1
|
Morrish F, Gingras H, Noonan J, Huang L, Sweet IR, Kuok IT, Knoblaugh SE, Hockenbery DM. Mitochondrial diabetes in mice expressing a dominant-negative allele of nuclear respiratory factor-1 ( Nrf1 ) in pancreatic β-cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.22.524153. [PMID: 38014068 PMCID: PMC10680558 DOI: 10.1101/2023.01.22.524153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Genetic polymorphisms in nuclear respiratory factor-1 ( NRF1 ), a key transcriptional regulator of nuclear-encoded mitochondrial proteins, have been linked to diabetes. Homozygous deletion of Nrf1 is embryonic lethal in mice. Our goal was to generate mice with β-cell-specific reduction in NRF1 function to investigate the relationship between NRF1 and diabetes. We report the generation of mice expressing a dominant-negative allele of Nrf1 (DNNRF1) in pancreatic β-cells. Heterozygous transgenic mice had high fed blood glucose levels detected at 3 wks of age, which persisted through adulthood. Plasma insulin levels in DNNRF1 transgenic mice were reduced, while insulin sensitivity remained intact in young animals. Islet size was reduced with increased numbers of apoptotic cells, and insulin content in islets by immunohistochemistry was low. Glucose-stimulated insulin secretion in isolated islets was reduced in DNNRF1-mice, but partially rescued by KCl, suggesting that decreased mitochondrial function contributed to the insulin secretory defect. Electron micrographs demonstrated abnormal mitochondrial morphology in β- cells. Expression of NRF1 target genes Tfam , T@1m and T@2m , and islet cytochrome c oxidase and succinate dehydrogenase activities were reduced in DNNRF1-mice. Rescue of mitochondrial function with low level activation of transgenic c-Myc in β-cells was sufficient to restore β-cell mass and prevent diabetes. This study demonstrates that reduced NRF1 function can lead to loss of β-cell function and establishes a model to study the interplay between regulators of bi- genomic gene transcription in diabetes.
Collapse
|
2
|
DiNicolantonio JJ, McCarty M. Autophagy-induced degradation of Notch1, achieved through intermittent fasting, may promote beta cell neogenesis: implications for reversal of type 2 diabetes. Open Heart 2019; 6:e001028. [PMID: 31218007 PMCID: PMC6546199 DOI: 10.1136/openhrt-2019-001028] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/06/2019] [Indexed: 02/06/2023] Open
|
3
|
Decreased STARD10 Expression Is Associated with Defective Insulin Secretion in Humans and Mice. Am J Hum Genet 2017; 100:238-256. [PMID: 28132686 PMCID: PMC5294761 DOI: 10.1016/j.ajhg.2017.01.011] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Accepted: 12/20/2016] [Indexed: 12/30/2022] Open
Abstract
Genetic variants near ARAP1 (CENTD2) and STARD10 influence type 2 diabetes (T2D) risk. The risk alleles impair glucose-induced insulin secretion and, paradoxically but characteristically, are associated with decreased proinsulin:insulin ratios, indicating improved proinsulin conversion. Neither the identity of the causal variants nor the gene(s) through which risk is conferred have been firmly established. Whereas ARAP1 encodes a GTPase activating protein, STARD10 is a member of the steroidogenic acute regulatory protein (StAR)-related lipid transfer protein family. By integrating genetic fine-mapping and epigenomic annotation data and performing promoter-reporter and chromatin conformational capture (3C) studies in β cell lines, we localize the causal variant(s) at this locus to a 5 kb region that overlaps a stretch-enhancer active in islets. This region contains several highly correlated T2D-risk variants, including the rs140130268 indel. Expression QTL analysis of islet transcriptomes from three independent subject groups demonstrated that T2D-risk allele carriers displayed reduced levels of STARD10 mRNA, with no concomitant change in ARAP1 mRNA levels. Correspondingly, β-cell-selective deletion of StarD10 in mice led to impaired glucose-stimulated Ca2+ dynamics and insulin secretion and recapitulated the pattern of improved proinsulin processing observed at the human GWAS signal. Conversely, overexpression of StarD10 in the adult β cell improved glucose tolerance in high fat-fed animals. In contrast, manipulation of Arap1 in β cells had no impact on insulin secretion or proinsulin conversion in mice. This convergence of human and murine data provides compelling evidence that the T2D risk associated with variation at this locus is mediated through reduction in STARD10 expression in the β cell.
