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Das GC, Hollinger FB. GSK-3β as a Potential Coordinator of Anabolic and Catabolic Pathways in Hepatitis C Virus Insulin Resistance. Intervirology 2023; 67:6-18. [PMID: 38104537 PMCID: PMC10794973 DOI: 10.1159/000535787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 12/11/2023] [Indexed: 12/19/2023] Open
Abstract
INTRODUCTION Chronic hepatitis C infection can result in insulin resistance (IR). We have previously shown that it occurs through the interaction of pathways for glucose homeostasis, insulin signaling, and autophagy. But it is not known how soon the pathways are activated and how IR is related to the signals generated by catabolic and anabolic conditions occurring in infected cells. We have extended our studies to a cell culture system mimicking acute infection and to downstream pathways involving energy-sensor AMPK and nutrient-sensor mTOR that are active in catabolic and anabolic processes within the infected cells. METHODS Huh7 liver cells in culture were infected with hepatitis C virus (HCV). We performed proteomics analysis of key proteins in infected cells by Western blotting and IP experiments, with or without IFNα exposure as a component of conventional therapeutic strategy. RESULTS We present evidence that (a) IRS-1 Ser312, Beclin-1, protein conjugate Atg12-Atg5 or GS Ser641 are up-regulated early in infection presumably by activating the same pathways as utilized for persistent infection; (b) Bcl-XL, an inhibitor of both autophagy and apoptosis, is present in a core complex with IRS-1 Ser312 and Beclin-1 during progression of IR; (c) AMPK level remains about the same in infected cells where it is activated by phosphorylation at Thr172 concomitant with increased autophagy, a hallmark of catabolic conditions; (d) an mTOR level that promotes anabolism is increased rather than decreased under an expanded autophagy; (e) hypophosphorylation of translational repressor 4E-BP1 downstream of mTOR is suggestive of reduced protein synthesis; and (f) β-catenin, is up-regulated but not phosphorylated suggesting indirectly our previous contention that its kinase, GSK-3β, is mostly in an inactive state. CONCLUSION We report that in the development of IR following chronic infection, anabolic and catabolic pathways are activated early, and the metabolic interaction occurs possibly in a core complex with IRS-1 Ser312, Beclin-1, and autophagy inhibitor Bcl-XL. Induction of autophagy is usually controlled by a two-edged mechanism acting in opposition under anabolic and catabolic conditions by AMPK/mTOR/4E-BP1 pathway with GSK-3β-mediated feedback loops. However, we have observed an up-regulation of mTOR along with an up-regulation of AMPK caused by HCV infection is a deviation from the normal scenario described above which might be of therapeutic interest.
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Affiliation(s)
- Gokul C Das
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, USA
| | - F Blaine Hollinger
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, USA
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2
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Nguyen MT, Min KH, Lee W. MiR-183-5p Induced by Saturated Fatty Acids Hinders Insulin Signaling by Downregulating IRS-1 in Hepatocytes. Int J Mol Sci 2022; 23:ijms23062979. [PMID: 35328400 PMCID: PMC8953084 DOI: 10.3390/ijms23062979] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 03/07/2022] [Accepted: 03/09/2022] [Indexed: 02/06/2023] Open
Abstract
Excessive saturated fatty acids (SFA) uptake is known to be a primary cause of obesity, a widely acknowledged risk factor of insulin resistance and type 2 diabetes. Although specific microRNAs (miRNAs) targeting insulin signaling intermediates are dysregulated by SFA, their effects on insulin signaling and sensitivity are largely unknown. Here, we investigated the role of SFA-induced miR-183-5p in the regulation of proximal insulin signaling molecules and the development of hepatic insulin resistance. HepG2 hepatocytes treated with palmitate and the livers of high-fat diet (HFD)-fed mice exhibited impaired insulin signaling resulting from dramatic reductions in the protein expressions of insulin receptor (INSR) and insulin receptor substrate-1 (IRS-1). Differential expression analysis showed the level of miR-183-5p, which tentatively targets the 3'UTR of IRS-1, was significantly elevated in palmitate-treated HepG2 hepatocytes and the livers of HFD-fed mice. Dual-luciferase analysis showed miR-183-5p bound directly to the 3'UTR of IRS-1 and reduced IRS-1 expression at the post-transcriptional stage. Moreover, transfection of HepG2 hepatocytes with miR-183-5p mimic significantly inhibited IRS-1 expression and hindered insulin signaling, consequently inhibiting insulin-stimulated glycogen synthesis. Collectively, this study reveals a novel mechanism whereby miR-183-5p induction by SFA impairs insulin signaling and suggests miR-183-5p plays a crucial role in the pathogenesis of hepatic insulin resistance in the background of obesity.
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Affiliation(s)
- Mai Thi Nguyen
- Department of Biochemistry, College of Medicine, Dongguk University, 123 Dongdae-ro, Gyeongju 38066, Korea; (M.T.N.); (K.-H.M.)
| | - Kyung-Ho Min
- Department of Biochemistry, College of Medicine, Dongguk University, 123 Dongdae-ro, Gyeongju 38066, Korea; (M.T.N.); (K.-H.M.)
| | - Wan Lee
- Department of Biochemistry, College of Medicine, Dongguk University, 123 Dongdae-ro, Gyeongju 38066, Korea; (M.T.N.); (K.-H.M.)
