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Sample records for pancreatic islet cells

  1. Pancreatic Islet Cell Transplantation

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    Warnock, Garth L.; Rajotte, Ray V.

    1992-01-01

    Transplantation of insulin-producing tissue offers a physiologic approach to restoration of glycemic control. Whereas transplantation of vascularized pancreatic grafts has recently achieved encouraging results, pancreatic islet cell transplantation holds the promise of low morbidity and reduced requirements for agressive immunosuppression for recipients. Islet cell transplantation was recently demonstrated to induce euglycemia with insulin independence. Imagesp1656-a PMID:21221366

  2. Pancreatic islet cell tumor

    Science.gov (United States)

    ... cell tumors; Islet of Langerhans tumor; Neuroendocrine tumors; Peptic ulcer - islet cell tumor; Hypoglycemia - islet cell tumor ... stomach acid. Symptoms may include: Abdominal pain Diarrhea ... and small bowel Vomiting blood (occasionally) Glucagonomas make ...

  3. Pancreatic Islet Cell Transplantation: A new era in transplantation

    OpenAIRE

    Warnock, Garth L.; Rajotte, Ray V.

    1992-01-01

    Transplantation of insulin-producing tissue offers a physiologic approach to restoration of glycemic control. Whereas transplantation of vascularized pancreatic grafts has recently achieved encouraging results, pancreatic islet cell transplantation holds the promise of low morbidity and reduced requirements for agressive immunosuppression for recipients. Islet cell transplantation was recently demonstrated to induce euglycemia with insulin independence.

  4. Zinc as a paracrine effector in pancreatic islet cell death.

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    Kim, B J; Kim, Y H; Kim, S; Kim, J W; Koh, J Y; Oh, S H; Lee, M K; Kim, K W; Lee, M S

    2000-03-01

    Because of a huge amount of Zn2+ in secretory granules of pancreatic islet beta-cells, Zn2+ released in certain conditions might affect the function or survival of islet cells. We studied potential paracrine effects of endogenous Zn2+ on beta-cell death. Zn2+ induced insulinoma/islet cell death in a dose-dependent manner. Chelation of released endogenous Zn2+ by CaEDTA significantly decreased streptozotocin (STZ)-induced islet cell death in an in vitro culture system simulating in vivo circumstances but not in the conventional culture system. Zn2+ chelation in vivo by continuous CaEDTA infusion significantly decreased the incidence of diabetes after STZ administration. N-(6-methoxy-quinolyl)-para-toluene-sulfonamide staining revealed that Zn2+ was densely deposited in degenerating islet cells 24 h after STZ treatment, which was decreased by CaEDTA infusion. We show here that Zn2+ is not a passive element for insulin storage but an active participant in islet cell death in certain conditions, which in time might contribute to the development of diabetes in aged people.

  5. Protein-Mediated Interactions of Pancreatic Islet Cells

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    Paolo Meda

    2013-01-01

    Full Text Available The islets of Langerhans collectively form the endocrine pancreas, the organ that is soley responsible for insulin secretion in mammals, and which plays a prominent role in the control of circulating glucose and metabolism. Normal function of these islets implies the coordination of different types of endocrine cells, noticeably of the beta cells which produce insulin. Given that an appropriate secretion of this hormone is vital to the organism, a number of mechanisms have been selected during evolution, which now converge to coordinate beta cell functions. Among these, several mechanisms depend on different families of integral membrane proteins, which ensure direct (cadherins, N-CAM, occludin, and claudins and paracrine communications (pannexins between beta cells, and between these cells and the other islet cell types. Also, other proteins (integrins provide communication of the different islet cell types with the materials that form the islet basal laminae and extracellular matrix. Here, we review what is known about these proteins and their signaling in pancreatic β-cells, with particular emphasis on the signaling provided by Cx36, given that this is the integral membrane protein involved in cell-to-cell communication, which has so far been mostly investigated for effects on beta cell functions.

  6. Clinical pancreatic islet transplantation.

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    Shapiro, A M James; Pokrywczynska, Marta; Ricordi, Camillo

    2017-05-01

    Clinical pancreatic islet transplantation can be considered one of the safest and least invasive transplant procedures. Remarkable progress has occurred in both the technical aspects of islet cell processing and the outcomes of clinical islet transplantation. With >1,500 patients treated since 2000, this therapeutic strategy has moved from a curiosity to a realistic treatment option for selected patients with type 1 diabetes mellitus (that is, those with hypoglycaemia unawareness, severe hypoglycaemic episodes and glycaemic lability). This Review outlines the techniques required for human islet isolation, in vitro culture before the transplant and clinical islet transplantation, and discusses indications, optimization of recipient immunosuppression and management of adjunctive immunomodulatory and anti-inflammatory strategies. The potential risks, long-term outcomes and advances in treatment after the transplant are also discussed to further move this treatment towards becoming a more widely available option for patients with type 1 diabetes mellitus and eventually a potential cure.

  7. [Xenogeneic cell therapeutics: Treatment of type 1 diabetes using porcine pancreatic islets and islet cells].

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    Godehardt, Antonia W; Schilling-Leiß, Dagmar; Sanzenbacher, Ralf; Tönjes, Ralf R

    2015-11-01

    In view of the existing shortage of human donor organs and tissues, xenogeneic cell therapeutics (xCT) offer an alternative for adequate treatment. In particular, porcine pancreatic islets and islet cells have already entered the field of experimental therapy for type-1 diabetes mellitus (T1DM) patients. Thereby, xCT depict challenging products with a glance on medical, ethical, and regulatory questions. With cross-species transplantation (xenotransplantation), the risk of immunological graft rejection as well as the risk of infectious transmission of microbial and viral pathogens must be considered. This includes the bidirectional transmission of microorganisms from graft to host as well as from host to graft. Crossing the border of species requires a critical risk-benefit evaluation as well as a thorough longtime surveillance of transplant recipients after treatment. The international legal and regulatory requirements for xCT are inter alia based on the World Health Organization criteria summarized in the Changsha Communiqué (2008). In the European Union, they were reflected by the European Medicines Agency (EMA) Guideline on Xenogeneic Cell-based Medicinal Products following the implementation of the Regulation on Advanced Therapies (ATMP). On the basis of this regulation, the first non-clinical and clinical experiences were obtained for porcine islets. The results suggest that supportive treatment of T1DM risk patients with xCT may be an alternative to established allogeneic organ transplantation in the future.

  8. Diffusion weighted MR imaging of pancreatic islet cell tumors

    International Nuclear Information System (INIS)

    Bakir, Baris; Salmaslioglu, Artur; Poyanli, Arzu; Rozanes, Izzet; Acunas, Bulent

    2010-01-01

    Purpose: The aim of our study is to demonstrate the feasibility of body diffusion weighted (DW) MR imaging in the evaluation of pancreatic islet cell tumors (ICTs) and to define apparent diffusion coefficient (ADC) values for these tumors. Materials and methods: 12 normal volunteers and 12 patients with histopathologically proven pancreatic ICT by surgery were included in the study. DW MR images were obtained by a body-phased array coil using a multisection single-shot echo planar sequence on the axial plane without breath holding. In addition, the routine abdominal imaging protocol for pancreas was applied in the patient group. We measured the ADC value within the normal pancreas in control group, pancreatic ICT, and surrounding pancreas parenchyma. Mann-Whitney U-test has been used to compare ADC values between tumoral tissues and normal pancreatic tissues of the volunteers. Wilcoxon Signed Ranks Test was preferred to compare ADC values between tumoral tissues and surrounding pancreatic parenchyma of the patients. Results: In 11 patients out of 12, conventional MR sequences were able to demonstrate ICTs successfully. In 1 patient an indistinct suspicious lesion was noted at the pancreatic tail. DW sequence was able to demonstrate the lesions in all of the 12 patients. On the DW images, all ICTs demonstrated high signal intensity relative to the surrounding pancreatic parenchyma. The mean and standard deviations of the ADC values (x10 -3 mm 2 /s) were as follows: ICT (n = 12), 1.51 ± 0.35 (0.91-2.11), surrounding parenchyma (n = 11) 0.76 ± 0.15 (0.51-1.01) and normal pancreas in normal volunteers (n = 12), 0.80 ± 0.06 (0.72-0.90). ADC values of the ICT were significantly higher compared with those of surrounding parenchyma (p < 0.01) and normal pancreas (p < 0.001). Conclusion: DW MR imaging does not appear to provide significant contribution to routine MR imaging protocol in the evaluation of pancreatic islet cell tumors. But it can be added to MR imaging

  9. Pancreatic islet transplantation

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    Corrêa-Giannella Maria

    2009-09-01

    Full Text Available Abstract Background No formulation of exogenous insulin available to date has yet been able to mimic the physiological nictemeral rhythms of this hormone, and despite all engineering advancements, the theoretical proposal of developing a mechanical replacement for pancreatic β cell still has not been reached. Thus, the replacement of β cells through pancreas and pancreatic islet transplantation are the only concrete alternatives for re-establishing the endogenous insulin secretion in type 1 diabetic patients. Since only 1 to 1.5% of the pancreatic mass corresponds to endocrine tissue, pancreatic islets transplantation arises as a natural alternative. Data from the International Islet Transplant Registry (ITR from 1983 to December 2000 document a total of 493 transplants performed around the world, with progressively worse rates of post-transplant insulin independence. In 2000, the "Edmonton Protocol" introduced several modifications to the transplantation procedure, such as the use of a steroid-free immunosuppression regimen and transplantation of a mean islet mass of 11,000 islet equivalents per kilogram, which significantly improved 1-year outcomes. Although the results of a 5-year follow-up in 65 patients demonstrated improvement in glycemic instability in a significant portion of them, only 7.5% of the patients have reached insulin independence, indicating the need of further advances in the preservation of the function of transplanted islet. In addition to the scarcity of organs available for transplantation, islets transplantation still faces major challenges, specially those related to cell loss during the process of islet isolation and the losses related to the graft site, apoptosis, allorejection, autoimmunity, and immunosuppression. The main strategies to optimize islet transplantation aim at improving all these aspects. Conclusion Human islet transplantation should be regarded as an intervention that can decrease the frequency of

  10. Identification of transplanted pancreatic islet cells by radioactive Dithizone-[131I]-Histamine conjugate. Preliminary report

    International Nuclear Information System (INIS)

    Garnuszek, P.; Licinska, I.; Mazurek, A.P.; Mrozek, A.; Wardawa, A.; Fiedor, P.S.

    2000-01-01

    Background: The unique mechanism of dithizone action in the interior of the viable pancreatic islet suggests the possible development of a specific radiopharmaceutical that may have a potential clinical application in the diagnosis of the pancreatic organ allografts or islets rejection. The radiodiagnostic properties of the newly developed radioactive analogue of dithizone, i.e. Dithizone-[131I]-Histamine conjugate have been evaluated in the present study. METHODS: The four islet cells transplantation models were chosen for this purpose. The most important feature of the Dithizone-[131I]-Histamine conjugate is its possessed ability of zinc chelation. As was presented in the recent study, the conjugate stains pink-reddish the isolated pancreatic islets in vitro. Among the studied transplantation models, only the islets grafting under testis capsule enabled determination of the pancreatic islets in rats by radioactive Dithizone-[131I]-Histamine conjugate. The level of the radioactivity in the recipient testis (right) was almost two times higher compared to the controls (0.24 v. 0.13% ID/g, respectively). CONCLUSIONS: These preliminary data demonstrate the ability of the developed radioactive analogue of dithizone for in vivo identification of transplanted pancreatic islets, and suggests a potential clinical application of the radiodithizone in the diagnosis of the pancreatic islet rejection. (author)

  11. Adipose stem cells from chronic pancreatitis patients improve mouse and human islet survival and function.

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    Song, Lili; Sun, Zhen; Kim, Do-Sung; Gou, Wenyu; Strange, Charlie; Dong, Huansheng; Cui, Wanxing; Gilkeson, Gary; Morgan, Katherine A; Adams, David B; Wang, Hongjun

    2017-08-30

    Chronic pancreatitis has surgical options including total pancreatectomy to control pain. To avoid surgical diabetes, the explanted pancreas can have islets harvested and transplanted. Immediately following total pancreatectomy with islet autotransplantation (TP-IAT), many islet cells die due to isolation and transplantation stresses. The percentage of patients remaining insulin free after TP-IAT is therefore low. We determined whether cotransplantation of adipose-derived mesenchymal stem cells (ASCs) from chronic pancreatitis patients (CP-ASCs) would protect islets after transplantation. In a marginal mass islet transplantation model, islets from C57BL/6 mice were cotransplanted with CP-ASCs into syngeneic streptozotocin-treated diabetic mice. Treatment response was defined by the percentage of recipients reaching normoglycemia, and by the area under the curve for glucose and c-peptide in a glucose tolerance test. Macrophage infiltration, β-cell apoptosis, and islet graft vasculature were measured in transplanted islet grafts by immunohistochemistry. mRNA expression profiling of 84 apoptosis-related genes in islet grafts transplanted alone or with CP-ASCs was measured by the RT 2 Profiler™ Apoptosis PCR Array. The impact of insulin-like growth factor-1 (IGF-1) on islet apoptosis was determined in islets stimulated with cytokines (IL-1β and IFN-γ) in the presence and absence of CP-ASC conditioned medium. CP-ASC-treated mice were more often normoglycemic compared to mice receiving islets alone. ASC cotransplantation reduced macrophage infiltration, β-cell death, suppressed expression of TNF-α and Bcl-2 modifying factor (BMF), and upregulated expressions of IGF-1 and TNF Receptor Superfamily Member 11b (TNFRSF11B) in islet grafts. Islets cultured in conditioned medium from CP-ASCs showed reduced cell death. This protective effect was diminished when IGF-1 was blocked in the conditioned medium by the anti-IGF-1 antibody. Cotransplantation of islets with ASCs

  12. Redifferentiation of insulin-secreting cells after in vitro expansion of adult human pancreatic islet tissue

    International Nuclear Information System (INIS)

    Lechner, Andreas; Nolan, Anna L.; Blacken, Robyn A.; Habener, Joel F.

    2005-01-01

    Cellular replacement therapy holds promise for the treatment of diabetes mellitus but donor tissue is severely limited. Therefore, we investigated whether insulin-secreting cells could be differentiated in vitro from a monolayer of cells expanded from human donor pancreatic islets. We describe a three-step culture protocol that allows for the efficient generation of insulin-producing cell clusters from in vitro expanded, hormone-negative cells. These clusters express insulin at levels of up to 34% that of average freshly isolated human islets and secrete C-peptide upon membrane depolarization. They also contain cells expressing the other major islet hormones (glucagon, somatostatin, and pancreatic polypeptide). The source of the newly differentiated endocrine cells could either be indigenous stem/progenitor cells or the proliferation-associated dedifferentiation and subsequent redifferentiation of mature endocrine cells. The in vitro generated cell clusters may be efficacious in providing islet-like tissue for transplantation into diabetic recipients

  13. FEATURES OF ISLET-LIKE CLUSTERS GENERATION IN PANCREATIC DUCTAL CELL MOLOLAYER CULTURING

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    L. A. Kirsanova

    2012-01-01

    Full Text Available Newborn rabbit pancreatic cell monolayer was obtained as we described earlier.The cultivated epithelial cells were shown by immunofluorescence to express special ductal marker CK19 and were insulin-and glucagon- negative for 10–15 days. A few fusiforms of nestin-positive cells were found in monolayer. Over 2 weeks in serum-free medium the plaques of epithelial cells became crowded and formed 3-dimentional structures – islet- like clusters. Islet-like clusters contain some insulin- and glucagon-positive cells recognized by immunohysto- chemistry staining. Pancreatic endocrine cell generation in 3-dimentional structures is discussed. 

  14. Transplantation of bone marrow derived cells promotes pancreatic islet repair in diabetic mice

    International Nuclear Information System (INIS)

    Gao Xiaodong; Song Lujun; Shen Kuntang; Wang Hongshan; Niu Weixin; Qin Xinyu

    2008-01-01

    The transplantation of bone marrow (BM) derived cells to initiate pancreatic regeneration is an attractive but as-yet unrealized strategy. Presently, BM derived cells from green fluorescent protein transgenic mice were transplanted into diabetic mice. Repair of diabetic islets was evidenced by reduction of hyperglycemia, increase in number of islets, and altered pancreatic histology. Cells in the pancreata of recipient mice co-expressed BrdU and insulin. Double staining revealed β cells were in the process of proliferation. BrdU + insulin - PDX-1 + cells, Ngn3 + cells and insulin + glucagon + cells, which showed stem cells, were also found during β-cell regeneration. The majority of transplanted cells were mobilized to the islet and ductal regions. In recipient pancreas, transplanted cells simultaneously expressed CD34 but did not express insulin, PDX-1, Ngn3, Nkx2.2, Nkx6.1, Pax4, Pax6, and CD45. It is concluded that BM derived cells especially CD34 + cells can promote repair of pancreatic islets. Moreover, both proliferation of β cells and differentiation of pancreatic stem cells contribute to the regeneration of β cells

  15. Immunohistochemical localization of glucagon and pancreatic polypeptide on rat endocrine pancreas: coexistence in rat islet cells

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    YH Huang

    2009-08-01

    Full Text Available We used immunofluorescence double staining method to investigate the cellular localization of glucagon and pancreatic polypeptide (PP in rat pancreatic islets. The results showed that both A-cells (glucagon-secreting cells and PP-cells (PPsecreting cells were located in the periphery of the islets. However, A-cells and PP-cells had a different regional distribution. Most of A-cells were located in the splenic lobe but a few of them were in the duodenal lobe of the pancreas. In contrast, the majority of PP-cells were found in the duodenal lobe and a few of them were in the splenic lobe of the pancreas. Furthermore, we found that 67.74% A-cells had PP immunoreactivity, 70.92% PP-cells contained glucagon immunoreactivity with immunofluorescence double staining. Our data support the concept of a common precursor stem cell for pancreatic hormone-producing cells.

  16. Loss of end-differentiated β-cell phenotype following pancreatic islet transplantation.

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    Anderson, S J; White, M G; Armour, S L; Maheshwari, R; Tiniakos, D; Muller, Y D; Berishvili, E; Berney, T; Shaw, J A M

    2018-03-01

    Replacement of pancreatic β-cells through deceased donor islet transplantation is a proven therapy for preventing recurrent life-threatening hypoglycemia in type 1 diabetes. Although near-normal glucose levels and insulin independence can be maintained for many years following successful islet transplantation, restoration of normal functional β-cell mass has remained elusive. It has recently been proposed that dedifferentiation/plasticity towards other endocrine phenotypes may play an important role in stress-induced β-cell dysfunction in type 2 diabetes. Here we report loss of end-differentiated β-cell phenotype in 2 intraportal islet allotransplant recipients. Despite excellent graft function and sustained insulin independence, all examined insulin-positive cells had lost expression of the end-differentiation marker, urocortin-3, or appeared to co-express the α-cell marker, glucagon. In contrast, no insulin + /urocortin-3 - cells were seen in nondiabetic deceased donor control pancreatic islets. Loss of end-differentiated phenotype may facilitate β-cell survival during the stresses associated with islet isolation and culture, in addition to sustained hypoxia following engraftment. As further refinements in islet isolation and culture are made in parallel with exploration of alternative β-cell sources, graft sites, and ultimately fully vascularized bioengineered insulin-secreting microtissues, differentiation status immunostaining provides a novel tool to assess whether fully mature β-cell phenotype has been maintained. © 2017 The American Society of Transplantation and the American Society of Transplant Surgeons.

  17. Metastatic Insulinoma Following Resection of Nonsecreting Pancreatic Islet Cell Tumor

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    Anoopa A. Koshy MD

    2013-01-01

    Full Text Available A 56-year-old woman presented to our clinic for recurrent hypoglycemia after undergoing resection of an incidentally discovered nonfunctional pancreatic endocrine tumor 6 years ago. She underwent a distal pancreatectomy and splenectomy, after which she developed diabetes and was placed on an insulin pump. Pathology showed a pancreatic endocrine neoplasm with negative islet hormone immunostains. Two years later, computed tomography scan of the abdomen showed multiple liver lesions. Biopsy of a liver lesion showed a well-differentiated neuroendocrine neoplasm, consistent with pancreatic origin. Six years later, she presented to clinic with 1.5 years of recurrent hypoglycemia. Laboratory results showed elevated proinsulin, insulin levels, and c-peptide levels during a hypoglycemic episode. Computed tomography scan of the abdomen redemonstrated multiple liver lesions. Repeated transarterial catheter chemoembolization and microwave thermal ablation controlled hypoglycemia. The unusual features of interest of this case include the transformation of nonfunctioning pancreatic endocrine tumor to a metastatic insulinoma and the occurrence of atrial flutter after octreotide for treatment.

  18. Islet Cells Serve as Cells of Origin of Pancreatic Gastrin-Positive Endocrine Tumors.

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    Bonnavion, Rémy; Teinturier, Romain; Jaafar, Rami; Ripoche, Doriane; Leteurtre, Emmanuelle; Chen, Yuan-Jia; Rehfeld, Jens F; Lepinasse, Florian; Hervieu, Valérie; Pattou, François; Vantyghem, Marie-Christine; Scoazec, Jean-Yves; Bertolino, Philippe; Zhang, Chang Xian

    2015-10-01

    The cells of origin of pancreatic gastrinomas remain an enigma, since no gastrin-expressing cells are found in the normal adult pancreas. It was proposed that the cellular origin of pancreatic gastrinomas may come from either the pancreatic cells themselves or gastrin-expressing cells which have migrated from the duodenum. In the current study, we further characterized previously described transient pancreatic gastrin-expressing cells using cell lineage tracing in a pan-pancreatic progenitor and a pancreatic endocrine progenitor model. We provide evidence showing that pancreatic gastrin-expressing cells, found from embryonic day 12.5 until postnatal day 7, are derived from pancreatic Ptf1a(+) and neurogenin 3-expressing (Ngn3(+)) progenitors. Importantly, the majority of them coexpress glucagon, with 4% coexpressing insulin, indicating that they are a temporary subpopulation of both alpha and beta cells. Interestingly, Men1 disruption in both Ngn3 progenitors and beta and alpha cells resulted in the development of pancreatic gastrin-expressing tumors, suggesting that the latter developed from islet cells. Finally, we detected gastrin expression using three human cohorts with pancreatic endocrine tumors (pNETs) that have not been diagnosed as gastrinomas (in 9/34 pNETs from 6/14 patients with multiple endocrine neoplasia type 1, in 5/35 sporadic nonfunctioning pNETs, and in 2/20 sporadic insulinomas), consistent with observations made in mouse models. Our work provides insight into the histogenesis of pancreatic gastrin-expressing tumors. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  19. B cell depletion reduces T cell activation in pancreatic islets in a murine autoimmune diabetes model.

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    Da Rosa, Larissa C; Boldison, Joanne; De Leenheer, Evy; Davies, Joanne; Wen, Li; Wong, F Susan

    2018-06-01

    Type 1 diabetes is a T cell-mediated autoimmune disease characterised by the destruction of beta cells in the islets of Langerhans, resulting in deficient insulin production. B cell depletion therapy has proved successful in preventing diabetes and restoring euglycaemia in animal models of diabetes, as well as in preserving beta cell function in clinical trials in the short term. We aimed to report a full characterisation of B cell kinetics post B cell depletion, with a focus on pancreatic islets. Transgenic NOD mice with a human CD20 transgene expressed on B cells were injected with an anti-CD20 depleting antibody. B cells were analysed using multivariable flow cytometry. There was a 10 week delay in the onset of diabetes when comparing control and experimental groups, although the final difference in the diabetes incidence, following prolonged observation, was not statistically significant (p = 0.07). The co-stimulatory molecules CD80 and CD86 were reduced on stimulation of B cells during B cell depletion and repopulation. IL-10-producing regulatory B cells were not induced in repopulated B cells in the periphery, post anti-CD20 depletion. However, the early depletion of B cells had a marked effect on T cells in the local islet infiltrate. We demonstrated a lack of T cell activation, specifically with reduced CD44 expression and effector function, including IFN-γ production from both CD4 + and CD8 + T cells. These CD8 + T cells remained altered in the pancreatic islets long after B cell depletion and repopulation. Our findings suggest that B cell depletion can have an impact on T cell regulation, inducing a durable effect that is present long after repopulation. We suggest that this local effect of reducing autoimmune T cell activity contributes to delay in the onset of autoimmune diabetes.

  20. A hybrid of cells and pancreatic islets toward a new bioartificial pancreas

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    Yuji Teramura

    2016-03-01

    Full Text Available Cell surface engineering using single-stranded DNA–poly(ethylene glycol-conjugated phospholipid (ssDNA–PEG-lipid is useful for inducing cell–cell attachment two and three dimensionally. In this review, we summarize our recent techniques for cell surface engineering and their applications to islet transplantation. Because any DNA sequence can be immobilized onto the cell surface by hydrophobic interactions between ssDNA–PEG-lipid and the cellular membrane without impairing cell function, a cell–cell hybrid can be formed through the DNA hybridization. With this technique, it would be possible to create three-dimensional hybrid structures of pancreatic islets coated with various accessory cells, such as patients’ own cells, mesenchymal and adipose-derived stem cells, endothelial progenitor cells, neural crest stem cells or regulatory T cells, which might significantly improve the outcome of islet transplantation in diabetic patients.

  1. Pancreatic β-Cell-Derived IP-10/CXCL10 Isletokine Mediates Early Loss of Graft Function in Islet Cell Transplantation.

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    Yoshimatsu, Gumpei; Kunnathodi, Faisal; Saravanan, Prathab Balaji; Shahbazov, Rauf; Chang, Charles; Darden, Carly M; Zurawski, Sandra; Boyuk, Gulbahar; Kanak, Mazhar A; Levy, Marlon F; Naziruddin, Bashoo; Lawrence, Michael C

    2017-11-01

    Pancreatic islets produce and secrete cytokines and chemokines in response to inflammatory and metabolic stress. The physiological role of these "isletokines" in health and disease is largely unknown. We observed that islets release multiple inflammatory mediators in patients undergoing islet transplants within hours of infusion. The proinflammatory cytokine interferon-γ-induced protein 10 (IP-10/CXCL10) was among the highest released, and high levels correlated with poor islet transplant outcomes. Transgenic mouse studies confirmed that donor islet-specific expression of IP-10 contributed to islet inflammation and loss of β-cell function in islet grafts. The effects of islet-derived IP-10 could be blocked by treatment of donor islets and recipient mice with anti-IP-10 neutralizing monoclonal antibody. In vitro studies showed induction of the IP-10 gene was mediated by calcineurin-dependent NFAT signaling in pancreatic β-cells in response to oxidative or inflammatory stress. Sustained association of NFAT and p300 histone acetyltransferase with the IP-10 gene required p38 and c-Jun N-terminal kinase mitogen-activated protein kinase (MAPK) activity, which differentially regulated IP-10 expression and subsequent protein release. Overall, these findings elucidate an NFAT-MAPK signaling paradigm for induction of isletokine expression in β-cells and reveal IP-10 as a primary therapeutic target to prevent β-cell-induced inflammatory loss of graft function after islet cell transplantation. © 2017 by the American Diabetes Association.

  2. Single Cell Dissection of Human Pancreatic Islet Dysfunction in Diabetes

    Science.gov (United States)

    2017-06-01

    of memory T cells , innate cells and the differentiation potential of naive T cells during ME/CFS; and 3) To determine the T cell and innate cell ...apoptosis and the innate immune response in human pancreatic β- cells . Diabetes 64: 3808–3817. Marselli L, Thorne J, Dahiya S, Sgroi DC, Sharma A, Bonner-Weir...interactive nature of CellView aids in cell doublet identification. In the PBMC data, ‘Subcluster-analysis’ reveals a mixture of lymphoid and myeloid

  3. Glucose activates prenyltransferases in pancreatic islet {beta}-cells

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    Goalstone, Marc [Department of Medicine, University of Colorado, VA Medical Center, Denver, CO 80220 (United States); Kamath, Vasudeva [Department of Pharmaceutical Sciences, Wayne State University, VA Medical Center, Detroit, MI 48201 (United States); Kowluru, Anjaneyulu, E-mail: akowluru@med.wayne.edu [Department of Pharmaceutical Sciences, Wayne State University, VA Medical Center, Detroit, MI 48201 (United States)

    2010-01-01

    A growing body of evidence implicates small G-proteins [e.g., Cdc42 and Rac1] in glucose-stimulated insulin secretion [GSIS] in the islet {beta}-cell. These signaling proteins undergo post-translational modifications [e.g., prenylation] at their C-terminal cysteine residue and appear to be essential for the transport and fusion of insulin-containing secretory granules with the plasma membrane and the exocytotic secretion of insulin. However, potential regulation of the prenylating enzymes by physiological insulin secretogues [e.g., glucose] has not been investigated thus far. Herein, we report immunological localization, sub-cellular distribution and regulation of farnesyltransferases [FTases] and geranylgeranyltransferase [GGTase] by glucose in insulin-secreting INS 832/13 {beta}-cells and normal rat islets. Our findings suggest that an insulinotropic concentration of glucose [20 mM] markedly stimulated the expression of the {alpha}-subunits of FTase/GGTase-1, but not the {beta}-subunits of FTase or GGTase-1 without significantly affecting the predominantly cytosolic distribution of these holoenzymes in INS 832/13 cells and rodent islets. Under these conditions, glucose significantly stimulated [2.5- to 4.0-fold over basal] the activities of both FTase and GGTase-1 in both cell types. Together, these findings provide the first evidence to suggest that GSIS involves activation of the endogenous islet prenyltransferases by glucose, culminating in the activation of their respective G-protein substrates, which is necessary for cytoskeletal rearrangement, vesicular transport, fusion and secretion of insulin.

  4. Glucose activates prenyltransferases in pancreatic islet β-cells

    International Nuclear Information System (INIS)

    Goalstone, Marc; Kamath, Vasudeva; Kowluru, Anjaneyulu

    2010-01-01

    A growing body of evidence implicates small G-proteins [e.g., Cdc42 and Rac1] in glucose-stimulated insulin secretion [GSIS] in the islet β-cell. These signaling proteins undergo post-translational modifications [e.g., prenylation] at their C-terminal cysteine residue and appear to be essential for the transport and fusion of insulin-containing secretory granules with the plasma membrane and the exocytotic secretion of insulin. However, potential regulation of the prenylating enzymes by physiological insulin secretogues [e.g., glucose] has not been investigated thus far. Herein, we report immunological localization, sub-cellular distribution and regulation of farnesyltransferases [FTases] and geranylgeranyltransferase [GGTase] by glucose in insulin-secreting INS 832/13 β-cells and normal rat islets. Our findings suggest that an insulinotropic concentration of glucose [20 mM] markedly stimulated the expression of the α-subunits of FTase/GGTase-1, but not the β-subunits of FTase or GGTase-1 without significantly affecting the predominantly cytosolic distribution of these holoenzymes in INS 832/13 cells and rodent islets. Under these conditions, glucose significantly stimulated [2.5- to 4.0-fold over basal] the activities of both FTase and GGTase-1 in both cell types. Together, these findings provide the first evidence to suggest that GSIS involves activation of the endogenous islet prenyltransferases by glucose, culminating in the activation of their respective G-protein substrates, which is necessary for cytoskeletal rearrangement, vesicular transport, fusion and secretion of insulin.

  5. Dynamics and Synchrony of Pancreatic beta-cells and Islets

    DEFF Research Database (Denmark)

    Pedersen, Morten Gram

    2006-01-01

    description of these processes and their interactions would provide important input in the search for a better treatment of the disease. The thesis describes several aspects of mathematical modeling of beta-cells relevant for the understanding of glucose stimulated insulin secretion. It consists...... and the synchronized behavior of many coupled beta-cells as well as to the synchrony of islets. Rather than developing new biophysical models, the thesis investigates existing models, their integration and simplifications, and analyzed the corresponding dynamics, in order to use these models for investigating...

  6. A role of pancreatic stellate cells in islet fibrosis and β-cell dysfunction in type 2 diabetes mellitus

    International Nuclear Information System (INIS)

    Lee, Esder; Ryu, Gyeong Ryul; Ko, Seung-Hyun; Ahn, Yu-Bae; Song, Ki-Ho

    2017-01-01

    Objectives: To investigate whether the activation of pancreatic stellate cells (PSCs) leads to pancreatic β-cell dysfunction in type 2 diabetes mellitus (T2DM). Methods: The pancreases of Otsuka Long-Evans Tokushima Fatty (OLETF) rats, an animal model of T2DM, and patient with T2DM were analyzed. And the in vitro and in vivo effects of pirfenidone, an antifibrotic agent, on PSC activation, islet fibrosis, and β-cells were studied. Results: The extent of islet fibrosis and the percentage of activated PSCs, positive for α-smooth muscle actin, in the islets were significantly greater in OLETF rats compared with non-diabetic rats. Also, the extent of islet fibrosis in patients with T2DM was slightly greater compared with age- and BMI-matched non-diabetic patients. In rat PSCs cultured with high glucose for 72 h, pirfenidone produced decreases in cell proliferation, release of collagen, and the expression of fibronectin and connective tissue growth factor. Treatment of OLETF rats with pirfenidone for 16 weeks decreased the activation of PSCs and the extent of islet fibrosis, but did not enhance glucose tolerance, pancreatic insulin content, or β-cell mass. Conclusions: Activated PSCs in islets might lead to islet fibrosis in T2DM. However, PSC activation itself might not contribute significantly to progressive β-cell failure in T2DM. - Highlights: • Islet fibrosis developed progressively in OLETF rats, a model of type 2 diabetes. • PSCs in the islets became activated in OLETF rats. • Islet fibrosis was increased in patients with type 2 diabetes. • Pirfenidone attenuated the activation of PSCs and islet fibrosis in OLETF rats. • Pirfenidonet had no effects on glucose tolerance or on β-cells in OLETF rats.

  7. Characterization of a pancreatic islet cell tumor in a polar bear (Ursus maritimus).

    Science.gov (United States)

    Fortin, Jessica S; Benoit-Biancamano, Marie-Odile

    2014-01-01

    Herein, we report a 25-year-old male polar bear suffering from a pancreatic islet cell tumor. The aim of this report is to present a case of this rare tumor in a captive polar bear. The implication of potential risk factors such as high carbohydrate diet or the presence of amyloid fibril deposits was assessed. Necropsy examination revealed several other changes, including nodules observed in the liver, spleen, pancreas, intestine, and thyroid glands that were submitted for histopathologic analysis. Interestingly, the multiple neoplastic nodules were unrelated and included a pancreatic islet cell tumor. Immunohistochemistry of the pancreas confirmed the presence of insulin and islet amyloid polypeptide (IAPP) within the pancreatic islet cells. The IAPP gene was extracted from the paraffin-embedded liver tissue and sequenced. IAPP cDNA from the polar bear exhibits some differences as compared to the sequence published for several other species. Different factors responsible for neoplasms in bears such as diet, infectious agents, and industrial chemical exposure are reviewed. This case report raised several issues that further studies may address by evaluating the prevalence of cancers in captive or wild animals. © 2014 Wiley Periodicals, Inc.

  8. In Vivo Imaging of Transplanted Pancreatic Islets

    Directory of Open Access Journals (Sweden)

    Donghee Kim

    2018-01-01

    Full Text Available The beta-cells in the islets of Langerhans in the pancreas secrete insulin and play an important role in glucose homeostasis. Diabetes, characterized by hyperglycemia, results from an absolute or a relative deficiency of the pancreatic beta-cell mass. Islet transplantation has been considered to be a useful therapeutic approach, but it is largely unsuccessful because most of the transplanted islets are lost in the early stage of transplantation. To evaluate the efficacy of intervention methods for the improvement of islet survival, monitoring of the functional islet mass is needed. Various techniques to image and track transplanted islets have been investigated to assess islets after transplantation. In this review, recent progresses in imaging methods to visualize islets are discussed.

  9. Dipeptidyl peptidase IV is sorted to the secretory granules in pancreatic islet A-cells

    DEFF Research Database (Denmark)

    Poulsen, Mona Dam; Hansen, Gert Helge; Dabelsteen, Erik

    1993-01-01

    Dipeptidyl peptidase IV (DP IV:EC 3.4.14.5) was localized in endocrine cells of pig pancreas by immunohistochemical and enzyme histochemical methods. Immunolight microscopy with both monoclonal and polyclonal antibodies demonstrated DP IV immunoreactivity in cells located in the peripheral part...... of the islets of Langerhans. The antigen is enzymatically active, as shown by enzyme histochemical analysis with a synthetic DP IV substrate. By immunoelectron microscopy (immunogold labeling), the labeling of DP IV in the islets was associated with the secretory granules of the A-cells, as identified by double...... labeling using a monoclonal glucagon antibody as the second primary antibody. These results show that DP IV is sorted to secretory granules in the pig pancreatic islet A-cells. Furthermore, this secretory granule enzyme, as opposed to intestinal brush border DP IV, is suggested to be a soluble protein...

  10. Profile of blood glucose and ultrastucture of beta cells pancreatic islet in alloxan compound induced rats

    Directory of Open Access Journals (Sweden)

    I Nyoman Suarsana

    2010-06-01

    Full Text Available Diabetes is marked by elevated levels of blood glucose, and progressive changes of the structure of pancreatic islet histopathology. The objective of this research was to analyse the glucose level and histophatological feature in pancreatic islet in alloxan compound induced rats. A total of ten male Spraque Dawley rats of 2 months old were used in this study. The rats were divided into two groups: (1 negative control group (K-, and (2 positif induced alloxan group (diabetic group =DM. The rats were induced by a single dose intraperitonial injection of alloxan compound 120 mg/kg of body weight. The treatment was conducted for 28 days. Blood glucose levels of rats were analysed at 0, 4, 7, 14, 21, and 28 days following treatment. At the end of the experiment, rats were sacrificed by cervical dislocation. Pancreas was collected for analysis of histopathological study by Immunohistochemical technique, and ultrastructural study using transmission electron microscope (TEM. The result showed that Langerhans islet of diabetic rat (rat of DM group showed a marked reduction of size, number of Langerhans islet of diabetic rat decrease, and characterized by hyperglycemic condition. By using TEM, beta cells of DM group showed the rupture of mitochondrial membrane, the lost of cisternal structure of inner membrane of mitocondria, reduction of insulin secretory granules, linkage between cells acinar with free Langerhans islet, and the caryopicnotic of nucleus.

  11. Ionic and secretory response of pancreatic islet cells to minoxidil sulfate

    International Nuclear Information System (INIS)

    Antoine, M.H.; Hermann, M.; Herchuelz, A.; Lebrun, P.

    1991-01-01

    Minoxidil sulfate is an antihypertensive agent belonging to the new class of vasodilators, the K+ channel openers. The present study was undertaken to characterize the effects of minoxidil sulfate on ionic and secretory events in rat pancreatic islets. The drug unexpectedly provoked a concentration-dependent decrease in 86Rb outflow. This inhibitory effect was reduced in a concentration-dependent manner by glucose and tolbutamide. Minoxidil sulfate did not affect 45Ca outflow from islets perfused in the presence of extracellular Ca++ and absence or presence of glucose. However, in islets exposed to a medium deprived of extracellular Ca++, the drug provoked a rise in 45Ca outflow. Whether in the absence or presence of extracellular Ca++, minoxidil sulfate increased the cytosolic free Ca++ concentration of islet cells. Lastly, minoxidil sulfate increased the release of insulin from glucose-stimulated pancreatic islets. These results suggest that minoxidil sulfate reduces the activity of the ATP-sensitive K+ channels and promotes an intracellular translocation of Ca++. The latter change might account for the effect of the drug on the insulin-releasing process. However, the secretory response to minoxidil sulfate could also be mediated, at least in part, by a modest Ca++ entry

  12. Organ culture studies for pancreatic islet transplantation

    International Nuclear Information System (INIS)

    Reemtsma, K.; Weber, C.J.; Pi-Sunyer, F.X.; Lerner, R.; Zimmerman, E.; Hardy, M.A.

    1979-01-01

    Data support the usefulness of tissue culture in isolation and preservation of islets prior to transplantation. Rodent islet viability in culture was demonstrated histologically and by functional analyses of hormone production. For reasons that remain to be defined, acinar cells disappeared rapidly in tissue culture, yielding an implant preparation relatively rich in islets and devoid of pancreatic exocrine elements. Isografts of cultured and noncultured islets were well tolerated intraperitoneally and intramuscularly; and prompt and lasting reversal of short- and long-standing experimental diabetes was observed regularly. In vitro studies of rodent islet viability after immunosuppressive treatment of donors or islet cultures showed insulin production comparable to that of control experiments, suggesting that immunologic modification of donors or islets might be feasible in eventual human islet allotransplantation

  13. Generation of glucose-responsive functional islets with a three-dimensional structure from mouse fetal pancreatic cells and iPS cells in vitro.

    Directory of Open Access Journals (Sweden)

    Hiroki Saito

    Full Text Available Islets of Langerhans are a pancreatic endocrine compartment consisting of insulin-producing β cells together with several other hormone-producing cells. While some insulin-producing cells or immature pancreatic cells have been generated in vitro from ES and iPS cells, islets with proper functions and a three-dimensional (3D structure have never been successfully produced. To test whether islets can be formed in vitro, we first examined the potential of mouse fetal pancreatic cells. We found that E16.5 pancreatic cells, just before forming islets, were able to develop cell aggregates consisting of β cells surrounded by glucagon-producing α cells, a structure similar to murine adult islets. Moreover, the transplantation of these cells improved blood glucose levels in hyperglycemic mice. These results indicate that functional islets are formed in vitro from fetal pancreatic cells at a specific developmental stage. By adopting these culture conditions to the differentiation of mouse iPS cells, we developed a two-step system to generate islets, i.e. immature pancreatic cells were first produced from iPS cells, and then transferred to culture conditions that allowed the formation of islets from fetal pancreatic cells. The islets exhibited distinct 3D structural features similar to adult pancreatic islets and secreted insulin in response to glucose concentrations. Transplantation of the islets improved blood glucose levels in hyperglycemic mice. In conclusion, the two-step culture system allows the generation of functional islets with a 3D structure from iPS cells.

  14. The role of interventional radiology and imaging in pancreatic islet cell transplantation

    International Nuclear Information System (INIS)

    Dixon, S.; Tapping, C.R.; Walker, J.N.; Bratby, M.; Anthony, S.; Boardman, P.; Phillips-Hughes, J.; Uberoi, R.

    2012-01-01

    Pancreatic islet cell transplantation (PICT) is a novel treatment for patients with insulin-dependent diabetes who have inadequate glycaemic control or hypoglycaemic unawareness, and who suffer from the microvascular/macrovascular complications of diabetes despite aggressive medical management. Islet transplantation primarily aims to improve the quality of life for type 1 diabetic patients by achieving insulin independence, preventing hypoglycaemic episodes, and reversing hypoglycaemic unawareness. The islet cells for transplantation are extracted and purified from the pancreas of brain-stem dead, heart-beating donors. They are infused into the recipient's portal vein, where they engraft into the liver to release insulin in order to restore euglycaemia. Initial strategies using surgical access to the portal vein have been superseded by percutaneous access using interventional radiology techniques, which are relatively straightforward to perform. It is important to be vigilant during the procedure in order to prevent major complications, such as haemorrhage, which can be potentially life-threatening. In this article we review the history of islet cell transplantation, present an illustrated review of our experience with islet cell transplantation by describing the role of imaging and interventional radiology, and discuss current research into imaging techniques for monitoring graft function.

  15. Chaotic electrical activity of living β-cells in the mouse pancreatic islet

    Science.gov (United States)

    Kanno, Takahiro; Miyano, Takaya; Tokuda, Isao; Galvanovskis, Juris; Wakui, Makoto

    2007-02-01

    To test for chaotic dynamics of the insulin producing β-cell and explore its biological role, we observed the action potentials with the perforated patch clamp technique, for isolated cells as well as for intact cells of the mouse pancreatic islet. The time series obtained were analyzed using nonlinear diagnostic algorithms associated with the surrogate method. The isolated cells exhibited short-term predictability and visible determinism, in the steady state response to 10 mM glucose, while the intact cells did not. In the latter case, determinism became visible after the application of a gap junction inhibitor. This tendency was enhanced by the stimulation with tolbutamide. Our observations suggest that, thanks to the integration of individual chaotic dynamics via gap junction coupling, the β-cells will lose memory of fluctuations occurring at any instant in their electrical activity more rapidly with time. This is likely to contribute to the functional stability of the islet against uncertain perturbations.

  16. [Effect of jiaotai pill on pancreatic fat accumulation and islet cell apoptosis in rats with type 2 diabetes].

    Science.gov (United States)

    Zou, Xin; Liu, De-Liang; Lu, Fu-Er; Dong, Hui; Xu, Li-Jun; Luo, Yun-Huan; Wang, Kai-Fu

    2014-06-01

    In this study, the rat type 2 diabetes mellitus (T2DM) model was established through tail vein injection with low dose of streptozotocin (STZ) and high fat diet for 8 weeks, and then treated with Jiaotai Pill. The oral glucose tolerance test (OGTT), fasting serum insulin (FINS), free fatty acid(FFA) levels and blood lipid were assayed. HOMA-IR was calculated. Pancreatic pathology was performed. And pancreatic triglyceride (TG) content was examined by the lipid extraction method. Pancreatic islet cell apoptosis were detected by terminal dexynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL). According to the results, the model group showed abnormal OGTT, increased FINS, HOMA-IR, FFA, lipid disorder, obvious fat accumulation and significantly increased TG content in pancreatic tissues, and enhanced pancreatic islet cell apoptosis. Compared with the model group, the Jiaotai Pill group displayed improved OGTT, reduced FINS, HOMA-IR, FFA, recovered lipid disorder, decreased fat accumulation and significantly declined TG content in pancreatic tissues, and lowered pancreatic islet cell apoptosis. In summary, Jiaotai pill could effectively treat type 2 diabetes in rats. Its mechanism may be related to the reduction in pancreatic fat accumulation and islet cell apoptosis.

  17. Entrapment of dispersed pancreatic islet cells in CultiSpher-S macroporous gelatin microcarriers: Preparation, in vitro characterization, and microencapsulation.

    Science.gov (United States)

    Del Guerra, S; Bracci, C; Nilsson, K; Belcourt, A; Kessler, L; Lupi, R; Marselli, L; De Vos, P; Marchetti, P

    2001-12-20

    Immunoprotection of pancreatic islets for successful allo- or xenotransplantation without chronic immunosuppression is an attractive, but still elusive, approach for curing type 1 diabetes. It was recently shown that, even in the absence of fibrotic overgrowth, other factors, mainly insufficient nutrition to the core of the islets, represent a major barrier for long-term survival of intraperitoneal microencapsulated islet grafts. The use of dispersed cells might contribute to solve this problem due to the conceivably easier nutritional support to the cells. In the present study, purified bovine islets, prepared by collagenase digestion and density gradient purification, and dispersed bovine islet cells, obtained by trypsin and DNAsi (viability > 90%), were entrapped into either 2% (w/v) sodium alginate (commonly used for encapsulation purposes) or (dispersed islet cells only) macroporous gelatin microcarriers (CulthiSpher-S, commonly used for the production of biologicals by animal cells). Insulin release studies in response to glucose were performed within 1 week and after 1 month from preparation of the varying systems and showed no capability of dispersed bovine islet cells within sodium alginate microcapsules to sense glucose concentration changes. On the contrary, bovine islet cells entrapped in CulthiSpher-S microcarriers showed maintained capacity of increasing insulin secretion upon enhanced glucose concentration challenge. In this case, insulin release was approximately 60% of that from intact bovine islets within sodium alginate microcapsules. MTT and hematoxylineosin staining of islet cell-containing microcarriers showed the presence of viable and metabolically active cells throughout the study period. This encouraging functional data prompted us to test whether the microcarriers could be immunoisolated for potential use in transplantation. The microcarriers were embedded within 3% sodium alginate, which was then covered with a poly-L-lysine layer and a

  18. The impact of IUGR on pancreatic islet development and β-cell function.

    Science.gov (United States)

    Boehmer, Brit H; Limesand, Sean W; Rozance, Paul J

    2017-11-01

    Placental insufficiency is a primary cause of intrauterine growth restriction (IUGR). IUGR increases the risk of developing type 2 diabetes mellitus (T2DM) throughout life, which indicates that insults from placental insufficiency impair β-cell development during the perinatal period because β-cells have a central role in the regulation of glucose tolerance. The severely IUGR fetal pancreas is characterized by smaller islets, less β-cells, and lower insulin secretion. Because of the important associations among impaired islet growth, β-cell dysfunction, impaired fetal growth, and the propensity for T2DM, significant progress has been made in understanding the pathophysiology of IUGR and programing events in the fetal endocrine pancreas. Animal models of IUGR replicate many of the observations in severe cases of human IUGR and allow us to refine our understanding of the pathophysiology of developmental and functional defects in islet from IUGR fetuses. Almost all models demonstrate a phenotype of progressive loss of β-cell mass and impaired β-cell function. This review will first provide evidence of impaired human islet development and β-cell function associated with IUGR and the impact on glucose homeostasis including the development of glucose intolerance and diabetes in adulthood. We then discuss evidence for the mechanisms regulating β-cell mass and insulin secretion in the IUGR fetus, including the role of hypoxia, catecholamines, nutrients, growth factors, and pancreatic vascularity. We focus on recent evidence from experimental interventions in established models of IUGR to understand better the pathophysiological mechanisms linking placental insufficiency with impaired islet development and β-cell function. © 2017 Society for Endocrinology.

  19. Pancreatic islet-cell viability, functionality and oxidative status ...

    Indian Academy of Sciences (India)

    Unknown

    Environmental factors such as diet, physical activity, drugs, pollution and life style play an important ... Antibiotics seem to have a correlation with diabetes and pancreatic function. ... altogether have a different effect in vitro than what is seen.

  20. The functional performance of microencapsulated human pancreatic islet-derived precursor cells.

    Science.gov (United States)

    Montanucci, Pia; Pennoni, Ilaria; Pescara, Teresa; Blasi, Paolo; Bistoni, Giovanni; Basta, Giuseppe; Calafiore, Riccardo

    2011-12-01

    We have examined long-term cultured, human islet-derived stem/precursor cells (hIPC). Whole human islets (HI) were obtained by multi-enzymatic digestion of cadaveric donor pancreases, plated on tissue flasks, and allowed to adhere and expand for several in vitro passages, in order to obtain hIPC. We detected specific stem cell markers (Oct-4, Sox-2, Nanog, ABCG2, Klf-4, CD117) in both intact HI and hIPC. Moreover, hIPC while retaining the expression of Glut-2, Pdx-1, CK-19, and ICA-512, started re-expressing Ngn3, thereby indicating acquisition of a specific pancreatic islet beta cell-oriented phenotype identity. The intrinsic plasticity of hIPC was documented by their ability to differentiate into various germ layer-derived cell phenotypes (ie, osteocytic, adipocytic and neural), including endocrine cells associated with insulin secretory capacity. To render hIPC suitable for transplantation we have enveloped them within our highly purified, alginate-based microcapsules. Upon intraperitoneal graft in NOD/SCID mice we have observed that the microcapsules acted as three-dimensional niches favouring post-transplant hIPC differentiation and acquisition of beta cell-like functional competence. Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. RBE of heavy ions (carbon, neon, helium, proton) for acute cell death of pancreatic islet cells

    International Nuclear Information System (INIS)

    Tsubouchi, Susumu; Fukutsu, Kumiko; Itsukaichi, Hiromi

    2003-01-01

    At this fiscal year, only two times irradiation experiments with neon and helium beams were performed to obtain relative biological effectiveness (RBE) of heavy ions (carbon, neon, helium, proton) for acute cell death of pancreatic islet cells in vivo. First of all this project was designed to obtain RBE of 290 MeV carbon and 400 MeV neon beams in the high linear energy transfer (LET) region for acute cell death of pancreatic islets of golden hamster (Mesocricetus auratus) in the condition of in both in vivo and in vitro systems. As mentioned in previous report, in vitro system, however, resulted in ill success. This in vitro experiment was tentatively shelved for the time being. In return in vivo experiments for low LET region of neon beams (32.5 KeV/u), carbon beams (15.0 KeV/u) and helium beams (2 KeV/u) were performed in these two years. Last year these results together with those previously obtained for 200 KeV X-ray, 70 MeV proton, 290 MeV carbon (60 KeV/u), and neon (100 KeV/u) beams were reconsidered. At this year dose response relations (25, 50, 100, 150, and 200 Gy respectively) in acute cell death of pancreatic islets studied histologically after whole body irradiation of 3 weeks young male golden hamster with lower LET helium beams (2 KeV/u) and neon beams (32.5 KeV/u). Results indicated that mean cell lethal dose (Do) of helium beams (2 KeV/u) and neon beams (32.5 KeV/u) were 38 Gy and 49 Gy, respectively. Previously obtained Do data for 200 KeV x-ray, 70 MeV proton, 290 MeV carbon (15 KeV/u), 400 MeV neon (32.5 KeV/u), 290 MeV carbon (60 KeV/u), and 400 MeV neon (100 KeV/u) beams were 37 Gy, 38 Gy, 38 Gy, 49 Gy, 75 Gy, and 200 Gy, respectively. From these data estimated RBE of neon (100 KeV/u and 32.5 KeV/u), carbon (60 KeV/u and 15.0 KeV/u), 70 MeV proton and 150 MeV helium (2 KeV/u) beams were 0.19, 0.76, 0.49, 0.97, 0.97, 0.97, respectively. Therefore the order of RBE (or radiosensitivities) of islets cells with these various heavy ion beams was

  2. Immunohistochemical detection of vimentin in pancreatic islet β- and α-cells of macrosomic infants of diabetic and nondiabetic mothers.

    Science.gov (United States)

    Krivova, Yuliya S; Proshchina, Alexandra E; Barabanov, Valeriy M; Barinova, Irina V; Saveliev, Sergey V

    2018-02-01

    Expression of the intermediate filament protein vimentin has been recently observed in the pancreatic islet β- and α-cells of humans with type 2 diabetes mellitus. It was suggested that the presence of vimentin in endocrine cells may indicate islet tissue renewal, or potentially represent the dedifferentiation of endocrine cells, which could contribute to the onset of type 2 diabetes or islet cell dysfunction. To analyze the expression of vimentin in pancreatic β- and α-cells of macrosomic infants of diabetic and nondiabetic mothers. Pancreatic samples of five macrosomic infants (gestational age 34-40weeks) from three diabetic and two nondiabetic mothers were compared to six control infants (32-40weeks, weight appropriate for gestational age) from normoglycemic mothers. Pancreatic autopsy samples were examined by double immunofluorescent labeling with antibodies against vimentin and either insulin or glucagon. Alterations in the endocrine pancreas were measured using morphometric methods, then data were statistically analyzed. In the pancreatic islets of macrosomic infants from diabetic and nondiabetic mothers, we observed vimentin-positive cells, some of which simultaneously contained insulin or glucagon. We also quantitatively showed that the presence of such cells was associated with hypertrophy and hyperplasia of the islets, and with an increase in β- and α-cell density. We speculate that the appearance of vimentin-positive islet cells may reflect induction of differentiation in response to the increased insulin demand, and vimentin may serve as an early marker of endocrine pancreas disorders. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. The voltage-gated proton channel Hv1 is expressed in pancreatic islet β-cells and regulates insulin secretion

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Qing [Department of Biophysics, School of Physics Science, The Key Laboratory of Bioactive Materials, Ministry of Education, Nankai University, Tianjin 300071 (China); Che, Yongzhe [School of Medicine, Nankai University, Tianjin 300071 (China); Li, Qiang; Zhang, Shangrong [Department of Biophysics, School of Physics Science, The Key Laboratory of Bioactive Materials, Ministry of Education, Nankai University, Tianjin 300071 (China); Gao, Ying-Tang [Key Laboratory of Artificial Cell, Third Central Clinical College of Tianjin Medical University, Tianjin 300170 (China); Wang, Yifan; Wang, Xudong; Xi, Wang; Zuo, Weiyan [Department of Biophysics, School of Physics Science, The Key Laboratory of Bioactive Materials, Ministry of Education, Nankai University, Tianjin 300071 (China); Li, Shu Jie, E-mail: shujieli@nankai.edu.cn [Department of Biophysics, School of Physics Science, The Key Laboratory of Bioactive Materials, Ministry of Education, Nankai University, Tianjin 300071 (China)

    2015-12-25

    The voltage-gated proton channel Hv1 is a potent acid extruder that participates in the extrusion of the intracellular acid. Here, we showed for the first time, Hv1 is highly expressed in mouse and human pancreatic islet β-cells, as well as β-cell lines. Imaging studies demonstrated that Hv1 resides in insulin-containing granules in β-cells. Knockdown of Hv1 with RNA interference significantly reduces glucose- and K{sup +}-induced insulin secretion in isolated islets and INS-1 (832/13) β-cells and has an impairment on glucose- and K{sup +}-induced intracellular Ca{sup 2+} homeostasis. Our data demonstrated that the expression of Hv1 in pancreatic islet β-cells regulates insulin secretion through regulating Ca{sup 2+} homeostasis.

  4. Current status and outlook of pancreatic islets transplantation research

    International Nuclear Information System (INIS)

    Wang Wei; Ye Bin

    2006-01-01

    Diabetes is a common disease, severely harmful to the human's health and life quality. The pancreatic islets transplantation can correct the patient's hyperglycemia, stop or even reverse the progress of the complication and thus decrease the mortality of diabetic patients. It is the most safe and efficient therapy for diabetes. Since the Edmonton Protocol got success in pancreatic islet transplantation in 2000, it has been more and more interested because of its great clinical curative effect. Research strategy of islet transplantation is now focussed on increasing the acquired islets with normal viability, selecting the best transplantation pathway, and improving the immunosuppression protocol. The shortage of human pancreatic donor is an ever unsolved problem in clinical application. The potential resolutions may include acquisition from xenogenic-islets; islets originated from stem cells, and islets from the living-donor human pancreas. The islets transplantation will open a new application field for interventional radiology. (authors)

  5. Islet Cells Serve as Cells of Origin of Pancreatic Gastrin-Positive Endocrine Tumors

    DEFF Research Database (Denmark)

    Bonnavion, Rémy; Teinturier, Romain; Jaafar, Rami

    2015-01-01

    The cells of origin of pancreatic gastrinomas remain an enigma, since no gastrin-expressing cells are found in the normal adult pancreas. It was proposed that the cellular origin of pancreatic gastrinomas may come from either the pancreatic cells themselves or gastrin-expressing cells which have ...

  6. General Information about Pancreatic Neuroendocrine Tumors (Islet Cell Tumors)

    Science.gov (United States)

    ... Common Cancer Types Recurrent Cancer Common Cancer Types Bladder Cancer Breast Cancer Colorectal Cancer Kidney (Renal Cell) Cancer ... also called nuclear magnetic resonance imaging (NMRI). Somatostatin receptor scintigraphy : A type of radionuclide scan that may ...

  7. Treatment Option Overview (Pancreatic Neuroendocrine Tumors / Islet Cell Tumors)

    Science.gov (United States)

    ... Common Cancer Types Recurrent Cancer Common Cancer Types Bladder Cancer Breast Cancer Colorectal Cancer Kidney (Renal Cell) Cancer ... also called nuclear magnetic resonance imaging (NMRI). Somatostatin receptor scintigraphy : A type of radionuclide scan that may ...

  8. Regulatory challenges in manufacturing of pancreatic islets.

    Science.gov (United States)

    Linetsky, E; Ricordi, C

    2008-03-01

    At the present time, transplantation of pancreatic islet cells is considered an experimental therapy for a selected cohort of patients with type 1 diabetes, and is conducted under an Investigational New Drug (IND) application. Encouraging results of the Edmonton Protocol published in the year 2000 sparked a renewed interest in clinical transplantation of allogeneic islets, triggering a large number of IND applications for phase I clinical trials. Promising results reported by a number of centers since then prompted the Food and Drug Administration (FDA) to consider the possibility of licensing allogeneic islets as a therapeutic treatment for patients with type 1 diabetes. However, prior to licensure, issues such as safety, purity, efficacy, and potency of the islet product must be addressed. This is complicated by the intricate nature of pancreatic islets and limited characterization prior to transplantation. In this context, control of the manufacturing process plays a critical role in the definition of the final product. Despite significant progress made in standardization of the donor organ preservation methods, reagents used, and characterization assays performed to qualify an islet cell product, control of the isolation process remains a challenge. Within the scope of the FDA regulations, islet cells meet the definition of a biologic product, somatic cell therapy, and a drug. In addition, AABB standards that address cellular therapy products apply to manufacturing facilities accredited by this organization. Control of the source material, isolation process, and final product are critical issues that must be addressed in the context of FDA and other relevant regulations applicable to islet cell products.

  9. Imaging of gene expression in live pancreatic islet cell lines using dual-isotope SPECT.

    Science.gov (United States)

    Tai, Joo Ho; Nguyen, Binh; Wells, R Glenn; Kovacs, Michael S; McGirr, Rebecca; Prato, Frank S; Morgan, Timothy G; Dhanvantari, Savita

    2008-01-01

    We are combining nuclear medicine with molecular biology to establish a sensitive, quantitative, and tomographic method with which to detect gene expression in pancreatic islet cells in vivo. Dual-isotope SPECT can be used to image multiple molecular events simultaneously, and coregistration of SPECT and CT images enables visualization of reporter gene expression in the correct anatomic context. We have engineered pancreatic islet cell lines for imaging with SPECT/CT after transplantation under the kidney capsule. INS-1 832/13 and alphaTC1-6 cells were stably transfected with a herpes simplex virus type 1-thymidine kinase-green fluorescent protein (HSV1-thymidine kinase-GFP) fusion construct (tkgfp). After clonal selection, radiolabel uptake was determined by incubation with 5-(131)I-iodo-1-(2-deoxy-2-fluoro-beta-d-arabinofuranosyl)uracil ((131)I-FIAU) (alphaTC1-6 cells) or (123)I-FIAU (INS-1 832/13 cells). For the first set of in vivo experiments, SPECT was conducted after alphaTC1-6/tkgfp cells had been labeled with either (131)I-FIAU or (111)In-tropolone and transplanted under the left kidney capsule of CD1 mice. Reconstructed SPECT images were coregistered to CT. In a second study using simultaneous acquisition dual-isotope SPECT, INS-1 832/13 clone 9 cells were labeled with (111)In-tropolone before transplantation. Mice were then systemically administered (123)I-FIAU and data for both (131)I and (111)In were acquired simultaneously. alphaTC1-6/tkgfp cells showed a 15-fold greater uptake of (131)I-FIAU, and INS-1/tkgfp cells showed a 12-fold greater uptake of (123)I-FIAU, compared with that of wild-type cells. After transplantation under the kidney capsule, both reporter gene expression and location of cells could be visualized in vivo with dual-isotope SPECT. Immunohistochemistry confirmed the presence of glucagon- and insulin-positive cells at the site of transplantation. Dual-isotope SPECT is a promising method to detect gene expression in and location of

  10. A Historical Perspective on the Identification of Cell Types in Pancreatic Islets of Langerhans by Staining and Histochemical Techniques.

    Science.gov (United States)

    Baskin, Denis G

    2015-08-01

    Before the middle of the previous century, cell types of the pancreatic islets of Langerhans were identified primarily on the basis of their color reactions with histological dyes. At that time, the chemical basis for the staining properties of islet cells in relation to the identity, chemistry and structure of their hormones was not fully understood. Nevertheless, the definitive islet cell types that secrete glucagon, insulin, and somatostatin (A, B, and D cells, respectively) could reliably be differentiated from each other with staining protocols that involved variations of one or more tinctorial techniques, such as the Mallory-Heidenhain azan trichrome, chromium hematoxylin and phloxine, aldehyde fuchsin, and silver impregnation methods, which were popularly used until supplanted by immunohistochemical techniques. Before antibody-based staining methods, the most bona fide histochemical techniques for the identification of islet B cells were based on the detection of sulfhydryl and disulfide groups of insulin. The application of the classical islet tinctorial staining methods for pathophysiological studies and physiological experiments was fundamental to our understanding of islet architecture and the physiological roles of A and B cells in glucose regulation and diabetes. © The Author(s) 2015.

  11. Activation of the Wnt/β-catenin pathway in pancreatic beta cells during the compensatory islet hyperplasia in prediabetic mice

    International Nuclear Information System (INIS)

    Maschio, D.A.; Oliveira, R.B.; Santos, M.R.; Carvalho, C.P.F.; Barbosa-Sampaio, H.C.L.; Collares-Buzato, C.B.

    2016-01-01

    The Wnt/β-catenin signaling pathway, also known as the canonical Wnt pathway, plays a role in cell proliferation and differentiation in several tissues/organs. It has been recently described in humans a relationship between type 2 diabetes (T2DM) and mutation in the gene encoding the transcription factor TCF7L2 associated to the Wnt/β-catenin pathway. In the present study, we demonstrated that hyperplastic pancreatic islets from prediabetic mice fed a high-fat diet (HFD) for 60 d displayed nuclear translocation of active β-catenin associated with significant increases in protein content and gene expression of β-catenin as well as of cyclins D1, D2 and c-Myc (target genes of the Wnt pathway) but not of Tcf7l2 (the transcription factor). Meanwhile, these alterations were not observed in pancreatic islets from 30 d HFD-fed mice, that do not display significant beta cell hyperplasia. These data suggest that the Wnt/β-catenin pathway is activated in pancreatic islets during prediabetes and may play a role in the induction of the compensatory beta cell hyperplasia observed at early phase of T2DM. - Highlights: • Exposure to high-fat diet for 60 days induced prediabetes and beta cell mass expansion. • Hyperplastic pancreatic islets displayed nuclear translocation of active β-catenin. • Hyperplastic islets showed increased expression of target genes of the Wnt/β-catenin pathway. • Wnt/β-catenin pathway is activated during compensatory beta cell hyperplasia in mice.

  12. A model for cell migration in non-isotropic fibrin networks with an application to pancreatic tumor islets.

    Science.gov (United States)

    Chen, Jiao; Weihs, Daphne; Vermolen, Fred J

    2018-04-01

    Cell migration, known as an orchestrated movement of cells, is crucially important for wound healing, tumor growth, immune response as well as other biomedical processes. This paper presents a cell-based model to describe cell migration in non-isotropic fibrin networks around pancreatic tumor islets. This migration is determined by the mechanical strain energy density as well as cytokines-driven chemotaxis. Cell displacement is modeled by solving a large system of ordinary stochastic differential equations where the stochastic parts result from random walk. The stochastic differential equations are solved by the use of the classical Euler-Maruyama method. In this paper, the influence of anisotropic stromal extracellular matrix in pancreatic tumor islets on T-lymphocytes migration in different immune systems is investigated. As a result, tumor peripheral stromal extracellular matrix impedes the immune response of T-lymphocytes through changing direction of their migration.

  13. Biotin uptake by mouse and human pancreatic beta cells/islets: a regulated, lipopolysaccharide-sensitive carrier-mediated process

    Science.gov (United States)

    Ghosal, Abhisek; Sekar, Thillai V.

    2014-01-01

    Biotin is essential for the normal function of pancreatic beta cells. These cells obtain biotin from their surroundings via transport across their cell membrane. Little is known about the uptake mechanism involved, how it is regulated, and how it is affected by internal and external factors. We addressed these issues using the mouse-derived pancreatic beta-TC-6 cells and freshly isolated mouse and human primary pancreatic beta cells as models. The results showed biotin uptake by pancreatic beta-TC-6 cells occurs via a Na+-dependent, carrier-mediated process, that is sensitive to desthiobiotin, as well as to pantothenic acid and lipoate; the process is also saturable as a function of concentration (apparent Km = 22.24 ± 5.5 μM). These cells express the sodium-dependent multivitamin transporter (SMVT), whose knockdown (with doxycycline-inducible shRNA) led to a sever inhibition in biotin uptake. Similarly, uptake of biotin by mouse and human primary pancreatic islets is Na+-dependent and carrier-mediated, and both cell types express SMVT. Biotin uptake by pancreatic beta-TC-6 cells is also adaptively regulated (via transcriptional mechanism) by extracellular substrate level. Chronic treatment of pancreatic beta-TC-6 cells with bacterial lipopolysaccharides (LPS) leads to inhibition in biotin uptake. This inhibition is mediated via a Toll-Like receptor 4-mediated process and involves a decrease in membrane expression of SMVT. These findings show, for the first time, that pancreatic beta cells/islets take up biotin via a specific and regulated carrier-mediated process, and that the process is sensitive to the effect of LPS. PMID:24904078

  14. Impact of Pancreatic Rat Islet Density on Cell Survival during Hypoxia

    Directory of Open Access Journals (Sweden)

    A. Rodriguez-Brotons

    2016-01-01

    Full Text Available In bioartificial pancreases (BP, the number of islets needed to restore normoglycaemia in the diabetic patient is critical. However, the confinement of a high quantity of islets in a limited space may impact islet survival, particularly in regard to the low oxygen partial pressure (PO2 in such environments. The aim of the present study was to evaluate the impact of islet number in a confined space under hypoxia on cell survival. Rat islets were seeded at three different concentrations (150, 300, and 600 Islet Equivalents (IEQ/cm2 and cultured in normal atmospheric pressure (160 mmHg as well as hypoxic conditions (15 mmHg for 24 hours. Cell viability, function, hypoxia-induced changes in gene expression, and cytokine secretion were then assessed. Notably, hypoxia appeared to induce a decrease in viability and increasing islet density exacerbated the observed increase in cellular apoptosis as well as the loss of function. These changes were also associated with an increase in inflammatory gene transcription. Taken together, these data indicate that when a high number of islets are confined to a small space under hypoxia, cell viability and function are significantly impacted. Thus, in order to improve islet survival in this environment during transplantation, oxygenation is of critical importance.

  15. Glucose decouples intracellular Ca2+ activity from glucagon secretion in mouse pancreatic islet alpha-cells.

    Directory of Open Access Journals (Sweden)

    Sylvain J Le Marchand

    Full Text Available The mechanisms of glucagon secretion and its suppression by glucose are presently unknown. This study investigates the relationship between intracellular calcium levels ([Ca(2+](i and hormone secretion under low and high glucose conditions. We examined the effects of modulating ion channel activities on [Ca(2+](i and hormone secretion from ex vivo mouse pancreatic islets. Glucagon-secreting α-cells were unambiguously identified by cell specific expression of fluorescent proteins. We found that activation of L-type voltage-gated calcium channels is critical for α-cell calcium oscillations and glucagon secretion at low glucose levels. Calcium channel activation depends on K(ATP channel activity but not on tetrodotoxin-sensitive Na(+ channels. The use of glucagon secretagogues reveals a positive correlation between α-cell [Ca(2+](i and secretion at low glucose levels. Glucose elevation suppresses glucagon secretion even after treatment with secretagogues. Importantly, this inhibition is not mediated by K(ATP channel activity or reduction in α-cell [Ca(2+](i. Our results demonstrate that glucose uncouples the positive relationship between [Ca(2+](i and secretory activity. We conclude that glucose suppression of glucagon secretion is not mediated by inactivation of calcium channels, but instead, it requires a calcium-independent inhibitory pathway.

  16. Total pancreatectomy with islet cell autotransplantation as the initial treatment for minimal-change chronic pancreatitis.

    Science.gov (United States)

    Wilson, Gregory C; Sutton, Jeffrey M; Smith, Milton T; Schmulewitz, Nathan; Salehi, Marzieh; Choe, Kyuran A; Brunner, John E; Abbott, Daniel E; Sussman, Jeffrey J; Ahmad, Syed A

    2015-03-01

    Patients with minimal-change chronic pancreatitis (MCCP) are traditionally managed medically with poor results. This study was conducted to review outcomes following total pancreatectomy with islet cell autotransplantation (TP/IAT) as the initial surgical procedure in the treatment of MCCP. All patients submitted to TP/IAT for MCCP were identified for inclusion in a single-centre observational study. A retrospective chart review was performed to identify pertinent preoperative, perioperative and postoperative data. A total of 84 patients with a mean age of 36.5 years (range: 15-60 years) underwent TP/IAT as the initial treatment for MCCP. The most common aetiology of chronic pancreatitis in this cohort was idiopathic (69.0%, n = 58), followed by aetiologies associated with genetic mutations (16.7%, n = 14), pancreatic divisum (9.5%, n = 8), and alcohol (4.8%, n = 4). The most common genetic mutations pertained to CFTR (n = 9), SPINK1 (n = 3) and PRSS1 (n = 2). Mean ± standard error of the mean preoperative narcotic requirements were 129.3 ± 18.7 morphine-equivalent milligrams (MEQ)/day. Overall, 58.3% (n = 49) of patients achieved narcotic independence and the remaining patients required 59.4 ± 10.6 MEQ/day (P < 0.05). Postoperative insulin independence was achieved by 36.9% (n = 31) of patients. The Short-Form 36-Item Health Survey administered postoperatively demonstrated improvement in all tested quality of life subscales. The present report represents one of the largest series demonstrating the benefits of TP/IAT in the subset of patients with MCCP. © 2014 International Hepato-Pancreato-Biliary Association.

  17. Completion pancreatectomy and islet cell autotransplantation as salvage therapy for patients failing previous operative interventions for chronic pancreatitis.

    Science.gov (United States)

    Wilson, Gregory C; Sutton, Jeffrey M; Smith, Milton T; Schmulewitz, Nathan; Salehi, Marzieh; Choe, Kyuran A; Levinsky, Nick C; Brunner, John E; Abbott, Daniel E; Sussman, Jeffrey J; Edwards, Michael J; Ahmad, Syed A

    2015-10-01

    Traditional decompressive and/or pancreatic resection procedures have been the cornerstone of operative therapy for refractory abdominal pain secondary to chronic pancreatitis. Management of patients that fail these traditional interventions represents a clinical dilemma. Salvage therapy with completion pancreatectomy and islet cell autotransplantation (CPIAT) is an emerging treatment option for this patient population; however, outcomes after this procedure have not been well-studied. All patients undergoing CPIAT after previous decompressive and/or pancreatic resection for the treatment of chronic pancreatitis at our institution were identified for inclusion in this single-center observational study. Study end points included islet yield, narcotic requirements, glycemic control, and quality of life (QOL). QOL was assessed using the Short Form (SF)-36 health questionnaire. Sixty-four patients underwent CPIAT as salvage therapy. The median age at time of CPIAT was 38 years (interquartile range [IQR], 14.7-65.4). The most common etiology of chronic pancreatitis was idiopathic pancreatitis (66%; n = 42) followed by genetically linked pancreatitis (9%; n = 6) and alcoholic pancreatitis (8%; n = 5). All of these patients had previously undergone prior limited pancreatic resection or decompressive procedure. The majority of patients (50%; n = 32) underwent prior pancreaticoduodenectomy, whereas the remainder had undergone distal pancreatectomy (17%; n = 11), Frey (13%; n = 8), Puestow (13%; n = 8), or Berne (8%; n = 5) procedures. Median time from initial surgical intervention to CPIAT was 28.1 months (IQR, 13.6-43.0). All of these patients underwent a successful CPIAT. Mean operative time was 502.2 minutes with average hospital duration of stay of 13 days. Islet cell isolation was feasible despite previous procedures with a mean islet yield of 331,304 islet cell equivalents, which totaled an islet cell autotransplantation of 4,737 ± 492 IEQ/kg body weight. Median

  18. Pancreatic Islet Transplantation

    Science.gov (United States)

    ... auto-transplantation is performed following total pancreatectomy—the surgical removal of the whole pancreas—in patients with severe and chronic, or long lasting, pancreatitis that cannot be managed by other treatments. This procedure is not considered experimental. Patients with ...

