DOCSLIB.ORG

11Β-Hydroxysteroid Dehydrogenase Type 1 Regulates Glucocorticoid-Induced Insulin Resistance in Skeletal Muscle

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
11Β-Hydroxysteroid Dehydrogenase Type 1 Regulates Glucocorticoid-Induced Insulin Resistance in Skeletal Muscle Diabetes Publish Ahead of Print, published online August 12, 2009 11β-HSD1 and skeletal muscle 11β-hydroxysteroid dehydrogenase type 1 regulates glucocorticoid-induced insulin resistance in skeletal muscle Stuart A Morgan1, Mark Sherlock1, Laura L Gathercole1, Gareth G Lavery1, Carol Lenaghan3, Iwona J Bujalska1, David Laber3, Alice Yu3, Gemma Convey3, Rachel Mayers3, Krisztina Hegyi2, Jaswinder K Sethi2, Paul M Stewart1, David M Smith3 and Jeremy W Tomlinson1 1. Centre for Endocrinology, Diabetes and Metabolism, Institute of Biomedical Research, School of Clinical & Experimental Medicine, University of Birmingham, Birmingham, UK. B15 2TT 2. Department of Clinical Biochemistry, University of Cambridge Metabolic Research Laboratories, Institute of Metabolic Science, Addenbrooke’s Hospital, Cambridge, CB2 0QQ 3. AstraZeneca Diabetes & Obesity Drug Discovery, Mereside, Alderley Park, Macclesfield, Cheshire, UK. SK10 4TG Brief title: 11β-HSD1 and skeletal muscle Address for correspondence: Jeremy W Tomlinson PhD MRCP E-mail. [email protected] Submitted 9 April 2009 and accepted 16 July 2009. This is an uncopyedited electronic version of an article accepted for publication in Diabetes. The American Diabetes Association, publisher of Diabetes, is not responsible for any errors or omissions in this version of the manuscript or any version derived from it by third parties. The definitive publisher-authenticated version will be available in a future issue of Diabetes in print and online at http://diabetes.diabetesjournals.org. Copyright American Diabetes Association, Inc., 2009 11β-HSD1 and skeletal muscle Objective: Glucocorticoid (GC) excess is characterized by increased adiposity, skeletal myopathy and insulin resistance, but the precise molecular mechanisms are unknown. Within skeletal muscle, 11β-hydroxysteroid dehydrogenase type 1 (11βHSD1) converts cortisone (11- dehydrocorticosterone, 11DHC in rodents) to active cortisol (corticosterone in rodents). We aimed to determine the mechanisms underpinning GC-induced insulin resistance in skeletal muscle and indentify how 11βHSD1 inhibitors improve insulin sensitivity. Research Design and Methods: Rodent and human cell cultures, whole tissue explants and animal models were used to determine the impact of GCs and selective 11β-HSD1 inhibition upon insulin signalling and action. Results: Dexamethasone (Dex), decreased insulin-stimulated glucose uptake, decreased IRS1 mRNA and protein expression and increased inactivating pSer307 IRS1. 11β-HSD1 activity and expression were observed in human and rodent myotubes and muscle explants. Activity was predominantly oxo-reductase, generating active GC. A1 (selective 11β-HSD1 inhibitor) abolished enzyme activity and blocked the increase in pSer307 IRS1 and reduction in total IRS1 protein following treatment with 11DHC, but not corticosterone. In C57Bl6/J mice, the selective 11β-HSD1 inhibitor, A2, decreased fasting blood glucose levels and improved insulin sensitivity. In KK mice treated with A2, skeletal muscle pSer307 IRS1 decreased and pTh308 Akt/PKB increased. In addition, A2 decreased both lipogenic and lipolytic gene expression. Conclusion: Pre-receptor facilitation of GC action via 11β-HSD1 increases pSer307 IRS1 and may be crucial in mediating insulin resistance in skeletal muscle. Selective 11β-HSD1 inhibition decreases pSer307 IRS1, increases pTh308 Akt/PKB and decreases lipogenic and lipolytic gene expression which may represent an important mechanism underpinning their insulin sensitizing action. 