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Wu HF, Saito-Diaz K, Huang CW, McAlpine JL, Seo DE, Magruder DS, Ishan M, Bergeron HC, Delaney WH, Santori FR, Krishnaswamy S, Hart GW, Chen YW, Hogan RJ, Liu HX, Ivanova NB, Zeltner N. Parasympathetic neurons derived from human pluripotent stem cells model human diseases and development. Cell Stem Cell 2024; 31:734-753.e8. [PMID: 38608707 PMCID: PMC11069445 DOI: 10.1016/j.stem.2024.03.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Revised: 01/16/2024] [Accepted: 03/13/2024] [Indexed: 04/14/2024]
Abstract
Autonomic parasympathetic neurons (parasymNs) control unconscious body responses, including "rest-and-digest." ParasymN innervation is important for organ development, and parasymN dysfunction is a hallmark of autonomic neuropathy. However, parasymN function and dysfunction in humans are vastly understudied due to the lack of a model system. Human pluripotent stem cell (hPSC)-derived neurons can fill this void as a versatile platform. Here, we developed a differentiation paradigm detailing the derivation of functional human parasymNs from Schwann cell progenitors. We employ these neurons (1) to assess human autonomic nervous system (ANS) development, (2) to model neuropathy in the genetic disorder familial dysautonomia (FD), (3) to show parasymN dysfunction during SARS-CoV-2 infection, (4) to model the autoimmune disease Sjögren's syndrome (SS), and (5) to show that parasymNs innervate white adipocytes (WATs) during development and promote WAT maturation. Our model system could become instrumental for future disease modeling and drug discovery studies, as well as for human developmental studies.
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Affiliation(s)
- Hsueh-Fu Wu
- Center for Molecular Medicine, University of Georgia, Athens, GA 30602, USA; Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
| | - Kenyi Saito-Diaz
- Center for Molecular Medicine, University of Georgia, Athens, GA 30602, USA
| | - Chia-Wei Huang
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA; Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA
| | - Jessica L McAlpine
- Center for Molecular Medicine, University of Georgia, Athens, GA 30602, USA; Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
| | - Dong Eun Seo
- Center for Molecular Medicine, University of Georgia, Athens, GA 30602, USA; Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
| | - D Sumner Magruder
- Department of Genetics, Department of Computer Science, Wu Tsai Institute, Program for Computational Biology and Bioinformatics, Yale University, New Haven, CT 06520, USA
| | - Mohamed Ishan
- Regenerative Bioscience Center, Department of Animal and Dairy Science College of Agricultural and Environmental Sciences, University of Georgia, Athens, GA 30602, USA
| | - Harrison C Bergeron
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA
| | - William H Delaney
- Center for Molecular Medicine, University of Georgia, Athens, GA 30602, USA
| | - Fabio R Santori
- Center for Molecular Medicine, University of Georgia, Athens, GA 30602, USA
| | - Smita Krishnaswamy
- Department of Genetics, Department of Computer Science, Wu Tsai Institute, Program for Computational Biology and Bioinformatics, Yale University, New Haven, CT 06520, USA
| | - Gerald W Hart
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA; Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA
| | - Ya-Wen Chen
- Department of Otolaryngology, Department of Cell, Developmental, and Regenerative Biology, Institute for Airway Sciences, Institute for Regenerative Medicine, Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Robert J Hogan
- Department of Biomedical Sciences, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA; Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA
| | - Hong-Xiang Liu
- Regenerative Bioscience Center, Department of Animal and Dairy Science College of Agricultural and Environmental Sciences, University of Georgia, Athens, GA 30602, USA
| | - Natalia B Ivanova
- Center for Molecular Medicine, University of Georgia, Athens, GA 30602, USA; Department of Genetics, University of Georgia, Athens, GA 30602, USA
| | - Nadja Zeltner
- Center for Molecular Medicine, University of Georgia, Athens, GA 30602, USA; Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA; Department of Cellular Biology, University of Georgia, Athens, GA 30602, USA.
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Huang CW, Rust NC, Wu HF, Yin A, Zeltner N, Yin H, Hart GW. Low glucose induced Alzheimer's disease-like biochemical changes in human induced pluripotent stem cell-derived neurons is due to dysregulated O-GlcNAcylation. Alzheimers Dement 2023; 19:4872-4885. [PMID: 37037474 PMCID: PMC10562522 DOI: 10.1002/alz.13058] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2022] [Revised: 02/22/2023] [Accepted: 03/06/2023] [Indexed: 04/12/2023]
Abstract
INTRODUCTION Sporadic Alzheimer's disease (sAD) is the leading type of dementia. Brain glucose hypometabolism, along with decreased O-GlcNAcylation levels, occurs before the onset of symptoms and correlates with pathogenesis. Heretofore, the mechanisms involved and the roles of O-GlcNAcylation in sAD pathology largely remain unknown due to a lack of human models of sAD. METHODS Human cortical neurons were generated from pluripotent stem cells (PSCs) and treated with glucose reduction media. RESULTS We found a narrow window of glucose concentration that induces sAD-like phenotypes in PSC-derived neurons. With our model, we reveal that dysregulated O-GlcNAc, in part through mitochondrial dysfunction, causes the onset of sAD-like changes. We demonstrate the therapeutic potential of inhibiting O-GlcNAcase in alleviating AD-like biochemical changes. DISCUSSION Our results suggest that dysregulated O-GlcNAc might be a direct molecular link between hypometabolism and sAD-like alternations. Moreover, this model can be exploited to explore molecular processes and for drug development. HIGHLIGHTS Lowering glucose to a critical level causes AD-like changes in cortical neurons. Defective neuronal structure and function were also recapitulated in current model. Dysregulated O-GlcNAcylation links impaired glucose metabolism to AD-like changes. Mitochondrial abnormalities correlate with O-GlcNAcylation and precede AD-like phenotype. Our model provides a platform to study sAD as a metabolic disease in human neurons.
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Affiliation(s)
- Chia-Wei Huang
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, 30602, USA
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Nicholas C. Rust
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, 30602, USA
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Hsueh-Fu Wu
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA
- Center for Molecular Medicine, University of Georgia, Athens, GA, 30602, USA
| | - Amelia Yin
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA
- Center for Molecular Medicine, University of Georgia, Athens, GA, 30602, USA
| | - Nadja Zeltner
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA
- Center for Molecular Medicine, University of Georgia, Athens, GA, 30602, USA
| | - Hang Yin
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA
- Center for Molecular Medicine, University of Georgia, Athens, GA, 30602, USA
| | - Gerald W. Hart
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, 30602, USA
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA
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Tian JL, Huang CW, Eslami F, Mannino MP, Mai RL, Hart GW. Regulation of Primary Cilium Length by O-GlcNAc during Neuronal Development in a Human Neuron Model. Cells 2023; 12:1520. [PMID: 37296641 PMCID: PMC10252524 DOI: 10.3390/cells12111520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 05/25/2023] [Accepted: 05/29/2023] [Indexed: 06/12/2023] Open
Abstract
The primary cilium plays critical roles in the homeostasis and development of neurons. Recent studies demonstrate that cilium length is regulated by the metabolic state of cells, as dictated by processes such as glucose flux and O-GlcNAcylation (OGN). The study of cilium length regulation during neuron development, however, has been an area left largely unexplored. This project aims to elucidate the roles of O-GlcNAc in neuronal development through its regulation of the primary cilium. Here, we present findings suggesting that OGN levels negatively regulate cilium length on differentiated cortical neurons derived from human-induced pluripotent stem cells. In neurons, cilium length increased significantly during maturation (after day 35), while OGN levels began to drop. Long-term perturbation of OGN via drugs, which inhibit or promote its cycling, during neuron development also have varying effects. Diminishing OGN levels increases cilium length until day 25, when neural stem cells expand and undergo early neurogenesis, before causing cell cycle exit defects and multinucleation. Elevating OGN levels induces greater primary cilia assembly but ultimately results in the development of premature neurons, which have higher insulin sensitivity. These results indicate that OGN levels and primary cilium length are jointly critical in proper neuron development and function. Understanding the interplays between these two nutrient sensors, O-GlcNAc and the primary cilium, during neuron development is important in paving connections between dysfunctional nutrient-sensing and early neurological disorders.
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Affiliation(s)
- Jie L. Tian
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA; (C.-W.H.); (F.E.); (M.P.M.); (R.L.M.)
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
| | - Chia-Wei Huang
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA; (C.-W.H.); (F.E.); (M.P.M.); (R.L.M.)
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
| | - Farzad Eslami
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA; (C.-W.H.); (F.E.); (M.P.M.); (R.L.M.)
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
| | - Michael Philip Mannino
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA; (C.-W.H.); (F.E.); (M.P.M.); (R.L.M.)
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
| | - Rebecca Lee Mai
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA; (C.-W.H.); (F.E.); (M.P.M.); (R.L.M.)
- Department of Biology, University of Georgia, Athens, GA 30602, USA
| | - Gerald W. Hart
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA; (C.-W.H.); (F.E.); (M.P.M.); (R.L.M.)