- Channelopathy Research Center, College of Medicine, Dongguk University, 32 Dongguk-ro, Ilsan Dong-gu, Goyang 10326, Korea
- Correspondence: ; Tel.: +82-54-770-2409
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3
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Roles of Cullin-RING Ubiquitin Ligases in Cardiovascular Diseases. Biomolecules 2022; 12:biom12030416. [PMID: 35327608 PMCID: PMC8946067 DOI: 10.3390/biom12030416] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 03/03/2022] [Accepted: 03/04/2022] [Indexed: 12/18/2022] Open
Abstract
Maintenance of protein homeostasis is crucial for virtually every aspect of eukaryotic biology. The ubiquitin-proteasome system (UPS) represents a highly regulated quality control machinery that protects cells from a variety of stress conditions as well as toxic proteins. A large body of evidence has shown that UPS dysfunction contributes to the pathogenesis of cardiovascular diseases. This review highlights the latest findings regarding the physiological and pathological roles of cullin-RING ubiquitin ligases (CRLs), an essential player in the UPS, in the cardiovascular system. To inspire potential therapeutic invention, factors regulating CRL activities are also discussed.
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4
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Confettura AD, Cuboni E, Ammar MR, Jia S, Gomes GM, Yuanxiang P, Raman R, Li T, Grochowska KM, Ahrends R, Karpova A, Dityatev A, Kreutz MR. Neddylation-dependent protein degradation is a nexus between synaptic insulin resistance, neuroinflammation and Alzheimer's disease. Transl Neurodegener 2022; 11:2. [PMID: 34986876 PMCID: PMC8734066 DOI: 10.1186/s40035-021-00277-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 12/24/2021] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND The metabolic syndrome is a consequence of modern lifestyle that causes synaptic insulin resistance and cognitive deficits and that in interaction with a high amyloid load is an important risk factor for Alzheimer's disease. It has been proposed that neuroinflammation might be an intervening variable, but the underlying mechanisms are currently unknown. METHODS We utilized primary neurons to induce synaptic insulin resistance as well as a mouse model of high-risk aging that includes a high amyloid load, neuroinflammation, and diet-induced obesity to test hypotheses on underlying mechanisms. RESULTS We found that neddylation and subsequent activation of cullin-RING ligase complexes induced synaptic insulin resistance through ubiquitylation and degradation of the insulin-receptor substrate IRS1 that organizes synaptic insulin signaling. Accordingly, inhibition of neddylation preserved synaptic insulin signaling and rescued memory deficits in mice with a high amyloid load, which were fed with a 'western diet'. CONCLUSIONS Collectively, the data suggest that neddylation and degradation of the insulin-receptor substrate is a nodal point that links high amyloid load, neuroinflammation, and synaptic insulin resistance to cognitive decline and impaired synaptic plasticity in high-risk aging.
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Affiliation(s)
| | - Eleonora Cuboni
- RG Neuroplasticity, Leibniz-Institute for Neurobiology, 39118, Magdeburg, Germany
| | - Mohamed Rafeet Ammar
- RG Neuroplasticity, Leibniz-Institute for Neurobiology, 39118, Magdeburg, Germany
| | - Shaobo Jia
- German Center for Neurodegenerative Diseases (DZNE), 39120, Magdeburg, Germany
| | - Guilherme M Gomes
- RG Neuroplasticity, Leibniz-Institute for Neurobiology, 39118, Magdeburg, Germany.,Center for Behavioral Brain Sciences, Otto Von Guericke University, 39120, Magdeburg, Germany
| | - PingAn Yuanxiang
- RG Neuroplasticity, Leibniz-Institute for Neurobiology, 39118, Magdeburg, Germany
| | - Rajeev Raman
- RG Neuroplasticity, Leibniz-Institute for Neurobiology, 39118, Magdeburg, Germany
| | - Tingting Li
- Leibniz-Institut Für Analytische Wissenschaften-ISAS-e.V., 44227, Dortmund, Germany
| | - Katarzyna M Grochowska
- RG Neuroplasticity, Leibniz-Institute for Neurobiology, 39118, Magdeburg, Germany.,Leibniz Group 'Dendritic Organelles and Synaptic Function', Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, 20251, Hamburg, Germany
| | - Robert Ahrends
- Leibniz-Institut Für Analytische Wissenschaften-ISAS-e.V., 44227, Dortmund, Germany.,Department of Analytical Chemistry, Faculty of Chemistry, University of Vienna, 1090, Wien, Austria
| | - Anna Karpova
- RG Neuroplasticity, Leibniz-Institute for Neurobiology, 39118, Magdeburg, Germany.,Center for Behavioral Brain Sciences, Otto Von Guericke University, 39120, Magdeburg, Germany
| | - Alexander Dityatev
- German Center for Neurodegenerative Diseases (DZNE), 39120, Magdeburg, Germany.,Center for Behavioral Brain Sciences, Otto Von Guericke University, 39120, Magdeburg, Germany.,Medical Faculty, Otto-von-Guericke University, 39120, Magdeburg, Germany
| | - Michael R Kreutz
- RG Neuroplasticity, Leibniz-Institute for Neurobiology, 39118, Magdeburg, Germany. .,German Center for Neurodegenerative Diseases (DZNE), 39120, Magdeburg, Germany. .,Center for Behavioral Brain Sciences, Otto Von Guericke University, 39120, Magdeburg, Germany. .,Leibniz Group 'Dendritic Organelles and Synaptic Function', Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, 20251, Hamburg, Germany.
