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Sample records for beta cell mass

  1. Imaging the Beta-cell mass: why and how

    DEFF Research Database (Denmark)

    Saudek, Frantisek; Brogren, Carl-Henrik; Manohar, Srirang

    2008-01-01

    to the lack of a beta-cell-specific contrast agent. The only existing method to monitor islet cells in vivo consists of labeling islet transplants with iron nanoparticles prior to transplantation and visualization of the transplanted islets by magnetic resonance imaging (MRI). Therefore, accurate assessment......Diabetes is a disorder characterized by beta-cell loss or exhaustion and insulin deficiency. At present, knowledge is lacking on the underlying causes and for the therapeutic recovery of the beta-cell mass. A better understanding of diabetes pathogenesis could be obtained through exact monitoring...

  2. Beta Cell Count Instead of Beta Cell Mass to Assess and Localize Growth in Beta Cell Population following Pancreatic Duct Ligation in Mice

    Science.gov (United States)

    Chintinne, Marie; Stangé, Geert; Denys, Bart; Ling, Zhidong; In ‘t Veld, Peter; Pipeleers, Daniel

    2012-01-01

    Background Pancreatic-tail duct ligation (PDL) in adult rodents has been reported to induce beta cell generation and increase beta cell mass but increases in beta cell number have not been demonstrated. This study examines whether PDL increases beta cell number and whether this is caused by neogenesis of small clusters and/or their growth to larger aggregates. Methodology Total beta cell number and its distribution over small (100 µm) clusters was determined in pancreatic tails of 10-week-old mice, 2 weeks after PDL or sham. Principal findings PDL increased total beta cell mass but not total beta cell number. It induced neogenesis of small beta cell clusters (2.2-fold higher number) which contained a higher percent proliferating beta cells (1.9% Ki67+cells) than sham tails (beta cell number represented beta cell number and was associated with a similar increase in alpha cell number. It is unknown whether the regenerative process is causally related to the inflammatory infiltration in PDL-tails. Human pancreases with inflammatory infiltration also exhibited activation of proliferation in small beta cell clusters. Conclusions/significance The PDL model illustrates the advantage of direct beta cell counts over beta cell mass measurements when assessing and localizing beta cell regeneration in the pancreas. It demonstrates the ability of the adult mouse pancreas for neogenesis of small beta cell clusters with activated beta cell proliferation. Further studies should investigate conditions under which neoformed small beta cell clusters grow to larger aggregates and hence to higher total beta cell numbers. PMID:22952825

  3. Beta cell count instead of beta cell mass to assess and localize growth in beta cell population following pancreatic duct ligation in mice.

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    Marie Chintinne

    Full Text Available BACKGROUND: Pancreatic-tail duct ligation (PDL in adult rodents has been reported to induce beta cell generation and increase beta cell mass but increases in beta cell number have not been demonstrated. This study examines whether PDL increases beta cell number and whether this is caused by neogenesis of small clusters and/or their growth to larger aggregates. METHODOLOGY: Total beta cell number and its distribution over small (100 µm clusters was determined in pancreatic tails of 10-week-old mice, 2 weeks after PDL or sham. PRINCIPAL FINDINGS: PDL increased total beta cell mass but not total beta cell number. It induced neogenesis of small beta cell clusters (2.2-fold higher number which contained a higher percent proliferating beta cells (1.9% Ki67+cells than sham tails (<0.2%; their higher beta cell number represented <5% of total beta cell number and was associated with a similar increase in alpha cell number. It is unknown whether the regenerative process is causally related to the inflammatory infiltration in PDL-tails. Human pancreases with inflammatory infiltration also exhibited activation of proliferation in small beta cell clusters. CONCLUSIONS/SIGNIFICANCE: The PDL model illustrates the advantage of direct beta cell counts over beta cell mass measurements when assessing and localizing beta cell regeneration in the pancreas. It demonstrates the ability of the adult mouse pancreas for neogenesis of small beta cell clusters with activated beta cell proliferation. Further studies should investigate conditions under which neoformed small beta cell clusters grow to larger aggregates and hence to higher total beta cell numbers.

  4. GLP-1 derivative liraglutide in rats with beta-cell deficiencies: influence of metabolic state on beta-cell mass dynamics

    DEFF Research Database (Denmark)

    Sturis, Jeppe; Gotfredsen, Carsten F; Rømer, John

    2003-01-01

    (1) Liraglutide is a long-acting GLP-1 derivative, designed for once daily administration in type II diabetic patients. To investigate the effects of liraglutide on glycemic control and beta-cell mass in rat models of beta-cell deficiencies, studies were performed in male Zucker diabetic fatty (Z...... antihyperglycemic effects in rodent models of beta-cell deficiencies, and the in vivo effect of liraglutide on beta-cell mass may in part depend on the metabolic state of the animals....

  5. Regulation of pancreatic islet beta-cell mass by growth factor and hormone signaling.

    Science.gov (United States)

    Huang, Yao; Chang, Yongchang

    2014-01-01

    Dysfunction and destruction of pancreatic islet beta cells is a hallmark of diabetes. Better understanding of cellular signals in beta cells will allow development of therapeutic strategies for diabetes, such as preservation and expansion of beta-cell mass and improvement of beta-cell function. During the past several decades, the number of studies analyzing the molecular mechanisms, including growth factor/hormone signaling pathways that impact islet beta-cell mass and function, has increased exponentially. Notably, somatolactogenic hormones including growth hormone (GH), prolactin (PRL), and insulin-like growth factor-1 (IGF-1) and their receptors (GHR, PRLR, and IGF-1R) are critically involved in beta-cell growth, survival, differentiation, and insulin secretion. In this chapter, we focus more narrowly on GH, PRL, and IGF-1 signaling, and GH-IGF-1 cross talk. We also discuss how these signaling aspects contribute to the regulation of beta-cell proliferation and apoptosis. In particular, our novel findings of GH-induced formation of GHR-JAK2-IGF-1R protein complex and synergistic effects of GH and IGF-1 on beta-cell signaling, proliferation, and antiapoptosis lead to a new concept that IGF-1R may serve as a proximal component of GH/GHR signaling. © 2014 Elsevier Inc. All rights reserved.

  6. Beta Cell Mass Restoration in Alloxan-Diabetic Mice Treated with EGF and Gastrin.

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    Imane Song

    Full Text Available One week of treatment with EGF and gastrin (EGF/G was shown to restore normoglycemia and to induce islet regeneration in mice treated with the diabetogenic agent alloxan. The mechanisms underlying this regeneration are not fully understood. We performed genetic lineage tracing experiments to evaluate the contribution of beta cell neogenesis in this model. One day after alloxan administration, mice received EGF/G treatment for one week. The treatment could not prevent the initial alloxan-induced beta cell mass destruction, however it did reverse glycemia to control levels within one day, suggesting improved peripheral glucose uptake. In vitro experiments with C2C12 cell line showed that EGF could stimulate glucose uptake with an efficacy comparable to that of insulin. Subsequently, EGF/G treatment stimulated a 3-fold increase in beta cell mass, which was partially driven by neogenesis and beta cell proliferation as assessed by beta cell lineage tracing and BrdU-labeling experiments, respectively. Acinar cell lineage tracing failed to show an important contribution of acinar cells to the newly formed beta cells. No appearance of transitional cells co-expressing insulin and glucagon, a hallmark for alpha-to-beta cell conversion, was found, suggesting that alpha cells did not significantly contribute to the regeneration. An important fraction of the beta cells significantly lost insulin positivity after alloxan administration, which was restored to normal after one week of EGF/G treatment. Alloxan-only mice showed more pronounced beta cell neogenesis and proliferation, even though beta cell mass remained significantly depleted, suggesting ongoing beta cell death in that group. After one week, macrophage infiltration was significantly reduced in EGF/G-treated group compared to the alloxan-only group. Our results suggest that EGF/G-induced beta cell regeneration in alloxan-diabetic mice is driven by beta cell neogenesis, proliferation and recovery of

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

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    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.

  8. Role of growth factors in control of pancreatic beta cell mass: focus on betatrophin.

    Science.gov (United States)

    Levitsky, Lynne L; Ardestani, Goli; Rhoads, David B

    2014-08-01

    Betatrophin is a newly described hormone, which potently stimulates beta cell replication in mice. This discovery has engendered great hope that it could prove clinically important in the treatment of type 1 and type 2 diabetes. Betatrophin, a 198-amino acid protein secreted by liver and adipose tissue, stimulates growth of pancreatic beta cell mass in insulin-resistant mice. Betatrophin has previously been named RIFL, lipasin, and ANGPLT8, and its salutory effects on lipid metabolism have been described in mouse and human studies. Serum betatrophin levels in humans correlate with improved adipose tissue lipid storage and lower serum triglyceride levels in the fed state, but do not correlate with insulin resistance or carbohydrate tolerance in humans. Betatrophin has not yet been shown to have an effect on beta cell replication in human pancreatic islets. Many endocrine and paracrine factors, of which betatrophin is the newest described, increase beta cell mass in murine models. None of these factors, including betatrophin, have displayed the same activity in clinical studies. This may reflect a profound species difference in beta cell regeneration pathways in mice and humans.

  9. Glucagon-like peptide-1 receptor agonist treatment reduces beta cell mass in normoglycaemic mice

    NARCIS (Netherlands)

    Ellenbroek, J.H.; Tons, H.A.; Westerouen van Meeteren, M.J.; de Graaf, N.; Hanegraaf, M.A.; Rabelink, T.J.; Carlotti, F.; de Koning, E.J.

    2013-01-01

    AIMS/HYPOTHESIS: Incretin-based therapies improve glycaemic control in patients with type 2 diabetes. In animal models of diabetes, glucagon-like peptide-1 receptor agonists (GLP-1RAs) increase beta cell mass. GLP-1RAs are also evaluated in non-diabetic individuals with obesity and cardiovascular

  10. Pancreatic beta-cell overexpression of the glucagon receptor gene results in enhanced beta-cell function and mass

    DEFF Research Database (Denmark)

    Gelling, Richard W; Vuguin, Patricia M; Du, Xiu Quan

    2009-01-01

    in vivo, we generated mice overexpressing the Gcgr specifically on pancreatic beta-cells (RIP-Gcgr). In vivo and in vitro insulin secretion in response to glucagon and glucose was increased 1.7- to 3.9-fold in RIP-Gcgr mice compared with controls. Consistent with the observed increase in insulin release...

  11. Regulation of beta cell replication

    DEFF Research Database (Denmark)

    Lee, Ying C; Nielsen, Jens Høiriis

    2008-01-01

    Beta cell mass, at any given time, is governed by cell differentiation, neogenesis, increased or decreased cell size (cell hypertrophy or atrophy), cell death (apoptosis), and beta cell proliferation. Nutrients, hormones and growth factors coupled with their signalling intermediates have been...... suggested to play a role in beta cell mass regulation. In addition, genetic mouse model studies have indicated that cyclins and cyclin-dependent kinases that determine cell cycle progression are involved in beta cell replication, and more recently, menin in association with cyclin-dependent kinase...... inhibitors has been demonstrated to be important in beta cell growth. In this review, we consider and highlight some aspects of cell cycle regulation in relation to beta cell replication. The role of cell cycle regulation in beta cell replication is mostly from studies in rodent models, but whether...

  12. Islet neuropeptide Y receptors are functionally conserved and novel targets for the preservation of beta-cell mass.

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    Franklin, Zara J; Tsakmaki, Anastasia; Fonseca Pedro, Patricia; King, Aileen J; Huang, Guo Cai; Amjad, Sakeena; Persaud, Shanta J; Bewick, Gavin A

    2018-03-01

    Two unmet therapeutic strategies for diabetes treatment are prevention of beta-cell death and stimulation of beta-cell replication. Our aim was to characterize the role of neuropeptide Y receptors in the control of beta-cell mass. We used endogenous and selective agonists of the NPY receptor system to explore its role in the prevention of beta-cell apoptosis and proliferation in islets isolated from both mouse and human donors. We further explored the intra-cellular signalling cascades involved, using chemical inhibitors of key signalling pathways. As proof of principle we designed a long-acting analogue of [Leu 31 Pro 34 ]-NPY, an agonist of the islet-expressed Y receptors, to determine if targeting this system could preserve beta-cell mass in vivo. Our data reveal that NPY Y1, 4 and 5 receptor activation engages a generalized and powerful anti-apoptotic pathway that protects mouse and human islets from damage. These anti-apoptotic effects were dependent on stimulating a Gαi-PLC-PKC signalling cascade, which prevented cytokine-induced NFkB signalling. NPY receptor activation functionally protected islets by restoring glucose responsiveness following chemically induced injury in both species. NPY receptor activation attenuated beta-cell apoptosis, preserved functional beta-cell mass and attenuated the hyperglycaemic phenotype in a low-dose streptozotocin model of diabetes. Taken together, our observations identify the islet Y receptors as promising targets for the preservation of beta-cell mass. As such, targeting these receptors could help to maintain beta-cell mass in both type 1 and type 2 diabetes, and may also be useful for improving islet transplantation outcomes. © 2017 John Wiley & Sons Ltd.

  13. Early peroxisome proliferator-activated receptor gamma regulated genes involved in expansion of pancreatic beta cell mass

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    Vivas Yurena

    2011-12-01

    Full Text Available Abstract Background The progression towards type 2 diabetes depends on the allostatic response of pancreatic beta cells to synthesise and secrete enough insulin to compensate for insulin resistance. The endocrine pancreas is a plastic tissue able to expand or regress in response to the requirements imposed by physiological and pathophysiological states associated to insulin resistance such as pregnancy, obesity or ageing, but the mechanisms mediating beta cell mass expansion in these scenarios are not well defined. We have recently shown that ob/ob mice with genetic ablation of PPARγ2, a mouse model known as the POKO mouse failed to expand its beta cell mass. This phenotype contrasted with the appropriate expansion of the beta cell mass observed in their obese littermate ob/ob mice. Thus, comparison of these models islets particularly at early ages could provide some new insights on early PPARγ dependent transcriptional responses involved in the process of beta cell mass expansion Results Here we have investigated PPARγ dependent transcriptional responses occurring during the early stages of beta cell adaptation to insulin resistance in wild type, ob/ob, PPARγ2 KO and POKO mice. We have identified genes known to regulate both the rate of proliferation and the survival signals of beta cells. Moreover we have also identified new pathways induced in ob/ob islets that remained unchanged in POKO islets, suggesting an important role for PPARγ in maintenance/activation of mechanisms essential for the continued function of the beta cell. Conclusions Our data suggest that the expansion of beta cell mass observed in ob/ob islets is associated with the activation of an immune response that fails to occur in POKO islets. We have also indentified other PPARγ dependent differentially regulated pathways including cholesterol biosynthesis, apoptosis through TGF-β signaling and decreased oxidative phosphorylation.

  14. Development of biomarker specific of pancreatic beta cells (incretin radiolabelled) for image of beta functional mass in diabetic and obese: study in animal model

    International Nuclear Information System (INIS)

    Seo, Daniele

    2017-01-01

    Increased prevalence of obesity worldwide, has become a vast concern, stimulating investigations focusing prevention and therapy of this condition. The association of type 2 diabetes or insulin resistance aggravates the prognosis of obesity. Even patients successfully submitted to bariatric or metabolic surgery, may not be cured of diabetes, as improvement of circulating values of glucose and insulin not necessarily reflects recovery of pancreatic beta cell mass. There is no consensus about how to estimate beta cell mass in vivo. Available tools suffer from low sensitivity and specificity, often being as well cumbersome and expensive. Radiolabeled incretins, such as glucagon-like-peptide 1 (GLP-1) analogs, seem to be promising options for the measurement of beta cell mass in diabetes and insulinoma. The objective of this study was the development of two conjugates of GLP-1 analog, radiolabeled with 99m Technetium, as a noninvasive imaging method for the estimation of pancreatic beta cell mass, in the presence of obesity. Animal models were selected, including hyperlipidic diet-induced obesity, diet restricted obesity, and as controls, alloxan diabetes. Results indicated that both radiotracers achieved over 97% radiochemical yield. The most successful product was 99m Tc-HYNIC-βAla-Exendin-4. Low beta cell mass uptake occurred in diet-induced obesity. Diet-restricted obesity, with substantial shedding of excess body weight, was followed by remarkable decrease of fasting blood glucose, however beta cell mass uptake was only mildly improved. Future studies are recommended in obesity, type 2 diabetes, and dieting, including bariatric and metabolic operations. (author)

  15. Functional Beta Cell Mass from Device-Encapsulated hESC-Derived Pancreatic Endoderm Achieving Metabolic Control

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    Thomas Robert

    2018-03-01

    Full Text Available Summary: Human stem cells represent a potential source for implants that replace the depleted functional beta cell mass (FBM in diabetes patients. Human embryonic stem cell-derived pancreatic endoderm (hES-PE can generate implants with glucose-responsive beta cells capable of reducing hyperglycemia in mice. This study with device-encapsulated hES-PE (4 × 106 cells/mouse determines the biologic characteristics at which implants establish metabolic control during a 50-week follow-up. A metabolically adequate FBM was achieved by (1 formation of a sufficient beta cell number (>0.3 × 106/mouse at >50% endocrine purity and (2 their maturation to a functional state comparable with human pancreatic beta cells, as judged by their secretory responses during perifusion, their content in typical secretory vesicles, and their nuclear NKX6.1-PDX1-MAFA co-expression. Assessment of FBM in implants and its correlation with in vivo metabolic markers will guide clinical translation of stem cell-derived grafts in diabetes. : In this article, Pipeleers and colleagues demonstrate that subcutaneous implants of device-encapsulated human stem cell-derived pancreatic endoderm can generate a functional beta cell mass that establishes sustained glucose control in mice. They identified their biologic characteristics and correlation with in vivo outcome. Data and methods are expected to guide clinical translation to beta cell replacement therapy in diabetes. Keywords: stem cell-derived pancreatic endoderm, stem cell therapy, diabetes, encapsulation, differentiation, functional maturation, functional beta cell mass, metabolic control

  16. Effect of Hypertriglyceridemia on Beta Cell Mass and Function in ApoC3 Transgenic Mice.

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    Liu, Yun-Zi; Cheng, Xiaoyun; Zhang, Ting; Lee, Sojin; Yamauchi, Jun; Xiao, Xiangwei; Gittes, George; Qu, Shen; Jiang, Chun-Lei; Dong, H Henry

    2016-07-08

    Hypertriglyceridemia results from increased production and decreased clearance of triglyceride-rich very low-density lipoproteins, a pathological condition that accounts for heightened risk of ischemic vascular diseases in obesity and type 2 diabetes. Despite its intimate association with insulin resistance, whether hypertriglyceridemia constitutes an independent risk for beta cell dysfunction in diabetes is unknown. Answering this fundamental question is stymied by the fact that hypertriglyceridemia is intertwined with hyperglycemia and insulin resistance in obese and diabetic subjects. To circumvent this limitation, we took advantage of apolipoprotein C3 (ApoC3)-transgenic mice, a model with genetic predisposition to hypertriglyceridemia. We showed that ApoC3-transgenic mice, as opposed to age/sex-matched wild-type littermates, develop hypertriglyceridemia with concomitant elevations in plasma cholesterol and non-esterified fatty acid levels. Anti-insulin and anti-glucagon dual immunohistochemistry in combination with morphometric analysis revealed that ApoC3-transgenic and wild-type littermates had similar beta cell and alpha cell masses as well as islet size and architecture. These effects correlated with similar amplitudes of glucose-stimulated insulin secretion and similar degrees of postprandial glucose excursion in ApoC3-transgenic versus wild-type littermates. Oil Red O histology did not visualize lipid infiltration into islets, correlating with the lack of ectopic triglyceride and cholesterol depositions in the pancreata of ApoC3-transgenic versus wild-type littermates. ApoC3-transgenic mice, despite persistent hypertriglyceridemia, maintained euglycemia under both fed and fasting conditions without manifestation of insulin resistance and fasting hyperinsulinemia. Thus, hypertriglyceridemia per se is not an independent risk factor for beta cell dysfunction in ApoC3 transgenic mice. © 2016 by The American Society for Biochemistry and Molecular Biology

  17. Beta cell adaptation in pregnancy

    DEFF Research Database (Denmark)

    Nielsen, Jens Høiriis

    2016-01-01

    Pregnancy is associated with a compensatory increase in beta cell mass. It is well established that somatolactogenic hormones contribute to the expansion both indirectly by their insulin antagonistic effects and directly by their mitogenic effects on the beta cells via receptors for prolactin...... and growth hormone expressed in rodent beta cells. However, the beta cell expansion in human pregnancy seems to occur by neogenesis of beta cells from putative progenitor cells rather than by proliferation of existing beta cells. Claes Hellerström has pioneered the research on beta cell growth for decades......, but the mechanisms involved are still not clarified. In this review the information obtained in previous studies is recapitulated together with some of the current attempts to resolve the controversy in the field: identification of the putative progenitor cells, identification of the factors involved...

  18. Islet autoimmunity identifies a unique pattern of impaired pancreatic beta-cell function, markedly reduced pancreatic beta cell mass and insulin resistance in clinically diagnosed type 2 diabetes.

    Directory of Open Access Journals (Sweden)

    Angela Subauste

    Full Text Available There is a paucity of literature describing metabolic and histological data in adult-onset autoimmune diabetes. This subgroup of diabetes mellitus affects at least 5% of clinically diagnosed type 2 diabetic patients (T2DM and it is termed Latent Autoimmune Diabetes in Adults (LADA. We evaluated indexes of insulin secretion, metabolic assessment, and pancreatic pathology in clinically diagnosed T2DM patients with and without the presence of humoral islet autoimmunity (Ab. A total of 18 patients with at least 5-year duration of clinically diagnosed T2DM were evaluated in this study. In those subjects we assessed acute insulin responses to arginine, a glucose clamp study, whole-body fat mass and fat-free mass. We have also analyzed the pancreatic pathology of 15 T2DM and 43 control cadaveric donors, using pancreatic tissue obtained from all the T2DM organ donors available from the nPOD network through December 31, 2013. The presence of islet Ab correlated with severely impaired β-cell function as demonstrated by remarkably low acute insulin response to arginine (AIR when compared to that of the Ab negative group. Glucose clamp studies indicated that both Ab positive and Ab negative patients exhibited peripheral insulin resistance in a similar fashion. Pathology data from T2DM donors with Ab or the autoimmune diabetes associated DR3/DR4 allelic class II combination showed reduction in beta cell mass as well as presence of autoimmune-associated pattern A pathology in subjects with either islet autoantibodies or the DR3/DR4 genotype. In conclusion, we provide compelling evidence indicating that islet Ab positive long-term T2DM patients exhibit profound impairment of insulin secretion as well as reduced beta cell mass seemingly determined by an immune-mediated injury of pancreatic β-cells. Deciphering the mechanisms underlying beta cell destruction in this subset of diabetic patients may lead to the development of novel immunologic therapies aimed at

  19. Islet autoimmunity identifies a unique pattern of impaired pancreatic beta-cell function, markedly reduced pancreatic beta cell mass and insulin resistance in clinically diagnosed type 2 diabetes.

    Science.gov (United States)

    Subauste, Angela; Gianani, Roberto; Chang, Annette M; Plunkett, Cynthia; Pietropaolo, Susan L; Zhang, Ying-Jian; Barinas-Mitchell, Emma; Kuller, Lewis H; Galecki, Andrzej; Halter, Jeffrey B; Pietropaolo, Massimo

    2014-01-01

    There is a paucity of literature describing metabolic and histological data in adult-onset autoimmune diabetes. This subgroup of diabetes mellitus affects at least 5% of clinically diagnosed type 2 diabetic patients (T2DM) and it is termed Latent Autoimmune Diabetes in Adults (LADA). We evaluated indexes of insulin secretion, metabolic assessment, and pancreatic pathology in clinically diagnosed T2DM patients with and without the presence of humoral islet autoimmunity (Ab). A total of 18 patients with at least 5-year duration of clinically diagnosed T2DM were evaluated in this study. In those subjects we assessed acute insulin responses to arginine, a glucose clamp study, whole-body fat mass and fat-free mass. We have also analyzed the pancreatic pathology of 15 T2DM and 43 control cadaveric donors, using pancreatic tissue obtained from all the T2DM organ donors available from the nPOD network through December 31, 2013. The presence of islet Ab correlated with severely impaired β-cell function as demonstrated by remarkably low acute insulin response to arginine (AIR) when compared to that of the Ab negative group. Glucose clamp studies indicated that both Ab positive and Ab negative patients exhibited peripheral insulin resistance in a similar fashion. Pathology data from T2DM donors with Ab or the autoimmune diabetes associated DR3/DR4 allelic class II combination showed reduction in beta cell mass as well as presence of autoimmune-associated pattern A pathology in subjects with either islet autoantibodies or the DR3/DR4 genotype. In conclusion, we provide compelling evidence indicating that islet Ab positive long-term T2DM patients exhibit profound impairment of insulin secretion as well as reduced beta cell mass seemingly determined by an immune-mediated injury of pancreatic β-cells. Deciphering the mechanisms underlying beta cell destruction in this subset of diabetic patients may lead to the development of novel immunologic therapies aimed at halting the

  20. Regulation of pancreatic beta-cell mass and proliferation by SOCS-3

    DEFF Research Database (Denmark)

    Lindberg, K; Rønn, S G; Tornehave, D

    2005-01-01

    ) signaling pathway. Suppressors of cytokine signaling (SOCS) proteins are specific inhibitors of the JAK/STAT pathway acting through a negative-feedback loop. To investigate in vivo effects of SOCS-3 in growth hormone (GH)/prolactin signaling in beta-cells we generated transgenic mice with beta...... tyrosine phosphorylation of STAT-5 when compared with wild-type islets. Transduction of primary islet cultures with adenoviruses expressing various SOCS proteins followed by stimulation with GH or glucagon-like peptide-1 (GLP-1) revealed that SOCS-3 inhibited GH- but not GLP-1-mediated islet cell...

  1. The long-acting GLP-1 derivative NN2211 ameliorates glycemia and increases beta-cell mass in diabetic mice

    DEFF Research Database (Denmark)

    Rolin, Bidda; Larsen, Marianne O; Gotfredsen, Carsten F

    2002-01-01

    NN2211 is a long-acting, metabolically stable glucagon-like peptide-1 (GLP-1) derivative designed for once daily administration in humans. NN2211 dose dependently reduced the glycemic levels in ob/ob mice, with antihyperglycemic activity still evident 24 h postdose. Apart from an initial reduction...... in food intake, there were no significant differences between NN2211 and vehicle treatment, and body weight was not affected. Histological examination revealed that beta-cell proliferation and mass were not increased significantly in ob/ob mice with NN2211, although there was a strong tendency...... for increased proliferation. In db/db mice, exendin-4 and NN2211 decreased blood glucose compared with vehicle, but NN2211 had a longer duration of action. Food intake was lowered only on day 1 with both compounds, and body weight was unaffected. beta-Cell proliferation rate and mass were significantly...

  2. Targeted inactivation of hepatocyte growth factor receptor c-met in beta-cells leads to defective insulin secretion and GLUT-2 downregulation without alteration of beta-cell mass.

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    Roccisana, Jennifer; Reddy, Vasumathi; Vasavada, Rupangi C; Gonzalez-Pertusa, Jose A; Magnuson, Mark A; Garcia-Ocaña, Adolfo

    2005-07-01

    Overexpression of hepatocyte growth factor (HGF) in the beta-cell of transgenic mice enhances beta-cell proliferation, survival, and function. In the current studies, we have used conditional ablation of the c-met gene to uncover the physiological role of HGF in beta-cell growth and function. Mice in which c-met is inactivated in the beta-cell (MetCKO mice) display normal body weight, blood glucose, and plasma insulin compared with control littermates. In contrast, MetCKO mice displayed significantly diminished glucose tolerance and reduced plasma insulin after a glucose challenge in vivo. This impaired glucose tolerance in MetCKO mice was not caused by insulin resistance because sensitivity to exogenous insulin was similar in both groups. Importantly, in vitro glucose-stimulated insulin secretion in MetCKO islets was decreased by approximately 50% at high glucose concentrations compared with control islets. Furthermore, whereas insulin and glucokinase expression in MetCKO islets were normal, GLUT-2 expression was decreased by approximately 50%. These changes in beta-cell function in MetCKO mice were not accompanied by changes in total beta-cell mass, islet morphology, islet cell composition, and beta-cell proliferation. Interestingly, however, MetCKO mice display an increased number of small islets, mainly single and doublet beta-cells. We conclude that HGF/c-met signaling in the beta-cell is not essential for beta-cell growth, but it is essential for normal glucose-dependent insulin secretion.

  3. Autophagy protects pancreatic beta cell mass and function in the setting of a high-fat and high-glucose diet.

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    Sheng, Qingfeng; Xiao, Xiangwei; Prasadan, Krishna; Chen, Congde; Ming, Yungching; Fusco, Joseph; Gangopadhyay, Nupur N; Ricks, David; Gittes, George K

    2017-11-27

    Autophagy is a major regulator of pancreatic beta cell homeostasis. Altered autophagic activity has been implicated in the beta cells of patients with type 2 diabetes, and in the beta cells of obese diabetic rodents. Here, we show that autophagy was induced in beta cells by either a high-fat diet or a combined high-fat and high-glucose diet, but not by high-glucose alone. However, a high-glucose intake alone did increase beta cell mass and insulin secretion moderately. Depletion of Atg7, a necessary component of the autophagy pathway, in beta cells by pancreatic intra-ductal AAV8-shAtg7 infusion in C57BL/6 mice, resulted in decreased beta cell mass, impaired glucose tolerance, defective insulin secretion, and increased apoptosis when a combined high-fat and high-glucose diet was given, seemingly due to suppression of autophagy. Taken together, our findings suggest that the autophagy pathway may act as a protective mechanism in pancreatic beta cells during a high-calorie diet.

  4. 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

  5. Intermittent fasting preserves beta-cell mass in obesity-induced diabetes via the autophagy-lysosome pathway.

    Science.gov (United States)

    Liu, Haiyan; Javaheri, Ali; Godar, Rebecca J; Murphy, John; Ma, Xiucui; Rohatgi, Nidhi; Mahadevan, Jana; Hyrc, Krzysztof; Saftig, Paul; Marshall, Connie; McDaniel, Michael L; Remedi, Maria S; Razani, Babak; Urano, Fumihiko; Diwan, Abhinav

    2017-01-01

    Obesity-induced diabetes is characterized by hyperglycemia, insulin resistance, and progressive beta cell failure. In islets of mice with obesity-induced diabetes, we observe increased beta cell death and impaired autophagic flux. We hypothesized that intermittent fasting, a clinically sustainable therapeutic strategy, stimulates autophagic flux to ameliorate obesity-induced diabetes. Our data show that despite continued high-fat intake, intermittent fasting restores autophagic flux in islets and improves glucose tolerance by enhancing glucose-stimulated insulin secretion, beta cell survival, and nuclear expression of NEUROG3, a marker of pancreatic regeneration. In contrast, intermittent fasting does not rescue beta-cell death or induce NEUROG3 expression in obese mice with lysosomal dysfunction secondary to deficiency of the lysosomal membrane protein, LAMP2 or haplo-insufficiency of BECN1/Beclin 1, a protein critical for autophagosome formation. Moreover, intermittent fasting is sufficient to provoke beta cell death in nonobese lamp2 null mice, attesting to a critical role for lysosome function in beta cell homeostasis under fasting conditions. Beta cells in intermittently-fasted LAMP2- or BECN1-deficient mice exhibit markers of autophagic failure with accumulation of damaged mitochondria and upregulation of oxidative stress. Thus, intermittent fasting preserves organelle quality via the autophagy-lysosome pathway to enhance beta cell survival and stimulates markers of regeneration in obesity-induced diabetes.

  6. Species-specific vesicular monoamine transporter 2 (VMAT2) expression in mammalian pancreatic beta cells: implications for optimising radioligand-based human beta cell mass (BCM) imaging in animal models.

    Science.gov (United States)

    Schäfer, M K-H; Hartwig, N R; Kalmbach, N; Klietz, M; Anlauf, M; Eiden, L E; Weihe, E

    2013-05-01

    Imaging of beta cell mass (BCM) is a major challenge in diabetes research. The vesicular monoamine transporter 2 (VMAT2) is abundantly expressed in human beta cells. Radiolabelled analogues of tetrabenazine (TBZ; a low-molecular-weight, cell-permeant VMAT2-selective ligand) have been employed for pancreatic islet imaging in humans. Since reports on TBZ-based VMAT2 imaging in rodent pancreas have been fraught with confusion, we compared VMAT2 gene expression patterns in the mouse, rat, pig and human pancreas, to identify appropriate animal models with which to further validate and optimise TBZ imaging in humans. We used a panel of highly sensitive VMAT2 antibodies developed against equivalently antigenic regions of the transporter from each species in combination with immunostaining for insulin and species-specific in situ hybridisation probes. Individual pancreatic islets were obtained by laser-capture microdissection and subjected to analysis of mRNA expression of VMAT2. The VMAT2 protein was not expressed in beta cells in the adult pancreas of common mouse or rat laboratory strains, in contrast to its expression in beta cells (but not other pancreatic endocrine cell types) in the pancreas of pigs and humans. VMAT2- and tyrosine hydroxylase co-positive (catecholaminergic) innervation was less abundant in humans than in rodents. VMAT2-positive mast cells were identified in the pancreas of all species. Primates and pigs are suitable models for TBZ imaging of beta cells. Rodents, because of a complete lack of VMAT2 expression in the endocrine pancreas, are a 'null' model for assessing interference with BCM measurements by VMAT2-positive mast cells and sympathetic innervation in the pancreas.

  7. Early deficits in insulin secretion, beta cell mass and islet blood perfusion precede onset of autoimmune type 1 diabetes in BioBreeding rats.

    Science.gov (United States)

    Medina, Anya; Parween, Saba; Ullsten, Sara; Vishnu, Neelanjan; Siu, Yuk Ting; Quach, My; Bennet, Hedvig; Balhuizen, Alexander; Åkesson, Lina; Wierup, Nils; Carlsson, Per Ola; Ahlgren, Ulf; Lernmark, Åke; Fex, Malin

    2018-04-01

    Genetic studies show coupling of genes affecting beta cell function to type 1 diabetes, but hitherto no studies on whether beta cell dysfunction could precede insulitis and clinical onset of type 1 diabetes are available. We used 40-day-old BioBreeding (BB) DRLyp/Lyp rats (a model of spontaneous autoimmune type 1 diabetes) and diabetes-resistant DRLyp/+ and DR+/+ littermates (controls) to investigate beta cell function in vivo, and insulin and glucagon secretion in vitro. Beta cell mass was assessed by optical projection tomography (OPT) and morphometry. Additionally, measurements of intra-islet blood flow were performed using microsphere injections. We also assessed immune cell infiltration, cytokine expression in islets (by immunohistochemistry and qPCR), as well as islet Glut2 expression and ATP/ADP ratio to determine effects on glucose uptake and metabolism in beta cells. DRLyp/Lyp rats were normoglycaemic and without traces of immune cell infiltrates. However, IVGTTs revealed a significant decrease in the acute insulin response to glucose compared with control rats (1685.3 ± 121.3 vs 633.3 ± 148.7; p beta cell ATP/ADP ratio in DRLyp/Lyp rats vs control rats. The present study identifies a deterioration of beta cell function and mass, and intra-islet blood flow that precedes insulitis and diabetes development in animals prone to autoimmune type 1 diabetes. These underlying changes in islet function may be previously unrecognised factors of importance in type 1 diabetes development.

  8. Development of biomarker specific of pancreatic beta cells (incretin radiolabelled) for image of beta functional mass in diabetic and obese: study in animal model; Desenvolvimento de biomarcador específico de células beta pancreáticas (incretina radiomarcada) para imagem da massa beta funcional em diabéticos e obesos: estudo em modelo animal

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Daniele

    2017-07-01

    Increased prevalence of obesity worldwide, has become a vast concern, stimulating investigations focusing prevention and therapy of this condition. The association of type 2 diabetes or insulin resistance aggravates the prognosis of obesity. Even patients successfully submitted to bariatric or metabolic surgery, may not be cured of diabetes, as improvement of circulating values of glucose and insulin not necessarily reflects recovery of pancreatic beta cell mass. There is no consensus about how to estimate beta cell mass in vivo. Available tools suffer from low sensitivity and specificity, often being as well cumbersome and expensive. Radiolabeled incretins, such as glucagon-like-peptide 1 (GLP-1) analogs, seem to be promising options for the measurement of beta cell mass in diabetes and insulinoma. The objective of this study was the development of two conjugates of GLP-1 analog, radiolabeled with {sup 99m} Technetium, as a noninvasive imaging method for the estimation of pancreatic beta cell mass, in the presence of obesity. Animal models were selected, including hyperlipidic diet-induced obesity, diet restricted obesity, and as controls, alloxan diabetes. Results indicated that both radiotracers achieved over 97% radiochemical yield. The most successful product was {sup 99m}Tc-HYNIC-βAla-Exendin-4. Low beta cell mass uptake occurred in diet-induced obesity. Diet-restricted obesity, with substantial shedding of excess body weight, was followed by remarkable decrease of fasting blood glucose, however beta cell mass uptake was only mildly improved. Future studies are recommended in obesity, type 2 diabetes, and dieting, including bariatric and metabolic operations. (author)

  9. Ciliary neurotrophic factor (CNTF) protects non-obese Swiss mice against type 2 diabetes by increasing beta cell mass and reducing insulin clearance.

    Science.gov (United States)

    Rezende, L F; Santos, G J; Santos-Silva, J C; Carneiro, E M; Boschero, A C

    2012-05-01

    Ciliary neurotrophic factor (CNTF) improves metabolic variables of obese animals with characteristics of type 2 diabetes, mainly by reducing insulin resistance. We evaluated whether CNTF was able to improve other metabolic variables in mouse models of type 2 diabetes, such as beta cell mass and insulin clearance, and whether CNTF has any effect on non-obese mice with characteristics of type 2 diabetes. Neonatal mice were treated with 0.1 mg/kg CNTF or citrate buffer via intraperitoneal injections, before injection of 250 mg/kg alloxan. HEPG2 cells were cultured for 3 days in the presence of citrate buffer, 1 nmol/l CNTF or 50 mmol/l alloxan or a combination of CNTF and alloxan. Twenty-one days after treatment, we determined body weight, epididymal fat weight, blood glucose, plasma insulin, NEFA, glucose tolerance, insulin resistance, insulin clearance and beta cell mass. Finally, we assessed insulin receptor and protein kinase B phosphorylation in peripheral organs, as well as insulin-degrading enzyme (IDE) protein production and alternative splicing in the liver and HEPG2 cells. CNTF improved insulin sensitivity and beta cell mass, while reducing glucose-stimulated insulin secretion and insulin clearance in Swiss mice, improving glucose handling in a non-obese type 2 diabetes model. This effect was associated with lower IDE production and activity in liver cells. All these effects were observed even at 21 days after CNTF treatment. CNTF protection against type 2 diabetes is partially independent of the anti-obesity actions of CNTF, requiring a reduction in insulin clearance and increased beta cell mass, besides increased insulin sensitivity. Furthermore, knowledge of the long-term effects of CNTF expands its pharmacological relevance.

  10. Valine pyrrolidide preserves intact glucose-dependent insulinotropic peptide and improves abnormal glucose tolerance in minipigs with reduced beta-cell mass

    DEFF Research Database (Denmark)

    Larsen, Marianne Olholm; Rolin, Bidda; Ribel, Ulla

    2003-01-01

    for type 2 diabetes was evaluated in a new large animal model of insulin-deficient diabetes and reduced beta-cell mass, the nicotinamide (NIA) (67 mg/kg) and streptozotocin (STZ) (125 mg/kg)-treated minipig, using the DPPIV inhibitor, valine pyrrolidide (VP) (50 mg/kg). VP did not significantly affect...... glucose tolerance test (OGTT) but increased the insulinogenic index in normal animals (from 83 +/- 42 to 192 +/- 108; P animals. GIP seems to contribute to the antihyperglycemic effect of VP in this model...

  11. Chemical Methods to Induce Beta-Cell Proliferation

    Directory of Open Access Journals (Sweden)

    Amedeo Vetere

    2012-01-01

    Full Text Available Pancreatic beta-cell regeneration, for example, by inducing proliferation, remains an important goal in developing effective treatments for diabetes. However, beta cells have mainly been considered quiescent. This “static” view has recently been challenged by observations of relevant physiological conditions in which metabolic stress is compensated by an increase in beta-cell mass. Understanding the molecular mechanisms underlining these process could open the possibility of developing novel small molecules to increase beta-cell mass. Several cellular cell-cycle and signaling proteins provide attractive targets for high throughput screening, and recent advances in cell culture have enabled phenotypic screening for small molecule-induced beta-cell proliferation. We present here an overview of the current trends involving small-molecule approaches to induce beta-cell regeneration by proliferation.

  12. Double beta decays and neutrino masses

    International Nuclear Information System (INIS)

    Ejiri, Hiro

    2006-01-01

    Neutrino-less double beta decays(0νββ) are of great interest for studying the Majorana nature of ν's and the absolute ν-mass scale. The present report is a brief review of the 0νββ studies with emphasis on future experiments with the mass sensitivity of an order of 25∼100 meV and on experimental probes for investigating 0νββ nuclear matrix elements

  13. Progress in molecular nuclear medicine imaging of pancreatic beta cells

    International Nuclear Information System (INIS)

    Wu Haifei; Yin Hongyan; Liu Shuai; Zhang Yifan

    2010-01-01

    Diabetes mellitus is a common and frequently occurring disease which seriously threaten the health of human beings. Type 1 and type 2 diabetes respectively results from being destroyed and insufficient beta-cell mass. The associated symptoms appear until 50%-60% decrease of beta-cell mass. Because pancreas is deeply located in the body, with few beta-cell mass, the current methods of clinical diagnosis are invasive and late. So diagnosis of metabolism disease of beta-cell early non-invasively becomes more and more popular, imaging diagnosis of diabetes mellitus becomes the focus of researches, but how to estimate the mass of beta-cell still an important subject in imaging technology. (authors)

  14. Beta Cell Workshop 2013 Kyoto

    DEFF Research Database (Denmark)

    Heller, R Scott; Madsen, Ole D; Nielsen, Jens Høiriis

    2013-01-01

    The very modern Kyoto International Conference Center provided the site for the 8th workshop on Beta cells on April 23-26, 2013. The preceding workshops were held in Boston, USA (1991); Kyoto, Japan (1994); Helsingør, Denmark (1997); Helsinki, Finland (2003); El Perello, Spain (2006); Peebles...

  15. Beta Cell Breakthroughs

    Science.gov (United States)

    ... enough islets into a patient to achieve insulin independence." The so-called "Edmonton protocol" has some major ... in response to Melton's article in Cell, Baylor College of Medicine researcher Jake Kushner, MD, argued that ...

  16. Pancreatic Fat Is Associated With Metabolic Syndrome and Visceral Fat but Not Beta-Cell Function or Body Mass Index in Pediatric Obesity.

    Science.gov (United States)

    Staaf, Johan; Labmayr, Viktor; Paulmichl, Katharina; Manell, Hannes; Cen, Jing; Ciba, Iris; Dahlbom, Marie; Roomp, Kirsten; Anderwald, Christian-Heinz; Meissnitzer, Matthias; Schneider, Reinhard; Forslund, Anders; Widhalm, Kurt; Bergquist, Jonas; Ahlström, Håkan; Bergsten, Peter; Weghuber, Daniel; Kullberg, Joel

    2017-03-01

    Adolescents with obesity have increased risk of type 2 diabetes and metabolic syndrome (MetS). Pancreatic fat has been related to these conditions; however, little is known about associations in pediatric obesity. The present study was designed to explore these associations further. We examined 116 subjects, 90 with obesity. Anthropometry, MetS, blood samples, and oral glucose tolerance tests were assessed using standard techniques. Pancreatic fat fraction (PFF) and other fat depots were quantified using magnetic resonance imaging. The PFF was elevated in subjects with obesity. No association between PFF and body mass index-standard deviation score (BMI-SDS) was found in the obesity subcohort. Pancreatic fat fraction correlated to Insulin Secretion Sensitivity Index-2 and Homeostatic Model Assessment of Insulin Resistance in simple regression; however, when using adjusted regression and correcting for BMI-SDS and other fat compartments, PFF correlated only to visceral adipose tissue and fasting glucose. Highest levels of PFF were found in subjects with obesity and MetS. In adolescents with obesity, PFF is elevated and associated to MetS, fasting glucose, and visceral adipose tissue but not to beta-cell function, glucose tolerance, or BMI-SDS. This study demonstrates that conclusions regarding PFF and its associations depend on the body mass features of the cohort.

  17. Clusters of conserved beta cell marker genes for assessment of beta cell phenotype

    DEFF Research Database (Denmark)

    Martens, Geert A; Jiang, Lei; Hellemans, Karine H

    2011-01-01

    The aim of this study was to establish a gene expression blueprint of pancreatic beta cells conserved from rodents to humans and to evaluate its applicability to assess shifts in the beta cell differentiated state. Genome-wide mRNA expression profiles of isolated beta cells were compared to those...... microdissected beta cells, monitor adaptations of the beta cell phenotype to fasting, and retrieve possible conserved transcriptional regulators....

  18. Glucose regulates rat beta cell number through age-dependent effects on beta cell survival and proliferation.

    Directory of Open Access Journals (Sweden)

    Zerihun Assefa

    Full Text Available BACKGROUND: Glucose effects on beta cell survival and DNA-synthesis suggest a role as regulator of beta cell mass but data on beta cell numbers are lacking. We examined outcome of these influences on the number of beta cells isolated at different growth stages in their population. METHODS: Beta cells from neonatal, young-adult and old rats were cultured serum-free for 15 days. Their number was counted by automated whole-well imaging distinguishing influences on cell survival and on proliferative activity. RESULTS: Elevated glucose (10-20 versus 5 mmol/l increased the number of living beta cells from 8-week rats to 30%, following a time- and concentration-dependent recruitment of quiescent cells into DNA-synthesis; a glucokinase-activator lowered the threshold but did not raise total numbers of glucose-recruitable cells. No glucose-induced increase occurred in beta cells from 40-week rats. Neonatal beta cells doubled in number at 5 mmol/l involving a larger activated fraction that did not increase at higher concentrations; however, their higher susceptibility to glucose toxicity at 20 mmol/l resulted in 20% lower living cell numbers than at start. None of the age groups exhibited a repetitively proliferating subpopulation. CONCLUSIONS: Chronically elevated glucose levels increased the number of beta cells from young-adult but not from old rats; they interfered with expansion of neonatal beta cells and reduced their number. These effects are attributed to age-dependent differences in basal and glucose-induced proliferative activity and in cellular susceptibility to glucose toxicity. They also reflect age-dependent variations in the functional heterogeneity of the rat beta cell population.

  19. Glucose Regulates Rat Beta Cell Number through Age-Dependent Effects on Beta Cell Survival and Proliferation

    Science.gov (United States)

    Steyaert, Christophe; Stangé, Geert; Martens, Geert A.; Ling, Zhidong; Hellemans, Karine; Pipeleers, Daniel

    2014-01-01

    Background Glucose effects on beta cell survival and DNA-synthesis suggest a role as regulator of beta cell mass but data on beta cell numbers are lacking. We examined outcome of these influences on the number of beta cells isolated at different growth stages in their population. Methods Beta cells from neonatal, young-adult and old rats were cultured serum-free for 15 days. Their number was counted by automated whole-well imaging distinguishing influences on cell survival and on proliferative activity. Results Elevated glucose (10–20 versus 5 mmol/l) increased the number of living beta cells from 8-week rats to 30%, following a time- and concentration-dependent recruitment of quiescent cells into DNA-synthesis; a glucokinase-activator lowered the threshold but did not raise total numbers of glucose-recruitable cells. No glucose-induced increase occurred in beta cells from 40-week rats. Neonatal beta cells doubled in number at 5 mmol/l involving a larger activated fraction that did not increase at higher concentrations; however, their higher susceptibility to glucose toxicity at 20 mmol/l resulted in 20% lower living cell numbers than at start. None of the age groups exhibited a repetitively proliferating subpopulation. Conclusions Chronically elevated glucose levels increased the number of beta cells from young-adult but not from old rats; they interfered with expansion of neonatal beta cells and reduced their number. These effects are attributed to age-dependent differences in basal and glucose-induced proliferative activity and in cellular susceptibility to glucose toxicity. They also reflect age-dependent variations in the functional heterogeneity of the rat beta cell population. PMID:24416358

  20. Reduction in placental growth factor impaired gestational beta-cell proliferation through crosstalk between beta-cells and islet endothelial cells.

    Science.gov (United States)

    Xu, Xiaosheng; Shen, Jian

    2016-01-01

    Reduced placental growth factor (PLGF) during pregnancy is known to be a reason for developing preeclampsia (PE) and gestational diabetes mellitus (GDM), but the underlying mechanisms remain unclear. Recently, it has been shown that reduced PLGF may induce GDM through suppressing beta-cell mass growth in a PI3k/Akt signalling-dependent manner. Here, we dissected the interaction between beta-cells and islet endothelial cells in this model. We analysed proliferation of beta-cells and islet endothelial cells at different time points of gestation in mice. We cultured mouse islet endothelial cells (MS1), with or without PLGF. We cultured primary mouse beta-cells in conditioned media from PLGF-treated MS1. We cultured MS1 cells in conditioned media from proliferating beta-cells that were activated with conditioned media from PLGF-treated MS1 cells. We analysed cell proliferation by BrdU incorporation. We analysed cell growth by a MTT assay. We found that during mouse gestation, the increases in cell proliferation occurred earlier in beta-cells than in islet endothelial cells. In vitro, PLGF itself failed to induce proliferation of MS1 cells. However, conditioned media from the PLGF-treated MS1 cells induced beta-cell proliferation, resulting in increases in beta-cell number. Moreover, proliferation of MS1 cells significantly increased when MS1 cells were cultured in conditioned media from proliferating beta-cells activated with conditioned media from PLGF-treated MS1 cells. Thus, our data suggest that gestational PLGF may stimulate islet endothelial cells to release growth factors to promote beta-cell proliferation, and proliferating beta-cells in turn release endothelial cell growth factor to increase proliferation of endothelial cells. PE-associated reduction in PLGF impairs these processes to result in islet growth impairment, and subsequently the onset of GDM.

  1. Beta cell proliferation and growth factors

    DEFF Research Database (Denmark)

    Nielsen, Jens Høiriis; Svensson, C; Møldrup, Annette

    1999-01-01

    cloned a novel GH/PRL stimulated rat islet gene product, Pref-1 (preadipocyte factor-1). This protein contains six EGF-like motifs and may play a role both in embryonic pancreas differentiation and in beta cell growth and function. In summary, the increasing knowledge about the mechanisms involved...... in beta cell differentiation and proliferation may lead to new ways of forming beta cells for treatment of diabetes in man....

  2. Clusters of conserved beta cell marker genes for assessment of beta cell phenotype

    DEFF Research Database (Denmark)

    Martens, Geert A; Jiang, Lei; Hellemans, Karine H

    2011-01-01

    The aim of this study was to establish a gene expression blueprint of pancreatic beta cells conserved from rodents to humans and to evaluate its applicability to assess shifts in the beta cell differentiated state. Genome-wide mRNA expression profiles of isolated beta cells were compared to those...

  3. Clusters of conserved beta cell marker genes for assessment of beta cell phenotype

    DEFF Research Database (Denmark)

    Martens, Geert A; Jiang, Lei; Hellemans, Karine H

    2011-01-01

    The aim of this study was to establish a gene expression blueprint of pancreatic beta cells conserved from rodents to humans and to evaluate its applicability to assess shifts in the beta cell differentiated state. Genome-wide mRNA expression profiles of isolated beta cells were compared to those...... of a large panel of other tissue and cell types, and transcripts with beta cell-abundant and -selective expression were identified. Iteration of this analysis in mouse, rat and human tissues generated a panel of conserved beta cell biomarkers. This panel was then used to compare isolated versus laser capture...... microdissected beta cells, monitor adaptations of the beta cell phenotype to fasting, and retrieve possible conserved transcriptional regulators....

  4. Beta cell proliferation and growth factors

    DEFF Research Database (Denmark)

    Nielsen, Jens Høiriis; Svensson, C; Møldrup, Annette

    1999-01-01

    cloned a novel GH/PRL stimulated rat islet gene product, Pref-1 (preadipocyte factor-1). This protein contains six EGF-like motifs and may play a role both in embryonic pancreas differentiation and in beta cell growth and function. In summary, the increasing knowledge about the mechanisms involved......Formation of new beta cells can take place by two pathways: replication of already differentiated beta cells or neogenesis from putative islet stem cells. Under physiological conditions both processes are most pronounced during the fetal and neonatal development of the pancreas. In adulthood little...

  5. Positron emission tomography study on pancreatic somatostatin receptors in normal and diabetic rats with {sup 68}Ga-DOTA-octreotide: A potential PET tracer for beta cell mass measurement

    Energy Technology Data Exchange (ETDEWEB)

    Sako, Takeo [Division of Bio-function Dynamics Imaging, RIKEN Center for Life Science Technologies, 6-7-3 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047 (Japan); Division of Molecular Imaging, Institute of Biomedical Research and Innovation, 2-2 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047 (Japan); Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe, Hyogo 650-0017 (Japan); Hasegawa, Koki; Nishimura, Mie; Kanayama, Yousuke; Wada, Yasuhiro; Hayashinaka, Emi; Cui, Yilong; Kataoka, Yosky [Division of Bio-function Dynamics Imaging, RIKEN Center for Life Science Technologies, 6-7-3 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047 (Japan); Senda, Michio [Division of Bio-function Dynamics Imaging, RIKEN Center for Life Science Technologies, 6-7-3 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047 (Japan); Division of Molecular Imaging, Institute of Biomedical Research and Innovation, 2-2 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047 (Japan); Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe, Hyogo 650-0017 (Japan); Watanabe, Yasuyoshi, E-mail: yywata@riken.jp [Division of Bio-function Dynamics Imaging, RIKEN Center for Life Science Technologies, 6-7-3 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047 (Japan)

    2013-12-06

    Highlights: •PET images showed high uptake of {sup 68}Ga-DOTA-octreotide in the normal pancreas. •{sup 68}Ga-DOTA-octreotide specifically binds to somatostatin receptors in the pancreas. •The pancreatic uptake of {sup 68}Ga-DOTA-octreotide was decreased in the diabetic rats. •{sup 68}Ga-DOTA-octreotide could be a candidate PET probe to measure the beta cell mass. -- Abstract: Diabetes mellitus (DM) is a metabolic disorder characterized by hyperglycemia, and the loss or dysfunction of pancreatic beta cells has been reported before the appearance of clinical symptoms and hyperglycemia. To evaluate beta cell mass (BCM) for improving the detection and treatment of DM at earlier stages, we focused on somatostatin receptors that are highly expressed in the pancreatic beta cells, and developed a positron emission tomography (PET) probe derived from octreotide, a metabolically stable somatostatin analog. Octreotide was conjugated with 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA), a chelating agent, and labeled with {sup 68}Gallium ({sup 68}Ga). After intravenous injection of {sup 68}Ga-DOTA-octreotide, a 90-min emission scan of the abdomen was performed in normal and DM model rats. The PET studies showed that {sup 68}Ga-DOTA-octreotide radioactivity was highly accumulated in the pancreas of normal rats and that the pancreatic accumulation was significantly reduced in the rats administered with an excess amount of unlabeled octreotide or after treatment with streptozotocin, which was used for the chemical induction of DM in rats. These results were in good agreement with the ex vivo biodistribution data. These results indicated that the pancreatic accumulation of {sup 68}Ga-DOTA-octreotide represented specific binding to the somatostatin receptors and reflected BCM. Therefore, PET imaging with {sup 68}Ga-DOTA-octreotide could be a potential tool for evaluating BCM.

  6. Exploring functional beta-cell heterogeneity in vivo using PSA-NCAM as a specific marker.

    Directory of Open Access Journals (Sweden)

    Melis Karaca

    Full Text Available BACKGROUND: The mass of pancreatic beta-cells varies according to increases in insulin demand. It is hypothesized that functionally heterogeneous beta-cell subpopulations take part in this process. Here we characterized two functionally distinct groups of beta-cells and investigated their physiological relevance in increased insulin demand conditions in rats. METHODS: Two rat beta-cell populations were sorted by FACS according to their PSA-NCAM surface expression, i.e. beta(high and beta(low-cells. Insulin release, Ca(2+ movements, ATP and cAMP contents in response to various secretagogues were analyzed. Gene expression profiles and exocytosis machinery were also investigated. In a second part, beta(high and beta(low-cell distribution and functionality were investigated in animal models with decreased or increased beta-cell function: the Zucker Diabetic Fatty rat and the 48 h glucose-infused rat. RESULTS: We show that beta-cells are heterogeneous for PSA-NCAM in rat pancreas. Unlike beta(low-cells, beta(high-cells express functional beta-cell markers and are highly responsive to various insulin secretagogues. Whereas beta(low-cells represent the main population in diabetic pancreas, an increase in beta(high-cells is associated with gain of function that follows sustained glucose overload. CONCLUSION: Our data show that a functional heterogeneity of beta-cells, assessed by PSA-NCAM surface expression, exists in vivo. These findings pinpoint new target populations involved in endocrine pancreas plasticity and in beta-cell defects in type 2 diabetes.

  7. Unexpected presence of fructan 6-exohydrolases (6-FEHs) in non-fructan plants: characterization, cloning, mass mapping and functional analysis of a novel "cell-wall invertase-like" specific 6-FEH from sugar beet (Beta vulgaris L.).

    Science.gov (United States)

    Van den Ende, Wim; De Coninck, Barbara; Clerens, Stefan; Vergauwen, Rudy; Van Laere, André

    2003-12-01

    About 15% of flowering plant species synthesize fructans. Fructans serve mainly as reserve carbohydrates and are subject to breakdown by plant fructan exohydrolases (FEHs), among which 1-FEHs (inulinases) and 6-FEHs (levanases) can be differentiated. This paper describes the unexpected finding that 6-FEHs also occur in plants that do not synthesize fructans. The purification, characterization, cloning and functional analysis of sugar beet (Beta vulgaris L.) 6-FEH are described. Enzyme activity measurements during sugar beet development suggest a constitutive expression of the gene in sugar beet roots. Classical enzyme purification followed by in-gel trypsin digestion and mass spectrometry (quadruple-time-of-flight mass spectrometry (Q-TOF) MS) led to peptide sequence information used in subsequent RT-PCR based cloning. Levan-type fructans (beta-2,6) are the best substrates for the enzyme, while inulin-type fructans (beta-2,1) and sucrose are poorly or not degraded. Sugar beet 6-FEH is more related to cell wall invertases than to vacuolar invertases and has a low iso-electric point (pI), clearly different from typical high pI cell wall invertases. Poor sequence homology to bacterial or fungal FEHs makes an endophytic origin highly unlikely. The functionality of the 6-FEH cDNA was further demonstrated by heterologous expression in Pichia pastoris. As fructans are absent in sugar beet, the role of 6-FEH in planta is not obvious. Like chitinases and beta-glucanases hydrolysing cell-surface components of fungal plant pathogens, a straightforward working hypothesis for further research might be that plant 6-FEHs participate in hydrolysis (or prevent the formation) of levan-containing slime surrounding endophytic or phytopathogenic bacteria.

  8. 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.

  9. The Fas pathway is involved in pancreatic beta cell secretory function

    DEFF Research Database (Denmark)

    Schumann, Desiree M; Maedler, Kathrin; Franklin, Isobel

    2007-01-01

    Pancreatic beta cell mass and function increase in conditions of enhanced insulin demand such as obesity. Failure to adapt leads to diabetes. The molecular mechanisms controlling this adaptive process are unclear. Fas is a death receptor involved in beta cell apoptosis or proliferation, depending...... on the activity of the caspase-8 inhibitor FLIP. Here we show that the Fas pathway also regulates beta cell secretory function. We observed impaired glucose tolerance in Fas-deficient mice due to a delayed and decreased insulin secretory pattern. Expression of PDX-1, a beta cell-specific transcription factor...... regulating insulin gene expression and mitochondrial metabolism, was decreased in Fas-deficient beta cells. As a consequence, insulin and ATP production were severely reduced and only partly compensated for by increased beta cell mass. Up-regulation of FLIP enhanced NF-kappaB activity via NF...

  10. Both conditional ablation and overexpression of E2 SUMO-conjugating enzyme (UBC9) in mouse pancreatic beta cells result in impaired beta cell function.

    Science.gov (United States)

    He, Xiaoyu; Lai, Qiaohong; Chen, Cai; Li, Na; Sun, Fei; Huang, Wenting; Zhang, Shu; Yu, Qilin; Yang, Ping; Xiong, Fei; Chen, Zhishui; Gong, Quan; Ren, Boxu; Weng, Jianping; Eizirik, Décio L; Zhou, Zhiguang; Wang, Cong-Yi

    2018-04-01

    Post-translational attachment of a small ubiquitin-like modifier (SUMO) to the lysine (K) residue(s) of target proteins (SUMOylation) is an evolutionary conserved regulatory mechanism. This modification has previously been demonstrated to be implicated in the control of a remarkably versatile regulatory mechanism of cellular processes. However, the exact regulatory role and biological actions of the E2 SUMO-conjugating enzyme (UBC9)-mediated SUMOylation function in pancreatic beta cells has remained elusive. Inducible beta cell-specific Ubc9 (also known as Ube2i) knockout (KO; Ubc9 Δbeta ) and transgenic (Ubc9 Tg ) mice were employed to address the impact of SUMOylation on beta cell viability and functionality. Ubc9 deficiency or overexpression was induced at 8 weeks of age using tamoxifen. To study the mechanism involved, we closely examined the regulation of the transcription factor nuclear factor erythroid 2-related factor 2 (NRF2) through SUMOylation in beta cells. Upon induction of Ubc9 deficiency, Ubc9 Δbeta islets exhibited a 3.5-fold higher accumulation of reactive oxygen species (ROS) than Ubc9 f/f control islets. Islets from Ubc9 Δbeta mice also had decreased insulin content and loss of beta cell mass after tamoxifen treatment. Specifically, at day 45 after Ubc9 deletion only 40% of beta cell mass remained in Ubc9 Δbeta mice, while 90% of beta cell mass was lost by day 75. Diabetes onset was noted in some Ubc9 Δbeta mice 8 weeks after induction of Ubc9 deficiency and all mice developed diabetes by 10 weeks following tamoxifen treatment. In contrast, Ubc9 Tg beta cells displayed an increased antioxidant ability but impaired insulin secretion. Unlike Ubc9 Δbeta mice, which spontaneously developed diabetes, Ubc9 Tg mice preserved normal non-fasting blood glucose levels without developing diabetes. It was noted that SUMOylation of NRF2 promoted its nuclear expression along with enhanced transcriptional activity, thereby preventing ROS accumulation in

  11. Direct measurement of neutrino mass utilizing beta decay of tritium

    Energy Technology Data Exchange (ETDEWEB)

    Kawakami, Hirokane (Tokyo Univ., Tanashi (Japan). Inst. for Nuclear Study)

    1992-10-01

    Among elementary particles, neutrino is the queer, wondrous elementary particle that has asymmetric property, and in spite of strenuous efforts, its mass has not been determined. The mass value expected for electron neutrino is as extremely small as several tens eV, but its value may control the future of the space whether this vast space continues to expand as it is or turns to contract. Accordingly, it has become a very important subject for space physics as well as elementary particle physics. The mass of neutrino has been considered to be nearly zero, but in 1980, the USSR group gave the finite value of 14-46 eV for the first time. Since then, the experiments for verifying this result were begun in more than ten places in the world. The method of measuring the mass of neutrino is that by precisely measuring with a beta ray analyzer the vicinity of the maximum value in the continuous energy spectra of the electron beam emitted simultaneously with neutrinos in the beta decay of tritium, and determining the mass from its form. [pi][radical]2 type air core beta ray analyzer, beta ray source, electron detector, the comparison of the contents of the published experiments, and the results of measurement are reported. (K.I.).

  12. What are the potential benefits of clinical beta-cell imaging in diabetes mellitus?

    Science.gov (United States)

    Göke, Burkhard

    2010-05-01

    Previously, studies of the endocrine pancreatic beta-cell were mainly performed ex vivo by morphological means. This data supported the analysis of pathophysiological changes in the pancreatic islet during insults such as diabetes mellitus. Metabolic testing of the pancreatic islet by assaying hormone parameters such als plasma insulin or C-peptide combined with more or less sophisticated calculations allowed conclusions about states of insulin resistance or secretory failure. It also allowed certain correlations of endocrine function with beta-cell mass. Today, with firmer pathophysiological concepts about beta-cell failure, modern protocols of islet transplantation, and drugs on the market coming with promises of preservation or even expansion of beta-cell mass in diabetes mellitus it has become very attractive to search for tools measuring beta-cell mass, if possible even repeatingly in the same organism in vivo. From a clinical point of view, the potential of pancreatic beta-cell mass imaging technologies is looked upon with high expectations. Methodologically, the decisive question is whether it is likely that future beta-cell imaging will provide significant advantages over the metabolic methods already in hand. With new in vivo tools, studies of beta-cell mass and function may offer even new approaches stratifying patients to anti-diabetic therapies.

  13. Neutrino mass bounds from neutrinoless double beta-decays and ...

    Indian Academy of Sciences (India)

    2016-01-21

    Jan 21, 2016 ... Abstract. We investigate the way the total mass sum of neutrinos can be constrained from the neu- trinoless double beta-decay and cosmological probes with cosmic microwave background (CMBR), large-scale structures including 2dFGRS and SDSS datasets. First we discuss, in brief, the current status of ...

  14. Neutrino mass bounds from neutrinoless double beta-decays and ...

    Indian Academy of Sciences (India)

    2016-01-21

    Jan 21, 2016 ... We investigate the way the total mass sum of neutrinos can be constrained from the neutrinoless double beta-decay and cosmological probes with cosmic microwave background (CMBR), large-scale structures including 2dFGRS and SDSS datasets. First we discuss, in brief, the current status of neutrino ...

  15. Implications for the offspring of circulating factors involved in beta cell adaptation in pregnancy

    DEFF Research Database (Denmark)

    Nalla, Amarnadh; Ringholm, Lene; Søstrup, Birgitte

    2014-01-01

    OBJECTIVE: Several studies have shown an increase in beta cell mass during pregnancy. Somatolactogenic hormones are known to stimulate the proliferation of existing beta cells in rodents whereas the mechanism in humans is still unclear. We hypothesize that in addition to somatolactogenic hormones...

  16. Enhancing pancreatic Beta-cell regeneration in vivo with pioglitazone and alogliptin.

    Directory of Open Access Journals (Sweden)

    Hao Yin

    Full Text Available Pancreatic beta-cells retain limited ability to regenerate and proliferate after various physiologic triggers. Identifying therapies that are able to enhance beta-cell regeneration may therefore be useful for the treatment of both type 1 and type 2 diabetes.In this study we investigated endogenous and transplanted beta-cell regeneration by serially quantifying changes in bioluminescence from beta-cells from transgenic mice expressing firefly luciferase under the control of the mouse insulin I promoter. We tested the ability of pioglitazone and alogliptin, two drugs developed for the treatment of type 2 diabetes, to enhance beta-cell regeneration, and also defined the effect of the immunosuppression with rapamycin and tacrolimus on transplanted islet beta mass.Pioglitazone is a stimulator of nuclear receptor peroxisome proliferator-activated receptor gamma while alogliptin is a selective dipeptidyl peptidase IV inhibitor. Pioglitazone alone, or in combination with alogliptin, enhanced endogenous beta-cell regeneration in streptozotocin-treated mice, while alogliptin alone had modest effects. In a model of syngeneic islet transplantation, immunosuppression with rapamycin and tacrolimus induced an early loss of beta-cell mass, while treatment with insulin implants to maintain normoglycemia and pioglitazone plus alogliptin was able to partially promote beta-cell mass recovery.These data highlight the utility of bioluminescence for serially quantifying functional beta-cell mass in living mice. They also demonstrate the ability of pioglitazone, used either alone or in combination with alogliptin, to enhance regeneration of endogenous islet beta-cells as well as transplanted islets into recipients treated with rapamycin and tacrolimus.

  17. Majorana neutrino masses and the neutrinoless double-beta decay

    International Nuclear Information System (INIS)

    Faessler, A.

    2006-01-01

    Neutrinoless double-beta decay is forbidden in the Standard Model of electroweak and strong interaction but allowed in most Grand Unified Theories (GUTs). Only if the neutrino is a Majorana particle (identical with its antiparticle) and if it has a mass is neutrinoless double-beta decay allowed. Apart from one claim that the neutrinoless double-beta decay in 76 Ge is measured, one has only upper limits for this transition probability. But even the upper limits allow one to give upper limits for the electron Majorana neutrino mass and upper limits for parameters of GUTs and the minimal R-parity-violating supersymmetric model. One further can give lower limits for the vector boson mediating mainly the right-handed weak interaction and the heavy mainly right-handed Majorana neutrino in left-right symmetric GUTs. For that, one has to assume that the specific mechanism is the leading one for neutrinoless double-beta decay and one has to be able to calculate reliably the corresponding nuclear matrix elements. In the present work, one discusses the accuracy of the present status of calculating of the nuclear matrix elements and the corresponding limits of GUTs and supersymmetric parameters

  18. Redox Homeostasis in Pancreatic beta Cells

    Czech Academy of Sciences Publication Activity Database

    Ježek, Petr; Dlasková, Andrea; Plecitá-Hlavatá, Lydie

    2012-01-01

    Roč. 2012, č. 2012 (2012), s. 932838 ISSN 1942-0900 R&D Projects: GA ČR(CZ) GAP302/10/0346; GA ČR(CZ) GPP304/10/P204 Institutional support: RVO:67985823 Keywords : beta cells * reactive oxygen species homeostasis * mitochondria Subject RIV: FB - Endocrinology, Diabetology, Metabolism, Nutrition Impact factor: 3.393, year: 2012

  19. MST1 is a novel regulator of apoptosis in pancreatic beta-cells

    Science.gov (United States)

    Ardestani, Amin; Khobragade, Vrushali; Yuan, Ting; Frogne, Thomas; Tao, Wufan; Oberholzer, Jose; Pattou, Francois; Conte, Julie Kerr; Maedler, Kathrin

    2014-01-01

    Apoptotic cell death is a hallmark of the loss of insulin producing beta-cells in all forms of diabetes mellitus. Current treatment fails to halt the decline in functional beta-cell mass. Strategies to prevent beta-cell apoptosis and dysfunction are urgently needed. Here, we identified Mammalian Sterile 20-like kinase 1 (MST1) as a critical regulator of apoptotic beta-cell death and function. MST1 was strongly activated in beta-cells under diabetogenic conditions and correlated with beta-cell apoptosis. MST1 specifically induced the mitochondrial-dependent pathway of apoptosis in beta-cells through up-regulation of the BH3-only protein Bim. MST1 directly phosphorylated PDX1 at Thr11, resulting in its ubiquitination, degradation and impaired insulin secretion. Mst1 deficiency completely restored normoglycemia, beta-cell function and survival in vitro and in vivo. We show MST1 as novel pro-apoptotic kinase and key mediator of apoptotic signaling and beta-cell dysfunction, which may serve as target for the development of novel therapies for diabetes. PMID:24633305

  20. Uncovering Factors Related to Pancreatic Beta-Cell Function

    OpenAIRE

    Curran, Aoife M.; Ryan, Miriam F.; Drummond, Elaine; Gibney, Eileen R.; Gibney, Michael J.; Roche, Helen M.; Brennan, Lorraine

    2016-01-01

    Aim: The incidence of type 2 diabetes has increased rapidly on a global scale. Beta-cell dysfunction contributes to the overall pathogenesis of type 2 diabetes. However, factors contributing to beta-cell function are not clear. The aims of this study were (i) to identify factors related to pancreatic beta-cell function and (ii) to perform mechanistic studies in vitro. Methods: Three specific measures of beta-cell function were assessed for 110 participants who completed an oral glucose tolera...