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
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Wu HF, Huang CW, Art J, Liu HX, Hart GW, Zeltner N. O-GlcNAcylation is crucial for sympathetic neuron development, maintenance, functionality and contributes to peripheral neuropathy. Front Neurosci 2023; 17:1137847. [PMID: 37229433 PMCID: PMC10203903 DOI: 10.3389/fnins.2023.1137847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Accepted: 04/12/2023] [Indexed: 05/27/2023] Open
Abstract
O-GlcNAcylation is a post-translational modification (PTM) that regulates a wide range of cellular functions and has been associated with multiple metabolic diseases in various organs. The sympathetic nervous system (SNS) is the efferent portion of the autonomic nervous system that regulates metabolism of almost all organs in the body. How much the development and functionality of the SNS are influenced by O-GlcNAcylation, as well as how such regulation could contribute to sympathetic neuron (symN)-related neuropathy in diseased states, remains unknown. Here, we assessed the level of protein O-GlcNAcylation at various stages of symN development, using a human pluripotent stem cell (hPSC)-based symN differentiation paradigm. We found that pharmacological disruption of O-GlcNAcylation impaired both the growth and survival of hPSC-derived symNs. In the high glucose condition that mimics hyperglycemia, hPSC-derived symNs were hyperactive, and their regenerative capacity was impaired, which resembled typical neuronal defects in patients and animal models of diabetes mellitus. Using this model of sympathetic neuropathy, we discovered that O-GlcNAcylation increased in symNs under high glucose, which lead to hyperactivity. Pharmacological inhibition of O-GlcNAcylation rescued high glucose-induced symN hyperactivity and cell stress. This framework provides the first insight into the roles of O-GlcNAcylation in both healthy and diseased human symNs and may be used as a platform for therapeutic studies.
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Affiliation(s)
- Hsueh-Fu Wu
- Center for Molecular Medicine, University of Georgia, Athens, GA, United States
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, United States
| | - Chia-Wei Huang
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, United States
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, United States
| | - Jennifer Art
- Center for Molecular Medicine, University of Georgia, Athens, GA, United States
- Biomedical and Translational Sciences Institute, Neuroscience Program, University of Georgia, Athens, GA, United States
| | - Hong-Xiang Liu
- Regenerative Bioscience Center, Department of Animal and Dairy Science, College of Agricultural and Environmental Sciences, University of Georgia, Athens, GA, United States
| | - Gerald W. Hart
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, United States
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, United States
| | - Nadja Zeltner
- Center for Molecular Medicine, University of Georgia, Athens, GA, United States
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, United States
- Department of Cellular Biology, University of Georgia, Athens, GA, United States
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Zhu Y, Hart GW. Dual-specificity RNA aptamers enable manipulation of target-specific O-GlcNAcylation and unveil functions of O-GlcNAc on β-catenin. Cell 2023; 186:428-445.e27. [PMID: 36626902 PMCID: PMC9868088 DOI: 10.1016/j.cell.2022.12.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 11/02/2022] [Accepted: 12/08/2022] [Indexed: 01/11/2023]
Abstract
O-GlcNAc is a dynamic post-translational modification (PTM) that regulates protein functions. In studying the regulatory roles of O-GlcNAc, a major roadblock is the inability to change O-GlcNAcylation on a single protein at a time. Herein, we developed a dual RNA-aptamer-based approach that simultaneously targeted O-GlcNAc transferase (OGT) and β-catenin, the key transcription factor of the Wnt signaling pathway, to selectively increase O-GlcNAcylation of the latter without affecting other OGT substrates. Using the OGT/β-catenin dual-specificity aptamers, we found that O-GlcNAcylation of β-catenin stabilizes the protein by inhibiting its interaction with β-TrCP. O-GlcNAc also increases β-catenin's interaction with EZH2, recruits EZH2 to promoters, and dramatically alters the transcriptome. Further, by coupling riboswitches or an inducible expression system to aptamers, we enabled inducible regulation of protein-specific O-GlcNAcylation. Together, our findings demonstrate the efficacy and versatility of dual-specificity aptamers for regulating O-GlcNAcylation on individual proteins.
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Affiliation(s)
- Yi Zhu
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA.
| | - Gerald W Hart
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA.
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Wu HF, Yu W, Saito-Diaz K, Huang CW, Carey J, Lefcort F, Hart GW, Liu HX, Zeltner N. Norepinephrine transporter defects lead to sympathetic hyperactivity in Familial Dysautonomia models. Nat Commun 2022; 13:7032. [PMID: 36396637 PMCID: PMC9671909 DOI: 10.1038/s41467-022-34811-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 11/08/2022] [Indexed: 11/19/2022] Open
Abstract
Familial dysautonomia (FD), a rare neurodevelopmental and neurodegenerative disorder affects the sympathetic and sensory nervous system. Although almost all patients harbor a mutation in ELP1, it remains unresolved exactly how function of sympathetic neurons (symNs) is affected; knowledge critical for understanding debilitating disease hallmarks, including cardiovascular instability or dysautonomic crises, that result from dysregulated sympathetic activity. Here, we employ the human pluripotent stem cell (hPSC) system to understand symN disease mechanisms and test candidate drugs. FD symNs are intrinsically hyperactive in vitro, in cardiomyocyte co-cultures, and in animal models. We report reduced norepinephrine transporter expression, decreased intracellular norepinephrine (NE), decreased NE re-uptake, and excessive extracellular NE in FD symNs. SymN hyperactivity is not a direct ELP1 mutation result, but may connect to NET via RAB proteins. We found that candidate drugs lowered hyperactivity independent of ELP1 modulation. Our findings may have implications for other symN disorders and may allow future drug testing and discovery.
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Affiliation(s)
- Hsueh-Fu Wu
- Center for Molecular Medicine, University of Georgia, Athens, GA, USA
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, USA
| | - Wenxin Yu
- Regenerative Bioscience Center, Department of Animal and Dairy Science, College of Agricultural and Environmental Sciences, University of Georgia, Athens, GA, USA
| | - Kenyi Saito-Diaz
- Center for Molecular Medicine, University of Georgia, Athens, GA, USA
| | - Chia-Wei Huang
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, USA
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, USA
| | - Joseph Carey
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Frances Lefcort
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Gerald W Hart
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, USA
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, USA
| | - Hong-Xiang Liu
- Regenerative Bioscience Center, Department of Animal and Dairy Science, College of Agricultural and Environmental Sciences, University of Georgia, Athens, GA, USA
| | - Nadja Zeltner
- Center for Molecular Medicine, University of Georgia, Athens, GA, USA.
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, USA.
- Department of Cellular Biology, University of Georgia, Athens, GA, USA.
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Mannino MP, Hart GW. The Beginner’s Guide to O-GlcNAc: From Nutrient Sensitive Pathway Regulation to Its Impact on the Immune System. Front Immunol 2022; 13:828648. [PMID: 35173739 PMCID: PMC8841346 DOI: 10.3389/fimmu.2022.828648] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 01/05/2022] [Indexed: 12/27/2022] Open
Abstract
The addition of N-acetyl glucosamine (GlcNAc) on the hydroxy group of serine/threonine residues is known as O-GlcNAcylation (OGN). The dynamic cycling of this monosaccharide on and off substrates occurs via O-linked β-N-acetylglucosamine transferase (OGT) and O-linked β-N-acetylglucosaminase (OGA) respectively. These enzymes are found ubiquitously in eukaryotes and genetic knock outs of the ogt gene has been found to be lethal in embryonic mice. The substrate scope of these enzymes is vast, over 15,000 proteins across 43 species have been identified with O-GlcNAc. OGN has been known to play a key role in several cellular processes such as: transcription, translation, cell signaling, nutrient sensing, immune cell development and various steps of the cell cycle. However, its dysregulation is present in various diseases: cancer, neurodegenerative diseases, diabetes. O-GlcNAc is heavily involved in cross talk with other post-translational modifications (PTM), such as phosphorylation, acetylation, and ubiquitination, by regulating each other’s cycling enzymes or directly competing addition on the same substrate. This crosstalk between PTMs can affect gene expression, protein localization, and protein stability; therefore, regulating a multitude of cell signaling pathways. In this review the roles of OGN will be discussed. The effect O-GlcNAc exerts over protein-protein interactions, the various forms of crosstalk with other PTMs, and its role as a nutrient sensor will be highlighted. A summary of how these O-GlcNAc driven processes effect the immune system will also be included.
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Huang CW, Hart GW. Decreased O-GlcNAcylation and mitochondrial dysfunction are involving in low glucose induced Alzheimer's disease-like phenotype in induced pluripotent stem cell-derived neurons. Alzheimers Dement 2022. [PMID: 34971197 DOI: 10.1002/alz.058620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BACKGROUND Evidence supporting that glucose metabolic abnormalities occur prior to Alzheimer's disease (AD) symptoms. Reduced O-GlcNAc (OGN) levels likely arise from impaired glucose metabolism or availability and correlates with AD pathogenesis. So far, the mechanism of sAD and the role of OGN in AD pathology remained largely unknown due to a lack of human sAD model. METHOD We generated human cortical neurons from human-induced pluripotent stem cells and treated neurons with glucose reduction media. FluoroJADE staining and cell viability assays were used to study the effects of low glucose on the degenerative status and cell viability of neurons. Abnormal protein production, phosphorylation, and accumulation were detected by western blotting and immunofluorescence staining using antibody against p-tau and beta-amyloid. Neurite and synaptic structure were observed by immunofluorescence staining, while neuronal network activity was detected by multi-electrode array electrophysiological analyses. Mitochondrial abnormalities, including increased oxidative stress, reduced membrane potential, and mitochondrial dysfunction, were evaluated using CM-H2 DCFDA, JC-1 and Seahorse, respectively. RESULT We show that lowering glucose level to 2mM leads to dramatic increases of neuron degeneration on day 3 and 5 of treatment and decreased cell viability on day 7. Interestingly, long-term low glucose treatment induces AD features in neurons, including abnormal hyperphosphorylated tau accumulation and increasing beta-amyloid production. Besides, glucose deficiency also causes decreased neurite coverage, synapse density, and neuron network activity. Furthermore, we find that O-GlcNAc levels are significantly reduced soon after low glucose treatment and remain low until the end of experiment. Raising O-GlcNAc levels by thiamet-G, inhibitor of O-GlcNAcase, even in low glucose treated neurons, rescues low glucose-induced AD phenotypes. Moreover, our data shows that O-GlcNAc dysregulation causes mitochondrial abnormalities, which occur before any other degenerative phenotype appeared, and may be one of the underlying mechanisms of sAD onset and pathogenesis. CONCLUSION We established a human neuron model in which the pathological features are reproduced by glucose deficiency. This platform can serve as a tool for better understanding molecular processes involved in neurodegeneration in sAD. Our results also suggest that dysregulated O-GlcNAc levels and mitochondrial dysfunction by glucose deficiency are involved in the onset and progression of sAD.
