Advances in our understanding of the pathophysiology of Type 1 diabetes: lessons from the NOD mouse

2013 ◽  
Vol 126 (1) ◽  
pp. 1-18 ◽  
Author(s):  
Abhirup Jayasimhan ◽  
Kristy P. Mansour ◽  
Robyn M. Slattery
Keyword(s):  
Type 1 Diabetes ◽  
Cell Mass ◽  
Nod Mice ◽  
Diabetic Mouse ◽  
Nod Mouse ◽  
Β Cells ◽  
Autoimmune Destruction ◽  
Immune Mediated ◽  
And Function

T1D (Type 1 diabetes) is an autoimmune disease caused by the immune-mediated destruction of pancreatic β-cells. Studies in T1D patients have been limited by the availability of pancreatic samples, a protracted pre-diabetic phase and limitations in markers that reflect β-cell mass and function. The NOD (non-obese diabetic) mouse is currently the best available animal model of T1D, since it develops disease spontaneously and shares many genetic and immunopathogenic features with human T1D. Consequently, the NOD mouse has been extensively studied and has made a tremendous contribution to our understanding of human T1D. The present review summarizes the key lessons from NOD mouse studies concerning the genetic susceptibility, aetiology and immunopathogenic mechanisms that contribute to autoimmune destruction of β-cells. Finally, we summarize the potential and limitations of immunotherapeutic strategies, successful in NOD mice, now being trialled in T1D patients and individuals at risk of developing T1D.

scholarly journals Detecting Insulitis in Type 1 Diabetes with Ultrasound Phase-change Contrast Agents

2020 ◽  
Author(s):  
David G. Ramirez ◽  
Awaneesh K. Upadhyay ◽  
Vinh T. Pham ◽  
Mark Ciccaglione ◽  
Mark A Borden ◽  
...  
Keyword(s):  
Type 1 Diabetes ◽  
Contrast Agents ◽  
Cell Mass ◽  
Nod Mice ◽  
Therapeutic Interventions ◽  
Β Cells ◽  
Β Cell ◽  
Diabetes Onset ◽  
Ultrasound Contrast

AbstractType 1 diabetes (T1D) results from immune infiltration and destruction of insulin-producing β-cells within the pancreatic islets of Langerhans (insulitis), resulting in loss of glucose homeostasis. Early diagnosis during pre-symptomatic T1D would allow for therapeutic intervention prior to substantial loss of β-cell mass at T1D onset. There are limited methods to track the progression of insulitis and β-cell mass decline in pre-symptomatic T1D. During insulitis, the islet microvasculature increases permeability, such that sub-micron sized particles can extravasate and accumulate within the islet microenvironment. Ultrasound is a widely deployable and cost-effective clinical imaging modality. However, conventional microbubble contrast agents are restricted to the vasculature. Sub-micron sized nanodroplet (ND) phasechange agents can be vaporized into micron-sized bubbles; serving as a circulating microbubble precursor. We tested if NDs extravasate into the immune-infiltrated islet microenvironment. We performed ultrasound contrast-imaging following ND infusion in NOD mice and NOD;Rag1ko controls, and tracked diabetes development. We measured the biodistribution of fluorescently labeled NDs, with histological analysis of insulitis. Ultrasound contrast signal was elevated in the pancreas of 10w NOD mice following ND infusion and vaporization, but was absent in both the non-infiltrated kidney of NOD mice and pancreas of Rag1ko controls. High contrast elevation also correlated with rapid diabetes onset. In pancreata of NOD mice, infiltrated islets and nearby exocrine tissue were selectively labeled with fluorescent NDs. Thus, contrast ultrasound imaging with ND phase-change agents can detect insulitis prior to diabetes onset. This will be important for monitoring disease progression to guide and assess preventative therapeutic interventions for T1D.SignificanceThere is a need for imaging methods to detect type1 diabetes (T1D) progression prior to clinical diagnosis. T1D is a chronic disease that results from autoreactive T cells infiltrating the islet of Langerhans and destroying insulin-producing β-cells. Overt disease takes years to present and is only diagnosed after significant β-cells loss. As such, the possibility of therapeutic intervention to preserve β-cell mass is hampered by an inability to follow pre-symptomatic T1D progression. There are immunotherapies that can delay T1D development. However identifying ‘at risk’ individuals, and tracking whether therapeutic interventions are impacting disease progression, prior to T1D onset, is lacking. A method to detect insulitis and β-cell mass decline would present an opportunity to guide therapeutic treatments to prevent T1D.

