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  1. Islet Cell Transplantation

    Science.gov (United States)

    ... the body use glucose for energy. Islet cell transplantation transfers cells from an organ donor into the ... to make and release insulin. Researchers hope islet transplantation will help people with type 1 diabetes live ...

  2. Current status of islet cell transplantation.

    Science.gov (United States)

    Ichii, Hirohito; Ricordi, Camillo

    2009-01-01

    Despite substantial advances in islet isolation methods and immunosuppressive protocol, pancreatic islet cell transplantation remains an experimental procedure currently limited to the most severe cases of type 1 diabetes mellitus. The objectives of this treatment are to prevent severe hypoglycemic episodes in patients with hypoglycemia unawareness and to achieve a more physiological metabolic control. Insulin independence and long term-graft function with improvement of quality of life have been obtained in several international islet transplant centers. However, experimental trials of islet transplantation clearly highlighted several obstacles that remain to be overcome before the procedure could be proposed to a much larger patient population. This review provides a brief historical perspective of islet transplantation, islet isolation techniques, the transplant procedure, immunosuppressive therapy, and outlines current challenges and future directions in clinical islet transplantation.

  3. What Are Islet Cells?

    Science.gov (United States)

    ... and address the challenge of foreign tissue rejection. Engineering a Safe Cell Supply The issue of safety ... stem cell (hPSc)-based therapies. To address this problem, DRI researchers set out to engineer hPSc with " ...

  4. What Are Islet Cells?

    Science.gov (United States)

    ... and address the challenge of foreign tissue rejection. Engineering a Safe Cell Supply The issue of safety ... Former Chairmen National Office/Florida Region Northeast Region Financial Management Contact Us Donate Stay Informed Sign Up ...

  5. Utility of Pit-1 Immunostaining in Distinguishing Pituitary Adenomas of Primitive Differentiation from Null Cell Adenomas.

    Science.gov (United States)

    Lee, Julieann C; Pekmezci, Melike; Lavezo, Jonathan L; Vogel, Hannes; Katznelson, Laurence; Fraenkel, Merav; Harsh, Griffith; Dulai, Mohanpal; Perry, Arie; Tihan, Tarik

    2017-10-09

    Pit-1 immunostaining is not routinely used in the characterization of pituitary adenomas, and its utility in distinguishing adenomas dedicated towards the lactotroph, somatotroph, and thyrotroph lineage from null cell adenomas warrants further evaluation. Pituitary adenomas that were negative for expression of a basic panel of hormonal markers (ACTH, prolactin, and growth hormone) were further evaluated for TSH, SF-1, and Pit-1 expression using a tissue microarray. Among the 147 identified pituitary adenomas that were negative for ACTH, prolactin, growth hormone, and TSH, expression of SF-1 was present in 68 cases (46%). Of the remaining 72 cases with sufficient tissue for further analysis, four were Pit-1 positive (6% of the adenomas negative for ACTH, prolactin, growth hormone, TSH, and SF-1); the remaining 68 were potentially null cell adenomas. Two of the Pit-1-positive adenomas displayed a paranuclear CAM 5.2 staining pattern suggestive of a sparsely granulated somatotroph adenoma; however, only one case contained fibrous bodies within a majority of the adenoma cells. Our data suggests that Pit-1 can be utilized as a second tier immunostain in cases of clinically non-functioning adenomas that are immunonegative for ACTH, prolactin, growth hormone, TSH, and SF-1 in order to further segregate rare cases of Pit-1-positive adenomas from null cell adenomas. Pit-1 immunostaining can recognize rare cases of sparsely granulated somatotroph adenomas that appear immunonegative for growth hormone, as well as rare cases of other Pit-1-positive adenomas that are negative for Pit-1 lineage hormones. Overall, pituitary adenomas of the Pit-1 lineage that do not produce prolactin, growth hormone, or TSH are rare, with only four cases identified in the current study.

  6. Human pancreatic islet progenitor cells demonstrate phenotypic ...

    Indian Academy of Sciences (India)

    Prakash

    exploring alternative sources of insulin-producing cells for cell based therapy in diabetes. Since in vitro culture of islet β-cells demonstrates loss in insulin (Beattie et al. 1999), several attempts have been made to identify stem / progenitor cells capable of differentiation into insulin-producing cells. Embryonic stem cells, which ...

  7. A case of synchronous hurthle cell adenoma of thyroid and para thyroid adenoma

    Directory of Open Access Journals (Sweden)

    Masoome Tohidi

    2015-04-01

    Full Text Available Synchronous hurthle cell adenoma of thyroid and para thyroid adenoma is very rare .Here we dicuss a 46 year old woman who presented with a thyroid nodule. Thyroid function test was normal but she had mild hypercalcemia. Fine needle aspiration of thyroid nodule was done that it was suspecious to follicular neoplasm or follicular variant of papillary thyroid cancer .Then the patient underwent thyroidectomy. In surgical specimen hurthle cell adenoma of thyroid and parathyroid adenoma was confirmed.Measurment of serum calcium is recommended in patients who are candidate for thyroid surgery.

  8. Clinical Allogeneic and Autologous Islet Cell Transplantation: Update

    Directory of Open Access Journals (Sweden)

    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.

  9. Human pancreatic islet progenitor cells demonstrate phenotypic ...

    Indian Academy of Sciences (India)

    2009-04-24

    Apr 24, 2009 ... Phenotypic plasticity is a phenomenon that describes the occurrence of 2 or more distinct phenotypes under diverse conditions. This article discusses the work carried out over the past few years in understanding the potential of human pancreatic islet-derived progenitors for cell replacement therapy in ...

  10. β-CELL SPECIFIC CYTOPROTECTION BY PROLACTIN ON HUMAN ISLETS

    Science.gov (United States)

    Yamamoto, Toshiyuki; Ricordi, Camillo; Mita, Atsuyoshi; Miki, Atsushi; Sakuma, Yasunaru; Damaris Molano, R.; Fornoni, Alessia; Pileggi, Antonello; Inverardi, Luca; Ichii, Hirohito

    2008-01-01

    Many cytoprotective agents have been reported to improve islet isolation and transplantation outcomes. However, several cytoprotective agents may improve all cell subsets within an islet preparation, and selected non- β-cells components may have a negative effect on β-cell function and survival (e.g., acinar cells). In this study, we examined the effect of prolactin (PRL) supplementation to the culture medium, to determine whether it could exert β-cell-selective cytoprotection (islet viability and function) towards a possible use of PRL during pre transplant islet culture. Materials and Methods Human islets pre-cultured or not with recombinant human PRL (500 μg/L) for 48 hours. Non-β-cells and β-cell-specific fractional viability and cellular composition were assessed by FACS and Laser Scanning Cytometry (LSC). Islet potency was assessed in vivo by transplantation into chemically-induced diabetic immunodeficient mice. Results The relative viable β-cell mass and the relative islet β-cell content in PRL group were 28% higher (p=0.018) and 19% higher (p=0.029) than control group, respectively. All transplanted mice achieved normoglycemia in both groups, indicating that PRL treatment did not alter islet function. Conclusions PRL treatment improves β-cell-specific viability and survival in human islets in vitro. The development of novel β-cell-specific cytoprotective strategies will be of assistance in improving islet transplantation. PMID:18374075

  11. Islet amyloid polypeptide and insulin expression are controlled differently in primary and transformed islet cells

    DEFF Research Database (Denmark)

    Madsen, O D; Michelsen, Bo Thomas; Westermark, P

    1991-01-01

    The pancreatic beta-cell is a major site of islet amyloid polypeptide (IAPP) biosynthesis, and the peptide is coreleased with insulin. We have analyzed the expression of IAPP (mRNA and protein) in various cell types in normal and transformed murine islet cell cultures by Northern blot analyses...... of these cells. IAPP mRNA was confined to the beta-cell phenotype when analyzing the phenotypically stable in vivo tumor lines, MSL-G2-IN (insulinoma) and MSL-G-AN (glucagonoma), and the transgenic mouse islet cell lines, beta-Tc and alpha-Tc. However, IAPP and insulin expression were completely uncoupled...... and immunocytochemistry. IAPP is primarily coexpressed with insulin in the beta-cell of GH-promoted primary rat islet cell cultures. Additionally, a small population of non-beta-cells exhibited a prominent IAPP expression, and double staining experiments showed colocalization with glucagon or somatostatin in some...

  12. CT features of nonfunctioning islet cell carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    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.

  13. Lineage-Specific Restraint of Pituitary Gonadotroph Cell Adenoma Growth

    Science.gov (United States)

    Chesnokova, Vera; Zonis, Svetlana; Zhou, Cuiqi; Ben-Shlomo, Anat; Wawrowsky, Kolja; Toledano, Yoel; Tong, Yunguang; Kovacs, Kalman; Scheithauer, Bernd; Melmed, Shlomo

    2011-01-01

    Although pituitary adenomas are usually benign, unique trophic mechanisms restraining cell proliferation are unclear. As GH-secreting adenomas are associated with p53/p21-dependent senescence, we tested mechanisms constraining non-functioning pituitary adenoma growth. Thirty six gonadotroph-derived non-functioning pituitary adenomas all exhibited DNA damage, but undetectable p21 expression. However, these adenomas all expressed p16, and >90% abundantly expressed cytoplasmic clusterin associated with induction of the Cdk inhibitor p15 in 70% of gonadotroph and in 26% of somatotroph lineage adenomas (p = 0.006). Murine LβT2 and αT3 gonadotroph pituitary cells, and αGSU.PTTG transgenic mice with targeted gonadotroph cell adenomas also abundantly expressed clusterin and exhibited features of oncogene-induced senescence as evidenced by C/EBPβ and C/EBPδ induction. In turn, C/EBPs activated the clusterin promoter ∼5 fold, and elevated clusterin subsequently elicited p15 and p16 expression, acting to arrest murine gonadotroph cell proliferation. In contrast, specific clusterin suppression by RNAis enhanced gonadotroph proliferation. FOXL2, a tissue-specific gonadotroph lineage factor, also induced the clusterin promoter ∼3 fold in αT3 pituitary cells. As nine of 12 pituitary carcinomas were devoid of clusterin expression, this protein may limit proliferation of benign adenomatous pituitary cells. These results point to lineage-specific pathways restricting uncontrolled murine and human pituitary gonadotroph adenoma cell growth. PMID:21464964

  14. Controlled aggregation of primary human pancreatic islet cells leads to glucose-responsive pseudoislets comparable to native islets

    NARCIS (Netherlands)

    Hilderink, J.; Spijker, S.; Carlotti, F.; Lange, L.; Engelse, M.; van Blitterswijk, Clemens; de Koning, E.; Karperien, Hermanus Bernardus Johannes; van Apeldoorn, Aart A.

    2015-01-01

    Clinical islet transplantation is a promising treatment for patients with type 1 diabetes. However, pancreatic islets vary in size and shape affecting their survival and function after transplantation because of mass transport limitations. To reduce diffusion restrictions and improve islet cell

  15. Pancreas++ : Automated Quantification of Pancreatic Islet Cells in Microscopy Images

    Directory of Open Access Journals (Sweden)

    Hongyu eChen

    2013-01-01

    Full Text Available The microscopic image analysis of pancreatic Islet of Langerhans morphology is crucial for the investigation of diabetes and metabolic diseases. Besides the general size of the islet, the percentage and relative position of glucagon-containing alpha-, and insulin-containing beta-cells is also important for pathophysiological analyses, especially in rodents. Hence, the ability to identify, quantify and spatially locate peripheral and ‘involuted’ alpha-cells in the islet core is an important analytical goal. There is a dearth of software available for the automated and sophisticated positional-quantification of multiple cell types in the islet core. Manual analytical methods for these analyses, while relatively accurate, can suffer from a slow throughput rate as well as user-based biases. Here we describe a newly developed pancreatic islet analytical software program, Pancreas++, which facilitates the fully-automated, non-biased, and highly reproducible investigation of islet area and alpha- and beta-cell quantity as well as position within the islet for either single or large batches of fluorescent images. We demonstrate the utility and accuracy of Pancreas++ by comparing its performance to other pancreatic islet size and cell type (alpha, beta quantification methods. Our Pancreas++ analysis was significantly faster than other methods, while still retaining low error rates and a high degree of result correlation with the manually generated reference standard.

  16. 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

  17. 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

  18. Pancreatic islet cell reaggregation systems: efficiency of cell reassociation and endocrine cell topography of rat islet-like aggregates.

    Science.gov (United States)

    Matta, S G; Wobken, J D; Williams, F G; Bauer, G E

    1994-07-01

    Single cells isolated from rat islets of Langerhans were cultured under conditions that support reassociation into islet-like aggregates. Comparisons were made of enzymatic methods of islet dissociation, rotational or static culture conditions, and culture at basal or stimulatory glucose concentrations. Over a period of 4 days the aggregates progressed through three stages of organization: cell coalescence to cellular chains, rearrangement of chains into small spheroids, and growth of spheroids. The numerical yield of aggregates was optimum after islets were dissociated with dispase. Culture under rotation resulted in the production of more aggregates of significantly larger diameter than under static conditions. Medium glucose concentrations of 4 and 11 mM supported cell reassociation under rotator culture, but no aggregation occurred under static culture at the basal (4 mM) glucose level. Aggregates resulting from 4-day rotator culture exhibited endocrine cell distributions similar to intact islets. Islet aggregates released insulin in response to glucose, but nonaggregated cells, maintained in culture, did not. The present comparisons reveal significant variability in the cellular composition, rate of formation, and yield of aggregates, and suggest that the methodology for producing aggregates should be carefully considered in experimental design.

  19. Connexin 36 mediates blood cell flow in mouse pancreatic islets.

    Science.gov (United States)

    Short, Kurt W; Head, W Steve; Piston, David W

    2014-02-01

    The insulin-secreting β-cells are contained within islets of Langerhans, which are highly vascularized. Blood cell flow rates through islets are glucose-dependent, even though there are no changes in blood cell flow within in the surrounding exocrine pancreas. This suggests a specific mechanism of glucose-regulated blood flow in the islet. Pancreatic islets respond to elevated glucose with synchronous pulses of electrical activity and insulin secretion across all β-cells in the islet. Connexin 36 (Cx36) gap junctions between islet β-cells mediate this synchronization, which is lost in Cx36 knockout mice (Cx36(-/-)). This leads to glucose intolerance in these mice, despite normal plasma insulin levels and insulin sensitivity. Thus, we sought to investigate whether the glucose-dependent changes in intraislet blood cell flow are also dependent on coordinated pulsatile electrical activity. We visualized and quantified blood cell flow using high-speed in vivo fluorescence imaging of labeled red blood cells and plasma. With the use of a live animal glucose clamp, blood cell flow was measured during either hypoglycemia (∼50 mg/dl) or hyperglycemia (∼300 mg/dl). In contrast to the large glucose-dependent islet blood velocity changes observed in wild-type mice, only minimal differences are observed in both Cx36(+/-) and Cx36(-/-) mice. This observation supports a novel model where intraislet blood cell flow is regulated by the coordinated electrical activity in the islet β-cells. Because Cx36 expression and function is reduced in type 2 diabetes, the resulting defect in intraislet blood cell flow regulation may also play a significant role in diabetic pathology.

  20. 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....

  1. Multipotent mesenchymal stromal cells enhance insulin secretion from human islets via N-cadherin interaction and prolong function of transplanted encapsulated islets in mice

    OpenAIRE

    Montanari, Elisa; Meier, Raphael P. H.; Mahou, Redouan; Seebach, Jörg D.; Wandrey, Christine; Gerber-Lemaire, Sandrine; Buhler, Leo H.; Gonelle-Gispert, Carmen

    2017-01-01

    Background Multipotent mesenchymal stromal cells (MSC) enhance viability and function of islets of Langerhans. We aimed to examine the interactions between human MSC and human islets of Langerhans that influence the function of islets. Methods Human MSC and human islets (or pseudoislets, obtained after digestion and reaggregation of islet cells) were cocultured with or without cellular contact and glucose-stimulated insulin secretion assays were performed to assess cell function. The expressi...

  2. Characterization of pancreatic ductal cells in human islet preparations.

    Science.gov (United States)

    Ichii, Hirohito; Miki, Atsushi; Yamamoto, Toshiyuki; Molano, Ruth D; Barker, Scott; Mita, Atsuyoshi; Rodriguez-Diaz, Rayner; Klein, Dagmar; Pastori, Ricardo; Alejandro, Rodolfo; Inverardi, Luca; Pileggi, Antonello; Ricordi, Camillo

    2008-11-01

    Substantial amounts of nonendocrine cells are implanted as part of human islet grafts, and a possible influence of nonendocrine cells on clinical islet transplantation outcome has been postulated. There are currently no product release criteria specific for nonendocrine cells due to lack of available methods. The aims of this study were to develop a method for the evaluation of pancreatic ductal cells (PDCs) for clinical islet transplantation and to characterize them regarding phenotype, viability, and function. We assessed 161 human islet preparations using laser scanning cytometry (LSC/iCys) for phenotypic analysis of nonendocrine cells and flow cytometry (FACS) for PDC viability. PDC and beta-cells obtained from different density fractions during the islet cell purification were compared in terms of viability. Furthermore, we examined PDC ability to produce proinflammatory cytokines/chemokines, vascular endothelial growth factor (VEGF) and tissue factor (TF) relevant to islet graft outcome. Phenotypic analysis by LSC/iCys indicated that single staining for CK19 or CA19-9 was not enough for identifying PDCs, and that double staining for amylase and CK19 or CA19-9 allowed for quantitative evaluation of acinar cells and PDC content in human islet preparation. PDC showed a significantly higher viability than beta-cells (PDC vs beta-cell: 75.5+/-13.9 and 62.7+/-18.7%; P<0.0001). Although beta-cell viability was independent of its density, that of PDCs was higher as the density from which they were recovered increased. There was no correlation between PDCs and beta-cell viability (R(2)=0.0078). PDCs sorted from high-density fractions produced significantly higher amounts of proinflammatory mediators and VEGF, but not TF. We conclude that PDCs isolated from different fractions had different viability and functions. The precise characterization and assessment of these cells in addition to beta-cells in human islet cell products may be of assistance in understanding

  3. Induction of insulin and islet amyloid polypeptide production in pancreatic islet glucagonoma cells by insulin promoter factor 1

    DEFF Research Database (Denmark)

    Serup, P; Jensen, J; Andersen, F G

    1996-01-01

    ) 371, 606-609]. In adults, IPF1 expression is restricted to the beta-cells in the islets of Langerhans. We report here that IPF1 induces expression of a subset of beta-cell-specific genes (insulin and islet amyloid polypeptide) when ectopically expressed in clones of transformed pancreatic islet alpha...... in both alpha- and beta-cells. We conclude that IPF1 is a potent transcriptional activator of endogenous insulin genes in non-beta islet cells, which suggests an important role of IPF1 in beta-cell maturation.......-cells. In contrast, expression of IPF1 in rat embryo fibroblasts factor failed to induce insulin and islet amyloid polypeptide expression. This is most likely due to the lack of at least one other essential insulin gene transcription factor, the basic helix-loop-helix protein Beta 2/NeuroD, which is expressed...

  4. Quantitative assessment of islet cell products: estimating the accuracy of the existing protocol and accounting for islet size distribution.

    Science.gov (United States)

    Buchwald, Peter; Wang, Xiaojing; Khan, Aisha; Bernal, Andres; Fraker, Chris; Inverardi, Luca; Ricordi, Camillo

    2009-01-01

    The ability to consistently and reliably assess the total number and the size distribution of isolated pancreatic islet cells from a small sample is of crucial relevance for the adequate characterization of islet cell preparations used for research or transplantation purposes. Here, data from a large number of isolations were used to establish a continuous probability density function describing the size distribution of human pancreatic islets. This function was then used to generate a polymeric microsphere mixture with a composition resembling those of isolated islets, which, in turn, was used to quantitatively assess the accuracy, reliability, and operator-dependent variability of the currently utilized manual standard procedure of quantification of islet cell preparation. Furthermore, on the basis of the best fit probability density function, which corresponds to a Weibull distribution, a slightly modified scale of islet equivalent number (IEQ) conversion factors is proposed that incorporates the size distribution of islets and accounts for the decreasing probability of finding larger islets within each size group. Compared to the current calculation method, these factors introduce a 4-8% downward correction of the total IEQ estimate, but they reflect a statistically more accurate contribution of differently sized islets.

  5. Hepatic Cell Adenoma: A Report of Four Cases

    Science.gov (United States)

    Albritton, David R.; Tompkins, Ronald K.; Longmire, William P.

    1974-01-01

    Four patients with hepatic cell adenoma have been treated at the UCLA Hospital since 1965. The most recent was a 22-year-old woman who underwent subtotal resection of a giant hepatic cell adenoma after an unusual and confusing clinical presentation. The tumor may be the largest reported to date and may have excreted metabolically-active substances. Increased familiarity with the varying clinical and radiographic presentations of these rare tumors may facilitate earlier diagnosis and management. ImagesFig. 1.Fig. 2.Fig. 3.Fig. 6.Fig. 7. PMID:4366047

  6. Semiquantitative determination of circulating islet cell surface antibodies in diabetes

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    Ohgawara, Hisako; Machiyama, Etsuko; Hirata, Yukimasa (Tokyo Women' s Medical Coll. (Japan))

    1982-09-01

    Circulating pancreatic islet cell antibodies have been demonstrated in patients with insulin-dependent diabetes (IDD). The islet cell surface antibodies (ICSA) were determined by an indirect immunofluorescence test using a suspension of viable islet cells, and similar cytoplasmic antibodies which require the use of group O human pancreas were also found in the serum of some patients. A strong association exists between the presence of islet cell antibodies and the onset of insulin-dependent diabetes. The quantitative determination of circulating ICSA using /sup 125/I-protein A, which binds to IgG attached to the islet cell surface, was essentially as described by Lernmark et al. In the present study, we determined the circulating ICSA in diabetes, especially in IDD. The ICSA were estimated in various sera from both indirect immunofluorescence and /sup 125/I-protein A. Controls bound <2,000 cpm /sup 125/I-protein A. Sera from 4 IDD patients with circulating ICSA demonstrated by immunofluorescence showed >3,000 cpm /sup 125/I-protein A binding activity, and that from 5 patients without ICSA bound <2,000 cpm. Sera from newly-diagnosed diabetics who had severe hyperglycemia showed <2,000 cpm, with or without ICSA.

  7. Immunocytochemical Identification of Four Cell Types in the Pancreatic Islets of the Japanese Serow, Capricornis crispus : COMMUNICATION : Morphology

    OpenAIRE

    YASURO, ATOJI; YASUAKI, TAKADA; YOSHITAKA, SUZUKI; Makoto, Sugimura; Department of Veterinary Anatomy, Faculty of Agriculture, Gifu University; Department of Veterinary Anatomy, Faculty of Veterinary Medicine, Hokkaido University

    1990-01-01

    The pancreatic islet of the Japanese serow was immunocytochemically examined. The islets were classified into large and small types, and both types of islets showed a similar composition of endocrine cells. The B cells were prominent and located at the periphery or throughout the islet . The A cells were less numerous and D and PP cells were sparse . The PP islets showing a majority of the PP cells were sometimes found. The large and small islets were detected irrespective of age of animals. ...

  8. 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.

  9. Characterization of islet cells during development and after transplantation

    NARCIS (Netherlands)

    van Gurp, Léon

    2017-01-01

    Diabetes Mellitus is a disease in which patients are not able to maintain blood glucose levels. This is caused by dysfunction or destruction of the beta cells in the islets of Langerhans, located in the pancreas. Beta cells are responsible for the production of insulin, a hormone that decreases the

  10. Fully Automated Islet Cell Counter (ICC) for the Assessment of Islet Mass, Purity, and Size Distribution by Digital Image Analysis.

    Science.gov (United States)

    Buchwald, Peter; Bernal, Andres; Echeverri, Felipe; Tamayo-Garcia, Alejandro; Linetsky, Elina; Ricordi, Camillo

    2016-10-01

    For isolated pancreatic islet cell preparations, it is important to be able to reliably assess their mass and quality, and for clinical applications, it is part of the regulatory requirement. Accurate assessment, however, is difficult because islets are spheroid-like cell aggregates of different sizes (<50 to 500 μm) resulting in possible thousandfold differences between the mass contribution of individual particles. The current standard manual counting method that uses size-based group classification is known to be error prone and operator dependent. Digital image analysis (DIA)-based methods can provide less subjective, more reproducible, and better-documented islet cell mass (IEQ) estimates; however, so far, none has become widely accepted or used. Here we present results obtained using a compact, self-contained islet cell counter (ICC3) that includes both the hardware and software needed for automated islet counting and requires minimal operator training and input; hence, it can be easily adapted at any center and could provide a convenient standardized cGMP-compliant IEQ assessment. Using cross-validated sample counting, we found that for most human islet cell preparations, ICC3 provides islet mass (IEQ) estimates that correlate well with those obtained by trained operators using the current manual SOP method ( r2 = 0.78, slope = 1.02). Variability and reproducibility are also improved compared to the manual method, and most of the remaining variability (CV = 8.9%) results from the rearrangement of the islet particles due to movement of the sample between counts. Characterization of the size distribution is also important, and the present digitally collected data allow more detailed analysis and coverage of a wider size range. We found again that for human islet cell preparations, a Weibull distribution function provides good description of the particle size.

  11. Fine Needle Aspiration Cytology of Basal Cell Adenoma of Parotid Simulating Adenoid Cystic Carcinoma.

    Science.gov (United States)

    Pal, Subrata; Mondal, Palash Kr; Sharma, Abhishek; Sikder, Mrinal

    2018-01-01

    Basal cell adenoma is a rare type of monomorphic salivary adenoma most commonly involving the parotid gland. Cytology of basal cell adenoma closely mimics many other benign and malignant basaloid neoplasms. Cytological features of membranous basal cell adenoma simulate adenoid cystic carcinoma in fine needle aspiration cytology (FNAC) smears. Here, we are presenting a rare case of cytodiagnosis of membranous basal cell adenoma of parotid gland in an elderly lady, which mimicked adenoid cystic carcinoma on FNAC. We discuss the cytomorphology of this rare case with an emphasis on cytological difference between membranous basal cell carcinoma and adenoid cystic carcinoma as well as other basaloid neoplasms.

  12. Islet Brain 1 Protects Insulin Producing Cells against Lipotoxicity

    OpenAIRE

    Saška Brajkovic; Mourad Ferdaoussi; Valérie Pawlowski; Hélène Ezanno; Valérie Plaisance; Erik Zmuda; Tsonwin Hai; Jean-Sébastien Annicotte; Gérard Waeber; Amar Abderrahmani

    2015-01-01

    Chronic intake of saturated free fatty acids is associated with diabetes and may contribute to the impairment of functional beta cell mass. Mitogen activated protein kinase 8 interacting protein 1 also called islet brain 1 (IB1) is a candidate gene for diabetes that is required for beta cell survival and glucose-induced insulin secretion (GSIS). In this study we investigated whether IB1 expression is required for preserving beta cell survival and function in response to palmitate. Chronic exp...

  13. Serum Cytokines as Biomarkers in Islet Cell Transplantation for Type 1 Diabetes

    NARCIS (Netherlands)

    van der Torren, Cornelis R; Verrijn Stuart, Annemarie A|info:eu-repo/dai/nl/304817589; Lee, DaHae; Meerding, Jenny; van de Velde, Ursule; Pipeleers, Daniel; Gillard, Pieter; Keymeulen, Bart; de Jager, Wilco|info:eu-repo/dai/nl/304816906; 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

  14. Characterization of islet cells during development and after transplantation

    OpenAIRE

    van Gurp, Léon

    2017-01-01

    Diabetes Mellitus is a disease in which patients are not able to maintain blood glucose levels. This is caused by dysfunction or destruction of the beta cells in the islets of Langerhans, located in the pancreas. Beta cells are responsible for the production of insulin, a hormone that decreases the amount of available glucose in the blood when it becomes too high. Therapeutically, diabetes patients inject themselves with insulin as an alternative, but this treatment is symptomatic. The only a...

  15. Pancreas and islet cell transplantation: now and then.

    Science.gov (United States)

    Sutherland, D E

    1996-08-01

    Pancreas transplantation currently can be offered with the same probability of success as other solid organ transplants. In diabetic uremic recipients of kidney transplants, the addition of a pancreas is routine in many centers. For selected patients with labile diabetes and hypoglycemia unawareness, a successful pancreas transplant can dramatically improve quality of life. Islet transplantation is an alternative to pancreas transplantation that can reduce surgical morbidity, but is much less successful at the moment. The theoretical, immunological advantages of islet transplantation have not yet been realized. Part of the problem lies in the reduced beta cell mass that occurs with organ dispersal and islet purification. Diabetogenic immunosuppressants need to be eliminated in order to allow optimal function of what is engrafted. The immunosuppressants (eg, mycophenolate mofetil, rapamycin) give this possibility. Whether islet transplantation will replace pancreas transplantation remains problematic. Ultimately, and neither should be needed for Type I diabetes, since autoimmune diseases should be preventable by appropriate manipulation of the immune system in those identified at risk. Our personal goals as transplanters should be obsolescence.

  16. 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

    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...

  17. Stem cell-derived islet cells for transplantation.

    Science.gov (United States)

    Domínguez-Bendala, Juan; Inverardi, Luca; Ricordi, Camillo

    2011-02-01

    The promise of islet transplantation for type 1 diabetes has been hampered by the lack of a renewable source of insulin-producing cells. However, steadfast advances in the field have set the stage for stem cell-based approaches to take over in the near future. This review focuses on the most intriguing findings reported in recent years, which include not only progress in adult and embryonic stem cell differentiation, but also the direct reprogramming of nonendocrine tissues into insulin-producing beta cells. In spite of their potential for tumorigenesis, human embryonic stem (hES) cells are poised to be in clinical trials within the next decade. This situation is mainly due to the preclinical success of a differentiation method that recapitulates beta cell development. In contrast, adult stem cells still need one such gold standard of differentiation, and progress is somewhat impeded by the lack of consensus on the best source. A concerted effort is necessary to bring their potential to clinical fruition. In the meantime, reported success in reprogramming might offer a 'third way' towards the rescue of pancreatic endocrine function. Here we discuss the important strategic decisions that need to be made in order to maximize the therapeutic chances of each of the presented approaches.

  18. Islet cell antibodies (ICA) identify autoimmunity in children with new onset diabetes mellitus negative for other islet cell antibodies.

    Science.gov (United States)

    Andersson, Cecilia; Kolmodin, Martin; Ivarsson, Sten-Anders; Carlsson, Annelie; Forsander, Gun; Lindblad, Bengt; Ludvigsson, Johnny; Kockum, Ingrid; Marcus, Claude; Samuelsson, Ulf; Ortqvist, Eva; Lernmark, Ake; Elding Larsson, Helena; Törn, Carina

    2014-08-01

    The aim of this study was to explore whether islet cell antibodies (ICA) could be identified in children with newly onset diabetes mellitus but negative for autoantibodies against glutamic acid decarboxylase (GADA), islet antigen-2 (IA-2A), insulin (IAA), or any of the three variants with arginine (R), tryptophan (W), or glutamine (Q) at position 325 of the zinc transporter 8 (ZnT8A). A population-based analysis of autoantibodies was performed from 1 May 2005 to 2 September 2010 in Swedish children newly diagnosed with diabetes. ICA was analyzed with an enzyme-linked immunosorbent assay and if positive, reanalyzed in the classical ICA immunofluorescence assay, in 341 samples among 3545 children who had been tested negative for all of GADA, IA-2A, IAA, or ZnT8A (R, W, Q). An isolated positivity for ICA was identified in 5.0% (17/341) of the newly diagnosed children. The levels of ICA in positive subjects ranged from 3 to 183 JDF-U (median 30). This finding increased the diagnostic sensitivity of islet autoimmunity as 3204/3545 patients (90.4%) were islet autoantibody positive without the ICA analyses and 3221 patients (90.9%) were positive with the inclusion of ICA. The finding of an isolated positivity for ICA despite negativity for GADA, IA-2A, IAA, and ZnT8A (R, W, Q) suggests that still another yet unidentified autoantigen(s) may contribute to the ICA immunofluorescence. Hence, ICA is important to analyze in type 1 diabetes children and adolescents that would otherwise be islet autoantibody negative. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. Mouse pancreatic islet macrophages use locally released ATP to monitor beta cell activity.

    Science.gov (United States)

    Weitz, Jonathan R; Makhmutova, Madina; Almaça, Joana; Stertmann, Julia; Aamodt, Kristie; Brissova, Marcela; Speier, Stephan; Rodriguez-Diaz, Rayner; Caicedo, Alejandro

    2017-09-07

    Tissue-resident macrophages sense the microenvironment and respond by producing signals that act locally to maintain a stable tissue state. It is now known that pancreatic islets contain their own unique resident macrophages, which have been shown to promote proliferation of the insulin-secreting beta cell. However, it is unclear how beta cells communicate with islet-resident macrophages. Here we hypothesised that islet macrophages sense changes in islet activity by detecting signals derived from beta cells. To investigate how islet-resident macrophages respond to cues from the microenvironment, we generated mice expressing a genetically encoded Ca(2+) indicator in myeloid cells. We produced living pancreatic slices from these mice and used them to monitor macrophage responses to stimulation of acinar, neural and endocrine cells. Islet-resident macrophages expressed functional purinergic receptors, making them exquisite sensors of interstitial ATP levels. Indeed, islet-resident macrophages responded selectively to ATP released locally from beta cells that were physiologically activated with high levels of glucose. Because ATP is co-released with insulin and is exclusively secreted by beta cells, the activation of purinergic receptors on resident macrophages facilitates their awareness of beta cell secretory activity. Our results indicate that islet macrophages detect ATP as a proxy signal for the activation state of beta cells. Sensing beta cell activity may allow macrophages to adjust the secretion of factors to promote a stable islet composition and size.

  20. Pituitary null cell adenoma in a domestic llama (Lama glama).

    Science.gov (United States)

    Chalkley, M D; Kiupel, M; Draper, A C E

    2014-07-01

    Pituitary gland neoplasia has been reported rarely in camelids. A 12-year-old neutered male llama (Lama glama) presented with lethargy, inappetence and neurological signs. On physical examination, the llama was mentally dull and exhibited compulsive pacing and circling to the left. Complete blood count and serum biochemistry revealed haemoconcentration, mild hypophosphataemia, hyperglycaemia, hypercreatininaemia and hyperalbuminaemia. Humane destruction was elected due to rapid clinical deterioration and poor prognosis. Post-mortem examination revealed a pituitary macroadenoma and bilateral internal hydrocephalus. Microscopically, the pituitary tumour was composed of neoplastic chromophobic pituitary cells. Ultrastructural studies revealed similar neoplastic cells to those previously described in human null cell adenomas. Immunohistochemically, the neoplastic cells were strongly immunoreactive for neuroendocrine markers (synaptophysin and chromogranin A), but did not exhibit immunoreactivity for epithelial, mesenchymal, neuronal and all major pituitary hormone markers (adrenocorticotropic hormone, follicle stimulating hormone, growth hormone, luteinizing hormone, melanocyte-stimulating hormone, prolactin and thyroid stimulating hormone), consistent with the diagnosis of a pituitary null cell adenoma. This is the first report of pituitary neoplasia in a llama. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Islet β–Cell Transcriptome and Integrated-omics

    Science.gov (United States)

    Blodgett, David M.; Cura, Anthony J.; Harlan, David M.

    2014-01-01

    Purpose of Review β cells represent one of many cell types in heterogeneous pancreatic islets and play the central role in maintaining glucose homeostasis, such that disrupting β cell function leads to diabetes. This review summarizes methods for isolating and characterizing β cells, and describes integrated “omics” approaches used to define the β cell by its transcriptome and proteome. Recent Findings RNA Sequencing and mass spectrometry-based protein identification have now identified RNA and protein profiles for mouse and human pancreatic islets and β cells, and for β cell lines. Recent publications have outlined these profiles and, more importantly, have begun to assign the presence or absence of specific genes and regulatory molecules to β cell function and dysfunction. Overall, researchers have focused on understanding the pathophysiology of diabetes by connecting genome, transcriptome, proteome, and regulatory RNA profiles with findings from genome wide association studies (GWAS). Summary Studies employing these relatively new techniques promise to identify specific genes or regulatory RNAs with altered expression as β cell function begins to deteriorate in the spiral toward the development of diabetes. The ultimate goal is to identify potential therapeutic targets to prevent β cell dysfunction and thereby better treat the individual with diabetes. PMID:24526012

  2. 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

    in a process where cell adhesion molecules are involved. In this study we have analyzed the expression of neural cell adhesion molecule (NCAM) and cadherin molecules in neonatal, young, and adult rat islet cells as well as in glucagonomas and insulinomas derived from a pluripotent rat islet cell tumor. Whereas...

  3. 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.

  4. Islet Brain 1 Protects Insulin Producing Cells against Lipotoxicity

    Directory of Open Access Journals (Sweden)

    Saška Brajkovic

    2016-01-01

    Full Text Available Chronic intake of saturated free fatty acids is associated with diabetes and may contribute to the impairment of functional beta cell mass. Mitogen activated protein kinase 8 interacting protein 1 also called islet brain 1 (IB1 is a candidate gene for diabetes that is required for beta cell survival and glucose-induced insulin secretion (GSIS. In this study we investigated whether IB1 expression is required for preserving beta cell survival and function in response to palmitate. Chronic exposure of MIN6 and isolated rat islets cells to palmitate led to reduction of the IB1 mRNA and protein content. Diminution of IB1 mRNA and protein level relied on the inducible cAMP early repressor activity and proteasome-mediated degradation, respectively. Suppression of IB1 level mimicked the harmful effects of palmitate on the beta cell survival and GSIS. Conversely, ectopic expression of IB1 counteracted the deleterious effects of palmitate on the beta cell survival and insulin secretion. These findings highlight the importance in preserving the IB1 content for protecting beta cell against lipotoxicity in diabetes.

  5. An imidazoline compound completely counteracts interleukin-1[beta] toxic effects to rat pancreatic islet [beta] cells

    DEFF Research Database (Denmark)

    Papaccio, Gianpaolo; Nicoletti, Ferdinando; Pisanti, Francesco A

    2002-01-01

    In vitro studies have demonstrated that interleukin (IL)-1beta decreases insulin and DNA contents in pancreatic islet beta cells, causing structural damage, that it is toxic to cultured human islet beta cells and that it is able to induce apoptosis in these cells....

  6. Immunohistochemical expression of MYB in salivary gland basal cell adenocarcinoma and basal cell adenoma.

    Science.gov (United States)

    Rooney, Sydney L; Robinson, Robert A

    2017-10-01

    Basal cell predominant salivary gland neoplasms can be difficult to separate histologically. One of the most aggressive of basaloid salivary gland neoplasms is adenoid cystic carcinoma. MYB expression by immunohistochemistry has been documented in adenoid cystic carcinoma. Some investigators have suggested that using this expression can help in establishing the diagnosis of adenoid cystic carcinoma. Utilizing tissue microarrays, we studied a group of basal cell adenocarcinomas and basal cell adenomas to determine: (i) whether either tumor expressed MYB and (ii) the frequency of any expression in either tumors. Seventeen salivary gland basal cell adenocarcinomas and 30 salivary gland basal cell adenomas were used to construct microarrays. These tissue microarrays were used to assess for immunohistochemical MYB expression. Fifty-three percent (nine of 17) of salivary gland basal cell adenocarcinomas and 57% (17 of 30) of salivary gland basal cell adenomas showed MYB overexpression. For comparison, we studied 11 adenoid cystic carcinomas for MYB expression and found that 64% (seven of 11) overexpressed MYB. We found no relation to clinical course for basal adenomas or basal cell adenocarcinomas that overexpressed MYB vs those that did not. MYB expression does not help separate basal cell adenocarcinomas from basal cell adenomas, and our data suggest it does not differentiate between either of these neoplasms and adenoid cystic carcinoma. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  7. Differentiation of mesenchymal stem cells derived from pancreatic islets and bone marrow into islet-like cell phenotype.

    Directory of Open Access Journals (Sweden)

    Cristina Zanini

    Full Text Available BACKGROUND: Regarding regenerative medicine for diabetes, accessible sources of Mesenchymal Stem Cells (MSCs for induction of insular beta cell differentiation may be as important as mastering the differentiation process itself. METHODOLOGY/PRINCIPAL FINDINGS: In the present work, stem cells from pancreatic islets (human islet-mesenchymal stem cells, HI-MSCs and from human bone marrow (bone marrow mesenchymal stem cells, BM-MSCs were cultured in custom-made serum-free medium, using suitable conditions in order to induce differentiation into Islet-like Cells (ILCs. HI-MSCs and BM-MSCs were positive for the MSC markers CD105, CD73, CD90, CD29. Following this induction, HI-MSC and BM-MSC formed evident islet-like structures in the culture flasks. To investigate functional modifications after induction to ILCs, ultrastructural analysis and immunofluorescence were performed. PDX1 (pancreatic duodenal homeobox gene-1, insulin, C peptide and Glut-2 were detected in HI-ILCs whereas BM-ILCs only expressed Glut-2 and insulin. Insulin was also detected in the culture medium following glucose stimulation, confirming an initial differentiation that resulted in glucose-sensitive endocrine secretion. In order to identify proteins that were modified following differentiation from basal MSC (HI-MSCs and BM-MSCs to their HI-ILCs and BM-ILCs counterparts, proteomic analysis was performed. Three new proteins (APOA1, ATL2 and SODM were present in both ILC types, while other detected proteins were verified to be unique to the single individual differentiated cells lines. Hierarchical analysis underscored the limited similarities between HI-MSCs and BM-MSCs after induction of differentiation, and the persistence of relevant differences related to cells of different origin. CONCLUSIONS/SIGNIFICANCE: Proteomic analysis highlighted differences in the MSCs according to site of origin, reflecting spontaneous differentiation and commitment. A more detailed understanding of

  8. 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.

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

    DEFF Research Database (Denmark)

    Pedersen, Morten Gram

    2006-01-01

    Pancreatic beta-cells secrete insulin in response to raised glucose levels. Malfunctioning of this system plays an important role in the metabolic disease diabetes. The biological steps from glucose stimulus to the final release of insulin are incompletely understood, and a more complete descript......Pancreatic beta-cells secrete insulin in response to raised glucose levels. Malfunctioning of this system plays an important role in the metabolic disease diabetes. The biological steps from glucose stimulus to the final release of insulin are incompletely understood, and a more complete...... 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...... biological hypotheses. The subjects addressed are: Quasi-steady-state approximations of enzyme reactions, the effect of noise on bursting electrical behavior, exciation wave propagation in pancreatic islets, intra- and inter-islet synchronization and pulsatile insulin secretion, and mitochondrial dynamics....

  10. 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.

  11. Islet microenvironment, modulated by vascular endothelial growth factor-A signaling, promotes β cell regeneration

    Science.gov (United States)

    Brissova, Marcela; Aamodt, Kristie; Brahmachary, Priyanka; Prasad, Nripesh; Hong, Ji-Young; Dai, Chunhua; Mellati, Mahnaz; Shostak, Alena; Poffenberger, Greg; Aramandla, Radhika; Levy, Shawn E.; Powers, Alvin C.

    2014-01-01

    SUMMARY Pancreatic islet endocrine cell and endothelial cell (EC) interactions mediated by vascular endothelial growth factor-A (VEGF-A) signaling are important for islet differentiation and the formation of highly vascularized islets. To dissect how VEGF-A signaling modulates intra-islet vasculature, islet microenvironment, and β cell mass, we transiently increased VEGF-A production by β cells. VEGF-A induction dramatically increased the number of intra-islet ECs but led to β cell loss. After withdrawal of the VEGF-A stimulus, β cell mass, function, and islet structure normalized as a result of a robust, but transient, burst in proliferation of pre-existing β cells. Bone marrow-derived macrophages (MΦs) recruited to the site of β cell injury were crucial for the β cell proliferation, which was independent of pancreatic location and circulating factors such as glucose. Identification of the signals responsible for the proliferation of adult, terminally differentiated β cells will improve strategies aimed at β cell regeneration and expansion. PMID:24561261

  12. Microencapsulation of islets with living cells using polyDNA-PEG-lipid conjugate.

    Science.gov (United States)

    Teramura, Yuji; Minh, Luan Nguyen; Kawamoto, Takuo; Iwata, Hiroo

    2010-04-21

    Microencapsulation of islets with a semipermeable membrane, i.e., bioartificial pancreas, is a promising way to transplant islets without the need for immunosuppressive therapy for insulin-dependent diabetes mellitus (type I diabetes). However, materials composing a bioartificial pancreas are not ideal and might activate defense reactions against foreign materials. In this study, we propose an original method for microencapsulation of islets with living cells using an amphiphilic poly(ethylene glyocol)-conjugated phospholipid derivative (PEG-lipid) and DNA hybridization. PolyA and polyT were introduced onto the surfaces of the islets and HEK 293 cells, respectively, using amphiphilic PEG-lipid derivatives. PolyA20 modified HEK cells were immobilized onto the islet surface where polyT20-PEG-lipid was incorporated. The cells spread and proliferated on the islet surface, and the islet surface was completely encapsulated with a cell layer after culture. The encapsulated islets retained the ability to control insulin release in response to glucose concentration changes.

  13. Silent Crooke's cell corticotroph adenoma of the pituitary gland presenting as delayed puberty.

    Science.gov (United States)

    Giri, Dinesh; Roncaroli, Federico; Sinha, Ajay; Didi, Mohammed; Senniappan, Senthil

    2017-01-01

    Corticotroph adenomas are extremely rare in children and adolescents. We present a 15-year-old boy who was investigated for delayed puberty (A1P2G1, bilateral testicular volumes of 3 mL each). There was no clinical or laboratory evidence suggestive of chronic illness, and the initial clinical impression was constitutional delay in puberty. Subsequently, MRI scan of the brain revealed the presence of a mixed cystic and solid pituitary lesion slightly displacing the optic chiasma. The lesion was removed by transphenoidal surgery and the biopsy confirmed the lesion to be pituitary adenoma. Furthermore, the adenoma cells also had Crooke's hyaline changes and were intensely positive for ACTH. However there was no clinical/biochemical evidence of ACTH excess. There was a spontaneous pubertal progression twelve months after the surgery (A2P4G4, with bilateral testicular volume of 8 mL). Crooke's cell adenoma is an extremely rare and aggressive variant of corticotroph adenoma that can uncommonly present as a silent corticotroph adenoma in adults. We report for the first time Crooke's cell adenoma in an adolescent boy presenting with delayed puberty. Constitutional delay of growth and puberty (CDGP) is a diagnosis of exclusion; hence a systematic and careful review should be undertaken while assessing boys with delayed puberty.Crooke's cell adenomas are a group of corticotroph adenomas that can rarely present in childhood and adolescence with delayed puberty.Crooke's cell adenomas can be clinically silent but are potentially aggressive tumours that require careful monitoring.

  14. 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.

  15. Importance of Aggregated Islet Amyloid Polypeptide for the Progressive Beta-Cell Failure in Type 2 Diabetes and in Transplanted Human Islets

    OpenAIRE

    Westermark, Gunilla T.; Per Westermark

    2009-01-01

    Original Publication: Gunilla Westermark and Per Westermark, Importance of Aggregated Islet Amyloid Polypeptide for the Progressive Beta-Cell Failure in Type 2 Diabetes and in Transplanted Human Islets, 2008, EXPERIMENTAL DIABETES RESEARCH, (2008), 528354. http://dx.doi.org/10.1155/2008/528354 Copyright: Authors

  16. Functional and immunohistochemical evaluation of porcine neonatal islet-like cell clusters

    DEFF Research Database (Denmark)

    Nielsen, T B; Yderstraede, K B; Schrøder, H D

    2003-01-01

    Porcine neonatal islet-like cell clusters (NICCs) may be an attractive source of insulin-producing tissue for xenotransplantation in type I diabetic patients. We examined the functional and immunohistochemical outcome of the islet grafts in vitro during long-term culture and in vivo after...

  17. Functional and immunohistochemical evaluation of porcine neonatal islet-like cell clusters

    DEFF Research Database (Denmark)

    Nielsen, T B; Yderstraede, K B; Schrøder, H D

    2003-01-01

    Porcine neonatal islet-like cell clusters (NICCs) may be an attractive source of insulin-producing tissue for xenotransplantation in type I diabetic patients. We examined the functional and immunohistochemical outcome of the islet grafts in vitro during long-term culture and in vivo after transpl...

  18. Myoepithelial cells are the main component in pleomorphic adenomas?

    Science.gov (United States)

    Ponce Bravo, Santa; Ledesma Montes, Constantino; López Becerril, Uriel; Morales Sánchez, Israel

    2007-03-01

    The aim of this study was to quantify by immunohistochemistry the number of myoepithelial cells (MyECs) in pleomorphic adenomas (PAs). We retrieved the paraffin cubes of 27 PAs, new slides were done and they were stained with anti-S100 protein antibody. The amount of S-100 protein positive cells was quantified, their morphology was recorded and comparison among MyEC number with age, gender and involved gland were also done. With S-100 protein, MyECs in normal salivary gland tissue were seen surrounding the ductual structures only. In the analysed PAs a mean of 27.4% of the neoplastic cells were positive to the antibody. With the exception of one PA, in all the analysed cases the plasmacytoid cells were the most commonly identified cells (48,6%). Results of this study suggest that MyECs do not constitute the main cellular component of the neoplastic compartment in PAs and corroborate the previously reported evidence by different authors, who studying the PAs suggested that MyECs does not comprise the main cellular neoplastic component of these entities.

  19. Cell loss during pseudoislet formation hampers profound improvements in islet lentiviral transduction efficacy for transplantation purposes.

    Science.gov (United States)

    Callewaert, H; Gysemans, C; Cardozo, A K; Elsner, M; Tiedge, M; Eizirik, D L; Mathieu, C

    2007-01-01

    Islet transplantation is a promising treatment in type 1 diabetes, but the need for chronic immunosuppression is a major hurdle to broad applicability. Ex vivo introduction of agents by lentiviral vectors-improving beta-cell resistance against immune attack-is an attractive path to pursue. The aim of this study was to investigate whether dissociation of islets to single cells prior to viral infection and reaggregation before transplantation would improve viral transduction efficacy without cytotoxicity. This procedure improved transduction efficacy with a LV-pWPT-CMV-EGFP construct from 11.2 +/- 4.1% at MOI 50 in whole islets to 80.0 +/- 2.8% at MOI 5. Viability (as measured by Hoechst/PI) and functionality (as measured by glucose challenge) remained high. After transplantation, the transfected pseudoislet aggregates remained EGFP positive for more than 90 days and the expression of EGFP colocalized primarily with the insulin-positive beta-cells. No increased vulnerability to immune attack was observed in vitro or in vivo. These data demonstrate that dispersion of islets prior to lentiviral transfection and reaggregation prior to transplantation is a highly efficient way to introduce genes of interest into islets for transplantation purposes in vitro and in vivo, but the amount of beta-cells needed for normalization of glycemia was more than eightfold higher when using dispersed cell aggregates versus unmanipulated islets. The high price to pay to reach stable and strong transgene expression in islet cells is certainly an important cell loss.

  20. Basal cell adenoma of the parotid gland. Case report and review of the literature.

    Science.gov (United States)

    González-García, Raúl; Nam-Cha, Syong H; Muñoz-Guerra, Mario F; Gamallo-Amat, C

    2006-03-01

    Basal cell adenoma of the salivary glands is an uncommon type of monomorphous adenoma. Its most frequent location is the parotid gland. It usually appears as a firm and mobile slow-growing mass. Histologically, isomorphic cells in nests and interlaced trabecules with a prominent basal membrane are observed. It is also characterized by the presence of a slack and hyaline stroma and the absence of myxoid or condroid stroma. In contrast to pleomorphic adenoma, it tends to be multiple and its recurrence rate after surgical excision is high. Due to prognostic implications, differential diagnosis with basal cell adenocarcinoma, adenoid cystic carcinoma and basaloid squamous cell carcinoma is mandatory. We describe a case of basal cell adenoma of the parotid gland. We also review the literature and discuss the diagnosis and management of this rare entity.

  1. Evaluation of islets derived from human fetal pancreatic progenitor cells in diabetes treatment.

    Science.gov (United States)

    Zhang, Wen-Jian; Xu, Shi-Qing; Cai, Han-Qing; Men, Xiu-Li; Wang, Zai; Lin, Hua; Chen, Li; Jiang, Yong-Wei; Liu, Hong-Lin; Li, Cheng-Hui; Sui, Wei-Guo; Deng, Hong-Kui; Lou, Jin-Ning

    2013-01-01

    With the shortage of donor organs for islet transplantation, insulin-producing cells have been generated from different types of stem cell. Human fetal pancreatic stem cells have a better self-renewal capacity than adult stem cells and can readily differentiate into pancreatic endocrine cells, making them a potential source for islets in diabetes treatment. In the present study, the functions of pancreatic islets derived from human fetal pancreatic progenitor cells were evaluated in vitro and in vivo. Human pancreatic progenitor cells isolated from the fetal pancreas were expanded and differentiated into islet endocrine cells in culture. Markers for endocrine and exocrine functions as well as those for alpha and beta cells were analyzed by immunofluorescent staining and enzyme-linked immunosorbent assay (ELISA). To evaluate the functions of these islets in vivo, the islet-like structures were transplanted into renal capsules of diabetic nude mice. Immunohistochemical staining for human C-peptide and human mitochondrion antigen was applied to confirm the human origin and the survival of grafted islets. Human fetal pancreatic progenitor cells were able to expand in medium containing basic fibroblast growth factor (bFGF) and leukemia inhibitor factor (LIF), and to differentiate into pancreatic endocrine cells with high efficiency upon the actions of glucagon-like peptide-1 and activin-A. The differentiated cells expressed insulin, glucagon, glucose transporter-1 (GLUT1), GLUT2 and voltage-dependent calcium channel (VDCC), and were able to aggregate into islet-like structures containing alpha and beta cells upon suspension. These structures expressed and released a higher level of insulin than adhesion cultured cells, and helped to maintain normoglycemia in diabetic nude mice after transplantation. Human fetal pancreatic progenitor cells have good capacity for generating insulin producing cells and provide a promising potential source for diabetes treatment.

  2. Non-invasive discrimination between pancreatic islets and exocrine cells using multiphoton microscopy

    Science.gov (United States)

    Wu, Binlin; Li, Ge; Hao, Mingming; Mukherjee, Sushmita

    2015-03-01

    In this study, we propose a non-invasive method to distinguish pancreatic islet cells from exocrine cell clusters using multiphoton (MP) imaging. We demonstrate the principle of distinguishing them based on autofluorescence. The results show that MP imaging has a potential to distinguish pancreatic islets from exocrine cells. This ability to distinguish the two cell types could have many applications, such as the examination of fresh pancreatic biopsies when staining is not possible or desirable.

  3. Silent Crooke’s cell corticotroph adenoma of the pituitary gland presenting as delayed puberty

    Directory of Open Access Journals (Sweden)

    Dinesh Giri

    2017-03-01

    Full Text Available Corticotroph adenomas are extremely rare in children and adolescents. We present a 15-year-old boy who was investigated for delayed puberty (A1P2G1, bilateral testicular volumes of 3 mL each. There was no clinical or laboratory evidence suggestive of chronic illness, and the initial clinical impression was constitutional delay in puberty. Subsequently, MRI scan of the brain revealed the presence of a mixed cystic and solid pituitary lesion slightly displacing the optic chiasma. The lesion was removed by transphenoidal surgery and the biopsy confirmed the lesion to be pituitary adenoma. Furthermore, the adenoma cells also had Crooke’s hyaline changes and were intensely positive for ACTH. However there was no clinical/biochemical evidence of ACTH excess. There was a spontaneous pubertal progression twelve months after the surgery (A2P4G4, with bilateral testicular volume of 8 mL. Crooke’s cell adenoma is an extremely rare and aggressive variant of corticotroph adenoma that can uncommonly present as a silent corticotroph adenoma in adults. We report for the first time Crooke’s cell adenoma in an adolescent boy presenting with delayed puberty.

  4. 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

    graft rejection alleviated. The immunological mechanisms of protection are mediated through deletion and induction of unresponsiveness in targeted memory T-cell populations. The data demonstrate that hematopoietic stem cell–mediated gene therapy effectively terminates antigen-specific memory T...... 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......-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....

  5. Cytopathologic, Histopathologic, and Immunohistochemical Features of Intrahepatic Clear Cell Bile Duct Adenoma: A Case Report and Review of the Literature

    OpenAIRE

    William W. Wu; Mai Gu; Di Lu

    2014-01-01

    Intrahepatic clear cell bile duct adenoma is extremely rare, with only 3 previous cases reported in the literature. The cause of cytoplasmic clearing in clear cell bile duct adenoma has not been previously investigated. Distinguishing clear cell bile duct adenoma from other clear cell tumors, particularly clear cell cholangiocarcinoma, can be challenging. Previous studies have shown loss of CD10 expression and focal CD56 expression in cholangiocarcinoma. Expressions of CD10 and CD56 have not...

  6. Identification of transplanted pancreatic islet cells by radioactive dithizone-[131I]-histamine conjugate. Preliminary report.

    Science.gov (United States)

    Garnuszek, P; Licińska, I; Mrozek, A; Wardawa, A; Fiedor, P S; Mazurek, A P

    2000-01-01

    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-[(131)I]-Histamine conjugate have been evaluated in the present study. The four islet cells transplantation models were chosen for this purpose. The most important feature of the Dithizone-[(131)I]-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-[(131)I]-Histamine conjugate. The level of the radioactivity in the recipient testis (right) was almost two times higher compared to the controls (0.24 vs. 0.13% ID/g, respectively). 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.

  7. Commercially available gas-permeable cell culture bags may not prevent anoxia in cultured or shipped islets.

    Science.gov (United States)

    Avgoustiniatos, E S; Hering, B J; Rozak, P R; Wilson, J R; Tempelman, L A; Balamurugan, A N; Welch, D P; Weegman, B P; Suszynski, T M; Papas, K K

    2008-03-01

    Prolonged anoxia has deleterious effects on islets. Gas-permeable cell culture devices can be used to minimize anoxia during islet culture and especially during shipment when elimination of gas-liquid interfaces is required to prevent the formation of damaging gas bubbles. Gas-permeable bags may have several drawbacks, such as propensity for puncture and contamination, difficult islet retrieval, and significantly lower oxygen permeability than silicone rubber membranes (SRM). We hypothesized that oxygen permeability of bags may be insufficient for islet oxygenation. We measured oxygen transmission rates through the membrane walls of three different types of commercially available bags and through SRM currently used for islet shipment. We found that the bag membranes have oxygen transmission rates per unit area about 100-fold lower than SRM. We solved the oxygen diffusion-reaction equation for 150-microm diameter islets seeded at 3000 islet equivalents per cm2, a density adequate to culture and ship an entire human or porcine islet preparation in a single gas-permeable device, predicting that about 40% of the islet volume would be anoxic at 22 degrees C and about 70% would be anoxic at 37 degrees C. Islets of larger size or islets accumulated during shipment would be even more anoxic. The model predicted no anoxia in islets similarly seeded in devices with SRM bottoms. We concluded that commercially available bags may not prevent anoxia during islet culture or shipment; devices with SRM bottoms are more suitable alternatives.

  8. Improvement of subcutaneous bioartificial pancreas vascularization and function by coencapsulation of pig islets and mesenchymal stem cells in primates.

    Science.gov (United States)

    Vériter, Sophie; Gianello, Pierre; Igarashi, Yasuhiro; Beaurin, Gwen; Ghyselinck, Audrey; Aouassar, Najima; Jordan, Bénédicte; Gallez, Bernard; Dufrane, Denis

    2014-01-01

    Insufficient oxygenation can limit the long-term survival of encapsulated islets in subcutaneous tissue. Transplantation of coencapsulated pig islets with adipose or bone marrow mesenchymal stem cells (AMSCs or BM-MSCs, respectively) was investigated with regard to implant vascularization, oxygenation, and diabetes correction in primates. The in vivo impact of MSCs on graft oxygenation and neovascularization was assessed in rats with streptozotocin (STZ)-induced diabetes that were subcutaneously transplanted with islets coencapsulated with AMSCs (n = 8) or BM-MSCs (n = 6). Results were compared to islets encapsulated alone (n = 8). STZ diabetic primates were subcutaneously transplanted with islets coencapsulated with BM-MSCs (n = 4) or AMSCs (n = 6). Recipients were monitored metabolically and immunologically, and neoangiogenesis was assessed on explanted grafts. Results were compared with primates transplanted with islets encapsulated alone (n = 5). The cotransplantation of islets with BM-MSCs or AMSCs in diabetic rats showed significantly higher graft oxygenation than islets alone (3% and 3.6% O2 for islets + BM-MSCs or AMSCs, respectively, vs. 2.2% for islets alone). A significantly better glycated hemoglobin correction (28 weeks posttransplantation) was found for primates transplanted with islets and MSCs (7.4% and 8.1%, respectively) in comparison to islets encapsulated alone (10.9%). Greater neoangiogenesis was found in the periphery of coencapsulated islets and AMSCs in comparison to islets alone (p pig islets with MSCs can improve significantly the islets' survival/function in vitro. The coencapsulation of islets with MSCs improves implant oxygenation and neoangiogenesis. However, the cotransplantation of islets with MSCs improves only slightly the long-term function of a subcutaneous bioartificial pancreas in a primate preclinical model.

  9. 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.

  10. Gap junctions and other mechanisms of cell-cell communication regulate basal insulin secretion in the pancreatic islet.

    Science.gov (United States)

    Benninger, R K P; Head, W Steven; Zhang, Min; Satin, Leslie S; Piston, David W

    2011-11-15

    Cell-cell communication in the islet of Langerhans is important for the regulation of insulin secretion. Gap-junctions coordinate oscillations in intracellular free-calcium ([Ca(2+)](i)) and insulin secretion in the islet following elevated glucose. Gap-junctions can also ensure that oscillatory [Ca(2+)](i) ceases when glucose is at a basal levels. We determine the roles of gap-junctions and other cell-cell communication pathways in the suppression of insulin secretion under basal conditions. Metabolic, electrical and insulin secretion levels were measured from islets lacking gap-junction coupling following deletion of connexion36 (Cx36(-/-)), and these results were compared to those obtained using fully isolated β-cells. K(ATP) loss-of-function islets provide a further experimental model to specifically study gap-junction mediated suppression of electrical activity. In isolated β-cells or Cx36(-/-) islets, elevations in [Ca(2+)](i) persisted in a subset of cells even at basal glucose. Isolated β-cells showed elevated insulin secretion at basal glucose; however, insulin secretion from Cx36(-/-) islets was minimally altered. [Ca(2+)](i) was further elevated under basal conditions, but insulin release still suppressed in K(ATP) loss-of-function islets. Forced elevation of cAMP led to PKA-mediated increases in insulin secretion from islets lacking gap-junctions, but not from islets expressing Cx36 gap junctions. We conclude there is a redundancy in how cell-cell communication in the islet suppresses insulin release. Gap junctions suppress cellular heterogeneity and spontaneous [Ca(2+)](i) signals, while other juxtacrine mechanisms, regulated by PKA and glucose, suppress more distal steps in exocytosis. Each mechanism is sufficiently robust to compensate for a loss of the other and still suppress basal insulin secretion.

