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Sha X, Zou X, Liu S, Guan C, Shi W, Gao J, Zhong X, Jiang X. Forkhead box O1 in metabolic dysfunction-associated fatty liver disease: molecular mechanisms and drug research. Front Nutr 2024; 11:1426780. [PMID: 39021599 PMCID: PMC11253077 DOI: 10.3389/fnut.2024.1426780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2024] [Accepted: 06/21/2024] [Indexed: 07/20/2024] Open
Abstract
Metabolic dysfunction-associated fatty liver disease (MAFLD) is a chronic liver disease that progresses from hepatic steatosis to non-alcoholic steatohepatitis, cirrhosis, and liver cancer, posing a huge burden on human health. Existing research has confirmed that forkhead box O1 (FOXO1), as a member of the FOXO transcription factor family, is upregulated in MAFLD. Its activity is closely related to nuclear-cytoplasmic shuttling and various post-translational modifications including phosphorylation, acetylation, and methylation. FOXO1 mediates the progression of MAFLD by regulating glucose metabolism, lipid metabolism, insulin resistance, oxidative stress, hepatic fibrosis, hepatocyte autophagy, apoptosis, and immune inflammation. This article elaborates on the regulatory role of FOXO1 in MAFLD, providing a summary and new insights for the current status of drug research and targeted therapies for MAFLD.
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Affiliation(s)
| | | | | | | | | | | | - Xiangyu Zhong
- General Surgery Department, The 2nd Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Xingming Jiang
- General Surgery Department, The 2nd Affiliated Hospital of Harbin Medical University, Harbin, China
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2
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Emerging Role of Protein O-GlcNAcylation in Liver Metabolism: Implications for Diabetes and NAFLD. Int J Mol Sci 2023; 24:ijms24032142. [PMID: 36768465 PMCID: PMC9916810 DOI: 10.3390/ijms24032142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 01/16/2023] [Accepted: 01/18/2023] [Indexed: 01/24/2023] Open
Abstract
O-linked b-N-acetyl-glucosaminylation (O-GlcNAcylation) is one of the most common post-translational modifications of proteins, and is established by modifying the serine or threonine residues of nuclear, cytoplasmic, and mitochondrial proteins. O-GlcNAc signaling is considered a critical nutrient sensor, and affects numerous proteins involved in cellular metabolic processes. O-GlcNAcylation modulates protein functions in different patterns, including protein stabilization, enzymatic activity, transcriptional activity, and protein interactions. Disrupted O-GlcNAcylation is associated with an abnormal metabolic state, and may result in metabolic disorders. As the liver is the center of nutrient metabolism, this review provides a brief description of the features of the O-GlcNAc signaling pathway, and summarizes the regulatory functions and underlying molecular mechanisms of O-GlcNAcylation in liver metabolism. Finally, this review highlights the role of O-GlcNAcylation in liver-associated diseases, such as diabetes and nonalcoholic fatty liver disease (NAFLD). We hope this review not only benefits the understanding of O-GlcNAc biology, but also provides new insights for treatments against liver-associated metabolic disorders.
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Protein O-GlcNAcylation and the regulation of energy homeostasis: lessons from knock-out mouse models. J Biomed Sci 2022; 29:64. [PMID: 36058931 PMCID: PMC9443036 DOI: 10.1186/s12929-022-00851-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 08/30/2022] [Indexed: 12/02/2022] Open
Abstract
O-GlcNAcylation corresponds to the addition of N-Acetylglucosamine (GlcNAc) on serine or threonine residues of cytosolic, nuclear and mitochondrial proteins. This reversible modification is catalysed by a unique couple of enzymes, O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA). OGT uses UDP-GlcNAc produced in the hexosamine biosynthesis pathway, to modify proteins. UDP-GlcNAc is at the cross-roads of several cellular metabolisms, including glucose, amino acids and fatty acids. Therefore, OGT is considered as a metabolic sensor that post-translationally modifies proteins according to nutrient availability. O-GlcNAcylation can modulate protein–protein interactions and regulate protein enzymatic activities, stability or subcellular localization. In addition, it can compete with phosphorylation on the same serine or threonine residues, or regulate positively or negatively the phosphorylation of adjacent residues. As such, O-GlcNAcylation is a major actor in the regulation of cell signaling and has been implicated in numerous physiological and pathological processes. A large body of evidence have indicated that increased O-GlcNAcylation participates in the deleterious effects of glucose (glucotoxicity) in metabolic diseases. However, recent studies using mice models with OGT or OGA knock-out in different tissues have shown that O-GlcNAcylation protects against various cellular stresses, and indicate that both increase and decrease in O-GlcNAcylation have deleterious effects on the regulation of energy homeostasis.
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Cai X, Li H, Wang M, Chu E, Wei N, Lin J, Hu Y, Dai J, Chen A, Zheng H, Zhang Q, Zhong Y, Chang R, Wu S, Xiao Y, Liu C. mTOR Participates in the Formation, Maintenance, and Function of Memory CD8 +T Cells Regulated by Glycometabolism. Biochem Pharmacol 2022; 204:115197. [PMID: 35926651 DOI: 10.1016/j.bcp.2022.115197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 07/21/2022] [Accepted: 07/27/2022] [Indexed: 11/02/2022]
Abstract
Memory CD8+T cells participate in the fight against infection and tumorigenesis as well as in autoimmune disease progression because of their efficient and rapid immune response, long-term survival, and continuous differentiation. At each stage of their formation, maintenance, and function, the cell metabolism must be adjusted to match the functional requirements of the specific stage. Notably, enhanced glycolytic metabolism can generate sufficient levels of adenosine triphosphate (ATP) to form memory CD8+T cells, countering the view that glycolysis prevents the formation of memory CD8+T cells. This review focuses on how glycometabolism regulates memory CD8+T cells and highlights the key mechanisms through which the mammalian target of rapamycin (mTOR) signaling pathway affects memory CD8+T cell formation, maintenance, and function by regulating glycometabolism. In addition, different subpopulations of memory CD8+T cells exhibit different metabolic flexibility during their formation, survival, and functional stages, during which the energy metabolism may be critical. These findings which may explain why enhanced glycolytic metabolism can give rise to memory CD8+T cells. Modulating the metabolism of memory CD8+T cells to influence specific cell fates may be useful for disease treatment.
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Affiliation(s)
- Xuepei Cai
- Department of Orthodontics, Stomatological Hospital, Southern Medical University, Guangzhou, China
| | - Haokun Li
- Department of Immunology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Manyi Wang
- Department of Orthodontics, Stomatological Hospital, Southern Medical University, Guangzhou, China
| | - Edward Chu
- Department of Oncology and Cancer Therapeutics Program, Albert Einstein Cancer Center, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Ning Wei
- Department of Oncology and Cancer Therapeutics Program, Albert Einstein Cancer Center, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Jiayu Lin
- Department of Orthodontics, Stomatological Hospital, Southern Medical University, Guangzhou, China
| | - Yun Hu
- Department of Orthodontics, Stomatological Hospital, Southern Medical University, Guangzhou, China
| | - Jingtao Dai
- Department of Orthodontics, Stomatological Hospital, Southern Medical University, Guangzhou, China
| | - Aijie Chen
- Stomatological Hospital, Southern Medical University, Guangzhou, China
| | - Hua Zheng
- Department of Cardiology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Qianbing Zhang
- Cancer Research Institute, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Yuxia Zhong
- Microbiome Medicine Center, Department of Laboratory Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Ruoshui Chang
- Department of Immunology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Sha Wu
- Department of Immunology, School of Basic Medical Sciences, Microbiome Medicine Center, Department of Laboratory Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou, China; Key Laboratory of Functional Proteomics of Guangdong Province, Guangzhou, China; National Demonstration Center for Experimental Education of Basic Medical Sciences of China, Guangzhou, China.
| | - Yaomu Xiao
- Department of Orthodontics, Stomatological Hospital, Southern Medical University, Guangzhou, China.
| | - Chufeng Liu
- Department of Orthodontics, Stomatological Hospital, Southern Medical University, Guangzhou, China.
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5
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Nathanael J, Suardana P, Vianney YM, Dwi Putra SE. The role of FoxO1 and its modulation with small molecules in the development of diabetes mellitus: A review. Chem Biol Drug Des 2021; 99:344-361. [PMID: 34862852 DOI: 10.1111/cbdd.13989] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 11/11/2021] [Accepted: 11/21/2021] [Indexed: 12/14/2022]
Abstract
Diabetes mellitus type 2 (T2D) is one of the metabolic disorders suffered by a global human being. Certain factors, such as lifestyle and heredity, can increase a person's tendency for T2D. Various genes and proteins play a role in the development of insulin resistance and ultimately diabetes in which one central protein that is discussed in this review is FoxO1. In this review, we regard FoxO1 activation as detrimental, promote high plasma glucose level, and induce insulin resistance. Indeed, many contrasting studies arise since FoxO1 is an important protein to alleviate oxidative stress and promote cell survival, for example, also by preventing hyperglycemic-induced cell death. Inter-relation to PPARG, another important protein in metabolism, is also discussed. Ultimately, we discussed contrasting approaches of targeting FoxO1 to combat diabetes mellitus by small molecules.
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Affiliation(s)
- Joshua Nathanael
- Department of Biotechnology, Faculty of Biotechnology, University of Surabaya, Surabaya, East Java, Indonesia
| | - Putu Suardana
- Department of Biotechnology, Faculty of Biotechnology, University of Surabaya, Surabaya, East Java, Indonesia
| | - Yoanes Maria Vianney
- Department of Biotechnology, Faculty of Biotechnology, University of Surabaya, Surabaya, East Java, Indonesia
| | - Sulistyo Emantoko Dwi Putra
- Department of Biotechnology, Faculty of Biotechnology, University of Surabaya, Surabaya, East Java, Indonesia
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6
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Du S, Zheng H. Role of FoxO transcription factors in aging and age-related metabolic and neurodegenerative diseases. Cell Biosci 2021; 11:188. [PMID: 34727995 PMCID: PMC8561869 DOI: 10.1186/s13578-021-00700-7] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Accepted: 10/20/2021] [Indexed: 12/18/2022] Open
Abstract
Aging happens to all of us as we live. Thanks to the improved living standard and discovery of life-saving medicines, our life expectancy has increased substantially across the world in the past century. However, the rise in lifespan leads to unprecedented increases in both the number and the percentage of individuals 65 years and older, accompanied by the increased incidences of age-related diseases such as type 2 diabetes mellitus and Alzheimer’s disease. FoxO transcription factors are evolutionarily conserved molecules that play critical roles in diverse biological processes, in particular aging and metabolism. Their dysfunction is often found in the pathogenesis of many age-related diseases. Here, we summarize the signaling pathways and cellular functions of FoxO proteins. We also review the complex role of FoxO in aging and age-related diseases, with focus on type 2 diabetes and Alzheimer’s disease and discuss the possibility of FoxO as a molecular link between aging and disease risks.
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Affiliation(s)
- Shuqi Du
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX, USA
| | - Hui Zheng
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX, USA.
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Zhang X, Jiang L, Liu H. Forkhead Box Protein O1: Functional Diversity and Post-Translational Modification, a New Therapeutic Target? DRUG DESIGN DEVELOPMENT AND THERAPY 2021; 15:1851-1860. [PMID: 33976536 PMCID: PMC8106445 DOI: 10.2147/dddt.s305016] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 04/19/2021] [Indexed: 11/23/2022]
Abstract
Forkhead box protein O1 (FoXO1) is a transcription factor involved in the regulation of a wide variety of physiological process including glucose metabolism, lipogenesis, bone mass, apoptosis, and autophagy. FoXO1 dysfunction is involved in the pathophysiology of various diseases including metabolic diseases, atherosclerosis, and tumors. FoXO1 activity is regulated in response to different physiological or pathogenic conditions by changes in protein expression and post-translational modifications. Various modifications cooperate to regulate FoXO1 activity and FoXO1 target gene transcription. In this review, we summarize how different post-translational modifications regulate FoXO1 physiological function, which may provide new insights for drug design and development.
