagnostic Radiology, Yonsei University College of Medicine, Seoul 120-752, South Korea.
| | - J E Lee
- Department of Anatomy, Yonsei University College of Medicine, Seoul 120-752, South Korea; BK21 Plus Project for Medical Sciences and Brain Research Institute, Yonsei University College of Medicine, Seoul 120-752, South Korea.
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213
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Cook JR, Matsumoto M, Banks AS, Kitamura T, Tsuchiya K, Accili D. A mutant allele encoding DNA binding-deficient FoxO1 differentially regulates hepatic glucose and lipid metabolism. Diabetes 2015; 64:1951-65. [PMID: 25576059 PMCID: PMC4439558 DOI: 10.2337/db14-1506] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Accepted: 01/07/2015] [Indexed: 12/27/2022]
Abstract
Insulin signaling in the liver blunts glucose production and stimulates triglyceride biosynthesis. FoxO1 is required for cAMP induction of hepatic glucose production and is permissive for the effect of insulin to suppress this process. Moreover, FoxO1 ablation increases lipogenesis. In this study, we investigated the pleiotropic actions of FoxO1 on glucose and lipid metabolism. To this end, we reconstituted FoxO1 function in mice with a liver-specific deletion of Foxo1 using targeted knock-in of an allele encoding a DNA binding-deficient FoxO1 mutant (L-DBD). Chow-reared L-DBD mice showed defects in hepatic glucose production but normal liver triglyceride content despite increased rates of de novo lipogenesis and impaired fatty acid oxidation in isolated hepatocytes. Gene expression studies indicated that FoxO1 regulates the expression of glucokinase via a cell-nonautonomous coregulatory mechanism, while its regulation of glucose-6-phosphatase proceeds via a cell-autonomous action as a direct transcriptional activator. These conclusions support a differential regulation of hepatic glucose and lipid metabolism by FoxO1 based on the mechanism by which it alters the expression of key target genes involved in each process.
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Affiliation(s)
- Joshua R Cook
- Department of Medicine, Columbia University, New York, NY
| | - Michihiro Matsumoto
- Department of Medicine, Columbia University, New York, NY Department of Molecular Metabolic Regulation, Diabetes Research Center, National Center for Global Health and Medicine, Tokyo, Japan
| | - Alexander S Banks
- Department of Medicine, Columbia University, New York, NY Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA
| | - Tadahiro Kitamura
- Department of Medicine, Columbia University, New York, NY Department of Medicine and Biological Science, Gunma University Graduate School of Medicine, Gunma, Japan
| | - Kyoichiro Tsuchiya
- Department of Medicine, Columbia University, New York, NY Department of Clinical and Molecular Endocrinology, Tokyo Medical and Dental University Graduate School, Tokyo, Japan
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214
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Endoplasmic reticulum stress impairs insulin receptor signaling in the brains of obese rats. PLoS One 2015; 10:e0126384. [PMID: 25978724 PMCID: PMC4433117 DOI: 10.1371/journal.pone.0126384] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 04/01/2015] [Indexed: 12/11/2022] Open
Abstract
The incidence of obesity is increasing worldwide. It was reported that endoplasmic reticulum stress (ERS) could inhibit insulin receptor signaling by activating c-Jun N-terminal kinase (JNK) in the liver. However, the relationship between ERS and insulin receptor signaling in the brain during obesity remains unclear. The aim of the current study was to assess whether ERS alters insulin receptor signaling through the hyper-activation of JNK in the hippocampus and frontal cortex in the brains of obese rats. Obesity was induced using a high fat diet (HFD). The Morris water maze test was then performed to evaluate decreases in cognitive function, and western blot was used to verify whether abnormal insulin receptor signaling was induced by ERS in HFD rats exhibiting cognitive decline. In addition, to determine whether ERS activated JNK and consequently impaired insulin receptor signaling, SH-SY5Y cells were treated with the JNK inhibitor, SP600125, followed by tunicamycin or thapsigargin, and primary rat hippocampal and cortical neurons were transfected with siRNA against IRE1α and JNK. We found that the expression of phosphorylation of PKR-like kinase (PERK), phosphorylation of α subunit of translation initiation factor 2 (eIF2α), and phosphorylation of inositol-requiring kinase-1α (IRE-1α) were increased in the brains of rats with HFD when compared with control rats. The level of serine phosphorylation of insulin receptor substrate-1 (IRS-1) was also increased, while protein kinase B (PKB/Akt) was reduced. ERS was also found to inhibit insulin receptor signaling via the activation of JNK in SH-SY5Y cells, primary rat hippocampal, and cortical neurons. These results indicate that ERS was increased, thereby resulting in impaired insulin receptor signaling in the hippocampus and frontal cortex of obese rats.
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215
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Titchenell PM, Chu Q, Monks BR, Birnbaum MJ. Hepatic insulin signalling is dispensable for suppression of glucose output by insulin in vivo. Nat Commun 2015; 6:7078. [PMID: 25963408 PMCID: PMC4429930 DOI: 10.1038/ncomms8078] [Citation(s) in RCA: 111] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 04/01/2015] [Indexed: 12/31/2022] Open
Abstract
Insulin signaling and nutrient levels coordinate the metabolic response to feeding in the liver. Insulin signals in hepatocytes to activate Akt, which inhibits Foxo1 suppressing hepatic glucose production (HGP) and allowing the transition to the postprandial state. Here we provide genetic evidence that insulin regulates HGP by both direct and indirect hepatic mechanisms. Liver-specific ablation of the IR (L-Insulin Receptor KO) induces glucose intolerance, insulin resistance and prevents the appropriate transcriptional response to feeding. Liver-specific deletion of Foxo1 (L-IRFoxo1DKO) rescues glucose tolerance and allows for normal suppression of HGP and gluconeogenic gene expression in response to insulin despite lack of autonomous liver insulin signaling. These data indicate that, in the absence of Foxo1, insulin signals via an intermediary extra-hepatic tissue to regulate liver glucose production. Importantly, a hepatic mechanism distinct from the IR-Akt-Foxo1 axis exists to regulate glucose production.
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Affiliation(s)
- Paul M Titchenell
- Department of Medicine, Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Qingwei Chu
- Department of Medicine, Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Bobby R Monks
- Department of Medicine, Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Morris J Birnbaum
- Department of Medicine, Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
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216
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O-Sullivan I, Zhang W, Wasserman DH, Liew CW, Liu J, Paik J, DePinho RA, Stolz DB, Kahn CR, Schwartz MW, Unterman TG. FoxO1 integrates direct and indirect effects of insulin on hepatic glucose production and glucose utilization. Nat Commun 2015; 6:7079. [PMID: 25963540 PMCID: PMC4755301 DOI: 10.1038/ncomms8079] [Citation(s) in RCA: 149] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 04/01/2015] [Indexed: 12/18/2022] Open
Abstract
FoxO proteins are major targets of insulin action. To better define the role of FoxO1 in mediating insulin effects in the liver, we generated liver-specific insulin receptor knockout (LIRKO) and IR/FoxO1 double knockout (LIRFKO) mice. Here we show that LIRKO mice are severely insulin resistant based on glucose, insulin and C-peptide levels, and glucose and insulin tolerance tests, and genetic deletion of hepatic FoxO1 reverses these effects. (13)C-glucose and insulin clamp studies indicate that regulation of both hepatic glucose production (HGP) and glucose utilization is impaired in LIRKO mice, and these defects are also restored in LIRFKO mice corresponding to changes in gene expression. We conclude that (1) inhibition of FoxO1 is critical for both direct (hepatic) and indirect effects of insulin on HGP and utilization, and (2) extrahepatic effects of insulin are sufficient to maintain normal whole-body and hepatic glucose metabolism when liver FoxO1 activity is disrupted.
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Affiliation(s)
- InSug O-Sullivan
- Section of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Illinois at Chicago College of Medicine, Chicago, Illinois 60612, USA
| | - Wenwei Zhang
- Section of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Illinois at Chicago College of Medicine, Chicago, Illinois 60612, USA
| | - David H Wasserman
- Department of Molecular Physiology and Biophysics, Vanderbilt Medical School, Nashville, Tennesse 37232, USA
| | - Chong Wee Liew
- Department of Physiology and Biophysics, University of Illinois at Chicago College of Medicine, Chicago, Illinois 60612, USA
| | - Jonathan Liu
- Section of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Illinois at Chicago College of Medicine, Chicago, Illinois 60612, USA
| | - Jihye Paik
- Dana Farber Cancer Institute, Boston, Massachusetts 02215, USA
| | | | - Donna Beer Stolz
- Department of Cell Biology, Center for Biologic Imaging, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA
| | - C Ronald Kahn
- Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts 02215, USA
| | - Michael W Schwartz
- Diabetes and Obesity Center of Excellence, University of Washington, Seattle, Washington 98104, USA
| | - Terry G Unterman
- 1] Section of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Illinois at Chicago College of Medicine, Chicago, Illinois 60612, USA [2] Medical Service, Jesse Brown VA Medical Center, 820 South Damen Avenue, Chicago, Illinois 60612, USA, USA
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217
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Calabuig-Navarro V, Yamauchi J, Lee S, Zhang T, Liu YZ, Sadlek K, Coudriet GM, Piganelli JD, Jiang CL, Miller R, Lowe M, Harashima H, Dong HH. Forkhead Box O6 (FoxO6) Depletion Attenuates Hepatic Gluconeogenesis and Protects against Fat-induced Glucose Disorder in Mice. J Biol Chem 2015; 290:15581-15594. [PMID: 25944898 DOI: 10.1074/jbc.m115.650994] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Indexed: 12/22/2022] Open
Abstract
Excessive endogenous glucose production contributes to fasting hyperglycemia in diabetes. FoxO6 is a distinct member of the FoxO subfamily. To elucidate the role of FoxO6 in hepatic gluconeogenesis and assess its contribution to the pathogenesis of fasting hyperglycemia in diabetes, we generated FoxO6 knock-out (FoxO6-KO) mice followed by determining the effect of FoxO6 loss-of-function on hepatic gluconeogenesis under physiological and pathological conditions. FoxO6 depletion attenuated hepatic gluconeogenesis and lowered fasting glycemia in FoxO6-KO mice. FoxO6-deficient primary hepatocytes were associated with reduced capacities to produce glucose in response to glucagon. When fed a high fat diet, FoxO6-KO mice exhibited significantly enhanced glucose tolerance and reduced blood glucose levels accompanied by improved insulin sensitivity. These effects correlated with attenuated hepatic gluconeogenesis in FoxO6-KO mice. In contrast, wild-type littermates developed fat-induced glucose intolerance with a concomitant induction of fasting hyperinsulinemia and hyperglycemia. Furthermore, FoxO6-KO mice displayed significantly diminished macrophage infiltration into liver and adipose tissues, correlating with the reduction of macrophage expression of C-C chemokine receptor 2 (CCR2), a factor that is critical for regulating macrophage recruitment in peripheral tissues. Our data indicate that FoxO6 depletion protected against diet-induced glucose intolerance and insulin resistance by attenuating hepatic gluconeogenesis and curbing macrophage infiltration in liver and adipose tissues in mice.