  19. Vanadyl Sulfate Treatment Stimulates Proliferation and Regeneration of Beta Cells in Pancreatic Islets

    Directory of Open Access Journals (Sweden)

    Samira Missaoui

    2014-01-01

    Full Text Available We examined the effects of vanadium sulfate (VOSO4 treatment at 5 and 10 mg/kg for 30 days on endocrine pancreas activity and histology in nondiabetic and STZ-induced diabetic rats. In diabetic group, blood glucose levels significantly increased while insulinemia level markedly decreased. At the end of treatment, VOSO4 at a dose of 10 mg/Kg normalized blood glucose level in diabetic group, restored insulinemia, and significantly improved insulin sensitivity. VOSO4 also increased in a dose-dependent manner the number of insulin immunopositive beta cells in pancreatic islets of nondiabetic rats. Furthermore, in the STZ-diabetic group, the decrease in the number of insulin immunopositive beta cells was corrected to reach the control level mainly with the higher dose of vanadium. Therefore, VOSO4 treatment normalized plasma glucose and insulin levels and improved insulin sensitivity in STZ-experimental diabetes and induced beta cells proliferation and/or regeneration in normal or diabetic rats.

  20. Microcapsules with intrinsic barium radiopacity for immunoprotection and X-ray/CT imaging of pancreatic islet cells.

    Science.gov (United States)

    Arifin, Dian R; Manek, Sameer; Call, Emma; Arepally, Aravind; Bulte, Jeff W M

    2012-06-01

    Microencapsulation is a commonly used technique for immunoprotection of engrafted therapeutic cells. We investigated a library of capsule formulations to determine the most optimal formulation for pancreatic beta islet cell transplantation, using barium as the gelating ion and clinical-grade protamine sulfate (PS) as a new cationic capsule cross-linker. Barium-gelated alginate/PS/alginate microcapsules (APSA, diameter = 444 ± 21 μm) proved to be mechanically stronger and supported a higher cell viability as compared to conventional alginate/poly-l-lysine/alginate (APLLA) capsules. Human pancreatic islets encapsulated inside APSA capsules, gelated with 20 mm barium as optimal concentration, exhibited a sustained morphological integrity, viability, and functionality for at least 3-4 weeks in vitro, with secreted human C-peptide levels of 0.2-160 pg/ml/islet. Unlike APLLA capsules that are gelled with calcium, barium-APSA capsules are intrinsically radiopaque and, when engrafted into mice, could be readily imaged in vivo with micro-computed tomography (CT). Without the need of adding contrast agents, these capsules offer a clinically applicable alternative for simultaneous immunoprotection and real-time, non-invasive X-ray/CT monitoring of engrafted cells during and after in vivo administration. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. Mechanisms of pancreatic islet cell destruction. Dose-dependent cytotoxic effect of soluble blood mononuclear cell mediators on isolated islets of Langerhans

    DEFF Research Database (Denmark)

    Mandrup-Poulsen, T; Bendtzen, K; Nerup, J

    1986-01-01

    Supernatants of peripheral blood mononuclear cells from healthy human donors stimulated with recall antigen (purified protein derivative of tuberculin) or lectin (phytohaemagglutinin) markedly inhibited the insulin release from isolated human and rat islets of Langerhans, and decreased rat islet...... reconstituted with tuberculin or phytohaemagglutinin did not impair islet function. Electron microscopy demonstrated that supernatants were cytotoxic to islet cells. The cytotoxic mononuclear cell mediator(s) was non-dialysable, sensitive to heating to 56 degrees C, labile even when stored at -70 degrees C...

  2. Islet-selectivity of G-protein coupled receptor ligands evaluated for PET imaging of pancreatic {beta}-cell mass

    Energy Technology Data Exchange (ETDEWEB)

    Cline, Gary W., E-mail: gary.cline@yale.edu [Yale University School of Medicine (United States); Zhao, Xiaojian [Yale University School of Medicine (United States); Jakowski, Amy B.; Soeller, Walter C.; Treadway, Judith L. [Pfizer Global Research and Development, Pfizer Inc., Groton CT (United States)

    2011-09-02

    Highlights: {yields} We screened G-protein coupled receptors for imaging pancreatic. {yields} Database mining and immunohistochemistry identified GPCRs enriched in {beta}-cells. {yields} In vitro and in vivo assays were used to determine exocrine vs endocrine specificity. {yields} GPCR candidates for imaging of {beta}-cell mass are Prokineticin-1R, mGluR5, and GLP-1R. -- Abstract: A critical unmet need exists for methods to quantitatively measure endogenous pancreatic {beta}-cell mass (BCM) for the clinical evaluation of therapies to prevent or reverse loss of BCM and diabetes progression. Our objective was to identify G-protein coupled receptors (GPCRs) that are expressed with a high degree of specificity to islet {beta}-cells for receptor-targeted imaging of BCM. GPCRs enriched in pancreatic islets relative to pancreas acinar and hepatic tissue were identified using a database screen. Islet-specific expression was confirmed by human pancreas immunohistochemistry (IHC). In vitro selectivity assessment was determined from the binding and uptake of radiolabeled ligands to the rat insulinoma INS-1 832/13 cell line and isolated rat islets relative to the exocrine pancreas cell-type, PANC-1. Tail-vein injections of radioligands into rats were used to determine favorable image criteria of in vivo biodistribution to the pancreas relative to other internal organs (i.e., liver, spleen, stomach, and lungs). Database and IHC screening identified four candidate receptors for further in vitro and in vivo evaluation for PET imaging of BCM: prokineticin-1 receptor (PK-1R), metabotropic glutamate receptor type-5 (mGluR5), neuropeptide Y-2 receptor (NPY-2R), and glucagon-like peptide 1 receptor (GLP-1R). In vitro specificity ratios gave the following receptor rank order: PK-1R > GLP-1R > NPY-2R > mGluR5. The biodistribution rank order of selectivity to the pancreas was found to be PK-1R > VMAT2 {approx} GLP-1R > mGluR5. Favorable islet selectivity and biodistribution

  3. Islet-selectivity of G-protein coupled receptor ligands evaluated for PET imaging of pancreatic β-cell mass

    International Nuclear Information System (INIS)

    Cline, Gary W.; Zhao, Xiaojian; Jakowski, Amy B.; Soeller, Walter C.; Treadway, Judith L.

    2011-01-01

    Highlights: → We screened G-protein coupled receptors for imaging pancreatic. → Database mining and immunohistochemistry identified GPCRs enriched in β-cells. → In vitro and in vivo assays were used to determine exocrine vs endocrine specificity. → GPCR candidates for imaging of β-cell mass are Prokineticin-1R, mGluR5, and GLP-1R. -- Abstract: A critical unmet need exists for methods to quantitatively measure endogenous pancreatic β-cell mass (BCM) for the clinical evaluation of therapies to prevent or reverse loss of BCM and diabetes progression. Our objective was to identify G-protein coupled receptors (GPCRs) that are expressed with a high degree of specificity to islet β-cells for receptor-targeted imaging of BCM. GPCRs enriched in pancreatic islets relative to pancreas acinar and hepatic tissue were identified using a database screen. Islet-specific expression was confirmed by human pancreas immunohistochemistry (IHC). In vitro selectivity assessment was determined from the binding and uptake of radiolabeled ligands to the rat insulinoma INS-1 832/13 cell line and isolated rat islets relative to the exocrine pancreas cell-type, PANC-1. Tail-vein injections of radioligands into rats were used to determine favorable image criteria of in vivo biodistribution to the pancreas relative to other internal organs (i.e., liver, spleen, stomach, and lungs). Database and IHC screening identified four candidate receptors for further in vitro and in vivo evaluation for PET imaging of BCM: prokineticin-1 receptor (PK-1R), metabotropic glutamate receptor type-5 (mGluR5), neuropeptide Y-2 receptor (NPY-2R), and glucagon-like peptide 1 receptor (GLP-1R). In vitro specificity ratios gave the following receptor rank order: PK-1R > GLP-1R > NPY-2R > mGluR5. The biodistribution rank order of selectivity to the pancreas was found to be PK-1R > VMAT2 ∼ GLP-1R > mGluR5. Favorable islet selectivity and biodistribution characteristics suggest several GPCRs as potential

  4. Comparison of therapeutic characteristics of islet cell transplantation simultaneous with pancreatic mesenchymal stem cell transplantation in rats with Type 1 diabetes mellitus.

    Science.gov (United States)

    Unsal, Ilknur Ozturk; Ginis, Zeynep; Pinarli, Ferda Alparslan; Albayrak, Aynur; Cakal, Erman; Sahin, Mustafa; Delibasi, Tuncay

    2015-06-01

    Although, pancreas islet call transplantation is a new, promising method for type 1 diabetic patients, it remains as an experimental procedure applied in selected patients. The present study aimed to investigate effect of pancreatic mesenchymal stem cell transplantation simultaneous with islet cell transplantation on islet liveliness and thus on the treatment of diabetes in type 1 diabetic rats. The study used Wistar Albino Rats and was performed in a total of four groups [control (G1), mesenchymal stem cell (G2), islet (G3) and islet + mesencymal stem cell (G4)] each including 8 rats. Blood glucose level of the rats, in which diabetes model has been created using streptozotocin, was measured after 72 h. Blood samples were obtained from the rats 30 days after transplantation and then, their livers and pancreases were kept in 10% formaldehyde and the experiment was ended. Following staining with H&E, they were morphologically evaluated under a light microscope. Change in mean blood glucose level was statistically significant in G3 and G4 versus G1 and G2 (p = 0.001, p islet cells in the pancreases of the rats was higher in G4; difference between the groups was statistically significant (p Transplantation of islet cells together with mesenchymal stem cells showed beneficial effects in terms of prolonging survival of islet grafts suggesting that transplantation of mesenchymal stem cells together with islet cells during clinical islet transplantation may be beneficial in increasing the number of noninsulin-dependent patients in Type 1 diabetes.

  5. Type 1 Diabetes Candidate Genes Linked to Pancreatic Islet Cell Inflammation and Beta-Cell Apoptosis

    DEFF Research Database (Denmark)

    Størling, Joachim; Pociot, Flemming

    2017-01-01

    (GWAS) have identified more than 50 genetic regions that affect the risk of developing T1D. Most of these susceptibility loci, however, harbor several genes, and the causal variant(s) and gene(s) for most of the loci remain to be established. A significant part of the genes located in the T1D...... susceptibility loci are expressed in human islets and β cells and mounting evidence suggests that some of these genes modulate the β-cell response to the immune system and viral infection and regulate apoptotic β-cell death. Here, we discuss the current status of T1D susceptibility loci and candidate genes...

  6. Intraocular in vivo imaging of pancreatic islet cell physiology/pathology

    Directory of Open Access Journals (Sweden)

    Ingo B. Leibiger

    2017-09-01

    Major conclusions: Data provided by us and others demonstrate the high versatility of this imaging platform. The use of ‘reporter islets’ engrafted in the eye, reporting on the status of in situ endogenous islets in the pancreas of the same animal, allows the identification of key-events in the development and progression of diabetes. This will not only serve as a versatile research tool but will also lay the foundation for a personalized medicine approach and will serve as a screening platform for new drugs and/or treatment protocols. ‘Metabolic’ islet transplantation, in which islets engrafted in the eye replace the endogenous beta cells, will allow for the establishment of islet-specific transgenic models and ‘humanized’ mouse models as well as serving as the basis for a new clinical transplantation site for the cure of diabetes.

  7. Pancreatic islet regeneration: Therapeutic potential, unknowns and controversy

    Directory of Open Access Journals (Sweden)

    Ingrid L. Cockburn

    2015-07-01

    Full Text Available Glucose homeostasis in mammals is primarily maintained by the insulin-secreting β-cells contained within pancreas-resident islets of Langerhans. Gross disruption of this glucose regulation as a result of pancreatic dysfunction frequently results in diabetes, which is currently a major health concern in South Africa, as well as globally. For many years, researchers have realised that the pancreas, and specifically the islets of Langerhans, have a regenerative capacity, as islet mass has frequently been shown to increase following induced pancreatic injury. Given that gross β-cell loss contributes significantly to the pathogenesis of both type 1 and type 2 diabetes, endogenous pancreatic islet regeneration has been investigated extensively as a potential β-cell replacement therapy for diabetes. From the extensive research conducted on pancreatic regeneration, opposing findings and opinions have arisen as to how, and more recently even if, pancreatic regeneration occurs following induced injury. In this review, we outline and discuss the three primary mechanisms by which pancreatic regeneration is proposed to occur: neogenesis, β-cell replication and transdifferentiation. We further explain some of the advanced techniques used in pancreatic regeneration research, and conclude that despite the technologically advanced research tools available to researchers today, the mechanisms governing pancreatic regeneration may remain elusive until more powerful techniques are developed to allow for real-time, live-cell assessment of morphology and gene expression within the pancreas.

  8. Palmitate activates autophagy in INS-1E β-cells and in isolated rat and human pancreatic islets.

    Directory of Open Access Journals (Sweden)

    Luisa Martino

    Full Text Available We have investigated the in vitro effects of increased levels of glucose and free fatty acids on autophagy activation in pancreatic beta cells. INS-1E cells and isolated rat and human pancreatic islets were incubated for various times (from 2 to 24 h at different concentrations of glucose and/or palmitic acid. Then, cell survival was evaluated and autophagy activation was explored by using various biochemical and morphological techniques. In INS-1E cells as well as in rat and human islets, 0.5 and 1.0 mM palmitate markedly increased autophagic vacuole formation, whereas high glucose was ineffective alone and caused little additional change when combined with palmitate. Furthermore, LC3-II immunofluorescence co-localized with that of cathepsin D, a lysosomal marker, showing that the autophagic flux was not hampered in PA-treated cells. These effects were maintained up to 18-24 h incubation and were associated with a significant decline of cell survival correlated with both palmitate concentration and incubation time. Ultrastructural analysis showed that autophagy activation, as evidenced by the occurrence of many autophagic vacuoles in the cytoplasm of beta cells, was associated with a diffuse and remarkable swelling of the endoplasmic reticulum. Our results indicate that among the metabolic alterations typically associated with type 2 diabetes, high free fatty acids levels could play a role in the activation of autophagy in beta cells, through a mechanism that might involve the induction of endoplasmic reticulum stress.

  9. Autologous islet transplantation with remote islet isolation after pancreas resection for chronic pancreatitis.

    Science.gov (United States)

    Tai, Denise S; Shen, Na; Szot, Gregory L; Posselt, Andrew; Feduska, Nicholas J; Habashy, Andrew; Clerkin, Barbara; Core, Erin; Busuttil, Ronald W; Hines, O Joe; Reber, Howard A; Lipshutz, Gerald S

    2015-02-01

    Autologous islet transplantation is an elegant and effective method for preserving euglycemia in patients undergoing near-total or total pancreatectomy for severe chronic pancreatitis. However, few centers worldwide perform this complex procedure, which requires interdisciplinary coordination and access to a sophisticated Food and Drug Administration-licensed islet-isolating facility. To investigate outcomes from a single institutional case series of near-total or total pancreatectomy and autologous islet transplantation using remote islet isolation. Retrospective cohort study between March 1, 2007, and December 31, 2013, at tertiary academic referral centers among 9 patients (age range, 13-47 years) with chronic pancreatitis and reduced quality of life after failed medical management. Pancreas resection, followed by transport to a remote facility for islet isolation using a modified Ricordi technique, with immediate transplantation via portal vein infusion. Islet yield, pain assessment, insulin requirement, costs, and transport time. Eight of nine patients had successful islet isolation after near-total or total pancreatectomy. Four of six patients with total pancreatectomy had islet yields exceeding 5000 islet equivalents per kilogram of body weight. At 2 months after surgery, all 9 patients had significantly reduced pain or were pain free. Of these patients, 2 did not require insulin, and 1 required low doses. The mean transport cost was $16,527, and the mean transport time was 3½ hours. Pancreatic resection with autologous islet transplantation for severe chronic pancreatitis is a safe and effective final alternative to ameliorate debilitating pain and to help prevent the development of surgical diabetes. Because many centers lack access to an islet-isolating facility, we describe our experience using a regional 2-center collaboration as a successful model to remotely isolate cells, with outcomes similar to those of larger case series.

  10. Entrapment of dispersed pancreatic islet cells in CultiSpher-S macroporous gelatin microcarriers : Preparation, in vitro characterization, and microencapsulation

    NARCIS (Netherlands)

    Del Guerra, S; Bracci, C; Nilsson, K; Belcourt, A; Kessler, L; Lupi, R; Marselli, L; De Vos, P; Marchetti, P

    2001-01-01

    Immunoprotection of pancreatic islets for successful allo- or xenotransplantation without chronic immunosuppression is an attractive, but still elusive, approach for curing type 1 diabetes. It was recently shown that, even in the absence of fibrotic overgrowth, other factors, mainly insufficient

  11. A study of the pancreatic islet β-cell function and insulin resistance of type2 diabetic gastroparesis

    International Nuclear Information System (INIS)

    Zou Gang; Shao Hao; Lu Zeyuan; Ding Yuzhen; Chen Guanrong; Fu Juan

    2005-01-01

    Objective: To study the pancreatic islet β-cell function and insulin resistance of diabetic gastroparesis (DGP). Methods: 31 subjects with normal glucose tolerance (NGT), 32 subjects with impaired glucose tolerance (IGT), 38 subjects with type 2 diabetes mellitus (T2DM) and 31 subjects with DGP were en-rolled in the study, assessed by steamed bread meal tests, the plasma glucose and insulin at 0, 30, 60, 120 and 180 min were respectively measured by using glucose oxidase and radioimmunoassay, investigate the changes of area under insulin cure (INSAUC), Homa-insulin resistance (Homa-IR) index and modified β-cell function index (MBCI). Results: The INSAUC of IGT, T2DM, NGT and DGP fell in turn, there were signif-icantly differences among the groups. The Homa-IR index of NGT, IGT, DGP and T2DM rose in turn, there were significantly differences among the groupsexcept between T2DM and DGP. Conclusions: The pancreatic islet β-cell function of DGP was worse that NGT, IGT and T2DM, and the insulin resistance was stronger than NGT and IGT. (authors)

  12. Differential expression of neural cell adhesion molecule and cadherins in pancreatic islets, glucagonomas, and insulinomas

    DEFF Research Database (Denmark)

    Møller, C J; Christgau, S; Williamson, M R

    1992-01-01

    The endocrine cells of the pancreas develop from the endoderm and yet display several characteristics of a neuronal phenotype. During embryonic life, ductal epithelial cells give rise to first the glugagon-producing cells (alpha-cells) and then cells that express insulin (beta-cells), somatostatin...... primary islet cells at all ages express unsialylated NCAM and E-cadherin, as do insulinomas, the glucagonomas express the polysialylated NCAM, which is characteristic for developing neurons. The glucagonomas also lose E-cadherin expression and instead express a cadherin which is similar to N...

  13. Pancreatic hormones are expressed on the surfaces of human and rat islet cells through exocytotic sites

    DEFF Research Database (Denmark)

    Larsson, L I; Hutton, J C; Madsen, O D

    1989-01-01

    . Electron microscopy reveals the labeling to occur at sites of exocytotic granule release, involving the surfaces of extruded granule cores. The surfaces of islet cells were labeled both by polyclonal and monoclonal antibodies, excluding that receptor-interacting, anti-idiotypic hormone antibodies were...... for these results. It is concluded that the staining reflects interactions between the appropriate antibodies and exocytotic sites of hormone release....

  14. Autologous Pancreatic Islet Transplantation in Human Bone Marrow

    Science.gov (United States)

    Maffi, Paola; Balzano, Gianpaolo; Ponzoni, Maurilio; Nano, Rita; Sordi, Valeria; Melzi, Raffaella; Mercalli, Alessia; Scavini, Marina; Esposito, Antonio; Peccatori, Jacopo; Cantarelli, Elisa; Messina, Carlo; Bernardi, Massimo; Del Maschio, Alessandro; Staudacher, Carlo; Doglioni, Claudio; Ciceri, Fabio; Secchi, Antonio; Piemonti, Lorenzo

    2013-01-01

    The liver is the current site of choice for pancreatic islet transplantation, even though it is far from being ideal. We recently have shown in mice that the bone marrow (BM) may be a valid alternative to the liver, and here we report a pilot study to test feasibility and safety of BM as a site for islet transplantation in humans. Four patients who developed diabetes after total pancreatectomy were candidates for the autologous transplantation of pancreatic islet. Because the patients had contraindications for intraportal infusion, islets were infused in the BM. In all recipients, islets engrafted successfully as shown by measurable posttransplantation C-peptide levels and histopathological evidence of insulin-producing cells or molecular markers of endocrine tissue in BM biopsy samples analyzed during follow-up. Thus far, we have recorded no adverse events related to the infusion procedure or the presence of islets in the BM. Islet function was sustained for the maximum follow-up of 944 days. The encouraging results of this pilot study provide new perspectives in identifying alternative sites for islet infusion in patients with type 1 diabetes. Moreover, this is the first unequivocal example of successful engraftment of endocrine tissue in the BM in humans. PMID:23733196

  15. Oxygenation of the Intraportally Transplanted Pancreatic Islet.

    Science.gov (United States)

    Suszynski, Thomas M; Avgoustiniatos, Efstathios S; Papas, Klearchos K

    2016-01-01

    Intraportal islet transplantation (IT) is not widely utilized as a treatment for type 1 diabetes. Oxygenation of the intraportally transplanted islet has not been studied extensively. We present a diffusion-reaction model that predicts the presence of an anoxic core and a larger partly functional core within intraportally transplanted islets. Four variables were studied: islet diameter, islet fractional viability, external oxygen partial pressure ( P ) (in surrounding portal blood), and presence or absence of a thrombus on the islet surface. Results indicate that an islet with average size and fractional viability exhibits an anoxic volume fraction (AVF) of 14% and a function loss of 72% at a low external P . Thrombus formation increased AVF to 30% and function loss to 92%, suggesting that the effect of thrombosis may be substantial. External P and islet diameter accounted for the greatest overall impact on AVF and loss of function. At our institutions, large human alloislets (>200 μ m diameter) account for ~20% of total islet number but ~70% of total islet volume; since most of the total transplanted islet volume is accounted for by large islets, most of the intraportal islet cells are likely to be anoxic and not fully functional.

  16. Oxygenation of the Intraportally Transplanted Pancreatic Islet

    Directory of Open Access Journals (Sweden)

    Thomas M. Suszynski

    2016-01-01

    Full Text Available Intraportal islet transplantation (IT is not widely utilized as a treatment for type 1 diabetes. Oxygenation of the intraportally transplanted islet has not been studied extensively. We present a diffusion-reaction model that predicts the presence of an anoxic core and a larger partly functional core within intraportally transplanted islets. Four variables were studied: islet diameter, islet fractional viability, external oxygen partial pressure (P (in surrounding portal blood, and presence or absence of a thrombus on the islet surface. Results indicate that an islet with average size and fractional viability exhibits an anoxic volume fraction (AVF of 14% and a function loss of 72% at a low external P. Thrombus formation increased AVF to 30% and function loss to 92%, suggesting that the effect of thrombosis may be substantial. External P and islet diameter accounted for the greatest overall impact on AVF and loss of function. At our institutions, large human alloislets (>200 μm diameter account for ~20% of total islet number but ~70% of total islet volume; since most of the total transplanted islet volume is accounted for by large islets, most of the intraportal islet cells are likely to be anoxic and not fully functional.

  17. Pancreatic islet-like clusters from bone marrow mesenchymal stem cells of human first-trimester abortus can cure streptozocin-induced mouse diabetes.

    Science.gov (United States)

    Zhang, Yihua; Shen, Wenzheng; Hua, Jinlian; Lei, Anmin; Lv, Changrong; Wang, Huayan; Yang, Chunrong; Gao, Zhimin; Dou, Zhongying

    2010-12-01

    Bone marrow mesenchymal stem cells (BMSCs) have been reported to possess low immunogenicity and cause immunosuppression of recipients when allografted. They can differentiate into insulin-producing cells and may be a valuable source for islet formation. However, the extremely low differentiating rate of adult BMSCs toward insulin-producing cells and the insufficient insulin secretion of the differentiated BMSCs in vitro prevent their clinical use in diabetes treatment. Little is known about the potential of cell replacement therapy with human BMSCs. Previously, we isolated and identified human first-trimester fetal BMSCs (hfBMSCs). Under a novel four-step induction procedure established in this study, the hfBMSCs effectively differentiated into functional pancreatic islet-like cell clusters that contained 62 ± 14% insulin-producing cells, expressed a broad gene profile related to pancreatic islet β-cell development, and released high levels of insulin (2.245 ± 0.222 pmol/100 clusters per 30 min) and C-peptide (2.200 ± 0.468 pmol/100 clusters per 30 min) in response to 25 mmol/L glucose stimulus in vitro. The pancreatic islet-like cell clusters normalized the blood glucose level of diabetic model mice for at least 9 weeks when xenografted; blood glucose levels in these mice rose abnormally again when the grafts were removed. Examination of the grafts indicated that the transplanted cells survived in recipients and produced human insulin and C-peptide in situ. These results demonstrate that hfBMSCs derived from a human first-trimester abortus can differentiate into pancreatic islet-like cell clusters following an established four-step induction. The insulin-producing clusters present advantages in cell replacement therapy of type 1 diabetic model mice.

  18. Cyclic AMP in rat pancreatic islets

    International Nuclear Information System (INIS)

    Grill, V.; Borglund, E.; Cerasi, E.; Uppsala Univ.

    1977-01-01

    The incorporation of [ 3 H]adenine into cyclic AMP was studied in rat pancreatic islets under varying conditions of labeling. Prolonging the exposure to [ 3 H]adenine progressively augmented the islet cyclic [ 3 H]AMP level. Islets labeled for different periods of time and subsequently incubated (without adenine) in the presence of D-glucose or cholera toxin showed stimulations of intra-islet cyclic [ 3 H]AMP that were proportionate to the levels of radioactive nucleotide present under non-stimulatory conditions. Labeling the islets in a high glucose concentration (27.7 mM) did not modify the nucleotide responses to glucose or cholera toxin. The specific activity of cyclic [ 3 H]AMP, determined by simultaneous assay of cyclic [ 3 H]AMP and total cyclic AMP, was not influenced by glucose or cholera toxin. Glucose had no effect on the specific activity of labeled ATP

  19. Pancreatic islet transplantation. Experimental and clinical aspects

    DEFF Research Database (Denmark)

    Yderstræde, Knud Bonnet

    1987-01-01

    interest has been shown in transplantation of isolated islets either directly, introduced intraportally, intramuscularly, inter alia, or encapsulated in artificial devices providing an immuno-isolation. Clinical application has revealed promising results concerning the immunological aspects. However......, quantitative assessment points to a difficulty in achieving satisfactory amounts of islets to attain normoglycaemia. Work with fetal pancreata has shown these to possess a growth potential in vitro thus, possibly, aiding the quantification of islets in transplantation models. In the field of pancreatic islet...... transplantation, future models include microencapsulation and hybrid artificial devices, both of which provide immuno-isolation - thus the ability of allo- as well as xeno-transplantation. The obvious advantage of immuno-isolated islet transplant, as opposed to segmentally engrafted pancreas, is stressed...

  20. Preservation of beta cell function in adult human pancreatic islets for several months in vitro

    DEFF Research Database (Denmark)

    Brunstedt, J; Andersson, A; Frimodt-Møller, C

    1979-01-01

    Islets of Langerhans were isolated from four human kidney donors, aged 16 to 21 years by the collagenase method described for isolation of rodent islets. So far the human islets have been kept in tissue culture, without attachment, in medium RPMI 1640 supplemented with 10% calf serum for more tha...... technique presents a valuable tool for studying chronic effects of metabolites and hormones on islet function, as well as for islet storage prior to transplantation into humans.......Islets of Langerhans were isolated from four human kidney donors, aged 16 to 21 years by the collagenase method described for isolation of rodent islets. So far the human islets have been kept in tissue culture, without attachment, in medium RPMI 1640 supplemented with 10% calf serum for more than...

  1. Reprogramming human umbilical cord mesenchymal stromal cells to islet-like cells with the use of in vitro-synthesized pancreatic-duodenal homebox 1 messenger RNA.

    Science.gov (United States)

    Wang, Xiao Li; Hu, Pei; Guo, Xing Rong; Yan, Ding; Yuan, Yahong; Yan, Shi Rong; Li, Dong Sheng

    2014-11-01

    Human umbilical cord mesenchymal stromal cells (hUC-MSCs) hold great potential as a therapeutic candidate to treat diabetes, owing to their unlimited source and ready availability. In this study, we differentiated hUC-MSCs with in vitro-synthesized pancreatic-duodenal homebox 1 (PDX1) messenger (m)RNA into islet-like cell clusters. hUC-MSCs were confirmed by both biomarker detection and functional differentiation. In vitro-synthesized PDX1 messenger RNA can be transfected into hUC-MSCs efficiently. The upregulated expression of PDX1 protein can be detected 4 h after transfection and remains detectable for 36 h. The induction of islet-like structures was confirmed by means of morphology and dithizone staining. Reverse transcriptase-polymerase chain reaction results revealed the expression of some key pancreatic transcription factors, such as PDX1, NeuroD, NKX6.1, Glut-2 and insulin in islet-like cell clusters. Immunofluorescence analysis showed that differentiated cells express both insulin and C-peptide. Enzyme-linked immunosorbent assay analysis validated the insulin secretion of islet-like cell clusters in response to the glucose stimulation. Our results demonstrate the use of in vitro-synthesized PDX1 messenger RNA to differentiate hUC-MSCs into islet-like cells and pave the way toward the development of reprogramming and directed-differentiation methods for the expression of encoded proteins. Copyright © 2014 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

  2. Transcriptomic profiling of pancreatic alpha, beta and delta cell populations identifies delta cells as a principal target for ghrelin in mouse islets

    DEFF Research Database (Denmark)

    Adriaenssens, Alice E; Svendsen, Berit; Lam, Brian Y H

    2016-01-01

    cytometry and analysed by RNA sequencing. The role of the ghrelin receptor was validated by imaging delta cell calcium concentrations using islets with delta cell restricted expression of the calcium reporter GCaMP3, and in perfused mouse pancreases. RESULTS: A database was constructed of all genes...... expressed in alpha, beta and delta cells. The gene encoding the ghrelin receptor, Ghsr, was highlighted as being highly expressed and enriched in delta cells. Activation of the ghrelin receptor raised cytosolic calcium levels in primary pancreatic delta cells and enhanced somatostatin secretion in perfused...... pancreases, correlating with a decrease in insulin and glucagon release. The inhibition of insulin secretion by ghrelin was prevented by somatostatin receptor antagonism. CONCLUSIONS/INTERPRETATION: Our transcriptomic database of genes expressed in the principal islet cell populations will facilitate...

  3. Organ procurement organization compliance with 21 CFR 1271: a challenge for allogeneic pancreatic islet cell transplantation programs.

    Science.gov (United States)

    Winters, J L; Tran, S A; Gastineau, D A; Padley, D J; Dean, P G; Kudva, Y C

    2009-06-01

    In order to protect tissue recipients, the Food and Drug Administration drafted Title 21, Section 1271 of the Code of Federal Regulations 1271 (21 CFR 1271) to address infectious disease risk. These regulations apply to tissues but not vascularized organs. Pancreatic islet cells are regulated under 21 CFR 1271. These regulations require qualification of suppliers of critical materials and services with regard to 21 CFR 1271 compliance. As part of supplier qualification, all organ procurement organizations (OPOs) in the United States were sent a questionnaire covering the key components of these regulations. Of the 57 OPOs, 29 (51%) were in compliance based upon survey results. Twelve (21%) were not compliant in one or more areas. All indicated plans to become compliant. The remaining 15 (27%) either failed or refused to complete the survey, some indicating 21 CFR 1271 did not apply to OPOs. Using 2006 data, OPOs compliant with 21 CFR 1271 recovered 50% of the organs procured in the United States. These findings represent a challenge for allogeneic islet cell transplant programs whose raw material must comply with 21 CFR 1271. OPOs should work toward understanding and complying with 21 CFR 1271. Regulatory agencies should work toward enhancing safety of the pancreas supply by facilitating compliance through harmonization of requirements.

  4. Encapsulation of pancreatic islets for transplantation in diabetes : the untouchable islets

    NARCIS (Netherlands)

    de Vos, P; Marchetti, P

    The aim of encapsulation of pancreatic islets is to transplant in the absence of immunosuppression. It is based on the principle that transplanted tissue is protected from the host immune system by an artificial membrane. Encapsulation allows for application of insulin-secreting cells of animal or

  5. GLUT4 in the endocrine pancreas--indicating an impact in pancreatic islet cell physiology?

    Science.gov (United States)

    Bähr, I; Bazwinsky-Wutschke, I; Wolgast, S; Hofmann, K; Streck, S; Mühlbauer, E; Wedekind, D; Peschke, E

    2012-06-01

    The glucose transporter GLUT4 is well known to facilitate the transport of blood glucose into insulin-sensitive muscle and adipose tissue. In this study, molecular, immunohistochemical, and Western blot investigations revealed evidence that GLUT4 is also located in the mouse, rat, and human endocrine pancreas. In addition, high glucose decreased and insulin elevated the GLUT4 expression in pancreatic α-cells. In contrast, high glucose increased GLUT4 expression, whereas insulin led to a reduced expression level of the glucose transporter in pancreatic β-cells. In vivo experiments showed that in pancreatic tissue of type 2 diabetic rats as well as type 2 diabetic patients, the GLUT4 expression is significantly increased compared to the nondiabetic control group. Furthermore, type 1 diabetic rats exhibited reduced GLUT4 transcript levels in pancreatic tissue, whereas insulin treatment of type 1 diabetic animals enhanced the GLUT4 expression back to control levels. These data provide evidence for the existence of GLUT4 in the endocrine pancreas and indicate a physiological relevance of this glucose transporter as well as characteristic changes in diabetic disease. © Georg Thieme Verlag KG Stuttgart · New York.

  6. Can pancreatic duct-derived progenitors be a source of islet regeneration?

    International Nuclear Information System (INIS)

    Xia, Bing; Zhan, Xiao-Rong; Yi, Ran; Yang, Baofeng

    2009-01-01

    The regenerative process of the pancreas is of interest because the main pathogenesis of diabetes mellitus is an inadequate number of insulin-producing β-cells. The functional mass of β-cells is decreased in type 1 diabetes, so replacing missing β-cells or triggering their regeneration may allow for improved type 1 diabetes treatment. Therefore, expansion of the β-cell mass from endogenous sources, either in vivo or in vitro, represents an area of increasing interest. The mechanism of islet regeneration remains poorly understood, but the identification of islet progenitor sources is critical for understanding β-cell regeneration. One potential source is the islet proper, via the dedifferentiation, proliferation, and redifferentiation of facultative progenitors residing within the islet. Neogenesis, or that the new pancreatic islets can derive from progenitor cells present within the ducts has been reported, but the existence and identity of the progenitor cells have been debated. In this review, we focus on pancreatic ductal cells, which are islet progenitors capable of differentiating into islet β-cells. Islet neogenesis, seen as budding of hormone-positive cells from the ductal epithelium, is considered to be one mechanism for normal islet growth after birth and in regeneration, and has suggested the presence of pancreatic stem cells. Numerous results support the neogenesis hypothesis, the evidence for the hypothesis in the adult comes primarily from morphological studies that have in common the production of damage to all or part of the pancreas, with consequent inflammation and repair. Although numerous studies support a ductal origin for new islets after birth, lineage-tracing experiments are considered the 'gold standard' of proof. Lineage-tracing experiments show that pancreatic duct cells act as progenitors, giving rise to new islets after birth and after injury. The identification of differentiated pancreatic ductal cells as an in vivo progenitor for

  7. Can pancreatic duct-derived progenitors be a source of islet regeneration?

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Bing [Department of Endocrinology, First Hospital of Harbin Medical University, Harbin, Hei Long Jiang Province 150001 (China); Zhan, Xiao-Rong, E-mail: xiaorongzhan@sina.com [Department of Endocrinology, First Hospital of Harbin Medical University, Harbin, Hei Long Jiang Province 150001 (China); Yi, Ran [Department of Endocrinology, First Hospital of Harbin Medical University, Harbin, Hei Long Jiang Province 150001 (China); Yang, Baofeng [Department of Pharmacology, State Key Laboratory of Biomedicine and Pharmacology, Harbin Medical University, Harbin, Hei Long Jiang Province 150001 (China)

    2009-06-12

    The regenerative process of the pancreas is of interest because the main pathogenesis of diabetes mellitus is an inadequate number of insulin-producing {beta}-cells. The functional mass of {beta}-cells is decreased in type 1 diabetes, so replacing missing {beta}-cells or triggering their regeneration may allow for improved type 1 diabetes treatment. Therefore, expansion of the {beta}-cell mass from endogenous sources, either in vivo or in vitro, represents an area of increasing interest. The mechanism of islet regeneration remains poorly understood, but the identification of islet progenitor sources is critical for understanding {beta}-cell regeneration. One potential source is the islet proper, via the dedifferentiation, proliferation, and redifferentiation of facultative progenitors residing within the islet. Neogenesis, or that the new pancreatic islets can derive from progenitor cells present within the ducts has been reported, but the existence and identity of the progenitor cells have been debated. In this review, we focus on pancreatic ductal cells, which are islet progenitors capable of differentiating into islet {beta}-cells. Islet neogenesis, seen as budding of hormone-positive cells from the ductal epithelium, is considered to be one mechanism for normal islet growth after birth and in regeneration, and has suggested the presence of pancreatic stem cells. Numerous results support the neogenesis hypothesis, the evidence for the hypothesis in the adult comes primarily from morphological studies that have in common the production of damage to all or part of the pancreas, with consequent inflammation and repair. Although numerous studies support a ductal origin for new islets after birth, lineage-tracing experiments are considered the 'gold standard' of proof. Lineage-tracing experiments show that pancreatic duct cells act as progenitors, giving rise to new islets after birth and after injury. The identification of differentiated pancreatic ductal

  8. Transcriptional Regulation of Chemokine Genes: A Link to Pancreatic Islet Inflammation?

    Directory of Open Access Journals (Sweden)

    Susan J. Burke

    2015-05-01

    Full Text Available Enhanced expression of chemotactic cytokines (aka chemokines within pancreatic islets likely contributes to islet inflammation by regulating the recruitment and activation of various leukocyte populations, including macrophages, neutrophils, and T-lymphocytes. Because of the powerful actions of these chemokines, precise transcriptional control is required. In this review, we highlight what is known about the signals and mechanisms that govern the transcription of genes encoding specific chemokine proteins in pancreatic islet β-cells, which include contributions from the NF-κB and STAT1 pathways. We further discuss increased chemokine expression in pancreatic islets during autoimmune-mediated and obesity-related development of diabetes.

  9. A New Method for Generating Insulin-Secreting Cells from Human Pancreatic Epithelial Cells After Islet Isolation Transformed by NeuroD1

    Science.gov (United States)

    Shimoda, Masayuki; Chen, Shuyuan; Noguchi, Hirofumi; Takita, Morihito; Sugimoto, Koji; Itoh, Takeshi; Chujo, Daisuke; Iwahashi, Shuichi; Naziruddin, Bashoo; Levy, Marlon F.

    2014-01-01

    Abstract The generation of insulin-secreting cells from nonendocrine pancreatic epithelial cells (NEPEC) has been demonstrated for potential clinical use in the treatment of diabetes. However, previous methods either had limited efficacy or required viral vectors, which hinder clinical application. In this study, we aimed to establish an efficient method of insulin-secreting cell generation from NEPEC without viral vectors. We used nonislet fractions from both research-grade human pancreata from brain-dead donors and clinical pancreata after total pancreatectomy with autologous islet transplantation to treat chronic pancreatitis. It is of note that a few islets could be mingled in the nonislet fractions, but their influence could be limited. The NeuroD1 gene was induced into NEPEC using an effective triple lipofection method without viral vectors to generate insulin-secreting cells. The differentiation was promoted by adding a growth factor cocktail into the culture medium. Using the research-grade human pancreata, the effective method showed high efficacy in the differentiation of NEPEC into insulin-positive cells that secreted insulin in response to a glucose challenge and improved diabetes after being transplanted into diabetic athymic mice. Using the clinical pancreata, similar efficacy was obtained, even though those pancreata suffered chronic pancreatitis. In conclusion, our effective differentiation protocol with triple lipofection method enabled us to achieve very efficient insulin-secreting cell generation from human NEPEC without viral vectors. This method offers the potential for supplemental insulin-secreting cell transplantation for both allogeneic and autologous islet transplantation. PMID:24845703

  10. Optimal formation of genetically modified and functional pancreatic islet spheroids by using hanging-drop strategy.

    Science.gov (United States)

    Kim, H J; Alam, Z; Hwang, J W; Hwang, Y H; Kim, M J; Yoon, S; Byun, Y; Lee, D Y

    2013-03-01

    Rejection and hypoxia are important factors causing islet loss at an early stage after pancreatic islet transplantation. Recently, islets have been dissociated into single cells for reaggregation into so-called islet spheroids. Herein, we used a hanging-drop strategy to form islet spheroids to achieve functional equivalence to intact islets. To obtain single islet cells, we dissociated islets with trypsin-EDTA digestion for 10 minutes. To obtain spheroids, we dropped various numbers of single cells (125, 250, or 500 cells/30 μL drop) onto a Petri dish, that was inverted for incubation in humidified air containing 5% CO(2) at 37 °C for 7 days. The aggregated spheroids in the droplets were harvested for further culture. The size of the aggregated islet spheroids depended on the number of single cells (125-500 cells/30 μL droplet). Their morphology was similar to that of intact islets without any cellular damage. When treated with various concentrations of glucose to evaluate responsiveness, their glucose-mediated stimulation index value was similar to that of intact islets, an observation that was attributed to strong cell-to-cell interactions in islet spheroids. However, islet spheroids aggregated in general culture dishes showed abnormal glucose responsiveness owing to weak cell-to-cell interactions. Cell-to-cell interactions in islet spheroids were confirmed with an anti-connexin-36 monoclonal antibody. Finally, nonviral poly(ethylene imine)-mediated interleukin-10 cytokine gene delivered beforehand into dissociated single cells before formation of islet spheroids increased the gene transfection efficacy and interleukin-10 secretion from islet spheroids >4-fold compared with intact islets. These results demonstrated the potential application of genetically modified, functional islet spheroids with of controlled size and morphology using an hanging-drop technique. Copyright © 2013 Elsevier Inc. All rights reserved.

  11. Influence of High Aspect Ratio Vessel Cell Culture on TNF-Alpha, Insulin Secretion and Glucose Homeostasis in Pancreatic Islets of Langerhans from Wistar Furth Rats

    Science.gov (United States)

    Tobin, Brian W.a; Leeper-Woodford, Sandra K.

    1999-01-01

    The present studies were carried out to determine the influence of a ground based microgravity paradigm, utilizing the High Aspect Ratio Vessel (HARV) cell culture upon lipopolysaccharide (LPS) stimulated tumor necrosis factor alpha (TNF-alpha) production of pancreatic islets of Langerhans. An additional aim was to elucidate alterations in insulin secretion and glucose utilization using the HARV low shear, gravity averaged vector, cell culture technique. Islets were isolated (1726 +/- 117, 150 micron islet equivalent units) from Wistar Furth rats and assigned to four treatment groups: 1) HARV, 2) HARV plus LPS, 3) static culture, 4) static culture plus LPS. Following 48 hours of culture, insulin concentration was increased in both HARV and static cultures (palpha (L929 cytotoxicity assay) and was measured at selected time points for 48 hours. TNF-alpha was significantly increased in LPS-induced HARV and static cultures, yet the increase was more pronounced in the static culture group (palpha is associated with a decreased insulin secretion is intriguing, both as it relates to in-flight investigations, and as it may provide insight into the pathophysiology of Type I and Type 11 diabetes. Glucose concentration in islet medium was lesser throughout the experiment in static cultures, suggesting a decreased reliance upon glucose as a metabolic substrate in the islets cultured in HARVS. In conclusion, the present studies demonstrate alterations in LPS induced TNF-alpha production of pancreatic islets of Langerhans, favoring a lesser TNF production in the microgravity HARV paradigm. Additionally, alterations in fuel homeostasis may be promulgated by HARV culture. The clinical and physiological significance of these observations remains to be determined.

  12. Glucose-Dependent Insulin Secretion in Pancreatic β-Cell Islets from Male Rats Requires Ca2+ Release via ROS-Stimulated Ryanodine Receptors.

    Directory of Open Access Journals (Sweden)

    Paola Llanos

    Full Text Available Glucose-stimulated insulin secretion (GSIS from pancreatic β-cells requires an increase in intracellular free Ca2+ concentration ([Ca2+]. Glucose uptake into β-cells promotes Ca2+ influx and reactive oxygen species (ROS generation. In other cell types, Ca2+ and ROS jointly induce Ca2+ release mediated by ryanodine receptor (RyR channels. Therefore, we explored here if RyR-mediated Ca2+ release contributes to GSIS in β-cell islets isolated from male rats. Stimulatory glucose increased islet insulin secretion, and promoted ROS generation in islets and dissociated β-cells. Conventional PCR assays and immunostaining confirmed that β-cells express RyR2, the cardiac RyR isoform. Extended incubation of β-cell islets with inhibitory ryanodine suppressed GSIS; so did the antioxidant N-acetyl cysteine (NAC, which also decreased insulin secretion induced by glucose plus caffeine. Inhibitory ryanodine or NAC did not affect insulin secretion induced by glucose plus carbachol, which engages inositol 1,4,5-trisphosphate receptors. Incubation of islets with H2O2 in basal glucose increased insulin secretion 2-fold. Inhibitory ryanodine significantly decreased H2O2-stimulated insulin secretion and prevented the 4.5-fold increase of cytoplasmic [Ca2+] produced by incubation of dissociated β-cells with H2O2. Addition of stimulatory glucose or H2O2 (in basal glucose to β-cells disaggregated from islets increased RyR2 S-glutathionylation to similar levels, measured by a proximity ligation assay; in contrast, NAC significantly reduced the RyR2 S-glutathionylation increase produced by stimulatory glucose. We propose that RyR2-mediated Ca2+ release, induced by the concomitant increases in [Ca2+] and ROS produced by stimulatory glucose, is an essential step in GSIS.

  13. Clock-controlled output gene Dbp is a regulator of Arnt/Hif-1β gene expression in pancreatic islet β-cells

    International Nuclear Information System (INIS)

    Nakabayashi, Hiroko; Ohta, Yasuharu; Yamamoto, Masayoshi; Susuki, Yosuke; Taguchi, Akihiko; Tanabe, Katsuya; Kondo, Manabu; Hatanaka, Masayuki; Nagao, Yuko; Tanizawa, Yukio

    2013-01-01

    Highlights: •Arnt mRNA expressed in a circadian manner in mouse pancreatic islets. •Expressions of Dbp and Arnt damped in the islets of a diabetic model mouse. •DBP and E4BP4 regulate Arnt promoter activity by direct binding. •Arnt may have a role in connecting circadian rhythm and metabolism. -- Abstract: Aryl hydrocarbon receptor nuclear translocator (ARNT)/hypoxia inducible factor-1β (HIF-1β) has emerged as a potential determinant of pancreatic β-cell dysfunction and type 2 diabetes in humans. An 82% reduction in Arnt expression was observed in islets from type 2 diabetic donors as compared to non-diabetic donors. However, few regulators of Arnt expression have been identified. Meanwhile, disruption of the clock components CLOCK and BMAL1 is known to result in hypoinsulinemia and diabetes, but the molecular details remain unclear. In this study, we identified a novel molecular connection between Arnt and two clock-controlled output genes, albumin D-element binding protein (Dbp) and E4 binding protein 4 (E4bp4). By conducting gene expression studies using the islets of Wfs1 −/− A y /a mice that develop severe diabetes due to β-cell apoptosis, we demonstrated clock-related gene expressions to be altered in the diabetic mice. Dbp mRNA decreased by 50%, E4bp4 mRNA increased by 50%, and Arnt mRNA decreased by 30% at Zeitgever Time (ZT) 12. Mouse pancreatic islets exhibited oscillations of clock gene expressions. E4BP4, a D-box negative regulator, oscillated anti-phase to DBP, a D-box positive regulator. We also found low-amplitude circadian expression of Arnt mRNA, which peaked at ZT4. Over-expression of DBP raised both mRNA and protein levels of ARNT in HEK293 and MIN6 cell lines. Arnt promoter-driven luciferase reporter assay in MIN6 cells revealed that DBP increased Arnt promoter activity by 2.5-fold and that E4BP4 competitively inhibited its activation. In addition, on ChIP assay, DBP and E4BP4 directly bound to D-box elements within the Arnt

  14. Clock-controlled output gene Dbp is a regulator of Arnt/Hif-1β gene expression in pancreatic islet β-cells

    Energy Technology Data Exchange (ETDEWEB)

    Nakabayashi, Hiroko; Ohta, Yasuharu, E-mail: yohta@yamaguchi-u.ac.jp; Yamamoto, Masayoshi; Susuki, Yosuke; Taguchi, Akihiko; Tanabe, Katsuya; Kondo, Manabu; Hatanaka, Masayuki; Nagao, Yuko; Tanizawa, Yukio, E-mail: tanizawa@yamaguchi-u.ac.jp

    2013-05-03

    Highlights: •Arnt mRNA expressed in a circadian manner in mouse pancreatic islets. •Expressions of Dbp and Arnt damped in the islets of a diabetic model mouse. •DBP and E4BP4 regulate Arnt promoter activity by direct binding. •Arnt may have a role in connecting circadian rhythm and metabolism. -- Abstract: Aryl hydrocarbon receptor nuclear translocator (ARNT)/hypoxia inducible factor-1β (HIF-1β) has emerged as a potential determinant of pancreatic β-cell dysfunction and type 2 diabetes in humans. An 82% reduction in Arnt expression was observed in islets from type 2 diabetic donors as compared to non-diabetic donors. However, few regulators of Arnt expression have been identified. Meanwhile, disruption of the clock components CLOCK and BMAL1 is known to result in hypoinsulinemia and diabetes, but the molecular details remain unclear. In this study, we identified a novel molecular connection between Arnt and two clock-controlled output genes, albumin D-element binding protein (Dbp) and E4 binding protein 4 (E4bp4). By conducting gene expression studies using the islets of Wfs1{sup −/−} A{sup y}/a mice that develop severe diabetes due to β-cell apoptosis, we demonstrated clock-related gene expressions to be altered in the diabetic mice. Dbp mRNA decreased by 50%, E4bp4 mRNA increased by 50%, and Arnt mRNA decreased by 30% at Zeitgever Time (ZT) 12. Mouse pancreatic islets exhibited oscillations of clock gene expressions. E4BP4, a D-box negative regulator, oscillated anti-phase to DBP, a D-box positive regulator. We also found low-amplitude circadian expression of Arnt mRNA, which peaked at ZT4. Over-expression of DBP raised both mRNA and protein levels of ARNT in HEK293 and MIN6 cell lines. Arnt promoter-driven luciferase reporter assay in MIN6 cells revealed that DBP increased Arnt promoter activity by 2.5-fold and that E4BP4 competitively inhibited its activation. In addition, on ChIP assay, DBP and E4BP4 directly bound to D-box elements within the

  15. Inhibition of carbachol-induced formation of inositolphosphates in isolated pancreatic islets

    DEFF Research Database (Denmark)

    Kardasz, A.M.J.; Capito, Kirsten; Hansen, Svend Erik

    1991-01-01

    Medicinsk biokemi, feed-back inhibition, phospholipase C, pancreatic islets, Calcium, proteinkinase C......Medicinsk biokemi, feed-back inhibition, phospholipase C, pancreatic islets, Calcium, proteinkinase C...

  16. Origin of induced pancreatic islet tumors: a radioautographic study

    International Nuclear Information System (INIS)

    Michels, J.E.; Bauer, G.E.; Dixit, P.K.

    1987-01-01

    Endocrine tumors of the pancreas are induced in a high percentage of young rats by injections of streptozotocin and nicotinamide (SZ/NA). Benign tumors first appear 20 to 36 weeks after drug injections. To determine the possible site of their origin, the incorporation of [ 3 H]thymidine into islets, ducts, acini, microtumors, and gross tumors was examined by radioautography of histologic sections at 1 to 36 weeks after drug injection. Drug treatment led to early (1- to 6-week) increases in nuclear 3 H labeling of exocrine pancreatic structures (ductal and acinar cells), which may involve DNA repair processes. A secondary increase in labeling of duct cells during the period of tumor emergence supports the assumption that SZ/NA-induced tumors are of ductal origin. Microtumors and gross tumors also exhibited markedly elevated rates of [ 3 H]thymidine incorporation compared to control islets. Nontumorous islet tissue, which exhibited a gradual decrease in volume due to B-cell destruction by the drug injection, showed about 10-fold higher 3 H labeling than islets of controls at all time points. The results suggest that in addition to ductal precursors, islets that survive SZ/NA-induced injury may also provide sites of focal endocrine cell differentiation to tumor tissue. Once established, both microtumors and gross tumors continue to grow by accelerated cell division

  17. Wave-Block Due to a Threshold Gradient Underlies Limited Coordination in Pancreatic Islets

    DEFF Research Database (Denmark)

    Pedersen, Morten Gram; Sørensen, Mads Peter

    2008-01-01

    Two models for coupled pancreatic β cells are used to investigate excited wave propagation in spatially inhomogeneous islets of Langerhans. The application concerns spatial variation of glucose concentration across the islet. A comprehensive model of coupled cells shows that wave blocking occurs ...

  18. The role of endothelial cells on islet function and revascularization after islet transplantation.

    Science.gov (United States)

    Del Toro-Arreola, Alicia; Robles-Murillo, Ana Karina; Daneri-Navarro, Adrian; Rivas-Carrillo, Jorge David

    2016-01-02

    Islet transplantation has become a widely accepted therapeutic option for selected patients with type 1 diabetes mellitus. However, in order to achieve insulin independence a great number of islets are often pooled from 2 to 4 pancreata donors. Mostly, it is due to the massive loss of islets immediately after transplant. The endothelium plays a key role in the function of native islets and during the revascularization process after islet transplantation. However, if a delayed revascularization occurs, even the remaining islets will also undergo to cell death and late graft dysfunction. Therefore, it is essential to understand how the signals are released from endothelial cells, which might regulate both differentiation of pancreatic progenitors and thereby maintenance of the graft function. New strategies to facilitate islet engraftment and a prompt revascularization could be designed to intervene and might lead to improve future results of islet transplantation.

  19. Histomorphological and morphometric studies of the pancreatic islet cells of diabetic rats treated with aqueous extracts of Momordica charantia (karela fruits

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    Mohammad Aftab Hossain

    2014-09-01

    Full Text Available Objective: To investigate the effect of aqueous extract of Momordica charantia (karela (M. charantia fruits on blood glucose level, pancreatic weight changes and histopathology of pancreatic changes in the streptozotocin (STZ induced diabetic rats. Methods: Thirty-six albino rats were used in the experiment; diabetes mellitus was induced in 30 adult albino rats, using intraperitoneal injection of 55 mg/kg STZ. Six non diabetic rats remained as control (T1 . The diabetic rats were randomly assigned into five equal groups: diabetic control (T2 without any treatment, groups T3, T4, T5 and T6 were treated with aqueous extract of karela fruits daily at a doses of 250, 500 and 750 mg/kg and glibenclamide (5 mg/kg up to 90 d, respectively. At Day 90, all rats were sacrificed, the pancreases of the rats were excised and processed. Results: The results of this study indicate that aqueous extract of M. charantia fruits was able to reduce blood glucose level significantly compared with the diabetic control group (P<0.01. Histopathologically, STZ resulted severe necrotic changes in pancreatic islets. Tissues sections of pancreas in the treated groups showed regeneration of β cells and increased size of pancreatic islets. Conclusions: The present study suggests that oral feeding of M. charantia fruit juice has a significant anti-hyperglycemic effect and may have a role in the regeneration of the β cells in STZ diabetic rats.

  20. Mitochondrial oxidative stress contributes differently to rat pancreatic islet cell apoptosis and insulin secretory defects after prolonged culture in a low non-stimulating glucose concentration.

    Science.gov (United States)

    Roma, L P; Pascal, S M; Duprez, J; Jonas, J-C

    2012-08-01

    Pancreatic beta cells chronically exposed to low glucose concentrations show signs of oxidative stress, loss of glucose-stimulated insulin secretion (GSIS) and increased apoptosis. Our aim was to confirm the role of mitochondrial oxidative stress in rat islet cell apoptosis under these culture conditions and to evaluate whether its reduction similarly improves survival and GSIS. Apoptosis, oxidative stress-response gene mRNA expression and glucose-induced stimulation of mitochondrial metabolism, intracellular Ca(2+) concentration and insulin secretion were measured in male Wistar rat islets cultured for 1 week in RPMI medium containing 5-10 mmol/l glucose with or without manganese(III)tetrakis(4-benzoic acid)porphyrin (MnTBAP) or N-acetyl-L-: cysteine (NAC). Oxidative stress was measured in islet cell clusters cultured under similar conditions using cytosolic and mitochondrial redox-sensitive green fluorescent protein (roGFP1/mt-roGFP1). Prolonged culture in 5 vs 10 mmol/l glucose increased mt-roGFP1 (but not roGFP1) oxidation followed by beta cell apoptosis and loss of GSIS resulting from reduced insulin content, mitochondrial metabolism, Ca(2+) influx and Ca(2+)-induced secretion. Tolbutamide-induced, but not high K(+)-induced, Ca(2+) influx was also suppressed. Under these conditions, MnTBAP, but not NAC, triggered parallel ~50-70% reductions in mt-roGFP1 oxidation and beta cell apoptosis, but failed to protect against the loss of GSIS despite significant improvement in glucose-induced and tolbutamide-induced Ca(2+) influx. Mitochondrial oxidative stress contributes differently to rat pancreatic islet cell apoptosis and insulin secretory defects during culture in a low glucose concentration. Thus, targeting beta cell survival may not be sufficient to restore insulin secretion when beta cells suffer from prolonged mitochondrial oxidative stress, e.g. in the context of reduced glucose metabolism.

  1. RNA-seq methods for identifying differentially expressed gene in human pancreatic islet cells treated with pro-inflammatory cytokines.

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    Li, Bo; Bi, Chang Long; Lang, Ning; Li, Yu Ze; Xu, Chao; Zhang, Ying Qi; Zhai, Ai Xia; Cheng, Zhi Feng

    2014-01-01

    Type 1 diabetes is a chronic autoimmune disease in which pancreatic beta cells are killed by the infiltrating immune cells as well as the cytokines released by these cells. Many studies indicate that inflammatory mediators have an essential role in this disease. In the present study, we profiled the transcriptome in human islets of langerhans under control conditions or following exposure to the pro-inflammatory cytokines based on the RNA sequencing dataset downloaded from SRA database. After filtered the low-quality ones, the RNA readers was aligned to human genome hg19 by TopHat and then assembled by Cufflinks. The expression value of each transcript was calculated and consequently differentially expressed genes were screened out. Finally, a total of 63 differentially expressed genes were identified including 60 up-regulated and three down-regulated genes. GBP5 and CXCL9 stood out as the top two most up-regulated genes in cytokines treated samples with the log2 fold change of 12.208 and 10.901, respectively. Meanwhile, PTF1A and REG3G were identified as the top two most down-regulated genes with the log2 fold change of -3.759 and -3.606, respectively. Of note, we also found 262 lncRNAs (long non-coding RNA), 177 of which were inferred as novel lncRNAs. Further in-depth follow-up analysis of the transcriptional regulation reported in this study may shed light on the specific function of these lncRNA.

  2. Adult Human Pancreatic Islet Beta-Cells Display Limited Turnover and Long Lifespan as Determined by In-Vivo Thymidine Analog Incorporation and Radiocarbon Dating

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    Perl, S; Kushner, J A; Buchholz, B A; Meeker, A K; Stein, G M; Hsieh, M; Kirby, M; Pechhold, S; Liu, E H; Harlan, D M; Tisdale, J F

    2010-03-15

    Diabetes mellitus results from an absolute or relative deficiency of insulin producing pancreatic beta-cells. The adult human beta-cell's turnover rate remains unknown. We employed novel techniques to examine adult human islet beta-cell turnover and longevity in vivo. Subjects enrolled in NIH clinical trials received thymidine analogues [iododeoxyuridine (IdU) or bromodeoxyuridine (BrdU)] 8-days to 4-years prior to death. Archival autopsy samples from ten patients (aged 17-74 years) were employed to assess beta-cell turnover by scoring nuclear analog labeling within insulin staining cells. Human adult beta-cell longevity was determined by estimating the cells genomic DNA integration of atmospheric carbon-14 ({sup 14}C). DNA was purified from pancreatic islets isolated from cadaveric donors; whole islet prep DNA was obtained from a 15 year old donor, and purified beta-cell DNA was obtained from two donors (age 48 and 80 years). {sup 14}C levels were then determined using accelerator mass spectrometry (AMS). Cellular 'birth date' was determined by comparing the subject's DNA {sup 14}C content relative to a well-established {sup 14}C atmospheric prevalence curve. In the two subjects less than age 20 years, 1-2% of the beta-cell nuclei co-stained for BrdU/IdU. No beta-cell nuclei co-stained in the eight patients more than 30 years old. Consistent with the BrdU/IdU turnover data, beta-cell DNA {sup 14}C content indicated the cells 'birth date' occurred within the subject's first 30 years of life. Under typical circumstances, adult human beta-cells and their cellular precursors are established by young adulthood.

  3. Impact of islet size on pancreatic islet transplantation and potential interventions to improve outcome.

    Science.gov (United States)

    Zorzi, Daria; Phan, Tammy; Sequi, Marco; Lin, Yong; Freeman, Daniel H; Cicalese, Luca; Rastellini, Cristiana

    2015-01-01

    Better results have been recently reported in clinical pancreatic islet transplantation (ITX) due mostly to improved isolation techniques and immunosuppression; however, some limitations still exist. It is known that following transplantation, 30% to 60% of the islets are lost. In our study, we have investigated 1) the role of size as a factor affecting islet engraftment and 2) potential procedural manipulations to increase the number of smaller functional islets that can be transplanted. C57/BL10 mice were used as donors and recipients in a syngeneic islet transplant model. Isolated islets were divided by size (large, >300 μm; medium 150-300 μm; small, <150 μm). Each size was transplanted in chemically induced diabetic mice as full (600 IEQ), suboptimal (400 IEQ), and marginal mass (200 IEQ). Control animals received all size islets. Engraftment was defined as reversal of diabetes by day 7 posttransplantation. When the superiority of smaller islets was observed, strategies of overdigestion and fragmentation were adopted during islet isolation in the attempt to reduce islet size and improve engraftment. Smaller islets were significantly superior in engraftment compared to medium, large, and control (all sizes) groups. This was more evident when marginal mass data were compared. In all masses, success decreased as islet size increased. Once islets were engrafted, functionality was not affected by size. When larger islets were fragmented, a significant decrease in islet functionality was observed. On the contrary, if pancreata were slightly overdigested, although not as successful as small naive islets, an increase in engraftment was observed when compared to the control group. In conclusion, smaller islets are superior in engraftment following islet transplantation. Fragmentation has a deleterious effect on islet engraftment. Islet isolations can be performed by reducing islet size with slight overdigestion, and it can be safely adopted to improve clinical

  4. Facilitated Engraftment of Isolated Islets Coated With Expanded Vascular Endothelial Cells for Islet Transplantation.

    Science.gov (United States)

    Barba-Gutierrez, D Alonso; Daneri-Navarro, A; Villagomez-Mendez, J Jesus Alejandro; Kanamune, J; Robles-Murillo, A Karina; Sanchez-Enriquez, S; Villafan-Bernal, J Rafael; Rivas-Carrillo, J D

    2016-03-01

    Diabetes is complex disease, which involves primary metabolic changes followed by immunological and vascular pathophysiological adjustments. However, it is mostly characterized by an unbalanced decreased number of the β-cells unable to maintain the metabolic requirements and failure to further regenerate newly functional pancreatic islets. The objective of this study was to analyze the properties of the endothelial cells to facilitate the islet cells engraftment after islet transplantation. We devised a co-cultured engineer system to coat isolated islets with vascular endothelial cells. To assess the cell integration of cell-engineered islets, we stained them for endothelial marker CD31 and nuclei counterstained with DAPI dye. We comparatively performed islet transplantations into streptozotocin-induced diabetic mice and recovered the islet grafts for morphometric analyses on days 3, 7, 10, and 30. Blood glucose levels were measured continuously after islet transplantation to monitor the functional engraftment and capacity to achieve metabolic control. Cell-engineered islets showed a well-defined rounded shape after co-culture when compared with native isolated islets. Furthermore, the number of CD31-positive cells layered on the islet surface showed a direct proportion with engraftment capacities and less TUNEL-positive cells on days 3 and 7 after transplantation. We observed that vascular endothelial cells could be functional integrated into isolated islets. We also found that islets that are coated with vascular endothelial cells increased their capacity to engraft. These findings indicate that islets coated with endothelial cells have a greater capacity of engraftment and thus establish a definitely vascular network to support the metabolic requirements. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Clinical Allogeneic and Autologous Islet Cell Transplantation: Update

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    Shinichi Matsumoto

    2011-06-01

    Full Text Available Islet cell transplantation is categorized as a β-cell replacement therapy for diabetic patients who lack the ability to secrete insulin. Allogeneic islet cell transplantation is for the treatment of type 1 diabetes, and autologous islet cell transplantation is for the prevention of surgical diabetes after a total pancreatectomy. The issues of allogeneic islet cell transplantation include poor efficacy of islet isolation, the need for multiple donor pancreata, difficulty maintaining insulin independence and undesirable side effects of immunosuppressive drugs. Those issues have been solved step by step and allogeneic islet cell transplantation is almost ready to be the standard therapy. The donor shortage will be the next issue and marginal and/or living donor islet cell transplantation might alleviate the issue. Xeno-islet cell transplantation, β-cell regeneration from human stem cells and gene induction of the naïve pancreas represent the next generation of β-cell replacement therapy. Autologous islet cell transplantation after total pancreatectomy for the treatment of chronic pancreatitis with severe abdominal pain is the standard therapy, even though only limited centers are able to perform this treatment. Remote center autologous islet cell transplantation is an attractive option for hospitals performing total pancreatectomies without the proper islet isolation facilities.

  6. CT features of nonfunctioning islet cell carcinoma

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    Eelkema, E.A.; Stephens, D.H.; Ward, E.M.; Sheedy, P.F. II

    1984-11-01

    To determine the computed tomographic (CT) characteristics of nonfunctioning islet cell carcinoma of the pancreas, the CT scans of 27 patients with that disease were reviewed. The pancreatic tumor was identified as a mass in 26 patients (96%) Of the 25 tumors evaluated with contrast enhancement, 20 became partially diffusely hyperdense relative to nearby normal pancreatic tissue. Hepatic metastases were identified in 15 patients (56%), regional lymphadenopathy in 10 (37%), atrophy of the gland proximal to the tumor in six (22%), dilatation of the biliary ducts in five (19%), and dilatation of the pancreatic duct in four (15%). The CT appearances of the nonfunctioning islet cell tumors were compared with those of 100 ordinary (ductal) pancreatic adenocarcinomas. Although the two types of tumors were sometimes indistinguishable, features found to be more characteristic of islet cell carcinoma included a pancreatic mass of unusually large size, calcification within the tumor, and contrast enhancement of either the primary tumor or hepatic metastases. Involvement of the celiac axis or proximal superior mesenteric artery was limited to ductal carcinoma.

  7. Sympathetic Innervation during Development Is Necessary for Pancreatic Islet Architecture and Functional Maturation

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    Philip Borden

    2013-07-01

    Full Text Available Sympathetic neurons depend on target-derived neurotrophic cues to control their survival and growth. However, whether sympathetic innervation contributes reciprocally to the development of target tissues is less clear. Here, we report that sympathetic innervation is necessary for the formation of the pancreatic islets of Langerhans and for their functional maturation. Genetic or pharmacological ablation of sympathetic innervation during development resulted in altered islet architecture, reduced insulin secretion, and impaired glucose tolerance in mice. Similar defects were observed with pharmacological blockade of β-adrenergic signaling. Conversely, the administration of a β-adrenergic agonist restored islet morphology and glucose tolerance in deinnervated animals. Furthermore, in neuron-islet cocultures, sympathetic neurons promoted islet cell migration in a β-adrenergic-dependent manner. This study reveals that islet architecture requires extrinsic inductive cues from neighboring tissues such as sympathetic nerves and suggests that early perturbations in sympathetic innervation might underlie metabolic disorders.

  8. Antibody Response to Serpin B13 Induces Adaptive Changes in Mouse Pancreatic Islets and Slows Down the Decline in the Residual Beta Cell Function in Children with Recent Onset of Type 1 Diabetes Mellitus.

    Science.gov (United States)

    Kryvalap, Yury; Lo, Chi-Wen; Manuylova, Ekaterina; Baldzizhar, Raman; Jospe, Nicholas; Czyzyk, Jan

    2016-01-01

    Type 1 diabetes mellitus (T1D) is characterized by a heightened antibody (Ab) response to pancreatic islet self-antigens, which is a biomarker of progressive islet pathology. We recently identified a novel antibody to clade B serpin that reduces islet-associated T cell accumulation and is linked to the delayed onset of T1D. As natural immunity to clade B arises early in life, we hypothesized that it may influence islet development during that time. To test this possibility healthy young Balb/c male mice were injected with serpin B13 mAb or IgG control and examined for the number and cellularity of pancreatic islets by immunofluorescence and FACS. Beta cell proliferation was assessed by measuring nucleotide analog 5-ethynyl-2'-deoxyuridine (5-EdU) incorporation into the DNA and islet Reg gene expression was measured by real time PCR. Human studies involved measuring anti-serpin B13 autoantibodies by Luminex. We found that injecting anti-serpin B13 monoclonal Ab enhanced beta cell proliferation and Reg gene expression, induced the generation of ∼80 pancreatic islets per animal, and ultimately led to increase in the beta cell mass. These findings are relevant to human T1D because our analysis of subjects just diagnosed with T1D revealed an association between baseline anti-serpin activity and slower residual beta cell function decline in the first year after the onset of diabetes. Our findings reveal a new role for the anti-serpin immunological response in promoting adaptive changes in the endocrine pancreas and suggests that enhancement of this response could potentially help impede the progression of T1D in humans. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  9. IL-10 Induction from Implants Delivering Pancreatic Islets and Hyaluronan

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    Paul L. Bollyky

    2013-01-01

    Full Text Available Local induction of pro-tolerogenic cytokines, such as IL-10, is an appealing strategy to help facilitate transplantation of islets and other tissues. Here, we describe a pair of implantable devices that capitalize on our recent finding that hyaluronan (HA promotes IL-10 production by activated T cells. The first device is an injectable hydrogel made of crosslinked HA and heparan sulfate loaded with anti-CD3/anti-CD28 antibodies and IL-2. T cells embedded within this hydrogel prior to polymerization go on to produce IL-10 in vivo. The second device is a bioengineered implant consisting of a polyvinyl alcohol sponge scaffold, supportive collagen hydrogel, and alginate spheres mediating sustained release of HA in fluid form. Pancreatic islets that expressed ovalbumin (OVA antigen were implanted within this device for 14 days into immunodeficient mice that received OVA-specific DO.11.10 T cells and a subsequent immunization with OVA peptide. Splenocytes harvested from these mice produced IL-10 upon re-challenge with OVA or anti-CD3 antibodies. Both of these devices represent model systems that will be used, in future studies, to further evaluate IL-10 induction by HA, with the objective of improving the survival and function of transplanted islets in the setting of autoimmune (type 1 diabetes.

