scholarly journals Adenoviral-Mediated Transduction of Human Pancreatic Islets: Importance of Adenoviral Genome for Cell Viability and Association with a Deficient Antiviral Response

Endocrinology ◽  
2005 ◽  
Vol 146 (5) ◽  
pp. 2406-2414 ◽  
Author(s):  
Andreea R. Barbu ◽  
Göran Akusjärvi ◽  
Nils Welsh
Keyword(s):  
Pancreatic Islets ◽  
Genetic Manipulation ◽  
Islet Cells ◽  
Antiviral Response ◽  
Β Cells ◽  
Need To Evaluate ◽  
Exogenous Addition ◽  
E3 Region

Abstract As adenoviral vectors are extensively used for genetic manipulation of insulin-producing cells in vitro, there is an increasing need to evaluate their effects on the function, morphology, and viability of transduced pancreatic islets. In the present study we observed that specific adenoviral genotypes, carrying E4 and E1/E3 deletions, correlate with differential induction of necrosis in pancreatic islet cells. In particular, the adenovirus death protein encoded from the E3 region of the adenoviral genome was able to modulate the changes induced in the morphology and viability of the transduced cells. We also propose a putative role for the transcriptional regulator pIX. Although human islet cells showed an increased resistance in terms of viral concentrations required for the induction of cell toxicity, our results showed that they were unable to build up an efficient antiviral response after transduction and that their survival was dependent on the exogenous addition of α-interferon. An intact and fully functional β-cell is crucial for the successful application of gene therapy approaches in type 1 diabetes, and therefore, the implications of our findings need to be considered when designing vectors for gene transfer into pancreatic β-cells.

scholarly journals Increased expression of viral sensor MDA5 in pancreatic islets and in hormone-negative endocrine cells in recent onset type 1 diabetic donors

2021 ◽  
Author(s):  
Laura Nigi ◽  
Noemi Brusco ◽  
Giuseppina Emanuela Grieco ◽  
Daniela Fignani ◽  
Giada Licata ◽  
...  
Keyword(s):  
Pancreatic Islets ◽  
Endocrine Cells ◽  
Viral Infections ◽  
Islet Cells ◽  
Diabetic Control ◽  
Imaging Analysis ◽  
Β Cells ◽  
Recent Onset ◽  
Genetic And Environmental Factors

The interaction between genetic and environmental factors determines the development of type 1 diabetes (T1D). Some viruses are capable of infecting and damaging pancreatic β-cells, whose antiviral response could be modulated by specific viral RNA receptors and sensors such as Melanoma Differentiation Associated gene 5 (MDA5), encoded by the IFIH1 gene. MDA5 has been shown to be involved in pro-inflammatory and immunoregulatory outcomes, thus determining the response of pancreatic islets to viral infections. Although the function of MDA5 has been previously well explored, a detailed immunohistochemical characterization of MDA5 in pancreatic tissues of non-diabetic and T1D donors is still missing. In the present study we used multiplex immunofluorescence imaging analysis to characterize MDA5 expression and distribution in pancreatic tissues obtained from 22 organ donors (10 non-diabetic autoantibody-negative, 2 autoantibody-positive, 8 recent-onset and 2 long-standing T1D). In non-diabetic control donors, MDA5 was expressed both in α- and in β-cells. The colocalization rate imaging analysis showed that MDA5 was preferentially expressed in α-cells. In T1D donors, we observed an increased colocalization rate MDA5-glucagon respect to MDA5-insulin in comparison to non-diabetic controls; such increase was more pronounced in recent onset respect to long standing T1D donors. Of note, an increased colocalization rate MDA5-glucagon was found in insulin-deficient-islets (IDI) respect to insulin containing islets (ICI). Strikingly, in T1D donors we detected the presence of MDA5-positive/hormones-negative endocrine islet-like clusters, putatively deriving from dedifferentiation or neogenesis phoenomena. These clusters were exclusively identified in recent onset donors and not detected in autoantibody-positive non-diabetic or T1D long-standing ones. In conclusion, we showed that MDA5 is preferentially expressed in α-cells and its expression is increased in recent onset T1D donors. Finally, we observed that MDA5 may also characterize the phenotype of dedifferentiated or newly forming islet cells, thus opening to novel roles for MDA5 in pancreatic endocrine cells.