Collapse
|
4
|
Aref ABM, Ahmed OM, Ali LA, Semmler M. Maternal rat diabetes mellitus deleteriously affects insulin sensitivity and Beta-cell function in the offspring. J Diabetes Res 2013; 2013:429154. [PMID: 23998129 PMCID: PMC3753768 DOI: 10.1155/2013/429154] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Revised: 05/09/2013] [Accepted: 05/19/2013] [Indexed: 12/16/2022] Open
Abstract
This study was designed to assess the effect of maternal diabetes in rats on serum glucose and insulin concentrations, insulin resistance, histological architecture of pancreas and glycogen content in liver of offspring. The pregnant rat females were allocated into two main groups: normal control group and streptozotocin-induced diabetic group. After birth, the surviving offspring were subjected to biochemical and histological examination immediately after delivery and at the end of the 1st and 2nd postnatal weeks. In comparison with the offspring of normal control dams, the fasting serum glucose level of offspring of diabetic mothers was significantly increased at the end of the 1st and 2nd postnatal weeks. Serum insulin level of offspring of diabetic dams was significantly higher at birth and decreased significantly during the following 2 postnatal weeks, while in normal rat offspring, it was significantly increased with progress of time. HOMA Insulin Resistance (HOMA-IR) was significantly increased in the offspring of diabetic dams at birth and after 1 week than in normal rat offspring, while HOMA insulin sensitivity (HOMA-IS) was significantly decreased. HOMA beta-cell function was significantly decreased at all-time intervals in offspring of diabetic dams. At birth, islets of Langerhans as well as beta cells in offspring of diabetic dams were hypertrophied. The cells constituting islets seemed to have a high division rate. However, beta-cells were degenerated during the following 2 post-natal weeks and smaller insulin secreting cells predominated. Vacuolation and necrosis of the islets of Langerhans were also observed throughout the experimental period. The carbohydrate content in liver of offspring of diabetic dams was at all-time intervals lower than that in control. The granule distribution was more random. Overall, the preexisting maternal diabetes leads to glucose intolerance, insulin resistance, and impaired insulin sensitivity and β -cell function in the offspring at different postnatal periods.
Collapse
Affiliation(s)
- Abdel-Baset M. Aref
- Cell Biology and Histochemistry Division, Zoology Department, Faculty of Science, South Valley University, Qena, Egypt
| | - Osama M. Ahmed
- Physiology Division, Zoology Department, Faculty of Science, Beni-Suef University, Salah Salem Street, P.O. Box 62514, Beni-Suef, Egypt
- Faculty of Oral and Dental Medicine, Nahda University, New Beni-Suef City, Beni-Suef, Egypt
| | - Lobna A. Ali
- Cell Biology and Histochemistry Division, Zoology Department, Faculty of Science, South Valley University, Qena, Egypt
| | | |
Collapse
|
5
|
Han J, Xu J, Long YS, Epstein PN, Liu YQ. Rat maternal diabetes impairs pancreatic beta-cell function in the offspring. Am J Physiol Endocrinol Metab 2007; 293:E228-36. [PMID: 17389712 DOI: 10.1152/ajpendo.00479.2006] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
It has been shown that maternal diabetes increases the risk for obesity, glucose intolerance, and Type 2 diabetes mellitus in the adult life of the offspring. Mechanisms for these effects on the offspring are not well understood, and little information is available to reveal the mechanisms. We studied the effect of maternal diabetes on beta-cell function in the offspring of streptozotocin (STZ)-induced diabetic rat mothers (STZ-offspring). STZ-offspring did not become glucose intolerant up to 15 wk of age. At this age, however, insulin secretion was significantly impaired, as measured by in vivo and in vitro studies. Consistent with these changes, islet glucose metabolism and some important glucose metabolic enzyme activities were reduced. No significant changes were found in islet morphological analysis. These data indicate that beta-cell function is impaired in adult STZ-offspring; these changes may contribute to the development of type 2 diabetes mellitus in adulthood.
