scholarly journals The protein tyrosine phosphatase-BL, modulates pancreatic β-cell proliferation by interaction with the Wnt signalling pathway

2008 ◽  
Vol 197 (3) ◽  
pp. 543-552 ◽  
Author(s):  
Hannah J Welters ◽  
Alina Oknianska ◽  
Kai S Erdmann ◽  
Gerhart U Ryffel ◽  
Noel G Morgan
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Protein Tyrosine Phosphatase ◽  
Tyrosine Phosphatase ◽  
Wnt Signalling ◽  
Signalling Pathway ◽  
Β Cells ◽  
Β Cell ◽  
Pancreatic Β Cells ◽  
Wnt Signalling Pathway

In pancreatic β-cells, increased expression of the MODY5 gene product, HNF1β, leads to enhanced rates of apoptosis and altered regulation of the cell cycle, suggesting that control of HNF1β expression may be important for the control of β-cell proliferation and viability. It is unclear how these effects of HNF1β are mediated, but previously we have identified a protein tyrosine phosphatase, (PTP)-BL, as an HNF1β-regulated protein in β-cells and have now studied the role of this protein in INS-1 β-cells. Stably transfected cells were generated, which express either wild-type (WT) or a phosphatase-deficient mutant (PTP-BL-CS) of PTP-BL conditionally under the control of a tetracycline-regulated promoter. Enhanced expression of WT PTP-BL inhibited INS-1 cell growth dose dependently, but this effect was not observed when PTP-BL-CS was expressed. Neither construct altered the rate of apoptosis. PTP-BL has been reported to interact with components of the Wnt signalling pathway, and we observed that addition of exogenous Wnt3a resulted in an increase in cell proliferation and a rise in β-catenin levels, consistent with the operation of this pathway in INS-1 cells. Up-regulation of WT PTP-BL antagonised these responses but PTP-BL-CS failed to inhibit Wnt3a-induced proliferation. The rise in β-catenin caused by Wnt3a was also suppressed by over-expression of HNF1β, suggesting that HNF1β may interact with the Wnt signalling pathway via an increase in PTP-BL levels. We conclude that PTP-BL plays an important role in the regulation of cell cycle progression in pancreatic β-cells, and that it interacts functionally with components of the Wnt signalling pathway.

Chlorogenic acid and β-glucan from highland barley grain ameliorate β cell dysfunction via inhibiting apoptosis and improving cell proliferation

2021 ◽  
Author(s):  
Zehua Liu ◽  
Bo Li
Keyword(s):  
Cell Proliferation ◽  
Chlorogenic Acid ◽  
Barley Grain ◽  
Whole Grain ◽  
Β Cells ◽  
Β Cell ◽  
Pancreatic Β Cells ◽  
Active Compounds ◽  
Cell Dysfunction ◽  
Highland Barley

Recent studies support the view that highland barley as whole grain diet showed anti-hyperglycemic effects, while little information is available about the active compounds that could ameliorate pancreatic β cells...

scholarly journals Is resistant starch protective against colorectal cancer via modulation of the WNT signalling pathway?

2015 ◽  
Vol 74 (3) ◽  
pp. 282-291 ◽  
Author(s):  
Fiona C. Malcomson ◽  
Naomi D. Willis ◽  
John C. Mathers
Keyword(s):  
Colorectal Cancer ◽  
Cell Proliferation ◽  
Resistant Starch ◽  
Wnt Pathway ◽  
Wnt Signalling ◽  
Signalling Pathway ◽  
Wnt Signalling Pathway ◽  
Crypt Cell Proliferation ◽  
And Migration ◽  
Epigenetic Modulation

Epidemiological and experimental evidence suggests that non-digestible carbohydrates (NDC) including resistant starch are protective against colorectal cancer. These anti-neoplastic effects are presumed to result from the production of the SCFA, butyrate, by colonic fermentation, which binds to the G-protein-coupled receptor GPR43 to regulate inflammation and other cancer-related processes. The WNT pathway is central to the maintenance of homeostasis within the large bowel through regulation of processes such as cell proliferation and migration and is frequently aberrantly hyperactivated in colorectal cancers. Abnormal WNT signalling can lead to irregular crypt cell proliferation that favours a hyperproliferative state. Butyrate has been shown to modulate the WNT pathway positively, affecting functional outcomes such as apoptosis and proliferation. Butyrate's ability to regulate gene expression results from epigenetic mechanisms, including its role as a histone deacetylase inhibitor and through modulating DNA methylation and the expression of microRNA. We conclude that genetic and epigenetic modulation of the WNT signalling pathway may be an important mechanism through which butyrate from fermentation of resistant starch and other NDC exert their chemoprotective effects.