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Fahie K, Narayanan B, Zahra F, Reeves R, Fernandes SM, Hart GW, Zachara NE. Detection and Analysis of Proteins Modified by O-Linked N-Acetylglucosamine. Curr Protoc 2021; 1:e129. [PMID: 34004049 DOI: 10.1002/cpz1.129] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
O-GlcNAc is a common post-translational modification of nuclear, mitochondrial, and cytoplasmic proteins that regulates normal physiology and the cell stress response. Dysregulation of O-GlcNAc cycling is implicated in the etiology of type II diabetes, heart failure, hypertension, and Alzheimer's disease, as well as cardioprotection. These protocols cover simple and comprehensive techniques for detecting proteins modified by O-GlcNAc and studying the enzymes that add or remove O-GlcNAc. © 2021 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Increasing the stoichiometry of O-GlcNAc on proteins before analysis Basic Protocol 2: Detection of proteins modified by O-GlcNAc using antibodies Basic Protocol 3: Detection of proteins modified by O-GlcNAc using the lectin sWGA Support Protocol 1: Control for O-linked glycosylation Basic Protocol 4: Detection and enrichment of proteins using WGA-agarose Support Protocol 2: Digestion of proteins with hexosaminidase Alternate Protocol: Detection of proteins modified by O-GlcNAc using galactosyltransferase Support Protocol 3: Autogalactosylation of galactosyltransferase Support Protocol 4: Assay of galactosyltransferase activity Basic Protocol 5: Characterization of labeled glycans by β-elimination and chromatography Basic Protocol 6: Detection of O-GlcNAc in 96-well plates Basic Protocol 7: Assay for OGT activity Support Protocol 5: Desalting of O-GlcNAc transferase Basic Protocol 8: Assay for O-GlcNAcase activity.
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Affiliation(s)
- Kamau Fahie
- The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | | | - Fiddia Zahra
- The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Russell Reeves
- The Johns Hopkins University School of Medicine, Baltimore, Maryland.,Current address: Department of Radiology, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania
| | - Steve M Fernandes
- The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Gerald W Hart
- Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia
| | - Natasha E Zachara
- The Johns Hopkins University School of Medicine, Baltimore, Maryland
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Hart GW, Wells L. Glycoproteomics: Making the Study of the Most Structurally Diverse and Most Abundant Post-Translational Modifications More Accessible to the Scientific Community. Mol Cell Proteomics 2021; 20:100086. [PMID: 34091217 PMCID: PMC8724864 DOI: 10.1016/j.mcpro.2021.100086] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Affiliation(s)
- Gerald W Hart
- Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia, USA
| | - Lance Wells
- Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia, USA
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Umapathi P, Mesubi OO, Banerjee PS, Abrol N, Wang Q, Luczak ED, Wu Y, Granger JM, Wei AC, Reyes Gaido OE, Florea L, Talbot CC, Hart GW, Zachara NE, Anderson ME. Excessive O-GlcNAcylation Causes Heart Failure and Sudden Death. Circulation 2021; 143:1687-1703. [PMID: 33593071 PMCID: PMC8085112 DOI: 10.1161/circulationaha.120.051911] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
BACKGROUND Heart failure is a leading cause of death worldwide and is associated with the rising prevalence of obesity, hypertension, and diabetes. O-GlcNAcylation (the attachment of O-linked β-N-acetylglucosamine [O-GlcNAc] moieties to cytoplasmic, nuclear, and mitochondrial proteins) is a posttranslational modification of intracellular proteins and serves as a metabolic rheostat for cellular stress. Total levels of O-GlcNAcylation are determined by nutrient and metabolic flux, in addition to the net activity of 2 enzymes: O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA). Failing myocardium is marked by increased O-GlcNAcylation, but whether excessive O-GlcNAcylation contributes to cardiomyopathy and heart failure is unknown. METHODS We developed 2 new transgenic mouse models with myocardial overexpression of OGT and OGA to control O-GlcNAcylation independent of pathologic stress. RESULTS We found that OGT transgenic hearts showed increased O-GlcNAcylation and developed severe dilated cardiomyopathy, ventricular arrhythmias, and premature death. In contrast, OGA transgenic hearts had lower O-GlcNAcylation but identical cardiac function to wild-type littermate controls. OGA transgenic hearts were resistant to pathologic stress induced by pressure overload with attenuated myocardial O-GlcNAcylation levels after stress and decreased pathologic hypertrophy compared with wild-type controls. Interbreeding OGT with OGA transgenic mice rescued cardiomyopathy and premature death, despite persistent elevation of myocardial OGT. Transcriptomic and functional studies revealed disrupted mitochondrial energetics with impairment of complex I activity in hearts from OGT transgenic mice. Complex I activity was rescued by OGA transgenic interbreeding, suggesting an important role for mitochondrial complex I in O-GlcNAc-mediated cardiac pathology. CONCLUSIONS Our data provide evidence that excessive O-GlcNAcylation causes cardiomyopathy, at least in part, attributable to defective energetics. Enhanced OGA activity is well tolerated and attenuation of O-GlcNAcylation is beneficial against pressure overload-induced pathologic remodeling and heart failure. These findings suggest that attenuation of excessive O-GlcNAcylation may represent a novel therapeutic approach for cardiomyopathy.
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Affiliation(s)
- Priya Umapathi
- Division of Cardiology, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Olurotimi O. Mesubi
- Division of Cardiology, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Partha S. Banerjee
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Neha Abrol
- Division of Cardiology, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Qinchuan Wang
- Division of Cardiology, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Elizabeth D. Luczak
- Division of Cardiology, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Yuejin Wu
- Division of Cardiology, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Jonathan M. Granger
- Division of Cardiology, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - An-Chi Wei
- Department of Electrical Engineering, Graduate Institute of Biomedical and Bioinformatics, National Taiwan University, Taiwan
| | - Oscar E. Reyes Gaido
- Division of Cardiology, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Liliana Florea
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Computational Biology Consulting Core, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - C. Conover Talbot
- Institute for Basic Biomedical Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Gerald W. Hart
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- The Complex Carbohydrate Research Center and Department of Biochemistry and Molecular Biology, Univ. of Georgia, Athens GA 30602, USA
| | - Natasha E. Zachara
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Mark E. Anderson
- Division of Cardiology, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Physiology, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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Mesubi OO, Rokita AG, Abrol N, Wu Y, Chen B, Wang Q, Granger JM, Tucker-Bartley A, Luczak ED, Murphy KR, Umapathi P, Banerjee PS, Boronina TN, Cole RN, Maier LS, Wehrens XH, Pomerantz JL, Song LS, Ahima RS, Hart GW, Zachara NE, Anderson ME. Oxidized CaMKII and O-GlcNAcylation cause increased atrial fibrillation in diabetic mice by distinct mechanisms. J Clin Invest 2021; 131:95747. [PMID: 33151911 PMCID: PMC7810480 DOI: 10.1172/jci95747] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Accepted: 11/03/2020] [Indexed: 12/21/2022] Open
Abstract
Diabetes mellitus (DM) and atrial fibrillation (AF) are major unsolved public health problems, and diabetes is an independent risk factor for AF. However, the mechanism(s) underlying this clinical association is unknown. ROS and protein O-GlcNAcylation (OGN) are increased in diabetic hearts, and calmodulin kinase II (CaMKII) is a proarrhythmic signal that may be activated by ROS (oxidized CaMKII, ox-CaMKII) and OGN (OGN-CaMKII). We induced type 1 (T1D) and type 2 DM (T2D) in a portfolio of genetic mouse models capable of dissecting the role of ROS and OGN at CaMKII and global OGN in diabetic AF. Here, we showed that T1D and T2D significantly increased AF, and this increase required CaMKII and OGN. T1D and T2D both required ox-CaMKII to increase AF; however, we did not detect OGN-CaMKII or a role for OGN-CaMKII in diabetic AF. Collectively, our data affirm CaMKII as a critical proarrhythmic signal in diabetic AF and suggest ROS primarily promotes AF by ox-CaMKII, while OGN promotes AF by a CaMKII-independent mechanism(s). These results provide insights into the mechanisms for increased AF in DM and suggest potential benefits for future CaMKII and OGN targeted therapies.