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Affiliation(s)
- Virtu Calabuig-Navarro
- Department of Pediatrics, Children's Hospital of Pittsburgh of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15224
| | - Jun Yamauchi
- Department of Pediatrics, Children's Hospital of Pittsburgh of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15224; Laboratory for Molecular Design of Pharmaceutics, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Hokkaido 060-0812, Japan
| | - Sojin Lee
- Department of Pediatrics, Children's Hospital of Pittsburgh of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15224
| | - Ting Zhang
- Department of Pediatrics, Children's Hospital of Pittsburgh of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15224
| | - Yun-Zi Liu
- Department of Pediatrics, Children's Hospital of Pittsburgh of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15224; Laboratory of Stress Medicine, Faculty of Psychology and Mental Health, Second Military Medical University, 200433 Shanghai, China
| | - Kelsey Sadlek
- Department of Pediatrics, Children's Hospital of Pittsburgh of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15224
| | - Gina M Coudriet
- Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15224
| | - Jon D Piganelli
- Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15224
| | - Chun-Lei Jiang
- Laboratory of Stress Medicine, Faculty of Psychology and Mental Health, Second Military Medical University, 200433 Shanghai, China
| | - Rita Miller
- Department of Pediatrics, Children's Hospital of Pittsburgh of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15224
| | - Mark Lowe
- Department of Pediatrics, Children's Hospital of Pittsburgh of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15224
| | - Hideyoshi Harashima
- Laboratory for Molecular Design of Pharmaceutics, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Hokkaido 060-0812, Japan
| | - H Henry Dong
- Department of Pediatrics, Children's Hospital of Pittsburgh of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15224.
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218
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Miao J, Ling AV, Manthena PV, Gearing ME, Graham MJ, Crooke RM, Croce KJ, Esquejo RM, Clish CB, Vicent D, Biddinger SB. Flavin-containing monooxygenase 3 as a potential player in diabetes-associated atherosclerosis. Nat Commun 2015; 6:6498. [PMID: 25849138 PMCID: PMC4391288 DOI: 10.1038/ncomms7498] [Citation(s) in RCA: 261] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 02/03/2015] [Indexed: 02/08/2023] Open
Abstract
Despite the well-documented association between insulin resistance and cardiovascular disease, the key targets of insulin relevant to the development of cardiovascular disease are not known. Here, using non-biased profiling methods, we identify the enzyme flavin-containing monooxygenase 3 (Fmo3) to be a target of insulin. FMO3 produces trimethylamine N-oxide (TMAO), which has recently been suggested to promote atherosclerosis in mice and humans. We show that FMO3 is suppressed by insulin in vitro, increased in obese/insulin resistant male mice and increased in obese/insulin-resistant humans. Knockdown of FMO3 in insulin-resistant mice suppresses FoxO1, a central node for metabolic control, and entirely prevents the development of hyperglycaemia, hyperlipidemia and atherosclerosis. Taken together, these data indicate that FMO3 is required for FoxO1 expression and the development of metabolic dysfunction.
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Affiliation(s)
- Ji Miao
- Division of Endocrinology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Alisha V. Ling
- Division of Endocrinology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Praveen V. Manthena
- Division of Endocrinology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Mary E. Gearing
- Division of Endocrinology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | | | | | - Kevin J. Croce
- Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Ryan M. Esquejo
- Metabolic Disease Program and Diabetes and Obesity Center, Sanford-Burnham Medical Research Institute, Orlando, Florida, USA
| | | | - David Vicent
- Department of Endocrinology and Nutrition, Hospital Carlos III, Madrid 28029, Spain
- Instituto de Investigación Sanitaria del Hospital Universitario La Paz (IdiPAZ), Madrid 28046, Spain
| | - Sudha B. Biddinger
- Division of Endocrinology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
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219
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Deng Y, Kerdiles Y, Chu J, Yuan S, Wang Y, Chen X, Mao H, Zhang L, Zhang J, Hughes T, Deng Y, Zhang Q, Wang F, Zou X, Liu CG, Freud AG, Li X, Caligiuri MA, Vivier E, Yu J. Transcription factor Foxo1 is a negative regulator of natural killer cell maturation and function. Immunity 2015; 42:457-70. [PMID: 25769609 DOI: 10.1016/j.immuni.2015.02.006] [Citation(s) in RCA: 115] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2014] [Revised: 12/23/2014] [Accepted: 01/06/2015] [Indexed: 01/01/2023]
Abstract
Little is known about the role of negative regulators in controlling natural killer (NK) cell development and effector functions. Foxo1 is a multifunctional transcription factor of the forkhead family. Using a mouse model of conditional deletion in NK cells, we found that Foxo1 negatively controlled NK cell differentiation and function. Immature NK cells expressed abundant Foxo1 and little Tbx21 relative to mature NK cells, but these two transcription factors reversed their expression as NK cells proceeded through development. Foxo1 promoted NK cell homing to lymph nodes by upregulating CD62L expression and inhibited late-stage maturation and effector functions by repressing Tbx21 expression. Loss of Foxo1 rescued the defect in late-stage NK cell maturation in heterozygous Tbx21(+/-) mice. Collectively, our data reveal a regulatory pathway by which the negative regulator Foxo1 and the positive regulator Tbx21 play opposing roles in controlling NK cell development and effector functions.
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Affiliation(s)
- Youcai Deng
- Division of Hematology, Department of Internal Medicine, College of Medicine, The Ohio State University, Columbus, OH 43210, USA; Institute of Materia Medica, College of Pharmacy, Third Military Medical University, Chongqing 400038, China; The Ohio State University Comprehensive Cancer Center, Columbus, OH 43210, USA
| | - Yann Kerdiles
- Centre d'Immunologie de Marseille-Luminy, Aix-Marseille University UM2, Inserm U1104, CNRS UMR7280, Marseille 13288, France
| | - Jianhong Chu
- The Ohio State University Comprehensive Cancer Center, Columbus, OH 43210, USA
| | - Shunzong Yuan
- The Ohio State University Comprehensive Cancer Center, Columbus, OH 43210, USA; Department of Lymphoma, Affiliated Hospital of Academy of Military Medical Sciences, Beijing 100071, China
| | - Youwei Wang
- The Ohio State University Comprehensive Cancer Center, Columbus, OH 43210, USA
| | - Xilin Chen
- The Ohio State University Comprehensive Cancer Center, Columbus, OH 43210, USA; Department of Lymphoma, Affiliated Hospital of Academy of Military Medical Sciences, Beijing 100071, China
| | - Hsiaoyin Mao
- The Ohio State University Comprehensive Cancer Center, Columbus, OH 43210, USA
| | - Lingling Zhang
- The Ohio State University Comprehensive Cancer Center, Columbus, OH 43210, USA
| | - Jianying Zhang
- Center for Biostatistics, The Ohio State University, Columbus, OH 43210, USA
| | - Tiffany Hughes
- The Ohio State University Comprehensive Cancer Center, Columbus, OH 43210, USA
| | - Yafei Deng
- Institute of Materia Medica, College of Pharmacy, Third Military Medical University, Chongqing 400038, China
| | - Qi Zhang
- Institute of Materia Medica, College of Pharmacy, Third Military Medical University, Chongqing 400038, China
| | - Fangjie Wang
- Institute of Materia Medica, College of Pharmacy, Third Military Medical University, Chongqing 400038, China
| | - Xianghong Zou
- The Ohio State University Comprehensive Cancer Center, Columbus, OH 43210, USA
| | - Chang-Gong Liu
- Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Aharon G Freud
- The Ohio State University Comprehensive Cancer Center, Columbus, OH 43210, USA
| | - Xiaohui Li
- Institute of Materia Medica, College of Pharmacy, Third Military Medical University, Chongqing 400038, China
| | - Michael A Caligiuri
- Division of Hematology, Department of Internal Medicine, College of Medicine, The Ohio State University, Columbus, OH 43210, USA; The Ohio State University Comprehensive Cancer Center, Columbus, OH 43210, USA; The James Cancer Hospital, The Ohio State University, Columbus, OH 43210, USA.
| | - Eric Vivier
- Centre d'Immunologie de Marseille-Luminy, Aix-Marseille University UM2, Inserm U1104, CNRS UMR7280, Marseille 13288, France; Service d'Immunologie, Assistance Publique - Hôpitaux de Marseille, Marseille 13385, France
| | - Jianhua Yu
- Division of Hematology, Department of Internal Medicine, College of Medicine, The Ohio State University, Columbus, OH 43210, USA; The Ohio State University Comprehensive Cancer Center, Columbus, OH 43210, USA; The James Cancer Hospital, The Ohio State University, Columbus, OH 43210, USA.
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220
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Gregory AD, Kliment CR, Metz HE, Kim KH, Kargl J, Agostini BA, Crum LT, Oczypok EA, Oury TA, Houghton AM. Neutrophil elastase promotes myofibroblast differentiation in lung fibrosis. J Leukoc Biol 2015; 98:143-52. [PMID: 25743626 DOI: 10.1189/jlb.3hi1014-493r] [Citation(s) in RCA: 139] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Accepted: 01/29/2015] [Indexed: 12/23/2022] Open
Abstract
IPF is a progressive lung disorder characterized by fibroblast proliferation and myofibroblast differentiation. Although neutrophil accumulation within IPF lungs has been negatively correlated with outcomes, the role played by neutrophils in lung fibrosis remains poorly understood. We have demonstrated previously that NE promotes lung cancer cell proliferation and hypothesized that it may have a similar effect on fibroblasts. In the current study, we show that NE(-/-) mice are protected from asbestos-induced lung fibrosis. NE(-/-) mice displayed reduced fibroblast and myofibroblast content when compared with controls. NE directly both lung fibroblast proliferation and myofibroblast differentiation in vitro, as evidenced by proliferation assays, collagen gel contractility assays, and αSMA induction. Furthermore, αSMA induction occurs in a TGF-β-independent fashion. Treatment of asbestos-recipient mice with ONO-5046, a synthetic NE antagonist, reduced hydroxyproline content. Thus, the current study points to a key role for neutrophils and NE in the progression of lung fibrosis. Lastly, the study lends rationale to use of NE-inhibitory approaches as a novel therapeutic strategy for patients with lung fibrosis.
