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Malik SS, Padmanabhan D, Hull-Meichle RL. Pancreas and islet morphology in cystic fibrosis: clues to the etiology of cystic fibrosis-related diabetes. Front Endocrinol (Lausanne) 2023; 14:1269139. [PMID: 38075070 PMCID: PMC10704027 DOI: 10.3389/fendo.2023.1269139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Accepted: 10/03/2023] [Indexed: 12/18/2023] Open
Abstract
Cystic fibrosis (CF) is a multi-organ disease caused by loss-of-function mutations in CFTR (which encodes the CF transmembrane conductance regulator ion channel). Cystic fibrosis related diabetes (CFRD) occurs in 40-50% of adults with CF and is associated with significantly increased morbidity and mortality. CFRD arises from insufficient insulin release from β cells in the pancreatic islet, but the mechanisms underlying the loss of β cell function remain understudied. Widespread pathological changes in the CF pancreas provide clues to these mechanisms. The exocrine pancreas is the epicenter of pancreas pathology in CF, with ductal pathology being the initiating event. Loss of CFTR function results in ductal plugging and subsequent obliteration. This in turn leads to destruction of acinar cells, fibrosis and fatty replacement. Despite this adverse environment, islets remain relatively well preserved. However, islet composition and arrangement are abnormal, including a modest decrease in β cells and an increase in α, δ and γ cell abundance. The small amount of available data suggest that substantial loss of pancreatic/islet microvasculature, autonomic nerve fibers and intra-islet macrophages occur. Conversely, T-cell infiltration is increased and, in CFRD, islet amyloid deposition is a frequent occurrence. Together, these pathological changes clearly demonstrate that CF is a disease of the pancreas/islet microenvironment. Any or all of these changes are likely to have a dramatic effect on the β cell, which relies on positive signals from all of these neighboring cell types for its normal function and survival. A thorough characterization of the CF pancreas microenvironment is needed to develop better therapies to treat, and ultimately prevent CFRD.
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Affiliation(s)
- Sarah S. Malik
- Department of Pharmacology, University of Washington, Seattle, WA, United States
- Research Service, Veterans Affairs Puget Sound Health Care System, Seattle, WA, United States
| | - Diksha Padmanabhan
- Research Service, Veterans Affairs Puget Sound Health Care System, Seattle, WA, United States
- Seattle Institute for Biomedical and Clinical Research, Seattle, WA, United States
| | - Rebecca L. Hull-Meichle
- Department of Pharmacology, University of Washington, Seattle, WA, United States
- Research Service, Veterans Affairs Puget Sound Health Care System, Seattle, WA, United States
- Seattle Institute for Biomedical and Clinical Research, Seattle, WA, United States
- Division of Metabolism, Endocrinology, and Nutrition, Department of Medicine, University of Washington, Seattle, WA, United States
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2
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Upregulation of Reg IV and Hgf mRNAs by Intermittent Hypoxia via Downregulation of microRNA-499 in Cardiomyocytes. Int J Mol Sci 2022; 23:ijms232012414. [PMID: 36293268 PMCID: PMC9603944 DOI: 10.3390/ijms232012414] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 10/06/2022] [Accepted: 10/07/2022] [Indexed: 11/17/2022] Open
Abstract
Sleep apnea syndrome (SAS) is characterized by recurrent episodes of oxygen desaturation and reoxygenation (intermittent hypoxia [IH]), and is a risk factor for cardiovascular disease (CVD) and insulin resistance/Type 2 diabetes. However, the mechanisms linking IH stress and CVD remain elusive. We exposed rat H9c2 and mouse P19.CL6 cardiomyocytes to experimental IH or normoxia for 24 h to analyze the mRNA expression of several cardiomyokines. We found that the mRNA levels of regenerating gene IV (Reg IV) and hepatocyte growth factor (Hgf) in H9c2 and P19.CL6 cardiomyocytes were significantly increased by IH, whereas the promoter activities of the genes were not increased. A target mRNA search of microRNA (miR)s revealed that rat and mouse mRNAs have a potential target sequence for miR-499. The miR-499 level of IH-treated cells was significantly decreased compared to normoxia-treated cells. MiR-499 mimic and non-specific control RNA (miR-499 mimic NC) were introduced into P19.CL6 cells, and the IH-induced upregulation of the genes was abolished by introduction of the miR-499 mimic, but not by the miR-499 mimic NC. These results indicate that IH stress downregulates the miR-499 in cardiomyocytes, resulting in increased levels of Reg IV and Hgf mRNAs, leading to the protection of cardiomyocytes in SAS patients.