  10. PDX-1 Is a Therapeutic Target for Pancreatic Cancer, Insulinoma and Islet Neoplasia Using a Novel RNA Interference Platform

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    Liu, Shi-He; Rao, Donald D.; Nemunaitis, John; Senzer, Neil; Zhou, Guisheng; Dawson, David; Gingras, Marie-Claude; Wang, Zhaohui; Gibbs, Richard; Norman, Michael; Templeton, Nancy S.; DeMayo, Francesco J.; O'Malley, Bert; Sanchez, Robbi; Fisher, William E.; Brunicardi, F. Charles

    2012-01-01

    Pancreatic and duodenal homeobox-1 (PDX-1) is a transcription factor that regulates insulin expression and islet maintenance in the adult pancreas. Our recent studies demonstrate that PDX-1 is an oncogene for pancreatic cancer and is overexpressed in pancreatic cancer. The purpose of this study was to demonstrate that PDX-1 is a therapeutic target for both hormonal symptoms and tumor volume in mouse models of pancreatic cancer, insulinoma and islet neoplasia. Immunohistochemistry of human pancreatic and islet neoplasia specimens revealed marked PDX-1 overexpression, suggesting PDX-1 as a “drugable” target within these diseases. To do so, a novel RNA interference effector platform, bifunctional shRNAPDX-1, was developed and studied in mouse and human cell lines as well as in mouse models of pancreatic cancer, insulinoma and islet neoplasia. Systemic delivery of bi-shRNAhumanPDX-1 lipoplexes resulted in marked reduction of tumor volume and improved survival in a human pancreatic cancer xenograft mouse model. bi-shRNAmousePDX-1 lipoplexes prevented death from hyperinsulinemia and hypoglycemia in an insulinoma mouse model. shRNAmousePDX-1 lipoplexes reversed hyperinsulinemia and hypoglycemia in an immune-competent mouse model of islet neoplasia. PDX-1 was overexpressed in pancreatic neuroendocrine tumors and nesidioblastosis. These data demonstrate that PDX-1 RNAi therapy controls hormonal symptoms and tumor volume in mouse models of pancreatic cancer, insulinoma and islet neoplasia, therefore, PDX-1 is a potential therapeutic target for these pancreatic diseases. PMID:22905092

  11. Isolation of Human Islets for Autologous Islet Transplantation in Children and Adolescents with Chronic Pancreatitis

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    Rita Bottino

    2012-01-01

    Full Text Available Chronic pancreatitis is an inflammatory disease of the pancreas that causes permanent changes in the function and structure of the pancreas. It is most commonly a complication of cystic fibrosis or due to a genetic predisposition. Chronic pancreatitis generally presents symptomatically as recurrent abdominal pain, which becomes persistent over time. The pain eventually becomes disabling. Once specific medical treatments and endoscopic interventions are no longer efficacious, total pancreatectomy is the alternative of choice for helping the patient achieve pain control. While daily administrations of digestive enzymes cannot be avoided, insulin-dependent diabetes can be prevented by transplanting the isolated pancreatic islets back to the patient. The greater the number of islets infused, the greater the chance to prevent or at least control the effects of surgical diabetes. We present here a technical approach for the isolation and preservation of the islets proven to be efficient to obtain high numbers of islets, favoring the successful treatment of young patients.

  12. Emerging role of Hippo signalling in pancreatic biology: YAP re-expression and plausible link to islet cell apoptosis and replication.

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    Sharma, Anjana; Yerra, Veera Ganesh; Kumar, Ashutosh

    2017-02-01

    Diabetes mellitus is an ailment that develops when the functional capacity of the pancreas does not meet the metabolic requirements of the whole body, either due to insulin insufficiency or resistance to insulin action. Current therapies that control glycaemia are limited by their unwanted effects or their inability to prevent the development of long-term complications. Regeneration and replacement of beta cell therapies are shaping the goals of future management of diabetes. The Hippo pathway, first discovered in Drosophila melanogaster, plays a vital role in controlling the organ size. Nuclear recruitment of YAP/TAZ (Yes-associated protein/transcriptional co-activator with PDZ-binding motif), a mammalian analogue of Yorkie protein found in Drosophila, activates cell proliferation and inhibits apoptosis. YAP was found to regulate early pancreatic development followed by downregulation during Ngn3-specific endocrine lineage maturation corresponding to their mitotic quiescence. Recent evidences have shown that optimum modulation of upstream kinases in the Hippo signalling pathway may lead to apoptosis inhibition and renewal of progenitor as well as stem cells in case of tissue or cell injury. This article reviews the evidences linking the role of various components of the Hippo pathway to pancreatic regeneration. In particular, the focus is on the beneficial role of induced YAP expression and its nuclear distribution on apoptosis and replication of adult pancreatic β islets. This approach may be of immense significance towards our fight against diabetes; thus, more insightful research is warranted in the area of Hippo signalling pathway and its involvement in pancreatic regeneration. Copyright © 2016 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  13. Essential role of the small GTPase Ran in postnatal pancreatic islet development.

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    Fang Xia

    Full Text Available The small GTPase Ran orchestrates pleiotropic cellular responses of nucleo-cytoplasmic shuttling, mitosis and subcellular trafficking, but whether deregulation of these pathways contributes to disease pathogenesis has remained elusive. Here, we generated transgenic mice expressing wild type (WT Ran, loss-of-function Ran T24N mutant or constitutively active Ran G19V mutant in pancreatic islet β cells under the control of the rat insulin promoter. Embryonic pancreas and islet development, including emergence of insulin(+ β cells, was indistinguishable in control or transgenic mice. However, by one month after birth, transgenic mice expressing any of the three Ran variants exhibited overt diabetes, with hyperglycemia, reduced insulin production, and nearly complete loss of islet number and islet mass, in vivo. Deregulated Ran signaling in transgenic mice, adenoviral over-expression of WT or mutant Ran in isolated islets, or short hairpin RNA (shRNA silencing of endogenous Ran in model insulinoma INS-1 cells, all resulted in decreased expression of the pancreatic and duodenal homeobox transcription factor, PDX-1, and reduced β cell proliferation, in vivo. These data demonstrate that a finely-tuned balance of Ran GTPase signaling is essential for postnatal pancreatic islet development and glucose homeostasis, in vivo.

  14. Phase transitions in pancreatic islet cellular networks and implications for type-1 diabetes

    Science.gov (United States)

    Stamper, I. J.; Jackson, Elais; Wang, Xujing

    2014-01-01

    In many aspects the onset of a chronic disease resembles a phase transition in a complex dynamic system: Quantitative changes accumulate largely unnoticed until a critical threshold is reached, which causes abrupt qualitative changes of the system. In this study we examine a special case, the onset of type-1 diabetes (T1D), a disease that results from loss of the insulin-producing pancreatic islet β cells. Within each islet, the β cells are electrically coupled to each other via gap-junctional channels. This intercellular coupling enables the β cells to synchronize their insulin release, thereby generating the multiscale temporal rhythms in blood insulin that are critical to maintaining blood glucose homeostasis. Using percolation theory we show how normal islet function is intrinsically linked to network connectivity. In particular, the critical amount of β-cell death at which the islet cellular network loses site percolation is consistent with laboratory and clinical observations of the threshold loss of β cells that causes islet functional failure. In addition, numerical simulations confirm that the islet cellular network needs to be percolated for β cells to synchronize. Furthermore, the interplay between site percolation and bond strength predicts the existence of a transient phase of islet functional recovery after onset of T1D and introduction of treatment, potentially explaining the honeymoon phenomenon. Based on these results, we hypothesize that the onset of T1D may be the result of a phase transition of the islet β-cell network.

  15. Immunohistochemical and morphometric study of the development of fetal and newborn rat pancreatic islets

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    Badawoud, Mohammed H.

    2003-01-01

    Aim of this study is to perform a detailed morphometric immunohistochemichal study of develpment of fetal and newborn rat pancreatic islets. 24 pancreas were obtained from 19 and 21-day-old fetal rats,1 and 4-day-old newborn rats. They were fixed in a buffered neutral formalin ,dehydrated and embedded in paraplast. Sections were stained with anti-insulin antibodies. Study was performed at Department of Anatomy, King Abdul-Aziz University, Jeddah,Kingdom of Saudi Arabia, between 2001 and 2002. The volume density of B cells showed a grdual increase during the last days of gestation and a slight increase during the first 4 days after birth. All the other morphometric parameters showed a gradual increase during the last days of gestation and during the first days after birth.The B cell nuclear diameter and volume showed a slight increase after birth. B cells were stained and present in the central part of of fetal and new born islets,while the other islet cells were present in the periphery of the islets. The size of endocrine tissue, which was represented by the islet diameter, islet volume, islet volume density, total number of islet cells,number of B cells and volume density of B cells showed a progressive increase during the prenatal period. (author)

  16. Tacrolimus inhibits the revascularization of isolated pancreatic islets.

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    Ryuichi Nishimura

    Full Text Available AIMS: Immunosuppressive drugs could be crucial factors for a poor outcome after islet allotransplantation. Unlike rapamycin, the effects of tacrolimus, the current standard immunosuppressant used in islet transplantation, on graft revascularization remain unclear. We examined the effects of tacrolimus on islet revascularization using a highly sensitive imaging system, and analyzed the gene expression in transplanted islets by introducing laser microdissection techniques. METHODS: Islets isolated from C57BL/6-Tg (CAG-EGFP mice were transplanted into the nonmetallic dorsal skinfold chamber on the recipients. Balb/c athymic mice were used as recipients and were divided into two groups: including a control group (n = 9 and tacrolimus-treated group (n = 7. The changes in the newly-formed vessels surrounding the islet grafts were imaged and semi-quantified using multi-photon laser-scanning microscopy and a Volocity system. Gene expression in transplanted islets was analyzed by the BioMark dynamic system. RESULTS: The revascularization process was completed within 14 days after pancreatic islet transplantation at subcutaneous sites. The newly-formed vascular volume surrounding the transplanted islets in the tacrolimus-treated group was significantly less than that in the control group (p<0.05. Although the expression of Vegfa (p<0.05 and Ccnd1 (p<0.05 was significantly upregulated in the tacrolimus-treated group compared with that of the control group, no differences were observed between the groups in terms of other types of gene expression. CONCLUSIONS: The present study demonstrates that tacrolimus inhibits the revascularization of isolated pancreatic islets without affecting the characteristics of the transplanted grafts. Further refinements of this immunosuppressive regimen, especially regarding the revascularization of islet grafts, could improve the outcome of islet allotransplantation.

  17. Altered Expression of Somatostatin Receptors in Pancreatic Islets from NOD Mice Cultured at Different Glucose Concentrations In Vitro and in Islets Transplanted to Diabetic NOD Mice In Vivo

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    Eva Ludvigsen

    2011-01-01

    Full Text Available Somatostatin acts via five receptors (sst1-5. We investigated if the changes in pancreatic islet sst expression in diabetic NOD mice compared to normoglycemic mice are a consequence of hyperglycemia or the ongoing immune reaction in the pancreas. Pancreatic islets were isolated from NOD mice precultured for 5 days and further cultured for 3 days at high or low glucose before examined. Islets were also isolated from NOD mice and transplanted to normal or diabetic mice in a number not sufficient to cure hyperglycemia. After three days, the transplants were removed and stained for sst1-5 and islet hormones. Overall, changes in sst islet cell expression were more common in islets cultured in high glucose concentration in vitro as compared to the islet transplantation in vivo to diabetic mice. The beta and PP cells exhibited more frequent changes in sst expression, while the alpha and delta cells were relatively unaffected by the high glucose condition. Our findings suggest that the glucose level may alter sst expressed in islets cells; however, immune mechanisms may counteract such changes in islet sst expression.

  18. Delta-like Ligand-4-Notch Signaling Inhibition Regulates Pancreatic Islet Function and Insulin Secretion

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    Fabienne Billiard

    2018-01-01

    Full Text Available Although Notch signaling has been proposed as a therapeutic target for type-2 diabetes, liver steatosis, and atherosclerosis, its direct effect on pancreatic islets remains unknown. Here, we demonstrated a function of Dll4-Notch signaling inhibition on the biology of insulin-producing cells. We confirmed enhanced expression of key Notch signaling genes in purified pancreatic islets from diabetic NOD mice and showed that treatment with anti-Dll4 antibody specifically abolished Notch signaling pathway activation. Furthermore, we showed that Notch inhibition could drive proliferation of β-islet cells and confer protection from the development of STZ-induced diabetes. Importantly, inhibition of the Dll4 pathway in WT mice increased insulin secretion by inducing the differentiation of pancreatic β-islet cell progenitors, as well as the proliferation of insulin-secreting cells. These findings reveal a direct effect of Dll4-blockade on pancreatic islets that, in conjunction with its immunomodulatory effects, could be used for unmet medical needs hallmarked by inefficient insulin action.

  19. Microencapsulated 3-dimensional sensor for the measurement of oxygen in single isolated pancreatic islets.

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    Wanyu Chen

    Full Text Available Oxygen consumption reflects multiple processes in pancreatic islets including mechanisms contributing to insulin secretion, oxidative stress and viability, providing an important readout in studies of islet function, islet viability and drug testing. Due to the scarcity, heterogeneity, and intrinsic kinetic properties of individual islets, it would be of great benefit to detect oxygen consumption by single islets. We present a novel method we have developed to image oxygen in single islets.Using a microfluidics system, individual islets and a fluorescent oxygen-sensitive dye were encased within a thin alginate polymer layer. Insulin secretion by the encapsulated islets was normal. Fluorescent signal from the encased dye, detected using a standard inverted fluorescence microscope and digital camera, was stable and proportional to the amount of oxygen in the media. When integrated into a perifusion system, the sensing system detected changes in response to metabolic substrates, mitochondrial poisons, and induced-oscillations. Glucose responses averaged 30.1±7.1% of the response to a metabolic inhibitor (cyanide, increases were observed in all cases (n = 6, and the system was able to resolve changes in oxygen consumption that had a period greater than 0.5 minutes. The sensing system operated similarly from 2-48 hours following encapsulation, and viability and function of the islets were not significantly affected by the encapsulation process.An oxygen-dependent dye situated around and within a pancreatic islet encapsulated by a thin layer of alginate was sensitive to changes in oxygen consumption, and was not harmful to the function or viability of islets over the course of two days. The microcapsule-based sensing method is particularly suited to assessing the effects of compounds (dose responses and time courses and chronic changes occurring over the course of days. The approach should be applicable to other cell types and dyes sensitive to other

  20. Microencapsulated 3-Dimensional Sensor for the Measurement of Oxygen in Single Isolated Pancreatic Islets

    Science.gov (United States)

    Khalil, Gamal; Sweet, Ian R.; Shen, Amy Q.

    2012-01-01

    Background Oxygen consumption reflects multiple processes in pancreatic islets including mechanisms contributing to insulin secretion, oxidative stress and viability, providing an important readout in studies of islet function, islet viability and drug testing. Due to the scarcity, heterogeneity, and intrinsic kinetic properties of individual islets, it would be of great benefit to detect oxygen consumption by single islets. We present a novel method we have developed to image oxygen in single islets. Methodology/Principal Findings Using a microfluidics system, individual islets and a fluorescent oxygen-sensitive dye were encased within a thin alginate polymer layer. Insulin secretion by the encapsulated islets was normal. Fluorescent signal from the encased dye, detected using a standard inverted fluorescence microscope and digital camera, was stable and proportional to the amount of oxygen in the media. When integrated into a perifusion system, the sensing system detected changes in response to metabolic substrates, mitochondrial poisons, and induced-oscillations. Glucose responses averaged 30.1±7.1% of the response to a metabolic inhibitor (cyanide), increases were observed in all cases (n = 6), and the system was able to resolve changes in oxygen consumption that had a period greater than 0.5 minutes. The sensing system operated similarly from 2–48 hours following encapsulation, and viability and function of the islets were not significantly affected by the encapsulation process. Conclusions/Significance An oxygen-dependent dye situated around and within a pancreatic islet encapsulated by a thin layer of alginate was sensitive to changes in oxygen consumption, and was not harmful to the function or viability of islets over the course of two days. The microcapsule-based sensing method is particularly suited to assessing the effects of compounds (dose responses and time courses) and chronic changes occurring over the course of days. The approach should be

  1. Human pancreatic islet-derived extracellular vesicles modulate insulin expression in 3D-differentiating iPSC clusters.

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    Diana Ribeiro

    Full Text Available It has been suggested that extracellular vesicles (EVs can mediate crosstalk between hormones and metabolites within pancreatic tissue. However, the possible effect of pancreatic EVs on stem cell differentiation into pancreatic lineages remains unknown. Herein, human islet-derived EVs (h-Islet-EVs were isolated, characterized and subsequently added to human induced pluripotent stem cell (iPSC clusters during pancreatic differentiation. The h-islet-EVs had a mean size of 117±7 nm and showed positive expression of CD63 and CD81 EV markers as measured by ELISA. The presence of key pancreatic transcription factor mRNA, such as NGN3, MAFA and PDX1, and pancreatic hormone proteins such as C-peptide and glucagon, were confirmed in h-Islet-EVs. iPSC clusters were differentiated in suspension and at the end stages of the differentiation protocol, the mRNA expression of the main pancreatic transcription factors and pancreatic hormones was increased. H-Islet-EVs were supplemented to the iPSC clusters in the later stages of differentiation. It was observed that h-Islet-EVs were able to up-regulate the intracellular levels of C-peptide in iPSC clusters in a concentration-dependent manner. The effect of h-Islet-EVs on the differentiation of iPSC clusters cultured in 3D-collagen hydrogels was also assessed. Although increased mRNA expression for pancreatic markers was observed when culturing the iPSC clusters in 3D-collagen hydrogels, delivery of EVs did not affect the insulin or C-peptide intracellular content. Our results provide new information on the role of h-Islet-EVs in the regulation of insulin expression in differentiating iPSC clusters, and are highly relevant for pancreatic tissue engineering applications.

  2. Adoptive infusion of tolerogenic dendritic cells prolongs the survival of pancreatic islet allografts: a systematic review of 13 mouse and rat studies.

    Directory of Open Access Journals (Sweden)

    Guixiang Sun

    Full Text Available OBJECTIVE: The first Phase I study of autologous tolerogenic dendritic cells (Tol-DCs in Type 1 diabetes (T1D patients was recently completed. Pancreatic islet transplantation is an effective therapy for T1D, and infusion of Tol-DCs can control diabetes development while promoting graft survival. In this study, we aim to systematically review islet allograft survival following infusion of Tol-DCs induced by different methods, to better understand the mechanisms that mediate this process. METHODS: We searched PubMed and Embase (from inception to February 29(th, 2012 for relevant publications. Data were extracted and quality was assessed by two independent reviewers. We semiquantitatively analyzed the effects of Tol-DCs on islet allograft survival using mixed leukocyte reaction, Th1/Th2 differentiation, Treg induction, and cytotoxic T lymphocyte activity as mechanisms related-outcomes. We discussed the results with respect to possible mechanisms that promote survival. RESULTS: Thirteen articles were included. The effects of Tol-DCs induced by five methods on allograft survival were different. Survival by each method was prolonged as follows: allopeptide-pulsed Tol-DCs (42.14 ± 44 days, drug intervention (39 days, mesenchymal stem cell induction (23 days, genetic modification (8.99 ± 4.75 days, and other derivation (2.61 ± 6.98 days. The results indicate that Tol-DC dose and injection influenced graft survival. Single-dose injections of 10(4 Tol-DCs were the most effective for allograft survival, and multiple injections were not superior. Tol-DCs were also synergistic with immunosuppressive drugs or costimulation inhibitors. Possible mechanisms include donor specific T cell hyporesponsiveness, Th2 differentiation, Treg induction, cytotoxicity against allograft reduction, and chimerism induction. CONCLUSIONS: Tol-DCs induced by five methods prolong MHC mismatched islet allograft survival to different degrees, but allopeptide-pulsed host DCs

  3. Obestatin enhances in vitro generation of pancreatic islets through regulation of developmental pathways.

    Directory of Open Access Journals (Sweden)

    Alessandra Baragli

    Full Text Available Availability of large amounts of in vitro generated β-cells may support replacement therapy in diabetes. However, methods to obtain β-cells from stem/progenitor cells are limited by inefficient endocrine differentiation. We have recently shown that the ghrelin gene product obestatin displays beneficial effects on pancreatic β-cell survival and function. Obestatin prevents β-cell apoptosis, preserves β-cell mass and stimulates insulin secretion in vitro and in vivo, in both normal and diabetic conditions. In the present study, we investigated whether obestatin may promote in vitro β-cell generation from mouse pancreatic islet-derived precursor cells. Treatment of cultured islets of Langerhans with obestatin (i enriched cells expressing the mesenchymal/neuronal marker nestin, which is associated with pancreatic precursors; (ii increased cell survival and reduced apoptosis during precursor selection; (iii promoted the generation of islet-like cell clusters (ICCs with increased insulin gene expression and C-peptide secretion. Furthermore, obestatin modulated the expression of fibroblast growth factor receptors (FGFRs, Notch receptors and neurogenin 3 (Ngn3 during islet-derived precursor cell selection and endocrine differentiation. These results indicate that obestatin improves the generation of functional β-cells/ICCs in vitro, suggesting implications for cell-based replacement therapy in diabetes. Moreover, obestatin may play a role in regulating pathways involved in pancreas development and regeneration.

  4. Current and Future Perspectives on Alginate Encapsulated Pancreatic Islet.

    Science.gov (United States)

    Strand, Berit L; Coron, Abba E; Skjak-Braek, Gudmund

    2017-04-01

    Transplantation of pancreatic islets in immune protective capsules holds the promise as a functional cure for type 1 diabetes, also about 40 years after the first proof of principal study. The concept is simple in using semipermeable capsules that allow the ingress of oxygen and nutrients, but limit the access of the immune system. Encapsulated human islets have been evaluated in four small clinical trials where the procedure has been evaluated as safe, but lacking long-term efficacy. Host reactions toward the biomaterials used in the capsules may be one parameter limiting the long-term function of the graft in humans. The present article briefly discusses important capsule properties such as stability, permeability and biocompatibility, as well as possible strategies to overcome current challenges. Also, recent progress in capsule development as well as the production of insulin-producing cells from human stem cells that gives promising perspectives for the transplantation of encapsulated insulin-producing tissue is briefly discussed. Stem Cells Translational Medicine 2017;6:1053-1058. © 2017 The Authors Stem Cells Translational Medicine published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.

  5. Delineation of glutamate pathways and secretory responses in pancreatic islets with ß-cell-specific abrogation of the glutamate dehydrogenase

    DEFF Research Database (Denmark)

    Vetterli, Laurene; Carobbio, Stefania; Pournourmohammadi, Shirin

    2012-01-01

    isolated from βGlud1(-/-) mice exhibited half of the response measured in control islets. The amplifying pathway, tested at stimulatory glucose concentrations in the presence of KCl and diazoxide, was markedly inhibited in βGlud1(-/-) islets. On glucose stimulation, net synthesis of glutamate from α......-ketoglutarate was impaired in GDH-deficient islets. Accordingly, glucose-induced elevation of glutamate levels observed in control islets was absent in βGlud1(-/-) islets. Parallel biochemical pathways, namely alanine and aspartate aminotransferases, could not compensate for the lack of GDH. However, the secretory response...... to glucose was fully restored by the provision of cellular glutamate when βGlud1(-/-) islets were exposed to dimethyl glutamate. This shows that permissive levels of glutamate are required for the full development of glucose-stimulated insulin secretion and that GDH plays an indispensable role...

  6. Rat pancreatic islet size standardization by the "hanging drop" technique.

    Science.gov (United States)

    Cavallari, G; Zuellig, R A; Lehmann, R; Weber, M; Moritz, W

    2007-01-01

    Rejection and hypoxia are the main factors that limit islet engraftment in the recipient liver in the immediate posttransplant period. Recently authors have reported a negative relationship of graft function and islet size, concluding that small islets are superior to large islets. Islets can be dissociated into single cells and reaggregated into so called "pseudoislets," which are functionally equivalent to intact islets but exhibit reduced immunogenicity. The aim of our study was develop a technique that enabled one to obtain pseudoislets of defined, preferably small, dimensions. Islets were harvested from Lewis rats by the collagenase digestion procedure. After purification, the isolated islets were dissociated into single cells by trypsin digestion. Fractions with different cell numbers were seeded into single drops onto cell culture dishes, which were inverted and incubated for 5 to 8 days under cell culture conditions. Newly formed pseudoislets were analyzed for dimension, morphology, and cellular composition. The volume of reaggregated pseudoislets strongly correlated with the cell number (r(2) = .995). The average diameter of a 250-cell aggregate was 95 +/- 8 microm (mean +/- SD) compared with 122 +/- 46 microm of freshly isolated islets. Islet cell loss may be minimized by performing reaggregation in the presence of medium glucose (11 mmol/L) and the GLP-1 analogue Exendin-4. Morphology, cellular composition, and architecture of reaggregated islets were comparable to intact islets. The "hanging drop" culture method allowed us to obtain pseudoislets of standardized size and regular shape, which did not differ from intact islets in terms of cellular composition or architecture. Further investigations are required to minimize cell loss and test in vivo function of transplanted pseudoislets.

  7. MULTIHORMONAL ISLET CELL CARCINOMAS IN THREE KOMODO DRAGONS (VARANUS KOMODOENSIS).

    Science.gov (United States)

    Eustace, Ronan; Garner, Michael M; Cook, Kimberly; Miller, Christine; Kiupel, Matti

    2017-03-01

      Multihormonal pancreatic islet cell carcinomas were found in one female and two male captive geriatric Komodo dragons (Varanus komodoensis). Gross changes in the pancreas were visible in two of the cases. Clinical signs noted in the Komodo dragons were lethargy, weakness, and anorexia. Histologically, the tumors were comprised of nests and cords of well-differentiated neoplastic islet cells with scant amounts of eosinophilic cytoplasm and round, euchromatic nuclei, with rare mitoses. Infiltration by the islet cell tumor into the surrounding acinar tissue was observed in all cases, but no metastatic foci were seen. Multihormone expression was observed in all tumors, which labeled strongly positive for glucagon and somatostatin and focally positive for polypeptide. Pancreatic islet cell neoplasms should be considered in the differential diagnosis for geriatric Komodo dragons presenting with weakness, lethargy, and poor appetite.

  8. Metabolomics applied to the pancreatic islet.

    Science.gov (United States)

    Gooding, Jessica R; Jensen, Mette V; Newgard, Christopher B

    2016-01-01

    Metabolomics, the characterization of the set of small molecules in a biological system, is advancing research in multiple areas of islet biology. Measuring a breadth of metabolites simultaneously provides a broad perspective on metabolic changes as the islets respond dynamically to metabolic fuels, hormones, or environmental stressors. As a result, metabolomics has the potential to provide new mechanistic insights into islet physiology and pathophysiology. Here we summarize advances in our understanding of islet physiology and the etiologies of type-1 and type-2 diabetes gained from metabolomics studies. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Striated Muscle as Implantation Site for Transplanted Pancreatic Islets

    Directory of Open Access Journals (Sweden)

    Daniel Espes

    2011-01-01

    Full Text Available Islet transplantation is an attractive treatment for selected patients with brittle type 1 diabetes. In the clinical setting, intraportal transplantation predominates. However, due to extensive early islet cell death, the quantity of islets needed to restore glucose homeostasis requires in general a minimum of two donors. Moreover, the deterioration of islet function over time results in few insulin-independent patients after five-year followup. Specific obstacles to the success of islet transplantation include site-specific concerns for the liver such as the instant blood mediated inflammatory reaction, islet lipotoxicity, low oxygen tension, and poor revascularization, impediments that have led to the developing interest for alternative implantation sites over recent years. Within preclinical settings, several alternative sites have now been investigated and proven favorable in various aspects. Muscle is considered a very promising site and has physiologically properties and technical advantages that could make it optimal for islet transplantation.

  10. Immunohistochemical expression of insulin, glucagon, and somatostatin in pancreatic islets of horses with and without insulin resistance.

    Science.gov (United States)

    Newkirk, Kim M; Ehrensing, Gordon; Odoi, Agricola; Boston, Raymond C; Frank, Nicholas

    2018-02-01

    OBJECTIVE To assess insulin, glucagon, and somatostatin expression within pancreatic islets of horses with and without insulin resistance. ANIMALS 10 insulin-resistant horses and 13 insulin-sensitive horses. PROCEDURES For each horse, food was withheld for at least 10 hours before a blood sample was collected for determination of serum insulin concentration. Horses with a serum insulin concentration horses with a serum insulin concentration > 20 μU/mL underwent a frequently sampled IV glucose tolerance test to determine sensitivity to insulin by minimal model analysis. Horses with a sensitivity to insulin horses were euthanized with a barbiturate overdose, and pancreatic specimens were harvested and immunohistochemically stained for determination of insulin, glucagon, and somatostatin expression in pancreatic islets. Islet hormone expression was compared between insulin-resistant and insulin-sensitive horses. RESULTS Cells expressing insulin, glucagon, and somatostatin made up approximately 62%, 12%, and 7%, respectively, of pancreatic islet cells in insulin-resistant horses and 64%, 18%, and 9%, respectively, of pancreatic islet cells in insulin-sensitive horses. Expression of insulin and somatostatin did not differ between insulin-resistant and insulin-sensitive horses, but the median percentage of glucagon-expressing cells in the islets of insulin-resistant horses was significantly less than that in insulin-sensitive horses. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that, in insulin-resistant horses, insulin secretion was not increased but glucagon production might be downregulated as a compensatory response to hyperinsulinemia.

  11. Considerations for successful transplantation of encapsulated pancreatic islets

    NARCIS (Netherlands)

    de Vos, P; Hamel, AF; Tatarkiewicz, K

    Encapsulation of pancreatic islets allows for transplantion in the absence of immunosuppression. The technology is based on the principle that transplanted tissue is protected for the host immune system by an artificial membrane. Encapsulation offers a solution to the shortage of donors in clinical

  12. In vitro assessment of pancreatic islet vitality by oxymetry

    Czech Academy of Sciences Publication Activity Database

    Zacharovová, K.; Berková, Z.; Špaček, Tomáš; Kříž, J.; Dovolilová, E.; Girman, P.; Koblas, T.; Ježek, Petr; Saudek, F.

    2005-01-01

    Roč. 37, č. 8 (2005), s. 3454-3456 ISSN 0041-1345 R&D Projects: GA MZd(CZ) NR7917 Institutional research plan: CEZ:AV0Z50110509 Keywords : pancreatic islet viability * polarographic oxymetry Subject RIV: FB - Endocrinology, Diabetology, Metabolism, Nutrition Impact factor: 0.799, year: 2005

  13. Overexpression of IRS2 in isolated pancreatic islets causes proliferation and protects human β-cells from hyperglycemia-induced apoptosis

    International Nuclear Information System (INIS)

    Mohanty, S.; Spinas, G.A.; Maedler, K.; Zuellig, R.A.; Lehmann, R.; Donath, M.Y.; Trueb, T.; Niessen, M.

    2005-01-01

    Studies in vivo indicate that IRS2 plays an important role in maintaining functional β-cell mass. To investigate if IRS2 autonomously affects β-cells, we have studied proliferation, apoptosis, and β-cell function in isolated rat and human islets after overexpression of IRS2 or IRS1. We found that β-cell proliferation was significantly increased in rat islets overexpressing IRS2 while IRS1 was less effective. Moreover, proliferation of a β-cell line, INS-1, was decreased after repression of Irs2 expression using RNA oligonucleotides. Overexpression of IRS2 in human islets significantly decreased apoptosis of β-cells, induced by 33.3 mM D-glucose. However, IRS2 did not protect cultured rat islets against apoptosis in the presence of 0.5 mM palmitic acid. Overexpression of IRS2 in isolated rat islets significantly increased basal and D-glucose-stimulated insulin secretion as determined in perifusion experiments. Therefore, IRS2 is sufficient to induce proliferation in rat islets and to protect human β-cells from D-glucose-induced apoptosis. In addition, IRS2 can improve β-cell function. Our results indicate that IRS2 acts autonomously in β-cells in maintenance and expansion of functional β-cell mass in vivo

  14. Long-term normalization of diabetes mellitus after xenotransplantation of fetal pancreatic islet cells into the blood stream without immunosuppresive therapy.

    Science.gov (United States)

    Prochorov, A V; Tretjak, S I; Roudenok, V V; Goranov, V A

    2004-11-01

    The article presents a new method of surgical treatment of experimental diabetes mellitus in a rabbit to dog model. Rabbit islet cells, which had been macroencapsulated into a microporous polyamide, were implanted into the dog aorta without immunosuppressive therapy. Euglycemia was reached at 4 to 5 days and persisted for 12 months. Morphological and immunohistochemical investigations showed long-term preservation of islet cell viability, absence of graft rejection, and formation of a biological artificial pancreas in the capsule at 6 months after transplantation. Up to 60% of transplanted cells were still viable 12 months later. The major factor contributing to preservation of islet cells is neo-angiogenesis, which develops during the first weeks after transplantation. Double immune isolation of islet cells by macroencapsulation with implantation into the blood stream allows the use of either xenotransplantation or allotransplantation.

  15. Distinct cell clusters touching islet cells induce islet cell replication in association with over-expression of Regenerating Gene (REG protein in fulminant type 1 diabetes.

    Directory of Open Access Journals (Sweden)

    Kaoru Aida

    Full Text Available BACKGROUND: Pancreatic islet endocrine cell-supporting architectures, including islet encapsulating basement membranes (BMs, extracellular matrix (ECM, and possible cell clusters, are unclear. PROCEDURES: The architectures around islet cell clusters, including BMs, ECM, and pancreatic acinar-like cell clusters, were studied in the non-diabetic state and in the inflamed milieu of fulminant type 1 diabetes in humans. RESULT: Immunohistochemical and electron microscopy analyses demonstrated that human islet cell clusters and acinar-like cell clusters adhere directly to each other with desmosomal structures and coated-pit-like structures between the two cell clusters. The two cell-clusters are encapsulated by a continuous capsule composed of common BMs/ECM. The acinar-like cell clusters have vesicles containing regenerating (REG Iα protein. The vesicles containing REG Iα protein are directly secreted to islet cells. In the inflamed milieu of fulminant type 1 diabetes, the acinar-like cell clusters over-expressed REG Iα protein. Islet endocrine cells, including beta-cells and non-beta cells, which were packed with the acinar-like cell clusters, show self-replication with a markedly increased number of Ki67-positive cells. CONCLUSION: The acinar-like cell clusters touching islet endocrine cells are distinct, because the cell clusters are packed with pancreatic islet clusters and surrounded by common BMs/ECM. Furthermore, the acinar-like cell clusters express REG Iα protein and secrete directly to neighboring islet endocrine cells in the non-diabetic state, and the cell clusters over-express REG Iα in the inflamed milieu of fulminant type 1 diabetes with marked self-replication of islet cells.

  16. Total pancreatectomy and islet autotransplantation for chronic pancreatitis.

    Science.gov (United States)

    Sutherland, David E R; Radosevich, David M; Bellin, Melena D; Hering, Bernard J; Beilman, Gregory J; Dunn, Ty B; Chinnakotla, Srinath; Vickers, Selwyn M; Bland, Barbara; Balamurugan, A N; Freeman, Martin L; Pruett, Timothy L

    2012-04-01

    Total pancreatectomy (TP) with intraportal islet autotransplantation (IAT) can relieve pain and preserve β-cell mass in patients with chronic pancreatitis (CP) when other therapies fail. We report on a >30-year single-center series. Four hundred and nine patients (including 53 children, 5 to 18 years) with CP underwent TP-IAT from February 1977 to September 2011 (etiology: idiopathic, 41%; Sphincter of Oddi dysfunction/biliary, 9%; genetic, 14%; divisum, 17%; alcohol, 7%; and other, 12%; mean age was 35.3 years, 74% were female; 21% has earlier operations, including 9% Puestow procedure, 6% Whipple, 7% distal pancreatectomy, and 2% other). Islet function was classified as insulin independent for those on no insulin; partial, if known C-peptide positive or euglycemic on once-daily insulin; and insulin dependent if on standard basal-bolus diabetic regimen. A 36-item Short Form (SF-36) survey for quality of life was completed by patients before and in serial follow-up since 2007, with an integrated survey that was added in 2008. Actuarial patient survival post TP-IAT was 96% in adults and 98% in children (1 year) and 89% and 98% (5 years). Complications requiring relaparotomy occurred in 15.9% and bleeding (9.5%) was the most common complication. IAT function was achieved in 90% (C-peptide >0.6 ng/mL). At 3 years, 30% were insulin independent (25% in adults, 55% in children) and 33% had partial function. Mean hemoglobin A1c was 5,000/kg [24%]) correlated with degree of function with insulin-independent rates at 3 years of 12%, 22%, and 72%, and rates of partial function 33%, 62%, and 24%. All patients had pain before TP-IAT and nearly all were on daily narcotics. After TP-IAT, 85% had pain improvement. By 2 years, 59% had ceased narcotics. All children were on narcotics before, 39% at follow-up; pain improved in 94%; and 67% became pain-free. In the SF-36 survey, there was significant improvement from baseline in all dimensions, including the Physical and Mental

  17. Assessment of Toxicological Perturbations and Variants of Pancreatic Islet Development in the Zebrafish Model

    Directory of Open Access Journals (Sweden)

    Karilyn E. Sant

    2016-09-01

    Full Text Available The pancreatic islets, largely comprised of insulin-producing beta cells, play a critical role in endocrine signaling and glucose homeostasis. Because they have low levels of antioxidant defenses and a high perfusion rate, the endocrine islets may be a highly susceptible target tissue of chemical exposures. However, this endpoint, as well as the integrity of the surrounding exocrine pancreas, is often overlooked in studies of developmental toxicology. Disruption of development by toxicants can alter cell fate and migration, resulting in structural alterations that are difficult to detect in mammalian embryo systems, but that are easily observed in the zebrafish embryo model (Danio rerio. Using endogenously expressed fluorescent protein markers for developing zebrafish beta cells and exocrine pancreas tissue, we documented differences in islet area and incidence rates of islet morphological variants in zebrafish embryos between 48 and 96 h post fertilization (hpf, raised under control conditions commonly used in embryotoxicity assays. We identified critical windows for chemical exposures during which increased incidences of endocrine pancreas abnormalities were observed following exposure to cyclopamine (2–12 hpf, Mono-2-ethylhexyl phthalate (MEHP (3–48 hpf, and Perfluorooctanesulfonic acid (PFOS (3–48 hpf. Both islet area and length of the exocrine pancreas were sensitive to oxidative stress from exposure to the oxidant tert-butyl hydroperoxide during a highly proliferative critical window (72 hpf. Finally, pancreatic dysmorphogenesis following developmental exposures is discussed with respect to human disease.

  18. UCP2 mRNA expression is dependent on glucose metabolism in pancreatic islets

    International Nuclear Information System (INIS)

    Dalgaard, Louise T.

    2012-01-01

    Highlights: ► UCP2 mRNA levels are decreased in islets of Langerhans from glucokinase deficient mice. ► UCP2 mRNA up-regulation by glucose is dependent on glucokinase. ► Absence of UCP2 increases GSIS of glucokinase heterozygous pancreatic islets. ► This may protect glucokinase deficient mice from hyperglycemic damages. -- Abstract: Uncoupling Protein 2 (UCP2) is expressed in the pancreatic β-cell, where it partially uncouples the mitochondrial proton gradient, decreasing both ATP-production and glucose-stimulated insulin secretion (GSIS). Increased glucose levels up-regulate UCP2 mRNA and protein levels, but the mechanism for UCP2 up-regulation in response to increased glucose is unknown. The aim was to examine the effects of glucokinase (GK) deficiency on UCP2 mRNA levels and to characterize the interaction between UCP2 and GK with regard to glucose-stimulated insulin secretion in pancreatic islets. UCP2 mRNA expression was reduced in GK+/− islets and GK heterozygosity prevented glucose-induced up-regulation of islet UCP2 mRNA. In contrast to UCP2 protein function UCP2 mRNA regulation was not dependent on superoxide generation, but rather on products of glucose metabolism, because MnTBAP, a superoxide dismutase mimetic, did not prevent the glucose-induced up-regulation of UCP2. Glucose-stimulated insulin secretion was increased in UCP2−/− and GK+/− islets compared with GK+/− islets and UCP2 deficiency improved glucose tolerance of GK+/− mice. Accordingly, UCP2 deficiency increased ATP-levels of GK+/− mice. Thus, the compensatory down-regulation of UCP2 is involved in preserving the insulin secretory capacity of GK mutant mice and might also be implicated in limiting disease progression in MODY2 patients.

  19. Factors influencing the properties and performance of microcapsules for immunoprotection of pancreatic islets

    NARCIS (Netherlands)

    van Schilfgaarde, R; de Vos, P

    There are several approaches of immunoprotection of pancreatic islets for the purpose of successful allo- or xenotransplantation in the absence of immunosuppressive medication. Extravasculair approaches are either mac roencapsulation (large numbers of islets together in one device) or

  20. Vitality of pancreatic islets labeled for magnetic resonance imaging with iron particles.

    Science.gov (United States)

    Berkova, Z; Kriz, J; Girman, P; Zacharovova, K; Koblas, T; Dovolilova, E; Saudek, F

    2005-10-01

    We previously described an in vivo method for pancreatic islet visualization using magnetic resonance imaging with the aid of superparamagnetic nanoparticles of iron oxide (Resovist) or by magnetic beads precoated with antibodies (Dynabeads). The aim of this study was to investigate the in vitro effect of islet labeling on their quality. Isolated rat islets were cultivated for 48 hours with a contrast agent or, in the case of magnetic antibody-coated beads, for only 2 hours. The ability to secrete insulin was tested by a static insulin release assay and the results were expressed as a stimulation index. Staining with propidium iodide and acridine orange was performed to determine the ratio of live to dead cells. Stimulation indices in the Resovist islets (n = 23) vs controls (n = 14) were 15.3 and 15.0, respectively, and in the Dynabeads islets (n = 15) vs controls (n = 12) 21.3 and 19.9, respectively. The vitality of the Resovist islets vs controls determined by live/dead cells ratio was 90.8% and 91.1%, respectively (n = 20), and in the Dynabeads islets vs controls was 89.4% and 91.8%, respectively (n = 11). Islet labeling with the contrast agent as well as with specific antibodies with iron beads did not change the vitality and insulin-secreting capacity assessed in vitro (P > .05). Magnetic resonance using iron nanoparticles represents the only method for in-vivo visualization of transplanted islets so far. Our data represent an important contribution for its clinical use.

  1. Gamma radiation induced alterations in the ultrastructure of pancreatic islet, metabolism and enzymes in wistar rat

    Energy Technology Data Exchange (ETDEWEB)

    Daoo, J.V.; Suryawanshi, S.A. [Inst. of Science, Bombay (India)

    1992-07-01

    Effects of gamma irradiation (600 rads) on the ultrastructure of pancreatic islet, metabolism and some enzymes in wistar rat, are reported. Electron microscopic observations of endocrine pancreas revealed prominent changes in beta cells while alpha and delta cells were not much affected. Irradiation also inflicted hyperglycemia, increase in liver and muscle glycogen and decrease in insulin level. It has also increased the activity of enzymes but failed to produce significant changes in protein, lipid and mineral metabolism. (auth0008.

  2. Disruption of growth hormone receptor gene causes diminished pancreatic islet size and increased insulin sensitivity in mice.

    Science.gov (United States)

    Liu, Jun-Li; Coschigano, Karen T; Robertson, Katie; Lipsett, Mark; Guo, Yubin; Kopchick, John J; Kumar, Ujendra; Liu, Ye Lauren

    2004-09-01

    Growth hormone, acting through its receptor (GHR), plays an important role in carbohydrate metabolism and in promoting postnatal growth. GHR gene-deficient (GHR(-/-)) mice exhibit severe growth retardation and proportionate dwarfism. To assess the physiological relevance of growth hormone actions, GHR(-/-) mice were used to investigate their phenotype in glucose metabolism and pancreatic islet function. Adult GHR(-/-) mice exhibited significant reductions in the levels of blood glucose and insulin, as well as insulin mRNA accumulation. Immunohistochemical analysis of pancreatic sections revealed normal distribution of the islets despite a significantly smaller size. The average size of the islets found in GHR(-/-) mice was only one-third of that in wild-type littermates. Total beta-cell mass was reduced 4.5-fold in GHR(-/-) mice, significantly more than their body size reduction. This reduction in pancreatic islet mass appears to be related to decreases in proliferation and cell growth. GHR(-/-) mice were different from the human Laron syndrome in serum insulin level, insulin responsiveness, and obesity. We conclude that growth hormone signaling is essential for maintaining pancreatic islet size, stimulating islet hormone production, and maintaining normal insulin sensitivity and glucose homeostasis.

  3. Experimental treatment of diabetic mice with microencapsulated rat islet cells transplantation

    International Nuclear Information System (INIS)

    Luo Yun; Xue Yilong; Li Yanling; Li Xinjian

    2006-01-01

    To observe treatment effects of diabetic mice with microcapsulated and non-microcapsulated rat islet cell transplantation, pancreas of SD rat was perfused with collagenase through cloledchus, and then the pancreatic tissues were isolated and digested. Histopaque-1077 was used to purify the digested pancreas. Islet cells were collected and implanted into the peritoneal cavity of diabetic mice. The isolated islets had a response upon glucose stimulation. When the microcapsulated islets and non- microcapsulated islets were transplanted into diabetic mices the high blood glucose level could be decreased to normal. The normal blood glucose level in the diabetic mice transpanted with microcapsulated islets could be maintained for over 30 days,but it could be mainlained only for 2-3 days in the diabetic mice transplanted with non-microcapsulated islets. Thus it is believed that microcapsulated islet cell transplantation exerts good effect on diabetic mice and the microcapsules possessed good immunoisolating function. (authors)

  4. Application of Digital Image Analysis to Determine Pancreatic Islet Mass and Purity in Clinical Islet Isolation and Transplantation

    Science.gov (United States)

    Wang, Ling-jia; Kissler, Hermann J; Wang, Xiaojun; Cochet, Olivia; Krzystyniak, Adam; Misawa, Ryosuke; Golab, Karolina; Tibudan, Martin; Grzanka, Jakub; Savari, Omid; Grose, Randall; Kaufman, Dixon B; Millis, Michael; Witkowski, Piotr

    2015-01-01

    Pancreatic islet mass, represented by islet equivalent (IEQ), is the most important parameter in decision making for clinical islet transplantation. To obtain IEQ, the sample of islets is routinely counted manually under a microscope and discarded thereafter. Islet purity, another parameter in islet processing, is routinely acquired by estimation only. In this study, we validated our digital image analysis (DIA) system developed using the software of Image Pro Plus for islet mass and purity assessment. Application of the DIA allows to better comply with current good manufacturing practice (cGMP) standards. Human islet samples were captured as calibrated digital images for the permanent record. Five trained technicians participated in determination of IEQ and purity by manual counting method and DIA. IEQ count showed statistically significant correlations between the manual method and DIA in all sample comparisons (r >0.819 and p islet particle number (IPN) and the IEQ/IPN ratio did not differ statistically between manual counting method and DIA. In conclusion, the DIA used in this study is a reliable technique in determination of IEQ and purity. Islet sample preserved as a digital image and results produced by DIA can be permanently stored for verification, technical training and islet information exchange between different islet centers. Therefore, DIA complies better with cGMP requirements than the manual counting method. We propose DIA as a quality control tool to supplement the established standard manual method for islets counting and purity estimation. PMID:24806436

  5. Hormone-sensitive lipase deficiency suppresses insulin secretion from pancreatic islets of Lepob/ob mice

    International Nuclear Information System (INIS)

    Sekiya, Motohiro; Yahagi, Naoya; Tamura, Yoshiaki; Okazaki, Hiroaki; Igarashi, Masaki; Ohta, Keisuke; Takanashi, Mikio; Kumagai, Masayoshi; Takase, Satoru; Nishi, Makiko; Takeuchi, Yoshinori; Izumida, Yoshihiko; Kubota, Midori; Ohashi, Ken; Iizuka, Yoko; Yagyu, Hiroaki; Gotoda, Takanari; Nagai, Ryozo; Shimano, Hitoshi; Yamada, Nobuhiro

    2009-01-01

    It has long been a matter of debate whether the hormone-sensitive lipase (HSL)-mediated lipolysis in pancreatic β-cells can affect insulin secretion through the alteration of lipotoxicity. We generated mice lacking both leptin and HSL (Lep ob/ob /HSL -/- ) and explored the role of HSL in pancreatic β-cells in the setting of obesity. Lep ob/ob /HSL -/- developed elevated blood glucose levels and reduced plasma insulin levels compared with Lep ob/ob /HSL +/+ in a fed state, while the deficiency of HSL did not affect glucose homeostasis in Lep +/+ background. The deficiency of HSL exacerbated the accumulation of triglycerides in Lep ob/ob islets, leading to reduced glucose-stimulated insulin secretion. The deficiency of HSL also diminished the islet mass in Lep ob/ob mice due to decreased cell proliferation. In conclusion, HSL affects insulin secretary capacity especially in the setting of obesity.

  6. β-Cell regeneration through the transdifferentiation of pancreatic cells: Pancreatic progenitor cells in the pancreas.

    Science.gov (United States)

    Kim, Hyo-Sup; Lee, Moon-Kyu

    2016-05-01

    Pancreatic progenitor cell research has been in the spotlight, as these cells have the potential to replace pancreatic β-cells for the treatment of type 1 and 2 diabetic patients with the absence or reduction of pancreatic β-cells. During the past few decades, the successful treatment of diabetes through transplantation of the whole pancreas or isolated islets has nearly been achieved. However, novel sources of pancreatic islets or insulin-producing cells are required to provide sufficient amounts of donor tissues. To overcome this limitation, the use of pancreatic progenitor cells is gaining more attention. In particular, pancreatic exocrine cells, such as duct epithelial cells and acinar cells, are attractive candidates for β-cell regeneration because of their differentiation potential and pancreatic lineage characteristics. It has been assumed that β-cell neogenesis from pancreatic progenitor cells could occur in pancreatic ducts in the postnatal stage. Several studies have shown that insulin-producing cells can arise in the duct tissue of the adult pancreas. Acinar cells also might have the potential to differentiate into insulin-producing cells. The present review summarizes recent progress in research on the transdifferentiation of pancreatic exocrine cells into insulin-producing cells, especially duct and acinar cells.

  7. Streptozotocin Diabetes CORRELATION WITH EXTENT OF DEPRESSION OF PANCREATIC ISLET NICOTINAMIDE ADENINE DINUCLEOTIDE

    Science.gov (United States)

    Anderson, Tom; Schein, Philip S.; McMenamin, Mary G.; Cooney, David A.

    1974-01-01

    The diabetogenic activity of streptozotocin has been correlated with a reduction in pyridine nucleotide synthesis in the mouse pancreatic islet. To determine the specificity of this reduction for diabetogenicity, a comparative study of streptozotocin, its cytotoxic moiety, 1-methyl-1-nitrosourea, and alloxan was performed. Streptozotocin administered intraperitoneally (i.p.) producd a dose-related reduction in islet NAD which was proportional to the degree of diabetogenicity. A diabetogenic dose, 200 mg/kg, attained a peak plasma N-nitroso intact streptozotocin concentration of 0.224 μmol/ml and reduced the mean islet NAD from a control of 0.78 to 0.15 pmol. At borderline, 150 mg/kg, and nondiabetogenic, 100 mg/kg, doses, plasma concentrations reached 0.161 and 0.136 μmol/ml, and NAD was 0.36 and 0.86 pmol/islet, respectively. 1-Methyl-1-nitrosourea, 100 mg/kg, attained a maximum N-nitroso intact 1-methyl-1-nitrosourea concentration of 0.162 μmol/ml and reduced the mean NAD to 0.58 pmol/islet, and was nondiabetogenic; 200 mg/kg attained a peak plasma concentration of 0.344 μmol/ml and depressed NAD to 0.38 pmol/islet, and was inconsistently diabetogenic. Islet NAD of 0.4 pmol/islet or greater is required for integrity of the beta cell. A diabetogenic dose of alloxan, 500 mg/kg, did not depress NAD, 0.85 pmol/islet, therefore confirming that its mechanism of diabetogenicity differs from that of streptozotocin. In vivo uptake of [methyl-14C]streptozotocin by islets was 3.8 times that of [methyl-14C]-1-methyl-1-nitrosourea, whereas uptake by the exocrine pancreas favored 1-methyl-1-nitrosourea over streptozotocin 2.4:1. The decreased islet uptake of 1-methyl-1-nitrosourea correlates with the 3.5 times increased molar dosage required to produce islet NAD depression comparable to that of streptozotocin, 150 mg/kg. These studies indicate that the glucose carrier of streptozotocin facilitates uptake of its cytotoxic group, 1-methyl-1-nitrosourea, into islets. PMID

  8. Processing of superparamagnetic iron contrast agent ferucarbotran in transplanted pancreatic islets

    Czech Academy of Sciences Publication Activity Database

    Zacharovová, K.; Berková, Z.; Jirák, D.; Herynek, V.; Vancová, Marie; Dovolilová, E.; Saudek, F.

    2012-01-01

    Roč. 7, č. 6 (2012), s. 485-493 ISSN 1555-4309 Institutional research plan: CEZ:AV0Z60220518 Keywords : magnetic resonance imaging * pancreatic islets * transplantation * superparamagnetic iron oxide nanoparticles * ferucarbotran * β cells * diabetes * immunohistochemistry * transmission electron microscopy Subject RIV: CE - Biochemistry Impact factor: 2.872, year: 2012 http://onlinelibrary.wiley.com/doi/10.1002/cmmi.1477/full

  9. Portal Vein Embolization with Radiolabeled Polyvinyl Alcohol Particles in a Swine Model: Hepatic Distribution and Implications for Pancreatic Islet Cell Transplantation

    International Nuclear Information System (INIS)

    Owen, Richard J.; Mercer, John R.; Al-Saif, Faisal; Molinari, Michele; Ashforth, Robert A.; Rajotte, Ray V.; Conner-Spady, Barbara; Shapiro, A. M. James

    2009-01-01

    The distribution of radiolabeled polyvinyl alcohol microspheres (PVAMs) when infused into the portal vein of domestic swine was investigated, with the purpose of assessing implications for pancreatic islet cell transplantation. PVAMs measuring 100-300 μm (Contour SE) and labeled with 99m Tc were infused into the main portal vein of 12 swine, with intermittent portal venous pressure measurements. The infusion catheter was introduced antegradely via direct or indirect cannulation of the portal vein. The liver was subsequently divided into anatomical segments. Radioactivity (decay corrected) was measured for 99m Tc microsphere synthesis, dose preparation, gross organ activities, tissue samples, and blood. Particulate labeling, catheter positioning, and infusion were successful in all cases. The number of particles used was (185,000 ± 24,000) with a volume of 1 ml. Mean portal pressure at 5 min was significantly higher than baseline, but without a significant difference at 15 min. Extrahepatic tissue and serum radioactivity was negligible. A significant difference in number of radioactive particles per gram was detected between segments 6/7 and segments 5/8. Intrasegmental activity was analyzed, and for segments 2/3 a significant difference in the percentage dose per gram across samples was demonstrated (P = 0.001). Effective and stable radiolabeling of PVAMs with 99m Tc-sulfur colloid was demonstrated. Portal venous infusion of 100- to 300-μm particles showed entrapment in the sinusoidal hepatic system with transient portal pressure elevation. Preferential embolization into the right lateral and posterior segments occurs, suggesting that flow dynamics/catheter tip position plays a role in particle distribution.

  10. Glucotoxicity promotes aberrant activation and mislocalization of Ras-related C3 botulinum toxin substrate 1 [Rac1] and metabolic dysfunction in pancreatic islet β-cells: reversal of such metabolic defects by metformin.

    Science.gov (United States)

    Baidwan, Sartaj; Chekuri, Anil; Hynds, DiAnna L; Kowluru, Anjaneyulu

    2017-11-01

    Emerging evidence suggests that long-term exposure of insulin-secreting pancreatic β-cells to hyperglycemic (HG; glucotoxic) conditions promotes oxidative stress, which, in turn, leads to stress kinase activation, mitochondrial dysfunction, loss of nuclear structure and integrity and cell apoptosis. Original observations from our laboratory have proposed that Rac1 plays a key regulatory role in the generation of oxidative stress and downstream signaling events culminating in the onset of dysfunction of pancreatic β-cells under the duress of metabolic stress. However, precise molecular and cellular mechanisms underlying the metabolic roles of hyperactive Rac1 remain less understood. Using pharmacological and molecular biological approaches, we now report mistargetting of biologically-active Rac1 [GTP-bound conformation] to the nuclear compartment in clonal INS-1 cells, normal rat islets and human islets under HG conditions. Our findings also suggest that such a signaling step is independent of post-translational prenylation of Rac1. Evidence is also presented to highlight novel roles for sustained activation of Rac1 in HG-induced expression of Cluster of Differentiation 36 [CD36], a fatty acid transporter protein, which is implicated in cell apoptosis. Finally, our findings suggest that metformin, a biguanide anti-diabetic drug, at a clinically relevant concentration, prevents β-cell defects [Rac1 activation, nuclear association, CD36 expression, stress kinase and caspase-3 activation, and loss in metabolic viability] under the duress of glucotoxicity. Potential implications of these findings in the context of novel and direct regulation of islet β-cell function by metformin are discussed.

  11. Though active on RINm5F insulinoma cells and cultured pancreatic islets, recombinant IL-22 fails to modulate cytotoxicity and disease in a protocol of streptozotocin-induced experimental diabetes.

    Directory of Open Access Journals (Sweden)

    Anika eBerner

    2016-01-01

    Full Text Available Interleukin (IL-22 is a cytokine displaying tissue protective and pro-regenerative functions in various preclinical disease models. Anti-bacterial, pro-proliferative, and anti-apoptotic properties mediated by activation of the transcription factor signal transducer and activator of transcription (STAT-3 are key to biological functions of this IL-10 family member. Herein, we introduce RINm5F insulinoma cells as rat ß-cell line that, under the influence of IL-22, displays activation of STAT3 with induction of its downstream gene targets Socs3, Bcl3, and Reg3ß. In addition, IL-22 also activates STAT1 in this cell type. To refine those observations, IL-22 biological activity was evaluated using ex vivo cultivated murine pancreatic islets. In accord with data on RINm5F cells, islet exposure to IL-22 activated STAT3 and upregulation of STAT3-inducible Socs3, Bcl3, and STEAP4 was evident under those conditions. As these observations supported the hypothesis that IL-22 may exert protective functions in toxic ß-cell injury, application of IL-22 was investigated in murine multiple-low-dose streptozotocin (STZ-induced diabetes. For that purpose, recombinant IL-22 was administered thrice either immediately before and at disease onset (at d4, d6, d8 or closely thereafter (at d8, d10, d12. These two IL-22-treatment periods coincide with two early peaks of ß-cell injury detectable in this model. Notably, none of the two IL-22-treatment strategies affected diabetes incidence or blood glucose levels in STZ-treated mice. Moreover, pathological changes in islet morphology analyzed 28 days after disease induction were not ameliorated by IL-22 administration. Taken together, despite being active on rat RINm5F insulinoma cells and murine pancreatic islets, recombinant IL-22 fails to protect pancreatic ß-cells in the tested protocols from toxic effects of STZ and thus is unable to ameliorate disease in the widely used model of STZ-induced diabetes.

  12. Characterization of insulin-like growth factor I produced by fetal rat pancreatic islets

    International Nuclear Information System (INIS)

    Scharfmann, R.; Corvol, M.; Czernichow, P.

    1989-01-01

    Pancreatic islets were prepared from 22-day-old rat fetuses. After 5 days of culture in dishes allowing cell attachment, neoformed islets were kept free floating in RPMI-1640 medium (16.5 mM glucose, 1% fetal calf serum). The islets were then pulsed with [ 3 H]leucine and [ 35 S]methionine for 24 h. The conditioned medium was acidified with acetic acid (final pH 2.7), desalted, concentrated, and gel filtered on Bio-Gel P100 in acid conditions. The radioactive material that comigrated with immunoreactive insulinlike growth factor I (IGF-I) produced by the islets was pooled, concentrated, and further characterized by reverse-phase high-performance liquid chromatography on a C18 Bondapak column with a linear gradient of acetonitrile (20-80%). The radioactive material that eluted as pure IGF-I (40% acetonitrile) was further studied by chromatofocusing on a Pharmacia PBE 94 column. A sharp radioactive peak containing [ 3 H]leucine and [ 35 S]methionine was eluted at pH 8.55. This material was immunoprecipitated with an antiserum to IGF-I. This study demonstrated that fetal islet cells synthesize molecules that are, by several criteria, equivalent to native IGF-I

  13. Autologous Mesenchymal Stem Cell and Islet Cotransplantation: Safety and Efficacy.

    Science.gov (United States)

    Wang, Hongjun; Strange, Charlie; Nietert, Paul J; Wang, Jingjing; Turnbull, Taylor L; Cloud, Colleen; Owczarski, Stefanie; Shuford, Betsy; Duke, Tara; Gilkeson, Gary; Luttrell, Louis; Hermayer, Kathie; Fernandes, Jyotika; Adams, David B; Morgan, Katherine A

    2018-01-01

    Islet engraftment after transplantation is impaired by high rates of isletcell death caused by cellular stressors and poor graft vascularization. We studied whether cotransplantation of ex vivo expanded autologous bone marrow-derived mesenchymal stem cells (MSCs) with islets is safe and beneficial in chronic pancreatitis patients undergoing total pancreatectomy with islet autotransplantation. MSCs were harvested from the bone marrow of three islet autotransplantation patients and expanded at our current Good Manufacturing Practices (cGMP) facility. On the day of islet transplantation, an average dose of 20.0 ± 2.6 ×10 6 MSCs was infused with islets via the portal vein. Adverse events and glycemic control at baseline, 6, and 12 months after transplantation were compared with data from 101 historical control patients. No adverse events directly related to the MSC infusions were observed. MSC patients required lower amounts of insulin during the peritransplantation period (p = .02 vs. controls) and had lower 12-month fasting blood glucose levels (p = .02 vs. controls), smaller C-peptide declines over 6 months (p = .01 vs. controls), and better quality of life compared with controls. In conclusion, our pilot study demonstrates that autologous MSC and islet cotransplantation may be a safe and potential strategy to improve islet engraftment after transplantation. (Clinicaltrials.gov registration number: NCT02384018). Stem Cells Translational Medicine 2018;7:11-19. © 2017 The Authors Stem Cells Translational Medicine published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.

  14. AMPK is involved in the regulation of incretin receptors expression in pancreatic islets under a low glucose concentration.

    Directory of Open Access Journals (Sweden)

    Kazuki Tajima

    Full Text Available The precise role of AMP-activated protein kinase (AMPK, a target of metformin, in pancreatic β cells remains controversial, even though metformin was recently shown to enhance the expression of incretin receptors (GLP-1 and GIP receptors in pancreatic β cells. In this study, we investigated the effect of AMPK in the regulation of incretin receptors expression in pancreatic islets. The phosphorylation of AMPK in the mouse islets was decreased by increasing glucose concentrations. We showed the expression of incretin receptors in bell-shaped response to glucose. Expression of the incretin receptors in the isolated islets showed higher levels under a medium glucose concentration (11.1 mM than that under a low glucose concentration (2.8 mM, but was suppressed under a high glucose concentration (22.2 mM. Both treatment with an AMPK inhibitor and DN-AMPK expression produced a significant increase of the incretin receptors expression under a low glucose concentration. By contrast, in hyperglycemic db/db islets, the enhancing effect of the AMPK inhibitor on the expression of incretin receptors was diminished under a low glucose concentration. Taken together, AMPK is involved in the regulation of incretin receptors expression in pancreatic islets under a low glucose concentration.

  15. The specific localization of advanced glycation end-products (AGEs) in rat pancreatic islets.

    Science.gov (United States)

    Morioka, Yuta; Teshigawara, Kiyoshi; Tomono, Yasuko; Wang, Dengli; Izushi, Yasuhisa; Wake, Hidenori; Liu, Keyue; Takahashi, Hideo Kohka; Mori, Shuji; Nishibori, Masahiro

    2017-08-01

    Advanced glycation end-products (AGEs) are produced by non-enzymatic glycation between protein and reducing sugar such as glucose. Although glyceraldehyde-derived AGEs (Glycer-AGEs), one of the AGEs subspecies, have been reported to be involved in the pathogenesis of various age-relating diseases such as diabetes mellitus or arteriosclerosis, little is known about the pathological and physiological mechanism of AGEs in vivo. In present study, we produced 4 kinds of polyclonal antibodies against AGEs subspecies and investigated the localization of AGEs-modified proteins in rat peripheral tissues, making use of these antibodies. We found that Glycer-AGEs and methylglyoxal-derived AGEs (MGO-AGEs) were present in pancreatic islets of healthy rats, distinguished clearly into the pancreatic α and β cells, respectively. Although streptozotocin-induced diabetic rats suffered from remarkable impairment of pancreatic islets, the localization and deposit levels of the Glycer- and MGO-AGEs were not altered in the remaining α and β cells. Remarkably, the MGO-AGEs in pancreatic β cells were localized into the insulin-secretory granules. These results suggest that the cell-specific localization of AGEs-modified proteins are presence generally in healthy peripheral tissues, involved in physiological intracellular roles, such as a post-translational modulator contributing to the secretory and/or maturational functions of insulin. Copyright © 2017 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

  16. Mathematical model formulation and validation of water and solute transport in whole hamster pancreatic islets.

    Science.gov (United States)

    Benson, James D; Benson, Charles T; Critser, John K

    2014-08-01

    Optimization of cryopreservation protocols for cells and tissues requires accurate models of heat and mass transport. Model selection often depends on the configuration of the tissue. Here, a mathematical and conceptual model of water and solute transport for whole hamster pancreatic islets has been developed and experimentally validated incorporating fundamental biophysical data from previous studies on individual hamster islet cells while retaining whole-islet structural information. It describes coupled transport of water and solutes through the islet by three methods: intracellularly, intercellularly, and in combination. In particular we use domain decomposition techniques to couple a transmembrane flux model with an interstitial mass transfer model. The only significant undetermined variable is the cellular surface area which is in contact with the intercellularly transported solutes, Ais. The model was validated and Ais determined using a 3×3 factorial experimental design blocked for experimental day. Whole islet physical experiments were compared with model predictions at three temperatures, three perfusing solutions, and three islet size groups. A mean of 4.4 islets were compared at each of the 27 experimental conditions and found to correlate with a coefficient of determination of 0.87±0.06 (mean ± SD). Only the treatment variable of perfusing solution was found to be significant (p<0.05). We have devised a model that retains much of the intrinsic geometric configuration of the system, and thus fewer laboratory experiments are needed to determine model parameters and thus to develop new optimized cryopreservation protocols. Additionally, extensions to ovarian follicles and other concentric tissue structures may be made. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. Stevia Nonsweetener Fraction Displays an Insulinotropic Effect Involving Neurotransmission in Pancreatic Islets

    Science.gov (United States)

    Pavanello, Audrei; Peixoto, Giuliana Maria Ledesma; Matiusso, Camila Cristina Ianoni; de Moraes, Ana Maria Praxedes; Martins, Isabela Peixoto; Palma-Rigo, Kesia; da Silva Franco, Claudinéia Conationi; Milani, Paula Gimenez; Dacome, Antonio Sérgio; da Costa, Silvio Claudio; de Freitas Mathias, Paulo Cezar; Mareze-Costa, Cecília Edna

    2018-01-01

    Stevia rebaudiana (Bert.) Bertoni besides being a source of noncaloric sweeteners is also an important source of bioactive molecules. Many plant extracts, mostly obtained with ethyl acetate solvent, are rich in polyphenol compounds that present insulinotropic effects. To investigate whether the nonsweetener fraction, which is rich in phenolic compounds isolated from Stevia rebaudiana with the solvent ethyl acetate (EAF), has an insulinotropic effect, including interference at the terminals of the autonomic nervous system of the pancreatic islets of rats. Pancreatic islets were isolated from Wistar rats and incubated with EAF and inhibitory or stimulatory substances of insulin secretion, including cholinergic and adrenergic agonists and antagonists. EAF potentiates glucose-stimulated insulin secretion (GSIS) only in the presence of high glucose and calcium-dependent concentrations. EAF increased muscarinic insulinotropic effects in pancreatic islets, interfering with the muscarinic receptor subfamily M3. Adrenergic inhibitory effects on GSIS were attenuated in the presence of EAF, which interfered with the adrenergic α 2 receptor. Results suggest that EAF isolated from stevia leaves is a potential therapy for treating type 2 diabetes mellitus by stimulating insulin secretion only in high glucose concentrations, enhancing parasympathetic signal transduction and inhibiting sympathetic signal transduction in beta cells. PMID:29853880

  18. Stevia Nonsweetener Fraction Displays an Insulinotropic Effect Involving Neurotransmission in Pancreatic Islets

    Directory of Open Access Journals (Sweden)

    Silvano Piovan

    2018-01-01

    Full Text Available Stevia rebaudiana (Bert. Bertoni besides being a source of noncaloric sweeteners is also an important source of bioactive molecules. Many plant extracts, mostly obtained with ethyl acetate solvent, are rich in polyphenol compounds that present insulinotropic effects. To investigate whether the nonsweetener fraction, which is rich in phenolic compounds isolated from Stevia rebaudiana with the solvent ethyl acetate (EAF, has an insulinotropic effect, including interference at the terminals of the autonomic nervous system of the pancreatic islets of rats. Pancreatic islets were isolated from Wistar rats and incubated with EAF and inhibitory or stimulatory substances of insulin secretion, including cholinergic and adrenergic agonists and antagonists. EAF potentiates glucose-stimulated insulin secretion (GSIS only in the presence of high glucose and calcium-dependent concentrations. EAF increased muscarinic insulinotropic effects in pancreatic islets, interfering with the muscarinic receptor subfamily M3. Adrenergic inhibitory effects on GSIS were attenuated in the presence of EAF, which interfered with the adrenergic α2 receptor. Results suggest that EAF isolated from stevia leaves is a potential therapy for treating type 2 diabetes mellitus by stimulating insulin secretion only in high glucose concentrations, enhancing parasympathetic signal transduction and inhibiting sympathetic signal transduction in beta cells.

  19. Resealable, optically accessible, PDMS-free fluidic platform for ex vivo interrogation of pancreatic islets.

    Science.gov (United States)

    Lenguito, Giovanni; Chaimov, Deborah; Weitz, Jonathan R; Rodriguez-Diaz, Rayner; Rawal, Siddarth A K; Tamayo-Garcia, Alejandro; Caicedo, Alejandro; Stabler, Cherie L; Buchwald, Peter; Agarwal, Ashutosh

    2017-02-28

    We report the design and fabrication of a robust fluidic platform built out of inert plastic materials and micromachined features that promote optimized convective fluid transport. The platform is tested for perfusion interrogation of rodent and human pancreatic islets, dynamic secretion of hormones, concomitant live-cell imaging, and optogenetic stimulation of genetically engineered islets. A coupled quantitative fluid dynamics computational model of glucose stimulated insulin secretion and fluid dynamics was first utilized to design device geometries that are optimal for complete perfusion of three-dimensional islets, effective collection of secreted insulin, and minimization of system volumes and associated delays. Fluidic devices were then fabricated through rapid prototyping techniques, such as micromilling and laser engraving, as two interlocking parts from materials that are non-absorbent and inert. Finally, the assembly was tested for performance using both rodent and human islets with multiple assays conducted in parallel, such as dynamic perfusion, staining and optogenetics on standard microscopes, as well as for integration with commercial perfusion machines. The optimized design of convective fluid flows, use of bio-inert and non-absorbent materials, reversible assembly, manual access for loading and unloading of islets, and straightforward integration with commercial imaging and fluid handling systems proved to be critical for perfusion assay, and particularly suited for time-resolved optogenetics studies.

  20. Simulated Microgravity Reduces TNF-Alpha Activity, Suppresses Glucose Uptake and Enhances Arginine Flux in Pancreatic Islets of Langerhans

    Science.gov (United States)

    Tobin, Brian W.; Leeper-Woodford, Sandra K.; Hashemi, Brian B.; Smith, Scott M.; Sams, Clarence F.; Paloski, W. H. (Technical Monitor)

    2000-01-01

    The present studies were designed to determine effects of microgravity upon lipopolysaccharide (LPS) stimulated tumor necrosis factor alpha (TNF - alpha) activity and indices of insulin and fuel homeostasis of pancreatic islets of Langerhans. Islets (1726+/-117,150 u IEU) from Wistar Furth rats were treated as: 1) HARV (High Aspect Ratio Vessel cell culture) , 2) HARV plus LPS 3) static culture, 4) static culture plus LPS TNF-alpha (L929 cytotoxicity assay) was significantly increased in LPS-induced HARV and static cultures, yet the increase was more pronounced in the static culture group (palpha production of pancreatic islets of Langerhans, favoring a lesser TNF activity in the HARV paradigm. These alterations in fuel homeostasis may be promulgated by gravity averaged cell culture methods or by three dimensional cell assembly.

  1. A Stirred Microchamber for Oxygen Consumption Rate Measurements With Pancreatic Islets

    Science.gov (United States)

    Papas, Klearchos K.; Pisania, Anna; Wu, Haiyan; Weir, Gordon C.; Colton, Clark K.

    2010-01-01

    Improvements in pancreatic islet transplantation for treatment of diabetes are hindered by the absence of meaningful islet quality assessment methods. Oxygen consumption rate (OCR) has previously been used to assess the quality of organs and primary tissue for transplantation. In this study, we describe and characterize a stirred microchamber for measuring OCR with small quantities of islets. The device has a titanium body with a chamber volume of about 200 µL and is magnetically stirred and water jacketed for temperature control. Oxygen partial pressure (pO2) is measured by fluorescence quenching with a fiber optic probe, and OCR is determined from the linear decrease of pO2 with time. We demonstrate that measurements can be made rapidly and with high precision. Measurements with βTC3 cells and islets show that OCR is directly proportional to the number of viable cells in mixtures of live and dead cells and correlate linearly with membrane integrity measurements made with cells that have been cultured for 24 h under various stressful conditions. PMID:17497731

  2. Ionic effects on the uptake of chloromercuribenzene-p-sulphonic acid by pancreatic islets

    Energy Technology Data Exchange (ETDEWEB)

    Soederberg, M; Taeljedal, I B [Umeaa Univ. (Sweden)

    1977-01-01

    Effects of inorganic ions on the uptake of chloromercuribenzene-p-sulphonic acid (CMBS) were studied in microdissected pancreatic islets on non-inbred ob/ob-mice. Na/sub 2/SO/sub 4/ stimulated the total islet cell uptake of CMBS but decreased the amount of CMBS remaining in islets after brief washing with L-cysteine. CaCl/sub 2/ stimulated both the total and the cysteine-non-displaceable uptake; the stimulatory effect of CaCl/sub 2/ on the cysteine-non-displaceable CMBS uptake was counteracted by Na/sub 2/SO/sub 4/. NaCl, KCl, or choline chloride had no significant effect on the total islet cell uptake of CMBS, whereas LiCl was stimulatory. It is concluded that ..beta..-cells resemble erythrocytes in having a permeation path for CMBS that is inhibited by SO/sub 4//sup 2 -/. By analogy with existing models of the erythrocyte membrane, it is suggested that the SO/sub 4//sup 2 -/-sensitive path leads to sulphydryl groups controlling monovalent cationic permeability in ..beta..-cells.