  1. Beta-cell regeneration from vimentin+/MafB+ cells after STZ-induced extreme beta-cell ablation.

    Science.gov (United States)

    Cheng, Yu; Kang, Hongjun; Shen, Jing; Hao, Haojie; Liu, Jiejie; Guo, Yelei; Mu, Yiming; Han, Weidong

    2015-07-01

    Loss of functional beta-cells is fundamental in both type 1 and type 2 diabetes. In situ beta-cell regeneration therefore has garnered great interest as an approach to diabetes therapy. Here, after elimination of pre-existing beta cells by a single high-dose of streptozotocin (STZ), we demonstrated that a considerable amount of beta-like-cells was generated within 48 hrs. But the newly formed insulin producing cells failed to respond to glucose challenge at this time and diminished afterwards. Insulin treatment to normalize the glucose level protected the neogenic beta-like cells and the islet function was also gradually matured. Strikingly, intermediate cells lacking epithelial marker E-cadherin but expressing mesenchymal cell-specific marker vimentin appeared within 16 hrs following STZ exposure, which served as the major source of insulin-producing cells observed at 24 hrs. Moreover, these intermediate cells strongly expressed alpha-cell-specific marker MafB. In summary, the data presented here identified a novel intermediate cell type as beta-cell progenitors, showing mesenchymal cell feature as well as alpha-cell marker MafB. Our results might have important implications for efforts to stimulate beta-cell regeneration.

  2. NOX, NOX who is there?, The contribution of NADPH Oxidase to beta cell dysfunction.

    Directory of Open Access Journals (Sweden)

    David eTaylor-Fishwick

    2013-04-01

    Full Text Available Predictions of diabetes prevalence over the next decades warrant the aggressive discovery of new approaches to stop or reverse loss of functional beta cell mass. Beta cells are recognized to have a relatively high sensitivity to reactive oxygen species (ROS and become dysfunctional under oxidative stress conditions. New discoveries have identified NADPH oxidases in beta cells as contributors to elevated cellular ROS. Reviewed are recent reports that evidence a role for NADPH oxidase-1 (NOX-1 in beta cell dysfunction. NOX-1 is stimulated by inflammatory cytokines that are elevated in diabetes. First, regulation of cytokine-stimulated NOX-1 expression has been linked to inflammatory lipid mediators derived from 12-lipoxyganase activity. For the first time in beta cells these data integrate distinct pathways associated with beta cell dysfunction. Second, regulation of NOX-1 in beta cells involves feed-forward control linked to elevated ROS and Src-kinase activation. This potentially results in unbridled ROS generation and identifies candidate targets for pharmacologic intervention. Third, consideration is provided of new, first-in-class, selective inhibitors of NOX-1. These compounds could have an important role in assessing a disruption of NOX-1/ROS signaling as a new approach to preserve and protect beta cell mass in diabetes.

  3. NOX, NOX Who is There? The Contribution of NADPH Oxidase One to Beta Cell Dysfunction

    Science.gov (United States)

    Taylor-Fishwick, David A.

    2013-01-01

    Predictions of diabetes prevalence over the next decades warrant the aggressive discovery of new approaches to stop or reverse loss of functional beta cell mass. Beta cells are recognized to have a relatively high sensitivity to reactive oxygen species (ROS) and become dysfunctional under oxidative stress conditions. New discoveries have identified NADPH oxidases in beta cells as contributors to elevated cellular ROS. Reviewed are recent reports that evidence a role for NADPH oxidase-1 (NOX-1) in beta cell dysfunction. NOX-1 is stimulated by inflammatory cytokines that are elevated in diabetes. First, regulation of cytokine-stimulated NOX-1 expression has been linked to inflammatory lipid mediators derived from 12-lipoxygenase activity. For the first time in beta cells these data integrate distinct pathways associated with beta cell dysfunction. Second, regulation of NOX-1 in beta cells involves feed-forward control linked to elevated ROS and Src-kinase activation. This potentially results in unbridled ROS generation and identifies candidate targets for pharmacologic intervention. Third, consideration is provided of new, first-in-class, selective inhibitors of NOX-1. These compounds could have an important role in assessing a disruption of NOX-1/ROS signaling as a new approach to preserve and protect beta cell mass in diabetes. PMID:23565109

  4. Expression of transforming growth factor beta (TGF beta) receptors and expression of TGF beta 1, TGF beta 2 and TGF beta 3 in human small cell lung cancer cell lines

    DEFF Research Database (Denmark)

    Damstrup, L; Rygaard, K; Spang-Thomsen, M

    1993-01-01

    A panel of 21 small cell lung cancer cell (SCLC) lines were examined for the presence of Transforming growth factor beta receptors (TGF beta-r) and the expression of TGF beta mRNAs. By the radioreceptor assay we found high affinity receptors to be expressed in six cell lines. scatchard analysis......(r) = 65,000 and 90,000 and the betaglycan (type III) with M(r) = 280,000. Northern blotting showed expression of TGF beta 1 mRNA in ten, TGF beta 2 mRNA in two and TGF beta 3 mRNA in seven cell lines. Our results provide, for the first time, evidence that a large proportion of a broad panel of SCLC cell...... lines express TGF beta-receptors and also produce TGF beta mRNAs....

  5. Update on the Protective Molecular Pathways Improving Pancreatic Beta-Cell Dysfunction

    Directory of Open Access Journals (Sweden)

    Alessandra Puddu

    2013-01-01

    Full Text Available The primary function of pancreatic beta-cells is to produce and release insulin in response to increment in extracellular glucose concentrations, thus maintaining glucose homeostasis. Deficient beta-cell function can have profound metabolic consequences, leading to the development of hyperglycemia and, ultimately, diabetes mellitus. Therefore, strategies targeting the maintenance of the normal function and protecting pancreatic beta-cells from injury or death might be crucial in the treatment of diabetes. This narrative review will update evidence from the recently identified molecular regulators preserving beta-cell mass and function recovery in order to suggest potential therapeutic targets against diabetes. This review will also highlight the relevance for novel molecular pathways potentially improving beta-cell dysfunction.

  6. Involvement of dying beta cell originated messenger molecules in differentiation of pancreatic mesenchymal stem cells under glucotoxic and glucolipotoxic conditions.

    Science.gov (United States)

    Gezginci-Oktayoglu, Selda; Onay-Ucar, Evren; Sancar-Bas, Serap; Karatug-Kacar, Ayse; Arda, Emine S N; Bolkent, Sehnaz

    2018-05-01

    Beta cell mass regulation represents a critical issue for understanding and treatment of diabetes. The most important process in the development of diabetes is beta cell death, generally induced by glucotoxicity or glucolipotoxicity, and the regeneration mechanism of new beta cells that will replace dead beta cells is still not fully understood. The aim of this study was to investigate the generation mechanism of new beta cells by considering the compensation phase of type 2 diabetes mellitus. In this study, pancreatic islet derived mesenchymal stem cells (PI-MSCs) were isolated from adult rats and characterized. Then, beta cells isolated from rats were co-cultured with PI-MSCs and they were exposed to glucotoxicity, lipotoxicity and glucolipotoxicity conditions for 72 hr. As the results apoptotic and necrotic cell death were increased in both PI-MSCs and beta cells especially by the exposure of glucotoxic and glucolipotoxic conditions to the co-culture systems. Glucotoxicity induced-differentiated beta cells were functional due to their capability of insulin secretion in response to rising glucose concentrations. Moreover, beta cell proliferation was induced in the glucotoxicity-treated co-culture system whereas suppressed in lipotoxicity or glucolipotoxicity-treated co-culture systems. In addition, 11 novel proteins, that may release from dead beta cells and have the ability to stimulate PI-MSCs in the direction of differentiation, were determined in media of glucotoxicity or glucolipotoxicity-treated co-culture systems. In conclusion, these molecules were considered as important for understanding cellular mechanism of beta cell differentiation and diabetes. Thus, they may be potential targets for diagnosis and cellular or therapeutic treatment of diabetes. © 2017 Wiley Periodicals, Inc.

  7. Expression of transforming growth factor-beta (TGF-beta) receptors, TGF-beta 1 and TGF-beta 2 production and autocrine growth control in osteosarcoma cells

    NARCIS (Netherlands)

    Kloen, P.; Jennings, C. L.; Gebhardt, M. C.; Springfield, D. S.; Mankin, H. J.

    1994-01-01

    Transforming growth factor-beta (TGF-beta) is a polypeptide with multiple physiological functions. Isoforms of this growth factor have important roles in control of the cell cycle, in regulation of cell-cell interactions and in growth and development. Malignant transformation has been shown to be

  8. Stimulation of pancreatic beta-cell replication by incretins involves transcriptional induction of cyclin D1 via multiple signalling pathways

    DEFF Research Database (Denmark)

    Friedrichsen, Birgitte N; Neubauer, Nicole; Lee, Ying C

    2006-01-01

    The incretin hormones, glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP), have been suggested to act as beta-cell growth factors and may therefore be of critical importance for the maintenance of a proper beta-cell mass. We have investigated the molecular mechanis...

  9. Uncovering Factors Related to Pancreatic Beta-Cell Function.

    Science.gov (United States)

    Curran, Aoife M; Ryan, Miriam F; Drummond, Elaine; Gibney, Eileen R; Gibney, Michael J; Roche, Helen M; Brennan, Lorraine

    2016-01-01

    The incidence of type 2 diabetes has increased rapidly on a global scale. Beta-cell dysfunction contributes to the overall pathogenesis of type 2 diabetes. However, factors contributing to beta-cell function are not clear. The aims of this study were (i) to identify factors related to pancreatic beta-cell function and (ii) to perform mechanistic studies in vitro. Three specific measures of beta-cell function were assessed for 110 participants who completed an oral glucose tolerance test as part of the Metabolic Challenge Study. Anthropometric and biochemical parameters were assessed as potential modulators of beta-cell function. Subsequent in vitro experiments were performed using the BRIN-BD11 pancreatic beta-cell line. Validation of findings were performed in a second human cohort. Waist-to-hip ratio was the strongest anthropometric modulator of beta-cell function, with beta-coefficients of -0.33 (p = 0.001) and -0.30 (p = 0.002) for beta-cell function/homeostatic model assessment of insulin resistance (HOMA-IR), and disposition index respectively. Additionally, the resistin-to-adiponectin ratio (RA index) emerged as being strongly associated with beta-cell function, with beta-coefficients of -0.24 (p = 0.038) and -0.25 (p = 0.028) for beta-cell function/HOMA-IR, and disposition index respectively. Similar results were obtained using a third measure for beta-cell function. In vitro experiments revealed that the RA index was a potent regulator of acute insulin secretion where a high RA index (20ng ml-1 resistin, 5nmol l-1 g-adiponectin) significantly decreased insulin secretion whereas a low RA index (10ng ml-1 resistin, 10nmol l-1 g-adiponectin) significantly increased insulin secretion. The RA index was successfully validated in a second human cohort with beta-coefficients of -0.40 (p = 0.006) and -0.38 (p = 0.008) for beta-cell function/ HOMA-IR, and disposition index respectively. Waist-to-hip ratio and RA index were identified as significant modulators of

  10. Uncovering Factors Related to Pancreatic Beta-Cell Function.

    Directory of Open Access Journals (Sweden)

    Aoife M Curran

    Full Text Available The incidence of type 2 diabetes has increased rapidly on a global scale. Beta-cell dysfunction contributes to the overall pathogenesis of type 2 diabetes. However, factors contributing to beta-cell function are not clear. The aims of this study were (i to identify factors related to pancreatic beta-cell function and (ii to perform mechanistic studies in vitro.Three specific measures of beta-cell function were assessed for 110 participants who completed an oral glucose tolerance test as part of the Metabolic Challenge Study. Anthropometric and biochemical parameters were assessed as potential modulators of beta-cell function. Subsequent in vitro experiments were performed using the BRIN-BD11 pancreatic beta-cell line. Validation of findings were performed in a second human cohort.Waist-to-hip ratio was the strongest anthropometric modulator of beta-cell function, with beta-coefficients of -0.33 (p = 0.001 and -0.30 (p = 0.002 for beta-cell function/homeostatic model assessment of insulin resistance (HOMA-IR, and disposition index respectively. Additionally, the resistin-to-adiponectin ratio (RA index emerged as being strongly associated with beta-cell function, with beta-coefficients of -0.24 (p = 0.038 and -0.25 (p = 0.028 for beta-cell function/HOMA-IR, and disposition index respectively. Similar results were obtained using a third measure for beta-cell function. In vitro experiments revealed that the RA index was a potent regulator of acute insulin secretion where a high RA index (20ng ml-1 resistin, 5nmol l-1 g-adiponectin significantly decreased insulin secretion whereas a low RA index (10ng ml-1 resistin, 10nmol l-1 g-adiponectin significantly increased insulin secretion. The RA index was successfully validated in a second human cohort with beta-coefficients of -0.40 (p = 0.006 and -0.38 (p = 0.008 for beta-cell function/ HOMA-IR, and disposition index respectively.Waist-to-hip ratio and RA index were identified as significant modulators

  11. Neutrino masses and neutrinoless double-beta decay

    Energy Technology Data Exchange (ETDEWEB)

    Pavan, M. [Dipartimento di Fisica dell' Universita di Milano, Bicocca and sezioneINFN di Milano Bicocca (Italy)

    2008-12-15

    The potentials of Double Beta Decay experiments in the field of neutrino study are here discussed. Sensitivity and results are compared with the information coming from oscillation, cosmology and beta decay measurements. (Author)

  12. A study of beta decay energies and atomic masses

    International Nuclear Information System (INIS)

    Spanier, L.

    1988-04-01

    The q β energies of 123-131 In have been determined using the end points of β spectra recorded in β-γ coincidence experiments. A HPGe planar detector was used to detect the β-particles and a semi-empirical response function was used when unfolding the electron distribution. The mass excesses were deduced and when they were compared with the predictions of various mass formulae, the cadmium isotopes were found to be heavier than those predicted by most of the mass formulae. The excitation energy of the 1/2 - proton-hole state in the odd indium isotopes was shown to be constant for all the heavy isotopes. The Q EC energies of 148 Dy and 96 Pd were determined using the β + /EC intensity ratio method. The ratio of the intensity of the β+ branch to the total beta decay intensity was determined by means of γ-spectroscopic methods. The mass excesses were deduced. The two-proton binding energy for the N=82 isotones showed only a small step of approximately 0.5 MeV when the doubly-magic nucleus 146 Gd was encountered. A liquid drop type mass formula with deformation and shell energy corrections and with few free parameters is presented. The shell energy correction is a simple analytical expression for the equilibrium deformation of the nucleus. An analytical expression for the equilibrium nuclear deformation is also presented. The mass formula was applied to nuclei with Z and N greater than 50. The RMS deviation is 0.55 milli mass units. The reaction 98 Mo(p,n) 98 Tc was investigated through the counter ratio method, the ratio of the number of slow neutrons to the number of fast neutrons. The Q pn energy value of a low-spin state in 98 Tc was determined. The state at 90.9 keV excitation energy is proposed to be the 14.6 m u s isomer and have spin and parity 1 + . (author)

  13. Mechanisms of pancreatic beta-cell growth and regeneration

    DEFF Research Database (Denmark)

    Nielsen, Jens Høiriis

    1989-01-01

    Information about the mechanism of beta-cell growth and regeneration may be obtained by studies of insulinoma cells. In the present study the growth and function of the rat insulinoma cell lines RINm5F and 5AH were evaluated by addition of serum, hormones, and growth factors. It was found...... of insulin mRNA content showed that the insulinoma cells only contained about 2% of that of normal rat beta-cells. These results are discussed in relation to the role of growth factors, oncogenes, and differentiation in the growth and regeneration of beta-cells....

  14. Coherent dynamics of exciatable coupled beta-cells

    DEFF Research Database (Denmark)

    Sørensen, Mads P; Petersen, Mette Vesterager; Aslanidi, Oleg

    2004-01-01

    Propagation of excitation waves through a cluster of insulin-secreting beta-cells (a pancreatic islet of Langerhans) is modelled, and the results are related to recent image analysis experiments.......Propagation of excitation waves through a cluster of insulin-secreting beta-cells (a pancreatic islet of Langerhans) is modelled, and the results are related to recent image analysis experiments....

  15. Proteomic profiling of bone marrow mesenchymal stem cells upon TGF-beta stimulation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Daojing; Park, Jennifer S.; Chu, Julia S.F.; Ari, Krakowski; Luo, Kunxin; Chen, David J.; Li, Song

    2004-08-08

    Bone marrow mesenchymal stem cells (MSCs) can differentiate into different types of cells, and have tremendous potential for cell therapy and tissue engineering. Transforming growth factor {beta}1 (TGF-{beta}) plays an important role in cell differentiation and vascular remodeling. We showed that TGF-{beta} induced cell morphology change and an increase in actin fibers in MSCs. To determine the global effects of TGF-{beta} on MSCs, we employed a proteomic strategy to analyze the effect of TGF-{beta} on the human MSC proteome. By using two-dimensional gel electrophoresis and electrospray ionization coupled to Quadrupole/time-of-flight tandem mass spectrometers, we have generated a proteome reference map of MSCs, and identified {approx}30 proteins with an increase or decrease in expression or phosphorylation in response to TGF-{beta}. The proteins regulated by TGF-{beta} included cytoskeletal proteins, matrix synthesis proteins, membrane proteins, metabolic enzymes, etc. TGF-{beta} increased the expression of smooth muscle (SM) {alpha}-actin and decreased the expression of gelsolin. Over-expression of gelsolin inhibited TGF-{beta}-induced assembly of SM {alpha}-actin; on the other hand, knocking down gelsolin expression enhanced the assembly of {alpha}-actin and actin filaments without significantly affecting {alpha}-actin expression. These results suggest that TGF-{beta} coordinates the increase of {alpha}-actin and the decrease of gelsolin to promote MSC differentiation. This study demonstrates that proteomic tools are valuable in studying stem cell differentiation and elucidating the underlying molecular mechanisms.

  16. Hypothyroidism in utero stimulates pancreatic beta cell proliferation and hyperinsulinaemia in the ovine fetus during late gestation.

    Science.gov (United States)

    Harris, Shelley E; De Blasio, Miles J; Davis, Melissa A; Kelly, Amy C; Davenport, Hailey M; Wooding, F B Peter; Blache, Dominique; Meredith, David; Anderson, Miranda; Fowden, Abigail L; Limesand, Sean W; Forhead, Alison J

    2017-06-01

    Thyroid hormones are important regulators of growth and maturation before birth, although the extent to which their actions are mediated by insulin and the development of pancreatic beta cell mass is unknown. Hypothyroidism in fetal sheep induced by removal of the thyroid gland caused asymmetric organ growth, increased pancreatic beta cell mass and proliferation, and was associated with increased circulating concentrations of insulin and leptin. In isolated fetal sheep islets studied in vitro, thyroid hormones inhibited beta cell proliferation in a dose-dependent manner, while high concentrations of insulin and leptin stimulated proliferation. The developing pancreatic beta cell is therefore sensitive to thyroid hormone, insulin and leptin before birth, with possible consequences for pancreatic function in fetal and later life. The findings of this study highlight the importance of thyroid hormones during pregnancy for normal development of the fetal pancreas. Development of pancreatic beta cell mass before birth is essential for normal growth of the fetus and for long-term control of carbohydrate metabolism in postnatal life. Thyroid hormones are also important regulators of fetal growth, and the present study tested the hypotheses that thyroid hormones promote beta cell proliferation in the fetal ovine pancreatic islets, and that growth retardation in hypothyroid fetal sheep is associated with reductions in pancreatic beta cell mass and circulating insulin concentration in utero. Organ growth and pancreatic islet cell proliferation and mass were examined in sheep fetuses following removal of the thyroid gland in utero. The effects of triiodothyronine (T 3 ), insulin and leptin on beta cell proliferation rates were determined in isolated fetal ovine pancreatic islets in vitro. Hypothyroidism in the sheep fetus resulted in an asymmetric pattern of organ growth, pancreatic beta cell hyperplasia, and elevated plasma insulin and leptin concentrations. In pancreatic

  17. Detailed transcriptome atlas of the pancreatic beta cell

    Directory of Open Access Journals (Sweden)

    Eizirik Decio L

    2009-01-01

    Full Text Available Abstract Background Gene expression patterns provide a detailed view of cellular functions. Comparison of profiles in disease vs normal conditions provides insights into the processes underlying disease progression. However, availability and integration of public gene expression datasets remains a major challenge. The aim of the present study was to explore the transcriptome of pancreatic islets and, based on this information, to prepare a comprehensive and open access inventory of insulin-producing beta cell gene expression, the Beta Cell Gene Atlas (BCGA. Methods We performed Massively Parallel Signature Sequencing (MPSS analysis of human pancreatic islet samples and microarray analyses of purified rat beta cells, alpha cells and INS-1 cells, and compared the information with available array data in the literature. Results MPSS analysis detected around 7600 mRNA transcripts, of which around a third were of low abundance. We identified 2000 and 1400 transcripts that are enriched/depleted in beta cells compared to alpha cells and INS-1 cells, respectively. Microarray analysis identified around 200 transcription factors that are differentially expressed in either beta or alpha cells. We reanalyzed publicly available gene expression data and integrated these results with the new data from this study to build the BCGA. The BCGA contains basal (untreated conditions gene expression level estimates in beta cells as well as in different cell types in human, rat and mouse pancreas. Hierarchical clustering of expression profile estimates classify cell types based on species while beta cells were clustered together. Conclusion Our gene atlas is a valuable source for detailed information on the gene expression distribution in beta cells and pancreatic islets along with insulin producing cell lines. The BCGA tool, as well as the data and code used to generate the Atlas are available at the T1Dbase website (T1DBase.org.

  18. Detailed transcriptome atlas of the pancreatic beta cell.

    Science.gov (United States)

    Kutlu, Burak; Burdick, David; Baxter, David; Rasschaert, Joanne; Flamez, Daisy; Eizirik, Decio L; Welsh, Nils; Goodman, Nathan; Hood, Leroy

    2009-01-15

    Gene expression patterns provide a detailed view of cellular functions. Comparison of profiles in disease vs normal conditions provides insights into the processes underlying disease progression. However, availability and integration of public gene expression datasets remains a major challenge. The aim of the present study was to explore the transcriptome of pancreatic islets and, based on this information, to prepare a comprehensive and open access inventory of insulin-producing beta cell gene expression, the Beta Cell Gene Atlas (BCGA). We performed Massively Parallel Signature Sequencing (MPSS) analysis of human pancreatic islet samples and microarray analyses of purified rat beta cells, alpha cells and INS-1 cells, and compared the information with available array data in the literature. MPSS analysis detected around 7600 mRNA transcripts, of which around a third were of low abundance. We identified 2000 and 1400 transcripts that are enriched/depleted in beta cells compared to alpha cells and INS-1 cells, respectively. Microarray analysis identified around 200 transcription factors that are differentially expressed in either beta or alpha cells. We reanalyzed publicly available gene expression data and integrated these results with the new data from this study to build the BCGA. The BCGA contains basal (untreated conditions) gene expression level estimates in beta cells as well as in different cell types in human, rat and mouse pancreas. Hierarchical clustering of expression profile estimates classify cell types based on species while beta cells were clustered together. Our gene atlas is a valuable source for detailed information on the gene expression distribution in beta cells and pancreatic islets along with insulin producing cell lines. The BCGA tool, as well as the data and code used to generate the Atlas are available at the T1Dbase website (T1DBase.org).

  19. Feedback inhibition of CREB signaling promotes beta cell dysfunction in insulin resistance.

    Science.gov (United States)

    Blanchet, Emilie; Van de Velde, Sam; Matsumura, Shigenobu; Hao, Ergeng; LeLay, John; Kaestner, Klaus; Montminy, Marc

    2015-02-24

    Although persistent elevations in circulating glucose concentrations promote compensatory increases in pancreatic islet mass, unremitting insulin resistance causes deterioration in beta cell function that leads to the progression to diabetes. Here, we show that mice with a knockout of the CREB coactivator CRTC2 in beta cells have impaired oral glucose tolerance due to decreases in circulating insulin concentrations. CRTC2 was found to promote beta cell function in part by stimulating the expression of the transcription factor MafA. Chronic hyperglycemia disrupted cAMP signaling in pancreatic islets by activating the hypoxia inducible factor (HIF1)-dependent induction of the protein kinase A inhibitor beta (PKIB), a potent inhibitor of PKA catalytic activity. Indeed, disruption of the PKIB gene improved islet function in the setting of obesity. These results demonstrate how crosstalk between nutrient and hormonal pathways contributes to loss of pancreatic islet function. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  20. Visualization of human karyopherin beta-1/importin beta-1 interactions with protein partners in mitotic cells by co-immunoprecipitation and proximity ligation assays.

    Science.gov (United States)

    Di Francesco, Laura; Verrico, Annalisa; Asteriti, Italia Anna; Rovella, Paola; Cirigliano, Pietro; Guarguaglini, Giulia; Schininà, Maria Eugenia; Lavia, Patrizia

    2018-01-30

    Karyopherin beta-1/Importin beta-1 is a conserved nuclear transport receptor, acting in protein nuclear import in interphase and as a global regulator of mitosis. These pleiotropic functions reflect its ability to interact with, and regulate, different pathways during the cell cycle, operating as a major effector of the GTPase RAN. Importin beta-1 is overexpressed in cancers characterized by high genetic instability, an observation that highlights the importance of identifying its partners in mitosis. Here we present the first comprehensive profile of importin beta-1 interactors from human mitotic cells. By combining co-immunoprecipitation and proteome-wide mass spectrometry analysis of synchronized cell extracts, we identified expected (e.g., RAN and SUMO pathway factors) and novel mitotic interactors of importin beta-1, many with RNA-binding ability, that had not been previously associated with importin beta-1. These data complement interactomic studies of interphase transport pathways. We further developed automated proximity ligation assay (PLA) protocols to validate selected interactors. We succeeded in obtaining spatial and temporal resolution of genuine importin beta-1 interactions, which were visualized and localized in situ in intact mitotic cells. Further developments of PLA protocols will be helpful to dissect importin beta-1-orchestrated pathways during mitosis.

  1. Alternative splicing of TGF-betas and their high-affinity receptors T beta RI, T beta RII and T beta RIII (betaglycan) reveal new variants in human prostatic cells.

    Science.gov (United States)

    Konrad, Lutz; Scheiber, Jonas A; Völck-Badouin, Elke; Keilani, Marcel M; Laible, Leslie; Brandt, Heidrun; Schmidt, Ansgar; Aumüller, Gerhard; Hofmann, Rainer

    2007-09-11

    The transforming growth factors (TGF)-beta, TGF-beta1, TGF-beta2 and TGF-beta 3, and their receptors [T beta RI, T beta RII, T beta R III (betaglycan)] elicit pleiotropic functions in the prostate. Although expression of the ligands and receptors have been investigated, the splice variants have never been analyzed. We therefore have analyzed all ligands, the receptors and the splice variants T beta RIB, T beta RIIB and TGF-beta 2B in human prostatic cells. Interestingly, a novel human receptor transcript T beta RIIC was identified, encoding additional 36 amino acids in the extracellular domain, that is expressed in the prostatic cancer cells PC-3, stromal hPCPs, and other human tissues. Furthermore, the receptor variant T beta RIB with four additional amino acids was identified also in human. Expression of the variant T beta RIIB was found in all prostate cell lines studied with a preferential localization in epithelial cells in some human prostatic glands. Similarly, we observed localization of T beta RIIC and TGF-beta 2B mainly in the epithelial cells with a preferential localization of TGF-beta 2B in the apical cell compartment. Whereas in the androgen-independent hPCPs and PC-3 cells all TGF-beta ligands and receptors are expressed, the androgen-dependent LNCaP cells failed to express all ligands. Additionally, stimulation of PC-3 cells with TGF-beta2 resulted in a significant and strong increase in secretion of plasminogen activator inhibitor-1 (PAI-1) with a major participation of T beta RII. In general, expression of the splice variants was more heterogeneous in contrast to the well-known isoforms. The identification of the splice variants T beta RIB and the novel isoform T beta RIIC in man clearly contributes to the growing complexity of the TGF-beta family.

  2. The Path to Large-Mass Double Beta Decay Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, Steven R. [Los Alamos National Laboratory

    2012-08-08

    The technology is ready for atmospheric scale sensitivity and we can at least discuss it for the solar scale. Even null results will be interesting. Supporting measurements are important and have an impact. Need several mesurements with a total uncertainty (experiment and theory) of {approx} 50% or less, and eventually even better. If we see {beta}{beta} the qualitative physics results are profound, but next we'll want to quantify the underlying physics.

  3. On the coherent behavior of pancreatic beta cell clusters

    International Nuclear Information System (INIS)

    Loppini, Alessandro; Capolupo, Antonio; Cherubini, Christian; Gizzi, Alessio; Bertolaso, Marta; Filippi, Simonetta; Vitiello, Giuseppe

    2014-01-01

    Beta cells in pancreas represent an example of coupled biological oscillators which via communication pathways, are able to synchronize their electrical activity, giving rise to pulsatile insulin release. In this work we numerically analyze scale free self-similarity features of membrane voltage signal power density spectrum, through a stochastic dynamical model for beta cells in the islets of Langerhans fine tuned on mouse experimental data. Adopting the algebraic approach of coherent state formalism, we show how coherent molecular domains can arise from proper functional conditions leading to a parallelism with “phase transition” phenomena of field theory. - Highlights: • Beta cells in pancreas are coupled oscillators able to synchronize their activity. • We analyze scale free self-similarity features for beta cells. • We adopt the algebraic approach of coherent state formalism. • We show that coherent molecular domains arise from functional conditions

  4. Recent status of the studies of nuclear masses and {beta}-decay

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Masami [Waseda Univ., Tokyo (Japan). Advanced Research Center for Science and Engineering

    1996-05-01

    The recent status of the above studies was explained, especially, nuclear masses were described from the aspect of probability theory and that of {beta}-decay suggested that the first forbidden transition was hindered between the ground states. We have to study various systematics in order to know the mass surface, Way-Yamada-Matumoto type systematics is better to check the experimental nuclear masses. The gross theory is very useful to understand the general aspect of {beta}-decay. The understanding method of mass surface, systematic check of mass and hindrance of the first forbidden transition at rank 1 were explained. (S.Y.)

  5. Assessment of affinities of beta-CIT, beta-CIT-FE, and beta-CIT-FP for monoamine transporters permanently expressed in cell lines

    International Nuclear Information System (INIS)

    Okada, Tomoya; Fujita, Masahiro; Shimada, Shoichi; Sato, Kohji; Schloss, Patrick; Watanabe, Yoshiyuki; Itoh, Yasushi; Tohyama, Masaya; Nishimura, Tsunehiko

    1998-01-01

    We investigated the effects of three cocaine analogs, beta-CIT (2-beta-carbomethoxy-3-beta-(4-iodophenyl)-tropane), beta-CIT-FE (2-beta-carbomethoxy-3-beta-(4-iodophenyl)-N-(2-fluoroethyl)-nortropane), and beta-CIT-FP (2-beta-carbomethoxy-3-beta-(4-iodophenyl)-N-(3-fluoropropyl)-nortropane), on the uptake of [ 3 H]dopamine(DA), serotonin(5-HT), and 1-norepinephrine (NE) using cell lines permanently expressing DA, 5-HT, and NE transporters, respectively, to determine their affinities for these three transporters. We generated cell lines stably expressing DA, 5-HT, and NE transporters, respectively, by the Chen-Okayama method, and then tested the abilities of (-)cocaine, beta-CIT, beta-CIT-FE, beta-CIT-FP, and clomipramine to inhibit the uptake of [ 3 H]DA, 5-HT, and 1-NE. Ki values of beta-CIT, beta-CIT-FE, and beta-CIT-FP for [ 3 H]DA, 5-HT, 1-NE uptake were 6, 29, and 33 nM, 91, 133, and 130 nM, and 28, 113 and 70 nM, respectively, whereas those of cocaine and clomipramine were 316, 581, and 176 nM and > 10,000, 437, and 851 nM, respectively. Beta-CIT, beta-CIT-FE, and beta-CIT-FP were shown to be potent DA, 5-HT, and NE uptake inhibitors. Beta-CIT and beta-CIT-FP were highly potent and selective dopamine uptake inhibitors, and therefore might be useful for imaging of DA transporter with single photon emission computed tomography (SPECT) or positron emission tomography (PET)

  6. Mechanisms of pancreatic beta-cell growth and regeneration

    DEFF Research Database (Denmark)

    Nielsen, Jens Høiriis

    1989-01-01

    Information about the mechanism of beta-cell growth and regeneration may be obtained by studies of insulinoma cells. In the present study the growth and function of the rat insulinoma cell lines RINm5F and 5AH were evaluated by addition of serum, hormones, and growth factors. It was found...... that transferrin is the only obligatory factor whereas growth hormone, epidermal growth factor, fibroblast growth factor, and TRH had modulating effects. A heat-labile heparin binding serum factor which stimulated thymidine incorporation but not cell proliferation was demonstrated in human serum. Measurements...... of insulin mRNA content showed that the insulinoma cells only contained about 2% of that of normal rat beta-cells. These results are discussed in relation to the role of growth factors, oncogenes, and differentiation in the growth and regeneration of beta-cells....

  7. TGF-beta and 'adaptive' Foxp3(+) regulatory T cells.

    Science.gov (United States)

    Chen, Wanjun; Konkel, Joanne E

    2010-02-01

    In naïve T cells transforming growth factor-beta (TGF-beta) induces Foxp3, a transcription factor essential for programming and developing T regulatory cells (Treg cells). This finding reveals a physiological factor which can turn on the Foxp3 gene and establishes an experimental approach to induce antigen-specific Treg cells as a potential therapy for human diseases. While this role for TGF-beta is well confirmed, several critical questions remain largely unanswered and await further investigation. In this regard, it is imperative to understand the molecular pathways by which TGF-beta signaling initiates and regulates Foxp3 expression. It is also important to elucidate which factors and/or cytokines influence the TGF-beta-mediated conversion of naïve T cells and how to create an immunologically regulatory milieu to facilitate Treg cell generation in vivo. In this short article, we will highlight the key findings and recent progress in the field, discuss the molecular mechanisms underlying the TGF-beta-mediated induction of Foxp3, and attempt to outline the challenges ahead.

  8. Generation of Transplantable Beta Cells for Patient-Specific Cell Therapy

    Directory of Open Access Journals (Sweden)

    Xiaojie Wang

    2012-01-01

    Full Text Available Islet cell transplantation offers a potential cure for type 1 diabetes, but it is challenged by insufficient donor tissue and side effects of current immunosuppressive drugs. Therefore, alternative sources of insulin-producing cells and isletfriendly immunosuppression are required to increase the efficiency and safety of this procedure. Beta cells can be transdifferentiated from precursors or another heterologous (non-beta-cell source. Recent advances in beta cell regeneration from somatic cells such as fibroblasts could circumvent the usage of immunosuppressive drugs. Therefore, generation of patient-specific beta cells provides the potential of an evolutionary treatment for patients with diabetes.

  9. Foodborne cereulide causes beta-cell dysfunction and apoptosis.

    Directory of Open Access Journals (Sweden)

    Roman Vangoitsenhoven

    Full Text Available To study the effects of cereulide, a food toxin often found at low concentrations in take-away meals, on beta-cell survival and function.Cell death was quantified by Hoechst/Propidium Iodide in mouse (MIN6 and rat (INS-1E beta-cell lines, whole mouse islets and control cell lines (HepG2 and COS-1. Beta-cell function was studied by glucose-stimulated insulin secretion (GSIS. Mechanisms of toxicity were evaluated in MIN6 cells by mRNA profiling, electron microscopy and mitochondrial function tests.24 h exposure to 5 ng/ml cereulide rendered almost all MIN6, INS-1E and pancreatic islets apoptotic, whereas cell death did not increase in the control cell lines. In MIN6 cells and murine islets, GSIS capacity was lost following 24 h exposure to 0.5 ng/ml cereulide (P<0.05. Cereulide exposure induced markers of mitochondrial stress including Puma (p53 up-regulated modulator of apoptosis, P<0.05 and general pro-apoptotic signals as Chop (CCAAT/-enhancer-binding protein homologous protein. Mitochondria appeared swollen upon transmission electron microscopy, basal respiration rate was reduced by 52% (P<0.05 and reactive oxygen species increased by more than twofold (P<0.05 following 24 h exposure to 0.25 and 0.50 ng/ml cereulide, respectively.Cereulide causes apoptotic beta-cell death at low concentrations and impairs beta-cell function at even lower concentrations, with mitochondrial dysfunction underlying these defects. Thus, exposure to cereulide even at concentrations too low to cause systemic effects appears deleterious to the beta-cell.

  10. The Role of Oxidative Stress and Hypoxia in Pancreatic Beta-Cell Dysfunction in Diabetes Mellitus.

    Science.gov (United States)

    Gerber, Philipp A; Rutter, Guy A

    2017-04-01

    Metabolic syndrome is a frequent precursor of type 2 diabetes mellitus (T2D), a disease that currently affects ∼8% of the adult population worldwide. Pancreatic beta-cell dysfunction and loss are central to the disease process, although understanding of the underlying molecular mechanisms is still fragmentary. Recent Advances: Oversupply of nutrients, including glucose and fatty acids, and the subsequent overstimulation of beta cells, are believed to be an important contributor to insulin secretory failure in T2D. Hypoxia has also recently been implicated in beta-cell damage. Accumulating evidence points to a role for oxidative stress in both processes. Although the production of reactive oxygen species (ROS) results from enhanced mitochondrial respiration during stimulation with glucose and other fuels, the expression of antioxidant defense genes is unusually low (or disallowed) in beta cells. Not all subjects with metabolic syndrome and hyperglycemia go on to develop full-blown diabetes, implying an important role in disease risk for gene-environment interactions. Possession of common risk alleles at the SLC30A8 locus, encoding the beta-cell granule zinc transporter ZnT8, may affect cytosolic Zn 2+ concentrations and thus susceptibility to hypoxia and oxidative stress. Loss of normal beta-cell function, rather than total mass, is increasingly considered to be the major driver for impaired insulin secretion in diabetes. Better understanding of the role of oxidative changes, its modulation by genes involved in disease risk, and effects on beta-cell identity may facilitate the development of new therapeutic strategies to this disease. Antioxid. Redox Signal. 26, 501-518.

  11. Inflammatory Cytokines Stimulate Bone Morphogenetic Protein-2 Expression and Release from Pancreatic Beta Cells

    DEFF Research Database (Denmark)

    Urizar, Adriana Ibarra; Friberg, Josefine; Christensen, Dan Ploug

    2016-01-01

    The proinflammatory cytokines interleukin-1 beta (IL-1β) and interferon gamma (IFN-γ) play important roles in the progressive loss of beta-cell mass and function during development of both type 1 and type 2 diabetes. We have recently showed that bone morphogenetic protein (BMP)-2 and -4 are expre......The proinflammatory cytokines interleukin-1 beta (IL-1β) and interferon gamma (IFN-γ) play important roles in the progressive loss of beta-cell mass and function during development of both type 1 and type 2 diabetes. We have recently showed that bone morphogenetic protein (BMP)-2 and -4...... 6- and 3-fold in isolated islets of Langerhans from neonatal rat and human. Downstream target genes of the BMP pathway were also increased by cytokine treatment and could be reversed by neutralization of endogenous BMP activity. Nuclear factor kappa B- (NFκB) binding sites were identified in the rat...... BMP-2 promoter, and reporter assays verified the role of NFκB in cytokine-induced BMP-2 expression. Electrophoretic mobility shift assay and chromatin immunoprecipitation assays confirmed NFκB binding to BMP-2 promoter upon IL-1β stimulation in beta cells. In conclusion, we suggest that NFκ...

  12. An assessment of anti-neutrino mass determination via electrostatic measurements of tritium beta-decay

    International Nuclear Information System (INIS)

    Le Bas, P.A.

    1984-01-01

    Data on the mass of the anti-neutrino determined via electrostatic measurements of tritium beta-decay are assessed. Relativistic calculations concerning the finite mass of the electron anti-neutrino and the recoil of the nucleus, are given for the theoretical end-point spectrum of tritium beta-decay. The specifications are given for an electrostatic Spherical Retarding Beta-Spectrometer, and an electrostatic Cylindrical Mirror Analyser, both used in the tritium beta-decay experiment. The electrostatic measurements lead to a value of less than 50 ev (90% C.L.) for the electron anti-neutrino mass. These results are discussed in terms of the resolution of the electrostatic equipment and the Monte Carlo simulations of the data collection. (UK)

  13. Effects of exendin-4 on glucose tolerance, insulin secretion, and beta-cell proliferation depend on treatment dose, treatment duration and meal contents

    Energy Technology Data Exchange (ETDEWEB)

    Arakawa, Masayuki; Ebato, Chie; Mita, Tomoya [Department of Medicine, Metabolism and Endocrinology, Juntendo University School of Medicine, Tokyo (Japan); Hirose, Takahisa [Department of Medicine, Metabolism and Endocrinology, Juntendo University School of Medicine, Tokyo (Japan); Center for Therapeutic Innovations in Diabetes, Juntendo University School of Medicine, Tokyo (Japan); Kawamori, Ryuzo [Department of Medicine, Metabolism and Endocrinology, Juntendo University School of Medicine, Tokyo (Japan); Center for Therapeutic Innovations in Diabetes, Juntendo University School of Medicine, Tokyo (Japan); Center for Beta Cell Biology and Regeneration, Juntendo University School of Medicine, Tokyo (Japan); Sportology Center, Juntendo University School of Medicine, Tokyo (Japan); Fujitani, Yoshio, E-mail: fujitani@juntendo.ac.jp [Department of Medicine, Metabolism and Endocrinology, Juntendo University School of Medicine, Tokyo (Japan); Center for Therapeutic Innovations in Diabetes, Juntendo University School of Medicine, Tokyo (Japan); Watada, Hirotaka, E-mail: hwatada@juntendo.ac.jp [Department of Medicine, Metabolism and Endocrinology, Juntendo University School of Medicine, Tokyo (Japan); Sportology Center, Juntendo University School of Medicine, Tokyo (Japan)

    2009-12-18

    Beta-cell proliferation is regulated by various metabolic demands including peripheral insulin resistance, obesity, and hyperglycemia. In addition to enhancement of glucose-induced insulin secretion, agonists for glucagon-like peptide-1 receptor (GLP-1R) stimulate proliferation and inhibit apoptosis of beta-cells, thereby probably preserve beta-cell mass. To evaluate the beta-cell preserving actions of GLP-1R agonists, we assessed the acute and chronic effects of exendin-4 on beta-cell proliferation, mass and glucose tolerance in C57BL/6J mice under various conditions. Short-term administration of high-dose exendin-4 transiently stimulated beta-cell proliferation. Comparative transcriptomic analysis showed upregulation of IGF-1 receptor and its downstream effectors in islets. Treatment of mice with exendin-4 daily for 4 weeks (long-term administration) and feeding high-fat diet resulted in significant inhibition of weight gain and improvement of glucose tolerance with reduced insulin secretion and beta-cell mass. These findings suggest that long-term GLP-1 treatment results in insulin sensitization of peripheral organs, rather than enhancement of beta-cell proliferation and function, particularly when animals are fed high-fat diet. Thus, the effects of exendin-4 on glucose tolerance, insulin secretion, and beta-cell proliferation largely depend on treatment dose, duration of treatment and meal contents. While GLP-1 enhances proliferation of beta-cells in some diabetic mice models, our results suggest that GLP-1 stimulates beta-cell growth only when expansion of beta-cell mass is required to meet metabolic demands.

  14. Strain-dependent differences in sensitivity of rat beta-cells to interleukin 1 beta in vitro and in vivo

    DEFF Research Database (Denmark)

    Reimers, J I; Andersen, H U; Mauricio, D

    1996-01-01

    The aim of this study was to investigate whether strain-dependent differences in beta-cell sensitivity to interleukin (IL) 1 beta exist in vitro and in vivo and if so, whether these differences correlate to variations in IL-1 beta-induced islet inducible nitric oxide synthase (iNOS) mRNA expression...

  15. Beta-cell lines derived from transgenic mice expressing a hybrid insulin gene-oncogene

    DEFF Research Database (Denmark)

    Efrat, S; Linde, S; Kofod, Hans

    1988-01-01

    Three pancreatic beta-cell lines have been established from insulinomas derived from transgenic mice carrying a hybrid insulin-promoted simian virus 40 tumor antigen gene. The beta tumor cell (beta TC) lines maintain the features of differentiated beta cells for about 50 passages in culture...... by glucose, although with a lower threshold for maximal stimulation than that for normal beta cells. beta TC lines can be repeatedly derived from primary beta-cell tumors that heritably arise in the transgenic mice. Thus, targeted expression of an oncogene with a cell-specific regulatory element can be used...

  16. Novel Transgenic Mice for Inducible Gene Overexpression in Pancreatic Cells Define Glucocorticoid Receptor-Mediated Regulations of Beta Cells

    Science.gov (United States)

    Massouridès, Emmanuelle; Singh-Estivalet, Amrit; Valtat, Bérengère; Dorchene, Delphine; Jaisser, Frédéric; Bréant, Bernadette; Tronche, Francois

    2012-01-01

    Conditional gene deletion in specific cell populations has helped the understanding of pancreas development. Using this approach, we have shown that deleting the glucocorticoid receptor (GR) gene in pancreatic precursor cells leads to a doubled beta-cell mass. Here, we provide genetic tools that permit a temporally and spatially controlled expression of target genes in pancreatic cells using the Tetracycline inducible system. To efficiently target the Tetracycline transactivator (tTA) in specific cell populations, we generated Bacterial Artificial Chromosomes (BAC) transgenic mice expressing the improved Tetracycline transactivator (itTA) either in pancreatic progenitor cells expressing the transcription factor Pdx1 (BAC-Pdx1-itTA), or in beta cells expressing the insulin1 gene (BAC-Ins1-itTA). In the two transgenic models, itTA-mediated activation of reporter genes was efficient and subject to regulation by Doxycycline (Dox). The analysis of a tetracycline-regulated LacZ reporter gene shows that in BAC-Pdx1-itTA mice, itTA is expressed from embryonic (E) day 11.5 in all pancreatic precursor cells. In the adult pancreas, itTA is active in mature beta, delta cells and in few acinar cells. In BAC-Ins1-itTA mice tTA is active from E13.5 and is restricted to beta cells in fetal and adult pancreas. In both lines, tTA activity was suppressed by Dox treatment and re-induced after Dox removal. Using these transgenic lines, we overexpressed the GR in selective pancreatic cell populations and found that overexpression in precursor cells altered adult beta-cell fraction but not glucose tolerance. In contrast, GR overexpression in mature beta cells did not alter beta-cell fraction but impaired glucose tolerance with insufficient insulin secretion. In conclusion, these new itTA mouse models will allow fine-tuning of gene expression to investigate gene function in pancreatic biology and help us understand how glucocorticoid signaling affects on the long-term distinct aspects of

  17. Glucose- and interleukin-1beta-induced beta-cell apoptosis requires Ca2+ influx and extracellular signal-regulated kinase (ERK) 1/2 activation and is prevented by a sulfonylurea receptor 1/inwardly rectifying K+ channel 6.2 (SUR/Kir6.2) selective potassium channel opener in human islets

    DEFF Research Database (Denmark)

    Maedler, Kathrin; Størling, Joachim; Sturis, Jeppe

    2004-01-01

    Increasing evidence indicates that a progressive decrease in the functional beta-cell mass is the hallmark of both type 1 and type 2 diabetes. The underlying causes, beta-cell apoptosis and impaired secretory function, seem to be partly mediated by macrophage production of interleukin (IL)-1beta ...

  18. Pancreatic beta cell protection/regeneration with phytotherapy

    Directory of Open Access Journals (Sweden)

    Azar Hosseini

    2015-03-01

    Full Text Available Although currently available drugs are useful in controlling early onset complications of diabetes, serious late onset complications appear in a large number of patients. Considering the physiopathology of diabetes, preventing beta cell degeneration and stimulating the endogenous regeneration of islets will be essential approaches for the treatment of insulin-dependent diabetes mellitus. The current review focused on phytochemicals, the antidiabetic effect of which has been proved by pancreatic beta cell protection/regeneration. Among the hundreds of plants that have been investigated for diabetes, a small fraction has shown the regenerative property and was described in this paper. Processes of pancreatic beta cell degeneration and regeneration were described. Also, the proposed mechanisms for the protective/regenerative effects of such phytochemicals and their potential side effects were discussed.

  19. Response of beta diversity to pulses of Ordovician-Silurian mass extinction.

    Science.gov (United States)

    Darroch, Simon A F; Wagner, Peter J

    2015-02-01

    Ecologists are increasingly using the fossil record of mass extinction to build predictive models for the ongoing biodiversity crisis. During mass extinctions, major depletions in global (i.e., gamma) diversity may reflect decrease in alpha diversity (i.e., local assemblages support fewer taxa), and/or decrease in beta diversity (such that similar pools of taxa are common to a greater number of local areas). Contrasting the effects of extinction on alpha and beta diversity is therefore central to understanding how global richness becomes depleted over these critical events. Here we investigate the spatial effects of mass extinction by examining changes in alpha, beta, and gamma diversity in brachiopod communities over both pulses of Ordovician-Silurian extinction (-445.2 and -438.8 million years ago), which had dramatically different causal mechanisms. We furthermore reconstruct geographic range sizes for brachiopod genera to test competing models for drivers of beta diversity change. We find that: (1) alpha and beta diversity respond differently to extinction; (2) these responses differ between pulses of extinction; (3) changes in beta diversity associated with extinction are accompanied by changes in geographic range size; and (4) changes in global beta diversity were driven by the extinction of taxa with statistically small and large ranges, rather than range expansion/contraction in taxa that survive into the aftermath. A symptom of ongoing biotic crisis may therefore be the extinction of specific narrow- or wide-ranging taxa, rather than the global proliferation of opportunistic and "disaster" forms. In addition, our results illustrate that changes in beta diversity on these longer timescales may largely be dictated by emplacement and removal of barriers to dispersal. Lastly, this study reinforces the utility of the fossil record in addressing questions surrounding the role of global-scale processes (such as mass extinctions) in sculpting and assembling

  20. The potential role of SOCS-3 in the interleukin-1beta-induced desensitization of insulin signaling in pancreatic beta-cells

    DEFF Research Database (Denmark)

    Emanuelli, Brice; Glondu, Murielle; Filloux, Chantal

    2004-01-01

    insulin-dependent IR autophosphorylation and IRS/PI3K pathway in a way comparable to IL-1beta treatment in RINm5F cells. We propose that IL-1beta decreases insulin action in beta-cells through the induction of SOCS-3 expression, and that this effect potentially alters insulin-induced beta-cell survival.......Defects in insulin secretion, resulting from loss of function or destruction of pancreatic beta-cells, trigger diabetes. Interleukin (IL)-1beta is a proinflammatory cytokine that is involved in type 1 and type 2 diabetes development and impairs beta-cell survival and function. Because effective...... insulin signaling is required for the optimal beta-cell function, we assessed the effect of IL-1beta on the insulin pathway in a rat pancreatic beta-cell line. We show that IL-1beta decreases insulin-induced tyrosine phosphorylation of the insulin receptor (IR) and insulin receptor substrate (IRS...

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

    DEFF Research Database (Denmark)

    Pedersen, Morten Gram

    2006-01-01

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

  2. Molecular mass distribution and epitopes of the beta lactoglobulin submitted to hydrolysis pre-transglutaminase treatment

    Energy Technology Data Exchange (ETDEWEB)

    Villas-Boas, M.B.; Zollner, R.L.; Netto, F.M. [Universidade Estadual de Campinas (UNICAMP), SP (Brazil); Paes Leme, A.F. [Laboratorio Nacional de Luz Sincrotron (LNLS), Campinas, SP (Brazil); Benede, S.; Molina, E. [Universidad Autonoma de Madrid (Spain)

    2012-07-01

    Full text: The {beta}-Lactoglobulin ({beta}-Lg) is a whey protein with important nutritional proper ties but very resistant to pepsin digestion and consequently highly antigenic. This protein can be modified by transglutaminase (TG) although it is required a pretreatment to increase their susceptibility to the TG action. In the present study the hydrolysis pre-TG treatment was used to improve the TG accessibility on {beta}-Lg and the MM distribution and antigenic fragments were evaluated. For pre-TG treatment, the {beta}-Lg (Davisco Inc.) was hydrolyzed with bromelain (3% of {beta}-Lg w/w in distilled water; 25 U enzyme g{sup 1} of substrate, pH 7.5, 240 min) and then polymerized by TG (7% hydrolysate, 10U TG g{sup 1} protein, 50 C/180 min). The samples were evaluated by SDS-PAGE/tricine and by RP-nanoUPLC (nanoAcquity UPLC, Waters) coupled with nano-electrospray tandem mass spectrometry on a Q-Tof Ultima API mass spectrometer (MicroMass/Waters) at LNBio. The products were also submitted to pepsin digestion and the peptide identification was performed by RP-HPLC-tandem mass spectrometry (RP-HPLC-MS/MS, Brucker) with support from CIAL. The {beta}-Lg hydrolysed by bromelain and polymerized by TG had a broad MM distribution. The intact mass analysis indicated that the non modified {beta}Lg -A showed 18.362 Da and the non modified {beta}Lg -B 18.274 Da, which is in agreement with the theoretical corresponding masses. The use of bromelain pre-TG treatment resulted in polymers with MM from 61.052 to 67.654 Da, although some non modified protein was still present. In addition, the non modified {beta}-Lg showed fragments that present high antigenicity (such as Leu{sub 95} - Leu{sub 104}, Asp{sub 95} - Phe{sub 105}, Tyr{sub 42} - Leu{sub 54}, lle{sub 29} - Val{sub 41}), previously identified as IgE-binding epitopes. After hydrolysis following by TG treatment the fragment Tyr{sub 42} - Leu{sub 54} was still present, however the other fragments that were observed in the non

  3. Microculture system for studying monolayers of functional beta-cells.

    Science.gov (United States)

    Dobersen, M J; Scharff, J E; Notkins, A L

    1980-04-01

    A method is described for growing monolayers of newborn rat beta-cells in microculture trays. After disruption of the pancreas with collagenase, islets were isolated by Ficoll density gradient centrifugation, trypsinized to obtain individual cells, and plated in 96-well tissue culture trays. The cells were incubated for the first 3 days in growth medium containing 0.1 mM 3-isobutyl-1-methylxanthine to promote monolayer formation. The cultures could be maintained in a functional state, as defined by their responsiveness to known modulators of insulin secretion, for at least 2 weeks. As few as 1 X 10(3) islet cells/well gave results that were reproducible within +/- 10%. It is suggested that the microculture system for islet cells might prove to be a rapid and reproducible screening technique for studying drugs, viruses, or other agents that affect beta-cell function.

  4. Double beta decay and majorana neutrinos. Right-handed currents or nonzero masses

    International Nuclear Information System (INIS)

    Rosen, S.P.; Perlmutter, A.

    1981-01-01

    This chapter describes some new developments concerning the mechanism for lepton number nonconservation in no-neutrino double beta decay. Explains that lepton number nonconservation in no-neutrino double beta decay comes about either because both left- and right-handed components of a Majorano neutrino are coupled to the electron in the weak leptonic current, or because the neutrino has nonzero mass. Shows that while nuclear ground-state to ground-state transitions arise from right-handed currents and from neutrino mass terms, transitions to low-lying excited states with J /SUP P/ =2 + can arise only from right-handed currents. Emphasizes that the possibilities of detecting small admixtures of right-handed currents, and of setting limits on neutrino masses that are either very small or very large, make double beta decay a most rewarding phenomenon to study

  5. beta-Catenin signaling is required for TGF-beta(1)-induced extracellular matrix production by airway smooth muscle cells

    NARCIS (Netherlands)

    Baarsma, Hoeke A.; Menzen, Mark H.; Halayko, Andrew J.; Meurs, Herman; Kerstjens, Huib A. M.; Gosens, Reinoud

    2011-01-01

    Baarsma HA, Menzen MH, Halayko AJ, Meurs H, Kerstjens HA, Gosens R. beta-Catenin signaling is required for TGF-beta(1)-induced extracellular matrix production by airway smooth muscle cells. Am J Physiol Lung Cell Mol Physiol 301: L956-L965, 2011. First published September 9, 2011; doi:

  6. Limits on neutrino masses from tritium beta decay

    CERN Document Server

    Bonn, J; Bornschein, L; Flatt, B; Kraus, C V; Otten, E W; Schall, J P; Thuemmler, T; Weinheimer, C

    2002-01-01

    The presently lowest limit for the mass of the electron neutrino is m nu < 2.2 eV (95 % C.L.) derived from measurements at Mainz up to 1999. The data taken in 2000 are not fully analyzed yet but limits of possible distortions as reported by the Troitsk group can be given. The next generation neutrino mass experiment KATRIN is briefly discussed.

  7. The potential role of SOCS-3 in the interleukin-1beta-induced desensitization of insulin signaling in pancreatic beta-cells

    DEFF Research Database (Denmark)

    Emanuelli, Brice; Glondu, Murielle; Filloux, Chantal

    2004-01-01

    insulin-dependent IR autophosphorylation and IRS/PI3K pathway in a way comparable to IL-1beta treatment in RINm5F cells. We propose that IL-1beta decreases insulin action in beta-cells through the induction of SOCS-3 expression, and that this effect potentially alters insulin-induced beta-cell survival....

  8. Dual role of proapoptotic BAD in insulin secretion and beta cell survival.

    Science.gov (United States)

    Danial, Nika N; Walensky, Loren D; Zhang, Chen-Yu; Choi, Cheol Soo; Fisher, Jill K; Molina, Anthony J A; Datta, Sandeep Robert; Pitter, Kenneth L; Bird, Gregory H; Wikstrom, Jakob D; Deeney, Jude T; Robertson, Kirsten; Morash, Joel; Kulkarni, Ameya; Neschen, Susanne; Kim, Sheene; Greenberg, Michael E; Corkey, Barbara E; Shirihai, Orian S; Shulman, Gerald I; Lowell, Bradford B; Korsmeyer, Stanley J

    2008-02-01

    The proapoptotic BCL-2 family member BAD resides in a glucokinase-containing complex that regulates glucose-driven mitochondrial respiration. Here, we present genetic evidence of a physiologic role for BAD in glucose-stimulated insulin secretion by beta cells. This novel function of BAD is specifically dependent upon the phosphorylation of its BH3 sequence, previously defined as an essential death domain. We highlight the pharmacologic relevance of phosphorylated BAD BH3 by using cell-permeable, hydrocarbon-stapled BAD BH3 helices that target glucokinase, restore glucose-driven mitochondrial respiration and correct the insulin secretory response in Bad-deficient islets. Our studies uncover an alternative target and function for the BAD BH3 domain and emphasize the therapeutic potential of phosphorylated BAD BH3 mimetics in selectively restoring beta cell function. Furthermore, we show that BAD regulates the physiologic adaptation of beta cell mass during high-fat feeding. Our findings provide genetic proof of the bifunctional activities of BAD in both beta cell survival and insulin secretion.

  9. Workshop on programming beta cell development, impairment and regeneration

    DEFF Research Database (Denmark)

    Heller, Scott; Nielsen, Jens Høiriis

    2012-01-01

    (2003), El Perello, Spain (2006) and Peebles, Scotland (2009). The meeting drew 190 attendees from 12 different countries. There were 37 main oral presentations, and 68 posters covered virtually all aspects of the pancreas and provided a dynamic snapshot of the most interesting areas of current...... investigation. In addition, six parallel workshops on stem cells, epigenetics, autoimmunity, β-cell imaging, β-cell identity, omics in β-cell research and a panel discussion on "to be or not to be a beta cell" were held. Here, we will review some of the newest highlights and still unanswered questions...

  10. Hypoglycemic and beta cell protective effects of andrographolide analogue for diabetes treatment

    Directory of Open Access Journals (Sweden)

    Larrick James W

    2009-07-01

    Full Text Available Abstract Background While all anti-diabetic agents can decrease blood glucose level directly or indirectly, few are able to protect and preserve both pancreatic beta cell mass and their insulin-secreting functions. Thus, there is an urgent need to find an agent or combination of agents that can lower blood glucose and preserve pancreatic beta cells at the same time. Herein, we report a dual-functional andrographolide-lipoic acid conjugate (AL-1. The anti-diabetic and beta cell protective activities of this novel andrographolide-lipoic acid conjugate were investigated. Methods In alloxan-treated mice (a model of type 1 diabetes, drugs were administered orally once daily for 6 days post-alloxan treatment. Fasting blood glucose and serum insulin were determined. Pathologic and immunohistochemical analysis of pancreatic islets were performed. Translocation of glucose transporter subtype 4 in soleus muscle was detected by western blot. In RIN-m cells in vitro, the effect of AL-1 on H2O2-induced damage and reactive oxidative species production stimulated by high glucose and glibenclamide were measured. Inhibition of nuclear factor kappa B (NF-κB activation induced by IL-1β and IFN-γ was investigated. Results In alloxan-induced diabetic mouse model, AL-1 lowered blood glucose, increased insulin and prevented loss of beta cells and their dysfunction, stimulated glucose transport protein subtype 4 (GLUT4 membrane translocation in soleus muscles. Pretreatment of RIN-m cells with AL-1 prevented H2O2-induced cellular damage, quenched glucose and glibenclamide-stimulated reactive oxidative species production, and inhibited cytokine-stimulated NF-κB activation. Conclusion We have demonstrated that AL-1 had both hypoglycemic and beta cell protective effects which translated into antioxidant and NF-κB inhibitory activity. AL-1 is a potential new anti-diabetic agent.

  11. Pdx1 restores beta cell function in Irs2 knockout mice.

    Science.gov (United States)

    Kushner, Jake A; Ye, Jing; Schubert, Markus; Burks, Deborah J; Dow, Matthew A; Flint, Carrie L; Dutta, Sanjoy; Wright, Christopher V E; Montminy, Marc R; White, Morris F

    2002-05-01

    The homeodomain transcription factor Pdx1 is required for pancreas development, including the differentiation and function of beta cells. Mutations in Pdx1 or upstream hepatocyte nuclear factors cause autosomal forms of early-onset diabetes (maturity-onset diabetes of the young [MODY]). In mice, the Irs2 branch of the insulin/Igf signaling system mediates peripheral insulin action and pancreatic beta cell growth and function. To investigate whether beta cell failure in Irs2(-/-) mice might be related to dysfunction of MODY-related transcription factors, we measured the expression of Pdx1 in islets from young Irs2(-/-) mice. Before the onset of diabetes, Pdx1 was reduced in islets from Irs2(-/-) mice, whereas it was expressed normally in islets from wild-type or Irs1(-/-) mice, which do not develop diabetes. Whereas male Irs2(-/-)Pdx1(+/+) mice developed diabetes between 8 and 10 weeks of age, haploinsufficiency for Pdx1 caused diabetes in newborn Irs2(-/-) mice. By contrast, transgenic expression of Pdx1 restored beta cell mass and function in Irs2(-/-) mice and promoted glucose tolerance throughout life, as these mice survived for at least 20 months without diabetes. Our results suggest that dysregulation of Pdx1 might represent a common link between ordinary type 2 diabetes and MODY.

  12. TGF-betas synthesized by RPE cells have autocrine activity on mesenchymal transformation and cell proliferation.

    Science.gov (United States)

    Lee, S C; Kim, S H; Koh, H J; Kwon, O W

    2001-06-01

    The present study investigated the effects of transforming growth factor (TGF)-beta on retinal pigment epithelial (RPE) transformation in a simplified model and also whether or not TGF-beta exhibits similar proliferation effects on transformed RPE cells that it has on primary RPE cells. Furthermore, we examined the cell proliferation effects of RPE-conditioned medium (CM). A vertical wound measuring 2 mm in diameter was made on primary RPE monolayers. The expression of alpha-smooth muscle actin (SMA) by the cells located at the wound edges was observed using a confocal microscope under immunofluorescent staining. Cell proliferation was measured by incorporating 3H-thymidine into DNA. The presence of alpha-SMA was observed in the cells within the wound after treatment with TGF-beta2, while negative expression was observed in control cells. TGF-betas inhibited the proliferation of the primary cultures of RPE cells in a dose-dependent manner, but the spindle-shaped late-passaged RPE cells were not inhibited by these growth factors. The medium conditioned by RPE cells stimulated the proliferation of subconjunctival fibroblasts and inhibited the proliferation of primary RPE cells, in a manner similar to TGF-beta. These findings demonstrate that TGF-beta-stimulated RPE cells may evoke proliferative vitreoretinopathy through mesenchymal transformation and cell proliferation.

  13. Neutrino mass bounds from neutrinoless double beta-decays and ...

    Indian Academy of Sciences (India)

    2016-01-21

    Jan 21, 2016 ... where νi is the field of neutrino with mass mi and U is the unitary mixing matrix. Neglec- ting the recoil of ... (10), for normal and inverted hierarchy respectively, in terms of mixing angles and 2 s = m2 ..... ical evolution of the sound speed of neutrinos cs = δPν/δρν with the wavenumber k = 2.3 × 10−3 Mpc−1, ...

  14. Transforming growth factor-beta1 (TGF-beta1) and acetylcholine (ACh) alter nitric oxide (NO) and interleukin-1beta (IL-1beta) secretion in human colon adenocarcinoma cells.

    Science.gov (United States)

    Paduch, Roman; Kandefer-Szerszeń, Martyna

    2009-10-01

    Colon adenocarcinoma is one of the most common fatal malignancies in Western countries. Progression of this cancer is dependent on tumor microenvironmental signaling molecules such as transforming growth factor-beta (TGF-beta) or acetylcholine (ACh). The present study was conducted to assess the influence of recombinant human transforming growth factor (rhTGF)-beta1 or ACh on nitric oxide (NO) and interleukin-1beta (IL-1beta) secretion by three human colon adenocarcinoma cell lines: HT29, LS180, and SW948, derived from different grade tumors (Duke's stage). The cells were cultured in 2D and 3D (spheroids) conditions. Colon carcinoma cells exhibited different sensitivities to rhTGF-beta1 or ACh dependent on the tumor grade and the culture model. ACh exhibited significant inhibitory effects towards NO, endothelial nitric oxide synthase (eNOS), and IL-1beta secretion especially by tumor cells derived form Duke's C stage of colon carcinoma. rhTGF-beta1 also decreased NO, IL-1beta, and eNOS expression, but its effect was lower than that observed after the administration of ACh. The inhibition of NO and IL-1beta production was more striking in 3D tumor spheroids than in 2D culture monolayers. Taken together, the TGF-beta1-ACh axis may regulate colon carcinoma progression and metastasis by altering NO secretion and influence inflammatory responses by modulating IL-1beta production.

  15. KATRIN :a New Beta-Spectroscopic Experiment to Determine the Neutrino Mass

    Czech Academy of Sciences Publication Activity Database

    Dragoun, Otokar

    2007-01-01

    Roč. 958, - (2007), s. 193-196. ISBN 978-0-7354-0472-4. ISSN N R&D Projects: GA MŠk LC07050 Institutional research plan: CEZ:AV0Z10480505 Keywords : neutrino mass * beta ray spectroscopy Subject RIV: BE - Theoretical Physics

  16. File list: DNS.Pan.20.AllAg.Pancreatic_beta_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available DNS.Pan.20.AllAg.Pancreatic_beta_cells mm9 DNase-seq Pancreas Pancreatic beta cells... http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/DNS.Pan.20.AllAg.Pancreatic_beta_cells.bed ...

  17. File list: His.Pan.50.AllAg.Pancreatic_beta_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.Pan.50.AllAg.Pancreatic_beta_cells mm9 Histone Pancreas Pancreatic beta cells S...RX1035141,SRX1035146,SRX1035144,SRX1035145,SRX1035140 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.Pan.50.AllAg.Pancreatic_beta_cells.bed ...

  18. File list: Pol.Pan.10.AllAg.Pancreatic_beta_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Pol.Pan.10.AllAg.Pancreatic_beta_cells mm9 RNA polymerase Pancreas Pancreatic beta ...cells http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Pol.Pan.10.AllAg.Pancreatic_beta_cells.bed ...

  19. File list: Oth.Pan.05.AllAg.Pancreatic_beta_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Pan.05.AllAg.Pancreatic_beta_cells mm9 TFs and others Pancreas Pancreatic beta ...cells SRX445035,SRX445033,SRX445034 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.Pan.05.AllAg.Pancreatic_beta_cells.bed ...

  20. File list: His.Pan.10.AllAg.Pancreatic_beta_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.Pan.10.AllAg.Pancreatic_beta_cells mm9 Histone Pancreas Pancreatic beta cells S...RX1035146,SRX1035141,SRX1035144,SRX1035140,SRX1035145 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.Pan.10.AllAg.Pancreatic_beta_cells.bed ...

  1. Targeting of beta 1 integrins impairs DNA repair for radiosensitization of head and neck cancer cells

    NARCIS (Netherlands)

    Dickreuter, E.; Eke, I.; Krause, M.; Borgmann, K.; van Vugt, M. A.; Cordes, N.

    2016-01-01

    beta 1 Integrin-mediated cell-extracellular matrix interactions allow cancer cell survival and confer therapy resistance. It was shown that inhibition of beta 1 integrins sensitizes cells to radiotherapy. Here, we examined the impact of beta 1 integrin targeting on the repair of radiation-induced

  2. Hypothesis: Musculin is a hormone secreted by skeletal muscle, the body's largest endocrine organ. Evidence for actions on the endocrine pancreas to restrain the beta-cell mass and to inhibit insulin secretion and on the hypothalamus to co-ordinate the neuroendocrine and appetite responses to exercise.

    Science.gov (United States)

    Engler, Dennis

    2007-01-01

    Recent studies indicate that skeletal muscle may act as an endocrine organ by secreting interleukin-6 (IL-6) into the systemic circulation. From an analysis of the actions of IL-6 and of additional literature, we postulate that skeletal muscle also secretes an unidentified hormone, which we have named Musculin (Latin: musculus = muscle), which acts on the pancreatic beta-cell to restrain the size of the (beta-cell mass and to tonically inhibit insulin secretion and biosynthesis. It is suggested that the amount of Musculin secreted is determined by, and is positively correlated with, the prevailing insulin sensitivity of skeletal muscle, thereby accounting for the hyperinsulinemia that occurs in insulin resistant disorders such as type 2 diabetes mellitus, obesity, and the polycystic ovary syndrome. In addition, it is postulated that Musculin acts on the hypothalamus (arcuate nucleus, dorsomedial hypothalamic nucleus) to co-ordinate the neuroendocrine and appetite responses to exercise. However, the possibilities that Musculin may act on additional central nervous system sites and that an additional hormone(s) may be responsible for these actions are not excluded. It is suggested that a search be made for Musculin, since analogues of such a substance may be of therapeutic benefit in the treatment of the current global diabetes and obesity epidemic.

  3. TGF-{beta}-stimulated aberrant expression of class III {beta}-tubulin via the ERK signaling pathway in cultured retinal pigment epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Eun Jee [Department of Ophthalmology, National Health Insurance Corporation Ilsan Hospital, Gyeonggi-do (Korea, Republic of); Chun, Ji Na; Jung, Sun-Ah [Konyang University Myunggok Medical Research Institute, Kim' s Eye Hospital, Konyang University College of Medicine, Seoul (Korea, Republic of); Cho, Jin Won [Department of Biology, Yonsei University, 134 Shinchon-dong, Seodaemun-gu, Seoul 120-749 (Korea, Republic of); Lee, Joon H., E-mail: joonhlee@konyang.ac.kr [Konyang University Myunggok Medical Research Institute, Kim' s Eye Hospital, Konyang University College of Medicine, Seoul (Korea, Republic of)

    2011-11-18

    Highlights: Black-Right-Pointing-Pointer TGF-{beta} induces aberrant expression of {beta}III in RPE cells via the ERK pathway. Black-Right-Pointing-Pointer TGF-{beta} increases O-GlcNAc modification of {beta}III in RPE cells. Black-Right-Pointing-Pointer Mature RPE cells have the capacity to express a neuron-associated gene by TGF-{beta}. -- Abstract: The class III {beta}-tubulin isotype ({beta}{sub III}) is expressed exclusively by neurons within the normal human retina and is not present in normal retinal pigment epithelial (RPE) cells in situ or in the early phase of primary cultures. However, aberrant expression of class III {beta}-tubulin has been observed in passaged RPE cells and RPE cells with dedifferentiated morphology in pathologic epiretinal membranes from idiopathic macular pucker, proliferative vitreoretinopathy (PVR) and proliferative diabetic retinopathy (PDR). Transforming growth factor-{beta} (TGF-{beta}) has been implicated in dedifferentiation of RPE cells and has a critical role in the development of proliferative vitreoretinal diseases. Here, we investigated the potential effects of TGF-{beta} on the aberrant expression of class III {beta}-tubulin and the intracellular signaling pathway mediating these changes. TGF-{beta}-induced aberrant expression and O-linked-{beta}-N-acetylglucosamine (O-GlcNac) modification of class III {beta}-tubulin in cultured RPE cells as determined using Western blotting, RT-PCR and immunocytochemistry. TGF-{beta} also stimulated phosphorylation of ERK. TGF-{beta}-induced aberrant expression of class III {beta}-tubulin was significantly reduced by pretreatment with U0126, an inhibitor of ERK phosphorylation. Our findings indicate that TGF-{beta} stimulated aberrant expression of class III {beta}-tubulin via activation of the ERK signaling pathway. These data demonstrate that mature RPE cells have the capacity to express a neuron-associated gene in response to TGF-{beta} stimulation and provide useful information

  4. SIRT6-mediated transcriptional suppression of Txnip is critical for pancreatic beta cell function and survival in mice.