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Affiliation(s)
- Xiaojun Zhang
- Department of Cardiology, Shandong Rongjun General Hospital, Jinan, 250013, People's Republic of China
| | - Lusheng Jiang
- Department of Emergency, Shandong Rongjun General Hospital, Jinan, 250013, People's Republic of China
| | - Huimin Liu
- Blood Purification Center, Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, 250011, People's Republic of China
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8
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Acetyl-CoA Metabolism and Histone Acetylation in the Regulation of Aging and Lifespan. Antioxidants (Basel) 2021; 10:antiox10040572. [PMID: 33917812 PMCID: PMC8068152 DOI: 10.3390/antiox10040572] [Citation(s) in RCA: 65] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 03/31/2021] [Accepted: 04/02/2021] [Indexed: 12/16/2022] Open
Abstract
Acetyl-CoA is a metabolite at the crossroads of central metabolism and the substrate of histone acetyltransferases regulating gene expression. In many tissues fasting or lifespan extending calorie restriction (CR) decreases glucose-derived metabolic flux through ATP-citrate lyase (ACLY) to reduce cytoplasmic acetyl-CoA levels to decrease activity of the p300 histone acetyltransferase (HAT) stimulating pro-longevity autophagy. Because of this, compounds that decrease cytoplasmic acetyl-CoA have been described as CR mimetics. But few authors have highlighted the potential longevity promoting roles of nuclear acetyl-CoA. For example, increasing nuclear acetyl-CoA levels increases histone acetylation and administration of class I histone deacetylase (HDAC) inhibitors increases longevity through increased histone acetylation. Therefore, increased nuclear acetyl-CoA likely plays an important role in promoting longevity. Although cytoplasmic acetyl-CoA synthetase 2 (ACSS2) promotes aging by decreasing autophagy in some peripheral tissues, increased glial AMPK activity or neuronal differentiation can stimulate ACSS2 nuclear translocation and chromatin association. ACSS2 nuclear translocation can result in increased activity of CREB binding protein (CBP), p300/CBP-associated factor (PCAF), and other HATs to increase histone acetylation on the promoter of neuroprotective genes including transcription factor EB (TFEB) target genes resulting in increased lysosomal biogenesis and autophagy. Much of what is known regarding acetyl-CoA metabolism and aging has come from pioneering studies with yeast, fruit flies, and nematodes. These studies have identified evolutionary conserved roles for histone acetylation in promoting longevity. Future studies should focus on the role of nuclear acetyl-CoA and histone acetylation in the control of hypothalamic inflammation, an important driver of organismal aging.
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Merovci A, Tripathy D, Chen X, Valdez I, Abdul-Ghani M, Solis-Herrera C, Gastaldelli A, DeFronzo RA. Effect of Mild Physiologic Hyperglycemia on Insulin Secretion, Insulin Clearance, and Insulin Sensitivity in Healthy Glucose-Tolerant Subjects. Diabetes 2021; 70:204-213. [PMID: 33033064 PMCID: PMC7881846 DOI: 10.2337/db20-0039] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 10/06/2020] [Indexed: 12/19/2022]
Abstract
The aim of the current study was to evaluate the effect of sustained physiologic increase of ∼50 mg/dL in plasma glucose concentration on insulin secretion in normal glucose-tolerant (NGT) subjects. Twelve NGT subjects without family history of type 2 diabetes mellitus (T2DM; FH-) and 8 NGT with family history of T2DM (FH+) received an oral glucose tolerance test and two-step hyperglycemic clamp (100 and 300 mg/dL) followed by intravenous arginine bolus before and after 72-h glucose infusion. Fasting plasma glucose increased from 94 ± 2 to 142 ± 4 mg/dL for 72 h. First-phase insulin secretion (0-10 min) increased by 70%, while second-phase insulin secretion during the first (10-80 min) and second (90-160 min) hyperglycemic clamp steps increased by 3.8-fold and 1.9-fold, respectively, following 72 h of physiologic hyperglycemia. Insulin sensitivity during hyperglycemic clamp declined by ∼30% and ∼55% (both P < 0.05), respectively, during the first and second hyperglycemic clamp steps. Insulin secretion/insulin resistance (disposition) index declined by 60% (second clamp step) and by 62% following arginine (both P < 0.005) following 72-h glucose infusion. The effect of 72-h glucose infusion on insulin secretion and insulin sensitivity was similar in subjects with and without FH of T2DM. Following 72 h of physiologic hyperglycemia, metabolic clearance rate of insulin was markedly reduced (P < 0.01). These results demonstrate that sustained physiologic hyperglycemia for 72 h 1) increases absolute insulin secretion but impairs β-cell function, 2) causes insulin resistance, and 3) reduces metabolic clearance rate of insulin.
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Affiliation(s)
- Aurora Merovci
- Division of Diabetes, Department of Medicine, University of Texas Health Science Center, San Antonio, TX
| | - Devjit Tripathy
- Division of Diabetes, Department of Medicine, University of Texas Health Science Center, San Antonio, TX
- Audie L. Murphy VA Hospital, South Texas Veterans Heath Care System, Foundation for Advancing Veterans' Health Research, San Antonio, TX
| | - Xi Chen
- Division of Diabetes, Department of Medicine, University of Texas Health Science Center, San Antonio, TX
| | - Ivan Valdez
- Division of Diabetes, Department of Medicine, University of Texas Health Science Center, San Antonio, TX
| | - Muhammad Abdul-Ghani
- Division of Diabetes, Department of Medicine, University of Texas Health Science Center, San Antonio, TX
| | - Carolina Solis-Herrera
- Division of Diabetes, Department of Medicine, University of Texas Health Science Center, San Antonio, TX
| | - Amalia Gastaldelli
- Division of Diabetes, Department of Medicine, University of Texas Health Science Center, San Antonio, TX
| | - Ralph A DeFronzo
- Division of Diabetes, Department of Medicine, University of Texas Health Science Center, San Antonio, TX
- Audie L. Murphy VA Hospital, South Texas Veterans Heath Care System, Foundation for Advancing Veterans' Health Research, San Antonio, TX
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Sheikh MA, Emerald BS, Ansari SA. Stem cell fate determination through protein O-GlcNAcylation. J Biol Chem 2021; 296:100035. [PMID: 33154167 PMCID: PMC7948975 DOI: 10.1074/jbc.rev120.014915] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Revised: 11/05/2020] [Accepted: 11/05/2020] [Indexed: 12/13/2022] Open
Abstract
Embryonic and adult stem cells possess the capability of self-renewal and lineage-specific differentiation. The intricate balance between self-renewal and differentiation is governed by developmental signals and cell-type-specific gene regulatory mechanisms. A perturbed intra/extracellular environment during lineage specification could affect stem cell fate decisions resulting in pathology. Growing evidence demonstrates that metabolic pathways govern epigenetic regulation of gene expression during stem cell fate commitment through the utilization of metabolic intermediates or end products of metabolic pathways as substrates for enzymatic histone/DNA modifications. UDP-GlcNAc is one such metabolite that acts as a substrate for enzymatic mono-glycosylation of various nuclear, cytosolic, and mitochondrial proteins on serine/threonine amino acid residues, a process termed protein O-GlcNAcylation. The levels of GlcNAc inside the cells depend on the nutrient availability, especially glucose. Thus, this metabolic sensor could modulate gene expression through O-GlcNAc modification of histones or other proteins in response to metabolic fluctuations. Herein, we review evidence demonstrating how stem cells couple metabolic inputs to gene regulatory pathways through O-GlcNAc-mediated epigenetic/transcriptional regulatory mechanisms to govern self-renewal and lineage-specific differentiation programs. This review will serve as a primer for researchers seeking to better understand how O-GlcNAc influences stemness and may catalyze the discovery of new stem-cell-based therapeutic approaches.
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Affiliation(s)
- Muhammad Abid Sheikh
- Department of Biochemistry, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, Abu Dhabi, UAE
| | - Bright Starling Emerald
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, Abu Dhabi, UAE; Zayed Center for Health Sciences, United Arab Emirates University, Al Ain, Abu Dhabi, UAE
| | - Suraiya Anjum Ansari
- Department of Biochemistry, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, Abu Dhabi, UAE; Zayed Center for Health Sciences, United Arab Emirates University, Al Ain, Abu Dhabi, UAE.
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Cao H, Hu Y, Zhu X, Yao N, Gu J, Wang Y, Zhu W. O-GlcNAc transferase affects the signal transduction of β1 adrenoceptor in adult rat cardiomyocytes by increasing the O-GlcNAcylation of β1 adrenoceptor. Biochem Biophys Res Commun 2020; 528:71-77. [PMID: 32471715 DOI: 10.1016/j.bbrc.2020.05.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 05/01/2020] [Indexed: 12/11/2022]
Abstract
O-GlcNAcylation was first found by Torres and Hart in monocytes. It is a dynamic and reversible post-translational modification catalyzed by O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA). O-GlcNAcylation is increased in diabetic cardiomyopathy (DCM) patients and it has been reported that OGT plays an important role in the regulation of cardiac gene transcription, cell cycle and calcium homeostasis. The purpose of this study is to investigate the effects of OGT on signal transduction and function of β1-adrenoceptor (β1AR) in adult rat cardiomyocytes. We found that after overexpressing OGT by adenovirus vector in adult rat cardiomyocytes, cAMP formation and phosphorylation of phospholamban (PLB) at Ser16 (p16-PLB) were decreased under isoprenaline (ISO) stimulation. Over expression of OGT increased the intracellular [Ca2+]i and deteriorated the death of cardiomyocytes induced by prolonged stimulation with ISO. β1-adrenoceptor was overexpressed using a plasmid vector and then co-immunoprecipitation (co-IP) followed by Western blot was employed to define the O-GlcNAcylation of β1-adrenoceptor. The results showed that O-GlcNAcylation of β1-adrenoceptor was increased in OGT overexpressed cells, and there was no significant change in the formation of cAMP and phosphorylation of PLB after β1-adrenoceptor was blocked by CGP20712A. Given that OGT affects the signal transduction of β1-adrenoceptor in adult rat cardiomyocytes by increasing the O-GlcNAcylation of β1-adrenoceptor, the mechanism revealed in this study indicates that OGT and β1AR may be therapeutic targets in patients undergoing diabetic cardiomyopathy.
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Affiliation(s)
- Hong Cao
- Cardiovascular laboratory, Department of Pharmacology, School of Pharmacy, Nantong University, Nantong, 226001, China.
| | - Ying Hu
- Cardiovascular laboratory, Department of Pharmacology, School of Pharmacy, Nantong University, Nantong, 226001, China
| | - Xiaofang Zhu
- Cardiovascular laboratory, Department of Pharmacology, School of Pharmacy, Nantong University, Nantong, 226001, China
| | - Na Yao
- Cardiovascular laboratory, Department of Pharmacology, School of Pharmacy, Nantong University, Nantong, 226001, China
| | - Jiaona Gu
- Cardiovascular laboratory, Department of Pharmacology, School of Pharmacy, Nantong University, Nantong, 226001, China
| | - Yuhang Wang
- Cardiovascular laboratory, Department of Pharmacology, School of Pharmacy, Nantong University, Nantong, 226001, China
| | - Weizhong Zhu
- Cardiovascular laboratory, Department of Pharmacology, School of Pharmacy, Nantong University, Nantong, 226001, China
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Chen Y, Zhao X, Wu H. Metabolic Stress and Cardiovascular Disease in Diabetes Mellitus: The Role of Protein O-GlcNAc Modification. Arterioscler Thromb Vasc Biol 2019; 39:1911-1924. [PMID: 31462094 DOI: 10.1161/atvbaha.119.312192] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Mammalian cells metabolize glucose primarily for energy production, biomass synthesis, and posttranslational glycosylation; and maintaining glucose metabolic homeostasis is essential for normal physiology of cells. Impaired glucose homeostasis leads to hyperglycemia, a hallmark of diabetes mellitus. Chronically increased glucose in diabetes mellitus promotes pathological changes accompanied by impaired cellular function and tissue damage, which facilitates the development of cardiovascular complications, the major cause of morbidity and mortality of patients with diabetes mellitus. Emerging roles of glucose metabolism via the hexosamine biosynthesis pathway (HBP) and increased protein modification via O-linked β-N-acetylglucosamine (O-GlcNAcylation) have been demonstrated in diabetes mellitus and implicated in the development of diabetic cardiovascular complications. This review will discuss the biological outcomes of the glucose metabolism via the hexosamine biogenesis pathway and protein O-GlcNAcylation in regulating cellular homeostasis, and highlight the regulations and contributions of elevated O-GlcNAcylation to the pathogenesis of diabetic cardiovascular disease.