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Affiliation(s)
- Olurotimi O. Mesubi
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Adam G. Rokita
- Division of Cardiovascular Medicine and Cardiovascular Research Center, Carver College of Medicine, Iowa City, Iowa, USA
- Department of Internal Medicine II, University Hospital Regensburg, Regensburg, Germany
| | - Neha Abrol
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Yuejin Wu
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Biyi Chen
- Division of Cardiovascular Medicine and Cardiovascular Research Center, Carver College of Medicine, Iowa City, Iowa, USA
| | - Qinchuan Wang
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Jonathan M. Granger
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Anthony Tucker-Bartley
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Elizabeth D. Luczak
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Kevin R. Murphy
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Priya Umapathi
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Partha S. Banerjee
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Tatiana N. Boronina
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Robert N. Cole
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Lars S. Maier
- Department of Internal Medicine II, University Hospital Regensburg, Regensburg, Germany
| | - Xander H. Wehrens
- Department of Molecular Physiology and Biophysics, Department of Medicine (Cardiology), Department of Pediatrics, and Center for Space Medicine, Baylor College of Medicine, Houston, Texas, USA
| | - Joel L. Pomerantz
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Institute for Cell Engineering
| | - Long-Sheng Song
- Division of Cardiovascular Medicine and Cardiovascular Research Center, Carver College of Medicine, Iowa City, Iowa, USA
| | - Rexford S. Ahima
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine
| | - Gerald W. Hart
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Natasha E. Zachara
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Mark E. Anderson
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Department of Medicine, and
- Department of Physiology and Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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13
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Affiliation(s)
- Junfeng Ma
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Georgetown University, Washington D.C. 20057, United States
| | - Ci Wu
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Georgetown University, Washington D.C. 20057, United States
| | - Gerald W. Hart
- Department of Biochemistry and Molecular Biology, Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602, United States
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14
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Su Y, Ye X, Xu B, Li Y, Yang Q, Yu W, Song J, Guo C, Wang X, Hart GW, Sun H. CBS homogenization mutation strategy narrows the glycan binding profile of a GlcNAc-specific lectin AANL. Glycobiology 2020; 30:159-173. [PMID: 31616917 DOI: 10.1093/glycob/cwz089] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 10/08/2019] [Accepted: 10/08/2019] [Indexed: 11/14/2022] Open
Abstract
Glycosylation plays important roles in many cellular processes, such as signal transduction, cell cycle progression and transcriptional regulation. However, the identification and analysis of glycosylation are severely hampered by the low specificity or avidity of antiglycan antibodies and lectins. We have reported that a lectin AANL, which has high specificity for terminal GlcNAc glycans and contains six carbohydrate binding sites (CBSs), was used to enrich O-GlcNAcylated peptides. To further improve AANL binding specificity, we designed a CBS-homogenization strategy and restructured six mutant lectins, known as AANL1-AANL6. Affinity chromatography with GlcNAc and isothermal titration calorimetry analysis indicated that the two mutants (AANL3 and AANL6) all maintained GlcNAc binding activity. AANL6 and AANL3 showed higher specificity for terminal GlcNAc glycans than AANL, as shown by the hemagglutination assay, cell binding assays and glycan microarray analysis, and AANL6 exhibited the highest specificity. The binding activity of AANL6 for O-GlcNAcylated peptides was shown by surface plasmon resonance assays. By AANL6 affinity chromatography enrichment and mass spectrometry analysis, 79 high-confidence and 21 putative O-GlcNAcylated sites were identified on 85 peptides mapped onto 54 proteins. Most of these sites were new sites compared with reported data. These results indicate that the enrichment capacity of AANL6 is higher than that of wild-type AANL. In conclusion, the CBS-homogenization mutation strategy was successful, and AANL6 was identified as a powerful tool for O-GlcNAcylation enrichment. Our research suggests that the CBS-homogenization strategy is valuable for improving the specificity of lectins with multiple CBSs.
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Affiliation(s)
- Yanting Su
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Xiangdong Ye
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Bo Xu
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Yang Li
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Qing Yang
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Wenhui Yu
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Jiaqi Song
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Chanyuan Guo
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Xueqing Wang
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Gerald W Hart
- Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602, USA
| | - Hui Sun
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan 430072, China.,Hubei Province key Laboratory of Allergy and Immunology, Wuhan University, Wuhan 430072, China
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15
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Hart GW, Huang CW. Increased O-GlcNAcylation prevents degeneration of dopamine neurons. Brain 2020; 143:3515-3518. [PMID: 33439984 DOI: 10.1093/brain/awaa398] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 10/21/2020] [Indexed: 11/13/2022] Open
Abstract
This scientific commentary refers to ‘O-GlcNAcylation regulates dopamine neuron function, survival and degeneration in Parkinson disease’, by Lee et al. (doi:10.1093/brain/awaa320).
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Affiliation(s)
- Gerald W Hart
- Department of Biochemistry and Molecular Biology, Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA
| | - Chia-Wei Huang
- Department of Biochemistry and Molecular Biology, Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA
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16
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17
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Hardivillé S, Banerjee PS, Selen Alpergin ES, Smith DM, Han G, Ma J, Talbot CC, Hu P, Wolfgang MJ, Hart GW. TATA-Box Binding Protein O-GlcNAcylation at T114 Regulates Formation of the B-TFIID Complex and Is Critical for Metabolic Gene Regulation. Mol Cell 2019; 77:1143-1152.e7. [PMID: 31866147 DOI: 10.1016/j.molcel.2019.11.022] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 10/14/2019] [Accepted: 11/26/2019] [Indexed: 12/31/2022]
Abstract
In eukaryotes, gene expression is performed by three RNA polymerases that are targeted to promoters by molecular complexes. A unique common factor, the TATA-box binding protein (TBP), is thought to serve as a platform to assemble pre-initiation complexes competent for transcription. Here, we describe a novel molecular mechanism of nutrient regulation of gene transcription by dynamic O-GlcNAcylation of TBP. We show that O-GlcNAcylation at T114 of TBP blocks its interaction with BTAF1, hence the formation of the B-TFIID complex, and its dynamic cycling on and off of DNA. Transcriptomic and metabolomic analyses of TBPT114A CRISPR/Cas9-edited cells showed that loss of O-GlcNAcylation at T114 increases TBP binding to BTAF1 and directly impacts expression of 408 genes. Lack of O-GlcNAcylation at T114 is associated with a striking reprogramming of cellular metabolism induced by a profound modification of the transcriptome, leading to gross alterations in lipid storage.
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Affiliation(s)
- Stéphan Hardivillé
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
| | - Partha S Banerjee
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Ebru S Selen Alpergin
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Danielle M Smith
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Guanghui Han
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Junfeng Ma
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - C Conover Talbot
- Institute for Basic Biomedical Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Ping Hu
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Michael J Wolfgang
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Gerald W Hart
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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18
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Akimoto Y, Yan K, Miura Y, Tsumoto H, Toda T, Fukutomi T, Sugahara D, Kudo A, Arai T, Chiba Y, Kaname S, Hart GW, Endo T, Kawakami H. O-GlcNAcylation and phosphorylation of β-actin Ser 199 in diabetic nephropathy. Am J Physiol Renal Physiol 2019; 317:F1359-F1374. [PMID: 31566433 PMCID: PMC6879942 DOI: 10.1152/ajprenal.00566.2018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 08/28/2019] [Accepted: 09/08/2019] [Indexed: 12/18/2022] Open
Abstract
The function of actin is regulated by various posttranslational modifications. We have previously shown that in the kidneys of nonobese type 2 diabetes model Goto-Kakizaki rats, increased O-GlcNAcylation of β-actin protein is observed. It has also been reported that both O-GlcNAcylation and phosphorylation occur on Ser199 of β-actin. However, their roles are not known. To elucidate their roles in diabetic nephropathy, we examined the rat kidney for changes in O-GlcNAcylation of Ser199 (gS199)-actin and in the phosphorylation of Ser199 (pS199)-actin. Both gS199- and pS199-actin molecules had an apparent molecular weight of 40 kDa and were localized as nonfilamentous actin in both the cytoplasm and nucleus. Compared with the normal kidney, the immunostaining intensity of gS199-actin increased in podocytes of the glomeruli and in proximal tubules of the diabetic kidney, whereas that of pS199-actin did not change in podocytes but decreased in proximal tubules. We confirmed that the same results could be observed in the glomeruli of the human diabetic kidney. In podocytes of glomeruli cultured in the presence of the O-GlcNAcase inhibitor Thiamet G, increased O-GlcNAcylation was accompanied by a concomitant decrease in the amount of filamentous actin and in morphological changes. Our present results demonstrate that dysregulation of O-GlcNAcylation and phosphorylation of Ser199 occurred in diabetes, which may contribute partially to the causes of the morphological changes in the glomeruli and tubules. gS199- and pS199-actin will thus be useful for the pathological evaluation of diabetic nephropathy.
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Affiliation(s)
- Yoshihiro Akimoto
- Department of Anatomy, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
| | - Kunimasa Yan
- Department of Pediatrics, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
| | - Yuri Miura
- Research Team for Mechanism of Aging, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan
| | - Hiroki Tsumoto
- Research Team for Mechanism of Aging, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan
| | - Tosifusa Toda
- Research Team for Mechanism of Aging, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan
| | - Toshiyuki Fukutomi
- Department of Pharmacology and Toxicology, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
| | - Daisuke Sugahara
- Department of Anatomy, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
| | - Akihiko Kudo
- Department of Anatomy, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
| | - Tomio Arai
- Department of Pathology, Tokyo Metropolitan Geriatric Hospital, Itabashi, Tokyo, Japan
| | - Yuko Chiba
- Department of Diabetes, Metabolism and Endocrinology, Tokyo Metropolitan Geriatric Hospital, Itabashi, Tokyo, Japan
| | - Shinya Kaname
- Department of Nephrology and Rheumatology, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
| | - Gerald W Hart
- Center for Complex Carbohydrates, University of Georgia, Athens, Georgia
| | - Tamao Endo
- Research Team for Mechanism of Aging, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan
| | - Hayato Kawakami
- Department of Anatomy, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
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Ma J, Wang WH, Li Z, Shabanowitz J, Hunt DF, Hart GW. O-GlcNAc Site Mapping by Using a Combination of Chemoenzymatic Labeling, Copper-Free Click Chemistry, Reductive Cleavage, and Electron-Transfer Dissociation Mass Spectrometry. Anal Chem 2019; 91:2620-2625. [PMID: 30657688 PMCID: PMC6756848 DOI: 10.1021/acs.analchem.8b05688] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
As a dynamic post-translational modification, O-linked β- N-acetylglucosamine ( O-GlcNAc) modification (i.e., O-GlcNAcylation) of proteins regulates many biological processes involving cellular metabolism and signaling. However, O-GlcNAc site mapping, a prerequisite for site-specific functional characterization, has been a challenge since its discovery. Herein we present a novel method for O-GlcNAc enrichment and site mapping. In this method, the O-GlcNAc moiety on peptides was labeled with UDP-GalNAz followed by copper-free azide-alkyne cycloaddition with a multifunctional reagent bearing a terminal cyclooctyne, a disulfide bridge, and a biotin handle. The tagged peptides were then released from NeutrAvidin beads upon reductant treatment, alkylated with (3-acrylamidopropyl)trimethylammonium chloride, and subjected to electron-transfer dissociation mass spectrometry analysis. After validation by using standard synthetic peptide gCTD and model protein α-crystallin, such an approach was applied to the site mapping of overexpressed TGF-β-activated kinase 1/MAP3K7 binding protein 2 (TAB2), with four O-GlcNAc sites unambiguously identified. Our method provides a promising tool for the site-specific characterization of O-GlcNAcylation of important proteins.