Collapse
Affiliation(s)
- Junying Han
- Kosair Children's Hospital Research Institute, Department of Pediatrics, University of Louisville College of Medicine, 570 South Preston St., Suite 304, Louisville, KY 40202, USA
| | | | | | | | | |
Collapse
|
6
|
Mobbs CV, Mastaitis JW, Zhang M, Isoda F, Cheng H, Yen K. Secrets of the lac operon. Glucose hysteresis as a mechanism in dietary restriction, aging and disease. INTERDISCIPLINARY TOPICS IN GERONTOLOGY 2006; 35:39-68. [PMID: 17063032 PMCID: PMC2755292 DOI: 10.1159/000096555] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Elevated blood glucose associated with diabetes produces progressive and apparently irreversible damage to many cell types. Conversely, reduction of glucose extends life span in yeast, and dietary restriction reduces blood glucose. Therefore it has been hypothesized that cumulative toxic effects of glucose drive at least some aspects of the aging process and, conversely, that protective effects of dietary restriction are mediated by a reduction in exposure to glucose. The mechanisms mediating cumulative toxic effects of glucose are suggested by two general principles of metabolic processes, illustrated by the lac operon but also observed with glucose-induced gene expression. First, metabolites induce the machinery of their own metabolism. Second, induction of gene expression by metabolites can entail a form of molecular memory called hysteresis. When applied to glucose-regulated gene expression, these two principles suggest a mechanism whereby repetitive exposure to postprandial excursions of glucose leads to an age-related increase in glycolytic capacity (and reduction in beta-oxidation of free fatty acids), which in turn leads to an increased generation of oxidative damage and a decreased capacity to respond to oxidative damage, independent of metabolic rate. According to this mechanism, dietary restriction increases life span and reduces pathology by reducing exposure to glucose and therefore delaying the development of glucose-induced glycolytic capacity.
Collapse
Affiliation(s)
- Charles V Mobbs
- Departments of Neuroscience and Geriatrics, Mount Sinai School of Medicine, 1 Gustave L. Levy Place, New York, NY 10029, USA.
| | | | | | | | | | | |
Collapse
|
7
|
Dwyer DS, Donohoe D, Lu XH, Aamodt EJ. Mechanistic Connections between Glucose/Lipid Disturbances and Weight Gain induced by Antipsychotic Drugs. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2005; 65:211-47. [PMID: 16140058 DOI: 10.1016/s0074-7742(04)65008-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Donard S Dwyer
- Department of Psychiatry, Louisiana State University Health Sciences Center, Shreveport, Louisiana 71130, USA
| | | | | | | |
Collapse
|
8
|
Lawrence JTR, Birnbaum MJ. ADP-ribosylation factor 6 regulates insulin secretion through plasma membrane phosphatidylinositol 4,5-bisphosphate. Proc Natl Acad Sci U S A 2003; 100:13320-5. [PMID: 14585928 PMCID: PMC263800 DOI: 10.1073/pnas.2232129100] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
ADP-ribosylation factor 6 (ARF6) is a small GTP-binding protein that regulates peripheral vesicular trafficking and actin cytoskeletal dynamics, and it has been implicated as critical to regulated secretion. Expression of a dominant-inhibitory ARF6 mutant, ARF6(T27N), impaired glucose-, depolarization-, and gamma-thio-GTP-stimulated insulin secretion in the pancreatic beta cell line, MIN6. In response to depolarization, MIN6 cells expressing ARF6(T27N) displayed an unaltered initial fast phase but an impaired subsequent slow phase of insulin secretion. Actin cytoskeletal disassembly with latrunculin A enhanced insulin secretion, whereas stabilization with jasplakinolide inhibited secretion, consistent with the actin cytoskeleton serving as a barrier to exocytosis in these cells. ARF6(T27N) led to a depolarization-dependent reduction in the levels of phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] with a time course that paralleled the inhibition of secretion. Moreover, blockade of PI(4,5)P2-dependent events by expression of a lipid-binding protein resulted in inhibition of depolarization-induced secretion in a manner identical to ARF6(T27N). These results indicate that ARF6 is required to sustain adequate levels of PI(4,5)P2 during periods of increased PI(4,5)P2 metabolism such as regulated secretion.
