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Akpinar Pinar - - 2005
The signals and molecular mechanisms that regulate the replication of terminally differentiated beta cells are unknown. Here, we report the identification and characterization of transmembrane protein 27 (Tmem27, collectrin) in pancreatic beta cells. Expression of Tmem27 is reduced in Tcf1(-/-) mice and is increased in islets of mouse models with ...
Donath Marc Y - - 2005
A decrease in the number of functional insulin-producing beta-cells contributes to the pathophysiology of type 2 diabetes. Opinions diverge regarding the relative contribution of a decrease in beta-cell mass versus an intrinsic defect in the secretory machinery. Here we review the evidence that glucose, dyslipidemia, cytokines, leptin, autoimmunity, and some ...
Bogdani Marika - - 2005
The development of islet cell transplantation as a cure for diabetes is limited by the shortage of human donor organs. Moreover, currently used grafts exhibit a marginal beta-cell mass with an apparently low capacity for beta-cell renewal and growth. Although duct-associated nonendocrine cells have often been suggested as a potential ...
Ben-Yehudah Ahmi - - 2005
Noninvasive detection of differentiated cells is increasingly demanded for accurate and reliable assessments of both in vitro and in vivo experimental systems. Here we present an efficient, innovative approach for imaging the beta cells of the pancreatic islets of Langerhans. The main physiologic function of beta cells is glucose-stimulated insulin ...
Sun Ping - - 2006
Both malignant and normal prostate epithelial cells produce endothelin-1 (ET-1), a critical factor in prostate cancer (CaP) progression. beta-Catenin (beta-cat), a key component of the Wnt signaling pathway, is also implicated in CaP progression via beta-cat/T cell factor (Tcf) signaling. We recently demonstrated that beta-cat/Tcf-4 regulates transcription of ET-1 in ...
Bao Shunzhong S Medicine Department Mass Spectrometry Facility and Division of Endocrinology, Metabolism, and Lipid Research, Washington University School of Medicine, St. Louis, Missouri 63110, - - 2006
Studies involving pharmacologic inhibition or transient reduction of Group VIA phospholipase A2 (iPLA2beta) expression have suggested that it is a housekeeping enzyme that regulates cell 2-lysophosphatidylcholine (LPC) levels, rates of arachidonate incorporation into phospholipids, and degradation of excess phosphatidylcholine (PC). In insulin-secreting islet beta-cells and some other cells, in contrast, ...
Andrali Sreenath S - - 2005
Several nuclear and cytoplasmic proteins in metazoans are modified by O-linked N-acetylglucosamine (O-GlcNAc). This modification is dynamic and reversible similar to phosphorylation and is catalyzed by the O-linked GlcNAc transferase (OGT). Hyperglycemia has been shown to increase O-GlcNAc levels in pancreatic beta cells, which appears to interfere with beta-cell function. ...
Kurth Thomas - - 2005
During development cell proliferation and morphogenetic movements are tightly intermingled. Both processes depend on the same cytoskeletal elements. Therefore, precise regulation of local mitotic activity seems to be basic for proper embryogenesis. Here, I report on bottle cells as an early non-mitotic cell population in the Xenopus gastrula. Endogenous and ...
Portha Bernard - - 2005
Now that the reduction in beta-mass has been clearly established in humans with type 2 diabetes mellitus (T2DM) 1-4, the debate focuses on the possible mechanisms responsible for decreased beta-cell number and impaired beta-cell function and their multifactorial etiology. Appropriate inbred rodent models are essential tools for identification of genes ...
Masiello Pellegrino - - 2006
Type 2 diabetes is increasingly viewed as a disease of insulin deficiency due not only to intrinsic pancreatic beta-cell dysfunction but also to reduction of beta-cell mass. It is likely that, in diabetes-prone subjects, the regulated beta-cell turnover that adapts cell mass to body's insulin requirements is impaired, presumably on ...
Gustavsson Natalia - - 2005
OBJECTIVE: We recently showed that timing and magnitude of the glucose-induced cytoplasmic calcium [Ca2+]i response are reproducible and specific for the individual beta cell. We now wanted to identify which step(s) of stimulus-secretion coupling determine the cell specificity of the [Ca2+]i response and whether cell specificity is lost in beta-cells ...
Bouwens Luc - - 2005
Beta-cell mass regulation represents a critical issue for understanding diabetes, a disease characterized by a near-absolute (type 1) or relative (type 2) deficiency in the number of pancreatic beta cells. The number of islet beta cells present at birth is mainly generated by the proliferation and differentiation of pancreatic progenitor ...