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Affiliation(s)
- Yabing Chen
- From the Department of Pathology (Y.C.), University of Alabama at Birmingham.,Birmingham Veterans Affairs Medical Center, Research Division (Y.C.), Birmingham, Alabama
| | - Xinyang Zhao
- Biochemistry (X.Z.), University of Alabama at Birmingham
| | - Hui Wu
- Pediatric Dentistry (H.W.), University of Alabama at Birmingham
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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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Shan S, Chatterjee A, Qiu Y, Hammes HP, Wieland T, Feng Y. O-GlcNAcylation of FoxO1 mediates nucleoside diphosphate kinase B deficiency induced endothelial damage. Sci Rep 2018; 8:10581. [PMID: 30002415 PMCID: PMC6043576 DOI: 10.1038/s41598-018-28892-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 06/26/2018] [Indexed: 12/20/2022] Open
Abstract
Nucleoside diphosphate kinase B (NDPK-B) acts as a protective factor in the retinal vasculature. NDPK-B deficiency leads to retinal vasoregression mimicking diabetic retinopathy (DR). Angiopoetin 2 (Ang-2), an initiator of retinal vasoregression in DR, is upregulated in NDPK-B deficient retinas and in NDPK-B depleted endothelial cells (ECs) in vitro. We therefore investigated the importance of Ang-2 in NDPK-B deficient retinas and characterized the mechanisms of Ang-2 upregulation upon NDPK-B depletion in cultured ECs. The crucial role of retinal Ang-2 in the initiation of vasoregression was verified by crossing NDPK-B deficient with Ang-2 haplodeficient mice. On the molecular level, FoxO1, a transcription factor regulating Ang-2, was upregulated in NDPK-B depleted ECs. Knockdown of FoxO1 abolished the elevation of Ang-2 induced by NDPK-B depletion. Furthermore O-GlcNAcylated FoxO1 was found preferentially in the nucleus. An increased O-GlcNAcylation of FoxO1 was revealed upon NDPK-B depletion. In accordance, the inhibition of protein O-GlcNAcylation normalized NDPK-B depletion induced Ang-2 upregulation. In summary, we demonstrated that the upregulation of Ang-2 upon NDPK-B deficiency is driven by O-GlcNAcylation of FoxO1. Our data provide evidence for a central role of protein O-GlcNAcylation in NDPK-B associated vascular damage and point to the hexosamine pathway as an important target in retinal vasoregression.
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Affiliation(s)
- Shenliang Shan
- Experimental Pharmacology Mannheim (EPM), European Center of Angioscience, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Anupriya Chatterjee
- Experimental Pharmacology Mannheim (EPM), European Center of Angioscience, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Yi Qiu
- Experimental Pharmacology Mannheim (EPM), European Center of Angioscience, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Hans-Peter Hammes
- 5th Medical Clinic, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Thomas Wieland
- Experimental Pharmacology Mannheim (EPM), European Center of Angioscience, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Mannheim, Germany
| | - Yuxi Feng
- Experimental Pharmacology Mannheim (EPM), European Center of Angioscience, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.
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15
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The Nutrient-Sensing Hexosamine Biosynthetic Pathway as the Hub of Cancer Metabolic Rewiring. Cells 2018; 7:cells7060053. [PMID: 29865240 PMCID: PMC6025041 DOI: 10.3390/cells7060053] [Citation(s) in RCA: 94] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 05/29/2018] [Accepted: 05/31/2018] [Indexed: 12/12/2022] Open
Abstract
Alterations in glucose and glutamine utilizing pathways and in fatty acid metabolism are currently considered the most significant and prevalent metabolic changes observed in almost all types of tumors. Glucose, glutamine and fatty acids are the substrates for the hexosamine biosynthetic pathway (HBP). This metabolic pathway generates the “sensing molecule” UDP-N-Acetylglucosamine (UDP-GlcNAc). UDP-GlcNAc is the substrate for the enzymes involved in protein N- and O-glycosylation, two important post-translational modifications (PTMs) identified in several proteins localized in the extracellular space, on the cell membrane and in the cytoplasm, nucleus and mitochondria. Since protein glycosylation controls several key aspects of cell physiology, aberrant protein glycosylation has been associated with different human diseases, including cancer. Here we review recent evidence indicating the tight association between the HBP flux and cell metabolism, with particular emphasis on the post-transcriptional and transcriptional mechanisms regulated by the HBP that may cause the metabolic rewiring observed in cancer. We describe the implications of both protein O- and N-glycosylation in cancer cell metabolism and bioenergetics; focusing our attention on the effect of these PTMs on nutrient transport and on the transcriptional regulation and function of cancer-specific metabolic pathways.
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16
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Ducheix S, Magré J, Cariou B, Prieur X. Chronic O-GlcNAcylation and Diabetic Cardiomyopathy: The Bitterness of Glucose. Front Endocrinol (Lausanne) 2018; 9:642. [PMID: 30420836 PMCID: PMC6215811 DOI: 10.3389/fendo.2018.00642] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 10/09/2018] [Indexed: 12/16/2022] Open
Abstract
Type 2 diabetes (T2D) is a major risk factor for heart failure. Diabetic cardiomyopathy (DC) is characterized by diastolic dysfunction and left ventricular hypertrophy. Epidemiological data suggest that hyperglycaemia contributes to the development of DC. Several cellular pathways have been implicated in the deleterious effects of high glucose concentrations in the heart: oxidative stress, accumulation of advanced glycation end products (AGE), and chronic hexosamine biosynthetic pathway (HBP) activation. In the present review, we focus on the effect of chronic activation of the HBP on diabetic heart function. The HBP supplies N-acetylglucosamine moiety (O-GlcNAc) that is O-linked by O-GlcNAc transferase (OGT) to proteins on serine or threonine residues. This post-translational protein modification modulates the activity of the targeted proteins. In the heart, acute activation of the HBP in response to ischaemia-reperfusion injury appears to be protective. Conversely, chronic activation of the HBP in the diabetic heart affects Ca2+ handling, contractile properties, and mitochondrial function and promotes stress signaling, such as left ventricular hypertrophy and endoplasmic reticulum stress. Many studies have shown that O-GlcNAc impairs the function of key protein targets involved in these pathways, such as phospholamban, calmodulin kinase II, troponin I, and FOXO1. The data show that excessive O-GlcNAcylation is a major trigger of the glucotoxic events that affect heart function under chronic hyperglycaemia. Supporting this finding, pharmacological or genetic inhibition of the HBP in the diabetic heart improves heart function. In addition, the SGLT2 inhibitor dapagliflozin, a glucose lowering agent, has recently been shown to lower cardiac HBP in a lipodystophic T2D mice model and to concomitantly improve the diastolic dysfunction of these mice. Therefore, targeting cardiac-excessive O-GlcNAcylation or specific target proteins represents a potential therapeutic option to treat glucotoxicity in the diabetic heart.
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Affiliation(s)
- Simon Ducheix
- l'institut du thorax, INSERM, CNRS, UNIV Nantes, Nantes, France
| | - Jocelyne Magré
- l'institut du thorax, INSERM, CNRS, UNIV Nantes, Nantes, France
| | - Bertrand Cariou
- l'institut du thorax, INSERM, CNRS, UNIV Nantes, CHU Nantes, Nantes, France
| | - Xavier Prieur
- l'institut du thorax, INSERM, CNRS, UNIV Nantes, Nantes, France
- *Correspondence: Xavier Prieur
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17
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"Nutrient-sensing" and self-renewal: O-GlcNAc in a new role. J Bioenerg Biomembr 2017; 50:205-211. [PMID: 29204729 DOI: 10.1007/s10863-017-9735-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2017] [Accepted: 11/21/2017] [Indexed: 12/14/2022]
Abstract
Whether embryonic, hematopoietic or cancer stem cells, this metabolic reprogramming is dependent on the nutrient-status and bioenergetic pathways that is influenced by the micro-environmental niches like hypoxia. Thus, the microenvironment plays a vital role in determining the stem cell fate by inducing metabolic reprogramming. Under the influence of the microenvironment, like hypoxia, the stem cells have increased glucose and glutamine uptake which result in activation of hexosamine biosynthesis pathway (HBP) and increased O-GlcNAc Transferase (OGT). The current review is focused on understanding how HBP, a nutrient-sensing pathway (that leads to increased OGT activity) is instrumental in regulating self-renewal not only in embryonic and hematopoietic stem cells (ESC/HSC) but also in cancer stem cells.
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18
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Hernández-Sánchez F, Guzmán-Beltrán S, Herrera MT, Gonzalez Y, Salgado M, Fabian G, Torres M. High glucose induces O-GlcNAc glycosylation of the vitamin D receptor (VDR) in THP1 cells and in human macrophages derived from monocytes. Cell Biol Int 2017; 41:1065-1074. [PMID: 28710799 DOI: 10.1002/cbin.10827] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2017] [Accepted: 07/13/2017] [Indexed: 01/13/2023]
Abstract
Chronic hyperglycemia increases the carbon flux through the hexosamine pathway, allowing the accumulation of UDP-GlcNAc. UDP-GlcNAc is the sugar donor for the enzyme-mediated protein glycosylation event known as OGlcNAcylation. This posttranslational modification targets several transcription factors implicated in glucose toxicity, insulin resistance, and diabetes. Vitamin D plays an important role in glucose homeostasis and insulin secretion through transcriptional mechanisms mediated by its receptor (VDR). Vitamin D deficiency has been associated with higher susceptibility to bacterial diseases in diabetic patients. However, it has not been explored whether VDR is subject to OGlcNAcylation or whether high glucose affects its transcriptional or biological activities. The aim of this study was to evaluate the effect of hyperglycemia on VDR OGlcNAcylation and its effects on vitamin D-mediated transcription. We predicted potential OGlcNAcylation sites using free software. Our results showed that hyperglycemia (30 mM) induces the OGlcNAcylation of VDR in THP1 cells and in human macrophages derived from monocytes (MDM). This condition did not hamper the vitamin D-dependent activation of LL-37 gene expression, and even did not impair the macrophage bactericidal activity. Our study provides new insight into vitamin D receptor posttranslational modification that may have relevance on the physiological responses of long-term hyperglycemia.
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Affiliation(s)
- Fernando Hernández-Sánchez
- Departamento de Investigación en Microbiología, Instituto Nacional de Enfermedades Respiratorias, Calzada de Tlalpan 4502, Sección XVI, México City, Mexico, 1408
| | - Silvia Guzmán-Beltrán
- Departamento de Investigación en Microbiología, Instituto Nacional de Enfermedades Respiratorias, Calzada de Tlalpan 4502, Sección XVI, México City, Mexico, 1408
| | - María Teresa Herrera
- Departamento de Investigación en Microbiología, Instituto Nacional de Enfermedades Respiratorias, Calzada de Tlalpan 4502, Sección XVI, México City, Mexico, 1408
| | - Yolanda Gonzalez
- Departamento de Investigación en Microbiología, Instituto Nacional de Enfermedades Respiratorias, Calzada de Tlalpan 4502, Sección XVI, México City, Mexico, 1408
| | - Manuel Salgado
- Departamento de Investigación en Microbiología, Instituto Nacional de Enfermedades Respiratorias, Calzada de Tlalpan 4502, Sección XVI, México City, Mexico, 1408
| | - Guadalupe Fabian
- Departamento de Investigación en Microbiología, Instituto Nacional de Enfermedades Respiratorias, Calzada de Tlalpan 4502, Sección XVI, México City, Mexico, 1408
| | - Martha Torres
- Departamento de Investigación en Microbiología, Instituto Nacional de Enfermedades Respiratorias, Calzada de Tlalpan 4502, Sección XVI, México City, Mexico, 1408
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19
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Joubert M, Jagu B, Montaigne D, Marechal X, Tesse A, Ayer A, Dollet L, Le May C, Toumaniantz G, Manrique A, Charpentier F, Staels B, Magré J, Cariou B, Prieur X. The Sodium-Glucose Cotransporter 2 Inhibitor Dapagliflozin Prevents Cardiomyopathy in a Diabetic Lipodystrophic Mouse Model. Diabetes 2017; 66:1030-1040. [PMID: 28052965 DOI: 10.2337/db16-0733] [Citation(s) in RCA: 108] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 12/16/2016] [Indexed: 12/18/2022]
Abstract
Type 2 diabetes mellitus (T2DM) is a well-recognized independent risk factor for heart failure. T2DM is associated with altered cardiac energy metabolism, leading to ectopic lipid accumulation and glucose overload, the exact contribution of these two parameters remaining unclear. To provide new insight into the mechanism driving the development of diabetic cardiomyopathy, we studied a unique model of T2DM: lipodystrophic Bscl2-/- (seipin knockout [SKO]) mice. Echocardiography and cardiac magnetic resonance imaging revealed hypertrophic cardiomyopathy with left ventricular dysfunction in SKO mice, and these two abnormalities were strongly correlated with hyperglycemia. Surprisingly, neither intramyocardial lipid accumulation nor lipotoxic hallmarks were detected in SKO mice. [18F]Fludeoxyglucose positron emission tomography showed increased myocardial glucose uptake. Consistently, the O-GlcNAcylated protein levels were markedly increased in an SKO heart, suggesting a glucose overload. To test this hypothesis, we treated SKO mice with the hypoglycemic sodium-glucose cotransporter 2 (SGLT2) inhibitor dapagliflozin and the insulin sensitizer pioglitazone. Both treatments reduced the O-GlcNAcylated protein levels in SKO mice, and dapagliflozin successfully prevented the development of hypertrophic cardiomyopathy. Our data demonstrate that glucotoxicity by itself can trigger cardiac dysfunction and that a glucose-lowering agent can correct it. This result will contribute to better understanding of the potential cardiovascular benefits of SGLT2 inhibitors.
