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 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.

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

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.

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 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

scholarly journals Monocyte long-term cultivation on microvascular endothelial cell monolayers: morphologic and phenotypic characterization and comparison with monocytes cultured on tissue culture plastic

Blood ◽  
1989 ◽  
Vol 73 (3) ◽  
pp. 818-826 ◽  
Author(s):  
RR Schumann ◽  
J van der Bosch ◽  
S Ruller ◽  
M Ernst ◽  
M Schlaak
Keyword(s):  
Endothelial Cell ◽  
Cultured Cells ◽  
Antigen Expression ◽  
Phenotypic Characterization ◽  
Microvascular Endothelial Cell ◽  
Cell Monolayers ◽  
Microvascular Endothelial ◽  
Distinct Morphology

Abstract Human monocytes were cultured on monolayers of a newly established microvascular endothelial cell strain. As compared to monocytes cultured on plastic, these endothelium-“derived” monocytes (EDM) showed distinct morphology, higher motility, and different antigen-expression pattern for several surface markers, as detected by cytofluorimetry. The MO-1- and the Leu-M1-marker were maintained on EDMs while they were lost on plastic-cultured cells. The MAX 1–26-termed markers failed to increase on EDMs, in contrast to plastic-cultured monocytes. For seven additional markers, expression after two weeks in vitro was higher on EDMs than on plastic-cultured monocytes. Functionally EDMs showed typical monocyte/macrophage behavior and were easily removable from the culture system for further experimentation. Our data suggest that monocytes cultured on microvascular endothelial cells are maintained for several weeks in a more physiologic state than monocytes cultured on plastic.

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 Porous Optically Transparent Cellulose Acetate Scaffolds for Biomimetic Blood-Brain Barrierin vitro Models

2021 ◽  
Vol 9 ◽  
Author(s):  
Attilio Marino ◽  
Micol Baronio ◽  
Umberto Buratti ◽  
Elisa Mele ◽  
Gianni Ciofani
Keyword(s):  
Cellulose Acetate ◽  
Optical Transmittance ◽  
Cell Monolayers ◽  
Blood Brain ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene ◽  
Cell Invasiveness ◽  
Potential Exploitation

In vitro blood-brain barrier (BBB) models represent an efficient platform to conduct high-throughput quantitative investigations on BBB crossing ability of different drugs. Such models provide a closed system where different fundamental variables can be efficaciously tuned and monitored, and issues related to scarce accessibility of animal brains and ethics can be addressed. In this work, we propose the fabrication of cellulose acetate (CA) porous bio-scaffolds by exploiting both vapor-induced phase separation (VIPS) and electrospinning methods. Parameters of fabrication have been tuned in order to obtain porous and transparent scaffolds suitable for optical/confocal microscopy, where endothelial cell monolayers are allowed to growth thus obtaining biomimetic BBB in vitro models. Concerning VIPS-based approach, CA membranes fabricated using 25% H2O + 75% EtOH as non-solvent showed submicrometer-scale porosity and an optical transmittance comparable to that one of commercially available poly(ethylene terephthalate) membranes. CA membranes fabricated via VIPS have been exploited for obtaining multicellular BBB models through the double seeding of endothelial cells and astrocytes on the two surfaces of the membrane. Electrospun CA substrates, instead, were characterized by micrometer-sized pores, and were unsuitable for double seeding approach and long term studies. However, the potential exploitation of the electrospun CA substrates for modeling blood-brain-tumor barrier and studying cell invasiveness has been speculated. The features of the obtained models have been critically compared and discussed for future applications.

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