Homaeigohar S Sh - - 2005
Beta-tricalcium phosphate-reinforced high-density polyethylene (beta-TCP/HDPE) is a new biomaterial which was made as a copy of bone composition with the aim of replacement of bony tissues. The composite samples were prepared using medical grade TCP powder and granular polyethylene. The raw materials were first compounded and the resulting composite preforms ...
Poltoratsky Vladimir - - 2005
The DNA polymerase beta (Pol beta) null background renders mouse embryonic fibroblast (MEF) cells base excision repair deficient and hyper-mutagenic upon treatment with the monofunctional alkylating agent, methyl methanesulfonate (MMS). This effect involves an increase in all types of base substitutions, with a modest predominance of G to A transitions. ...
Murtaugh L Charles - - 2005
Despite our increasingly sophisticated understanding of transcriptional regulation in pancreas development, we know relatively little about the extrinsic signaling pathways involved in this process. We show here that the early pancreatic epithelium exhibits a specific enrichment in unphosphorylated beta-catenin protein, a hallmark of activation of the canonical Wnt signaling pathway. ...
Takahashi Rui - - 2006
Abnormal glucagon secretion is often associated with diabetes mellitus. However, the mechanisms by which nutrients modulate glucagon secretion remain poorly understood. Paracrine modulation by beta- or delta-cells is among the postulated mechanisms. Herein we present further evidence of the paracrine mechanism. First, to activate cellular metabolism and thus hormone secretion ...
Dessimoz Jessica - - 2005
Mutations and deregulation of adenomatous polyposis coli (APC) and beta-catenin are implicated in specific cancers of the pancreas, but the role of Wnt pathway in normal pancreas development and homeostasis is unknown. This article reports a comprehensive investigation of the activity and the role of the Wnt pathway in pancreas ...
Chang Kyung Hwa - - 2005
Beta-Secretase (betaSEC) was expressed in Trichoplusia ni BTI Tn5B1-4 (Tn5B1-4) cells transformed with cDNAs encoding beta1,4-galactosyltransferase (GalT) and Gal beta1,4-GlcNAc alpha 2,6-sialyltransferase (ST). The apparent molecular weight of recombinant beta-secretase was increased from 57 to 59 k Da. A lectin blot analysis indicated that recombinant beta-secretase from Tn5B1-4 betaSEC/GalT-ST cells ...
Eder-Czembirek Christina - - 2005
Betulinic acid (BetA), a new experimental cytotoxic compound that is active against human melanoma cells and neuroectodermal tumor cells, has recently been shown to be also effective against head and neck squamous carcinoma cells (HNSCC). In this study we investigated BetA in combination with cisplatin in squamous cell carcinoma cell ...
Teta Monica - - 2005
Although many signaling pathways have been shown to promote beta-cell growth, surprisingly little is known about the normal life cycle of preexisting beta-cells or the signaling pathways required for beta-cell survival. Adult beta-cells have been speculated to have a finite life span, with ongoing adult beta-cell replication throughout life to ...
Skak Kresten - - 2005
Type 1 diabetes (T1D) is an autoimmune disease in which the pancreatic beta-cells are destroyed in an immune-mediated process. In one mouse model of T1D, the co-expression of the costimulatory molecule, B7-1, and the pro-inflammatory cytokine, tumor necrosis factor (TNF)-alpha, on the beta-cells leads to massive insulitis and loss of ...
Zalzman Michal - - 2005
beta-Cell transplantation is viewed as a cure for type 1 diabetes; however, it is limited by the number of pancreas donors. Human stem cells offer the promise of an abundant source of insulin-producing cells, given the existence of methods for manipulating their differentiation. We have previously demonstrated that the expression ...
Schwaderer Andrew L - - 2006
The adaptation of the cortical collecting duct (CCD) to metabolic acidosis requires the polymerization and deposition in the extracellular matrix of the novel protein hensin. HCO3(-)-secreting beta-intercalated cells remove apical Cl-:HCO3(-) exchangers and may reverse functional polarity to secrete protons. Using intercalated cells in culture, we found that galectin-3 facilitated ...
Yang Jichun - - 2005
PANDER (pancreatic derived factor, FAM3B) is a novel cytokine, present in insulin secretory granules, that induces apoptosis of alpha and beta cells of mouse, rat, and human islets in a dose- and time-dependent manner, and may be implicated in diabetes. PANDER has the predicted secondary structure of 4 alpha-helical bundles ...
Mishra Lopa - - 2005
The past three decades have seen an unremitting quest to identify and understand gastrointestinal stem cells, their plasticity in differentiating across cell types, as well as their role in normal, regenerative, and cancer cells. A fascinating hallmark of stem cells is their ability to undergo assymetric cell division, which entails ...
