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Mukhi Sandeep S Department of Embryology, Carnegie Institution, 3520 San Martin Drive, Baltimore, MD 21218, - - 2009
Insulin-producing beta-cells are present as single cells or in small clusters distributed throughout the pancreas of the Xenopus laevis tadpole. During metamorphic climax when the exocrine pancreas dedifferentiates to progenitor cells, the beta-cells undergo two changes. Insulin mRNA is down regulated at the beginning of metamorphic climax (NF62) and reexpressed ...
Bernardo Andreia S - - 2009
Embryonic stem (ES) cells represent a possible source of islet tissue for the treatment of diabetes. Achieving this goal will require a detailed understanding of how the transcription factor cascade initiated by the homeodomain transcription factor Pdx1 culminates in pancreatic beta-cell development. Here we describe a genetic approach that enables ...
Baeyens Luc - - 2009
BACKGROUND & AIMS: Exocrine acinar cells in the pancreas are highly differentiated cells that retain a remarkable degree of plasticity. After isolation and an initial phase of dedifferentiation in vitro, rodent acinar cells can convert to endocrine beta-cells when cultured in the presence of appropriate factors. The mechanisms regulating this ...
Nagaya Masaki - - 2009
Transdifferentiation of cells from a patient's own liver into pancreatic beta-cells could be useful for beta-cell replacement. We hypothesized that intrahepatic biliary epithelial cells (IHBECs) could become a new source of insulin-producing cells. IHBECs isolated from adult mice were expanded using our novel culture method termed, collagen-embedded floating culture method ...
Wang Weidong - - 2009
To identify small molecules that can induce beta-cell replication, a large chemical library was screened for proliferation of growth-arrested, reversibly immortalized mouse beta cells by using an automated high-throughput screening platform. A number of structurally diverse, active compounds were identified, including phorbol esters, which likely act through protein kinase C, ...
Rafacho Alex - - 2009
Activation of insulin signaling and cell cycle intermediates is required for adult beta-cell proliferation. Here, we report a model to study beta-cell proliferation in living rats by administering three different doses of dexamethasone (0.1, 0.5, and 1.0 mg/kg ip, DEX 0.1, DEX 0.5, and DEX 1.0, respectively) for 5 days. ...
Maes Emmanuel - - 2009
The yeast Candida albicans is an opportunistic pathogen that causes infections in immunocompromised individuals with a high morbidity and mortality levels. Recognition of yeasts by host cells is directly mediated by cell wall components of the yeast, including a wide range of abundantly expressed glycoconjugates. Of particular interest in C. ...
Green J Angelo - - 2009
The integrin beta(1) cytoplasmic domain (tail) serves as a scaffold for numerous intracellular proteins. The mechanisms by which the tail coordinates these proteins to facilitate extracellular matrix assembly and cell spreading are not clear. This study demonstrates that the beta(1) cytoplasmic domain can regulate cell spreading on fibronectin and fibronectin ...
Balcazar Norman N Washington University School of Medicine, Division of Endocrinology, Metabolism & Lipid Research, St. Louis, Missouri, 63110, - - 2009
Growth factors, insulin signaling, and nutrients are important regulators of beta-cell mass and function. The events linking these signals to the regulation of beta-cell mass are not completely understood. The mTOR pathway integrates signals from growth factors and nutrients. Here, we evaluated the role of the mTOR/raptor (mTORC1) signaling in ...
Yang Pu - - 2009
AIMS: Clear differences of biological function between very low density lipoprotein receptor (VLDLR) types I and II have not been defined. The purpose of this study is to characterize VLDLR activities during cell proliferation and migration using adenocarcinoma SGC7901 cells. MAIN METHODS: Western blotting was used to test protein expression. ...
Johnson James D - - 2009
Type 2 diabetes occurs when the endocrine pancreas can no longer secrete enough insulin to maintain glucose and lipid homeostasis. This is likely due to cumulative defects in beta-cell fate and function, as well as insulin resistance. A number of recent studies, including ones from our group, have used unbiased ...
Yang Xiao-Di - - 2009
Biopolyesters of polyhydroxyalkanoates (PHAs), including poly-3-hydroxybutyrate (PHB), co-polyester of 3-hydroxybutyrate and 4-hydroxybutyrate (P3HB4HB), and co-polyester of 3-hydroxybutyrate and 3-hydroxyhexanoate (PHBHHx) have been well investigated for their biocompatibility. For in vivo application, it is very important that the degradation products of PHAs, especially the oligomers, are not harmful to the cells ...