2 11β-HSD1 and skeletal muscle he pathophysiological effects intracellular domain of the receptor and are of glucocorticoids (GC) are phosphorylated at multiple tyrosine residues T well described and impact upon by the receptor-tyrosine kinase to permit the almost all organ systems within the body. docking of phosphatidylinositol-3-kinase This is highlighted in patients with GC (PI3K) and subsequent generation of excess, Cushing’s syndrome characterised by PI(3,4,5)P3. Generation of this second central obesity, hypertension, proximal messenger acts to recruit the Akt/PKB family myopathy, insulin resistance and in some of serine/theonine kinases to the plasma cases overt type 2 diabetes (T2DM). In membrane which are then activated (6). addition, up to 2.5% of the population are Further downstream, activated Akt1/PKB taking prescribed GCs (1), and their side phosphorylates a rab-GAP (GTPase) protein, effects represent a considerable clinical AS160, which is crucial regulator of the burden for both patient and clinician. translocation of GLUT4 glucose transporter GCs induce whole body insulin storage vesicles to the plasma membrane (7) resistance (2), however the precise molecular and it is this mechanism that permits insulin- mechanism that underpin this observation stimulated glucose entry into target tissues have not been defined in detail. In simple including skeletal muscle (8). obesity and insulin resistance, circulating The molecular mechanisms cortisol levels are not elevated (3), but in key underpinning insulin resistance are complex insulin target tissues including liver, fat and and variable. Serine/threonine muscle, GC availability to bind and activate phosphorylation of IRS1 (in particular serine- the GC receptor (GR) is controlled by 11β- 307 phosphorylation) has been shown to hydroxysteroid dehydrogenase type 1 (11β- negatively regulate insulin signalling through HSD1). 11β-HSD1 is an endo-lumenal multiple mechanisms including decreased enzyme that inter-converts inactive (cortisone affinity for the insulin receptor and increased in humans and 11-dehydrocorticosterone degradation (9;10). (11DHC) in rodents) and active GCs (cortisol The interaction of GC and the insulin in humans and corticosterone (CORT) in signalling cascade has only been examined in rodents) (4). Critically, the directionality of a small number of studies which have offered 11β-HSD1 activity is cofactor (NADPH) variable explanations for the induction of dependent which is supplied by a tightly insulin resistance (11-14). Importantly, the associated endo-lumenal enzyme, Hexose-6- role of serine phosphorylation and the impact phopshate dehydrogenase (H6PDH). of pre-receptor GC metabolism have not been Decreases in H6PDH expression and activity explored. The 11β-HSD1 knockout mouse is decrease 11β-HSD1 oxo-reductase and relatively insulin sensitive (15) and specific increase dehydrogenase activity (5). Despite inhibitors of 11β-HSD1 improve lipid this bidirectional potential, the predominant profiles, glucose tolerance and insulin direction of activity in liver, adipose and sensitivity and have considerable potential as muscle is oxo-reductase generating active GC therapeutic agents (16-18). However the (cortisol and CORT) therefore amplifying molecular mechanisms that underpin these local GC action. observations remain to be defined. Binding of insulin to its cell surface We have therefore characterized the receptor leads to a conformational change and impact of GCs upon the insulin signalling tyrosine autophosphorylation. Consequently, cascade and analyzed the expression, activity the insulin receptor substrate (IRS) family of adaptor proteins are recruited to the 3 11β-HSD1 and skeletal muscle and functional impact of 11β-HSD1 in vitro provided through material transfer agreements and using in vivo mouse models with AstraZeneca (Macclesfield, UK). Inhibitor properties are presented within the RESEARCH DESIGN AND METHODS: results section. Cell culture. Mouse skeletal muscle RNA extraction, RT and Real-Time cell line, C2C12 myoblasts (ECACC, UK) PCR. Total