  3. Potential differentiation of islet-like cells from pregnant cow-derived placental stem cells.

    Science.gov (United States)

    Peng, Shao-Yu; Chou, Chien-Wen; Kuo, Yu-Hsuan; Shen, Perng-Chih; Shaw, S W Steven

    2017-06-01

    Type 1 diabetes is an autoimmune disease that destroys islet cells and results in insufficient insulin secretion by pancreatic β-cells. Islet transplantation from donors is an approach used for treating patients with diabetes; however, this therapy is difficult to implement because of the lack of donors. Nevertheless, several stem cells have the potential to differentiate from islet-like cells and enable insulin secretion for treating diabetes in animal models. For example, placenta is considered a waste material and can be harvested noninvasively during delivery without ethical or moral concerns. To date, the differentiation of islet-like cells from cow-derived placental stem cells (CPSCs) has yet to be demonstrated. The investigation of potential differentiation of islet-like cells from CPSCs was conducted by supplementation with nicotinamide, exendin-4, glucose, and poly-d-lysine and was detected through reverse transcription polymerase chain reaction, dithizone staining, and immunocytochemical methods. Our results indicated that CPSCs are established and express mesenchymal stem cell surface antigen markers, such as CD73, CD166, β-integrin, and Oct-4, but not hematopoietic stem cell surface antigen markers, such as CD45. After induction, the CPSCs successfully differentiated into islet-like cells. The CPSC-derived islet-like cells expressed islet cell development-related genes, such as insulin, glucagon, pax-4, Nkx6.1, pax-6, and Fox. Moreover, CPSC-derived islet-like cells can be stained with zinc ions, which are widely distributed in the islet cells and enable insulin secretion. Altogether, islet-like cells have the potential to be differentiated from CPSCs without gene manipulation, and can be used in diabetic animal models in the future for preclinical and drug testing trial investigations. Copyright © 2017. Published by Elsevier B.V.

  4. Methylated trivalent arsenicals are potent inhibitors of glucose stimulated insulin secretion by murine pancreatic islets

    Energy Technology Data Exchange (ETDEWEB)

    Douillet, Christelle [Department of Nutrition, Gillings School of Global Public Health, 2302 MHRC, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7461 (United States); Currier, Jenna [Curriculum in Toxicology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7461 (United States); Saunders, Jesse [Department of Nutrition, Gillings School of Global Public Health, 2302 MHRC, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7461 (United States); Bodnar, Wanda M. [Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7431 (United States); Matoušek, Tomáš [Institute of Analytical Chemistry of the ASCR, v.v.i., Veveří 97, 602 00 Brno (Czech Republic); Stýblo, Miroslav, E-mail: styblo@med.unc.edu [Department of Nutrition, Gillings School of Global Public Health, 2302 MHRC, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7461 (United States)

    2013-02-15

    Epidemiologic evidence has linked chronic exposure to inorganic arsenic (iAs) with an increased prevalence of diabetes mellitus. Laboratory studies have identified several mechanisms by which iAs can impair glucose homeostasis. We have previously shown that micromolar concentrations of arsenite (iAs{sup III}) or its methylated trivalent metabolites, methylarsonite (MAs{sup III}) and dimethylarsinite (DMAs{sup III}), inhibit the insulin-activated signal transduction pathway, resulting in insulin resistance in adipocytes. Our present study examined effects of the trivalent arsenicals on insulin secretion by intact pancreatic islets isolated from C57BL/6 mice. We found that 48-hour exposures to low subtoxic concentrations of iAs{sup III}, MAs{sup III} or DMAs{sup III} inhibited glucose-stimulated insulin secretion (GSIS), but not basal insulin secretion. MAs{sup III} and DMAs{sup III} were more potent than iAs{sup III} as GSIS inhibitors with estimated IC{sub 50} ≤ 0.1 μM. The exposures had little or no effects on insulin content of the islets or on insulin expression, suggesting that trivalent arsenicals interfere with mechanisms regulating packaging of the insulin transport vesicles or with translocation of these vesicles to the plasma membrane. Notably, the inhibition of GSIS by iAs{sup III}, MAs{sup III} or DMAs{sup III} could be reversed by a 24-hour incubation of the islets in arsenic-free medium. These results suggest that the insulin producing pancreatic β-cells are among the targets for iAs exposure and that the inhibition of GSIS by low concentrations of the methylated metabolites of iAs may be the key mechanism of iAs-induced diabetes. - Highlights: ► Trivalent arsenicals inhibit glucose stimulated insulin secretion by pancreatic islets. ► MAs{sup III} and DMAs{sup III} are more potent inhibitors than arsenite with IC{sub 50} ∼ 0.1 μM. ► The arsenicals have little or no effects on insulin expression in pancreatic islets. ► The inhibition of

  5. Methylated trivalent arsenicals are potent inhibitors of glucose stimulated insulin secretion by murine pancreatic islets

    International Nuclear Information System (INIS)

    Douillet, Christelle; Currier, Jenna; Saunders, Jesse; Bodnar, Wanda M.; Matoušek, Tomáš; Stýblo, Miroslav

    2013-01-01

    Epidemiologic evidence has linked chronic exposure to inorganic arsenic (iAs) with an increased prevalence of diabetes mellitus. Laboratory studies have identified several mechanisms by which iAs can impair glucose homeostasis. We have previously shown that micromolar concentrations of arsenite (iAs III ) or its methylated trivalent metabolites, methylarsonite (MAs III ) and dimethylarsinite (DMAs III ), inhibit the insulin-activated signal transduction pathway, resulting in insulin resistance in adipocytes. Our present study examined effects of the trivalent arsenicals on insulin secretion by intact pancreatic islets isolated from C57BL/6 mice. We found that 48-hour exposures to low subtoxic concentrations of iAs III , MAs III or DMAs III inhibited glucose-stimulated insulin secretion (GSIS), but not basal insulin secretion. MAs III and DMAs III were more potent than iAs III as GSIS inhibitors with estimated IC 50 ≤ 0.1 μM. The exposures had little or no effects on insulin content of the islets or on insulin expression, suggesting that trivalent arsenicals interfere with mechanisms regulating packaging of the insulin transport vesicles or with translocation of these vesicles to the plasma membrane. Notably, the inhibition of GSIS by iAs III , MAs III or DMAs III could be reversed by a 24-hour incubation of the islets in arsenic-free medium. These results suggest that the insulin producing pancreatic β-cells are among the targets for iAs exposure and that the inhibition of GSIS by low concentrations of the methylated metabolites of iAs may be the key mechanism of iAs-induced diabetes. - Highlights: ► Trivalent arsenicals inhibit glucose stimulated insulin secretion by pancreatic islets. ► MAs III and DMAs III are more potent inhibitors than arsenite with IC 50 ∼ 0.1 μM. ► The arsenicals have little or no effects on insulin expression in pancreatic islets. ► The inhibition of insulin secretion by arsenite, MAs III or DMAs III is reversible. ► Thus

  6. Factors influencing the adequacy of microencapsulation of rat pancreatic islets.

    Science.gov (United States)

    De Vos, P; De Haan, B; Wolters, G H; Van Schilfgaarde, R

    1996-10-15

    The observation that only a portion of all alginate-polylysine microcapsules are overgrown after implantation suggests that physical imperfections of individual capsules, rather than the chemical composition of the material applied, are responsible for inducing insufficient biocompatibility and thereby fibrotic overgrowth of those capsules. We recently developed a lectin binding assay that allows for quantifying the portion of inadequately encapsulated islets, and demonstrated that inadequately encapsulated islets induce a fibrotic response associated with graft failure. The present study investigates factors influencing the adequacy of encapsulation of pancreatic islets. We applied our lectin binding assay and found that the number of inadequate, and particularly incomplete, capsules is influenced by the following factors. (1) A capsule diameter of 800 micrometers is associated with a lower percentage of inadequate capsules than smaller (500 micrometers and 600 micrometers) or larger (1800 micrometers) capsules. (2) A high rather than low guluronic acid content of the alginate is associated with a lower percentage of inadequate capsules. This can be explained, at least in part, by smaller ranges of swelling and subsequent shrinkage during the encapsulation procedure. (3) An increase in viscosity caused by applying a higher alginate concentration compensates for a low guluronic acid content. This effect of increased viscosity cannot be explained by a reduced range of swelling and shrinkage during the encapsulation procedure. We conclude that alginates with a high guluronic acid content and a viscosity near the filtration limit are preferable in order to minimize the number of inadequate capsules.

  7. Decrease of glucose-induced insulin secretion of rat pancreatic islets after irradiation in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Heinzmann, D; Nadrowitz, R; Besch, W; Schmidt, W; Hahn, H J [Zentralinstitut fuer Diabetes, Karlsburg (German Democratic Republic); Ernst-Moritz-Arndt-Universitaet, Greifswald (German Democratic Republic). Radiologische Klinik)

    1983-01-01

    In vitro irradiation of rat pancreatic islets up to a dose of 2.5 Gy did neither alter glucose- nor isobutylmethyl xanthine (IBMX)-induced insulin secretion. Insulin as well as glucagon content of irradiated islets corresponded to that of the control tissue. So it was in islets irradiated with 25 Gy which were characterized by a decreased insulin secretion in the presence of glucose and IBMX, respectively. There was no indication of an enhanced hormone output in the radiation medium and it is to be suggested that higher radiation doses affect the insulin release of pancreatic islets in vitro. This must be taken into consideration for radioimmunosuppression experiments.

  8. Beating diabetes: strategies to improve pancreatic islet transplantation

    NARCIS (Netherlands)

    Hilderink, J.

    2013-01-01

    Type 1 diabetes is a chronic disease that is caused by nearly complete destruction of insulin producing beta-cells in the islets of Langerhans, affecting approximately 25 million people worldwide. Prior to the discovery of insulin, diabetes most certainly led to death. To date, patients with type 1

  9. Effect of alcohol on insulin secretion and viability of human pancreatic islets

    Directory of Open Access Journals (Sweden)

    Nikolić Dragan

    2017-01-01

    Full Text Available Introduction/Objective. There are controversial data in the literature on the topic of effects of alcohol on insulin secretion, apoptosis, and necrosis of the endocrine and exocrine pancreas. The goal of this research was to determine how alcohol affects the insulin secretion and viability of human adult pancreatic islets in vitro during a seven-day incubation. Methods. Human pancreatic tissue was digested with Collagenase XI, using a non-automated method. Cultures were incubated in Roswell Park Memorial Institute (RPMI medium containing alcohol (10 μl of alcohol in 100 ml of medium. Insulin stimulation index (SI and viability of the islets were determined on the first, third, and seventh day of cultivation. Results. Analysis of the viability of the islets showed that there wasn’t significant difference between the control and the test group. In the test group, viability of the cultures declined with the time of incubation. SI of the test group was higher compared to the control group, by 50% and 25% on the first and third day of cultivation, respectively. On the seventh day, insulin secretion was reduced by 25%. The difference was not statistically significant (p > 0.05. In the test group, significant decline in insulin secretion was found on the third and seventh day of incubation (p ≤ 0.05. Conclusion. Alcohol can increase or decrease insulin secretion of islets cultures, which may result in an inadequate response of pancreatic β-cells to blood glucose, leading to insulin resistance, and increased risk of developing type 2 diabetes. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 41002

  10. Improving pancreatic islet in vitro functionality and transplantation efficiency by using heparin mimetic peptide nanofiber gels.

    Science.gov (United States)

    Uzunalli, Gozde; Tumtas, Yasin; Delibasi, Tuncay; Yasa, Oncay; Mercan, Sercan; Guler, Mustafa O; Tekinay, Ayse B

    2015-08-01

    Pancreatic islet transplantation is a promising treatment for type 1 diabetes. However, viability and functionality of the islets after transplantation are limited due to loss of integrity and destruction of blood vessel networks. Thus, it is important to provide a proper mechanically and biologically supportive environment for enhancing both in vitro islet culture and transplantation efficiency. Here, we demonstrate that heparin mimetic peptide amphiphile (HM-PA) nanofibrous network is a promising platform for these purposes. The islets cultured with peptide nanofiber gel containing growth factors exhibited a similar glucose stimulation index as that of the freshly isolated islets even after 7 days. After transplantation of islets to STZ-induced diabetic rats, 28 day-long monitoring displayed that islets that were transplanted in HM-PA nanofiber gels maintained better blood glucose levels at normal levels compared to the only islet transplantation group. In addition, intraperitoneal glucose tolerance test revealed that animals that were transplanted with islets within peptide gels showed a similar pattern with the healthy control group. Histological assessment showed that islets transplanted within peptide nanofiber gels demonstrated better islet integrity due to increased blood vessel density. This work demonstrates that using the HM-PA nanofiber gel platform enhances the islets function and islet transplantation efficiency both in vitro and in vivo. Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  11. Activation of NLRP3 Inflammasome by Advanced Glycation End Products Promotes Pancreatic Islet Damage

    Directory of Open Access Journals (Sweden)

    Xiang Kong

    2017-01-01

    Full Text Available Accumulation of advanced glycation end products (AGEs contributes to ageing and age-related diseases, especially type 2 diabetes. The NLRP3 inflammasome, as a vital component of the innate immune system, is implicated in the pathogenesis of type 2 diabetes. However, the role of the NLRP3 inflammasome in AGE-induced pancreatic islet damage remains largely unclear. Results showed that administration of AGEs (120 mg/kg for 6 weeks in C57BL/6J mice induced an abnormal response to glucose (as measured by glucose tolerance and insulin release, pancreatic β-cell ultrastructural lesion, and cell death. These effects were associated with an excessive superoxide anion level, significant increased protein expression levels for NADPH oxidase 2 (NOX2, thioredoxin-interacting protein (TXNIP, NLRP3, and cleaved IL-1β, enhanced caspase-1 activity, and a significant increase in the levels of TXNIP–NLRP3 protein interaction. Ablation of the NLRP3 inflammasome or treatment with antioxidant N-acetyl-cysteine (NAC clearly ameliorated these effects. In conclusion, our results reveal a possible mechanism for AGE-induced pancreatic islet damage upon NLRP3 inflammasome activation.

  12. Total pancreatectomy and islet autotransplantation in children for chronic pancreatitis: indication, surgical techniques, postoperative management, and long-term outcomes.

    Science.gov (United States)

    Chinnakotla, Srinath; Bellin, Melena D; Schwarzenberg, Sarah J; Radosevich, David M; Cook, Marie; Dunn, Ty B; Beilman, Gregory J; Freeman, Martin L; Balamurugan, A N; Wilhelm, Josh; Bland, Barbara; Jimenez-Vega, Jose M; Hering, Bernhard J; Vickers, Selwyn M; Pruett, Timothy L; Sutherland, David E R

    2014-07-01

    Describe the surgical technique, complications, and long-term outcomes of total pancreatectomy and islet autotransplantation (TP-IAT) in a large series of pediatric patients. Surgical management of childhood pancreatitis is not clear; partial resection or drainage procedures often provide transient pain relief, but long-term recurrence is common due to the diffuse involvement of the pancreas. Total pancreatectomy (TP) removes the source of the pain, whereas islet autotransplantation (IAT) potentially can prevent or minimize TP-related diabetes. Retrospective review of 75 children undergoing TP-IAT for chronic pancreatitis who had failed medical, endoscopic, or surgical treatment between 1989 and 2012. Pancreatitis pain and the severity of pain statistically improved in 90% of patients after TP-IAT (P Puestow procedure (P = 0.018), lower body surface area (P = 0.048), higher islet equivalents (IEQ) per kilogram body weight (P = 0.001), and total IEQ (100,000) (P = 0.004) were associated with insulin independence. By multivariate analysis, 3 factors were associated with insulin independence after TP-IAT: (1) male sex, (2) lower body surface area, and (3) higher total IEQ per kilogram body weight. Total IEQ (100,000) was the single factor most strongly associated with insulin independence (odds ratio = 2.62; P < 0.001). Total pancreatectomy and islet autotransplantation provides sustained pain relief and improved quality of life. The β-cell function is dependent on islet yield. Total pancreatectomy and islet autotransplantation is an effective therapy for children with painful pancreatitis that failed medical and/or endoscopic management.

  13. A VERSATILE ALGINATE DROPLET GENERATOR APPLICABLE FOR MICROENCAPSULATION OF PANCREATIC-ISLETS

    NARCIS (Netherlands)

    WOLTERS, GHJ; FRITSCHY, WM; GERRITS, D; VANSCHILFAGAARDE, R

    1992-01-01

    Alginate beads for immunoisolation of pancreatic islets by microencapsulation should be small, smooth, and spherical in order to ensure that around the islets a strong alginate-polylysine-alginate capsule will be formed with optimal biocompatibility and diffusion of nutrients and hormones. However,

  14. Engineering quadrupole magnetic flow sorting for the isolation of pancreatic islets

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, David J. [IKOtech, LLC, 3130 Highland Avenue, 3rd Floor, Cincinnati, OH 45219-2374 (United States)]. E-mail: David.Kennedy@IKOtech.com; Todd, Paul [SHOT, Inc., Greenville, IN (United States); Logan, Sam [SHOT, Inc., Greenville, IN (United States); Becker, Matthew [SHOT, Inc., Greenville, IN (United States); Papas, Klearchos K. [Diabetes Institute for Immunology and Transplantation, University of Minnesota, Minneapolis, MN (United States); Moore, Lee R. [Biomedical Engineering Department, Cleveland Clinic Foundation, Cleveland, OH (United States)

    2007-04-15

    Quadrupole magnetic flow sorting (QMS) is being adapted from the separation of suspensions of single cells (<15 {mu}m) to the isolation of pancreatic islets (150-350 {mu}m) for transplant. To achieve this goal, the critical QMS components have been modeled and engineered to optimize the separation process. A flow channel has been designed, manufactured, and tested. The quadrupole magnet assembly has been designed and verified by finite element analysis. Pumps have been selected and verified by test. Test data generated from the pumps and flow channel demonstrate that the fabricated channel and peristaltic pumps fulfill the requirements of successful QMS separation.

  15. Engineering quadrupole magnetic flow sorting for the isolation of pancreatic islets

    International Nuclear Information System (INIS)

    Kennedy, David J.; Todd, Paul; Logan, Sam; Becker, Matthew; Papas, Klearchos K.; Moore, Lee R.

    2007-01-01

    Quadrupole magnetic flow sorting (QMS) is being adapted from the separation of suspensions of single cells (<15 μm) to the isolation of pancreatic islets (150-350 μm) for transplant. To achieve this goal, the critical QMS components have been modeled and engineered to optimize the separation process. A flow channel has been designed, manufactured, and tested. The quadrupole magnet assembly has been designed and verified by finite element analysis. Pumps have been selected and verified by test. Test data generated from the pumps and flow channel demonstrate that the fabricated channel and peristaltic pumps fulfill the requirements of successful QMS separation

  16. Pancreatic islet allograft in spleen with immunosuppression with cyclosporine. Experimental model in dogs.

    Science.gov (United States)

    Waisberg, Jaques; Neff, Charles Benjamin; Waisberg, Daniel Reis; Germini, Demetrius; Gonçalves, José Eduardo; Zanotto, Arnaldo; Speranzini, Manlio Basilio

    2011-01-01

    To study the functional behavior of the allograft with immunosuppression of pancreatic islets in the spleen. Five groups of 10 Mongrel dogs were used: Group A (control) underwent biochemical tests; Group B underwent total pancreatectomy; Group C underwent total pancreatectomy and pancreatic islet autotransplant in the spleen; Group D underwent pancreatic islet allograft in the spleen without immunosuppressive therapy; Group E underwent pancreatic islet allograft in the spleen and immunosuppression with cyclosporine. All of the animals with grafts received pancreatic islets prepared by the mechanical-enzymatic method - stationary collagenase digestion and purification with dextran discontinuous density gradient, implanted in the spleen. The animals with autotransplant and those with allografts with immunosuppression that became normoglycemic showed altered results of intravenous tolerance glucose (p < 0.001) and peripheral and splenic vein plasmatic insulin levels were significantly lower (p < 0.001) in animals that had allografts with immunosuppression than in those with just autotransplants. In the animals with immunosuppression with cyclosporine subjected to allograft of pancreatic islets prepared with the mechanical-enzymatic preparation method (stationary collagenase digestion and purification with dextran discontinuous density gradient), the production of insulin is decreased and the response to intravenous glucose is altered.

  17. Modular tissue engineering for the vascularization of subcutaneously transplanted pancreatic islets.

    Science.gov (United States)

    Vlahos, Alexander E; Cober, Nicholas; Sefton, Michael V

    2017-08-29

    The transplantation of pancreatic islets, following the Edmonton Protocol, is a promising treatment for type I diabetics. However, the need for multiple donors to achieve insulin independence reflects the large loss of islets that occurs when islets are infused into the portal vein. Finding a less hostile transplantation site that is both minimally invasive and able to support a large transplant volume is necessary to advance this approach. Although the s.c. site satisfies both these criteria, the site is poorly vascularized, precluding its utility. To address this problem, we demonstrate that modular tissue engineering results in an s.c. vascularized bed that enables the transplantation of pancreatic islets. In streptozotocin-induced diabetic SCID/beige mice, the injection of 750 rat islet equivalents embedded in endothelialized collagen modules was sufficient to restore and maintain normoglycemia for 21 days; the same number of free islets was unable to affect glucose levels. Furthermore, using CLARITY, we showed that embedded islets became revascularized and integrated with the host's vasculature, a feature not seen in other s.c. Collagen-embedded islets drove a small (albeit not significant) shift toward a proangiogenic CD206 + MHCII - (M2-like) macrophage response, which was a feature of module-associated vascularization. While these results open the potential for using s.c. islet delivery as a treatment option for type I diabetes, the more immediate benefit may be for the exploration of revascularized islet biology.

  18. Melatonin and Pancreatic Islets: Interrelationships between Melatonin, Insulin and Glucagon

    Science.gov (United States)

    Peschke, Elmar; Bähr, Ina; Mühlbauer, Eckhard

    2013-01-01

    The pineal hormone melatonin exerts its influence in the periphery through activation of two specific trans-membrane receptors: MT1 and MT2. Both isoforms are expressed in the islet of Langerhans and are involved in the modulation of insulin secretion from β-cells and in glucagon secretion from α-cells. De-synchrony of receptor signaling may lead to the development of type 2 diabetes. This notion has recently been supported by genome-wide association studies identifying particularly the MT2 as a risk factor for this rapidly spreading metabolic disturbance. Since melatonin is secreted in a clearly diurnal fashion, it is safe to assume that it also has a diurnal impact on the blood-glucose-regulating function of the islet. This factor has hitherto been underestimated; the disruption of diurnal signaling within the islet may be one of the most important mechanisms leading to metabolic disturbances. The study of melatonin–insulin interactions in diabetic rat models has revealed an inverse relationship: an increase in melatonin levels leads to a down-regulation of insulin secretion and vice versa. Elucidation of the possible inverse interrelationship in man may open new avenues in the therapy of diabetes. PMID:23535335

  19. Morphologic and morphometric evaluation of pancreatic islets in chronic Chagas' disease

    Directory of Open Access Journals (Sweden)

    Saldanha João Carlos

    2001-01-01

    Full Text Available PURPOSE: Hyperglycemia and abnormal glucose tolerance tests observed in some patients with chronic Chagas' disease suggest the possibility of morphological changes in pancreatic islets and/or denervation. The purpose of this study was to describe the morphology and morphometry of pancreatic islets in chronic Chagas' disease. METHODS: Morphologic and computerized morphometric studies were performed in fragments of the head, body, and tail regions of the pancreas obtained at necropsies of 8 normal controls and 17 patients with chronic Chagas' disease: 8 with the digestive form (Megas and 9 with the congestive heart failure form. RESULTS: The Megas group had a larger (p < 0.05 pancreatic islet area in the tail of the pancreas (10649.3 ± 4408.8 µm² than the normal control (9481.8 ± 3242.4 µm² and congestive heart failure (9475.1 ± 2104.9 µm² groups; likewise, the density of the pancreatic islets (PI was greater (1.2 ± 0.7 vs. 0.9 ± 0.6 vs. 1.9 ± 1.0 PI/mm², respectively. In the tail region of the pancreas of patients with the Megas form, there was a significant and positive correlation (r = +0.73 between the area and density of pancreatic islets. Discrete fibrosis and leukocytic infiltrates were found in pancreatic ganglia and pancreatic islets of the patients with Chagas' disease. Trypanosoma cruzi nests were not observed in the examined sections. Individuals with the Megas form of Chagas' disease showed increased area and density of pancreatic islets in the tail of the pancreas. CONCLUSION: The observed morphometric and morphologic alterations are consistent with functional changes in the pancreas, including glycemia and insulin disturbances.

  20. Pancreatic Islet Protein Complexes and Their Dysregulation in Type 2 Diabetes

    DEFF Research Database (Denmark)

    Pedersen, Helle Krogh; Gudmundsdottir, Valborg; Brunak, Søren

    2017-01-01

    Type 2 diabetes (T2D) is a complex disease that involves multiple genes. Numerous risk loci have already been associated with T2D, although many susceptibility genes remain to be identified given heritability estimates. Systems biology approaches hold potential for discovering novel T2D genes...... by considering their biological context, such as tissue-specific protein interaction partners. Pancreatic islets are a key T2D tissue and many of the known genetic risk variants lead to impaired islet function, hence a better understanding of the islet-specific dysregulation in the disease-state is essential...... to unveil the full potential of person-specific profiles. Here we identify 3,692 overlapping pancreatic islet protein complexes (containing 10,805 genes) by integrating islet gene and protein expression data with protein interactions. We found 24 of these complexes to be significantly enriched for genes...

  1. Sustained beta-cell dysfunction but normalized islet mass in aged thrombospondin-1 deficient mice.

    Directory of Open Access Journals (Sweden)

    Carl Johan Drott

    Full Text Available Pancreatic islet endothelial cells have in recent years been shown to support beta-cell mass and function by paracrine interactions. Recently, we identified an islets endothelial-specific glycoprotein, thrombospondin-1 (TSP-1, that showed to be of importance for islet angiogenesis and beta-cell function in young mice. The present study aimed to investigate long-term consequences for islet morphology and beta-cell function of TSP-1 deficiency. Islet and beta-cell mass were observed increased at 10-12 weeks of age in TSP-1 deficient mice, but were normalized before 16 weeks of age when compared to wild-type controls. Islet vascularity was normal in 10-12 and 16-week-old TSP-1 deficient animals, whereas islets of one-year-old animals lacking TSP-1 were hypervascular. Beta-cell dysfunction in TSP-1 deficient animals was present at similar magnitudes between 10-12 and 52 weeks of age, as evaluated by glucose tolerance tests. The insulin secretion capacity in vivo of islets in one-year-old TSP-1 deficient animals was only ∼15% of that in wild-type animals. Using a transplantation model, we reconstituted TSP-1 in adult TSP-deficient islets. In contrast to neonatal TSP-1 deficient islets that we previously reported to regain function after TSP-1 reconstitution, adult islets failed to recover. We conclude that TSP-1 deficiency in islets causes changing vascular and endocrine morphological alterations postnatally, but is coupled to a chronic beta-cell dysfunction. The beta-cell dysfunction induced by TSP-1 deficiency is irreversible if not substituted early in life.

  2. The Beta Cell in Its Cluster: Stochastic Graphs of Beta Cell Connectivity in the Islets of Langerhans.

    Directory of Open Access Journals (Sweden)

    Deborah A Striegel

    2015-08-01

    Full Text Available Pancreatic islets of Langerhans consist of endocrine cells, primarily α, β and δ cells, which secrete glucagon, insulin, and somatostatin, respectively, to regulate plasma glucose. β cells form irregular locally connected clusters within islets that act in concert to secrete insulin upon glucose stimulation. Due to the central functional significance of this local connectivity in the placement of β cells in an islet, it is important to characterize it quantitatively. However, quantification of the seemingly stochastic cytoarchitecture of β cells in an islet requires mathematical methods that can capture topological connectivity in the entire β-cell population in an islet. Graph theory provides such a framework. Using large-scale imaging data for thousands of islets containing hundreds of thousands of cells in human organ donor pancreata, we show that quantitative graph characteristics differ between control and type 2 diabetic islets. Further insight into the processes that shape and maintain this architecture is obtained by formulating a stochastic theory of β-cell rearrangement in whole islets, just as the normal equilibrium distribution of the Ornstein-Uhlenbeck process can be viewed as the result of the interplay between a random walk and a linear restoring force. Requiring that rearrangements maintain the observed quantitative topological graph characteristics strongly constrained possible processes. Our results suggest that β-cell rearrangement is dependent on its connectivity in order to maintain an optimal cluster size in both normal and T2D islets.

  3. The Beta Cell in Its Cluster: Stochastic Graphs of Beta Cell Connectivity in the Islets of Langerhans.

    Science.gov (United States)

    Striegel, Deborah A; Hara, Manami; Periwal, Vipul

    2015-08-01

    Pancreatic islets of Langerhans consist of endocrine cells, primarily α, β and δ cells, which secrete glucagon, insulin, and somatostatin, respectively, to regulate plasma glucose. β cells form irregular locally connected clusters within islets that act in concert to secrete insulin upon glucose stimulation. Due to the central functional significance of this local connectivity in the placement of β cells in an islet, it is important to characterize it quantitatively. However, quantification of the seemingly stochastic cytoarchitecture of β cells in an islet requires mathematical methods that can capture topological connectivity in the entire β-cell population in an islet. Graph theory provides such a framework. Using large-scale imaging data for thousands of islets containing hundreds of thousands of cells in human organ donor pancreata, we show that quantitative graph characteristics differ between control and type 2 diabetic islets. Further insight into the processes that shape and maintain this architecture is obtained by formulating a stochastic theory of β-cell rearrangement in whole islets, just as the normal equilibrium distribution of the Ornstein-Uhlenbeck process can be viewed as the result of the interplay between a random walk and a linear restoring force. Requiring that rearrangements maintain the observed quantitative topological graph characteristics strongly constrained possible processes. Our results suggest that β-cell rearrangement is dependent on its connectivity in order to maintain an optimal cluster size in both normal and T2D islets.

  4. Decreased 11β-Hydroxysteroid Dehydrogenase 1 Level and Activity in Murine Pancreatic Islets Caused by Insulin-Like Growth Factor I Overexpression.

    Directory of Open Access Journals (Sweden)

    Subrata Chowdhury

    Full Text Available We have reported a high expression of IGF-I in pancreatic islet β-cells of transgenic mice under the metallothionein promoter. cDNA microarray analysis of the islets revealed that the expression of 82 genes was significantly altered compared to wild-type mice. Of these, 11β-hydroxysteroid dehydrogenase 1 (11β-HSD1, which is responsible for the conversion of inert cortisone (11-dehydrocorticosterone, DHC in rodents to active cortisol (corticosterone in the liver and adipose tissues, has not been identified previously as an IGF-I target in pancreatic islets. We characterized the changes in its protein level, enzyme activity and glucose-stimulated insulin secretion. In freshly isolated islets, the level of 11β-HSD1 protein was significantly lower in MT-IGF mice. Using dual-labeled immunofluorescence, 11β-HSD1 was observed exclusively in glucagon-producing, islet α-cells but at a lower level in transgenic vs. wild-type animals. MT-IGF islets also exhibited reduced enzymatic activities. Dexamethasone (DEX and DHC inhibited glucose-stimulated insulin secretion from freshly isolated islets of wild-type mice. In the islets of MT-IGF mice, 48-h pre-incubation of DEX caused a significant decrease in insulin release, while the effect of DHC was largely blunted consistent with diminished 11β-HSD1 activity. In order to establish the function of intracrine glucocorticoids, we overexpressed 11β-HSD1 cDNA in MIN6 insulinoma cells, which together with DHC caused apoptosis and a significant decrease in proliferation. Both effects were abolished with the treatment of an 11β-HSD1 inhibitor. Our results demonstrate an inhibitory effect of IGF-I on 11β-HSD1 expression and activity within the pancreatic islets, which may mediate part of the IGF-I effects on cell proliferation, survival and insulin secretion.

  5. Experimental evaluation and computational modeling of the effects of encapsulation on the time-profile of glucose-stimulated insulin release of pancreatic islets.

    Science.gov (United States)

    Buchwald, Peter; Cechin, Sirlene R; Weaver, Jessica D; Stabler, Cherie L

    2015-03-28

    In type 1 diabetic patients, who have lost their ability to produce insulin, transplantation of pancreatic islet cells can normalize metabolic control in a manner that is not achievable with exogenous insulin. To be successful, this procedure has to address the problems caused by the immune and autoimmune responses to the graft. Islet encapsulation using various techniques and materials has been and is being extensively explored as a possible approach. Within this framework, it is of considerable interest to characterize the effect encapsulation has on the insulin response of pancreatic islets. To improve our ability to quantitatively describe the glucose-stimulated insulin release (GSIR) of pancreatic islets in general and of micro-encapsulated islets in particular, we performed dynamic perifusion experiments with frequent sampling. We used unencapsulated and microencapsulated murine islets in parallel and fitted the results with a complex local concentration-based finite element method (FEM) computational model. The high-resolution dynamic perifusion experiments allowed good characterization of the first-phase and second-phase insulin secretion, and we observed a slightly delayed and blunted first-phase insulin response for microencapsulated islets when compared to free islets. Insulin secretion profiles of both free and encapsulated islets could be fitted well by a COMSOL Multiphysics model that couples hormone secretion and nutrient consumption kinetics with diffusive and convective transport. This model, which was further validated and calibrated here, can be used for arbitrary geometries and glucose stimulation sequences and is well suited for the quantitative characterization of the insulin response of cultured, perifused, transplanted, or encapsulated islets. The present high-resolution GSIR experiments allowed for direct characterization of the effect microencapsulation has on the time-profile of insulin secretion. The multiphysics model, further validated

  6. Developmental programming of polycystic ovary syndrome (PCOS): prenatal androgens establish pancreatic islet α/β cell ratio and subsequent insulin secretion.

    Science.gov (United States)

    Ramaswamy, S; Grace, C; Mattei, A A; Siemienowicz, K; Brownlee, W; MacCallum, J; McNeilly, A S; Duncan, W C; Rae, M T

    2016-06-06

    Exogenous androgenic steroids applied to pregnant sheep programmes a PCOS-like phenotype in female offspring. Via ultrasound guidance we applied steroids directly to ovine fetuses at d62 and d82 of gestation, and examined fetal (day 90 gestation) and postnatal (11 months old) pancreatic structure and function. Of three classes of steroid agonists applied (androgen - Testosterone propionate (TP), estrogen - Diethystilbesterol (DES) and glucocorticoid - Dexamethasone (DEX)), only androgens (TP) caused altered pancreatic development. Beta cell numbers were significantly elevated in prenatally androgenised female fetuses (P = 0.03) (to approximately the higher numbers found in male fetuses), whereas alpha cell counts were unaffected, precipitating decreased alpha:beta cell ratios in the developing fetal pancreas (P = 0.001), sustained into adolescence (P = 0.0004). In adolescence basal insulin secretion was significantly higher in female offspring from androgen-excess pregnancies (P = 0.045), and an exaggerated, hyperinsulinaemic response to glucose challenge (P = 0.0007) observed, whereas prenatal DES or DEX treatment had no effects upon insulin secretion. Postnatal insulin secretion correlated with beta cell numbers (P = 0.03). We conclude that the pancreas is a primary locus of androgenic stimulation during development, giving rise to postnatal offspring whose pancreas secreted excess insulin due to excess beta cells in the presence of a normal number of alpha cells.

  7. Chronology of Islet Differentiation Revealed By Temporal Cell Labeling

    Science.gov (United States)

    Miyatsuka, Takeshi; Li, Zhongmei; German, Michael S.

    2009-01-01

    OBJECTIVE Neurogenin 3 plays a pivotal role in pancreatic endocrine differentiation. Whereas mouse models expressing reporters such as eGFP or LacZ under the control of the Neurog3 gene enable us to label cells in the pancreatic endocrine lineage, the long half-life of most reporter proteins makes it difficult to distinguish cells actively expressing neurogenin 3 from differentiated cells that have stopped transcribing the gene. RESEARCH DESIGN AND METHODS In order to separate the transient neurogenin 3 –expressing endocrine progenitor cells from the differentiating endocrine cells, we developed a mouse model (Ngn3-Timer) in which DsRed-E5, a fluorescent protein that shifts its emission spectrum from green to red over time, was expressed transgenically from the NEUROG3 locus. RESULTS In the Ngn3-Timer embryos, green-dominant cells could be readily detected by microscopy or flow cytometry and distinguished from green/red double-positive cells. When fluorescent cells were sorted into three different populations by a fluorescence-activated cell sorter, placed in culture, and then reanalyzed by flow cytometry, green-dominant cells converted to green/red double-positive cells within 6 h. The sorted cell populations were then used to determine the temporal patterns of expression for 145 transcriptional regulators in the developing pancreas. CONCLUSIONS The precise temporal resolution of this model defines the narrow window of neurogenin 3 expression in islet progenitor cells and permits sequential analyses of sorted cells as well as the testing of gene regulatory models for the differentiation of pancreatic islet cells. PMID:19478145

  8. Curcumin enhances recovery of pancreatic islets from cellular stress induced inflammation and apoptosis in diabetic rats

    International Nuclear Information System (INIS)

    Rashid, Kahkashan; Sil, Parames C.

    2015-01-01

    The phytochemical, curcumin, has been reported to play many beneficial roles. However, under diabetic conditions, the detail mechanism of its beneficial action in the glucose homeostasis regulatory organ, pancreas, is poorly understood. The present study has been designed and carried out to explore the role of curcumin in the pancreatic tissue of STZ induced and cellular stress mediated diabetes in eight weeks old male Wistar rats. Diabetes was induced with a single intraperitoneal dose of STZ (65 mg/kg body weight). Post to diabetes induction, animals were treated with curcumin at a dose of 100 mg/kg body weight for eight weeks. Underlying molecular and cellular mechanism was determined using various biochemical assays, DNA fragmentation, FACS, histology, immunoblotting and ELISA. Treatment with curcumin reduced blood glucose level, increased plasma insulin and mitigated oxidative stress related markers. In vivo and in vitro experimental results revealed increased levels of proinflammatory cytokines (TNF-α, IL1-β and IFN-γ), reduced level of cellular defense proteins (Nrf-2 and HO-1) and glucose transporter (GLUT-2) along with enhanced levels of signaling molecules of ER stress dependent and independent apoptosis (cleaved Caspase-12/9/8/3) in STZ administered group. Treatment with curcumin ameliorated all the adverse changes and helps the organ back to its normal physiology. Results suggest that curcumin protects pancreatic beta-cells by attenuating inflammatory responses, and inhibiting ER/mitochondrial dependent and independent pathways of apoptosis and crosstalk between them. This uniqueness and absence of any detectable adverse effect proposes the possibility of using this molecule as an effective protector in the cellular stress mediated diabetes mellitus. - Highlights: • STZ induced cellular stress plays a vital role in pancreatic dysfunction. • Cellular stress causes inflammation, pancreatic islet cell death and diabetes. • Deregulation of Nrf-2

  9. Curcumin enhances recovery of pancreatic islets from cellular stress induced inflammation and apoptosis in diabetic rats

    Energy Technology Data Exchange (ETDEWEB)

    Rashid, Kahkashan; Sil, Parames C., E-mail: parames@jcbose.ac.in

    2015-02-01

    The phytochemical, curcumin, has been reported to play many beneficial roles. However, under diabetic conditions, the detail mechanism of its beneficial action in the glucose homeostasis regulatory organ, pancreas, is poorly understood. The present study has been designed and carried out to explore the role of curcumin in the pancreatic tissue of STZ induced and cellular stress mediated diabetes in eight weeks old male Wistar rats. Diabetes was induced with a single intraperitoneal dose of STZ (65 mg/kg body weight). Post to diabetes induction, animals were treated with curcumin at a dose of 100 mg/kg body weight for eight weeks. Underlying molecular and cellular mechanism was determined using various biochemical assays, DNA fragmentation, FACS, histology, immunoblotting and ELISA. Treatment with curcumin reduced blood glucose level, increased plasma insulin and mitigated oxidative stress related markers. In vivo and in vitro experimental results revealed increased levels of proinflammatory cytokines (TNF-α, IL1-β and IFN-γ), reduced level of cellular defense proteins (Nrf-2 and HO-1) and glucose transporter (GLUT-2) along with enhanced levels of signaling molecules of ER stress dependent and independent apoptosis (cleaved Caspase-12/9/8/3) in STZ administered group. Treatment with curcumin ameliorated all the adverse changes and helps the organ back to its normal physiology. Results suggest that curcumin protects pancreatic beta-cells by attenuating inflammatory responses, and inhibiting ER/mitochondrial dependent and independent pathways of apoptosis and crosstalk between them. This uniqueness and absence of any detectable adverse effect proposes the possibility of using this molecule as an effective protector in the cellular stress mediated diabetes mellitus. - Highlights: • STZ induced cellular stress plays a vital role in pancreatic dysfunction. • Cellular stress causes inflammation, pancreatic islet cell death and diabetes. • Deregulation of Nrf-2

  10. Decrease of glucose-induced insulin secretion of pancreatic rat islets after irradiation in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Heinzmann, D; Nadrowitz, R; Besch, W; Schmidt, W; Hahn, H J

    1983-01-01

    Irradiation of pancreatic rat islets up to a dose of 2.5 Gy did neither alter glucose-nor IBMX-induced insulin secretion studied in vitro. The insulin as well as glucagon content of irradiated islets were similar as in the control tissue. This was also true in islets irradiated with 25 Gy which were characterized by a decreased insulin secretion in the presence of glucose and IBMX, respectively. Since we did not find indications of an enhanced hormone output in the radiation medium, we want to suggest that higher irradiation doses affect insulin release of pancreatic islets in vitro. This observation has to be taken into account for application of radioimmunosuppression for transplantation.

  11. Cooperative function of Pdx1 and Oc1 in multipotent pancreatic progenitors impacts postnatal islet maturation and adaptability.

    Science.gov (United States)

    Kropp, Peter A; Dunn, Jennifer C; Carboneau, Bethany A; Stoffers, Doris A; Gannon, Maureen

    2018-04-01

    The transcription factors pancreatic and duodenal homeobox 1 (Pdx1) and onecut1 (Oc1) are coexpressed in multipotent pancreatic progenitors (MPCs), but their expression patterns diverge in hormone-expressing cells, with Oc1 expression being extinguished in the endocrine lineage and Pdx1 being maintained at high levels in β-cells. We previously demonstrated that cooperative function of these two factors in MPCs is necessary for proper specification and differentiation of pancreatic endocrine cells. In those studies, we observed a persistent decrease in expression of the β-cell maturity factor MafA. We therefore hypothesized that Pdx1 and Oc1 cooperativity in MPCs impacts postnatal β-cell maturation and function. Here our model of Pdx1-Oc1 double heterozygosity was used to investigate the impact of haploinsufficiency for both of these factors on postnatal β-cell maturation, function, and adaptability. Examining mice at postnatal day (P) 14, we observed alterations in pancreatic insulin content in both Pdx1 heterozygotes and double heterozygotes. Gene expression analysis at this age revealed significantly decreased expression of many genes important for glucose-stimulated insulin secretion (e.g., Glut2, Pcsk1/2, Abcc8) exclusively in double heterozygotes. Analysis of P14 islets revealed an increase in the number of mixed islets in double heterozygotes. We predicted that double-heterozygous β-cells would have an impaired ability to respond to stress. Indeed, we observed that β-cell proliferation fails to increase in double heterozygotes in response to either high-fat diet or placental lactogen. We thus report here the importance of cooperation between regulatory factors early in development for postnatal islet maturation and adaptability.

  12. Effect of gamma-irradiation on mouse pancreatic islet-allograft survival

    International Nuclear Information System (INIS)

    Kanai, T.; Porter, J.; Gotoh, M.; Monaco, A.P.; Maki, T.

    1989-01-01

    Elimination or inactivation of lymphoid tissue in the pancreatic islet preparation achieves prolongation of islet-allograft survival. In this study we examined the effect of gamma-irradiation on mouse islet-allograft survival. In a B6AF1 isograft model, irradiation up to 2400 rad did not induce deterioration of islet function over 200 days, but greater doses caused cessation of graft function between 83 and 186 days. When DBA/2 crude islets were transplanted into B6AF1 recipients, all nonirradiated allografts were acutely rejected. Marked prolongation of allograft survival was achieved by islet irradiation with doses between 800 and 12,000 rad. With higher doses, significant numbers of allografts survived beyond the controls, but many lost function between 78 and 180 days, with none surviving greater than 200 days. Irradiation with 16,000 rad caused acute radiation damage. Because most secondary islet allografts in recipient mice that lost primary islet-graft function between 84 and 195 days survived greater than 100 days, late functional loss was probably due to the radiation injury. Combined use of recipient treatment with cyclosporin A and graft irradiation (2400 rad) achieved prolongation of DBA/2 islets in B6AF1 mice

  13. Stem cell-based approach in diabetes and pancreatic cancer management

    Directory of Open Access Journals (Sweden)

    Yi-Zhou Jiang

    2017-01-01

    Full Text Available Stem cell-mediated therapy is a promising strategy for treating pancreatic diseases such as Type-1 diabetes (T1D and pancreatic cancers. Although islet transplantation has been reported to be an effective diabetes therapy, its worldwide application is extremely limited due to the shortage of donor islets and immune rejection problems. Stem cell-based approach for islet neogenesis in vivo could provide a promising alternative source of islets for treating diabetes. On the other hand, targeting the cancer stem cells could be very effective for the treatment of pancreatic cancers. In this review, we focused on the present progress in the field of adult pancreatic stem cells, stem cell-mediated strategies for treating T1D, and pancreatic cancer stem cells, while discussing of the possible challenges involved in them.

  14. Rubidium uptake by mouse pancreatic islets exposed to 6-hydroxydopamine, ninhydrin, or other generators of hydroxyl radicals

    Energy Technology Data Exchange (ETDEWEB)

    Grankvist, K.; Sehlin, J.; Taeljedal, I.-B.

    1986-01-01

    The purpose was to study the toxicity of drugs known to generate free radicals on isolated pancreatic islets. The accumulation of /sup 86/Rb/sup +/ by mouse pancreatic islets was measured in vitro. Exposing the islets to 6-hydroxydopamine, minhydrin, or phenazine methosulphate + NADH inhibited the Rb/sup +/ uptake, whereas paraquat or acetylphenylhydrazine had no effect. This effect of 6-hydroxydopamine was prevented by either of the hydroxyl radical scavengers, sodium benzoate and mannitol, but not by the non-scavenger urea; ninhydrin was partially protected against by mannitol but not by benzoate. Protection against 6-hydroxydopamine was also afforded by D-glucose but not by L-glucose or 3-O-methyl-D-glucose; none of the sugars protected against ninhydrin. In damaging islet beta-cells and in being protected against by D-glucose, 6-hydroxydopamine closely resembles the diabetogenic drug, alloxan. It is suggested that protection against alloxan may involve both glucose metabolism and the interaction of glucose with its membrane-located carrier, while protection against 6-hydroxydopamine appears to be unrelated to the hexose carrier mechanism.

  15. Labeling of pancreatic islets with iron oxide nanoparticles for in vivo detection with magnetic resonance

    Czech Academy of Sciences Publication Activity Database

    Berková, Z.; Jirák, D.; Zacharovová, K.; Kříž, J.; Lodererová, A.; Girman, P.; Koblas, T.; Dovolilová, E.; Vancová, Marie; Hájek, M.; Saudek, F.

    2008-01-01

    Roč. 85, č. 1 (2008), s. 155-159 ISSN 0041-1337 R&D Projects: GA MŠk 2B06175; GA MŠk LN00A065 Institutional research plan: CEZ:AV0Z60220518 Keywords : pancreatic islet s * islet s transplantation * iron nanoparticles Subject RIV: FB - Endocrinology, Diabetology, Metabolism, Nutrition Impact factor: 3.816, year: 2008

  16. Data on morphometric analysis of the pancreatic islets from C57BL/6 and BALB/c mice

    Directory of Open Access Journals (Sweden)

    Thiago Aparecido da Silva

    2016-09-01

    Full Text Available The endocrine portion of the pancreas, which is characterized by pancreatic islets, has been widely investigated among different species. The BALB/c and C57BL/6 mice are extensively used in experimental research, and the morphometric differences in the pancreatic islets of these animals have not been evaluated so far. Thus, our data have a comparative perspective related to the morphometric analysis of area, diameters, circularity, and density of pancreatic islets from BALB/c and C57BL/6 mice. The data presented here are focused to evaluate the differences in morphology of pancreatic islets of two common laboratory mouse strains. Keywords: Pancreatic islets, Morphometry, BALB/c and C57BL/6 mice

  17. Glucose cycling is markedly enhanced in pancreatic islets of obese hyperglycemic mice

    International Nuclear Information System (INIS)

    Khan, A.; Chandramouli, V.; Ostenson, C.G.; Berggren, P.O.; Loew, H.L.; Landau, B.R.; Efendic, S.

    1990-01-01

    Pancreatic islets from fed 7-month old lean and obese hyperglycemic mice (ob/ob) were incubated with 3H2O and 5.5 mM or 16.7 mM glucose. Incorporation of 3H into the medium glucose was taken as the measure of glucose-6-P hydrolysis to glucose. Glucose utilization was measured from the yield of 3H2O from [5-3H]glucose. Only 3-4% of the glucose phosphorylated was dephosphorylated by the lean mouse islets irrespective of the glucose concentration. In contrast, the ob/ob mouse islets at 5.5 mM glucose dephosphorylated 18% of the glucose phosphorylated and 30% at 16.7 mM. Thus, the islets of hyperglycemic mice demonstrate increased glucose cycling as compared to the islets of normoglycemic lean mice

  18. Cloning and functional expression of a human pancreatic islet glucose-transporter cDNA

    International Nuclear Information System (INIS)

    Permutt, M.A.; Koranyi, L.; Keller, K.; Lacy, P.E.; Scharp, D.W.; Mueckler, M.

    1989-01-01

    Previous studies have suggested that pancreatic islet glucose transport is mediated by a high-K m , low-affinity facilitated transporter similar to that expressed in liver. To determine the relationship between islet and liver glucose transporters, liver-type glucose-transporter cDNA clones were isolated from a human liver cDNA library. The liver-type glucose-transporter cDNA clone hybridized to mRNA transcripts of the same size in human liver and pancreatic islet RNA. A cDNA library was prepared from purified human pancreatic islet tissue and screened with human liver-type glucose-transporter cDNA. The authors isolated two overlapping cDNA clones encompassing 2600 base pairs, which encode a pancreatic islet protein identical in sequence to that of the putative liver-type glucose-transporter protein. Xenopus oocytes injected with synthetic mRNA transcribed from a full-length cDNA construct exhibited increased uptake of 2-deoxyglucose, confirming the functional identity of the clone. These cDNA clones can now be used to study regulation of expression of the gene and to assess the role of inherited defects in this gene as a candidate for inherited susceptibility to non-insulin-dependent diabetes mellitus

  19. An 'alpha-beta' of pancreatic islet microribonucleotides

    DEFF Research Database (Denmark)

    Dalgaard, Louise Torp; Eliasson, Lena

    2017-01-01

    . Moreover, processing of miRNAs appears to be altered by obesity, diabetes, and aging. A number of miRNAs (such as miR-7, miR-21, miR-29, miR-34a, miR-212/miR-132, miR-184, miR-200 and miR-375) are involved in mediating beta cell dysfunction and/or compensation induced by hyperglycemia, oxidative stress......, cytotoxic cytokines, and in rodent models of fetal metabolic programming prediabetes and overt diabetes. Studies of human type 2 diabetic islets underline that these miRNA families could have important roles also in human type 2 diabetes. Furthermore, there is a genuine gap of knowledge regarding mi...

  20. Microcystic adenoma of the pancreas associated with non-functioning islet cell tumor: a case report

    International Nuclear Information System (INIS)

    Kong, Keun Young; Lee, Dong Ho; Ko, Young Tae; Kim, Youn Wha

    1997-01-01

    Among cystic tumors arising in the pancreas, microcystic adenoma is relatively uncommon;it is usually benign, and is comprised of cysts that vary in size from microscopic to 2 cm in diameter. It has recently been reported to be associated with other pancreatic tumors with malignant potential; in particular, microcystic adenoma with coexistent islet cell tumor has been reported in von Hippel-Lindau disease. We report a case of microcystic adenoma of the pancreas associated with coexistent surgically-proven islet cell tumor. On spiral CT, the islet cell tumor was seen as a highly enhanced inhomogeneous solid mass in the pancreatic head, and microcystic adenoma as numerous small cysts throughout the pancreas.=20

  1. Oxygenated thawing and rewarming alleviate rewarming injury of cryopreserved pancreatic islets.

    Science.gov (United States)

    Komatsu, Hirotake; Barriga, Alyssa; Medrano, Leonard; Omori, Keiko; Kandeel, Fouad; Mullen, Yoko

    2017-05-06

    Pancreatic islet transplantation is an effective treatment for Type 1 diabetic patients to eliminate insulin injections; however, a shortage of donor organs hinders the widespread use. Although long-term islet storage, such as cryopreservation, is considered one of the key solutions, transplantation of cryopreserved islets is still not practical due to the extensive loss during the cryopreservation-rewarming process. We have previously reported that culturing islets in a hyperoxic environment is an effective treatment to prevent islet death from the hypoxic injury during culture. In this study, we explored the effectiveness of thawing and rewarming cryopreserved islets in a hyperoxic environment. Following cryopreservation of isolated human islets, the thawing solution and culture media were prepared with or without pre-equilibration to 50% oxygen. Thawing/rewarming and the pursuant two-day culture were performed with or without oxygenation. Short-term recovery rate, defined as the volume change during cryopreservation and thawing/rewarming, was assessed. Ischemia-associated and inflammation-associated gene expressions were examined using qPCR after the initial rewarming period. Long-term recovery rate, defined as the volume change during the two-day culture after the thawing/rewarming, was also examined. Islet metabolism and function were assessed by basal oxygen consumption rate and glucose stimulated insulin secretion after long-term recovery. Oxygenated thawing/rewarming did not alter the short-term recovery rate. Inflammation-associated gene expressions were elevated by the conventional thawing/rewarming method and suppressed by the oxygenated thawing/rewarming, whereas ischemia-associated gene expressions did not change between the thawing/rewarming methods. Long-term recovery rate experiments revealed that only the combination therapy of oxygenated thawing/rewarming and oxygenated culture alleviated islet volume loss. These islets showed higher metabolism

  2. Transplanted human pancreatic islets after long-term insulin independence

    DEFF Research Database (Denmark)

    Muller, Y D; Gupta, Shashank; Morel, P

    2013-01-01

    Long-term insulin independence after islets of Langerhans transplantation is rarely achieved. The aims of this study were to identify the histological and immunological features of islets transplanted in a type 1 diabetic patient who died of a cerebral hemorrhage after >13 years insulin independe...

  3. Tailored imaging of islet cell tumors of the pancreas amidst increasing options

    NARCIS (Netherlands)

    Fiebrich, Helle-Brit; van Asselt, Sophie J.; Brouwers, Adrienne H.; van Dullemen, Hendrik M.; Pijl, Milan E. J.; Elsinga, Philip H.; Links, Thera P.; de Vries, Elisabeth G. E.

    Pancreatic islet cell tumors are neuroendocrine tumors, which can produce hormones and can arise as part of multiple endocrine neoplasia type 1 or von-Hippel-Lindau-disease, two genetically well-defined hereditary cancer syndromes. Currently, technical innovation improves conventional and specific

  4. Production of pancreatic hormone-expressing endocrine cells from human embryonic stem cells.

    Science.gov (United States)

    D'Amour, Kevin A; Bang, Anne G; Eliazer, Susan; Kelly, Olivia G; Agulnick, Alan D; Smart, Nora G; Moorman, Mark A; Kroon, Evert; Carpenter, Melissa K; Baetge, Emmanuel E

    2006-11-01

    Of paramount importance for the development of cell therapies to treat diabetes is the production of sufficient numbers of pancreatic endocrine cells that function similarly to primary islets. We have developed a differentiation process that converts human embryonic stem (hES) cells to endocrine cells capable of synthesizing the pancreatic hormones insulin, glucagon, somatostatin, pancreatic polypeptide and ghrelin. This process mimics in vivo pancreatic organogenesis by directing cells through stages resembling definitive endoderm, gut-tube endoderm, pancreatic endoderm and endocrine precursor--en route to cells that express endocrine hormones. The hES cell-derived insulin-expressing cells have an insulin content approaching that of adult islets. Similar to fetal beta-cells, they release C-peptide in response to multiple secretory stimuli, but only minimally to glucose. Production of these hES cell-derived endocrine cells may represent a critical step in the development of a renewable source of cells for diabetes cell therapy.

  5. Metabolic Profile of Pancreatic Acinar and Islet Tissue in Culture

    Science.gov (United States)

    Suszynski, Thomas M.; Mueller, Kathryn; Gruessner, Angelika C.; Papas, Klearchos K.

    2016-01-01

    The amount and condition of exocrine impurities may affect the quality of islet preparations especially during culture. In this study, the objective was to determine the oxygen demandand viability of islet and acinar tissue post-isolation and whether they change disproportionately while in culture. We compare the OCR normalized to DNA (OCR/DNA, a measure of fractional viability in units nmol/min/mg DNA), and percent change in OCR and DNA recoveries between adult porcine islet and acinar tissue from the same preparation (paired) over a 6-9 days of standard culture. Paired comparisons were done to quantify differences in OCR/DNA between islet and acinar tissue from the same preparation, at specified time points during culture; the mean (± standard error) OCR/DNA was 74.0 (±11.7) units higher for acinar (vs. islet) tissue on the day of isolation (n=16, p<0.0001), but 25.7 (±9.4) units lower after 1 day (n=8, p=0.03), 56.6 (±11.5) units lower after 2 days (n=12, p=0.0004), and 65.9 (±28.7) units lower after 8 days (n=4, p=0.2) in culture. DNA and OCR recoveries decreased at different rates for acinar versus islet tissue over 6-9 days in culture (n=6). DNA recovery decreased to 24±7% for acinar and 75±8% for islets (p=0.002). Similarly, OCR recovery decreased to 16±3% for acinar and remained virtually constant for islets (p=0.005). Differences in the metabolic profile of acinarand islet tissue should be considered when culturing impure islet preparations. OCR-based measurements may help optimize pre-IT culture protocols. PMID:25131082

  6. The fractal spatial distribution of pancreatic islets in three dimensions: a self-avoiding growth model

    International Nuclear Information System (INIS)

    Jo, Junghyo; Periwal, Vipul; Hörnblad, Andreas; Ahlgren, Ulf; Kilimnik, German; Hara, Manami

    2013-01-01

    The islets of Langerhans, responsible for controlling blood glucose levels, are dispersed within the pancreas. A universal power law governing the fractal spatial distribution of islets in two-dimensional pancreatic sections has been reported. However, the fractal geometry in the actual three-dimensional pancreas volume, and the developmental process that gives rise to such a self-similar structure, has not been investigated. Here, we examined the three-dimensional spatial distribution of islets in intact mouse pancreata using optical projection tomography and found a power law with a fractal dimension of 2.1. Furthermore, based on two-dimensional pancreatic sections of human autopsies, we found that the distribution of human islets also follows a universal power law with a fractal dimension of 1.5 in adult pancreata, which agrees with the value previously reported in smaller mammalian pancreas sections. Finally, we developed a self-avoiding growth model for the development of the islet distribution and found that the fractal nature of the spatial islet distribution may be associated with the self-avoidance in the branching process of vascularization in the pancreas. (paper)

  7. Microencapsulation of Pancreatic Islets for Use in a Bioartificial Pancreas

    Science.gov (United States)

    Opara, Emmanuel C.; McQuilling, John P.; Farney, Alan C.

    2013-01-01

    Islet transplantation is the most exciting treatment option for individuals afflicted with Type 1 diabetes. However, the severe shortage of human pancreas and the need to use risky immunosuppressive drugs to prevent transplant rejection remain two major obstacles for the routine use of islet transplantation in diabetic patients. Successful development of a bioartificial pancreas using the approach of microencapsulation with perm-selective coating of islets with biopolymers for graft immunoisolation holds tremendous promise for diabetic patients because it has great potential to overcome these two barriers. In this chapter, we provide a detailed description of the microencapsulation process. PMID:23494435

  8. Ca2+ controls slow NAD(P)H oscillations in glucose-stimulated mouse pancreatic islets

    DEFF Research Database (Denmark)

    Luciani, Dan Seriano; Misler, S.; Polonsky, K.S.

    2006-01-01

    Exposure of pancreatic islets of Langerhans to physiological concentrations of glucose leads to secretion of insulin in an oscillatory pattern. The oscillations in insulin secretion are associated with oscillations in cytosolic Ca2+ concentration ([Ca2+](c)). Evidence suggests that the oscillatio...

  9. COMPARISON OF TOP AND BOTTOM LOADING OF A DEXTRAN GRADIENT FOR RAT PANCREATIC-ISLET PURIFICATION

    NARCIS (Netherlands)

    FRITSCHY, WM; VANSUYLICHEM, PTR; WOLTERS, GHJ; VANSCHILFGAARDE, R

    Rat pancreatic islet yields obtained with dextran gradient purification were compared after suspending the digest into either the top or the bottom layer of the gradient. A 5-layer discontinuous gradient was used, which consisted of 16 ml 31% dextran as bottom layer, overlayered with 25%, 23%, 20%

  10. Effect of total lymphoid irradiation on pancreatic islet xenograft survival in rats

    International Nuclear Information System (INIS)

    Nakajima, Y.; Lie, T.S.; Nakauo, H.; Nakagawa, K.; Segawa, M.

    1984-01-01

    Before transplantation of Syrian hamster pancreatic islet xenografts to diabetic rats the recipients received total lymphatic system irradiation and cyclosporin A treatment after transplantation for immunosuppression. The xenograft survival times were measured and the rat anti-hamster lymphocytotoxic titers were determined by 51 Cr release assay

  11. Effect of total lymphoid irradiation on pancreatic islet xenograft survival in rats

    Energy Technology Data Exchange (ETDEWEB)

    Nakajima, Y; Lie, T S [Bonn Univ. (Germany, F.R.). Chirurgische Klinik und Poliklinik; Nakauo, H; Nakagawa, K; Segawa, M [Nara Women' s Univ. (Japan). Dept. of Physics

    1984-01-01

    Before transplantation of Syrian hamster pancreatic islet xenografts to diabetic rats the recipients received total lymphatic system irradiation and cyclosporin A treatment after transplantation for immunosuppression. The xenograft survival times were measured and the rat anti-hamster lymphocytotoxic titers were determined by /sup 51/Cr release assay.

  12. Uptake in the pancreatic islets of nicotimamide, nicotinic acid and tryptophan and their ability to prevent streptozotocin diabetes in mice

    Energy Technology Data Exchange (ETDEWEB)

    Tjaelve, H; Wilander, E [Uppsala Univ. (Sweden)

    1976-01-01

    The uptake of the nicotinamide adenine dinucleotide (NAD)-precursors nicotinamide, nicotinic acid and tryptophan in the pancreatic islets of mice was studied by use of autoradio-graphical methods. The ability of these substances to prevent streptozotocin diabetes was studied in the same species. It was found that only nicotinamide was strongly accumulated in the pancreatic islets and nicotinamide was also the only NAD-precursor which protected against the streptozotocin diabetes. Apparently there is a relationship between the ability of the NAD-precursors to be taken up in the pancreatic islets and their ability to prevent streptozotocin diabetes.

  13. The journey of islet cell transplantation and future development.

    Science.gov (United States)

    Gamble, Anissa; Pepper, Andrew R; Bruni, Antonio; Shapiro, A M James

    2018-03-04

    Intraportal islet transplantation has proven to be efficacious in preventing severe hypoglycemia and restoring insulin independence in selected patients with type 1 diabetes. Multiple islet infusions are often required to achieve and maintain insulin independence. Many challenges remain in clinical islet transplantation, including substantial islet cell loss early and late after islet infusion. Contributions to graft loss include the instant blood-mediated inflammatory reaction, potent host auto- and alloimmune responses, and beta cell toxicity from immunosuppressive agents. Protective strategies are being tested to circumvent several of these events including exploration of alternative transplantation sites, stem cell-derived insulin producing cell therapies, co-transplantation with mesenchymal stem cells or exploration of novel immune protective agents. Herein, we provide a brief introduction and history of islet cell transplantation, limitations associated with this procedure and methods to alleviate islet cell loss as a means to improve engraftment outcomes.

  14. A post-translational balancing act: the good and the bad of SUMOylation in pancreatic islets.

    Science.gov (United States)

    MacDonald, Patrick E

    2018-04-01

    Post-translational modification of proteins contributes to the control of cell function and survival. The balance of these in insulin-producing pancreatic beta cells is important for the maintenance of glucose homeostasis. Protection from the damaging effects of reactive oxygen species is required for beta cell survival, but if this happens at the expense of insulin secretory function then the ability of islets to respond to changing metabolic conditions may be compromised. In this issue of Diabetologia, He et al ( https://doi.org/10.1007/s00125-017-4523-9 ) show that post-translational attachment of small ubiquitin-like modifier (SUMO) to target lysine residues (SUMOylation) strikes an important balance between the protection of beta cells from oxidative stress and the maintenance of insulin secretory function. They show that SUMOylation is required to stabilise nuclear factor erythroid 2-related factor 2 (NRF2) and increase antioxidant gene expression. Decreasing SUMOylation in beta cells impairs their antioxidant capacity, causes cell death, hyperglycaemia, and increased sensitivity to streptozotocin-induced diabetes, while increasing SUMOylation is protective. However, this protection from overt diabetes occurs in concert with glucose intolerance due to impaired beta cell function. A possible role for SUMOylation as a key factor balancing beta cell protection vs beta cell responsiveness to metabolic cues is discussed in this Commentary.

  15. Automated Analysis of Microscopic Images of Isolated Pancreatic Islets

    Czech Academy of Sciences Publication Activity Database

    Habart, D.; Švihlík, J.; Schier, Jan; Cahová, M.; Girman, P.; Zacharovová, K.; Berková, Z.; Kříž, J.; Fabryová, E.; Kosinová, L.; Papáčková, Z.; Kybic, J.; Saudek, F.

    2016-01-01

    Roč. 25, č. 12 (2016), s. 2145-2156 ISSN 0963-6897 Grant - others:GA ČR(CZ) GA14-10440S Institutional support: RVO:67985556 Keywords : enumeration of islets * image processing * image segmentation * islet transplantation * machine-learning * quality control Subject RIV: IN - Informatics, Computer Science Impact factor: 3.006, year: 2016 http://library.utia.cas.cz/separaty/2016/ZOI/schier-0465945.pdf

  16. Human Monoclonal Islet Cell Antibodies From a Patient with Insulin- Dependent Diabetes Mellitus Reveal Glutamate Decarboxylase as the Target Antigen

    Science.gov (United States)

    Richter, Wiltrud; Endl, Josef; Eiermann, Thomas H.; Brandt, Michael; Kientsch-Engel, Rosemarie; Thivolet, Charles; Jungfer, Herbert; Scherbaum, Werner A.

    1992-09-01

    The autoimmune phenomena associated with destruction of the β cell in pancreatic islets and development of type 1 (insulin-dependent) diabetes mellitus (IDDM) include circulating islet cell antibodies. We have immortalized peripheral blood lymphocytes from prediabetic individuals and patients with newly diagnosed IDDM by Epstein-Barr virus transformation. IgG-positive cells were selected by anti-human IgG-coupled magnetic beads and expanded in cell culture. Supernatants were screened for cytoplasmic islet cell antibodies using the conventional indirect immunofluorescence test on cryostat sections of human pancreas. Six islet cell-specific B-cell lines, originating from a patient with newly diagnosed IDDM, could be stabilized on a monoclonal level. All six monoclonal islet cell antibodies (MICA 1-6) were of the IgG class. None of the MICA reacted with human thyroid, adrenal gland, anterior pituitary, liver, lung, stomach, and intestine tissues but all six reacted with pancreatic islets of different mammalian species and, in addition, with neurons of rat cerebellar cortex. MICA 1-6 were shown to recognize four distinct antigenic epitopes in islets. Islet cell antibody-positive diabetic sera but not normal human sera blocked the binding of the monoclonal antibodies to their target epitopes. Immunoprecipitation of 35S-labeled human islet cell extracts revealed that a protein of identical size to the enzyme glutamate decarboxylase (EC 4.1.1.15) was a target of all MICA. Furthermore, antigen immunotrapped by the MICA from brain homogenates showed glutamate decarboxylase enzyme activity. MICA 1-6 therefore reveal glutamate decarboxylase as the predominant target antigen of cytoplasmic islet cell autoantibodies in a patient with newly diagnosed IDDM.

  17. Phosphatidylcholine (PC) biosynthesis in pancreatic islets of Langerhans

    International Nuclear Information System (INIS)

    Hoffman, J.M.; Laychock, S.G.

    1986-01-01

    Islets of Langerhans isolated from rat pancreata were incubated with [ 14 C]choline to determine the biosynthesis of PC by the CDP choline to determine the biosynthesis of PC by the CDPcholine pathway. Recovery of [ 14 C]PC in islet membranes was time-related, and stimulated by glucose (17mM) during 60 min. The rate of PC synthesis was constant during 60 min with glucose stimulation. In contrast, the sulfonylurea tolbutamide (2 mM) reduced the recovery of [ 14 C]choline in PC, and 8-bromo-cyclic AMP (5 mM) did not significantly affect [ 14 C]PC recovery. Incubation of islets in Ca 2+ -free medium enhanced glucose-stimulated recovery of [ 14 C]choline-labeled PC due to the inhibition of phospholipase and phospholipid hydrolysis. Inhibition of CTP:phosphocholine cytidylyltransferase with 5-deoxy-5'-isobutylthioadenosine (SIBA) reduced [ 14 C]PC levels and insulin release in a concentration dependent manner. Treatment with SIBA also reduced Mg 2+ -dependent Ca 2+ -ATPase activity in islet microsomes. Quantitation of membrane PC showed that glucose stimulation did not alter islet P levels. Thus, islet PC biosynthesis is linked to glucose stimulation and contributes to the maintenance of PC levels in membranes undergoing exocytosis and phospholipid hydrolysis. Adequate PC levels support Ca 2+ pump activity and secretory mechanisms

  18. Engineering of microscale three-dimensional pancreatic islet models in vitro and their biomedical applications.

    Science.gov (United States)

    Gao, Bin; Wang, Lin; Han, Shuang; Pingguan-Murphy, Belinda; Zhang, Xiaohui; Xu, Feng

    2016-08-01

    Diabetes now is the most common chronic disease in the world inducing heavy burden for the people's health. Based on this, diabetes research such as islet function has become a hot topic in medical institutes of the world. Today, in medical institutes, the conventional experiment platform in vitro is monolayer cell culture. However, with the development of micro- and nano-technologies, several microengineering methods have been developed to fabricate three-dimensional (3D) islet models in vitro which can better mimic the islet of pancreases in vivo. These in vitro islet models have shown better cell function than monolayer cells, indicating their great potential as better experimental platforms to elucidate islet behaviors under both physiological and pathological conditions, such as the molecular mechanisms of diabetes and clinical islet transplantation. In this review, we present the state-of-the-art advances in the microengineering methods for fabricating microscale islet models in vitro. We hope this will help researchers to better understand the progress in the engineering 3D islet models and their biomedical applications such as drug screening and islet transplantation.

  19. Human pancreatic islet transplantation: an update and description of the establishment of a pancreatic islet isolation laboratory.

    Science.gov (United States)

    Rheinheimer, Jakeline; Bauer, Andrea C; Silveiro, Sandra P; Estivalet, Aline A F; Bouças, Ana P; Rosa, Annelise R; Souza, Bianca M de; Oliveira, Fernanda S de; Cruz, Lavínia A; Brondani, Letícia A; Azevedo, Mirela J; Lemos, Natália E; Carlessi, Rodrigo; Assmann, Taís S; Gross, Jorge L; Leitão, Cristiane B; Crispim, Daisy

    2015-04-01

    Type 1 diabetes mellitus (T1DM) is associated with chronic complications that lead to high morbidity and mortality rates in young adults of productive age. Intensive insulin therapy has been able to reduce the likelihood of the development of chronic diabetes complications. However, this treatment is still associated with an increased incidence of hypoglycemia. In patients with "brittle T1DM", who have severe hypoglycemia without adrenergic symptoms (hypoglycemia unawareness), islet transplantation may be a therapeutic option to restore both insulin secretion and hypoglycemic perception. The Edmonton group demonstrated that most patients who received islet infusions from more than one donor and were treated with steroid-free immunosuppressive drugs displayed a considerable decline in the initial insulin independence rates at eight years following the transplantation, but showed permanent C-peptide secretion, which facilitated glycemic control and protected patients against hypoglycemic episodes. Recently, data published by the Collaborative Islet Transplant Registry (CITR) has revealed that approximately 50% of the patients who undergo islet transplantation are insulin independent after a 3-year follow-up. Therefore, islet transplantation is able to successfully decrease plasma glucose and HbA1c levels, the occurrence of severe hypoglycemia, and improve patient quality of life. The goal of this paper was to review the human islet isolation and transplantation processes, and to describe the establishment of a human islet isolation laboratory at the Endocrine Division of the Hospital de Clínicas de Porto Alegre - Rio Grande do Sul, Brazil.

  20. Exercise Increases Insulin Content and Basal Secretion in Pancreatic Islets in Type 1 Diabetic Mice

    Directory of Open Access Journals (Sweden)

    Han-Hung Huang

    2011-01-01

    Full Text Available Exercise appears to improve glycemic control for people with type 1 diabetes (T1D. However, the mechanism responsible for this improvement is unknown. We hypothesized that exercise has a direct effect on the insulin-producing islets. Eight-week-old mice were divided into four groups: sedentary diabetic, exercised diabetic, sedentary control, and exercised control. The exercised groups participated in voluntary wheel running for 6 weeks. When compared to the control groups, the islet density, islet diameter, and β-cell proportion per islet were significantly lower in both sedentary and exercised diabetic groups and these alterations were not improved with exercise. The total insulin content and insulin secretion were significantly lower in sedentary diabetics compared to controls. Exercise significantly improved insulin content and insulin secretion in islets in basal conditions. Thus, some improvements in exercise-induced glycemic control in T1D mice may be due to enhancement of insulin content and secretion in islets.