Guerra Mar??a Montserrat - - 2009
Increasing evidence suggests that the hypophyseal pars tuberalis (PT) plays a key role in the transduction of light/dark (melatonin) information to the endocrine system. It has been shown that PT-specific cells express melatonin receptors and thyrotropin hormone (TSH) subunits. However, these cells do not resemble thyrotrophs or any other of ...
Boo Jung H - - 2009
Presenilin (PS) is involved in many cellular events under physiological and pathological conditions. Previous reports have revealed that PS deficiency results in hyperproliferation and resistance to apoptotic cell death. In the present study, we investigated the effects of PS on beta-catenin and cell mortality during serum deprivation. Under these conditions, ...
Lin Peng - - 2009
Diabetes mellitus is a metabolic disorder characterized by elevated blood sugar and progressive failure of insulin-producing beta-cells. Persistent hyperglycemia and blood sugar fluctuation are two general phenomena in diabetic patients, and both of them can result in an increased frequency of beta-cell apoptosis. Therefore, rescuing pancreatic beta-cells from glucotoxicity-induced beta-cell ...
Pajak Beata - - 2009
Herein we demonstrate that PC12 cells overexpress human amyloid beta precursor protein bearing double Swedish mutation(AbetaPPsw), showing the phenotype characteristic for Alzheimer's disease (AD). Examination of cells at ultrastructural level revealed the intracellular presence of peptide aggregates. Furthermore, autophagy induction was found to be a hallmark of amyloid beta-induced cytotoxicity. ...
Song Woo-Jin - - 2009
The two main forms of human diabetes mellitus (DM) are characterized by an absolute (type 1) and a relative (type 2) reduction in functional insulin-producing beta cell mass in the pancreas. Type 1 DM results from autoimmune assault of beta cells, and type 2 from the failure of pancreatic beta ...
Feng Daorong - - 2009
BACKGROUND: A deficiency in Perk (EIF2AK3) causes multiple neonatal defects in humans known as the Wolcott Rallison syndrome. Perk KO mice exhibit the same array of defects including permanent neonatal diabetes (PND). PND in mice was previously shown by us to be due to a decrease in beta cell proliferation ...
Marselli Lorella - - 2009
Human beta-cell gene profiling is a powerful tool for understanding beta-cell biology in normal and pathological conditions. The assessment is complicated when isolated islets are studied because of contamination by non-beta-cells and the exposure to the trauma of isolation that causes changes in gene expression. These limitations can be overcome ...
Helleboid-Chapman Audrey - - 2009
Apolipoprotein A-V is an important determinant of plasma triglyceride level in both humans and mice. This study showed the physiological impact of apoA-V on insulin secretion in rat pancreatic beta-cells (INS-1 cells). In order to precise the mechanism of action, binding experiments coupled to mass spectrometry were performed to identify ...
Poon Raymond - - 2009
BACKGROUND: beta-catenin and transforming growth factor beta signaling are activated in fibroblasts during wound healing. Both signaling pathways positively regulate fibroblast proliferation during this reparative process, and the effect of transforming growth factor beta is partially mediated by beta-catenin. Other cellular processes, such as cell motility and the induction of ...
Yeh Yi-Chun - - 2009
Upregulation and overexpression of discoidin domain receptor 1 (DDR1) have been implied in the regulation of kidney development and progression of cancers. Our previous studies with Mardin-Darby canine kidney (MDCK) cells showed that overexpression of DDR1 inhibited cell spreading, whereas dominant negative DDR1 promoted cell spreading on collagen-coated dish. Cell ...
Karaca Melis - - 2009
BACKGROUND: The mass of pancreatic beta-cells varies according to increases in insulin demand. It is hypothesized that functionally heterogeneous beta-cell subpopulations take part in this process. Here we characterized two functionally distinct groups of beta-cells and investigated their physiological relevance in increased insulin demand conditions in rats. METHODS: Two rat ...
Best Leonard - - 2009
BACKGROUND/AIMS: Pancreatic beta-cell function is influenced by changes in cell volume. Such volume changes depend on water permeability of the plasma membrane, conferred in part by aquaporins. Islet cells express aquaporin 7 (AQP7), which is permeable to urea and glycerol in addition to water. We therefore investigated the effects of ...