  11. The effect of Nrf2 pathway activation on human pancreatic islet cells.

    Science.gov (United States)

    Masuda, Yuichi; Vaziri, Nosratola D; Li, Shiri; Le, Aimee; Hajighasemi-Ossareh, Mohammad; Robles, Lourdes; Foster, Clarence E; Stamos, Michael J; Al-Abodullah, Ismail; Ricordi, Camillo; Ichii, Hirohito

    2015-01-01

    Pancreatic islets are known to contain low level of antioxidants that renders them vulnerable to oxidative stress. Nrf2 is the master regulator of numerous genes, encoding antioxidant, detoxifying, and cytoprotective molecules. Activation of Nrf2 pathway induces up-regulation of numerous genes encoding antioxidant and phase II detoxifying enzymes and related proteins. However, little is known regarding the role of this pathway in human islet cells. The aim was to investigate the effect of Nrf2 activator (dh404, CDDO-9,11-dihydro-trifluoroethyl amide) on human islet cells. Human islets were obtained from cadaveric donors. After dh404 treatment, Nrf2 translocation, mRNA expression, and protein abundance of its key target gene products were examined. The proportion of dh404-treated or non-treated viable islet beta cells was analyzed using flowcytemetry. The cytoprotective effects against oxidative stress and production of inflammatory mediators, and in vivo islet function after transplantation were determined. Nrf2 nuclear translocation was confirmed by con-focal microscope within 2 hours after treatment, which was associated with a dose-dependent increase in mRNA expression of anti-oxidants, including NQO1, HO-1, and GCLC. Enhanced HO-1 expression in dh404 treated islets was confirmed by Western Blot assay. Islet function after transplantation (2000 IEQ/mouse) to diabetic nude mice was not affected with or without dh404 treatment. After induction of oxidative stress with hydrogen peroxide (200 μM) the proportion of dh404-treated viable islet cells was significantly higher in the dh404-treated than untreated islets (74% vs.57%; P<0.05). Dh404 significantly decreased production of cytokines/chemokines including IL-1β, IL-6, IFN-γ and MCP-1. Treatment of human pancreatic islets with the potent synthetic Nrf2 activator, dh404, significantly increased expression of the key anti-oxidants enzymes, decreased inflammatory mediators in islets and conferred protection

  12. The effect of Nrf2 pathway activation on human pancreatic islet cells.

    Directory of Open Access Journals (Sweden)

    Yuichi Masuda

    Full Text Available Pancreatic islets are known to contain low level of antioxidants that renders them vulnerable to oxidative stress. Nrf2 is the master regulator of numerous genes, encoding antioxidant, detoxifying, and cytoprotective molecules. Activation of Nrf2 pathway induces up-regulation of numerous genes encoding antioxidant and phase II detoxifying enzymes and related proteins. However, little is known regarding the role of this pathway in human islet cells. The aim was to investigate the effect of Nrf2 activator (dh404, CDDO-9,11-dihydro-trifluoroethyl amide on human islet cells.Human islets were obtained from cadaveric donors. After dh404 treatment, Nrf2 translocation, mRNA expression, and protein abundance of its key target gene products were examined. The proportion of dh404-treated or non-treated viable islet beta cells was analyzed using flowcytemetry. The cytoprotective effects against oxidative stress and production of inflammatory mediators, and in vivo islet function after transplantation were determined.Nrf2 nuclear translocation was confirmed by con-focal microscope within 2 hours after treatment, which was associated with a dose-dependent increase in mRNA expression of anti-oxidants, including NQO1, HO-1, and GCLC. Enhanced HO-1 expression in dh404 treated islets was confirmed by Western Blot assay. Islet function after transplantation (2000 IEQ/mouse to diabetic nude mice was not affected with or without dh404 treatment. After induction of oxidative stress with hydrogen peroxide (200 μM the proportion of dh404-treated viable islet cells was significantly higher in the dh404-treated than untreated islets (74% vs.57%; P<0.05. Dh404 significantly decreased production of cytokines/chemokines including IL-1β, IL-6, IFN-γ and MCP-1.Treatment of human pancreatic islets with the potent synthetic Nrf2 activator, dh404, significantly increased expression of the key anti-oxidants enzymes, decreased inflammatory mediators in islets and conferred

  13. Establishment and characterization of pleomorphic adenoma cell systems: an in-vitro demonstration of carcinomas arising secondarily from adenomas in the salivary gland

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    Shimizu Yoshiko

    2009-07-01

    Full Text Available Abstract Background Among the salivary gland carcinomas, carcinoma in pleomorphic adenoma has been regarded as a representative carcinoma type which arises secondarily in the background of a pre-existent benign pleomorphic adenoma. It is still poorly understood how and which benign pleomorphic adenoma cells transform into its malignant form, carcinoma ex pleomorphic adenoma. Methods We have established five cell systems from a benign pleomorphic adenoma of the parotid gland of a 61-year-old woman. They were characterized by immunofluorescence, classical cytogenetics, p53 gene mutational analysis, fluorescence in-situ hybridization, and histopathological and immunohistochemical examinations of their xenografts, to demonstrate their potency of secondary transformation. Results We established and characterized five cell systems (designated as SM-AP1 to SM-AP5 from a benign pleomorphic adenoma of the parotid gland. SM-AP1 to SM-AP3 showed polygonal cell shapes while SM-AP4 and SM-AP5 were spindle-shaped. SM-AP1-3 cells were immunopositive for keratin only, indicating their duct-epithelial or squamous cell differentiation, while SM-AP4/5 cells were positive for both keratin and S-100 protein, indicating their myoepithelial cell differentiation. Chromosome analyses showed numeral abnormalities such as 5n ploidies and various kinds of structural abnormalities, such as deletions, translocations, derivatives and isodicentric chromosomes. Among them, der(9t(9;13(p13.3;q12.3 was shared by all five of the cell systems. In addition, they all had a common deletion of the last base G of codon 249 (AGG to AG_ of the p53 gene, which resulted in generation of its nonsense gene product. Transplanted cells in nude mice formed subcutaneous tumors, which had histological features of squamous cell carcinoma with apparent keratinizing tendencies. In addition, they had ductal arrangements or plasmacytoid appearances of tumor cells and myxoid or hyaline stromata

  14. Hair Follicle Dermal Sheath Derived Cells Improve Islet Allograft Survival without Systemic Immunosuppression

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    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.

  15. 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

    Islets of Langerhans control whole body glucose homeostasis, as they respond, releasing hormones, to changes in nutrient concentrations in the blood stream. The regulation of hormone secretion has been the focus of attention for a long time because it is related to many metabolic disorders, including diabetes mellitus. Endocrine cells of the islet use a sophisticate system of endocrine, paracrine and autocrine signals to synchronize their activities. These signals provide a fast and accurate control not only for hormone release but also for cell differentiation and survival, key aspects in islet physiology and pathology. Among the different categories of paracrine/autocrine signals, this review highlights the role of neurotransmitters and neuropeptides. In a manner similar to neurons, endocrine cells synthesize, accumulate, release neurotransmitters in the islet milieu, and possess receptors able to decode these signals. In this review, we provide a comprehensive description of neurotransmitter/neuropetide signaling pathways present within the islet. Then, we focus on evidence supporting the concept that neurotransmitters/neuropeptides and their receptors are interesting new targets to preserve β-cell function and mass. A greater understanding of how this network of signals works in physiological and pathological conditions would advance our knowledge of islet biology and physiology and uncover potentially new areas of pharmacological intervention. J. Cell. Physiol. 231: 756-767, 2016. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  16. Hypothyroidism Affects Vascularization and Promotes Immune Cells Infiltration into Pancreatic Islets of Female Rabbits

    Science.gov (United States)

    Rodríguez-Castelán, Julia; Martínez-Gómez, Margarita; Castelán, Francisco; Cuevas, Estela

    2015-01-01

    Thyroidectomy induces pancreatic edema and immune cells infiltration similarly to that observed in pancreatitis. In spite of the controverted effects of hypothyroidism on serum glucose and insulin concentrations, the number and proliferation of Langerhans islet cells as well as the presence of extracellular matrix are affected depending on the islet size. In this study, we evaluated the effect of methimazole-induced hypothyroidism on the vascularization and immune cells infiltration into islets. A general observation of pancreas was also done. Twelve Chinchilla-breed female adult rabbits were divided into control (n = 6) and hypothyroid groups (n = 6, methimazole, 0.02% in drinking water for 30 days). After the treatment, rabbits were sacrificed and their pancreas was excised, histologically processed, and stained with Periodic Acid-Schiff (PAS) or Masson's Trichrome techniques. Islets were arbitrarily classified into large, medium, and small ones. The external and internal portions of each islet were also identified. Student-t-test and Mann-Whitney-U test or two-way ANOVAs were used to compare variables between groups. In comparison with control rabbits, hypothyroidism induced a strong infiltration of immune cells and a major presence of collagen and proteoglycans in the interlobular septa. Large islets showed a high vascularization and immune cells infiltration. The present results show that hypothyroidism induces pancreatitis and insulitis. PMID:26175757

  17. Identification of a subtype-specific ENC1 gene related to invasiveness in human pituitary null cell adenoma and oncocytomas.

    Science.gov (United States)

    Feng, Jie; Hong, Lichuan; Wu, Yonggang; Li, Chuzhong; Wan, Hong; Li, Guilin; Sun, Yilin; Yu, Shenyuan; Chittiboina, Prashant; Montgomery, Blake; Zhuang, Zhengping; Zhang, Yazhuo

    2014-09-01

    Non-functioning pituitary adenomas (NFPAs) may be locally invasive. Surgery is a treatment option, but unlike the case for functional pituitary adenomas, there are almost no drug treatments available for NFPAs. Markers of invasiveness are needed to guide therapeutic decision-making and identify potential adjuvant drugs. Owing to the highly heterogeneous nature of NFPAs, little is known regarding the subtype-specific gene expression profiles associated with invasiveness. To identify important biomarkers of invasiveness, we selected 23 null cell adenomas and 20 oncocytomas. These tumors were classified as invasive or non-invasive adenomas based on magnetic resonance imaging, pathology slides and surgical findings. Firstly, we observed that there were significant differences in expression between invasive (n = 3) and non-invasive (n = 4) adenomas by gene expression microarray. A total of 1,188 genes were differentially expressed in the invasive and non-invasive adenomas. Among these 1,188 genes, 578 were upregulated and 610 were downregulated in invasive adenomas. Secondly, the expression of ENC1, which displayed the significant alterations, was further confirmed by qRT-PCR and Western blot analysis in all 43 tumor samples and three normal pituitary glands. Low levels of ENC1 were found in tumor samples, while high levels were detected in normal pituitary glands. Interestingly, the ENC1 expression level was low in invasive null cell adenomas compared with non-invasive adenomas, but this relationship was not observed in invasive oncocytomas. Immunohistochemistry also demonstrated that the staining of ENC1 was different between invasive and non-invasive null cell adenomas. In addition, bioinformatics studies, including gene ontology and protein interaction analyses, were also performed to better understand the critical role of ENC1 in the development and progression of null cell adenomas and oncocytomas. Consequently, ENC1 may be an important biomarker for null cell

  18. Islet cell transplantation for the treatment of type 1 diabetes: recent advances and future challenges

    Directory of Open Access Journals (Sweden)

    Bruni A

    2014-06-01

    Full Text Available Anthony Bruni, Boris Gala-Lopez, Andrew R Pepper, Nasser S Abualhassan, AM James Shapiro Clinical Islet Transplant Program and Department of Surgery, University of Alberta, Edmonton, AB, Canada Abstract: Islet transplantation is a well-established therapeutic treatment for a subset of patients with complicated type I diabetes mellitus. Prior to the Edmonton Protocol, only 9% of the 267 islet transplant recipients since 1999 were insulin independent for >1 year. In 2000, the Edmonton group reported the achievement of insulin independence in seven consecutive patients, which in a collaborative team effort propagated expansion of clinical islet transplantation centers worldwide in an effort to ameliorate the consequences of this disease. To date, clinical islet transplantation has established improved success with insulin independence rates up to 5 years post-transplant with minimal complications. In spite of marked clinical success, donor availability and selection, engraftment, and side effects of immunosuppression remain as existing obstacles to be addressed to further improve this therapy. Clinical trials to improve engraftment, the availability of insulin-producing cell sources, as well as alternative transplant sites are currently under investigation to expand treatment. With ongoing experimental and clinical studies, islet transplantation continues to be an exciting and attractive therapy to treat type I diabetes mellitus with the prospect of shifting from a treatment for some to a cure for all. Keywords: islet transplantation, type I diabetes mellitus, Edmonton Protocol, engraftment, immunosuppression

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

    Directory of Open Access Journals (Sweden)

    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. 

  20. Localization of dipeptidyl peptidase-4 (CD26) to human pancreatic ducts and islet alpha cells.

    Science.gov (United States)

    Augstein, Petra; Naselli, Gaetano; Loudovaris, Thomas; Hawthorne, Wayne J; Campbell, Peter; Bandala-Sanchez, Esther; Rogers, Kelly; Heinke, Peter; Thomas, Helen E; Kay, Thomas W; Harrison, Leonard C

    2015-12-01

    DPP-4/CD26 degrades the incretins GLP-1 and GIP. The localization of DPP-4 within the human pancreas is not well documented but is likely to be relevant for understanding incretin function. We aimed to define the cellular localization of DPP-4 in the human pancreas from cadaveric organ donors with and without diabetes. Pancreas was snap-frozen and immunoreactive DPP-4 detected in cryosections using the APAAP technique. For co-localization studies, pancreas sections were double-stained for DPP-4 and proinsulin or glucagon and scanned by confocal microscopy. Pancreata were digested and cells in islets and in islet-depleted, duct-enriched digests analyzed for expression of DPP-4 and other markers by flow cytometry. DPP-4 was expressed by pancreatic duct and islet cells. In pancreata from donors without diabetes or with type 2 diabetes, DPP-4-positive cells in islets had the same location and morphology as glucagon-positive cells, and the expression of DPP-4 and glucagon overlapped. In donors with type 1 diabetes, the majority of residual cells in islets were DPP-4-positive. In the human pancreas, DPP-4 expression is localized to duct and alpha cells. This finding is consistent with the view that DPP-4 regulates exposure to incretins of duct cells directly and of beta cells indirectly in a paracrine manner. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  1. 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.

  2. FEM-based oxygen consumption and cell viability models for avascular pancreatic islets

    Directory of Open Access Journals (Sweden)

    Buchwald Peter

    2009-04-01

    Full Text Available Abstract Background The function and viability of cultured, transplanted, or encapsulated pancreatic islets is often limited by hypoxia because these islets have lost their vasculature during the isolation process and have to rely on gradient-driven passive diffusion, which cannot provide adequate oxygen transport. Pancreatic islets (islets of Langerhans are particularly susceptible due to their relatively large size, large metabolic demand, and increased sensitivity to hypoxia. Here, finite element method (FEM based multiphysics models are explored to describe oxygen transport and cell viability in avascular islets both in static and in moving culture media. Methods Two- and three-dimensional models were built in COMSOL Multiphysics using the convection and diffusion as well as the incompressible Navier-Stokes fluid dynamics application modes. Oxygen consumption was assumed to follow Michaelis-Menten-type kinetics and to cease when local concentrations fell below a critical threshold; in a dynamic model, it was also allowed to increase with increasing glucose concentration. Results Partial differential equation (PDE based exploratory cellular-level oxygen consumption and cell viability models incorporating physiologically realistic assumptions have been implemented for fully scaled cell culture geometries with 100, 150, and 200 μm diameter islets as representative. Calculated oxygen concentrations and intra-islet regions likely to suffer from hypoxia-related necrosis obtained for traditional flask-type cultures, oxygen-permeable silicone-rubber membrane bottom cultures, and perifusion chambers with flowing media and varying incoming glucose levels are presented in detail illustrated with corresponding colour-coded figures and animations. Conclusion Results of the computational models are, as a first estimate, in good quantitative agreement with existing experimental evidence, and they confirm that during culture, hypoxia is often a problem for

  3. Treatment of Streptozotocin Induced Diabetic Male Rats by Immunoisolated Transplantation of Islet Cells

    Directory of Open Access Journals (Sweden)

    A. Akbarzadeh

    2005-10-01

    Full Text Available Introduction & Objective: Insulin injection is the main way to combat against insulin-dependent diabetes mellitus effects. Today in some laboratories in the world, the investigators are trying to find some treatments for this disease with insulin-secreting pancreatic islet cells transplantation. Encapsulation of pancreatic islet cells allows for transplantation in the absence of immunosuppression. This technique that is called immunoisolation is based on the principle that transplanted tissue is protected for the host immune system by an artificial or natural membrane. Materials & Methods : Donor tissues in each step of work prepared from 6 adult male Wistar Rat with weight 250-300 grams (75-90 days. Transplantation were done in rats after 2-4 week induced diabetes with 60mg/ml streptozotocin injection via intravenousResults: The data obtained from this study showed that islet cells can be enclosed in a semi permeable membrane that permits oxygen and nutrients to reach the islets, allowing insulin to be released into the blood stream and at the same time excluding potentially destructive immune cells and antibodies. Conclusion: Testis subcutaneous and intrapretonea implantation of pure islet cells graft, that is a natural immunoisolation method, rapidly and permanently normalized the diabetic state of streptozocin-administered animals.

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

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    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.

  5. Stem Cells as a Tool to Improve Outcomes of Islet Transplantation

    Directory of Open Access Journals (Sweden)

    Emily Sims

    2012-01-01

    Full Text Available The publication of the promising results of the Edmonton protocol in 2000 generated optimism for islet transplantation as a potential cure for Type 1 Diabetes Mellitus. Unfortunately, follow-up data revealed that less than 10% of patients achieved long-term insulin independence. More recent data from other large trials like the Collaborative Islet Transplant Registry show incremental improvement with 44% of islet transplant recipients maintaining insulin independence at three years of follow-up. Multiple underlying issues have been identified that contribute to islet graft failure, and newer research has attempted to address these problems. Stem cells have been utilized not only as a functional replacement for β cells, but also as companion or supportive cells to address a variety of different obstacles that prevent ideal graft viability and function. In this paper, we outline the manners in which stem cells have been applied to address barriers to the achievement of long-term insulin independence following islet transplantation.

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

    Indian Academy of Sciences (India)

    Indiscriminate use of antibiotics to combat infectious diseases is one of the commonest forms of misuse of drugs. Antibiotics seem to have a correlation with diabetes and pancreatic function. There are controversial reports about the effect of antibiotics on the pancreatic islets; some suggesting their harmless action, some ...

  7. Enhanced rat beta-cell proliferation in 60% pancreatectomized islets by increased glucose metabolic flux through pyruvate carboxylase pathway.

    Science.gov (United States)

    Liu, Y Q; Han, J; Epstein, P N; Long, Y S

    2005-03-01

    Islet beta-cell proliferation is a very important component of beta-cell adaptation to insulin resistance and prevention of type 2 diabetes mellitus. However, we know little about the mechanisms of beta-cell proliferation. We now investigate the relationship between pyruvate carboxylase (PC) pathway activity and islet cell proliferation 5 days after 60% pancreatectomy (Px). Islet cell number, protein, and DNA content, indicators of beta-cell proliferation, were increased two- to threefold 5 days after Px. PC and pyruvate dehydrogenase (PDH) activities increased only approximately 1.3-fold; however, islet pyruvate content and malate release from isolated islet mitochondria were approximately threefold increased in Px islets. The latter is an indicator of pyruvate-malate cycle activity, indicating that most of the increased pyruvate was converted to oxaloacetate (OAA) through the PC pathway. The contents of OAA and malate, intermediates of the pyruvate-malate cycle, were also increased threefold. PDH and citrate content were only slightly increased. Importantly, the changes in cell proliferation parameters, glucose utilization, and oxidation and malate release were partially blocked by in vivo treatment with the PC inhibitor phenylacetic acid. Our results suggest that enhanced PC pathway in Px islets may have an important role in islet cell proliferation.

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

    Directory of Open Access Journals (Sweden)

    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.

  9. Regulatory B Cell-Dependent Islet Transplant Tolerance Is Also Natural Killer Cell Dependent.

    Science.gov (United States)

    Schuetz, C; Lee, K M; Scott, R; Kojima, L; Washburn, L; Liu, L; Liu, W-H; Tector, H; Lei, J; Yeh, H; Kim, J I; Markmann, J F

    2017-06-01

    Immunologic tolerance to solid organ and islet cell grafts has been achieved in various rodent models by using antibodies directed at CD45RB and Tim-1. We have shown that this form of tolerance depends on regulatory B cells (Bregs). To elucidate further the mechanism by which Bregs induce tolerance, we investigated the requirement of natural killer (NK) and NKT cells in this model. To do so, hyperglycemic B6, μMT, Beige, or CD1d-/- mice received BALB/c islet grafts and treatment with the tolerance-inducing regimen consisting of anti-CD45RB and anti-TIM1. B6 mice depleted of both NK and NKT cells by anti-NK1.1 antibody and mice deficient in NK activity (Beige) did not develop tolerance after dual-antibody treatment. In contrast, transplant tolerance induction was successful in CD1d-/- recipients (deficient in NKT cells), indicating that NK, but not NKT, cells are essential in B cell-dependent tolerance. In addition, reconstitution of Beige host with NK cells restored the ability to induce transplant tolerance with dual-antibody treatment. Transfer of tolerance by B cells from tolerant mice was also dependent on host Nk1.1+ cells. In conclusion, these results show that regulatory function of B cells is dependent on NK cells in this model of transplantation tolerance. © 2017 The American Society of Transplantation and the American Society of Transplant Surgeons.

  10. 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.

  11. 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.

  12. 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.

  13. Stem cells in the canine pituitary gland and in pituitary adenomas.

    Science.gov (United States)

    van Rijn, Sarah J; Tryfonidou, Marianna A; Hanson, Jeanette M; Penning, Louis C; Meij, Björn P

    2013-12-01

    Cushing's disease (CD) or pituitary-dependent hypercortisolism is a common endocrinopathy in dogs, with an estimated prevalence of 1 or 2 in 1000 dogs per year. It is caused by an adrenocorticotropic hormone secreting adenoma in the pars distalis or pars intermedia of the pituitary gland. The pituitary gland is a small endocrine gland located in the pituitary fossa. In the postnatal individual, the hypothalamus-pituitary axis plays a central role in maintaining homeostatic functions, like control of metabolism, reproduction, and growth. Stem cells are suggested to play a role in the homeostatic adaptations of the adult pituitary gland, such as the rapid specific cell-type expansion in response to pregnancy or lactation. Several cell populations have been suggested as pituitary stem cells, such as Side Population cells and cells expressing Sox2 or Nestin. These cell populations are discussed in this review. Also, stem and progenitor cells are thought to play a role in pituitary tumorigenesis, such as the development of pituitary adenomas in dogs. There are limited reports on the role of stem cells in pituitary adenomas, especially in dogs. Further studies are needed to identify and characterize this cell population and to develop specific cell targeting therapeutic strategies as a new way of treating canine CD.

  14. 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.

  15. 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.

  16. Human Islet Amyloid Polypeptide

    DEFF Research Database (Denmark)

    Kosicka, Iga

    2014-01-01

    Diabetes mellitus type II is a metabolic disease affecting millions of people worldwide. The disease is associated with occurence of insoluble, fibrillar, protein aggregates in islets of Langerhans in the pancreas - islet amyloid. The main constituent of these protein fibers is the human islet...... amyloid polypeptide, which has a propensity to form oligomeric and fibrillar aggregates consisting of stable beta-sheets. These aggregates are toxic to the pancreatic cells. In-depth knowledge of the mechanisms of islet amyloid formation is an important step towards better understanding of the etiology...... of diabetes type II, while revealing the structure(s) of islet amyloid fibrils is necessary for potential design of therapeutic agents....

  17. Recent insights in islet amyloid polypeptide-induced membrane disruption and its role in β-cell death in type II diabetes mellitus

    NARCIS (Netherlands)

    Khemtémourian, L.P.; Killian, J.A.; Höppener, J.W.M.; Engel, M.F.M.

    2008-01-01

    The presence of fibrillar protein deposits (amyloid) of human islet amyloid polypeptide (hIAPP) in the pancreatic islets of Langerhans is thought to be related to death of the insulin-producing islet β-cells in type 2 diabetes mellitus (DM2). The mechanism of hIAPP-induced β-cell death is not

  18. Gap junctions and other mechanisms of cell–cell communication regulate basal insulin secretion in the pancreatic islet

    Science.gov (United States)

    Benninger, R K P; Head, W Steven; Zhang, Min; Satin, Leslie S; Piston, David W

    2011-01-01

    Abstract Cell–cell communication in the islet of Langerhans is important for the regulation of insulin secretion. Gap-junctions coordinate oscillations in intracellular free-calcium ([Ca2+]i) and insulin secretion in the islet following elevated glucose. Gap-junctions can also ensure that oscillatory [Ca2+]i ceases when glucose is at a basal levels. We determine the roles of gap-junctions and other cell–cell communication pathways in the suppression of insulin secretion under basal conditions. Metabolic, electrical and insulin secretion levels were measured from islets lacking gap-junction coupling following deletion of connexion36 (Cx36−/−), and these results were compared to those obtained using fully isolated β-cells. KATP loss-of-function islets provide a further experimental model to specifically study gap-junction mediated suppression of electrical activity. In isolated β-cells or Cx36−/− islets, elevations in [Ca2+]i persisted in a subset of cells even at basal glucose. Isolated β-cells showed elevated insulin secretion at basal glucose; however, insulin secretion from Cx36−/− islets was minimally altered. [Ca2+]i was further elevated under basal conditions, but insulin release still suppressed in KATP loss-of-function islets. Forced elevation of cAMP led to PKA-mediated increases in insulin secretion from islets lacking gap-junctions, but not from islets expressing Cx36 gap junctions. We conclude there is a redundancy in how cell–cell communication in the islet suppresses insulin release. Gap junctions suppress cellular heterogeneity and spontaneous [Ca2+]i signals, while other juxtacrine mechanisms, regulated by PKA and glucose, suppress more distal steps in exocytosis. Each mechanism is sufficiently robust to compensate for a loss of the other and still suppress basal insulin secretion. PMID:21930600

  19. Cytokines inducing bone marrow SCA+ cells migration into pancreatic islet and conversion into insulin-positive cells in vivo.

    Directory of Open Access Journals (Sweden)

    LuGuang Luo

    Full Text Available We hypothesize that specific bone marrow lineages and cytokine treatment may facilitate bone marrow migration into islets, leading to a conversion into insulin producing cells in vivo. In this study we focused on identifying which bone marrow subpopulations and cytokine treatments play a role in bone marrow supporting islet function in vivo by evaluating whether bone marrow is capable of migrating into islets as well as converting into insulin positive cells. We approached this aim by utilizing several bone marrow lineages and cytokine-treated bone marrow from green fluorescent protein (GFP positive bone marrow donors. Sorted lineages of Mac-1(+, Mac-1(-, Sca(+, Sca(-, Sca(-/Mac-1(+ and Sca(+/Mac-1(- from GFP positive mice were transplanted to irradiated C57BL6 GFP negative mice. Bone marrow from transgenic human ubiquitin C promoter GFP (uGFP, with strong signal C57BL6 mice was transplanted into GFP negative C57BL6 recipients. After eight weeks, migration of GFP positive donor' bone marrow to the recipient's pancreatic islets was evaluated as the percentage of positive GFP islets/total islets. The results show that the most effective migration comes from the Sca(+/Mac(- lineage and these cells, treated with cytokines for 48 hours, were found to have converted into insulin positive cells in pancreatic islets in vivo. This study suggests that bone marrow lineage positive cells and cytokine treatments are critical factors in determining whether bone marrow is able to migrate and form insulin producing cells in vivo. The mechanisms causing this facilitation as well as bone marrow converting to pancreatic beta cells still need to be investigated.

  20. A rapid, efficient, and economic device and method for the isolation and purification of mouse islet cells.

    Directory of Open Access Journals (Sweden)

    Yin Zongyi

    Full Text Available Rapid, efficient, and economic method for the isolation and purification of islets has been pursued by numerous islet-related researchers. In this study, we compared the advantages and disadvantages of our developed patented method with those of commonly used conventional methods (Ficoll-400, 1077, and handpicking methods. Cell viability was assayed using Trypan blue, cell purity and yield were assayed using diphenylthiocarbazone, and islet function was assayed using acridine orange/ethidium bromide staining and enzyme-linked immunosorbent assay-glucose stimulation testing 4 days after cultivation. The results showed that our islet isolation and purification method required 12 ± 3 min, which was significantly shorter than the time required in Ficoll-400, 1077, and HPU groups (34 ± 3, 41 ± 4, and 30 ± 4 min, respectively; P 1000 islets. In summary, the MCT method is a rapid, efficient, and economic method for isolating and purifying murine islet cell clumps. This method overcomes some of the shortcomings of conventional methods, showing a relatively higher quality and yield of islets within a shorter duration at a lower cost. Therefore, the current method provides researchers with an alternative option for islet isolation and should be widely generalized.

  1. A rapid, efficient, and economic device and method for the isolation and purification of mouse islet cells.

    Science.gov (United States)

    Zongyi, Yin; Funian, Zou; Hao, Li; Ying, Cheng; Jialin, Zhang; Baifeng, Li

    2017-01-01

    Rapid, efficient, and economic method for the isolation and purification of islets has been pursued by numerous islet-related researchers. In this study, we compared the advantages and disadvantages of our developed patented method with those of commonly used conventional methods (Ficoll-400, 1077, and handpicking methods). Cell viability was assayed using Trypan blue, cell purity and yield were assayed using diphenylthiocarbazone, and islet function was assayed using acridine orange/ethidium bromide staining and enzyme-linked immunosorbent assay-glucose stimulation testing 4 days after cultivation. The results showed that our islet isolation and purification method required 12 ± 3 min, which was significantly shorter than the time required in Ficoll-400, 1077, and HPU groups (34 ± 3, 41 ± 4, and 30 ± 4 min, respectively; P 1000 islets). In summary, the MCT method is a rapid, efficient, and economic method for isolating and purifying murine islet cell clumps. This method overcomes some of the shortcomings of conventional methods, showing a relatively higher quality and yield of islets within a shorter duration at a lower cost. Therefore, the current method provides researchers with an alternative option for islet isolation and should be widely generalized.

  2. 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

    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...

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

    DEFF Research Database (Denmark)

    Vetterli, Laurène; Carobbio, Stefania; Pournourmohammadi, Shirin

    2012-01-01

    In pancreatic β-cells, glutamate dehydrogenase (GDH) modulates insulin secretion, although its function regarding specific secretagogues is unclear. This study investigated the role of GDH using a β-cell-specific GDH knockout mouse model, called βGlud1(-/-). The absence of GDH in islets isolated...... from βGlud1(-/-) mice resulted in abrogation of insulin release evoked by glutamine combined with 2-aminobicyclo[2.2.1]heptane-2-carboxylic acid or l-leucine. Reintroduction of GDH in βGlud1(-/-) islets fully restored the secretory response. Regarding glucose stimulation, insulin secretion in islets...... 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...

  4. Signals in the pancreatic islet microenvironment influence β-cell proliferation.

    Science.gov (United States)

    Aamodt, Kristie I; Powers, Alvin C

    2017-09-01

    The progressive loss of pancreatic β-cell mass that occurs in both type 1 and type 2 diabetes is a primary factor driving efforts to identify strategies for effectively increasing, enhancing or restoring β-cell mass. While factors that seem to influence β-cell proliferation in specific contexts have been described, reliable stimulation of human β-cell proliferation has remained a challenge. Importantly, β-cells exist in the context of a complex, integrated pancreatic islet microenvironment where they interact with other endocrine cells, vascular endothelial cells, extracellular matrix, neuronal projections and islet macrophages. This review highlights different components of the pancreatic microenvironment, and reviews what is known about how signaling that occurs between β-cells and these other components influences β-cell proliferation. Future efforts to further define the role of the pancreatic islet microenvironment on β-cell proliferation may lead to the development of successful approaches to increase or restore β-cell mass in diabetes. © 2017 John Wiley & Sons Ltd.

  5. 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.

  6. Development of Autoimmune-Mediated β Cell Failure After Total Pancreatectomy With Autologous Islet Transplantation.

    Science.gov (United States)

    Bellin, M D; Moran, A; Wilhelm, J J; O'Brien, T D; Gottlieb, P A; Yu, L; Dunn, T B

    2015-07-01

    Total pancreatectomy with islet autotransplantation (TPIAT) is performed for definitive treatment of chronic pancreatitis; patients are not diabetic before surgery, or have C-peptide positive pancreatogenous diabetes. Thus, TPIAT recipients are not traditionally considered at risk for autoimmune loss of the islet graft. We describe a 43-year-old female who underwent TPIAT with high mass islet graft of 6031 IEQ/kg, with no evidence of presurgical β cell autoimmunity who developed type 1 diabetes within the first year after TPIAT, resulting in complete loss of beta cell function. The patient had positive GAD and insulin autoantibodies at 1 year and 18 months after TPIAT, not present prior, and undetectable C-peptide after mixed meal and intravenous glucose tolerance testing at 18 months. Glucagon secretion was preserved, suggesting the transplanted alpha cell mass was intact. HLA typing revealed a DR3/DR4 class II haplotype. This case highlights the need to consider de novo type 1 diabetes in patients with unexpected islet graft failure after TPIAT. © Copyright 2015 The American Society of Transplantation and the American Society of Transplant Surgeons.

  7. Proteins differentially expressed in human beta-cells-enriched pancreatic islet cultures and human insulinomas

    DEFF Research Database (Denmark)

    Terra, Letícia F; Teixeira, Priscila C; Wailemann, Rosangela A M

    2013-01-01

    In view of the great demand for human beta-cells for physiological and medical studies, we generated cell lines derived from human insulinomas which secrete insulin, C-peptide and express neuroendocrine and islet markers. In this study, we set out to characterize their proteomes, comparing them...... to those of primary beta-cells using DIGE followed by MS. The results were validated by Western blotting. An average of 1800 spots was detected with less than 1% exhibiting differential abundance. Proteins more abundant in human islets, such as Caldesmon, are involved in the regulation of cell......, a molecular snapshot of the orchestrated changes in expression of proteins involved in key processes which could be correlated with the altered phenotype of human beta-cells. Collectively our observations prompt research towards the establishment of bioengineered human beta-cells providing a new and needed...

  8. A novel method for the assessment of cellular composition and beta-cell viability in human islet preparations.

    Science.gov (United States)

    Ichii, Hirohito; Inverardi, Luca; Pileggi, Antonello; Molano, R Damaris; Cabrera, Over; Caicedo, Alejandro; Messinger, Shari; Kuroda, Yoshikazu; Berggren, Per-Olof; Ricordi, Camillo

    2005-07-01

    Current methodologies to evaluate islet cell viability are largely based on tests that assess the exclusion of DNA-binding dyes. While these tests identify cells that have lost selective membrane permeability, they do not allow us to recognize apoptotic cells, which do not yet stain with DNA-binding dyes. Furthermore, current methods of analysis do not discriminate between cell subsets in the preparation and, in particular, they do not allow for selectively defining beta-cell viability. For these reasons we have developed novel methods for the specific assessment of beta-cell content and viability in human islets based on cellular composition analysis through laser scanning cytometry (LSC) coupled with identification of beta-cell-specific apoptosis at the mitochondrial level. Our novel analytical methods hold promise to prospectively analyze clinical islet transplantation preparations and predict functional performance, as suggested by the observed correlation with in vivo analysis of islet potency in immunodeficient rodents.

  9. The Edges of Pancreatic Islet β Cells Constitute Adhesive and Signaling Microdomains

    Directory of Open Access Journals (Sweden)

    Erez Geron

    2015-01-01

    Full Text Available Pancreatic islet β cells are organized in rosette-like structures around blood vessels and exhibit an artery-to-vein orientation, but they do not display the typical epithelial polarity. It is unclear whether these cells present a functional asymmetry related to their spatial organization. Here, we identify murine β cell edges, the sites at which adjacent cell faces meet at a sharp angle, as surface microdomains of cell-cell adhesion and signaling. The edges are marked by enrichment of F-actin and E-cadherin and are aligned between neighboring cells. The edge organization is E-cadherin contact dependent and correlates with insulin secretion capacity. Edges display elevated levels of glucose transporters and SNAP25 and extend numerous F-actin-rich filopodia. A similar β cell edge organization was observed in human islets. When stimulated, β cell edges exhibit high calcium levels. In view of the functional importance of intra-islet communication, the spatial architecture of their edges may prove fundamental for coordinating physiological insulin secretion.

  10. Cluster Analysis of Self-Monitoring Blood Glucose Assessments in Clinical Islet Cell Transplantation for Type 1 Diabetes

    Science.gov (United States)

    Takita, Morihito; Matsumoto, Shinichi; Noguchi, Hirofumi; Shimoda, Masayuki; Chujo, Daisuke; Itoh, Takeshi; Sugimoto, Koji; SoRelle, Jeffery A.; Onaca, Nicholas; Naziruddin, Bashoo; Levy, Marlon F.

    2011-01-01

    OBJECTIVE Cluster analysis was performed on the results of self-monitoring of blood glucose (SMBG) to discriminate islet graft function after islet cell transplantation (ICT) in patients with type 1 diabetes. RESEARCH DESIGN AND METHODS Eleven islet recipients were included in this study. The patients visited our clinic monthly after ICT and provided blood samples for fasting C-peptide (n = 270), which were used to evaluate islet graft function. They also provided their SMBG data through an automatic data collection system. The SMBG data for 3 days immediately before each clinic visit were evaluated using the following assessments: M value, mean amplitude of glycemic excursions, J index, index of glycemic control, average daily risk range, and glycemic risk assessment diabetes equation. The cluster analysis was performed for both SMBG assessments and samples. Multivariate logistic regression analysis was used to evaluate the clusters of SMBG for assessing islet graft function. RESULTS Analysis for SMBG assessments revealed five types of clusters, which showed similar patterns according to functional or dysfunctional islet graft phase. Two clusters, the euglycemia cluster (P Cluster analysis of SMBG data as part of an automated data quality system could allow discrimination of islet graft dysfunction after ICT. This approach should be considered for islet recipients. PMID:21680718

  11. Characteristic location and growth patterns of functioning pituitary adenomas: correlation with histological distribution of hormone-secreting cells in the pituitary gland.

    Science.gov (United States)

    Baik, Jun Seung; Lee, Mi Hyun; Ahn, Kook-Jin; Choi, Hyun Seok; Jung, So Lyung; Kim, Bum-Soo; Jeun, Sin Soo; Hong, Yong-Kil

    2015-01-01

    To evaluate the correlation between the magnetic resonance imaging findings of functional pituitary adenomas and histological distribution of hormone-secreting cells in pituitary gland. Forty-nine patients with pathologically confirmed functional micro and macro pituitary adenomas were retrospectively reviewed for its location and growth direction. Micro-prolactin, micro-adrenocorticotropic hormone (ACTH), and micro-growth hormone (GH) producing adenomas showed specific location (P-value adenomas showed specific growth direction (P-value adenomas did not. The functional pituitary microadenomas' location and macroadenomas' growth pattern correlate well with histological distribution of hormone-secreting cells in pituitary gland. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Histomorphology of the bottlenose dolphin (Tursiops truncatus) pancreas and association of increasing islet β-cell size with chronic hypercholesterolemia.

    Science.gov (United States)

    Colegrove, Kathleen M; Venn-Watson, Stephanie

    2015-04-01

    Bottlenose dolphins (Tursiops truncatus) can develop metabolic states mimicking prediabetes, including hyperinsulinemia, hyperlipidemia, elevated glucose, and fatty liver disease. Little is known, however, about dolphin pancreatic histomorphology. Distribution and area of islets, α, β, and δ cells were evaluated in pancreatic tissue from 22 dolphins (mean age 25.7years, range 0-51). Associations of these measurements were evaluated by sex, age, percent high glucose and lipids during the last year of life, and presence or absence of fatty liver disease and islet cell vacuolation. The most common pancreatic lesions identified were exocrine pancreas fibrosis (63.6%) and mild islet cell vacuolation (47.4%); there was no evidence of insulitis or amyloid deposition, changes commonly associated with type 2 diabetes. Dolphin islet architecture appears to be most similar to the pig, where α and β cells are localized to the central or periphery of the islet, respectively, or are well dispersed throughout the islet. Unlike pigs, large islets (greater than 10,000μm(2)) were common in dolphins, similar to that found in humans. A positive linear association was identified between dolphin age and islet area average, supporting a compensatory response similar to other species. The strongest finding in this study was a positive linear association between islet size, specifically β-cells, and percent blood samples with high cholesterol (greater than 280mg/dl, R(2)=0.57). This study is the most comprehensive assessment of the dolphin pancreas to date and may help direct future studies, including associations between chronic hypercholesterolemia and β-cell size. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Basal cell adenoma of the salivary gland: Cribriform type, a rare case with review of literature

    Directory of Open Access Journals (Sweden)

    Raghunath Prabhu

    2016-12-01

    Full Text Available Basal cell adenoma (BCA of the salivary glands is a rare benign tumor resembling pleomorphic adenoma, but with a prominent basaloid cell layer. The majority of these tumors arise in the parotid glands and account for only 1% of all salivary gland epithelial tumors. We report one such case of a swelling in the floor of the mouth in a 55-year-old female where BCA is the most likely diagnosis; however, histological variation does show a similarity to malignant adenoid cystic carcinoma, thereby making the diagnosis difficult. The incidence of malignancy is relatively higher in the submandibular, sublingual and minor salivary glands. Approximately, 85% of sublingual gland tumors are malignant. Thus, we should be more careful when making a diagnosis in minor salivary gland tumors. [Arch Clin Exp Surg 2016; 5(4.000: 246-249

  14. Granular Cell Tumour of the Bile Duct in Association with Intrahepatic Bile Duct Adenomas

    Directory of Open Access Journals (Sweden)

    F Schweiger

    1994-01-01

    Full Text Available Granular cell tumour of the extrahepatic biliary tract is a rare benign lesion likely of neurogenic origin. Review of the previously reported cases indicates that almost all patients are female, and the majority is Black. Symptoms usually are those of biliary obstruction or cholecystitis. Surgical resection of the tumour is curative. Intrahepatic bile duct adenoma is another rare benign biliary neoplasm that does not manifest clinically but can be confused with metastatic carcinoma, cholangiocarcinoma or other focal liver lesions at laparotomy or autopsy. The authors report the case of an asymptomatic Caucasian woman with biochemical evidence of liver disease who had a granular cell tumour of the bile duct as well as several intrahepatic bile duct adenomas.

  15. In Vitro Differentiation of Pluripotent Stem Cells into Functional β Islets Under 2D and 3D Culture Conditions and In Vivo Preclinical Validation of 3D Islets.

    Science.gov (United States)

    Bose, Bipasha; Sudheer, P Shenoy

    2016-01-01

    Since the advent of pluripotent stem cells, (embryonic and induced pluripotent stem cells), applications of such pluripotent stem cells are of prime importance. Indeed, scientists are involved in studying the basic biology of pluripotent stem cells, but equal impetus is there to direct the pluripotent stem cells into multiple lineages for cell therapy applications. Scientists across the globe have been successful, to a certain extent, in obtaining cells of definitive endoderm and also pancreatic β islets by differentiating human pluripotent stem cells. Pluripotent stem cell differentiation protocols aim at mimicking in vivo embryonic development. As in vivo embryonic development is a complex process and involves interplay of multiple cytokines, the differentiation protocols also involve a stepwise use of multiple cytokines. Indeed the novel markers for pancreas organogenesis serve as the roadmaps to develop new protocols for pancreatic differentiation from pluripotent stem cells. Earliest developed protocols for pancreas differentiation involved "Nestin selection pathway," a pathway common for both neuronal and pancreatic differentiation lead to the generation of cells that were a combination of cells from neuronal lineage. Eventually with the discovery of hierarchy of β cell transcription factors like Pdx1, Pax4, and Nkx2.2, forced expression of such transcription factors proved successful in converting a pluripotent stem cell into a β cell. Protocols developed almost half a decade ago to the recent ones rather involve stepwise differentiations involving various cytokines and could generate as high as 25 % functional insulin-positive cells in vitro. Most advanced protocols for β islet differentiations from human pluripotent stem cells focused on 3D culture conditions, which reportedly produced 60-65 % functional β islet cells. Here, we describe the protocol for differentiation of human pluripotent stem cells into functional β cells under both 2D and 3D

  16. 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.

  17. Long-Term Survival of Neonatal Porcine Islets Without Sertoli Cells in Rabbits

    Directory of Open Access Journals (Sweden)

    Rafael Vald and eacute;s-Gonz and aacute;lez

    2013-04-01

    Full Text Available Cell-based therapy is a promising treatment for metabolic disorders such as type-1 diabetes. Transplantation protocols have investigated several anatomical sites for cell implantation; however, some of these procedures, such as intraportal infusion, can cause organ failure or thrombosis secondarily. Bio-artificial organs could be the choice, although concerns still remain. Using a subcutaneous device, we are able to preserve neonatal porcine islets without sertoli cells in healthy New Zealand rabbits. Devices were implanted in the back of the animals underneath the skin, and after 3 months the islets were transplanted. Histology showed the presence of inflammatory cells, predominantly eosinophils; however, insulin- and glucagon-positive cell clusters were identified inside the device at different time points for at least 90 days, and porcine C-peptide was also detected during the follow-up, indicating graft functionality. We have found that our device induces the deposition of a fibrous matrix enriched in blood vessels, which forms a good place for cell grafting, and this model is probably able to induce an immunoprivileged site. Under these conditions, transplanted porcine islet cells have the capability of producing insulin and glucagon for at least three months. [Arch Clin Exp Surg 2013; 2(2.000: 101-108

  18. Islet Amyloid Polypeptide Is a Target Antigen for Diabetogenic CD4+ T Cells

    Science.gov (United States)

    Delong, Thomas; Baker, Rocky L.; Reisdorph, Nichole; Reisdorph, Richard; Powell, Roger L.; Armstrong, Michael; Barbour, Gene; Bradley, Brenda; Haskins, Kathryn

    2011-01-01

    OBJECTIVE To investigate autoantigens in β-cells, we have used a panel of pathogenic T-cell clones that were derived from the NOD mouse. Our particular focus in this study was on the identification of the target antigen for the highly diabetogenic T-cell clone BDC-5.2.9. RESEARCH DESIGN AND METHODS To purify β-cell antigens, we applied sequential size exclusion chromatography and reverse-phase high-performance liquid chromatography to membrane preparations of β-cell tumors. The presence of antigen was monitored by measuring the interferon-γ production of BDC-5.2.9 in response to chromatographic fractions in the presence of NOD antigen-presenting cells. Peak antigenic fractions were analyzed by ion-trap mass spectrometry, and candidate proteins were further investigated through peptide analysis and, where possible, testing of islet tissue from gene knockout mice. RESULTS Mass-spectrometric analysis revealed the presence of islet amyloid polypeptide (IAPP) in antigen-containing fractions. Confirmation of IAPP as the antigen target was demonstrated by the inability of islets from IAPP-deficient mice to stimulate BDC-5.2.9 in vitro and in vivo and by the existence of an IAPP-derived peptide that strongly stimulates BCD-5.2.9. CONCLUSIONS IAPP is the target antigen for the diabetogenic CD4 T-cell clone BDC-5.2.9. PMID:21734016

  19. Expression of Eag1 K+ channel and ErbBs in human pituitary adenomas: cytoskeleton arrangement patterns in cultured cells.

    Science.gov (United States)

    del Pliego, Margarita González; Aguirre-Benítez, Elsa; Paisano-Cerón, Karina; Valdovinos-Ramírez, Irene; Rangel-Morales, Carlos; Rodríguez-Mata, Verónica; Solano-Agama, Carmen; Martín-Tapia, Dolores; de la Vega, María Teresa; Saldoval-Balanzario, Miguel; Camacho, Javier; Mendoza-Garrido, María Eugenia

    2013-01-01

    Pituitary adenomas can invade surrounded tissue, but the mechanism remains elusive. Ether à go-go-1 (Eag1) potassium channel and epidermal growth factor receptors (ErbB1 and ErbB2) have been associated to invasive phenotypes or poor prognosis in cancer patients. However, cells arrange their cytoskeleton in order to acquire a successful migration pattern. We have studied ErbBs and Eag1 expression, and cytoskeleton arrangements in 11 human pituitary adenomas. Eag1, ErbB1 and ErbB2 expression were studied by immunochemistry in tissue and cultured cells. The cytoskeleton arrangement was analyzed in cultured cells by immunofluorescence. Normal pituitary tissue showed ErbB2 expression and Eag1 only in few cells. However, Eag1 and ErbB2 were expressed in all the tumors analyzed. ErbB1 expression was observed variable and did not show specificity for a tumor characteristic. Cultured cells from micro- and macro-adenomas clinically functional organize their cytoskeleton suggesting a mesenchymal pattern, and a round leucocyte/amoeboid pattern from invasive clinically silent adenoma. Pituitary tumors over-express EGF receptors and the ErbB2 repeated expression suggests is a characteristic of adenomas. Eag 1 was express, in different extent, and could be a therapeutic target. The cytoskeleton arrangements observed suggest that pituitary tumor cells acquire different patterns: mesenchymal, and leucocyte/amoeboid, the last observed in the invasive adenomas. Amoeboid migration pattern has been associated with high invasion capacity.

  20. Interrogating islets in health and disease with single-cell technologies

    Directory of Open Access Journals (Sweden)

    Andrea C. Carrano

    2017-09-01

    Major conclusions: By analyzing single islet cells from rodents and humans at different ages and disease states, the studies reviewed here have provided new insight into endocrine cell function and facilitated a high resolution molecular characterization of poorly understood processes, including regeneration, maturation, and diabetes pathogenesis. Gene expression programs and pathways identified in these studies pave the way for the discovery of new targets and approaches to prevent, monitor, and treat diabetes.

  1. Granular Cell Tumour of the Bile Duct in Association with Intrahepatic Bile Duct Adenomas

    OpenAIRE

    Schweiger, F; Radhi, J; Coop, FW; Murphy, RW

    1994-01-01

    Granular cell tumour of the extrahepatic biliary tract is a rare benign lesion likely of neurogenic origin. Review of the previously reported cases indicates that almost all patients are female, and the majority is Black. Symptoms usually are those of biliary obstruction or cholecystitis. Surgical resection of the tumour is curative. Intrahepatic bile duct adenoma is another rare benign biliary neoplasm that does not manifest clinically but can be confused with metastatic carcinoma, cholangio...

  2. 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.

  3. Islet autoantibodies and residual beta cell function in type 1 diabetes children followed for 3-6 years

    DEFF Research Database (Denmark)

    Sørensen, Jesper Sand; Vaziri-Sani, Fariba; Maziarz, M

    2012-01-01

    To test if islet autoantibodies at diagnosis of type 1 diabetes (T1DM) and after 3-6 years with T1D predict residual beta-cell function (RBF) after 3-6 years with T1D.......To test if islet autoantibodies at diagnosis of type 1 diabetes (T1DM) and after 3-6 years with T1D predict residual beta-cell function (RBF) after 3-6 years with T1D....

  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.

    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.

  5. An imidazoline compound completely counteracts interleukin-1[beta] toxic effects to rat pancreatic islet [beta] cells.

    Science.gov (United States)

    Papaccio, Gianpaolo; Nicoletti, Ferdinando; Pisanti, Francesco A; Galdieri, Michela; Bendtzen, Klaus

    2002-09-01

    In vitro studies have demonstrated that interleukin (IL)-1beta decreases insulin and DNA contents in pancreatic islet beta cells, causing structural damage, that it is toxic to cultured human islet beta cells and that it is able to induce apoptosis in these cells. Isolated rat islets of Langerhans were exposed in vitro to interleukin (IL)-1beta and either the imidazoline compound RX871024 (RX) or/and M40403, an Mn-containing superoxide dismutase mimetic (MnSODm). Insulin secretion, on days 1, 2 and 3 after challenge with 3 ng/ml of IL-1beta, was almost abolished and this was accompanied by an early increase in MnSOD activity. By days 2 and 3, SOD activities were lower than those of untreated controls and NO significantly increased by day 2. Moreover, IL-1beta induced a significant increase in MnSOD transcripts, while iNOS mRNA appeared by days 2 and 3 when MnSOD mRNA was absent. RX blocked all toxic effects of IL-1beta by maintaining insulin secretion and islet beta cell phenotype, including the inhibition of nonspecific proteins and of iNOS induction. In contrast, the MnSODm, failed to counteract iNOS induction as well as the reduced insulin secretion. In summary, our findings stress that IL-1beta-induced suppression of insulin secretion may be related to iNOS induction in beta cells and that RX can reverse this effect, by maintaining insulin secretion. Oppositely, the MnSODm is not able to restore IL-1beta-suppressed insulin secretion. Hence, imidazoline compounds may protect beta cells against damage caused by IL-1beta-induced free oxygen and nitrogen radicals.

  6. 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.

  7. Serum Cytokines as Biomarkers in Islet Cell Transplantation for Type 1 Diabetes.

    Science.gov (United States)

    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

    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 transplantation. Thirteen islet transplant patients were selected on basis of good graft function (reaching insulin independence) or insufficient engraftment (insulin requiring) from our cohort receiving standardized grafts and immune suppressive therapy. Patients reaching insulin independence were divided in those with continued (>12 months) versus transient (cytokines and adipokines was measured in sera taken before and at one year after transplantation using a validated multiplex immunoassay platform. Ninety serum proteins were detectable in concentrations varying markedly among patients at either time point. Thirteen markers changed after transplantation, while another seven markers changed in a clinical subpopulation. All other markers remained unaffected after transplantation under generalized immunosuppression. Patterns of cytokines could distinguish good graft function from insufficient function including IFN-α, LIF, SCF and IL-1RII before and after transplantation, by IL-16, CCL3, BDNF and M-CSF only before and by IL-22, IL-33, KIM-1, S100A12 and sCD14 after transplantation. Three other proteins (Leptin, Cathepsin L and S100A12) associated with loss of temporary graft function before or after transplantation. Distinct cytokine signatures could be identified in serum that predict or associate with clinical outcome. These serum markers may help guiding patient selection and choice of immunotherapy, or act as novel drug targets in islet transplantation.

  8. 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

    responsible for the staining. Human insulin cells were surface-labeled by monoclonal antibodies recognizing the mature secretory products, insulin and C-peptide but not with monoclonal antibodies specific for proinsulin. Thus, routing of unprocessed preproinsulin to the cell surface may not account......Human and rat insulin cells show insulin immunoreactivity, and glucagon cells show glucagon immunoreactivity on their membrane surfaces, respectively. The reaction occurs in the form of small dots on the islet cell surface and colocalizes with the chromogranin family of secretory granule markers...

  9. Transport of ascorbic acid and dehydroascorbic acid by pancreatic islet cells from neonatal rats

    DEFF Research Database (Denmark)

    Zhou, A; Farver, O; Thorn, N A

    1991-01-01

    .14.17.3). The enzyme needs ascorbic acid for activity as well as copper and molecular oxygen. The present work shows that pancreatic islet cells prepared from overnight cultures of isolated islets from 5-7-day-old rats accumulate 14C-labelled ascorbic acid by a Na(+)-dependent active transport mechanism which involves....... Dehydroascorbic acid was converted to ascorbic acid by an unknown mechanism after uptake. The uptake of both ascorbic acid and dehydroascorbic acid was inhibited by tri-iodothyronine, and uptake of ascorbic acid, but not of dehydroascorbic acid, was inhibited by glucocorticoids. Isolated secretory granules...... a saturable process (estimated Km 17.6 microM). Transport was inhibited by ouabain, phloridzin, cytochalasin B, amiloride and probenecid. Glucose inhibited or stimulated uptake, depending on the length of incubation time of the cells. The uptake of dehydroascorbic acid was linearly dependent on concentration...

  10. Idiopathic hyperammonemia in a patient with total pancreatectomy and islet cell transplantation.

    Science.gov (United States)

    Navaneethan, Udayakumar; Venkatesh, Preethi G K

    2010-11-09

    Idiopathic hyperammonemia is characterized by elevated serum ammonia associated with neurological deterioration of no other obvious etiology associated with relatively normal liver function tests and normal amino-acid levels. We report a case of a 32-year-old woman who presented with acute mental status changes with a pelvic abscess approximately a year following her total pancreatectomy and islet cell transplant surgery. Her ammonia level was elevated to 425 µg/dL. Traditional ammonia-reducing therapies were initiated, but proved ineffective. Metabolic, pharmacologic, microbial, and autoimmune causes for hyperammonemia were excluded. The patient ultimately required continuous veno-venous hemofiltration to decrease her ammonia. Ammonia levels decreased following continuous veno-venous hemofiltration and the patient's mental status gradually returned to baseline. Idiopathic hyperammonemia in the setting of total pancreatectomy and islet cell transplantation has not been reported before. We propose that malnutrition following total pancreatectomy resulting in repressed urea cycle enzyme synthesis may have predisposed for this hyperammonemia.

  11. Incidence of tubulostromal adenoma of the ovary in aged germ cell-deficient mice.

    Science.gov (United States)

    Duncan, M K; Chada, K K

    1993-07-01

    Female mice homozygous for the germ cell-deficient (gcd) mutation enter reproductive senescence prematurely due to a dearth of germ cells arising in embryonic development. The ovaries of young gcd/gcd animals are atrophic, composed of little more than stromal cells in a connective tissue matrix. By one year of age, 56 per cent of homozygotes have developed tubulostromal adenoma of the ovary while 100 per cent wild-type and heterozygous littermates are phenotypically normal. Since these animals develop ovarian tumours more frequently as a consequence of a single autosomal recessive mutation, they will be useful models for the study of ovarian neoplasia.

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

    Directory of Open Access Journals (Sweden)

    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.

  13. A case of gastric-type adenoma with chief cell and parietal cell differentiation surrounded by complete intestinal metaplasia.

    Science.gov (United States)

    Furukawa, Ryutaro; Oyama, Tsuneo; Takahashi, Akiko; Yorimitsu, Nobukazu; Shimoda, Tadakazu; Ota, Hiroyoshi; Shiozawa, Satoshi

    2017-01-01

    A man in his 70s received Helicobacter pylori eradication therapy after endoscopic submucosal dissection (ESD) of the stomach. A small, yellowish, protuberant lesion was later observed on the anterior wall of the lower body of the stomach on surveillance esophagogastroduodenoscopy. Narrow band imaging-magnified endoscopy showed an irregular pit and net-like vascular pattern, with the background mucosa having a light blue crest pattern. A biopsy was performed, which led to a diagnosis of adenoma with a gastric phenotype, so repeat ESD was performed. The freshly resected specimen showed a small, protuberant, flat lesion with a clear margin, and hematoxylin and eosin staining showed mild architectural and nuclear atypia. The shape of the atypical gland was similar to that of a fundic gland. MUC5AC, MUC6, pepsinogen A, and H(+)/K(+) ATPase expressions were positive, and CD10 expression was negative, indicating that this tumor could not only differentiate to mucous neck cells but also to chief cells, parietal cells and foveolar epithelium. Therefore, this 4-mm tumor was diagnosed as a type 0-IIa tubular adenoma with fundic gland differentiation. The background mucosa showed complete intestinal metaplasia. Traditionally, gastric-type adenoma has been defined as the pyloric gland-type, but our case had a fundic gland phenotype. Therefore, a new fundic-gland adenoma subtype should be considered in this case.

  14. Using the cost-effectiveness of allogeneic islet transplantation to inform induced pluripotent stem cell-derived β-cell therapy reimbursement.

    Science.gov (United States)

    Archibald, Peter R T; Williams, David J

    2015-11-01

    In the present study a cost-effectiveness analysis of allogeneic islet transplantation was performed and the financial feasibility of a human induced pluripotent stem cell-derived β-cell therapy was explored. Previously published cost and health benefit data for islet transplantation were utilized to perform the cost-effectiveness and sensitivity analyses. It was determined that, over a 9-year time horizon, islet transplantation would become cost saving and 'dominate' the comparator. Over a 20-year time horizon, islet transplantation would incur significant cost savings over the comparator (GB£59,000). Finally, assuming a similar cost of goods to islet transplantation and a lack of requirement for immunosuppression, a human induced pluripotent stem cell-derived β-cell therapy would dominate the comparator over an 8-year time horizon.

  15. Assessing tumor progression factors by somatic gene transfer into a mouse model: Bcl-xL promotes islet tumor cell invasion.

    Directory of Open Access Journals (Sweden)

    Yi-Chieh Nancy Du

    2007-10-01

    Full Text Available Tumors develop through multiple stages, implicating multiple effectors, but the tools to assess how candidate genes contribute to stepwise tumor progression have been limited. We have developed a novel system in which progression of phenotypes in a mouse model of pancreatic islet cell tumorigenesis can be used to measure the effects of genes introduced by cell-type-specific infection with retroviral vectors. In this system, bitransgenic mice, in which the rat insulin promoter (RIP drives expression of both the SV40 T antigen (RIP-Tag and the receptor for subgroup A avian leukosis virus (RIP-tva, are infected with avian viral vectors carrying cDNAs encoding candidate progression factors. Like RIP-Tag mice, RIP-Tag; RIP-tva bitransgenic mice develop isolated carcinomas by approximately 14 wk of age, after progression through well-defined stages that are similar to aspects of human tumor progression, including hyperplasia, angiogenesis, adenoma, and invasive carcinoma. When avian retroviral vectors carrying a green fluorescent protein marker were introduced into RIP-Tag; RIP-tva mice by intra-cardiac injection at the hyperplastic or early dysplastic stage of tumorigenesis, approximately 20% of the TVA-positive cells were infected and expressed green fluorescent proteins as measured by flow cytometry. Similar infection with vectors carrying cDNA encoding either of two progression factors, a dominant-negative version of cadherin 1 (dnE-cad or Bcl-xL, accelerated the formation of islet tumors with invasive properties and pancreatic lymph node metastasis. To begin studying the mechanism by which Bcl-xL, an anti-apoptotic protein, promotes invasion and metastasis, RIP-Tag; RIP-tva pancreatic islet tumor cells were infected in vitro with RCASBP-Bcl-xL. Although no changes were observed in rates of proliferation or apoptosis, Bcl-xL altered cell morphology, remodeled the actin cytoskeleton, and down-regulated cadherin 1; it also induced cell migration and

  16. Loss of β-Cell Identity Occurs in Type 2 Diabetes and Is Associated With Islet Amyloid Deposits

    NARCIS (Netherlands)

    Spijker, H. Siebe; Song, Heein; Ellenbroek, Johanne H.; Roefs, Maaike M.; Engelse, Marten A.; Bos, Erik; Koster, Abraham J.; Rabelink, Ton J.; Hansen, Barbara C.; Clark, Anne; Carlotti, Francoise; de Koning, Eelco J. P.

