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Structural insights into the pSer/pThr dependent regulation of the SHP2 tyrosine phosphatase in insulin and CD28 signaling. Nat Commun 2022; 13:5439. [PMID: 36114179 PMCID: PMC9481563 DOI: 10.1038/s41467-022-32918-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 08/23/2022] [Indexed: 11/09/2022] Open
Abstract
Serine/threonine phosphorylation of insulin receptor substrate (IRS) proteins is well known to modulate insulin signaling. However, the molecular details of this process have mostly been elusive. While exploring the role of phosphoserines, we have detected a direct link between Tyr-flanking Ser/Thr phosphorylation sites and regulation of specific phosphotyrosine phosphatases. Here we present a concise structural study on how the activity of SHP2 phosphatase is controlled by an asymmetric, dual phosphorylation of its substrates. The structure of SHP2 has been determined with three different substrate peptides, unveiling the versatile and highly dynamic nature of substrate recruitment. What is more, the relatively stable pre-catalytic state of SHP2 could potentially be useful for inhibitor design. Our findings not only show an unusual dependence of SHP2 catalytic activity on Ser/Thr phosphorylation sites in IRS1 and CD28, but also suggest a negative regulatory mechanism that may also apply to other tyrosine kinase pathways as well. SHP2 is an important human tyrosine phosphatase with key roles in cancer, immune responses and insulin signaling. Here, the authors explore its substrate recognition mechanism in molecular detail and uncover a complex regulatory mechanism for this enzyme that marks specific target sites for dephosphorylation.
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Protein tyrosine phosphatase receptor type E (PTPRE) regulates the activation of wild-type KIT and KIT mutants differently. Biochem Biophys Rep 2021; 26:100974. [PMID: 33732906 PMCID: PMC7937656 DOI: 10.1016/j.bbrep.2021.100974] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 02/09/2021] [Accepted: 02/22/2021] [Indexed: 11/20/2022] Open
Abstract
Activation of receptor tyrosine kinases needs tight control by tyrosine phosphatases to keep their normal function. In this study, we investigated the regulation of activation of the type III receptor tyrosine kinase KIT by protein tyrosine phosphatase receptor type E (PTPRE). We found that PTPRE can associate with wild-type KIT and inhibit KIT activation in a dose-dependent manner, although the activation of wild-type KIT is dramatically inhibited even when PTPRE is expressed at low level. The D816V mutation of KIT is the most frequently found oncogenic mutation in mastocytosis, and we found that PTPRE can associate and inhibit the activation of KIT/D816V in a dose dependent manner, but the inhibition is much weaker compared with wild-type KIT. Similar to mastocytosis, KIT mutations are the main oncogenic mutations in gastrointestinal stromal tumors (GISTs) although GISTs carry different types of KIT mutations. We further studied the regulation of the activation of GISTs-type KIT mutants and other mastocytosis-type KIT mutants by PTPRE. Indeed, PTPRE can almost block the activation of GISTs-type KIT mutants, while the activation of mastocytosis-type KIT mutants is more resistant to the inhibition of PTPRE. Taken together, our results suggest that PTPRE can associate with KIT, and inhibit the activation of both wild-type KIT and GISTs-type KIT mutants, while the activation of mastocytosis-type KIT mutants is more resistant to PTPRE. PTPRE associates with wild-type KIT and KIT mutants. PTPRE inhibits the activation of both wild-type KIT and GISTs-type KIT mutants dramatically. The activation of mastocytosis-type KIT mutants are more resistant to the inhibition of PTPRE.
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Wu L, Yang Y, Li B, Huang W, Wang X, Liu X, Meng Z, Xia J. First Genome-wide Association Analysis for Growth Traits in the Largest Coral Reef-Dwelling Bony Fishes, the Giant Grouper (Epinephelus lanceolatus). MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2019; 21:707-717. [PMID: 31392592 DOI: 10.1007/s10126-019-09916-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 07/23/2019] [Indexed: 06/10/2023]
Abstract
The giant grouper, Epinephelus lanceolatus, is the largest coral reef-dwelling bony fish species. However, despite extremely fast growth performance and the considerable economic importance in this species, its genetic regulation of growth remains unknown. Here, we performed the first genome-wide association study (GWAS) for five growth traits in 289 giant groupers using 42,323 single nucleotide polymorphisms (SNPs) obtained by genotyping-by-sequencing (GBS). We identified a total of 36 growth-related SNPs, of which 11 SNPs reached a genome-wide significance level. The phenotypic variance explained by these SNPs varied from 7.09% for body height to 18.42% for body length. Moreover, 22 quantitative trait loci (QTLs) for growth traits, including nine significant QTLs and 13 suggestive QTLs, were found on multiple chromosomes. Interestingly, the QTL (LG17: 6934451) was shared between body weight and body height, while two significant QTLs (LG7: 22596399 and LG15: 11877836) for body length were consistent with the associated regions of total length at the genome-wide suggestive level. Eight potential candidate genes close to the associated SNPs were selected for expression analysis, of which four genes (phosphatidylinositol transfer protein cytoplasmic 1, protein tyrosine phosphatase receptor type E, alpha/beta hydrolase domain-containing protein 17C, and vascular endothelial growth factor A-A) were differentially expressed and involved in metabolism, development, response stress, etc. This study improves our understanding of the complex genetic architecture of growth in the giant grouper. The results contribute to the selective breeding of grouper species and the conservation of coral reef fishes.
