NR2B-containing NMDA receptors promote neural progenitor cell proliferation through CaMKIV/CREB pathway

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Mei, E-mail: limeihit@163.com; Jiangsu Key Laboratory of Neurodegeneration, Department of Pharmacology, Nanjing Medical University, Nanjing; Zhang, Dong-Qing

2011-08-12

Highlights: {yields} The NR2B component of the NMDARs is important for the NSPC proliferation. {yields} pCaMKIV and pCREB exist in NSPCs. {yields} The CaMKIV/CREB pathway mediates NSPC proliferation. -- Abstract: Accumulating evidence indicates the involvement of N-methyl-D-aspartate receptors (NMDARs) in regulating neural stem/progenitor cell (NSPC) proliferation. Functional properties of NMDARs can be markedly influenced by incorporating the regulatory subunit NR2B. Here, we aim to analyze the effect of NR2B-containing NMDARs on the proliferation of hippocampal NSPCs and to explore the mechanism responsible for this effect. NSPCs were shown to express NMDAR subunits NR1 and NR2B. The NR2B selective antagonist, Romore » 25-6981, prevented the NMDA-induced increase in cell proliferation. Moreover, we demonstrated that the phosphorylation levels of calcium/calmodulin-dependent protein kinase IV (CaMKIV) and cAMP response element binding protein (CREB) were increased by NMDA treatment, whereas Ro 25-6981 decreased them. The role that NR2B-containing NMDARs plays in NSPC proliferation was abolished when CREB phosphorylation was attenuated by CaMKIV silencing. These results suggest that NR2B-containing NMDARs have a positive role in regulating NSPC proliferation, which may be mediated through CaMKIV phosphorylation and subsequent induction of CREB activation.« less

Proliferative effects of 'fibre' on the intestinal epithelium: relationship to gastrin, enteroglucagon and PYY.

PubMed Central

Goodlad, R A; Lenton, W; Ghatei, M A; Adrian, T E; Bloom, S R; Wright, N A

1987-01-01

Refeeding starved rats with a fibre free 'elemental' diet increased crypt cell production rate (CCPR) in the proximal small intestine but not in the distal regions of the gut. Little effect on CCPR was seen when inert bulk (kaolin) was added to the 'elemental' diet. Addition of a poorly fermentable dietary 'fibre' (purified wood cellulose) had little effect on intestinal epithelial cell proliferation except in the distal colon where it significantly increased CCPR. A more readily fermentable 'fibre' (purified wheat bran) caused a large proliferative response in the proximal, mid and distal colon and in the distal small intestine. A gel forming 'fibre' also stimulated proliferation in the distal colon. There was no significant correlation between CCPR and plasma gastrin concentrations, but plasma enteroglucagon concentrations were significantly correlated with CCPR in almost all the sites studied. Plasma PYY concentrations also showed some correlation with CCPR, especially in the colon. Thus, whilst inert bulk cannot stimulate colonic epithelial cell proliferation, fermentable 'fibre' is capable of stimulating proliferation in the colon, and especially in the distal colon: it can also stimulate proliferation in the distal small intestine and it is likely that plasma enteroglucagon may have a role to play in this process. PMID:2826311

Lyt-2+ cells. Requirements for concanavalin A-induced proliferation and interleukin 2 production.

PubMed

Kern, D E; Lachmann, L B; Greenberg, P D

1987-11-01

The requirements for inducing Lyt-2+ T cell proliferation in response to concanavalin A (Con A) were examined. Purified Lyt-2+ or L3T4+ spleen cells of C57BL/6 origin were stimulated with Con A and syngeneic macrophages (MO) in the presence of monoclonal antibodies to T cell markers or to polymorphic determinants on major histocompatibility complex molecules, and assessed for the ability to proliferate and to produce interleukin (IL) 2. alpha I-Ab failed to inhibit the Con A response of Lyt-2+ cells at dilutions that significantly inhibited the response of L3T4+ cells. In contrast, alphaKb/Db or alpha Lyt-2.2 specifically inhibited the response of Lyt-2+ cells, but not L3T4+ cells. The ability of alpha Kb/Db and of alpha Lyt-2.2 to inhibit the response of Lyt-2+ cells was dependent upon the concentration of Con A. These data demonstrate that optimal triggering of T cell subsets to proliferate and to produce IL-2 in response to Con A requires interactions with the appropriate restricting major histocompatibility complex molecule. The role of accessory cells in Lyt-2+ Con A-induced proliferation and IL-2 production was also investigated. Purified Lyt-2+ cells and purified L3T4+ cells failed to respond to Con A in the absence of MO. IL-1 reconstituted the response when MO were limiting, but failed to restore the response of either Lyt-2+ or L3T4+ cells when T cells were rigorously purified to remove all MO. These results demonstrate that triggering Lyt-2+ T cells, like L3T4+ T cells, requires accessory cells, and that this does not merely reflect a requirement for IL-1 production. Thus, Con A-induced proliferation and IL-2 production by Lyt-2+ T cells requires intimate contact with accessory cells and interactions dependent upon the class I-restricting element.

Estrogen-dependent downregulation of hairy and enhancer of split homolog-1 gene expression in breast cancer cells is mediated via a 3' distal element.

PubMed

Müller, Patrick; Merrell, Kenneth W; Crofts, Justin D; Rönnlund, Caroline; Lin, Chin-Yo; Gustafsson, Jan-Ake; Ström, Anders

2009-03-01

Regulation of hairy and enhancer of split homologue-1 (HES-1) by estradiol and all-trans retinoic acid affects proliferation of human breast cancer cells. Here, we identify and characterize cis-regulatory elements involved in HES-1 regulation. In the distal 5' promoter of the HES-1 gene, we found a retinoic acid response element and in the distal 3' region, an estrogen receptor alpha(ER)alpha binding site. The ERalpha binding site, composed of an estrogen response element (ERE) and an ERE half-site, is important for both ERalpha binding and transcriptional regulation. Chromatin immunoprecipitation assays revealed that ERalpha is recruited to the ERE and associates with the HES-1 promoter. We also show recruitment of nuclear receptor co-regulators to the ERE in response to estradiol, followed by a decrease in histone acetylation and RNA polymerase II docking in the HES-1 promoter region. Our findings are consistent with a novel type of repressive estrogen response element in the distal 3' region of the HES-1 gene.

Modulation of Estrogen Response Element-Driven Gene Expressions and Cellular Proliferation with Polar Directions by Designer Transcription Regulators

PubMed Central

Muyan, Mesut; Güpür, Gizem; Yaşar, Pelin; Ayaz, Gamze; User, Sırma Damla; Kazan, Hasan Hüseyin; Huang, Yanfang

2015-01-01

Estrogen receptor α (ERα), as a ligand-dependent transcription factor, mediates 17β-estradiol (E2) effects. ERα is a modular protein containing a DNA binding domain (DBD) and transcription activation domains (AD) located at the amino- and carboxyl-termini. The interaction of the E2-activated ERα dimer with estrogen response elements (EREs) of genes constitutes the initial step in the ERE-dependent signaling pathway necessary for alterations of cellular features. We previously constructed monomeric transcription activators, or monotransactivators, assembled from an engineered ERE-binding module (EBM) using the ERα-DBD and constitutively active ADs from other transcription factors. Monotransactivators modulated cell proliferation by activating and repressing ERE-driven gene expressions that simulate responses observed with E2-ERα. We reasoned here that integration of potent heterologous repression domains (RDs) into EBM could generate monotransrepressors that alter ERE-bearing gene expressions and cellular proliferation in directions opposite to those observed with E2-ERα or monotransactivators. Consistent with this, monotransrepressors suppressed reporter gene expressions that emulate the ERE-dependent signaling pathway. Moreover, a model monotransrepressor regulated DNA synthesis, cell cycle progression and proliferation of recombinant adenovirus infected ER-negative cells through decreasing as well as increasing gene expressions with polar directions compared with E2-ERα or monotransactivator. Our results indicate that an ‘activator’ or a ‘repressor’ possesses both transcription activating/enhancing and repressing/decreasing abilities within a chromatin context. Offering a protein engineering platform to alter signal pathway-specific gene expressions and cell growth, our approach could also be used for the development of tools for epigenetic modifications and for clinical interventions wherein multigenic de-regulations are an issue. PMID:26295471

TEC protein tyrosine kinase is involved in the Erk signaling pathway induced by HGF

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Feifei; Jiang, Yinan; Zheng, Qiping

Research highlights: {yields} TEC is rapidly tyrosine-phosphorylated and activated by HGF-stimulation in vivo or after partial hepatectomy in mice. {yields} TEC enhances the activity of Elk and serum response element (SRE) in HGF signaling pathway in hepatocyte. {yields} TEC promotes hepatocyte proliferation through the Erk-MAPK pathway. -- Abstract: Background/aims: TEC, a member of the TEC family of non-receptor type protein tyrosine kinases, has recently been suggested to play a role in hepatocyte proliferation and liver regeneration. This study aims to investigate the putative mechanisms of TEC kinase regulation of hepatocyte differentiation, i.e. to explore which signaling pathway TEC is involvedmore » in, and how TEC is activated in hepatocyte after hepatectomy and hepatocyte growth factor (HGF) stimulation. Methods: We performed immunoprecipitation (IP) and immunoblotting (IB) to examine TEC tyrosine phosphorylation after partial hepatectomy in mice and HGF stimulation in WB F-344 hepatic cells. The TEC kinase activity was determined by in vitro kinase assay. Reporter gene assay, antisense oligonucleotide and TEC dominant negative mutant (TEC{sup KM}) were used to examine the possible signaling pathways in which TEC is involved. The cell proliferation rate was evaluated by {sup 3}H-TdR incorporation. Results: TEC phosphorylation and kinase activity were increased in 1 h after hepatectomy or HGF treatment. TEC enhanced the activity of Elk and serum response element (SRE). Inhibition of MEK1 suppressed TEC phosphorylation. Blocking TEC activity dramatically decreased the activation of Erk. Reduced TEC kinase activity also suppressed the proliferation of WB F-344 cells. These results suggest TEC is involved in the Ras-MAPK pathway and acts between MEK1 and Erk. Conclusions: TEC promotes hepatocyte proliferation and regeneration and is involved in HGF-induced Erk signaling pathway.« less

The human apolipoprotein AV gene is regulated by peroxisome proliferator-activated receptor-alpha and contains a novel farnesoid X-activated receptor response element.

PubMed

Prieur, Xavier; Coste, Herve; Rodriguez, Joan C

2003-07-11

The newly identified apolipoprotein AV (apoAV) gene is a key player in determining plasma triglyceride concentrations. Because hypertriglyceridemia is a major independent risk factor in coronary artery disease, the understanding of the regulation of the expression of this gene is of considerable importance. We presently characterize the structure, the transcription start site, and the promoter of the human apoAV gene. Since the peroxisome proliferator-activated receptor-alpha (PPARalpha) and the farnesoid X-activated receptor (FXR) have been shown to modulate the expression of genes involved in triglyceride metabolism, we evaluated the potential role of these nuclear receptors in the regulation of apoAV transcription. Bile acids and FXR induced the apoAV gene promoter activity. 5'-Deletion, mutagenesis, and gel shift analysis identified a heretofore unknown element at positions -103/-84 consisting of an inverted repeat of two consensus receptor-binding hexads separated by 8 nucleotides (IR8), which was required for the response to bile acid-activated FXR. The isolated IR8 element conferred FXR responsiveness on a heterologous promoter. On the other hand, in apoAV-expressing human hepatic Hep3B cells, transfection of PPARalpha specifically enhanced apoAV promoter activity. By deletion, site-directed mutagenesis, and binding analysis, a PPARalpha response element located 271 bp upstream of the transcription start site was identified. Finally, treatment with a specific PPARalpha activator led to a significant induction of apoAV mRNA expression in hepatocytes. The identification of apoAV as a PPARalpha target gene has major implications with respect to mechanisms whereby pharmacological PPARalpha agonists may exert their beneficial hypotriglyceridemic actions.

Two estrogen response element sequences near the PCNA gene are not responsible for its estrogen-enhanced expression in MCF7 cells.

PubMed

Wang, Cheng; Yu, Jie; Kallen, Caleb B

2008-01-01

The proliferating cell nuclear antigen (PCNA) is an essential component of DNA replication, cell cycle regulation, and epigenetic inheritance. High expression of PCNA is associated with poor prognosis in patients with breast cancer. The 5'-region of the PCNA gene contains two computationally-detected estrogen response element (ERE) sequences, one of which is evolutionarily conserved. Both of these sequences are of undocumented cis-regulatory function. We recently demonstrated that estradiol (E2) enhances PCNA mRNA expression in MCF7 breast cancer cells. MCF7 cells proliferate in response to E2. Here, we demonstrate that E2 rapidly enhanced PCNA mRNA and protein expression in a process that requires ERalpha as well as de novo protein synthesis. One of the two upstream ERE sequences was specifically bound by ERalpha-containing protein complexes, in vitro, in gel shift analysis. Yet, each ERE sequence, when cloned as a single copy, or when engineered as two tandem copies of the ERE-containing sequence, was not capable of activating a luciferase reporter construct in response to E2. In MCF7 cells, neither ERE-containing genomic region demonstrated E2-dependent recruitment of ERalpha by sensitive ChIP-PCR assays. We conclude that E2 enhances PCNA gene expression by an indirect process and that computational detection of EREs, even when evolutionarily conserved and when near E2-responsive genes, requires biochemical validation.

Regulation of the human SLC25A20 expression by peroxisome proliferator-activated receptor alpha in human hepatoblastoma cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tachibana, Keisuke, E-mail: nya@phs.osaka-u.ac.jp; Takeuchi, Kentaro; Inada, Hirohiko

2009-11-20

Solute carrier family 25, member 20 (SLC25A20) is a key molecule that transfers acylcarnitine esters in exchange for free carnitine across the mitochondrial membrane in the mitochondrial {beta}-oxidation. The peroxisome proliferator-activated receptor alpha (PPAR{alpha}) is a ligand-activated transcription factor that plays an important role in the regulation of {beta}-oxidation. We previously established tetracycline-regulated human cell line that can be induced to express PPAR{alpha} and found that PPAR{alpha} induces the SLC25A20 expression. In this study, we analyzed the promoter region of the human slc25a20 gene and showed that PPAR{alpha} regulates the expression of human SLC25A20 via the peroxisome proliferator responsive element.

Does dietary fibre stimulate intestinal epithelial cell proliferation in germ free rats?

PubMed Central

Goodlad, R A; Ratcliffe, B; Fordham, J P; Wright, N A

1989-01-01

The aim of the present experiment was to investigate the role of hind gut fermentation in the proliferative response of the intestinal epithelium to dietary fibre. We have previously shown that refeeding starved rats with an elemental diet supplemented with fermentable dietary fibre (but not inert bulk) is capable of stimulating intestinal epithelial cell proliferation throughout the gastrointestinal tract. Three groups of 10 germ free (GF) rats and three groups of 10 conventional (CV) rats, were used. All groups were starved for three days and then refed for two days with either an elemental diet (Flexical); Flexical plus 30% kaolin; or Flexical plus 30% of a fibre mixture. Cell production was determined by the accumulation of vincristine arrested metaphases in microdissected crypts. There was no significant difference between refeeding the rats with an elemental diet alone or with kaolin supplementation, however, the addition of fibre in CV rats was associated with a significant increase in intestinal crypt cell production rate in both the small intestine (p less than 0.01) and the colon (p less than 0.001). This marked proliferative effects of fibre was abolished in the GF rats. It can be concluded that it is the products of hind gut fermentation, not fibre per se that stimulate intestinal epithelial cell proliferation in the colon and small intestine. PMID:2546871

Sex change strategy and the aromatase genes.

PubMed

Gardner, L; Anderson, T; Place, A R; Dixon, B; Elizur, A

2005-04-01

Sequential hermaphroditism is a common reproductive strategy in many teleosts. Steroid production is known to mediate both the natural and induced sex change, yet beyond this the physiology directing this process has received little attention. Cytochrome P450 aromatase is a key enzyme in the hormonal pathway catalysing the conversion of sex steroids, androgens to oestrogens, and thus is highly relevant to the process of sex change. This study reports the isolation of cDNA sequences for aromatase isoforms CYP19A1 and CYP19A2 from teleost species representing three forms of sexual hermaphroditism: Lates calcarifer (protandry), Cromileptes altivelis (protogyny), and Gobiodon histrio (bi-directional). Deduced amino acid analysis of these isoforms with other reported isoforms from gonochoristic (single sex) teleosts revealed 56-95% identity within the same isoform while only 48-65% identity between isoforms irrespective of species and sexual strategy. Phylogenetic analysis supported this result separating sequences into isoform exclusive clades in spite of species apparent evolutionary distance. Furthermore, this study isolates 5' flanking regions of all above genes and describes putative cis-acting elements therein. Elements identified include steroidogenic factor 1 binding site (SF-1), oestrogen response element (ERE), progesterone response element (PRE), androgen response element (ARE), glucocorticoid response elements (GRE), peroxisome proliferator-activated receptor alpha/retinoid X receptor alpha heterodimer responsive element (PPARalpha/RXRalpha), nuclear factor kappabeta (NF-kappabeta), SOX 5, SOX 9, and Wilms tumor suppressor (WTI). A hypothetical in vivo model was constructed for both isoforms highlighting potential roles of these putative cis-acting elements with reference to normal function and sexual hermaphroditism.

Retinoid X receptor and peroxisome proliferator-activated receptor activate an estrogen responsive gene independent of the estrogen receptor.

PubMed

Nuñez, S B; Medin, J A; Braissant, O; Kemp, L; Wahli, W; Ozato, K; Segars, J H

1997-03-14

Estrogen receptors regulate transcription of genes essential for sexual development and reproductive function. Since the retinoid X receptor (RXR) is able to modulate estrogen responsive genes and both 9-cis RA and fatty acids influenced development of estrogen responsive tumors, we hypothesized that estrogen responsive genes might be modulated by RXR and the fatty acid receptor (peroxisome proliferator-activated receptor, PPAR). To test this hypothesis, transfection assays in CV-1 cells were performed with an estrogen response element (ERE) coupled to a luciferase reporter construct. Addition of expression vectors for RXR and PPAR resulted in an 11-fold increase in luciferase activity in the presence of 9-cis RA. Furthermore, mobility shift assays demonstrated binding of RXR and PPAR to the vitellogenin A2-ERE and an ERE in the oxytocin promoter. Methylation interference assays demonstrated that specific guanine residues required for RXR/PPAR binding to the ERE were similar to residues required for ER binding. Moreover, RXR domain-deleted constructs in transfection assays showed that activation required RXR since an RXR delta AF-2 mutant completely abrogated reporter activity. Oligoprecipitation binding studies with biotinylated ERE and (35)S-labeled in vitro translated RXR constructs confirmed binding of delta AF-2 RXR mutant to the ERE in the presence of baculovirus-expressed PPAR. Finally, in situ hybridization confirmed RXR and PPAR mRNA expression in estrogen responsive tissues. Collectively, these data suggest that RXR and PPAR are present in reproductive tissues, are capable of activating estrogen responsive genes and suggest that the mechanism of activation may involve direct binding of the receptors to estrogen response elements.

Ca2+/Calmodulin-dependent kinase II signaling causes skeletal overgrowth and premature chondrocyte maturation.

PubMed

Taschner, Michael J; Rafigh, Mehran; Lampert, Fabienne; Schnaiter, Simon; Hartmann, Christine

2008-05-01

The long bones of vertebrate limbs originate from cartilage templates and are formed by the process of endochondral ossification. This process requires that chondrocytes undergo a progressive maturation from proliferating to postmitotic prehypertrophic to mature, hypertrophic chondrocytes. Coordinated control of proliferation and maturation regulates growth of the skeletal elements. Various signals and pathways have been implicated in orchestrating these processes, but the underlying intracellular molecular mechanisms are often not entirely known. Here we demonstrated in the chick using replication-competent retroviruses that constitutive activation of Calcium/Calmodulin-dependent kinase II (CaMKII) in the developing wing resulted in elongation of skeletal elements associated with premature differentiation of chondrocytes. The premature maturation of chondrocytes was a cell-autonomous effect of constitutive CaMKII signaling associated with down-regulation of cell-cycle regulators and up-regulation of chondrocyte maturation markers. In contrast, the elongation of the skeletal elements resulted from a non-cell autonomous up-regulation of the Indian hedgehog responsive gene encoding Parathyroid-hormone-related peptide. Reduction of endogenous CaMKII activity by overexpressing an inhibitory peptide resulted in shortening of the skeletal elements associated with a delay in chondrocyte maturation. Thus, CaMKII is an essential component of intracellular signaling pathways regulating chondrocyte maturation.

Evidence for deterministic chaos in aperiodic oscillations of acute lymphoblastic leukemia cells in long-term culture

NASA Astrophysics Data System (ADS)

Lambrou, George I.; Chatziioannou, Aristotelis; Vlahopoulos, Spiros; Moschovi, Maria; Chrousos, George P.

Biological systems are dynamic and possess properties that depend on two key elements: initial conditions and the response of the system over time. Conceptualizing this on tumor models will influence conclusions drawn with regard to disease initiation and progression. Alterations in initial conditions dynamically reshape the properties of proliferating tumor cells. The present work aims to test the hypothesis of Wolfrom et al., that proliferation shows evidence for deterministic chaos in a manner such that subtle differences in the initial conditions give rise to non-linear response behavior of the system. Their hypothesis, tested on adherent Fao rat hepatoma cells, provides evidence that these cells manifest aperiodic oscillations in their proliferation rate. We have tested this hypothesis with some modifications to the proposed experimental setup. We have used the acute lymphoblastic leukemia cell line CCRF-CEM, as it provides an excellent substrate for modeling proliferation dynamics. Measurements were taken at time points varying from 24h to 48h, extending the assayed populations beyond that of previous published reports that dealt with the complex dynamic behavior of animal cell populations. We conducted flow cytometry studies to examine the apoptotic and necrotic rate of the system, as well as DNA content changes of the cells over time. The cells exhibited a proliferation rate of nonlinear nature, as this rate presented oscillatory behavior. The obtained data have been fit in known models of growth, such as logistic and Gompertzian growth.