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5
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White MF, Kahn CR. Insulin action at a molecular level - 100 years of progress. Mol Metab 2021; 52:101304. [PMID: 34274528 PMCID: PMC8551477 DOI: 10.1016/j.molmet.2021.101304] [Citation(s) in RCA: 94] [Impact Index Per Article: 31.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 07/07/2021] [Accepted: 07/13/2021] [Indexed: 12/15/2022] Open
Abstract
The discovery of insulin 100 years ago and its application to the treatment of human disease in the years since have marked a major turning point in the history of medicine. The availability of purified insulin allowed for the establishment of its physiological role in the regulation of blood glucose and ketones, the determination of its amino acid sequence, and the solving of its structure. Over the last 50 years, the function of insulin has been applied into the discovery of the insulin receptor and its signaling cascade to reveal the role of impaired insulin signaling-or resistance-in the progression of type 2 diabetes. It has also become clear that insulin signaling can impact not only classical insulin-sensitive tissues, but all tissues of the body, and that in many of these tissues the insulin signaling cascade regulates unexpected physiological functions. Despite these remarkable advances, much remains to be learned about both insulin signaling and how to use this molecular knowledge to advance the treatment of type 2 diabetes and other insulin-resistant states.
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Affiliation(s)
- Morris F White
- Boston Children's Hospital and Harvard Medical School, Boston, MA, 02215, USA.
| | - C Ronald Kahn
- Joslin Diabetes Center, Harvard Medical School, Boston, MA, 02215, USA.
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6
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Anger M, Scheufele F, Ramanujam D, Meyer K, Nakajima H, Field LJ, Engelhardt S, Sarikas A. Genetic ablation of Cullin-RING E3 ubiquitin ligase 7 restrains pressure overload-induced myocardial fibrosis. PLoS One 2020; 15:e0244096. [PMID: 33351822 PMCID: PMC7755222 DOI: 10.1371/journal.pone.0244096] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 12/03/2020] [Indexed: 11/20/2022] Open
Abstract
Fibrosis is a pathognomonic feature of structural heart disease and counteracted by distinct cardioprotective mechanisms, e.g. activation of the phosphoinositide 3-kinase (PI3K) / AKT pro-survival pathway. The Cullin-RING E3 ubiquitin ligase 7 (CRL7) was identified as negative regulator of PI3K/AKT signalling in skeletal muscle, but its role in the heart remains to be elucidated. Here, we sought to determine whether CRL7 modulates to cardiac fibrosis following pressure overload and dissect its underlying mechanisms. For inactivation of CRL7, the Cullin 7 (Cul7) gene was deleted in cardiac myocytes (CM) by injection of adeno-associated virus subtype 9 (AAV9) vectors encoding codon improved Cre-recombinase (AAV9-CMV-iCre) in Cul7flox/flox mice. In addition, Myosin Heavy Chain 6 (Myh6; alpha-MHC)-MerCreMer transgenic mice with tamoxifen-induced CM-specific expression of iCre were used as alternate model. After transverse aortic constriction (TAC), causing chronic pressure overload and fibrosis, AAV9-CMV-iCre induced Cul7-/- mice displayed a ~50% reduction of interstitial cardiac fibrosis when compared to Cul7+/+ animals (6.7% vs. 3.4%, p<0.01). Similar results were obtained with Cul7flox/floxMyh6-Mer-Cre-MerTg(1/0) mice which displayed a ~30% reduction of cardiac fibrosis after TAC when compared to Cul7+/+Myh6-Mer-Cre-MerTg(1/0) controls after TAC surgery (12.4% vs. 8.7%, p<0.05). No hemodynamic alterations were observed. AKTSer473 phosphorylation was increased 3-fold (p<0.01) in Cul7-/- vs. control mice, together with a ~78% (p<0.001) reduction of TUNEL-positive apoptotic cells three weeks after TAC. In addition, CM-specific expression of a dominant-negative CUL71152stop mutant resulted in a 16.3-fold decrease (p<0.001) of in situ end-labelling (ISEL) positive apoptotic cells. Collectively, our data demonstrate that CM-specific ablation of Cul7 restrains myocardial fibrosis and apoptosis upon pressure overload, and introduce CRL7 as a potential target for anti-fibrotic therapeutic strategies of the heart.