  1. Immunosuppression, macroencapsulation and ultraviolet-B irradiation as immunoprotection in porcine pancreatic islet xenotransplantation

    Energy Technology Data Exchange (ETDEWEB)

    Sandberg, J.O.; Olsson, N.; Hellerstroem, C.; Andersson, A. [Uppsala Univerity, Dept. of Medical Cell Biology, Uppsala (Sweden); Johnson, R.C. [Baxter Healthcar Corporation, Gene Therapy Unit, Illinois (United States)

    1995-09-01

    Membrane encapsulation or ultraviolet-B irradiation, with or without mild immunosuppressive treatment, was applied in order to prolong the survival of xenogeneic porcine foetal pancreatic grafts. Non-diabetic C57BL/6 mice were transplanted with porcine islet-like cell clusters, either membrane-encapsulated in the epididymal fat pad, or non-encapsulated under the kidney capsule. The animals were treated with daily subcutaneous injections of either cyclosporin A (12.5 mg/kg b.wt.), 15-deoxyspergualin (5.0 mg/kg b.wt.), ethyl (E)-6-(1,3-dihydro-4-hydroxy-6-methoxy-7-methyl-3-oxo-6-isobenzofurany l-4-methyl-4-hexenoate). (RS-61443) (70 mg/kg b.wt.) or with cyclophosphamide (70 mg/kg b.wt.) every second day. A fulminant mononuclear cell infiltration was observed 14 days after transplantation both around the subcapsular graft and outside the membranes in the saline treated control group. The membrane had pores of 0.45 {mu}m and was designed to allow macromolecule transport but prevents cells from crossing. Therefore, xenoantigens can escape from the membrane implants and cause an immune reaction. A significantly weaker mononuclear cell infiltration was, however, seen when the membrane barrier was combined with 15-deoxyspergualin, cyclophosphamide or RS-61443 treatment but the morphology of the encapsulated ICC was not improved. The best subcapsular, non-encapsulated graft survival was obtained in animals treated with 15-deoxyspergualin or cyclophosphamide and the graft insulin content measurements confirmed the morphological data. There was no prolongation of islet-like cell cluster graft survival under the kidney capsule after ultraviolet-B irradiation alone (650 J/m{sup 2} for 90 sec.), and no synergistic effect was observed. It is concluded that neither membrane encapsulation with membrane that allow xenoantigen escape from the implants nor ultraviolet-B irradiation are able to prolong discordant xenograft survival in mice. (Abstract Truncated)

  2. The Brain–to–Pancreatic Islet Neuronal Map Reveals Differential Glucose Regulation From Distinct Hypothalamic Regions

    Science.gov (United States)

    Rosario, Wilfredo; Singh, Inderroop; Wautlet, Arnaud; Patterson, Christa; Flak, Jonathan; Becker, Thomas C.; Ali, Almas; Tamarina, Natalia; Philipson, Louis H.; Enquist, Lynn W.; Myers, Martin G.

    2016-01-01

    The brain influences glucose homeostasis, partly by supplemental control over insulin and glucagon secretion. Without this central regulation, diabetes and its complications can ensue. Yet, the neuronal network linking to pancreatic islets has never been fully mapped. Here, we refine this map using pseudorabies virus (PRV) retrograde tracing, indicating that the pancreatic islets are innervated by efferent circuits that emanate from the hypothalamus. We found that the hypothalamic arcuate nucleus (ARC), ventromedial nucleus (VMN), and lateral hypothalamic area (LHA) significantly overlap PRV and the physiological glucose-sensing enzyme glucokinase. Then, experimentally lowering glucose sensing, specifically in the ARC, resulted in glucose intolerance due to deficient insulin secretion and no significant effect in the VMN, but in the LHA it resulted in a lowering of the glucose threshold that improved glucose tolerance and/or improved insulin sensitivity, with an exaggerated counter-regulatory response for glucagon secretion. No significant effect on insulin sensitivity or metabolic homeostasis was noted. Thus, these data reveal novel direct neuronal effects on pancreatic islets and also render a functional validation of the brain-to-islet neuronal map. They also demonstrate that distinct regions of the hypothalamus differentially control insulin and glucagon secretion, potentially in partnership to help maintain glucose homeostasis and guard against hypoglycemia. PMID:27207534

  3. The Brain-to-Pancreatic Islet Neuronal Map Reveals Differential Glucose Regulation From Distinct Hypothalamic Regions.

    Science.gov (United States)

    Rosario, Wilfredo; Singh, Inderroop; Wautlet, Arnaud; Patterson, Christa; Flak, Jonathan; Becker, Thomas C; Ali, Almas; Tamarina, Natalia; Philipson, Louis H; Enquist, Lynn W; Myers, Martin G; Rhodes, Christopher J

    2016-09-01

    The brain influences glucose homeostasis, partly by supplemental control over insulin and glucagon secretion. Without this central regulation, diabetes and its complications can ensue. Yet, the neuronal network linking to pancreatic islets has never been fully mapped. Here, we refine this map using pseudorabies virus (PRV) retrograde tracing, indicating that the pancreatic islets are innervated by efferent circuits that emanate from the hypothalamus. We found that the hypothalamic arcuate nucleus (ARC), ventromedial nucleus (VMN), and lateral hypothalamic area (LHA) significantly overlap PRV and the physiological glucose-sensing enzyme glucokinase. Then, experimentally lowering glucose sensing, specifically in the ARC, resulted in glucose intolerance due to deficient insulin secretion and no significant effect in the VMN, but in the LHA it resulted in a lowering of the glucose threshold that improved glucose tolerance and/or improved insulin sensitivity, with an exaggerated counter-regulatory response for glucagon secretion. No significant effect on insulin sensitivity or metabolic homeostasis was noted. Thus, these data reveal novel direct neuronal effects on pancreatic islets and also render a functional validation of the brain-to-islet neuronal map. They also demonstrate that distinct regions of the hypothalamus differentially control insulin and glucagon secretion, potentially in partnership to help maintain glucose homeostasis and guard against hypoglycemia. © 2016 by the American Diabetes Association.

  4. Factors Influencing Quantification of in Vivo Bioluminescence Imaging: Application to Assessment of Pancreatic Islet Transplants

    Directory of Open Access Journals (Sweden)

    John Virostko

    2004-10-01

    Full Text Available The aim of this study is to determine and characterize factors influencing in vivo bioluminescence imaging (BLI and apply them to the specific application of imaging transplanted pancreatic islets. Noninvasive quantitative assessment of transplanted pancreatic islets poses a formidable challenge. Murine pancreatic islets expressing firefly luciferase were transplanted under the renal capsule or into the portal vein of nonobese diabetic–severe combined immunodeficiency mice and the bioluminescence was quantified with a cooled charge coupled device camera and digital photon image analysis. The important, but often neglected, effects of wound healing, mouse positioning, and transplantation site on bioluminescence measurements were investigated by imaging a constant emission, isotropic light-emitting bead (λ = 600 implanted at the renal or hepatic site. The renal beads emitted nearly four times more light than hepatic beads with a smaller spot size, indicating that light absorption and scatter are greatly influenced by the transplant site and must be accounted for in BLI measurements. Detected luminescence decreased with increasing angle between the mouse surface normal and optical axis. By defining imaging parameters such as postsurgical effects, animal positioning, and light attenuation as a function of transplant site, this study develops BLI as a useful imaging modality for quantitative assessment of islets post-transplantation.

  5. Advances in pancreatic islet transplantation for the treatment of diabetes%胰岛移植治疗糖尿病的现状和进展

    Institute of Scientific and Technical Information of China (English)

    彭丹凤; 贾伟平

    2012-01-01

    胰岛移植是治疗糖尿病尤其是1型糖尿病的一种简单有效的方法,相较与胰腺移植,它较为简单和方便,但存在组织来源匮乏和免疫移植排斥等障碍.新的胰岛分离纯化方法提高了供移植的胰岛的纯度和活性.成体干细胞研究、异种移植研究,有望解决移植的供源问题.Edmonton方案在胰岛移植的临床应用中具有里程碑意义.新型的免疫抑制剂和免疫诱导剂的研究可以提高临床胰岛移植的成功率.%Objective Pancreatic islet transplantation is effective in treating diabetes, especially in type 1 diabetes. It can provide diabetes management with good glycemic control and insulin independence. Compared to pancreas transplantation, islet transplantation is technically much simplier and safer. However, currently its clinical use is highly restricted by a series of influence factors, including lack of sufficient donor organs and the side effects of immunosuppressive therapy. With recent advances in methods of islet isolation and purification, we can get better donor organs. Deriving islet cells from other sources such as pigs, human pancreatic duct cells, fetal pancreatic stem cells, and embryonic stem cells will overcome shortage of donor organs. The use of the Edmonton protocol has been proved to be the key procedure of clinical islet transplantation. And study of new immunosuppressive drugs and immunomodulators can provide higher rate of success for clinical islet transplantation.

  6. JANEX-1, a JAK3 inhibitor, protects pancreatic islets from cytokine toxicity through downregulation of NF-{kappa}B activation and the JAK/STAT pathway

    Energy Technology Data Exchange (ETDEWEB)

    Lv, Na; Kim, Eun-Kyung; Song, Mi-Young [Department of Biochemistry, Medical School and Diabetes Research Center, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of); Choi, Ha-Na; Moon, Woo Sung [Department of Pathology, Medical School and Diabetes Research Center, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of); Park, Sung-Joo [Department of Herbology, School of Oriental Medicine, Wonkwang University, Iksan, Jeonbuk 570-749 (Korea, Republic of); Park, Jin-Woo [Department of Biochemistry, Medical School and Diabetes Research Center, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of); Kwon, Kang-Beom, E-mail: desson@wonkwang.ac.kr [Department of Physiology, School of Oriental Medicine, Wonkwang University, Iksan, Jeonbuk 570-749 (Korea, Republic of); Park, Byung-Hyun, E-mail: bhpark@chonbuk.ac.kr [Department of Biochemistry, Medical School and Diabetes Research Center, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of)

    2009-07-15

    JANEX-1/WHI-P131, a selective Janus kinase 3 (JAK3) inhibitor, has been shown to delay the onset of diabetes in the NOD mouse model. However, the molecular mechanism by which JANEX-1 protects pancreatic {beta}-cells is unknown. In the current study, we investigated the role of JANEX-1 on interleukin (IL)-1{beta} and interferon (IFN)-{gamma}-induced {beta}-cell damage using isolated islets. JANEX-1-pretreated islets showed resistance to cytokine toxicity, namely suppressed nitric oxide (NO) production, reduced inducible form of NO synthase (iNOS) expression, and decreased islet destruction. The molecular mechanism by which JANEX-1 inhibits iNOS expression was mediated through suppression of the nuclear factor {kappa}B (NF-{kappa}B) and JAK/signal transducer and activator of transcription (STAT) pathways. Islets treated with the cytokines downregulated the protein levels of suppressor of cytokine signaling (SOCS)-1 and SOCS-3, but pretreatment with JANEX-1 attenuated these decreases. Additionally, islets from JAK3{sup -/-} mice were more resistant to cytokine toxicity than islets from control mice. These results demonstrate that JANEX-1 protects {beta}-cells from cytokine toxicity through suppression of the NF-{kappa}B and JAK/STAT pathways and upregulation of SOCS proteins, suggesting that JANEX-1 may be used to preserve functional {beta}-cell mass.

  7. Endothelial chimerism and vascular sequestration protect pancreatic islet grafts from antibody-mediated rejection

    Science.gov (United States)

    Chen, Chien-Chia; Pouliquen, Eric; Broisat, Alexis; Andreata, Francesco; Racapé, Maud; Bruneval, Patrick; Kessler, Laurence; Ahmadi, Mitra; Bacot, Sandrine; Saison-Delaplace, Carole; Marcaud, Marina; Van Huyen, Jean-Paul Duong; Loupy, Alexandre; Villard, Jean; Demuylder-Mischler, Sandrine; Morelon, Emmanuel; Tsai, Meng-Kun; Kolopp-Sarda, Marie-Nathalie; Koenig, Alice; Mathias, Virginie; Ghezzi, Catherine; Dubois, Valerie; Defrance, Thierry

    2017-01-01

    Humoral rejection is the most common cause of solid organ transplant failure. Here, we evaluated a cohort of 49 patients who were successfully grafted with allogenic islets and determined that the appearance of donor-specific anti-HLA antibodies (DSAs) did not accelerate the rate of islet graft attrition, suggesting resistance to humoral rejection. Murine DSAs bound to allogeneic targets expressed by islet cells and induced their destruction in vitro; however, passive transfer of the same DSAs did not affect islet graft survival in murine models. Live imaging revealed that DSAs were sequestrated in the circulation of the recipients and failed to reach the endocrine cells of grafted islets. We used murine heart transplantation models to confirm that endothelial cells were the only accessible targets for DSAs, which induced the development of typical microvascular lesions in allogeneic transplants. In contrast, the vasculature of DSA-exposed allogeneic islet grafts was devoid of lesions because sprouting of recipient capillaries reestablished blood flow in grafted islets. Thus, we conclude that endothelial chimerism combined with vascular sequestration of DSAs protects islet grafts from humoral rejection. The reduced immunoglobulin concentrations in the interstitial tissue, confirmed in patients, may have important implications for biotherapies such as vaccines and monoclonal antibodies. PMID:29202467

  8. 3-D Imaging Reveals Participation of Donor Islet Schwann Cells and Pericytes in Islet Transplantation and Graft Neurovascular Regeneration

    OpenAIRE

    Juang, Jyuhn-Huarng; Kuo, Chien-Hung; Peng, Shih-Jung; Tang, Shiue-Cheng

    2015-01-01

    The primary cells that participate in islet transplantation are the endocrine cells. However, in the islet microenvironment, the endocrine cells are closely associated with the neurovascular tissues consisting of the Schwann cells and pericytes, which form sheaths/barriers at the islet exterior and interior borders. The two cell types have shown their plasticity in islet injury, but their roles in transplantation remain unclear. In this research, we applied 3-dimensional neurovascular histolo...

  9. Pancreatectomy and autologous islet transplantation for painful chronic pancreatitis: indications and outcomes.

    Science.gov (United States)

    Bellin, Melena D; Sutherland, David E R; Robertson, R Paul

    2012-08-01

    Total pancreatectomy with intrahepatic autoislet transplantation (TP/IAT) is a definitive treatment for relentlessly painful chronic pancreatitis. Pain relief is reported to be achieved in approximately 80% of patients. Overall, 30% to 40% achieve insulin independence, and 70% of recipients remain insulin independent for > 2 years, sometimes longer if > 300 000 islets are successfully transplanted. Yet, this approach to chronic pancreatitis is underemphasized in the general medical and surgical literature and vastly underused in the United States. This review emphasizes the history and metabolic outcomes of TP/IAT and considers its usefulness in the context of other, more frequently used approaches, such as operative intervention with partial pancreatectomy and/or lateral pancreaticojejunostomy (Puestow procedure), as well as endoscopic retrograde cholangiopancreatography with pancreatic duct modification and stent placement. Distal pancreatectomy and Puestow procedures compromise isolation of islet mass, and adversely affect islet autotransplant outcomes. Therefore, when endoscopic measures fail to relieve pain in severe chronic pancreatitis, we recommend early intervention with TP/IAT.

  10. Effect of liver histopathology on islet cell engraftment in the model mimicking autologous islet cell transplantation.

    Science.gov (United States)

    Desai, Chirag S; Khan, Khalid M; Ma, Xiaobo; Li, Henghong; Wang, Juan; Fan, Lijuan; Chen, Guoling; Smith, Jill P; Cui, Wanxing

    2017-11-02

    The inflammatory milieu in the liver as determined by histopathology is different in individual patients undergoing autologous islet cell transplantation. We hypothesized that inflammation related to fatty-liver adversely impacts islet survival. To test this hypothesis, we used a mouse model of fatty-liver to determine the outcome of syngeneic islet transplantation after chemical pancreatectomy. Mice (C57BL/6) were fed a high-fat-diet from 6 weeks of age until attaining a weight of ≥28 grams (6-8 weeks) to produce a fatty liver (histologically > 30% fat);steatosis was confirmed with lipidomic profile of liver tissue. Islets were infused via the intra-portal route in fatty-liver and control mice after streptozotocin induction of diabetes. Outcomes were assessed by the rate of euglycemia, liver histopathology, evaluation of liver inflammation by measuring tissue cytokines IL-1β and TNF-α by RT-PCR and CD31 expression by immunohistochemistry. The difference in the euglycemic fraction between the normal liver group (90%, 9/10) and the fatty-liver group (37.5%, 3/8) was statistically significant at the 18 th day post- transplant and was maintained to the end of the study (day 28) (p = 0.019, X 2 = 5.51). Levels of TNF-α and IL-1β were elevated in fatty-liver mice (p = 0.042, p = 0.037). Compared to controls cytokine levels were elevated after islet cell transplantation and in transplanted fatty-liver mice as compared to either fatty- or islet transplant group alone (p = NS). A difference in the histochemical pattern of CD31 could not be determined. Fatty-liver creates an inflammatory state which adversely affects the outcome of autologous islet cell transplantation.

  11. Preparation of rat islet B-cell-enriched fractions by light-scatter flow cytometry

    International Nuclear Information System (INIS)

    Rabinovitch, A.; Russell, T.; Shienvold, F.; Noel, J.; Files, N.; Patel, Y.; Ingram, M.

    1982-01-01

    Flow cytometry has been examined as a method to separate islet cells into homogeneous subpopulations. Collagenase-isolated rat islets were dissociated into single cells and these were analyzed and sorted according to their low forward angle light scattering properties by using automated flow cytometry. Light scatter histograms showed two peaks of viable cells. Radioimmunoassay of hormone content in cell fractions collected across the the two peaks showed that glucagon-containing cells were concentrated towards the left side of the left peak and somatostatin-containing cells were concentrated towards the right side of the left peak, whereas insulin-containing cells were clearly enriched in the right peak. The B-cell-enriched fraction (90% B cells, 3% A cells, 2% D cells) exhibited significant insulin secretory responses to glucose (16.7 mM), and 3-isobutyl-1-methylxanthine (0.1 mM), during a 24-h culture period, and these responses were slightly greater than those observed in the original mixed islet cell preparation (66% B cells, 14% A cells, and 4% D cells). These results indicate that flow cytometry can be applied to sort pancreatic islet cells into populations enriched in specific endocrine cell types for further study of the functions of individual cell types

  12. What is the origin of pancreatic adenocarcinoma?

    Directory of Open Access Journals (Sweden)

    Pandey Krishan K

    2003-01-01

    Full Text Available Abstract The concept of pancreatic cancer origin is controversial. Acinar, ductal or islet cells have been hypothesized as the cell of origin. The pros and cons of each of these hypotheses are discussed. Based on the world literature and recent observations, pancreatic cells seem to have potential for phenotypical transdifferentiation, i.e ductal-islet, ductal-acinar, acinar-ductal, acinar-islet, islet-acinar and islet-ductal cells. Although the possibility is discussed that cancer may arise from either islet, ductal or acinar cells, the circumstances favoring the islet cells as the tumor cell origin include their greater transdifferentiation potency into both pancreatic and extrapancreatic cells, the presence of a variety of carcinogen-metabolizing enzymes, some of which are present exclusively in islet cells and the growth factor-rich environment of islets.

  13. Inflammatory Response in Islet Transplantation

    Directory of Open Access Journals (Sweden)

    Mazhar A. Kanak

    2014-01-01

    Full Text Available Islet cell transplantation is a promising beta cell replacement therapy for patients with brittle type 1 diabetes as well as refractory chronic pancreatitis. Despite the vast advancements made in this field, challenges still remain in achieving high frequency and long-term successful transplant outcomes. Here we review recent advances in understanding the role of inflammation in islet transplantation and development of strategies to prevent damage to islets from inflammation. The inflammatory response associated with islets has been recognized as the primary cause of early damage to islets and graft loss after transplantation. Details on cell signaling pathways in islets triggered by cytokines and harmful inflammatory events during pancreas procurement, pancreas preservation, islet isolation, and islet infusion are presented. Robust control of pre- and peritransplant islet inflammation could improve posttransplant islet survival and in turn enhance the benefits of islet cell transplantation for patients who are insulin dependent. We discuss several potent anti-inflammatory strategies that show promise for improving islet engraftment. Further understanding of molecular mechanisms involved in the inflammatory response will provide the basis for developing potent therapeutic strategies for enhancing the quality and success of islet transplantation.

  14. Inflammatory Response in Islet Transplantation

    Science.gov (United States)

    Kanak, Mazhar A.; Kunnathodi, Faisal; Lawrence, Michael C.; Levy, Marlon F.

    2014-01-01

    Islet cell transplantation is a promising beta cell replacement therapy for patients with brittle type 1 diabetes as well as refractory chronic pancreatitis. Despite the vast advancements made in this field, challenges still remain in achieving high frequency and long-term successful transplant outcomes. Here we review recent advances in understanding the role of inflammation in islet transplantation and development of strategies to prevent damage to islets from inflammation. The inflammatory response associated with islets has been recognized as the primary cause of early damage to islets and graft loss after transplantation. Details on cell signaling pathways in islets triggered by cytokines and harmful inflammatory events during pancreas procurement, pancreas preservation, islet isolation, and islet infusion are presented. Robust control of pre- and peritransplant islet inflammation could improve posttransplant islet survival and in turn enhance the benefits of islet cell transplantation for patients who are insulin dependent. We discuss several potent anti-inflammatory strategies that show promise for improving islet engraftment. Further understanding of molecular mechanisms involved in the inflammatory response will provide the basis for developing potent therapeutic strategies for enhancing the quality and success of islet transplantation. PMID:24883060

  15. Robot-assisted pancreatoduodenectomy with preservation of the vascular supply for autologous islet cell isolation and transplantation: a case report

    Directory of Open Access Journals (Sweden)

    Giulianotti Piero

    2012-03-01

    Full Text Available Abstract Introduction For patients with chronic pancreatitis presenting with medically intractable abdominal pain, surgical intervention may be the only treatment option. However, extensive pancreatic resections are typically performed open and are associated with a substantial amount of postoperative pain, wound complications and long recovery time. Minimally invasive surgery offers an avenue to improve results; however, current limitations of laparoscopic surgery render its application in the setting of chronic pancreatitis technically demanding. Additionally, pancreatic resections are associated with a high incidence of diabetes. Transplantation of islets isolated from the resected pancreas portion offers a way to prevent post-surgical diabetes; however, preservation of the vascular supply during pancreatic resection, which determines islet cell viability, is technically difficult using current laparoscopic approaches. With recent advances in the surgical field, robotic surgery now provides a means to overcome these obstacles to achieve the end goals of pain relief and preserved endocrine function. We present the first report of a novel, minimally invasive robotic approach for resection of the pancreatic head that preserves vascular supply and enables the isolation of a high yield of viable islets for transplantation. Case presentation A 35-year old Caucasian woman presented with intractable chronic abdominal pain secondary to chronic pancreatitis, with a stricture of her main pancreatic duct at the level of the ampulla of Vater and distal dilatation. She was offered a robotic-assisted pylorus-preserving pancreatoduodenectomy and subsequent islet transplantation, to both provide pain relief and preserve insulin-secretory reserves. Conclusion We present a novel, minimally invasive robotic approach for resection of the pancreatic head with complete preservation of the vascular supply, minimal warm ischemia time (less than three minutes and

  16. The hyperbolic effect of density and strength of inter beta-cell coupling on islet bursting: a theoretical investigation

    Directory of Open Access Journals (Sweden)

    Wang Xujing

    2008-08-01

    Full Text Available Abstract Background Insulin, the principal regulating hormone of blood glucose, is released through the bursting of the pancreatic islets. Increasing evidence indicates the importance of islet morphostructure in its function, and the need of a quantitative investigation. Recently we have studied this problem from the perspective of islet bursting of insulin, utilizing a new 3D hexagonal closest packing (HCP model of islet structure that we have developed. Quantitative non-linear dependence of islet function on its structure was found. In this study, we further investigate two key structural measures: the number of neighboring cells that each β-cell is coupled to, nc, and the coupling strength, gc. Results β-cell clusters of different sizes with number of β-cells nβ ranging from 1–343, nc from 0–12, and gc from 0–1000 pS, were simulated. Three functional measures of islet bursting characteristics – fraction of bursting β-cells fb, synchronization index λ, and bursting period Tb, were quantified. The results revealed a hyperbolic dependence on the combined effect of nc and gc. From this we propose to define a dimensionless cluster coupling index or CCI, as a composite measure for islet morphostructural integrity. We show that the robustness of islet oscillatory bursting depends on CCI, with all three functional measures fb, λ and Tb increasing monotonically with CCI when it is small, and plateau around CCI = 1. Conclusion CCI is a good islet function predictor. It has the potential of linking islet structure and function, and providing insight to identify therapeutic targets for the preservation and restoration of islet β-cell mass and function.

  17. 3-D Imaging Reveals Participation of Donor Islet Schwann Cells and Pericytes in Islet Transplantation and Graft Neurovascular Regeneration.

    Science.gov (United States)

    Juang, Jyuhn-Huarng; Kuo, Chien-Hung; Peng, Shih-Jung; Tang, Shiue-Cheng

    2015-02-01

    The primary cells that participate in islet transplantation are the endocrine cells. However, in the islet microenvironment, the endocrine cells are closely associated with the neurovascular tissues consisting of the Schwann cells and pericytes, which form sheaths/barriers at the islet exterior and interior borders. The two cell types have shown their plasticity in islet injury, but their roles in transplantation remain unclear. In this research, we applied 3-dimensional neurovascular histology with cell tracing to reveal the participation of Schwann cells and pericytes in mouse islet transplantation. Longitudinal studies of the grafts under the kidney capsule identify that the donor Schwann cells and pericytes re-associate with the engrafted islets at the peri-graft and perivascular domains, respectively, indicating their adaptability in transplantation. Based on the morphological proximity and cellular reactivity, we propose that the new islet microenvironment should include the peri-graft Schwann cell sheath and perivascular pericytes as an integral part of the new tissue.

  18. Factors influencing the properties and performance of microcapsules for immunoprotection of pancreatic islets.

    Science.gov (United States)

    van Schilfgaarde, R; de Vos, P

    1999-01-01

    There are several approaches of immunoprotection of pancreatic islets for the purpose of successful allo- or xenotransplantation in the absence of immunosuppressive medication. Extravascular approaches are either macroencapsulation (large numbers of islets together in one device) or microencapsulation. The latter approach is to envelop each individual islet in a semipermeable immunoprotective capsule. Quite promising results have been achieved with polylysine-alginate microencapsulated islet grafts in rodents, but clinical application is still restricted to a very small number of cases. Relevant considerations regard the following aspects. The biocompatibility of the microcapsules is influenced by the chemical composition of the materials applied and by mechanical factors related to the production process. With purified instead of crude alginates, the percentage of capsules with fibrotic overgrowth is reduced to approximately ten percent, and the remaining overgrowth is mainly explained by mechanical factors, i.e. inadequate encapsulation of individual islets. Even with purified alginates, however, the duration of encapsulated graft function is limited to a period of six to twenty weeks. Obviously, other factors than bioincompatibility play a role, which factors have to be identified. The limited duration of graft survival cannot be explained by rejection since, in rats, survival times of encapsulated isografts are similar, if not identical, to those of encapsulated allografts. An important factor is probably insufficient nutrition as a consequence of insufficient blood supply of the encapsulated and thus isolated islet. This also influences the functional performance of encapsulated islet grafts. Although normoglycemia can be readily obtained in streptozotocin diabetic rat recipients, glucose tolerance remains severely impaired, as a consequence of an insufficient increase of insulin levels in response to intravenous or oral glucose challenge. Important factors

  19. Incorporation of bone marrow cells in pancreatic pseudoislets improves posttransplant vascularization and endocrine function.

    Directory of Open Access Journals (Sweden)

    Christine Wittig

    Full Text Available Failure of revascularization is known to be the major reason for the poor outcome of pancreatic islet transplantation. In this study, we analyzed whether pseudoislets composed of islet cells and bone marrow cells can improve vascularization and function of islet transplants. Pancreatic islets isolated from Syrian golden hamsters were dispersed into single cells for the generation of pseudoislets containing 4×10(3 cells. To create bone marrow cell-enriched pseudoislets 2×10(3 islet cells were co-cultured with 2×10(3 bone marrow cells. Pseudoislets and bone marrow cell-enriched pseudoislets were transplanted syngeneically into skinfold chambers to study graft vascularization by intravital fluorescence microscopy. Native islet transplants served as controls. Bone marrow cell-enriched pseudoislets showed a significantly improved vascularization compared to native islets and pseudoislets. Moreover, bone marrow cell-enriched pseudoislets but not pseudoislets normalized blood glucose levels after transplantation of 1000 islet equivalents under the kidney capsule of streptozotocin-induced diabetic animals, although the bone marrow cell-enriched pseudoislets contained only 50% of islet cells compared to pseudoislets and native islets. Fluorescence microscopy of bone marrow cell-enriched pseudoislets composed of bone marrow cells from GFP-expressing mice showed a distinct fraction of cells expressing both GFP and insulin, indicating a differentiation of bone marrow-derived cells to an insulin-producing cell-type. Thus, enrichment of pseudoislets by bone marrow cells enhances vascularization after transplantation and increases the amount of insulin-producing tissue. Accordingly, bone marrow cell-enriched pseudoislets may represent a novel approach to increase the success rate of islet transplantation.

  20. Islet-like cell aggregates generated from human adipose tissue derived stem cells ameliorate experimental diabetes in mice.

    Directory of Open Access Journals (Sweden)

    Vikash Chandra

    Full Text Available BACKGROUND: Type 1 Diabetes Mellitus is caused by auto immune destruction of insulin producing beta cells in the pancreas. Currently available treatments include transplantation of isolated islets from donor pancreas to the patient. However, this method is limited by inadequate means of immuno-suppression to prevent islet rejection and importantly, limited supply of islets for transplantation. Autologous adult stem cells are now considered for cell replacement therapy in diabetes as it has the potential to generate neo-islets which are genetically part of the treated individual. Adopting methods of islet encapsulation in immuno-isolatory devices would eliminate the need for immuno-suppressants. METHODOLOGY/PRINCIPAL FINDINGS: In the present study we explore the potential of human adipose tissue derived adult stem cells (h-ASCs to differentiate into functional islet like cell aggregates (ICAs. Our stage specific differentiation protocol permit the conversion of mesodermic h-ASCs to definitive endoderm (Hnf3β, TCF2 and Sox17 and to PDX1, Ngn3, NeuroD, Pax4 positive pancreatic endoderm which further matures in vitro to secrete insulin. These ICAs are shown to produce human C-peptide in a glucose dependent manner exhibiting in-vitro functionality. Transplantation of mature ICAs, packed in immuno-isolatory biocompatible capsules to STZ induced diabetic mice restored near normoglycemia within 3-4 weeks. The detection of human C-peptide, 1155±165 pM in blood serum of experimental mice demonstrate the efficacy of our differentiation approach. CONCLUSIONS: h-ASC is an ideal population of personal stem cells for cell replacement therapy, given that they are abundant, easily available and autologous in origin. Our findings present evidence that h-ASCs could be induced to differentiate into physiologically competent functional islet like cell aggregates, which may provide as a source of alternative islets for cell replacement therapy in type 1 diabetes.

  1. Beta-Cell Replacement: Pancreas and Islet Cell Transplantation.

    Science.gov (United States)

    Niclauss, Nadja; Meier, Raphael; Bédat, Benoît; Berishvili, Ekaterine; Berney, Thierry

    2016-01-01

    Pancreas and islet transplantation are 2 types of beta-cell replacement therapies for type 1 diabetes mellitus. Since 1966, when pancreas transplantation was first performed, it has evolved to become a highly efficient procedure with high success rates, thanks to advances in surgical technique and immunosuppression. Pancreas transplantation is mostly performed as simultaneous pancreas-kidney transplantation in patients with end-stage nephropathy secondary to diabetes. In spite of its efficiency, pancreas transplantation is still a major surgical procedure burdened by high morbidity, which called for the development of less invasive and hazardous ways of replacing beta-cell function in the past. Islet transplantation was developed in the 1970s as a minimally invasive procedure with initially poor outcomes. However, since the report of the 'Edmonton protocol' in 2000, the functional results of islet transplantation have substantially and constantly improved and are about to match those of whole pancreas transplantation. Islet transplantation is primarily performed alone in nonuremic patients with severe hypoglycemia. Both pancreas transplantation and islet transplantation are able to abolish hypoglycemia and to prevent or slow down the development of secondary complications of diabetes. Pancreas transplantation and islet transplantation should be seen as two complementary, rather than competing, therapeutic approaches for beta-cell replacement that are able to optimize organ donor use and patient care. © 2016 S. Karger AG, Basel.

  2. Spontaneous Hypoglycemia After Islet Autotransplantation for Chronic Pancreatitis.

    Science.gov (United States)

    Lin, Yu Kuei; Faiman, Charles; Johnston, Philip C; Walsh, R Matthew; Stevens, Tyler; Bottino, Rita; Hatipoglu, Betul A

    2016-10-01

    Spontaneous hypoglycemia has been reported in patients after total pancreatectomy (TP) and islet autotransplantation (IAT) with maintained insulin independence. Details surrounding these events have not been well described. The objective of the study was to determine the frequency and characteristics of spontaneous hypoglycemia in patients undergoing TP-IAT and/or to ascertain predictive or protective factors of its development. This was an observational cohort study in 40 patients who underwent TP-IAT from August 2008 to May 2014, with a median follow-up of 34 months. The study was conducted at a single institution (Cleveland Clinic). Patients included recipients of TP-IAT. The intervention included small, frequent meals in those patients who developed spontaneous hypoglycemia. Incidence of spontaneous hypoglycemia development, characteristics of the patients developing hypoglycemia, and their response to small, frequent meals were measured. Six of 12 patients, who maintained insulin independence, developed spontaneous hypoglycemia. The episodes could be fasting, postprandial, and/or exercise associated, with the frequency ranging from two to three times daily to once every 1-2 weeks. All patients experienced at least one episode that required external assistance, glucagon administration, and/or emergent medical attention. Patients who developed hypoglycemia had a lower median age and tended to have a lower median islet equivalent/kg body weight but a higher median total islet equivalent, body mass index, and homeostatic model assessment for insulin resistance score. All patients who received small, frequent meal intervention had improvement in severity and/or frequency of the hypoglycemic episodes. Spontaneous hypoglycemia is prevalent after TP-IAT. Although the underlying pathophysiology responsible for these hypoglycemia events remains to be elucidated, small, frequent meal intervention is helpful in ameliorating this condition.

  3. Evolution of β-Cell Replacement Therapy in Diabetes Mellitus: Islet Cell Transplantation

    Science.gov (United States)

    Jahansouz, Cyrus; Jahansouz, Cameron; Kumer, Sean C.; Brayman, Kenneth L.

    2011-01-01

    Diabetes mellitus remains one of the leading causes of morbidity and mortality worldwide. According to the Centers for Disease Control and Prevention, approximately 23.6 million people in the United States are affected. Of these individuals, 5 to 10% have been diagnosed with Type 1 diabetes mellitus (T1DM), an autoimmune disease. Although it often appears in childhood, T1DM may manifest at any age, leading to significant morbidity and decreased quality of life. Since the 1960s, the surgical treatment for diabetes mellitus has evolved to become a viable alternative to insulin administration, beginning with pancreatic transplantation. While islet cell transplantation has emerged as another potential alternative, its role in the treatment of T1DM remains to be solidified as research continues to establish it as a truly viable alternative for achieving insulin independence. In this paper, the historical evolution, procurement, current status, benefits, risks, and ongoing research of islet cell transplantation are explored. PMID:22013505

  4. Immunosuppression, macroencapsulation and ultraviolet-B irradiation as immunoprotection in porcine pancreatic islet xenotransplantation

    International Nuclear Information System (INIS)

    Sandberg, J.O.; Olsson, N.; Hellerstroem, C.; Andersson, A.; Johnson, R.C.

    1995-01-01

    Membrane encapsulation or ultraviolet-B irradiation, with or without mild immunosuppressive treatment, was applied in order to prolong the survival of xenogeneic porcine foetal pancreatic grafts. Non-diabetic C57BL/6 mice were transplanted with porcine islet-like cell clusters, either membrane-encapsulated in the epididymal fat pad, or non-encapsulated under the kidney capsule. The animals were treated with daily subcutaneous injections of either cyclosporin A (12.5 mg/kg b.wt.), 15-deoxyspergualin (5.0 mg/kg b.wt.), ethyl (E)-6-(1,3-dihydro-4-hydroxy-6-methoxy-7-methyl-3-oxo-6-isobenzofurany l-4-methyl-4-hexenoate. (RS-61443) (70 mg/kg b.wt.) or with cyclophosphamide (70 mg/kg b.wt.) every second day. A fulminant mononuclear cell infiltration was observed 14 days after transplantation both around the subcapsular graft and outside the membranes in the saline treated control group. The membrane had pores of 0.45 μm and was designed to allow macromolecule transport but prevents cells from crossing. Therefore, xenoantigens can escape from the membrane implants and cause an immune reaction. A significantly weaker mononuclear cell infiltration was, however, seen when the membrane barrier was combined with 15-deoxyspergualin, cyclophosphamide or RS-61443 treatment but the morphology of the encapsulated ICC was not improved. The best subcapsular, non-encapsulated graft survival was obtained in animals treated with 15-deoxyspergualin or cyclophosphamide and the graft insulin content measurements confirmed the morphological data. There was no prolongation of islet-like cell cluster graft survival under the kidney capsule after ultraviolet-B irradiation alone (650 J/m 2 for 90 sec.), and no synergistic effect was observed when ultraviolet-B irradiation was combined with 15-deoxyspergualin therapy (2.0 mg/kg b.wt.). It is concluded that neither membrane encapsulation with membrane that allow xenoantigen escape from the implants nor ultraviolet-B irradiation are able to

  5. Demonstration of pepsinogen C in human pancreatic islets

    DEFF Research Database (Denmark)

    Poulsen, Steen Seier

    1987-01-01

    Pancreatic tissue from 16 post mortem kidney donors have been examined for the content of pepsinogens. A zymogen with electrophoretic mobility, isoelectric point and molecular weight equal to that of pepsinogen C of gastric origin was found in all specimens. A comparison between pepsinogen C extr...

  6. Laparoscopic Total Pancreatectomy With Islet Autotransplantation and Intraoperative Islet Separation as a Treatment for Patients With Chronic Pancreatitis.

    Science.gov (United States)

    Fan, Caleb J; Hirose, Kenzo; Walsh, Christi M; Quartuccio, Michael; Desai, Niraj M; Singh, Vikesh K; Kalyani, Rita R; Warren, Daniel S; Sun, Zhaoli; Hanna, Marie N; Makary, Martin A

    2017-06-01

    Pain management of patients with chronic pancreatitis (CP) can be challenging. Laparoscopy has been associated with markedly reduced postoperative pain but has not been widely applied to total pancreatectomy with islet autotransplantation (TPIAT). To examine the feasibility of using laparoscopic TPIAT (L-TPIAT) in the treatment of CP. Thirty-two patients with CP presented for TPIAT at a tertiary hospital from January 1, 2013, through December 31, 2015. Of the 22 patients who underwent L-TPIAT, 2 patients converted to an open procedure because of difficult anatomy and prior surgery. Pain and glycemic outcomes were recorded at follow-up visits every 3 to 6 months postoperatively. Operative outcomes included operative time, islet isolation time, warm ischemia time, islet equivalent (IE) counts, estimated blood loss, fluid resuscitation, and blood transfusions. Postoperative outcomes included length of stay, all-cause 30-day readmission rate, postoperative complications, mortality rate, subjective pain measurements, opioid use, random C-peptide levels, insulin requirements, and glycated hemoglobin level. Of the 32 patients who presented for TPIAT, 20 underwent L-TPIAT (8 men and 12 women; mean [SD] age, 39 [13] years; age range, 21-58 years). Indication for surgery was CP attributable to genetic mutation (n = 9), idiopathic pancreatitis (n = 6), idiopathic pancreatitis with pancreas divisum (n = 3), and alcohol abuse (n = 2). Mean (SD) operative time was 493 (78) minutes, islet isolation time was 185 (37) minutes, and warm ischemia time was 51 (62) minutes. The mean (SD) IE count was 1325 (1093) IE/kg. The mean (SD) length of stay was 11 (5) days, and the all-cause 30-day readmission rate was 35% (7 of 20 patients). None of the patients experienced postoperative surgical site infection, hernia, or small-bowel obstruction, and none died. Eighteen patients (90%) had a decrease or complete resolution of pain, and 12 patients (60%) no longer required opioid

  7. Construction of EMSC-islet co-localizing composites for xenogeneic porcine islet transplantation.

    Science.gov (United States)

    Kim, Jung-Sik; Chung, Hyunwoo; Byun, Nari; Kang, Seong-Jun; Lee, Sunho; Shin, Jun-Seop; Park, Chung-Gyu

    2018-03-04

    Pancreatic islet transplantation is an ultimate solution for treating patients with type 1 diabetes (T1D). The pig is an ideal donor of islets for replacing scarce human islets. Besides immunological hurdles, non-immunological hurdles including fragmentation and delayed engraftment of porcine islets need solutions to succeed in porcine islet xenotransplantation. In this study, we suggest a simple but effective modality, a cell/islet co-localizing composite, to overcome these challenges. Endothelial-like mesenchymal stem cells (EMSCs), differentiated from bone-marrow derived mouse mesenchymal stem cells (MSCs), and MSCs evenly coated the surface of porcine islets (>85%) through optimized culture conditions. Both MSCs and EMSCs significantly reduced the fragmentation of porcine islets and increased the islet masses, designated as islet equivalents (IEQs). In fibrin in vitro and in vivo angiogenesis analysis, constructed EMSC-islet composites showed higher angiogenic potentials than naked islets, MSC-islet composites, or human endothelial cell-islet composites. This novel delivery method of porcine islets may have beneficial effects on the engraftment of transplanted islets by prevention of fragmentation and enhancement of revascularization. Copyright © 2018 Elsevier Inc. All rights reserved.

  8. Interleukin-33-Activated Islet-Resident Innate Lymphoid Cells Promote Insulin Secretion through Myeloid Cell Retinoic Acid Production.

    Science.gov (United States)

    Dalmas, Elise; Lehmann, Frank M; Dror, Erez; Wueest, Stephan; Thienel, Constanze; Borsigova, Marcela; Stawiski, Marc; Traunecker, Emmanuel; Lucchini, Fabrizio C; Dapito, Dianne H; Kallert, Sandra M; Guigas, Bruno; Pattou, Francois; Kerr-Conte, Julie; Maechler, Pierre; Girard, Jean-Philippe; Konrad, Daniel; Wolfrum, Christian; Böni-Schnetzler, Marianne; Finke, Daniela; Donath, Marc Y

    2017-11-21

    Pancreatic-islet inflammation contributes to the failure of β cell insulin secretion during obesity and type 2 diabetes. However, little is known about the nature and function of resident immune cells in this context or in homeostasis. Here we show that interleukin (IL)-33 was produced by islet mesenchymal cells and enhanced by a diabetes milieu (glucose, IL-1β, and palmitate). IL-33 promoted β cell function through islet-resident group 2 innate lymphoid cells (ILC2s) that elicited retinoic acid (RA)-producing capacities in macrophages and dendritic cells via the secretion of IL-13 and colony-stimulating factor 2. In turn, local RA signaled to the β cells to increase insulin secretion. This IL-33-ILC2 axis was activated after acute β cell stress but was defective during chronic obesity. Accordingly, IL-33 injections rescued islet function in obese mice. Our findings provide evidence that an immunometabolic crosstalk between islet-derived IL-33, ILC2s, and myeloid cells fosters insulin secretion. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Amyloid Deposition in Transplanted Human Pancreatic Islets: A Conceivable Cause of Their Long-Term Failure

    Directory of Open Access Journals (Sweden)

    Arne Andersson

    2008-01-01

    Full Text Available Following the encouraging report of the Edmonton group, there was a rejuvenation of the islet transplantation field. After that, more pessimistic views spread when long-term results of the clinical outcome were published. A progressive loss of the β-cell function meant that almost all patients were back on insulin therapy after 5 years. More than 10 years ago, we demonstrated that amyloid deposits rapidly formed in human islets and in mouse islets transgenic for human IAPP when grafted into nude mice. It is, therefore, conceivable to consider amyloid formation as one potential candidate for the long-term failure. The present paper reviews attempts in our laboratories to elucidate the dynamics of and mechanisms behind the formation of amyloid in transplanted islets with special emphasis on the impact of long-term hyperglycemia.

  10. ER Stress and β-Cell Pathogenesis of Type 1 and Type 2 Diabetes and Islet Transplantation

    OpenAIRE

    Kataoka, Hitomi Usui; Noguchi, Hirofumi

    2013-01-01

    Endoplasmic reticulum (ER) stress affects the pathogenesis of diabetes. ER stress plays important roles, both in type 1 and type 2 diabetes, because pancreatic β-cells possess highly developed ER for insulin secretion. This review summarizes the relationship between ER stress and the pathogenesis of type 1 and type 2 diabetes. In addition, the association between islet transplantation and ER stress is discussed.

  11. Quality of life improves for pediatric patients after total pancreatectomy and islet autotransplant for chronic pancreatitis.

    Science.gov (United States)

    Bellin, Melena D; Freeman, Martin L; Schwarzenberg, Sarah Jane; Dunn, Ty B; Beilman, Gregory J; Vickers, Selwyn M; Chinnakotla, Srinath; Balamurugan, A N; Hering, Bernhard J; Radosevich, David M; Moran, Antoinette; Sutherland, David E R

    2011-09-01

    Total pancreatectomy (TP) and islet autotransplant (IAT) have been used to treat patients with painful chronic pancreatitis. Initial studies indicated that most patients experienced significant pain relief, but there were few validated measures of quality of life. We investigated whether health-related quality of life improved among pediatric patients undergoing TP/IAT. Nineteen consecutive children (aged 5-18 years) undergoing TP/IAT from December 2006 to December 2009 at the University of Minnesota completed the Medical Outcomes Study 36-item Short Form (SF-36) health questionnaire before and after surgery. Insulin requirements were recorded. Before TP/IAT, patients had below average health-related quality of life, based on data from the Medical Outcomes Study SF-36; they had a mean physical component summary (PCS) score of 30 and mental component summary (MCS) score of 34 (2 and 1.5 standard deviations, respectively, below the mean for the US population). By 1 year after surgery, PCS and MCS scores improved to 50 and 46, respectively (global effect, PCS P Puestow) had lower yields of islets (P = .01) and greater incidence of insulin dependence (P = .04). Quality of life (physical and emotional components) significantly improve after TP/IAT in subsets of pediatric patients with severe chronic pancreatitis. Minimal or no insulin was required for most patients, although islet yield was reduced in patients with previous surgical drainage operations. Copyright © 2011 AGA Institute. Published by Elsevier Inc. All rights reserved.

  12. Cytotoxicity of human pI 7 interleukin-1 for pancreatic islets of Langerhans

    DEFF Research Database (Denmark)

    Bendtzen, K; Mandrup-Poulsen, T; Nerup, J

    1986-01-01

    Activated mononuclear cells appear to be important effector cells in autoimmune beta cell destruction leading to insulin-dependent (type 1) diabetes mellitus. Conditioned medium from activated mononuclear cells (from human blood) is cytotoxic to isolated rat and human islets of Langerhans. This c...

  13. Growth hormone is a growth factor for the differentiated pancreatic beta-cell

    DEFF Research Database (Denmark)

    Linde, S; Welinder, B S; Billestrup, N

    1989-01-01

    The regulation of the growth of the pancreatic beta-cell is poorly understood. There are previous indications of a role of GH in the growth and insulin production of the pancreatic islets. In the present study we present evidence for a direct long-term effect of GH on proliferation and insulin...

  14. Sustained NF-κB activation and inhibition in β-cells have minimal effects on function and islet transplant outcomes.

    Directory of Open Access Journals (Sweden)

    Aileen J F King

    Full Text Available The activation of the transcription factor NF-κB leads to changes in expression of many genes in pancreatic β-cells. However, the role of NF-κB activation in islet transplantation has not been fully elucidated. The aim of the present study was to investigate whether the state of NF-κB activation would influence the outcome of islet transplantation. Transgenic mice expressing a dominant active IKKβ (constitutively active or a non-degradable form of IκBα (constitutive inhibition under control of the rat insulin promoter were generated. Islets from these mice were transplanted into streptozotocin diabetic mice in suboptimal numbers. Further, the effects of salicylate (an inhibitor of NF-κB treatment of normal islets prior to transplantation, and the effects of salicylate administration to mice prior to and after islet implantation were evaluated. Transplantation outcomes were not affected using islets expressing a non-degradable form of IκBα when compared to wild type controls. However, the transplantation outcomes using islets isolated from mice expressing a constitutively active mutant of NF-κB were marginally worse, although no aberrations of islet function in vitro could be detected. Salicylate treatment of normal islets or mice had no effect on transplantation outcome. The current study draws attention to the complexities of NF-κB in pancreatic beta cells by suggesting that they can adapt with normal or near normal function to both chronic activation and inhibition of this important transcription factor.

  15. Islet and Stem Cell Encapsulation for Clinical Transplantation

    Science.gov (United States)

    Krishnan, Rahul; Alexander, Michael; Robles, Lourdes; Foster 3rd, Clarence E.; Lakey, Jonathan R.T.

    2014-01-01

    Over the last decade, improvements in islet isolation techniques have made islet transplantation an option for a certain subset of patients with long-standing diabetes. Although islet transplants have shown improved graft function, adequate function beyond the second year has not yet been demonstrated, and patients still require immunosuppression to prevent rejection. Since allogeneic islet transplants have experienced some success, the next step is to improve graft function while eliminating the need for systemic immunosuppressive therapy. Biomaterial encapsulation offers a strategy to avoid the need for toxic immunosuppression while increasing the chances of graft function and survival. Encapsulation entails coating cells or tissue in a semipermeable biocompatible material that allows for the passage of nutrients, oxygen, and hormones while blocking immune cells and regulatory substances from recognizing and destroying the cell, thus avoiding the need for systemic immunosuppressive therapy. Despite advances in encapsulation technology, these developments have not yet been meaningfully translated into clinical islet transplantation, for which several factors are to blame, including graft hypoxia, host inflammatory response, fibrosis, improper choice of biomaterial type, lack of standard guidelines, and post-transplantation device failure. Several new approaches, such as the use of porcine islets, stem cells, development of prevascularized implants, islet nanocoating, and multilayer encapsulation, continue to generate intense scientific interest in this rapidly expanding field. This review provides a comprehensive update on islet and stem cell encapsulation as a treatment modality in type 1 diabetes, including a historical outlook as well as current and future research avenues. PMID:25148368

  16. GLUT2 in pancreatic islets: crucial target molecule in diabetes induced with multiple low doses of streptozotocin in mice.

    Science.gov (United States)

    Wang, Z; Gleichmann, H

    1998-01-01

    In mice, diabetes can be induced by multiple low doses of streptozotocin (MLD-STZ), i.e., 40 mg/kg body wt on each of 5 consecutive days. In this model, diabetes develops only when STZ induces both beta-cell toxicity and T-cell-dependent immune reactions. The target molecule(s) of MLD-STZ-induced beta-cell toxicity are not known, however. In this study, we report that GLUT2 is a target molecule for MLD-STZ toxicity. Ex vivo, a gradual decrement of both GLUT2 protein and mRNA expression was found in pancreatic islets isolated from MLD-STZ-treated C57BL/6 male mice, whereas mRNA expression of beta-actin, glucokinase, and proinsulin remained unaffected. Significant reduction of both GLUT2 protein and mRNA expression was first noted 1 day after the third STZ injection, clearly preceding the onset of hyperglycemia. The extent of reduction increased with the number of STZ injections administered and increased over time, after the last, i.e., fifth, STZ injection. The STZ-induced reduction of GLUT2 protein and mRNA was not due to an essential loss of beta-cells, because ex vivo, not only the total RNA yield and protein content in isolated islets, but also proinsulin mRNA expression, failed to differ significantly in the differently treated groups. Furthermore, islets isolated from MLD-STZ-treated donors responded to the nonglucose secretagogue arginine in a pattern similar to that of solvent-treated donors. Interestingly, the MLD-STZ-induced reduction of both GLUT2 protein and mRNA was prevented by preinjecting mice with 5-thio-D-glucose before each STZ injection. Apparently, GLUT2 is a crucial target molecule of MLD-STZ toxicity, and this toxicity seems to precede the immune reactions against beta-cells.

  17. Protective efficacy of folic acid and vitamin B12 against nicotine-induced toxicity in pancreatic islets of the rat

    Directory of Open Access Journals (Sweden)

    Bhattacharjee Ankita

    2015-06-01

    Full Text Available Although cigarette smoking is associated with insulin resistance and an increased risk for type 2 diabetes, few studies have examined the effect of nicotine on the adult endocrine pancreas. In this study, male Wister rats were treated with nicotine (3 mg/kg body weight/day with or without supplementation of folic acid (36 μg/kg body weight/day or vitamin B12 (0.63 μg/kg body weight/day alone or in combination. Fasting blood glucose, insulin and HBA1C level and different oxidative and anti-oxidative stress parameters were measured and pancreatic tissue sections were stained with eosin-haematoxylene. Data were analysed by nonparametric statistics. The results revealed that nicotine induced prediabetes condition with subsequent damage to pancreatic islets in rats. Nicotine also caused oxidative stress in pancreatic tissue as evidenced by increased nitric oxide and malondialdehyde level and decreased superoxide dismutase, catalase and reduced glutathione level. Compared to vitamin B12 supplementation, folic acid blunted the nicotine-induced toxicity in pancreatic islets with higher efficacy. Further, folic acid and vitamin B12 in combination were able to confer significant protection on pancreatic islets against nicotine induced toxicity. These results suggest that supplementation of folic acid and vitamin B12 in combination may be a possible strategy of detoxification against nicotine-induced toxicity in pancreatic islets of the rat.

  18. 3H-cyclosporine internalization and secretion by human fetal pancreatic islets

    International Nuclear Information System (INIS)

    Formby, B.; Walker, L.; Peterson, C.M.

    1988-01-01

    Human fetal pancreatic islets were isolated from 16- to 20-week-old fetuses by a collagenase technique and cultured 48 hr in RPMI 1640 containing 10% human adult serum and unlabeled 0 to 5 micrograms cyclosporine A (CsA)/ml. Insulin secretory capacity of human fetal islets was expressed as a fractional stimulatory ratio FSR = F2/F1 of the fractional secretion rates during two successive 1 hr static incubations first with 2 mM glucose (F1) to stabilize secretion followed by maximal stimulus, i.e., 25 mM glucose plus 10 mM L-leucine and 10 mM L-arginine (F2). Unlabeled CsA at the above concentrations had no significant effects on the insulin secretory capacity expressed by FSR-values. Studies of net uptake of 3H-CsA by islets cultured for varying periods up to 40 hr and expressed as picomole 3H-CsA per picomole islet insulin content demonstrated that uptake rate was slow and did not reach isotopic equilibrium over the 40 hr of culture. When isolated fetal islets were cultured for 48 hr in the presence of 3H-CsA and varying concentrations of unlabeled CsA it was found during two successive 1 hr static incubations that fetal islets secrete insulin concomitantly with 3H-CsA following maximal stimulus for secretion. An optimal secretory molar ratio of 3H-CsA to insulin of 4.0 +/- 1.3 (n = 7) was found after islets were cultured 48 hr in the presence of a saturating 2.128 micrograms 3H-CsA per milliliter culture medium. In three successive 30-min static incubations of 3H-CsA loaded islets, first with low glucose, followed by high glucose plus L-arginine and L-leucine, and finally with high glucose plus L-arginine and L-leucine and 10 mM theophylline, the proportional fractional secretion rates of insulin and 3H-CsA were of the same magnitude

  19. Direct long-term effects of L-asparaginase on rat and human pancreatic islets

    DEFF Research Database (Denmark)

    Clausen, Niels; Nielsen, Jens Høiriis

    1989-01-01

    L-Asparaginase, an effective agent in the treatment of acute lymphoblastic leukemia, may induce a diabetic state. The pathogenesis of the diabetogenic effect was studied in cultured pancreatic islets. Mean serum concentrations in three children with acute lymphoblastic leukemia were 2.4 U/mL (range...... the glucagon content was unchanged. Removal of the drug resulted in partial recovery of the insulin secretion. To elucidate the mechanisms of of action of the drug, insulin biosynthesis was studied in islets cultured in asparagine-free medium with or without asparaginase. No difference in biosynthesis was seen...... between media with or without asparagine, whereas 0.1 U/mL asparaginase caused about a 50% reduction under both conditions.(ABSTRACT TRUNCATED AT 250 WORDS)...

  20. Generation of functional islets from human umbilical cord and placenta derived mesenchymal stem cells.

    Science.gov (United States)

    Kadam, Sachin; Govindasamy, Vijayendran; Bhonde, Ramesh

    2012-01-01

    Bone marrow-derived mesenchymal stem cells (BM-MSCs) have been used for allogeneic application in tissue engineering but have certain drawbacks. Therefore, mesenchymal stem cells (MSCs) derived from other adult tissue sources have been considered as an alternative. The human umbilical cord and placenta are easily available noncontroversial sources of human tissue, which are often discarded as biological waste, and their collection is noninvasive. These sources of MSCs are not subjected to ethical constraints, as in the case of embryonic stem cells. MSCs derived from umbilical cord and placenta are multipotent and have the ability to differentiate into various cell types crossing the lineage boundary towards endodermal lineage. The aim of this chapter is to provide a detailed reproducible cookbook protocol for the isolation, propagation, characterization, and differentiation of MSCs derived from human umbilical cord and placenta with special reference to harnessing their potential towards pancreatic/islet lineage for utilization as a cell therapy product. We show here that mesenchymal stromal cells can be extensively expanded from umbilical cord and placenta of human origin retaining their multilineage differentiation potential in vitro. Our report indicates that postnatal tissues obtained as delivery waste represent a rich source of mesenchymal stromal cells, which can be differentiated into functional islets employing three-stage protocol developed by our group. These islets could be used as novel in vitro model for screening hypoglycemics/insulin secretagogues, thus reducing animal experimentation for this purpose and for the future human islet transplantation programs to treat diabetes.

  1. Simultaneous determination of the content of serotonin, dopamine, noradrenaline and adrenaline in pancreatic islets isolated from fed and starved mice

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, S E; Hedeskov, C J [Copenhagen Univ. (Denmark)

    1977-01-01

    A highly sensitive double isotope method for the simultaneous determination of serotonin, dopamine, noradrenaline and adrenaline has been developed. Advantages and limitations of the method are discussed. The mentioned biogenic amines are all present in isolated pancreatic islet tissue from albino mice in concentrations ranging from approximately 5-30 ..mu..mol per kg wet weight (0.8-5 x 10/sup -3/ pmol/ng DNA). A somewhat higher content of these amines, especially dopamine, was found in pancreatic acinar tissue. The hypothesis that the impaired glucose-induced insulin secretion during starvation partly is caused by an increased content of biogenic amines in the pancreatic islets was not supported by our experiments which showed an unchanged islet content of these amines after 48 h starvation.

  2. Simultaneous determination of the content of serotonin, dopamine, noradrenaline and adrenaline in pancreatic islets isolated from fed and starved mice

    International Nuclear Information System (INIS)

    Hansen, S.E.; Hedeskov, C.J.

    1977-01-01

    A highly sensitive double isotope method for the simultaneous determination of serotonin, dopamine, noradrenaline and adrenaline has been developed. Advantages and limitations of the method are discussed. The mentioned biogenic amines are all present in isolated pancreatic islet tissue from albino mice in concentrations ranging from approximately 5-30 μmol per kg wet weight (0.8-5 x 10 -3 pmol/ng DNA). A somewhat higher content of these amines, especially dopamine, was found in pancreatic acinar tissue. The hypothesis that the impaired glucose-induced insulin secretion during starvation partly is caused by an increased content of biogenic amines in the pancreatic islets was not supported by our experiments which showed an unchanged islet content of these amines after 48 h starvation. (author)

  3. Nkx6.1 decline accompanies mitochondrial DNA reduction but subtle nucleoid size decrease in pancreatic islet beta-cells of diabetic Goto Kakizaki rats

    Czech Academy of Sciences Publication Activity Database

    Špaček, Tomáš; Pavluch, Vojtěch; Alán, Lukáš; Capková, Nikola; Engstová, Hana; Dlasková, Andrea; Berková, Z.; Saudek, F.; Ježek, Petr

    2017-01-01

    Roč. 7, Nov 15 (2017), č. článku 15674. ISSN 2045-2322 R&D Projects: GA ČR(CZ) GA13-02033S; GA ČR(CZ) GA13-06666S; GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:67985823 Keywords : GK rat * superresolution fluorescence * microscopy reveals * binding-protein * insulin -release Subject RIV: EA - Cell Biology OBOR OECD: Cell biology Impact factor: 4.259, year: 2016

  4. Autoreactive effector/memory CD4+ and CD8+ T cells infiltrating grafted and endogenous islets in diabetic NOD mice exhibit similar T cell receptor usage.

    Directory of Open Access Journals (Sweden)

    Ramiro Diz

    Full Text Available Islet transplantation provides a "cure" for type 1 diabetes but is limited in part by recurrent autoimmunity mediated by β cell-specific CD4(+ and CD8(+ T cells. Insight into the T cell receptor (TCR repertoire of effector T cells driving recurrent autoimmunity would aid the development of immunotherapies to prevent islet graft rejection. Accordingly, we used a multi-parameter flow cytometry strategy to assess the TCR variable β (Vβ chain repertoires of T cell subsets involved in autoimmune-mediated rejection of islet grafts in diabetic NOD mouse recipients. Naïve CD4(+ and CD8(+ T cells exhibited a diverse TCR repertoire, which was similar in all tissues examined in NOD recipients including the pancreas and islet grafts. On the other hand, the effector/memory CD8(+ T cell repertoire in the islet graft was dominated by one to four TCR Vβ chains, and specific TCR Vβ chain usage varied from recipient to recipient. Similarly, islet graft- infiltrating effector/memory CD4(+ T cells expressed a limited number of prevalent TCR Vβ chains, although generally TCR repertoire diversity was increased compared to effector/memory CD8(+ T cells. Strikingly, the majority of NOD recipients showed an increase in TCR Vβ12-bearing effector/memory CD4(+ T cells in the islet graft, most of which were proliferating, indicating clonal expansion. Importantly, TCR Vβ usage by effector/memory CD4(+ and CD8(+ T cells infiltrating the islet graft exhibited greater similarity to the repertoire found in the pancreas as opposed to the draining renal lymph node, pancreatic lymph node, or spleen. Together these results demonstrate that effector/memory CD4(+ and CD8(+ T cells mediating autoimmune rejection of islet grafts are characterized by restricted TCR Vβ chain usage, and are similar to T cells that drive destruction of the endogenous islets.

  5. ALK5 inhibition maintains islet endothelial cell survival but does not enhance islet graft revascularisation or function.

    Science.gov (United States)

    King, A J F; Clarkin, C E; Austin, A L F; Ajram, L; Dhunna, J K; Jamil, M O; Ditta, S I; Ibrahim, S; Raza, Z; Jones, P M

    2015-01-01

    Islet transplantation is a potential treatment for Type 1 diabetes but long term graft function is suboptimal. The rich supply of intraislet endothelial cells diminishes rapidly after islet isolation and culture, which affects the revascularisation rate of islets after transplantation. The ALK5 pathway inhibits endothelial cell proliferation and thus inhibiting ALK5 is a potential target for improving endothelial cell survival. The aim of the study was to establish whether ALK5 inhibition prevents the loss of intraislet endothelial cells during islet culture and thus improves the functional survival of transplanted islets by enhancing their subsequent revascularisation after implantation. Islets were cultured for 48 h in the absence or presence of 2 different ALK inhibitors: SB-431542 or A-83-01. Their vascular density after culture was analysed using immunohistochemistry. Islets pre-cultured with the ALK5 inhibitors were implanted into streptozotocin-diabetic mice for either 3 or 7 days and blood glucose concentrations were monitored and vascular densities of the grafts were analysed. Islets cultured with ALK5 inhibitors had higher vascular densities than control-cultured islets. Three days after implantation, endothelial cell numbers in islet grafts were minimal, irrespective of treatment during culture. Seven days after implantation, endothelial cells were evident within the islet grafts but there was no difference between control-cultured islets and islets pre-treated with an ALK5 inhibitor. Blood glucose concentrations were no different between the treatment groups. In conclusion, inhibition of ALK5 improved intraislet endothelial cell numbers after islet culture, but this effect was lost in the early post-transplantation period. © Georg Thieme Verlag KG Stuttgart · New York.

  6. Gene expression patterns in pancreatic tumors, cells and tissues.

    Directory of Open Access Journals (Sweden)

    Anson W Lowe

    2007-03-01

    Full Text Available Cancers of the pancreas originate from both the endocrine and exocrine elements of the organ, and represent a major cause of cancer-related death. This study provides a comprehensive assessment of gene expression for pancreatic tumors, the normal pancreas, and nonneoplastic pancreatic disease.DNA microarrays were used to assess the gene expression for surgically derived pancreatic adenocarcinomas, islet cell tumors, and mesenchymal tumors. The addition of normal pancreata, isolated islets, isolated pancreatic ducts, and pancreatic adenocarcinoma cell lines enhanced subsequent analysis by increasing the diversity in gene expression profiles obtained. Exocrine, endocrine, and mesenchymal tumors displayed unique gene expression profiles. Similarities in gene expression support the pancreatic duct as the origin of adenocarcinomas. In addition, genes highly expressed in other cancers and associated with specific signal transduction pathways were also found in pancreatic tumors.The scope of the present work was enhanced by the inclusion of publicly available datasets that encompass a wide spectrum of human tissues and enabled the identification of candidate genes that may serve diagnostic and therapeutic goals.

  7. Protective effect of ganoderma lucidum polysaccharides on pancreatic islet in type 2 diabetes mellitus rats

    International Nuclear Information System (INIS)

    Tang Zhigang; Xue Hua; Qiao Jin; Gu Jinhua; Xu Jiliang

    2010-01-01

    Objective: To investigate the protective effects of ganoderma lucidum polysaccharides (GLPs) on pancreatic islet in T2DM rats. Method: SD rats were fed high-fat diet for 4 weeks and then were injected STZ (30 mg/kg) to induce the type 2 diabetes mellitus(T2DM). Once the T2DM model were set successfully, rats were divided into six groups randomly: the normal group (NG), diabetes mellitus group (DMG), GPLs low dosage group (GLPs-LG), GPLs middle dosage group (GLPs-MG), GLPs high dosage group (GLPs-HG) and the berberine group (BerG). They received GLPs with different dosages (200, 400, or 800 mg/kg) and berberine (30 mg/kg) continually for 10 weeks. At 10th weekend, the following indexes of rats in each group were measured respectively: blood glucose, insulin sensivity index (ISI), the contents of NO, SOD, MDA, GSH-Px, CAT in pancreas tissue. At the same time pathological change of pancreas was evaluated by hematoxylin/eosin staining and immunohistochemistry of insulin. Result: As compared with the diabetic model, the decrease of blood glucose with GLPs treatment for 10 weeks were observed. There was also notably increased antioxidant enzyme activity such as superoxide dismutase (SOD), catalase (CAT) as well as decreased MDA content in the pancreatic homogenate. Under light microscope, GLPs-HG treated T2DM showed significantly ameliorated pathological changes, increased islet area and enhanced insulin staining intensity in islets. Conclusion: GLPs has protective effect on the STZ-induced islet injury in T2DM rats through increasing antioxidant enzyme activity and reducing oxidative stress. (authors)

  8. Surgical outcomes after total pancreatectomy and islet cell autotransplantation in pediatric patients.

    Science.gov (United States)

    Wilson, Gregory C; Sutton, Jeffrey M; Salehi, Marzieh; Schmulewitz, Nathan; Smith, Milton T; Kucera, Stephen; Choe, Kyuran A; Brunner, John E; Abbott, Daniel E; Sussman, Jeffrey J; Ahmad, Syed A

    2013-10-01

    This study aims to review surgical outcomes of pediatric patients undergoing total pancreatectomy with islet cell autotransplantation (TP/IAT) for the treatment of chronic pancreatitis (CP). All pediatric patients (≤18 years old) undergoing TP/IAT over a 10-year period (December 2002-June 2012) were identified for inclusion in a single-center, observational cohort study. Retrospective chart review was performed to identify pertinent preoperative, perioperative, and postoperative data, including narcotic usage, insulin requirements, etiology of pancreatitis, previous operative interventions, operative times, islet cell yields, duration of hospital stay, and overall quality of life. Quality of life was assessed using the Short Form-36 health questionnaire. Fourteen pediatric patients underwent TP/IAT for the treatment of CP at the University of Cincinnati with a mean age of 15.9 years (range, 14-18) and a mean body mass index of 21.8 kg/m(2) (range, 14-37). Of the patients, 50% (n = 7) were male and 29% had undergone previous pancreatic operations (1 each of Whipple, Puestow, Frey, and Berne procedures). Etiology of pancreatitis was idiopathic for 57% (n = 8); the remainder had identified genetic mutations predisposing to pancreatitis (CFTR, n = 4; SPINK1, n = 1; PRSS1, n = 1). Mean operative time was 532 minutes (range, 360-674) with an average hospital duration of stay of 16 days (range, 7-37). Islet cell isolation resulted in mean islet cell equivalents (IEQ) of 500,443 in patients without previous pancreatic surgery versus 413,671 IEQ in patients with prior pancreatic surgery (P = .12). Median patient follow-up was 9 months from surgery (range, 1-78). Preoperatively, patients required on average 32.7 morphine equivalent mg per day (MEQ), which improved to 13.9 MEQ at most recent follow-up. Eleven patients (79%) were narcotic independent. None of the patients were diabetic preoperatively. All of the patients were discharged after the operation with scheduled

  9. Cellular islet autoimmunity associates with clinical outcome of islet cell transplantation.

    Directory of Open Access Journals (Sweden)

    Volkert A L Huurman

    2008-06-01

    Full Text Available Islet cell transplantation can cure type 1 diabetes (T1D, but only a minority of recipients remains insulin-independent in the following years. We tested the hypothesis that allograft rejection and recurrent autoimmunity contribute to this progressive loss of islet allograft function.Twenty-one T1D patients received cultured islet cell grafts prepared from multiple donors and transplanted under anti-thymocyte globulin (ATG induction and tacrolimus plus mycophenolate mofetil (MMF maintenance immunosuppression. Immunity against auto- and alloantigens was measured before and during one year after transplantation. Cellular auto- and alloreactivity was assessed by lymphocyte stimulation tests against autoantigens and cytotoxic T lymphocyte precursor assays, respectively. Humoral reactivity was measured by auto- and alloantibodies. Clinical outcome parameters--including time until insulin independence, insulin independence at one year, and C-peptide levels over one year--remained blinded until their correlation with immunological parameters. All patients showed significant improvement of metabolic control and 13 out of 21 became insulin-independent. Multivariate analyses showed that presence of cellular autoimmunity before and after transplantation is associated with delayed insulin-independence (p = 0.001 and p = 0.01, respectively and lower circulating C-peptide levels during the first year after transplantation (p = 0.002 and p = 0.02, respectively. Seven out of eight patients without pre-existent T-cell autoreactivity became insulin-independent, versus none of the four patients reactive to both islet autoantigens GAD and IA-2 before transplantation. Autoantibody levels and cellular alloreactivity had no significant association with outcome.In this cohort study, cellular islet-specific autoimmunity associates with clinical outcome of islet cell transplantation under ATG-tacrolimus-MMF immunosuppression. Tailored immunotherapy targeting cellular

  10. Islet Cell Transplantation: MedlinePlus Health Topic

    Science.gov (United States)

    ... and Kidney Diseases) Learn More Beta Cell Breakthroughs (American Diabetes Association) Innovative Approaches to Treating Type 1 Diabetes Addressed in Beta-Cell Replacement Presentations (American Diabetes Association) Islet Transplantation (American Diabetes Association) Also in Spanish ...

  11. Hyaluronan and Hyaluronan-Binding Proteins Accumulate in Both Human Type 1 Diabetic Islets and Lymphoid Tissues and Associate With Inflammatory Cells in Insulitis

    Science.gov (United States)

    Bogdani, Marika; Johnson, Pamela Y.; Potter-Perigo, Susan; Nagy, Nadine; Day, Anthony J.; Bollyky, Paul L.

    2014-01-01

    Hyaluronan (HA) is an extracellular matrix glycosaminoglycan that is present in pancreatic islets, but little is known about its involvement in the development of human type 1 diabetes (T1D). We have evaluated whether pancreatic islets and lymphoid tissues of T1D and nondiabetic organ donors differ in the amount and distribution of HA and HA-binding proteins (hyaladherins), such as inter-α-inhibitor (IαI), versican, and tumor necrosis factor–stimulated gene-6 (TSG-6). HA was dramatically increased both within the islet and outside the islet endocrine cells, juxtaposed to islet microvessels in T1D. In addition, HA was prominent surrounding immune cells in areas of insulitis. IαI and versican were present in HA-rich areas of islets, and both molecules accumulated in diabetic islets and regions exhibiting insulitis. TSG-6 was observed within the islet endocrine cells and in inflammatory infiltrates. These patterns were only observed in tissues from younger donors with disease duration of <10 years. Furthermore, HA and IαI amassed in follicular germinal centers and in T-cell areas in lymph nodes and spleens in T1D patients compared with control subjects. Our observations highlight potential roles for HA and hyaladherins in the pathogenesis of diabetes. PMID:24677718

  12. Determination of Glutamic Acid Decarboxylase (GAD65 in Pancreatic Islets and Its In Vitro and In Vivo Degradation Kinetics in Serum Using a Highly Sensitive Enzyme Immunoassay

    Directory of Open Access Journals (Sweden)

    Michael Schlosser

    2008-01-01

    Full Text Available Glutamic acid decarboxylase GAD65 autoantibodies (GADA are an established marker for autoimmune diabetes. Recently, the autoantigen GAD65 itself was proposed as biomarker of beta-cell loss for prediction of autoimmune diabetes and graft rejection after islet transplantation. Therefore, the GAD65 content in pancreatic islets of different species and its serum degradation kinetics were examined in this study using a sensitive immunoassay. GAD65 was found in quantities of 78 (human, 43.7 (LEW.1A rat and 37.4 (BB/OK rat ng per 1,000 islets, respectively, but not in mouse islets. The in vitro half-life of porcine GAD65 and human recombinant GAD65 ranged from 1.27 to 2.35 hours at 37°C in human serum, plasma and blood, and was unaffected by presence of GAD65 autoantibodies. After injecting 2,000 ng recombinant human GAD65 into LEW.1A rats, the in vivo half-life was 2.77 hours. GAD65 was undetectable after 24 hours in these animals, and for up to 48 hours following diabetes induction by streptozotocin in LEW.1A rats. Estimated from these data, at least 13 islets in rat and 1,875 in human must be simultaneously destroyed to detect GAD65 in circulation. These results should be taken into consideration in further studies aimed at examining the diagnostic relevance of GAD65.

