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Yao Z, Gong Y, Chen W, Shao S, Song Y, Guo H, Li Q, Liu S, Wang X, Zhang Z, Wang Q, Xu Y, Wu Y, Wan Q, Zhao X, Xuan Q, Wang D, Lin X, Xu J, Liu J, Proud CG, Wang X, Yang R, Fu L, Niu S, Kong J, Gao L, Bo T, Zhao J. Upregulation of WDR6 drives hepatic de novo lipogenesis in insulin resistance in mice. Nat Metab 2023; 5:1706-1725. [PMID: 37735236 PMCID: PMC10590755 DOI: 10.1038/s42255-023-00896-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 08/23/2023] [Indexed: 09/23/2023]
Abstract
Under normal conditions, insulin promotes hepatic de novo lipogenesis (DNL). However, during insulin resistance (IR), when insulin signalling is blunted and accompanied by hyperinsulinaemia, the promotion of hepatic DNL continues unabated and hepatic steatosis increases. Here, we show that WD40 repeat-containing protein 6 (WDR6) promotes hepatic DNL during IR. Mechanistically, WDR6 interacts with the beta-type catalytic subunit of serine/threonine-protein phosphatase 1 (PPP1CB) to facilitate PPP1CB dephosphorylation at Thr316, which subsequently enhances fatty acid synthases transcription through DNA-dependent protein kinase and upstream stimulatory factor 1. Using molecular dynamics simulation analysis, we find a small natural compound, XLIX, that inhibits the interaction of WDR6 with PPP1CB, thus reducing DNL in IR states. Together, these results reveal WDR6 as a promising target for the treatment of hepatic steatosis.
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Affiliation(s)
- Zhenyu Yao
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
- Shandong Clinical Research Center of Diabetes and Metabolic Diseases, Jinan, China
- Shandong Key Laboratory of Endocrinology and Lipid Metabolism, Jinan, China
- Shandong Prevention and Control Engineering Laboratory of Endocrine and Metabolic Diseases, Jinan, China
| | - Ying Gong
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
- Shandong Clinical Research Center of Diabetes and Metabolic Diseases, Jinan, China
- Shandong Key Laboratory of Endocrinology and Lipid Metabolism, Jinan, China
- Shandong Prevention and Control Engineering Laboratory of Endocrine and Metabolic Diseases, Jinan, China
| | - Wenbin Chen
- Central Laboratory, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Shanshan Shao
- Shandong Prevention and Control Engineering Laboratory of Endocrine and Metabolic Diseases, Jinan, China
| | - Yongfeng Song
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
- Shandong Clinical Research Center of Diabetes and Metabolic Diseases, Jinan, China
- Shandong Key Laboratory of Endocrinology and Lipid Metabolism, Jinan, China
- Shandong Prevention and Control Engineering Laboratory of Endocrine and Metabolic Diseases, Jinan, China
| | - Honglin Guo
- Department of Pathology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Qihang Li
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
- Shandong Clinical Research Center of Diabetes and Metabolic Diseases, Jinan, China
- Shandong Key Laboratory of Endocrinology and Lipid Metabolism, Jinan, China
- Shandong Prevention and Control Engineering Laboratory of Endocrine and Metabolic Diseases, Jinan, China
| | - Sijin Liu
- Medical Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, China
| | - Ximing Wang
- Department of Radiology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Zhenhai Zhang
- Department of Hepatobiliary Surgery, Shandong Provincial Hospital, Shandong University, Jinan, China
| | - Qian Wang
- Department of Ultrasound, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Yunyun Xu
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
- Shandong Clinical Research Center of Diabetes and Metabolic Diseases, Jinan, China
- Shandong Key Laboratory of Endocrinology and Lipid Metabolism, Jinan, China
- Shandong Prevention and Control Engineering Laboratory of Endocrine and Metabolic Diseases, Jinan, China
| | - Yingjie Wu
- Shandong Provincial Hospital, School of Laboratory Animal & Shandong Laboratory Animal Center, Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, China
- Institute of Genome Engineered Animal Models, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Qiang Wan
- Center of Cell Metabolism and Disease, Jinan Central Hospital, Shandong First Medical University, Jinan, China
| | - Xinya Zhao