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Affiliation(s)
- Lina Wu
- State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals, and the Guangdong Province Key Laboratory for Aquatic Economic Animals, Life Science School, Sun Yet-Sen University, Guangzhou, 510275, China
| | - Yang Yang
- State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals, and the Guangdong Province Key Laboratory for Aquatic Economic Animals, Life Science School, Sun Yet-Sen University, Guangzhou, 510275, China
| | - Bijun Li
- State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals, and the Guangdong Province Key Laboratory for Aquatic Economic Animals, Life Science School, Sun Yet-Sen University, Guangzhou, 510275, China
| | - Wenhua Huang
- State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals, and the Guangdong Province Key Laboratory for Aquatic Economic Animals, Life Science School, Sun Yet-Sen University, Guangzhou, 510275, China
| | - Xi Wang
- State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals, and the Guangdong Province Key Laboratory for Aquatic Economic Animals, Life Science School, Sun Yet-Sen University, Guangzhou, 510275, China
| | - Xiaochun Liu
- State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals, and the Guangdong Province Key Laboratory for Aquatic Economic Animals, Life Science School, Sun Yet-Sen University, Guangzhou, 510275, China
| | - Zining Meng
- State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals, and the Guangdong Province Key Laboratory for Aquatic Economic Animals, Life Science School, Sun Yet-Sen University, Guangzhou, 510275, China.
| | - Junhong Xia
- State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals, and the Guangdong Province Key Laboratory for Aquatic Economic Animals, Life Science School, Sun Yet-Sen University, Guangzhou, 510275, China
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Liang J, Shi J, Wang N, Zhao H, Sun J. Tuning the Protein Phosphorylation by Receptor Type Protein Tyrosine Phosphatase Epsilon (PTPRE) in Normal and Cancer Cells. J Cancer 2019; 10:105-111. [PMID: 30662530 PMCID: PMC6329871 DOI: 10.7150/jca.27633] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2018] [Accepted: 10/24/2018] [Indexed: 12/17/2022] Open
Abstract
Tyrosine phosphorylation is an important post-translation modification of proteins that is controlled by tyrosine kinases and phosphatases. Disruption of the balance between the activity of tyrosine kinases and phosphatases may result in diseases. Receptor type protein tyrosine phosphatase epsilon (PTPRE) is closely related with receptor type protein tyrosine phosphatase alpha (PTPRA). PTPRE has been studied in osteoclast cells, nerve cells, hematopoietic cells, cancer cells and others, and it has different functions among various tissues. In this review, we summarized the current knowledge about the regulation of PTPRE on cellular signal transduction and its function under normal and pathological conditions.
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Affiliation(s)
- Jinping Liang
- School of Basic Medical Sciences, Ningxia Medical University, Yinchuan, P.R.China.,Ningxia Key laboratory of Clinical and Pathogenic Microbiology, The General Hospital of Ningxia Medical University, Yinchuan, China
| | - Jun Shi
- School of Basic Medical Sciences, Ningxia Medical University, Yinchuan, P.R.China
| | - Na Wang
- School of Basic Medical Sciences, Ningxia Medical University, Yinchuan, P.R.China
| | - Hui Zhao
- School of Biomedical Science, Faculty of Medicine, the Chinese University of Hong Kong
| | - Jianmin Sun
- School of Basic Medical Sciences, Ningxia Medical University, Yinchuan, P.R.China.,Division of Translational Cancer Research, Lund Stem Cell Center, Department of Laboratory Medicine, Lund University, Lund, Sweden
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Davegårdh C, García-Calzón S, Bacos K, Ling C. DNA methylation in the pathogenesis of type 2 diabetes in humans. Mol Metab 2018; 14:12-25. [PMID: 29496428 PMCID: PMC6034041 DOI: 10.1016/j.molmet.2018.01.022] [Citation(s) in RCA: 112] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Revised: 01/29/2018] [Accepted: 01/29/2018] [Indexed: 02/08/2023] Open
Abstract
Background Type 2 diabetes (T2D) is a multifactorial, polygenic disease caused by impaired insulin secretion and insulin resistance. Genome-wide association studies (GWAS) were expected to resolve a large part of the genetic component of diabetes; yet, the single nucleotide polymorphisms identified by GWAS explain less than 20% of the estimated heritability for T2D. There was subsequently a need to look elsewhere to find disease-causing factors. Mechanisms mediating the interaction between environmental factors and the genome, such as epigenetics, may be of particular importance in the pathogenesis of T2D. Scope of Review This review summarizes knowledge of the impact of epigenetics on the pathogenesis of T2D in humans. In particular, the review will focus on alterations in DNA methylation in four human tissues of importance for the disease; pancreatic islets, skeletal muscle, adipose tissue, and the liver. Case–control studies and studies examining the impact of non-genetic and genetic risk factors on DNA methylation in humans will be considered. These studies identified epigenetic changes in tissues from subjects with T2D versus non-diabetic controls. They also demonstrate that non-genetic factors associated with T2D such as age, obesity, energy rich diets, physical activity and the intrauterine environment impact the epigenome in humans. Additionally, interactions between genetics and epigenetics seem to influence the pathogenesis of T2D. Conclusions Overall, previous studies by our group and others support a key role for epigenetics in the growing incidence of T2D.