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Affiliation(s)
- Melanie Anger
- Institute of Pharmacology and Toxicology, Technische Universität München, Munich, Germany
- German Center for Cardiovascular Research, Partner Site Munich Heart Alliance, Munich, Germany
| | - Florian Scheufele
- Institute of Pharmacology and Toxicology, Technische Universität München, Munich, Germany
- German Center for Cardiovascular Research, Partner Site Munich Heart Alliance, Munich, Germany
| | - Deepak Ramanujam
- Institute of Pharmacology and Toxicology, Technische Universität München, Munich, Germany
- German Center for Cardiovascular Research, Partner Site Munich Heart Alliance, Munich, Germany
| | - Kathleen Meyer
- Institute of Pharmacology and Toxicology, Technische Universität München, Munich, Germany
- German Center for Cardiovascular Research, Partner Site Munich Heart Alliance, Munich, Germany
| | - Hidehiro Nakajima
- Wells Center for Pediatric Research and Krannert Institute of Cardiology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Loren J. Field
- Wells Center for Pediatric Research and Krannert Institute of Cardiology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Stefan Engelhardt
- Institute of Pharmacology and Toxicology, Technische Universität München, Munich, Germany
- German Center for Cardiovascular Research, Partner Site Munich Heart Alliance, Munich, Germany
| | - Antonio Sarikas
- Institute of Pharmacology and Toxicology, Paracelsus Medical University, Salzburg, Austria
- * E-mail:
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7
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Pan ZQ. Cullin-RING E3 Ubiquitin Ligase 7 in Growth Control and Cancer. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1217:285-296. [PMID: 31898234 PMCID: PMC8343956 DOI: 10.1007/978-981-15-1025-0_17] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
CRL7Fbxw8 is an E3 ubiquitin ligase complex, containing cullin7 (CUL7) as a scaffold, the F-box protein Fbxw8 as a substrate receptor, the Skp1 adaptor, and the ROC1/Rbx1 RING finger protein for working with E2 enzyme to facilitate ubiquitin transfer. This chapter provides an update on studies linking CRL7Fbxw8 to hereditary human growth retardation disease, as at least 64 cul7 germ line mutations were found in patients with autosomal recessive 3-M syndrome. CRL7Fbxw8 interacts with two additional 3-M associated proteins OBSL1 and CCDC8, leading to subcellular localization of the E3 complex to regions including plasma membrane, centrosome, and Golgi. At least ten mammalian cellular proteins were identified or implicated as CRL7Fbxw8 substrates. Discussion focuses on the possible impact of CRL7Fbxw8-mediated proteolytic or non-proteolytic pathways in growth control and cancer.
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Affiliation(s)
- Zhen-Qiang Pan
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
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8
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Frendo-Cumbo S, Jaldin-Fincati JR, Coyaud E, Laurent EMN, Townsend LK, Tan JMJ, Xavier RJ, Pillon NJ, Raught B, Wright DC, Brumell JH, Klip A. Deficiency of the autophagy gene ATG16L1 induces insulin resistance through KLHL9/KLHL13/CUL3-mediated IRS1 degradation. J Biol Chem 2019; 294:16172-16185. [PMID: 31515271 DOI: 10.1074/jbc.ra119.009110] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2019] [Revised: 08/29/2019] [Indexed: 12/23/2022] Open
Abstract
Connections between deficient autophagy and insulin resistance have emerged, however, the mechanism through which reduced autophagy impairs insulin-signaling remains unknown. We examined mouse embryonic fibroblasts lacking Atg16l1 (ATG16L1 KO mouse embryonic fibroblasts (MEFs)), an essential autophagy gene, and observed deficient insulin and insulin-like growth factor-1 signaling. ATG16L1 KO MEFs displayed reduced protein content of insulin receptor substrate-1 (IRS1), pivotal to insulin signaling, whereas IRS1myc overexpression recovered downstream insulin signaling. Endogenous IRS1 protein content and insulin signaling were restored in ATG16L1 KO mouse embryonic fibroblasts (MEF) upon proteasome inhibition. Through proximity-dependent biotin identification (BioID) and co-immunoprecipitation, we found that Kelch-like proteins KLHL9 and KLHL13, which together form an E3 ubiquitin (Ub) ligase complex with cullin 3 (CUL3), are novel IRS1 interactors. Expression of Klhl9 and Klhl13 was elevated in ATG16L1 KO MEFs and siRNA-mediated knockdown of Klhl9, Klhl13, or Cul3 recovered IRS1 expression. Moreover, Klhl13 and Cul3 knockdown increased insulin signaling. Notably, adipose tissue of high-fat fed mice displayed lower Atg16l1 mRNA expression and IRS1 protein content, and adipose tissue KLHL13 and CUL3 expression positively correlated to body mass index in humans. We propose that ATG16L1 deficiency evokes insulin resistance through induction of Klhl9 and Klhl13, which, in complex with Cul3, promote proteasomal IRS1 degradation.
