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Xu H, Yong L, Gao X, Chen Y, Wang Y, Wang F, Hou X. CaMK4: Structure, physiological functions, and therapeutic potential. Biochem Pharmacol 2024; 224:116204. [PMID: 38615920 DOI: 10.1016/j.bcp.2024.116204] [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: 12/05/2023] [Revised: 03/22/2024] [Accepted: 04/11/2024] [Indexed: 04/16/2024]
Abstract
Calcium/calmodulin-dependent protein kinase IV (CaMK4) is a versatile serine/threonine kinase involved in various cellular functions. It regulates T-cell differentiation, podocyte function, tumor cell proliferation/apoptosis, β cell mass, and insulin sensitivity. However, the underlying molecular mechanisms are complex and remain incompletely understood. The aims of this review are to highlight the latest advances in the regulatory mechanisms of CaMK4 underlying T-cell imbalance and parenchymal cell mass in multiple diseases. The structural motifs and activation of CaMK4, as well as the potential role of CaMK4 as a novel therapeutic target are also discussed.
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Affiliation(s)
- Hao Xu
- Health Science Center, Ningbo University, Ningbo, Zhejiang 315211, PR China
| | - Liang Yong
- The First Affiliated Hospital of Ningbo University, Ningbo, Zhejiang 315010, PR China
| | - Xianxian Gao
- Health Science Center, Ningbo University, Ningbo, Zhejiang 315211, PR China
| | - Yandong Chen
- Health Science Center, Ningbo University, Ningbo, Zhejiang 315211, PR China
| | - Yixuan Wang
- Health Science Center, Ningbo University, Ningbo, Zhejiang 315211, PR China
| | - Fuyan Wang
- Health Science Center, Ningbo University, Ningbo, Zhejiang 315211, PR China; Clinical Laboratory, Qingdao Hiser Hospital Affiliated of Qingdao University (Qingdao Traditional Chinese Medicine Hospital), Qingdao, Shandong 266033, PR China
| | - Xin Hou
- Health Science Center, Ningbo University, Ningbo, Zhejiang 315211, PR China.
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2
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Cheng A, Xu Q, Li B, Zhang L, Wang H, Liu C, Han Z, Feng Z. The enhanced energy metabolism in the tumor margin mediated by RRAD promotes the progression of oral squamous cell carcinoma. Cell Death Dis 2024; 15:376. [PMID: 38811531 DOI: 10.1038/s41419-024-06759-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 05/13/2024] [Accepted: 05/17/2024] [Indexed: 05/31/2024]
Abstract
The tumor margin as the invasive front has been proven to be closely related to the progression and metastasis of oral squamous cell carcinoma (OSCC). However, how tumor cells in the marginal region obtain the extra energy needed for tumor progression is still unknown. Here, we used spatial metabolomics and the spatial transcriptome to identify enhanced energy metabolism in the tumor margin of OSCC and identified that the downregulation of Ras-related glycolysis inhibitor and calcium channel regulator (RRAD) in tumor cells mediated this process. The absence of RRAD enhanced the ingestion of glucose and malignant behaviors of tumor cells both in vivo and in vitro. Mechanically, the downregulation of RRAD promoted the internal flow of Ca2+ and elevated its concentration in the nucleus, which resulted in the activation of the CAMKIV-CREB1 axis to induce the transcription of the glucose transporter GLUT3. GLUT inhibitor-1, as an inhibitor of GLUT3, could suppress this vigorous energy metabolism and malignant behaviors caused by the downregulation of RRAD. Taken together, our study revealed that enhanced energy metabolism in the tumor margin mediated by RRAD promotes the progression of OSCC and proved that GLUT3 is a potential target for future treatment of OSCC.
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Affiliation(s)
- Aoming Cheng
- Department of Oral and Maxillofacial-Head and Neck Oncology, Beijing Stomatological Hospital, Capital Medical University, Beijing, China
| | - Qiaoshi Xu
- Department of Oral and Maxillofacial-Head and Neck Oncology, Beijing Stomatological Hospital, Capital Medical University, Beijing, China
| | - Bo Li
- Department of Oral and Maxillofacial-Head and Neck Oncology, Beijing Stomatological Hospital, Capital Medical University, Beijing, China
| | - Lirui Zhang
- Department of Oral and Maxillofacial-Head and Neck Oncology, Beijing Stomatological Hospital, Capital Medical University, Beijing, China
| | - Hao Wang
- Department of Oral and Maxillofacial-Head and Neck Oncology, Beijing Stomatological Hospital, Capital Medical University, Beijing, China
| | - Chang Liu
- Department of Oral and Maxillofacial-Head and Neck Oncology, Beijing Stomatological Hospital, Capital Medical University, Beijing, China
| | - Zhengxue Han
- Department of Oral and Maxillofacial-Head and Neck Oncology, Beijing Stomatological Hospital, Capital Medical University, Beijing, China.
| | - Zhien Feng
- Department of Oral and Maxillofacial-Head and Neck Oncology, Beijing Stomatological Hospital, Capital Medical University, Beijing, China.
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3
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Cao R, Tian H, Zhang Y, Liu G, Xu H, Rao G, Tian Y, Fu X. Signaling pathways and intervention for therapy of type 2 diabetes mellitus. MedComm (Beijing) 2023; 4:e283. [PMID: 37303813 PMCID: PMC10248034 DOI: 10.1002/mco2.283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 04/18/2023] [Accepted: 04/27/2023] [Indexed: 06/13/2023] Open
Abstract
Type 2 diabetes mellitus (T2DM) represents one of the fastest growing epidemic metabolic disorders worldwide and is a strong contributor for a broad range of comorbidities, including vascular, visual, neurological, kidney, and liver diseases. Moreover, recent data suggest a mutual interplay between T2DM and Corona Virus Disease 2019 (COVID-19). T2DM is characterized by insulin resistance (IR) and pancreatic β cell dysfunction. Pioneering discoveries throughout the past few decades have established notable links between signaling pathways and T2DM pathogenesis and therapy. Importantly, a number of signaling pathways substantially control the advancement of core pathological changes in T2DM, including IR and β cell dysfunction, as well as additional pathogenic disturbances. Accordingly, an improved understanding of these signaling pathways sheds light on tractable targets and strategies for developing and repurposing critical therapies to treat T2DM and its complications. In this review, we provide a brief overview of the history of T2DM and signaling pathways, and offer a systematic update on the role and mechanism of key signaling pathways underlying the onset, development, and progression of T2DM. In this content, we also summarize current therapeutic drugs/agents associated with signaling pathways for the treatment of T2DM and its complications, and discuss some implications and directions to the future of this field.
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Affiliation(s)
- Rong Cao
- Department of Endocrinology and MetabolismState Key Laboratory of Biotherapy and Cancer CenterWest China HospitalSichuan University and Collaborative Innovation Center of BiotherapyChengduSichuanChina
| | - Huimin Tian
- Department of Endocrinology and MetabolismState Key Laboratory of Biotherapy and Cancer CenterWest China Medical School, West China HospitalSichuan UniversityChengduSichuanChina
| | - Yu Zhang
- Department of Endocrinology and MetabolismState Key Laboratory of Biotherapy and Cancer CenterWest China Medical School, West China HospitalSichuan UniversityChengduSichuanChina
| | - Geng Liu
- Department of Endocrinology and MetabolismState Key Laboratory of Biotherapy and Cancer CenterWest China HospitalSichuan University and Collaborative Innovation Center of BiotherapyChengduSichuanChina
| | - Haixia Xu
- Department of Endocrinology and MetabolismState Key Laboratory of Biotherapy and Cancer CenterWest China HospitalSichuan University and Collaborative Innovation Center of BiotherapyChengduSichuanChina
| | - Guocheng Rao
- Department of Endocrinology and MetabolismState Key Laboratory of Biotherapy and Cancer CenterWest China Medical School, West China HospitalSichuan UniversityChengduSichuanChina
| | - Yan Tian
- Department of Endocrinology and MetabolismState Key Laboratory of Biotherapy and Cancer CenterWest China HospitalSichuan University and Collaborative Innovation Center of BiotherapyChengduSichuanChina
| | - Xianghui Fu
- Department of Endocrinology and MetabolismState Key Laboratory of Biotherapy and Cancer CenterWest China HospitalSichuan University and Collaborative Innovation Center of BiotherapyChengduSichuanChina
- Department of Endocrinology and MetabolismState Key Laboratory of Biotherapy and Cancer CenterWest China Medical School, West China HospitalSichuan UniversityChengduSichuanChina
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Shvadchenko AM, Volobueva MN, Ivanova VO, Beletskiy AP, Smirnova GR, Bal NV, Balaban PM. New Context Significantly Changes Expression of Irs2 Gene in Hippocampal Areas. BIOCHEMISTRY. BIOKHIMIIA 2022; 87:1243-1251. [PMID: 36509718 DOI: 10.1134/s0006297922110037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Memory formation is a complex process involving changes in the synaptic activity and gene expression encoding the insulin-like growth factors. We analyzed changes in the expression of genes encoding the insulin/insulin-like growth factors' proteins at the early period of learning in the CA1 region and dentate gyrus of the dorsal and ventral hippocampus in mice 1 hour after presentation of a new context (contextual fear conditioning) with and without negative reinforcement. It was found that in addition to changes in the expression of immediate early genes c-Fos (in all studied hippocampal fields) and Arc (in dorsal and ventral CA1, as well as in dorsal dentate gyrus), exposure to a new context significantly altered expression of the insulin receptor substrate 2 gene (Irs2) in dorsal CA1 and ventral dentate gyrus irrespectively of the negative reinforcement, which suggests participation of the insulin/IGF system in the early stages of neural activation during learning.