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Affiliation(s)
- Cajsa Davegårdh
- Epigenetics and Diabetes, Lund University Diabetes Centre (LUDC), Box 50332, 20213 Malmö, Sweden.
| | - Sonia García-Calzón
- Epigenetics and Diabetes, Lund University Diabetes Centre (LUDC), Box 50332, 20213 Malmö, Sweden
| | - Karl Bacos
- Epigenetics and Diabetes, Lund University Diabetes Centre (LUDC), Box 50332, 20213 Malmö, Sweden
| | - Charlotte Ling
- Epigenetics and Diabetes, Lund University Diabetes Centre (LUDC), Box 50332, 20213 Malmö, Sweden
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Inter-Tissue Gene Co-Expression Networks between Metabolically Healthy and Unhealthy Obese Individuals. PLoS One 2016; 11:e0167519. [PMID: 27907186 PMCID: PMC5132173 DOI: 10.1371/journal.pone.0167519] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Accepted: 11/15/2016] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Obesity is associated with severe co-morbidities such as type 2 diabetes and nonalcoholic steatohepatitis. However, studies have shown that 10-25 percent of the severely obese individuals are metabolically healthy. To date, the identification of genetic factors underlying the metabolically healthy obese (MHO) state is limited. Systems genetics approaches have led to the identification of genes and pathways in complex diseases. Here, we have used such approaches across tissues to detect genes and pathways involved in obesity-induced disease development. METHODS Expression data of 60 severely obese individuals was accessible, of which 28 individuals were MHO and 32 were metabolically unhealthy obese (MUO). A whole genome expression profile of four tissues was available: liver, muscle, subcutaneous adipose tissue and visceral adipose tissue. Using insulin-related genes, we used the weighted gene co-expression network analysis (WGCNA) method to build within- and inter-tissue gene networks. We identified genes that were differentially connected between MHO and MUO individuals, which were further investigated by homing in on the modules they were active in. To identify potentially causal genes, we integrated genomic and transcriptomic data using an eQTL mapping approach. RESULTS Both IL-6 and IL1B were identified as highly differentially co-expressed genes across tissues between MHO and MUO individuals, showing their potential role in obesity-induced disease development. WGCNA showed that those genes were clustering together within tissues, and further analysis showed different co-expression patterns between MHO and MUO subnetworks. A potential causal role for metabolic differences under similar obesity state was detected for PTPRE, IL-6R and SLC6A5. CONCLUSIONS We used a novel integrative approach by integration of co-expression networks across tissues to elucidate genetic factors related to obesity-induced metabolic disease development. The identified genes and their interactions give more insight into the genetic architecture of obesity and the association with co-morbidities.
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Kim SS, Choi KM, Kim S, Park T, Cho IC, Lee JW, Lee CK. Whole-transcriptome analysis of mouse adipose tissue in response to short-term caloric restriction. Mol Genet Genomics 2016; 291:831-47. [PMID: 26606930 DOI: 10.1007/s00438-015-1150-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2015] [Accepted: 11/16/2015] [Indexed: 12/22/2022]
Abstract
Caloric restriction (CR) has been shown to extend the lifespan of many species by improving cellular function and organismal health. Additionally, fat reduction by CR may play an important role in lengthening lifespan and preventing severe age-related diseases. Interestingly, CR induced the greatest transcriptome change in the epididymal fat of mice in our study. In this transcriptome analysis, we identified and categorized 446 genes that correlated with CR level. We observed down-regulation of several signaling pathways, including insulin/insulin-like growth factor 1 (insulin/IGF-1), epidermal growth factor (EGF), transforming growth factor beta (TGF-β), and canonical wingless-type mouse mammary tumor virus integration site (Wnt). Many genes related to structural features, including extracellular matrix structure, cell adhesion, and the cytoskeleton, were down-regulated, with a strong correlation to the degree of CR. Furthermore, genes related to the cell cycle and adipogenesis were down-regulated. These biological processes are well-identified targets of insulin/IGF-1, EGF, TGF-β, and Wnt signaling. In contrast, genes involved in specific metabolic processes, including the tricarboxylic acid cycle and the electron transport chain were up-regulated. We performed in silico analysis of the promoter sequences of CR-responsive genes and identified two associated transcription factors, Paired-like homeodomain 2 (Pitx2) and Paired box gene 6 (Pax6). Our results suggest that strict regulation of signaling pathways is critical for creating the optimal energy homeostasis to extend lifespan.