RNA was extracted from cell were grown in DMEM (PAA, UK) lysates using the Tri-Reagent system and supplemented with 10% FBS (37°C, 5% from whole tissue explants using RNeasy CO2). Cells were grown to 60-70% Fibrous Tissue Mini Kit (Qiagen). Integrity, confluence before differentiation (initiated by concentration and reverse transcription were replacing growth media with DMEM with 5% performed as we have previously described horse serum). After 8 days, myoblasts had (20). Specific mRNA levels were determined fused to form multinucleated myotubes. Prior using an ABI 7500 sequence detection system to treatment, cells were washed out with (Perkin-Elmer Applied Biosystems, serum free media for 4 hours. For Warrington, UK). Reactions were performed experiments examining serine-24 in 20µl volumes on 96-well plates in reaction phosphorylation, C2C12 cells stably over- buffer containing 2 x TaqMan Universal PCR expressing myc-rIRS1 were generated and Master mix (Applied Biosystems, Foster City, used as described previously for 3T3-L1 CA, USA). Probes and primers for all genes adipocytes (19). were supplied by applied biosystems ‘assay Primary human myoblasts were on demand’ (Applied Biosystems). All obtained from PromoCell (Heidelberg, reactions were normalised against 18S rRNA Germany). Myoblasts were cultured to as an internal house keeping gene. confluence, as per the manufactures Data were obtained as ct values (ct=cycle guidelines using the supplied media. Once number at which logarithmic PCR plots cross confluent, media was changed to a chemically a calculated threshold line) and used to defined media (PromoCell, Germany) determine ∆ct values (∆ct = (ct of the target including 2% horse serum and cells gene) – (ct of the housekeeping gene). Data differentiated into myotubes for 11 days. are expressed as arbitrary units using the Following differentiation, cells were following transformation [expression
Load more

Recommended publications
  • AMPK Exerts Dual Regulatory Effects on the PI3K Pathway Rong Tao1, Jun Gong2, Xixi Luo3, Mengwei Zang4, Wen Guo4, Rong Wen5, Zhijun Luo2,4*
    Tao et al. Journal of Molecular Signaling 2010, 5:1 http://www.jmolecularsignaling.com/content/5/1/1 RESEARCH ARTICLE Open Access AMPK exerts dual regulatory effects on the PI3K pathway Rong Tao1, Jun Gong2, Xixi Luo3, Mengwei Zang4, Wen Guo4, Rong Wen5, Zhijun Luo2,4* Abstract Background: AMP-activated protein kinase (AMPK) is a fuel-sensing enzyme that is activated when cells experience energy deficiency and conversely suppressed in surfeit of energy supply. AMPK activation improves insulin sensitivity via multiple mechanisms, among which AMPK suppresses mTOR/S6K-mediated negative feedback regulation of insulin signaling. Results: In the present study we further investigated the mechanism of AMPK-regulated insulin signaling. Our results showed that 5-aminoimidazole-4-carboxamide-1 ribonucleoside (AICAR) greatly enhanced the ability of insulin to stimulate the insulin receptor substrate-1 (IRS1)-associated PI3K activity in differentiated 3T3-F442a adipocytes, leading to increased Akt phosphorylation at S473, whereas insulin-stimulated activation of mTOR was diminished. In 3T3-F442a preadipocytes, these effects were attenuated by expression of a dominant negative mutant of AMPK a1 subunit. The enhancing effect of ACIAR on Akt phosphorylation was also observed when the cells were treated with EGF, suggesting that it is regulated at a step beyond IR/IRS1. Indeed, when the cells were chronically treated with AICAR in the absence of insulin, Akt phosphorylation was progressively increased. This event was associated with an increase in levels of phosphatidylinositol -3,4,5-trisphosphate (PIP3) and blocked by Wortmannin. We then expressed the dominant negative mutant of PTEN (C124S) and found that the inhibition of endogenous PTEN per se did not affect phosphorylation of Akt at basal levels or upon treatment with AICAR or insulin.
