scholarly journals Functional Plasticity of the Human Infant β-Cell Exocytotic Phenotype

Endocrinology ◽  
2013 ◽  
Vol 154 (4) ◽  
pp. 1392-1399 ◽  
Author(s):  
Jocelyn E. Manning Fox ◽  
Karen Seeberger ◽  
Xiao Qing Dai ◽  
James Lyon ◽  
Aliya F. Spigelman ◽  
...  
Keyword(s):  
Islet Cells ◽  
Human Infant ◽  
Β Cells ◽  
Β Cell ◽  
Syntaxin 1A ◽  
Human Infants ◽  
Functional Maturation ◽  
Elevated Expression ◽  
Experimental Approaches ◽  
Insulin Staining

Abstract Our understanding of adult human β-cells is advancing, but we know little about the function and plasticity of β-cells from infants. We therefore characterized islets and single islet cells from human infants after isolation and culture. Although islet morphology in pancreas biopsies was similar to that in adults, infant islets after isolation and 24–48 hours of culture had less insulin staining, content, and secretion. The cultured infant islets expressed pancreatic and duodenal homeobox 1 and several (Glut1, Cav1.3, Kir6.2) but not all (syntaxin 1A and synaptosomal-associated protein 25) markers of functional islets, suggesting a loss of secretory phenotype in culture. The activity of key ion channels was maintained in isolated infant β-cells, whereas exocytosis was much lower than in adults. We examined whether a functional exocytotic phenotype could be reestablished under conditions thought to promote β-cell differentiation. After a 24- to 28-day expansion and maturation protocol, we found preservation of endocrine markers and hormone expression, an increased proportion of insulin-positive cells, elevated expression of syntaxin 1A and synaptosomal-associated protein 25, and restoration of exocytosis to levels comparable with that in adult β-cells. Thus, human infant islets are prone to loss of their exocytotic phenotype in culture but amenable to experimental approaches aimed at promoting expansion and functional maturation. Control of exocytotic protein expression may be an important mechanism underlying the plasticity of the secretory machinery, an increased understanding of which may lead to improved regenerative approaches to treat diabetes.

scholarly journals MAFA and T3 Drive Maturation of Both Fetal Human Islets and Insulin-Producing Cells Differentiated From hESC

2015 ◽  
Vol 100 (10) ◽  
pp. 3651-3659 ◽  
Author(s):  
Cristina Aguayo-Mazzucato ◽  
Amanda DiIenno ◽  
Jennifer Hollister-Lock ◽  
Christopher Cahill ◽  
Arun Sharma ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Islet Cells ◽  
Embryonic Stem ◽  
Human Islets ◽  
Insulin Content ◽  
Β Cells ◽  
Β Cell ◽  
Functional Maturation ◽  
Glucose Responsiveness

Context: Human embryonic stem cells (hESCs) differentiated toward β-cells and fetal human pancreatic islet cells resemble each other transcriptionally and are characterized by immaturity with a lack of glucose responsiveness, low levels of insulin content, and impaired proinsulin-to-insulin processing. However, their response to stimuli that promote functionality have not been compared. Objective: The objective of the study was to evaluate the effects of our previous strategies for functional maturation developed in rodents in these two human models of β-cell immaturity and compare their responses. Design, Settings, Participants, and Interventions: In proof-of-principle experiments using either adenoviral-mediated overexpression of V-Maf avian musculoaponeurotic fibrosarcoma oncogene homolog A (MAFA) or the physiologically driven path via thyroid hormone (T3) and human fetal islet-like cluster (ICC) functional maturity was evaluated. Then the effects of T3 were evaluated upon the functional maturation of hESCs differentiated toward β-cells. Main Outcome Measures: Functional maturation was evaluated by the following parameters: glucose responsiveness, insulin content, expression of the mature β-cell transcription factor MAFA, and proinsulin-to-insulin processing. Results: ICCs responded positively to MAFA overexpression and T3 treatment as assessed by two different maturation parameters: increased insulin secretion at 16.8 mM glucose and increased proinsulin-to-insulin processing. In hESCs differentiated toward β-cells, T3 enhanced MAFA expression, increased insulin content (probably mediated by the increased MAFA), and increased insulin secretion at 16.8 mM glucose. Conclusion: T3 is a useful in vitro stimulus to promote human β-cell maturation as shown in both human fetal ICCs and differentiated hESCs. The degree of maturation induced varied in the two models, possibly due to the different developmental status at the beginning of the study.