Collapse
Affiliation(s)
- John T R Lawrence
- Howard Hughes Medical Institute, The Cox Institute, Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
| | | |
Collapse
|
9
|
Giannoukakis N, Robbins PD. Gene and cell therapies for diabetes mellitus: strategies and clinical potential. BioDrugs 2003; 16:149-73. [PMID: 12102644 DOI: 10.2165/00063030-200216030-00001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The last 5 years have witnessed an explosion in the use of genes and cells as biomedicines. While primarily aimed at cancer, gene engineering and cell therapy strategies have additionally been used for Mendelian, neurodegenerative and metabolic disorders. The main focus of gene and cell therapy strategies in metabolism has been diabetes mellitus. This disease is a disorder of glucose homeostasis, either due to the immune-mediated eradication of pancreatic beta cells in the islets of Langerhans (type 1 diabetes) or resulting from insulin resistance and obesity syndromes where the insulin-producing capability of the beta cell is ultimately exhausted in the face of insensitivity to the effects of insulin in the peripheral glucose-utilising tissues (type 2 diabetes). A significant number of animal studies have demonstrated the potential in restoring normoglycaemia by islet transplantation in the context of immunoregulation achieved by gene transfer of immunoregulatory genes to allo- and xenogeneic islets ex vivo. Additionally, gene and cell therapy has also been used to induce tolerance to auto- and alloantigens and to generate the tolerant state in autoimmune rodent animal models of type 1 diabetes or rodent recipients of allogeneic/xenogeneic islet transplants. The achievements of gene and cell therapy in type 2 diabetes are less evident, but seminal studies promise that this modality can be relevant to treat and perhaps prevent the underlying causes of the disease. Here we present an overview of the current status of gene and cell therapy for type 1 and 2 diabetes and we propose potential therapeutic options that could be clinically useful. For type 1 diabetes, transplantation of islets engineered to evade or suppress the recipient immune response is the most readily-available technology today. A number of gene delivery vectors encoding proteins that impair a variety of immune cells have already been examined and proven versatile. More challenging but, nonetheless, just over the horizon are attempts to promote tolerance to islet allografts. Type 2 diabetes will likely require a better understanding of the processes that determine insulin sensitivity in the periphery. Targeting tissues such as muscle and fat with vectors encoding genes whose products promote insulin sensitivity and glucose uptake is an approach that does not carry with it the side-effects often associated with pharmacologic agents currently in use. In the end, progress in vector design, elucidation of antigen-specific immunity and insulin sensitivity will provide the framework for gene drug use in the treatment of type 1 and type 2 diabetes.
Collapse
Affiliation(s)
- Nick Giannoukakis
- Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213, USA.
| | | |
Collapse
|
10
|
Abstract
The list of Ca(2+) channels involved in stimulus-secretion coupling in beta-cells is increasing. In this respect the roles of the voltage-gated Ca(2+) channels and IP(3) receptors are well accepted. There is a lack of consensus about the significance of a third group of Ca(2+) channels called ryanodine (RY) receptors. These are large conduits located on Ca(2+) storage organelle. Ca(2+) gates these channels in a concentration- and time-dependent manner. Activation of these channels by Ca(2+) leads to fast release of Ca(2+) from the stores, a process called Ca(2+)-induced Ca(2+) release (CICR). A substantial body of evidence confirms that beta-cells have RY receptors. CICR by RY receptors amplifies Ca(2+) signals. Some properties of RY receptors ensure that this amplification process is engaged in a context-dependent manner. Several endogenous molecules and processes that modulate RY receptors determine the appropriate context. Among these are several glycolytic intermediates, long-chain acyl CoA, ATP, cAMP, cADPR, NO, and high luminal Ca(2+) concentration, and all of these have been shown to sensitize RY receptors to the trigger action of Ca(2+). RY receptors, thus, detect co-incident signals and integrate them. These Ca(2+) channels are targets for the action of cAMP-linked incretin hormones that stimulate glucose-dependent insulin secretion. In beta-cells some RY receptors are located on the secretory vesicles. Thus, despite their low abundance, RY receptors are emerging as distinct players in beta-cell function by virtue of their large conductance, strategic locations, and their ability to amplify Ca(2+) signals in a context-dependent manner.