Advanced glycation end products promote ChREBP expression and cell proliferation in liver cancer cells by increasing reactive oxygen species.

PubMed

Chen, Hanbei; Li, Yakui; Zhu, Yemin; Wu, Lifang; Meng, Jian; Lin, Ning; Yang, Dianqiang; Li, Minle; Ding, WenJin; Tong, Xuemei; Su, Qing

2017-08-01

The aim of the study was to elucidate the mechanism by which advanced glycation end products (AGEs) promote cell proliferation in liver cancer cells.We treated liver cancer HepG2 cells with 200 mg/L AGEs or bovine serum albumin (BSA) and assayed for cell viability, cell cycle, and apoptosis. We performed real-time PCR and Western blot analysis for RNA and protein levels of carbohydrate responsive element-binding protein (ChREBP) in AGEs- or BSA-treated HepG2 cells. We analyzed the level of reactive oxygen species (ROS) in HepG2 cells treated with AGEs or BSA.We found that increased S-phase cell percentage and decreased apoptosis contributed to AGEs-induced liver cancer cell proliferation. Real-time PCR and Western blot analysis showed that AGEs stimulated RNA and protein levels of ChREBP, a transcription factor promoting glycolysis and maintaining cell proliferation in liver cancer cells. Intriguingly, the level of ROS was higher in AGEs-treated liver cancer cells. Treating liver cancer cells with antioxidant N-acetyl cystein (NAC) partly blocked AGEs-induced ChREBP expression and cell proliferation.Our results suggest that the AGEs-ROS-ChREBP pathway plays a critical role in promoting ChREBP expression and liver cancer cell proliferation.

Fabrication of mediator-free hybrid nano-interfaced electrochemical biosensor for monitoring cancer cell proliferation.

PubMed

Madhurantakam, Sasya; Jayanth Babu, K; Balaguru Rayappan, John Bosco; Krishnan, Uma Maheswari

2017-01-15

Glucose, a chief energy source in cellular metabolism, has a significant role in cell proliferation. Cancer cells utilize more glucose than normal cells to meet the energy demand arising due to their uncontrolled proliferation. The present work reports the development of a nano-interfaced amperometric biosensor for rapid and accurate monitoring of glucose utilization by cancer cells. A hybrid nano-interface comprising a blend of carbon nanotubes (CNTs) and graphene (GR) was employed to enhance the surface area of the working electrode and favour direct electron transfer. Glucose oxidase (GOx) immobilized on the interface serves as the sensing element due to its high selectivity and sensitivity towards glucose. Utilization of glucose was monitored at pre-determined time intervals in MiaPaCa-2 cancer cells. The results obtained from the amperometric technique were compared with the values obtained from a commercial glucometer. Alamar blue assay was performed to check the proliferation rate of the cells. A good correlation was obtained between the proliferation rate and glucose utilization. The designed biosensor was found to be unaffected by the presence of potential interferents and hence may serve as a novel in vitro tool to rapidly quantify the proliferation rates of cancer cells in response to different treatment strategies. Copyright © 2016 Elsevier B.V. All rights reserved.

24-Methylenecycloartanyl ferulate, a major compound of γ-oryzanol, promotes parvin-beta expression through an interaction with peroxisome proliferator-activated receptor-gamma 2 in human breast cancer cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Heon Woong; Lim, Eun Joung; Jang, Hwan Hee

2015-12-25

Parvin-β is an adaptor protein that binds to integrin-linked kinase (ILK) and is significantly downregulated in breast tumors and breast cancer cell lines. We treated the breast cancer cell line MCF7 with 24-methylenecycloartanyl ferulate (24-MCF), a γ-oryzanol compound. We observed upregulation of parvin-β (GenBank Accession No. (AF237769)) and peroxisome proliferator-activated receptor (PPAR)-γ2 (GenBank Accession No. (NM-015869)). Among γ-oryzanol compounds, only treatment with 24-MCF led to the formation of reverse transcription-PCR products of parvin-β (650 and 500 bp) and PPAR-γ2 (580 bp) in MCF7 cells, but not in T47D, SK-BR-3, or MDA-MB-231 cells. 24-MCF treatment increased the mRNA and protein levels of parvin-β inmore » MCF7 cells in a dose-dependent manner. We hypothesized that there is a correlation between parvin-β expression and induction of PPAR-γ2. This hypothesis was investigated by using a promoter-reporter assay, chromatin immunoprecipitation, and an electrophoretic mobility shift assay. 24-MCF treatment induced binding of PPAR-γ2 to a peroxisome proliferator response element-like cis-element (ACTAGGACAAAGGACA) in the parvin-β promoter in MCF7 cells in a dose-dependent manner. 24-MCF treatment significantly decreased anchorage-independent growth and inhibited cell movement in comparison to control treatment with dimethyl sulfoxide. 24-MCF treatment reduced the levels of GTP-bound Rac1 and Cdc42. Evaluation of Akt1 inhibition by 24-MCF revealed that the half maximal effective concentration was 33.3 μM. Docking evaluations revealed that 24-MCF binds to the ATP-binding site of Akt1(PDB ID: (3OCB)) and the compound binding energy is -8.870 kcal/mol. Taken together, our results indicate that 24-MCF treatment increases parvin-β expression, which may inhibit ILK downstream signaling. - Highlights: • Treatment with 24-MCF increases gene expression of parvin-β and PPAR-ϒ2 in MCF7 cells. • PPAR-ϒ2 interacts with the parvin-β gene via its peroxisome proliferator response element-like cis-element. • 24-MCF treatment inhibits anchorage-dependent growth of MCF7 cells. • 24-MCF treatment inhibits MCF7 cell migration and Rac1 and Cdc42 activation. • 24-MCF may be a new ATP-competitive Akt1 inhibitor that binds to the ATP-binding site of Akt1.« less

Proliferation resistance design of a plutonium cycle (Proliferation Resistance Engineering Program: PREP)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sorenson, R.J.; Roberts, F.P.; Clark, R.G.

1979-01-19

This document describes the proliferation resistance engineering concepts developed to counter the threat of proliferation of nuclear weapons in an International Fuel Service Center (IFSC). The basic elements of an International Fuel Service Center are described. Possible methods for resisting proliferation such as processing alternatives, close-coupling of facilities, process equipment layout, maintenance philosophy, process control, and process monitoring are discussed. Political and institutional issues in providing proliferation resistance for an International Fuel Service Center are analyzed. The conclusions drawn are (1) use-denial can provide time for international response in the event of a host nation takeover. Passive use-denial is moremore » acceptable than active use-denial, and acceptability of active-denial concepts is highly dependent on sovereignty, energy dependence and economic considerations; (2) multinational presence can enhance proliferation resistance; and (3) use-denial must be nonprejudicial with balanced interests for governments and/or private corporations being served. Comparisons between an IFSC as a national facility, an IFSC with minimum multinational effect, and an IFSC with maximum multinational effect show incremental design costs to be less than 2% of total cost of the baseline non-PRE concept facility. The total equipment acquisition cost increment is estimated to be less than 2% of total baseline facility costs. Personnel costs are estimated to increase by less than 10% due to maximum international presence. 46 figures, 9 tables.« less

Estrogenic Activity of Hyperforin in MCF-7 Human Breast Cancer Cells Transfected with Estrogen Receptor.

PubMed

Kwon, Joseph; Oh, Kyung Seo; Cho, Se-Young; Bang, Mi Ae; Kim, Hwan Seon; Vaidya, Bipin; Kim, Duwoon

2016-11-01

Hyperforin, a major active compound of St. John's wort extract, affects estrogenic activity. In this study, the compound evoked estrogen response element-dependent luciferase activity and cell proliferation in MCF-7 cells. Hyperforin-induced cell proliferation was significantly inhibited by the estrogen receptor antagonist ICI 182,780. These results suggested that hyperforin had estrogenic and cell proliferation activities, which were stimulated via the estrogen receptor. Compared to 17 β -estradiol, hyperforin showed significantly lower estrogenic activity and cell proliferation. The mechanism underlying the estrogenic activity of hyperforin was unknown, therefore, in this study, for the first time, the expression and post-translational modification of proteins were determined and compared among control, 17 β -estradiol-treated, and hyperforin-treated cells using proteomic techniques. A total of 453 proteins were identified, of which 282 proteins were significantly modulated in hyperforin-treated cells compared to 17 β -estradiol-treated cells. Ingenuity pathway analysis also demonstrated that hyperforin treatment induced less cell proliferation than 17 β -estradiol by downregulating estrogen receptor 1. Protein network analysis showed that cell proliferation was regulated mainly by cyclin D1 and extracellular signal-regulated kinases. In conclusion, although, hyperforin exhibited lower estrogenic activity than 17 β -estradiol, the compound induced lower levels of cancer cell proliferation in vitro . Georg Thieme Verlag KG Stuttgart · New York.

A prediction of cell differentiation and proliferation within a collagen-glycosaminoglycan scaffold subjected to mechanical strain and perfusive fluid flow.

PubMed

Stops, A J F; Heraty, K B; Browne, M; O'Brien, F J; McHugh, P E

2010-03-03

Mesenchymal stem cell (MSC) differentiation can be influenced by biophysical stimuli imparted by the host scaffold. Yet, causal relationships linking scaffold strain magnitudes and inlet fluid velocities to specific cell responses are thus far underdeveloped. This investigation attempted to simulate cell responses in a collagen-glycosaminoglycan (CG) scaffold within a bioreactor. CG scaffold deformation was simulated using micro-computed tomography (CT) and an in-house finite element solver (FEEBE/linear). Similarly, the internal fluid velocities were simulated using the afore-mentioned microCT dataset with a computational fluid dynamics solver (ANSYS/CFX). From the ensuing cell-level mechanics, albeit octahedral shear strain or fluid velocity, the proliferation and differentiation of the representative cells were predicted from deterministic functions. Cell proliferation patterns concurred with previous experiments. MSC differentiation was dependent on the level of CG scaffold strain and the inlet fluid velocity. Furthermore, MSC differentiation patterns indicated that specific combinations of scaffold strains and inlet fluid flows cause phenotype assemblies dominated by single cell types. Further to typical laboratory procedures, this predictive methodology demonstrated loading-specific differentiation lineages and proliferation patterns. It is hoped these results will enhance in-vitro tissue engineering procedures by providing a platform from which the scaffold loading applications can be tailored to suit the desired tissue. Copyright 2009 Elsevier Ltd. All rights reserved.

The PROGINS polymorphism of the human progesterone receptor diminishes the response to progesterone.

PubMed

Romano, Andrea; Delvoux, Bert; Fischer, Dagmar-Christiane; Groothuis, Patrick

2007-02-01

The human progesterone receptor (PR) is a ligand-dependent transcription factor and two isoforms, (PRA and PRB), can be distinguished. PROGINS, a PR polymorphic variant, affects PRA and PRB and acts as a risk-modulating factor in several gynaecological disorders. Little is known about the functional consequences of this variant. Here, we characterise the properties of PROGINS with respect to transcription, mRNA maturation, protein activity and proliferation. PROGINS is characterised by a 320 bp PV/HS-1 Alu insertion in intron G and two point mutations, V660L in exon 4 and H770H (silent substitution) in exon 5. The Alu element contains a half oestrogen-response element/Sp1-binding site (Alu-ERE/Sp1), which acts as an in-cis intronic enhancer leading to increased transcription of the PROGINS allele in response to 17beta-oestradiol. Moreover, Alu insertions in the human genome are frequently methylated. Our data indicate that the PROGINS-Alu does not affect gene transcription due to DNA methylation. However, the Alu element reduced the stability of the PROGINS transcript compared with the CP allele and does not generate splice variants. The amino acid substitution (V600L) in exon 4 leads to differences in PR phosphorylation and degradation in the two PR variants upon ligand binding, most likely as a result of differences in the three-dimensional structures of the two PR variants. As a consequence, the PR-L660 (PROGINS) variant (1) displays decreased transactivation activity in a luciferase reporter system and (2) is less efficient in opposing cell proliferation in hamster ovarian cells expressing human PRA, when compared with the PR-V660 (most common variant). Taken together, our results indicate that the PROGINS variant of PR is less responsive to progestin compared with the most common PR because of (i) reduced amounts of gene transcript and (ii) decreased protein activity.

N-3 polyunsaturated fatty acid regulation of hepatic gene transcription

PubMed Central

Jump, Donald B.

2009-01-01

Purpose of review The liver plays a central role in whole body lipid metabolism and adapts rapidly to changes in dietary fat composition. This adaption involves changes in the expression of genes involved in glycolysis, de-novo lipogenesis, fatty acid elongation, desaturation and oxidation. This review brings together metabolic and molecular studies that help explain n-3 (omega-3) polyunsaturated fatty acid regulation of hepatic gene transcription. Recent findings Dietary n-3 polyunsaturated fatty acid regulates hepatic gene expression by targeting three major transcriptional regulatory networks: peroxisome proliferator-activated receptor α, sterol regulatory element binding protein-1 and the carbohydrate regulatory element binding protein/Max-like factor X heterodimer. 22 : 6,n-3, the most prominent n-3 polyunsaturated fatty acid in tissues, is a weak activator of peroxisome proliferator-activated receptor α. Hepatic metabolism of 22 : 6,n-3, however, generates 20 : 5,n-3, a strong peroxisome proliferator-activated receptor α activator. In contrast to peroxisome proliferator-activated receptor α, 22 : 6,n-3 is the most potent fatty acid regulator of hepatic sterol regulatory element binding protein-1. 22 : 6,n-3 suppresses sterol regulatory element binding protein-1 gene expression while enhancing degradation of nuclear sterol regulatory element binding protein-1 through 26S proteasome and Erk1/2-dependent mechanisms. Both n-3 and n-6 polyunsaturated fatty acid suppress carbohydrate regulatory element binding protein and Max-like factor X nuclear abundance and interfere with glucose-regulated hepatic metabolism. Summary These studies have revealed unique mechanisms by which specific polyunsaturated fatty acids control peroxisome proliferator activated receptor α, sterol regulatory element binding protein-1 and carbohydrate regulatory element binding protein/Max-like factor X function. As such, specific metabolic and signal transduction pathways contribute significantly to the fatty acid regulation of these transcription factors and their corresponding regulatory networks. PMID:18460914

Sterol regulatory element-binding protein-1 participates in the regulation of fatty acid synthase expression in colorectal neoplasia.

PubMed

Li, J N; Mahmoud, M A; Han, W F; Ripple, M; Pizer, E S

2000-11-25

Endogenous fatty acid synthesis has been observed in certain rapidly proliferating normal and neoplastic tissues. Sterol regulatory element-binding proteins (SREBPs) are transcription factors that regulate the expression of lipogenic genes including fatty acid synthase (FAS), the major biosynthetic enzyme for fatty acid synthesis. We have previously shown that SREBP-1, FAS, and Ki-67, a proliferation marker, colocalized in the crypts of the fetal gastrointestinal tract epithelium. This study sought to determine whether SREBP-1 participates in the regulation of proliferation-associated fatty acid synthesis in colorectal neoplasia. An immunohistochemical analysis of SREBP-1, FAS, and Ki-67 expression in 25 primary human colorectal carcinoma specimens showed colocalization in 22 of these. To elucidate a functional linkage between SREBP-1 activation and proliferation-associated FA synthesis, SREBP-1 and FAS content were assayed during the adaptive response of cultured HCT116 colon carcinoma cells to pharmacological inhibition of FA synthesis. Cerulenin and TOFA each inhibited the endogenous synthesis of fatty acids in a dose-dependent manner and each induced increases in both precursor and mature forms of SREBP-1. Subsequently, both the transcriptional activity of the FAS promoter in a luciferase reporter gene construct and the FAS expression increased. These results demonstrate that tumor cells recognize and respond to a deficiency in endogenous fatty acid synthesis by upregulating both SREBP-1 and FAS expression and support the model that SREBP-1 participates in the transcriptional regulation of lipogenic genes in colorectal neoplasia. Copyright 2000 Academic Press.

Effects of pyridoxine on a high-fat diet-induced reduction of cell proliferation and neuroblast differentiation depend on cyclic adenosine monophosphate response element binding protein in the mouse dentate gyrus.

PubMed

Yoo, Dae Young; Kim, Woosuk; Yoo, Ki-Yeon; Nam, Sung Min; Chung, Jin Young; Yoon, Yeo Sung; Won, Moo-Ho; Hwang, In Koo

2012-08-01

In this study, we challenged pyridoxine to mice fed a high-fat diet (HFD) and investigated the effects of pyridoxine on HFD-induced phenotypes such as blood glucose, reduction of cell proliferation and neuroblast differentiation in the dentate gyrus using Ki67 and doublecortin (DCX), respectively. Mice were fed a commercially available low-fat diet (LFD) as control diet or HFD (60% fat) for 8 weeks. After 5 weeks of LFD or HFD treatment, 350 mg/kg pyridoxine was administered for 3 weeks. The administration of pyridoxine significantly decreased body weight in the HFD-treated group. In addition, there were no significant differences in hepatic histology and pancreatic insulin-immunoreactive (-ir) and glucagon-ir cells of the HFD-treated group after pyridoxine treatment. In the HFD-fed group, Ki67-positive nuclei and DCX-ir neuroblasts were significantly decreased in the dentate gyrus compared with those in the LFD-fed mice. However, the administration of pyridoxine significantly increased Ki67-positive nuclei and DCX-ir neuroblasts in the dentate gyrus in both LFD- and HFD-fed mice. In addition, the administration of pyridoxine significantly increased the protein levels of glutamic acid decarboxylase 67 (GAD67) and brain-derived neurotrophic factor (BDNF) and the immunoreactivity of phosphorylated cyclic AMP response element binding protein (pCREB) compared with the vehicle-treated LFD- and HFD-fed mice. In contrast, the administration of pyridoxine significantly decreased HFD-induced malondialdehyde (MDA) levels in the hippocampus. These results showed that pyridoxine supplement reduced the HFD-induced reduction of cell proliferation and neuroblast differentiation in the dentate gyrus via controlling the levels of GAD67, pCREB, BDNF, and MDA. Copyright © 2012 Wiley Periodicals, Inc.

Deficiency of the NR4A Orphan Nuclear Receptor NOR1 attenuates Neointima Formation Following Vascular Injury

PubMed Central

Nomiyama, Takashi; Zhao, Yue; Gizard, Florence; Findeisen, Hannes M.; Heywood, Elizabeth B.; Jones, Karrie L.; Conneely, Orla M.; Bruemmer, Dennis

2009-01-01

Background The neuron-derived orphan receptor-1 (NOR1) belongs to the evolutionary highly conserved and most ancient NR4A subfamily of the nuclear hormone receptor superfamily. Members of this subfamily function as early response genes regulating key cellular processes including proliferation, differentiation, and survival. Although NOR1 has previously been demonstrated to be required for smooth muscle cell (SMC) proliferation in vitro, the role of this nuclear receptor for the proliferative response underlying neointima formation and target genes trans-activated by NOR1 remain to be defined. Methods and Results Using a model of guide wire-induced arterial injury, we demonstrate decreased neointima formation in NOR1-/- mice compared to wildtype mice. In vitro, NOR1-deficient SMC exhibit decreased proliferation due to a G1→S phase arrest of the cell cycle and increased apoptosis in response to serum deprivation. NOR1-deficiency alters phosphorylation of the retinoblastoma protein by preventing mitogen-induced cyclin D1 and D2 expression. Conversely, overexpression of NOR1 induces cyclin D1 expression and the transcriptional activity of the cyclin D1 promoter in transient reporter assays. Gel shift and chromatin immunoprecipitation assays identified a putative response element for NR4A receptors in the cyclin D1 promoter, to which NOR1 is recruited in response to mitogenic stimulation. Finally, we provide evidence that these observations are applicable in vivo by demonstrating decreased cyclin D1 expression during neointima formation in NOR1-deficient mice. Conclusions These experiments characterize cyclin D1 as a NOR1-regulated target gene in SMC and demonstrate that NOR1 deficiency decreases neointima formation in response to vascular injury. PMID:19153266

The splicing activator DAZAP1 integrates splicing control into MEK/Erk-regulated cell proliferation and migration

NASA Astrophysics Data System (ADS)

Choudhury, Rajarshi; Roy, Sreerupa Ghose; Tsai, Yihsuan S.; Tripathy, Ashutosh; Graves, Lee M.; Wang, Zefeng

2014-01-01

Alternative splicing of pre-messenger RNA (mRNA) is a critical stage of gene regulation in response to environmental stimuli. Here we show that DAZAP1, an RNA-binding protein involved in mammalian development and spermatogenesis, promotes inclusion of weak exons through specific recognition of diverse cis-elements. The carboxy-terminal proline-rich domain of DAZAP1 interacts with and neutralizes general splicing inhibitors, and is sufficient to activate splicing when recruited to pre-mRNA. This domain is phosphorylated by the MEK/Erk (extracellular signal-regulated protein kinase) pathway and this modification is essential for the splicing regulatory activity and the nuclear/cytoplasmic translocation of DAZAP1. Using mRNA-seq, we identify endogenous splicing events regulated by DAZAP1, many of which are involved in maintaining cell growth. Knockdown or over-expression of DAZAP1 causes a cell proliferation defect. Taken together, these studies reveal a molecular mechanism that integrates splicing control into MEK/Erk-regulated cell proliferation.