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Affiliation(s)
- Anastasia M Shvadchenko
- Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, 117485, Russia
| | - Maria N Volobueva
- Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, 117485, Russia
| | - Violetta O Ivanova
- Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, 117485, Russia
| | - Alexandr P Beletskiy
- Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, 117485, Russia
| | - Gulnur R Smirnova
- Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, 117485, Russia
| | - Natalia V Bal
- Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, 117485, Russia
| | - Pavel M Balaban
- Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, 117485, Russia.
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Liu B, Ruz‐Maldonado I, Toczyska K, Olaniru OE, Zariwala MG, Hopkins D, Zhao M, Persaud SJ. The selective serotonin reuptake inhibitor fluoxetine has direct effects on beta cells, promoting insulin secretion and increasing beta-cell mass. Diabetes Obes Metab 2022; 24:2038-2050. [PMID: 35676820 PMCID: PMC9545812 DOI: 10.1111/dom.14791] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 05/23/2022] [Accepted: 06/06/2022] [Indexed: 12/05/2022]
Abstract
AIM This study investigated whether therapeutically relevant concentrations of fluoxetine, which have been shown to reduce plasma glucose and glycated haemoglobin independent of changes in food intake and body weight, regulate beta-cell function and improve glucose homeostasis. METHODS Cell viability, insulin secretion, beta-cell proliferation and apoptosis were assessed after exposure of MIN6 beta cells or isolated mouse and human islets to 0.1, 1 or 10 μmol/L fluoxetine. The effect of fluoxetine (10 mg/kg body weight) administration on glucose homeostasis and islet function was also examined in ob/ob mice. RESULTS Exposure of MIN6 cells and mouse islets to 0.1 and 1 μmol/L fluoxetine for 72 hours did not compromise cell viability but 10 μmol/L fluoxetine significantly increased Trypan blue uptake. The dose of 1 μmol/L fluoxetine significantly increased beta-cell proliferation and protected islet cells from cytokine-induced apoptosis. In addition, 1 μmol/L fluoxetine induced rapid and reversible potentiation of glucose-stimulated insulin secretion from islets isolated from mice, and from lean and obese human donors. Finally, intraperitoneal administration of fluoxetine to ob/ob mice over 14 days improved glucose tolerance and resulted in significant increases in beta-cell proliferation and enhanced insulin secretory capacity. CONCLUSIONS These data are consistent with a role for fluoxetine in regulating glucose homeostasis through direct effects on beta cells. Fluoxetine thus demonstrates promise as a preferential antidepressant for patients with concomitant occurrence of depression and diabetes.
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Affiliation(s)
- Bo Liu
- Department of Diabetes, School of Cardiovascular and Metabolic Medicine and Sciences, Faculty of Life Sciences & MedicineKing's College LondonLondonUK
| | - Inmaculada Ruz‐Maldonado
- Department of Diabetes, School of Cardiovascular and Metabolic Medicine and Sciences, Faculty of Life Sciences & MedicineKing's College LondonLondonUK
- Comparative Medicine and Pathology, Vascular Biology and Therapeutics Program (VBT) Program in Integrative Cell Signaling and Neurobiology of Metabolism (ICSNM)Yale University School of MedicineNew HavenConnecticutUSA
| | - Klaudia Toczyska
- Department of Diabetes, School of Cardiovascular and Metabolic Medicine and Sciences, Faculty of Life Sciences & MedicineKing's College LondonLondonUK
| | - Oladapo E. Olaniru
- Department of Diabetes, School of Cardiovascular and Metabolic Medicine and Sciences, Faculty of Life Sciences & MedicineKing's College LondonLondonUK
| | | | - David Hopkins
- Department of Diabetes, School of Cardiovascular and Metabolic Medicine and Sciences, Faculty of Life Sciences & MedicineKing's College LondonLondonUK
| | - Min Zhao
- Department of Diabetes, School of Cardiovascular and Metabolic Medicine and Sciences, Faculty of Life Sciences & MedicineKing's College LondonLondonUK
| | - Shanta J. Persaud
- Department of Diabetes, School of Cardiovascular and Metabolic Medicine and Sciences, Faculty of Life Sciences & MedicineKing's College LondonLondonUK
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6
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Yoon JS, Sasaki S, Velghe J, Lee MYY, Winata H, Nian C, Lynn FC. Calcium-dependent transcriptional changes in human pancreatic islet cells reveal functional diversity in islet cell subtypes. Diabetologia 2022; 65:1519-1533. [PMID: 35616696 PMCID: PMC9345846 DOI: 10.1007/s00125-022-05718-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 02/11/2022] [Indexed: 11/25/2022]
Abstract
AIMS/HYPOTHESIS Pancreatic islets depend on cytosolic calcium (Ca2+) to trigger the secretion of glucoregulatory hormones and trigger transcriptional regulation of genes important for islet response to stimuli. To date, there has not been an attempt to profile Ca2+-regulated gene expression in all islet cell types. Our aim was to construct a large single-cell transcriptomic dataset from human islets exposed to conditions that would acutely induce or inhibit intracellular Ca2+ signalling, while preserving biological heterogeneity. METHODS We exposed intact human islets from three donors to the following conditions: (1) 2.8 mmol/l glucose; (2) 16 mmol/l glucose and 40 mmol/l KCl to maximally stimulate Ca2+ signalling; and (3) 16 mmol/l glucose, 40 mmol/l KCl and 5 mmol/l EGTA (Ca2+ chelator) to inhibit Ca2+ signalling, for 1 h. We sequenced 68,650 cells from all islet cell types, and further subsetted the cells to form an endocrine cell-specific dataset of 59,373 cells expressing INS, GCG, SST or PPY. We compared transcriptomes across conditions to determine the differentially expressed Ca2+-regulated genes in each endocrine cell type, and in each endocrine cell subcluster of alpha and beta cells. RESULTS Based on the number of Ca2+-regulated genes, we found that each alpha and beta cell cluster had a different magnitude of Ca2+ response. We also showed that polyhormonal clusters expressing both INS and GCG, or both INS and SST, are defined by Ca2+-regulated genes specific to each cluster. Finally, we identified the gene PCDH7 from the beta cell clusters that had the highest number of Ca2+-regulated genes, and showed that cells expressing cell surface PCDH7 protein have enhanced glucose-stimulated insulin secretory function. CONCLUSIONS/INTERPRETATION Here we use our large-scale, multi-condition, single-cell dataset to show that human islets have cell-type-specific Ca2+-regulated gene expression profiles, some of them specific to subpopulations. In our dataset, we identify PCDH7 as a novel marker of beta cells having an increased number of Ca2+-regulated genes and enhanced insulin secretory function. DATA AVAILABILITY A searchable and user-friendly format of the data in this study, specifically designed for rapid mining of single-cell RNA sequencing data, is available at https://lynnlab.shinyapps.io/Human_Islet_Atlas/ . The raw data files are available at NCBI Gene Expression Omnibus (GSE196715).
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Affiliation(s)
- Ji Soo Yoon
- Diabetes Research Group, BC Children's Hospital Research Institute, Vancouver, BC, Canada
- CELL Graduate Program, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Shugo Sasaki
- Diabetes Research Group, BC Children's Hospital Research Institute, Vancouver, BC, Canada
- Department of Surgery, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Jane Velghe
- Diabetes Research Group, BC Children's Hospital Research Institute, Vancouver, BC, Canada
- Department of Surgery, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Michelle Y Y Lee
- Diabetes Research Group, BC Children's Hospital Research Institute, Vancouver, BC, Canada
- Department of Surgery, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Helena Winata
- Diabetes Research Group, BC Children's Hospital Research Institute, Vancouver, BC, Canada
- Department of Surgery, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Cuilan Nian
- Diabetes Research Group, BC Children's Hospital Research Institute, Vancouver, BC, Canada
- Department of Surgery, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Francis C Lynn
- Diabetes Research Group, BC Children's Hospital Research Institute, Vancouver, BC, Canada.
- Department of Surgery, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada.
- School of Biomedical Engineering, University of British Columbia, Vancouver, BC, Canada.