Collapse
Affiliation(s)
- Md Shahidul Islam
- Department of Molecular Medicine, Karolinska Institutet, Department of Endocrinology, Karolinska Hospital, Stockholm, Sweden.
| |
Collapse
|
11
|
Shiraishi A, Yamada Y, Tsuura Y, Fijimoto S, Tsukiyama K, Mukai E, Toyoda Y, Miwa I, Seino Y. A novel glucokinase regulator in pancreatic beta cells: precursor of propionyl-CoA carboxylase beta subunit interacts with glucokinase and augments its activity. J Biol Chem 2001; 276:2325-8. [PMID: 11085976 DOI: 10.1074/jbc.c000530200] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A glucokinase regulatory protein has been reported to exist in the liver, which suppresses enzyme activity in a complex with fructose 6-phosphate, whereas no corresponding protein has been found in pancreatic beta cells. To search for such a protein in pancreatic beta cells, we screened for a cDNA library of the HIT-T15 cell line with the cDNA of glucokinase from rat islet by the yeast two hybrid system. We detected a cDNA encoding the precursor of propionyl-CoA carboxylase beta subunit (pbetaPCCase), and glutathione S-transferase pull-down assay illustrated that pbetaPCCase interacted with recombinant rat islet glucokinase and with glucokinase in rat liver and islet extracts. Functional analysis indicated that pbetaPCCase decreased the K(m) value of recombinant islet glucokinase for glucose by 18% and increased V(max) value by 23%. We concluded that pbetaPCCase might be a novel activator of glucokinase in pancreatic beta cells.
Collapse
Affiliation(s)
- A Shiraishi
- Department of Metabolism and Clinical Nutrition, Graduate School of Medicine, Kyoto University, Sakyoku, Japan.
| | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Abstract
The term "bioartificial endocrine pancreas" (BEP) was introduced by Anthony Sun in 1980. It was in 1968, however, that Thomas Chang proposed the use of microencapsulated islets as artificial beta-cells. By applying a semipermeable membrane on the top of microcapsules, a system can be produced that is impermeable to viable islet cells and large effector molecules of the immune system, thus providing a protection for transplanted islets against rejection. Since then, the term BEP has not often appeared in papers. Instead, the term "bioartificial pancreas" (BAP) has gained widespread use. In a broader sense, BAP would include an application of suitable endocrine cells and protective polymeric vehicles, but not necessarily providing a filtration barrier of precisely defined properties (e.g., cells injected into a gel of hyaluronate).
Collapse
Affiliation(s)
- A Prokop
- Chemical Engineering Department, Vanderbilt University, Nashville, TN 37235, USA.
| |
Collapse
|
13
|
Hanover JA, Lai Z, Lee G, Lubas WA, Sato SM. Elevated O-linked N-acetylglucosamine metabolism in pancreatic beta-cells. Arch Biochem Biophys 1999; 362:38-45. [PMID: 9917327 DOI: 10.1006/abbi.1998.1016] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
High intracellular glucose concentrations increase flux though the hexosamine biosynthetic pathway, resulting in elevated UDP-N-acetylglucosamine (GlcNAc) concentrations. The nucleocytoplasmic enzyme O-linked N-acetylglucosaminyltransferase (OGT) uses UDP-GlcNAc as a donor to modify numerous critical substrates, including nuclear pore proteins and transcription factors. Here, we document (a) the overwhelming enrichment of pancreatic OGT transcripts in the beta-cells of the islets of Langerhans, (b) the physiologically significant increase in the level of O-GlcNAc residues present in beta-cells, and (c) the action of streptozotocin, a close analogue of GlcNAc, to selectively inhibit O-GlcNAcase, an enzyme involved in the removal of O-GlcNAc residues. Taken together, these findings suggest that pancreatic beta cells maintain a highly elevated O-GlcNAc metabolism and that the diabetes inducing drug streptozotocin inhibits O-GlcNAcase.
Collapse
Affiliation(s)
- J A Hanover
- Laboratory of Cell Biochemistry and Biology, NIDDK, National Institutes of Health, Bethesda, Maryland, 20892, USA.
| | | | | | | | | |
Collapse
|