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Affiliation(s)
- Michael Joubert
- L'Institut du Thorax, INSERM, CNRS, Université de Nantes, Nantes, France
- Endocrinologie, CHU Caen, Caen, France
- EA 4650, UNICAEN, GIP Cyceron, Caen, France
| | - Benoît Jagu
- L'Institut du Thorax, INSERM, CNRS, Université de Nantes, Nantes, France
| | - David Montaigne
- Universite Lille, INSERM, CHU Lille, Institut Pasteur de Lille, U1011-European Genomic Institute for Diabetes, Lille, France
| | - Xavier Marechal
- Universite Lille, INSERM, CHU Lille, Institut Pasteur de Lille, U1011-European Genomic Institute for Diabetes, Lille, France
| | - Angela Tesse
- L'Institut du Thorax, INSERM, CNRS, Université de Nantes, Nantes, France
| | - Audrey Ayer
- L'Institut du Thorax, INSERM, CNRS, Université de Nantes, Nantes, France
| | - Lucile Dollet
- L'Institut du Thorax, INSERM, CNRS, Université de Nantes, Nantes, France
| | - Cédric Le May
- L'Institut du Thorax, INSERM, CNRS, Université de Nantes, Nantes, France
| | - Gilles Toumaniantz
- L'Institut du Thorax, INSERM, CNRS, Université de Nantes, Nantes, France
| | | | | | - Bart Staels
- Universite Lille, INSERM, CHU Lille, Institut Pasteur de Lille, U1011-European Genomic Institute for Diabetes, Lille, France
| | - Jocelyne Magré
- L'Institut du Thorax, INSERM, CNRS, Université de Nantes, Nantes, France
| | - Bertrand Cariou
- L'Institut du Thorax, INSERM, CNRS, Université de Nantes, CHU Nantes, Nantes, France
| | - Xavier Prieur
- L'Institut du Thorax, INSERM, CNRS, Université de Nantes, Nantes, France
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20
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Misra J, Kim DK, Jung YS, Kim HB, Kim YH, Yoo EK, Kim BG, Kim S, Lee IK, Harris RA, Kim JS, Lee CH, Cho JW, Choi HS. O-GlcNAcylation of Orphan Nuclear Receptor Estrogen-Related Receptor γ Promotes Hepatic Gluconeogenesis. Diabetes 2016; 65:2835-48. [PMID: 27335230 DOI: 10.2337/db15-1523] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 06/15/2016] [Indexed: 11/13/2022]
Abstract
Estrogen-related receptor γ (ERRγ) is a major positive regulator of hepatic gluconeogenesis. Its transcriptional activity is suppressed by phosphorylation signaled by insulin in the fed state, but whether posttranslational modification alters its gluconeogenic activity in the fasted state is not known. Metabolically active hepatocytes direct a small amount of glucose into the hexosamine biosynthetic pathway, leading to protein O-GlcNAcylation. In this study, we demonstrate that ERRγ is O-GlcNAcylated by O-GlcNAc transferase in the fasted state. This stabilizes the protein by inhibiting proteasome-mediated protein degradation, increasing ERRγ recruitment to gluconeogenic gene promoters. Mass spectrometry identifies two serine residues (S317, S319) present in the ERRγ ligand-binding domain that are O-GlcNAcylated. Mutation of these residues destabilizes ERRγ protein and blocks the ability of ERRγ to induce gluconeogenesis in vivo. The impact of this pathway on gluconeogenesis in vivo was confirmed by the observation that decreasing the amount of O-GlcNAcylated ERRγ by overexpressing the deglycosylating enzyme O-GlcNAcase decreases ERRγ-dependent glucose production in fasted mice. We conclude that O-GlcNAcylation of ERRγ serves as a major signal to promote hepatic gluconeogenesis.
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Affiliation(s)
- Jagannath Misra
- National Creative Research Initiatives Center for Nuclear Receptor Signals and Hormone Research Center, School of Biological Sciences and Technology, Chonnam National University, Gwangju, Republic of Korea
| | - Don-Kyu Kim
- National Creative Research Initiatives Center for Nuclear Receptor Signals and Hormone Research Center, School of Biological Sciences and Technology, Chonnam National University, Gwangju, Republic of Korea
| | - Yoon Seok Jung
- National Creative Research Initiatives Center for Nuclear Receptor Signals and Hormone Research Center, School of Biological Sciences and Technology, Chonnam National University, Gwangju, Republic of Korea
| | - Han Byeol Kim
- Department of Integrated OMICS for Biomedical Science, Yonsei University, Seoul, Republic of Korea
| | - Yong-Hoon Kim
- Korea Research Institute of Bioscience and Biotechnology, Daejeon, Republic of Korea
| | - Eun-Kyung Yoo
- Department of Internal Medicine, Kyungpook National University School of Medicine, Deagu, Republic of Korea
| | - Byung Gyu Kim
- Leading-edge Research Center for Drug Discovery and Development and Metabolic Disease, Kyungpook National University, Daegu, Korea
| | - Sunghoon Kim
- Medicinal Bioconvergence Research Center Department of Molecular Medicine and Biopharmaceutical Sciences Graduate School of Convergence Science and Technology College of Pharmacy, Seoul National University, Seoul, Korea
| | - In-Kyu Lee
- Department of Internal Medicine, Kyungpook National University School of Medicine, Deagu, Republic of Korea
| | - Robert A Harris
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine and the Roudebush VA Medical Center, Indianapolis, IN
| | - Jeong-Sun Kim
- Department of Chemistry and Institute of Basic Sciences, Chonnam National University, Gwangju, Republic of Korea
| | - Chul-Ho Lee
- Korea Research Institute of Bioscience and Biotechnology, Daejeon, Republic of Korea
| | - Jin Won Cho
- Department of Integrated OMICS for Biomedical Science, Yonsei University, Seoul, Republic of Korea
| | - Hueng-Sik Choi
- National Creative Research Initiatives Center for Nuclear Receptor Signals and Hormone Research Center, School of Biological Sciences and Technology, Chonnam National University, Gwangju, Republic of Korea
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21
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Zheng H, Wu J, Jin Z, Yan LJ. Protein Modifications as Manifestations of Hyperglycemic Glucotoxicity in Diabetes and Its Complications. BIOCHEMISTRY INSIGHTS 2016; 9:1-9. [PMID: 27042090 PMCID: PMC4807886 DOI: 10.4137/bci.s36141] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 02/25/2016] [Accepted: 02/27/2016] [Indexed: 02/07/2023]
Abstract
Diabetes and its complications are hyperglycemic toxicity diseases. Many metabolic pathways in this array of diseases become aberrant, which is accompanied with a variety of posttranslational protein modifications that in turn reflect diabetic glucotoxicity. In this review, we summarize some of the most widely studied protein modifications in diabetes and its complications. These modifications include glycation, carbonylation, nitration, cysteine S-nitrosylation, acetylation, sumoylation, ADP-ribosylation, O-GlcNAcylation, and succination. All these posttranslational modifications can be significantly attributed to oxidative stress and/or carbon stress induced by diabetic redox imbalance that is driven by activation of pathways, such as the polyol pathway and the ADP-ribosylation pathway. Exploring the nature of these modifications should facilitate our understanding of the pathological mechanisms of diabetes and its associated complications.
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Affiliation(s)
- Hong Zheng
- Department of Pharmaceutical Sciences, UNT System College of Pharmacy, UNT Health Science Center, Fort Worth, TX, USA.; Department of Basic Theory of Traditional Chinese Medicine, College of Basic Medicine, Shandong University of Traditional Chinese Medicine, Jinan, Shandong, China
| | - Jinzi Wu
- Department of Pharmaceutical Sciences, UNT System College of Pharmacy, UNT Health Science Center, Fort Worth, TX, USA
| | - Zhen Jin
- Department of Pharmaceutical Sciences, UNT System College of Pharmacy, UNT Health Science Center, Fort Worth, TX, USA
| | - Liang-Jun Yan
- Department of Pharmaceutical Sciences, UNT System College of Pharmacy, UNT Health Science Center, Fort Worth, TX, USA
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22
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Luo X, Wu J, Jing S, Yan LJ. Hyperglycemic Stress and Carbon Stress in Diabetic Glucotoxicity. Aging Dis 2016; 7:90-110. [PMID: 26816666 DOI: 10.14336/ad.2015.0702] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2015] [Accepted: 07/02/2015] [Indexed: 12/16/2022] Open
Abstract
Diabetes and its complications are caused by chronic glucotoxicity driven by persistent hyperglycemia. In this article, we review the mechanisms of diabetic glucotoxicity by focusing mainly on hyperglycemic stress and carbon stress. Mechanisms of hyperglycemic stress include reductive stress or pseudohypoxic stress caused by redox imbalance between NADH and NAD(+) driven by activation of both the polyol pathway and poly ADP ribose polymerase; the hexosamine pathway; the advanced glycation end products pathway; the protein kinase C activation pathway; and the enediol formation pathway. Mechanisms of carbon stress include excess production of acetyl-CoA that can over-acetylate a proteome and excess production of fumarate that can over-succinate a proteome; both of which can increase glucotoxicity in diabetes. For hyperglycemia stress, we also discuss the possible role of mitochondrial complex I in diabetes as this complex, in charge of NAD(+) regeneration, can make more reactive oxygen species (ROS) in the presence of excess NADH. For carbon stress, we also discuss the role of sirtuins in diabetes as they are deacetylases that can reverse protein acetylation thereby attenuating diabetic glucotoxicity and improving glucose metabolism. It is our belief that targeting some of the stress pathways discussed in this article may provide new therapeutic strategies for treatment of diabetes and its complications.
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Affiliation(s)
- Xiaoting Luo
- 1 Department of Pharmaceutical Sciences, UNT System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX 76107, USA; 2 Department of Biochemistry and Molecular Biology, Gannan Medical University, Ganzhou, Jiangxi province, China, 341000
| | - Jinzi Wu
- 1 Department of Pharmaceutical Sciences, UNT System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX 76107, USA
| | - Siqun Jing
- 1 Department of Pharmaceutical Sciences, UNT System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX 76107, USA; 3 College of Life Sciences and Technology, Xinjiang University, Urumqi, Xinjiang, China, 830046
| | - Liang-Jun Yan
- 1 Department of Pharmaceutical Sciences, UNT System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX 76107, USA
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23
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Fardini Y, Perez-Cervera Y, Camoin L, Pagesy P, Lefebvre T, Issad T. Regulatory O-GlcNAcylation sites on FoxO1 are yet to be identified. Biochem Biophys Res Commun 2015; 462:151-8. [PMID: 25944660 DOI: 10.1016/j.bbrc.2015.04.114] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Accepted: 04/23/2015] [Indexed: 01/25/2023]
Abstract
O-GlcNAcylation is a reversible post-translational modification that regulates cytosolic and nuclear proteins. We and others previously demonstrated that FoxO1 is O-GlcNAcylated in different cell types, resulting in an increase in its transcriptional activity. Four O-GlcNAcylation sites were identified in human FOXO1 but directed mutagenesis of each site individually had modest (T317) or no effect (S550, T648, S654) on its O-GlcNAcylation status and transcriptional activity. Moreover, the consequences of mutating all four sites had not been investigated. In the present work, we mutated these sites in the mouse Foxo1 and found that mutation of all four sites did not decrease Foxo1 O-GlcNAcylation status and transcriptional activity, and would even tend to increase them. In an attempt to identify other O-GlcNAcylation sites, we immunoprecipitated wild-type O-GlcNAcylated Foxo1 and analysed the tryptic digest peptides by mass spectrometry using High-energy Collisional Dissociation. We identified T646 as a new O-GlcNAcylation site on Foxo1. However, site directed mutagenesis of this site individually or together with all four previously identified residues did not impair Foxo1 O-GlcNAcylation and transcriptional activity. These results suggest that residues important for the control of Foxo1 activity by O-GlcNAcylation still remain to be identified.
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Affiliation(s)
- Yann Fardini
- INSERM, U1016, Institut Cochin, Paris, France; CNRS, UMR8104, Paris, France; Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Yobana Perez-Cervera
- Structural and Functional Glycobiology Unit, Lille 1 University, CNRS (UMR 8576), IFR 117, Villeneuve d'Ascq, France; Facultad de Odontología, Universidad Autónoma Benito Juárez de Oaxaca, Oaxaca, Mexico
| | - Luc Camoin
- INSERM, U1068, CRCM, Marseille Protéomique IBiSA, Marseille, F-13009, France; Institut Paoli-Calmettes Team, Cell Polarity, Cell Signaling and Cancer, Marseille, F-13009, France; Aix-Marseille Université, F-13284, Marseille, France; CNRS, UMR7258, CRCM, Marseille, F-13009, France
| | - Patrick Pagesy
- INSERM, U1016, Institut Cochin, Paris, France; CNRS, UMR8104, Paris, France; Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Tony Lefebvre
- Structural and Functional Glycobiology Unit, Lille 1 University, CNRS (UMR 8576), IFR 117, Villeneuve d'Ascq, France
| | - Tarik Issad
- INSERM, U1016, Institut Cochin, Paris, France; CNRS, UMR8104, Paris, France; Université Paris Descartes, Sorbonne Paris Cité, Paris, France.
