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Liu C, Zheng Y, Hu S, Liang X, Li Y, Yu Z, Liu Y, Bian Y, Man Y, Zhao S, Liu X, Liu H, Huang T, Ma J, Chen ZJ, Zhao H, Zhang Y. TOX3 deficiency mitigates hyperglycemia by suppressing hepatic gluconeogenesis through FoxO1. Metabolism 2024; 152:155766. [PMID: 38145825 DOI: 10.1016/j.metabol.2023.155766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 12/15/2023] [Accepted: 12/18/2023] [Indexed: 12/27/2023]
Abstract
BACKGROUND Excessive hepatic glucose production is a hallmark that contributes to hyperglycemia in type 2 diabetes (T2D). The regulatory network governing this process remains incompletely understood. Here, we demonstrate that TOX3, a high-mobility group family member, acts as a major transcriptional driver for hepatic glucose production. METHODS Tox3-overexpressed and knockout mice were constructed to explore its metabolic functions. Transcriptomic and chromatin-immunoprecipitation sequencing (ChIP-seq) were used to identify downstream targets of TOX3. Both FoxO1 silencing and inhibitor approaches were used to assess the contribution of FoxO1. TOX3 expression levels were examined in the livers of mice and human subjects. Finally, Tox3 was genetically manipulated in diet-induced obese mice to evaluate its therapeutic potential. RESULTS Hepatic Tox3 overexpression activates the gluconeogenic program, resulting in hyperglycemia and insulin resistance in mice. Hepatocyte-specific Tox3 knockout suppresses gluconeogenesis and improves insulin sensitivity. Mechanistically, integrated hepatic transcriptomic and ChIP-seq analyses identify FoxO1 as a direct target of TOX3. TOX3 stimulates FoxO1 transcription by directly binding to and activating its promoter, whereas FoxO1 silencing abrogates TOX3-induced dysglycemia in mice. In human subjects, hepatic TOX3 expression shows a significant positive correlation with blood glucose levels under normoglycemic conditions, yet is repressed by high glucose during T2D. Importantly, hepatic Tox3 deficiency markedly protects against and ameliorates the hyperglycemia and glucose intolerance in diet-induced diabetic mice. CONCLUSIONS Our findings establish TOX3 as a driver for excessive gluconeogenesis through activating hepatic FoxO1 transcription. TOX3 could serve as a promising target for preventing and treating hyperglycemia in T2D.
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Affiliation(s)
- Congcong Liu
- State Key Laboratory of Reproductive Medicine and Offspring Health, Shandong University, Jinan, Shandong 250012, China; Center for Reproductive Medicine, Shandong University, Jinan, Shandong 250012, China; Key Laboratory of Reproductive Endocrinology of Ministry of Education, Shandong University, Jinan, Shandong 250012, China
| | - Yuanwen Zheng
- Department of Hepatobiliary Surgery, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250021, China
| | - Shourui Hu
- State Key Laboratory of Reproductive Medicine and Offspring Health, Shandong University, Jinan, Shandong 250012, China; Center for Reproductive Medicine, Shandong University, Jinan, Shandong 250012, China; Key Laboratory of Reproductive Endocrinology of Ministry of Education, Shandong University, Jinan, Shandong 250012, China
| | - Xiaofan Liang
- State Key Laboratory of Reproductive Medicine and Offspring Health, Shandong University, Jinan, Shandong 250012, China; Center for Reproductive Medicine, Shandong University, Jinan, Shandong 250012, China; Key Laboratory of Reproductive Endocrinology of Ministry of Education, Shandong University, Jinan, Shandong 250012, China
| | - Yuxuan Li
- State Key Laboratory of Reproductive Medicine and Offspring Health, Shandong University, Jinan, Shandong 250012, China; Center for Reproductive Medicine, Shandong University, Jinan, Shandong 250012, China; Key Laboratory of Reproductive Endocrinology of Ministry of Education, Shandong University, Jinan, Shandong 250012, China
| | - Zhiheng Yu
- State Key Laboratory of Reproductive Medicine and Offspring Health, Shandong University, Jinan, Shandong 250012, China; Center for Reproductive Medicine, Shandong University, Jinan, Shandong 250012, China; Key Laboratory of Reproductive Endocrinology of Ministry of Education, Shandong University, Jinan, Shandong 250012, China
| | - Yue Liu
- State Key Laboratory of Reproductive Medicine and Offspring Health, Shandong University, Jinan, Shandong 250012, China; Center for Reproductive Medicine, Shandong University, Jinan, Shandong 250012, China; Key Laboratory of Reproductive Endocrinology of Ministry of Education, Shandong University, Jinan, Shandong 250012, China
| | - Yuehong Bian
- State Key Laboratory of Reproductive Medicine and Offspring Health, Shandong University, Jinan, Shandong 250012, China; Center for Reproductive Medicine, Shandong University, Jinan, Shandong 250012, China; Key Laboratory of Reproductive Endocrinology of Ministry of Education, Shandong University, Jinan, Shandong 250012, China; Shandong Key Laboratory of Reproductive Medicine, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250012, China; Shandong Provincial Clinical Research Center for Reproductive Health, Jinan, Shandong 250012, China
| | - Yuanyuan Man
- State Key Laboratory of Reproductive Medicine and Offspring Health, Shandong University, Jinan, Shandong 250012, China; Center for Reproductive Medicine, Shandong University, Jinan, Shandong 250012, China; Key Laboratory of Reproductive Endocrinology of Ministry of Education, Shandong University, Jinan, Shandong 250012, China
| | - Shigang Zhao
- State Key Laboratory of Reproductive Medicine and Offspring Health, Shandong University, Jinan, Shandong 250012, China; Center for Reproductive Medicine, Shandong University, Jinan, Shandong 250012, China; Key Laboratory of Reproductive Endocrinology of Ministry of Education, Shandong University, Jinan, Shandong 250012, China; Shandong Key Laboratory of Reproductive Medicine, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250012, China; Shandong Provincial Clinical Research Center for Reproductive Health, Jinan, Shandong 250012, China
| | - Xin Liu
- State Key Laboratory of Reproductive Medicine and Offspring Health, Shandong University, Jinan, Shandong 250012, China; Center for Reproductive Medicine, Shandong University, Jinan, Shandong 250012, China; Key Laboratory of Reproductive Endocrinology of Ministry of Education, Shandong University, Jinan, Shandong 250012, China; Shandong Key Laboratory of Reproductive Medicine, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250012, China; Shandong Provincial Clinical Research Center for Reproductive Health, Jinan, Shandong 250012, China
| | - Hongbin Liu
- State Key Laboratory of Reproductive Medicine and Offspring Health, Shandong University, Jinan, Shandong 250012, China; Center for Reproductive Medicine, Shandong University, Jinan, Shandong 250012, China; Key Laboratory of Reproductive Endocrinology of Ministry of Education, Shandong University, Jinan, Shandong 250012, China; Shandong Key Laboratory of Reproductive Medicine, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250012, China; Shandong Provincial Clinical Research Center for Reproductive Health, Jinan, Shandong 250012, China
| | - Tao Huang
- State Key Laboratory of Reproductive Medicine and Offspring Health, Shandong University, Jinan, Shandong 250012, China; Center for Reproductive Medicine, Shandong University, Jinan, Shandong 250012, China; Key Laboratory of Reproductive Endocrinology of Ministry of Education, Shandong University, Jinan, Shandong 250012, China; Shandong Key Laboratory of Reproductive Medicine, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250012, China; Shandong Provincial Clinical Research Center for Reproductive Health, Jinan, Shandong 250012, China
| | - Jinlong Ma
- State Key Laboratory of Reproductive Medicine and Offspring Health, Shandong University, Jinan, Shandong 250012, China; Center for Reproductive Medicine, Shandong University, Jinan, Shandong 250012, China; Key Laboratory of Reproductive Endocrinology of Ministry of Education, Shandong University, Jinan, Shandong 250012, China; Shandong Key Laboratory of Reproductive Medicine, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250012, China; Shandong Provincial Clinical Research Center for Reproductive Health, Jinan, Shandong 250012, China
| | - Zi-Jiang Chen
- State Key Laboratory of Reproductive Medicine and Offspring Health, Shandong University, Jinan, Shandong 250012, China; Center for Reproductive Medicine, Shandong University, Jinan, Shandong 250012, China; Key Laboratory of Reproductive Endocrinology of Ministry of Education, Shandong University, Jinan, Shandong 250012, China; Shandong Key Laboratory of Reproductive Medicine, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250012, China; Shandong Provincial Clinical Research Center for Reproductive Health, Jinan, Shandong 250012, China; Research Unit of Gametogenesis and Health of ART-Offspring, Chinese Academy of Medical Sciences (No.2021RU001), Jinan, Shandong 250012, China; Shanghai Key Laboratory for Assisted Reproduction and Reproductive Genetics, Shanghai 200135, China; Department of Reproductive Medicine, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200135, China.
| | - Han Zhao
- State Key Laboratory of Reproductive Medicine and Offspring Health, Shandong University, Jinan, Shandong 250012, China; Center for Reproductive Medicine, Shandong University, Jinan, Shandong 250012, China; Key Laboratory of Reproductive Endocrinology of Ministry of Education, Shandong University, Jinan, Shandong 250012, China; Shandong Key Laboratory of Reproductive Medicine, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250012, China; Shandong Provincial Clinical Research Center for Reproductive Health, Jinan, Shandong 250012, China.
| | - Yuqing Zhang
- State Key Laboratory of Reproductive Medicine and Offspring Health, Shandong University, Jinan, Shandong 250012, China; Center for Reproductive Medicine, Shandong University, Jinan, Shandong 250012, China; Key Laboratory of Reproductive Endocrinology of Ministry of Education, Shandong University, Jinan, Shandong 250012, China; Shandong Key Laboratory of Reproductive Medicine, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250012, China; Shandong Provincial Clinical Research Center for Reproductive Health, Jinan, Shandong 250012, China.
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2
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Shah A, Wondisford FE. Gluconeogenesis Flux in Metabolic Disease. Annu Rev Nutr 2023; 43:153-177. [PMID: 37603427 DOI: 10.1146/annurev-nutr-061121-091507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/23/2023]
Abstract
Gluconeogenesis is a critical biosynthetic process that helps maintain whole-body glucose homeostasis and becomes altered in certain medical diseases. We review gluconeogenic flux in various medical diseases, including common metabolic disorders, hormonal imbalances, specific inborn genetic errors, and cancer. We discuss how the altered gluconeogenic activity contributes to disease pathogenesis using data from experiments using isotopic tracer and spectroscopy methodologies. These in vitro, animal, and human studies provide insights into the changes in circulating levels of available gluconeogenesis substrates and the efficiency of converting those substrates to glucose by gluconeogenic organs. We highlight ongoing knowledge gaps, discuss emerging research areas, and suggest future investigations. A better understanding of altered gluconeogenesis flux may ultimately identify novel and targeted treatment strategies for such diseases.
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Affiliation(s)
- Ankit Shah
- Department of Medicine, Robert Wood Johnson Medical School, Rutgers University, New Brunswick, New Jersey, USA; ,
| | - Fredric E Wondisford
- Department of Medicine, Robert Wood Johnson Medical School, Rutgers University, New Brunswick, New Jersey, USA; ,
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3
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Ramatchandirin B, Pearah A, He L. Regulation of Liver Glucose and Lipid Metabolism by Transcriptional Factors and Coactivators. Life (Basel) 2023; 13:life13020515. [PMID: 36836874 PMCID: PMC9962321 DOI: 10.3390/life13020515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 02/08/2023] [Accepted: 02/10/2023] [Indexed: 02/16/2023] Open
Abstract
The prevalence of nonalcoholic fatty liver disease (NAFLD) worldwide is on the rise and NAFLD is becoming the most common cause of chronic liver disease. In the USA, NAFLD affects over 30% of the population, with similar occurrence rates reported from Europe and Asia. This is due to the global increase in obesity and type 2 diabetes mellitus (T2DM) because patients with obesity and T2DM commonly have NAFLD, and patients with NAFLD are often obese and have T2DM with insulin resistance and dyslipidemia as well as hypertriglyceridemia. Excessive accumulation of triglycerides is a hallmark of NAFLD and NAFLD is now recognized as the liver disease component of metabolic syndrome. Liver glucose and lipid metabolisms are intertwined and carbon flux can be used to generate glucose or lipids; therefore, in this review we discuss the important transcription factors and coactivators that regulate glucose and lipid metabolism.
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Affiliation(s)
| | - Alexia Pearah
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Ling He
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, 600 N. Wolfe St, Baltimore, MD 21287, USA
- Correspondence: ; Tel.: +1-410-502-5765; Fax: +1-410-502-5779
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4
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Kapadia B, Behera S, Kumar ST, Shah T, Edwin RK, Babu PP, Chakrabarti P, Parsa KV, Misra P. PIMT regulates hepatic gluconeogenesis in mice. iScience 2023; 26:106120. [PMID: 36866247 PMCID: PMC9972567 DOI: 10.1016/j.isci.2023.106120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 11/29/2022] [Accepted: 01/30/2023] [Indexed: 02/05/2023] Open
Abstract
The physiological and metabolic functions of PIMT/TGS1, a third-generation transcriptional apparatus protein, in glucose homeostasis sustenance are unclear. Here, we observed that the expression of PIMT was upregulated in the livers of short-term fasted and obese mice. Lentiviruses expressing Tgs1-specific shRNA or cDNA were injected into wild-type mice. Gene expression, hepatic glucose output, glucose tolerance, and insulin sensitivity were evaluated in mice and primary hepatocytes. Genetic modulation of PIMT exerted a direct positive impact on the gluconeogenic gene expression program and hepatic glucose output. Molecular studies utilizing cultured cells, in vivo models, genetic manipulation, and PKA pharmacological inhibition establish that PKA regulates PIMT at post-transcriptional/translational and post-translational levels. PKA enhanced 3'UTR-mediated translation of TGS1 mRNA and phosphorylated PIMT at Ser656, increasing Ep300-mediated gluconeogenic transcriptional activity. The PKA-PIMT-Ep300 signaling module and associated PIMT regulation may serve as a key driver of gluconeogenesis, positioning PIMT as a critical hepatic glucose sensor.
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Affiliation(s)
- Bandish Kapadia
- Center for Innovation in Molecular and Pharmaceutical Sciences, Dr. Reddy’s Institute of Life Sciences (DRILS), University of Hyderabad Campus, Hyderabad, TG 500046, India
| | - Soma Behera
- Center for Innovation in Molecular and Pharmaceutical Sciences, Dr. Reddy’s Institute of Life Sciences (DRILS), University of Hyderabad Campus, Hyderabad, TG 500046, India
| | - Sireesh T. Kumar
- Department of Biotechnology, University of Hyderabad, Hyderabad 500046, India
| | - Tapan Shah
- Department of Biochemistry, Saurashtra University, Rajkot 360005, India
| | - Rebecca Kristina Edwin
- Center for Innovation in Molecular and Pharmaceutical Sciences, Dr. Reddy’s Institute of Life Sciences (DRILS), University of Hyderabad Campus, Hyderabad, TG 500046, India
| | | | | | - Kishore V.L. Parsa
- Center for Innovation in Molecular and Pharmaceutical Sciences, Dr. Reddy’s Institute of Life Sciences (DRILS), University of Hyderabad Campus, Hyderabad, TG 500046, India,Corresponding author
| | - Parimal Misra
- Center for Innovation in Molecular and Pharmaceutical Sciences, Dr. Reddy’s Institute of Life Sciences (DRILS), University of Hyderabad Campus, Hyderabad, TG 500046, India,Corresponding author
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5
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Martins VF, LaBarge SA, Stanley A, Svensson K, Hung CW, Keinan O, Ciaraldi TP, Banoian D, Park JE, Ha C, Hetrick B, Meyer GA, Philp A, David LL, Henry RR, Aslan JE, Saltiel AR, McCurdy CE, Schenk S. p300 or CBP is required for insulin-stimulated glucose uptake in skeletal muscle and adipocytes. JCI Insight 2021; 7:141344. [PMID: 34813504 PMCID: PMC8765050 DOI: 10.1172/jci.insight.141344] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 11/19/2021] [Indexed: 11/17/2022] Open
Abstract
While current thinking posits that insulin signaling to GLUT4 exocytic translocation and glucose uptake in skeletal muscle and adipocytes is controlled by phosphorylation-based signaling, many proteins in this pathway are acetylated on lysine residues. However, the importance of acetylation and lysine acetyltransferases to insulin-stimulated glucose uptake is incompletely defined. Here, we demonstrate that combined loss of the acetyltransferases E1A binding protein p300 (p300) and cAMP response element binding protein binding protein (CBP) in mouse skeletal muscle causes a complete loss of insulin-stimulated glucose uptake. Similarly, brief (i.e. 1 h) pharmacological inhibition of p300/CBP acetyltransferase activity recapitulates this phenotype in human and rodent myotubes, 3T3-L1 adipocytes, and mouse muscle. Mechanistically, these effects are due to p300/CBP-mediated regulation of GLUT4 exocytic translocation and occurs downstream of Akt signaling. Taken together, we highlight a fundamental role for acetylation and p300/CBP in the direct regulation of insulin-stimulated glucose transport in skeletal muscle and adipocytes.