    [Show full text]
  • A Computational Approach for Defining a Signature of Β-Cell Golgi Stress in Diabetes Mellitus
    Page 1 of 781 Diabetes A Computational Approach for Defining a Signature of β-Cell Golgi Stress in Diabetes Mellitus Robert N. Bone1,6,7, Olufunmilola Oyebamiji2, Sayali Talware2, Sharmila Selvaraj2, Preethi Krishnan3,6, Farooq Syed1,6,7, Huanmei Wu2, Carmella Evans-Molina 1,3,4,5,6,7,8* Departments of 1Pediatrics, 3Medicine, 4Anatomy, Cell Biology & Physiology, 5Biochemistry & Molecular Biology, the 6Center for Diabetes & Metabolic Diseases, and the 7Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN 46202; 2Department of BioHealth Informatics, Indiana University-Purdue University Indianapolis, Indianapolis, IN, 46202; 8Roudebush VA Medical Center, Indianapolis, IN 46202. *Corresponding Author(s): Carmella Evans-Molina, MD, PhD ([email protected]) Indiana University School of Medicine, 635 Barnhill Drive, MS 2031A, Indianapolis, IN 46202, Telephone: (317) 274-4145, Fax (317) 274-4107 Running Title: Golgi Stress Response in Diabetes Word Count: 4358 Number of Figures: 6 Keywords: Golgi apparatus stress, Islets, β cell, Type 1 diabetes, Type 2 diabetes 1 Diabetes Publish Ahead of Print, published online August 20, 2020 Diabetes Page 2 of 781 ABSTRACT The Golgi apparatus (GA) is an important site of insulin processing and granule maturation, but whether GA organelle dysfunction and GA stress are present in the diabetic β-cell has not been tested. We utilized an informatics-based approach to develop a transcriptional signature of β-cell GA stress using existing RNA sequencing and microarray datasets generated using human islets from donors with diabetes and islets where type 1(T1D) and type 2 diabetes (T2D) had been modeled ex vivo. To narrow our results to GA-specific genes, we applied a filter set of 1,030 genes accepted as GA associated.
    [Show full text]
  • Inhibition of Insulin Receptor Gene Expression and Insulin Signaling by Fatty Acid: Interplay of PKC Isoforms Therein
    Original Paper Cellular Physiology Cell Physiol Biochem 2005;16:217-228 Accepted: July 27, 2005 and Biochemistry Inhibition of Insulin Receptor Gene Expression and Insulin Signaling by Fatty Acid: Interplay of PKC Isoforms Therein Debleena Dey, Mohua Mukherjee, Dipanjan Basu1, Malabika Datta, Sib Sankar Roy, Arun Bandyopadhyay and Samir Bhattacharya1 Molecular Endocrinology Laboratory, Indian Institute of Chemical Biology, 4, Raja S. C. Mullick Road, Kolkata, 1Cellular and Molecular Endocrinology Laboratory, Department of Zoology, School of Life Science, Visva-Bharati University, Santiniketan Key Words dependent, palmitate effected its constitutive Insulin resistance • Type 2 diabetes • Insulin receptor phosphorylation independent of PDK1. Time kinetics • Insulin signaling • PKC isoforms • Free fatty acids • study showed translocation of palmitate induced HMG phosphorylated PKCε from cell membrane to nuclear region and its possible association with the inhibition Abstract of IR gene transcription. Our study suggests one of Fatty acids are known to play a key role in promoting the pathways through which fatty acid can induce the loss of insulin sensitivity causing insulin resistance insulin resistance in skeletal muscle cell. and type 2 diabetes. However, underlying mechanism involved here is still unclear. Incubation of rat skeletal muscle cells with palmitate followed by I125- insulin Copyright © 2005 S. Karger AG, Basel binding to the plasma membrane receptor preparation demonstrated a two-fold decrease in receptor occupation. In searching the cause for this reduction, Introduction we found that palmitate inhibition of insulin receptor (IR) gene expression effecting reduced amount of IR Insulin resistance and type 2 diabetes mellitus is an protein in skeletal muscle cells. This was followed by insidious disease that accounts for more than 95% of the inhibition of insulin-stimulated IRβ tyrosine diabetic cases.