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Affiliation(s)
- Alyssa D Gregory
- Departments of *Medicine and Pathology, Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA; Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA; and Division of Pulmonary and Critical Care, University of Washington, Seattle, Washington, USA
| | - Corrine R Kliment
- Departments of *Medicine and Pathology, Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA; Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA; and Division of Pulmonary and Critical Care, University of Washington, Seattle, Washington, USA
| | - Heather E Metz
- Departments of *Medicine and Pathology, Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA; Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA; and Division of Pulmonary and Critical Care, University of Washington, Seattle, Washington, USA
| | - Kyoung-Hee Kim
- Departments of *Medicine and Pathology, Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA; Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA; and Division of Pulmonary and Critical Care, University of Washington, Seattle, Washington, USA
| | - Julia Kargl
- Departments of *Medicine and Pathology, Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA; Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA; and Division of Pulmonary and Critical Care, University of Washington, Seattle, Washington, USA
| | - Brittani A Agostini
- Departments of *Medicine and Pathology, Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA; Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA; and Division of Pulmonary and Critical Care, University of Washington, Seattle, Washington, USA
| | - Lauren T Crum
- Departments of *Medicine and Pathology, Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA; Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA; and Division of Pulmonary and Critical Care, University of Washington, Seattle, Washington, USA
| | - Elizabeth A Oczypok
- Departments of *Medicine and Pathology, Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA; Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA; and Division of Pulmonary and Critical Care, University of Washington, Seattle, Washington, USA
| | - Tim A Oury
- Departments of *Medicine and Pathology, Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA; Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA; and Division of Pulmonary and Critical Care, University of Washington, Seattle, Washington, USA
| | - A McGarry Houghton
- Departments of *Medicine and Pathology, Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA; Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA; and Division of Pulmonary and Critical Care, University of Washington, Seattle, Washington, USA
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221
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Karadag AS, Takci Z, Ertugrul DT, Bilgili SG, Balahoroglu R, Takir M. The Effect of Different Doses of Isotretinoin on Pituitary Hormones. Dermatology 2015; 230:354-9. [DOI: 10.1159/000375370] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 01/19/2015] [Indexed: 11/19/2022] Open
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222
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Zhou J, Wang Q, Ding Y, Zou MH. Hypochlorous acid via peroxynitrite activates protein kinase Cθ and insulin resistance in adipocytes. J Mol Endocrinol 2015; 54:25-37. [PMID: 25381390 PMCID: PMC4261204 DOI: 10.1530/jme-14-0213] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
We recently reported that genetic deletion of myeloperoxidase (MPO) alleviates obesity-related insulin resistance in mice in vivo. How MPO impairs insulin sensitivity in adipocytes is poorly characterized. As hypochlorous acid (HOCl) is a principal oxidant product generated by MPO, we evaluated the effects of HOCl on insulin signaling in adipocytes differentiated from 3T3-L1 cells. Exposure of 3T3-L1 adipocytes to exogenous HOCl (200 μmol/l) attenuated insulin-stimulated 2-deoxyglucose uptake, GLUT4 translocation, and insulin signals, including tyrosine phosphorylation of insulin receptor substrate 1 (IRS1) and phosphorylation of Akt. Furthermore, treatment with HOCl induced phosphorylation of IRS1 at serine 307, inhibitor κB kinase (IKK), c-Jun NH2-terminal kinase (JNK), and phosphorylation of PKCθ (PKCθ). In addition, genetic and pharmacological inhibition of IKK and JNK abolished serine phosphorylation of IRS1 and impairment of insulin signaling by HOCl. Furthermore, knockdown of PKCθ using siRNA transfection suppressed phosphorylation of IKK and JNK and consequently attenuated the HOCl-impaired insulin signaling pathway. Moreover, activation of PKCθ by peroxynitrite was accompanied by increased phosphorylation of IKK, JNK, and IRS1-serine 307. In contrast, ONOO(-) inhibitors abolished HOCl-induced phosphorylation of PKCθ, IKK, JNK, and IRS1-serine 307, as well as insulin resistance. Finally, high-fat diet (HFD)-induced insulin resistance was associated with enhanced phosphorylation of PKCθ, IKK, JNK, and IRS1 at serine 307 in white adipose tissues from WT mice, all of which were not found in Mpo knockout mice fed HFDs. We conclude that HOCl impairs insulin signaling pathway by increasing ONOO(-) mediated phosphorylation of PKCθ, resulting in phosphorylation of IKK/JNK and consequent serine phosphorylation of IRS1 in adipocytes.
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Affiliation(s)
- Jun Zhou
- Section of Molecular MedicineBSEB 306A, Department of Internal Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
| | - Qilong Wang
- Section of Molecular MedicineBSEB 306A, Department of Internal Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
| | - Ye Ding
- Section of Molecular MedicineBSEB 306A, Department of Internal Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
| | - Ming-Hui Zou
- Section of Molecular MedicineBSEB 306A, Department of Internal Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
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223
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Obrochta KM, Krois CR, Campos B, Napoli JL. Insulin regulates retinol dehydrogenase expression and all-trans-retinoic acid biosynthesis through FoxO1. J Biol Chem 2015; 290:7259-68. [PMID: 25627686 DOI: 10.1074/jbc.m114.609313] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
All-trans-retinoic acid (atRA), an autacoid derived from retinol (vitamin A), regulates energy balance and reduces adiposity. We show that energy status regulates atRA biosynthesis at the rate-limiting step, catalyzed by retinol dehydrogenases (RDH). Six h after re-feeding, Rdh1 expression decreased 80-90% in liver and brown adipose tissue and Rdh10 expression was decreased 45-63% in liver, pancreas, and kidney, all relative to mice fasted 16 h. atRA in the liver was decreased 44% 3 h after reduced Rdh expression. Oral gavage with glucose or injection with insulin decreased Rdh1 and Rdh10 mRNA 50% or greater in mouse liver. Removing serum from the medium of the human hepatoma cell line HepG2 increased Rdh10 and Rdh16 (human Rdh1 ortholog) mRNA expression 2-3-fold by 4 h, by increasing transcription and stabilizing mRNA. Insulin decreased Rdh10 and Rdh16 mRNA in HepG2 cells incubated in serum-free medium by inhibiting transcription and destabilizing mRNA. Insulin action required PI3K and Akt, which suppress FoxO1. Serum removal increased atRA biosynthesis 4-fold from retinol in HepG2 cells, whereas dominant-negative FoxO1 prevented the increase. Thus, energy status via insulin and FoxO1 regulate Rdh expression and atRA biosynthesis. These results reveal mechanisms for regulating atRA biosynthesis and the opposing effects of atRA and insulin on gluconeogenesis, and also suggest an interaction between atRA and insulin signaling related diseases, such as type II diabetes and cancer.
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Affiliation(s)
- Kristin M Obrochta
- From the Department of Nutritional Sciences and Toxicology, Graduate Program in Metabolic Biology, University of California, Berkeley, California 94720
| | - Charles R Krois
- From the Department of Nutritional Sciences and Toxicology, Graduate Program in Metabolic Biology, University of California, Berkeley, California 94720
| | - Benito Campos
- From the Department of Nutritional Sciences and Toxicology, Graduate Program in Metabolic Biology, University of California, Berkeley, California 94720
| | - Joseph L Napoli
- From the Department of Nutritional Sciences and Toxicology, Graduate Program in Metabolic Biology, University of California, Berkeley, California 94720
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Bedinger DH, Goldfine ID, Corbin JA, Roell MK, Adams SH. Differential pathway coupling of the activated insulin receptor drives signaling selectivity by XMetA, an allosteric partial agonist antibody. J Pharmacol Exp Ther 2015; 353:35-43. [PMID: 25613982 DOI: 10.1124/jpet.114.221309] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The monoclonal antibody XMetA is an allosteric partial agonist of the insulin receptor (IR), which activates the metabolic Akt kinase signaling pathway while having little or no effect on the mitogenic extracellular signal-regulated kinase (ERK) signaling pathway. To investigate the nature of this selective signaling, we have conducted a detailed investigation of XMetA to evaluate specific phosphorylation and activation of IR, Akt, and ERK in Chinese hamster ovary cell lines expressing either the short or long isoform of the human IR. Insulin activated both pathways, but the phosphorylation of Akt was more sensitive to the hormone than the phosphorylation of ERK. Maximally effective concentrations of XMetA elicited phosphorylation patterns similar to 40-100 pM insulin, which were sufficient for robust Akt phosphorylation, but had little effect on ERK phosphorylation. These data indicate that the preferential signaling of XMetA is due to an innate difference in pathway sensitivity of Akt versus ERK responses to IR activation and partial agonism by XMetA, rather than a separate pathway-biased mechanism. The metabolic selectivity of partial IR agonists like XMetA, if recapitulated in vivo, may be a desirable feature of therapeutic agents designed to regulate blood glucose levels while minimizing undesirable outcomes of excessive IR mitogenic activation.
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Affiliation(s)
- Daniel H Bedinger
- XOMA Corporation, Berkeley, California (D.H.B., I.D.G., J.A.C., M.K.R.); Obesity & Metabolism Research Unit, United States Department of Agriculture-Agricultural Research Service Western Human Nutrition Research Center and Department of Nutrition, Davis, California (S.H.A.); and Molecular, Cellular and Integrative Physiology Graduate Group, University of California at Davis, Davis, California (D.H.B., S.H.A.)
| | - Ira D Goldfine
- XOMA Corporation, Berkeley, California (D.H.B., I.D.G., J.A.C., M.K.R.); Obesity & Metabolism Research Unit, United States Department of Agriculture-Agricultural Research Service Western Human Nutrition Research Center and Department of Nutrition, Davis, California (S.H.A.); and Molecular, Cellular and Integrative Physiology Graduate Group, University of California at Davis, Davis, California (D.H.B., S.H.A.)
| | - John A Corbin
- XOMA Corporation, Berkeley, California (D.H.B., I.D.G., J.A.C., M.K.R.); Obesity & Metabolism Research Unit, United States Department of Agriculture-Agricultural Research Service Western Human Nutrition Research Center and Department of Nutrition, Davis, California (S.H.A.); and Molecular, Cellular and Integrative Physiology Graduate Group, University of California at Davis, Davis, California (D.H.B., S.H.A.)
| | - Marina K Roell
- XOMA Corporation, Berkeley, California (D.H.B., I.D.G., J.A.C., M.K.R.); Obesity & Metabolism Research Unit, United States Department of Agriculture-Agricultural Research Service Western Human Nutrition Research Center and Department of Nutrition, Davis, California (S.H.A.); and Molecular, Cellular and Integrative Physiology Graduate Group, University of California at Davis, Davis, California (D.H.B., S.H.A.)
| | - Sean H Adams
- XOMA Corporation, Berkeley, California (D.H.B., I.D.G., J.A.C., M.K.R.); Obesity & Metabolism Research Unit, United States Department of Agriculture-Agricultural Research Service Western Human Nutrition Research Center and Department of Nutrition, Davis, California (S.H.A.); and Molecular, Cellular and Integrative Physiology Graduate Group, University of California at Davis, Davis, California (D.H.B., S.H.A.)
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225
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Tamoxifen reduces fat mass by boosting reactive oxygen species. Cell Death Dis 2015; 6:e1586. [PMID: 25569103 PMCID: PMC4669751 DOI: 10.1038/cddis.2014.553] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Revised: 11/10/2014] [Accepted: 11/17/2014] [Indexed: 01/04/2023]
Abstract
As the pandemic of obesity is growing, a variety of animal models have been generated to study the mechanisms underlying the increased adiposity and development of metabolic disorders. Tamoxifen (Tam) is widely used to activate Cre recombinase that spatiotemporally controls target gene expression and regulates adiposity in laboratory animals. However, a critical question remains as to whether Tam itself affects adiposity and possibly confounds the functional study of target genes in adipose tissue. Here we administered Tam to Cre-absent forkhead box O1 (FoxO1) floxed mice (f-FoxO1) and insulin receptor substrate Irs1/Irs2 double floxed mice (df-Irs) and found that Tam induced approximately 30% reduction (P<0.05) in fat mass with insignificant change in body weight. Mechanistically, Tam promoted reactive oxygen species (ROS) production, apoptosis and autophagy, which was associated with downregulation of adipogenic regulator peroxisome proliferator-activated receptor gamma and dedifferentiation of mature adipocytes. However, normalization of ROS potently suppressed Tam-induced apoptosis, autophagy and adipocyte dedifferentiation, suggesting that ROS may account, at least in part, for the changes. Importantly, Tam-induced ROS production and fat mass reduction lasted for 4–5 weeks in the f-FoxO1 and df-Irs mice. Our data suggest that Tam reduces fat mass via boosting ROS, thus making a recovery period crucial for posttreatment study.