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Affiliation(s)
- Vitor F Martins
- Department of Orthopedic Surgery, University of California, San Diego, La Jolla, United States of America
| | - Samuel A LaBarge
- Department of Orthopedic Surgery, University of California, San Diego, La Jolla, United States of America
| | - Alexandra Stanley
- Department of Orthopedic Surgery, University of California, San Diego, La Jolla, United States of America
| | - Kristoffer Svensson
- Department of Orthopedic Surgery, University of California, San Diego, La Jolla, United States of America
| | - Chao-Wei Hung
- Department of Medicine, University of California, San Diego, La Jolla, United States of America
| | - Omer Keinan
- Department of Medicine, University of California, San Diego, La Jolla, United States of America
| | - Theodore P Ciaraldi
- Department of Medicine, University of California, San Diego, La Jolla, United States of America
| | - Dion Banoian
- Department of Orthopedic Surgery, University of California, San Diego, La Jolla, United States of America
| | - Ji E Park
- Department of Orthopedic Surgery, University of California, San Diego, La Jolla, United States of America
| | - Christina Ha
- Department of Orthopedic Surgery, University of California, San Diego, La Jolla, United States of America
| | - Byron Hetrick
- Department of Human Physiology, University of Oregon, Eugene, United States of America
| | - Gretchen A Meyer
- Program in Physical Therapy, Washington University in St. Louis, St. Louis, United States of America
| | - Andrew Philp
- Mitochondrial Metabolism and Ageing, Garvan Institute of Medical Research, Darlinghurst, Australia
| | - Larry L David
- Department of Biochemistry and Molecular Biology, Oregon Health & Science University, Portland, United States of America
| | - Robert R Henry
- Division of Endocrinology & Metabolism, VA San Diego Healthcare System, San Diego, United States of America
| | - Joseph E Aslan
- Knight Cardiovascular Institute, Oregon Health & Science University, Portland, United States of America
| | - Alan R Saltiel
- University of California, San Diego, La Jolla, United States of America
| | - Carrie E McCurdy
- Department of Human Physiology, University of Oregon, Eugene, United States of America
| | - Simon Schenk
- Department of Orthopedic Surgery, University of California, San Diego, La Jolla, United States of America
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6
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Ramms DJ, Raimondi F, Arang N, Herberg FW, Taylor SS, Gutkind JS. G αs-Protein Kinase A (PKA) Pathway Signalopathies: The Emerging Genetic Landscape and Therapeutic Potential of Human Diseases Driven by Aberrant G αs-PKA Signaling. Pharmacol Rev 2021; 73:155-197. [PMID: 34663687 PMCID: PMC11060502 DOI: 10.1124/pharmrev.120.000269] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Many of the fundamental concepts of signal transduction and kinase activity are attributed to the discovery and crystallization of cAMP-dependent protein kinase, or protein kinase A. PKA is one of the best-studied kinases in human biology, with emphasis in biochemistry and biophysics, all the way to metabolism, hormone action, and gene expression regulation. It is surprising, however, that our understanding of PKA's role in disease is largely underappreciated. Although genetic mutations in the PKA holoenzyme are known to cause diseases such as Carney complex, Cushing syndrome, and acrodysostosis, the story largely stops there. With the recent explosion of genomic medicine, we can finally appreciate the broader role of the Gαs-PKA pathway in disease, with contributions from aberrant functioning G proteins and G protein-coupled receptors, as well as multiple alterations in other pathway components and negative regulators. Together, these represent a broad family of diseases we term the Gαs-PKA pathway signalopathies. The Gαs-PKA pathway signalopathies encompass diseases caused by germline, postzygotic, and somatic mutations in the Gαs-PKA pathway, with largely endocrine and neoplastic phenotypes. Here, we present a signaling-centric review of Gαs-PKA-driven pathophysiology and integrate computational and structural analysis to identify mutational themes commonly exploited by the Gαs-PKA pathway signalopathies. Major mutational themes include hotspot activating mutations in Gαs, encoded by GNAS, and mutations that destabilize the PKA holoenzyme. With this review, we hope to incite further study and ultimately the development of new therapeutic strategies in the treatment of a wide range of human diseases. SIGNIFICANCE STATEMENT: Little recognition is given to the causative role of Gαs-PKA pathway dysregulation in disease, with effects ranging from infectious disease, endocrine syndromes, and many cancers, yet these disparate diseases can all be understood by common genetic themes and biochemical signaling connections. By highlighting these common pathogenic mechanisms and bridging multiple disciplines, important progress can be made toward therapeutic advances in treating Gαs-PKA pathway-driven disease.
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Affiliation(s)
- Dana J Ramms
- Department of Pharmacology (D.J.R., N.A., J.S.G.), Department of Chemistry and Biochemistry (S.S.T.), and Moores Cancer Center (D.J.R., N.A., J.S.G.), University of California, San Diego, La Jolla, California; Laboratorio di Biologia Bio@SNS, Scuola Normale Superiore, Pisa, Italy (F.R.); and Department of Biochemistry, University of Kassel, Kassel, Germany (F.W.H.)
| | - Francesco Raimondi
- Department of Pharmacology (D.J.R., N.A., J.S.G.), Department of Chemistry and Biochemistry (S.S.T.), and Moores Cancer Center (D.J.R., N.A., J.S.G.), University of California, San Diego, La Jolla, California; Laboratorio di Biologia Bio@SNS, Scuola Normale Superiore, Pisa, Italy (F.R.); and Department of Biochemistry, University of Kassel, Kassel, Germany (F.W.H.)
| | - Nadia Arang
- Department of Pharmacology (D.J.R., N.A., J.S.G.), Department of Chemistry and Biochemistry (S.S.T.), and Moores Cancer Center (D.J.R., N.A., J.S.G.), University of California, San Diego, La Jolla, California; Laboratorio di Biologia Bio@SNS, Scuola Normale Superiore, Pisa, Italy (F.R.); and Department of Biochemistry, University of Kassel, Kassel, Germany (F.W.H.)
| | - Friedrich W Herberg
- Department of Pharmacology (D.J.R., N.A., J.S.G.), Department of Chemistry and Biochemistry (S.S.T.), and Moores Cancer Center (D.J.R., N.A., J.S.G.), University of California, San Diego, La Jolla, California; Laboratorio di Biologia Bio@SNS, Scuola Normale Superiore, Pisa, Italy (F.R.); and Department of Biochemistry, University of Kassel, Kassel, Germany (F.W.H.)
| | - Susan S Taylor
- Department of Pharmacology (D.J.R., N.A., J.S.G.), Department of Chemistry and Biochemistry (S.S.T.), and Moores Cancer Center (D.J.R., N.A., J.S.G.), University of California, San Diego, La Jolla, California; Laboratorio di Biologia Bio@SNS, Scuola Normale Superiore, Pisa, Italy (F.R.); and Department of Biochemistry, University of Kassel, Kassel, Germany (F.W.H.)
| | - J Silvio Gutkind
- Department of Pharmacology (D.J.R., N.A., J.S.G.), Department of Chemistry and Biochemistry (S.S.T.), and Moores Cancer Center (D.J.R., N.A., J.S.G.), University of California, San Diego, La Jolla, California; Laboratorio di Biologia Bio@SNS, Scuola Normale Superiore, Pisa, Italy (F.R.); and Department of Biochemistry, University of Kassel, Kassel, Germany (F.W.H.)
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7
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Zhu YX, Hu HQ, Zuo ML, Mao L, Song GL, Li TM, Dong LC, Yang ZB, Ali Sheikh MS. Effect of oxymatrine on liver gluconeogenesis is associated with the regulation of PEPCK and G6Pase expression and AKT phosphorylation. Biomed Rep 2021; 15:56. [PMID: 34007449 PMCID: PMC8120346 DOI: 10.3892/br.2021.1432] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 03/05/2021] [Indexed: 12/21/2022] Open
Abstract
An increase in liver gluconeogenesis is an important pathological phenomenon in type 2 diabetes mellitus (T2DM) and oxymatrine is an effective natural drug used for T2DM treatment. The present study aimed to explore the effect of oxymatrine on gluconeogenesis and elucidate the underlying mechanism. Male Sprague-Dawley rats were treated with a high-fat diet and streptozotocin for 4 weeks to induce T2DM, and HepG2 cells were treated with 55 mM glucose to simulate T2DM in vitro. T2DM rats were treated with oxymatrine (10 or 20 mg/kg weight) or metformin for 4 weeks, and HepG2 cells were treated with oxymatrine (0.1 or 1 µM), metformin (0.1 µM), or oxymatrine combined with MK-2206 (AKT inhibitor) for 24 h. Fasting blood glucose and insulin sensitivity of rats were measured to evaluate insulin resistance. Glucose production and uptake ability were measured to evaluate gluconeogenesis in HepG2 cells, and the expression of related genes was detected to explore the molecular mechanism. Additionally, the body weight, liver weight and liver index were measured and hematoxylin and eosin staining was performed to evaluate the effects of the disease. The fasting glucose levels of T2DM rats was 16.5 mmol/l, whereas in the control rats, it was 6.1 mmol/l. Decreased insulin sensitivity (K-value, 0.2), body weight loss (weight, 300 g), liver weight gain, liver index increase (value, 48) and morphological changes were observed in T2DM rats, accompanied by reduced AKT phosphorylation, and upregulated expression of phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase). High-glucose treatment significantly increased glucose production and decreased glucose uptake in HepG2 cells, concomitant with a decrease in AKT phosphorylation and increase of PEPCK and G6Pase expression. In vivo, oxymatrine dose-dependently increased the sensitivity of T2DM rats to insulin, increased AKT phosphorylation and decreased PEPCK and G6Pase expression in the liver, and reversed the liver morphological changes. In vitro, oxymatrine dose-dependently increased AKT phosphorylation and glucose uptake of HepG2 cells subjected to high-glucose treatment, which was accompanied by inhibition of the expression of the gluconeogenesis-related genes, PEPCK and G6Pase. MK-2206 significantly inhibited the protective effects of oxymatrine in high-glucose-treated cells. These data indicated that oxymatrine can effectively prevent insulin resistance and gluconeogenesis, and its mechanism may be at least partly associated with the regulation of PEPCK and G6Pase expression and AKT phosphorylation in the liver.
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Affiliation(s)
- Yu-Xian Zhu
- The Affiliated Changsha Hospital of Hunan Normal University, Changsha, Hunan 410006, P.R. China.,College of Medicine, Hunan Normal University Changsha, Hunan 410000, P.R. China
| | - Hai-Qing Hu
- The Affiliated Changsha Hospital of Hunan Normal University, Changsha, Hunan 410006, P.R. China
| | - Mei-Ling Zuo
- The Affiliated Changsha Hospital of Hunan Normal University, Changsha, Hunan 410006, P.R. China
| | - Li Mao
- Department of Basic Medicine, Changsha Health Vocational College, Changsha, Hunan 410600, P.R. China
| | - Gui-Lin Song
- The Affiliated Changsha Hospital of Hunan Normal University, Changsha, Hunan 410006, P.R. China.,Institute of Emergency and Critical Care Medicine of Changsha, Changsha, Hunan 410006, P.R. China
| | - Tao-Ming Li
- The Affiliated Changsha Hospital of Hunan Normal University, Changsha, Hunan 410006, P.R. China
| | - Li-Chen Dong
- The Affiliated Changsha Hospital of Hunan Normal University, Changsha, Hunan 410006, P.R. China
| | - Zhong-Bao Yang
- The Affiliated Changsha Hospital of Hunan Normal University, Changsha, Hunan 410006, P.R. China.,Institute of Emergency and Critical Care Medicine of Changsha, Changsha, Hunan 410006, P.R. China
| | - Md Sayed Ali Sheikh
- Internal Medicine Department, Cardiology, College of Medicine, Al Jouf University, Sakaka, Al Jouf 72388, Saudi Arabia
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8
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Alterations of Gut Microbiota by Overnutrition Impact Gluconeogenic Gene Expression and Insulin Signaling. Int J Mol Sci 2021; 22:ijms22042121. [PMID: 33672754 PMCID: PMC7924631 DOI: 10.3390/ijms22042121] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 02/10/2021] [Accepted: 02/17/2021] [Indexed: 02/04/2023] Open
Abstract
A high-fat, Western-style diet is an important predisposing factor for the onset of type 2 diabetes and obesity. It causes changes in gut microbial profile, reduction of microbial diversity, and the impairment of the intestinal barrier, leading to increased serum lipopolysaccharide (endotoxin) levels. Elevated lipopolysaccharide (LPS) induces acetyltransferase P300 both in the nucleus and cytoplasm of liver hepatocytes through the activation of the IRE1-XBP1 pathway in the endoplasmic reticulum stress. In the nucleus, induced P300 acetylates CRTC2 to increase CRTC2 abundance and drives Foxo1 gene expression, resulting in increased expression of the rate-limiting gluconeogenic gene G6pc and Pck1 and abnormal liver glucose production. Furthermore, abnormal cytoplasm-appearing P300 acetylates IRS1 and IRS2 to disrupt insulin signaling, leading to the prevention of nuclear exclusion and degradation of FOXO1 proteins to further exacerbate the expression of G6pc and Pck1 genes and liver glucose production. Inhibition of P300 acetyltransferase activity by chemical inhibitors improved insulin signaling and alleviated hyperglycemia in obese mice. Thus, P300 acetyltransferase activity appears to be a therapeutic target for the treatment of type 2 diabetes and obesity.
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9
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Kosaraju J, Seegobin M, Gouveia A, Syal C, Sarma SN, Lu KJ, Ilin J, He L, Wondisford FE, Lagace D, De Repentigny Y, Kothary R, Wang J. Metformin promotes CNS remyelination and improves social interaction following focal demyelination through CBP Ser436 phosphorylation. Exp Neurol 2020; 334:113454. [PMID: 32877653 DOI: 10.1016/j.expneurol.2020.113454] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Revised: 08/15/2020] [Accepted: 08/26/2020] [Indexed: 02/04/2023]
Abstract
Individuals with demyelinating diseases often experience difficulties during social interactions that are not well studied in preclinical models. Here, we describe a novel juvenile focal corpus callosum demyelination murine model exhibiting a social interaction deficit. Using this preclinical murine demyelination model, we discover that application of metformin, an FDA-approved drug, in this model promotes oligodendrocyte regeneration and remyelination and improves the social interaction. This beneficial effect of metformin acts through stimulating Ser436 phosphorylation in CBP, a histone acetyltransferase. In addition, we found that metformin acts through two distinct molecular pathways to enhance oligodendrocyte precursor (OPC) proliferation and differentiation, respectively. Metformin enhances OPC proliferation through early-stage autophagy inhibition, while metformin promotes OPC differentiation into mature oligodendrocytes through activating CBP Ser436 phosphorylation. In summary, we identify that metformin is a promising remyelinating agent to improve juvenile demyelination-associated social interaction deficits by promoting oligodendrocyte regeneration and remyelination.