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Affiliation(s)
- Seung-Soo Kim
- Department of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, 136-701, Republic of Korea
| | - Kyung-Mi Choi
- Department of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, 136-701, Republic of Korea
| | - Soyoung Kim
- Department of Food and Nutrition, Yonsei University, Seoul, 120-749, Republic of Korea
| | - Taesun Park
- Department of Food and Nutrition, Yonsei University, Seoul, 120-749, Republic of Korea
| | - In-Cheol Cho
- Subtropical Animal Station, National Institute of Animal Science, Jeju, 690-150, Republic of Korea
| | - Jae-Won Lee
- Department of Statistics, Korea University, Seoul, 136-701, Republic of Korea
| | - Cheol-Koo Lee
- Department of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, 136-701, Republic of Korea.
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Jamnikar U, Nikolic P, Belic A, Blas M, Gaser D, Francky A, Laux H, Blejec A, Baebler S, Gruden K. Transcriptome study and identification of potential marker genes related to the stable expression of recombinant proteins in CHO clones. BMC Biotechnol 2015; 15:98. [PMID: 26499110 PMCID: PMC4812793 DOI: 10.1186/s12896-015-0218-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2014] [Accepted: 10/19/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Chinese hamster ovary (CHO) cells have become the host of choice for the production of recombinant proteins, due to their capacity for correct protein folding, assembly, and posttranslational modifications. The most widely used system for recombinant proteins is the gene amplification procedure that uses the CHO-Dhfr expression system. However, CHO cells are known to have a very unstable karyotype. This is due to chromosome rearrangements that can arise from translocations and homologous recombination, especially when cells with the CHO-Dhfr expression system are treated with methotrexate hydrate. The present method used in the industry for testing clones for their long-term stability of recombinant protein production is empirical, and it involves their cultivation over extended periods of time prior to the selection of the most suitable clone for further bioprocess development. The aim of the present study was the identification of marker genes that can predict stable expression of recombinant genes in particular clones early in the development stage. RESULTS The transcriptome profiles of CHO clones with stable and unstable recombinant protein production were investigated over 10-weeks of cultivation, using a DNA microarray. We identified 14 genes that were differentially expressed between the stable and unstable clones already at 2 weeks from the beginning of the cultivation. Their expression was validated by reverse-transcription quantitative real-time PCR (RT-qPCR). Furthermore, the k-nearest neighbour algorithm approach shows that the combination of the gene expression patterns of only five of these 14 genes is sufficient to predict stable recombinant protein production in clones in the early phases of cell-line development. CONCLUSIONS The exact molecular mechanisms that cause unstable recombinant protein production are not fully understood. However, the expression profiles of some genes in clones with stable and unstable recombinant protein production allow prediction of such instability early in the cell-line development stage. We have thus developed a proof-of-concept for a novel approach to eliminate unstable clones in the CHO-Dhfr expression system, which saves time and labour-intensive work in cell-line development.
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Affiliation(s)
- Uros Jamnikar
- Sandoz Biopharmaceuticals, Kolodvorska 27, SI-1234, Menges, Slovenia.
| | - Petra Nikolic
- Jozef Stefan Institute, Jamova cesta 39, SI-1000, Ljubljana, Slovenia.
| | - Ales Belic
- Sandoz Biopharmaceuticals, Kolodvorska 27, SI-1234, Menges, Slovenia.
| | - Marjanca Blas
- Sandoz Biopharmaceuticals, Kolodvorska 27, SI-1234, Menges, Slovenia.
| | - Dominik Gaser
- Sandoz Biopharmaceuticals, Kolodvorska 27, SI-1234, Menges, Slovenia.
| | - Andrej Francky
- Sandoz Biopharmaceuticals, Kolodvorska 27, SI-1234, Menges, Slovenia.
| | - Holger Laux
- Novartis Pharma AG, WKL-681.1.08, 4002, Basel, Switzerland.
| | - Andrej Blejec
- National Institute of Biology, Vecna pot 111, SI-1000, Ljubljana, Slovenia.
| | - Spela Baebler
- National Institute of Biology, Vecna pot 111, SI-1000, Ljubljana, Slovenia.
| | - Kristina Gruden
- National Institute of Biology, Vecna pot 111, SI-1000, Ljubljana, Slovenia.