    Science.gov (United States)

    Qin, Kunhua; Zhang, Ning; Zhang, Zhao; Nipper, Michael; Zhu, Zhenxin; Leighton, Jake; Xu, Kexin; Musi, Nicolas; Wang, Pei

    2018-04-01

    Better understanding of how genetic and epigenetic components control beta cell differentiation and function is key to the discovery of novel therapeutic approaches to prevent beta cell dysfunction and failure in the progression of type 2 diabetes. Our goal was to elucidate the role of histone deacetylase sirtuin 6 (SIRT6) in beta cell development and homeostasis. Sirt6 endocrine progenitor cell conditional knockout and beta cell-specific knockout mice were generated using the Cre-loxP system. Mice were assayed for islet morphology, glucose tolerance, glucose-stimulated insulin secretion and susceptibility to streptozotocin. Transcriptional regulatory functions of SIRT6 in primary islets were evaluated by RNA-Seq analysis. Reverse transcription-quantitative (RT-q)PCR and immunoblot were used to verify and investigate the gene expression changes. Chromatin occupancies of SIRT6, H3K9Ac, H3K56Ac and active RNA polymerase II were evaluated by chromatin immunoprecipitation. Deletion of Sirt6 in pancreatic endocrine progenitor cells did not affect endocrine morphology, beta cell mass or insulin production but did result in glucose intolerance and defective glucose-stimulated insulin secretion in mice. Conditional deletion of Sirt6 in adult beta cells reproduced the insulin secretion defect. Loss of Sirt6 resulted in aberrant upregulation of thioredoxin-interacting protein (TXNIP) in beta cells. SIRT6 deficiency led to increased acetylation of histone H3 lysine residue at 9 (H3K9Ac), acetylation of histone H3 lysine residue at 56 (H3K56Ac) and active RNA polymerase II at the promoter region of Txnip. SIRT6-deficient beta cells exhibited a time-dependent increase in H3K9Ac, H3K56Ac and TXNIP levels. Finally, beta cell-specific SIRT6-deficient mice showed increased sensitivity to streptozotocin. Our results reveal that SIRT6 suppresses Txnip expression in beta cells via deacetylation of histone H3 and plays a critical role in maintaining beta cell function and viability

  5. Beta Decay in the Field of an Electromagnetic Wave and Experiments on Measuring the Neutrino Mass

    International Nuclear Information System (INIS)

    Dorofeev, O.F.; Lobanov, A.E.

    2005-01-01

    Investigations of the effect of an electromagnetic wave field on the beta-decay process are used to analyze the tritium-decay experimental data on the neutrino mass. It is shown that the electromagnetic wave can distort the beta spectrum, shifting the end point to the higher energy region. This phenomenon is purely classical and it is associated with the electron acceleration in the radiation field. Since strong magnetic fields exist in setups for precise measurement of the neutrino mass, the indicated field can appear owing to the synchrotron radiation mechanism. The phenomenon under consideration can explain the experimentally observed anomalies in the spectrum of the decay electrons; in particular, the effect of the 'negative square of the neutrino mass'

  6. Conditional islet hypovascularisation does not preclude beta cell expansion during pregnancy in mice.

    Science.gov (United States)

    Staels, Willem; Heremans, Yves; Leuckx, Gunter; Van Gassen, Naomi; Salinno, Ciro; De Groef, Sofie; Cools, Martine; Keshet, Eli; Dor, Yuval; Heimberg, Harry; De Leu, Nico

    2017-06-01

    Endothelial-endocrine cell interactions and vascular endothelial growth factor (VEGF)-A signalling are deemed essential for maternal islet vascularisation, glucose control and beta cell expansion during mouse pregnancy. The aim of this study was to assess whether pregnancy-associated beta cell expansion was affected under conditions of islet hypovascularisation. Soluble fms-like tyrosine kinase 1 (sFLT1), a VEGF-A decoy receptor, was conditionally overexpressed in maternal mouse beta cells from 1.5 to 14.5 days post coitum. Islet vascularisation, glycaemic control, beta cell proliferation, individual beta cell size and total beta cell volume were assessed in both pregnant mice and non-pregnant littermates. Conditional overexpression of sFLT1 in beta cells resulted in islet hypovascularisation and glucose intolerance in both pregnant and non-pregnant mice. In contrast to non-pregnant littermates, glucose intolerance in pregnant mice was transient. sFLT1 overexpression did not affect pregnancy-associated changes in beta cell proliferation, individual beta cell size or total beta cell volume. Reduced intra-islet VEGF-A signalling results in maternal islet hypovascularisation and impaired glycaemic control but does not preclude beta cell expansion during mouse pregnancy.

  7. Pancreatic beta cell protection/regeneration with phytotherapy

    OpenAIRE

    Hosseini, Azar; Shafiee-Nick, Reza; Ghorbani, Ahmad

    2015-01-01

    Although currently available drugs are useful in controlling early onset complications of diabetes, serious late onset complications appear in a large number of patients. Considering the physiopathology of diabetes, preventing beta cell degeneration and stimulating the endogenous regeneration of islets will be essential approaches for the treatment of insulin-dependent diabetes mellitus. The current review focused on phytochemicals, the antidiabetic effect of which has been proved by pancreat...

  8. T cell precursor migration towards beta 2-microglobulin is involved in thymus colonization of chicken embryos

    DEFF Research Database (Denmark)

    Dunon, D; Kaufman, J; Salomonsen, J

    1990-01-01

    beta 2-microglobulin (beta 2m) attracts hemopoietic precursors from chicken bone marrow cells in vitro. The cell population responding to beta 2m increases during the second period of thymus colonization, which takes place at days 12-14 of incubation. The precursors from 13.5 day old embryos were...... isolated after migration towards beta 2m in vitro and shown to be able to colonize a 13 day old thymus in ovo, where they subsequently acquire thymocyte markers. In contrast these beta 2m responsive precursors did not colonize embryonic bursa, i.e. differentiate into B lymphocytes. During chicken...... embryogenesis, peaks of beta 2m transcripts and of free beta 2m synthesis can only be detected in the thymus. The peak of free beta 2m synthesis in the thymus and the increase of beta 2m responding bone marrow cells both occur concomitantly with the second wave of thymus colonization in chicken embryo, facts...

  9. Protective role of gamma/delta T cells and alpha/beta T cells in tuberculosis.

    Science.gov (United States)

    Ladel, C H; Blum, C; Dreher, A; Reifenberg, K; Kaufmann, S H

    1995-10-01

    Tuberculosis is a chronic infectious disease which causes major health problems globally. Although acquired resistance crucially depends on alpha/beta lymphocytes, circumstantial evidence suggests that, in addition, gamma/delta T lymphocytes contribute to protection against tuberculosis. We have studied Mycobacterium tuberculosis infection in TcR-delta-/- or TcR-beta-/- gene deletion mutants which completely lack gamma/delta T cells or alpha/beta T cells, respectively. Low inocula of M. tuberculosis led to death of TcR-beta-/- mice and transient disease exacerbation in TcR-delta-/- mutants. Infection with higher inocula caused rapid death of TcR-delta-/- mice. The development of and bacterial containment in granulomatous lesions was markedly impaired in TcR-beta-/-, and less severely affected in TcR-delta-/- mutants. Mycobacteria-induced IFN-gamma production by spleen cells in vitro was almost abolished in TcR-beta-/- and virtually unaffected in TcR-delta-/- mice. Our data confirm the crucial role of alpha/beta T cells in protection against established tuberculosis and formally prove a protective role of gamma/delta T cells in early tuberculosis.

  10. A neural mass model of basal ganglia nuclei simulates pathological beta rhythm in Parkinson's disease

    Science.gov (United States)

    Liu, Fei; Wang, Jiang; Liu, Chen; Li, Huiyan; Deng, Bin; Fietkiewicz, Chris; Loparo, Kenneth A.

    2016-12-01

    An increase in beta oscillations within the basal ganglia nuclei has been shown to be associated with movement disorder, such as Parkinson's disease. The motor cortex and an excitatory-inhibitory neuronal network composed of the subthalamic nucleus (STN) and the external globus pallidus (GPe) are thought to play an important role in the generation of these oscillations. In this paper, we propose a neuron mass model of the basal ganglia on the population level that reproduces the Parkinsonian oscillations in a reciprocal excitatory-inhibitory network. Moreover, it is shown that the generation and frequency of these pathological beta oscillations are varied by the coupling strength and the intrinsic characteristics of the basal ganglia. Simulation results reveal that increase of the coupling strength induces the generation of the beta oscillation, as well as enhances the oscillation frequency. However, for the intrinsic properties of each nucleus in the excitatory-inhibitory network, the STN primarily influences the generation of the beta oscillation while the GPe mainly determines its frequency. Interestingly, describing function analysis applied on this model theoretically explains the mechanism of pathological beta oscillations.

  11. File list: ALL.Pan.50.AllAg.Pancreatic_beta_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.Pan.50.AllAg.Pancreatic_beta_cells mm9 All antigens Pancreas Pancreatic beta ce...6,SRX1035143,SRX1035140,SRX1035142 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/ALL.Pan.50.AllAg.Pancreatic_beta_cells.bed ...

  12. Beta-Adrenergic Receptor Expression in Muscle Cells

    Science.gov (United States)

    Young, Ronald B.; Bridge, K.; Vaughn, J. R.

    1999-01-01

    beta-adrenergic receptor (bAR) agonists presumably exert their physiological action on skeletal muscle cells through the bAR. Since the signal generated by the bAR is cyclic AMP (cAMP), experiments were initiated in primary chicken muscle cell cultures to determine if artificial elevation of intracellular cAMP by treatment with forskolin would alter the population of bAR expressed on the surface of muscle cells. Chicken skeletal muscle cells after 7 days in culture were employed for the experiments because muscle cells have attained a steady state with respect to muscle protein metabolism at this stage. Cells were treated with 0-10 uM forskolin for a total of three days. At the end of the 1, 2, and 3 day treatment intervals, the concentration of cAMP and the bAR population were measured. Receptor population was measured in intact muscle cell cultures as the difference between total binding of [H-3]CGP-12177 and non-specific binding of [H-3]CGP-12177 in the presence of 1 uM propranolol. Intracellular cAMP concentration was measured by radioimmunoassay. The concentration of cAMP in forskolin-treated cells increased up to 10-fold in a dose dependent manner. Increasing concentrations of forskolin also led to an increase in (beta)AR population, with a maximum increase of approximately 50% at 10 uM. This increase in (beta)AR population was apparent after only 1 day of treatment, and the pattern of increase was maintained for all 3 days of the treatment period. Thus, increasing the intracellular concentration of cAMP leads to up-regulation of (beta)AR population. Clenbuterol and isoproterenol gave similar effects on bAR population. The effect of forskolin on the quantity and apparent synthesis rate of the heavy chain of myosin (mhc) were also investigated. A maximum increase of 50% in the quantity of mhc was observed at 0.2 UM forskolin, but higher concentrations of forskolin reduced the quantity of mhc back to control levels.

  13. Differentiation of three pairs of Boc-beta,gamma- and gamma,beta-hybrid peptides by electrospray ionization tandem mass spectrometry.

    Science.gov (United States)

    Ramesh, V; Srinivas, R; Sharma, G V M; Jayaprakash, P; Kunwar, A C

    2008-09-01

    A new series of Boc-N-beta(3), gamma(4)-/gamma(4), beta(3)-isomeric hybrid peptides (containing repeats of beta(3)-Caa and gamma(4)-Caa's, Caa = C-linked carbo beta(3)-/gamma(4)-amino acids derived from D-xylose) have been differentiated by both positive and negative ion electrospray ionization (ESI) ion-trap and high resolution quadrupole time-of-flight/tandem mass spectrometry (Q-TOF MS/MS). MS(n) of protonated isomeric peptides and [M+H-Boc+H](+) produce characteristic fragmentation involving the peptide backbone, the Boc-group, and the side chain. The positional isomers are differentiated from one another by the presence of y(n)(+), b(n)(+), and other fragment ions of different m/z values. It is observed that the peptides with beta-Caa at the N-terminus produce extensive fragmentation, whereas gamma-Caa gave rise to much less fragmentation. Peptides with gamma-Caa at the N-terminus lose NH(3), whereas this process is absent for the carbopeptides with beta-Caa at the N-terminus. Two pairs of dipeptide diastereomers are clearly differentiated by the collision-induced dissociation (CID) of their protonated molecules. The loss of 2-methylprop-1-ene is more pronounced for Boc-NH-(R)-beta-Caa-(R)-gamma-Caa-OCH(3) (6) and Boc-NH-(R)-gamma-Caa-(R)-beta-Caa-OCH(3) (12), whereas it is insignificant or totally absent for its protonated diastereomeric pair Boc-NH-(S)-beta-Caa-(S)-gamma-Caa-OCH(3) (1) and Boc-NH-(S)-gamma-Caa-(S)-beta-Caa-OCH(3) (7). Further, ESI negative ion tandem mass spectrometry has also been found to be useful for differentiating these isomeric peptide acids.

  14. A subset of human pancreatic beta cells express functional CD14 receptors: a signaling pathway fot beta cell-related glycolipids, sulfatide and beta-galactosylceramide

    Czech Academy of Sciences Publication Activity Database

    Osterbye, T.; Funda, David P.; Fundová, Petra; Mansson, J.-E.; Tlaskalová-Hogenová, Helena; Buschard, K.

    2010-01-01

    Roč. 26, č. 8 (2010), s. 656-667 E-ISSN 1520-7560 R&D Projects: GA ČR GA303/06/1329; GA ČR GA310/07/0414; GA ČR GA310/09/1640 Institutional research plan: CEZ:AV0Z50200510 Keywords : human beta-cell * cd14 * innate immunity Subject RIV: EE - Microbiology, Virology

  15. Cellular models for beta-cell function and diabetes gene therapy.

    Science.gov (United States)

    Green, A D; Vasu, S; Flatt, P R

    2018-03-01

    Diabetes is characterized by the destruction and/or relative dysfunction of insulin-secreting beta-cells in the pancreatic islets of Langerhans. Consequently, considerable effort has been made to understand the physiological processes governing insulin production and secretion in these cells and to elucidate the mechanisms involved in their deterioration in the pathogenesis of diabetes. To date, considerable research has exploited clonal beta-cell lines derived from rodent insulinomas. Such cell lines have proven to be a great asset in diabetes research, in vitro drug testing, and studies of beta-cell physiology and provide a sustainable, and in many cases, more practical alternative to the use of animals or primary tissue. However, selection of the most appropriate rodent beta cell line is often challenging and no single cell line entirely recapitulates the properties of human beta-cells. The generation of stable human beta-cell lines would provide a much more suitable model for studies of human beta-cell physiology and pathology and could potentially be used as a readily available source of implantable insulin-releasing tissue for cell-based therapies of diabetes. In this review, we discuss the history, development, functional characteristics and use of available clonal rodent beta-cell lines, as well as reflecting on recent advances in the generation of human-derived beta-cell lines, their use in research studies and their potential for cell therapy of diabetes. © 2017 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

  16. Absence of cannabinoid 1 receptor in beta cells protects against high-fat/high-sugar diet-induced beta cell dysfunction and inflammation in murine islets.

    Science.gov (United States)

    González-Mariscal, Isabel; Montoro, Rodrigo A; Doyle, Máire E; Liu, Qing-Rong; Rouse, Michael; O'Connell, Jennifer F; Santa-Cruz Calvo, Sara; Krzysik-Walker, Susan M; Ghosh, Soumita; Carlson, Olga D; Lehrmann, Elin; Zhang, Yongqing; Becker, Kevin G; Chia, Chee W; Ghosh, Paritosh; Egan, Josephine M

    2018-03-01

    The cannabinoid 1 receptor (CB1R) regulates insulin sensitivity and glucose metabolism in peripheral tissues. CB1R is expressed on pancreatic beta cells and is coupled to the G protein Gαi, suggesting a negative regulation of endogenous signalling in the beta cell. Deciphering the exact function of CB1R in beta cells has been confounded by the expression of this receptor on multiple tissues involved in regulating metabolism. Thus, in models of global genetic or pharmacological CB1R blockade, it is difficult to distinguish the indirect effects of improved insulin sensitivity in peripheral tissues from the direct effects of inhibiting CB1R in beta cells per se. To assess the direct contribution of beta cell CB1R to metabolism, we designed a mouse model that allows us to determine the role of CB1R specifically in beta cells in the context of whole-body metabolism. We generated a beta cell specific Cnr1 (CB1R) knockout mouse (β-CB1R -/- ) to study the long-term consequences of CB1R ablation on beta cell function in adult mice. We measured beta cell function, proliferation and viability in these mice in response to a high-fat/high-sugar diet and induction of acute insulin resistance with the insulin receptor antagonist S961. β-CB1R -/- mice had increased fasting (153 ± 23% increase at 10 weeks of age) and stimulated insulin secretion and increased intra-islet cAMP levels (217 ± 33% increase at 10 weeks of age), resulting in primary hyperinsulinaemia, as well as increased beta cell viability, proliferation and islet area (1.9-fold increase at 10 weeks of age). Hyperinsulinaemia led to insulin resistance, which was aggravated by a high-fat/high-sugar diet and weight gain, although beta cells maintained their insulin secretory capacity in response to glucose. Strikingly, islets from β-CB1R -/- mice were protected from diet-induced inflammation. Mechanistically, we show that this is a consequence of curtailment of oxidative stress and reduced activation of

  17. 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.

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

    International Nuclear Information System (INIS)

    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.

    2010-01-01

    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 ( 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). 14 C levels were then determined using accelerator mass spectrometry (AMS). Cellular 'birth date' was determined by comparing the subject's DNA 14 C content relative to a well-established 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 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.

  19. Quantitative mass spectrometry of diabetic kidney tubules identifies GRAP as a novel regulator of TGF-beta signaling.

    Science.gov (United States)

    Cummins, Timothy D; Barati, Michelle T; Coventry, Susan C; Salyer, Sarah A; Klein, Jon B; Powell, David W

    2010-04-01

    The aim of this study was to define novel mediators of tubule injury in diabetic kidney disease. For this, we used state-of-the-art proteomic methods combined with a label-free quantitative strategy to define protein expression differences in kidney tubules from transgenic OVE26 type 1 diabetic and control mice. The analysis was performed with diabetic samples that displayed a pro-fibrotic phenotype. We have identified 476 differentially expressed proteins. Bioinformatic analysis indicated several clusters of regulated proteins in relevant functional groups such as TGF-beta signaling, tight junction maintenance, oxidative stress, and glucose metabolism. Mass spectrometry detected expression changes of four physiologically relevant proteins were confirmed by immunoblot analysis. Of these, the Grb2-related adaptor protein (GRAP) was up-regulated in kidney tubules from diabetic mice and fibrotic kidneys from diabetic patients, and subsequently confirmed as a novel component of TGF-beta signaling in cultured human renal tubule cells. Thus, indicating a potential novel role for GRAP in TGF-beta-induced tubule injury in diabetic kidney disease. Although we targeted a specific disease, this approach offers a robust, high-sensitivity methodology that can be applied to the discovery of novel mediators for any experimental or disease condition. Copyright 2009 Elsevier B.V. All rights reserved.

  20. Acquired TGF beta 1 sensitivity and TGF beta 1 expression in cell lines established from a single small cell lung cancer patient during clinical progression

    DEFF Research Database (Denmark)

    Nørgaard, P; Damstrup, L; Rygaard, K

    1996-01-01

    Three small cell lung cancer cell lines established from a single patient during longitudinal follow-up were examined for in vitro expression of TGF beta and TGF beta receptors, i.e. the components of an autocrine loop. GLC 14 was established prior to treatment, GLC 16 on relapse after chemotherapy...... was found in GLC 16 and GLC 19. These cell lines were also growth inhibited by exogenously administrated TGF beta 1. TGF beta 1 mRNA and protein in its latent form was only expressed in the radiotherapy-resistant cell line, GLC 19. The results indicate that disease progression in this patient was paralleled...... II receptor gene, as examined by Southern blotting. Also, the type I receptor could not be detected by ligand binding assay in this cell line, despite expression of mRNA for this receptor. This agrees with previous findings that type I receptor cannot bind TGF beta 1 without co-expression of the type...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-01-01

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

  2. Hydroxyurea responses in clinically varied beta, HbE-beta thalassaemia and sickle cell anaemia patients of Eastern India.

    Science.gov (United States)

    Chatterjee, Tridip; Chakravarty, Amit; Chakravarty, Sudipa

    2018-02-17

    The haematological and clinical response to hydroxyurea was estimated in HbE-beta, beta thalassaemia and sickle cell anaemia patients of Eastern India, with variable clinical severity and transfusion requirement to determine whether hydroxyurea can help these patients to maintain their steady haemoglobin level without blood transfusions. Three hundred patients (189 HbE-beta thalassaemia, 95 beta thalassaemia and 16 other haemoglobinopathies including sickle cell anaemia) were selected for hydroxyurea therapy and were followed up for 48-60 months. Results suggest significant response to hydroxyurea therapy in 19 beta and 99 HbE-beta patients in the transfusion-dependent group (GR-I). All of them became transfusion-independent while on hydroxyurea therapy. The majority of responding patients were IVS1-5(G-C) in one of their alleles in HbE-beta cases (83 out of 119). Though IVS1-5(G-C) was found to be the commonest mutation in our selected patients, the mutational background of the patients does not found to have any significant correlation with the response category towards hydroxyurea as per the results observed in our study. But, the drug works pretty well in most of the transfusion-dependent patients, as these patients were withdrawn from regular blood transfusion. At the same time, partial or no response to the drug hydroxyurea was also recorded in our study.

  3. Neutrinoless Double Beta Decay and Lepton Flavour Violation in Broken μ - τ Symmetric Neutrino Mass Models

    Science.gov (United States)

    Borgohain, Happy; Das, Mrinal Kumar

    2017-09-01

    We have studied neutrinoless double beta decay and charged lepton flavour violation in broken μ - τ symmetric neutrino masses in a generic left-right symmetric model (LRSM). The leading order μ - τ symmetric mass matrix originates from the type I (II) seesaw mechanism, whereas the perturbations to μ - τ symmetry in order for generation of non-zero reactor mixing angle 𝜃 13, as required by latest neutrino oscillation data, originates from the type II (I) seesaw mechanism. In our work, we considered four different realizations of μ - τ symmetry, viz. Tribimaximal Mixing (TBM), Bimaximal Mixing (BM), Hexagonal Mixing (HM) and Golden Ratio Mixing (GRM). We then studied the new physics contributions to neutrinoless double beta decay (NDBD) ignoring the left-right gauge boson mixing and the heavy-light neutrino mixing within the framework of LRSM. We have considered the mass of the gauge bosons and scalars to be around TeV and studied the effects of the new physics contributions on the effective mass and the NDBD half life and compared with the current experimental limit imposed by KamLAND-Zen. We further extended our analysis by correlating the lepton flavour violation of the decay processes, ( μ → 3 e) and ( μ → e γ) with the lightest neutrino mass and atmospheric mixing angle 𝜃 23 respectively.

  4. Cdc42 controls progenitor cell differentiation and beta-catenin turnover in skin

    DEFF Research Database (Denmark)

    Wu, Xunwei; Quondamatteo, Fabio; Lefever, Tine

    2006-01-01

    Differentiation of skin stem cells into hair follicles (HFs) requires the inhibition of beta-catenin degradation, which is controlled by a complex containing axin and the protein kinase GSK3beta. Using conditional gene targeting in mice, we show now that the small GTPase Cdc42 is crucial...... for differentiation of skin progenitor cells into HF lineage and that it regulates the turnover of beta-catenin. In the absence of Cdc42, degradation of beta-catenin was increased corresponding to a decreased phosphorylation of GSK3beta at Ser 9 and an increased phosphorylation of axin, which is known to be required...... progenitor cells in vivo....

  5. Do post-translational beta cell protein modifications trigger type 1 diabetes?

    DEFF Research Database (Denmark)

    Størling, Joachim; Overgaard, Anne Julie; Brorsson, Caroline Anna

    2013-01-01

    Type 1 diabetes is considered an autoimmune disease characterised by specific T cell-mediated destruction of the insulin-producing beta cells. Yet, except for insulin, no beta cell-specific antigens have been discovered. This may imply that the autoantigens in type 1 diabetes exist in modified...... forms capable of specifically triggering beta cell destruction. In other immune-mediated diseases, autoantigens targeted by the immune system have undergone post-translational modification (PTM), thereby creating tissue-specific neo-epitopes. In a similar manner, PTM of beta cell proteins might create...... beta cell-specific neo-epitopes. We suggest that the current paradigm of type 1 diabetes as a classical autoimmune disease should be reconsidered since the immune response may not be directed against native beta cell proteins. A modified model for the pathogenetic events taking place in islets leading...

  6. Pancreatic α-cell mass in obesity

    NARCIS (Netherlands)

    Ellenbroek, Johanne H; Töns, Hendrica A M; Hanegraaf, Maaike A J; Rabelink, Ton J; Engelse, Marten A; Carlotti, Françoise; de Koning, Eelco J P

    2017-01-01

    While it is well recognized that obesity is associated with an increased β-cell mass, the association with α-cell mass is less clear. Type 2 diabetes (T2DM) associated with obesity is a bihormonal disease characterized by inadequate insulin secretion and hyperglucagonaemia. We examined β- and α-cell

  7. Lipids and immunoinflammatory pathways of beta cell destruction

    Science.gov (United States)

    Imai, Yumi; Dobrian, Anca D.; Morris, Margaret A.; Taylor-Fishwick, David A.; Nadler, Jerry L.

    2016-01-01

    Islet inflammation contributes to beta cell demise in both type 1 and type 2 diabetes. 12-Lipoxygenase (12-LO, gene expressed as ALOX12 in human and 12-Lo in rodents in this manuscript) produces proinflammatory metabolites such as 12(S)-hydroxyeicosatetraenoic acids through dioxygenation of polyunsaturated fatty acids. 12-LO was first implicated in diabetes when the increase in 12-Lo expression and 12(S)-hydroxyeicosatetraenoic acid was noted in rodent models of diabetes. Subsequently, germline 12-Lo−/− was shown to prevent the development of hyperglycemia in mouse models of type 1 diabetes and in high-fat fed mice. More recently, beta cell-specific 12-Lo−/− was shown to protect mice against hyperglycaemia after streptozotocin and a high-fat diet. In humans, 12-LO expression is increased in pancreatic islets of autoantibody-positive, type 1 diabetic and type 2 diabetic organ donors. Interestingly, the high expression of ALOX12 is associated with the alteration in first-phase glucose-stimulated insulin secretion in human type 2 diabetic islets. To further clarify the role of islet 12-LO in diabetes and to validate 12-LO as a therapeutic target of diabetes, we have studied selective pharmacologic inhibitors for 12-LO. The compounds we have identified show promise: they protect beta cell lines and human islets from apoptosis and preserve insulin secretion when challenged by proinflammatory cytokine mixture. Currently studies are underway to test the compounds in mouse models of diabetes. This review summarizes a presentation given at the ‘Islet inflammation in type 2 diabetes’ symposium at the 2015 annual meeting of the EASD. It is accompanied two other mini-reviews on topics from this symposium (by Simone Baltrusch, DOI: XXX and Marc Donath, DOI: XXX) and a commentary by the Session Chair, Piero Marchetti (DOI: XXX). PMID:26868492

  8. Expression and functional importance of collagen-binding integrins, alpha 1 beta 1 and alpha 2 beta 1, on virus-activated T cells

    DEFF Research Database (Denmark)

    Andreasen, Susanne Ø; Thomsen, Allan R; Koteliansky, Victor E

    2003-01-01

    decreased responses were seen upon transfer of alpha(1)-deficient activated/memory T cells. Thus, expression of alpha(1)beta(1) and alpha(2)beta(1) integrins on activated T cells is directly functionally important for generation of inflammatory responses within tissues. Finally, the inhibitory effect......Adhesive interactions are crucial to cell migration into inflammatory sites. Using murine lymphocytic choriomeningitis virus as an Ag model system, we have investigated expression and function of collagen-binding integrins, alpha(1)beta(1) and alpha(2)beta(1), on activated and memory T cells. Using...... this system and MHC tetramers to define Ag-specific T cells, we demonstrate that contrary to being VLAs, expression of alpha(1)beta(1) and alpha(2)beta(1) can be rapidly induced on acutely activated T cells, that expression of alpha(1)beta(1) remains elevated on memory T cells, and that expression of alpha(1...

  9. Beta-interferon inhibits cell infection by Trypanosoma cruzi

    Science.gov (United States)

    Kierszenbaum, F.; Sonnenfeld, G.

    1984-01-01

    Beta interferon has been shown to inhibit the capacity of bloodstream forms of the flagellate Trypanosoma cruzi, the causative agent of Chagas' disease, to associate with and infect mouse peritoneal macrophages and rat heart myoblasts. The inhibitory effect was abrogated in the presence of specific antibodies to the interferon. Pretreatment of the parasites with interferon reduced their infectivity for untreated host cells, whereas pretreament of either type of host cell did not affect the interaction. The effect of interferon on the trypanosomes was reversible; the extent of the inhibitory effect was significantly reduced afer 20 min, and was undetectable after 60 min when macrophages were used as host cells. For the myoblasts, 60 min elapsed before the inhibitory effect began to subside and 120 min elapsed before it became insignificant or undetectable.

  10. Cocoa Phenolic Extract Protects Pancreatic Beta Cells against Oxidative Stress

    Directory of Open Access Journals (Sweden)

    Laura Bravo

    2013-07-01

    Full Text Available Diabetes mellitus is associated with reductions in glutathione, supporting the critical role of oxidative stress in its pathogenesis. Antioxidant food components such as flavonoids have a protective role against oxidative stress-induced degenerative and age-related diseases. Flavonoids constitute an important part of the human diet; they can be found in most plant foods, including green tea, grapes or cocoa and possess multiple biological activities. This study investigates the chemo-protective effect of a cocoa phenolic extract (CPE containing mainly flavonoids against oxidative stress induced by tert-butylhydroperoxide (t-BOOH on Ins-1E pancreatic beta cells. Cell viability and oxidative status were evaluated. Ins-1E cells treatment with 5–20 μg/mL CPE for 20 h evoked no cell damage and did not alter ROS production. Addition of 50 μM t-BOOH for 2 h increased ROS and carbonyl groups content and decreased reduced glutathione level. Pre-treatment of cells with CPE significantly prevented the t-BOOH-induced ROS and carbonyl groups and returned antioxidant defences to adequate levels. Thus, Ins-1E cells treated with CPE showed a remarkable recovery of cell viability damaged by t-BOOH, indicating that integrity of surviving machineries in the CPE-treated cells was notably protected against the oxidative insult.

  11. Massive parallel gene expression profiling of RINm5F pancreatic islet beta-cells stimulated with interleukin-1beta

    DEFF Research Database (Denmark)

    Rieneck, K; Bovin, L F; Josefsen, K

    2000-01-01

    found that 146 full-length genes and a large number of expressed sequence tags were differentially regulated 3-fold or more. Most of the differentially regulated transcripts have not previously been described to be regulated by IL-1beta in beta-cells. We have analysed the expression data and sorted......Interleukin 1 (IL-1) is a pleiotropic cytokine with the potential to kill pancreatic beta-cells, and this unique property is thought to be involved in the pathogenesis of type I diabetes mellitus. We therefore determined the quantitative expression of 24,000 mRNAs of RINm5F, an insulinoma cell line...... derived from rat pancreatic beta-cells, before and after challenge with 30 and 1,000 pg/ml of recombinant human IL-1beta. The highest concentration resulted in decreased insulin production and cell death over a period of 4 days. Using three different time points, 2, 4 and 24 hours after challenge, we...

  12. Physical consequences of the alpha/beta rule which accurately calculates particle masses

    Energy Technology Data Exchange (ETDEWEB)

    Greulich, Karl Otto [Fritz Lipmann Institute, Beutenbergstr.11, D07745 Jena (Germany)

    2015-07-01

    Using the fine structure constant α (=1/137.036), the proton vs. electron mass ratio β (= 1836.2) and the integers m and n, the α/β rule: m{sub particle} = α{sup -n} x β m x 27.2 eV/c{sup 2} allows almost exact calculation of particle masses. (K.O.Greulich, DPG Spring meeting 2014, Mainz, T99.4) With n=2, m=0 the electron mass becomes 510.79 keV/c{sup 2} (experimental 511 keV/c{sup 2}) With n=2, m=1 the proton mass is 937.9 MeV/c{sup 2} (literature 938.3 MeV/c{sup 2}). For n=3 and m=1 a particle with 128.6 GeV/c{sup 2} close to the reported Higgs mass, is expected. For n=14 and m=-1 the Planck mass results. The calculated masses for gauge bosons and for quarks have similar accuracy. All masses fit into the same scheme (the alpha/beta rule), indicating that non of these particle masses play an extraordinary role. Particularly, the Higgs Boson, often termed the *God particle* plays in this sense no extraordinary role. In addition, particle masses are intimately correlated with the fine structure constant α. If particle masses have been constant over all times, α must have been constant over these times. In addition, the ionization energy of the hydrogen atom (13.6 eV) needs to have been constant if particle masses have been unchanged or vice versa. In conclusion, the α/β rule needs to be taken into account when cosmological models are developed.

  13. The Importance of REST for Development and Function of Beta Cells

    DEFF Research Database (Denmark)

    Martin, David; Grapin-Botton, Anne

    2017-01-01

    these, the transcriptional repressor RE-1 Silencing Transcription factor (REST) is expressed in most cells of the body, excluding most populations of neurons, as well as pancreatic beta and alpha cells. In the cell types where it is expressed, REST represses the expression of hundreds of genes......Beta cells are defined by the genes they express, many of which are specific to this cell type, and ensure a specific set of functions. Beta cells are also defined by a set of genes they should not express (in order to function properly), and these genes have been called forbidden genes. Among...... is expressed in the progenitors of both neurons and beta cells during development, but it is down-regulated as the cells differentiate. Although REST mutations and deregulation have yet to be connected to diabetes in humans, REST activation during both development and in adult beta cells leads to diabetes...

  14. Beta-lactamase induction and cell wall metabolism in Gram-negative bacteria

    Science.gov (United States)

    Zeng, Ximin; Lin, Jun

    2013-01-01

    Production of beta-lactamases, the enzymes that degrade beta-lactam antibiotics, is the most widespread and threatening mechanism of antibiotic resistance. In the past, extensive research has focused on the structure, function, and ecology of beta-lactamases while limited efforts were placed on the regulatory mechanisms of beta-lactamases. Recently, increasing evidence demonstrate a direct link between beta-lactamase induction and cell wall metabolism in Gram-negative bacteria. Specifically, expression of beta-lactamase could be induced by the liberated murein fragments, such as muropeptides. This article summarizes current knowledge on cell wall metabolism, beta-lactam antibiotics, and beta-lactamases. In particular, we comprehensively reviewed recent studies on the beta-lactamase induction by muropeptides via two major molecular mechanisms (the AmpG–AmpR–AmpC pathway and BlrAB-like two-component regulatory system) in Gram-negative bacteria. The signaling pathways for beta-lactamase induction offer a broad array of promising targets for the discovery of new antibacterial drugs used for combination therapies. Therefore, to develop effective mitigation strategies against the widespread beta-lactam resistance, examination of the molecular basis of beta-lactamase induction by cell wall fragment is highly warranted. PMID:23734147

  15. Regulation of laminin beta2 chain gene expression in human cancer cell lines

    DEFF Research Database (Denmark)

    Durkin, M E; Nielsen, F C; Loechel, F

    2001-01-01

    and clone A colon carcinoma cells express the laminin beta2 chain mRNA, but only the A204 cells secrete laminin heterotrimers containing the beta2 chain. Segments of the beta2 chain gene promoter region were cloned into luciferase reporter vectors, and their ability to stimulate transcription was tested...... nucleotides -667 to -1724. Genomic DNA at the 3' end of the gene also appeared to have enhancer activity, as a 1.1-kb fragment located downstream of the last exon stimulated the luciferase activity of the nucleotides -667/+297 promoter segment approximately threefold. Alternative splicing of the first intron...... of the human laminin beta2 chain gene generates two isoforms of the 5' untranslated region of the beta2 chain mRNA. The translational efficiencies of the two laminin beta2 chain leaders did not differ significantly, when assayed by polysome profile analysis of endogenous clone A cell beta2 chain m...

  16. Determination of the Electron Neutrino Mass from Experiments on Electron-Capture Beta-Decay (EC)

    CERN Multimedia

    2002-01-01

    The aim of the programme is to measure the electron-neutrino mass, for which at present an upper limit of 500~eV is known. \\\\ \\\\ The experiment studies the shape of the internal bremsstrahlung spectrum in electron-capture near its upper end-point and deduces a mass from small shape changes completely analogous to those in the well-known determination of the electron antineutrino mass in the tritium beta-minus decay. \\\\ \\\\ In a low-energy bremsstrahlung process, the capture takes place from a virtual S state associated with a radiative P~@A~S electromagnetic transition, and the resonant nature of the process leads to important enhancements of the photon intensities at low energy, in particular near the resonance energies co (X-rays). This effect gives this type of experiment a chance to compete with experiments on continuous beta spectra. \\\\ \\\\ The programme concentrates on two long-lived isotopes: \\\\ \\\\ 1)~~|1|6|3Ho. The Q value for this isotope has been found to be 2.6-2.7 keV. A detector specially construct...

  17. Few active mechanisms of the neutrinoless double beta-decay and effective mass of Majorana neutrinos

    CERN Document Server

    Simkovic, Fedor; Faessler, Amand

    2010-01-01

    It is well known that there exist many mechanisms that may contribute to neutrinoless double beta decay (0nbb-decay). By exploiting the fact that the associated nuclear matrix elements are target dependent we show that, given definite experimental results on a sufficient number of targets, one can determine or sufficiently constrain all lepton violating parameters including the mass term. As a specific example we show that, assuming the observation of the 0nbb-decay in three different nuclei, e.g., 76Ge, 100Mo and 130Te, and just three lepton number violating mechanisms (light and heavy neutrino mass mechanisms as well as R-parity breaking SUSY mechanism) being active, there are only four different solutions for the lepton violating parameters, provided that they are relatively real. In particular, assuming evidence of the 0nbb-decay of 76Ge, the effective neutrino Majorana mass |m_bb| can be almost uniquely extracted by utilizing other existing constraints (cosmological observations and tritium beta-decay ex...

  18. Structural studies of the mix-linked beta-(1-->3)/beta-(1-->4)-D-xylans from the cell wall of Palmaria palmata (Rhodophyta).

    Science.gov (United States)

    Deniaud, Estelle; Quemener, Bernard; Fleurence, Joël; Lahaye, Marc

    2003-11-01

    The structure and organization of Palmaria palmata cell walls, which are largely involved in biological and physiological functions as well as in biotechnological and food applications of this red marine alga, are principally assumed by the interactions and linkages of major mix-linked beta-(1-->3)/beta-(1-->4)-D-xylans. These partly acidic polysaccharides are essentially held in the cell wall by H-bonds. The location of the acid groups and the distribution of 1-->3-linkage were studied following the endo-beta-(1,4)-xylanase hydrolysis of sequentially extracted xylans, and fine analysis of the oligosaccharides produced by anion exchange chromatography, high performance anion exchange chromatography (HPAEC)-PAD, nuclear magnetic resonance (NMR) and electrospray ion trap mass spectrometry (ESI-MS) techniques. The results indicate that the acidity of the xylans was related to potential linkages to sulfated and/or phosphorylated xylogalactoprotein complexes. H-bonding of the mix-linked xylans involved a regular 1,3-linkages distribution idealized in a pentameric repeating structure (one 1,3-linkage and four 1,4-linkages). Furthermore, MS analysis of the xylo-oligosaccharides revealed a substitution of the mix-linked xylans by a non-osidic component of 175 g mol(-1). The presence of this substituent and of the proposed covalent linkage between the mix-linked xylans and charged glycoproteins are discussed with regard to the polysaccharides interactions in P. palmata cell walls.

  19. Pancreatic Beta-Cell Purification by Altering FAD and NAD(PH Metabolism

    Directory of Open Access Journals (Sweden)

    P. de Vos

    2008-07-01

    Full Text Available Isolation of primary beta cells from other cells within in the pancreatic islets is of importance for many fields of islet research. However, up to now, no satisfactory method has been developed that gained high numbers of viable beta cells, without considerable alpha-cell contamination. In this study, we investigated whether rat beta cells can be isolated from nonbeta endocrine cells by manipulating the flavin adenine dinucleotide (FAD and nicotinamide-adenine dinucleotide phosphate (NAD(PH autofluorescence. Beta cells were isolated from dispersed islets by flow cytometry, based on their high FAD and NAD(PH fluorescence. To improve beta cell yield and purity, the cellular FAD and NAD(PH contents were altered by preincubation in culture media containing varying amounts of D-glucose and amino acids. Manipulation of the cellular FAD and NAD(PH fluorescence improves beta cell yield and purity after sorting. This method is also a fast and reliable method to measure beta cell functional viability. A conceivable application is assessing beta cell viability before transplantation.

  20. APPL1 prevents pancreatic beta cell death and inflammation by dampening NFκB activation in a mouse model of type 1 diabetes.

    Science.gov (United States)

    Jiang, Xue; Zhou, Yawen; Wu, Kelvin K L; Chen, Zhanrui; Xu, Aimin; Cheng, Kenneth K Y

    2017-03-01

    Beta cell inflammation and demise is a feature of type 1 diabetes. The insulin-sensitising molecule 'adaptor protein, phosphotyrosine interacting with PH domain and leucine zipper 1' (APPL1), which contains an NH 2 -terminal Bin/Amphiphysin/Rvs domain, a central pleckstrin homology domain and a COOH-terminal phosphotyrosine-binding domain, has been shown to modulate inflammatory response in various cell types but its role in regulating beta cell mass and inflammation in type 1 diabetes remains unknown. Thus, we investigated whether APPL1 prevents beta cell apoptosis and inflammation in diabetes. Appl1-knockout mice and their wild-type littermates, as well as C57BL/6N mice injected with adeno-associated virus encoding APPL1 or green fluorescent protein, were treated with multiple-low-dose streptozotocin (MLDS) to induce experimental type 1 diabetes. Their glucose metabolism and beta cell function were assessed. The effect of APPL1 deficiency on beta cell function upon exposure to a diabetogenic cytokine cocktail (CKS; consisting of TNF-α, IL-1β and IFN-γ) was assessed ex vivo. Expression of APPL1 was significantly reduced in pancreatic islets from mouse models of type 1 diabetes or islets treated with CKS. Hyperglycaemia, beta cell loss and insulitis induced by MLDS were exacerbated by genetic deletion of Appl1 but were alleviated by beta cell-specific overexpression of APPL1. APPL1 preserved beta cell mass by reducing beta cell apoptosis upon treatment with MLDS. Mechanistically, APPL1 deficiency potentiate CKS-induced phosphorylation of NFκB inhibitor, α (IκBα) and subsequent phosphorylation and transcriptional activation of p65, leading to a dramatic induction of NFκB-regulated apoptotic and proinflammatory programs in beta cells. Pharmacological inhibition of NFκB or inducible NO synthase (iNOS) largely abrogate the detrimental effects of APPL1 deficiency on beta cell functions. APPL1 negatively regulates inflammation and apoptosis in pancreatic beta

  1. Balsamic Vinegar Improves High Fat-Induced Beta Cell Dysfunction via Beta Cell ABCA1

    Directory of Open Access Journals (Sweden)

    Hannah Seok

    2012-08-01

    Full Text Available BackgroundThe aim of this study was to investigate the effects of balsamic vinegar on β-cell dysfunction.MethodsIn this study, 28-week-old Otsuka Long-Evans Tokushima Fatty (OLETF rats were fed a normal chow diet or a high-fat diet (HFD and were provided with tap water or dilute balsamic vinegar for 4 weeks. Oral glucose tolerance tests and histopathological analyses were performed thereafter.ResultsIn rats fed both the both chow diet and the HFD, the rats given balsamic vinegar showed increased insulin staining in islets compared with tap water administered rats. Balsamic vinegar administration also increased β-cell ATP-binding cassette transporter subfamily A member 1 (ABCA1 expression in islets and decreased cholesterol levels.ConclusionThese findings provide the first evidence for an anti-diabetic effect of balsamic vinegar through improvement of β-cell function via increasing β-cell ABCA1 expression.

  2. Curcumin inhibition of integrin (alpha6beta4)-dependent breast cancer cell motility and invasion.

    Science.gov (United States)

    Kim, Hong Im; Huang, Huang; Cheepala, Satish; Huang, Shile; Chung, Jun

    2008-10-01

    Curcumin, a polyphenol natural product isolated from the rhizome of the plant Curcuma longa, has emerged as a promising anticancer therapeutic agent. However, the mechanism by which curcumin inhibits cancer cell functions such as cell growth, survival, and cell motility is largely unknown. We explored whether curcumin affects the function of integrin alpha(6)beta(4), a laminin adhesion receptor with an established role in invasion and migration of cancer cells. Here we show that curcumin significantly reduced alpha(6)beta(4)-dependent breast cancer cell motility and invasion in a concentration-dependent manner without affecting apoptosis in MDA-MB-435/beta4 (beta(4)-integrin transfectants) and MDA-MB-231 breast cancer cell lines. Further, curcumin selectively reduced the basal phosphorylation of beta(4) integrin (Y1494), which has been reported to be essential in mediating alpha(6)beta(4)-dependent phosphatidylinositol 3-kinase activation and cell motility. Consistent with this finding, curcumin also blocked alpha(6)beta(4)-dependent Akt activation and expression of the cell motility-promoting factor ENPP2 in MDA-MB-435/beta4 cell line. A multimodality approach using curcumin in combination with other pharmacologic inhibitors of alpha(6)beta(4) signaling pathways showed an additive effect to block breast cancer cell motility and invasion. Taken together, these findings show that curcumin inhibits breast cancer cell motility and invasion by directly inhibiting the function of alpha(6)beta(4) integrin, and suggest that curcumin can serve as an effective therapeutic agent in tumors that overexpress alpha(6)beta(4).

  3. Mass measurement project by determination of Q{sub {beta}} for neutron-rich nuclei; Projet de mesure des masses par determination des Q{sub {beta}} pour des noyaux tres riches en neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Pautrat, M.; Lagrange, J.M.; Petizon, L. [Paris-11 Univ., 91 - Orsay (France). Inst. de Physique Nucleaire; Vanhorenbeeck, J.; Duhamel, P. [Brussels Univ. (Belgium). Inst. d`Astronomie et d`Astrophysique; Binon, F. [Universite Libre de Bruxelles (Belgium)

    1993-12-31

    The aim of the project described hereafter is to collect new data on the exotic neutron rich nuclei of the Fe to Zn region, and in particular to determine their masses, for both nuclear physics and astrophysics purposes. These isotopes will be produced through projectile fragmentation at the GANIL facility and selected by the LISE3 spectrometer. Their half-lives will be measured as well as the energy of their main {gamma} rays; {gamma} - {gamma} coincidences will then allow to build a preliminary level scheme. The analysis of {beta} spectra and {beta} - {gamma} coincidences will finally provide the maximum {beta} decay energies of the studied nuclei leading to their masses. The difficulties arising from the low production rates, the {beta} detection, the data handling are discussed together with the solutions proposed to overcome them. (authors). 17 refs.

  4. Nuclear orphan receptor TLX affects gene expression, proliferation and cell apoptosis in beta cells

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Xiaoli; Xiong, Xiaokan; Dai, Zhe; Deng, Haohua; Sun, Li; Hu, Xuemei; Zhou, Feng; Xu, Yancheng, E-mail: oxyccc@163.com

    2015-12-04

    Nuclear orphan receptor TLX is an essential regulator of the growth of neural stem cells. However, its exact function in pancreatic islet cells is still unknown. In the present study, gene expression profiling analysis revealed that overexpression of TLX in beta cell line MIN6 causes suppression of 176 genes and upregulation of 49 genes, including a cadre of cell cycle, cell proliferation and cell death control genes, such as Btg2, Ddit3 and Gadd45a. We next examined the effects of TLX overexpression on proliferation, apoptosis and insulin secretion in MIN6 cells. Proliferation analysis using EdU assay showed that overexpression of TLX increased percentage of EdU-positive cells. Cell cycle and apoptosis analysis revealed that overexpression of TLX in MIN6 cells resulted in higher percentage of cells exiting G1 into S-phase, and a 58.8% decrease of cell apoptosis induced by 0.5 mM palmitate. Moreover, TLX overexpression did not cause impairment of insulin secretion. Together, we conclude that TLX is among factors capable of controlling beta cell proliferation and survival, which may serve as a target for the development of novel therapies for diabetes. - Highlights: • TLX overexpression in MIN6 cell causes significant expression changes of 225 genes. • TLX overexpression promotes MIN6 cell proliferation and decreases cell apoptosis. • TLX overexpression does not cause impairment of insulin secretion.

  5. Nuclear orphan receptor TLX affects gene expression, proliferation and cell apoptosis in beta cells

    International Nuclear Information System (INIS)

    Shi, Xiaoli; Xiong, Xiaokan; Dai, Zhe; Deng, Haohua; Sun, Li; Hu, Xuemei; Zhou, Feng; Xu, Yancheng

    2015-01-01

    Nuclear orphan receptor TLX is an essential regulator of the growth of neural stem cells. However, its exact function in pancreatic islet cells is still unknown. In the present study, gene expression profiling analysis revealed that overexpression of TLX in beta cell line MIN6 causes suppression of 176 genes and upregulation of 49 genes, including a cadre of cell cycle, cell proliferation and cell death control genes, such as Btg2, Ddit3 and Gadd45a. We next examined the effects of TLX overexpression on proliferation, apoptosis and insulin secretion in MIN6 cells. Proliferation analysis using EdU assay showed that overexpression of TLX increased percentage of EdU-positive cells. Cell cycle and apoptosis analysis revealed that overexpression of TLX in MIN6 cells resulted in higher percentage of cells exiting G1 into S-phase, and a 58.8% decrease of cell apoptosis induced by 0.5 mM palmitate. Moreover, TLX overexpression did not cause impairment of insulin secretion. Together, we conclude that TLX is among factors capable of controlling beta cell proliferation and survival, which may serve as a target for the development of novel therapies for diabetes. - Highlights: • TLX overexpression in MIN6 cell causes significant expression changes of 225 genes. • TLX overexpression promotes MIN6 cell proliferation and decreases cell apoptosis. • TLX overexpression does not cause impairment of insulin secretion.

  6. Bmal1 and Beta cell clock are required for adaptation to circadian disruption, and their loss of function leads to oxidative stress-induced Beta cell failure in mice

    Science.gov (United States)

    Circadian disruption has deleterious effects on metabolism. Global deletion of Bmal1, a core clock gene, results in Beta cell dysfunction and diabetes. However, it is unknown if this is due to loss of cell-autonomous function of Bmal1 in Beta cells. To address this, we generated mice with Beta cell ...

  7. Structure of the T cell receptor in a Ti alpha V beta 2, alpha V beta 8-positive T cell line

    DEFF Research Database (Denmark)

    Hou, X; Dietrich, J; Kuhlmann, J

    1994-01-01

    not known; however, it has been suggested that each TcR contains two Ti dimers. To gain insight into the structure of the TcR we constructed a Ti alpha V beta 2, alpha V beta 8-positive T cell line which expressed the endogenous human TiV beta 8 and the transfected mouse TiV beta 2 both in association......The T cell receptor (TcR) is composed of at least six different polypeptide chains consisting of the clonotypic Ti heterodimer (Ti alpha beta or Ti gamma delta) and the noncovalently associated CD3 chains (CD3 gamma delta epsilon zeta). The exact number of subunits constituting the TcR is still...... with the endogenous Ti alpha and CD3 chains at the cell surface. Preclearing experiments with radioiodinated cell lysate prepared with digitonin lysis buffer demonstrated that depleting the lysate of Ti alpha V beta 8 by immunoprecipitation with anti V beta 8 monoclonal antibody (mAb) did not reduce the amount of Ti...

  8. Beta-type transforming growth factor specifies organizational behavior in vascular smooth muscle cell cultures.

    Science.gov (United States)

    Majack, R A

    1987-07-01

    In culture, vascular smooth muscle cells (SMC) grow in a "hill-and-valley" (multilayered) pattern of organization. We have studied the growth, behavioral organization, and biosynthetic phenotype of rat aortic SMC exposed to purified platelet-derived growth regulatory molecules. We show that multilayered growth is not a constitutive feature of cultured SMC, and that beta-type transforming growth factor (TGF-beta) is the primary determinant of multilayered growth and the hill-and-valley pattern of organization diagnostic for SMC in culture. TGF-beta inhibited, in a dose-dependent manner, the serum- or platelet-derived growth factor-mediated proliferation of these cells in two-dimensional culture, but only when cells were plated at subconfluent densities. The ability of TGF-beta to inhibit SMC growth was inversely correlated to plating cell density. When SMC were plated at monolayer density (5 X 10(4) cells/cm2) to allow maximal cell-to-cell contact, TGF-beta potentiated cell growth. This differential response of SMC to TGF-beta may contribute to the hill-and-valley pattern of organization. Unlike its effect on other cell types, TGF-beta did not enhance the synthesis of fibronectin or its incorporation into the extracellular matrix. However, the synthesis of a number of other secreted proteins was altered by TGF-beta treatment. SMC treated with TGF-beta for 4 or 8 h secreted markedly enhanced amounts of an Mr 38,000-D protein doublet whose synthesis is known to be increased by heparin (another inhibitor of SMC growth), suggesting metabolic similarities between heparin- and TGF-beta-mediated SMC growth inhibition. The data suggest that TGF-beta may play an important and complex regulatory role in SMC proliferation and organization during development and after vascular injury.

  9. Autoregulation of periodontal ligament cell phenotype and functions by transforming growth factor-beta1.

    Science.gov (United States)

    Brady, T A; Piesco, N P; Buckley, M J; Langkamp, H H; Bowen, L L; Agarwal, S

    1998-10-01

    During orthodontic tooth movement, mechanical forces acting on periodontal ligament (PDL) cells induce the synthesis of mediators which alter the growth, differentiation, and secretory functions of cells of the PDL. Since the cells of the PDL represent a heterogeneous population, we examined mechanically stress-induced cytokine profiles in three separate clones of human osteoblast-like PDL cells. Of the four pro-inflammatory cytokines investigated, only IL-6 and TGF-beta1 were up-regulated in response to mechanical stress. However, the expression of other pro-inflammatory cytokines such as IL-1 beta, TNF-alpha, or IL-8 was not observed. To understand the consequences of the increase in TGF-beta1 expression following mechanical stress, we examined the effect of TGF-beta1 on PDL cell phenotype and functions. TGF-beta1 was mitogenic to PDL cells at concentrations between 0.4 and 10 ng/mL. Furthermore, TGF-beta1 down-regulated the osteoblast-like phenotype of PDL cells, i.e., alkaline phosphatase activity, calcium phosphate nodule formation, expression of osteocalcin, and TGF-beta1, in a dose-dependent manner. Although initially TGF-beta1 induced expression of type I collagen mRNA, prolonged exposure to TGF-beta1 down-regulated the ability of PDL cells to express type I collagen mRNA. Our results further show that, within 4 hrs, exogenously applied TGF-beta1 down-regulated IL-6 expression in a dose-dependent manner, and this inhibition was sustained over a six-day period. In summary, the data suggest that mechanically stress-induced TGF-beta1 expression may be a physiological mechanism to induce mitogenesis in PDL cells while down-regulating its osteoblast-like features and simultaneously reducing the IL-6-induced bone resorption.

  10. Cx36 makes channels coupling human pancreatic beta-cells, and correlates with insulin expression

    NARCIS (Netherlands)

    Serre-Beinier, Veronique; Bosco, Domenico; Zulianello, Laurence; Charollais, Anne; Caille, Dorothee; Charpantier, Eric; Gauthier, Benoit R.; Diaferia, Giuseppe R.; Giepmans, Ben N.; Lupi, Roberto; Marchetti, Piero; Deng, Shaoping; Buhler, Leo; Berney, Thierry; Cirulli, Vincenzo; Meda, Paolo

    2009-01-01

    Previous studies have documented that the insulin-producing beta-cells of laboratory rodents are coupled by gap junction channels made solely of the connexin36 (Cx36) protein, and have shown that loss of this protein desynchronizes beta-cells, leading to secretory defects reminiscent of those

  11. Effect of iron on pancreatic beta cell function and insulin resistance

    African Journals Online (AJOL)

    Dr Olaleye

    the incidence of diabetes mellitus was investigated on the pancreatic beta cell function and insulin resistance in normal ... hyperglycaemia, insulin resistance, hyperinsulinaemia, inflammation and pancreatic beta cell dysfunction thus predisposing the ..... and antioxidant status in alpha-thalassemia major: iron overload and ...

  12. CRFR1 activation protects against cytokine-induced beta cell death

    DEFF Research Database (Denmark)

    Blaabjerg, Lykke; Christensen, Gitte Lund; Matsumoto, Masahito

    2014-01-01

    During diabetes development beta cells are exposed to elevated concentrations of proinflammatory cytokines, TNFα and IL-1β which in vitro, induce beta cell death. The class B G-protein-coupled receptors (GPCRs): Corticotropin releasing factor receptor 1 (CRFR1) and CRFR2 are expressed in pancreatic...

  13. Lysine deacetylase inhibition prevents diabetes by chromatin-independent immunoregulation and beta-cell protection

    NARCIS (Netherlands)

    Christensen, D.P.; Gysemans, C.; Lundh, M.; Dahllof, M.S.; Noesgaard, D.; Schmidt, S.F.; Mandrup, S; Birkbak, N.; Workman, C.T.; Piemonti, L.; Blaabjerg, L.; Monzani, V.; Fossati, G.; Mascagni, P.; Paraskevas, S.; Aikin, R.A.; Billestrup, N.; Grunnet, L.G.; Dinarello, C.A.; Mathieu, C.; Mandrup-Poulsen, T.

    2014-01-01

    Type 1 diabetes is due to destruction of pancreatic beta-cells. Lysine deacetylase inhibitors (KDACi) protect beta-cells from inflammatory destruction in vitro and are promising immunomodulators. Here we demonstrate that the clinically well-tolerated KDACi vorinostat and givinostat revert diabetes

  14. Serum adipokines as biomarkers of beta-cell function in patients with type 1 diabetes

    DEFF Research Database (Denmark)

    Pham, Minh Nguyet; Kolb, Hubert; Mandrup-Poulsen, Thomas

    2013-01-01

    We investigated the adipokines adiponectin, leptin and resistin as serum biomarkers of beta-cell function in patients with type 1 diabetes.......We investigated the adipokines adiponectin, leptin and resistin as serum biomarkers of beta-cell function in patients with type 1 diabetes....

  15. Maternal obesity accelerates fetal pancreatic beta-cell but not alpha-cell development in sheep: prenatal consequences.

    Science.gov (United States)

    Ford, Stephen P; Zhang, Liren; Zhu, Meijun; Miller, Myrna M; Smith, Derek T; Hess, Bret W; Moss, Gary E; Nathanielsz, Peter W; Nijland, Mark J

    2009-09-01

    Maternal obesity affects offspring weight, body composition, and organ function, increasing diabetes and metabolic syndrome risk. We determined effects of maternal obesity and a high-energy diet on fetal pancreatic development. Sixty days prior to breeding, ewes were assigned to control [100% of National Research Council (NRC) recommendations] or obesogenic (OB; 150% NRC) diets. At 75 days gestation, OB ewes exhibited elevated insulin-to-glucose ratios at rest and during a glucose tolerance test, demonstrating insulin resistance compared with control ewes. In fetal studies, ewes ate their respective diets from 60 days before to 75 days after conception when animals were euthanized under general anesthesia. OB and control ewes increased in body weight by approximately 43% and approximately 6%, respectively, from diet initiation until necropsy. Although all organs were heavier in fetuses from OB ewes, only pancreatic weight increased as a percentage of fetal weight. Blood glucose, insulin, and cortisol were elevated in OB ewes and fetuses on day 75. Insulin-positive cells per unit pancreatic area were 50% greater in fetuses from OB ewes as a result of increased beta-cell mitoses rather than decreased programmed cell death. Lambs of OB ewes were born earlier but weighed the same as control lambs; however, their crown-to-rump length was reduced, and their fat mass was increased. We conclude that increased systemic insulin in fetuses from OB ewes results from increased glucose exposure and/or cortisol-induced accelerated fetal beta-cell maturation and may contribute to premature beta-cell function loss and predisposition to obesity and metabolic disease in offspring.

  16. Investigating remission and relapse in type 1 diabetes. Immune correlates of clinical outcome in beta-cell replacement therapies

    NARCIS (Netherlands)

    Torren, van der C.R.

    2017-01-01

    Type 1 Diabetes is caused by destruction of insulin producing beta-cells by autoimmune T-cells. Replacement of beta-cells through transplantation can supply new beta-cells, however these are at renewed peril of destruction through auto- and alloreactive immune responses. In this thesis, immune

  17. Maternal diabetes, programming of beta-cell disorders and intergenerational risk of type 2 diabetes.

    Science.gov (United States)

    Chavey, A; Ah Kioon, M-D; Bailbé, D; Movassat, J; Portha, B

    2014-11-01

    A substantial body of evidence suggests that an abnormal intra-uterine milieu elicited by maternal metabolic disturbances as diverse as malnutrition, placental insufficiency, diabetes and obesity may be able to programme susceptibility of the foetus to later develop chronic degenerative diseases such as obesity, hypertension, cardiovascular diseases and type 2 diabetes (T2D). As insulin-producing cells have been placed centre stage in the development of T2D, this review examines developmental programming of the beta-cell mass (BCM) in various rodent models of maternal protein restriction, calorie restriction, overnutrition and diabetes. The main message is that whatever the initial maternal insult (F0 generation) and whether alone or in combination, it gives rise to the same programmed BCM outcome in the daughter generation (F1). The altered BCM phenotype in F1 females prohibits normal BCM adaptation during pregnancy and, thus, diabetes (gestational diabetes) ensues. This gestational diabetes is then passed from one generation (F1) to the next (F2, F3 and so on). This review highlights a number of studies that have identified epigenetic mechanisms that may contribute to altered BCM development and beta-cell failure, as observed in diabetes. In addition to their role in instilling the programmed defect, these non-genomic mechanisms may also be involved in its intergenerational transmission. Copyright © 2014. Published by Elsevier Masson SAS.

  18. Search for $\\beta$-transitions with the lowest decay energy for a determination of the neutrino mass

    CERN Multimedia

    From a variety of $\\beta$-transitions only those with decay energies of a few keV and smaller are considered suitable for a determination of the neutrino mass on a sub-eV level. The decay energy of a transition can be very small, if, e.g., in an allowed $\\beta$-decay or electron-capture transition, a nuclear excited state of the daughter nuclide is populated whose energy is very close to the mass difference of the transition nuclides. Investigation of these transitions can also be useful for the assessment of a validity of the current $\\beta$-decay theory in the region of vanishingly small decay energies. The authors of this proposal have found several such $\\beta$-transitions whose decay energies are expected to be extremely small. In order to assess the suitability of these $\\beta$-transitions for the determination of the neutrino mass, measurements of the mass differences of the transition nuclides must be carried out with a sub-keV uncertainty. Presently, only high-precision Penning-trap mass spectrometry...

  19. Genetic predisposition for beta cell fragility underlies type 1 and type 2 diabetes.

    Science.gov (United States)

    Dooley, James; Tian, Lei; Schonefeldt, Susann; Delghingaro-Augusto, Viviane; Garcia-Perez, Josselyn E; Pasciuto, Emanuela; Di Marino, Daniele; Carr, Edward J; Oskolkov, Nikolay; Lyssenko, Valeriya; Franckaert, Dean; Lagou, Vasiliki; Overbergh, Lut; Vandenbussche, Jonathan; Allemeersch, Joke; Chabot-Roy, Genevieve; Dahlstrom, Jane E; Laybutt, D Ross; Petrovsky, Nikolai; Socha, Luis; Gevaert, Kris; Jetten, Anton M; Lambrechts, Diether; Linterman, Michelle A; Goodnow, Chris C; Nolan, Christopher J; Lesage, Sylvie; Schlenner, Susan M; Liston, Adrian

    2016-05-01

    Type 1 (T1D) and type 2 (T2D) diabetes share pathophysiological characteristics, yet mechanistic links have remained elusive. T1D results from autoimmune destruction of pancreatic beta cells, whereas beta cell failure in T2D is delayed and progressive. Here we find a new genetic component of diabetes susceptibility in T1D non-obese diabetic (NOD) mice, identifying immune-independent beta cell fragility. Genetic variation in Xrcc4 and Glis3 alters the response of NOD beta cells to unfolded protein stress, enhancing the apoptotic and senescent fates. The same transcriptional relationships were observed in human islets, demonstrating the role of beta cell fragility in genetic predisposition to diabetes.

  20. Constraints on the Active and Sterile Neutrino Masses from Beta-Ray Spectra: Past, Present and Future

    Czech Academy of Sciences Publication Activity Database

    Dragoun, Otokar; Vénos, Drahoslav

    2016-01-01

    Roč. 3, č. 1 (2016), s. 73-113 ISSN 1874-8430 R&D Projects: GA ČR(CZ) GAP203/12/1896 Institutional support: RVO:61389005 Keywords : active neutrino * Beta-ray spectrum * Beta- spectrometer * neutrino * neutrino mass * sterile neutrino Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders http://benthamopen.com/ABSTRACT/PHY-3-73

  1. Effect of beta-escin sodium on endothelial cells proliferation, migration and apoptosis.

    Science.gov (United States)

    Wang, Xu-Hua; Xu, Bo; Liu, Jing-Tao; Cui, Jing-Rong

    2008-01-01

    beta-Escin, the major active compound in extracts of the horse chestnut Aesculus hippocastanum seed, has shown clinically significant activity in chronic venous insufficiency (CVI). Our previous studies had shown that beta-escin sodium inhibited angiogenesis in chick chorioallantoic membrane (CAM) and in aortic disk assay. In this study, we explored the direct effect of beta-escin sodium on proliferation, migration and apoptosis in human umbilical vein endothelial cells (HUVECs) and ECV304 cells. Sulforhodamine B (SRB) assay showed that beta-escin sodium (10, 20, 40 microg/ml) inhibited endothelial cells (ECs) proliferation dose-dependently. beta-escin sodium also induced ECs apoptosis at 40 microg/ml. Cell migration was evaluated by an improved wound assay: barren spot assay. And the direct effect on cell motility excluding influence of cell proliferation was examined by High Content Screening (HCS, Cellomics) assay. The data indicated that beta-escin sodium suppressed ECs migration and cell motility. Western blot results suggested that beta-escin sodium acts on ECs possibly by increasing expression of thrombospondin-1 (TSP-1), and decreasing expression of PKC-alpha and activation of p44/42 mitogen-activated protein kinase (ERK) and p38 mitogen-activated protein kinase (p38 MAPK). Our findings give the evidence that beta-escin sodium might have potential anti-angiogenic activity via its direct effects on ECs.

  2. Beta-glucanase productivity improvement via cell immobilization of recombinant Escherichia coli cells in different matrices.

    Science.gov (United States)

    Beshay, Usama; El-Enshasy, Hesham; Ismail, I M K; Moawad, Hassan; Abd-El-Ghany, Sawsan

    2011-01-01

    The studies have been performed to analyze the production of beta-glucanase by a recombinant strain of Escherichia coli immobilized in different matrices. Porous sintered glass SIRAN, Ceramic supporting matrices and Broken Pumice stone as well as SIRAN Raschig-rings were examined for the immobilization of whole bacterial cells. The beta-glucanase activity of bacteria immobilized in CeramTec PST 5 (4-5 mm) was very low. CeramTec PST 5 (1.5-2.5 mm) was found to be the best carrier compared to all other matrices regarding glucanase production (630 U/ml) and compared to enzyme activity produced by free cells (500 U/ml). Different doses of matrices were applied (2, 5, 7, 10 g/lask) in the form of "matrix weight". Using 2 g/flask of CeramTec PST 5 (1.5-2.5 mm) yielded enzyme activity of 630 U/ml). CeramTec gives highest operational stability of beta-glucanase by repeated batch fermentation to 5 cycles, and activity reached 660 U/ml. Scanning electron microscopy observations showed a high number of vegetative cells that continued growth inside the matrices, indicating that beta-glucanase activity improvement was due to the immobilization of the cells.

  3. Enteroviruses, pancreatic beta-cells, and dendritic cells: a dangerous triangle in type 1 diabetes etiology?

    NARCIS (Netherlands)

    Schulte, B.M.

    2010-01-01

    Type 1 diabetes mellitus (T1D, insulin-dependent diabetes mellitus) is an endocrine autoimmune disorder in which the insulin-producing beta-cells in the pancreas are gradually destroyed. Enterovirus infections (in particular coxsackievirus and echovirus) have been implicated in the development of

  4. TGF-beta regulation of nuclear proto-oncogenes and TGF-beta gene expression in normal human osteoblast-like cells.

    Science.gov (United States)

    Subramaniam, M; Oursler, M J; Rasmussen, K; Riggs, B L; Spelsberg, T C

    1995-01-01

    Transforming growth factor-beta (TGF-beta) is present in high levels in bone and plays an important role in osteoblast growth and differentiation. In order to dissect the molecular mechanisms of action of TGF-beta on osteoblasts, the effects of TGF-beta on the steady state mRNA levels of c-fos, c-jun, and jun-B proto-oncogenes on normal human osteoblast-like cells (hOB) and a transformed human osteoblast cell line (MG-63) were measured. Treatment of hOBs with 2 ng/ml of TGF-beta 1 resulted in a rapid increase in c-fos mRNA levels as early as 15 min post-treatment. A maximum (10-fold) increase was observed at 30 min after TGF-beta treatment followed by a decrease to control values. Similar responses were measured whether the cells were rapidly proliferating or quiescent. TGF-beta 1 induced jun-B mRNA levels more gradually with steady increase initially observed at 30 min and a maximum induction measured at 2 h post-TGF-beta treatment. In contrast, TGF-beta treatment caused a time dependent decrease in the c-jun mRNA levels, an opposite pattern to that of jun-B mRNA. Treatment of hOBs with TGF-beta 1 in the presence of actinomycin-D abolished TGF-beta 1 induction of c-fos mRNA, suggesting that TGF-beta action is mediated via transcription. In the presence of cycloheximide, TGF-beta causes super-induction of c-fos mRNA at 30 min, indicating that the c-fos expression by TGF-beta is independent of new protein synthesis. Further, transfection of 3 kb upstream region of jun-B promoter linked to a CAT reporter gene into ROS 17/2.8 cells was sufficient to be regulated by TGF-beta 1. Interestingly, TGF-beta treatment also increased the mRNA levels of TGF-beta 1 itself at 4 h post TGF-beta treatment, with a maximum increase observed at 14 h of treatment. TGF-beta 1 treatment for 30 min were sufficient to cause a delayed increase in TGF-beta protein secretion within 24 h. These data support that TGF-beta has major effects on hOB cell proto-oncogene expression and that the

  5. Nuclear orphan receptor TLX affects gene expression, proliferation and cell apoptosis in beta cells.

    Science.gov (United States)

    Shi, Xiaoli; Xiong, Xiaokan; Dai, Zhe; Deng, Haohua; Sun, Li; Hu, Xuemei; Zhou, Feng; Xu, Yancheng

    Nuclear orphan receptor TLX is an essential regulator of the growth of neural stem cells. However, its exact function in pancreatic islet cells is still unknown. In the present study, gene expression profiling analysis revealed that overexpression of TLX in beta cell line MIN6 causes suppression of 176 genes and upregulation of 49 genes, including a cadre of cell cycle, cell proliferation and cell death control genes, such as Btg2, Ddit3 and Gadd45a. We next examined the effects of TLX overexpression on proliferation, apoptosis and insulin secretion in MIN6 cells. Proliferation analysis using EdU assay showed that overexpression of TLX increased percentage of EdU-positive cells. Cell cycle and apoptosis analysis revealed that overexpression of TLX in MIN6 cells resulted in higher percentage of cells exiting G1 into S-phase, and a 58.8% decrease of cell apoptosis induced by 0.5 mM palmitate. Moreover, TLX overexpression did not cause impairment of insulin secretion. Together, we conclude that TLX is among factors capable of controlling beta cell proliferation and survival, which may serve as a target for the development of novel therapies for diabetes. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Uptake of neutral alpha- and beta-amino acids by human proximal tubular cells

    DEFF Research Database (Denmark)

    Jessen, H; Røigaard, H; Jacobsen, Christian

    1996-01-01

    experiments revealed that all the neutral amino acids tested reduced the uptake of AIB, whereas there was no effect of taurine, L-aspartic acid, and L-arginine. By contrast, the influx of beta-alanine was only drastically reduced by beta-amino acids, whereas the inhibition by neutral alpha-amino acids...... was relatively low. Nor did L-arginine and L-aspartic acid affect the uptake of beta-alanine into AHKE cells. Comparison with the results obtained for normal (NHKE) and immortalized (IHKE) embryonic cells suggested an unaltered expression of the types of transport carriers for neutral alpha- and beta-amino acids...