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24
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Peternelj TT, Marsh SA, Morais C, Small DM, Dalbo VJ, Tucker PS, Coombes JS. O-GlcNAc protein modification in C2C12 myoblasts exposed to oxidative stress indicates parallels with endogenous antioxidant defense. Biochem Cell Biol 2014; 93:63-73. [PMID: 25453190 DOI: 10.1139/bcb-2014-0106] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
A growing body of evidence demonstrates the involvement of protein modification with O-linked β-N-acetylglucosamine (O-GlcNAc) in the stress response and its beneficial effects on cell survival. Here we investigated protein O-GlcNAcylation in skeletal muscle cells exposed to oxidative stress and the crosstalk with endogenous antioxidant system. The study focused on antioxidant enzymes superoxide dismutase 2 (SOD2), catalase (CAT), and glutathione peroxidase 1 (GPX1), and transcriptional regulators proliferator-activated receptor gamma coactivator 1-α (PGC-1α) and forkhead box protein O1 (FOXO1), which play important roles in oxidative stress response and are known to be O-GlcNAc-modified. C2C12 myoblasts were subjected to 24 h incubation with different reagents, including hydrogen peroxide, diethyl maleate, high glucose, and glucosamine, and the inhibitors of O-GlcNAc cycling enzymes. Surprisingly, O-GlcNAc levels were significantly increased only with glucosamine, whilst other treatments showed no effect. Significant changes at the mRNA level were observed with concomitant upregulation of the genes for O-GlcNAc enzymes and stress-related proteins with oxidizing agents and downregulation of these genes with agents promoting O-GlcNAcylation. Our findings suggest a role of O-GlcNAc in the stress response and indicate an inhibitory mechanism controlling O-GlcNAc levels in the muscle cells. This could represent an important homeostatic regulation of the cellular defense system.
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Affiliation(s)
- Tina Tinkara Peternelj
- a Antioxidant Research Group, School of Human Movement Studies, The University of Queensland, Brisbane, QLD, Australia
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Guo S. Insulin signaling, resistance, and the metabolic syndrome: insights from mouse models into disease mechanisms. J Endocrinol 2014; 220:T1-T23. [PMID: 24281010 PMCID: PMC4087161 DOI: 10.1530/joe-13-0327] [Citation(s) in RCA: 329] [Impact Index Per Article: 32.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Insulin resistance is a major underlying mechanism responsible for the 'metabolic syndrome', which is also known as insulin resistance syndrome. The incidence of the metabolic syndrome is increasing at an alarming rate, becoming a major public and clinical problem worldwide. The metabolic syndrome is represented by a group of interrelated disorders, including obesity, hyperglycemia, hyperlipidemia, and hypertension. It is also a significant risk factor for cardiovascular disease and increased morbidity and mortality. Animal studies have demonstrated that insulin and its signaling cascade normally control cell growth, metabolism, and survival through the activation of MAPKs and activation of phosphatidylinositide-3-kinase (PI3K), in which the activation of PI3K associated with insulin receptor substrate 1 (IRS1) and IRS2 and subsequent Akt→Foxo1 phosphorylation cascade has a central role in the control of nutrient homeostasis and organ survival. The inactivation of Akt and activation of Foxo1, through the suppression IRS1 and IRS2 in different organs following hyperinsulinemia, metabolic inflammation, and overnutrition, may act as the underlying mechanisms for the metabolic syndrome in humans. Targeting the IRS→Akt→Foxo1 signaling cascade will probably provide a strategy for therapeutic intervention in the treatment of type 2 diabetes and its complications. This review discusses the basis of insulin signaling, insulin resistance in different mouse models, and how a deficiency of insulin signaling components in different organs contributes to the features of the metabolic syndrome. Emphasis is placed on the role of IRS1, IRS2, and associated signaling pathways that are coupled to Akt and the forkhead/winged helix transcription factor Foxo1.
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Affiliation(s)
- Shaodong Guo
- Division of Molecular Cardiology, Department of Medicine, College of Medicine, Texas A&M University Health Science Center, Scott & White, Central Texas Veterans Health Care System, 1901 South 1st Street, Bldg. 205, Temple, Texas 76504, USA
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Baudoin L, Issad T. O-GlcNAcylation and Inflammation: A Vast Territory to Explore. Front Endocrinol (Lausanne) 2014; 5:235. [PMID: 25620956 PMCID: PMC4288382 DOI: 10.3389/fendo.2014.00235] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2014] [Accepted: 12/18/2014] [Indexed: 01/04/2023] Open
Abstract
O-GlcNAcylation is a reversible post-translational modification that regulates the activities of cytosolic and nuclear proteins according to glucose availability. This modification appears to participate in several hyperglycemia-associated complications. An important feature of metabolic diseases such as diabetes and obesity is the presence of a low-grade chronic inflammation that causes numerous complications. Hyperglycemia associated with the metabolic syndrome is known to promote inflammatory processes through different mechanisms including oxidative stress and abnormally elevated protein O-GlcNAcylation. However, the role of O-GlcNAcylation on inflammation remains contradictory. O-GlcNAcylation associated with hyperglycemia has been shown to increase nuclear factor κB (NFκB) transcriptional activity through different mechanisms. This could contribute in inflammation-associated diabetic complications. However, in other conditions such as acute vascular injury, O-linked N-acetyl glucosamine (O-GlcNAc) also exerts anti-inflammatory effects via inhibition of the NFκB pathway, suggesting a complex regulation of inflammation by O-GlcNAc. Moreover, whereas macrophages and monocytes exposed to high glucose for a long-term period developed a pro-inflammatory phenotype, the impact of O-GlcNAcylation in these cells remains unclear. A future challenge will be to clearly establish the role of O-GlcNAcylation in pro- and anti-inflammatory functions in macrophages.
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Affiliation(s)
- Léa Baudoin
- UMR8104, CNRS, Institut Cochin, Université Paris Descartes, Paris, France
- U1016, INSERM, Paris, France
| | - Tarik Issad
- UMR8104, CNRS, Institut Cochin, Université Paris Descartes, Paris, France
- U1016, INSERM, Paris, France
- *Correspondence: Tarik Issad, Department of Endocrinology, Metabolism and Diabetes, Institute Cochin, 22 rue Méchain, Paris 75014, France e-mail:
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Fardini Y, Masson E, Boudah O, Ben Jouira R, Cosson C, Pierre-Eugene C, Kuo MS, Issad T. O-GlcNAcylation of FoxO1 in pancreatic β cells promotes Akt inhibition through an IGFBP1-mediated autocrine mechanism. FASEB J 2013; 28:1010-21. [PMID: 24174424 DOI: 10.1096/fj.13-238378] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
O-GlcNAcylation on serine/threonine is a post-translational modification that controls the activity of nucleocytoplasmic proteins according to glucose availability. We previously showed that O-GlcNAcylation of FoxO1 in liver cells increases its transcriptional activity. In the present study, we evaluated the potential involvement of FoxO1 O-GlcNAcylation in the context of pancreatic β-cell glucotoxicity. FoxO1 was O-GlcNAcylated in INS-1 832/13 β cells and isolated rat pancreatic islets. O-GlcNAcylation of FoxO1 resulted in a 2-fold increase in its transcriptional activity toward a FoxO1 reporter gene and a 3-fold increase in the expression of the insulin-like growth factor-binding protein 1 (Igfbp1) gene at the mRNA level, resulting in IGFBP1 protein oversecretion by the cells. Of note, increased IGFBP1 in the culture medium inhibited the activity of the insulin-like growth factor 1 receptor (IGF1R)/phosphatidyl inositol 3 kinase (PI3K)/Akt pathway. We reveal in this report a novel mechanism by which O-GlcNAcylation inhibits Akt activity through an autocrine mechanism. However, although inhibition of IGFBP1 expression using siRNA restored the PI3 kinase/Akt pathway, it did not rescue INS-1 832/13 cells from high-glucose- or O-glcNAcylation-induced cell death. In contrast, FoxO1 down-regulation by siRNA led to 30 to 60% protection of INS-1 832/13 cells from death mediated by glucotoxic conditions. Therefore, whereas FoxO1 O-GlcNAcylation inhibits Akt through an IGFBP1-mediated autocrine pathway, the deleterious effects of FoxO1 O-GlcNAcylation on cell survival appeared to be independent of this pathway.
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Affiliation(s)
- Yann Fardini
- 1Department of Endocrinology, Metabolism, and Diabetes, Institut Cochin, 22 rue Méchain, 75014, Paris, France.
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Groves JA, Lee A, Yildirir G, Zachara NE. Dynamic O-GlcNAcylation and its roles in the cellular stress response and homeostasis. Cell Stress Chaperones 2013; 18:535-58. [PMID: 23620203 PMCID: PMC3745259 DOI: 10.1007/s12192-013-0426-y] [Citation(s) in RCA: 105] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Revised: 03/29/2013] [Accepted: 04/01/2013] [Indexed: 12/15/2022] Open
Abstract
O-linked N-acetyl-β-D-glucosamine (O-GlcNAc) is a ubiquitous and dynamic post-translational modification known to modify over 3,000 nuclear, cytoplasmic, and mitochondrial eukaryotic proteins. Addition of O-GlcNAc to proteins is catalyzed by the O-GlcNAc transferase and is removed by a neutral-N-acetyl-β-glucosaminidase (O-GlcNAcase). O-GlcNAc is thought to regulate proteins in a manner analogous to protein phosphorylation, and the cycling of this carbohydrate modification regulates many cellular functions such as the cellular stress response. Diverse forms of cellular stress and tissue injury result in enhanced O-GlcNAc modification, or O-GlcNAcylation, of numerous intracellular proteins. Stress-induced O-GlcNAcylation appears to promote cell/tissue survival by regulating a multitude of biological processes including: the phosphoinositide 3-kinase/Akt pathway, heat shock protein expression, calcium homeostasis, levels of reactive oxygen species, ER stress, protein stability, mitochondrial dynamics, and inflammation. Here, we will discuss the regulation of these processes by O-GlcNAc and the impact of such regulation on survival in models of ischemia reperfusion injury and trauma hemorrhage. We will also discuss the misregulation of O-GlcNAc in diseases commonly associated with the stress response, namely Alzheimer's and Parkinson's diseases. Finally, we will highlight recent advancements in the tools and technologies used to study the O-GlcNAc modification.
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Affiliation(s)
- Jennifer A. Groves
- The Department of Biological Chemistry, The Johns Hopkins University School of Medicine, 725 N. Wolfe St, Baltimore, MD 21205-2185 USA
| | - Albert Lee
- The Department of Biological Chemistry, The Johns Hopkins University School of Medicine, 725 N. Wolfe St, Baltimore, MD 21205-2185 USA
| | - Gokben Yildirir
- The Department of Biological Chemistry, The Johns Hopkins University School of Medicine, 725 N. Wolfe St, Baltimore, MD 21205-2185 USA
| | - Natasha E. Zachara
- The Department of Biological Chemistry, The Johns Hopkins University School of Medicine, 725 N. Wolfe St, Baltimore, MD 21205-2185 USA
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Kanwal S, Fardini Y, Pagesy P, N’Tumba-Byn T, Pierre-Eugène C, Masson E, Hampe C, Issad T. O-GlcNAcylation-inducing treatments inhibit estrogen receptor α expression and confer resistance to 4-OH-tamoxifen in human breast cancer-derived MCF-7 cells. PLoS One 2013; 8:e69150. [PMID: 23935944 PMCID: PMC3730543 DOI: 10.1371/journal.pone.0069150] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2013] [Accepted: 06/05/2013] [Indexed: 01/08/2023] Open
Abstract
O-GlcNAcylation (addition of N-acetyl-glucosamine on serine or threonine
residues) is a post-translational modification that regulates stability,
activity or localization of cytosolic and nuclear proteins. O-linked
N-acetylgluocosmaine transferase (OGT) uses UDP-GlcNAc, produced in the
hexosamine biosynthetic pathway to O-GlcNacylate proteins. Removal of O-GlcNAc
from proteins is catalyzed by the β-N-Acetylglucosaminidase (OGA). Recent
evidences suggest that O-GlcNAcylation may affect the growth of cancer cells.
However, the consequences of O-GlcNAcylation on anti-cancer therapy have not
been evaluated. In this work, we studied the effects of O-GlcNAcylation on
tamoxifen-induced cell death in the breast cancer-derived MCF-7 cells.
