1
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Besli N, Ercin N, Carmena-Bargueño M, Sarikamis B, Kalkan Cakmak R, Yenmis G, Pérez-Sánchez H, Beker M, Kilic U. Research into how carvacrol and metformin affect several human proteins in a hyperglycemic condition: A comparative study in silico and in vitro. Arch Biochem Biophys 2024; 758:110062. [PMID: 38880320 DOI: 10.1016/j.abb.2024.110062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Revised: 04/30/2024] [Accepted: 06/13/2024] [Indexed: 06/18/2024]
Abstract
Carvacrol (CV) is an organic compound found in the essential oils of many aromatic herbs. It is nearly unfeasible to analyze all the current human proteins for a query ligand using in vitro and in vivo methods. This study aimed to clarify whether CV possesses an anti-diabetic feature via Docking-based inverse docking and molecular dynamic (MD) simulation and in vitro characterization against a set of novel human protein targets. Herein, the best poses of CV docking simulations according to binding energy ranged from -7.9 to -3.5 (kcal/mol). After pathway analysis of the protein list through GeneMANIA and WebGestalt, eight interacting proteins (DPP4, FBP1, GCK, HSD11β1, INSR, PYGL, PPARA, and PPARG) with CV were determined, and these proteins exhibited stable structures during the MD process with CV. In vitro application, statistically significant results were achieved only in combined doses with CV or metformin. Considering all these findings, PPARG and INSR, among these target proteins of CV, are FDA-approved targets for treating diabetes. Therefore, CV may be on its way to becoming a promising therapeutic compound for treating Diabetes Mellitus (DM). Our outcomes expose formerly unexplored potential target human proteins, whose association with diabetic disorders might guide new potential treatments for DM.
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Affiliation(s)
- Nail Besli
- Department of Medical Biology, Hamidiye School of Medicine, University of Health Sciences, Istanbul, Turkey.
| | - Nilufer Ercin
- Department of Medical Biology, Hamidiye School of Medicine, University of Health Sciences, Istanbul, Turkey.
| | - Miguel Carmena-Bargueño
- Structural Bioinformatics and High Performance Computing Research Group (BIO-HPC), Computer Engineering Department, UCAM Universidad Católica de Murcia, Guadalupe, Spain.
| | - Bahar Sarikamis
- Department of Medical Biology, Institute of Health Sciences, University of Health Sciences, Istanbul, Turkey.
| | - Rabia Kalkan Cakmak
- Department of Medical Biology, Hamidiye School of Medicine, University of Health Sciences, Istanbul, Turkey; Department of Medical Biology, Institute of Health Sciences, University of Health Sciences, Istanbul, Turkey.
| | - Guven Yenmis
- Department of Medical Biology, Faculty of Medicine, Biruni University, Istanbul, Turkey.
| | - Horacio Pérez-Sánchez
- Structural Bioinformatics and High Performance Computing Research Group (BIO-HPC), Computer Engineering Department, UCAM Universidad Católica de Murcia, Guadalupe, Spain.
| | - Merve Beker
- Department of Medical Biology, International School of Medicine, University of Health Sciences, Istanbul, Turkey.
| | - Ulkan Kilic
- Department of Medical Biology, Hamidiye School of Medicine, University of Health Sciences, Istanbul, Turkey; Department of Medical Biology, Institute of Health Sciences, University of Health Sciences, Istanbul, Turkey.
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2
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Zhang P, Yang J, Liu X, Huang C, Tao Y, Shen P, Bai Z, Xiao C, Zhou L, Li G, Zhang L, Zhou W, Gao Y. FBP1 orchestrates keratinocyte proliferation/differentiation and suppresses psoriasis through metabolic control of histone acetylation. Cell Death Dis 2024; 15:392. [PMID: 38834617 PMCID: PMC11150480 DOI: 10.1038/s41419-024-06706-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 04/13/2024] [Accepted: 04/24/2024] [Indexed: 06/06/2024]
Abstract
Keratinocyte proliferation and differentiation in epidermis are well-controlled and essential for reacting to stimuli such as ultraviolet light. Imbalance between proliferation and differentiation is a characteristic feature of major human skin diseases such as psoriasis and squamous cell carcinoma. However, the effect of keratinocyte metabolism on proliferation and differentiation remains largely elusive. We show here that the gluconeogenic enzyme fructose-1,6-bisphosphatase 1 (FBP1) promotes differentiation while inhibits proliferation of keratinocyte and suppresses psoriasis development. FBP1 is identified among the most upregulated genes induced by UVB using transcriptome sequencing and is elevated especially in upper epidermis. Fbp1 heterozygous mice exhibit aberrant epidermis phenotypes with local hyperplasia and dedifferentiation. Loss of FBP1 promotes proliferation and inhibits differentiation of keratinocytes in vitro. Mechanistically, FBP1 loss facilitates glycolysis-mediated acetyl-CoA production, which increases histone H3 acetylation at lysine 9, resulting in enhanced transcription of proliferation genes. We further find that the expression of FBP1 is dramatically reduced in human psoriatic lesions and in skin of mouse imiquimod psoriasis model. Fbp1 deficiency in mice facilitates psoriasis-like skin lesions development through glycolysis and acetyl-CoA production. Collectively, our findings reveal a previously unrecognized role of FBP1 in epidermal homeostasis and provide evidence for FBP1 as a metabolic psoriasis suppressor.
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Affiliation(s)
- Pengfei Zhang
- Department of Pharmaceutical Sciences, Beijing Institute of Radiation Medicine, Beijing, 100850, China
| | - Ju Yang
- Department of Dermatology, The General Hospital of Western Theater Command PLA, Chengdu, Sichuan, 610083, China
| | - Xiong Liu
- Department of Information, The PLA Center for Disease Control and Prevention, Beijing, China
| | - Congshu Huang
- Department of Pharmaceutical Sciences, Beijing Institute of Radiation Medicine, Beijing, 100850, China
| | - Yuandong Tao
- Department of Pediatric Urology, The Seventh Medical Center of Chinese PLA General Hospital, Beijing, China
| | - Pan Shen
- Department of Pharmaceutical Sciences, Beijing Institute of Radiation Medicine, Beijing, 100850, China
| | - Zhijie Bai
- Department of Pharmaceutical Sciences, Beijing Institute of Radiation Medicine, Beijing, 100850, China
| | - Chengrong Xiao
- Department of Pharmaceutical Sciences, Beijing Institute of Radiation Medicine, Beijing, 100850, China
| | - Lei Zhou
- Department of Pharmaceutical Sciences, Beijing Institute of Radiation Medicine, Beijing, 100850, China
| | - Gaofu Li
- Department of Pharmaceutical Sciences, Beijing Institute of Radiation Medicine, Beijing, 100850, China
| | - Li Zhang
- Department of Information, The PLA Center for Disease Control and Prevention, Beijing, China
| | - Wei Zhou
- Department of Pharmaceutical Sciences, Beijing Institute of Radiation Medicine, Beijing, 100850, China.
| | - Yue Gao
- Department of Pharmaceutical Sciences, Beijing Institute of Radiation Medicine, Beijing, 100850, China.
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3
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Ding T, Wen B, Chen J, Chu W, Fan R, Chen X. Excess homocysteine inhibits pancreatic β-cell secretory function by repressing Zbtb20 expression. Mol Cell Endocrinol 2024; 586:112195. [PMID: 38432501 DOI: 10.1016/j.mce.2024.112195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 02/22/2024] [Accepted: 02/25/2024] [Indexed: 03/05/2024]
Abstract
Homocysteine (Hcy) is a sulfur-containing amino acid. An elevated level of Hcy is a risk factor for diabetes development. However, the mechanism of its effect on pancreatic β-cell function is unclear. In this study, we constructed a hyperhomocysteinemia (HHcy) mouse model by feeding mice a high methionine diet (HMD). The mice suffered impaired glucose tolerance and reduced insulin secretion. Furthermore, at the cellular level, INS1 cells exhibited impaired insulin secretory function after the Hcy intervention. Transcriptomics revealed that Zbtb20 expression was downregulated and the downstream gene Fbp1 was upregulated in HHcy-induced mice compared with mice fed with normal diet. Insulin secretion could be restored by Zbtb20 overexpression or fructose 1,6-bisphosphatase (FBPase) activity inhibition in INS1 cells. In conclusion, our study suggested that Hcy inhibited the insulin secretory function of pancreatic β-cells by suppressing Zbtb20 expression, leading to the development of diabetes. Zbtb20 may be a key target in the development of diabetes associated with elevated Hcy levels.
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Affiliation(s)
- Tianqi Ding
- Tianjin Institute of Environmental and Operational Medicine, Tianjin, 300050, China
| | - Bo Wen
- Tianjin Institute of Environmental and Operational Medicine, Tianjin, 300050, China
| | - Jian Chen
- Tianjin Institute of Environmental and Operational Medicine, Tianjin, 300050, China
| | - Wenbin Chu
- Tianjin Institute of Environmental and Operational Medicine, Tianjin, 300050, China
| | - Rong Fan
- Tianjin Institute of Environmental and Operational Medicine, Tianjin, 300050, China; Central Laboratory, Tianjin Xiqing Hospital, Tianjin, 300380, China.
| | - Xuewei Chen
- Tianjin Institute of Environmental and Operational Medicine, Tianjin, 300050, China.
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4
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Pack M, Gulde TN, Völcker MV, Boewe AS, Wrublewsky S, Ampofo E, Montenarh M, Götz C. Protein Kinase CK2 Contributes to Glucose Homeostasis by Targeting Fructose-1,6-Bisphosphatase 1. Int J Mol Sci 2022; 24:ijms24010428. [PMID: 36613872 PMCID: PMC9820633 DOI: 10.3390/ijms24010428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 12/16/2022] [Accepted: 12/23/2022] [Indexed: 12/28/2022] Open
Abstract
Glucose homeostasis is of critical importance for the survival of organisms. It is under hormonal control and often coordinated by the action of kinases and phosphatases. We have previously shown that CK2 regulates insulin production and secretion in pancreatic β-cells. In order to shed more light on the CK2-regulated network of glucose homeostasis, in the present study, a qRT-PCR array was carried out with 84 diabetes-associated genes. After inhibition of CK2, fructose-1,6-bisphosphatase 1 (FBP1) showed a significant lower gene expression. Moreover, FBP1 activity was down-regulated. Being a central enzyme of gluconeogenesis, the secretion of glucose was decreased as well. Thus, FBP1 is a new factor in the CK2-regulated network implicated in carbohydrate metabolism control.
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Affiliation(s)
- Mandy Pack
- Medical Biochemistry and Molecular Biology, Saarland University, Building 44, 66421 Homburg, Germany
| | - Tim Nikolai Gulde
- Medical Biochemistry and Molecular Biology, Saarland University, Building 44, 66421 Homburg, Germany
| | - Michelle Victoria Völcker
- Medical Biochemistry and Molecular Biology, Saarland University, Building 44, 66421 Homburg, Germany
| | - Anne S. Boewe
- Institute for Clinical and Experimental Surgery, Saarland University, Building 65, 66421 Homburg, Germany
| | - Selina Wrublewsky
- Institute for Clinical and Experimental Surgery, Saarland University, Building 65, 66421 Homburg, Germany
| | - Emmanuel Ampofo
- Institute for Clinical and Experimental Surgery, Saarland University, Building 65, 66421 Homburg, Germany
| | - Mathias Montenarh
- Medical Biochemistry and Molecular Biology, Saarland University, Building 44, 66421 Homburg, Germany
| | - Claudia Götz
- Medical Biochemistry and Molecular Biology, Saarland University, Building 44, 66421 Homburg, Germany
- Correspondence:
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5
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Analysis of the expression, function and signaling of glycogen phosphorylase isoforms in hepatocellular carcinoma. Oncol Lett 2022; 24:244. [PMID: 35761940 PMCID: PMC9214699 DOI: 10.3892/ol.2022.13364] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 05/11/2022] [Indexed: 11/23/2022] Open
Abstract
Glycogen phosphorylase (GP) is an essential enzyme for glycolysis via the glycogen degradation pathway. It consists of three isoforms: PYGB (brain form), PYGL (liver form) and PYGM (muscle form). Although the abnormal expression of GP is associated with a variety of tumors, its relationship with hepatocellular carcinoma (HCC) and whether it can be used as a prognostic marker of HCC remains unclear. In the present study, the expression levels of PYGB, PYGL and PYGM were analyzed. It was found that the expression levels of PYGB in tumor tissues were higher than those in normal tissues, particularly in HCC. The high expression of PYGB (hazard ratios=1.801; 95% confidence interval: 1.266-2.562) could predict the poor prognosis of HCC patients but not PYGL and PYGM. Inhibition of PYGB with GP inhibitor CP91149 significantly suppressed the HCC cell proliferation in the HCC cell model. In addition, combination treatment with sorafenib, a standard treatment for HCC, showed a great inhibition on tumor growth and angiogenesis. These findings suggested that PYGB may be used as a therapeutic and prognostic indicator for HCC.