scholarly journals Trefoil Factor 2 Promotes Cell Proliferation in Pancreatic β-Cells through CXCR-4-Mediated ERK1/2 Phosphorylation

Endocrinology ◽  
2013 ◽  
Vol 154 (1) ◽  
pp. 54-64 ◽  
Author(s):  
Kazuki Orime ◽  
Jun Shirakawa ◽  
Yu Togashi ◽  
Kazuki Tajima ◽  
Hideaki Inoue ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Cell Mass ◽  
Brdu Incorporation ◽  
Trefoil Factor ◽  
Β Cells ◽  
Β Cell ◽  
Pancreatic Β Cells ◽  
Min6 Cells ◽  
Trefoil Factor 2 ◽  
Chemokine Receptor 4

Decreased β-cell mass is a hallmark of type 2 diabetes, and therapeutic approaches to increase the pancreatic β-cell mass have been expected. In recent years, gastrointestinal incretin peptides have been shown to exert a cell-proliferative effect in pancreatic β-cells. Trefoil factor 2 (TFF2), which is predominantly expressed in the surface epithelium of the stomach, plays a role in antiapoptosis, migration, and proliferation. The TFF family is expressed in pancreatic β-cells, whereas the role of TFF2 in pancreatic β-cells has been obscure. In this study, we investigated the mechanism by which TFF2 enhances pancreatic β-cell proliferation. The effects of TFF2 on cell proliferation were evaluated in INS-1 cells, MIN6 cells, and mouse islets using an adenovirus vector containing TFF2 or a recombinant TFF2 peptide. The forced expression of TFF2 led to an increase in bromodeoxyuridine (BrdU) incorporation in both INS-1 cells and islets, without any alteration in insulin secretion. TFF2 significantly increased the mRNA expression of cyclin A2, D1, D2, D3, and E1 in islets. TFF2 peptide increased ERK1/2 phosphorylation and BrdU incorporation in MIN6 cells. A MAPK kinase inhibitor (U0126) abrogated the TFF2 peptide-mediated proliferation of MIN6 cells. A CX-chemokine receptor-4 antagonist also prevented the TFF2 peptide-mediated increase in ERK1/2 phosphorylation and BrdU incorporation in MIN6 cells. These results indicated that TFF2 is involved in β-cell proliferation at least partially via CX-chemokine receptor-4-mediated ERK1/2 phosphorylation, suggesting TFF2 may be a novel target for inducing β-cell proliferation.

scholarly journals Three-dimensional analysis of β-cell proliferation by a novel mouse model

2019 ◽  
Author(s):  
Shinsuke Tokumoto ◽  
Daisuke Yabe ◽  
Hisato Tatsuoka ◽  
Ryota Usui ◽  
Muhammad Fauzi ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Cell Cycle Progression ◽  
Three Dimensional ◽  
Spatiotemporal Analysis ◽  
Mouse Line ◽  
Β Cells ◽  
Β Cell ◽  
Insulin Promoter ◽  
Novel Method

SummaryInducing β-cell proliferation could inhibit diabetes progression. Many factors have been suggested as potential β-cell mitogens, but their impact on β-cell replication has not been confirmed due to the lack of a standardized β-cell proliferation assay. In this study, we developed a novel method that specifically labels replicating β cells and yields more reproducible results than current immunohistochemical assays. We established a mouse line expressing the fluorescent ubiquitination-based cell cycle indicator (Fucci2a) reporter only in β cells through Cre-mediated recombination under the control of the rat insulin promoter (RIP-Cre;Fucci2aR). Three-dimensional imaging of optically cleared pancreas tissue from these mice enabled the quantification of replicating β cells in islets and morphometric analysis of islets following mitogen treatment. Intravital imaging of RIP-Cre;Fucci2aR mice revealed cell cycle progression of β cells. Thus, this novel mouse line is a powerful tool for spatiotemporal analysis of β-cell proliferation in response to mitogen stimulation.

scholarly journals Nuclear Factor Y in Male Mouse pancreatic β-cells Plays a Crucial Role in Glucose Homeostasis by Regulating β-Cell Mass and Insulin Secretion

2021 ◽  
Author(s):  
Yin Liu ◽  
Siyuan He ◽  
Ruixue Zhou ◽  
Xueping Zhang ◽  
Shanshan Yang ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Insulin Secretion ◽  
Cell Mass ◽  
Physiological Role ◽  
Nuclear Factor ◽  
Β Cells ◽  
Β Cell ◽  
Pancreatic Β Cells ◽  
Nuclear Factor Y