- Department of Radiology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Qiuhui Xuan
- Shandong Clinical Research Center of Diabetes and Metabolic Diseases, Jinan, China
- Shandong Key Laboratory of Endocrinology and Lipid Metabolism, Jinan, China
- Shandong Prevention and Control Engineering Laboratory of Endocrine and Metabolic Diseases, Jinan, China
| | - Dawei Wang
- Shandong Clinical Research Center of Diabetes and Metabolic Diseases, Jinan, China
- Shandong Key Laboratory of Endocrinology and Lipid Metabolism, Jinan, China
- Shandong Prevention and Control Engineering Laboratory of Endocrine and Metabolic Diseases, Jinan, China
| | - Xiaoyan Lin
- Department of Pathology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Jiawen Xu
- Department of Pathology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Jun Liu
- Department of Liver Transplantation and Hepatobiliary Surgery, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Christopher G Proud
- Lifelong Health, South Australian Health & Medical Research Institute, North Terrace, Adelaide, South Australia, Australia
| | - Xuemin Wang
- Lifelong Health, South Australian Health & Medical Research Institute, North Terrace, Adelaide, South Australia, Australia
| | - Rui Yang
- Institute of Genome Engineered Animal Models, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Lili Fu
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
- Shandong Clinical Research Center of Diabetes and Metabolic Diseases, Jinan, China
- Shandong Key Laboratory of Endocrinology and Lipid Metabolism, Jinan, China
- Shandong Prevention and Control Engineering Laboratory of Endocrine and Metabolic Diseases, Jinan, China
| | - Shaona Niu
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
- Shandong Clinical Research Center of Diabetes and Metabolic Diseases, Jinan, China
- Shandong Key Laboratory of Endocrinology and Lipid Metabolism, Jinan, China
- Shandong Prevention and Control Engineering Laboratory of Endocrine and Metabolic Diseases, Jinan, China
| | - Junjie Kong
- Department of Liver Transplantation and Hepatobiliary Surgery, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Ling Gao
- Shandong Key Laboratory of Endocrinology and Lipid Metabolism, Jinan, China.
| | - Tao Bo
- Central Laboratory, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China.
| | - Jiajun Zhao
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China.
- Shandong Clinical Research Center of Diabetes and Metabolic Diseases, Jinan, China.
- Shandong Key Laboratory of Endocrinology and Lipid Metabolism, Jinan, China.
- Shandong Prevention and Control Engineering Laboratory of Endocrine and Metabolic Diseases, Jinan, China.
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Zhang H, Chen G, Feng X, Song H, Meng L, Fu Y, Yang J, Fan Z, Ding Y, Du Z, Wang J, Yang L, Zhang J, Sun L, Liu Z, Zhang Z, Li Q, Fan X. Targeting WDxR motif reprograms immune microenvironment and inhibits hepatocellular carcinoma progression. EMBO Mol Med 2023; 15:e15924. [PMID: 36947051 PMCID: PMC10165360 DOI: 10.15252/emmm.202215924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Revised: 02/25/2023] [Accepted: 02/28/2023] [Indexed: 03/23/2023] Open
Abstract
The WD-repeat (WDR) family affects carcinogenesis, but its role in the immune microenvironment is poorly characterized. Although functional loss or gain of WDR6 does not markedly change in vitro proliferative and invasive capacity of HCC cells, its deficiency in hepa1-6 cells drastically inhibits the growth and lung metastasis of orthotopically implanted tumors in immune-competent C57BL/6J mice. Mechanistically, WDR6 targets tumor suppressor UVRAG to the CUL4A-DDB1-ROC1 E3 ubiquitin ligase complex through a unique WDxR motif and promotes its degradation. This upregulates chromatin accessibility at the TNFα locus by blocking autophagic degradation of p65, elevates intratumoral myeloid-derived suppressor cell (MDSC) number, and reduces CD8+ T cell infiltration, thereby promoting HCC progression. These immunosuppressive effects are reversed by TNFα blockade. TNFα recruits NF-κB to activate the transcription of WDR6, establishing a WDR6-TNFα loop. Clinically, the WDR6/UVRAG/NF-κB pathway is hyperactivated in HCC, predicting a poor prognosis. Importantly, a WDxR-like peptide disrupts the WDR6/UVRAG complex and enhances the efficiency of anti-PD-L1 against HCC with WDR6 dysregulation.