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Affiliation(s)
- Scott Frendo-Cumbo
- Cell Biology Program, Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada.,Department of Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | | | - Etienne Coyaud
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario M5G 2C1, Canada
| | - Estelle M N Laurent
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario M5G 2C1, Canada
| | - Logan K Townsend
- Department of Human Health & Nutritional Sciences, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Joel M J Tan
- Cell Biology Program, Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
| | - Ramnik J Xavier
- Gastrointestinal Unit and Center for the Study of Inflammatory Bowel Disease, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114
| | - Nicolas J Pillon
- Departments of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden 171 77
| | - Brian Raught
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario M5G 2C1, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5G 1L7, Canada
| | - David C Wright
- Department of Human Health & Nutritional Sciences, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - John Hunter Brumell
- Cell Biology Program, Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada .,Department of Institute of Medical Science, University of Toronto, Toronto, Ontario M5S 1A8, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada.,SickKids IBD Centre, Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
| | - Amira Klip
- Cell Biology Program, Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada .,Department of Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada.,Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
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9
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Zhang H, Zhang C, Tang H, Gao S, Sun F, Yang Y, Zhou W, Hu Y, Ke C, Wu Y, Ding Z, Guo L, Pei R, Chen X, Sy M, Zhang B, Li C. CD2-Associated Protein Contributes to Hepatitis C, Virus Propagation and Steatosis by Disrupting Insulin Signaling. Hepatology 2018; 68:1710-1725. [PMID: 29729186 PMCID: PMC6220802 DOI: 10.1002/hep.30073] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Revised: 04/11/2018] [Accepted: 04/30/2018] [Indexed: 12/12/2022]
Abstract
Chronic hepatitis C virus (HCV) infection can result in steatosis, a condition displaying aberrant accumulation of neutral lipid vesicles, the component of lipid droplets (LDs), which are essential for HCV assembly. However, the interplay between HCV infection and steatosis remains unclear. Here, we show that HCV-infected cells have higher levels of CD2-associated protein (CD2AP), which plays two distinct, yet tightly linked, roles in HCV pathogenesis: Elevated CD2AP binds to nonstructural protein 5A (NS5A) and participates in the transport of NS5A to LDs to facilitate viral assembly; Up-regulated CD2AP also interacts with casitas B-lineage lymphoma (b) (Cbl/Cbl-b) E3 ligases to degrade insulin receptor substrate 1 (IRS1), which, in turn, disrupts insulin signaling and increases LD accumulation through the IRS1/protein kinase B (Akt)/adenosine monophosphate-activated protein kinase (AMPK)/hormone-sensitive lipase (HSL) signaling axis to accommodate viral assembly. In the HCV-infected mouse model, CD2AP expression is up-regulated during the chronic infection stage and this up-regulation correlates well with liver steatosis. Importantly, CD2AP up-regulation was also detected in HCV-infected human liver biopsies showing steatosis compared to non-HCV-infected controls. Conclusion: CD2AP is indicated as a protein up-regulated by HCV infection, which, in turn, stimulates HCV propagation and steatosis by disrupting insulin signaling; targeting CD2AP may offer an opportunity for alleviating HCV infection and its associated liver pathology. (Hepatology 2018;XX:XXX-XXX.).
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Affiliation(s)
- Huixia Zhang
- Center for Molecular VirologyWuhan Institute of VirologyState Key Laboratory of VirologyChinese Academy of SciencesWuhanChina
- University of Chinese Academy of SciencesBeijingChina
| | - Chao Zhang
- Key laboratory of Infection and Immunity, Institute of BiophysicsChinese Academy of SciencesBeijingChina
| | - Hong Tang
- Institute Pasteur of Shanghai, Chinese Academy of SciencesShanghaiChina
| | - Shanshan Gao
- Center for Molecular VirologyWuhan Institute of VirologyState Key Laboratory of VirologyChinese Academy of SciencesWuhanChina
- University of Chinese Academy of SciencesBeijingChina
| | - Fang Sun
- Center for Molecular VirologyWuhan Institute of VirologyState Key Laboratory of VirologyChinese Academy of SciencesWuhanChina
- University of Chinese Academy of SciencesBeijingChina
| | - Yuan Yang
- Eastern Hepatobiliary Surgery Hospital, Second Military Medical UniversityShanghaiChina
| | - Weiping Zhou
- Eastern Hepatobiliary Surgery Hospital, Second Military Medical UniversityShanghaiChina
| | - Yu Hu
- Hepatic Surgery CenterTongji Hospital, Tongji Medical College, Huazhong University of Science and TechnologyWuhanChina
| | - Changshu Ke
- Hepatic Surgery CenterTongji Hospital, Tongji Medical College, Huazhong University of Science and TechnologyWuhanChina
| | - Yu Wu
- Hepatic Surgery CenterTongji Hospital, Tongji Medical College, Huazhong University of Science and TechnologyWuhanChina
| | - Zeyang Ding
- Hepatic Surgery CenterTongji Hospital, Tongji Medical College, Huazhong University of Science and TechnologyWuhanChina
| | - Lin Guo
- School of Life SciencesWuhan UniversityState Key Laboratory of VirologyWuhanChina
| | - Rongjuan Pei
- Center for Molecular VirologyWuhan Institute of VirologyState Key Laboratory of VirologyChinese Academy of SciencesWuhanChina
| | - Xinwen Chen
- Center for Molecular VirologyWuhan Institute of VirologyState Key Laboratory of VirologyChinese Academy of SciencesWuhanChina
| | - Man‐Sun Sy
- Department of Pathology, School of MedicineCase Western Reserve UniversityClevelandOH
| | - Bixiang Zhang
- Hepatic Surgery CenterTongji Hospital, Tongji Medical College, Huazhong University of Science and TechnologyWuhanChina
| | - Chaoyang Li
- Center for Molecular VirologyWuhan Institute of VirologyState Key Laboratory of VirologyChinese Academy of SciencesWuhanChina
- School of Chemistry, Chemical Engineering, and Life SciencesWuhan University of TechnologyWuhanChina
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10
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Balaji V, Pokrzywa W, Hoppe T. Ubiquitylation Pathways In Insulin Signaling and Organismal Homeostasis. Bioessays 2018; 40:e1700223. [PMID: 29611634 DOI: 10.1002/bies.201700223] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 02/26/2018] [Indexed: 12/26/2022]
Abstract
The insulin/insulin-like growth factor-1 (IGF-1) signaling (IIS) pathway is a pivotal genetic program regulating cell growth, tissue development, metabolic physiology, and longevity of multicellular organisms. IIS integrates a fine-tuned cascade of signaling events induced by insulin/IGF-1, which is precisely controlled by post-translational modifications. The ubiquitin/proteasome-system (UPS) influences the functionality of IIS through inducible ubiquitylation pathways that regulate internalization of the insulin/IGF-1 receptor, the stability of downstream insulin/IGF-1 signaling targets, and activity of nuclear receptors for control of gene expression. An age-related decline in UPS activity is often associated with an impairment of IIS, contributing to pathologies such as cancer, diabetes, cardiovascular, and neurodegenerative disorders. Recent findings identified a key role of diverse ubiquitin modifications in insulin signaling decisions, which governs dynamic adaption upon environmental and physiological changes. In this review, we discuss the mutual crosstalk between ubiquitin and insulin signaling pathways in the context of cellular and organismal homeostasis.
