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Chi Y, Zhang X, Liang D, Wang Y, Cai X, Dong J, Li L, Chi Z. ZnT8 Exerts Anti-apoptosis of Kidney Tubular Epithelial Cell in Diabetic Kidney Disease Through TNFAIP3-NF-κB Signal Pathways. Biol Trace Elem Res 2023; 201:2442-2457. [PMID: 35871203 DOI: 10.1007/s12011-022-03361-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 07/13/2022] [Indexed: 02/05/2023]
Abstract
Apoptosis of kidney tubular epithelial cells contributes to diabetic kidney disease (DKD) pathophysiology, but the mechanisms are not fully understood. Zinc transporter protein member 8 (ZnT8, SLC30A8) is a susceptive gene in diabetes. Here, we aim to investigate whether ZnT8 has effects on pathophysiology of DKD. The animal groups include control, ZnT8KO mice, STZ-induced, and ZnT8-KO-STZ. STZ-induced DKD was performed in male C57BL/6 J mice and in ZnT8-KO mice. High glucose (HG)-induced apoptosis in a normal rat kidney tubular epithelial cell line (NRK-52E cells) was performed in vitro. Transfection of hZnT8-EGFP or TNFAIP3 siRNA was done in NRK-52E cells. Flow cytometry with Annexin V-FITC/PI double staining and TUNEL analysis was performed for the detection of apoptosis. Gene expression at mRNA and protein levels was examined with real-time RT-PCR and Western blot. Urine albumin to creatinine ratio, proinflammatory cytokines, and apoptosis were enhanced in kidneys of STZ and ZnT8-KO-STZ mice compared to control or ZnT8-KO mice. ZnT8 overexpression after hZnT8-EGFP transfection decreased HG-stimulated inflammatory activity and apoptosis in NRK-52E cells. Furthermore, treatment with ZnSO4 blunted HG-induced apoptosis and NF-κB activation. ZnSO4 increased the abundance of zinc-finger protein TNF-α-induced protein 3 (TNFAIP3). Also, ZnT8 over-expression after hZnT8-EGFP transfection significantly ameliorates HG-induced NF-κB-dependent transcriptional activity and apoptotic protein expressions in NRK-52E cells, but the inhibitory effect of ZnT8 was significantly abolished with TNFAIP3 siRNA. Our study provides evidence that ZnT8 has protective effects against apoptosis of renal tubular epithelial cells through induction of TNFAIP3 and subsequent suppression of the NF-κB pathway.
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Affiliation(s)
- Yinmao Chi
- Department of Physiology, China Medical University, Shenyang, Liaoning Province, 110001, People's Republic of China
| | - Xiuli Zhang
- Department of Nephrology, The First Affiliated Hospital of Shenzhen University, Shenzhen Second People's Hospital, Shenzhen, Guangdong Province, 518000, People's Republic of China.
- Department of Nephrology, Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen, Guangdong Province, 518000, People's Republic of China.
| | - Dan Liang
- Troops of 95988 Unit, Changchun, Jilin, 158000, People's Republic of China
| | - Yue Wang
- Department of Tissue Culture, Liaoning University of Traditional Chinese Medicine, Shenyang, Liaoning Province, 110001, People's Republic of China
| | - Xiaoyi Cai
- Department of Nephrology, The First Affiliated Hospital of Shenzhen University, Shenzhen Second People's Hospital, Shenzhen, Guangdong Province, 518000, People's Republic of China
- Shantou University Medical College, Shantou, Guangdong Province, 515000, People's Republic of China
| | - Jiqiu Dong
- Department of Nephrology, The First Affiliated Hospital of Shenzhen University, Shenzhen Second People's Hospital, Shenzhen, Guangdong Province, 518000, People's Republic of China
| | - Lingzhi Li
- Department of Nephrology, The First Affiliated Hospital of Shenzhen University, Shenzhen Second People's Hospital, Shenzhen, Guangdong Province, 518000, People's Republic of China
| | - Zhihong Chi
- Department of Pathophysiology, China Medical University, Shenyang, Liaoning Province, 110001, People's Republic of China
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Barragán-Álvarez CP, Padilla-Camberos E, Díaz NF, Cota-Coronado A, Hernández-Jiménez C, Bravo-Reyna CC, Díaz-Martínez NE. Loss of Znt8 function in diabetes mellitus: risk or benefit? Mol Cell Biochem 2021; 476:2703-2718. [PMID: 33666829 DOI: 10.1007/s11010-021-04114-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 02/18/2021] [Indexed: 12/13/2022]
Abstract
The zinc transporter 8 (ZnT8) plays an essential role in zinc homeostasis inside pancreatic β cells, its function is related to the stabilization of insulin hexameric form. Genome-wide association studies (GWAS) have established a positive and negative relationship of ZnT8 variants with type 2 diabetes mellitus (T2DM), exposing a dual and controversial role. The first hypotheses about its role in T2DM indicated a higher risk of developing T2DM for loss of function; nevertheless, recent GWAS of ZnT8 loss-of-function mutations in humans have shown protection against T2DM. With regard to the ZnT8 role in T2DM, most studies have focused on rodent models and common high-risk variants; however, considerable differences between human and rodent models have been found and the new approaches have included lower-frequency variants as a tool to clarify gene functions, allowing a better understanding of the disease and offering possible therapeutic targets. Therefore, this review will discuss the physiological effects of the ZnT8 variants associated with a major and lower risk of T2DM, emphasizing the low- and rare-frequency variants.
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Affiliation(s)
- Carla P Barragán-Álvarez
- Biotecnología Médica y Farmacéutica, Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco, Guadalajara, Mexico
| | - Eduardo Padilla-Camberos
- Biotecnología Médica y Farmacéutica, Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco, Guadalajara, Mexico
| | - Nestor F Díaz
- Departamento de Fisiología y Desarrollo Celular, Instituto Nacional de Perinatología, Mexico City, Mexico
| | - Agustín Cota-Coronado
- Biotecnología Médica y Farmacéutica, Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco, Guadalajara, Mexico
| | - Claudia Hernández-Jiménez
- Departamento de Cirugía Experimental, Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas, Mexico City, Mexico
| | - Carlos C Bravo-Reyna
- Departamento de Cirugía Experimental, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
| | - Nestor E Díaz-Martínez
- Biotecnología Médica y Farmacéutica, Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco, Guadalajara, Mexico.