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7
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Miranda JG, Schleicher WE, Wells KL, Ramirez DG, Landgrave SP, Benninger RKP. Dynamic changes in β-cell [Ca 2+] regulate NFAT activation, gene transcription, and islet gap junction communication. Mol Metab 2022; 57:101430. [PMID: 34979329 PMCID: PMC8804269 DOI: 10.1016/j.molmet.2021.101430] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 12/28/2021] [Accepted: 12/29/2021] [Indexed: 11/23/2022] Open
Abstract
OBJECTIVE Diabetes occurs because of insufficient insulin secretion due to β-cell dysfunction within the islet of Langerhans. Elevated glucose levels trigger β-cell membrane depolarization, action potential generation, and slow sustained free-Ca2+ ([Ca2+]) oscillations, which trigger insulin release. Nuclear factor of activated T-cell (NFAT) is a transcription factor, which is regulated by the increases in [Ca2+] and calceineurin (CaN) activation. NFAT regulation links cell activity with gene transcription in many systems and regulates proliferation and insulin granule biogenesis within the β-cell. However, the link between the regulation of β-cell electrical activity and oscillatory [Ca2+] dynamics with NFAT activation and downstream transcription is poorly understood. Here, we tested whether dynamic changes to β-cell electrical activity and [Ca2+] regulate NFAT activation and downstream transcription. METHODS In cell lines, mouse islets, and human islets, including those from donors with type 2 diabetes, we applied both agonists/antagonists of ion channels together with optogenetics to modulate β-cell electrical activity. We measured the dynamics of [Ca2+] and NFAT activation as well as performed whole transcriptome and functional analyses. RESULTS Both glucose-induced membrane depolarization and optogenetic stimulation triggered NFAT activation as well as increased the transcription of NFAT targets and intermediate early genes (IEGs). Importantly, slow, sustained [Ca2+] oscillation conditions led to NFAT activation and downstream transcription. In contrast, in human islets from donors with type2 diabetes, NFAT activation by glucose was diminished, but rescued upon pharmacological stimulation of electrical activity. NFAT activation regulated GJD2 expression and increased Cx36 gap junction permeability upon elevated oscillatory [Ca2+] dynamics. However, it is unclear if NFAT directly binds the GJD2 gene to regulate expression. CONCLUSIONS This study provides an insight into the specific patterns of electrical activity that regulate NFAT activation, gene transcription, and islet function. In addition, it provides information on how these factors are disrupted in diabetes.
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Affiliation(s)
- Jose G Miranda
- Department of Bioengineering, University of Colorado Anschutz Medical Campus, Aurora CO, 80045, USA
| | - Wolfgang E Schleicher
- Department of Bioengineering, University of Colorado Anschutz Medical Campus, Aurora CO, 80045, USA
| | - Kristen L Wells
- Barbara Davis Center for Childhood Diabetes, University of Colorado Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - David G Ramirez
- Department of Bioengineering, University of Colorado Anschutz Medical Campus, Aurora CO, 80045, USA
| | - Samantha P Landgrave
- Program in Cell Biology, Stem Cell and Development, University of Colorado Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - Richard K P Benninger
- Department of Bioengineering, University of Colorado Anschutz Medical Campus, Aurora CO, 80045, USA; Program in Cell Biology, Stem Cell and Development, University of Colorado Anschutz Medical Campus, Aurora, CO, 80045, USA; Barbara Davis Center for Childhood Diabetes, University of Colorado Anschutz Medical Campus, Aurora, CO, 80045, USA.
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8
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Kaimala S, Kumar CA, Allouh MZ, Ansari SA, Emerald BS. Epigenetic modifications in pancreas development, diabetes, and therapeutics. Med Res Rev 2022; 42:1343-1371. [PMID: 34984701 PMCID: PMC9306699 DOI: 10.1002/med.21878] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 11/24/2021] [Accepted: 12/18/2021] [Indexed: 12/26/2022]
Abstract
A recent International Diabetes Federation report suggests that more than 463 million people between 20 and 79 years have diabetes. Of the 20 million women affected by hyperglycemia during pregnancy, 84% have gestational diabetes. In addition, more than 1.1 million children or adolescents are affected by type 1 diabetes. Factors contributing to the increase in diabetes prevalence are complex and include contributions from genetic, environmental, and epigenetic factors. However, molecular regulatory mechanisms influencing the progression of an individual towards increased susceptibility to metabolic diseases such as diabetes are not fully understood. Recent studies suggest that the pathogenesis of diabetes involves epigenetic changes, resulting in a persistently dysregulated metabolic phenotype. This review summarizes the role of epigenetic mechanisms, mainly DNA methylation and histone modifications, in the development of the pancreas, their contribution to the development of diabetes, and the potential employment of epigenetic modulators in diabetes treatment.
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Affiliation(s)
- Suneesh Kaimala
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, Abu Dhabi, UAE
| | - Challagandla Anil Kumar
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, Abu Dhabi, UAE
| | - Mohammed Z Allouh
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, Abu Dhabi, UAE
| | - Suraiya Anjum Ansari
- Department of Biochemistry, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, Abu Dhabi, UAE.,Zayed Center for Health Sciences, United Arab Emirates University, Al Ain, Abu Dhabi, UAE
| | - Bright Starling Emerald
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, Abu Dhabi, UAE.,Zayed Center for Health Sciences, United Arab Emirates University, Al Ain, Abu Dhabi, UAE
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Liu J, Li Y, Gao N, Ji J, He Q. Calcium/calmodulin-dependent protein kinase IV regulates vascular autophagy and insulin signaling through Akt/mTOR/CREB pathway in ob/ob mice. J Physiol Biochem 2021; 78:199-211. [PMID: 34741274 DOI: 10.1007/s13105-021-00853-6] [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: 04/03/2020] [Accepted: 10/20/2021] [Indexed: 10/19/2022]
Abstract
Calcium/calmodulin-dependent protein kinase IV (CaMKIV) has recently emerged as an important regulator of glucose metabolism and vascular function, but the underlying mechanism is not fully understood. Recently, we revealed that CaMKIV limits metabolic disorder and liver insulin resistance and regulates autophagy in high-fat diet-induced obese mice. In the present study, we demonstrated that CaMKIV was not only associated with improvement of glucose tolerance and insulin sensitivity in ob/ob mice but also involved in the regulation of vascular autophagy and mitochondrial biogenesis. Our in vitro data indicated that CaMKIV reversed autophagic imbalance and restored insulin sensitivity in palmitate-induced A7r5 cells with insulin resistance. However, the protective effects of CaMKIV were nullified by suppression of Akt, mTOR, or CREB, suggesting that CaMKIV inhibits autophagy and improves insulin signaling in insulin resistance cell models in an Akt/mTOR/CREB-dependent manner. CaMKIV reversed autophagic imbalance and insulin sensitivity in vascular tissues and vascular cells through Akt/mTOR/CREB signaling, which could be regarded as a novel opportunity for the treatment of insulin resistance.
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Affiliation(s)
- Jiali Liu
- Department of Clinical Laboratory, Xi'an Jiaotong University Second Affiliated Hospital, 157 West 5 Road, Xi'an, 710004, Shaanxi, China
| | - Yue Li
- Department of Clinical Laboratory, Xi'an Jiaotong University Second Affiliated Hospital, 157 West 5 Road, Xi'an, 710004, Shaanxi, China
| | - Ning Gao
- Department of Clinical Laboratory, Xi'an Jiaotong University Second Affiliated Hospital, 157 West 5 Road, Xi'an, 710004, Shaanxi, China
| | - Jing Ji
- Department of Clinical Laboratory, Xi'an Jiaotong University Second Affiliated Hospital, 157 West 5 Road, Xi'an, 710004, Shaanxi, China
| | - Qian He
- Department of Clinical Laboratory, Xi'an Jiaotong University Second Affiliated Hospital, 157 West 5 Road, Xi'an, 710004, Shaanxi, China.
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10
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Becker A, Wardas B, Salah H, Amini M, Fecher-Trost C, Sen Q, Martus D, Beck A, Philipp SE, Flockerzi V, Belkacemi A. Cavβ3 Regulates Ca 2+ Signaling and Insulin Expression in Pancreatic β-Cells in a Cell-Autonomous Manner. Diabetes 2021; 70:2532-2544. [PMID: 34426509 PMCID: PMC8564405 DOI: 10.2337/db21-0078] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 08/12/2021] [Indexed: 11/13/2022]
Abstract
Voltage-gated Ca2+ (Cav) channels consist of a pore-forming Cavα1 subunit and auxiliary Cavα2-δ and Cavβ subunits. In fibroblasts, Cavβ3, independent of its role as a Cav subunit, reduces the sensitivity to low concentrations of inositol-1,4,5-trisphosphate (IP3). Similarly, Cavβ3 could affect cytosolic calcium concentration ([Ca2 +]) in pancreatic β-cells. In this study, we deleted the Cavβ3-encoding gene Cacnb3 in insulin-secreting rat β-(Ins-1) cells using CRISPR/Cas9. These cells were used as controls to investigate the role of Cavβ3 on Ca2+ signaling, glucose-induced insulin secretion (GIIS), Cav channel activity, and gene expression in wild-type cells in which Cavβ3 and the IP3 receptor were coimmunoprecipitated. Transcript and protein profiling revealed significantly increased levels of insulin transcription factor Mafa, CaMKIV, proprotein convertase subtilisin/kexin type-1, and nitric oxide synthase-1 in Cavβ3-knockout cells. In the absence of Cavβ3, Cav currents were not altered. In contrast, CREB activity, the amount of MAFA protein and GIIS, the extent of IP3-dependent Ca2+ release and the frequency of Ca2+ oscillations were increased. These processes were decreased by the Cavβ3 protein in a concentration-dependent manner. Our study shows that Cavβ3 interacts with the IP3 receptor in isolated β-cells, controls IP3-dependent Ca2+-signaling independently of Cav channel functions, and thereby regulates insulin expression and its glucose-dependent release in a cell-autonomous manner.
