scholarly journals Cytokine-induced human islet cell death in vitro correlates with a persistently high phosphorylation of STAT-1, but not with NF-κB activation

2012 ◽  
Vol 418 (4) ◽  
pp. 845-850 ◽  
Author(s):  
Henrietta Hindlycke ◽  
Tao Lu ◽  
Nils Welsh
Keyword(s):  
Cell Death ◽  
Islet Cell ◽  
Human Islet

scholarly journals The novel NADPH oxidase 4 selective inhibitor GLX7013114 counteracts human islet cell death in vitro

PLoS ONE ◽  
2018 ◽  
Vol 13 (9) ◽  
pp. e0204271 ◽  
Author(s):  
Xuan Wang ◽  
Andris Elksnis ◽  
Per Wikström ◽  
Erik Walum ◽  
Nils Welsh ◽  
...  
Keyword(s):  
Cell Death ◽  
Nadph Oxidase ◽  
Islet Cell ◽  
Selective Inhibitor ◽  
Human Islet ◽  
The Novel ◽  
Nadph Oxidase 4

Overexpression of the nuclear factor-κB subunit c-Rel protects against human islet cell death in vitro

2009 ◽  
Vol 297 (5) ◽  
pp. E1067-E1077 ◽  
Author(s):  
Dariush Mokhtari ◽  
Andreea Barbu ◽  
Ilir Mehmeti ◽  
Chantal Vercamer ◽  
Nils Welsh
Keyword(s):  
Cell Death ◽  
Islet Cell ◽  
Nuclear Translocation ◽  
Islet Cells ◽  
Human Islet ◽  
Nuclear Fraction ◽  
Nuclear Factor ◽  
Subunit C

The transcription factor nuclear factor (NF)-κB is known to modulate rates of apoptosis and may therefore play a role in the increased β-cell death that occurs in type 1 and type 2 diabetes. The aim of the present investigation was to study the expression of NF-κB subunits in human islet cells and whether overexpression of the NF-κB subunit c-Rel affects islet cell survival. We detected expression of p65, Rel-B, p50, p105, p52, and the ribosomal protein S3 (rpS3) in human islet cells. Among these, only p65 and rpS3 were translocated from the cytosolic to the nuclear fraction in response to cytokines. Interestingly, rpS3 participated in p65 binding to the κB-element in gel shift analysis experiments. We observed cytoplasmic c-Rel expression in vivo in 6J mice, and signs of nuclear translocation in β-cells of infiltrated nonobese diabetic islets. Human islet cells were also dispersed by trypsin treatment and transduced with a c-Rel adenoviral vector. This resulted in increased expression of c-Rel and inhibitory factor κB, increased κB-binding activity, and augmented protein levels of Bcl-XL, c-IAP2, and heat shock protein 72. c-Rel expression in human islet cells protected against cytokine-induced caspase 3 activation and cell death. c-Rel protected also against streptozotocin- and H2O2-induced cell death, in both intact rat islets and human islet cells. We conclude that rpS3 participates in NF-κB signaling and that a genetic increase in the activity of the NF-κB subunit c-Rel results in protection against cell death in human islets.

scholarly journals Pharmacological Inhibition of NOX4 Improves Mitochondrial Function and Survival in Human Beta-Cells

Biomedicines ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 1865
Author(s):  
Andris Elksnis ◽  
Jing Cen ◽  
Per Wikström ◽  
Per-Ola Carlsson ◽  
Nils Welsh
Keyword(s):  
Cell Death ◽  
Beta Cell ◽  
Insulin Release ◽  
Mitochondrial Function ◽  
High Glucose ◽  
Human Islet ◽  
Sodium Palmitate ◽  
Nadph Oxidase 4