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Zhang Y, Yan N, Li Y, Ma WM, Liu HL, Yu JN, Ma L. Association between islet autoantibodies and the prevalence of autoimmune uveitis. Int J Ophthalmol 2020; 13:1733-1738. [PMID: 33215003 DOI: 10.18240/ijo.2020.11.08] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Accepted: 06/30/2020] [Indexed: 11/23/2022] Open
Abstract
AIM To evaluate the predictive value of islet autoantibodies for the diagnosis of autoimmune uveitis (AU), as well as to characterize the association bet ween islet autoantibodies and AU. METHODS Totally 97 patients with AU and 100 healthy persons without any autoimmune diseases as the control group were recruited. Multiple serum islet autoantibodies were measured using commercial enzyme-linked immunosorbent assay kits (ELISA). A supplementary questionnaire was used to complement the subject's demographics and clinical features. The level of glucose concentrations and white blood cells were measured. Conditional logistic regression was performed to estimate odds ratios (ORs), and 95% confidence intervals (CIs) of AU according to islet autoantibodies and to evaluate the predictive value of islet autoantibodies for AU diagnosis. Autoantibodies subgroups and other variables were included into analysis. RESULTS In AU patients, the prevalence of detecting at least one of the autoantibodies was 31.9% (31/97). The most frequent autoantibody was ZnT8A (30.9%), followed by GADA (11.3%), IA-2A (4.1%), ICA (2.1%) and IAA (2.1%). Islet autoantibodies were found to be correlated positively with AU diagnosis [OR (95%CI): 13.86 (3.28, 58.50), P<0.001]. Moreover, Zn-T8A was remarkably correlated with AU diagnosis [OR (95%CI): 6.13 (1.96, 19.17), P<0.001], In contrast, neither GADA nor other islet antibodies (IA-2A, ICA and IAA) showed any association with AU risk under an additive model. CONCLUSION The prevalence of islet antibodies, especially ZnT8A, in patients with AU is higher. Islet antibodies as well as novel biomarkers should be included in routine evaluation at AU and is a valuable biological marker to classify newly-diagnosed uveitis.
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Affiliation(s)
- Yun Zhang
- Xi'an People's Hospital (Xi'an Fourth Hospital), Xi'an 710004, Shaanxi Province, China
| | - Ni Yan
- School of Public Health, Xi'an Jiaotong University, Xi'an 710061, Shaanxi Province, China
| | - Ya Li
- Xi'an People's Hospital (Xi'an Fourth Hospital), Xi'an 710004, Shaanxi Province, China
| | - Wei-Mei Ma
- Xi'an People's Hospital (Xi'an Fourth Hospital), Xi'an 710004, Shaanxi Province, China
| | - Hong-Li Liu
- Xi'an People's Hospital (Xi'an Fourth Hospital), Xi'an 710004, Shaanxi Province, China
| | - Jing-Ni Yu
- Xi'an People's Hospital (Xi'an Fourth Hospital), Xi'an 710004, Shaanxi Province, China
| | - Le Ma
- School of Public Health, Xi'an Jiaotong University, Xi'an 710061, Shaanxi Province, China
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Bossowski A, Stożek K, Rydzewska M, Niklińska W, Gąsowska M, Polnik D, Szalecki M, Mikłosz A, Chabowski A, Reszeć J. Expression of zinc transporter 8 in thyroid tissues from patients with immune and non-immune thyroid diseases. Autoimmunity 2020; 53:376-384. [PMID: 32896170 DOI: 10.1080/08916934.2020.1815194] [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] [Indexed: 10/23/2022]
Abstract
INTRODUCTION Recent studies have revealed the presence of zinc and the expression of zinc transporter (ZnT) family members in most endocrine cell types. It was demonstrated that ZnT family plays an important role in the synthesis and secretion of many hormones. Moreover, recently ZnT8 was described as a newly islet autoantigen in type 1 diabetes. MATERIALS AND METHODS We studied the expression of ZnT8 transporter in thyroid tissues from patients with immune and non-immune thyroid diseases. The study was performed in thyroid tissues after thyroidectomy from patients with thyroid non-toxic nodular goitre (NTNG; n = 17, mean age 15.8 ± 2.2 years) and cases with Graves' disease (n = 20, mean age 15.6 ± 2.8). In our study we investigated the expression of ZnT8 in human thyroid tissues from patients with immune and non-immune thyroid diseases using immunohistochemistry, Western Blot as well as immunofluorescence analyses. To the best of our knowledge, this is the first investigation which identified ZnT8 protein expression in human thyroid tissues, moreover, confirmed by three different laboratory techniques. Results and Conclusions Expression of ZnT8 transporter was identified by immunohistochemistry in the thyroid tissues from paediatric patients with Graves' disease (on +++) and non-toxic nodular goitre (on ++). ZnT8 transporter expression was found both in thyroid follicular cells (within the cytoplasm and cytoplasmic membrane in follicular cells) and C cells (membrane-cytoplasmic reaction) in fluorescence. Predominant expression of ZnT8 in band 41 kDa in immune than in non-immune thyroid disorders may suggest potential role of ZnT8 as a new thyroid autoanitgen but it requires further study on a larger cohort.
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Affiliation(s)
- Artur Bossowski
- Department of Pediatrics, Endocrinology and Diabetes with a Cardiology Unit, Medical University of Bialystok, Bialystok, Poland
| | - Karolina Stożek
- Department of Pediatrics, Endocrinology and Diabetes with a Cardiology Unit, Medical University of Bialystok, Bialystok, Poland
| | - Marta Rydzewska
- Department of Pediatrics, Endocrinology and Diabetes with a Cardiology Unit, Medical University of Bialystok, Bialystok, Poland
| | - Wiesława Niklińska
- Department of Histology and Embryology, Medical University of Bialystok, Bialystok, Poland
| | - Marta Gąsowska
- Department of Histology and Embryology, Medical University of Bialystok, Bialystok, Poland
| | - Dariusz Polnik
- Department of Children's Surgery and Transplantology, Children's Memorial Health Institute, Warsaw, Poland
| | - Mieczysław Szalecki
- Department of Pediatric Endocrinology and Diabetology, Children's Memorial Health Institute, Warsaw, Poland
| | - Agnieszka Mikłosz
- Department of Physiology, Medical University of Bialystok, Bialystok, Poland
| | - Adrian Chabowski
- Department of Physiology, Medical University of Bialystok, Bialystok, Poland
| | - Joanna Reszeć
- Department of Medical Patomorphology, Medical University of Bialystok, Bialystok, Poland
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Syring KE, Bosma KJ, Goleva SB, Singh K, Oeser JK, Lopez CA, Skaar EP, McGuinness OP, Davis LK, Powell DR, O’Brien RM. Potential positive and negative consequences of ZnT8 inhibition. J Endocrinol 2020; 246:189-205. [PMID: 32485672 PMCID: PMC7351606 DOI: 10.1530/joe-20-0138] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 06/02/2020] [Indexed: 12/31/2022]
Abstract
SLC30A8 encodes the zinc transporter ZnT8. SLC30A8 haploinsufficiency protects against type 2 diabetes (T2D), suggesting that ZnT8 inhibitors may prevent T2D. We show here that, while adult chow fed Slc30a8 haploinsufficient and knockout (KO) mice have normal glucose tolerance, they are protected against diet-induced obesity (DIO), resulting in improved glucose tolerance. We hypothesize that this protection against DIO may represent one mechanism whereby SLC30A8 haploinsufficiency protects against T2D in humans and that, while SLC30A8 is predominantly expressed in pancreatic islet beta cells, this may involve a role for ZnT8 in extra-pancreatic tissues. Consistent with this latter concept we show in humans, using electronic health record-derived phenotype analyses, that the 'C' allele of the non-synonymous rs13266634 SNP, which confers a gain of ZnT8 function, is associated not only with increased T2D risk and blood glucose, but also with increased risk for hemolytic anemia and decreased mean corpuscular hemoglobin (MCH). In Slc30a8 KO mice, MCH was unchanged but reticulocytes, platelets and lymphocytes were elevated. Both young and adult Slc30a8 KO mice exhibit a delayed rise in insulin after glucose injection, but only the former exhibit increased basal insulin clearance and impaired glucose tolerance. Young Slc30a8 KO mice also exhibit elevated pancreatic G6pc2 gene expression, potentially mediated by decreased islet zinc levels. These data indicate that the absence of ZnT8 results in a transient impairment in some aspects of metabolism during development. These observations in humans and mice suggest the potential for negative effects associated with T2D prevention using ZnT8 inhibitors.