  7. Skin deep: from dermal fibroblasts to pancreatic beta cells.

    Science.gov (United States)

    Manzar, Gohar S; Kim, Eun-Mi; Rotti, Pavana; Zavazava, Nicholas

    2014-08-01

    Type I diabetes (T1D) is a chronic autoimmune disease caused by pancreatic β-cell destruction induced by autoantibodies and autoreactive T cells. After significant reduction of the β-cell mass, diabetes sets in and can cause significant complications. It is estimated that more than 3 million Americans have T1D, and its prevalence among young individuals is progressively rising; however, the reasons for this increase are not known. Islet transplantation is recognized as the ultimate cure for T1D, but unfortunately, the severe scarcity of available islets makes it necessary to establish alternative sources of β-cells. Our lab seeks to establish human-induced pluripotent stem cells as an unlimited, novel source of insulin-producing cells (IPCs) that are patient-specific, obviating the requirement for immunosuppression. Although several reports have emerged demonstrating successful derivation of IPCs from human pluripotent stem cells, the efficiencies of derivation are inadequate and these IPCs do not respond to glucose stimulation in vitro. We reasoned that the use of a growth factor sequestering bioscaffold and promotion of cell-cell signaling through 3D clustering would enhance the generation of functionally superior IPCs compared to those derived by 2D differentiation. Here, we discuss a novel 3D platform for the generation of highly efficient human IPCs.

  8. Mesenchymal stem cells maintain TGF-beta-mediated chondrogenic phenotype in alginate bead culture

    DEFF Research Database (Denmark)

    Mehlhorn, A T; Schmal, H; Kaiser, S

    2006-01-01

    of any chondrogenic growth factor or in the presence of osteogenic signals. MSCs encapsulated in alginate beads were treated with transforming growth factor (TGF)-beta 3 for 3, 6, or 14 days and then cultured in absence of TGF-beta for the remainder of the 2-week culture period. Additionally, cells were...... cultured in osteogenic medium after TGF-beta-mediated chondroinduction. Gene expression of col2a1, aggrecan, COMP, alkaline phosphatase (AP), and correlating protein synthesis was analyzed. After short-term stimulation with TGF-beta, MSCs maintained a chondrogenic phenotype. Chondrogenic gene expression...... and protein synthesis directly correlated with the extent of stimulation time and the concentration of TGF-beta. Pretreatment with TGF-beta could prevent AP mRNA expression of encapsulated MSCs. TGF- beta stimulation within the first 3 days of culture seems to be crucial for the expression of a chondrogenic...

  9. Expression profiling of genes regulated by TGF-beta: Differential regulation in normal and tumour cells

    Directory of Open Access Journals (Sweden)

    Takahashi Takashi

    2007-04-01

    Full Text Available Abstract Background TGF-beta is one of the key cytokines implicated in various disease processes including cancer. TGF-beta inhibits growth and promotes apoptosis in normal epithelial cells and in contrast, acts as a pro-tumour cytokine by promoting tumour angiogenesis, immune-escape and metastasis. It is not clear if various actions of TGF-beta on normal and tumour cells are due to differential gene regulations. Hence we studied the regulation of gene expression by TGF-beta in normal and cancer cells. Results Using human 19 K cDNA microarrays, we show that 1757 genes are exclusively regulated by TGF-beta in A549 cells in contrast to 733 genes exclusively regulated in HPL1D cells. In addition, 267 genes are commonly regulated in both the cell-lines. Semi-quantitative and real-time qRT-PCR analysis of some genes agrees with the microarray data. In order to identify the signalling pathways that influence TGF-beta mediated gene regulation, we used specific inhibitors of p38 MAP kinase, ERK kinase, JNK kinase and integrin signalling pathways. The data suggest that regulation of majority of the selected genes is dependent on at least one of these pathways and this dependence is cell-type specific. Interestingly, an integrin pathway inhibitor, RGD peptide, significantly affected TGF-beta regulation of Thrombospondin 1 in A549 cells. Conclusion These data suggest major differences with respect to TGF-beta mediated gene regulation in normal and transformed cells and significant role of non-canonical TGF-beta pathways in the regulation of many genes by TGF-beta.

  10. Expression and autoregulation of transforming growth factor beta receptor mRNA in small-cell lung cancer cell lines

    DEFF Research Database (Denmark)

    Nørgaard, P; Spang-Thomsen, M; Poulsen, H S

    1996-01-01

    and beta-glycan (RIII) was examined. The results showed that loss of RII mRNA correlated with TGF-beta 1 resistance. In contrast, RI-and beta-glycan mRNA was expressed by all cell lines, including those lacking expression of these proteins. According to Southern blot analysis, the loss of type II m......RNA was not due to gross structural changes in the gene. The effect of TGF-beta 1 on expression of TGF-beta receptor mRNA (receptor autoregulation) was examined by quantitative Northern blotting in four cell lines with different expression of TGF-beta receptor proteins. In two cell lines expressing all three TGF...

  11. Beta1 integrins differentially control extravasation of inflammatory cell subsets into the CNS during autoimmunity

    DEFF Research Database (Denmark)

    Bauer, Martina; Brakebusch, Cord; Coisne, Caroline

    2009-01-01

    Inhibiting the alpha(4) subunit of the integrin heterodimers alpha(4)beta(1) and alpha(4)beta(7) with the monoclonal antibody natalizumab is an effective treatment for multiple sclerosis (MS). However, the pharmacological action of natalizumab is not understood conclusively. Previous studies...... to firmly adhere to CNS endothelium in vivo, whereas their priming and expansion remain unaffected. Collectively, these results suggest that the primary action of natalizumab is interference with T cell extravasation via inhibition of alpha(4)beta(1) integrins....

  12. Regulation of the susceptibility to oxidative stress by cysteine availability in pancreatic beta-cells.

    Science.gov (United States)

    Numazawa, Satoshi; Sakaguchi, Harumi; Aoki, Risa; Taira, Toshio; Yoshida, Takemi

    2008-08-01

    Pancreatic beta-cells are susceptible to oxidative stress, which is related closely to the islet dysfunction. In the present study, using the pancreatic cell lines HIT-T15 and RINm5F as known in vitro models of impaired beta-cell function as well as primary rat islet beta-cells, we observed a relationship between intracellular glutathione levels and oxidative stress-mediated cell dysfunction. Hydrogen peroxide and 4-hydroxy-2-nonenal caused cell death in HIT-T15 and RINm5F cells at lower concentrations compared with non-beta-cells, such as HepG2 and NRK-49F cells. The extent of the cytotoxicity caused by the model oxidants was inversely correlated well with intracellular glutathione levels in the cell lines used. Treatment of HIT-T15 and RINm5F cells with l-cysteine or l-cystine significantly augmented the glutathione contents, surpassing the effect of N-acetylcysteine, and abrogated 4-hydroxy-2-nonenal-mediated cytotoxicity almost completely. l-Cysteine increased intracellular glutathione levels in primary beta-cells as well. Supplementation of l-cysteine to the RINm5F cell culture inhibited 4-hydroxy-2-nonenal-mediated cytosolic translocation of PDX-1, a key transcription factor for beta-cell function. Intrinsic transport activities (V(max)/K(m)) of the l-cystine/l-glutamate exchanger in HIT-T15 and RINm5F cells were considerably lower than that in NRK-49F cells, although gene expressions of the exchanger were similar in these cells. Results obtained from the present study suggest that the restricted activity of the l-cystine/l-glutamate exchanger controls the levels of intracellular glutathione, thereby making beta-cells become susceptible to oxidative stress.

  13. Endothelial and beta cell composite aggregates for improved function of a bioartificial pancreas encapsulation device.

    Science.gov (United States)

    Skrzypek, Katarzyna; Barrera, Yazmin Brito; Groth, Thomas; Stamatialis, Dimitrios

    2018-03-01

    Encapsulation of pancreatic islets or beta cells is a promising strategy for treatment of type 1 diabetes by providing an immune isolated environment and allowing for transplantation in a different location than the liver. However, islets used for encapsulation often show lower functionality due to the damaging of islet endothelial cells during the isolation procedure. Factors produced by endothelial cells have great impact on beta cell insulin secretion. Therefore, mutual signaling between endothelial cells and beta cells should be considered for the development of encapsulation systems to achieve high insulin secretion and maintain beta cell viability. Here, we investigate whether co-culture of beta cells with endothelial cells could improve beta cell function within encapsulation devices. Mouse insulinoma MIN6 cells and human umbilical vein endothelial cells were used for creating composite aggregates on agarose microwell platform. The composite aggregates were encapsulated within flat poly(ether sulfone)/polyvinylpyrrolidone device. Their functionality was assessed by glucose-induced insulin secretion test and compared to non-encapsulated free-floating aggregates. We created composite aggregates of 80-100 µm in diameter, closely mimicking pancreatic islets. Upon glucose stimulation, their insulin secretion is improved in comparison to aggregates consisting of only MIN6 cells. Moreover, the composite aggregates encapsulated within a device secrete more insulin than aggregates consisting of only MIN6 cells. Composite aggregates of MIN6 cells with human umbilical vein endothelial cells have improved insulin secretion in comparison to MIN6 aggregates showing that the interaction of beta cell and endothelial cell is crucial for a functional encapsulation system.

  14. Occurrence of thymosin beta4 in human breast cancer cells and in other cell types of the tumor microenvironment

    DEFF Research Database (Denmark)

    Larsson, L.-I.; Holck, Susanne

    2007-01-01

    that there is a considerable heterogeneity in the cellular distribution of thymosin beta4 in breast cancer. In most tumors examined, cancer cells showed low or intermediate reactivity for thymosin beta4, whereas leukocytes and macrophages showed intense reactivity. In addition, endothelial cells showed variable reactivity...... to thymosin beta4, whereas myofibroblasts were negative. There was no correlation between the intensity of tumor cell staining and histological grade, whereas there was a tendency toward a correlation between endothelial cell staining and grade. These results demonstrate that multiple cell types within...

  15. The Role of Helicobacter pylori Seropositivity in Insulin Sensitivity, Beta Cell Function, and Abnormal Glucose Tolerance

    Directory of Open Access Journals (Sweden)

    Lou Rose Malamug

    2014-01-01

    Full Text Available Infection, for example, Helicobacter pylori (H. pylori, has been thought to play a role in the pathogenesis of type 2 diabetes mellitus (T2DM. Our aim was to determine the role of H. pylori infection in glucose metabolism in an American cohort. We examined data from 4,136 non-Hispanic white (NHW, non-Hispanic black (NHB, and Mexican Americans (MA aged 18 and over from the NHANES 1999-2000 cohort. We calculated the odds ratios for states of glucose tolerance based on the H. pylori status. We calculated and compared homeostatic model assessment insulin resistance (HOMA-IR and beta cell function (HOMA-B in subjects without diabetes based on the H. pylori status. The results were adjusted for age, body mass index (BMI, poverty index, education, alcohol consumption, tobacco use, and physical activity. The H. pylori status was not a risk factor for abnormal glucose tolerance. After adjustment for age and BMI and also adjustment for all covariates, no difference was found in either HOMA-IR or HOMA-B in all ethnic and gender groups except for a marginally significant difference in HOMA-IR in NHB females. H. pylori infection was not a risk factor for abnormal glucose tolerance, nor plays a major role in insulin resistance or beta cell dysfunction.

  16. Co-culture of neural crest stem cells (NCSC and insulin producing beta-TC6 cells results in cadherin junctions and protection against cytokine-induced beta-cell death.

    Directory of Open Access Journals (Sweden)

    Anongnad Ngamjariyawat

    Full Text Available PURPOSE: Transplantation of pancreatic islets to Type 1 diabetes patients is hampered by inflammatory reactions at the transplantation site leading to dysfunction and death of insulin producing beta-cells. Recently we have shown that co-transplantation of neural crest stem cells (NCSCs together with the islet cells improves transplantation outcome. The aim of the present investigation was to describe in vitro interactions between NCSCs and insulin producing beta-TC6 cells that may mediate protection against cytokine-induced beta-cell death. PROCEDURES: Beta-TC6 and NCSC cells were cultured either alone or together, and either with or without cell culture inserts. The cultures were then exposed to the pro-inflammatory cytokines IL-1β and IFN-γ for 48 hours followed by analysis of cell death rates (flow cytometry, nitrite production (Griess reagent, protein localization (immunofluorescence and protein phosphorylation (flow cytometry. RESULTS: We observed that beta-TC6 cells co-cultured with NCSCs were protected against cytokine-induced cell death, but not when separated by cell culture inserts. This occurred in parallel with (i augmented production of nitrite from beta-TC6 cells, indicating that increased cell survival allows a sustained production of nitric oxide; (ii NCSC-derived laminin production; (iii decreased phospho-FAK staining in beta-TC6 cell focal adhesions, and (iv decreased beta-TC6 cell phosphorylation of ERK(T202/Y204, FAK(Y397 and FAK(Y576. Furthermore, co-culture also resulted in cadherin and beta-catenin accumulations at the NCSC/beta-TC6 cell junctions. Finally, the gap junction inhibitor carbenoxolone did not affect cytokine-induced beta-cell death during co-culture with NCSCs. CONCLUSION: In summary, direct contacts, but not soluble factors, promote improved beta-TC6 viability when co-cultured with NCSCs. We hypothesize that cadherin junctions between NCSC and beta-TC6 cells promote powerful signals that maintain beta-cell

  17. Occurrence of thymosin beta4 in human breast cancer cells and in other cell types of the tumor microenvironment

    DEFF Research Database (Denmark)

    Larsson, L.-I.; Holck, Susanne

    2007-01-01

    Previous studies have shown that the G-actin sequestering polypeptide thymosin beta4 frequently is overexpressed in cancers and that such overexpression correlates to malignant progression. However, the localization of thymosin beta4 in human cancers has not been determined. We now demonstrate...... that there is a considerable heterogeneity in the cellular distribution of thymosin beta4 in breast cancer. In most tumors examined, cancer cells showed low or intermediate reactivity for thymosin beta4, whereas leukocytes and macrophages showed intense reactivity. In addition, endothelial cells showed variable reactivity...... to thymosin beta4, whereas myofibroblasts were negative. There was no correlation between the intensity of tumor cell staining and histological grade, whereas there was a tendency toward a correlation between endothelial cell staining and grade. These results demonstrate that multiple cell types within...

  18. Beta1 integrin-mediated adhesion signalling is essential for epidermal progenitor cell expansion.

    Directory of Open Access Journals (Sweden)

    Aleksandra Piwko-Czuchra

    Full Text Available BACKGROUND: There is a major discrepancy between the in vitro and in vivo results regarding the role of beta1 integrins in the maintenance of epidermal stem/progenitor cells. Studies of mice with skin-specific ablation of beta1 integrins suggested that epidermis can form and be maintained in their absence, while in vitro data have shown a fundamental role for these adhesion receptors in stem/progenitor cell expansion and differentiation. METHODOLOGY/PRINCIPAL FINDINGS: To elucidate this discrepancy we generated hypomorphic mice expressing reduced beta1 integrin levels on keratinocytes that developed similar, but less severe defects than mice with beta1-deficient keratinocytes. Surprisingly we found that upon aging these abnormalities attenuated due to a rapid expansion of cells, which escaped or compensated for the down-regulation of beta1 integrin expression. A similar phenomenon was observed in aged mice with a complete, skin-specific ablation of the beta1 integrin gene, where cells that escaped Cre-mediated recombination repopulated the mutant skin in a very short time period. The expansion of beta1 integrin expressing keratinocytes was even further accelerated in situations of increased keratinocyte proliferation such as wound healing. CONCLUSIONS/SIGNIFICANCE: These data demonstrate that expression of beta1 integrins is critically important for the expansion of epidermal progenitor cells to maintain epidermal homeostasis.

  19. Osteocalcin protects pancreatic beta cell function and survival under high glucose conditions

    Energy Technology Data Exchange (ETDEWEB)

    Kover, Karen, E-mail: kkover@cmh.edu [Division of Endocrine/Diabetes, Children' s Mercy Hospital & Clinics, Kansas City, MO 64108 (United States); University of Missouri-Kansas City School of Medicine, Kansas City, MO 64108 (United States); Yan, Yun; Tong, Pei Ying; Watkins, Dara; Li, Xiaoyu [Division of Endocrine/Diabetes, Children' s Mercy Hospital & Clinics, Kansas City, MO 64108 (United States); University of Missouri-Kansas City School of Medicine, Kansas City, MO 64108 (United States); Tasch, James; Hager, Melissa [Kansas City University Medical Biosciences, Kansas City, MO (United States); Clements, Mark; Moore, Wayne V. [Division of Endocrine/Diabetes, Children' s Mercy Hospital & Clinics, Kansas City, MO 64108 (United States); University of Missouri-Kansas City School of Medicine, Kansas City, MO 64108 (United States)

    2015-06-19

    Diabetes is characterized by progressive beta cell dysfunction and loss due in part to oxidative stress that occurs from gluco/lipotoxicity. Treatments that directly protect beta cell function and survival in the diabetic milieu are of particular interest. A growing body of evidence suggests that osteocalcin, an abundant non-collagenous protein of bone, supports beta cell function and proliferation. Based on previous gene expression data by microarray, we hypothesized that osteocalcin protects beta cells from glucose-induced oxidative stress. To test our hypothesis we cultured isolated rat islets and INS-1E cells in the presence of normal, high, or high glucose ± osteocalcin for up to 72 h. Oxidative stress and viability/mitochondrial function were measured by H{sub 2}O{sub 2} assay and Alamar Blue assay, respectively. Caspase 3/7 activity was also measured as a marker of apoptosis. A functional test, glucose stimulated insulin release, was conducted and expression of genes/protein was measured by qRT-PCR/western blot/ELISA. Osteocalcin treatment significantly reduced high glucose-induced H{sub 2}O{sub 2} levels while maintaining viability/mitochondrial function. Osteocalcin also significantly improved glucose stimulated insulin secretion and insulin content in rat islets after 48 h of high glucose exposure compared to untreated islets. As expected sustained high glucose down-regulated gene/protein expression of INS1 and BCL2 while increasing TXNIP expression. Interestingly, osteocalcin treatment reversed the effects of high glucose on gene/protein expression. We conclude that osteocalcin can protect beta cells from the negative effects of glucose-induced oxidative stress, in part, by reducing TXNIP expression, thereby preserving beta cell function and survival. - Highlights: • Osteocalcin reduces glucose-induced oxidative stress in beta cells. • Osteocalcin preserves beta cell function and survival under stress conditions. • Osteocalcin reduces glucose

  20. The roles of ATF3, an adaptive-response gene, in high-fat-diet-induced diabetes and pancreatic beta-cell dysfunction.

    Science.gov (United States)

    Zmuda, Erik J; Qi, Ling; Zhu, Michael X; Mirmira, Raghavendra G; Montminy, Marc R; Hai, Tsonwin

    2010-07-01

    Most people with type 2 diabetes (T2D) have reduced beta-cell mass, and apoptosis is a key factor for this reduction. Previously, we showed that ATF3, an adaptive-response gene, is induced by various stress signals relevant to T2D, such as high glucose and high fatty acid. Because ATF3 is proapoptotic in beta-cells, we tested the hypothesis that ATF3 plays a detrimental role and contributes to the development of T2D. We compared wild-type (WT) and ATF3 knockout (KO) mice in an animal model for T2D, high-fat diet-induced diabetes. We also used INS-1 beta-cells and primary islets to analyze the roles of ATF3 in beta-cell function, including insulin gene expression and glucose-induced insulin secretion. Surprisingly, WT mice performed better in glucose tolerance test than KO mice, suggesting a protective, rather than detrimental, role of ATF3. At 12 wk on high-fat diet, no beta-cell apoptosis was observed, and the WT and KO mice had comparable beta-cell areas. However, ATF3 deficiency significantly reduced serum insulin levels in the KO mice without affecting insulin sensitivity, suggesting reduced beta-cell function in the KO mice. Analyses using INS-1 cells and primary islets support the notion that this defect is due, at least partly, to reduced insulin gene transcription in the KO islets without detectable reduction in glucose-induced calcium influx, a critical step for insulin secretion. In conclusion, our results support a model in which, before apoptosis becomes obvious, expression of ATF3 can be beneficial by helping beta-cells to cope with higher metabolic demand.

  1. 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...

  2. Modulation of phenotype of human prostatic stromal cells by transforming growth factor-betas.

    Science.gov (United States)

    Hisataki, Toshihiro; Itoh, Naoki; Suzuki, Kazuhiro; Takahashi, Atsushi; Masumori, Naoya; Tohse, Noritsugu; Ohmori, Yuki; Yamada, Shizuo; Tsukamoto, Taiji

    2004-02-01

    We investigated the effects of transforming growth factor (TGF)-betas on morphological and receptor phenotypes, as well as proliferation of four currently established human prostatic myofibroblast cell lines and one commercially available prostatic stromal cell line. The effects of TGF-betas on morphological changes and proliferation of the cells were studied by immunohistochemistry and bromodeoxyuridine assay, respectively. The expression of alpha 1-receptor subtypes was measured by real time quantitative reverse transcription-polymerase chain reaction (RT-PCR) and the radioligand binding assay for the receptors was also performed. TGF-betas 1, 2, and 3 induced expression of desmin and myosin of cells of the established cell lines, and significantly inhibited their growth. The alpha 1a-receptor was expressed only in the commercially available cell line and alpha 1b and 1d, in all cell lines. TGF-beta 1 suppressed the expression of all three subtypes of the alpha 1-receptor. The binding sites of cells of all the cell lines were reduced by treatment with this growth factor. TGF-betas may induce human prostatic stromal cells to express the smooth muscle phenotype and inhibited their growth. However, the growth factor reduced the binding sites of the receptor and suppressed mRNA expression of its subtypes, suggesting that morphological and receptor phenotypes may be regulated via more than one pathway by TGF-beta(s). Copyright 2003 Wiley-Liss, Inc.

  3. Glucagon-Like Peptide-1 Receptor Agonists: Beta-Cell Protection or Exhaustion?

    Science.gov (United States)

    van Raalte, Daniël H; Verchere, C Bruce

    2016-07-01

    Glucagon-like peptide (GLP)-1 receptor agonists enhance insulin secretion and may improve pancreatic islet cell function. However, GLP-1 receptor (GLP-1R) agonist treatment may have more complex, and sometimes deleterious, effects on beta cells. We discuss the concepts of beta cell protection versus exhaustion for different GLP-1R agonists based on recent data. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Effect of prolonged exposure to sublethal concentrations of DDT and DDE on protein expression in human pancreatic beta cells.

    Science.gov (United States)

    Pavlikova, Nela; Smetana, Pavel; Halada, Petr; Kovar, Jan

    2015-10-01

    Pollution of the environment represents one of less explored potential reasons for the worldwide epidemic of type 2 diabetes. One of the most prevalent organochlorine pollutants remains the pesticide DDT and its degradation product DDE. Despite some epidemiologic correlations between levels of DDT and DDE in human organism and the prevalence of diabetes, there is almost no information about the exact targets of these compounds inside pancreatic beta cells. To detect functional areas of pancreatic beta cells that could be affected by exposure to DDT and DDE, we analyzed changes in protein expression in the NES2Y human pancreatic beta cell line exposed to three sublethal concentrations (0.1 μM, 1 μM, 10 μM) of DDT and DDE for 1 month. Protein separation and identification was achieved using high-resolution 2D-electrophoresis, computer analysis and mass spectrometry. With these techniques, four proteins were found downregulated after exposure to 10 μM DDT: three cytoskeletal proteins (cytokeratin 8, cytokeratin 18 and actin) and one protein involved in glycolysis (alpha-enolase). Two proteins were downregulated after exposure to 10 μM DDE: cytokeratin 18 and heterogenous nuclear ribonucleoprotein H1 (HNRH1). These changes correlate with previously described effects of other stress conditions (e.g. exposure to palmitate, hyperglycemia, imidazoline derivative, and cytokines) on protein expression in pancreatic beta cells. We conclude that cytoskeletal proteins and their processing, glucose metabolism, and mRNA processing may represent targets affected by exposure to conditions hostile to pancreatic beta cells, including exposure to DDT and DDE. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Chemokine receptor expression on B cells and effect of interferon-beta in multiple sclerosis

    DEFF Research Database (Denmark)

    Sørensen, Torben Lykke; Roed, Hanne; Sellebjerg, Finn

    2002-01-01

    We investigated the B-cell expression of chemokine receptors CXCR3, CXCR5 and CCR5 in the blood and cerebrospinal fluid (CSF) from patients in relapse of multiple sclerosis (MS) and in neurological controls. Chemokine receptor expression was also studied in interferon-beta-treated patients with r......, and chemokine receptor expression was not affected by interferon-beta treatment....

  6. Lysine deacetylases are produced in pancreatic beta cells and are differentially regulated by proinflammatory cytokines

    DEFF Research Database (Denmark)

    Lundh, M; Christensen, D P; Rasmussen, D N

    2010-01-01

    Cytokine-induced beta cell toxicity is abrogated by non-selective inhibitors of lysine deacetylases (KDACs). The KDAC family consists of 11 members, namely histone deacetylases HDAC1 to HDAC11, but it is not known which KDAC members play a role in cytokine-mediated beta cell death. The aim...... of the present study was to examine the KDAC gene expression profile of the beta cell and to investigate whether KDAC expression is regulated by cytokines. In addition, the protective effect of the non-selective KDAC inhibitor ITF2357 and interdependent regulation of four selected KDACs were investigated....

  7. Pancreatic beta-cell lipotoxicity induced by overexpression of hormone-sensitive lipase

    DEFF Research Database (Denmark)

    Winzell, Maria Sörhede; Svensson, Håkan; Enerbäck, Sven

    2003-01-01

    Lipid perturbations associated with triglyceride overstorage in beta-cells impair insulin secretion, a process termed lipotoxicity. To assess the role of hormone-sensitive lipase, which is expressed and enzymatically active in beta-cells, in the development of lipotoxicity, we generated transgenic...... mice overexpressing hormone-sensitive lipase specifically in beta-cells. Transgenic mice developed glucose intolerance and severely blunted glucose-stimulated insulin secretion when challenged with a high-fat diet. As expected, both lipase activity and forskolin-stimulated lipolysis was increased...

  8. Effects of TGF-betas and a specific antagonist on apoptosis of immature rat male germ cells in vitro.

    Science.gov (United States)

    Konrad, L; Keilani, M M; Laible, L; Nottelmann, U; Hofmann, R

    2006-05-01

    Massive apoptosis of pubertal male germ cells is important for the development of functional spermatogenesis in the adult testis. Although the trigger(s) for male germ cell loss at puberty remain undefined, we have hypothesized that transforming growth factor-betas (TGF-betas) play an active role. Here we demonstrate that the three mammalian TGF-beta isoforms, TGF-beta1, TGF-beta2 and TGF-beta3, induce distinct apoptosis of pubertal spermatogonia and spermatocytes in a dose-dependent manner. Induction of male germ cell death by activation of caspase-3 was most pronounced with TGF-beta2 compared to TGF-beta1 and TGF-beta3. Furthermore, we found colocalization of activated caspase-3 with apoptotic protease-activating factor-1 (Apaf-1) in apoptotic germ cells, thus indicating the importance of the intrinsic mitochondrial pathway in TGF-beta-induced apoptosis. The specificity of the TGF-beta effects was proven by addition of recombinant latency-associated peptide against TGF-beta1 (rLAP-TGF-beta1) which completely abolished TGF-beta1-induced and TGF-beta3-induced germ cell apoptosis. Although TGF-beta2-triggered germ cell death also was significantly reduced by rLAP-TGF-beta1, inhibition was not maximal. Our results suggest that the three TGF-beta isoforms induce apoptosis of pubertal male germ cells via the mitochondrial pathway in vitro and are thus likely candidates involved in the excessive first wave of apoptosis of male germ cells during puberty.

  9. The thermal stability of sodium beta'-Alumina solid electrolyte ceramic in AMTEC cells

    International Nuclear Information System (INIS)

    Williams, Roger M.; Ryan, Margaret A.; Homer, Margie L.; Lara, Liana; Manatt, Ken; Shields, Virgil; Cortez, Roger H.; Kulleck, James

    1999-01-01

    A critical component of alkali metal thermal-to electric converter (AMTEC) devices for long duration space missions is the beta'-alumina solid electrolyte ceramic (BASE), for which there exists no substitute. The temperature and environmental conditions under which BASE remains stable control operational parameters of AMTEC devices. We have used mass loss experiments in vacuum to 1573K to characterize the kinetics of BASE decomposition, and conductivity and exchange current measurements in sodium vapor filled exposure cells to 1223K to investigate changes in the BASE which affect its ionic conductivity. There is no clear evidence of direct thermal decomposition of BASE below 1273K, although limited soda loss may occur. Reactive metals such as Mn or Cr can react with BASE at temperatures at least as low as 1223K

  10. The ectopic expression of Pax4 in the mouse pancreas converts progenitor cells into alpha and subsequently beta cells

    DEFF Research Database (Denmark)

    Collombat, Patrick; Xu, Xiaobo; Ravassard, Philippe

    2009-01-01

    We have previously reported that the loss of Arx and/or Pax4 gene activity leads to a shift in the fate of the different endocrine cell subtypes in the mouse pancreas, without affecting the total endocrine cell numbers. Here, we conditionally and ectopically express Pax4 using different cell......-specific promoters and demonstrate that Pax4 forces endocrine precursor cells, as well as mature alpha cells, to adopt a beta cell destiny. This results in a glucagon deficiency that provokes a compensatory and continuous glucagon+ cell neogenesis requiring the re-expression of the proendocrine gene Ngn3. However......, the newly formed alpha cells fail to correct the hypoglucagonemia since they subsequently acquire a beta cell phenotype upon Pax4 ectopic expression. Notably, this cycle of neogenesis and redifferentiation caused by ectopic expression of Pax4 in alpha cells is capable of restoring a functional beta cell...

  11. Nuclear import of glucokinase in pancreatic beta-cells is mediated by a nuclear localization signal and modulated by SUMOylation.

    Science.gov (United States)

    Johansson, Bente Berg; Fjeld, Karianne; Solheim, Marie Holm; Shirakawa, Jun; Zhang, Enming; Keindl, Magdalena; Hu, Jiang; Lindqvist, Andreas; Døskeland, Anne; Mellgren, Gunnar; Flatmark, Torgeir; Njølstad, Pål Rasmus; Kulkarni, Rohit N; Wierup, Nils; Aukrust, Ingvild; Bjørkhaug, Lise

    2017-10-15

    The localization of glucokinase in pancreatic beta-cell nuclei is a controversial issue. Although previous reports suggest such a localization, the mechanism for its import has so far not been identified. Using immunofluorescence, subcellular fractionation and mass spectrometry, we present evidence in support of glucokinase localization in beta-cell nuclei of human and mouse pancreatic sections, as well as in human and mouse isolated islets, and murine MIN6 cells. We have identified a conserved, seven-residue nuclear localization signal ( 30 LKKVMRR 36 ) in the human enzyme. Substituting the residues KK 31,32 and RR 35,36 with AA led to a loss of its nuclear localization in transfected cells. Furthermore, our data indicates that SUMOylation of glucokinase modulates its nuclear import, while high glucose concentrations do not significantly alter the enzyme nuclear/cytosolic ratio. Thus, for the first time, we provide data in support of a nuclear import of glucokinase mediated by a redundant mechanism, involving a nuclear localization signal, and which is modulated by its SUMOylation. These findings add new knowledge to the functional role of glucokinase in the pancreatic beta-cell. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Expression and ligand binding of alpha 2 beta 1 integrin on breast carcinoma cells.

    Science.gov (United States)

    Maemura, M; Akiyama, S K; Woods, V L; Dickson, R B

    1995-07-01

    We examined the expression and ligand specificity of the alpha 2 beta 1 integrin on human mammary epithelial cells (HMEC) and a panel of breast carcinoma cell lines in vitro. We found that the alpha 2 beta 1 integrin was universally, but quite variably expressed on these cells by FACS analysis. No significant correlation was observed between its expression and other known cellular phenotypes. Substrate attachment assays using blocking antibodies demonstrated that alpha 2 beta 1 integrin served as a receptor for collagen on HMEC and almost all breast carcinoma cells. However, its contribution to laminin binding of these cells appeared to be related to cellular differentiation as evaluated by sex steroid receptor status and by markers of epithelial-mesenchymal transition, i.e. loss of E-cadherin and expression of vimentin. Two different populations of non-malignant immortalized HMEC (184A1N4 and MCF-10A) contained cells capable of using alpha 2 beta 1 integrin as a laminin receptor. Breast cancer cell lines positive for estrogen receptor (ER) and E-cadherin (MCF-7, T47D, ZR75-1) could also use alpha 2 beta 1 integrin as a laminin receptor. Conversely, alpha 2 beta 1 integrin appeared to be incapable of binding to laminin or to be a very minor receptor for laminin on metastatic ER-negative breast carcinoma cells that expressed vimentin (MDA-MB 231, MDA-MB 435, and MDA-MB 436). These findings suggest that the ligand specificity of alpha 2 beta 1 integrin, i.e. its function as a laminin receptor, may be regulated during the malignant progression of breast carcinoma cells. A reduced contribution of alpha 2 beta 1 integrin to the cellular laminin binding appears to be associated with an increased malignant phenotype and with an epithelial-mesenchymal transition of breast carcinoma cells.

  13. Expression and autoregulation of transforming growth factor beta receptor mRNA in small-cell lung cancer cell lines

    DEFF Research Database (Denmark)

    Nørgaard, P; Spang-Thomsen, M; Poulsen, H S

    1996-01-01

    In small-cell lung cancer cell lines resistance to growth inhibition by transforming growth factor (TGF)-beta 1, was previously shown to correlate with lack of TGF-beta receptor I (RI) and II (RII) proteins. To further investigate the role of these receptors, the expression of mRNA for RI, RII...... and beta-glycan (RIII) was examined. The results showed that loss of RII mRNA correlated with TGF-beta 1 resistance. In contrast, RI-and beta-glycan mRNA was expressed by all cell lines, including those lacking expression of these proteins. According to Southern blot analysis, the loss of type II m......RNA was not due to gross structural changes in the gene. The effect of TGF-beta 1 on expression of TGF-beta receptor mRNA (receptor autoregulation) was examined by quantitative Northern blotting in four cell lines with different expression of TGF-beta receptor proteins. In two cell lines expressing all three TGF...

  14. Osteoprotegerin mediates tumor-promoting effects of Interleukin-1beta in breast cancer cells.

    Science.gov (United States)

    Chung, Stephanie Tsang Mui; Geerts, Dirk; Roseman, Kim; Renaud, Ashleigh; Connelly, Linda

    2017-02-01

    It is widely recognized that inflammation promotes breast cancer invasion and metastasis. Given the complex nature of the breast tumor inflammatory microenvironment, much remains to be understood of the molecular mechanisms that govern these effects. We have previously shown that osteoprotegerin knockdown in breast cancer cells resulted in reduced invasion and metastasis. Here we present novel insight into the role of osteoprotegerin in inflammation-driven tumor progression in breast cancer by investigating the link between osteoprotegerin, macrophages and the potent pro-inflammatory cytokine Interleukin-1beta. We used human breast cancer cell lines to investigate the effects of Interleukin-1beta treatment on osteoprotegerin secretion as measured by ELISA. We analyzed public datasets containing human breast cancer genome-wide mRNA expression data to reveal a significant and positive correlation between osteoprotegerin mRNA expression and the mRNA expression of Interleukin-1beta and of monocyte chemoattractant protein CC-chemokine ligand 2. Osteoprotegerin, Interleukin-1beta and CC-chemokine ligand 2 mRNA levels were also examined by qPCR on cDNA from normal and cancerous human breast tissue. We determined the effect of Interleukin-1beta-producing macrophages on osteoprotegerin expression by co-culturing breast cancer cells and differentiated THP-1 macrophages. Immunohistochemistry was performed on human breast tumor tissue microarrays to assess macrophage infiltration and osteoprotegerin expression. To demonstrate that osteoprotegerin mediated functional effects of Interleukin-1beta we performed cell invasion studies with control and OPG siRNA knockdown on Interleukin-1beta-treated breast cancer cells. We report that Interleukin-1beta induces osteoprotegerin secretion, independent of breast cancer subtype and basal osteoprotegerin levels. Co-culture of breast cancer cells with Interleukin-1beta-secreting macrophages resulted in a similar increase in osteoprotegerin

  15. Study of beta-cell function (by HOMA model) in metabolic syndrome.

    Science.gov (United States)

    Garg, M K; Dutta, M K; Mahalle, Namita

    2011-07-01

    The clustering of cardiovascular risk factors is termed the metabolic syndrome (MS), which strongly predict risk of diabetes and cardiovascular disease. Many studies implicate insulin resistance (IR) in the development of diabetes, but ignore the contribution of beta-cell dysfunction. Hence, we studied beta-cell function, as assessed by HOMA model, in subjects with MS. We studied 50 subjects with MS diagnosed by IDF criteria and 24 healthy age- and sex-matched controls. Clinical evaluation included anthropometry, body fat analysis by bioimpedance, biochemical, and insulin measurement. IR and secretion were calculated by HOMA model. Subjects with MS had more IR (HOMA-IR) than controls (3.35 ± 3.14 vs. 1.76 ± 0.53, P = 0.029) and secreted less insulin (HOMA-S) than controls (66.80 ± 69.66 vs. 144.27 ± 101.61, P = 0.0003), although plasma insulin levels were comparable in both groups (10.7 ± 10.2 vs. 8.2 ± 2.38, P = 0.44). HOMA-IR and HOMA-S were related with number of metabolic abnormalities. HOMA-IR was positively associated with body mass index, waist hip ratio, body fat mass, and percent body fat. HOMA-S was negatively associated with waist hip ratio, fasting plasma glucose and total cholesterol and positively with basal metabolic rate. Percent body fat was an independent predictor of HOMA-IR and waist hip ratio of HOMA-S in multiple regression analysis. Subjects with MS have increased IR and decreased insulin secretion compared with healthy controls. Lifestyle measures have been shown to improve IR, insulin secretion, and various components and effects of MS. Hence, there is an urgent need for public health measures to prevent ongoing epidemic of diabetes and cardiovascular disease.

  16. Targeted transgenic expression of beta(2)-adrenergic receptors to type II cells increases alveolar fluid clearance.

    Science.gov (United States)

    McGraw, D W; Fukuda, N; James, P F; Forbes, S L; Woo, A L; Lingrel, J B; Witte, D P; Matthay, M A; Liggett, S B

    2001-10-01

    Clearance of edema fluid from the alveolar space can be enhanced by endogenous and exogenous beta-agonists. To selectively delineate the effects of alveolar type II (ATII) cell beta(2)-adrenergic receptors (beta(2)-ARs) on alveolar fluid clearance (AFC), we generated transgenic (TG) mice that overexpressed the human beta(2)-AR under control of the rat surfactant protein C promoter. In situ hybridization showed that transgene expression was consistent with the distribution of ATII cells. TG mice expressed 4.8-fold greater beta(2)-ARs than nontransgenic (NTG) mice (939 +/- 113 vs. 194 +/- 18 fmol/mg protein; P < 0.001). Basal AFC in TG mice was approximately 40% greater than that in untreated NTG mice (15 +/- 1.4 vs. 10.9 +/- 0.6%; P < 0.005) and approached that of NTG mice treated with the beta-agonist formoterol (19.8 +/- 2.2%; P = not significant). Adrenalectomy decreased basal AFC in TG mice to 9.7 +/- 0.5% but had no effect on NTG mice (11.5 +/- 1.0%). Na(+)-K(+)-ATPase alpha(1)-isoform expression was unchanged, whereas alpha(2)-isoform expression was approximately 80% greater in the TG mice. These findings show that beta(2)-AR overexpression can be an effective means to increase AFC in the absence of exogenous agonists and that AFC can be stimulated by activation of beta(2)-ARs specifically expressed on ATII cells.

  17. Expression of integrin beta 6 enhances invasive behavior in oral squamous cell carcinoma.

    Science.gov (United States)

    Ramos, Daniel M; But, Maria; Regezi, Joseph; Schmidt, Brian L; Atakilit, Amha; Dang, Dongmin; Ellis, Duncan; Jordan, Richard; Li, Xiaowu

    2002-04-01

    Oral squamous cell carcinoma (SCC) is characterized by invasive growth and the propensity for distant metastasis. The expression of specific adhesion receptors promotes defined interactions with the specific components found within the extracellular matrix (ECM). We previously showed that the alpha v beta 6 fibronectin receptor is highly expressed in oral SCC. Here we forced expression of the beta 6 subunit into poorly invasive SCC9 cells to establish the SCC9 beta 6 cell line and compared these two cell lines in several independent assays. Whereas adhesion to fibronectin was unaffected by the expression of beta 6, migration on fibronectin and invasion through a reconstituted basement membrane (RBM) were both increased. Function-blocking antibodies to alpha v beta 6 (10D5) reduced both migration on fibronectin and invasion through an RBM, whereas anti-alpha 5 antibodies were effective only in suppressing migration on fibronectin, not invasion. Expression of beta 6 also promoted tumor growth and invasion in vivo and modulated fibronectin matrix deposition. When grown as a co-culture with SCC9 cells, peritumor fibroblasts (PTF) organized a dense fibronectin matrix. However, fibronectin matrix assembly was decreased in co-cultures of SCC9 beta 6 cells and PTF and this decrease was reversed by the addition of function-blocking anti-alpha v beta 6 antibodies. The expression of beta 6 also resulted in increased levels of matrix metalloproteinase 3. Addition of the general MMP inhibitor GM6001 to SCC9 beta 6/PTF co-cultures dramatically increased fibronectin matrix assembly in a similar fashion as incubation with anti-alpha v beta 6 antibodies. These results demonstrate that expression of beta 6 (1) increases oral SCC cell motility and growth in vitro and in vivo; (2) negatively affects fibronectin matrix assembly; and (3) stimulates the expression and activation of MMP3. We suggest that the integrin alpha v beta 6 is a key component of oral SCC invasion and metastasis

  18. Beta-endorphin Cell Therapy for Cancer Prevention

    OpenAIRE

    Zhang, Changqing; Murugan, Sengottuvelan; Boyadjieva, Nadka; Jabbar, Shaima; Shrivastava, Pallavi; Sarkar, Dipak K.

    2014-01-01

    Beta-endorphin (BEP) producing neuron in the hypothalamus plays a key role in brining the stress axis to a state of homeostasis and maintaining body immune defense system. Long-term delivery of BEP to obtain beneficial effect on chemoprevention is challenging, since the peptide rapidly develop tolerance. Using rats as animal model, we show here that transplantation of beta-endorphin neurons into the hypothalamus suppressed carcinogens- and hormone-induced cancers in various tissues and preven...

  19. Massive parallel gene expression profiling of RINm5F pancreatic islet beta-cells stimulated with interleukin-1beta

    DEFF Research Database (Denmark)

    Rieneck, K; Bovin, L F; Josefsen, K

    2000-01-01

    Interleukin 1 (IL-1) is a pleiotropic cytokine with the potential to kill pancreatic beta-cells, and this unique property is thought to be involved in the pathogenesis of type I diabetes mellitus. We therefore determined the quantitative expression of 24,000 mRNAs of RINm5F, an insulinoma cell li......, e.g. alpha-endosulfine and K+ channel Kir6.2 are differentially regulated. A number of transcripts in the biosynthesis pathway for cholesterol are also differentially regulated....

  20. The effects of glucagon-like peptide-1 on the beta cell

    DEFF Research Database (Denmark)

    Vilsbøll, Tina

    2009-01-01

    Type 2 diabetes is a progressive disease characterized by insulin resistance and impaired beta-cell function. Treatments that prevent further beta-cell decline are therefore essential for the management of type 2 diabetes. Glucagon-like peptide-1 (GLP-1) is an incretin hormone that is known...... to stimulate glucose-dependent insulin secretion. Furthermore, GLP-1 appears to have multiple positive effects on beta cells. However, GLP-1 is rapidly degraded by dipeptidyl peptidase-4 (DPP-4), which limits the clinical relevance of GLP-1 for the treatment of type 2 diabetes. Two main classes of GLP-1-based...... with type 2 diabetes, as assessed by homoeostasis model assessment-B analysis and proinsulin : insulin ratio. Additionally, liraglutide and exenatide are able to enhance first- and second-phase insulin secretion and are able to restore beta-cell sensitivity to glucose. Preclinical studies have shown...

  1. Effect of aerobic exercise on Pancreas Beta-cells function in adult obese males

    Directory of Open Access Journals (Sweden)

    Mojtaba Eizadi

    2014-08-01

    Conclusion: Aerobic exercise training increases beta cells function and decreases FBS in obese men. These findings support the hypothesis that regular physical activity postpones the occurrence of type 2 diabetes in adult obese subjects.

  2. Beta-Catenin: A Potential Survival Marker of Breast Cancer Stem Cells

    National Research Council Canada - National Science Library

    Chen, Mercy S; Rosen, Jeffrey M

    2005-01-01

    .... It has been established that Wnt/beta-catenin signaling regulates the self renewal of normal stem cells in the hematopoietic system, the epidermis, as well as many other organs, but the importance...

  3. mTOR links incretin signaling to HIF induction in pancreatic beta cells.

    Science.gov (United States)

    Van de Velde, Sam; Hogan, Meghan F; Montminy, Marc

    2011-10-11

    Under feeding conditions, the incretin hormone GLP-1 promotes pancreatic islet viability by triggering the cAMP pathway in beta cells. Increases in PKA activity stimulate the phosphorylation of CREB, which in turn enhances beta cell survival by upregulating IRS2 expression. Although sustained GLP-1 action appears important for its salutary effects on islet function, the transient nature of CREB activation has pointed to the involvement of additional nuclear factors in this process. Following the acute induction of CREB-regulated genes, cAMP triggers a second delayed phase of gene expression that proceeds via the HIF transcription factor. Increases in cAMP promote the accumulation of HIF1α in beta cells by activating the mTOR pathway. As exposure to rapamycin disrupts GLP-1 effects on beta cell viability, these results demonstrate how a pathway associated with tumor growth also mediates salutary effects of an incretin hormone on pancreatic islet function.

  4. Proinflammatory cytokines activate the intrinsic apoptotic pathway in beta-cells

    DEFF Research Database (Denmark)

    Grunnet, Lars G; Aikin, Reid; Tonnesen, Morten F

    2009-01-01

    OBJECTIVE: Proinflammatory cytokines are cytotoxic to beta-cells and have been implicated in the pathogenesis of type 1 diabetes and islet graft failure. The importance of the intrinsic mitochondrial apoptotic pathway in cytokine-induced beta-cell death is unclear. Here, cytokine activation...... of the intrinsic apoptotic pathway and the role of the two proapoptotic Bcl-2 proteins, Bad and Bax, were examined in beta-cells. RESEARCH DESIGN AND METHODS: Human and rat islets and INS-1 cells were exposed to a combination of proinflammatory cytokines (interleukin-1beta, interferon-gamma, and/or tumor necrosis...... to investigate the role of Bad and Bax activation, respectively. RESULTS: We found that proinflammatory cytokines induced calcineurin-dependent dephosphorylation of Bad Ser136, mitochondrial stress, cytochrome c release, activation of caspase-9 and -3, and DNA fragmentation. Inhibition of Bad Ser136...

  5. Cholesterol enhances amyloid {beta} deposition in mouse retina by modulating the activities of A{beta}-regulating enzymes in retinal pigment epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jiying [Department of Ophthalmology and Visual Science, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519 (Japan); Ohno-Matsui, Kyoko, E-mail: k.ohno.oph@tmd.ac.jp [Department of Ophthalmology and Visual Science, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519 (Japan); Morita, Ikuo [Section of Cellular Physiological Chemistry, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519 (Japan)

    2012-08-10

    Highlights: Black-Right-Pointing-Pointer Cholesterol-treated RPE produces more A{beta} than non-treated RPE. Black-Right-Pointing-Pointer Neprilysin expression and activity decreased in cholesterol-treated RPE. Black-Right-Pointing-Pointer {alpha}-Secretase expression and activity decreased in cholesterol-treated RPE. Black-Right-Pointing-Pointer Cholesterol-enriched diet induced subRPE deposits in aged mice. Black-Right-Pointing-Pointer A{beta} were present in cholesterol-enriched-diet-induced subRPE deposits in aged mice. -- Abstract: Subretinally-deposited amyloid {beta} (A{beta}) is a main contributor of developing age-related macular degeneration (AMD). However, the mechanism causing A{beta} deposition in AMD eyes is unknown. Hypercholesterolemia is a significant risk for developing AMD. Thus, we investigated the effects of cholesterol on A{beta} production in retinal pigment epithelial (RPE) cells in vitro and in the mouse retina in vivo. RPE cells isolated from senescent (12-month-old) C57BL/6 mice were treated with 10 {mu}g/ml cholesterol for 48 h. A{beta} amounts in culture supernatants were measured by ELISA. Activity and expression of enzymes and proteins that regulate A{beta} production were examined by activity assay and real time PCR. The retina of mice fed cholesterol-enriched diet was examined by transmission electron microscopy. Cholesterol significantly increased A{beta} production in cultured RPE cells. Activities of A{beta} degradation enzyme; neprilysin (NEP) and anti-amyloidogenic secretase; {alpha}-secretase were significantly decreased in cell lysates of cholesterol-treated RPE cells compared to non-treated cells, but there was no change in the activities of {beta}- or {gamma}-secretase. mRNA levels of NEP and {alpha}-secretase (ADAM10 and ADAM17) were significantly lower in cholesterol-treated RPE cells than non-treated cells. Senescent (12-month-old) mice fed cholesterol-enriched chow developed subRPE deposits containing A{beta}, whereas

  6. Adenoviruses Expressing PDX-1, BETA2/NeuroD and MafA Induces the Transdifferentiation of Porcine Neonatal Pancreas Cell Clusters and Adult Pig Pancreatic Cells into Beta-Cells

    Directory of Open Access Journals (Sweden)

    Young-Hye You

    2011-04-01

    Full Text Available BackgroundA limitation in the number of insulin-producing pancreatic beta-cells is a special feature of diabetes. The identification of alternative sources for the induction of insulin-producing surrogate beta-cells is a matter of profound importance. PDX-1/VP16, BETA2/NeuroD, and MafA overexpression have been shown to influence the differentiation and proliferation of pancreatic stem cells. However, few studies have been conducted using adult animal pancreatic stem cells.MethodsAdult pig pancreatic cells were prepared from the non-endocrine fraction of adult pig pancreata. Porcine neonatal pancreas cell clusters (NPCCs were prepared from neonatal pigs aged 1-2 days. The dispersed pancreatic cells were infected with PDX-1/VP16, BETA2/NeuroD, and MafA adenoviruses. After infection, these cells were transplanted under the kidney capsules of normoglycemic nude mice.ResultsThe adenovirus-mediated overexpression of PDX-1, BETA2/NeuroD and MafA induced insulin gene expression in NPCCs, but not in adult pig pancreatic cells. Immunocytochemistry revealed that the number of insulin-positive cells in NPCCs and adult pig pancreatic cells was approximately 2.6- and 1.1-fold greater than those in the green fluorescent protein control group, respectively. At four weeks after transplantation, the relative volume of insulin-positive cells in the grafts increased in the NPCCs, but not in the adult porcine pancreatic cells.ConclusionThese data indicate that PDX-1, BETA2/NeuroD, and MafA facilitate the beta-cell differentiation of NPCCs, but not adult pig pancreatic cells. Therefore PDX-1, BETA2/NeuroD, and MafA-induced NPCCs can be considered good sources for the induction of pancreatic beta-cells, and may also have some utility in the treatment of diabetes.

  7. Interleukin-1{beta} regulates cell proliferation and activity of extracellular matrix remodelling enzymes in cultured primary pig heart cells

    Energy Technology Data Exchange (ETDEWEB)

    Zitta, Karina; Brandt, Berenice [Department of Anesthesiology and Intensive Care Medicine, University Hospital Schleswig-Holstein, Campus Kiel (Germany); Wuensch, Annegret [Institute of Molecular Animal Breeding and Biotechnology, Ludwig Maximilians University, Munich (Germany); Meybohm, Patrick; Bein, Berthold; Steinfath, Markus; Scholz, Jens [Department of Anesthesiology and Intensive Care Medicine, University Hospital Schleswig-Holstein, Campus Kiel (Germany); Albrecht, Martin, E-mail: Albrecht@anaesthesie.uni-kiel.de [Department of Anesthesiology and Intensive Care Medicine, University Hospital Schleswig-Holstein, Campus Kiel (Germany)

    2010-09-03

    Research highlights: {yields} Levels of IL-1{beta} are increased in the pig myocardium after infarction. {yields} Cultured pig heart cells possess IL-1 receptors. {yields} IL-1{beta} increases cell proliferation of pig heart cells in-vitro. {yields} IL-1{beta} increases MMP-2 and MMP-9 activity in pig heart cells in-vitro. {yields} IL-1{beta} may be important for tissue remodelling events after myocardial infarction. -- Abstract: After myocardial infarction, elevated levels of interleukins (ILs) are found within the myocardial tissue and IL-1{beta} is considered to play a major role in tissue remodelling events throughout the body. In the study presented, we have established a cell culture model of primary pig heart cells to evaluate the effects of different concentrations of IL-1{beta} on cell proliferation as well as expression and activity of enzymes typically involved in tissue remodelling. Primary pig heart cell cultures were derived from three different animals and stimulated with recombinant pig IL-1{beta}. RNA expression was detected by RT-PCR, protein levels were evaluated by Western blotting, activity of matrix metalloproteinases (MMPs) was quantified by gelatine zymography and cell proliferation was measured using colorimetric MTS assays. Pig heart cells express receptors for IL-1 and application of IL-1{beta} resulted in a dose-dependent increase of cell proliferation (P < 0.05 vs. control; 100 ng/ml; 24 h). Gene expression of caspase-3 was increased by IL-1{beta} (P < 0.05 vs. control; 100 ng/ml; 3 h), and pro-caspase-3 but not active caspase was detected in lysates of pig heart cells by Western blotting. MMP-2 gene expression as well as enzymatic activities of MMP-2 and MMP-9 were increased by IL-1{beta} (P < 0.05 vs. control; 100 ng/ml; 3 h for gene expression, 48 and 72 h for enzymatic activities of MMP-2 and MMP-9, respectively). Our in vitro data suggest that IL-1{beta} plays a major role in the events of tissue remodelling in the heart. Combined

  8. Expression of a preproinsulin-beta-galactosidase gene fusion in mammalian cells.

    OpenAIRE

    Nielsen, D A; Chou, J; MacKrell, A J; Casadaban, M J; Steiner, D F

    1983-01-01

    As an approach to the study of mammalian gene expression, the promoters and translation initiation regions of the rat preproinsulin II and the simian virus 40 early genes were fused to the structural gene of Escherichia coli beta-galactosidase, a sensitive probe for gene expression. These fusions were introduced into COS-7 cells, a simian virus 40 large tumor-antigen-producing monkey kidney cell line, where they directed the synthesis of enzymatically active hybrid beta-galactosidase proteins...

  9. Evaluation of beta-cell secretory capacity using glucagon-like peptide 1

    DEFF Research Database (Denmark)

    Vilsbøll, Tina; Nielsen, Mette Toft; Krarup, T

    2000-01-01

    Beta-cell secretory capacity is often evaluated with a glucagon test or a meal test. However, glucagon-like peptide 1 (GLP-1) is the most insulinotropic hormone known, and the effect is preserved in type 2 diabetic patients.......Beta-cell secretory capacity is often evaluated with a glucagon test or a meal test. However, glucagon-like peptide 1 (GLP-1) is the most insulinotropic hormone known, and the effect is preserved in type 2 diabetic patients....

  10. Beta1 integrin-mediated adhesion signalling is essential for epidermal progenitor cell expansion

    DEFF Research Database (Denmark)

    Piwko-Czuchra, Aleksandra; Koegel, Heidi; Meyer, Hannelore

    2009-01-01

    BACKGROUND: There is a major discrepancy between the in vitro and in vivo results regarding the role of beta1 integrins in the maintenance of epidermal stem/progenitor cells. Studies of mice with skin-specific ablation of beta1 integrins suggested that epidermis can form and be maintained in thei...... of increased keratinocyte proliferation such as wound healing. CONCLUSIONS/SIGNIFICANCE: These data demonstrate that expression of beta1 integrins is critically important for the expansion of epidermal progenitor cells to maintain epidermal homeostasis....... that developed similar, but less severe defects than mice with beta1-deficient keratinocytes. Surprisingly we found that upon aging these abnormalities attenuated due to a rapid expansion of cells, which escaped or compensated for the down-regulation of beta1 integrin expression. A similar phenomenon...... was observed in aged mice with a complete, skin-specific ablation of the beta1 integrin gene, where cells that escaped Cre-mediated recombination repopulated the mutant skin in a very short time period. The expansion of beta1 integrin expressing keratinocytes was even further accelerated in situations...

  11. The Cytotoxic Role of Intermittent High Glucose on Apoptosis and Cell Viability in Pancreatic Beta Cells

    Directory of Open Access Journals (Sweden)

    Zhen Zhang

    2014-01-01

    Full Text Available Objectives. Glucose fluctuations are both strong predictor of diabetic complications and crucial factor for beta cell damages. Here we investigated the effect of intermittent high glucose (IHG on both cell apoptosis and proliferation activity in INS-1 cells and the potential mechanisms. Methods. Cells were treated with normal glucose (5.5 mmol/L, constant high glucose (CHG (25 mmol/L, and IHG (rotation per 24 h in 11.1 or 25 mmol/L for 7 days. Reactive oxygen species (ROS, xanthine oxidase (XOD level, apoptosis, cell viability, cell cycle, and expression of cyclinD1, p21, p27, and Skp2 were determined. Results. We found that IHG induced more significant apoptosis than CHG and normal glucose; intracellular ROS and XOD levels were more markedly increased in cells exposed to IHG. Cells treated with IHG showed significant decreased cell viability and increased cell proportion in G0/G1 phase. Cell cycle related proteins such as cyclinD1 and Skp2 were decreased significantly, but expressions of p27 and p21 were increased markedly. Conclusions. This study suggested that IHG plays a more toxic effect including both apoptosis-inducing and antiproliferative effects on INS-1 cells. Excessive activation of cellular stress and regulation of cyclins might be potential mechanism of impairment in INS-1 cells induced by IHG.

  12. Growth arrest- and DNA-damage-inducible 45beta gene inhibits c-Jun N-terminal kinase and extracellular signal-regulated kinase and decreases IL-1beta-induced apoptosis in insulin-producing INS-1E cells

    DEFF Research Database (Denmark)

    Larsen, Claus Morten; Døssing, M G; Papa, S

    2006-01-01

    IL-1beta is a candidate mediator of apoptotic beta cell destruction, a process that leads to type 1 diabetes and progression of type 2 diabetes. IL-1beta activates beta cell c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK) and p38, all of which are members of the mitogen...

  13. Exendin-4 improves blood glucose control in both young and aging normal non-diabetic mice, possible contribution of beta cell independent effects.

    Directory of Open Access Journals (Sweden)

    Rongrong Fan

    Full Text Available AIMS: Type 2 diabetes is highly prevalent in the elderly population. Glucagon like Peptide-1 mimetic such as exendin-4 augments post-prandial insulin secretion. However, the potential influence of aging on the therapeutic effects of this peptide has not been well studied. In this study, we examined the glucose regulatory effects of exendin-4 in mice with different ages. METHODS: We treated 3-month and 20 to 22-month old C57/DBA mice with 10 nM/kg exendin-4 for 10 days with measurements of blood glucose and body weight. We performed OGTT and ITT to evaluate the glucose response and insulin sensitivity. Islet morphology and beta cell mass were measured by immuno-staining and beta cell proliferation was evaluated by BrdU incorporation and PCNA staining. Real-time PCR and western blot were used to measure protein changes in the liver tissue after exendin-4 treatment. RESULTS: Exendin-4 treatment improved glycemic control in both 3-month and 20 to 22-month old mice. In both groups of mice, the blood glucose lowering effect was independent of beta cell function as indicated by unchanged beta cell proliferation, insulin secretion or beta cell mass. Moreover, we found that exendin-4 treatment increased hepatic AKT and FOXO1 phosphorylation and inhibited glucose-6-phosphotase (G6P and Phosphoenolpyruvate carboxykinase (PEPCK expression in young mice, but this effect was attenuated in aging mice while the insulin sensitivity showed no change in the young group but significantly improved in aging mice. CONCLUSION: Based on these data, we conclude that the glucose lowering effect of exendin-4 in normal non-diabetic mice was not blunted by aging. We further showed that although there was slight difference in the glucose modulating mechanism of exendin-4 therapy in young and aged mice, the improved glucose control seemed uncorrelated with increased beta cell mass or insulin secretion.

  14. Regulation of Pancreatic Beta Cell Stimulus-Secretion Coupling by microRNAs

    Directory of Open Access Journals (Sweden)

    Jonathan L. S. Esguerra

    2014-11-01

    Full Text Available Increased blood glucose after a meal is countered by the subsequent increased release of the hypoglycemic hormone insulin from the pancreatic beta cells. The cascade of molecular events encompassing the initial sensing and transport of glucose into the beta cell, culminating with the exocytosis of the insulin large dense core granules (LDCVs is termed “stimulus-secretion coupling.” Impairment in any of the relevant processes leads to insufficient insulin release, which contributes to the development of type 2 diabetes (T2D. The fate of the beta cell, when exposed to environmental triggers of the disease, is determined by the possibility to adapt to the new situation by regulation of gene expression. As established factors of post-transcriptional regulation, microRNAs (miRNAs are well-recognized mediators of beta cell plasticity and adaptation. Here, we put focus on the importance of comprehending the transcriptional regulation of miRNAs, and how miRNAs are implicated in stimulus-secretion coupling, specifically those influencing the late stages of insulin secretion. We suggest that efficient beta cell adaptation requires an optimal balance between transcriptional regulation of miRNAs themselves, and miRNA-dependent gene regulation. The increased knowledge of the beta cell transcriptional network inclusive of non-coding RNAs such as miRNAs is essential in identifying novel targets for the treatment of T2D.

  15. Beta-cell autoantibodies and their function in Taiwanese children with type 1 diabetes mellitus.

    Science.gov (United States)

    Tung, Yi-Ching; Chen, Mei-Huei; Lee, Cheng-Ting; Tsai, Wen-Yu

    2009-11-01

    To understand the importance of autoimmunity in the development of type 1 diabetes in Taiwanese children, we evaluated the presence of beta-cell autoantibodies and their correlation with residual beta-cell function. From 1989 to 2006, 157 Taiwanese children with newly diagnosed type 1 diabetes were enrolled in this study. We determined the presence of beta-cell autoantibodies, such as glutamic acid decarboxylase autoantibodies (GADAs), insulinoma antigen 2 autoantibodies (IA-2As), and insulin autoantibodies (IAAs). A 6-minute glucagon test was also performed at diagnosis. At diagnosis, 73% of children tested positive for GADAs, 76% for IA-2As and 21% for IAAs. Ninety-two percent of them had at least one of the beta-cell autoantibodies detected. Positivity for IAAs was more frequent in patients younger than 5 years than in those older than 5 years (45% vs. 13%). Using multiple regression analysis, the presence of GADAs or IAAs, or age of onset of these patients was an independent factor for residual beta-cell function. Younger patients and those with GADAs had less residual beta-cell function at disease onset, whereas those with IAAs had more insulin reserve. Autoimmunity plays an important role in the pathogenesis of type 1 diabetes in Taiwanese children, and the presence of IAAs tends to be more common in younger children.

  16. Tumor cell adhesion to endothelial cells is increased by endotoxin via an upregulation of beta-1 integrin expression.

    LENUS (Irish Health Repository)

    Andrews, E J

    2012-02-03

    BACKGROUND: Recent studies have demonstrated that metastatic disease develops from tumor cells that adhere to endothelial cells and proliferate intravascularly. The beta-1 integrin family and its ligand laminin have been shown to be important in tumor-to-endothelial cell adhesion. Lipopolysaccharide (LPS) has been implicated in the increased metastatic tumor growth that is seen postoperatively. We postulated that LPS increases tumor cell expression of beta-1 integrins and that this leads to increased adhesion. METHODS: The human metastatic colon cancer cell line LS174T was labeled with an enhanced green fluorescent protein (eGFP) using retroviral transfection. Cell cultures were treated with LPS for 1, 2, and 4 h (n = 6 each) and were subsequently cocultured for 30 or 120 min with confluent human umbilical vein endothelial cells (HUVECs), to allow adherence. Adherent tumor cells were counted using fluorescence microscopy. These experiments were carried out in the presence or absence of a functional blocking beta-1 integrin monoclonal antibody (4B4). Expression of beta-1 integrin and laminin on tumor and HUVECs was assessed using flow cytometric analysis. Tumor cell NF-kappaB activation after incubation with LPS was measured. RESULTS: Tumor cell and HUVEC beta-1 integrin expression and HUVEC expression of laminin were significantly (P < 0.05) enhanced after incubation with LPS. Tumor cell adhesion to HUVECs was significantly increased. Addition of the beta-1 integrin blocking antibody reduced tumor cell adhesion to control levels. LPS increased tumor cell NF-kappaB activation. CONCLUSIONS: Exposure to LPS increases tumor cell adhesion to the endothelium through a beta-1 integrin-mediated pathway that is NF-kappaB dependent. This may provide a target for immunotherapy directed at reducing postoperative metastatic tumor growth.

  17. Effects of ethanol on pancreatic beta-cell death: interaction with glucose and fatty acids.

    Science.gov (United States)

    Dembele, Korami; Nguyen, K Hoa; Hernandez, Tiffany A; Nyomba, B L Grégoire

    2009-04-01

    Western lifestyle plays an important role in the prevalence of type 2 diabetes by causing insulin resistance and pancreatic beta-cell dysfunction, a prerequisite for the development of diabetes. High fat diet and alcohol are major components of the western diet. The aim of the present study was to investigate the effects of ethanol and fatty acids on beta-cell survival and metabolism. We treated the rat beta-cell line RINm5F with ethanol, a mixture of palmitic and oleic acids, or both. Reactive oxygen species (ROS) were determined by (5-(and-6)-chloromethyl-2',7'-dichlorodihydrofluorescein diacetate) (CM-H2DCFDA) fluorescence assay, and mitochondrial activity was assessed by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) reduction assay and by determining ATP production. Cell viability was assessed with a cell counter and trypan blue exclusion, and the mode of cell death by Hoechst33342 and propidium iodide staining. With both ethanol and fatty acid treatments, MTT reduction and ATP production decreased, whereas ROS production increased. Ethanol treatment had no effect on cell number, whereas fatty acid treatment reduced the cell number. Cell incubation with ethanol, fatty acids, or both increased the number of Hoechst 33342-positive nuclei. However, the majority of nuclei from fatty acid-treated cells were stained with propidium iodide, indicating a loss of plasma membrane integrity. We conclude that both ethanol and fatty acids generate cellular oxidative stress, and affect mitochondrial function in RINm5F beta-cells. However, ethanol causes beta-cell death by apoptosis, whereas fatty acids cause cell death predominantly by necrosis. It is not known whether these results are applicable to human beta-cells.

  18. Alpha9beta1 integrin in melanoma cells can signal different adhesion states for migration and anchorage

    DEFF Research Database (Denmark)

    Lydolph, Magnus C; Morgan-Fisher, Marie; Høye, Anette M

    2009-01-01

    Cell surface integrins are the primary receptors for cell migration on extracellular matrix, and exist in several activation states regulated in part by ectodomain conformation. The alpha9 integrin subunit, which pairs only with beta1, has specific roles in the immune system and may regulate cell...... migration. Melanoma cells express abundant alpha9beta1 integrin, and its role in cell migration was assessed. Ligands derived from Tenascin-C and ADAM12 supported alpha9beta1 integrin-mediated cell attachment and GTP-Rac dependent migration, but not focal adhesion formation. Manganese ions induced alpha9......beta1 integrin- and Rho kinase-dependent focal adhesion and stress fibre formation, suggesting that the activation status of alpha9beta1 integrin was altered. The effect of manganese ions in promoting focal adhesion formation was reproduced by beta1 integrin activating antibody. The alpha9beta1...

  19. Identification of alpha beta and gamma delta T cell receptor-positive cells

    DEFF Research Database (Denmark)

    Geisler, C; Larsen, J K; Plesner, T

    1988-01-01

    distribution and function of these different T cells. In immunofluorescence studies gamma delta TCR+ cells have been identified as CD3+WT-31- or CD3+CD4-CD8- cells. However, this may not be the optimal procedure because gamma delta TCR+ cells are weakly WT-31+, and some are CD8+. The aim of this study...... was to evaluate a panel of monoclonal antibodies (MoAb) directed against different chains of the TCR-T3 complex for a more precise identification of alpha beta+ and gamma delta TCR+ cells in flow cytometric studies. We found that the MoAb anti-Ti-gamma A and delta-TCS-1, recognizing the TCR-gamma and the TCR...

  20. The effect of smoking cessation pharmacotherapies on pancreatic beta cell function

    International Nuclear Information System (INIS)

    Woynillowicz, Amanda K.; Raha, Sandeep; Nicholson, Catherine J.; Holloway, Alison C.

    2012-01-01

    The goal of our study was to evaluate whether drugs currently used for smoking cessation (i.e., nicotine replacement therapy, varenicline [a partial agonist at nicotinic acetylcholine receptors (nAChR)] and bupropion [which acts in part as a nAChR antagonist]) can affect beta cell function and determine the mechanism(s) of this effect. INS-1E cells, a rat beta cell line, were treated with nicotine, varenicline and bupropion to determine their effects on beta cell function, mitochondrial electron transport chain enzyme activity and cellular/oxidative stress. Treatment of INS-1E cells with equimolar concentrations (1 μM) of three test compounds resulted in an ablation of normal glucose-stimulated insulin secretion by the cells. This disruption of normal beta cell function was associated with mitochondrial dysfunction since all three compounds tested significantly decreased the activity of mitochondrial electron transport chain enzyme activity. These results raise the possibility that the currently available smoking cessation pharmacotherapies may also have adverse effects on beta cell function and thus glycemic control in vivo. Therefore whether or not the use of nicotine replacement therapy, varenicline and bupropion can cause endocrine changes which are consistent with impaired pancreatic function warrants further investigation. -- Highlights: ► Smoking cessation drugs have the potential to disrupt beta cell function in vitro. ► The effects of nicotine, varenicline and bupropion are similar. ► The impaired beta cell function is mediated by mitochondrial dysfunction. ► If similar effects are seen in vivo, these drugs may increase the risk of diabetes.