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Affiliation(s)
- Junfeng Ma
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
| | - Wei-Han Wang
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Zengxia Li
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Jeffrey Shabanowitz
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Donald F. Hunt
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
- Department of Pathology, Health Sciences Center, University of Virginia, Charlottesville, Virginia 22908, United States
| | - Gerald W. Hart
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
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Abstract
In the early 1980s, while using purified glycosyltransferases to probe glycan structures on surfaces of living cells in the murine immune system, we discovered a novel form of serine/threonine protein glycosylation (O-linked β-GlcNAc; O-GlcNAc) that occurs on thousands of proteins within the nucleus, cytoplasm, and mitochondria. Prior to this discovery, it was dogma that protein glycosylation was restricted to the luminal compartments of the secretory pathway and on extracellular domains of membrane and secretory proteins. Work in the last 3 decades from several laboratories has shown that O-GlcNAc cycling serves as a nutrient sensor to regulate signaling, transcription, mitochondrial activity, and cytoskeletal functions. O-GlcNAc also has extensive cross-talk with phosphorylation, not only at the same or proximal sites on polypeptides, but also by regulating each other's enzymes that catalyze cycling of the modifications. O-GlcNAc is generally not elongated or modified. It cycles on and off polypeptides in a time scale similar to phosphorylation, and both the enzyme that adds O-GlcNAc, the O-GlcNAc transferase (OGT), and the enzyme that removes O-GlcNAc, O-GlcNAcase (OGA), are highly conserved from C. elegans to humans. Both O-GlcNAc cycling enzymes are essential in mammals and plants. Due to O-GlcNAc's fundamental roles as a nutrient and stress sensor, it plays an important role in the etiologies of chronic diseases of aging, including diabetes, cancer, and neurodegenerative disease. This review will present an overview of our current understanding of O-GlcNAc's regulation, functions, and roles in chronic diseases of aging.
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Affiliation(s)
- Gerald W Hart
- From the Complex Carbohydrate Research Center and Biochemistry and Molecular Biology Department, University of Georgia, Athens, Georgia 30602
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21
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Liu W, Han G, Yin Y, Jiang S, Yu G, Yang Q, Yu W, Ye X, Su Y, Yang Y, Hart GW, Sun H. AANL (Agrocybe aegerita lectin 2) is a new facile tool to probe for O-GlcNAcylation. Glycobiology 2018; 28:363-373. [PMID: 29562282 PMCID: PMC6454498 DOI: 10.1093/glycob/cwy029] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2017] [Revised: 03/10/2018] [Accepted: 03/16/2018] [Indexed: 01/26/2023] Open
Abstract
O-linked N-acetylglucosamine (O-GlcNAcylation) is an important post-translational modification on serine or threonine of proteins, mainly observed in nucleus or cytoplasm. O-GlcNAcylation regulates many cell processes, including transcription, cell cycle, neural development and nascent polypeptide chains stabilization. However, the facile identification of O-GlcNAc is a major bottleneck in O-GlcNAcylation research. Herein, we report that a lectin, Agrocybe aegerita GlcNAc-specific lectin (AANL), also reported as AAL2, can be used as a powerful probe for O-GlcNAc identification. Glycan array analyses and surface plasmon resonance (SPR) assays show that AANL binds to GlcNAc with a dissociation constant (KD) of 94.6 μM, which is consistent with the result tested through isothiocyanate (ITC) assay reported before (Jiang S, Chen Y, Wang M, Yin Y, Pan Y, Gu B, Yu G, Li Y, Wong BH, Liang Y, et al. 2012. A novel lectin from Agrocybe aegerita shows high binding selectivity for terminal N-acetylglucosamine. Biochem J. 443:369-378.). Confocal imaging shows that AANL co-localizes extensively with NUP62, a heavily O-GlcNAcylated and abundant nuclear pore glycoprotein. Furthermore, O-GlcNAc-modified peptides could be effectively enriched in the late flow-through peak from simple samples by using affinity columns Sepharose 4B-AANL or POROS-AANL. Therefore, using AANL affinity column, we identified 28 high-confidence O-linked HexNAc-modified peptides mapped on 17 proteins involving diverse cellular progresses, including transcription, hydrolysis progress, urea cycle, alcohol metabolism and cell cycle. And most importantly, major proteins and sites were not annotated in the dbOGAP database. These results suggest that the AANL lectin is a new useful tool for enrichment and identification of O-GlcNAcylated proteins and peptides.
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Affiliation(s)
- Wei Liu
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University
| | - Guanghui Han
- Department of Biological Chemistry, the Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Yalin Yin
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University
| | - Shuai Jiang
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University
| | - Guojun Yu
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University
| | - Qing Yang
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University
| | - Wenhui Yu
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University
| | - Xiangdong Ye
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University
| | - Yanting Su
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University
| | - Yajun Yang
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University
| | - Gerald W Hart
- Department of Biological Chemistry, the Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Hui Sun
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University
- Hubei Province key Laboratory of Allergy and Immunology
- Key laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, Wuhan University, Wuhan 430071, Hubei Province, P. R. China
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Affiliation(s)
- Gerald W. Hart
- Biological ChemistryJohns Hopkins Univ. Sch. Of Med.BaltimoreMD
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Akimoto Y, Yan K, Miura Y, Toda T, Fukutomi T, Sugahara D, Kudo A, Hart GW, Endo T, Kawakami H. PB-05Localization of the O-GlcNAcylated Actin and O-phosphorylated Actin in the Diabetic Kidney: Immunohistochemical Study. Microscopy (Oxf) 2017. [DOI: 10.1093/jmicro/dfx106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
| | - Kunimasa Yan
- Department of Pediatrics, 181-8611, Tokyo, Japan,
| | - Yuri Miura
- Tokyo Metropolitan Institute of Gerontology, Research Team for Mechanism of Aging, 173-0015, Tokyo, Japan,
| | - Tosifusa Toda
- Yokohama City University, Advanced Medical Research Center, 36-0004, Yokohama, Japan,
| | - Toshiyuki Fukutomi
- Kyorin University School of Medicine, Department of Pharmacology and Toxicology, 181-8611, Tokyo, Japan
| | | | - Akihiko Kudo
- Kyorin University School of Medicine, Department of Anatomy,
| | - Gerald W Hart
- Johns Hopkins University School of Medicine, Department of Biological Chemistry, 21205, Baltimore, USA
| | - Tamao Endo
- Tokyo Metropolitan Institute of Gerontology, Research Team for Mechanism of Aging, 173-0015, Tokyo, Japan,
| | - Hayato Kawakami
- Kyorin University School of Medicine, Department of Anatomy,
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Abstract
O-linked β-D-N-acetyl glucosamine (O-GlcNAc) addition (O-GlcNAcylation), a post-translational modification of serine/threonine residues of proteins, is involved in diverse cellular metabolic and signaling pathways. Aberrant O-GlcNAcylation underlies the initiation and progression of multiple chronic diseases including diabetes, cancer, and neurodegenerative diseases. Numerous methods have been developed for the analysis of protein O-GlcNAcylation, but instead of discussing the classical biochemical techniques, this unit covers O-GlcNAc characterization by combining several enrichment methods and mass spectrometry detection techniques [including collision-induced dissociation (CID), higher energy collision dissociation (HCD), and electron transfer dissociation (ETD) mass spectrometry]. © 2017 by John Wiley & Sons, Inc.
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Affiliation(s)
- Junfeng Ma
- Department of Biological Chemistry, The Johns Hopkins University, School of Medicine, Baltimore, Maryland
| | - Gerald W Hart
- Department of Biological Chemistry, The Johns Hopkins University, School of Medicine, Baltimore, Maryland
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Ma J, Banerjee P, Whelan SA, Liu T, Wei AC, Genaro Ramirez-Correa, McComb ME, Costello CE, O’Rourke B, Murphy A, Hart GW. Comparative Proteomics Reveals Dysregulated Mitochondrial O-GlcNAcylation in Diabetic Hearts. J Proteome Res 2016; 15:2254-64. [PMID: 27213235 PMCID: PMC7814404 DOI: 10.1021/acs.jproteome.6b00250] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
O-linked β-N-acetylglucosamine (O-GlcNAc), a post-translational modification on serine and threonine residues of many proteins, plays crucial regulatory roles in diverse biological events. As a nutrient sensor, O-GlcNAc modification (O-GlcNAcylation) on nuclear and cytoplasmic proteins underlies the pathology of diabetic complications including cardiomyopathy. However, mitochondrial O-GlcNAcylation, especially in response to chronic hyperglycemia in diabetes, has been poorly explored. We performed a comparative O-GlcNAc profiling of mitochondria from control and streptozotocin (STZ)-induced diabetic rat hearts by using an improved β-elimination/Michael addition with isotopic DTT reagents (BEMAD) followed by tandem mass spectrometric analysis. In total, 86 mitochondrial proteins, involved in diverse pathways, were O-GlcNAcylated. Among them, many proteins have site-specific alterations in O-GlcNAcylation in response to diabetes, which suggests that protein O-GlcNAcylation is a novel layer of regulation mediating adaptive changes in mitochondrial metabolism during the progression of diabetic cardiomyopathy.