    Loss of pancreatic islet beta-cell mass and beta-cell dysfunction are central in the development of type 2 diabetes (T2DM). We recently showed that mature human insulin-containing beta-cells can convert into glucagon-containing alpha-cells ex vivo. This loss of beta-cell identity was characterized

  17. Loss of β-cell identity occurs in type 2 diabetes and is associated with islet amyloid deposits

    NARCIS (Netherlands)

    Spijker, H Siebe; Song, Heein; Ellenbroek, Johanne H; Roefs, Maaike M; Engelse, Marten A; Bos, Erik; Koster, Abraham J; Rabelink, Ton J; Hansen, Barbara C; Clark, Anne; Carlotti, Françoise; de Koning, Eelco J P

    2015-01-01

    Loss of pancreatic islet β-cell mass and β-cell dysfunction are central in the development of type 2 diabetes (T2DM). We recently showed that mature human insulin-containing β-cells can convert into glucagon-containing α-cells ex vivo. This loss of β-cell identity was characterized by the presence

  18. Total Pancreatectomy With Islet Cell Transplantation
for the Treatment of Pancreatic Cancer.

    Science.gov (United States)

    Parks, Lisa; Routt, Meghan

    2015-08-01

    Resection or removal of the pancreas causes loss of parenchyma, which can result in extreme disruption of glucose homeostasis and malabsorption of dietary nutrients. However, islet autotransplantation (IAT) may reduce or prevent the severity of pancreatogenic diabetes. This article explores total pancreatectomy with IAT within the context of pancreatic cancer treatment. At a Glance • The liver is the preferred site for implantation because of easy vascular access. • Following islet autotransplantation, the liver becomes an insulin-producing organ as the transplanted beta cells begin making insulin. • The most significant complication of implantation in the liver is portal vein occlusion because of thrombosis; consequently, a heparin drip is infused for the first seven days postoperatively to prevent portal vein thrombus formation.

  19. 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

    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......AIMS/HYPOTHESIS: Intra-islet and gut-islet crosstalk are critical in orchestrating basal and postprandial metabolism. The aim of this study was to identify regulatory proteins and receptors underlying somatostatin secretion though the use of transcriptomic comparison of purified murine alpha, beta...... rational drug design to target specific islet cell types. The present study indicates that ghrelin acts specifically on delta cells within pancreatic islets to elicit somatostatin secretion, which in turn inhibits insulin and glucagon release. This highlights a potential role for ghrelin in the control...

  20. Effect of co-culture of mesenchymal stem/stromal cells with pancreatic islets on viability and function outcomes: a systematic review and meta-analysis.

    Science.gov (United States)

    de Souza, Bianca Marmontel; Bouças, Ana Paula; Oliveira, Fernanda Dos Santos de; Reis, Karina Pires; Ziegelmann, Patrícia; Bauer, Andrea Carla; Crispim, Daisy

    2017-03-04

    The maintenance of viable and functional pancreatic islets is crucial for successful islet transplantation from brain-dead donors. To overcome islet quality loss during culture, some studies have co-cultured islets with mesenchymal stem/stromal cells (MSC). However, it is still uncertain if MSC-secreted factors are enough to improve islet quality or if a physical contact between MSCs and islets is needed. Therefore, we performed a systematic review and meta-analysis to clarify the effect of different culture contact systems of islets with MSCs on viability and insulin secretion outcomes. Pubmed and Embase were searched. Twenty studies fulfilled the eligibility criteria and were included in the qualitative synthesis and/or meta-analysis. For both outcomes, pooled weighted mean differences (WMD) between islet cultured alone (control group) and the co-culture condition were calculated. Viability mean was higher in islets co-cultured with MSCs compared with islet cultured alone [WMD = 18.08 (95% CI 12.59-23.57)]. The improvement in viability was higher in islets co-cultured in indirect or mixed contact with MSCs than in direct physical contact (P culture condition compared with islet cultured alone [WMD = 0.83 (95% CI 0.54-1.13)], independently of contact system. Results from the studies that were analyzed only qualitatively are in accordance with meta-analysis data. Co-culture of islets with MSCs has the potential for protecting islets from injury during culture period. Moreover, culture time appears to influence the beneficial effect of different methods of co-culture on viability and function of islets.

  1. Simultaneous detection of circulating autoreactive CD8+ T-cells specific for different islet cell-associated epitopes using combinatorial MHC multimers.

    Science.gov (United States)

    Velthuis, Jurjen H; Unger, Wendy W; Abreu, Joana R F; Duinkerken, Gaby; Franken, Kees; Peakman, Mark; Bakker, Arnold H; Reker-Hadrup, Sine; Keymeulen, Bart; Drijfhout, Jan Wouter; Schumacher, Ton N; Roep, Bart O

    2010-07-01

    Type 1 diabetes results from selective T-cell-mediated destruction of the insulin-producing beta-cells in the pancreas. In this process, islet epitope-specific CD8(+) T-cells play a pivotal role. Thus, monitoring of multiple islet-specific CD8(+) T-cells may prove to be valuable for measuring disease activity, progression, and intervention. Yet, conventional detection techniques (ELISPOT and HLA tetramers) require many cells and are relatively insensitive. Here, we used a combinatorial quantum dot major histocompatibility complex multimer technique to simultaneously monitor the presence of HLA-A2 restricted insulin B(10-18), prepro-insulin (PPI)(15-24), islet antigen (IA)-2(797-805), GAD65(114-123), islet-specific glucose-6-phosphatase catalytic subunit-related protein (IGRP)(265-273), and prepro islet amyloid polypeptide (ppIAPP)(5-13)-specific CD8(+) T-cells in recent-onset diabetic patients, their siblings, healthy control subjects, and islet cell transplantation recipients. Using this kit, islet autoreactive CD8(+) T-cells recognizing insulin B(10-18), IA-2(797-805), and IGRP(265-273) were shown to be frequently detectable in recent-onset diabetic patients but rarely in healthy control subjects; PPI(15-24) proved to be the most sensitive epitope. Applying the "Diab-Q-kit" to samples of islet cell transplantation recipients allowed detection of changes of autoreactive T-cell frequencies against multiple islet cell-derived epitopes that were associated with disease activity and correlated with clinical outcome. A kit was developed that allows simultaneous detection of CD8(+) T-cells reactive to multiple HLA-A2-restricted beta-cell epitopes requiring limited amounts of blood, without a need for in vitro culture, that is applicable on stored blood samples.

  2. Molecular Characterization of an Endometrial Endometrioid Adenocarcinoma Metastatic to a Thyroid Hürthle Cell Adenoma Showing Cancerization of Follicles.

    Science.gov (United States)

    Afrogheh, Amir H; Meserve, Emily; Sadow, Peter M; Stephen, Antonia E; Nosé, Vânia; Berlin, Suzanne; Faquin, William C

    2016-09-01

    Tumor-to-tumor metastasis is rare. Herein, we present a unique case of endometrial endometrioid adenocarcinoma metastatic to a thyroid Hürthle cell adenoma 9 years after initial diagnosis. On histologic examination of the thyroid, the malignant endometrioid glands and single cells (donor tumor) were dispersed within the Hürthle cell adenoma (recipient tumor). In several sections of the adenoma with still preserved microfollicular architecture, malignant endometrial adenocarcinoma cells were admixed within oncocytic adenomatous epithelium (so-called "cancerization of the follicles"). This unusual phenomenon, to our knowledge, is a novel finding in the thyroid gland. Immunohistochemistry, subsequently elicited clinical history, and morphologic comparison of the tumor in the thyroid to the primary endometrial tumor confirmed the origin of the donor tumor cells. Molecular analysis of both the metastatic and primary endometrial tumors demonstrated PIK3CA and PTEN mutations in both tumors, as is characteristic of well-differentiated endometrioid tumors of the endometrium. Amplification of chromosome 1q was detected in both sites; however, only the metastatic tumor showed loss of chromosomes 2, 9, and 22. The morphologic differential diagnosis of metastatic endometrioid adenocarcinoma in the thyroid includes columnar cell variant of papillary thyroid carcinoma (CCVPTC) arising in a preexisting adenoma, endocrine glandular atypia within an adenoma, and metastasis from other anatomic sites. Histomorphologic differences among these entities may be subtle; therefore, knowledge of and morphologic comparison with prior malignancies and immunohistochemistry can be helpful in rendering the correct diagnosis.

  3. Subclinical hyperfunctioning pituitary adenomas: The silent tumors

    Science.gov (United States)

    Cooper, Odelia; Melmed, Shlomo

    2012-01-01

    Pituitary adenomas are classified by function as defined by clinical symptoms and signs of hormone hypersecretion with subsequent confirmation on immunohistochemical staining. However, positive immunostaining for pituitary cell types has been shown for clinically nonfunctioning adenomas, and this entity is classified as silent functioning adenoma. Most common in these subtypes include silent gonadotroph adenomas, silent corticotroph adenomas and silent somatotroph adenomas. Less commonly, silent prolactinomas and thyrotrophinomas are encountered. Appropriate classification of these adenomas may affect follow-up care after surgical resection. Some silent adenomas such as silent corticotroph adenomas follow a more aggressive course, necessitating closer surveillance. Furthermore, knowledge of the immunostaining characteristics of silent adenomas may determine postoperative medical therapy. This article reviews the incidence, clinical behavior, and pathologic features of clinically silent pituitary adenomas. PMID:22863387

  4. The Ultrastructure of Secretory Cells of the Islets of Langerhans in South American Catfish Rhamdia quelen

    Directory of Open Access Journals (Sweden)

    Laura Luchini

    2015-01-01

    Full Text Available The present work shows that a detailed description of the ultrastructure of the secretory cells of the South American catfish Rhamdia quelen pancreatic islets is presented. Evidence is offered to support the contention that the α-granules consist of a central and an outer portion of different electron densities and solubilities, that the δ-cells are most probably morphologically altered but viable α-cells, and that the β-granules possibly possess a repeating substructure and may therefore represent an intracellular crystalline storage form of insulin.

  5. MicroRNA expression in alpha and beta cells of human pancreatic islets.

    Directory of Open Access Journals (Sweden)

    Dagmar Klein

    Full Text Available microRNAs (miRNAs play an important role in pancreatic development and adult β-cell physiology. Our hypothesis is based on the assumption that each islet cell type has a specific pattern of miRNA expression. We sought to determine the profile of miRNA expression in α-and β-cells, the main components of pancreatic islets, because this analysis may lead to a better understanding of islet gene regulatory pathways. Highly enriched (>98% subsets of human α-and β-cells were obtained by flow cytometric sorting after intracellular staining with c-peptide and glucagon antibody. The method of sorting based on intracellular staining is possible because miRNAs are stable after fixation. MiRNA expression levels were determined by quantitative high throughput PCR-based miRNA array platform screening. Most of the miRNAs were preferentially expressed in β-cells. From the total of 667 miRNAs screened, the Significant Analysis of Microarray identified 141 miRNAs, of which only 7 were expressed more in α-cells (α-miRNAs and 134 were expressed more in β-cells (β-miRNAs. Bioinformatic analysis identified potential targets of β-miRNAs analyzing the Beta Cell Gene Atlas, described in the T1Dbase, the web platform, supporting the type 1 diabetes (T1D community. cMaf, a transcription factor regulating glucagon expression expressed selectively in α-cells (TFα is targeted by β-miRNAs; miR-200c, miR-125b and miR-182. Min6 cells treated with inhibitors of these miRNAs show an increased expression of cMaf RNA. Conversely, over expression of miR-200c, miR-125b or miR-182 in the mouse alpha cell line αTC6 decreases the level of cMAF mRNA and protein. MiR-200c also inhibits the expression of Zfpm2, a TFα that inhibits the PI3K signaling pathway, at both RNA and protein levels.In conclusion, we identified miRNAs differentially expressed in pancreatic α- and β-cells and their potential transcription factor targets that could add new insights into different

  6. 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

  7. Pancreatic β-Cells Express the Fetal Islet Hormone Gastrin in Rodent and Human Diabetes.

    Science.gov (United States)

    Dahan, Tehila; Ziv, Oren; Horwitz, Elad; Zemmour, Hai; Lavi, Judith; Swisa, Avital; Leibowitz, Gil; Ashcroft, Frances M; In't Veld, Peter; Glaser, Benjamin; Dor, Yuval

    2017-02-01

    β-Cell failure in type 2 diabetes (T2D) was recently proposed to involve dedifferentiation of β-cells and ectopic expression of other islet hormones, including somatostatin and glucagon. Here we show that gastrin, a stomach hormone typically expressed in the pancreas only during embryogenesis, is expressed in islets of diabetic rodents and humans with T2D. Although gastrin in mice is expressed in insulin+ cells, gastrin expression in humans with T2D occurs in both insulin+ and somatostatin+ cells. Genetic lineage tracing in mice indicates that gastrin expression is turned on in a subset of differentiated β-cells after exposure to severe hyperglycemia. Gastrin expression in adult β-cells does not involve the endocrine progenitor cell regulator neurogenin3 but requires membrane depolarization, calcium influx, and calcineurin signaling. In vivo and in vitro experiments show that gastrin expression is rapidly eliminated upon exposure of β-cells to normal glucose levels. These results reveal the fetal hormone gastrin as a novel marker for reversible human β-cell reprogramming in diabetes. © 2017 by the American Diabetes Association.

  8. Sca1-positive murine pituitary adenoma cells show tumor growth advantage

    Science.gov (United States)

    Donangelo, Ines; Ren, Song-Guang; Eigler, Tamar; Svendsen, Clive; Melmed, Shlomo

    2014-01-01

    The role of tumor stem cells in benign tumors such as pituitary adenomas remains unclear. We investigated whether cells within pituitary adenomas that spontaneously develop in Rb+/− mice are hierarchically distributed with a subset being responsible for tumor growth. Cells derived directly from such tumors grew as spheres in serum-free culture medium supplemented with EGF and bFGF. Some cells within growing pituitary tumor spheres (PTS) expressed common stem cell markers (Sca1, Sox2, Nestin, CD133), but were devoid of hormone-positive differentiated cells. Under subsequent differentiating conditions (matrigel-coated growth surface), PTS expressed all six pituitary hormones. We next searched for specific markers of the stem cell population and isolated a Sca1+ cell population that showed increased sphere formation potential, lower hormone mRNA expression, higher expression of stem cell markers (Notch1, Sox2, Nestin), and increased proliferation rates. When transplanted into NOD scid gamma mice brains, Sca1+ pituitary tumor cells exhibited higher rates of tumor formation (brain tumors observed in 11/11 [100%] vs. 7/12 [54%] of mice transplanted with Sca1+ and Sca1− cells, respectively). Magnetic resonance imaging and histological analysis of brain tumors showed that those derived from Sca1+ pituitary tumor cells were also larger and plurihormonal. Our findings show that Sca1+ cells derived from benign pituitary tumors exhibit an undifferentiated expression profile and tumor proliferative advantages, and we propose that they could represent putative pituitary tumor stem/progenitor cells. PMID:24481638

  9. 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.

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

    Science.gov (United States)

    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.

  11. Adenomas broncopulmonares

    Directory of Open Access Journals (Sweden)

    Vítor Sousa

    2004-05-01

    Full Text Available RESUMO: Os adenomas do tipo das glândulas salivares juntamente com os papilomas são os tumores benignos que surgem ocupando o lúmen ou a parede da árvore brônquica. O adenoma alveolar e o adenoma papilar são mais frequentemente observados no parênquima periférico, embora todos estes tumores sejam muito raros e diagnosticados incidentalmente.Apresentando-se como nódulos solitários nos adultos com mais de 45 anos, são facilmente reconhecidos pela sua morfologia, mas o adenoma alveolar é de difícil interpretação num exame intra-operatório.Dois casos, de adenoma pleomórfico e de adenoma alveolar, são apresentados, e faz-se revisão da literatura.REV PORT PNEUMOL 2004; X (3: 235-243 ABSTRACT: Adenomas of solitary gland type together with papillomas are the true benign tumours in or arround the bronchial tree. Alveolar adenoma and papillary adenoma are more frequently observed in peripheral parenchime although this group of tumours is very rare and often incidentally diagnosed.Presenting usually as solitary nodules in adults after 45 years, are easily recognized because of distinct morphology but alveolar adenomas may be difficult to evaluate in frozen sections.Two cases of pleomorphic adenoma and alveolar adenoma are presented and a review of literature is made.REV PORT PNEUMOL 2004; X (3: 235-243 Palavras-chave: pulmão, brônquio, adenoma, Key-words: lung, bronchi, adenoma

  12. 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.

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

    Science.gov (United States)

    ... Types Bladder Cancer Breast Cancer Colorectal Cancer Kidney (Renal Cell) Cancer Leukemia Liver Cancer Lung Cancer Lymphoma Pancreatic Cancer Prostate Cancer Skin Cancer Thyroid Cancer Uterine Cancer All ...

  14. Caveolin-1 sensitizes rat pituitary adenoma GH3 cells to bromocriptine induced apoptosis

    Directory of Open Access Journals (Sweden)

    Huang Mu-Chiou

    2007-03-01

    Full Text Available Abstract Background Prolactinoma is the most frequent pituitary tumor in humans. The dopamine D2 receptor agonist bromocriptine has been widely used clinically to treat human breast tumor and prolactinoma through inhibition of hyperprolactinemia and induction of tumor cell apoptosis, respectively, but the molecular mechanism of bromocriptine induction of pituitary tumor apoptosis remains unclear. Caveolin-1 is a membrane-anchored protein enriched on caveolae, inverted flask-shaped invaginations on plasma membranes where signal transduction molecules are concentrated. Currently, caveolin-1 is thought to be a negative regulator of cellular proliferation and an enhancer of apoptosis by blocking signal transduction between cell surface membrane receptors and intracellular signaling protein cascades. Rat pituitary adenoma GH3 cells, which express endogenous caveolin-1, exhibit increased apoptosis and shrinkage after exposure to bromocriptine. Hence, the GH3 cell line is an ideal model for studying the molecular action of bromocriptine on prolactinoma. Results The expression of endogenous caveolin-1 in GH3 cells was elevated after bromocriptine treatment. Transiently expressed mouse recombinant caveolin-1 induced apoptosis in GH3 cells by enhancing the activity of caspase 8. Significantly, caveolin-1 induction of GH3 cell apoptosis was sensitized by the administration of bromocriptine. Phosphorylation of caveolin-1 at tyrosine 14 was enhanced after bromocriptine treatment, suggesting that bromocriptine-induced phosphorylation of caveolin-1 may contribute to sensitization of apoptosis in GH3 cells exposed to bromocriptine. Conclusion Our results reveal that caveolin-1 increases sensitivity for apoptosis induction in pituitary adenoma GH3 cells and may contribute to tumor shrinkage after clinical bromocriptine treatment.

  15. Effect of Wnt Signaling on the Differentiation of Islet β-Cells from Adipose-Derived Stem Cells

    Directory of Open Access Journals (Sweden)

    Hefei Wang

    2017-01-01

    Full Text Available The Wnt signaling is critical for pancreatic development and islet function; however, its precise effects on the development and function of the β-cells remain controversial. Here we examined mRNA and protein expression of components of the Wnt signaling throughout the differentiation of islet β-cells from adipose-derived stem cells (ADSCs. After induction, ADSCs expressed markers of β-cells, including the insulin, PDX1, and glucagon genes, and the PDX1, CK19, nestin, insulin, and C-peptide proteins, indicating their successful differentiation. Compared with pancreatic adult stem cells (PASCs, the quantities of insulin, GLUT2, and Irs2 mRNA decreased, whereas Gcg, Gck, and Irs1 mRNA increased. Over time, during differentiation, insulin mRNA and protein expression increased, Gcg and Gck mRNA expression increased, Irs1 mRNA expression decreased and then increased, and Irs2 mRNA increased and then decreased (all P0.05. Our results indicate that the Wnt signaling is activated during ADSC differentiation into islet β-cells, but there was no obvious enrichment of nonphosphorylated β-catenin protein.

  16. Clinical pancreatic islet transplantation.

    Science.gov (United States)

    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.

  17. Fibrosis and Mast Cells in Colorectal Lesions: Significance in Adenoma-Colorectal Cancer Sequence and Association with Diet.

    Science.gov (United States)

    Alves, Izabela Sinara Silva; Coser, Pedro Henrique Piras; Loureiro, Giovanni José Zucoloto; Nogueira da Gama, Luciano Pinto; Ribeiro, Flavya da Silva Souza; Bautz, Willian Grassi; Coburn, Karla Loureiro Almeida; Pacheco, Marcos da Silva; da Gama de Souza, Letícia Nogueira

    2016-09-01

    Adenoma is the most common benign neoplasm with potential to progress into colorectal cancer (CRC), a disease responsible for high rates of mortality. However, it is not possible yet to establish which lesions will evolve into CRC. We aimed to investigate the intrinsic factors, diet profile, and microenvironment as factors involved in adenoma-CRC progression. We evaluated nutritional profile and microscopic features. Adenomas and CRC lesions were stained with Mallory's trichrome to reveal fibrosis and Alcian blue to identify mast cells. A total of 143 patients was selected, 66 % diagnosed with normal mucosa, 28.4 % with benign lesion, and 5.6 % with CRC. A higher frequency of lesions was associated with patients older than 50 years (26.57 %) and women (18.18 %), but men were more likely to develop CRC. Regarding microscopic aspects, epithelium-connective tissue interface with disorganization feature was significantly higher in CRC when compared to adenoma (P = 0.0007). A greater fibrosis around vessels was also observed in CRC (P = 0.01). The statistical analysis indicated a significant correlation between mast cell population and patients older than 50 years (P diet profile, and microscopic features in colorectal lesions was observed, with a progressive change in the microenvironment during adenoma-CRC sequence.

  18. 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...

  19. Preganglionic innervation of the pancreas islet cells in the rat

    NARCIS (Netherlands)

    LUITEN, PGM; TERHORST, GJ; KOOPMANS, SJ; RIETBERG, M; STEFFENS, AB

    1984-01-01

    The position and number of preganglionic somata innervating the insulin-secreting β-cells of the endocrine pancreas were investigated in Wistar rats. This question was approached by comparing the innervation of the pancreas of normal rats with the innervation of the pancreas in alloxan-induced

  20. Role of PI3K p110β in the differentiation of human embryonic stem cells into islet-like cells.

    Science.gov (United States)

    Mao, Gen-Hong; Lu, Ping; Wang, Ya-Nan; Tian, Chen-Guang; Huang, Xiao-Hui; Feng, Zong-Gang; Zhang, Jin-Lan; Chang, Hong-Yang

    2017-06-17

    To investigate the effects of the PI3K inhibitors on the differentiation of insulin-producing cells derived from human embryonic stem cells. Here, we report that human embryonic stem cells induced by phosphatidylinositol-3-kinase (PI3K) p110β inhibitors could produce more mature islet-like cells. Findings were validated by immunofluorescence analysis, quantitative real-time PCR, insulin secretion in vitro and cell transplantation for the diabetic SCID mice. Immunofluorescence analysis revealed that unihormonal insulin-positive cells were predominant in cultures with rare polyhormonal cells. Real-time PCR data showed that islet-like cells expressed key markers of pancreatic endocrine hormones and mature pancreatic β cells including MAFA. Furthermore, this study showed that the expression of most pancreatic endocrine hormones was similar between groups treated with the LY294002 (nonselective PI3K inhibitor) and TGX-221 (PI3K isoform selective inhibitors of class 1β) derivatives. However, the level of insulin mRNA in TGX-221-treated cells was significantly higher than that in LY294002-treated cells. In addition, islet-like cells displayed glucose-stimulated insulin secretion in vitro. After transplantation, islet-like cells improved glycaemic control and ameliorated the survival outcome in diabetic mice. This study demonstrated an important role for PI3K p110β in regulating the differentiation and maturation of islet-like cells derived from human embryonic stem cells. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Construction of functional pancreatic artificial islet tissue composed of fibroblast-modified polylactic- co-glycolic acid membrane and pancreatic stem cells.

    Science.gov (United States)

    Liu, Liping; Tan, Jing; Li, Baoyuan; Xie, Qian; Sun, Junwen; Pu, Hongli; Zhang, Li

    2017-09-01

    Objective To improve the biocompatibility between polylactic- co-glycolic acid membrane and pancreatic stem cells, rat fibroblasts were used to modify the polylactic- co-glycolic acid membrane. Meanwhile, we constructed artificial islet tissue by compound culturing the pancreatic stem cells and the fibroblast-modified polylactic- co-glycolic acid membrane and explored the function of artificial islets in diabetic nude mice. Methods Pancreatic stem cells were cultured on the fibroblast-modified polylactic- co-glycolic acid membrane in dulbecco's modified eagle medium containing activin-A, β-catenin, and exendin-4. The differentiated pancreatic stem cells combined with modified polylactic- co-glycolic acid membrane were implanted subcutaneously in diabetic nude mice. The function of artificial islet tissue was explored by detecting blood levels of glucose and insulin in diabetic nude mice. Moreover, the proliferation and differentiation of pancreatic stem cells on modified polylactic- co-glycolic acid membrane as well as the changes on the tissue structure of artificial islets were investigated by immunofluorescence and haematoxylin and eosin staining. Results The pancreatic stem cells differentiated into islet-like cells and secreted insulin when cultured on fibroblast-modified polylactic- co-glycolic acid membrane. Furthermore, when the artificial islet tissues were implanted into diabetic nude mice, the pancreatic stem cells combined with polylactic- co-glycolic acid membrane modified by fibroblasts proliferated, differentiated, and secreted insulin to reduce blood glucose levels in diabetic nude mice. Conclusion Pancreatic stem cells can be induced to differentiate into islet-like cells in vitro. In vivo, the artificial islet tissue can effectively regulate the blood glucose level in nude mice within a short period. However, as time increased, the structure of the artificial islets was destroyed due to the erosion of blood cells that resulted in the gradual

  2. Dimethyl fumarate protects pancreatic islet cells and non-endocrine tissue in L-arginine-induced chronic pancreatitis.

    Directory of Open Access Journals (Sweden)

    Lourdes Robles

    Full Text Available Chronic pancreatitis (CP is a progressive disorder resulting in the destruction and fibrosis of the pancreatic parenchyma which ultimately leads to impairment of the endocrine and exocrine functions. Dimethyl Fumarate (DMF was recently approved by FDA for treatment of patients with multiple sclerosis. DMF's unique anti-oxidant and anti-inflammatory properties make it an interesting drug to test on other inflammatory conditions. This study was undertaken to determine the effects of DMF on islet cells and non-endocrine tissue in a rodent model of L-Arginine-induced CP.Male Wistar rats fed daily DMF (25 mg/kg or vehicle by oral gavage were given 5 IP injections of L-Arginine (250 mg/100 g × 2, 1 hr apart. Rats were assessed with weights and intra-peritoneal glucose tolerance tests (IPGTT, 2 g/kg. Islets were isolated and assessed for islet mass and viability with flow cytometry. Non-endocrine tissue was assessed for histology, myeloperoxidase (MPO, and lipid peroxidation level (MDA. In vitro assessments included determination of heme oxygenase (HO-1 protein expression by Western blot.Weight gain was significantly reduced in untreated CP group at 6 weeks. IPGTT revealed significant impairment in untreated CP group and its restoration with DMF therapy (P <0.05. Untreated CP rats had pancreatic atrophy, severe acinar architectural damage, edema, and fatty infiltration as well as elevated MDA and MPO levels, which were significantly improved by DMF treatment. After islet isolation, the volume of non-endocrine tissue was significantly smaller in untreated CP group. Although islet counts were similar in the two groups, islet viability was significantly reduced in untreated CP group and improved with DMF treatment. In vitro incubation of human pancreatic tissue with DMF significantly increased HO-1 expression.Administration of DMF attenuated L-Arginine-induced CP and islet function in rats. DMF treatment could be a possible strategy to improve clinical

  3. Mangiferin Facilitates Islet Regeneration and β-Cell Proliferation through Upregulation of Cell Cycle and β-Cell Regeneration Regulators

    Directory of Open Access Journals (Sweden)

    Hai-Lian Wang

    2014-05-01

    Full Text Available Mangiferin, a xanthonoid found in plants including mangoes and iris unguicularis, was suggested in previous studies to have anti-hyperglycemic function, though the underlying mechanisms are largely unknown. This study was designed to determine the therapeutic effect of mangiferin by the regeneration of β-cells in mice following 70% partial pancreatectomy (PPx, and to explore the mechanisms of mangiferin-induced β-cell proliferation. For this purpose, adult C57BL/6J mice after 7–14 days post-PPx, or a sham operation were subjected to mangiferin (30 and 90 mg/kg body weight or control solvent injection. Mangiferin-treated mice exhibited an improved glycemia and glucose tolerance, increased serum insulin levels, enhanced β-cell hyperplasia, elevated β-cell proliferation and reduced β-cell apoptosis. Further dissection at the molecular level showed several key regulators of cell cycle, such as cyclin D1, D2 and cyclin-dependent kinase 4 (Cdk4 were significantly up-regulated in mangiferin-treated mice. In addition, critical genes related to β-cell regeneration, such as pancreatic and duodenal homeobox 1 (PDX-1, neurogenin 3 (Ngn3, glucose transporter 2 (GLUT-2, Forkhead box protein O1 (Foxo-1, and glucokinase (GCK, were found to be promoted by mangiferin at both the mRNA and protein expression level. Thus, mangiferin administration markedly facilitates β-cell proliferation and islet regeneration, likely by regulating essential genes in the cell cycle and the process of islet regeneration. These effects therefore suggest that mangiferin bears a therapeutic potential in preventing and/or treating the diabetes.

  4. A lectin microarray study of glycoantigens in neonatal porcine islet-like cell clusters.

    Science.gov (United States)

    Maeda, Akira; Ueno, Takehisa; Nakatsu, Shino; Wang, Dandan; Usui, Noriaki; Takeishi, Shunsaku; Okitsu, Teru; Goto, Masafumi; Nagashima, Hiroshi; Miyagawa, Shuji

    2013-07-01

    Besides α-Gal expression, the differences of glycosylation and antigenicity between adult pig islets (APIs) and neonatal porcine islet-like cell clusters (NPCCs) are altogether unclear. In this study, lectin microarray analyses of NPCCs were performed and the results compared with the corresponding values for wild-type APIs and NPCCs from α-Gal transferase knockout (GalT-KO) pig. NPCCs were isolated from 1-3-d-old neonatal wild-type pigs and cultured for 1 d, 5 d, and 9 d, using a previously described technique. Alternatively, the isoration of APIs were isolated based on the method for human islets. In a comparison between NPCCs and APIs, all of the NPCCs showed higher signals for Sambucus nigra, Sambucus sieboldiana, and Trichosanthes japonica I and the binding of α2,6 sialc acid, whereas the APIs showed stronger signals for Lotus tetragonolobus, Aleuria aurantia, Narcissus pseudonarcissus, and Galanthus nivalis, suggesting that APIs contain high levels of high-mannose forms. Among the NPCCs, NPCC (day1) appeared to be richer than the others in Lotus tetragonolobus, Narcissus pseudonarcissus, Galanthus nivalis, and Urtica dioica, implying the presence of high-mannose forms. However, as a whole, the signals for many lectins for NPCCs were very similar. The NPCCs from a GalT-KO pig indicated not only the downregulation of α-Gal expression but α-GalNAc as well, and α2-6 sialic acid was upregulated. The results reported herein contain useful information for the future production of immunomodified pigs with less antigenicity than GalT-KO pigs toward clinical applications of NPCCs. Copyright © 2013. Published by Elsevier Inc.

  5. Histomorphological and morphometric studies of the pancreatic islet cells of diabetic rats treated with extracts of Annona muricata.

    Science.gov (United States)

    Adeyemi, D O; Komolafe, O A; Adewole, O S; Obuotor, E M; Abiodun, A A; Adenowo, T K

    2010-05-01

    Microanatomical changes in the pancreatic islet cells of streptozotocin induced diabetic Wistar rats were studied after treatment with methanolic extracts of Annona muricata leaves. Thirty adult Wistar rats were randomly assigned into three groups (control, untreated diabetic group, and A. muricata-treated diabetic group) of ten rats each. Diabetes mellitus was experimentally induced in groups B and C by a single intra-peritoneal injection of 80 mg/kg streptozotocin dissolved in 0.1 M citrate buffer. The control rats were intraperitoneally injected with an equivalent volume of citrate buffer. Daily intra peritoneal injections of 100 mg/kg A. muricata were administered to group C rats for two weeks. Post sacrifice the pancreases of the rats were excised and fixed in Bouin's fluid. The tissues were processed for paraffin embedding and sections of 5 mum thickness were produced and stained with H & E, Gomori aldehyde fuchsin, and chrome alum haematoxylin-phloxine for demonstration of the beta-cells of islets of pancreatic islets. Histomorphological and morphometric examination of the stained pancreatic sections showed a significant increase in the number, diameter, and volume of the beta-cells of pancreatic islets of the A. muricata-treated group (5.67 +/- 0.184 N/1000 mum(2), 5.38 +/- 0.093 mum and 85.12 +/- 4.24 mum(3), respectively) when compared to that of the untreated diabetic group of rats (2.85 +/- 0.361 N/1000 mum(2), 2.85 +/- 0.362 mum and 69.56 +/- 5.216 mum(3), respectively). The results revealed regeneration of the beta-cells of islets of pancreatic islet of rats treated with extract of A. muricata.

  6. Functional proteomics screen enables enrichment of distinct cell types from human pancreatic islets.

    Directory of Open Access Journals (Sweden)

    Revital Sharivkin

    Full Text Available The current world-wide epidemic of diabetes has prompted attempts to generate new sources of insulin-producing cells for cell replacement therapy. An inherent challenge in many of these strategies is the lack of cell-surface markers permitting isolation and characterization of specific cell types from differentiating stem cell populations. Here we introduce an iterative proteomics procedure allowing tag-free isolation of cell types based on their function. Our method detects and associates specific cell-surface markers with particular cell functionality by coupling cell capture on antibody arrays with immunofluorescent labeling. Using this approach in an iterative manner, we discovered marker combinations capable of enriching for discrete pancreatic cell subtypes from human islets of Langerhans: insulin-producing beta cells (CD9high/CD56+, glucagon-producing alpha cells (CD9-/CD56+ and trypsin-producing acinar cells (CD9-/CD56-. This strategy may assist future beta cell research and the development of diagnostic tools for diabetes. It can also be applied more generally for function-based purification of desired cell types from other limited and heterogeneous biological samples.

  7. Patient satisfaction and cost-effectiveness following total pancreatectomy with islet cell transplantation for chronic pancreatitis.

    Science.gov (United States)

    Garcea, Giuseppe; Pollard, Cristina A; Illouz, Severine; Webb, M'Balu; Metcalfe, Matthew S; Dennison, Ashley R

    2013-03-01

    Chronic pancreatitis (CP) results in an extremely poor quality of life and substantially increases health care utilization. Few data exist regarding the cost-effectiveness of surgical treatment for CP. This article examined the cost-effectiveness of total pancreatectomy (TP) with islet cell autotransplantation (IAT) for CP. Sixty patients undergoing TP + IAT and 37 patients undergoing TP were identified. Surgery resulted in significant reduction in opiate use, frequency of hospital admissions, and length of stay as well as visual analog scale scores for pain. Total pancreatectomy + IAT resulted in longer survival than TP alone (16.6 vs 12.9 years); 21.6% of patients with TP + IAT were insulin-independent, and those requiring insulin have reduced daily requirements compared with those having TP alone (22 vs 35 IU). The cost of TP + IAT with attendant admission and analgesia costs over the 16-year survival period was £110,445 compared with £101,608 estimated 16-year costs if no TP + IAT was undertaken. Total pancreatectomy + IAT is effective in improving pain and reducing analgesia. Islet cell transplantation offers the chance of insulin independence and results in lower insulin requirements, as well as conferring a survival advantage when compared with TP alone. Total pancreatectomy + IAT is cost-neutral when compared with nonsurgical or segmental surgical therapy.

  8. Hypoxia-inducible factor-1α regulates β cell function in mouse and human islets

    Science.gov (United States)

    Cheng, Kim; Ho, Kenneth; Stokes, Rebecca; Scott, Christopher; Lau, Sue Mei; Hawthorne, Wayne J.; O’Connell, Philip J.; Loudovaris, Thomas; Kay, Thomas W.; Kulkarni, Rohit N.; Okada, Terumasa; Wang, Xiaohui L.; Yim, Sun Hee; Shah, Yatrik; Grey, Shane T.; Biankin, Andrew V.; Kench, James G.; Laybutt, D. Ross; Gonzalez, Frank J.; Kahn, C. Ronald; Gunton, Jenny E.

    2010-01-01

    Hypoxia-inducible factor-1α (HIF-1α) is a transcription factor that regulates cellular stress responses. While the levels of HIF-1α protein are tightly regulated, recent studies suggest that it can be active under normoxic conditions. We hypothesized that HIF-1α is required for normal β cell function and reserve and that dysregulation may contribute to the pathogenesis of type 2 diabetes (T2D). Here we show that HIF-1α protein is present at low levels in mouse and human normoxic β cells and islets. Decreased levels of HIF-1α impaired glucose-stimulated ATP generation and β cell function. C57BL/6 mice with β cell–specific Hif1a disruption (referred to herein as β-Hif1a-null mice) exhibited glucose intolerance, β cell dysfunction, and developed severe glucose intolerance on a high-fat diet. Increasing HIF-1α levels by inhibiting its degradation through iron chelation markedly improved insulin secretion and glucose tolerance in control mice fed a high-fat diet but not in β-Hif1a-null mice. Increasing HIF-1α levels markedly increased expression of ARNT and other genes in human T2D islets and improved their function. Further analysis indicated that HIF-1α was bound to the Arnt promoter in a mouse β cell line, suggesting direct regulation. Taken together, these findings suggest an important role for HIF-1α in β cell reserve and regulation of ARNT expression and demonstrate that HIF-1α is a potential therapeutic target for the β cell dysfunction of T2D. PMID:20440072

  9. Experimental microencapsulation of porcine and rat pancreatic islet cells with air-driven droplet generator and alginate.

    Science.gov (United States)

    Koo, S K; Kim, S C; Wee, Y M; Kim, Y H; Jung, E J; Choi, M Y; Park, Y H; Park, K T; Lim, D G; Han, D J

    2008-10-01

    Transplantation of microencapsulated islets is proposed as an ideal therapy for the treatment of type 1 diabetes mellitus without immunosuppression. This strategy is based on the principle that foreign cells are protected from the host immune system by an artificial membrane. The aim of this study was to establish an ideal condition of microencapsulation using an air-driven droplet generator and alginate in vitro. The optimal conditions for islet encapsulation were an alginate inflow rate of 10 mL/h, CO2 flow rate of 2.0 L/min in a concentration of 2% alginate. For 2.5% alginate, the alginate inflow rate of 20 mL/h, CO2 flow rate 3.0 L/min was ideal; alginate inflow rate of 40 mL/h, CO2 flow rate of 4.0 L/min showed good microcapsules at 3% alginate. Viability of encapsulated islets was greater than 90%. In terms of insulin secretion, encapsulated islets secreted insulin in response to glucose in static culture medium. However, there was no normal response to low or high glucose challenge with a stimulation index less than 2.0. Microencapsulation of pig islets was successfully performed with air-driven droplet generator and alginate in vitro. Further studies about biocompatibility and glucose control in vivo may provide a useful tool for treatment of patients with diabetes mellitus.

  10. The role of alloresponsive Ly49⁺ NK cells in rat islet allograft failure in the presence and absence of cytomegalovirus

    NARCIS (Netherlands)

    Smelt, Maaike J.; Faas, Marijke M.; de Haan, Bart J.; de Haan, Aalzen; Vaage, John T.; de Vos, Paul

    2014-01-01

    There are still many factors to discover to explain the low success rates of islet allografts. In this study we demonstrate that specific subpopulations of alloreactive NK-cells may be involved in failure of islet allografts. By performing allotransplantation in rats (n = 13) we observed peripheral

  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 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. Islet formation in mice and men: lessons for the generation of functional insulin-producing β-cells from human pluripotent stem cells.

    Science.gov (United States)

    Nair, Gopika; Hebrok, Matthias

    2015-06-01

    The Islets of Langerhans are crucial 'micro-organs' embedded in the glandular exocrine pancreas that regulate nutrient metabolism. They not only synthesize, but also secrete endocrine hormones in a modulated fashion in response to physiologic metabolic demand. These highly sophisticated structures with intricate organization of multiple cell types, namely endocrine, vascular, neuronal and mesenchymal cells, have evolved to perform this task to perfection over time. Not surprisingly, islet architecture and function are dissimilar between humans and typically studied model organisms, such as rodents and zebrafish. Further, recent findings also suggest noteworthy differences in human islet development from that in mouse, including delayed appearance and gradual resolution of key differentiation markers, a single-phase of endocrine differentiation, and prenatal association of developing islets with neurovascular milieu. In light of these findings, it is imperative that a systematic study is undertaken to compare islet development between human and mouse. Illuminating inter-species differences in islet development will likely be critical in furthering our pursuit to generate an unlimited supply of truly functional and fully mature β-cells from human pluripotent stem cell (hPSC) sources for therapeutic purposes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Genetically modified human bone marrow derived mesenchymal stem cells for improving the outcome of human islet transplantation.

    Directory of Open Access Journals (Sweden)

    Vaibhav Mundra

    Full Text Available The objective of this study was to determine the potential of human bone marrow derived mesenchymal stem cells (hBMSCs as gene carriers for improving the outcome of human islet transplantation. hBMSCs were characterized for the expression of phenotypic markers and transduced with Adv-hVEGF-hIL-1Ra to overexpress human vascular endothelial growth factor (hVEGF and human interleukin-1 receptor antagonist (hIL-1Ra. Human islets were co-cultured with hBMSCs overexpressing hVEGF and hIL-1Ra. Islet viability was determined by membrane fluorescent method and glucose stimulation test. Transduced hBMSCs and human islets were co-transplanted under the kidney capsule of NOD.Cg-Prkdc(scid Il2rg(tm1Wjl /SzJ (NSG diabetic mice and blood glucose levels were measured over time to demonstrate the efficacy of genetically modified hBMSCs. At the end of study, immunofluorescent staining of kidney section bearing islets was performed for insulin and von Willebrand Factor (vWF. hBMSCs were positive for the expression of CD73, CD90, CD105, CD146 and Stro-1 surface markers as determined by flow cytometry. Transduction of hBMSCs with adenovirus did not affect their stemness and differentiation potential as confirmed by mRNA levels of stem cell markers and adipogenic differentiation of transduced hBMSCs. hBMSCs were efficiently transduced with Adv-hVEGF-hIL-1Ra to overexpress hVEGF and hIL-1Ra. Live dead cell staining and glucose stimulation test have shown that transduced hBMSCs improved the viability of islets against cytokine cocktail. Co-transplantation of human islets with genetically modified hBMSCs improved the glycemic control of diabetic NSG mice as determined by mean blood glucose levels and intraperitoneal glucose tolerance test. Immunofluorescent staining of kidney sections was positive for human insulin and vWF. In conclusion, our results have demonstrated that hBMSCs may be used as gene carriers and nursing cells to improve the outcome of islet

  14. Neutralizing Th2 Inflammation in Neonatal Islets Prevents β-Cell Failure in Adult IUGR Rats

    Science.gov (United States)

    Jaeckle Santos, Lane J.; Li, Changhong; Doulias, Paschalis-Thomas; Ischiropoulos, Harry; Worthen, G. Scott; Simmons, Rebecca A.

    2014-01-01

    Intrauterine growth restriction (IUGR) leads to development of type 2 diabetes (T2D) in adulthood. The mechanisms underlying this phenomenon have not been fully elucidated. Inflammation is associated with T2D; however, it is unknown whether inflammation is causal or secondary to the altered metabolic state. Here we show that the mechanism by which IUGR leads to the development of T2D in adulthood is via transient recruitment of T-helper 2 (Th) lymphocytes and macrophages in fetal islets resulting in localized inflammation. Although this immune response is short-lived, it results in a permanent reduction in islet vascularity and impaired insulin secretion. Neutralizing interleukin-4 antibody therapy given only in the newborn period ameliorates inflammation and restores vascularity and β-cell function into adulthood, demonstrating a novel role for Th2 immune responses in the induction and progression of T2D. In the neonatal stage, inflammation and vascular changes are reversible and may define an important developmental window for therapeutic intervention to prevent adult-onset diabetes. PMID:24408314

  15. Unacylated ghrelin and obestatin increase islet cell mass and prevent diabetes in streptozotocin-treated newborn rats.

    Science.gov (United States)

    Granata, Riccarda; Volante, Marco; Settanni, Fabio; Gauna, Carlotta; Ghé, Corrado; Annunziata, Marta; Deidda, Barbara; Gesmundo, Iacopo; Abribat, Thierry; van der Lely, Aart-Jan; Muccioli, Giampiero; Ghigo, Ezio; Papotti, Mauro

    2010-07-01

    The ghrelin gene products, namely acylated ghrelin (AG), unacylated ghrelin (UAG), and obestatin (Ob), were shown to prevent pancreatic beta-cell death and to improve beta-cell function under treatment with cytokines, which are major cause of beta-cell destruction in diabetes. Moreover, AG had been described previously to prevent streptozotocin (STZ)-induced diabetes in rats; however, the effect of either UAG or Ob has never been examined in this context. In the present study, we investigated the potential of UAG and Ob to increase islet beta-cell mass and to reduce diabetes at adult age in STZ-treated neonatal rats. One-day-old rats were injected with STZ and subsequently administered with either AG, UAG or Ob for 7 days. On day 70, plasma glucose levels, plasma and pancreatic insulin levels, pancreatic islet area and number, insulin and pancreatic/duodenal homeobox-1 (Pdx1) gene expression, and antiapoptotic BCL2 protein expression were determined. Similarly to AG, both UAG and Ob counteracted STZ-induced high glucose levels and improved plasma and pancreatic insulin levels, which were reduced by the diabetogenic compound. UAG and Ob increased islet area, islet number, and beta-cell mass with respect to STZ treatment alone. Finally, in STZ-treated animals, UAG and Ob up-regulated insulin and Pdx1 mRNA and increased the expression of BCL2 similarly to AG. Taken together, our results suggest that in STZ-treated newborn rats, UAG and Ob improve glucose metabolism and preserve islet cell mass, granting a therapeutic potential in medical conditions associated with impaired beta-cell function.

  16. Value of antibodies to GAD65 combined with islet cell cytoplasmic antibodies for predicting IDDM in a childhood population

    NARCIS (Netherlands)

    H-J. Aanstoot (Henk-Jan); E. Sigurdsson (Engilbert); M. Jaffe (M.); Y. Shi (Yuhui); S. Christgau (S.); D.E. Grobbee (Diederick); G.J. Bruining; J.L. Molenaar (J.); A. Hofman (Albert); S. Baekkeskov (S.)

    1994-01-01

    textabstractThe value of a test for islet cell cytoplasmic antibodies together with a test for GAD65 antibodies to predict the subsequent development of diabetes over a period of 11.5 years was assessed in an open childhood population comprising 2,805 individuals. A single serum sample was obtained

  17. 5-ALA Fluorescence in Native Pituitary Adenoma Cell Lines: Resection Control and Basis for Photodynamic Therapy (PDT)?

    Science.gov (United States)

    Nemes, Andrei; Fortmann, Thomas; Poeschke, Stephan; Greve, Burkhard; Prevedello, Daniel; Santacroce, Antonio; Stummer, Walter; Senner, Volker; Ewelt, Christian

    2016-01-01

    Pituitary adenomas (PA), especially invasive ones, are often not completely resectable. Usage of 5-aminolevulinic acid (5-ALA) for fluorescence guided surgery could improve the rate of total resection and, additionally, open the doors for photodynamic therapy (PDT) in case of unresectable or partially resected PAs. The aim of this study was to investigate the uptake of 5-ALA and the effect of 5-ALA based PDT in cell lines. GH3 and AtT-20 cell lines were incubated with different concentrations of 5-ALA, protoporphyrin IX (PPIX) fluorescence was measured by flow cytometry and fluorescencespectrometry. WST-1 assays were performed to determine the surviving fraction of cells after PDT. PPIX fluorescence intensities and PDT effect of the pituitary adenoma cells were compared to U373MG, a well-known glioblastoma cell line. Both cell lines showed a 5-ALA dependent intracellular PPIX fluorescence. Significant differences after 24hrs of incubation were observed in AtT-20 cells in comparison to GH3. Regardless of the incubation or metabolism time, there was a proliferation inhibiting effect after PDT, with no statistical significance. Since GH3 cells showed a heterogenous uptake of 5-ALA in the flow cytometry profile, but not constantly high concentrations they might have a 5-ALA efflux mechanism, which still needs to be determined. In the case of AtT-20, the cells might need a longer time for the uptake due to their size or slow metabolism. We showed that the different cell lines have different uptake and metabolism mechanisms, which needs to be further investigated. The general uptake of 5-ALA allows the possibility of resection control and PDT for pituitary adenomas. But, the role of PDT for unresectable pituitary adenomas deserves further investigations.

  18. Synaptotagmin-7 Functions to Replenish Insulin Granules for Exocytosis in Human Islet β-Cells.

    Science.gov (United States)

    Dolai, Subhankar; Xie, Li; Zhu, Dan; Liang, Tao; Qin, Tairan; Xie, Huanli; Kang, Youhou; Chapman, Edwin R; Gaisano, Herbert Y

    2016-07-01

    Synaptotagmin (Syt)-7, a major component of the exocytotic machinery in neurons, is also the major Syt in rodent pancreatic β-cells shown to mediate glucose-stimulated insulin secretion (GSIS). However, Syt-7's precise exocytotic actions in β-cells remain unknown. We show that Syt-7 is abundant in human β-cells. Adenovirus-short hairpin RNA knockdown (KD) of Syt-7 in human islets reduced first- and second-phase GSIS attributed to the reduction of exocytosis of predocked and newcomer insulin secretory granules (SGs). Glucose stimulation expectedly induced Syt-7 association in a Ca(2+)-dependent manner with syntaxin-3 and syntaxin-1A soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) complexes known to mediate exocytosis of newcomer and predocked SGs, respectively. However, Syt-7-KD did not disrupt SNARE complex assembly. Instead, electron microscopy analysis showed that Syt-7-KD reduced the recruitment of SGs to the plasma membrane after glucose-stimulated depletion, which could not be rescued by glucagon-like peptide 1 pretreatment. To assess the possibility that this new action of Syt-7 on SG recruitment may involve calmodulin (CaM), pretreatment of islets with CaM blocker calmidazolium showed effects very similar to those of Syt-7-KD. Syt-7 therefore plays a novel more dominant function in the replenishment of releasable SG pools in human β-cells than its previously purported role in exocytotic fusion per se. © 2016 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

  19. Carcinoma ex basal cell adenoma of the parotid gland: A report of an extremely rare case.

    Science.gov (United States)

    Kusafuka, Kimihide; Kawasaki, Takuya; Nakajima, Takashi; Sugino, Takashi

    2017-07-01

    Malignant non-basaloid tumors that arise from basal cell adenoma (BCA) are extremely rare. The patient was a 72-year-old Japanese male, who had noticed swelling of the left parotid region 21 years ago. A superficial lobectomy was performed. About 60% of the tumor was made up of cribriform and trabecular tissue composed of basaloid cells, which exhibited mild atypia and nuclear expression of β-catenin. This portion of the tumor was considered to be a BCA. In the other part of the tumor, the proliferation of large eosinophilic atypical cells, most of which formed intraductal structures, was observed. These tumor cells displayed cellular atypia, and some of them formed Roman bridge structures or contributed to intracapsular invasion. Immunohistochemically, these cells were positive for cytokeratin 7, gross cystic disease fluid proten-15 (GCDFP-15), androgen receptor (AR), and mammaglobin (MMG) and exhibited a high Ki-67 labeling index. So, this portion of the tumor was considered to be a salivary duct carcinoma (SDC). The tumor's final diagnosis was SDC ex BCA (intracapsular type), which is extremely rare. GCDFP-15, AR, MMG, and Ki-67 are useful immunohistochemical markers for diagnosing SDC ex BCA. © 2017 The Authors. Pathology International Published by Japanese Society of Pathology and John Wiley & Sons Australia, Ltd.

  20. 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.

  1. 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.

  2. PACAP inhibits β-cell mass expansion in a mouse model of type II diabetes: persistent suppressive effects on islet density

    Directory of Open Access Journals (Sweden)

    Hiroaki eInoue

    2013-03-01

    Full Text Available Pituitary adenylate cyclase-activating polypeptide (PACAP is a potent insulinotropic G-protein-coupled receptor ligand, for which morphoregulative roles in pancreatic islets have recently been suggested. Here, we evaluated the effects of pancreatic overexpression of PACAP on morphometric changes of islets in a severe type II diabetes model. Following cross-breeding of obese-diabetic model KKAy mice with mice overexpressing PACAP in their pancreatic β-cells, the resulting KKAy mice with or without PACAP transgene (PACAP/+:Ay/+ or Ay/+ mice were fed with a high-fat diet up to the age of 11 months. Pancreatic sections from 5 and 11 month old littermates were examined. Histomorphometric analyses revealed significant suppression of islet mass expansion in PACAP/+:Ay/+ mice compared with Ay/+ mice at 11 months, but no significant difference between PACAP/+ and +/+ (wild-type mice, as previously reported. The suppressed islet mass in PACAP/+:Ay/+ mice was due to a decrease in islet density but not islet size. In addition, the density of tiny islets (<0.001 mm2 and of insulin-positive clusters in ductal structures were markedly decreased in PACAP/+:Ay/+ mice compared with Ay/+ mice at 5 months of age. In contrast, PACAP overexpression caused no significant effects on the level of aldehyde-fuchsin reagent staining (a measure of β-cell granulation or the volume and localization of glucagon-positive cells in the pancreas. These results support previously reported inhibitory effects of PACAP on pancreatic islet mass expansion, and suggest it has persistent suppressive effects on pancreatic islet density which may be related with ductal cell-associated islet neogenesis in type II diabetes.

  3. Adenomas hipofisários: relação entre invasividade e índice proliferativo tumoral Pituitary adenomas: relationship between invasiveness and proliferative cell nuclear index

    Directory of Open Access Journals (Sweden)

    OSWALDO INÁCIO DE TELLA JR

    2000-12-01

    Full Text Available Analisamos 76 pacientes com adenomas hipofisários do ponto de vista clínico, radiológico e tratamento cirúrgico. Todos os casos foram estudados por imuno-histoquímica e em 49 pacientes foi pesquisado o anticorpo monoclonal PCNA. Os adenomas bi-hormonais foram os mais frequentes seguidos dos prolactinomas e os adenomas não secretantes. Os adenomas bi-hormonais não secretantes e os produtores de subunidade alfa foram proporcionalmente mais invasivos pelos critérios radiológicos. A maioria dos pacientes (59 foi operada por via transeptoesfenoidal, em seis casos a via transcraniana foi realizada e em 11 pacientes houve necessidade das duas abordagens. A ressecção foi total em 32 pacientes, a maioria em microadenomas, subtotal em 15 e parcial em 29. A complicação endócrina mais frequente foi diabetes insipidus. Houve tendência de associação positiva para os adenomas secretantes e PCNA mais elevado, assim como relação positiva quando analisamos os adenomas invasivos pela tomografia computadorizada ou ressonância magnética e o PCNA 3 e 4. A melhora visual foi observada em 85% dos macroadenomas, mesmo quando a ressecção foi parcial ou subtotal.We evaluated clinically, radiologically and surgically a series of 76 pituitary adenomas. All cases were assessed immunohistochemically and in 49 patients the PCNA monoclonal antibody was measured. The most frequent types found were the bihormonal adenomas, followed by prolactinomas and non secreting adenomas. The bihormonal adenomas, non secreting adenonas and the sub unit alfa producing adenomas were proportionally more invase as determined by radiological criteria (CTscan or MRI. In 59 patients a transphenoidal approach was used, six cases were operated on transcranially and in 11 patients we used a combination of both approach. Total resection were achieved in 32 cases, most of which were microadenomas, in 15 cases the resection was subtotal and partial in 29 cases. Diabetes insipidus

  4. Allogeneic islet transplantation.

    Science.gov (United States)

    Marzorati, Simona; Pileggi, Antonello; Ricordi, Camillo

    2007-11-01

    Significant progress has been made in the field of beta-cell replacement therapies by islet transplantation in patients with unstable Type 1 diabetes mellitus (T1DM). Recent clinical trials have shown that islet transplantation can reproducibly lead to insulin independence when adequate islet numbers are implanted. Benefits include improvement of glycemic control, prevention of severe hypoglycemia and amelioration of quality of life. Numerous challenges still limit this therapeutic option from becoming the treatment of choice for T1DM. The limitations are primarily associated with the low islet yield of human pancreas isolations and the need for chronic immunosuppressive therapies. Herein the authors present an overview of the historical progress of islet transplantation and outline the recent advances of the field. Cellular therapies offer the potential for a cure for patients with T1DM. The progress in beta-cell replacement treatment by islet transplantation as well as those of emerging immune interventions for the restoration of self tolerance justify great optimism for years to come.

  5. 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

  6. Novel Observations From Next-Generation RNA Sequencing of Highly Purified Human Adult and Fetal Islet Cell Subsets.

    Science.gov (United States)

    Blodgett, David M; Nowosielska, Anetta; Afik, Shaked; Pechhold, Susanne; Cura, Anthony J; Kennedy, Norman J; Kim, Soyoung; Kucukural, Alper; Davis, Roger J; Kent, Sally C; Greiner, Dale L; Garber, Manuel G; Harlan, David M; diIorio, Philip

    2015-09-01

    Understanding distinct gene expression patterns of normal adult and developing fetal human pancreatic α- and β-cells is crucial for developing stem cell therapies, islet regeneration strategies, and therapies designed to increase β-cell function in patients with diabetes (type 1 or 2). Toward that end, we have developed methods to highly purify α-, β-, and δ-cells from human fetal and adult pancreata by intracellular staining for the cell-specific hormone content, sorting the subpopulations by flow cytometry, and, using next-generation RNA sequencing, we report the detailed transcriptomes of fetal and adult α- and β-cells. We observed that human islet composition was not influenced by age, sex, or BMI, and transcripts for inflammatory gene products were noted in fetal β-cells. In addition, within highly purified adult glucagon-expressing α-cells, we observed surprisingly high insulin mRNA expression, but not insulin protein expression. This transcriptome analysis from highly purified islet α- and β-cell subsets from fetal and adult pancreata offers clear implications for strategies that seek to increase insulin expression in type 1 and type 2 diabetes. © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

  7. Prevalence and predictive value of islet cell antibodies and insulin autoantibodies in women with gestational diabetes

    DEFF Research Database (Denmark)

    Damm, P; Kühl, C; Buschard, K

    1994-01-01

    The objective of the present study was to investigate the predictive value of islet cell antibodies (ICA) and insulin autoantibodies (IAA) for development of diabetes in women with previous gestational diabetes (GDM). Two hundred and forty-one previous diet-treated GDM patients and 57 women without...... previous GDM were examined 2-11 years after the index pregnancy. In subgroups, plasma from the diagnostic OGTT during index pregnancy was analysed for ICA and IAA. Among the previous GDM patients, 3.7% had developed Type 1 diabetes and 13.7% Type 2 diabetes. Four (2.9%) of the 139 GDM patients tested...... for ICA were ICA-positive and three of these had Type 1 diabetes at follow-up, as well as three ICA-negative patients. The sensitivity, specificity, and predictive value of ICA-positivity for later development of diabetes were 50%, 99%, and 75%, respectively. None of the women was IAA-positive during...

  8. Cooperation by Fibroblasts and Bone Marrow-Mesenchymal Stem Cells to Improve Pancreatic Rat-to-Mouse Islet Xenotransplantation

    Science.gov (United States)

    Meana, Alvaro; Otero, Jesus; Esteban, Manuel M.

    2013-01-01

    Experimental and clinical experiences highlight the need to review some aspects of islet transplantation, especially with regard to site of grafting and control of the immune response. The subcutaneous space could be a good alternative to liver but its sparse vasculature is its main limitation. Induction of graft tolerance by using cells with immunoregulatory properties is a promising approach to avoid graft rejection. Both Fibroblasts and Mesenchymal Stem Cells (MSCs) have shown pro-angiogenic and immunomodulatory properties. Transplantation of islets into the subcutaneous space using plasma as scaffold and supplemented with fibroblasts and/or Bone Marrow-MSCs could be a promising strategy to achieve a functional extra-hepatic islet graft, without using immunosuppressive drugs. Xenogenic rat islets, autologous fibroblasts and/or allogenic BM-MSCs, were mixed with plasma, and coagulation was induced to constitute a Plasma-based Scaffold containing Islets (PSI), which was transplanted subcutaneously both in immunodeficient and immunocompetent diabetic mice. In immunodeficient diabetic mice, PSI itself allowed hyperglycemia reversion temporarily, but the presence of pro-angiogenic cells (fibroblasts or BM-MSCs) within PSI was necessary to improve graft re-vascularization and, thus, consistently maintain normoglycemia. In immunocompetent diabetic mice, only PSI containing BM-MSCs, but not those containing fibroblasts, normalized glycemia lasting up to one week after transplantation. Interestingly, when PSI contained both fibroblasts and BM-MSCs, the normoglycemia period showed an increase of 4-times with a physiological-like response in functional tests. Histology of immunocompetent mice showed an attenuation of the immune response in those grafts with BM-MSCs, which was improved by co-transplantation with fibroblasts, since they increased BM-MSC survival. In summary, fibroblasts and BM-MSCs showed similar pro-angiogenic properties in this model of islet

  9. Distinct differences in the responses of the human pancreatic β-cell line EndoC-βH1 and human islets to proinflammatory cytokines

    Science.gov (United States)

    Oleson, Bryndon J.; McGraw, Jennifer A.; Broniowska, Katarzyna A.; Annamalai, Mani; Chen, Jing; Bushkofsky, Justin R.; Davis, Dawn B.; Mathews, Clayton E.