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6
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Filippatos TD, Alexakis K, Mavrikaki V, Mikhailidis DP. Nonalcoholic Fatty Pancreas Disease: Role in Metabolic Syndrome, "Prediabetes," Diabetes and Atherosclerosis. Dig Dis Sci 2022; 67:26-41. [PMID: 33469809 DOI: 10.1007/s10620-021-06824-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Accepted: 01/05/2021] [Indexed: 02/06/2023]
Abstract
Fat accumulation in the pancreas associated with obesity and the metabolic syndrome (MetS) has been defined as "non-alcoholic fatty pancreas disease" (NAFPD). The aim of this review is to describe the association of NAFPD with obesity, MetS, type 2 diabetes mellitus (T2DM) and atherosclerosis and also increase awareness regarding NAFPD. Various methods are used for the detection and quantification of pancreatic fat accumulation that may play a significant role in the differences that have been observed in the prevalence of NAFPD. Endoscopic ultrasound provides detailed images of the pancreas and its use is expected to increase in the future. Obesity and MetS have been recognized as NAFPD risk factors. NAFPD is strongly associated with non-alcoholic fatty liver disease (NAFLD) and it seems that the presence of both may be related with aggravation of NAFLD. A role of NAFPD in the development of "prediabetes" and T2DM has also been suggested by most human studies. Accumulation of fat in pancreatic tissue possibly initiates a vicious cycle of beta-cell deterioration and further pancreatic fat accumulation. Additionally, some evidence indicates a correlation between NAFPD and atherosclerotic markers (e.g., carotid intima-media thickness). Weight loss and bariatric surgery decreases pancreatic triglyceride content but pharmacologic treatments for NAFPD have not been evaluated in specifically designed studies. Hence, NAFPD is a marker of local fat accumulation possibly associated with beta-cell function impairment, carbohydrate metabolism disorders and atherosclerosis.
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Affiliation(s)
- T D Filippatos
- Metabolic Diseases Research Unit, Internal Medicine Laboratory, School of Medicine, Faculty of Medicine, University of Crete, P.O. Box 2208, Heraklion, Crete, Greece.
| | - K Alexakis
- Metabolic Diseases Research Unit, Internal Medicine Laboratory, School of Medicine, Faculty of Medicine, University of Crete, P.O. Box 2208, Heraklion, Crete, Greece
| | - V Mavrikaki
- Metabolic Diseases Research Unit, Internal Medicine Laboratory, School of Medicine, Faculty of Medicine, University of Crete, P.O. Box 2208, Heraklion, Crete, Greece
| | - D P Mikhailidis
- Department of Clinical Biochemistry, Royal Free Campus, University College London Medical School, University College London (UCL), London, NW3 2QG, UK.,Mohammed Bin Rashid University (MBRU) of Medicine and Health Sciences, Dubai, United Arab Emirates
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7
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Wang X, Zhao R, Ji W, Zhou J, Liu Q, Zhao L, Shen Z, Liu S, Xu B. Discovery of Novel Indole Derivatives as Fructose-1,6-bisphosphatase Inhibitors and X-ray Cocrystal Structures Analysis. ACS Med Chem Lett 2021; 13:118-127. [PMID: 35059131 PMCID: PMC8762752 DOI: 10.1021/acsmedchemlett.1c00613] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 12/15/2021] [Indexed: 01/16/2023] Open
Abstract
Liver fructose-1,6-bisphosphatase (FBPase) is a key enzyme in the gluconeogenesis, and its inhibitors are expected to be novel antidiabetic agents. Herein, a series of new indole and benzofuran analogues were designed and synthesized to evaluate the inhibitory activity against FBPase. As a result, the novel FBPase inhibitors bearing N-acylsulfonamide moiety on the 3-position of the indole-2-carboxylic acid scaffold (compounds 22f and 22g) were identified with IC50s at the submicromolar levels. Three X-ray crystal structures of the complexes were solved and revealed the structural basis for the inhibitory activity. The chemoinformatics analysis further disclosed the distinct binding features of this class of inhibitors, providing an insight for further modifications to create structurally distinct FBPase inhibitors with high potency and drug-like properties.
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Affiliation(s)
- Xiaoyu Wang
- Beijing
Key Laboratory of Active Substances Discovery and Druggability Evaluation,
Institute of Materia Medica, Chinese Academy
of Medical Sciences and Peking Union Medical College, Beijing, 100050, China
| | - Rui Zhao
- Beijing
Key Laboratory of Active Substances Discovery and Druggability Evaluation,
Institute of Materia Medica, Chinese Academy
of Medical Sciences and Peking Union Medical College, Beijing, 100050, China,School
of Pharmaceutical Engineering, Shenyang
Pharmaceutical University, Shenyang, 100016, China
| | - Wenming Ji
- State
Key Laboratory of Bioactive Substances and Functions of Natural Medicines,
Institute of Materia Medica, Chinese Academy
of Medical Sciences and Peking Union Medical College, Beijing, 100050, China,Diabetes
Research Center, Chinese Academy of Medical
Sciences and Peking Union Medical College, Beijing, 100050, China
| | - Jie Zhou
- Beijing
Key Laboratory of Active Substances Discovery and Druggability Evaluation,
Institute of Materia Medica, Chinese Academy
of Medical Sciences and Peking Union Medical College, Beijing, 100050, China
| | - Quan Liu
- State
Key Laboratory of Bioactive Substances and Functions of Natural Medicines,
Institute of Materia Medica, Chinese Academy
of Medical Sciences and Peking Union Medical College, Beijing, 100050, China,Diabetes
Research Center, Chinese Academy of Medical
Sciences and Peking Union Medical College, Beijing, 100050, China
| | - Linxiang Zhao
- School
of Pharmaceutical Engineering, Shenyang
Pharmaceutical University, Shenyang, 100016, China
| | - Zhufang Shen
- State
Key Laboratory of Bioactive Substances and Functions of Natural Medicines,
Institute of Materia Medica, Chinese Academy
of Medical Sciences and Peking Union Medical College, Beijing, 100050, China,Diabetes
Research Center, Chinese Academy of Medical
Sciences and Peking Union Medical College, Beijing, 100050, China
| | - Shuainan Liu
- State
Key Laboratory of Bioactive Substances and Functions of Natural Medicines,
Institute of Materia Medica, Chinese Academy
of Medical Sciences and Peking Union Medical College, Beijing, 100050, China,Diabetes
Research Center, Chinese Academy of Medical
Sciences and Peking Union Medical College, Beijing, 100050, China,S.L. email,
| | - Bailing Xu
- Beijing
Key Laboratory of Active Substances Discovery and Druggability Evaluation,
Institute of Materia Medica, Chinese Academy
of Medical Sciences and Peking Union Medical College, Beijing, 100050, China,B.X.: email,
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8
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High-Fructose Diet Alters Intestinal Microbial Profile and Correlates with Early Tumorigenesis in a Mouse Model of Barrett’s Esophagus. Microorganisms 2021; 9:microorganisms9122432. [PMID: 34946037 PMCID: PMC8708753 DOI: 10.3390/microorganisms9122432] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Revised: 11/16/2021] [Accepted: 11/18/2021] [Indexed: 12/12/2022] Open
Abstract
Esophageal adenocarcinoma (EAC) is mostly prevalent in industrialized countries and has been associated with obesity, commonly linked with a diet rich in fat and refined sugars containing high fructose concentrations. In meta-organisms, dietary components are digested and metabolized by the host and its gut microbiota. Fructose has been shown to induce proliferation and cell growth in pancreas and colon cancer cell lines and also alter the gut microbiota. In a previous study with the L2-IL-1B mouse model, we showed that a high-fat diet (HFD) accelerated EAC progression from its precursor lesion Barrett’s esophagus (BE) through changes in the gut microbiota. Aiming to investigate whether a high-fructose diet (HFrD) also alters the gut microbiota and favors EAC carcinogenesis, we assessed the effects of HFrD on the phenotype and intestinal microbial communities of L2-IL1B mice. Results showed a moderate acceleration in histologic disease progression, a mild effect on the systemic inflammatory response, metabolic changes in the host, and a shift in the composition, metabolism, and functionality of intestinal microbial communities. We conclude that HFrD alters the overall balance of the gut microbiota and induces an acceleration in EAC progression in a less pronounced manner than HFD.
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9
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Han X, Huang Y, Wei L, Chen H, Guo Y, Tang Z, Hu W, Xia Q, Wang Q, Yan J, Ren Y. Biological evaluation and SAR analysis of novel covalent inhibitors against fructose-1,6-bisphosphatase. Bioorg Med Chem 2020; 28:115624. [PMID: 32828433 DOI: 10.1016/j.bmc.2020.115624] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 06/12/2020] [Accepted: 06/16/2020] [Indexed: 11/25/2022]
Abstract
Fructose-1,6-bisphosphatase (FBPase) is an attractive target for affecting the GNG pathway. In our previous study, the C128 site of FBPase has been identified as a new allosteric site, where several nitrovinyl compounds can bind to inhibit FBPase activity. Herein, a series of nitrostyrene derivatives were further synthesized, and their inhibitory activities against FBPase were investigated in vitro. Most of the prepared nitrostyrene compounds exhibit potent FBPase inhibition (IC50 < 10 μM). Specifically, when the substituents of F, Cl, OCH3, CF3, OH, COOH, or 2-nitrovinyl were installed at the R2 (meta-) position of the benzene ring, the FBPase inhibitory activities of the resulting compounds increased 4.5-55 folds compared to those compounds with the same groups at the R1 (para-) position. In addition, the preferred substituents at the R3 position were Cl or Br, thus compound HS36 exhibited the most potent inhibitory activity (IC50 = 0.15 μM). The molecular docking and site-directed mutation suggest that C128 and N125 are essential for the binding of HS36 and FBPase, which is consistent with the C128-N125-S123 allosteric inhibition mechanism. The reaction enthalpy calculations show that the order of the reactions of compounds with thiol groups at the R3 position is Cl > H > CH3. CoMSIA analysis is consistent with our proposed binding mode. The effect of compounds HS12 and HS36 on glucose production in primary mouse hepatocytes were further evaluated, showing that the inhibition was 71% and 41% at 100 μM, respectively.
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Affiliation(s)
- Xinya Han
- School of Chemistry and Chemical Engineering, Anhui University of Technology, Maanshan 243002, China
| | - Yunyuan Huang
- International Cooperation Base of Pesticide and Green Synthesis (Hubei), Key Laboratory of Pesticide & Chemical Biology (CCNU), Ministry of Education, Department of Chemistry, Central China Normal University, Wuhan 430079, China
| | - Lin Wei
- International Cooperation Base of Pesticide and Green Synthesis (Hubei), Key Laboratory of Pesticide & Chemical Biology (CCNU), Ministry of Education, Department of Chemistry, Central China Normal University, Wuhan 430079, China
| | - Haifeng Chen
- Ocean College, Beibu Gulf University, Qinzhou 535011, China
| | - Yanrong Guo
- School of Chemistry and Chemical Engineering, Anhui University of Technology, Maanshan 243002, China
| | - Zilong Tang
- Key Laboratory of Theoretical Chemistry and Molecular Simulation of Ministry of Education, Hunan University of Science and Technology, Xiangtan 411201, China
| | - Wei Hu
- School of Chemistry and Chemical Engineering, Anhui University of Technology, Maanshan 243002, China
| | - Qinfei Xia
- School of Chemistry and Chemical Engineering, Anhui University of Technology, Maanshan 243002, China
| | - Qi Wang
- School of Chemistry and Chemical Engineering, Anhui University of Technology, Maanshan 243002, China
| | - Jufen Yan
- School of Chemistry and Chemical Engineering, Anhui University of Technology, Maanshan 243002, China.
| | - Yanliang Ren
- International Cooperation Base of Pesticide and Green Synthesis (Hubei), Key Laboratory of Pesticide & Chemical Biology (CCNU), Ministry of Education, Department of Chemistry, Central China Normal University, Wuhan 430079, China.
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10
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Yang CH, Mangiafico SP, Waibel M, Loudovaris T, Loh K, Thomas HE, Morahan G, Andrikopoulos S. E2f8 and Dlg2 genes have independent effects on impaired insulin secretion associated with hyperglycaemia. Diabetologia 2020; 63:1333-1348. [PMID: 32356104 DOI: 10.1007/s00125-020-05137-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 02/14/2020] [Indexed: 12/11/2022]
Abstract
AIMS/HYPOTHESIS Reduced insulin secretion results in hyperglycaemia and diabetes involving a complex aetiology that is yet to be fully elucidated. Genetic susceptibility is a key factor in beta cell dysfunction and hyperglycaemia but the responsible genes have not been defined. The Collaborative Cross (CC) is a recombinant inbred mouse panel with diverse genetic backgrounds allowing the identification of complex trait genes that are relevant to human diseases. The aim of this study was to identify and characterise genes associated with hyperglycaemia. METHODS Using an unbiased genome-wide association study, we examined random blood glucose and insulin sensitivity in 53 genetically unique mouse strains from the CC population. The influences of hyperglycaemia susceptibility quantitative trait loci (QTLs) were investigated by examining glucose tolerance, insulin secretion, pancreatic histology and gene expression in the susceptible mice. Expression of candidate genes and their association with insulin secretion were examined in human islets. Mechanisms underlying reduced insulin secretion were studied in MIN6 cells using RNA interference. RESULTS Wide variations in blood glucose levels and the related metabolic traits (insulin sensitivity and body weight) were observed in the CC population. We showed that elevated blood glucose in the CC strains was not due to insulin resistance nor obesity but resulted from reduced insulin secretion. This insulin secretory defect was demonstrated to be independent of abnormalities in islet morphology, beta cell mass and pancreatic insulin content. Gene mapping identified the E2f8 (p = 2.19 × 10-15) and Dlg2 loci (p = 3.83 × 10-8) on chromosome 7 to be significantly associated with hyperglycaemia susceptibility. Fine mapping the implicated regions using congenic mice demonstrated that these two loci have independent effects on insulin secretion in vivo. Significantly, our results revealed that increased E2F8 and DLG2 gene expression are correlated with enhanced insulin secretory function in human islets. Furthermore, loss-of-function studies in MIN6 cells demonstrated that E2f8 is involved in insulin secretion through an ATP-sensitive K+ channel-dependent pathway, which leads to a 30% reduction in Abcc8 expression. Similarly, knockdown of Dlg2 gene expression resulted in impaired insulin secretion in response to glucose and non-glucose stimuli. CONCLUSIONS/INTERPRETATION Collectively, these findings suggest that E2F transcription factor 8 (E2F8) and discs large homologue 2 (DLG2) regulate insulin secretion. The CC resource enables the identification of E2f8 and Dlg2 as novel genes associated with hyperglycaemia due to reduced insulin secretion in pancreatic beta cells. Taken together, our results provide better understanding of the molecular control of insulin secretion and further support the use of the CC resource to identify novel genes relevant to human diseases.