Treatments that increase O-GlcNAcylation (PUGNAc and/or glucosoamine) protected
MCF-7 cells from death induced by tamoxifen. In contrast, inhibition of OGT
expression by siRNA potentiated the effect of tamoxifen on cell death. Since the
PI-3 kinase/Akt pathway is a major regulator of cell survival, we used BRET to
evaluate the effect of PUGNAc+glucosamine on PIP3 production. We
observed that these treatments stimulated PIP3 production in MCF-7
cells. This effect was associated with an increase in Akt phosphorylation.
However, the PI-3 kinase inhibitor LY294002, which abolished the effect of
PUGNAc+glucosamine on Akt phosphorylation, did not impair the protective effects
of PUGNAc+glucosamine against tamoxifen-induced cell death. These results
suggest that the protective effects of O-GlcNAcylation are independent of the
PI-3 kinase/Akt pathway. As tamoxifen sensitivity depends on the estrogen
receptor (ERα) expression level, we evaluated the effect of PUGNAc+glucosamine
on the expression of this receptor. We observed that O-GlcNAcylation-inducing
treatment significantly reduced the expression of ERα mRNA and protein,
suggesting a potential mechanism for the decreased tamoxifen sensitivity induced
by these treatments. Therefore, our results suggest that inhibition of
O-GlcNAcylation may constitute an interesting approach to improve the
sensitivity of breast cancer to anti-estrogen therapy.
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Affiliation(s)
- Shahzina Kanwal
- Institut Cochin, Université Paris Descartes, CNRS (UMR8104), Paris,
France
- INSERM, U1016, Paris, France
| | - Yann Fardini
- Institut Cochin, Université Paris Descartes, CNRS (UMR8104), Paris,
France
- INSERM, U1016, Paris, France
| | - Patrick Pagesy
- Institut Cochin, Université Paris Descartes, CNRS (UMR8104), Paris,
France
- INSERM, U1016, Paris, France
| | - Thierry N’Tumba-Byn
- Institut Cochin, Université Paris Descartes, CNRS (UMR8104), Paris,
France
- INSERM, U1016, Paris, France
| | - Cécile Pierre-Eugène
- Institut Cochin, Université Paris Descartes, CNRS (UMR8104), Paris,
France
- INSERM, U1016, Paris, France
| | - Elodie Masson
- Institut Cochin, Université Paris Descartes, CNRS (UMR8104), Paris,
France
- INSERM, U1016, Paris, France
| | - Cornelia Hampe
- Institut Cochin, Université Paris Descartes, CNRS (UMR8104), Paris,
France
- INSERM, U1016, Paris, France
| | - Tarik Issad
- Institut Cochin, Université Paris Descartes, CNRS (UMR8104), Paris,
France
- INSERM, U1016, Paris, France
- * E-mail:
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Ramjiawan A, Bagchi RA, Blant A, Albak L, Cavasin MA, Horn TR, McKinsey TA, Czubryt MP. Roles of histone deacetylation and AMP kinase in regulation of cardiomyocyte PGC-1α gene expression in hypoxia. Am J Physiol Cell Physiol 2013; 304:C1064-72. [DOI: 10.1152/ajpcell.00262.2012] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The transcriptional coactivator peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) is a key determinant of cardiac metabolic function by regulating genes governing fatty acid oxidation and mitochondrial biogenesis. PGC-1α expression is reduced in many cardiac diseases, and gene deletion of PGC-1α results in impaired cardiomyocyte metabolism and function. Reduced fuel supply generally induces PGC-1α expression, but the specific role of oxygen deprivation is unclear, and the mechanisms governing PGC-1α gene expression in these situations are poorly understood. During hypoxia of primary rat cardiomyocytes up to 12 h, we found that PGC-1α expression was downregulated via a histone deacetylation-dependent mechanism. Conversely, extended hypoxia to 24 h concomitant with glucose depletion upregulated PGC-1α expression via an AMP-activated protein kinase (AMPK)-mediated mechanism. Our previous work demonstrated that estrogen-related receptor-α (ERRα) regulates PGC-1α expression, and we show here that overexpression of ERRα was sufficient to attenuate PGC-1α downregulation in hypoxia. We confirmed that chronic hypoxia downregulated cardiac PGC-1α expression in a hypoxic but nonischemic hypobaric rat model of pulmonary hypertension. Our data demonstrate that depletion of oxygen or fuel results in repression or induction, respectively, of PGC-1α expression via discrete mechanisms, which may contribute to cardiac energetic derangement during hypoxia, ischemia, and failure.
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Affiliation(s)
- Angela Ramjiawan
- Institute of Cardiovascular Sciences, St. Boniface General Hospital Research Centre and Department of Physiology, University of Manitoba, Winnipeg, Manitoba, Canada; and
| | | | - Alexandra Blant
- Institute of Cardiovascular Sciences, St. Boniface General Hospital Research Centre and Department of Physiology, University of Manitoba, Winnipeg, Manitoba, Canada; and
| | - Laura Albak
- Institute of Cardiovascular Sciences, St. Boniface General Hospital Research Centre and Department of Physiology, University of Manitoba, Winnipeg, Manitoba, Canada; and
| | - Maria A. Cavasin
- Department of Medicine, Division of Cardiology, University of Colorado Denver, Aurora, Colorado
| | - Todd R. Horn
- Department of Medicine, Division of Cardiology, University of Colorado Denver, Aurora, Colorado
| | - Timothy A. McKinsey
- Department of Medicine, Division of Cardiology, University of Colorado Denver, Aurora, Colorado
| | - Michael P. Czubryt
- Institute of Cardiovascular Sciences, St. Boniface General Hospital Research Centre and Department of Physiology, University of Manitoba, Winnipeg, Manitoba, Canada; and
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Abstract
To maintain homeostasis under variable nutrient conditions, cells rapidly and robustly respond to fluctuations through adaptable signaling networks. Evidence suggests that the O-linked N-acetylglucosamine (O-GlcNAc) posttranslational modification of serine and threonine residues functions as a critical regulator of intracellular signaling cascades in response to nutrient changes. O-GlcNAc is a highly regulated, reversible modification poised to integrate metabolic signals and acts to influence many cellular processes, including cellular signaling, protein stability, and transcription. This review describes the role O-GlcNAc plays in governing both integrated cellular processes and the activity of individual proteins in response to nutrient levels. Moreover, we discuss the ways in which cellular changes in O-GlcNAc status may be linked to chronic diseases such as type 2 diabetes, neurodegeneration, and cancers, providing a unique window through which to identify and treat disease conditions.
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Affiliation(s)
- Michelle R. Bond
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892; ,
| | - John A. Hanover
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892; ,
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Abstract
Forkhead box O (FOXO) transcription factors are involved in the regulation of the cell cycle, apoptosis and metabolism. In model organisms, FOXO activity also affects stem cell maintenance and lifespan as well as age-related diseases, such as cancer and diabetes. Multiple upstream pathways regulate FOXO activity through post-translational modifications and nuclear-cytoplasmic shuttling of both FOXO and its regulators. The diversity of this upstream regulation and the downstream effects of FOXOs suggest that they function as homeostasis regulators to maintain tissue homeostasis over time and coordinate a response to environmental changes, including growth factor deprivation, metabolic stress (starvation) and oxidative stress.
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Fardini Y, Dehennaut V, Lefebvre T, Issad T. O-GlcNAcylation: A New Cancer Hallmark? Front Endocrinol (Lausanne) 2013; 4:99. [PMID: 23964270 PMCID: PMC3740238 DOI: 10.3389/fendo.2013.00099] [Citation(s) in RCA: 191] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Accepted: 07/26/2013] [Indexed: 12/11/2022] Open
Abstract
O-linked N-acetylglucosaminylation (O-GlcNAcylation) is a reversible post-translational modification consisting in the addition of a sugar moiety to serine/threonine residues of cytosolic or nuclear proteins. Catalyzed by O-GlcNAc-transferase (OGT) and removed by O-GlcNAcase, this dynamic modification is dependent on environmental glucose concentration. O-GlcNAcylation regulates the activities of a wide panel of proteins involved in almost all aspects of cell biology. As a nutrient sensor, O-GlcNAcylation can relay the effects of excessive nutritional intake, an important cancer risk factor, on protein activities and cellular functions. Indeed, O-GlcNAcylation has been shown to play a significant role in cancer development through different mechanisms. O-GlcNAcylation and OGT levels are increased in different cancers (breast, prostate, colon…) and vary during cell cycle progression. Modulating their expression or activity can alter cancer cell proliferation and/or invasion. Interestingly, major oncogenic factors have been shown to be directly O-GlcNAcylated (p53, MYC, NFκB, β-catenin…). Furthermore, chromatin dynamics is modulated by O-GlcNAc. DNA methylation enzymes of the Tet family, involved epigenetic alterations associated with cancer, were recently found to interact with and target OGT to multi-molecular chromatin-remodeling complexes. Consistently, histones are subjected to O-GlcNAc modifications which regulate their function. Increasing number of evidences point out the central involvement of O-GlcNAcylation in tumorigenesis, justifying the attention received as a potential new approach for cancer treatment. However, comprehension of the underlying mechanism remains at its beginnings. Future challenge will be to address directly the role of O-GlcNAc-modified residues in oncogenic-related proteins to eventually propose novel strategies to alter cancer development and/or progression.
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Affiliation(s)
- Yann Fardini
- Institut Cochin, Université Paris Descartes, CNRS (UMR8104), Paris, France
- INSERM, U1016, Paris, France
| | - Vanessa Dehennaut
- CNRS/UMR 8576, Unit of Structural and Functional Glycobiology, Institut Fédératif de Recherche IFR 147, Lille 1 University, Villeneuve d’Ascq, France
| | - Tony Lefebvre
- CNRS/UMR 8576, Unit of Structural and Functional Glycobiology, Institut Fédératif de Recherche IFR 147, Lille 1 University, Villeneuve d’Ascq, France
| | - Tarik Issad
- Institut Cochin, Université Paris Descartes, CNRS (UMR8104), Paris, France
- INSERM, U1016, Paris, France
- *Correspondence: Tarik Issad, Department of Endocrinology, Metabolism and Diabetes, Institut Cochin, 22 rue Méchain, 75014 Paris, France e-mail:
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Puthanveetil P, Wan A, Rodrigues B. FoxO1 is crucial for sustaining cardiomyocyte metabolism and cell survival. Cardiovasc Res 2012; 97:393-403. [PMID: 23263330 DOI: 10.1093/cvr/cvs426] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Diabetic cardiomyopathy is a term used to describe cardiac muscle damage-induced heart failure. Multiple structural and biochemical reasons have been suggested to induce this disorder. The most prominent feature of the diabetic myocardium is attenuated insulin signalling that reduces survival kinases (Akt), potentially switching on protein targets like FoxOs, initiators of cell death. FoxO1, a prominent member of the forkhead box family and subfamily O of transcription factors and produced from the FKHR gene, is involved in regulating metabolism, cell proliferation, oxidative stress response, immune homeostasis, pluripotency in embryonic stem cells, and cell death. In this review we describe distinctive functions of FoxOs, specifically FoxO1 under conditions of nutrient excess, insulin resistance and diabetes, and its manipulation to restore metabolic equilibrium to limit cardiac damage due to cell death. Because FoxO1 helps cardiac tissue to combat a variety of stress stimuli, it could be a major determinant in regulating diabetic cardiomyopathy. In this regard, we highlight studies from our group and others who illustrate how cardiac tissue-specific FoxO1 deletion protects the heart against cardiomyopathy and how its down-regulation in endothelial tissue could prevent against atherosclerotic plaques. In addition, we also describe studies that show FoxO1's beneficial qualities by highlighting their role in inducing anti-oxidant, autophagic, and anti-apoptotic genes under stress conditions of ischaemia-reperfusion and myocardial infarction. Thus, the aforementioned FoxO1 traits could be useful in curbing cardiac tissue-specific impairment of function following diabetes.