    2015-01-01

    While insulinoma cells have been developed and proven to be extremely useful in studies focused on mechanisms controlling β-cell function and viability, translating findings to human β-cells has proven difficult because of the limited access to human islets and the absence of suitable insulinoma cell lines of human origin. Recently, a human β-cell line, EndoC-βH1, has been derived from human fetal pancreatic buds. The purpose of this study was to determine whether human EndoC-βH1 cells respond to cytokines in a fashion comparable to human islets. Unlike most rodent-derived insulinoma cell lines that respond to cytokines in a manner consistent with rodent islets, EndoC-βH1 cells fail to respond to a combination of cytokines (IL-1, IFN-γ, and TNF) in a manner consistent with human islets. Nitric oxide, produced following inducible nitric oxide synthase (iNOS) expression, is a major mediator of cytokine-induced human islet cell damage. We show that EndoC-βH1 cells fail to express iNOS or produce nitric oxide in response to this combination of cytokines. Inhibitors of iNOS prevent cytokine-induced loss of human islet cell viability; however, they do not prevent cytokine-induced EndoC-βH1 cell death. Stressed human islets or human islets expressing heat shock protein 70 (HSP70) are resistant to cytokines, and, much like stressed human islets, EndoC-βH1 cells express HSP70 under basal conditions. Elevated basal expression of HSP70 in EndoC-βH1 cells is consistent with the lack of iNOS expression in response to cytokine treatment. While expressing HSP70, EndoC-βH1 cells fail to respond to endoplasmic reticulum stress activators, such as thapsigargin. These findings indicate that EndoC-βH1 cells do not faithfully recapitulate the response of human islets to cytokines. Therefore, caution should be exercised when making conclusions regarding the actions of cytokines on human islets when using this human-derived insulinoma cell line. PMID:26084699

  10. ADENOMA HIPOFISIS

    Directory of Open Access Journals (Sweden)

    Muhammad Hidayat

    2015-09-01

    Full Text Available AbstrakAdenoma hipofisis diklasifikasikan berdasarkan beberapa kriteria yaitu klinis dan endokrin, patologi, serta radiologi. Klasifikasi endokrin membedakan tumor sebagai fungsional dan nonfungsional, berdasarkan aktivitas sekretorinya in-vivo. Klasifikasi patologi berusaha untuk membatasi kelompok tumor heterogenus secara klinis dan patologis dengan kategori yaitu asidofilik, basofilik, dan kromofobik. Klasifikasi radiologi mengelompokkan tumor hipofisis berdasarkan ukuran dan karakteristik pertumbuhan, yang dapat ditemukan dari studi imaging. WHO membuat klasifikasi yang mencoba untuk mengintegrasikan semua klasifikasi yang ada dan menyediakan sinopsis praktis untuk aspek klinis dan patologis dari adenoma. Diagnosa adenoma hipofisis dibuat berdasarkan: gejala klinis dari gangguan hormon, adanya riwayat penyakit dahulu yang jelas, pemeriksaan fisik yang menunjang, pemeriksaan laboratorium yang menunjukkan disfungsi dari hormon yang terganggu, adanya pemeriksaan penunjang yang akurat seperti CTScan, MRI-Scan. Jenis, besar dan fungsi dari tumor sangat menentukan dalam mempertimbangkan penatalaksanaan dari adenoma hipofisis. Pengobatan diindikasikan pada semua pasien dengan gejala, terutama dengan hipogonadisme. Pilihan terapi termasuk kontrol dengan obat-obatan, reseksi bedah, dan terapi radiasi.AbstractPituitary adenomas are classified according to several criteria; clinical endocrine, pathology, and radiology. Endocrine classification distinguishes tumors as functional and nonfunctional, based on in-vivo secretory activity. Pathology classification seeks to restrict clinically heterogeneous group of tumors and pathological categories namely acidophilic, basophilic, and kromofobik. Radiological classification classifies pituitary tumors by size and growth characteristics, which can be found on imaging studies. WHO made a classification that attempts to integrate all existing classifications and provide practical synopsis for the clinical and

  11. Calcium or resistant starch does not affect colonic epithelial cell proliferation throughout the colon in adenoma patients : A randomized controlled trial

    NARCIS (Netherlands)

    van Gorkom, Britta A P; Karrenbeld, Arend; van der Sluis, Tineke; Zwart, Nynke; van der Meer, Roelof; de Vries, Elisabeth G E; Kleibeuker, Jan H

    2002-01-01

    Patients with a history of sporadic adenomas have increased epithelial cell proliferative activity, an intermediate risk marker for colorectal cancer. Reduction of proliferation by dietary intervention may reflect a decreased colorectal cancer risk. To evaluate whether calcium or resistant starch

  12. Radical-scavenging effects of Aloe arborescens Miller on prevention of pancreatic islet B-cell destruction in rats.

    Science.gov (United States)

    Beppu, Hidehiko; Koike, Takaaki; Shimpo, Kan; Chihara, Takeshi; Hoshino, Motoyuki; Ida, Chikako; Kuzuya, Hiroshi

    2003-11-01

    We evaluated the possible scavenging effects of Aloe arborescens Miller var. natalensis Berger (Kidachi aloe in Japanese) on free radicals generated by streptozotocin (Sz) or alloxan (Ax). The components of Kidachi aloe were added to a reaction system in which .OH radicals derived from Sz or Ax as pancreatic islet B-cell toxins and hypoxanthine-xanthine oxidase (HX-XO)-derived O(2) radicals destroy isolated islet B-cells, and we observed its preventive effects. The Kidachi aloe components inhibited the destruction of rat pancreatic islet B-cells by Sz, Ax or HX-XO. These components were prepared in the form of a freeze-dried powder of the boiled leaf skin of Kidachi aloe, and measurement of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity showed higher radical-scavenging activity in this boiled leaf skin powder than the non-boiled leaf skin powder.Furthermore, HPLC chromatograms of the "Boiled leaf skin powder" were similar to those of commercially available aloin (barbaloin content: approximately 20%). Therefore, the main component may be a phenol compound. In addition, the phenolic fraction of the Boiled leaf skin contained large amounts of 2'-O-p-coumaroylaloesin and 2'-O-feruloylaloesin, which have higher DPPH radical-scavenging activity than barbaloin. These results suggest that the action mechanism of Kidachi aloe Boiled leaf skin components, which prevent destruction of the pancreatic islets by specific pancreatic islet toxins such as Sz, Ax, and HX-XO, involves inhibition of free radical-scavenging effects, and may be associated with a thermostable low molecular component. The co-existence of Kidachi aloe-derived 2'-O-p-coumaroylaloesin, 2'-O-feruloylaloesin, and aloin may result in the potentiation of radical-scavenging activity.

  13. A VGF-derived peptide attenuates development of type 2 diabetes via enhancement of islet β-cell survival and function.

    Science.gov (United States)

    Stephens, Samuel B; Schisler, Jonathan C; Hohmeier, Hans E; An, Jie; Sun, Albert Y; Pitt, Geoffrey S; Newgard, Christopher B

    2012-07-03

    Deterioration of functional islet β-cell mass is the final step in progression to Type 2 diabetes. We previously reported that overexpression of Nkx6.1 in rat islets has the dual effects of enhancing glucose-stimulated insulin secretion (GSIS) and increasing β-cell replication. Here we show that Nkx6.1 strongly upregulates the prohormone VGF in rat islets and that VGF is both necessary and sufficient for Nkx6.1-mediated enhancement of GSIS. Moreover, the VGF-derived peptide TLQP-21 potentiates GSIS in rat and human islets and improves glucose tolerance in vivo. Chronic injection of TLQP-21 in prediabetic ZDF rats preserves islet mass and slows diabetes onset. TLQP-21 prevents islet cell apoptosis by a pathway similar to that used by GLP-1, but independent of the GLP-1, GIP, or VIP receptors. Unlike GLP-1, TLQP-21 does not inhibit gastric emptying or increase heart rate. We conclude that TLQP-21 is a targeted agent for enhancing islet β-cell survival and function. Copyright © 2012 Elsevier Inc. All rights reserved.

  14. 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

    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...... 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...

  15. Residue specific effects of human islet polypeptide amyloid on self-assembly and on cell toxicity

    NARCIS (Netherlands)

    Khemtemourian, L.P.; Guillemain, Ghislaine; Foufelle, Fabienne; Killian, J Antoinette

    2017-01-01

    Type 2 diabetes mellitus is characterized histopathologically by the presence of fibrillary amyloid deposits in the pancreatic islets of Langerhans. Human islet amyloid polypeptide (hIAPP), the 37-residue pancreatic hormone, is the major constituent of these amyloid deposits. The propensity of IAPP

  16. Beta-cell function in isolated human pancreatic islets in long-term tissue culture

    DEFF Research Database (Denmark)

    Nielsen, Jens Høiriis

    1981-01-01

    Human pancreatic islets were isolated by collagenase treatment of pancreatic tissue obtained from 27 individuals aged 12 to 69 years. The islets were maintained free floating in tissue culture medium RPMI 1640 supplemented with calf or human serum. In two cases the insulin production was followed...

  17. Alginate encapsulation of human embryonic stem cells to enhance directed differentiation to pancreatic islet-like cells.

    Science.gov (United States)

    Richardson, Thomas; Kumta, Prashant N; Banerjee, Ipsita

    2014-12-01

    The pluripotent property of human embryonic stem cells (hESCs) makes them attractive for treatment of degenerative diseases such as diabetes. We have developed a stage-wise directed differentiation protocol to produce alginate-encapsulated islet-like cells derived from hESCs, which can be directly implanted for diabetes therapy. The advantage of alginate encapsulation lies in its capability to immunoisolate, along with the added possibility of scalable culture. We have evaluated the possibility of encapsulating hESCs at different stages of differentiation. Encapsulation of predifferentiated cells resulted in insufficient cellular yield and differentiation. On the other hand, encapsulation of undifferentiated hESCs followed by differentiation induction upon encapsulation resulted in the highest viability and differentiation. More striking was that alginate encapsulation resulted in a much stronger differentiation compared to parallel two-dimensional cultures, resulting in 20-fold increase in c-peptide protein synthesis. To elucidate the mechanism contributing to encapsulation-mediated enhancement in hESC maturation, investigation of the signaling pathways revealed interesting insight. While the phospho-protein levels of all the tested signaling molecules were lower under encapsulation, the ratio of pSMAD/pAKT was significantly higher, indicating a more efficient signal transduction under encapsulation. These results clearly demonstrate that alginate encapsulation of hESCs and differentiation to islet-cell types provides a potentially translatable treatment option for type 1 diabetes.

  18. A VGF-derived peptide attenuates development of type 2 diabetes via enhancement of islet β-cell survival and function

    OpenAIRE

    Stephens, Samuel B.; Schisler, Jonathan C.; Hohmeier, Hans E.; An, Jie; Sun, Albert Y.; Pitt, Geoffrey S.; Newgard, Christopher B.

    2012-01-01

    Deterioration of functional islet β-cell mass is the final step in progression to Type 2 diabetes. We previously reported that overexpression of Nkx6.1 in rat islets has the dual effects of enhancing glucose-stimulated insulin secretion (GSIS) and increasing β-cell replication. Here we show that Nkx6.1 strongly upregulates the prohormone VGF in rat islets and that VGF is both necessary and sufficient for Nkx6.1-mediated enhancement of GSIS. Moreover, the VGF-derived peptide TLQP-21 potentiate...

  19. Type 2 diabetes susceptibility gene expression in normal or diabetic sorted human alpha and beta cells: correlations with age or BMI of islet donors.

    Directory of Open Access Journals (Sweden)

    Clare L Kirkpatrick

    Full Text Available BACKGROUND: Genome-wide association studies have identified susceptibility genes for development of type 2 diabetes. We aimed to examine whether a subset of these (comprising FTO, IDE, KCNJ11, PPARG and TCF7L2 were transcriptionally restricted to or enriched in human beta cells by sorting islet cells into alpha and beta - specific fractions. We also aimed to correlate expression of these transcripts in both alpha and beta cell types with phenotypic traits of the islet donors and to compare diabetic and non-diabetic cells. METHODOLOGY/PRINCIPAL FINDINGS: Islet cells were sorted using a previously published method and RNA was extracted, reverse transcribed and used as the template for quantitative PCR. Sorted cells were also analysed for insulin and glucagon immunostaining and insulin secretion from the beta cells as well as insulin, glucagon and GLP-1 content. All five genes were expressed in both alpha and beta cells, with significant enrichment of KCNJ11 in the beta cells and of TCF7L2 in the alpha cells. The ratio of KCNJ11 in beta to alpha cells was negatively correlated with BMI, while KCNJ11 expression in alpha cells was negatively correlated with age but not associated with BMI. Beta cell expression of glucagon, TCF7L2 and IDE was increased in cells from islets that had spent more time in culture prior to cell sorting. In beta cells, KCNJ11, FTO and insulin were positively correlated with each other. Diabetic alpha and beta cells had decreased expression of insulin, glucagon and FTO. CONCLUSIONS/SIGNIFICANCE: This study has identified novel patterns of expression of type 2 diabetes susceptibility genes within sorted islet cells and suggested interactions of gene expression with age or BMI of the islet donors. However, expression of these genes in islets is less associated with BMI than has been found for other tissues.

  20. Pancreatic islet transplantation

    Directory of Open Access Journals (Sweden)

    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

  1. Testosterone reduces AGTR1 expression to prevent β-cell and islet apoptosis from glucotoxicity.

    Science.gov (United States)

    Kooptiwut, Suwattanee; Hanchang, Wanthanee; Semprasert, Namoiy; Junking, Mutita; Limjindaporn, Thawornchai; Yenchitsomanus, Pa-thai

    2015-03-01

    Hypogonadism in men is associated with an increased incidence of type 2 diabetes. Supplementation with testosterone has been shown to protect pancreatic β-cell against apoptosis due to toxic substances including streptozotocin and high glucose. One of the pathological mechanisms of glucose-induced pancreatic β-cell apoptosis is the induction of the local rennin-angiotensin-aldosterone system (RAAS). The role of testosterone in regulation of the pancreatic RAAS is still unknown. This study aims to investigate the protective action of testosterone against glucotoxicity-induced pancreatic β-cell apoptosis via alteration of the pancreatic RAAS pathway. Rat insulinoma cell line (INS-1) cells or isolated male mouse islets were cultured in basal and high-glucose media in the presence or absence of testosterone, losartan, and angiotensin II (Ang II), then cell apoptosis, cleaved caspase 3 expression, oxidative stress, and expression of angiotensin II type 1 receptor (AGTR1) and p47(phox) mRNA and protein were measured. Testosterone and losartan showed similar effects in reducing pancreatic β-cell apoptosis. Testosterone significantly reduced expression of AGTR1 protein in INS-1 cells cultured in high-glucose medium or high-glucose medium with Ang II. Testosterone decreased the expression of AGTR1 and p47(phox) mRNA and protein in comparison with levels in cells cultured in high-glucose medium alone. Furthermore, testosterone attenuated superoxide production when co-cultured with high-glucose medium. In contrast, when cultured in basal glucose, supplementation of testosterone did not have any effect on cell apoptosis, oxidative stress, and expression of AGT1R and p47(phox). In addition, high-glucose medium did not increase cleaved caspase 3 in AGTR1 knockdown experiments. Thus, our results indicated that testosterone prevents pancreatic β-cell apoptosis due to glucotoxicity through reduction of the expression of ATGR1 and its signaling pathway. © 2015 Society for

  2. Loss of β-Cell Identity Occurs in Type 2 Diabetes and Is Associated With Islet Amyloid Deposits.

    Science.gov (United States)

    Spijker, H Siebe; Song, Heein; Ellenbroek, Johanne H; Roefs, Maaike M; Engelse, Marten A; Bos, Erik; Koster, Abraham J; Rabelink, Ton J; Hansen, Barbara C; Clark, Anne; Carlotti, Françoise; de Koning, Eelco J P

    2015-08-01

    Loss of pancreatic islet β-cell mass and β-cell dysfunction are central in the development of type 2 diabetes (T2DM). We recently showed that mature human insulin-containing β-cells can convert into glucagon-containing α-cells ex vivo. This loss of β-cell identity was characterized by the presence of β-cell transcription factors (Nkx6.1, Pdx1) in glucagon(+) cells. Here, we investigated whether the loss of β-cell identity also occurs in vivo, and whether it is related to the presence of (pre)diabetes in humans and nonhuman primates. We observed an eight times increased frequency of insulin(+) cells coexpressing glucagon in donors with diabetes. Up to 5% of the cells that were Nkx6.1(+) but insulin(-) coexpressed glucagon, which represents a five times increased frequency compared with the control group. This increase in bihormonal and Nkx6.1(+)glucagon(+)insulin(-) cells was also found in islets of diabetic macaques. The higher proportion of bihormonal cells and Nkx6.1(+)glucagon(+)insulin(-) cells in macaques and humans with diabetes was correlated with the presence and extent of islet amyloidosis. These data indicate that the loss of β-cell identity occurs in T2DM and could contribute to the decrease of functional β-cell mass. Maintenance of β-cell identity is a potential novel strategy to preserve β-cell function in diabetes. © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

  3. Trimodal Gadolinium-Gold Microcapsules Containing Pancreatic Islet Cells Restore Normoglycemia in Diabetic Mice and Can Be Tracked by Using US, CT, and Positive-Contrast MR Imaging

    Science.gov (United States)

    Arifin, Dian R.; Long, Christopher M.; Gilad, Assaf A.; Alric, Christophe; Roux, Stéphane; Tillement, Olivier; Link, Thomas W.; Arepally, Aravind; Bulte, Jeff W. M.

    2011-01-01

    Purpose: To develop microcapsules that immunoprotect pancreatic islet cells for treatment of type I diabetes and enable multimodal cellular imaging of transplanted islet cells. Materials and Methods: All animal experiments were approved by the institutional animal care and use committee. Gold nanoparticles functionalized with DTDTPA (dithiolated diethylenetriaminepentaacetic acid):gadolinium chelates (GG) were coencapsulated with pancreatic islet cells by using protamine sulfate as a clinical-grade alginate cross linker. Conventional poly-l-lysine–cross-linked microcapsules and unencapsulated islets were included as controls. The viability and glucose responsiveness of islet cells were assessed in vitro, and in vivo insulin (C-peptide) secretion was monitored for 6 weeks in (streptozotocin-induced) diabetic mice with (n = 7) or without (n = 8) intraabdominally engrafted islet cells. Five nondiabetic mice were included as controls. Differences between samples were calculated by using a nonparametric Wilcoxon Mann-Whitney method. To adjust for multiple comparisons, a significance level of P microcapsules could be readily visualized with positive-contrast high-field-strength MR imaging, micro-CT, and US both in vitro and in vivo. Conclusion: Cell encapsulation with GG provides a means of trimodal noninvasive tracking of engrafted cells. © RSNA, 2011 Supplemental material: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.11101608/-/DC1 PMID:21734156

  4. Progressive glucose stimulation of islet beta cells reveals a transition from segregated to integrated modular functional connectivity patterns.

    Science.gov (United States)

    Markovič, Rene; Stožer, Andraž; Gosak, Marko; Dolenšek, Jurij; Marhl, Marko; Rupnik, Marjan Slak

    2015-01-19

    Collective beta cell activity in islets of Langerhans is critical for the supply of insulin within an organism. Even though individual beta cells are intrinsically heterogeneous, the presence of intercellular coupling mechanisms ensures coordinated activity and a well-regulated exocytosis of insulin. In order to get a detailed insight into the functional organization of the syncytium, we applied advanced analytical tools from the realm of complex network theory to uncover the functional connectivity pattern among cells composing the intact islet. The procedure is based on the determination of correlations between long temporal traces obtained from confocal functional multicellular calcium imaging of beta cells stimulated in a stepwise manner with a range of physiological glucose concentrations. Our results revealed that the extracted connectivity networks are sparse for low glucose concentrations, whereas for higher stimulatory levels they become more densely connected. Most importantly, for all ranges of glucose concentration beta cells within the islets form locally clustered functional sub-compartments, thereby indicating that their collective activity profiles exhibit a modular nature. Moreover, we show that the observed non-linear functional relationship between different network metrics and glucose concentration represents a well-balanced setup that parallels physiological insulin release.

  5. In Vivo Costimulation Blockade-Induced Regulatory T Cells Demonstrate Dominant and Specific Tolerance to Porcine Islet Xenografts.

    Science.gov (United States)

    Wu, Jingjing; Hu, Min; Qian, Yi Wen; Hawthorne, Wayne J; Burns, Heather; Liuwantara, David; Alexander, Stephen I; Yi, Shounan; O'Connell, Philip J

    2017-07-01

    Although islet xenotransplantation is a promising therapy for type 1 diabetes, its clinical application has been hampered by cellular rejection and the requirement for high levels of immunosuppression. The aim of this study was to determine the role of Foxp3 regulatory T (Treg) cells in costimulation blockade-induced dominant tolerance to porcine neonatal islet cell cluster (NICC) xenografts in mice. Porcine-NICC were transplanted under the renal capsule of BALB/c or C57BL/6 recipients and given a single dose of CTLA4-Fc at the time of transplant and 4doses of anti-CD154 mAb to day 6. Depletion of Foxp3Treg cell was performed in DEpletion of REGulatory T cells mice at day 80 posttransplantation. Foxp3Treg cell from spleens of treated BALB/c mice (tolerant Treg cell), and splenocytes were cotransferred into islet transplanted nonobese diabetic background with severe combined immunodeficiency mice to assess suppressive function. In treated mice, increased numbers of Foxp3Treg cell were identified in the porcine-NICC xenografts, draining lymph node, and spleen. Porcine-NICC xenografts from treated mice expressed elevated levels of TGF-β, IL-10 and IFN-γ. Porcine-NICC xenograft tolerance was abrogated after depletion of Foxp3Treg cell. Tolerant Treg cell produced high levels of IL-10 and had diverse T cell receptor Vβ repertoires with an oligoclonal expansion in CDR3 of T cell receptor Vβ14. These tolerant Treg cells had the capacity to transfer dominant tolerance and specifically exhibited more potent regulatory function to porcine-NICC xenografts that naive Treg cell. This study demonstrated that short-term costimulation blockade-induced dominant tolerance and that Foxp3Treg cell played an essential role in its maintenance. Foxp3Treg cells were activated and had more potent regulatory function in vivo than naive Treg cells.

  6. 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

  7. The effect of ghrelin on Kiss-1 and KissR gene transcription and insulin secretion in rat islets of Langerhans and CRI-D2 cell line

    Directory of Open Access Journals (Sweden)

    Mandana Mahmoodzaeh Sagheb

    2017-01-01

    Full Text Available Objective(s: Ghrelin is a peptide hormone that has been shown to have numerous central and peripheral effects. The central effects including GH secretion, food intake, and energy homeostasis are partly mediated by Kiss1- KissR signaling pathway. Ghrelin and its receptor are also expressed in the pancreatic islets. Ghrelin is one of the key metabolic factors controlling insulin secretion from the islets of Langerhans. We hypothesize that the inhibitory effect of ghrelin on KiSS-1 and KissR in the islet cells may be similar to the same inhibitory effect of ghrelin in the hypothalamus. Materials and Methods: To investigate the effect of ghrelin, we isolated the islets from adult male rats by collagenase and cultured CRI-D2 cell lines. Then, we incubated them with different concentrations of ghrelin for 24 hr. After RNA extraction and cDNA synthesis from both islets and CRI-D2 cells, the relative expression of KiSS-1 and KissR was evaluated by means of real-time PCR. Furthermore, we measured the amount of insulin secreted by the islets after incubation in different concentrations of ghrelin and glucose after 1 hr. Besides, we checked the viability of the cells after 24 hr cultivation.  Results: Ghrelin significantly decreased the KiSS-1 and KissR mRNA transcription in rat islets and CRI-D2 cells. Besides, Ghrelin suppressed insulin secretion from pancreatic beta cells and CRI-D2 cells. Conclusion: These findings indicate the possibility that KiSS-1 and KissR mRNA expression is mediator of ghrelin function in the islets of Langerhans.

  8. Apoptosis in pancreatic β-islet cells in Type 2 diabetes

    Directory of Open Access Journals (Sweden)

    Tatsuo Tomita

    2016-08-01

    Full Text Available Apoptosis plays important roles in the pathophysiology of Type 2 diabetes mellitus (T2DM. The etiology of T2DM is multifactorial, including obesity-associated insulin resistance, defective insulin secretion, and loss of β-cell mass through β-cell apoptosis. β-cell apoptosis is mediated through a milliard of caspase family cascade machinery in T2DM. The glucose-induced insulin secretion is the principle pathophysiology of diabetes and insufficient insulin secretion results in chronic hyperglycemia, diabetes. Recently, hyperglycemia-induced β-cell apoptosis has been extensively studied on the balance of pro-apoptotic Bcl-2 proteins (Bad, Bid, Bik, and Bax and anti-apoptotic Bcl family (Bcl-2 and Bcl-xL toward apoptosis in vitro isolated islets and insulinoma cell culture. Apoptosis can only occur when the concentration of pro-apoptotic Bcl-2 exceeds that of anti-apoptotic proteins at the mitochondrial membrane of the intrinsic pathway. A bulk of recent research on hyperglycemia-induced apoptosis on β-cells unveiled complex details on glucose toxicity on β-cells in molecular levels coupled with cell membrane potential by adenosine triphosphate generation through K+ channel closure, opening Ca2+ channel and plasma membrane depolarization. Furthermore, animal models using knockout mice will shed light on the basic understanding of the pathophysiology of diabetes as a glucose metabolic disease complex, on the balance of anti-apoptotic Bcl family and pro-apoptotic genes. The cumulative knowledge will provide a better understanding of glucose metabolism at a molecular level and will lead to eventual prevention and therapeutic application for T2DM with improving medications.

  9. 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.

  10. Microcapsules with Intrinsic Barium Radiopacity for Immunoprotection and X-ray/CT imaging of Pancreatic Islet Cells

    Science.gov (United States)

    Arifin, D.R.; Manek, S.; Call, E.; Arepally, A.; Bulte, J.W.M.

    2012-01-01

    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. PMID:22444642

  11. 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.

  12. Effects of low intensity laser acupoint irradiation on inhibiting islet beta-cell apoptosis in rats with type 2 diabetes

    Science.gov (United States)

    Xiong, Guoxin; Xiong, Leilei; Li, Xinzhong

    2016-09-01

    To investigate the effects of low intensity semiconductor laser acupoint irradiation on inhibiting islet beta-cell apoptosis in rats with type 2 diabetes, a method using a high-fat diet and low-dose intraperitoneal injections of streptozotocin established a type 2 diabetes mellitus rat model. Model rats were randomly divided into a laser acupoint irradiation group, rosiglitazone control group, and placebo group; each group had 10 rats. In addition, 10 normal male rats were selected for the normal control group. The Housanli, Neiting and Yishu acupoints of the rats in the laser acupoint irradiation group were irradiated with a 10 mW semiconductor laser; each point was irradiated for 15 min, once every 2 d over 28 d, for a total of 14 episodes of irradiation. The rosiglitazone group rats were given rosiglitazone (0.2 mg kg-1) intragastrically; the placebo group rats were given 0.9% brine (0.2 mg kg-1) intragastrically, once daily, for four consecutive weeks. The change of fasting blood glucose was determined before and after each treatment. The islet beta-cell apoptosis was determined. The islet beta-cell apoptosis rates of the laser acupoint irradiation group and the rosiglitazone group were significantly lower than the rate of the placebo group. Even though the rate was lower in the laser acupoint irradiation group than in the rosiglitazone group, there was no significant difference between them. It is shown that acupoint irradiation with a semiconductor laser can effectively inhibit islet beta-cell apoptosis in rats with type 2 diabetes.

  13. Overexpression of PPARγ specifically in pancreatic β-cells exacerbates obesity-induced glucose intolerance, reduces β-cell mass, and alters islet lipid metabolism in male mice.

    Science.gov (United States)

    Hogh, K-Lynn N; Craig, Michael N; Uy, Christopher E; Nygren, Heli; Asadi, Ali; Speck, Madeline; Fraser, Jordie D; Rudecki, Alexander P; Baker, Robert K; Orešič, Matej; Gray, Sarah L

    2014-10-01

    The contribution of peroxisomal proliferator-activated receptor (PPAR)-γ agonism in pancreatic β-cells to the antidiabetic actions of thiazolidinediones has not been clearly elucidated. Genetic models of pancreatic β-cell PPARγ ablation have revealed a potential role for PPARγ in β-cell expansion in obesity but a limited role in normal β-cell physiology. Here we overexpressed PPARγ1 or PPARγ2 specifically in pancreatic β-cells of mice subjected to high-fat feeding using an associated adenovirus (β-PPARγ1-HFD and β-PPARγ2-HFD mice). We show β-cell-specific PPARγ1 or PPARγ2 overexpression in diet-induced obese mice exacerbated obesity-induced glucose intolerance with decreased β-cell mass, increased islet cell apoptosis, and decreased plasma insulin compared with obese control mice (β-eGFP-HFD mice). Analysis of islet lipid composition in β-PPARγ2-HFD mice revealed no significant changes in islet triglyceride content and an increase in only one of eight ceramide species measured. Interestingly β-PPARγ2-HFD islets had significantly lower levels of lysophosphatidylcholines, lipid species shown to enhance insulin secretion in β-cells. Gene expression profiling revealed increased expression of uncoupling protein 2 and genes involved in fatty acid transport and β-oxidation. In summary, transgenic overexpression of PPARγ in β-cells in diet-induced obesity negatively impacts whole-animal carbohydrate metabolism associated with altered islet lipid content, increased expression of β-oxidative genes, and reduced β-cell mass.

  14. Islet transplantation in rodents: do encapsulated islets really work?

    Directory of Open Access Journals (Sweden)

    Yngrid Ellyn Dias Maciel de Souza

    2011-06-01

    Full Text Available CONTEXT: Diabetes mellitus type I affects around 240 million people in the world and only in the USA 7.8% of the population. It has been estimated that the costs of its complications account for 5% to 10% of the total healthcare spending around the world. According to World Health Organization, 300 million people are expected to develop diabetes mellitus by the year 2025. The pancreatic islet transplantation is expected to be less invasive than a pancreas transplant, which is currently the most commonly used approach. OBJECTIVES: To compare the encapsulated and free islet transplantation in rodents looking at sites of islet implantation, number of injected islets, viability and immunosuppression. METHODS: A literature search was conducted using MEDLINE/PUBMED and SCIELO with terms about islet transplantation in the rodent from 2000 to 2010. We found 2,636 articles but only 56 articles from 2000 to 2010 were selected. RESULTS: In these 56 articles used, 34% were encapsulated and 66% were nonencapsulated islets. Analyzing both types of islets transplantation, the majority of the encapsulated islets were implanted into the peritoneal cavity and the nonencapsulated islets into the liver, through the portal vein. In addition, the great advantage of the peritoneal cavity as the site of islet transplantation is its blood supply. Both vascular endothelial cells and vascular endothelial growth factor were used to stimulate angiogenesis of the islet grafts, increasing the vascularization rapidly after implantation. It also has been proven that there is influence of the capsules, since the larger the capsule more chances there are of central necrosis. In some articles, the use of immunosuppression demonstrated to increase the life expectancy of the graft. CONCLUSION: While significant progress has been made in the islets transplantation field, many obstacles remain to be overcome. Microencapsulation provides a means to transplant islets without

  15. Research Resource: A Dual Proteomic Approach Identifies Regulated Islet Proteins During β-Cell Mass Expansion In Vivo

    DEFF Research Database (Denmark)

    Horn, Signe; Kirkegaard, Jeannette S.; Hoelper, Soraya

    2016-01-01

    Diabetes is characterized by insulin insufficiency due to a relative paucity of functional β-cell mass. Thus, strategies for increasing β-cell mass in situ are sought-after for therapeutic purposes. Pregnancy is a physiological state capable of inducing robust β-cell mass expansion, however, the ...... as upstream regulators of the observed expressional changes. As the first characterization of the islet-proteome during pregnancy, this study provides novel insight into the mechanisms involved in promoting pregnancy-induced β-cell mass expansion and function.[on SciFinder (R)]...

  16. Poloxamer 188 as a supplement to barium cross-linked ultra-high viscosity alginate for immunoisolation of transplanted islet cells

    OpenAIRE

    Mettler, E.; Zimmermann, U.; Hansen, T.; Ehrhart, F.; Zimmermann, H.; Weber, M.M.

    2015-01-01

    Transplantation of Langerhans islets is a potential cure for diabetes mellitus. The main problem for routine clinical use remains the prevention of rejection without drastic side effects. Immuno-isolation is an experimental strategy to prevent graft rejection by separating the transplanted cells from the host immune system using a barrier device. The aim of the current study was to improve the physical features of encapsulated islets in a barium cross-linked ultra-high viscosity alginate by a...

  17. 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

  18. Vascular endothelial growth factor coordinates islet innervation via vascular scaffolding

    Science.gov (United States)

    Reinert, Rachel B.; Cai, Qing; Hong, Ji-Young; Plank, Jennifer L.; Aamodt, Kristie; Prasad, Nripesh; Aramandla, Radhika; Dai, Chunhua; Levy, Shawn E.; Pozzi, Ambra; Labosky, Patricia A.; Wright, Christopher V. E.; Brissova, Marcela; Powers, Alvin C.

    2014-01-01

    Neurovascular alignment is a common anatomical feature of organs, but the mechanisms leading to this arrangement are incompletely understood. Here, we show that vascular endothelial growth factor (VEGF) signaling profoundly affects both vascularization and innervation of the pancreatic islet. In mature islets, nerves are closely associated with capillaries, but the islet vascularization process during embryonic organogenesis significantly precedes islet innervation. Although a simple neuronal meshwork interconnects the developing islet clusters as they begin to form at E14.5, the substantial ingrowth of nerve fibers into islets occurs postnatally, when islet vascularization is already complete. Using genetic mouse models, we demonstrate that VEGF regulates islet innervation indirectly through its effects on intra-islet endothelial cells. Our data indicate that formation of a VEGF-directed, intra-islet vascular plexus is required for development of islet innervation, and that VEGF-induced islet hypervascularization leads to increased nerve fiber ingrowth. Transcriptome analysis of hypervascularized islets revealed an increased expression of extracellular matrix components and axon guidance molecules, with these transcripts being enriched in the islet-derived endothelial cell population. We propose a mechanism for coordinated neurovascular development within pancreatic islets, in which endocrine cell-derived VEGF directs the patterning of intra-islet capillaries during embryogenesis, forming a scaffold for the postnatal ingrowth of essential autonomic nerve fibers. PMID:24574008

  19. The Different Faces of the Pancreatic Islet.

    Science.gov (United States)

    Abdulreda, Midhat H; Rodriguez-Diaz, Rayner; Cabrera, Over; Caicedo, Alejandro; Berggren, Per-Olof

    Type 1 diabetes (T1D) patients who receive pancreatic islet transplant experience significant improvement in their quality-of-life. This comes primarily through improved control of blood sugar levels, restored awareness of hypoglycemia, and prevention of serious and potentially life-threatening diabetes-associated complications, such as kidney failure, heart and vascular disease, stroke, nerve damage, and blindness. Therefore, beta cell replacement through transplantation of isolated islets is an important option in the treatment of T1D. However, lasting success of this promising therapy depends on durable survival and efficacy of the transplanted islets, which are directly influenced by the islet isolation procedures. Thus, isolating pancreatic islets with consistent and reliable quality is critical in the clinical application of islet transplantation.Quality of isolated islets is important in pre-clinical studies as well, as efforts to advance and improve clinical outcomes of islet transplant therapy have relied heavily on animal models ranging from rodents, to pigs, to nonhuman primates. As a result, pancreatic islets have been isolated from these and other species and used in a variety of in vitro or in vivo applications for this and other research purposes. Protocols for islet isolation have been somewhat similar across species, especially, in mammals. However, given the increasing evidence about the distinct structural and functional features of human and mouse islets, using similar methods of islet isolation may contribute to inconsistencies in the islet quality, immunogenicity, and experimental outcomes. This may also contribute to the discrepancies commonly observed between pre-clinical findings and clinical outcomes. Therefore, it is prudent to consider the particular features of pancreatic islets from different species when optimizing islet isolation protocols.In this chapter, we explore the structural and functional features of pancreatic islets from

  20. The influence of maternal islet beta-cell autoantibodies in conjunction with gestational hyperglycemia on neonatal outcomes.

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    Zhe Li

    Full Text Available To determine the predictive value of the presence of maternal islet beta-cell autoantibodies with respect to neonatal outcomes.A total of 311 pregnant women with abnormal 75 g oral glucose tolerance test (OGTT results were enrolled in this study. Maternal glutamic acid decarboxylase autoantibodies (GADA, islet cell autoantibodies (ICA and insulin autoantibodies (IAA were tested in fasting blood both on the day following the routine OGTT and before delivery. The birth weight, Apgar score, blood glucose and outcomes of each neonate were later evaluated and recorded.1. In this study, 33.9% of the pregnant women with gestational hyperglycemia had detectable levels of one or more types of anti-islet cell antibodies in the third trimester. The proportion of women who produced GADA and/or ICA was significantly higher in the group of women with gestational hyperglycemia than in the control group (P<0.05. The groups similarly differed in the proportion of women who tested positive for any anti-islet cell antibody (P<0.05. 2. Of the patients in our study, those who produced GADA exhibited an increase in uterine and umbilical arterial pulsatility indexes (PIs during the third trimesters compared with the control group (P˂0.05. Additionally, an increased frequency of fetal growth restriction (FGR was observed in the infants of women who produced IAA during pregnancy compared with those without autoantibodies (P˂0.05. 3. The rate of newborn admission to the neonatal intensive care unit (NICU was significantly associated with the presence of maternal ICA during the third trimester (OR, 6.36; 95% CI, 1.22-33.26. 4. The incidence of neonatal asphyxia was associated with the presence of maternal GADA in both the second (OR, 10.44; 95% CI, 1.46-74.92 and the third (OR, 8.33; 95% CI, 1.45-47.82 trimesters.Approximately one-third of the women with gestational hyperglycemia produced anti-islet cell antibodies. The incidence of FGR was higher in women with

  1. Tumor-Free Transplantation of Patient-Derived Induced Pluripotent Stem Cell Progeny for Customized Islet Regeneration

    Science.gov (United States)

    El Khatib, Moustafa M.; Ohmine, Seiga; Jacobus, Egon J.; Tonne, Jason M.; Morsy, Salma G.; Holditch, Sara J.; Schreiber, Claire A.; Uetsuka, Koji; Fusaki, Noemi; Wigle, Dennis A.; Terzic, Andre; Kudva, Yogish C.

    2016-01-01

    Human induced pluripotent stem cells (iPSCs) and derived progeny provide invaluable regenerative platforms, yet their clinical translation has been compromised by their biosafety concern. Here, we assessed the safety of transplanting patient-derived iPSC-generated pancreatic endoderm/progenitor cells. Transplantation of progenitors from iPSCs reprogrammed by lentiviral vectors (LV-iPSCs) led to the formation of invasive teratocarcinoma-like tumors in more than 90% of immunodeficient mice. Moreover, removal of primary tumors from LV-iPSC progeny-transplanted hosts generated secondary and metastatic tumors. Combined transgene-free (TGF) reprogramming and elimination of residual pluripotent cells by enzymatic dissociation ensured tumor-free transplantation, ultimately enabling regeneration of type 1 diabetes-specific human islet structures in vivo. The incidence of tumor formation in TGF-iPSCs was titratable, depending on the oncogenic load, with reintegration of the cMYC expressing vector abolishing tumor-free transplantation. Thus, transgene-free cMYC-independent reprogramming and elimination of residual pluripotent cells are mandatory steps in achieving transplantation of iPSC progeny for customized and safe islet regeneration in vivo. Significance Pluripotent stem cell therapy for diabetes relies on the safety as well as the quality of derived insulin-producing cells. Data from this study highlight prominent tumorigenic risks of induced pluripotent stem cell (iPSC) products, especially when reprogrammed with integrating vectors. Two major underlying mechanisms in iPSC tumorigenicity are residual pluripotent cells and cMYC overload by vector integration. This study also demonstrated that combined transgene-free reprogramming and enzymatic dissociation allows teratoma-free transplantation of iPSC progeny in the mouse model in testing the tumorigenicity of iPSC products. Further safety assessment and improvement in iPSC specification into a mature β cell phenotype

  2. Tumor-Free Transplantation of Patient-Derived Induced Pluripotent Stem Cell Progeny for Customized Islet Regeneration.

    Science.gov (United States)

    El Khatib, Moustafa M; Ohmine, Seiga; Jacobus, Egon J; Tonne, Jason M; Morsy, Salma G; Holditch, Sara J; Schreiber, Claire A; Uetsuka, Koji; Fusaki, Noemi; Wigle, Dennis A; Terzic, Andre; Kudva, Yogish C; Ikeda, Yasuhiro

    2016-05-01

    Human induced pluripotent stem cells (iPSCs) and derived progeny provide invaluable regenerative platforms, yet their clinical translation has been compromised by their biosafety concern. Here, we assessed the safety of transplanting patient-derived iPSC-generated pancreatic endoderm/progenitor cells. Transplantation of progenitors from iPSCs reprogrammed by lentiviral vectors (LV-iPSCs) led to the formation of invasive teratocarcinoma-like tumors in more than 90% of immunodeficient mice. Moreover, removal of primary tumors from LV-iPSC progeny-transplanted hosts generated secondary and metastatic tumors. Combined transgene-free (TGF) reprogramming and elimination of residual pluripotent cells by enzymatic dissociation ensured tumor-free transplantation, ultimately enabling regeneration of type 1 diabetes-specific human islet structures in vivo. The incidence of tumor formation in TGF-iPSCs was titratable, depending on the oncogenic load, with reintegration of the cMYC expressing vector abolishing tumor-free transplantation. Thus, transgene-free cMYC-independent reprogramming and elimination of residual pluripotent cells are mandatory steps in achieving transplantation of iPSC progeny for customized and safe islet regeneration in vivo. Pluripotent stem cell therapy for diabetes relies on the safety as well as the quality of derived insulin-producing cells. Data from this study highlight prominent tumorigenic risks of induced pluripotent stem cell (iPSC) products, especially when reprogrammed with integrating vectors. Two major underlying mechanisms in iPSC tumorigenicity are residual pluripotent cells and cMYC overload by vector integration. This study also demonstrated that combined transgene-free reprogramming and enzymatic dissociation allows teratoma-free transplantation of iPSC progeny in the mouse model in testing the tumorigenicity of iPSC products. Further safety assessment and improvement in iPSC specification into a mature β cell phenotype would lead to

  3. Morbidity of total pancreatectomy with islet cell auto-transplantation compared to total pancreatectomy alone.

    Science.gov (United States)

    Bhayani, Neil H; Enomoto, Laura M; Miller, Jennifer L; Ortenzi, Gail; Kaifi, Jussuf T; Kimchi, Eric T; Staveley-O'Carroll, Kevin F; Gusani, Niraj J

    2014-06-01

    In pancreatitis, total pancreatectomy (TP) is an effective treatment for refractory pain. Islet cell auto-transplantation (IAT) may mitigate resulting endocrinopathy. Short-term morbidity data for TP + IAT and comparisons with TP are limited. This study, using 2005-2011 National Surgical Quality Improvement Program data, examined patients with pancreatitis or benign neoplasms. Morbidity after TP alone was compared with that after TP + IAT. In 126 patients (40%) undergoing TP and 191 (60%) patients undergoing TP + IAT, the most common diagnosis was chronic pancreatitis. Benign neoplasms were present in 46 (14%) patients, six of whom underwent TP + IAT. Patients in the TP + IAT group were younger and had fewer comorbidities than those in the TP group. Despite this, major morbidity was more frequent after TP + IAT than after TP [n = 79 (41%) versus n = 36 (29%); P = 0.020]. Transfusions were more common after TP + IAT [n = 39 (20%) versus n = 9 (7%); P = 0.001], as was longer hospitalization (13 days versus 9 days; P < 0.0001). There was no difference in mortality. This study is the only comparative, multicentre study of TP and TP + IAT. The TP + IAT group experienced higher rates of major morbidity and transfusion, and longer hospitalizations. Better data on the longterm benefits of TP + IAT are needed. In the interim, this study should inform physicians and patients regarding the perioperative risks of TP + IAT. © 2013 International Hepato-Pancreato-Biliary Association.

  4. Human umbilical cord matrix-derived stem cells exert trophic effects on β-cell survival in diabetic rats and isolated islets

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    Yunting Zhou

    2015-12-01

    Full Text Available Human umbilical cord matrix-derived stem cells (uMSCs, owing to their cellular and procurement advantages compared with mesenchymal stem cells derived from other tissue sources, are in clinical trials to treat type 1 (T1D and type 2 diabetes (T2D. However, the therapeutic basis remains to be fully understood. The immunomodulatory property of uMSCs could explain the use in treating T1D; however, the mere immune modulation might not be sufficient to support the use in T2D. We thus tested whether uMSCs could exert direct trophic effects on β-cells. Infusion of uMSCs into chemically induced diabetic rats prevented hyperglycemic progression with a parallel preservation of islet size and cellularity, demonstrating the protective effect of uMSCs on β-cells. Mechanistic analyses revealed that uMSCs engrafted long-term in the injured pancreas and the engraftment markedly activated the pancreatic PI3K pathway and its downstream anti-apoptotic machinery. The pro-survival pathway activation was associated with the expression and secretion of β-cell growth factors by uMSCs, among which insulin-like growth factor 1 (IGF1 was highly abundant. To establish the causal relationship between the uMSC-secreted factors and β-cell survival, isolated rat islets were co-cultured with uMSCs in the transwell system. Co-culturing improved the islet viability and insulin secretion. Furthermore, reduction of uMSC-secreted IGF1 via siRNA knockdown diminished the protective effects on islets in the co-culture. Thus, our data support a model whereby uMSCs exert trophic effects on islets by secreting β-cell growth factors such as IGF1. The study reveals a novel therapeutic role of uMSCs and suggests that multiple mechanisms are employed by uMSCs to treat diabetes.

  5. siRNA-mediated silencing of bFGF gene inhibits the proliferation, migration, and invasion of human pituitary adenoma cells.

    Science.gov (United States)

    Zhou, Kai; Fan, Yan-Dong; Duysenbi, Serick; Wu, Peng-Fei; Feng, Zhao-Hai; Qian, Zheng; Zhang, Ting-Rong

    2017-06-01

    Human pituitary adenoma is one of the most common intracranial tumors with an incidence as high as 16.7%. Recent evidence has hinted a relationship between growth factors of pituitary or hypothalamic origin and proliferation of human pituitary adenoma cells. This study explores the effects of small interfering RNA-mediated silencing of basic fibroblast growth factor gene on the proliferation, migration, and invasion of human pituitary adenoma cells. Human pituitary adenoma tissues were collected to obtain human pituitary adenoma cells. The basic fibroblast growth factor silencing interference plasmid was constructed, and the human pituitary adenoma cells were transfected and assigned as basic fibroblast growth factor-small interfering RNA, negative control-small interfering RNA, and blank groups. The quantitative real-time polymerase chain reaction and Western blotting were carried out to detect the expression of basic fibroblast growth factor, pituitary tumor transforming gene, vascular endothelial growth factor, cluster of differentiation 147, and matrix metalloproteinase 9. Cell Counting Kit-8 assay was conducted to observe cell proliferation at 0, 24, 48, and 72 h. Flow cytometry was used to determine cell cycle. Transwell and scratch test were applied to detect the invasion and migration of pituitary adenoma cells. Protein kinase C activity was detected. In comparison with the blank group, the basic fibroblast growth factor-small interfering RNA group showed reduced messenger RNA and protein expression of basic fibroblast growth factor, reduced cell viability at 24, 48, and 72 h, increased cells in G0/G1 stage, declined cells in S and G2/M stages, decreased number of cell migration, shortened migrating distance, reduced protein kinase C activity, and decreased expression of pituitary tumor transforming gene, vascular endothelial growth factor, cluster of differentiation 147, and matrix metalloproteinase 9. However, the negative control-small interfering

  6. Young capillary vessels rejuvenate aged pancreatic islets

    Science.gov (United States)

    Almaça, Joana; Molina, Judith; Arrojo e Drigo, Rafael; Abdulreda, Midhat H.; Jeon, Won Bae; Berggren, Per-Olof; Caicedo, Alejandro; Nam, Hong Gil

    2014-01-01

    Pancreatic islets secrete hormones that play a key role in regulating blood glucose levels (glycemia). Age-dependent impairment of islet function and concomitant dysregulation of glycemia are major health threats in aged populations. However, the major causes of the age-dependent decline of islet function are still disputed. Here we demonstrate that aging of pancreatic islets in mice and humans is notably associated with inflammation and fibrosis of islet blood vessels but does not affect glucose sensing and the insulin secretory capacity of islet beta cells. Accordingly, when transplanted into the anterior chamber of the eye of young mice with diabetes, islets from old mice are revascularized with healthy blood vessels, show strong islet cell proliferation, and fully restore control of glycemia. Our results indicate that beta cell function does not decline with age and suggest that islet function is threatened by an age-dependent impairment of islet vascular function. Strategies to mitigate age-dependent dysregulation in glycemia should therefore target systemic and/or local inflammation and fibrosis of the aged islet vasculature. PMID:25404292

  7. Stem cells in the canine pituitary gland and in pituitary adenomas

    NARCIS (Netherlands)

    van Rijn, Sarah J|info:eu-repo/dai/nl/392860163; Tryfonidou, Marianna A|info:eu-repo/dai/nl/24306599X; Hanson, Jeanette M; Penning, Louis C|info:eu-repo/dai/nl/110369181; Meij, Björn P|info:eu-repo/dai/nl/164045805

    2013-01-01

    Cushing's disease (CD) or pituitary-dependent hypercortisolism is a common endocrinopathy in dogs, with an estimated prevalence of 1 or 2 in 1000 dogs per year. It is caused by an adrenocorticotropic hormone secreting adenoma in the pars distalis or pars intermedia of the pituitary gland. The

  8. 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 (ppathophysiology 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.

  9. Adenoma de células basales parotídeo: Revisión a propósito de cuatro casos Basal cell adenoma of the parotid: A revision based on four cases

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    M.J. Pastor Fortea

    2005-04-01

    Full Text Available El adenoma de células basales es un tipo específico de adenoma con una apariencia histológica uniforme y monomorfa, en el que predominan las células basaliodes sin el componente mixocondroide del tumor mixto. Atendiendo a su morfología pueden ser divididos en cuatro subtipos: sólido, tubular, trabecular y membranoso. Presentamos cuatro casos de adenoma de células basales localizados en glándula parótida: uno de tipo sólido, uno de tipo trabecular y dos de tipo membranoso, tratados mediante parotidectomía superficial conservadora en todos los casos. Esta división en distintos patrones morfológicos tiene una finalidad descriptiva, salvo en el subtipo membranoso por su mayor tendencia a la multifocalidad y a la recidiva, su ocasional transformación maligna, así como por su posible asociación en un tercio de los casos a tumores ecrinos dermales. Esto implica un seguimiento más estrecho y un despistaje de posibles lesiones cutáneas asociadas.The basal cell adenoma is a specific type of adenoma, with a uniform, monomorphous histologic appearance that is dominated by basaloid cells and that does not have the myxochondroid tissue characteristic of mixed tumors. It may be divided on the basis of its morphologic pattern into four subtypes: solid, tubular, trabecular and membranous. We report four cases of basal cell adenoma subdivided as follows: one solid, one trabecular and two membranous subtypes. In all cases a conservative superficial parotidectomy was the treatment. Morphologic identification of the specific subtype is for descriptive purposes, except in the case of the membranous type, due to its tendency to be multifocal, its high recurrence rate, its occasional malignant transformation and its possible association in about onethird of the reported cases with dermal cylindromas. A close followup and screening of skin lesions is suggested for these tumors.

  10. Effects of micro-encapsulation on morphology and endocrine function of cryopreserved neonatal porcine islet-like cell clusters.

    Science.gov (United States)

    Murakami, M; Satou, H; Kimura, T; Kobayashi, T; Yamaguchi, A; Nakagawara, G; Iwata, H

    2000-10-27

    For the success of clinical islets transplantation, the development of a long-term storage method is necessary. However, the structure of digested islets is scanty for culture and cryopreservation. In this study, the effect of micro-encapsulation to cryopreserved porcine islet-like cell clusters (ICCs) was investigated. The ICCs prepared from neonatal pigs by collagenase digestion and culture technique were cryopreserved and micro-encapsulated in 5% agarose membranes. After cryopreservation, ICC cultured without encapsulation (group A) and cultured with encapsulation (group B) were assessed by comparison with no cryopreserved ICC (control) both in vitro by static incubation test and in vivo in a xenotransplantation study. Micro-encapsulation was able to maintain the fine morphology and the number of ICCs of group B after 7 days of culture. There were not significant differences in insulin secretion of group B and control on day 1 and 7 of culture (1 day:11+/-0.99, 7 days: 5.30+/-1.08 microU/ICC/hr NS versus control). On day 7 of culture, the retrieval rate of group B (105.2+/-9.8%) is obviously higher compared with group A (63.0+/-6.3%). In the xenotransplatation model, the ICCs of group B showed long survival time (7.9+/-0.4 weeks) and good transplantation effect. Our study suggests that micro-encapsulation is one of the useful method for cryopreserved ICC to maintain the fine morphology and effectively recover the endocrine function.

  11. Safety and tolerability of the T-cell depletion protocol coupled with anakinra and etanercept for clinical islet cell transplantation.

    Science.gov (United States)

    Takita, Morihito; Matsumoto, Shinichi; Shimoda, Masayuki; Chujo, Daisuke; Itoh, Takeshi; Sorelle, Jeffrey A; Purcell, Kerri; Onaca, Nicholas; Naziruddin, Bashoo; Levy, Marlon F

    2012-01-01

    Islet cell transplantation (ICT) is a promising approach to cure patients with type 1 diabetes. We have implemented a new immunosuppression protocol with antithymoglobulin plus anti-inflammatory agents of anakinra and eternacept for induction and tacrolimus plus mycophenolate mofetil for maintenance [T-cell depletion with anti-inflammatory (TCD-AI) protocol], resulting in successful single-donor ICT. Eight islet recipients with type 1 diabetes reported adverse events (AEs) monthly. AEs were compared between three groups: first infusion with the TCD-AI protocol (TCD-AI-1st) and first and second infusion with the Edmonton-type protocol (Edmonton-1st and Edmonton-2nd). The incidence of symptomatic AEs within the initial three months in the TCD-AI-1st group was less than in the Edmonton-1st and Edmonton-2nd groups, with a marginally significant difference (mean ± SE: 5.5 ± 0.3, 7.5 ± 0.5, and 8.3 ± 1.3, respectively; p = 0.07). A significant reduction in liver enzyme elevation after ICT was found in the TCD-AI-1st group compared with the Edmonton-1st and Edmonton-2nd groups (p < 0.05). Because of AEs, all patients in the Edmonton protocol eventually converted to the TCD-AI protocol, whereas all patients tolerated the TCD-AI protocol. TCD-AI protocol can be tolerated for successful ICT, although this study includes small cohort, and large population trial should be taken. © 2012 John Wiley & Sons A/S.

  12. Safety and Tolerability of the T Cell Depletion Protocol Coupled with Anakinra and Etanercept for Clinical Islet Cell Transplantation

    Science.gov (United States)

    Takita, Morihito; Matsumoto, Shinichi; Shimoda, Masayuki; Chujo, Daisuke; Itoh, Takeshi; SoRelle, Jeffrey A.; Purcell, Kerri; Onaca, Nicholas; Naziruddin, Bashoo; Levy, Marlon F.

    2014-01-01

    Background Islet cell transplantation (ICT) is a promising approach to cure patients with type 1 diabetes. We have implemented a new immunosuppression protocol with antithymoglobulin plus antiinflammatory agents of anakinra and eternacept for induction, and tacrolimus plus mycophenolate mofetil for maintenance (T cell depletion with antiinflammatory [TCD-AI] protocol), resulting in successful single-donor ICT. Methods Eight islet recipients with type 1 diabetes reported adverse events (AEs) monthly. AEs were compared among three groups: first infusion with the TCD-AI protocol (TCD-AI-1st) and first and second infusion with the Edmonton-type protocol (Edmonton-1st and Edmonton-2nd). Results The incidence of symptomatic AEs within the initial 3 months in the TCD-AI-1st group was less than in the Edmonton-1st and -2nd groups, with a marginally significant difference (mean ± S.E.: 5.5±0.3, 7.5±0.5, and 8.3±1.3, respectively; p = 0.07). A significant reduction in liver enzyme elevation after ICT was found in the TCD-AI-1st group compared to the Edmonton-1st and -2nd groups (p < 0.05). Due to AEs, all patients in the Edmonton protocol eventually converted to the TCD-AI protocol, whereas all patients tolerated the TCD-AI protocol. Conclusions TCD-AI protocol can be tolerated for successful ICT although this study includes small cohort and large population trial should be taken. PMID:23061757

  13. Serotonin- and Dopamine-Related Gene Expression in db/db Mice Islets and in MIN6 β-Cells Treated with Palmitate and Oleate

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    L. R. Cataldo

    2016-01-01

    Full Text Available High circulating nonesterified fatty acids (NEFAs concentration, often reported in diabetes, leads to impaired glucose-stimulated insulin secretion (GSIS through not yet well-defined mechanisms. Serotonin and dopamine might contribute to NEFA-dependent β-cell dysfunction, since extracellular signal of these monoamines decreases GSIS. Moreover, palmitate-treated β-cells may enhance the expression of the serotonin receptor Htr2c, affecting insulin secretion. Additionally, the expression of monoamine-oxidase type B (Maob seems to be lower in islets from humans and mice with diabetes compared to nondiabetic islets, which may lead to increased monoamine concentrations. We assessed the expression of serotonin- and dopamine-related genes in islets from db/db and wild-type (WT mice. In addition, the effect of palmitate and oleate on the expression of such genes, 5HT content, and GSIS in MIN6 β-cell was determined. Lower Maob expression was found in islets from db/db versus WT mice and in MIN6 β-cells in response to palmitate and oleate treatment compared to vehicle. Reduced 5HT content and impaired GSIS in response to palmitate (−25%; p<0.0001 and oleate (−43%; p<0.0001 were detected in MIN6 β-cells. In conclusion, known defects of GSIS in islets from db/db mice and MIN6 β-cells treated with NEFAs are accompanied by reduced Maob expression and reduced 5HT content.

  14. Lycopene and Beta-Carotene Induce Growth Inhibition and Proapoptotic Effects on ACTH-Secreting Pituitary Adenoma Cells

    Science.gov (United States)

    Leite de Oliveira, Felipe; Soares, Nathália; de Mattos, Rômulo Medina; Hecht, Fábio; Dezonne, Rômulo Sperduto; Vairo, Leandro; Goldenberg, Regina Coeli dos Santos; Gomes, Flávia Carvalho Alcântara; de Carvalho, Denise Pires; Gadelha, Mônica R.; Nasciutti, Luiz Eurico; Miranda-Alves, Leandro

    2013-01-01

    Pituitary adenomas comprise approximately 10–15% of intracranial tumors and result in morbidity associated with altered hormonal patterns, therapy and compression of adjacent sella turcica structures. The use of functional foods containing carotenoids contributes to reduce the risk of chronic diseases such as cancer and vascular disorders. In this study, we evaluated the influence of different concentrations of beta-carotene and lycopene on cell viability, colony formation, cell cycle, apoptosis, hormone secretion, intercellular communication and expression of connexin 43, Skp2 and p27kip1 in ACTH-secreting pituitary adenoma cells, the AtT20 cells, incubated for 48 and 96 h with these carotenoids. We observed a decrease in cell viability caused by the lycopene and beta-carotene treatments; in these conditions, the clonogenic ability of the cells was also significantly decreased. Cell cycle analysis revealed that beta-carotene induced an increase of the cells in S and G2/M phases; furthermore, lycopene increased the proportion of these cells in G0/G1 while decreasing the S and G2/M phases. Also, carotenoids induced apoptosis after 96 h. Lycopene and beta-carotene decreased the secretion of ACTH in AtT20 cells in a dose-dependent manner. Carotenoids blocked the gap junction intercellular communication. In addition, the treatments increased the expression of phosphorylated connexin43. Finally, we also demonstrate decreased expression of S-phase kinase-associated protein 2 (Skp2) and increased expression of p27kip1 in carotenoid-treated cells. These results show that lycopene and beta-carotene were able to negatively modulate events related to the malignant phenotype of AtT-20 cells, through a mechanism that could involve changes in the expression of connexin 43, Skp2 and p27kip1; and suggest that these compounds might provide a novel pharmacological approach to the treatment of Cushing’s disease. PMID:23667519

  15. Lycopene and beta-carotene induce growth inhibition and proapoptotic effects on ACTH-secreting pituitary adenoma cells.

    Directory of Open Access Journals (Sweden)

    Natália F Haddad

    Full Text Available Pituitary adenomas comprise approximately 10-15% of intracranial tumors and result in morbidity associated with altered hormonal patterns, therapy and compression of adjacent sella turcica structures. The use of functional foods containing carotenoids contributes to reduce the risk of chronic diseases such as cancer and vascular disorders. In this study, we evaluated the influence of different concentrations of beta-carotene and lycopene on cell viability, colony formation, cell cycle, apoptosis, hormone secretion, intercellular communication and expression of connexin 43, Skp2 and p27(kip1 in ACTH-secreting pituitary adenoma cells, the AtT20 cells, incubated for 48 and 96 h with these carotenoids. We observed a decrease in cell viability caused by the lycopene and beta-carotene treatments; in these conditions, the clonogenic ability of the cells was also significantly decreased. Cell cycle analysis revealed that beta-carotene induced an increase of the cells in S and G2/M phases; furthermore, lycopene increased the proportion of these cells in G0/G1 while decreasing the S and G2/M phases. Also, carotenoids induced apoptosis after 96 h. Lycopene and beta-carotene decreased the secretion of ACTH in AtT20 cells in a dose-dependent manner. Carotenoids blocked the gap junction intercellular communication. In addition, the treatments increased the expression of phosphorylated connexin43. Finally, we also demonstrate decreased expression of S-phase kinase-associated protein 2 (Skp2 and increased expression of p27(kip1 in carotenoid-treated cells. These results show that lycopene and beta-carotene were able to negatively modulate events related to the malignant phenotype of AtT-20 cells, through a mechanism that could involve changes in the expression of connexin 43, Skp2 and p27(kip1; and suggest that these compounds might provide a novel pharmacological approach to the treatment of Cushing's disease.

  16. Apelin is a novel islet peptide

    DEFF Research Database (Denmark)

    Ringström, Camilla; Nitert, Marloes Dekker; Bennet, Hedvig

    2010-01-01

    Apelin, a recently discovered peptide with wide tissue distribution, regulates feeding behavior, improves glucose utilization, and inhibits insulin secretion. We examined whether apelin is expressed in human islets, as well as in normal and type 2 diabetic (T2D) animal islets. Further, we studied...... islet apelin regulation and the effect of apelin on insulin secretion. Apelin expression and regulation was examined in human and animal specimens using immunocytochemistry, in situ hybridization, and real-time PCR. Insulin secretion was studied in INS-1 (832/13) clonal beta cells. APJ......-receptor expression was studied using real-time PCR. In human and murine islets apelin was predominantly expressed in beta cells and alpha cells; a subpopulation of the PP cells in human islets also harbored apelin. In porcine and feline islets apelin was mainly expressed in beta cells. APJ-receptor expression...

  17. Obesity, islet cell autoimmunity, and cardiovascular risk factors in youth at onset of type 1 autoimmune diabetes.

    Science.gov (United States)

    Cedillo, Maribel; Libman, Ingrid M; Arena, Vincent C; Zhou, Lei; Trucco, Massimo; Ize-Ludlow, Diego; Pietropaolo, Massimo; Becker, Dorothy J

    2015-01-01

    The current increase in childhood type 1 diabetes (T1D) and obesity has led to two conflicting hypotheses and conflicting reports regarding the effects of overweight on initiation and spreading of islet cell autoimmunity vs earlier clinical manifestation of preexisting autoimmune β-cell damage driven by excess weight. The objective of the study was to address the question of whether the degree of β-cell autoimmunity and age are related to overweight at diabetes onset in a large cohort of T1D youth. This was a prospective cross-sectional study of youth with autoimmune T1D consecutively recruited at diabetes onset. The study was conducted at a regional academic pediatric diabetes center. Two hundred sixty-three consecutive children younger than 19 years at onset of T1D participated in the study. Relationships between body mass index and central obesity (waist circumference and waist to height ratio) and antigen spreading (islet cell autoantibody number), age, and cardiovascular (CVD) risk factors examined at onset and/or 3 months after the diagnosis were measured. There were no significant associations between number of autoantibodies with measures of adiposity. Age relationships revealed that a greater proportion of those with central obesity (21%) were in the youngest age group (0-4 y) compared with those without central obesity (6%) (P = .001). PATIENTS with central obesity had increased CVD risk factors and higher onset C-peptide levels (P obesity accelerates progression of autoantibody spreading once autoimmunity, marked by standard islet cell autoantibody assays, is present. Central obesity was present in almost one-third of the subjects and was associated with early CVD risk markers already at onset.

  18. Co-transplantation of endothelial progenitor cells and pancreatic islets to induce long-lasting normoglycemia in streptozotocin-treated diabetic rats.