Watt Nicole T - - 2005
The cellular prion protein (PrP(C)) is critical for the development of prion diseases. However, the physiological role of PrP(C) is less clear, although a role in the cellular resistance to oxidative stress has been proposed. PrP(C) is cleaved at the end of the copper-binding octapeptide repeats through the action of ...
Leung Yuk M - - 2005
We recently reported a transgenic [mouse insulin promoter (MIP)-green fluorescent protein (GFP)] mouse in which GFP expression is targeted to the pancreatic islet beta-cells to enable convenient identification of beta-cells as green cells. The GFP-expressing beta-cells of the MIP-GFP mouse were functionally indistinguishable from beta-cells of normal mice. Here we ...
Henriques Sónia Troeira - - 2005
The cell-penetrating peptide (CPP) pep-1 is capable of introducing large proteins into different cell lines, maintaining their biological activity. Two possible mechanisms have been proposed to explain the entrance of other CPPs in cells, endosomal-dependent and independent types. In this work, we evaluated the molecular mechanisms of pep-1-mediated cellular uptake ...
Collin Rob W J - - 2005
The amyloid-beta precursor protein (APP) is linked to Alzheimer's disease through its pathological proteolytic processing in the secretory pathway. Nevertheless, surprisingly little is known about the biosynthesis of endogenous APP. We therefore decided to investigate the intracellular fate of newly synthesized APP in a physiologically inducible neuroendocrine cell, the Xenopus ...
Jetton Thomas L - - 2005
The physiological mechanisms underlying the compensatory growth of beta-cell mass in insulin-resistant states are poorly understood. Using the insulin-resistant Zucker fatty (fa/fa) (ZF) rat and the corresponding Zucker lean control (ZLC) rat, we investigated the factors contributing to the age-/obesity-related enhancement of beta-cell mass. A 3.8-fold beta-cell mass increase was ...
Murozuka Yoshimi - - 2005
Lactoside primers (dodecyl lactoside derivatives) resemble intermediates in the biosynthetic pathway of glycolipids and, therefore, act as substrates for cellular enzyme-catalyzed glycosylation. To establish the optimal condition for the bioproduction of a large amount of valuable materials containing GM3-type oligosaccharides, two kinds of lactoside primers having the azido group in ...
Varga Andrea E - - 2005
Loss of actin stress fibers has been associated with cell transformation and metastasis. TGF-beta induction of stress fibers in epithelial cells requires high molecular weight tropomyosins encoded by TPM1 and TPM2 genes. Here, we investigated the mechanism underlying the failure of TGF-beta to induce stress fibers and inhibit cell migration ...
Erdal Esra - - 2005
We studied in vitro effects of glycogen synthase kinase 3beta (GSK3beta)-inhibitor lithium on the growth of hepatocellular carcinoma (HCC) cells. Lithium induced strong growth inhibition (> 70%) in 75% (n = 9 of 12) of cell lines, apparently independent from the status of major genes that are mutated in HCC ...
Zaslavsky Alexander - - 2005
Several different types of interactions between sphingosine-1-phosphate (S1P) receptors and platelet-derived growth factor receptor (PDGFR) have been revealed recently. In this work, we used HEK293 cells to further investigate the potential crosstalk. Interestingly, we observed that S1P specifically induced a PDGFR-dependent cell detachment in HEK293 cells, which could be inhibited ...
Stewart Lee - - 2005
AML1/Runx1 (Runx1) is a mammalian transcription factor that plays critical roles in regulating the differentiation of a number of different cell types. In the present study, we have utilized mice expressing beta-galactosidase (beta-gal) under the control of the Runx1 promoter to characterize the spatiotemporal expression pattern of Runx1 during retinogenesis. ...
Wang Dong - - 2005
AIM: To study the effect of caffeic acid phenethyl ester (CAPE) on proliferation, cell cycle, apoptosis and expression of beta-catenin in cultured human colorectal cancer (CRC) cell line HCT116. METHODS: HCT116 cells were treated with CAPE at serial concentrations of 80, 40, 20, 10, 5, 2.5 mg/L. The proliferative status ...
Kimple Michelle E - - 2005
Glucose-stimulated insulin secretion and beta-cell growth are important facets of pancreatic islet beta-cell biology. As a result, factors that modulate these processes are of great interest for the potential treatment of Type 2 diabetes. Here, we present evidence that the heterotrimeric G protein G(z) and its effectors, including some previously ...