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Affiliation(s)
- Kristen E. Syring
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine
| | - Karin J. Bosma
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine
| | - Slavina B. Goleva
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232
| | - Kritika Singh
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232
| | - James K. Oeser
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine
| | - Christopher A. Lopez
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232
| | - Eric P. Skaar
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232
| | - Owen P. McGuinness
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine
| | - Lea K. Davis
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232
| | - David R. Powell
- Lexicon Pharmaceuticals Incorporated, 8800 Technology Forest Place, The Woodlands, Texas 77381
| | - Richard M. O’Brien
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine
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Zhang X, Guan T, Yang B, Gu HF, Chi Z. Effects of ZnT8 on epithelial-to-mesenchymal transition and tubulointerstitial fibrosis in diabetic kidney disease. Cell Death Dis 2020; 11:544. [PMID: 32681069 PMCID: PMC7367835 DOI: 10.1038/s41419-020-2731-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 06/21/2020] [Accepted: 06/25/2020] [Indexed: 12/31/2022]
Abstract
Zinc transporter 8 (ZnT8) transports zinc ions for crystallization and storage of insulin in pancreatic beta-cells and ZnT8 dysfunction is involved in pathogenesis of diabetes. The current study aimed to investigate whether ZnT8 has effects in pathophysiology of diabetic kidney disease (DKD) by using animal models for diabetes, including STZ-induced diabetic, db/db, ZnT8-KO, ZnT8-KO-STZ and ZnT8-KO-db/db mice. Results demonstrated that urine albumin to creatinine ratio and epithelial-to-mesenchymal transition (EMT) were increased in kidneys of ZnT8-KO-STZ and ZnT8-KO-db/db mice compared with C57BL/6 J and ZnT8-KO mice, while serum TGF-β1, IL-6, and TNF-α levels were elevated in parallel. In kidneys of mice intercrossed between ZnT8-KO and STZ-induced diabetic or db/db mice, these three inflammatory factors, ACR and EMT were also found to be increased compared with C57BL/6J, db/db and ZnT8-KO mice. Furthermore, ZnT8 up-regulation by hZnT8-EGFP reduced the levels of high glucose (HG)-induced EMT and inflammatory factors in normal rat kidney tubular epithelial cell (NRK-52E cells). Expression of phosphorylated Smad2/Smad3 was up-regulated after HG stimulation and further enhanced by ZnT8 siRNA but down-regulated after hZnT8-EGFP gene transfection. The current study thus provides the first evidence that ZnT8 protects against EMT-tubulointerstitial fibrosis though the restrain of TGF-β1/Smads signaling activation in DKD.
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Affiliation(s)
- Xiuli Zhang
- Department of Nephrology, Second People's Hospital, The First Affiliated Hospital of Shenzhen University, 518000, Shenzhen, Guangdong Province, P.R. China.,Department of Pathophysiology, China Medical University, 110001, Shenyang, Liaoning Province, P.R. China
| | - Tingwen Guan
- Department of Pathophysiology, China Medical University, 110001, Shenyang, Liaoning Province, P.R. China
| | - Boxuan Yang
- Department of Pathophysiology, China Medical University, 110001, Shenyang, Liaoning Province, P.R. China
| | - Harvest F Gu
- Center for Pathophysiology, School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, 210009, Nanjing, Jiangsu Province, P.R. China.
| | - Zhihong Chi
- Department of Pathophysiology, China Medical University, 110001, Shenyang, Liaoning Province, P.R. China.
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Expression of concern: Zinc transporter 8 (ZnT8) expression is reduced by ischemic insults: A potential therapeutic target to prevent ischemic retinopathy. PLoS One 2019; 14:e0227390. [PMID: 31881073 PMCID: PMC6934313 DOI: 10.1371/journal.pone.0227390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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ZnT8 Haploinsufficiency Impacts MIN6 Cell Zinc Content and β-Cell Phenotype via ZIP-ZnT8 Coregulation. Int J Mol Sci 2019; 20:ijms20215485. [PMID: 31690008 PMCID: PMC6861948 DOI: 10.3390/ijms20215485] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 10/28/2019] [Accepted: 10/29/2019] [Indexed: 01/17/2023] Open
Abstract
The zinc transporter ZnT8 (SLC30A8) localises to insulin secretory granules of β-cells where it facilitates zinc uptake for insulin crystallisation. ZnT8 abundance has been linked to β-cell survival and functional phenotype. However, the consequences of ZnT8 haploinsufficiency for β-cell zinc trafficking and function remain unclear. Since investigations in human populations have shown SLC30A8 truncating polymorphisms to decrease the risk of developing Type 2 Diabetes, we hypothesised that ZnT8 haploinsufficiency would improve β-cell function and maintain the endocrine phenotype. We used CRISPR/Cas9 technology to generate ZnT8 haploinsufficient mouse MIN6 β-cells and showed that ZnT8 haploinsufficiency is associated with downregulation of mRNAs for Slc39a8 and Slc39a14, which encode for the zinc importers, Znt- and Irt-related proteins 8 (ZIP8) and 14 (ZIP14), and with lowered total cellular zinc content. ZnT8 haploinsufficiency disrupts expression of a distinct array of important β-cell markers, decreases cellular proliferation via mitogen-activated protein (MAP) kinase cascades and downregulates insulin gene expression. Thus, ZnT8 cooperates with zinc importers of the ZIP family to maintain β-cell zinc homeostasis. In contrast to the hypothesis, lowered ZnT8 expression reduces MIN6 cell survival by affecting zinc-dependent transcription factors that control the β-cell phenotype.
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Broadgate S, Kiire C, Halford S, Chong V. Diabetic macular oedema: under-represented in the genetic analysis of diabetic retinopathy. Acta Ophthalmol 2018; 96 Suppl A111:1-51. [PMID: 29682912 DOI: 10.1111/aos.13678] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 11/21/2017] [Indexed: 12/15/2022]
Abstract
Diabetic retinopathy, a complication of both type 1 and type 2 diabetes, is a complex disease and is one of the leading causes of blindness in adults worldwide. It can be divided into distinct subclasses, one of which is diabetic macular oedema. Diabetic macular oedema can occur at any time in diabetic retinopathy and is the most common cause of vision loss in patients with type 2 diabetes. The purpose of this review is to summarize the large number of genetic association studies that have been performed in cohorts of patients with type 2 diabetes and published in English-language journals up to February 2017. Many of these studies have produced positive associations with gene polymorphisms and diabetic retinopathy. However, this review highlights that within this large body of work, studies specifically addressing a genetic association with diabetic macular oedema, although present, are vastly under-represented. We also highlight that many of the studies have small patient numbers and that meta-analyses often inappropriately combine patient data sets. We conclude that there will continue to be conflicting results and no meaningful findings will be achieved if the historical approach of combining all diabetic retinopathy disease states within patient cohorts continues in future studies. This review also identifies several genes that would be interesting to analyse in large, well-defined cohorts of patients with diabetic macular oedema in future candidate gene association studies.