scholarly journals Development of a Bioartificial Vascular Pancreas

2021 ◽  
Vol 12 ◽  
pp. 204173142110277
Author(s):  
Edward X Han ◽  
Juan Wang ◽  
Mehmet Kural ◽  
Bo Jiang ◽  
Katherine L Leiby ◽  
...  
Keyword(s):  
Type 1 Diabetes ◽  
Pancreatic Islets ◽  
Vascular Graft ◽  
Term Treatment ◽  
Diffusion Limitations ◽  
Human Scale ◽  
Arterial Blood ◽  
Long Term Treatment

Transplantation of pancreatic islets has been shown to be effective, in some patients, for the long-term treatment of type 1 diabetes. However, transplantation of islets into either the portal vein or the subcutaneous space can be limited by insufficient oxygen transfer, leading to islet loss. Furthermore, oxygen diffusion limitations can be magnified when islet numbers are increased dramatically, as in translating from rodent studies to human-scale treatments. To address these limitations, an islet transplantation approach using an acellular vascular graft as a vascular scaffold has been developed, termed the BioVascular Pancreas (BVP). To create the BVP, islets are seeded as an outer coating on the surface of an acellular vascular graft, using fibrin as a hydrogel carrier. The BVP can then be anastomosed as an arterial (or arteriovenous) graft, which allows fully oxygenated arterial blood with a pO2 of roughly 100 mmHg to flow through the graft lumen and thereby supply oxygen to the islets. In silico simulations and in vitro bioreactor experiments show that the BVP design provides adequate survivability for islets and helps avoid islet hypoxia. When implanted as end-to-end abdominal aorta grafts in nude rats, BVPs were able to restore near-normoglycemia durably for 90 days and developed robust microvascular infiltration from the host. Furthermore, pilot implantations in pigs were performed, which demonstrated the scalability of the technology. Given the potential benefits provided by the BVP, this tissue design may eventually serve as a solution for transplantation of pancreatic islets to treat or cure type 1 diabetes.

scholarly journals Regulation of glucokinase in pancreatic islets by prolactin: a mechanism for increasing glucose-stimulated insulin secretion during pregnancy

2007 ◽  
Vol 193 (3) ◽  
pp. 367-381 ◽  
Author(s):  
Anthony J Weinhaus ◽  
Laurence E Stout ◽  
Nicholas V Bhagroo ◽  
T Clark Brelje ◽  
Robert L Sorenson
Keyword(s):  
Insulin Secretion ◽  
Glucose Metabolism ◽  
Pancreatic Islets ◽  
Glucose Transporter ◽  
Β Cells ◽  
Glucose Transporter 2 ◽  
Underlying Mechanisms ◽  
Glucose Stimulated Insulin Secretion ◽  
Induced Changes

Glucokinase activity is increased in pancreatic islets during pregnancy and in vitro by prolactin (PRL). The underlying mechanisms that lead to increased glucokinase have not been resolved. Since glucose itself regulates glucokinase activity in β-cells, it was unclear whether the lactogen effects are direct or occur through changes in glucose metabolism. To clarify the roles of glucose metabolism in this process, we examined the interactions between glucose and PRL on glucose metabolism, insulin secretion, and glucokinase expression in insulin 1 (INS-1) cells and rat islets. Although the PRL-induced changes were more pronounced after culture at higher glucose concentrations, an increase in glucose metabolism, insulin secretion, and glucokinase expression occurred even in the absence of glucose. The presence of comparable levels of insulin secretion at similar rates of glucose metabolism from both control and PRL-treated INS-1 cells suggests the PRL-induced increase in glucose metabolism is responsible for the increase in insulin secretion. Similarly, increases in other known PRL responsive genes (e.g. the PRL receptor, glucose transporter-2, and insulin) were also detected after culture without glucose. We show that the upstream glucokinase promoter contains multiple STAT5 binding sequences with increased binding in response to PRL. Corresponding increases in glucokinase mRNA and protein synthesis were also detected. This suggests the PRL-induced increase in glucokinase mRNA and its translation are sufficient to account for the elevated glucokinase activity in β-cells with lactogens. Importantly, the increase in islet glucokinase observed with PRL is in line with that observed in islets during pregnancy.