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226
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Abstract
The liver is an essential metabolic organ, and its metabolic function is controlled by insulin and other metabolic hormones. Glucose is converted into pyruvate through glycolysis in the cytoplasm, and pyruvate is subsequently oxidized in the mitochondria to generate ATP through the TCA cycle and oxidative phosphorylation. In the fed state, glycolytic products are used to synthesize fatty acids through de novo lipogenesis. Long-chain fatty acids are incorporated into triacylglycerol, phospholipids, and/or cholesterol esters in hepatocytes. These complex lipids are stored in lipid droplets and membrane structures, or secreted into the circulation as very low-density lipoprotein particles. In the fasted state, the liver secretes glucose through both glycogenolysis and gluconeogenesis. During pronged fasting, hepatic gluconeogenesis is the primary source for endogenous glucose production. Fasting also promotes lipolysis in adipose tissue, resulting in release of nonesterified fatty acids which are converted into ketone bodies in hepatic mitochondria though β-oxidation and ketogenesis. Ketone bodies provide a metabolic fuel for extrahepatic tissues. Liver energy metabolism is tightly regulated by neuronal and hormonal signals. The sympathetic system stimulates, whereas the parasympathetic system suppresses, hepatic gluconeogenesis. Insulin stimulates glycolysis and lipogenesis but suppresses gluconeogenesis, and glucagon counteracts insulin action. Numerous transcription factors and coactivators, including CREB, FOXO1, ChREBP, SREBP, PGC-1α, and CRTC2, control the expression of the enzymes which catalyze key steps of metabolic pathways, thus controlling liver energy metabolism. Aberrant energy metabolism in the liver promotes insulin resistance, diabetes, and nonalcoholic fatty liver diseases.
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Affiliation(s)
- Liangyou Rui
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan
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227
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Qi Y, Zhu Q, Zhang K, Thomas C, Wu Y, Kumar R, Baker KM, Xu Z, Chen S, Guo S. Activation of Foxo1 by insulin resistance promotes cardiac dysfunction and β-myosin heavy chain gene expression. Circ Heart Fail 2014; 8:198-208. [PMID: 25477432 DOI: 10.1161/circheartfailure.114.001457] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
BACKGROUND Heart failure is a leading cause of morbidity and mortality in the USA and is closely associated with diabetes mellitus. The molecular link between diabetes mellitus and heart failure is incompletely understood. We recently demonstrated that insulin receptor substrates 1, 2 (IRS1, 2) are key components of insulin signaling and loss of IRS1 and IRS2 mediates insulin resistance, resulting in metabolic dysregulation and heart failure, which is associated with downstream Akt inactivation and in turn activation of the forkhead transcription factor Foxo1. METHODS AND RESULTS To determine the role of Foxo1 in control of heart failure in insulin resistance and diabetes mellitus, we generated mice lacking Foxo1 gene specifically in the heart. Mice lacking both IRS1 and IRS2 in adult hearts exhibited severe heart failure and a remarkable increase in the β-isoform of myosin heavy chain (β-MHC) gene expression, whereas deletion of cardiac Foxo1 gene largely prevented the heart failure and resulted in a decrease in β-MHC expression. The effect of Foxo1 deficiency on rescuing cardiac dysfunction was also observed in db/db mice and high-fat diet mice. Using cultures of primary ventricular cardiomyocytes, we found that Foxo1 interacts with the promoter region of β-MHC and stimulates gene expression, mediating an effect of insulin that suppresses β-MHC expression. CONCLUSIONS Our study suggests that Foxo1 has important roles in promoting diabetic cardiomyopathy and controls β-MHC expression in the development of cardiac dysfunction. Targeting Foxo1 and its regulation will provide novel strategies in preventing metabolic and myocardial dysfunction and influencing MHC plasticity in diabetes mellitus.
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Affiliation(s)
- Yajuan Qi
- From the Division of Molecular Cardiology, Department of Medicine, College of Medicine, Texas A&M University Health Science Center, Baylor Scott & White Health, Central Texas Veterans Health Care System, Temple (Y.Q., Q.Z., K.Z., C.T., Y.W., R.K., K.M.B., Z.X., S.C., S.G.); and Department of Pharmacology, Hebei United University, Tangshan, China (Y.Q.)
| | - Qinglei Zhu
- From the Division of Molecular Cardiology, Department of Medicine, College of Medicine, Texas A&M University Health Science Center, Baylor Scott & White Health, Central Texas Veterans Health Care System, Temple (Y.Q., Q.Z., K.Z., C.T., Y.W., R.K., K.M.B., Z.X., S.C., S.G.); and Department of Pharmacology, Hebei United University, Tangshan, China (Y.Q.)
| | - Kebin Zhang
- From the Division of Molecular Cardiology, Department of Medicine, College of Medicine, Texas A&M University Health Science Center, Baylor Scott & White Health, Central Texas Veterans Health Care System, Temple (Y.Q., Q.Z., K.Z., C.T., Y.W., R.K., K.M.B., Z.X., S.C., S.G.); and Department of Pharmacology, Hebei United University, Tangshan, China (Y.Q.)
| | - Candice Thomas
- From the Division of Molecular Cardiology, Department of Medicine, College of Medicine, Texas A&M University Health Science Center, Baylor Scott & White Health, Central Texas Veterans Health Care System, Temple (Y.Q., Q.Z., K.Z., C.T., Y.W., R.K., K.M.B., Z.X., S.C., S.G.); and Department of Pharmacology, Hebei United University, Tangshan, China (Y.Q.)
| | - Yuxin Wu
- From the Division of Molecular Cardiology, Department of Medicine, College of Medicine, Texas A&M University Health Science Center, Baylor Scott & White Health, Central Texas Veterans Health Care System, Temple (Y.Q., Q.Z., K.Z., C.T., Y.W., R.K., K.M.B., Z.X., S.C., S.G.); and Department of Pharmacology, Hebei United University, Tangshan, China (Y.Q.)
| | - Rajesh Kumar
- From the Division of Molecular Cardiology, Department of Medicine, College of Medicine, Texas A&M University Health Science Center, Baylor Scott & White Health, Central Texas Veterans Health Care System, Temple (Y.Q., Q.Z., K.Z., C.T., Y.W., R.K., K.M.B., Z.X., S.C., S.G.); and Department of Pharmacology, Hebei United University, Tangshan, China (Y.Q.)
| | - Kenneth M Baker
- From the Division of Molecular Cardiology, Department of Medicine, College of Medicine, Texas A&M University Health Science Center, Baylor Scott & White Health, Central Texas Veterans Health Care System, Temple (Y.Q., Q.Z., K.Z., C.T., Y.W., R.K., K.M.B., Z.X., S.C., S.G.); and Department of Pharmacology, Hebei United University, Tangshan, China (Y.Q.)
| | - Zihui Xu
- From the Division of Molecular Cardiology, Department of Medicine, College of Medicine, Texas A&M University Health Science Center, Baylor Scott & White Health, Central Texas Veterans Health Care System, Temple (Y.Q., Q.Z., K.Z., C.T., Y.W., R.K., K.M.B., Z.X., S.C., S.G.); and Department of Pharmacology, Hebei United University, Tangshan, China (Y.Q.)
| | - Shouwen Chen
- From the Division of Molecular Cardiology, Department of Medicine, College of Medicine, Texas A&M University Health Science Center, Baylor Scott & White Health, Central Texas Veterans Health Care System, Temple (Y.Q., Q.Z., K.Z., C.T., Y.W., R.K., K.M.B., Z.X., S.C., S.G.); and Department of Pharmacology, Hebei United University, Tangshan, China (Y.Q.)
| | - Shaodong Guo
- From the Division of Molecular Cardiology, Department of Medicine, College of Medicine, Texas A&M University Health Science Center, Baylor Scott & White Health, Central Texas Veterans Health Care System, Temple (Y.Q., Q.Z., K.Z., C.T., Y.W., R.K., K.M.B., Z.X., S.C., S.G.); and Department of Pharmacology, Hebei United University, Tangshan, China (Y.Q.).
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Nakagawa Y, Satoh A, Yabe S, Furusawa M, Tokushige N, Tezuka H, Mikami M, Iwata W, Shingyouchi A, Matsuzaka T, Kiwata S, Fujimoto Y, Shimizu H, Danno H, Yamamoto T, Ishii K, Karasawa T, Takeuchi Y, Iwasaki H, Shimada M, Kawakami Y, Urayama O, Sone H, Takekoshi K, Kobayashi K, Yatoh S, Takahashi A, Yahagi N, Suzuki H, Yamada N, Shimano H. Hepatic CREB3L3 controls whole-body energy homeostasis and improves obesity and diabetes. Endocrinology 2014; 155:4706-19. [PMID: 25233440 DOI: 10.1210/en.2014-1113] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Transcriptional regulation of metabolic genes in the liver is the key to maintaining systemic energy homeostasis during starvation. The membrane-bound transcription factor cAMP-responsive element-binding protein 3-like 3 (CREB3L3) has been reported to be activated during fasting and to regulate triglyceride metabolism. Here, we show that CREB3L3 confers a wide spectrum of metabolic responses to starvation in vivo. Adenoviral and transgenic overexpression of nuclear CREB3L3 induced systemic lipolysis, hepatic ketogenesis, and insulin sensitivity with increased energy expenditure, leading to marked reduction in body weight, plasma lipid levels, and glucose levels. CREB3L3 overexpression activated gene expression levels and plasma levels of antidiabetic hormones, including fibroblast growth factor 21 and IGF-binding protein 2. Amelioration of diabetes by hepatic activation of CREB3L3 was also observed in several types of diabetic obese mice. Nuclear CREB3L3 mutually activates the peroxisome proliferator-activated receptor (PPAR) α promoter in an autoloop fashion and is crucial for the ligand transactivation of PPARα by interacting with its transcriptional regulator, peroxisome proliferator-activated receptor gamma coactivator-1α. CREB3L3 directly and indirectly controls fibroblast growth factor 21 expression and its plasma level, which contributes at least partially to the catabolic effects of CREB3L3 on systemic energy homeostasis in the entire body. Therefore, CREB3L3 is a therapeutic target for obesity and diabetes.
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Affiliation(s)
- Yoshimi Nakagawa
- Department of Internal Medicine (Endocrinology and Metabolism) (Y.N., A.Sa., S.Yab., M.F., N.T., H.T., M.M., W.I., A.Sh., T.M., S.K., Y.F., H.Shimi., H.D., T.Y., K.I., T.K., Y.T., H.I., M.S., Y.K., O.U., H.So., K.T., K.K., S.Yat., A.T., N.Yah., H.Su., N.Yam., H.Shima.), Division of Clinical Medicine, Faculty of Medicine, and 2International Institute for Integrative Sleep Medicine (WPI-IIIS) (Y.N., H.Shima.), University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
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Tomasetti M, Nocchi L, Staffolani S, Manzella N, Amati M, Goodwin J, Kluckova K, Nguyen M, Strafella E, Bajzikova M, Peterka M, Lettlova S, Truksa J, Lee W, Dong LF, Santarelli L, Neuzil J. MicroRNA-126 suppresses mesothelioma malignancy by targeting IRS1 and interfering with the mitochondrial function. Antioxid Redox Signal 2014; 21:2109-25. [PMID: 24444362 PMCID: PMC4215384 DOI: 10.1089/ars.2013.5215] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
AIMS MiR126 was found to be frequently lost in many types of cancer, including malignant mesothelioma (MM), which represents one of the most challenging neoplastic diseases. In this study, we investigated the potential tumor suppressor function of MiR126 in MM cells. The effect of MiR126 was examined in response to oxidative stress, aberrant mitochondrial function induced by inhibition of complex I, mitochondrial DNA (mtDNA) depletion, and hypoxia. RESULTS MiR126 was up-regulated by oxidative stress in nonmalignant mesothelial (Met5A) and MM (H28) cell lines. In Met5A cells, rotenone inhibited MiR126 expression, but mtDNA depletion and hypoxia up-regulated MiR126. However, these various stimuli suppressed the levels of MiR126 in H28 cells. MiR126 affected mitochondrial energy metabolism, reduced mitochondrial respiration, and promoted glycolysis in H28 cells. This metabolic shift, associated with insulin receptor substrate-1 (IRS1)-modulated ATP-citrate lyase deregulation, resulted in higher ATP and citrate production. These changes were linked to the down-regulation of IRS1 by ectopic MiR126, reducing Akt signaling and inhibiting cytosolic sequestration of Forkhead box O1 (FoxO1), which promoted the expression of genes involved in gluconeogenesis and oxidative stress defense. These metabolic changes induced hypoxia-inducible factor-1α (HIF1α) stabilization. Consequently, MiR126 suppressed the malignancy of MM cells in vitro, a notion corroborated by the failure of H28(MiR126) cells to form tumors in nude mice. INNOVATION AND CONCLUSION MiR126 affects mitochondrial energy metabolism, resulting in MM tumor suppression. Since MM is a fatal neoplastic disease with a few therapeutic options, this finding is of potential translational importance.