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Affiliation(s)
- Suzanne Broadgate
- Nuffield Laboratory of Ophthalmology; Nuffield Department of Clinical Neurosciences; University of Oxford; Oxford UK
| | - Christine Kiire
- Nuffield Laboratory of Ophthalmology; Nuffield Department of Clinical Neurosciences; University of Oxford; Oxford UK
- Oxford Eye Hospital; John Radcliffe Hospital; Oxford University NHS Foundation Trust; Oxford UK
| | - Stephanie Halford
- Nuffield Laboratory of Ophthalmology; Nuffield Department of Clinical Neurosciences; University of Oxford; Oxford UK
| | - Victor Chong
- Nuffield Laboratory of Ophthalmology; Nuffield Department of Clinical Neurosciences; University of Oxford; Oxford UK
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Udechukwu MC, Collins SA, Udenigwe CC. Prospects of enhancing dietary zinc bioavailability with food-derived zinc-chelating peptides. Food Funct 2018; 7:4137-4144. [PMID: 27713952 DOI: 10.1039/c6fo00706f] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Zinc is an essential micronutrient that strongly influences human health and nutrition through its involvement in several biological processes. Zinc functions as structural and functional component of many transcription factors and enzymes that regulate cell growth, gene expression, and immune response, and its deficiency can lead to retarded growth and impaired immune functions. The physiological functions of zinc are dependent on its bioavailability in tissues, which in turn depends on intestinal absorption of dietary zinc. The presence of dietary fibre and phytates impedes intestinal zinc absorption, as they can form insoluble complexes with zinc, decreasing its bioavailability. Peptides derived from food proteins can enhance zinc absorption and bioavailability. Peptides that contain amino acid residues such as cysteine, histidine, serine, aspartate and glutamate can chelate divalent metals, including zinc, forming soluble metal coordinate complexes. The structure-function relationship of zinc-chelating peptides and the stability of the peptide-metal complexes to gastrointestinal digestion are critical to their relevance in human nutrition and health promotion.
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Affiliation(s)
- M Chinonye Udechukwu
- Department of Plant, Food, and Environmental Sciences, Faculty of Agriculture, Dalhousie University, Truro, Nova Scotia B2N 5E3, Canada.
| | - Stephanie A Collins
- Department of Plant, Food, and Environmental Sciences, Faculty of Agriculture, Dalhousie University, Truro, Nova Scotia B2N 5E3, Canada.
| | - Chibuike C Udenigwe
- Department of Plant, Food, and Environmental Sciences, Faculty of Agriculture, Dalhousie University, Truro, Nova Scotia B2N 5E3, Canada. and School of Nutrition Sciences, Faculty of Health Sciences, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada
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Bodiga VL, Thokala S, Kovur SM, Bodiga S. Zinc Dyshomeostasis in Cardiomyocytes after Acute Hypoxia/Reoxygenation. Biol Trace Elem Res 2017; 179:117-129. [PMID: 28181174 DOI: 10.1007/s12011-017-0957-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 01/30/2017] [Indexed: 02/06/2023]
Abstract
Zinc dyshomeostasis may play a role in the pathogenesis of myocardial ischemia/reperfusion injury. The objective of this study was to investigate the expression profile of zinc regulated transporter like- and iron-regulated transporter-like proteins (ZIPs) and zinc transporter proteins (ZnTs) in cardiomyocytes and their modulation in response to hypoxia and reoxygenation. Adult rat ventricular myocytes (ARVMs) were subjected to 6 h of hypoxia, followed by 18 h of reoxygenation. Intracellular and extracellular zinc concentrations were determined using Fluozin-3 and Newport Green fluorescence, respectively. Expression of ZnTs 1, 2, 5, and 9 along with ZIPs 1, 2, 3, 6, 7, 9, 10, 11, 13, and 14 was detectable in the cardiomyocytes by real-time reverse transcriptase polymerase chain reaction. Hypoxia elicited accumulation of intracellular free zinc, but subsequent reoxygenation resulted in striking loss of intracellular free zinc and decreased the cardiomyocyte viability. Concomitantly, extracellular zinc levels dropped rapidly during hypoxia, but increased after reoxygenation. Immunoblotting analysis revealed that hypoxia increased the expression of ZnT1, but reoxygenation significantly increased the expression of ZnTs 2 and 5. Neither hypoxia nor reoxygenation altered the levels of ZnT9. Increased intracellular zinc at the end of hypoxia is related to enhanced expression of ZIPs, whereas decreased intracellular zinc during reoxygenation appears to be due to lowered expression of all ZIPs, in addition to elevated levels of ZnTs 2 and 5. These results thus suggest that there is impaired accumulation of intracellular zinc during reoxygenation, due to overexpression of specific ZnTs and downregulation of ZIP expression.
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Affiliation(s)
- Vijaya Lakshmi Bodiga
- Institute of Genetics & Hospital for Genetic Diseases, Begumpet, Osmania University, Hyderabad, Telangana, 500016, India
| | - Sandhya Thokala
- Department of Biochemistry, Kakatiya University, Warangal, Telangana, 506009, India
| | - Sita Mahalaxmi Kovur
- Institute of Genetics & Hospital for Genetic Diseases, Begumpet, Osmania University, Hyderabad, Telangana, 500016, India
| | - Sreedhar Bodiga
- Department of Biochemistry, Kakatiya University, Warangal, Telangana, 506009, India.
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Abstract
Islet autoantibodies are the main markers of pancreatic autoimmunity in type 1 diabetes (T1D). Islet autoantibodies recognize insulin (IAA), glutamic acid decarboxylase (GADA), protein phosphatase-like IA-2 (IA-2A), and ZnT8 (ZnT8A), all antigens that are found on secretory granules within pancreatic beta cells. Islet antibodies, measured by sensitive and specific liquid phase assays, are the key parameters of the autoimmune response monitored for diagnostics or prognostics in patients with T1D or for disease prediction in at-risk individuals before T1D onset. Islet autoantibodies have been the main tool used to explore the natural history of T1D; this review summarizes the current knowledge about the autoantigens and the phenotype of islets autoantibodies acquired in large prospective studies from birth in children at risk of developing T1D.
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Affiliation(s)
- Vito Lampasona
- Division of Genetics and Cell Biology, IRCCS San Raffaele Scientific Institute, via Olgettina 60, 20132, Milano, Italy.