Du Yi-Chieh Nancy - - 2009
It is unclear whether the cellular origin of various forms of pancreatic cancer involves transformation or transdifferentiation of different target cells or whether tumors arise from common precursors, with tumor types determined by the specific genetic alterations. Previous studies suggested that pancreatic ductal carcinomas might be induced by polyoma middle ...
Montanya Eduard - - 2009
The endocrine pancreas has a significant remodeling capacity that plays a crucial role in the maintenance of glucose homeostasis. Changes in beta-cell apoptosis, replication and size, and islet neogenesis contribute to the remodeling of the endocrine pancreas. The extent of their respective contribution varies significantly depending on the specific condition ...
Dubey Ashok K - - 2009
Amyloid-beta(Abeta42), which is known to be toxic to neuronal cells, protects yeast cells from severe sodium hydroxide toxicity. More than 85% cell death was caused by treatment with 1 mM NaOH and approximately 95% was observed at a 2 mM concentration. However, greater than 55% cells survived the treatment in ...
Russ Holger A - - 2009
BACKGROUND: In-vitro expansion of functional beta cells from adult human islets is an attractive approach for generating an abundant source of cells for beta-cell replacement therapy of diabetes. Using genetic cell-lineage tracing we have recently shown that beta cells cultured from adult human islets undergo rapid dedifferentiation and proliferate for ...
Hellemans Karine H - - 2009
Chronically elevated levels of fatty acids-FA can cause beta cell death in vitro. Beta cells vary in their individual susceptibility to FA-toxicity. Rat beta cells were previously shown to better resist FA-toxicity in conditions that increased triglyceride formation or mitochondrial and peroxisomal FA-oxidation, possibly reducing cytoplasmic levels of toxic FA-moieties. ...
Schulthess Fabienne T - - 2009
Apoptosis is a hallmark of beta-cell death in both type 1 and type 2 diabetes mellitus. Understanding how apoptosis contributes to beta-cell turnover may lead to strategies to prevent progression of diabetes. A key mediator of apoptosis, mitochondrial function, and cell survival is apoptosis inducing factor (AIF). In the present ...
Cvjetićanin Tamara - - 2009
Diabetes is characterized by progressive failure of insulin producing beta cells. It is well known that both saturated fatty acids and various products of immune cells can contribute to the reduction of beta cell viability and functionality during diabetes pathogenesis. However, their joint action on beta cells has not been ...
Bachar Etti - - 2009
Palmitate is a potent inducer of endoplasmic reticulum (ER) stress in beta-cells. In type 2 diabetes, glucose amplifies fatty-acid toxicity for pancreatic beta-cells, leading to beta-cell dysfunction and death. Why glucose exacerbates beta-cell lipotoxicity is largely unknown. Glucose stimulates mTORC1, an important nutrient sensor involved in the regulation of cellular ...
Sun Yanhong - - 2009
Beta-elemene monosubstituted amine, ether and rhenium coordinated complex were synthesized. Their structures were characterized by IR, (1)H NMR, (13)C NMR, HRMS or EA. Their IC(50) on HeLa cell lines, cell cycle and protein expression of G(1) phase (Cyclin D(1), Rb, P-Rb) were detected respectively by the method of WST-1, Flow ...
Palozza Paola - - 2009
Lycopene beta-cyclase (tlcy-b) tomatoes, obtained by modulating carotenogenesis via genetic engineering, contain a large amount of beta-carotene, as clearly visible by their intense orange colour. In the present study we have subjected tlcy-b tomatoes to an in vitro simulated digestion and analysed the effects of digestate on cell proliferation. To ...
Szabat Marta - - 2009
The enigmatic process of beta-cell maturation has significant implications for diabetes pathogenesis, and potential diabetes therapies. This study examined the dynamics and heterogeneity of insulin and pancreatic duodenal homeobox (Pdx)-1 gene expression in adult beta-cells. Insulin and Pdx1 expression were monitored in human and mouse islet cells and MIN6 cells ...
Kwon Chulan C Gladstone Institute of Cardiovascular Disease, San Francisco, San Francisco, California 94158, USA. - - 2008
Despite decades of progress in cardiovascular biology, heart disease remains the leading cause of death in the developed world. Recently, cell-based therapy has emerged as a promising avenue for future therapeutics. However, the molecular signals that regulate cardiac progenitor cells are not well-understood. Wnt/beta-catenin signaling is essential for expansion and ...