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Affiliation(s)
- Marco Tomasetti
- 1 Department of Clinical and Molecular Science, Polytechnic University of Marche , Ancona, Italy
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230
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MicroRNA regulation of cancer metabolism: role in tumour suppression. Mitochondrion 2014; 19 Pt A:29-38. [DOI: 10.1016/j.mito.2014.06.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2014] [Revised: 06/16/2014] [Accepted: 06/17/2014] [Indexed: 12/18/2022]
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231
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Haeusler RA, Hartil K, Vaitheesvaran B, Arrieta-Cruz I, Knight CM, Cook JR, Kammoun HL, Febbraio MA, Gutierrez-Juarez R, Kurland IJ, Accili D. Integrated control of hepatic lipogenesis versus glucose production requires FoxO transcription factors. Nat Commun 2014; 5:5190. [PMID: 25307742 PMCID: PMC4197140 DOI: 10.1038/ncomms6190] [Citation(s) in RCA: 132] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Accepted: 09/08/2014] [Indexed: 12/28/2022] Open
Abstract
Insulin integrates hepatic glucose and lipid metabolism, directing nutrients to storage as glycogen and triglyceride. In type 2 diabetes, levels of the former are low and the latter are exaggerated, posing a pathophysiologic and therapeutic conundrum. A branching model of insulin signaling, with FoxO1 presiding over glucose production and Srebp–1c regulating lipogenesis, provides a potential explanation. Here we illustrate an alternative mechanism that integrates glucose production and lipogenesis under the unifying control of FoxO. Liver–specific ablation of three FoxOs (L–FoxO1,3,4) prevents the induction of glucose–6–phosphatase and the repression of glucokinase during fasting, thus increasing lipogenesis at the expense of glucose production. We document a similar pattern in the early phases of diet-induced insulin resistance, and propose that FoxOs are required to enable the liver to direct nutritionally derived carbons to glucose vs. lipid metabolism. Our data underscore the heterogeneity of hepatic insulin resistance during progression from the metabolic syndrome to overt diabetes, and the conceptual challenge of designing therapies that curtail glucose production without promoting hepatic lipid accumulation.
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Affiliation(s)
- Rebecca A Haeusler
- 1] Department of Pathology and Cell Biology, Columbia University, New York, New York 10032, USA [2] Department of Medicine, Columbia University, New York, New York 10032, USA
| | - Kirsten Hartil
- Department of Medicine, Albert Einstein University, Bronx, New York 10461, USA
| | | | - Isabel Arrieta-Cruz
- Department of Medicine, Albert Einstein University, Bronx, New York 10461, USA
| | - Colette M Knight
- Department of Medicine, Albert Einstein University, Bronx, New York 10461, USA
| | - Joshua R Cook
- Department of Medicine, Columbia University, New York, New York 10032, USA
| | - Helene L Kammoun
- Cellular and Molecular Metabolism Laboratory, Baker IDI Heart and Diabetes Institute, Melbourne, Victoria 3004, Australia
| | - Mark A Febbraio
- Cellular and Molecular Metabolism Laboratory, Baker IDI Heart and Diabetes Institute, Melbourne, Victoria 3004, Australia
| | | | - Irwin J Kurland
- Department of Medicine, Albert Einstein University, Bronx, New York 10461, USA
| | - Domenico Accili
- Department of Medicine, Columbia University, New York, New York 10032, USA
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232
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Tyagi P, Smith PP, Kuchel GA, de Groat WC, Birder LA, Chermansky CJ, Adam RM, Tse V, Chancellor MB, Yoshimura N. Pathophysiology and animal modeling of underactive bladder. Int Urol Nephrol 2014; 46 Suppl 1:S11-21. [PMID: 25238890 DOI: 10.1007/s11255-014-0808-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Accepted: 07/17/2014] [Indexed: 12/17/2022]
Abstract
While the symptomology of underactive bladder (UAB) may imply a primary dysfunction of the detrusor muscle, insights into pathophysiology indicate that both myogenic and neurogenic mechanisms need to be considered. Due to lack of proper animal models, the current understanding of the UAB pathophysiology is limited, and much of what is known about the clinical etiology of the condition has been derived from epidemiological data. We hereby review current state of the art in the understanding of the pathophysiology of and animal models used to study the UAB.
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Affiliation(s)
- Pradeep Tyagi
- Department of Urology, University of Pittsburgh, Pittsburgh, PA, USA
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233
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Kamei Y, Hattori M, Hatazawa Y, Kasahara T, Kanou M, Kanai S, Yuan X, Suganami T, Lamers WH, Kitamura T, Ogawa Y. FOXO1 activates glutamine synthetase gene in mouse skeletal muscles through a region downstream of 3'-UTR: possible contribution to ammonia detoxification. Am J Physiol Endocrinol Metab 2014; 307:E485-93. [PMID: 25074987 DOI: 10.1152/ajpendo.00177.2014] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Skeletal muscle is a reservoir of energy in the form of protein, which is degraded under catabolic conditions, resulting in the formation of amino acids and ammonia as a byproduct. The expression of FOXO1, a forkhead-type transcription factor, increases during starvation and exercise. In agreement, transgenic FOXO1-Tg mice that overexpress FOXO1 in skeletal muscle exhibit muscle atrophy. The aim of this study was to examine the role of FOXO1 in amino acid metabolism. The mRNA and protein expressions of glutamine synthetase (GS) were increased in skeletal muscle of FOXO1-Tg mice. Fasting induced FOXO1 and GS expression in wild-type mice but hardly increased GS expression in muscle-specific FOXO1 knockout (FOXO1-KO) mice. Activation of FOXO1 also increased GS mRNA and protein expression in C2C12 myoblasts. Using a transient transfection reporter assay, we observed that FOXO1 activated the GS reporter construct. Mutation of a putative FOXO1-binding consensus sequence in the downstream genomic region of GS decreased basal and FOXO1-dependent reporter activity significantly. A chromatin immunoprecipitation assay showed that FOXO1 was recruited to the 3' region of GS in C2C12 myoblasts. These results suggest that FOXO1 directly upregulates GS expression. GS is considered to mediate ammonia clearance in skeletal muscle. In agreement, an intravenous ammonia challenge increased blood ammonia concentrations to a twofold higher level in FOXO1-KO than in wild-type mice, demonstrating that the capacity for ammonia disposal correlated inversely with the expression of GS in muscle. These data indicate that FOXO1 plays a role in amino acid metabolism during protein degradation in skeletal muscle.
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Affiliation(s)
- Yasutomi Kamei
- Department of Organ Network and Metabolism and Laboratory of Molecular Nutrition, Graduate School of Environmental and Life Science, Kyoto Prefectural University, Kyoto, Japan;
| | - Maki Hattori
- Department of Molecular Endocrinology and Metabolism, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Yukino Hatazawa
- Department of Molecular Endocrinology and Metabolism, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan; Laboratory of Molecular Nutrition, Graduate School of Environmental and Life Science, Kyoto Prefectural University, Kyoto, Japan
| | - Tomomi Kasahara
- Department of Molecular Endocrinology and Metabolism, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Masanobu Kanou
- Department of Molecular Endocrinology and Metabolism, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Sayaka Kanai
- Department of Molecular Endocrinology and Metabolism, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Xunmei Yuan
- Department of Molecular Endocrinology and Metabolism, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | | | - Wouter H Lamers
- Tytgat Institute for Liver and Intestinal Research, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; and
| | - Tadahiro Kitamura
- Metabolic Signal Research Center, Institute for Molecular and Cellular Regulation, Gunma University, Gunma, Japan
| | - Yoshihiro Ogawa
- Department of Molecular Endocrinology and Metabolism, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
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Insulin receptor substrates are essential for the bioenergetic and hypertrophic response of the heart to exercise training. Mol Cell Biol 2014; 34:3450-60. [PMID: 25002528 DOI: 10.1128/mcb.00426-14] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Insulin and insulin-like growth factor 1 (IGF-1) receptor signaling pathways differentially modulate cardiac growth under resting conditions and following exercise training. These effects are mediated by insulin receptor substrate 1 (IRS1) and IRS2, which also differentially regulate resting cardiac mass. To determine the role of IRS isoforms in mediating the hypertrophic and metabolic adaptations of the heart to exercise training, we subjected mice with cardiomyocyte-specific deletion of either IRS1 (CIRS1 knockout [CIRS1KO] mice) or IRS2 (CIRS2KO mice) to swim training. CIRS1KO hearts were reduced in size under basal conditions, whereas CIRS2KO hearts exhibited hypertrophy. Following exercise swim training in CIRS1KO and CIRS2KO hearts, the hypertrophic response was equivalently attenuated, phosphoinositol 3-kinase (PI3K) activation was blunted, and prohypertrophic signaling intermediates, such as Akt and glycogen synthase kinase 3β (GSK3β), were dephosphorylated potentially on the basis of reduced Janus kinase-mediated inhibition of protein phosphatase 2a (PP2A). Exercise training increased peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) protein content, mitochondrial capacity, fatty acid oxidation, and glycogen synthesis in wild-type (WT) controls but not in IRS1- and IRS2-deficient hearts. PGC-1α protein content remained unchanged in CIRS1KO but decreased in CIRS2KO hearts. These results indicate that although IRS isoforms play divergent roles in the developmental regulation of cardiac size, these isoforms exhibit nonredundant roles in mediating the hypertrophic and metabolic response of the heart to exercise.
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235
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Galbo T, Perry RJ, Nishimura E, Samuel VT, Quistorff B, Shulman GI. PP2A inhibition results in hepatic insulin resistance despite Akt2 activation. Aging (Albany NY) 2014; 5:770-81. [PMID: 24150286 PMCID: PMC3838779 DOI: 10.18632/aging.100611] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
In the liver, insulin suppresses hepatic gluconeogenesis by activating Akt, which inactivates the key gluconeogenic transcription factor FoxO1 (Forkhead Box O1). Recent studies have implicated hyperactivity of the Akt phosphatase Protein Phosphatase 2A (PP2A) and impaired Akt signaling as a molecular defect underlying insulin resistance. We therefore hypothesized that PP2A inhibition would enhance insulin-stimulated Akt activity and decrease glucose production. PP2A inhibitors increased hepatic Akt phosphorylation and inhibited FoxO1 in vitro and in vivo, and suppressed gluconeogenesis in hepatocytes. Paradoxically, PP2A inhibition exacerbated insulin resistance in vivo. This was explained by phosphorylation of both hepatic glycogen synthase (GS) (inactivation) and phosphorylase (activation) resulting in impairment of glycogen storage. Our findings underline the significance of GS and Phosphorylase as hepatic PP2A substrates and importance of glycogen metabolism in acute plasma glucose regulation.