scholarly journals Innate Viral Sensor MDA5 and Coxsackievirus Interplay in Type 1 Diabetes Development

2020 ◽  
Vol 8 (7) ◽  
pp. 993
Author(s):  
Samuel I. Blum ◽  
Hubert M. Tse
Keyword(s):  
Type 1 Diabetes ◽  
Monozygotic Twins ◽  
Nucleotide Polymorphisms ◽  
Β Cells ◽  
Β Cell ◽  
Viral Dsrna ◽  
Antiviral Responses ◽  
Immune Mediated ◽  
And Function

Type 1 diabetes (T1D) is a polygenic autoimmune disease characterized by immune-mediated destruction of insulin-producing β-cells. The concordance rate for T1D in monozygotic twins is ≈30–50%, indicating that environmental factors also play a role in T1D development. Previous studies have demonstrated that enterovirus infections such as coxsackievirus type B (CVB) are associated with triggering T1D. Prior to autoantibody development in T1D, viral RNA and antibodies against CVB can be detected within the blood, stool, and pancreata. An innate pathogen recognition receptor, melanoma differentiation-associated protein 5 (MDA5), which is encoded by the IFIH1 gene, has been associated with T1D onset. It is unclear how single nucleotide polymorphisms in IFIH1 alter the structure and function of MDA5 that may lead to exacerbated antiviral responses contributing to increased T1D-susceptibility. Binding of viral dsRNA via MDA5 induces synthesis of antiviral proteins such as interferon-alpha and -beta (IFN-α/β). Viral infection and subsequent IFN-α/β synthesis can lead to ER stress within insulin-producing β-cells causing neo-epitope generation, activation of β-cell-specific autoreactive T cells, and β-cell destruction. Therefore, an interplay between genetics, enteroviral infections, and antiviral responses may be critical for T1D development.

scholarly journals NSC23766, a Known Inhibitor of Tiam1-Rac1 Signaling Module, Prevents the Onset of Type 1 Diabetes in the NOD Mouse Model

2016 ◽  
Vol 39 (2) ◽  
pp. 760-767 ◽  
Author(s):  
Rajakrishnan Veluthakal ◽  
Vaibhav Sidarala ◽  
Anjaneyulu Kowluru
Keyword(s):  
Type 1 Diabetes ◽  
Mouse Model ◽  
Spontaneous Diabetes ◽  
Nod Mice ◽  
Nod Mouse ◽  
Ros Generation ◽  
Β Cells ◽  
Chop Expression ◽  
Activation Assay

Background/Aims: Type 1 diabetes (T1D) is characterized by absolute insulin deficiency due to destruction of pancreatic β-cells by cytokines (e.g., interleukin-1β; IL-1β) released by invading immune cells. The mechanisms by which these cytokines induce β-cell dysfunction remain poorly understood. Recent evidence suggests that excessive generation of reactive oxygen species (ROS) by the phagocyte-like NADPH oxidase2 (Nox2), along with significantly low levels of antioxidants in β-cells, drive them toward oxidative damage. Rac1, a small G-protein, is one of the members of Nox2 holoenzyme. We recently reported that NSC23766, a known inhibitor of Rac1, significantly attenuated cytokine-induced Nox2 activation and ROS generation in pancreatic islet β-cells in vitro. Herein, we determined the effects of NSC23766 (2.5 mg/kg/day, i.p/daily) on the development of diabetes in the NOD mouse, a model for T1D. Methods: Two groups of experimental animals (Balb/c and NOD mice) received NSC23766, while the two control groups received equal volume of saline. Body weights and blood glucose were measured every week for 34 weeks. Rac1 activation in pancreatic islets was measured by GLISA activation assay. Rac1 and CHOP expression was determined by Western Blotting. Results: Our findings indicate that administration of NSC23766 significantly prevented the development of spontaneous diabetes in the NOD mice. Furthermore, NSC23766 markedly suppressed Rac1 expression and activity and the endoplasmic reticulum stress (CHOP expression) in NOD islets. Conclusions: Our findings provide the first evidence implicating the role of Tiam1-Rac1-Nox2 signaling pathway in the onset of spontaneous diabetes in the NOD mouse model.