Previous studies have reported beneficial effects of NADPH oxidase 4 (NOX4) inhibition on beta-cell survival in vitro and in vivo. The mechanisms by which NOX4 inhibition protects insulin producing cells are, however, not known. The aim of the present study was to investigate the effects of a pharmacological NOX4 inhibitor (GLX7013114) on human islet and EndoC-βH1 cell mitochondrial function, and to correlate such effects with survival in islets of different size, activity, and glucose-stimulated insulin release responsiveness. We found that maximal oxygen consumption rates, but not the rates of acidification and proton leak, were increased in islets after acute NOX4 inhibition. In EndoC-βH1 cells, NOX4 inhibition increased the mitochondrial membrane potential, as estimated by JC-1 fluorescence; mitochondrial reactive oxygen species (ROS) production, as estimated by MitoSOX fluorescence; and the ATP/ADP ratio, as assessed by a bioluminescent assay. Moreover, the insulin release from EndoC-βH1 cells at a high glucose concentration increased with NOX4 inhibition. These findings were paralleled by NOX4 inhibition-induced protection against human islet cell death when challenged with high glucose and sodium palmitate. The NOX4 inhibitor protected equally well islets of different size, activity, and glucose responsiveness. We conclude that pharmacological alleviation of NOX4-induced inhibition of beta-cell mitochondria leads to increased, and not decreased, mitochondrial ROS, and this was associated with protection against cell death occurring in different types of heterogeneous islets. Thus, NOX4 inhibition or modulation may be a therapeutic strategy in type 2 diabetes that targets all types of islets.

scholarly journals A Clinically Applicable Positive Allosteric Modulator of GABA Receptors Promotes Human β-Cell Replication and Survival as well as GABA’s Ability to Inhibit Inflammatory T Cells

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Jide Tian ◽  
Hoa Dang ◽  
Nataliya Karashchuk ◽  
Irvin Xu ◽  
Daniel L. Kaufman
Keyword(s):  
T Cell ◽  
Cell Survival ◽  
Islet Cell ◽  
Cell Mass ◽  
T Cell Responses ◽  
Human Islet ◽  
Cell Replication ◽  
Cell Responses ◽  
Autoreactive T Cell

A major goal of T1D research is to develop new approaches to increase β-cell mass and control autoreactive T cell responses. GABAA-receptors (GABAA-Rs) are promising drug targets in both those regards due to their abilities to promote β-cell replication and survival, as well as inhibit autoreactive T cell responses. We previously showed that positive allosteric modulators (PAMs) of GABAA-Rs could promote rat β-cell line INS-1 and human islet cell replication in vitro. Here, we assessed whether treatment with alprazolam, a widely prescribed GABAA-R PAM, could promote β-cell survival and replication in human islets after implantation into NOD/scid mice. We observed that alprazolam treatment significantly reduced human islet cell apoptosis following transplantation and increased β-cell replication in the xenografts. Evidently, the GABAA-R PAM works in conjunction with GABA secreted from β-cells to increase β-cell survival and replication. Treatment with both the PAM and GABA further enhanced human β-cell replication. Alprazolam also augmented the ability of suboptimal doses of GABA to inhibit antigen-specific T cell responses in vitro. Thus, combined GABAA-R agonist and PAM treatment may help control inflammatory immune responses using reduced drug dosages. Together, these findings suggest that GABAA-R PAMs represent a promising drug class for safely modulating islet cells toward beneficial outcomes to help prevent or reverse T1D and, together with a GABAA-R agonist, may have broader applications for ameliorating other disorders in which inflammation contributes to the disease process.

Effects of Streptozotocin on In Vitro Long-Term Cultured Human Islet Cell Monolayers

2008 ◽  
Vol 40 (2) ◽  
pp. 427-429
Author(s):  
P. Montanucci ◽  
G. Basta ◽  
L. Racanicchi ◽  
R. Calafiore
Keyword(s):  
Islet Cell ◽  
Human Islet ◽  
Cell Monolayers

scholarly journals Dissecting mechanisms of human islet differentiation and maturation through epigenome profiling

2019 ◽  
Author(s):  
Juan R. Alvarez-Dominguez ◽  
Julie Donaghey ◽  
Jennifer H. R. Kenty ◽  
Niloofar Rasouli ◽  
Aharon Helman ◽  
...  
Keyword(s):  
Stem Cells ◽  
Cell Fate ◽  
Pancreatic Islet ◽  
Islet Cell ◽  
Islet Cells ◽  
Chromatin Accessibility ◽  
Human Islet ◽  
Human Stem Cells ◽  
Insulin Synthesis