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3
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Kahraman S, Dirice E, Basile G, Diegisser D, Alam J, Johansson BB, Gupta MK, Hu J, Huang L, Soh CL, Huangfu D, Muthuswamy SK, Raeder H, Molven A, Kulkarni RN. Abnormal exocrine-endocrine cell cross-talk promotes β-cell dysfunction and loss in MODY8. Nat Metab 2022; 4:76-89. [PMID: 35058633 DOI: 10.1038/s42255-021-00516-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 12/08/2021] [Indexed: 12/12/2022]
Abstract
MODY8 (maturity-onset diabetes of the young, type 8) is a dominantly inherited monogenic form of diabetes associated with mutations in the carboxyl ester lipase (CEL) gene expressed by pancreatic acinar cells. MODY8 patients develop childhood-onset exocrine pancreas dysfunction followed by diabetes during adulthood. However, it is unclear how CEL mutations cause diabetes. In the present study, we report the transfer of CEL proteins from acinar cells to β-cells as a form of cross-talk between exocrine and endocrine cells. Human β-cells show a relatively higher propensity for internalizing the mutant versus the wild-type CEL protein. After internalization, the mutant protein forms stable intracellular aggregates leading to β-cell secretory dysfunction. Analysis of pancreas sections from a MODY8 patient reveals the presence of CEL protein in the few extant β-cells. The present study provides compelling evidence for the mechanism by which a mutant gene expressed specifically in acinar cells promotes dysfunction and loss of β-cells to cause diabetes.
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Affiliation(s)
- Sevim Kahraman
- Islet Cell and Regenerative Biology, Joslin Diabetes Center, Boston, MA, USA
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
- Harvard Stem Cell Institute, Harvard Medical School, Boston, MA, USA
| | - Ercument Dirice
- Islet Cell and Regenerative Biology, Joslin Diabetes Center, Boston, MA, USA
- Department of Pharmacology, New York Medical College of Medicine, Valhalla, NY, USA
| | - Giorgio Basile
- Islet Cell and Regenerative Biology, Joslin Diabetes Center, Boston, MA, USA
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
- Harvard Stem Cell Institute, Harvard Medical School, Boston, MA, USA
| | - Danielle Diegisser
- Islet Cell and Regenerative Biology, Joslin Diabetes Center, Boston, MA, USA
- Department of Pharmacology, New York Medical College of Medicine, Valhalla, NY, USA
| | - Jahedul Alam
- Gade Laboratory for Pathology, Department of Clinical Medicine, University of Bergen, Bergen, Norway
| | - Bente B Johansson
- Center for Diabetes Research, Department of Clinical Science, University of Bergen, Bergen, Norway
| | - Manoj K Gupta
- Islet Cell and Regenerative Biology, Joslin Diabetes Center, Boston, MA, USA
| | - Jiang Hu
- Islet Cell and Regenerative Biology, Joslin Diabetes Center, Boston, MA, USA
| | - Ling Huang
- Cancer Research Institute, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Chew-Li Soh
- Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Danwei Huangfu
- Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Senthil K Muthuswamy
- Cancer Research Institute, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Helge Raeder
- Center for Diabetes Research, Department of Clinical Science, University of Bergen, Bergen, Norway
- Department of Pediatrics, Haukeland University Hospital, Bergen, Norway
| | - Anders Molven
- Gade Laboratory for Pathology, Department of Clinical Medicine, University of Bergen, Bergen, Norway
- Center for Diabetes Research, Department of Clinical Science, University of Bergen, Bergen, Norway
- Department of Pathology, Haukeland University Hospital, Bergen, Norway
| | - Rohit N Kulkarni
- Islet Cell and Regenerative Biology, Joslin Diabetes Center, Boston, MA, USA.