scholarly journals Increased Incidence of Type 1 Diabetes during the COVID-19 Pandemic in Romanian Children

Medicina ◽  
2021 ◽  
Vol 57 (9) ◽  
pp. 973
Author(s):  
Adrian Vlad ◽  
Viorel Serban ◽  
Romulus Timar ◽  
Alexandra Sima ◽  
Veronica Botea ◽  
...  
Keyword(s):  
Type 1 Diabetes ◽  
Background Information ◽  
First Year ◽  
Age Group ◽  
Newly Diagnosed ◽  
Β Cells ◽  
Specific Antibodies ◽  
Autoimmune Destruction ◽  
Geographical Regions

Background and Objective: It is known that several viruses are involved in the pathogenesis of type 1 diabetes. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a new worldwide spread virus that may act as a trigger for the autoimmune destruction of the β-cells, as well, and thus lead to an increase in the incidence of type 1 diabetes. Material and Methods: The Romanian National Organization for the Protection of Children and Adolescents with Diabetes (ONROCAD) has collected information regarding new cases of type 1 diabetes in children aged 0 to 14 years from all over the country since 1996 and has computed the incidence of type 1 diabetes in this age group. Results: We observed a marked increase in the incidence of type 1 diabetes in the first year of the COVID-19 pandemic, with 16.9%, from 11.4/100,000 in 2019 to 13.3/100,000 in 2020, much higher compared to previous years (mean yearly increase was 5.1% in the period 1996–2015 and 0.8% in the interval 2015–2019). The proportion of newly diagnosed cases was significantly higher in the second half of 2020 compared to the second half of the previous years (57.8 vs. 51%, p < 0.0001). Conclusions: All these aspects suggest the role that SARS-CoV-2 could have in triggering pancreatic autoimmunity. To confirm this, however, collecting information from larger populations from different geographical regions, monitoring the incidence curves over a period of several years, and gathering background information on COVID-19 and/or data on COVID-19 specific antibodies are needed.

scholarly journals Epigallocatechin gallate delays the onset of type 1 diabetes in spontaneous non-obese diabetic mice

2010 ◽  
Vol 105 (8) ◽  
pp. 1218-1225 ◽  
Author(s):  
Zhuo Fu ◽  
Wei Zhen ◽  
Julia Yuskavage ◽  
Dongmin Liu
Keyword(s):  
Type 1 Diabetes ◽  
Cell Mass ◽  
Epigallocatechin Gallate ◽  
Nod Mice ◽  
Cost Effective ◽  
Treated Group ◽  
Control Group ◽  
Plasma Insulin Levels ◽  
Glucose Lowering Effect

Type 1 diabetes (T1D) results from the autoimmune-mediated destruction of pancreatic β-cells, leading to deficiency of insulin production. Successful islet transplantation can normalise hyperglycaemia in T1D patients; however, the limited availability of the islets, loss of islet cell mass through apoptosis after islet isolation and potential autoimmune destruction of the transplanted islets prevent the widespread use of this procedure. Therefore, the search for novel and cost-effective agents that can prevent or treat T1D is extremely important to decrease the burden of morbidity from this disease. In the present study, we discovered that ( − )-epigallocatechin gallate (EGCG, 0·05 % in drinking-water), the primary polyphenolic component in green tea, effectively delayed the onset of T1D in non-obese diabetic (NOD) mice. At 32 weeks of age, eight (66·7 %) out of twelve mice in the control group developed diabetes, whereas only three (25 %) out of twelve mice in the EGCG-treated group became diabetic (P < 0·05). Consistently, mice supplemented with EGCG had significantly higher plasma insulin levels and survival rate but lower glycosylated Hb concentrations compared with the control animals. EGCG had no significant effects on food or water intake and body weight in mice, suggesting that the glucose-lowering effect was not due to an alteration in these parameters. While EGCG did not modulate insulitis, it elevated the circulating anti-inflammatory cytokine IL-10 level in NOD mice. These findings demonstrate that EGCG may be a novel, plant-derived compound capable of reducing the risk of T1D.

