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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 2019; 21:1-12. [PMID: 30630689 PMCID: PMC6407368 DOI: 10.1016/j.molmet.2018.12.007] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 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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Bracken C, Beauverger P, Duclos O, Russo RJ, Rogers KA, Husson H, Natoli TA, Ledbetter SR, Janiak P, Ibraghimov-Beskrovnaya O, Bukanov NO. CaMKII as a pathological mediator of ER stress, oxidative stress, and mitochondrial dysfunction in a murine model of nephronophthisis. Am J Physiol Renal Physiol 2016; 310:F1414-22. [PMID: 27076647 DOI: 10.1152/ajprenal.00426.2015] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 04/11/2016] [Indexed: 11/22/2022] Open
Abstract
Polycystic kidney diseases (PKDs) are genetic diseases characterized by renal cyst formation with increased cell proliferation, apoptosis, and transition to a secretory phenotype at the expense of terminal differentiation. Despite recent progress in understanding PKD pathogenesis and the emergence of potential therapies, the key molecular mechanisms promoting cystogenesis are not well understood. Here, we demonstrate that mechanisms including endoplasmic reticulum stress, oxidative damage, and compromised mitochondrial function all contribute to nephronophthisis-associated PKD. Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) is emerging as a critical mediator of these cellular processes. Therefore, we reasoned that pharmacological targeting of CaMKII may translate into effective inhibition of PKD in jck mice. Our data demonstrate that CaMKII is activated within cystic kidney epithelia in jck mice. Blockade of CaMKII with a selective inhibitor results in effective inhibition of PKD in jck mice. Mechanistic experiments in vitro and in vivo demonstrated that CaMKII inhibition relieves endoplasmic reticulum stress and oxidative damage and improves mitochondrial integrity and membrane potential. Taken together, our data support CaMKII inhibition as a new and effective therapeutic avenue for the treatment of cystic diseases.
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Affiliation(s)
- Christina Bracken
- Rare Diseases, Sanofi-Genzyme R&D Center, Framingham, Massachusetts; and
| | | | | | - Ryan J Russo
- Rare Diseases, Sanofi-Genzyme R&D Center, Framingham, Massachusetts; and
| | - Kelly A Rogers
- Rare Diseases, Sanofi-Genzyme R&D Center, Framingham, Massachusetts; and
| | - Hervé Husson
- Rare Diseases, Sanofi-Genzyme R&D Center, Framingham, Massachusetts; and
| | - Thomas A Natoli
- Rare Diseases, Sanofi-Genzyme R&D Center, Framingham, Massachusetts; and
| | - Steven R Ledbetter
- Rare Diseases, Sanofi-Genzyme R&D Center, Framingham, Massachusetts; and
| | - Philip Janiak
- Cardiovascular Research, Sanofi, Chilly-Mazarin, France
| | | | - Nikolay O Bukanov
- Rare Diseases, Sanofi-Genzyme R&D Center, Framingham, Massachusetts; and
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Boric M, Jelicic Kadic A, Puljak L. Cutaneous expression of calcium/calmodulin-dependent protein kinase II in rats with type 1 and type 2 diabetes. J Chem Neuroanat 2014; 61-62:140-6. [PMID: 25266254 DOI: 10.1016/j.jchemneu.2014.09.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2014] [Revised: 09/11/2014] [Accepted: 09/18/2014] [Indexed: 12/11/2022]
Abstract
Changes in calcium-calmodulin protein kinase II (CaMKII) have been well demonstrated in nervous tissue of diabetic animal models. Skin shares the same ectodermal origin as nervous tissue and it is often affected in diabetic patients. The goal of this study was to analyze expression of CaMKII in rat foot pad 2 weeks and 2 months after induction of diabetes type 1 and 2. Forty-two Sprague-Dawley rats were used. Diabetes mellitus type 1 (DM1) was induced with intraperitoneally (i.p.) injected 55 mg/kg of streptozotocin (STZ) and diabetes mellitus type 2 (DM2) with a combination of high-fat diet (HFD) and i.p. injection of low-dose STZ (35 mg/kg). Two weeks and two months following diabetes induction rats were sacrificed and skin samples from plantar surface of the both hind paws were removed. Immunohistochemistry was performed for detection of total CaMKII (tCaMKII) and its alpha isoform (pCaMKIIα). For detection of intraepidermal nerve fibers polyclonal antiserum against protein gene product 9.5 (PGP 9.5) was used. The results showed that CaMKII was expressed in the skin of both diabetic models. Total CaMKII was uniformly distributed throughout the epidermis and pCaMKIIα was limited to stratum granulosum. The tCaMKII and pCaMKIIα were not expressed in intraepidermal nerve fibers. Two weeks after induction of diabetes in rats there were no significant differences in expression of tCaMKII and pCaMKIIα between DM1 and DM2 compared to respective controls. In the 2-month experiments, significant increase in epidermal expression of tCaMKII and pCaMKIIα was observed in DM1 animals compared to controls, but not in DM2 animals. This study is the first description of cutaneous CaMKII expression pattern in a diabetic model. CaMKII could play a role in transformation of skin layers and contribute to cutaneous diabetic changes. Further research on physiological role of CaMKII in skin and its role in cutaneous diabetic complications should be undertaken in order to elucidate its function in epidermis.