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
- Harvard Stem Cell Institute, Harvard Medical School, Boston, MA, USA.
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OKAMOTO H, TAKASAWA S. Okamoto model for necrosis and its expansions, CD38-cyclic ADP-ribose signal system for intracellular Ca 2+ mobilization and Reg (Regenerating gene protein)-Reg receptor system for cell regeneration. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2021; 97:423-461. [PMID: 34629354 PMCID: PMC8553518 DOI: 10.2183/pjab.97.022] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 06/22/2021] [Indexed: 05/03/2023]
Abstract
In pancreatic islet cell culture models and animal models, we studied the molecular mechanisms involved in the development of insulin-dependent diabetes. The diabetogenic agents, alloxan and streptozotocin, caused DNA strand breaks, which in turn activated poly(ADP-ribose) polymerase/synthetase (PARP) to deplete NAD+, thereby inhibiting islet β-cell functions such as proinsulin synthesis and ultimately leading to β-cell necrosis. Radical scavengers protected against the formation of DNA strand breaks and inhibition of proinsulin synthesis. Inhibitors of PARP prevented the NAD+ depletion, inhibition of proinsulin synthesis and β-cell death. These findings led to the proposed unifying concept for β-cell damage and its prevention (the Okamoto model). The model met one proof with PARP knockout animals and was further extended by the discovery of cyclic ADP-ribose as the second messenger for Ca2+ mobilization in glucose-induced insulin secretion and by the identification of Reg (Regenerating gene) for β-cell regeneration. Physiological and pathological events found in pancreatic β-cells have been observed in other cells and tissues.
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Affiliation(s)
- Hiroshi OKAMOTO
- Department of Biochemistry, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
- Department of Biochemistry and Molecular Vascular Biology, Kanazawa University Graduate School of Medical Sciences, Kanazawa, Ishikawa, Japan
| | - Shin TAKASAWA
- Department of Biochemistry, Nara Medical University, Kashihara, Nara, Japan
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Kobayashi T, Tanaka S, Aida K. Unique pathological changes in the pancreas of fulminant type 1 diabetes. Diabetol Int 2020; 11:323-328. [PMID: 33088638 DOI: 10.1007/s13340-020-00462-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 08/18/2020] [Indexed: 12/16/2022]
Abstract
Distinct features of the pancreas of fulminant type 1 diabetes (FT1DM) include (1) enterovirus infection of the islets and exocrine acinar tissue. (2) Activated innate immune responses: MDA5 and RIG-I expression and TLR4 and TLR9 expression in the islets of FT1DM. (3) Combined activation of the STAT/JNK and NFkB pathways, resulting in Type I interferon (IFN) and proinflammatory cytokine (i.e., IFNγ) expression in islet beta cells and MHC class I hyper-expression. (4) Activation of dendritic cells followed by effector cell infiltration of CD8+ T cells and CD68+ macrophages, resulting in apoptosis and neurosis of islet cells and exocrine acinar cells. (5) Many chemo-attractants (i.e., CXCL10) and chemotactic activators (i.e., l-plastin) were induced by a viral infection. (6) Mutual stimulating effect of cytokines expressed in beta cells in autocrine and paracrine mechanisms may enhance beta-cell destruction through the STA1-caspase pathway. (7) Proteomics analysis using laser capture microdissection followed by mass spectrometry found 38 molecules in inflamed islets of FT1DM, which were not highlighted before. Our pathologically verified model of beta-cell destruction in FT1DM will contribute to anti-virus therapy of type 1 diabetes in the near future.