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Affiliation(s)
- Jayasankar Kosaraju
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
| | - Matthew Seegobin
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
| | - Ayden Gouveia
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
| | - Charvi Syal
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada; Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Sailendra Nath Sarma
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
| | - Kevin Jiaqi Lu
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
| | - Julius Ilin
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
| | - Ling He
- Department of Pediatrics and Medicine, Johns Hopkins Medical School, Baltimore, MD 21287, USA
| | - Fredric E Wondisford
- Department of Medicine, Rutgers-Robert Wood Johnson Medical School, New Brunswick, NJ 08901, USA
| | - Diane Lagace
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada; University of Ottawa Brain and Mind Research Institute, Ottawa, ON K1H 8M5, Canada; Canadian Partnership for Stroke Recovery, Ottawa, ON K1G 5Z3, Canada
| | - Yves De Repentigny
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
| | - Rashmi Kothary
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada; Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada; University of Ottawa Brain and Mind Research Institute, Ottawa, ON K1H 8M5, Canada; Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Jing Wang
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada; Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada; University of Ottawa Brain and Mind Research Institute, Ottawa, ON K1H 8M5, Canada; Canadian Partnership for Stroke Recovery, Ottawa, ON K1G 5Z3, Canada.
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10
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Seenappa V, Joshi MB, Satyamoorthy K. Intricate Regulation of Phosphoenolpyruvate Carboxykinase (PEPCK) Isoforms in Normal Physiology and Disease. Curr Mol Med 2020; 19:247-272. [PMID: 30947672 DOI: 10.2174/1566524019666190404155801] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 03/25/2019] [Accepted: 03/27/2019] [Indexed: 02/06/2023]
Abstract
BACKGROUND The phosphoenolpyruvate carboxykinase (PEPCK) isoforms are considered as rate-limiting enzymes for gluconeogenesis and glyceroneogenesis pathways. PEPCK exhibits several interesting features such as a) organelle-specific isoforms (cytosolic and a mitochondrial) in vertebrate clade, b) tissue-specific expression of isoforms and c) organism-specific requirement of ATP or GTP as a cofactor. In higher organisms, PEPCK isoforms are intricately regulated and activated through several physiological and pathological stimuli such as corticoids, hormones, nutrient starvation and hypoxia. Isoform-specific transcriptional/translational regulation and their interplay in maintaining glucose homeostasis remain to be fully understood. Mounting evidence indicates the significant involvement of PEPCK isoforms in physiological processes (development and longevity) and in the progression of a variety of diseases (metabolic disorders, cancer, Smith-Magenis syndrome). OBJECTIVE The present systematic review aimed to assimilate existing knowledge of transcriptional and translational regulation of PEPCK isoforms derived from cell, animal and clinical models. CONCLUSION Based on current knowledge and extensive bioinformatics analysis, in this review we have provided a comparative (epi)genetic understanding of PCK1 and PCK2 genes encompassing regulatory elements, disease-associated polymorphisms, copy number variations, regulatory miRNAs and CpG densities. We have also discussed various exogenous and endogenous modulators of PEPCK isoforms and their signaling mechanisms. A comprehensive review of existing knowledge of PEPCK regulation and function may enable identification of the underlying gaps to design new pharmacological strategies and interventions for the diseases associated with gluconeogenesis.
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Affiliation(s)
- Venu Seenappa
- School of Life Sciences, Manipal Academy of Higher Education, Manipal - 576104, India
| | - Manjunath B Joshi
- School of Life Sciences, Manipal Academy of Higher Education, Manipal - 576104, India
| | - Kapaettu Satyamoorthy
- School of Life Sciences, Manipal Academy of Higher Education, Manipal - 576104, India
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11
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Zhao H, Zhang F, Sun D, Wang X, Zhang X, Zhang J, Yan F, Huang C, Xie H, Lin C, Liu Y, Fan M, Yan W, Chen Y, Lian K, Li Y, Zhang L, Wang S, Tao L. Branched-Chain Amino Acids Exacerbate Obesity-Related Hepatic Glucose and Lipid Metabolic Disorders via Attenuating Akt2 Signaling. Diabetes 2020; 69:1164-1177. [PMID: 32184272 DOI: 10.2337/db19-0920] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 03/09/2020] [Indexed: 01/08/2023]
Abstract
Branched chain amino acids (BCAAs) are associated with the progression of obesity-related metabolic disorders, including type 2 diabetes and nonalcoholic fatty liver disease. However, whether BCAAs disrupt the homeostasis of hepatic glucose and lipid metabolism remains unknown. In this study, we observed that BCAAs supplementation significantly reduced high-fat (HF) diet-induced hepatic lipid accumulation while increasing the plasma lipid levels and promoting muscular and renal lipid accumulation. Further studies demonstrated that BCAAs supplementation significantly increased hepatic gluconeogenesis and suppressed hepatic lipogenesis in HF diet-induced obese (DIO) mice. These phenotypes resulted from severe attenuation of Akt2 signaling via mTORC1- and mTORC2-dependent pathways. BCAAs/branched-chain α-keto acids (BCKAs) chronically suppressed Akt2 activation through mTORC1 and mTORC2 signaling and promoted Akt2 ubiquitin-proteasome-dependent degradation through the mTORC2 pathway. Moreover, the E3 ligase Mul1 played an essential role in BCAAs/BCKAs-mTORC2-induced Akt2 ubiquitin-dependent degradation. We also demonstrated that BCAAs inhibited hepatic lipogenesis by blocking Akt2/SREBP1/INSIG2a signaling and increased hepatic glycogenesis by regulating Akt2/Foxo1 signaling. Collectively, these data demonstrate that in DIO mice, BCAAs supplementation resulted in serious hepatic metabolic disorder and severe liver insulin resistance: insulin failed to not only suppress gluconeogenesis but also activate lipogenesis. Intervening BCAA metabolism is a potential therapeutic target for severe insulin-resistant disease.
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Affiliation(s)
- Huishou Zhao
- Department of Cardiology, Xijing Hospital, Air Force Military Medical University, Xi'an, Shaanxi, China
| | - Fuyang Zhang
- Department of Cardiology, Xijing Hospital, Air Force Military Medical University, Xi'an, Shaanxi, China
| | - Dan Sun
- Department of Assisted Reproduction Center, Tangdu Hospital, Air Force Military Medical University, Xi'an, Shaanxi, China
| | - Xiong Wang
- Department of Cardiology, Xijing Hospital, Air Force Military Medical University, Xi'an, Shaanxi, China
| | - Xiaomeng Zhang
- Department of Cardiology, Xijing Hospital, Air Force Military Medical University, Xi'an, Shaanxi, China
| | - Jinglong Zhang
- Department of Cardiology, Xijing Hospital, Air Force Military Medical University, Xi'an, Shaanxi, China
| | - Feng Yan
- Department of Cardiology, Xijing Hospital, Air Force Military Medical University, Xi'an, Shaanxi, China
| | - Chong Huang
- Department of Cardiology, Xijing Hospital, Air Force Military Medical University, Xi'an, Shaanxi, China
| | - Huaning Xie
- Department of Cardiology, Xijing Hospital, Air Force Military Medical University, Xi'an, Shaanxi, China
| | - Chen Lin
- Department of Cardiology, Xijing Hospital, Air Force Military Medical University, Xi'an, Shaanxi, China
| | - Yi Liu
- Department of Cardiology, Xijing Hospital, Air Force Military Medical University, Xi'an, Shaanxi, China
| | - Miaomiao Fan
- Department of Cardiology, Xijing Hospital, Air Force Military Medical University, Xi'an, Shaanxi, China
| | - Wenjun Yan
- Department of Cardiology, Xijing Hospital, Air Force Military Medical University, Xi'an, Shaanxi, China
| | - Youhu Chen
- Department of Cardiology, Xijing Hospital, Air Force Military Medical University, Xi'an, Shaanxi, China
| | - Kun Lian
- Department of Cardiology, Xijing Hospital, Air Force Military Medical University, Xi'an, Shaanxi, China
| | - Yueyang Li
- Department of Cardiology, Xijing Hospital, Air Force Military Medical University, Xi'an, Shaanxi, China
| | - Ling Zhang
- Department of Cardiology, Xijing Hospital, Air Force Military Medical University, Xi'an, Shaanxi, China
| | - Shan Wang
- Department of Cardiology, Xijing Hospital, Air Force Military Medical University, Xi'an, Shaanxi, China
| | - Ling Tao
- Department of Cardiology, Xijing Hospital, Air Force Military Medical University, Xi'an, Shaanxi, China
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12
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Syal C, Kosaraju J, Hamilton L, Aumont A, Chu A, Sarma SN, Thomas J, Seegobin M, Dilworth FJ, He L, Wondisford FE, Zimmermann R, Parent M, Fernandes K, Wang J. Dysregulated expression of monoacylglycerol lipase is a marker for anti-diabetic drug metformin-targeted therapy to correct impaired neurogenesis and spatial memory in Alzheimer's disease. Am J Cancer Res 2020; 10:6337-6360. [PMID: 32483456 PMCID: PMC7255032 DOI: 10.7150/thno.44962] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2020] [Accepted: 04/28/2020] [Indexed: 12/17/2022] Open
Abstract
Rationale: Monoacylglycerol lipase (Mgll), a hydrolase that breaks down the endocannabinoid 2-arachidonoyl glycerol (2-AG) to produce arachidonic acid (ARA), is a potential target for neurodegenerative diseases, such as Alzheimer's disease (AD). Increasing evidence shows that impairment of adult neurogenesis by perturbed lipid metabolism predisposes patients to AD. However, it remains unknown what causes aberrant expression of Mgll in AD and how Mgll-regulated lipid metabolism impacts adult neurogenesis, thus predisposing to AD during aging. Here, we identify Mgll as an aging-induced factor that impairs adult neurogenesis and spatial memory in AD, and show that metformin, an FDA-approved anti-diabetic drug, can reduce the expression of Mgll to reverse impaired adult neurogenesis, prevent spatial memory decline and reduce β-amyloid accumulation. Methods: Mgll expression was assessed in both human AD patient post-mortem hippocampal tissues and 3xTg-AD mouse model. In addition, we used both the 3xTg-AD animal model and the CbpS436A genetic knock-in mouse model to identify that elevated Mgll expression is caused by the attenuation of the aPKC-CBP pathway, involving atypical protein kinase C (aPKC)-stimulated Ser436 phosphorylation of histone acetyltransferase CBP through biochemical methods. Furthermore, we performed in vivo adult neurogenesis assay with BrdU/EdU labelling and Morris water maze task in both animal models following pharmacological treatments to show the key role of Mgll in metformin-corrected neurogenesis and spatial memory deficits of AD through reactivating the aPKC-CBP pathway. Finally, we performed in vitro adult neurosphere assays using both animal models to study the role of the aPKC-CBP mediated Mgll repression in determining adult neural stem/progenitor cell (NPC) fate. Results: Here, we demonstrate that aging-dependent induction of Mgll is observed in the 3xTg-AD model and human AD patient post-mortem hippocampal tissues. Importantly, we discover that elevated Mgll expression is caused by the attenuation of the aPKC-CBP pathway. The accumulation of Mgll in the 3xTg-AD mice reduces the genesis of newborn neurons and perturbs spatial memory. However, we find that metformin-stimulated aPKC-CBP pathway decreases Mgll expression to recover these deficits in 3xTg-AD. In addition, we reveal that elevated Mgll levels in cultured adult NPCs from both 3xTg-AD and CbpS436A animal models are responsible for their NPC neuronal differentiation deficits. Conclusion: Our findings set the stage for development of a clinical protocol where Mgll would serve as a biomarker in early stages of AD to identify potential metformin-responsive AD patients to restore their neurogenesis and spatial memory.
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13
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Histone demethylase JMJD1C is phosphorylated by mTOR to activate de novo lipogenesis. Nat Commun 2020; 11:796. [PMID: 32034158 PMCID: PMC7005700 DOI: 10.1038/s41467-020-14617-1] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Accepted: 01/20/2020] [Indexed: 01/28/2023] Open
Abstract
Fatty acid and triglyceride synthesis increases greatly in response to feeding and insulin. This lipogenic induction involves coordinate transcriptional activation of various enzymes in lipogenic pathway, including fatty acid synthase and glycerol-3-phosphate acyltransferase. Here, we show that JMJD1C is a specific histone demethylase for lipogenic gene transcription in liver. In response to feeding/insulin, JMJD1C is phosphorylated at T505 by mTOR complex to allow direct interaction with USF-1 for recruitment to lipogenic promoter regions. Thus, by demethylating H3K9me2, JMJD1C alters chromatin accessibility to allow transcription. Consequently, JMJD1C promotes lipogenesis in vivo to increase hepatic and plasma triglyceride levels, showing its role in metabolic adaption for activation of the lipogenic program in response to feeding/insulin, and its contribution to development of hepatosteatosis resulting in insulin resistance. In response to insulin, liver cells increase de novo lipogenesis via the transcription factors USF-1 and SREBP. Here the authors show that USF-1 recruits JMJD1C, after its phosphorylation by mTOR, to lipogenic promoters where JMJD1C demethylates histone H3, contributing to lipogenesis by an epigenetic mechanism.
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14
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Costa SO, Souza CM, Lanza PG, Sartori JO, Ignacio-Souza LM, Candreva T, Rodrigues HG, Torsoni AS, Milanski M, Torsoni MA. Maternal high fat diet consumption reduces liver alpha7 nicotinic cholinergic receptor expression and impairs insulin signalling in the offspring. Sci Rep 2020; 10:48. [PMID: 31913329 PMCID: PMC6949221 DOI: 10.1038/s41598-019-56880-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 12/10/2019] [Indexed: 12/14/2022] Open
Abstract
The activation of nicotinic acetylcholine receptor α7 subunit (α7nAChR) has been associated to anti-inflammatory response in macrophages. High-fat diet (HFD) consumption during pregnancy and lactation impairs the cholinergic anti-inflammatory pathway in liver and white adipose tissue of offspring. In order to evaluate the relationship between damage in the cholinergic anti-inflammatory pathway and insulin resistance (IR) development, the liver of offspring of obese dams was investigated. Additionally, the capacity of α7nAChR activation to reduce IR induced by saturated fatty acid was investigated in hepatoma cell line. Initially, female mice were subjected to either standard chow (SC) or HFD during pregnancy and lactation period. After weaning, only male offspring from HFD dams (HFD-O) and SC dams (SC-O) were fed with the SC diet. Hepatic α7nAChR expression was downregulated, and hepatic TNF-α, IL-1β, and pIKK level, but not pJNK, were elevated in the HFD-O compared to SC-O mice. Besides, hepatic expression of TNF-α in response to lipopolysaccharide (LPS) was higher in HFD-O than SC-O mice. Insulin-stimulated phosphorylation of the AKT was lower in HFD-O compared to SC-O. Additionally, insulin-stimulated phosphorylation of the AKT in KOα7Alb-Cre mice fed HFD was lower than WT mice fed HFD. In hepatoma cell line, palmitate increased IL-6 and TNF-α expressions and pJNK level. These effects were accompanied by reduced capacity of insulin to stimulate AKT phosphorylation. PNU or nicotine reduced cytokine expression and JNK activation, but improved insulin resistance induced by palmitate. Our results suggest that maternal obesity impairs hepatic α7nAChR expression and AKT phosphorylation in the offspring. In vitro studies suggest that α7nAChR activation has potential to reduce deleterious effect of saturated fatty acids on insulin signalling.