  13. Total Pancreatectomy (TP) and Islet Autotransplantation (IAT) for Chronic Pancreatitis (CP)

    Science.gov (United States)

    Sutherland, David E.R.; Radosevich, David M.; Bellin, Melena D.; Hering, Bernard J.; Beilman, Gregory J.; Dunn, Ty B.; Chinnakotla, Srinath; Vickers, Selwyn M.; Bland, Barbara; Balamurugan, A.N.; Freeman, Martin L.; Pruett, Timothy L.

    2013-01-01

    Background Total-pancreatectomy (TP) with intraportal-islet-auto-transplantation (IAT) can relieve pain and preserve beta-cell-mass in patients with chronic-pancreatitis (CP) when other-therapies fail. Reported is a >30-year-single-center-series. Study Design 409 patients (53 children, 5–18 yrs) with CP underwent TP-IAT from Feb/1977–Sept/2011; (etiology idiopathic-41%; SOD/biliary-9%; genetic-14%; divisum-17%; alcohol-7%; other-12%); mean age-35.3 yrs,); 74% female; prior-surgeries 21%--Puestow procedure 9%, Whipple 6%, distal pancreatectomy 7%; other 2%). Islet-function was classified as insulin-independent for those on no insulin; partial if known C-peptide positive or euglycemic on once-daily-insulin; and insulin-dependent if on standard basal–bolus diabetic regimen. An SF-36-survey for Quality-of-Life (QOL)) was completed before and in serial follow-up by patients done since 2007 with an integrated-survey that added in 2008. Results Actuarial-patient-survival post-TP-IAT was 96% in adults and 98% in children (1-year) and; 89% and 98% (5-years). Complications requiring relaparotomy occurred in 15.9%, bleeding (9.5%) being most common. IAT-function is achieved in 90% (C-peptide >0.6 ng/ml). At 3 years, 30% were insulin-independent (25% in adults, 55% in children) and 33% had partial-function. Mean HbA1C was 5000/kg (24%)] correlated with degree of function with insulin-independent rates at 3 yrs of 12, 22 and 72%, partial function 33, 62 and 24%. All patients had pain before TP-IAT and nearly all were on daily-narcotics. After TP-IAT, 85% had pain-improvement. By two years 59% had ceased-narcotics. All children were on narcotics before, 39% at follow-up; pain improved in 94%; 67% became pain-free. In the SF-36 survey, there was significant improvement from baseline in all dimensions including the Physical and Mental Component Summaries (P2/3 of patients with insulin-independence occurring in one-quarter of adults and half the children. PMID:22397977

  14. Stress-induced dissociations between intracellular calcium signaling and insulin secretion in pancreatic islets.

    Science.gov (United States)

    Qureshi, Farhan M; Dejene, Eden A; Corbin, Kathryn L; Nunemaker, Craig S

    2015-05-01

    In healthy pancreatic islets, glucose-stimulated changes in intracellular calcium ([Ca(2+)]i) provide a reasonable reflection of the patterns and relative amounts of insulin secretion. We report that [Ca(2+)]i in islets under stress, however, dissociates with insulin release in different ways for different stressors. Islets were exposed for 48h to a variety of stressors: cytokines (low-grade inflammation), 28mM glucose (28G, glucotoxicity), free fatty acids (FFAs, lipotoxicity), thapsigargin (ER stress), or rotenone (mitochondrial stress). We then measured [Ca(2+)]i and insulin release in parallel studies. Islets exposed to all stressors except rotenone displayed significantly elevated [Ca(2+)]i in low glucose, however, increased insulin secretion was only observed for 28G due to increased nifedipine-sensitive calcium-channel flux. Following 3-11mM glucose stimulation, all stressors substantially reduced the peak glucose-stimulated [Ca(2+)]i response (first phase). Thapsigargin and cytokines also substantially impacted aspects of calcium influx and ER calcium handling. Stressors did not significantly impact insulin secretion in 11mM glucose for any stressor, although FFAs showed a borderline reduction, which contributed to a significant decrease in the stimulation index (11:3mM glucose) observed for FFAs and also for 28G. We also clamped [Ca(2+)]i using 30mM KCl+250μM diazoxide to test the amplifying pathway. Only rotenone-treated islets showed a robust increase in 3-11mM glucose-stimulated insulin secretion under clamped conditions, suggesting that low-level mitochondrial stress might activate the metabolic amplifying pathway. We conclude that different stressors dissociate [Ca(2+)]i from insulin secretion differently: ER stressors (thapsigargin, cytokines) primarily affect [Ca(2+)]i but not conventional insulin secretion and 'metabolic' stressors (FFAs, 28G, rotenone) impacted insulin secretion. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Studies on alterations of the 86-rubidium efflux from rat pancreatic islets caused by thiol and thiol oxidants

    International Nuclear Information System (INIS)

    Wahl, M.A.

    1983-01-01

    The following findings were revealed by this study: 1) Oxidation-reduction (redox) of the intracellular system of glutathione influences the potassium efflux by way of an increase in the 86-rubidium efflux brought about by the oxidation of intracellular thiols. 2) The 86-rubidium efflux is not subject to change by oxidation of extracellular thiols located in the membrane, nor can it in any way be influenced by reduced glutathione of exogenous origin. 3) The potassium efflux from rat pancreatic islets, being generally known to trigger the electric activities of the beta-cell, is controlled by the oxidation-reduction of intracellular thiols rather than by that of extracellular thiols. (TRV) [de

  16. Use of additives, scaffolds and extracellular matrix components for improvement of human pancreatic islet outcomes in vitro: A systematic review.

    Science.gov (United States)

    Lemos, Natália Emerim; de Almeida Brondani, Letícia; Dieter, Cristine; Rheinheimer, Jakeline; Bouças, Ana Paula; Bauermann Leitão, Cristiane; Crispim, Daisy; Bauer, Andrea Carla

    2017-09-03

    Pancreatic islet transplantation is an established treatment to restore insulin independence in type 1 diabetic patients. Its success rates have increased lately based on improvements in immunosuppressive therapies and on islet isolation and culture. It is known that the quality and quantity of viable transplanted islets are crucial for the achievement of insulin independence and some studies have shown that a significant number of islets are lost during culture time. Thus, in an effort to improve islet yield during culture period, researchers have tested a variety of additives in culture media as well as alternative culture devices, such as scaffolds. However, due to the use of different categories of additives or devices, it is difficult to draw a conclusion on the benefits of these strategies. Therefore, the aim of this systematic review was to summarize the results of studies that described the use of medium additives, scaffolds or extracellular matrix (ECM) components during human pancreatic islets culture. PubMed and Embase repositories were searched. Of 5083 articles retrieved, a total of 37 articles fulfilled the eligibility criteria and were included in the review. After data extraction, articles were grouped as follows: 1) "antiapoptotic/anti-inflammatory/antioxidant," 2) "hormone," 3) "sulphonylureas," 4) "serum supplements," and 5) "scaffolds or ECM components." The effects of the reviewed additives, ECM or scaffolds on islet viability, apoptosis and function (glucose-stimulated insulin secretion - GSIS) were heterogeneous, making any major conclusion hard to sustain. Overall, some "antiapoptotic/anti-inflammatory/antioxidant" additives decreased apoptosis and improved GSIS. Moreover, islet culture with ECM components or scaffolds increased GSIS. More studies are needed to define the real impact of these strategies in improving islet transplantation outcomes.

  17. Cytokines and Pancreatic β-Cell Apoptosis

    DEFF Research Database (Denmark)

    Berchtold, L A; Prause, M; Størling, J

    2016-01-01

    The discovery 30 years ago that inflammatory cytokines cause a concentration, activity, and time-dependent bimodal response in pancreatic β-cell function and viability has been a game-changer in the fields of research directed at understanding inflammatory regulation of β-cell function and survival...... and the causes of β-cell failure and destruction in diabetes. Having until then been confined to the use of pathophysiologically irrelevant β-cell toxic chemicals as a model of β-cell death, researchers could now mimic endocrine and paracrine effects of the cytokine response in vitro by titrating concentrations...... of local, chronic islet inflammation. Since then, numerous studies have clarified how these bimodal responses depend on discrete signaling pathways. Most interest has been devoted to the proapoptotic response dependent upon mainly nuclear factor κ B and mitogen-activated protein kinase activation, leading...

  18. Effects of tetracaine on insulin release and calcium handling by rat pancreatic islets

    International Nuclear Information System (INIS)

    Abdel El Motal, S.M.A.; Pian-Smith, M.C.M.; Sharp, G.W.G.

    1987-01-01

    The effects of tetracaine on insulin release and 45 Ca 2+ handling by rat pancreatic islets have been studied under basal, glucose-stimulated, and 3-isobutyl-1-methylxanthine (IBMX)-stimulated conditions. Islets were isolated by the use of collagenase and used either directly (freshly isolated islets) or after a period under tissue culture conditions. Tetracaine was found to stimulate insulin release under basal conditions, to inhibit glucose-stimulated insulin release, and to potentiate insulin release stimulated by IBMX. In studies on the mechanisms underlying these effects, tetracaine was found to decrease glucose-stimulated net retention of 45 Ca 2+ (by an action to block the voltage-dependent Ca channels) and to mobilize Ca 2+ from intracellular stores. These two actions form the basis for the inhibition of glucose-stimulated insulin release, which depends heavily on Ca 2+ entry via the voltage-dependent channels and the synergism with IBMX to potentiate release. No inhibition of IBMX-stimulated release occurs because IBMX does not use the voltage-dependent channels to raise intracellular Ca 2+

  19. Pancreatic Islet Protein Complexes and Their Dysregulation in Type 2 Diabetes

    DEFF Research Database (Denmark)

    Pedersen, Helle Krogh; Gudmundsdottir, Valborg; Brunak, Søren

    2017-01-01

    Type 2 diabetes (T2D) is a complex disease that involves multiple genes. Numerous risk loci have already been associated with T2D, although many susceptibility genes remain to be identified given heritability estimates. Systems biology approaches hold potential for discovering novel T2D genes by ...... starting point when evaluating an individual's alterations at the genome, transcriptome, or proteome level in relation to T2D in clinical settings.......Type 2 diabetes (T2D) is a complex disease that involves multiple genes. Numerous risk loci have already been associated with T2D, although many susceptibility genes remain to be identified given heritability estimates. Systems biology approaches hold potential for discovering novel T2D genes...... by considering their biological context, such as tissue-specific protein interaction partners. Pancreatic islets are a key T2D tissue and many of the known genetic risk variants lead to impaired islet function, hence a better understanding of the islet-specific dysregulation in the disease-state is essential...

  20. An Exercise‐Only Intervention in Obese Fathers  Restores Glucose and Insulin Regulation in  Conjunction with the Rescue of Pancreatic Islet Cell  Morphology and MicroRNA Expression in Male  Offspring

    Directory of Open Access Journals (Sweden)

    Nicole O. McPherson

    2017-02-01

    Full Text Available Paternal obesity programs metabolic syndrome in offspring. Low‐impact exercise in obese  males improves the metabolic health of female offspring, however whether this occurred in male  offspring remained unknown. C57BL/6NHsd (Harlan mice were fed a control diet (CD; 6% fat, n =  7 or a high‐fat diet (HFD; 21% fat, n = 16 for 18 weeks. After 9 weeks, HFD‐fed mice either remained  sedentary (HH, n = 8 or undertook low–moderate exercise (HE, n = 8 for another 9 weeks. Male  offspring were assessed for glucose/insulin tolerance, body composition, plasma lipids, pancreatic  islet cell morphology and microRNA expression. Founder HH induced glucose intolerance, insulin  insensitivity, and hyperlipidaemia in male offspring (p < 0.05. Metabolic health was fully restored  in male offspring by founder exercise to control levels. Founder HH reduced pancreatic β‐cell area  and islet cell size in male offspring, and altered the expression of 13 pancreatic microRNAs (p <  0.05. Founder HE led to partial restoration of pancreatic islet cell morphology and the expression  of two pancreatic microRNAs (let7d‐5p, 194‐5p in male offspring. Founder HE reduced male  offspring adiposity, increased muscle mass, reduced plasma free fatty acids (FFAs, and further  altered pancreatic microRNAs (35 vs. HH; 32 vs. CD (p < 0.05. Low‐impact exercise in obese fathers  prior to conception, without dietary change, may be a viable intervention strategy to reduce the illeffects of obesity‐induced paternal programming in male offspring.

  1. Diffusion coefficient of alginate microcapsules used in pancreatic islet transplantation, a method to cure type 1 diabetes

    Science.gov (United States)

    Najdahmadi, Avid; Lakey, Jonathan R. T.; Botvinick, Elliot

    2018-02-01

    Pancreatic islet transplantation is a promising approach of providing insulin in type 1 diabetes. One strategy to protect islets from the host immune system is encapsulation within a porous biocompatible alginate membrane. This encapsulation provides mechanical support to the cells and allows selective diffusion of oxygen, nutrients and insulin while blocking immunoglobulins. These hydrogels form by diffusion of calcium ions into the polymer network and therefore they are highly sensitive to environmental changes and fluctuations in temperature. We investigated the effects of gel concentration, crosslinking time and ambient conditions on material permeability, volume, and rigidity, all of which may change the immunoisolating characteristics of alginate. To measure diffusion coefficient as a method to capture structural changes we studied the diffusion of fluorescently tagged dextrans of different molecular weight into the midplane of alginate microcapsules, the diffusion coefficient is then calculated by fitting observed fluorescence dynamics to the mathematical solution of 1-D diffusion into a sphere. These measurements were performed after incubation in different conditions as well as after an in vivo experiment in six immunocompetent mice for seven days. Additionally, the changes in gel volume after incubation at different temperatures and environmental conditions as well as changes in compression modulus of alginate gels during crosslinking were investigated. Our result show that increase of polymer concentration and crosslinking time leads to a decrease in volume and increase in compression modulus. Furthermore, we found that samples crosslinked and placed in physiological environment, experience an increase in volume. As expected, these volume changes affect diffusion rates of fluorescent dextrans, where volume expansion is correlated with higher calculated diffusion coefficient. This observation is critical to islet protection since higher permeability due

  2. Islet-cell dysfunction induced by glucocorticoid treatment

    DEFF Research Database (Denmark)

    van Raalte, Daniël H; Kwa, Kelly A A; van Genugten, Renate E

    2013-01-01

    Glucocorticoids impair glucose tolerance by inducing insulin resistance. We investigated the dose-dependent effects of glucocorticoid treatment on islet-cell function in healthy males and studied the role of the autonomic nervous system.......Glucocorticoids impair glucose tolerance by inducing insulin resistance. We investigated the dose-dependent effects of glucocorticoid treatment on islet-cell function in healthy males and studied the role of the autonomic nervous system....

  3. Ex vivo expanded human regulatory T cells delay islet allograft rejection via inhibiting islet-derived monocyte chemoattractant protein-1 production in CD34+ stem cells-reconstituted NOD-scid IL2rγnull mice.

    Science.gov (United States)

    Xiao, Fang; Ma, Liang; Zhao, Min; Huang, Guocai; Mirenda, Vincenzo; Dorling, Anthony; Lechler, Robert; Lombardi, Giovanna

    2014-01-01

    Type 1 diabetes mellitus (T1DM) is an autoimmune disease caused by immune-mediated destruction of insulin-secreting β cells of the pancreas. Near complete dependence on exogenous insulin makes T1DM very difficult to control, with the result that patients are exposed to high blood glucose and risk of diabetic complications and/or intermittent low blood glucose that can cause unconsciousness, fits and even death. Allograft transplantation of pancreatic islets restores normoglycemia with a low risk of surgical complications. However, although successful immediately after transplantation, islets are progressively lost, with most of the patients requiring exogenous insulin within 2 years post-transplant. Therefore, there is an urgent requirement for the development of new strategies to prevent islet rejection. In this study, we explored the importance of human regulatory T cells in the control of islets allograft rejection. We developed a pre-clinical model of human islet transplantation by reconstituting NOD-scid IL2rγnull mice with cord blood-derived human CD34+ stem cells and demonstrated that although the engrafted human immune system mediated the rejection of human islets, their survival was significantly prolonged following adoptive transfer of ex vivo expanded human Tregs. Mechanistically, Tregs inhibited the infiltration of innate immune cells and CD4+ T cells into the graft by down-regulating the islet graft-derived monocyte chemoattractant protein-1. Our findings might contribute to the development of clinical strategies for Treg therapy to control human islet rejection. We also show for the first time that CD34+ cells-reconstituted NOD-scid IL2rγnull mouse model could be beneficial for investigating human innate immunity in vivo.

  4. Ex Vivo Expanded Human Regulatory T Cells Delay Islet Allograft Rejection via Inhibiting Islet-Derived Monocyte Chemoattractant Protein-1 Production in CD34+ Stem Cells-Reconstituted NOD-scid IL2rγnull Mice

    Science.gov (United States)

    Xiao, Fang; Ma, Liang; Zhao, Min; Huang, Guocai; Mirenda, Vincenzo; Dorling, Anthony

    2014-01-01

    Type 1 diabetes mellitus (T1DM) is an autoimmune disease caused by immune-mediated destruction of insulin-secreting β cells of the pancreas. Near complete dependence on exogenous insulin makes T1DM very difficult to control, with the result that patients are exposed to high blood glucose and risk of diabetic complications and/or intermittent low blood glucose that can cause unconsciousness, fits and even death. Allograft transplantation of pancreatic islets restores normoglycemia with a low risk of surgical complications. However, although successful immediately after transplantation, islets are progressively lost, with most of the patients requiring exogenous insulin within 2 years post-transplant. Therefore, there is an urgent requirement for the development of new strategies to prevent islet rejection. In this study, we explored the importance of human regulatory T cells in the control of islets allograft rejection. We developed a pre-clinical model of human islet transplantation by reconstituting NOD-scid IL2rγnull mice with cord blood-derived human CD34+ stem cells and demonstrated that although the engrafted human immune system mediated the rejection of human islets, their survival was significantly prolonged following adoptive transfer of ex vivo expanded human Tregs. Mechanistically, Tregs inhibited the infiltration of innate immune cells and CD4+ T cells into the graft by down-regulating the islet graft-derived monocyte chemoattractant protein-1. Our findings might contribute to the development of clinical strategies for Treg therapy to control human islet rejection. We also show for the first time that CD34+ cells-reconstituted NOD-scid IL2rγnull mouse model could be beneficial for investigating human innate immunity in vivo. PMID:24594640

  5. Ex vivo expanded human regulatory T cells delay islet allograft rejection via inhibiting islet-derived monocyte chemoattractant protein-1 production in CD34+ stem cells-reconstituted NOD-scid IL2rγnull mice.

    Directory of Open Access Journals (Sweden)

    Fang Xiao

    Full Text Available Type 1 diabetes mellitus (T1DM is an autoimmune disease caused by immune-mediated destruction of insulin-secreting β cells of the pancreas. Near complete dependence on exogenous insulin makes T1DM very difficult to control, with the result that patients are exposed to high blood glucose and risk of diabetic complications and/or intermittent low blood glucose that can cause unconsciousness, fits and even death. Allograft transplantation of pancreatic islets restores normoglycemia with a low risk of surgical complications. However, although successful immediately after transplantation, islets are progressively lost, with most of the patients requiring exogenous insulin within 2 years post-transplant. Therefore, there is an urgent requirement for the development of new strategies to prevent islet rejection. In this study, we explored the importance of human regulatory T cells in the control of islets allograft rejection. We developed a pre-clinical model of human islet transplantation by reconstituting NOD-scid IL2rγnull mice with cord blood-derived human CD34+ stem cells and demonstrated that although the engrafted human immune system mediated the rejection of human islets, their survival was significantly prolonged following adoptive transfer of ex vivo expanded human Tregs. Mechanistically, Tregs inhibited the infiltration of innate immune cells and CD4+ T cells into the graft by down-regulating the islet graft-derived monocyte chemoattractant protein-1. Our findings might contribute to the development of clinical strategies for Treg therapy to control human islet rejection. We also show for the first time that CD34+ cells-reconstituted NOD-scid IL2rγnull mouse model could be beneficial for investigating human innate immunity in vivo.

  6. In Vivo Monitoring of Pancreatic β-Cells in a Transgenic Mouse Model

    Directory of Open Access Journals (Sweden)

    Steven J. Smith

    2006-04-01

    Full Text Available We generated a transgenic mouse model (RIP-luc for the in vivo monitoring of pancreatic islet mass and function in response to metabolic disease. Using the rat insulin promoter fused to firefly luciferase, and noninvasive technology to detect luciferase activity, we tracked changes in reporter signal during metabolic disease states and correlated the changes in luciferase signal with metabolic status of the mouse. Transgene expression was found to be specific to the pancreatic islets in this transgenic model. Basal transgene expression was tracked in male and female mice fed either a chow or a high-fat diet and in response to treatment with streptozotocin. Pancreatic bioluminescent signal increased in mice fed a high-fat diet compared with chow-fed animals. In a model of chemically induced diabetes, the bioluminescent signal decreased in accordance with the onset of diabetes and reduction of islet β-cell number. Preliminary studies using islets transplanted from this transgenic model suggest that in vivo image analysis can also be used to monitor transplanted islet viability and survival in the host. This transgenic model is a useful tool for in vivo studies of pancreatic β-cells and as a donor for islet transplantation studies.

  7. Angiographic diagnosis of a pancreatic islet tumor in a patient with the WDHA syndrome

    International Nuclear Information System (INIS)

    Inamoto, K.; Yoshino, F.; Nakao, N.; Kawanaka, M.

    1980-01-01

    A patient with an islet cell tumor of the pancreas that produced the watery diarrhea, hypokalemia, achlorhydria syndrome is presented. On celiac angiography an extremely vascular mass was seen in the body of pancreas with hypertrophied arteries and persistent, dense tumor staining. (orig.) [de

  8. Leucine metabolism in regulation of insulin secretion from pancreatic beta cells

    OpenAIRE

    Yang, Jichun; Chi, Yujing; Burkhardt, Brant R.; Guan, Youfei; Wolf, Bryan A

    2010-01-01

    Leucine, a the branched-chain amino acids that must be supplied in daily diet, plays an important role in controlling protein synthesis and regulating cell metabolism in various cell types. In pancreatic β cells, leucine acutely stimulates insulin secretion by serving as both metabolic fuel and allosteric activator of glutamate dehydrogenase to enhance glutaminolysis. Leucine has also been shown to regulate gene transcription and protein synthesis in pancreatic islet β cells via both mTOR-dep...

  9. Unraveling the effects of 1,25(OH)(2)D-3 on global gene expression in pancreatic islets

    DEFF Research Database (Denmark)

    Wolden-Kirk, H.; Overbergh, L.; Gysemans, C.

    2013-01-01

    Introduction: Vitamin D deficiency has been linked to type 1 and 2 diabetes, whereas supplementation may prevent both diseases. However, the extent of the effects of vitamin D or its metabolites directly on pancreatic islets is still largely unknown. The aim of the present study was to investigat...

  10. Morphological assessment of pancreatic islet hormone content following aerobic exercise training in rats with poorly controlled Type 1 diabetes mellitus.

    Science.gov (United States)

    McDonald, Matthew W; Murray, Michael R; Hall, Katharine E; Noble, Earl G; Melling, C W James

    2014-01-01

    Regular exercise has been shown to improve many complications of Type 1 diabetes mellitus (T1DM) including enhanced glucose tolerance and increased cardiac function. While exercise training has been shown to increase insulin content in pancreatic islets of rats with T1DM, experimental models were severely hyperglycemic and not undergoing insulin treatment. Further, research to date has yet to determine how exercise training alters glucagon content in pancreatic islets. The purpose of the present investigation was to determine the impact of a 10-week aerobic training program on pancreatic islet composition in insulin-treated rats with T1DM. Second, it was determined whether the acute, exercise-mediated reduction in blood glucose experienced in rats with T1DM would become larger in magnitude following aerobic exercise training. Diabetes was induced in male Sprague-Dawley rats by multiple low dose injections of streptozotocin (20mg/kg i.p.) and moderate intensity aerobic exercise training was performed on a motorized treadmill for one hour per day for a total of 10 weeks. Rats with T1DM demonstrated significantly less islet insulin, and significantly more islet glucagon hormone content compared with non-T1DM rats, which did not significantly change following aerobic training. The reduction in blood glucose in response to a single exercise bout was similar across 10 weeks of training. Results also support the view that different subpopulations of islets exist, as small islets (<50 μm diameter) had significantly more insulin and glucagon in rats with and without T1DM.

  11. Acute Exposure to a Precursor of Advanced Glycation End Products Induces a Dual Effect on the Rat Pancreatic Islet Function

    Directory of Open Access Journals (Sweden)

    Ghada Elmhiri

    2014-01-01

    Full Text Available Aim. Chronic diseases are the leading cause of death worldwide. Advanced glycation end products, known as AGEs, are a major risk factor for diabetes onset and maintenance. Methylglyoxal (MG, a highly reactive metabolite of glucose, is a precursor for the generation of endogenous AGEs. Methods. In this current study we incubated in vitro pancreatic islets from adult rats in absence or presence of MG (10 μmol/l with different concentrations of glucose and different metabolic components (acetylcholine, epinephrine, potassium, forskolin, and leucine. Results. Different effects of MG on insulin secretion were evidenced. In basal glucose stimulation (5.6 mM, MG induced a significant (P<0.05 increase of insulin secretion. By contrast, in higher glucose concentrations (8.3 mM and 16.7 mM, MG significantly inhibited insulin secretion (P<0.05. In the presence of potassium, forskolin, and epinephrine, MG enhanced insulin secretion (P<0.05, while when it was incubated with acetylcholine and leucine, MG resulted in a decrease of insulin secretion (P<0.05. Conclusion. We suggest that MG modulates the secretion activity of beta-cell depending on its level of stimulation by other metabolic factors. These results provide insights on a dual acute effect of MG on the pancreatic cells.

  12. Composition and function of macroencapsulated human embryonic stem cell-derived implants: comparison with clinical human islet cell grafts.

    Science.gov (United States)

    Motté, Evi; Szepessy, Edit; Suenens, Krista; Stangé, Geert; Bomans, Myriam; Jacobs-Tulleneers-Thevissen, Daniel; Ling, Zhidong; Kroon, Evert; Pipeleers, Daniel

    2014-11-01

    β-Cells generated from large-scale sources can overcome current shortages in clinical islet cell grafts provided that they adequately respond to metabolic variations. Pancreatic (non)endocrine cells can develop from human embryonic stem (huES) cells following in vitro derivation to pancreatic endoderm (PE) that is subsequently implanted in immune-incompetent mice for further differentiation. Encapsulation of PE increases the proportion of endocrine cells in subcutaneous implants, with enrichment in β-cells when they are placed in TheraCyte-macrodevices and predominantly α-cells when they are alginate-microencapsulated. At posttransplant (PT) weeks 20-30, macroencapsulated huES implants presented higher glucose-responsive plasma C-peptide levels and a lower proinsulin-over-C-peptide ratio than human islet cell implants under the kidney capsule. Their ex vivo analysis showed the presence of single-hormone-positive α- and β-cells that exhibited rapid secretory responses to increasing and decreasing glucose concentrations, similar to isolated human islet cells. However, their insulin secretory amplitude was lower, which was attributed in part to a lower cellular hormone content; it was associated with a lower glucose-induced insulin biosynthesis, but not with lower glucagon-induced stimulation, which together is compatible with an immature functional state of the huES-derived β-cells at PT weeks 20-30. These data support the therapeutic potential of macroencapsulated huES implants but indicate the need for further functional analysis. Their comparison with clinical-grade human islet cell grafts sets references for future development and clinical translation. Copyright © 2014 the American Physiological Society.

  13. Total Pancreatectomy and Islet Auto-Transplantation in Children for Chronic Pancreatitis. Indication, Surgical Techniques, Post Operative Management and Long-Term Outcomes

    Science.gov (United States)

    Chinnakotla, Srinath; Bellin, Melena D.; Schwarzenberg, Sarah J.; Radosevich, David M.; Cook, Marie; Dunn, Ty B.; Beilman, Gregory J.; Freeman, Martin L.; Balamurugan, A.N.; Wilhelm, Josh; Bland, Barbara; Jimenez-Vega, Jose M; Hering, Bernhard J.; Vickers, Selwyn M.; Pruett, Timothy L.; Sutherland, David E.R.

    2014-01-01

    Objective Describe the surgical technique, complications and long term outcomes of total pancreatectomy and islet auto transplantation (TP-IAT) in a large series of pediatric patients. Summary Background Data Surgical management of childhood pancreatitis is not clear; partial resection or drainage procedures often provide transient pain relief, but long term recurrence is common due to the diffuse involvement of the pancreas. Total pancreatectomy (TP) removes the source of the pain, while islet auto transplantation (IAT) potentially can prevent or minimize TP-related diabetes. Methods Retrospective review of 75 children undergoing TP-IAT for chronic pancreatitis who had failed medical, endoscopic or surgical treatment between 1989–2012. Results Pancreatitis pain and the severity of pain statistically improved in 90% of patients after TP-IAT (p =Puestow (p=0.018), lower body surface area (p=0.048), IEQ per Kg Body Weight (p=0.001) and total IEQ (100,000) (0.004) were associated with insulin independence. By multivariate analysis, 3 factors were associated with insulin independence after TP-IAT:(1) male gender, (2) lower body surface area and the (3) higher total IEQ per kilogram body weight. Total IEQ (100,000) was the single factor most strongly associated with insulin independence (OR = 2.62; p value < 0.001). Conclusions TP-IAT provides sustained pain relief and improved quality of life. The β cell function is dependent on islet yield. TP-IAT is an effective therapy for children with painful pancreatitis that fail medical and or endoscopic management PMID:24509206

  14. A mouse model for monitoring islet cell genesis and developing therapies for diabetes

    Directory of Open Access Journals (Sweden)

    Yoshinori Shimajiri

    2011-03-01

    Transient expression of the transcription factor neurogenin-3 marks progenitor cells in the pancreas as they differentiate into islet cells. We developed a transgenic mouse line in which the surrogate markers secreted alkaline phosphatase (SeAP and enhanced green florescent protein (EGFP can be used to monitor neurogenin-3 expression, and thus islet cell genesis. In transgenic embryos, cells expressing EGFP lined the pancreatic ducts. SeAP was readily detectable in embryos, in the media of cultured embryonic pancreases and in the serum of adult animals. Treatment with the γ-secretase inhibitor DAPT, which blocks Notch signaling, enhanced SeAP secretion rates and increased the number of EGFP-expressing cells as assayed by fluorescence-activated cell sorting (FACS and immunohistochemistry in cultured pancreases from embryos at embryonic day 11.5, but not in pancreases harvested 1 day later. By contrast, treatment with growth differentiation factor 11 (GDF11 reduced SeAP secretion rates. In adult mice, partial pancreatectomy decreased, whereas duct ligation increased, circulating SeAP levels. This model will be useful for studying signals involved in islet cell genesis in vivo and developing therapies that induce this process.

  15. The F-actin modifier villin regulates insulin granule dynamics and exocytosis downstream of islet cell autoantigen 512

    Directory of Open Access Journals (Sweden)

    Hassan Mziaut

    2016-08-01

    Full Text Available Objective: Insulin release from pancreatic islet β cells should be tightly controlled to avoid hypoglycemia and insulin resistance. The cortical actin cytoskeleton is a gate for regulated exocytosis of insulin secretory granules (SGs by restricting their mobility and access to the plasma membrane. Prior studies suggest that SGs interact with F-actin through their transmembrane cargo islet cell autoantigen 512 (Ica512 (also known as islet antigen 2/Ptprn. Here we investigated how Ica512 modulates SG trafficking and exocytosis. Methods: Transcriptomic changes in Ica512−/− mouse islets were analyzed. Imaging as well as biophysical and biochemical methods were used to validate if and how the Ica512-regulated gene villin modulates insulin secretion in mouse islets and insulinoma cells. Results: The F-actin modifier villin was consistently downregulated in Ica512−/− mouse islets and in Ica512-depleted insulinoma cells. Villin was enriched at the cell cortex of β cells and dispersed villin−/− islet cells were less round and less deformable. Basal mobility of SGs in villin-depleted cells was enhanced. Moreover, in cells depleted either of villin or Ica512 F-actin cages restraining cortical SGs were enlarged, basal secretion was increased while glucose-stimulated insulin release was blunted. The latter changes were reverted by overexpressing villin in Ica512-depleted cells, but not vice versa. Conclusion: Our findings show that villin controls the size of the F-actin cages restricting SGs and, thus, regulates their dynamics and availability for exocytosis. Evidence that villin acts downstream of Ica512 also indicates that SGs directly influence the remodeling properties of the cortical actin cytoskeleton for tight control of insulin secretion. Keywords: F-actin, Granules, Ica512, Insulin, Secretion, Villin

  16. Alteration in pancreatic islet function in human immunodeficiency virus

    DEFF Research Database (Denmark)

    Haugaard, Steen B

    2014-01-01

    Molecular mechanisms behind the defects in insulin production and secretion associated with antihuman immunodeficiency virus (anti-HIV) therapy and the development of HIV-associated lipodystrophy syndrome (HALS) are discussed in this article. Data suggesting insulin resistance on the beta cell...... and defects in first-phase insulin release of HALS patients are presented. Hepatic extraction of insulin, nonglucose insulin secretagogues and insulin-like growth factor release may exert influence on the demand of circulating insulin and on insulin secretion in HIV-infected patients. Finally, the paucity...

  17. Mesenchymal Stem Cells Enhance Allogeneic Islet Engraftment in Nonhuman Primates

    Science.gov (United States)

    Berman, Dora M.; Willman, Melissa A.; Han, Dongmei; Kleiner, Gary; Kenyon, Norman M.; Cabrera, Over; Karl, Julie A.; Wiseman, Roger W.; O'Connor, David H.; Bartholomew, Amelia M.; Kenyon, Norma S.

    2010-01-01

    OBJECTIVE To test the graft-promoting effects of mesenchymal stem cells (MSCs) in a cynomolgus monkey model of islet/bone marrow transplantation. RESEARCH DESIGN AND METHODS Cynomolgus MSCs were obtained from iliac crest aspirate and characterized through passage 11 for phenotype, gene expression, differentiation potential, and karyotype. Allogeneic donor MSCs were cotransplanted intraportally with islets on postoperative day (POD) 0 and intravenously with donor marrow on PODs 5 and 11. Recipients were followed for stabilization of blood glucose levels, reduction of exogenous insulin requirement (EIR), C-peptide levels, changes in peripheral blood T regulatory cells, and chimerism. Destabilization of glycemia and increases in EIR were used as signs of rejection; additional intravenous MSCs were administered to test the effect on reversal of rejection. RESULTS MSC phenotype and a normal karyotype were observed through passage 11. IL-6, IL-10, vascular endothelial growth factor, TGF-β, hepatocyte growth factor, and galectin-1 gene expression levels varied among donors. MSC treatment significantly enhanced islet engraftment and function at 1 month posttransplant (n = 8), as compared with animals that received islets without MSCs (n = 3). Additional infusions of donor or third-party MSCs resulted in reversal of rejection episodes and prolongation of islet function in two animals. Stable islet allograft function was associated with increased numbers of regulatory T-cells in peripheral blood. CONCLUSIONS MSCs may provide an important approach for enhancement of islet engraftment, thereby decreasing the numbers of islets needed to achieve insulin independence. Furthermore, MSCs may serve as a new, safe, and effective antirejection therapy. PMID:20622174

  18. Genetically Engineered Islets and Alternative Sources of Insulin-Producing Cells for Treating Autoimmune Diabetes: Quo Vadis?

    Directory of Open Access Journals (Sweden)

    Feng-Cheng Chou

    2012-01-01

    Full Text Available Islet transplantation is a promising therapy for patients with type 1 diabetes that can provide moment-to-moment metabolic control of glucose and allow them to achieve insulin independence. However, two major problems need to be overcome: (1 detrimental immune responses, including inflammation induced by the islet isolation/transplantation procedure, recurrence autoimmunity, and allorejection, can cause graft loss and (2 inadequate numbers of organ donors. Several gene therapy approaches and pharmaceutical treatments have been demonstrated to prolong the survival of pancreatic islet grafts in animal models; however, the clinical applications need to be investigated further. In addition, for an alternative source of pancreatic β-cell replacement therapy, the ex vivo generation of insulin-secreting cells from diverse origins of stem/progenitor cells has become an attractive option in regenerative medicine. This paper focuses on the genetic manipulation of islets during transplantation therapy and summarizes current strategies to obtain functional insulin-secreting cells from stem/progenitor cells.

  19. Glucose triggers protein kinase A-dependent insulin secretion in mouse pancreatic islets through activation of the K+ATP channel-dependent pathway

    DEFF Research Database (Denmark)

    Thams, Peter; Anwar, Mohammad R; Capito, Kirsten

    2005-01-01

    pancreatic islets was determined by radioimmunoassay. RESULTS: In islets cultured at 5.5 mmol/l glucose, and then perifused in physiological Krebs-Ringer medium, the PKA inhibitors, H89 (10 micromol/l) and PKI 6-22 amide (30 micromol/l) did not inhibit glucose (16.7 mmol/l)-induced insulin secretion...

  20. Relationship between insulin release and 65zinc efflux from rat pancreatic islets maintained in tissue culture

    International Nuclear Information System (INIS)

    Formby, B.; Schmid-Formby, F.; Grodsky, G.M.

    1984-01-01

    In short-term batch-incubation or perfusion experiments, we studied insulin release and associated 65 Zn efflux from rat pancreatic islets loaded with 65 Zn by 24-h tissue culture in low-glucose medium. The fractional basal insulin release and 65 Zn efflux were 0.4% and 3% of total content/h/islet, respectively. Thus, basal 65 Zn efflux was much greater than that to be accounted for if zinc was released proportionally with insulin release only; extragranular zinc flux was suggested. Two millimolar glucose, with or without 1 mM 3-isobutyl-1-methylxanthine (IBMX), affected neither insulin release nor associated 65 Zn efflux. Twenty-five millimolar glucose produced a significant threefold increase in insulin release above baseline, but somewhat decreased 65 Zn efflux at marginal significance. Glucose (25 mM) plus 1 mM IBMX provoked a high increase in insulin release and an associated 30% increase in fractional 65 Zn efflux over basal. Calculations based on previous estimations of 65 Zn distribution and equilibrium with islet zinc indicated that molar zinc efflux was more than sufficient to account for a 2-zinc-insulin hexamer. L-Leucine (2 or 20 mM) plus 1 mM IBMX caused far greater 65 Zn efflux for the amount of insulin released, indicating additional 65 Zn mobilization not directly related to insulin secretion. To evaluate 65 Zn efflux during inhibited insulin secretion, batch incubations were performed in 100% D 2 O or at 27 degrees C, conditions that inhibited insulin release stimulated by high glucose plus IBMX. These agents decreased the 65 Zn efflux far below the basal value (35% and 50%, respectively) and greater than could be accounted for by the attendent inhibition of insulin secretion.(ABSTRACT TRUNCATED AT 250 WORDS)

  1. Protein phosphorylation in pancreatic islets induced by 3-phosphoglycerate and 2-phosphoglycerate

    International Nuclear Information System (INIS)

    Pek, S.B.; Usami, Masaru; Bilir, N.; Fischer-Bovenkerk, C.; Ueda, Tetsufumi

    1990-01-01

    The authors have shown previously that 3-phosphoglycerate, which is a glycolytic metabolite of glucose, induces protein phosphorylation in bovine and rat brain and in rat heart, kidney, liver, lung, and whole pancreas. Since glycolytic metabolism of glucose is of paramount importance in insulin release, they considered the possibility that 3-phosphoglycerate may act as a coupling factor, and they searched for evidence for the existence of 3-phosphoglycerate-dependent protein phosphorylation systems in freshly isolated normal rat pancreatic islets. Membrane and cytosol fractions were incubated with [γ- 32 P]ATP and appropriate test substances and were subjected to NaDodSO 4 /PAGE and autoradiography. As little as 0.005 mM 3-phosphoglycerate or 2-phosphoglycerate stimulated the phosphorylation of 65-kDa cytosol protein by as early as 0.25 min. The phosphate bond of the 65-kDa phosphoprotein was sufficiently stable to withstand dialysis; the radioactivity could not be chased out by subsequent exposure to ATP, ADP, 3-phosphoglycerate, or 2,3-bisphosphoglycerate. Moreover, cAMP, cGMP, phorbol 12-myristate 13-acetate, or calcium failed to stimulate the phosphorylation of the 65-kDa protein. Phosphoglycerate-dependent protein phosphorylation in islets may have relevance to stimulation of insulin secretion

  2. 3-D Imaging Reveals Participation of Donor Islet Schwann Cells and Pericytes in Islet Transplantation and Graft Neurovascular Regeneration

    Directory of Open Access Journals (Sweden)

    Jyuhn-Huarng Juang

    2015-02-01

    Full Text Available The primary cells that participate in islet transplantation are the endocrine cells. However, in the islet microenvironment, the endocrine cells are closely associated with the neurovascular tissues consisting of the Schwann cells and pericytes, which form sheaths/barriers at the islet exterior and interior borders. The two cell types have shown their plasticity in islet injury, but their roles in transplantation remain unclear. In this research, we applied 3-dimensional neurovascular histology with cell tracing to reveal the participation of Schwann cells and pericytes in mouse islet transplantation. Longitudinal studies of the grafts under the kidney capsule identify that the donor Schwann cells and pericytes re-associate with the engrafted islets at the peri-graft and perivascular domains, respectively, indicating their adaptability in transplantation. Based on the morphological proximity and cellular reactivity, we propose that the new islet microenvironment should include the peri-graft Schwann cell sheath and perivascular pericytes as an integral part of the new tissue.

  3. Biotin enhances ATP synthesis in pancreatic islets of the rat, resulting in reinforcement of glucose-induced insulin secretion.

    Science.gov (United States)

    Sone, Hideyuki; Sasaki, Yuka; Komai, Michio; Toyomizu, Masaaki; Kagawa, Yasuo; Furukawa, Yuji

    2004-02-13

    Previous studies showed that biotin enhanced glucose-induced insulin secretion. Changes in the cytosolic ATP/ADP ratio in the pancreatic islets participate in the regulation of insulin secretion by glucose. In the present study we investigated whether biotin regulates the cytosolic ATP/ADP ratio in glucose-stimulated islets. When islets were stimulated with glucose plus biotin, the ATP/ADP ratio increased to approximately 160% of the ATP/ADP ratio in islets stimulated with glucose alone. The rate of glucose oxidation, assessed by CO(2) production, was also about 2-fold higher in islets treated with biotin. These increasing effects of biotin were proportional to the effects seen in insulin secretion. There are no previous reports of vitamins, such as biotin, directly affecting ATP synthesis. Our data indicate that biotin enhances ATP synthesis in islets following the increased rate of substrate oxidation in mitochondria and that, as a consequence of these events, glucose-induced insulin release is reinforced by biotin.

  4. Renin-angiotensin system blockers protect pancreatic islets against diet-induced obesity and insulin resistance in mice.

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    Eliete Dalla Corte Frantz

    Full Text Available BACKGROUND: The associations between obesity, hypertension and diabetes are well established, and the renin-angiotensin system (RAS may provide a link among them. The effect of RAS inhibition on type 2 diabetes is still unclear; however, RAS seems to play an important role in the regulation of the pancreas and glucose intolerance of mice fed high-fat (HF diet. METHODS: C57BL/6 mice fed a HF diet (8 weeks were treated with aliskiren (50 mg/kg/day, enalapril (30 mg/kg/day or losartan (10 mg/kg/day for 6 weeks, and the protective effects were extensively compared among groups by morphometry, stereological tools, immunostaining, Western blotting and hormonal analysis. RESULTS: All RAS inhibitors significantly attenuated the increased blood pressure in mice fed a HF diet. Treatment with enalapril, but not aliskiren or losartan, significantly attenuated body mass (BM gain, glucose intolerance and insulin resistance, improved the alpha and beta cell mass and prevented the reduction of plasma adiponectin. Furthermore, enalapril treatment improved the protein expression of the pancreatic islet Pdx1, GLUT2, ACE2 and Mas receptors. Losartan treatment showed the greatest AT2R expression. CONCLUSION: Our findings indicate that ACE inhibition with enalapril attenuated several of the deleterious effects of the HF diet. In summary, enalapril appears to be responsible for the normalization of islet morphology and function, of alpha and beta cell mass and of Pdx1 and GLUT2 expression. These protective effects of enalapril were attributed, primarily, to the reduction in body mass gain and food intake and the enhancement of the ACE2/Ang (1-7 /Mas receptor axis and adiponectin levels.

  5. Occurance of apoptosis during ischemia in porcine pancreas islet cells.

    Science.gov (United States)

    Stadlbauer, V; Schaffellner, S; Iberer, F; Lackner, C; Liegl, B; Zink, B; Kniepeiss, D; Tscheliessnigg, K H

    2003-03-01

    Pancreas islet transplantation is a potential treatment of diabetes mellitus and porcine organs provide an easily available source of cells. Unfortunately quality and quantity of isolated islets are still not satisfactory. Apoptosis occurs in freshly isolated islets and plays a significant role in early graft loss. We evaluated the influence of four storage solutions on porcine pancreas islets. After warm ischemia of 15-20 minutes 12 organs were stored in 4 cold preservation solutions: Histidine-Tryptophan-Ketoglutarate solution (HTK), Hank's buffered saline solution (HBSS), University of Wisconsin (UW) solution and Ringer-Lactate (R). After cold ischemia for 100 minutes, organs were fixed in 3% formalin. Apoptotic cells were counted on hematocylin-eosin stainings. Most apoptotic cells were found in organs stored in R. Low numbers were found in the other groups. The difference between organs stored in R and organs stored in UW, HTK, or HBSS was highly significant. No significant difference could be found between UW, HTK and HBSS. Cold and warm ischemia of the pancreas seems to induce apoptosis in islet cells. Preservation solutions cause less apoptosis than electrolyte solution. No significant differences could be found among the preservation solutions.

  6. Selective Osmotic Shock (SOS)-Based Islet Isolation for Microencapsulation.

    Science.gov (United States)

    Enck, Kevin; McQuilling, John Patrick; Orlando, Giuseppe; Tamburrini, Riccardo; Sivanandane, Sittadjody; Opara, Emmanuel C

    2017-01-01

    Islet transplantation (IT) has recently been shown to be a promising alternative to pancreas transplantation for reversing diabetes. IT requires the isolation of the islets from the pancreas, and these islets can be used to fabricate a bio-artificial pancreas. Enzymatic digestion is the current gold standard procedure for islet isolation but has lingering concerns. One such concern is that it has been shown to damage the islets due to nonselective tissue digestion. This chapter provides a detailed description of a nonenzymatic method that we are exploring in our lab as an alternative to current enzymatic digestion procedures for islet isolation from human and nonhuman pancreatic tissues. This method is based on selective destruction and protection of specific cell types and has been shown to leave the extracellular matrix (ECM) of islets intact, which may thus enhance islet viability and functionality. We also show that these SOS-isolated islets can be microencapsulated for transplantation.

  7. Supravital dithizone staining in the isolation of human and rat pancreatic islets

    DEFF Research Database (Denmark)

    Hansen, W A; Christie, M R; Kahn, R

    1989-01-01

    Dithizone, a zinc chelating agent, is known to selectively stain the islets of Langerhans in the pancreas. In the present study, we have used this stain to aid the identification of islets in material obtained by collagenase digestion of human pancreas. Islets were shown to rapidly and reversibly...... techniques for the large scale isolation of functionally intact human islets....

  8. Three-dimensional printed polymeric system to encapsulate human mesenchymal stem cells differentiated into islet-like insulin-producing aggregates for diabetes treatment

    Directory of Open Access Journals (Sweden)

    Omaima M Sabek

    2016-04-01

    Full Text Available Diabetes is one of the most prevalent, costly, and debilitating diseases in the world. Pancreas and islet transplants have shown success in re-establishing glucose control and reversing diabetic complications. However, both are limited by donor availability, need for continuous immunosuppression, loss of transplanted tissue due to dispersion, and lack of vascularization. To overcome the limitations of poor islet availability, here, we investigate the potential of bone marrow–derived mesenchymal stem cells differentiated into islet-like insulin-producing aggregates. Islet-like insulin-producing aggregates, characterized by gene expression, are shown to be similar to pancreatic islets and display positive immunostaining for insulin and glucagon. To address the limits of current encapsulation systems, we developed a novel three-dimensional printed, scalable, and potentially refillable polymeric construct (nanogland to support islet-like insulin-producing aggregates’ survival and function in the host body. In vitro studies showed that encapsulated islet-like insulin-producing aggregates maintained viability and function, producing steady levels of insulin for at least 4 weeks. Nanogland—islet-like insulin-producing aggregate technology here investigated as a proof of concept holds potential as an effective and innovative approach for diabetes cell therapy.

  9. Three-dimensional printed polymeric system to encapsulate human mesenchymal stem cells differentiated into islet-like insulin-producing aggregates for diabetes treatment.

    Science.gov (United States)

    Sabek, Omaima M; Farina, Marco; Fraga, Daniel W; Afshar, Solmaz; Ballerini, Andrea; Filgueira, Carly S; Thekkedath, Usha R; Grattoni, Alessandro; Gaber, A Osama

    2016-01-01

    Diabetes is one of the most prevalent, costly, and debilitating diseases in the world. Pancreas and islet transplants have shown success in re-establishing glucose control and reversing diabetic complications. However, both are limited by donor availability, need for continuous immunosuppression, loss of transplanted tissue due to dispersion, and lack of vascularization. To overcome the limitations of poor islet availability, here, we investigate the potential of bone marrow-derived mesenchymal stem cells differentiated into islet-like insulin-producing aggregates. Islet-like insulin-producing aggregates, characterized by gene expression, are shown to be similar to pancreatic islets and display positive immunostaining for insulin and glucagon. To address the limits of current encapsulation systems, we developed a novel three-dimensional printed, scalable, and potentially refillable polymeric construct (nanogland) to support islet-like insulin-producing aggregates' survival and function in the host body. In vitro studies showed that encapsulated islet-like insulin-producing aggregates maintained viability and function, producing steady levels of insulin for at least 4 weeks. Nanogland-islet-like insulin-producing aggregate technology here investigated as a proof of concept holds potential as an effective and innovative approach for diabetes cell therapy.

  10. Direct effect of gonadal and contraceptive steroids on insulin release from mouse pancreatic islets in organ culture

    DEFF Research Database (Denmark)

    Nielsen, Jens Høiriis

    1984-01-01

    Sex steroids are supposed to contribute to the normal glucose homeostasis and to the altered glucose and insulin metabolism in pregnancy and during contraception. In the present study isolated mouse pancreatic islets were maintained in tissue culture medium RPMI 1640 supplemented with 0.5% newborn...... calf serum and 100 ng/ml of one of the following steroids: oestradiol, progesterone, testosterone, megestrol acetate, medroxyprogesterone, chlormadinone acetate, norethynodrel, norethindrone acetate, and ethynyloestradiol. Release of insulin to the culture medium was measured during a 2 week culture...... in the presence of oestradiol, progesterone, or testosterone were subjected to 30 min stimulation with 5.5, 11, 22 mmol/l glucose, only the progesterone-treated islets released more insulin in response to glucose than the control islets. It is concluded that progesterone and its derivatives have a direct effect...

  11. Electrofusion of mesenchymal stem cells and islet cells for diabetes therapy: a rat model.

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    Goichi Yanai

    Full Text Available Islet transplantation is a minimally invasive treatment for severe diabetes. However, it often requires multiple donors to accomplish insulin-independence and the long-term results are not yet satisfying. Therefore, novel ways to overcome these problems have been explored. Isolated islets are fragile and susceptible to pro-apoptotic factors and poorly proliferative. In contrast, mesenchymal stem cells (MSCs are highly proliferative, anti-apoptotic and pluripotent to differentiate toward various cell types, promote angiogenesis and modulate inflammation, thereby studied as an enhancer of islet function and engraftment. Electrofusion is an efficient method of cell fusion and nuclear reprogramming occurs in hybrid cells between different cell types. Therefore, we hypothesized that electrofusion between MSC and islet cells may yield robust islet cells for diabetes therapy. We establish a method of electrofusion between dispersed islet cells and MSCs in rats. The fusion cells maintained glucose-responsive insulin release for 20 days in vitro. Renal subcapsular transplantation of fusion cells prepared from suboptimal islet mass (1,000 islets that did not correct hyperglycemia even if co-transplanted with MSCs, caused slow but consistent lowering of blood glucose with significant weight gain within the observation period in streptozotocin-induced diabetic rats. In the fusion cells between rat islet cells and mouse MSCs, RT-PCR showed new expression of both rat MSC-related genes and mouse β-cell-related genes, indicating bidirectional reprogramming of both β-cell and MSCs nuclei. Moreover, decreased caspase3 expression and new expression of Ki-67 in the islet cell nuclei suggested alleviated apoptosis and gain of proliferative capability, respectively. These results show that electrofusion between MSCs and islet cells yield special cells with β-cell function and robustness of MSCs and seems feasible for novel therapeutic strategy for diabetes

  12. Unstable Expression of Commonly Used Reference Genes in Rat Pancreatic Islets Early after Isolation Affects Results of Gene Expression Studies.

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    Lucie Kosinová

    Full Text Available The use of RT-qPCR provides a powerful tool for gene expression studies; however, the proper interpretation of the obtained data is crucially dependent on accurate normalization based on stable reference genes. Recently, strong evidence has been shown indicating that the expression of many commonly used reference genes may vary significantly due to diverse experimental conditions. The isolation of pancreatic islets is a complicated procedure which creates severe mechanical and metabolic stress leading possibly to cellular damage and alteration of gene expression. Despite of this, freshly isolated islets frequently serve as a control in various gene expression and intervention studies. The aim of our study was to determine expression of 16 candidate reference genes and one gene of interest (F3 in isolated rat pancreatic islets during short-term cultivation in order to find a suitable endogenous control for gene expression studies. We compared the expression stability of the most commonly used reference genes and evaluated the reliability of relative and absolute quantification using RT-qPCR during 0-120 hrs after isolation. In freshly isolated islets, the expression of all tested genes was markedly depressed and it increased several times throughout the first 48 hrs of cultivation. We observed significant variability among samples at 0 and 24 hrs but substantial stabilization from 48 hrs onwards. During the first 48 hrs, relative quantification failed to reflect the real changes in respective mRNA concentrations while in the interval 48-120 hrs, the relative expression generally paralleled the results determined by absolute quantification. Thus, our data call into question the suitability of relative quantification for gene expression analysis in pancreatic islets during the first 48 hrs of cultivation, as the results may be significantly affected by unstable expression of reference genes. However, this method could provide reliable information

  13. Alterations of pancreatic islet structure, metabolism and gene expression in diet-induced obese C57BL/6J mice.

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    Regan Roat

    Full Text Available The reduction of functional β cell mass is a key feature of type 2 diabetes. Here, we studied metabolic functions and islet gene expression profiles of C57BL/6J mice with naturally occurring nicotinamide nucleotide transhydrogenase (NNT deletion mutation, a widely used model of diet-induced obesity and diabetes. On high fat diet (HF, the mice developed obesity and hyperinsulinemia, while blood glucose levels were only mildly elevated indicating a substantial capacity to compensate for insulin resistance. The basal serum insulin levels were elevated in HF mice, but insulin secretion in response to glucose load was significantly blunted. Hyperinsulinemia in HF fed mice was associated with an increase in islet mass and size along with higher BrdU incorporation to β cells. The temporal profiles of glucose-stimulated insulin secretion (GSIS of isolated islets were comparable in HF and normal chow fed mice. Islets isolated from HF fed mice had elevated basal oxygen consumption per islet but failed to increase oxygen consumption further in response to glucose or carbonyl cyanide-4-trifluoromethoxyphenylhydrazone (FCCP. To obtain an unbiased assessment of metabolic pathways in islets, we performed microarray analysis comparing gene expression in islets from HF to normal chow-fed mice. A few genes, for example, those genes involved in the protection against oxidative stress (hypoxia upregulated protein 1 and Pgc1α were up-regulated in HF islets. In contrast, several genes in extracellular matrix and other pathways were suppressed in HF islets. These results indicate that islets from C57BL/6J mice with NNT deletion mutation develop structural, metabolic and gene expression features consistent with compensation and decompensation in response to HF diet.

  14. Expansion and conversion of human pancreatic ductal cells into insulin-secreting endocrine cells.

    Science.gov (United States)

    Lee, Jonghyeob; Sugiyama, Takuya; Liu, Yinghua; Wang, Jing; Gu, Xueying; Lei, Ji; Markmann, James F; Miyazaki, Satsuki; Miyazaki, Jun-Ichi; Szot, Gregory L; Bottino, Rita; Kim, Seung K

    2013-11-19

    Pancreatic islet β-cell insufficiency underlies pathogenesis of diabetes mellitus; thus, functional β-cell replacement from renewable sources is the focus of intensive worldwide effort. However, in vitro production of progeny that secrete insulin in response to physiological cues from primary human cells has proven elusive. Here we describe fractionation, expansion and conversion of primary adult human pancreatic ductal cells into progeny resembling native β-cells. FACS-sorted adult human ductal cells clonally expanded as spheres in culture, while retaining ductal characteristics. Expression of the cardinal islet developmental regulators Neurog3, MafA, Pdx1 and Pax6 converted exocrine duct cells into endocrine progeny with hallmark β-cell properties, including the ability to synthesize, process and store insulin, and secrete it in response to glucose or other depolarizing stimuli. These studies provide evidence that genetic reprogramming of expandable human pancreatic cells with defined factors may serve as a general strategy for islet replacement in diabetes. DOI: http://dx.doi.org/10.7554/eLife.00940.001.

  15. Separation of empty microcapsules after microencapsulation of porcine neonatal islets.

    Science.gov (United States)

    Shin, Soojeong; Yoo, Young Je

    2013-12-01

    Pancreatic islet transplantation is used to treat diabetes mellitus that has minimal complications and avoids hypoglycemic shock. Conformal microencapsulation of pancreatic islets improves their function by blocking immunogenic molecules while protecting fragile islets. However, production of empty alginate capsules during microencapsulation causes enlargement of the transplantation volume of the encapsulated islets and interferes with efficient transfer of nutrients and insulin. In this study, empty alginate capsules were separated after microencapsulation of neonatal porcine islet-like cell clusters (NPCC) using density-gradient centrifugation. Densities of NPCC and alginate capsules were determined using Percoll. Encapsulation products following alginate removal were 97 % of products, with less than 10 % of the capsules remaining empty. The viability of this process compared with manually-selected encapsulated islets indicates the separation process does not harm islets.

  16. A simple assay for the detection of antibodies to endocrine islet cell surface antigens

    International Nuclear Information System (INIS)

    Contreas, G.; Madsen, O.D.; Vissing, H.; Lernmark, Aa.

    1986-01-01

    A simple and sensitive immunoradiometric assay for the detection of islet cell surface antibodies (CIRMA) has been developed. Live, transformed islet cells derived from a liver metastasis of a transplantable islet cell tumor were grown in removable microtiter wells and incubated with antibody. Cell-bound antibodies were quantitated using 125 I-labelled second antibodies. The assay was used to detect islet cell antibodies present in sera from non-diabetic and diabetic BB rats and proved to be particularly effective for screening hybridoma supernatants in order to identify monoclonal antibodies recognizing islet cell surface antigens. (Auth.)

  17. Magnetic separation of encapsulated islet cells labeled with superparamagnetic iron oxide nano particles.

    Science.gov (United States)

    Mettler, Esther; Trenkler, Anja; Feilen, Peter J; Wiegand, Frederik; Fottner, Christian; Ehrhart, Friederike; Zimmermann, Heiko; Hwang, Yong Hwa; Lee, Dong Yun; Fischer, Stefan; Schreiber, Laura M; Weber, Matthias M

    2013-01-01

    Islet cell transplantation is a promising option for the restoration of normal glucose homeostasis in patients with type 1 diabetes. Because graft volume is a crucial issue in islet transplantations for patients with diabetes, we evaluated a new method for increasing functional tissue yield in xenogeneic grafts of encapsulated islets. Islets were labeled with three different superparamagnetic iron oxide nano particles (SPIONs; dextran-coated SPION, siloxane-coated SPION, and heparin-coated SPION). Magnetic separation was performed to separate encapsulated islets from the empty capsules, and cell viability and function were tested. Islets labeled with 1000 μg Fe/ml dextran-coated SPIONs experienced a 69.9% reduction in graft volume, with a 33.2% loss of islet-containing capsules. Islets labeled with 100 μg Fe/ml heparin-coated SPIONs showed a 46.4% reduction in graft volume, with a 4.5% loss of capsules containing islets. No purification could be achieved using siloxane-coated SPIONs due to its toxicity to the primary islets. SPION labeling of islets is useful for transplant purification during islet separation as well as in vivo imaging after transplantation. Furthermore, purification of encapsulated islets can also reduce the volume of the encapsulated islets without impairing their function by removing empty capsules. © 2013 John Wiley & Sons A/S.

  18. Pancreatic Cancer-Derived Exosomes Cause Paraneoplastic β-cell Dysfunction.

    Science.gov (United States)

    Javeed, Naureen; Sagar, Gunisha; Dutta, Shamit K; Smyrk, Thomas C; Lau, Julie S; Bhattacharya, Santanu; Truty, Mark; Petersen, Gloria M; Kaufman, Randal J; Chari, Suresh T; Mukhopadhyay, Debabrata

    2015-04-01

    Pancreatic cancer frequently causes diabetes. We recently proposed adrenomedullin as a candidate mediator of pancreatic β-cell dysfunction in pancreatic cancer. How pancreatic cancer-derived adrenomedullin reaches β cells remote from the cancer to induce β-cell dysfunction is unknown. We tested a novel hypothesis that pancreatic cancer sheds adrenomedullin-containing exosomes into circulation, which are transported to β cells and impair insulin secretion. We characterized exosomes from conditioned media of pancreatic cancer cell lines (n = 5) and portal/peripheral venous blood of patients with pancreatic cancer (n = 20). Western blot analysis showed the presence of adrenomedullin in pancreatic cancer-exosomes. We determined the effect of adrenomedullin-containing pancreatic cancer exosomes on insulin secretion from INS-1 β cells and human islets, and demonstrated the mechanism of exosome internalization into β cells. We studied the interaction between β-cell adrenomedullin receptors and adrenomedullin present in pancreatic cancer-exosomes. In addition, the effect of adrenomedullin on endoplasmic reticulum (ER) stress response genes and reactive oxygen/nitrogen species generation in β cells was shown. Exosomes were found to be the predominant extracellular vesicles secreted by pancreatic cancer into culture media and patient plasma. Pancreatic cancer-exosomes contained adrenomedullin and CA19-9, readily entered β cells through caveolin-mediated endocytosis or macropinocytosis, and inhibited insulin secretion. Adrenomedullin in pancreatic cancer exosomes interacted with its receptor on β cells. Adrenomedullin receptor blockade abrogated the inhibitory effect of exosomes on insulin secretion. β cells exposed to adrenomedullin or pancreatic cancer exosomes showed upregulation of ER stress genes and increased reactive oxygen/nitrogen species. Pancreatic cancer causes paraneoplastic β-cell dysfunction by shedding adrenomedullin(+)/CA19-9(+) exosomes into

  19. The hypothalamic satiety peptide CART is expressed in anorectic and non-anorectic pancreatic islet tumors and in the normal islet of Langerhans.

    Science.gov (United States)

    Jensen, P B; Kristensen, P; Clausen, J T; Judge, M E; Hastrup, S; Thim, L; Wulff, B S; Foged, C; Jensen, J; Holst, J J; Madsen, O D

    1999-03-26

    The hypothalamic satiety peptide CART (cocaine and amphetamine regulated transcript) is expressed at high levels in anorectic rat glucagonomas but not in hypoglycemic insulinomas. However, a non-anorectic metastasis derived from the glucagonoma retained high CART expression levels and produced circulating CART levels comparable to that of the anorectic tumors. Moreover, distinct glucagonoma lines derived by stable HES-1 transfection of the insulinoma caused severe anorexia but retained low circulating levels of CART comparable to that of insulinoma bearing or control rats. Islet tumor associated anorexia and circulating CART levels are thus not correlated, and in line with this peripheral administration of CART (5-50 mg/kg) produced no effect on feeding behavior. In the rat two alternatively spliced forms of CART mRNA exist and quantitative PCR revealed expression of both forms in the hypothalamus, in the different islet tumors, and in the islets of Langerhans. Immunocytochemistry as well as in situ hybridization localized CART expression to the somatostatin producing islet D cell. A potential endocrine/paracrine role of islet CART remains to be clarified.

  20. Histone deacetylases 1 and 3 but not 2 mediate cytokine-induced beta cell apoptosis in INS-1 cells and dispersed primary islets from rats and are differentially regulated in the islets of type 1 diabetic children

    DEFF Research Database (Denmark)

    Lundh, M; Christensen, D P; Damgaard Nielsen, M

    2012-01-01

    onset, HDAC1 was upregulated in beta cells whereas HDAC2 and -3 were downregulated in comparison with five paediatric controls. CONCLUSIONS/INTERPRETATION: These data demonstrate non-redundant functions of islet class I HDACs and suggest that targeting HDAC1 and HDAC3 would provide optimal protection......AIMS/HYPOTHESIS: Histone deacetylases (HDACs) are promising pharmacological targets in cancer and autoimmune diseases. All 11 classical HDACs (HDAC1-11) are found in the pancreatic beta cell, and HDAC inhibitors (HDACi) protect beta cells from inflammatory insults. We investigated which HDACs...... of HDAC1, -2 and -3 rescued INS-1 cells from inflammatory damage. Small hairpin RNAs against HDAC1 and -3, but not HDAC2, reduced pro-inflammatory cytokine-induced beta cell apoptosis in INS-1 and primary rat islets. The protective properties of specific HDAC knock-down correlated with attenuated cytokine...

  1. Effect of total lymphoid irradiation and pretransplant blood transfusion on pancreatic islet allograft survival

    International Nuclear Information System (INIS)

    Mendez-Picon, G.; McGeorge, M.

    1983-01-01

    Total lymphoid irradiation (TLI) has been shown to have a strong immunosuppressive effect both experimentally and clinically. Pretransplant blood transfusions have also been shown to have a strong beneficial effect in the outcome of organ transplantation. A study was made of the effect of TLI and pretransplant blood transfusions, alone and in combination, as an immunosuppressive modality in the isolated pancreatic islet transplant in the rat model. Donor rats (Fischer RT1v1) were kept on a 50% DL-ethionine supplemented diet for 4-6 weeks prior to pancreas removal. Recipient rats (Lewis RT1) were made diabetics prior to transplantation by iv injection of streptozotocin (45 mg/kg). Transfusion protocol consisted of a biweekly transfusion of 2 ml of either donor specific or third party transfusions. Total lymphoid irradiation was carried out by daily administration of 200 rads during one week prior to transplantation. Transplantation of the isolated islets was performed by intraportal injection. Syngeneic transplant of one and a half donor pancreata in each recipient reverted the diabetic condition indefinitely (greater than 100 days). Untreated allogenic grafts had a mean survival time (MST) of 5.2 days. Total lymphoid irradiation in dosages of 800, 1000, and 1200 rads, as the only immunosuppressive regimen, prolonged the MST of allografts to 15.3, 16.5, and 21.8 days, respectively (P less than .05). Pretransplant third party blood transfusion had no effect on allograft survival (MST 6.0). When donor specific blood transfusions were given, the MST was prolonged to 25.3 days (P less than .05). When TLI was administered to recipients of donor specific transfusions, the MST of the allografts did not show any statistical significant difference when compared with untreated animals. This abrogation of the beneficial effect of specific blood transfusion was observed in all dosages of TLI employed: 800 rad (MST 3.0), 1000 rad (MST 8.0), 1200 rad (MST 5.18)

  2. VEGF-conjugated alginate hydrogel prompt angiogenesis and improve pancreatic islet engraftment and function in type 1 diabetes

    International Nuclear Information System (INIS)

    Yin, Nina; Han, Yongming; Xu, Hanlin; Gao, Yisen; Yi, Tao; Yao, Jiale; Dong, Li; Cheng, Dejun; Chen, Zebin

    2016-01-01

    Type 1 diabetes was a life-long disease that affected numerous people around the world. Insulin therapy has its limitations that may involve hyperglycemia and heavy burden of patient by repeated dose. Islet transplantation emerged as a promising approach to reach periodical reverse of diabetes, however, transplanted islets suffer from foreign body reaction and lack of nutrition and oxygen supply, especially in the blood-vessel-shortage subcutaneous site which was preferred by patient and surgeon. In this study, we designed and synthesized a vascular endothelial growth factor (VEGF) conjugated alginate material to encapsulate the transplanted islets via 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide (EDC/NHS) reaction, and successful conjugation was confirmed by Nuclear Magnetic Resonance H1 spectrum. The best VEGF concentration (100 ng/ml) was determined by the combined studies of the mechanical property and endothelial cell growth assay. In vivo study, conjugated VEGF on alginate exhibited sustained promoting angiogenesis property after subcutaneous transplantation by histology study and islets encapsulated in this material achieved long term therapeutic effect (up to 50 days) in the diabetic mice model. In conclusion, this study establishes a simple biomaterial strategy for islet transplantation to enhance islet survival and function, which could be a feasible therapeutic alternative for type 1 diabetes. - Highlights: • We synthesized VEGF-conjugated alginate material to encapsulate the transplanted islets. • The biomaterials improve islet engraftment and function due to angiogenesis. • The biomaterials could be a strong support for cell therapy with islet transplantation in type 1 diabetes.

  3. VEGF-conjugated alginate hydrogel prompt angiogenesis and improve pancreatic islet engraftment and function in type 1 diabetes

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Nina; Han, Yongming [Department of Anatomy, Basic Medical College, Hubei University of Chinese Medicine, Wuhan, Hubei (China); Xu, Hanlin [Pharmacy Faculty, Hubei University of Chinese Medicine, Wuhan, Hubei (China); Gao, Yisen; Yi, Tao [Acupuncture and Moxibustion College, Hubei University of Chinese Medicine, Wuhan, Hubei (China); Yao, Jiale; Dong, Li; Cheng, Dejun [Basic Medical College, Hubei University of Chinese Medicine, Wuhan, Hubei (China); Chen, Zebin, E-mail: chenzebin-hbtcm@outlook.com [Acupuncture and Moxibustion College, Hubei University of Chinese Medicine/Hubei Provincial Collaborative Innovation Center of Preventive Treatment by Acupuncture and Moxibustion, Wuhan, Hubei (China)

    2016-02-01

    Type 1 diabetes was a life-long disease that affected numerous people around the world. Insulin therapy has its limitations that may involve hyperglycemia and heavy burden of patient by repeated dose. Islet transplantation emerged as a promising approach to reach periodical reverse of diabetes, however, transplanted islets suffer from foreign body reaction and lack of nutrition and oxygen supply, especially in the blood-vessel-shortage subcutaneous site which was preferred by patient and surgeon. In this study, we designed and synthesized a vascular endothelial growth factor (VEGF) conjugated alginate material to encapsulate the transplanted islets via 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide (EDC/NHS) reaction, and successful conjugation was confirmed by Nuclear Magnetic Resonance H1 spectrum. The best VEGF concentration (100 ng/ml) was determined by the combined studies of the mechanical property and endothelial cell growth assay. In vivo study, conjugated VEGF on alginate exhibited sustained promoting angiogenesis property after subcutaneous transplantation by histology study and islets encapsulated in this material achieved long term therapeutic effect (up to 50 days) in the diabetic mice model. In conclusion, this study establishes a simple biomaterial strategy for islet transplantation to enhance islet survival and function, which could be a feasible therapeutic alternative for type 1 diabetes. - Highlights: • We synthesized VEGF-conjugated alginate material to encapsulate the transplanted islets. • The biomaterials improve islet engraftment and function due to angiogenesis. • The biomaterials could be a strong support for cell therapy with islet transplantation in type 1 diabetes.

  4. Differentiation of human multipotent dermal fibroblasts into islet-like cell clusters

    Directory of Open Access Journals (Sweden)

    Liu Wei

    2010-06-01

    Full Text Available Abstract Background We have previously obtained a clonal population of cells from human foreskin that is able to differentiate into mesodermal, ectodermal and endodermal progenies. It is of great interest to know whether these cells could be further differentiated into functional insulin-producing cells. Results Sixty-one single-cell-derived dermal fibroblast clones were established from human foreskin by limiting dilution culture. Of these, two clones could be differentiated into neuron-, adipocyte- or hepatocyte-like cells under certain culture conditions. In addition, those two clones were able to differentiate into islet-like clusters under pancreatic induction. Insulin, glucagon and somatostatin were detectable at the mRNA and protein levels after induction. Moreover, the islet-like clusters could release insulin in response to glucose in vitro. Conclusions This is the first study to demonstrate that dermal fibroblasts can differentiate into insulin-producing cells without genetic manipulation. This may offer a safer cell source for future stem cell-based therapies.