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Affiliation(s)
- Chieh-Hsin Yang
- Department of Medicine (Austin Health), Austin Hospital, University of Melbourne, Level 7, Lance Townsend Building, Studley Road, Heidelberg, VIC, 3084, Australia.
- St Vincent's Institute of Medical Research, 9 Princes Street, Fitzroy, VIC, 3065, Australia.
| | - Salvatore P Mangiafico
- Department of Medicine (Austin Health), Austin Hospital, University of Melbourne, Level 7, Lance Townsend Building, Studley Road, Heidelberg, VIC, 3084, Australia
| | - Michaela Waibel
- St Vincent's Institute of Medical Research, 9 Princes Street, Fitzroy, VIC, 3065, Australia
| | - Thomas Loudovaris
- St Vincent's Institute of Medical Research, 9 Princes Street, Fitzroy, VIC, 3065, Australia
| | - Kim Loh
- St Vincent's Institute of Medical Research, 9 Princes Street, Fitzroy, VIC, 3065, Australia
| | - Helen E Thomas
- St Vincent's Institute of Medical Research, 9 Princes Street, Fitzroy, VIC, 3065, Australia
| | - Grant Morahan
- Harry Perkins Institute of Medical Research, Nedlands, WA, Australia
| | - Sofianos Andrikopoulos
- Department of Medicine (Austin Health), Austin Hospital, University of Melbourne, Level 7, Lance Townsend Building, Studley Road, Heidelberg, VIC, 3084, Australia.
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11
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Gao XH, Li L, Parisien M, Wu J, Bederman I, Gao Z, Krokowski D, Chirieleison SM, Abbott D, Wang B, Arvan P, Cameron M, Chance M, Willard B, Hatzoglou M. Discovery of a Redox Thiol Switch: Implications for Cellular Energy Metabolism. Mol Cell Proteomics 2020; 19:852-870. [PMID: 32132231 PMCID: PMC7196587 DOI: 10.1074/mcp.ra119.001910] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 01/27/2020] [Indexed: 11/06/2022] Open
Abstract
The redox-based modifications of cysteine residues in proteins regulate their function in many biological processes. The gas molecule H2S has been shown to persulfidate redox sensitive cysteine residues resulting in an H2S-modified proteome known as the sulfhydrome. Tandem Mass Tags (TMT) multiplexing strategies for large-scale proteomic analyses have become increasingly prevalent in detecting cysteine modifications. Here we developed a TMT-based proteomics approach for selectively trapping and tagging cysteine persulfides in the cellular proteomes. We revealed the natural protein sulfhydrome of two human cell lines, and identified insulin as a novel substrate in pancreatic beta cells. Moreover, we showed that under oxidative stress conditions, increased H2S can target enzymes involved in energy metabolism by switching specific cysteine modifications to persulfides. Specifically, we discovered a Redox Thiol Switch, from protein S-glutathioinylation to S-persulfidation (RTSGS). We propose that the RTSGS from S-glutathioinylation to S-persulfidation is a potential mechanism to fine tune cellular energy metabolism in response to different levels of oxidative stress.
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Affiliation(s)
- Xing-Huang Gao
- Department of Genetics, Case Western Reserve University, Cleveland, OH.
| | - Ling Li
- Mass Spectrometry Laboratory for Protein Sequencing, The Lerner Research Institute, Cleveland, OH
| | - Marc Parisien
- Alan Edwards Centre for Research on Pain McGill University, Montreal, Canada
| | - Jing Wu
- Department of Genetics, Case Western Reserve University, Cleveland, OH
| | - Ilya Bederman
- Department of Pediatrics, Case Western Reserve University, Cleveland, OH
| | - Zhaofeng Gao
- Department of Genetics, Case Western Reserve University, Cleveland, OH
| | - Dawid Krokowski
- Department of Genetics, Case Western Reserve University, Cleveland, OH; Department of Molecular Biology, Maria Curie-Sklodowska University, Lublin, Poland
| | | | - Derek Abbott
- Department of Pathology,Case Western Reserve University, OH
| | - Benlian Wang
- Department of Nutrition, Center for Proteomics and Bioinformatics, Case Western Reserve University, OH
| | - Peter Arvan
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI
| | - Mark Cameron
- Department of Population and Quantitative Health Sciences, Case Western Reserve University, OH
| | - Mark Chance
- Department of Nutrition, Center for Proteomics and Bioinformatics, Case Western Reserve University, OH; Case Center for Synchrotron Biosciences, Brookhaven National Laboratory, NY
| | - Belinda Willard
- Mass Spectrometry Laboratory for Protein Sequencing, The Lerner Research Institute, Cleveland, OH
| | - Maria Hatzoglou
- Department of Genetics, Case Western Reserve University, Cleveland, OH.
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12
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Feng Y, Qiu WL, Yu XX, Zhang Y, He MY, Li LC, Yang L, Zhang W, Franti M, Ye J, Hoeck JD, Xu CR. Characterizing pancreatic β-cell heterogeneity in the streptozotocin model by single-cell transcriptomic analysis. Mol Metab 2020; 37:100982. [PMID: 32247924 PMCID: PMC7184252 DOI: 10.1016/j.molmet.2020.100982] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 03/18/2020] [Accepted: 03/19/2020] [Indexed: 12/15/2022] Open
Abstract
Objectives The streptozotocin (STZ) model is widely used in diabetes research. However, the cellular and molecular states of pancreatic endocrine cells in this model remain unclear. This study explored the molecular characteristics of islet cells treated with STZ and re-evaluated β-cell dysfunction and regeneration in the STZ model. Methods We performed single-cell RNA sequencing of pancreatic endocrine cells from STZ-treated mice. High-quality sequencing data from 2,999 cells were used to identify clusters via Louvain clustering analysis. Principal component analysis (PCA), t-distributed stochastic neighbor embedding (t-SNE), uniform manifold approximation and projection (UMAP), force-directed layout (FDL), and differential expression analysis were used to define the heterogeneity and transcriptomic changes in islet cells. In addition, qPCR and immunofluorescence staining were used to confirm findings from the sequencing data. Results Untreated β-cells were divided into two populations at the transcriptomic level, a large high-Glut2 expression (Glut2high) population and a small low-Glut2 expression (Glut2low) population. At the transcriptomic level, Glut2low β-cells in adult mice did not represent a developmentally immature state, although a fraction of genes associated with β-cell maturation and function were downregulated in Glut2low cells. After a single high-dose STZ treatment, most Glut2high cells were killed, but Glut2low cells survived and over time changed to a distinct cell state. We did not observe conversion of Glut2low to Glut2high β-cells up to 9 months after STZ treatment. In addition, we did not detect transcriptomic changes in the non-β endocrine cells or a direct trans-differentiation pathway from the α-cell lineage to the β-cell lineage in the STZ model. Conclusions We identified the heterogeneity of β-cells in both physiological and pathological conditions. However, we did not observe conversion of Glut2low to Glut2high β-cells, transcriptomic changes in the non-β endocrine cells, or direct trans-differentiation from the α-cell lineage to the β-cell lineage in the STZ model. Our results clearly define the states of islet cells treated with STZ and allow us to re-evaluate the STZ model widely used in diabetes studies. β-cells show heterogeneity in both physiological and pathological conditions. Glut2low β-cells survive from high dose of STZ, but over time change to a distinct cell state. The expression profiles of non-β endocrine cells rarely change in the STZ model. Glut2low β-cells do not represent a developmentally immature state.
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Affiliation(s)
- Ye Feng
- Ministry of Education Key Laboratory of Cell Proliferation and Differentiation, College of Life Sciences, Peking-Tsinghua Center for Life Sciences, China; PKU-Tsinghua-NIBS Graduate Program, China
| | - Wei-Lin Qiu
- Ministry of Education Key Laboratory of Cell Proliferation and Differentiation, College of Life Sciences, Peking-Tsinghua Center for Life Sciences, China; PKU-Tsinghua-NIBS Graduate Program, China
| | - Xin-Xin Yu
- Ministry of Education Key Laboratory of Cell Proliferation and Differentiation, College of Life Sciences, Peking-Tsinghua Center for Life Sciences, China; Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
| | - Yu Zhang
- Ministry of Education Key Laboratory of Cell Proliferation and Differentiation, College of Life Sciences, Peking-Tsinghua Center for Life Sciences, China; Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
| | - Mao-Yang He
- Ministry of Education Key Laboratory of Cell Proliferation and Differentiation, College of Life Sciences, Peking-Tsinghua Center for Life Sciences, China; PKU-Tsinghua-NIBS Graduate Program, China
| | - Lin-Chen Li
- Ministry of Education Key Laboratory of Cell Proliferation and Differentiation, College of Life Sciences, Peking-Tsinghua Center for Life Sciences, China; Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
| | - Li Yang
- Ministry of Education Key Laboratory of Cell Proliferation and Differentiation, College of Life Sciences, Peking-Tsinghua Center for Life Sciences, China; Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
| | - Weiyi Zhang
- Department of Research Beyond Borders, Boehringer Ingelheim (China) Investment Co., Beijing, China
| | - Michael Franti
- Department of Research Beyond Borders, Boehringer Ingelheim Pharmaceuticals, Ridgefield, CT, USA
| | - Junqing Ye
- Department of Research Beyond Borders, Boehringer Ingelheim (China) Investment Co., Beijing, China.
| | - Joerg D Hoeck
- Department of Research Beyond Borders, Boehringer Ingelheim Pharmaceuticals, Ridgefield, CT, USA.
| | - Cheng-Ran Xu
- Ministry of Education Key Laboratory of Cell Proliferation and Differentiation, College of Life Sciences, Peking-Tsinghua Center for Life Sciences, China.
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13
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Iguchi T, Goto K, Watanabe K, Hashimoto K, Suzuki T, Kishino H, Fujimoto K, Mori K. Fluoroquinolones suppress gluconeogenesis by inhibiting fructose 1,6-bisphosphatase in primary monkey hepatocytes. Toxicol In Vitro 2020; 65:104786. [PMID: 32004540 DOI: 10.1016/j.tiv.2020.104786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2019] [Revised: 01/08/2020] [Accepted: 01/26/2020] [Indexed: 11/17/2022]
Abstract
Dysglycemia is one of the most serious adverse events associated with the clinical use of certain fluoroquinolones. The purpose of this study was to investigate the effects of the representative fluoroquinolones moxifloxacin and gatifloxacin on hepatic gluconeogenesis using primary monkey hepatocytes. Glucose production was induced after the cells were incubated for 4 h with 10 mM sodium lactate and 1 mM sodium pyruvate as gluconeogenic substrates. Under these conditions, moxifloxacin and gatifloxacin dose-dependently suppressed gluconeogenesis at concentrations of 100 μM or higher. Transcriptome analysis of rate-limiting enzymes involved in hepatic gluconeogenesis revealed that moxifloxacin and gatifloxacin at a concentration of 1000 μM did not affect the expression of key gluconeogenic enzymes such as phosphoenolpyruvate carboxykinase, glucose 6-phosphatase, and fructose 1,6-bisphosphatase. Furthermore, metabolome analysis, in vitro glucose production assay using additional gluconeogenic substrates, and fructose 1,6-bisphosphatase assay using the cell extracts showed that fluoroquinolones enzymatically suppressed hepatic gluconeogenesis by inhibiting fructose 1,6-bisphosphatase. These inhibitory effects may involve in the clinically relevant dysglycemia associated with fluoroquinolones in human.
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Affiliation(s)
- Takuma Iguchi
- Medicinal Safety Research Laboratories, Daiichi Sankyo Co., Ltd., 1-16-13 Kita-Kasai, Edogawa-ku, Tokyo 134-8630, Japan.
| | - Koichi Goto
- Medicinal Safety Research Laboratories, Daiichi Sankyo Co., Ltd., 1-16-13 Kita-Kasai, Edogawa-ku, Tokyo 134-8630, Japan.
| | - Kyoko Watanabe
- Biomarker & Translational Research Department, Daiichi Sankyo Co., Ltd., 1-2-58, Hiromachi, Shinagawa-ku, Tokyo 140-0005, Japan.
| | - Kazuyuki Hashimoto
- Biomarker & Translational Research Department, Daiichi Sankyo Co., Ltd., 1-2-58, Hiromachi, Shinagawa-ku, Tokyo 140-0005, Japan.
| | - Takami Suzuki
- Oncology Research Laboratories I, Daiichi Sankyo Co., Ltd., 1-2-58, Hiromachi, Shinagawa-ku, Tokyo 140-0005, Japan.
| | - Hiroyuki Kishino
- Medicinal Safety Research Laboratories, Daiichi Sankyo Co., Ltd., 1-16-13 Kita-Kasai, Edogawa-ku, Tokyo 134-8630, Japan.
| | - Kazunori Fujimoto
- Medicinal Safety Research Laboratories, Daiichi Sankyo Co., Ltd., 1-16-13 Kita-Kasai, Edogawa-ku, Tokyo 134-8630, Japan.
| | - Kazuhiko Mori
- Medicinal Safety Research Laboratories, Daiichi Sankyo Co., Ltd., 1-16-13 Kita-Kasai, Edogawa-ku, Tokyo 134-8630, Japan.