scholarly journals Increased vimentin in human α- and β-cells in type 2 diabetes

2017 ◽  
Vol 233 (3) ◽  
pp. 217-227 ◽  
Author(s):  
Maaike M Roefs ◽  
Françoise Carlotti ◽  
Katherine Jones ◽  
Hannah Wills ◽  
Alexander Hamilton ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Epithelial To Mesenchymal Transition ◽  
Islet Cells ◽  
Cell Types ◽  
Β Cells ◽  
Β Cell ◽  
Mesenchymal Transition ◽  
Cell Expression

Type 2 diabetes (T2DM) is associated with pancreatic islet dysfunction. Loss of β-cell identity has been implicated via dedifferentiation or conversion to other pancreatic endocrine cell types. How these transitions contribute to the onset and progression of T2DM in vivo is unknown. The aims of this study were to determine the degree of epithelial-to-mesenchymal transition occurring in α and β cells in vivo and to relate this to diabetes-associated (patho)physiological conditions. The proportion of islet cells expressing the mesenchymal marker vimentin was determined by immunohistochemistry and quantitative morphometry in specimens of pancreas from human donors with T2DM (n = 28) and without diabetes (ND, n = 38) and in non-human primates at different stages of the diabetic syndrome: normoglycaemic (ND, n = 4), obese, hyperinsulinaemic (HI, n = 4) and hyperglycaemic (DM, n = 8). Vimentin co-localised more frequently with glucagon (α-cells) than with insulin (β-cells) in the human ND group (1.43% total α-cells, 0.98% total β-cells, median; P < 0.05); these proportions were higher in T2DM than ND (median 4.53% α-, 2.53% β-cells; P < 0.05). Vimentin-positive β-cells were not apoptotic, had reduced expression of Nkx6.1 and Pdx1, and were not associated with islet amyloidosis or with bihormonal expression (insulin + glucagon). In non-human primates, vimentin-positive β-cell proportion was larger in the diabetic than the ND group (6.85 vs 0.50%, medians respectively, P < 0.05), but was similar in ND and HI groups. In conclusion, islet cell expression of vimentin indicates a degree of plasticity and dedifferentiation with potential loss of cellular identity in diabetes. This could contribute to α- and β-cell dysfunction in T2DM.

Harnessing immune cells to enhance β-cell mass in type 1 diabetes

2016 ◽  
Vol 64 (1) ◽  
pp. 14-20 ◽  
Author(s):  
Ercument Dirice ◽  
Rohit N Kulkarni
Keyword(s):  
Type 1 Diabetes ◽  
Mononuclear Cells ◽  
Islet Cells ◽  
Cell Mass ◽  
Cell Loss ◽  
Cell Types ◽  
Β Cells ◽  
Β Cell ◽  
Autoimmune Attack

Type 1 diabetes is characterized by early β-cell loss leading to insulin dependence in virtually all patients with the disease in order to maintain glucose homeostasis. Most studies over the past few decades have focused on limiting the autoimmune attack on the β cells. However, emerging data from patients with long-standing diabetes who continue to harbor functional insulin-producing cells in their diseased pancreas have prompted scientists to examine whether proliferation of existing β cells can be enhanced to promote better glycemic control. In support of this concept, several studies indicate that mononuclear cells that infiltrate the islets have the capacity to trigger proliferation of islet cells including β cells. These observations indicate the exciting possibility of identifying those mononuclear cell types and their soluble factors and harnessing their ability to promote β-cell growth concomitant with autoimmune therapy to prevent the onset and/or halt the progression of the disease.

scholarly journals Neuroligin-2-derived peptide-covered polyamidoamine-based (PAMAM) dendrimers enhance pancreatic β-cells' proliferation and functions

MedChemComm ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 280-293
Author(s):  
Anna Munder ◽  
Yoni Moskovitz ◽  
Aviv Meir ◽  
Shirin Kahremany ◽  
Laura Levy ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Cellular Stress ◽  
Pamam Dendrimers ◽  
Β Cells ◽  
Β Cell ◽  
Pancreatic Β Cells ◽  
Cell Functions ◽  
Functional Maturation ◽  
Glucose Stimulated Insulin Secretion

The nanoscale composite improved β-cell functions in terms of rate of proliferation, glucose-stimulated insulin secretion, resistance to cellular stress and functional maturation.