  5. Islet neogenesis potential of human adult stem cells and its applications in cell replacement therapy for diabetes

    Directory of Open Access Journals (Sweden)

    Bhonde RR

    2008-11-01

    Full Text Available In recent years regenerative biology has reached to greater heights due to its therapeutic potential in treating degenerative diseases; as they are not curable by modern medicine. With the advent of research in stem cells and developmental biology the regenerative potential of adult resident stem cells is becoming clearer. The long term objective of regenerative medicine or cell therapy is to treat patients with their own stem cells. These stem cells could be derived from the diseased organs such as skin, liver, pancreas etc. or from reservoirs of multipotent stem cells such as bone marrow or cord blood.Manipulating the ability of tissue resident stem cells as well as from multipotent reservoirs such as bone marrow, umbilical cord and cord blood to give rise to endocrine cells may open new avenues in the treatment of diabetes. A better understanding of stem cell biology would almost certainly allow for the establishment of efficient and reliable cell transplantation experimental programs in the clinic. We show here that multipotent mesenchymal stem cells can be isolated from various sources such as the bone marrow, placenta, umbilical cord. Upon stimulation with specific growth factors they differentiate into islet like clusters (ILCs. When ILCs obtained from the above mentioned sources were transplanted in experimental diabetic mice, restoration of normoglycemia was observed within three weeks of transplantation with concomitant increase in the body weight. These euglycemic mice exhibited normal glucose tolerance test indicating normal utilization of glucose. Allthough the MSCs isolated from all the sources had the same characteristics; they showed significant differences in their islet differentiation potential. ILCs isolated for the human bone marrow did not show any pancreatic hormones in vitro, but upon transplantation they matured into insulin and somatostatin producing hormones. Placental MSCs as well as ILCs showed insulin trascripts

  6. Role of Natural Killer Cells in the Innate Immune System After Intraportal Islet Transplantation in Mice.

    Science.gov (United States)

    Saeki, Y; Ishiyama, K; Ishida, N; Tanaka, Y; Ohdan, H

    Both liver natural killer (NK) and NK T cells of the innate immune system play a crucial role in islet graft loss after intraportal islet transplantation, although a relationship between NK and NK T cells in islet loss has not been proven. In this study, we investigated the role of NK cells in the innate immune system in islet graft loss after intraportal islet transplantation. To investigate the involvement of liver NK cells in islet destruction, we assessed the differences in graft survival after intraportal islet transplantation between CD1d -/- diabetic mice and NK cell-depleted CD1d -/- diabetic mice. The transplantation of 400 islets into the liver was sufficient to reverse hyperglycemia in wild-type diabetic mice (100%, 4/4). However, normoglycemia could not be achieved when 200 islets were transplanted (0%, 0/4). In contrast, intraportal transplantation of 200 islets in NK cell-depleted CD1d -/- diabetic mice ameliorated hyperglycemia in 71% of cases (5/7), whereas transplantation of the same number of islets in CD1d -/- diabetic mice did not (0%, 0/4). Histologic findings also confirmed that intact islets were observed in NK cell-depleted CD1d -/- diabetic mice, but were difficult to observe in CD1d -/- diabetic mice. The involvement of liver NK cells in the innate immune system related to islet graft loss after intraportal islet transplantation is revealed by improved graft survival and function in NK cell-depleted CD1d -/- diabetic mice. Our data reveal that regulation of NK cell activity is particularly important when insufficient islet numbers are used for transplantation. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Integrative analysis of a cross-loci regulation network identifies App as a gene regulating insulin secretion from pancreatic islets.

    Directory of Open Access Journals (Sweden)

    Zhidong Tu

    Full Text Available Complex diseases result from molecular changes induced by multiple genetic factors and the environment. To derive a systems view of how genetic loci interact in the context of tissue-specific molecular networks, we constructed an F2 intercross comprised of >500 mice from diabetes-resistant (B6 and diabetes-susceptible (BTBR mouse strains made genetically obese by the Leptin(ob/ob mutation (Lep(ob. High-density genotypes, diabetes-related clinical traits, and whole-transcriptome expression profiling in five tissues (white adipose, liver, pancreatic islets, hypothalamus, and gastrocnemius muscle were determined for all mice. We performed an integrative analysis to investigate the inter-relationship among genetic factors, expression traits, and plasma insulin, a hallmark diabetes trait. Among five tissues under study, there are extensive protein-protein interactions between genes responding to different loci in adipose and pancreatic islets that potentially jointly participated in the regulation of plasma insulin. We developed a novel ranking scheme based on cross-loci protein-protein network topology and gene expression to assess each gene's potential to regulate plasma insulin. Unique candidate genes were identified in adipose tissue and islets. In islets, the Alzheimer's gene App was identified as a top candidate regulator. Islets from 17-week-old, but not 10-week-old, App knockout mice showed increased insulin secretion in response to glucose or a membrane-permeant cAMP analog, in agreement with the predictions of the network model. Our result provides a novel hypothesis on the mechanism for the connection between two aging-related diseases: Alzheimer's disease and type 2 diabetes.

  8. Pancreatic β-cells activate a JunB/ATF3-dependent survival pathway during inflammation

    DEFF Research Database (Denmark)

    Gurzov, E N; Barthson, J; Marhfour, I

    2012-01-01

    Destruction of insulin-producing pancreatic β-cells by local autoimmune inflammation is a hallmark of type 1 diabetes. Histochemical analysis of pancreases from non-obese diabetic mice indicated activation of the transcription factor JunB/AP-1 (activator protein-1) after autoimmune infiltration......-cells and human islet cells against pro-inflammatory mediators. These results were confirmed in genetically modified islets derived from Ubi-JunB transgenic mice. Our findings identify ATF3 as a novel downstream target of JunB in the survival mechanism of β-cells under inflammatory stress....

  9. Application of Rotating Wall Vessel (RWV) Cell Culture for Pancreas Islet Cell Transplantation

    Science.gov (United States)

    Rutzky, Lynne P.

    1998-01-01

    Type I insulin-dependent diabetes mellitus (IDDM) remains a major cause of morbidity and mortality in both pediatric and adult populations, despite significant advances in medical management. While insulin therapy treats symptoms of acute diabetes, it fails to prevent chronic complications such as microvascular disease, blindness, neuropathy, and chronic renal failure. Strict control of blood glucose concentrations delays but does not prevent the onset and progression of secondary complications. Although, whole pancreas transplantation restores physiological blood glucose levels, a continuous process of allograft rejection causes vascular and exocrine-related complications. Recent advances in methods for isolation and purification of pancreatic islets make transplantation of islet allografts an attractive alternative to whole pancreas transplantation. However, immunosuppressive drugs are necessary to prevent rejection of islet allografts and many of these drugs are known to be toxic to the islets. Since auto-transplants of isolated islets following total pancreatectomy survive and function in vivo, it is apparent that a major obstacle to successful clinical islet transplantation is the immunogenicity of the islet allografts.

  10. The effect of curcumin on insulin release in rat-isolated pancreatic islets.

    Science.gov (United States)

    Abdel Aziz, Mohamed T; El-Asmar, Mohamed F; El Nadi, Essam G; Wassef, Mohamed A; Ahmed, Hanan H; Rashed, Laila A; Obaia, Eman M; Sabry, Dina; Hassouna, Amira A; Abdel Aziz, Ahmed T

    2010-08-01

    Curcumin exerts a hypoglycemic action and induces heme-oxygenase-1 (HO-1). We evaluated the effect of curcumin on isolated islets of Langerhans and studied whether its action on insulin secretion is mediated by inducible HO-1. Islets were isolated from rats and divided into control islets, islets incubated in different curcumin concentrations, islets incubated in hemin, islets incubated in curcumin and HO inhibitor, stannous mesoporphyrin (SnMP), islets incubated in hemin and SnMP, islets incubated in SnMP only, and islets incubated in 16.7 mmol/L glucose. Heme-oxygenase activity, HO-1 expression, and insulin estimation was assessed. Insulin secretion, HO-1 gene expression and HO activity were significantly increased in islets incubated in curcumin, hemin, and glucose compared with controls. This increase in insulin secretion was significantly decreased by incubation of islets in SnMP. The action of curcumin on insulin secretion from the isolated islets may be, in part, mediated through increased HO-1 gene expression.

  11. Interaction of Glycolysis and Mitochondrial Respiration in Metabolic Oscillations of Pancreatic Islets

    DEFF Research Database (Denmark)

    Bertram, Richard; Satin, Leslie S.; Pedersen, Morten Gram

    2007-01-01

    Insulin secretion from pancreatic ß-cells is oscillatory, with a typical period of 2–7 min, reflecting oscillations in membrane potential and the cytosolic Ca2+ concentration. Our central hypothesis is that the slow 2–7 min oscillations are due to glycolytic oscillations, whereas faster oscillati...

  12. Serum Cytokines as Biomarkers in Islet Cell Transplantation for Type 1 Diabetes

    NARCIS (Netherlands)

    van der Torren, Cornelis R; Verrijn Stuart, Annemarie A; Lee, DaHae; Meerding, Jenny; van de Velde, Ursule; Pipeleers, Daniel; Gillard, Pieter; Keymeulen, Bart; de Jager, Wilco; Roep, Bart O

    2016-01-01

    BACKGROUND: Islet cell transplantation holds a potential cure for type 1 diabetes, but many islet recipients do not reach long-lasting insulin independence. In this exploratory study, we investigated whether serum cytokines, chemokines and adipokines are associated with the clinical outcome of islet

  13. Islet β cell failure in type 2 diabetes

    Science.gov (United States)

    Prentki, Marc; Nolan, Christopher J.

    2006-01-01

    The major focus of this Review is on the mechanisms of islet β cell failure in the pathogenesis of obesity-associated type 2 diabetes (T2D). As this demise occurs within the context of β cell compensation for insulin resistance, consideration is also given to the mechanisms involved in the compensation process, including mechanisms for expansion of β cell mass and for enhanced β cell performance. The importance of genetic, intrauterine, and environmental factors in the determination of “susceptible” islets and overall risk for T2D is reviewed. The likely mechanisms of β cell failure are discussed within the two broad categories: those with initiation and those with progression roles. PMID:16823478

  14. Transplantation of co-aggregates of Sertoli cells and islet cells into liver without immunosuppression.

    Science.gov (United States)

    Takemoto, Naohiro; Liu, Xibao; Takii, Kento; Teramura, Yuji; Iwata, Hiroo

    2014-02-15

    Transplantation of islets of Langerhans (islets) was used to treat insulin-dependent diabetes mellitus. However, islet grafts must be maintained by administration of immunosuppressive drugs, which can lead to complications in the long term. An approach that avoids immunosuppressive drug use is desirable. Co-aggregates of Sertoli cells and islet cells from BALB/c mice that were prepared by the hanging drop method were transplanted into C57BL/6 mouse liver through the portal vein as in human clinical islet transplantation. The core part of the aggregates contained mainly Sertoli cells, and these cells were surrounded by islet cells. The co-aggregates retained the functions of both Sertoli and islet cells. When 800 co-aggregates were transplanted into seven C57BL/6 mice via the portal vein, six of seven recipient mice demonstrated quasi-normoglycemia for more than 100 days. The hanging drop method is suitable for preparing aggregates of Sertoli and islet cells for transplantation. Notably, transplantation of these allogeneic co-aggregates into mice with chemically induced diabetes via the portal vein resulted in long-term graft survival without systemic immunosuppression.

  15. [Factors causing damage and destruction of beta-cells of the islets of Langerhans in the pancreas].

    Science.gov (United States)

    Anděl, Michal; Němcová, Vlasta; Pavlíková, Nela; Urbanová, Jana; Cecháková, Marie; Havlová, Andrea; Straková, Radka; Večeřová, Livia; Mandys, Václav; Kovář, Jan; Heneberg, Petr; Trnka, Jan; Polák, Jan

    2014-09-01

    Insulin secretion in patients with manifested diabetes mellitus tends to disappear months to decades after the diagnosis, which is a clear sign of a gradual loss of pancreatic islet beta-cells. In our sample of 30 type 2 diabetic patients, whose disease manifested between 30 and 45 years of age, about a half have retained or even increased insulin secretion 30 years later, while the other half exhibit a much diminished or lost insulin secretion. Factors that can damage or destroy beta-cells can be divided into the following groups: Metabolic factors: hyperglycemia and glucotoxicity, lipotoxicity, hypoxia, reactive oxygen species; Pharmacological factors: antimicrobial medication pentamidine, SSRI antidepressants; Factors related to impaired insulin secretion: MODY type diabetes; Environmental toxic factors: rat poison Vacor, streptozotocin, polychlorinated and polybrominated hydrocarbons; Disorders of the exocrine pancreas: tumor infiltration, fibrous infiltration, chronic pancreatitis, cystic fibrosis; Infections, inflammation, autoimmunity, viral factors: Coxsackie viruses, H1N1 influenza, enteroviruses. We are currently working on finding other factors leading to beta-cell damage, studying their effect on apoptosis and necrosis and looking for possible protective factors to prevent this damage. We our increasing knowledge about the mechanisms of beta-cell damage and destruction we come ever closer to suggest measures for their prevention. In this review we offer a brief and simplified summary of some of the findings related to this area.Key words: pancreatic islet beta-cells of Langerhans - factors damaging or destroying beta-cells - insulin secretion.

  16. Islet Cell Tumors of the Pancreas: A Variety of Multiphase Dynamic Imaging Findings with Pathologic Correlations Focusing on Nonfunctioning Tumors and Insulinomas

    International Nuclear Information System (INIS)

    Hong, Yoo Jin; Yu, Jeong Sik; Park, Chan Il; Kwon, Ji Eun; Chung, Jae Joon; Kim, Joo Hee; Kim, Ki Whang

    2010-01-01

    Islet cell tumors (ICTs) are rare pancreatic neoplasms of neuroendocrine origin, posing a diagnostic challenge to radiologists. We illustrated a spectrum of features of pancreatic ICTs that could be found on multiphase dynamic CT or MRI, and elucidated the histopathologic characteristics by determining the contrast enhancement pattern of the lesions. Various enhancement patterns were dependant on the internal composition of the tumor, that is, the proportion of vascular densities for early enhancement and non-hypervascular interstitial tissue for late enhancement regardless of the size or functional behavior. This knowledge of the imaging-pathologic spectrum of ICTs could be helpful for the proper differential diagnosis from other pancreatic tumors

  17. Downregulation of Type II Diabetes Mellitus and Maturity Onset Diabetes of Young Pathways in Human Pancreatic Islets from Hyperglycemic Donors

    Directory of Open Access Journals (Sweden)

    Jalal Taneera

    2014-01-01

    Full Text Available Although several molecular pathways have been linked to type 2 diabetes (T2D pathogenesis, it is uncertain which pathway has the most implication on the disease. Changes in the expression of an entire pathway might be more important for disease pathogenesis than changes in the expression of individual genes. To identify the molecular alterations in T2D, DNA microarrays of human pancreatic islets from donors with hyperglycemia n=20 and normoglycemia n=58 were subjected to Gene Set Enrichment Analysis (GSEA. About 178 KEGG pathways were investigated for gene expression changes between hyperglycemic donors compared to normoglycemic. Pathway enrichment analysis showed that type II diabetes mellitus (T2DM and maturity onset diabetes of the young (MODY pathways are downregulated in hyperglycemic donors, while proteasome and spliceosome pathways are upregulated. The mean centroid of gene expression of T2DM and MODY pathways was shown to be associated positively with insulin secretion and negatively with HbA1c level. To conclude, downregulation of T2DM and MODY pathways is involved in islet function and might be involved in T2D. Also, the study demonstrates that gene expression profiles from pancreatic islets can reveal some of the biological processes related to regulation of glucose hemostats and diabetes pathogenesis.

  18. Glucose and phosphate modulation of intracellular 45Ca incorporated into pancreatic islets during culture in the absence and presence of serum

    International Nuclear Information System (INIS)

    Bergsten, P.

    1985-01-01

    The effects of glucose and phosphate on the intracellular 45 Ca content were measured in β cell-rich pancreatic islets cultured in media containing or lacking serum. Irrespective of the glucose and serum concentrations there were no or very small increments of 45 Ca contents when phosphate was raised from 0.8 to 5.8 mM during culture for 1 day. However, after 7 days of culture in serum-free medium there was a massive accumulation of 45 Ca in the islets in response to the higher phosphate concentration. Glucose markedly reduced, and serum eliminated, the extensive accumulation probably due to increased cell viability. In the cells cultured in the presence of serum, raising the glucose concentration from 1.0 to 5.5 mM resulted in an increased incorporation of 45 Ca. This effect was particularly pronounced after culture for 7 days in 5.8 mM phosphate. A further increase of glucose to 20 mM reduced the 45 Ca content. The results are consistent with the concept that glucose both stimulates 45 Ca uptake into different β-cell pools and degranulates the cell with associated loss of intracellular calcium from the granular calcium pool. (author)

  19. Development of (99m)Tc-Labeled Pyridyl Benzofuran Derivatives To Detect Pancreatic Amylin in Islet Amyloid Model Mice.

    Science.gov (United States)

    Yoshimura, Masashi; Ono, Masahiro; Watanabe, Hiroyuki; Kimura, Hiroyuki; Saji, Hideo

    2016-06-15

    While islet amyloid deposition comprising amylin is one of pathological hallmarks of type 2 diabetes mellitus (T2DM), no useful amylin-imaging probe has been reported. In this study, we evaluated two (99m)Tc-labeled pyridyl benzofuran derivatives as novel amylin-imaging probes using the newly established islet amyloid model mouse. Binding experiments in vitro demonstrated that [(99m)Tc]1 displayed a higher affinity for amylin aggregates than [(99m)Tc]2. Autoradiographic studies using human pancreas sections with T2DM revealed that [(99m)Tc]1 clearly labeled islet amyloid in T2DM pancreatic sections, while [(99m)Tc]2 did not. Although the initial uptake of [(99m)Tc]1 by the normal mouse pancreas was low (0.74%ID/g at 2 min post-injection), [(99m)Tc]1 showed higher retention in the model mouse pancreas than that of the normal mouse, and exhibited strong binding to amylin aggregates in the living pancreas of the model mice. These results suggest that [(99m)Tc]1 is a potential imaging probe targeting islet amyloids in the T2DM pancreas.

  20. Hypothyroidism in utero stimulates pancreatic beta cell proliferation and hyperinsulinaemia in the ovine fetus during late gestation.

    Science.gov (United States)

    Harris, Shelley E; De Blasio, Miles J; Davis, Melissa A; Kelly, Amy C; Davenport, Hailey M; Wooding, F B Peter; Blache, Dominique; Meredith, David; Anderson, Miranda; Fowden, Abigail L; Limesand, Sean W; Forhead, Alison J

    2017-06-01

    Thyroid hormones are important regulators of growth and maturation before birth, although the extent to which their actions are mediated by insulin and the development of pancreatic beta cell mass is unknown. Hypothyroidism in fetal sheep induced by removal of the thyroid gland caused asymmetric organ growth, increased pancreatic beta cell mass and proliferation, and was associated with increased circulating concentrations of insulin and leptin. In isolated fetal sheep islets studied in vitro, thyroid hormones inhibited beta cell proliferation in a dose-dependent manner, while high concentrations of insulin and leptin stimulated proliferation. The developing pancreatic beta cell is therefore sensitive to thyroid hormone, insulin and leptin before birth, with possible consequences for pancreatic function in fetal and later life. The findings of this study highlight the importance of thyroid hormones during pregnancy for normal development of the fetal pancreas. Development of pancreatic beta cell mass before birth is essential for normal growth of the fetus and for long-term control of carbohydrate metabolism in postnatal life. Thyroid hormones are also important regulators of fetal growth, and the present study tested the hypotheses that thyroid hormones promote beta cell proliferation in the fetal ovine pancreatic islets, and that growth retardation in hypothyroid fetal sheep is associated with reductions in pancreatic beta cell mass and circulating insulin concentration in utero. Organ growth and pancreatic islet cell proliferation and mass were examined in sheep fetuses following removal of the thyroid gland in utero. The effects of triiodothyronine (T 3 ), insulin and leptin on beta cell proliferation rates were determined in isolated fetal ovine pancreatic islets in vitro. Hypothyroidism in the sheep fetus resulted in an asymmetric pattern of organ growth, pancreatic beta cell hyperplasia, and elevated plasma insulin and leptin concentrations. In pancreatic

  1. PEGylated bilirubin nanoparticle as an anti-oxidative and anti-inflammatory demulcent in pancreatic islet xenotransplantation.

    Science.gov (United States)

    Kim, Min Jun; Lee, Yonghyun; Jon, Sangyong; Lee, Dong Yun

    2017-07-01

    Transplanted islets suffer hypoxic stress, which leads to nonspecific inflammation. This is the major cause of islet graft failure during the early stage of intrahepatic islet transplantation. Although bilirubin has shown potent anti-oxidative and anti-inflammatory functions, its clinical applications have been limited due to its insolubility and short half-life. To overcome this problem, novel amphiphilic bilirubin nanoparticles are designed. Hydrophilic poly(ethylene glycol) (PEG) is conjugated to the hydrophobic bilirubin molecule. Then, the PEG-bilirubin conjugates form nanoparticles via self-assembly, i.e., so-called to BRNPs. BRNPs can protect islet cells not only from chemically induced oxidative stress by scavenging reactive oxygen species molecules, but also from activated macrophages by suppressing cytokine release. Importantly, in vivo experiments demonstrate that BRNP treatment can dramatically and significantly prolong islet graft survival compared to bilirubin treatment. In addition, immunohistochemical analysis shows BRNPs have potent anti-oxidative and anti-inflammatory capabilities. Collectively, novel BRNPs can be a new potent remedy for successful islet transplantation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Biosynthesis and release of thyrotropin-releasing hormone immunoreactivity in rat pancreatic islets in organ culture. Effects of age, glucose, and streptozotocin

    DEFF Research Database (Denmark)

    Dolva, L O; Welinder, B S; Hanssen, K F

    1983-01-01

    Thyrotropin-releasing hormone immunoreactivity (TRH-IR) was measured in isolated islets and in medium from rat pancreatic islets maintained in organ culture. TRH-IR in methanol extracts of both islets and culture medium was eluted in the same position as synthetic TRH by ion-exchange and gel...... chromatography and exhibited dilution curves parallel with synthetic TRH in radioimmunoassay. [3H]Histidine was incorporated into a component that reacted with TRH antiserum and had the same retention time as synthetic TRH on reversed-phase high-performance liquid chromatography. A continuous release of TRH...

  3. Antigen-Encoding Bone Marrow Terminates Islet-Directed Memory CD8+ T-Cell Responses to Alleviate Islet Transplant Rejection

    DEFF Research Database (Denmark)

    Coleman, Miranda; Jessup, Claire F.; Bridge, Jennifer A.

    2016-01-01

    in islet transplantation, and this will extend to application of personalized approaches using stem cell–derived replacement β-cells. New approaches are required to limit memory autoimmune attack of transplanted islets or replacement β-cells. Here, we show that transfer of bone marrow encoding cognate......Islet-specific memory T cells arise early in type 1 diabetes (T1D), persist for long periods, perpetuate disease, and are rapidly reactivated by islet transplantation. As memory T cells are poorly controlled by “conventional” therapies, memory T cell–mediated attack is a substantial challenge......-cell responses, and this can alleviate destruction of antigen-expressing islets. This addresses a key challenge facing islet transplantation and, importantly, the clinical application of personalized β-cell replacement therapies using patient-derived stem cells....

  4. Cancer Stem Cells in Pancreatic Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Bao, Qi; Zhao, Yue; Renner, Andrea; Niess, Hanno; Seeliger, Hendrik; Jauch, Karl-Walter; Bruns, Christiane J., E-mail: christiane.bruns@med.uni-muenchen.de [Department of Surgery, Ludwig Maximilian University of Munich, Klinikum Grosshadern, Marchioninistr. 15, D-81377, Munich (Germany)

    2010-08-19

    Pancreatic cancer is an aggressive malignant solid tumor well-known by early metastasis, local invasion, resistance to standard chemo- and radiotherapy and poor prognosis. Increasing evidence indicates that pancreatic cancer is initiated and propagated by cancer stem cells (CSCs). Here we review the current research results regarding CSCs in pancreatic cancer and discuss the different markers identifying pancreatic CSCs. This review will focus on metastasis, microRNA regulation and anti-CSC therapy in pancreatic cancer.

  5. Cancer Stem Cells in Pancreatic Cancer

    Science.gov (United States)

    Bao, Qi; Zhao, Yue; Renner, Andrea; Niess, Hanno; Seeliger, Hendrik; Jauch, Karl-Walter; Bruns, Christiane J.

    2010-01-01

    Pancreatic cancer is an aggressive malignant solid tumor well-known by early metastasis, local invasion, resistance to standard chemo- and radiotherapy and poor prognosis. Increasing evidence indicates that pancreatic cancer is initiated and propagated by cancer stem cells (CSCs). Here we review the current research results regarding CSCs in pancreatic cancer and discuss the different markers identifying pancreatic CSCs. This review will focus on metastasis, microRNA regulation and anti-CSC therapy in pancreatic cancer. PMID:24281178

  6. Cancer Stem Cells in Pancreatic Cancer

    Directory of Open Access Journals (Sweden)

    Karl-Walter Jauch

    2010-08-01

    Full Text Available Pancreatic cancer is an aggressive malignant solid tumor well-known by early metastasis, local invasion, resistance to standard chemo- and radiotherapy and poor prognosis. Increasing evidence indicates that pancreatic cancer is initiated and propagated by cancer stem cells (CSCs. Here we review the current research results regarding CSCs in pancreatic cancer and discuss the different markers identifying pancreatic CSCs. This review will focus on metastasis, microRNA regulation and anti-CSC therapy in pancreatic cancer.

  7. Beneficial effect of 17β-estradiol on hyperglycemia and islet β-cell functions in a streptozotocin-induced diabetic rat model

    International Nuclear Information System (INIS)

    Yamabe, Noriko; Kang, Ki Sung; Zhu Baoting

    2010-01-01

    The modulating effect of estrogen on glucose homeostasis remains a controversial issue at present. In this study, we sought to determine the beneficial effect of 17β-estradiol (E 2 ) on hyperglycemia and islet β-cell functions in streptozotocin (STZ)-induced diabetic rats. Male Sprague-Dawley rats were injected i.p. with STZ to induce a relatively mild diabetic condition. The rats were then treated with E 2 orally at 500 μg/kg body weight/day for 15 days to evaluate the modulating effect on hyperglycemia, insulin secretion, and islet β-cell proliferation. E 2 administration for 10 days significantly lowered plasma glucose levels, increased plasma insulin levels, and improved glucose tolerance by attenuating insulin response to oral glucose loading. These beneficial effects of E 2 were accompanied by increases in islet number and volume, rate of islet cell proliferation, and the amount of insulin secreted. The growth-stimulatory effect of E 2 on islet cells was linked to the functions of the estrogen receptor α. Notably, these protective effects of E 2 on diabetic conditions were basically not observed when the STZ-treated rats had a more severe degree of islet damage and hyperglycemia. Taken together, we conclude that E 2 can promote the regeneration of damaged pancreatic islets by stimulating β-cell proliferation in diabetic rats, and this effect is accompanied by improvements in glucose tolerance and a decrease in plasma glucose levels. These findings suggest that oral administration of E 2 may be beneficial in diabetic patients with an accelerated loss of islet β-cells.

  8. UCP2 mRNA expression is dependent on glucose metabolism in pancreatic islets

    DEFF Research Database (Denmark)

    Dalgaard, Louise Torp

    2012-01-01

    Uncoupling Protein 2 (UCP2) is expressed in the pancreatic β-cell, where it partially uncouples the mitochondrial proton gradient, decreasing both ATP-production and glucose-stimulated insulin secretion (GSIS). Increased glucose levels up-regulate UCP2 mRNA and protein levels, but the mechanism f...... down-regulation of UCP2 is involved in preserving the insulin secretory capacity of GK mutant mice and might also be implicated in limiting disease progression in MODY2 patients....

  9. Specifying pancreatic endocrine cell fates.

    Science.gov (United States)

    Collombat, Patrick; Hecksher-Sørensen, Jacob; Serup, Palle; Mansouri, Ahmed

    2006-07-01

    Cell replacement therapy could represent an attractive alternative to insulin injections for the treatment of diabetes. However, this approach requires a thorough understanding of the molecular switches controlling the specification of the different pancreatic cell-types in vivo. These are derived from an apparently identical pool of cells originating from the early gut endoderm, which are successively specified towards the pancreatic, endocrine, and hormone-expressing cell lineages. Numerous studies have outlined the crucial roles exerted by transcription factors in promoting the cell destiny, defining the cell identity and maintaining a particular cell fate. This review focuses on the mechanisms regulating the morphogenesis of the pancreas with particular emphasis on recent findings concerning the transcription factor hierarchy orchestrating endocrine cell fate allocation.

  10. Impact of adverse pancreatic injury at surgical procurement upon islet isolation outcome.

    Science.gov (United States)

    Andres, Axel; Kin, Tatsuya; O'Gorman, Doug; Bigam, David; Kneteman, Norman; Senior, Peter; Shapiro, Am James

    2014-11-01

    The consequence of a pancreas injury during the procurement for islet isolation purpose is unknown. The goal of this work was to assess the injuries of the pancreata procured for islet isolation, and to determine their effect on the islet yield. Between January 2007 and October 2013, we prospectively documented every injury of the pancreata processed in our centre for islet isolation. Injuries involving the main duct were classified as major, the others as minor. Donors' characteristics and islet yields were compared between the groups of injuries. A pancreas injury was identified in 42 of 452 pancreata received for islet isolation (9.3%). In 15 cases, the injury was major (3.3% of all pancreata). Although a minor injury did not affect the islet yield, a major injury was significantly associated with unfavourable outcomes (postpurification mean islet equivalent of 364 ± 181, 405 ± 190 and 230 ± 115 × 10(3) for absence of injury, minor injury and major injury, respectively). A major injury was significantly more prevalent in lean and short donors. We recommend assessing the quality of the pancreas in the islet isolation centre before starting the isolation procedure. Each centre should determine its own policy based on its financial resources and on the wait list. © 2014 Steunstichting ESOT.

  11. Islets of Langerhans in the parakeet, Psittacula krameri.

    Science.gov (United States)

    Gupta, Y K; Kumar, S

    1980-01-01

    The pancreatic gland of Psittacula krameri is divisible into 4 lobes i.e. dorsal, ventral, third and splenic. The endocrine part is composed of alpha 1-, alpha 2- and beta-cells. The islets are of 4 kinds viz., alpha islets (having alpha 1- and alpha 2-cells), beta islets (having beta- and alpha 1-cells), pure beta islets (consisting of beta-cells exclusively) and mixed islets (with beta-, alpha 1- and alpha 2-cells). The distribution of alpha islets is mostly restricted to the splenic and third lobes whereas the beta islets are found in all 4 lobes. Though the alpha islets are only few in the dorsal lobe, their size is best developed in the third and dorsal lobes. Sometimes beta and alpha islets are present in very close proximity but their cells never mingle. An interesting feature was the complete absence of alpha islets from the ventral lobe.A relative abundance of alpha 2- cells in this bird seems to be associated with its comparatively higher blood glucose level and frugivorous habit. Tinctorial reactions suggest that the insulin content of the endocrine pancreas is low. There were no seasonal changes in the islet tissue of P. krameri.

  12. Activin receptor-like kinase 5 inhibition reverses impairment of endothelial cell viability by endogenous islet mesenchymal stromal cells.

    Science.gov (United States)

    Clarkin, Claire E; King, Aileen J; Dhadda, Paramjeet; Chagastelles, Pedro; Nardi, Nance; Wheeler-Jones, Caroline P; Jones, Peter M

    2013-03-01

    Following islet transplantation, islet graft revascularization is compromised due to loss of endothelial cells (ECs) during islet culture. TGF-β signaling pathways are essential for vascular homeostasis but their importance for islet EC function is unclear. We have identified a population of multipotent mesenchymal stromal cells (MSCs) within islets and investigated how modulation of TGF-β signaling by these cells influences islet EC viability. Cultured islets exhibited reduced expression of EC markers (VEGFR2, VE-cadherin and CD31), which was associated with diminished but sustained expression of endoglin a marker of both ECs and MSCs. Double fluorescent labeling of islets in situ with the EC marker CD31 disclosed a population of CD31-negative cells which were positive for endoglin. In vitro coculture of microvascular ECs with endoglin-positive, CD31-negative islet MSCs reduced VEGFR2 protein expression, disrupted EC angiogenic behavior, and increased EC detachment. Medium conditioned by islet MSCs significantly decreased EC viability and increased EC caspase 3/7 activity. EC:MSC cocultures showed enhanced Smad2 phosphorylation consistent with altered ALK5 signaling. Pharmacological inhibition of ALK5 activity with SB431542 (SB) improved EC survival upon contact with MSCs, and SB-treated cultured islets retained EC marker expression and sensitivity to exogenous VEGF164 . Thus, endoglin-expressing islet MSCs influence EC ALK5 signaling in vitro, which decreases EC viability, and changes in ALK5 activity in whole cultured islets contribute to islet EC loss. Modifying TGF-β signaling may enable maintenance of islet ECs during islet isolation and thus improve islet graft revascularization post-transplantation. Copyright © 2013 AlphaMed Press.

  13. Experimental evidence for the origin of ductal-type adenocarcinoma from the islets of Langerhans.

    OpenAIRE

    Pour, P. M.; Weide, L.; Liu, G.; Kazakoff, K.; Scheetz, M.; Toshkov, I.; Ikematsu, Y.; Fienhold, M. A.; Sanger, W.

    1997-01-01

    To investigate the role of the islets of Langerhans in pancreatic carcinogenesis, freshly isolated islets from male Syrian hamsters were transplanted into the right submandibular glands of 50 female hamsters that were or were not pre-treated with streptozotocin. Thyroid gland fragments, cellulose powder, and immortal hamster pancreatic ductal cells were injected into the left submandibular gland of the same hamsters. All recipient hamsters were then treated with the potent pancreatic carcinog...

  14. Selective destruction of mouse islet beta cells by human T lymphocytes in a newly-established humanized type 1 diabetic model

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Yong, E-mail: yongzhao@uic.edu [Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612 (United States); Guo, Chengshan; Hwang, David; Lin, Brian; Dingeldein, Michael; Mihailescu, Dan; Sam, Susan; Sidhwani, Seema [Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612 (United States); Zhang, Yongkang [Department of Pharmacology, University of Illinois at Chicago, Chicago, IL 60612 (United States); Jain, Sumit [Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612 (United States); Skidgel, Randal A. [Department of Pharmacology, University of Illinois at Chicago, Chicago, IL 60612 (United States); Prabhakar, Bellur S. [Department of Immunology and Microbiology, University of Illinois at Chicago, Chicago, IL 60612 (United States); Mazzone, Theodore [Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612 (United States); Holterman, Mark J. [Department of Surgery, University of Illinois at Chicago, Chicago, IL 60612 (United States)

    2010-09-03

    Research highlights: {yields} Establish a human immune-mediated type 1 diabetic model in NOD-scid IL2r{gamma}{sup null} mice. {yields} Using the irradiated diabetic NOD mouse spleen mononuclear cells as trigger. {yields} The islet {beta} cells were selectively destroyed by infiltrated human T cells. {yields} The model can facilitate translational research to find a cure for type 1 diabetes. -- Abstract: Type 1 diabetes (T1D) is caused by a T cell-mediated autoimmune response that leads to the loss of insulin-producing {beta} cells. The optimal preclinical testing of promising therapies would be aided by a humanized immune-mediated T1D model. We develop this model in NOD-scid IL2r{gamma}{sup null} mice. The selective destruction of pancreatic islet {beta} cells was mediated by human T lymphocytes after an initial trigger was supplied by the injection of irradiated spleen mononuclear cells (SMC) from diabetic nonobese diabetic (NOD) mice. This resulted in severe insulitis, a marked loss of total {beta}-cell mass, and other related phenotypes of T1D. The migration of human T cells to pancreatic islets was controlled by the {beta} cell-produced highly conserved chemokine stromal cell-derived factor 1 (SDF-1) and its receptor C-X-C chemokine receptor (CXCR) 4, as demonstrated by in vivo blocking experiments using antibody to CXCR4. The specificity of humanized T cell-mediated immune responses against islet {beta} cells was generated by the local inflammatory microenvironment in pancreatic islets including human CD4{sup +} T cell infiltration and clonal expansion, and the mouse islet {beta}-cell-derived CD1d-mediated human iNKT activation. The selective destruction of mouse islet {beta} cells by a human T cell-mediated immune response in this humanized T1D model can mimic those observed in T1D patients. This model can provide a valuable tool for translational research into T1D.

  15. β-cell-specific IL-2 therapy increases islet Foxp3+Treg and suppresses type 1 diabetes in NOD mice.

    Science.gov (United States)

    Johnson, Mark C; Garland, Alaina L; Nicolson, Sarah C; Li, Chengwen; Samulski, R Jude; Wang, Bo; Tisch, Roland

    2013-11-01

    Interleukin-2 (IL-2) is a critical cytokine for the homeostasis and function of forkhead box p3-expressing regulatory T cells (Foxp3(+)Tregs). Dysregulation of the IL-2-IL-2 receptor axis is associated with aberrant Foxp3(+)Tregs and T cell-mediated autoimmune diseases such as type 1 diabetes. Treatment with recombinant IL-2 has been reported to enhance Foxp3(+)Tregs and suppress different models of autoimmunity. However, efficacy of IL-2 therapy is dependent on achieving sufficient levels of IL-2 to boost tissue-resident Foxp3(+)Tregs while avoiding the potential toxic effects of systemic IL-2. With this in mind, adeno-associated virus (AAV) vector gene delivery was used to localize IL-2 expression to the islets of NOD mice. Injection of a double-stranded AAV vector encoding IL-2 driven by a mouse insulin promoter (dsAAVmIP-IL2) increased Foxp3(+)Tregs in the islets but not the draining pancreatic lymph nodes. Islet Foxp3(+)Tregs in dsAAVmIP-IL2-treated NOD mice exhibited enhanced fitness marked by increased expression of Bcl-2, proliferation, and suppressor function. In contrast, ectopic IL-2 had no significant effect on conventional islet-infiltrating effector T cells. Notably, β-cell-specific IL-2 expression suppressed late preclinical type 1 diabetes in NOD mice. Collectively, these findings demonstrate that β-cell-specific IL-2 expands an islet-resident Foxp3(+)Tregs pool that effectively suppresses ongoing type 1 diabetes long term.

  16. Islet-like clusters derived from mesenchymal stem cells in Wharton's Jelly of the human umbilical cord for transplantation to control type 1 diabetes.

    Directory of Open Access Journals (Sweden)

    Kuo Ching Chao

    Full Text Available BACKGROUND: There is a widespread interest in developing renewable sources of islet-replacement tissue for type I diabetes mellitus. Human mesenchymal cells isolated from the Wharton's jelly of the umbilical cord (HUMSCs, which can be easily obtained and processed compared with embryonic and bone marrow stem cells, possess stem cell properties. HUMSCs may be a valuable source for the generation of islets. METHODOLOGY AND PRINCIPAL FINDINGS: HUMSCs were induced to transform into islet-like cell clusters in vitro through stepwise culturing in neuron-conditioned medium. To assess the functional stability of the islet-like cell clusters in vivo, these cell clusters were transplanted into the liver of streptozotocin-induced diabetic rats via laparotomy. Glucose tolerance was measured on week 12 after transplantation accompanied with immunohistochemistry and electron microscopy analysis. These islet-like cell clusters were shown to contain human C-peptide and release human insulin in response to physiological glucose levels. Real-time RT-PCR detected the expressions of insulin and other pancreatic beta-cell-related genes (Pdx1, Hlxb9, Nkx2.2, Nkx6.1, and Glut-2 in these islet-like cell clusters. The hyperglycemia and glucose intolerance in streptozotocin-induced diabetic rats was significantly alleviated after xenotransplantation of islet-like cell clusters, without the use of immunosuppressants. In addition to the existence of islet-like cell clusters in the liver, some special fused liver cells were also found, which characterized by human insulin and nuclei-positive staining and possessing secretory granules. CONCLUSIONS AND SIGNIFICANCE: In this study, we successfully differentiate HUMSCs into mature islet-like cell clusters, and these islet-like cell clusters possess insulin-producing ability in vitro and in vivo. HUMSCs in Wharton's Jelly of the umbilical cord seem to be the preferential source of stem cells to convert into insulin

  17. Dendritic Cells Promote Pancreatic Viability in Mice with Acute Pancreatitis

    Science.gov (United States)

    Bedrosian, Andrea S.; Nguyen, Andrew H.; Hackman, Michael; Connolly, Michael K.; Malhotra, Ashim; Ibrahim, Junaid; Cieza-Rubio, Napoleon E.; Henning, Justin R.; Barilla, Rocky; Rehman, Adeel; Pachter, H. Leon; Medina-Zea, Marco V.; Cohen, Steven M.; Frey, Alan B.; Acehan, Devrim; Miller, George

    2011-01-01

    Background & Aims Acute pancreatitis increases morbidity and mortality from organ necrosis by mechanisms that are incompletely understood. Dendritic cells (DCs) can promote or suppress inflammation, depending on their subtype and context. We investigated the roles of DC in development of acute pancreatitis. Methods Acute pancreatitis was induced in CD11c.DTR mice using caerulein or L-arginine; DCs were depleted by administration of diphtheria toxin. Survival was analyzed using Kaplan-Meier analysis. Results Numbers of MHC II+CD11c+DC increased 100-fold in pancreas of mice with acute pancreatitis, to account for nearly 15% of intra-pancreatic leukocytes. Intra-pancreatic DC acquired an immune phenotype in mice with acute pancreatitis; they expressed higher levels of MHC II and CD86 and increased production of interleukin-6, membrane cofactor protein (MCP)-1, and tumor necrosis factor (TNF)-α. However, rather than inducing an organ-destructive inflammatory process, DC were required for pancreatic viability; the exocrine pancreas died in mice that were depleted of DC and challenged with caerulein or L-arginine. All mice with pancreatitis that were depleted of DC died from acinar cell death within 4 days. Depletion of DC from mice with pancreatitis resulted in neutrophil infiltration and increased levels of systemic markers of inflammation. However, the organ necrosis associated with depletion of DC did not require infiltrating neutrophils, activation of NF-κB, or signaling by mitogen-activated protein kinase or TNF-α. Conclusions DC are required for pancreatic viability in mice with acute pancreatitis and might protect organs against cell stress. PMID:21801698

  18. TGF-β Signaling Regulates Pancreatic β-Cell Proliferation through Control of Cell Cycle Regulator p27 Expression

    International Nuclear Information System (INIS)

    Suzuki, Tomoyuki; Dai, Ping; Hatakeyama, Tomoya; Harada, Yoshinori; Tanaka, Hideo; Yoshimura, Norio; Takamatsu, Tetsuro

    2013-01-01

    Proliferation of pancreatic β-cells is an important mechanism underlying β-cell mass adaptation to metabolic demands. Increasing β-cell mass by regeneration may ameliorate or correct both type 1 and type 2 diabetes, which both result from inadequate production of insulin by β-cells of the pancreatic islet. Transforming growth factor β (TGF-β) signaling is essential for fetal development and growth of pancreatic islets. In this study, we exposed HIT-T15, a clonal pancreatic β-cell line, to TGF-β signaling. We found that inhibition of TGF-β signaling promotes proliferation of the cells significantly, while TGF-β signaling stimulation inhibits proliferation of the cells remarkably. We confirmed that this proliferative regulation by TGF-β signaling is due to the changed expression of the cell cycle regulator p27. Furthermore, we demonstrated that there is no observed effect on transcriptional activity of p27 by TGF-β signaling. Our data show that TGF-β signaling mediates the cell-cycle progression of pancreatic β-cells by regulating the nuclear localization of CDK inhibitor, p27. Inhibition of TGF-β signaling reduces the nuclear accumulation of p27, and as a result this inhibition promotes proliferation of β-cells

  19. A novel high-throughput assay for islet respiration reveals uncoupling of rodent and human islets.

    Directory of Open Access Journals (Sweden)

    Jakob D Wikstrom

    Full Text Available The pancreatic beta cell is unique in its response to nutrient by increased fuel oxidation. Recent studies have demonstrated that oxygen consumption rate (OCR may be a valuable predictor of islet quality and long term nutrient responsiveness. To date, high-throughput and user-friendly assays for islet respiration are lacking. The aim of this study was to develop such an assay and to examine bioenergetic efficiency of rodent and human islets.The XF24 respirometer platform was adapted to islets by the development of a 24-well plate specifically designed to confine islets. The islet plate generated data with low inter-well variability and enabled stable measurement of oxygen consumption for hours. The F1F0 ATP synthase blocker oligomycin was used to assess uncoupling while rotenone together with myxothiazol/antimycin was used to measure the level of non-mitochondrial respiration. The use of oligomycin in islets was validated by reversing its effect in the presence of the uncoupler FCCP. Respiratory leak averaged to 59% and 49% of basal OCR in islets from C57Bl6/J and FVB/N mice, respectively. In comparison, respiratory leak of INS-1 cells and C2C12 myotubes was measured to 38% and 23% respectively. Islets from a cohort of human donors showed a respiratory leak of 38%, significantly lower than mouse islets.The assay for islet respiration presented here provides a novel tool that can be used to study islet mitochondrial function in a relatively high-throughput manner. The data obtained in this study shows that rodent islets are less bioenergetically efficient than human islets as well as INS1 cells.

  20. Dissociation between insulin secretion and DNA synthesis in cultured pancreatic islets

    DEFF Research Database (Denmark)

    Nielsen, Jens Høiriis

    1985-01-01

    -Tdr incorporation. However, long-term exposure to IBMX did not result in increased DNA content of the islets. Inhibition of the DNA synthesis by 5 mM hydroxyurea resulted in a marked reduction in DNA content of the islets but no decrease in either insulin release or insulin content when expressed per ng DNA...

  1. Imatinib prevents beta cell death in vitro but does not improve islet transplantation outcome.

    Science.gov (United States)

    King, Aileen J F; Griffiths, Lisa A; Persaud, Shanta J; Jones, Peter M; Howell, Simon L; Welsh, Nils

    2016-05-01

    Introduction Improving islet transplantation outcome could not only bring benefits to individual patients but also widen the patient pool to which this life-changing treatment is available. Imatinib has previously been shown to protect beta cells from apoptosis in a variety of in vitro and in vivo models. The aim of this study was to investigate whether imatinib could be used to improve islet transplantation outcome. Methods Islets were isolated from C57Bl/6 mice and pre-cultured with imatinib prior to exposure to streptozotocin and cytokines in vitro. Cell viability and glucose-induced insulin secretion were measured. For transplantation experiments, islets were pre-cultured with imatinib for either 72 h or 24 h prior to transplantation into streptozotocin-diabetic C57Bl/6 mice. In one experimental series mice were also administered imatinib after islet transplantation. Results Imatinib partially protected islets from beta cell death in vitro. However, pre-culturing islets in imatinib or administering the drug to the mice in the days following islet transplantation did not improve blood glucose concentrations more than control-cultured islets. Conclusion Although imatinib protected against beta cell death from cytokines and streptozotocin in vitro, it did not significantly improve syngeneic islet transplantation outcome.

  2. Under a nonadherent state, bone marrow mesenchymal stem cells can be efficiently induced into functional islet-like cell clusters to normalize hyperglycemia in mice: a control study.

    Science.gov (United States)

    Zhang, Yihua; Dou, Zhongying

    2014-05-08

    Bone marrow mesenchymal stem cells (BMSCs) possess low immunogenicity and immunosuppression as an allograft, can differentiate into insulin-producing cells (IPCs) by in vitro induction, and may be a valuable cell source to regenerate pancreatic islets. However, the very low differentiation efficiency of BMSCs towards IPCs under adherent induction has thus far hindered the clinical exploitation of these cells. The aim of this study is to explore a new way to efficiently induce BMSCs into IPCs and lay the groundwork for their clinical exploitation. In comparison with adherent induction, BMSCs of human first-trimester abortus (hfBMSCs) under a nonadherent state were induced towards IPCs in noncoated plastic dishes using a three-stage induction procedure developed by the authors. Induction effects were evaluated by statistics of the cell clustering rate of induced cells, and ultrastructural observation, dithizone staining, quantitative polymerase chain reaction and immunofluorescence assay, insulin and c-peptide release under glucose stimulus of cell clusters, as well as transplantation test of the cell clusters in diabetic model mice. With (6.175 ± 0.263) × 105 cells in 508.5 ± 24.5 cell clusters, (3.303 ± 0.331) × 105 single cells and (9.478 ± 0.208) × 105 total cell count on average, 65.08 ± 2.98% hfBMSCs differentiated into pancreatic islet-like cell clusters after nonadherent induction. With (3.993 ± 0.344) × 105 cells in 332.3 ± 41.6 cell clusters, (5.437 ± 0.434) × 105 single cells and (9.430 ± 0.340) × 105 total cell count on average, 42.37 ± 3.70% hfBMSCs differentiated into pancreatic islet-like cell clusters after adherent induction (P produced human insulin in recipients. Our studies demonstrate that nonadherent induction can greatly promote BMSCs to form pancreatic islet-like cell clusters, thereby improving the differentiation efficiency of BMSCs towards IPCs.

  3. Small Islets Transplantation Superiority to Large Ones: Implications from Islet Microcirculation and Revascularization

    Directory of Open Access Journals (Sweden)

    Wenjuan Li

    2014-01-01

    Full Text Available Pancreatic islet transplantation is a promising therapy to regain glycemic control in diabetic patients. The selection of ideal grafts is the basis to guarantee short-term effectivity and longevity of the transplanted islets. Contradictory to the traditional notion, recent findings implied the superiority of small islets for better transplantation outcomes rather than the large and intact ones. However, the mechanisms remain to be elucidated. Recent evidences emphasized the major impact of microcirculation on islet β-cell mass and function. And potentials in islet graft revascularization are crucial for their survival and preserved function in the recipient. In this study, we verified the distinct histological phenotype and functionality of small islets versus large ones both in vitro and in vivo. With efforts to exploring the differences in microcirculation and revascularization of islet grafts, we further evaluated local expressions of angiotensin and vascular endothelial growth factor A (VEGF-A at different levels. Our findings reveal that, apart from the higher density of insulin-producing β-cells, small islets express less angiotensin and more angiotrophic VEGF-A. We therefore hypothesized a logical explanation of the small islet superiority for transplantation outcome from the aspects of facilitated microcirculation and revascularization intrinsically in small islets.

  4. Potential differentiation of islet-like cells from pregnant cow-derived placental stem cells

    Directory of Open Access Journals (Sweden)

    Shao-Yu Peng

    2017-06-01

    Conclusion: Altogether, islet-like cells have the potential to be differentiated from CPSCs without gene manipulation, and can be used in diabetic animal models in the future for preclinical and drug testing trial investigations.

  5. Current issues in allogeneic islet transplantation.

    Science.gov (United States)

    Chang, Charles A; Lawrence, Michael C; Naziruddin, Bashoo

    2017-10-01

    Transplantation of allogenic pancreatic islets is a minimally invasive treatment option to control severe hypoglycemia and dependence on exogenous insulin among type 1 diabetes (T1D) patients. This overview summarizes the current issues and progress in islet transplantation outcomes and research. Several clinical trials from North America and other countries have documented the safety and efficacy of clinical islet transplantation for T1D patients with impaired hypoglycemia awareness. A recently completed phase 3 clinical trial allows centres in the United States to apply for a Food and Drug Administration Biologics License for the procedure. Introduction of anti-inflammatory drugs along with T-cell depleting induction therapy has significantly improved long-term function of transplanted islets. Research into islet biomarkers, immunosuppression, extrahepatic transplant sites and potential alternative beta cell sources is driving further progress. Allogeneic islet transplantation has vastly improved over the past two decades. Success in restoration of glycemic control and hypoglycemic awareness after islet transplantation has been further highlighted by clinical trials. However, lack of effective strategies to maintain long-term islet function and insufficient sources of donor tissue still impose limitations to the widespread use of islet transplantation. In the United States, wide adoption of this technology still awaits regulatory approval and, importantly, a financial mechanism to support the use of this technology.

  6. Gadolinium- and manganite-based contrast agents with fluorescent probes for both magnetic resonance and fluorescence imaging of pancreatic islets: a comparative study

    Czech Academy of Sciences Publication Activity Database

    Berková, Z.; Jirák, D.; Zacharovová, K.; Lukeš, I.; Kotková, Z.; Kotek, J.; Kačenka, M.; Kaman, Ondřej; Řehoř, I.; Hájek, M.; Saudek, F.

    2013-01-01

    Roč. 8, č. 4 (2013), s. 614-621 ISSN 1860-7179 Institutional support: RVO:68378271 Keywords : contrast agents * gadolinium * magnetic resonance imaging * manganite * pancreatic islet s Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.046, year: 2013

  7. Decreased insulin secretory response of pancreatic islets during culture in the presence of low glucose is associated with diminished 45Ca2+ net uptake, NADPH/NADP+ and GSH/GSSG ratios

    International Nuclear Information System (INIS)

    Verspohl, E.J.; Kaiser, P.; Wahl, M.; Ammon, H.P.T.

    1988-01-01

    In isolated rat pancreatic islets maintained at a physiologic glucose concentration (5.6 mM) the effect of glucose on parameters which are known to be involved in the insulin secretion coupling such as NADPH, reduced glutathione (GSH), 86 Rb + efflux, and 45 Ca ++ net uptake were investigated. The insulinotropic effect of 16.7 mM glucose was decreased with the period of culturing during the first 14 days being significant after 2 days though in control experiments both protein content and ATP levels per islet were not affected and insulin content was only slightly decreased. Both NADPH and GSH decreased with time of culture. 86 Rb + efflux which is decreased by enhancing the glucose concentration from 3 to 5.6 mM in freshly isolated islets was not affected by culturing whatsoever, even not after 14 days of culture when there was not longer any insulin responsiveness to glucose. The 45 Ca ++ net uptake was decreased during culturing. The data indicate (1) that the diminished glucose-stimulated release of insulin during culturing is not due to cell loss or simple energy disturbances, (2) that more likely it is the result of a diminished 45 Ca ++ net uptake as a consequence of the inability of islet cells to maintain proper NADPH and GSH levels, and (3) that potassium ( 86 Rb + ) efflux may not be related to changes of NADPH and GSH

  8. In vitro reprogramming of rat bmMSCs into pancreatic endocrine-like cells.

    Science.gov (United States)

    Li, Hong-Tu; Jiang, Fang-Xu; Shi, Ping; Zhang, Tao; Liu, Xiao-Yu; Lin, Xue-Wen; San, Zhong-Yan; Pang, Xi-Ning

    2017-02-01

    Islet transplantation provides curative treatments to patients with type 1 diabetes, but donor shortage restricts the broad use of this therapy. Thus, generation of alternative transplantable cell sources is intensively investigated worldwide. We previously showed that bone marrow-derived mesenchymal stem cells (bmMSCs) can be reprogrammed to pancreatic-like cells through simultaneously forced suppression of Rest/Nrsf (repressor element-1 silencing transcription factor/neuronal restrictive silencing factor) and Shh (sonic hedgehog) and activation of Pdx1 (pancreas and duodenal transcription factor 1). We here aimed to reprogram bmMSCs further along the developmental pathway towards the islet lineages by improving our previous strategy and by overexpression of Ngn3 (neurogenin 3) and NeuroD1 (neurogenic differentiation 1), critical regulators of the development of endocrine pancreas. We showed that compared to the previous protocol, the overexpression of only Pdx1 and Ngn3 reprogrammed bmMSCs into cells with more characteristics of islet endocrine lineages verified with bioinformatic analyses of our RNA-Seq datasets. These analyses indicated 2325 differentially expressed genes including those involved in the pancreas and islet development. We validated with qRT-PCR analysis selective genes identified from the RNA-Seq datasets. Thus, we reprogrammed bmMSCs into islet endocrine-like cells and advanced the endeavor to generate surrogate functional insulin-secreting cells.

  9. Xylitol improves pancreatic islets morphology to ameliorate type 2 diabetes in rats: a dose response study.

    Science.gov (United States)

    Rahman, Md Atiar; Islam, Md Shahdiul

    2014-07-01

    Xylitol has been reported as a potential antidiabetic sweetener in a number of recent studies; however, the most effective dietary dose and organ-specific effects are still unclear. Six-week-old male Sprague-Dawley rats were randomly divided into 5 groups: normal control (NC), diabetic control (DBC), diabetic xylitol 2.5% (DXL2.5), diabetic xylitol 5.0% (DXL5), and diabetic xylitol 10.0% (DXL10). Diabetes was induced only in the animals in DBC and DXL groups and considered diabetic when their nonfasting blood glucose level was >300 mg/dL. The DXL groups were fed with 2.5%, 5.0%, and 10% xylitol solution, whereas the NC and DBC groups were supplied with normal drinking water. After 4-wk intervention, body weight, food and fluid intake, blood glucose, serum fructosamine, liver glycogen, serum alanine transaminase, aspartate transaminase, lactate dehydrogenase, creatine kinase, uric acid, creatinine, and most serum lipids were significantly decreased, and serum insulin concentration, glucose tolerance ability, and pancreatic islets morphology were significantly improved in the DXL10 group compared to the DBC group. The data of this study suggest that 10% xylitol has the better antidiabetic effects compared to 2.5% and 5.0% and it can be used as an excellent antidiabetic sweetener and food supplement in antidiabetic foods. Xylitol is widely used as a potential anticariogenic and sweetening agent in a number of oral care and food products when many of its health benefits are still unknown. Due to its similar sweetening power but lower calorific value (2.5 compared with 4 kcal) and lower glycemic index (13 compared with 65) compared to sucrose, recently it has been widely used as a sugar substitute particularly by overweight, obese, and diabetic patients in order to reduce their calorie intake from sucrose. However, the potential antidiabetic effects of xylitol have been discovered recently. The results of this study confirmed the effective dietary dose of xylitol for

  10. Effect of interleukin-1 on the biosynthesis of proinsulin and insulin in isolated rat pancreatic islets

    DEFF Research Database (Denmark)

    Hansen, Birgit Sehested; Linde, S; Spinas, G A

    1988-01-01

    Insulin dependent diabetes mellitus (IDDM) is often preceded or associated with lymphocytic infiltration in the islets of Langerhans (insulitis). We recently demonstrated that interleukin-1 (IL-1) produced by activated macrophages exerts a bimodal effect on insulin release and biosynthesis...... in isolated rat islets. In the present study we have further analysed the effect of recombinant human interleukin-1 beta (rIL-1) on the biosynthesis and conversion of proinsulin 1 and 2 in rat islets. By RP-HPLC-analysis of islets labelled with [3H]leucine we found that exposure to 6 ng/ml of IL-1 for 24 h.......1 to 3.4 +/- 0.4, respectively. Pulse-chase experiments with [3H]leucine and [35S]methionine indicated a more marked reduction in the conversion rate of proinsulin-2 compared to that of proinsulin-1. In conclusion these experiments demonstrate that IL-1 inhibits insulin biosynthesis by preferential...

  11. Molecular Imaging: A Promising Tool to Monitor Islet Transplantation

    Directory of Open Access Journals (Sweden)

    Ping Wang

    2011-01-01

    Full Text Available Replacement of insulin production by pancreatic islet transplantation has great potential as a therapy for type 1 diabetes mellitus. At present, the lack of an effective approach to islet grafts assessment limits the success of this treatment. The development of molecular imaging techniques has the potential to fulfill the goal of real-time noninvasive monitoring of the functional status and viability of the islet grafts. We review the application of a variety of imaging modalities for detecting endogenous and transplanted beta-cell mass. The review also explores the various molecular imaging strategies for assessing islet delivery, the metabolic effects on the islet grafts as well as detection of immunorejection. Here, we highlight the use of combined imaging and therapeutic interventions in islet transplantation and the in vivo monitoring of stem cells differentiation into insulin-producing cells.

  12. Should the negativity for islet cell autoantibodies be used in a prescreening for genetic testing in maturity-onset diabetes of the young? The case of autoimmunity-associated destruction of pancreatic β-cells in a family of HNF1A-MODY subjects.

    Science.gov (United States)

    Urbanová, Jana; Rypáčková, Blanka; Kučera, Petr; Anděl, Michal; Heneberg, Petr

    2013-01-01

    It was recently suggested that routine islet cell autoantibody testing should be performed to discriminate maturity-onset diabetes of the young (MODY) from type 1 diabetes mellitus (T1DM). This is the first report ever to describe the familial manifestation of T1DM autoimmunity in nonobese HNF1A-MODY subjects and the presence of islet antigen-2 (IA-2) antibodies in MODY subjects. Three nonobese subjects in an age range of 14-35 years were diagnosed with HNF1A-MODY (p. Arg159Gln mutation). All the tested subjects had detectable (but varying) levels of islet cell autoantibodies (i.e., antibodies against glutamate decarboxylase or IA-2) in the absence of other T1DM characteristics. They displayed long-term expression of intermediate fasting C-peptide levels, ketoacidosis was absent even in periods of spontaneous insulin withdrawal, and full dependence on externally administered insulin was not detected in any of them although better glycemic control was achieved when insulin was supplemented. The course of the disease was similar to that of the autoantibody-negative HNF1A-MODY subjects. The case questions the selectivity of autoantibodies as a marker of T1DM or late-onset autoimmune diabetes of adulthood (LADA) over MODY and challenges the use of autoantibodies as a universal negative marker of MODY in an effort to decrease the cost of health care, as it may eventually lead to the wrong diagnosis and thus to the incorrect treatment. Further research should involve examination of the autoantibody titers and prevalence in large and geographically diverse cohorts of MODY subjects selected for genetic testing (regardless of their autoantibody titers) as well as determination of the islet cell autoantibody kinetics in the course of MODY onset and progression. Copyright © 2013 S. Karger AG, Basel.

  13. Islet graft survival and function: concomitant culture and transplantation with vascular endothelial cells in diabetic rats.

    Science.gov (United States)

    Pan, Xiaoming; Xue, Wujun; Li, Yang; Feng, Xinshun; Tian, Xiaohui; Ding, Chenguang

    2011-12-15

    Human islet transplantation is a great potential therapy for type I diabetes. To investigate islet graft survival and function, we recently showed the improved effects after co-culture and co-transplantation with vascular endothelial cells (ECs) in diabetic rats. ECs were isolated, and the viability of isolated islets was assessed in two groups (standard culture group and co-culture group with ECs). Then streptozotocin-induced diabetic rats were divided into four groups before islet transplantation as follows: group A with infusion of islet grafts; group B with combined vascular ECs and islet grafts; groups C and D as controls with single ECs infusion and phosphate-buffered saline injection, respectively. Blood glucose and insulin concentrations were measured daily. Expression of vascular endothelial growth factor was investigated by immunohistochemical staining. The mean microvascular density was also calculated. More than 90% of acridine orange-propidium iodide staining positive islets demonstrated normal morphology while co-cultured with ECs for 7 days. Compared with standard control, insulin release assays showed a significantly higher simulation index in co-culture group except for the first day (Ptransplantation, there was a significant difference in concentrations of blood glucose and insulin among these groups after 3 days (Pislet group (P=0.04). Co-culture with ECs in vitro could improve the survival and function of isolated rat islet, and co-transplantation of islets with ECs could effectively prolong the islet graft survival in diabetic rats.

  14. Chaperones ameliorate beta cell dysfunction associated with human islet amyloid polypeptide overexpression.

    Directory of Open Access Journals (Sweden)

    Lisa Cadavez

    Full Text Available In type 2 diabetes, beta-cell dysfunction is thought to be due to several causes, one being the formation of toxic protein aggregates called islet amyloid, formed by accumulations of misfolded human islet amyloid polypeptide (hIAPP. The process of hIAPP misfolding and aggregation is one of the factors that may activate the unfolded protein response (UPR, perturbing endoplasmic reticulum (ER homeostasis. Molecular chaperones have been described to be important in regulating ER response to ER stress. In the present work, we evaluate the role of chaperones in a stressed cellular model of hIAPP overexpression. A rat pancreatic beta-cell line expressing hIAPP exposed to thapsigargin or treated with high glucose and palmitic acid, both of which are known ER stress inducers, showed an increase in ER stress genes when compared to INS1E cells expressing rat IAPP or INS1E control cells. Treatment with molecular chaperone glucose-regulated protein 78 kDa (GRP78, also known as BiP or protein disulfite isomerase (PDI, and chemical chaperones taurine-conjugated ursodeoxycholic acid (TUDCA or 4-phenylbutyrate (PBA, alleviated ER stress and increased insulin secretion in hIAPP-expressing cells. Our results suggest that the overexpression of hIAPP induces a stronger response of ER stress markers. Moreover, endogenous and chemical chaperones are able to ameliorate induced ER stress and increase insulin secretion, suggesting that improving chaperone capacity can play an important role in improving beta-cell function in type 2 diabetes.

  15. Islet cell transplant: Update on current clinical trials

    Science.gov (United States)

    Schuetz, Christian; Markmann, James F.

    2016-01-01

    In the last 15 years clinical islet transplantation has made the leap from experimental procedure to standard of care for a highly selective group of patients. Due to a risk-benefit calculation involving the required systemic immunosuppression the procedure is only considered in patients with type 1 diabetes, complicated by severe hypoglycemia or end stage renal disease. In this review we summarize current outcomes of the procedure and take a look at ongoing and future improvements and refinements of beta cell therapy. PMID:28451515

  16. OctreoScan 111 for imaging of a somatostatin receptor-positive islet cell tumor in rat

    International Nuclear Information System (INIS)

    Bruns, C.; Stolz, B.; Albert, R.; Marbach, P.; Pless, J.

    1993-01-01

    We report here the in vitro characterization of SDZ 215-811 and the in vivo imaging of a islet cell tumor gown in rats using [ 111 In]SDZ 215-811. In vitro autoradiographies revelaed a high density of SRIF receptors on the pancreatic tumor tissue. As early as 5 min after intravenous injection of [ 111 In]SDZ 215-811 into tumour-bearing rats, the tumors were clearly localized by gamma-camera scintigraphy. Even 24 h post injection, the islet cell tumor was still detectable. The radioligand was mainly cleared from the circulation via the Kidneys, with a rapid α-phase (t 1/2 =5.6 min) and a slow elimination phase (t 1/2 =7.3 h). Biodistribution studies revealed a relatively high accumulation of radioactivity in the kidneys, but low uptake into the liver and the intestine. High uptake of [ 111 In]SDZ 215-811 was observed for the tumor tissue (0.92±0.07% ID/g; 1 h post injection). Interestingly, a tumor load of 0.14±0.01% ID/g was still measured after 24 h. The tumor/blood ratio was 4.93 after 24 h, indicating specific accumulation of radioactivity in the islet cell tumour. [ 111 In]SDZ 215-811 appears to be sensitive and specific ligand for SRIF receptorpositive tumors and offers an easy procedure for scintigraphic imaging of such tumors in man. (orig.)

  17. Long-term outcomes of clinical transplantation of pancreatic islets with uncontrolled donors after cardiac death: a multicenter experience in Japan.

    Science.gov (United States)

    Anazawa, T; Saito, T; Goto, M; Kenmochi, T; Uemoto, S; Itoh, T; Yasunami, Y; Kenjo, A; Kimura, T; Ise, K; Tsuchiya, T; Gotoh, M

    2014-01-01

    Pancreatic islet transplantation has emerged as an effective treatment for type 1 diabetes mellitus, but its use is limited due to an insufficient supply of cadaveric pancreata. In Japan, uncontrolled donors after cardiac death (DCD) are not deemed to be suitable for whole-organ pancreatic transplantation, and can provide a source of pancreas for islet transplantation. However, the long-term outcomes and utility of uncontrolled DCD in the clinical setting remain controversial. Here, we summarize the long-term outcomes of islet transplantation employing uncontrolled DCD as reported to the Japan Islet Transplantation Registry. Sixty-four isolations and 34 transplantations of pancreatic islets were conducted in 18 subjects with type 1 diabetes mellitus under the cover of immunosuppression with basiliximab, sirolimus, and tacrolimus. All donors were uncontrolled DCD at the time of harvesting. The mean follow-up time was 76 months. Of the 18 recipients, 8, 4, and 6 recipients received 1, 2, and 3 islet infusions, respectively. Overall graft survivals (defined as a C-peptide level ≥0.3 ng/mL) were 72.2%, 44.4%, and 22.2% at 1, 2, and 5 years, respectively, whereas the corresponding graft survivals after multiple infusions were 90.0%, 70.0%, and 30.0%, respectively. Three of these recipients achieved insulin independence in 14, 79, and 215 days. HbA1c levels and the requirement of exogenous insulin were improved before loss of graft function. All recipients became free of severe hypoglycemia unawareness, however, at least 5 of 14 patients who had graft failure experienced recurrence of severe hypoglycemia after the loss of graft function. Islet transplantation from DCD can relieve glucose instability and problems with hypoglycemia when the graft is functioning. However, islets from uncontrolled DCD may be associated with reduced long-term graft survival. Further improvements in the clinical outcome by modification of islet isolation/transplantation protocols are

  18. The Placental Secretome: Identifying Potential Cross-Talk Between Placenta and Islet β-Cells

    Directory of Open Access Journals (Sweden)

    Robert Drynda

    2018-02-01

    Full Text Available Background/Aims: Insulin-secreting islet β-cells adapt to the insulin resistance associated with pregnancy by increasing functional β-cell mass, but the placental signals involved in this process are not well defined. In the current study, we analysed expression of G-protein coupled receptor (GPCR mRNAs in mouse islets and islet GPCR ligand mRNAs in placenta during pregnancy to generate an atlas of potential interactions between the placenta and β-cells to inform future functional studies of islet adaptive responses to pregnancy. Methods: Quantative RT-PCR arrays were used to measure mRNA expression levels of: (i 342 GPCRs in islets from non-pregnant mice, and in islets isolated from mice on gestational days 12 and 18; (ii 126 islet GPCR ligands in mouse placenta at gestational days 12 and 18. Results: At gestational day 12, a time of rapid expansion of the β-cell mass, 189 islet GPCR mRNAs were quantifiable, while 79 of the 126 known islet GPCR ligand mRNAs were detectable in placental extracts. Approximately half of the quantifiable placental GPCR ligand genes were of unknown function in β-cells. The expression of some islet GPCR and placental ligand mRNAs varied during pregnancy, with altered expression of both GPCR and ligand mRNAs by gestational day 18. Conclusion: The current study has revealed numerous potential routes for interaction between the placenta and islets, and offers an atlas to inform further functional studies of their roles in adaptive responses to pregnancy, and in the regulation of the β-cell mass.

  19. Assessment of DNA synthesis in Islet-1{sup +} cells in the adult murine heart

    Energy Technology Data Exchange (ETDEWEB)

    Weinberger, Florian, E-mail: f.weinberger@uke.de; Mehrkens, Dennis, E-mail: dennis.mehrkens@uk-koeln.de; Starbatty, Jutta, E-mail: starbatty@uke.uni-hamburg.de; Nicol, Philipp, E-mail: Philipp.Nicol@gmx.de; Eschenhagen, Thomas, E-mail: t.eschenhagen@uke.de

    2015-01-02

    Highlights: • Islet-1 was expressed in the adult heart. • Islet-1-positive cells did not proliferate in the adult heart. • Sinoatrial node cells did not proliferate in the adult heart. - Abstract: Rationale: Islet-1 positive (Islet-1{sup +}) cardiac progenitor cells give rise to the right ventricle, atria and outflow tract during murine cardiac development. In the adult heart Islet-1 expression is limited to parasympathetic neurons, few cardiomyocytes, smooth muscle cells, within the proximal aorta and pulmonary artery and sinoatrial node cells. Its role in these cells is unknown. Here we tested the hypothesis that Islet-1{sup +} cells retain proliferative activity and may therefore play a role in regenerating specialized regions in the heart. Methods and results: DNA synthesis was analyzed by the incorporation of tritiated thymidine ({sup 3}H-thymidine) in Isl-1-nLacZ mice, a transgenic model with an insertion of a nuclear beta-galactosidase in the Islet-1 locus. Mice received daily injections of {sup 3}H-thymidine for 5 days. DNA synthesis was visualized throughout the heart by dipping autoradiography of cryosections. Colocalization of an nLacZ-signal and silver grains would indicate DNA synthesis in Islet-1{sup +} cells. Whereas Islet{sup −} non-myocyte nuclei were regularly marked by accumulation of silver grains, colocalization with nLacZ-signals was not detected in >25,000 cells analyzed. Conclusions: Islet-1{sup +} cells are quiescent in the adult heart, suggesting that, under normal conditions, even pacemaking cells do not proliferate at higher rates than normal cardiac myocytes.

  20. Assessment of DNA synthesis in Islet-1+ cells in the adult murine heart

    International Nuclear Information System (INIS)

    Weinberger, Florian; Mehrkens, Dennis; Starbatty, Jutta; Nicol, Philipp; Eschenhagen, Thomas

    2015-01-01

    Highlights: • Islet-1 was expressed in the adult heart. • Islet-1-positive cells did not proliferate in the adult heart. • Sinoatrial node cells did not proliferate in the adult heart. - Abstract: Rationale: Islet-1 positive (Islet-1 + ) cardiac progenitor cells give rise to the right ventricle, atria and outflow tract during murine cardiac development. In the adult heart Islet-1 expression is limited to parasympathetic neurons, few cardiomyocytes, smooth muscle cells, within the proximal aorta and pulmonary artery and sinoatrial node cells. Its role in these cells is unknown. Here we tested the hypothesis that Islet-1 + cells retain proliferative activity and may therefore play a role in regenerating specialized regions in the heart. Methods and results: DNA synthesis was analyzed by the incorporation of tritiated thymidine ( 3 H-thymidine) in Isl-1-nLacZ mice, a transgenic model with an insertion of a nuclear beta-galactosidase in the Islet-1 locus. Mice received daily injections of 3 H-thymidine for 5 days. DNA synthesis was visualized throughout the heart by dipping autoradiography of cryosections. Colocalization of an nLacZ-signal and silver grains would indicate DNA synthesis in Islet-1 + cells. Whereas Islet − non-myocyte nuclei were regularly marked by accumulation of silver grains, colocalization with nLacZ-signals was not detected in >25,000 cells analyzed. Conclusions: Islet-1 + cells are quiescent in the adult heart, suggesting that, under normal conditions, even pacemaking cells do not proliferate at higher rates than normal cardiac myocytes

  1. A Practical Guide to Rodent Islet Isolation and Assessment

    Directory of Open Access Journals (Sweden)

    Carter Jeffrey D

    2009-12-01

    Full Text Available Abstract Pancreatic islets of Langerhans secrete hormones that are vital to the regulation of blood glucose and are, therefore, a key focus of diabetes research. Purifying viable and functional islets from the pancreas for study is an intricate process. This review highlights the key elements involved with mouse and rat islet isolation, including choices of collagenase, the collagenase digestion process, purification of islets using a density gradient, and islet culture conditions. In addition, this paper reviews commonly used techniques for assessing islet viability and function, including visual assessment, fluorescent markers of cell death, glucose-stimulated insulin secretion, and intracellular calcium measurements. A detailed protocol is also included that describes a common method for rodent islet isolation that our laboratory uses to obtain viable and functional mouse islets for in vitro study of islet function, beta-cell physiology, and in vivo rodent islet transplantation. The purpose of this review is to serve as a resource and foundation for successfully procuring and purifying high-quality islets for research purposes.