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Affiliation(s)
- S O Costa
- Laboratory of Metabolic Disorders, School of Applied Sciences, University of Campinas, Campinas, Brazil
| | - C M Souza
- Laboratory of Metabolic Disorders, School of Applied Sciences, University of Campinas, Campinas, Brazil
| | - P G Lanza
- Laboratory of Metabolic Disorders, School of Applied Sciences, University of Campinas, Campinas, Brazil
| | - J O Sartori
- Laboratory of Metabolic Disorders, School of Applied Sciences, University of Campinas, Campinas, Brazil
| | - L M Ignacio-Souza
- Laboratory of Metabolic Disorders, School of Applied Sciences, University of Campinas, Campinas, Brazil.,Obesity and Comorbidities Research Center, University of Campinas, Campinas, Brazil
| | - T Candreva
- Laboratory of Nutrients and Tissue Repair, School of Applied Sciences, University of Campinas, Campinas, Brazil
| | - H G Rodrigues
- Laboratory of Nutrients and Tissue Repair, School of Applied Sciences, University of Campinas, Campinas, Brazil
| | - A S Torsoni
- Laboratory of Metabolic Disorders, School of Applied Sciences, University of Campinas, Campinas, Brazil.,Obesity and Comorbidities Research Center, University of Campinas, Campinas, Brazil
| | - M Milanski
- Laboratory of Metabolic Disorders, School of Applied Sciences, University of Campinas, Campinas, Brazil.,Obesity and Comorbidities Research Center, University of Campinas, Campinas, Brazil
| | - M A Torsoni
- Laboratory of Metabolic Disorders, School of Applied Sciences, University of Campinas, Campinas, Brazil. .,Obesity and Comorbidities Research Center, University of Campinas, Campinas, Brazil.
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15
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Enriched developmental biology molecular pathways impact on antipsychotics-induced weight gain. Pharmacogenet Genomics 2019; 30:9-20. [PMID: 31651721 DOI: 10.1097/fpc.0000000000000390] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Psychotropic-induced weight gain (PIWG) may lead to increased risk for cardiovasculardiseases, metabolic disorders and treatment discontinuation. PIWG may be genetically driven. The analysis of complete molecular pathways may grant suffcient power to tackle the biologic variance of PIWG. Such identifcation would help to move a step forward in the direction of personalized treatment in psychiatry. A genetic sample from the CATIE trial (n = 765; M = 556, mean age = 40.93 ± 11.03) treated with diverse antipsychotic drugs was investigated. A molecular pathway analysis was conducted for the identifcation of the molecular pathways enriched in variations associated with PIWG. The developmental biology molecular pathway was signifcantly (P.adj = 0.018) enriched in genetic variations signifcantly (P < 0.01) associated with PIWG. A total of 18 genes were identifed and discussed. The developmental biology molecular pathway is involved in the regulation of β-cell development, and the transcriptional regulation of white adipocyte differentiation. Results from the current contribution correlate with previous evidence and it is consistent with our earlier result on the STAR*D sample. Furthermore, the involvement of the β-cell development and the transcriptional regulation of white adipocyte differentiation pathways stress the relevance of the peripheral tissue rearrangement, rather than increased food intake, in the biologic modifcations that follow psychotropic treatment and may lead to PIWG. Further research is warranted.
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16
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Sustained ER stress promotes hyperglycemia by increasing glucagon action through the deubiquitinating enzyme USP14. Proc Natl Acad Sci U S A 2019; 116:21732-21738. [PMID: 31594848 DOI: 10.1073/pnas.1907288116] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Endoplasmic reticulum (ER) stress plays an important role in metabolic diseases like obesity and type 2 diabetes mellitus (T2DM), although the underlying mechanisms and regulatory pathways remain to be elucidated. Here, we induced chronic low-grade ER stress in lean mice to levels similar to those in high-fat diet (HFD)-fed obese mice and found that it promoted hyperglycemia due to enhanced hepatic gluconeogenesis. Mechanistically, sustained ER stress up-regulated the deubiquitinating enzyme ubiquitin-specific peptidase 14 (USP14), which increased the stability and levels of 3',5'-cyclic monophosphate-responsive element binding (CREB) protein (CBP) to enhance glucagon action and hepatic gluconeogenesis. Exogenous overexpression of USP14 in the liver significantly increased hepatic glucose output. Consistent with this, liver-specific knockdown of USP14 abrogated the effects of ER stress on glucose metabolism, and also improved hyperglycemia and glucose intolerance in obese mice. In conclusion, our findings show a mechanism underlying ER stress-induced disruption of glucose homeostasis, and present USP14 as a potential therapeutic target against T2DM.
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17
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ELP3 Acetyltransferase is phosphorylated and regulated by the oncogenic anaplastic lymphoma kinase (ALK). Biochem J 2019; 476:2239-2254. [DOI: 10.1042/bcj20190106] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 07/20/2019] [Accepted: 07/23/2019] [Indexed: 12/11/2022]
Abstract
AbstractProtein lysine acetylation is one of the major posttranslational modifications (PTMs) with several thousands of proteins identified to be acetylated in mammalian tissues. Mechanistic studies have revealed important functions of acetylation in the regulation of protein function. Much less is known on how the acetyltransferases themselves are regulated. In the current study, we discover that the Elongator protein 3 (ELP3) acetyltransferase is modified by tyrosine phosphorylation. We demonstrate that the anaplastic lymphoma kinase (ALK) is the major tyrosine kinase responsible for ELP3 tyrosine phosphorylation. ELP3 is phosphorylated in tumor cells expressing oncogenic NPM–ALK fusion protein. We further identify Tyr202 as the major ALK phosphorylation site in ELP3. Importantly, the introduction of Y202 phosphorylation mutant ELP3 into ALK-positive tumor cells reduced cell growth and impaired gene expression. Collectively, our study reveals a novel regulatory mechanism for ELP3, provides an example that acetyltransferase itself can be regulated by PTM, and suggests a potential target for ALK-positive cancer therapies.
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18
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Martins VF, Dent JR, Svensson K, Tahvilian S, Begur M, Lakkaraju S, Buckner EH, LaBarge SA, Hetrick B, McCurdy CE, Schenk S. Germline or inducible knockout of p300 or CBP in skeletal muscle does not alter insulin sensitivity. Am J Physiol Endocrinol Metab 2019; 316:E1024-E1035. [PMID: 30888860 PMCID: PMC6620570 DOI: 10.1152/ajpendo.00497.2018] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Akt is a critical mediator of insulin-stimulated glucose uptake in skeletal muscle. The acetyltransferases, E1A binding protein p300 (p300) and cAMP response element-binding protein binding protein (CBP) are phosphorylated and activated by Akt, and p300/CBP can acetylate and inactivate Akt, thus giving rise to a possible Akt-p300/CBP axis. Our objective was to determine the importance of p300 and CBP to skeletal muscle insulin sensitivity. We used Cre-LoxP methodology to generate mice with germline [muscle creatine kinase promoter (P-MCK and C-MCK)] or inducible [tamoxifen-activated, human skeletal actin promoter (P-iHSA and C-iHSA)] knockout of p300 or CBP. A subset of P-MCK and C-MCK mice were switched to a calorie-restriction diet (60% of ad libitum intake) or high-fat diet at 10 wk of age. For P-iHSA and C-iHSA mice, knockout was induced at 10 wk of age. At 13-15 wk of age, we measured whole-body energy expenditure, oral glucose tolerance, and/or ex vivo skeletal muscle insulin sensitivity. Although p300 and CBP protein abundance and mRNA expression were reduced 55%-90% in p300 and CBP knockout mice, there were no genotype differences in energy expenditure or fasting glucose and insulin concentrations. Moreover, neither loss of p300 or CBP impacted oral glucose tolerance or skeletal muscle insulin sensitivity, nor did their loss impact alterations in these parameters in response to a calorie restriction or high-fat diet. Muscle-specific loss of either p300 or CBP, be it germline or in adulthood, does not impact energy expenditure, glucose tolerance, or skeletal muscle insulin action.
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Affiliation(s)
- Vitor F Martins
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, California
- Biomedical Sciences Graduate Program, University of California, San Diego, La Jolla, California
| | - Jessica R Dent
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, California
| | - Kristoffer Svensson
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, California
| | - Shahriar Tahvilian
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, California
| | - Maedha Begur
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, California
| | - Shivani Lakkaraju
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, California
| | - Elisa H Buckner
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, California
| | - Samuel A LaBarge
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, California
| | - Byron Hetrick
- Department of Human Physiology, University of Oregon , Eugene, Oregon
| | - Carrie E McCurdy
- Department of Human Physiology, University of Oregon , Eugene, Oregon
| | - Simon Schenk
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, California
- Biomedical Sciences Graduate Program, University of California, San Diego, La Jolla, California
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Li X, Chen Y, Shen JZ, Pan Q, Yang W, Yan H, Liu H, Ai W, Liao W, Guo S. Epigallocatechin Gallate Inhibits Hepatic Glucose Production in Primary Hepatocytes via Downregulating PKA Signaling Pathways and Transcriptional Factor FoxO1. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:3651-3661. [PMID: 30875211 DOI: 10.1021/acs.jafc.9b00395] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Forkhead/winged helix transcription factor O-class member 1 (FoxO1) is a key mediator of insulin and glucagon signaling in control of glucose homeostasis. Although epigallocatechin gallate (EGCG) has attracted interest owing to its potential to combat hyperglycemic diabetes, molecular mechanisms underlying its antihyperglycemic effect, in particular the effect on FoxO1, is poorly understand. This study aims to assess the impact of EGCG on the glucagon signaling pathway in regulating glucose metabolism. Primary hepatocytes from wild-type (WT), liver-specific FoxO1 knock out (FKO), and FoxO1-S273D knock-in (KI) mice were isolated, cultured, and treated with EGCG and/or glucagon. Our data showed the treatment of 10 μM EGCG for 6 h decreased hepatic glucose production by 20 and 23% in WT and FKO primary hepatocytes, respectively. EGCG repressed both gluconeogenesis and glycogenolysis in primary hepatocytes, coupled with activating AMPK. In addition, EGCG decreased mitochondrial oxygen consumption. We further investigated the effects of EGCG on glucagon-stimulated cAMP/PKA signaling pathway. EGCG reduced p-PKA-T197/T-PKA and p-CREB-S133/T-CREB levels by 39 and 20%, blocked p-FoxO1-S273, and suppressed nuclear FoxO1 translocation, suggesting that FoxO1 and CREB were possible downstream targets. A novel mechanism of EGCG in restraining hepatic glucose production (HGP) is through antagonizing glucagon signaling and suppressing FoxO1 via Ser273. EGCG may serve as a promising compound for regulating glucose homeostasis.
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Affiliation(s)
- Xiaopeng Li
- Department of Nutrition and Food Science, College of Agriculture and Life Science , Texas A&M University , College Station , Texas 77843 , United States
- College of Food Science and Technology , Huazhong Agricultural University , Wuhan 430070 , China
| | - Yunmei Chen
- Department of Nutrition and Food Science, College of Agriculture and Life Science , Texas A&M University , College Station , Texas 77843 , United States
- School of Medicine and Pharmacy , Ocean University of China , Qingdao 266003 , China
| | - James Zheng Shen
- Department of Nutrition and Food Science, College of Agriculture and Life Science , Texas A&M University , College Station , Texas 77843 , United States
| | - Quan Pan
- Department of Nutrition and Food Science, College of Agriculture and Life Science , Texas A&M University , College Station , Texas 77843 , United States
| | - Wanbao Yang
- Department of Nutrition and Food Science, College of Agriculture and Life Science , Texas A&M University , College Station , Texas 77843 , United States
| | - Hui Yan
- Department of Nutrition and Food Science, College of Agriculture and Life Science , Texas A&M University , College Station , Texas 77843 , United States
| | - Huimin Liu
- Department of Nutrition and Food Science, College of Agriculture and Life Science , Texas A&M University , College Station , Texas 77843 , United States
| | - Weiqi Ai
- Department of Nutrition and Food Science, College of Agriculture and Life Science , Texas A&M University , College Station , Texas 77843 , United States
| | - Wang Liao
- Department of Nutrition and Food Science, College of Agriculture and Life Science , Texas A&M University , College Station , Texas 77843 , United States
| | - Shaodong Guo
- Department of Nutrition and Food Science, College of Agriculture and Life Science , Texas A&M University , College Station , Texas 77843 , United States
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20
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Interleukin-4 Boosts Insulin-Induced Energy Deposits by Enhancing Glucose Uptake and Lipogenesis in Hepatocytes. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:6923187. [PMID: 30584465 PMCID: PMC6280305 DOI: 10.1155/2018/6923187] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2018] [Revised: 08/14/2018] [Accepted: 09/06/2018] [Indexed: 12/20/2022]
Abstract
Type 2 diabetes mellitus (T2DM), with dysregulated hepatic gluconeogenesis as the major cause of fasting hyperglycemia, is closely associated with chronic inflammation. We previously demonstrated interleukin-4 (IL-4) improves insulin sensitivity and glucose tolerance while reducing lipid deposits. The present study examined the in vitro effects of IL-4 on insulin signaling molecules, glucose uptake, and lipid metabolism in hepatocytes, as well as in vivo effects on hepatic adiposity, for elucidating the roles of IL-4 in hepatic energy metabolism. Potential interaction between IL-4 and insulin in regulating hepatic metabolism was also investigated. Our results showed that IL-4 enhanced Akt and GSK-3α/β phosphorylations, which in turn promoted glycogen synthesis. IL-4 not only potentiated basal glucose uptake by upregulating glucose transporter 2 expression but also promoted insulin-induced glucose uptake. Additionally, IL-4 increased triglyceride contents through facilitating free fatty acid uptake and expression/activity of lipogenic enzymes. The major effects of IL-4 on the liver were to promote energy storage by boosting insulin-stimulated glucose uptake and lipid synthesis. This study provides evidence to implicate the novel roles of IL-4 in mediating hepatic glucose and lipid metabolism, interactions between immune responses and metabolic homeostasis, and the involvement of IL-4 in metabolic abnormalities.
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21
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Kaspi A, Khurana I, Ziemann M, Connor T, Spolding B, Zimmet P, Walder K, El-Osta A. Diet during Pregnancy is Implicated in the Regulation of Hypothalamic RNA Methylation and Risk of Obesity in Offspring. Mol Nutr Food Res 2018; 62:e1800134. [PMID: 29882289 DOI: 10.1002/mnfr.201800134] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2018] [Revised: 05/07/2018] [Indexed: 01/24/2023]
Abstract
SCOPE Early life nutrition has long-lasting influence in adults through key mediators that modulate epigenetic states, although the determinants involved that underlie this response remain controversial. Because of the similarities between metabolic, physiological, and endocrine changes and those occurring in human type 2 diabetes, we studied the interaction of diet during pregnancy regulating RNA adenosine methylation (N6-methyladenosine [m6A]) and the transcriptome in Psammomys obesus. METHODS AND RESULTS Breeding pairs were randomly allocated standard diet (total digestible energy 18 MJ kg-1 ) or low-fat diet (15 MJ kg-1 ). Offspring were weaned onto the low-fat diet at 4 weeks of age and given ad libitum access, resulting in two experimental groups: 1) male offspring of animals fed a low-fat diet and weaned onto the low-fat diet and 2) male offspring of animals fed a standard diet and weaned onto the low-fat diet. Hypothalamic RNA was used to assess m6A by immunoprecipitation. Parental low-fat diet alters the metabolic phenotype in offspring. An association between parental diet and hypothalamic m6A was observed in regulating the expression of FTO and METTL3 in the offspring. CONCLUSIONS We propose the regulatory capacity is now broadened for the first time to include m6A in developmental programming and obesity phenotype.