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    Paola Quaranta

    Full Text Available Graft vascularization is a crucial step to obtain stable normoglycemia in pancreatic islet transplantation. Endothelial progenitor cells (EPCs contribute to neoangiogenesis and to the revascularization process during ischaemic events and play a key role in the response to pancreatic islet injury. In this work we co-transplanted EPCs and islets in the portal vein of chemically-induced diabetic rats to restore islet vascularization and to improve graft survival. Syngenic islets were transplanted, either alone or with EPCs derived from green fluorescent protein (GFP transgenic rats, into the portal vein of streptozotocin-induced diabetic rats. Blood glucose levels were monitored and intraperitoneal glucose tolerance tests were performed. Real time-PCR was carried out to evaluate the gene expression of angiogenic factors. Diabetic-induced rats showed long-lasting (6 months normoglycemia upon co-transplantation of syngenic islets and EPCs. After 3-5 days from transplantation, hyperglycaemic levels dropped to normal values and lasted unmodified as long as they were checked. Further, glucose tolerance tests revealed the animals' ability to produce insulin on-demand as indexed by a prompt response in blood glucose clearance. Graft neovascularization was evaluated by immunohistochemistry: for the first time the measure of endothelial thickness revealed a donor-EPC-related neovascularization supporting viable islets up to six months after transplant. Our results highlight the importance of a newly formed viable vascular network together with pancreatic islets to provide de novo adequate supply in order to obtain enduring normoglycemia and prevent diabetes-related long-term health hazards.

  19. Co-transplantation of endothelial progenitor cells and pancreatic islets to induce long-lasting normoglycemia in streptozotocin-treated diabetic rats.

    Science.gov (United States)

    Quaranta, Paola; Antonini, Sara; Spiga, Saturnino; Mazzanti, Benedetta; Curcio, Michele; Mulas, Giovanna; Diana, Marco; Marzola, Pasquina; Mosca, Franco; Longoni, Biancamaria

    2014-01-01

    Graft vascularization is a crucial step to obtain stable normoglycemia in pancreatic islet transplantation. Endothelial progenitor cells (EPCs) contribute to neoangiogenesis and to the revascularization process during ischaemic events and play a key role in the response to pancreatic islet injury. In this work we co-transplanted EPCs and islets in the portal vein of chemically-induced diabetic rats to restore islet vascularization and to improve graft survival. Syngenic islets were transplanted, either alone or with EPCs derived from green fluorescent protein (GFP) transgenic rats, into the portal vein of streptozotocin-induced diabetic rats. Blood glucose levels were monitored and intraperitoneal glucose tolerance tests were performed. Real time-PCR was carried out to evaluate the gene expression of angiogenic factors. Diabetic-induced rats showed long-lasting (6 months) normoglycemia upon co-transplantation of syngenic islets and EPCs. After 3-5 days from transplantation, hyperglycaemic levels dropped to normal values and lasted unmodified as long as they were checked. Further, glucose tolerance tests revealed the animals' ability to produce insulin on-demand as indexed by a prompt response in blood glucose clearance. Graft neovascularization was evaluated by immunohistochemistry: for the first time the measure of endothelial thickness revealed a donor-EPC-related neovascularization supporting viable islets up to six months after transplant. Our results highlight the importance of a newly formed viable vascular network together with pancreatic islets to provide de novo adequate supply in order to obtain enduring normoglycemia and prevent diabetes-related long-term health hazards.

  20. The use of multiparametric monitoring during islet cell isolation and culture: a potential tool for in-process corrections of critical physiological factors.

    Science.gov (United States)

    Fraker, Chris; Montelongo, Jorge; Szust, Joel; Khan, Aisha; Ricordi, Camillo

    2004-01-01

    Variables such as pH, pCO2, and PO2 have been established in the literature as critical factors that could affect the outcome of the islet cell processing and, therefore, the quality of the cells that could be transplanted. This report describes a highly accurate continuous multiparametric monitoring system and its evaluation for continuous monitoring of physiological variables during critical steps of the islet isolation procedure as well as during in vitro culture of the insulin-producing cells. Close monitoring of these variables could be of assistance to improve the outcome of islet cell processing, allowing to identify as soon as possible problems that could be corrected during the procedure, as well as during in vitro preservation, or shipment to remote sites.

  1. Isolated islets in diabetes research.

    Science.gov (United States)

    Bhonde, R; Shukla, R C; Kanitkar, M; Shukla, R; Banerjee, M; Datar, S

    2007-03-01

    This review highlights some recent developments and diversified applications of islets in diabetes research as they are rapidly emerging as a model system in biomedical and biotechnological research. Isolated islets have formed an effective in vitro model in antidiabetic drug development programme, screening of potential hypoglycaemic agents and for investigating their mechanisms of action. Yet another application of isolated islets could be to understand the mechanisms of beta cell death in vitro and to identify the sites of intervention for possible cytoprotection. Advances in immunoisolation and immunomodulation protocols have made xeno-transplantation feasible without immunosuppression thus increasing the availability of islets. Research in the areas of pancreatic and non pancreatic stem cells has given new hope to diabetic subjects to renew their islet cell mass for the possible cure of diabetes. Investigations of the factors leading to differentiation of pancreatic stem/progenitor cells would be of interest as they are likely to induce pancreatic regeneration in diabetics. Similarly search for the beta cell protective agents has a great future in preservation of residual beta cell mass left after diabetogenic insults. We have detailed various applications of islets in diabetes research in context of their current status, progress and future challenges and long term prospects for a cure.

  2. Visual Neurons in the Superior Colliculus Innervated by Islet2+ or Islet2− Retinal Ganglion Cells Display Distinct Tuning Properties

    Directory of Open Access Journals (Sweden)

    Rachel B. Kay

    2017-10-01

    Full Text Available Throughout the visual system, different subtypes of neurons are tuned to distinct aspects of the visual scene, establishing parallel circuits. Defining the mechanisms by which such tuning arises has been a long-standing challenge for neuroscience. To investigate this, we have focused on the retina’s projection to the superior colliculus (SC, where multiple visual neuron subtypes have been described. The SC receives inputs from a variety of retinal ganglion cell (RGC subtypes; however, which RGCs drive the tuning of different SC neurons remains unclear. Here, we pursued a genetic approach that allowed us to determine the tuning properties of neurons innervated by molecularly defined subpopulations of RGCs. In homozygous Islet2-EphA3 knock-in (Isl2EA3/EA3 mice, Isl2+ and Isl2− RGCs project to non-overlapping sub-regions of the SC. Based on molecular and anatomic data, we show that significantly more Isl2− RGCs are direction-selective (DS in comparison with Isl2+ RGCs. Targeted recordings of visual responses from each SC sub-region in Isl2EA3/EA3 mice revealed that Isl2− RGC-innervated neurons were significantly more DS than those innervated by Isl2+ RGCs. Axis-selective (AS neurons were found in both sub-regions, though AS neurons innervated by Isl2+ RGCs were more tightly tuned. Despite this segregation, DS and AS neurons innervated by Isl2+ or Isl2− RGCs did not differ in their spatial summation or spatial frequency (SF tuning. Further, we did not observe alterations in receptive field (RF size or structure of SC neurons innervated by Isl2+ or Isl2− RGCs. Together, these data show that innervation by Isl2+ and Isl2− RGCs results in distinct tuning in the SC and set the stage for future studies investigating the mechanisms by which these circuits are built.

  3. 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.

  4. Nonfunctional Islet Cell Tumor of the Pancreas in a Patient with Tuberous Sclerosis: A Case Report with Literature Review

    Directory of Open Access Journals (Sweden)

    Aysegul Cansu

    2014-01-01

    Full Text Available Islet cell tumors (ICTs are rare tumors of the pancreas. Association of this type of tumor with tuberous sclerosis is extremely rare. Only 13 cases of pancreatic ICT with tuberous sclerosis have so far been documented in the literature. However, awareness of the association of tuberous sclerosis and ICT is important for early diagnosis and appropriate treatment of this condition. This article presents the case of a 63-year-old female with angiomyolipoma (AML of the kidney and liver, calcified subependymal nodules and a large mass in the pancreas, which was proven to be an ICT on histopathological examination.

  5. Baicalein Protects against Type 2 Diabetes via Promoting Islet β-Cell Function in Obese Diabetic Mice

    Directory of Open Access Journals (Sweden)

    Yu Fu

    2014-01-01

    Full Text Available In both type 1 (T1D and type 2 diabetes (T2D, the deterioration of glycemic control over time is primarily caused by an inadequate mass and progressive dysfunction of β-cell, leading to the impaired insulin secretion. Here, we show that dietary supplementation of baicalein, a flavone isolated from the roots of Chinese herb Scutellaria baicalensis, improved glucose tolerance and enhanced glucose-stimulated insulin secretion (GSIS in high-fat diet (HFD- induced middle-aged obese mice. Baicalein had no effect on food intake, body weight gain, circulating lipid profile, and insulin sensitivity in obese mice. Using another mouse model of type 2 diabetes generated by high-fat diet (HFD feeding and low doses of streptozotocin injection, we found that baicalein treatment significantly improved hyperglycemia, glucose tolerance, and blood insulin levels in these middle-aged obese diabetic mice, which are associated with the improved islet β-cell survival and mass. In the in vitro studies, baicalein significantly augmented GSIS and promoted viability of insulin-secreting cells and human islets cultured either in the basal medium or under chronic hyperlipidemic condition. These results demonstrate that baicalein may be a naturally occurring antidiabetic agent by directly modulating pancreatic β-cell function.

  6. Disturbed α-Cell Function in Mice with β-Cell Specific Overexpression of Human Islet Amyloid Polypeptide

    Directory of Open Access Journals (Sweden)

    Bo Ahrén

    2008-01-01

    Full Text Available Exogenous administration of islet amyloid polypeptide (IAPP has been shown to inhibit both insulin and glucagon secretion. This study examined α-cell function in mice with β-cell specific overexpression of human IAPP (hIAPP after an oral protein gavage (75 mg whey protein/mouse. Baseline glucagon levels were higher in transgenic mice (41±4.0 pg/mL, n=6 than in wildtype animals (19±5.1 pg/mL, n=5, P=.015. In contrast, the glucagon response to protein was impaired in transgenic animals (21±2.7 pg/mL in transgenic mice versus 38±5.7 pg/mL in wildtype mice at 15 minutes; P=.027. Baseline insulin levels did not differ between the groups, while the insulin response, as the glucagon response, was impaired after protein challenge (P=.018. Glucose levels were not different between the groups and did not change significantly after protein gavage. Acetaminophen was given through gavage to the animals (2 mg/mouse to estimate gastric emptying. The plasma acetaminophen profile was similar in the two groups of mice. We conclude that disturbances in glucagon secretion exist in mice with β-cell specific overexpression of human IAPP, which are not secondary to changes in gastric emptying. The reduced glucagon response to protein challenge may reflect a direct inhibitory influence of hIAPP on glucagon secretion.

  7. 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; Said, Hamid M

    2014-08-01

    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. Copyright © 2014 the American Physiological Society.

  8. 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.

  9. Inhibition of islet amyloid polypeptide fibril formation by selenium-containing phycocyanin and prevention of beta cell apoptosis.

    Science.gov (United States)

    Li, Xiaoling; Ma, Lijuan; Zheng, Wenjie; Chen, Tianfeng

    2014-10-01

    Human islet amyloid polypeptide (hIAPP) fibril is the major constituent of amyloid deposits in pancreatic islets of type 2 diabetes. Misfolding and hIAPP fibril formation are thought to be important in the pathogenesis of diabetes. Studies have showed that selenium-containing phycocyanin (Se-PC) inhibited the fibrillation of hIAPP to form nanoscale particles, which is mainly by interfering with the combination between hIAPP. Small nanoscale oligomers tended to grow into larger nanoparticles and the size of nanoparticles increased with the incubation time. By interfering with the fibrillation of hIAPP and altering the structure, Se-PC alleviated hIAPP-induced cell apoptosis. Meantime, generation of ROS produced during the fibrillation process was inhibited, which was proposed to be the main factor for the hIAPP-cytotoxicity in beta cells. Taken together, Se-PC inhibited hIAPP fibrillation, thus suppressed the formation of ROS to show protective effect on hIAPP mediated cell apoptosis. Our studies provide useful information for our understanding of the interaction mechanisms of Se-PC on hIAPP structure and protective mechanisms on hIAPP cytotoxicity, presenting useful candidate for anti-diabetes drug development. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. In Vivo Immunogenic Response to Allogeneic Mesenchymal Stem Cells and the Role of Preactivated Mesenchymal Stem Cells Cotransplanted with Allogeneic Islets

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    Régis Linhares Oliveira

    2017-01-01

    Full Text Available Mesenchymal stem cells (MSCs are multipotent cells capable of differentiating into cells from the mesenchymal lineage. The hypoimmunogenic characteristic of MSCs has encouraged studies using allogeneic MSCs for the treatment of autoimmune diseases and inflammatory conditions. Promising preclinical results and the safety of allogeneic MSC transplantation have created the possibility of “off-the-shelf” clinical application of allogeneic cells. This study has aimed to evaluate the survival of untreated and IFN-γ- and TNF-α-treated (preactivated allogeneic MSCs transplanted under the kidney capsule of immunocompetent mice together with the role of preactivated MSCs after cotransplantation with allogeneic islets. The preactivation of MSCs upregulated the gene expression of anti-inflammatory molecules and also enhanced their immunomodulatory capacity in vitro. In vivo, allogeneic MSCs provoked an immunogenic response, with the infiltration of inflammatory cells at the transplant site and full graft rejection in both the untreated and preactivated groups. Allogeneic islets cotransplanted with preactivated MSCs prolonged graft survival for about 6 days, compared with islet alone. The present results corroborate the hypothesis that allogeneic MSCs are not immune-privileged and that after playing their therapeutic role they are rejected. Strategies that reduce allogeneic MSC immunogenicity can potentially prolong their in vivo persistence and improve the therapeutic effects.

  11. A methodology for distinguishing divergent cell fates within a common progenitor population: adenoma- and neuroendocrine-like cells are confounders of rat ileal epithelial cell (IEC-18 culture

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    Paxton Jessica B

    2005-01-01

    Full Text Available Abstract Background IEC-18 cells are a non-transformed, immortal cell line derived from juvenile rat ileal crypt cells. They may have experimental advantages over tumor-derived gastrointestinal lineages, including preservation of phenotype, normal endocrine responses and retention of differentiation potential. However, their proclivity for spontaneous differentiation / transformation may be stereotypical and could represent a more profound experimental confounder than previously realized. We hypothesized that IEC-18 cells spontaneously diverge towards a uniform mixture of epigenetic fates, with corresponding phenotypes, rather than persist as a single progenitor lineage. Results IEC-18 cells were cultured for 72 hours in serum free media (SFM, with and without various insulin-like growth factor agonists to differentially boost the basal rate of proliferation. A strategy was employed to identify constitutive genes as markers of divergent fates through gene array analysis by cross-referencing fold-change trends for individual genes against crypt cell abundance in each treatment. We then confirmed the cell-specific phenotype by immunolocalization of proteins corresponding to those genes. The majority of IEC-18 cells in SFM alone had a loss in expression of the adenomatous polyposis coli (APC gene at the mRNA and protein levels, consistent with adenoma-like transformation. In addition, a small subset of cells expressed the serotonin receptor 2A gene and had neuroendocrine-like morphology. Conclusions IEC-18 cells commonly undergo a change in cell fate prior to reaching confluence. The most common fate switch that we were able to detect correlates with a down regulation of the APC gene and transformation into an adenoma-like phenotype.

  12. Global gene expression profiling of pancreatic islets in mice during streptozotocin-induced β-cell damage and pancreatic Glp-1 gene therapy

    Directory of Open Access Journals (Sweden)

    Jason M. Tonne

    2013-09-01

    Streptozotocin (STZ, a glucosamine-nitrosourea compound, has potent genotoxic effects on pancreatic β-cells and is frequently used to induce diabetes in experimental animals. Glucagon-like peptide-1 (GLP-1 has β-cell protective effects and is known to preserve β-cells from STZ treatment. In this study, we analyzed the mechanisms of STZ-induced diabetes and GLP-1-mediated β-cell protection in STZ-treated mice. At 1 week after multiple low-dose STZ administrations, pancreatic β-cells showed impaired insulin expression, while maintaining expression of nuclear Nkx6.1. This was accompanied by significant upregulation of p53-responsive genes in islets, including a mediator of cell cycle arrest, p21 (also known as Waf1 and Cip1. STZ treatment also suppressed expression of a wide range of genes linked with key β-cell functions or diabetes development, such as G6pc2, Slc2a2 (Glut2, Slc30a8, Neurod1, Ucn3, Gad1, Isl1, Foxa2, Vdr, Pdx1, Fkbp1b and Abcc8, suggesting global β-cell defects in STZ-treated islets. The Tmem229B, Prss53 and Ttc28 genes were highly expressed in untreated islets and strongly suppressed by STZ, suggesting their potential roles in β-cell function. When a pancreas-targeted adeno-associated virus (AAV vector was employed for long-term Glp-1 gene delivery, pancreatic GLP-1 expression protected mice from STZ-induced diabetes through preservation of the β-cell mass. Despite its potent β-cell protective effects, however, pancreatic GLP-1 overexpression showed limited effects on the global gene expression profiles in the islets. Network analysis identified the programmed-cell-death-associated pathways as the most relevant network in Glp-1 gene therapy. Upon pancreatic GLP-1 expression, upregulation of Cxcl13 and Nptx2 was observed in STZ-damaged islets, but not in untreated normal islets. Given the pro-β-cell-survival effects of Cxcl12 (Sdf-1 in inducing GLP-1 production in α-cells, pancreatic GLP-1-mediated Cxcl13 induction might also play a

  13. 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 (pcultures were assayed for TNF-alpha (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 (pculture (pcultures, 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.

  14. The diet-derived short chain fatty acid propionate improves beta-cell function in humans and stimulates insulin secretion from human islets in vitro.

    Science.gov (United States)

    Pingitore, Attilio; Chambers, Edward S; Hill, Thomas; Maldonado, Inmaculada Ruz; Liu, Bo; Bewick, Gavin; Morrison, Douglas J; Preston, Tom; Wallis, Gareth A; Tedford, Catriona; Castañera González, Ramón; Huang, Guo C; Choudhary, Pratik; Frost, Gary; Persaud, Shanta J

    2017-02-01

    Diet-derived short chain fatty acids (SCFAs) improve glucose homeostasis in vivo, but the role of individual SCFAs and their mechanisms of action have not been defined. This study evaluated the effects of increasing colonic delivery of the SCFA propionate on β-cell function in humans and the direct effects of propionate on isolated human islets in vitro. For 24 weeks human subjects ingested an inulin-propionate ester that delivers propionate to the colon. Acute insulin, GLP-1 and non-esterified fatty acid (NEFA) levels were quantified pre- and post-supplementation in response to a mixed meal test. Expression of the SCFA receptor FFAR2 in human islets was determined by western blotting and immunohistochemistry. Dynamic insulin secretion from perifused human islets was quantified by radioimmunoassay and islet apoptosis was determined by quantification of caspase 3/7 activities. Colonic propionate delivery in vivo was associated with improved β-cell function with increased insulin secretion that was independent of changes in GLP-1 levels. Human islet β-cells expressed FFAR2 and propionate potentiated dynamic glucose-stimulated insulin secretion in vitro, an effect that was dependent on signalling via protein kinase C. Propionate also protected human islets from apoptosis induced by the NEFA sodium palmitate and inflammatory cytokines. Our results indicate that propionate has beneficial effects on β-cell function in vivo, and in vitro analyses demonstrated that it has direct effects to potentiate glucose-stimulated insulin release and maintain β-cell mass through inhibition of apoptosis. These observations support ingestion of propiogenic dietary fibres to maintain healthy glucose homeostasis. © 2016 John Wiley & Sons Ltd.

  15. Anterior Gray Matter Pituicytic Heterotopia with Monomorphic Anterior Pituitary Cells: A Variant of Nonsecretory Pituitary Adenoma Neuronal Choristoma? Report of a Rare Case and Review of the Literature.

    Science.gov (United States)

    Yowtak, June; Sharma, Suash; Forseen, Scott E; Alleyne, Cargill H

    2017-01-01

    Mixed tumors of adenomatous and neuronal cells in the sellar region are an uncommon finding. The origins of these heterogeneous tumors are unknown, and management remains unsettled. We report a very rare case of anterior gray matter pituicytic heterotopia with monomorphic anterior pituitary cells that likely represents a variant of nonsecreting pituitary adenoma neuronal choristoma (PANCH) with no ganglion cells. We also review the current literature for the various clinical presentations of PANCH. A 49-year-old female complaining of headache, blurred vision, and hair loss was found to have a nonsecretory sellar mass with compression of the optic chiasm on magnetic resonance imaging (MRI). The mass was excised via a transsphenoidal procedure. Histological analysis of tissue sections revealed heterotopic gray matter with reactive gliosis without ganglion cells or Herring bodies. Only 1 smear exhibited characteristics of a pituitary adenoma. The overall findings were most consistent with a variant of PANCH. At a postoperative follow-up of 4.5 years, there was resolution of visual symptoms, and the residual sellar mass was stable on MRI. Neuronal choristoma is hypothesized to originate from embryonal pituitary or hypothalamus, or by differentiation from pituitary adenoma cells. Surgery is the cornerstone of management, and the clinical course appears to be similar to that of nonfunctioning pituitary adenoma in reported cases. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Increased ectodomain shedding of cell adhesion molecule 1 from pancreatic islets in type 2 diabetic pancreata: correlation with hemoglobin A1c levels.

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    Takao Inoue

    Full Text Available Pulmonary emphysema and type 2 diabetes mellitus (T2DM, both caused by lifestyle factors, frequently concur. Respectively, the diseases affect lung alveolar and pancreatic islet cells, which express cell adhesion molecule 1 (CADM1, an immunoglobulin superfamily member. Protease-mediated ectodomain shedding of full-length CADM1 produces C-terminal fragments (CTFs with proapoptotic activity. In emphysematous lungs, the CADM1 shedding rate and thus the level of CTFs in alveolar cells increase. In this study, CADM1 expression in islet cells was examined by western blotting. Protein was extracted from formalin-fixed, paraffin-embedded sections of pancreata isolated from patients with T2DM (n = 12 or from patients without pancreatic disease (n = 8 at autopsy. After adjusting for the number of islet cells present in the adjacent section, we found that full-length CADM1 decreased in T2DM islets, while ectodomain shedding increased. Hemoglobin A1c levels, measured when patients were alive, correlated inversely with full-length CADM1 levels (P = 0.041 and positively with ectodomain shedding rates (P = 0.001. In immunofluorescence images of T2DM islet cells, CADM1 was detected in the cytoplasm, but not on the cell membrane. Consistently, when MIN6-m9 mouse beta cells were treated with phorbol ester and trypsin to induce shedding, CADM1 immunostaining was diffuse in the cytoplasm. When a form of CTFs was exogenously expressed in MIN6-m9 cells, it localized diffusely in the cytoplasm and increased the number of apoptotic cells. These results suggest that increased CADM1 ectodomain shedding contributes to blood glucose dysregulation in T2DM by decreasing full-length CADM1 and producing CTFs that accumulate in the cytoplasm and promote apoptosis of beta cells. Thus, this study has identified a molecular alteration shared by pulmonary emphysema and T2DM.

  17. Cold inducible RNA binding protein upregulation in pituitary corticotroph adenoma induces corticotroph cell proliferation via Erk signaling pathway

    Science.gov (United States)

    Fu, Wei; Tang, Hao; Chen, Xiao; Zhao, Yao; Zheng, Lili; Pan, Sijian; Wang, Weiqing; Bian, Liuguan; Sun, Qingfang

    2016-01-01

    Cushing's disease is caused by pituitary corticotroph adenoma, and the pathogenesis of it has remained obscure. Here, we showed that cold inducible RNA binding protein (CIRP) was markedly elevated in corticotroph tumors. Forced overexpression of CIRP in murine AtT20 pituitary corticotroph cell line increased corticotroph precursor hormone proopiomelanocortin (POMC) transcription, ACTH secretion and cellular proliferation. In vivo, CIRP overexpression promotes murine corticotroph tumor growth and enhances ACTH production. Mechanistically, we show that CIRP could promote AtT20 cells proliferation by inducing cyclinD1 and decreasing p27 expression via Erk1/2 signaling pathway. Clinically, CIRP overexpression is significantly correlated with Cushing's disease recurrence. CIRP appears to play a critical tumorigenesis function in Cushing's disease and its expression might be a useful biomarker for tumor recurrence. PMID:26824322

  18. Pathological Panorama of Lactating Adenoma

    Directory of Open Access Journals (Sweden)

    Smita Sankaye

    2014-06-01

    Results:Out of the 14 palpable breast masses in lactating women that were diagnosed as lactating adenoma on sonomammography, 05 were found to be tense galactoceles and 09 were found to be lactational adenomas. Panorama of lactational adenomas showed 4 distinct patterns. Pattern A( 04 cases: low columnar epithelium, No necrotic areas or cytoplasmic vacuoles.Pattern B (03 cases: high columnar epithelium with cytoplasmic vacuoles. No necrotic areas. Pattern C (1 case: prominent lactiferous ductules with areas of necrosis and infarct. Pattern D (1 case: cytoplasmic vacuoles, and islands of ductal cells in a background of prominent foamy material. This internal nature of lesions on FNAC was not identifiable by clinical palpation alone. None of the lesions labelled as lactating adenomas on sonomammography showed any signs of malignancy on FNAC. Conclusions:FNAC is a useful method for confirming that a palpable breast lump in a lactating lady is lactating adenoma indeed. Four different patterns of microscopic appearances of lactational adenoma were noted in this study. [Cukurova Med J 2014; 39(3.000: 464-469

  19. Analysis of islet beta cell functions and their correlations with liver dysfunction in patients with neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD).

    Science.gov (United States)

    Lu, Chun-Ting; Yang, Jing; Huang, Si-Min; Feng, Lie; Li, Ze-Jian

    2017-11-01

    Neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD) primarily manifests in neonates or infants with hepatomegaly, liver dysfunction, and hypoglycemia. This study investigated the functions of islet beta cells and their correlations with liver dysfunction in NICCD patients.We retrospectively analyzed clinical data on liver function and islet beta cell functions for 36 patients diagnosed with NICCD and 50 subjects as the control group. The NICCD group had significantly higher total bilirubin (TBIL), direct bilirubin (DBIL), alanine aminotransferase (ALT), aspartate amino transferase (AST), gamma-glutamyl transpeptidase (GGT), alkaline phosphatase (ALP) and alpha-fetoprotein (AFP) levels and albumin/globulin ratio (A/G) (P insulin, C-peptide (C-P), the homeostasis model of assessment for the insulin resistance index (HOMA-IR), fasting beta cell function (FBCI), and the HOMA beta cell function index (HBCI) between the NICCD and control groups were not significant (P > .05). A linear correlation was found between FBG and fasting insulin (P insulin (P = .023), HOMA-IR (P = .023), FBCI (P = .049), and HBCI (P = .048) were positively correlated with increases in the ALT level. There was no difference in islet beta cell functions between the NICCD and control groups. The liver dysfunction may be correlated with islet beta cell functions in NICCD patients.

  20. 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.

  1. Real architecture For 3D Tissue (RAFT™) culture system improves viability and maintains insulin and glucagon production of mouse pancreatic islet cells.

    Science.gov (United States)

    Szebeni, Gabor J; Tancos, Zsuzsanna; Feher, Liliana Z; Alfoldi, Robert; Kobolak, Julianna; Dinnyes, Andras; Puskas, Laszlo G

    2017-04-01

    There is an unmet medical need for the improvement of pancreatic islet maintenance in culture. Due to restricted donor availability it is essential to ameliorate islet viability and graft engraftment. The aim of this study was to compare the standard tissue culture techniques with the advanced Real Architecture For 3D Tissue (RAFT™) culture system in terms of viability and hormone production. Here, we first report that islets embedded in RAFT™ collagen type I advanced tissue culture system maintain their tissue integrity better than in monolayer and suspension cultures. The Calcein violet assay and Annexin V/propidium-iodide staining show higher cell viability in the RAFT™ culture system. Quantitative real-time PCR data showed that RAFT™ increases insulin expression after 18 days in culture compared to traditional methods. Enhanced insulin and glucagon production was further verified by immunofluorescent staining in a time-course manner. These results indicate that RAFT™ tissue culture platform can be a promising tool to maintain pancreatic islet spheroid integrity and culture islets for downstream high throughput pharmacological studies ex vivo.

  2. 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...

  3. Improving Islet Engraftment by Gene Therapy

    Directory of Open Access Journals (Sweden)

    Xiaojie Wang

    2011-01-01

    Full Text Available Islet cell transplantation is currently the only feasible long-term treatment option for patients with type 1 diabetes. However, the majority of transplanted islets experience damage and apoptosis during the isolation process, a blood-mediated inflammatory microenvironment in the portal vein upon islet infusion, hypoxia induced by the low oxygenated milieu, and poor-revascularization-mediated lack of nutrients, and impaired hormone modulation in the local transplanted site. Strategies using genetic modification methods through overexpression or silencing of those proteins involved in promoting new formation of blood vessels or inhibition of apoptosis may overcome these hurdles and improve islet engraftment outcomes.

  4. The dissociation of tumor-induced weight loss from hypoglycemia in a transplantable pluripotent rat islet tumor results in the segregation of stable alpha- and beta-cell tumor phenotypes

    DEFF Research Database (Denmark)

    Madsen, O D; Karlsen, C; Nielsen, E

    1993-01-01

    We previously established pluripotent transformed rat islet cell lines, MSL-cells, of which certain clones have been used to study processes of islet beta-cell maturation, including the transcriptional activation of the insulin gene induced by in vivo passage. Thus, successive sc transplantation...... a common clonal origin of pluripotent MSL cells, thus supporting the existence of a cell lineage relationship between islet alpha- and beta-cell during ontogeny; and 2) that our glucagonomas release an anorexigenic substance(s) of unknown nature that causes a severe weight loss comparable to that reported...... necrosis factor (cachectin) was not produced by any of the tumors. Proglucagon was processed as in the fetal islet to products representative of both pancreatic alpha-cell and intestinal L-cell phenotypes, with glucagon and Glp-1 (7-36)amide as the major extractable products. In contrast...

  5. Celecoxib and tauro-ursodeoxycholic acid co-treatment inhibits cell growth in familial adenomatous polyposis derived LT97 colon adenoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Heumen, Bjorn W.H. van, E-mail: b.vanheumen@mdl.umcn.nl [Department of Gastroenterology and Hepatology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Roelofs, Hennie M.J.; Morsche, Rene H.M. te [Department of Gastroenterology and Hepatology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Marian, Brigitte [Institute of Cancer Research, Wien University, Vienna (Austria); Nagengast, Fokko M.; Peters, Wilbert H.M. [Department of Gastroenterology and Hepatology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands)

    2012-04-15

    Chemoprevention would be a desirable strategy to avoid duodenectomy in patients with familial adenomatous polyposis (FAP) suffering from duodenal adenomatosis. We investigated the in vitro effects on cell proliferation, apoptosis, and COX-2 expression of the potential chemopreventives celecoxib and tauro-ursodeoxycholic acid (UDCA). HT-29 colon cancer cells and LT97 colorectal micro-adenoma cells derived from a patient with FAP, were exposed to low dose celecoxib and UDCA alone or in combination with tauro-cholic acid (CA) and tauro-chenodeoxycholic acid (CDCA), mimicking bile of FAP patients treated with UDCA. In HT-29 cells, co-treatment with low dose celecoxib and UDCA resulted in a decreased cell growth (14-17%, p < 0.01). A more pronounced decrease (23-27%, p < 0.01) was observed in LT97 cells. Cell growth of HT-29 cells exposed to 'artificial bile' enriched with UDCA, was decreased (p < 0.001), either in the absence or presence of celecoxib. In LT97 cells incubated with 'artificial bile' enriched with UDCA, cell growth was decreased only in the presence of celecoxib (p < 0.05). No clear evidence was found for involvement of proliferating cell nuclear antigen, caspase-3, or COX-2 in the cellular processes leading to the observed changes in cell growth. In conclusion, co-treatment with low dose celecoxib and UDCA has growth inhibitory effects on colorectal adenoma cells derived from a patient with FAP, and further research on this combination as promising chemopreventive strategy is desired. -- Highlights: Black-Right-Pointing-Pointer Celecoxib and UDCA acid co-treatment decreases cell growth in colon tumor cells. Black-Right-Pointing-Pointer UDCA enriched 'artificial bile' decreases LT-97 cell growth only in presence of celecoxib. Black-Right-Pointing-Pointer PCNA, caspase-3, nor COX-2 seem to be involved in the observed changes in cell growth.

  6. Null cell adenomas of the pituitary gland: an institutional review of their clinical imaging and behavioral characteristics.

    Science.gov (United States)

    Balogun, James A; Monsalves, Eric; Juraschka, Kyle; Parvez, Kashif; Kucharczyk, Walter; Mete, Ozgur; Gentili, Fred; Zadeh, Gelareh

    2015-03-01

    The aim of the study was to establish if the null cell adenoma (NCA) forms a distinct subgroup with unique clinicopathological characteristics within the nonfunctioning pituitary adenoma group particularly in relation to the silent gonadotroph adenomas (SGAs). We identified 31 patients with the pathological diagnosis of NCA verified by routine histology and immunohistochemistry with distinct differentiation from SGAs by an established negative testing for SF-1 at the Toronto Western Hospital between December 2004 and August 2010. We reviewed their demographic data, clinical features, magnetic resonance imaging, and the histologic variables: MIB-1, FGFR4, and P27. We compared these to 63 SGAs identified within the same period. All the NCAs were macroadenomas with diameter ranging from 15-57 mm and tumor volumes between 1.95-53.5 mm(3). Preoperative cavernous sinus tumor growth was able to predict the presence of a residual after surgery (p = 0.023). Furthermore, preoperative cavernous sinus extension (p = 0.002) and negative P27 expression (p = 0.035) were able to independently predict the subsequent growth of the postoperative tumor residual. Comparing the NCA to SGA, we found that MIB-1 was higher in NCA (mean ± SD = 3.43 ± 2.76 %) compared to SGAs (mean ± SD = 2.49 ± 1.41 %) (p = 0.044). The preoperative and postoperative tumor volume doubling times (TVDTs) displayed a negative correlation in the SGA (r = -0.855, p = 0.002) while in the NCA, a positive correlation was evident (r = 0.718, p = 0.029). Our study suggests that the NCAs are a distinct group with differing behavioral characteristics from the SGAs. It also appears that the finding of cavernous sinus extension on preoperative imaging and a negative P27 expression on immunohistochemistry in NCAs may be valuable tools in predicting residual tumor growth which may impact on postoperative care.

  7. 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.

  8. Effects of fluid dynamic stress on fracturing of cell-aggregated tissue during purification for islets of Langerhans transplantation

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    Shintaku, H; Kawano, S [Department of Mechanical Science and Bioengineering, Graduate School of Engineering Science, Osaka University, Machikaneyama-cho, Toyonaka, Osaka 560-8531 (Japan); Okitsu, T [Transplantation Unit, Kyoto University Hospital, Kawara-cho Shogoin, Sakyo-ku, Kyoto 606-8507 (Japan); Matsumoto, S [Baylor Research Institute Islet Cell Laboratory, 1400 Eight Avenue, Fort Worth, TX 76104 (United States); Suzuki, T; Kanno, I; Kotera, H [Department of Microengineering, Kyoto University, Yoshida-Honmachi, Sakyo-ku, Kyoto 606-8501 (Japan)], E-mail: shintaku@me.es.osaka-u.ac.jp

    2008-06-07

    Among clinical treatments for type 1 diabetes mellitus, the transplantation of islets of Langerhans to the portal vein of the hepar is a commonly used treatment for glucose homeostasis. Islet purification using the density gradient of a solution in a centrifuge separator is required for safety and efficiency. In the purification, the number of tissues to be transplanted is reduced by removing the acinar tissue and gathering the islet from the digest of pancreas. However, the mechanical effects on the fracture of islets in the centrifuge due to fluid dynamic stress are a serious problem in the purification process. In this study, a preliminary experiment using a cylindrical rotating viscometer with a simple geometry is conducted in order to systematically clarify the effect of fluid dynamic stress on the fracture of islets. The effects of fluid dynamic stress on the islet configuration is quantitatively measured for various flow conditions, and a predictive fracture model is developed based on the experimental results. Furthermore, in the practical purification process in the COBE (Gambro BCT), which is widely used in clinical applications, we perform a numerical analysis of the fluid dynamic stress based on Navier-Stokes equations to estimate the stress conditions for islets. Using the fracture model and numerical analysis, the islet fracture characteristics using the COBE are successfully investigated. The results obtained in this study provide crucial information for the purification of islets by centrifuge in practical and clinical applications.

  9. Prevalence and features of pancreatic islet cell autoimmunity in women with gestational diabetes from different ethnic groups.

    Science.gov (United States)

    Kousta, E; Lawrence, N J; Anyaoku, V; Johnston, D G; McCarthy, M I

    2001-07-01

    To assess the prevalence and characteristics of islet cell autoimmunity amongst women with gestational diabetes selected from South Asian and Afro-Caribbean as well as European populations. Cross-sectional retrospective survey of subject cohort. Three hundred and twenty-one women with a recent history of gestational diabetes (173 European, 86 South Asian and 62 Afro-Caribbean), a median (range) of 22 (1-150) months postpartum. Antibodies to Glutamic acid decarboxylase were found in 13 (4%) of these women. There was no difference in the prevalence of anti-glutamic acid decarboxylase positivity between the three ethnic groups (European 4.6%, South Asian 3.5%, Afro-Caribbean 3.2%). Anti-glutamic acid decarboxylase positive women were leaner than anti-glutamic acid decarboxylase negative women (body mass index, median (upper-lower quartile) 23.9 (22.5-26.7) vs 26.6 (23.4-30.5)kg/m2, P = 0.03, P = 0.049 allowing for ethnicity). There was no difference between glutamic acid decarboxylase-positive and glutamic acid decarboxylase-negative women for age, family history of diabetes, waist/hip ratio, prevalence of insulin treatment during pregnancy, postpartum glucose status, lipid profile and indices of insulin action and beta-cell function. Markers of islet cell autoimmunity are found as frequently in gestational diabetes women of South Asian and Afro-Caribbean origin, as they are in European subjects. Identification of future risk of type 1 diabetes is relevant to the planning of clinical management and intervention strategies in women with gestational diabetes of all major ethnic groups.

  10. Lixisenatide accelerates restoration of normoglycemia and improves human beta-cell function and survival in diabetic immunodeficient NOD-scid IL-2rg(null) RIP-DTR mice engrafted with human islets.

    Science.gov (United States)

    Yang, Chaoxing; Loehn, Matthias; Jurczyk, Agata; Przewozniak, Natalia; Leehy, Linda; Herrera, Pedro L; Shultz, Leonard D; Greiner, Dale L; Harlan, David M; Bortell, Rita

    2015-01-01

    Glucagon-like peptide-1 induces glucose-dependent insulin secretion and, in rodents, increases proliferation and survival of pancreatic beta cells. To investigate the effects on human beta cells, we used immunodeficient mice transplanted with human islets. The goal was to determine whether lixisenatide, a glucagon-like peptide-1 receptor agonist, improves human islet function and survival in vivo. Five independent transplant studies were conducted with human islets from five individual donors. Diabetic human islet-engrafted immunodeficient mice were treated with lixisenatide (50, 150, and 500 µg/kg) or vehicle. Islet function was determined by blood glucose, plasma human insulin/C-peptide, and glucose tolerance tests. Grafts were analyzed for total beta- and alpha-cell number, percent proliferation, and levels of apoptosis. Diabetic mice transplanted with marginal human islet mass and treated with lixisenatide were restored to euglycemia more rapidly than vehicle-treated mice. Glucose tolerance tests, human plasma insulin, and glucose-stimulation indices of lixisenatide-treated mice were significantly improved compared to vehicle-treated mice. The percentages of proliferating or apoptotic beta cells at graft recovery were not different between lixisenatide-treated and vehicle-treated mice. Nevertheless, in one experiment we found a significant twofold to threefold increase in human beta-cell numbers in lixisenatide-treated compared to vehicle-treated mice. Diabetic human islet-engrafted immunodeficient mice treated with lixisenatide show improved restoration of normoglycemia, human plasma insulin, and glucose tolerance compared to vehicle-treated mice engrafted with the same donor islets. Because the proliferative capacity of human beta cells is limited, improved beta-cell survival coupled with enhanced beta-cell function following lixisenatide treatment may provide the greatest benefit for diabetic patients with reduced functional islet mass.

  11. 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.

  12. Increase in postoperative insulin requirements does not lead to decreased quality of life after total pancreatectomy with islet cell autotransplantation for chronic pancreatitis.

    Science.gov (United States)

    Dorlon, Margaret; Owczarski, Stephanie; Wang, Hongjun; Adams, David; Morgan, Katherine

    2013-07-01

    Previous studies have shown that total pancreatectomy with islet cell autotransplantation improves quality of life in chronic pancreatitis. A significant number of these patients develop postoperative hyperglycemia and daily insulin requirements or increase in daily insulin requirements. Our study investigates whether increased insulin requirements postoperatively have a negative impact on quality of life. A prospectively collected database of 74 patients undergoing extensive pancreatectomy with islet autotransplantation for pancreatitis was reviewed. Data pertaining to daily requirements and quality of life (QOL), as measured by the SF-12 questionnaire, in the preoperative and postoperative period were reviewed. Approval from the Institutional Review Board for the evaluation of human subjects was obtained. Seventy-four patients underwent extensive pancreatectomy with islet autotransplantation for pancreatitis. The majority of these patients required new daily insulin or an increase in daily insulin requirements postoperatively. Mean preoperative HA1c in this group was 5.6 with an increase to 7.3 at 6 months postoperatively (P Total pancreatectomy with islet cell autotransplantation is an effective surgery for end-stage chronic pancreatitis. Quality of life significantly improves in physical and mental health components regardless of a postoperative increase in daily insulin requirements.

  13. Palmitate-induced lipotoxicity alters acetylation of multiple proteins in clonal β cells and human pancreatic islets.

    Science.gov (United States)

    Ciregia, Federica; Bugliani, Marco; Ronci, Maurizio; Giusti, Laura; Boldrini, Claudia; Mazzoni, Maria R; Mossuto, Sandra; Grano, Francesca; Cnop, Miriam; Marselli, Lorella; Giannaccini, Gino; Urbani, Andrea; Lucacchini, Antonio; Marchetti, Piero

    2017-10-18

    Type 2 diabetes is characterized by progressive β cell dysfunction, with lipotoxicity playing a possible pathogenetic role. Palmitate is often used to examine the direct effects of lipotoxicity and it may cause mitochondrial alterations by activating protein acetylation. However, it is unknown whether palmitate influences protein acetylation in β cells. We investigated lysine acetylation in mitochondrial proteins from INS-1E β cells (INS-1E) and in proteins from human pancreatic islets (HPI) after 24 h palmitate exposure. First, we confirmed that palmitate damages β cells and demonstrated that chemical inhibition of deacetylation also impairs INS-1E function and survival. Then, by 2-D gel electrophoresis, Western Blot and Liquid Chromatography-Mass Spectrometry we evaluated the effects of palmitate on protein acetylation. In mitochondrial preparations from palmitate-treated INS-1E, 32 acetylated spots were detected, with 13 proteins resulting over-acetylated. In HPI, 136 acetylated proteins were found, of which 11 were over-acetylated upon culture with palmitate. Interestingly, three proteins, glutamate dehydrogenase, mitochondrial superoxide dismutase, and SREBP-1, were over-acetylated in both INS-1E and HPI. Therefore, prolonged exposure to palmitate induces changes in β cell protein lysine acetylation and this modification could play a role in causing β cell damage. Dysregulated acetylation may be a target to counteract palmitate-induced β cell lipotoxicity.

  14. Abnormal anxiety- and depression-like behaviors in mice lacking both central serotonergic neurons and pancreatic islet cells

    Directory of Open Access Journals (Sweden)

    Yun-Fang eJia

    2014-09-01

    Full Text Available Dysfunction of central serotonin (5-HT system has been proposed to be one of the underlying mechanisms for anxiety and depression, and the association of diabetes mellitus and psychiatric disorders has been noticed by the high prevalence of anxiety/depression in patients with diabetes mellitus. This promoted us to examine these behaviors in central 5-HT-deficient mice and those also suffering with diabetes mellitus. Mice lacking either 5-HT or central serotonergic neurons were generated by conditional deletion of Tph2 or Lmx1b respectively. Simultaneous depletion of both central serotonergic neurons and pancreatic islet cells was achieved by administration of diphtheria toxin (DT in Pet1-Cre;Rosa26-DT receptor (DTR mice. The central 5-HT-deficient mice showed reduced anxiety-like behaviors as they spent more time in and entered more often into the light box in the light/dark box test compared with controls; similar results were observed in the elevated plus maze test. However, they displayed no differences in the immobility time of the forced swimming and tail suspension tests suggesting normal depression-like behaviors in central 5-HT-deficient mice. As expected, DT-treated Pet1-Cre;Rosa26-DTR mice lacking both central serotonergic neurons and pancreatic islet endocrine cells exhibited several classic diabetic symptoms. Interestingly, they displayed increased anxiety-like behaviors but reduced immobility time in the forced swimming and tail suspension tests. Furthermore, the hippocampal neurogenesis was dramatically enhanced in these mice. These results suggest that the deficiency of central 5-HT may not be sufficient to induce anxiety/depression-like behaviors in mice, and the enhanced hippocampal neurogenesis may contribute to the altered depression-like behaviors in the 5-HT-deficient mice with diabetes. Our current investigation provides a novel insight into understanding the relationship between diabetes mellitus and psychiatric disorders.

  15. Total pancreatectomy with islet cell transplantation vs intrathecal narcotic pump infusion for pain control in chronic pancreatitis.

    Science.gov (United States)

    Mokadem, Mohamad; Noureddine, Lama; Howard, Thomas; McHenry, Lee; Sherman, Stuart; Fogel, Evan L; Watkins, James L; Lehman, Glen A

    2016-04-28

    To evaluate pain control in chronic pancreatitis patients who underwent total pancreatectomy with islet cell transplantation or intrathecal narcotic pump infusion. We recognized 13 patients who underwent intrathecal narcotic pump (ITNP) infusion and 57 patients who underwent total pancreatectomy with autologous islet cell transplantation (TP + ICT) for chronic pancreatitis (CP) pain control between 1998 and 2008 at Indiana University Hospital. All patients had already failed multiple other modalities for pain control and the decision to proceed with either intervention was made at the discretion of the patients and their treating physicians. All patients were evaluated retrospectively using a questionnaire inquiring about their pain control (using a 0-10 pain scale), daily narcotic dose usage, and hospital admission days for pain control before each intervention and during their last follow-up. All 13 ITNP patients and 30 available TP + ICT patients were evaluated. The mean age was approximately 40 years in both groups. The median duration of pain before intervention was 6 years and 7 years in the ITNP and TP + ICT groups, respectively. The median pain score dropped from 8 to 2.5 (on a scale of 0-10) in both groups on their last follow up. The median daily dose of narcotics also decreased from 393 mg equivalent of morphine sulfate to 8 mg in the ITNP group and from 300 mg to 40 mg in the TP + ICT group. No patient had diabetes mellitus (DM) before either procedure whereas 85% of those who underwent pancreatectomy were insulin dependent on their last evaluation despite ICT. ITNP and TP + ICT are comparable for pain control in patients with CP however with high incidence of DM among those who underwent TP + ICT. Prospective comparative studies and longer follow up are needed to better define treatment outcomes.

  16. Long-term in-vitro treatment of human growth hormone (GH)-secreting pituitary adenoma cells with octreotide causes accumulation of intracellular GH and GH mRNA levels.

    Science.gov (United States)

    Hofland, L J; Velkeniers, B; vd Lely, A J; van Koetsveld, P M; Kazemzadeh, M; Waaijers, M; Hooghe-Peters, E L; Lamberts, S W

    1992-09-01

    We studied the effects of long-term in-vitro exposure of human GH secreting pituitary adenoma cells to octreotide on GH release, intracellular GH concentrations and GH messenger ribonucleic acid (mRNA) levels. Human GH-secreting pituitary adenoma cells were cultured for periods from 4 days up to 3 weeks without or with octreotide (10 nM) and/or bromocriptine (10 nM). The effects of these drugs were measured on GH release, intracellular GH concentrations and intracellular GH mRNA levels. Thirteen patients with GH-secreting pituitary adenomas were studied. Twelve patients were untreated, one had been pretreated with octreotide (12 weeks, 3 x 100 micrograms daily). GH, PRL, alpha-subunit and IGF-I concentrations in plasma, media and cell extracts were determined by immunoradiometric or radioimmuno-assays. GH mRNA levels were determined by automatic quantification of grain numbers in individual adenoma cells. Incubation of the adenoma cells for 4 days with 10 nM octreotide induced a dose-dependent inhibition of GH release and a parallel increase (increase varying between 124 and 617% of control) in the intracellular GH levels was observed in six of seven adenomas. In addition, bromocriptine, when effective in inhibiting GH release by the adenomas, also induced an increase in intracellular GH levels. Even after 3 weeks of exposure to 10 nM octreotide in vitro there was a statistically significant increase in intracellular GH levels (between 191 and 923% of control). Withdrawal of octreotide after 6 days of incubation resulted in a lowering of intracellular GH levels to control values, showing that the octreotide-induced increase in intracellular GH is reversible. In a 96-hour incubation with 10 nM octreotide, GH mRNA levels were increased in two, and slightly decreased in one of the three adenomas tested. This effect was time dependent in that there was no significant effect of 10 nM octreotide on GH mRNA levels in a 24-hour incubation. (1) Long-term in-vitro exposure

  17. Relation of red blood cell\\\\\\'s folate and methylenetetrahedrofolate reductase C677T polymorphism to colorectal adenoma

    Directory of Open Access Journals (Sweden)

    Zohreh Mazloom

    2014-11-01

    Methods: In a case-control study conducted from January to October 2007 in Endoscopy-Colonoscopy ward of Shahid Faghihi Hospital, Shiraz. Participants were 177 case of colorectal adenoma who had pathologic-confirmed adenomatous polyps in full colonoscopy examination and 366 controls without polyps in full colonoscopy. Fasting venous blood were drawn from patients in order to determine RBC’s folate and to identify the MTHFR polymorphism by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP technique. Results: Gender Distribution in the patient group were 57.6% male and 42.3% female and control group consisted of 55.1% male and 43.9% female. 50.2% of cases and 49.2% of controls were in the age group “45 years and above”. The T allele frequency was 56.6% in control group and 34.4% in colorectal adenoma patients. There was a significant association between T allele in -677 position of MTHFR gene and colorectal adenoma susceptibility (OR: 1.85, 95% CI: 0.76-4.24, P0.05 but mean concentration of RBC’s folate was the lowest in TT genotype compare with two other genotype. Odd's Ratio for low (<140ng/ml versus high level of RBC’s folate in participants with TT genotype was (OR: 2.08, 95% CI: 0.10-2.19, P<0.05 as compare with the CC ones. Conclusion: The result of this study suggested an inverse association between RBC's folate concentration and colorectal adenomas risk, which may be more relevant for those with the MTHFR TT genotype.

  18. Maternal microchimerism: increased in the insulin positive compartment of type 1 diabetes pancreas but not in infiltrating immune cells or replicating islet cells.

    Directory of Open Access Journals (Sweden)

    Jody Ye

    Full Text Available Maternal microchimeric cells (MMc transfer across the placenta during pregnancy. Increased levels of MMc have been observed in several autoimmune diseases including type 1 diabetes but their role is unknown. It has been suggested that MMc are 1 effector cells of the immune response, 2 targets of the autoimmune response or 3 play a role in tissue repair. The aim of this study was to define the cellular phenotype of MMc in control (n = 14 and type 1 diabetes pancreas (n = 8.Using sex chromosome-based fluorescence in-situ hybridization, MMc were identified in male pancreas and their phenotype determined by concomitant immunofluorescence.In normal pancreas, MMc positive for endocrine, exocrine, duct and acinar markers were identified suggesting that these cells are derived from maternal progenitors. Increased frequencies of MMc were observed in type 1 diabetes pancreas (p = 0.03 with particular enrichment in the insulin positive fraction (p = 0.01. MMc did not contribute to infiltrating immune cells or Ki67+ islet cell populations in type 1 diabetes.These studies provide support for the hypothesis that MMc in human pancreas are derived from pancreatic precursors. Increased frequencies of MMc beta cells may contribute to the initiation of autoimmunity or to tissue repair but do not infiltrate islets in type 1 diabetes.

  19. Dielectric spectroscopy for monitoring human pancreatic islet differentiation within cell-seeded scaffolds in a perfusion bioreactor system.

    Science.gov (United States)

    Daoud, J; Heileman, K; Shapka, S; Rosenberg, L; Tabrizian, M

    2015-09-21

    The long-term in vitro culture and differentiation of human pancreatic islets is still hindered by the inability to emulate a suitable microenvironment mimicking physiological extracellular matrix (ECM) support and nutrient/oxygen perfusion. This is further amplified by the current lack of a non-invasive and rapid monitoring system to readily evaluate cellular processes. In this study, we realized a viable method for non-invasively monitoring isolated human pancreatic islets in vitro. Islets are induced to dedifferentiate into proliferative duct-like structures (DLS) in preparation for potential and subsequent re-differentiation into functional islet-like structures (ILS) in a process reminiscent of islet regeneration strategies. This long-term in vitro process is conducted within a three-dimensional microenvironment involving islets embedded in an optimized ECM gel supported by microfabricated three-dimensional scaffolds. The islet-scaffold is then housed and continuously perfused within chambers of a bioreactor platform. The process in its entirety is monitored through dielectric spectroscopy measurements, yielding an accurate representation of cellular morphology, functionality, and volume fraction. This non-invasive and real-time monitoring tool can be further manipulated to elucidate important information about the optimized cellular microenvironment required for maintaining long-term culture and achieve efficient differentiation for islet regeneration.

  20. Gestational Diabetes Mellitus From Inactivation of Prolactin Receptor and MafB in Islet β-Cells.

    Science.gov (United States)

    Banerjee, Ronadip R; Cyphert, Holly A; Walker, Emily M; Chakravarthy, Harini; Peiris, Heshan; Gu, Xueying; Liu, Yinghua; Conrad, Elizabeth; Goodrich, Lisa; Stein, Roland W; Kim, Seung K

    2016-08-01

    β-Cell proliferation and expansion during pregnancy are crucial for maintaining euglycemia in response to increased metabolic demands placed on the mother. Prolactin and placental lactogen signal through the prolactin receptor (PRLR) and contribute to adaptive β-cell responses in pregnancy; however, the in vivo requirement for PRLR signaling specifically in maternal β-cell adaptations remains unknown. We generated a floxed allele of Prlr, allowing conditional loss of PRLR in β-cells. In this study, we show that loss of PRLR signaling in β-cells results in gestational diabetes mellitus (GDM), reduced β-cell proliferation, and failure to expand β-cell mass during pregnancy. Targeted PRLR loss in maternal β-cells in vivo impaired expression of the transcription factor Foxm1, both G1/S and G2/M cyclins, tryptophan hydroxylase 1 (Tph1), and islet serotonin production, for which synthesis requires Tph1. This conditional system also revealed that PRLR signaling is required for the transient gestational expression of the transcription factor MafB within a subset of β-cells during pregnancy. MafB deletion in maternal β-cells also produced GDM, with inadequate β-cell expansion accompanied by failure to induce PRLR-dependent target genes regulating β-cell proliferation. These results unveil molecular roles for PRLR signaling in orchestrating the physiologic expansion of maternal β-cells during pregnancy. © 2016 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

  1. Islet cell research brings hope for a diabetes cure: meeting report from the 6(th) annual islet society meeting in Stellenbosch, South Africa.

    Science.gov (United States)

    Tchokonte-Nana, V; Cockburn, I L; Manda, J K; Kotze, P C; Johnson, J D

    2014-01-01

    The International Diabetes Federation predicts that, over the next twenty years, the largest increase in the prevalence of diabetes will be in the Africa region. Recognizing an unmet need for more focus on Africa and engagement with African scholars, the Islet Society held its 6th annual meeting July 20-21, 2014 in Stellenbosch, South Africa. Here, we present a report that covers the presentations and discussion points from that meeting. Work was presented on a variety of topics and included presentations by a significant proportion of Africa diabetes researchers. Overall, it was an excellent conference, with many new international collaborations initiated. We hope that other groups will also respond to the need for more conferences in Africa and focused on Africa.

  2. Contrasting Roles of Islet Resident Immunoregulatory Macrophages and Dendritic Cells in Experimental Autoimmune Type 1 Diabetes.

    Directory of Open Access Journals (Sweden)

    Thomas B Thornley

    Full Text Available The innate immune system critically shapes diabetogenic adaptive immunity during type 1 diabetes (T1D pathogenesis. While the role of tissue-infiltrating monocyte-derived macrophages in T1D is well established, the role of their tissue-resident counterparts remains undefined. We now demonstrate that islet resident macrophages (IRMs from non-autoimmune mice have an immunoregulatory phenotype and powerfully induce FoxP3+ Tregs in vitro. The immunoregulatory phenotype and function of IRMs is compromised by TLR4 activation in vitro. Moreover, as T1D approaches in NOD mice, the immunoregulatory phenotype of IRMs is diminished as is their relative abundance compared to immunostimulatory DCs. Our findings suggest that maintenance of IRM abundance and their immunoregulatory phenotype may constitute a novel therapeutic strategy to prevent and/or cure T1D.

  3. Reversal of type 1 diabetes via islet β cell regeneration following immune modulation by cord blood-derived multipotent stem cells

    Directory of Open Access Journals (Sweden)

    Zhao Yong

    2012-01-01

    Full Text Available Abstract Background Inability to control autoimmunity is the primary barrier to developing a cure for type 1 diabetes (T1D. Evidence that human cord blood-derived multipotent stem cells (CB-SCs can control autoimmune responses by altering regulatory T cells (Tregs and human islet β cell-specific T cell clones offers promise for a new approach to overcome the autoimmunity underlying T1D. Methods We developed a procedure for Stem Cell Educator therapy in which a patient's blood is circulated through a closed-loop system that separates lymphocytes from the whole blood and briefly co-cultures them with adherent CB-SCs before returning them to the patient's circulation. In an open-label, phase1/phase 2 study, patients (n = 15 with T1D received one treatment with the Stem Cell Educator. Median age was 29 years (range: 15 to 41, and median diabetic history was 8 years (range: 1 to 21. Results Stem Cell Educator therapy was well tolerated in all participants with minimal pain from two venipunctures and no adverse events. Stem Cell Educator therapy can markedly improve C-peptide levels, reduce the median glycated hemoglobin A1C (HbA1C values, and decrease the median daily dose of insulin in patients with some residual β cell function (n = 6 and patients with no residual pancreatic islet β cell function (n = 6. Treatment also produced an increase in basal and glucose-stimulated C-peptide levels through 40 weeks. However, participants in the Control Group (n = 3 did not exhibit significant change at any follow-up. Individuals who received Stem Cell Educator therapy exhibited increased expression of co-stimulating molecules (specifically, CD28 and ICOS, increases in the number of CD4+CD25+Foxp3+ Tregs, and restoration of Th1/Th2/Th3 cytokine balance. Conclusions Stem Cell Educator therapy is safe, and in individuals with moderate or severe T1D, a single treatment produces lasting improvement in metabolic control. Initial results indicate Stem Cell

  4. Increased secretion of insulin and proliferation of islet {beta}-cells in rats with mesenteric lymph duct ligation

    Energy Technology Data Exchange (ETDEWEB)

    Nagino, Ko; Yokozawa, Junji; Sasaki, Yu; Matsuda, Akiko; Takeda, Hiroaki [Department of Gastroenterology, Faculty of Medicine, Yamagata University, Yamagata 990-9585 (Japan); Kawata, Sumio, E-mail: Sumio_Kawata@pref.hyogo.lg.jp [Department of Gastroenterology, Faculty of Medicine, Yamagata University, Yamagata 990-9585 (Japan); Hyogo Prefectural Nishinomiya Hospital, 13-9 Rokutanji-cho, Nishinomiya 662-0918 (Japan)

    2012-08-24

    Highlights: Black-Right-Pointing-Pointer Insulin secretion was increased during the OGTT or IVGTT in mesenteric lymph duct-ligated rats. Black-Right-Pointing-Pointer Proliferation of islet {beta}-cells was upregulated in lymph duct-ligated rats. Black-Right-Pointing-Pointer Mesenteric lymph duct flow has a role in glucose metabolism. -- Abstract: Background and aims: It has been suggested that intestinal lymph flow plays an important role in insulin secretion and glucose metabolism after meals. In this study, we investigated the influence of ligation of the mesenteric lymph duct on glucose metabolism and islet {beta}-cells in rats. Methods: Male Sprague-Dawley rats (10 weeks old) were divided into two groups: one underwent ligation of the mesenteric lymph duct above the cistern (ligation group), and the other underwent a sham operation (sham group). After 1 and 2 weeks, fasting plasma concentrations of glucose, insulin, triglyceride, glucose-dependent insulinotropic polypeptide (GIP), and the active form of glucagon-like peptide-1 (GLP-1) were measured. At 2 weeks after the operation, the oral glucose tolerance test (OGTT) and intravenous glucose tolerance test (IVGTT) were performed. After the rats had been sacrificed, the insulin content of the pancreas was measured and the proliferation of {beta}-cells was assessed immunohistochemically using antibodies against insulin and Ki-67. Results: During the OGTT, the ligation group showed a significant decrease in the plasma glucose concentration at 120 min (p < 0.05) and a significant increase in the plasma insulin concentration by more than 2-fold at 15 min (p < 0.01). On the other hand, the plasma GIP concentration was significantly decreased at 60 min (p < 0.01) in the ligated group, while the active form of GLP-1 showed a significantly higher level at 90 min (1.7-fold; p < 0.05) and 120 min (2.5-fold; p < 0.01). During the IVGTT, the plasma insulin concentration in the ligation group was significantly higher at 2

  5. Glucagon-Like Peptide-1 Protects Human Islets against Cytokine-Mediated β-Cell Dysfunction and Death: A Proteomic Study of the Pathways Involved

    DEFF Research Database (Denmark)

    Rondas, Dieter; Bugliani, Marco; D’Hertog, Wannes

    2013-01-01

    Glucagon-like peptide-1 (GLP-1) has been shown to protect pancreatic β-cells against cytokine-induced dysfunction and destruction. The mechanisms through which GLP-1 exerts its effects are complex and still poorly understood. The aim of this study was to analyze the protein expression profiles...... of human islets of Langerhans treated with cytokines (IL-1β and IFN-γ) in the presence or absence of GLP-1 by 2D difference gel electrophoresis and subsequent protein interaction network analysis to understand the molecular pathways involved in GLP-1-mediated β-cell protection. Co-incubation of cytokine......-treated human islets with GLP-1 resulted in a marked protection of β-cells against cytokine-induced apoptosis and significantly attenuated cytokine-mediated inhibition of glucose-stimulated insulin secretion. The cytoprotective effects of GLP-1 coincided with substantial alterations in the protein expression...

  6. Immunohistochemical analysis of epithelial cell proliferation in normal-appearing rectal mucosa of patients with colorectal adenoma and cancer using an in vitro labeling method with bromodeoxyuridine.