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Affiliation(s)
- Junfeng Ma
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
| | - Partha Banerjee
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
| | - Stephen A. Whelan
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118, United States
| | - Ting Liu
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
| | - An-Chi Wei
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
| | - Genaro Ramirez-Correa
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
| | - Mark E. McComb
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118, United States
| | - Catherine E. Costello
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118, United States
| | - Brian O’Rourke
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
| | - Anne Murphy
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
| | - Gerald W. Hart
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
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Hardivillé S, Hart GW. Nutrient regulation of gene expression by O-GlcNAcylation of chromatin. Curr Opin Chem Biol 2016; 33:88-94. [PMID: 27322399 DOI: 10.1016/j.cbpa.2016.06.005] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 05/31/2016] [Accepted: 06/01/2016] [Indexed: 12/25/2022]
Abstract
O-GlcNAcylation is a dynamic post-translational modification that is responsive to nutrient availably via the hexosamine biosynthetic pathway and its endproduct UDP-GlcNAc. O-GlcNAcylation serves as a nutrient sensor to regulate the activities of many proteins involved in nearly all biological processes. Within the last decade, OGT, OGA and O-GlcNAcylation have been shown to be at the nexus of epigenetic marks controlling gene expression during embryonic development, cell differentiation, in the maintenance of epigenetic states and in the etiology of epigenetic related diseases. OGT O-GlcNAcylates histones and epigenetic writers/erasers, and regulates gene activation, as well as gene repression. Here, we highlight recent work documenting the important roles O-GlcNAcylation and its cycling enzymes play in the nutrient regulation of epigenetic partners controlling gene expression.
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Affiliation(s)
- Stéphan Hardivillé
- Department of Biological Chemistry, Johns Hopkins University, School of Medicine, 725 N. Wolfe St., Baltimore, MD 21205-2185, USA.
| | - Gerald W Hart
- Department of Biological Chemistry, Johns Hopkins University, School of Medicine, 725 N. Wolfe St., Baltimore, MD 21205-2185, USA.
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Banerjee PS, Lagerlöf O, Hart GW. Roles of O-GlcNAc in chronic diseases of aging. Mol Aspects Med 2016; 51:1-15. [PMID: 27259471 DOI: 10.1016/j.mam.2016.05.005] [Citation(s) in RCA: 98] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 05/18/2016] [Accepted: 05/30/2016] [Indexed: 12/22/2022]
Abstract
O-GlcNAcylation, a dynamic nutrient and stress sensitive post-translational modification, occurs on myriad proteins in the cell nucleus, cytoplasm and mitochondria. O-GlcNAcylation serves as a nutrient sensor to regulate signaling, transcription, translation, cell division, metabolism, and stress sensitivity in all cells. Aberrant protein O-GlcNAcylation plays a critical role both in the development, as well as in the progression of a variety of age related diseases. O-GlcNAcylation underlies the etiology of diabetes, and changes in specific protein O-GlcNAc levels and sites are responsible for insulin expression and sensitivity and glucose toxicity. Abnormal O-GlcNAcylation contributes directly to diabetes related dysfunction of the heart, kidney and eyes and affects progression of cardiomyopathy, nephropathy and retinopathy. O-GlcNAcylation is a critical modification in the brain and plays a role in both plaque and tangle formation, thus making its study important in neurodegenerative disorders. O-GlcNAcylation also affects cellular growth and metabolism during the development and metastasis of cancer. Finally, alterations in O-GlcNAcylation of transcription factors in macrophages and lymphocytes affect inflammation and cytokine production. Thus, O-GlcNAcylation plays key roles in many of the major diseases associated with aging. Elucidation of its specific functions in both normal and diseased tissues is likely to uncover totally novel avenues for therapeutic intervention.
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Affiliation(s)
- Partha S Banerjee
- Department of Biological Chemistry, Johns Hopkins School of Medicine, 725 N. Wolfe St., Baltimore, MD 21205-2185
| | - Olof Lagerlöf
- Department of Biological Chemistry, Johns Hopkins School of Medicine, 725 N. Wolfe St., Baltimore, MD 21205-2185
| | - Gerald W Hart
- Department of Biological Chemistry, Johns Hopkins School of Medicine, 725 N. Wolfe St., Baltimore, MD 21205-2185.
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Abstract
Maintaining energy homeostasis is crucial for the survival and health of organisms. The brain regulates feeding by responding to dietary factors and metabolic signals from peripheral organs. It is unclear how the brain interprets these signals. O-GlcNAc transferase (OGT) catalyzes the posttranslational modification of proteins by O-GlcNAc and is regulated by nutrient access. Here, we show that acute deletion of OGT from αCaMKII-positive neurons in adult mice caused obesity from overeating. The hyperphagia derived from the paraventricular nucleus (PVN) of the hypothalamus, where loss of OGT was associated with impaired satiety. These results identify O-GlcNAcylation in αCaMKII neurons of the PVN as an important molecular mechanism that regulates feeding behavior.
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Affiliation(s)
- Olof Lagerlöf
- Solomon H. Snyder Department of Neuroscience, Kavli Neuroscience Discovery Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA. Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Julia E Slocomb
- National Institute on Drug Abuse + National Institutes of Health/Johns Hopkins University Graduate Partnership Program, Baltimore, MD 21224, USA
| | - Ingie Hong
- Solomon H. Snyder Department of Neuroscience, Kavli Neuroscience Discovery Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Yeka Aponte
- Solomon H. Snyder Department of Neuroscience, Kavli Neuroscience Discovery Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA. Intramural Research Program, Neuronal Circuits and Behavior Unit, National Institute on Drug Abuse, Baltimore, MD 21224, USA
| | - Seth Blackshaw
- Solomon H. Snyder Department of Neuroscience, Kavli Neuroscience Discovery Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Gerald W Hart
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Richard L Huganir
- Solomon H. Snyder Department of Neuroscience, Kavli Neuroscience Discovery Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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Hart GW, Schnaar RL, Haltiwanger RS. A Quarter Century of Glycobiology. Glycobiology 2015; 25:1321-2. [PMID: 26543185 DOI: 10.1093/glycob/cwv090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Ma J, Liu T, Wei AC, Banerjee P, O'Rourke B, Hart GW. O-GlcNAcomic Profiling Identifies Widespread O-Linked β-N-Acetylglucosamine Modification (O-GlcNAcylation) in Oxidative Phosphorylation System Regulating Cardiac Mitochondrial Function. J Biol Chem 2015; 290:29141-53. [PMID: 26446791 DOI: 10.1074/jbc.m115.691741] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Indexed: 11/06/2022] Open
Abstract
Dynamic cycling of O-linked β-N-acetylglucosamine (O-GlcNAc) on nucleocytoplasmic proteins serves as a nutrient sensor to regulate numerous biological processes. However, mitochondrial protein O-GlcNAcylation and its effects on function are largely unexplored. In this study, we performed a comparative analysis of the proteome and O-GlcNAcome of cardiac mitochondria from rats acutely (12 h) treated without or with thiamet-G (TMG), a potent and specific inhibitor of O-GlcNAcase. We then determined the functional consequences in mitochondria isolated from the two groups. O-GlcNAcomic profiling finds that over 88 mitochondrial proteins are O-GlcNAcylated, with the oxidative phosphorylation system as a major target. Moreover, in comparison with controls, cardiac mitochondria from TMG-treated rats did not exhibit altered protein abundance but showed overall elevated O-GlcNAcylation of many proteins. However, O-GlcNAc was unexpectedly down-regulated at certain sites of specific proteins. Concomitantly, TMG treatment resulted in significantly increased mitochondrial oxygen consumption rates, ATP production rates, and enhanced threshold for permeability transition pore opening by Ca(2+). Our data reveal widespread and dynamic mitochondrial protein O-GlcNAcylation, serving as a regulator to their function.
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Affiliation(s)
- Junfeng Ma
- From the Department of Biological Chemistry and
| | - Ting Liu
- Division of Cardiology, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - An-Chi Wei
- Division of Cardiology, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | | | - Brian O'Rourke
- Division of Cardiology, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
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Ramirez-Correa GA, Ma J, Slawson C, Zeidan Q, Lugo-Fagundo NS, Xu M, Shen X, Gao WD, Caceres V, Chakir K, DeVine L, Cole RN, Marchionni L, Paolocci N, Hart GW, Murphy AM. Removal of Abnormal Myofilament O-GlcNAcylation Restores Ca2+ Sensitivity in Diabetic Cardiac Muscle. Diabetes 2015; 64:3573-87. [PMID: 26109417 PMCID: PMC4587639 DOI: 10.2337/db14-1107] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Accepted: 05/14/2015] [Indexed: 11/13/2022]
Abstract
Contractile dysfunction and increased deposition of O-linked β-N-acetyl-d-glucosamine (O-GlcNAc) in cardiac proteins are a hallmark of the diabetic heart. However, whether and how this posttranslational alteration contributes to lower cardiac function remains unclear. Using a refined β-elimination/Michael addition with tandem mass tags (TMT)-labeling proteomic technique, we show that CpOGA, a bacterial analog of O-GlcNAcase (OGA) that cleaves O-GlcNAc in vivo, removes site-specific O-GlcNAcylation from myofilaments, restoring Ca(2+) sensitivity in streptozotocin (STZ) diabetic cardiac muscles. We report that in control rat hearts, O-GlcNAc and O-GlcNAc transferase (OGT) are mainly localized at the Z-line, whereas OGA is at the A-band. Conversely, in diabetic hearts O-GlcNAc levels are increased and OGT and OGA delocalized. Consistent changes were found in human diabetic hearts. STZ diabetic hearts display increased physical interactions of OGA with α-actin, tropomyosin, and myosin light chain 1, along with reduced OGT and increased OGA activities. Our study is the first to reveal that specific removal of O-GlcNAcylation restores myofilament response to Ca(2+) in diabetic hearts and that altered O-GlcNAcylation is due to the subcellular redistribution of OGT and OGA rather than to changes in their overall activities. Thus, preventing sarcomeric OGT and OGA displacement represents a new possible strategy for treating diabetic cardiomyopathy.