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Affiliation(s)
- Antony Kaspi
- Central Clinical School, Faculty of Medicine, Monash University, Victoria, 3004, Australia.,Baker IDI Heart and Diabetes Institute, The Alfred Medical Research and Education Precinct, Melbourne, Victoria, 3004, Australia
| | - Ishant Khurana
- Central Clinical School, Faculty of Medicine, Monash University, Victoria, 3004, Australia.,Baker IDI Heart and Diabetes Institute, The Alfred Medical Research and Education Precinct, Melbourne, Victoria, 3004, Australia
| | - Mark Ziemann
- Central Clinical School, Faculty of Medicine, Monash University, Victoria, 3004, Australia.,Baker IDI Heart and Diabetes Institute, The Alfred Medical Research and Education Precinct, Melbourne, Victoria, 3004, Australia
| | - Timothy Connor
- Metabolic Research Unit, Faculty of Health, Medicine, Nursing and Behavioral Sciences, Deakin University, Waurn Ponds, Victoria, 3216, Australia
| | - Briana Spolding
- Metabolic Research Unit, Faculty of Health, Medicine, Nursing and Behavioral Sciences, Deakin University, Waurn Ponds, Victoria, 3216, Australia
| | - Paul Zimmet
- Central Clinical School, Faculty of Medicine, Monash University, Victoria, 3004, Australia
| | - Ken Walder
- Metabolic Research Unit, Faculty of Health, Medicine, Nursing and Behavioral Sciences, Deakin University, Waurn Ponds, Victoria, 3216, Australia
| | - Assam El-Osta
- Central Clinical School, Faculty of Medicine, Monash University, Victoria, 3004, Australia.,Baker IDI Heart and Diabetes Institute, The Alfred Medical Research and Education Precinct, Melbourne, Victoria, 3004, Australia.,Department of Pathology, University of Melbourne, Parkville, Victoria, 3004, Australia.,Hong Kong Institute of Diabetes and Obesity, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong SAR
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22
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Yadav DK, Shrestha S, Lillycrop KA, Joglekar CV, Pan H, Holbrook JD, Fall CH, Yajnik CS, Chandak GR. Vitamin B 12 supplementation influences methylation of genes associated with Type 2 diabetes and its intermediate traits. Epigenomics 2017; 10:71-90. [PMID: 29135286 DOI: 10.2217/epi-2017-0102] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
AIM To investigate the effect of B12 and/or folic acid supplementation on genome-wide DNA methylation. METHODS We performed Infinium HumanMethylation450 BeadChip (Zymo Research, CA, USA) assay in children supplemented with B12 and/or folic acid (n = 12 in each group) and investigated the functional mechanism of selected differentially methylated loci. RESULTS We noted significant methylation changes postsupplementation in B12 (589 differentially methylated CpGs and 2892 regions) and B12 + folic acid (169 differentially methylated CpGs and 3241 regions) groups. Type 2 diabetes-associated genes TCF7L2 and FTO; and a miRNA, miR21 were further investigated in another B12-supplementation cohort. We also demonstrate that methylation influences miR21 expression and FTO, TCF7L2, CREBBP/CBP and SIRT1 are direct targets of miR21-3p. CONCLUSION B12 supplementation influences regulation of several metabolically important Type 2 diabetes-associated genes through methylation of miR21. Hence, our study provides novel epigenetic explanation for the association between disordered one carbon metabolism and risk of adiposity, insulin resistance and diabetes and has translational potential.
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Affiliation(s)
- Dilip K Yadav
- Genomic Research on Complex Diseases (GRC Group), CSIR-Centre for Cellular & Molecular Biology, Hyderabad, Telangana, 500 007, India
| | - Smeeta Shrestha
- Genomic Research on Complex Diseases (GRC Group), CSIR-Centre for Cellular & Molecular Biology, Hyderabad, Telangana, 500 007, India.,Building No 7, School of Basic & Applied Sciences, Dayananda Sagar University, Shavige Malleshwara Hills, Kumaraswamy Layout, Bangalore 560 078, Karnataka, India
| | - Karen A Lillycrop
- Research Centre for Biological Sciences, Institute of Developmental Sciences, Southampton General Hospital, Southampton, SO16 6 YD, UK
| | - Charu V Joglekar
- Diabetes Unit, King Edward Memorial Hospital & Research Centre, Rasta Peth, Pune, Maharashtra, 411 011, India
| | - Hong Pan
- Singapore Institute for Clinical Sciences, A*STAR, Brenner Centre for Molecular Medicine, 30 Medical Drive, 119521, Singapore
| | - Joanna D Holbrook
- Singapore Institute for Clinical Sciences, A*STAR, Brenner Centre for Molecular Medicine, 30 Medical Drive, 119521, Singapore.,Human Development & Health Academic Unit, University of Southampton & National Institute for Health Research Southampton Biomedical Research Centre, University of Southampton & University Hospital Southampton NHS Foundation Trust, Tremona Road, Southampton, SO16 6 YD, UK
| | - Caroline Hd Fall
- MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton General Hospital, Southampton, SO16 6 YD, UK
| | - Chittaranjan S Yajnik
- Diabetes Unit, King Edward Memorial Hospital & Research Centre, Rasta Peth, Pune, Maharashtra, 411 011, India
| | - Giriraj R Chandak
- Genomic Research on Complex Diseases (GRC Group), CSIR-Centre for Cellular & Molecular Biology, Hyderabad, Telangana, 500 007, India.,Adjunct Faculty, Human Genetics Unit, Genome Institute of Singapore, Biopolis, 138672, Singapore
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23
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The high-production volume fungicide pyraclostrobin induces triglyceride accumulation associated with mitochondrial dysfunction, and promotes adipocyte differentiation independent of PPARγ activation, in 3T3-L1 cells. Toxicology 2017; 393:150-159. [PMID: 29127035 DOI: 10.1016/j.tox.2017.11.010] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 10/27/2017] [Accepted: 11/06/2017] [Indexed: 12/25/2022]
Abstract
Pyraclostrobin is one of the most heavily used fungicides, and has been detected on a variety of produce, suggesting human exposure occurs regularly. Recently, pyraclostrobin exposure has been linked to a variety of toxic effects, including neurodegeneration and triglyceride (TG) accumulation. As pyraclostrobin inhibits electron transport chain complex III, and as mitochondrial dysfunction is associated with metabolic syndrome (cardiovascular disease, type II diabetes, obesity), we designed experiments to test the hypothesis that mitochondrial dysfunction underlies its adipogenic activity. 3T3-L1 cells were differentiated according to standard protocols in the presence of pyraclostrobin, resulting in TG accumulation. However, TG accumulation occurred without activation of the peroxisome proliferator activated nuclear receptor gamma (PPARγ), the canonical pathway mediating adipogenesis. Furthermore, cells failed to express many markers of adipogenesis (PPARγ, lpl, CEBPα), while co-exposure to pyraclostrobin and two different PPARγ antagonists (GW9662, T0070907) failed to mitigate TG accumulation, suggesting TG accumulation occurred through a PPARγ-independent mechanism. Instead, pyraclostrobin reduced steady-state ATP, mitochondrial membrane potential, basal mitochondrial respiration, ATP-linked respiration, and spare respiratory capacity, demonstrating mitochondrial dysfunction, while reduced expression of genes involved in glucose transport (Glut-4), glycolysis (Pkm, Pfkl, Pfkm), fatty acid oxidation (Cpt-1b), and lipogenesis (Fasn, Acacα, Acacβ) further suggested a disruption of metabolism. Finally, inhibition of cAMP responsive element binding protein (CREB), a PPARγ coactivator, partially mitigated pyraclostrobin-induced TG accumulation, suggesting TG accumulation is occurring through a CREB-driven mechanism. In contrast, rosiglitazone, a known PPARγ agonist, induced TG accumulation in a PPARγ-dependent manner and enhanced mitochondrial function. Collectively, these results suggest pyraclostrobin-induced mitochondrial dysfunction inhibits lipid homeostasis, resulting in TG accumulation. Exposures that disrupt mitochondrial function may have the potential to contribute to the rising incidence of metabolic syndrome, and thus more research is needed to understand the human health impact of pyraclostrobin exposure.
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24
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GCN5L1 modulates cross-talk between mitochondria and cell signaling to regulate FoxO1 stability and gluconeogenesis. Nat Commun 2017; 8:523. [PMID: 28900165 PMCID: PMC5595826 DOI: 10.1038/s41467-017-00521-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 07/04/2017] [Indexed: 01/21/2023] Open
Abstract
The mitochondrial enriched GCN5-like 1 (GCN5L1) protein has been shown to modulate mitochondrial protein acetylation, mitochondrial content and mitochondrial retrograde signaling. Here we show that hepatic GCN5L1 ablation reduces fasting glucose levels and blunts hepatic gluconeogenesis without affecting systemic glucose tolerance. PEPCK and G6Pase transcript levels are downregulated in hepatocytes from GCN5L1 liver specific knockout mice and their upstream regulator, FoxO1 protein levels are decreased via proteasome-dependent degradation and via reactive oxygen species mediated ERK-1/2 phosphorylation. ERK inhibition restores FoxO1, gluconeogenic enzyme expression and glucose production. Reconstitution of mitochondrial-targeted GCN5L1 blunts mitochondrial ROS, ERK activation and increases FoxO1, gluconeogenic enzyme expression and hepatocyte glucose production. We suggest that mitochondrial GCN5L1 modulates post-translational control of FoxO1, regulates gluconeogenesis and controls metabolic pathways via mitochondrial ROS mediated ERK activation. Exploring mechanisms underpinning GCN5L1 mediated ROS signaling may expand our understanding of the role of mitochondria in gluconeogenesis control.Hepatic gluconeogenesis is tightly regulated at transcriptional level and is essential for survival during prolonged fasting. Here Wang et al. show that the mitochondrial enriched GCN5-like 1 protein controls hepatic glucose production by regulating FoxO1 protein levels via proteasome-dependent degradation and, in turn, gluconeogenic gene expression.
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25
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Hatting M, Tavares CDJ, Sharabi K, Rines AK, Puigserver P. Insulin regulation of gluconeogenesis. Ann N Y Acad Sci 2017; 1411:21-35. [PMID: 28868790 DOI: 10.1111/nyas.13435] [Citation(s) in RCA: 296] [Impact Index Per Article: 42.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 06/16/2017] [Accepted: 06/26/2017] [Indexed: 12/11/2022]
Abstract
The coordinated regulation between cellular glucose uptake and endogenous glucose production is indispensable for the maintenance of constant blood glucose concentrations. The liver contributes significantly to this process by altering the levels of hepatic glucose release, through controlling the processes of de novo glucose production (gluconeogenesis) and glycogen breakdown (glycogenolysis). Various nutritional and hormonal stimuli signal to alter hepatic gluconeogenic flux, and suppression of this metabolic pathway during the postprandial state can, to a significant extent, be attributed to insulin. Here, we review some of the molecular mechanisms through which insulin modulates hepatic gluconeogenesis, thus controlling glucose production by the liver to ultimately maintain normoglycemia. Various signaling pathways governed by insulin converge at the level of transcriptional regulation of the key hepatic gluconeogenic genes PCK1 and G6PC, highlighting this as one of the focal mechanisms through which gluconeogenesis is modulated. In individuals with compromised insulin signaling, such as insulin resistance in type 2 diabetes, insulin fails to suppress hepatic gluconeogenesis, even in the fed state; hence, an insight into these insulin-moderated pathways is critical for therapeutic purposes.
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Affiliation(s)
- Maximilian Hatting
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts.,Department of Cell Biology, Harvard Medical School, Boston, Massachusetts
| | - Clint D J Tavares
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts.,Department of Cell Biology, Harvard Medical School, Boston, Massachusetts
| | - Kfir Sharabi
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts.,Department of Cell Biology, Harvard Medical School, Boston, Massachusetts
| | - Amy K Rines
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts.,Department of Cell Biology, Harvard Medical School, Boston, Massachusetts
| | - Pere Puigserver
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts.,Department of Cell Biology, Harvard Medical School, Boston, Massachusetts
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26
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Li Y, Wang L, Zhou L, Song Y, Ma S, Yu C, Zhao J, Xu C, Gao L. Thyroid stimulating hormone increases hepatic gluconeogenesis via CRTC2. Mol Cell Endocrinol 2017; 446:70-80. [PMID: 28212844 DOI: 10.1016/j.mce.2017.02.015] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Revised: 02/09/2017] [Accepted: 02/10/2017] [Indexed: 10/20/2022]
Abstract
Epidemiological evidence indicates that thyroid stimulating hormone (TSH) is positively correlated with abnormal glucose levels. We previously reported that TSH has direct effects on gluconeogenesis. However, the underlying molecular mechanism remains unclear. In this study, we observed increased fasting blood glucose and glucose production in a mouse model of subclinical hypothyroidism (only elevated TSH levels). TSH acts via the classical cAMP/PKA pathway and CRTC2 regulates glucose homeostasis. Thus, we explore whether CRTC2 is involved in the process of TSH-induced gluconeogenesis. We show that TSH increases CRTC2 expression via the TSHR/cAMP/PKA pathway, which in turn upregulates hepatic gluconeogenic genes. Furthermore, TSH stimulates CRTC2 dephosphorylation and upregulates p-CREB (Ser133) in HepG2 cells. Silencing CRTC2 and CREB decreases the effect of TSH on PEPCK-luciferase, the rate-limiting enzyme of gluconeogenesis. Finally, the deletion of TSHR reduces the levels of the CRTC2:CREB complex in mouse livers. This study demonstrates that TSH activates CRTC2 via the TSHR/cAMP/PKA pathway, leading to the formation of a CRTC2:CREB complex and increases hepatic gluconeogenesis.
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Affiliation(s)
- Yujie Li
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong University, Shandong Clinical Medical Center of Endocrinology and Metabolism, Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, 324 Jing 5 Rd Jinan, Shandong 250021, PR China
| | - Laicheng Wang
- Scientific Center, Shandong Provincial Hospital Affiliated to Shandong University, 544 Jing 4 Rd Jinan, Shangdong 250021, PR China
| | - Lingyan Zhou
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong University, Shandong Clinical Medical Center of Endocrinology and Metabolism, Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, 324 Jing 5 Rd Jinan, Shandong 250021, PR China
| | - Yongfeng Song
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong University, Shandong Clinical Medical Center of Endocrinology and Metabolism, Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, 324 Jing 5 Rd Jinan, Shandong 250021, PR China
| | - Shizhan Ma
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong University, Shandong Clinical Medical Center of Endocrinology and Metabolism, Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, 324 Jing 5 Rd Jinan, Shandong 250021, PR China
| | - Chunxiao Yu
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong University, Shandong Clinical Medical Center of Endocrinology and Metabolism, Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, 324 Jing 5 Rd Jinan, Shandong 250021, PR China
| | - Jiajun Zhao
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong University, Shandong Clinical Medical Center of Endocrinology and Metabolism, Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, 324 Jing 5 Rd Jinan, Shandong 250021, PR China
| | - Chao Xu
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong University, Shandong Clinical Medical Center of Endocrinology and Metabolism, Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, 324 Jing 5 Rd Jinan, Shandong 250021, PR China.
| | - Ling Gao
- Institute of Endocrinology, Shandong Academy of Clinical Medicine, Scientific Center, Shandong Provincial Hospital Affiliated to Shandong University, 544 Jing 4 Rd Jinan, Shangdong 250021, PR China.
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27
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Li X. Emerging role of mutations in epigenetic regulators including MLL2 derived from The Cancer Genome Atlas for cervical cancer. BMC Cancer 2017; 17:252. [PMID: 28390392 PMCID: PMC5385072 DOI: 10.1186/s12885-017-3257-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 04/01/2017] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Cervical cancer is the second most common cause of cancer deaths in women worldwide. The aim of this study is to exploit novel pathogenic genes in cervical carcinogenesis. METHOD The somatic mutations from 194 patients with cervical cancer were obtained from the Cancer Genome Atlas (TCGA) publically accessible exome-sequencing database. We investigated mutated gene enrichment in the 12 cancer core pathways and predicted possible post-translational modifications. Additionally, we predicted the impact of mutations by scores quantifying the deleterious effects of the mutations. We also examined the immunogenicity of the mutations based on the mutant peptides' strong binding with major histocompatibility complex class I molecules (MHC-I). The Kaplan-Meier method was used for the survival analysis. RESULTS We observed that the chromatin modification pathway was significantly mutated across all clinical stages. Among the mutated genes involved in this pathway, we observed that the histone modification regulators were primarily mutated. Interestingly, of the 197 mutations in the 26 epigenetic regulators in this pathway, 25 missense mutations in 13 genes were predicted in or around the phosphorylation sites. Only mutations in the histone methyltransferase MLL2 exhibited poor survival. Compared to other mutations in MLL2 mutant patients, we noticed that the mutational scores prioritized mutations in MLL2, which indicates that it is more likely to have deleterious effects to the human genome. Around half of all of the mutations were found to bind strongly to MHC-I, suggesting that patients are likely to benefit from immunotherapy. CONCLUSIONS Our results highlight the emerging role of mutations in epigenetic regulators, particularly MLL2, in cervical carcinogenesis, which suggests a potential disruption of histone modifications. These data have implications for further investigation of the mechanism of epigenetic dysregulation and for treatment of cervical cancer.