    [Show full text]
  • PTPN11 Is the First Identified Proto-Oncogene That Encodes a Tyrosine Phosphatase
    From www.bloodjournal.org by guest on July 4, 2016. For personal use only. Review article PTPN11 is the first identified proto-oncogene that encodes a tyrosine phosphatase Rebecca J. Chan1 and Gen-Sheng Feng2,3 1Department of Pediatrics, the Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis; 2Programs in Signal Transduction and Stem Cells & Regeneration, Burnham Institute for Medical Research, La Jolla, CA; 3Institute for Biomedical Research, Xiamen University, Xiamen, China Elucidation of the molecular mechanisms 2 Src-homology 2 (SH2) domains (Shp2). vation of the Ras-Erk pathway. This underlying carcinogenesis has benefited This tyrosine phosphatase was previ- progress represents another milestone in tremendously from the identification and ously shown to play an essential role in the leukemia/cancer research field and characterization of oncogenes and tumor normal hematopoiesis. More recently, so- provides a fresh view on the molecular suppressor genes. One new advance in matic missense PTPN11 gain-of-function mechanisms underlying cell transforma- this field is the identification of PTPN11 mutations have been detected in leuke- tion. (Blood. 2007;109:862-867) as the first proto-oncogene that encodes mias and rarely in solid tumors, and have a cytoplasmic tyrosine phosphatase with been found to induce aberrant hyperacti- © 2007 by The American Society of Hematology Introduction Leukemia and other types of cancer continue to be a leading cause tumor suppressor activity when overexpressed in vitro, and Ptprj of death in the United States, and biomedical scientists sorely note maps to the mouse colon cancer susceptibility locus,3 implicating that victories against cancer remain unacceptably rare.
    [Show full text]
  • TBC1D1 Regulates Insulin- and Contraction-Induced Glucose Transport in Mouse Skeletal Muscle Ding An,1 Taro Toyoda,1 Eric B
    ORIGINAL ARTICLE TBC1D1 Regulates Insulin- and Contraction-Induced Glucose Transport in Mouse Skeletal Muscle Ding An,1 Taro Toyoda,1 Eric B. Taylor,1 Haiyan Yu,1 Nobuharu Fujii,1 Michael F. Hirshman,1 and Laurie J. Goodyear1,2 OBJECTIVE—TBC1D1 is a member of the TBC1 Rab-GTPase through a phosphatidylinositol 3 kinase (PI 3-kinase)– family of proteins and is highly expressed in skeletal muscle. dependent mechanism and the exercise effect may involve Insulin and contraction increase TBC1D1 phosphorylation on multiple molecules including the AMP-activated protein phospho-Akt substrate motifs (PASs), but the function of kinase (AMPK) family of protein kinases, an important TBC1D1 in muscle is not known. Genetic linkage analyses show goal in this field has been to elucidate the mechanisms that a TBC1D1 R125W missense variant confers risk for severe connect the proximal insulin and exercise signals to obesity in humans. The objective of this study was to determine whether TBC1D1 regulates glucose transport in skeletal muscle. GLUT4 translocation. Recent studies have identified two molecules, the Akt substrate of 160 kDa (AS160/TBC1D4) RESEARCH DESIGN AND METHODS—In vivo gene injection and its paralog, TBC1D1, as potential molecular links and electroporation were used to overexpress wild-type and among multiple signaling pathways converging on GLUT4 several mutant TBC1D1 proteins in mouse tibialis anterior mus- translocation in skeletal muscle (5–12). cles, and glucose transport was measured in vivo. AS160 was first shown to modulate GLUT4 trafficking in RESULTS—Expression of the obesity-associated R125W mutant insulin-sensitive 3T3-L1 adipocytes (13). A striking struc- significantly decreased insulin-stimulated glucose transport in tural feature of AS160 is that the molecule harbors a the absence of changes in TBC1D1 PAS phosphorylation.