SUMMARYInvestigating pancreatic islet differentiation from human stem cells in vitro provides a unique opportunity to dissect mechanisms that operate during human development in utero. We developed methods to profile DNA methylation, chromatin accessibility, and histone modifications from pluripotent stem cells to mature pancreatic islet cells, uncovering widespread epigenome remodeling upon endocrine commitment. Key lineage-defining loci are epigenetically primed before activation, foreshadowing cell fate commitment, and we show that priming of α-cell-specific enhancers steers polyhormonal cells toward an α-cell fate. We further dissect pioneer factors and core regulatory circuits across islet cell differentiation and maturation stages, which identify LMX1B as a key regulator of in vitro-derived endocrine progenitors. Finally, by contrasting maturing stem cell-derived to natural β-cells, we discover that circadian metabolic cycles trigger rhythmic control of insulin synthesis and release and promote mature insulin responsiveness via an increased glucose threshold. These findings form a basis for understanding mechanisms orchestrating human islet cell specification and maturation.

scholarly journals Co-localization of nestin and insulin and expression of islet cell markers in long-term human pancreatic nestin-positive cell cultures

2004 ◽  
Vol 183 (3) ◽  
pp. 455-467 ◽  
Author(s):  
Silvya Stuchi Maria-Engler ◽  
Maria Lúcia C Corrêa-Giannella ◽  
Letícia Labriola ◽  
Karin Krogh ◽  
Christian Colin ◽  
...  
Keyword(s):  
Cell Cultures ◽  
Islet Cell ◽  
Islet Cells ◽  
Human Islet ◽  
Β Cells ◽  
Short Term ◽  
Cell Markers ◽  
Insulin Expression

Strategies to differentiate progenitor cells into β cells in vitro have been considered as an alternative to increase β cell availability prior to transplantation. It has recently been suggested that nestin-positive cells could be multipotential stem cells capable of expressing endocrine markers upon specific stimulation; however, this issue still remains controversial. Here, we characterized short- and long-term islet cell cultures derived from three different human islet preparations, with respect to expression of nestin and islet cell markers, using confocal microscopy and semi-quantitative RT-PCR. The number of nestin-positive cells was found to be strikingly high in long-term cultures. In addition, a large proportion (49.7%) of these nestin-positive cells, present in long-term culture, are shown to be proliferative, as judged by BrdU incorporation. The proportion of insulin-positive cells was found to be high in short-term (up to 28 days) cultures and declined thereafter, when cells were maintained in the presence of 10% serum, concomitantly with the decrease in insulin and PDX-1 expression. Interestingly, insulin and nestin co-expression was observed as a rare event in a small proportion of cells present in freshly isolated human islets as well as in purified islet cells cultured in vitro for long periods of time. In addition, upon long-term subculturing of nestin-positive cells in 10% serum, we observed reappearance of insulin expression at the mRNA level; when these cultures were shifted to 1% serum for a month, expression of insulin, glucagon and somatostatin was also detected, indicating that manipulating the culture conditions can be used to modulate the nestin-positive cell’s fate. Attempts to induce cell differentiation by plating nestin-positive cells onto Matrigel revealed that these cells tend to aggregate to form islet-like clusters, but this is not sufficient to increase insulin expression upon short-term culture. Our data corroborate previous findings indicating that, at least in vitro, nestin-positive cells may undergo the early stages of differentiation to an islet cell phenotype and that long-term cultures of nestin-positive human islet cells may be considered as a potential source of precursor cells to generate fully differentiated/ functional β cells.