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Affiliation(s)
- Xia Li
- Research Center for Biomedical Information Technology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, People's Republic of China.
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28
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Weber C, Schäff C, Kautzsch U, Börner S, Erdmann S, Bruckmaier R, Röntgen M, Kuhla B, Hammon H. Variable liver fat concentration as a proxy for body fat mobilization postpartum has minor effects on insulin-induced changes in hepatic gene expression related to energy metabolism in dairy cows. J Dairy Sci 2017; 100:1507-1520. [DOI: 10.3168/jds.2016-11808] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 11/07/2016] [Indexed: 12/11/2022]
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29
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The aPKC-CBP Pathway Regulates Adult Hippocampal Neurogenesis in an Age-Dependent Manner. Stem Cell Reports 2016; 7:719-734. [PMID: 27618724 PMCID: PMC5063627 DOI: 10.1016/j.stemcr.2016.08.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Revised: 08/10/2016] [Accepted: 08/11/2016] [Indexed: 11/20/2022] Open
Abstract
While epigenetic modifications have emerged as attractive substrates to integrate environmental changes into the determination of cell identity and function, specific signals that directly activate these epigenetic modifications remain unknown. Here, we examine the role of atypical protein kinase C (aPKC)-mediated Ser436 phosphorylation of CBP, a histone acetyltransferase, in adult hippocampal neurogenesis and memory. Using a knockin mouse strain (CbpS436A) in which the aPKC-CBP pathway is deficient, we observe impaired hippocampal neuronal differentiation, maturation, and memory and diminished binding of CBP to CREB in 6-month-old CbpS436A mice, but not at 3 months of age. Importantly, elevation of CREB activity rescues these deficits, and CREB activity is reduced whereas aPKC activity is increased in the murine hippocampus as they age from 3 to 6 months regardless of genotype. Thus, the aPKC-CBP pathway is a homeostatic compensatory mechanism that modulates hippocampal neurogenesis and memory in an age-dependent manner in response to reduced CREB activity. The aPKC-CBP pathway maintains mature adult hippocampal neuronal differentiation The aPKC-CBP pathway is required for hippocampal-dependent memory in mature adult The aPKC-CBP pathway is required for CBP binding to CREB in mature adult hippocampi Increased CREB activity rescues the deficits due to the deficient aPKC-CBP pathway
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30
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Domankevich V, Opatowsky Y, Malik A, Korol AB, Frenkel Z, Manov I, Avivi A, Shams I. Adaptive patterns in the p53 protein sequence of the hypoxia- and cancer-tolerant blind mole rat Spalax. BMC Evol Biol 2016; 16:177. [PMID: 27590526 PMCID: PMC5010716 DOI: 10.1186/s12862-016-0743-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 08/17/2016] [Indexed: 12/19/2022] Open
Abstract
Background The subterranean blind mole rat, Spalax (genus Nannospalax) endures extreme hypoxic conditions and fluctuations in oxygen levels that threaten DNA integrity. Nevertheless, Spalax is long-lived, does not develop spontaneous cancer, and exhibits an outstanding resistance to carcinogenesis in vivo, as well as anti-cancer capabilities in vitro. We hypothesized that adaptations to similar extreme environmental conditions involve common mechanisms for overcoming stress-induced DNA damage. Therefore, we aimed to identify shared features among species that are adapted to hypoxic stress in the sequence of the tumor-suppressor protein p53, a master regulator of the DNA-damage response (DDR). Results We found that the sequences of p53 transactivation subdomain 2 (TAD2) and tetramerization and regulatory domains (TD and RD) are more similar among hypoxia-tolerant species than expected from phylogeny. Specific positions in these domains composed patterns that are more frequent in hypoxia-tolerant species and have proven to be good predictors of species’ classification into stress-related categories. Some of these positions, which are known to be involved in the interactions between p53 and critical DDR proteins, were identified as positively selected. By 3D modeling of p53 interactions with the coactivator p300 and the DNA repair protein RPA70, we demonstrated that, compared to humans, these substitutions potentially reduce the binding of these proteins to Spalax p53. Conclusions We conclude that extreme hypoxic conditions may have led to convergent evolutionary adaptations of the DDR via TAD2 and TD/RD domains of p53. Electronic supplementary material The online version of this article (doi:10.1186/s12862-016-0743-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Vered Domankevich
- Institute of Evolution & Department of Evolutionary and Environmental Biology, University of Haifa, Haifa, Israel
| | - Yarden Opatowsky
- Mina and Everard Goodman Faculty of Life Sciences and Advanced Materials and Nanotechnology Institute, Bar-Ilan University, Ramat-Gan, Israel
| | - Assaf Malik
- Institute of Evolution & Department of Evolutionary and Environmental Biology, University of Haifa, Haifa, Israel
| | - Abraham B Korol
- Institute of Evolution & Department of Evolutionary and Environmental Biology, University of Haifa, Haifa, Israel
| | - Zeev Frenkel
- Institute of Evolution & Department of Evolutionary and Environmental Biology, University of Haifa, Haifa, Israel
| | - Irena Manov
- Institute of Evolution & Department of Evolutionary and Environmental Biology, University of Haifa, Haifa, Israel
| | - Aaron Avivi
- Institute of Evolution & Department of Evolutionary and Environmental Biology, University of Haifa, Haifa, Israel
| | - Imad Shams
- Institute of Evolution & Department of Evolutionary and Environmental Biology, University of Haifa, Haifa, Israel.
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Pandey G, Shankar K, Makhija E, Gaikwad A, Ecelbarger C, Mandhani A, Srivastava A, Tiwari S. Reduced Insulin Receptor Expression Enhances Proximal Tubule Gluconeogenesis. J Cell Biochem 2016; 118:276-285. [PMID: 27322100 DOI: 10.1002/jcb.25632] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 06/16/2016] [Indexed: 12/18/2022]
Abstract
Reduced insulin receptor protein levels have been reported in the kidney cortex from diabetic humans and animals. We recently reported that, targeted deletion of insulin receptor (IR) from proximal tubules (PT) resulted in hyperglycemia in non-obese mice. To elucidate the mechanism, we examined human proximal tubule cells (hPTC) and C57BL/6 mice fed with high-fat diet (HFD, 60% fat for 20 weeks). Immunoblotting revealed a significantly lower protein level of IR in HFD compare to normal chow diet (NCD). Furthermore, a blunted rise in p-AKT308 levels in the kidney cortex of HFD mice was observed in response to acute insulin (0.75 IU/kg body weight, i.p) relative to NCD n = 8/group, P < 0.05). Moreover, we found significantly higher transcript levels of phosphoenolpyruvate carboxykinase (PEPCK, a key gluconeogenic enzyme) in the kidney cortex from HFD, relative to mice on NCD. The higher level of PEPCK in HFD was confirmed by immunoblotting. However, no significant differences were observed in cortical glucose-6-phosphatase (G6Pase) or fructose-1,6, bisphosphosphatase (FBPase) enzyme transcript levels. Furthermore, we demonstrated insulin inhibited glucose production in hPTC treated with cyclic AMP and dexamethasone (cAMP/DEXA) to stimulate gluconeogenesis. Transcript levels of the gluconeogenic enzyme PEPCK were significantly increased in cAMP/DEXA-stimulated hPTC cells (n = 3, P < 0.05), and insulin attenuated this upregulation Furthermore, the effect of insulin on cAMP/DEXA-induced gluconeogenesis and PEPCK induction was significantly attenuated in IR (siRNA) silenced hPTC (n = 3, P < 0.05). Overall the above data indicate a direct role for IR expression as a determinant of PT-gluconeogenesis. Thus reduced insulin signaling of the proximal tubule may contribute to hyperglycemia in the metabolic syndrome via elevated gluconeogenesis. J. Cell. Biochem. 118: 276-285, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Gaurav Pandey
- Department of Molecular Medicine and Biotechnology, SGPGIMS, Lucknow, 226014, India
| | | | - Ekta Makhija
- Department of Molecular Medicine and Biotechnology, SGPGIMS, Lucknow, 226014, India
| | | | - Carolyn Ecelbarger
- Department of Medicine, Georgetown University, Washington, District of Columbia
| | | | | | - Swasti Tiwari
- Department of Molecular Medicine and Biotechnology, SGPGIMS, Lucknow, 226014, India.,Department of Medicine, Georgetown University, Washington, District of Columbia
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Association of genetic risk scores with body mass index in Swiss psychiatric cohorts. Pharmacogenet Genomics 2016; 26:208-17. [DOI: 10.1097/fpc.0000000000000210] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Expression of epigenetic machinery genes is sensitive to maternal obesity and weight loss in relation to fetal growth in mice. Clin Epigenetics 2016; 8:22. [PMID: 26925174 PMCID: PMC4769534 DOI: 10.1186/s13148-016-0188-3] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 02/12/2016] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Maternal obesity impacts fetal growth and pregnancy outcomes. To counteract the deleterious effects of obesity on fertility and pregnancy issue, preconceptional weight loss is recommended to obese women. Whether this weight loss is beneficial/detrimental for offspring remains poorly explored. Epigenetic mechanisms could be affected by maternal weight changes, perturbing expression of key developmental genes in the placenta or fetus. Our aim was to investigate the effects of chronic maternal obesity on feto-placental growth along with the underlying epigenetic mechanisms. We also tested whether preconceptional weight loss could alleviate these effects. RESULTS Female mice were fed either a control diet (CTRL group), a high-fat diet (obese (OB) group), or a high-fat diet switched to a control diet 2 months before conception (weight loss (WL) group). At mating, OB females presented an obese phenotype while WL females normalized metabolic parameters. At embryonic day 18.5 (E18.5), fetuses from OB females presented fetal growth restriction (FGR; -13 %) and 28 % of the fetuses were small for gestational age (SGA). Fetuses from WL females normalized this phenotype. The expression of 60 epigenetic machinery genes and 32 metabolic genes was measured in the fetal liver, placental labyrinth, and junctional zone. We revealed 23 genes altered by maternal weight trajectories in at least one of three tissues. The fetal liver and placental labyrinth were more responsive to maternal obesity than junctional zone. One third (18/60) of the epigenetic machinery genes were differentially expressed between at least two maternal groups. Interestingly, genes involved in the histone acetylation pathway were particularly altered (13/18). In OB group, lysine acetyltransferases and Bromodomain-containing protein 2 were upregulated, while most histone deacetylases were downregulated. In WL group, the expression of only a subset of these genes was normalized. CONCLUSIONS This study highlights the high sensitivity of the epigenetic machinery gene expression, and particularly the histone acetylation pathway, to maternal obesity. These obesity-induced transcriptional changes could alter the placental and the hepatic epigenome, leading to FGR. Preconceptional weight loss appears beneficial to fetal growth, but some effects of previous obesity were retained in offspring phenotype.
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Lee JM, Seo WY, Han HS, Oh KJ, Lee YS, Kim DK, Choi S, Choi BH, Harris RA, Lee CH, Koo SH, Choi HS. Insulin-Inducible SMILE Inhibits Hepatic Gluconeogenesis. Diabetes 2016; 65:62-73. [PMID: 26340929 DOI: 10.2337/db15-0249] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 08/26/2015] [Indexed: 11/13/2022]
Abstract
The role of a glucagon/cAMP-dependent protein kinase-inducible coactivator PGC-1α signaling pathway is well characterized in hepatic gluconeogenesis. However, an opposing protein kinase B (PKB)/Akt-inducible corepressor signaling pathway is unknown. A previous report has demonstrated that small heterodimer partner-interacting leucine zipper protein (SMILE) regulates the nuclear receptors and transcriptional factors that control hepatic gluconeogenesis. Here, we show that hepatic SMILE expression was induced by feeding in normal mice but not in db/db and high-fat diet (HFD)-fed mice. Interestingly, SMILE expression was induced by insulin in mouse primary hepatocyte and liver. Hepatic SMILE expression was not altered by refeeding in liver-specific insulin receptor knockout (LIRKO) or PKB β-deficient (PKBβ(-/-)) mice. At the molecular level, SMILE inhibited hepatocyte nuclear factor 4-mediated transcriptional activity via direct competition with PGC-1α. Moreover, ablation of SMILE augmented gluconeogenesis and increased blood glucose levels in mice. Conversely, overexpression of SMILE reduced hepatic gluconeogenic gene expression and ameliorated hyperglycemia and glucose intolerance in db/db and HFD-fed mice. Therefore, SMILE is an insulin-inducible corepressor that suppresses hepatic gluconeogenesis. Small molecules that enhance SMILE expression would have potential for treating hyperglycemia in diabetes.
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Affiliation(s)
- Ji-Min Lee
- National Creative Research Initiatives Center for Nuclear Receptor Signals and Hormone Research Center, School of Biological Sciences and Technology, Chonnam National University, Gwangju, Republic of Korea
| | - Woo-Young Seo
- Division of Life Sciences, College of Life Sciences and Biotechnology, Korea University, Seoul, Republic of Korea
| | - Hye-Sook Han
- Division of Life Sciences, College of Life Sciences and Biotechnology, Korea University, Seoul, Republic of Korea
| | - Kyoung-Jin Oh
- Division of Life Sciences, College of Life Sciences and Biotechnology, Korea University, Seoul, Republic of Korea
| | - Yong-Soo Lee
- National Creative Research Initiatives Center for Nuclear Receptor Signals and Hormone Research Center, School of Biological Sciences and Technology, Chonnam National University, Gwangju, Republic of Korea
| | - Don-Kyu Kim
- National Creative Research Initiatives Center for Nuclear Receptor Signals and Hormone Research Center, School of Biological Sciences and Technology, Chonnam National University, Gwangju, Republic of Korea
| | - Seri Choi
- Division of Life Sciences, College of Life Sciences and Biotechnology, Korea University, Seoul, Republic of Korea
| | - Byeong Hun Choi
- Division of Life Sciences, College of Life Sciences and Biotechnology, Korea University, Seoul, Republic of Korea
| | - Robert A Harris
- Richard Roudebush Veterans Affairs Medical Center and Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN
| | - Chul-Ho Lee
- Korea Research Institute of Bioscience and Biotechnology, Daejeon, Republic of Korea
| | - Seung-Hoi Koo
- Division of Life Sciences, College of Life Sciences and Biotechnology, Korea University, Seoul, Republic of Korea
| | - Hueng-Sik Choi
- National Creative Research Initiatives Center for Nuclear Receptor Signals and Hormone Research Center, School of Biological Sciences and Technology, Chonnam National University, Gwangju, Republic of Korea
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Abstract
Reversible acetylation was initially described as an epigenetic mechanism regulating DNA accessibility. Since then, this process has emerged as a controller of histone and nonhistone acetylation that integrates key physiological processes such as metabolism, circadian rhythm and cell cycle, along with gene regulation in various organisms. The widespread and reversible nature of acetylation also revitalized interest in the mechanisms that regulate lysine acetyltransferases (KATs) and deacetylases (KDACs) in health and disease. Changes in protein or histone acetylation are especially relevant for many common diseases including obesity, diabetes mellitus, neurodegenerative diseases and cancer, as well as for some rare diseases such as mitochondrial diseases and lipodystrophies. In this Review, we examine the role of reversible acetylation in metabolic control and how changes in levels of metabolites or cofactors, including nicotinamide adenine dinucleotide, nicotinamide, coenzyme A, acetyl coenzyme A, zinc and butyrate and/or β-hydroxybutyrate, directly alter KAT or KDAC activity to link energy status to adaptive cellular and organismal homeostasis.