    [Show full text]
  • Synthetic Mrnas; Their Analogue Caps and Contribution to Disease
    diseases Review Synthetic mRNAs; Their Analogue Caps and Contribution to Disease Anthony M. Kyriakopoulos 1,* and Peter A. McCullough 2 1 Nasco AD Biotechnology Laboratory, Sachtouti 11, 18536 Piraeus, Greece 2 Department of Internal Medicine, Division of Cardiology, Baylor University Medical Center, Dallas, TX 75246, USA; [email protected] * Correspondence: [email protected]; Tel.: +30-6944415602 Abstract: The structure of synthetic mRNAs as used in vaccination against cancer and infectious diseases contain specifically designed caps followed by sequences of the 50 untranslated repeats of b-globin gene. The strategy for successful design of synthetic mRNAs by chemically modifying their caps aims to increase resistance to the enzymatic deccapping complex, offer a higher affinity for binding to the eukaryotic translation initiation factor 4E (elF4E) protein and enforce increased translation of their encoded proteins. However, the cellular homeostasis is finely balanced and obeys to specific laws of thermodynamics conferring balance between complexity and growth rate in evolution. An overwhelm- ing and forced translation even under alarming conditions of the cell during a concurrent viral infection, or when molecular pathways are trying to circumvent precursor events that lead to autoimmunity and cancer, may cause the recipient cells to ignore their differential sensitivities which are essential for keeping normal conditions. The elF4E which is a powerful RNA regulon and a potent oncogene governing cell cycle progression and proliferation at a post-transcriptional level, may then be a great contributor to disease development. The mechanistic target of rapamycin (mTOR) axis manly inhibits the elF4E to proceed with mRNA translation but disturbance in fine balances between mTOR and elF4E Citation: Kyriakopoulos, A.M.; action may provide a premature step towards oncogenesis, ignite pre-causal mechanisms of immune McCullough, P.A.
    [Show full text]
  • Transcriptomic Landscape of Early Age Onset of Colorectal Cancer Identifies
    www.nature.com/scientificreports OPEN Transcriptomic landscape of early age onset of colorectal cancer identifes novel genes and pathways in Indian CRC patients Manish Pratap Singh, Sandhya Rai, Nand K. Singh & Sameer Srivastava* Past decades of the current millennium have witnessed an unprecedented rise in Early age Onset of Colo Rectal Cancer (EOCRC) cases in India as well as across the globe. Unfortunately, EOCRCs are diagnosed at a more advanced stage of cancer. Moreover, the aetiology of EOCRC is not fully explored and still remains obscure. This study is aimed towards the identifcation of genes and pathways implicated in the EOCRC. In the present study, we performed high throughput RNA sequencing of colorectal tumor tissues for four EOCRC (median age 43.5 years) samples with adjacent mucosa and performed subsequent bioinformatics analysis to identify novel deregulated pathways and genes. Our integrated analysis identifes 17 hub genes (INSR, TNS1, IL1RAP, CD22, FCRLA, CXCL3, HGF, MS4A1, CD79B, CXCR2, IL1A, PTPN11, IRS1, IL1B, MET, TCL1A, and IL1R1). Pathway analysis of identifed genes revealed that they were involved in the MAPK signaling pathway, hematopoietic cell lineage, cytokine–cytokine receptor pathway and PI3K-Akt signaling pathway. Survival and stage plot analysis identifed four genes CXCL3, IL1B, MET and TNS1 genes (p = 0.015, 0.038, 0.049 and 0.011 respectively), signifcantly associated with overall survival. Further, diferential expression of TNS1 and MET were confrmed on the validation cohort of the 5 EOCRCs (median age < 50 years and sporadic origin). This is the frst approach to fnd early age onset biomarkers in Indian CRC patients.
    [Show full text]
  • Anaplastic Lymphoma Kinase (ALK): Structure, Oncogenic Activation, and Pharmacological Inhibition
    Pharmacological Research 68 (2013) 68–94 Contents lists available at SciVerse ScienceDirect Pharmacological Research jo urnal homepage: www.elsevier.com/locate/yphrs Invited review Anaplastic lymphoma kinase (ALK): Structure, oncogenic activation, and pharmacological inhibition ∗ Robert Roskoski Jr. Blue Ridge Institute for Medical Research, 3754 Brevard Road, Suite 116, Box 19, Horse Shoe, NC 28742, USA a r t i c l e i n f o a b s t r a c t Article history: Anaplastic lymphoma kinase was first described in 1994 as the NPM-ALK fusion protein that is expressed Received 14 November 2012 in the majority of anaplastic large-cell lymphomas. ALK is a receptor protein-tyrosine kinase that was Accepted 18 November 2012 more fully characterized in 1997. Physiological ALK participates in embryonic nervous system develop- ment, but its expression decreases after birth. ALK is a member of the insulin receptor superfamily and Keywords: is most closely related to leukocyte tyrosine kinase (Ltk), which is a receptor protein-tyrosine kinase. Crizotinib Twenty different ALK-fusion proteins have been described that result from various chromosomal rear- Drug discovery rangements, and they have been implicated in the pathogenesis of several diseases including anaplastic Non-small cell lung cancer large-cell lymphoma, diffuse large B-cell lymphoma, and inflammatory myofibroblastic tumors. The Protein kinase inhibitor EML4-ALK fusion protein and four other ALK-fusion proteins play a fundamental role in the development Targeted cancer therapy Acquired drug resistance in about 5% of non-small cell lung cancers. The formation of dimers by the amino-terminal portion of the ALK fusion proteins results in the activation of the ALK protein kinase domain that plays a key role in the tumorigenic process.