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Affiliation(s)
- Thomas Galbo
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06510, USA
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236
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Landis J, Shaw LM. Insulin receptor substrate 2-mediated phosphatidylinositol 3-kinase signaling selectively inhibits glycogen synthase kinase 3β to regulate aerobic glycolysis. J Biol Chem 2014; 289:18603-13. [PMID: 24811175 DOI: 10.1074/jbc.m114.564070] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Insulin receptor substrate 1 (IRS-1) and IRS-2 are cytoplasmic adaptor proteins that mediate the activation of signaling pathways in response to ligand stimulation of upstream cell surface receptors. Despite sharing a high level of homology and the ability to activate PI3K, only Irs-2 positively regulates aerobic glycolysis in mammary tumor cells. To determine the contribution of Irs-2-dependent PI3K signaling to this selective regulation, we generated an Irs-2 mutant deficient in the recruitment of PI3K. We identified four tyrosine residues (Tyr-649, Tyr-671, Tyr-734, and Tyr-814) that are essential for the association of PI3K with Irs-2 and demonstrate that combined mutation of these tyrosines inhibits glucose uptake and lactate production, two measures of aerobic glycolysis. Irs-2-dependent activation of PI3K regulates the phosphorylation of specific Akt substrates, most notably glycogen synthase kinase 3β (Gsk-3β). Inhibition of Gsk-3β by Irs-2-dependent PI3K signaling promotes glucose uptake and aerobic glycolysis. The regulation of unique subsets of Akt substrates by Irs-1 and Irs-2 may explain their non-redundant roles in mammary tumor biology. Taken together, our study reveals a novel mechanism by which Irs-2 signaling preferentially regulates tumor cell metabolism and adds to our understanding of how this adaptor protein contributes to breast cancer progression.
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Affiliation(s)
- Justine Landis
- From the Department of Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts 01605
| | - Leslie M Shaw
- From the Department of Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts 01605
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237
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Cyphert HA, Alonge KM, Ippagunta SM, Hillgartner FB. Glucagon stimulates hepatic FGF21 secretion through a PKA- and EPAC-dependent posttranscriptional mechanism. PLoS One 2014; 9:e94996. [PMID: 24733293 PMCID: PMC3986400 DOI: 10.1371/journal.pone.0094996] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Accepted: 03/21/2014] [Indexed: 12/14/2022] Open
Abstract
Previous studies have shown that whole body deletion of the glucagon receptor suppresses the ability of starvation to increase hepatic fibroblast growth factor 21 (FGF21) expression and plasma FGF21 concentration. Here, we investigate the mechanism by which glucagon receptor activation increases hepatic FGF21 production. Incubating primary rat hepatocyte cultures with glucagon, dibutyryl cAMP or forskolin stimulated a 3-4-fold increase in FGF21 secretion. The effect of these agents on FGF21 secretion was not associated with an increase in FGF21 mRNA abundance. Glucagon induction of FGF21 secretion was additive with the stimulatory effect of a PPARα activator (GW7647) on FGF21 secretion. Inhibition of protein kinase A (PKA) and downstream components of the PKA pathway [i.e. AMP-activated protein kinase and p38 MAPK] suppressed glucagon activation of FGF21 secretion. Incubating hepatocytes with an exchange protein directly activated by cAMP (EPAC)-selective cAMP analog [i.e. 8-(4-chlorophenylthio)-2'-O-methyladenosine-3', 5'-cyclic monophosphate (cpTOME)], stimulated a 3.9-fold increase FGF21 secretion, whereas inhibition of the EPAC effector, Rap1, suppressed glucagon activation of FGF21 secretion. Treatment of hepatocytes with insulin also increased FGF21 secretion. In contrast to glucagon, insulin activation of FGF21 secretion was associated with an increase in FGF21 mRNA abundance. Glucagon synergistically interacted with insulin to stimulate a further increase in FGF21 secretion and FGF21 mRNA abundance. These results demonstrate that glucagon increases hepatic FGF21 secretion via a posttranscriptional mechanism and provide evidence that both the PKA branch and EPAC branch of the cAMP pathway play a role in mediating this effect. These results also identify a novel synergistic interaction between glucagon and insulin in the regulation of FGF21 secretion and FGF21 mRNA abundance. We propose that this insulin/glucagon synergism plays a role in mediating the elevation in FGF21 production during starvation and conditions related to metabolic syndrome.
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Affiliation(s)
- Holly A Cyphert
- Department of Biochemistry, West Virginia University, Morgantown, West Virginia, United States of America
| | - Kimberly M Alonge
- Department of Biochemistry, West Virginia University, Morgantown, West Virginia, United States of America
| | - Siri M Ippagunta
- Department of Biochemistry, West Virginia University, Morgantown, West Virginia, United States of America
| | - F Bradley Hillgartner
- Department of Biochemistry, West Virginia University, Morgantown, West Virginia, United States of America
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238
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Hall JA, Tabata M, Rodgers JT, Puigserver P. USP7 attenuates hepatic gluconeogenesis through modulation of FoxO1 gene promoter occupancy. Mol Endocrinol 2014; 28:912-24. [PMID: 24694308 DOI: 10.1210/me.2013-1420] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Hepatic forkhead protein FoxO1 is a key component of systemic glucose homeostasis via its ability to regulate the transcription of rate-limiting enzymes in gluconeogenesis. Important in the regulation of FoxO1 transcriptional activity are the modifying/demodifying enzymes that lead to posttranslational modification. Here, we demonstrate the functional interaction and regulation of FoxO1 by herpesvirus-associated ubiquitin-specific protease 7 (USP7; also known as herpesvirus-associated ubiquitin-specific protease, HAUSP), a deubiquitinating enzyme. We show that USP7-mediated mono-deubiquitination of FoxO1 results in suppression of FoxO1 transcriptional activity through decreased FoxO1 occupancy on the promoters of gluconeogenic genes. Knockdown of USP7 in primary hepatocytes leads to increased expression of FoxO1-target gluconeogenic genes and elevated glucose production. Consistent with this, USP7 gain-of-function suppresses the fasting/cAMP-induced activation of gluconeogenic genes in hepatocyte cells and in mouse liver, resulting in decreased hepatic glucose production. Notably, we show that the effects of USP7 on hepatic glucose metabolism depend on FoxO1. Together, these results place FoxO1 under the intimate regulation of deubiquitination and glucose metabolic control with important implication in diseases such as diabetes.
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Affiliation(s)
- Jessica A Hall
- Departments of Cancer Biology, Dana-Farber Cancer Institute and Cell Biology, Harvard Medical School, Boston, Massachusetts 02115
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239
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Abstract
The prevalence of Type 2 diabetes mellitus is predicted to increase dramatically over the coming years and the clinical implications and healthcare costs from this disease are overwhelming. In many cases, this pathological condition is linked to a cluster of metabolic disorders, such as obesity, systemic hypertension and dyslipidaemia, defined as the metabolic syndrome. Insulin resistance has been proposed as the key mediator of all of these features and contributes to the associated high cardiovascular morbidity and mortality. Although the molecular mechanisms behind insulin resistance are not completely understood, a negative cross-talk between AngII (angiotensin II) and the insulin signalling pathway has been the focus of great interest in the last decade. Indeed, substantial evidence has shown that anti-hypertensive drugs that block the RAS (renin-angiotensin system) may also act to prevent diabetes. Despite its long history, new components within the RAS continue to be discovered. Among them, Ang-(1-7) [angiotensin-(1-7)] has gained special attention as a counter-regulatory hormone opposing many of the AngII-related deleterious effects. Specifically, we and others have demonstrated that Ang-(1-7) improves the action of insulin and opposes the negative effect that AngII exerts at this level. In the present review, we provide evidence showing that insulin and Ang-(1-7) share a common intracellular signalling pathway. We also address the molecular mechanisms behind the beneficial effects of Ang-(1-7) on AngII-mediated insulin resistance. Finally, we discuss potential therapeutic approaches leading to modulation of the ACE2 (angiotensin-converting enzyme 2)/Ang-(1-7)/Mas receptor axis as a very attractive strategy in the therapy of the metabolic syndrome and diabetes-associated diseases.
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240
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Insulin, IGF-1 and GLP-1 signaling in neurodegenerative disorders: targets for disease modification? Prog Neurobiol 2014; 118:1-18. [PMID: 24582776 DOI: 10.1016/j.pneurobio.2014.02.005] [Citation(s) in RCA: 171] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Revised: 02/09/2014] [Accepted: 02/20/2014] [Indexed: 12/13/2022]
Abstract
Insulin and Insulin Growth Factor-1 (IGF-1) play a major role in body homeostasis and glucose regulation. They also have paracrine/autocrine functions in the brain. The Insulin/IGF-1 signaling pathway contributes to the control of neuronal excitability, nerve cell metabolism and cell survival. Glucagon like peptide-1 (GLP-1), known as an insulinotropic hormone has similar functions and growth like properties as insulin/IGF-1. Growing evidence suggests that dysfunction of these pathways contribute to the progressive loss of neurons in Alzheimer's disease (AD) and Parkinson's disease (PD), the two most frequent neurodegenerative disorders. These findings have led to numerous studies in preclinical models of neurodegenerative disorders targeting insulin/IGF-1 and GLP-1 signaling with currently available anti-diabetics. These studies have shown that administration of insulin, IGF-1 and GLP-1 agonists reverses signaling abnormalities and has positive effects on surrogate markers of neurodegeneration and behavioral outcomes. Several proof-of-concept studies are underway that attempt to translate the encouraging preclinical results to patients suffering from AD and PD. In the first part of this review, we discuss physiological functions of insulin/IGF-1 and GLP-1 signaling pathways including downstream targets and receptors distribution within the brain. In the second part, we undertake a comprehensive overview of preclinical studies targeting insulin/IGF-1 or GLP-1 signaling for treating AD and PD. We then detail the design of clinical trials that have used anti-diabetics for treating AD and PD patients. We close with future considerations that treat relevant issues for successful translation of these encouraging preclinical results into treatments for patients with AD and PD.
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241
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Miao J, Haas JT, Manthena P, Wang Y, Zhao E, Vaitheesvaran B, Kurland IJ, Biddinger SB. Hepatic insulin receptor deficiency impairs the SREBP-2 response to feeding and statins. J Lipid Res 2014; 55:659-67. [PMID: 24516236 DOI: 10.1194/jlr.m043711] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The liver plays a central role in metabolism and mediating insulin action. To dissect the effects of insulin on the liver in vivo, we have studied liver insulin receptor knockout (LIRKO) mice. Because LIRKO livers lack insulin receptors, they are unable to respond to insulin. Surprisingly, the most profound derangement observed in LIRKO livers by microarray analysis is a suppression of the cholesterologenic genes. Sterol regulatory element binding protein (SREBP)-2 promotes cholesterologenic gene transcription, and is inhibited by intracellular cholesterol. LIRKO livers show a slight increase in hepatic cholesterol, a 40% decrease in Srebp-2, and a 50-90% decrease in the cholesterologenic genes at the mRNA and protein levels. In control mice, SREBP-2 and cholesterologenic gene expression are suppressed by fasting and restored by refeeding; in LIRKO mice, this response is abolished. Similarly, the ability of statins to induce Srebp-2 and the cholesterologenic genes is lost in LIRKO livers. In contrast, ezetimibe treatment robustly induces Srepb-2 and its targets in LIRKO livers, raising the possibility that insulin may regulate SREBP-2 indirectly, by altering the accumulation or distribution of cholesterol within the hepatocyte. Taken together, these data indicate that cholesterol synthesis is a key target of insulin action in the liver.
