Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011854 (type 1 diabetes)
 20,749 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Engineered insulinoma cell lines may represent an alternative to isolated islets for transplantation therapy of type 1 diabetes. Success of this approach may require development of cell lines that can withstand cytokine-mediated damage. To this end, we have cultured INS-1 insulinoma cells in increasing concentrations of interleukin-1beta (IL-1beta) + gamma-interferon (IFN-gamma), with approximate weekly iterations over an 8-week period. Based on the C,N diphenyl-N'-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium+ ++ bromide (MTT) viability assay, the selected cells, termed INS-1res, were 100% viable after 5 days of treatment with 10 ng/ml of IL-1beta. These cells were also 78 +/- 1.2% viable after 5 days of exposure to the combination of 10 ng/ml IL-1beta and 100 U/ml IFN-gamma, whereas parental INS-1 cells treated in the same manner were only 0.3 +/- 0.03% viable. INS-1res cells were also resistant to treatment with supernatants from activated rat peripheral blood mononuclear cells, whereas only 20% of parental INS-1 cells survived such treatment. The resistance to IL-1beta conferred by this procedure was stable, whereas the partial resistance to IFN-gamma was transient but reinducible by culture in the presence of cytokines. Stable transfection of INS-1res cells with a plasmid containing the human insulin cDNA and expansion of the transfected colonies in the absence of cytokines produced cell lines that were on average more resistant to IL-1beta + IFN-gamma (53 +/- 11%) than similarly transfected clones derived from parental INS-1 cells (15 +/- 7%). Importantly, several INS-1res-derived clones retained the capacity to secrete insulin in response to glucose concentrations over the normal physiological range. With regard to the mechanism by which selection was conferred, we found normal levels of IFN-gamma receptor mRNA, but a 60% reduction in expression of the IL-1 receptor type I (IL-1RI) in INS-1res cells compared with parental INS-1 cells. IL-1beta signaling through p38 MAP kinase was found to be normal in INS-1res cells, suggesting that their expression of IL-1RI is sufficient to maintain cytokine action. However, normal IL-1beta-mediated translocation of NF-kappaB and induction of inducible nitric oxide synthase expression and nitric oxide production was severely impaired in the INS-1res cell lines, suggesting a mechanism for the IL-1beta resistance. In sum, this study defines a strategy for isolation of cytokine-resistant beta-cell lines and provides a new system for studying the mechanisms by which such resistance can be achieved.
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PMID:Selection of insulinoma cell lines with resistance to interleukin-1beta- and gamma-interferon-induced cytotoxicity. 1087 Nov 93

Pancreatic islet transplantation in humans is a promising alternative for substitutive insulin therapy of IDDM (Insulin Dependent Diabetes Mellitus). Storage of harvested organs is a one of the most important factors, which influence efficacy of islet isolation process. In this sense, appropriate pancreas storage is the main point the successful pancreatic islet isolation. The purpose of the present study was to find out whether lidocaine, a well known membrane stabilizer and PLA2 (phospholipase A2) inhibitor could be applied in pancreas preservation for protection of endo- and exocrine pancreatic tissue from cells damage which occurs during and after storage. For this purpose, the effects of lidocaine on 1) viability and 2) endocrine function of pancreatic islets, isolated from pancreases exposed to cold ischemia, were investigated in this study. Our study showed hat lidocaine, injected intraductally before pancreas harvesting, improves efficacy of islet isolation. We found that the yields of islets in the groups treated with lidocaine were significantly higher when compared with controls. Glucose challenge test performed on these islets indicated that after the treatment with lidocaine, islets were more sensitive to glucose stimulation when compared with control islets, although the metabolic activity estimated by MTT test was comparable in both groups. In summary, donor pretreatment with lidocaine seems to be the safe method of protection of preserved pancreases from cell damage, caused by membranes destruction during cold ischemia.
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PMID:Lidocaine as a protective agent during pancreas cold ischemia. 1124 52