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Affiliation(s)
- Genaro A Ramirez-Correa
- Division of Cardiology, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Junfeng Ma
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Chad Slawson
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS
| | - Quira Zeidan
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Nahyr S Lugo-Fagundo
- Division of Cardiology, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Mingguo Xu
- Division of Cardiology, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Xiaoxu Shen
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Wei Dong Gao
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Viviane Caceres
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Khalid Chakir
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Lauren DeVine
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Robert N Cole
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Luigi Marchionni
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Nazareno Paolocci
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Gerald W Hart
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Anne M Murphy
- Division of Cardiology, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD
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Affiliation(s)
- Naoyuki Taniguchi
- Systems Glycobiology Research Group, RIKEN-Max Planck Joint Research Center for Systems Chemical Biology, Wako, Saitama Japan
| | - Tamao Endo
- Tokyo Metropolitan Institute of Gerontology, Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, Tokyo, Japan
| | - Gerald W. Hart
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, Maryland USA
| | - Peter H. Seeberger
- Department of Biomolecular Systems, Max-Planck-Institute of Colloids and Interfaces, Potsdam, Germany
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Affiliation(s)
- Gerald W Hart
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205-2185, USA.
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Hart GW. Minireview series on the thirtieth anniversary of research on O-GlcNAcylation of nuclear and cytoplasmic proteins: Nutrient regulation of cellular metabolism and physiology by O-GlcNAcylation. J Biol Chem 2014; 289:34422-3. [PMID: 25336646 DOI: 10.1074/jbc.r114.609776] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The dynamic cycling of N-acetylglucosamine (termed O-GlcNAcylation) on serine or threonine residues of nuclear or cytoplasmic proteins serves as a nutrient sensor, both independently and also via its interplay with other post-translational modifications, to regulate signaling, transcription, and cellular physiology. Emerging evidence suggests that dysregulation of this ubiquitous post-translational modification contributes to the etiology of some the most important human chronic diseases.
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Affiliation(s)
- Gerald W Hart
- From the Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205-2185
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Abstract
The post-translational modification of serine and threonine residues of proteins by O-linked β-N-acetylglucosamine (O-GlcNAc) is highly ubiquitous, dynamic and inducible. Protein O-GlcNAcylation serves as a key regulator of critical biological processes including transcription, translation, proteasomal degradation, signal transduction and apoptosis. Increased O-GlcNAcylation is directly linked to insulin resistance and to hyperglycemia-induced glucose toxicity, two hallmarks of diabetes and diabetic complications. In this review, we briefly summarize what is known about protein O-GlcNAcylation and nutrient metabolism, as well as discuss the commonly used tools to probe changes of O-GlcNAcylation in cultured cells and in animal models. We then focus on some key proteins modified by O-GlcNAc, which play crucial roles in the etiology and progression of diabetes and diabetic complications. Proteomic approaches are also highlighted to provide a system view of protein O-GlcNAcylation. Finally, we discuss how aberrant O-GlcNAcylation on certain proteins may be exploited to develop methods for the early diagnosis of pre-diabetes and/or diabetes.
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Affiliation(s)
- Junfeng Ma
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, MD 21205-2185, USA
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38
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Abstract
O-linked β-D-N-acetylglucosamine (O-GlcNAc) modification (O-GlcNAcylation) onto serine and threonine residues of proteins is an important post-translational modification (PTM), which is involved in many crucial biological processes including transcription, translation, proteasomal degradation, and signal transduction. Aberrant protein O-GlcNAcylation is directly linked to the pathological progression of chronic diseases including diabetes, cancer, and neurodegenerative disorders. Identification, site mapping, and quantification of O-GlcNAc proteins are a prerequisite to decipher their functions. In this review, we mainly focus on technological developments regarding O-GlcNAc protein profiling. Specifically, on one hand, we show how these techniques are being used for the comprehensive characterization of certain targeted proteins in which biologists are most interested. On the other hand, we present several newly developed approaches for O-GlcNAcomic profiling as well as how they provide us with a systems perspective to crosstalk amongst different PTMs and complicated biological events. Promising technical trends are also highlighted to evoke more efforts by diverse laboratories, which would further expand our understanding of the physiological and pathological roles of protein O-GlcNAcylation in chronic diseases.
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Affiliation(s)
| | - Gerald W Hart
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, MD 21205-2185, USA.
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Bullen JW, Balsbaugh JL, Chanda D, Shabanowitz J, Hunt DF, Neumann D, Hart GW. Cross-talk between two essential nutrient-sensitive enzymes: O-GlcNAc transferase (OGT) and AMP-activated protein kinase (AMPK). J Biol Chem 2014; 289:10592-10606. [PMID: 24563466 DOI: 10.1074/jbc.m113.523068] [Citation(s) in RCA: 141] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Nutrient-sensitive pathways regulate both O-GlcNAc transferase (OGT) and AMP-activated protein kinase (AMPK), cooperatively connecting metabolic homeostasis to regulation of numerous intracellular processes essential for life. Similar to phosphorylation, catalyzed by kinases such as AMPK, O-GlcNAcylation is a highly dynamic Ser/Thr-specific post-translational modification of nuclear, cytoplasmic, and mitochondrial proteins catalyzed exclusively by OGT. OGT and AMPK target a multitude of intracellular proteins, with the net effect to protect cells from the damaging effects of metabolic stress. Despite hundreds of studies demonstrating significant overlap in upstream and downstream signaling processes, no study has investigated if OGT and AMPK can directly regulate each other. We show acute activation of AMPK alters the substrate selectivity of OGT in several cell lines and nuclear localization of OGT in C2C12 skeletal muscle myotubes. Nuclear localization of OGT affects O-GlcNAcylation of numerous nuclear proteins and acetylation of Lys-9 on histone 3 in myotubes. AMPK phosphorylates Thr-444 on OGT in vitro; phosphorylation of Thr-444 is tightly associated with AMPK activity and nuclear localization of OGT in myotubes, and phospho-mimetic T444E-OGT exhibits altered substrate selectivity. Conversely, the α- and γ-subunits of AMPK are O-GlcNAcylated, O-GlcNAcylation of the γ1-subunit increases with AMPK activity, and acute inhibition of O-GlcNAc cycling disrupts activation of AMPK. We have demonstrated significant cross-talk between the O-GlcNAc and AMPK systems, suggesting OGT and AMPK may cooperatively regulate nutrient-sensitive intracellular processes that mediate cellular metabolism, growth, proliferation, and/or tissue function.
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Affiliation(s)
- John W Bullen
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Jeremy L Balsbaugh
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904
| | - Dipanjan Chanda
- Department of Molecular Genetics, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, 6200 MD Maastricht, The Netherlands
| | - Jeffrey Shabanowitz
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904
| | - Donald F Hunt
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904; Department of Pathology, University of Virginia, Charlottesville, Virginia 22904
| | - Dietbert Neumann
- Department of Molecular Genetics, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, 6200 MD Maastricht, The Netherlands
| | - Gerald W Hart
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205.
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Semba RD, Huang H, Lutty GA, Van Eyk JE, Hart GW. The role of O-GlcNAc signaling in the pathogenesis of diabetic retinopathy. Proteomics Clin Appl 2014; 8:218-31. [PMID: 24550151 DOI: 10.1002/prca.201300076] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Revised: 09/24/2013] [Accepted: 10/04/2013] [Indexed: 12/14/2022]
Abstract
Diabetic retinopathy is a leading cause of blindness worldwide. Despite laser and surgical treatments, antiangiogenic and other therapies, and strict metabolic control, many patients progress to visual impairment and blindness. New insights are needed into the pathophysiology of diabetic retinopathy in order to develop new methods to improve the detection and treatment of disease and the prevention of blindness. Hyperglycemia and diabetes result in increased flux through the hexosamine biosynthetic pathway, which, in turn, results in increased PTM of Ser/Thr residues of proteins by O-linked β-N-acetylglucosamine (O-GlcNAc). O-GlcNAcylation is involved in regulation of many nuclear and cytoplasmic proteins in a manner similar to protein phosphorylation. Altered O-GlcNAc signaling has been implicated in the pathogenesis of diabetes and may play an important role in the pathogenesis of diabetic retinopathy. The goal of this review is to summarize the biology of the hexosamine biosynthesis pathway and O-GlcNAc signaling, to present the current evidence for the role of O-GlcNAc signaling in diabetes and diabetic retinopathy, and to discuss future directions for research on O-GlcNAc in the pathogenesis of diabetic retinopathy.