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Fan HQ, He W, Xu KF, Wang ZX, Xu XY, Chen H. FTO Inhibits Insulin Secretion and Promotes NF-κB Activation through Positively Regulating ROS Production in Pancreatic β cells. PLoS One 2015; 10:e0127705. [PMID: 26018652 PMCID: PMC4446323 DOI: 10.1371/journal.pone.0127705] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Accepted: 04/17/2015] [Indexed: 11/25/2022] Open
Abstract
FTO (Fat mass and obesity-associated) is associated with increased risk of obesity and type 2 diabetes incurrence. Pancreas islet β cells dysfunction and insulin resistance are major causes of type 2 diabetes. However, whether FTO plays an important functional role in pancreatic β cells as well as the related molecular mechanism is still unclear. In the present study, the tissue expression profile of FTO was firstly determined using quantitative PCR and western blot. FTO is widely expressed in various tissues and presented with relative high expression in pancreas tissue, especially in endocrine pancreas. FTO overexpression in MIN6 cells achieved by lentivirus delivery significantly inhibits insulin secretion in the presence of glucose stimulus as well as KCl. FTO silence has no effect on insulin secretion of MIN6 cells. However, FTO overexpression doesn’t affect the transcription of insulin gene. Furthermore, reactive oxygen species (ROS) production and NF-κB activation are significantly promoted by FTO overexpression. Inhibition of intracellular ROS production by N-acetyl-L-cysteine (NAC) can alleviate NF-κB activation and restore the insulin secretion mediated by FTO overexpression. A whole transcript-microarray is employed to analyze the differential gene expression mediated by FTO overexpression. The genes which are modulated by FTO are involved in many important biological pathways such as G-protein coupled receptor signaling and NF-κB signaling. Therefore, our study indicates that FTO may contribute to pancreas islet β cells dysfunction and the inhibition of FTO activity is a potential target for the treatment of diabetes.
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Affiliation(s)
- Hong-Qi Fan
- Department of Endocrinology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
- * E-mail:
| | - Wei He
- Department of Endocrinology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Kuan-Feng Xu
- Department of Endocrinology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Zhi-Xiao Wang
- Department of Endocrinology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Xin-Yu Xu
- Department of Endocrinology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Heng Chen
- Department of Endocrinology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
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Xu E, Schwab M, Marette A. Role of protein tyrosine phosphatases in the modulation of insulin signaling and their implication in the pathogenesis of obesity-linked insulin resistance. Rev Endocr Metab Disord 2014; 15:79-97. [PMID: 24264858 DOI: 10.1007/s11154-013-9282-4] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Insulin resistance is a major disorder that links obesity to type 2 diabetes mellitus (T2D). It involves defects in the insulin actions owing to a reduced ability of insulin to trigger key signaling pathways in major metabolic tissues. The pathogenesis of insulin resistance involves several inhibitory molecules that interfere with the tyrosine phosphorylation of the insulin receptor and its downstream effectors. Among those, growing interest has been developed toward the protein tyrosine phosphatases (PTPs), a large family of enzymes that can inactivate crucial signaling effectors in the insulin signaling cascade by dephosphorylating their tyrosine residues. Herein we briefly review the role of several PTPs that have been shown to be implicated in the regulation of insulin action, and then focus on the Src homology 2 (SH2) domain-containing SHP1 and SHP2 enzymes, since recent reports have indicated major roles for these PTPs in the control of insulin action and glucose metabolism. Finally, the therapeutic potential of targeting PTPs for combating insulin resistance and alleviating T2D will be discussed.
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Affiliation(s)
- Elaine Xu
- Department of Medicine, Cardiology Axis of the Institut Universitaire de Cardiologie et de Pneumologie de Québec (Hôpital Laval), Ste-Foy, Québec, Canada, G1V 4G2
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Knobler H, Elson A. Metabolic regulation by protein tyrosine phosphatases. J Biomed Res 2014; 28:157-68. [PMID: 25013399 PMCID: PMC4085553 DOI: 10.7555/jbr.28.20140012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Accepted: 01/28/2014] [Indexed: 01/14/2023] Open
Abstract
Obesity and the metabolic syndrome and their associated morbidities are major public health issues, whose prevalence will continue to increase in the foreseeable future. Aberrant signaling by the receptors for leptin and insulin plays a pivotal role in development of the metabolic syndrome. More complete molecular-level understanding of how both of these key signaling pathways are regulated is essential for full characterization of obesity, the metabolic syndrome, and type II diabetes, and for developing novel treatments for these diseases. Phosphorylation of proteins on tyrosine residues plays a key role in mediating the effects of leptin and insulin on their target cells. Here, we discuss the molecular methods by which protein tyrosine phosphatases, which are key physiological regulators of protein phosphorylation in vivo, affect signaling by the leptin and insulin receptors in their major target tissues.