scholarly journals Promotion of β-Cell Differentiation in Pancreatic Precursor Cells by Adult Islet Cells

Endocrinology ◽  
2009 ◽  
Vol 150 (2) ◽  
pp. 570-579 ◽  
Author(s):  
Wei Chen ◽  
Salma Begum ◽  
Lynn Opare-Addo ◽  
Justin Garyu ◽  
Thomas F. Gibson ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
Glucose Transporter ◽  
Islet Cells ◽  
Precursor Cells ◽  
Cell Contact ◽  
Β Cells ◽  
Β Cell ◽  
Glucose Transporter 2 ◽  
Adult Islet

It is thought that differentiation of β-cell precursors into mature cells is largely autonomous, but under certain conditions differentiation can be modified by external factors. The factors that modify β-cell differentiation have not been identified. In this study, we tested whether adult islet cells can affect the differentiation process in mouse and human pancreatic anlage cells. We assessed β-cell proliferation and differentiation in mouse and human pancreatic anlage cells cocultured with adult islet cells or βTC3 cells using cellular, molecular, and immunohistochemical methods. Differentiation of murine anlage cells into β-cells was induced by mature islet cells. It was specific for β-cells and not a general feature of endodermal derived cells. β-Cell differentiation required cell-cell contact. The induced cells acquired features of mature β-cells including increased expression of β-cell transcription factors and surface expression of receptor for stromal cell-derived factor 1 and glucose transporter-2 (GLUT-2). They secreted insulin in response to glucose and could correct hyperglycemia in vivo when cotransplanted with vascular cells. Human pancreatic anlage cells responded in a similar manner and showed increased expression of pancreatic duodenal homeobox 1 and v-maf musculoaponeurotic fibrosarcoma oncogene homolog A and increased production of proinsulin when cocultured with adult islets. We conclude that mature β-cells can modify the differentiation of precursor cells and suggest a mechanism whereby changes in differentiation of β-cells can be affected by other β-cells. Mature β cells affect differentiation of pancreatic anlage cells into functional β cells. The differentiated cells respond to glucose and ameliorate diabetes.

scholarly journals Increased Susceptibility to Streptozotocin-Induced β-Cell Apoptosis and Delayed Autoimmune Diabetes in Alkylpurine- DNA-N-Glycosylase-Deficient Mice

2001 ◽  
Vol 21 (16) ◽  
pp. 5605-5613 ◽  
Author(s):  
John W. Cardinal ◽  
Geoffrey P. Margison ◽  
Kurt J. Mynett ◽  
Allen P. Yates ◽  
Donald P. Cameron ◽  
...  
Keyword(s):  
Islet Cells ◽  
Excision Repair ◽  
Autoimmune Diabetes ◽  
Atp Depletion ◽  
Cell Necrosis ◽  
Β Cells ◽  
Β Cell ◽  
Autoimmune Reaction ◽  
Strand Breaks

ABSTRACT Type 1 diabetes is thought to occur as a result of the loss of insulin-producing pancreatic β cells by an environmentally triggered autoimmune reaction. In rodent models of diabetes, streptozotocin (STZ), a genotoxic methylating agent that is targeted to the β cells, is used to trigger the initial cell death. High single doses of STZ cause extensive β-cell necrosis, while multiple low doses induce limited apoptosis, which elicits an autoimmune reaction that eliminates the remaining cells. We now show that in mice lacking the DNA repair enzyme alkylpurine-DNA-N-glycosylase (APNG), β-cell necrosis was markedly attenuated after a single dose of STZ. This is most probably due to the reduction in the frequency of base excision repair-induced strand breaks and the consequent activation of poly(ADP-ribose) polymerase (PARP), which results in catastrophic ATP depletion and cell necrosis. Indeed, PARP activity was not induced in APNG−/− islet cells following treatment with STZ in vitro. However, 48 h after STZ treatment, there was a peak of apoptosis in the β cells of APNG−/− mice. Apoptosis was not observed in PARP-inhibited APNG+/+ mice, suggesting that apoptotic pathways are activated in the absence of significant numbers of DNA strand breaks. Interestingly, STZ-treated APNG−/− mice succumbed to diabetes 8 months after treatment, in contrast to previous work with PARP inhibitors, where a high incidence of β-cell tumors was observed. In the multiple-low-dose model, STZ induced diabetes in both APNG−/− and APNG+/+ mice; however, the initial peak of apoptosis was 2.5-fold greater in the APNG−/− mice. We conclude that APNG substrates are diabetogenic but by different mechanisms according to the status of APNG activity.