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Affiliation(s)
- Vishnu Balaji
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Joseph-Stelzmann Str. 26, 50931 Cologne, Germany
| | - Wojciech Pokrzywa
- Laboratory of Protein Metabolism in Development and Aging, International Institute of Molecular and Cell Biology, Warsaw, Poland
| | - Thorsten Hoppe
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Joseph-Stelzmann Str. 26, 50931 Cologne, Germany
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11
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Forand A. PiT1 : du transport de phosphate à la signalisation insulinique. Med Sci (Paris) 2017; 33:480-483. [DOI: 10.1051/medsci/20173305007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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12
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Coffee extract inhibits adipogenesis in 3T3-L1 preadipocyes by interrupting insulin signaling through the downregulation of IRS1. PLoS One 2017; 12:e0173264. [PMID: 28282409 PMCID: PMC5345824 DOI: 10.1371/journal.pone.0173264] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 02/17/2017] [Indexed: 12/11/2022] Open
Abstract
Although epidemiological data have indicated that a strong negative association exists between coffee consumption and the prevalence of obesity-associated diseases, the molecular mechanisms by which coffee intake prevents obesity-associated diseases has not yet been elucidated. In this study, we found that coffee intake significantly suppressed high-fat diet (HFD)-induced metabolic alternations such as increases in body weight and the accumulation of adipose tissue, and up-regulation of glucose, free fatty acid, total cholesterol and insulin levels in the blood. We also found that coffee extract significantly inhibited adipogenesis in 3T3-L1 preadipocytes. In the early phase of adipogenesis, 3T3-L1 cells treated with coffee extract displayed the retardation of cell cycle entry into the G2/M phase called as mitotic clonal expansion (MCE). Coffee extract also inhibited the activation of CCAAT/enhancer-binding protein β (C/EBPβ) by preventing its phosphorylation by ERK. Furthermore, the coffee extract suppressed the adipogenesis-related events such as MCE and C/EBPβ activation through the down-regulation of insulin receptor substrate 1 (IRS1). The stability of the IRS1 protein was markedly decreased by the treatment with coffee extract due to proteasomal degradation. These results have revealed an anti-adipogenic function for coffee intake and identified IRS1 as a novel target for coffee extract in adipogenesis.
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13
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Disruption of the Phosphate Transporter Pit1 in Hepatocytes Improves Glucose Metabolism and Insulin Signaling by Modulating the USP7/IRS1 Interaction. Cell Rep 2016; 16:2736-2748. [PMID: 27568561 DOI: 10.1016/j.celrep.2016.08.012] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 06/02/2016] [Accepted: 08/03/2016] [Indexed: 01/07/2023] Open
Abstract
The liver plays a central role in whole-body lipid and glucose homeostasis. Increasing dietary fat intake results in increased hepatic fat deposition, which is associated with a risk for development of insulin resistance and type 2 diabetes. In this study, we demonstrate a role for the phosphate inorganic transporter 1 (PiT1/SLC20A1) in regulating metabolism. Specific knockout of Pit1 in hepatocytes significantly improved glucose tolerance and insulin sensitivity, enhanced insulin signaling, and decreased hepatic lipogenesis. We identified USP7 as a PiT1 binding partner and demonstrated that Pit1 deletion inhibited USP7/IRS1 dissociation upon insulin stimulation. This prevented IRS1 ubiquitination and its subsequent proteasomal degradation. As a consequence, delayed insulin negative feedback loop and sustained insulin signaling were observed. Moreover, PiT1-deficient mice were protected against high-fat-diet-induced obesity and diabetes. Our findings indicate that PiT1 has potential as a therapeutic target in the context of metabolic syndrome, obesity, and diabetes.