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Affiliation(s)
- Prasanth Puthanveetil
- Faculty of Pharmaceutical Sciences, The University of British Columbia, 2146 East Mall, Vancouver, BC, Canada V6T 1Z3
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O-GlcNAcylation and oxidation of proteins: is signalling in the cardiovascular system becoming sweeter? Clin Sci (Lond) 2012; 123:473-86. [PMID: 22757958 PMCID: PMC3389386 DOI: 10.1042/cs20110638] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
O-GlcNAcylation is an unusual form of protein glycosylation, where a single-sugar [GlcNAc (N-acetylglucosamine)] is added (via β-attachment) to the hydroxyl moiety of serine and threonine residues of nuclear and cytoplasmic proteins. A complex and extensive interplay exists between O-GlcNAcylation and phosphorylation. Many phosphorylation sites are also known glycosylation sites, and this reciprocal occupancy may produce different activities or alter the stability in a target protein. The interplay between these two post-translational modifications is not always reciprocal, as some proteins can be concomitantly phosphorylated and O-GlcNAcylated, and the adjacent phosphorylation or O-GlcNAcylation can regulate the addition of either moiety. Increased cardiovascular production of ROS (reactive oxygen species), termed oxidative stress, has been consistently reported in various chronic diseases and in conditions where O-GlcNAcylation has been implicated as a contributing mechanism for the associated organ injury/protection (for example, diabetes, Alzheimer's disease, arterial hypertension, aging and ischaemia). In the present review, we will briefly comment on general aspects of O-GlcNAcylation and provide an overview of what has been reported for this post-translational modification in the cardiovascular system. We will then specifically address whether signalling molecules involved in redox signalling can be modified by O-GlcNAc (O-linked GlcNAc) and will discuss the critical interplay between O-GlcNAcylation and ROS generation. Experimental evidence indicates that the interactions between O-GlcNAcylation and oxidation of proteins are important not only for cell regulation in physiological conditions, but also under pathological states where the interplay may become dysfunctional and thereby exacerbate cellular injury.
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Ruan HB, Han X, Li MD, Singh JP, Qian K, Azarhoush S, Zhao L, Bennett AM, Samuel VT, Wu J, Yates JR, Yang X. O-GlcNAc transferase/host cell factor C1 complex regulates gluconeogenesis by modulating PGC-1α stability. Cell Metab 2012; 16:226-37. [PMID: 22883232 PMCID: PMC3480732 DOI: 10.1016/j.cmet.2012.07.006] [Citation(s) in RCA: 226] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Revised: 03/21/2012] [Accepted: 07/11/2012] [Indexed: 01/01/2023]
Abstract
A major cause of hyperglycemia in diabetic patients is inappropriate hepatic gluconeogenesis. PGC-1α is a master regulator of gluconeogenesis, and its activity is controlled by various posttranslational modifications. A small portion of glucose metabolizes through the hexosamine biosynthetic pathway, which leads to O-linked β-N-acetylglucosamine (O-GlcNAc) modification of cytoplasmic and nuclear proteins. Using a proteomic approach, we identified a broad variety of proteins associated with O-GlcNAc transferase (OGT), among which host cell factor C1 (HCF-1) is highly abundant. HCF-1 recruits OGT to O-GlcNAcylate PGC-1α, and O-GlcNAcylation facilitates the binding of the deubiquitinase BAP1, thus protecting PGC-1α from degradation and promoting gluconeogenesis. Glucose availability modulates gluconeogenesis through the regulation of PGC-1α O-GlcNAcylation and stability by the OGT/HCF-1 complex. Hepatic knockdown of OGT and HCF-1 improves glucose homeostasis in diabetic mice. These findings define the OGT/HCF-1 complex as a glucose sensor and key regulator of gluconeogenesis, shedding light on new strategies for treating diabetes.
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Affiliation(s)
- Hai-Bin Ruan
- Program in Integrative Cell Signaling and Neurobiology of Metabolism, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06519, USA
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Cifarelli V, Lee S, Kim DH, Zhang T, Kamagate A, Slusher S, Bertera S, Luppi P, Trucco M, Dong HH. FOXO1 mediates the autocrine effect of endothelin-1 on endothelial cell survival. Mol Endocrinol 2012; 26:1213-24. [PMID: 22570335 DOI: 10.1210/me.2011-1276] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Chronic hyperglycemia exerts a deleterious effect on endothelium, contributing to endothelial dysfunction and microvascular complications in poorly controlled diabetes. To understand the underlying mechanism, we studied the effect of endothelin-1 (ET-1) on endothelial production of Forkhead box O1 (FOXO1), a forkhead transcription factor that plays an important role in cell survival. ET-1 is a 21-amino acid peptide that is secreted primarily from endothelium. Using adenovirus-mediated gene transfer approach, we delivered FOXO1 cDNA into cultured human aorta endothelial cells. FOXO1 was shown to stimulate B cell leukemia/lymphoma 2-associated death promoter (BAD) production and promote cellular apoptosis. This effect was counteracted by ET-1. In response to ET-1, FOXO1 was phosphorylated and translocated from the nucleus to cytoplasm, resulting in inhibition of BAD production and mitigation of FOXO1-mediated apoptosis. Hyperglycemia stimulated FOXO1 O-glycosylation and promoted its nuclear localization in human aorta endothelial cells. This effect accounted for unbridled FOXO1 activity in the nucleus, contributing to augmented BAD production and endothelial apoptosis under hyperglycemic conditions. FOXO1 expression became deregulated in the aorta of both streptozotocin-induced diabetic mice and diabetic db/db mice. This hyperglycemia-elicited FOXO1 deregulation and its ensuing effect on endothelial cell survival was corrected by ET-1. Likewise, FoxO1 deregulation in the aorta of diabetic mice was reversible after the reduction of hyperglycemia by insulin therapy. These data reveal a mechanism by which FOXO1 mediated the autocrine effect of ET-1 on endothelial cell survival. FOXO1 deregulation, resulting from an impaired ability of ET-1 to control FOXO1 activity in endothelium, may contribute to hyperglycemia-induced endothelial lesion in diabetes.
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Affiliation(s)
- Vincenza Cifarelli
- Division of Immunogenetics, Department of Pediatrics, Children’s Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15224, USA
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Role of transcription factor modifications in the pathogenesis of insulin resistance. EXPERIMENTAL DIABETES RESEARCH 2011; 2012:716425. [PMID: 22110478 PMCID: PMC3205681 DOI: 10.1155/2012/716425] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/26/2011] [Accepted: 07/25/2011] [Indexed: 02/06/2023]
Abstract
Non-alcoholic fatty liver disease (NAFLD) is characterized by fat accumulation in the liver not due to alcohol abuse. NAFLD is accompanied by variety of symptoms related to metabolic syndrome. Although the metabolic link between NAFLD and insulin resistance is not fully understood, it is clear that NAFLD is one of the main cause of insulin resistance. NAFLD is shown to affect the functions of other organs, including pancreas, adipose tissue, muscle and inflammatory systems. Currently efforts are being made to understand molecular mechanism of interrelationship between NAFLD and insulin resistance at the transcriptional level with specific focus on post-translational modification (PTM) of transcription factors. PTM of transcription factors plays a key role in controlling numerous biological events, including cellular energy metabolism, cell-cycle progression, and organ development. Cell type- and tissue-specific reversible modifications include lysine acetylation, methylation, ubiquitination, and SUMOylation. Moreover, phosphorylation and O-GlcNAcylation on serine and threonine residues have been shown to affect protein stability, subcellular distribution, DNA-binding affinity, and transcriptional activity. PTMs of transcription factors involved in insulin-sensitive tissues confer specific adaptive mechanisms in response to internal or external stimuli. Our understanding of the interplay between these modifications and their effects on transcriptional regulation is growing. Here, we summarize the diverse roles of PTMs in insulin-sensitive tissues and their involvement in the pathogenesis of insulin resistance.
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NADPH oxidase activation by hyperglycaemia in cardiomyocytes is independent of glucose metabolism but requires SGLT1. Cardiovasc Res 2011; 92:237-46. [DOI: 10.1093/cvr/cvr230] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
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Cheong CY, Lon Ng PM, Ponnampalam R, Tsai HH, Bourque G, Lufkin T. In silico tandem affinity purification refines an Oct4 interaction list. Stem Cell Res Ther 2011; 2:26. [PMID: 21569470 PMCID: PMC3218817 DOI: 10.1186/scrt67] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2011] [Revised: 04/05/2011] [Accepted: 05/13/2011] [Indexed: 02/11/2023] Open
Abstract
INTRODUCTION Octamer-binding transcription factor 4 (Oct4) is a master regulator of early mammalian development. Its expression begins from the oocyte stage, becomes restricted to the inner cell mass of the blastocyst and eventually remains only in primordial germ cells. Unearthing the interactions of Oct4 would provide insight into how this transcription factor is central to cell fate and stem cell pluripotency. METHODS In the present study, affinity-tagged endogenous Oct4 cell lines were established via homologous recombination gene targeting in embryonic stem (ES) cells to express tagged Oct4. This allows tagged Oct4 to be expressed without altering the total Oct4 levels from their physiological levels. RESULTS Modified ES cells remained pluripotent. However, when modified ES cells were tested for their functionality, cells with a large tag failed to produce viable homozygous mice. Use of a smaller tag resulted in mice with normal development, viability and fertility. This indicated that the choice of tags can affect the performance of Oct4. Also, different tags produce a different repertoire of Oct4 interactors. CONCLUSIONS Using a total of four different tags, we found 33 potential Oct4 interactors, of which 30 are novel. In addition to transcriptional regulation, the molecular function associated with these Oct4-associated proteins includes various other catalytic activities, suggesting that, aside from chromosome remodeling and transcriptional regulation, Oct4 function extends more widely to other essential cellular mechanisms. Our findings show that multiple purification approaches are needed to uncover a comprehensive Oct4 protein interaction network.
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Affiliation(s)
- Clara Yujing Cheong
- Stem Cell and Developmental Biology Group, Genome Institute of Singapore, 60 Biopolis Street, 138672, Singapore
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O-linked-N-acetylglucosamine cycling and insulin signaling are required for the glucose stress response in Caenorhabditis elegans. Genetics 2011; 188:369-82. [PMID: 21441213 DOI: 10.1534/genetics.111.126490] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
In a variety of organisms, including worms, flies, and mammals, glucose homeostasis is maintained by insulin-like signaling in a robust network of opposing and complementary signaling pathways. The hexosamine signaling pathway, terminating in O-linked-N-acetylglucosamine (O-GlcNAc) cycling, is a key sensor of nutrient status and has been genetically linked to the regulation of insulin signaling in Caenorhabditis elegans. Here we demonstrate that O-GlcNAc cycling and insulin signaling are both essential components of the C. elegans response to glucose stress. A number of insulin-dependent processes were found to be sensitive to glucose stress, including fertility, reproductive timing, and dauer formation, yet each of these differed in their threshold of sensitivity to glucose excess. Our findings suggest that O-GlcNAc cycling and insulin signaling are both required for a robust and adaptable response to glucose stress, but these two pathways show complex and interdependent roles in the maintenance of glucose-insulin homeostasis.
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Abstract
O-GlcNAcylation corresponds to the addition of N-acetylglucosamine on serine and threonine residues of cytosolic and nuclear proteins. O-GlcNAcylation is a dynamic post-translational modification, analogous to phosphorylation, that regulates the stability, the activity or the sub-cellular localisation of proteins. This reversible modification depends on the availability of glucose and therefore constitutes a powerful means by which cellular activities are regulated according to the nutritional environment of the cell. O-GlcNAcylation has been implicated in important human pathologies including Alzheimer disease and type-2 diabetes. Only two enzymes, OGT and O-GlcNAcase, control the O-GlcNAcylation level on proteins, and thereby regulate signaling pathways. Several lines of evidence indicate that OGT attenuates insulin signal by O-GlcNAcylation of proteins involved in proximal and distal steps in the signaling pathway. This negative feedback may be exacerbated when cells are exposed to elevated glucose concentrations as observed in diabetic patients, and could thereby contribute to insulin resistance and worsening of hyperglycaemia. double dagger.
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Issad T, Masson E, Pagesy P. O-GlcNAc modification, insulin signaling and diabetic complications. DIABETES & METABOLISM 2010; 36:423-35. [PMID: 21074472 DOI: 10.1016/j.diabet.2010.09.001] [Citation(s) in RCA: 123] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 06/24/2010] [Revised: 09/16/2010] [Accepted: 09/17/2010] [Indexed: 11/24/2022]
Abstract
O-GlcNAc glycosylation (O-GlcNAcylation) corresponds to the addition of N-acetylglucosamine on serine and threonine residues of cytosolic and nuclear proteins. O-GlcNAcylation is a dynamic post-translational modification, analogous to phosphorylation, that regulates the stability, the activity or the subcellular localisation of target proteins. This reversible modification depends on the availability of glucose and therefore constitutes a powerful mechanism by which cellular activities are regulated according to the nutritional environment of the cell. O-GlcNAcylation has been implicated in important human pathologies including Alzheimer disease and type-2 diabetes. Only two enzymes, OGT and O-GlcNAcase, control the O-GlcNAc level on proteins. Therefore, O-GlcNAcylations cannot organize in signaling cascades as observed for phosphorylations. O-GlcNAcylations should rather be considered as a "rheostat" that controls the intensity of the signals traveling through different pathways according to the nutritional status of the cell. Thus, OGT attenuates insulin signal by O-GlcNAcylation of proteins involved in proximal and distal steps in the PI-3 kinase signaling pathway. This negative feedback may be exacerbated when cells are chronically exposed to elevated glucose concentrations and could thereby contribute to alterations in insulin signaling observed in diabetic patients. O-GlcNAcylation also appears to contribute to the deleterious effects of hyperglycaemia on excessive glucose production by the liver and deterioration of β-cell pancreatic function, resulting in worsening of hyperglycaemia (glucotoxicity). Moreover, O-GlcNAcylations directly participate in several diabetic complications. O-GlcNAcylation of eNOS in endothelial cells have been involved in micro- and macrovascular complications. In addition, O-GlcNAcylations activate the expression of profibrotic and antifibrinolytic factors, contributing to vascular and renal dysfunctions.