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Affiliation(s)
- Heng Zhang
- Department of Thoracic Surgery, Renmin Hospital of Wuhan University, Wuhan, China
- Department of Histology and Embryology, Xiang Ya School of Medicine, Central South University, Changsha, China
| | - Gang Chen
- Department of Pathology, Fujian Medical University Cancer Hospital, Fujian Cancer Hospital, Fuzhou, China
| | - Xing Feng
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT, USA
| | - Huiwen Song
- Department of Cardiology, Jiading District Central Hospital Affiliated Shanghai University of Medicine & Health Sciences, Shanghai, China
| | - Lingbing Meng
- Departments of Cardiology, Beijing Hospital, National Center of Gerontology, Chinese Academy of Medical Sciences, Beijing, China
| | - Yao Fu
- Department of Pathology, The Affiliated Drum Tower Hospital, Nanjing University Medical School, Nanjing, China
| | - Jun Yang
- Department of Pathology, The Affiliated Drum Tower Hospital, Nanjing University Medical School, Nanjing, China
| | - Zhiwen Fan
- Department of Pathology, The Affiliated Drum Tower Hospital, Nanjing University Medical School, Nanjing, China
| | - Youxiang Ding
- Department of Pathology, The Affiliated Drum Tower Hospital, Nanjing University Medical School, Nanjing, China
| | - Zhijie Du
- Nanjing Drum Tower Hospital Clinical College of Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, China
| | - Jianchao Wang
- Department of Pathology, Fujian Medical University Cancer Hospital, Fujian Cancer Hospital, Fuzhou, China
| | - Li Yang
- Institute of Digestive Disease, China Three Gorges University, Yichang, China
- Department of Gastroenterology, Yichang Central People's Hospital, Yichang, China
| | - Jun Zhang
- Shenzhen Qianhai Shekou Free Trade Zone Hospital, Shenzhen, China
| | - Lixia Sun
- Department of Hepatological Surgery, The Affiliated Wuhu hospital of ECNU, Wuhu, China
| | - Zhigang Liu
- Department of Hepatological Surgery, The Affiliated Wuhu hospital of ECNU, Wuhu, China
| | - Zhiyong Zhang
- Department of Surgery, Robert-Wood-Johnson Medical School University Hospital, Rutgers University, New Brunswick, NJ, USA
- National Center for International Research of Biological Targeting Diagnosis and Therapy, Guangxi Medical University, Nanning, China
| | - Quanhai Li
- Cell Therapy Laboratory, The First Hospital of Hebei Medical University, Shijiazhuang, China
| | - Xiangshan Fan
- Department of Pathology, The Affiliated Drum Tower Hospital, Nanjing University Medical School, Nanjing, China
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Adams DM, Reay WR, Cairns MJ. Multiomic prioritisation of risk genes for anorexia nervosa. Psychol Med 2023; 53:1-9. [PMID: 36803885 PMCID: PMC10600818 DOI: 10.1017/s0033291723000235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Revised: 01/12/2023] [Accepted: 01/23/2023] [Indexed: 02/22/2023]
Abstract
BACKGROUND Anorexia nervosa (AN) is a psychiatric disorder associated with marked morbidity. Whilst AN genetic studies could identify novel treatment targets, integration of functional genomics data, including transcriptomics and proteomics, would assist to disentangle correlated signals and reveal causally associated genes. METHODS We used models of genetically imputed expression and splicing from 14 tissues, leveraging mRNA, protein, and mRNA alternative splicing weights to identify genes, proteins, and transcripts, respectively, associated with AN risk. This was accomplished through transcriptome, proteome, and spliceosome-wide association studies, followed by conditional analysis and finemapping to prioritise candidate causal genes. RESULTS We uncovered 134 genes for which genetically predicted mRNA expression was associated with AN after multiple-testing correction, as well as four proteins and 16 alternatively spliced transcripts. Conditional analysis of these significantly associated genes on other proximal association signals resulted in 97 genes independently associated with AN. Moreover, probabilistic finemapping further refined these associations and prioritised putative causal genes. The gene WDR6, for which increased genetically predicted mRNA expression was correlated with AN, was strongly supported by both conditional analyses and finemapping. Pathway analysis of genes revealed by finemapping identified the pathway regulation of immune system process (overlapping genes = MST1, TREX1, PRKAR2A, PROS1) as statistically overrepresented. CONCLUSIONS We leveraged multiomic datasets to genetically prioritise novel risk genes for AN. Multiple-lines of evidence support that WDR6 is associated with AN, whilst other prioritised genes were enriched within immune related pathways, further supporting the role of the immune system in AN.