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Affiliation(s)
- Tetsuro Kobayashi
- Division of Immunology and Molecular Medicine, Okinaka Memorial Institute for Medical Research, 2-2-2 Toranomon, Minato-ku, Tokyo, 105-8470 Japan.,Department of Endocrinology and Metabolism, Toranomon Hospital, Tokyo, Japan
| | - Shoichiro Tanaka
- Ai Home Clinic Toshima, 4th Floor, INS Building, 2-32-2 Minamiotsuka, Toshima-ku, Tokyo, 170-0005 Japan
| | - Kaoru Aida
- Department of Diabetes Medicine, Kanoiwa Hospital, Kamijinnai River 1309, Yamanashi, Yamanashi Japan
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6
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Genetic Susceptibility of the Host in Virus-Induced Diabetes. Microorganisms 2020; 8:microorganisms8081133. [PMID: 32727064 PMCID: PMC7464158 DOI: 10.3390/microorganisms8081133] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 07/07/2020] [Accepted: 07/24/2020] [Indexed: 12/13/2022] Open
Abstract
Enteroviruses, especially Coxsackie B viruses, are among the candidate environmental factors causative of type 1 diabetes. Host genetic factors have an impact on the development of virus-induced diabetes (VID). Host background, in terms of whether the host is prone to autoimmunity, should also be considered when analyzing the role of target genes in VID. In this review, we describe the genetic susceptibility of the host based on studies in humans and VID animal models. Understanding the host genetic factors should contribute not only to revealing the mechanisms of VID development, but also in taking measures to prevent VID.
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El-Kersh AOFO, El-Akabawy G, Al-Serwi RH. Transplantation of human dental pulp stem cells in streptozotocin-induced diabetic rats. Anat Sci Int 2020; 95:523-539. [PMID: 32476103 DOI: 10.1007/s12565-020-00550-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Accepted: 05/20/2020] [Indexed: 12/11/2022]
Abstract
Type 1 diabetes mellitus (T1DM) is a chronic metabolic disease caused by the destruction of pancreatic β-cells. Human dental pulp stem cells represent a promising source for cell-based therapies, owing to their easy, minimally invasive surgical access, and high proliferative capacity. It was reported that human dental pulp stem cells can differentiate into a pancreatic cell lineage in vitro; however, few studies have investigated their effects on diabetes. Our study aimed to investigate the therapeutic potential of intravenous and intrapancreatic transplantation of human dental pulp stem cells in a rat model of streptozotocin-induced type 1 diabetes. Forty Sprague Dawley male rats were randomly categorized into four groups: control, diabetic (STZ), intravenous treatment group (IV), and intrapancreatic treatment group (IP). Human dental pulp stem cells (1 × 106 cells) or vehicle were injected into the pancreas or tail vein 7 days after streptozotocin injection. Fasting blood glucose levels were monitored weekly. Glucose tolerance test, rat and human serum insulin and C-peptide, pancreas histology, and caspase-3, vascular endothelial growth factor, and Ki67 expression in pancreatic tissues were assessed 28 days post-transplantation. We found that both IV and IP transplantation of human dental pulp stem cells reduced blood glucose and increased levels of rat and human serum insulin and C-peptide. The cells engrafted and survived in the streptozotocin-injured pancreas. Islet-like clusters and scattered human dental pulp stem cells expressing insulin were observed in the pancreas of diabetic rats with some difference in the distribution pattern between the two injection routes. RT-PCR analyses revealed the expression of the human-specific pancreatic β-cell genes neurogenin 3 (NGN3), paired box 4 (PAX4), glucose transporter 2 (GLUT2), and insulin in the pancreatic tissues of both the IP and IV groups. In addition, the transplanted cells downregulated the expression of caspase-3 and upregulated the expression of vascular endothelial growth factor and Ki67, suggesting that the injected cells exerted pro-angiogenetic and antiapoptotic effects, and promoted endogenous β-cell replication. Our study is the first to show that human dental pulp stem cells can migrate and survive within streptozotocin-injured pancreas, and induce antidiabetic effects through the differentiation and replacement of lost β-cells and paracrine-mediated pancreatic regeneration. Thus, human dental pulp stem cells may have therapeutic potential to treat patients with long term T1DM.