scholarly journals Gene Transfection and Expression of Transforming Growth Factor-β1 in Nonobese Diabetic Mouse Islets Protects β-Cells in Syngeneic Islet Grafts from Autoimmune Destruction

2002 ◽  
Vol 11 (6) ◽  
pp. 519-528 ◽  
Author(s):  
Wilma L. Suarez-Pinzon ◽  
Yvonne Marcoux ◽  
Aziz Ghahary ◽  
Alex Rabinovitch
Keyword(s):  
Transforming Growth Factor ◽  
Islet Cells ◽  
Gene Transfection ◽  
Nod Mice ◽  
Nod Mouse ◽  
Β Cells ◽  
Nonobese Diabetic ◽  
Autoimmune Destruction ◽  
Mouse Islets ◽  
Tgf Β1

Nonobese diabetic (NOD) mice develop diabetes and destroy syngeneic islet grafts through an autoimmune response. Because transforming growth factor (TGF)-β1 downregulates immune responses, we tested whether overexpression of TGF-β1 by gene transfection of NOD mouse islets could protect β-cells in islet grafts from autoimmune destruction. NOD mouse islet cells were transfected with an adenoviral DNA expression vector encoding porcine latent TGF-β1 (Ad TGF- β1) or the adenoviral vector alone (control Ad vector). The frequency of total islet cells expressing TGF-1 protein was increased from 12±1% in control Ad vector-transfected cells to 89 ± 4% in Ad TGF-β1-transfected islet cells, and the frequency of β-cells that expressed TGF-β1 was increased from 12 ± 1% to 60 ± 7%. Also, secretion of TGF-β1 was significantly increased in islets that overexpressed TGF-β1. Ad TGF-β1-transfected NOD mouse islets that overexpressed TGF-β1 prevented diabetes recurrence after transplantation into diabetic NOD mice for a median of 22 days compared with only 7 days for control Ad vector-transfected islets (p = 0.001). Immunohistochemical examination of the islet grafts revealed significantly more TGF-β1+ cells and insulin+ cells and significantly fewer CD45+ leukocytes in Ad TGF-β1-transfected islet grafts. Also, islet β-cell apoptosis was significantly decreased whereas apoptosis of graft-infiltrating leukocytes was significantly increased in Ad TGF-β1-transfected islet grafts. These observations demonstrate that overexpression of TGF-β1, by gene transfection of NOD mouse islets, protects islet β-cells from apoptosis and autoimmune destruction and delays diabetes recurrence after islet transplantation.

scholarly journals Distinct Roles of β-Cell Mass and Function During Type 1 Diabetes Onset and Remission

Diabetes ◽  
2015 ◽  
Vol 64 (6) ◽  
pp. 2148-2160 ◽  
Author(s):  
Helena Chmelova ◽  
Christian M. Cohrs ◽  
Julie A. Chouinard ◽  
Cathleen Petzold ◽  
Matthias Kuhn ◽  
...  
Keyword(s):  
Type 1 Diabetes ◽  
Cell Mass ◽  
Β Cell ◽  
Diabetes Onset ◽  
And Function

Harnessing immune cells to enhance β-cell mass in type 1 diabetes

2016 ◽  
Vol 64 (1) ◽  
pp. 14-20 ◽  
Author(s):  
Ercument Dirice ◽  
Rohit N Kulkarni
Keyword(s):  
Type 1 Diabetes ◽  
Mononuclear Cells ◽  
Islet Cells ◽  
Cell Mass ◽  
Cell Loss ◽  
Cell Types ◽  
Β Cells ◽  
Β Cell ◽  
Autoimmune Attack

Type 1 diabetes is characterized by early β-cell loss leading to insulin dependence in virtually all patients with the disease in order to maintain glucose homeostasis. Most studies over the past few decades have focused on limiting the autoimmune attack on the β cells. However, emerging data from patients with long-standing diabetes who continue to harbor functional insulin-producing cells in their diseased pancreas have prompted scientists to examine whether proliferation of existing β cells can be enhanced to promote better glycemic control. In support of this concept, several studies indicate that mononuclear cells that infiltrate the islets have the capacity to trigger proliferation of islet cells including β cells. These observations indicate the exciting possibility of identifying those mononuclear cell types and their soluble factors and harnessing their ability to promote β-cell growth concomitant with autoimmune therapy to prevent the onset and/or halt the progression of the disease.