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Affiliation(s)
- Keir J Menzies
- Interdisciplinary School of Health Sciences, University of Ottawa, 501 Smyth Road, Ottawa, ON K1H 8L6, Canada
| | - Hongbo Zhang
- Laboratory of Integrative and Systems Physiology, École Polytechnique Fédérale de Lausanne, Station 15, 1015 Lausanne, Switzerland
| | - Elena Katsyuba
- Laboratory of Integrative and Systems Physiology, École Polytechnique Fédérale de Lausanne, Station 15, 1015 Lausanne, Switzerland
| | - Johan Auwerx
- Laboratory of Integrative and Systems Physiology, École Polytechnique Fédérale de Lausanne, Station 15, 1015 Lausanne, Switzerland
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Fatt M, Hsu K, He L, Wondisford F, Miller FD, Kaplan DR, Wang J. Metformin Acts on Two Different Molecular Pathways to Enhance Adult Neural Precursor Proliferation/Self-Renewal and Differentiation. Stem Cell Reports 2015; 5:988-995. [PMID: 26677765 PMCID: PMC4682208 DOI: 10.1016/j.stemcr.2015.10.014] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2015] [Revised: 10/23/2015] [Accepted: 10/26/2015] [Indexed: 12/15/2022] Open
Abstract
The recruitment of endogenous adult neural stem cells for brain repair is a promising regenerative therapeutic strategy. This strategy involves stimulation of multiple stages of adult neural stem cell development, including proliferation, self-renewal, and differentiation. Currently, there is a lack of a single therapeutic approach that can act on these multiple stages of adult neural stem cell development to enhance neural regeneration. Here we show that metformin, an FDA-approved diabetes drug, promotes proliferation, self-renewal, and differentiation of adult neural precursors (NPCs). Specifically, we show that metformin enhances adult NPC proliferation and self-renewal dependent upon the p53 family member and transcription factor TAp73, while it promotes neuronal differentiation of these cells by activating the AMPK-aPKC-CBP pathway. Thus, metformin represents an optimal candidate neuro-regenerative agent that is capable of not only expanding the adult NPC population but also subsequently driving them toward neuronal differentiation by activating two distinct molecular pathways.
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Affiliation(s)
- Michael Fatt
- Program in Neurosciences and Mental Health, Hospital for Sick Children, Toronto, ON M5G 1X8, Canada; Institute of Medical Science, University of Toronto, Toronto, ON M5G 1X5, Canada
| | - Karolynn Hsu
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
| | - Ling He
- Department of Pediatrics and Medicine, Johns Hopkins Medical School, Baltimore, MD 21287, USA
| | - Fredric Wondisford
- Department of Medicine, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ 08901, USA
| | - Freda D Miller
- Program in Neurosciences and Mental Health, Hospital for Sick Children, Toronto, ON M5G 1X8, Canada; Institute of Medical Science, University of Toronto, Toronto, ON M5G 1X5, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1X5, Canada; Department of Physiology, University of Toronto, Toronto, ON M5G 1X5, Canada
| | - David R Kaplan
- Program in Neurosciences and Mental Health, Hospital for Sick Children, Toronto, ON M5G 1X8, Canada; Institute of Medical Science, University of Toronto, Toronto, ON M5G 1X5, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1X5, Canada
| | - Jing Wang
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada; Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada; Brain and Mind Research Institute, University of Ottawa, Ottawa, ON K1H 8M5, Canada.
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37
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Chen W, Goff MR, Kuang H, Chen G. Higher protein kinase C ζ in fatty rat liver and its effect on insulin actions in primary hepatocytes. PLoS One 2015; 10:e0121890. [PMID: 25822413 PMCID: PMC4379029 DOI: 10.1371/journal.pone.0121890] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Accepted: 02/04/2015] [Indexed: 02/07/2023] Open
Abstract
We previously showed the impairment of insulin-regulated gene expression in the primary hepatocytes from Zucker fatty (ZF) rats, and its association with alterations of hepatic glucose and lipid metabolism. However, the molecular mechanism is unknown. A preliminary experiment shows that the expression level of protein kinase C ζ (PKCζ), a member of atypical PKC family, is higher in the liver and hepatocytes of ZF rats than that of Zucker lean (ZL) rats. Herein, we intend to investigate the roles of atypical protein kinase C in the regulation of hepatic gene expression. The insulin-regulated hepatic gene expression was evaluated in ZL primary hepatocytes treated with atypical PKC recombinant adenoviruses. Recombinant adenovirus-mediated overexpression of PKCζ, or the other atypical PKC member PKCι/λ, alters the basal and impairs the insulin-regulated expressions of glucokinase, sterol regulatory element-binding protein 1c, the cytosolic form of phosphoenolpyruvate carboxykinase, the catalytic subunit of glucose 6-phosphatase, and insulin like growth factor-binding protein 1 in ZL primary hepatocytes. PKCζ or PKCι/λ overexpression also reduces the protein level of insulin receptor substrate 1, and the insulin-induced phosphorylation of AKT at Ser473 and Thr308. Additionally, PKCι/λ overexpression impairs the insulin-induced Prckz expression, indicating the crosstalk between PKCζ and PKCι/λ. We conclude that the PKCζ expression is elevated in hepatocytes of insulin resistant ZF rats. Overexpressions of aPKCs in primary hepatocytes impair insulin signal transduction, and in turn, the down-stream insulin-regulated gene expression. These data suggest that elevation of aPKC expression may contribute to the hepatic insulin resistance at gene expression level.
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Affiliation(s)
- Wei Chen
- Department of Nutrition, University of Tennessee at Knoxville, Knoxville, Tennessee, United States of America
| | - Matthew Ray Goff
- Department of Nutrition, University of Tennessee at Knoxville, Knoxville, Tennessee, United States of America
| | - Heqian Kuang
- Department of Nutrition, University of Tennessee at Knoxville, Knoxville, Tennessee, United States of America
| | - Guoxun Chen
- Department of Nutrition, University of Tennessee at Knoxville, Knoxville, Tennessee, United States of America
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38
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Affiliation(s)
| | - Philip A. Cole
- Department
of Pharmacology
and Molecular Sciences, The Johns Hopkins
University School of Medicine, 725 North Wolfe Street, Hunterian 316, Baltimore, Maryland 21205, United States
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Milite C, Feoli A, Sasaki K, La Pietra V, Balzano AL, Marinelli L, Mai A, Novellino E, Castellano S, Tosco A, Sbardella G. A novel cell-permeable, selective, and noncompetitive inhibitor of KAT3 histone acetyltransferases from a combined molecular pruning/classical isosterism approach. J Med Chem 2015; 58:2779-98. [PMID: 25730130 DOI: 10.1021/jm5019687] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Selective inhibitors of the two paralogue KAT3 acetyltransferases (CBP and p300) may serve not only as precious chemical tools to investigate the role of these enzymes in physiopathological mechanisms but also as lead structures for the development of further antitumor agents. After the application of a molecular pruning approach to the hardly optimizable and not very cell-permeable garcinol core structure, we prepared many analogues that were screened for their inhibitory effects using biochemical and biophysical (SPR) assays. Further optimization led to the discovery of the benzylidenebarbituric acid derivative 7h (EML425) as a potent and selective reversible inhibitor of CBP/p300, noncompetitive versus both acetyl-CoA and a histone H3 peptide, and endowed with good cell permeability. Furthermore, in human leukemia U937 cells, it induced a marked and time-dependent reduction in the acetylation of lysine H4K5 and H3K9, a marked arrest in the G0/G1 phase and a significant increase in the hypodiploid nuclei percentage.
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Affiliation(s)
- Ciro Milite
- †Epigenetic Med Chem Lab, Dipartimento di Farmacia, Università degli Studi di Salerno, Via Giovanni Paolo II 132, I-84084 Fisciano, Salerno, Italy
| | - Alessandra Feoli
- †Epigenetic Med Chem Lab, Dipartimento di Farmacia, Università degli Studi di Salerno, Via Giovanni Paolo II 132, I-84084 Fisciano, Salerno, Italy
| | - Kazuki Sasaki
- ‡Chemical Genetics Laboratory, RIKEN Advanced Science Institute, Wako, Saitama 351-0198, Japan.,§Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency (JST), 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
| | - Valeria La Pietra
- ∥Dipartimento di Farmacia, Università di Napoli "Federico II" Via D. Montesano 49, I-80131 Naples, Italy
| | - Amodio Luca Balzano
- †Epigenetic Med Chem Lab, Dipartimento di Farmacia, Università degli Studi di Salerno, Via Giovanni Paolo II 132, I-84084 Fisciano, Salerno, Italy
| | - Luciana Marinelli
- ∥Dipartimento di Farmacia, Università di Napoli "Federico II" Via D. Montesano 49, I-80131 Naples, Italy
| | - Antonello Mai
- ⊥Dipartimento di Chimica e Tecnologie del Farmaco, "Sapienza" Università di Roma, P.le A. Moro 5, I-00185 Rome, Italy
| | - Ettore Novellino
- ∥Dipartimento di Farmacia, Università di Napoli "Federico II" Via D. Montesano 49, I-80131 Naples, Italy
| | - Sabrina Castellano
- †Epigenetic Med Chem Lab, Dipartimento di Farmacia, Università degli Studi di Salerno, Via Giovanni Paolo II 132, I-84084 Fisciano, Salerno, Italy.,#Dipartimento di Medicina e Chirurgia, Università degli Studi di Salerno, Via Salvador Allende, I-84081 Baronissi, Salerno, Italy
| | - Alessandra Tosco
- †Epigenetic Med Chem Lab, Dipartimento di Farmacia, Università degli Studi di Salerno, Via Giovanni Paolo II 132, I-84084 Fisciano, Salerno, Italy
| | - Gianluca Sbardella
- †Epigenetic Med Chem Lab, Dipartimento di Farmacia, Università degli Studi di Salerno, Via Giovanni Paolo II 132, I-84084 Fisciano, Salerno, Italy
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40
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Insights into Transcriptional Regulation of Hepatic Glucose Production. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2015; 318:203-53. [DOI: 10.1016/bs.ircmb.2015.05.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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41
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Sun C, Wang M, Liu X, Luo L, Li K, Zhang S, Wang Y, Yang Y, Ding F, Gu X. PCAF improves glucose homeostasis by suppressing the gluconeogenic activity of PGC-1α. Cell Rep 2014; 9:2250-62. [PMID: 25497092 DOI: 10.1016/j.celrep.2014.11.029] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2014] [Revised: 10/28/2014] [Accepted: 11/19/2014] [Indexed: 12/22/2022] Open
Abstract
PGC-1α plays a central role in hepatic gluconeogenesis and has been implicated in the onset of type 2 diabetes. Acetylation is an important posttranslational modification for regulating the transcriptional activity of PGC-1α. Here, we show that PCAF is a pivotal acetyltransferase for acetylating PGC-1α in both fasted and diabetic states. PCAF acetylates two lysine residues K328 and K450 in PGC-1α, which subsequently triggers its proteasomal degradation and suppresses its transcriptional activity. Adenoviral-mediated expression of PCAF in the obese mouse liver greatly represses gluconeogenic enzyme activation and glucose production and improves glucose homeostasis and insulin sensitivity. Moreover, liver-specific knockdown of PCAF stimulates PGC-1α activity, resulting in an increase in blood glucose and hepatic glucose output. Our results suggest that PCAF might be a potential pharmacological target for developing agents against metabolic disorders associated with hyperglycemia, such as obesity and diabetes.
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Affiliation(s)
- Cheng Sun
- Jiangsu Key Laboratory of Neuroregeneration, Nantong University, 19 Qixiu Road, Nantong, Jiangsu 226001, PRC; Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226001, PRC.
| | - Meihong Wang
- Jiangsu Key Laboratory of Neuroregeneration, Nantong University, 19 Qixiu Road, Nantong, Jiangsu 226001, PRC; Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226001, PRC
| | - Xiaoyu Liu
- Jiangsu Key Laboratory of Neuroregeneration, Nantong University, 19 Qixiu Road, Nantong, Jiangsu 226001, PRC; Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226001, PRC
| | - Lan Luo
- Department of Geratology, Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, PRC
| | - Kaixuan Li
- Department of Geratology, Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, PRC
| | - Shuqiang Zhang
- Jiangsu Key Laboratory of Neuroregeneration, Nantong University, 19 Qixiu Road, Nantong, Jiangsu 226001, PRC; Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226001, PRC
| | - Yongjun Wang
- Jiangsu Key Laboratory of Neuroregeneration, Nantong University, 19 Qixiu Road, Nantong, Jiangsu 226001, PRC; Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226001, PRC
| | - Yumin Yang
- Jiangsu Key Laboratory of Neuroregeneration, Nantong University, 19 Qixiu Road, Nantong, Jiangsu 226001, PRC; Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226001, PRC
| | - Fei Ding
- Jiangsu Key Laboratory of Neuroregeneration, Nantong University, 19 Qixiu Road, Nantong, Jiangsu 226001, PRC; Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226001, PRC
| | - Xiaosong Gu
- Jiangsu Key Laboratory of Neuroregeneration, Nantong University, 19 Qixiu Road, Nantong, Jiangsu 226001, PRC; Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226001, PRC.
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Abstract
The liver is an essential metabolic organ, and its metabolic function is controlled by insulin and other metabolic hormones. Glucose is converted into pyruvate through glycolysis in the cytoplasm, and pyruvate is subsequently oxidized in the mitochondria to generate ATP through the TCA cycle and oxidative phosphorylation. In the fed state, glycolytic products are used to synthesize fatty acids through de novo lipogenesis. Long-chain fatty acids are incorporated into triacylglycerol, phospholipids, and/or cholesterol esters in hepatocytes. These complex lipids are stored in lipid droplets and membrane structures, or secreted into the circulation as very low-density lipoprotein particles. In the fasted state, the liver secretes glucose through both glycogenolysis and gluconeogenesis. During pronged fasting, hepatic gluconeogenesis is the primary source for endogenous glucose production. Fasting also promotes lipolysis in adipose tissue, resulting in release of nonesterified fatty acids which are converted into ketone bodies in hepatic mitochondria though β-oxidation and ketogenesis. Ketone bodies provide a metabolic fuel for extrahepatic tissues. Liver energy metabolism is tightly regulated by neuronal and hormonal signals. The sympathetic system stimulates, whereas the parasympathetic system suppresses, hepatic gluconeogenesis. Insulin stimulates glycolysis and lipogenesis but suppresses gluconeogenesis, and glucagon counteracts insulin action. Numerous transcription factors and coactivators, including CREB, FOXO1, ChREBP, SREBP, PGC-1α, and CRTC2, control the expression of the enzymes which catalyze key steps of metabolic pathways, thus controlling liver energy metabolism. Aberrant energy metabolism in the liver promotes insulin resistance, diabetes, and nonalcoholic fatty liver diseases.
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Affiliation(s)
- Liangyou Rui
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan
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43
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Wolfe A, Divall S, Wu S. The regulation of reproductive neuroendocrine function by insulin and insulin-like growth factor-1 (IGF-1). Front Neuroendocrinol 2014; 35:558-72. [PMID: 24929098 PMCID: PMC4175134 DOI: 10.1016/j.yfrne.2014.05.007] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2013] [Revised: 04/01/2014] [Accepted: 05/27/2014] [Indexed: 12/27/2022]
Abstract
The mammalian reproductive hormone axis regulates gonadal steroid hormone levels and gonadal function essential for reproduction. The neuroendocrine control of the axis integrates signals from a wide array of inputs. The regulatory pathways important for mediating these inputs have been the subject of numerous studies. One class of proteins that have been shown to mediate metabolic and growth signals to the CNS includes Insulin and IGF-1. These proteins are structurally related and can exert endocrine and growth factor like action via related receptor tyrosine kinases. The role that insulin and IGF-1 play in controlling the hypothalamus and pituitary and their role in regulating puberty and nutritional control of reproduction has been studied extensively. This review summarizes the in vitro and in vivo models that have been used to study these neuroendocrine structures and the influence of these growth factors on neuroendocrine control of reproduction.