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Affiliation(s)
| | - Gehan El-Akabawy
- Department of Basic Sciences, College of Medicine, Princess Nourah Bint Abdulrahman University, Riyadh, Saudi Arabia. .,Department of Anatomy and Embryology, Faculty of Medicine, Menoufia University, Menoufia, Egypt.
| | - Rasha H Al-Serwi
- Basic Dental Sciences, College of Dentistry, Princess Nourah Bint Abdulrahman University, Riyadh, Saudi Arabia.,Oral Biology Department, Faculty of Dentistry, Mansoura University, Mansoura, Egypt
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8
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Mine K, Nagafuchi S, Hatano S, Tanaka K, Mori H, Takahashi H, Anzai K, Yoshikai Y. Impaired upregulation of Stat2 gene restrictive to pancreatic β-cells is responsible for virus-induced diabetes in DBA/2 mice. Biochem Biophys Res Commun 2020; 521:853-860. [PMID: 31708097 DOI: 10.1016/j.bbrc.2019.10.193] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 10/29/2019] [Indexed: 12/16/2022]
Abstract
Viral infection is a putative causal factor for the development of type 1 diabetes, but the exact pathogenic mechanism of virus-induced diabetes (VID) remains unclear. Here, to identify the critical factors that regulate VID, we analyzed encephalomyocarditis D (EMC-D) VID-sensitive DBA/2 mice in comparison with resistant B6 mice. EMC-D virus-induced cell death occurred more frequently in DBA/2 β-cells than in B6 β-cells with 100U/ml IFN-β priming in vitro. We therefore purified β-cells using flow cytometry from mice two days after EMC-D virus infection and subjected them to microarray analysis. As a results, innate immune response pathway was found to be enriched in B6 β-cells. The signal transducer and activator of transcription 2 (Stat2) gene interacted with genes in the pathway. Stat2 gene expression levels were lower in DBA/2 mice than in B6 mice, restrictive to β-cells. Moreover, administration of IFN-β failed to upregulate Stat2 gene in DBA/2 β-cells than in those of B6 in vivo. The viral titer significantly increased only in the DBA/2 pancreas. Thus, these provided data suggest that impaired upregulation of Stat2 gene restrictive to β-cells at the early stage of infection is responsible for VID development in DBA/2 mice.
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Affiliation(s)
- Keiichiro Mine
- Division of Host Defense, Medical Institute of Bioregulation, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan; Division of Metabolism and Endocrinology, Department of Internal Medicine, Faculty of Medicine, Saga University, 5-1-1, Nabeshima, Saga, 849-8501, Japan.
| | - Seiho Nagafuchi
- Division of Metabolism and Endocrinology, Department of Internal Medicine, Faculty of Medicine, Saga University, 5-1-1, Nabeshima, Saga, 849-8501, Japan.
| | - Shinya Hatano
- Division of Host Defense, Medical Institute of Bioregulation, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Kenichi Tanaka
- Division of Metabolism and Endocrinology, Department of Internal Medicine, Faculty of Medicine, Saga University, 5-1-1, Nabeshima, Saga, 849-8501, Japan
| | - Hitoe Mori
- Division of Metabolism and Endocrinology, Department of Internal Medicine, Faculty of Medicine, Saga University, 5-1-1, Nabeshima, Saga, 849-8501, Japan
| | - Hirokazu Takahashi
- Division of Metabolism and Endocrinology, Department of Internal Medicine, Faculty of Medicine, Saga University, 5-1-1, Nabeshima, Saga, 849-8501, Japan
| | - Keizo Anzai
- Division of Metabolism and Endocrinology, Department of Internal Medicine, Faculty of Medicine, Saga University, 5-1-1, Nabeshima, Saga, 849-8501, Japan
| | - Yasunobu Yoshikai
- Division of Host Defense, Medical Institute of Bioregulation, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
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9
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Chen Z, Downing S, Tzanakakis ES. Four Decades After the Discovery of Regenerating Islet-Derived (Reg) Proteins: Current Understanding and Challenges. Front Cell Dev Biol 2019; 7:235. [PMID: 31696115 PMCID: PMC6817481 DOI: 10.3389/fcell.2019.00235] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Accepted: 09/30/2019] [Indexed: 12/15/2022] Open
Abstract