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Affiliation(s)
- Danielle M. Adams
- School of Biomedical Sciences and Pharmacy, Centre for Complex Disease Neurobiology and Precision Medicine, The University of Newcastle, Callaghan, NSW, Australia
- Precision Medicine Research Program, Hunter Medical Research Institute, Newcastle, NSW, Australia
| | - William R. Reay
- School of Biomedical Sciences and Pharmacy, Centre for Complex Disease Neurobiology and Precision Medicine, The University of Newcastle, Callaghan, NSW, Australia
- Precision Medicine Research Program, Hunter Medical Research Institute, Newcastle, NSW, Australia
| | - Murray J. Cairns
- School of Biomedical Sciences and Pharmacy, Centre for Complex Disease Neurobiology and Precision Medicine, The University of Newcastle, Callaghan, NSW, Australia
- Precision Medicine Research Program, Hunter Medical Research Institute, Newcastle, NSW, Australia
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Tabassum S, Misrani A, Yang L. Exploiting Common Aspects of Obesity and Alzheimer's Disease. Front Hum Neurosci 2020; 14:602360. [PMID: 33384592 PMCID: PMC7769820 DOI: 10.3389/fnhum.2020.602360] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 11/24/2020] [Indexed: 12/14/2022] Open
Abstract
Alzheimer’s disease (AD) is an example of age-related dementia, and there are still no known preventive or curative measures for this disease. Obesity and associated metabolic changes are widely accepted as risk factors of age-related cognitive decline. Insulin is the prime mediator of metabolic homeostasis, which is impaired in obesity, and this impairment potentiates amyloid-β (Aβ) accumulation and the formation of neurofibrillary tangles (NFTs). Obesity is also linked with functional and morphological alterations in brain mitochondria leading to brain insulin resistance (IR) and memory deficits associated with AD. Also, increased peripheral inflammation and oxidative stress due to obesity are the main drivers that increase an individual’s susceptibility to cognitive deficits, thus doubling the risk of AD. This enhanced risk of AD is alarming in the context of a rapidly increasing global incidence of obesity and overweight in the general population. In this review, we summarize the risk factors that link obesity with AD and emphasize the point that the treatment and management of obesity may also provide a way to prevent AD.