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14
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Yang XD, Xiang DX, Yang YY. Role of E3 ubiquitin ligases in insulin resistance. Diabetes Obes Metab 2016; 18:747-54. [PMID: 27097743 DOI: 10.1111/dom.12677] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 04/09/2016] [Accepted: 04/17/2016] [Indexed: 12/19/2022]
Abstract
E3 ubiquitin ligases are a large family of proteins that catalyse the ubiquitination of many proteins for degradation by the 26S proteasome. E3 ubiquitin ligases play pivotal roles in the process of insulin resistance and diabetes. In this review, we summarize the currently available studies to analyse the potential role of E3 ubiquitin ligases in the development of insulin resistance. We propose two mechanisms by which E3 ubiquitin ligases can affect the process of insulin resistance. First, E3 ubiquitin ligases directly degrade the insulin receptor, insulin receptor substrate and other key insulin signalling molecules via the UPS. Second, E3 ubiquitin ligases indirectly regulate insulin signalling by regulating pro-inflammatory mediators that are involved in the regulation of insulin signalling molecules, such as tumour necrosis factor-α, interleukin (IL)-6, IL-4, IL-13, IL-1β, monocyte chemoattractant protein-1 and hypoxia-inducible factor 1α. Determining the mechanism by which E3 ubiquitin ligases affect the development of insulin resistance can identify a novel strategy to protect against insulin resistance and diabetes.
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Affiliation(s)
- X-D Yang
- Department of Pharmacy, the Second Xiangya Hospital, Central South University, Changsha, China
| | - D-X Xiang
- Department of Pharmacy, the Second Xiangya Hospital, Central South University, Changsha, China
| | - Y-Y Yang
- Department of Pharmacy, the Second Xiangya Hospital, Central South University, Changsha, China
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15
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Hançer NJ, Qiu W, Cherella C, Li Y, Copps KD, White MF. Insulin and metabolic stress stimulate multisite serine/threonine phosphorylation of insulin receptor substrate 1 and inhibit tyrosine phosphorylation. J Biol Chem 2014; 289:12467-84. [PMID: 24652289 PMCID: PMC4007441 DOI: 10.1074/jbc.m114.554162] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Revised: 03/18/2014] [Indexed: 12/27/2022] Open
Abstract
IRS1 and IRS2 are key substrates of the insulin receptor tyrosine kinase. Mass spectrometry reveals more than 50 phosphorylated IRS1 serine and threonine residues (Ser(P)/Thr(P) residues) in IRS1 from insulin-stimulated cells or human tissues. We investigated a subset of IRS1 Ser(P)/Thr(P) residues using a newly developed panel of 25 phospho-specific monoclonal antibodies (αpS/TmAb(Irs1)). CHO cells overexpressing the human insulin receptor and rat IRS1 were stimulated with insulin in the absence or presence of inhibitors of the PI3K → Akt → mechanistic target of rapamycin (mTOR) → S6 kinase or MEK pathways. Nearly all IRS1 Ser(P)/Thr(P) residues were stimulated by insulin and significantly suppressed by PI3K inhibition; fewer were suppressed by Akt or mTOR inhibition, and none were suppressed by MEK inhibition. Insulin-stimulated Irs1 tyrosine phosphorylation (Tyr(P)(Irs1)) was enhanced by inhibition of the PI3K → Akt → mTOR pathway and correlated with decreased Ser(P)-302(Irs1), Ser(P)-307(Irs1), Ser(P)-318(Irs1), Ser(P)-325(Irs1), and Ser(P)-346(Irs1). Metabolic stress modeled by anisomycin, thapsigargin, or tunicamycin increased many of the same Ser(P)/Thr(P) residues as insulin, some of which (Ser(P)-302(Irs1), Ser(P)-307(Irs1), and four others) correlated significantly with impaired insulin-stimulated Tyr(P)(Irs1). Thus, IRS1 Ser(P)/Thr(P) is an integrated response to insulin stimulation and metabolic stress, which associates with reduced Tyr(P)(Irs1) in CHO(IR)/IRS1 cells.
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Affiliation(s)
- Nancy J. Hançer
- From the Division of Endocrinology, Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts 02115
| | - Wei Qiu
- From the Division of Endocrinology, Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts 02115
| | - Christine Cherella
- From the Division of Endocrinology, Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts 02115
| | - Yedan Li
- From the Division of Endocrinology, Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts 02115
| | - Kyle D. Copps
- From the Division of Endocrinology, Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts 02115
| | - Morris F. White
- From the Division of Endocrinology, Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts 02115
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16
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Renal tumours in a Tsc2+/− mouse model do not show feedback inhibition of Akt and are effectively prevented by rapamycin. Oncogene 2014; 34:922-31. [DOI: 10.1038/onc.2014.17] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Revised: 01/30/2014] [Accepted: 02/01/2014] [Indexed: 12/18/2022]
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17
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Inhibition of Cullin-RING E3 ubiquitin ligase 7 by simian virus 40 large T antigen. Proc Natl Acad Sci U S A 2014; 111:3371-6. [PMID: 24550499 DOI: 10.1073/pnas.1401556111] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Simian virus 40 (SV40) large tumor antigen (LT) triggers oncogenic transformation by inhibition of key tumor suppressor proteins, including p53 and members of the retinoblastoma family. In addition, SV40 transformation requires binding of LT to Cullin 7 (CUL7), a core component of Cullin-RING E3 ubiquitin ligase 7 (CRL7). However, the pathomechanistic effects of LT-CUL7 interaction are mostly unknown. Here we report both in vitro and in vivo experimental evidence that SV40 LT suppresses the ubiquitin ligase function of CRL7. We show that SV40 LT, but not a CUL7 binding-deficient mutant (LT(Δ69-83)), impaired 26S proteasome-dependent proteolysis of the CRL7 target protein insulin receptor substrate 1 (IRS1), a component of the insulin and insulin-like growth factor 1 signaling pathway. SV40 LT expression resulted in the accumulation and prolonged half-life of IRS1. In vitro, purified SV40 LT reduced CRL7-dependent IRS1 ubiquitination in a concentration-dependent manner. Expression of SV40 LT, or depletion of CUL7 by RNA interference, resulted in the enhanced activation of IRS1 downstream signaling pathways phosphatidylinositol-3-kinase/AKT and Erk mitogen-activated pathway kinase, as well as up-regulation of the downstream target gene c-fos. Finally, SV40 LT-positive carcinoma of carcinoembryonic antigen 424/SV40 LT transgenic mice displayed elevated IRS1 protein levels and activation of downstream signaling. Taken together, these data suggest that SV40 LT protects IRS1 from CRL7-mediated degradation, thereby sustaining high levels of promitogenic IRS1 downstream signaling pathways.