    [Show full text]
  • Microrna-128 Suppresses Cell Growth and Metastasis in Colorectal Carcinoma by Targeting IRS1
    ONCOLOGY REPORTS 34: 2797-2805, 2015 MicroRNA-128 suppresses cell growth and metastasis in colorectal carcinoma by targeting IRS1 LAN WU1, BO SHI2, KEXIN HUANG2 and GUOYU FAN3 1Department of Pediatrics, The First Hospital of Jilin University, and 2The Experiment Center, College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130021; 3Department of Oncology, The Center Hospital of Jilin City, Fengman, Jilin 132011, P.R. China Received June 29, 2015; Accepted August 3, 2015 DOI: 10.3892/or.2015.4251 Abstract. Evidence has shown that microRNAs play impor- cancer-associated mortality (1). Over one million new cases tant roles in tumor development, progression, and metastasis. are detected annually according to the International Agency miR-128 has been reported to be deregulated in different for Research on Cancer (2). Colorectal cancer is caused by tumor types, whereas the function of miR-128 in colorectal the accumulation of mutations in numerous genes, including carcinoma (CRC) largely remains to be elucidated. The aim of alterations in oncogenes and tumor-suppressor genes, which the present study was to investigate the clinical significance, lead to the activation of oncogenes and the inactivation of biological effects and underlying mechanisms of miR-128 in tumor-suppressor genes (3). Although previous studies have CRC using reverse transcription-quantitative polymerase chain focused on the biological mechanism of colorectal carci- reaction (RT-qPCR) and western blotting. It was found that noma (CRC) and a series of tumor-suppressor genes and the expression of miR-128 was downregulated in CRC tissues oncogenes have been identified in recent years, the patho- and cell lines as determined by RT-qPCR.
    [Show full text]
  • Glycogen Synthase Kinase 3B Mediates High Glucose-Induced Ubiquitination and Proteasome Degradation of Insulin Receptor Substrate 1
    171 Glycogen synthase kinase 3b mediates high glucose-induced ubiquitination and proteasome degradation of insulin receptor substrate 1 Sanhua Leng, Wenshuo Zhang, Yanbin Zheng, Ziva Liberman1, Christopher J Rhodes, Hagit Eldar-Finkelman1 and Xiao Jian Sun The Section of Endocrinology, The University of Chicago, KCBD Room 8122, 900 East 57th Street, Chicago, Illinois 60637, USA 1The Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel (Correspondence should be addressed to X J Sun; Email: [email protected]) (S Leng is now at New York College of Health Professions, Syosset, New York 11791, USA) Abstract High glucose (HG) has been shown to induce insulin resistance IRS1, HG-induced degradation of IRS1 did not require IR in both type 1 and type 2 diabetes. However, the molecular signaling or phosphatidylinositol 3-kinase/Akt activity. We have mechanism behind this phenomenon is unknown. Insulin identified glycogen synthase kinase 3b (GSK3b or GSK3B as receptor substrate (IRS) proteins are the key signaling molecules listed in the MGI Database) as a kinase required for HG-induced that mediate insulin’sintracellular actions. Genetic and biological serine332 phosphorylation, ubiquitination, and degradation of studies have shown that reductions in IRS1 and/or IRS2 protein IRS1. Overexpression of IRS1 with mutation of serine332 to levels are associated with insulin resistance. In this study we have alanine partially prevents HG-induced IRS1 degradation. shown that proteasome degradation of IRS1, but not of IRS2, is Furthermore, overexpression of constitutively active GSK3b involved in HG-induced insulin resistance in Chinese hamster was sufficient to induce IRS1 degradation.