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Affiliation(s)
- Hilla Knobler
- Diabetes and Metabolic Disease Unit, Kaplan Medical Center, Rehovot 76100, Israel
| | - Ari Elson
- Department of Molecular Genetics, the Weizmann Institute of Science, Rehovot 76100, Israel
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DNA methylation analysis in nonalcoholic fatty liver disease suggests distinct disease-specific and remodeling signatures after bariatric surgery. Cell Metab 2013; 18:296-302. [PMID: 23931760 DOI: 10.1016/j.cmet.2013.07.004] [Citation(s) in RCA: 373] [Impact Index Per Article: 33.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Revised: 05/12/2013] [Accepted: 07/12/2013] [Indexed: 12/11/2022]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disorder in industrialized countries. Liver samples from morbidly obese patients (n = 45) with all stages of NAFLD and controls (n = 18) were analyzed by array-based DNA methylation and mRNA expression profiling. NAFLD-specific expression and methylation differences were seen for nine genes coding for key enzymes in intermediate metabolism (including PC, ACLY, and PLCG1) and insulin/insulin-like signaling (including IGF1, IGFBP2, and PRKCE) and replicated by bisulfite pyrosequening (independent n = 39). Transcription factor binding sites at NAFLD-specific CpG sites were >1,000-fold enriched for ZNF274, PGC1A, and SREBP2. Intraindividual comparison of liver biopsies before and after bariatric surgery showed NAFLD-associated methylation changes to be partially reversible. Postbariatric and NAFLD-specific methylation signatures were clearly distinct both in gene ontology and transcription factor binding site analyses, with >400-fold enrichment of NRF1, HSF1, and ESRRA sites. Our findings provide an example of treatment-induced epigenetic organ remodeling in humans.
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Tsou RC, Bence KK. Central regulation of metabolism by protein tyrosine phosphatases. Front Neurosci 2013; 6:192. [PMID: 23308070 PMCID: PMC3538333 DOI: 10.3389/fnins.2012.00192] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Accepted: 12/17/2012] [Indexed: 11/13/2022] Open
Abstract
Protein tyrosine phosphatases (PTPs) are important regulators of intracellular signaling pathways via the dephosphorylation of phosphotyrosyl residues on various receptor and non-receptor substrates. The phosphorylation state of central nervous system (CNS) signaling components underlies the molecular mechanisms of a variety of physiological functions including the control of energy balance and glucose homeostasis. In this review, we summarize the current evidence implicating PTPs as central regulators of metabolism, specifically highlighting their interactions with the neuronal leptin and insulin signaling pathways. We discuss the role of a number of PTPs (PTP1B, SHP2, TCPTP, RPTPe, and PTEN), reviewing the findings from genetic mouse models and in vitro studies which highlight these phosphatases as key central regulators of energy homeostasis.
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Affiliation(s)
- Ryan C Tsou
- Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania Philadelphia, PA, USA
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Brutman-Barazani T, Horovitz-Fried M, Aga-Mizrachi S, Brand C, Brodie C, Rosa J, Sampson SR. Protein kinase Cδ but not PKCα is involved in insulin-induced glucose metabolism in hepatocytes. J Cell Biochem 2012; 113:2064-76. [DOI: 10.1002/jcb.24078] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Loh K, Merry TL, Galic S, Wu BJ, Watt MJ, Zhang S, Zhang ZY, Neel BG, Tiganis T. T cell protein tyrosine phosphatase (TCPTP) deficiency in muscle does not alter insulin signalling and glucose homeostasis in mice. Diabetologia 2012; 55:468-78. [PMID: 22124607 PMCID: PMC5057388 DOI: 10.1007/s00125-011-2386-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2011] [Accepted: 10/25/2011] [Indexed: 12/17/2022]
Abstract
AIMS/HYPOTHESIS Insulin activates insulin receptor protein tyrosine kinase and downstream phosphatidylinositol-3-kinase (PI3K)/Akt signalling in muscle to promote glucose uptake. The insulin receptor can serve as a substrate for the protein tyrosine phosphatase (PTP) 1B and T cell protein tyrosine phosphatase (TCPTP), which share a striking 74% sequence identity in their catalytic domains. PTP1B is a validated therapeutic target for the alleviation of insulin resistance in type 2 diabetes. PTP1B dephosphorylates the insulin receptor in liver and muscle to regulate glucose homeostasis, whereas TCPTP regulates insulin receptor signalling and gluconeogenesis in the liver. In this study we assessed for the first time the role of TCPTP in the regulation of insulin receptor signalling in muscle. METHODS We generated muscle-specific TCPTP-deficient (Mck-Cre;Ptpn2(lox/lox)) mice (Mck, also known as Ckm) and assessed the impact on glucose homeostasis and muscle insulin receptor signalling in chow-fed versus high-fat-fed mice. RESULTS Blood glucose and insulin levels, insulin and glucose tolerance, and insulin-induced muscle insulin receptor activation and downstream PI3K/Akt signalling remained unaltered in chow-fed Mck-Cre;Ptpn2(lox/lox) versus Ptpn2(lox/lox) mice. In addition, body weight, adiposity, energy expenditure, insulin sensitivity and glucose homeostasis were not altered in high-fat-fed Mck-Cre;Ptpn2(lox/lox) versus Ptpn2(lox/lox) mice. CONCLUSIONS/INTERPRETATION These results indicate that TCPTP deficiency in muscle has no effect on insulin signalling and glucose homeostasis, and does not prevent high-fat diet-induced insulin resistance. Thus, despite their high degree of sequence identity, PTP1B and TCPTP contribute differentially to insulin receptor regulation in muscle. Our results are consistent with the notion that these two highly related PTPs make distinct contributions to insulin receptor regulation in different tissues.