Liu Hui H Department of Pathology and Immunology, Washington University, St. Louis, Missouri, - - 2009
Our previous studies demonstrated that nutrient regulation of mammalian target of rapamycin (mTOR) signaling promotes regenerative processes in rodent islets but rarely in human islets. Our objective was to extend these findings by using therapeutic agents to determine whether the regulation of glycogen synthase kinase-3 (GSK-3)/beta-catenin and mTOR signaling represent ...
Ariyama Yasuyo - - 2008
Low expression of antioxidant enzymes makes pancreatic beta-cells susceptible to cell damage by oxidative stress. Pancreatic beta-cell loss caused by endoplasmic reticulum stress is associated with the onset of diabetes mellitus. The present studies were undertaken to investigate a possible involvement of proapoptotic gene CHOP in pancreatic beta-cells damage by ...
Prunotto Marco - - 2009
We examined the in vitro effects of imatinib (Novartis Pharma AG, Basel, Switzerland) as a possible inhibitor of PDGFR pathway on cells derived from a recurrence of a pleural malignant solitary fibrous tumor (SFT). Primary cell culture was characterised by immunofluorescence. SFT-derived cells were treated with imatinib at different time ...
Puri Sapna - - 2009
The Vhlh gene codes for the von Hippel-Lindau protein (VHL), a tumor suppressor that is a key player in the cellular response to oxygen sensing. In humans, a germline mutation in the VHL gene leads to the von Hippel-Lindau disease, a familial syndrome characterized by benign and malignant tumors of ...
Chen R-S - - 2009
xCT, the functional subunit of the cystine/glutamate transporter xc- system, plays a critical role in the maintenance of intracellular glutathione and redox balance. Disruption of xCT significantly inhibits the growth of a variety of carcinomas, including lymphoma, glioma, prostate and breast cancer. However, the role of xCT in tumor metastasis ...
Reers Christina - - 2009
The prevalence of type 2 diabetes mellitus escalates with aging although beta-cell mass, a primary parameter of beta-cell function, is subject to compensatory regulation. So far it is unclear whether the proliferative capacity of pancreatic islets is restricted by senescence. Human pancreatic tissue from n=20 non-diabetic organ donors with a ...
Campbell-Thompson M - - 2009
AIMS/HYPOTHESIS: Recent histological analysis of pancreases obtained from patients with long-standing type 1 diabetes identified chronic islet inflammation and limited evidence suggestive of beta cell replication. Studies in rodent models also suggest that beta cell replication can be induced by certain inflammatory cytokines and by gastrin. We therefore tested the ...
Scharfmann R - - 2008
Understanding in detail how pancreatic endocrine cells develop is important for many reasons. From a scientific point of view, elucidation of such a complex process is a major challenge. From a more applied point of view, this may help us to better understand and treat specific forms of diabetes. Although ...
Halban P A - - 2008
The functional mass of beta-cells is decreased in type 2 diabetes. Replacing missing beta-cells or triggering their regeneration may thus allow for improved treatment of type 2 diabetes, to the extent that this is combined with therapy for improved insulin sensitivity. Although progress has been made in deriving beta-cell-like cells ...
Dowling Paul - - 2008
Media conditioned by dysfunctioning pancreatic beta cells offer an excellent source of potential protein markers associated with this phenotype. Proteins identified from cell culture model systems are often found to be of importance clinically. Previous work by us and others have shown that low-passage MIN-6 cells (MIN-6(L)) respond to changes ...
Kahn S E - - 2008
A characteristic and dominant feature of type 2 diabetes is a reduction in beta-cell function that is associated with a decrease in beta-cell volume. A decline in the first-phase insulin response following intravenous glucose administration can be demonstrated as the fasting glucose concentration increases. This response is completely absent before ...
Pipeleers D - - 2008
Type 1 and type 2 diabetes have often been presented as disease forms that profoundly differ in the presence and pathogenic significance of a reduced beta-cell mass. We review evidence indicating that the beta-cell mass in type 1 diabetes is usually not decreased by at least 90% at clinical onset, ...
Smolarz H D - - 2008
The chemical and pharmaceutical studies carried out on species from Polygonum L. genus showed biological activity both of the extracts and the components isolated from them. These results were the impulse to examine Polygonum amphibium L. The aim of this study was the isolation of active components from methanol extract ...
Akirav Eitan - - 2008
Beta-cell regeneration is a fundamental but elusive goal for type 1 diabetes research. Our objective is to review newer human and animal studies of beta-cell destruction and regeneration and consider the implications for treatment of type 1 diabetes. Recent human and animal studies of beta-cell destruction and regeneration in type ...
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