Immunoprotection of pancreatic islets for successful allo- or xenotransplantation without chronic immunosuppression is an attractive, but still elusive, approach for curing type 1 diabetes. It was recently shown that, even in the absence of fibrotic overgrowth, other factors, mainly insufficient nutrition to the core of the islets, represent a major barrier for long-term survival of intraperitoneal microencapsulated islet grafts. The use of dispersed cells might contribute to solve this problem due to the conceivably easier nutritional support to the cells. In the present study, purified bovine islets, prepared by collagenase digestion and density gradient purification, and dispersed bovine islet cells, obtained by trypsin and DNAsi (viability > 90%), were entrapped into either 2% (w/v) sodium alginate (commonly used for encapsulation purposes) or (dispersed islet cells only) macroporous gelatin microcarriers (CulthiSpher-S, commonly used for the production of biologicals by animal cells). Insulin release studies in response to glucose were performed within 1 week and after 1 month from preparation of the varying systems and showed no capability of dispersed bovine islet cells within sodium alginate microcapsules to sense glucose concentration changes. On the contrary, bovine islet cells entrapped in CulthiSpher-S microcarriers showed maintained capacity of increasing insulin secretion upon enhanced glucose concentration challenge. In this case, insulin release was approximately 60% of that from intact bovine islets within sodium alginate microcapsules. MTT and hematoxylineosin staining of islet cell-containing microcarriers showed the presence of viable and metabolically active cells throughout the study period. This encouraging functional data prompted us to test whether the microcarriers could be immunoisolated for potential use in transplantation. The microcarriers were embedded within 3% sodium alginate, which was then covered with a poly-L-lysine layer and a final outer alginate layer. Maintained insulin secretion function of this system was observed, which raises the possibility of using microencapsulated CulthiSpher-S microcarriers, containing dispersed pancreatic islet cells, in experimental transplantation studies.
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PMID:Entrapment of dispersed pancreatic islet cells in CultiSpher-S macroporous gelatin microcarriers: Preparation, in vitro characterization, and microencapsulation. 1174 53

Proinflammatory cytokine-mediated pancreatic beta-cell dysfunction is a key pathological event in type I diabetes mellitus. Lisofylline (LSF), an anti-inflammatory agent, has been shown to protect pancreatic islets from IL-1 beta-induced inhibitory effects on insulin release. However, the mechanism of LSF action is not known. Increasing evidence suggests that the mitochondria play an important role in regulating the beta-cell insulin release capacity and the control of cellular viability. To examine the direct effects of LSF on beta-cells, insulin-secreting INS-1 cells were exposed to a combination of recombinant IL-1 beta, TNF alpha, and IFN gamma with or without LSF for 18 h. Basal and glucose-stimulated static insulin release were measured using RIA. INS-1 cell viability was determined using in situ terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling and LIVE/DEAD dual fluorescence labeling. To evaluate INS-1 mitochondrial function, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) metabolism, change in mitochondrial membrane potential, and intracellular ATP levels were assessed. Cytokine addition reduced basal (7.8 +/- 0.30 vs. 10.0 +/- 0.46 ng/ml.h; P < 0.005), glucose-stimulated insulin secretion (11.6 +/- 0.86 vs. 17.4 +/- 1.86 ng/ml.h; P < 0.005), and MTT metabolism in INS-1 cells. Over 40% of the cytokine-treated beta-cells exhibited nuclear DNA breakage, whereas the control cell death rate remained at 1-2%. Simultaneous application of LSF and cytokines to INS-1 cells restored insulin secretion, MTT metabolism, mitochondrial membrane potential, and cell viability to control levels. LSF increased beta-cell MTT metabolism as well as insulin release and glucose responsiveness. In summary, proinflammatory cytokines lead to a reduction of glucose-induced insulin secretion, mitochondrial activity, and viability in INS-1 cells. LSF at concentrations achievable in vivo protected beta-cells from the cytokine effects. The mechanism of LSF-induced protection may be by promoting mitochondrial metabolism.
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PMID:Lisofylline, a novel antiinflammatory agent, protects pancreatic beta-cells from proinflammatory cytokine damage by promoting mitochondrial metabolism. 1202 Nov 99