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Affiliation(s)
- Sidra Tabassum
- Precise Genome Engineering Center, School of Life Sciences, Guangzhou University, Guangzhou, China
| | - Afzal Misrani
- Precise Genome Engineering Center, School of Life Sciences, Guangzhou University, Guangzhou, China
| | - Li Yang
- Precise Genome Engineering Center, School of Life Sciences, Guangzhou University, Guangzhou, China
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Herrera ML, Basmadjian OM, Falomir‐Lockhart E, Dolcetti FJ, Hereñú CB, Bellini MJ. Sex frailty differences in ageing mice: Neuropathologies and therapeutic projections. Eur J Neurosci 2020; 52:2827-2837. [DOI: 10.1111/ejn.14703] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 02/04/2020] [Accepted: 02/09/2020] [Indexed: 12/15/2022]
Affiliation(s)
- Macarena Lorena Herrera
- Departamento de Farmacología Facultad de Ciencias Químicas Instituto de Farmacología Experimental Córdoba (IFEC‐CONICET) Universidad Nacional de Córdoba Córdoba Argentina
- Facultad de Ciencias Médicas Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP‐CONICET) Universidad Nacional de La Plata Buenos Aires Argentina
| | - Osvaldo Martin Basmadjian
- Departamento de Farmacología Facultad de Ciencias Químicas Instituto de Farmacología Experimental Córdoba (IFEC‐CONICET) Universidad Nacional de Córdoba Córdoba Argentina
| | - Eugenia Falomir‐Lockhart
- Facultad de Ciencias Médicas Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP‐CONICET) Universidad Nacional de La Plata Buenos Aires Argentina
| | - Franco Juan‐Cruz Dolcetti
- Facultad de Ciencias Médicas Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP‐CONICET) Universidad Nacional de La Plata Buenos Aires Argentina
| | - Claudia Beatriz Hereñú
- Departamento de Farmacología Facultad de Ciencias Químicas Instituto de Farmacología Experimental Córdoba (IFEC‐CONICET) Universidad Nacional de Córdoba Córdoba Argentina
| | - María José Bellini
- Facultad de Ciencias Médicas Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP‐CONICET) Universidad Nacional de La Plata Buenos Aires Argentina
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Identification of Restriction Factors by Human Genome-Wide RNA Interference Screening of Viral Host Range Mutants Exemplified by Discovery of SAMD9 and WDR6 as Inhibitors of the Vaccinia Virus K1L-C7L- Mutant. mBio 2015; 6:e01122. [PMID: 26242627 PMCID: PMC4526713 DOI: 10.1128/mbio.01122-15] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
RNA interference (RNAi) screens intended to identify host factors that restrict virus replication may fail if the virus already counteracts host defense mechanisms. To overcome this limitation, we are investigating the use of viral host range mutants that exhibit impaired replication in nonpermissive cells. A vaccinia virus (VACV) mutant with a deletion of both the C7L and K1L genes, K1L−C7L−, which abrogates replication in human cells at a step prior to late gene expression, was chosen for this strategy. We carried out a human genome-wide small interfering RNA (siRNA) screen in HeLa cells infected with a VACV K1L−C7L− mutant that expresses the green fluorescent protein regulated by a late promoter. This positive-selection screen had remarkably low background levels and resulted in the identification of a few cellular genes, notably SAMD9 and WDR6, from approximately 20,000 tested that dramatically enhanced green fluorescent protein expression. Replication of the mutant virus was enabled by multiple siRNAs to SAMD9 or WDR6. Moreover, SAMD9 and WDR6 clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9 knockout HeLa cell lines were permissive for replication of the K1L−C7L− mutant, in agreement with the siRNA data. Expression of exogenous SAMD9 or interferon regulatory factor 1 restricted replication of the K1L−C7L− mutant in the SAMD9−/− cells. Independent interactions of SAMD9 with the K1 and C7 proteins were suggested by immunoprecipitation. Knockout of WDR6 did not reduce the levels of SAMD9 and interactions of WDR6 with SAMD9, C7, and K1 proteins were not detected, suggesting that these restriction factors act independently but possibly in the same innate defense pathway. The coevolution of microbial pathogens with cells has led to an arms race in which the invader and host continuously struggle to gain the advantage. For this reason, traditional siRNA screens may fail to uncover important immune mechanisms if the pathogens have already developed effective responses. However, host-restricted viral mutants have lost one or more defense genes needed for their replication in nonpermissive cells. By screening human genome libraries of short RNAs that inhibit the expression of individual host genes in nonpermissive cells, we identified SAMD9 and WDR6 as major restriction factors that prevented replication of a vaccinia virus mutant and suggest that host range screening can be generally useful for the investigation of host-pathogen interactions.