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Affiliation(s)
- Alexander Becker
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Präklinisches Zentrum für Molekulare Signalverarbeitung der Universität des Saarlandes, Homburg, Germany
| | - Barbara Wardas
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Präklinisches Zentrum für Molekulare Signalverarbeitung der Universität des Saarlandes, Homburg, Germany
| | - Houssein Salah
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Präklinisches Zentrum für Molekulare Signalverarbeitung der Universität des Saarlandes, Homburg, Germany
| | - Maryam Amini
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Präklinisches Zentrum für Molekulare Signalverarbeitung der Universität des Saarlandes, Homburg, Germany
| | - Claudia Fecher-Trost
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Präklinisches Zentrum für Molekulare Signalverarbeitung der Universität des Saarlandes, Homburg, Germany
| | - Qiao Sen
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Präklinisches Zentrum für Molekulare Signalverarbeitung der Universität des Saarlandes, Homburg, Germany
| | - Damian Martus
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Präklinisches Zentrum für Molekulare Signalverarbeitung der Universität des Saarlandes, Homburg, Germany
| | - Andreas Beck
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Präklinisches Zentrum für Molekulare Signalverarbeitung der Universität des Saarlandes, Homburg, Germany
| | - Stephan E Philipp
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Präklinisches Zentrum für Molekulare Signalverarbeitung der Universität des Saarlandes, Homburg, Germany
| | - Veit Flockerzi
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Präklinisches Zentrum für Molekulare Signalverarbeitung der Universität des Saarlandes, Homburg, Germany
| | - Anouar Belkacemi
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Präklinisches Zentrum für Molekulare Signalverarbeitung der Universität des Saarlandes, Homburg, Germany
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11
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Spears E, Serafimidis I, Powers AC, Gavalas A. Debates in Pancreatic Beta Cell Biology: Proliferation Versus Progenitor Differentiation and Transdifferentiation in Restoring β Cell Mass. Front Endocrinol (Lausanne) 2021; 12:722250. [PMID: 34421829 PMCID: PMC8378310 DOI: 10.3389/fendo.2021.722250] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 07/14/2021] [Indexed: 12/12/2022] Open
Abstract
In all forms of diabetes, β cell mass or function is reduced and therefore the capacity of the pancreatic cells for regeneration or replenishment is a critical need. Diverse lines of research have shown the capacity of endocrine as well as acinar, ductal and centroacinar cells to generate new β cells. Several experimental approaches using injury models, pharmacological or genetic interventions, isolation and in vitro expansion of putative progenitors followed by transplantations or a combination thereof have suggested several pathways for β cell neogenesis or regeneration. The experimental results have also generated controversy related to the limitations and interpretation of the experimental approaches and ultimately their physiological relevance, particularly when considering differences between mouse, the primary animal model, and human. As a result, consensus is lacking regarding the relative importance of islet cell proliferation or progenitor differentiation and transdifferentiation of other pancreatic cell types in generating new β cells. In this review we summarize and evaluate recent experimental approaches and findings related to islet regeneration and address their relevance and potential clinical application in the fight against diabetes.
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Affiliation(s)
- Erick Spears
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Ioannis Serafimidis
- Center of Basic Research, Biomedical Research Foundation of the Academy of Athens, Athens, Greece
| | - Alvin C. Powers
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, United States
- VA Tennessee Valley Healthcare System, Nashville, TN, United States
- *Correspondence: Anthony Gavalas, ; Alvin C. Powers,
| | - Anthony Gavalas
- Paul Langerhans Institute Dresden (PLID) of Helmholtz Center Munich at the University Clinic Carl Gustav Carus of TU Dresden, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
- German Centre for Diabetes Research (DZD), Neuherberg, Germany
- *Correspondence: Anthony Gavalas, ; Alvin C. Powers,
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12
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Kuang MT, Li JY, Yang XB, Yang L, Xu JY, Yan S, Lv YF, Ren FC, Hu JM, Zhou J. Structural characterization and hypoglycemic effect via stimulating glucagon-like peptide-1 secretion of two polysaccharides from Dendrobium officinale. Carbohydr Polym 2020; 241:116326. [DOI: 10.1016/j.carbpol.2020.116326] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 04/15/2020] [Accepted: 04/15/2020] [Indexed: 12/12/2022]
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Sabatini PV, Speckmann T, Lynn FC. Friend and foe: β-cell Ca 2+ signaling and the development of diabetes. Mol Metab 2018; 21:1-12. [PMID: 30630689 PMCID: PMC6407368 DOI: 10.1016/j.molmet.2018.12.007] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 12/03/2018] [Accepted: 12/19/2018] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND The divalent cation Calcium (Ca2+) regulates a wide range of processes in disparate cell types. Within insulin-producing β-cells, increases in cytosolic Ca2+ directly stimulate insulin vesicle exocytosis, but also initiate multiple signaling pathways. Mediated through activation of downstream kinases and transcription factors, Ca2+-regulated signaling pathways leverage substantial influence on a number of critical cellular processes within the β-cell. Additionally, there is evidence that prolonged activation of these same pathways is detrimental to β-cell health and may contribute to Type 2 Diabetes pathogenesis. SCOPE OF REVIEW This review aims to briefly highlight canonical Ca2+ signaling pathways in β-cells and how β-cells regulate the movement of Ca2+ across numerous organelles and microdomains. As a main focus, this review synthesizes experimental data from in vitro and in vivo models on both the beneficial and detrimental effects of Ca2+ signaling pathways for β-cell function and health. MAJOR CONCLUSIONS Acute increases in intracellular Ca2+ stimulate a number of signaling cascades, resulting in (de-)phosphorylation events and activation of downstream transcription factors. The short-term stimulation of these Ca2+ signaling pathways promotes numerous cellular processes critical to β-cell function, including increased viability, replication, and insulin production and secretion. Conversely, chronic stimulation of Ca2+ signaling pathways increases β-cell ER stress and results in the loss of β-cell differentiation status. Together, decades of study demonstrate that Ca2+ movement is tightly regulated within the β-cell, which is at least partially due to its dual roles as a potent signaling molecule.
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Affiliation(s)
- Paul V Sabatini
- Diabetes Research Group, BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada; Department of Surgery, University of British Columbia, Vancouver, British Columbia, Canada; Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada; Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Thilo Speckmann
- Diabetes Research Group, BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada; Department of Surgery, University of British Columbia, Vancouver, British Columbia, Canada; Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Francis C Lynn
- Diabetes Research Group, BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada; Department of Surgery, University of British Columbia, Vancouver, British Columbia, Canada; Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada.
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14
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Hollenbach M, Klöting N, Sommerer I, Lorenz J, Heindl M, Kern M, Mössner J, Blüher M, Hoffmeister A. p8 deficiency leads to elevated pancreatic beta cell mass but does not contribute to insulin resistance in mice fed with high-fat diet. PLoS One 2018; 13:e0201159. [PMID: 30040846 PMCID: PMC6057664 DOI: 10.1371/journal.pone.0201159] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 07/10/2018] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND p8 was initially described as being overexpressed in acute pancreatitis and encoding a ubiquitous stress protein. Analysis of insulin sensitivity and glucose tolerance in p8-knockout and haplodeficient mice revealed counterintuitive results. Thus, we determined glycemic control of p8 in mice fed with standard (SD) and high-fat diet (HFD). METHODS p8-/- and wild type (p8+/+) mice were used for analysis of glucagon (immunohistochemistry), insulin levels (ELISA) and beta cell mass. Hyperinsulinemic- euglycemic glucose clamp technique, i.p. glucose tolerance test (ipGTT), i.p. insulin tolerance test (ipITT) and metabolic chamber analysis were performed in SD (4% fat) and HFD (55% fat) groups. RESULTS p8-/- mice showed no differences in glucagon or insulin content but higher insulin secretion from pancreatic islets upon glucose stimulation. p8 deficiency resulted in elevated beta cell mass but was not associated with increased insulin resistance in ipGTT or ipITT. Glucose clamp tests also revealed no evidence of association of p8 deficiency with insulin resistance. Metabolic chamber analysis showed equal energy expenditure in p8-/- mice and wild type animals. CONCLUSION p8 depletion may contribute to glucose metabolism via stress-induced insulin production and elevated beta cell mass. Nevertheless, p8 knockout showed no impact on insulin resistance in SD and HFD-fed mice.