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Affiliation(s)
- Matija Boric
- Laboratory for Pain Research, University of Split School of Medicine, Soltanska 2, 21000 Split, Croatia.
| | - Antonia Jelicic Kadic
- Laboratory for Pain Research, University of Split School of Medicine, Soltanska 2, 21000 Split, Croatia
| | - Livia Puljak
- Laboratory for Pain Research, University of Split School of Medicine, Soltanska 2, 21000 Split, Croatia
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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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Dixit SS, Wang T, Manzano EJQ, Yoo S, Lee J, Chiang DY, Ryan N, Respress JL, Yechoor VK, Wehrens XHT. Effects of CaMKII-mediated phosphorylation of ryanodine receptor type 2 on islet calcium handling, insulin secretion, and glucose tolerance. PLoS One 2013; 8:e58655. [PMID: 23516528 PMCID: PMC3596297 DOI: 10.1371/journal.pone.0058655] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Accepted: 02/07/2013] [Indexed: 11/28/2022] Open
Abstract
Altered insulin secretion contributes to the pathogenesis of type 2 diabetes. This alteration is correlated with altered intracellular Ca2+-handling in pancreatic β cells. Insulin secretion is triggered by elevation in cytoplasmic Ca2+ concentration ([Ca2+]cyt) of β cells. This elevation in [Ca2+]cyt leads to activation of Ca2+/calmodulin-dependent protein kinase II (CAMKII), which, in turn, controls multiple aspects of insulin secretion. CaMKII is known to phosphorylate ryanodine receptor 2 (RyR2), an intracellular Ca2+-release channel implicated in Ca2+-dependent steps of insulin secretion. Our data show that RyR2 is CaMKII phosphorylated in a pancreatic β-cell line in a glucose-sensitive manner. However, it is not clear whether any change in CaMKII-mediated phosphorylation underlies abnormal RyR2 function in β cells and whether such a change contributes to alterations in insulin secretion. Therefore, knock-in mice with a mutation in RyR2 that mimics its constitutive CaMKII phosphorylation, RyR2-S2814D, were studied. This mutation led to a gain-of-function defect in RyR2 indicated by increased basal RyR2-mediated Ca2+ leak in islets of these mice. This chronic in vivo defect in RyR2 resulted in basal hyperinsulinemia. In addition, S2814D mice also developed glucose intolerance, impaired glucose-stimulated insulin secretion and lowered [Ca2+]cyt transients, which are hallmarks of pre-diabetes. The glucose-sensitive Ca2+ pool in islets from S2814D mice was also reduced. These observations were supported by immunohistochemical analyses of islets in diabetic human and mouse pancreata that revealed significantly enhanced CaMKII phosphorylation of RyR2 in type 2 diabetes. Together, these studies implicate that the chronic gain-of-function defect in RyR2 due to CaMKII hyperphosphorylation is a novel mechanism that contributes to pathogenesis of type 2 diabetes.
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Affiliation(s)
- Sayali S. Dixit
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Tiannan Wang
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Eiffel John Q. Manzano
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Shin Yoo
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Jeongkyung Lee
- Diabetes and Endocrinology Research Center and Department of Medicine, Division of Diabetes, Endocrinology, and Metabolism, Baylor College of Medicine, Houston, Texas, United States of America
| | - David Y. Chiang
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Nicole Ryan
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Jonathan L. Respress
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Vijay K. Yechoor
- Diabetes and Endocrinology Research Center and Department of Medicine, Division of Diabetes, Endocrinology, and Metabolism, Baylor College of Medicine, Houston, Texas, United States of America
| | - Xander H. T. Wehrens
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Medicine, Division of Cardiology, Baylor College of Medicine, Houston, Texas, United States of America
- * E-mail:
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Suzuki H, Usui I, Kato I, Oya T, Kanatani Y, Yamazaki Y, Fujisaka S, Senda S, Ishii Y, Urakaze M, Mahmood A, Takasawa S, Okamoto H, Kobayashi M, Tobe K, Sasahara M. Deletion of platelet-derived growth factor receptor-β improves diabetic nephropathy in Ca²⁺/calmodulin-dependent protein kinase IIα (Thr286Asp) transgenic mice. Diabetologia 2011; 54:2953-62. [PMID: 21833587 DOI: 10.1007/s00125-011-2270-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2011] [Accepted: 07/05/2011] [Indexed: 01/28/2023]
Abstract