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14
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Huang Y, Wei L, Han X, Chen H, Ren Y, Xu Y, Song R, Rao L, Su C, Peng C, Feng L, Wan J. Discovery of novel allosteric site and covalent inhibitors of FBPase with potent hypoglycemic effects. Eur J Med Chem 2019; 184:111749. [DOI: 10.1016/j.ejmech.2019.111749] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2019] [Revised: 09/20/2019] [Accepted: 09/28/2019] [Indexed: 12/21/2022]
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15
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Westermeier F, Holyoak T, Asenjo JL, Gatica R, Nualart F, Burbulis I, Bertinat R. Gluconeogenic Enzymes in β-Cells: Pharmacological Targets for Improving Insulin Secretion. Trends Endocrinol Metab 2019; 30:520-531. [PMID: 31213347 DOI: 10.1016/j.tem.2019.05.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 05/14/2019] [Accepted: 05/16/2019] [Indexed: 02/06/2023]
Abstract
Pancreatic β-cells express the gluconeogenic enzymes glucose 6-phosphatase (G6Pase), fructose 1,6-bisphosphatase (FBP), and phosphoenolpyruvate (PEP) carboxykinase (PCK), which modulate glucose-stimulated insulin secretion (GSIS) through their ability to reverse otherwise irreversible glycolytic steps. Here, we review current knowledge about the expression and regulation of these enzymes in the context of manipulating them to improve insulin secretion in diabetics. Because the regulation of gluconeogenic enzymes in β-cells is so poorly understood, we propose novel research avenues to study these enzymes as modulators of insulin secretion and β-cell dysfunction, with especial attention to FBP, which constitutes an attractive target with an inhibitor under clinical evaluation at present.
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Affiliation(s)
- Francisco Westermeier
- FH JOANNEUM Gesellschaft mbH University of Applied Sciences, Institute of Biomedical Science, Eggenberger Allee 13, 8020 Graz, Austria
| | - Todd Holyoak
- Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Joel L Asenjo
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Independencia 631, 5110566 Valdivia, Chile
| | - Rodrigo Gatica
- Escuela de Veterinaria, Facultad de Ciencias, Universidad Mayor, La Pirámide 5750, 8580745 Santiago, Chile
| | - Francisco Nualart
- Centro de Microscopía Avanzada, CMA BIO, Facultad de Ciencias Biológicas, Universidad de Concepción, Casilla 160 C, 4030000 Concepción, Chile
| | - Ian Burbulis
- Department of Biochemistry and Molecular Genetics, School of Medicine, University of Virginia, Jordan Hall Room 6022, 1340 Jefferson Park Avenue, Charlottesville, VA 22908, USA; Escuela de Medicina, Universidad San Sebastián, Sede Patagonia, Lago Panguipulli 1390, 5501842 Puerto Montt, Chile
| | - Romina Bertinat
- Centro de Microscopía Avanzada, CMA BIO, Facultad de Ciencias Biológicas, Universidad de Concepción, Casilla 160 C, 4030000 Concepción, Chile.
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16
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Characterization of recombinant fructose-1,6-bisphosphatase gene mutations: evidence of inhibition/activation of FBPase protein by gene mutation. Biosci Rep 2019; 39:BSR20180960. [PMID: 30683805 PMCID: PMC6386767 DOI: 10.1042/bsr20180960] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 01/10/2019] [Accepted: 01/14/2019] [Indexed: 11/17/2022] Open
Abstract
Specific residues of the highly regulated fructose-1,6-bisphosphatase (FBPase) enzyme serve as important contributors to the catalytic activity of the enzyme. Previous clinical studies exploring the genetic basis of hypoglycemia revealed two significant mutations in the coding region of the FBPase gene in patients with hypoglycemia, linking the AMP-binding site to the active site of the enzyme. In the present study, a full kinetic analysis of similar mutants was performed. Kinetic results of mutants Y164A and M177A revealed an approximate two to three-fold decrease in inhibitory constants (K i's) for natural inhibitors AMP and fructose-2,6-bisphosphate (F2,6-BP) compared with the Wild-type enzyme (WT). A separate mutation (M248D) was performed in the active site of the enzyme to investigate whether the enzyme could be activated. This mutant displayed an approximate seven-fold increase in K i for F2,6-BP. Interfacial mutants L56A and L73A exhibited an increase in K i for F2,6-BP by approximately five-fold. Mutations in the AMP-binding site (K112A and Y113A) demonstrated an eight to nine-fold decrease in AMP inhibition. Additionally, mutant M248D displayed a four-fold decrease in its apparent Michelis constant (K m), and a six-fold increase in catalytic efficiency (CE). The importance-and medical relevance-of specific residues for FBPase structural/functional relationships in both the catalytic site and AMP-binding site is discussed.
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17
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Zhang X, Yang S, Chen J, Su Z. Unraveling the Regulation of Hepatic Gluconeogenesis. Front Endocrinol (Lausanne) 2019; 9:802. [PMID: 30733709 PMCID: PMC6353800 DOI: 10.3389/fendo.2018.00802] [Citation(s) in RCA: 156] [Impact Index Per Article: 31.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 12/20/2018] [Indexed: 02/05/2023] Open
Abstract
Hepatic gluconeogenesis, de novo glucose synthesis from available precursors, plays a crucial role in maintaining glucose homeostasis to meet energy demands during prolonged starvation in animals. The abnormally increased rate of hepatic gluconeogenesis contributes to hyperglycemia in diabetes. Gluconeogenesis is regulated on multiple levels, such as hormonal secretion, gene transcription, and posttranslational modification. We review here the molecular mechanisms underlying the transcriptional regulation of gluconeogenesis in response to nutritional and hormonal changes. The nutrient state determines the hormone release, which instigates the signaling cascades in the liver to modulate the activities of various transcriptional factors through various post-translational modifications like phosphorylation, methylation, and acetylation. AMP-activated protein kinase (AMPK) can mediate the activities of some transcription factors, however its role in the regulation of gluconeogenesis remains uncertain. Metformin, a primary hypoglycemic agent of type 2 diabetes, ameliorates hyperglycemia predominantly through suppression of hepatic gluconeogenesis. Several molecular mechanisms have been proposed to be metformin's mode of action.
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Affiliation(s)
| | | | | | - Zhiguang Su
- Molecular Medicine Research Center and National Clinical Research Center for Geriatrics, West China Hospital, State Key Laboratory of Biotherapy, Sichuan University, Chengdu, China
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18
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Bakshi I, Suryana E, Small L, Quek LE, Brandon AE, Turner N, Cooney GJ. Fructose bisphosphatase 2 overexpression increases glucose uptake in skeletal muscle. J Endocrinol 2018; 237:101-111. [PMID: 29507044 DOI: 10.1530/joe-17-0555] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 03/05/2018] [Indexed: 12/31/2022]
Abstract
Skeletal muscle is a major tissue for glucose metabolism and can store glucose as glycogen, convert glucose to lactate via glycolysis and fully oxidise glucose to CO2 Muscle has a limited capacity for gluconeogenesis but can convert lactate and alanine to glycogen. Gluconeogenesis requires FBP2, a muscle-specific form of fructose bisphosphatase that converts fructose-1,6-bisphosphate (F-1,6-bisP) to fructose-6-phosphate (F-6-P) opposing the activity of the ATP-consuming enzyme phosphofructokinase (PFK). In mammalian muscle, the activity of PFK is normally 100 times higher than FBP2 and therefore energy wasting cycling between PFK and FBP2 is low. In an attempt to increase substrate cycling between F-6-P and F-1,6-bisP and alter glucose metabolism, we overexpressed FBP2 using a muscle-specific adeno-associated virus (AAV-tMCK-FBP2). AAV was injected into the right tibialis muscle of rats, while the control contralateral left tibialis received a saline injection. Rats were fed a chow or 45% fat diet (HFD) for 5 weeks after which, hyperinsulinaemic-euglycaemic clamps were performed. Infection of the right tibialis with AAV-tMCK-FBP2 increased FBP2 activity 10 fold on average in chow and HFD rats (P < 0.0001). Overexpression of FBP2 significantly increased insulin-stimulated glucose uptake in tibialis of chow animals (control 14.3 ± 1.7; FBP2 17.6 ± 1.6 µmol/min/100 g) and HFD animals (control 9.6 ± 1.1; FBP2 11.2 ± 1.1µmol/min/100 g). The results suggest that increasing the capacity for cycling between F-1,6-bisP and F-6-P can increase the metabolism of glucose by introducing a futile cycle in muscle, but this increase is not sufficient to overcome muscle insulin resistance.
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Affiliation(s)
- Ishita Bakshi
- Diabetes and Metabolism DivisionGarvan Institute, Sydney, New South Wales, Australia
| | - Eurwin Suryana
- Diabetes and Metabolism DivisionGarvan Institute, Sydney, New South Wales, Australia
| | - Lewin Small
- Diabetes and Metabolism DivisionGarvan Institute, Sydney, New South Wales, Australia
| | - Lake-Ee Quek
- School of Mathematics and StatisticsUniversity of Sydney, Charles Perkins Centre, Sydney, New South Wales, Australia
| | - Amanda E Brandon
- Diabetes and Metabolism DivisionGarvan Institute, Sydney, New South Wales, Australia
- Sydney Medical SchoolCharles Perkins Centre, University of Sydney, Sydney, New South Wales, Australia
| | - Nigel Turner
- Department of PharmacologySchool of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Gregory J Cooney
- Diabetes and Metabolism DivisionGarvan Institute, Sydney, New South Wales, Australia
- Sydney Medical SchoolCharles Perkins Centre, University of Sydney, Sydney, New South Wales, Australia
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19
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Morales-Prieto N, Ruiz-Laguna J, Abril N. Dietary Se supplementation partially restores the REDOX proteomic map of M. spretus liver exposed to p,p ′-DDE. Food Chem Toxicol 2018; 114:292-301. [DOI: 10.1016/j.fct.2018.02.047] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 02/14/2018] [Accepted: 02/21/2018] [Indexed: 12/29/2022]
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20
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Liu GM, Zhang YM. Targeting FBPase is an emerging novel approach for cancer therapy. Cancer Cell Int 2018; 18:36. [PMID: 29556139 PMCID: PMC5845355 DOI: 10.1186/s12935-018-0533-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Accepted: 03/05/2018] [Indexed: 02/06/2023] Open
Abstract
Cancer is a leading cause of death in both developed and developing countries. Metabolic reprogramming is an emerging hallmark of cancer. Glucose homeostasis is reciprocally controlled by the catabolic glycolysis and anabolic gluconeogenesis pathways. Previous studies have mainly focused on catabolic glycolysis, but recently, FBPase, a rate-limiting enzyme in gluconeogenesis, was found to play critical roles in tumour initiation and progression in several cancer types. Here, we review recent ideas and discoveries that illustrate the clinical significance of FBPase expression in various cancers, the mechanism through which FBPase influences cancer, and the mechanism of FBPase silencing. Furthermore, we summarize some of the drugs targeting FBPase and discuss their potential use in clinical applications and the problems that remain unsolved.
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Affiliation(s)
- Gao-Min Liu
- Department of Hepatobiliary Surgery, Meizhou People's Hospital, No. 38 Huangtang Road, Meizhou, 514000 China
| | - Yao-Ming Zhang
- Department of Hepatobiliary Surgery, Meizhou People's Hospital, No. 38 Huangtang Road, Meizhou, 514000 China
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21
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Joannides CN, Mangiafico SP, Waters MF, Lamont BJ, Andrikopoulos S. Dapagliflozin improves insulin resistance and glucose intolerance in a novel transgenic rat model of chronic glucose overproduction and glucose toxicity. Diabetes Obes Metab 2017; 19:1135-1146. [PMID: 28244693 DOI: 10.1111/dom.12923] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Revised: 02/21/2017] [Accepted: 02/23/2017] [Indexed: 01/16/2023]
Abstract
AIM To determine whether the excretion of glucose improves insulin resistance, impaired insulin secretion or both. MATERIALS AND METHODS Appropriate methods were used to assess insulin sensitivity (euglycaemic-hyperinsulinaemic clamp) and insulin secretion (hyperglycaemic clamp) in insulin-resistant and hyperglycaemic phosphoenolpyruvate carboxykinase (PEPCK) transgenic rats after treatment with the sodium-glucose co-transporter-2 (SGLT2) inhibitor dapagliflozin. RESULTS In 14-week-old rats with hyperglycaemia, insulin resistance and glucose intolerance, 6 weeks of dapagliflozin treatment resulted in lower weight gain, plasma glucose and insulin levels, and improved glucose tolerance, associated with enhanced insulin sensitivity (rate of glucose disappearance: 51.6 ± 2.3 vs 110.6 ± 3.9 µmol/min/kg; P < .005) and glucose uptake in muscle (0.9 ± 0.1 vs 1.7 ± 0.3 µmol/min/100 g; P < .05) and fat (0.23 ± 0.04 vs 0.55 ± 0.10 µmol/min/100 g, P < .05). Additionally, adipose tissue GLUT4 protein levels were increased (0.78 ± 0.05 vs 1.20 ± 0.09 arbitrary units; P < .05), adipocyte count was higher (221.4 ± 17.7 vs 302.3 ± 21.7 per mm2 fat area; P < .05) and adipocyte size was reduced (4631.8 ± 351.5 vs 3397.6 ± 229.4 µm2 , P < .05). There was no improvement, however, in insulin secretion. To determine whether earlier intervention is necessary, 5-week-old PEPCK transgenic rats were treated with dapagliflozin for 9 weeks and insulin secretion assessed. Dapagliflozin resulted in improved plasma glucose and insulin levels, and lower weight gain but, again, insulin secretion was not improved. CONCLUSIONS In this transgenic model of low-grade chronic hyperglycaemia, SGLT2 inhibitor treatment resulted in reduced blood glucose and insulin levels and enhanced glucose tolerance, associated with improved muscle and fat insulin resistance but not improved insulin secretory function.