The splicing activator DAZAP1 integrates splicing control into MEK/Erk regulated cell proliferation and migration

PubMed Central

Choudhury, Rajarshi; Roy, Sreerupa Ghose; Tsai, Yihsuan S.; Tripathy, Ashutosh; Graves, Lee M.; Wang, Zefeng

2014-01-01

Alternative splicing of pre-mRNA is a critical stage of gene regulation in response to environmental stimuli. Here we show that DAZAP1, an RNA binding protein involved in mammalian development and spermatogenesis, promotes inclusion of weak exons through specific recognition of diverse cis-elements. The C-terminal proline-rich domain of DAZAP1 interacts with and neutralizes general splicing inhibitors, and is sufficient to activate splicing when recruited to pre-mRNA. This domain is phosphorylated by the MEK/Erk pathway and this modification is essential for the splicing regulatory activity and the nuclear/cytoplasmic translocation of DAZAP1. Using mRNA-seq we identify endogenous splicing events regulated by DAZAP1, many of which are involved in maintaining cell growth. Knockdown or over-expression of DAZAP1 causes a cell proliferation defect. Taken together, these studies reveal a molecular mechanism that integrates splicing control into MEK/Erk regulated cell proliferation. PMID:24452013

Exogenous ghrelin regulates proliferation and apoptosis in the hypotrophic gut mucosa of the rat.

PubMed

de Segura, Ignacio A Gómez; Vallejo-Cremades, María Teresa; Lomas, Jesús; Sánchez, Miriam F; Caballero, María Isabel; Largo, Carlota; De Miguel, Enrique

2010-04-01

Ghrelin is the natural endogenous ligand for growth hormone secretagogue receptors. This peptide regulates energy homeostasis and expenditure and is a potential link between gut absorptive function and growth. We hypothesized that ghrelin may induce a proliferative and antiapoptotic action promoting the recovery of the hypotrophic gut mucosa. Therefore, the aim of the study was to determine the action of exogenous ghrelin following gut mucosal hypotrophia in rats fed an elemental diet. An elemental diet provides readily absorbable simple nutrients and is usually given to patients with absorptive dysfunction. Male Wistar rats (n = 48) were fed the elemental diet for one week to induce mucosal hypotrophy and then treated for another week with systemic ghrelin and pair-fed with either a normoproteic or hyperproteic isocaloric liquid diet. Another group received a standard diet instead of the elemental diet and served as control (normotrophy). The elemental diet induced intestinal hypotrophia characterized by decreased proliferation in the ileum and increased apoptosis in jejunum and ileum. Ghrelin administration restored normal levels of proliferation in the ileum and apoptosis in the jejunum, with partial apoptosis restoration in the ileum. Ghrelin levels in plasma and fundus were increased in all groups, although the highest levels were found in rats treated with exogenous ghrelin. Ghrelin administration has a positive effect in the hypotrophic gut, regulating both proliferation and apoptosis towards a physiological balance counteracting the negative changes induced by an elemental diet in the intestines.

Androgen receptor stimulates bone sialoprotein (BSP) gene transcription via cAMP response element and activator protein 1/glucocorticoid response elements.

PubMed

Takai, Hideki; Nakayama, Youhei; Kim, Dong-Soon; Arai, Masato; Araki, Shouta; Mezawa, Masaru; Nakajima, Yu; Kato, Naoko; Masunaga, Hiroshi; Ogata, Yorimasa

2007-09-01

Bone sialoprotein (BSP) is an early marker of osteoblast differentiation. Androgens are steroid hormones that are essential for skeletal development. The androgen receptor (AR) is a transcription factor and a member of the steroid receptor superfamily that plays an important role in male sexual differentiation and prostate cell proliferation. To determine the molecular mechanism involved in the stimulation of bone formation, we have analyzed the effects of androgens and AR effects on BSP gene transcription. AR protein levels were increased after AR overexpression in ROS17/2.8 cells. BSP mRNA levels were increased by AR overexpression. However, the endogenous and overexpressed BSP mRNA levels were not changed by DHT (10(-8) M, 24 h). Whereas luciferase (LUC) activities in all constructs, including a short construct (nts -116 to +60), were increased by AR overexpression, the basal and LUC activities enhanced by AR overexpression were not induced by DHT (10(-8)M, 24 h). The effect of AR overexpression was abrogated by 2 bp mutations in either the cAMP response element (CRE) or activator protein 1 (AP1)/glucocorticoid response element (GRE). Gel shift analyses showed that AR overexpression increased binding to the CRE and AP1/GRE elements. Notably, the CRE-protein complexes were supershifted by phospho-CREB antibody, and CREB, c-Fos, c-Jun, and AR antibodies disrupted the complexes formation. The AP1/GRE-protein complexes were supershifted by c-Fos antibody and c-Jun, and AR antibodies disrupted the complexes formation. These studies demonstrate that AR stimulates BSP gene transcription by targeting the CRE and AP1/GRE elements in the promoter of the rat BSP gene.

The cis decoy against the estrogen response element suppresses breast cancer cells via target disrupting c-fos not mitogen-activated protein kinase activity.

PubMed

Wang, Li Hua; Yang, Xiao Yi; Zhang, Xiaohu; Mihalic, Kelly; Xiao, Weihua; Farrar, William L

2003-05-01

Breast cancer, the most common malignancy in women, has been demonstrated to be associated with the steroid hormone estrogen and its receptor (ER), a ligand-activated transcription factor. Therefore, we developed a phosphorothiolate cis-element decoy against the estrogen response element (ERE decoy) to target disruption of ER DNA binding and transcriptional activity. Here, we showed that the ERE decoy potently ablated the 17beta-estrogen-inducible cell proliferation and induced apoptosis of human breast carcinoma cells by functionally affecting expression of c-fos gene and AP-1 luciferase gene reporter activity. Specificity of the decoy was demonstrated by its ability to directly block ER binding to a cis-element probe and transactivation. Moreover, the decoy failed to inhibit ER-mediated mitogen-activated protein kinase signaling pathways and cell growth of ER-negative breast cancer cells. Taken together, these data suggest that estrogen-mediated cell growth of breast cancer cells can be preferentially restricted via targeted disruption of ER at the level of DNA binding by a novel and specific decoy strategy applied to steroid nuclear receptors.

Roles of calpain-calpastatin system (CCS) in human T cell activation.

PubMed

Mikosik, Anna; Jasiulewicz, Aleksandra; Daca, Agnieszka; Henc, Izabella; Frąckowiak, Joanna E; Ruckemann-Dziurdzińska, Katarzyna; Foerster, Jerzy; Le Page, Aurelie; Bryl, Ewa; Fulop, Tamas; Witkowski, Jacek M

2016-11-22

The immune response is determined by the speed of the T cell reaction to antigens assured by a state of readiness for proliferation and cytokine secretion. Proliferation, apoptosis and motion of many cell types are controlled by cytoplasmic proteases - µ- and m-calpain - and their inhibitor calpastatin, together forming the "calpain-calpastatin system" (CCS), assumed to modify their targets only upon activation-dependent cytoplasmic Ca2+ increase. Contrastingly to this notion, using quantitative real time PCR and semiquantitative flow cytometry respectively, we show here that the CCS genes are constitutively expressed, and that both calpains are constitutively active in resting, circulating human CD4+ and CD8+ lymphocytes. Furthermore, we demonstrate that calpain inhibition in the resting T cells prevents them from proliferation in vitro and greatly reduces secretion of multiple cytokines. The mechanistic reason for these effects of calpain inhibition on T cell functions might be the demonstrated significant reduction of the expression of active (phosphorylated) upstream signalling molecules, including the phospholipase C gamma, p56Lck and NFκB, in the inhibitor-treated cells. Thus, we propose that the constitutive, self-regulatory calpain-calpastatin system activity in resting human T cells is a necessary, controlling element of their readiness for complex and effective response to antigenic challenge.

Histamine acting on H1 receptor promotes inhibition of proliferation via PLC, RAC, and JNK-dependent pathways

DOE Office of Scientific and Technical Information (OSTI.GOV)

Notcovich, Cintia; Laboratorio de Farmacologia de Receptores, Catedra de Quimica Medicinal, Departamento de Farmacologia, Facultad de Farmacia y Bioquimica, Universidad de Buenos Aires; Diez, Federico

2010-02-01

It is well established that histamine modulates cell proliferation through the activation of the histamine H1 receptor (H1R), a G protein-coupled receptor (GPCR) that is known to couple to phospholipase C (PLC) activation via Gq. In the present study, we aimed to determine whether H1R activation modulates Rho GTPases, well-known effectors of Gq/G{sub 11}-coupled receptors, and whether such modulation influences cell proliferation. Experiments were carried out in CHO cells stably expressing H1R (CHO-H1R). By using pull-down assays, we found that both histamine and a selective H1R agonist activated Rac and RhoA in a time- and dose-dependent manner without significant changesmore » in the activation of Cdc42. Histamine response was abolished by the H1R antagonist mepyramine, RGS2 and the PLC inhibitor U73122, suggesting that Rac and RhoA activation is mediated by H1R via Gq coupling to PLC stimulation. Histamine caused a marked activation of serum response factor activity via the H1R, as determined with a serum-responsive element (SRE) luciferase reporter, and this response was inhibited by RhoA inactivation with C3 toxin. Histamine also caused a significant activation of JNK which was inhibited by expression of the Rac-GAP {beta}2-chimaerin. On the other hand, H1R-induced ERK1/2 activation was inhibited by U73122 but not affected by C3 or {beta}2-chimaerin, suggesting that ERK1/2 activation was dependent on PLC and independent of RhoA or Rac. [{sup 3}H]-Thymidine incorporation assays showed that both histamine and the H1R agonist inhibited cell proliferation in a dose-dependent manner and that the effect was independent of RhoA but partially dependent on JNK and Rac. Our results reveal that functional coupling of the H1R to Gq-PLC leads to the activation of RhoA and Rac small GTPases and suggest distinct roles for Rho GTPases in the control of cell proliferation by histamine.« less

Megalin/LRP2 Expression Is Induced by Peroxisome Proliferator-Activated Receptor -Alpha and -Gamma: Implications for PPARs' Roles in Renal Function

PubMed Central

Cabezas, Felipe; Lagos, Jonathan; Céspedes, Carlos; Vio, Carlos P.; Bronfman, Miguel; Marzolo, María-Paz

2011-01-01

Background Megalin is a large endocytic receptor with relevant functions during development and adult life. It is expressed at the apical surface of several epithelial cell types, including proximal tubule cells (PTCs) in the kidney, where it internalizes apolipoproteins, vitamins and hormones with their corresponding carrier proteins and signaling molecules. Despite the important physiological roles of megalin little is known about the regulation of its expression. By analyzing the human megalin promoter, we found three response elements for the peroxisomal proliferator-activated receptor (PPAR). The objective of this study was to test whether megalin expression is regulated by the PPARs. Methodology/Principal Findings Treatment of epithelial cell lines with PPARα or PPARγ ligands increased megalin mRNA and protein expression. The stimulation of megalin mRNA expression was blocked by the addition of specific PPARα or PPARγ antagonists. Furthermore, PPAR bound to three PPAR response elements located in the megalin promoter, as shown by EMSA, and PPARα and its agonist activated a luciferase construct containing a portion of the megalin promoter and the first response element. Accordingly, the activation of PPARα and PPARγ enhanced megalin expression in mouse kidney. As previously observed, high concentrations of bovine serum albumin (BSA) decreased megalin in PTCs in vitro; however, PTCs pretreated with PPARα and PPARγ agonists avoided this BSA-mediated reduction of megalin expression. Finally, we found that megalin expression was significantly inhibited in the PTCs of rats that were injected with BSA to induce tubulointerstitial damage and proteinuria. Treatment of these rats with PPARγ agonists counteracted the reduction in megalin expression and the proteinuria induced by BSA. Conclusions PPARα/γ and their agonists positively control megalin expression. This regulation could have an important impact on several megalin-mediated physiological processes and on pathophysiologies such as chronic kidney disease associated with diabetes and hypertension, in which megalin expression is impaired. PMID:21311715

Transposable Element Proliferation and Genome Expansion Are Rare in Contemporary Sunflower Hybrid Populations Despite Widespread Transcriptional Activity of LTR Retrotransposons

PubMed Central

Kawakami, Takeshi; Dhakal, Preeti; Katterhenry, Angela N.; Heatherington, Chelsea A.; Ungerer, Mark C.

2011-01-01

Hybridization is a natural phenomenon that has been linked in several organismal groups to transposable element derepression and copy number amplification. A noteworthy example involves three diploid annual sunflower species from North America that have arisen via ancient hybridization between the same two parental taxa, Helianthus annuus and H. petiolaris. The genomes of the hybrid species have undergone large-scale increases in genome size attributable to long terminal repeat (LTR) retrotransposon proliferation. The parental species that gave rise to the hybrid taxa are widely distributed, often sympatric, and contemporary hybridization between them is common. Natural H. annuus × H. petiolaris hybrid populations likely served as source populations from which the hybrid species arose and, as such, represent excellent natural experiments for examining the potential role of hybridization in transposable element derepression and proliferation in this group. In the current report, we examine multiple H. annuus × H. petiolaris hybrid populations for evidence of genome expansion, LTR retrotransposon copy number increases, and LTR retrotransposon transcriptional activity. We demonstrate that genome expansion and LTR retrotransposon proliferation are rare in contemporary hybrid populations, despite independent proliferation events that took place in the genomes of the ancient hybrid species. Interestingly, LTR retrotransposon lineages that proliferated in the hybrid species genomes remain transcriptionally active in hybrid and nonhybrid genotypes across the entire sampling area. The finding of transcriptional activity but not copy number increases in hybrid genotypes suggests that proliferation and genome expansion in contemporary hybrid populations may be mitigated by posttranscriptional mechanisms of repression. PMID:21282712

The ERK/CREB pathway is involved in the c-Ski expression induced by low TGF-β1 concentrations during primary fibroblast proliferation.

PubMed

Li, Ping; Liu, Ping; Peng, Yan; Zhang, Zhuo-Hang; Li, Xiao-Ming; Xiong, Ren-Ping; Chen, Xing; Zhao, Yan; Ning, Ya-Lei; Yang, Nan; Zhang, Bo; Zhou, Yuan-Guo

2018-06-27

Increasing evidence has suggested that bidirectional regulation of cell proliferation is one important effect of TGF-β1 in wound healing. Increased c-Ski expression plays a role in promoting fibroblast proliferation at low TGF-β1 concentrations, but the mechanism by which low TGF-β1 concentrations regulate c-Ski levels remains unclear. In this study, the proliferation of rat primary fibroblasts was assessed with an ELISA BrdU kit. The mRNA and protein expression and phosphorylation levels of corresponding factors were measured by RT-qPCR, immunohistochemistry or Western blotting. We first found that low TGF-β1 concentrations not only promoted c-Ski mRNA and protein expression in rat primary fibroblasts but also increased the phosphorylation levels of Extracellular Signal-Regulated Kinases (ERK) and cAMP response element binding (CREB) protein. An ERK kinase (mitogen-activated protein kinase kinase, MEK) inhibitor significantly inhibited ERK1/2 phosphorylation levels, markedly reducing c-Ski expression and CREB phosphorylation levels and abrogating the growth-promoting effect of low TGF-β1 concentrations. At the same time, Smad2/3 phosphorylation levels were not significantly changed. Taken together, these results suggest that the increased cell proliferation induced by low TGF-β1 concentrations mediates c-Ski expression potentially through the ERK/CREB pathway rather than through the classic TGF-β1/Smad pathway.

Platelet-released growth factors can accelerate tenocyte proliferation and activate the anti-oxidant response element.

PubMed

Tohidnezhad, M; Varoga, D; Wruck, C J; Brandenburg, L O; Seekamp, A; Shakibaei, M; Sönmez, T T; Pufe, Thomas; Lippross, S

2011-05-01

Little is know about the pathophysiology of acute and degenerative tendon injuries. Although most lesions are uncomplicated, treatment is long and unsatisfactory in a considerable number of cases. Besides the common growth factors that were shown to be relevant for tendon integrity more recently protection against oxidative stress was shown to promote tendon healing. To improve tendon regeneration, many have advocated the use of platelet-rich plasma (PRP), a thrombocyte concentrate that can serve as an autologous source of growth factors. In this study, we investigated the effect of platelet-released growth factors (PRGF) on tenocytes. Tenocytes were isolated from the Achilles tendon of postnatal rats. Tenocyte cell cultures were stimulated with PRGF. We used a CyQuant assay and WST assay to analyse tendon cell growth and viability in different concentrations of PRGF. Migration and proliferation of cells grown in PRGF were assessed by a scratch test. A dual-luciferase assay was used to demonstrate the activation of the anti-oxidant response element (ARE) in tenocytes. A positive effect of PRGF could be shown on tendon cell growth and migratory capacity. PRGF activated the Nrf2-ARE pathway in a dose-dependent manner. Here, we provide evidence of a biological effect of PRGF on tenocytes by the promotion of tenocyte growth and activation of the Nrf2-ARE pathway. This is a novel aspect of the action of platelet concentrates on tendon growth.

Somatotroph hypoplasia and dwarfism in transgenic mice expressing a non-phosphorylatable CREB mutant.

PubMed

Struthers, R S; Vale, W W; Arias, C; Sawchenko, P E; Montminy, M R

1991-04-18

Most of the transcriptional effects of cyclic AMP are mediated by the cAMP response element binding protein (CREB). After activation of cAMP-dependent protein kinase A, the catalytic subunits of this enzyme apparently mediate the phosphorylation and activation of CREB. As cAMP serves as a mitogenic signal for anterior pituitary somatotrophic cells, we investigated whether CREB similarly regulates proliferation of these cells. We prepared transgenic mice expressing a transcriptionally inactive mutant of CREB (CREBM1), which cannot be phosphorylated, in cells of the anterior pituitary. If CREB activity is required for proliferation, the overexpressed mutant protein would effectively compete with wild-type CREB activity and thereby block the response to cAMP. As predicted, the CREBM1 transgenic mice exhibited a dwarf phenotype with atrophied pituitary glands markedly deficient in somatotroph but not other cell types. We conclude that transcriptional activation of CREB is necessary for the normal development of a highly restricted cell type, and that environmental cues, possibly provided by the hypothalamic growth hormone-releasing factor, are necessary for population of the pituitary by somatotrophic cells.

Transcriptional Regulation of S Phase Kinase-associated Protein 2 by NR4A Orphan Nuclear Receptor NOR1 in Vascular Smooth Muscle Cells*

PubMed Central

Gizard, Florence; Zhao, Yue; Findeisen, Hannes M.; Qing, Hua; Cohn, Dianne; Heywood, Elizabeth B.; Jones, Karrie L.; Nomiyama, Takashi; Bruemmer, Dennis

2011-01-01

Members of the NR4A subgroup of the nuclear hormone receptor superfamily have emerged as key transcriptional regulators of proliferation and inflammation. NOR1 constitutes a ligand-independent transcription factor of this subgroup and induces cell proliferation; however, the transcriptional mechanisms underlying this mitogenic role remain to be defined. Here, we demonstrate that the F-box protein SKP2 (S phase kinase-associated protein 2), the substrate-specific receptor of the ubiquitin ligase responsible for the degradation of p27KIP1 through the proteasome pathway, constitutes a direct transcriptional target for NOR1. Mitogen-induced Skp2 expression is silenced in vascular smooth muscle cells (VSMC) isolated from Nor1-deficient mice or transfected with Nor1 siRNA. Conversely, adenovirus-mediated overexpression of NOR1 induces Skp2 expression in VSMC and decreases protein abundance of its target p27. Transient transfection experiments establish that NOR1 transactivates the Skp2 promoter through a nerve growth factor-induced clone B response element (NBRE). Electrophoretic mobility shift and chromatin immunoprecipitation assays further revealed that NOR1 is recruited to this NBRE site in the Skp2 promoter in response to mitogenic stimulation. In vivo Skp2 expression is increased during the proliferative response underlying neointima formation, and this transcriptional induction depends on the expression of NOR1. Finally, we demonstrate that overexpression of Skp2 rescues the proliferative arrest of Nor1-deficient VSMC. Collectively, these results characterize Skp2 as a novel NOR1-regulated target gene and detail a previously unrecognized transcriptional cascade regulating mitogen-induced VSMC proliferation. PMID:21868379

Oxidative DNA damage and mammary cell proliferation by alcohol-derived salsolinol.

PubMed

Murata, Mariko; Midorikawa, Kaoru; Kawanishi, Shosuke

2013-10-21

Drinking alcohol is a risk factor for breast cancer. Salsolinol (SAL) is endogenously formed by a condensation reaction of dopamine with acetaldehyde, a major ethanol metabolite, and SAL is detected in blood and urine after alcohol intake. We investigated the possibility that SAL can participate in tumor initiation and promotion by causing DNA damage and cell proliferation, leading to alcohol-associated mammary carcinogenesis. SAL caused oxidative DNA damage including 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), in the presence of transition metal ions, such as Cu(II) and Fe(III)EDTA. Inhibitory effects of scavengers on SAL-induced DNA damage and the electron spin resonance study indicated the involvement of H₂O₂, which is generated via the SAL radical. Experiments on scavengers and site specificity of DNA damage suggested ·OH generation via a Fenton reaction and copper-peroxide complexes in the presence of Fe(III)EDTA and Cu(II), respectively. SAL significantly increased 8-oxodG formation in normal mammary epithelial MCF-10A cells. In addition, SAL induced cell proliferation in estrogen receptor (ER)-negative MCF-10A cells, and the proliferation was inhibited by an antioxidant N-acetylcysteine and an epidermal growth factor receptor (EGFR) inhibitor AG1478, suggesting that reactive oxygen species may participate in the proliferation of MCF-10A cells via EGFR activation. Furthermore, SAL induced proliferation in estrogen-sensitive breast cancer MCF-7 cells, and a surface plasmon resonance sensor revealed that SAL significantly increased the binding activity of ERα to the estrogen response element but not ERβ. In conclusion, SAL-induced DNA damage and cell proliferation may play a role in tumor initiation and promotion of multistage mammary carcinogenesis in relation to drinking alcohol.