  1. The effect of smoking cessation pharmacotherapies on pancreatic beta cell function

    Energy Technology Data Exchange (ETDEWEB)

    Woynillowicz, Amanda K. [Department of Obstetrics and Gynecology, McMaster University, Hamilton, ON, Canada L8N 3Z5 (Canada); Raha, Sandeep [Department of Pediatrics, McMaster University, Hamilton, ON, Canada L8N 3Z5 (Canada); Nicholson, Catherine J. [Department of Obstetrics and Gynecology, McMaster University, Hamilton, ON, Canada L8N 3Z5 (Canada); Holloway, Alison C., E-mail: hollow@mcmaster.ca [Department of Obstetrics and Gynecology, McMaster University, Hamilton, ON, Canada L8N 3Z5 (Canada)

    2012-11-15

    The goal of our study was to evaluate whether drugs currently used for smoking cessation (i.e., nicotine replacement therapy, varenicline [a partial agonist at nicotinic acetylcholine receptors (nAChR)] and bupropion [which acts in part as a nAChR antagonist]) can affect beta cell function and determine the mechanism(s) of this effect. INS-1E cells, a rat beta cell line, were treated with nicotine, varenicline and bupropion to determine their effects on beta cell function, mitochondrial electron transport chain enzyme activity and cellular/oxidative stress. Treatment of INS-1E cells with equimolar concentrations (1 μM) of three test compounds resulted in an ablation of normal glucose-stimulated insulin secretion by the cells. This disruption of normal beta cell function was associated with mitochondrial dysfunction since all three compounds tested significantly decreased the activity of mitochondrial electron transport chain enzyme activity. These results raise the possibility that the currently available smoking cessation pharmacotherapies may also have adverse effects on beta cell function and thus glycemic control in vivo. Therefore whether or not the use of nicotine replacement therapy, varenicline and bupropion can cause endocrine changes which are consistent with impaired pancreatic function warrants further investigation. -- Highlights: ► Smoking cessation drugs have the potential to disrupt beta cell function in vitro. ► The effects of nicotine, varenicline and bupropion are similar. ► The impaired beta cell function is mediated by mitochondrial dysfunction. ► If similar effects are seen in vivo, these drugs may increase the risk of diabetes.

  2. Interleukin-1beta regulates cell proliferation and activity of extracellular matrix remodelling enzymes in cultured primary pig heart cells.

    Science.gov (United States)

    Zitta, Karina; Brandt, Berenice; Wuensch, Annegret; Meybohm, Patrick; Bein, Berthold; Steinfath, Markus; Scholz, Jens; Albrecht, Martin

    2010-09-03

    After myocardial infarction, elevated levels of interleukins (ILs) are found within the myocardial tissue and IL-1beta is considered to play a major role in tissue remodelling events throughout the body. In the study presented, we have established a cell culture model of primary pig heart cells to evaluate the effects of different concentrations of IL-1beta on cell proliferation as well as expression and activity of enzymes typically involved in tissue remodelling. Primary pig heart cell cultures were derived from three different animals and stimulated with recombinant pig IL-1beta. RNA expression was detected by RT-PCR, protein levels were evaluated by Western blotting, activity of matrix metalloproteinases (MMPs) was quantified by gelatine zymography and cell proliferation was measured using colorimetric MTS assays. Pig heart cells express receptors for IL-1 and application of IL-1beta resulted in a dose-dependent increase of cell proliferation (Ppig heart cells by Western blotting. MMP-2 gene expression as well as enzymatic activities of MMP-2 and MMP-9 were increased by IL-1beta (Pheart. Combined with our recently published in vivo data (Meybohm et al., PLoS One, 2009), the results presented here strongly suggest IL-1beta as a key molecule guiding tissue remodelling events after myocardial infarction. Copyright 2010 Elsevier Inc. All rights reserved.

  3. Differentiation of Boc-protected alpha,delta-/delta,alpha- and beta,delta-/delta,beta-hybrid peptide positional isomers by electrospray ionization tandem mass spectrometry.

    Science.gov (United States)

    Raju, G; Ramesh, V; Srinivas, R; Sharma, G V M; Shoban Babu, B

    2010-06-01

    Two new series of Boc-N-alpha,delta-/delta,alpha- and beta,delta-/delta,beta-hybrid peptides containing repeats of L-Ala-delta(5)-Caa/delta(5)-Caa-L-Ala and beta(3)-Caa-delta(5)-Caa/delta(5)-Caa-beta(3)-Caa (L-Ala = L-alanine, Caa = C-linked carbo amino acid derived from D-xylose) have been differentiated by both positive and negative ion electrospray ionization (ESI) ion trap tandem mass spectrometry (MS/MS). MS(n) spectra of protonated isomeric peptides produce characteristic fragmentation involving the peptide backbone, the Boc-group, and the side chain. The dipeptide positional isomers are differentiated by the collision-induced dissociation (CID) of the protonated peptides. The loss of 2-methylprop-1-ene is more pronounced for Boc-NH-L-Ala-delta-Caa-OCH(3) (1), whereas it is totally absent for its positional isomer Boc-NH-delta-Caa-L-Ala-OCH(3) (7), instead it shows significant loss of t-butanol. On the other hand, second isomeric pair shows significant loss of t-butanol and loss of acetone for Boc-NH-delta-Caa-beta-Caa-OCH(3) (18), whereas these are insignificant for its positional isomer Boc-NH-beta-Caa-delta-Caa-OCH(3) (13). The tetra- and hexapeptide positional isomers also show significant differences in MS(2) and MS(3) CID spectra. It is observed that 'b' ions are abundant when oxazolone structures are formed through five-membered cyclic transition state and cyclization process for larger 'b' ions led to its insignificant abundance. However, b(1)(+) ion is formed in case of delta,alpha-dipeptide that may have a six-membered substituted piperidone ion structure. Furthermore, ESI negative ion MS/MS has also been found to be useful for differentiating these isomeric peptide acids. Thus, the results of MS/MS of pairs of di-, tetra-, and hexapeptide positional isomers provide peptide sequencing information and distinguish the positional isomers. Copyright 2010 John Wiley & Sons, Ltd.

  4. Osteopontin Affects Insulin Vesicle Localization and Ca2+ Homeostasis in Pancreatic Beta Cells from Female Mice.

    Directory of Open Access Journals (Sweden)

    Anna Wendt

    Full Text Available Type 2 diabetic patients suffer from insulin resistance and reduced insulin secretion. Osteopontin (OPN, a versatile protein expressed in several tissues throughout the body including the islets of Langerhans, has previously been implicated in the development of insulin resistance. Here we have investigated the role of OPN in insulin secretion using an OPN knock out mouse model (OPN-/-. Ultra-structural analyzes of islets from OPN-/- and WT mice indicated weaker cell-cell connections between the islet cells in the OPN-/- mouse compared to WT. Analysis of the insulin granule distribution in the beta cells showed that although OPN-/- and WT beta cells have the same number of insulin granules OPN-/- beta cells have significantly fewer docked granules. Both OPN-/- and WT islets displayed synchronized Ca2+ oscillations indicative of an intact beta cell communication. OPN-/- islets displayed higher intracellular Ca2+ concentrations when stimulated with 16.7 mM glucose than WT islets and the initial dip upon elevated glucose concentrations (which is associated with Ca2+ uptake into ER was significantly lower in these islets. Glucose-induced insulin secretion was similar in OPN-/- and WT islets. Likewise, non-fasted blood glucose levels were the same in both groups. In summary, deletion of OPN results in several minor beta-cell defects that can be compensated for in a healthy system.

  5. Effect of Nɛ-carboxymethyllysine on oxidative stress and the glutathione system in beta cells

    Directory of Open Access Journals (Sweden)

    Daniëlle M.P.H.J. Boesten

    2014-01-01

    Full Text Available One of the pathways involved in the pathogenesis of diabetic complications is the formation of excessive levels of advanced glycation end (AGE products. Nɛ-carboxymethyllysine (CML is one of the best-characterized AGEs. Because little is known about the effects of AGEs on pancreatic beta cells, we investigated the effect of CML on human pancreatic cells and determined the activity and gene expression of glutathione system components. CML at a concentration of 0.5 mM induced cell death in human pancreatic beta cells, which was accompanied by increased intracellular oxidative stress. No changes in the gene expression of the receptor for AGEs (RAGE were found, although an increase in the level of a target cytokine of RAGE after CML exposure was observed. Additionally we found that CML lowered the levels of GSH and affected the activity and expression of other components of the glutathione system. These changes indicate that the cells are even more vulnerable for oxidative stress after exposure to CML. Since beta cells are low in antioxidant enzymes and repair for oxidized DNA, CML, but most likely also other AGEs, accelerates beta cell dysfunction and increases beta cell death during chronic hyperglycemia.

  6. CRFR1 is expressed on pancreatic beta cells, promotes beta cell proliferation, and potentiates insulin secretion in a glucose-dependent manner

    DEFF Research Database (Denmark)

    Huising, Mark O; van der Meulen, Talitha; Vaughan, Joan M

    2009-01-01

    Corticotropin-releasing factor (CRF), originally characterized as the principal neuroregulator of the hypothalamus-pituitary-adrenal axis, has broad central and peripheral distribution and actions. We demonstrate the presence of CRF receptor type 1 (CRFR1) on primary beta cells and show that acti...

  7. Glucose transport by radiation-induced insulinoma and clonal pancreatic beta-cells

    International Nuclear Information System (INIS)

    Meglasson, M.D.; Manning, C.D.; Najafi, H.; Matschinsky, F.M.

    1986-01-01

    Sugar uptake was measured in dispersed cells prepared from radiation-induced insulinomas transplantable in NEDH rats and in three clonal beta-cell lines maintained in continuous culture (RIN m5F, RIN 1046, HIT). Uptake of D-glucose and 3-O-methyl-D-glucose by insulinoma cells was rapid so that the intracellular concentration of D-hexoses approximated the concentration in the incubation medium by 15-30 s. L-Glucose was taken up only slowly. 3-O-methyl-D-glucose uptake by RIN m5F, RIN 1046, and HIT cells was slow; with 1 mM 3-O-methylglucose in the medium, equilibrium was attained at 20 min, but with 10 mM 3-O-methylglucose, equilibrium was not attained even at 20 min. In HIT cells incubated with D-glucose for 30 min, the intracellular concentration of glucose was less than the medium glucose concentration, indicating glucose transport is a nonequilibrium reaction in this cell line. These data indicate that radiation-induced insulinoma cells retain the capacity of normal beta-cells to transport sugar at high rates. RIN m5F, RIN 1046, and HIT cells transport sugar slowly, however, and thus differ from normal beta-cells. In RIN m5F, RIN 1046, and HIT cells, unlike in normal beta-cells, glucose transport may be the site regulating glucose metabolism

  8. Diagnostic significance of red cell indices in beta-thalassaemia trait

    International Nuclear Information System (INIS)

    Hussain, Z.; Malik, N.; Chughtai, A.S.

    2005-01-01

    The purpose of this study was to evaluate the formulae for the diagnosis of beta-thalassemia trait cases in settings where electrophoreses is not available. The study included 50 cases of beta-thalassaemia trait already diagnosed by Hb electrophoresis. CBC samples were analyzed on Sysmex K4500 and red cell indices were used to evaluate formulae for differentiating beta thalassaemia trait from iron deficiency anemia. The formula MCV/RBC and MCH/RBC identified 56% of the cases. Formula MCV - (5 x Hb)- RBC - 8.4 identified 54% of beta thalassemia trait cases. The formula MCV x MCH identified 92% of cases. RBC indices given by 100 electronic counters can be used to differentiate iron deficiency anemia from beta-thalassaemia trait at least provisionally in areas where Hb electrophoresis is not available. (author)

  9. Low-energy. beta. -function in a finite super-Yang-Mills model with multiple mass scales

    Energy Technology Data Exchange (ETDEWEB)

    Foda, O.; Helayel-Neto, J.A. (International Centre for Theoretical Physics, Trieste (Italy))

    1985-02-14

    We compute the one-loop contribution to the low-energy light-fermion gauge coupling in a finite supersymmetric gauge theory with two mass scales: a heavy mass that breaks an initial N=4 supersymmetry down to N=2, but respects the finiteness, and a light mass that, for simplicity, is set to zero. We find that coupling grows with the mass of the heavy intermediate states. Hence the latter do not decouple at low energies, leading to large logarithms that invalidate low-energy perturbation theory. Consequently, further manipulations are required to obtain a meaningful perturbative expansion. Enforcing decoupling through finite renormalizations, that absorb the heavy mass effects into a redefinition of the parameters of the lagrangian, introduces an arbitrary subtraction mass ..mu... The requirement that the S-matrix elements be independent of ..mu.. leads to a non-trivial renormalization-group equation for the low-energy theory, with a non-vanishing ..beta..-function.

  10. T Cell-Mediated Beta Cell Destruction: Autoimmunity and Alloimmunity in the Context of Type 1 Diabetes

    Directory of Open Access Journals (Sweden)

    Adam L. Burrack

    2017-12-01

    Full Text Available Type 1 diabetes (T1D results from destruction of pancreatic beta cells by T cells of the immune system. Despite improvements in insulin analogs and continuous blood glucose level monitoring, there is no cure for T1D, and some individuals develop life-threatening complications. Pancreas and islet transplantation have been attractive therapeutic approaches; however, transplants containing insulin-producing cells are vulnerable to both recurrent autoimmunity and conventional allograft rejection. Current immune suppression treatments subdue the immune system, but not without complications. Ideally a successful approach would target only the destructive immune cells and leave the remaining immune system intact to fight foreign pathogens. This review discusses the autoimmune diabetes disease process, diabetic complications that warrant a transplant, and alloimmunity. First, we describe the current understanding of autoimmune destruction of beta cells including the roles of CD4 and CD8 T cells and several possibilities for antigen-specific tolerance induction. Second, we outline diabetic complications necessitating beta cell replacement. Third, we discuss transplant recognition, potential sources for beta cell replacement, and tolerance-promoting therapies under development. We hypothesize that a better understanding of autoreactive T cell targets during disease pathogenesis and alloimmunity following transplant destruction could enhance attempts to re-establish tolerance to beta cells.

  11. PDX1, Neurogenin-3, and MAFA: critical transcription regulators for beta cell development and regeneration

    Directory of Open Access Journals (Sweden)

    Yaxi Zhu

    2017-11-01

    Full Text Available Abstract Transcription factors regulate gene expression through binding to specific enhancer sequences. Pancreas/duodenum homeobox protein 1 (PDX1, Neurogenin-3 (NEUROG3, and V-maf musculoaponeurotic fibrosarcoma oncogene homolog A (MAFA are transcription factors critical for beta cell development and maturation. NEUROG3 is expressed in endocrine progenitor cells and controls islet differentiation and regeneration. PDX1 is essential for the development of pancreatic exocrine and endocrine cells including beta cells. PDX1 also binds to the regulatory elements and increases insulin gene transcription. Likewise, MAFA binds to the enhancer/promoter region of the insulin gene and drives insulin expression in response to glucose. In addition to those natural roles in beta cell development and maturation, ectopic expression of PDX1, NEUROG3, and/or MAFA has been successfully used to reprogram various cell types into insulin-producing cells in vitro and in vivo, such as pancreatic exocrine cells, hepatocytes, and pluripotent stem cells. Here, we review biological properties of PDX1, NEUROG3, and MAFA, and their applications and limitations for beta cell regenerative approaches. The primary source literature for this review was acquired using a PubMed search for articles published between 1990 and 2017. Search terms include diabetes, insulin, trans-differentiation, stem cells, and regenerative medicine.

  12. Anti-beta2 glycoprotein I antibodies cause inflammation and recruit dendritic cells in platelet clearance.

    Science.gov (United States)

    Bondanza, A; Manfredi, A A; Zimmermann, V S; Iannacone, M; Tincani, A; Balestrieri, G; Sabbadini, M G; Querini, P R

    2001-11-01

    Scavenger phagocytes are mostly responsible for the in vivo clearance of activated or senescent platelets. In contrast to other particulate substrates, the phagocytosis of platelets does not incite proinflammatory responses in vivo. This study assessed the contribution of macrophages and dendritic cells (DCs) to the clearance of activated platelets. Furthermore, we verified whether antibodies against the beta2 Glycoprotein I (beta2GPI), which bind to activated platelets, influence the phenomenon. DCs did not per se intemalise activated platelets. In contrast, macrophages efficiently phagocytosed platelets. In agreement with the uneventful nature of the clearance of platelets in vivo, phagocytosing macrophages did not release IL-1beta, TNF-alpha, or IL-10, beta2GPI bound to activated platelets and was required for their recognition by anti-beta2GPI antibodies. DCs internalised platelets opsonised by anti-beta2GPI antibodies. The phagocytosis of opsonised platelets determined the release of TNF-alpha and IL-1beta by DCs and macrophages. Phagocytosing macrophages, but not DCs, secreted the antiinflammatory cytokine IL-10. We conclude that anti-beta2GPI antibodies cause inflammation during platelet clearance and shuttle platelet antigens to antigen presenting DCs.

  13. Effect of long-term transfusion therapy on the glycometabolic status and pancreatic beta cell function in patients with beta Thalassemia major

    Directory of Open Access Journals (Sweden)

    Kamalakshi G Bhat

    2014-01-01

    Full Text Available Background: Diabetes mellitus is a major complication of iron overload in patients with beta thalassemia major. Design: This is a descriptive study conducted in a Tertiary Care Teaching Hospital to analyze beta cell function and insulin resistance, and their relation to iron overload status in beta thalassemia major. Fasting glucose, two-hour post load glucose, fasting insulin, alanine amino transaminase (ALT, and ferritin were used as outcome measures. The homeostatic model assessment (HOMA model was used to calculate the beta cell function and insulin resistance index. Results: Of the 30 cases, 20% had impaired fasting glucose, 3.3% had impaired glucose tolerance, and none had diabetes. Fasting glucose was not significant between the cases and controls (P = 0.113. Fasting insulin (P = 0.001, ferritin (P = 0.001, and ALT (P = 0.001 levels were significantly high in the cases. Insulin resistance index was significantly higher in the cases (P = 0.001 as also the beta cell function (P = 0.001. With increase in age and the number of units transfused there is a decline in beta cell function, fasting insulin, and insulin resistance after attaining the maximum level. This suggests that initial insulin resistance is followed by insulin depletion due to loss of beta cell function, leading to diabetes mellitus. Conclusion: Impaired glucose tolerance (IGT and insulin resistance precede the onset of insulin-dependent diabetes and adequate chelation therapy is essential for delaying the onset or for prevention of diabetes.

  14. Phenotypic and gene expression changes between low (glucose-responsive) and High (glucose non-responsive) MIN-6 beta cells

    DEFF Research Database (Denmark)

    O´Driscoll, L.; Gammell, p.; McKierman, E.

    2006-01-01

    The long-term potential to routinely use replacement beta cells/islets as cell therapy for type 1 diabetes relies on our ability to culture such cells/islets, in vitro, while maintaining their functional status. Previous beta cell studies, by ourselves and other researchers, have indicated that t...

  15. Beta-irradiation used for systemic radioimmunotherapy induces apoptosis and activates apoptosis pathways in leukaemia cells

    International Nuclear Information System (INIS)

    Friesen, Claudia; Lubatschofski, Annelie; Debatin, Klaus-Michael; Kotzerke, Joerg; Buchmann, Inga; Reske, Sven N.

    2003-01-01

    Beta-irradiation used for systemic radioimmunotherapy (RIT) is a promising treatment approach for high-risk leukaemia and lymphoma. In bone marrow-selective radioimmunotherapy, beta-irradiation is applied using iodine-131, yttrium-90 or rhenium-188 labelled radioimmunoconjugates. However, the mechanisms by which beta-irradiation induces cell death are not understood at the molecular level. Here, we report that beta-irradiation induced apoptosis and activated apoptosis pathways in leukaemia cells depending on doses, time points and dose rates. After beta-irradiation, upregulation of CD95 ligand and CD95 receptor was detected and activation of caspases resulting in apoptosis was found. These effects were completely blocked by the broad-range caspase inhibitor zVAD-fmk. In addition, irradiation-mediated mitochondrial damage resulted in perturbation of mitochondrial membrane potential, caspase-9 activation and cytochrome c release. Bax, a death-promoting protein, was upregulated and Bcl-x L , a death-inhibiting protein, was downregulated. We also found higher apoptosis rates and earlier activation of apoptosis pathways after gamma-irradiation in comparison to beta-irradiation at the same dose rate. Furthermore, irradiation-resistant cells were cross-resistant to CD95 and CD95-resistant cells were cross-resistant to irradiation, indicating that CD95 and irradiation used, at least in part, identical effector pathways. These findings demonstrate that beta-irradiation induces apoptosis and activates apoptosis pathways in leukaemia cells using both mitochondrial and death receptor pathways. Understanding the timing, sequence and molecular pathways of beta-irradiation-mediated apoptosis may allow rational adjustment of chemo- and radiotherapeutic strategies. (orig.)

  16. Selective modulation of ER-beta by estradiol and xenoestrogens in human breast cancer cell lines.

    Science.gov (United States)

    Cappelletti, V; Saturno, G; Miodini, P; Körner, W; Daidone, M G

    2003-03-01

    In the last decades, substances with estrogenic activity have been dispersed into the environment. Xenoestrogens act by binding to estrogen receptors, ligand-regulated transcription factors, for which two subtypes have been described, ER-alpha and ER-beta, which are often coexpressed at variable amounts in different tissues. We investigated variations in the expression of ER-alpha and ER-beta mRNAs following treatment with four xenoestrogens (bisphenol A, 4-tert octylphenol, 2-hydroxybiphenyl, 4-hydroxybiphenyl) and with 17beta-estradiol in estrogen-sensitive (T47D) and estrogen-insensitive (BT20) breast cancer cell lines. Although to a variable extent, both estradiol and the tested xenoestrogens increased the expression of ER-beta mRNA, whereas a slight effect on ER-alpha was observed only in T47D cells. Upregulation of ER-beta expression by estradiol and xenoestrogens was observed only in the presence of detectable ER-alpha protein levels. These findings indicate a regulatory role for ER-beta in ER-alpha-mediated transcription and a role for ER-beta in mediating xenoestrogen toxicity.

  17. Marked over expression of uncoupling protein-2 in beta cells exerts minor effects on mitochondrial metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Hals, Ingrid K., E-mail: ingrid.hals@ntnu.no [Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology (NTNU), Trondheim (Norway); Ogata, Hirotaka; Pettersen, Elin [Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology (NTNU), Trondheim (Norway); Ma, Zuheng; Bjoerklund, Anneli [Department of Molecular Medicine and Surgery, Karolinska Institute, Stockholm (Sweden); Skorpen, Frank [Department of Laboratory Medicine, NTNU, Trondheim (Norway); Egeberg, Kjartan Wollo [Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology (NTNU), Trondheim (Norway); Grill, Valdemar [Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology (NTNU), Trondheim (Norway); Department of Molecular Medicine and Surgery, Karolinska Institute, Stockholm (Sweden)

    2012-06-29

    Highlights: Black-Right-Pointing-Pointer The impact of UCP-2 over expression on mitochondrial function is controversial. Black-Right-Pointing-Pointer We tested mitochondrial functions at defined levels of overexpression. Black-Right-Pointing-Pointer We find minor increases of fatty acid oxidation and uncoupling. Black-Right-Pointing-Pointer Effects were seen only at high level (fourfold) of over expression. Black-Right-Pointing-Pointer Hence it is doubtful whether these effects are of importance in diabetes. -- Abstract: Evidence is conflicting as to the impact of elevated levels of uncoupling protein-2 (UCP-2) on insulin-producing beta cells. Here we investigated effects of a fourfold induction of UCP-2 protein primarily on mitochondrial parameters and tested for replication of positive findings at a lower level of induction. We transfected INS-1 cells to obtain a tet-on inducible cell line. A 48 h exposure to 1 {mu}g/ml of doxycycline (dox) induced UCP-2 fourfold (424 {+-} 113%, mean {+-} SEM) and 0.1 {mu}g/ml twofold (178 {+-} 29%, n = 3). Fourfold induced cells displayed normal viability (MTT, apoptosis), normal cellular insulin contents and, glucose-induced insulin secretion (+27 {+-} 11%) as well as D-[U-{sup 14}C]-glucose oxidation (+5 {+-} 9% at 11 mM glucose). Oxidation of [1-{sup 14}C]-oleate was increased from 4088 to 5797 fmol/{mu}g prot/2 h at 3.3 mM glucose, p < 0.03. Oxidation of L-[{sup 14}C(U)]-glutamine was unaffected. Induction of UCP-2 did not significantly affect measures of mitochondrial membrane potential (Rhodamine 123) or mitochondrial mass (Mitotracker Green) and did not affect ATP levels. Oligomycin-inhibited oxygen consumption (a measure of mitochondrial uncoupling) was marginally increased, the effect being significant in comparison with dox-only treated cells, p < 0.05. Oxygen radicals, assessed by dichlorofluorescin diacetate, were decreased by 30%, p < 0.025. Testing for the lower level of UCP-2 induction did not reproduce any of the

  18. Pancreatic beta cells from db/db mice show cell-specific [Ca2+]i and NADH responses to glucose but not to alpha-ketoisocaproic acid

    DEFF Research Database (Denmark)

    Gustavsson, Natalia; Larsson-Nyrén, Gerd; Lindström, Per

    2005-01-01

    induced cell-specific NADH responses in all 3 models, but KIC did so only in lean mouse [beta] cells. CONCLUSIONS: A cell-specific response may be induced at several steps of beta-cell stimulus-secretion coupling. Mitochondrial metabolism generates a cell-specific response in normal beta cells......OBJECTIVE: We recently showed that timing and magnitude of the glucose-induced cytoplasmic calcium [Ca2+]i response are reproducible and specific for the individual beta cell. We now wanted to identify which step(s) of stimulus-secretion coupling determine the cell specificity of the [Ca2+]i...

  19. Chronic fetal hypoglycemia inhibits the later steps of stimulus-secretion coupling in pancreatic beta-cells.

    Science.gov (United States)

    Rozance, Paul J; Limesand, Sean W; Zerbe, Gary O; Hay, William W

    2007-05-01

    We measured the impact of chronic late gestation hypoglycemia on pancreatic islet structure and function to determine the cause of decreased insulin secretion in this sheep model of fetal nutrient deprivation. Late gestation hypoglycemia did not decrease pancreas weight, insulin content, beta-cell area, beta-cell mass, or islet size. The pancreatic islet isolation procedure selected a group of islets that were larger and had an increased proportion of beta-cells compared with islets measured in pancreatic sections, but there were no morphologic differences between islets isolated from control and hypoglycemic fetuses. The rates of glucose-stimulated pancreatic islet glucose utilization (126.2 +/- 25.3 pmol glucose.islet(-1).h(-1), hypoglycemic, vs. 93.5 +/- 5.5 pmol glucose.islet(-1).h(-1), control, P = 0.47) and oxidation (10.5 +/- 1.7 pmol glucose.islet(-1).h(-1), hypoglycemic, vs. 10.6 +/- 1.6 pmol glucose.islet(-1).h(-1), control) were not different in hypoglycemic fetuses compared with control fetuses. Chronic late gestation hypoglycemia decreased insulin secretion in isolated pancreatic islets by almost 70% in response to direct nonnutrient membrane depolarization and in response to increased extracellular calcium entry. beta-Cell ultrastructure was abnormal with markedly distended rough endoplasmic reticulum in three of the seven hypoglycemic fetuses studied, but in vitro analysis of hypoglycemic control islets showed no evidence that these changes represented endoplasmic reticulum stress, as measured by transcription of glucose regulatory protein-78 and processing of X-box binding protein-1. In conclusion, these studies show that chronic hypoglycemia in late gestation decreases insulin secretion by inhibiting the later steps of stimulus-secretion coupling after glucose metabolism, membrane depolarization, and calcium entry.

  20. TGF-betas: their role in testicular function and Sertoli cell tight junction dynamics.

    Science.gov (United States)

    Lui, Wing-Yee; Lee, Will M; Cheng, C Yan

    2003-06-01

    Transforming growth factor-betas (TGF-betas) are known to regulate multiple physiological functions in the testis, which include spermatogenesis, Leydig cell steroidogenesis, extracellular matrix synthesis and testis development. More recent studies have shown that TGF-beta3 also regulates Sertoli cell tight junction (TJ) dynamics in vitro via the p38 mitogen-activated protein (MAP) kinase pathway, suggesting that this cytokine plays a crucial role in regulating the opening and closing of the blood-testis barrier (BTB). This in turn regulates the passage of pre-leptotene and leptotene spermatocytes across the BTB at stages VIII-XI of the seminiferous epithelial cycle. This review summarizes recent advances of studies on TGF-betas in the testis, highlighting their regulatory role in TJ dynamics.

  1. Cellular trafficking of thymosin beta-4 in HEPG2 cells following serum starvation.

    Directory of Open Access Journals (Sweden)

    Giuseppina Pichiri

    Full Text Available Thymosin beta-4 (Tβ4 is an ubiquitous multi-functional regenerative peptide, related to many critical biological processes, with a dynamic and flexible conformation which may influence its functions and its subcellular distribution. For these reasons, the intracellular localization and trafficking of Tβ4 is still not completely defined and is still under investigation in in vivo as well as in vitro studies. In the current study we used HepG2 cells, a human hepatoma cell line; cells growing in normal conditions with fetal bovine serum expressed high levels of Tβ4, restricted to the cytoplasm until 72 h. At 84 h, a diffuse Tβ4 cytoplasmic immunostaining shifted to a focal perinuclear and nuclear reactivity. In the absence of serum, nuclear reactivity was localized in small granules, evenly dispersed throughout the entire nuclear envelop, and was observed as earlier as at 48 h. Cytoplasmic immunostaining for Tβ4 in HepG2 cells under starvation appeared significantly lower at 48 h and decreased progressively at 72 and at 84 h. At these time points, the decrease in cytoplasmic staining was associated with a progressive increase in nuclear reactivity, suggesting a possible translocation of the peptide from the cytoplasm to the nuclear membrane. The normal immunocytochemical pattern was restored when culture cells submitted to starvation for 84 h received a new complete medium for 48 h. Mass spectrometry analysis, performed on the nuclear and cytosolic fractions of HepG2 growing with and without serum, showed that Tβ4 was detectable only in the cytosolic and not in the intranuclear fraction. These data suggest that Tβ4 is able to translocate from different cytoplasmic domains to the nuclear membrane and back, based on different stress conditions within the cell. The punctuate pattern of nuclear Tβ4 immunostaining associated with Tβ4 absence in the nucleoplasm suggest that this peptide might be localized in the nuclear pores, where it could

  2. Glucocorticoids suppress beta-cell development and induce hepatic metaplasia in embryonic pancreas.

    Science.gov (United States)

    Shen, Chia-Ning; Seckl, Jonathan R; Slack, Jonathan M W; Tosh, David

    2003-10-01

    Elevated glucocorticoids are associated with low birth weight and fetal 'programming' of hypertension and glucose intolerance. In the present paper, we show that treatment of fetal rats with dexamethasone during the last week of gestation reduces the insulin content of their pancreatic beta-cells. We reproduce this effect of dexamethasone in vitro using organ cultures of mouse embryonic pancreas, and show that it is associated with an elevation of expression of the transcription factor C/EBPbeta (CCAAT/enhancer-binding protein beta) and a reduction of the transcription factor Pdx-1 (pancreatic duodenal homeobox-1). Dexamethasone also induces the appearance of hepatocyte-like cells in organ cultures of pancreas, based on the expression of liver markers, albumin, alpha1-antitrypsin and transthyretin. Evidence that C/EBPbeta is responsible for compromising the differentiation and later function of beta-cells is obtained from its effects on the beta-cell-like cell line RIN-5F. Transfection with a constitutive form of C/EBPb suppresses insulin formation, whereas introduction of a dominant-negative inhibitor of C/EBPb has no effect. We conclude that dexamethasone inhibits insulin expression in pancreatic beta-cells via a mechanism involving down-regulation of Pdx-1 and induction of C/EBPbeta. This mechanism may operate in combination with other changes during fetal programming, leading to type 2 diabetes in later life.

  3. Liraglutide protects pancreatic beta cells during an early intervention in Gato-Kakizaki rats.

    Science.gov (United States)

    Luo, Xiu; Pan, Linlin; Nie, Aifang; Wang, Qidi; Gu, Yanyun; Li, Fengying; Zhang, Hongli; Li, Wenyi; Li, Xiaoying

    2013-12-01

    Glucagon-like peptide-1 (GLP-1) analogues have emerged as insulin secretagogues and are widely used in type 2 diabetic patients. GLP-1 analogues also demonstrate a promotion of beta cell proliferation and reduction of apoptosis in rodents. In the present study, we investigated the protection of pancreatic beta cells by early use (at the age of 2 weeks) of GLP-1 analogue, liraglutide in Gato-Kakizaki (GK) rats and explored the underlying mechanisms. The effects of liraglutide on glucose tolerance were evaluated by intraperitoneal glucose tolerance test (IPGTT) and insulin release tests (IRT). Ki67 and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) immunostaining, Western blots and real-time polymerase chain reaction were applied to evaluate cell proliferation, apoptosis and related gene expressions. Our results demonstrated that early use of liraglutide improved glucose tolerance during liraglutide treatment in GK rats. Liraglutide increased pancreatic insulin contents and markedly reduced beta cell apoptosis. Liraglutide also downregulated pro-apoptotic gene expressions and reduced intra-islet macrophage infiltration. This experiment reported for the first time that early use of liraglutide could protect beta cell failure in pre-diabetic GK rats through reduction of beta cell apoptosis and ameliorating islet inflammation. © 2013 Ruijin Hospital, Shanghai Jiaotong University School of Medicine and Wiley Publishing Asia Pty Ltd.

  4. Influence of the mycotoxins alpha- and beta-zearalenol and deoxynivalenol on the cell cycle of cultured porcine endometrial cells.

    Science.gov (United States)

    Tiemann, U; Viergutz, T; Jonas, L; Schneider, F

    2003-01-01

    The present study investigated the effects of the mycotoxins alpha-zearalenol (alpha-ZOL) and beta-zearalenol (beta-ZOL) at concentrations of 7.5, 15, and 30 microM, and deoxynivalenol (DON) at concentrations of 0.94, 1.88, and 3.76 microM on cell cycle distribution (propidium iodide, PI staining) in combination with the proliferating cell nuclear antigen (PCNA) by flow cytometry. The viability of porcine uterine cells was not impaired at 30 microM alpha-ZOL, whereas beta-ZOL at this concentration and 3.76 microM DON significantly decreased cell number. Some cells showed ultrastructural features of cell death indicated by swollen mitochondria, disrupted cell membranes, and many vacuoles. After 24 and 48h of exposure to alpha-ZOL (7.5, 15, or 30 microM), the cell cycle distribution was still comparable to the control groups. An anti-proliferative effect of beta-ZOL and DON was detected by a significant reduction in the S-phase together with arrest of cells in the G(0)/G(1)-phase. The results show that beta-ZOL (7.5, 15, or 30 microM) and DON (0.94, 1.88, or 3.76 microM) control the progression of cells through the cycle by decreasing S-phase and arresting cells in the G(0)/G(1)-phase of the cell cycle. A significant decrease in the expression of the proliferation marker PCNA amounts indicates that beta-ZOL and DON disengaged cells from active cycling. We confirm that alpha-ZOL possesses a relative binding affinity to porcine uterine cytoplasmic estrogen receptor.

  5. AICA-riboside induces apoptosis of pancreatic beta cells through stimulation of AMP-activated protein kinase.

    Science.gov (United States)

    Kefas, B A; Heimberg, H; Vaulont, S; Meisse, D; Hue, L; Pipeleers, D; Van de Casteele, M

    2003-02-01

    Prolonged exposure of beta cells to low glucose concentrations triggers their apoptosis and is known to activate AMP-activated protein kinase (AMPK) in beta cell lines. We examined whether prolonged activation of AMPK can trigger apoptosis in rodent beta cells. Primary beta cells were FACS-purified from rats, and from wild-type and AMPK(alpha2)-deficient mice. AMPK activation in beta cells was induced by the adenosine analog AICA-riboside and detected by immunoblotting using a phosphospecific antibody. Apoptosis of rodent beta cells was monitored by FACS analysis of beta cell DNA content, by direct counting of apoptotic cells using fluorescence microscopy, or by measurement of their caspase-3 activity. Dose-dependent and time-dependent apoptosis of the cells, concommittant with an activation of caspase-3, were suppressed by the caspase inhibitors zVAD-fmk and zDEVD-fmk. Apoptosis induction by AICA-riboside was also prevented by adding the MAPK-inhibitor SB203580 which blocked the AICA-riboside-induced phosphorylation of AMPK. Beta cells isolated from AMPK-(alpha2)-deficient mice were resistant against AICA-riboside induced apoptosis. Sustained activation of AMPK by AICA-riboside can trigger a caspase-dependent apoptosis of pancreatic beta cells.

  6. Cyclodextrin-facilitated bioconversion of 17 beta-estradiol by a phenoloxidase from Mucuna pruriens cell cultures

    NARCIS (Netherlands)

    Woerdenbag, H.J.; Pras, N.; Frijlink, H.W.; Lerk, C.F.; Malingré, T.M.

    1990-01-01

    After complexation with beta-cyclodextrin, the phenolic steroid 17 beta-estradiol could be ortho-hydroxylated into a catechol, mainly 4-hydroxyestradiol, by a phenoloxidase from in vitro grown cells of Mucuna pruriens. By complexation with beta-cyclodextrin the solubility of the steroid increased

  7. Differential effects of BMP-2 and TGF-beta1 on chondrogenic differentiation of adipose derived stem cells

    DEFF Research Database (Denmark)

    Mehlhorn, A T; Niemeyer, P; Kaschte, K

    2007-01-01

    OBJECTIVES: This article addresses the interaction of transforming growth factor beta1 (TGF-beta1) and bone morphogenic protein 2 (BMP-2) during osteo-chondrogenic differentiation of adipose-derived adult stem cells (ASC). TGF-beta1 was expected to modulate the BMP-2-induced effects through...

  8. Obesity Suppresses Estrogen Receptor Beta Expression in Breast Cancer Cells via a HER2-Mediated Pathway.

    Science.gov (United States)

    Bowers, Laura W; Wiese, Megan; Brenner, Andrew J; Rossi, Emily L; Tekmal, Rajeshwar R; Hursting, Stephen D; deGraffenried, Linda A

    2015-01-01

    Obesity is associated with a worse breast cancer prognosis, while greater breast tumor estrogen receptor beta (ERβ) expression is correlated with improved therapy response and survival. The objective of this study was to determine the impact of obesity on breast cancer cell ERβ expression, which is currently unknown. We utilized an in vitro model of obesity in which breast cancer cells were exposed to patient serum pooled by body mass index category (obese (OB): ≥30 kg/m2; normal weight (N): 18.5-24.9 kg/m2). Four human mammary tumor cell lines representing the major breast cancer subtypes (SKBR3, MCF-7, ZR75, MDA-MB-231) and mammary tumor cells from MMTV-neu mice were used. ERβ expression, assessed by qPCR and western blotting, was suppressed in the two HER2-overexpressing cell lines (SKBR3, MMTV-neu) following OB versus N sera exposure, but did not vary in the other cell lines. Expression of Bcl-2 and cyclin D1, two genes negatively regulated by ERβ, was elevated in SKBR3 cells following exposure to OB versus N sera, but this difference was eliminated when the ERβ gene was silenced with siRNA. Herceptin, a HER2 antagonist, and siRNA to HER2 were used to evaluate the role of HER2 in sera-induced ERβ modulation. SKBR3 cell treatment with OB sera plus Herceptin increased ERβ expression three-fold. Similar results were obtained when HER2 expression was silenced with siRNA. OB sera also promoted greater SKBR3 cell viability and growth, but this variance was not present when ERβ was silenced or the cells were modified to overexpress ERβ. Based on this data, we conclude that obesity-associated systemic factors suppress ERβ expression in breast cancer cells via a HER2-mediated pathway, leading to greater cell viability and growth. Elucidation of the mechanism(s) mediating this effect could provide important insights into how ERβ expression is regulated as well as how obesity promotes a more aggressive disease.

  9. Obesity Suppresses Estrogen Receptor Beta Expression in Breast Cancer Cells via a HER2-Mediated Pathway.

    Directory of Open Access Journals (Sweden)

    Laura W Bowers

    Full Text Available Obesity is associated with a worse breast cancer prognosis, while greater breast tumor estrogen receptor beta (ERβ expression is correlated with improved therapy response and survival. The objective of this study was to determine the impact of obesity on breast cancer cell ERβ expression, which is currently unknown. We utilized an in vitro model of obesity in which breast cancer cells were exposed to patient serum pooled by body mass index category (obese (OB: ≥30 kg/m2; normal weight (N: 18.5-24.9 kg/m2. Four human mammary tumor cell lines representing the major breast cancer subtypes (SKBR3, MCF-7, ZR75, MDA-MB-231 and mammary tumor cells from MMTV-neu mice were used. ERβ expression, assessed by qPCR and western blotting, was suppressed in the two HER2-overexpressing cell lines (SKBR3, MMTV-neu following OB versus N sera exposure, but did not vary in the other cell lines. Expression of Bcl-2 and cyclin D1, two genes negatively regulated by ERβ, was elevated in SKBR3 cells following exposure to OB versus N sera, but this difference was eliminated when the ERβ gene was silenced with siRNA. Herceptin, a HER2 antagonist, and siRNA to HER2 were used to evaluate the role of HER2 in sera-induced ERβ modulation. SKBR3 cell treatment with OB sera plus Herceptin increased ERβ expression three-fold. Similar results were obtained when HER2 expression was silenced with siRNA. OB sera also promoted greater SKBR3 cell viability and growth, but this variance was not present when ERβ was silenced or the cells were modified to overexpress ERβ. Based on this data, we conclude that obesity-associated systemic factors suppress ERβ expression in breast cancer cells via a HER2-mediated pathway, leading to greater cell viability and growth. Elucidation of the mechanism(s mediating this effect could provide important insights into how ERβ expression is regulated as well as how obesity promotes a more aggressive disease.

  10. MiR-214 inhibits cell growth in hepatocellular carcinoma through suppression of {beta}-catenin

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xiaojun [Liver Diseases Center, The First Affiliated Hospital of Fujian Medical University, Fuzhou (China); Chen, Ji [Department of Gastrointestinal Surgery, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai (China); Li, Feng [Department of Pathology, Fujian Provincial Hospital, Fuzhou (China); Lin, Yanting [Liver Diseases Center, The First Affiliated Hospital of Fujian Medical University, Fuzhou (China); Zhang, Xiaoping; Lv, Zhongwei [Department of Interventional Therapy, Shanghai 10th People' s Hospital, School of Medicine, Tongji University, Shanghai (China); Jiang, Jiaji, E-mail: jiang_jjcn@yahoo.com.cn [Liver Diseases Center, The First Affiliated Hospital of Fujian Medical University, Fuzhou (China)

    2012-11-30

    Highlights: Black-Right-Pointing-Pointer miR-214 is frequently downregulated in human HCC cell lines and tissues. Black-Right-Pointing-Pointer miR-214 overexpression inhibits HCC cell growth in vitro and in vivo. Black-Right-Pointing-Pointer miR-214 directly targets {beta}-catenin 3 Prime -UTR in HCC cells. Black-Right-Pointing-Pointer miR-214 regulates {beta}-catenin downstream signaling molecules. -- Abstract: Mounting evidence has shown that microRNAs (miRNAs) are implicated in carcinogenesis and can function as oncogenes or tumor suppressor genes in human cancers. Recent profile studies of miRNA expression have documented a deregulation of miRNA (miR-214) in hepatocellular carcinoma (HCC). However, its potential functions and underlying mechanisms in hepatocarcinogenesis remain largely unknown. Here, we confirmed that miR-214 is significantly downregulated in HCC cells and specimens. Ectopic overexpression of miR-214 inhibited proliferation of HCC cells in vitro and tumorigenicity in vivo. Further studies revealed that miR-214 could directly target the 3 Prime -untranslated region (3 Prime -UTR) of {beta}-catenin mRNA and suppress its protein expression. Similar to the restoring miR-214 expression, {beta}-catenin downregulation inhibited cell growth, whereas restoring the {beta}-catenin expression abolished the function of miR-214. Moreover, miR-214-mediated reduction of {beta}-catenin resulted in suppression of several downstream genes including c-Myc, cyclinD1, TCF-1, and LEF-1. These findings indicate that miR-214 serves as tumor suppressor and plays substantial roles in inhibiting the tumorigenesis of HCC through suppression of {beta}-catenin. Given these, miR-214 may serve as a useful prognostic or therapeutic target for treatment of HCC.

  11. Mycophenolate mofetil modulates adhesion receptors of the beta1 integrin family on tumor cells: impact on tumor recurrence and malignancy

    International Nuclear Information System (INIS)

    Engl, Tobias; Makarević, Jasmina; Relja, Borna; Natsheh, Iyad; Müller, Iris; Beecken, Wolf-Dietrich; Jonas, Dietger; Blaheta, Roman A

    2005-01-01

    Tumor development remains one of the major obstacles following organ transplantation. Immunosuppressive drugs such as cyclosporine and tacrolimus directly contribute to enhanced malignancy, whereas the influence of the novel compound mycophenolate mofetil (MMF) on tumor cell dissemination has not been explored. We therefore investigated the adhesion capacity of colon, pancreas, prostate and kidney carcinoma cell lines to endothelium, as well as their beta1 integrin expression profile before and after MMF treatment. Tumor cell adhesion to endothelial cell monolayers was evaluated in the presence of 0.1 and 1 μM MMF and compared to unstimulated controls. beta1 integrin analysis included alpha1beta1 (CD49a), alpha2beta1 (CD49b), alpha3beta1 (CD49c), alpha4beta1 (CD49d), alpha5beta1 (CD49e), and alpha6beta1 (CD49f) receptors, and was carried out by reverse transcriptase-polymerase chain reaction, confocal microscopy and flow cytometry. Adhesion of the colon carcinoma cell line HT-29 was strongly reduced in the presence of 0.1 μM MMF. This effect was accompanied by down-regulation of alpha3beta1 and alpha6beta1 surface expression and of alpha3beta1 and alpha6beta1 coding mRNA. Adhesion of the prostate tumor cell line DU-145 was blocked dose-dependently by MMF. In contrast to MMF's effects on HT-29 cells, MMF dose-dependently up-regulated alpha1beta1, alpha2beta1, alpha3beta1, and alpha5beta1 on DU-145 tumor cell membranes. We conclude that MMF possesses distinct anti-tumoral properties, particularly in colon and prostate carcinoma cells. Adhesion blockage of HT-29 cells was due to the loss of alpha3beta1 and alpha6beta1 surface expression, which might contribute to a reduced invasive behaviour of this tumor entity. The enhancement of integrin beta1 subtypes observed in DU-145 cells possibly causes re-differentiation towards a low-invasive phenotype

  12. Mycophenolate mofetil modulates adhesion receptors of the beta1 integrin family on tumor cells: impact on tumor recurrence and malignancy

    Directory of Open Access Journals (Sweden)

    Beecken Wolf-Dietrich

    2005-01-01

    Full Text Available Abstract Background Tumor development remains one of the major obstacles following organ transplantation. Immunosuppressive drugs such as cyclosporine and tacrolimus directly contribute to enhanced malignancy, whereas the influence of the novel compound mycophenolate mofetil (MMF on tumor cell dissemination has not been explored. We therefore investigated the adhesion capacity of colon, pancreas, prostate and kidney carcinoma cell lines to endothelium, as well as their beta1 integrin expression profile before and after MMF treatment. Methods Tumor cell adhesion to endothelial cell monolayers was evaluated in the presence of 0.1 and 1 μM MMF and compared to unstimulated controls. beta1 integrin analysis included alpha1beta1 (CD49a, alpha2beta1 (CD49b, alpha3beta1 (CD49c, alpha4beta1 (CD49d, alpha5beta1 (CD49e, and alpha6beta1 (CD49f receptors, and was carried out by reverse transcriptase-polymerase chain reaction, confocal microscopy and flow cytometry. Results Adhesion of the colon carcinoma cell line HT-29 was strongly reduced in the presence of 0.1 μM MMF. This effect was accompanied by down-regulation of alpha3beta1 and alpha6beta1 surface expression and of alpha3beta1 and alpha6beta1 coding mRNA. Adhesion of the prostate tumor cell line DU-145 was blocked dose-dependently by MMF. In contrast to MMF's effects on HT-29 cells, MMF dose-dependently up-regulated alpha1beta1, alpha2beta1, alpha3beta1, and alpha5beta1 on DU-145 tumor cell membranes. Conclusion We conclude that MMF possesses distinct anti-tumoral properties, particularly in colon and prostate carcinoma cells. Adhesion blockage of HT-29 cells was due to the loss of alpha3beta1 and alpha6beta1 surface expression, which might contribute to a reduced invasive behaviour of this tumor entity. The enhancement of integrin beta1 subtypes observed in DU-145 cells possibly causes re-differentiation towards a low-invasive phenotype.

  13. Immunohistochemical detection for nuclear beta-catenin in sporadic basal cell carcinoma.

    Science.gov (United States)

    Yamazaki, F; Aragane, Y; Kawada, A; Tezuka, T

    2001-11-01

    Despite the increasing incidence of basal cell carcinoma (BCC), its pathogenesis has remained largely unknown. Recently, it was reported that genes involved in tissue morphogenesis, such as sonic hedgehog or patched, were found to be mutated in BCC, suggesting the involvement of those molecules in the pathogenesis of this tumour. Furthermore, there is evidence that the Wnt-mediated signalling pathway may be one of the downstream targets of sonic hedgehog-mediated signalling, which has led us to focus on molecular events on the Wnt pathway in BCC. Among the signal transducers involved in the Wnt pathway, it is clear that beta-catenin plays a pivotal role in the promotion of morphogenesis and cell growth. In respect to this, it has been reported that, in particular circumstances, as in colorectal cancers, beta-catenin migrates to the nuclei, where it exerts an ability to activate the transcription of various genes. To investigate the cellular distribution of beta-catenin in skin tumours, in particular, in BCC. Twenty skin biopsy specimens derived from BCC, 10 from inflammatory skin diseases and five from squamous cell carcinomas were immunostained with an antibody directed against beta-catenin. Fourteen of the 20 BCC samples tested showed nuclear localization of beta-catenin, while none of the other samples gave rise to positive nuclear staining. Nuclear localization of beta-catenin is a characteristic feature of BCC; this suggests its tumorigenic role in this tumour. This gives us a further insight into the molecular pathogenesis of BCC.

  14. Calcium has a permissive role in interleukin-1beta-induced c-jun N-terminal kinase activation in insulin-secreting cells

    DEFF Research Database (Denmark)

    Størling, Joachim; Zaitsev, Sergei V; Kapelioukh, Iouri L

    2005-01-01

    The c-jun N-terminal kinase (JNK) signaling pathway mediates IL-1beta-induced apoptosis in insulin-secreting cells, a mechanism relevant to the destruction of pancreatic beta-cells in type 1 and 2 diabetes. However, the mechanisms that contribute to IL-1beta activation of JNK in beta-cells are la...

  15. Empagliflozin Treatment is Associated with Improved Beta Cell Function in T2DM.

    Science.gov (United States)

    Al Jobori, Hussein; Daniele, Giuseppe; Adams, John; Cersosimo, Eugenio; Solis-Herrera, Carolina; Triplitt, Curtis; DeFronzo, Ralph A; Abdul-Ghani, Muhammad

    2018-01-12

    To examine whether lowering the plasma glucose concentration with empagliflozin (SGLT2 inhibitor) improves beta cell function in T2DM. 15 T2DM patients received empagliflozin (25 mg/day) for 2 weeks, and beta cell function was measured with 9-step hyperglycemic clamp (each step = +40 mg/dl) before and 48 hours and 14 days after empagliflozin. Empagliflozin caused 101±10 and 117±11 grams glucosuria on days 1 and 14 and produced 25±6 and 38±8 mg/dl reduction (pEmpagliflozin increased the incremental area under the plasma C-peptide concentration curve by 48±12% and 61±10% during the stepped hyperglycemic clamp performed 48 hours and 14 days, respectively (both p empagliflozin. Empagliflozin also caused an increase in the glucose infusion rate during the hyperglycemic clamp performed on days 3 and 14 compared to baseline by 15% and 16% (both pempagliflozin. Empagliflozin also enhanced beta cell glucose sensitivity during the hyperglycemic clamp by 42% and 54% after 48 hours and 14 days, respectively (both pempagliflozin in T2DM patients: (1) augments beta cell glucose sensitivity and (2) improves beta cell function (IS/IR index). Copyright © 2018 Endocrine Society

  16. New Therapeutic Approaches to Prevent or Delay Beta-Cell Failure in Diabetes

    Directory of Open Access Journals (Sweden)

    Ionica Floriana Elvira

    2015-09-01

    Full Text Available Background and aims: The most recent estimates of International Diabetes Federation indicate that 382 million people have diabetes, and the incidence of this disease is increasing. While in type 1 diabetes mellitus (T1DM beta-cell death is autoimmunemediated, type 2 diabetes mellitus (T2DM results from an interaction between genetic and environmental factors that impair beta-cell function and insulin action. Many people with T2DM remain unaware of their illness for a long time because symptoms may take years to appear or be recognized, while the body is affected by excess blood glucose. These patients are often diagnosed only when diabetes complications have already developed. The aim of this article was to perform a review based on literature data on therapeutic modalities to prevent/delay beta cell function decline. Material and Methods: We searched MEDLINE from 2000 to the present to identify the therapeutic approaches to prevent or delay beta-cell failure in patients with T2DM. Results and conclusions: Several common polymorphisms in genes linked to monogenic forms of diabetes appear to influence the response to T2DM pharmacotherapy. Recent studies report the role of the G protein coupled receptor 40 (GPR40, also known as Free Fatty Acids Receptor 1 (FFAR1 in the regulation of beta-cell function- CNX-011-67 (a GPR40 agonist has the potential to provide good and durable glycemic control in T2DM patients.

  17. High fat programming of beta cell compensation, exhaustion, death and dysfunction.

    Science.gov (United States)

    Cerf, Marlon E

    2015-03-01

    Programming refers to events during critical developmental windows that shape progeny health outcomes. Fetal programming refers to the effects of intrauterine (in utero) events. Lactational programming refers to the effects of events during suckling (weaning). Developmental programming refers to the effects of events during both fetal and lactational life. Postnatal programming refers to the effects of events either from birth (lactational life) to adolescence or from weaning (end of lactation) to adolescence. Islets are most plastic during the early life course; hence programming during fetal and lactational life is most potent. High fat (HF) programming is the maintenance on a HF diet (HFD) during critical developmental life stages that alters progeny metabolism and physiology. HF programming induces variable diabetogenic phenotypes dependent on the timing and duration of the dietary insult. Maternal obesity reinforces HF programming effects in progeny. HF programming, through acute hyperglycemia, initiates beta cell compensation. However, HF programming eventually leads to chronic hyperglycemia that triggers beta cell exhaustion, death and dysfunction. In HF programming, beta cell dysfunction often co-presents with insulin resistance. Balanced, healthy nutrition during developmental windows is critical for preserving beta cell structure and function. Thus early positive nutritional interventions that coincide with the development of beta cells may reduce the overwhelming burden of diabetes and metabolic disease. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  18. Beta-cell-tropin is associated with short-term stimulation of food intake in chicks.

    Science.gov (United States)

    Shipp, Steven L; Smith, Marissa L; Gilbert, Elizabeth R; Cline, Mark A

    2015-12-01

    Beta-cell-tropin, a peptide derived from adrenocorticotropic hormone, is an insulin secretagogue. When centrally injected, it increases food intake in rats, but its appetite-associated effects have not been reported in any other species. Thus, the present study was designed to evaluate the effects of central beta-cell-tropin on appetite-associated parameters in an alternative vertebrate model, the chick. Central injection of 2 or 4 nmol beta-cell-tropin increased food intake for 60 min. Whole hypothalamus was collected at 60 min post-injection, and real-time PCR performed to measure mRNA abundance of agouti-related peptide, corticotropin releasing factor, galanin, melanin concentrating hormone, neuropeptide Y, orexin, prohormone convertase 2, pro-opiomelanocortin, peroxisome proliferator-activated receptor γ, urotensin 2, and visfatin, not one of which were affected by beta-cell-tropin treatment. Results demonstrate that beta-cell-tropin is associated with short-term stimulation of food intake. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Mass, NMR and CD spectra of some chiral Schiff bases of beta-poly ketones

    International Nuclear Information System (INIS)

    Ahmad, R.; Ahmad, N.; Malik, M.A.; Zia-ul-Haq, M.

    1996-01-01

    Chiral Schiff bases R,R-trans-1,2-bis[3-imino-1-phenyl-1-butanone] Cyclohexane (I) and R,R-trans-1,2-bis[5-imino-1-phenyl-1,3-hexa dione] cyclohexane (II) have been synthesized and their mass, NMR and CD spectra are reported. A number of Schiff bases containing azomethine (C=N-) group have been obtained by condensation of primary amines with an active carbonyl group. These ligands form stable complexes with metal ions especially if the amine and/or the carbonyl compound contain a second functional group sufficiently close to the site of condensation capable of forming five or six membered chelates. In recent years chelates of quadridentate Schiff bases derived from condensation of two moles of 1,2-diketones of salicyladehyde with one mole of 1,2-diamine have been extensively investigated. Condensation of 1,3,5-tri ketones with 1,2 diamines yield the so called compartmental ligands capable of binding one or two metal ions in different compartments. A number of mono and bimetallic complexes of such ligands have been characterized and their spectral studies reported. Chiral Schiff bases may be obtained condensing optically pure diamines (such as 1,2 diamino propane, 2,3-diaminobutane of trans 1,2-diaminocychohexane) with beta poly ketones or salicylaldehyde. The circular dichroism (CD) studies of chelates of with some of these chiral quadridentate ligands have already been reported. However to our knowledge no Schiff bases derived from condensation of chiral diamines with any 1,3,5-tri ketones have been characterized and their chelates reported. In this paper, we wish to report synthesis, proton magnetic resonance, mass, UV, IR and CD spectral studies of Schiff bases R,R-trans-1,2-Bis[3-imino-1-phenyl-1-butanone] cyclohexane(I) and R,R-trans 1,2-bis[5-imino-1-phenyl-1,3-hexa dione] cyclohexane(II). The transition metal chelates of (II) and their CD spectral studies have been reported separately. (author)

  20. Sodium fluorocitrate having protective effect on palmitate-induced beta cell death improves hyperglycemia in diabetic db/db mice

    OpenAIRE

    Jung, Ik-Rak; Choi, Sung-E.; Hong, Seung A.; Hwang, Yoonjung; Kang, Yup

    2017-01-01

    Beta cell loss and insulin resistance play roles in the pathogenesis of type 2 diabetes. Elevated levels of free fatty acids in plasma might contribute to the loss of beta cells. The objective of this study was to find a chemical that could protect against palmitate-induced beta cell death and investigate whether such chemical could improve hyperglycemia in mouse model of type 2 diabetes. Sodium fluorocitrate (SFC), an aconitase inhibitor, was found to be strongly and specifically protective ...

  1. Zip4 mediated zinc influx stimulates insulin secretion in pancreatic beta cells.

    Directory of Open Access Journals (Sweden)

    Alexandre B Hardy

    Full Text Available Zinc has an important role in normal pancreatic beta cell physiology as it regulates gene transcription, insulin crystallization and secretion, and cell survival. Nevertheless, little is known about how zinc is transported through the plasma membrane of beta cells and which of the class of zinc influx transporters (Zip is involved. Zip4 was previously shown to be expressed in human and mouse beta cells; however, its function there is still unknown. Therefore, the aim of this study was to define the zinc transport role of Zip4 in beta cells. To investigate this, Zip4 was over-expressed in MIN6 beta cells using a pCMV6-Zip4GFP plasmid. Organelle staining combined with confocal microscopy showed that Zip4 exhibits a widespread localization in MIN6 cells. Time-lapse zinc imaging experiments showed that Zip4 increases cytoplasmic zinc levels. This resulted in increased granular zinc content and glucose-stimulated insulin secretion. Interestingly, it is unlikely that the increased glucose stimulated insulin secretion was triggered by a modulation of mitochondrial function, as mitochondrial membrane potential remained unchanged. To define the role of Zip4 in-vivo, we generated a beta cell-specific knockout mouse model (Zip4BKO. Deletion of the Zip4 gene was confirmed in Zip4BKO islets by PCR, RT-PCR, and immuno-histochemistry. Zip4BKO mice showed slightly improved glucose homeostasis but no change in insulin secretion during an oral glucose tolerance test. While Zip4 was not found to be essential for proper glucose homeostasis and insulin secretion in vivo in mice, this study also found that Zip4 mediates increases in cytoplasmic and granular zinc pools and stimulates glucose dependant insulin secretion in-vitro.

  2. GSK-3beta inhibition enhances sorafenib-induced apoptosis in melanoma cell lines.

    Science.gov (United States)

    Panka, David J; Cho, Daniel C; Atkins, Michael B; Mier, James W

    2008-01-11

    Glycogen synthase kinase-3beta (GSK-3beta) can participate in the induction of apoptosis or, alternatively, provide a survival signal that minimizes cellular injury. We previously demonstrated that the multikinase inhibitor sorafenib induces apoptosis in melanoma cell lines. In this report, we show that sorafenib activates GSK-3beta in multiple subcellular compartments and that this activation undermines the lethality of the drug. Pharmacologic inhibition and/or down-modulation of the kinase enhances sorafenib-induced apoptosis as determined by propidium iodide staining and by assessing the mitochondrial release of apoptosis-inducing factor and Smac/DIABLO. Conversely, the forced expression of a constitutively active form of the enzyme (GSK-3beta(S9A)) protects the cells from the apoptotic effects of the drug. This protective effect is associated with a marked increase in basal levels of Bcl-2, Bcl-x(L), and survivin and a diminution in the degree to which these anti-apoptotic proteins are down-modulated by sorafenib exposure. Sorafenib down-modulates the pro-apoptotic Bcl-2 family member Noxa in cells with high constitutive GSK-3beta activity. Pharmacologic inhibition of GSK-3beta prevents the disappearance of Noxa induced by sorafenib and enhances the down-modulation of Mcl-1. Down-modulation of Noxa largely eliminates the enhancing effect of GSK-3 inhibition on sorafenib-induced apoptosis. These data provide a strong rationale for the use of GSK-3beta inhibitors as adjuncts to sorafenib treatment and suggest that preservation of Noxa may contribute to their efficacy.

  3. The effect of suppressor of cytokine signaling 3 on GH signaling in beta-cells

    DEFF Research Database (Denmark)

    Rønn, Sif G; Hansen, Johnny A; Lindberg, Karen

    2002-01-01

    GH is an important regulator of cell growth and metabolism. In the pancreas, GH stimulates mitogenesis as well as insulin production in beta-cells. The cellular effects of GH are exerted mainly through activation of the Janus kinase-signal transducer and activator of transcription (STAT) pathway...

  4. Enhanced expression of beta2-microglobulin and HLA antigens on human lymphoid cells by interferon

    DEFF Research Database (Denmark)

    Heron, I; Hokland, M; Berg, K

    1979-01-01

    Mononuclear cells from the blood of healthy normal humans were kept in cultures under nonstimulating conditions for 16 hr in the presence or absence of human interferon. The relative quantities of HLA antigens and beta(2)-microglobulin on the cultured cells were determined by quantitative immunof...

  5. Transcriptional regulation of CD4 gene expression by T cell factor-1/beta-catenin pathway.

    NARCIS (Netherlands)

    Huang, Z.; Xie, H.; Ioannidis, V.; Held, W.; Clevers, J.C.; Sadim, M.S.; Sun, Z.

    2006-01-01

    By interacting with MHC class II molecules, CD4 facilitates lineage development as well as activation of Th cells. Expression of physiological levels of CD4 requires a proximal CD4 enhancer to stimulate basic CD4 promoter activity. T cell factor (TCF)-1/beta-catenin pathway has previously been shown

  6. Effects of putrescine, cadaverine, spermine, spermidine and beta-phenylethylamine on cultured bovine mammary epithelial cells

    DEFF Research Database (Denmark)

    Fusi, Eleonora; Baldi, Antonella; Cheli, Federica

    2008-01-01

    A bovine mammary epithelial cell line (BME-UV1) and three-dimensional collagen primary bovine organoids were used to evaluate the effects of cadaverine, putrescine, spermine, spermicline and beta-phenylethylamine on mammary epithelial cells. Each biogenic amine was diluted in several concentratio...

  7. Inactivation of the transforming growth factor beta type II receptor in human small cell lung cancer cell lines

    DEFF Research Database (Denmark)

    Hougaard, S; Nørgaard, P; Abrahamsen, N

    1999-01-01

    Transforming growth factor beta (TGF-beta) exerts a growth inhibitory effect on many cell types through binding to two types of receptors, the type I and II receptors. Resistance to TGF-beta due to lack of type II receptor (RII) has been described in some cancer types including small cell lung...... cancer (SCLC). The purpose of this study was to examine the cause of absent RII expression in SCLC cell lines. Northern blot analysis showed that RII RNA expression was very weak in 16 of 21 cell lines. To investigate if the absence of RII transcript was due to mutations, we screened the poly-A tract...... for mutations, but no mutations were detected. Additional screening for mutations of the RII gene revealed a GG to TT base substitution in one cell line, which did not express RII. This mutation generates a stop codon resulting in predicted synthesis of a truncated RII of 219 amino acids. The nature...

  8. Effects of ultrasound on Transforming Growth Factor-beta genes in bone cells

    Directory of Open Access Journals (Sweden)

    J Harle

    2005-12-01

    Full Text Available Therapeutic ultrasound (US is a widely used form of biophysical stimulation that is increasingly applied to promote fracture healing. Transforming growth factor-beta (TGF-beta, which is encoded by three related but different genes, is known to play a major part in bone growth and repair. However, the effects of US on the expression of the TGF-beta genes and the physical acoustic mechanisms involved in initiating changes in gene expression in vitro, are not yet known. The present study demonstrates that US had a differential effect on these TGF-beta isoforms in a human osteoblast cell line, with the highest dose eliciting the most pronounced up-regulation of both TGF-beta1 and TGF-beta3 at 1 hour after treatment and thereafter declining. In contrast, US had no effect on TGF-beta2 expression. Fluid streaming rather than thermal effects or cavitation was found to be the most likely explanation for the gene responses observed in vitro.

  9. Rac1-NADPH oxidase signaling promotes CD36 activation under glucotoxic conditions in pancreatic beta cells.

    Science.gov (United States)

    Elumalai, Suma; Karunakaran, Udayakumar; Lee, In Kyu; Moon, Jun Sung; Won, Kyu Chang

    2017-04-01

    We recently reported that cluster determinant 36 (CD36), a fatty acid transporter, plays a pivotal role in glucotoxicity-induced β-cell dysfunction. However, little is known about how glucotoxicity influences CD36 expression. Emerging evidence suggests that the small GTPase Rac1 is involved in the pathogenesis of beta cell dysfunction in type 2 diabetes (T2D). The primary objective of the current study was to determine the role of Rac1 in CD36 activation and its impact on β-cell dysfunction in diabetes mellitus. To address this question, we subjected INS-1 cells and human beta cells (1.1B4) to high glucose conditions (30mM) in the presence or absence of Rac1 inhibition either by NSC23766 (Rac1 GTPase inhibitor) or small interfering RNA. High glucose exposure in INS-1 and human beta cells (1.1b4) resulted in the activation of Rac1 and induced cell apoptosis. Rac1 activation mediates NADPH oxidase (NOX) activation leading to elevated ROS production in both cells. Activation of the Rac1-NOX complex by high glucose levels enhanced CD36 expression in INS-1 and human 1.1b4 beta cell membrane fractions. The inhibition of Rac1 by NSC23766 inhibited NADPH oxidase activity and ROS generation induced by high glucose concentrations in INS-1 & human 1.1b4 beta cells. Inhibition of Rac1-NOX complex activation by NSC23766 significantly reduced CD36 expression in INS-1 and human 1.1b4 beta cell membrane fractions. In addition, Rac1 inhibition by NSC23766 significantly reduced high glucose-induced mitochondrial dysfunction. Furthermore, NADPH oxidase inhibition by VAS2870 also attenuated high glucose-induced ROS generation and cell apoptosis. These results suggest that Rac1-NADPH oxidase dependent CD36 expression contributes to high glucose-induced beta cell dysfunction and cell death. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  10. TGF{beta} induces proHB-EGF shedding and EGFR transactivation through ADAM activation in gastric cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Ebi, Masahide [Department of Gastroenterology and Metabolism, Nagoya City University Graduate School of Medical Sciences, Nagoya (Japan); Kataoka, Hiromi, E-mail: hkataoka@med.nagoya-cu.ac.jp [Department of Gastroenterology and Metabolism, Nagoya City University Graduate School of Medical Sciences, Nagoya (Japan); Shimura, Takaya; Kubota, Eiji; Hirata, Yoshikazu; Mizushima, Takashi; Mizoshita, Tsutomu; Tanaka, Mamoru; Mabuchi, Motoshi; Tsukamoto, Hironobu; Tanida, Satoshi; Kamiya, Takeshi [Department of Gastroenterology and Metabolism, Nagoya City University Graduate School of Medical Sciences, Nagoya (Japan); Higashiyama, Shigeki [Department of Biochemistry and Molecular Genetics, Ehime University Graduate School of Medicine, Ehime (Japan); Joh, Takashi [Department of Gastroenterology and Metabolism, Nagoya City University Graduate School of Medical Sciences, Nagoya (Japan)

    2010-11-19

    Research highlights: {yields} TGF{beta} induces EGFR transactivation through proHB-EGF shedding by activated ADAM members in gastric cancer cells. {yields} TGF{beta} induces nuclear translocation of HB-EGF-CTF cleaved by ADAM members. {yields} TGF{beta} enhances cell growth by EGFR transactivation and HB-EGF-CTF nuclear translocation and ADAM inhibitors block these effects. {yields} Silencing of ADAM17 also blocks EGFR transactivation, HB-EGF-CTF nuclear translocation and cancer cell growth by TGF{beta}. {yields} ADAM17 may play a crucial role in this TGF{beta}-HB-EGF signal transduction. -- Abstract: Background and aims: Transforming growth factor-beta (TGF{beta}) is known to potently inhibit cell growth. Loss of responsiveness to TGF{beta} inhibition on cell growth is a hallmark of many types of cancer, yet its mechanism is not fully understood. Membrane-anchored heparin-binding EGF-like growth factor (proHB-EGF) ectodomain is cleaved by a disintegrin and metalloproteinase (ADAM) members and is implicated in epidermal growth factor receptor (EGFR) transactivation. Recently, nuclear translocation of the C-terminal fragment (CTF) of pro-HB-EGF was found to induce cell growth. We investigated the association between TGF{beta} and HB-EGF signal transduction via ADAM activation. Materials and methods: The CCK-8 assay in two gastric cancer cell lines was used to determine the effect for cell growth by TGF{beta}. The effect of two ADAM inhibitors was also evaluated. Induction of EGFR phosphorylation by TGF{beta} was analyzed and the effect of the ADAM inhibitors was also examined. Nuclear translocation of HB-EGF-CTF by shedding through ADAM activated by TGF{beta} was also analyzed. EGFR transactivation, HB-EGF-CTF nuclear translocation, and cell growth were examined under the condition of ADAM17 knockdown. Result: TGF{beta}-induced EGFR phosphorylation of which ADAM inhibitors were able to inhibit. TGF{beta} induced shedding of proHB-EGF allowing HB-EGF-CTF to

  11. Calculation of absorbed dose of anchorage-dependent cells from internal beta-rays irradiation

    International Nuclear Information System (INIS)

    Chen Jianwei; Huang Gang; Li Shijun

    2001-01-01

    Objective: To elicit the formula of internal dosimetry in anchorage-dependent cells by beta-emitting radionuclides from uniformly distributed volume sources. Methods: By means of the definition of absorbed dose and the MIRD (Medical International Radiation Dose) scheme the formula of internal dosimetry was reasonably deduced. Firstly, studying the systems of suspension culture cells. Then, taking account of the speciality of the systems of the anchorage-dependent cells and the directions of irradiation, the absorbed dose of anchorage -dependent cells was calculated by the accumulated radioactivity, beta-ray energy, and the volume of the cultured systems. Results: The formula of internal dosimetry of suspension culture cells and anchorage-dependent cells were achieved. At the same time, the formula of internal dosimetry of suspension culture cells was compared with that of MIRD and was confirmed accurate. Conclusion: The formula of internal dosimetry is concise, reliable and accurate

  12. Distinct roles for dystroglycan, beta1 integrin and perlecan in cell surface laminin organization

    DEFF Research Database (Denmark)

    Henry, M D; Satz, J S; Brakebusch, C

    2001-01-01

    . Here we show that DG-mediated laminin clustering on mouse embryonic stem (ES) cells is a dynamic process in which clusters are consolidated over time into increasingly more complex structures. Utilizing various null-mutant ES cell lines, we define roles for other molecules in this process. In beta1...... integrin-deficient ES cells, laminin-1 binds to the cell surface, but fails to organize into more morphologically complex structures. This result indicates that beta1 integrin function is required after DG function in the cell surface-mediated laminin assembly process. In perlecan-deficient ES cells......, the formation of complex laminin-1 structures is defective, implicating perlecan in the laminin matrix assembly process. Moreover, laminin and perlecan reciprocally modulate the organization of the other on the cell surface. Taken together, the data support a model whereby DG serves as a receptor essential...