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Affiliation(s)
- Christos N Joannides
- Department of Medicine, Austin Hospital, University of Melbourne, Heidelberg, Victoria, Australia
| | - Salvatore P Mangiafico
- Department of Medicine, Austin Hospital, University of Melbourne, Heidelberg, Victoria, Australia
| | - Matthew F Waters
- Department of Medicine, Austin Hospital, University of Melbourne, Heidelberg, Victoria, Australia
| | - Benjamin J Lamont
- Department of Medicine, Austin Hospital, University of Melbourne, Heidelberg, Victoria, Australia
| | - Sofianos Andrikopoulos
- Department of Medicine, Austin Hospital, University of Melbourne, Heidelberg, Victoria, Australia
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22
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Brereton MF, Rohm M, Shimomura K, Holland C, Tornovsky-Babeay S, Dadon D, Iberl M, Chibalina MV, Lee S, Glaser B, Dor Y, Rorsman P, Clark A, Ashcroft FM. Hyperglycaemia induces metabolic dysfunction and glycogen accumulation in pancreatic β-cells. Nat Commun 2016; 7:13496. [PMID: 27882918 PMCID: PMC5123088 DOI: 10.1038/ncomms13496] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 10/07/2016] [Indexed: 12/25/2022] Open
Abstract
Insulin secretion from pancreatic β-cells is impaired in all forms of diabetes. The resultant hyperglycaemia has deleterious effects on many tissues, including β-cells. Here we show that chronic hyperglycaemia impairs glucose metabolism and alters expression of metabolic genes in pancreatic islets. In a mouse model of human neonatal diabetes, hyperglycaemia results in marked glycogen accumulation, and increased apoptosis in β-cells. Sulphonylurea therapy rapidly normalizes blood glucose levels, dissipates glycogen stores, increases autophagy and restores β-cell metabolism. Insulin therapy has the same effect but with slower kinetics. Similar changes are observed in mice expressing an activating glucokinase mutation, in in vitro models of hyperglycaemia, and in islets from type-2 diabetic patients. Altered β-cell metabolism may underlie both the progressive impairment of insulin secretion and reduced β-cell mass in diabetes.
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Affiliation(s)
- Melissa F. Brereton
- Department of Physiology, Anatomy and Genetics and OXION, University of Oxford, Parks Road, Oxford OX1 3PT, UK
| | - Maria Rohm
- Department of Physiology, Anatomy and Genetics and OXION, University of Oxford, Parks Road, Oxford OX1 3PT, UK
| | - Kenju Shimomura
- Department of Physiology, Anatomy and Genetics and OXION, University of Oxford, Parks Road, Oxford OX1 3PT, UK
| | - Christian Holland
- Department of Physiology, Anatomy and Genetics and OXION, University of Oxford, Parks Road, Oxford OX1 3PT, UK
| | - Sharona Tornovsky-Babeay
- Endocrinology and Metabolism Service, Hadassah-Hebrew University Medical Center, Jerusalem 91120, Israel
| | - Daniela Dadon
- Department of Developmental Biology and Cancer Research, The Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem 91120, Israel
| | - Michaela Iberl
- Department of Physiology, Anatomy and Genetics and OXION, University of Oxford, Parks Road, Oxford OX1 3PT, UK
| | - Margarita V. Chibalina
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford OX3 7LJ, UK
| | - Sheena Lee
- Department of Physiology, Anatomy and Genetics and OXION, University of Oxford, Parks Road, Oxford OX1 3PT, UK
| | - Benjamin Glaser
- Endocrinology and Metabolism Service, Hadassah-Hebrew University Medical Center, Jerusalem 91120, Israel
| | - Yuval Dor
- Department of Developmental Biology and Cancer Research, The Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem 91120, Israel
| | - Patrik Rorsman
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford OX3 7LJ, UK
| | - Anne Clark
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford OX3 7LJ, UK
| | - Frances M. Ashcroft
- Department of Physiology, Anatomy and Genetics and OXION, University of Oxford, Parks Road, Oxford OX1 3PT, UK
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Shaheen A, Aljebali AMA. A hypothetical model to solve the controversy over the involvement of UCP2 in palmitate-induced β-cell dysfunction. Endocrine 2016; 54:276-283. [PMID: 27491555 DOI: 10.1007/s12020-016-1051-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 07/04/2016] [Indexed: 11/24/2022]
Abstract
The aim of this article is to solve an existing controversy over the involvement of uncoupling protein-2 in the impairment of glucose-stimulated insulin secretion induced by chronic exposure of β-cells to palmitate. We analyzed and compared the results of studies that support and that deny the involvement of uncoupling protein-2 in this impairment. We observed that this impairment could occur in multiple stages. We provide a model in which palmitate-induced impairment of glucose-stimulated insulin secretion is proposed to occur in two stages, early stage and late stage, depending on the integrity of electron supply (glycolysis and Krebs cycle) and transport system through electron transport chain after palmitate treatment. Prolonged exposure of β-cells to palmitate can impair this system. Early-stage impairment occurs due to uncoupling by uncoupling protein-2 when this system is still intact. When this system becomes impaired, late-stage impairment occurs mainly due to reduced glucose-stimulated adenosine triphosphate production independent of uncoupling by uncoupling protein-2. The change in glucose-stimulated oxygen uptake after palmitate treatment reflects the integrity of this system and can be used to differentiate between the two stages. Some β-cells lines and islets appear to be more resistant to palmitate-induced impairment of electron supply and transport system than others, and therefore early stage is prominent in the more resistant cell lines and less prominent or absent in the less resistant cell lines. This may help to resolve the pathogenesis of diabetes and to monitor the progression of palmitate-induced β-cell dysfunction.
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Affiliation(s)
- Alaa Shaheen
- Kafr El-Sharakwa Medical Center, Kafr El-Sharakwa, Aga, Dakahlia, Egypt.
| | - Ahmad M A Aljebali
- Department of Zoology, Faculty of Science, Omar Al Mukhtar University, Bayda, Libya
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Xirouchaki CE, Mangiafico SP, Bate K, Ruan Z, Huang AM, Tedjosiswoyo BW, Lamont B, Pong W, Favaloro J, Blair AR, Zajac JD, Proietto J, Andrikopoulos S. Impaired glucose metabolism and exercise capacity with muscle-specific glycogen synthase 1 (gys1) deletion in adult mice. Mol Metab 2016; 5:221-232. [PMID: 26977394 PMCID: PMC4770268 DOI: 10.1016/j.molmet.2016.01.004] [Citation(s) in RCA: 38] [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: 12/16/2015] [Revised: 01/07/2016] [Accepted: 01/12/2016] [Indexed: 12/26/2022] Open
Abstract
Objective Muscle glucose storage and muscle glycogen synthase (gys1) defects have been associated with insulin resistance. As there are multiple mechanisms for insulin resistance, the specific role of glucose storage defects is not clear. The aim of this study was to examine the effects of muscle-specific gys1 deletion on glucose metabolism and exercise capacity. Methods Tamoxifen inducible and muscle specific gys-1 KO mice were generated using the Cre/loxP system. Mice were subjected to glucose tolerance tests, euglycemic/hyperinsulinemic clamps and exercise tests. Results gys1-KO mice showed ≥85% reduction in muscle gys1 mRNA and protein concentrations, 70% reduction in muscle glycogen levels, postprandial hyperglycaemia and hyperinsulinaemia and impaired glucose tolerance. Under insulin-stimulated conditions, gys1-KO mice displayed reduced glucose turnover and muscle glucose uptake, indicative of peripheral insulin resistance, as well as increased plasma and muscle lactate levels and reductions in muscle hexokinase II levels. gys1-KO mice also exhibited markedly reduced exercise and endurance capacity. Conclusions Thus, muscle-specific gys1 deletion in adult mice results in glucose intolerance due to insulin resistance and reduced muscle glucose uptake as well as impaired exercise and endurance capacity. In brief This study demonstrates why the body prioritises muscle glycogen storage over liver glycogen storage despite the critical role of the liver in supplying glucose to the brain in the fasting state and shows that glycogen deficiency results in impaired glucose metabolism and reduced exercise capacity. Muscle-specific gys1 knockdown in adult mice results in 70% reduction in skeletal muscle glycogen levels. Muscle-specific gys1 knockdown leads to glucose intolerance and peripheral insulin resistance. Muscle glycogen depletion caused impaired performance, as well as fatigue development during exercise.
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Affiliation(s)
| | - Salvatore P Mangiafico
- University of Melbourne, Department of Medicine (Austin Health), Heidelberg, Victoria, 3084, Australia
| | - Katherine Bate
- University of Melbourne, Department of Medicine (Austin Health), Heidelberg, Victoria, 3084, Australia
| | - Zheng Ruan
- University of Melbourne, Department of Medicine (Austin Health), Heidelberg, Victoria, 3084, Australia
| | - Amy M Huang
- University of Melbourne, Department of Medicine (Austin Health), Heidelberg, Victoria, 3084, Australia
| | - Bing Wilari Tedjosiswoyo
- University of Melbourne, Department of Medicine (Austin Health), Heidelberg, Victoria, 3084, Australia
| | - Benjamin Lamont
- University of Melbourne, Department of Medicine (Austin Health), Heidelberg, Victoria, 3084, Australia
| | - Wynne Pong
- University of Melbourne, Department of Medicine (Austin Health), Heidelberg, Victoria, 3084, Australia
| | - Jenny Favaloro
- University of Melbourne, Department of Medicine (Austin Health), Heidelberg, Victoria, 3084, Australia
| | - Amy R Blair
- University of Melbourne, Department of Medicine (Austin Health), Heidelberg, Victoria, 3084, Australia
| | - Jeffrey D Zajac
- University of Melbourne, Department of Medicine (Austin Health), Heidelberg, Victoria, 3084, Australia
| | - Joseph Proietto
- University of Melbourne, Department of Medicine (Austin Health), Heidelberg, Victoria, 3084, Australia
| | - Sofianos Andrikopoulos
- University of Melbourne, Department of Medicine (Austin Health), Heidelberg, Victoria, 3084, Australia.
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Mahesan AM, Ogunyemi D, Kim E, Paul ABM, Chen YDI. Insulin Resistance in Pregnancy Is Correlated with Decreased Insulin Receptor Gene Expression in Omental Adipose: Insulin Sensitivity and Adipose Tissue Gene Expression in Normal Pregnancy. ACTA ACUST UNITED AC 2016. [DOI: 10.4236/jdm.2016.61011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Tasevska N, Park Y, Jiao L, Hollenbeck A, Subar AF, Potischman N. Sugars and risk of mortality in the NIH-AARP Diet and Health Study. Am J Clin Nutr 2014; 99:1077-88. [PMID: 24552754 PMCID: PMC3985213 DOI: 10.3945/ajcn.113.069369] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Accepted: 01/29/2014] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Although previous studies have linked intake of sugars with incidence of cancer and other chronic diseases, its association with mortality remains unknown. OBJECTIVE We investigated the association of total sugars, added sugars, total fructose, added fructose, sucrose, and added sucrose with the risk of all-cause, cardiovascular disease, cancer, and other-cause mortality in the NIH-AARP Diet and Health Study. DESIGN The participants (n = 353,751), aged 50-71 y, were followed for up to 13 y. Intake of individual sugars over the previous 12 mo was assessed at baseline by using a 124-item NIH Diet History Questionnaire. RESULTS In fully adjusted models (fifth quartile compared with first quartile), all-cause mortality was positively associated with the intake of total sugars [HR (95% CI): 1.13 (1.06, 1.20); P-trend < 0.0001], total fructose [1.10 (1.04, 1.17); P-trend < 0.0001], and added fructose [1.07 (1.01, 1.13); P-trend = 0.005) in women and total fructose [1.06 (1.01, 1.10); P-trend = 0.002] in men. In men, a weak inverse association was found between other-cause mortality and dietary added sugars (P-trend = 0.04), sucrose (P-trend = 0.03), and added sucrose (P-trend = 0.006). Investigation of consumption of sugars by source showed that the positive association with mortality risk was confined only to sugars from beverages, whereas the inverse association was confined to sugars from solid foods. CONCLUSIONS In this large prospective study, total fructose intake was weakly positively associated with all-cause mortality in both women and men, whereas added sugar, sucrose, and added sucrose intakes were inversely associated with other-cause mortality in men. In our analyses, intake of added sugars was not associated with an increased risk of mortality. The NIH-AARP Diet and Health Study was registered at clinicaltrials.gov as NCT00340015.