Lysophosphatidic Acid Up-Regulates Hexokinase II and Glycolysis to Promote Proliferation of Ovarian Cancer Cells1

PubMed Central

Mukherjee, Abir; Ma, Yibao; Yuan, Fang; Gong, Yongling; Fang, Zhenyu; Mohamed, Esraa M.; Berrios, Erika; Shao, Huanjie; Fang, Xianjun

2015-01-01

Lysophosphatidic acid (LPA), a blood-borne lipid mediator, is present in elevated concentrations in ascites of ovarian cancer patients and other malignant effusions. LPA is a potent mitogen in cancer cells. The mechanism linking LPA signal to cancer cell proliferation is not well understood. Little is known about whether LPA affects glucose metabolism to accommodate rapid proliferation of cancer cells. Here we describe that in ovarian cancer cells, LPA enhances glycolytic rate and lactate efflux. A real time PCR-based miniarray showed that hexokinase II (HK2) was the most dramatically induced glycolytic gene to promote glycolysis in LPA-treated cells. Analysis of the human HK2 gene promoter identified the sterol regulatory element-binding protein as the primary mediator of LPA-induced HK2 transcription. The effects of LPA on HK2 and glycolysis rely on LPA2, an LPA receptor subtype overexpressed in ovarian cancer and many other malignancies. We further examined the general role of growth factor-induced glycolysis in cell proliferation. Like LPA, epidermal growth factor (EGF) elicited robust glycolytic and proliferative responses in ovarian cancer cells. Insulin-like growth factor 1 (IGF-1) and insulin, however, potently stimulated cell proliferation but only modestly induced glycolysis. Consistent with their differential effects on glycolysis, LPA and EGF-dependent cell proliferation was highly sensitive to glycolytic inhibition while the growth-promoting effect of IGF-1 or insulin was more resistant. These results indicate that LPA- and EGF-induced cell proliferation selectively involves up-regulation of HK2 and glycolytic metabolism. The work is the first to implicate LPA signaling in promotion of glucose metabolism in cancer cells. PMID:26476080

Strain activation of bovine aortic smooth muscle cell proliferation and alignment: study of strain dependency and the role of protein kinase A and C signaling pathways

NASA Technical Reports Server (NTRS)

Mills, I.; Cohen, C. R.; Kamal, K.; Li, G.; Shin, T.; Du, W.; Sumpio, B. E.

1997-01-01

Smooth muscle cell (SMC) phenotype can be altered by physical forces as demonstrated by cyclic strain-induced changes in proliferation, orientation, and secretion of macromolecules. However, the magnitude of strain required and the intracellular coupling pathways remain ill defined. To examine the strain requirements for SMC proliferation, we selectively seeded bovine aortic SMC either on the center or periphery of silastic membranes which were deformed with 150 mm Hg vacuum (0-7% center; 7-24% periphery). SMC located in either the center or peripheral regions showed enhanced proliferation compared to cells grown under the absence of cyclic strain. Moreover, SMC located in the center region demonstrated significantly (P < 0.005) greater proliferation as compared to those in the periphery. In contrast, SMC exposed to high strain (7-24%) demonstrated alignment perpendicular to the strain gradient, whereas SMC in the center (0-7%) remained aligned randomly. To determine the mechanisms of these phenomena, we examined the effect of cyclic strain on bovine aortic SMC signaling pathways. We observed strain-induced stimulation of the cyclic AMP pathway including adenylate cyclase activity and cyclic AMP accumulation. In addition, exposure of SMC to cyclic strain caused a significant increase in protein kinase C (PKC) activity and enzyme translocation from the cytosol to a particulate fraction. Further study was conducted to examine the effect of strain magnitude on signaling, particularly protein kinase A (PKA) activity as well as cAMP response element (CRE) binding protein levels. We observed significantly (P < 0.05) greater PKA activity and CRE binding protein levels in SMC located in the center as compared to the peripheral region. However, inhibition of PKA (with 10 microM Rp-cAMP) or PKC (with 5-20 ng/ml staurosporine) failed to alter either the strain-induced increase in SMC proliferation or alignment. These data characterize the strain determinants for activation of SMC proliferation and alignment. Although strain activated both the AC/cAMP/PKA and the PKC pathways in SMC, singular inhibition of PKA and PKC failed to prevent strain-induced alignment and proliferation, suggesting either their lack of involvement or the multifactorial nature of these responses.

Utilization of DR1 as true RARE in regulating the Ssm, a novel retinoic acid-target gene in the mouse testis.

PubMed

Han, Kyuyong; Song, Haengseok; Moon, Irene; Augustin, Robert; Moley, Kelle; Rogers, Melissa; Lim, Hyunjung

2007-03-01

Various nuclear receptors form dimers to activate target genes via specific response elements located within promoters or enhancers. Retinoid X receptor (RXR) serves as a dimerization partner for many nuclear receptors including retinoic acid receptor (RAR) and peroxisome proliferator-activated receptor (PPAR). Dimers show differential preference towards directly repeated response elements with 1-5 nucleotide spacing, and direct repeat 1 (DR1) is a promiscuous element which recruits RAR/RXR, RXR/RXR, and PPAR/RXR in vitro. In the present investigation, we report identification of a novel RAR/RXR target gene which is regulated by DR1s in the promoter region. This gene, namely spermatocyte-specific marker (Ssm), recruits all the three combinations of nuclear receptors in vitro, but in vivo regulation is observed by trans-retinoic acid-activated RAR/RXR dimer. Indeed, chromatin immunoprecipitation experiment demonstrates binding of RARbeta and RXRalpha in the promoter region of the Ssm. Interestingly, expression of Ssm is almost exclusively observed in spermatocytes in the adult mouse testis, where RA signaling is known to regulate developmental program of male germ cells. The results show that Ssm is a RAR/RXR target gene uniquely using DR1 and exhibits stage-specific expression in the mouse testis with potential function in later stages of spermatogenesis. This finding exemplifies usage of DR1s as retinoic acid response element (RARE) under a specific in vivo context.

Mobile genetic element proliferation and gene inactivation impact over the genome structure and metabolic capabilities of Sodalis glossinidius, the secondary endosymbiont of tsetse flies

PubMed Central

2010-01-01

Background Genome reduction is a common evolutionary process in symbiotic and pathogenic bacteria. This process has been extensively characterized in bacterial endosymbionts of insects, where primary mutualistic bacteria represent the most extreme cases of genome reduction consequence of a massive process of gene inactivation and loss during their evolution from free-living ancestors. Sodalis glossinidius, the secondary endosymbiont of tsetse flies, contains one of the few complete genomes of bacteria at the very beginning of the symbiotic association, allowing to evaluate the relative impact of mobile genetic element proliferation and gene inactivation over the structure and functional capabilities of this bacterial endosymbiont during the transition to a host dependent lifestyle. Results A detailed characterization of mobile genetic elements and pseudogenes reveals a massive presence of different types of prophage elements together with five different families of IS elements that have proliferated across the genome of Sodalis glossinidius at different levels. In addition, a detailed survey of intergenic regions allowed the characterization of 1501 pseudogenes, a much higher number than the 972 pseudogenes described in the original annotation. Pseudogene structure reveals a minor impact of mobile genetic element proliferation in the process of gene inactivation, with most of pseudogenes originated by multiple frameshift mutations and premature stop codons. The comparison of metabolic profiles of Sodalis glossinidius and tsetse fly primary endosymbiont Wiglesworthia glossinidia based on their whole gene and pseudogene repertoires revealed a novel case of pathway inactivation, the arginine biosynthesis, in Sodalis glossinidius together with a possible case of metabolic complementation with Wigglesworthia glossinidia for thiamine biosynthesis. Conclusions The complete re-analysis of the genome sequence of Sodalis glossinidius reveals novel insights in the evolutionary transition from a free-living ancestor to a host-dependent lifestyle, with a massive proliferation of mobile genetic elements mainly of phage origin although with minor impact in the process of gene inactivation that is taking place in this bacterial genome. The metabolic analysis of the whole endosymbiotic consortia of tsetse flies have revealed a possible phenomenon of metabolic complementation between primary and secondary endosymbionts that can contribute to explain the co-existence of both bacterial endosymbionts in the context of the tsetse host. PMID:20649993

Human hnRNP protein A1 gene expression. Structural and functional characterization of the promoter.

PubMed

Biamonti, G; Bassi, M T; Cartegni, L; Mechta, F; Buvoli, M; Cobianchi, F; Riva, S

1993-03-05

hnRNP protein A1 (34 kDa, pl 9.5) is a prominent member of the family of proteins (hnRNP proteins) that associate with the nascent transcripts of RNA polymerase II and that accompany the hnRNA through the maturation process and the export to the cytoplasm. New evidence suggests an active and specific role for some of these proteins, including protein A1, in splicing and transport. Contrary to the other hnRNP proteins, the intracellular level of protein A1 was reported to change as a function of proliferation state and cell type. In this work we analyse the A1 gene expression in different cells under different growth and differentiation conditions. Proliferation dependent expression was observed in lymphocytes and fibroblasts while purified neurons express high A1 mRNA levels both in the proliferative (before birth) and in the quiescent (after birth) state. Transformed cell lines exhibit very high (proliferation independent) A1 mRNA levels compared to differentiated tissues. A structural and functional characterization of the A1 gene promoter was carried out by means of DNase I footprinting and CAT assays. The observed promoter features can account for both elevated and regulated mRNA transcription. At least 12 control elements are contained in the 734 nucleotides upstream of the transcription start site. Assays with the deleted and/or mutated promoter indicate a co-operation of multiple transcriptional elements, distributed over the entire promoter, in determining the overall activity and the response to proliferative stimuli (serum).

A role for neuronal cAMP responsive-element binding (CREB)-1 in brain responses to calorie restriction

PubMed Central

Fusco, Salvatore; Ripoli, Cristian; Podda, Maria Vittoria; Ranieri, Sofia Chiatamone; Leone, Lucia; Toietta, Gabriele; McBurney, Michael W.; Schütz, Günther; Riccio, Antonella; Grassi, Claudio; Galeotti, Tommaso; Pani, Giovambattista

2012-01-01

Calorie restriction delays brain senescence and prevents neurodegeneration, but critical regulators of these beneficial responses other than the NAD+-dependent histone deacetylase Sirtuin-1 (Sirt-1) are unknown. We report that effects of calorie restriction on neuronal plasticity, memory and social behavior are abolished in mice lacking cAMP responsive-element binding (CREB)-1 in the forebrain. Moreover, CREB deficiency drastically reduces the expression of Sirt-1 and the induction of genes relevant to neuronal metabolism and survival in the cortex and hippocampus of dietary-restricted animals. Biochemical studies reveal a complex interplay between CREB and Sirt-1: CREB directly regulates the transcription of the sirtuin in neuronal cells by binding to Sirt-1 chromatin; Sirt-1, in turn, is recruited by CREB to DNA and promotes CREB-dependent expression of target gene peroxisome proliferator-activated receptor-γ coactivator-1α and neuronal NO Synthase. Accordingly, expression of these CREB targets is markedly reduced in the brain of Sirt KO mice that are, like CREB-deficient mice, poorly responsive to calorie restriction. Thus, the above circuitry, modulated by nutrient availability, links energy metabolism with neurotrophin signaling, participates in brain adaptation to nutrient restriction, and is potentially relevant to accelerated brain aging by overnutrition and diabetes. PMID:22190495

Thrombospondin-1 is a novel negative regulator of liver regeneration after partial hepatectomy through transforming growth factor-beta1 activation in mice.

PubMed

Hayashi, Hiromitsu; Sakai, Keiko; Baba, Hideo; Sakai, Takao

2012-05-01

The matricellular protein, thrombospondin-1 (TSP-1), is prominently expressed during tissue repair. TSP-1 binds to matrix components, proteases, cytokines, and growth factors and activates intracellular signals through its multiple domains. TSP-1 converts latent transforming growth factor-beta1 (TGF-β1) complexes into their biologically active form. TGF-β plays significant roles in cell-cycle regulation, modulation of differentiation, and induction of apoptosis. Although TGF-β1 is a major inhibitor of proliferation in cultured hepatocytes, the functional requirement of TGF-β1 during liver regeneration remains to be defined in vivo. We generated a TSP-1-deficient mouse model of a partial hepatectomy (PH) and explored TSP-1 induction, progression of liver regeneration, and TGF-β-mediated signaling during the repair process after hepatectomy. We show here that TSP-1-mediated TGF-β1 activation plays an important role in suppressing hepatocyte proliferation. TSP-1 expression was induced in endothelial cells (ECs) as an immediate early gene in response to PH. TSP-1 deficiency resulted in significantly reduced TGF-β/Smad signaling and accelerated hepatocyte proliferation through down-regulation of p21 protein expression. TSP-1 induced in ECs by reactive oxygen species (ROS) modulated TGF-β/Smad signaling and proliferation in hepatocytes in vitro, suggesting that the immediately and transiently produced ROS in the regenerating liver were the responsible factor for TSP-1 induction. We have identified TSP-1 as an inhibitory element in regulating liver regeneration by TGF-β1 activation. Our work defines TSP-1 as a novel immediate early gene that could be a potential therapeutic target to accelerate liver regeneration. Copyright © 2011 American Association for the Study of Liver Diseases.

Cord blood versus age 5 mononuclear cell proliferation on IgE and asthma

PubMed Central

2010-01-01

Background Fetal immune responses following exposure of mothers to allergens during pregnancy may influence the subsequent risk of childhood asthma. However, the association of allergen-induced cord blood mononuclear cell (CBMC) proliferation and cytokine production with later allergic immune responses and asthma has been controversial. Our objective was to compare indoor allergen-induced CBMC with age 5 peripheral blood mononuclear cell (PBMC) proliferation and determine which may be associated with age 5 allergic immune responses and asthma in an inner city cohort. Methods As part of an ongoing cohort study of the Columbia Center for Children's Environmental Health (CCCEH), CBMCs and age 5 PBMCs were cultured with cockroach, mouse, and dust mite protein extracts. CBMC proliferation and cytokine (IL-5 and IFN-γ) responses, and age 5 PBMC proliferation responses, were compared to anti-cockroach, anti-mouse, and anti-dust mite IgE levels, wheeze, cough, eczema and asthma. Results Correlations between CBMC and age 5 PBMC proliferation in response to cockroach, mouse, and dust mite antigens were nonsignificant. Cockroach-, mouse-, and dust mite-induced CBMC proliferation and cytokine responses were not associated with allergen-specific IgE at ages 2, 3, and 5, or with asthma and eczema at age 5. However, after adjusting for potential confounders, age 5 cockroach-induced PBMC proliferation was associated with anti-cockroach IgE, total IgE, and asthma (p < 0.05). Conclusion In contrast to allergen-induced CBMC proliferation, age 5 cockroach-induced PBMC proliferation was associated with age 5 specific and total IgE, and asthma, in an inner-city cohort where cockroach allergens are prevalent and exposure can be high. PMID:20684781

Morphologic study of the effect of iron on pseudocyst formation in Trichomonas vaginalis and its interaction with human epithelial cells.

PubMed

Dias-Lopes, Geovane; Saboia-Vahia, Leonardo; Margotti, Eliane Trindade; Fernandes, Nilma de Souza; Castro, Cássia Luana de Faria; Oliveira, Francisco Odencio; Peixoto, Juliana Figueiredo; Britto, Constança; Silva, Fernando Costa E; Cuervo, Patricia; Jesus, José Batista de

2017-10-01

Trichomonas vaginalis is the aetiological agent of human trichomoniasis, which is one of the most prevalent sexually transmitted diseases in humans. Iron is an important element for the survival of this parasite and the colonisation of the host urogenital tract. In this study, we investigated the effects of iron on parasite proliferation in the dynamics of pseudocyst formation and morphologically characterised iron depletion-induced pseudocysts. We performed structural and ultrastructural analyses using light microscopy, scanning electron microscopy and transmission electron microscopy. It was observed that iron depletion (i) interrupts the proliferation of T. vaginalis, (ii) induces morphological changes in typical multiplicative trophozoites to spherical non-proliferative, non-motile pseudocysts, and (iii) induces the arrest of cell division at different stages of the cell cycle; (iv) iron is the fundamental element for the maintenance of typical trophozoite morphology; (v) pseudocysts induced by iron depletion are viable and reversible forms; and, finally, (vi) we demonstrated that pseudocysts induced by iron depletion are able to interact with human epithelial cells maintaining their spherical forms. Together, these data suggest that pseudocysts could be induced as a response to iron nutritional stress and could have a potential role in the transmission and infection of T. vaginalis.

Morphologic study of the effect of iron on pseudocyst formation in Trichomonas vaginalis and its interaction with human epithelial cells

PubMed Central

Dias-Lopes, Geovane; Saboia-Vahia, Leonardo; Margotti, Eliane Trindade; Fernandes, Nilma de Souza; Castro, Cássia Luana de Faria; Oliveira, Francisco Odencio; Peixoto, Juliana Figueiredo; Britto, Constança; Silva, Fernando Costa e; Cuervo, Patricia; de Jesus, José Batista

2017-01-01

BACKGROUND Trichomonas vaginalis is the aetiological agent of human trichomoniasis, which is one of the most prevalent sexually transmitted diseases in humans. Iron is an important element for the survival of this parasite and the colonisation of the host urogenital tract. OBJECTIVES In this study, we investigated the effects of iron on parasite proliferation in the dynamics of pseudocyst formation and morphologically characterised iron depletion-induced pseudocysts. METHODS We performed structural and ultrastructural analyses using light microscopy, scanning electron microscopy and transmission electron microscopy. FINDINGS It was observed that iron depletion (i) interrupts the proliferation of T. vaginalis, (ii) induces morphological changes in typical multiplicative trophozoites to spherical non-proliferative, non-motile pseudocysts, and (iii) induces the arrest of cell division at different stages of the cell cycle; (iv) iron is the fundamental element for the maintenance of typical trophozoite morphology; (v) pseudocysts induced by iron depletion are viable and reversible forms; and, finally, (vi) we demonstrated that pseudocysts induced by iron depletion are able to interact with human epithelial cells maintaining their spherical forms. MAIN CONCLUSIONS Together, these data suggest that pseudocysts could be induced as a response to iron nutritional stress and could have a potential role in the transmission and infection of T. vaginalis. PMID:28953994

Glutamic acid ameliorates estrogen deficiency-induced menopausal-like symptoms in ovariectomized mice.

PubMed

Han, Na-Ra; Kim, Hee-Yun; Yang, Woong Mo; Jeong, Hyun-Ja; Kim, Hyung-Min

2015-09-01

Some amino acids are considered alternative therapies for improving menopausal symptoms. Glutamic acid (GA), which is abundant in meats, fish, and protein-rich plant foods, is known to be a neurotransmitter or precursor of γ-aminobutyric acid. Although it is unclear if GA functions in menopausal symptoms, we hypothesized that GA would attenuate estrogen deficiency-induced menopausal symptoms. The objective to test our hypothesis was to examine an estrogenic effect of GA in ovariectomized (OVX) mice, estrogen receptor (ER)-positive human osteoblast-like MG-63 cells, and ER-positive human breast cancer MCF-7 cells. The results demonstrated that administration with GA to mice suppressed body weight gain and vaginal atrophy when compared with the OVX mice. A microcomputed tomographic analysis of the trabecular bone showed increases in bone mineral density, trabecular number, and connectivity density as well as a significant decrease in total porosity of the OVX mice treated with GA. In addition, GA increased serum levels of alkaline phosphatase and estrogen compared with the OVX mice. Furthermore, GA induced proliferation and increased ER-β messenger RNA (mRNA) expression, estrogen response element (ERE) activity, extracellular signal-regulated kinase phosphorylation, and alkaline phosphatase activity in MG-63 cells. In MCF-7 cells, GA also increased proliferation, Ki-67 mRNA expression, ER-β mRNA expression, and ERE activity. Estrogen response element activity increased by GA was inhibited by an estrogen antagonist. Taken together, our data demonstrated that GA has estrogenic and osteogenic activities in OVX mice, MG-63 cells, and MCF-7 cells. Copyright © 2015 Elsevier Inc. All rights reserved.

Substance Abuse and America: Historical Perspective on the Federal Response to a Social Phenomenon

PubMed Central

Brown, Lawrence S.