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18
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Scheufele F, Wolf B, Kruse M, Hartmann T, Lempart J, Mühlich S, Pfeiffer AFH, Field LJ, Charron MJ, Pan ZQ, Engelhardt S, Sarikas A. Evidence for a regulatory role of Cullin-RING E3 ubiquitin ligase 7 in insulin signaling. Cell Signal 2013; 26:233-239. [PMID: 24219910 DOI: 10.1016/j.cellsig.2013.11.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Accepted: 11/01/2013] [Indexed: 01/05/2023]
Abstract
Dysfunctional regulation of signaling pathways downstream of the insulin receptor plays a pivotal role in the pathogenesis of insulin resistance and type 2 diabetes. In this study we report both in vitro and in vivo experimental evidence for a role of Cullin-RING E3 ubiquitin ligase 7 (CRL7) in the regulation of insulin signaling and glucose homeostasis. We show that Cul7(-/-) mouse embryonic fibroblasts displayed enhanced AKT and Erk MAP kinase phosphorylation upon insulin stimulation. Depletion of CUL7 by RNA interference in C2C12 myotubes led to increased activation of insulin signaling pathways and cellular glucose uptake, as well as a reduced capacity of these cells to execute insulin-induced degradation of insulin receptor substrate 1 (IRS1). In vivo, heterozygosity of either Cul7 or Fbxw8, both key components of CRL7, resulted in elevated PI3 kinase/AKT activation in skeletal muscle tissue upon insulin stimulation when compared to wild-type controls. Finally, Cul7(+/-) or Fbxw8(+/-) mice exhibited enhanced insulin sensitivity and plasma glucose clearance. Collectively, our findings point to a yet unrecognized role of CRL7 in insulin-mediated control of glucose homeostasis by restraining PI3 kinase/AKT activities in skeletal muscle cells.
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Affiliation(s)
- Florian Scheufele
- Institute of Pharmacology and Toxicology, Technische Universität München, Biedersteiner Straße 29, 80802 Munich, Germany
| | - Benjamin Wolf
- Institute of Pharmacology and Toxicology, Technische Universität München, Biedersteiner Straße 29, 80802 Munich, Germany
| | - Michael Kruse
- German Institute of Human Nutrition Potsdam-Rehbrücke, Department of Clinical Nutrition, Arthur-Scheunert-Allee 114-116, 14558 Nuthetal, Germany.,Departments of Biochemistry, Medicine (Endocrinology) and Obstetrics & Gynecology and Women's Health, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | - Thomas Hartmann
- Institute of Pharmacology and Toxicology, Technische Universität München, Biedersteiner Straße 29, 80802 Munich, Germany
| | - Justine Lempart
- Institute of Pharmacology and Toxicology, Technische Universität München, Biedersteiner Straße 29, 80802 Munich, Germany
| | - Susanne Mühlich
- Walther-Straub-Institute of Pharmacology and Toxicology, Ludwig-Maximilians-University, Goethestraße 33, 80336 Munich, Germany
| | - Andreas F H Pfeiffer
- German Institute of Human Nutrition Potsdam-Rehbrücke, Department of Clinical Nutrition, Arthur-Scheunert-Allee 114-116, 14558 Nuthetal, Germany.,Department of Endocrinology, Diabetes and Nutrition, Charité University Medicine, 10117 Berlin, Germany
| | - Loren J Field
- Krannert Institute of Cardiology, University of Indiana, Indianapolis, IN 46202, USA
| | - Maureen J Charron
- Departments of Biochemistry, Medicine (Endocrinology) and Obstetrics & Gynecology and Women's Health, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | - Zhen-Qiang Pan
- Mount Sinai School of Medicine, Icahn Medical Institute, Dept. of Oncological Sciences, 1425 Madison Avenue, New York, NY 10029, USA
| | - Stefan Engelhardt
- Institute of Pharmacology and Toxicology, Technische Universität München, Biedersteiner Straße 29, 80802 Munich, Germany.,DZHK (German Center for Cardiovascular Research), partner site Munich Heart Alliance, 80802 Munich, Germany
| | - Antonio Sarikas
- Institute of Pharmacology and Toxicology, Technische Universität München, Biedersteiner Straße 29, 80802 Munich, Germany.,DZHK (German Center for Cardiovascular Research), partner site Munich Heart Alliance, 80802 Munich, Germany
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