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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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Hoxhaj G, Dissanayake K, MacKintosh C. Effect of IRS4 levels on PI 3-kinase signalling. PLoS One 2013; 8:e73327. [PMID: 24039912 PMCID: PMC3769281 DOI: 10.1371/journal.pone.0073327] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Accepted: 07/25/2013] [Indexed: 11/20/2022] Open
Abstract
Insulin receptor substrate 1 (IRS1) and IRS2 are well-characterized adapter proteins that relay signals from receptor tyrosine kinases to downstream components of signalling pathways. In contrast, the function of IRS4 is not well understood. IRS4 overexpression has been associated with acute lymphoblastic leukaemia and subungual exostosis, while point mutations of IRS4 have been found in melanomas. Here, we show that while IRS4 expression is low in most cancer cell lines, IRS4 mRNA and protein levels are markedly elevated in certain cells including the NCI-H720, DMS114, HEK293T and HEK293AAV lines. Surprisingly, IRS4 expression was also strongly induced when HEK293 cells were infected with retroviral particles and selected under puromycin, making IRS4 expression a potential off-target effect of retroviral expression vectors. Cells with high expression of IRS4 displayed high phosphatidylinositol (3,4,5)-trisphosphate (PIP3) levels, as well as elevated Akt and p70 S6 kinase activities, even in the absence of growth factors. PI 3-kinase (PI3K) signalling in these cells depends on IRS4, even though these cells also express IRS1/2. Knockdown of IRS4 also inhibited cell proliferation in cells with high levels of IRS4. Together, these findings suggest IRS4 as a potential therapeutic target for cancers with high expression of this protein.
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Affiliation(s)
- Gerta Hoxhaj
- Medical Research Council Protein Phosphorylation Unit, College of Life Sciences, University of Dundee, Dundee, Scotland, United Kingdom
- * E-mail: (GH); (CM)
| | - Kumara Dissanayake
- Division of Cell and Developmental Biology, College of Life Sciences, University of Dundee, Dundee, Scotland, United Kingdom
| | - Carol MacKintosh
- Medical Research Council Protein Phosphorylation Unit, College of Life Sciences, University of Dundee, Dundee, Scotland, United Kingdom
- Division of Cell and Developmental Biology, College of Life Sciences, University of Dundee, Dundee, Scotland, United Kingdom
- * E-mail: (GH); (CM)
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Novel binding partners and differentially regulated phosphorylation sites clarify Eps8 as a multi-functional adaptor. PLoS One 2013; 8:e61513. [PMID: 23626693 PMCID: PMC3634024 DOI: 10.1371/journal.pone.0061513] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2012] [Accepted: 03/09/2013] [Indexed: 12/02/2022] Open
Abstract
Eps8 is involved in both cell signalling and receptor trafficking. It is a known phosphorylation substrate for two proteins involved in the fibroblast growth factor receptor (FGFR) signalling pathway: the receptor itself and Src. Here we report a differential proteomic analysis of Eps8 aimed to identify specific FGFR and Src family kinase dependent phosphosites and co-associated phosphodependent binding partners. This study reveals a total of 22 Eps8 pTyr and pSer/Thr phosphorylation sites, including those that are dependent on Src family and FGFR kinase activity. Peptide affinity purification of proteins that bind to a selection of the pTyr phosphosites has identified a range of novel Eps8 binding partners including members of the intracellular vesicle trafficking machinery (clathrin and AP-2), proteins which have been shown to regulate activated receptor trafficking (NBR1 and Vav2), and proteins involved in receptor signalling (IRS4 and Shp2). Collectively this study significantly extends the understanding of Eps8 post-translational modification by regulated phosphorylation, identifies novel Eps8 binding partners implicated in receptor trafficking and signalling, and confirms the functions of Eps8 at the nexus of receptor signalling and vesicular trafficking.