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Affiliation(s)
- Richard D Semba
- Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
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Hart GW. Three Decades of Research on O-GlcNAcylation - A Major Nutrient Sensor That Regulates Signaling, Transcription and Cellular Metabolism. Front Endocrinol (Lausanne) 2014; 5:183. [PMID: 25386167 PMCID: PMC4209869 DOI: 10.3389/fendo.2014.00183] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Accepted: 10/10/2014] [Indexed: 12/31/2022] Open
Abstract
Even though the dynamic modification of polypeptides by the monosaccharide, O-linked N-acetylglucosamine (O-GlcNAcylation) was discovered over 30 years ago, its physiological significance as a major nutrient sensor that regulates myriad cellular processes has only recently been more widely appreciated. O-GlcNAcylation, either on its own or by its interplay with other post-translational modifications, such as phosphorylation, ubiquitination, and others, modulates the activities of signaling proteins, regulates most components of the transcription machinery, affects cell cycle progression and regulates the targeting/turnover or functions of myriad other regulatory proteins, in response to nutrients. Acute increases in O-GlcNAcylation protect cells from stress-induced injury, while chronic deregulation of O-GlcNAc cycling contributes to the etiology of major human diseases of aging, such as diabetes, cancer, and neurodegeneration. Recent advances in tools to study O-GlcNAcylation at the individual site level and specific inhibitors of O-GlcNAc cycling have allowed more rapid progress toward elucidating the specific functions of O-GlcNAcylation in essential cellular processes.
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Affiliation(s)
- Gerald W. Hart
- Department of Biological Chemistry, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
- *Correspondence: Gerald W. Hart, Department of Biological Chemistry, School of Medicine, Johns Hopkins University, WBSB515, 725 North Wolfe Street, Baltimore, MD 21205-2185, USA e-mail:
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Affiliation(s)
- Gerald W Hart
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205-2185
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Erickson JR, Pereira L, Wang L, Han G, Ferguson A, Dao K, Copeland RJ, Despa F, Hart GW, Ripplinger CM, Bers DM. Diabetic hyperglycaemia activates CaMKII and arrhythmias by O-linked glycosylation. Nature 2013; 502:372-6. [PMID: 24077098 PMCID: PMC3801227 DOI: 10.1038/nature12537] [Citation(s) in RCA: 452] [Impact Index Per Article: 41.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Accepted: 08/12/2013] [Indexed: 01/26/2023]
Abstract
Ca2+-Calmodulin dependent protein kinase II (CaMKII) is a regulatory node in heart and brain, and its chronic activation can be pathological. CaMKII activation seen in heart failure can directly induce pathological changes in ion channels, Ca2+ handling and gene transcription.1 Here we discover a novel mechanism linking CaMKII and hyperglycemic signaling in diabetes mellitus, which is a key risk factor for heart2 and neurodegenerative diseases.3,4 Acute hyperglycemia causes covalent modification of CaMKII by O-linked N-acetylglucosamine (O-GlcNAc). O-GlcNAc modification of CaMKII at Ser-279 activates CaMKII autonomously, creating molecular memory even after [Ca2+] declines. O-GlcNAc modified CaMKII is increased in heart and brain from diabetic humans and rats. In cardiomyocytes, increased [glucose] significantly enhances CaMKII-dependent activation of spontaneous sarcoplasmic reticulum (SR) Ca2+ release events that can contribute to cardiac mechanical dysfunction and arrhythmias.1 These effects were prevented by pharmacological inhibition of O-GlcNAc signaling or genetic ablation of CaMKIIδ. In intact perfused hearts, arrhythmias were enhanced by increased [glucose] via O-GlcNAc-and CaMKII-dependent pathways. In diabetic animals, acute blockade of O-GlcNAc inhibited arrhythmogenesis. Thus, O-GlcNAc modification of CaMKII is a novel signaling event in pathways that may contribute critically to cardiac and neuronal pathophysiology in diabetes and other diseases.
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Affiliation(s)
- Jeffrey R Erickson
- Department of Pharmacology, University of California, Davis, Davis, California 95616, USA
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Abstract
Nutrients regulate gene transcription by the dynamic cycling of O-linked N-acetylglucosamine (O-GlcNAc) on proteins that constitute the transcriptional machinery. A study shows that O-GlcNAcylation of the nuclear factor κB (NF-κB) subunit c-Rel is required for its binding to the promoters of some, but not all, key T cell receptor-dependent genes; however, O-GlcNAcylation is dispensable for the binding of c-Rel to the promoters of tumor necrosis factor-α-dependent genes. This study not only illustrates how specific stimuli that act on the same transcription factor can elicit the expression of particular sets of genes, it also suggests a possible mechanism for autoimmunity in diabetes.
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Affiliation(s)
- Gerald W Hart
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, MD 21205, USA.
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Copeland RJ, Han G, Hart GW. O-GlcNAcomics--Revealing roles of O-GlcNAcylation in disease mechanisms and development of potential diagnostics. Proteomics Clin Appl 2013; 7:597-606. [PMID: 23640805 DOI: 10.1002/prca.201300001] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2013] [Accepted: 01/17/2013] [Indexed: 12/26/2022]
Abstract
O-linked-β-N-acetylglucosamine (O-GlcNAc) is a dynamic PTM of the 3'-hydroxyl groups of serine or threonine residues of nuclear, cytoplasmic, and mitochondrial proteins. The cycling of this modification is regulated in response to nutrients, stress, and other extracellular stimuli by the catalytic activities of O-GlcNAc transferase and O-GlcNAcase. O-GlcNAc is functionally similar to phosphorylation and has been demonstrated to play critical roles in numerous biological processes, including cell signaling, transcription, and disease etiology. Since its discovery nearly 30 years ago, studies have demonstrated that the O-GlcNAc is highly abundant and widespread, like phosphorylation however, the development of methodologies to study O-GlcNAc at the site level has been challenging. Recently, a number of studies have overcome these challenges and describe new tagging, enrichment, and mass spectrometric-based approaches to study O-GlcNAc in terms of its site identification, stoichiometry, and dynamics on proteins. The development of these methods are key for elucidation of O-GlcNAc's functional crosstalk with phosphorylation and other PTMs, and will serve to provide the necessary information for the development of site-specific antibodies, which will aid in the determination of a particular protein's site-specific function. In this review, we describe these methods and summarize results obtained from them demonstrating the roles of O-GlcNAc in diabetes, cancer, Alzheimer's, and in learning and memory, while also describing how these new strategies have implicated O-GlcNAc as a potential diagnostic for the screening of patients for prediabetes.
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Affiliation(s)
- Ronald J Copeland
- Department of Biological Chemistry, School of Medicine, Johns Hopkins University, Baltimore, MD 21205-2185, USA
| | - Guanghui Han
- Department of Biological Chemistry, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Gerald W Hart
- Department of Biological Chemistry, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
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Abstract
While cellular circadian clocks are set by the light/dark cycle, these clocks can be reset by what we eat. Two papers in this issue of Cell Metabolism reveal that O-GlcNAcylation of clock proteins, which is dependent on nutrients, adjusts our circadian clock (Kaasik et al., 2013; Li et al., 2013).
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Affiliation(s)
- Gerald W Hart
- Department of Biological Chemistry, Johns Hopkins University, School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205-2185, USA.
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Affiliation(s)
- Gerald W Hart
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205-2185, USA.
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Abstract
The enzymatic addition of a single β-D-N-acetylglucosamine sugar molecule on serine and/or threonine residues of protein chains is referred to as O-GlcNAcylation. This novel form of post-translational modification, first reported in 1984, is extremely abundant on nuclear and cytoplasmic proteins and has site specific cycling dynamics comparable to that of protein-phosphorylation. A nutrient and stress sensor, O-GlcNAc abnormalities underlie insulin resistance and glucose toxicity in diabetes, neurodegenerative disorders and dysregulation of tumor suppressors and oncogenic proteins in cancer. Recent advances have helped understand the biochemical mechanisms of GlcNAc addition and removal and have opened the door to developing key inhibitors towards this type of protein modification. Advanced methods in detecting and measuring O-GlcNAcylation have assisted in delineating its biological roles in a variety of cellular processes and diseased states. Availability of facile glycomic techniques are allowing for the exponential growth in the study of protein O-GlcNAcylation and are helping to elucidate key biological roles of this novel PTM.
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Affiliation(s)
- Partha S Banerjee
- Department of Biological Chemistry, Johns Hopkins University, School of Medicine, Baltimore 21205-2185, USA
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Ranuncolo SM, Ghosh S, Hanover JA, Hart GW, Lewis BA. Evidence of the involvement of O-GlcNAc-modified human RNA polymerase II CTD in transcription in vitro and in vivo. J Biol Chem 2012; 287:23549-61. [PMID: 22605332 DOI: 10.1074/jbc.m111.330910] [Citation(s) in RCA: 118] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The RNA polymerase II C-terminal domain (CTD), which serves as a scaffold to recruit machinery involved in transcription, is modified post-translationally. Although the O-GlcNAc modification of RNA polymerase II CTD was documented in 1993, its functional significance remained obscure. We show that O-GlcNAc transferase (OGT) modified CTD serine residues 5 and 7. Drug inhibition of OGT and OGA (N-acetylglucosaminidase) blocked transcription during preinitiation complex assembly. Polymerase II and OGT co-immunoprecipitated, and OGT is a component of the preinitiation complex. OGT shRNA experiments showed that reduction of OGT causes a reduction in transcription and RNA polymerase II occupancy at several B-cell promoters. These data suggest that the cycling of O-GlcNAc on and off of polymerase II occurs during assembly of the preinitiation complex. Our results define unexpected roles for both the CTD and O-GlcNAc in the regulation of transcription initiation in higher eukaryotes.
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Affiliation(s)
- Stella M Ranuncolo
- Metabolism Branch, Center for Cancer Research, NCI, National Institutes of Health, Bethesda, Maryland 20892, USA
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