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Affiliation(s)
- Natasha Tasevska
- Applied Research Program, Division of Cancer Control and Population Sciences, National Cancer Institute, NIH, Bethesda, MD (NT, AFS, and NP); the Nutrition Program, School of Nutrition and Health Promotion, Arizona State University, Phoenix, AZ (NT); the Nutritional Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, Bethesda, MD (YP and LJ); the Section of Gastroenterology and Hepatology, Department of Medicine, Baylor College of Medicine, Houston, TX (LJ); and the AARP, Washington, DC (AH)
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Wang C, Geng B, Cui Q, Guan Y, Yang J. Intracellular and extracellular adenosine triphosphate in regulation of insulin secretion from pancreatic β cells (β). J Diabetes 2014; 6:113-9. [PMID: 24134160 DOI: 10.1111/1753-0407.12098] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Revised: 09/27/2013] [Accepted: 10/11/2013] [Indexed: 01/09/2023] Open
Abstract
Adenosine triphosphate (ATP) synthesis and release in mitochondria play critical roles in regulating insulin secretion in pancreatic β cells. Mitochondrial dysfunction is mainly characterized by a decrease in ATP production, which is a central event in the progression of pancreatic β cell dysfunction and diabetes. ATP has been demonstrated to regulate insulin secretion via several pathways: (i) Intracellular ATP directly closes ATP-sensitive potassium channel to open L-type calcium channel, leading to an increase in free cytosolic calcium levels and exocytosis of insulin granules; (ii) A decrease in ATP production is always associated with an increase in production of reactive oxygen species, which exerts deleterious effects on pancreatic β cell survival and insulin secretion; and (iii) ATP can be co-secreted with insulin from pancreatic β cells, and the released ATP functions as an autocrine signal to modulate insulin secretory process via P2 receptors on the cell membrane. In this review, the recent findings regarding the role and mechanism of ATP synthesis and release in regulation of insulin secretion from pancreatic β cells will be summarized and discussed.
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Affiliation(s)
- Chunjiong Wang
- Department of Physiology and Pathophysiology, Tianjin Medical University, Tianjin, China
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Wong N, Morahan G, Stathopoulos M, Proietto J, Andrikopoulos S. A novel mechanism regulating insulin secretion involving Herpud1 in mice. Diabetologia 2013; 56:1569-76. [PMID: 23620059 DOI: 10.1007/s00125-013-2908-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2012] [Accepted: 03/18/2013] [Indexed: 11/24/2022]
Abstract
AIMS/HYPOTHESIS Type 2 diabetes results from beta cell dysfunction after prolonged physiological stress, which causes oversecretion of insulin. We recently found that insulin hypersecretion is mediated by at least two genes. Among mouse models of type 2 diabetes, the DBA/2 mouse strain is more susceptible to diabetes than is the C57BL/6J (B6J) strain. One distinctive feature of the DBA/2 mouse is that it hypersecretes insulin, independent of changes in insulin sensitivity; we identified Nnt as a gene responsible for this trait. METHODS To identify the other gene(s) affecting insulin hypersecretion, we tested a panel of recombinant inbred BXD strains, which have different combinations of B6 and DBA/2 alleles. RESULTS We found that 25% of the BXD strains hypersecreted insulin in response to glucose. Microarray profiling of islets from high- and low-secretor strains showed that at least four genes were differentially expressed. One gene was consistently underexpressed in islets from both DBA/2 and the high-secretor BXD strains. This gene (Herpud1 or Herp) encodes the 54 kDa endoplasmic reticulum stress-inducible protein (HERP) that resides in the integral endoplasmic reticulum membrane. To test directly whether Herpud1 can interact with Nnt, Herpud1 was either knocked down or overexpressed in MIN6 cells. These results showed that when Herpud1 was suppressed, Nnt expression was reduced, while overexpression of Herpud1 led to increased Nnt expression. Furthermore, Herpud1 suppression resulted in significantly decreased glucose-stimulated insulin secretion in the DBA/2 islets but not B6J islets. CONCLUSIONS/INTERPRETATION We conclude that Herpud1 regulates insulin secretion via control of Nnt expression.
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Affiliation(s)
- N Wong
- Department of Medicine (Austin Health), Austin Hospital, University of Melbourne, Heidelberg Heights, Melbourne, Victoria, 3084, Australia.
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Forbes JM, Cowan SP, Andrikopoulos S, Morley AL, Ward LC, Walker KZ, Cooper ME, Coughlan MT. Glucose homeostasis can be differentially modulated by varying individual components of a western diet. J Nutr Biochem 2013; 24:1251-7. [PMID: 23313044 DOI: 10.1016/j.jnutbio.2012.09.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2012] [Revised: 08/14/2012] [Accepted: 09/21/2012] [Indexed: 01/19/2023]
Abstract
Chronic overconsumption of a Western diet has been identified as a major risk factor for diabetes, yet precisely how each individual component contributes to defects in glucose homeostasis independent of consumption of other macronutrients remains unclear. Eight-week-old male Sprague Dawley rats were randomized to feeding with one of six semi-pure diets: control, processed (high advanced glycation end products/AGE), high protein, high dextrose (glucose polymer), high in saturated fat (plant origin), or high in saturated fat (animal origin). After chronic feeding for 24 weeks, body composition was determined by bioelectrical impedance spectroscopy and glucose homeostasis was assessed. When compared to the control and high AGE diets, excess consumption of the diet high in saturated fat (animal source) increased body weight and adiposity, and decreased insulin sensitivity, as defined by HOMA IR, impaired skeletal muscle insulin signaling and insulin hypersecretion in the context of increased circulating glucagon-like peptide (GLP-1). Compared to the control diet, chronic consumption of the high AGE, protein or dextrose diet increased fasting plasma glucose, decreased fasting plasma insulin and insulin secretion. These diets also reduced circulating GLP-1 concentrations. These data suggest that individual components of a western diet have differential effects in modulating glucose homeostasis and adiposity. These data provide clear evidence of a link between over-consumption of a western diet and the development of diabetes.
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Affiliation(s)
- Josephine M Forbes
- Diabetes Complications, Baker IDI Heart and Diabetes Research Institute, Melbourne, Victoria, Australia
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Abstract
Liver fructose-1,6-bisphosphatase (FBPase) is a regulatory enzyme in gluconeogenesis that is elevated by obesity and dietary fat intake. Whether FBPase functions only in glucose metabolism or has other metabolic roles is currently unclear. In our recently published study, we examined the importance of liver FBPase in body weight regulation by performing a series of comprehensive physiological and biochemical assessments of energy balance and specific intervention studies in our transgenic mouse line that overexpresses FBPase specifically in the liver. Compared with negative littermates, these FBPase transgenic mice weighed 10% less, had 50% less adiposity, ate 15% less food but did not have altered energy expenditure. Increased circulating leptin and cholecystokinin levels, elevated fatty acid oxidation and reduced appetite stimulating neuropeptides, neuropeptide Y (NPY) and agouti-related peptide (AGRP), underpinned this phenotype. Blocking the action of FBPase returned food intake and body weight to those of the negative littermates. Our study is the first to identify liver FBPase as a previously unknown regulator of appetite and adiposity. Importantly, this work recognizes the liver as an important organ in appetite and body weight regulation. This commentary will provide further insight and expand on this novel concept that the liver does in fact play an important role in adiposity.
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Fam BC, Rose LJ, Sgambellone R, Ruan Z, Proietto J, Andrikopoulos S. Normal muscle glucose uptake in mice deficient in muscle GLUT4. J Endocrinol 2012; 214:313-27. [PMID: 22736482 DOI: 10.1530/joe-12-0032] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Skeletal muscle insulin resistance is a major characteristic underpinning type 2 diabetes. Impairments in the insulin responsiveness of the glucose transporter, Glut4 (Slc2a4), have been suggested to be a contributing factor to this disturbance. We have produced muscle-specific Glut4 knockout (KO) mice using Cre/LoxP technology on a C57BL6/J background and shown undetectable levels of GLUT4 in both skeletal muscle and heart. Our aim was to determine whether complete deletion of muscle GLUT4 does in fact lead to perturbations in glucose homoeostasis. Glucose tolerance, glucose turnover and 2-deoxyglucose uptake into muscle and fat under basal and insulin-stimulated conditions were assessed in 12-week-old KO and control mice using the oral glucose tolerance test (OGTT) and hyperinsulinaemic/euglycaemic clamp respectively. KO mice weighed ~17% less and had significantly heavier hearts compared with control mice. Basally, plasma glucose and plasma insulin were significantly lower in the KO compared with control mice, which conferred normal glucose tolerance. Despite the lack of GLUT4 in the KO mouse muscle, glucose uptake was not impaired in skeletal muscle but was reduced in heart under insulin-stimulated conditions. Neither GLUT1 nor GLUT12 protein levels were altered in the skeletal muscle or heart tissue of our KO mice. High-fat feeding did not alter glucose tolerance in the KO mice but led to elevated plasma insulin levels during the glucose tolerance test. Our study demonstrates that deletion of muscle GLUT4 does not adversely affect glucose disposal and glucose tolerance and that compensation from other transporters may contribute to this unaltered homoeostasis of glucose.
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Affiliation(s)
- Barbara C Fam
- Department of Medicine (Austin Health), Austin Hospital, University of Melbourne, Heidelberg, Victoria 3084, Australia.
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Carreras A, Kayali F, Zhang J, Hirotsu C, Wang Y, Gozal D. Metabolic effects of intermittent hypoxia in mice: steady versus high-frequency applied hypoxia daily during the rest period. Am J Physiol Regul Integr Comp Physiol 2012; 303:R700-9. [PMID: 22895743 DOI: 10.1152/ajpregu.00258.2012] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Intermittent hypoxia (IH) is a frequent occurrence in sleep and respiratory disorders. Both human and murine studies show that IH may be implicated in metabolic dysfunction. Although the effects of nocturnal low-frequency intermittent hypoxia (IH(L)) have not been extensively examined, it would appear that IH(L) and high-frequency intermittent hypoxia (IH(H)) may elicit distinct metabolic adaptations. To this effect, C57BL/6J mice were randomly assigned to IH(H) (cycles of 90 s 6.4% O(2) and 90 s 21% O(2) during daylight), IH(L) (8% O(2) during daylight hours), or control (CTL) for 5 wk. At the end of exposures, some of the mice were subjected to a glucose tolerance test (GTT; after intraperitoneal injection of 2 mg glucose/g body wt), and others were subjected to an insulin tolerance test (ITT; 0.25 units Humulin/kg body wt), with plasma leptin and insulin levels being measured in fasting conditions. Skeletal muscles were harvested for GLUT4 and proliferator-activated receptor gamma coactivator 1-α (PGC1-α) expression. Both IH(H) and IH(L) displayed reduced body weight increases compared with CTL. CTL mice had higher basal glycemic levels, but GTT kinetics revealed marked differences between IH(L) and IH(H), with IH(L) manifesting the lowest insulin sensitivity compared with either IH(H) or CTL, and such findings were further confirmed by ITT. No differences emerged in PGC1-α expression across the three experimental groups. However, while cytosolic GLUT4 protein expression remained similar in IH(L), IH(H), and CTL, significant decreases in GLUT4 membrane fraction occurred in hypoxia and were most pronounced in IH(L)-exposed mice. Thus IH(H) and IH(L) elicit differential glucose homeostatic responses despite similar cumulative hypoxic profiles.
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Affiliation(s)
- Alba Carreras
- Dept. of Pediatrics, Univ. of Chicago, Chicago, IL 60637, USA
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Stokes RA, Cheng K, Deters N, Lau SM, Hawthorne WJ, O'Connell PJ, Stolp J, Grey S, Loudovaris T, Kay TW, Thomas HE, Gonzalez FJ, Gunton JE. Hypoxia-inducible factor-1α (HIF-1α) potentiates β-cell survival after islet transplantation of human and mouse islets. Cell Transplant 2012; 22:253-66. [PMID: 22710383 DOI: 10.3727/096368912x647180] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
A high proportion of β-cells die within days of islet transplantation. Reports suggest that induction of hypoxia-inducible factor-1α (HIF-1α) predicts adverse transplant outcomes. We hypothesized that this was a compensatory response and that HIF-1α protects β-cells during transplantation. Transplants were performed using human islets or murine β-cell-specific HIF-1α-null (β-HIF-1α-null) islets with or without treatment with deferoxamine (DFO) to increase HIF-1α. β-HIF-1α-null transplants had poor outcomes, demonstrating that lack of HIF-1α impaired transplant efficiency. Increasing HIF-1α improved outcomes for mouse and human islets. No effect was seen in β-HIF-1α-null islets. The mechanism was decreased apoptosis, resulting in increased β-cell mass posttransplantation. These findings show that HIF-1α is a protective factor and is required for successful islet transplant outcomes. Iron chelation with DFO markedly improved transplant success in a HIF-1α-dependent manner, thus demonstrating the mechanism of action. DFO, approved for human use, may have a therapeutic role in the setting of human islet transplantation.