1981-01-01

Much more often than is commonly given credit, factors other than a substance's therapeutic efficacy contribute to its affect on the individual experience, its own proliferation, and society's response. To explore these dynamics, American history is examined from the perspective of analyzing the development of substance abuse. Of the conclusions borne out by this historical perspective, foremost was that psychoactive substance use has been an element in the American social ecology from its earliest beginnings. The health professions have not always exhibited behavior in the interest of public health, and, most importantly, the federal response has often been plagued with outcomes that have been less desirable than many of the problems. This historical review supports the thesis that drug-seeking behavior and the response it elicits are in a constant state of flux and cannot be adequately appreciated in isolation from the sociocultural and historical contexts in which they occur. PMID:7017155

Direct exposure to mild heat promotes proliferation and neuronal differentiation of neural stem/progenitor cells in vitro

PubMed Central

Hossain, Md Emon; Katakura, Masanori; Sugimoto, Naotoshi; Mamun, Abdullah Al; Islam, Rafiad; Hashimoto, Michio; Shido, Osamu

2017-01-01

Heat acclimation in rats is associated with enhanced neurogenesis in thermoregulatory centers of the hypothalamus. To elucidate the mechanisms for heat acclimation, we investigated the effects of direct mild heat exposure on the proliferation and differentiation of neural stem/progenitor cells (NSCs/NPCs). The NSCs/NPCs isolated from forebrain cortices of 14.5-day-old rat fetuses were propagated as neurospheres at either 37.0°C (control) or 38.5°C (mild heat exposure) for four days, and the effects on proliferation were investigated by MTS cell viability assay, measurement of neurosphere diameter, and counting the total number of cells. The mRNA expressions of heat shock proteins (HSPs) and brain-derived neurotrophic factor (BDNF), cAMP response element-binding (CREB) protein and Akt phosphorylation levels, and intracellular reactive oxygen species (ROS) levels were analyzed using real time PCR, Western blotting and CM-H2DCFDA assay respectively. Heat exposure under proliferation condition increased NSC/NPC viability, neurosphere diameter, and cell count. BDNF mRNA expression, CREB phosphorylation, and ROS level were also increased by heat exposure. Heat exposure increased HSP27 mRNA expression concomitant with enhanced p-Akt level. Moreover, treatment with LY294002 (a PI3K inhibitor) abolished the effects of heat exposure on NSC/NPC proliferation. Furthermore, heat exposure under differentiation conditions increased the proportion of cells positive for Tuj1 (a neuronal marker). These findings suggest that mild heat exposure increases NSC/NPC proliferation, possibly through activation of the Akt pathway, and also enhances neuronal differentiation. Direct effects of temperature on NSCs/NPCs may be one of the mechanisms involved in hypothalamic neurogenesis in heat-acclimated rats. Such heat-induced neurogenesis could also be an effective therapeutic strategy for neurodegenerative diseases. PMID:29287093

Does the tissue engineering architecture of poly(3-hydroxybutyrate) scaffold affects cell-material interactions?

PubMed

Masaeli, Elahe; Morshed, Mohammad; Rasekhian, Parsa; Karbasi, Saeed; Karbalaie, Khadije; Karamali, Fereshte; Abedi, Daryoush; Razavi, Shahnaz; Jafarian-Dehkordi, Abbas; Nasr-Esfahani, Mohammad Hossein; Baharvand, Hossein

2012-07-01

A critical element in tissue engineering involves the fabrication of a three-dimensional scaffold. The scaffold provides a space for new tissue formation, supports cellular ingrowth, and proliferation and mimics many roles of the extracellular matrix. Poly(3-hydroxybutyrate) (PHB) is the most thoroughly investigated member of the polyhydroxyalkanoates (PHAs) family that has various degrees of biocompatibility and biodegradability for tissue engineering applications. In this study, we fabricated PHB scaffolds by utilizing electrospinning and salt-leaching procedures. The behavior of monkey epithelial kidney cells (Vero) and mouse mesenchymal stem cells (mMSCs) on these scaffolds was compared by the MTS assay and scanning electron microscopy. Additionally, this study investigated the mechanical and physical properties of these scaffolds by measuring tensile strength and modulus, dynamic contact angle and porosity. According to our results, the salt-leached scaffolds showed more wettability and permeability, but inferior mechanical properties when compared with nanofibrous scaffolds. In terms of cell response, salt-leached scaffolds showed enhanced Vero cell proliferation, whereas both scaffolds responded similarly in the case of mMSCs proliferation. In brief, nanofibrous scaffolds can be a better substrate for cell attachment and morphology. Copyright © 2012 Wiley Periodicals, Inc.

Characterization of mTOR-Responsive Truncated mRNAs in Cell Proliferation

DTIC Science & Technology

2017-07-01

AWARD NUMBER: W81XWH-16-1-0135 TITLE: Characterization of mTOR-Responsive Truncated mRNAs in Cell Proliferation PRINCIPAL INVESTIGATOR...TITLE AND SUBTITLE 5a. CONTRACT NUMBER Characterization of mTOR-Responsive Truncated mRNAs in Cell Proliferation 5b. GRANT NUMBER 8W1XWH-16-1...Sclerosis Complex (TSC) 1 or 2 gene leads to deregulated mTOR activation and consequent cell proliferation/growth. Thus, studying the mTOR pathway

Androgen responsiveness of the new human endometrial cancer cell line MFE-296.

PubMed

Hackenberg, R; Beck, S; Filmer, A; Hushmand Nia, A; Kunzmann, R; Koch, M; Slater, E P; Schulz, K D

1994-04-01

MFE-296 endometrial cancer cells express androgen receptors in vitro. These cells, which are tumorigenic in nude mice, are derived from a moderately differentiated human endometrial adenocarcinoma. They express vimentin and the cytokeratins 7, 8, 18, and 19. Karyotyping revealed near-tetraploidy for most of the cells. No marker chromosomes were observed. DNA analyses confirmed the genetic identity of the cell line and the patient from whom the cell line was derived. Proliferation of MFE-296 cells was inhibited by the progestin R5020 and the androgen dihydrotestosterone (DHT). The inhibition of proliferation by DHT was antagonized by the antiandrogen Casodex, demonstrating the involvement of the androgen receptor. Androgen binding was determined at 22,000 binding sites per cell using a whole-cell assay (KD = 0.05 nM) and 30 fmol/mg protein with the dextran charcoal method; 7 fmol/mg protein of progesterone receptors were found, whereas estrogen receptors were below 5 fmol/mg protein. The androgen receptor was functionally intact, as demonstrated by transfection experiments with a reporter-gene construct, containing an androgen-responsive element. In MFE-296 cells the content of the androgen receptor was up-regulated by its own ligand.

Transcriptional Profiling Identifies Functional Interactions of TGFβ and PPARβ/δ Signaling

PubMed Central

Kaddatz, Kerstin; Adhikary, Till; Finkernagel, Florian; Meissner, Wolfgang; Müller-Brüsselbach, Sabine; Müller, Rolf

2010-01-01

Peroxisome proliferator-activated receptors (PPARs) not only play a key role in regulating metabolic pathways but also modulate inflammatory processes, pointing to a functional interaction between PPAR and cytokine signaling pathways. In this study, we show by genome-wide transcriptional profiling that PPARβ/δ and transforming growth factor-β (TGFβ) pathways functionally interact in human myofibroblasts and that a subset of these genes is cooperatively activated by TGFβ and PPARβ/δ. Using the angiopoietin-like 4 (ANGPTL4) gene as a model, we demonstrate that two enhancer regions cooperate to mediate the observed synergistic response. A TGFβ-responsive enhancer located ∼8 kb upstream of the transcriptional start site is regulated by a mechanism involving SMAD3, ETS1, RUNX, and AP-1 transcription factors that interact with multiple contiguous binding sites. A second enhancer (PPAR-E) consisting of three juxtaposed PPAR response elements is located in the third intron ∼3.5 kb downstream of the transcriptional start site. The PPAR-E is strongly activated by all three PPAR subtypes, with a novel type of PPAR response element motif playing a central role. Although the PPAR-E is not regulated by TGFβ, it interacts with SMAD3, ETS1, RUNX2, and AP-1 in vivo, providing a possible mechanistic explanation for the observed synergism. PMID:20595396

Effects of FSH and 17beta-estradiol on the transactivation of estrogen-regulated promoters and cell proliferation in L cells.

PubMed

Pasapera, Ana María; Jiménez-Aguilera, María del Pilar; Chauchereau, Anne; Milgrom, Edwin; Olivares, Aleida; Uribe, Aída; Gutiérrez-Sagal, Rubén; Ulloa-Aguirre, Alfredo

2005-03-01

In the present study, we analyzed human follicle-stimulating hormone (FSH)-induced cell proliferation and transactivation of estrogen-sensitive reporter genes-in L cells stably expressing the human FSH receptor [L-(hFSHR(+)) cells]. In order to dissect the signaling pathways involved in this process, L-(hFSHR(+)) cells were transiently transfected with either the 3X-ERE-TAT-Luc or the ERE-VitA2-TK-CAT reporter genes and treated with FSH or PKA activators (cholera toxin, forskolin and 8-Br-cAMP) in the presence or absence of various kinase inhibitors. We found that FSH and all PKA activators, specifically induced transactivation of both reporter genes. Transactivation of estrogen-sensitive genes by FSH or PKA activators were blocked (approximately 90%) by H89 (PKA inhibitor) and LY294002 but not by Wortmannin (PI3-K inhibitors), 4-OH-tamoxifen, ICI182,780 or SB203580 (p38 MAPK inhibitor); PD98059 (ERK1/2 inhibitor) partially (approximately 30%) blocked the FSH-mediated effect. The combination of FSH and estradiol resulted in a synergistic effect on transactivation as well as on cell proliferation, and this enhancement was attenuated by antiestrogens. We additionally analyzed the participation of the coactivators SRC-1 and cAMP response element binding protein (CREB)-binding protein (CBP) in FSH-evoked estrogen receptor (ER)-dependent transactivation; we found that CBP but not SRC-1 potentiated FSH-induced transcriptional activation of both ER-sensitive reporters, being this effect stronger on the ERE-VitA2-TK-CAT than on the 3X-ERE-TAT-Luc reporter. Thus, in L-(hFSHR(+)) cells FSH induces transcriptional activation of estrogen-sensitive genes through an A-kinase-triggered signaling pathway, using also to a lesser extent the ERK1/2 and p38 pathways. PI3-K is not apparently involved in this FSH-mediated process since LY294002, but not Wortmannin, specifically binds ERs and completely blocks estrogen action. Presumably, CBP cooperates with the ER on genes that contain estrogen responsive elements through mechanisms involving the participation of other proteins and/or basal transcription factors (e.g. CREB), which in turn mediate the transcriptional response of estrogen-sensitive reporter genes to FSH stimulation.

SERPINE1: A Molecular Switch in the Proliferation-Migration Dichotomy in Wound-“Activated” Keratinocytes

PubMed Central

Simone, Tessa M.; Higgins, Craig E.; Czekay, Ralf-Peter; Law, Brian K.; Higgins, Stephen P.; Archambeault, Jaclyn; Kutz, Stacie M.; Higgins, Paul J.

2014-01-01

Significance: A highly interactive serine protease/plasmin/matrix metalloproteinase axis regulates stromal remodeling in the wound microenvironment. Current findings highlight the importance of stringent controls on protease expression and their topographic activities in cell proliferation, migration, and tissue homeostasis. Targeting elements in this cascading network may lead to novel therapeutic approaches for fibrotic diseases and chronic wounds. Recent Advances: Matrix-active proteases and their inhibitors orchestrate wound site tissue remodeling, cell migration, and proliferation. Indeed, the serine proteases urokinase plasminogen activator and tissue-type plasminogen activator (uPA/tPA) and their major phsyiological inhibitor, plasminogen activator inhibitor-1 (PAI-1; serine protease inhibitor clade E member 1 [SERPINE1]), are upregulated in several cell types during injury repair. Coordinate expression of proteolytic enzymes and their inhibitors in the wound bed provides a mechanism for fine control of focal proteolysis to facilitate matrix restructuring and cell motility in complex environments. Critical Issues: Cosmetic and tissue functional consequences of wound repair anomalies affect the quality of life of millions of patients in the United States alone. The development of novel therapeutics to manage individuals most affected by healing anomalies will likely derive from the identification of critical, translationally accessible, control elements in the wound site microenvironment. Future Directions: Activation of the PAI-1 gene early after wounding, its prominence in the repair transcriptome and varied functions suggest a key role in the global cutaneous injury response program. Targeting PAI-1 gene expression and/or PAI-1 function with molecular genetic constructs, neutralizing antibodies or small molecule inhibitors may provide a novel, therapeutically relevant approach, to manage the pathophysiology of wound healing disorders associated with deficient or excessive PAI-1 levels. PMID:24669362

Assessment of the potential activity of major dietary compounds as selective estrogen receptor modulators in two distinct cell models for proliferation and differentiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lecomte, Sylvain; Lelong, Marie; Bourgine, Gaëlle

Estrogen receptors (ERs) α and β are distributed in most tissues of women and men. ERs are bound by estradiol (E2), a natural hormone, and mediate the pleiotropic and tissue-specific effects of E2, such as proliferation of breast epithelial cells or protection and differentiation of neuronal cells. Numerous environmental molecules, called endocrine disrupting compounds, also interact with ERs. Phytoestrogens belong to this large family and are considered potent therapeutic molecules that act through their selective estrogen receptor modulator (SERM) activity. Using breast cancer cell lines as a model of estrogen-dependent proliferation and a stably ER-expressing PC12 cell line as amore » model of neuronal differentiating cells, we studied the SERM activity of major dietary compounds, such as apigenin, liquiritigenin, daidzein, genistein, coumestrol, resveratrol and zearalenone. The ability of these compounds to induce ER-transactivation and breast cancer cell proliferation and enhance Nerve Growth Factor (NGF) -induced neuritogenesis was assessed. Surprisingly, although all compounds were able to activate the ER through an estrogen responsive element reporter gene, they showed differential activity toward proliferation or differentiation. Apigenin and resveratrol showed a partial or no proliferative effect on breast cancer cells but fully contributed to the neuritogenesis effect of NGF. However, daidzein and zearalenone showed full effects on cellular proliferation but did not induce cellular differentiation. In summary, our results suggest that the therapeutic potential of phytoestrogens can diverge depending on the molecule and the phenotype considered. Hence, apigenin and resveratrol might be used in the development of therapeutics for breast cancer and brain diseases. - Highlights: • SERM activity of dietary compounds on proliferation and differentiation is studied. • All the dietary compounds tested transactivate estrogen receptors. • Apigenin and resveratrol could be good candidates for future therapeutics. • Daidzein and zearalenone are to be avoided to maintain human health.« less

MicroRNA-146a governs fibroblast activation and joint pathology in arthritis.

PubMed

Saferding, Victoria; Puchner, Antonia; Goncalves-Alves, Eliana; Hofmann, Melanie; Bonelli, Michael; Brunner, Julia S; Sahin, Emine; Niederreiter, Birgit; Hayer, Silvia; Kiener, Hans P; Einwallner, Elisa; Nehmar, Ramzi; Carapito, Raphael; Georgel, Philippe; Koenders, Marije I; Boldin, Mark; Schabbauer, Gernot; Kurowska-Stolarska, Mariola; Steiner, Günter; Smolen, Josef S; Redlich, Kurt; Blüml, Stephan

2017-08-01

Synovial fibroblasts are key cells orchestrating the inflammatory response in arthritis. Here we demonstrate that loss of miR-146a, a key epigenetic regulator of the innate immune response, leads to increased joint destruction in a TNF-driven model of arthritis by specifically regulating the behavior of synovial fibroblasts. Absence of miR-146a in synovial fibroblasts display a highly deregulated gene expression pattern and enhanced proliferation in vitro and in vivo. Deficiency of miR-146a induces deregulation of tumor necrosis factor (TNF) receptor associated factor 6 (TRAF6) in synovial fibroblasts, leading to increased proliferation. In addition, loss of miR-146a shifts the metabolic state of fibroblasts towards glycolysis and augments the ability of synovial fibroblasts to support the generation of osteoclasts by controlling the balance of osteoclastogenic regulatory factors receptor activator of NF-κB ligand (RANKL) and osteoprotegerin (OPG). Bone marrow transplantation experiments confirmed the importance of miR-146a in the radioresistant mesenchymal compartment for the control of arthritis severity, in particular for inflammatory joint destruction. This study therefore identifies microRNA-146a as an important local epigenetic regulator of the inflammatory response in arthritis. It is a central element of an anti-inflammatory feedback loop in resident synovial fibroblasts, who are orchestrating the inflammatory response in chronic arthritis. MiR-146a restricts their activation, thereby preventing excessive tissue damage during arthritis. Copyright © 2017 Elsevier Ltd. All rights reserved.

The effect of redox-related species of nitrogen monoxide on transferrin and iron uptake and cellular proliferation of erythroleukemia (K562) cells.

PubMed

Richardson, D R; Neumannova, V; Nagy, E; Ponka, P

1995-10-15

The iron-responsive element-binding protein (IRE-BP) modulates both ferritin mRNA translation and transferrin receptor (TfR) mRNA stability by binding to specific mRNA sequences called iron-responsive elements (IREs). The regulation of IRE-BP in situ could possibly occur either through its Fe-S cluster and/or via free cysteine sulphydryl groups such as cysteine 437 (Philpott et al, J Biol Chem 268:17655, 1993; and Hirling et al, EMBO J 13:453, 1994). Recently, nitrogen monoxide (NO) has been shown to have markedly different biologic effects depending on its redox state (Lipton et al, Nature 364:626, 1993). Considering this fact, it is conceivable that the NO group, as either the nitrosonium ion (NO+) or nitric oxide (NO+), may regulate IRE-BP activity by S-nitrosylation of key sulphydryl groups or via ligation of NO. to the Fe-S cluster, respectively. This hypothesis has been examined using the NO+ generator, sodium nitroprusside (SNP); the NO. generator, S-nitroso-N-acetylpenicillamine (SNAP); and the NO./peroxynitrite (ONOO-) generator, 3-morpholinosydnonimine hydrochloride (SIN-1). Treatment of K562 cells for 18 hours with SNP (1 mmol/L) resulted in a pronounced decrease in both the RNA-binding activity of IRE-BP and the level of TfR mRNA. In addition, Scatchard analysis showed a marked decrease in the number of specific Tf-binding sites, from 590,000/cell (control) to 170,000/cell (test), and there was also a distinct decrease in Fe uptake. Furthermore, SNP did not decrease cellular viability or proliferation. In contrast, the NO. generator, SNAP (1 mmol/L), increased RNA-binding activity of IRE-BP, the level of TfR mRNA, and the number of TfRs in K562 cells. Moreover, both SNAP (1 mmol/L) and SIN-1 (0.5 mmol/L) reduced cellular proliferation. The results are discussed in context of the possible physiologic role of redox-related species of NO in regulating iron metabolism.

Aquaporin 5 Plays a Role in Estrogen-Induced Ectopic Implantation of Endometrial Stromal Cells in Endometriosis

PubMed Central

Jiang, Xiu Xiu; Fei, Xiang Wei; Zhao, Li; Ye, Xiao Lei; Xin, Liao Bin; Qu, Yang; Xu, Kai Hong; Wu, Rui Jin; Lin, Jun

2015-01-01

Aquaporin 5 (AQP5) participates in the migration of endometrial cells. Elucidation of the molecular mechanisms associated with AQP5-mediated, migration of endometrial cells may contribute to a better understanding of endometriosis. Our objectives included identifying the estrogen-response element (ERE) in the promoter region of the AQP5 gene, and, investigating the effects of AQP5 on ectopic implantation of endometrial cells. Luciferase reporter assays and electrophoretic mobility shift assay (EMSA) identified the ERE-like motif in the promoter region of the AQP5 gene. After blocking and up-regulating estradiol (E2) levels, we analysed the expression of AQP5 in endometrial stromal (ES) cells. After blocking E2 /or phosphatidylinositol 3 kinase(PI3K), we analysed the role of AQP5 in signaling pathways. We constructed an AQP5, shRNA, lentiviral vector to knock out the AQP5 gene in ES cells. After knock-out of the AQP5 gene, we studied the role of AQP5 in cell invasion, proliferation, and the formation of ectopic endometrial implants in female mice. We identified an estrogen-response element in the promoter region of the AQP5 gene. Estradiol (E2) increased AQP5 expression in a dose-dependent fashion, that was blocked by ICI182,780(an estrogen receptor inhibitor). E2 activated PI3K /protein kinase B(AKT) pathway (PI3K/AKT), that, in turn, increased AQP5 expression. LY294002(PI3K inhibitor) attenuated estrogen-enhanced, AQP5 expression. Knock-out of the AQP5 gene with AQP5 shRNA lentiviral vector significantly inhibited E2-enhanced invasion, proliferation of ES cells and formation of ectopic implants. Estrogen induces AQP5 expression by activating ERE in the promoter region of the AQP5gene, activates the PI3K/AKT pathway, and, promotes endometrial cell invasion and proliferation. These results provide new insights into some of the mechanisms that may underpin the development of deposits of ectopic endometrium. PMID:26679484

Dynamics and Differential Proliferation of Transposable Elements During the Evolution of the B and A Genomes of Wheat

PubMed Central

Charles, Mathieu; Belcram, Harry; Just, Jérémy; Huneau, Cécile; Viollet, Agnès; Couloux, Arnaud; Segurens, Béatrice; Carter, Meredith; Huteau, Virginie; Coriton, Olivier; Appels, Rudi; Samain, Sylvie; Chalhoub, Boulos

2008-01-01

Transposable elements (TEs) constitute >80% of the wheat genome but their dynamics and contribution to size variation and evolution of wheat genomes (Triticum and Aegilops species) remain unexplored. In this study, 10 genomic regions have been sequenced from wheat chromosome 3B and used to constitute, along with all publicly available genomic sequences of wheat, 1.98 Mb of sequence (from 13 BAC clones) of the wheat B genome and 3.63 Mb of sequence (from 19 BAC clones) of the wheat A genome. Analysis of TE sequence proportions (as percentages), ratios of complete to truncated copies, and estimation of insertion dates of class I retrotransposons showed that specific types of TEs have undergone waves of differential proliferation in the B and A genomes of wheat. While both genomes show similar rates and relatively ancient proliferation periods for the Athila retrotransposons, the Copia retrotransposons proliferated more recently in the A genome whereas Gypsy retrotransposon proliferation is more recent in the B genome. It was possible to estimate for the first time the proliferation periods of the abundant CACTA class II DNA transposons, relative to that of the three main retrotransposon superfamilies. Proliferation of these TEs started prior to and overlapped with that of the Athila retrotransposons in both genomes. However, they also proliferated during the same periods as Gypsy and Copia retrotransposons in the A genome, but not in the B genome. As estimated from their insertion dates and confirmed by PCR-based tracing analysis, the majority of differential proliferation of TEs in B and A genomes of wheat (87 and 83%, respectively), leading to rapid sequence divergence, occurred prior to the allotetraploidization event that brought them together in Triticum turgidum and Triticum aestivum, <0.5 million years ago. More importantly, the allotetraploidization event appears to have neither enhanced nor repressed retrotranspositions. We discuss the apparent proliferation of TEs as resulting from their insertion, removal, and/or combinations of both evolutionary forces. PMID:18780739

Hypoxia-inducible miR-152 suppresses the expression of WNT1 and ERBB3, and inhibits the proliferation of cervical cancer cells.