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Affiliation(s)
- Marcus Hollenbach
- Department of Medicine, Neurology and Dermatology, Division of Gastroenterology and Rheumatology, University of Leipzig, Leipzig, Germany
- * E-mail:
| | - Nora Klöting
- IFB Adiposity Disease, University of Leipzig, Leipzig, Germany
| | - Ines Sommerer
- Department of Medicine, Neurology and Dermatology, Division of Gastroenterology and Rheumatology, University of Leipzig, Leipzig, Germany
| | - Jana Lorenz
- Department of Medicine, Neurology and Dermatology, Division of Gastroenterology and Rheumatology, University of Leipzig, Leipzig, Germany
| | - Mario Heindl
- Department of Medicine, Neurology and Dermatology, Division of Gastroenterology and Rheumatology, University of Leipzig, Leipzig, Germany
| | - Matthias Kern
- German Diabetes Center Leipzig, University of Leipzig, Leipzig, Germany
| | - Joachim Mössner
- Department of Medicine, Neurology and Dermatology, Division of Gastroenterology and Rheumatology, University of Leipzig, Leipzig, Germany
| | - Matthias Blüher
- Department of Medicine, Neurology and Dermatology, Division of Endocrinology and Nephrology, University of Leipzig, Leipzig, Germany
| | - Albrecht Hoffmeister
- Department of Medicine, Neurology and Dermatology, Division of Gastroenterology and Rheumatology, University of Leipzig, Leipzig, Germany
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15
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Epicatechin potentiation of glucose-stimulated insulin secretion in INS-1 cells is not dependent on its antioxidant activity. Acta Pharmacol Sin 2018; 39:893-902. [PMID: 29417944 DOI: 10.1038/aps.2017.174] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Accepted: 11/26/2017] [Indexed: 12/13/2022] Open
Abstract
Epicatechin (EC) is a monomeric flavan-3-ol. We have previously demonstrated that glucose-intolerant rats fed flavan-3-ols exhibit improved pancreatic islet function corresponding with an increase in circulating EC-derived metabolites. Thus, we speculate that EC may act as a cellular signaling molecule in vivo to modulate insulin secretion. In this study we further examined the effects of different concentrations of EC on H2O2 or hyperglycemia-induced ROS production, as well as on saturated fatty acid (SFA)-impaired glucose-stimulated insulin secretion (GSIS) in INS-1 cell line in vitro. We showed that EC at a high concentration (30 μmol/L), but not a low concentration (0.3 μmol/L), significantly decreased H2O2 or hyperglycemia-induced ROS production in INS-1 cells. However, EC (0.3 μmol/L) significantly enhanced SFA-impaired GSIS in INS-1 cells. Addition of KN-93, a CaMKII inhibitor, blocked the effect of EC on insulin secretion and decreased CaMKII phosphorylation. Addition of GW1100, a GPR40 antagonist, significantly attenuated EC-enhanced GSIS, but only marginally affected CaMKII phosphorylation. These results demonstrate that EC at a physiological concentration promotes GSIS in SFA-impaired β-cells via activation of the CaMKII pathway and is consistent with its function as a GPR40 ligand. The findings support a role for EC as a cellular signaling molecule in vivo and further delineate the signaling pathways of EC in β-cells.
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Tsuboi K, Mizukami H, Inaba W, Baba M, Yagihashi S. The dipeptidyl peptidase IV inhibitor vildagliptin suppresses development of neuropathy in diabetic rodents: effects on peripheral sensory nerve function, structure and molecular changes. J Neurochem 2016; 136:859-870. [PMID: 26603140 DOI: 10.1111/jnc.13439] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 11/03/2015] [Accepted: 11/04/2015] [Indexed: 01/01/2023]
Abstract
Incretin-related therapy was found to be beneficial for experimental diabetic neuropathy, but its mechanism is obscure. The purpose of this study is to explore the mechanism through which dipeptidyl peptidase IV inhibitor, vildagliptin (VG), influences neuropathy in diabetic rodents. To this end, non-obese type 2 diabetic Goto-Kakizaki rats (GK) and streptozotocin (STZ)-induced diabetic mice were treated with VG orally. Neuropathy was evaluated by nerve conduction velocity (NCV) in both GK and STZ-diabetic mice, whereas calcitonin-gene-related peptide expressions, neuronal cell size of dorsal root ganglion (DRG) and intraepidermal nerve fiber density were examined in GK. DRG from GK and STZ-diabetic mice served for the analyses of GLP-1 and insulin signaling. As results, VG treatment improved glucose intolerance and increased serum insulin and GLP-1 in GK accompanied by the amelioration of delayed NCV and neuronal atrophy, reduced calcitonin-gene-related peptide expressions and intraepidermal nerve fiber density. Diet restriction alone did not significantly influence these measures. Impaired GLP-1 signals such as cAMP response element binding protein, protein kinase B/Akt (PKB/Akt) and S6RP in DRG of GK were restored in VG-treated group, but the effect was equivocal in diet-treated GK. Concurrently, decreased phosphorylation of insulin receptor substrate 2 in GK was corrected by VG treatment. Consistent with the effect on GK, VG treatment improved NCV in diabetic mice without influence on hyperglycemia. DRG of VG-treated diabetic mice were characterized by correction of GLP-1 signals and insulin receptor substrate 2 phosphorylation without effects on insulin receptor β expression. The results suggest close association of neuropathy development with impaired signaling of insulin and GLP-1 in diabetic rodents. Diabetic neurons are resistant to insulin and such insulin resistance may contribute to development of neuropathy. DPP-IV inhibitor, vildagliptin, corrected insulin resistance and improved neuropathy irrespective of blood glucose via augmented action of GLP-1.
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Affiliation(s)
- Kentaro Tsuboi
- Department of Pathology and Molecular Medicine, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Hiroki Mizukami
- Department of Pathology and Molecular Medicine, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Wataru Inaba
- Department of Pathology and Molecular Medicine, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Masayuki Baba
- Department of Neurology, Aomori Prefectural Hospital, Aomori, Japan
| | - Soroku Yagihashi
- Department of Pathology and Molecular Medicine, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
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Naz H, Jameel E, Hoda N, Shandilya A, Khan P, Islam A, Ahmad F, Jayaram B, Hassan MI. Structure guided design of potential inhibitors of human calcium-calmodulin dependent protein kinase IV containing pyrimidine scaffold. Bioorg Med Chem Lett 2015; 26:782-788. [PMID: 26783179 DOI: 10.1016/j.bmcl.2015.12.098] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Revised: 12/01/2015] [Accepted: 12/29/2015] [Indexed: 12/26/2022]
Abstract
Calmodulin dependent protein kinase IV (CAMKIV) belongs to the serine/threonine protein kinase family and considered as an encouraging target for the development of novel anticancer agents. The interaction and binding behavior of three designed inhibitors of human CAMKIV, containing pyrimidine scaffold, was monitored by in vitro fluorescence titration and molecular docking calculations under physiological condition. In silico docking studies were performed to screen several compounds containing pyrimidine scaffold against CAMKIV. Molecular docking calculation predicted the binding of these ligands in active-site cavity of the CAMKIV structure correlating such interactions with a probable inhibition mechanism. Finally, three active pyrimidine substituted compounds (molecules 1-3) have been successfully synthesized and characterized by (1)H and (13)C NMR. Molecule 3 is showing very high binding-affinity for the CAMKIV, with a binding constant of 2.2×10(8), M(-1) (±0.20). All three compounds are nontoxic to HEK293 cells up to 50 μM. The cell proliferation inhibition study showed that the molecule 3 has lowest IC50 value (46±1.08 μM). The theoretical and experimental observations are significantly correlated. This study reveals some important observations to generate an improved pyrimidine based compound that holds promise as a therapeutic agent for the treatment of cancer and neurodegenerative diseases.
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Affiliation(s)
- Huma Naz
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India
| | - Ehtesham Jameel
- Department of Chemistry, B.R. Ambedkar Bihar University, Muzaffarpur 842001, Bihar, India
| | - Nasimul Hoda
- Department of Chemistry, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India.
| | - Ashutosh Shandilya
- Supercomputing Facility for Bioinformatics & Computational Biology, Indian Institute of Technology, Hauz Khas, New Delhi 110016, India; Department of Chemistry, Indian Institute of Technology, Hauz Khas, New Delhi 110016, India
| | - Parvez Khan
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India
| | - Asimul Islam
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India
| | - Faizan Ahmad
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India
| | - B Jayaram
- Supercomputing Facility for Bioinformatics & Computational Biology, Indian Institute of Technology, Hauz Khas, New Delhi 110016, India; Department of Chemistry, Indian Institute of Technology, Hauz Khas, New Delhi 110016, India
| | - Md Imtaiyaz Hassan
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India.