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Affiliation(s)
- Kim Loh
- Department of Biochemistry and Molecular Biology, Monash University, Victoria 3800, Australia
| | - Troy L. Merry
- Department of Biochemistry and Molecular Biology, Monash University, Victoria 3800, Australia
| | - Sandra Galic
- Department of Biochemistry and Molecular Biology, Monash University, Victoria 3800, Australia
| | - Ben J. Wu
- Department of Biochemistry and Molecular Biology, Monash University, Victoria 3800, Australia
| | - Matthew J. Watt
- Department of Physiology, Monash University, Victoria 3800, Australia
| | - Sheng Zhang
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Zhong-Yin Zhang
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Benjamin G. Neel
- Campbell Family Cancer Research Institute, Ontario Cancer Institute, Princess Margaret Hospital and Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
| | - Tony Tiganis
- Department of Biochemistry and Molecular Biology, Monash University, Victoria 3800, Australia
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Rousso-Noori L, Knobler H, Levy-Apter E, Kuperman Y, Neufeld-Cohen A, Keshet Y, Akepati VR, Klinghoffer RA, Chen A, Elson A. Protein tyrosine phosphatase epsilon affects body weight by downregulating leptin signaling in a phosphorylation-dependent manner. Cell Metab 2011; 13:562-72. [PMID: 21531338 DOI: 10.1016/j.cmet.2011.02.017] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2010] [Revised: 12/28/2010] [Accepted: 02/18/2011] [Indexed: 01/17/2023]
Abstract
Molecular-level understanding of body weight control is essential for combating obesity. We show that female mice lacking tyrosine phosphatase epsilon (RPTPe) are protected from weight gain induced by high-fat food, ovariectomy, or old age and exhibit increased whole-body energy expenditure and decreased adiposity. RPTPe-deficient mice, in particular males, exhibit improved glucose homeostasis. Female nonobese RPTPe-deficient mice are leptin hypersensitive and exhibit reduced circulating leptin concentrations, suggesting that RPTPe inhibits hypothalamic leptin signaling in vivo. Leptin hypersensitivity persists in aged, ovariectomized, and high-fat-fed RPTPe-deficient mice, indicating that RPTPe helps establish obesity-associated leptin resistance. RPTPe associates with and dephosphorylates JAK2, thereby downregulating leptin receptor signaling. Leptin stimulation induces phosphorylation of hypothalamic RPTPe at its C-terminal Y695, which drives RPTPe to downregulate JAK2. RPTPe is therefore an inhibitor of hypothalamic leptin signaling in vivo, and provides controlled negative-feedback regulation of this pathway following its activation.
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Affiliation(s)
- Liat Rousso-Noori
- Department of Molecular Genetics, The Weizmann Institute of Science, Rehovot, Israel
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Ngala RA, Stocker CJ, Roy AG, Hislop D, Wargent E, Bell R, Hassall DG, Harling JD, Billin AN, Willson TM, Arch JRS, Cawthorne MA. A new, highly selective murine peroxisome proliferator-activated receptor δ agonist increases responsiveness to thermogenic stimuli and glucose uptake in skeletal muscle in obese mice. Diabetes Obes Metab 2011; 13:455-64. [PMID: 21272187 DOI: 10.1111/j.1463-1326.2011.01371.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIM We investigated how GW800644, the first pharmacologically selective murine peroxisome proliferator-activated receptor δ (PPARδ) agonist, affects energy balance, glucose homeostasis and fuel utilization by muscle in obese mice. METHODS Potencies were determined in transactivation assays. Oral glucose tolerance was determined after 14 and 22 days' administration (10 mg/kg body weight, twice daily) to Lep(ob)/Lep(ob) mice. Food intake and energy expenditure were measured during a 26-day experiment, and plasma metabolites and 2-deoxyglucose uptake in vivo at termination. Palmitate oxidation and 2-deoxyglucose uptake by isolated soleus muscles were measured after 14 (in lean and obese mice) and 26 days. RESULTS GW800644 activated murine PPARδ (EC(50) 2 nM), but caused little to no activation of PPARα or PPARγ up to 10 µM. It did not increase liver weight. GW800644 reduced food intake and body weight in obese mice after 8 days. It did not affect resting energy expenditure, but, compared to pair-fed mice, it increased the response to a β(3)-adrenoceptor agonist. It improved glucose tolerance. GW800644, but not pair-feeding, reduced plasma glucose, insulin and triglyceride concentrations. It increased 2-deoxyglucose uptake in vivo in adipose tissue, soleus muscle, heart, brain and liver, and doubled 2-deoxyglucose uptake and palmitate oxidation in isolated soleus muscle from obese but not lean mice. CONCLUSIONS PPARδ agonism reduced food intake and independently elicited metabolic effects that included increased responsiveness to β(3)-adrenoceptor stimulation, increased glucose utilization and fat oxidation in soleus muscle of Lep(ob)/Lep(ob) but not lean mice and increased glucose utilization in vivo in Lep(ob)/Lep(ob) mice.