Coxsackie B virus (CVB-5) infections potentially trigger and accelerate pancreatic beta cell damage leading to type 1 diabetes. In vivo, all viruses face natural resistance mediated by various host factors which restrict the progression of infection. Thus, the aims of this study were to generate a tissue culture model of restricted coxsackie B virus infection in primary islet cells by preventing the production of viral progeny with a selective inhibitor of viral RNA replication and to investigate the mechanisms of virus-induced islet cell death during productive and restricted infective conditions. Cultured foetal porcine islet cells were infected effectively with the prototype strain of coxsackievirus B5 (CVB-5). Nuclear viability stainings and electron microscopy showed productive infection to result in dominantly necrotic cell death with additional slight induction of apoptosis during the 7 days of follow-up. The restricted conditions were created by addition of guanidine-hydrochloride (G-HCl) into culture medium. At 1 mM concentration, it significantly protected the infected cells from necrosis and thus maintained high viability. This was associated with increased significantly apoptosis. In perifusion analysis, the cellular ability to release insulin was reduced, although the metabolic integrity was preserved as shown by MTT-analysis and cellular ATP levels. These data show that restriction of CVB-5 replication with G-HCl protects islet cells against virus-induced necrosis. However, restriction of viral replication shifts the mechanism of cell death from necrosis toward apoptosis. A slowly progressing subclinical infection of islets could thus lead to increased beta-cell apoptosis.
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PMID:Mechanisms of beta cell death during restricted and unrestricted enterovirus infection. 1474 69

Protection of pancreatic islet beta cells from pro-inflammatory cytokines-induced cell death and functional impairment is a key issue in developing therapeutic interventions of type 1 diabetes mellitus including islet transplantation. The effects of IL-6 on the protection of beta cells in vitro and in vivo were examined. Freshly isolated islets or MIN6 beta cells, when pre-incubated with IL-6, showed significantly higher viabilities measured by MTT assay and FACS analysis of PI stained cells against pro-apoptotic signaling delivered by IL-1beta, TNF-alpha and IFN-gamma. Insulin secretory function was also significantly protected in static culture with glucose and KCl stimulation. In vivo assessment using marginal mass syngeneic islet transplantation in mouse model revealed IL-6 conferred significantly better blood glucose control and graft survival rate over 50 days. Conclusively, IL-6 protects pancreatic islets or beta-cells from inflammatory cytokines-induced cell death and functional impairment both in vitro and in vivo. This strategy could be exploited in the clinical setting to maintain functional islet mass.
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PMID:IL-6 protects pancreatic islet beta cells from pro-inflammatory cytokines-induced cell death and functional impairment in vitro and in vivo. 1520 28

Brx-019 (acetic acid 3,6a,9-triacetoxy-6, 6a,7,11b-tetrahydro-indeno [2,1-c] chromen-10-yl ester) was derived from brazilin (CAS 474-07-7) during a trial designed to search for immunomodulators with lower toxicity and more effective immunomodulating activities than brazilin. Brx-019 was selected as a potential immunomodulator based on its effects on Concanavalin A (Con A)-induced proliferation of splenocytes and the 3-[14,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. Intraperitoneally administered Brx-019 significantly improved delayed type hypersensitivity and increased immunoglobulin M (IgM) plaque forming cells (PFCs) in multiple low dose streptozotocin-induced diabetic mice (MLDS-diabetic mice). This finding suggests that Brx-019 may increase suppressed humoral and cell-mediated immunity in type 1 diabetes. Brx-019 also significantly increased Con A- or alloantigen-induced proliferation of splenocytes, Con A-induced interleukin 2 (IL-2) production from splenocytes, and IL-2-induced proliferation of Con A-activated splenocytes in MLDS-diabetic mice. These results suggest that Brx-019 might improve immunity in diabetic mice by increasing IL-2 production in splenocytes and responsiveness of splenocytes to IL-2, which were suppressed in MLDS-diabetes.
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PMID:Effects of Brx-019 (acetic acid 3,6a,9-triacetoxy-6,6a,7, 11b-tetrahydro-indeno [2,1-c] chromen-10-yl ester), a Brazilin derivative, on T cell-mediated immune responses in multiple low dose streptozotocin-induced diabetic C57BL/6 male mice. 1622 19