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Janssen LJ, Mukherjee S, Ask K. Calcium Homeostasis and Ionic Mechanisms in Pulmonary Fibroblasts. Am J Respir Cell Mol Biol 2015; 53:135-48. [PMID: 25785898 DOI: 10.1165/rcmb.2014-0269tr] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Fibroblasts are key cellular mediators of many chronic interstitial lung diseases, including idiopathic pulmonary fibrosis, scleroderma, sarcoidosis, drug-induced interstitial lung disease, and interstitial lung disease in connective tissue disease. A great deal of effort has been expended to understand the signaling mechanisms underlying the various cellular functions of fibroblasts. Recently, it has been shown that Ca(2+) oscillations play a central role in the regulation of gene expression in human pulmonary fibroblasts. However, the mechanisms whereby cytosolic [Ca(2+)] are regulated and [Ca(2+)] oscillations transduced are both poorly understood. In this review, we present the general concepts of [Ca(2+)] homeostasis, of ionic mechanisms responsible for various Ca(2+) fluxes, and of regulation of gene expression by [Ca(2+)]. In each case, we then also summarize the original findings that pertain specifically to pulmonary fibroblasts. From these data, we propose an overall signaling cascade by which excitation of the fibroblasts triggers pulsatile release of internally sequestered Ca(2+), which, in turn, activates membrane conductances, including voltage-dependent Ca(2+) influx pathways. Collectively, these events produce recurring Ca(2+) oscillations, the frequency of which is transduced by Ca(2+)-dependent transcription factors, which, in turn, orchestrate a variety of cellular events, including proliferation, synthesis/secretion of extracellular matrix proteins, autoactivation (production of transforming growth factor-β), and transformation into myofibroblasts. That unifying hypothesis, in turn, allows us to highlight several specific cellular targets and therapeutic intervention strategies aimed at controlling unwanted pulmonary fibrosis. The relationships between Ca(2+) signaling events and the unfolded protein response and apoptosis are also explored.
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Affiliation(s)
- Luke J Janssen
- Firestone Institute for Respiratory Health, St. Joseph's Hospital, and Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Subhendu Mukherjee
- Firestone Institute for Respiratory Health, St. Joseph's Hospital, and Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Kjetil Ask
- Firestone Institute for Respiratory Health, St. Joseph's Hospital, and Department of Medicine, McMaster University, Hamilton, Ontario, Canada
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19
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Wang G, Zhang H, Wang L, Wang Y, Huang H, Sun F. Ca(2+)/Calmodulin-Dependent Protein Kinase IV Promotes Interplay of Proteins in Chromatoid Body of Male Germ Cells. Sci Rep 2015; 5:12126. [PMID: 26179157 PMCID: PMC4503993 DOI: 10.1038/srep12126] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2014] [Accepted: 06/17/2015] [Indexed: 11/10/2022] Open
Abstract
The chromatoid body is a granule-like structure of male germ cells, containing many proteins and RNAs, and is important for spermatogenesis. However, the molecular mechanisms for the formation and function of the chromatoid body are still elusive. Here, we report that Ca(2+)/calmodulin-dependent protein kinase IV (CaMKIV) accumulates in the chromatoid body by immunofluorescence staining, indicating that CaMKIV is a new component of the chromatoid body. Furthermore, we find that CaMKIV can interplay with the other components of the chromatoid body by immunoprecipitation: mouse VASA homologue (MVH), mouse homologue of PIWI, PIWIL1 (MIWI), and kinesin KIF17b. Importantly, interplay between KIF17b and MVH or MIWI can be potentially regulated by CaMKIV. These results imply that CaMKIV plays a role in maintenance the structure of chromatoid body by regulating the associations of proteins in it.
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Affiliation(s)
- Guishuan Wang
- International Peace Maternity &Child Health Hospital, Institute of Embryo-Fetal Original Adult Disease Shanghai Key laboratory for Reproductive Medicine, School of Medicine, Shanghai Jiaotong University, Shanghai 200030, China
| | - Huijuan Zhang
- International Peace Maternity &Child Health Hospital, Institute of Embryo-Fetal Original Adult Disease Shanghai Key laboratory for Reproductive Medicine, School of Medicine, Shanghai Jiaotong University, Shanghai 200030, China
| | - Lu Wang
- International Peace Maternity &Child Health Hospital, Institute of Embryo-Fetal Original Adult Disease Shanghai Key laboratory for Reproductive Medicine, School of Medicine, Shanghai Jiaotong University, Shanghai 200030, China
| | - Yuan Wang
- International Peace Maternity &Child Health Hospital, Institute of Embryo-Fetal Original Adult Disease Shanghai Key laboratory for Reproductive Medicine, School of Medicine, Shanghai Jiaotong University, Shanghai 200030, China
| | - Hefeng Huang
- International Peace Maternity &Child Health Hospital, Institute of Embryo-Fetal Original Adult Disease Shanghai Key laboratory for Reproductive Medicine, School of Medicine, Shanghai Jiaotong University, Shanghai 200030, China
| | - Fei Sun
- International Peace Maternity &Child Health Hospital, Institute of Embryo-Fetal Original Adult Disease Shanghai Key laboratory for Reproductive Medicine, School of Medicine, Shanghai Jiaotong University, Shanghai 200030, China
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20
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da Silva Lippo BR, Batista TM, de Rezende LF, Cappelli AP, Camargo RL, Branco RCS, Barbosa Sampaio HC, Protzek AOP, Wanderley MI, Arantes VC, Corat MAF, Carneiro EM, Udrisar DP, Wanderley AG, Ferreira F. Low-protein diet disrupts the crosstalk between the PKA and PKC signaling pathways in isolated pancreatic islets. J Nutr Biochem 2015; 26:556-62. [DOI: 10.1016/j.jnutbio.2014.12.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Revised: 11/26/2014] [Accepted: 12/10/2014] [Indexed: 10/24/2022]
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21
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Barbosa-Sampaio HC, Drynda R, Liu B, Rodriguez De Ledesma AM, Malicet C, Iovanna JL, Jones PM, Muller DS, Persaud SJ. Reduced nuclear protein 1 expression improves insulin sensitivity and protects against diet-induced glucose intolerance through up-regulation of heat shock protein 70. Biochim Biophys Acta Mol Basis Dis 2015; 1852:962-9. [PMID: 25638293 DOI: 10.1016/j.bbadis.2015.01.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Revised: 01/14/2015] [Accepted: 01/21/2015] [Indexed: 01/08/2023]
Abstract
We recently reported that deletion of the stress-regulated nuclear protein 1 (Nupr1) protected against obesity-associated metabolic alterations due to increased beta cell mass, but complete Nupr1 ablation was not advantageous since it led to insulin resistance on a normal diet. The current study used Nupr1 haplodeficient mice to investigate whether a partial reduction in Nupr1 expression conferred beneficial effects on glucose homeostasis. Islet number, morphology and area, assessed by immunofluorescence and morphometric analyses, were not altered in Nupr1 haplodeficient mice under normal diet conditions and nor was beta cell BrdU incorporation. Glucose and insulin tolerance tests indicated that there were no significant changes in in vivo insulin secretion and glucose clearance in Nupr1 haplodeficient mice, and beta cell function in vitro was normal. However, reduced Nupr1 expression decreased visceral fat deposition and significantly increased insulin sensitivity in vivo. In contrast to wild type animals, high fat diet-fed Nupr1 haplodeficient mice were not hyperinsulinaemic or glucose intolerant, and their sustained insulin sensitivity was demonstrated by appropriate insulin-induced Akt phosphorylation, as determined by Western blotting. At the molecular level, measurements of gene expression levels and promoter activities identified Nupr1-dependent inhibition of heat shock factor-1-induced heat shock protein 70 (Hsp70) expression as a mechanism through which Nupr1 regulates insulin sensitivity. We have shown for the first time that Nupr1 plays a central role in inhibiting Hsp70 expression in tissues regulating glucose homeostasis, and reductions in Nupr1 expression could be used to protect against the metabolic defects associated with obesity-induced insulin resistance.
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Affiliation(s)
- H C Barbosa-Sampaio
- Diabetes Research Group, Division of Diabetes and Nutritional Sciences, Faculty of Life Sciences and Medicine, King's College London, London SE1 1UL, United Kingdom
| | - R Drynda
- Diabetes Research Group, Division of Diabetes and Nutritional Sciences, Faculty of Life Sciences and Medicine, King's College London, London SE1 1UL, United Kingdom
| | - B Liu
- Diabetes Research Group, Division of Diabetes and Nutritional Sciences, Faculty of Life Sciences and Medicine, King's College London, London SE1 1UL, United Kingdom
| | - A M Rodriguez De Ledesma
- Diabetes Research Group, Division of Diabetes and Nutritional Sciences, Faculty of Life Sciences and Medicine, King's College London, London SE1 1UL, United Kingdom
| | - C Malicet
- INSERM U1068, Centre de Recherche en Cancérologie de Marseille, Parc Scientifique de Luminy, Case 915, 13288 Marseille Cedex 9, France
| | - J L Iovanna
- INSERM U1068, Centre de Recherche en Cancérologie de Marseille, Parc Scientifique de Luminy, Case 915, 13288 Marseille Cedex 9, France
| | - P M Jones
- Diabetes Research Group, Division of Diabetes and Nutritional Sciences, Faculty of Life Sciences and Medicine, King's College London, London SE1 1UL, United Kingdom
| | - D S Muller
- Diabetes Research Group, Division of Diabetes and Nutritional Sciences, Faculty of Life Sciences and Medicine, King's College London, London SE1 1UL, United Kingdom
| | - S J Persaud
- Diabetes Research Group, Division of Diabetes and Nutritional Sciences, Faculty of Life Sciences and Medicine, King's College London, London SE1 1UL, United Kingdom.