  2. Collagen esterification enhances the function and survival of pancreatic β cells in 2D and 3D culture systems

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Jae Hyung [Regenerative Medicine Research Center, Dalim Tissen Co., LTD., 383-93, Yonnam-Dong, Mapo-gu, Seoul (Korea, Republic of); Kim, Yang Hee [Regenerative Medicine Research Center, Dalim Tissen Co., LTD., 383-93, Yonnam-Dong, Mapo-gu, Seoul (Korea, Republic of); Asan Institute for Life Science, 388-1 Pungnap-2 Dong, Songpa-gu, Seoul (Korea, Republic of); Jeong, Seong Hee; Lee, Song [Asan Institute for Life Science, 388-1 Pungnap-2 Dong, Songpa-gu, Seoul (Korea, Republic of); Park, Si-Nae [Regenerative Medicine Research Center, Dalim Tissen Co., LTD., 383-93, Yonnam-Dong, Mapo-gu, Seoul (Korea, Republic of); Shim, In Kyong, E-mail: shimiink@gmail.com [Asan Institute for Life Science, 388-1 Pungnap-2 Dong, Songpa-gu, Seoul (Korea, Republic of); Kim, Song Cheol, E-mail: drksc@amc.seoul.kr [Asan Institute for Life Science, 388-1 Pungnap-2 Dong, Songpa-gu, Seoul (Korea, Republic of); Department of Surgery, University of Ulsan College of Medicine & Asan Medical Center, 388-1 Pungnap-2 Dong, Songpa-gu, Seoul (Korea, Republic of)

    2015-08-07

    Collagen, one of the most important components of the extracellular matrix (ECM), may play a role in the survival of pancreatic islet cells. In addition, chemical modifications that change the collagen charge profile to a net positive charge by esterification have been shown to increase the adhesion and proliferation of various cell types. The purpose of this study was to characterize and compare the effects of native collagen (NC) and esterified collagen (EC) on β cell function and survival. After isolation by the collagenase digestion technique, rat islets were cultured with NC and EC in 2 dimensional (2D) and 3 dimensional (3D) environments for a long-term duration in vitro. The cells were assessed for islet adhesion, morphology, viability, glucose-induced insulin secretion, and mRNA expression of glucose metabolism-related genes, and visualized by scanning electron microscopy (SEM). Islet cells attached tightly in the NC group, but islet cell viability was similar in both the NC and EC groups. Glucose-stimulated insulin secretion was higher in the EC group than in the NC group in both 2D and 3D culture. Furthermore, the mRNA expression levels of glucokinase in the EC group were higher than those in the NC group and were associated with glucose metabolism and insulin secretion. Finally, SEM observation confirmed that islets had more intact component cells on EC sponges than on NC sponges. These results indicate that modification of collagen may offer opportunities to improve function and viability of islet cells. - Highlights: • We changed the collagen charge profile to a net positive charge by esterification. • Islets cultured on esterified collagen improved survival in both 2D and 3D culture. • Islets cultured on esterified collagen enhanced glucose-stimulated insulin release. • High levels of glucokinase mRNA may be associated with increased insulin release.

  3. Collagen esterification enhances the function and survival of pancreatic β cells in 2D and 3D culture systems

    International Nuclear Information System (INIS)

    Ko, Jae Hyung; Kim, Yang Hee; Jeong, Seong Hee; Lee, Song; Park, Si-Nae; Shim, In Kyong; Kim, Song Cheol

    2015-01-01

    Collagen, one of the most important components of the extracellular matrix (ECM), may play a role in the survival of pancreatic islet cells. In addition, chemical modifications that change the collagen charge profile to a net positive charge by esterification have been shown to increase the adhesion and proliferation of various cell types. The purpose of this study was to characterize and compare the effects of native collagen (NC) and esterified collagen (EC) on β cell function and survival. After isolation by the collagenase digestion technique, rat islets were cultured with NC and EC in 2 dimensional (2D) and 3 dimensional (3D) environments for a long-term duration in vitro. The cells were assessed for islet adhesion, morphology, viability, glucose-induced insulin secretion, and mRNA expression of glucose metabolism-related genes, and visualized by scanning electron microscopy (SEM). Islet cells attached tightly in the NC group, but islet cell viability was similar in both the NC and EC groups. Glucose-stimulated insulin secretion was higher in the EC group than in the NC group in both 2D and 3D culture. Furthermore, the mRNA expression levels of glucokinase in the EC group were higher than those in the NC group and were associated with glucose metabolism and insulin secretion. Finally, SEM observation confirmed that islets had more intact component cells on EC sponges than on NC sponges. These results indicate that modification of collagen may offer opportunities to improve function and viability of islet cells. - Highlights: • We changed the collagen charge profile to a net positive charge by esterification. • Islets cultured on esterified collagen improved survival in both 2D and 3D culture. • Islets cultured on esterified collagen enhanced glucose-stimulated insulin release. • High levels of glucokinase mRNA may be associated with increased insulin release

  4. Mesenchymal stromal cells improve human islet function through released products and extracellular matrix.

    Science.gov (United States)

    Arzouni, Ahmed A; Vargas-Seymour, Andreia; Rackham, Chloe L; Dhadda, Paramjeet; Huang, Guo-Cai; Choudhary, Pratik; Nardi, Nance; King, Aileen J F; Jones, Peter M

    2017-12-01

    The aims of the present study were (i) to determine whether the reported beneficial effects of mesenchymal stromal cells (MSCs) on mouse islet function extend to clinically relevant human tissues (islets and MSCs), enabling translation into improved protocols for clinical human islet transplantation; and (ii) to identify possible mechanisms through which human MSCs influence human islet function. Human islets were co-cultured with human adipose tissue-derived MSCs (hASCs) or pre-treated with its products - extracellular matrix (ECM) and annexin A1 (ANXA1). Mouse islets were pre-treated with mouse MSC-derived ECM. Islet insulin secretory function was assessed in vitro by radioimmunoassay. Quantitative RT-PCR was used to screen human adipMSCs for potential ligands of human islet G-protein-coupled receptors. We show that co-culture with hASCs improves human islet secretory function in vitro , as measured by glucose-stimulated insulin secretion, confirming previous reports using rodent tissues. Furthermore, we demonstrate that these beneficial effects on islet function can be partly attributed to the MSC-derived products ECM and ANXA1. Our results suggest that hASCs have the potential to improve the quality of human islets isolated for transplantation therapy of Type 1 diabetes. Furthermore, it may be possible to achieve improvements in human islet quality in a cell-free culture system by using the MSC-derived products ANXA1 and ECM. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

  5. Drp1 guarding of the mitochondrial network is important for glucose-stimulated insulin secretion in pancreatic beta cells

    Energy Technology Data Exchange (ETDEWEB)

    Reinhardt, Florian; Schultz, Julia; Waterstradt, Rica; Baltrusch, Simone, E-mail: simone.baltrusch@med.uni-rostock.de

    2016-06-10

    Mitochondria form a tubular network in mammalian cells, and the mitochondrial life cycle is determined by fission, fusion and autophagy. Dynamin-related protein 1 (Drp1) has a pivotal role in these processes because it alone is able to constrict mitochondria. However, the regulation and function of Drp1 have been shown to vary between cell types. Mitochondrial morphology affects mitochondrial metabolism and function. In pancreatic beta cells mitochondrial metabolism is a key component of the glucose-induced cascade of insulin secretion. The goal of the present study was to investigate the action of Drp1 in pancreatic beta cells. For this purpose Drp1 was down-regulated by means of shDrp1 in insulin-secreting INS1 cells and mouse pancreatic islets. In INS1 cells reduced Drp1 expression resulted in diminished expression of proteins regulating mitochondrial fusion, namely mitofusin 1 and 2, and optic atrophy protein 1. Diminished mitochondrial dynamics can therefore be assumed. After down-regulation of Drp1 in INS1 cells and spread mouse islets the initially homogenous mitochondrial network characterised by a moderate level of interconnections shifted towards high heterogeneity with elongated, clustered and looped mitochondria. These morphological changes were found to correlate directly with functional alterations. Mitochondrial membrane potential and ATP generation were significantly reduced in INS1 cells after Drp1down-regulation. Finally, a significant loss of glucose-stimulated insulin secretion was demonstrated in INS1 cells and mouse pancreatic islets. In conclusion, Drp1 expression is important in pancreatic beta cells to maintain the regulation of insulin secretion. -- Highlights: •Down-regulation of Drp1 in INS1 cells reduces mitochondrial fusion protein expression. •Mitochondrial membrane potential in INS1 cells is diminished after Drp1 down-regulation. •Mitochondria become elongated after down-regulation of Drp1 in beta cells. •Down-regulation of

  6. Quantitative measurement of zinc secretion from pancreatic islets with high temporal resolution using droplet-based microfluidics.

    Science.gov (United States)

    Easley, Christopher J; Rocheleau, Jonathan V; Head, W Steven; Piston, David W

    2009-11-01

    We assayed glucose-stimulated insulin secretion (GSIS) from live, murine islets of Langerhans in microfluidic devices by the downstream formation of aqueous droplets. Zinc ions, which are cosecreted with insulin from beta-cells, were quantitatively measured from single islets with high temporal resolution using a fluorescent indicator, FluoZin-3. Real-time storage of secretions into droplets (volume of 0.470 +/- 0.009 nL) effectively preserves the temporal chemical information, allowing reconstruction of the secretory time record. The use of passive flow control within the device removes the need for syringe pumps, requiring only a single hand-held syringe. Under stimulatory glucose levels (11 mM), bursts of zinc as high as approximately 800 fg islet(-1) min(-1) were measured. Treatment with diazoxide effectively blocked zinc secretion, as expected. High temporal resolution reveals two major classes of oscillations in secreted zinc, with predominate periods at approximately 20-40 s and approximately 5-10 min. The more rapid oscillation periods match closely with those of intraislet calcium oscillations, while the slower oscillations are consistent with insulin pulses typically measured in bulk islet experiments or in the bloodstream. This droplet sampling technique should be widely applicable to time-resolved cellular secretion measurements, either in real-time or for postprocessing.

  7. LIGHT/TNFSF14 is increased in patients with type 2 diabetes mellitus and promotes islet cell dysfunction and endothelial cell inflammation in vitro.

    Science.gov (United States)

    Halvorsen, Bente; Santilli, Francesca; Scholz, Hanne; Sahraoui, Afaf; Gulseth, Hanne L; Wium, Cecilie; Lattanzio, Stefano; Formoso, Gloria; Di Fulvio, Patrizia; Otterdal, Kari; Retterstøl, Kjetil; Holven, Kirsten B; Gregersen, Ida; Stavik, Benedicte; Bjerkeli, Vigdis; Michelsen, Annika E; Ueland, Thor; Liani, Rossella; Davi, Giovanni; Aukrust, Pål

    2016-10-01

    Activation of inflammatory pathways is involved in the pathogenesis of type 2 diabetes mellitus. On the basis of its role in vascular inflammation and in metabolic disorders, we hypothesised that the TNF superfamily (TNFSF) member 14 (LIGHT/TNFSF14) could be involved in the pathogenesis of type 2 diabetes mellitus. Plasma levels of LIGHT were measured in two cohorts of type 2 diabetes mellitus patients (191 Italian and 40 Norwegian). Human pancreatic islet cells and arterial endothelial cells were used to explore regulation and relevant effects of LIGHT in vitro. Our major findings were: (1) in both diabetic cohorts, plasma levels of LIGHT were significantly raised compared with sex- and age-matched healthy controls (n = 32); (2) enhanced release from activated platelets seems to be an important contributor to the raised LIGHT levels in type 2 diabetes mellitus; (3) in human pancreatic islet cells, inflammatory cytokines increased the release of LIGHT and upregulated mRNA and protein levels of the LIGHT receptors lymphotoxin β receptor (LTβR) and TNF receptor superfamily member 14 (HVEM/TNFRSF14); (4) in these cells, LIGHT attenuated the insulin release in response to high glucose at least partly via pro-apoptotic effects; and (5) in human arterial endothelial cells, glucose boosted inflammatory response to LIGHT, accompanied by an upregulation of mRNA levels of HVEM (also known as TNFRSF14) and LTβR (also known as LTBR). Our findings show that patients with type 2 diabetes mellitus are characterised by increased plasma LIGHT levels. Our in vitro findings suggest that LIGHT may contribute to the progression of type 2 diabetes mellitus by attenuating insulin secretion in pancreatic islet cells and by contributing to vascular inflammation.

  8. Repurposing Lesogaberan to Promote Human Islet Cell Survival and β-Cell Replication

    Directory of Open Access Journals (Sweden)

    Jide Tian

    2017-01-01

    Full Text Available The activation of β-cell’s A- and B-type gamma-aminobutyric acid receptors (GABAA-Rs and GABAB-Rs can promote their survival and replication, and the activation of α-cell GABAA-Rs promotes their conversion into β-cells. However, GABA and the most clinically applicable GABA-R ligands may be suboptimal for the long-term treatment of diabetes due to their pharmacological properties or potential side-effects on the central nervous system (CNS. Lesogaberan (AZD3355 is a peripherally restricted high-affinity GABAB-R-specific agonist, originally developed for the treatment of gastroesophageal reflux disease (GERD that appears to be safe for human use. This study tested the hypothesis that lesogaberan could be repurposed to promote human islet cell survival and β-cell replication. Treatment with lesogaberan significantly enhanced replication of human islet cells in vitro, which was abrogated by a GABAB-R antagonist. Immunohistochemical analysis of human islets that were grafted into immune-deficient mice revealed that oral treatment with lesogaberan promoted human β-cell replication and islet cell survival in vivo as effectively as GABA (which activates both GABAA-Rs and GABAB-Rs, perhaps because of its more favorable pharmacokinetics. Lesogaberan may be a promising drug candidate for clinical studies of diabetes intervention and islet transplantation.

  9. Pancreatic stellate cells enhance stem cell-like phenotypes in pancreatic cancer cells

    International Nuclear Information System (INIS)

    Hamada, Shin; Masamune, Atsushi; Takikawa, Tetsuya; Suzuki, Noriaki; Kikuta, Kazuhiro; Hirota, Morihisa; Hamada, Hirofumi; Kobune, Masayoshi; Satoh, Kennichi; Shimosegawa, Tooru

    2012-01-01

    Highlights: ► Pancreatic stellate cells (PSCs) promote the progression of pancreatic cancer. ► Pancreatic cancer cells co-cultured with PSCs showed enhanced spheroid formation. ► Expression of stem cell-related genes ABCG2, Nestin and LIN28 was increased. ► Co-injection of PSCs enhanced tumorigenicity of pancreatic cancer cells in vivo. ► This study suggested a novel role of PSCs as a part of the cancer stem cell niche. -- Abstract: The interaction between pancreatic cancer cells and pancreatic stellate cells (PSCs), a major profibrogenic cell type in the pancreas, is receiving increasing attention. There is accumulating evidence that PSCs promote the progression of pancreatic cancer by increasing cancer cell proliferation and invasion as well as by protecting them from radiation- and gemcitabine-induced apoptosis. Recent studies have identified that a portion of cancer cells, called “cancer stem cells”, within the entire cancer tissue harbor highly tumorigenic and chemo-resistant phenotypes, which lead to the recurrence after surgery or re-growth of the tumor. The mechanisms that maintain the “stemness” of these cells remain largely unknown. We hypothesized that PSCs might enhance the cancer stem cell-like phenotypes in pancreatic cancer cells. Indirect co-culture of pancreatic cancer cells with PSCs enhanced the spheroid-forming ability of cancer cells and induced the expression of cancer stem cell-related genes ABCG2, Nestin and LIN28. In addition, co-injection of PSCs enhanced tumorigenicity of pancreatic cancer cells in vivo. These results suggested a novel role of PSCs as a part of the cancer stem cell niche.

  10. Mesenchymal stem cell and derived exosome as small RNA carrier and Immunomodulator to improve islet transplantation.

    Science.gov (United States)

    Wen, Di; Peng, Yang; Liu, Di; Weizmann, Yossi; Mahato, Ram I

    2016-09-28

    Human bone marrow mesenchymal stem cells (hBMSCs) and their exosomes can suppress immune reaction and deliver small RNAs. Thus, they may improve islet transplantation by delivering small RNAs for promoting islet function and inhibiting immune rejection. Here, we proposed an hBMSC and its exosome-based therapy to overcome immune rejection and poor islet function, both of which hinder the success of islet transplantation. We found overexpressed siFas and anti-miR-375 in plasmid encoding shFas and anti-miR-375 transfected hBMSC-derived exosomes, which silenced Fas and miR-375 of human islets and improved their viability and function against inflammatory cytokines. This plasmid transfected hBMSCs downregulated Fas and miR-375 of human islets in a humanized NOD scid gamma (NSG) mouse model, whose immune reaction was inhibited by injecting hBMSC and peripheral blood mononuclear cell (PBMC) co-cultured exosomes. These exosomes suppressed immune reaction by inhibiting PBMC proliferation and enhancing regulatory T cell (Treg) function. Collectively, our studies elucidated the mechanisms of RNA delivery from hBMSCs to human islets and the immunosuppressive effect of hBMSC and peripheral blood mononuclear cell co-cultured exosomes for improving islet transplantation. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Evaluation of Porcine Pancreatic Islets Transplanted in the Kidney Capsules of Diabetic Mice Using a Clinically Approved Superparamagnetic Iron Oxide (SPIO) and a 1.5T MR Scanner

    International Nuclear Information System (INIS)

    Kim, Hoe Suk; Kim, Hyoung Su; Park, Kyong Soo; Moon, Woo Kyung

    2010-01-01

    To evaluate transplanted porcine pancreatic islets in the kidney capsules of diabetic mice using a clinically approved superparamagnetic iron oxide (SPIO) and a 1.5T MR scanner. Various numbers of porcine pancreatic islets labeled with Resovist, a carboxydextran-coated SPIO, were transplanted into the kidney capsules of normal mice and imaged with a 3D FIESTA sequence using a 1.5T clinical MR scanner. Labeled (n = 3) and unlabeled (n = 2) islets were transplanted into the kidney capsules of streptozotocin-induced diabetic mice. Blood glucose levels and MR signal intensities were monitored for 30 days post-transplantation. There were no significant differences in viability or insulin secretion between labeled and unlabeled islets. A strong correlation (γ 2 > 0.94) was evident between the number of transplanted islets and T 2 relaxation times quantified by MRI. Transplantation with labeled or unlabeled islets helped restore normal sustained glucose levels in diabetic mice, and nephrectomies induced the recurrence of diabetes. The MR signal intensity of labeled pancreatic islets decreased by 80% over 30 days. The transplantation of SPIO-labeled porcine islets into the kidney capsule of diabetic mice allows to restore normal glucose levels, and these islets can be visualized and quantified using a 1.5T clinical MR scanner

  12. G protein-coupled receptor 39 deficiency is associated with pancreatic islet dysfunction

    DEFF Research Database (Denmark)

    Holst, Birgitte; Egerod, Kristoffer L; Jin, Chunyu

    2009-01-01

    G protein-coupled receptor (GPR)-39 is a seven-transmembrane receptor expressed mainly in endocrine and metabolic tissues that acts as a Zn(++) sensor signaling mainly through the G(q) and G(12/13) pathways. The expression of GPR39 is regulated by hepatocyte nuclear factor (HNF)-1alpha and HNF-4...... tolerance both during oral and iv glucose tolerance tests, and Gpr39(-/-) mice had decreased plasma insulin response to oral glucose. Islet architecture was normal in the Gpr39 null mice, but expression of Pdx-1 and Hnf-1alpha was reduced. Isolated, perifused islets from Gpr39 null mice secreted less...

  13. Automated digital image analysis of islet cell mass using Nikon's inverted eclipse Ti microscope and software to improve engraftment may help to advance the therapeutic efficacy and accessibility of islet transplantation across centers.

    Science.gov (United States)

    Gmyr, Valery; Bonner, Caroline; Lukowiak, Bruno; Pawlowski, Valerie; Dellaleau, Nathalie; Belaich, Sandrine; Aluka, Isanga; Moermann, Ericka; Thevenet, Julien; Ezzouaoui, Rimed; Queniat, Gurvan; Pattou, Francois; Kerr-Conte, Julie

    2015-01-01

    Reliable assessment of islet viability, mass, and purity must be met prior to transplanting an islet preparation into patients with type 1 diabetes. The standard method for quantifying human islet preparations is by direct microscopic analysis of dithizone-stained islet samples, but this technique may be susceptible to inter-/intraobserver variability, which may induce false positive/negative islet counts. Here we describe a simple, reliable, automated digital image analysis (ADIA) technique for accurately quantifying islets into total islet number, islet equivalent number (IEQ), and islet purity before islet transplantation. Islets were isolated and purified from n = 42 human pancreata according to the automated method of Ricordi et al. For each preparation, three islet samples were stained with dithizone and expressed as IEQ number. Islets were analyzed manually by microscopy or automatically quantified using Nikon's inverted Eclipse Ti microscope with built-in NIS-Elements Advanced Research (AR) software. The AIDA method significantly enhanced the number of islet preparations eligible for engraftment compared to the standard manual method (p image analysis utilizing the Nikon Instruments software is an unbiased, simple, and reliable teaching tool to comprehensively assess the individual size of each islet cell preparation prior to transplantation. Implementation of this technology to improve engraftment may help to advance the therapeutic efficacy and accessibility of islet transplantation across centers.

  14. Radiocolloid Uptake in the Pancreas Islet Cell Tumor: Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Yang, W. J.; Chung, S. K.; Yeon, S. K.; Shinn, K. S.; Bahk, Y. W. [Catholic University College of Medicine, Seoul (Korea, Republic of)

    1994-03-15

    Colloid uptake in various hepatic conditions such as focal nodular hyperplasia, regenerating nodular in the cirrhotic liver, hamartoma, hemangioma and rarely hepatoma has been documented. Extrahepatic tumors may show colloid uptake and they include splenic hemangioma, malignant fibrous histiocytoma, breast carcinoma and Kaposi's sarcoma. The mechanism of colloid uptake in those lesions is associated with phagocytic activity in or around the tumors. We report a pancreas islet cell tumor that showed colloid uptake on {sup 99m}Tc-phytate liver scan without histologic evidence of phagocytosis by tumor cells or infiltration of phagocytes in the tumor. Microscopically the tumor was highly vascular and showed diffuse hemorrhage throughout the tumor. We postulated that extravasation of the colloid into the tumor interstitium caused nonspecific colloid uptake in this tumor. It is expected that hemorrhagic tumor may show nonspecific colloid uptake without phagocytosis in or about the lesion.

  15. Radiocolloid Uptake in the Pancreas Islet Cell Tumor: Case Report

    International Nuclear Information System (INIS)

    Yang, W. J.; Chung, S. K.; Yeon, S. K.; Shinn, K. S.; Bahk, Y. W.

    1994-01-01

    Colloid uptake in various hepatic conditions such as focal nodular hyperplasia, regenerating nodular in the cirrhotic liver, hamartoma, hemangioma and rarely hepatoma has been documented. Extrahepatic tumors may show colloid uptake and they include splenic hemangioma, malignant fibrous histiocytoma, breast carcinoma and Kaposi's sarcoma. The mechanism of colloid uptake in those lesions is associated with phagocytic activity in or around the tumors. We report a pancreas islet cell tumor that showed colloid uptake on 99m Tc-phytate liver scan without histologic evidence of phagocytosis by tumor cells or infiltration of phagocytes in the tumor. Microscopically the tumor was highly vascular and showed diffuse hemorrhage throughout the tumor. We postulated that extravasation of the colloid into the tumor interstitium caused nonspecific colloid uptake in this tumor. It is expected that hemorrhagic tumor may show nonspecific colloid uptake without phagocytosis in or about the lesion.

  16. Impaired growth of pancreatic exocrine cells in transgenic mice expressing human activin βE subunit

    International Nuclear Information System (INIS)

    Hashimoto, Osamu; Ushiro, Yuuki; Sekiyama, Kazunari; Yamaguchi, Osamu; Yoshioka, Kazuki; Mutoh, Ken-Ichiro; Hasegawa, Yoshihisa

    2006-01-01

    Activins, TGF-β superfamily members, have multiple functions in a variety of cells and tissues. Recently, additional activin β subunit genes, βC and βE, have been identified. To explore the role of activin E, we created transgenic mice overexpressing human activin βE subunit. There were pronounced differences in the pancreata of the transgenic animals as compared with their wild-type counterparts. Pancreatic weight, expressed relative to total body weight, was significantly reduced. Histologically, adipose replacement of acini in the exocrine pancreas was observed. There was a significant decrease in the number of PCNA-positive cells in the acinar cells, indicating reduced proliferation in the exocrine pancreas of the transgenic mice. However, quantitative pancreatic morphometry showed that the total number and mass of the islets of the transgenic mice were comparable with those of the nontransgenic control mice. Our findings suggest a role for activin E in regulating the proliferation of pancreatic exocrine cells

  17. Polyphenol-Rich Extract of Syzygium cumini Leaf Dually Improves Peripheral Insulin Sensitivity and Pancreatic Islet Function in Monosodium L-Glutamate-Induced Obese Rats

    Science.gov (United States)

    Sanches, Jonas R.; França, Lucas M.; Chagas, Vinicyus T.; Gaspar, Renato S.; dos Santos, Kayque A.; Gonçalves, Luciana M.; Sloboda, Deborah M.; Holloway, Alison C.; Dutra, Richard P.; Carneiro, Everardo M.; Cappelli, Ana Paula G.; Paes, Antonio Marcus de A.

    2016-01-01

    Syzygium cumini (L.) Skeels (Myrtaceae) has been traditionally used to treat a number of illnesses. Ethnopharmacological studies have particularly addressed antidiabetic and metabolic-related effects of extracts prepared from its different parts, especially seed, and pulp-fruit, however. there is a lack of studies on phytochemical profile and biological properties of its leaf. As there is considerable interest in bioactive compounds to treat metabolic syndrome and its clustered risk factors, we sought to characterize the metabolic effects of hydroethanolic extract of S. cumini leaf (HESc) on lean and monosodium L-glutamate (MSG)-induced obese rats. HPLC-MS/MS characterization of the HESc polyphenolic profile, at 254 nm, identified 15 compounds pertaining to hydrolysable tannin and flavanol subclasses. At 60 days of age, both groups were randomly assigned to receive HESc (500 mg/kg) or vehicle for 30 days. At the end of treatment, obese+HESc exhibited significantly lower body weight gain, body mass index, and white adipose tissue mass, compared to obese rats receiving vehicle. Obese rats treated with HESc showed a twofold increase in lipolytic activity in the periepididymal fat pad, as well as, brought triglyceride levels in serum, liver and skeletal muscle back to levels close those found in lean animals. Furthermore, HESc also improved hyperinsulinemia and insulin resistance in obese+HESc rats, which resulted in partial reversal of glucose intolerance, as compared to obese rats. HESc had no effect in lean rats. Assessment of ex vivo glucose-stimulated insulin secretion showed HESc potentiated pancreatic function in islets isolated from both lean and obese rats treated with HESc. In addition, HESc (10–1000 μg/mL) increased glucose stimulated insulin secretion from both isolated rat islets and INS-1E β-cells. These data demonstrate that S. cumini leaf improved peripheral insulin sensitivity via stimulating/modulating β-cell insulin release, which was associated

  18. Polyphenol-rich extract of Syzygium cumini leaf dually improves peripheral insulin sensitivity and pancreatic islet function in monosodium L-glutamate-induced obese rats

    Directory of Open Access Journals (Sweden)

    Jonas Rodrigues Sanches

    2016-03-01

    Full Text Available Syzygium cumini (L. Skeels (Myrtaceae has been traditionally used to treat a number of illnesses. Ethnopharmacological studies have particularly addressed antidiabetic and metabolic-related effects of extracts prepared from its different parts, especially seed and pulp-fruit, however there is a lack of studies on phytochemical profile and biological properties of its leaf. As there is considerable interest in bioactive compounds to treat metabolic syndrome and its clustered risk factors, we sought to characterize the metabolic effects of hydroethanolic extract of S. cumini leaf (HESc on lean and monosodium L-glutamate (MSG-induced obese rats. HPLC-MS/MS characterization of the HESc polyphenolic profile, at 254 nm, identified 15 compounds pertaining to hydrolysable tannin and flavanol subclasses. At 60 days of age, both groups were randomly assigned to receive HESc (500 mg/kg or vehicle for 30 days. At the end of treatment, obese+HESc exhibited significantly lower body weight gain, body mass index, and white adipose tissue mass, compared to obese rats receiving vehicle. Obese rats treated with HESc showed a 2-fold increase in lipolytic activity in the periepididymal fat pad, as well as, brought triglyceride levels in serum, liver and skeletal muscle back to levels close those found in lean animals. Furthermore, HESc also improved hyperinsulinemia and insulin resistance in obese+HESc rats, which resulted in partial reversal of glucose intolerance, as compared to obese rats. HESc had no effect in lean rats. Assessment of ex vivo glucose-stimulated insulin secretion showed HESc potentiated pancreatic function in islets isolated from both lean and obese rats treated with HESc. In addition, HESc (10 – 1000 ug/mL increased glucose stimulated insulin secretion from both isolated rat islets and INS-1E beta cells. These data demonstrate that S. cumini leaf improved peripheral insulin sensitivity via stimulating/modulating beta cell insulin release

  19. Repeated Gene Transfection Impairs the Engraftment of Transplanted Porcine Neonatal Pancreatic Cells

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    Min Koo Seo

    2011-02-01

    Full Text Available BackgroundPreviously, we reported that neonatal porcine pancreatic cells transfected with hepatocyte growth factor (HGF gene in an Epstein-Barr virus (EBV-based plasmid (pEBVHGF showed improved proliferation and differentiation compared to those of the control. In this study, we examined if pancreatic cells transfected repeatedly with pEBVHGF can be successfully grafted to control blood glucose in a diabetes mouse model.MethodsNeonatal porcine pancreatic cells were cultured as a monolayer and were transfected with pEBVHGF every other day for a total of three transfections. The transfected pancreatic cells were re-aggregated and transplanted into kidney capsules of diabetic nude mice or normal nude mice. Blood glucose level and body weight were measured every other day after transplantation. The engraftment of the transplanted cells and differentiation into beta cells were assessed using immunohistochemistry.ResultsRe-aggregation of the pancreatic cells before transplantation improved engraftment of the cells and facilitated neovascularization of the graft. Right before transplantation, pancreatic cells that were transfected with pEBVHGF and then re-aggregated showed ductal cell marker expression. However, ductal cells disappeared and the cells underwent fibrosis in a diabetes mouse model two to five weeks after transplantation; these mice also did not show controlled blood glucose levels. Furthermore, pancreatic cells transplanted into nude mice with normal blood glucose showed poor graft survival regardless of the type of transfected plasmid (pCEP4, pHGF, or pEBVHGF.ConclusionFor clinical application of transfected neonatal porcine pancreatic cells, further studies are required to develop methods of overcoming the damage for the cells caused by repeated transfection and to re-aggregate them into islet-like structures.

  20. Homogenization of heterogeneously coupled bistable ODE's - applied to excitation waves in pancreatic islets of Langerhans

    DEFF Research Database (Denmark)

    Pedersen, Morten Gram

    2004-01-01

    We consider a lattice of coupled identical differential equations. The coupling is between nearest neighbors and of resistance type, but the strength of coupling varies from site to site. Such a lattice can, for example, model an islet of Langerhans, where the sites in the lattice model individua...

  1. Improved biocompatibility but limited graft survival after purification of alginate for microencapsulation of pancreatic islets

    NARCIS (Netherlands)

    DeVos, P; DeHaan, BJ; Wolters, GHJ; Strubbe, JH; VanSchilfgaarde, R; van Schilfgaarde, P.

    Graft failure of alginate-polylysine microencapsulated islets is often interpreted as the consequence of a non-specific foreign body reaction against the microcapsules, initiated by impurities present in crude alginate. The aim of the present study was to investigate if purification of the alginate

  2. Protective Effects of the Mushroom Lactarius deterrimus Extract on Systemic Oxidative Stress and Pancreatic Islets in Streptozotocin-Induced Diabetic Rats

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    Mirjana Mihailović

    2015-01-01

    Full Text Available The aim of this study was to assess the in vivo effects of the extract of the medicinal mushroom, Lactarius deterrimus, when administered (60 mg/kg, i.p. daily for four weeks to streptozotocin- (STZ- induced diabetic rats. Diabetic rats treated with the L. deterrimus extract displayed several improved biochemical parameters in the circulation: reduced hyperglycemia, lower triglyceride concentration and reduced glycated hemoglobin, glycated serum protein, and advanced glycation end product (AGE levels. This treatment also adjusted the diabetes-induced redox imbalance. Thus, higher activities of the antioxidative enzymes, superoxide dismutase, and catalase in the circulation were accompanied by increased levels of free intracellular thiols and glutathionylated proteins after treatment with the L. deterrimus extract. In addition to a systemic antioxidant effect, the administration of the extract to diabetic rats also had a positive localized effect on pancreatic islets where it decreased AGE formation, and increased the expression of chemokine CXCL12 protein that mediates the restoration of β-cell population through the activation of the serine/threonine-specific Akt protein kinase prosurvival pathway. As a result, the numbers of proliferating cell nuclear antigen- (PCNA- and insulin-positive β-cells were increased. These results show that the ability of the L. deterrimus extract to alleviate oxidative stress and increase β-cell mass represents a therapeutic potential for diabetes management.

  3. Enrichment of putative pancreatic progenitor cells from mice by sorting for prominin1 (CD133) and platelet-derived growth factor receptor beta.

    Science.gov (United States)

    Hori, Yuichi; Fukumoto, Miki; Kuroda, Yoshikazu

    2008-11-01

    Success in islet transplantation-based therapies for type 1 diabetes mellitus and an extreme shortage of pancreatic islets have motivated recent efforts to develop renewable sources of islet-replacement tissue. Although pancreatic progenitor cells hold a promising potential, only a few attempts have been made at the prospective isolation of pancreatic stem/progenitor cells, because of the lack of specific markers and the development of effective cell culture methods. We found that prominin1 (also known as CD133) recognized the undifferentiated epithelial cells, whereas platelet-derived growth factor receptor beta (PDGFRbeta) was expressed on the mesenchymal cells in the mouse embryonic pancreas. We then developed an isolation method for putative stem/progenitor cells by flow cytometric cell sorting and characterized their potential for differentiation to pancreatic tissue using both in vitro and in vivo protocols. Flow cytometry and the subsequent reverse transcription-polymerase chain reaction and microarray analysis revealed pancreatic epithelial progenitor cells to be highly enriched in the prominin1(high)PDGFRbeta(-) cell population. During in vivo differentiation, these cell populations were able to differentiate into endocrine, exocrine, and ductal tissues, including the formation of an insulin-producing cell cluster. We established the prospective isolation of putative pancreatic epithelial progenitor cells by sorting for prominin1 and PDGFRbeta. Since this strategy is based on the cell surface markers common to human and rodents, these findings may lead to the development of new strategies to derive transplantable islet-replacement tissues from human pancreatic stem/progenitor cells. Disclosure of potential conflicts of interest is found at the end of this article.

  4. Liposome-mediated transfer of IL-1 receptor antagonist gene to dispersed islet cells does not prevent recurrence of disease in syngeneically transplanted NOD mice

    DEFF Research Database (Denmark)

    Saldeen, J; Sandler, S; Bendtzen, K

    2000-01-01

    transplanted non-obese diabetic (NOD) mice. NOD mouse islet cells were transfected using liposome-mediated gene transfer with a human IL-1ra cDNA construct and transplanted two days later to prediabetic NOD mice. Graft infiltration and destruction were monitored three, five and eight days posttransplantation...... by histology and determination of insulin and cytokine content. IL-1ra gene transfer resulted in transient expression of IL-1ra protein in islet cells in vitro as assessed by ELISA and of IL-1ra mRNA in transplanted islets as revealed by RT-PCR. However, both control and IL-1ra transfected NOD grafts exhibited......IL-1beta is cytotoxic to pancreatic beta-cells in vitro but its role in the vicinity of beta-cells in vivo is unknown. We explored whether liposome-mediated transfer of the interleukin 1 receptor antagonist (IL-1ra) gene to islet cells might prevent recurrence of disease in syngeneically...

  5. MRI of islet cell tumors of the pancreas

    International Nuclear Information System (INIS)

    Ohtomo, Kuni; Itai, Yuji; Yoshikawa, Koki; Kokubo, Taka; Yashiro, Naofumi; Iio, Masahiro; Atomi, Yu

    1986-01-01

    Magnetic resonance imaging (MRI) was performed in five patients with islet cell tumors of the pancreas, using 0.35 T and 1.5 T superconductive magnets. MRI identified tumors in 3 patients. The tumors seen in the 3 patients appeared as areas of higher signal intensity than the liver on spin-echo (SE) images with repetition time of 1,600 msec/echo time of 35 or 70 msec, and as areas of similar or lower intensity on SE 400/35 or 70 images. The tumor imaged by SE techniques with 1,600/35 msec, 400/35 msec, and 1,600/35 or 70 msec in one patient was manifested by prolongation of T1 and T2, as compared with the liver. Tumors in the remaining two patients, which were not detected on MRI, were 15 mm or smaller. MRI remains to be improved in the visualization of small lesions. (Namekawa, K.)

  6. Glucocorticoids Inhibit Basal and Hormone-Induced Serotonin Synthesis in Pancreatic Beta Cells.

    Directory of Open Access Journals (Sweden)

    Moina Hasni Ebou

    Full Text Available Diabetes is a major complication of chronic Glucocorticoids (GCs treatment. GCs induce insulin resistance and also inhibit insulin secretion from pancreatic beta cells. Yet, a full understanding of this negative regulation remains to be deciphered. In the present study, we investigated whether GCs could inhibit serotonin synthesis in beta cell since this neurotransmitter has been shown to be involved in the regulation of insulin secretion. To this aim, serotonin synthesis was evaluated in vitro after treatment with GCs of either islets from CD1 mice or MIN6 cells, a beta-cell line. We also explored the effect of GCs on the stimulation of serotonin synthesis by several hormones such as prolactin and GLP 1. We finally studied this regulation in islet in two in vivo models: mice treated with GCs and with liraglutide, a GLP1 analog, and mice deleted for the glucocorticoid receptor in the pancreas. We showed in isolated islets and MIN6 cells that GCs decreased expression and activity of the two key enzymes of serotonin synthesis, Tryptophan Hydroxylase 1 (Tph1 and 2 (Tph2, leading to reduced serotonin contents. GCs also blocked the induction of serotonin synthesis by prolactin or by a previously unknown serotonin activator, the GLP-1 analog exendin-4. In vivo, activation of the Glucagon-like-Peptide-1 receptor with liraglutide during 4 weeks increased islet serotonin contents and GCs treatment prevented this increase. Finally, islets from mice deleted for the GR in the pancreas displayed an increased expression of Tph1 and Tph2 and a strong increased serotonin content per islet. In conclusion, our results demonstrate an original inhibition of serotonin synthesis by GCs, both in basal condition and after stimulation by prolactin or activators of the GLP-1 receptor. This regulation may contribute to the deleterious effects of GCs on beta cells.

  7. Divergent Effects of Dendritic Cells on Pancreatitis

    Science.gov (United States)

    2015-09-01

    role of dendritic cells in pancreatitis. Dendritic cells are professional antigen presenting cells which initiate innate and adaptive immune... Lymphoid -tissue-specific homing of bone- marrow-derived dendritic cells . Blood. 113:6638–6647. http://dx.doi .org/10.1182/blood-2009-02-204321 Dapito...Award Number: W81XWH-12-1-0313 TITLE: Divergent Effects of Dendritic Cells on Pancreatitis PRINCIPAL INVESTIGATOR: Dr. George Miller

  8. An SCFFBXO28 E3 Ligase Protects Pancreatic β-Cells from Apoptosis

    Directory of Open Access Journals (Sweden)

    Kanaka Durga Devi Gorrepati

    2018-03-01

    Full Text Available Loss of pancreatic β-cell function and/or mass is a central hallmark of all forms of diabetes but its molecular basis is incompletely understood. β-cell apoptosis contributes to the reduced β-cell mass in diabetes. Therefore, the identification of important signaling molecules that promote β-cell survival in diabetes could lead to a promising therapeutic intervention to block β-cell decline during development and progression of diabetes. In the present study, we identified F-box protein 28 (FBXO28, a substrate-recruiting component of the Skp1-Cul1-F-box (SCF ligase complex, as a regulator of pancreatic β-cell survival. FBXO28 was down-regulated in β-cells and in isolated human islets under diabetic conditions. Consistently, genetic silencing of FBXO28 impaired β-cell survival, and restoration of FBXO28 protected β-cells from the harmful effects of the diabetic milieu. Although FBXO28 expression positively correlated with β-cell transcription factor NEUROD1 and FBXO28 depletion also reduced insulin mRNA expression, neither FBXO28 overexpression nor depletion had any significant impact on insulin content, glucose-stimulated insulin secretion (GSIS or on other genes involved in glucose sensing and metabolism or on important β-cell transcription factors in isolated human islets. Consistently, FBXO28 overexpression did not further alter insulin content and GSIS in freshly isolated islets from patients with type 2 diabetes (T2D. Our data show that FBXO28 improves pancreatic β-cell survival under diabetogenic conditions without affecting insulin secretion, and its restoration may be a novel therapeutic tool to promote β-cell survival in diabetes.

  9. Stimulation by ATP of proinsulin to insulin conversion in isolated rat pancreatic islet secretory granules. Association with the ATP-dependent proton pump

    International Nuclear Information System (INIS)

    Rhodes, C.J.; Lucas, C.A.; Mutkoski, R.L.; Orci, L.; Halban, P.A.

    1987-01-01

    Isolated rat pancreatic islets were pulse-labeled for 5 min with [ 3 H]leucine then chased for 25 min, during which time endogenously labeled [ 3 H]proinsulin becomes predominantly compartmented in immature secretory granules. The islets were then homogenized in isotonic sucrose (pH 7.4) and a beta-granule preparation obtained by differential centrifugation and discontinuous sucrose gradient ultracentrifugation. This preparation was enriched 8-fold in beta-granules. Aside from contamination with mitochondria and a limited number of lysosomes, the beta-granule preparation was essentially free of any other organelles involved in proinsulin synthesis and packaging (i.e. microsomal elements and, more particularly, Golgi complex). Conversion of endogenously labeled [ 3 H]proinsulin was followed in this beta-granule fraction for up to 2 h at 37 degrees C in a buffer (pH 7.3) that mimicked the cationic constituents of B-cell cytosol, during which time 92% of the beta-granules remained intact. Proinsulin conversion was analyzed by high performance liquid chromatography. The rate of proinsulin conversion to insulin was stimulated by 2.2 +/- 0.1-fold (n = 6) (at a 60-min incubation) in the presence of ATP (2 mM) and an ATP regenerating system compared to beta-granule preparations incubated without ATP. This ATP stimulation was abolished in the presence of beta-granule proton pump ATPase inhibitors (tributyltin, 2.5 microM, or 1,3-dicyclohexylcarbodiimide, 50 microM). Inhibitors of mitochondrial proton pump ATPases had no effect on the ATP stimulation of proinsulin conversion. When granules were incubated in a more acidic buffer, proinsulin conversion was increased relative to that at pH 7.3. At pH 5.5, ATP no longer stimulated conversion, and tributyltin and 1,3-dicyclohexylcarbodiimide had no effect

  10. Birth and death of human β-cells in pancreas from cadaver donors, autopsies, surgical specimens, and islets transplanted into mice

    Science.gov (United States)

    Caballero, Francisco; Siniakowicz, Karolina; Jennifer-Hollister-Lock; Duran, Luisa; Katsuta, Hitoshi; Yamada, Takatsugu; Lei, Ji; Deng, Shaoping; Westermark, Gunilla T.; Markmann, James; Bonner-Weir, Susan; Weir, Gordon C.

    2013-01-01

    There is great interest in the potential of the human endocrine pancreas for regeneration by β-cell replication or neogenesis. Our aim was to explore this potential in adult human pancreases and in both islet and exocrine tissue transplanted into mice. The design was to examine pancreases obtained from cadaver donors, autopsies and fresh surgical specimens and compare these findings with those obtained from islet and duct tissue grafted into the kidney. Islets and exocrine tissue were transplanted into normoglycemic ICR/SCID mice and studied 4 and 14 wk later. β-cell replication as assessed by double staining for insulin and Ki67 was 0.22 ± 0.03 % at 4 wk and 0.13 ± 0.03 % at 14 wk. In contrast, no evidence of β-cell replication could be found in 11 cadaver donor and 10 autopsy pancreases. However, Ki67 staining of β-cells in frozen sections obtained at surgery was comparable to that found in transplanted islets. Evidence for neogenesis in transplanted pancreatic exocrine tissue was supported by finding β-cells within the duct epithelium, and the presence of cells double stained for insulin and cytokeratin 19 (CK19). However, β-cells within the ducts never constituted more than 1% of the CK19 positive cells. With confocal microscopy, 7 of 12 examined cells expressed both markers, consistent with a neogeneic process. Mice with grafts containing islet or exocrine tissue were treated with various combinations exendin-4, gastrin and epidermal growth factor; none increased β-cell replication or stimulated neogenesis. In summary, human β-cells replicate at a low level in islets transplanted into mice and in surgical pancreatic frozen sections but rarely in cadaver donor or autopsy pancreases. The absence of β-cell replication in many adult cadaver or autopsy pancreases could, in part, be an artifact of the postmortem state. Thus, it appears that adult human β-cells maintain a low level of turnover through replication and neogenesis. PMID:23321263

  11. Birth and death of human β-cells in pancreases from cadaver donors, autopsies, surgical specimens, and islets transplanted into mice.

    Science.gov (United States)

    Caballero, Francisco; Siniakowicz, Karolina; Hollister-Lock, Jennifer; Duran, Luisa; Katsuta, Hitoshi; Yamada, Takatsugu; Lei, Ji; Deng, Shaoping; Westermark, Gunilla T; Markmann, James; Bonner-Weir, Susan; Weir, Gordon C

    2014-02-01

    There is great interest in the potential of the human endocrine pancreas for regeneration by β-cell replication or neogenesis. Our aim was to explore this potential in adult human pancreases and in both islet and exocrine tissue transplanted into mice. The design was to examine pancreases obtained from cadaver donors, autopsies, and fresh surgical specimens and compare these findings with those obtained from islet and duct tissue grafted into the kidney. Islets and exocrine tissue were transplanted into normoglycemic ICR-SCID mice and studied 4 and 14 weeks later. β-Cell replication, as assessed by double staining for insulin and Ki67, was 0.22 ± 0.03% at 4 weeks and 0.13 ± 0.03% at 14 weeks. In contrast, no evidence of β-cell replication could be found in 11 cadaver donor and 10 autopsy pancreases. However, Ki67 staining of β-cells in frozen sections obtained at surgery was comparable to that found in transplanted islets. Evidence for neogenesis in transplanted pancreatic exocrine tissue was supported by finding β-cells within the duct epithelium and the presence of cells double stained for insulin and cytokeratin 19 (CK19). However, β-cells within the ducts never constituted more than 1% of the CK19-positive cells. With confocal microscopy, 7 of 12 examined cells expressed both markers, consistent with a neogeneic process. Mice with grafts containing islet or exocrine tissue were treated with various combinations of exendin-4, gastrin, and epidermal growth factor; none increased β-cell replication or stimulated neogenesis. In summary, human β-cells replicate at a low level in islets transplanted into mice and in surgical pancreatic frozen sections, but rarely in cadaver donor or autopsy pancreases. The absence of β-cell replication in many adult cadaver or autopsy pancreases could, in part, be an artifact of the postmortem state. Thus, it appears that adult human β-cells maintain a low level of turnover through replication and neogenesis.

  12. A second glucagon in the pancreatic islets of the daddy sculpin Cottus scorpius.

    Science.gov (United States)

    Cutfield, S M; Cutfield, J F

    1993-09-01

    The peptide hormone glucagon has been isolated from the islet tissue (Brockmann bodies) of the teleost Cottus scorpius (daddy sculpin) and sequenced. The sequence is HSEGTSNDYSKYLEDRKAQDFVQWLMNN differing at four positions from the glucagon found earlier in the same species by Conlon and coworkers (1987b, Eur. J. Biochem, 164, 117-122). Thus sculpin, in common with anglerfish, possesses two distinct glucagons. Comparative sequence data are presented as a phylogenetic tree.

  13. Combined strategy of endothelial cells coating, Sertoli cells coculture and infusion improves vascularization and rejection protection of islet graft.

    Directory of Open Access Journals (Sweden)

    Yang Li

    Full Text Available Improving islet graft revascularization and inhibiting rejection become crucial tasks for prolonging islet graft survival. Endothelial cells (ECs are the basis of islet vascularization and Sertoli cells (SCs have the talent to provide nutritional support and exert immunosuppressive effects. We construct a combined strategy of ECs coating in the presence of nutritious and immune factors supplied by SCs in a co-culture system to investigate the effect of vascularization and rejection inhibition for islet graft. In vivo, the combined strategy improved the survival and vascularization as well as inhibited lymphocytes and inflammatory cytokines. In vitro, we found the combinatorial strategy improved the function of islets and the effect of ECs-coating on islets. Combined strategy treated islets revealed higher levels of anti-apoptotic signal molecules (Bcl-2 and HSP-32, survival and function related molecules (PDX-1, Ki-67, ERK1/2 and Akt and demonstrated increased vascular endothelial growth factor receptor 2 (KDR and angiogenesis signal molecules (FAk and PLC-γ. SCs effectively inhibited the activation of lymphocyte stimulated by islets and ECs. Predominantly immunosuppressive cytokines could be detected in culture supernatants of the SCs coculture group. These results suggest that ECs-coating and Sertoli cells co-culture or infusion synergistically enhance islet survival and function after transplantation.

  14. GLYCOL METHACRYLATE EMBEDDING OF ALGINATE-POLYLYSINE MICROENCAPSULATED PANCREATIC-ISLETS

    NARCIS (Netherlands)

    FRITSCHY, WM; GERRITS, PO; WOLTERS, GHJ; PASMA, A; VANSCHILFGAARDE, R

    A method for processing and embedding alginate-polylysine microencapsulated pancreatic tissue in glycol methacrylate resin (GMA) is described. Fixation in 4% phosphate buffered formaldehyde, processing in ascending concentrations of glycol methacrylate monomer and embedding in Technovit 7100 results

  15. Chemokine receptor expression in tumour islets and stroma in non-small cell lung cancer

    International Nuclear Information System (INIS)

    Ohri, Chandra M; Shikotra, Aarti; Green, Ruth H; Waller, David A; Bradding, Peter

    2010-01-01

    We have previously demonstrated that tumour islet infiltration by macrophages is associated with extended survival (ES) in NSCLC. We therefore hypothesised that patients with improved survival would have high tumour islet expression of chemokine receptors known to be associated with favourable prognosis in cancer. This study investigated chemokine receptor expression in the tumour islets and stroma in NSCLC. We used immunohistochemistry to identify cells expressing CXCR1, CXCR2, CXCR3, CXCR4, CXCR5 and CCR1 in the tumour islets and stroma in 20 patients with surgically resected NSCLC. Correlations were made with macrophage and mast cell expression. There was increased expression of CXCR2, CXCR3, and CCR1 in the tumour islets of ES compared with poor survival (PS) patients (p = 0.007, 0.01, and 0.002, respectively). There was an association between 5 year survival and tumour islet CXCR2, CXCR3 and CCR1 density (p = 0.02, 0.003 and <0.001, respectively) as well as stromal CXCR3 density (p = 0.003). There was a positive correlation between macrophage density and CXCR3 expression (r s = 0.520, p = 0.02) and between mast cell density and CXCR3 expression (r s = 0.499, p = 0.03) in the tumour islets. Above median expression of CXCR2, CXCR3 and CCR1 in the tumour islets is associated with increased survival in NSCLC, and expression of CXCR3 correlates with increased macrophage and mast cell infiltration in the tumour islets

  16. The islet beta-cell: fuel responsive and vulnerable.

    Science.gov (United States)

    Nolan, Christopher J; Prentki, Marc

    2008-10-01

    The pancreatic beta-cell senses blood nutrient levels and is modulated by neurohormonal signals so that it secretes insulin according to the need of the organism. Nutrient sensing involves marked metabolic activation, resulting in the production of coupling signals that promote insulin biosynthesis and secretion. The beta-cell's high capacity for nutrient sensing, however, necessitates reduced protection to nutrient toxicity. This potentially explains why in susceptible individuals, chronic fuel surfeit results in beta-cell failure and type 2 diabetes. Here we discuss recent insights into first, the biochemical basis of beta-cell signaling in response to glucose, amino acids and fatty acids, and second, beta-cell nutrient detoxification. We emphasize the emerging role of glycerolipid/fatty acid cycling in these processes.

  17. First Identification of the Toxicity of Microcystins on Pancreatic Islet Function in Humans and the Involved Potential Biomarkers.

    Science.gov (United States)

    Zhao, Yanyan; Xue, Qingju; Su, Xiaomei; Xie, Liqiang; Yan, Yunjun; Wang, Lixiao; Steinman, Alan D

    2016-03-15

    Microcystins (MCs) produced by cyanobacteria have been recognized as a major public health threat. However, the toxicity of MCs to humans is still largely unknown. In this study, we examined the changes in pancreatic islet function in fishers exposed to ambient levels of MCs at Lake Taihu and, using a mouse model, explored the molecular mechanisms involved in toxicity. MCs content in the serum of fishers tested positive, with a range from 0.10 to 0.64 μg/L. Both lower blood insulin levels (2.26 ± 0.96 μIU/mL) and impaired fasting glucose were found in participants from the Meiliang Bay area in Lake Taihu, where MC-LR levels were substantially greater than the MC threshold established by WHO for drinking water. Animal experiments showed that glucose level increased by 27.9% in mice exposed to 5 μg/kg bw and decreased by 41.5% in mice exposed to 20 μg/kg bw. Blood insulin levels declined by 21.9% and 56.2% in mice exposed to 5 and 20 μg/kg bw MC-LR, respectively, which was consistent with the results observed in fishers. Furthermore, the diabetes gene pdx1 and several other proteins (such as Ppp3ca, Ide, Marcks, Pgk1, Suclg1, Ndufs4) involved in insulin secretion were identified for the first time in mice following MC-LR exposure; these biomarkers were considered responsible for MC-LR induced islet dysfunction. This study suggests that subchronic exposure to environmental levels of MCs may increase the risk of the occurrence of diabetes in humans.

  18. Distribution of Pancreatic Polypeptide-secreting Endocrine Cells in Nondiabetic and Diabetic Cases.

    Science.gov (United States)

    Śliwińska-Mossoń, Mariola; Milnerowicz, Halina

    2017-07-01

    The aim of the study was to demonstrate the effects of cigarette smoking and ongoing inflammation in chronic pancreatitis on the functioning of pancreatic polypeptide (PP)-secreting cells and to determine the relationship between the occurrence of an increased number of PP cells in the pancreas, the change in their location, and the intensity of their inflammatory changes in the course of pancreatitis and diabetes. Samples of tissues from healthy persons and from patients were verified histopathologically, and then PP was localized by immunohistochemical staining using the monoclonal anti-human PP antibody. The histopathologic evaluation of the hormone expression intensity in tissue sections was carried out using the semiquantitative method and was calculated with digital image analysis. The present study showed a very strong PP expression in the pancreatic tissue (especially in the head of the pancreas) derived from smoking patients with diabetes. The increase in the percentage of cells in the PP islets, between the acinar cells in smoking patients with diabetes and a statistically significant increase in the expression of PP, indicates a pancreatic endocrine dysfunction and suggests that cigarette smoking has a negative impact on the organ's efficiency. Because of its properties, the PP appears to be a useful marker of the endocrine insufficiency of the pancreas and a specific prognostic parameter of developing diabetes due to chronic pancreatitis.

  19. Islet cytotoxicity of interleukin 1. Influence of culture conditions and islet donor characteristics

    DEFF Research Database (Denmark)

    Mandrup-Poulsen, T; Spinas, G A; Prowse, S J

    1987-01-01

    We recently demonstrated that the macrophage product interleukin 1 (IL-1) is cytotoxic to isolated pancreatic islets and hypothesized that IL-1 is responsible for beta-cell destruction in insulin-dependent diabetes mellitus (IDDM). We studied whether the variation in IDDM preponderance with age, ...

  20. Dual role of interleukin-1β in islet amyloid formation and its β-cell toxicity: Implications for type 2 diabetes and islet transplantation.

    Science.gov (United States)

    Park, Yoo Jin; Warnock, Garth L; Ao, Ziliang; Safikhan, Nooshin; Meloche, Mark; Asadi, Ali; Kieffer, Timothy J; Marzban, Lucy

    2017-05-01

    Islet amyloid, formed by aggregation of human islet amyloid polypeptide (hIAPP), contributes to β-cell failure in type 2 diabetes, cultured and transplanted islets. We previously showed that biosynthetic hIAPP aggregates induce β-cell Fas upregulation and activation of the Fas apoptotic pathway. We used cultured human and hIAPP-expressing mouse islets to investigate: (1) the role of interleukin-1β (IL-1β) in amyloid-induced Fas upregulation; and (2) the effects of IL-1β-induced β-cell dysfunction on pro-islet amyloid polypeptide (proIAPP) processing and amyloid formation. Human and h IAPP -expressing mouse islets were cultured to form amyloid without or with the IL-1 receptor antagonist (IL-1Ra) anakinra, in the presence or absence of recombinant IL-1β. Human islets in which amyloid formation was prevented (amyloid inhibitor or Ad-prohIAPP-siRNA) were cultured similarly. β-cell function, apoptosis, Fas expression, caspase-8 activation, islet IL-1β, β-cell area, β-/α-cell ratio, amyloid formation, and (pro)IAPP forms were assessed. hIAPP aggregates were found to increase IL-1β levels in cultured human islets that correlated with β-cell Fas upregulation, caspase-8 activation and apoptosis, all of which were reduced by IL-1Ra treatment or prevention of amyloid formation. Moreover, IL-1Ra improved culture-induced β-cell dysfunction and restored impaired proIAPP processing, leading to lower amyloid formation. IL-1β treatment potentiated impaired proIAPP processing and increased amyloid formation in cultured human and h IAPP -expressing mouse islets, which were prevented by IL-1Ra. IL-1β plays a dual role by: (1) mediating amyloid-induced Fas upregulation and β-cell apoptosis; (2) inducing impaired proIAPP processing thereby potentiating amyloid formation. Blocking IL-1β may provide a new strategy to preserve β cells in conditions associated with islet amyloid formation. © 2017 John Wiley & Sons Ltd.

  1. Serum deprivation induces glucose response and intercellular coupling in human pancreatic adenocarcinoma PANC-1 cells.

    Science.gov (United States)

    Hiram-Bab, Sahar; Shapira, Yuval; Gershengorn, Marvin C; Oron, Yoram

    2012-03-01

    This study aimed to investigate whether the previously described differentiating islet-like aggregates of human pancreatic adenocarcinoma cells (PANC-1) develop glucose response and exhibit intercellular communication. Fura 2-loaded PANC-1 cells in serum-free medium were assayed for changes in cytosolic free calcium ([Ca]i) induced by depolarization, tolbutamide inhibition of K(ATP) channels, or glucose. Dye transfer, assayed by confocal microscopy or by FACS, was used to detect intercellular communication. Changes in messenger RNA (mRNA) expression of genes of interest were assessed by quantitative real-time polymerase chain reaction. Proliferation was assayed by the MTT method. Serum-deprived PANC-1 cell aggregates developed [Ca]i response to KCl, tolbutamide, or glucose. These responses were accompanied by 5-fold increase in glucokinase mRNA level and, to a lesser extent, of mRNAs for K(ATP) and L-type calcium channels, as well as increase in mRNA levels of glucagon and somatostatin. Trypsin, a proteinase-activated receptor 2 agonist previously shown to enhance aggregation, modestly improved [Ca]i response to glucose. Glucose-induced coordinated [Ca]i oscillations and dye transfer demonstrated the emergence of intercellular communication. These findings suggest that PANC-1 cells, a pancreatic adenocarcinoma cell line, can be induced to express a differentiated phenotype in which cells exhibit response to glucose and form a functional syncytium similar to those observed in pancreatic islets.

  2. Activation of transmembrane bile acid receptor TGR5 stimulates insulin secretion in pancreatic β cells

    International Nuclear Information System (INIS)

    Kumar, Divya P.; Rajagopal, Senthilkumar; Mahavadi, Sunila; Mirshahi, Faridoddin; Grider, John R.; Murthy, Karnam S.; Sanyal, Arun J.

    2012-01-01

    Highlights: ► G protein coupled receptor TGR5 is expressed in mouse and human islets. ► TGR5 is coupled to activation of Gs and Ca 2+ release via cAMP/Epac/PLC-ε pathway. ► Activation of TGR5 by bile salts and selective ligands causes insulin secretion. ► TGR5 could be a potential therapeutic target to treat diabetes. -- Abstract: Bile acids act as signaling molecules and stimulate the G protein coupled receptor, TGR5, in addition to nuclear farnesoid X receptor to regulate lipid, glucose and energy metabolism. Bile acid induced activation of TGR5 in the enteroendocrine cells promotes glucagon like peptide-1 (GLP-1) release, which has insulinotropic effect in the pancreatic β cells. In the present study, we have identified the expression of TGR5 in pancreatic β cell line MIN6 and also in mouse and human pancreatic islets. TGR5 selective ligands, oleanolic acid (OA) and INT-777 selectively activated Gα s and caused an increase in intracellular cAMP and Ca 2+ . OA and INT-777 also increased phosphoinositide (PI) hydrolysis and the increase was blocked by NF449 (a selective Gα s inhibitor) or (U73122) (PI hydrolysis inhibitor). OA, INT-777 and lithocholic acid increased insulin release in MIN6 and human islets and the increase was inhibited by treatment with NF449, (U73122) or BAPTA-AM (chelator of calcium), but not with myristoylated PKI (PKA inhibitor), suggesting that the release is dependent on G s /cAMP/Ca 2+ pathway. 8-pCPT-2′-O-Me-cAMP, a cAMP analog, which activates Epac, but not PKA also stimulated PI hydrolysis. In conclusion, our study demonstrates that the TGR5 expressed in the pancreatic β cells regulates insulin secretion and highlights the importance of ongoing therapeutic strategies targeting TGR5 in the control of glucose homeostasis.

  3. Exosomes Derived From Pancreatic Stellate Cells: MicroRNA Signature and Effects on Pancreatic Cancer Cells.

    Science.gov (United States)

    Takikawa, Tetsuya; Masamune, Atsushi; Yoshida, Naoki; Hamada, Shin; Kogure, Takayuki; Shimosegawa, Tooru

    2017-01-01

    Pancreatic stellate cells (PSCs) interact with pancreatic cancer cells in the tumor microenvironment. Cell constituents including microRNAs may be exported from cells within membranous nanovesicles termed exosomes. Exosomes might play a pivotal role in intercellular communication. This study aimed to clarify the microRNA signature of PSC-derived exosomes and their effects on pancreatic cancer cells. Exosomes were prepared from the conditioned medium of immortalized human PSCs. MicroRNAs were prepared from the exosomes and their source PSCs, and the microRNA expression profiles were compared by microarray. The effects of PSC-derived exosomes on proliferation, migration, and the mRNA expression profiles were examined in pancreatic cancer cells. Pancreatic stellate cell-derived exosomes contained a variety of microRNAs including miR-21-5p. Several microRNAs such as miR-451a were enriched in exosomes compared to their source PSCs. Pancreatic stellate cell-derived exosomes stimulated the proliferation, migration and expression of mRNAs for chemokine (C - X - C motif) ligands 1 and 2 in pancreatic cancer cells. The stimulation of proliferation, migration, and chemokine gene expression by the conditioned medium of PSCs was suppressed by GW4869, an exosome inhibitor. We clarified the microRNA expression profile in PSC-derived exosomes. Pancreatic stellate cell-derived exosomes might play a role in the interactions between PSCs and pancreatic cancer cells.

  4. Hair Follicle Dermal Sheath Derived Cells Improve Islet Allograft Survival without Systemic Immunosuppression

    Directory of Open Access Journals (Sweden)

    Xiaojie Wang

    2015-01-01

    Full Text Available Immunosuppressive drugs successfully prevent rejection of islet allografts in the treatment of type I diabetes. However, the drugs also suppress systemic immunity increasing the risk of opportunistic infection and cancer development in allograft recipients. In this study, we investigated a new treatment for autoimmune diabetes using naturally immune privileged, hair follicle derived, autologous cells to provide localized immune protection of islet allotransplants. Islets from Balb/c mouse donors were cotransplanted with syngeneic hair follicle dermal sheath cup cells (DSCC, group 1 or fibroblasts (FB, group 2 under the kidney capsule of immune-competent, streptozotocin induced, diabetic C57BL/6 recipients. Group 1 allografts survived significantly longer than group 2 (32.2 ± 12.2 versus 14.1 ± 3.3 days, P<0.001 without administration of any systemic immunosuppressive agents. DSCC reduced T cell activation in the renal lymph node, prevented graft infiltrates, modulated inflammatory chemokine and cytokine profiles, and preserved better beta cell function in the islet allografts, but no systemic immunosuppression was observed. In summary, DSCC prolong islet allograft survival without systemic immunosuppression by local modulation of alloimmune responses, enhancing of beta cell survival, and promoting of graft revascularization. This novel finding demonstrates the capacity of easily accessible hair follicle cells to be used as local immunosuppression agents in islet transplantation.

  5. Generation of Novel Single-Chain Antibodies by Phage-Display Technology to Direct Imaging Agents Highly Selective to Pancreatic β- or α-Cells In Vivo

    Science.gov (United States)

    Ueberberg, Sandra; Meier, Juris J.; Waengler, Carmen; Schechinger, Wolfgang; Dietrich, Johannes W.; Tannapfel, Andrea; Schmitz, Inge; Schirrmacher, Ralf; Köller, Manfred; Klein, Harald H.; Schneider, Stephan

    2009-01-01

    OBJECTIVE Noninvasive determination of pancreatic β-cell mass in vivo has been hampered by the lack of suitable β-cell–specific imaging agents. This report outlines an approach for the development of novel ligands homing selectively to islet cells in vivo. RESEARCH DESIGN AND METHODS To generate agents specifically binding to pancreatic islets, a phage library was screened for single-chain antibodies (SCAs) on rat islets using two different approaches. 1) The library was injected into rats in vivo, and islets were isolated after a circulation time of 5 min. 2) Pancreatic islets were directly isolated, and the library was panned in the islets in vitro. Subsequently, the identified SCAs were extensively characterized in vitro and in vivo. RESULTS We report the generation of SCAs that bind highly selective to either β- or α-cells. These SCAs are internalized by target cells, disappear rapidly from the vasculature, and exert no toxicity in vivo. Specific binding to β- or α-cells was detected in cell lines in vitro, in rats in vivo, and in human tissue in situ. Electron microscopy demonstrated binding of SCAs to the endoplasmatic reticulum and the secretory granules. Finally, in a biodistribution study the labeling intensity derived from [125I]-labeled SCAs after intravenous administration in rats strongly predicted the β-cell mass and was inversely related to the glucose excursions during an intraperitoneal glucose tolerance test. CONCLUSIONS Our data provide strong evidence that the presented SCAs are highly specific for pancreatic β-cells and enable imaging and quantification in vivo. PMID:19592622

  6. In vitro expansion and differentiation of rat pancreatic duct-derived stem cells into insulin secreting cells using a dynamicthree-dimensional cell culture system.

    Science.gov (United States)

    Chen, X C; Liu, H; Li, H; Cheng, Y; Yang, L; Liu, Y F

    2016-06-27

    In this study, a dynamic three-dimensional cell culture technology was used to expand and differentiate rat pancreatic duct-derived stem cells (PDSCs) into islet-like cell clusters that can secrete insulin. PDSCs were isolated from rat pancreatic tissues by in situ collagenase digestion and density gradient centrifugation. Using a dynamic three-dimensional culture technique, the cells were expanded and differentiated into functional islet-like cell clusters, which were characterized by morphological and phenotype analyses. After maintaining 1 x 108 isolated rat PDSCs in a dynamic three-dimensional cell culture for 7 days, 1.5 x 109 cells could be harvested. Passaged PDSCs expressed markers of pancreatic endocrine progenitors, including CD29 (86.17%), CD73 (90.73%), CD90 (84.13%), CD105 (78.28%), and Pdx-1. Following 14 additional days of culture in serum-free medium with nicotinamide, keratinocyte growth factor (KGF), and b fibroblast growth factor (FGF), the cells were differentiated into islet-like cell clusters (ICCs). The ICC morphology reflected that of fused cell clusters. During the late stage of differentiation, representative clusters were non-adherent and expressed insulin indicated by dithizone (DTZ)-positive staining. Insulin was detected in the extracellular fluid and cytoplasm of ICCs after 14 days of differentiation. Additionally, insulin levels were significantly higher at this time compared with the levels exhibited by PDSCs before differentiation (P cell culture system, PDSCs can be expanded in vitro and can differentiate into functional islet-like cell clusters.

  7. Pancreatic stellate cells promote epithelial-mesenchymal transition in pancreatic cancer cells

    International Nuclear Information System (INIS)

    Kikuta, Kazuhiro; Masamune, Atsushi; Watanabe, Takashi; Ariga, Hiroyuki; Itoh, Hiromichi; Hamada, Shin; Satoh, Kennichi; Egawa, Shinichi; Unno, Michiaki; Shimosegawa, Tooru

    2010-01-01

    Research highlights: → Recent studies have shown that pancreatic stellate cells (PSCs) promote the progression of pancreatic cancer. → Pancreatic cancer cells co-cultured with PSCs showed loose cell contacts and scattered, fibroblast-like appearance. → PSCs decreased the expression of epithelial markers but increased that of mesenchymal markers, along with increased migration. → This study suggests epithelial-mesenchymal transition as a novel mechanism by which PSCs contribute to the aggressive behavior of pancreatic cancer cells. -- Abstract: The interaction between pancreatic cancer cells and pancreatic stellate cells (PSCs), a major profibrogenic cell type in the pancreas, is receiving increasing attention. There is accumulating evidence that PSCs promote the progression of pancreatic cancer by increasing cancer cell proliferation and invasion as well as by protecting them from radiation- and gemcitabine-induced apoptosis. Because epithelial-mesenchymal transition (EMT) plays a critical role in the progression of pancreatic cancer, we hypothesized that PSCs promote EMT in pancreatic cancer cells. Panc-1 and SUIT-2 pancreatic cancer cells were indirectly co-cultured with human PSCs isolated from patients undergoing operation for pancreatic cancer. The expression of epithelial and mesenchymal markers was examined by real-time PCR and immunofluorescent staining. The migration of pancreatic cancer cells was examined by scratch and two-chamber assays. Pancreatic cancer cells co-cultured with PSCs showed loose cell contacts and a scattered, fibroblast-like appearance. The expression of E-cadherin, cytokeratin 19, and membrane-associated β-catenin was decreased, whereas vimentin and Snail (Snai-1) expression was increased more in cancer cells co-cultured with PSCs than in mono-cultured cells. The migration of pancreatic cancer cells was increased by co-culture with PSCs. The PSC-induced decrease of E-cadherin expression was not altered by treatment with anti

  8. SAD-A kinase controls islet β-cell size and function as a mediator of mTORC1 signaling.

    Science.gov (United States)

    Nie, Jia; Liu, Xiaolei; Lilley, Brendan N; Zhang, Hai; Pan, Y Albert; Kimball, Scot R; Zhang, Jun; Zhang, Weiping; Wang, Li; Jefferson, Leonard S; Sanes, Joshua R; Han, Xiao; Shi, Yuguang

    2013-08-20

    The mammalian target of rapamycin (mTOR) plays an important role in controlling islet β-cell function. However, the underlying molecular mechanisms remain poorly elucidated. Synapses of amphids defective kinase-A (SAD-A) is a 5' adenosine monophosphate-activated protein kinase-related protein kinase that is exclusively expressed in pancreas and brain. In this study, we investigated a role of the kinase in regulating pancreatic β-cell morphology and function as a mediator of mTOR complex 1 (mTORC1) signaling. We show that global SAD-A deletion leads to defective glucose-stimulated insulin secretion and petite islets, which are reminiscent of the defects in mice with global deletion of ribosomal protein S6 kinase 1, a downstream target of mTORC1. Consistent with these findings, selective deletion of SAD-A in pancreas decreased islet β-cell size, whereas SAD-A overexpression significantly increased the size of mouse insulinomas cell lines β-cells. In direct support of SAD-A as a unique mediator of mTORC1 signaling in islet β-cells, we demonstrate that glucose dramatically stimulated SAD-A protein translation in isolated mouse islets, which was potently inhibited by rapamycin, an inhibitor of mTORC1. Moreover, the 5'-untranslated region of SAD-A mRNA is highly structured and requires mTORC1 signaling for its translation initiation. Together, these findings identified SAD-A as a unique pancreas-specific effector protein of mTORC1 signaling.

  9. Pancreatic Beta-Cell Purification by Altering FAD and NAD(PH Metabolism

    Directory of Open Access Journals (Sweden)

    P. de Vos

    2008-07-01

    Full Text Available Isolation of primary beta cells from other cells within in the pancreatic islets is of importance for many fields of islet research. However, up to now, no satisfactory method has been developed that gained high numbers of viable beta cells, without considerable alpha-cell contamination. In this study, we investigated whether rat beta cells can be isolated from nonbeta endocrine cells by manipulating the flavin adenine dinucleotide (FAD and nicotinamide-adenine dinucleotide phosphate (NAD(PH autofluorescence. Beta cells were isolated from dispersed islets by flow cytometry, based on their high FAD and NAD(PH fluorescence. To improve beta cell yield and purity, the cellular FAD and NAD(PH contents were altered by preincubation in culture media containing varying amounts of D-glucose and amino acids. Manipulation of the cellular FAD and NAD(PH fluorescence improves beta cell yield and purity after sorting. This method is also a fast and reliable method to measure beta cell functional viability. A conceivable application is assessing beta cell viability before transplantation.

  10. Neurotransmitters and Neuropeptides: New Players in the Control of Islet of Langerhans' Cell Mass and Function.

    Science.gov (United States)

    Di Cairano, Eliana S; Moretti, Stefania; Marciani, Paola; Sacchi, Vellea Franca; Castagna, Michela; Davalli, Alberto; Folli, Franco; Perego, Carla

    2016-04-01