- Diabetes Research Institute, IRCCS San Raffaele Scientific Institute, via Olgettina 60, 20132, Milano, Italy.
| | - Daniela Liberati
- Division of Genetics and Cell Biology, IRCCS San Raffaele Scientific Institute, via Olgettina 60, 20132, Milano, Italy
- Diabetes Research Institute, IRCCS San Raffaele Scientific Institute, via Olgettina 60, 20132, Milano, Italy
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Yin XF, Jiang LB, Ma YQ, Xu J, Gu HJ, Wu XH, Li XL, Dong J. Decreased Zn(2+) Influx Underlies the Protective Role of Hypoxia in Rat Nucleus Pulposus Cells. Biol Trace Elem Res 2015; 168:196-205. [PMID: 25910898 DOI: 10.1007/s12011-015-0335-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Accepted: 04/06/2015] [Indexed: 01/08/2023]
Abstract
Zn(2+) is an essential component of metalloproteinases, and is required for their activity in cartilage; however, the effect of Zn(2+) on nucleus pulposus (NP) cells has not been widely investigated. The aim of this paper was to investigate the effect of intracellular Zn(2+) concentration ([Zn(2+)]i) in hypoxia-induced regulation of metalloproteinases (MMPs) and extracellular matrix (ECM) production in NP cells. NP cells from Sprague-Dawley (SD) rats were cultured as monolayers or in alginate beads. [Zn(2+)]i was assayed by FluoZin-3 AM staining. Alcian Blue staining, immunochemistry, 1,9-dimethylmethylene blue (DMMB) assay, and real-time PCR were used to assay collagen II, proteoglycan, and COL2A1, MMP-13, and ADAMTS-5 mRNA expression. ZIP8, a main Zn(2+) transporter in chondrocytes, was assayed by immunochemistry and in Western blotting. Interleukin (IL)-1β- and ZnCl2-induced increases of [Zn(2+)]i were significantly inhibited by hypoxia. Hypoxia did not reverse a decline of ECM expression caused by IL-1β and ZnCl2 in monolayer cultures, but did significantly attenuate the decreases of proteoglycan, glycosaminoglycan (GAG), and COL2A1 mRNA expression following IL-1β and ZnCl2 treatment in alginate bead cultures. However, ZnCl2 inhibited the protective effect of hypoxia. Both an intracellular Zn(2+) chelator and hypoxia prevented the increase in MMP-13 mRNA expression. IL-1β and ZnCl2 treatment increased ZIP8 expression in NP cells, and hypoxia inhibited ZIP8 expression. In conclusion, decrease of Zn(2+) influx mediates the protective role of hypoxia on ECM and MMP-13 expression. Consequently, changes in intracellular Zn(2+) concentration maybe involved in intervertebral disc degeneration.
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Affiliation(s)
- Xiao-Fan Yin
- Department of Orthopedic Surgery, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China
- Department of Orthopedic Surgery, Minhang Hospital, Fudan University, Shanghai, China
| | - Li-Bo Jiang
- Department of Orthopedic Surgery, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China
| | - Yi-Qun Ma
- Department of Orthopedic Surgery, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China
| | - Jun Xu
- Department of Orthopedic Surgery, Minhang Hospital, Fudan University, Shanghai, China
| | - Hui-Jie Gu
- Department of Orthopedic Surgery, Minhang Hospital, Fudan University, Shanghai, China
| | - Xu-Hua Wu
- Department of Orthopedic Surgery, Minhang Hospital, Fudan University, Shanghai, China
| | - Xi-Lei Li
- Department of Orthopedic Surgery, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China.
| | - Jian Dong
- Department of Orthopedic Surgery, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China.
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Somboonwong J, Traisaeng S, Saguanrungsirikul S. Moderate-intensity exercise training elevates serum and pancreatic zinc levels and pancreatic ZnT8 expression in streptozotocin-induced diabetic rats. Life Sci 2015; 139:46-51. [DOI: 10.1016/j.lfs.2015.08.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Revised: 07/16/2015] [Accepted: 08/01/2015] [Indexed: 01/17/2023]
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15
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Pinna A, Masala S, Blasetti F, Maiore I, Cossu D, Paccagnini D, Mameli G, Sechi LA. Detection of serum antibodies cross-reacting with Mycobacterium avium subspecies paratuberculosis and beta-cell antigen zinc transporter 8 homologous peptides in patients with high-risk proliferative diabetic retinopathy. PLoS One 2014; 9:e107802. [PMID: 25226393 PMCID: PMC4166466 DOI: 10.1371/journal.pone.0107802] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Accepted: 08/13/2014] [Indexed: 12/15/2022] Open
Abstract
Purpose MAP3865c, a Mycobacterium avium subspecies paratuberculosis (MAP) cell membrane protein, has a relevant sequence homology with zinc transporter 8 (ZnT8), a beta-cell membrane protein involved in Zn++ transportation. Recently, antibodies recognizing MAP3865c epitopes have been shown to cross-react with ZnT8 in type 1 diabetes patients. The purpose of this study was to detect antibodies against MAP3865c peptides in patients with high-risk proliferative diabetic retinopathy and speculate on whether they may somehow be involved in the pathogenesis of this severe retinal disorder. Methods Blood samples were obtained from 62 type 1 and 80 type 2 diabetes patients with high-risk proliferative diabetic retinopathy and 81 healthy controls. Antibodies against 6 highly immunogenic MAP3865c peptides were detected by indirect ELISA. Results Type 1 diabetes patients had significantly higher rates of positive antibodies than controls. Conversely, no statistically significant differences were found between type 2 diabetes patients and controls. After categorization of type 1 diabetes patients into two groups, one with positive, the other with negative antibodies, we found that they had similar mean visual acuity (∼0.6) and identical rates of vitreous hemorrhage (28.6%). Conversely, Hashimoto's thyroiditis prevalence was 4/13 (30.7%) in the positive antibody group and 1/49 (2%) in the negative antibody group, a statistically significant difference (P = 0.016). Conclusions This study confirmed that type 1 diabetes patients have significantly higher rates of positive antibodies against MAP/ZnT8 peptides, but failed to find a correlation between the presence of these antibodies and the severity degree of high-risk proliferative diabetic retinopathy. The significantly higher prevalence of Hashimoto's disease among type 1 diabetes patients with positive antibodies might suggest a possible common environmental trigger for these conditions.