PubMed

Tang, Xue-Lei; Lin, Li; Song, Li-Na; Tang, Xue-Hong

2016-07-01

Hypoxia has been a research focus in cancer because of its important role in maintaining tumor microenvironments. Previous studies have demonstrated that the expression of several miRNAs was altered under hypoxic conditions, suggesting their crucial roles in the development of cancer. In the present study, the expression of 22 miRNAs reported to be significantly upregulated in cervical cancer tissues was examined. We found that four of these miRNAs were upregulated in response to hypoxia in HeLa cervical cancer cells. MiR-152 was upregulated to the greatest extent and was also found to be upregulated by hypoxia in C33A cells and tumor, but not in non-tumor cervical tissues. Moreover, we found that hypoxia-inducible factor-1α regulated the expression of miR-152 in HeLa cells through a hypoxia-responsive element. A bioinformatic tool predicted that WNT1 and ERBB3 were target genes of miR-152. This was confirmed by dual luciferase assays and Western blots. Overexpression of miR-152 repressed WNT1 and ERBB3 expression and decreased proliferation of HeLa cells. Collectively, these data indicate an important role for miR-152 in regulating the hypoxic response of tumor cells. © 2015 by the Society for Experimental Biology and Medicine.

Restoration of the anti-proliferative and anti-migratory effects of 1,25-dihydroxyvitamin D by silibinin in vitamin D-resistant colon cancer cells.

PubMed

Bhatia, Vandanajay; Falzon, Miriam

2015-07-01

Colorectal carcinoma (CRC) is the third most common cancer in developed countries. A large fraction of cases are linked to chronic intestinal inflammation, with concomitant increased TNF-α release and elevated Snail1/Snail2 levels. These transcription factors in turn suppress vitamin D receptor (VDR) expression, resulting in loss of responsiveness to the protective anti-proliferative and anti-migratory effects of 1,25-dihydroxyvitamin D (1,25D). Experimental and epidemiologic evidence support the use of natural products to target CRC. Here we show that the flavonolignan silibinin reverses the TNF-α-induced upregulation of Snail1 and Snail2 in the 1,25D-resistant human colon carcinoma cells HT-29. These silibinin effects are accompanied by an increase in VDR levels; Snail1 overexpression reverses these silibinin effects. Silibinin also restores promoter activity from a vitamin D-response element (VDRE) reporter construct. While 1,25D had no significant effect on HT-29 and SW480-R cell proliferation and migration, co-treatment with silibinin restored 1,25D responsiveness. In addition, co-treatment with silibinin plus 1,25D decreased proliferation and migration at doses where silibinin alone had no effect. These findings demonstrate that this combination may present a novel approach to target CRC in conditions of chronic colonic inflammation. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Restoration of the anti-proliferative and anti-migratory effects of 1,25-dihydroxyvitamin D by silibinin in vitamin D-resistant colon cancer cells

PubMed Central

Bhatia, Vandanajay; Falzon, Miriam

2015-01-01

Colorectal carcinoma (CRC) is the third most common cancer in developed countries. A large fraction of cases are linked to chronic intestinal inflammation, with concomitant increased TNF-α release and elevated Snail1/Snail2 levels. These transcription factors in turn suppress vitamin D receptor (VDR) expression, resulting in loss of responsiveness to the protective anti-proliferative and anti-migratory effects of 1,25-dihydroxyvitamin D (1,25D). Experimental and epidemiologic evidence support the use of natural products to target CRC. Here we show that the flavonolignan silibinin reverses the TNF-α-induced upregulation of Snail1 and Snail2 in the 1,25D-resistant human colon carcinoma cells HT-29. These silibinin effects are accompanied by an increase in VDR levels; Snail1 overexpression reverses these silibinin effects. Silibinin also restores promoter activity from a vitamin D-response element (VDRE) reporter construct. While 1,25D had no significant effect on HT-29 and SW480-R cell proliferation and migration, co-treatment with silibinin restored 1,25D responsiveness. In addition, co-treatment with silibinin plus 1,25D decreased proliferation and migration at doses where silibinin alone had no effect. These findings demonstrate that this combination may present a novel approach to target CRC in conditions of chronic colonic inflammation. PMID:25846868

Clenbuterol Induces Cell Cycle Arrest in C2C12 Myoblasts by Delaying p27 Degradation through β-arrestin 2 Signaling

PubMed Central

Chen, Min; Liu, Chuncheng; Wang, Meng; Wang, Hong; Zhang, Kuo; Zheng, Yu; Yu, Zhengquan; Li, Xiangdong; Guo, Wei; Li, Ning; Meng, Qingyong

2017-01-01

β2-Adrenoceptor (β2-AR) agonists promote muscle growth. The aim of this study was to elucidate some effects of the selective β2-adrenoceptor agonist clenbuterol (CLB) on myoblast proliferation. We found that CLB induces cell cycle arrest in C2C12 myoblasts. This effect is partly due to the enhanced stability of p27, rather than the increased gene transcription via cAMP response element-binding protein (CREB). Specifically, CLB treatment enhanced the accumulation of p27 in the nucleus while depleting it from the cytosol via a mechanism that requires β2-AR. Surprisingly, p27 accumulation was not reversed by the protein kinase A (PKA) inhibitor H-89, but interestingly, was alleviated by the knockdown of β-arrestin 2. Thus, our work provides a basis for β2-AR agonists inhibit myoblasts proliferation through signaling via β2-AR, β-arrestin 2, and p27. PMID:29104500

Voltage-Gated K+ Channel, Kv3.3 Is Involved in Hemin-Induced K562 Differentiation

PubMed Central

Song, Min Seok; Choi, Seon Young; Ryu, Pan Dong; Lee, So Yeong

2016-01-01

Voltage-gated K+ (Kv) channels are well known to be involved in cell proliferation. However, even though cell proliferation is closely related to cell differentiation, the relationship between Kv channels and cell differentiation remains poorly investigated. This study demonstrates that Kv3.3 is involved in K562 cell erythroid differentiation. Down-regulation of Kv3.3 using siRNA-Kv3.3 increased hemin-induced K562 erythroid differentiation through decreased activation of signal molecules such as p38, cAMP response element-binding protein, and c-fos. Down-regulation of Kv3.3 also enhanced cell adhesion by increasing integrin β3 and this effect was amplified when the cells were cultured with fibronectin. The Kv channels, or at least Kv3.3, appear to be associated with cell differentiation; therefore, understanding the mechanisms of Kv channel regulation of cell differentiation would provide important information regarding vital cellular processes. PMID:26849432

Proto-oncogene FBI-1 (Pokemon) and SREBP-1 Synergistically Activate Transcription of Fatty-acid Synthase Gene (FASN)*S⃞

PubMed Central

Choi, Won-Il; Jeon, Bu-Nam; Park, Hyejin; Yoo, Jung-Yoon; Kim, Yeon-Sook; Koh, Dong-In; Kim, Myung-Hwa; Kim, Yu-Ri; Lee, Choong-Eun; Kim, Kyung-Sup; Osborne, Timothy F.; Hur, Man-Wook

2008-01-01

FBI-1 (Pokemon/ZBTB7A) is a proto-oncogenic transcription factor of the BTB/POZ (bric-à-brac, tramtrack, and broad complex and pox virus zinc finger) domain family. Recent evidence suggested that FBI-1 might be involved in adipogenic gene expression. Coincidentally, expression of FBI-1 and fatty-acid synthase (FASN) genes are often increased in cancer and immortalized cells. Both FBI-1 and FASN are important in cancer cell proliferation. SREBP-1 is a major regulator of many adipogenic genes, and FBI-1 and SREBP-1 (sterol-responsive element (SRE)-binding protein 1) interact with each other directly via their DNA binding domains. FBI-1 enhanced the transcriptional activation of SREBP-1 on responsive promoters, pGL2-6x(SRE)-Luc and FASN gene. FBI-1 and SREBP-1 synergistically activate transcription of the FASN gene by acting on the proximal GC-box and SRE/E-box. FBI-1, Sp1, and SREBP-1 can bind to all three SRE, GC-box, and SRE/E-box. Binding competition among the three transcription factors on the GC-box and SRE/E-box appears important in the transcription regulation. FBI-1 is apparently changing the binding pattern of Sp1 and SREBP-1 on the two elements in the presence of induced SREBP-1 and drives more Sp1 binding to the proximal promoter with less of an effect on SREBP-1 binding. The changes induced by FBI-1 appear critical in the synergistic transcription activation. The molecular mechanism revealed provides insight into how proto-oncogene FBI-1 may attack the cellular regulatory mechanism of FASN gene expression to provide more phospholipid membrane components needed for rapid cancer cell proliferation. PMID:18682402

PPARγ and NF-κB regulate the gene promoter activity of their shared repressor, TNIP1

PubMed Central

Gurevich, Igor; Zhang, Carmen; Encarnacao, Priscilla C.; Struzynski, Charles P.; Livings, Sarah E.; Aneskievich, Brian J.

2011-01-01

Human TNFAIP3 interacting protein 1 (TNIP1) has diverse functions including support of HIV replication through its interaction with viral Nef and matrix proteins, reduction of TNFα-induced signaling through its interaction with NF-κB pathway proteins, and corepression of agonist-bound retinoic acid receptors and peroxisome proliferator-activated receptors (PPAR). The wide tissue distribution of TNIP1 provides the opportunity to influence numerous cellular responses in these roles and defining control of TNIP1 expression would be central to improved understanding of its impact on cell function. We cloned 6kb of the human TNIP1 promoter and performed predictive and functional analyses to identify regulatory elements. The promoter region proximal to the transcription start site is GC-rich without a recognizable TATA box. In contrast to this proximal ~500bp region, 6kb of the promoter increased reporter construct constitutive activity over five-fold. Throughout the 6kb length, in silico analysis identified several potential binding sites for both constitutive and inducible transcription factors; among the latter were candidate NF-κB binding sequences and peroxisome proliferator response elements (PPREs). We tested NF-κB and PPAR regulation of the endogenous TNIP1 gene and cloned promoter by expression studies, electrophoretic mobility shift assays, and chromatin immunoprecipitations. We validated NF-κB sites in the TNIP1 promoter proximal and distal regions as well as one PPRE in the distal region. The ultimate control of the TNIP1 promoter is likely to be a combination of constitutive transcription factors and those subject to activation such as NF-κB and PPAR. PMID:22001530

Proto-oncogene FBI-1 (Pokemon) and SREBP-1 synergistically activate transcription of fatty-acid synthase gene (FASN).

PubMed

Choi, Won-Il; Jeon, Bu-Nam; Park, Hyejin; Yoo, Jung-Yoon; Kim, Yeon-Sook; Koh, Dong-In; Kim, Myung-Hwa; Kim, Yu-Ri; Lee, Choong-Eun; Kim, Kyung-Sup; Osborne, Timothy F; Hur, Man-Wook

2008-10-24

FBI-1 (Pokemon/ZBTB7A) is a proto-oncogenic transcription factor of the BTB/POZ (bric-à-brac, tramtrack, and broad complex and pox virus zinc finger) domain family. Recent evidence suggested that FBI-1 might be involved in adipogenic gene expression. Coincidentally, expression of FBI-1 and fatty-acid synthase (FASN) genes are often increased in cancer and immortalized cells. Both FBI-1 and FASN are important in cancer cell proliferation. SREBP-1 is a major regulator of many adipogenic genes, and FBI-1 and SREBP-1 (sterol-responsive element (SRE)-binding protein 1) interact with each other directly via their DNA binding domains. FBI-1 enhanced the transcriptional activation of SREBP-1 on responsive promoters, pGL2-6x(SRE)-Luc and FASN gene. FBI-1 and SREBP-1 synergistically activate transcription of the FASN gene by acting on the proximal GC-box and SRE/E-box. FBI-1, Sp1, and SREBP-1 can bind to all three SRE, GC-box, and SRE/E-box. Binding competition among the three transcription factors on the GC-box and SRE/E-box appears important in the transcription regulation. FBI-1 is apparently changing the binding pattern of Sp1 and SREBP-1 on the two elements in the presence of induced SREBP-1 and drives more Sp1 binding to the proximal promoter with less of an effect on SREBP-1 binding. The changes induced by FBI-1 appear critical in the synergistic transcription activation. The molecular mechanism revealed provides insight into how proto-oncogene FBI-1 may attack the cellular regulatory mechanism of FASN gene expression to provide more phospholipid membrane components needed for rapid cancer cell proliferation.

Mangiferin activates Nrf2-antioxidant response element signaling without reducing the sensitivity to etoposide of human myeloid leukemia cells in vitro

PubMed Central

Zhang, Ben-ping; Zhao, Jie; Li, Shan-shan; Yang, Li-jing; Zeng, Ling-lan; Chen, Yan; Fang, Jun

2014-01-01

Aim: Mangiferin is glucosylxanthone extracted from plants of the Anacardiaceae and Gentianaceae families. The aim of this study was to investigate the effects of mangiferin on Nrf2-antioxidant response element (ARE) signaling and the sensitivity to etoposide of human myeloid leukemia cells in vitro. Methods: Human HL-60 myeloid leukemia cells and mononuclear human umbilical cord blood cells (MNCs) were examined. Nrf2 protein was detected using immunofluorescence staining and Western blotting. Binding of Nrf2 to ARE was examined with electrophoretic mobility shift assay. The level of NQO1 was assessed with real-time RT-PCR and Western blotting. DCFH-DA was used to evaluate intracellular ROS level. Cell proliferation and apoptosis were analyzed using MTT and flow cytometry, respectively. Results: Mangiferin (50 μmol/L) significantly increased Nrf2 protein accumulation in HL-60 cells, particularly in the nucleus. Mangiferin also enhanced the binding of Nrf2 to an ARE, significantly up-regulated NQO1 expression and reduced intracellular ROS in HL60 cells. Mangiferin alone dose-dependently inhibited the proliferation of HL-60 cells. Mangiferin (50 mol/L) did not attenuate etoposide-induced cytotoxicity in HL-60 cells, and combined treatment of mangiferin with low concentration of etoposide (0.8 μg/mL) even increased the cell inhibition rate. Nor did mangiferin change the rate of etoposide-induced apoptosis in HL-60 cells. In MNCs, mangiferin significantly relieved oxidative stress, but attenuated etoposide-induced cytotoxicity. Conclusion: Mangiferin is a novel Nrf2 activator that reduces oxidative stress and protects normal cells without reducing the sensitivity to etoposide of HL-60 leukemia cells in vitro. Mangiferin may be a potential chemotherapy adjuvant. PMID:24374812

Mangiferin activates Nrf2-antioxidant response element signaling without reducing the sensitivity to etoposide of human myeloid leukemia cells in vitro.

PubMed

Zhang, Ben-ping; Zhao, Jie; Li, Shan-shan; Yang, Li-jing; Zeng, Ling-lan; Chen, Yan; Fang, Jun

2014-02-01

Mangiferin is glucosylxanthone extracted from plants of the Anacardiaceae and Gentianaceae families. The aim of this study was to investigate the effects of mangiferin on Nrf2-antioxidant response element (ARE) signaling and the sensitivity to etoposide of human myeloid leukemia cells in vitro. Human HL-60 myeloid leukemia cells and mononuclear human umbilical cord blood cells (MNCs) were examined. Nrf2 protein was detected using immunofluorescence staining and Western blotting. Binding of Nrf2 to ARE was examined with electrophoretic mobility shift assay. The level of NQO1 was assessed with real-time RT-PCR and Western blotting. DCFH-DA was used to evaluate intracellular ROS level. Cell proliferation and apoptosis were analyzed using MTT and flow cytometry, respectively. Mangiferin (50 μmol/L) significantly increased Nrf2 protein accumulation in HL-60 cells, particularly in the nucleus. Mangiferin also enhanced the binding of Nrf2 to an ARE, significantly up-regulated NQO1 expression and reduced intracellular ROS in HL60 cells. Mangiferin alone dose-dependently inhibited the proliferation of HL-60 cells. Mangiferin (50 mol/L) did not attenuate etoposide-induced cytotoxicity in HL-60 cells, and combined treatment of mangiferin with low concentration of etoposide (0.8 μg/mL) even increased the cell inhibition rate. Nor did mangiferin change the rate of etoposide-induced apoptosis in HL-60 cells. In MNCs, mangiferin significantly relieved oxidative stress, but attenuated etoposide-induced cytotoxicity. Mangiferin is a novel Nrf2 activator that reduces oxidative stress and protects normal cells without reducing the sensitivity to etoposide of HL-60 leukemia cells in vitro. Mangiferin may be a potential chemotherapy adjuvant.

Antiproliferative Activity of Fucan Nanogel

PubMed Central

Dantas-Santos, Nednaldo; Almeida-Lima, Jailma; Vidal, Arthur Anthunes Jacome; Gomes, Dayanne Lopes; Oliveira, Ruth Medeiros; Santos Pedrosa, Silvia; Pereira, Paula; Gama, Francisco Miguel; Oliveira Rocha, Hugo Alexandre

2012-01-01

Sulfated fucans comprise families of polydisperse natural polysaccharides based on sulfated L-fucose. Our aim was to investigate whether fucan nanogel induces cell-specific responses. To that end, a non toxic fucan extracted from Spatoglossum schröederi was chemically modified by grafting hexadecylamine to the polymer hydrophilic backbone. The resulting modified material (SNFuc) formed nanosized particles. The degree of substitution with hydrophobic chains was close to 100%, as estimated by elemental analysis. SNFfuc in aqueous media had a mean diameter of 123 nm and zeta potential of −38.3 ± 0.74 mV, as measured by dynamic light scattering. Nanoparticles conserved their size for up to 70 days. SNFuc cytotoxicity was determined using the MTT assay after culturing different cell lines for 24 h. Tumor-cell (HepG2, 786, H-S5) proliferation was inhibited by 2.0%–43.7% at nanogel concentrations of 0.05–0.5 mg/mL and rabbit aorta endothelial cells (RAEC) non-tumor cell line proliferation displayed inhibition of 8.0%–22.0%. On the other hand, nanogel improved Chinese hamster ovary (CHO) and monocyte macrophage cell (RAW) non-tumor cell line proliferation in the same concentration range. The antiproliferative effect against tumor cells was also confirmed using the BrdU test. Flow cytometric analysis revealed that the fucan nanogel inhibited 786 cell proliferation through caspase and caspase-independent mechanisms. In addition, SNFuc blocks 786 cell passages in the S and G2-M phases of the cell cycle. PMID:23118717

Zirconium Ions Up-Regulate the BMP/SMAD Signaling Pathway and Promote the Proliferation and Differentiation of Human Osteoblasts

PubMed Central

Chen, Yongjuan; Roohani-Esfahani, Seyed-Iman; Lu, ZuFu; Zreiqat, Hala; Dunstan, Colin R.

2015-01-01

Zirconium (Zr) is an element commonly used in dental and orthopedic implants either as zirconia (ZrO2) or in metal alloys. It can also be incorporated into calcium silicate-based ceramics. However, the effects of in vitro culture of human osteoblasts (HOBs) with soluble ionic forms of Zr have not been determined. In this study, primary culture of human osteoblasts was conducted in the presence of medium containing either ZrCl4 or Zirconium (IV) oxynitrate (ZrO(NO3)2) at concentrations of 0, 5, 50 and 500 µM, and osteoblast proliferation, differentiation and calcium deposition were assessed. Incubation of human osteoblast cultures with Zr ions increased the proliferation of human osteoblasts and also gene expression of genetic markers of osteoblast differentiation. In 21 and 28 day cultures, Zr ions at concentrations of 50 and 500 µM increased the deposition of calcium phosphate. In addition, the gene expression of BMP2 and BMP receptors was increased in response to culture with Zr ions and this was associated with increased phosphorylation of SMAD1/5. Moreover, Noggin suppressed osteogenic gene expression in HOBs co-treated with Zr ions. In conclusion, Zr ions appear able to induce both the proliferation and the differentiation of primary human osteoblasts. This is associated with up-regulation of BMP2 expression and activation of BMP signaling suggesting this action is, at least in part, mediated by BMP signaling. PMID:25602473

AMPKα1 controls hepatocyte proliferation independently of energy balance by regulating Cyclin A2 expression.