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Affiliation(s)
- Ji Miao
- Division of Endocrinology, Boston Children's Hospital, Harvard Medical School, Boston MA
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242
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Guo S. Insulin signaling, resistance, and the metabolic syndrome: insights from mouse models into disease mechanisms. J Endocrinol 2014; 220:T1-T23. [PMID: 24281010 PMCID: PMC4087161 DOI: 10.1530/joe-13-0327] [Citation(s) in RCA: 326] [Impact Index Per Article: 32.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Insulin resistance is a major underlying mechanism responsible for the 'metabolic syndrome', which is also known as insulin resistance syndrome. The incidence of the metabolic syndrome is increasing at an alarming rate, becoming a major public and clinical problem worldwide. The metabolic syndrome is represented by a group of interrelated disorders, including obesity, hyperglycemia, hyperlipidemia, and hypertension. It is also a significant risk factor for cardiovascular disease and increased morbidity and mortality. Animal studies have demonstrated that insulin and its signaling cascade normally control cell growth, metabolism, and survival through the activation of MAPKs and activation of phosphatidylinositide-3-kinase (PI3K), in which the activation of PI3K associated with insulin receptor substrate 1 (IRS1) and IRS2 and subsequent Akt→Foxo1 phosphorylation cascade has a central role in the control of nutrient homeostasis and organ survival. The inactivation of Akt and activation of Foxo1, through the suppression IRS1 and IRS2 in different organs following hyperinsulinemia, metabolic inflammation, and overnutrition, may act as the underlying mechanisms for the metabolic syndrome in humans. Targeting the IRS→Akt→Foxo1 signaling cascade will probably provide a strategy for therapeutic intervention in the treatment of type 2 diabetes and its complications. This review discusses the basis of insulin signaling, insulin resistance in different mouse models, and how a deficiency of insulin signaling components in different organs contributes to the features of the metabolic syndrome. Emphasis is placed on the role of IRS1, IRS2, and associated signaling pathways that are coupled to Akt and the forkhead/winged helix transcription factor Foxo1.
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Affiliation(s)
- Shaodong Guo
- Division of Molecular Cardiology, Department of Medicine, College of Medicine, Texas A&M University Health Science Center, Scott & White, Central Texas Veterans Health Care System, 1901 South 1st Street, Bldg. 205, Temple, Texas 76504, USA
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243
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Herrema H, Lee J, Zhou Y, Copps KD, White MF, Ozcan U. IRS1Ser³⁰⁷ phosphorylation does not mediate mTORC1-induced insulin resistance. Biochem Biophys Res Commun 2013; 443:689-93. [PMID: 24333417 DOI: 10.1016/j.bbrc.2013.12.023] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Accepted: 12/04/2013] [Indexed: 12/12/2022]
Abstract
Increased mammalian target of rapamycin complex 1 (mTORC1) activity has been suggested to play important roles in development of insulin resistance in obesity. mTORC1 hyperactivity also increases endoplasmic reticulum (ER) stress, which in turn contributes to development of insulin resistance and glucose intolerance. Increased IRS1 phosphorylation at Ser307 in vitro is correlated with mTORC1- and ER stress-induced insulin resistance. This phosphorylation site correlates strongly with impaired insulin receptor signaling in diabetic mice and humans. In contrast, evidence from knock-in mice suggests that phosphorylation of IRS1 at Ser307 is actually required to maintain insulin sensitivity. To study the involvement of IRS1(Ser307) phosphorylation in mTORC1-mediated glucose intolerance and insulin sensitivity in vivo, we investigated the effects of liver specific TSC1 depletion in IRS1(Ser307Ala) mice and controls. Our results demonstrate that blockade of IRS1(Ser307) phosphorylation in vivo does not prevent mTORC1-mediated glucose intolerance and insulin resistance.
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Affiliation(s)
- Hilde Herrema
- Division of Endocrinology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Jaemin Lee
- Division of Endocrinology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Yingjiang Zhou
- Division of Endocrinology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Kyle D Copps
- Division of Endocrinology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Morris F White
- Division of Endocrinology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Umut Ozcan
- Division of Endocrinology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA.
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244
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Liu X, Cui Y, Li M, Xu H, Zuo J, Fang F, Chang Y. Cobalt protoporphyrin induces HO-1 expression mediated partially by FOXO1 and reduces mitochondria-derived reactive oxygen species production. PLoS One 2013; 8:e80521. [PMID: 24255720 PMCID: PMC3821864 DOI: 10.1371/journal.pone.0080521] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Accepted: 10/14/2013] [Indexed: 12/23/2022] Open
Abstract
Background Reactive oxygen species arise in the mitochondria as byproducts of respiration and oxidase activity and have important roles in many physiological and pathophysiological conditions. The level of reactive oxygen species is regulated by a number of enzymes and physiological antioxidants, including HO-1, Sod2, catalase and COX-2, etc. And HO-1 against oxidative stress requires an increase in stress-responsive genes, such as Sod2 and catalase. Especially for the activity of HO-1, cobalt protoporphyrin is known to be a potent and effective inducer in many tissues. The transcription factor, FOXO1 is resistant to oxidative stress through downregulating reactive oxygen species production. Previous study showed that FOXO1 induces HO-1 expression by binding to HO-1 promoter. The question whether cobalt protoporphyrin induces HO-1 expression mediated by FOXO1 and subsequently lessens reactive oxygen species production remains to be elucidated. Results Cobalt protoporphyrin enhances the expression of FOXO1 and facilitates FOXO1 binding to HO-1 promoter and increasing its transcriptional activity without influencing the FOXO1 protein stability. CoPP induces HO-1 and other oxidative stress-responsive genes expression, such as catalase, cytochrome c, Sod2, and COX-2, and decreases mitochondria-derived reactive oxygen species production, which are mediated partially by FOXO1. Conclusions Cobalt protoporphyrin induces HO-1 and other oxidative stress-responsive genes expression mediated partially by FOXO1, and has an important role in reducing cellular reactive oxygen species level. Cobalt protoporphyrin may be a more promising therapeutic agent to upregulate some antioxidantive genes.
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Affiliation(s)
- Xiaojun Liu
- The National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- * E-mail: (XL); (FF); (YC)
| | - Ying Cui
- The National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Meixia Li
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Haifeng Xu
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Interventional Therapy, Peking University Cancer Hospital & Institute, Beijing, China
| | - Jin Zuo
- The National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Fude Fang
- The National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- * E-mail: (XL); (FF); (YC)
| | - Yongsheng Chang
- The National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- * E-mail: (XL); (FF); (YC)
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245
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Riehle C, Wende AR, Sena S, Pires KM, Pereira RO, Zhu Y, Bugger H, Frank D, Bevins J, Chen D, Perry CN, Dong XC, Valdez S, Rech M, Sheng X, Weimer BC, Gottlieb RA, White MF, Abel ED. Insulin receptor substrate signaling suppresses neonatal autophagy in the heart. J Clin Invest 2013; 123:5319-33. [PMID: 24177427 DOI: 10.1172/jci71171] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Accepted: 08/29/2013] [Indexed: 01/12/2023] Open
Abstract
The induction of autophagy in the mammalian heart during the perinatal period is an essential adaptation required to survive early neonatal starvation; however, the mechanisms that mediate autophagy suppression once feeding is established are not known. Insulin signaling in the heart is transduced via insulin and IGF-1 receptors (IGF-1Rs). We disrupted insulin and IGF-1R signaling by generating mice with combined cardiomyocyte-specific deletion of Irs1 and Irs2. Here we show that loss of IRS signaling prevented the physiological suppression of autophagy that normally parallels the postnatal increase in circulating insulin. This resulted in unrestrained autophagy in cardiomyocytes, which contributed to myocyte loss, heart failure, and premature death. This process was ameliorated either by activation of mTOR with aa supplementation or by genetic suppression of autophagic activation. Loss of IRS1 and IRS2 signaling also increased apoptosis and precipitated mitochondrial dysfunction, which were not reduced when autophagic flux was normalized. Together, these data indicate that in addition to prosurvival signaling, insulin action in early life mediates the physiological postnatal suppression of autophagy, thereby linking nutrient sensing to postnatal cardiac development.
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246
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Qi Y, Xu Z, Zhu Q, Thomas C, Kumar R, Feng H, Dostal DE, White MF, Baker KM, Guo S. Myocardial loss of IRS1 and IRS2 causes heart failure and is controlled by p38α MAPK during insulin resistance. Diabetes 2013; 62:3887-900. [PMID: 24159000 PMCID: PMC3806607 DOI: 10.2337/db13-0095] [Citation(s) in RCA: 127] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cardiac failure is a major cause of death in patients with type 2 diabetes, but the molecular mechanism that links diabetes to heart failure remains unclear. Insulin resistance is a hallmark of type 2 diabetes, and insulin receptor substrates 1 and 2 (IRS1 and IRS2) are the major insulin-signaling components regulating cellular metabolism and survival. To determine the role of IRS1 and IRS2 in the heart and examine whether hyperinsulinemia causes myocardial insulin resistance and cellular dysfunction via IRS1 and IRS2, we generated heart-specific IRS1 and IRS2 gene double-knockout (H-DKO) mice and liver-specific IRS1 and IRS2 double-knockout (L-DKO) mice. H-DKO mice had reduced ventricular mass; developed cardiac apoptosis, fibrosis, and failure; and showed diminished Akt→forkhead box class O-1 signaling that was accompanied by impaired cardiac metabolic gene expression and reduced ATP content. L-DKO mice had decreased cardiac IRS1 and IRS2 proteins and exhibited features of heart failure, with impaired cardiac energy metabolism gene expression and activation of p38α mitogen-activated protein kinase (p38). Using neonatal rat ventricular cardiomyocytes, we further found that chronic insulin exposure reduced IRS1 and IRS2 proteins and prevented insulin action through activation of p38, revealing a fundamental mechanism of cardiac dysfunction during insulin resistance and type 2 diabetes.