Comparison of cellular and medium insulin and GABA content as markers for living β-cells

2005 ◽  
Vol 288 (2) ◽  
pp. E307-E313 ◽  
Author(s):  
Chen Wang ◽  
Zhidong Ling ◽  
Daniel Pipeleers
Keyword(s):  
Cell Death ◽  
Islet Cell ◽  
Cellular Localization ◽  
Gaba Release ◽  
Human Islet ◽  
Nitric Oxide Donor ◽  
Cell Phenotype ◽  
Β Cells ◽  
Β Cell ◽  
Gaba Content

Experimental and therapeutic use of islet cell preparations could benefit from assays that measure variations in the mass of living β-cells. Because processes of cell death can be followed by depletion and/or discharge of cell-specific substances, we examined whether in vitro conditions of β-cell death resulted in changes in tissue and medium content of insulin and of γ-aminobutyric acid (GABA), two β-cell-specific compounds with different cellular localization and turnover. Exposure of rat purified β-cells to streptozotocin (5 mM, 120 min) or to the nitric oxide donor GEA-3162 (GEA; 50 μM, 120 min) caused 80% necrosis within 24 h; at the end of this period, cellular insulin content was not significantly decreased, but cellular GABA content was reduced by 70%; when cultured at basal glucose (6 mM), the toxin-exposed cells did not discharge less insulin but released 80% less GABA in the period 8–24 h. As in rat β-cell purification, GABA comigrated with insulin during human islet cell isolation. Twenty-four hours after GEA (500 μM, 120 min), human islet cell preparations exhibited 90% dead cells and a 45 and 90% reduction, respectively, in tissue insulin and GABA content; in the period 9–24 h, insulin discharge in the medium was not reduced, but GABA release was decreased by 90%. When rat β-cells were cultured for 24 h with nontoxic interleukin (IL)-1β concentrations that suppressed glucose-induced insulin release, cellular GABA content was not decreased and GABA release increased by 90% in the period 8–24 h. These data indicate that a reduction in cellular and medium GABA levels is more sensitive than insulin as a marker for the presence of dead β-cells in isolated preparations. Pancreatic GABA content also rapidly decreased after streptozotocin injection and remained unaffected by 12 h of hyperglycemia. At further variance with insulin, GABA release from living β-cells depends little on its cellular content but increases with IL-1β-induced alterations in β-cell phenotype.

scholarly journals Repurposing Lesogaberan to Promote Human Islet Cell Survival andβ-Cell Replication

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Jide Tian ◽  
Hoa Dang ◽  
Angela Hu ◽  
Willem Xu ◽  
Daniel L. Kaufman
Keyword(s):  
Cell Survival ◽  
Islet Cell ◽  
Oral Treatment ◽  
Human Islet ◽  
Drug Candidate ◽  
Gamma Aminobutyric Acid ◽  
Cell Replication ◽  
Long Term Treatment

The activation ofβ-cell’s A- and B-type gamma-aminobutyric acid receptors (GABAA-Rs and GABAB-Rs) can promote their survival and replication, and the activation ofα-cell GABAA-Rs promotes their conversion intoβ-cells. However, GABA and the most clinically applicable GABA-R ligands may be suboptimal for the long-term treatment of diabetes due to their pharmacological properties or potential side-effects on the central nervous system (CNS). Lesogaberan (AZD3355) is a peripherally restricted high-affinity GABAB-R-specific agonist, originally developed for the treatment of gastroesophageal reflux disease (GERD) that appears to be safe for human use. This study tested the hypothesis that lesogaberan could be repurposed to promote human islet cell survival andβ-cell replication.Treatment with lesogaberan significantly enhanced replication of human islet cellsin vitro, which was abrogated by a GABAB-R antagonist. Immunohistochemical analysis of human islets that were grafted into immune-deficient mice revealed that oral treatment with lesogaberan promoted humanβ-cell replication and islet cell survivalin vivoas effectively as GABA (which activates both GABAA-Rs and GABAB-Rs), perhaps because of its more favorable pharmacokinetics. Lesogaberan may be a promising drug candidate for clinical studies of diabetes intervention and islet transplantation.

In Vitro–Cultured Human Islet Cell Monolayers: Stemness Markers and Insulin Recovery upon Streptozotocin Exposure

2009 ◽  
Vol 15 (12) ◽  
pp. 3931-3942 ◽  
Author(s):  
Pia Montanucci ◽  
Giuseppe Basta ◽  
Riccardo Calafiore
Keyword(s):  
Islet Cell ◽  
Human Islet ◽  
Cell Monolayers
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