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MESH Headings
- Adolescent
- Adult
- Aged
- Antibodies, Bacterial/blood
- Antibodies, Bacterial/immunology
- Case-Control Studies
- Cation Transport Proteins/chemistry
- Cation Transport Proteins/immunology
- Child
- Child, Preschool
- Cross Reactions/immunology
- Diabetes Mellitus, Type 1/blood
- Diabetes Mellitus, Type 1/immunology
- Diabetes Mellitus, Type 1/pathology
- Diabetes Mellitus, Type 2/blood
- Diabetes Mellitus, Type 2/immunology
- Diabetes Mellitus, Type 2/pathology
- Diabetic Retinopathy/blood
- Diabetic Retinopathy/immunology
- Diabetic Retinopathy/pathology
- Epitopes/immunology
- Female
- Humans
- Infant
- Infant, Newborn
- Insulin-Secreting Cells/immunology
- Insulin-Secreting Cells/pathology
- Male
- Middle Aged
- Mycobacterium avium subsp. paratuberculosis/immunology
- Peptides/immunology
- Seroepidemiologic Studies
- Young Adult
- Zinc Transporter 8
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Affiliation(s)
- Antonio Pinna
- Department of Surgical, Microsurgical and Medical Sciences, Section of Ophthalmology, University of Sassari, Sassari, Italy
- Azienda Ospedaliero-Universitaria di Sassari, Sassari, Italy
- * E-mail:
| | - Speranza Masala
- Department of Biomedical Sciences, Section of Experimental and Clinical Microbiology, University of Sassari, Sassari, Italy
| | - Francesco Blasetti
- Department of Surgical, Microsurgical and Medical Sciences, Section of Ophthalmology, University of Sassari, Sassari, Italy
| | - Irene Maiore
- Department of Surgical, Microsurgical and Medical Sciences, Section of Ophthalmology, University of Sassari, Sassari, Italy
| | - Davide Cossu
- Department of Biomedical Sciences, Section of Experimental and Clinical Microbiology, University of Sassari, Sassari, Italy
| | - Daniela Paccagnini
- Department of Biomedical Sciences, Section of Experimental and Clinical Microbiology, University of Sassari, Sassari, Italy
| | - Giuseppe Mameli
- Department of Biomedical Sciences, Section of Experimental and Clinical Microbiology, University of Sassari, Sassari, Italy
| | - Leonardo A. Sechi
- Department of Biomedical Sciences, Section of Experimental and Clinical Microbiology, University of Sassari, Sassari, Italy
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Gerber PA, Bellomo EA, Hodson DJ, Meur G, Solomou A, Mitchell RK, Hollinshead M, Chimienti F, Bosco D, Hughes SJ, Johnson PRV, Rutter GA. Hypoxia lowers SLC30A8/ZnT8 expression and free cytosolic Zn2+ in pancreatic beta cells. Diabetologia 2014; 57:1635-44. [PMID: 24865615 PMCID: PMC4079946 DOI: 10.1007/s00125-014-3266-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Accepted: 04/23/2014] [Indexed: 12/16/2022]
Abstract
AIMS/HYPOTHESIS Hypoxic damage complicates islet isolation for transplantation and may contribute to beta cell failure in type 2 diabetes. Polymorphisms in the SLC30A8 gene, encoding the secretory granule zinc transporter 8 (ZnT8), influence type 2 diabetes risk, conceivably by modulating cytosolic Zn(2+) levels. We have therefore explored the role of ZnT8 and cytosolic Zn(2+) in the response to hypoxia of pancreatic islet cells. METHODS Human, mouse or rat islets were isolated and exposed to varying O2 tensions. Cytosolic free zinc was measured using the adenovirally expressed recombinant targeted zinc probe eCALWY4. Gene expression was measured using quantitative (q)RT-PCR, western (immuno-) blotting or immunocytochemistry. Beta cells were identified by insulin immunoreactivity. RESULTS Deprivation of O2 (1% vs 5% or 21%) for 24 h lowered free cytosolic Zn(2+) concentrations by ~40% (p < 0.05) and ~30% (p < 0.05) in mouse and human islet cells, respectively. Hypoxia similarly decreased SLC30A8 mRNA expression in islets, and immunoreactivity in beta cells. Implicating lowered ZnT8 levels in the hypoxia-induced fall in cytosolic Zn(2+), genetic ablation of Slc30a8 from mouse islets lowered cytosolic Zn(2+) by ~40% (p < 0.05) and decreased the induction of metallothionein (Mt1, Mt2) genes. Cell survival in the face of hypoxia was enhanced in small islets of older (>12 weeks) Slc30a8 null mice vs controls, but not younger animals. CONCLUSIONS/INTERPRETATION The response of pancreatic beta cells to hypoxia is characterised by decreased SLC30A8 expression and lowered cytosolic Zn(2+) concentrations. The dependence on ZnT8 of hypoxia-induced changes in cell survival may contribute to the actions of SLC30A8 variants on diabetes risk in humans.
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Affiliation(s)
- Philipp A. Gerber
- Section of Cell Biology, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, London, W12 ONN UK
- Division of Endocrinology, Diabetes and Clinical Nutrition, University Hospital Zurich, Zurich, Switzerland
| | - Elisa A. Bellomo
- Section of Cell Biology, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, London, W12 ONN UK
| | - David J. Hodson
- Section of Cell Biology, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, London, W12 ONN UK
| | - Gargi Meur
- Section of Cell Biology, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, London, W12 ONN UK
| | - Antonia Solomou
- Section of Cell Biology, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, London, W12 ONN UK
| | - Ryan K. Mitchell
- Section of Cell Biology, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, London, W12 ONN UK
| | - Michael Hollinshead
- Section of Microscopy, Department of Medicine, Imperial College London, London, UK
| | | | - Domenico Bosco
- Cell Isolation and Transplantation Centre, Department of Surgery, Geneva University Hospital, Geneva, Switzerland
| | - Stephen J. Hughes
- Nuffield Department of Surgical Sciences, University of Oxford, Oxford, UK
- DRWF Human Islet Isolation Facility, Oxford Centre for Diabetes, Endocrinology and Metabolism, Oxford, UK
- Oxford NIHR Biomedical Research Centre, Oxford, UK
| | - Paul R. V. Johnson
- Nuffield Department of Surgical Sciences, University of Oxford, Oxford, UK
- DRWF Human Islet Isolation Facility, Oxford Centre for Diabetes, Endocrinology and Metabolism, Oxford, UK
- Oxford NIHR Biomedical Research Centre, Oxford, UK
| | - Guy A. Rutter
- Section of Cell Biology, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, London, W12 ONN UK
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Davidson HW, Wenzlau JM, O'Brien RM. Zinc transporter 8 (ZnT8) and β cell function. Trends Endocrinol Metab 2014; 25:415-24. [PMID: 24751356 PMCID: PMC4112161 DOI: 10.1016/j.tem.2014.03.008] [Citation(s) in RCA: 101] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Revised: 03/17/2014] [Accepted: 03/19/2014] [Indexed: 02/07/2023]
Abstract
Human pancreatic β cells have exceptionally high zinc content. In β cells the highest zinc concentration is in insulin secretory granules, from which it is cosecreted with the hormone. Uptake of zinc into secretory granules is mainly mediated by zinc transporter 8 (ZnT8), the product of the SLC30A8 [solute carrier family 30 (zinc transporter), member 8] gene. The minor alleles of several single-nucleotide polymorphisms (SNPs) in SLC30A8 are associated with decreased risk of type 2 diabetes (T2D), but the precise mechanisms underlying the protective effects remain uncertain. In this article we review current knowledge of the role of ZnT8 in maintaining zinc homeostasis in β cells, its role in glucose metabolism based on knockout mouse studies, and current theories regarding the link between ZnT8 function and T2D.
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Affiliation(s)
- Howard W Davidson
- Barbara Davis Center for Diabetes, University of Colorado Denver Anschutz Medical Campus, Aurora, CO 80045, USA; Integrated Department of Immunology, University of Colorado Denver Anschutz Medical Campus, Aurora, CO 80045, USA.
| | - Janet M Wenzlau
- Barbara Davis Center for Diabetes, University of Colorado Denver Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Richard M O'Brien
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
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Jaberi-Douraki M, Pietropaolo M, Khadra A. Predictive models of type 1 diabetes progression: understanding T-cell cycles and their implications on autoantibody release. PLoS One 2014; 9:e93326. [PMID: 24705439 PMCID: PMC3976292 DOI: 10.1371/journal.pone.0093326] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2014] [Accepted: 02/28/2014] [Indexed: 02/06/2023] Open
Abstract
Defining the role of T-cell avidity and killing efficacy in forming immunological response(s), leading to relapse-remission and autoantibody release in autoimmune type 1 diabetes (T1D), remains incompletely understood. Using competition-based population models of T- and B-cells, we provide a predictive tool to determine how these two parametric quantities, namely, avidity and killing efficacy, affect disease outcomes. We show that, in the presence of T-cell competition, successive waves along with cyclic fluctuations in the number of T-cells are exhibited by the model, with the former induced by transient bistability and the latter by transient periodic orbits. We hypothesize that these two immunological processes are responsible for making T1D a relapsing-remitting disease within prolonged but limited durations. The period and the number of peaks of these two processes differ, making them potential candidates to determine how plausible waves and cyclic fluctuations are in producing such effects. By assuming that T-cell and B-cell avidities are correlated, we demonstrate that autoantibodies associated with the higher avidity T-cell clones are first to be detected, and they reach their detectability level faster than those associated with the low avidity clones, independent of what T-cell killing efficacies are. Such outcomes are consistent with experimental observations in humans and they provide a rationale for observing rapid and slow progressors of T1D in high risk subjects. Our analysis of the models also reveals that it is possible to improve disease outcomes by unexpectedly increasing the avidity of certain subclones of T-cells. The decline in the number of β-cells in these cases still occurs, but it terminates early, leaving sufficient number of functioning β-cells in operation and the affected individual asymptomatic. These results indicate that the models presented here are of clinical relevance because of their potential use in developing predictive algorithms of rapid and slow progression to clinical T1D.