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Affiliation(s)
- Rebecca A Stokes
- Diabetes and Transcription Factors Group, Garvan Institute of Medical Research GIMR, Sydney NSW 2010, Australia
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Zhang Y, Xie Z, Zhou L, Li L, Zhang H, Zhou G, Ma X, Herrera PL, Liu Z, Grusby MJ, Zhang WJ. The zinc finger protein ZBTB20 regulates transcription of fructose-1,6-bisphosphatase 1 and β cell function in mice. Gastroenterology 2012; 142:1571-1580.e6. [PMID: 22374165 DOI: 10.1053/j.gastro.2012.02.043] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2011] [Revised: 01/31/2012] [Accepted: 02/22/2012] [Indexed: 12/16/2022]
Abstract
BACKGROUND & AIMS Fructose-1,6-bisphosphatase (FBP)-1 is a gluconeogenic enzyme that regulates glucose metabolism and insulin secretion in β cells, but little is known about how its transcription is controlled. The zinc finger protein ZBTB20 regulates glucose homeostasis, so we investigated its effects on expression of FBP-1. METHODS We analyzed gene expression using real-time reverse-transcription polymerase chain reaction, immunoblotting, and immunohistochemistry. We generated mice with β cell-specific disruption of Zbtb20 using Cre/LoxP technology. Expression of Zbtb20 in β cells was reduced using small interfering RNAs, and promoter occupancy and transcriptional regulation were analyzed by chromatin immunoprecipitation and reporter assays. RESULTS ZBTB20 was expressed at high levels by β cells and other endocrine cells in islets of normal mice; expression levels were reduced in islets from diabetic db/db mice. Mice with β cell-specific knockout of Zbtb20 had normal development of β cells but had hyperglycemia, hypoinsulinemia, glucose intolerance, and impaired glucose-stimulated insulin secretion. Islets isolated from these mice had impaired glucose metabolism, adenosine triphosphate production, and insulin secretion after glucose stimulation in vitro, although insulin secretion returned to normal levels in the presence of KCl. ZBTB20 knockdown with small interfering RNAs impaired glucose-stimulated insulin secretion in the β cell line MIN6. Expression of Fbp1 was up-regulated in β cells with ZBTB20 knockout or knockdown; impairments to glucose-stimulated insulin secretion were restored by inhibition of FBPase activity. ZBTB20 was recruited to the Fbp1 promoter and repressed its transcription in β cells. CONCLUSIONS The transcription factor ZBTB20 regulates β cell function and glucose homeostasis in mice. It might be a therapeutic target for type 2 diabetes mellitus.
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Affiliation(s)
- Ye Zhang
- Department of Pathophysiology, Second Military Medical University, Shanghai, China
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Visinoni S, Khalid NFI, Joannides CN, Shulkes A, Yim M, Whitehead J, Tiganis T, Lamont BJ, Favaloro JM, Proietto J, Andrikopoulos S, Fam BC. The role of liver fructose-1,6-bisphosphatase in regulating appetite and adiposity. Diabetes 2012; 61:1122-32. [PMID: 22517657 PMCID: PMC3331739 DOI: 10.2337/db11-1511] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Liver fructose-1,6-bisphosphatase (FBPase) is a regulatory enzyme in gluconeogenesis that is elevated by obesity and dietary fat intake. Whether FBPase functions only to regulate glucose or has other metabolic consequences is not clear; therefore, the aim of this study was to determine the importance of liver FBPase in body weight regulation. To this end we performed comprehensive physiologic and biochemical assessments of energy balance in liver-specific transgenic FBPase mice and negative control littermates of both sexes. In addition, hepatic branch vagotomies and pharmacologic inhibition studies were performed to confirm the role of FBPase. Compared with negative littermates, liver-specific FBPase transgenic mice had 50% less adiposity and ate 15% less food but did not have altered energy expenditure. The reduced food consumption was associated with increased circulating leptin and cholecystokinin, elevated fatty acid oxidation, and 3-β-hydroxybutyrate ketone levels, and reduced appetite-stimulating neuropeptides, neuropeptide Y and Agouti-related peptide. Hepatic branch vagotomy and direct pharmacologic inhibition of FBPase in transgenic mice both returned food intake and body weight to the negative littermates. This is the first study to identify liver FBPase as a previously unknown regulator of appetite and adiposity and describes a novel process by which the liver participates in body weight regulation.
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Affiliation(s)
- Sherley Visinoni
- Department of Medicine, University of Melbourne, Heidelberg, Victoria, Australia
| | | | | | - Arthur Shulkes
- Department of Surgery, Austin Health, University of Melbourne, Heidelberg, Victoria, Australia
| | - Mildred Yim
- Department of Surgery, Austin Health, University of Melbourne, Heidelberg, Victoria, Australia
| | - Jon Whitehead
- Mater Medical Research Institute, Brisbane, Queensland, Australia
| | - Tony Tiganis
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
| | - Benjamin J. Lamont
- Department of Medicine, University of Melbourne, Heidelberg, Victoria, Australia
| | - Jenny M. Favaloro
- Department of Medicine, University of Melbourne, Heidelberg, Victoria, Australia
| | - Joseph Proietto
- Department of Medicine, University of Melbourne, Heidelberg, Victoria, Australia
| | | | - Barbara C. Fam
- Department of Medicine, University of Melbourne, Heidelberg, Victoria, Australia
- Corresponding author: Barbara C. Fam,
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Volkmar M, Dedeurwaerder S, Cunha DA, Ndlovu MN, Defrance M, Deplus R, Calonne E, Volkmar U, Igoillo-Esteve M, Naamane N, Del Guerra S, Masini M, Bugliani M, Marchetti P, Cnop M, Eizirik DL, Fuks F. DNA methylation profiling identifies epigenetic dysregulation in pancreatic islets from type 2 diabetic patients. EMBO J 2012; 31:1405-26. [PMID: 22293752 PMCID: PMC3321176 DOI: 10.1038/emboj.2011.503] [Citation(s) in RCA: 289] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Accepted: 12/12/2011] [Indexed: 12/17/2022] Open
Abstract
In addition to genetic predisposition, environmental and lifestyle factors contribute to the pathogenesis of type 2 diabetes (T2D). Epigenetic changes may provide the link for translating environmental exposures into pathological mechanisms. In this study, we performed the first comprehensive DNA methylation profiling in pancreatic islets from T2D and non-diabetic donors. We uncovered 276 CpG loci affiliated to promoters of 254 genes displaying significant differential DNA methylation in diabetic islets. These methylation changes were not present in blood cells from T2D individuals nor were they experimentally induced in non-diabetic islets by exposure to high glucose. For a subgroup of the differentially methylated genes, concordant transcriptional changes were present. Functional annotation of the aberrantly methylated genes and RNAi experiments highlighted pathways implicated in β-cell survival and function; some are implicated in cellular dysfunction while others facilitate adaptation to stressors. Together, our findings offer new insights into the intricate mechanisms of T2D pathogenesis, underscore the important involvement of epigenetic dysregulation in diabetic islets and may advance our understanding of T2D aetiology.
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Affiliation(s)
- Michael Volkmar
- Laboratory of Cancer Epigenetics, Faculty of Medicine, Université Libre de Bruxelles, Brussels, Belgium
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Sellamuthu PS, Arulselvan P, Muniappan BP, Kandasamy M. Effect of mangiferin isolated from Salacia chinensis regulates the kidney carbohydrate metabolism in streptozotocin–induced diabetic rats. Asian Pac J Trop Biomed 2012. [DOI: 10.1016/s2221-1691(12)60457-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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Coughlan MT, Yap FY, Tong DC, Andrikopoulos S, Gasser A, Thallas-Bonke V, Webster DE, Miyazaki JI, Kay TW, Slattery RM, Kaye DM, Drew BG, Kingwell BA, Fourlanos S, Groop PH, Harrison LC, Knip M, Forbes JM. Advanced glycation end products are direct modulators of β-cell function. Diabetes 2011; 60:2523-32. [PMID: 21911745 PMCID: PMC3178291 DOI: 10.2337/db10-1033] [Citation(s) in RCA: 122] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
OBJECTIVE Excess accumulation of advanced glycation end products (AGEs) contributes to aging and chronic diseases. We aimed to obtain evidence that exposure to AGEs plays a role in the development of type 1 diabetes (T1D). RESEARCH DESIGN AND METHODS The effect of AGEs was examined on insulin secretion by MIN6N8 cells and mouse islets and in vivo in three separate rodent models: AGE-injected or high AGE-fed Sprague-Dawley rats and nonobese diabetic (NODLt) mice. Rodents were also treated with the AGE-lowering agent alagebrium. RESULTS β-Cells exposed to AGEs displayed acute glucose-stimulated insulin secretory defects, mitochondrial abnormalities including excess superoxide generation, a decline in ATP content, loss of MnSOD activity, reduced calcium flux, and increased glucose uptake, all of which were improved with alagebrium treatment or with MnSOD adenoviral overexpression. Isolated mouse islets exposed to AGEs had decreased glucose-stimulated insulin secretion, increased mitochondrial superoxide production, and depletion of ATP content, which were improved with alagebrium or with MnTBAP, an SOD mimetic. In rats, transient or chronic exposure to AGEs caused progressive insulin secretory defects, superoxide generation, and β-cell death, ameliorated with alagebrium. NODLt mice had increased circulating AGEs in association with an increase in islet mitochondrial superoxide generation, which was prevented by alagebrium, which also reduced the incidence of autoimmune diabetes. Finally, at-risk children who progressed to T1D had higher AGE concentrations than matched nonprogressors. CONCLUSIONS These findings demonstrate that AGEs directly cause insulin secretory defects, most likely by impairing mitochondrial function, which may contribute to the development of T1D.
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Affiliation(s)
- Melinda T. Coughlan
- Division of Diabetes Complications, Diabetes and Metabolism Division, Baker IDI Heart and Diabetes Institute, Melbourne, Australia
| | - Felicia Y.T. Yap
- Division of Diabetes Complications, Diabetes and Metabolism Division, Baker IDI Heart and Diabetes Institute, Melbourne, Australia
| | - David C.K. Tong
- Division of Diabetes Complications, Diabetes and Metabolism Division, Baker IDI Heart and Diabetes Institute, Melbourne, Australia
| | - Sofianos Andrikopoulos
- Department of Medicine, (AH/NH) University of Melbourne, Heidelberg Repatriation Hospital, Heidelberg Heights, Australia
| | - Anna Gasser
- Division of Diabetes Complications, Diabetes and Metabolism Division, Baker IDI Heart and Diabetes Institute, Melbourne, Australia
| | - Vicki Thallas-Bonke
- Division of Diabetes Complications, Diabetes and Metabolism Division, Baker IDI Heart and Diabetes Institute, Melbourne, Australia
| | - Diane E. Webster
- Department of Immunology and Medicine, Monash University, Melbourne, Australia
| | - Jun-ichi Miyazaki
- Division of Stem Cell Regulation Research, Osaka University Medical School, Osaka, Japan
| | | | - Robyn M. Slattery
- Department of Immunology and Medicine, Monash University, Melbourne, Australia
| | - David M. Kaye
- Heart Failure Research Group, Baker IDI Heart and Diabetes Institute, Melbourne, Australia
| | - Brian G. Drew
- Clinical Physiology, Baker IDI Heart and Diabetes Institute, Melbourne, Australia
| | - Bronwyn A. Kingwell
- Clinical Physiology, Baker IDI Heart and Diabetes Institute, Melbourne, Australia
| | - Spiros Fourlanos
- Division of Autoimmunity and Transplantation, Walter and Eliza Hall Institute, Parkville, Australia
| | - Per-Henrik Groop
- Department of Diabetes Genetics, Folkhälsan Institute of Genetics, Folkhälsan Research Center, Biomedicum, University of Helsinki, Helsinki, Finland
- Department of Medicine, Division of Nephrology, Helsinki University Central Hospital, Helsinki, Finland
| | - Leonard C. Harrison
- Division of Autoimmunity and Transplantation, Walter and Eliza Hall Institute, Parkville, Australia
| | - Mikael Knip
- Department of Diabetes Genetics, Folkhälsan Institute of Genetics, Folkhälsan Research Center, Biomedicum, University of Helsinki, Helsinki, Finland
- Hospital for Children and Adolescents, University of Helsinki, Finland
| | - Josephine M. Forbes
- Division of Diabetes Complications, Diabetes and Metabolism Division, Baker IDI Heart and Diabetes Institute, Melbourne, Australia
- Department of Immunology and Medicine, Monash University, Melbourne, Australia
- Mater Medical Research Institute, South Brisbane, Queensland, Australia
- Corresponding author: Josephine M. Forbes,
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Mangiafico SP, Lim SH, Neoh S, Massinet H, Joannides CN, Proietto J, Andrikopoulos S, Fam BC. A primary defect in glucose production alone cannot induce glucose intolerance without defects in insulin secretion. J Endocrinol 2011; 210:335-47. [PMID: 21700659 DOI: 10.1530/joe-11-0126] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Increased glucose production is associated with fasting hyperglycaemia in type 2 diabetes but whether or not it causes glucose intolerance is unclear. This study sought to determine whether a primary defect in gluconeogenesis (GNG) resulting in elevated glucose production is sufficient to induce glucose intolerance in the absence of insulin resistance and impaired insulin secretion. Progression of glucose intolerance was assessed in phosphoenolpyruvate carboxykinase (PEPCK) transgenic rats, a genetic model with a primary increase in GNG. Young (4-5 weeks of age) and adult (12-14 weeks of age) PEPCK transgenic and Piebald Virol Glaxo (PVG/c) control rats were studied. GNG, insulin sensitivity, insulin secretion and glucose tolerance were assessed by intraperitoneal and intravascular substrate tolerance tests and hyperinsulinaemic/euglycaemic clamps. Despite elevated GNG and increased glucose appearance, PEPCK transgenic rats displayed normal glucose tolerance due to adequate glucose disposal and robust glucose-mediated insulin secretion. Glucose intolerance only became apparent in the PEPCK transgenic rats following the development of insulin resistance (both hepatic and peripheral) and defective glucose-mediated insulin secretion. Taken together, a single genetic defect in GNG leading to increased glucose production does not adversely affect glucose tolerance. Insulin resistance and impaired glucose-mediated insulin secretion are required to precipitate glucose intolerance in a setting of chronic glucose oversupply.