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Affiliation(s)
- Andrew Wolfe
- Johns Hopkins University School of Medicine, Department of Pediatrics, Division of Endocrinology, Baltimore, MD 21287, United States.
| | - Sara Divall
- Johns Hopkins University School of Medicine, Department of Pediatrics, Division of Endocrinology, Baltimore, MD 21287, United States
| | - Sheng Wu
- Johns Hopkins University School of Medicine, Department of Pediatrics, Division of Endocrinology, Baltimore, MD 21287, United States
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Vu CU, Siddiqui JA, Wadensweiler P, Gayen JR, Avolio E, Bandyopadhyay GK, Biswas N, Chi NW, O'Connor DT, Mahata SK. Nicotinic acetylcholine receptors in glucose homeostasis: the acute hyperglycemic and chronic insulin-sensitive effects of nicotine suggest dual opposing roles of the receptors in male mice. Endocrinology 2014; 155:3793-805. [PMID: 25051446 DOI: 10.1210/en.2014-1320] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Cigarette smoking causes insulin resistance. However, nicotine induces anti-inflammation and improves glucose tolerance in insulin-resistant animal models. Here, we determined the effects of nicotine on glucose metabolism in insulin-sensitive C57BL/J6 mice. Acute nicotine administration (30 min) caused fasting hyperglycemia and lowered insulin sensitivity acutely, which depended on the activation of nicotinic-acetylcholine receptors (nAChRs) and correlated with increased catecholamine secretion, nitric oxide (NO) production, and glycogenolysis. Chlorisondamine, an inhibitor of nAChRs, reduced acute nicotine-induced hyperglycemia. qRT-PCR analysis revealed that the liver and muscle express predominantly β4 > α10 > α3 > α7 and β4 > α10 > β1 > α1 mRNA for nAChR subunits respectively, whereas the adrenal gland expresses β4 > α3 > α7 > α10 mRNA. Chronic nicotine treatment significantly suppressed expression of α3-nAChR (predominant peripheral α-subunit) in liver. Whereas acute nicotine treatment raised plasma norepinephrine (NE) and epinephrine (Epi) levels, chronic nicotine exposure raised only Epi. Acute nicotine treatment raised both basal and glucose-stimulated insulin secretion (GSIS). After chronic nicotine treatment, basal insulin level was elevated, but GSIS after acute saline or nicotine treatment was blunted. Chronic nicotine exposure caused an increased buildup of NO in plasma and liver, leading to decreased glycogen storage, along with a concomitant suppression of Pepck and G6Pase mRNA, thus preventing hyperglycemia. The insulin-sensitizing effect of chronic nicotine was independent of weight loss. Chronic nicotine treatment enhanced PI-3-kinase activities and increased Akt and glycogen synthase kinase (GSK)-3β phosphorylation in an nAChR-dependent manner coupled with decreased cAMP response element-binding protein (CREB) phosphorylation. The latter effects caused suppression of Pepck and G6Pase gene expression. Thus, nicotine causes both insulin resistance and insulin sensitivity depending on the duration of the treatment.
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Affiliation(s)
- Christine U Vu
- VA San Diego Healthcare System (C.U.V., P.W., J.R.G., G.K.B., N.-W.C., D.T.O'C., S.K.M.), San Diego, California 92161; and Department of Medicine (J.A.S., E.A., G.K.B., N.B., N.-W.C., S.K.M.), University of California, San Diego, California 92093
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Abstract
Metformin is a first-line, anti-diabetic agent prescribed to over 150 million people worldwide. The main effect of metformin is to suppress glucose production in the liver; however, there is no reliable biomarker to assess the effectiveness of metformin administration. Our previous studies have shown that phosphorylation of CBP at S436 is important for the regulation of hepatic glucose production by metformin. In current study, we found that CBP could be phosphorylated in white blood cells (WBCs), and CBP phosphorylation in the liver and in WBCs of mice had a similar pattern of change during a fasting time course experiment. These data suggests that CBP phosphorylation in WBCs may be used as a biomarker of metformin action in the liver.
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Affiliation(s)
- Ling He
- Division of MetabolismDivision of EndocrinologyDepartments of Pediatrics, Physiology and Medicine, Johns Hopkins University School of Medicine, 600 North Wolfe Street, Baltimore, Maryland 21287, USAKennedy Krieger InstituteBaltimore, Maryland 21287, USA
| | - Shumei Meng
- Division of MetabolismDivision of EndocrinologyDepartments of Pediatrics, Physiology and Medicine, Johns Hopkins University School of Medicine, 600 North Wolfe Street, Baltimore, Maryland 21287, USAKennedy Krieger InstituteBaltimore, Maryland 21287, USA
| | - Emily L Germain-Lee
- Division of MetabolismDivision of EndocrinologyDepartments of Pediatrics, Physiology and Medicine, Johns Hopkins University School of Medicine, 600 North Wolfe Street, Baltimore, Maryland 21287, USAKennedy Krieger InstituteBaltimore, Maryland 21287, USADivision of MetabolismDivision of EndocrinologyDepartments of Pediatrics, Physiology and Medicine, Johns Hopkins University School of Medicine, 600 North Wolfe Street, Baltimore, Maryland 21287, USAKennedy Krieger InstituteBaltimore, Maryland 21287, USA
| | - Sally Radovick
- Division of MetabolismDivision of EndocrinologyDepartments of Pediatrics, Physiology and Medicine, Johns Hopkins University School of Medicine, 600 North Wolfe Street, Baltimore, Maryland 21287, USAKennedy Krieger InstituteBaltimore, Maryland 21287, USA
| | - Fredric E Wondisford
- Division of MetabolismDivision of EndocrinologyDepartments of Pediatrics, Physiology and Medicine, Johns Hopkins University School of Medicine, 600 North Wolfe Street, Baltimore, Maryland 21287, USAKennedy Krieger InstituteBaltimore, Maryland 21287, USA
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Lee D, Le Lay J, Kaestner KH. The transcription factor CREB has no non-redundant functions in hepatic glucose metabolism in mice. Diabetologia 2014; 57:1242-8. [PMID: 24595858 DOI: 10.1007/s00125-014-3203-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Accepted: 01/31/2014] [Indexed: 10/25/2022]
Abstract
AIMS/HYPOTHESIS Excessive hepatic glucose production is a hallmark of insulin resistance in type 2 diabetes. The cAMP responsive transcription factor cAMP responsive element binding protein (CREB), thought to be a key activator of the hepatic gluconeogenic gene regulation programme, has been suggested as a therapeutic target to reduce glucose output by the liver. Here, we test directly the requirement for hepatocytic CREB for the maintenance of glucose homeostasis. METHODS We derived mice with a Creb (also known as Creb1) loxP allele for conditional, cell-type specific gene ablation. Hepatocyte-specific deletion of Creb was induced by injecting Creb (loxP/loxP) mice with Cre recombinase expression adeno-associated virus. RESULTS Strikingly, we found no difference in fed and fasted glucose levels, or in glucose, insulin and glucagon tolerance in mice fed a normal chow or a high-fat diet. In addition, mRNA levels of liver-specific genes, including several CREB target genes involved in gluconeogenesis, were not affected by CREB deficiency in the liver. CONCLUSION/INTERPRETATION Our data show that CREB has no non-redundant functions in hepatic glucose metabolism, and is therefore not likely to be a useful target for the development of glucose-lowering drugs.
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Affiliation(s)
- Dolim Lee
- Department of Genetics and Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, 12-126 Translational Research Center, 3400 Civic Center Boulevard, Philadelphia, PA, 19104-6145, USA
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Ezrokhi M, Luo S, Trubitsyna Y, Cincotta AH. Neuroendocrine and metabolic components of dopamine agonist amelioration of metabolic syndrome in SHR rats. Diabetol Metab Syndr 2014; 6:104. [PMID: 25937836 PMCID: PMC4416398 DOI: 10.1186/1758-5996-6-104] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Accepted: 09/16/2014] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND The hypertensive, pro-inflammatory, obese state is strongly coupled to peripheral and hepatic insulin resistance (in composite termed metabolic syndrome [MS]). Hepatic pro-inflammatory pathways have been demonstrated to initiate or exacerbate hepatic insulin resistance and contribute to fatty liver, a correlate of MS. Previous studies in seasonally obese animals have implicated an important role for circadian phase-dependent increases in hypothalamic dopaminergic tone in the maintenance of the lean, insulin sensitive condition. However, mechanisms driving this dopaminergic effect have not been fully delineated and the impact of such dopaminergic function upon the above mentioned parameters of MS, particularly upon key intra-hepatic regulators of liver inflammation and lipid and glucose metabolism have never been investigated. OBJECTIVE This study therefore investigated the effects of timed daily administration of bromocriptine, a potent dopamine D2 receptor agonist, on a) ventromedial hypothalamic catecholamine activity, b) MS and c) hepatic protein levels of key regulators of liver inflammation and glucose and lipid metabolism in a non-seasonal model of MS - the hypertensive, obese SHR rat. METHODS Sixteen week old SHR rats maintained on 14 hour daily photoperiods were treated daily for 16 days with bromocriptine (10 mg/kg, i.p.) or vehicle at 1 hour before light offset and, subsequent to blood pressure recordings on day 14, were then utilized for in vivo microdialysis of ventromedial hypothalamic catecholamine activity or sacrificed for the analyses of MS factors and regulators of hepatic metabolism. Normal Wistar rats served as wild-type controls for hypothalamic activity, body fat levels, and insulin sensitivity. RESULTS Bromocriptine treatment significantly reduced ventromedial hypothalamic norepinephrine and serotonin levels to the normal range and systolic and diastolic blood pressures, retroperitoneal body fat level, plasma insulin and glucose levels and HOMA-IR relative to vehicle treated SHR controls. Such treatment also reduced plasma levels of C-reactive protein, leptin, and norepinephrine and increased that of plasma adiponectin significantly relative to SHR controls. Finally, bromocriptine treatment significantly reduced hepatic levels of several pro-inflammatory pathway proteins and of the master transcriptional activators of lipogenesis, gluconeogenesis, and free fatty acid oxidation versus control SHR rats. CONCLUSION These findings indicate that in SHR rats, timed daily dopamine agonist treatment improves hypothalamic and neuroendocrine pathologies associated with MS and such neuroendocrine events are coupled to a transformation of liver metabolism potentiating a reduction of elevated lipogenic and gluconeogenic capacity. This liver effect may be driven in part by concurrent reductions in hyperinsulinemia and sympathetic tone as well as by reductions in intra-hepatic inflammation.
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Wang F, Marshall CB, Ikura M. Transcriptional/epigenetic regulator CBP/p300 in tumorigenesis: structural and functional versatility in target recognition. Cell Mol Life Sci 2013; 70:3989-4008. [PMID: 23307074 PMCID: PMC11113169 DOI: 10.1007/s00018-012-1254-4] [Citation(s) in RCA: 208] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Revised: 11/08/2012] [Accepted: 12/20/2012] [Indexed: 01/19/2023]
Abstract
In eukaryotic cells, gene transcription is regulated by sequence-specific DNA-binding transcription factors that recognize promoter and enhancer elements near the transcriptional start site. Some coactivators promote transcription by connecting transcription factors to the basal transcriptional machinery. The highly conserved coactivators CREB-binding protein (CBP) and its paralog, E1A-binding protein (p300), each have four separate transactivation domains (TADs) that interact with the TADs of a number of DNA-binding transcription activators as well as general transcription factors (GTFs), thus mediating recruitment of basal transcription machinery to the promoter. Most promoters comprise multiple activator-binding sites, and many activators contain tandem TADs, thus multivalent interactions may stabilize CBP/p300 at the promoter, and intrinsically disordered regions in CBP/p300 and many activators may confer adaptability to these multivalent complexes. CBP/p300 contains a catalytic histone acetyltransferase (HAT) domain, which remodels chromatin to 'relax' its superstructure and enables transcription of proximal genes. The HAT activity of CBP/p300 also acetylates some transcription factors (e.g., p53), hence modulating the function of key transcriptional regulators. Through these numerous interactions, CBP/p300 has been implicated in complex physiological and pathological processes, and, in response to different signals, can drive cells towards proliferation or apoptosis. Dysregulation of the transcriptional and epigenetic functions of CBP/p300 is associated with leukemia and other types of cancer, thus it has been recognized as a potential anti-cancer drug target. In this review, we focus on recent exciting findings in the structural mechanisms of CBP/p300 involving multivalent and dynamic interactions with binding partners, which may pave new avenues for anti-cancer drug development.
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Affiliation(s)
- Feng Wang
- Department of Medical Biophysics, University of Toronto, Toronto, ON M5G 2M9 Canada
- Campbell Family Cancer Research Institute, Ontario Cancer Institute, Princess Margaret Cancer Center, University Health Network, Toronto, ON M5G 1L7 Canada
- Present Address: Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232 USA
| | - Christopher B. Marshall
- Department of Medical Biophysics, University of Toronto, Toronto, ON M5G 2M9 Canada
- Campbell Family Cancer Research Institute, Ontario Cancer Institute, Princess Margaret Cancer Center, University Health Network, Toronto, ON M5G 1L7 Canada
| | - Mitsuhiko Ikura
- Department of Medical Biophysics, University of Toronto, Toronto, ON M5G 2M9 Canada
- Campbell Family Cancer Research Institute, Ontario Cancer Institute, Princess Margaret Cancer Center, University Health Network, Toronto, ON M5G 1L7 Canada
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Mobbs CV, Moreno CL, Poplawski M. Metabolic mystery: aging, obesity, diabetes, and the ventromedial hypothalamus. Trends Endocrinol Metab 2013; 24:488-94. [PMID: 23791973 PMCID: PMC4325996 DOI: 10.1016/j.tem.2013.05.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/24/2012] [Revised: 05/14/2013] [Accepted: 05/22/2013] [Indexed: 01/04/2023]
Abstract
We propose that energy balance, glucose homeostasis, and aging are all regulated largely by the same nutrient-sensing neurons in the ventromedial hypothalamus (VMH). Although the central role of these neurons in regulating energy balance is clear, their role in regulating glucose homeostasis has only recently become more clear. This latter function may be most relevant to aging and lifespan by controlling the rate of glucose metabolism. Specifically, glucose-sensing neurons in VMH promote peripheral glucose metabolism, and dietary restriction, by reducing glucose metabolism in these neurons, reduces glucose metabolism of the rest of the body, thereby increasing lifespan. Here we discuss recent studies demonstrating the key role of hypothalamic neurons in driving aging and age-related diseases.
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Affiliation(s)
- Charles V Mobbs
- Departments of Neuroscience, Endocrinology, and Geriatrics, and the Friedman Brain Institute, Mount Sinai School of Medicine, New York, NY 10029, USA.
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Hennig AK, Peng GH, Chen S. Transcription coactivators p300 and CBP are necessary for photoreceptor-specific chromatin organization and gene expression. PLoS One 2013; 8:e69721. [PMID: 23922782 PMCID: PMC3724885 DOI: 10.1371/journal.pone.0069721] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Accepted: 06/12/2013] [Indexed: 12/12/2022] Open
Abstract
Rod and cone photoreceptor neurons in the mammalian retina possess specialized cellular architecture and functional features for converting light to a neuronal signal. Establishing and maintaining these characteristics requires appropriate expression of a specific set of genes, which is tightly regulated by a network of photoreceptor transcription factors centered on the cone-rod homeobox protein CRX. CRX recruits transcription coactivators p300 and CBP to acetylate promoter-bound histones and activate transcription of target genes. To further elucidate the role of these two coactivators, we conditionally knocked out Ep300 and/or CrebBP in differentiating rods or cones, using opsin-driven Cre recombinase. Knockout of either factor alone exerted minimal effects, but loss of both factors severely disrupted target cell morphology and function: the unique nuclear chromatin organization seen in mouse rods was reversed, accompanied by redistribution of nuclear territories associated with repressive and active histone marks. Transcription of many genes including CRX targets was severely impaired, correlating with reduced histone H3/H4 acetylation (the products of p300/CBP) on target gene promoters. Interestingly, the presence of a single wild-type allele of either coactivator prevented many of these defects, with Ep300 more effective than Cbp. These results suggest that p300 and CBP play essential roles in maintaining photoreceptor-specific structure, function and gene expression.
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Affiliation(s)
- Anne K. Hennig
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Guang-Hua Peng
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Shiming Chen
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri, United States of America
- * E-mail:
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