  13. Extending two Higgs doublet models for two-loop neutrino mass generation and one-loop neutrinoless double beta decay

    Directory of Open Access Journals (Sweden)

    Zhen Liu

    2017-02-01

    Full Text Available We extend some two Higgs doublet models, where the Yukawa couplings for the charged fermion mass generation only involve one Higgs doublet, by two singlet scalars respectively carrying a singly electric charge and a doubly electric charge. The doublet and singlet scalars together can mediate a two-loop diagram to generate a tiny Majorana mass matrix of the standard model neutrinos. Remarkably, the structure of the neutrino mass matrix is fully determined by the symmetric Yukawa couplings of the doubly charged scalar to the right-handed leptons. Meanwhile, a one-loop induced neutrinoless double beta decay can arrive at a testable level even if the electron neutrino has an extremely small Majorana mass. We also study other experimental constraints and implications including some rare processes and Higgs phenomenology.

  14. Determination of Insulin Resistance and Beta Cell Function in Healthy Obese and Non-obese Individuals

    International Nuclear Information System (INIS)

    Kazmi, A.; Sattar, A.; Tariq, K. M.; Najamussahar; Hashim, R.; Almani, M. I.

    2013-01-01

    Objective: To determine insulin resistance and beta cell function in healthy obese and nonobese individuals of the local population. Study Design: Case control study. Place and Duration of Study: AFIP Rawalpindi in collaboration with department of medicine military hospital(MH) Rawalpindi, from Aug 2008 to Mar 2009. Methods: Eighty obese(n=40) and non-obese(n=40) subjects were selected by non-probability convenience sampling. Plasma insulin, glucose, and serum total cholestrol were estimated in fasting state. Insulin resistance was calculated by HOMA-IR and beta cell function by HOMA- equation. Results: Significant differences were observed between obese and non-obese individuals regarding insulin resistance, beta cell function, and BMI and serum total cholesterol. Mean insulin resistance in obese group was found to be 11.1 +- 5.1(range 7.0-16.2) and in non-obese group it was 0.9+-0.4 (range 0.5-1.3). This difference was highly significant (p=0.001). There was a highly significant difference between the two groups in term of beta cell function with mean rank 60.1 for obese group and 20.9 non obese groups (Asym sig. 2 tailed 0.000). Also the correlation (r = 0.064) between insulin resistance and beta cell function in obese group is highly significant (p = 0.000). Mean serum leptin levels were lower (6.3 ng/ml) in non-obese, and high (57.2 ng/ml) in the obese group. Conclusions: Insulin resistance is found higher in obese individuals. Beta cell function is significantly different between obese and non-obese groups. (author)

  15. Increased replication of T-cell-tropic HIV strains and CXC-chemokine receptor-4 induction in T cells treated with macrophage inflammatory protein (MIP)-1alpha, MIP-1beta and RANTES beta-chemokines.

    Science.gov (United States)

    Dolei, A; Biolchini, A; Serra, C; Curreli, S; Gomes, E; Dianzani, F

    1998-01-22

    To study, in T-lymphoid cells, the effects of macrophage inflammatory protein (MIP)-1alpha, MIP-1beta and RANTES beta-chemokines on the replication of T-cell-tropic HIV-1 strains, since it has been reported that beta-chemokines interfere with the replication of macrophage-tropic HIV-1 strains, but not T-cell-tropic strains. Freshly phytohaemagglutinin (PHA)-activated peripheral blood lymphocytes (PBL) and cultured PHA-activated T cells from healthy volunteers, as well as the C8166 T-cell line, were treated overnight with beta-chemokines before infection with T-cell-tropic HIV-1 isolates, or human T-lymphotropic virus type IIIB. HIV replication was followed by detecting the production of infectious particles, p24 antigen, and viral sequences. CXC-chemokine receptor (CXCR)-4 expression was followed by detection and quantification of specific transcripts. Pretreatment of T cells with MIP-1alpha, MIP-1beta and RANTES affected T-cell-tropic strains, increased the replication of HIV-1beta and HIV-1RPdT strains dose-dependently, as well as virus absorption and provirus DNA accumulation. These findings were associated with increased accumulation of CXCR-4 transcripts, and mediated by the protein tyrosine kinase signalling. Moreover, beta-chemokines stimulated PBL proliferation. Beta-chemokines increase the adsorption and replication of at least some T-cell-tropic HIV-1 strains, and this is related to stimulated expression of the CXCR-4 coreceptor.

  16. Beta-globin gene cluster haplotypes and alpha-thalassemia in sickle cell disease patients from Trinidad.

    Science.gov (United States)

    Jones-Lecointe, Altheia; Smith, Erskine; Romana, Marc; Gilbert, Marie-Georges; Charles, Waveney P; Saint-Martin, Christian; Kéclard, Lisiane

    2008-01-01

    In this study, we have determined the frequency of beta(S) haplotypes in 163 sickle cell disease patients from Trinidad. The alpha(3.7) globin gene deletion status was also studied with an observed gene frequency of 0.17. Among the 283 beta(S) chromosomes analyzed, the Benin haplotype was the most prevalent (61.8%) followed by Bantu (17.3%), Senegal (8.5%), Cameroon (3.5%), and Arab-Indian (3.2%), while 5.7% of them were atypical. This beta(S) haplotypes distribution differed from those previously described in other Caribbean islands (Jamaica, Guadeloupe, and Cuba), in agreement with the known involvement of the major colonial powers (Spain, France, and Great Britain) in the slave trade in Trinidad and documented an Indian origin of the beta(S) gene.

  17. Mathematical Beta Cell Model for Insulin Secretion following IVGTT and OGTT

    DEFF Research Database (Denmark)

    Madsen, Henrik; Henriksen, Jan Erik; Karlsson, Mats

    2006-01-01

    Evaluation of beta cell function is conducted by a variety of glucose tolerance tests and evaluated by a number of different models with less than perfect consistency among results obtained from different tests. We formulated a new approximation of the distributed threshold model for insulin...... secretion in order to approach a model for quantifying beta cell function, not only for one, but for several different experiments. Data was obtained from 40 subjects that had both an oral glucose tolerance test (OGTT) and an intravenous tolerance test (IVGTT) performed. Parameter estimates from the two...

  18. Nuclear accumulation of beta-catenin occurs commonly in the epithelial cells of juvenile polyps.

    Science.gov (United States)

    Iwamoto, Michiko; Hoffenberg, Edward J; Carethers, John M; Doctolero, Ryan; Tajima, Akihiro; Sugano, Kentaro; Franklin, Wilbur A; Ahnen, Dennis J

    2005-01-01

    In the two conditions juvenile polyps (JPs) and juvenile polyposis coli (JPC), colonic polyps may have overlapping histologic and phenotypic appearance, but JPC confers a significant risk for colon adenocarcinoma. Although not thought to contain adenomatous polyposis coli (APC) mutations, the status of beta-catenin and full-length APC protein expression in JPs is not known. We evaluated beta-catenin and full-length APC protein expression in JPs from children with JPs and JPC. Cases were identified through endoscopic procedure records. Immunohistochemistry was performed for beta-catenin and full-length APC protein. Loss of heterozygosity at the APC gene locus on chromosome 5 was assessed using two APC-linked microsatellite markers. Polyp and normal colonic tissue were analyzed from 36 children with JPs and 9 with JPC. Both APC and beta-catenin immunoreactivity were present in epithelial cells from all samples but in different patterns. In all normal colon and polyp samples, APC expression was cytoplasmic with maximal immunoreactivity in the goblet cells. In contrast, beta-catenin immunoreactivity in epithelial cells was limited to the plasma membrane in normal colon but was both cytoplasmic and nuclear in all 45 JPs. No evidence of APC gene loss of heterozygosity was found. In polyps from children with JPs and JPC, nuclear beta-catenin accumulation is a consistent feature, and it is not due to APC gene mutation or loss of full-length APC protein expression. Thus, beta-catenin accumulation may be intrinsic to the formation of juvenile-type polyps through an as-yet-undefined mechanism.

  19. Cytotoxicity effects induced by Zearalenone metabolites, alpha Zearalenol and beta Zearalenol, on cultured Vero cells.

    Science.gov (United States)

    Othmen, Zouhour Ouanes-Ben; Golli, Emna El; Abid-Essefi, Salwa; Bacha, Hassen

    2008-10-30

    Zearalenone (Zen) is a non-steroidal estrogenic mycotoxin produced by several species of Fusarium. It has been implicated in several mycotoxicosis in farm animals and in humans. The major metabolites of this mycotoxin in various species are alpha and beta Zearalenol. In vivo, Zen is mainly reduced to these alcoholic metabolites which cause reproductive tract disorders and impaired fertility due to their estrogenic activities. In this study, we examined the cytotoxicity of alpha and beta Zearalenol in cultured cells. For this purpose, the MTT assay was carried out and the influence of alpha and beta Zearalenol on protein and DNA syntheses was assessed. To evaluate the cell stress caused by these two metabolites, oxidative stress measured by MDA induction and stress protein induction (Hsp 70, Hsp 27) were tested. Results showed that alpha and beta Zearalenol were metabolites that caused cytotoxicity by inhibiting cell viability, protein and DNA syntheses and inducing oxidative damage and over-expression of stress proteins. However, the Zen metabolites exhibited lower toxicity than Zen, with beta zearalenol being the more active of the two metabolites.

  20. An Abbreviated Protocol for In Vitro Generation of Functional Human Embryonic Stem Cell-Derived Beta-Like Cells

    DEFF Research Database (Denmark)

    Massumi, Mohammad; Pourasgari, Farzaneh; Nalla, Amarnadh

    2016-01-01

    developed an abbreviated five-stage protocol (25-30 days) to generate human Embryonic Stem Cell-Derived Beta-like Cells (ES-DBCs). We showed that Geltrex, as an extracellular matrix, could support the generation of ES-DBCs more efficiently than that of the previously described culture systems...

  1. In vitro and in vivo evaluation of insulin-producing beta TC6-F7 cells in microcapsules.

    Science.gov (United States)

    Zhou, D; Sun, A M; Li, X; Mamujee, S N; Vacek, I; Georgiou, J; Wheeler, M B

    1998-05-01

    In the present study, the insulin secretory capacity of beta TC6-F7 cells in microcapsules was evaluated. The cell mass within capsules was found to expand in a three-dimensional fashion, in contrast to cells seeded on plates that grew as a monolayer. In in vitro studies, both free and encapsulated cells were found to secrete insulin in the absence of glucose, at 13.6 +/- 1.1 and 14.5 +/- 0.9 ng.10(6) cells-1.60 min-1, respectively, with the response rising to a maximum of 26.0 +/- 0.8 and 31 +/- 2.3 ng.10(6) cells-1.60 min-1 in the presence of 16.8 mM glucose. Encapsulated cells were able to produce Ca2+ responses in the presence of KCl (50 mM) and BAY K 8644 (100 microM). In in vivo studies, intraperitoneal transplantation of 3.0 x 10(6) microencapsulated cells into mice (n = 5) with streptozotocin-induced diabetes resulted in the restoration of normoglycemia up to 57 days. Insulin concentrations rose from 0.4 +/- 0.1 ng/ml before the graft administration to 2.2 +/- 0.8 ng/ml after the transplantation in the normoglycemic recipients. An oral glucose challenge in transplant recipients demonstrated a flat glucose response, suggesting extremely high glucose clearance rates. These data demonstrate the potential use of the immunoisolated beta-cell lines for the treatment of diabetes.

  2. Evaluation of immunoisolated insulin-secreting beta TC6-F7 cells as a bioartificial pancreas.

    Science.gov (United States)

    Mamujee, S N; Zhou, D; Wheeler, M B; Vacek, I; Sun, A M

    1997-01-01

    To evaluate the growth and insulin secretion from microencapsulated beta TC6-F7 cells in vitro and to assess the in vivo function of microencapsulated cells transplanted in rats with steptozotocin (STZ)-induced diabetes. Alginate-poly-L-lysine encapsulated beta TC6-F7 cells were exposed to glucose, isobutylmethylxanthine (IBMX) and glucagon-like peptide I (7-36 amide) in a static in vitro challenge. In vivo, 2.5-3.5 x 10(7) encapsulated cells were implanted into diabetic rats. Graft function was evaluated by monitoring blood glucose concentrations and by an intraperitoneal glucose tolerance test. The cell density (number of cells per capsule) of cultured microencapsulated beta TC6-F7 cells increased almost 35-fold over a 55 day observation period to reach a plateau of approximately 3500 cells/capsule. While insulin secretion per capsule remained unchanged over the first 21 days of culture, a 7-fold increase was observed during the last 14 days of the 55 day observation period. Intraperitoneal transplantation of 3.5 x 10(7) encapsulated cells into diabetic rats resulted, within 24 hours, in reversal of hyperglycemia for up to 60 days. Post-transplantation blood glucose concentrations varied between 2 and 4 mM. Glucose clearance rates evaluated by an intraperitoneal glucose tolerance test at 30 days post-transplantation resulted in a markedly flat glucose clearance curve with blood glucose never rising above 4 mM. The glucose challenge of microencapsulated cells recovered 30 days post-transplantation resulted in a 2-fold increase in insulin response at glucose concentrations greater than 5.5 mM as compared to glucose-free media. In addition, immunostaining of recovered grafted tissue for insulin, reveals a strong presence of the peptide within the cell population. These data demonstrate the potential use of an immunoisolated beta-cell line for the treatment of diabetes.

  3. Distinct roles for dystroglycan, beta1 integrin and perlecan in cell surface laminin organization

    DEFF Research Database (Denmark)

    Henry, M D; Satz, J S; Brakebusch, C

    2001-01-01

    integrin-deficient ES cells, laminin-1 binds to the cell surface, but fails to organize into more morphologically complex structures. This result indicates that beta1 integrin function is required after DG function in the cell surface-mediated laminin assembly process. In perlecan-deficient ES cells......Dystroglycan (DG) is a cell surface receptor for several extracellular matrix (ECM) molecules including laminins, agrin and perlecan. Recent data indicate that DG function is required for the formation of basement membranes in early development and the organization of laminin on the cell surface...

  4. Use of antibodies against the variable regions of the T-cell receptor alpha/beta heterodimer for the study of cutaneous T-cell lymphomas.

    Science.gov (United States)

    Ralfkiaer, E; Wollf-Sneedorff, A; Vejlsgaard, G L

    1991-11-01

    Recent studies have suggested that antibodies against the variable (V) regions of the T-cell antigen receptor (TCR) may be used as markers for clonality and malignancy in T-cell infiltrates. We have investigated this by examining biopsy samples from 45 patients with cutaneous T-cell lymphomas (CTCL) for reactivity with seven antibodies against different V-gene families on the TCR alpha/beta heterodimer, i.e. ICI (V beta 5a), W112 (V beta 5b), OT145 (V beta 6a), 16G8 (V beta 8a), S511 (V beta 12a), F1 (V alpha 2a) and LC4 (alpha beta Va). Serial biopsies were available in 13 patients and a total of 62 samples were studied. The neoplastic cells in five cases were positive for either V beta 5 (one case), V beta 6 (one case), V beta 8 (two cases) or V beta 12 (one case). In the remaining 40 cases, no staining was seen of the neoplastic cells. These findings indicate that while antibodies against the TCR V-regions may be used as clonotypic markers for certain T-cell neoplasms, there is as yet not a sufficient number of anti-TCR V-region antibodies available for the routine diagnosis of these conditions.

  5. Alpha 4 beta 1 and alpha 5 beta 1 are differentially expressed during myelopoiesis and mediate the adherence of human CD34+ cells to fibronectin in an activation-dependent way

    NARCIS (Netherlands)

    Kerst, J. M.; Sanders, J. B.; Slaper-Cortenbach, I. C.; Doorakkers, M. C.; Hooibrink, B.; van Oers, R. H.; von dem Borne, A. E.; van der Schoot, C. E.

    1993-01-01

    To study the receptors involved in the interaction between extracellular matrix proteins and hematopoietic progenitor cells, we analyzed the expression of beta 1 integrins on CD34+ bone marrow cells by means of immunoflowcytometry. Alpha 4 beta 1 and alpha 5 beta 1 were expressed, whereas alpha 1

  6. Applied Developmental Biology: Making Human Pancreatic Beta Cells for Diabetics.

    Science.gov (United States)

    Melton, Douglas A

    2016-01-01

    Understanding the genes and signaling pathways that determine the differentiation and fate of a cell is a central goal of developmental biology. Using that information to gain mastery over the fates of cells presents new approaches to cell transplantation and drug discovery for human diseases including diabetes. © 2016 Elsevier Inc. All rights reserved.

  7. Beta cell 5'-shifted isomiRs are candidate regulatory hubs in type 2 diabetes.

    Directory of Open Access Journals (Sweden)

    Jeanette Baran-Gale

    Full Text Available Next-generation deep sequencing of small RNAs has unveiled the complexity of the microRNA (miRNA transcriptome, which is in large part due to the diversity of miRNA sequence variants ("isomiRs". Changes to a miRNA's seed sequence (nucleotides 2-8, including shifted start positions, can redirect targeting to a dramatically different set of RNAs and alter biological function. We performed deep sequencing of small RNA from mouse insulinoma (MIN6 cells (widely used as a surrogate for the study of pancreatic beta cells and developed a bioinformatic analysis pipeline to profile isomiR diversity. Additionally, we applied the pipeline to recently published small RNA-seq data from primary human beta cells and whole islets and compared the miRNA profiles with that of MIN6. We found that: (1 the miRNA expression profile in MIN6 cells is highly correlated with those of primary human beta cells and whole islets; (2 miRNA loci can generate multiple highly expressed isomiRs with different 5'-start positions (5'-isomiRs; (3 isomiRs with shifted start positions (5'-shifted isomiRs are highly expressed, and can be as abundant as their unshifted counterparts (5'-reference miRNAs. Finally, we identified 10 beta cell miRNA families as candidate regulatory hubs in a type 2 diabetes (T2D gene network. The most significant candidate hub was miR-29, which we demonstrated regulates the mRNA levels of several genes critical to beta cell function and implicated in T2D. Three of the candidate miRNA hubs were novel 5'-shifted isomiRs: miR-375+1, miR-375-1 and miR-183-5p+1. We showed by in silico target prediction and in vitro transfection studies that both miR-375+1 and miR-375-1 are likely to target an overlapping, but distinct suite of beta cell genes compared to canonical miR-375. In summary, this study characterizes the isomiR profile in beta cells for the first time, and also highlights the potential functional relevance of 5'-shifted isomiRs to T2D.

  8. Use of RNA interference to inhibit integrin (alpha6beta4)-mediated invasion and migration of breast carcinoma cells.

    Science.gov (United States)

    Lipscomb, Elizabeth A; Dugan, Aisling S; Rabinovitz, Isaac; Mercurio, Arthur M

    2003-01-01

    The application of small interfering RNA (siRNA) oligonucleotides to silence gene expression has profound implications for the intervention of human diseases including cancer. Using this technique, we explored the possibility that the alpha6beta4 integrin, a laminin adhesion receptor with a recognized role in the invasive phenotype of many carcinomas, represents a potential therapeutic target to inhibit the migration and invasion of carcinoma cells. We found that siRNA oligonucleotides targeted to either subunit of the alpha6beta4 integrin reduced cell surface expression of this integrin and resulted in decreased invasion of MDA-MB-231 breast carcinoma cells. Interestingly, reduced alpha6beta4 expression also promoted decreased migration on non-laminin substrata indicating that this integrin can function in a ligand-independent manner. In addition, the absence of beta4 expression in these cells augmented the formation of alpha6beta1 heterodimers and increased adhesion to laminin-1. Taken together, these results substantiate the importance of the alpha6beta4 integrin in invasion and migration that has been demonstrated previously by expression of the beta4 subunit in beta4-deficient cell lines and by function blocking antibodies. Furthermore, these data suggest that the utilization of siRNA oligonucleotides to reduce the expression of the alpha6beta4 integrin may be a useful approach to prevent carcinoma cell progression.

  9. Transport of alpha- and beta-D-glucose by the intact human red cell

    Energy Technology Data Exchange (ETDEWEB)

    Carruthers, A.; Melchior, D.L.

    1985-07-16

    The kinetics of alpha- and beta-D-glucose mutarotation and the transport of these anomers by intact human red cells were determined at 0.6 and 36.6 degrees C. The mutarotation coefficients for alpha- and beta-D-glucose in cell-free tris(hydroxymethyl)aminomethane medium (pH 7.4) at 0.6 degrees C are (2.25 +/- 0.2) and (1.73 +/- 0.42) X 10(-3) min-1, respectively, and at 36.6 degrees C are (69 +/- 12) and (75 +/- 5) X 10(-3) min-1, respectively. These values are in good agreement with previous estimates. At 0.6 degrees C, the red cell contains no detectable mutarotase activity. Initial rates of sugar uptake were measured by using radiolabeled D-glucose and time courses of uptake by turbidimetry. The time courses of alpha- and beta-D-glucose and an equilibrium mixture of alpha- and beta-D-glucose infinite-cis entry are identical at 0.66 degrees C (n = 41) where negligible mutarotation is observed. The apparent Ki values for inhibition of radiolabeled D-glucose initial uptake by unlabeled alpha- or beta-D-glucose at 0.6 degrees C are identical (1.6 mM). The calculated Vmax parameters for uptake of the radiolabeled anomers at this temperature are also indistinguishable. The time courses of infinite-cis alpha- and beta-D-glucose uptake at 36.66 degrees C are identical (n = 40). While D-glucose mutarotation is more rapid at this temperature, the anomers of D-glucose are not transported differently by the red cell hexose transfer system.

  10. Cell cycle phase dependent role of DNA polymerase beta in DNA repair and survival after ionizing radiation.

    NARCIS (Netherlands)

    Vermeulen, C.; Verwijs-Janssen, M.; Begg, A.C.; Vens, C.

    2008-01-01

    PURPOSE: The purpose of the present study was to determine the role of DNA polymerase beta in repair and response after ionizing radiation in different phases of the cell cycle. METHODS AND MATERIALS: Synchronized cells deficient and proficient in DNA polymerase beta were irradiated in different

  11. Lack of beta1 integrins in enteric neural crest cells leads to a Hirschsprung-like phenotype

    DEFF Research Database (Denmark)

    Breau, Marie A; Pietri, Thomas; Eder, Olivier

    2006-01-01

    The enteric nervous system arises mainly from vagal and sacral neural crest cells that colonise the gut between 9.5 and 14 days of development in mice. Using the Cre-LoxP system, we removed beta1 integrins in the neural crest cells when they emerge from the neural tube. beta1-null enteric neural...

  12. Beta spectroscopy on neutron-rich nuclei of mass 93<=A<=100

    International Nuclear Information System (INIS)

    Pahlmann, B.

    1982-01-01

    In the present thesis for the first time measurements of the Qsub(β) value of the neutron-rich fission products sup(99,100)Sr and 99 Rb were performed. Preliminary results could be obtained on the beta decays of the nuclides 100 Rb and 100 Y. (orig./HSI) [de

  13. The role of the beta1 subunit of the Na,K-ATPase and its glycosylation in cell-cell adhesion.

    Science.gov (United States)

    Vagin, Olga; Tokhtaeva, Elmira; Sachs, George

    2006-12-22

    Based on recent data showing that overexpression of the Na,K-ATPase beta(1) subunit increased cell-cell adhesion of nonpolarized cells, we hypothesized that the beta(1) subunit can also be involved in the formation of cell-cell contacts in highly polarized epithelial cells. In support of this hypothesis, in Madin-Darby canine kidney (MDCK) cells, the Na,K-ATPase alpha(1) and beta(1) subunits were detected as precisely co-localized with adherens junctions in all stages of the monolayer formation starting from the initiation of cell-cell contact. The Na,K-ATPase and adherens junction protein, beta-catenin, stayed partially co-localized even after their internalization upon disruption of intercellular contacts by Ca(2+) depletion of the medium. The Na,K-ATPase subunits remained co-localized with the adherens junctions after detergent treatment of the cells. In contrast, the heterodimer formed by expressed unglycosylated Na,K-ATPase beta(1) subunit and the endogenous alpha(1) subunit was easily dissociated from the adherens junctions and cytoskeleton by the detergent extraction. The MDCK cell line in which half of the endogenous beta(1) subunits in the lateral membrane were substituted by unglycosylated beta(1) subunits displayed a decreased ability to form cell-to-cell contacts. Incubation of surface-attached MDCK cells with an antibody against the extracellular domain of the Na,K-ATPase beta(1) subunit specifically inhibited cell-cell contact formation. We conclude that the Na,K-ATPase beta(1) subunit is involved in the process of intercellular adhesion and is necessary for association of the heterodimeric Na,K-ATPase with the adherens junctions. Further, normal glycosylation of the Na,K-ATPase beta(1) subunit is essential for the stable association of the pump with the adherens junctions and plays an important role in cell-cell contact formation.

  14. Beta cell imaging - a key tool in optimized diabetes prevention and treatment

    NARCIS (Netherlands)

    Gotthardt, M.; Eizirik, D.L.; Cnop, M.; Brom, M.

    2014-01-01

    The prevalence of diabetes is 382 million worldwide, and is expected to rise to 592 million in 2035 (http://www.idf.org/diabetesatlas); 2.5-15\\% of national annual healthcare budgets are related to diabetes care, potentially increasing to 40\\% in high-prevalence countries. Beta cell dysfunction and

  15. Autophagy in adipose tissue and the beta cell: implications for obesity and diabetes

    NARCIS (Netherlands)

    Stienstra, R.; Haim, Y.; Riahi, Y.; Netea, M.; Rudich, A.; Leibowitz, G.

    2014-01-01

    Autophagy is a lysosomal degradation pathway recycling intracellular long-lived proteins and damaged organelles, thereby maintaining cellular homeostasis. In addition to inflammatory processes, autophagy has been implicated in the regulation of adipose tissue and beta cell functions. In obesity and

  16. Inhibition of beta cell growth and function by bone morphogenetic proteins

    DEFF Research Database (Denmark)

    Bruun, Christine; Christensen, Gitte Lund; Jacobsen, Marie L B

    2014-01-01

    proliferation of rodent beta cells. The expression of Id mRNAs was induced by BMP4 in rat and human islets. Finally, glucose-induced insulin secretion was significantly impaired in rodent and human islets pre-treated with BMP4, and inhibition of BMP activity resulted in enhanced insulin release. CONCLUSIONS...

  17. MicroRNAs as regulators of beta-cell function and dysfunction

    DEFF Research Database (Denmark)

    Osmai, Mirwais; Osmai, Yama; Bang-Berthelsen, Claus Heiner

    2016-01-01

    , recent studies have demonstrated that miRNAs are important regulators of the islet transcriptome, controlling apoptosis, differentiation and proliferation, as well as regulating unique islet and beta-cell functions and pathways such as insulin expression, processing and secretion. Furthermore, a large...

  18. Pancreatic beta-Cell Dysfunction and Risk of New-Onset Diabetes After Kidney Transplantation

    NARCIS (Netherlands)

    Zelle, D.M.; Corpeleijn, E.; Deinum, J.; Stolk, R.P.; Gans, R.O.B.; Navis, G.; Bakker, S.J.L.

    OBJECTIVE-Chronic exposure to calcineurin inhibitors and corticosteroids poses renal transplant recipients (RTR) at high risk for development of new-onset diabetes after transplantation (NODAT). Pancreatic beta-cell dysfunction may be crucial to the pathophysiology of NODAT and specific markers for

  19. Beta-cell autoimmunity in pediatric celiac disease: the case for routine screening?

    Science.gov (United States)

    d'Annunzio, Giuseppe; Giannattasio, Alessandro; Poggi, Elena; Castellano, Emanuela; Calvi, Angela; Pistorio, Angela; Barabino, Arrigo; Lorini, Renata

    2009-02-01

    To evaluate the prevalence of beta-cell autoimmunity and the usefulness of a type 1 diabetes screening in patients with celiac disease. We measured GAD antibodies (GADAs), insulinoma-associated protein 2 antigens (IA-2As), and insulin autoantibodies (IAAs) in 188 young Italian patients with celiac disease (66 male [35.1%]). Mean age at celiac disease diagnosis was 5.4 years (0.5-17.1), and mean celiac disease duration was 4.2 years (0-28.8). Celiac disease was diagnosed by jejunal biopsy after positivity for endomysial and tissue transglutaminase antibody was confirmed. GADAs were positive in seven patients (3.7%), and IA-2As were positive in two patients. IAAs were negative in all cases. Metabolic evaluation was normal, and no patients developed diabetes during follow-up. There was no significant association among beta-cell autoimmunity and sex, age, pubertal stage, family history, or coexistence of other autoimmune disorders; compliance to a gluten-free diet was confirmed. Our results showed a low prevalence of beta-cell autoimmunity and do not support a precocious screening for beta-cell autoimmunity in young celiac disease patients.

  20. Effect of iron on pancreatic beta cell function and insulin resistance ...

    African Journals Online (AJOL)

    Background: Increase in total body iron store has been reported in the aetiology and development of diabetes mellitus. The effect of iron supplementation in female with respect to the incidence of diabetes mellitus was investigated on the pancreatic beta cell function and insulin resistance in normal female rats. Methods: ...

  1. Measuring beta-cell function relative to insulin sensitivity in youth: Does the hyperglycemic clamp suffice?

    Science.gov (United States)

    To compare beta-cell function relative to insulin sensitivity, disposition index (DI), calculated from two clamps (2cDI, insulin sensitivity from the hyperinsulinemic-euglycemic clamp and first-phase insulin from the hyperglycemic clamp) with the DI calculated from the hyperglycemic clamp alone (hcD...

  2. Impact of fetal and neonatal environment on beta cell function and development of diabetes

    DEFF Research Database (Denmark)

    Nielsen, Jens H; Haase, Tobias N; Jaksch, Caroline

    2014-01-01

    nutrients and gut microbiota on appetite regulation, mitochondrial activity and the immune system that may affect beta cell growth and function directly and indirectly is discussed. The possible role of epigenetic changes in the transgenerational transmission of the adverse programming may be the most...

  3. Regulation of NOX-1 expression in beta cells: a positive feedback loop involving the Src-kinase signaling pathway.

    Science.gov (United States)

    Weaver, J R; Taylor-Fishwick, D A

    2013-04-30

    NADPH oxidase-1 (NOX-1) is upregulated in beta cells in response to pro-inflammatory cytokines. Inhibition of NADPH oxidase activity blocked stimulated NOX-1 expression (pNOX-1 expression in beta cells followed modulation of cellular reactive oxygen species (ROS); pro-oxidants increased NOX-1 (pNOX-1 (pNOX-1 expression (pNOX-1 preserved beta cell function and survival. Collectively, these data indicate that expression of NOX-1 in beta cells is regulated in a feed-forward loop mediated by ROS and Src-kinase. Uncoupling of this feed-forward activation could provide new approaches to preserve and protect beta cells in diabetes. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  4. Inertial picobalance reveals fast mass fluctuations in mammalian cells

    Science.gov (United States)

    Martínez-Martín, David; Fläschner, Gotthold; Gaub, Benjamin; Martin, Sascha; Newton, Richard; Beerli, Corina; Mercer, Jason; Gerber, Christoph; Müller, Daniel J.

    2017-10-01

    The regulation of size, volume and mass in living cells is physiologically important, and dysregulation of these parameters gives rise to many diseases. Cell mass is largely determined by the amount of water, proteins, lipids, carbohydrates and nucleic acids present in a cell, and is tightly linked to metabolism, proliferation and gene expression. Technologies have emerged in recent years that make it possible to track the masses of single suspended cells and adherent cells. However, it has not been possible to track individual adherent cells in physiological conditions at the mass and time resolutions required to observe fast cellular dynamics. Here we introduce a cell balance (a ‘picobalance’), based on an optically excited microresonator, that measures the total mass of single or multiple adherent cells in culture conditions over days with millisecond time resolution and picogram mass sensitivity. Using our technique, we observe that the mass of living mammalian cells fluctuates intrinsically by around one to four per cent over timescales of seconds throughout the cell cycle. Perturbation experiments link these mass fluctuations to the basic cellular processes of ATP synthesis and water transport. Furthermore, we show that growth and cell cycle progression are arrested in cells infected with vaccinia virus, but mass fluctuations continue until cell death. Our measurements suggest that all living cells show fast and subtle mass fluctuations throughout the cell cycle. As our cell balance is easy to handle and compatible with fluorescence microscopy, we anticipate that our approach will contribute to the understanding of cell mass regulation in various cell states and across timescales, which is important in areas including physiology, cancer research, stem-cell differentiation and drug discovery.

  5. Structure of nuclei with masses 76 and 82 and nuclear matrix elements of neutrinoless double beta decay

    Science.gov (United States)

    Yoshinaga, N.; Yanase, K.; Higashiyama, K.; Teruya, E.; Taguchi, D.

    2018-02-01

    Nuclear shell-model calculations are carried out for isobaric nuclei with masses 76 and 82. Energy spectra and electromagnetic transition rates are compared with the experimental data. Using the wavefunctions thus obtained, nuclear matrix elements for the neutrinoless double beta decay are estimated. In order to investigate the model dependence on the nuclear matrix elements, pair-truncated shell-model calculations are also performed. By comparing the results with those in other models, the nuclear matrix elements are found to be sensitive to the ground-state correlations. In particular, nuclear matrix elements have strong correlations with pairing gaps.

  6. Sight threatening retinopathy in a child with sickle cell &beta ...

    African Journals Online (AJOL)

    Sight threatening retinopathy in a child with sickle cell β° Thalassaemia: case report. ... Sight threatening changes in the retina are a well-recognized complication of sickle cell disease (SCD). ... Two years later despite minimal visual symptoms, he had developed abnormal conjunctival vessels and bilateral retinopathy.

  7. Beta thalassaemia traits in Nigerian patients with sickle cell anaemia ...

    African Journals Online (AJOL)

    These three patients (1.2%) were found to have positive co-inheritance of thalassaemia trait and sickle cell anaemia. The erythrocyte indices were all reduced in these selected families except for one family whose mean cell haemoglobin concentration was within normal range. Peripheral blood film revealed the presence of ...

  8. Research of TGF-beta1 Inducing Lung Adencarcinoma PC9 Cells to Mesenchymal Cells Transition

    Directory of Open Access Journals (Sweden)

    Xiaofeng CHEN

    2010-01-01

    Full Text Available Background and objective It has been proven that epithelial-mesenchymal transition (EMT not only correlated with embryonic development but also could promote tumor invasion and metastasis. Transforming growth factor beta-1 (TGF-β1 has been identified as the main inducer of tumor EMT. The aim of this study was to investigate the effects of TGF-β1 on EMT and PI3K/AKT signaling pathway in lung adencarcinoma PC9 cells. Methods Cultured PC9 cells were treated with different concentrations of TGF-β1 for 48 h. The morphological changes were observed under phase-contrast microscopy; EMT relative marker protein changes were assessed by Western blot and immunoflurescence staining. In addition, the expression of AKT and P-AKT were also measured by Western blot. Results The data showed that TGF-β1 could induce PC9 morphological alteration from epithelial to mesenchymal and upregulate the expression of mesenchymal maker protein Fibronectin. Obviously, the expression of P-AKT was downregulated by TGF-β1 treatment for 48 h. Conclusion TGF-β1 might induce EMT of PC9 cells , accompanied by the changes of PI3K/AKT signaling pathway.

  9. Breakfast, plasma glucose and beta-hydroxybutyrate, body mass index and academic performance in children from Extremadura, Spain.

    Science.gov (United States)

    Torres, M D; Carmona, I; Campillo, C; Pérez, G; Campillo, J E

    2007-01-01

    Nutritional aspects of breakfast, plasma levels of glucose and beta-hydroxybutyrate, body mass index and academic performance have been studied in urban and rural children (Extremadura, Spain). Representative samples of schoolchildren (3 to 12 years old, random cluster-sampling in schools). Children's mean caloric intake with breakfast was 331 kcal. Rural population ingested more carbohydrates (46,9 +/- 12,3% versus 43,3 +/- 13,2% of the total caloric intake) and fewer lipids (40,5 +/- 11,8% versus 43,9 +/- 12,8% of the total caloric intake) than the urban population. Academic performance was significantly better in the children inhabiting the rural zone than in those of the urban zone. The glycaemia was higher in the urban than in the rural children, and that the contrary was the case for the beta-hydroxybutyrate values. Neither glucose nor beta-hydroxybutyrate levels were correlated with academic performance values. BMI was significantly increased in the urban versus rural children. The present results emphasize the importance of breakfast and life style in the weight and the academic performance of children.

  10. Reprogramming of pancreatic exocrine cells towards a beta (β) cell character using Pdx1, Ngn3 and MafA.

    Science.gov (United States)

    Akinci, Ersin; Banga, Anannya; Greder, Lucas V; Dutton, James R; Slack, Jonathan M W

    2012-03-15

    Pdx1 (pancreatic and duodenal homeobox 1), Ngn3 (neurogenin 3) and MafA (v-maf musculoaponeurotic fibrosarcoma oncogene family, protein A) have been reported to bring about the transdifferentiation of pancreatic exocrine cells to beta (β) cells in vivo. We have investigated the mechanism of this process using a standard in vitro model of pancreatic exocrine cells, the rat AR42j-B13 cell line. We constructed a new adenoviral vector encoding all three genes, called Ad-PNM (adenoviral Pdx1, Ngn3, MafA construct). When introduced into AR42j-B13 cells, Ad-PNM caused a rapid change to a flattened morphology and a cessation of cell division. The expression of exocrine markers is suppressed. Both insulin genes are up-regulated as well as a number of transcription factors normally characteristic of beta cells. At the chromatin level, histone tail modifications of the Pdx1, Ins1 (insulin 1) and Ins2 (insulin 2) gene promoters are shifted in a direction associated with gene activity, and the level of DNA CpG methylation is reduced at the Ins1 promoter. The transformed cells secrete insulin and are capable of relieving diabetes in streptozotocin-treated NOD-SCID (non-obese diabetic severe combined immunodeficiency) mice. However the transformation is not complete. The cells lack expression of several genes important for beta cell function and they do not show glucose-sensitive insulin secretion. We conclude that, for this exocrine cell model, although the transformation is dramatic, the reprogramming is not complete and lacks critical aspects of the beta cell phenotype.

  11. Evidence for the molecular heterogeneity of sickle cell anemia chromosomes bearing the betaS/Benin haplotype.

    Science.gov (United States)

    Patrinos, George P; Samperi, Piera; Lo Nigro, Luca; Kollia, Panagoula; Schiliro, Gino; Papadakis, Manoussos N

    2005-09-01

    There are at least four distinct African and one Asian chromosomal backgrounds (haplotypes) on which the sickle cell mutation has arisen. Additionally, previous data suggest that the beta(S)/Bantu haplotype is heterogeneous at the molecular level. Here, we report the presence of the (A)gamma -499 T-->A variation in sickle cell anemia chromosomes of Sicilian and North African origin bearing the beta(S)/Benin haplotype. Being absent from North American beta(S)/Benin chromosomes, which were studied previously, this variation is indicative for the molecular heterogeneity of the beta(S)/Benin haplotype. Copyright 2005 Wiley-Liss, Inc.

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

    DEFF Research Database (Denmark)

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

    1989-01-01

    The regulation of the growth of the pancreatic beta-cell is poorly understood. There are previous indications of a role of GH in the growth and insulin production of the pancreatic islets. In the present study we present evidence for a direct long-term effect of GH on proliferation and insulin...... biosynthesis of pancreatic beta-cells in monolayer culture. In culture medium RPMI 1640 supplemented with 2% normal human serum islets or dissociated islet cells from newborn rats maintained their insulin-producing capacity. When supplemented with 1-1000 ng/ml pituitary or recombinant human GH the islet cells...... was accompanied with a continuous increase in insulin release to the culture medium reaching a 10- 20-fold increase after 2-3 months with a half-maximal effect at about 10 ng/ml human GH. The biosynthesis of (pro)insulin was markedly increased with a normal rate of conversion of proinsulin to insulin...

  13. Mobility of creatine phosphokinase and beta-enolase in cultured muscle cells

    OpenAIRE

    Arrio-Dupont, M.; Foucault, G.; Vacher, M.; Douhou, A.; Cribier, S.

    1997-01-01

    The diffusion of beta-enolase and creatine phosphokinase in muscle cells has been studied by modulated fringe pattern photobleaching. Beta-enolase is mobile in the sarcoplasm. At 20 degrees C, the diffusion coefficient is 13.5 +/- 2.5 microm2 s(-1) in the cytosol and 56 microm2 s(-1) in aqueous media. As in the case of dextrans of the same hydrodynamic radius, its mobility is hindered by both the crowding of the fluid phase of the cytoplasm and the screening effect due to myofilaments. A frac...

  14. Trans fatty acids increase nitric oxide levels and pancreatic beta-cell necrosis in rats

    Directory of Open Access Journals (Sweden)

    Kusmiyati Tjahjono DK

    2013-04-01

    Full Text Available Background The prevalence of diabetes in Indonesia is increasing due to various factors, including life style changes such as trans fatty acid (TFA intake. High TFA intake is known to be related to blood lipid profile changes resulting in cardiovascular disorders. This study was to identify the effect of TFA on nitric oxide (NO production and on necrosis of pancreatic beta cells. Methods A study of randomized pre-test post–test design with control group. Thirty Sprague Dawley rats were divided into 3 groups, i.e. group K (control, group P1 receiving a diet with 5% TFA, and P2 receiving 10% TFA. The intervention was performed for 8 weeks. NO level and pancreatic beta-cell necrosis were analyzed using Pearson’s chi square test. Results After 4 weeks of treatment there was no change in NO levels in group K, but increased NO in P2 (2.6-3.8 ìM. At 8 weeks after treatment, NO levels in groups P1 and P2 increased to 2.6-3.4 ìM and 4.2-14.3 ìM, respectively, while in group K only 2 rats had increased NO levels of 2.8-2.9 ìM. With Pearson’s chi-square test, there was a signifant difference in the proportions of necrotic pancreatic beta cells after 4 weeks and 8 weeks (p=0.000. No necrosis of beta cells was found in group K, mild necrosis in group P1 (1-25% and moderate necrosis in group P2 (26-50%. Conclusion TFA consumption significantly increases NO levels in Sprague Dawley rats and also results in moderate grades of necrosis of pancreatic beta cells.

  15. Trans fatty acids increase nitric oxide levels and pancreatic beta-cell necrosis in rats

    Directory of Open Access Journals (Sweden)

    Kusmiyati Tjahjono DK

    2015-12-01

    Full Text Available BACKGROUND The prevalence of diabetes in Indonesia is increasing due to various factors, including life style changes such as trans fatty acid (TFA intake. High TFA intake is known to be related to blood lipid profile changes resulting in cardiovascular disorders. This study was to identify the effect of TFA on nitric oxide (NO production and on necrosis of pancreatic beta cells. METHODS A study of randomized pre-test post–test design with control group. Thirty Sprague Dawley rats were divided into 3 groups, i.e. group K (control, group P1 receiving a diet with 5% TFA, and P2 receiving 10% TFA. The intervention was performed for 8 weeks. NO level and pancreatic beta-cell necrosis were analyzed using Pearson’s chi square test. RESULTS After 4 weeks of treatment there was no change in NO levels in group K, but increased NO in P2 (2.6-3.8 ìM. At 8 weeks after treatment, NO levels in groups P1 and P2 increased to 2.6-3.4 ìM and 4.2-14.3 ìM, respectively, while in group K only 2 rats had increased NO levels of 2.8-2.9 ìM. With Pearson’s chi-square test, there was a signifant difference in the proportions of necrotic pancreatic beta cells after 4 weeks and 8 weeks (p= 0.000. No necrosis of beta cells was found in group K, mild necrosis in group P1 (1-25% and moderate necrosis in group P2 (26-50%. CONCLUSION TFA consumption significantly increases NO levels in Sprague Dawley rats and also results in moderate grades of necrosis of pancreatic beta cells

  16. Movement of beta-irradiated epidermal basal cells to the spinous-granular layers in the absence of cell division

    International Nuclear Information System (INIS)

    Etoh, H.; Taguchi, Y.H.; Tabachnick, J.

    1975-01-01

    Guinea-pig epidermis was irradiated with 3000 rad of beta rays 1 hr after two injections of [ 3 H]thymidine 5 hr apart (labeled cells in S phase and G 2 phase) or 18 hr after injection (labeled early G 1 cells). In nonirradiated epidermis labeled basal cells divided within 24 hr with daughter cells remaining in the basal layer, and approximately 50 percent of the labeled cells moved into the spinal layer by the 3rd day. Cell division in nonirradiated epidermis diluted the number of silver grains/nucleus, and lightly labeled cells were found in the granular layer by day 7. Beta irradiation inhibited cell division but it did not slow the rate of transit (ca 8 days) of irradiated labeled cells from basal to granular layer, some of these remaining heavily labeled. Although cell division may play some role in upward movement of basal cells in normal epidermis detachment of a basal cell from the basement membrane and its transit to the granular layer is unimpaired in the absence of cell division. These findings suggest that some radioresistant metabolic function(s), not cell division, is responsible for upward movement of basal cells. (auth)

  17. Dual role of proapoptotic BAD in insulin secretion and beta cell survival

    OpenAIRE

    Danial, Nika N.; Walensky, Loren D.; Zhang, Chen-Yu; Choi, Cheol Soo; Fisher, Jill K.; Molina, Anthony J. A.; Datta, Sandeep Robert; Pitter, Kenneth L.; Bird, Gregory H.; Wikstrom, Jakob D.; Deeney, Jude T.; Robertson, Kirsten; Morash, Joel; Kulkarni, Ameya; Neschen, Susanne

    2008-01-01

    The proapoptotic BCL-2 family member BAD resides in a glucokinase-containing complex that regulates glucose-driven mitochondrial respiration. Here, we present genetic evidence of a physiologic role for BAD in glucose-stimulated insulin secretion by beta cells. This novel function of BAD is specifically dependent upon the phosphorylation of its BH3 sequence, previously defined as an essential death domain. We highlight the pharmacologic relevance of phosphorylated BAD BH3 by using cell-permeab...

  18. Progenitor potential of nkx6.1-expressing cells throughout zebrafish life and during beta cell regeneration.

    Science.gov (United States)

    Ghaye, Aurélie P; Bergemann, David; Tarifeño-Saldivia, Estefania; Flasse, Lydie C; Von Berg, Virginie; Peers, Bernard; Voz, Marianne L; Manfroid, Isabelle

    2015-09-02

    In contrast to mammals, the zebrafish has the remarkable capacity to regenerate its pancreatic beta cells very efficiently. Understanding the mechanisms of regeneration in the zebrafish and the differences with mammals will be fundamental to discovering molecules able to stimulate the regeneration process in mammals. To identify the pancreatic cells able to give rise to new beta cells in the zebrafish, we generated new transgenic lines allowing the tracing of multipotent pancreatic progenitors and endocrine precursors. Using novel bacterial artificial chromosome transgenic nkx6.1 and ascl1b reporter lines, we established that nkx6.1-positive cells give rise to all the pancreatic cell types and ascl1b-positive cells give rise to all the endocrine cell types in the zebrafish embryo. These two genes are initially co-expressed in the pancreatic primordium and their domains segregate, not as a result of mutual repression, but through the opposite effects of Notch signaling, maintaining nkx6.1 expression while repressing ascl1b in progenitors. In the adult zebrafish, nkx6.1 expression persists exclusively in the ductal tree at the tip of which its expression coincides with Notch active signaling in centroacinar/terminal end duct cells. Tracing these cells reveals that they are able to differentiate into other ductal cells and into insulin-expressing cells in normal (non-diabetic) animals. This capacity of ductal cells to generate endocrine cells is supported by the detection of ascl1b in the nkx6.1:GFP ductal cell transcriptome. This transcriptome also reveals, besides actors of the Notch and Wnt pathways, several novel markers such as id2a. Finally, we show that beta cell ablation in the adult zebrafish triggers proliferation of ductal cells and their differentiation into insulin-expressing cells. We have shown that, in the zebrafish embryo, nkx6.1+ cells are bona fide multipotent pancreatic progenitors, while ascl1b+ cells represent committed endocrine precursors. In

  19. Targeted radiosensitization of cells expressing truncated DNA polymerase {beta}.

    NARCIS (Netherlands)

    Neijenhuis, S.; Verwijs-Janssen, M.; Broek, Bart van den; Begg, A.C.; Vens, C.

    2010-01-01

    Ionizing radiation (IR) is an effective anticancer treatment, although failures still occur. To improve radiotherapy, tumor-targeted strategies are needed to increase radiosensitivity of tumor cells, without influencing normal tissue radiosensitivity. Base excision repair (BER) and single-strand

  20. Nonblack patients with sickle cell disease have African. beta. sup s gene cluster haplotypes

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, Z.R.; Powars, D.R.; Williams, W.D. (Univ. of Southern California School of Medicine, Los Angeles (USA)); Kinney, T.R. (Duke Univ., Durham, NC (USA)); Schroeder, W.A. (California Institute of Technology, Pasadena (USA))

    1989-05-26

    Of 18 nonblack patients with sickle cell disease, 14 had sickle cell anemia, 2 had hemoglobin SC disease, and 2 had hemoglobin S-{beta}{sup o}-thalassemia. The {beta}{sup s} gene cluster haplotypes that were determined in 7 patients were of African origin and were identified as Central African Republic, Central African Republic minor II, Benin, and Senegal. The haplotype Central African Republic minor II was present on the {beta}{sup o}-thalassemia chromosome in 2 patients. None of 10 patients whose {alpha}-gene status was determined had {alpha}-thalassemia-2. These data strongly support the concept that the {beta}{sup s} gene on chromosome 11 of these individuals is of African origin and that the {alpha}-gene locus on chromosome 16 is of white or native American origin. The clinical severity of the disease in these nonblack patients is appropriate to their haplotype without {alpha}-thalassemia-2 and is comparable with that of black patients. All persons with congenital hemolytic anemia should be examined for the presence of sickle cell disease regardless of physical appearance or ethnic background.

  1. Fetal and adult hematopoietic stem cells require beta1 integrin function for colonizing fetal liver, spleen, and bone marrow.

    Science.gov (United States)

    Potocnik, A J; Brakebusch, C; Fässler, R

    2000-06-01

    Homing of hematopoietic stem cells (HSCs) into hematopoietic organs is a prerequisite for the establishment of hematopoiesis during embryogenesis and after bone marrow transplantation. We show that beta1 integrin-deficient HSCs from the para-aortic splanchnopleura and the fetal blood had hematolymphoid differentiation potential in vitro and in fetal organ cultures but were unable to seed fetal and adult hematopoietic tissues. Adult beta1 integrin null HSCs isolated from mice carrying loxP-tagged beta1 integrin alleles and ablated for beta1 integrin expression by retroviral cre transduction failed to engraft irradiated recipient mice. Moreover, absence of beta1 integrin resulted in sequestration of HSCs in the circulation and their reduced adhesion to endothelioma cells. These findings define beta1 integrin as an essential adhesion receptor for the homing of HSCs.

  2. Fetal and adult hematopoietic stem cells require beta1 integrin function for colonizing fetal liver, spleen, and bone marrow

    DEFF Research Database (Denmark)

    Potocnik, A J; Brakebusch, C; Fässler, R

    2000-01-01

    Homing of hematopoietic stem cells (HSCs) into hematopoietic organs is a prerequisite for the establishment of hematopoiesis during embryogenesis and after bone marrow transplantation. We show that beta1 integrin-deficient HSCs from the para-aortic splanchnopleura and the fetal blood had...... failed to engraft irradiated recipient mice. Moreover, absence of beta1 integrin resulted in sequestration of HSCs in the circulation and their reduced adhesion to endothelioma cells. These findings define beta1 integrin as an essential adhesion receptor for the homing of HSCs....... hematolymphoid differentiation potential in vitro and in fetal organ cultures but were unable to seed fetal and adult hematopoietic tissues. Adult beta1 integrin null HSCs isolated from mice carrying loxP-tagged beta1 integrin alleles and ablated for beta1 integrin expression by retroviral cre transduction...

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

    Directory of Open Access Journals (Sweden)

    Deborah A Striegel

    2015-08-01

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

  4. The alpha3 laminin subunit, alpha6beta4 and alpha3beta1 integrin coordinately regulate wound healing in cultured epithelial cells and in the skin

    DEFF Research Database (Denmark)

    Goldfinger, L E; Hopkinson, S B; deHart, G W

    1999-01-01

    . In these cells, integrin alpha3beta1 occasionally colocalizes with the staining generated by the 12C4 antibody but alpha6beta4 integrin does not. In wounded MCF-10A cell cultures, the 12C4 antibody stains the extracellular matrix beneath those cells at the very edge of the cellular sheet that moves to cover......Previously, we demonstrated that proteolytic processing within the globular domain of the alpha3 subunit of laminin-5 (LN5) converts LN5 from a cell motility-inducing factor to a protein complex that can trigger the formation of hemidesmosomes, certain cell-matrix attachment sites found...... in epithelial cells. We have prepared a monoclonal antibody (12C4) whose epitope is located toward the carboxy terminus of the globular domain of the alpha3 laminin subunit. This epitope is lost from the alpha3 subunit as a consequence of proteolytic processing. Antibody 12C4 stains throughout the matrix...

  5. Another look at the impact of an eV-mass sterile neutrino on the effective neutrino mass of neutrinoless double-beta decays

    Science.gov (United States)

    Liu, Jun-Hao; Zhou, Shun

    2018-01-01

    The possible existence of an eV-mass sterile neutrino, slightly mixing with ordinary active neutrinos, is not yet excluded by neutrino oscillation experiments. Assuming neutrinos to be Majorana particles, we explore the impact of such a sterile neutrino on the effective neutrino mass of neutrinoless double-beta decays 〈m〉ee‧≡ m 1|V e1|2eiρ + m 2|V e2|2 + m 3|V e3|2eiσ + m 4|V e4|2eiω, where mi and Vei (for i = 1, 2, 3, 4) denote respectively the absolute masses and the first-row elements of the 4 × 4 neutrino flavor mixing matrix V, for which a full parametrization involves three Majorana-type CP-violating phases {ρ,σ,ω}. A zero effective neutrino mass |〈m〉ee‧| = 0 is possible, no matter whether three active neutrinos take the normal or inverted mass ordering, and its implications for the parameter space are examined in great detail. In particular, given the best-fit values of m4 ≈ 1.3eV and |Ve4|2 ≈ 0.019 from the latest global analysis of neutrino oscillation data, a three-dimensional view of |〈m〉ee‧| in the (mlightest,ρ)-plane is presented and further compared with that of the counterpart |〈m〉ee| in the absence of any sterile neutrino.

  6. Poly(vinyl alcohol)/sulfated {beta}-cyclodextrin for direct methanol fuel cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Tao [School of Chemical Engineering, Huaihai Institute of Technology, Lianyungang, Jiangsu 222005 (China)

    2009-08-15

    We report a composite membrane based on poly(vinyl alcohol) and sulfated {beta}-cyclodextrin in this paper. TGA and SEM tests provide direct evidence of the thermal stability and the uniform structure of the composite membranes. The performances of the composite membranes are investigated in terms of swelling behavior, methanol permeability and proton conductivity as function of sulfated {beta}-cyclodextrin content. We find that the introduction of sulfated {beta}-cyclodextrin can reduce water uptake. The temperature dependence of proton conductivity reveals that the proton conducting activation energy of the composite membranes is similar to that of Nafion 115, in other words, both the vehicle and Grotthus mechanisms are assumed to be responsible for the composite membranes' proton transfer. Methanol permeability decreases as the methanol feed concentration increases from 2 M to 20 M. Both proton conductivity and methanol permeability increases with increasing sulfated {beta}-cyclodextrin. The selectivity of the composite membranes defined as the ratio of proton conductivity to methanol permeability obtains the maximum of 1.710 x 10{sup 4} S s cm{sup -3} at the composition of 17 wt.% sulfated {beta}-cyclodextrin. The MEAs fabricate with these membranes are tested, no distinct change occurred to the composite membranes after the MEAs operating for 288 h. These data indicates the chemical and electrochemical stability of the membranes and their potential application in direct methanol fuel cells. (author)

  7. Induction of cell scattering by expression of beta1 integrins in beta1-deficient epithelial cells requires activation of members of the rho family of GTPases and downregulation of cadherin and catenin function

    DEFF Research Database (Denmark)

    Gimond, C; van Der Flier, A; van Delft, S

    1999-01-01

    beta1 prevented the disruption of intercellular adhesions and cell scattering. In addition, using biochemical activity assays for Rho-like GTPases, we show that the expression of beta1A, beta1D, or IL2R-beta1A in GE11 or GD25 cells triggers activation of both RhoA and Rac1, but not of Cdc42. Moreover......, dominant negative Rac1 (N17Rac1) inhibited the disruption of cell-cell adhesions when expressed before beta1. However, all three GTPases might be involved in the morphological transition, since expression of either N19RhoA, N17Rac1, or N17Cdc42 reversed cell scattering and partially restored cadherin......-based adhesions in GE11-beta1A cells. Our results indicate that beta1 integrins regulate the polarity and motility of epithelial cells by the induction of intracellular molecular events involving a downregulation of alpha-catenin function and the activation of the Rho-like G proteins Rac1 and RhoA....

  8. Location of the sulphonylurea receptor at the cytoplasmic face of the beta-cell membrane.

    Science.gov (United States)

    Schwanstecher, M; Schwanstecher, C; Dickel, C; Chudziak, F; Moshiri, A; Panten, U

    1994-11-01

    1. In insulin-secreting cells the location of the sulphonylurea receptor was examined by use of a sulphonylurea derivative representing the glibenclamide molecule devoid of its cyclohexy moiety (compound III) and a benzenesulphonic acid derivative representing the glibenclamide molecule devoid of its cyclohexylurea moiety (compound IV). At pH 7.4 compound IV is only present in charged form. 2. Lipid solubility declined in the order tolbutamide > compound III > compound IV. 3. The dissociation constant (KD) for binding of compound IV to the sulphonylurea receptor in HIT-cells (pancreatic beta-cell line) was similar to the KD value for tolbutamide and fourfold higher than the KD value for compound III. 4. In mouse pancreatic beta-cells, drug concentrations inhibiting adenosine 5'-triphosphate-sensitive K+ channels (KATP-channels) half-maximally (EC50) were determined by use of the patch-clamp technique. When the drugs were applied to the extracellular side of outside-out or the intracellular side of inside-out membrane patches, the ratio of extracellular to intracellular EC50 values was 281 for compound IV, 25.5 for compound III and 1.2 for tolbutamide. 5. In mouse pancreatic beta-cells, measurement of KATP-channel activity in cell-attached patches and recording of insulin release displayed much higher EC50 values for compound IV than inside-out patch experiments. A corresponding, but less pronounced difference in EC50 values was observed for compound III, whereas the EC50 values for tolbutamide did not differ significantly. 6. It is concluded that the sulphonylurea receptor is located at the cytoplasmic face of the beta-cell plasma membrane. Receptor activation is induced by the anionic forms of sulphonylureas and their analogues.

  9. Differential Recognition of CD1d-[alpha]-Galactosyl Ceramide by the V[beta]8.2 and V[beta]7 Semi-invariant NKT T Cell Receptors

    Energy Technology Data Exchange (ETDEWEB)

    Pellicci, Daniel G.; Patel, Onisha; Kjer-Nielsen, Lars; Pang, Siew Siew; Sullivan, Lucy C.; Kyparissoudis, Konstantinos; Brooks, Andrew G.; Reid, Hugh H.; Gras, Stephanie; Lucet, Isabelle S.; Koh, Ruide; Smyth, Mark J.; Mallevaey, Thierry; Matsuda, Jennifer L.; Gapin, Laurent; McCluskey, James; Godfrey, Dale I.; Rossjohn, Jamie; PMCI-A; Monash; UCHSC; Melbourne

    2009-09-02

    The semi-invariant natural killer T cell receptor (NKT TCR) recognizes CD1d-lipid antigens. Although the TCR{alpha} chain is typically invariant, the {beta} chain expression is more diverse, where three V{beta} chains are commonly expressed in mice. We report the structures of V{alpha}14-V{beta}8.2 and V{alpha}14-V{beta}7 NKT TCRs in complex with CD1d-{alpha}-galactosylceramide ({alpha}-GalCer) and the 2.5 {angstrom} structure of the human NKT TCR-CD1d-{alpha}-GalCer complex. Both V{beta}8.2 and V{beta}7 NKT TCRs and the human NKT TCR ligated CD1d-{alpha}-GalCer in a similar manner, highlighting the evolutionarily conserved interaction. However, differences within the V{beta} domains of the V{beta}8.2 and V{beta}7 NKT TCR-CD1d complexes resulted in altered TCR{beta}-CD1d-mediated contacts and modulated recognition mediated by the invariant {alpha} chain. Mutagenesis studies revealed the differing contributions of V{beta}8.2 and V{beta}7 residues within the CDR2{beta} loop in mediating contacts with CD1d. Collectively we provide a structural basis for the differential NKT TCR V{beta} usage in NKT cells.

  10. Stronger control of ATP/ADP by proton leak in pancreatic beta-cells than skeletal muscle mitochondria.

    Science.gov (United States)

    Affourtit, Charles; Brand, Martin D

    2006-01-01

    Pancreatic beta cells respond to rising blood glucose concentrations by increasing their oxidative metabolism, which leads to an increased ATP/ADP ratio, closure of K(ATP) channels, depolarization of the plasma membrane potential, influx of calcium and the eventual secretion of insulin. Such a signalling mechanism implies that the ATP/ADP ratio is flexible in beta cells (beta-cells), which is in contrast with other cell types (e.g. muscle and liver) that maintain a stable ATP/ADP poise while respiring at widely varying rates. To determine whether this difference in flexibility is accounted for by mitochondrial peculiarities, we performed a top-down metabolic control analysis to quantitatively assess how ATP/ADP is controlled in mitochondria isolated from rat skeletal muscle and cultured beta cells. We show that the ATP/ADP ratio is more strongly controlled (approx. 7.5-fold) by proton leak in beta cells than in muscle. The comparatively high importance of proton leak in beta cell mitochondria (relative to phosphorylation) is evidenced furthermore by its relatively high level of control over membrane potential and overall respiratory activity. Modular-kinetic analysis of oxidative phosphorylation reveals that these control differences can be fully explained by a higher relative leak activity in beta cell mitochondria, which results in a comparatively high contribution of proton leak to the overall respiratory activity in this system.

  11. The effect of noise on beta-cell burst period

    DEFF Research Database (Denmark)

    Pedersen, Morten Gram; Sørensen, Mads Peter

    2006-01-01

    isolated and coupled cells has been suggested to be due to stochastic fluctuations of the plasma membrane ions channels, which are supposed to have a stronger effect on single cells than on cells situated in clusters (the channel sharing hypothesis). This effect of noise has previously been studied based...... system, but with a quantitative description of the effect of noise. This approach supports previous investigations of the channel sharing hypothesis....... on numerical simulations. We show here how the application of two recent methods allows an analytic treatment of the stochastic effects on the location of the saddle-node and homoclinic bifurcations, which determine the burst period. Thus, the stochastic system can be analyzed similarly to the deterministic...

  12. Identification of beta-2 as a key cell adhesion molecule in PCa cell neurotropic behavior: a novel ex vivo and biophysical approach.

    Science.gov (United States)

    Jansson, Keith H; Castillo, Deborah G; Morris, Joseph W; Boggs, Mary E; Czymmek, Kirk J; Adams, Elizabeth L; Schramm, Lawrence P; Sikes, Robert A

    2014-01-01

    Prostate cancer (PCa) is believed to metastasize through the blood/lymphatics systems; however, PCa may utilize the extensive innervation of the prostate for glandular egress. The interaction of PCa and its nerve fibers is observed in 80% of PCa and is termed perineural invasion (PNI). PCa cells have been observed traveling through the endoneurium of nerves, although the underlying mechanisms have not been elucidated. Voltage sensitive sodium channels (VSSC) are multimeric transmembrane protein complexes comprised of a pore-forming α subunit and one or two auxiliary beta (β) subunits with inherent cell adhesion molecule (CAM) functions. The beta-2 isoform (gene SCN2B) interacts with several neural CAMs, while interacting putatively with other prominent neural CAMs. Furthermore, beta-2 exhibits elevated mRNA and protein levels in highly metastatic and castrate-resistant PCa. When overexpressed in weakly aggressive LNCaP cells (2BECFP), beta-2 alters LNCaP cell morphology and enhances LNCaP cell metastasis associated behavior in vitro. We hypothesize that PCa cells use beta-2 as a CAM during PNI and subsequent PCa metastasis. The objective of this study was to determine the effect of beta-2 expression on PCa cell neurotropic metastasis associated behavior. We overexpressed beta-2 as a fusion protein with enhanced cyan fluorescence protein (ECFP) in weakly aggressive LNCaP cells and observed neurotropic effects utilizing our novel ex vivo organotypic spinal cord co-culture model, and performed functional assays with neural matrices and atomic force microscopy. With increased beta-2 expression, PCa cells display a trend of enhanced association with nerve axons. On laminin, a neural CAM, overexpression of beta-2 enhances PCa cell migration, invasion, and growth. 2BECFP cells exhibit marked binding affinity to laminin relative to LNECFP controls, and recombinant beta-2 ectodomain elicits more binding events to laminin than BSA control. Functional overexpression of VSSC

  13. Hexachlorophene suppresses beta-catenin expression by up-regulation of Siah-1 in EBV-infected B lymphoma cells.

    Science.gov (United States)

    Min, Hye-Jin; Cho, Il-Rae; Srisuttee, Ratakorn; Park, Eun-Hee; Cho, Dae Ho; Ahn, Jin-Hyun; Lee, Im-Soon; Johnston, Randal N; Oh, Sangtaek; Chung, Young-Hwa

    2009-04-18

    Many studies have shown that the activation of beta-catenin signaling can promote oncogenesis, and it is therefore of interest to find agents that modulate this pathway. Recent work has shown using B lymphoma cells that infection by Epstein-Barr virus (EBV) and expression of its latent membrane protein (LMP)-1, cause increases in the expression of beta-catenin and cellular transformation. Conversely, results from cell-based small molecule screening studies have shown that the antibiotic hexachlorophene can down-regulate beta-catenin in colon cancer cells. Here we report that hexachlorophene also counteracts the elevated beta-catenin levels in EBV-infected B lymphomas. This is associated with restoration in levels of Siah-1 (an E3 ubiquitin ligase that is active in beta-catenin regulation) which had been diminished by LMP-1. Our results suggest that Siah-1 is targeted by both LMP-1 and hexachlorophene with opposite effects. The hexachlorophene modulation of Siah-1 and beta-catenin is independent of p53 and results in reduced expression of cyclin-D1 and c-Myc (target genes of beta-catenin), leading to the growth arrest of B lymphoma cells. From these results we propose that hexachlorophene may provide a novel therapeutic strategy for EBV-infected B lymphoma cells by reducing beta-catenin levels via the restoration of Siah-1.

  14. Neurofilament heavy polypeptide regulates the Akt-beta-catenin pathway in human esophageal squamous cell carcinoma.

    Directory of Open Access Journals (Sweden)

    Myoung Sook Kim

    2010-02-01

    Full Text Available Aerobic glycolysis and mitochondrial dysfunction are common features of aggressive cancer growth. We observed promoter methylation and loss of expression in neurofilament heavy polypeptide (NEFH in a significant proportion of primary esophageal squamous cell carcinoma (ESCC samples that were of a high tumor grade and advanced stage. RNA interference-mediated knockdown of NEFH accelerated ESCC cell growth in culture and increased tumorigenicity in vivo, whereas forced expression of NEFH significantly inhibited cell growth and colony formation. Loss of NEFH caused up-regulation of pyruvate kinase-M2 type and down-regulation of pyruvate dehydrogenase, via activation of the Akt/beta-catenin pathway, resulting in enhanced aerobic glycolysis and mitochondrial dysfunction. The acceleration of glycolysis and mitochondrial dysfunction in NEFH-knockdown cells was suppressed in the absence of beta-catenin expression, and was decreased by the treatment of 2-Deoxyglucose, a glycolytic inhibitor, or API-2, an Akt inhibitor. Loss of NEFH activates the Akt/beta-catenin pathway and increases glycolysis and mitochondrial dysfunction. Cancer cells with methylated NEFH can be targeted for destruction with specific inhibitors of deregulated downstream pathways.

  15. Crystal Structure of Staphylococcal Enterotoxin G (SEG) in Complex with a Mouse T-cell Receptor Beta Chain

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, M.M.; Robinson, H.; Cho, S.; De Marzi, M. C.; Kerzic, M. C.; Mariuzza, R. A.; Malchiodi, E. L.

    2011-01-14

    Superantigens (SAgs) are bacterial or viral toxins that bind MHC class II (MHC-II) molecules and T-cell receptor (TCR) in a nonconventional manner, inducing T-cell activation that leads to inflammatory cytokine production, which may result in acute toxic shock. In addition, the emerging threat of purpura fulminans and community-associated meticillin-resistant Staphylococcus aureus emphasizes the importance of a better characterization of SAg binding to their natural ligands that may allow the development of reagents to neutralize their action. The three-dimensional structure of the complex between a mouse TCR {beta} chain (mV{beta}8.2) and staphylococcal enterotoxin G (SEG) at 2.0 {angstrom} resolution revealed a binding site that does not conserve the 'hot spots' present in mV{beta}8.2-SEC2, mV{beta}8.2-SEC3, mV{beta}8.2-SEB, and mV{beta}8.2-SPEA complexes. Analysis of the mV{beta}8.2-SEG interface allowed us to explain the higher affinity of this complex compared with the others, which may account for the early activation of T-cells bearing mV{beta}8.2 by SEG. This mode of interaction between SEG and mV{beta}8.2 could be an adaptive advantage to bestow on the pathogen a faster rate of colonization of the host.

  16. An Abbreviated Protocol for In Vitro Generation of Functional Human Embryonic Stem Cell-Derived Beta-Like Cells.

    Directory of Open Access Journals (Sweden)

    Mohammad Massumi

    Full Text Available The ability to yield glucose-responsive pancreatic beta-cells from human pluripotent stem cells in vitro will facilitate the development of the cell replacement therapies for the treatment of Type 1 Diabetes. Here, through the sequential in vitro targeting of selected signaling pathways, we have developed an abbreviated five-stage protocol (25-30 days to generate human Embryonic Stem Cell-Derived Beta-like Cells (ES-DBCs. We showed that Geltrex, as an extracellular matrix, could support the generation of ES-DBCs more efficiently than that of the previously described culture systems. The activation of FGF and Retinoic Acid along with the inhibition of BMP, SHH and TGF-beta led to the generation of 75% NKX6.1+/NGN3+ Endocrine Progenitors. The inhibition of Notch and tyrosine kinase receptor AXL, and the treatment with Exendin-4 and T3 in the final stage resulted in 35% mono-hormonal insulin positive cells, 1% insulin and glucagon positive cells and 30% insulin and NKX6.1 co-expressing cells. Functionally, ES-DBCs were responsive to high glucose in static incubation and perifusion studies, and could secrete insulin in response to successive glucose stimulations. Mitochondrial metabolic flux analyses using Seahorse demonstrated that the ES-DBCs could efficiently metabolize glucose and generate intracellular signals to trigger insulin secretion. In conclusion, targeting selected signaling pathways for 25-30 days was sufficient to generate ES-DBCs in vitro. The ability of ES-DBCs to secrete insulin in response to glucose renders them a promising model for the in vitro screening of drugs, small molecules or genes that may have potential to influence beta-cell function.