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Abstract
Because obesity rates have increased dramatically over the past 3 decades, type 2 diabetes has become increasingly prevalent as well. Type 2 diabetes is associated with decreased pancreatic β-cell mass and function, resulting in inadequate insulin production. Conversely, in nondiabetic obesity, an expansion in β-cell mass occurs to provide sufficient insulin and to prevent hyperglycemia. This expansion is at least in part due to β-cell proliferation. This review focuses on the mechanisms regulating obesity-induced β-cell proliferation in humans and mice. Many factors have potential roles in the regulation of obesity-driven β-cell proliferation, including nutrients, insulin, incretins, hepatocyte growth factor, and recently identified liver-derived secreted factors. Much is still unknown about the regulation of β-cell replication, especially in humans. The extracellular signals that activate proliferative pathways in obesity, the relative importance of each of these pathways, and the extent of cross-talk between these pathways are important areas of future study.
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Affiliation(s)
| | - Mieke Baan
- Division of Endocrinology, Department of Medicine, and,School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI; and
| | - Dawn Belt Davis
- Division of Endocrinology, Department of Medicine, and William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin
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23
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Bazwinsky-Wutschke I, Mühlbauer E, Albrecht E, Peschke E. Calcium-signaling components in rat insulinoma β-cells (INS-1) and pancreatic islets are differentially influenced by melatonin. J Pineal Res 2014; 56:439-49. [PMID: 24650091 DOI: 10.1111/jpi.12135] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Accepted: 03/14/2014] [Indexed: 11/28/2022]
Abstract
The pineal secretory product melatonin exerts its influence on the insulin secretion of pancreatic islets by different signaling pathways. The purpose of this study was to analyze the impact of melatonin on calcium-signaling components under different conditions. In a transfected INS-1 cell line overexpressing the human MT2 receptor (hMT2-INS-1), melatonin treatment induced even stronger depressive effects on calcium/calmodulin-dependent kinase 2d and IV (Camk2d, CamkIV) transcripts during 3-isobutyl-1-methylxanthine (IBMX) treatment than in normal INS-1 cells, indicating a crucial influence of melatonin receptor density on transcript-level regulation. In addition, melatonin induced a significant downregulation of calmodulin (Calm1) in IBMX-treated hMT2-INS-1 cells. Long-term administration of melatonin alone reduced CamkIV transcript levels in INS-1 cells; however, transcript levels of Camk2d remained unchanged. The release of insulin was diminished under long-term melatonin treatment. The impact of melatonin also involved reductions in CAMK2D protein during IBMX or forskolin treatments in INS-1 cells, as measured by an enzyme-linked immunosorbent assay, indicating a functional significance of transcriptional changes in pancreatic islets. Furthermore, analysis of melatonin receptor knockout mice showed that the transcript levels of Camk2d, CamkIV, and Calm1 were differentially influenced according to the melatonin receptor subtype deleted. In conclusion, this study provides evidence that melatonin has different impacts on the regulation of Calm1 and Camk. These calcium-signaling components are known as participants in the calcium/calmodulin pathway, which plays an important functional role in the modulation of the β-cell signaling pathways leading to insulin secretion.
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24
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Barbosa-Sampaio HC, Liu B, Drynda R, Rodriguez de Ledesma AM, King AJ, Bowe JE, Malicet C, Iovanna JL, Jones PM, Persaud SJ, Muller DS. Nupr1 deletion protects against glucose intolerance by increasing beta cell mass. Diabetologia 2013; 56:2477-86. [PMID: 23900510 DOI: 10.1007/s00125-013-3006-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Accepted: 07/05/2013] [Indexed: 01/08/2023]
Abstract
AIMS/HYPOTHESIS The stress-activated nuclear protein transcription regulator 1 (NUPR1) is induced in response to glucose and TNF-α, both of which are elevated in type 2 diabetes, and Nupr1 has been implicated in cell proliferation and apoptosis cascades. We used Nupr1(-/-) mice to study the role of Nupr1 in glucose homeostasis under normal conditions and following maintenance on a high-fat diet (HFD). METHODS Glucose homeostasis in vivo was determined by measuring glucose tolerance, insulin sensitivity and insulin secretion. Islet number, morphology and beta cell area were assessed by immunofluorescence and morphometric analysis, and islet cell proliferation was quantified by analysis of BrdU incorporation. Islet gene expression was measured by gene arrays and quantitative RT-PCR, and gene promoter activities were monitored by measuring luciferase activity. RESULTS Nupr1(-/-) mice had increased beta cell mass as a consequence of enhanced islet cell proliferation. Nupr1-dependent suppression of beta cell Ccna2 and Tcf19 promoter activities was identified as a mechanism through which Nupr1 may regulate beta cell cycle progression. Nupr1(-/-) mice maintained on a normal diet were mildly insulin resistant, but were normoglycaemic with normal glucose tolerance because of compensatory increases in basal and glucose-induced insulin secretion. Nupr1 deletion was protective against HFD-induced obesity, insulin resistance and glucose intolerance. CONCLUSIONS/INTERPRETATION Inhibition of NUPR1 expression or activity has the potential to protect against the metabolic defects associated with obesity and type 2 diabetes.
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Affiliation(s)
- Helena C Barbosa-Sampaio
- Diabetes Research Group, Division of Diabetes and Nutritional Sciences, School of Medicine, King's College London, 2.9N Hodgkin Building, Guy's Campus, London, SE1 1UL, UK
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25
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Liu B, Hassan Z, Amisten S, King AJ, Bowe JE, Huang GC, Jones PM, Persaud SJ. The novel chemokine receptor, G-protein-coupled receptor 75, is expressed by islets and is coupled to stimulation of insulin secretion and improved glucose homeostasis. Diabetologia 2013; 56:2467-76. [PMID: 23979485 DOI: 10.1007/s00125-013-3022-x] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Accepted: 07/19/2013] [Indexed: 01/14/2023]
Abstract
AIMS/HYPOTHESIS Chemokine (C-C motif) ligand 5 (CCL5) acts at C-C chemokine receptors (CCRs) to promote immune cell recruitment to sites of inflammation, but is also an agonist at G-protein-coupled receptor 75 (GPR75), which has very limited homology with CCRs. GPR75 is coupled to Gq to elevate intracellular calcium, so we investigated whether islets express this receptor and whether its activation by CCL5 increases beta cell calcium levels and insulin secretion. METHODS Islet CCL5 receptor mRNA expression was measured by quantitative RT-PCR and GPR75 was detected in islets by western blotting and immunohistochemistry. In some experiments GPR75 was downregulated by transient transfection with small interfering RNA. Real-time changes in intracellular calcium were determined by single-cell microfluorimetry. Dynamic insulin secretion from perifused islets was quantified by radioimmunoassay. Glucose homeostasis in lean and obese mice was determined by measuring glucose and insulin tolerance, and insulin secretion in vivo. RESULTS Mouse and human islets express GPR75 and its ligand CCL5. Exogenous CCL5 reversibly increased intracellular calcium in beta cells via GPR75, this phenomenon being dependent on phospholipase C activation and calcium influx. CCL5 also stimulated insulin secretion from mouse and human islets in vitro, and improved glucose tolerance in lean mice and in a mouse model of hyperglycaemia and insulin resistance (ob/ob). The improvement in glucose tolerance was associated with enhanced insulin secretion in vivo, without changes in insulin sensitivity. CONCLUSIONS/INTERPRETATION Although CCL5 is implicated in the pathogenesis of diabetes through activation of CCRs, it has beneficial effects on beta cells through GPR75 activation.