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Affiliation(s)
| | - Massimo Pietropaolo
- Laboratory of Immunogenetics, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Anmar Khadra
- Department of Physiology, McGill University, Montreal, QC, Canada
- * E-mail:
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Sprouse C, Gordish-Dressman H, Orkunoglu-Suer EF, Lipof JS, Moeckel-Cole S, Patel RR, Adham K, Larkin JS, Hubal MJ, Kearns AK, Clarkson PM, Thompson PD, Angelopoulos TJ, Gordon PM, Moyna NM, Pescatello LS, Visich PS, Zoeller RF, Hoffman EP, Tosi LL, Devaney JM. SLC30A8 nonsynonymous variant is associated with recovery following exercise and skeletal muscle size and strength. Diabetes 2014; 63:363-8. [PMID: 24101675 DOI: 10.2337/db13-1150] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Genome-wide association studies have identified thousands of variants that are associated with numerous phenotypes. One such variant, rs13266634, a nonsynonymous single nucleotide polymorphism in the solute carrier family 30 (zinc transporter) member eight gene, is associated with a 53% increase in the risk of developing type 2 diabetes (T2D). We hypothesized that individuals with the protective allele against T2D would show a positive response to short-term and long-term resistance exercise. Two cohorts of young adults-the Eccentric Muscle Damage (EMD; n = 156) cohort and the Functional Single Nucleotide Polymorphisms Associated with Muscle Size and Strength Study (FAMuSS; n = 874)-were tested for association of the rs13266634 variant with measures of skeletal muscle response to resistance exercise. Our results were sexually dimorphic in both cohorts. Men in the EMD study with two copies of the protective allele showed less post-exercise bout strength loss, less soreness, and lower creatine kinase values. In addition, men in the FAMuSS, homozygous for the protective allele, showed higher pre-exercise strength and larger arm skeletal muscle volume, but did not show a significant difference in skeletal muscle hypertrophy or strength with resistance training.
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Affiliation(s)
- Courtney Sprouse
- Department of Integrative Systems Biology, Research Center for Genetic Medicine, Children's National Medical Center, Washington, DC
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20
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Ugarte M, Osborne NN. Recent advances in the understanding of the role of zinc in ocular tissues. Metallomics 2014; 6:189-200. [DOI: 10.1039/c3mt00291h] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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Wang Y, Su R, Lv G, Cao Y, Fan Z, Wang Y, Zhang L, Yu D, Mei X. Supplement zinc as an effective treatment for spinal cord ischemia/reperfusion injury in rats. Brain Res 2013; 1545:45-53. [PMID: 24361987 DOI: 10.1016/j.brainres.2013.12.015] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Revised: 10/20/2013] [Accepted: 12/13/2013] [Indexed: 11/20/2022]
Abstract
OBJECTIVE Brain-derived neurotrophic factor (BDNF) plays a key role in the pathophysiology process and therapy of spinal cord injury (SCI). Accordingly, zinc regulates the expression of BDNF and its receptor in the central nervous system, the mechanism of which is still unknown. The present study investigates whether supplement zinc could reduce neurological damage in a rat model, with spinal cord ischemia-reperfusion (I/R) injury and how the effect of zinc transporter 1(ZnT-1) was involved. METHODS 100 Sprague-Dawley male rats were randomly and evenly divided into four groups. They were subjected to spinal cord ischemia by clamping the abdominal aorta for 45 min. Rats in the zinc-deficient dietary model group (ZD), zinc-adequate dietary model group (ZA), and zinc-high dietary model group (ZH) were given free access to purified diet, containing 5, 30, or 180 mg Zn/kg. Sham operation rats were subjected to laparotomy without clamping of the aorta and were fed by ZA diet (30 mg Zn/kg). Neurological function was scored by Tarlov's score. The spinal cord segments (L5) were harvested for histological examination, auto-metallographic (AMG) analysis, myeloperoxidase (MPO) activity analysis, expression of ZnT-1 and BDNF. RESULTS The rats in the ZH group have shown the higher neurological scores, slighter histological changes and the attenuated MPO activity, compared with those in the ZD and ZA groups at the four observation time points (p<0.05). The AMG staining density in the ZH group was significantly higher than that of ZD group in 14 days later after the operation. Compared with other groups, ZH group's expression of Zn-T1 and BDNF were significantly increased, and was positively correlated with the same time points after surgery (Spearman rho=0.403, p=0.0152.) CONCLUSION These findings suggest that zinc supplement can significantly reduce the spinal cord I/R injury in rats. The mechanism may be related with restraining the MPO activity and increasing of ZnT-1, which promoted the synthesis and release of BDNF.
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Affiliation(s)
- Yansong Wang
- Department of Orthopedics, First Affiliated Hospital of Liaoning Medical University, Jinzhou City, PR China
| | - Ribao Su
- Department of Orthopedics, Zhoupu Hospital of Pudong New Area, Shanghai City, PR China
| | - Gang Lv
- Department of Orthopedics, First Affiliated Hospital of Liaoning Medical University, Jinzhou City, PR China
| | - Yang Cao
- Department of Orthopedics, First Affiliated Hospital of Liaoning Medical University, Jinzhou City, PR China
| | - Zhongkai Fan
- Department of Orthopedics, First Affiliated Hospital of Liaoning Medical University, Jinzhou City, PR China
| | - Yanfeng Wang
- Department of Orthopedics, First Affiliated Hospital of China Medical University, Shenyang City, PR China
| | - Li Zhang
- Department of Histology and Embryology, Liaoning Medical University, Jinzhou City, PR China
| | - Deshui Yu
- Department of Orthopedics, First Affiliated Hospital of Liaoning Medical University, Jinzhou City, PR China
| | - Xifan Mei
- Department of Orthopedics, First Affiliated Hospital of Liaoning Medical University, Jinzhou City, PR China.