    OpenAIRE

    Ikeda, Nobumasa; Mizuno,Motowo; Okada, Hiroyuki; Tomoda, Jun; Tsuji,Takao

    1994-01-01

    To identify diffuse mucosal changes which may precede the development of colorectal cancer and a possible indicator for detecting high-risk populations, we immunohistochemically studied cell-cycle events in crypts of normal-appearing rectal mucosa of patients with colorectal adenoma and cancer using an in vitro labeling method with bromodeoxyuridine (BrdU). Biopsy specimens of endoscopically normal-appearing rectal mucosa were obtained during colonoscopy from 20 patients with colorectal adeno...

  7. 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

  8. Pancreatic Islet Transplantation

    Science.gov (United States)

    ... from a living donor, or using islets from pigs. Researchers have transplanted pig islets into other animals, including monkeys, by encapsulating ... are part of clinical research and at the heart of all medical advances. Clinical trials look at ...

  9. Impulse cytophotometric DNA analysis in pituitary adenomas.

    Science.gov (United States)

    Ahyai, A; Hori, A; Bockermann, V; Rama, B; Blech, M; Markakis, E

    1988-01-01

    Flow cytometric DNA analysis was carried out on 32 microsurgically removed pituitary adenomas. Additionally, the histograms of tumor cell nuclei of 7 patients were compared with those of the cultured cells from the same tumor samples. The tumors were classified into 3 groups according to the proliferation index (PI) of the flow cytometric results: 1) tumors with DNA patterns of slow proliferation (PI under 10), to which the majority of the examined pituitary adenomas belonged; 2) pituitary adenomas with diploid karyograms and PI values from 10 to 15; 3) diploid or aneuploid karyograms with PI values above 15. The third group were characterized histologically by increased chromatin content, nuclear polymorphism, mitoses, and extrapituitary infiltration of the tumor cells, and were, therefore, no longer benign. However, there was no direct relationship between the intensity of hormone secretory activity of the tumors and DNA ploidy. Cultured adenoma cells examined by flow cytometry remained stable in all cases but one.

  10. Ketosis onset type 2 diabetes had better islet β-cell function and more serious insulin resistance.

    Science.gov (United States)

    Lu, Hongyun; Hu, Fang; Zeng, Yingjuan; Zou, Lingling; Luo, Shunkui; Sun, Ying; Liu, Hong; Sun, Liao

    2014-01-01

    Diabetic ketosis had been identified as a characteristic of type 1 diabetes mellitus (T1DM), but now emerging evidence has identified that they were diagnosed as T2DM after long time follow up. This case control study was aimed at comparing the clinical characteristic, β-cell function, and insulin resistance of ketosis and nonketotic onset T2DM and providing evidence for treatment selection. 140 cases of newly diagnosed T2DM patients were divided into ketosis (62 cases) and nonketotic onset group (78 cases). After correction of hyperglycemia and ketosis with insulin therapy, plasma C-peptide concentrations were measured at 0, 0.5, 1, 2, and 3 hours after 75 g glucose oral administration. Area under the curve (AUC) of C-peptide was calculated. Homoeostasis model assessment was used to estimate basal β-cell function (HOMA-β) and insulin resistance (HOMA-IR). Our results showed that ketosis onset group had higher prevalence of nonalcoholic fatty liver disease (NAFLD) than nonketotic group (P = 0.04). Ketosis onset group had increased plasma C-peptide levels at 0 h, 0.5 h, and 3 h and higher AUC(0-0.5), AUC₀₋₁, AUC₀₋₃ (P ketosis onset T2DM had better islet β-cell function and more serious insulin resistance than nonketotic onset T2DM.

  11. Glucose Oscillations Can Activate an Endogenous Oscillator in Pancreatic Islets.

    Directory of Open Access Journals (Sweden)

    Joseph P McKenna

    2016-10-01

    Full Text Available Pancreatic islets manage elevations in blood glucose level by secreting insulin into the bloodstream in a pulsatile manner. Pulsatile insulin secretion is governed by islet oscillations such as bursting electrical activity and periodic Ca2+ entry in β-cells. In this report, we demonstrate that although islet oscillations are lost by fixing a glucose stimulus at a high concentration, they may be recovered by subsequently converting the glucose stimulus to a sinusoidal wave. We predict with mathematical modeling that the sinusoidal glucose signal's ability to recover islet oscillations depends on its amplitude and period, and we confirm our predictions by conducting experiments with islets using a microfluidics platform. Our results suggest a mechanism whereby oscillatory blood glucose levels recruit non-oscillating islets to enhance pulsatile insulin output from the pancreas. Our results also provide support for the main hypothesis of the Dual Oscillator Model, that a glycolytic oscillator endogenous to islet β-cells drives pulsatile insulin secretion.

  12. Recent Insights in Islet Amyloid Polypeptide-Induced Membrane Disruption and Its Role in β-Cell Death in Type 2 Diabetes Mellitus

    Directory of Open Access Journals (Sweden)

    Lucie Khemtémourian

    2008-01-01

    Full Text Available The presence of fibrillar protein deposits (amyloid of human islet amyloid polypeptide (hIAPP in the pancreatic islets of Langerhans is thought to be related to death of the insulin-producing islet β-cells in type 2 diabetes mellitus (DM2. The mechanism of hIAPP-induced β-cell death is not understood. However, there is growing evidence that hIAPP-induced disruption of β-cell membranes is the cause of hIAPP cytotoxicity. Amyloid cytotoxicity by membrane damage has not only been suggested for hIAPP, but also for peptides and proteins related to other misfolding diseases, like Alzheimer’s disease, Parkinson’s disease, and prion diseases. Here we review the interaction of hIAPP with membranes, and discuss recent progress in the field, with a focus on hIAPP structure and on the proposed mechanisms of hIAPP-induced membrane damage in relation to β-cell death in DM2.

  13. Hyperpolarization of the Membrane Potential Caused by Somatostatin in Dissociated Human Pituitary Adenoma Cells that Secrete Growth Hormone

    Science.gov (United States)

    Yamashita, Naohide; Shibuya, Naohiko; Ogata, Etsuro

    1986-08-01

    Membrane electrical properties and the response to somatostatin were examined in dissociated human pituitary adenoma cells that secrete growth hormone (GH). Under current clamp condition with a patch electrode, the resting potential was -52.4 ± 8.0 mV, and spontaneous action potentials were observed in 58% of the cells. Under voltage clamp condition an outward K+ current, a tetrodotoxin-sensitive Na+ current, and a Ca2+ current were observed. Cobalt ions suppressed the Ca2+ current. The threshold of Ca2+ current activation was about -60 mV. Somatostatin elicited a membrane hyperpolarization associated with increased membrane permeability in these cells. The reversal potential of somatostatin-induced hyperpolarization was -78.4 ± 4.3 mV in 6 mM K+ medium and -97.2 ± 6.4 mV in 3 mM K+ medium. These reversal potential values and a shift with the external K+ concentration indicated that membrane hyperpolarization was caused by increased permeability to K+. The hyperpolarized membrane potential induced by somatostatin was -63.6 ± 5.9 mV in the standard medium. This level was subthreshold for Ca2+ and Na+ currents and was sufficient to inhibit spontaneous action potentials. Hormone secretion was significantly suppressed by somatostatin and cobalt ions. Therefore, we suggest that Ca2+ entering the cell through voltage-dependent channels are playing an important role for GH secretion and that somatostatin suppresses GH secretion by blocking Ca2+ currents. Finally, we discuss other possibilities for the inhibitory effect of somatostatin on GH secretion.

  14. Postprandial lipemia induces pancreatic α cell dysfunction characteristic of type 2 diabetes: studies in healthy subjects, mouse pancreatic islets, and cultured pancreatic α cells.

    Science.gov (United States)

    Niederwanger, Andreas; Ciardi, Christian; Tatarczyk, Tobias; Khan, Mohammad I; Hermann, Martin; Mittermair, Christof; Al-Zoairy, Ramona; Salzmann, Karin; Pedrini, Michael T

    2014-11-01

    Type 2 diabetes is associated with pancreatic α cell dysfunction, characterized by elevated fasting plasma glucagon concentrations and inadequate postprandial glucose- and insulin-induced suppression of glucagon secretion. The cause and the underlying mechanisms of α cell dysfunction are unknown. Because Western dietary habits cause postprandial lipemia for a major part of a day and, moreover, increase the risk of developing type 2 diabetes, we tested the hypothesis that postprandial lipemia with its characteristic elevation of triglyceride-rich lipoproteins (TGRLs) might cause pancreatic α cell dysfunction. In a crossover study with 7 healthy volunteers, 2 experiments using 2 fat-enriched meals were performed on each volunteer; meal 1 was designed to increase plasma concentrations of both TGRLs and nonesterified fatty acids and meal 2 to increase TGRLs only. Intravenous glucose boli were injected at 0800 after an overnight fast and postprandially at 1300, 3 h after ingestion of a fat-enriched meal. Glucagon concentrations were measured throughout the days of the experiments. In addition to the study in humans, in vitro experiments were performed with mouse pancreatic islets and cultured pancreatic alpha TC 1 clone 9 (αTC1c9) cells, which were incubated with highly purified TGRLs. In humans, postprandial lipemia increased plasma glucagon concentrations and led to an inadequate glucose- and insulin-induced suppression of glucagon. There was no difference between the 2 meal types. In mouse pancreatic islets and cultured pancreatic αTC1c9 cells, purified postprandial TGRLs induced abnormalities in glucagon kinetics comparable with those observed in humans. The TGRL-induced α cell dysfunction was due to reduced γ-aminobutyric acid A receptor activation in pancreatic α cells. We concluded that postprandial lipemia induces pancreatic α cell dysfunction characteristic of type 2 diabetes and, therefore, propose that pancreatic α cell dysfunction could be viewed

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  16. The contribution of Islet1-expressing splanchnic mesoderm cells to distinct branchiomeric muscles reveals significant heterogeneity in head muscle development.

    Science.gov (United States)

    Nathan, Elisha; Monovich, Amir; Tirosh-Finkel, Libbat; Harrelson, Zachary; Rousso, Tal; Rinon, Ariel; Harel, Itamar; Evans, Sylvia M; Tzahor, Eldad

    2008-02-01

    During embryogenesis, paraxial mesoderm cells contribute skeletal muscle progenitors, whereas cardiac progenitors originate in the lateral splanchnic mesoderm (SpM). Here we focus on a subset of the SpM that contributes to the anterior or secondary heart field (AHF/SHF), and lies adjacent to the cranial paraxial mesoderm (CPM), the precursors for the head musculature. Molecular analyses in chick embryos delineated the boundaries between the CPM, undifferentiated SpM progenitors of the AHF/SHF, and differentiating cardiac cells. We then revealed the regionalization of branchial arch mesoderm: CPM cells contribute to the proximal region of the myogenic core, which gives rise to the mandibular adductor muscle. SpM cells contribute to the myogenic cells in the distal region of the branchial arch that later form the intermandibular muscle. Gene expression analyses of these branchiomeric muscles in chick uncovered a distinct molecular signature for both CPM- and SpM-derived muscles. Islet1 (Isl1) is expressed in the SpM/AHF and branchial arch in both chick and mouse embryos. Lineage studies using Isl1-Cre mice revealed the significant contribution of Isl1(+) cells to ventral/distal branchiomeric (stylohyoid, mylohyoid and digastric) and laryngeal muscles. By contrast, the Isl1 lineage contributes to mastication muscles (masseter, pterygoid and temporalis) to a lesser extent, with virtually no contribution to intrinsic and extrinsic tongue muscles or extraocular muscles. In addition, in vivo activation of the Wnt/beta-catenin pathway in chick embryos resulted in marked inhibition of Isl1, whereas inhibition of this pathway increased Isl1 expression. Our findings demonstrate, for the first time, the contribution of Isl1(+) SpM cells to a subset of branchiomeric skeletal muscles.

  17. 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.

  18. 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.

  19. 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.

  20. Differential interleukin-1 receptor antagonism on pancreatic beta and alpha cells. Studies in rodent and human islets and in normal rats

    DEFF Research Database (Denmark)

    Zumsteg, U; Reimers, J I; Pociot, F

    1993-01-01

    The monokines interleukin-1 alpha and -beta have been implicated as effector molecules in the immune-mediated pancreatic beta-cell destruction leading to insulin-dependent diabetes mellitus. Here we investigated the effects of interleukin-1 receptor antagonism on insulin and glucagon release of rat...... thymocytes with a 50% inhibitory concentration of 10- and 100-fold molar excess, respectively. Complete inhibition was obtained with a 100-1,000-fold molar excess. However, at a 100-fold molar excess the interleukin-1 receptor antagonist did not antagonise the potentiating effect of interleukin-1 beta on rat...... islet insulin accumulation during 3 and 6 h of exposure or of interleukin-1 beta-induced inhibition of insulin release after 24 h. In contrast, interleukin-1 beta-stimulated islet glucagon release was completely antagonised by a 100-fold molar excess of interleukin-1 receptor antagonist. A 10,000-fold...

  1. Lixisenatide accelerates restoration of normoglycemia and improves human beta-cell function and survival in diabetic immunodeficient NOD–scid IL-2rgnull RIP-DTR mice engrafted with human islets

    Directory of Open Access Journals (Sweden)

    Yang C

    2015-08-01

    Full Text Available Chaoxing Yang,1 Matthias Loehn,2 Agata Jurczyk,1 Natalia Przewozniak,1 Linda Leehy,1 Pedro L Herrera,3 Leonard D Shultz,4 Dale L Greiner,1 David M Harlan,5 Rita Bortell1 1Program in Molecular Medicine, Diabetes Center of Excellence, University of Massachusetts Medical School, Worcester, MA, USA; 2Sanofi-Aventis, Diabetes Division, Frankfurt, Germany; 3University of Geneva, Geneva, Switzerland; 4The Jackson Laboratory, Bar Harbor, ME, USA; 5Department of Medicine, Diabetes Center of Excellence, University of Massachusetts Medical School, Worcester, MA, USA Objective: Glucagon-like peptide-1 induces glucose-dependent insulin secretion and, in rodents, increases proliferation and survival of pancreatic beta cells. To investigate the effects on human beta cells, we used immunodeficient mice transplanted with human islets. The goal was to determine whether lixisenatide, a glucagon-like peptide-1 receptor agonist, improves human islet function and survival in vivo. Methods: Five independent transplant studies were conducted with human islets from five individual donors. Diabetic human islet-engrafted immunodeficient mice were treated with lixisenatide (50, 150, and 500 µg/kg or vehicle. Islet function was determined by blood glucose, plasma human insulin/C-peptide, and glucose tolerance tests. Grafts were analyzed for total beta- and alpha-cell number, percent proliferation, and levels of apoptosis. Results: Diabetic mice transplanted with marginal human islet mass and treated with lixisenatide were restored to euglycemia more rapidly than vehicle-treated mice. Glucose tolerance tests, human plasma insulin, and glucose-stimulation indices of lixisenatide-treated mice were significantly improved compared to vehicle-treated mice. The percentages of proliferating or apoptotic beta cells at graft recovery were not different between lixisenatide-treated and vehicle-treated mice. Nevertheless, in one experiment we found a significant twofold to threefold

  2. Serum Islet Cell Autoantibodies During Interferon α Treatment in Patients With HCV-Genotype 4 Chronic Hepatitis

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    Gamal Badra

    2006-01-01

    Full Text Available Chronic hepatitis C virus (HCV infection is a leading cause of end-stage liver disease worldwide and HCV genotype 4 (HCV4 is predominant in African and Middle Eastern countries. It is well established that interferon-α (IFNa treatment for HCV may trigger serum autoantibodies against pancreatic islet cells (ICA in a subgroup of patients. Available data on the incidence of ICA during IFNa therapy for chronic HCV4 infection are not conclusive. We investigated the appearance of ICA in 40 naïve Egyptian patients (38 males, 32 ± 6 years with histologically defined chronic HCV4 infection undergoing IFNa treatment at a dose of 9-million U/week for 24 weeks. Serum samples were collected at baseline and following IFNa therapy and ICA were detected using indirect immunofluorescence. Baseline evaluation indicated that 2/40 (5% patients had detectable serum ICA. After the completion of the treatment scheme, 12/38 (32% previously ICA negative patients became ICA positive; however, no patient developed impaired glucose tolerance (IGT or diabetes during follow-up. In conclusion, we submit that IFNa treatment for chronic hepatitis C (CHC may induce serum ICA in one-third of Egyptian patients with HCV4. These autoantibodies, however, do not lead to alterations in glucose metabolism.

  3. Pleomorphic adenoma of the hard palate

    Directory of Open Access Journals (Sweden)

    Kaur S

    2003-03-01

    Full Text Available Pleomorphic adenoma is a benign tumor of the salivary glands that has elements of both epithelial and mesenchymal tissues. The tumor most commonly arises in the parotid or submandibular glands. Infrequently, it may arise from the minor salivary glands and present as an intraoral mass over the palate or lip. We report a patient with pleomorphic adenoma over the hard palate, which resembled common intraoral diseases like condyloma acuminata, oral papilloma and squamous cell carcinoma.

  4. Mammary Analogue Secretory Carcinoma Mimicking Salivary Adenoma

    OpenAIRE

    Williams, Lindsay; Chiosea, Simion I.

    2013-01-01

    Mammary analogue secretory carcinoma (MASC) is a recently described salivary gland tumor characterized by ETV6 translocation. It appears that prior studies have identified MASC by reviewing salivary gland carcinomas, such as acinic cell carcinoma and adenocarcinoma, not otherwise specified. To address the possibility of MASC mimicking benign salivary neoplasms we reviewed 12 salivary gland (cyst)adenomas diagnosed prior to the discovery of MASC. One encapsulated (cyst)adenoma of the parotid g...

  5. miR-145 modulates lncRNA-ROR and Sox2 expression to maintain human amniotic epithelial stem cell pluripotency and β islet-like cell differentiation efficiency.

    Science.gov (United States)

    Zou, Gang; Liu, Te; Guo, Lihe; Huang, Yongyi; Feng, Ya; Huang, Qin; Duan, Tao

    2016-10-10

    In this study, we observed a great reduction in the expression of the endogenous long noncoding RNA ROR (lncRNA-ROR) and the stem cell transcription factor Sox2, in contrast to a marked increase in miR-145 expression, during the course of in vitro induced differentiation of human amniotic epithelial stem cells (HuAECs). Bioinformatics analysis and the luciferase reporter assay revealed binding of miR-145 to specific sites in lncRNA-ROR and Sox2, silencing their expression. Overexpression of a lncRNA-ROR-specific siRNA effectively downregulated the expression levels of Sox2 and other stem cell markers in HuAECs while weakening the efficiency of HuAEC differentiation into β islet-like cells. Moreover, the in vitro response of HuAEC-derived β islet-like cells to extracellular stimuli and C-peptide release by these cells were markedly weakened in the siRNA-ROR transfection group. Furthermore, the in vivo expression of β islet-like cell biomarkers was substantially reduced in HuAECs in the siRNA-ROR transfection group, and their in vivo β islet-like cell differentiation and insulin release capacities were reduced in a streptozocin-induced diabetic rat model. The experimental results indicate that lncRNA-ROR effectively maintains Sox2 gene expression through competitive binding to miR-145, achieving pluripotency maintenance in HuAECs and regulation of their directed β islet-like cell differentiation efficiency. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Ketosis Onset Type 2 Diabetes Had Better Islet β-Cell Function and More Serious Insulin Resistance

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    Hongyun Lu

    2014-01-01

    Full Text Available Diabetic ketosis had been identified as a characteristic of type 1 diabetes mellitus (T1DM, but now emerging evidence has identified that they were diagnosed as T2DM after long time follow up. This case control study was aimed at comparing the clinical characteristic, β-cell function, and insulin resistance of ketosis and nonketotic onset T2DM and providing evidence for treatment selection. 140 cases of newly diagnosed T2DM patients were divided into ketosis (62 cases and nonketotic onset group (78 cases. After correction of hyperglycemia and ketosis with insulin therapy, plasma C-peptide concentrations were measured at 0, 0.5, 1, 2, and 3 hours after 75 g glucose oral administration. Area under the curve (AUC of C-peptide was calculated. Homoeostasis model assessment was used to estimate basal β-cell function (HOMA-β and insulin resistance (HOMA-IR. Our results showed that ketosis onset group had higher prevalence of nonalcoholic fatty liver disease (NAFLD than nonketotic group (P=0.04. Ketosis onset group had increased plasma C-peptide levels at 0 h, 0.5 h, and 3 h and higher AUC0–0.5, AUC0–1, AUC0–3 (P<0.05. Moreover, this group also had higher HOMA-β and HOMA-IR than nonketotic group (P<0.05. From these data, we concluded that ketosis onset T2DM had better islet β-cell function and more serious insulin resistance than nonketotic onset T2DM.

  7. Infection of human islets of Langerhans with two strains of Coxsackie B virus serotype 1: assessment of virus replication, degree of cell death and induction of genes involved in the innate immunity pathway.

    Science.gov (United States)

    Anagandula, Mahesh; Richardson, Sarah J; Oberste, M Steven; Sioofy-Khojine, Amir-Babak; Hyöty, Heikki; Morgan, Noel G; Korsgren, Olle; Frisk, Gun

    2014-08-01

    Type 1 diabetes mellitus is believed to be triggered, in part, by one or more environmental factors and human enteroviruses (HEVs) are among the candidates. Therefore, this study has examined whether two strains of HEV may differentially affect the induction of genes involved in pathways leading to the synthesis of islet hormones, chemokines and cytokines in isolated, highly purified, human islets. Isolated, purified human pancreatic islets were infected with strains of Coxsackievirus B1.Viral replication and the degree of CPE/islet dissociation were monitored. The expression of insulin, glucagon, CXCL10, TLR3, IF1H1, CCL5, OAS-1, IFNβ, and DDX58 was analyzed. Both strains replicated in islets but only one of strain caused rapid islet dissociation/CPE. Expression of the insulin gene was reduced during infection of islets with either viral strain but the gene encoding glucagon was unaffected. All genes analyzed which are involved in viral sensing and the development of innate immunity were induced by Coxsackie B viruses, with the notable exception of TLR3. There was no qualitative difference in the expression pattern between each strain but the magnitude of the response varied between donors. The lack of virus induced expression of TLR3, together with the differential regulation of IF1H1, OAS1 and IFNβ, (each of which has polymorphic variants influence the predisposition to type 1 diabetes), that might result in defective clearance of virus from islet cells. The reduced expression of the insulin gene and the unaffected expression of the gene encoding glucagon by Coxsackie B1 infection is consistent with the preferential β-cell tropism of the virus. © 2013 Wiley Periodicals, Inc.

  8. Short-chain fatty acid level and field cancerization show opposing associations with enteroendocrine cell number and neuropilin expression in patients with colorectal adenoma

    Directory of Open Access Journals (Sweden)

    Staton Carolyn A

    2011-03-01

    Full Text Available Abstract Background Previous reports have suggested that the VEGF receptor neuropilin-1 (NRP-1 is expressed in a singly dispersed subpopulation of cells in the normal colonic epithelium, but that expression becomes dysregulated during colorectal carcinogenesis, with higher levels in tumour suggestive of a poor prognosis. We noted that the spatial distribution and morphology if NRP-1 expressing cells resembles that of enteroendocrine cells (EEC which are altered in response to disease state including cancer and irritable bowel syndrome (IBS. We have shown that NRP-1 is down-regulated by butyrate in colon cancer cell lines in vitro and we hypothesized that butyrate produced in the lumen would have an analogous effect on the colon mucosa in vivo. Therefore we sought to investigate whether NRP-1 is expressed in EEC and how NRP-1 and EEC respond to butyrate and other short-chain fatty acids (SCFA - principally acetate and propionate. Additionally we sought to assess whether there is a field effect around adenomas. Methodology Biopsies were collected at the mid-sigmoid, at the adenoma and at the contralateral wall (field of 28 subjects during endoscopy. Samples were fixed for IHC and stained for either NRP-1 or for chromogranin A (CgA, a marker of EEC. Stool sampling was undertaken to assess individuals' butyrate, acetate and propionate levels. Result NRP-1 expression was inversely related to SCFA concentration at the colon landmark (mid-sigmoid, but expression was lower and not related to SCFA concentration at the field. Likewise CgA+ cell number was also inversely related to SCFA at the landmark, but was lower and unresponsive at the field. Crypt cellularity was unaltered by field effect. A colocalisation analysis showed only a small subset of NRP-1 localised with CgA. Adenomas showed extensive, weaker staining for NRP-1 which contrastingly correlated positively with butyrate level. Field effects cause this relationship to be lost. Adenoma tissue

  9. Anti-CD154 mAb and rapamycin induce T regulatory cell mediated tolerance in rat-to-mouse islet transplantation.

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    Yannick D Muller

    Full Text Available BACKGROUND: Anti-CD154 (MR1 monoclonal antibody (mAb and rapamycin (RAPA treatment both improve survival of rat-to-mouse islet xenograft. The present study investigated the effect of combined RAPA/MR1 treatment on rat-to-mouse islet xenograft survival and analyzed the role of CD4(+CD25(+Foxp3(+ T regulatory cells (Treg in the induction and maintenance of the ensuing tolerance. METHODOLOGY/PRINCIPAL FINDINGS: C57BL/6 mice were treated with MR1/RAPA and received additional monoclonal anti-IL2 mAb or anti CD25 mAb either early (0-28 d or late (100-128 d post-transplantation. Treg were characterised in the blood, spleen, draining lymph nodes and within the graft of tolerant and rejecting mice by flow cytometry and immunohistochemistry. Fourteen days of RAPA/MR1 combination therapy allowed indefinite islet graft survival in >80% of the mice. Additional administration of anti-IL-2 mAb or depleting anti-CD25 mAb at the time of transplantation resulted in rejection (100% and 89% respectively, whereas administration at 100 days post transplantation lead to lower rejection rates (25% and 40% respectively. Tolerant mice showed an increase of Treg within the graft and in draining lymph nodes early post transplantation, whereas 100 days post transplantation no significant increase of Treg was observed. Rejecting mice showed a transient increase of Treg in the xenograft and secondary lymphoid organs, which disappeared within 7 days after rejection. CONCLUSIONS/SIGNIFICANCES: These results suggest a critical role for Treg in the induction phase of tolerance early after islet xenotransplantation. These encouraging data support the need of developing further Treg therapy for overcoming the species barrier in xenotransplantation.

  10. Fibrin supports human fetal islet-epithelial cell differentiation via p70(s6k) and promotes vascular formation during transplantation.

    Science.gov (United States)

    Riopel, Matthew; Li, Jinming; Trinder, Mark; Fellows, George F; Wang, Rennian

    2015-08-01

    The human fetal pancreas expresses a variety of extracellular matrix (ECM) binding receptors known as integrins. A provisional ECM protein found in blood clots that can bind to integrin receptors and promote β cell function and survival is fibrin. However, its role in support of human fetal pancreatic cells is unknown. We investigated how fibrin promotes human fetal pancreatic cell differentiation in vitro and in vivo. Human fetal pancreata were collected from 15 to 21 weeks of gestation and collagenase digested. Cells were then plated on tissue-culture polystyrene, or with 2D or 3D fibrin gels up to 2 weeks, or subcutaneously transplanted in 3D fibrin gels. The human fetal pancreas contained rich ECM proteins and expressed integrin αVβ3. Fibrin-cultured human fetal pancreatic cells had significantly increased expression of PDX-1, glucagon, insulin, and VEGF-A, along with increased integrin αVβ3 and phosphorylated FAK and p70(s6k). Fibrin-cultured cells treated with rapamycin, the mTOR pathway inhibitor, had significantly decreased phospho-p70(s6k) and PDX-1 expression. Transplanting fibrin-mixed cells into nude mice improved vascularization compared with collagen controls. These results suggest that fibrin supports islet cell differentiation via p70(s6k) and promotes vascularization in human fetal islet-epithelial clusters in vivo.

  11. Pleomorphic adenoma of the palate.

    Science.gov (United States)

    Debnath, Subhas Chandra; Saikia, A K; Debnath, Antara

    2010-12-01

    Pleomorphic adenoma is a benign tumor of the salivary glands that has elements of both epithelial and mesenchymal tissues. The tumor most commonly arises in the parotid or submandibular glands. Infrequently, it may arise from the minor salivary glands and present as an intraoral mass over the palate or lip. We report a patient with PA over the hard palate, which resembled common intraoral diseases like oral papilloma, squamous cell carcinoma and condyloma acuminate.

  12. Pleomorphic Adenoma of the Palate

    OpenAIRE

    Debnath, Subhas Chandra; Saikia, A. K.; Debnath, Antara

    2010-01-01

    Pleomorphic adenoma is a benign tumor of the salivary glands that has elements of both epithelial and mesenchymal tissues. The tumor most commonly arises in the parotid or submandibular glands. Infrequently, it may arise from the minor salivary glands and present as an intraoral mass over the palate or lip. We report a patient with PA over the hard palate, which resembled common intraoral diseases like oral papilloma, squamous cell carcinoma and condyloma acuminate.

  13. Neurotransmitters act as paracrine signals to regulate insulin secretion from the human pancreatic islet

    Science.gov (United States)

    Rodriguez-Diaz, Rayner; Menegaz, Danusa; Caicedo, Alejandro

    2014-01-01

    In this symposium review we discuss the role of neurotransmitters as paracrine signals that regulate pancreatic islet function. A large number of neurotransmitters and their receptors has been identified in the islet, but relatively little is known about their involvement in islet biology. Interestingly, neurotransmitters initially thought to be present in autonomic axons innervating the islet are also present in endocrine cells of the human islet. These neurotransmitters can thus be released as paracrine signals to help control hormone release. Here we propose that the role of neurotransmitters may extend beyond controlling endocrine cell function to work as signals modulating vascular flow and immune responses within the islet. PMID:24591573

  14. Pancreatic Islet Survival and Engraftment Is Promoted by Culture on Functionalized Spider Silk Matrices.

    Science.gov (United States)

    Johansson, Ulrika; Ria, Massimiliano; Åvall, Karin; Dekki Shalaly, Nancy; Zaitsev, Sergei V; Berggren, Per-Olof; Hedhammar, My

    2015-01-01

    Transplantation of pancreatic islets is one approach for treatment of diabetes, however, hampered by the low availability of viable islets. Islet isolation leads to disruption of the environment surrounding the endocrine cells, which contributes to eventual cell death. The reestablishment of this environment is vital, why we herein investigated the possibility of using recombinant spider silk to support islets in vitro after isolation. The spider silk protein 4RepCT was formulated into three different formats; 2D-film, fiber mesh and 3D-foam, in order to provide a matrix that can give the islets physical support in vitro. Moreover, cell-binding motifs from laminin were incorporated into the silk protein in order to create matrices that mimic the natural cell environment. Pancreatic mouse islets were thoroughly analyzed for adherence, necrosis and function after in vitro maintenance on the silk matrices. To investigate their suitability for transplantation, we utilized an eye model which allows in vivo imaging of engraftment. Interestingly, islets that had been maintained on silk foam during in vitro culture showed improved revascularization. This coincided with the observation of preserved islet architecture with endothelial cells present after in vitro culture on silk foam. Selected matrices were further evaluated for long-term preservation of human islets. Matrices with the cell-binding motif RGD improved human islet maintenance (from 36% to 79%) with preserved islets architecture and function for over 3 months in vitro. The islets established cell-matrix contacts and formed vessel-like structures along the silk. Moreover, RGD matrices promoted formation of new, insulin-positive islet-like clusters that were connected to the original islets via endothelial cells. On silk matrices with islets from younger donors (<35 year), the amount of newly formed islet-like clusters found after 1 month in culture were almost double compared to the initial number of islets

  15. Pancreatic Islet Survival and Engraftment Is Promoted by Culture on Functionalized Spider Silk Matrices

    Science.gov (United States)

    Johansson, Ulrika; Dekki Shalaly, Nancy; Zaitsev, Sergei V.; Berggren, Per-Olof; Hedhammar, My

    2015-01-01

    Transplantation of pancreatic islets is one approach for treatment of diabetes, however, hampered by the low availability of viable islets. Islet isolation leads to disruption of the environment surrounding the endocrine cells, which contributes to eventual cell death. The reestablishment of this environment is vital, why we herein investigated the possibility of using recombinant spider silk to support islets in vitro after isolation. The spider silk protein 4RepCT was formulated into three different formats; 2D-film, fiber mesh and 3D-foam, in order to provide a matrix that can give the islets physical support in vitro. Moreover, cell-binding motifs from laminin were incorporated into the silk protein in order to create matrices that mimic the natural cell environment. Pancreatic mouse islets were thoroughly analyzed for adherence, necrosis and function after in vitro maintenance on the silk matrices. To investigate their suitability for transplantation, we utilized an eye model which allows in vivo imaging of engraftment. Interestingly, islets that had been maintained on silk foam during in vitro culture showed improved revascularization. This coincided with the observation of preserved islet architecture with endothelial cells present after in vitro culture on silk foam. Selected matrices were further evaluated for long-term preservation of human islets. Matrices with the cell-binding motif RGD improved human islet maintenance (from 36% to 79%) with preserved islets architecture and function for over 3 months in vitro. The islets established cell-matrix contacts and formed vessel-like structures along the silk. Moreover, RGD matrices promoted formation of new, insulin-positive islet-like clusters that were connected to the original islets via endothelial cells. On silk matrices with islets from younger donors (<35 year), the amount of newly formed islet-like clusters found after 1 month in culture were almost double compared to the initial number of islets

  16. Pituitary lymphoma developing within pituitary adenoma.

    Science.gov (United States)

    Morita, Ken; Nakamura, Fumihiko; Kamikubo, Yasuhiko; Mizuno, Naoaki; Miyauchi, Masashi; Yamamoto, Go; Nannya, Yasuhito; Ichikawa, Motoshi; Kurokawa, Mineo

    2012-06-01

    Lymphoma occurring in the pituitary gland is an exceedingly infrequent event. Here, we describe a case of pituitary lymphoma complicating recurrent pituitary adenoma. A 56-year-old male with a history of pituitary adenoma was diagnosed with diffuse large B-cell lymphoma (DLBCL) of the left ocular adnexa, which was successfully treated by standard chemotherapy and local radiotherapy. Eight months later, he complained of diplopia and bitemporal hemianopia. Brain magnetic resonance imaging detected a suprasellar tumor. Transsphenoidal biopsy of the mass was performed, and histopathological examination revealed DLBCL admixed with pituitary adenoma. On a review of the literature, we found that pituitary lymphoma developing within adenoma is a recurrent phenomenon. The composite tumor is likely to be characterized by suprasellar involvement and presentation of visual disturbances. Moreover, in the present case, the suprasellar tumor remained visible after autologous peripheral stem cell transplant, likely due to the residual pituitary adenoma. We therefore recommend that refractory pituitary lymphoma should be vigorously biopsied in search of possibly underlying adenoma.

  17. Islet Oxygen Consumption Rate (OCR Dose Predicts Insulin Independence in Clinical Islet Autotransplantation.

    Directory of Open Access Journals (Sweden)

    Klearchos K Papas

    Full Text Available Reliable in vitro islet quality assessment assays that can be performed routinely, prospectively, and are able to predict clinical transplant outcomes are needed. In this paper we present data on the utility of an assay based on cellular oxygen consumption rate (OCR in predicting clinical islet autotransplant (IAT insulin independence (II. IAT is an attractive model for evaluating characterization assays regarding their utility in predicting II due to an absence of confounding factors such as immune rejection and immunosuppressant toxicity.Membrane integrity staining (FDA/PI, OCR normalized to DNA (OCR/DNA, islet equivalent (IE and OCR (viable IE normalized to recipient body weight (IE dose and OCR dose, and OCR/DNA normalized to islet size index (ISI were used to characterize autoislet preparations (n = 35. Correlation between pre-IAT islet product characteristics and II was determined using receiver operating characteristic analysis.Preparations that resulted in II had significantly higher OCR dose and IE dose (p<0.001. These islet characterization methods were highly correlated with II at 6-12 months post-IAT (area-under-the-curve (AUC = 0.94 for IE dose and 0.96 for OCR dose. FDA/PI (AUC = 0.49 and OCR/DNA (AUC = 0.58 did not correlate with II. OCR/DNA/ISI may have some utility in predicting outcome (AUC = 0.72.Commonly used assays to determine whether a clinical islet preparation is of high quality prior to transplantation are greatly lacking in sensitivity and specificity. While IE dose is highly predictive, it does not take into account islet cell quality. OCR dose, which takes into consideration both islet cell quality and quantity, may enable a more accurate and prospective evaluation of clinical islet preparations.

  18. Interleukin-8 production from human somatotroph adenoma cells is stimulated by interleukin-1β and inhibited by growth hormone releasing hormone and somatostatin

    DEFF Research Database (Denmark)

    Vindeløv, Signe Diness; Hartoft-Nielsen, Marie-Louise; Rasmussen, Åse Krogh

    2011-01-01

    Pituitary adenomas cause morbidity and mortality due to their localization and influence on pituitary hormone secretion. Although the pathogenesis of pituitary adenomas is unclear, studies have indicated that cytokines are involved. We investigated the role of cytokines, in particular interleukin...

  19. Effects of the Janus Kinase Inhibitor, Tofacitinib, on Testicular Leydig Cell Hyperplasia and Adenoma in Rats, and on Prolactin Signaling in Cultured Primary Rat Leydig Cells.

    Science.gov (United States)

    Chapin, Robert E; Ball, Douglas J; Radi, Zaher A; Kumpf, Steven W; Koza-Taylor, Petra H; Potter, David M; Mark Vogel, W

    2017-01-01

    Tofacitinib is an oral Janus kinase (JAK) inhibitor for the treatment of rheumatoid arthritis. Tofacitinib preferentially inhibits receptor signaling through JAK3 and JAK1, relative to JAK2. In the 2-year rat carcinogenicity study, there were tofacitinib, dose-related increases in the incidences of testicular Leydig cell hyperplasia and benign adenomas in male rats, and decreased incidences of mammary tumors and duct dilatation/galactocele in female rats. Such findings in rats are typical of agents, such as dopamine agonists, which decrease prolactin (PRL) activity. Since prolactin signals through the JAK2 pathway, we hypothesized that these findings were off-target effects due to inhibition of PRL signaling via JAK2. The studies reported here were designed to investigate the interruption of PRL signaling pathways in Leydig cells. In isolated primary rat Leydig cells, PRL increased phosphorylated Signal Transducer and Activator of Transcription-5 protein, and mRNA levels for luteinizing hormone receptor. Tofacitinib, at concentrations observed in the rat carcinogenicity study, dose-dependently inhibited these effects. These observations illustrate a novel mechanism, the inhibition of prolactin signaling by which modulation of JAK activity can modulate PRL signaling pathways to induce Leydig cell tumors in rats. Since human Leydig cells lack this PRL dependence for normal function, these rodent tumors do not indicate a health risk to human patients. © The Author 2016. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  20. An insulin signaling feedback loop regulates pancreas progenitor cell differentiation during islet development and regeneration.

    Science.gov (United States)

    Ye, Lihua; Robertson, Morgan A; Mastracci, Teresa L; Anderson, Ryan M

    2016-01-15

    As one of the key nutrient sensors, insulin signaling plays an important role in integrating environmental energy cues with organism growth. In adult organisms, relative insufficiency of insulin signaling induces compensatory expansion of insulin-secreting pancreatic beta (β) cells. However, little is known about how insulin signaling feedback might influence neogenesis of β cells during embryonic development. Using genetic approaches and a unique cell transplantation system in developing zebrafish, we have uncovered a novel role for insulin signaling in the negative regulation of pancreatic progenitor cell differentiation. Blocking insulin signaling in the pancreatic progenitors hastened the expression of the essential β cell genes insulin and pdx1, and promoted β cell fate at the expense of alpha cell fate. In addition, loss of insulin signaling promoted β cell regeneration and destabilization of alpha cell character. These data indicate that insulin signaling constitutes a tunable mechanism for β cell compensatory plasticity during early development. Moreover, using a novel blastomere-to-larva transplantation strategy, we found that loss of insulin signaling in endoderm-committed blastomeres drove their differentiation into β cells. Furthermore, the extent of this differentiation was dependent on the function of the β cell mass in the host. Altogether, our results indicate that modulation of insulin signaling will be crucial for the development of β cell restoration therapies for diabetics; further clarification of the mechanisms of insulin signaling in β cell progenitors will reveal therapeutic targets for both in vivo and in vitro β cell generation. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Role of MicroRNAs in Islet Beta-Cell Compensation and Failure during Diabetes

    Directory of Open Access Journals (Sweden)

    Valérie Plaisance

    2014-01-01

    Full Text Available Pancreatic beta-cell function and mass are markedly adaptive to compensate for the changes in insulin requirement observed during several situations such as pregnancy, obesity, glucocorticoids excess, or administration. This requires a beta-cell compensation which is achieved through a gain of beta-cell mass and function. Elucidating the physiological mechanisms that promote functional beta-cell mass expansion and that protect cells against death, is a key therapeutic target for diabetes. In this respect, several recent studies have emphasized the instrumental role of microRNAs in the control of beta-cell function. MicroRNAs are negative regulators of gene expression, and are pivotal for the control of beta-cell proliferation, function, and survival. On the one hand, changes in specific microRNA levels have been associated with beta-cell compensation and are triggered by hormones or bioactive peptides that promote beta-cell survival and function. Conversely, modifications in the expression of other specific microRNAs contribute to beta-cell dysfunction and death elicited by diabetogenic factors including, cytokines, chronic hyperlipidemia, hyperglycemia, and oxidized LDL. This review underlines the importance of targeting the microRNA network for future innovative therapies aiming at preventing the beta-cell decline in diabetes.

  2. Modeling spatial distribution of oxygen in 3d culture of islet beta-cells.

    Science.gov (United States)

    McReynolds, John; Wen, Yu; Li, Xiaofei; Guan, Jianjun; Jin, Sha

    2017-01-01

    Three-dimensional (3D) scaffold culture of pancreatic β-cell has been proven to be able to better mimic physiological conditions in the body. However, one critical issue with culturing pancreatic β-cells is that β-cells consume large amounts of oxygen, and hence insufficient oxygen supply in the culture leads to loss of β-cell mass and functions. This becomes more significant when cells are cultured in a 3D scaffold. In this study, in order to understand the effect of oxygen tension inside a cell-laden collagen culture on β-cell proliferation, a culture model with encapsulation of an oxygen-generator was established. The oxygen-generator was made by embedding hydrogen peroxide into nontoxic polydimethylsiloxane to avoid the toxicity of a chemical reaction in the β-cell culture. To examine the effectiveness of the oxygenation enabled 3D culture, the spatial-temporal distribution of oxygen tension inside a scaffold was evaluated by a mathematical modeling approach. Our simulation results indicated that an oxygenation-aided 3D culture would augment the oxygen supply required for the β-cells. Furthermore, we identified that cell seeding density and the capacity of the oxygenator are two critical parameters in the optimization of the culture. Notably, cell-laden scaffold cultures with an in situ oxygen supply significantly improved the β-cells' biological function. These β-cells possess high insulin secretion capacity. The results obtained in this work would provide valuable information for optimizing and encouraging functional β-cell cultures. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 33:221-228, 2017. © 2016 American Institute of Chemical Engineers.

  3. Acinar Cell Cyst adenoma (Acinar Cystic Transformation) of the Pancreas: the Radiologic-Pathologic Features

    Energy Technology Data Exchange (ETDEWEB)

    Gumus, Mehmet; Algin, Oktay; Gundogdu, Haldun [Ataturk Training and Research Hospital, Ankara (Turkmenistan); Ugras, Serdar [Selcuk University, Selcuklu Medical Faculty, Konya (Turkmenistan)

    2011-02-15

    Acinar cystic transformation of the pancreas is also known as acinar cell cystadenoma (ACC), and this is an extremely rare benign lesion that was first described in April 2002. We report here on a case of a previously asymptomatic patient with pancreatic ACC and this was diagnosed by computed tomography (CT) and magnetic resonance imaging (MRI). To the best of our knowledge, there is no previous report concerning the CT or MRI features of ACC in the medical literature. We present here the CT, MRI and pathological findings of pancreatic ACC

  4. Dual role for Islet-1 in promoting striatonigral and repressing striatopallidal genetic programs to specify striatonigral cell identity.

    Science.gov (United States)

    Lu, Kuan-Ming; Evans, Sylvia M; Hirano, Shinji; Liu, Fu-Chin

    2014-01-07

    Striatal projection neurons comprise two populations of striatonigral and striatopallidal neurons. These two neuronal populations play distinct roles in controlling movement-related functions in the basal ganglia circuits. An important issue is how striatal progenitors are developmentally specified into these two distinct neuronal populations. In the present study, we characterized the function of Islet-1 (Isl1), a LIM-homeodomain transcription factor, in striatal development. Genetic fate mapping showed that Isl1(+) progeny specifically developed into a subpopulation of striatonigral neurons that transiently expressed Isl1. In Nestin-Cre;Isl1(f/f) KO mouse brain, differentiation of striatonigral neurons was defective, as evidenced by decreased expression of striatonigral-enriched genes, including substance P, prodynorphin, solute carrier family 35, member D3 (Slc35d3), and PlexinD1. Striatonigral axonal projections were also impaired, and abnormal apoptosis was observed in Isl1 KO striatum. It was of particular interest that striatopallidal-enriched genes, including dopamine D2 receptor (Drd2), proenkephalin, A2A adenosine receptor (A2aR) and G protein-coupled receptor 6 (Gpr6), were concomitantly up-regulated in Isl1 mutant striatum, suggesting derepression of striatopallidal genes in striatonigral neurons in the absence of Isl1. The suppression of striatopallidal genes by Isl1 was further examined by overexpression of Isl1 in the striatum of Drd2-EGFP transgenic mice using in utero electroporation. Ectopic Isl1 expression was sufficient to repress Drd2-EGFP signals in striatopallidal neurons. Taken together, our study suggests that Isl1 specifies the cell fate of striatonigral neurons not only by orchestrating survival, differentiation, and axonal projections of striatonigral neurons but also by suppressing striatopallidal-enriched genes. The dual action of developmental control by Isl1 in promoting appropriate striatonigral but repressing inappropriate

  5. Pathogenesis of coxsackievirus-B5 acquired from intra-renal porcine islet cell xenografts in diabetic mice.

    Science.gov (United States)

    Myers, Suzanne E; LaRue, Rebecca; Shaw, Daniel P; Love, Brenda C; M, Kariuki Njenga; Njenga, Moses K

    2009-01-01

    We previously demonstrated the ability of a human isolate of coxsackievirus-B5 (CVB5) to infect productively adult porcine islet cells (PICs) in vitro. PICs infected with CVB5 remain viable, and upon transplantation reversed diabetes in C56BL/6 mice for up to 5 days. In the present work, we expanded this graft-to-host xenozoonosis model by examining the long-term functionality of CVB5-infected PIC xenografts in immunosuppressed mice. And, we characterized the pathogenesis of CVB5 infection in mice resulting from directional transmission of the virus from PIC xenografts to surrounding tissues in a mouse model for immunosuppressed human PIC xenograft recipients. Both acutely (12 h) and chronically (72 h) infected PIC xenografts functioned in vivo to reverse diabetes in mice. The efficacy of both infected and un-infected PICs was transient beyond 5 days post-inoculation and the long-term functionality of the grafts was compromised by host-to-graft rejection. CVB5-infected PIC xenografts transmitted infectious virus to immunosuppressed recipient mice resulting in extensive histopathologic changes. The virus replicated in the heart, liver, spleen, kidney, pancreas, brain and skeletal muscle in higher levels in severe-combined immunodeficient (SCID) mice that were directly inoculated with virus when compared to controls. In addition, infectious virus was recovered for up to 22 days after inoculation in SCID mice whereas it was only detected up to Day 4 PI in non-SCID mice. Immunosuppressed PIC xenograft recipients may be more susceptible to infection with CVB5 which could target the xenograft leading to disseminated infection in the host.

  6. Cost-effectiveness of total pancreatectomy and islet cell autotransplantation for the treatment of minimal change chronic pancreatitis.

    Science.gov (United States)

    Wilson, Gregory C; Ahmad, Syed A; Schauer, Daniel P; Eckman, Mark H; Abbott, Daniel E

    2015-01-01

    The current standard of care for the management of minimal change chronic pancreatitis (MCCP) is medical management. Controversy exists, however, regarding the use of surgical intervention for MCCP. We hypothesized that total pancreatectomy and islet cell autotransplantation (TPIAT) decreases long-term resource utilization and improves quality of life, justifying initial costs and risks. Detailed perioperative outcomes from 46 patients with MCCP populated a Markov model comparing medical management to TPIAT. Mortality, complications, readmission rates, insulin and narcotic use, imaging, and endoscopy were included in the model. Outcomes reported were survival, measured in quality-adjusted life years (QALYs), and costs, in 2013 US dollars. In medical patients, annual mean hospital admissions were 1.6 (range = 0-11), endoscopy 1.4 (0-6), and imaging (CT/MRI) 1.5 (0-4). In surgical patients, there were no perioperative deaths, with complication and 30-day readmission rates of 47 and 37%. One year after TPIAT, annual mean admissions, endoscopy, and imaging had decreased to 0.9 (0-4), 0.4 (0-2), and 0.9 (0-5); monthly narcotic use decreased from 138 to 37 morphine equivalents (p = 0.012). Cost and survival for TPIAT versus medical management were $153,575/14.9 QALYs and $196,042/11.5 QALYs, respectively. In patients with MCCP, TPIAT is associated with decreased cost and increased quality-adjusted survival. Providers and insurers should more enthusiastically embrace TPIAT use as a more effective cost-saving strategy.

  7. Targeting recombinant adeno-associated virus vectors to enhance gene transfer to pancreatic islets and liver

    National Research Council Canada - National Science Library

    Loiler, S A; Conlon, T J; Song, S; Tang, Q; Warrington, K H; Agarwal, A; Kapturczak, M; Li, C; Ricordi, C; Atkinson, M A; Muzyczka, N; Flotte, T R

    2003-01-01

    .... Here we report that nonserotype 2 AAV capsids can mediate more efficient transduction of islet cells, with AAV1 being the most efficient serotype in murine islets, suggesting that receptor abundance could be limiting...

  8. Microfluidic platform for assessing pancreatic islet functionality through dielectric spectroscopy

    Science.gov (United States)

    Heileman, K.; Daoud, J.; Hasilo, C.; Gasparrini, M.; Paraskevas, S.; Tabrizian, M.

    2015-01-01

    Human pancreatic islets are seldom assessed for dynamic responses to external stimuli. Thus, the elucidation of human islet functionality would provide insights into the progression of diabetes mellitus, evaluation of preparations for clinical transplantation, as well as for the development of novel therapeutics. The objective of this study was to develop a microfluidic platform for in vitro islet culture, allowing the multi-parametric investigation of islet response to chemical and biochemical stimuli. This was accomplished through the fabrication and implementation of a microfluidic platform that allowed the perifusion of islet culture while integrating real-time monitoring using impedance spectroscopy, through microfabricated, interdigitated electrodes located along the microchamber arrays. Real-time impedance measurements provide important dielectric parameters, such as cell membrane capacitance and cytoplasmic conductivity, representing proliferation, differentiation, viability, and functionality. The perifusion of varying glucose concentrations and monitoring of the resulting impedance of pancreatic islets were performed as proof-of-concept validation of the lab-on-chip platform. This novel technique to elucidate the underlying mechanisms that dictate islet functionality is presented, providing new information regarding islet function that could improve the evaluation of islet preparations for transplantation. In addition, it will lead to a better understanding of fundamental diabetes-related islet dysfunction and the development of therapeutics through evaluation of potential drug effects. PMID:26339324

  9. Gliadin fragments and a specific gliadin 33-mer peptide close KATP channels and induce insulin secretion in INS-1E cells and rat islets of langerhans.

    Directory of Open Access Journals (Sweden)

    Morten Dall

    Full Text Available In non-obese diabetic (NOD mice, diabetes incidence is reduced by a gluten-free diet. Gluten peptides, such as the compound gliadin, can cross the intestinal barrier and may directly affect pancreatic beta cells. We investigated the effects of enzymatically-digested gliadin in NOD mice, INS-1E cells and rat islets. Six injections of gliadin digest in 6-week-old NOD mice did not affect diabetes development, but increased weight gain (20% increase by day 100. In INS-1E cells, incubation with gliadin digest induced a dose-dependent increase in insulin secretion, up to 2.5-fold after 24 hours. A similar effect was observed in isolated rat islets (1.6-fold increase. In INS-1E cells, diazoxide reduced the stimulatory effect of gliadin digest. Additionally, gliadin digest was shown to decrease current through KATP-channels. A specific gliadin 33-mer had a similar effect, both on current and insulin secretion. Finally, INS-1E incubation with gliadin digest potentiated palmitate-induced insulin secretion by 13% compared to controls. Our data suggest that gliadin fragments may contribute to the beta-cell hyperactivity observed prior to the development of type 1 diabetes.

  10. Direct measurements of oscillatory glycolysis in pancreatic islet β-cells using novel fluorescence resonance energy transfer (FRET) biosensors for pyruvate kinase M2 activity.

    Science.gov (United States)

    Merrins, Matthew J; Van Dyke, Aaron R; Mapp, Anna K; Rizzo, Mark A; Satin, Leslie S

    2013-11-15

    Pulses of insulin released from pancreatic β-cells maintain blood glucose in a narrow range, although the source of these pulses is unclear. We and others have proposed that positive feedback mediated by the glycolytic enzyme phosphofructokinase-1 (PFK1) enables β-cells to generate metabolic oscillations via autocatalytic activation by its product fructose 1,6-bisphosphate (FBP). Although much indirect evidence has accumulated in favor of this hypothesis, a direct measurement of oscillating glycolytic intermediates has been lacking. To probe glycolysis directly, we engineered a family of inter- and intramolecular FRET biosensors based on the glycolytic enzyme pyruvate kinase M2 (PKAR; pyruvate kinase activity reporter), which multimerizes and is activated upon binding FBP. When introduced into Min6 β-cells, PKAR FRET efficiency increased rapidly in response to glucose. Importantly, however, metabolites entering downstream of PFK1 (glyceraldehyde, pyruvate, and ketoisocaproate) failed to activate PKAR, consistent with sensor activation by FBP; the dependence of PKAR on FBP was further confirmed using purified sensor in vitro. Using a novel imaging modality for monitoring mitochondrial flavin fluorescence in mouse islets, we show that slow oscillations in mitochondrial redox potential stimulated by 10 mm glucose are in phase with glycolytic efflux through PKM2, measured simultaneously from neighboring islet β-cells expressing PKAR. These results indicate that PKM2 activity in β-cells is oscillatory and are consistent with pulsatile PFK1 being the mediator of slow glycolytic oscillations.

  11. Direct Measurements of Oscillatory Glycolysis in Pancreatic Islet β-Cells Using Novel Fluorescence Resonance Energy Transfer (FRET) Biosensors for Pyruvate Kinase M2 Activity*♦

    Science.gov (United States)

    Merrins, Matthew J.; Van Dyke, Aaron R.; Mapp, Anna K.; Rizzo, Mark A.; Satin, Leslie S.

    2013-01-01

    Pulses of insulin released from pancreatic β-cells maintain blood glucose in a narrow range, although the source of these pulses is unclear. We and others have proposed that positive feedback mediated by the glycolytic enzyme phosphofructokinase-1 (PFK1) enables β-cells to generate metabolic oscillations via autocatalytic activation by its product fructose 1,6-bisphosphate (FBP). Although much indirect evidence has accumulated in favor of this hypothesis, a direct measurement of oscillating glycolytic intermediates has been lacking. To probe glycolysis directly, we engineered a family of inter- and intramolecular FRET biosensors based on the glycolytic enzyme pyruvate kinase M2 (PKAR; pyruvate kinase activity reporter), which multimerizes and is activated upon binding FBP. When introduced into Min6 β-cells, PKAR FRET efficiency increased rapidly in response to glucose. Importantly, however, metabolites entering downstream of PFK1 (glyceraldehyde, pyruvate, and ketoisocaproate) failed to activate PKAR, consistent with sensor activation by FBP; the dependence of PKAR on FBP was further confirmed using purified sensor in vitro. Using a novel imaging modality for monitoring mitochondrial flavin fluorescence in mouse islets, we show that slow oscillations in mitochondrial redox potential stimulated by 10 mm glucose are in phase with glycolytic efflux through PKM2, measured simultaneously from neighboring islet β-cells expressing PKAR. These results indicate that PKM2 activity in β-cells is oscillatory and are consistent with pulsatile PFK1 being the mediator of slow glycolytic oscillations. PMID:24100037

  12. Heterogeneity of secretory granules of silent pituitary adenomas

    DEFF Research Database (Denmark)

    Holck, S; Wewer, U M; Albrechtsen, R

    1988-01-01

    Silent pituitary adenomas were compared with hormonally active tumors taking into account the size, number, and ultrastructural characteristics of secretory granules (SG). The study group (a total of 79 primary pituitary adenomas) comprised 27 silent, 21 growth hormone (GH)-producing-, 16 prolactin...... approximately 10 to 50% of the granules in each cell. These granules were not seen in hormonally active tumors and considered therefore diagnostic of silent pituitary adenomas....... (PRL)-producing-, 5 GH-PRL-producing- and 10 adrenocorticotropic hormone (ACTH)-producing adenomas. The SG of silent adenomas were significantly smaller than SG in endocrine active adenomas. All hormonally inactive tumors also contained small (mean, 94 nm) specific cytoplasmic granules, designated...

  13. The intrinsic rhythmicity of spike-burst generation in pancreatic beta-cells and intercellular interaction within an islet.

    Science.gov (United States)

    Kitasato, H; Kai, R; Ding, W G; Omatsu-Kanbe, M

    1996-10-01

    The pancreatic beta-cell has four types of Ca2+ channel (L-type, T-type, low-threshold slowly inactivating, and low-threshold non-inactivating Ca2+), although the low-threshold non-inactivating Ca2+ channel has not yet been confirmed experimentally. Beside these, there are at least three types of K+ channels (K(ATP), K(Ca,V), and K(V)), and transporters (GLUT-2, Na+/Ca(2+)-countertransporter, and Na+/K(+)-pump) as schematically shown in Fig.4. Opinions on the mechanism of spike-burst are converging to the following view: At intermediate glucose concentrations, the intracellular ATP/ADP ratio oscillates in the following way. A gradual rise in the ATP/ADP ratio causes gradual progression of depolarization to the threshold for the low-threshold Ca2+ channels, of which the opening causes regenerative depolarization to the plateau potential on which spikes (the L-type Ca2+ channel contributes to spike firing) are superimposed. During the active phase, a fall in the ATP/ADP ratio follows a gradual rise in ATP consumption. Slight repolarization due to the opening of a small fraction of K(ATP) channels triggers regenerative repolarization. With the progress of repolarization, a residual fraction of voltage-gated Ca2+ channels (low-threshold non-inactivating) are deactivated. During the silent phase, a gradual rise in the ATP/ ADP ratio leads to gradual depolarization back to the threshold for the next spike-burst. There are still a diversity of views regarding the mechanism of the initial spike-train. On the basis of observations made in various laboratories including ours, we propose the following working model: At low concentrations of glucose, alpha-cells secret glucagon which induces a rise in cAMP in beta-cells lodged in the same islet. A rise in cAMP itself does not activate the enzymes relevant to glycogenolysis, but merely prepares to activate the enzymes. When extracellular glucose increases, Ca2+ spikes are elicited. Influxed Ca2+ ions, together with cAMP, work

  14. The oral histone deacetylase inhibitor ITF2357 reduces cytokines and protects islet ß cells in vivo and in vitro

    DEFF Research Database (Denmark)

    Lewis, Eli C; Blaabjerg, Lykke; Størling, Joachim

    2011-01-01

    production and decreased apoptosis rates from 14.3% (vehicle) to 2.6% (ITF2357). Inducible nitric oxide synthase (iNOS) levels decreased in association with reduced islet-derived nitrite levels. In peritoneal macrophages and splenocytes, ITF2357 inhibited the production of nitrite, as well as that of TNFa...

  15. Evidence for Loss in Identity, De-Differentiation, and Trans-Differentiation of Islet β-Cells in Type 2 Diabetes.

    Science.gov (United States)

    Hunter, Chad S; Stein, Roland W

    2017-01-01

    The two main types of diabetes mellitus have distinct etiologies, yet a similar outcome: loss of islet β-cell function that is solely responsible for the secretion of the insulin hormone to reduce elevated plasma glucose toward euglycemic levels. Type 1 diabetes (T1D) has traditionally been characterized by autoimmune-mediated β-cell death leading to insulin-dependence, whereas type 2 diabetes (T2D) has hallmarks of peripheral insulin resistance, β-cell dysfunction, and cell death. However, a growing body of evidence suggests that, especially during T2D, key components of β-cell failure involves: (1) loss of cell identity, specifically proteins associated with mature cell function (e.g., insulin and transcription factors like MAFA, PDX1, and NKX6.1), as well as (2) de-differentiation, defined by regression to a progenitor or stem cell-like state. New technologies have allowed the field to compare islet cell characteristics from normal human donors to those under pathophysiological conditions by single cell RNA-Sequencing and through epigenetic analysis. This has revealed a remarkable level of heterogeneity among histologically defined "insulin-positive" β-cells. These results not only suggest that these β-cell subsets have different responses to insulin secretagogues, but that defining their unique gene expression and epigenetic modification profiles will offer opportunities to develop cellular therapeutics to enrich/maintain certain subsets for correcting pathological glucose levels. In this review, we will summarize the recent literature describing how β-cell heterogeneity and plasticity may be influenced in T2D, and various possible avenues of therapeutic intervention.

  16. Possible involvement of iNOS and TNF-α in nutritional intervention against nicotine-induced pancreatic islet cell damage.

    Science.gov (United States)

    Bhattacharjee, Ankita; Prasad, Shilpi Kumari; Pal, Swagata; Maji, Bithin; Banerjee, Arnab; Das, Debasmita; Bose, Ananya; Chatterjee, Nabanita; Mukherjee, Sandip

    2016-12-01

    Nicotine is the more abundant and most significant components of cigarette smoke. Epidemiological evidence strongly suggests an association between cigarette smoking and pancreatic injury. Although effects of smoking on endocrine pancreas are still controversial Here, we examined the impact and underlying mechanisms of action of folic acid and vitamin B12 on nicotine induced damage in pancreatic islets of rats. Male Wistar rats were treated with nicotine (3mg/kg body weight/day, intraperitonealy) with or without folic acid (36μg/kg body weight/day, orally) and vitamin B12 (0.63μg/kg body weight/day, orally) for 21days. Supplementation with folic acid and vitamin B12 suppressed the nicotine induced changes in HbA1c, insulin, TNF-α, IL-6, generation of reactive oxygen species, and attenuated the changes in markers of oxidative stress. Moreover, folic acid and vitamin B12 also counteracted the increased expression of protein and mRNA contents of TNF-α and iNOS produced by nicotine. Further, folic acid and vitamin B12 in combination limits the nicotine induced changes in cell cycle and excessive apoptosis of the pancreatic β-cells and also successfully blunted the nicotine induced alteration in loss of mitochondrial membrane potential. In conclusion, data demonstrate that folic acid and vitamin B12 may be possible nutritional intervention against cellular oxidative stress, which is a critical step in nicotine-mediated islet injury, and improves islet cell functional status by scavenging free radicals and by inhibiting the generation of pro-inflammatory mediators. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  17. Angiotensin II type 2 receptor is critical for the development of human fetal pancreatic progenitor cells into islet-like cell clusters and their potential for transplantation.