scholarly journals Betacellulin-Induced α-Cell Proliferation Is Mediated by ErbB3 and ErbB4, and May Contribute to β-Cell Regeneration

2021 ◽  
Vol 8 ◽  
Author(s):  
Young-Sun Lee ◽  
Gyun Jee Song ◽  
Hee-Sook Jun
Keyword(s):  
Cell Proliferation ◽  
Recombinant Adenovirus ◽  
Islet Cells ◽  
Erbb Receptors ◽  
Cell Regeneration ◽  
Β Cells ◽  
Β Cell ◽  
Direct Role ◽  
Proliferative Effect ◽  
Epidermal Growth

Betacellulin (BTC), an epidermal growth factor family, is known to promote β-cell regeneration. Recently, pancreatic α-cells have been highlighted as a source of new β-cells. We investigated the effect of BTC on α-cells. Insulin+glucagon+ double stained bihormonal cell levels and pancreatic and duodenal homeobox-1 expression were increased in mice treated with recombinant adenovirus-expressing BTC (rAd-BTC) and β-cell-ablated islet cells treated with BTC. In the islets of rAd-BTC-treated mice, both BrdU+glucagon+ and BrdU+insulin+ cell levels were significantly increased, with BrdU+glucagon+ cells showing the greater increase. Treatment of αTC1-9 cells with BTC significantly increased proliferation and cyclin D2 expression. BTC induced phosphorylation of ErbB receptors in αTC1-9 cells. The proliferative effect of BTC was mediated by ErbB-3 or ErbB-4 receptor kinase. BTC increased phosphorylation of ERK1/2, AKT, and mTOR and PC1/3 expression and GLP-1 production in α-cells, but BTC-induced proliferation was not changed by the GLP-1 receptor antagonist, exendin-9. We suggest that BTC has a direct role in α-cell proliferation via interaction with ErbB-3 and ErbB-4 receptors, and these increased α-cells might be a source of new β-cells.

scholarly journals Could TDX-1 explain the changes observed in endocrine pancreas due to chronic cola drink consumption in rats? A global point of view

2020 ◽  
Author(s):  
Gabriel Cao ◽  
Julián González ◽  
Juan P. Ortiz Fragola ◽  
Angélica Muller ◽  
Mariano Tumarkin ◽  
...  
Keyword(s):  
Body Weight ◽  
Glucose Tolerance ◽  
Islet Cells ◽  
Cross Sectional Area ◽  
The Other ◽  
Cell Area ◽  
Sectional Area ◽  
Β Cells ◽  
Β Cell ◽  
Cross Sectional

AbstractIn previous studies, we reported evidence showing that chronic cola consumption in rats impairs pancreatic metabolism of insulin and glucagon and produces some alterations typically observed in the metabolic syndrome (i.e, hyperglycemia, and hypertriglyceridemia) with an increase in oxidative stress. Of note, no apoptosis nor proliferation of islet cells could be demonstrated. In the present study, 36 male Wistar rats were divided in three groups to freely drink regular cola, light cola, or water (controls). We assessed the impact of the three different beverages in glucose tolerance, lipid levels, creatinine levels and immunohistochemical changes addressed for the expression of insulin, glucagon, PDX-1 and NGN3 in islet cells, to evaluate the possible participation of PDX-1 in the changes observed in α and β cells after 6 months of treatment. On the other hand, we assessed by stereological methods, the mean volume of islets (Vi) and three important variables, the fractional β-cell area, the cross-sectional area of alpha (A α-cell) and beta cells (A β-cell), and the number of β and α cell per body weight.Cola drinking caused impaired glucose tolerance as well as fasting hyperglycemia and increase of insulin immunolabeling. Immunohistochemical expression for PDX-1 was significantly high in regular cola consumption group compared to control. In this case, we observed cytoplasmatic and nuclear localization. Likewise, a mild but significant decrease of Vi was detected after 6 months of cola drink consumption compared with control group. Also, we observed a significant decrease of fractional β cell area compared with control rats. Accordingly, a reduced mean value of islet α and β cell number per body weight compared to control was detected. Interestingly, consumption of light cola increased the Vi compared to control. In line with this, a decreased cross-sectional area of β-cells was observed after chronic consumption of both, regular and light cola, compared to controls. On the other hand, NGN3 was negative in all three groups. Our results support for the first time, the idea that TDX-1 plays a key role in the dynamics of the pancreatic islets after chronic consumption of sweetened beverages. The loss of islets cells might be attributed to autophagy, favored by the local metabolic conditions.