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Affiliation(s)
- T Issad
- CNRS (UMR 8104), université Paris Descartes, institut Cochin, 22 rue Méchain, Paris, France.
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Kim EJ, Love DC, Darout E, Abdo M, Rempel B, Withers SG, Rablen PR, Hanover JA, Knapp S. OGA inhibition by GlcNAc-selenazoline. Bioorg Med Chem 2010; 18:7058-64. [PMID: 20822912 DOI: 10.1016/j.bmc.2010.08.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2010] [Revised: 08/03/2010] [Accepted: 08/04/2010] [Indexed: 12/26/2022]
Abstract
The title compound, which differs from the powerful O-GlcNAcase (OGA) inhibitor GlcNAc-thiazoline only at the chalcogen atom (Se for S), is a much weaker inhibitor in a direct OGA assay. In human cells, however, the selenazoline shows comparable ability to induce hyper-O-GlcNAc-ylation, and the two show similar reduction of insulin-stimulated translocation of glucose transporter 4 in differentiated 3T3 adipocytes.
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Affiliation(s)
- Eun Ju Kim
- Department of Science Education-Chemistry Major, Daegu University, Gyeongbuk 712-714, Republic of Korea
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Hardivillé S, Hoedt E, Mariller C, Benaïssa M, Pierce A. O-GlcNAcylation/phosphorylation cycling at Ser10 controls both transcriptional activity and stability of delta-lactoferrin. J Biol Chem 2010; 285:19205-18. [PMID: 20404350 PMCID: PMC2885199 DOI: 10.1074/jbc.m109.080572] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2009] [Revised: 03/25/2010] [Indexed: 11/06/2022] Open
Abstract
Delta-lactoferrin (DeltaLf) is a transcription factor that up-regulates DcpS, Skp1, and Bax genes, provoking cell cycle arrest and apoptosis. It is post-translationally modified either by O-GlcNAc or phosphate, but the effects of the O-GlcNAc/phosphorylation interplay on DeltaLf function are not yet understood. Here, using a series of glycosylation mutants, we showed that Ser(10) is O-GlcNAcylated and that this modification is associated with increased DeltaLf stability, achieved by blocking ubiquitin-dependent proteolysis, demonstrating that O-GlcNAcylation protects against polyubiquitination. We highlighted the (391)KSQQSSDPDPNCVD(404) sequence as a functional PEST motif responsible for DeltaLf degradation and defined Lys(379) as the main polyubiquitin acceptor site. We next investigated the control of DeltaLf transcriptional activity by the O-GlcNAc/phosphorylation interplay. Reporter gene analyses using the Skp1 promoter fragment containing a DeltaLf response element showed that O-GlcNAcylation at Ser(10) negatively regulates DeltaLf transcriptional activity, whereas phosphorylation activates it. Using a chromatin immunoprecipitation assay, we showed that O-GlcNAcylation inhibits DNA binding. Deglycosylation leads to DNA binding and transactivation of the Skp1 promoter at a basal level. Basal transactivation was markedly enhanced by 2-3-fold when phosphorylation was mimicked at Ser(10) by aspartate. Moreover, using double chromatin immunoprecipitation assays, we showed that the DeltaLf transcriptional complex binds to the DeltaLf response element and is phosphorylated and/or ubiquitinated, suggesting that DeltaLf transcriptional activity and degradation are concomitant events. Collectively, our results indicate that reciprocal occupancy of Ser(10) by either O-phosphate or O-GlcNAc coordinately regulates DeltaLf stability and transcriptional activity.
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Affiliation(s)
- Stéphan Hardivillé
- From the Unité de Glycobiologie Structurale et Fonctionnelle, Unité Mixte de Recherche 8576 CNRS, Université des Sciences et Technologies de Lille, IFR 147, 59655 Villeneuve d'Ascq, France
| | - Esthelle Hoedt
- From the Unité de Glycobiologie Structurale et Fonctionnelle, Unité Mixte de Recherche 8576 CNRS, Université des Sciences et Technologies de Lille, IFR 147, 59655 Villeneuve d'Ascq, France
| | - Christophe Mariller
- From the Unité de Glycobiologie Structurale et Fonctionnelle, Unité Mixte de Recherche 8576 CNRS, Université des Sciences et Technologies de Lille, IFR 147, 59655 Villeneuve d'Ascq, France
| | - Monique Benaïssa
- From the Unité de Glycobiologie Structurale et Fonctionnelle, Unité Mixte de Recherche 8576 CNRS, Université des Sciences et Technologies de Lille, IFR 147, 59655 Villeneuve d'Ascq, France
| | - Annick Pierce
- From the Unité de Glycobiologie Structurale et Fonctionnelle, Unité Mixte de Recherche 8576 CNRS, Université des Sciences et Technologies de Lille, IFR 147, 59655 Villeneuve d'Ascq, France
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Ozcan S, Andrali SS, Cantrell JEL. Modulation of transcription factor function by O-GlcNAc modification. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2010; 1799:353-64. [PMID: 20202486 DOI: 10.1016/j.bbagrm.2010.02.005] [Citation(s) in RCA: 183] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 09/25/2009] [Revised: 02/19/2010] [Accepted: 02/25/2010] [Indexed: 12/22/2022]
Abstract
O-linked beta-N-acetylglucosamine (O-GlcNAc) modification of nuclear and cytoplasmic proteins is important for many cellular processes, and the number of proteins that contain this modification is steadily increasing. This modification is dynamic and reversible, and in some cases competes for phosphorylation of the same residues. O-GlcNAc modification of proteins is regulated by cell cycle, nutrient metabolism, and other extracellular signals. Compared to protein phosphorylation, which is mediated by a large number of kinases, O-GlcNAc modification is catalyzed only by one enzyme called O-linked N-acetylglucosaminyl transferase or OGT. Removal of O-GlcNAc from proteins is catalyzed by the enzyme beta-N-acetylglucosaminidase (O-GlcNAcase or OGA). Altered O-linked GlcNAc modification levels contribute to the establishment of many diseases, such as cancer, diabetes, cardiovascular disease, and neurodegeneration. Many transcription factors have been shown to be modified by O-linked GlcNAc modification, which can influence their transcriptional activity, DNA binding, localization, stability, and interaction with other co-factors. This review focuses on modulation of transcription factor function by O-linked GlcNAc modification.
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Affiliation(s)
- Sabire Ozcan
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY 40536, USA.
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Kang JG, Park SY, Ji S, Jang I, Park S, Kim HS, Kim SM, Yook JI, Park YI, Roth J, Cho JW. O-GlcNAc protein modification in cancer cells increases in response to glucose deprivation through glycogen degradation. J Biol Chem 2009; 284:34777-84. [PMID: 19833729 DOI: 10.1074/jbc.m109.026351] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
When cellular glucose concentrations fall below normal levels, in general the extent of protein O-GlcNAc modification (O-GlcNAcylation) decreases. However, recent reports demonstrated increased O-GlcNAcylation by glucose deprivation in HepG2 and Neuro-2a cells. Here, we report increased O-GlcNAcylation in non-small cell lung carcinoma A549 cells and various other cells in response to glucose deprivation. Although the level of O-GlcNAc transferase was unchanged, the enzyme contained less O-GlcNAc, and its activity was increased. Moreover, O-GlcNAcase activity was reduced. The studied cells contain glycogen, and we show that its degradation in response to glucose deprivation provides a source for UDP-GlcNAc required for increased O-GlcNAcylation under this condition. This required active glycogen phosphorylase and resulted in increased glutamine:fructose-6-phosphate amidotransferase, the first and rate-limiting enzyme in the hexosamine biosynthetic pathway. Interestingly, glucose deprivation reduced the amount of phosphofructokinase 1, a regulatory glycolytic enzyme, and blocked ATP synthesis. These findings suggest that glycogen is the source for increased O-GlcNAcylation but not for generating ATP in response to glucose deprivation and that this may be useful for cancer cells to survive.
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Affiliation(s)
- Jeong Gu Kang
- Department of Biology, Oral Cancer Research Institute, Korea
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Lefebvre T, Dehennaut V, Guinez C, Olivier S, Drougat L, Mir AM, Mortuaire M, Vercoutter-Edouart AS, Michalski JC. Dysregulation of the nutrient/stress sensor O-GlcNAcylation is involved in the etiology of cardiovascular disorders, type-2 diabetes and Alzheimer's disease. Biochim Biophys Acta Gen Subj 2009; 1800:67-79. [PMID: 19732809 DOI: 10.1016/j.bbagen.2009.08.008] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2009] [Revised: 08/17/2009] [Accepted: 08/24/2009] [Indexed: 11/19/2022]
Abstract
O-GlcNAcylation is widespread within the cytosolic and nuclear compartments of cells. This post-translational modification is likely an indicator of good health since its intracellular level correlates with the availability of extracellular glucose. Apart from its status as a nutrient sensor, O-GlcNAcylation may also act as a stress sensor since it exerts its fundamental effects in response to stress. Several studies report that the cell quickly responds to an insult by elevating O-GlcNAcylation levels and by unmasking a newly described Hsp70-GlcNAc binding property. From a more practical point of view, it has been shown that O-GlcNAcylation impairments contribute to the etiology of cardiovascular diseases, type-2 diabetes and Alzheimer's disease (AD), three illnesses common in occidental societies. Many studies have demonstrated that O-GlcNAcylation operates as a powerful cardioprotector and that by raising O-GlcNAcylation levels, the organism more successfully resists trauma-hemorrhage and ischemia/reperfusion injury. Recent data have also shown that insulin resistance and, more broadly, type-2 diabetes can be controlled by O-GlcNAcylation of the insulin pathway and O-GlcNAcylation of the gluconeogenesis transcription factors FoxO1 and CRCT2. Lastly, the finding that AD may correspond to a type-3 diabetes offers new perspectives into the knowledge of the neuropathology and into the search for new therapeutic avenues.
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Affiliation(s)
- Tony Lefebvre
- CNRS-UMR 8576, Unit of Structural and Functional Glycobiology, IFR 147, University of Lille 1, Villeneuve d'Ascq, France.
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Jung YA, Lee KM, Kim MK, Jung GS, Seo YJ, Kim HS, Cho HC, Lee KU, Park KG, Lee IK. Forkhead transcription factor FoxO1 inhibits insulin- and transforming growth factor-beta-stimulated plasminogen activator inhibitor-1 expression. Biochem Biophys Res Commun 2009; 386:757-61. [PMID: 19563779 DOI: 10.1016/j.bbrc.2009.06.124] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2009] [Accepted: 06/24/2009] [Indexed: 01/08/2023]
Abstract
Elevated levels of plasminogen activator inhibitor-1 (PAI-1) are considered a risk factor for chronic liver disease in patients with hyperinsulinemia. Insulin increases the expression of PAI-1, and inactivates the forkhead box-containing protein FoxO1. We were interested in whether the inactivation of FoxO1 is involved in the activation of PAI-1 expression under conditions of insulin stimulation. Here, we examined whether adenoviral-mediated expression of a constitutively active form of FoxO1 (Ad-CA-FoxO1) inhibited insulin-stimulated PAI-1 expression in human HepG2 hepatocellular liver carcinoma cells and mouse AML12 hepatocytes. Treatment of cells with insulin increased PAI-1 gene expression, and this effect was abolished by Ad-CA-FoxO1. Insulin also increased the transforming growth factor (TGF)-beta-induced expression of PAI-1 mRNA, and Ad-CA-FoxO1 inhibited this effect. Transient transfection assays using a reporter gene under the control of the PAI-1 promoter revealed that CA-FoxO1 inhibits Smad3-stimulated PAI-1 promoter activity. Taken together, our results indicate that FoxO1 inhibits PAI-1 expression through the inhibition of TGF-beta/Smad-mediated signaling pathways. Our data also suggest that in the hyperinsulinemic state, FoxO1 is inactivated by increased levels of insulin, and does not function as an inhibitor of TGF-beta-induced PAI-1 expression.
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Affiliation(s)
- Yun-A Jung
- Department of Internal Medicine and Institute for Medical Science, Keimyung University School of Medicine, 194 Dongsan-dong, Jung-gu, Daegu 700-712, South Korea
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