    Science.gov (United States)

    Leung, Kwan Keung; Liang, Juan; Ma, Man Ting; Leung, Po Sing

    2012-03-01

    Local renin-angiotensin systems (RASs) regulate the differentiation of tissue progenitors. However, it is not known whether such systems can regulate the development of pancreatic progenitor cells (PPCs). To address this issue, we characterized the expression profile of major RAS components in human fetal PPC preparations and examined their effects on the differentiation of PPCs into functional islet-like cell clusters (ICCs). We found that expression of RAS components was highly regulated throughout PPC differentiation and that locally generated angiotensin II (Ang II) maintained PPC growth and differentiation via Ang II type 1 and type 2 (AT(1) and AT(2)) receptors. In addition, we observed colocalization of AT(2) receptors with critical β-cell phenotype markers in PPCs/ICCs, as well as AT(2) receptor upregulation during differentiation, suggesting that these receptors may regulate β-cell development. In fact, we found that AT(2) , but not AT(1) , receptor was a key mediator of Ang II-induced upregulation of transcription factors important in β-cell development. Furthermore, lentivirus-mediated knockdown of AT(2) receptor suppressed the expression of these transcription factors in ICCs. Transplantation of AT(2) receptor-depleted ICCs into immune-privileged diabetic mice failed to ameliorate hyperglycemia, implying that AT(2) receptors are indispensable during ICC maturation in vivo. These data strongly indicate that a local RAS is involved in governing the functional maturation of pancreatic progenitors toward the endocrine lineage. Copyright © 2011 AlphaMed Press.

  18. Bone marrow augmentation of donor-cell chimerism in kidney, liver, heart, and pancreas islet transplantation

    Science.gov (United States)

    Fontes, Paulo; Rao, Abdul S; Demetris, Anthony J; Zeevi, Adriana; Trucco, Massimo; Carroll, Pat; Rybka, Witold; Rudert, William A; Ricordi, Camillo; Dodson, Forrest; Shapiro, Ron; Tzakis, Andreas; Todo, Satoru; Abu-Elmagd, Kareem; Jordan, Mark; Fung, John J

    2010-01-01

    Summary We have previously postulated that donor cell chimerism in organ transplantation is needed to attain a tolerant state. Here we show that donor cell chimerism can be augmented in organ recipients if they are infused perioperatively with 3 × 108 per kg of unmodified donor bone marrow cells and are kept on a conventional immunosuppressive regimen of tacrolimus (FK506) and prednisolone. 36 patients took part, of whom the first 18 patients have good transplanted kidney (n = 10), liver (n = 7), and heart (n = 7) function when followed up between 4 and 16 months. All patients are well. We found persistent multilineage leucocyte chimerism in blood of 17 recipients by flow cytometry and PCR techniques to detect donor alleles or Y chromosomes in female recipients of male organs. The use of the 5-antigen HLA matched same sex donor precluded detection of chimerism in one patient. PMID:7912764

  19. 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

    graft rejection alleviated. The immunological mechanisms of protection are mediated through deletion and induction of unresponsiveness in targeted memory T-cell populations. The data demonstrate that hematopoietic stem cell–mediated gene therapy effectively terminates antigen-specific memory T...

  20. Streptozotocin-induced diabetic ketoacidosis in a patient with metastatic islet-cell carcinoma

    NARCIS (Netherlands)

    Berends, M.; Lesterhuis, W. J.; van Laarhoven, H. W. M.

    2013-01-01

    Here we report a severe life-threatening complication of treatment with streptozotocin in a patient with pancreatic island-cell carcinoma. The patient was admitted to the intensive care unit with severe diabetic ketoacidosis which needed aggressive fluid resuscitation and insulin therapy. We believe

  1. Leptin signalling in pancreatic islets and clonal insulin-secreting cells

    NARCIS (Netherlands)

    Morton, N.M.; Emilsson, V.; Groot, R.P. de; Pallett, A.L.; Cawthorne, M.A.

    1999-01-01

    Leptin is a cytokine secreted from adipose tissue at a rate commensurate with the size of the body's fat stores. In addition to its anorectic and thermogenic central actions, leptin is known to act on peripheral tissues, including the pancreatic ß-cell where it inhibits insulin secretion and

  2. The flavanol (-)-epigallocatechin 3-gallate inhibits amyloid formation by islet amyloid polypeptide, disaggregates amyloid fibrils, and protects cultured cells against IAPP-induced toxicity.

    Science.gov (United States)

    Meng, Fanling; Abedini, Andisheh; Plesner, Annette; Verchere, C Bruce; Raleigh, Daniel P

    2010-09-21

    Islet amyloid polypeptide (IAPP, amylin) is the major protein component of the islet amyloid deposits associated with type 2 diabetes. The polypeptide lacks a well-defined structure in its monomeric state but readily assembles to form amyloid. Amyloid fibrils formed from IAPP, intermediates generated in the assembly of IAPP amyloid, or both are toxic to β-cells, suggesting that islet amyloid formation may contribute to the pathology of type 2 diabetes. There are relatively few reported inhibitors of amyloid formation by IAPP. Here we show that the tea-derived flavanol, (-)-epigallocatechin 3-gallate [(2R,3R)-5,7-dihydroxy-2-(3,4,5-trihydroxyphenyl)-3,4-dihydro-2H-1-benzopyran-3-yl 3,4,5-trihydroxybenzoate] (EGCG), is an effective inhibitor of in vitro IAPP amyloid formation and disaggregates preformed amyloid fibrils derived from IAPP. The compound is thus one of a very small set of molecules which have been shown to disaggregate IAPP amyloid fibrils. Fluorescence-detected thioflavin-T binding assays and transmission electron microscopy confirm that the compound inhibits unseeded amyloid fibril formation as well as disaggregates IAPP amyloid. Seeding studies show that the complex formed by IAPP and EGCG does not seed amyloid formation by IAPP. In this regard, the behavior of IAPP is similar to the reported interactions of Aβ and α-synuclein with EGCG. Alamar blue assays and light microscopy indicate that the compound protects cultured rat INS-1 cells against IAPP-induced toxicity. Thus, EGCG offers an interesting lead structure for further development of inhibitors of IAPP amyloid formation and compounds that disaggregate IAPP amyloid.

  3. Transdisciplinary approach to restore pancreatic islet function.

    Science.gov (United States)

    Fotino, Carmen; Molano, R Damaris; Ricordi, Camillo; Pileggi, Antonello

    2013-12-01

    The focus of our research is on islet immunobiology. We are exploring novel strategies that could be of assistance in the treatment and prevention of type 1 diabetes, as well as in the restoration of metabolic control via transplantation of insulin producing cells (i.e., islet cells). The multiple facets of diabetes and β-cell replacement encompass different complementary disciplines, such as immunology, cell biology, pharmacology, and bioengineering, among others. Through their interaction and integration, a transdisciplinary dimension is needed in order to address and overcome all aspects of the complex puzzle toward a successful clinical translation of a biological cure for diabetes.

  4. Pancreatic islet autotransplantation with total pancreatectomy for chronic pancreatitis.

    Science.gov (United States)

    Kuroki, Tamotsu; Adachi, Tomohiko; Ono, Shinichiro; Tanaka, Takayuki; Kitasato, Amane; Eguchi, Susumu

    2013-07-01

    Achieving pain relief and improving the quality of life are the main targets of treatment for patients with chronic pancreatitis. The use of total pancreatectomy to treat chronic pancreatitis is a radical and in some ways ideal strategy. However, total pancreatectomy is associated with severe diabetic control problems. Total pancreatectomy with islet autotransplantation can relieve severe pain and prevent the development of postsurgical diabetes. With islet autotransplantation, patients with chronic pancreatitis receive their own islet cells and therefore do not require immunosuppressive therapy. In the future, total pancreatectomy with islet autotransplantation may be considered a treatment option for chronic pancreatitis patients.

  5. Transplantation sites for human and murine islets.

    Science.gov (United States)

    Stokes, Rebecca A; Cheng, Kim; Lalwani, Amit; Swarbrick, Michael M; Thomas, Helen E; Loudovaris, Thomas; Kay, Tom W; Hawthorne, Wayne J; O'Connell, Philip J; Gunton, Jenny E

    2017-10-01

    Beta cell replacement is a potential cure for type 1 diabetes. In humans, islet transplants are currently infused into the liver via the portal vein, although this site has disadvantages. Here, we investigated alternative transplantation sites for human and murine islets in recipient mice, comparing the portal vein with quadriceps muscle and kidney, liver and spleen capsules. Murine islets were isolated from C57BL6/J mice and transplanted into syngeneic recipients. Human islets were isolated and transplanted into either severe combined immunodeficiency (SCID) or recombination-activating gene 1 (RAG-1) immunodeficient recipient mice. All recipient mice were 8-12 weeks of age and had been rendered diabetic (defined as blood glucose concentrations ≥20 mmol/l on two consecutive days before transplantation) by alloxan tetrahydrate treatment. Islets were transplanted into five different sites (portal vein, quadriceps muscle, kidney, liver and spleen capsules). Blood glucose concentrations were monitored twice weekly until mice were killed. Dose-response studies were also performed to determine the minimum number of islets required to cure diabetes ('cure' is defined for this study as random fed blood glucose of <15 mmol/l). For transplantation of murine islets into the different sites, the kidney yielded 100% success, followed by muscle (70%), portal vein (60%), spleen capsule (29%) and liver capsule (0%). For human islets, transplantation into the kidney cured diabetes in 75-80% of recipient mice. Transplantation into muscle and portal vein had intermediate success (both 29% at 2000 islet equivalents), while transplantation into liver and spleen capsule failed (0%). With increased islet mass, success rates for muscle grafts improved to 52-56%. For both human and murine islets, equivalent or superior glucose lowering results were obtained for transplantation into skeletal muscle, compared with the portal vein. Unfortunately, kidney grafts are not feasible in human

  6. [Thyroid Adenomas in Children].

    Science.gov (United States)

    Morozov, D A; Pimenova, E S; Mirokova, E D

    2015-01-01

    According to the papers thyroid nodules are quite rare in the first two decades of life. However, there are some exceptions, relating to areas with an iodine deficiency or affected by radioactive fallout, where the risk of nodules and carcinomas is increased. Therefore, it is a great challenge for the physician to distinguish between benign and malignant lesions preoperatively, and not only in these areas of greater risk. The authors analyzed current works, which are devoted to diagnostics and treatment of adenomas of thyroid gland in children. This literature review is based on works dedicated to epidemiology, histotypes study, and methods of diagnostics, surgical treatment, prognosis and complications of this pathology. The current tendencies in surgical approaches, intraoperative monitoring of recurrent laryngeal nerve are also discussed. The actuality of this problem is connected with last decade increase of adenomas in structure of thyroid gland nodules, increase of number of patients with multiple adenomas and with polypathias: adenomas with nodular goiter, autoimmune thyroiditis and cancer in children. The difficulties of diagnostic of adenomas are related to the similar clinical symptoms, cytogenetic characteristics of growth of benign and malignant lesions of thyroid gland. Additionally there is no systematic review about thyroid adenomas in children recent years.

  7. Immunohistochemical analysis of pituitary adenomas in a West ...

    African Journals Online (AJOL)

    There were no thyrotroph adenomas. Conclusion: The lower incidence of prolactinomas in this study may be due to the use of other therapeutic modes rather than surgical treatment but may also indicate racial differences. However there is a need for further characterization of the null cell adenomas using ultrastructural and ...

  8. Altered islet morphology but normal islet secretory function in vitro in a mouse model with microvascular alterations in the pancreas.

    Directory of Open Access Journals (Sweden)

    Elena Kostromina

    Full Text Available BACKGROUND: Our previous studies have shown that signal transducer and activator of transcription 3 (STAT3 signaling is important for the development of pancreatic microvasculature via its regulation of vascular endothelial growth factor-A (VEGF-A. Pancreas-specific STAT3-KO mice exhibit glucose intolerance and impaired insulin secretion in vivo, along with microvascular alterations in the pancreas. However, the specific role of STAT3 signaling in the regulation of pancreatic islet development and function is not entirely understood. METHODOLOGY/PRINCIPAL FINDINGS: To investigate the role of STAT3 signaling in the formation and maintenance of pancreatic islets, we studied pancreas-specific STAT3-KO mice. Histological analysis showed that STAT3 deficiency affected pancreatic islet morphology. We found an increased proportion of small-sized islets and a reduced fraction of medium-sized islets, indicating abnormal islet development in STAT3-KO mice. Interestingly, the islet area relative to the whole pancreas area in transgenic and control mice was not significantly different. Immunohistochemical analysis on pancreatic cryosections revealed abnormalities in islet architecture in STAT3-KO mice: the pattern of peripheral distribution of glucagon-positive α-cells was altered. At the same time, islets belonging to different size categories isolated from STAT3-KO mice exhibited normal glucose-stimulated insulin secretion in perifusion experiments in vitro when compared to control mice. CONCLUSIONS: Our data demonstrate that STAT3 signaling in the pancreas is required for normal islet formation and/or maintenance. Altered islet size distribution in the KO mice does not result in an impaired islet secretory function in vitro. Therefore, our current study supports that the glucose intolerance and in vivo insulin secretion defect in pancreas-specific STAT3-KO mice is due to altered microvasculature in the pancreas, and not intrinsic beta-cell function.

  9. A possible role of transglutaminase 2 in the nucleus of INS-1E and of cells of human pancreatic islets.

    Science.gov (United States)

    Sileno, Sara; D'Oria, Valentina; Stucchi, Riccardo; Alessio, Massimo; Petrini, Stefania; Bonetto, Valentina; Maechler, Pierre; Bertuzzi, Federico; Grasso, Valeria; Paolella, Katia; Barbetti, Fabrizio; Massa, Ornella

    2014-01-16

    Transglutaminase 2 (TG2) is a multifunctional protein with Ca(2+)-dependent transamidating and G protein activity. Previously we reported that the role of TG2 in insulin secretion may involve cytoplasmic actin remodeling and a regulative action on other proteins during granule movement. The aim of this study was to gain a better insight into the role of TG2 transamidating activity in mitochondria and in the nucleus of INS-1E rat insulinoma cell line (INS-1E) during insulin secretion. To this end we labeled INS-1E with an artificial donor (biotinylated peptide), in basal condition and after stimulus with glucose for 2, 5, and 8min. Biotinylated proteins of the nuclear/mitochondrial-enriched fraction were analyzed using two-dimensional electrophoresis and mass spectrometry. Many mitochondrial proteins involved in Ca(2+) homeostasis (e.g. voltage-dependent anion-selective channel protein, prohibitin and different ATP synthase subunits) and many nuclear proteins involved in gene regulation (e.g. histone H3, barrier to autointegration factor and various heterogeneous nuclear ribonucleoprotein) were identified among a number of transamidating substrates of TG2 in INS-1E. The combined results provide evidence that a temporal link exists between glucose-stimulation, first phase insulin secretion and the action of TG on histone H3 both in INS-1E and human pancreatic islets. Research into the role of transglutaminase 2 during insulin secretion in INS-1E rat insulinoma cellular model is depicting a complex role for this enzyme. Transglutaminase 2 acts in the different INS-1E compartments in the same way: catalyzing a post-translational modification event of its substrates. In this work we identify some mitochondrial and nuclear substrates of INS-1E during first phase insulin secretion. The finding that TG2 interacts with nuclear proteins that include BAF and histone H3 immediately after (2-5min) glucose stimulus of INS-1E suggests that TG2 may be involved not only in insulin

  10. Islet xenograft destruction in the hu-PBL-severe combined immunodeficient (SCID) mouse necessitates anti-CD3 preactivation of human immune cells

    Science.gov (United States)

    Gysemans, C; Waer, M; Laureys, J; Depovere, J; Pipeleers, D; Bouillon, R; Mathieu, C

    2000-01-01

    Introduction of the hu-PBL-SCID mouse model has yielded a potentially useful tool for research in transplantation. The aim of this study was to define the conditions necessary for a reconstituted human immune system to destroy in a consistent manner rat islet xenografts in the alloxan-diabetic hu-PBL-SCID mouse. We examined different time points of hu-PBL reconstitution, different transplantation sites of the islets and several hu-PBL reconstitution protocols. Major differences in graft destruction were observed between the different hu-PBL reconstitution protocols, irrespective of timing of hu-PBL reconstitution or site of transplantation. Although preactivation of hu-PBL did not improve the level of hu-PBL chimerism, histological and immunohistochemical analysis of the grafts revealed a severe human lymphocytic infiltration and β cell destruction only in the grafts of mice receiving preactivated hu-PBL. This β cell injury resulted in impaired glucose tolerance, with in some animals recurrence of hyperglycaemia, and decreased insulin and C-peptide levels after glucose stimulation. Therefore, we conclude that activation of hu-PBL prior to transfer is essential in achieving xenograft infiltration and destruction in hu-PBL-SCID mice. The need for immune manipulation suggests that interactions between hu-PBL and xenografts in this model may be hampered by incompatibilities in cross-species adhesion and/or activation signals. PMID:10971525

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

    Directory of Open Access Journals (Sweden)

    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.

  12. Genetically Engineered Human Islets Protected From CD8-mediated Autoimmune Destruction In Vivo

    NARCIS (Netherlands)

    Zaldumbide, Arnaud; Alkemade, Gonnie; Carlotti, Francoise; Nikolic, Tatjana; Abreu, Joana R. F.; Engelse, Marten A.; Skowera, Anja; de Koning, Eelco J.; Peakman, Mark; Roep, Bart O.; Hoeben, Rob C.; Wiertz, Emmanuel J. H. J.

    Islet transplantation is a promising therapy for type 1 diabetes, but graft function and survival are compromised by recurrent islet autoimmunity. Immunoprotection of islets will be required to improve clinical outcome. We engineered human beta cells to express herpesvirus-encoded immune-evasion

  13. Technique of endoscopic biopsy of islet allografts transplanted into the gastric submucosal space in pigs

    NARCIS (Netherlands)

    T. Fujita (Tetsuji); K.M. McGrath (Kevin); R. Bottino (Rita); E.M. Dons (Eefje); C. Long (Cassandra); G. Kumar (Goutham); B. Ekser; G.J. Echeverri (Gabriel); A. Hata (Akira); K. Haruma (Ken); D.K.C. Cooper (David); H. Hara (Hidetaka)

    2013-01-01

    textabstractCurrently, islet cells are transplanted into the liver via portal vein infusion. One disadvantage of this approach is that it is not possible to adequately biopsy the islets in the liver to assess for rejection. Islet transplantation (Tx) into the gastric submucosal space (GSMS) can be

  14. Light bodies in human pituitary adenomas

    DEFF Research Database (Denmark)

    Holck, S; Wewer, U M; Albrechtsen, R

    1987-01-01

    Light bodies are large cytoplasmic granules originally described in the gonadotrophic cells of the rat pituitary gland. In order to determine whether similar bodies occur in the human anterior pituitary gland, 89 pituitary adenomas and periadenomatous tissue from 20 cases were examined...... cells in periadenomatous tissue from 20 cases. These results show that some human pituitary adenomas may contain light bodies identical to those seen in gonadotrophs of rat pituitary....... by transmission electron microscopy. Double membrane bound bodies with filamentous internal structure identical to rodent light bodies were identified in 10 hormone-producing adenomas: 5 PRL, 1 PRL-GH, 2 GH, and 2 ACTH-producing tumours. No light bodies were found in the remaining 79 tumours nor in the pituitary...

  15. Approaches for imaging islets: recent advances and future prospects.

    NARCIS (Netherlands)

    Ahlgren, U.; Gotthardt, M.

    2010-01-01

    The establishment of improved technologies for imaging of the pancreas is a key element in addressing several aspects of diabetes pathogenesis. In this respect, the development of a protocol that allows for non-invasive scoring of human islets, or islet beta-cells, is of particular importance. The

  16. Islet Amyloid Polypeptide: Structure, Function, and Pathophysiology

    Directory of Open Access Journals (Sweden)

    Rehana Akter

    2016-01-01

    Full Text Available The hormone islet amyloid polypeptide (IAPP, or amylin plays a role in glucose homeostasis but aggregates to form islet amyloid in type-2 diabetes. Islet amyloid formation contributes to β-cell dysfunction and death in the disease and to the failure of islet transplants. Recent work suggests a role for IAPP aggregation in cardiovascular complications of type-2 diabetes and hints at a possible role in type-1 diabetes. The mechanisms of IAPP amyloid formation in vivo or in vitro are not understood and the mechanisms of IAPP induced β-cell death are not fully defined. Activation of the inflammasome, defects in autophagy, ER stress, generation of reactive oxygen species, membrane disruption, and receptor mediated mechanisms have all been proposed to play a role. Open questions in the field include the relative importance of the various mechanisms of β-cell death, the relevance of reductionist biophysical studies to the situation in vivo, the molecular mechanism of amyloid formation in vitro and in vivo, the factors which trigger amyloid formation in type-2 diabetes, the potential role of IAPP in type-1 diabetes, the development of clinically relevant inhibitors of islet amyloidosis toxicity, and the design of soluble, bioactive variants of IAPP for use as adjuncts to insulin therapy.

  17. Effect of Over 10-Year Cryopreserved Encapsulated Pancreatic Islets Of Langerhans.

    Science.gov (United States)

    Kinasiewicz, Joanna; Antosiak-Iwanska, Magdalena; Godlewska, Ewa; Sitarek, Elzbieta; Sabat, Marek; Fiedor, Piotr; Granicka, Ludomira

    2017-08-28

    Immunoisolation of pancreatic islets of Langerhans performed by the encapsulation process may be a method to avoid immunosuppressive therapy after transplant. The main problem related to islet transplant is shortage of human pancreata. Resolution of this obstacle may be cryopreservation of encapsulated islets, which enables collection of sufficient numbers of isolated islets required for transplant and long-term storage. Here, we assessed the ability of encapsulated islets to function after long-term banking at low temperature. Islets of Langerhans isolated from rat, pig, and human pancreata were encapsulated within alginate-poly-L-lysine-alginate microcapsules. Cryopreservation was carried out using a controlled method of freezing (Kriomedpol freezer; Kriomedpol, Warsaw, Poland), and samples were stored in liquid nitrogen. After 10 years, the samples were thawed with the rapid method (with 0.75 M of sucrose) and then cultured. We observed that microcapsules containing islets maintained their shape and integrity after thawing. During culture, free islets were defragmented into single cells, whereas encapsulated islets were still round in shape and compact. After 1, 4, and 7 days of culture of encapsulated islets, the use of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide tests showed increased mitochondrial activity. After they were thawed, the insulin secretion capacity was comparable with that obtained with fresh islets. Cryopreservation and storage of free and microencapsulated islets were possible for about 10 years, although only encapsulated islets retained viability and secretory properties.

  18. Gap junction coupling and calcium waves in the pancreatic islet.

    Science.gov (United States)

    Benninger, Richard K P; Zhang, Min; Head, W Steven; Satin, Leslie S; Piston, David W

    2008-12-01

    The pancreatic islet is a highly coupled, multicellular system that exhibits complex spatiotemporal electrical activity in response to elevated glucose levels. The emergent properties of islets, which differ from those arising in isolated islet cells, are believed to arise in part by gap junctional coupling, but the mechanisms through which this coupling occurs are poorly understood. To uncover these mechanisms, we have used both high-speed imaging and theoretical modeling of the electrical activity in pancreatic islets under a reduction in the gap junction mediated electrical coupling. Utilizing islets from a gap junction protein connexin 36 knockout mouse model together with chemical inhibitors, we can modulate the electrical coupling in the islet in a precise manner and quantify this modulation by electrophysiology measurements. We find that after a reduction in electrical coupling, calcium waves are slowed as well as disrupted, and the number of cells showing synchronous calcium oscillations is reduced. This behavior can be reproduced by computational modeling of a heterogeneous population of beta-cells with heterogeneous levels of electrical coupling. The resulting quantitative agreement between the data and analytical models of islet connectivity, using only a single free parameter, reveals the mechanistic underpinnings of the multicellular behavior of the islet.

  19. Mammary analogue secretory carcinoma mimicking salivary adenoma.

    Science.gov (United States)

    Williams, Lindsay; Chiosea, Simion I

    2013-12-01

    Mammary analogue secretory carcinoma (MASC) is a recently described salivary gland tumor characterized by ETV6 translocation. It appears that prior studies have identified MASC by reviewing salivary gland carcinomas, such as acinic cell carcinoma and adenocarcinoma, not otherwise specified. To address the possibility of MASC mimicking benign salivary neoplasms we reviewed 12 salivary gland (cyst)adenomas diagnosed prior to the discovery of MASC. One encapsulated (cyst)adenoma of the parotid gland demonstrated features of MASC. The diagnosis was confirmed by fluorescence in situ hybridization with an ETV6 break-apart probe. An unusual complex pattern of ETV6 rearrangement with duplication of the telomeric/distal ETV6 probe was identified. This case illustrates that MASC may mimic salivary (cyst)adenomas. To more accurately assess true clinical and morphologic spectrum of MASC, future studies may have to include review of salivary (cyst)adenomas. The differential diagnosis of MASC may have to be expanded to include cases resembling salivary (cyst)adenomas.

  20. Contemporary issues in the evaluation and management of pituitary adenomas.

    Science.gov (United States)

    Pekic, S; Stojanovic, M; Popovic, V

    2015-12-01

    Pituitary adenomas are common benign monoclonal neoplasms accounting for about 15% of intracranial neoplasms. Data from postmortem studies and imaging studies suggest that 1 of 5 individuals in the general population may have pituitary adenoma. Some pituitary adenomas (mainly microadenomas which have a diameter of less than 1 cm) are exceedingly common and are incidentally diagnosed on magnetic resonance imaging (MRI) performed for an unrelated reason (headache, vertigo, head trauma). Most microadenomas remain clinically occult and stable in size, without an increase in tumor cells and without local mass effects. However, some pituitary adenomas grow slowly, enlarge by expansion and become demarcated from normal pituitary (macroadenomas have a diameter greater than 1 cm). They may be clinically silent or secrete anterior pituitary hormones in excess such as prolactin, growth hormone (GH), or adrenocorticotropic hormone (ACTH) causing diseases like prolactinoma, acromegaly, Cushing's disease or rarely thyroid-stimulating hormone (TSH) or gonadotropins (LH, FSH). The incidence of the various subtypes of pituitary adenoma varies but the most common is prolactinoma. Clinically non-functioning pituitary adenomas (NFPAs), which do not secrete hormones often cause local mass symptoms and represent one-third of pituitary adenomas. Given the high prevalence of pituitary adenomas and their heterogeneity (different tumor subtypes), it is critical that clinicians have a thorough understanding of the potential abnormalities in pituitary function and prognostic factors for behavior of pituitary adenomas in order to timely implement specific treatment modalities. Regarding pathogenesis of these tumors genetics, epigenetics and signaling pathways are the focus of current research yet our understanding of pituitary tumorigenesis remains incomplete. Although several genes and signaling pathways have been identified as important factors in the development of pituitary tumors, current

  1. A novel strategy for the development of selective active-site inhibitors of the protein tyrosine phosphatase-like proteins islet-cell antigen 512 (IA-2) and phogrin (IA-2 beta)

    DEFF Research Database (Denmark)

    Drake, P.G.; Peters, Günther H.j.; Andersen, H.S.

    2003-01-01

    Islet-cell antigen 512 (IA-2) and phogrin (IA-2) are atypical members of he receptor protein tyrosine phosphatase (PTP) family that are characterized by a lack of activity against conventional PTP substrates. The physiological role(s) of these proteins remain poorly defined, although recent studi...

  2. Islet organogenesis, angiogenesis and innervation.

    Science.gov (United States)

    Cerf, Marlon E

    2011-11-01

    The pancreas is characterized by a major component, an exocrine and ductal system involved in digestion, and a minor component, the endocrine islets represented by islet micro-organs that tightly regulate glucose homoeostasis. Pancreatic organogenesis is strictly co-ordinated by transcription factors that are expressed sequentially to yield functional islets capable of maintaining glucose homoeostasis. Angiogenesis and innervation complete islet development, equipping islets to respond to metabolic demands. Proper regulation of this triad of processes during development is critical for establishing functional islets.

  3. Achievement of insulin independence in three consecutive type-1 diabetic patients via pancreatic islet transplantation using islets isolated at a remote islet isolation center.

    Science.gov (United States)

    Goss, John A; Schock, Angela P; Brunicardi, F Charles; Goodpastor, Sarah E; Garber, Alan J; Soltes, George; Barth, Merle; Froud, Tatiana; Alejandro, Rodolfo; Ricordi, Camillo

    2002-12-27

    As a result of advances in both immunosuppressive protocols and pancreatic islet isolation techniques, insulin independence has recently been achieved in several patients with type 1 diabetes mellitus via pancreatic islet transplantation (PIT). Although the dissemination of immunosuppressive protocols is quite easy, transferring the knowledge and expertise required to isolate a large number of quality human islets for transplantation is a far greater challenge. Therefore, in an attempt to centralize the critical islet processing needed for islet transplantation and to avoid the development of another islet processing center, we have established a collaborative islet transplant program between two geographically distant transplant centers. Three consecutive patients with type 1 diabetes mellitus with a history of severe hypoglycemia and metabolic instability underwent PIT at the Methodist Hospital (TMH), Houston, Texas, using pancreatic islets. All pancreatic islets were isolated from pancreata procured in Houston and subsequently transported for isolation to the Human Islet Cell Processing Facility of the Diabetes Research Institute (DRI) at the University of Miami, Miami, Florida. Pancreatic islets were isolated at DRI after enzymatic ductal perfusion (Liberase-HI) by the automated method (Ricordi Chamber) using endotoxin-free and xenoprotein-free media. After purification, the islets were immediately transported back to TMH and transplanted via percutaneous transhepatic portal embolization. Immunosuppression consisted of sirolimus, tacrolimus, and daclizumab. After donor cross-clamp in Houston, donor pancreata arrived at DRI and the isolation process began within 6.5 hr in all cases (median, 5.4 hr; range, 4.8-6.5 hr). At the completion of the isolation process, the islets were immediately transported back to TMH and transplanted. All three patients attained sustained insulin independence after transplantation of 395,567, 394,381, and 563,206 pancreatic islet

  4. Pancreatic islet cell tumor

    Science.gov (United States)

    ... Feeling tired or weak Shaking or sweating Headache Hunger Nervousness, anxiety, or feeling irritable Unclear thinking or ... reduce symptoms. Support Groups You can ease the stress of illness by joining a cancer support group . ...

  5. Pleomorphic adenoma of the palate

    Directory of Open Access Journals (Sweden)

    Prathima Shetty

    2015-01-01

    Full Text Available Pleomorphic adenoma is a benign salivary gland tumor commonly affecting in the major salivary glands. Incidence of pleomorphic adenoma affecting minor salivary gland tumors has also been reported. Presenting a case report of a 48-year-old male diagnosed with pleomorphic adenoma arising from minor salivary gland.

  6. Synchronous Quadruple Primary Neoplasms: Colon Adenocarcinoma, Collision Tumor of Neuroendocrine Tumor and Schwann Cell Hamartoma and Sessile Serrated Adenoma of the Appendix.

    Science.gov (United States)

    Meeks, Marshall W; Grace, Shane; Chen, Yongxin; Petterchak, James; Bolesta, Edward; Zhou, Yihua; Lai, Jin-Ping

    2016-08-01

    Quadruple synchronous primary neoplasms are very rare with only three cases reported in the English-speaking literature to date. Collision tumors are also rare entities, especially of the appendix. We herein report a case of synchronous quadruple primary neoplasm in a 95-year-old female. She was diagnosed with colon adenocarcinoma, sessile serrated adenoma of the appendix and a collision tumor composed of a well-differentiated neuroendocrine tumor and Schwann cell hamartoma. Histological examination and immunohistochemistry supported these four lesions as separate entities. This case is unique because we report the diagnosis of quadruple synchronous primary, an extremely rare occurrence, in addition to a collision tumor of the appendix. We also provide a review of the literature for synchronous neoplasms and collision tumors. Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  7. Real-time, multidimensional in vivo imaging used to investigate blood flow in mouse pancreatic islets.

    Science.gov (United States)

    Nyman, Lara R; Wells, K Sam; Head, W Steve; McCaughey, Michael; Ford, Eric; Brissova, Marcela; Piston, David W; Powers, Alvin C

    2008-11-01

    The pancreatic islets of Langerhans are highly vascularized micro-organs that play a key role in the regulation of blood glucose homeostasis. The specific arrangement of endocrine cell types in islets suggests a coupling between morphology and function within the islet. Here, we established a line-scanning confocal microscopy approach to examine the relationship between blood flow and islet cell type arrangement by real-time in vivo imaging of intra-islet blood flow in mice. These data were used to reconstruct the in vivo 3D architecture of the islet and time-resolved blood flow patterns throughout the islet vascular bed. The results revealed 2 predominant blood flow patterns in mouse islets: inner-to-outer, in which blood perfuses the core of beta cells before the islet perimeter of non-beta cells, and top-to-bottom, in which blood perfuses the islet from one side to the other regardless of cell type. Our approach included both millisecond temporal resolution and submicron spatial resolution, allowing for real-time imaging of islet blood flow within the living mouse, which has not to our knowledge been attainable by other methods.

  8. Progression to type 1 diabetes in islet cell antibody-positive relatives in the European Nicotinamide Diabetes Intervention Trial

    DEFF Research Database (Denmark)

    Bingley, P J; Gale, E A M; Reimers, Jesper Irving

    2006-01-01

    ), protein tyrosine phosphatase (IA-2A) and insulin (IAA) were determined by RIA, and HLA class II genotyping was performed by PCR of sequence-specific oligonucleotides. RESULTS: One hundred and fifty-nine participants developed diabetes within 5 years. Univariate analysis showed that the cumulative risk...... of development of diabetes within 5 years varied according to age, relationship to the proband, positivity for IAA, IA-2A and GADA, number and combination of islet antibodies, HLA class II genotype, baseline glucose tolerance, and first-phase insulin secretion, but not gender or incidence of childhood type 1...

  9. Augmented β-Cell Function and Mass in Glucocorticoid-Treated Rodents Are Associated with Increased Islet Ir-β/AKT/mTOR and Decreased AMPK/ACC and AS160 Signaling

    Directory of Open Access Journals (Sweden)

    André O. P. Protzek

    2014-01-01

    Full Text Available Glucocorticoid (GC therapies may adversely cause insulin resistance (IR that lead to a compensatory hyperinsulinemia due to insulin hypersecretion. The increased β-cell function is associated with increased insulin signaling that has the protein kinase B (AKT substrate with 160 kDa (AS160 as an important downstream AKT effector. In muscle, both insulin and AMP-activated protein kinase (AMPK signaling phosphorylate and inactivate AS160, which favors the glucose transporter (GLUT-4 translocation to plasma membrane. Whether AS160 phosphorylation is modulated in islets from GC-treated subjects is unknown. For this, two animal models, Swiss mice and Wistar rats, were treated with dexamethasone (DEX (1 mg/kg body weight for 5 consecutive days. DEX treatment induced IR, hyperinsulinemia, and dyslipidemia in both species, but glucose intolerance and hyperglycemia only in rats. DEX treatment caused increased insulin secretion in response to glucose and augmented β-cell mass in both species that were associated with increased islet content and increased phosphorylation of the AS160 protein. Protein AKT phosphorylation, but not AMPK phosphorylation, was found significantly enhanced in islets from DEX-treated animals. We conclude that the augmented β-cell function developed in response to the GC-induced IR involves inhibition of the islet AS160 protein activity.

  10. Detection of Intrahepatic Human Islets Following Combined Liver-Islet Allotransplantation

    Science.gov (United States)

    Ricordi, Camillo; Tzakis, Andreas; Alejandro, Rodolfo; Zeng, Yijun; Demetris, Anthony J.; Carroll, Patricia; Fung, John J.; Mintz, Daniel H.; Starzl, Thomas E.

    2010-01-01

    Summary This article describes the localization of intact insulin-containing intrahepatic islets after combined liver-islet allotransplantation. The patient was a 36-year-old woman who underwent upper abdominal exenteration for neuroendocrine carcinoma; 289,000 islets were transplanted via portal vein infusion immediately after complete revascularization of the liver. Immunosuppression was with low-dose FK-506. OKT3 and steroids were used to treat one rejection episode 2 weeks after transplantation, but the patient subsequently developed multiple infections and died 109 days after transplantation. At autopsy, the transplanted liver did not show any sign of rejection and well-preserved islets were present in portal triads sampled from the anterior inferior edge of the right lobe. Immunohistochemical labeling confirmed the presence of insulin-containing cells. This finding indicated that human islets can survive after intrahepatic allotransplantation, despite positive cross-match with no HLA antigen match, suggesting that upper abdominal exenteration and liver transplantation may constitute a protective factor for the survival of allogeneic human islets. PMID:1641394

  11. Mitochondrial glycerol-3-phosphate dehydrogenase. Cloning of an alternatively spliced human islet-cell cDNA, tissue distribution, physical mapping, and identification of a polymorphic genetic marker.

    Science.gov (United States)

    Ferrer, J; Aoki, M; Behn, P; Nestorowicz, A; Riggs, A; Permutt, M A

    1996-02-01

    Pancreatic beta-cell mitochondrial glycerol-3-phosphate dehydrogenase (mGPDH) plays a major role in glucose-induced insulin secretion. Decreased activity of this enzyme has thus been proposed to play a role in the pathogenesis of NIDDM. Cloning of human insulinoma mGPDH cDNAs disclosed the existence of two variant transcripts with different 5' ends. Reverse transcription polymerase chain reaction (PCR) confirmed the presence of both mGPDH mRNAs in purified native human pancreatic islets and other tissues. A major 6.5-Kb mGPDH transcript was detected by Northern blot analysis in RNA from human and rat pancreatic islets, with distinctly lower levels in other human tissues, indicating that previously reported high mGPDH enzymatic activity in beta-cells is determined by high transcript levels. The mGPDH gene was mapped to chromosome 2 by PCR analysis of genomic DNA from human/rodent somatic cell hybrids, and five independent overlapping yeast artificial chromosome (YAC) clones containing the mGPDH sequence were identified from the Centre d'Etude du Polymorphisme Humain YAC library. Analysis of these YAC clones identified a highly polymorphic chromosome 2q21-q33 dinucleotide repeat genetic marker (D2S141) physically linked to the mGPDH gene. These studies provide the means to investigate the role of the human mGPDH gene in the pathogenesis of NIDDM and illustrate the value of a novel strategy to identify genetic markers for diabetes candidate genes.

  12. Islet Microencapsulation: Strategies and Clinical Status in Diabetes.

    Science.gov (United States)

    Omami, Mustafa; McGarrigle, James J; Reedy, Mick; Isa, Douglas; Ghani, Sofia; Marchese, Enza; Bochenek, Matthew A; Longi, Maha; Xing, Yuan; Joshi, Ira; Wang, Yong; Oberholzer, José

    2017-07-01

    Type 1 diabetes mellitus (T1DM) is an autoimmune disease that results from the destruction of insulin-producing pancreatic β cells in the islets of Langerhans. Islet cell transplantation has become a successful therapy for specific patients with T1DM with hypoglycemic unawareness. The reversal of T1DM by islet transplantation is now performed at many major medical facilities throughout the world. However, many challenges must still be overcome in order to achieve continuous, long-term successful transplant outcomes. Two major obstacles to this therapy are a lack of islet cells for transplantation and the need for life-long immunosuppressive treatment. Microencapsulation is seen as a technology that can overcome both these limitations of islet cell transplantation. This review depicts the present state of microencapsulated islet transplantation. Microencapsulation can play a significant role in overcoming the need for immunosuppression and lack of donor islet cells. This review focuses on microencapsulation and the clinical status of the technology in combating T1DM.

  13. Curcumin treatment enhances islet recovery by induction of heat shock response proteins, Hsp70 and heme oxygenase-1, during cryopreservation.

    Science.gov (United States)

    Kanitkar, Meghana; Bhonde, Ramesh R

    2008-01-16

    Limited recovery of islets post-cryopreservation influences graft survival and transplantation efficiency during diabetes treatment. As curcumin, a potent antioxidant/radical scavenging compound, protects islets against beta cell toxins, we hypothesized that inclusion of curcumin during cryopreservation or during post-thaw culture or both may rescue islets from cryoinjury. To test the effect of curcumin inclusion on islet recovery murine islets were isolated by the collagenase digestion, cultured for 48 h, cryopreserved using dimethylsulphoxide as cryoprotectant -- with or without curcumin (10 microM) -- and then slow cooled to -40 degrees C before immersing them in liquid nitrogen for 7 days. Following rapid thawing with sucrose gradient and 24 h post-thaw culture -- in presence or absence of curcumin (10 microM) -- islet viability and functionality were determined. Islet recovery in curcumin treated groups was significantly higher than in groups where islets were cryopreserved without curcumin. Islets cryopreserved with curcumin also showed more intact islets as well as better morphology as compared to islets cryopreserved without curcumin. Curcumin treated islets also showed significant inhibition of ROS generation as compared to islets cryopreserved without curcumin. Glucose responsiveness and insulin secretion in islets cryopreserved with curcumin was equal to that of the freshly isolated islets as against islets cryopreserved without curcumin. Elevated level of Hsp 70 and HO-1 were observed in islets cryopreserved with curcumin and may contribute to curcumin-induced islet rescue. Hence, we conclude that inclusion of curcumin into cryopreservation medium inhibits ROS generation and corresponding islet damage and dysfunction.

  14. Differentiation of human skin-derived precursor cells into functional islet-like insulin-producing cell clusters

    DEFF Research Database (Denmark)

    Mehrabi, Maryam; Mansouri, Kamran; Hosseinkhani, Saman

    2015-01-01

    Advances in cell-replacement strategies for diabetes have focused on renewable sources of glucose-responsive, insulin-producing cells (IPCs). One of the most proper alternatives is multipotent skin-derived precursors cells (SKPs), which can be differentiated into IPCs. In this study, we reported...... the isolation and expansion of human skin-derived precursors (hSKPs) followed by their differentiation into IPCs in vitro, through exposure to suitable differentiation factors. The gene expression of endocrine β cell markers was analyzed by reverse transcriptase-polymerase chain reaction. In addition, insulin......-dependent manner. These findings suggest that human SKPs can differentiate into functional IPCs. This may offer a safer cell source for future stem cell-based therapies....

  15. Rescue purification maximizes the use of human islet preparations for transplantation.

    Science.gov (United States)

    Ichii, Hirohito; Pileggi, Antonello; Molano, R Damaris; Baidal, David A; Khan, Aisha; Kuroda, Yoshikazu; Inverardi, Luca; Goss, John A; Alejandro, Rodolfo; Ricordi, Camillo

    2005-01-01

    The relative inefficiency of the islet purification process may hamper obtaining enough islets for transplantation even with adequate pre-purification counts. In this study, we determined the effect of an additional purification step on total islet yields and pancreas utilization at our center. Twenty-five pancreata were processed using the automated method followed by continuous gradient purification (CGP), and the less pure islet fractions were subjected to additional rescue gradient purification (RGP). CGP and RGP islets were combined and transplanted into patients with type 1 diabetes. CGP and RGP islets showed no significant differences in cell viability, insulin secretion in vitro and function when transplanted into chemically diabetic mice. Mean RGP contribution to the final preparation was 27.9 +/- 19.9%. In 12 of 25 preparations, CGP yielded <5000 IEQ/kg of recipient body weight, and inclusion of RGP islets to the final preparation allowed to obtain the minimal islet number required for transplantation. Transplanted islets resulted in sustained C-peptide production, HbA1(C) normalization and insulin-independence or reduced insulin requirements. Taken together, our data suggest that RGP islets are comparable in terms of viability and potency to CGP islets. RGP may be of assistance in maximizing the number of islet preparations successfully used in transplant protocols.

  16. Induction of Protective Genes Leads to Islet Survival and Function

    Directory of Open Access Journals (Sweden)

    Hongjun Wang

    2011-01-01

    Full Text Available Islet transplantation is the most valid approach to the treatment of type 1 diabetes. However, the function of transplanted islets is often compromised since a large number of β cells undergo apoptosis induced by stress and the immune rejection response elicited by the recipient after transplantation. Conventional treatment for islet transplantation is to administer immunosuppressive drugs to the recipient to suppress the immune rejection response mounted against transplanted islets. Induction of protective genes in the recipient (e.g., heme oxygenase-1 (HO-1, A20/tumor necrosis factor alpha inducible protein3 (tnfaip3, biliverdin reductase (BVR, Bcl2, and others or administration of one or more of the products of HO-1 to the donor, the islets themselves, and/or the recipient offers an alternative or synergistic approach to improve islet graft survival and function. In this perspective, we summarize studies describing the protective effects of these genes on islet survival and function in rodent allogeneic and xenogeneic transplantation models and the prevention of onset of diabetes, with emphasis on HO-1, A20, and BVR. Such approaches are also appealing to islet autotransplantation in patients with chronic pancreatitis after total pancreatectomy, a procedure that currently only leads to 1/3 of transplanted patients being diabetes-free.

  17. Insulin requirement in non-insulin-dependent diabetes mellitus: relation to simple tests of islet B-cell function and insulin sensitivity

    DEFF Research Database (Denmark)

    Gjessing, H J; Matzen, L E; Pedersen, P C

    1988-01-01

    Evaluation of simple tests of islet B-cell function and insulin sensitivity as predictors of metabolic control was performed during 3 months of insulin withdrawal in 25 insulin-treated diabetic subjects. All patients had a glucagon stimulated plasma C-peptide concentration above 0.33 nmol....../l and a fasting plasma C-peptide concentration above 0.20 nmol/l a few days before insulin withdrawal. Insulin sensitivity was measured as the glucose disappearance rate (k) during an intravenous insulin tolerance test. Two patients were considered insulin-requiring due to high fasting blood glucose levels......-peptide levels the predictive value of a positive test was 100% while the predictive value of a negative test was as low as 33% or 27% depending on whether fasting or stimulated C-peptide concentration was used. Including the k value in the prediction only increased the predictive values of negative tests to 40...

  18. Functional implications of long non-coding RNAs in the pancreatic islets of Langerhans

    Directory of Open Access Journals (Sweden)

    Lena eEliasson

    2014-07-01

    Full Text Available Type-2 diabetes (T2D is a complex disease characterized by insulin resistance in target tissues and impaired insulin release from pancreatic beta cells. As central tissue of glucose homeostasis, the pancreatic islet continues to be an important focus of research to understand the pathophysiology of the disease. The increased access to human pancreatic islets has resulted in improved knowledge of islet function, and together with advances in RNA sequencing and related technologies, revealed the transcriptional and epigenetic landscape of human islet cells. The discovery of thousands of long non-coding RNA (lncRNA transcripts highly enriched in the pancreatic islet and/or specifically-expressed in the beta-cells, points to yet another layer of gene regulation of many hitherto unknown mechanistic principles governing islet cell functions. Here we review fundamental islet physiology and propose functional implications of the lncRNAs in islet development and endocrine cell functions. We also take into account important differences between rodent and human islets in terms of morphology and function, and suggest how species-specific lncRNAs may partly influence gene regulation to define the unique phenotypic identity of an organism and the functions of its constituent cells. The implication of primate-specific lncRNAs in diabetes will be far-reaching in all aspects of diabetes research, but most importantly in the identification and development of novel targets to improve pancreatic islet cell functions as a therapeutic approach to treat T2D.

  19. Immunoisolation of Murine Islet Allografts in Vascularized Sites Through Conformal Coating with Polyethylene Glycol.

    Science.gov (United States)

    Manzoli, Vita; Villa, Chiara; Bayer, Allison L; Morales, Laura; Molano, R Damaris; Torrente, Yvan; Ricordi, Camillo; Hubbell, Jeffrey A; Tomei, Alice A

    2017-10-25

    Islet encapsulation may allow transplantation without immunosuppression but thus far islets in large microcapsules transplanted in the peritoneal cavity failed to reverse diabetes in humans. We showed that islet transplantation in confined well-vascularized sites like the epididymal fat pad (EFP) improved graft outcomes, but only conformal coated (CC) islets can be implanted in these sites in curative doses. Here, we showed that CC using polyethylene glycol (PEG) and alginate (ALG) was not immunoisolating because of its high permselectivity and strong allogeneic T cell responses. We refined the CC composition and explored PEG and islet-like extracellular matrix (MG) islet encapsulation (PEG MG) to improve capsule immunoisolation by decreasing its permselectivity and immunogenicity while allowing physiological islet function. Though diabetes reversal efficiency of allogeneic but not syngeneic CC islets was lower than naked islets, we showed that CC (PEG MG) islets from fully MHC-mismatched Balb/c mice supported long-term (> 100 days) survival after transplantation into diabetic C57BL/6 recipients in the EFP site (750-1000 IEQ / mouse) in absence of immunosuppression. Lack of immune cell penetration and T cell allogeneic priming was observed. These studies support the use of CC (PEG MG) for islet encapsulation and transplantation in clinically-relevant sites without chronic immunosuppression. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  20. Growth hormone receptor expression and function in pituitary adenomas

    DEFF Research Database (Denmark)

    Clausen, Lene R; Kristiansen, Mikkel T; Rasmussen, Lars M

    2004-01-01

    OBJECTIVE AND DESIGN: Hypopituitarism, in particular GH deficiency, is prevalent in patients with clinically nonfunctioning pituitary adenomas (NFPAs) both before and after surgery. The factors regulating the growth of pituitary adenomas in general and residual tumour tissue in particular....... CONCLUSION: GH receptors are expressed in human pituitary adenoma cells but their functional role is uncertain. GH and IGF-I do not consistently influence the proliferation of cultured pituitary adenoma cells....... are not fully characterized, and the effect of GH and IGF-I on human pituitary cell proliferation has not previously been reported. In NFPA tissue from 14 patients we evaluated GH receptor (GHR) expression and signal transduction, and the effect of GH and IGF-I exposure on cell proliferation and hormone...

  1. Ultrastructural studies of time-course and cellular specificity of interleukin-1 mediated islet cytotoxicity

    DEFF Research Database (Denmark)

    Mandrup-Poulsen, T; Egeberg, J; Nerup, J

    1987-01-01

    Previous electron-microscopic studies of isolated islets of Langerhans exposed to the monokine interleukin-1 for 7 days have indicated that interleukin-1 is cytotoxic to all islet cells. To study the time-course and possible cellular specificity of interleukin-1 cytotoxicity to islets exposed...... to interleukin-1 for short time periods, isolated rat or human islets were incubated with or without 25 U/ml highly purified human interleukin-1 for 24 h. Samples of rat islets were taken after 5 min, 30 min, 1, 2, 4, 6, 8, 10, 12, 16, 20 and 24 h and samples of human islets after 5 min, 30 min and 24 h...... of incubation and examined by electron microscopy in a blinded fashion. Already after 30 min, accumulation of opaque intracytoplasmic bodies without apparent surrounding membranes, and autophagic vacuoles were seen in about 20% of the beta cells examined in rat islets exposed to interleukin-1. After 16 h...

  2. 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

  3. Matrix metalloproteinase-13 expression in the progression of colorectal adenoma to carcinoma : Matrix metalloproteinase-13 expression in the colorectal adenoma and carcinoma.

    Science.gov (United States)

    Foda, Abd Al-Rahman Mohammad; El-Hawary, Amira K; Abdel-Aziz, Azza

    2014-06-01

    Most colorectal carcinomas (CRCs) are considered to arise from conventional adenoma based on the concept of the adenoma-carcinoma sequence. Matrix metalloproteinases (MMPs) are known to be overexpressed as normal mucosa progresses to adenomas and carcinomas. There has been little previous investigation about MMP-13 expression in adenoma-carcinoma sequence. In this study, we aimed to investigate the immunohistochemical expression of MMP-13 in colorectal adenoma and CRC specimens using tissue microarray (TMA) technique. A total of 40 cases of CRC associated with adenoma were collected from files of the Pathology laboratory at Mansoura Gastroenterology Center between January 2007 and January 2012. Sections from TMA blocks were prepared and stained for MMP-13. Immunoreactivity to MMP-13 staining was localized to the cytoplasm of mildly, moderately, and severely dysplatic cells of adenomas and CRC tumor cells that were either homogenous or heterogeneous. There was no significant difference in MMP-13 expression between adenomas and CRCs either non-mucinous or mucinous. Adenomas with high MMP-13 expression were significantly associated with moderate to marked degree of inflammatory cellular infiltrate and presence of familial adenomatous polyps. In conclusion, MMP-13 may be a potential biological marker of early tumorigenesis in the adenoma-carcinoma sequence.

  4. Magnetic resonance imaging of pituitary adenoma

    Energy Technology Data Exchange (ETDEWEB)

    Handa, Yuji; Hayashi, Minoru; Kubota, Toshihiko; Satoh, Kazufumi; Kobayashi, Hidenori; Kawano, Hirokazu; Kabuto, Masanori; Okumura, Ryousuke

    1988-04-01

    The magnetic resonance (MR) images of eight patients with pituitary macroadenoma, confirmed by means of CT, were evaluated retrospectively. The examinations were performed with a 0.35 T MR system using short repetition (TR) (T/sub 1/-weighted) and long TR (T/sub 2/-weighted) spin-echo sequences. T/sub 1/-weighted images were obtained on coronal, sagittal, or axial planes with all patients, while T/sub 2/-weighted images were routinely obtained on the axial plane with all patients and on the sagittal or coronal plane in some cases. Detailed information as to the size, configuration, and anatomical relationship, particularly to the optic tract, of the pituitary adenoma were well visualized on sagittal or coronal T/sub 1/-weighted images. The signal intensities from the tumor on T/sub 1/-weighted of T/sub 2/-weighted images were evaluated as iso-, hypo- or hyper-intense with respect to the cortical gray matter. The signal intensities from three non-functioning pituitary adenomas varied from low- to high-intense on the T/sub 1/- or T/sub 2/-weighted images. All the two growth-hormone-producing adenomas showed iso-intense signal intensities on both T/sub 1/- and T/sub 2/-weighted images. One of the two prolactine-producing adenomas were iso-intense on a T/sub 1/-weighted image and low-intense on a T/sub 2/-weighted image, while the other adenoma, when treated with bromocriptine, was iso-intense on both T/sub 1/- and T/sub 2/-weighted images. One adenocorticotropic hormone-producing adenoma was iso-intense on T/sub 1/-weighted and high-intense on T/sub 2/-weighted images. Although the signal intensities on the images, particularly the T/sub 2/-weighted images, were variable, regardless of the type of adenoma, it is presumed that the MR signal arising from a pituitary adenoma affected by the biological or pathological state of the tumor cells.

  5. Intrinsic islet heterogeneity and gap junction coupling determine spatiotemporal Ca²⁺ wave dynamics.

    Science.gov (United States)

    Benninger, Richard K P; Hutchens, Troy; Head, W Steven; McCaughey, Michael J; Zhang, Min; Le Marchand, Sylvain J; Satin, Leslie S; Piston, David W

    2014-12-02

    Insulin is released from the islets of Langerhans in discrete pulses that are linked to synchronized oscillations of intracellular free calcium ([Ca(2+)]i). Associated with each synchronized oscillation is a propagating calcium wave mediated by Connexin36 (Cx36) gap junctions. A computational islet model predicted that waves emerge due to heterogeneity in β-cell function throughout the islet. To test this, we applied defined patterns of glucose stimulation across the islet using a microfluidic device and measured how these perturbations affect calcium wave propagation. We further investigated how gap junction coupling regulates spatiotemporal [Ca(2+)]i dynamics in the face of heterogeneous glucose stimulation. Calcium waves were found to originate in regions of the islet having elevated excitability, and this heterogeneity is an intrinsic property of islet β-cells. The extent of [Ca(2+)]i elevation across the islet in the presence of heterogeneity is gap-junction dependent, which reveals a glucose dependence of gap junction coupling. To better describe these observations, we had to modify the computational islet model to consider the electrochemical gradient between neighboring β-cells. These results reveal how the spatiotemporal [Ca(2+)]i dynamics of the islet depend on β-cell heterogeneity and cell-cell coupling, and are important for understanding the regulation of coordinated insulin release across the islet. Copyright © 2014 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  6. Intrinsic Islet Heterogeneity and Gap Junction Coupling Determine Spatiotemporal Ca2+ Wave Dynamics

    Science.gov (United States)

    Benninger, Richard K.P.; Hutchens, Troy; Head, W. Steven; McCaughey, Michael J.; Zhang, Min; Le Marchand, Sylvain J.; Satin, Leslie S.; Piston, David W.

    2014-01-01

    Insulin is released from the islets of Langerhans in discrete pulses that are linked to synchronized oscillations of intracellular free calcium ([Ca2+]i). Associated with each synchronized oscillation is a propagating calcium wave mediated by Connexin36 (Cx36) gap junctions. A computational islet model predicted that waves emerge due to heterogeneity in β-cell function throughout the islet. To test this, we applied defined patterns of glucose stimulation across the islet using a microfluidic device and measured how these perturbations affect calcium wave propagation. We further investigated how gap junction coupling regulates spatiotemporal [Ca2+]i dynamics in the face of heterogeneous glucose stimulation. Calcium waves were found to originate in regions of the islet having elevated excitability, and this heterogeneity is an intrinsic property of islet β-cells. The extent of [Ca2+]i elevation across the islet in the presence of heterogeneity is gap-junction dependent, which reveals a glucose dependence of gap junction coupling. To better describe these observations, we had to modify the computational islet model to consider the electrochemical gradient between neighboring β-cells. These results reveal how the spatiotemporal [Ca2+]i dynamics of the islet depend on β-cell heterogeneity and cell-cell coupling, and are important for understanding the regulation of coordinated insulin release across the islet. PMID:25468351

  7. Regulation of Pancreatic Islet Gene Expression in Mouse Islets by Pregnancy

    DEFF Research Database (Denmark)

    Layden, Brian Thomas; Durai, Vivek; Newman, Marsha V

    2010-01-01

    Pancreatic beta cells adapt to pregnancy-induced insulin resistance by unclear mechanisms. This study sought to identify genes involved in beta cell adaptation during pregnancy. To examine changes in global RNA expression during pregnancy, murine islets were isolated at a time point of increased...... beta cell proliferation (E13.5), and RNA levels were determined by 2 different assays (global gene expression array and G protein-coupled receptor array). Follow-up studies confirmed the findings for select genes. Differential expression of 110 genes was identified and follow-up studies confirmed...... the changes in select genes at both the RNA and protein level. Surfactant protein D mRNA and protein levels exhibited large increases which were confirmed in murine islets. Cytokine-induced expression of surfactant protein D in islets was also demonstrated, suggesting a possible role as an anti...

  8. Engineering biomimetic materials for islet transplantation.

    Science.gov (United States)

    Yang, Ethan Y; Kronenfeld, Joshua P; Stabler, Cherie L

    2015-01-01

    A closed-loop system that provides both the sensing of glucose and the appropriate dosage of insulin could dramatically improve treatment options for insulin-dependent diabetics. The intrahepatic implantation of allogeneic islets has the potential to provide this intimate control, by transplanting the very cells that have this inherent sensing and secretion capacity. Limiting islet transplantation, however, is the significant loss and dysfunction of islets following implantation, due to the poor engraftment environment and significant immunological attack. In this review, we outline approaches that seek to address these challenges via engineering biomimetic materials. These materials can serve to mimic natural processes that work toward improving engraftment, minimizing inflammation, and directing immunological responses. Biomimetic materials can serve to house cells, recapitulate native microenvironments, release therapeutic agents in a physiological manner, and/or present agents to direct cells towards desired responses. By integrating these approaches, superior platforms capable of improving long-term engraftment and acceptance of transplanted islets are on the horizon.

  9. PD-L1 Deficiency within Islets Reduces Allograft Survival in Mice.

    Directory of Open Access Journals (Sweden)

    Dongxia Ma

    Full Text Available Islet transplantation may potentially cure type 1 diabetes mellitus (T1DM. However, immune rejection, especially that induced by the alloreactive T-cell response, remains a restraining factor for the long-term survival of grafted islets. Programmed death ligand-1 (PD-L1 is a negative costimulatory molecule. PD-L1 deficiency within the donor heart accelerates allograft rejection. Here, we investigate whether PD-L1 deficiency in donor islets reduces allograft survival time.Glucose Stimulation Assays were performed to evaluate whether PD-L1 deficiency has detrimental effects on islet function. Islets isolated from PDL1-deficient mice or wild- type (WT mice (C57BL/6j were implanted beneath the renal capsule of streptozotocin (STZ-induced diabetic BALB/c mice. Blood glucose levels and graft survival time after transplantation were monitored. Moreover, we analyzed the residual islets, infiltrating immune cells and alloreactive cells from the recipients.PD-L1 deficiency within islets does not affect islet function. However, islet PD-L1 deficiency increased allograft rejection and was associated with enhanced inflammatory cell infiltration and recipient T-cell alloreactivity.This is the first report to demonstrate that PD-L1 deficiency accelerated islet allograft rejection and regulated recipient alloimmune responses.

  10. Hydrogel encapsulation environments functionalized with extracellular matrix interactions increase islet insulin secretion

    Science.gov (United States)

    Weber, Laney M.; Anseth, Kristi S.

    2009-01-01

    The individual and synergistic effects of extracellular matrix interactions on isolated islet function in culture were investigated within a three-dimensional poly(ethylene glycol) (PEG) hydrogel encapsulation environment. First, we observed similar glucose-stimulated insulin secretion from unencapsulated murine islets and islets photoencapsulated in PEG gels. Then islets were encapsulated in gels containing the basement membrane proteins collagen type IV and laminin, individually and in combination, at a total protein concentration of 100 μg/ml, and islet insulin secretion in response to high glucose was measured over time. Specific laminin interactions were investigated via islet encapsulation with adhesive peptide sequences found in laminin as well as via functional blocking of cell surface receptors known to bind laminin. Over 32 days, islet interactions with collagen type IV and laminin localized within the three-dimensional extracellular environment contributed to two-fold and four-fold increases in insulin secretion, respectively, relative to islets encapsulated without matrix proteins. Hydrogel compositions containing both matrix proteins and > 75% laminin further increased islet insulin secretion to approximately six-fold that of islets encapsulated in the absence of matrix proteins. Encapsulation with the peptide sequence IKVAV resulted in increased islet insulin secretion, but not to the extent observed in the presence of whole laminin. Increased insulin secretion in the presence of laminin was eliminated when islets were exposed to functionally blocking anti-α6 integrin antibody prior to islet encapsulation with laminin. Our results demonstrate the potential of specific matrix interactions within an islet encapsulation microenvironment to promote encapsulated islet function. PMID:18773957

  11. Simple numerical chromosome aberrations in two pituitary adenomas

    DEFF Research Database (Denmark)

    Dietrich, C U; Pandis, N; Bjerre, P

    1993-01-01

    -secreting adenoma, three aberrant clones were detected, giving the karyotype 45,X, -Y[20]/47,XY, +Y[6]/45,XY, -21[3]/46,XY[21]. One cell had the chromosome complement 46,X, -Y, +9; no other nonclonal aberrations were detected. The only hitherto published case of pituitary adenoma analyzed by banding techniques (Rey...... et al. [1986]: Cancer Genet Cytogenet 23:171-174) also had only numerical clonal changes that included extra copies of chromosome 9. We conclude that pituitary adenomas may be karyotypically characterized by numerical aberrations and that trisomy 9 seems to be the best candidate for a primary...