scholarly journals Perilipin2 down-regulation in β cells impairs insulin secretion under nutritional stress and damages mitochondria

2020 ◽  
Author(s):  
Akansha Mishra ◽  
Siming Liu ◽  
Joseph Promes ◽  
Mikako Harata ◽  
William Sivitz ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Cell Function ◽  
Islet Cells ◽  
Cell Metabolism ◽  
Nutritional Stress ◽  
Β Cells ◽  
Β Cell ◽  
Down Regulation

Perilipin 2 (PLIN2) is the lipid droplet (LD) protein in β cells that increases under nutritional stress. Down-regulation of PLIN2 is often sufficient to reduce LD accumulation. To determine whether PLIN2 positively or negatively affects β cell function under nutritional stress, PLIN2 was down-regulated in mouse β cells, INS1 cells, and human islet cells. β cell specific deletion of PLIN2 in mice on a high fat diet reduced glucose-stimulated insulin secretion (GSIS) in vivo and in vitro. Down-regulation of PLIN2 in INS1 cells blunted GSIS after 24 h incubation with 0.2 mM palmitic acids. Down-regulation of PLIN2 in human pseudoislets cultured at 5.6 mM glucose impaired both phases of GSIS, indicating that PLIN2 is critical for GSIS. Down-regulation of PLIN2 decreased specific OXPHOS proteins in all three models and reduced oxygen consumption rates in INS1 cells and mouse islets. Moreover, we found that PLIN2 deficient INS1 cells increased the distribution of a fluorescent oleic acid analog to mitochondria and showed signs of mitochondrial stress as indicated by susceptibility to fragmentation and alterations of acyl-carnitines and glucose metabolites. Collectively, PLIN2 in β cells have an important role in preserving insulin secretion, β cell metabolism and mitochondrial function under nutritional stress.

scholarly journals Discordance between GLP-1R gene and protein expression in mouse pancreatic islet cells

2020 ◽  
Vol 295 (33) ◽  
pp. 11529-11541 ◽  
Author(s):  
Sarah M. Gray ◽  
Yurong Xin ◽  
Elizabeth C. Ross ◽  
Bryanna M. Chazotte ◽  
Megan E. Capozzi ◽  
...  
Keyword(s):  
Protein Expression ◽  
Islet Cells ◽  
Expression Patterns ◽  
Metabolic Stress ◽  
Β Cells ◽  
Β Cell ◽  
Protein Levels ◽  
Gene And Protein Expression ◽  
Glucagon Like Peptide 1 ◽  
Mouse Pancreatic Islet

The insulinotropic actions of glucagon-like peptide 1 receptor (GLP-1R) in β-cells have made it a useful target to manage type 2 diabetes. Metabolic stress reduces β-cell sensitivity to GLP-1, yet the underlying mechanisms are unknown. We hypothesized that Glp1r expression is heterogeneous among β-cells and that metabolic stress decreases the number of GLP-1R–positive β-cells. Here, analyses of publicly available single-cell RNA-Seq sequencing (scRNASeq) data from mouse and human β-cells indicated that significant populations of β-cells do not express the Glp1r gene, supporting heterogeneous GLP-1R expression. To check these results, we used complementary approaches employing FACS coupled with quantitative RT-PCR, a validated GLP-1R antibody, and flow cytometry to quantify GLP-1R promoter activity, gene expression, and protein expression in mouse α-, β-, and δ-cells. Experiments with Glp1r reporter mice and a validated GLP-1R antibody indicated that >90% of the β-cells are GLP-1R positive, contradicting the findings with the scRNASeq data. α-cells did not express Glp1r mRNA and δ-cells expressed Glp1r mRNA but not protein. We also examined the expression patterns of GLP-1R in mouse models of metabolic stress. Multiparous female mice had significantly decreased β-cell Glp1r expression, but no reduction in GLP-1R protein levels or GLP-1R–mediated insulin secretion. These findings suggest caution in interpreting the results of scRNASeq for low-abundance transcripts such as the incretin receptors and indicate that GLP-1R is widely expressed in β-cells, absent in α-cells, and expressed at the mRNA, but not protein, level in δ-cells.

Sign in / Sign up

Export Citation Format

Share Document