scholarly journals Dextran Sulfate Protects Pancreatic β-Cells, Reduces Autoimmunity and Ameliorates Type 1 Diabetes

2020 ◽  
Author(s):  
Ada Admin ◽  
Geming Lu ◽  
Francisco Rausell-Palamos ◽  
Jiamin Zhang ◽  
Zihan Zheng ◽  
...  
Keyword(s):  
T Cells ◽  
Type 1 Diabetes ◽  
Heparan Sulfate ◽  
Dextran Sulfate ◽  
Nod Mice ◽  
Β Cells ◽  
Β Cell ◽  
Pancreatic Β Cells

A failure in self-tolerance leads to autoimmune destruction of pancreatic β-cells and type 1 diabetes (T1D). Low molecular weight dextran sulfate (DS) is a sulfated semi-synthetic polysaccharide with demonstrated cytoprotective and immunomodulatory properties <i>in vitro</i>. However, whether DS can protect pancreatic β-cells, reduce autoimmunity and ameliorate T1D is unknown. Here we report that DS, but not dextran, protects human β-cells against cytokine-mediated cytotoxicity <i>in vitro</i>. DS also protects mitochondrial function and glucose-stimulated insulin secretion and reduces chemokine expression in human islets in a pro-inflammatory environment. Interestingly, daily treatment with DS significantly reduces diabetes incidence in pre-diabetic non-obese diabetic (NOD) mice, and most importantly, reverses diabetes in early-onset diabetic NOD mice. DS decreases β-cell death, enhances islet heparan sulfate (HS)/heparan sulfate proteoglycan (HSPG) expression and preserves β-cell mass and plasma insulin in these mice. DS administration also increases the expression of the inhibitory co-stimulatory molecule programmed death-1 (PD-1) in T-cells, reduces interferon-γ+ CD4+ and CD8+ T-cells and enhances the number of FoxP3+ cells. Collectively, these studies demonstrate that the action of one single molecule, DS, on β-cell protection, extracellular matrix preservation and immunomodulation can reverse diabetes in NOD mice highlighting its therapeutic potential for the treatment of T1D.

scholarly journals TLR9-deficiency in B cells Promotes Immune Tolerance via IL-10 in a Type 1 Diabetes Mouse Model

2020 ◽  
Author(s):  
Ada Admin ◽  
Sha Sha ◽  
James A Pearson ◽  
Jian Peng ◽  
Youjia Hu ◽  
...  
Keyword(s):  
Type 1 Diabetes ◽  
B Cells ◽  
B Cell ◽  
Nod Mice ◽  
Adaptive Immune ◽  
Immune Molecule ◽  
And Function ◽  
Intrinsic Effect ◽  
Specific Deletion

Toll-like receptor 9 (TLR9) is highly expressed in B cells and B cells are important in the pathogenesis of type 1 diabetes (T1D) development. However, the intrinsic effect of TLR9 in B cells on beta cell autoimmunity is not known. To fill this knowledge gap, we generated non-obese diabetic (NOD) mice with a B cell-specific deficiency of TLR9 (TLR9<sup>fl/fl</sup>/CD19-Cre+ NOD). The B cell-specific deletion of TLR9 resulted in near complete protection from T1D development. Diabetes protection was accompanied by an increased proportion of IL-10-producing B cells. We also found that TLR9-deficient B cells were hyporesponsive to both innate and adaptive immune-stimuli. This suggested that TLR9 in B cells modulates T1D susceptibility in NOD mice by changing the frequency and function of IL-10-producing B cells. Molecular analysis revealed a network of TLR9 with MMPs, TIMP1 and CD40, all of which are inter-connected with IL-10. Our study has highlighted an important connection of an innate immune molecule in B cells to the immuno-pathogenesis of T1D. Thus, targeting the TLR9 pathway, specifically in B cells, may provide a novel therapeutic strategy for T1D treatment.

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