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Pimentel GD, Dornellas APS, Rosa JC, Lira FS, Cunha CA, Boldarine VT, de Souza GIH, Hirata AE, Nascimento CMO, Oyama LM, Watanabe RLH, Ribeiro EB. High-fat diets rich in soy or fish oil distinctly alter hypothalamic insulin signaling in rats. J Nutr Biochem 2012; 23:822-8. [PMID: 21852082 DOI: 10.1016/j.jnutbio.2011.04.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2010] [Revised: 02/24/2011] [Accepted: 04/08/2011] [Indexed: 11/30/2022]
Abstract
Hypothalamic insulin inhibits food intake, preventing obesity. High-fat feeding with polyunsaturated fats may be obesogenic, but their effect on insulin action has not been elucidated. The present study evaluated insulin hypophagia and hypothalamic signaling after central injection in rats fed either control diet (15% energy from fat) or high-fat diets (50% energy from fat) enriched with either soy or fish oil. Soy rats had increased fat pad weight and serum leptin with normal body weight, serum lipid profile and peripheral insulin sensitivity. Fish rats had decreased body and fat pad weight, low leptin and corticosterone levels, and improved serum lipid profile. A 20-mU dose of intracerebroventricular (ICV) insulin inhibited food intake in control and fish groups, but failed to do so in the soy group. Hypothalamic protein levels of IR, IRS-1, IRS-2, Akt, mTOR, p70S6K and AMPK were similar among groups. ICV insulin stimulated IR tyrosine phosphorylation in control (68%), soy (36%) and fish (34%) groups. Tyrosine phosphorylation of the pp185 band was significantly stimulated in control (78%) and soy (53%) rats, but not in fish rats. IRS-1 phosphorylation was stimulated only in control rats (94%). Akt serine phosphorylation was significantly stimulated only in control (90%) and fish (78%) rats. The results showed that, rather than the energy density, the fat type was a relevant aspect of high-fat feeding, since blockade of hypothalamic insulin signal transmission and insulin hypophagia was promoted only by the high-fat soy diet, while they were preserved in the rats fed with the high-fat fish diet.
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Affiliation(s)
- Gustavo D Pimentel
- Disciplina de Fisiologia da Nutrição, Departamento de Fisiologia, Universidade Federal de São Paulo-UNIFESP, CEP 04023-062 São Paulo/SP, Brazil
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Chiba T, Tsuchiya T, Komatsu T, Mori R, Hayashi H, Shimokawa I. Development of calorie restriction mimetics as therapeutics for obesity, diabetes, inflammatory and neurodegenerative diseases. Curr Genomics 2011; 11:562-7. [PMID: 21629433 PMCID: PMC3078680 DOI: 10.2174/138920210793360934] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2010] [Revised: 09/27/2010] [Accepted: 10/12/2010] [Indexed: 12/15/2022] Open
Abstract
Calorie restriction (CR) is the most robust intervention that decreases morbidity and mortality, and thereby increases the lifespan of many organisms. Although the signaling pathways involved in the beneficial effects of CR are not yet fully understood. Several candidate pathways and key molecules have been identified. The effects of CR are highly conserved from lower organisms such as yeast to higher mammals such as rodents and monkeys. Recent studies have also demonstrated beneficial effects of CR in humans, although we need much longer studies to evaluate whether CR also increases the lifespan of humans. In reality, it is difficult for us to conduct CR interventions in humans because the subjects must be kept in a state of hunger and the duration of this state needed to achieve a clinically meaningful effect is still unknown. Thus, research in this field is focusing on the development of molecules that mimic the beneficial effects of CR without reducing food intake. Some of these candidate molecules include plant-derived functional chemicals (phyto-chemicals), synthetic small molecules, and endocrine molecules such as adipokines. Several studies have already shown that this research field may yield novel drugs for the treatment of age-related diseases such as diabetes. In this article, we describe the target pathways, candidate molecules, and strategies to develop CR mimetics.