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Affiliation(s)
- Yajuan Qi
- Division of Molecular Cardiology, Department of Medicine, College of Medicine, Texas A&M University Health Science Center, and Scott & White, Central Texas Veterans Health Care System, Temple, Texas
- Department of Pharmacology, Hebei United University, Tangshan, China
| | - Zihui Xu
- Division of Molecular Cardiology, Department of Medicine, College of Medicine, Texas A&M University Health Science Center, and Scott & White, Central Texas Veterans Health Care System, Temple, Texas
- Division of Endocrinology, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Qinglei Zhu
- Division of Molecular Cardiology, Department of Medicine, College of Medicine, Texas A&M University Health Science Center, and Scott & White, Central Texas Veterans Health Care System, Temple, Texas
| | - Candice Thomas
- Division of Molecular Cardiology, Department of Medicine, College of Medicine, Texas A&M University Health Science Center, and Scott & White, Central Texas Veterans Health Care System, Temple, Texas
| | - Rajesh Kumar
- Division of Molecular Cardiology, Department of Medicine, College of Medicine, Texas A&M University Health Science Center, and Scott & White, Central Texas Veterans Health Care System, Temple, Texas
| | - Hao Feng
- Division of Molecular Cardiology, Department of Medicine, College of Medicine, Texas A&M University Health Science Center, and Scott & White, Central Texas Veterans Health Care System, Temple, Texas
| | - David E. Dostal
- Division of Molecular Cardiology, Department of Medicine, College of Medicine, Texas A&M University Health Science Center, and Scott & White, Central Texas Veterans Health Care System, Temple, Texas
| | - Morris F. White
- Howard Hughes Medical Institute, Division of Endocrinology, Children’s Hospital Boston, Harvard Medical School, Boston, Massachusetts
| | - Kenneth M. Baker
- Division of Molecular Cardiology, Department of Medicine, College of Medicine, Texas A&M University Health Science Center, and Scott & White, Central Texas Veterans Health Care System, Temple, Texas
| | - Shaodong Guo
- Division of Molecular Cardiology, Department of Medicine, College of Medicine, Texas A&M University Health Science Center, and Scott & White, Central Texas Veterans Health Care System, Temple, Texas
- Corresponding author: Shaodong Guo,
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247
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Irs2 and Irs4 synergize in non-LepRb neurons to control energy balance and glucose homeostasis. Mol Metab 2013; 3:55-63. [PMID: 24567904 PMCID: PMC3929908 DOI: 10.1016/j.molmet.2013.10.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Revised: 10/16/2013] [Accepted: 10/18/2013] [Indexed: 01/03/2023] Open
Abstract
Insulin receptor substrates (Irs1, 2, 3 and Irs4) mediate the actions of insulin/IGF1 signaling. They have similar structure, but distinctly regulate development, growth, and metabolic homeostasis. Irs2 contributes to central metabolic sensing, partially by acting in leptin receptor (LepRb)-expressing neurons. Although Irs4 is largely restricted to the hypothalamus, its contribution to metabolic regulation is unclear because Irs4-null mice barely distinguishable from controls. We postulated that Irs2 and Irs4 synergize and complement each other in the brain. To examine this possibility, we investigated the metabolism of whole body Irs4−/y mice that lacked Irs2 in the CNS (bIrs2−/−·Irs4−/y) or only in LepRb-neurons (Lepr∆Irs2·Irs4−/y). bIrs2−/−·Irs4−/y mice developed severe obesity and decreased energy expenditure, along with hyperglycemia and insulin resistance. Unexpectedly, the body weight and fed blood glucose levels of Lepr∆Irs2·Irs4−/y mice were not different from Lepr∆Irs2 mice, suggesting that the functions of Irs2 and Irs4 converge upon neurons that are distinct from those expressing LepRb.
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Key Words
- ARC, arcuate nucleus of the hypothalamus
- CNS, central nervous system
- ERK, extracellular signal-regulated kinase
- Energy balance
- Insulin receptor substrate 2
- Insulin receptor substrate 4
- Irs2, insulin receptor substrate 2
- Irs4, insulin receptor substrate 4
- LepRb, leptin receptor
- Leptin
- Nutrient homeostasis
- Obesity
- PI3K, phosphatidylinositol 3-kinase
- POMC, proopiomelanocortin
- Socs3, suppressor of cytokine signaling-3
- Stat3, signal transducer and activator of transcription 3
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Turnbull J, Tiberia E, Pereira S, Zhao X, Pencea N, Wheeler AL, Yu WQ, Ivovic A, Naranian T, Israelian N, Draginov A, Piliguian M, Frankland PW, Wang P, Ackerley CA, Giacca A, Minassian BA. Deficiency of a glycogen synthase-associated protein, Epm2aip1, causes decreased glycogen synthesis and hepatic insulin resistance. J Biol Chem 2013; 288:34627-37. [PMID: 24142699 DOI: 10.1074/jbc.m113.483198] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Glycogen synthesis is a major component of the insulin response, and defective glycogen synthesis is a major portion of insulin resistance. Insulin regulates glycogen synthase (GS) through incompletely defined pathways that activate the enzyme through dephosphorylation and, more potently, allosteric activation. We identify Epm2aip1 as a GS-associated protein. We show that the absence of Epm2aip1 in mice impairs allosteric activation of GS by glucose 6-phosphate, decreases hepatic glycogen synthesis, increases liver fat, causes hepatic insulin resistance, and protects against age-related obesity. Our work identifies a novel GS-associated GS activity-modulating component of insulin resistance.
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249
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Chen AT, Guo C, Dumas KJ, Ashrafi K, Hu PJ. Effects of Caenorhabditis elegans sgk-1 mutations on lifespan, stress resistance, and DAF-16/FoxO regulation. Aging Cell 2013; 12:932-40. [PMID: 23786484 PMCID: PMC3824081 DOI: 10.1111/acel.12120] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/12/2013] [Indexed: 02/03/2023] Open
Abstract
The AGC family serine–threonine kinases Akt and Sgk are similar in primary amino acid sequence and in vitro substrate specificity, and both kinases are thought to directly phosphorylate and inhibit FoxO transcription factors. In the nematode Caenorhabditis elegans, it is well established that AKT-1 controls dauer arrest and lifespan by regulating the subcellular localization of the FoxO transcription factor DAF-16. SGK-1 is thought to act similarly to AKT-1 in lifespan control by phosphorylating and inhibiting the nuclear translocation of DAF-16/FoxO. Using sgk-1 null and gain-of-function mutants, we now provide multiple lines of evidence indicating that AKT-1 and SGK-1 influence C. elegans lifespan, stress resistance, and DAF-16/FoxO activity in fundamentally different ways. Whereas AKT-1 shortens lifespan, SGK-1 promotes longevity in a DAF-16-/FoxO-dependent manner. In contrast to AKT-1, which reduces resistance to multiple stresses, SGK-1 promotes resistance to oxidative stress and ultraviolet radiation but inhibits thermotolerance. Analysis of several DAF-16/FoxO target genes that are repressed by AKT-1 reveals that SGK-1 represses a subset of these genes while having little influence on the expression of others. Accordingly, unlike AKT-1, which promotes the cytoplasmic sequestration of DAF-16/FoxO, SGK-1 does not influence DAF-16/FoxO subcellular localization. Thus, in spite of their similar in vitro substrate specificities, Akt and Sgk influence longevity, stress resistance, and FoxO activity through distinct mechanisms in vivo. Our findings highlight the need for a re-evaluation of current paradigms of FoxO regulation by Sgk.
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Affiliation(s)
| | - Chunfang Guo
- Life Sciences Institute University of Michigan Ann Arbor Michigan
| | | | - Kaveh Ashrafi
- Department of Physiology University of California San Francisco California
| | - Patrick J. Hu
- Life Sciences Institute University of Michigan Ann Arbor Michigan
- Departments of Internal Medicine and Cell and Developmental Biology University of Michigan Medical School Ann Arbor Michigan
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250
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Wei K, Piecewicz SM, McGinnis LM, Taniguchi CM, Wiegand SJ, Anderson K, Chan CWM, Mulligan KX, Kuo D, Yuan J, Vallon M, Morton L, Lefai E, Simon MC, Maher JJ, Mithieux G, Rajas F, Annes J, McGuinness OP, Thurston G, Giaccia AJ, Kuo CJ. A liver Hif-2α-Irs2 pathway sensitizes hepatic insulin signaling and is modulated by Vegf inhibition. Nat Med 2013; 19:1331-1337. [PMID: 24037094 PMCID: PMC3795838 DOI: 10.1038/nm.3295] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Accepted: 07/09/2013] [Indexed: 12/24/2022]
Abstract
Insulin initiates diverse hepatic metabolic responses, including gluconeogenic suppression and induction of glycogen synthesis and lipogenesis. The liver possesses a rich sinusoidal capillary network with a higher degree of hypoxia and lower gluconeogenesis in the perivenous zone as compared to the rest of the organ. Here, we show that diverse vascular endothelial growth factor (VEGF) inhibitors improved glucose tolerance in nondiabetic C57BL/6 and diabetic db/db mice, potentiating hepatic insulin signaling with lower gluconeogenic gene expression, higher glycogen storage and suppressed hepatic glucose production. VEGF inhibition induced hepatic hypoxia through sinusoidal vascular regression and sensitized liver insulin signaling through hypoxia-inducible factor-2α (Hif-2α, encoded by Epas1) stabilization. Notably, liver-specific constitutive activation of HIF-2α, but not HIF-1α, was sufficient to augment hepatic insulin signaling through direct and indirect induction of insulin receptor substrate-2 (Irs2), an essential insulin receptor adaptor protein. Further, liver Irs2 was both necessary and sufficient to mediate Hif-2α and Vegf inhibition effects on glucose tolerance and hepatic insulin signaling. These results demonstrate an unsuspected intersection between Hif-2α-mediated hypoxic signaling and hepatic insulin action through Irs2 induction, which can be co-opted by Vegf inhibitors to modulate glucose metabolism. These studies also indicate distinct roles in hepatic metabolism for Hif-1α, which promotes glycolysis, and Hif-2α, which suppresses gluconeogenesis, and suggest new treatment approaches for type 2 diabetes mellitus.
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Affiliation(s)
- Kevin Wei
- Division of Hematology, Stanford University School of Medicine, Stanford, California 94305, USA
| | - Stephanie M. Piecewicz
- Division of Hematology, Stanford University School of Medicine, Stanford, California 94305, USA
| | - Lisa M. McGinnis
- Division of Hematology, Stanford University School of Medicine, Stanford, California 94305, USA
| | - Cullen M. Taniguchi
- Division of Radiation Oncology Stanford University School of Medicine, Stanford, California 94305, USA
| | - Stanley J. Wiegand
- Regeneron Pharmaceuticals, Incorporated, Tarrytown, New York, 10591, USA
| | - Keith Anderson
- Regeneron Pharmaceuticals, Incorporated, Tarrytown, New York, 10591, USA
| | - Carol W-M. Chan
- Division of Hematology, Stanford University School of Medicine, Stanford, California 94305, USA
| | - Kimberly X. Mulligan
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville TN 37232, USA
| | - David Kuo
- Division of Hematology, Stanford University School of Medicine, Stanford, California 94305, USA
| | - Jenny Yuan
- Division of Hematology, Stanford University School of Medicine, Stanford, California 94305, USA
| | - Mario Vallon
- Division of Hematology, Stanford University School of Medicine, Stanford, California 94305, USA
| | - Lori Morton
- Regeneron Pharmaceuticals, Incorporated, Tarrytown, New York, 10591, USA
| | - Etienne Lefai
- INSERM U 1060, INRA 1235, Universite de Lyon, Faculté de Médecine Lyon Sud - BP12, 69921 OULLINS Cedex, France
| | - M. Celeste Simon
- Abramson Family Cancer Research Institute, Howard Hughes Medical Institute, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, 19104, USA
| | - Jacquelyn J. Maher
- UCSF Liver Center, San Francisco General Hospital, 1001 Potrero Ave. Building 40, Room 4102, San Francisco, CA 94110
| | - Gilles Mithieux
- Inserm U855/Université Lyon, Faculté Lyon Est Laennec, 7 rue Guillaume Paradin, 69372 Lyon cedex 08, France
| | - Fabienne Rajas
- Inserm U855/Université Lyon, Faculté Lyon Est Laennec, 7 rue Guillaume Paradin, 69372 Lyon cedex 08, France
| | - Justin Annes
- Division of Endocrinology and Metabolism, Stanford University School of Medicine, Stanford, California 94305, USA
| | - Owen P. McGuinness
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville TN 37232, USA
| | - Gavin Thurston
- Regeneron Pharmaceuticals, Incorporated, Tarrytown, New York, 10591, USA
| | - Amato J. Giaccia
- Division of Radiation Oncology Stanford University School of Medicine, Stanford, California 94305, USA
| | - Calvin J. Kuo
- Division of Hematology, Stanford University School of Medicine, Stanford, California 94305, USA
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