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Størling J, Overgaard AJ, Brorsson CA, Piva F, Bang-Berthelsen CH, Haase C, Nerup J, Pociot F. Do post-translational beta cell protein modifications trigger type 1 diabetes? Diabetologia 2013; 56:2347-54. [PMID: 24048671 DOI: 10.1007/s00125-013-3045-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Accepted: 06/04/2013] [Indexed: 12/20/2022]
Abstract
Type 1 diabetes is considered an autoimmune disease characterised by specific T cell-mediated destruction of the insulin-producing beta cells. Yet, except for insulin, no beta cell-specific antigens have been discovered. This may imply that the autoantigens in type 1 diabetes exist in modified forms capable of specifically triggering beta cell destruction. In other immune-mediated diseases, autoantigens targeted by the immune system have undergone post-translational modification (PTM), thereby creating tissue-specific neo-epitopes. In a similar manner, PTM of beta cell proteins might create beta cell-specific neo-epitopes. We suggest that the current paradigm of type 1 diabetes as a classical autoimmune disease should be reconsidered since the immune response may not be directed against native beta cell proteins. A modified model for the pathogenetic events taking place in islets leading to the T cell attack against beta cells is presented. In this model, PTM plays a prominent role in triggering beta cell destruction. We discuss literature of relevance and perform genetic and human islet gene expression analyses. Both direct and circumstantial support for the involvement of PTM in type 1 diabetes exists in the published literature. Furthermore, we report that cytokines change the expression levels of several genes encoding proteins involved in PTM processes in human islets, and that there are type 1 diabetes-associated polymorphisms in a number of these. In conclusion, data from the literature and presented experimental data support the notion that PTM of beta cell proteins may be involved in triggering beta cell destruction in type 1 diabetes. If the beta cell antigens recognised by the immune system foremost come from modified proteins rather than native ones, the concept of type 1 diabetes as a classical autoimmune disease is open for debate.
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Affiliation(s)
- Joachim Størling
- Copenhagen Diabetes Research Center (DIRECT), Herlev University Hospital, Herlev Ringvej 75, 2730, Herlev, Denmark,
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Tang XJ, Xing F. Calcium-permeable AMPA receptors in neonatal hypoxic-ischemic encephalopathy (Review). Biomed Rep 2013; 1:828-832. [PMID: 24649036 DOI: 10.3892/br.2013.154] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Accepted: 07/18/2013] [Indexed: 11/06/2022] Open
Abstract
Hypoxic-ischemic encephalopathy (HIE) is an important cause of brain injury in the newborn and may result in long-term devastating consequences. Excessive stimulation of glutamate receptors (GluRs) is a pivotal mechanism underlying ischemia-induced selective and delayed neuronal death. Although initial studies focused on N-methyl-D-aspartic acid (NMDA) receptors as critical mediators in HIE, subsequent studies supported a more central role for α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors (AMPARs), particularly Ca2+-permeable AMPARs, in brain damage associated with hypoxia-ischemia. This study reviewed the important role of Ca2+-permeable AMPARs in HIE and the future potential neuroprotective strategies associated with Ca2+-permeable AMPARs.
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Affiliation(s)
- Xiao-Juan Tang
- Department of Neonatology, Children's Hospital Affiliated to Soochow University, Suzhou, Jiangsu 215003, P.R. China
| | - Feng Xing
- Department of Neonatology, Children's Hospital Affiliated to Soochow University, Suzhou, Jiangsu 215003, P.R. China
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Shukolyukov SA. Rhodopsin, Zn2+, and retinitis pigmentosa: a Short tale requiring continuation. BIOCHEMISTRY (MOSCOW) 2013; 78:660-6. [DOI: 10.1134/s0006297913060114] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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DeNiro M, Al-Mohanna FH, Alsmadi O, Al-Mohanna FA. The nexus between VEGF and NFκB orchestrates a hypoxia-independent neovasculogenesis. PLoS One 2013; 8:e59021. [PMID: 23533599 PMCID: PMC3606454 DOI: 10.1371/journal.pone.0059021] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Accepted: 02/09/2013] [Indexed: 11/20/2022] Open
Abstract
Nuclear Factor-Kappa B [NFκB] activation triggers the elevation of various pro-angiogenic factors that contribute to the development and progression of diabetic vasculopathies. It has been demonstrated that vascular endothelial growth factor [VEGF] activates NFκB signaling pathway. Under the ischemic microenvironments, hypoxia-inducible factor-1 [HIF-1] upregulates the expression of several proangiogenic mediators, which play crucial roles in ocular pathologies. Whereas YC-1, a soluble guanylyl cyclase [sGC] agonist, inhibits HIF-1 and NFκB signaling pathways in various cell and animal models. Throughout this investigation, we examined the molecular link between VEGF and NFκB under a hypoxia-independent microenvironment in human retinal microvascular endothelial cells [hRMVECs]. Our data indicate that VEGF promoted retinal neovasculogenesis via NFκB activation, enhancement of its DNA-binding activity, and upregulating NFκB/p65, SDF-1, CXCR4, FAK, αVβ3, α5β1, EPO, ET-1, and MMP-9 expression. Conversely, YC-1 impaired the activation of NFκB and its downstream signaling pathways, via attenuating IκB kinase phosphorylation, degradation and activation, and thus suppressing p65 phosphorylation, nuclear translocation, and inhibiting NFκB-DNA binding activity. We report for the first time that the nexus between VEGF and NFκB is implicated in coordinating a scheme that upregulates several pro-angiogenic molecules, which promotes retinal neovasculogenesis. Our data may suggest the potential use of YC-1 to attenuate the deleterious effects that are associated with hypoxia/ischemia-independent retinal vasculopathies.
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Affiliation(s)
- Michael DeNiro
- Research Department, King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia.
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Miao X, Sun W, Miao L, Fu Y, Wang Y, Su G, Liu Q. Zinc and diabetic retinopathy. J Diabetes Res 2013; 2013:425854. [PMID: 23671870 PMCID: PMC3647550 DOI: 10.1155/2013/425854] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Accepted: 02/08/2013] [Indexed: 02/02/2023] Open
Abstract
Zinc (Zn) is an important nutrient that is involved in various physiological metabolisms. Zn dyshomeostasis is often associated with various pathogeneses of chronic diseases, such as metabolic syndrome, diabetes, and related complications. Zn is present in ocular tissue in high concentrations, particularly in the retina and choroid. Zn deficiencies have been shown to affect ocular development, cataracts, age-related macular degeneration, and even diabetic retinopathy. However, the mechanism by which Zn deficiency increases the prevalence of diabetic retinopathy remains unclear. In addition, due to the negative effect of Zn deficiency on the eye, Zn supplementation should prevent diabetic retinopathy; however, limited available data do not always support this notion. Therefore, the goal of this paper was to summarize these pieces of available information regarding Zn prevention of diabetic retinopathy. Current theories and possible mechanisms underlying the role of Zn in the eye-related diseases are discussed. The possible factors that affect the preventive effect of Zn supplementation on diabetic retinopathy were also discussed.
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Affiliation(s)
- Xiao Miao
- The Second Hospital of Jilin University, Changchun 130021, China
- Department of Ophthalmology, The Second Hospital of Jilin University, 218 Ziqiang Street, Changchun 130041, China
| | - Weixia Sun
- The First Hospital of Jilin University, Changchun 130021, China
| | - Lining Miao
- The Second Hospital of Jilin University, Changchun 130021, China
| | - Yaowen Fu
- The First Hospital of Jilin University, Changchun 130021, China
| | - Yonggang Wang
- The First Hospital of Jilin University, Changchun 130021, China
| | - Guanfang Su
- The Second Hospital of Jilin University, Changchun 130021, China
- Department of Ophthalmology, The Second Hospital of Jilin University, 218 Ziqiang Street, Changchun 130041, China
- *Guanfang Su: and
| | - Quan Liu
- The First Hospital of Jilin University, Changchun 130021, China
- Department of Cardiovascular Disease, The First Hospital of Jilin University, Changchun, Jilin 130021, China
- *Quan Liu:
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