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Affiliation(s)
- Takuya Chiba
- Department of Investigative Pathology, Graduate School of Biomedical Sciences, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523 Japan
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Chiba T, Yamaza H, Shimokawa I. Role of insulin and growth hormone/insulin-like growth factor-I signaling in lifespan extension: rodent longevity models for studying aging and calorie restriction. Curr Genomics 2011; 8:423-8. [PMID: 19412415 PMCID: PMC2647154 DOI: 10.2174/138920207783591726] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2007] [Revised: 10/15/2007] [Accepted: 10/18/2007] [Indexed: 12/26/2022] Open
Abstract
Insulin/insulin-like growth factor-I (IGF-I) pathways are recognized as critical signaling pathways involved in the control of lifespans in lower organisms to mammals. Caloric restriction (CR) reduces plasma concentration of insulin, growth hormone (GH), and IGF-I. CR retards various age-dependent disorders such as nuerodegenerative diseases and extends lifespan in laboratory rodents. These beneficial effects of CR are partly mimicked in spontaneous or genetically engineered rodent models of reduced insulin and GH/IGF-I axis. Most of these long-living rodents show increased insulin sensitivity; however, recent study has revealed that some other rodents show normal or reduced insulin sensitivity. Thus, increased insulin sensitivity might be not prerequisite for lifespan extension in insulin/GH/IGF-I altered longevity rodent models. These results highlighted that, for lifespan extension, the intracellular signaling molecules of insulin/GH/IGF-I pathways might be more important than actual peripheral or systemic insulin action.
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Affiliation(s)
- T Chiba
- Department of Investigative Pathology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki 852-8523, Japan
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Chiba T, Tsuchiya T, Komatsu T, Mori R, Hayashi H, Shimano H, Spindler SR, Shimokawa I. Development of a bioassay to screen for chemicals mimicking the anti-aging effects of calorie restriction. Biochem Biophys Res Commun 2010; 401:213-8. [DOI: 10.1016/j.bbrc.2010.09.032] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2010] [Accepted: 09/08/2010] [Indexed: 12/13/2022]
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Iskandar K, Cao Y, Hayashi Y, Nakata M, Takano E, Yada T, Zhang C, Ogawa W, Oki M, Chua S, Itoh H, Noda T, Kasuga M, Nakae J. PDK-1/FoxO1 pathway in POMC neurons regulates Pomc expression and food intake. Am J Physiol Endocrinol Metab 2010; 298:E787-98. [PMID: 20103739 DOI: 10.1152/ajpendo.00512.2009] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Both insulin and leptin signaling converge on phosphatidylinositol 3-OH kinase [PI(3)K]/3-phosphoinositide-dependent protein kinase-1 (PDK-1)/protein kinase B (PKB, also known as Akt) in proopiomelanocortin (POMC) neurons. Forkhead box-containing protein-O1 (FoxO1) is inactivated in a PI(3)K-dependent manner. However, the interrelationship between PI(3)K/PDK-1/Akt and FoxO1, and the chronic effects of the overexpression of FoxO1 in POMC neurons on energy homeostasis has not been elucidated. To determine the extent to which PDK-1 and FoxO1 signaling in POMC neurons was responsible for energy homeostasis, we generated POMC neuron-specific Pdk1 knockout mice (POMCPdk1(-/-)) and mice selectively expressing a constitutively nuclear (CN)FoxO1 or transactivation-defective (Delta256)FoxO1 in POMC neurons (CNFoxO1(POMC) or Delta256FoxO1(POMC)). POMCPdk1(-/-) mice showed increased food intake and body weight accompanied by decreased expression of Pomc gene. The CNFoxO1(POMC) mice exhibited mild obesity and hyperphagia compared with POMCPdk1(-/-) mice. Although expression of the CNFoxO1 made POMCPdk1(-/-) mice more obese due to excessive suppression of Pomc gene, overexpression of Delta256FoxO1 in POMC neurons had no effects on metabolic phenotypes and Pomc expression levels of POMCPdk1(-/-) mice. These data suggest a requirement for PDK-1 and FoxO1 in transcriptional regulation of Pomc and food intake.
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Affiliation(s)
- Kristy Iskandar
- International Center for Medical Research and Treatment, Kobe University Graduate school of Medicine, Japan
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