Lee J H - - 2005
beta-catenin is a multifunctional molecule that functions in intercellular adhesion and signal transduction during assembly of AJs between Sertoli cells as well as between Sertoli cells and germ cells. To assess changes in the testicular beta-catenin in male infertility conditions, testicular tissues from obstructive azoospermia with normal spermatogenesis, spermatogenic arrest ...
Kozawa Junji - - 2005
In the adult pancreas, pre-existing beta cells, stem cells, and endocrine progenitor cells residing in the duct lining are considered important sources for beta-cell regeneration. A member of the epidermal growth factor (EGF) family, heparin binding (HB)-EGF, may promote this process. We examined whether HB-EGF gene transduction into duct cells ...
Franssen-van Hal Nicole L W - - 2005
Although in vitro models are often used in beta-carotene research, knowledge about the uptake and metabolism of beta-carotene in cell lines is lacking. We measured by HPLC the intracellular levels of beta-carotene and its metabolites in 9 human intestinal and lung cell lines after exposure to 1 microM beta-carotene during ...
Hampe C S - - 2005
Antibodies, due to their high specificities and retention, represent potential beta cell imaging agents, however their slow clearance from the blood may preclude their use. Antibody fragments (Fabs) have much higher clearance and if they can be made with similar binding characteristics, would be more efficacious agents. An existing beta ...
Schwartz George J - - 2005
PURPOSE OF REVIEW: The cortical collecting duct is able to secrete HCO3-, a state that can be converted to acid secretion during metabolic acidosis. Bicarbonate secretion in this segment is mediated by beta-intercalated cells whereas alpha-intercalated cells perform acid secretion. During metabolic acidosis, the number of beta-intercalated cells is reduced ...
Schepers Hein - - 2005
OBJECTIVE: To examine whether oncogenic Ras affects transforming growth factor (TGF)-beta-mediated cell-cycle arrest in hematopoietic cells and the downstream signal transduction pathway involved in the interference with TGF-beta-induced cell-cycle arrest. MATERIALS AND METHODS: Two leukemic cell lines bearing N-Ras(L61) mutations; HL-60 and TF-1, and the M1 cell line with wt ...
Waterworth A - - 2005
Microarray technology has burgeoned over the past few years from nucleic acid-based arrays to tissue microarrays (TMAs). This study aimed to develop a technique to incorporate cell lines into an array and to demonstrate the usefulness of this technique by performing immunohistochemistry for beta-catenin. Cell suspensions were prepared from 23 ...
Jo Junghyo - - 2005
Unlike isolated beta-cells, which usually produce continuous spikes or fast and irregular bursts, electrically coupled beta-cells are apt to exhibit robust bursting action potentials. We consider the noise induced by thermal fluctuations as well as that by channel-gating stochasticity and examine its effects on the action potential behavior of the ...
Cai Yi - - 2005
Cell polarity and asymmetric cell division are fundamental traits of all living cells and play an essential role in embryonic development, neuronal cell chirality formation, and maintenance of mammalian epithelial cell morphology. Heterotrimeric GTP-binding proteins (G proteins) are involved in directing cell polarity and asymmetric cell division in different organisms. ...
Nakamoto Kazutaka - - 2005
Beta-catenin functions both as a regulator of cadherin-mediated cell-cell adhesion and a mediator of Wnt signaling. Recently, caspase-3-dependent cleavage of beta-catenin was demonstrated to occur during apoptosis. Here, we show that beta-catenin is proteolytically cleaved in G401 Wilms' tumor cells that were detached from the culture dish. Beta-catenin cleavage products ...
Michihara Akihiro - - 2005
Chloroquine has been used as an anti-malarial drug and is known as a lysosomotropic amine as well. The effects of chloroquine on lysosomal integrity in cultured rat hepatocytes were studied by measuring lysosomal enzyme beta-glucuronidase (beta-G) or lysosomal membrane glycoprotein (lamp-1) in Percoll density gradient fractions, in the cytosolic fraction ...
Veronica Dudu
During cell communication, cells produce secreted signals termed morphogens, which traffic through the tissue until they are received by target, responding cells. Using the fruit fly Drosophila melanogaster as a model organism, I have studied transforming growth factor-beta (TGF-beta) signal from the secreting to the receiving cells in the developing ...
Bloch Konstantin - - 2005
Insulin-producing pancreatic beta-cells are known to be extremely susceptible to destruction, primarily by autoimmune mechanisms, infectious agents, and by chemical toxins that cause overt type I diabetes. As development of highly protected insulin-producing cells would be important for successful cell therapy of diabetic patients, gene transfection technique was utilized by ...
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