  17. Functional labeling of insulin receptor subunits in live cells. Alpha 2 beta 2 species is the major autophosphorylated form

    International Nuclear Information System (INIS)

    Le Marchand-Brustel, Y.; Ballotti, R.; Gremeaux, T.; Tanti, J.F.; Brandenburg, D.; Van Obberghen, E.

    1989-01-01

    Both receptor subunits were functionally labeled in order to provide methods allowing, in live cells and in broken cell systems, concomitant evaluation of the insulin receptor dual function, hormone binding, and kinase activity. In cell-free systems, insulin receptors were labeled on their alpha-subunit with 125I-photoreactive insulin, and on their beta-subunit by autophosphorylation. Thereafter, phosphorylated receptors were separated from the complete set of receptors by means of anti-phosphotyrosine antibodies. Using this approach, a subpopulation of receptors was found which had bound insulin, but which were not phosphorylated. Under nonreducing conditions, receptors appeared in three oligomeric species identified as alpha 2 beta 2, alpha 2 beta, and alpha 2. Mainly the alpha 2 beta 2 receptor species was found to be phosphorylated while insulin was bound to alpha 2 beta 2, alpha 2 beta, and alpha 2 forms. In live cells, biosynthetic labeling of insulin receptors was used. Receptors were first labeled with [35S]methionine. Subsequently, the addition of insulin led to receptor autophosphorylation by virtue of the endogenous ATP pool. The total amount of [35S]methionine-labeled receptors was precipitated with antireceptor antibodies, whereas with anti-phosphotyrosine antibodies, only the phosphorylated receptors were isolated. Using this approach we made the two following key findings: (1) Both receptor species, alpha 2 beta 2 and alpha 2 beta, are present in live cells and in comparable amounts. This indicates that the alpha 2 beta form is not a degradation product of the alpha 2 beta 2 form artificially generated during receptor preparation. (2) The alpha 2 beta 2 species is the prevalently autophosphorylated form

  18. Ionizing radiation predisposes non-malignant human mammaryepithelial cells to undergo TGF beta-induced epithelial to mesenchymaltransition

    Energy Technology Data Exchange (ETDEWEB)

    Andarawewa, Kumari L.; Erickson, Anna C.; Chou, William S.; Costes, Sylvain; Gascard, Philippe; Mott, Joni D.; Bissell, Mina J.; Barcellos-Hoff, Mary Helen

    2007-04-06

    Transforming growth factor {beta}1 (TGF{beta}) is a tumor suppressor during the initial stage of tumorigenesis, but it can switch to a tumor promoter during neoplastic progression. Ionizing radiation (IR), both a carcinogen and a therapeutic agent, induces TGF{beta}, activation in vivo. We now show that IR sensitizes human mammary epithelial cells (HMEC) to undergo TGF{beta}-mediated epithelial to mesenchymal transition (EMT). Non-malignant HMEC (MCF10A, HMT3522 S1 and 184v) were irradiated with 2 Gy shortly after attachment in monolayer culture, or treated with a low concentration of TGF{beta} (0.4 ng/ml), or double-treated. All double-treated (IR+TGF{beta}) HMEC underwent a morphological shift from cuboidal to spindle-shaped. This phenotype was accompanied by decreased expression of epithelial markers E-cadherin, {beta}-catenin and ZO-1, remodeling of the actin cytoskeleton, and increased expression of mesenchymal markers N-cadherin, fibronectin and vimentin. Furthermore, double-treatment increased cell motility, promoted invasion and disrupted acinar morphogenesis of cells subsequently plated in Matrigel{trademark}. Neither radiation nor TGF{beta} alone elicited EMT, even though IR increased chronic TGF{beta} signaling and activity. Gene expression profiling revealed that double treated cells exhibit a specific 10-gene signature associated with Erk/MAPK signaling. We hypothesized that IR-induced MAPK activation primes non-malignant HMEC to undergo TGF{beta}-mediated EMT. Consistent with this, Erk phosphorylation were transiently induced by irradiation, persisted in irradiated cells treated with TGF{beta}, and treatment with U0126, a Mek inhibitor, blocked the EMT phenotype. Together, these data demonstrate that the interactions between radiation-induced signaling pathways elicit heritable phenotypes that could contribute to neoplastic progression.

  19. Isoreserpine promotes {beta}-catenin degradation via Siah-1 up-regulation in HCT116 colon cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Gwak, Jungsug; Song, Taeyun [PharmacoGenomics Research Center, Inje University, Busan 614-735 (Korea, Republic of); Song, Jie-Young; Yun, Yeon-Sook [Laboratory of Radiation Cancer Science, Korea Institute of Radiological and Medical Sciences, Seoul 139-706 (Korea, Republic of); Choi, Il-Whan [Department of Microbiology, Center for Viral Disease Research, Inje University College of Medicine, Busan 614-735 (Korea, Republic of); Jeong, Yongsu [Department of Genetic Engineering, and Graduate School of Biotechnology, Kyung Hee University, Yongin 446-701 (Korea, Republic of); Shin, Jae-Gook [PharmacoGenomics Research Center, Inje University, Busan 614-735 (Korea, Republic of); Department of Clinical Pharmacology, Inje University Busan Paik Hospital, Busan 614-735 (Korea, Republic of); Oh, Sangtaek, E-mail: ohsa@inje.ac.kr [PharmacoGenomics Research Center, Inje University, Busan 614-735 (Korea, Republic of)

    2009-09-25

    Aberrant accumulation of intracellular {beta}-catenin in intestinal epithelial cells is a frequent early event during the development of colon cancer. To identify small molecules that decrease the level of intracellular {beta}-catenin, we performed cell-based chemical screening using genetically engineered HEK293 reporter cells to detect compounds that inhibit TOPFlash reporter activity, which was stimulated by Wnt3a-conditioned medium. We found that isoreserpine promoted the degradation of intracellular {beta}-catenin by up-regulation of Siah-1 in HEK293 and HCT116 colon cancer cells. Moreover, isoreserpine repressed the expression of {beta}-catenin/T-cell factor (TCF)-dependent genes, such as cyclin D1 and c-myc, resulting in the suppression of HCT116 cell proliferation. Our findings suggest that isoreserpine can potentially be used as a chemotherapeutic agent against colon cancer.

  20. IKKβ inhibition prevents fat-induced beta cell dysfunction in vitro and in vivo in rodents.

    Science.gov (United States)

    Ivovic, Aleksandar; Oprescu, Andrei I; Koulajian, Khajag; Mori, Yusaku; Eversley, Judith A; Zhang, Liling; Nino-Fong, Rodolfo; Lewis, Gary F; Donath, Marc Y; Karin, Michael; Wheeler, Michael B; Ehses, Jan; Volchuk, Allen; Chan, Catherine B; Giacca, Adria

    2017-10-01

    We have previously shown that oxidative stress plays a causal role in beta cell dysfunction induced by fat. Here, we address whether the proinflammatory kinase inhibitor of (nuclear factor) κB kinase β (IKKβ), which is activated by oxidative stress, is also implicated. Fat (oleate or olive oil) was infused intravenously in Wistar rats for 48 h with or without the IKKβ inhibitor salicylate. Thereafter, beta cell function was evaluated in vivo using hyperglycaemic clamps or ex vivo in islets isolated from fat-treated rats. We also exposed rat islets to oleate in culture, with or without salicylate and 4(2'-aminoethyl)amino-1,8-dimethylimidazo(1,2-a)quinoxaline; BMS-345541 (BMS, another inhibitor of IKKβ) and evaluated beta cell function in vitro. Furthermore, oleate was infused in mice treated with BMS and in beta cell-specific Ikkb-null mice. 48 h infusion of fat impaired beta-cell function in vivo, assessed using the disposition index (DI), in rats (saline: 1.41 ± 0.13; oleate: 0.95 ± 0.11; olive oil [OLO]: 0.87 ± 0.15; p vivo (i.e., insulin secretion, units are pmol insulin islet -1  h -1 ) in rat islets (saline: 1.51 ± 0.13; oleate: 1.03 ± 0.10; OLO: 0.91 ± 0.13; p vivo and by salicylate in rat islets ex vivo (oleate + salicylate: 1.74 ± 0.31; OLO + salicylate: 1.54 ± 0.29). In cultured islets, 48 h exposure to oleate impaired beta-cell function ([in pmol insulin islet -1  h -1 ] control: 0.66 ± 0.12; oleate: 0.23 ± 0.03; p vivo ([in pmol insulin islet -1  h -1 ] control saline: 0.16 ± 0.02; control oleate: 0.10 ± 0.02; knockout oleate: 0.17 ± 0.04; p vivo (DI: control saline: 3.86 ± 0.40; control oleate: 1.95 ± 0.29; knockout oleate: 2.96 ± 0.24; p vivo and in vivo.

  1. The neurosurvival factor Humanin inhibits beta cell apoptosis via Stat3 activation and delays and ameliorates diabetes in NOD mice

    OpenAIRE

    Hoang, P. T.; Park, P.; Cobb, L. J.; Paharkova-Vatchkova, V.; Hakimi, M.; Cohen, P.; Lee, K.-W.

    2009-01-01

    Pancreatic beta cell apoptosis is important in the pathogenesis and potential treatment of Type 1 diabetes. We investigated whether Humanin, a recently described survival factor for neurons, could improve the survival of beta cells and delay or treat diabetes in the NOD model. Humanin reduced apoptosis induced by serum starvation in NIT-1 cells and decreased apoptosis induced by cytokine treatment. Humanin induced Stat3 and ERK phosphorylation over a 24 hour time course. Specific inhibition o...

  2. Creatine kinase BB and beta-2-microglobulin as markers of CNS metastases in patients with small-cell lung cancer

    DEFF Research Database (Denmark)

    Pedersen, A G; Bach, F W; Nissen, Mogens Holst

    1985-01-01

    Creatine kinase (CK) and its BB isoenzyme (CK-BB) were measured in CSF in 65 evaluable patients suspected of CNS metastases secondary to small-cell lung cancer (SCLC). In addition, CSF and plasma levels of beta-2-microglobulin (beta-2-m) were measured in a group of 73 evaluable patients. Of the 65...

  3. Thymosin beta-10 expression in melanoma cell lines and melanocytic lesions: a new progression marker for human cutaneous melanoma

    NARCIS (Netherlands)

    Weterman, M. A.; van Muijen, G. N.; Ruiter, D. J.; Bloemers, H. P.

    1993-01-01

    When screening a subtraction library for sequences that were specifically expressed in highly metastatic human melanoma cell lines, a cDNA clone was isolated encoding thymosin beta-10. We found that expression of thymosin beta-10 mRNA was associated with metastatic behavior of various human melanoma

  4. THE LINKAGE OF (1-3)-BETA-GLUCAN TO CHITIN DURING CELL-WALL ASSEMBLY IN SACCHAROMYCES-CEREVISIAE

    NARCIS (Netherlands)

    HARTLAND, RP; VERMEULEN, CA; KLIS, FM; SIETSMA, JH; WESSELS, JGH

    1994-01-01

    Pulse-chase experiments with [C-14]glucose demonstrated that in the cell wall of wild-type Saccharomyces cerevisiae alkali-soluble (1-3)-beta-glucan serves as a precursor for alkali-insoluble (1-3)-beta-glucan. The following observations support the notion that the insolubilization of the glucan is

  5. Significance of plasma transforming growth factor-beta levels in radiotherapy for non-small-cell lung cancer

    NARCIS (Netherlands)

    De Jaeger, K; Seppenwoolde, Y; Kampinga, HH; Belderbos, JSA; Lebesque, JV

    2004-01-01

    Purpose: In dose-escalation studies of radiotherapy (RT) for non-small-cell lung cancer (NSCLC), radiation pneumonitis (RP) is the most important dose-limiting complication. Transforming growth factor-beta1 (TGF-beta1) has been reported to be associated with the incidence of RP. It has been proposed

  6. p40 as a Basal Cell Marker in the Diagnosis of Prostate Glandular Proliferations: A Comparative Immunohistochemical Study with 34betaE12

    Directory of Open Access Journals (Sweden)

    Hermann Brustmann

    2015-01-01

    Full Text Available Immunohistochemistry is important for the accurate diagnosis of basal cells in atypical glandular proliferations of the prostate. p40, an isoform of p63, may be an adjunct to a marker panel in this setting. Biopsies of 68 patients were analyzed by immunohistochemistry using antibodies to 34betaE12 and p40. Basal cell staining was classified as negative, partial (<60%, or diffuse (≥60%; irregular staining was defined as discordant staining patterns. In acinar proliferations (N=41, partial staining for both markers was seen in 42%, and diffuse staining in 46% of reactive cases. An irregular reactivity was noted in one case only (2%. Finally, these lesions were signed out as benign. Acinar proliferations negative for both markers and limited amount of glands (≤4 were termed atypical small acinar proliferations (ASAP. Out of six PIN lesions two cases showed partial, three cases showed diffuse reactivity for both markers, and one case was stained irregular. All cases diagnosed as prostate carcinomas (N=20 had no evidence of basal cell staining for neither of the markers. p40 expression is closely correlated to 34betaE12 with respect to demonstration of basal cells of prostate glands and may provide further information on the dignity of glandular proliferations of the prostate.

  7. TGF-beta1 signaling plays a dominant role in the crosstalk between TGF-beta1 and the aryl hydrocarbon receptor ligand in prostate epithelial cells

    Czech Academy of Sciences Publication Activity Database

    Staršíchová, Andrea; Hrubá, E.; Slabáková, Eva; Pernicová, Zuzana; Procházková, Jiřina; Pěnčíková, K.; Šeda, Václav; Kabátková, Markéta; Vondráček, Jan; Kozubík, Alois; Machala, M.; Souček, Karel

    2012-01-01

    Roč. 24, č. 8 (2012), s. 1665-1676 ISSN 0898-6568 R&D Projects: GA ČR(CZ) GA310/07/0961 Institutional research plan: CEZ:AV0Z50040702 Keywords : transforming growth factor-beta * aryl hydrocarbon receptor ligand * prostate epithelial cells Subject RIV: BO - Biophysics Impact factor: 4.304, year: 2012

  8. Cytokines interleukin-1beta and tumor necrosis factor-alpha regulate different transcriptional and alternative splicing networks in primary beta-cells

    DEFF Research Database (Denmark)

    Ortis, Fernanda; Naamane, Najib; Flamez, Daisy

    2010-01-01

    OBJECTIVE: Cytokines contribute to pancreatic beta-cell death in type 1 diabetes. This effect is mediated by complex gene networks that remain to be characterized. We presently utilized array analysis to define the global expression pattern of genes, including spliced variants, modified by the cy...

  9. Dibenzocyclooctadiene lignans, gomisins J and N inhibit the Wnt/{beta}-catenin signaling pathway in HCT116 cells

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Kyungsu; Lee, Kyung-Mi; Yoo, Ji-Hye; Lee, Hee Ju [Functional Food Center, Korea Institute of Science and Technology, Gangneung 210-340 (Korea, Republic of); Kim, Chul Young [Functional Food Center, Korea Institute of Science and Technology, Gangneung 210-340 (Korea, Republic of); College of Pharmacy, Hanyang University, Ansan 426-791 (Korea, Republic of); Nho, Chu Won, E-mail: cwnho@kist.re.kr [Functional Food Center, Korea Institute of Science and Technology, Gangneung 210-340 (Korea, Republic of)

    2012-11-16

    Graphical abstract: Schematic diagram of the possible molecular mechanism underlying the inhibition of the Wnt/{beta}-catenin signaling pathway and the induction of G0/G1-phase arrest by gomisins J and N, derived from the fruits of S. chinensis, in HCT116 human colon cancer cells. Highlights: Black-Right-Pointing-Pointer Gomisins J and N inhibited Wnt/{beta}-catenin signaling pathway in HCT116 cells. Black-Right-Pointing-Pointer Gomisins J and N disrupted the binding of {beta}-catenin to specific DNA sequences, TBE. Black-Right-Pointing-Pointer Gomisins J and N inhibited the HCT116 cell proliferation through G0/G1 phase arrest. Black-Right-Pointing-Pointer Gomisins J and N inhibited the expression of Cyc D1, a Wnt/{beta}-catenin target gene. -- Abstract: Here, we report that gomisin J and gomisin N, dibenzocyclooctadiene type lignans isolated from Schisandra chinensis, inhibit Wnt/{beta}-catenin signaling in HCT116 cells. Gomisins J and N appear to inhibit Wnt/{beta}-catenin signaling by disrupting the interaction between {beta}-catenin and its specific target DNA sequences (TCF binding elements, TBE) rather than by altering the expression of the {beta}-catenin protein. Gomisins J and N inhibit HCT116 cell proliferation by arresting the cell cycle at the G0/G1 phase. The G0/G1 phase arrest induced by gomisins J and N appears to be caused by a decrease in the expression of Cyclin D1, a representative target gene of the Wnt/{beta}-catenin signaling pathway, as well as Cdk2, Cdk4, and E2F-1. Therefore, gomisins J and N, the novel Wnt/{beta}-catenin inhibitors discovered in this study, may serve as potential agents for the prevention and treatment of human colorectal cancers.

  10. The integrin alpha 6 beta 1 promotes the survival of metastatic human breast carcinoma cells in mice

    DEFF Research Database (Denmark)

    Wewer, U M; Shaw, L M; Albrechtsen, R

    1997-01-01

    The role of the integrin alpha 6 beta 1 in breast carcinoma progression was studied by targeted elimination of this integrin in MDA-MB-435 cells, a human breast carcinoma cell line that is highly metastatic in athymic mice. The strategy used is based on the finding that expression of a cytoplasmi...... in the liver after intrahepatic injection because of extensive apoptosis in the beta 4-delta CYT transfectants. These data suggest that a major function of the alpha 6 beta 1 integrin in breast carcinoma is to facilitate tumorigenesis and promote tumor cell survival in distant organs....

  11. Targeting dysfunctional beta-cell signaling for the potential treatment of type 1 diabetes mellitus.

    Science.gov (United States)

    Fenske, Rachel J; Kimple, Michelle E

    2018-03-01

    Since its discovery and purification by Frederick Banting in 1921, exogenous insulin has remained almost the sole therapy for type 1 diabetes mellitus. While insulin alleviates the primary dysfunction of the disease, many other aspects of the pathophysiology of type 1 diabetes mellitus are unaffected. Research aimed towards the discovery of novel type 1 diabetes mellitus therapeutics targeting different cell signaling pathways is gaining momentum. The focus of these efforts has been almost entirely on the impact of immunomodulatory drugs, particularly those that have already received FDA-approval for other autoimmune diseases. However, these drugs can often have severe side effects, while also putting already immunocompromised individuals at an increased risk for other infections. Potential therapeutic targets in the insulin-producing beta-cell have been largely ignored by the type 1 diabetes mellitus field, save the glucagon-like peptide 1 receptor. While there is preliminary evidence to support the clinical exploration of glucagon-like peptide 1 receptor-based drugs as type 1 diabetes mellitus adjuvant therapeutics, there is a vast space for other putative therapeutic targets to be explored. The alpha subunit of the heterotrimeric G z protein (Gα z ) has been shown to promote beta-cell inflammation, dysfunction, death, and failure to replicate in the context of diabetes in a number of mouse models. Genetic loss of Gα z or inhibition of the Gα z signaling pathway through dietary interventions is protective against the development of insulitis and hyperglycemia. The multifaceted effects of Gα z in regards to beta-cell health in the context of diabetes make it an ideal therapeutic target for further study. It is our belief that a low-risk, effective therapy for type 1 diabetes mellitus will involve a multidimensional approach targeting a number of regulatory systems, not the least of which is the insulin-producing beta-cell. Impact statement The expanding

  12. Electrospun Polyacrylonitrile-Based Nanofibers Maintain Embryonic Stem Cell Stemness via TGF-Beta Signaling.

    Science.gov (United States)

    Liu, Shih-Ping; Lin, Chen-Huan; Lin, Shao-Ji; Fu, Ru-Huei; Huang, Yu-Chuen; Chen, Shih-Yin; Lin, Shinn-Zong; Hsu, Chung Y; Shyu, Woei-Cherng

    2016-04-01

    Embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) are capable of self-renewal and differentiation into any cell type, thus making them the focus of many clinical application studies. Culturing ESCs on mouse embryonic fibroblast-derived and cell-based feeder layers to maintain pluripotency is a standard laboratory procedure. However, xenogeneic contamination and the large amount of time required for feeder cell preparation are two challenges that encourage the use of a murine-based feeder layer. A novel biomaterial is required to replace the current cell-based feeder system. Toward this goal, we applied a combination of biocompatible polyacrylonitrile (PAN) and electrospinning technology to establish a non-cell-based feeder layer. According to results from stem cell marker staining, scanning electron microscopy, and embryoid body formation tests, optimal ESC stemness and pluripotency were noted in three electrospun groups (2, 4, and 8 minutes), with the longer electrospinning times producing higher feeder-layer densities. KEGG pathway microarray results identified TGF-beta signaling as one of the major deregulatory pathways on electrospun-based feeder layers. Western blot data indicate significant increases in TGF-beta receptor II, phosphorylated Smad3, and Nanog protein levels in the 4- and 8-minute electrospun-based feeder layer groups compared to the non-feeder layer group. Combined, the data suggest that electrospun-based feeder layers are good candidates for maintaining ESC and iPSC pluripotency in clinical applications.

  13. Failure of anti-T-cell receptor V beta antibodies to consistently identify a malignant T-cell clone in Sézary syndrome.

    Science.gov (United States)

    Bigler, R D; Boselli, C M; Foley, B; Vonderheid, E C

    1996-11-01

    Monoclonal antibodies (MAbs) reacting with the human T cell receptor (TCR) V beta or V alpha region have been shown to be almost as specific as a private idiotypic MAb in identifying T cell clones. When available, V beta-specific MAbs offer the ease of immunofluorescence analysis to identify and quantitate expanded malignant or nonmalignant T cell populations without requiring polymerase chain reaction (PCR) technology to evaluate expression of V beta gene families. The V beta expression of peripheral blood lymphocytes from twenty-three consecutive patients with Sézary syndrome has been analyzed by reverse transcriptase (RT)-PCR. Ten patients had malignant T cell clones that expressed a TCR V beta corresponding to a commercially available anti-V beta antibody. Immunofluorescence staining with anti-V beta MAbs showed a direct correlation with RT-PCR results in seven of ten patients. No false positive reactivity was noted on immunofluorescence staining with any MAb. Cells from three patients, however, did not react with the corresponding anti-V beta MAb. These three cases expressed a TCR V beta from gene families containing a single member, ie, V beta 14, V beta 18, and V beta 20, yet MAbs reported to be specific for these regions failed to react with the T cell clone from these patients. Sequencing of the PCR product in these cases confirmed the RT-PCR results. Cells from two patients expressed a TCR using V beta 5.1-D beta 1.1 genes with different J-C segments. One patient's cells reacted with an anti-V beta 5.1 MAb (LC4) whereas the other patient's cells bound one-tenth the amount of this same MAb. These results indicate that currently available anti-TCR V region MAbs may not react consistently with T cell clones expressing the corresponding V region or may react with a low affinity making detection difficult. Differences in the J-C junction or in CDR3 may influence the binding of these MAbs. Until the false negative rate is reduced and the fine specificity and

  14. Characterization of GLP-1 effects on beta-cell function after meal ingestion in humans

    DEFF Research Database (Denmark)

    Ahrén, Bo; Holst, Jens Juul; Mari, Andrea

    2003-01-01

    OBJECTIVE: Glucagon-like peptide 1 (GLP-1) is an incretin that augments insulin secretion after meal intake and is developed for treatment of type 2 diabetes. As a novel therapeutic agent, characteristics of its beta-cell effects are important to establish. Previously, beta-cell effects of GLP-1...... have been characterized in humans during graded intravenous infusions of glucose, whereas its effects after more physiological stimuli, like meal intake, are not known. RESEARCH DESIGN AND METHODS: Eight women (aged 69 years, fasting glucose 3.7-10.3 mmol/l, BMI 22.4-43.9 kg/m(2)) who had fasted...... meal augments insulin secretion in humans by a dose...

  15. Tumor associated macrophages protect colon cancer cells from TRAIL-induced apoptosis through IL-1beta-dependent stabilization of Snail in tumor cells.

    Directory of Open Access Journals (Sweden)

    Pawan Kaler

    2010-07-01

    Full Text Available We recently reported that colon tumor cells stimulate macrophages to release IL-1beta, which in turn inactivates GSK3beta and enhances Wnt signaling in colon cancer cells, generating a self-amplifying loop that promotes the growth of tumor cells.Here we describe that macrophages protect HCT116 and Hke-3 colon cancer cells from TRAIL-induced apoptosis. Inactivation of IL-1beta by neutralizing IL-1beta antibody, or silencing of IL-1beta in macrophages inhibited their ability to counter TRAIL-induced apoptosis. Accordingly, IL-1beta was sufficient to inhibit TRAIL-induced apoptosis. TRAIL-induced collapse of the mitochondrial membrane potential (Delta psi and activation of caspases were prevented by macrophages or by recombinant IL-1beta. Pharmacological inhibition of IL-1beta release from macrophages by vitamin D(3, a potent chemopreventive agent for colorectal cancer, restored the ability of TRAIL to induce apoptosis of tumor cells cultured with macrophages. Macrophages and IL-1beta failed to inhibit TRAIL-induced apoptosis in HCT116 cells expressing dnIkappaB, dnAKT or dnTCF4, confirming that they oppose TRAIL-induced cell death through induction of Wnt signaling in tumor cells. We showed that macrophages and IL-1beta stabilized Snail in tumor cells in an NF-kappaB/Wnt dependent manner and that Snail deficient tumor cells were not protected from TRAIL-induced apoptosis by macrophages or by IL-1beta, demonstrating a crucial role of Snail in the resistance of tumor cells to TRAIL.We have identified a positive feedback loop between tumor cells and macrophages that propagates the growth and promotes the survival of colon cancer cells: tumor cells stimulate macrophages to secrete IL-1beta, which in turn, promotes Wnt signaling and stabilizes Snail in tumor cells, conferring resistance to TRAIL. Vitamin D(3 halts this amplifying loop by interfering with the release of IL-1beta from macrophages. Accordingly, vitamin D(3 sensitizes tumor cells to TRAIL

  16. The transforming growth factor-betas: multifaceted regulators of the development and maintenance of skeletal muscles, motoneurons and Schwann cells.

    Science.gov (United States)

    McLennan, Ian S; Koishi, Kyoko

    2002-01-01

    This review discusses the roles of the transforming growth factor-betas (TGF-betas) as part of a complex network that regulates the development and maintenance of the neuromuscular system. The actions of the TGF-betas often vary depending on which other growth factors are present, making it difficult to extrapolate results from in vitro experiments to the in vivo situation. A new approach has therefore been needed to understand the physiological functions of the TGF-betas. The behaviours (proliferation, fusion, apoptosis) of many of the cells in the neuromuscular system have a complex pattern which varies in space and time. The actions of growth factors in this system can thus be deduced based on how well their pattern of expression correlates with known cellular behaviours. Hypotheses based on this molecular anatomical evidence can then be further tested with genetically modified mice. From this type of evidence, we suggest that: (1) TGF-beta1 is an autocrine regulator of Schwann cells; (2) maternally-derived TGF-beta1 helps to suppress self and maternal immune attack; (3) TGF-beta2 regulates when and where myoblasts fuse to myotubes; (4) motoneuron survival is regulated by multiple sources of TGF-betas, with TGF-beta2 being the more important isoform. The concept of TGF-beta1 as a regulator of secondary myotube formation is not supported by either the location of the TGF-beta1 in developing muscles or by the phenotype of TGF-beta1-/- mice. The review concludes with a discussion of whether all of these of postulated functions can occur independently of each other, within the confines of the neuromuscular system.

  17. Reference intervals for glucose, beta-cell polypeptides and counterregulatory factors during prolonged fasting

    DEFF Research Database (Denmark)

    Højlund, Kurt; Wildner-Christensen, M; Eshøj, O

    2001-01-01

    To establish reference intervals for the pancreatic beta-cell response and the counterregulatory hormone response to prolonged fasting, we studied 33 healthy subjects (16 males, 17 females) during a 72-h fast. Glucose, insulin, C-peptide, and proinsulin levels decreased (P ... of counterregulatory factors increased during the fast [P fasting (P ... decreased from the second to third day of fasting (P = 0.03). Males had higher glucose and glucagon levels and lower FFA levels during the fast (P

  18. Expression of a TGF-{beta} regulated cyclin-dependent kinase inhibitor in normal and immortalized airway epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Tierney, L.A.; Bloomfield, C.; Johnson, N.F. [and others

    1995-12-01

    Tumors arising from epithelial cells, including lung cancers are frequently resistant to factors that regulate growth and differentiation in normal in normal cells. Once such factor is transforming growth factor-{Beta} (TGF-{Beta}). Escape from the growth-inhibitory effects of TGF-{Beta} is thought to be a key step in the transformation of airway epithelial cells. most lung cancer cell lines require serum for growth. In contrast, normal human bronchial epithelial (NHBE) cells are exquisitely sensitive to growth-inhibitory and differentiating effects of TGF-{Beta}. The recent identification of a novel cyclin-dependent kinase inhibitor, p15{sup INK4B}, which is regulated by TGF-{Beta}, suggests a mechanism by which TGF-{Beta} mediates growth arrest in NHBE cells. The purpose of this study was two-fold: (1) to determine if p15{sup INK4B} is induced by TGF-{Beta} in NHBE cells or immortalized bronchial epithelial (R.1) cells and if that induction corresponds to a G1/S cell-cycle arrest; (2) to determine the temporal relationship between p15{sup INK4B} induction, cell-cycle arrest, and the phosphorylation state of the pRB because it is thought that p15{sup INK4B} acts indirectly by preventing phosphorylation of the RB gene product. In this study, expression of p15{sup INK4B} was examined in NHBE cells and R.1 cells at different time intervals following TGF-{Beta} treatment. The expression of this kinase inhibitor and its relationship to the cell and the pRb phosphorylation state were examined in cells that were both sensitive (NHBE) and resistant (R.1) to the effects of TGF-{Beta}. These results suggest that the cyclin-dependent kinase inhibitor, p15{sup INK4B}, is involved in airway epithelial cell differentiation and that loss or reduction of expression plays a role in the resistance of transformed or neoplastic cells to the growth-inhibitory effects of TGF-{Beta}.

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

    Directory of Open Access Journals (Sweden)

    Samira Missaoui

    2014-01-01

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

  20. Beta-endorphin cell therapy for cancer prevention.

    Science.gov (United States)

    Zhang, Changqing; Murugan, Sengottuvelan; Boyadjieva, Nadka; Jabbar, Shaima; Shrivastava, Pallavi; Sarkar, Dipak K

    2015-01-01

    β-Endorphin (BEP)-producing neuron in the hypothalamus plays a key role in bringing the stress axis to a state of homeostasis and maintaining body immune defense system. Long-term delivery of BEP to obtain beneficial effect on chemoprevention is challenging, as the peptides rapidly develop tolerance. Using rats as animal models, we show here that transplantation of BEP neurons into the hypothalamus suppressed carcinogens- and hormone-induced cancers in various tissues and prevented growth and metastasis of established tumors via activation of innate immune functions. In addition, we show that intracerebroventricular administration of nanosphere-attached dibutyryl cyclic adenosine monophosphate (dbcAMP) increased the number of BEP neurons in the hypothalamus, reduced the stress response, enhanced the innate immune function, and prevented tumor cell growth, progression, and metastasis. BEP neuronal supplementation did not produce any deleterious effects on general health but was beneficial in suppressing age-induced alterations in physical activity, metabolic, and immune functions. We conclude that the neuroimmune system has significant control over cancer growth and progression, and that activation of the neuroimmune system via BEP neuronal supplementation/induction may have therapeutic value for cancer prevention and improvement of general health. ©2014 American Association for Cancer Research.

  1. Characterization of V beta-bearing cells in athymic (nu/nu) mice suggests an extrathymic pathway for T cell differentiation.

    Science.gov (United States)

    Rocha, B

    1990-04-01

    In the present article, the expression of the T cell receptor (TcR) beta chain and other T cell molecules was evaluated in surface immunoglobulin-negative spleen cell populations of young and old BALB/c and C57BL/6 nude mice, using a panel of monoclonal antibodies. The results obtained show that in young nude mice, most Thy-1high cells do not express other T cell markers. These mice have, however, a sizable population of Thy-1low cells with the same phenotype of alpha/beta+, CD4-CD8- thymocytes or MRL/lpr peripheral T cells, expressing predominantly genes of the V beta 8 family. The evolution of alpha/beta+ cells in aging nudes is strongly suggestive of an extrathymic pathway of differentiation of these cells since (a) the acquisition of high density TcR and CD3, as well as Thy-1 or CD4CD8 antigens at the cell surface of nude V beta+ T cells is not simultaneous; (b) alpha/beta+ cells in nude mice co-express other T cell markers at random and, even in old mice, they never completely resemble to the predominant high Thy-1+ CD3+ TcR alpha/beta+, CD4+CD8+ cells of euthymic controls; and (c) BALB/c nude T cells express V beta 11 genes, that are deleted in euthymic BALB/c mice. This latter finding may also indicate differences in the mechanisms of selection of T cells specificities in the thymus vs. the peripheral pools.

  2. Snail/beta-catenin signaling protects breast cancer cells from hypoxia attack

    Energy Technology Data Exchange (ETDEWEB)

    Scherbakov, Alexander M., E-mail: alex.scherbakov@gmail.com [Laboratory of Clinical Biochemistry, Institute of Clinical Oncology, N.N. Blokhin Cancer Research Centre, Kashirskoye sh. 24, Moscow 115478 (Russian Federation); Stefanova, Lidia B.; Sorokin, Danila V.; Semina, Svetlana E. [Laboratory of Molecular Endocrinology, Institute of Carcinogenesis, N.N. Blokhin Cancer Research Centre, Kashirskoye sh. 24, Moscow 115478 (Russian Federation); Berstein, Lev M. [Laboratory of Oncoendocrinology, N.N. Petrov Research Institute of Oncology, St. Petersburg 197758 (Russian Federation); Krasil’nikov, Mikhail A. [Laboratory of Molecular Endocrinology, Institute of Carcinogenesis, N.N. Blokhin Cancer Research Centre, Kashirskoye sh. 24, Moscow 115478 (Russian Federation)

    2013-12-10

    The tolerance of cancer cells to hypoxia depends on the combination of different factors – from increase of glycolysis (Warburg Effect) to activation of intracellular growth/apoptotic pathways. Less is known about the influence of epithelial–mesenchymal transition (EMT) and EMT-associated pathways on the cell sensitivity to hypoxia. The aim of this study was to explore the role of Snail signaling, one of the key EMT pathways, in the mediating of hypoxia response and regulation of cell sensitivity to hypoxia, using as a model in vitro cultured breast cancer cells. Earlier we have shown that estrogen-independent HBL-100 breast cancer cells differ from estrogen-dependent MCF-7 cells with increased expression of Snail1, and demonstrated Snail1 involvement into formation of hormone-resistant phenotype. Because Snail1 belongs to hypoxia-activated proteins, here we studied the influence of Snail1 signaling on the cell tolerance to hypoxia. We found that Snail1-enriched HBL-100 cells were less sensitive to hypoxia-induced growth suppression if compared with MCF-7 line (31% MCF-7 vs. 71% HBL-100 cell viability after 1% O{sub 2} atmosphere for 3 days). Snail1 knock-down enhanced the hypoxia-induced inhibition of cell proliferation giving the direct evidence of Snail1 involvement into cell protection from hypoxia attack. The protective effect of Snail1 was shown to be mediated, at least in a part, via beta-catenin which positively regulated expression of HIF-1-dependent genes. Finally, we found that cell tolerance to hypoxia was accompanied with the failure in the phosphorylation of AMPK – the key energy sensor, and demonstrated an inverse relationship between AMPK and Snail/beta-catenin signaling. Totally, our data show that Snail1 and beta-catenin, besides association with loss of hormone dependence, protect cancer cells from hypoxia and may serve as an important target in the treatment of breast cancer. Moreover, we suggest that the level of these proteins as well

  3. Mutations in alpha- and beta-tubulin affect spindle formation in Chinese hamster ovary cells.

    Science.gov (United States)

    Abraham, I; Marcus, M; Cabral, F; Gottesman, M M

    1983-10-01

    Two Chinese hamster ovary cell lines with mutated beta-tubulins (Grs-2 and Cmd-4) and one that has a mutation in alpha-tubulin (Tax-1) are temperature sensitive for growth at 40.5 degrees C. To determine the functional defect in these mutant cells at the nonpermissive temperature, they were characterized with respect to cell cycle parameters and microtubule organization and function after relatively short periods at 40.5 degrees C. At the nonpermissive temperature all the mutants had normal appearing cytoplasmic microtubules. Premature chromosome condensation analysis failed to show any discrete step in the interphase cell cycle in which these mutants are arrested. These cells, however, show several defects at the nonpermissive temperature that appear related to the function of microtubules during mitosis. Time-lapse studies showed that mitosis was lengthened in the three mutant lines at 40.5 degrees C as compared with the wild-type cells at this temperature, resulting in a higher proportion of cells in mitosis after temperature shift. There was also a large increase in multinucleated cells in mutant populations after incubation at the nonpermissive temperature. Immunofluorescent studies using a monoclonal anti--alpha-tubulin antibody showed that the mutant cells had a high proportion of abnormal spindles at the nonpermissive temperature. The two altered beta-tubulins and the altered alpha-tubulin all were found to cause a similar phenotype at the high temperature that results in mitotic delay, defective cytokinesis, multinucleation, and ultimately, cell death. We conclude that spindle formation is the limiting microtubule function in these mutant cell lines at the nonpermissive temperature and that these cell lines will be of value for the study of the precise role of tubulin in mammalian spindle formation.

  4. Differential expression of estrogen receptors alpha and beta mRNA during differentiation of human osteoblast SV-HFO cells

    NARCIS (Netherlands)

    J. Arts (Janine); J.M.M.F. Janssen (Josine); J.A. Gustafsson (Jan-Ake); C.W.G.M. Löwik (Clemens); H.A.P. Pols (Huib); J.P.T.M. van Leeuwen (Hans); G.G.J.M. Kuiper (George)

    1997-01-01

    textabstractEstrogens have been shown to be essential for maintaining a sufficiently high bone mineral density and ER alpha expression has been demonstrated in bone cells. Recently, a novel estrogen receptor, estrogen receptor beta (ERbeta) has been identified. Here

  5. Trichostatin A inhibits beta-casein expression in mammary epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Pujuguet, Philippe; Radisky, Derek; Levy, Dinah; Lacza, Charlemagne; Bissell, Mina J.

    2002-02-22

    Many aspects of cellular behavior are affected by information derived from association of the extracellular matrix (ECM) and with cell membrane receptors. When cultured in the presence of laminin-containing ECM and prolactin (Prl), normal mammary epithelial cells express the milk protein beta-casein. Previously, we defined the minimal ECM- and Prl-responsive enhancer element BCE-1 from the upstream region of the beta-casein gene. We also found that BCE-1 was only active when stably integrated into chromatin, and that trichostatin A (TSA), a reagent that leads to alterations in chromatin structure, was able to activate the integrated enhancer element. We now show that endogenous b-casein gene, which is controlled by a genetic assembly that is highly similar to that of BCE-1 and which is also activated by incubation in ECM and Prl, is instead inhibited by TSA. We provide evidence that the differing response of b-casein and BCE-1 to TSA is neither due to an unusual effect of TSA on mammary epithelial cells, nor to secondary consequences from the expression of a separate gene, nor to a particular property of the BCE-1 construct. As a component of this investigation, we also showed that ECM could mediate rapid histone deacetylation in mammary epithelial cells. These results are discussed in combination with previous work showing that TSA mediates the differentiation of many types of cancer cells but inhibits differentiation of some nonmalignant cell types.

  6. GeneSpeed Beta Cell: An Online Genomics Data Repository and Analysis Resource Tailored for the Islet Cell Biologist

    Directory of Open Access Journals (Sweden)

    Nayeem Quayum

    2008-01-01

    Full Text Available Objective. We here describe the development of a freely available online database resource, GeneSpeed Beta Cell, which has been created for the pancreatic islet and pancreatic developmental biology investigator community. Research Design and Methods. We have developed GeneSpeed Beta Cell as a separate component of the GeneSpeed database, providing a genomics-type data repository of pancreas and islet-relevant datasets interlinked with the domain-oriented GeneSpeed database. Results. GeneSpeed Beta Cell allows the query of multiple published and unpublished select genomics datasets in a simultaneous fashion (multiexperiment viewing and is capable of defining intersection results from precomputed analysis of such datasets (multidimensional querying. Combined with the protein-domain categorization/assembly toolbox provided by the GeneSpeed database, the user is able to define spatial expression constraints of select gene lists in a relatively rigid fashion within the pancreatic expression space. We provide several demonstration case studies of relevance to islet cell biology and development of the pancreas that provide novel insight into islet biology. Conclusions. The combination of an exhaustive domain-based compilation of the transcriptome with gene array data of interest to the islet biologist affords novel methods for multidimensional querying between individual datasets in a rapid fashion, presently not available elsewhere.

  7. Chaperones ameliorate beta cell dysfunction associated with human islet amyloid polypeptide overexpression.

    Directory of Open Access Journals (Sweden)

    Lisa Cadavez

    Full Text Available In type 2 diabetes, beta-cell dysfunction is thought to be due to several causes, one being the formation of toxic protein aggregates called islet amyloid, formed by accumulations of misfolded human islet amyloid polypeptide (hIAPP. The process of hIAPP misfolding and aggregation is one of the factors that may activate the unfolded protein response (UPR, perturbing endoplasmic reticulum (ER homeostasis. Molecular chaperones have been described to be important in regulating ER response to ER stress. In the present work, we evaluate the role of chaperones in a stressed cellular model of hIAPP overexpression. A rat pancreatic beta-cell line expressing hIAPP exposed to thapsigargin or treated with high glucose and palmitic acid, both of which are known ER stress inducers, showed an increase in ER stress genes when compared to INS1E cells expressing rat IAPP or INS1E control cells. Treatment with molecular chaperone glucose-regulated protein 78 kDa (GRP78, also known as BiP or protein disulfite isomerase (PDI, and chemical chaperones taurine-conjugated ursodeoxycholic acid (TUDCA or 4-phenylbutyrate (PBA, alleviated ER stress and increased insulin secretion in hIAPP-expressing cells. Our results suggest that the overexpression of hIAPP induces a stronger response of ER stress markers. Moreover, endogenous and chemical chaperones are able to ameliorate induced ER stress and increase insulin secretion, suggesting that improving chaperone capacity can play an important role in improving beta-cell function in type 2 diabetes.

  8. The Herbal Medicine Cordyceps sinensis Protects Pancreatic Beta Cells from Streptozotocin-Induced Endoplasmic Reticulum Stress.

    Science.gov (United States)

    Liu, Hong; Cao, Diyong; Liu, Hua; Liu, Xinghai; Mai, Wenli; Lan, Haitao; Huo, Wen; Zheng, Qian

    2016-08-01

    Our previous work found that Cordyceps sinensis (CS) improves the activity and secretory function of pancreatic islet beta cells. The objective was to observe a further possible role of CS in the protection of insulin-secreting cells. A rat model of type 2 diabetes mellitus was developed with streptozotocin (STZ) and a high-energy fat diet (HFD). CS was administered in the successful model of rats with type 2 diabetes. After 4 weeks, the biochemistry index of blood samples was measured, and pathologic observation was performed by immunohistochemistry. In the rats with type 2 diabetes induced by a HFD and STZ, the levels of fasting blood glucose and fasting insulin were elevated, and the insulin sensitivity index was decreased. Pathologic examination found an increased number of apoptotic cells, an elevated protein expression of pro-apoptotic C/EBP homologous protein (CHOP) and an increased c-Jun level by means of JNK phosphorylation, responsive to the endoplasmic reticulum stress of islet beta cells. With treatment by CS for 4 weeks, the elevated levels of both fasting blood glucose and fasting insulin in the rats with type 2 diabetes were significantly lower, and the decreased insulin sensitivity index was reversed. Compared to the control rats with type 2 diabetes, CS application significantly reduced the number of apoptotic cells and decreased protein expression of both CHOP and c-Jun. The herbal compound CS could protect pancreatic beta cells from the pro-apoptotic endoplasmic reticulum stress induced by HFD-STZ. This suggests an alternative approach to treating type 2 diabetes. Copyright © 2016 Canadian Diabetes Association. Published by Elsevier Inc. All rights reserved.

  9. Exploring the cell: Sodium (beta-alumina) cupric chloride - Aluminum chloride - Sodium chloride between 136 and 200 C

    Science.gov (United States)

    Miller, R. O.

    1975-01-01

    Experiments were done with a molten-salt catholyte (initially CuCl2 in AlCl3-NaCl) separated from molten Na by beta alumina. The open-circuit reduction potentials were 4.3 and 3 volts for Cu++ and Cu+, respectively. High polarization and nonrechargeability characterized the cell's operation. The cell's ohmic resistance during discharge was higher than what would be expected from only the ionic resistance of the beta-alumina.

  10. CISH has no non-redundant functions in glucose homeostasis or beta cell proliferation during pregnancy in mice.

    Science.gov (United States)

    Jiao, Yang; Rieck, Sebastian; Le Lay, John; Kaestner, Klaus H

    2013-11-01

    Increased beta cell proliferation during pregnancy is mediated by the Janus kinase 2/signal transducer and activator of transcription 5 (JAK2/STAT5) signalling pathway in response to increased lactogen levels. Activation of the pathway leads to transcriptional upregulation of Cish (encoding cytokine-inducible SH2 domain-containing protein), a member of the suppressor of cytokine signalling (SOCS) family of genes, forming a negative-feedback loop. Here, we examined whether conditional gene ablation of Cish in the pancreas improves beta cell proliferation and beta cell function during pregnancy in mice. We derived mice with a novel, conditional loxP allele for Cish. Pancreas-specific ablation of Cish was achieved by crossing Cish (loxP/loxP) mice with Pdx1-Cre (Early) mice. Beta cell proliferation was quantified by BrdU labelling. Glucose homeostasis was examined with glucose tolerance tests and determination of plasma insulin levels. The expression of other Socs genes and target genes of p-STAT5 related to beta cell function and beta cell proliferation was determined by quantitative PCR. There was no difference in beta cell proliferation or glucose homeostasis between the Cish mutant group and the control group. The p-STAT5 protein level was the same in Cish mutant and control mice. Socs2 gene expression was higher in Cish mutant than control mice at pregnancy day 9.5. The expression of other Socs genes was the same between control and mutant mice. Our results show that CISH has no non-redundant functions in beta cell proliferation or glucose homeostasis during pregnancy in mice. Socs2 might compensate for the loss of Cish during pregnancy.

  11. 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....

  12. New approach to beta cell function screening by nitric oxide assessment of obese individuals at the population level

    OpenAIRE

    Chaim, Elinton Adami; Gobato, Renata Cristina

    2012-01-01

    Elinton Adami Chaim, Renata Cristina GobatoUniversity of Campinas (UNICAMP), Faculty of Medical Sciences, Department of Surgery, Cidade Universitária Zeferino Vaz, Barão Geraldo, BrazilBackground: Approximately 27% of Americans today are obese, and this condition increases the prevalence of metabolic syndrome and diabetes. The UK Prospective Diabetes Study suggests that loss of beta cell function can begin at least 10 years before diagnosis, and mean beta cell function i...

  13. Autocrine production of beta-chemokines protects CMV-Specific CD4 T cells from HIV infection.

    Directory of Open Access Journals (Sweden)

    Joseph P Casazza

    2009-10-01

    Full Text Available Induction of a functional subset of HIV-specific CD4+ T cells that is resistant to HIV infection could enhance immune protection and decrease the rate of HIV disease progression. CMV-specific CD4+ T cells, which are less frequently infected than HIV-specific CD4+ T cells, are a model for such an effect. To determine the mechanism of this protection, we compared the functional response of HIV gag-specific and CMV pp65-specific CD4+ T cells in individuals co-infected with CMV and HIV. We found that CMV-specific CD4+ T cells rapidly up-regulated production of MIP-1alpha and MIP-1beta mRNA, resulting in a rapid increase in production of MIP-1alpha and MIP-1beta after cognate antigen stimulation. Production of beta-chemokines was associated with maturational phenotype and was rarely seen in HIV-specific CD4+ T cells. To test whether production of beta-chemokines by CD4+ T cells lowers their susceptibility to HIV infection, we measured cell-associated Gag DNA to assess the in vivo infection history of CMV-specific CD4+ T cells. We found that CMV-specific CD4+ T cells which produced MIP-1beta contained 10 times less Gag DNA than did those which failed to produce MIP-1beta. These data suggest that CD4+ T cells which produce MIP-1alpha and MIP-1beta bind these chemokines in an autocrine fashion which decreases the risk of in vivo HIV infection.

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

    Science.gov (United States)

    Ghosal, Abhisek; Sekar, Thillai V.

    2014-01-01

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

  15. Antioxidant and regulatory role of mitochondrial uncoupling protein UCP2 in pancreatic beta-cells

    Czech Academy of Sciences Publication Activity Database

    Ježek, Petr; Olejár, Tomáš; Smolková, Katarína; Ježek, Jan; Dlasková, Andrea; Plecitá-Hlavatá, Lydie; Zelenka, Jaroslav; Špaček, Tomáš; Engstová, Hana; Reguera Pajuelo, David; Jabůrek, Martin

    2014-01-01

    Roč. 63, Suppl.1 (2014), S73-S91 ISSN 0862-8408 R&D Projects: GA ČR(CZ) GAP302/10/0346; GA ČR(CZ) GAP305/12/1247; GA ČR(CZ) GPP304/10/P204; GA MŠk(CZ) EE2.3.30.0025 Institutional support: RVO:67985823 Keywords : mitochondria * uncoupling protein UCP2 * pancreatic beta-cells * reactive oxygen species * glucose-stimulated insulin secretion Subject RIV: EA - Cell Biology Impact factor: 1.293, year: 2014

  16. Pulsed hydrogen-deuterium exchange mass spectrometry probes conformational changes in amyloid beta (Aβ) peptide aggregation.

    Science.gov (United States)

    Zhang, Ying; Rempel, Don L; Zhang, Jun; Sharma, Anuj K; Mirica, Liviu M; Gross, Michael L

    2013-09-03

    Probing the conformational changes of amyloid beta (Aβ) peptide aggregation is challenging owing to the vast heterogeneity of the resulting soluble aggregates. To investigate the formation of these aggregates in solution, we designed an MS-based biophysical approach and applied it to the formation of soluble aggregates of the Aβ42 peptide, the proposed causative agent in Alzheimer's disease. The approach incorporates pulsed hydrogen-deuterium exchange coupled with MS analysis. The combined approach provides evidence for a self-catalyzed aggregation with a lag phase, as observed previously by fluorescence methods. Unlike those approaches, pulsed hydrogen-deuterium exchange does not require modified Aβ42 (e.g., labeling with a fluorophore). Furthermore, the approach reveals that the center region of Aβ42 is first to aggregate, followed by the C and N termini. We also found that the lag phase in the aggregation of soluble species is affected by temperature and Cu(2+) ions. This MS approach has sufficient structural resolution to allow interrogation of Aβ aggregation in physiologically relevant environments. This platform should be generally useful for investigating the aggregation of other amyloid-forming proteins and neurotoxic soluble peptide aggregates.

  17. Prognostic value of alpha 6 beta 4 integrin expression in breast carcinomas is affected by laminin production from tumor cells.

    Science.gov (United States)

    Tagliabue, E; Ghirelli, C; Squicciarini, P; Aiello, P; Colnaghi, M I; Ménard, S

    1998-02-01

    Immunocytochemical analysis of breast carcinoma specimens for alpha 6 beta 4 integrin expression and other different pathobiological markers revealed beta 4 integrin subunit expression in 36 of 80 cases analyzed and a significant association only with alpha 6 integrin subunit expression (P laminin production (P = 0.01) by tumor cells. Survival analysis indicated that beta 4 and alpha 6 expression are associated with poor prognosis (P = 0.02), whereas laminin production showed only borderline association (P = 0.06). However, analysis of disease outcome in relation to expression of both alpha 6 beta 4 and laminin indicated best outcomes for patients with tumors producing laminin but not expressing alpha 6 beta 4 integrin, whereas worst outcomes were observed for alpha 6 beta 4- and laminin-positive tumors, indicating that alpha 6 beta 4 expression was associated with prognosis, mainly in the laminin-producing tumor subset. These data indicate that the prognostic value of alpha 6 beta 4 integrin expression is affected by laminin production from tumor cells and suggest that interaction between these two molecules mediates distinct signals that are important for tumor progression.

  18. Interferon-beta specific T cells are associated with the development of neutralizing antibodies in interferon-beta treated multiple sclerosis patients.

    Science.gov (United States)

    Kalluri, Sudhakar Reddy; Grummel, Verena; Hracsko, Zsuzsanna; Pongratz, Viola; Pernpeintner, Verena; Gasperi, Christiane; Buck, Dorothea; Hemmer, Bernhard

    2018-03-01

    Beta-interferons are still among the most commonly used drugs to treat Multiple Sclerosis (MS). The use of beta-interferons is limited by the development of anti-drug antibodies (ADA), which may abrogate the treatment effect of the drug. Although the antibody response has been well studied, little is known about the T cell response to interferon-beta (IFN-β). We investigated T cell responses in four treatment naïve MS patients and twenty-three patients treated with IFN-β who had or had not developed ADA to IFN-β. T cell responses were determined by split-well and primary proliferation assays against different IFN-β protein preparations and a set of overlapping peptides covering the full sequence of IFN-β. T cell responses to IFN-β were observed in all donors. ADA positive patients showed higher T cell responses to IFN-β protein than ADA negative patients and untreated controls. We identified two immunodominant regions; T cell responses to IFN-β 1-40 were observed in all patients independent of ADA status, while T cell responses to IFN-β 125-159 were stronger in ADA positive than ADA negative patients. IFN-β specific T cell responses were HLA class II restricted and in ADA positive patients skewed towards a Th2 phenotype. In IFN-β treated patients we observed a correlation between IFN-β specific T cell responses, serum ADA titer and loss of biological activity of IFN-β treatment. Our studies demonstrate the occurrence of an antigen specific HLA class II restricted Th2 T cell response associated with the development of ADA in IFN-β treated patients. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Monte Carlo investigation of single cell beta dosimetry for intraperitoneal radionuclide therapy

    International Nuclear Information System (INIS)

    Syme, A M; Kirkby, C; Riauka, T A; Fallone, B G; McQuarrie, S A

    2004-01-01

    Single event spectra for five beta-emitting radionuclides (Lu-177, Cu-67, Re-186, Re-188, Y-90) were calculated for single cells from two source geometries. The first was a surface-bound isotropically emitting point source and the second was a bath of free radioactivity in which the cell was submerged. Together these represent a targeted intraperitoneal radionuclide therapy. Monoenergetic single event spectra were calculated over an energy range of 11 keV to 2500 keV using the EGSnrc Monte Carlo system. Radionuclide single event spectra were constructed by weighting monoenergetic single event spectra according to radionuclide spectra appropriate for each source geometry. In the case of surface-bound radioactivity, these were radionuclide beta decay spectra. For the free radioactivity, a continuous slowing down approximation spectrum was used that was calculated based on the radionuclide decay spectra. The frequency mean specific energy per event increased as the energy of the beta emitter decreased. This is because, at these energies, the stopping power of the electrons decreases with increasing energy. The free radioactivity produced a higher frequency mean specific energy per event than the corresponding surface-bound value. This was primarily due to the longer mean path length through the target for this geometry. This information differentiates the radionuclides in terms of the physical process of energy deposition and could be of use in the radionuclide selection procedure for this type of therapy

  20. Reprogramming of various cell types to a beta-like state by Pdx1, Ngn3 and MafA.

    Science.gov (United States)

    Akinci, Ersin; Banga, Anannya; Tungatt, Katie; Segal, Joanna; Eberhard, Daniel; Dutton, James R; Slack, Jonathan M W

    2013-01-01

    The three transcription factors, PDX1, NGN3 and MAFA, are very important in pancreatic development. Overexpression of these three factors can reprogram both pancreatic exocrine cells and SOX9-positive cells of the liver into cells resembling pancreatic beta cells. In this study we investigate whether other cell types can be reprogrammed. Eight cell types are compared and the results are consistent with the idea that reprogramming occurs to a greater degree for developmentally related cells (pancreas, liver) than for other types, such as fibroblasts. Using a line of mouse hepatocyte-derived cells we screened 13 compounds for the ability to increase the yield of reprogrammed cells. Three are active and when used in combination they can increase the yield of insulin-immunopositive cells by a factor of six. These results should contribute to the eventual ability to develop a new cure for diabetes based on the ability to reprogram other cells in the body to a beta cell phenotype.

  1. Functional characterization of the beta-adrenergic receptor subtypes expressed by CA1 pyramidal cells in the rat hippocampus.

    Science.gov (United States)

    Hillman, Kristin L; Doze, Van A; Porter, James E

    2005-08-01

    Recent studies have demonstrated that activation of the beta-adrenergic receptor (AR) using the selective beta-AR agonist isoproterenol (ISO) facilitates pyramidal cell long-term potentiation in the cornu ammonis 1 (CA1) region of the rat hippocampus. We have previously analyzed beta-AR genomic expression patterns of 17 CA1 pyramidal cells using single cell reverse transcription-polymerase chain reaction, demonstrating that all samples expressed the beta2-AR transcript, with four of the 17 cells additionally expressing mRNA for the beta1-AR subtype. However, it has not been determined which beta-AR subtypes are functionally expressed in CA1 for these same pyramidal neurons. Using cell-attached recordings, we tested the ability of ISO to increase pyramidal cell action potential (AP) frequency in the presence of subtype-selective beta-AR antagonists. ICI-118,551 [(+/-)-1-[2,3-(dihydro-7-methyl-1H-inden-4-yl)oxy]-3-[(1-methylethyl)amino]-2-butanol] and butoxamine [alpha-[1-(t-butylamino)ethyl]-2,5-dimethoxybenzyl alcohol) hydrochloride], agents that selectively block the beta2-AR, produced significant parallel rightward shifts in the concentration-response curves for ISO. From these curves, apparent equilibrium dissociation constant (K(b)) values of 0.3 nM for ICI-118,551 and 355 nM for butoxamine were calculated using Schild regression analysis. Conversely, effective concentrations of the selective beta1-AR antagonists CGP 20712A [(+/-)-2-hydroxy-5-[2-([2-hydroxy-3-(4-[1-methyl-4-(trifluoromethyl)-1H-imidazol-2-yl]phenoxy)propyl]amino)ethoxy]-benzamide methanesulfonate] and atenolol [4-[2'-hydroxy-3'-(isopropyl-amino)propoxy]phenylacetamide] did not significantly affect the pyramidal cell response to ISO. However, at higher concentrations, atenolol significantly decreased the potency for ISO-mediated AP frequencies. From these curves, an apparent atenolol K(b) value of 3162 nM was calculated. This pharmacological profile for subtype-selective beta-AR antagonists

  2. Taurine prevents beta-glycerophosphate-induced calcification in cultured rat vascular smooth muscle cells.

    Science.gov (United States)

    Li, Juxiang; Zhang, Baohong; Huang, Zhiyu; Wang, Shuhen; Tang, Chaoshu; Du, Junbao

    2004-05-01

    Vascular calcification is an ectopic calcification that commonly occurs in atherosclerosis. Because taurine was previously shown to protect against cardiovascular diseases, the effect of taurine on vascular calcification was evaluated in calcified vascular smooth muscle cells (VSMCs) of rat in vitro in the present study. Osteoblastic differentiation, calcification, and proliferation in VSMCs were detected in the presence and absence of taurine. Alkaline phosphatase (ALP), cellular calcium content, and (45)Ca accumulation were measured as the indicators of osteoblastic differentiation and calcification. Incubation of VSMCs with Beta-glycerophosphate for 10 days induced an osteoblast-like morphological change. The activity of ALP was enhanced. Calcium content and (45)Ca uptake were increased in these cells. Calcification of these VSMCs was demonstrated with Beta-glycerophosphate treatment. In association with these alterations, cell proliferation, detected by cell counting, [(3)H]thymidine ([(3)H]TdR), and [(3)H]leucine ([(3)H]Leu) incorporation, was also increased in these calcified VSMCs. Taurine at 20 mmol/l decreased calcium content, (45)Ca(2+) uptake, and ALP activity both after early and late treatment, in which a reduction of the cell count, [(3)H"]TdR, and [(3)H]Leu incorporation of calcified VSMCs was also noted. Compared with the calcified group, morphological changes in the VSMCs of the early-treated group were deferred. These results demonstrated that calcification of VSMCs could be alleviated by taurine. Taurine treatment appeared to be more beneficial when the treatment was started earlier.

  3. Dystroglycan loss disrupts polarity and beta-casein induction inmammary epithelial cells by perturbing laminin anchoring

    Energy Technology Data Exchange (ETDEWEB)

    Weir, M. Lynn; Oppizzi, Maria Luisa; Henry, Michael D.; Onishi,Akiko; Campbell, Kevin P.; Bissell, Mina J.; Muschler, John L.

    2006-02-17

    Precise contact between epithelial cells and their underlying basement membrane is critical to the maintenance of tissue architecture and function. To understand the role that the laminin receptor dystroglycan (DG) plays in these processes, we assayed cell responses to laminin-111 following conditional ablation of DG expression in cultured mammary epithelial cells (MECs). Strikingly, DG loss disrupted laminin-111-induced polarity and {beta}-casein production, and abolished laminin assembly at the step of laminin binding to the cell surface. DG re-expression restored these deficiencies. Investigations of mechanism revealed that DG cytoplasmic sequences were not necessary for laminin assembly and signaling, and only when the entire mucin domain of extracellular DG was deleted did laminin assembly not occur. These results demonstrate that DG is essential as a laminin-111 co-receptor in MECs that functions by mediating laminin anchoring to the cell surface, a process that allows laminin polymerization, tissue polarity, and {beta}-casein induction. The observed loss of laminin-111 assembly and signaling in DG-/-MECs provides insights into the signaling changes occurring in breast carcinomas and other cancers, where DG's laminin-binding function is frequently defective.

  4. Molecular mass distribution and epitopes of the beta lactoglobulin submitted to hydrolysis pre-transglutaminase treatment

    International Nuclear Information System (INIS)

    Villas-Boas, M.B.; Zollner, R.L.; Netto, F.M.; Paes Leme, A.F.; Benede, S.; Molina, E.

    2012-01-01

    Full text: The β-Lactoglobulin (β-Lg) is a whey protein with important nutritional proper ties but very resistant to pepsin digestion and consequently highly antigenic. This protein can be modified by transglutaminase (TG) although it is required a pretreatment to increase their susceptibility to the TG action. In the present study the hydrolysis pre-TG treatment was used to improve the TG accessibility on β-Lg and the MM distribution and antigenic fragments were evaluated. For pre-TG treatment, the β-Lg (Davisco Inc.) was hydrolyzed with bromelain (3% of β-Lg w/w in distilled water; 25 U enzyme g 1 of substrate, pH 7.5, 240 min) and then polymerized by TG (7% hydrolysate, 10U TG g 1 protein, 50 C/180 min). The samples were evaluated by SDS-PAGE/tricine and by RP-nanoUPLC (nanoAcquity UPLC, Waters) coupled with nano-electrospray tandem mass spectrometry on a Q-Tof Ultima API mass spectrometer (MicroMass/Waters) at LNBio. The products were also submitted to pepsin digestion and the peptide identification was performed by RP-HPLC-tandem mass spectrometry (RP-HPLC-MS/MS, Brucker) with support from CIAL. The β-Lg hydrolysed by bromelain and polymerized by TG had a broad MM distribution. The intact mass analysis indicated that the non modified βLg -A showed 18.362 Da and the non modified βLg -B 18.274 Da, which is in agreement with the theoretical corresponding masses. The use of bromelain pre-TG treatment resulted in polymers with MM from 61.052 to 67.654 Da, although some non modified protein was still present. In addition, the non modified β-Lg showed fragments that present high antigenicity (such as Leu 95 - Leu 104 , Asp 95 - Phe 105 , Tyr 42 - Leu 54 , lle 29 - Val 41 ), previously identified as IgE-binding epitopes. After hydrolysis following by TG treatment the fragment Tyr 42 - Leu 54 was still present, however the other fragments that were observed in the non modified β-Lg were not detected by LC-MS/MS, suggesting that structural change occurred in

  5. Beta2-adaptin binds actopaxin and regulates cell spreading, migration and matrix degradation.

    Directory of Open Access Journals (Sweden)

    Jeanine Pignatelli

    Full Text Available Cell adhesion to the extracellular matrix is a key event in cell migration and invasion and endocytic trafficking of adhesion receptors and signaling proteins plays a major role in regulating these processes. Beta2-adaptin is a subunit of the AP-2 complex and is involved in clathrin-mediated endocytosis. Herein, β2-adaptin is shown to bind to the focal adhesion protein actopaxin and localize to focal adhesions during cells spreading in an actopaxin dependent manner. Furthermore, β2-adaptin is enriched in adhesions at the leading edge of migrating cells and depletion of β2-adaptin by RNAi increases cell spreading and inhibits directional cell migration via a loss of cellular polarity. Knockdown of β2-adaptin in both U2OS osteosarcoma cells and MCF10A normal breast epithelial cells promotes the formation of matrix degrading invadopodia, adhesion structures linked to invasive migration in cancer cells. These data therefore suggest that actopaxin-dependent recruitment of the AP-2 complex, via an interaction with β2-adaptin, to focal adhesions mediates cell polarity and migration and that β2-adaptin may control the balance between the formation of normal cell adhesions and invasive adhesion structures.

  6. Transforming growth factor-beta, but not ciliary neurotrophic factor, inhibits DNA synthesis of adrenal medullary cells in vitro

    DEFF Research Database (Denmark)

    Wolf, N; Krohn, K; Bieger, S

    1999-01-01

    by the neuroendocrine chromaffin cells, which also express the transforming growth factor-beta receptor type II. In contrast to the developmentally related sympathetic neurons, chromaffin cells continue to proliferate throughout postnatal life. Using 5-bromo-2'-deoxyuridine pulse labeling and tyrosine hydroxylase......Transforming growth factor-betas are members of a superfamily of multifunctional cytokines regulating cell growth and differentiation. Their functions in neural and endocrine cells are not well understood. We show here that transforming growth factor-betas are synthesized, stored and released...... immunocytochemistry as a marker for young postnatal rat chromaffin cells, we show that treatment with fibroblast growth factor-2 (1 nM) and insulin-like growth factor-II (10 nM) increased the fraction of 5-bromo-2'-deoxyuridine-labeled nuclei from 1% to about 40% of the cells in the absence of serum. In the presence...

  7. Glycopeptide profiling of beta-2-glycoprotein I by mass spectrometry reveals attenuated sialylation in patients with antiphospholipid syndrome

    DEFF Research Database (Denmark)

    Kondo, Akira; Miyamoto, Toshiaki; Yonekawa, Osamu

    2009-01-01

    beta2-glycoprotein I (beta2GPI) is a five-domain protein associated with the antiphospholipid syndrome (APS), however, its normal biological function is yet to be defined. beta2GPI is N-glycosylated at several asparagine residues and the glycan moiety conjugated to residue 143 has been proposed...... and the pathology of antiphospholipid syndrome....

  8. Sodium fluorocitrate having protective effect on palmitate-induced beta cell death improves hyperglycemia in diabetic db/db mice.

    Science.gov (United States)

    Jung, Ik-Rak; Choi, Sung-E; Hong, Seung A; Hwang, Yoonjung; Kang, Yup

    2017-10-10

    Beta cell loss and insulin resistance play roles in the pathogenesis of type 2 diabetes. Elevated levels of free fatty acids in plasma might contribute to the loss of beta cells. The objective of this study was to find a chemical that could protect against palmitate-induced beta cell death and investigate whether such chemical could improve hyperglycemia in mouse model of type 2 diabetes. Sodium fluorocitrate (SFC), an aconitase inhibitor, was found to be strongly and specifically protective against palmitate-induced INS-1 beta cell death. However, the protective effect of SFC on palmitate-induced cell death was not likely to be due to its inhibitory activity for aconitase since inhibition or knockdown of aconitase failed to protect against palmitate-induced cell death. Since SFC inhibited the uptake of palmitate into INS-1 cells, reduced metabolism of fatty acids was thought to be involved in SFC's protective effect. Ten weeks of treatment with SFC in db/db diabetic mice reduced glucose level but remarkably increased insulin level in the plasma. SFC improved impairment of glucose-stimulated insulin release and also reduced the loss of beta cells in db/db mice. Conclusively, SFC possessed protective effect against palmitate-induced lipotoxicity and improved hyperglycemia in mouse model of type 2 diabetes.

  9. Impact of incretin hormones on beta-cell function in subjects with normal or impaired glucose tolerance

    DEFF Research Database (Denmark)

    Muscelli, Elza; Mari, Andrea; Natali, Andrea

    2006-01-01

    The mechanisms by which the enteroinsular axis influences beta-cell function have not been investigated in detail. We performed oral and isoglycemic intravenous (IV) glucose administration in subjects with normal (NGT; n = 11) or impaired glucose tolerance (IGT; n = 10), using C-peptide deconvolu......The mechanisms by which the enteroinsular axis influences beta-cell function have not been investigated in detail. We performed oral and isoglycemic intravenous (IV) glucose administration in subjects with normal (NGT; n = 11) or impaired glucose tolerance (IGT; n = 10), using C......-peptide deconvolution to calculate insulin secretion rates and mathematical modeling to quantitate beta-cell function. The incretin effect was taken to be the ratio of oral to IV responses. In NGT, incretin-mediated insulin release [oral glucose tolerance test (OGTT)/IV ratio = 1.59 +/- 0.18, P = 0.004] amounted to 18......, with a predominance of glucose-induced vs. incretin-mediated stimulation. We conclude that, under physiological circumstances, incretin-mediated stimulation of insulin secretion results from an enhancement of all dynamic aspects of beta-cell function, particularly beta-cell glucose sensitivity. In IGT, beta...

  10. Growth suppression by transforming growth factor beta 1 of human small-cell lung cancer cell lines is associated with expression of the type II receptor

    DEFF Research Database (Denmark)

    Nørgaard, P; Damstrup, L; Rygaard, K

    1994-01-01

    the growth-suppressive effect of TGF-beta 1, the expression of functional pRb, as characterised by nuclear localisation, was examined by immunocytochemistry. Nuclear association of pRb was only seen in two of the five TGF-beta 1-responsive cell lines. These results indicate that in SCLC pRb is not required...

  11. Induction of cell scattering by expression of beta1 integrins in beta1-deficient epithelial cells requires activation of members of the rho family of GTPases and downregulation of cadherin and catenin function

    DEFF Research Database (Denmark)

    Gimond, C; van Der Flier, A; van Delft, S

    1999-01-01

    Adhesion receptors, which connect cells to each other and to the surrounding extracellular matrix (ECM), play a crucial role in the control of tissue structure and of morphogenesis. In this work, we have studied how intercellular adhesion molecules and beta1 integrins influence each other using two......-catenin protein levels accompanied by their redistribution from the cytoskeleton-associated fraction to the detergent-soluble fraction. Regulation of alpha-catenin protein levels by beta1 integrins is likely to play a role in the morphological transition, since overexpression of alpha-catenin in GE11 cells before...... beta1 prevented the disruption of intercellular adhesions and cell scattering. In addition, using biochemical activity assays for Rho-like GTPases, we show that the expression of beta1A, beta1D, or IL2R-beta1A in GE11 or GD25 cells triggers activation of both RhoA and Rac1, but not of Cdc42. Moreover...

  12. Expression of the alpha 6 beta 4 integrin by squamous cell carcinomas and basal cell carcinomas: possible relation to invasive potential?

    DEFF Research Database (Denmark)

    Rossen, K; Dahlstrøm, K K; Mercurio, A M

    1994-01-01

    We have studied the expression of alpha 6 beta 4 integrin, a carcinoma laminin receptor in ten squamous cell carcinomas (SCCs) and ten basal cell carcinomas (BCCs) of the skin in order to examine whether changes in alpha 6 beta 4 integrin expression may be related to invasive and metastatic...... potential. Monoclonal antibodies specific for each subunit were applied on cryosections, using a three step indirect peroxidase technique. In normal epidermis the basal cells expressed both the alpha 6 and the beta 4 subunits, and the expression was polarized against the basement membrane. In SCCs...