    [Show full text]
  • TBC1D1 (V796) Antibody A
    Revision 1 C 0 2 - t TBC1D1 (V796) Antibody a e r o t S Orders: 877-616-CELL (2355) [email protected] Support: 877-678-TECH (8324) 9 2 Web: [email protected] 6 www.cellsignal.com 4 # 3 Trask Lane Danvers Massachusetts 01923 USA For Research Use Only. Not For Use In Diagnostic Procedures. Applications: Reactivity: Sensitivity: MW (kDa): Source: UniProt ID: Entrez-Gene Id: WB, IP M Endogenous 160 Rabbit Q86TI0 23216 Product Usage Information Application Dilution Western Blotting 1:1000 Immunoprecipitation 1:50 Storage Supplied in 10 mM sodium HEPES (pH 7.5), 150 mM NaCl, 100 µg/ml BSA and 50% glycerol. Store at –20°C. Do not aliquot the antibody. Specificity / Sensitivity TBC1D1 (V796) Antibody detects endogenous levels of total TBC1D1 protein. Species Reactivity: Mouse Source / Purification Polyclonal antibodies are produced by immunizing animals with a synthetic peptide corresponding to the sequence around Val796 of mouse TBC1D1. Antibodies are purified by protein A and peptide affinity chromatography. Background TBC1D1 is a paralog of AS160 (1) and both proteins share about 50% identity (2). TBC1D1 was shown to be a candidate gene for severe obesity (3). It plays a role in Glut4 translocation through its GAP activity (2,4). Studies indicate that TBC1D1 is highly expressed in skeletal muscle (1). Insulin, AICAR, and contraction directly regulate TBC1D1 phosphorylation in this tissue (1). Three AMPK phosphorylation sites (Ser231, Ser660, and Ser700) and one Akt phosphorylation site (Thr590) were identified in skeletal muscle (5). Muscle contraction or AICAR treatment increases phosphorylation on Ser231, Ser660, and Ser700 but not on Thr590; insulin increases phosphorylation on Thr590 only (5).
    [Show full text]
  • Activating Proteins TBC1D1 and TBC1D4 in Mice Eliminates Insulin- and AICAR-Stimulated Glucose Transport
    746 Diabetes Volume 64, March 2015 Alexandra Chadt,1,2 Anja Immisch,3 Christian de Wendt,1 Christian Springer,1 Zhou Zhou,1 Torben Stermann,1 Geoffrey D. Holman,4 Dominique Loffing-Cueni,5 Johannes Loffing,5 Hans-Georg Joost,2,3 and Hadi Al-Hasani1,2 Deletion of Both Rab-GTPase– Activating Proteins TBC1D1 and TBC1D4 in Mice Eliminates Insulin- and AICAR-Stimulated Glucose Transport Diabetes 2015;64:746–759 | DOI: 10.2337/db14-0368 The Rab-GTPase–activating proteins TBC1D1 and TBC1D4 from intracellular vesicles to the cell surface (1,2). The (AS160) were previously shown to regulate GLUT4 trans- two related Rab-GTPase–activating proteins TBC1D1 and location in response to activation of AKT and AMP- TBC1D4 (AS160) are phosphorylated in response to in- dependent kinase. However, knockout mice lacking sulin, AMPK, and exercise/muscle contraction and have either Tbc1d1 or Tbc1d4 displayed only partially impaired been implicated in important roles in regulating the trans- insulin-stimulated glucose uptake in fat and muscle tis- location of GLUT4 (3–9). By positional cloning, we pre- sue. The aim of this study was to determine the impact of viously identified a naturally occurring loss-of-function Tbc1d1 Tbc1d4 the combined inactivation of and on glu- mutation in Tbc1d1 as an obesity suppressor in the cose metabolism in double-deficient (D1/4KO) mice. METABOLISM lean, diabetes-resistant SJL mouse strain (10). In humans, D1/4KO mice displayed normal fasting glucose concen- mutations in TBC1D4 (R3633) and TBC1D1 (R125W) trations but had reduced tolerance to intraperitoneally have been linked to severe postprandial hyperinsulinemia administered glucose, insulin, and AICAR.
    [Show full text]