Pancreatic β-cell mass and insulin secretion are determined by the dynamic change of transcription factor expression levels in response to altered metabolic demand. Nuclear factor-Y (NF-Y) is an evolutionarily conserved transcription factor playing critical roles in multiple cellular processes. However, the physiological role of NF-Y in pancreatic β-cells is poorly understood. The present study was undertaken in a conditional knockout of <i>Nf-ya</i> specifically in pancreatic β-cells (<i>Nf-ya </i>βKO) to define the essential physiological role of NF-Y in β-cells. <i>Nf-ya </i>βKO mice exhibited glucose intolerance without changes in insulin sensitivity. Reduced β-cell proliferation resulting in decreased β-cell mass was observed in these mice, which was associated with disturbed actin cytoskeleton. NF-Y-deficient β-cells also exhibited impaired insulin secretion with a reduced Ca<sup>2+</sup> influx in response to glucose, which was associated an inefficient glucose uptake into β-cells due to a decreased expression of glucose transporter 2 and a reduction in ATP production resulting from the disruption of mitochondrial integrity. This study is the first to show that NF-Y is critical for pancreatic islets homeostasis and function through regulation in β-cell proliferation, glucose uptake into β-cells, and mitochondrial energy metabolism. Modulating NF-Y expression in β-cells may therefore offer an attractive approach for therapeutic intervention.

scholarly journals Effects of metformin on compensatory pancreatic β-cell hyperplasia in mice fed a high-fat diet

2017 ◽  
Vol 313 (3) ◽  
pp. E367-E380 ◽  
Author(s):  
Kazuki Tajima ◽  
Jun Shirakawa ◽  
Tomoko Okuyama ◽  
Mayu Kyohara ◽  
Shunsuke Yamazaki ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Cell Proliferation ◽  
High Fat Diet ◽  
Cell Mass ◽  
Mammalian Target Of Rapamycin ◽  
High Fat ◽  
Β Cells ◽  
Β Cell ◽  
Pancreatic Β Cells ◽  
Cell Hyperplasia

Metformin has been widely used for the treatment of type 2 diabetes. However, the effect of metformin on pancreatic β-cells remains controversial. In this study, we investigated the impacts of treatment with metformin on pancreatic β-cells in a mouse model fed a high-fat diet (HFD), which triggers adaptive β-cell replication. An 8-wk treatment with metformin improved insulin resistance and suppressed the compensatory β-cell hyperplasia induced by HFD-feeding. In contrast, the increment in β-cell mass arising from 60 wk of HFD feeding was similar in mice treated with and those treated without metformin. Interestingly, metformin suppressed β-cell proliferation induced by 1 wk of HFD feeding without any changes in insulin resistance. Metformin directly suppressed glucose-induced β-cell proliferation in islets and INS-1 cells in accordance with a reduction in mammalian target of rapamycin phosphorylation. Taken together, metformin suppressed HFD-induced β-cell proliferation independent of the improvement of insulin resistance, partly via direct actions.

scholarly journals Sfrp5 mediates glucose-induced proliferation in rat pancreatic β-cells

2016 ◽  
Vol 229 (2) ◽  
pp. 73-83 ◽  
Author(s):  
Binbin Guan ◽  
Wenyi Li ◽  
Fengying Li ◽  
Yun Xie ◽  
Qicheng Ni ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Wnt Signaling ◽  
Molecular Mechanisms ◽  
Wnt Signaling Pathway ◽  
Akt Pathway ◽  
Pancreatic Β Cell ◽  
Β Cells ◽  
Β Cell ◽  
Pancreatic Β Cells ◽  
Promote Cell Proliferation

The cellular and molecular mechanisms of glucose-stimulated β-cell proliferation are poorly understood. Recently, secreted frizzled-related protein 5 (encoded by Sfrp5; a Wnt signaling inhibitor) has been demonstrated to be involved in β-cell proliferation in obesity. A previous study demonstrated that glucose enhanced Wnt signaling to promote cell proliferation. We hypothesized that inhibition of SFRP5 contributes to glucose-stimulated β-cell proliferation. In this study, we found that the Sfrp5 level was significantly reduced in high glucose-treated INS-1 cells, primary rat β-cells, and islets isolated from glucose-infused rats. Overexpression of SFRP5 diminished glucose-stimulated proliferation in both INS-1 cells and primary β-cells, with a concomitant inhibition of the Wnt signaling pathway and decreased cyclin D2 expression. In addition, we showed that glucose-induced Sfrp5 suppression was modulated by the PI3K/AKT pathway. Therefore, we conclude that glucose inhibits Sfrp5 expression via the PI3K/AKT pathway and hence promotes rat pancreatic β-cell proliferation.