  13. Analysis of bone marrow stromal cell transferred bacterial {beta}-galactosidase gene by PIXE

    Energy Technology Data Exchange (ETDEWEB)

    Kumakawa, Toshiro [Tokyo Metropolitan Geriatric Hospital, Tokyo (Japan). Dept. of Blood Transfusion and Hematology; Hibino, Hitoshi; Tani, Kenzaburo; Asano, Shigetaka; Futatugawa, Shouji; Sera, Kouichiro

    1997-12-31

    PIXE, Particle Induced X-ray Emission, is a powerful, multi-elemental analysis method which has many distinguishing features and has been used in varies research fields. Recently the method of applying baby cyclotrons for nuclear medicine to PIXE has been developed. This enables us to study biomedical phenomena from the physical point of view. Mouse bone marrow stromal cells were transferred bacterial {beta}-galactosidase gene (LacZ gene) by murine retroviral vectors. Analysis of the bone marrow stromal cells with the LacZ gene by PIXE revealed remarkable changes of intracellular trace elements compared with the normal control cells. These results indicate that gene transfer by retroviral vectors may bring about a dynamic change of intracellular circumstances of the target cell. (author)

  14. Strain-dependent differences in sensitivity of rat beta-cells to interleukin 1 beta in vitro and in vivo

    DEFF Research Database (Denmark)

    Reimers, J I; Andersen, H U; Mauricio, D

    1996-01-01

    and nitrite production in vitro and islet iNOS protein content in vivo. Isolated islets of Langerhans in vitro from Wistar-Kyoto/Møllegården (WK/Mol) rats were sensitive to the inhibitory effect of IL-1 beta on accumulated and acute insulin secretion, whereas islets from Brown Norway/Charles River (BN...

  15. Nervous glucose sensing regulates postnatal beta cell proliferation and glucose homeostasis

    OpenAIRE

    Tarussio, David; Metref, Salima; Seyer, Pascal; Mounien, Lourdes; Vallois, David; Magnan, Christophe; Foretz, Marc; Thorens, Bernard

    2014-01-01

    How glucose sensing by the nervous system impacts the regulation of â cell mass and function during postnatal development and throughout adulthood is incompletely understood. Here we studied mice with inactivation of glucose transporter 2 (Glut2) in the nervous system (NG2KO mice). These mice displayed normal energy homeostasis but developed late onset glucose intolerance due to reduced insulin secretion which was precipitated by high fat diet feeding. The â cell mass of adult NG2KO mice was ...

  16. The fibronectin-binding integrins alpha5beta1 and alphavbeta3 differentially modulate RhoA-GTP loading, organization of cell matrix adhesions, and fibronectin fibrillogenesis

    DEFF Research Database (Denmark)

    Danen, Erik H J; Sonneveld, Petra; Brakebusch, Cord

    2002-01-01

    We have studied the formation of different types of cell matrix adhesions in cells that bind to fibronectin via either alpha5beta1 or alphavbeta3. In both cases, cell adhesion to fibronectin leads to a rapid decrease in RhoA activity. However, alpha5beta1 but not alphavbeta3 supports high levels...... subunits, we find that the extracellular domain of beta1 controls RhoA activity. By expressing both beta1 and beta3 at high levels, we show that beta1-mediated control of the levels of beta3 is important for the distribution of focal contacts. Our findings demonstrate that the pattern of fibronectin...... receptors expressed on a cell dictates the ability of fibronectin to stimulate RhoA-mediated organization of cell matrix adhesions....

  17. Assessment of TCR-beta clonality in a diverse group of cutaneous T-Cell infiltrates.

    Science.gov (United States)

    Plaza, Jose Antonio; Morrison, Carl; Magro, Cynthia M

    2008-04-01

    While some unequivocally benign infiltrates are easy to distinguish from cutaneous T-cell lymphoma (CTCL), drug-associated lymphomatoid hypersensitivity reaction and cutaneous lesions of collagen vascular disease can show cytologic atypia, clonality and an immunophenotypic profile that closely simulates CTCL and cause diagnostics difficulties. Similar immunophenotypic and molecular abnormalities to those of malignant lymphoma can also be observed in pityriasis lichenoides chronica (PLC), large plaque parapsoriasis (LPP), pigmented purpuric dermatosis (PPD) and atypical lymphocytic lobular panniculitis leading one to consider these entities as forms of cutaneous lymphoid dyscrasia. The purpose of our study was to evaluate the distinction of these various subcategories of cutaneous T-cell infiltrates by assessment of T-cell receptor (TCR)-beta gene rearrangement. Formalin-fixed paraffin-embedded skin biopsies from 80 patients containing a T-cell dominant lymphocytic infiltrate were analyzed for TCR-beta gene rearrangement. Our findings indicate that monoclonality is a reliable characteristic of CTCL with polyclonality being very infrequent. However, some cases of drug associated lymphomatoid hypersensitivity, collagen vascular disease and the various cutaneous lymphoid dyscrasias (i.e. PLC, PPD and atypical lymphocytic lobular panniculitis) could manifest restricted molecular profiles in the context of an oligoclonal process or frank monoclonality.

  18. The cysteine-rich domain of human ADAM 12 supports cell adhesion through syndecans and triggers signaling events that lead to beta1 integrin-dependent cell spreading

    DEFF Research Database (Denmark)

    Iba, K; Albrechtsen, R; Gilpin, B

    2000-01-01

    The ADAMs (a disintegrin and metalloprotease) family of proteins is involved in a variety of cellular interactions, including cell adhesion and ecto- domain shedding. Here we show that ADAM 12 binds to cell surface syndecans. Three forms of recombinant ADAM 12 were used in these experiments......-dependent manner attach to ADAM 12 via members of the syndecan family. After binding to syndecans, mesenchymal cells spread and form focal adhesions and actin stress fibers. Integrin beta1 was responsible for cell spreading because function-blocking monoclonal antibodies completely inhibited cell spreading......, and chondroblasts lacking beta1 integrin attached but did not spread. These data suggest that mesenchymal cells use syndecans as the initial receptor for the ADAM 12 cysteine-rich domain-mediated cell adhesion, and then the beta1 integrin to induce cell spreading. Interestingly, carcinoma cells attached but did...

  19. 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

  20. Use of RGD-Functionalized Sandwich Cultures to Promote Redifferentiation of Human Pancreatic Beta Cells After In Vitro Expansion.

    Science.gov (United States)

    Aloy-Reverté, Caterina; Moreno-Amador, José L; Nacher, Montserrat; Montanya, Eduard; Semino, Carlos E

    2018-03-01

    Islet transplantation has provided proof of concept that cell therapy can restore normoglycemia in patients with diabetes. However, limited availability of islet tissue severely restricts the clinical use of the treatment. Thus, there is an urgent need to develop new strategies to generate an abundant source of insulin-producing cells that could be used to treat diabetes. A potential approach is the in vitro expansion of pancreatic beta cells obtained from cadaveric organ donors. However, when human beta cells are expanded in vitro, they dedifferentiate and lose the expression of insulin, probably as a consequence of pancreatic islet dissociation into single cells. We have studied whether reestablishment of cell-cell and cell-matrix relationships with a biomimetic synthetic scaffold could induce redifferentiation of expanded dedifferentiated beta cells. Cells isolated from human islet preparations were expanded in monolayer cultures and allowed to reaggregate into islet-like cell clusters (ICCs). Afterward, ICCs were embedded between two thin layers of the noninstructive self-assembling peptide (SAP), RAD16-I or RAD16-I functionalized with the integrin-binding motif RGD (RAD16-I/RGD) (R: arginine, G: glycine, D: aspartic acid), which was expected to promote cell-extracellular matrix interactions. ICCs cultured with RAD16-I were viable, maintained their cluster conformation, and increased in size by aggregation of ICCs, suggesting a self-organizing process. ICCs cultured in RAD16-I/RGD showed enhanced cell adhesion to RAD16-I matrix and reexpression of the beta cell-specific genes, Ins, Pdx1, Nkx6.1, and MafA. Redifferentiation was caused solely by bioactive cues introduced to the RAD16-I peptide since no differentiation factors were added to the culture medium. The results indicate that RGD-functionalized SAP in sandwich conformation is a promising three-dimensional platform to induce redifferentiation toward a beta cell phenotype and to generate insulin

  1. The zinc transporter ZNT3 co-localizes with insulin in INS-1E pancreatic beta cells and influences cell survival, insulin secretion capacity, and ZNT8 expression

    DEFF Research Database (Denmark)

    Smidt, Kamille; Larsen, Agnete; Brønden, Andreas

    2016-01-01

    Zinc trafficking in pancreatic beta cells is tightly regulated by zinc transporting (ZNTs) proteins. The role of different ZNTs in the beta cells is currently being clarified. ZNT8 transports zinc into insulin granules and is critical for a correct insulin crystallization and storage...... in the granules whereas ZNT3 knockout negatively affects beta cell function and survival. Here, we describe for the first time the sub-cellular localization of ZNT3 by immuno-gold electron microscopy and supplement previous data from knockout experiments with investigations of the effect of ZNT3 in a pancreatic...... beta cell line, INS-1E overexpressing ZNT3. In INS-1E cells, we found that ZNT3 was abundant in insulin containing granules located close to the plasma membrane. The level of ZNT8 mRNA was significantly decreased upon over-expression of ZNT3 at different glucose concentrations (5, 11 and 21 mM glucose...

  2. Expression of transient receptor potential ankyrin 1 (TRPA1 and its role in insulin release from rat pancreatic beta cells.

    Directory of Open Access Journals (Sweden)

    De-Shou Cao

    Full Text Available Several transient receptor potential (TRP channels are expressed in pancreatic beta cells and have been proposed to be involved in insulin secretion. However, the endogenous ligands for these channels are far from clear. Here, we demonstrate the expression of the transient receptor potential ankyrin 1 (TRPA1 ion channel in the pancreatic beta cells and its role in insulin release. TRPA1 is an attractive candidate for inducing insulin release because it is calcium permeable and is activated by molecules that are produced during oxidative glycolysis.Immunohistochemistry, RT-PCR, and Western blot techniques were used to determine the expression of TRPA1 channel. Ca²⁺ fluorescence imaging and electrophysiology (voltage- and current-clamp techniques were used to study the channel properties. TRPA1-mediated insulin release was determined using ELISA.TRPA1 is abundantly expressed in a rat pancreatic beta cell line and freshly isolated rat pancreatic beta cells, but not in pancreatic alpha cells. Activation of TRPA1 by allyl isothiocyanate (AITC, hydrogen peroxide (H₂O₂, 4-hydroxynonenal (4-HNE, and cyclopentenone prostaglandins (PGJ₂ and a novel agonist methylglyoxal (MG induces membrane current, depolarization, and Ca²⁺ influx leading to generation of action potentials in a pancreatic beta cell line and primary cultured pancreatic beta cells. Activation of TRPA1 by agonists stimulates insulin release in pancreatic beta cells that can be inhibited by TRPA1 antagonists such as HC030031 or AP-18 and by RNA interference. TRPA1-mediated insulin release is also observed in conditions of voltage-gated Na⁺ and Ca²⁺ channel blockade as well as ATP sensitive potassium (K(ATP channel activation.We propose that endogenous and exogenous ligands of TRPA1 cause Ca²⁺ influx and induce basal insulin release and that TRPA1-mediated depolarization acts synergistically with K(ATP channel blockade to facilitate insulin release.

  3. SIRT1 inhibits proliferation of pancreatic cancer cells expressing pancreatic adenocarcinoma up-regulated factor (PAUF), a novel oncogene, by suppression of {beta}-catenin

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Il-Rae [WCU, Department of Cogno-Mechatronics Engineering, Pusan National University, Busan 609-735 (Korea, Republic of); Koh, Sang Seok [Immunotherapy Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-333 (Korea, Republic of); Department of Functional Genomics, University of Science and Technology, Daejeon 305-333 (Korea, Republic of); Malilas, Waraporn; Srisuttee, Ratakorn; Moon, Jeong [WCU, Department of Cogno-Mechatronics Engineering, Pusan National University, Busan 609-735 (Korea, Republic of); Choi, Young-Whan [Department of Horticultural Bioscience, Pusan National University, Miryang 627-706 (Korea, Republic of); Horio, Yoshiyuki [Department of Pharmacology, Sapporo Medical University, Sapporo 060-8556 (Japan); Oh, Sangtaek [Department of Advanced Fermentation Fusion Science and Technology, Kookmin University, Seoul 136-702 (Korea, Republic of); Chung, Young-Hwa, E-mail: younghc@pusan.ac.kr [WCU, Department of Cogno-Mechatronics Engineering, Pusan National University, Busan 609-735 (Korea, Republic of)

    2012-06-29

    Highlights: Black-Right-Pointing-Pointer SIRT1 inhibits protein levels of {beta}-catenin and its transcriptional activity. Black-Right-Pointing-Pointer Nuclear localization of SIRT1 is not required for the decrease of {beta}-catenin expression. Black-Right-Pointing-Pointer SIRT1-mediated degradation of {beta}-catenin is not required for GSK-3{beta} and Siah-1 but for proteosome. Black-Right-Pointing-Pointer SIRT1 activation inhibits proliferation of pancreatic cancer cells expressing PAUF. -- Abstract: Because we found in a recent study that pancreatic adenocarcinoma up-regulated factor (PAUF), a novel oncogene, induces a rapid proliferation of pancreatic cells by up-regulation of {beta}-catenin, we postulated that {beta}-catenin might be a target molecule for pancreatic cancer treatment. We thus speculated whether SIRT1, known to target {beta}-catenin in a colon cancer model, suppresses {beta}-catenin in those pancreatic cancer cells that express PAUF (Panc-PAUF). We further evaluated whether such suppression would lead to inhibition of the proliferation of these cells. The ectopic expression of either SIRT1 or resveratrol (an activator of SIRT1) suppressed levels of {beta}-catenin protein and its transcriptional activity in Panc-PAUF cells. Conversely, suppression of SIRT1 expression by siRNA enhanced {beta}-catenin expression and transcriptional activity. SIRT1 mutant analysis showed that nuclear localization of SIRT1 is not required for reduction of {beta}-catenin. Treatment with MG132, a proteasomal inhibitor, restored {beta}-catenin protein levels, suggesting that SIRT1-mediated degradation of {beta}-catenin requires proteasomal activity. It was reported that inhibition of GSK-3{beta} or Siah-1 stabilizes {beta}-catenin in colon cancer cells, but suppression of GSK-3{beta} or Siah-1 using siRNA in the presence of resveratrol instead diminished {beta}-catenin protein levels in Panc-PAUF cells. This suggests that GSK-3{beta} and Siah-1 are not involved in SIRT1

  4. Reduced thymic maturation but normal effector function of CD8+ T cells in CD8 beta gene-targeted mice

    OpenAIRE

    1994-01-01

    CD8 is a cell surface glycoprotein on major histocompatibility complex class I-restricted T cells. Thymocytes and most peripheral T cells express CD8 as heterodimers of CD8 alpha and CD8 beta. The intestinal intraepithelial lymphocytes (IEL), which have been suggested to be generated extrathymically, express CD8 predominantly as homodimers of CD8 alpha. We have generated CD8 beta gene-targeted mice. CD8 alpha+ T cell population in the thymus and in most peripheral lymphoid organs was reduced ...

  5. Biologic activities of recombinant human-beta-defensin-4 toward cultured human cancer cells.

    Science.gov (United States)

    Gerashchenko, O L; Zhuravel, E V; Skachkova, O V; Khranovska, N N; Filonenko, V V; Pogrebnoy, P V; Soldatkina, M A

    2013-06-01

    The aim of the study was in vitro analysis of biological activity of recombinant human beta-defensin-4 (rec-hBD-4). hBD-4 cDNA was cloned into pGEX-2T vector, and recombinant plasmid was transformed into E. coli BL21(DE3) cells. To purify soluble fusion GST-hBD-4 protein, affinity chromatography was applied. Rec-hBD-4 was cleaved from the fusion protein with thrombin, and purified by reverse phase chromatography on Sep-Pack C18. Effects of rec-hBD-4 on proliferation, viability, cell cycle distribution, substrate-independent growth, and mobility of cultured human cancer cells of A431, A549, and TPC-1 lines were analyzed by direct cell counting technique, MTT assay, flow cytofluorometry, colony forming assay in semi-soft medium, and wound healing assay. Rec-hBD-4 was expressed in bacterial cells as GST-hBD-4 fusion protein, and purified by routine 3-step procedure (affine chromatography on glutathione-agarose, cleavage of fusion protein by thrombin, and reverse phase chromatography). Analysis of in vitro activity of rec-hBD-4 toward three human cancer cell lines has demonstrated that the defensin is capable to affect cell behaviour in concentration-dependent manner. In 1-100 nM concentrations rec-hBD-4 significantly stimulates cancer cell proliferation and viability, and promotes cell cycle progression through G2/M checkpoint, greatly enhances colony-forming activity and mobility of the cells. Treatment of the cells with 500 nM of rec-hBD-4 resulted in opposite effects: significant suppression of cell proliferation and viability, blockage of cell cycle in G1/S checkpoint, significant inhibition of cell migration and colony forming activity. Recombinant human beta-defensin-4 is biologically active peptide capable to cause oppositely directed effects toward biologic features of cancer cells in vitro dependent on its concentration.

  6. Mass Spectral Profile for Rapid Differentiating Beta-Lactams from Their Ring-Opened Impurities

    Directory of Open Access Journals (Sweden)

    Hecheng Wang

    2015-01-01

    Full Text Available High performance liquid chromatography tandem mass spectrometry (HPLC MS has been widely used for β-lactam antibiotics determination. However, its application to identify impurities of these frequently used drugs is not sufficient at present. In this job, characteristic profiles of the collision induced dissociation (CID spectra of both β-lactams and ring-opened β-lactams were extracted from the MS data of six β-lactam antibiotics and their forty-five impurities, and were confirmed by the MS data reported in the literature. These characteristics have been successfully applied to rapid differentiation of β-lactam and ring-opened β-lactam impurities in cefixime, cefdinir, and cefaclor. However, these characteristic profiles can only be obtained under low activating voltage. They did not display in the high energy activated CID spectra. Diagnostic fragmentations for determining the localization of double bond and substituents on the thiazine ring and the side chain were also observed. In addition, several characteristic fragmentations are hopeful to be used to differentiate the configurations of C-2 on the thiazine ring of ring-opened impurities, which is generally disadvantageous of mass spectrometry. Taken together, forty-five impurities were identified from the capsules of cefixime, cefdinir, and cefaclor.

  7. Involvement of interleukin 1 and interleukin 1 antagonist in pancreatic beta-cell destruction in insulin-dependent diabetes mellitus

    DEFF Research Database (Denmark)

    Mandrup-Poulsen, T; Zumsteg, U; Reimers, J

    1993-01-01

    In this review we propose that the balance between the action of interleukin 1 (IL-1) and its natural antagonist IL-1ra on the level of the insulin-producing pancreatic beta-cell may play a decisive role in the pathogenesis of insulin-dependent diabetes mellitus (IDDM). We argue that IL-1...... potentiated by other cytokines (tumor necrosis factor alpha, interferon gamma) is an important effector molecule involved in both early and late events in the immune-mediated process that leads to beta-cell destruction and IDDM. We also point out that surprisingly high molar excesses of IL-1ra over IL-1...... are necessary to block the action of IL-1 on islet beta-cells compared to islet alpha-cells in vitro and in animals. We suggest that the selectivity of beta-cell destruction in IDDM may be conferred on several levels: (1) homing of beta-cell antigen specific T cells, (2) targeted delivery of cytokines...

  8. Novel cell-based assay for detection of thyroid receptor beta-interacting environmental contaminants

    Science.gov (United States)

    Stavreva, Diana A.; Varticovski, Lyuba; Levkova, Ludmila; George, Anuja A.; Davis, Luke; Pegoraro, Gianluca; Blazer, Vicki; Iwanowicz, Luke R.; Hager, Gordon L.

    2016-01-01

    Even though the presence of endocrine disrupting chemicals (EDCs) with thyroid hormone (TH)-like activities in the environment is a major health concern, the methods for their efficient detection and monitoring are still limited. Here we describe a novel cell assay, based on the translocation of a green fluorescent protein (GFP)—tagged chimeric molecule of glucocorticoid receptor (GR) and the thyroid receptor beta (TRβ) from the cytoplasm to the nucleus in the presence of TR ligands. Unlike the constitutively nuclear TRβ, this GFP-GR-TRβ chimera is cytoplasmic in the absence of hormone while translocating to the nucleus in a time- and concentration-dependent manner upon stimulation with triiodothyronine (T3) and thyroid hormone analogue, TRIAC, while the reverse triiodothyronine (3,3′,5′-triiodothyronine, or rT3) was inactive. Moreover, GFP-GR-TRβ chimera does not show any cross-reactivity with the GR-activating hormones, thus providing a clean system for the screening of TR beta-interacting EDCs. Using this assay, we demonstrated that Bisphenol A (BPA) and 3,3′,5,5′-Tetrabromobisphenol (TBBPA) induced GFP-GR-TRβ translocation at micro molar concentrations. We screened over 100 concentrated water samples from different geographic locations in the United States and detected a low, but reproducible contamination in 53% of the samples. This system provides a novel high-throughput approach for screening for endocrine disrupting chemicals (EDCs) interacting with TR beta.

  9. Structural and Functional Studies of Ig[alpha beta] and Its Assembly with the B Cell Antigen Receptor

    Energy Technology Data Exchange (ETDEWEB)

    Radaev, Sergei; Zou, Zhongcheng; Tolar, Pavel; Nguyen, Khanh; Nguyen, AnhThao; Krueger, Peter D.; Stutzman, Nicole; Pierce, Susan; Sun, Peter D. (NIH)

    2010-11-09

    The B cell antigen receptor (BCR) plays an essential role in all phases of B cell development. Here we show that the extracellular domains of murine and human Ig{beta} form an I-set immunoglobulin-like structure with an interchain disulfide between cysteines on their G strands. Structural and sequence analysis suggests that Ig{alpha} displays a similar fold as Ig{beta}. An Ig{alpha}{beta} heterodimer model was generated based on the unique disulfide-bonded Ig{beta} dimer. Solution binding studies showed that the extracellular domains of Ig{alpha}{beta} preferentially recognize the constant region of BCR with chain specificity, suggesting a role for Ig{alpha}{beta} to enhance BCR chain signaling. Cluster mutations on Ig{alpha}, Ig{beta}, and a membrane-bound form of immunoglobulin (mIgM) based on the structural model identified distinct areas of potential contacts involving charged residues on both subunits of the coreceptor and the C4 domain of mIgM. These studies provide the first structural model for understanding BCR function.

  10. BetaS-haplotypes in sickle cell anemia patients from Salvador, Bahia, Northeastern Brazil.

    Science.gov (United States)

    Gonçalves, M S; Bomfim, G C; Maciel, E; Cerqueira, I; Lyra, I; Zanette, A; Bomfim, G; Adorno, E V; Albuquerque, A L; Pontes, A; Dupuit, M F; Fernandes, G B; dos Reis, M G

    2003-10-01

    BetaS-Globin haplotypes were studied in 80 (160 betaS chromosomes) sickle cell disease patients from Salvador, Brazil, a city with a large population of African origin resulting from the slave trade from Western Africa, mainly from the Bay of Benin. Hematological and hemoglobin analyses were carried out by standard methods. The betaS-haplotypes were determined by PCR and dot-blot techniques. A total of 77 (48.1%) chromosomes were characterized as Central African Republic (CAR) haplotype, 73 (45.6%) as Benin (BEN), 1 (0.63%) as Senegal (SEN), and 9 (5.63%) as atypical (Atp). Genotype was CAR/CAR in 17 (21.3%) patients, BEN/BEN in 17 (21.3%), CAR/BEN in 37 (46.3%), BEN/SEN in 1 (1.25%), BEN/Atp in 1 (1.25%), CAR/Atp in 6 (7.5%), and Atp/Atp in 1 (1.25%). Hemoglobin concentrations and hematocrit values did not differ among genotype groups but were significantly higher in 25 patients presenting percent fetal hemoglobin (%HbF) > or = 10% (P = 0.002 and 0.003, respectively). The median HbF concentration was 7.54+/-4.342% for the CAR/CAR genotype, 9.88 3.558% for the BEN/BEN genotype, 8.146 4.631% for the CAR/BEN genotype, and 4.180+/-2.250% for the CAR/Atp genotype (P = 0.02), although 1 CAR/CAR individual presented an HbF concentration as high as 15%. In view of the ethnic and geographical origin of this population, we did not expect a Hardy-Weinberg equilibrium for CAR/CAR and BEN/BEN homozygous haplotypes and a high proportion of heterozygous CAR/BEN haplotypes since the State of Bahia historically received more slaves from Western Africa than from Central Africa.

  11. Energy depletion and not ROS formation is a crucial step of glucolipotoxicity (GLTx) in pancreatic beta cells.

    Science.gov (United States)

    Barroso Oquendo, Morgana; Layer, Nikolas; Wagner, Rebecca; Krippeit-Drews, Peter; Drews, Gisela

    2018-03-01

    We have shown previously that genetic or pharmacological deletion of K ATP channels protect against beta cell dysfunction induced by reactive oxygen species (ROS). Since it is assumed that glucolipotoxicity (GLTx) causes ROS production, we aimed to evaluate whether suppression of K ATP channel activity can also prevent beta cell damage evoked by GLTx. We used an in vitro model of GLTx and measured distinct parameters of stimulus-secretion coupling. GLTx gradually induced disturbances of Ca 2+ oscillations over 3 days. This impairment in Ca 2+ dynamics was partially reversed in beta cells without functional K ATP channels (SUR1 -/- ) and by the sulfonylurea gliclazide but not by tolbutamide. By contrast, the GLTx-induced suppression of glucose-induced insulin secretion could not be rescued by decreased K ATP channel activity pointing to a direct interaction of GLTx with the secretory capacity. Accordingly, GLTx also suppressed KCl-induced insulin secretion. GLTx was not accompanied by decisively increased ROS production or enhanced apoptosis. Insulin content of beta cells was markedly reduced by GLTx, an effect not prevented by gliclazide. Since GLTx markedly diminished the mitochondrial membrane potential and cellular ATP content, lack of ATP is assumed to decrease insulin biosynthesis. The deleterious effect of GLTx is therefore caused by direct interference with the secretory capacity whereby reduction of insulin content is one important parameter. These findings deepen our understanding how GLTx damages beta cells and reveal that GLTx is disconnected from ROS formation, a notion important for targeting beta cells in the treatment of diabetes. Overall, GLTx-induced energy depletion may be a primary step in the cascade of events leading to loss of beta cell function in type-2 diabetes mellitus.

  12. Flow cytometric analysis of expression of interleukin-2 receptor beta chain (p70-75) on various leukemic cells

    International Nuclear Information System (INIS)

    Hoshino, S.; Oshimi, K.; Tsudo, M.; Miyasaka, M.; Teramura, M.; Masuda, M.; Motoji, T.; Mizoguchi, H.

    1990-01-01

    We analyzed the expression of the interleukin-2 receptor (IL-2R) beta chain (p70-75) on various leukemic cells from 44 patients by flow cytometric analysis using the IL-2R beta chain-specific monoclonal antibody, designated Mik-beta 1. Flow cytometric analysis demonstrated the expression of the IL-2R beta chain on granular lymphocytes (GLs) from all eight patients with granular lymphocyte proliferative disorders (GLPDs), on adult T-cell leukemia (ATL) cells from all three patients with ATL, and on T-cell acute lymphoblastic leukemia (T-ALL) cells from one of three patients with T-ALL. Although GLs from all the GLPD patients expressed the IL-2R beta chain alone and not the IL-2R alpha chain (Tac-antigen: p55), ATL and T-ALL cells expressing the beta chain coexpressed the alpha chain. In two of seven patients with common ALL (cALL) and in both patients with B-cell chronic lymphocytic leukemia, the leukemic cells expressed the alpha chain alone. Neither the alpha chain nor the beta chain was expressed on leukemic cells from the remaining 28 patients, including all 18 patients with acute nonlymphocytic leukemia, five of seven patients with cALL, all three patients with multiple myeloma, and two of three patients with T-ALL. These results indicate that three different forms of IL-2R chain expression exist on leukemic cells: the alpha chain alone; the beta chain alone; and both the alpha and beta chains. To examine whether the results obtained by flow cytometric analysis actually reflect functional aspects of the expressed IL-2Rs, we studied the specific binding of 125I-labeled IL-2 (125I-IL-2) to leukemic cells in 18 of the 44 patients. In addition, we performed 125I-IL-2 crosslinking studies in seven patients. The results of IL-2R expression of both 125I-IL-2 binding assay and crosslinking studies were in agreement with those obtained by flow cytometric analysis

  13. The effects of a HTR2B stop codon and testosterone on energy metabolism and beta cell function among antisocial Finnish males.

    Science.gov (United States)

    Tikkanen, Roope; Saukkonen, Tero; Fex, Malin; Bennet, Hedvig; Rautiainen, Marja-Riitta; Paunio, Tiina; Koskinen, Mika; Panarsky, Rony; Bevilacqua, Laura; Sjöberg, Rickard L; Tiihonen, Jari; Virkkunen, Matti

    2016-10-01

    Herein, we examined insulin resistance (IR), insulin sensitivity (IS), beta cell activity, and glucose metabolism in subjects with antisocial personality disorder (ASPD), and whether the serotonin 2B (5-HT2B) receptor and testosterone have a role in energy metabolism. A cohort of subjects belonging to a founder population that included 98 ASPD males, aged 25-30, was divided into groups based on the presence of a heterozygous 5-HT2B receptor loss-of-function gene mutation (HTR2B Q20*; n = 9) or not (n = 89). Serum glucose and insulin levels were measured in a 5 h oral glucose tolerance test (75 g) and indices describing IR, IS, and beta cell activity were calculated. Body mass index (BMI) was also determined. Concentrations of the serotonin metabolite 5-hydroxyindoleacetic acid were measured in cerebrospinal fluid, and testosterone levels from serum. An IR-like state comprising high IR, low IS, and high beta cell activity indices was observed among ASPD subjects without the HTR2B Q20* allele. By contrast, being an ASPD HTR2B Q20* carrier appeared to be preventive of these pathophysiologies. The HTR2B Q20* allele and testosterone predicted lower BMI independently, but an interaction between HTR2B Q20* and testosterone lead to increased insulin sensitivity among HTR2B Q20* carriers with low testosterone levels. The HTR2B Q20* allele also predicted reduced beta cell activity and enhanced glucose metabolism. Reduced 5-HT2B receptor function at low or normal testosterone levels may be protective of obesity. Results were observed among Finnish males having an antisocial personality disorder, which limits the generality. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. High value of the radiobiological parameter Dq correlates to expression of the transforming growth factor beta type II receptor in a panel of small cell lung cancer cell lines

    DEFF Research Database (Denmark)

    Hougaard, S; Krarup, M; Nørgaard, P

    1998-01-01

    Our panel of SCLC cell lines have previously been examined for their radiobiological characteristics and sensitivity to treatment with TGF beta 1. In this study we examined the possible correlations between radiobiological parameters and the expression of the TGF beta type II receptor (TGF beta......-rII). We have, in other studies, shown that the presence of TGF beta-rII was mandatory for transmitting the growth inhibitory effect of TGF beta. The results showed a statistically significant difference in Dq, i.e. the shoulder width of the survival curve, between cell lines expressing TGF beta......-rII and cell lines which did not express the receptor (P = 0.01). Cell lines expressing TGF beta-rII had a high Dq-value. TGF beta-rII expression did not correlate with any other radiobiological parameters. We suggest that an intact growth inhibitory pathway mediated by the TGF beta-rII may have a significant...

  15. Cytokines and beta-cell biology: from concept to clinical translation

    DEFF Research Database (Denmark)

    Donath, M.Y.; Storling, J.; Berchtold, L.A.

    2007-01-01

    The tale of cytokines and the beta-cell is a long story, starting with in vitro discovery in 1984, evolving via descriptive and phenomenological studies to detailed mapping of the signalling pathways, gene- and protein expression patterns, molecular and biochemical effector mechanisms to in vivo ...... as other laboratories that serve to illuminate the road from concept to clinical translation....... studies in spontaneously diabetic and transgenic animal models. Only very recently have steps been taken to translate the accumulating compelling preclinical data into clinical trials. The aim of this chapter is to present an overview of early and recent key observations from our own groups as well...

  16. Synergistic Effect of Hyperglycemia and Suppression on Adult Mouse Islet Beta Cell Replication

    Directory of Open Access Journals (Sweden)

    Szu-Tah Chen

    2012-01-01

    Full Text Available The complementary role of hyperglycemia and suppression on islet beta cell regeneration was investigated in a syngeneic mouse model. gene silencing was performed by infecting islets of C57BL/6 with shRNA lentiviral particles. At 54 hours after viral infection, protein content in cultured targeting islets was 22% of that in freshly isolated islets. Six days after transplantation to diabetic mice, targeting islet graft had considerably more cells with Ki67-staining nuclei than nontargeting islets. The mice in the targeting-islet group had a significantly shorter duration of temporary hyperglycaemia than mice in the non-targeting-islet group. The long-term ex vivo beneficial effect of silencing on graft function was also indicated by the significantly higher cumulative cure rate for diabetes in mice receiving 200 targeting islets than that in mice receiving 200 non-targeting islets. Our data suggest that hyperglycemia and persistent suppression have a synergistic effect on islet beta cell replication in adult mice.

  17. 5-Androstene-3{beta},17{beta}-diol Promotes Recovery of Immature Hematopoietic Cells Following Myelosuppressive Radiation and Synergizes With Thrombopoietin

    Energy Technology Data Exchange (ETDEWEB)

    Aerts-Kaya, Fatima S.F.; Visser, Trudi P.; Arshad, Shazia [Department of Hematology, Erasmus University Medical Center, Rotterdam (Netherlands); Frincke, James; Stickney, Dwight R.; Reading, Chris L. [Harbor Therapeutics, Inc, San Diego, California (United States); Wagemaker, Gerard, E-mail: g.wagemaker@erasmusmc.nl [Department of Hematology, Erasmus University Medical Center, Rotterdam (Netherlands)

    2012-11-01

    Purpose: 5-Androstene-3{beta},17{beta}-diol (5-AED) stimulates recovery of hematopoiesis after exposure to radiation. To elucidate its cellular targets, the effects of 5-AED alone and in combination with (pegylated) granulocyte colony-stimulating factor and thrombopoietin (TPO) on immature hematopoietic progenitor cells were evaluated following total body irradiation. Methods and Materials: BALB/c mice were exposed to radiation delivered as a single or as a fractionated dose, and recovery of bone marrow progenitors and peripheral blood parameters was assessed. Results: BALB/c mice treated with 5-AED displayed accelerated multilineage blood cell recovery and elevated bone marrow (BM) cellularity and numbers of progenitor cells. The spleen colony-forming unit (CFU-S) assay, representing the life-saving short-term repopulating cells in BM of irradiated donor mice revealed that combined treatment with 5-AED plus TPO resulted in a 20.1-fold increase in CFU-S relative to that of placebo controls, and a 3.7 and 3.1-fold increase in comparison to 5-AED and TPO, whereas no effect was seen of Peg-G-CSF with or without 5-AED. Contrary to TPO, 5-AED also stimulated reconstitution of the more immature marrow repopulating (MRA) cells. Conclusions: 5-AED potently counteracts the hematopoietic effects of radiation-induced myelosuppression and promotes multilineage reconstitution by stimulating immature bone marrow cells in a pattern distinct from, but synergistic with TPO.

  18. Effects of 17beta-estradiol and xenoestrogens on mouse embryonic stem cells.

    Science.gov (United States)

    Jung, Eui-Man; Choi, Kyung-Chul; Yu, Frank H; Jeung, Eui-Bae

    2010-09-01

    Xenoestrogens such as 4-tert-octylphenol (OP) and 4-nonylphenol (NP) can adversely affect the reproductive and immune systems from their estrogenic effects in target cells. In this study, we investigated the effects of xenoestrogens on the expression of undifferentiation markers in mouse embryonic stem (ES) cells and of cardiomyocyte differentiation markers in mouse embryoid body (EB) cells induced to differentiate into cardiomyocytes from ES cells. The expressions of undifferentiation markers (Oct4, Sox2, Zfp206, and Rex-1) and cardiomyocyte differentiation markers (alpha-MHC, beta-MHC, ANF, and MLC-2V) were determined by semi- and quantitative real-time PCR. Treatment with E(2) or OP and NP induced an increase in Oct4 expression at the transcriptional level in a dose- and time-dependent manner. However, no difference was observed in the expression of Sox2, Zfp206 or Rex-1 genes in ES cells, suggesting that E(2) may be an Oct4 enhancer in ES cells. Induction of Oct4 expression by E(2) and xenoestrogens (OP and NP) did not change the methylation pattern of the Oct4-promoter and was not affected by treatment with a demethylating agent, 5-azacytidine. Taken together, these results suggest that E(2) and xenoestrogens may impact on the undifferentiation process of ES and EB cells, and retain ES cells in an undifferentiated state. Copyright 2010 Elsevier Ltd. All rights reserved.

  19. Low temperature electrochemical cells with sodium {beta}''-alumina solid electrolyte (BASE)

    Energy Technology Data Exchange (ETDEWEB)

    Girija, T.C.; Virkar, Anil V. [Department of Materials Science and Engineering, 122 S. Central Campus Drive, University of Utah, Salt Lake City, UT 84112 (United States)

    2008-05-15

    Cells of Daniell-type with copper-zinc electrochemical couples and sodium {beta}''-alumina solid electrolyte (BASE) were constructed. The cathode consisted of copper in contact with its ions (Cu/Cu{sup 2+}) while zinc in contact with its ions (Zn/Zn{sup 2+}) constituted the anode. Dimethyl sulfoxide (DMSO) containing 1 M NaBF{sub 4} was used as the liquid electrolyte. The configuration of the cell constructed can be written as follows: Zn(s)/ZnCl{sub 2}(DMSO)(0.1 M), NaBF{sub 4}(1 M)/BASE/NaBF{sub 4}(1 M), CuCl{sub 2}(DMSO)(0.1 M)/Cu(s) The cell was subjected to charge-discharge cycles at 100 C. The BASE discs were found to be stable even after the cell was subjected to several electrochemical charge-discharge cycles. Cells were also constructed using BASE discs with porous BASE surface layers introduced to lower the interfacial resistance. Cells with surface modified BASE exhibited a lower resistance in comparison to those using unmodified BASE. XRD and SEM analyses indicated that no detectable degradation of BASE discs occurred after cell testing. Preliminary cell tests were also conducted with NaCF{sub 3}SO{sub 3} in place of NaBF{sub 4}. (author)

  20. Estrogen Receptor Beta Displays Cell Cycle-Dependent Expression and Regulates the G1 Phase through a Non-Genomic Mechanism in Prostate Carcinoma Cells

    Directory of Open Access Journals (Sweden)

    Antoni Hurtado

    2008-01-01

    Full Text Available Background: It is well known that estrogens regulate cell cycle progression, but the specific contributions and mechanisms of action of the estrogen receptor beta (ERβ remain elusive.

  1. Analysis of beta-agonists and beta-blockers in urine using hollow fibre-protected liquid-phase microextraction with in situ derivatization followed by gas chromatography/mass spectrometry.

    Science.gov (United States)

    Liu, Wei; Zhang, Lan; Wei, Zhenyi; Chen, Shengping; Chen, Guonan

    2009-07-10

    A method using hollow fibre-protected liquid-phase microextraction (HF-LPME) with in situ derivatization followed by gas chromatography/mass spectrometry (GC/MS) was established for the analysis of beta-agonists and beta-blockers in urine. Because it can simultaneously extract and derivatize compounds of interest by methylbenzol and N-methyl-N-(trimethylsilyl) trifluoroacetamide (MSTFA) in HF-LPME, the approach overcomes the drawbacks of considerable time-consuming and tedious operation, meanwhile improves enrichment multiple. The optimized conditions were extraction for 20 min at 35 degrees C with 5.0 microL of mixed extraction solvent (methylbenzol/MSTFA=1:1, v/v) with stirring speed of 925 rpm in 5.0 mL sample under pH 12.0 and 14% (w/v) NaCl. The method provided very wide linear ranges (0.25-400 ng mL(-1)) and low detection limits in the range of 0.08-0.10 ng mL(-1) for clenbuterol, metoprolol and propranolol while enrichment factors reached up to 256. The analytes could be determined in spiked urine by the method with high extraction efficacy (93.79-109.04% recoveries) and precision (<9.70% RSD). It has a satisfactory result for metoprolol in practical human urine samples for a single-dose administration of 50 mg after 36 h. The proposed method only needs few microliters of organic solvent and derivatizing agent; the operation is simple, convenient and rapid for the trace analysis of beta-agonists and beta-blockers in biological fluids; it can be readily generalized for high sample throughput. So, it is hopeful that the study will facilitate the monitoring of beta-agonists and beta-blockers in the competition sports.

  2. The biological activities of (1,3)-(1,6)-{beta}-d-glucan and porous electrospun PLGA membranes containing {beta}-glucan in human dermal fibroblasts and adipose tissue-derived stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Woo, Yeon I; Park, Bong Joo; Kim, Hye-Lee; Lee, Mi Hee; Kim, Jungsung; Park, Jong-Chul [Department of Medical Engineering, Yonsei University College of Medicine, 134 Shinchon-dong, Seodaemun-gu, Seoul 120-752 (Korea, Republic of); Yang, Young-Il [Department of Pathology, School of Medicine, Paik Institute for Clinical Research, Inje University, 633-165 Gae-dong, Busan-jin-gu, Busan 614-735 (Korea, Republic of); Kim, Jung Koo [Department of Biomedical Engineering, College of Biomedical Science and Engineering, Inje University, Kimhae 621-749 (Korea, Republic of); Tsubaki, Kazufumi [R and D division, Asahi Denka Co. Ltd, 7-2-35 Higashi-ogu, Arakawa-ku, Tokyo 116-8554 (Japan); Han, Dong-Wook, E-mail: parkjc@yuhs.a [Department of Nanomedical Engineering, College of Nanoscience and Nanotechnology, Pusan National University, geumjeong-gu, Busan 609-735 (Korea, Republic of)

    2010-08-01

    In this study, we investigated the possible roles of (1,3)-(1,6)-{beta}-d-glucan ({beta}-glucan) and porous electrospun poly-lactide-co-glycolide (PLGA) membranes containing {beta}-glucan for skin wound healing, especially their effect on adult human dermal fibroblast (aHDF) and adipose tissue-derived stem cell (ADSC) activation, proliferation, migration, collagen gel contraction and biological safety tests of the prepared membrane. This study demonstrated that {beta}-glucan and porous PLGA membranes containing {beta}-glucan have enhanced the cellular responses, proliferation and migration, of aHDFs and ADSCs and the result of a collagen gel contraction assay also revealed that collagen gels contract strongly after 4 h post-gelation incubation with {beta}-glucan. Furthermore, we confirmed that porous PLGA membranes containing {beta}-glucan are biologically safe for wound healing study. These results indicate that the porous PLGA membranes containing {beta}-glucan interacted favorably with the membrane and the topical administration of {beta}-glucan was useful in promoting wound healing. Therefore, our study suggests that {beta}-glucan and porous PLGA membranes containing {beta}-glucan may be useful as a material for enhancing wound healing.

  3. Neutrino mass, the right-handed interaction and the double beta decay, 2

    International Nuclear Information System (INIS)

    Doi, Masaru; Kotani, Tsuneyuki; Nishiura, Hiroyuki; Okuda, Kazuko; Takasugi, Eiichi.

    1981-01-01

    Based on the formulae for the double β decay obtained in the previous paper, the general properties of 0 + → J + transitions are discussed and the analysis of the experimental data is presented. It is found that, for the two neutrino mode, the 0 + → 0 + transition in the two nucleon (2n)-mechanism dominates over the 0 + → 2 + transition as well as the contribution from the N*-mechanism. For the neutrinoless mode, only the 0 + → 0 + transition in the 2n-mechanism is allowed if there is no right-handed interaction. When the right-handed interaction gives a sizable contribution, the role of the 0 + → 2 + transition becomes as important as the 0 + → 0 + transition in this mode. It is concluded that the experimental data on the ratio of the 128 Te to 130 Te half-lives by Hennecke et al. suggest that neutrinos are Majorana particles, if we take the Vergados estimation of the nuclear matrix elements. Moreover, we find that the weighted average of neutrino masses is around 34 eV if there is no right-handed interaction. (author)

  4. Inhibition of amyloid-beta-induced cell death in human brain pericytes in vitro.

    NARCIS (Netherlands)

    Rensink, A.A.M.; Verbeek, M.M.; Otte-Holler, I.; Donkelaar, H.J. ten; Waal, R.M.W. de; Kremer, H.P.H.

    2002-01-01

    Amyloid-beta protein (A beta) deposition in the cerebral vascular walls is one of the key features of Alzheimer's disease and hereditary cerebral hemorrhage with amyloidosis-Dutch type (HCHWA-D). A beta(1-40) carrying the 'Dutch' mutation (HCHWA-D A beta(1-40)) induces pronounced degeneration of

  5. The time has come to test the beta cell preserving effects of exercise in patients with new onset type 1 diabetes

    DEFF Research Database (Denmark)

    Narendran, Parth; Solomon, Thomas; Kennedy, Amy

    2015-01-01

    Type 1 diabetes is characterised by immune-mediated destruction of insulin-producing beta cells. Significant beta cell function is usually present at the time of diagnosis with type 1 diabetes, and preservation of this function has important clinical benefits. The last 30 years have seen a number...... for physical exercise as a therapy for the preservation of beta cell function in patients with newly diagnosed type 1 diabetes. We highlight possible mechanisms by which exercise could preserve beta cell function and then present evidence from other models of diabetes that demonstrate that exercise preserves...... beta cell function. We conclude by proposing that there is now a need for studies to explore whether exercise can preserve beta cell in patients newly diagnosed with type 1 diabetes....

  6. The alpha3 laminin subunit, alpha6beta4 and alpha3beta1 integrin coordinately regulate wound healing in cultured epithelial cells and in the skin

    DEFF Research Database (Denmark)

    Goldfinger, L E; Hopkinson, S B; deHart, G W

    1999-01-01

    Previously, we demonstrated that proteolytic processing within the globular domain of the alpha3 subunit of laminin-5 (LN5) converts LN5 from a cell motility-inducing factor to a protein complex that can trigger the formation of hemidesmosomes, certain cell-matrix attachment sites found in epithe......-inhibiting antibodies, we provide evidence that LN5 and its two integrin receptors (alpha6beta4 and alpha3beta1) appear necessary for wound healing to occur in MCF-10A cell culture wounds. We propose a model for healing of wounded epithelial tissues based on these results....... in epithelial cells. We have prepared a monoclonal antibody (12C4) whose epitope is located toward the carboxy terminus of the globular domain of the alpha3 laminin subunit. This epitope is lost from the alpha3 subunit as a consequence of proteolytic processing. Antibody 12C4 stains throughout the matrix...... the wound site. A similar phenomenon is observed in human skin wounds, since we also detect expression of the unprocessed alpha3 laminin subunit at the leading tip of the sheet of epidermal cells that epithelializes skin wounds in vivo. In addition, using alpha3 laminin subunit and integrin function...

  7. Analysis of the effect of diabetes type 2 duration on beta cell secretory function and insulin resistance

    Directory of Open Access Journals (Sweden)

    Popović Ljiljana

    2006-01-01

    Full Text Available Diabetes type 2 is a chronic metabolic disorder. Pathogenesis of diabetes type 2 results from the impaired insulin secretion, impaired insulin action and increased endogenous glucose production. Diabetes evolves through several phases characterized by qualitative and quantitative changes of beta cell secretory function. The aim of our study was to analyze the impact of diabetes duration on beta cell secretory function and insulin resistance. The results indicated significant negative correlation of diabetes duration and fasting insulinemia, as well as beta cell secretory function assessed by HOMA β index. Our study also found significant negative correlation of diabetes duration and insulin resistance assessed by HOMA IR index. Significant positive correlation was established between beta cell secretory capacity (fasting insulinemia and HOMA β and insulin resistance assessed by HOMA IR index, independently of diabetes duration. These results indicate that: beta cell secretory capacity, assessed by HOMA β index, significantly decreases with diabetes duration. In parallel with decrease of fasting insulinemia, reduction of insulin resistance assessed by HOMA IR index was found as well.

  8. Unmethylated Insulin DNA Is Elevated After Total Pancreatectomy With Islet Autotransplantation: Assessment of a Novel Beta Cell Marker.

    Science.gov (United States)

    Bellin, M D; Clark, P; Usmani-Brown, S; Dunn, T B; Beilman, G J; Chinnakotla, S; Pruett, T L; Ptacek, P; Hering, B J; Wang, Z; Gilmore, T; Wilhelm, J J; Hodges, J S; Moran, A; Herold, K C

    2017-04-01

    Beta cell death may occur both after islet isolation and during infusion back into recipients undergoing total pancreatectomy with islet autotransplantation (TPIAT) for chronic pancreatitis. We measured the novel beta cell death marker unmethylated insulin (INS) DNA in TPIAT recipients before and immediately after islet infusion (n = 21) and again 90 days after TPIAT, concurrent with metabolic functional assessments (n = 25). As expected, INS DNA decreased after pancreatectomy (p = 0.0002). All TPIAT recipients had an elevated unmethylated INS DNA ratio in the first hours following islet infusion. In four samples (three patients), INS DNA was also assessed immediately after islet isolation and again before islet infusion to assess the impact of the isolation process: Unmethylated and methylated INS DNA fractions both increased over this interval, suggesting death of beta cells and exocrine tissue before islet infusion. Higher glucose excursion with mixed-meal tolerance testing was associated with persistently elevated INS DNA at day 90. In conclusion, we observed universal early elevations in the beta cell death marker INS DNA after TPIAT, with pronounced elevations in the islet supernatant before infusion, likely reflecting beta cell death induced by islet isolation. Persistent posttransplant elevation of INS DNA predicted greater hyperglycemia at 90 days. © Copyright 2016 The American Society of Transplantation and the American Society of Transplant Surgeons.

  9. Extracellular matrix and hormones transcriptionally regulate bovine. beta. -casein 5 prime sequences in stably transfected mouse mammary cells

    Energy Technology Data Exchange (ETDEWEB)

    Schmidhauser, C. Bissell, M.J. (Univ. of California, Berkeley (United States)); Myers, C.A.; Casperson, G.F. (Monsanto Corporate Research, St. Louis, MO (United States))

    1990-12-01

    Milk protein regulation involves synergistic action of lactogenic hormones and extracellular matrix (ECM). It is well established that substratum has a dramatic effect on morphology and function of mammary cells. The molecular mechanisms that regulate the ECM- and hormone-dependent gene expression, however, have not been resolved. To address this question, a subpopulation (designated CID 9) of the mouse mammary epithelial cell strain COMMA-2D has been developed in which more than 35% of the cells express {beta}-casein, form alveoli-like structures when plated onto a reconstituted basement membrane, and secrete {beta}-casein undirectionally into a lumen. These cells were stably transfected with a series of chloramphenicol acetyltransferase (CAT) fusion genes to study transcriptional regulation of the bovine {beta}-casein gene. The expression of CAT in these lines demonstrated a striking matrix and hormone dependency. This regulation occurered primarily at the transcriptional level and was dependent on the length of the 5{prime} flanking region of the {beta}-casein promotor. Both matrix and hormonal control of transcription occurred within at least the first 1790 base pairs upstream and/or 42 base pairs downstream of the transcriptional initiation site. The ECM effect was independent of glucocorticoid stimulation. However, prolactin was essential and hydrocortisone further increased CAT expression. Endogenous {beta}-casein expression in these lines was similar to that of the parent CID 9 cells. Our data indicate the existence of matrix-dependent elements that regulate transcription.

  10. Overexpression of thyroid hormone beta1 nuclear receptor is associated with an increased proliferation of human hepatoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Lin, K.; Lin, Y.; McPhie, P. [Chang-Gung College of Medicine and Technology, Graduate Institute of Clinical Medicine, Taoyuan (Taiwan, Province of China); Cheng, S. [National Cancer Inst., Bethesda, MD (United States)

    1994-12-31

    It is evaluated the expression of thyroid hormone nuclear receptors (TRs) and their possible roles in the carcinogenesis of human hepatocarcinoma. The expression of TR{beta}1 and TR{alpha} genes was evaluated at both the mRNA and protein levels. The expression of TR{beta}1 and TR{alpha}1 mRNAs is similar to those found in normal liver. However, the expression of TR isoform proteins depends on the cell-type. The expression of TRaplha1 protein is low in all cell lines examined. However, TR{Beta}1 protein is overexpressed in Mahlavu, SK-Hep-1, and HA22T, moderately expressed in J5, J7, and J328 and is very low HepG2, Hep3B, and PLC/PRF/5 cells. The proliferation of cells in which TR{beta}1 is overexpressed is stimulated by the thyroid hormone, 3,3`,5- triiodo-L-thyronine. These results suggest that TR{beta}1, not TR{alpha}1, is probably involved in the prolifaration of hepatoma cells.

  11. beta-TrCP inhibition reduces prostate cancer cell growth via upregulation of the aryl hydrocarbon receptor.

    Directory of Open Access Journals (Sweden)

    Udi Gluschnaider

    2010-02-01

    Full Text Available Prostate cancer is a common and heterogeneous disease, where androgen receptor (AR signaling plays a pivotal role in development and progression. The initial treatment for advanced prostate cancer is suppression of androgen signaling. Later on, essentially all patients develop an androgen independent stage which does not respond to anti hormonal treatment. Thus, alternative strategies targeting novel molecular mechanisms are required. beta-TrCP is an E3 ligase that targets various substrates essential for many aspects of tumorigenesis.Here we show that beta-TrCP depletion suppresses prostate cancer and identify a relevant growth control mechanism. shRNA targeted against beta-TrCP reduced prostate cancer cell growth and cooperated with androgen ablation in vitro and in vivo. We found that beta-TrCP inhibition leads to upregulation of the aryl hydrocarbon receptor (AhR mediating the therapeutic effect. This phenomenon could be ligand independent, as the AhR ligand 2,3,7,8-Tetrachlorodibenzo-p-Dioxin (TCDD did not alter prostate cancer cell growth. We detected high AhR expression and activation in basal cells and atrophic epithelial cells of human cancer bearing prostates. AhR expression and activation is also significantly higher in tumor cells compared to benign glandular epithelium.Together these observations suggest that AhR activation may be a cancer counteracting mechanism in the prostate. We maintain that combining beta-TrCP inhibition with androgen ablation could benefit advanced prostate cancer patients.

  12. Different contributions of insulin resistance and beta-cell dysfunction in overweight Israeli Arabs with IFG and IGT.

    Science.gov (United States)

    Abdul-Ghani, Muhammad A; Sabbah, Muhammad; Kher, Joseph; Minuchin, Oscar; Vardi, Pnina; Raz, Itamar

    2006-01-01

    Impaired glucose tolerance (IGT) and impaired fasting glucose (IFG) are both intermediate stages that exist between normal glucose tolerance and overt type 2 diabetes. Epidemiological studies demonstrated that the two categories define distinct populations. In this study, we examined the contributions of insulin resistance and beta-cell dysfunction to both states in overweight subjects of Arab origin. Twelve subjects with isolated IFG, 10 with isolated IGT, and 20 with IFG and IGT (combined glucose in tolerance-CGT) were compared with 30 subjects with normal glucose tolerance (NGT) subjects; all were of Arab origin and were overweight or obese. Different indices for insulin resistance and beta-cell function were calculated from oral glucose tolerance (OGTT) values. Subjects with isolated IFG and CGT were more obese and had significantly higher values of insulin resistance than subjects with isolated IGT and NFG. There was no significant difference between the insulin resistance in subjects with isolated IGT and that in subjects with NGT. Indices of beta cell function were severely reduced among subjects with isolated IGT and CGT when compared with those with both isolated IFG and NGT, while subjects with isolated IFG had similar beta-cell indices to subjects with NGT. These data demonstrate that beta-cell dysfunction and insulin resistance contribute differently to the pathogenesis of IFG and IGT among overweight Arab subjects. Copyright 2005 John Wiley & Sons, Ltd.

  13. Mass Spectrometry of Polymer Electrolyte Membrane Fuel Cells

    Directory of Open Access Journals (Sweden)

    Viktor Johánek

    2016-01-01

    Full Text Available The chemical analysis of processes inside fuel cells under operating conditions in either direct or inverted (electrolysis mode and their correlation with potentiostatic measurements is a crucial part of understanding fuel cell electrochemistry. We present a relatively simple yet powerful experimental setup for online monitoring of the fuel cell exhaust (of either cathode or anode side downstream by mass spectrometry. The influence of a variety of parameters (composition of the catalyst, fuel type or its concentration, cell temperature, level of humidification, mass flow rate, power load, cell potential, etc. on the fuel cell operation can be easily investigated separately or in a combined fashion. We demonstrate the application of this technique on a few examples of low-temperature (70°C herein polymer electrolyte membrane fuel cells (both alcohol- and hydrogen-fed subjected to a wide range of conditions.

  14. Mass Spectrometry of Polymer Electrolyte Membrane Fuel Cells.

    Science.gov (United States)

    Johánek, Viktor; Ostroverkh, Anna; Fiala, Roman; Rednyk, Andrii; Matolín, Vladimír

    2016-01-01

    The chemical analysis of processes inside fuel cells under operating conditions in either direct or inverted (electrolysis) mode and their correlation with potentiostatic measurements is a crucial part of understanding fuel cell electrochemistry. We present a relatively simple yet powerful experimental setup for online monitoring of the fuel cell exhaust (of either cathode or anode side) downstream by mass spectrometry. The influence of a variety of parameters (composition of the catalyst, fuel type or its concentration, cell temperature, level of humidification, mass flow rate, power load, cell potential, etc.) on the fuel cell operation can be easily investigated separately or in a combined fashion. We demonstrate the application of this technique on a few examples of low-temperature (70°C herein) polymer electrolyte membrane fuel cells (both alcohol- and hydrogen-fed) subjected to a wide range of conditions.

  15. Phantom bursting is highly sensitive to noise and unlikely to account for slow bursting in beta-cells

    DEFF Research Database (Denmark)

    Pedersen, Morten Gram

    2007-01-01

    Pancreatic beta-cells show bursting electrical activity with a wide range of burst periods ranging from a few seconds, often seen in isolated cells, over tens of seconds (medium bursting), usually observed in intact islets, to several minutes. The phantom burster model [Bertram, R., Previte, J...

  16. Studies of Antibiotic Resistance of Beta-Lactamase Bacteria under Different Nutrition Limitations at the Single-Cell Level.

    Science.gov (United States)

    Wang, Ying; Ran, Min; Wang, Jun; Ouyang, Qi; Luo, Chunxiong

    2015-01-01

    Drug resistance involves many biological processes, including cell growth, cell communication, and cell cooperation. In the last few decades, bacterial drug resistance studies have made substantial progress. However, a major limitation of the traditional resistance study still exists: most of the studies have concentrated on the average behavior of enormous amounts of cells rather than surveying single cells with different phenotypes or genotypes. Here, we report our study of beta-lactamase bacterial drug resistance in a well-designed microfluidic device, which allows us to conduct more controllable experiments, such as controlling the nutrient concentration, switching the culture media, performing parallel experiments, observing single cells, and acquiring time-lapse images. By using GFP as a beta-lactamase indicator and acquiring time-lapse images at the single-cell level, we observed correlations between the bacterial heterogeneous phenotypes and their behavior in different culture media. The feedback loop between the growth rate and the beta-lactamase production suggests that the beta-lactamase bacteria are more resistant in a rich medium than in a relatively poor medium. In the poorest medium, the proportion of dormant cells may increase, which causes a lower death rate in the same generation. Our work may contribute to assaying the antibiotic resistance of pathogenic bacteria in heterogeneous complex media.

  17. Studies of Antibiotic Resistance of Beta-Lactamase Bacteria under Different Nutrition Limitations at the Single-Cell Level.

    Directory of Open Access Journals (Sweden)

    Ying Wang

    Full Text Available Drug resistance involves many biological processes, including cell growth, cell communication, and cell cooperation. In the last few decades, bacterial drug resistance studies have made substantial progress. However, a major limitation of the traditional resistance study still exists: most of the studies have concentrated on the average behavior of enormous amounts of cells rather than surveying single cells with different phenotypes or genotypes. Here, we report our study of beta-lactamase bacterial drug resistance in a well-designed microfluidic device, which allows us to conduct more controllable experiments, such as controlling the nutrient concentration, switching the culture media, performing parallel experiments, observing single cells, and acquiring time-lapse images. By using GFP as a beta-lactamase indicator and acquiring time-lapse images at the single-cell level, we observed correlations between the bacterial heterogeneous phenotypes and their behavior in different culture media. The feedback loop between the growth rate and the beta-lactamase production suggests that the beta-lactamase bacteria are more resistant in a rich medium than in a relatively poor medium. In the poorest medium, the proportion of dormant cells may increase, which causes a lower death rate in the same generation. Our work may contribute to assaying the antibiotic resistance of pathogenic bacteria in heterogeneous complex media.

  18. Histone deacetylase 4 promotes TGF-beta1-induced synovium-derived stem cell chondrogenesis but inhibits chondrogenically differentiated stem cell hypertrophy.

    Science.gov (United States)

    Pei, Ming; Chen, Demeng; Li, Jingting; Wei, Lei

    2009-12-01

    The transforming growth factor-beta (TGF-beta) superfamily members play diverse roles in cartilage development and maintenance. TGF-beta up-regulates chondrogenic gene expression by enhancing transcription factor SRY (sex determining region Y)-box 9 (Sox9) and inhibits osteoblast differentiation by repressing runt-related transcription factor 2 (Runx2). Recently, histone deacetylases (HDACs) were reported to act as negative regulators of chondrocyte hypertrophy. It was speculated that HDAC4 may promote TGF-beta1-induced MSC chondrogenesis. In this study, the adenovirus-mediated HDAC4 gene (Ad.HDAC4) was utilized to infect synovium-derived stem cells (SDSCs). Adenovirus-mediated LacZ (Ad.LacZ) served as a control. The infected cells were centrifuged to form SDSC pellets followed by incubation in a serum-free chondrogenic medium for 15 days with or without 10ng/mL TGF-beta1. Transfection efficiency was determined in SDSCs using Ad.LacZ. Cytotoxicity was measured using lactate dehydrogenase assay. Histology, immunostaining, biochemical analysis, and real-time polymerase chain reaction were performed to assess chondrogenesis at protein and mRNA levels in infected SDSCs. Our data demonstrated that supplementation with TGF-beta1 could initiate and promote SDSC chondrogenesis; however, TGF-beta1 alone was insufficient to fully differentiate SDSCs into chondrocytes. Ad.HDAC4 could be efficiently transfected into SDSCs. Without TGF-beta1 treatment, HDAC4 had no effect on SDSC chondrogenesis; however, in the presence of TGF-beta1, HDAC4 could speed up and maintain a high level of chondrogenesis while down-regulating the hypertrophic marker - type X collagen expression. This study is the first report showing that HDAC4 overexpression promotes TGF-beta1-induced SDSC chondrogenesis but inhibits chondrogenically differentiated stem cell hypertrophy. The mechanism underlying this process needs further investigation.

  19. Glucose- and interleukin-1beta-induced beta-cell apoptosis requires Ca2+ influx and extracellular signal-regulated kinase (ERK) 1/2 activation and is prevented by a sulfonylurea receptor 1/inwardly rectifying K+ channel 6.2 (SUR/Kir6.2) selective potassium channel opener in human islets

    DEFF Research Database (Denmark)

    Maedler, Kathrin; Størling, Joachim; Sturis, Jeppe

    2004-01-01

    for the beta-cell potassium channel SUR1/Kir6.2, on glucose- and IL-1beta-induced apoptosis and impaired function in human beta-cells. Exposure of human islets for 4 days to 11.1 and 33.3 mmol/l glucose, 2 ng/ml IL-1beta, or 10 and 100 micromol/l of the sulfonylurea tolbutamide induced beta-cell apoptosis...

  20. beta. -endorphin augments the cytolytic activity and interferon production of natural killer cells

    Energy Technology Data Exchange (ETDEWEB)

    Mandler, R.N.; Biddison, W.E.; Mandler, R.; Serrate, S.A.

    1986-02-01

    The in vitro effects of the neurohormone ..beta..-endorphin (b-end) on natural killer (NK) activity and interferon (IFN) production mediated by large granular lymphocytes (LGL) were investigated. LGL-enriched fractions from peripheral blood mononuclear cells (PBMC) from normal human volunteers were obtained by fractionation over discontinuous Percoll gradients. LGL were preincubated with or without various concentrations of b-end or the closely related peptides ..cap alpha..-endorphin (a-end), ..gamma..-endorphin (g-end), or D-ALA/sub 2/-..beta..-endorphin (D-ALA/sub 2/-b-end), a synthetic b-end analogue. NK activity was assayed on /sup 51/Cr-labeled K562 target cells. Preincubation of LGL effectors (but not K562 targets) for 2 to 18 hr with concentrations of b-end between 10/sup -7/ M and 10/sup -10/ M produced significant augmentation of NK cytolytic activity (mean percentage increase: 63%). The classic opiate antagonist naloxone blocked the enhancing effect when used at a 100-fold molar excess relative to b-end. These findings demonstrate that b-end enhances NK activity and IFN production of purified LGL, and suggests that b-end might bind to an opioid receptor on LGL that can be blocked by naloxone. These results lend support to the concepts of regulation of the immune response by neurohormones and the functional relationship between the nervous and immune systems.

  1. Photovoltaic Performance of ZnO Nanosheets Solar Cell Sensitized with Beta-Substituted Porphyrin

    Directory of Open Access Journals (Sweden)

    Arumugam Mahesh

    2011-01-01

    Full Text Available The photoanode of dye-sensitized solar cell (DSSC was fabricated using two-dimensional ZnO nanosheets (2D ZnO NSs sensitized with beta-substituted porphyrins photosensitizer, and its photovoltaic performance in solid-state DSSC with TiO2 nanotubes (TiO2 TNs modified poly (ethylene oxide (PEO polymer electrolyte was studied. The ZnO NSs were synthesized through hydrothermal method and were characterized through high-resolution scanning electron microscopy (HRSEM, diffused reflectance spectra (DRS, photoluminescence spectra (PL, and X-ray diffraction (XRD analysis. The crystallinity of the polymer electrolytes was investigated using X-ray diffraction analysis. The photovoltaic performance of the beta-substituted porphyrins sensitized solar cells was evaluated under standard AM1.5G simulated illumination (100 mW cm−2. The efficiency of energy conversion from solar to electrical due to 2D ZnO NSs based DSSCs is 0.13%, which is about 1.6 times higher than that of the control DSSC using ZnO nanoparticles (ZnO NPs as photoanode (0.08%, when TiO2 NTs fillers modified PEO electrolyte was incorporated in the DSSCs. The current-voltage (- and photocurrent-time (- curves proved stable with effective collection of electrons, when the 2D ZnO nanostructured photoanode was introduced in the solid-state DSSC.

  2. Mobility of creatine phosphokinase and beta-enolase in cultured muscle cells.

    Science.gov (United States)

    Arrio-Dupont, M; Foucault, G; Vacher, M; Douhou, A; Cribier, S

    1997-11-01

    The diffusion of beta-enolase and creatine phosphokinase in muscle cells has been studied by modulated fringe pattern photobleaching. Beta-enolase is mobile in the sarcoplasm. At 20 degrees C, the diffusion coefficient is 13.5 +/- 2.5 microm2 s(-1) in the cytosol and 56 microm2 s(-1) in aqueous media. As in the case of dextrans of the same hydrodynamic radius, its mobility is hindered by both the crowding of the fluid phase of the cytoplasm and the screening effect due to myofilaments. A fraction of creatine phosphokinase is mobile in the sarcoplasm. Its diffusion coefficient in the cytosol, 4.5 +/- 1 microm2 s(-1), is lower than that of the dextran of equivalent size. The other fraction (20 to 50%) is very slightly mobile, with an apparent diffusion coefficient varying from 0.0035 to 0.043 microm2 s(-1). This low mobility might be attributed to exchange between free and bound creatine phosphokinase. The bound fraction of the endogenous enzyme was localized by immunocytofluorescence on the cultured muscle cells. Our results favor a localization of bound cytosolic creatine phosphokinase on the M-line and a diffuse distribution in all myotubes.

  3. Naive Pluripotent Stem Cells Derived Directly from Isolated Cells of the Human Inner Cell Mass

    Directory of Open Access Journals (Sweden)

    Ge Guo

    2016-04-01

    Full Text Available Conventional generation of stem cells from human blastocysts produces a developmentally advanced, or primed, stage of pluripotency. In vitro resetting to a more naive phenotype has been reported. However, whether the reset culture conditions of selective kinase inhibition can enable capture of naive epiblast cells directly from the embryo has not been determined. Here, we show that in these specific conditions individual inner cell mass cells grow into colonies that may then be expanded over multiple passages while retaining a diploid karyotype and naive properties. The cells express hallmark naive pluripotency factors and additionally display features of mitochondrial respiration, global gene expression, and genome-wide hypomethylation distinct from primed cells. They transition through primed pluripotency into somatic lineage differentiation. Collectively these attributes suggest classification as human naive embryonic stem cells. Human counterparts of canonical mouse embryonic stem cells would argue for conservation in the phased progression of pluripotency in mammals.

  4. Naive Pluripotent Stem Cells Derived Directly from Isolated Cells of the Human Inner Cell Mass.

    Science.gov (United States)

    Guo, Ge; von Meyenn, Ferdinand; Santos, Fatima; Chen, Yaoyao; Reik, Wolf; Bertone, Paul; Smith, Austin; Nichols, Jennifer

    2016-04-12

    Conventional generation of stem cells from human blastocysts produces a developmentally advanced, or primed, stage of pluripotency. In vitro resetting to a more naive phenotype has been reported. However, whether the reset culture conditions of selective kinase inhibition can enable capture of naive epiblast cells directly from the embryo has not been determined. Here, we show that in these specific conditions individual inner cell mass cells grow into colonies that may then be expanded over multiple passages while retaining a diploid karyotype and naive properties. The cells express hallmark naive pluripotency factors and additionally display features of mitochondrial respiration, global gene expression, and genome-wide hypomethylation distinct from primed cells. They transition through primed pluripotency into somatic lineage differentiation. Collectively these attributes suggest classification as human naive embryonic stem cells. Human counterparts of canonical mouse embryonic stem cells would argue for conservation in the phased progression of pluripotency in mammals. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  5. Studies of the variability of the hepatocyte nuclear factor-1beta (HNF-1beta / TCF2) and the dimerization cofactor of HNF-1 (DcoH / PCBD) genes in relation to type 2 diabetes mellitus and beta-cell function

    DEFF Research Database (Denmark)

    Ek, J; Grarup, N; Urhammer, S A

    2001-01-01

    , and 46 type 2 diabetic patients with an impaired beta-cell function by combined single-strand conformation polymorphism (SSCP) and heteroduplex analysis. Analysis of the promoter and nine exons including intron-exon boundaries of the HNF-1beta gene revealed one novel silent polymorphism and three...... previously reported intronic variants. The silent polymorphism (I91I) was found in one patient with late-onset type 2 diabetes. One of the intronic variant (IVS6+26T-->C) was examined further. Among 584 type 2 diabetic patients the allelic frequency was 13.1% (11.2-15.0%) compared to 11.6% (8.6-14.5%) in 229......Mutations in the homeodomain-containing transcription factor hepatocyte nuclear factor-1beta (HNF-1beta) are known to cause a rare subtype of maturity-onset diabetes of the young (MODY5), which is associated with early-onset progressive non-diabetic renal dysfunction. To investigate whether...

  6. IL-1 beta-induced chemokine and Fas expression are inhibited by suppressor of cytokine signalling-3 in insulin-producing cells

    DEFF Research Database (Denmark)

    Jacobsen, M.L.B.; Ronn, S.G.; Bruun, C.

    2009-01-01

    -induced Fas and chemokine expression in