IDDM results from pancreatic beta cell destruction by islet-reactive T cells, a process that involves beta cell apoptosis. Fas-FasL pathway plays a major role in pancreatic beta cell death. Fas-associated death domain protein (FADD), the component of the tumor necrosis factor receptor type 1 (TNFR1) and Fas signaling complexes, is involved in TNFR1- and Fas-induced apoptosis. Inhibiting the function of FADD will lead to blocking downstream apoptosis signal, which protects pancreatic beta cells from destruction by Fas-FasL pathway. In this study we constructed eukaryotic expressing vector of fusional protein FADDdel-GFP named pFADDdel-GFP. After pFADDdel-GFP was transfected into NIT, the expression of FADDdel-GFP in NIT was detected by fluorescence microscopy and the resistance of NIT transfected with pFADDdel-GFP to cytotoxicity mediated by special T cells was detected by FACS and MTT. The results showed that NIT modified by pFADDdel-GFP obviously resisted cytotoxicity mediated by special T cells. Therefore, it may be useful in the prevention or treatment of IDDM by intervening Fas-FasL pathway.
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PMID:FADDdel-GFP modified mouse insulinoma cells counteract the cytotoxicity of reactive T cells. 1628 99

The purpose of current experiment is the generation of insulin-producing human mesenchymal stem cells as therapeutic source for the cure of type 1 diabetes. Type 1 diabetes is generally caused by insulin deficiency accompanied by the destruction of islet beta-cells. In various trials for the treatment of type 1 diabetes, cell-based gene therapy using stem cells is considered as one of the most useful candidate for the treatment. In this experiment, human mesenchymal stem cells were transduced with AAV which is containing furin-cleavable human preproinsulin gene to generate insulin-producing cells as surrogate beta-cells for the type 1 diabetes therapy. In the rAAV production procedure, rAAV was generated by transfection of AD293 cells. Human mesenchymal stems cells were transduced using rAAV with a various multiplicity of infection. Transduction of recombinant AAV was also tested using beta-galactosidse expression. Cell viability was determined by using MTT assay to evaluate the toxicity of the transduction procedure. Expression and production of Insulin were tested using reverse transcriptase-polymerase chain reaction and immunocytochemistry. Secretion of human insulin and C-peptide from the cells was assayed using enzyme-linked immunosorbent assay. Production of insulin and C-peptide from the test group represented a higher increase compared to the control group. In this study, we examined generation of insulin-producing cells from mesenchymal stem cells by genetic engineering for diabetes therapy. This work might be valuable to the field of tissue engineering for diabetes treatment.
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PMID:Generation of insulin-producing human mesenchymal stem cells using recombinant adeno-associated virus. 1732 53

Insulin-dependent diabetes mellitus (IDDM) is an organ-specific autoimmune disorder triggered by autoreactive T cells directed to pancreas beta-cell antigens. In this disorder, more than 90% of beta cells are destroyed. Cell death may be mediated via soluble or membrane-bound cell death ligands. One of these ligands may be tumour necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL), a member of the TNF-alpha superfamily. In the present study, we examined whether TRAIL had cytotoxic effects on adult rat pancreas beta cell cultures and INS1-E rat insulinoma cell line cultures or not. In this study, cell destruction models were built with TRAIL concentrations of 10, 100 and 1000 ng. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test was used for evaluating cell viability. It was detected that cell cultures with TRAIL added showed no differences statistically when compared with control cultures containing no toxic additions. These results showed that TRAIL did not have significant cytotoxic effects on pancreas beta cell culture and INS-1E rat insulinoma cell line cultures. Detection of the expression of TRAIL receptors and natural apoptosis inhibitor proteins will be favourable to investigate the resistance mechanisms to TRAIL-induced cell death in this cell culture system.
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PMID:The effect of TRAIL molecule on cell viability in in vitro beta cell culture. 1753 Apr 68


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