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Affiliation(s)
- R A Ngala
- Clore Laboratory, University of Buckingham, UK
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18
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Brand C, Horovitz-Fried M, Inbar A, Tamar-Brutman-Barazani, Brodie C, Sampson SR. Insulin stimulation of PKCδ triggers its rapid degradation via the ubiquitin-proteasome pathway. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2010; 1803:1265-75. [PMID: 20708645 DOI: 10.1016/j.bbamcr.2010.07.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2010] [Revised: 07/15/2010] [Accepted: 07/26/2010] [Indexed: 01/20/2023]
Abstract
Insulin rapidly upregulates protein levels of PKCδ in classical insulin target tissues skeletal muscle and liver. Insulin induces both a rapid increase in de novo synthesis of PKCδ protein. In this study we examined the possibility that insulin may also inhibit degradation of PKCδ. Experiments were performed on L6 skeletal muscle myoblasts or myotubes in culture. Phorbol ester (PMA)- and insulin-induced degradation of PKCδ were abrogated by proteasome inhibition. Both PMA and insulin induced ubiquitination of PKCδ, but not of that PKCα or PKCε and increased proteasome activity within 5 min. We examined the role of tyrosine phosphorylation of PKCδ in targeting PKCδ for degradation by the ubiquitin-proteasome pathway. Transfection of cells with PKCδY(311)F, which is not phosphorylated, resulted in abolition of insulin-induced ubiquitination of PKCδ and increase in proteasome activity. We conclude that insulin induces degradation of PKCδ via the ubiquitin-proteasome system, and that this effect requires phosphorylation on specific tyrosine residues for targeting PKCδ for degradation by the ubiquitin-proteasome pathway. These studies provide additional evidence for unique effects of insulin on regulation of PKCδ protein levels.
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Affiliation(s)
- Chagit Brand
- The Faculty of Life Science, Bar-Ilan University, Ramat-Gan, Israel
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Akimoto M, Mishra K, Lim KT, Tani N, Hisanaga SI, Katagiri T, Elson A, Mizuno K, Yakura H. Protein Tyrosine Phosphatase ε is a Negative Regulator of FcεRI-mediated Mast Cell Responses. Scand J Immunol 2009; 69:401-11. [DOI: 10.1111/j.1365-3083.2009.02235.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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Vafiadaki E, Arvanitis DA, Pagakis SN, Papalouka V, Sanoudou D, Kontrogianni-Konstantopoulos A, Kranias EG. The anti-apoptotic protein HAX-1 interacts with SERCA2 and regulates its protein levels to promote cell survival. Mol Biol Cell 2008; 20:306-18. [PMID: 18971376 DOI: 10.1091/mbc.e08-06-0587] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Cardiac contractility is regulated through the activity of various key Ca(2+)-handling proteins. The sarco(endo)plasmic reticulum (SR) Ca(2+) transport ATPase (SERCA2a) and its inhibitor phospholamban (PLN) control the uptake of Ca(2+) by SR membranes during relaxation. Recently, the antiapoptotic HS-1-associated protein X-1 (HAX-1) was identified as a binding partner of PLN, and this interaction was postulated to regulate cell apoptosis. In the current study, we determined that HAX-1 can also bind to SERCA2. Deletion mapping analysis demonstrated that amino acid residues 575-594 of SERCA2's nucleotide binding domain are required for its interaction with the C-terminal domain of HAX-1, containing amino acids 203-245. In transiently cotransfected human embryonic kidney 293 cells, recombinant SERCA2 was specifically targeted to the ER, whereas HAX-1 selectively concentrated at mitochondria. On triple transfections with PLN, however, HAX-1 massively translocated to the ER membranes, where it codistributed with PLN and SERCA2. Overexpression of SERCA2 abrogated the protective effects of HAX-1 on cell survival, after hypoxia/reoxygenation or thapsigargin treatment. Importantly, HAX-1 overexpression was associated with down-regulation of SERCA2 expression levels, resulting in significant reduction of apparent ER Ca(2+) levels. These findings suggest that HAX-1 may promote cell survival through modulation of SERCA2 protein levels and thus ER Ca(2+) stores.
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Affiliation(s)
- Elizabeth Vafiadaki
- Molecular Biology Division, Biomedical Research Foundation, Academy of Athens, Greece
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