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.

In vitro lymphocyte recognition of islet cells following in vivo priming with allogeneic murine pancreatic islets

1984 ◽  
Vol 105 (1) ◽  
pp. 87-92 ◽  
Author(s):  
Joanne Scott ◽  
Peter G. MacKay ◽  
Åke Lernmark
Keyword(s):  
Lymph Node ◽  
Pancreatic Islets ◽  
Islet Cell ◽  
Islet Cells ◽  
Culture Conditions ◽  
Pancreatic Tissue ◽  
Insulin Dependent ◽  
Lymph Node Cells

Abstract. Lymphocytes from patients with insulin-dependent diabetes have been shown to be sensitized to pancreatic tissue antigens. Mice immunized with homologous pancreatic islets have been found to develop glucose intolerance and insulitis. Since lymphocytes may be involved in diabetogenesis, we wished to determine if lymph node cells from islet-immunized mice can recognize and respond to islet cells in vitro. A.TL female mice were immunized with an emulsion of BALB/c islet homogenate and complete Freund's adjuvant (CFA); sham-treated A.TL mice were injected with adjuvant and water. Mice were sacrificed 7–8 days later and the draining lymph nodes were removed. The lymph node cells were co-cultured with freshly prepared irradiated BALB/c islet cell, which served as stimulator cells. The co-cultures were incubated for 24–26 h at 37°C, followed by a 16 h [3H]thymidine (TdR) pulse. A significant proliferation of lymph node cells from islet-primed mice was induced during the in vitro stimulation with irradiated islet cells when compared with lymph node cells from sham-treated mice (P < 0.001). The response may be islet-cell-specific, since irradiated lymph node cells from BALB/c mice failed to proliferative response under the same culture conditions (P > 0.80).

scholarly journals Increased Susceptibility to Streptozotocin-Induced β-Cell Apoptosis and Delayed Autoimmune Diabetes in Alkylpurine- DNA-N-Glycosylase-Deficient Mice

2001 ◽  
Vol 21 (16) ◽  
pp. 5605-5613 ◽  
Author(s):  
John W. Cardinal ◽  
Geoffrey P. Margison ◽  
Kurt J. Mynett ◽  
Allen P. Yates ◽  
Donald P. Cameron ◽  
...  
Keyword(s):  
Islet Cells ◽  
Excision Repair ◽  
Autoimmune Diabetes ◽  
Atp Depletion ◽  
Cell Necrosis ◽  
Β Cells ◽  
Β Cell ◽  
Autoimmune Reaction ◽  
Strand Breaks

ABSTRACT Type 1 diabetes is thought to occur as a result of the loss of insulin-producing pancreatic β cells by an environmentally triggered autoimmune reaction. In rodent models of diabetes, streptozotocin (STZ), a genotoxic methylating agent that is targeted to the β cells, is used to trigger the initial cell death. High single doses of STZ cause extensive β-cell necrosis, while multiple low doses induce limited apoptosis, which elicits an autoimmune reaction that eliminates the remaining cells. We now show that in mice lacking the DNA repair enzyme alkylpurine-DNA-N-glycosylase (APNG), β-cell necrosis was markedly attenuated after a single dose of STZ. This is most probably due to the reduction in the frequency of base excision repair-induced strand breaks and the consequent activation of poly(ADP-ribose) polymerase (PARP), which results in catastrophic ATP depletion and cell necrosis. Indeed, PARP activity was not induced in APNG−/− islet cells following treatment with STZ in vitro. However, 48 h after STZ treatment, there was a peak of apoptosis in the β cells of APNG−/− mice. Apoptosis was not observed in PARP-inhibited APNG+/+ mice, suggesting that apoptotic pathways are activated in the absence of significant numbers of DNA strand breaks. Interestingly, STZ-treated APNG−/− mice succumbed to diabetes 8 months after treatment, in contrast to previous work with PARP inhibitors, where a high incidence of β-cell tumors was observed. In the multiple-low-dose model, STZ induced diabetes in both APNG−/− and APNG+/+ mice; however, the initial peak of apoptosis was 2.5-fold greater in the APNG−/− mice. We conclude that APNG substrates are diabetogenic but by different mechanisms according to the status of APNG activity.