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Affiliation(s)
- Bo Liu
- Diabetes Research Group, Division of Diabetes & Nutritional Sciences, School of Medicine, 2.9N Hodgkin Building, King's College London, Guy's Campus, London, SE1 1UL, UK
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26
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Bowe JE, Chander A, Liu B, Persaud SJ, Jones PM. The permissive effects of glucose on receptor-operated potentiation of insulin secretion from mouse islets: a role for ERK1/2 activation and cytoskeletal remodelling. Diabetologia 2013; 56:783-91. [PMID: 23344729 DOI: 10.1007/s00125-012-2828-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2012] [Accepted: 12/13/2012] [Indexed: 10/27/2022]
Abstract
AIMS/HYPOTHESIS Glucose plays two distinct roles in regulating insulin secretion from beta cells--an initiatory role, and a permissive role enabling receptor-operated secretagogues to potentiate glucose-induced insulin secretion. The molecular mechanisms underlying the permissive effects of glucose on receptor-operated insulin secretion remain uncertain. We have investigated the role of extracellular signal-regulated kinase 1/2 (ERK1/2) activation and consequent cytoskeletal remodelling in this process. METHODS Insulin release was measured from groups of isolated mouse islets using static incubation experiments and subsequent radioimmunoassay of samples. ERK1/2 activation was measured by western blotting of islet protein samples for both phosphorylated and total ERK1/2. Rhodamine-phalloidin staining was used to measure filamentous actin in dispersed primary beta cells. RESULTS Inhibition of ERK1/2 blocked potentiation of glucose-induced insulin release by the receptor-operated secretagogues kisspeptin, A568, exendin-4 and JWH015, although the agonists alone had minimal effects on ERK1/2 activation, suggesting a permissive rather than causal role for ERK1/2 activation in receptor-operated insulin release. Following pharmacological activation of ERK1/2 all agonists caused a significant increase in insulin release from islets incubated with sub-stimulatory levels of glucose. ERK1/2 inhibition significantly reduced the glucose-dependent decreases in filamentous actin observed in primary beta cells, while pharmacological dissociation of actin filaments enabled all receptor-operated secretagogues tested to significantly stimulate insulin release from islets at a sub-stimulatory glucose concentration. CONCLUSIONS/INTERPRETATION Glucose-induced ERK1/2 activation in beta cells mediates the permissive effects of stimulatory glucose concentrations on receptor-operated insulin secretagogues, at least in part through effects on actin depolymerisation and cytoskeletal remodelling.
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Affiliation(s)
- J E Bowe
- Diabetes Research Group, Division of Diabetes and Nutritional Sciences, Hodgkin Building, King's College London, London SE1 1UL, UK.
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27
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Sathanoori R, Olde B, Erlinge D, Göransson O, Wierup N. Cocaine- and amphetamine-regulated transcript (CART) protects beta cells against glucotoxicity and increases cell proliferation. J Biol Chem 2012; 288:3208-18. [PMID: 23250745 DOI: 10.1074/jbc.m112.437145] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Cocaine- and amphetamine-regulated transcript (CART) is an islet peptide that promotes glucose-stimulated insulin secretion in beta cells via cAMP/PKA-dependent pathways. In addition, CART is a regulator of neuronal survival. In this study, we examined the effect of exogenous CART 55-102 on beta cell viability and dissected its signaling mechanisms. Evaluation of DNA fragmentation and chromatin condensation revealed that CART 55-102 reduced glucotoxicity-induced apoptosis in both INS-1 (832/13) cells and isolated rat islets. Glucotoxicity in INS-1 (832/13) cells also caused a 50% reduction of endogenous CART protein. We show that CART increased proliferation in INS-1 (832/13) cells, an effect that was blocked by PKA, PKB, and MEK1 inhibitors. In addition, CART induced phosphorylation of CREB, IRS, PKB, FoxO1, p44/42 MAPK, and p90RSK in INS-1 (832/13) cells and isolated rat islets, all key mediators of cell survival and proliferation. Thus, we demonstrate that CART 55-102 protects beta cells against glucotoxicity and promotes proliferation. Taken together our data point to the potential use of CART in therapeutic interventions targeted at enhancing functional beta cell mass and long-term insulin secretion in T2D.
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28
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Liu B, Barbosa-Sampaio H, Jones PM, Persaud SJ, Muller DS. The CaMK4/CREB/IRS-2 cascade stimulates proliferation and inhibits apoptosis of β-cells. PLoS One 2012; 7:e45711. [PMID: 23049845 PMCID: PMC3458088 DOI: 10.1371/journal.pone.0045711] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Accepted: 08/23/2012] [Indexed: 01/09/2023] Open
Abstract
Progressive reduction in β-cell mass is responsible for the development of type 2 diabetes mellitus, and alteration in insulin receptor substrate 2 (IRS-2) abundance plays a critical role in this process. IRS-2 expression is stimulated by the transcription factor cAMP response element-binding protein (CREB) and we recently demonstrated that Ca2+/calmodulin dependent kinase 4 (CaMK4) is upstream of CREB activation in β-cells. This study investigated whether CaMK4 is also a potential target to increase β-cell mass through CREB-mediated IRS-2 expression, by quantifying mouse MIN6 β-cell proliferation and apoptosis following IRS-2 knockdown, CaMKs inhibition and alterations in CaMK4 and CREB expression. Expression of constitutively active CaMK4 (ΔCaMK4) and CREB (CREBDIEDLM) significantly stimulated β-cell proliferation and survival. In contrast, expression of their corresponding dominant negative forms (ΔK75ECaMK4 and CREBM1) and silencing of IRS-2 increased apoptosis and reduced β-cell division. Moreover, CREBDIEDLM and CREBM1 expression completely abolished the effects of ΔK75ECaMK4 and of ΔCaMK4, respectively. Our results indicate that CaMK4 regulates β-cell proliferation and apoptosis in a CREB-dependent manner and that CaMK4-induced IRS-2 expression is important in these processes.
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Affiliation(s)
- Bo Liu
- Diabetes Research Group, School of Medicine, Division of Diabetes & Nutritional Sciences, King’s College London, London, United Kingdom
| | - Helena Barbosa-Sampaio
- Diabetes Research Group, School of Medicine, Division of Diabetes & Nutritional Sciences, King’s College London, London, United Kingdom
| | - Peter M. Jones
- Diabetes Research Group, School of Medicine, Division of Diabetes & Nutritional Sciences, King’s College London, London, United Kingdom
| | - Shanta J. Persaud
- Diabetes Research Group, School of Medicine, Division of Diabetes & Nutritional Sciences, King’s College London, London, United Kingdom
- * E-mail:
| | - Dany S. Muller
- Diabetes Research Group, School of Medicine, Division of Diabetes & Nutritional Sciences, King’s College London, London, United Kingdom
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29
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Johnston-Cox H, Koupenova M, Yang D, Corkey B, Gokce N, Farb MG, LeBrasseur N, Ravid K. The A2b adenosine receptor modulates glucose homeostasis and obesity. PLoS One 2012; 7:e40584. [PMID: 22848385 PMCID: PMC3405065 DOI: 10.1371/journal.pone.0040584] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2012] [Accepted: 06/09/2012] [Indexed: 02/06/2023] Open
Abstract
Background High fat diet and its induced changes in glucose homeostasis, inflammation and obesity continue to be an epidemic in developed countries. The A2b adenosine receptor (A2bAR) is known to regulate inflammation. We used a diet-induced obesity murine knockout model to investigate the role of this receptor in mediating metabolic homeostasis, and correlated our findings in obese patient samples. Methodology/Principal Findings Administration of high fat, high cholesterol diet (HFD) for sixteen weeks vastly upregulated the expression of the A2bAR in control mice, while A2bAR knockout (KO) mice under this diet developed greater obesity and hallmarks of type 2 diabetes (T2D), assessed by delayed glucose clearance and augmented insulin levels compared to matching control mice. We identified a novel link between the expression of A2bAR, insulin receptor substrate 2 (IRS-2), and insulin signaling, determined by Western blotting for IRS-2 and tissue Akt phosphorylation. The latter is impaired in tissues of A2bAR KO mice, along with a greater inflammatory state. Additional mechanisms involved include A2bAR regulation of SREBP-1 expression, a repressor of IRS-2. Importantly, pharmacological activation of the A2bAR by injection of the A2bAR ligand BAY 60-6583 for four weeks post HFD restores IRS-2 levels, and ameliorates T2D. Finally, in obese human subjects A2bAR expression correlates strongly with IRS-2 expression. Conclusions/Significance Our study identified the A2bAR as a significant regulator of HFD-induced hallmarks of T2D, thereby pointing to its therapeutic potential.
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Affiliation(s)
- Hillary Johnston-Cox
- Departments of Medicine, Boston University School of Medicine, Boston, Massachusetts, United States of America
- Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Milka Koupenova
- Departments of Medicine, Boston University School of Medicine, Boston, Massachusetts, United States of America
- Department Biochemistry, Boston University School of Medicine, Boston, Massachusetts, United States of America
- Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Dan Yang
- Departments of Medicine, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Barbara Corkey
- Departments of Medicine, Boston University School of Medicine, Boston, Massachusetts, United States of America
- Evans Center for Interdisciplinary Biomedical Research, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Noyan Gokce
- Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, Massachusetts, United States of America
- Evans Center for Interdisciplinary Biomedical Research, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Melissa G. Farb
- Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, Massachusetts, United States of America
- Evans Center for Interdisciplinary Biomedical Research, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Nathan LeBrasseur
- Departments of Medicine, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Katya Ravid
- Departments of Medicine, Boston University School of Medicine, Boston, Massachusetts, United States of America
- Department Biochemistry, Boston University School of Medicine, Boston, Massachusetts, United States of America
- Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, Massachusetts, United States of America
- Evans Center for Interdisciplinary Biomedical Research, Boston University School of Medicine, Boston, Massachusetts, United States of America
- * E-mail:
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