PubMed

Merlen, Grégory; Gentric, Géraldine; Celton-Morizur, Séverine; Foretz, Marc; Guidotti, Jacques-Emmanuel; Fauveau, Véronique; Leclerc, Jocelyne; Viollet, Benoit; Desdouets, Chantal

2014-01-01

AMP-activated protein kinase (AMPK) is an evolutionarily conserved sensor of cellular energy status that contributes to restoration of energy homeostasis by slowing down ATP-consuming pathways and activating ATP-producing pathways. Unexpectedly, in different systems, AMPK is also required for proper cell division. In the current study, we evaluated the potential effect of the AMPK catalytic subunit, AMPKα1, on hepatocyte proliferation. Hepatocyte proliferation was determined in AMPKα1 knockout and wild-type mice in vivo after two thirds partial hepatectomy, and in vitro in primary hepatocyte cultures. The activities of metabolic and cell cycle-related signaling pathways were measured. After partial hepatectomy, hepatocytes proliferated rapidly, correlating with increased AMPK phosphorylation. Deletion of AMPKα1 delayed liver regeneration by impacting on G1/S transition phase. The proliferative defect of AMPKα1-deficient hepatocytes was cell autonomous, and independent of energy balance. The priming phase, lipid droplet accumulation, protein anabolic responses and growth factor activation after partial hepatectomy occurred normally in the absence of AMPKα1 activity. By contrast, mRNA and protein expression of cyclin A2, a key driver of S phase progression, were compromised in the absence of AMPK activity. Importantly, AMPKα1 controlled cyclin A2 transcription mainly through the ATF/CREB element. Our study highlights a novel role for AMPKα1 as a positive regulator of hepatocyte division occurring independently of energy balance. Copyright © 2013 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cherukuri, Durga Prasad; Chen, Xiao B.O.; Goulet, Anne-Christine

Accumulating evidence indicates that elevated levels of prostaglandin E{sub 2} (PGE{sub 2}) can increase intestinal epithelial cell proliferation, and thus play a role in colorectal tumorigenesis. PGE{sub 2} exerts its effects through four G-protein-coupled PGE receptor (EP) subtypes, named the EP1, EP2, EP3, and EP4. Increased phosphorylation of extracellular regulated kinases (ERK1/2) is required for PGE{sub 2} to stimulate cell proliferation of human colon cancer cells. However, the EP receptor(s) that are involved in this process remain unknown. We provide evidence that L-161,982, a selective EP4 receptor antagonist, completely blocks PGE{sub 2}-induced ERK phosphorylation and cell proliferation of HCA-7 cells.more » In order to identify downstream target genes of ERK1/2 signaling, we found that PGE{sub 2} induces expression of early growth response gene-1 (EGR-1) downstream of ERK1/2 and regulates its expression at the level of transcription. PGE{sub 2} treatment induces phosphorylation of cyclic AMP response element binding protein (CREB) at Ser133 residue and CRE-mediated luciferase activity in HCA-7 cells. Studies with dominant-negative CREB mutant (ACREB) provide clear evidence for the involvement of CREB in PGE{sub 2} driven egr-1 transcription in HCA-7 cells. In conclusion, this study reveals that egr-1 is a target gene of PGE{sub 2} in HCA-7 cells and is regulated via the newly identified EP4/ERK/CREB pathway. Finally our results support the notion that antagonizing EP4 receptors may provide a novel therapeutic approach to the treatment of colon cancer.« less

Zinc enhances the number of regulatory T cells in allergen-stimulated cells from atopic subjects.

PubMed

Rosenkranz, Eva; Hilgers, Ralf-Dieter; Uciechowski, Peter; Petersen, Arnd; Plümäkers, Birgit; Rink, Lothar

2017-03-01

The trace element zinc is essential for immune function and its regulation. Since zinc deficiency and allergic hyperresponsive reactions are often accompanied, the influence of zinc on allergen-induced cell growth, CD4+ regulatory T (Treg) cell numbers and cytokine expression during allergic immune reactions was investigated. Peripheral blood mononuclear cells (PBMCs) from non-atopic and atopic subjects were treated with timothy grass allergen pre-incubated with or without zinc. Proliferation was determined by analyzing the incorporation of 3 H-thymidine. Intracellular zinc and Foxp3 levels and cell surface antigens were measured by FACS, cytokine expression by ELISA and real-time PCR. Incubation with 50 μM zinc sulfate (Zn50) enhances cytosolic zinc concentrations in CD3+ T cells. The data also reveal that the combination of Zn50 plus allergen significantly reduces PBMC proliferation of atopic subjects. Additionally, Zn50 plus allergen enhances Th1 cytokine responses shown by increased interferon (IFN)-γ/interleukin (IL)-10 ratios as well as enhanced tumor necrosis factor-α release. In response to allergen, zinc increases Treg cells and upregulates the mRNA expression of cytotoxic T-lymphocyte antigen-4 in atopic subjects. Interestingly, Zn50 alone leads to an increase of CD4+CD25high(hi)+ cells in atopic and non-atopic subjects. Zinc may regulate unwanted hyperresponsive immune reactions by suppressing proliferation through a significant shift from IL-10 to the Th1 cytokine IFN-γ, and enhanced regulatory T cell numbers. Therefore, zinc supplementation may be a promising tool for the therapy of allergies, without negatively affecting the immune system.

Silibinin inhibits aberrant lipid metabolism, proliferation and emergence of androgen-independence in prostate cancer cells via primarily targeting the sterol response element binding protein 1

PubMed Central

Nambiar, Dhanya K.; Deep, Gagan; Singh, Rana P.; Agarwal, Chapla; Agarwal, Rajesh

2014-01-01

Prostate cancer (PCA) kills thousands of men every year, demanding additional approaches to better understand and target this malignancy. Recently, critical role of aberrant lipogenesis is highlighted in prostate carcinogenesis, offering a unique opportunity to target it to reduce PCA. Here, we evaluated efficacy and associated mechanisms of silibinin in inhibiting lipid metabolism in PCA cells. At physiologically achievable levels in human, silibinin strongly reduced lipid and cholesterol accumulation specifically in human PCA cells but not in non-neoplastic prostate epithelial PWR-1E cells. Silibinin also decreased nuclear protein levels of sterol regulatory element binding protein 1 and 2 (SREBP1/2) and their target genes only in PCA cells. Mechanistically, silibinin activated AMPK, thereby increasing SREBP1 phosphorylation and inhibiting its nuclear translocation; AMPK inhibition reversed silibinin-mediated decrease in nuclear SREBP1 and lipid accumulation. Additionally, specific SREBP inhibitor fatostatin and stable overexpression of SREBP1 further confirmed the central role of SREBP1 in silibinin-mediated inhibition of PCA cell proliferation and lipid accumulation and cell cycle arrest. Importantly, silibinin also inhibited synthetic androgen R1881-induced lipid accumulation and completely abrogated the development of androgen-independent LNCaP cell clones via targeting SREBP1/2. Together, these mechanistic studies suggest that silibinin would be effective against PCA by targeting critical aberrant lipogenesis. PMID:25294820

Silibinin inhibits aberrant lipid metabolism, proliferation and emergence of androgen-independence in prostate cancer cells via primarily targeting the sterol response element binding protein 1.

PubMed

Nambiar, Dhanya K; Deep, Gagan; Singh, Rana P; Agarwal, Chapla; Agarwal, Rajesh

2014-10-30

Prostate cancer (PCA) kills thousands of men every year, demanding additional approaches to better understand and target this malignancy. Recently, critical role of aberrant lipogenesis is highlighted in prostate carcinogenesis, offering a unique opportunity to target it to reduce PCA. Here, we evaluated efficacy and associated mechanisms of silibinin in inhibiting lipid metabolism in PCA cells. At physiologically achievable levels in human, silibinin strongly reduced lipid and cholesterol accumulation specifically in human PCA cells but not in non-neoplastic prostate epithelial PWR-1E cells. Silibinin also decreased nuclear protein levels of sterol regulatory element binding protein 1 and 2 (SREBP1/2) and their target genes only in PCA cells. Mechanistically, silibinin activated AMPK, thereby increasing SREBP1 phosphorylation and inhibiting its nuclear translocation; AMPK inhibition reversed silibinin-mediated decrease in nuclear SREBP1 and lipid accumulation. Additionally, specific SREBP inhibitor fatostatin and stable overexpression of SREBP1 further confirmed the central role of SREBP1 in silibinin-mediated inhibition of PCA cell proliferation and lipid accumulation and cell cycle arrest. Importantly, silibinin also inhibited synthetic androgen R1881-induced lipid accumulation and completely abrogated the development of androgen-independent LNCaP cell clones via targeting SREBP1/2. Together, these mechanistic studies suggest that silibinin would be effective against PCA by targeting critical aberrant lipogenesis.

NMDA receptor mediates proliferation and CREB phosphorylation in postnatal Müller glia-derived retinal progenitors

PubMed Central

Ramírez, Mónica

2009-01-01

Purpose Postnatal retinal Müller glia are considered to be retinal progenitors as they retain the ability to dedifferentiate, proliferate, and differentiate to new retinal glia and neurons after injury. The proliferation and differentiation processes are coordinated by several extrinsic factors and neurotransmitters, including glutamate. Thus, the appropriate numbers and proportions of the different cell types are generated to form a functional retina during development and during injury repair. Here we analyze the changes in the proliferation of postnatal Müller glia-derived progenitors after activation of the N-methyl-D-aspartate (NMDA) glutamate receptors. Methods Müller glia-derived progenitor cell cultures were characterized by immunocytochemistry with antibodies against the NR1 subunit of the NMDA receptor and the progenitor cell marker nestin. The effect of glutamate receptor agonists and antagonists on cell proliferation was analyzed by BrdU incorporation or Ki67 immunostaining, cell counting, and by immunolabeling of phosphorylated cAMP response element binding protein (P-CREB) transcription factor. The effect of NMDA receptor activation was analyzed in vivo by P-CREB immunohistochemistry in retinal sections of Long-Evans NMDA injected rats. Results We show that NMDA receptor activation significantly increases the proliferation rate of Müller-glia derived progenitor cells and that this increase can be blocked by NMDA receptor antagonists. Furthermore, we show that CREB phosphorylation is induced in NMDA-treated Müller-glia derived progenitor cells in culture and that specific pharmacological inhibition of CREB phosphorylation results in a decreased number of proliferating cells. We confirmed the relevance of these observations by the analysis of retinal sections after NMDA injection in vivo where immunoreactivity to phosphorylated CREB is also increased after treatment. Conclusions In the present study we show that NMDA receptor activation induces postnatal Müller glia-derived retinal cell progenitor proliferation and transcription factor CREB phosphorylation both in culture and in vivo. The identification of the molecular determinants of mature retinal progenitors such as transcription factor CREB and NMDA receptor-induced players should facilitate the control of growth and manipulation of progenitor cell cultures and the possible identification of the molecular mechanisms involved in progenitor self-renewal. PMID:19365572

Estrogen induced {beta}-1,4-galactosyltransferase 1 expression regulates proliferation of human breast cancer MCF-7 cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Choi, Hee-Jung; Division of Applied Medicine, School of Korean Medicine, Pusan National University, Yangsan-city, Gyeongsangnam-do; Chung, Tae-Wook

2012-10-05

Highlights: Black-Right-Pointing-Pointer We examined the regulation and biological functions of B4GALT1 expression induced by estrogen. Black-Right-Pointing-Pointer Estrogen-induced B4GALT1 expression through the direct binding of ER-{alpha} to ERE in MCF-7 cells. Black-Right-Pointing-Pointer B4GALT1 expression activates the proliferation of MCF-7 cells via its receptor function. Black-Right-Pointing-Pointer Thus, we suggest B4GALT1 as a molecular target for inhibiting breast cancer proliferation. -- Abstract: Beta 1,4-galactosyltransferase 1 (B4GALT1) synthesizes galactose {beta}-1,4-N-acetylglucosamine (Gal{beta}1-4GlcNAc) groups on N-linked sugar chains of glycoproteins, which play important roles in many biological events, including the proliferation and migration of cancer cells. A previous microarray study reported that this gene is expressedmore » by estrogen treatment in breast cancer. In this study, we examined the regulatory mechanisms and biological functions of estrogen-induced B4GALT1 expression. Our data showed that estrogen-induced expression of B4GALT1 is localized in intracellular compartments and in the plasma membrane. In addition, B4GALT1 has an enzyme activity involved in the production of the Gal{beta}1-4GlcNAc structure. The result from a promoter assay and chromatin immunoprecipitation revealed that 3 different estrogen response elements (EREs) in the B4GALT1 promoter are critical for responsiveness to estrogen. In addition, the estrogen antagonists ICI 182,780 and ER-{alpha}-ERE binding blocker TPBM inhibit the expression of estrogen-induced B4GALT1. However, the inhibition of signal molecules relating to the extra-nuclear pathway, including the G-protein coupled receptors, Ras, and mitogen-activated protein kinases, had no inhibitory effects on B4GALT1 expression. The knock-down of the B4GALT1 gene and the inhibition of membrane B4GALT1 function resulted in the significant inhibition of estrogen-induced proliferation of MCF-7 cells. Considering these results, we propose that estrogen regulates the expression of B4GALT1 through the direct binding of ER-{alpha} to ERE and that the expressed B4GALT1 plays a crucial role in the proliferation of MCF-7 cells through its activity as a membrane receptor.« less

17Beta-estradiol signaling and regulation of proliferation and apoptosis of rat Sertoli cells.

PubMed

Royer, Carine; Lucas, Thaís F G; Lazari, Maria F M; Porto, Catarina S

2012-04-01

The aim of the present study was to investigate the intracellular signaling events downstream of the classical estrogen receptors (ESRs) and G protein-coupled estrogen receptor 1 (GPER) involved in regulation of proliferation and apoptosis of rat Sertoli cells, in which we have previously described ESR1, ESR2, and GPER. ESRs play a role in Sertoli cell proliferation, and GPER, but not ESRs, plays a role modulating gene expression involved with apoptosis. The present study shows that 17beta-estradiol (E2) and the GPER-selective agonist G-1 rapidly activate phosphatidylinositol 3-kinase (PIK3)/serine threonine protein kinase (AKT) and cyclic AMP response element-binding (CREB) phosphorylation. E2 and the ESR1-selective agonist 4,4',4″-(4-propyl-(1H)-pyrazole-1,3,5-triyl)trisphenol (PPT) increase the expression of cyclin D1 (CCND1), whereas the ESR2-selective agonist 2,3-bis(4-hydroxyphenyl)-propionitrile (DPN) and G-1 do not change the expression of this protein, suggesting that ESR1 is the upstream receptor regulating Sertoli cell proliferation. E2- or PPT-ESR1, through activation of epidermal growth factor receptor (EGFR)/mitogen-activated protein kinase 3/1 (MAPK3/1) and PIK3 pathways, induces upregulation of CCND1. KG-501, the compound that disrupts the phospho-CREB/CREB binding protein (CBP) complex, does not change E2- or PPT-ESR1-mediated CCND1 expression, suggesting that phospho-CREB/cyclic AMP response element/CBP is not involved in the expression of this protein. E2- or G-1-GPER, through activation of EGFR/MAPK3/1 and PIK3 pathways, may be involved in the upregulation of antiapoptotic proteins BCL2 and BCL2L2. E2- or G-1-GPER/EGFR/MAPK3/1/phospho-CREB decreases BAX expression. Taken together, these results show a differential effect of E2-GPER on the CREB-mediated transcription of proapoptotic and antiapoptotic genes of the same BCL2 gene family. ESR1 and GPER can mediate the rapid E2 actions in the Sertoli cells, which in turn can modulate nuclear transcriptional events important for Sertoli cell function and maintenance of normal testis development and homeostasis. Our findings are important to clarify the role of estrogen in a critical period of testicular development, and to direct further studies, which may contribute to better understanding of the causes of male infertility.

Protein Kinase Cα Modulates Estrogen-Receptor-Dependent Transcription and Proliferation in Endometrial Cancer Cells

PubMed Central

Thorne, Alicia M.; Jackson, Twila A.; Willis, Van C.; Bradford, Andrew P.

2013-01-01

Endometrial cancer is the most common invasive gynecologic malignancy in developed countries. The most prevalent endometrioid tumors are linked to excessive estrogen exposure and hyperplasia. However, molecular mechanisms and signaling pathways underlying their etiology and pathophysiology remain poorly understood. We have shown that protein kinase Cα (PKCα) is aberrantly expressed in endometrioid tumors and is an important mediator of endometrial cancer cell survival, proliferation, and invasion. In this study, we demonstrate that expression of active, myristoylated PKCα conferred ligand-independent activation of estrogen-receptor- (ER-) dependent promoters and enhanced responses to estrogen. Conversely, knockdown of PKCα reduced ER-dependent gene expression and inhibited estrogen-induced proliferation of endometrial cancer cells. The ability of PKCα to potentiate estrogen activation of ER-dependent transcription was attenuated by inhibitors of phosphoinositide 3-kinase (PI3K) and Akt. Evidence suggests that PKCα and estrogen signal transduction pathways functionally interact, to modulate ER-dependent growth and transcription. Thus, PKCα signaling, via PI3K/Akt, may be a critical element of the hyperestrogenic environment and activation of ER that is thought to underlie the development of estrogen-dependent endometrial hyperplasia and malignancy. PKCα-dependent pathways may provide much needed prognostic markers of aggressive disease and novel therapeutic targets in ER positive tumors. PMID:23843797

Survivin, a target to modulate the radiosensitivity of Ewing's sarcoma.

PubMed

Greve, B; Sheikh-Mounessi, F; Kemper, B; Ernst, I; Götte, M; Eich, H T

2012-11-01

Radiotherapy constitutes an essential element in the multimodal therapy of Ewing's sarcoma. Compared to other sarcomas, Ewing tumors normally show a good response to radiotherapy. However, there are consistently tumors with a radioresistant phenotype, and the underlying mechanisms are not known in detail. Here we investigated the association between survivin protein expression and the radiosensitivity of Ewing's sarcoma in vitro. An siRNA-based knockdown approach was used to investigate the influence of survivin expression on cell proliferation, double-strand break (DSB) induction and repair, apoptosis and colony-forming ability in four Ewing's sarcoma cell lines with and without irradiation. Survivin protein and mRNA were upregulated in all cell lines tested in a dose-dependent manner. As a result of survivin knockdown, STA-ET-1 cells showed reduced cell proliferation, an increased number of radiation-induced DSBs, and reduced repair. Apoptosis was increased by knockdown alone and increased further in combination with irradiation. Colony formation was significantly reduced by survivin knockdown in combination with irradiation. Survivin is a radiation-inducible protein in Ewing's sarcoma and its down-regulation sensitizes cells toward irradiation. Survivin knockdown in combination with radiation inhibits cell proliferation, repair, and colony formation significantly and increases apoptosis more than each single treatment alone. This might open new perspectives in the radiation treatment of Ewing's sarcoma.

The Hippo pathway member Yap plays a key role in influencing fate decisions in muscle satellite cells

PubMed Central

Judson, Robert N.; Tremblay, Annie M.; Knopp, Paul; White, Robert B.; Urcia, Roby; De Bari, Cosimo; Zammit, Peter S.; Camargo, Fernando D.; Wackerhage, Henning

2012-01-01

Summary Satellite cells are the resident stem cells of skeletal muscle. Mitotically quiescent in mature muscle, they can be activated to proliferate and generate myoblasts to supply further myonuclei to hypertrophying or regenerating muscle fibres, or self-renew to maintain the resident stem cell pool. Here, we identify the transcriptional co-factor Yap as a novel regulator of satellite cell fate decisions. Yap expression increases during satellite cell activation and Yap remains highly expressed until after the differentiation versus self-renewal decision is made. Constitutive expression of Yap maintains Pax7+ and MyoD+ satellite cells and satellite cell-derived myoblasts, promotes proliferation but prevents differentiation. In contrast, Yap knockdown reduces the proliferation of satellite cell-derived myoblasts by ≈40%. Consistent with the cellular phenotype, microarrays show that Yap increases expression of genes associated with Yap inhibition, the cell cycle, ribosome biogenesis and that it represses several genes associated with angiotensin signalling. We also identify known regulators of satellite cell function such as BMP4, CD34 and Myf6 (Mrf4) as genes whose expression is dependent on Yap activity. Finally, we confirm in myoblasts that Yap binds to Tead transcription factors and co-activates MCAT elements which are enriched in the proximal promoters of Yap-responsive genes. PMID:23038772

Langerhans’ cell histiocytosis involving posterior elements of the dorsal spine: An unusual cause of extradural spinal mass in an adult

PubMed Central

Tyagi, Devendra K.; Balasubramaniam, Srikant; Savant, Hemant V.

2011-01-01

Langerhans cell histiocytosis (LCH) is a clonal proliferation of Langerhans cells occurring as an isolated lesion or as part of a systemic proliferation. It is commoner in children younger than 10 years of age with sparing of the posterior elements in more than 95% of cases. We describe a case of LCH in an adult female presenting with paraplegia. MRI revealed a well-defined extradural contrast enhancing mass at D2-D4 vertebral level involving the posterior elements of spine. D2-5 laminectomy with excision of lesion was performed which lead to marked improvement of patients neurological status. Histopathology was suggestive of eosinophilic granuloma. We describe the case, discuss its uniqueness and review the literature on this rare tumor presentation. PMID:23125497

Enhanced MC3T3-E1 preosteoblast response and bone formation on the addition of nano-needle and nano-porous features to microtopographical titanium surfaces.

PubMed

Zhuang, X-M; Zhou, B; Ouyang, J-L; Sun, H-P; Wu, Y-L; Liu, Q; Deng, F-L

2014-08-01

Micro/nanotopographical modifications on titanium surfaces constitute a new process to increase osteoblast response to enhance bone formation. In this study, we utilized alkali heat treatment at high (SB-AH1) and low temperatures (SB-AH2) to nano-modify sandblasted titanium with microtopographical surfaces. Then, we evaluated the surface properties, biocompatibility and osteogenic capability of SB-AH1 and SB-AH2 in vitro and in vivo, and compared these with conventional sandblast-acid etching (SLA) and Ti control surfaces. SB-AH1 and SB-AH2 surfaces exhibited micro/nanotopographical modifications of nano-needle structures and nano-porous network layers, respectively, compared with the sole microtopographical surface of macro and micro pits on the SLA surface and the relatively smooth surface on the Ti control. SB-AH1 and SB-AH2 showed different roughness and elemental components, but similar wettability. MC3T3-E1 preosteoblasts anchored closely on the nanostructures of SB-AH1 and SB-AH2 surfaces, and these two surfaces more significantly enhanced cell proliferation and alkaline phosphatase (ALP) activity than others, while the SB-AH2 surface exhibited better cell proliferation and higher ALP activity than SB-AH1. All four groups of titanium domes with self-tapping screws were implanted in rabbit calvarial bone models, and these indicated that SB-AH1 and SB-AH2 surfaces achieved better peri-implant bone formation and implant stability, while the SB-AH2 surface achieved the best percentage of bone-implant contact (BIC%). Our study demonstrated that the micro/nanotopographical surface generated by sandblasting and alkali heat treatment significantly enhanced preosteoblast proliferation, ALP activity and bone formation in vitro and in vivo, and nano-porous network topography may further induce better preosteoblast proliferation, ALP activity and BIC%.