scholarly journals cMyc Is a Principal Upstream Driver of β-Cell Proliferation in Rat Insulinoma Cell Lines and Is an Effective Mediator of Human β-Cell Replication

2011 ◽  
Vol 25 (10) ◽  
pp. 1760-1772 ◽  
Author(s):  
Esra Karslioglu ◽  
Jeffrey W. Kleinberger ◽  
Fatimah G. Salim ◽  
Amy E. Cox ◽  
Karen K. Takane ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Cell Death ◽  
Cell Lines ◽  
Cell Cycle Control ◽  
Diabetes Research ◽  
Cell Replication ◽  
Β Cells ◽  
Β Cell ◽  
Normal Rat

Adult human β-cells replicate slowly. Also, despite the abundance of rodent β-cell lines, there are no human β-cell lines for diabetes research or therapy. Prior studies in four commonly studied rodent β-cell lines revealed that all four lines displayed an unusual, but strongly reproducible, cell cycle signature: an increase in seven G1/S molecules, i.e. cyclins A, D3, and E, and cdk1, -2, -4, and -6. Here, we explore the upstream mechanism(s) that drive these cell cycle changes. Using biochemical, pharmacological and molecular approaches, we surveyed potential upstream mitogenic signaling pathways in Ins 1 and RIN cells. We used both underexpression and overexpression to assess effects on rat and human β-cell proliferation, survival and cell cycle control. Our results indicate that cMyc is: 1) uniquely up-regulated among other candidates; 2) principally responsible for the increase in the seven G1/S molecules; and, 3) largely responsible for proliferation in rat β-cell lines. Importantly, cMyc expression in β-cell lines, although some 5- to 7-fold higher than normal rat β-cells, is far below the levels (75- to 150-fold) previously associated with β-cell death and dedifferentiation. Notably, modest overexpression of cMyc is able to drive proliferation without cell death in normal rat and human β-cells. We conclude that cMyc is an important driver of replication in the two most commonly employed rat β-cell lines. These studies reverse the current paradigm in which cMyc overexpression is inevitably associated with β-cell death and dedifferentiation. The cMyc pathway provides potential approaches, targets, and tools for driving and sustaining human β-cell replication.

scholarly journals TCTP Is Essential for β-Cell Proliferation and Mass Expansion During Development and β-Cell Adaptation in Response to Insulin Resistance

Endocrinology ◽  
2014 ◽  
Vol 155 (2) ◽  
pp. 392-404 ◽  
Author(s):  
Ming-Jen Tsai ◽  
Hsin-Fang Yang-Yen ◽  
Ming-Ko Chiang ◽  
Mei-Jen Wang ◽  
Shiou-Shian Wu ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Cell Proliferation ◽  
Cell Mass ◽  
Perinatal Period ◽  
Β Cells ◽  
Β Cell ◽  
Pancreatic Β Cells ◽  
Cell Adaptation ◽  
Insulin Resistant ◽  
Mass Expansion

The perinatal period is critical for β-cell mass establishment, which is characterized by a transient burst in proliferation to increase β-cell mass in response to the need for glucose homeostasis throughout life. In adulthood, the ability of β-cells to grow, proliferate, and expand their mass is also characteristic of pathological states of insulin resistance. Translationally controlled tumor-associated protein (TCTP), an evolutionarily highly conserved protein that is implicated in cell growth and proliferation, has been identified as a novel glucose-regulated survival-supporting protein in pancreatic β-cells. In this study, the enhanced β-cell proliferation detected both during the perinatal developmental period and in insulin-resistant states in high-fat diet-fed mice was found to parallel the expression of TCTP in pancreatic β-cells. Specific knockout of TCTP in β-cells led to increased expression of total and nuclear Forkhead box protein O1 and tumor suppressor protein 53, and decreased expression of p70S6 kinase phosphorylation and cyclin D2 and cyclin-dependent kinase 2. This resulted in decreased β-cell proliferation and growth, reduced β-cell mass, and insulin secretion. Together, these effects led to hyperglycemia. These observations suggest that TCTP is essential for β-cell mass expansion during development and β-cell adaptation in response to insulin resistance.

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