Regenerating islet-derived (Reg) proteins have emerged as multifunctional agents with pro-proliferative, anti-apoptotic, differentiation-inducing and bactericidal properties. Over the last 40 years since first discovered, Reg proteins have been implicated in a gamut of maladies including diabetes, various types of cancer of the digestive tract, and Alzheimer disease. Surprisingly though, a consensus is still absent on the regulation of their expression, and molecular underpinning of their function. Here, we provide a critical appraisal of recent findings in the field of Reg protein biology. Specifically, the structural characteristics are reviewed particularly in connection with established or purported functions of different members of the Reg family. Moreover, Reg expression patterns in different tissues both under normal and pathophysiological conditions are summarized. Putative receptors and cascades reported to relay Reg signaling inciting cellular responses are presented aiming at a better appreciation of the biological activities of the distinct Reg moieties. Challenges are also discussed that have hampered thus far the rapid progress in this field such as the use of non-standard nomenclature for Reg molecules among various research groups, the existence of multiple Reg members with significant degree of homology and possibly compensatory modes of action, and the need for common assays with robust readouts of Reg activity. Coordinated research is warranted going forward, given that several research groups have independently linked Reg proteins to diseased states and raised the possibility that these biomolecules can serve as therapeutic targets and biomarkers.
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Affiliation(s)
- Zijing Chen
- Department of Chemical and Biological Engineering, Tufts University, Medford, MA, United States
| | - Shawna Downing
- Clinical and Translational Science Institute, Tufts Medical Center, Boston, MA, United States
| | - Emmanuel S Tzanakakis
- Department of Chemical and Biological Engineering, Tufts University, Medford, MA, United States.,Clinical and Translational Science Institute, Tufts Medical Center, Boston, MA, United States
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Downing S, Zhang F, Chen Z, Tzanakakis ES. MicroRNA-7 directly targets Reg1 in pancreatic cells. Am J Physiol Cell Physiol 2019; 317:C366-C374. [PMID: 31166710 DOI: 10.1152/ajpcell.00013.2019] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Regenerating islet-derived (Reg) proteins, which were first discovered in the pancreas, are associated with increased proliferation, prevention of apoptosis, and enhanced differentiation in normal and disease states, but very little is known about the regulation of their expression. We hypothesized that Reg expression is influenced by microRNAs. Bioinformatic analysis predicted Reg1 to be a target of microRNA-7 (miR-7), which influences pancreatic β-cell function. To this end, we investigated the effects of miR-7 on Reg1 expression in pancreatic acinar and islet β-cells. High levels of Reg1 were noted by immunostaining and Western blotting in acinar cells in contrast to islet cells. A reciprocal expression pattern was observed for miR-7. Overexpression of miR-7 resulted in Reg1 mRNA suppression and reduction of secreted Reg1 protein. Conversely, miR-7 knockdown led to increases in Reg1. Targeting of Reg1 by miR-7 was confirmed via luciferase activity assays. In contrast, miR-7 did not directly repress the human ortholog of Reg1 REG1A as well as REG1B indicating species differences in the regulation of Reg expression. This is the first account of microRNA modulation of any Reg member warranting studies to fill gaps in our knowledge of Reg protein biology, particularly in disease contexts.
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Affiliation(s)
- Shawna Downing
- Department of Chemical and Biological Engineering, Tufts University, Medford, Massachusetts
| | - Fan Zhang
- Department of Chemical and Biological Engineering, Tufts University, Medford, Massachusetts
| | - Zijing Chen
- Department of Chemical and Biological Engineering, Tufts University, Medford, Massachusetts
| | - Emmanuel S Tzanakakis
- Department of Chemical and Biological Engineering, Tufts University, Medford, Massachusetts.,Clinical and Translational Science Institute, Tufts Medical Center, Boston, Massachusetts
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