scholarly journals Exploration of NPTX2 in Islets of Langerhans

2020 ◽  
Vol 21 (2) ◽  
Author(s):  
Lindsay Elisha Wald
Keyword(s):  
Type 1 Diabetes ◽  
Insulin Secretion ◽  
Islet Cells ◽  
The Body ◽  
Immunofluorescent Staining ◽  
Β Cells ◽  
Healthy Human ◽  
Neuronal Pentraxin ◽  
The Brain

NPTX2 (neuronal pentraxin-2) is a synaptic protein found abundantly in only two locations in a healthy human body: the brain and the pancreas, specifically islet of Langerhans cells. NPTX2’s role in the brain has been a focus of study in the pathology of Parkinson’s disease, as it is upregulated in PD patients. Its primary functions in the brain are to establish excitatory synapses and to recruit alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-type glutamate receptors to said synapses. These AMPA receptors signal for the neurotransmitter, glutamate, that regulates insulin secretion. This is of pathological significance to the onset of type 1 diabetes. Type 1 diabetes is characterized by the depletion of islet β-cells in the pancreas, which are responsible for insulin secretion. Without a supply of insulin, fatal consequences will ensue. NPTX2’s function in the pancreas is unstudied and extremely relevant to unraveling the complex processes that the body undergoes with the onset of this autoimmune disease. In recent mRNA studies, NPTX2 mRNA was significantly downregulated in type 1 diabetes. To understand the underlying cause of this downregulation and its potential role in the destruction of islet β-cells, it is first necessary to localize NPTX2 in the islet cells of type 1 diabetic, auto-antibody positive, and control donors. Immunofluorescent staining indicates that NPTX2’s co-expression in 

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 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 Perilipin2 down-regulation in β cells impairs insulin secretion under nutritional stress and damages mitochondria

2020 ◽  
Author(s):  
Akansha Mishra ◽  
Siming Liu ◽  
Joseph Promes ◽  
Mikako Harata ◽  
William Sivitz ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Cell Function ◽  
Islet Cells ◽  
Cell Metabolism ◽  
Nutritional Stress ◽  
Β Cells ◽  
Β Cell ◽  
Down Regulation

Perilipin 2 (PLIN2) is the lipid droplet (LD) protein in β cells that increases under nutritional stress. Down-regulation of PLIN2 is often sufficient to reduce LD accumulation. To determine whether PLIN2 positively or negatively affects β cell function under nutritional stress, PLIN2 was down-regulated in mouse β cells, INS1 cells, and human islet cells. β cell specific deletion of PLIN2 in mice on a high fat diet reduced glucose-stimulated insulin secretion (GSIS) in vivo and in vitro. Down-regulation of PLIN2 in INS1 cells blunted GSIS after 24 h incubation with 0.2 mM palmitic acids. Down-regulation of PLIN2 in human pseudoislets cultured at 5.6 mM glucose impaired both phases of GSIS, indicating that PLIN2 is critical for GSIS. Down-regulation of PLIN2 decreased specific OXPHOS proteins in all three models and reduced oxygen consumption rates in INS1 cells and mouse islets. Moreover, we found that PLIN2 deficient INS1 cells increased the distribution of a fluorescent oleic acid analog to mitochondria and showed signs of mitochondrial stress as indicated by susceptibility to fragmentation and alterations of acyl-carnitines and glucose metabolites. Collectively, PLIN2 in β cells have an important role in preserving insulin secretion, β cell metabolism and mitochondrial function under nutritional stress.

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