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Affiliation(s)
- Salvatore P Mangiafico
- Department of Medicine, Heidelberg Repatriation Hospital, University of Melbourne, 300 Waterdale Road, Heidelberg Heights, Melbourne, Victoria 3081, Australia
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40
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Molecular modeling studies on phosphonic acid-containing thiazole derivatives: design for fructose-1,6-bisphosphatase inhibitors. J Mol Model 2011; 18:973-90. [DOI: 10.1007/s00894-011-1134-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2011] [Accepted: 05/18/2011] [Indexed: 10/18/2022]
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41
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Forbes JM, Söderlund J, Yap FYT, Knip M, Andrikopoulos S, Ilonen J, Simell O, Veijola R, Sourris KC, Coughlan MT, Forsblom C, Slattery R, Grey ST, Wessman M, Yamamoto H, Bierhaus A, Cooper ME, Groop PH. Receptor for advanced glycation end-products (RAGE) provides a link between genetic susceptibility and environmental factors in type 1 diabetes. Diabetologia 2011; 54:1032-42. [PMID: 21298413 DOI: 10.1007/s00125-011-2058-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2010] [Accepted: 12/14/2010] [Indexed: 01/31/2023]
Abstract
AIMS/HYPOTHESIS This group of studies examines human genetic susceptibility conferred by the receptor for advanced glycation end-products (RAGE) in type 1 diabetes and investigates how this may interact with a western environment. METHODS We analysed the AGER gene, using 13 tag SNPs, in 3,624 Finnish individuals from the FinnDiane study, followed by AGER associations with a high risk HLA genotype (DR3)-DQA1*05-DQB1*02/DRB1*0401-DQB1*0302 (n = 546; HLA-DR3/DR4), matched in healthy newborn infants from the Finnish Type 1 Diabetes Prediction and Prevention (DIPP) Study (n = 373) using allelic analysis. We also studied islets and circulating RAGE in NODLt mice. RESULTS The rs2070600 and rs17493811 polymorphisms predicted increased risk of type 1 diabetes, whereas the rs9469089 SNP was related to decreased risk, on a high risk HLA background. Children from the DIPP study also showed a decline in circulating soluble RAGE levels, at seroconversion to positivity for type 1 diabetes-associated autoantibodies. Islet RAGE and circulating soluble RAGE levels in prediabetic NODLt mice decreased over time and were prevented by the AGE lowering therapy alagebrium chloride. Alagebrium chloride also decreased the incidence of autoimmune diabetes and restored islet RAGE levels. CONCLUSIONS/INTERPRETATION These studies suggest that inherited AGER gene polymorphisms may confer susceptibility to environmental insults. Declining circulating levels of soluble RAGE, before the development of overt diabetes, may also be predictive of clinical disease in children with high to medium risk HLA II backgrounds and this possibility warrants further investigation in a larger cohort.
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Affiliation(s)
- J M Forbes
- Diabetes Complications Division, Baker IDI Heart and Diabetes Institute, St Kilda Rd Central, P.O. Box 6492, Melbourne, VIC 8008, Australia.
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42
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Zhang Y, Xie Z, Zhou G, Zhang H, Lu J, Zhang WJ. Fructose-1,6-bisphosphatase regulates glucose-stimulated insulin secretion of mouse pancreatic beta-cells. Endocrinology 2010; 151:4688-95. [PMID: 20719858 DOI: 10.1210/en.2009-1185] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Pancreatic β-cells can precisely sense glucose stimulation and accordingly adjust their insulin secretion. Fructose-1,6-bisphosphatase (FBPase) is a gluconeogenic enzyme, but its physiological significance in β-cells is not established. Here we determined its physiological role in regulating glucose sensing and insulin secretion of β-cells. Considerable FBPase mRNA was detected in normal mouse islets and β-cell lines, although their protein levels appeared to be quite low. Down-regulation of FBP1 in MIN6 cells by small interfering RNA could enhance the glucose-stimulated insulin secretion (GSIS), whereas FBP1-overexpressing MIN6 cells exhibited decreased GSIS. Inhibition of FBPase activity in islet β-cells by its specific inhibitor MB05032 led to significant increase of their glucose utilization and cellular ATP to ADP ratios and consequently enhanced GSIS in vitro. Pretreatment of mice with the MB05032 prodrug MB06322 could potentiate GSIS in vivo and improve their glucose tolerance. Therefore, FBPase plays an important role in regulating glucose sensing and insulin secretion of β-cells and serves a promising target for diabetes treatment.
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Affiliation(s)
- Ye Zhang
- Center for Obesity & Diabetes Research and Innovation, Department of Pathophysiology, Second Military Medical University, 800 Xiangyin Road, Shanghai 200433, China
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Andrikopoulos S. Obesity and type 2 diabetes: slow down!--Can metabolic deceleration protect the islet beta cell from excess nutrient-induced damage? Mol Cell Endocrinol 2010; 316:140-6. [PMID: 19815054 DOI: 10.1016/j.mce.2009.09.031] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2009] [Revised: 09/08/2009] [Accepted: 09/28/2009] [Indexed: 01/09/2023]
Abstract
Islet beta-cell dysfunction is a characteristic and the main cause of hyperglycaemia of Type 2 diabetes. Understanding the mechanisms that cause beta-cell dysfunction will lead to better therapeutic outcomes for patients with Type 2 diabetes. Chronic fatty acid exposure of susceptible islet beta-cells causes dysfunction and death and this is associated with increased reactive oxygen species production leading to oxidative stress and increased endoplasmic reticulum stress. We present the hypothesis that metabolic deceleration can reduce both oxidative and endoplasmic reticulum stress and lead to improved beta-cell function and viability when exposed to a deleterious fat milieu. This is illustrated by the C57BL/6J mouse which is characterised by reduced insulin secretion and glucose intolerance associated with a mutation in nicotinamide nucleotide transhydrogenase (Nnt) but is resistant to obesity induced diabetes. On the other hand the DBA/2 mouse has comparatively higher insulin secretion and better glucose tolerance associated with increased Nnt activity but is susceptible to obesity-induced diabetes, possibly as a result of increased oxidative stress. We therefore suggest that in states of excess nutrient load, a reduced ability to metabolise this load may protect both the function and viability of beta-cells. Strategies that reduce metabolic flux when beta-cells are exposed to nutrient excess need to be considered when treating Type 2 diabetes.
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Affiliation(s)
- S Andrikopoulos
- Department of Medicine (AH/NH), University of Melbourne, Heidelberg Repatriation Hospital, Heidelberg Heights, Victoria, Australia.
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Wong N, Blair AR, Morahan G, Andrikopoulos S. The deletion variant of nicotinamide nucleotide transhydrogenase (Nnt) does not affect insulin secretion or glucose tolerance. Endocrinology 2010; 151:96-102. [PMID: 19906813 DOI: 10.1210/en.2009-0887] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The C57BL/6J (B6J) strain is the most widely used mouse strain in metabolic research. B6J mice produce a truncated form of nicotinamide nucleotide transhydrogenase (NNT), an enzyme that pumps protons across the inner mitochondrial membrane. It has been proposed that this results in B6J mice having reduced insulin secretion and glucose intolerance compared with other strains of mice (e.g. C3H/HeH and DBA/2) that have a full-length NNT. The aim of this study was to determine whether truncated NNT was associated with reduced insulin secretion and glucose intolerance, comparing B6 substrains that differ in having a truncated NNT. C57BL/6N (B6N) mice have wild-type Nnt. We compared Nnt expression and activity levels as well as in vivo insulin secretion and glucose tolerance between these mice and B6J. Body weights and specific fat-pad depot masses were alike and Nnt expression and activity levels were similar between B6N and B6J mice. Glucose-mediated insulin secretion and insulin sensitivity were comparable between the two groups of mice, as were plasma glucose and insulin levels during the oral glucose tolerance test. The presence of a truncated Nnt did not affect insulin secretion or glucose tolerance on the C57BL/6 background. We suggest that low or normal levels of NNT (regardless of truncation) have little effect on insulin secretion. Rather, it is the increase in expression of Nnt that regulates and enhances insulin secretion. Our data confirm that B6J is a reasonable control strain for diabetes research; this is especially important considering that it is the strain commonly used to generate genetically modified animals.
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Affiliation(s)
- Nicole Wong
- University of Melbourne, Department of Medicine, Heidelberg Repatriation Hospital, Heidelberg Heights, Victoria 3081, Australia
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Stark R, Pasquel F, Turcu A, Pongratz RL, Roden M, Cline GW, Shulman GI, Kibbey RG. Phosphoenolpyruvate cycling via mitochondrial phosphoenolpyruvate carboxykinase links anaplerosis and mitochondrial GTP with insulin secretion. J Biol Chem 2009; 284:26578-90. [PMID: 19635791 PMCID: PMC2785346 DOI: 10.1074/jbc.m109.011775] [Citation(s) in RCA: 118] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2009] [Revised: 07/15/2009] [Indexed: 11/13/2022] Open
Abstract
Pancreatic beta-cells couple the oxidation of glucose to the secretion of insulin. Apart from the canonical K(ATP)-dependent glucose-stimulated insulin secretion (GSIS), there are important K(ATP)-independent mechanisms involving both anaplerosis and mitochondrial GTP (mtGTP). How mtGTP that is trapped within the mitochondrial matrix regulates the cytosolic calcium increases that drive GSIS remains a mystery. Here we have investigated whether the mitochondrial isoform of phosphoenolpyruvate carboxykinase (PEPCK-M) is the GTPase linking hydrolysis of mtGTP made by succinyl-CoA synthetase (SCS-GTP) to an anaplerotic pathway producing phosphoenolpyruvate (PEP). Although cytosolic PEPCK (PEPCK-C) is absent, PEPCK-M message and protein were detected in INS-1 832/13 cells, rat islets, and mouse islets. PEPCK enzymatic activity is half that of primary hepatocytes and is localized exclusively to the mitochondria. Novel (13)C-labeling strategies in INS-1 832/13 cells and islets measured substantial contribution of PEPCK-M to the synthesis of PEP. As high as 30% of PEP in INS-1 832/13 cells and 41% of PEP in rat islets came from PEPCK-M. The contribution of PEPCK-M to overall PEP synthesis more than tripled with glucose stimulation. Silencing the PEPCK-M gene completely inhibited GSIS underscoring its central role in mitochondrial metabolism-mediated insulin secretion. Given that mtGTP synthesized by SCS-GTP is an indicator of TCA flux that is crucial for GSIS, PEPCK-M is a strong candidate to link mtGTP synthesis with insulin release through anaplerotic PEP cycling.
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Affiliation(s)
| | | | - Adina Turcu
- From the Departments of Internal Medicine and
| | | | - Michael Roden
- the Institute for Clinical Diabetology, German Diabetes Center, 40225 Düsseldorf, Germany
| | | | - Gerald I. Shulman
- From the Departments of Internal Medicine and
- Cellular and Molecular Physiology and
- the Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, Connecticut 06520 and
| | - Richard G. Kibbey
- From the Departments of Internal Medicine and
- Cellular and Molecular Physiology and
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Andrikopoulos S, Blair AR, Deluca N, Fam BC, Proietto J. Evaluating the glucose tolerance test in mice. Am J Physiol Endocrinol Metab 2008; 295:E1323-32. [PMID: 18812462 DOI: 10.1152/ajpendo.90617.2008] [Citation(s) in RCA: 564] [Impact Index Per Article: 35.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The objective of this study was to determine the optimal conditions under which to assess glucose tolerance in chow- and high-fat-fed C57BL/6J mice. Mice were fed either chow or high-fat diet for 8 wk. Variables tested were fasting duration (0-, 3-, 6-, and 24-h and overnight fasting), route of administration (intraperitoneal vs. oral) load of glucose given (2, 1, or 0.5 g/kg and fixed 50-mg dose), and state of consciousness. Basal glucose concentrations were increased in high-fat- compared with chow-fed mice following 6 h of fasting (9.1 +/- 0.3 vs. 7.9 +/- 0.4 mmol/l P = 0.01). Glucose tolerance was most different and therefore significant (P = 0.001) in high-fat-fed mice after 6 h of fasting (1,973 +/- 96 vs. 1,248 +/- 83 mmol.l(-1).120 min(-1)). The difference in glucose tolerance was greater following an OGTT (142%), in contrast to an IPGTT, with a 127% difference between high fat and chow. We also found that administering 2 g/kg of glucose resulted in a greater level of significance (P = 0.0008) in glucose intolerance in high-fat- compared with chow-fed mice. A fixed dose of 50 mg glucose regardless of body weight was enough to show glucose intolerance in high-fat- vs. chow-fed mice. Finally, high-fat-fed mice showed glucose intolerance compared with their chow-fed counterparts whether they were tested under conscious or anesthetized conditions. We conclude that 2 g/kg glucose administered orally following 6 h of fasting is best to assess glucose tolerance in mice under these conditions.
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