AIMS/HYPOTHESIS The activation of platelet-derived growth factor receptor-β (PDGFR-β) signalling is increased in the glomeruli and tubules of diabetic animals. In this study, we examined the role of PDGFR-β signalling during the development of diabetic nephropathy. METHODS We recently generated pancreatic beta cell-specific Ca(2+)/calmodulin-dependent protein kinase IIα (Thr286Asp) transgenic mice (CaMKIIα mice), which show very high plasma glucose levels up to 55.5 mmol/l and exhibit the features of diabetic nephropathy. These mice were crossed with conditional knockout mice in which Pdgfr-β (also known as Pdgfrb) was deleted postnatally. The effect of the deletion of the Pdgfr-β gene on diabetic nephropathy in CaMKIIα mice was evaluated at 10 and 16 weeks of age. RESULTS The plasma glucose concentrations and HbA(1c) levels were elevated in the CaMKIIα mice from 4 weeks of age. Variables indicative of diabetic nephropathy, such as an increased urinary albumin/creatinine ratio, kidney weight/body weight ratio and mesangial area/glomerular area ratio, were observed at 16 weeks of age. The postnatal deletion of the Pdgfr-β gene significantly decreased the urinary albumin/creatinine ratio and mesangial area/glomerular area ratio without affecting the plasma glucose concentration. Furthermore, the increased oxidative stress in the kidneys of the CaMKIIα mice as shown by the increased urinary 8-hydroxydeoxyguanosine (8-OHdG) excretion and the increased expression of NAD(P)H oxidase 4 (NOX4), glutathione peroxidase 1 (GPX1) and manganese superoxide dismutase (MnSOD) was decreased by Pdgfr-β gene deletion. CONCLUSIONS/INTERPRETATION The activation of PDGFR-β signalling contributes to the progress of diabetic nephropathy, with an increase in oxidative stress and mesangial expansion in CaMKIIα mice.
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Affiliation(s)
- H Suzuki
- First Department of Internal Medicine, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan
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Kim YH, Kim YS, Park SY, Park CH, Choi WS, Cho GJ. CaMKII regulates pericyte loss in the retina of early diabetic mouse. Mol Cells 2011; 31:289-93. [PMID: 21331776 PMCID: PMC3932701 DOI: 10.1007/s10059-011-0038-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2010] [Revised: 12/30/2010] [Accepted: 02/10/2011] [Indexed: 01/01/2023] Open
Abstract
Inducible nitric oxide synthase (iNOS) is an essential mediator in diabetic vascular lesions and known to be regulated by activation of Ca(2+)/calmodulin-dependent protein kinase II (CaMKII). The aim of this study was to investigate whether CaMKII affects iNOS-mediated pericyte death in the retina of diabetic mice with early stage disease. Total- and phospho-CaMKII, iNOS, and active caspase-3 protein levels were assessed by Western blotting, and CaMKII activity was measured by kinase assay. iNOS-related pericyte death was assessed by double immunofluorescent staining for iNOS and α-smooth muscle actin, followed by the TUNEL assay. Autocamtide-2-related inhibitory peptide (AIP), a specific inhibitor of CaMKII, was injected into the right vitreous 2 days before sacrifice of mice, to examine the effect of CaMKII inactivation in diabetic retinas. The levels of total- and phospho-CaMKII, iNOS, and active caspase-3 protein, and CaMKII activity were significantly increased in the diabetic retinas compared with those of control retinas. Furthermore, TUNEL-positive signals colocalized with iNOS-immunoreactive pericytes in the same retinas. However, inactivation of CaMKII by AIP treatment inhibited all these changes, which was accompanied by less pericyte loss. Our results demonstrate that CaMKII contributes to iNOS-related death of pericytes in the diabetic retina and that inactivation of this enzyme may be a potential treatment for retinal vascular lesion.
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Affiliation(s)
| | | | | | | | - Wan Sung Choi
- Department of Anatomy and Neurobiology, School of Medicine, Brain Korea 21 Biomedical Center, Gyeongsang National University, Jinju 660-751, Korea
| | - Gyeong Jae Cho
- Department of Anatomy and Neurobiology, School of Medicine, Brain Korea 21 Biomedical Center, Gyeongsang National University, Jinju 660-751, Korea
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Current literature in diabetes. Diabetes Metab Res Rev 2009; 25:i-xii. [PMID: 19405078 DOI: 10.1002/dmrr.973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Suzuki H, Kato I, Usui I, Takasaki I, Tabuchi Y, Oya T, Tsuneyama K, Kawaguchi H, Hiraga K, Takasawa S, Okamoto H, Tobe K, Sasahara M. Characterization of diabetic nephropathy in CaM kinase IIα (Thr286Asp) transgenic mice. Biochem Biophys Res Commun 2009; 379:38-42. [DOI: 10.1016/j.bbrc.2008.11.143] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2008] [Accepted: 11/30/2008] [Indexed: 10/21/2022]
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