  12. Renal Adenomas: Pathological Differential Diagnosis with Malignant Tumors

    Directory of Open Access Journals (Sweden)

    F. Algaba

    2008-01-01

    Full Text Available The renal adenomas can be confused by imaging diagnosis with malignant renal tumors, but there are also real biological dilemmas to determine their behavior. The consensus decisions are the following. (1 The adenoma of clear cells is not accepted, instead it is considered that all the clear-cell tumors are carcinomas, with greater or lesser aggressiveness. (2 Among the papillary neoplasms the WHO 2004 renal cell tumors classification are considered as papillary adenomas tumors with a maximum diameter of 5 mm and may represent a continuum biological process to papillary renal cell carcinoma. The papillary adenomas associated with End-kidney and/or acquired cystic disease may have a different pathogenesis. (3 To consider a tumor as an oncocytoma the size is not important, only the cytological features, microscopic, ultrastructural, and immunohistochemically can help, but some chromosomal observations introduce some questions about its relation with the chromophobe renal cell carcinoma. (4 Finally, the metanephric adenoma, a tumor with some morphological similarity with the nephroblastoma must be considered in the renal adenomas diagnosis.

  13. 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

    Directory of Open Access Journals (Sweden)

    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.

  14. Current Status of Immunomodulatory and Cellular Therapies in Preclinical and Clinical Islet Transplantation

    Directory of Open Access Journals (Sweden)

    Preeti Chhabra

    2011-01-01

    Full Text Available Clinical islet transplantation is a -cell replacement strategy that represents a possible definitive intervention for patients with type 1 diabetes, offering substantial benefits in terms of lowering daily insulin requirements and reducing incidences of debilitating hypoglycemic episodes and unawareness. Despite impressive advances in this field, a limiting supply of islets, inadequate means for preventing islet rejection, and the deleterious diabetogenic and nephrotoxic side effects associated with chronic immunosuppressive therapy preclude its wide-spread applicability. Islet transplantation however allows a window of opportunity for attempting various therapeutic manipulations of islets prior to transplantation aimed at achieving superior transplant outcomes. In this paper, we will focus on the current status of various immunosuppressive and cellular therapies that promote graft function and survival in preclinical and clinical islet transplantation with special emphasis on the tolerance-inducing capacity of regulatory T cells as well as the -cells regenerative capacity of stem cells.

  15. Regional differences in islet distribution in the human pancreas--preferential beta-cell loss in the head region in patients with type 2 diabetes.

    Directory of Open Access Journals (Sweden)

    Xiaojun Wang

    Full Text Available While regional heterogeneity in islet distribution has been well studied in rodents, less is known about human pancreatic histology. To fill gaps in our understanding, regional differences in the adult human pancreas were quantitatively analyzed including the pathogenesis of type 2 diabetes (T2D. Cadaveric pancreas specimens were collected from the head, body and tail regions of each donor, including subjects with no history of diabetes or pancreatic diseases (n = 23 as well as patients with T2D (n = 12. The study further included individuals from whom islets were isolated (n = 7 to study islet yield and function in a clinical setting of islet transplantation. The whole pancreatic sections were examined using an innovative large-scale image capture and unbiased detailed quantitative analyses of the characteristics of islets from each individual (architecture, size, shape and distribution. Islet distribution/density is similar between the head and body regions, but is >2-fold higher in the tail region. In contrast to rodents, islet cellular composition and architecture were similar throughout the pancreas and there was no difference in glucose-stimulated insulin secretion in islets isolated from different regions of the pancreas. Further studies revealed preferential loss of large islets in the head region in patients with T2D. The present study has demonstrated distinct characteristics of the human pancreas, which should provide a baseline for the future studies integrating existing research in the field and helping to advance bi-directional research between humans and preclinical models.

  16. PI3K/Akt/mTOR pathway involvement in regulating growth hormone secretion in a rat pituitary adenoma cell line.

    Science.gov (United States)

    Di Pasquale, Carmelina; Gentilin, Erica; Falletta, Simona; Bellio, Mariaenrica; Buratto, Mattia; Degli Uberti, Ettore; Chiara Zatelli, Maria

    2017-10-27

    Insulin-like growth factor 1 (IGF1) controls growth hormone (GH) secretion via a negative feed-back loop that may disclose novel mechanisms possibly useful to control GH hyper-secretion. Our aim was to understand whether PI3K/Akt/mTOR pathway is involved in IGF1 negative feedback on GH secretion. Cell viability, GH secretion, Akt, and Erk 1/2 phosphorylation levels in the rat GH3 cell line were assessed under treatment with IGF1 and/or everolimus, an mTOR inhitior. We found that IGF1 improves rat GH3 somatotroph cell viability via the PI3K/Akt/mTOR pathway and confirmed that IGF1 exerts a negative feedback on GH secretion by a transcriptional mechanism. We demonstrated that the negative IGF1 loop on GH secretion requires Akt activation that seems to play a pivotal role in the control of GH secretion. Furthermore, Akt activation is independent of PI3K and probably mediated by mTORC2. In addition, we found that Erk 1/2 is not involved in GH3 cell viability regulation, but may have a role in controlling GH secretion, independently of IGF1. Our data confirm that mTOR inhibitors may be useful to reduce pituitary adenoma cell viability, while Erk 1/2 pathway may be considered as a useful therapeutic target to control GH secretion. Our results open the field for further studies searching for effective drugs to control GH hyper-secretion.

  17. Glucagon-like peptide 1 receptor agonist ameliorates the insulin resistance function of islet β cells via the activation of PDX-1/JAK signaling transduction in C57/BL6 mice with high-fat diet-induced diabetes.

    Science.gov (United States)

    Hao, Tao; Zhang, Hongtao; Li, Sheyu; Tian, Haoming

    2017-04-01

    Long-term exposure to a high-fat diet (HFD) causes glucotoxicity and lipotoxicity in islet β cells and leads to the development of metabolic dysfunctions. Reductions in pancreatic and duodenal homeobox-1 (PDX-1) expression have been shown to induce type 2 diabetes mellitus by causing impairments to islet β cells. Glucagon-like peptide 1 (GLP-1) treatment reduces endogenous insulin resistance in HFD-induced type 2 diabetes mellitus. In the present study, the underlying mechanism by which GLP-1 exerts its function in type 2 diabetes mellitus was investigated. The effect of liraglutide (GLP-1 receptor agonist) administration on glucose tolerance, insulin release, and glucose-dependent insulinotropic polypeptide level was detected in a HFD-induced diabetes C57/BL6 mouse model. Moreover, the role of liraglutide administration on the activity of PDX-1 was quantified to demonstrate the association between the two indicators. The results showed that administration of liraglutide could ameliorate the impairments to β cells due to HFD consumption. Liraglutide restored the insulin capacity and stimulated glucose disposal by improving the function and increasing the number of islet β cells. Furthermore, the hyperplasia and redundant function of islet α cells were inhibited by liraglutide treatment as well. At the molecular level, administration of liraglutide induced the expression of PDX-1, MafA, p-JAK2 and p-Stat3 in HFD model to relatively normal levels. It was suggested that the effect of liraglutide-induced activation of GLP-1 was exerted via activation of PDX-1 rather than its function in decreasing body weight. The study demonstrated that GLP-1 played an essential role in type 2 diabetes mellitus.

  18. Quantum dots labelling allows detection of the homing of mesenchymal stem cells administered as immunomodulatory therapy in an experimental model of pancreatic islets transplantation.

    Science.gov (United States)

    Mannucci, Silvia; Calderan, Laura; Quaranta, Paola; Antonini, Sara; Mosca, Franco; Longoni, Biancamaria; Marzola, Pasquina; Boschi, Federico

    2017-03-01

    Cell transplantation is considered a promising therapeutic approach in several pathologies but still needs innovative and non-invasive imaging technologies to be validated. The use of mesenchymal stem cells (MSCs) attracts major interest in clinical transplantation thanks to their regenerative properties, low immunogenicity and ability to regulate immune responses. In several animal models, MSCs are used in co-transplantation with pancreatic islets (PIs) for the treatment of type I diabetes, supporting graft survival and prolonging normal glycaemia levels. In this study we investigated the homing of systemically administered MSCs in a rat model of pancreatic portal vein transplantation. MSCs labelled with quantum dots (Qdots) were systemically injected by tail vein and monitored by optical fluorescence imaging. The fluorescence signal of the liver in animals co-transplanted with MSCs and PIs was significantly higher than in control animals in which MSCs alone were transplanted. By using magnetic labelling of PIs, the homing of PIs into liver was independently confirmed. These results demonstrate that MSCs injected in peripheral blood vessels preferentially accumulate into liver when PIs are transplanted in the same organ. Moreover, we prove that bimodal MRI-fluorescence imaging allows specific monitoring of the fate of two types of cells. © 2016 Anatomical Society.

  19. The Spleen Is an Ideal Site for Inducing Transplanted Islet Graft Expansion in Mice.

    Directory of Open Access Journals (Sweden)

    Takeshi Itoh

    Full Text Available Alternative islet transplantation sites have the potential to reduce the marginal number of islets required to ameliorate hyperglycemia in recipients with diabetes. Previously, we reported that T cell leukemia homeobox 1 (Tlx1+ stem cells in the spleen effectively regenerated into insulin-producing cells in the pancreas of non-obese diabetic mice with end-stage disease. Thus, we investigated the spleen as a potential alternative islet transplantation site. Streptozotocin-induced diabetic C57BL/6 mice received syngeneic islets into the portal vein (PV, beneath the kidney capsule (KC, or into the spleen (SP. The marginal number of islets by PV, KC, or SP was 200, 100, and 50, respectively. Some plasma inflammatory cytokine levels in the SP group were significantly lower than those of the PV group after receiving a marginal number of islets, indicating reduced inflammation in the SP group. Insulin contents were increased 280 days after islet transplantation compared with those immediately following transplantation (p<0.05. Additionally, Tlx1-related genes, including Rrm2b and Pla2g2d, were up-regulated, which indicates that islet grafts expanded in the spleen. The spleen is an ideal candidate for an alternative islet transplantation site because of the resulting reduced inflammation and expansion of the islet graft.

  20. PARACRINE AND AUTOCRINE INTERACTIONS IN THE HUMAN ISLET: MORE THAN MEETS THE EYE

    Science.gov (United States)

    Caicedo, Alejandro

    2012-01-01

    The pancreatic islet secretes the hormones insulin and glucagon to regulate glucose metabolism. To generate an adequate secretory response, islet endocrine cells must receive multiple regulatory signals relaying information about changes in the internal and external environments. Islet cells also need to be made aware about the functional status of neighboring cells through paracrine interactions. All this information is used to orchestrate a hormonal response that contributes to glucose homeostasis. Several neurotransmitters have been proposed to work as paracrine signals in the islet. Most of these, however, have yet to meet the criteria to be considered bona fide paracrine signals, in particular in human islets. Here, we review recent findings describing autocrine and paracrine signaling mechanisms in human islets. These recent results are showing an increasingly complex picture of paracrine interactions in the human islet and emphasize that results from other species cannot be readily extrapolated to the human context. Investigators are unveiling new signaling mechanisms or finding new roles for known paracrine signals in human islets. While it is too early to provide a synthesis, the field of islet research is defining the paracrine and autocrine components that will be used to generate models about how islet function is regulated. Meanwhile, the identified signaling pathways can be proposed as therapeutic targets for treating diabetes, a devastating disease affecting millions worldwide. PMID:23022232

  1. Lacrimal Gland Pleomorphic Adenoma and Carcinoma ex Pleomorphic Adenoma

    DEFF Research Database (Denmark)

    von Holstein, Sarah L; Fehr, André; Persson, Marta

    2014-01-01

    To study genetic alterations in lacrimal gland pleomorphic adenoma (PA) and carcinoma ex pleomorphic adenoma (Ca-ex-PA) with focus on copy number changes and expression patterns of the translocation target genes PLAG1, HMGA2, and CRTC1-MAML2 in relation to clinical data....

  2. Has the gap between pancreas and islet transplantation closed?

    Science.gov (United States)

    Niclauss, Nadja; Morel, Philippe; Berney, Thierry

    2014-09-27

    Both pancreas and islet transplantations are therapeutic options for complicated type 1 diabetes. Until recent years, outcomes of islet transplantation have been significantly inferior to those of whole pancreas. Islet transplantation is primarily performed alone in patients with severe hypoglycemia, and recent registry reports have suggested that results of islet transplantation alone in this indication may be about to match those of pancreas transplant alone in insulin independence. Figures of 50% insulin independence at 5 years for either procedure have been cited. In this article, we address the question whether islet transplantation has indeed bridged the gap with whole pancreas. Looking at the evidence to answer this question, we propose that although pancreas may still be more efficient in taking recipients off insulin than islets, there are in fact numerous "gaps" separating both procedures that must be taken into the equation. These "gaps" relate to organ utilization, organ allocation, indication for transplantation, and morbidity. In-depth analysis reveals that islet transplantation, in fact, has an edge on whole pancreas in some of these aspects. Accordingly, attempts should be made to bridge these gaps from both sides to achieve the same level of success with either procedure. More realistically, it is likely that some of these gaps will remain and that both procedures will coexist and complement each other, to ensure that β cell replacement can be successfully implemented in the greatest possible number of patients with type 1 diabetes.

  3. Glucose metabolism, islet architecture, and genetic homogeneity in imprinting of [Ca2+](i and insulin rhythms in mouse islets.

    Directory of Open Access Journals (Sweden)

    Craig S Nunemaker

    2009-12-01

    Full Text Available We reported previously that islets isolated from individual, outbred Swiss-Webster mice displayed oscillations in intracellular calcium ([Ca2+](i that varied little between islets of a single mouse but considerably between mice, a phenomenon we termed "islet imprinting." We have now confirmed and extended these findings in several respects. First, imprinting occurs in both inbred (C57BL/6J as well as outbred mouse strains (Swiss-Webster; CD1. Second, imprinting was observed in NAD(PH oscillations, indicating a metabolic component. Further, short-term exposure to a glucose-free solution, which transiently silenced [Ca2+](i oscillations, reset the oscillatory patterns to a higher frequency. This suggests a key role for glucose metabolism in maintaining imprinting, as transiently suppressing the oscillations with diazoxide, a K(ATP-channel opener that blocks [Ca2+](i influx downstream of glucose metabolism, did not change the imprinted patterns. Third, imprinting was not as readily observed at the level of single beta cells, as the [Ca2+](i oscillations of single cells isolated from imprinted islets exhibited highly variable, and typically slower [Ca2+](i oscillations. Lastly, to test whether the imprinted [Ca2+](i patterns were of functional significance, a novel microchip platform was used to monitor insulin release from multiple islets in real time. Insulin release patterns correlated closely with [Ca2+](i oscillations and showed significant mouse-to-mouse differences, indicating imprinting. These results indicate that islet imprinting is a general feature of islets and is likely to be of physiological significance. While islet imprinting did not depend on the genetic background of the mice, glucose metabolism and intact islet architecture may be important for the imprinting phenomenon.

  4. In vivo and ex vivo 19-fluorine magnetic resonance imaging and spectroscopy of beta-cells and pancreatic islets using GLUT-2 specific contrast agents.

    Science.gov (United States)

    Liang, Sayuan; Louchami, Karim; Kolster, Hauke; Jacobsen, Anna; Zhang, Ying; Thimm, Julian; Sener, Abdullah; Thiem, Joachim; Malaisse, Willy; Dresselaers, Tom; Himmelreich, Uwe

    2016-11-01

    The assessment of the β-cell mass in experimental models of diabetes and ultimately in patients is a hallmark to understand the relationship between reduced β-cell mass/function and the onset of diabetes. It has been shown before that the GLUT-2 transporter is highly expressed in both β-cells and hepatocytes and that D-mannoheptulose (DMH) has high uptake specificity for the GLUT-2 transporter. As 19-fluorine MRI has emerged as a new alternative method for MRI cell tracking because it provides potential non-invasive localization and quantification of labeled cells, the purpose of this project is to validate β-cell and pancreatic islet imaging by using fluorinated, GLUT-2 targeting mannoheptulose derivatives ( 19 FMH) both in vivo and ex vivo. In this study, we confirmed that, similar to DMH, 19 FMHs inhibit insulin secretion and increase the blood glucose level in mice temporarily (approximately two hours). We were able to assess the distribution of 19 FMHs in vivo with a temporal resolution of about 20 minutes, which showed a quick removal of 19 FMH from the circulation (within two hours). Ex vivo MR spectroscopy confirmed a preferential uptake of 19 FMH in tissue with high expression of the GLUT-2 transporter, such as liver, endocrine pancreas and kidney. No indication of further metabolism was found. In summary, 19 FMHs are potentially suitable for visualizing and tracking of GLUT-2 expressed cells. However, current bottlenecks of this technique related to the quick clearance of the compound and relative low sensitivity of 19 F MRI need to be overcome. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  5. Important role of heparan sulfate in postnatal islet growth and insulin secretion

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Iwao; Noguchi, Naoya [Department of Advanced Biological Sciences for Regeneration (Kotobiken Medical Laboratories), Tohoku University Graduate School of Medicine, Sendai 980-8575 (Japan); Nata, Koji [Department of Medical Biochemistry, Iwate Medical University School of Pharmacy, Yahaba-cho 028-3603 (Japan); Yamada, Shuhei; Kaneiwa, Tomoyuki; Mizumoto, Shuji [Laboratory of Proteoglycan Signaling and Therapeutics, Hokkaido University Graduate School of Life Science, Sapporo 001-0021 (Japan); Ikeda, Takayuki [Department of Advanced Biological Sciences for Regeneration (Kotobiken Medical Laboratories), Tohoku University Graduate School of Medicine, Sendai 980-8575 (Japan); Sugihara, Kazushi; Asano, Masahide [Division of Transgenic Animal Science, Advanced Science Research Center, Kanazawa University, Kanazawa 920-8640 (Japan); Yoshikawa, Takeo [Department of Advanced Biological Sciences for Regeneration (Kotobiken Medical Laboratories), Tohoku University Graduate School of Medicine, Sendai 980-8575 (Japan); Yamauchi, Akiyo [Department of Biochemistry, Nara Medical University, Kashihara 634-8521 (Japan); Shervani, Nausheen Jamal; Uruno, Akira [Department of Advanced Biological Sciences for Regeneration (Kotobiken Medical Laboratories), Tohoku University Graduate School of Medicine, Sendai 980-8575 (Japan); Kato, Ichiro [Department of Biochemistry, University of Toyama Graduate School of Medicine and Pharmaceutical Sciences, Toyama 930-0194 (Japan); Unno, Michiaki [Department of Surgery, Tohoku University Graduate School of Medicine, Sendai 980-8574 (Japan); Sugahara, Kazuyuki [Laboratory of Proteoglycan Signaling and Therapeutics, Hokkaido University Graduate School of Life Science, Sapporo 001-0021 (Japan); Takasawa, Shin [Department of Biochemistry, Nara Medical University, Kashihara 634-8521 (Japan); and others

    2009-05-22

    Heparan sulfate (HS) binds with several signaling molecules and regulates ligand-receptor interactions, playing an essential role in embryonic development. Here we showed that HS was intensively expressed in pancreatic islet {beta}-cells after 1 week of age in mice. The enzymatic removal of HS in isolated islets resulted in attenuated glucose-induced insulin secretion with a concomitant reduction in gene expression of several key components in the insulin secretion machinery. We further depleted islet HS by inactivating the exostosin tumor-like 3 gene specifically in {beta}-cells. These mice exhibited abnormal islet morphology with reduced {beta}-cell proliferation after 1 week of age and glucose intolerance due to defective insulin secretion. These results demonstrate that islet HS is involved in the regulation of postnatal islet maturation and required to ensure normal insulin secretion.

  6. Overcoming the challenges now limiting islet transplantation: a sequential, integrated approach.

    Science.gov (United States)

    Pileggi, Antonello; Cobianchi, Lorenzo; Inverardi, Luca; Ricordi, Camillo

    2006-10-01

    Steady improvements in islet cell processing technology and immunosuppressive protocols have made pancreatic islet transplantation a clinical reality for the treatment of patients with Type 1 diabetes mellitus (T1DM). Recent trials are showing that improved glycemic metabolic control, prevention of severe hypoglycemia, and better quality of life can be reproducibly achieved after transplantation of allogeneic islets in patients with unstable T1DM. Despite these encouraging results, challenges ahead comprise obtaining adequate islet cells for transplant, enhancing islets engraftment, sustaining beta cell mass and function over time, and defining effective immune interventions, among others. In order to overcome the current hurdles to the widespread application of islet transplantation there is a need for implementation of integrated, sequential therapeutic approaches.

  7. Sessile serrated adenoma (SSA) vs. traditional serrated adenoma (TSA).

    Science.gov (United States)

    Torlakovic, Emina Emilia; Gomez, Jose D; Driman, David K; Parfitt, Jeremy R; Wang, Chang; Benerjee, Tama; Snover, Dale C

    2008-01-01

    The morphologic distinction between various serrated polyps of the colorectum may be challenging. The distinction between sessile serrated adenoma (SSA) and traditional serrated adenoma (TSA) may be difficult using currently available criteria mostly based on cytologic characteristics. We have evaluated 66 serrated polyps including 29 SSA, 18 TSA, and 19 hyperplastic polyps for overall shape of the polyps, architectural features of individual crypts, the presence of eosinophilic cytoplasm, size and distribution of the proliferation and maturation zones, as well as Ki-67 and CK20 expression. The extent of the expression of CK20 and Ki-67 could not distinguish between the 3 types of serrated polyps, but the distribution of their expression was very helpful and differences were statistically significant. The distribution of Ki-67+ cells was the single most helpful distinguishing feature of the serrated polyp type (PTSA had low Ki-67 expression, which was limited to "ectopic crypts" and admixed tubular adenomalike areas. In serrated polyps, ectopic crypt formation (ECF) defined by the presence of ectopic crypts with their bases not seated adjacent to the muscularis mucosae was nearly exclusive to TSA and was found in all cases, while the presence of cytologic atypia and eosinophilia of the cytoplasm were characteristic, but not limited to TSA. No evidence of ECF, but nevertheless abnormal distribution of proliferation zone was characteristic of SSA, whereas HP had neither. The presence of the ECF defines TSA in a more rigorous fashion than previous diagnostic criteria and also explains the biologic basis of exuberant protuberant growth associated with TSA and the lack of such growth in SSA. Recognition of this phenomenon may also help in exploring the genetic and molecular basis for differences between SSA and TSA, because these architectural abnormalities may well be a reflection of abnormalities in genetically programmed mucosal development.

  8. Endothelial cells derived from the blood-brain barrier and islets of Langerhans differ in their response to the effects of bilirubin on oxidative stress under hyperglycemic conditions

    Directory of Open Access Journals (Sweden)

    Jaime eKapitulnik

    2012-07-01

    Full Text Available Unconjugated bilirubin (UCB is a neurotoxic degradation product of heme. Its toxic effects include induction of apoptosis, and ultimately neuronal cell death. However, at low concentrations, UCB is a potent antioxidant that may protect cells and tissues against oxidative stress by neutralizing toxic metabolites such as reactive oxygen species (ROS. High glucose levels (hyperglycemia generate reactive metabolites. Endothelial cell dysfunction, an early vascular complication in diabetes, has been associated with hyperglycemia-induced oxidative stress. Both glucose and UCB are substrates for transport proteins in microvascular endothelial cells of the blood-brain barrier (BBB. In the current study we show that UCB (1-40 M induces apoptosis and reduces survival of bEnd3 cells, a mouse brain endothelial cell line which serves as an in vitro model of the BBB. These deleterious effects of UCB were enhanced in the presence of high glucose (25 mM levels. Interestingly, the bEnd3 cells exhibited an increased sensitivity to the apoptotic effects of UCB when compared to the MS1 microcapillary endothelial cell line. MS1 cells originate from murine pancreatic islets of Langherans, and are devoid of the barrier characteristics of BBB-derived endothelial cells. ROS production was increased in both bEnd3 and MS1 cells exposed to high glucose, as compared with cells exposed to normal (5.5 mM glucose levels. While UCB (0.1-40 M did not alter ROS production in cells exposed to normal glucose, relatively low ('physiological' UCB concentrations (0.1-5 M attenuated ROS generation in both cell lines exposed to high glucose levels. Most strikingly, higher UCB concentrations (20-40 M increased ROS generation in bEnd3 cells exposed to high glucose, but not in similarly treated MS1 cells. These results may be of critical importance for understanding the vulnerability of the BBB endothelium upon exposure to increasing UCB levels under hyperglycemic conditions.

  9. Existence of islet regenerating factors within the pancreas.

    Science.gov (United States)

    Kanitkar, Meghana; Bhonde, Ramesh

    2004-01-01

    Reduction in the functional mass of beta-cells is a common denominator in most forms of diabetes. Since the replicative potential of beta-cells is limited, the search for factors that trigger islet neogenesis becomes imperative. Here we tested the hypothesis that regenerating factors for the pancreas are either secreted by or present within the pancreatic milieu itself. For this purpose, we intraperitoneally injected pancreatic cell culture supernatant (PCCS), from normal pancreas, into streptozotocin (STZ)-induced diabetic mice for 15 consecutive days. The PCCS-treated mice showed sustained reversal in 77.77% of experimental diabetic mice as evidenced by restoration of normoglycemia, increase in serum insulin levels and occurrence of neo islets in histopathological studies during a two month follow up, as opposed to the control diabetic mice which remained hyperglycemic throughout. In order to examine the potential of PCCS to bring about the regeneration of islets, we treated intra-islet precursor cells with PCCS in vitro, which led to the neogenesis of islets as evidenced by dithiozone and insulin immunostaining. These findings substantiate our hypothesis and make the search for regenerative factors converge towards the pancreas and its immediate surroundings. Such regenerative approaches, in combination with other therapeutic strategies to promote islet neogenesis may, in future, provide a cure and/or better means for the control and management of diabetes.

  10. Device design and materials optimization of conformal coating for islets of Langerhans.

    Science.gov (United States)

    Tomei, Alice A; Manzoli, Vita; Fraker, Christopher A; Giraldo, Jaime; Velluto, Diana; Najjar, Mejdi; Pileggi, Antonello; Molano, R Damaris; Ricordi, Camillo; Stabler, Cherie L; Hubbell, Jeffrey A

    2014-07-22

    Encapsulation of islets of Langerhans may represent a way to transplant islets in the absence of immunosuppression. Traditional methods for encapsulation lead to diffusional limitations imposed by the size of the capsules (600-1,000 μm in diameter), which results in core hypoxia and delayed insulin secretion in response to glucose. Moreover, the large volume of encapsulated cells does not allow implantation in sites that might be more favorable to islet cell engraftment. To address these issues, we have developed an encapsulation method that allows conformal coating of islets through microfluidics and minimizes capsule size and graft volume. In this method, capsule thickness, rather than capsule diameter, is constant and tightly defined by the microdevice geometry and the rheological properties of the immiscible fluids used for encapsulation within the microfluidic system. We have optimized the method both computationally and experimentally, and found that conformal coating allows for complete encapsulation of islets with a thin (a few tens of micrometers) continuous layer of hydrogel. Both in vitro and in vivo in syngeneic murine models of islet transplantation, the function of conformally coated islets was not compromised by encapsulation and was comparable to that of unencapsulated islets. We have further demonstrated that the structural support conferred by the coating materials protected islets from the loss of function experienced by uncoated islets during ex vivo culture.

  11. INDEFINITE SURVIVAL OF RAT ISLET ALLOGRAFTS FOLLOWING INFUSION OF DONOR BONE MARROW WITHOUT CYTOABLATION

    Science.gov (United States)

    Ricordi, Camillo; Murase, Norico; Rastellini, Cristiana; Behboo, Roubik; Demetris, Anthony J.; Starzl, Thomas E.

    2010-01-01

    We have tested the effect of donor bone marrow cell (DBMC) infusion on the survival of pancreatic islet allografts in the rat, without the use of cytoablative recipient conditioning. Lewis and diabetic Brown Norway rats were used as donors and recipients, respectively. Donor islets were placed beneath the left renal capsule. Infusion of DBMC and temporary immunosuppression followed by delayed islet transplantation resulted in indefinite survival of all islet grafts (MST >180 days). Control animals demonstrated recurrent hyperglycemia (islet allografts rejection). Donor bone marrow derived cells were detected in the spleen and cervical lymph nodes of BN recipients of LEW bone marrow but not in the recipients of islet transplants alone. Second set full thickness skin grafts were performed in normal BN and in recipients of a previously successful ITX. Donor specific skin grafts were accepted in the animals that had received DBMC 40 days before the islet allograft, while animals receiving DBMC at the time of the islet allograft rejected the donor specific skin graft similarly to the controls. However, these animals did not reject a second set donor-specific islet transplant. The results indicate that radiation conditioning of the recipients was not necessary to induce microchimerism and graft acceptance in this rodent model of islet allotransplantation. PMID:8665077

  12. Transient Suppression of TGFβ Receptor Signaling Facilitates Human Islet Transplantation.

    Science.gov (United States)

    Xiao, Xiangwei; Fischbach, Shane; Song, Zewen; Gaffar, Iljana; Zimmerman, Ray; Wiersch, John; Prasadan, Krishna; Shiota, Chiyo; Guo, Ping; Ramachandran, Sabarinathan; Witkowski, Piotr; Gittes, George K

    2016-04-01

    Although islet transplantation is an effective treatment for severe diabetes, its broad application is greatly limited due to a shortage of donor islets. Suppression of TGFβ receptor signaling in β-cells has been shown to increase β-cell proliferation in mice, but has not been rigorously examined in humans. Here, treatment of human islets with a TGFβ receptor I inhibitor, SB-431542 (SB), significantly improved C-peptide secretion by β-cells, and significantly increased β-cell number by increasing β-cell proliferation. In addition, SB increased cell-cycle activators and decreased cell-cycle suppressors in human β-cells. Transplantation of SB-treated human islets into diabetic immune-deficient mice resulted in significant improvement in blood glucose control, significantly higher serum and graft insulin content, and significantly greater increases in β-cell proliferation in the graft, compared with controls. Thus, our data suggest that transient suppression of TGFβ receptor signaling may improve the outcome of human islet transplantation, seemingly through increasing β-cell number and function.

  13. Long-term effect of pH on B-cell function in isolated islets of Langerhans in tissue culture

    DEFF Research Database (Denmark)

    Brunstedt, J; Nielsen, Jens Høiriis

    1978-01-01

    Collagenase isolated mouse pancreatic islets were maintained in tissue culture for up to 5 months in a culture medium buffered with Hepes and the pH varying between 6.8 and 7.6. The amount of insulin released into the medium and the insulin response to glucose and glucose plus theophylline were...... glucose and glucose plus theophylline than islets cultured at the other pH values, but later they lost their insulin releasing ability....

  14. Adeno-associated virus (AAV) as a vehicle for therapeutic gene delivery: improvements in vector design and viral production enhance potential to prolong graft survival in pancreatic islet cell transplantation for the reversal of type 1 diabetes.

    Science.gov (United States)

    Kapturczak, M H; Flotte, T; Atkinson, M A

    2001-05-01

    Most viral gene delivery syslems utilized to date have demonstrated significant limitations in practicality and safety due to the level and duration of recombinant transgene expression as well as their induction of host immunogenicity to vector proteins. Recombinant adeno-associated virus (rAAV) vectors appear to offer a vehicle for safe, long-term therapeutic gene transfer; factors afforded through the propensity of rAAV to establish long-term latency without deleterious effects on the host cell and the relative non-immunogenicity of the virus or viral expressed transgenes. The principal historical limitation of this vector system, efficiency of rAAV-mediated transduction, has recently observed a dramatic increase as the titer, purity, and production capacity of rAAV preparations have improved. In terms of systems that could benefit from such improvements, rAAV gene therapy to enhance solid organ transplantation would appear an obvious choice with islet transplantation forming a promising candidate due to the ability to perform viral transductions ex vivo. Currently, islet transplantation can be used to treat type 1 diabetes yet persisting alloimmune and autoimmune responses represent major obstacles to the clinical success for this procedure. The delivery of transgenes capable of interfering with antigenic recognition and/or cell death [e.g., Fas ligand (FasL), Bcl-2, Bcl-XL] as well as imparting tolerance/immunoregulation [e.g., interleukin(IL)-4, IL-10, transforming growth factor (TGF)-beta], or cytoprotection [e.g., heme oxygenase-1 (HO-1), catalase, manganese superoxide dismutase (MnSOD)] may prevent recurrent type 1 diabetes in islet transplantation and offer a promising form of immunotherapy. Research investigations utilizing such systems may also provide information vital to understanding the immunoregulatory mechanisms critical to the development of both alloimmune and autoimmune islet cell rejection mechanisms and recurrent type 1 diabetes.

  15. 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

  16. Survival of free and encapsulated human and rat islet xenografts transplanted into the mouse bone marrow.

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    Raphael P H Meier

    Full Text Available Bone marrow was recently proposed as an alternative and potentially immune-privileged site for pancreatic islet transplantation. The aim of the present study was to assess the survival and rejection mechanisms of free and encapsulated xenogeneic islets transplanted into the medullary cavity of the femur, or under the kidney capsule of streptozotocin-induced diabetic C57BL/6 mice. The median survival of free rat islets transplanted into the bone marrow or under the kidney capsule was 9 and 14 days, respectively, whereas that of free human islets was shorter, 7 days (bone marrow and 10 days (kidney capsule. Infiltrating CD8+ T cells and redistributed CD4+ T cells, and macrophages were detected around the transplanted islets in bone sections. Recipient mouse splenocytes proliferated in response to donor rat stimulator cells. One month after transplantation under both kidney capsule or into bone marrow, encapsulated rat islets had induced a similar degree of fibrotic reaction and still contained insulin positive cells. In conclusion, we successfully established a small animal model for xenogeneic islet transplantation into the bone marrow. The rejection of xenogeneic islets was associated with local and systemic T cell responses and macrophage recruitment. Although there was no evidence for immune-privilege, the bone marrow may represent a feasible site for encapsulated xenogeneic islet transplantation.

  17. Treatment with the dipeptidyl peptidase-4 inhibitor vildagliptin improves fasting islet-cell function in subjects with type 2 diabetes.

    Science.gov (United States)

    D'Alessio, David A; Denney, Amanda M; Hermiller, Linda M; Prigeon, Ronald L; Martin, Julie M; Tharp, William G; Saylan, Monica Liqueros; He, Yanling; Dunning, Beth E; Foley, James E; Pratley, Richard E

    2009-01-01

    Dipeptidyl peptidase 4 (DPP-4) inhibitors are proposed to lower blood glucose in type 2 diabetes mellitus (T2DM) by prolonging the activity of the circulating incretins, glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide 1 (GLP-1). Consistent with this mechanism of action, DPP-4 inhibitors improve glucose tolerance after meals by increasing insulin and reducing glucagon levels in the plasma. However, DPP-4 inhibitors also reduce fasting blood glucose, an unexpected effect because circulating levels of active GIP and GLP-1 are low in the postabsorptive state. The objective of the study was to examine the effects of DPP-4 inhibition on fasting islet function. We conducted a randomized, double-blind, placebo-controlled trial. The study was performed in General Clinical Research Centers at two University Hospitals. Forty-one subjects with T2DM were treated with metformin or diet, having good glycemic control with glycosylated hemoglobin values of 6.2-7.5%. Subjects were treated with vildagliptin (50 mg twice daily) or placebo for 3 months, followed by a 2-wk washout. Major Outcome Measure: We measured insulin secretion in response to iv glucose and arginine before and after treatment and after drug washout. There were small and comparable reductions in glycosylated hemoglobin in both groups over 3 months. Vildagliptin increased fasting GLP-1 levels in subjects taking metformin, but not those managed with diet, and raised active GIP levels slightly. DPP-4 inhibitor treatment improved the acute insulin and C-peptide responses to glucose (50 and 100% respectively; P fasting conditions. This suggests that DPP-4 inhibition has metabolic benefits in addition to enhancing meal-induced GLP-1 and GIP activity.

  18. Neurotransmitters act as paracrine signals to regulate insulin secretion from the human pancreatic islet.

    Science.gov (United States)

    Rodriguez-Diaz, Rayner; Menegaz, Danusa; Caicedo, Alejandro

    2014-08-15

    In this symposium review we discuss the role of neurotransmitters as paracrine signals that regulate pancreatic islet function. A large number of neurotransmitters and their receptors has been identified in the islet, but relatively little is known about their involvement in islet biology. Interestingly, neurotransmitters initially thought to be present in autonomic axons innervating the islet are also present in endocrine cells of the human islet. These neurotransmitters can thus be released as paracrine signals to help control hormone release. Here we propose that the role of neurotransmitters may extend beyond controlling endocrine cell function to work as signals modulating vascular flow and immune responses within the islet. © 2014 The Authors. The Journal of Physiology © 2014 The Physiological Society.

  19. Characterisation of the xenogeneic immune response to microencapsulated fetal pig islet-like cell clusters transplanted into immunocompetent C57BL/6 mice.

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    Vijayaganapathy Vaithilingam

    Full Text Available Xenotransplantation of microencapsulated fetal pig islet-like cell clusters (FP ICCs offers a potential cellular therapy for type 1 diabetes. Although microcapsules prevent direct contact of the host immune system with the xenografted tissue, poor graft survival is still an issue. This study aimed to characterise the nature of the host immune cells present on the engrafted microcapsules and effects on encapsulated FP ICCs that were transplanted into immunocompetent mice. Encapsulated FP ICCs were transplanted into the peritoneal cavity of C57BL/6 mice. Grafts retrieved at days 1, 3, 7, 14 and 21 post-transplantation were analysed for pericapsular fibrotic overgrowth (PFO, cell viability, intragraft porcine gene expression, macrophages, myofibroblasts and intraperitoneal murine cytokines. Graft function was assessed ex vivo by insulin secretion studies. Xenogeneic immune response to encapsulated FP ICCs was associated with enhanced intragraft mRNA expression of porcine antigens MIP-1α, IL-8, HMGB1 and HSP90 seen within the first two weeks post-transplantation. This was associated with the recruitment of host macrophages, infiltration of myofibroblasts and collagen deposition leading to PFO which was evident from day 7 post-transplantation. This was accompanied by a decrease in cell viability and loss of FP ICC architecture. The only pro-inflammatory cytokine detected in the murine peritoneal flushing was TNF-α with levels peaking at day 7 post transplantation. This correlated with the onset of PFO at day 7 implying activated macrophages as its source. The anti-inflammatory cytokines detected were IL-5 and IL-4 with levels peaking at days 1 and 7, respectively. Porcine C-peptide was undetectable at all time points post-transplantation. PFO was absent and murine intraperitoneal cytokines were undetectable when empty microcapsules were transplanted. In conclusion, this study demonstrated that the macrophages are direct effectors of the xenogeneic

  20. The Frequency of Langerhans Islets β-Cells Autoantibodies (Anti-GAD in Georgian Children and Adolescents with Chronic Autoimmune Thyroiditis

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    Mariam Balakhadze

    2016-01-01

    Full Text Available Aim. Chronic autoimmune thyroiditis and type 1 diabetes mellitus are organ-specific autoimmune diseases. There is large evidence that autoimmunity against the thyroid gland in patients with type 1 diabetes mellitus is increased, but little is known about anti-islet cell autoimmune status in patients with chronic autoimmune thyroiditis. We evaluated the concentration of antibodies against glutamic acid decarboxylase (GAD which are widely used as a diagnostic and predictive tool for type 1 diabetes mellitus, in school-aged Georgian children with chronic autoimmune thyroiditis. Methods. The frequency of anti-GAD antibodies was measured in Georgian school-aged children with chronic autoimmune thyroiditis and compared to healthy age and sex matched controls. Results. Of the 41 patients with chronic autoimmune thyroiditis 4 (9.8% were positive for GAD antibodies. The frequency of GAD positivity in the chronic autoimmune thyroiditis group was significantly higher than in the control subjects (P=0.036. Conclusion. In the study we found that the frequency of GAD antibody positivity in autoimmune thyroiditis patients was significantly higher (9.8%, P=0.036 than in the control group. Our findings support the concept that patients with autoimmune thyroid disease may develop type 1 diabetes mellitus in future life.

  1. Alginate Microencapsulation of Human Islets Does Not Increase Susceptibility to Acute Hypoxia

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    I. K. Hals

    2013-01-01

    Full Text Available Islet transplantation in diabetes is hampered by the need of life-long immunosuppression. Encapsulation provides partial immunoprotection but could possibly limit oxygen supply, a factor that may enhance hypoxia-induced beta cell death in the early posttransplantation period. Here we tested susceptibility of alginate microencapsulated human islets to experimental hypoxia (0.1–0.3% O2 for 8 h, followed by reoxygenation on viability and functional parameters. Hypoxia reduced viability as measured by MTT by 33.8±3.5% in encapsulated and 42.9±5.2% in nonencapsulated islets (P<0.2. Nonencapsulated islets released 37.7% (median more HMGB1 compared to encapsulated islets after hypoxic culture conditions (P<0.001. Glucose-induced insulin release was marginally affected by hypoxia. Basal oxygen consumption was equally reduced in encapsulated and nonencapsulated islets, by 22.0±6.1% versus 24.8±5.7%. Among 27 tested cytokines/chemokines, hypoxia increased the secretion of IL-6 and IL-8/CXCL8 in both groups of islets, whereas an increase of MCP-1/CCL2 was seen only with nonencapsulated islets. Conclusion. Alginate microencapsulation of human islets does not increase susceptibility to acute hypoxia. This is a positive finding in relation to potential use of encapsulation for islet transplantation.

  2. Evaluation of Alginate Microcapsules for Use in Transplantation of Islets of Langerhans

    OpenAIRE

    King, Aileen

    2001-01-01

    Transplantation of islets of Langerhans is a potential treatment of type 1 diabetes that aims to restore normal glucose homeostasis. Microencapsulation of islets could enable transplantation in the absence of immunosuppression, which would be beneficial as the side effects associated with immunosuppression outweigh the potential benefits of islet transplantation. Alginate is a polysaccharide that can be harvested from brown algae and is often used for microencapsulation of cells. The aim of t...

  3. Orbital Lymphoma Mimicking Lacrimal Gland Pleomorphic Adenoma

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    Diego Strianese

    2013-09-01

    Full Text Available Purpose: To describe the case of a patient affected by orbital lymphoma mimicking pleomorphic adenoma of the lacrimal gland. Methods: This was a retrospective case report. Results: We present the case of a patient with 15-year history of slowly progressive left proptosis and inferomedial bulbar dislocation who had the presumptive diagnosis of lacrimal gland pleomorphic adenoma based on clinical and radiological features. The patient underwent lateral orbitotomy and lacrimal gland excision. Postoperative histological features were consistent with low-grade B-cell non-Hodgkin lymphoma. Conclusion: The accepted clinico-radiological criteria used for the diagnosis of lacrimal gland fossa lesions might have a certain false-positive rate, even in recent years. The initial surgical approach with the appropriate choice between fine-needle aspiration biopsies, intraoperative biopsies and lacrimal gland excisions might be a challenge.

  4. A preclinical evaluation of alternative site for islet allotransplantation.

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    Chengshi Wang

    Full Text Available The bone marrow cavity (BMC has recently been identified as an alternative site to the liver for islet transplantation. This study aimed to compare the BMC with the liver as an islet allotransplantation site in diabetic monkeys. Diabetes was induced in Rhesus monkeys using streptozocin, and the monkeys were then divided into the following three groups: Group1 (islets transplanted in the liver with immunosuppressant, Group 2 (islets transplanted in the tibial BMC, and Group 3 (islets transplanted in the tibial BMC with immunosuppressant. The C-peptide and blood glucose levels were preoperatively measured. An intravenous glucose tolerance test (IVGTT was conducted to assess graft function, and complete blood cell counts were performed to assess cell population changes. Cytokine expression was measured using an enzyme-linked immune sorbent assay (ELISA and MILLIPLEX. Five monkeys in Group 3 exhibited a significantly increased insulin-independent time compared with the other groups (Group 1: 78.2 ± 19.0 days; Group 2: 58.8 ± 17.0 days; Group 3: 189.6 ± 26.2 days and demonstrated increases in plasma C-peptide 4 months after transplantation. The infusion procedure was not associated with adverse effects. Functional islets in the BMC were observed 225 days after transplantation using the dithizone (DTZ and insulin/glucagon stains. Our results showed that allogeneic islets transplanted in the BMC of diabetic Rhesus monkeys remained alive and functional for a longer time than those transplanted in the liver. This study was the first successful demonstration of allogeneic islet engraftment in the BMC of non-human primates (NHPs.

  5. Thomsen-Friedenreich (T) antigen as marker of myoepithelial and basal cells in the parotid gland, pleomorphic adenomas and adenoid cystic carcinomas. An immunohistological comparison between T and sialosyl-T antigens, alpha-smooth muscle actin and cytokeratin 14

    DEFF Research Database (Denmark)

    Therkildsen, M H; Mandel, U; Christensen, M

    1995-01-01

    was the only marker of cells in solid undifferentiated areas of adenoid cystic carcinomas. Our study supports the view, that modified "myoepithelial" cells in the tumours consist of a mixture of basal cells and myoepithelial cells. None of the investigated structures was in itself an ideal marker......Controversy centres on the role and identification of myoepithelial (MEC) and basal cells in salivary gland tumours, and recent studies suggest that both basal cells and myoepithelial cells participate in the formation of salivary gland tumours. We have correlated the expression of different well......-known markers of normal MEC/basal cells (i.e. alpha-smooth muscle actin and cytokeratin 14) with T (Thomsen-Friedenreich) antigen and its sialylated derivative: sialosyl-T antigen,) in 17 normal parotid glands and in two tumour types with MEC participation (i.e pleomorphic adenomas (PA) and adenoid cystic...

  6. Deleterious effect of dithizone-DMSO staining on insulin secretion in rat and human pancreatic islets.

    Science.gov (United States)

    Conget, J I; Sarri, Y; González-Clemente, J M; Casamitjana, R; Vives, M; Gomis, R

    1994-03-01

    Dithizone (DTZ) is a selective stain for pancreatic islets which facilitates their identification, being of special interest in human islet isolation assessment. Nevertheless, there are few studies concerning its potential toxic effects on islet function. In our study, we have evaluated the effects of DTZ (dissolved in dimethyl sulfoxide [DMSO] 1% w/v) at three different concentrations (2, 10, and 100 micrograms/ml) on insulin response to glucose in human and rat islets. Likewise, we studied the effect of incubation time, in the presence of DTZ at the above-mentioned concentrations, on insulin release. Only when DTZ was employed at low concentrations and for a short period of incubation (10 min) was there no impairment of pancreatic islet function. Moreover, even at this low concentration, DTZ became deleterious for islet function when the incubation period with the dye was prolonged for 30 min. Culture (24 h) of previously stained islets produced a partial recovery of insulin response. In conclusion, our findings indicate (a) DTZ should not be employed to collect islets for functional studies because of its deleterious effect on beta-cell function, (b) DTZ's deleterious effects on beta-cell function should be considered if this dye is used to purify islets by fluorescence-activated cell sorting for transplantation.

  7. Imaging of giant pituitary adenomas

    Energy Technology Data Exchange (ETDEWEB)

    Majos, C.; Coll, S.; Aguilera, C.; Pons, L.C. [Bellvitge Univ., Barcelona (Spain). Inst. de Diagnostice per la Imatge; Acebes, J.J. [Department of Neurosurgery, Ciutat Sanitaria i Universitaria de Bellvitge, L`Hospitalet de Llobregat, Barcelona (Spain)

    1998-10-01

    We present five proven giant pituitary adenomas studied by CT and MRI, and review the clinical and imaging findings. Our aim was to examine the radiologic appearances and to search for criteria useful in distinguishing these tumors from other sellar and suprasellar tumours, mainly craniopharyngioma. The main differences from small adenomas were high prevalence of macrocysts, a more invasive behaviour and a clinical picture dominated by mass effect rather than endocrine disturbance. Factors supporting the diagnosis of pituitary adenoma in a giant intra- and suprasellar mass include: infrasellar extension, absence of calcification and presence of low-signal cysts on T1-weighted images. (orig.) (orig.) With 4 figs., 2 tabs., 9 refs.

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

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    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.

  9. Rat islet isolation yield and function are donor strain dependent

    NARCIS (Netherlands)

    de Groot, M; de Haan, BJ; Schuurs, TA; van Schilfgaarde, R; Leuvenink, HGD; KEIZER, J

    Effective rat islet isolation is pertinent for successful islet transplantation and islet studies in vitro. To determine which rat strain yields the highest number of pure and functional islets, four commonly used rat strains were compared with regard to islet yield, islet purity and islet function.

  10. P27 expression in pleomorphic salivary gland adenoma.

    Science.gov (United States)

    Tarakji, Bassel; Umair, Ayesha; Altamimi, Mohammed Alsakran; Azzeghaiby, Saleh Nasser; Mahmoud, Abla Sayed; Darwish, Shourouk; Nassani, Mohammad Zakaria; Ashok, Nipun

    2015-01-01

    This study aims to characterise alterations in the immunohistochemical expression of p27 in normal tissue of the salivary gland surrounding pleomorphic adenoma and in the tumour cells of pleomorphic adenoma. A retrospective study of data including 120 cases of pleomorphic adenomas (66 female, 54 male) retrieved from the files of the Oral Pathology Departments of Aleppo University, Syria and Al-Farabi Dental and Nursing College. Immunohistochemical expression against p27 was examined in the selected cases. The percentage of p27-positive nuclei was semi-quantitatively assessed by two independent observers and scores were given. The statistical analysis included the use of descriptive statistics and proportional frequencies. The results showed that P27 nuclear staining with high staining (moderate to strong positive staining in more than 50% of nuclei, depending on the percentage of nuclei for the cells) was noted in tumour duct cells of pleomorphic adenoma in 90 (75%) cases out of 120, while 30 (25%) cases showed low staining (positive staining in less than 5% of nuclei, depending on the percentage of nuclei for the cells). Our data suggests that p27 might have a minor role in the development of pleomorphic adenoma.

  11. Magnetic resonance imaging of mouse islet grafts labeled with novel chitosan-coated superparamagnetic iron oxide nanoparticles.

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    Jyuhn-Huarng Juang

    Full Text Available OBJECT: To better understand the fate of islet isografts and allografts, we utilized a magnetic resonance (MR imaging technique to monitor mouse islets labeled with a novel MR contrast agent, chitosan-coated superparamagnetic iron oxide (CSPIO nanoparticles. MATERIALS AND METHODS: After being incubated with and without CSPIO (10 µg/ml, C57BL/6 mouse islets were examined under transmission electron microscope (TEM and their insulin secretion was measured. Cytotoxicity was examined in α (αTC1 and β (NIT-1 and βTC cell lines as well as islets. C57BL/6 mice were used as donors and inbred C57BL/6 and Balb/c mice were used as recipients of islet transplantation. Three hundred islets were transplanted under the left kidney capsule of each mouse and then MR was performed in the recipients periodically. At the end of study, the islet graft was removed for histology and TEM studies. RESULTS: After incubation of mouse islets with CSPIO (10 µg/mL, TEM showed CSPIO in endocytotic vesicles of α- and β-cells at 8 h. Incubation with CSPIO did not affect insulin secretion from islets and death rates of αTC1, NIT-1 and βTC cell lines as well as islets. After syngeneic and allogeneic transplantation, grafts of CSPIO-labeled islets were visualized on MR scans as persistent hypointense areas. At 8 weeks after syngeneic transplantation and 31 days after allogeneic transplantation, histology of CSPIO-labeled islet grafts showed colocalized insulin and iron staining in the same areas but the size of allografts decreased with time. TEM with elementary iron mapping demonstrated CSPIO distributed in the cytoplasm of islet cells, which maintained intact ultrastructure. CONCLUSION: Our results indicate that after syngeneic and allogeneic transplantation, islets labeled with CSPIO nanoparticles can be effectively and safely imaged by MR.

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

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    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.

  13. Cytopathological features of villous adenoma of the urinary bladder in urine: A rare case report.

    Science.gov (United States)

    Ishikawa, Ryou; Kadota, Kyuichi; Hayashi, Toshitetsu; Motoyama, Mutsumi; Matsunaga, Toru; Miyai, Yumi; Katsuki, Naomi; Kushida, Yoshio; Haba, Reiji

    2016-07-01

    Villous adenoma of the urinary bladder is a rare tumor that histologically mimics its enteric counterpart. Patients with an isolated villous adenoma have an excellent prognosis, but associated adenocarcinomas can frequently be identified in them as well. There is no literature that discusses the cytopathologic features of villous adenoma. Here we report a case which was diagnosed as villous adenoma histologically, which has been followed up with urine cytology. In urine cytology, many mucin producing cells are recognized. Few cell clusters show glandular formation or arrangement along the basement membrane. When glandular cells with columnar mucin-filled goblet cells are seen in urine cytology, the presence of a primary glandular lesion of the urinary bladder, such as villous adenoma, should be considered possible. Diagn. Cytopathol. 2016;44:632-635. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  14. Radio-sensitization by Piper longumine of human breast adenoma MDA-MB-231 cells in vitro.

    Science.gov (United States)

    Yao, Jian-Xin; Yao, Zhi-Feng; Li, Zhan-Feng; Liu, Yong-Biao

    2014-01-01

    The current study investigated the effects of Piper longumine on radio-sensitization of human breast cancer MDA-MB-231 cells and underlying mechanisms. Human breast cancer MDA-MB-231 cells were cultured in vitro and those in logarithmic growth phase were selected for experiments divided into four groups: control, X-ray exposed, Piper longumine, and Piper longumine combined with X-rays. Conogenic assays were performed to determine the radio-sensitizing effects. Cell survival curves were fitted by single-hit multi-target model and then the survival fraction (SF), average lethal dose (D0), quasi-threshold dose (Dq) and sensitive enhancement ratio (SER) were calculated. Cell apoptosis was analyzed by flow cytometry (FCM).Western blot assays were employed for expression of apoptosis-related proteins (Bc1-2 and Bax) after treatment with Piper longumine and/or X-ray radiation. The intracellular reactive oxygen species (ROS) level was detected by FCM with a DCFH-DA probe. The cloning formation capacity was decreased in the group of piperlongumine plus radiation, which displayed the values of SF2, D0, Dq significantly lower than those of radiation alone group and the sensitive enhancement ratio (SER) of D0 was1.22 and 1.29, respectively. The cell apoptosis rate was increased by the combination treatment of Piper longumine and radiation. Piper longumine increased the radiation-induced intracellular levels of ROS. Compared with the control group and individual group, the combination group demonstrated significantly decreased expression of Bcl-2 with increased Bax. Piper longumine at a non-cytotoxic concentration can enhance the radio-sensitivity of MDA- MB-231cells, which may be related to its regulation of apoptosis-related protein expression and the increase of intracellular ROS level, thus increasing radiation-induced apoptosis.

  15. Expression and regulation of nampt in human islets.

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    Karen Kover

    Full Text Available Nicotinamide phosphoribosyltransferase (Nampt is a rate-limiting enzyme in the mammalian NAD+ biosynthesis of a salvage pathway and exists in 2 known forms, intracellular Nampt (iNampt and a secreted form, extracellular Nampt (eNampt. eNampt can generate an intermediate product, nicotinamide mononucleotide (NMN, which has been reported to support insulin secretion in pancreatic islets. Nampt has been reported to be expressed in the pancreas but islet specific expression has not been adequately defined. The aim of this study was to characterize Nampt expression, secretion and regulation by glucose in human islets. Gene and protein expression of Nampt was assessed in human pancreatic tissue and isolated islets by qRT-PCR and immunofluorescence/confocal imaging respectively. Variable amounts of Nampt mRNA were detected in pancreatic tissue and isolated islets. Immunofluorescence staining for Nampt was found in the exocrine and endocrine tissue of fetal pancreas. However, in adulthood, Nampt expression was localized predominantly in beta cells. Isolated human islets secreted increasing amounts of eNampt in response to high glucose (20 mM in a static glucose-stimulated insulin secretion assay (GSIS. In addition to an increase in eNampt secretion, exposure to 20 mM glucose also increased Nampt mRNA levels but not protein content. The secretion of eNampt was attenuated by the addition of membrane depolarization inhibitors, diazoxide and nifedipine. Islet-secreted eNampt showed enzymatic activity in a reaction with increasing production of NAD+/NADH over time. In summary, we show that Nampt is expressed in both exocrine and endocrine tissue early in life but in adulthood expression is localized to endocrine tissue. Enzymatically active eNampt is secreted by human islets, is regulated by glucose and requires membrane depolarization.

  16. Localization of carboxyl ester lipase in human pituitary gland and pituitary adenomas.

    Science.gov (United States)

    La Rosa, Stefano; Vigetti, Davide; Placidi, Claudia; Finzi, Giovanna; Uccella, Silvia; Clerici, Moira; Bartolini, Barbara; Carnevali, Ileana; Losa, Marco; Capella, Carlo

    2010-10-01

    Carboxyl ester lipase (CEL) is an enzyme that hydrolyzes a wide variety of lipid substrates, including ceramides, which are known to show inhibitory regulation of pituitary hormone secretion in experimental models. Because no studies on CEL expression in human pituitary and pituitary adenomas have been reported in the literature, we investigated CEL expression in 10 normal pituitary glands and 86 well-characterized pituitary adenomas [12 FSH/LH cell, 17 α-subunit/null cell, 6 TSH cell, 21 ACTH cell, 11 prolactin (PRL) cell, and 19 GH cell adenomas] using IHC, immunoelectron microscopy, Western blotting, and quantitative RT-PCR. In normal adenohypophysis, CEL was localized in GH, ACTH, and TSH cells. In adenomas, it was mainly found in functioning GH, ACTH, and TSH tumors, whereas its expression was poor in the corresponding silent adenomas and was lacking in FSH/LH cell, null cell, and PRL cell adenomas. Ultrastructurally, CEL was localized in secretory granules close to their membranes. This is the first study demonstrating CEL expression in normal human pituitary glands and in functioning GH, ACTH, and TSH adenomas. Considering that CEL hydrolyzes ceramides, inactivating their inhibitory function on pituitary hormone secretion, our findings suggest a possible role of CEL in the regulation of hormone secretion in both normal and adenomatous pituitary cells.

  17. 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.

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    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.

  18. Immature transformed rat islet beta-cells differentially express C-peptides derived from the genes coding for insulin I and II as well as a transfected human insulin gene

    DEFF Research Database (Denmark)

    Blume, N; Petersen, J S; Andersen, L C

    1992-01-01

    and were absent after more than 50 successive passages, while a C-peptide I-producing population was still present. Double-labeling experiments revealed a heterogeneous distribution of the three different C-peptides. Surprisingly, in the early passages a large fraction of cells would express only a single...... is induced in the transformed heterogeneous rat islet cell clone, NHI-6F, by transient in vivo passage. During this process a transfected human insulin gene is coactivated with the endogenous nonallelic rat insulin I and II genes. Newly established cultures from NHI-6F insulinomas having a high frequency...

  19. Macro- or microencapsulation of pig islets to cure type 1 diabetes.

    Science.gov (United States)

    Dufrane, Denis; Gianello, Pierre

    2012-12-21

    Although allogeneic islet transplantation can successfully cure type 1 diabetes, it has limited applicability. For example, organs are in short supply; several human pancreas donors are often needed to treat one diabetic recipient; the intrahepatic site may not be the most appropriate site for islet implantation; and immunosuppressive regimens, which are associated with side effects, are often required to prolong survival of the islet graft. An alternative source of insulin-producing cells would therefore be of major interest. Pigs represent a possible alternative source of beta cells. Grafting of pig islets may appear difficult because of the immunologic species barrier, but pig islets have been shown to function in primates for at least 6 mo with clinically incompatible immunosuppression. Therefore, a bioartificial pancreas made of encapsulated pig islets may resolve issues associated with islet allotransplantation. Although several groups have shown that encapsulated pig islets are functional in small-animal models, less is known about the use of bioartificial pancreases in large-animal models. In this review, we summarize current knowledge of encapsulated pig islets, to determine obstacles to implantation in humans and possible solutions to overcome these obstacles.

  20. Staining and in vitro toxicity of dithizone with canine, porcine, and bovine islets.

    Science.gov (United States)

    Clark, S A; Borland, K M; Sherman, S D; Rusack, T C; Chick, W L

    1994-01-01

    Dithizone (DTZ) is a recognized diabetogenic agent in vivo, and a supravital stain commonly used for identification of islets to be used for transplantation. In the present studies, we compared DTZ staining of freshly isolated and cultured canine, bovine, and porcine islets, and the effect of DTZ on the function and viability of islets. Incubation with DTZ resulted in staining of canine and porcine islets, but no discernible staining with bovine islets. Insulin content of porcine, canine, and bovine islet was 2.0 +/- 0.2, 2.2 +/- 0.3, and 1.9 +/- 0.2 mU/EIN, indicating a lack of correspondence of DTZ staining and insulin content. Seven days of culture with canine islets resulted in > or = 50% reduction of DTZ stained cells. Exposure to DTZ at 50 micrograms/mL resulted in a maximal number of stained cells in preparations of purified islets (80-85%; counted after dispersion), a lower percentage of cells stained faintly at 20 micrograms/mL (50-55%), with no discernible staining at 10 micrograms/mL. Prolonged exposure of islets (4-48 h) to 20 micrograms/mL DTZ led to reduced insulin secretion and islet cell death. Incubation of canine or porcine islets with 100 micrograms/mL of DTZ for 0.5 h resulted in a dramatic loss of viability and diminished insulin secretory function, which was not reversed with continued culture. The concentration dependence of toxic effects paralleled the concentration dependence of cellular staining. The minimally effective staining concentration (20 micrograms/mL) also resulted in a loss of viability. An additional assessment of DTZ toxicity was made using the RIN-38 beta-cell line, which shows no discernible staining with DTZ.(ABSTRACT TRUNCATED AT 250 WORDS)

  1. SOX10-positive salivary gland tumors: a growing list, including mammary analogue secretory carcinoma of the salivary gland, sialoblastoma, low-grade salivary duct carcinoma, basal cell adenoma/adenocarcinoma, and a subgroup of mucoepidermoid carcinoma.

    Science.gov (United States)

    Hsieh, Min-Shu; Lee, Yi-Hsuan; Chang, Yih-Leong

    2016-10-01

    Transcription factor SRY-related HMG-box 10 (SOX10) is an important marker for melanocytic, schwannian, myoepithelial, and some salivary gland tumors. The aim of this study was to investigate SOX10 expression more thoroughly in the salivary gland neoplasms, including mammary analogue secretory carcinoma and hyalinizing clear cell carcinoma harboring specific genetic rearrangements. A new rabbit monoclonal anti-SOX10 antibody (clone EP268) was used to examine SOX10 expression in 14 different types of salivary gland tumors. We found that acinic cell carcinoma (AciCC), adenoid cystic carcinoma, mammary analogue secretory carcinoma (MASC), epithelial-myoepithelial carcinoma, low-grade salivary duct carcinoma, sialoblastoma, basal cell adenocarcinoma, basal cell adenoma, and pleomorphic adenoma were SOX10 positive. Salivary duct carcinoma, lymphoepithelial carcinoma, hyalinizing clear cell carcinoma, and oncocytoma were SOX10 negative. Earlier, mucoepidermoid carcinoma (MEC) was considered a SOX10-negative tumor. This study identified a subgroup of SOX10-positive MEC cases with characteristic polygonal epithelial cells, pale-to-eosinophilic cytoplasm, and colloid-like dense eosinophilic material. Our data show SOX10 expression can be observed in salivary gland tumors with either one of the 4 <