Evolutionarily Conserved Epitopes on Human Immunodeficiency Virus Type 1 (HIV-1) and Feline Immunodeficiency Virus Reverse Transcriptases Detected by HIV-1-Infected Subjects

PubMed Central

Sanou, Missa P.; Roff, Shannon R.; Mennella, Antony; Sleasman, John W.; Rathore, Mobeen H.; Levy, Jay A.

2013-01-01

Anti-human immunodeficiency virus (HIV) cytotoxic T lymphocyte (CTL)-associated epitopes, evolutionarily conserved on both HIV type 1 (HIV-1) and feline immunodeficiency virus (FIV) reverse transcriptases (RT), were identified using gamma interferon (IFN-γ) enzyme-linked immunosorbent spot (ELISpot) and carboxyfluorescein diacetate succinimide ester (CFSE) proliferation assays followed by CTL-associated cytotoxin analysis. The peripheral blood mononuclear cells (PBMC) or T cells from HIV-1-seropositive (HIV+) subjects were stimulated with overlapping RT peptide pools. The PBMC from the HIV+ subjects had more robust IFN-γ responses to the HIV-1 peptide pools than to the FIV peptide pools, except for peptide-pool F3. In contrast, much higher and more frequent CD8+ T-cell proliferation responses were observed with the FIV peptide pools than with the HIV peptide pools. HIV-1-seronegative subjects had no proliferation or IFN-γ responses to the HIV and FIV peptide pools. A total of 24% (40 of 166) of the IFN-γ responses to HIV pools and 43% (23 of 53) of the CD8+ T-cell proliferation responses also correlated to responses to their counterpart FIV pools. Thus, more evolutionarily conserved functional epitopes were identified by T-cell proliferation than by IFN-γ responses. In the HIV+ subjects, peptide-pool F3, but not the HIV H3 counterpart, induced the most IFN-γ and proliferation responses. These reactions to peptide-pool F3 were highly reproducible and persisted over the 1 to 2 years of testing. All five individual peptides and epitopes of peptide-pool F3 induced IFN-γ and/or proliferation responses in addition to inducing CTL-associated cytotoxin responses (perforin, granzyme A, granzyme B). The epitopes inducing polyfunctional T-cell activities were highly conserved among human, simian, feline, and ungulate lentiviruses, which indicated that these epitopes are evolutionarily conserved. These results suggest that FIV peptides could be used in an HIV-1 vaccine. PMID:23824804

Conserved versatile master regulators in signalling pathways in response to stress in plants

PubMed Central

Balderas-Hernández, Victor E.; Alvarado-Rodríguez, Miguel; Fraire-Velázquez, Saúl

2013-01-01

From the first land plants to the complex gymnosperms and angiosperms of today, environmental conditions have forced plants to develop molecular strategies to surpass natural obstacles to growth and proliferation, and these genetic gains have been transmitted to the following generations. In this long natural process, novel and elaborate mechanisms have evolved to enable plants to cope with environmental limitations. Elements in many signalling cascades enable plants to sense different, multiple and simultaneous ambient cues. A group of versatile master regulators of gene expression control plant responses to stressing conditions. For crop breeding purposes, the task is to determine how to activate these key regulators to enable accurate and optimal reactions to common stresses. In this review, we discuss how plants sense biotic and abiotic stresses, how and which master regulators are implied in the responses to these stresses, their evolution in the life kingdoms, and the domains in these proteins that interact with other factors to lead to a proper and efficient plant response. PMID:24147216

Role of thrombopoietin in mast cell differentiation.

PubMed

Migliaccio, Anna Rita; Rana, Rosa Alba; Vannucchi, Alessandro M; Manzoli, Francesco A

2007-06-01

Mast cells are important elements of the body response to foreign antigens, being those represented either by small molecules (allergic response) or harbored by foreign microorganisms (response to parasite infection). These cells derive from hematopoietic stem/progenitor cells present in the marrow. However, in contrast with most of the other hematopoietic lineages, mast cells do not differentiate in the marrow but in highly vascularized extramedullary sites, such as the skin or the gut. Mast cell differentiation in the marrow is activated as part of the body response to parasites. We will review here the mast cell differentiation pathway and what is known of its major intrinsic and extrinsic control mechanisms. It will also be described that thrombopoietin, the ligand for the Mpl receptor, in addition to its pivotal rule in the control of thrombocytopoiesis and of hematopoietic stem/progenitor cell proliferation, exerts a regulatory function in mast cell differentiation. Some of the possible implications of this newly described biological activity of thrombopoietin will be discussed.

Cell Proliferation, Reactive Oxygen and Cellular Glutathione

PubMed Central

Day, Regina M.; Suzuki, Yuichiro J.

2005-01-01

A variety of cellular activities, including metabolism, growth, and death, are regulated and modulated by the redox status of the environment. A biphasic effect has been demonstrated on cellular proliferation with reactive oxygen species (ROS)—especially hydrogen peroxide and superoxide—in which low levels (usually submicromolar concentrations) induce growth but higher concentrations (usually >10–30 micromolar) induce apoptosis or necrosis. This phenomenon has been demonstrated for primary, immortalized and transformed cell types. However, the mechanism of the proliferative response to low levels of ROS is not well understood. Much of the work examining the signal transduction by ROS, including H2O2, has been performed using doses in the lethal range. Although use of higher ROS doses have allowed the identification of important signal transduction pathways, these pathways may be activated by cells only in association with ROS-induced apoptosis and necrosis, and may not utilize the same pathways activated by lower doses of ROS associated with increased cell growth. Recent data has shown that low levels of exogenous H2O2 up-regulate intracellular glutathione and activate the DNA binding activity toward antioxidant response element. The modulation of the cellular redox environment, through the regulation of cellular glutathione levels, may be a part of the hormetic effect shown by ROS on cell growth. PMID:18648617

Activin receptor inhibition by Smad2 regulates Drosophila wing disc patterning through BMP-response elements

PubMed Central

Peterson, Aidan J.; O'Connor, Michael B.

2013-01-01

Imaginal disc development in Drosophila requires coordinated cellular proliferation and tissue patterning. In our studies of TGFβ superfamily signaling components, we found that a protein null mutation of Smad2, the only Activin subfamily R-Smad in the fruit fly, produces overgrown wing discs that resemble gain of function for BMP subfamily signaling. The wing discs are expanded specifically along the anterior-posterior axis, with increased proliferation in lateral regions. The morphological defect is not observed in mutants for the TGFβ receptor baboon, and epistasis tests showed that baboon is epistatic to Smad2 for disc overgrowth. Rescue experiments indicate that Baboon binding, but not canonical transcription factor activity, of Smad2 is required for normal disc growth. Smad2 mutant discs generate a P-Mad stripe that is narrower and sharper than the normal gradient, and activation targets are correspondingly expressed in narrowed domains. Repression targets of P-Mad are profoundly mis-regulated, with brinker and pentagone reporter expression eliminated in Smad2 mutants. Loss of expression requires a silencer element previously shown to be controlled by BMP signaling. Epistasis experiments show that Baboon, Mad and Schnurri are required to mediate the ectopic silencer output in the absence of Smad2. Taken together, our results show that loss of Smad2 permits promiscuous Baboon activity, which represses genes subject to control by Mad-dependent silencer elements. The absence of Brinker and Pentagone in Smad2 mutants explains the compound wing disc phenotype. Our results highlight the physiological relevance of substrate inhibition of a kinase, and reveal a novel interplay between the Activin and BMP pathways. PMID:23293296

Avoiding Armageddon: The US Military’s Response to Trans-Regional Nuclear Proliferation in a Post-Soviet World

DTIC Science & Technology

2016-05-26

Post -Soviet World A Monograph by MAJ Andrew S. Glenn US Army School of Advanced Military Studies United States Army Command and General...2016 4. TITLE AND SUBTITLE Avoiding Armageddon: The US Military1s Response to Trans-Regional Nuclear Proliferation in a Post -Soviet World Sa...MAJ Andrew S. Glenn Monograph Title: Avoiding Armageddon: The US Military’s Response to Trans- Regional Nuclear Proliferation in a Post -Soviet

Novel DNA Motif Binding Activity Observed In Vivo With an Estrogen Receptor α Mutant Mouse

PubMed Central

Li, Leping; Grimm, Sara A.; Winuthayanon, Wipawee; Hamilton, Katherine J.; Pockette, Brianna; Rubel, Cory A.; Pedersen, Lars C.; Fargo, David; Lanz, Rainer B.; DeMayo, Francesco J.; Schütz, Günther; Korach, Kenneth S.

2014-01-01

Estrogen receptor α (ERα) interacts with DNA directly or indirectly via other transcription factors, referred to as “tethering.” Evidence for tethering is based on in vitro studies and a widely used “KIKO” mouse model containing mutations that prevent direct estrogen response element DNA- binding. KIKO mice are infertile, due in part to the inability of estradiol (E2) to induce uterine epithelial proliferation. To elucidate the molecular events that prevent KIKO uterine growth, regulation of the pro-proliferative E2 target gene Klf4 and of Klf15, a progesterone (P4) target gene that opposes the pro-proliferative activity of KLF4, was evaluated. Klf4 induction was impaired in KIKO uteri; however, Klf15 was induced by E2 rather than by P4. Whole uterine chromatin immunoprecipitation-sequencing revealed enrichment of KIKO ERα binding to hormone response elements (HREs) motifs. KIKO binding to HRE motifs was verified using reporter gene and DNA-binding assays. Because the KIKO ERα has HRE DNA-binding activity, we evaluated the “EAAE” ERα, which has more severe DNA-binding domain mutations, and demonstrated a lack of estrogen response element or HRE reporter gene induction or DNA-binding. The EAAE mouse has an ERα null–like phenotype, with impaired uterine growth and transcriptional activity. Our findings demonstrate that the KIKO mouse model, which has been used by numerous investigators, cannot be used to establish biological functions for ERα tethering, because KIKO ERα effectively stimulates transcription using HRE motifs. The EAAE-ERα DNA-binding domain mutant mouse demonstrates that ERα DNA-binding is crucial for biological and transcriptional processes in reproductive tissues and that ERα tethering may not contribute to estrogen responsiveness in vivo. PMID:24713037

Lithospermum erythrorhizon Root and its Naphthoquinones Repress SREBP1c and Activate PGC1α Through AMPKα.

PubMed

Velliquette, Rodney A; Rajgopal, Arun; Rebhun, John; Glynn, Kelly

2018-01-01

To examine specific molecular mechanisms involved in modulating hepatic lipogenesis and mitochondria biogenesis signals by Lithospermum erythrorhizon (gromwell) root extract. Stable cell lines with luciferase reporter constructs were generated to examine sterol regulatory element binding protein 1c (SREBP1c) and peroxisome proliferator-activated receptor gamma, coactivator 1 (PGC1) α promoter activity and estrogen-related receptor (ERR) α response element activity. Gene expression of SREBP1c, stearoyl coenzyme A desaturase 1, and PGC1α was measured by using reverse transcription polymerase chain reaction. Lipogenesis was measured in human hepatoma cells with Nile red staining and flow cytometry. Phosphorylation of AMP-activated protein kinase (AMPK) α was determined by using ELISA and Western blot. Gromwell root extract and its naphthoquinones dose-dependently repressed high glucose and liver X receptor α induction of SREBP1c promoter activity and gene expression. Hepatic lipogenesis was repressed, and PGC1α promoter and gene expression and ERRα response element activity were increased by gromwell root extract. Gromwell root extract, shikonin, and α-methyl-n-butyrylshikonin increased AMPKα phosphorylation, and inhibition of AMPK blunted the repression in SREBP1c promoter activity by gromwell root extract and its naphthoquinones. Data suggest that gromwell root extract and its naphthoquinones repress lipogenesis by increasing the phosphorylated state of AMPKα and stimulating mitochondrial biogenesis signals. © 2017 The Obesity Society.

Epigenetic Regulation of the NR4A Orphan Nuclear Receptor NOR1 By Histone Acetylation

PubMed Central

Zhao, Yue; Nomiyama, Takashi; Findeisen, Hannes M.; Qing, Hua; Aono, Jun; Jones, Karrie L.; Heywood, Elizabeth B.; Bruemmer, Dennis

2014-01-01

The nuclear receptor NOR1 is an immediate-early response gene implicated in the transcriptional control of proliferation. Since the expression level of NOR1 is rapidly induced through cAMP response element binding (CREB) protein-dependent promoter activation, we investigated the contribution of histone acetylation to this transient induction. We demonstrate that NOR1 transcription is induced by histone deacetylase (HDAC) inhibition and by depletion of HDAC1 and HDAC3. HDAC inhibition activated the NOR1 promoter, increased histone acetylation and augmented the recruitment of phosphorylated CREB to the promoter. Furthermore, HDAC inhibition increased Ser133 phosphorylation of CREB and augmented NOR1 protein stability. These data outline previously unrecognized mechanisms of NOR1 regulation and illustrate a key role for histone acetylation in the rapid induction of NOR1. PMID:25451221

A New Innovative Spherical Cermet Nuclear Fuel Element to Achieve an Ultra-Long Core Life for use in Grid-Appropriate LWRs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Senor, David J.; Painter, Chad L.; Geelhood, Ken J.

2007-12-01

Spherical cermet fuel elements are proposed for use in the Atoms For Peace Reactor (AFPR-100) concept. AFPR-100 is a small-scale, inherently safe, proliferation-resistant reactor that would be ideal for deployment to nations with emerging economies that decide to select nuclear power for the generation of carbon-free electricity. The basic concept of the AFPR core is a water-cooled fixed particle bed, randomly packed with spherical fuel elements. The flow of coolant within the particle bed is at such a low rate that the bed does not fluidize. This report summarizes an approach to fuel fabrication, results associated with fuel performance modeling,more » core neutronics and thermal hydraulics analyses demonstrating a ~20 year core life, and a conclusion that the proliferation resistance of the AFPR reactor concept is high.« less

Nezha, a novel active miniature inverted-repeat transposable element in cyanobacteria

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou Fengfeng; Tran Thao; Xu Ying

2008-01-25

Miniature inverted-repeat transposable elements (MITEs) were first identified in plants and exerted extensive proliferations throughout eukaryotic and archaeal genomes. But very few MITEs have been characterized in bacteria. We identified a novel MITE, called Nezha, in cyanobacteria Anabaena variabilis ATCC 29413 and Nostoc sp. PCC 7120. Nezha, like most previously known MITEs in other organisms, is small in size, non-coding, carrying TIR and DR signals, and of potential to form a stable RNA secondary structure, and it tends to insert into A+T-rich regions. Recent transpositions of Nezha were observed in A. variabilis ATCC 29413 and Nostoc sp. PCC 7120, respectively.more » Nezha might have proliferated recently with aid from the transposase encoded by ISNpu3-like elements. A possible horizontal transfer event of Nezha from cyanobacteria to Polaromonas JS666 is also observed.« less

Airway epithelial cell PPARγ modulates cigarette smoke-induced chemokine expression and emphysema susceptibility in mice.

PubMed

Solleti, Siva Kumar; Simon, Dawn M; Srisuma, Sorachai; Arikan, Meltem C; Bhattacharya, Soumyaroop; Rangasamy, Tirumalai; Bijli, Kaiser M; Rahman, Arshad; Crossno, Joseph T; Shapiro, Steven D; Mariani, Thomas J

2015-08-01

Chronic obstructive pulmonary disease (COPD) is a highly prevalent, chronic inflammatory lung disease with limited existing therapeutic options. While modulation of peroxisome proliferator-activating receptor (PPAR)-γ activity can modify inflammatory responses in several models of lung injury, the relevance of the PPARG pathway in COPD pathogenesis has not been previously explored. Mice lacking Pparg specifically in airway epithelial cells displayed increased susceptibility to chronic cigarette smoke (CS)-induced emphysema, with excessive macrophage accumulation associated with increased expression of chemokines, Ccl5, Cxcl10, and Cxcl15. Conversely, treatment of mice with a pharmacological PPARγ activator attenuated Cxcl10 and Cxcl15 expression and macrophage accumulation in response to CS. In vitro, CS increased lung epithelial cell chemokine expression in a PPARγ activation-dependent fashion. The ability of PPARγ to regulate CS-induced chemokine expression in vitro was not specifically associated with peroxisome proliferator response element (PPRE)-mediated transactivation activity but was correlated with PPARγ-mediated transrepression of NF-κB activity. Pharmacological or genetic activation of PPARγ activity abrogated CS-dependent induction of NF-κB activity. Regulation of NF-κB activity involved direct PPARγ-NF-κB interaction and PPARγ-mediated effects on IKK activation, IκBα degradation, and nuclear translocation of p65. Our data indicate that PPARG represents a disease-relevant pathophysiological and pharmacological target in COPD. Its activation state likely contributes to NF-κB-dependent, CS-induced chemokine-mediated regulation of inflammatory cell accumulation.

Paradoxical Regulation of Human FGF21 by Both Fasting and Feeding Signals: Is FGF21 a Nutritional Adaptation Factor?

PubMed Central

Uebanso, Takashi; Taketani, Yutaka; Yamamoto, Hironori; Amo, Kikuko; Ominami, Hirokazu; Arai, Hidekazu; Takei, Yuichiro; Masuda, Masashi; Tanimura, Ayako; Harada, Nagakatsu; Yamanaka-Okumura, Hisami; Takeda, Eiji

2011-01-01

Fibroblast growth factor 21 (FGF21) has recently emerged as a metabolic hormone involved in regulating glucose and lipid metabolism in mouse, but the regulatory mechanisms and actions of FGF21 in humans remain unclear. Here we have investigated the regulatory mechanisms of the human FGF21 gene at the transcriptional level. A deletion study of the human FGF21 promoter (−1672 to +230 bp) revealed two fasting signals, including peroxisome proliferator-activated receptor α (PPARα) and glucagon signals, that independently induced human FGF21 gene transcription in mouse primary hepatocytes. In addition, two feeding signals, glucose and xylitol, also dose-dependently induced human FGF21 gene transcription and mRNA expression in both human HepG2 cells and mouse primary hepatocytes. FGF21 protein expression and secretion were also induced by high glucose stimulation. The human FGF21 promoter (−1672 to +230 bp) was found to have a carbohydrate-responsive element at −380 to −366 bp, which is distinct from the PPAR response element (PPRE). Knock-down of the carbohydrate response element binding protein by RNAi diminished glucose-induced human FGF21 transcription. Moreover, we found that a region from −555 to −443 bp of the human FGF21 promoter region exerts an important role in the activation of basic transcription. In conclusion, human FGF21 gene expression is paradoxically and independently regulated by both fasting and feeding signals. These regulatory mechanisms suggest that human FGF21 is increased with nutritional crisis, including starvation and overfeeding. PMID:21829679

NF-kappaB specifically activates BMP-2 gene expression in growth plate chondrocytes in vivo and in a chondrocyte cell line in vitro.

PubMed

Feng, Jian Q; Xing, Lianping; Zhang, Jiang-Hong; Zhao, Ming; Horn, Diane; Chan, Jeannie; Boyce, Brendan F; Harris, Stephen E; Mundy, Gregory R; Chen, Di

2003-08-01

Bone morphogenetic protein-2 (BMP-2) regulates growth plate chondrogenesis during development and postnatal bone growth, but the control mechanisms of BMP-2 expression in growth plate chondrocytes are unknown. Here we have used both in vitro and in vivo approaches to demonstrate that transcription factor, NF-kappaB, regulates BMP-2 gene expression in chondrocytes. Two putative NF-kappaB response elements were found in the -2712/+165 region of the BMP-2 gene. Cotransfection of mutant I-kappaBalpha expression plasmids with BMP-2 promoter-luciferase reporters into TMC-23 chondrocyte cell line suppressed BMP-2 transcription. Mutations in NF-kappaB response elements in the BMP-2 gene lead to decreases in BMP-2 promoter activity. Electrophoretic mobility shift assay using nuclear extracts from TMC-23 chondrocytic cells revealed that the NF-kappaB subunits p50 and p65 bound to the NF-kappaB response elements of the BMP-2 gene. Thus, NF-kappaB may positively regulate BMP-2 gene transcription. Consistent with these findings, expression of BMP-2 mRNA was significantly reduced in growth plate chondrocytes in NF-kappaB p50/p52 dKO mice, which associated with decreased numbers of 5-bromo-2'-deoxyuridine (BrdUrd)-positive cells in the proliferating zone of growth plate in these mice. Therefore, in postnatal growth plate chondrocytes, expression of BMP-2 is regulated by NF-kappaB, which may play an important role in chondrogenesis.

Berberine Suppresses Adipocyte Differentiation via Decreasing CREB Transcriptional Activity

PubMed Central

Deng, Ruyuan; Wang, Ning; Zhang, Yuqing; Wang, Yao; Liu, Yun; Li, Fengying; Wang, Xiao; Zhou, Libin

2015-01-01

Berberine, one of the major constituents of Chinese herb Rhizoma coptidis, has been demonstrated to lower blood glucose, blood lipid, and body weight in patients with type 2 diabetes mellitus. The anti-obesity effect of berberine has been attributed to its anti-adipogenic activity. However, the underlying molecular mechanism remains largely unknown. In the present study, we found that berberine significantly suppressed the expressions of CCAAT/enhancer-binding protein (C/EBP)α, peroxisome proliferators-activated receptor γ2 (PPARγ2), and other adipogenic genes in the process of adipogenesis. Berberine decreased cAMP-response element-binding protein (CREB) phosphorylation and C/EBPβ expression at the early stage of 3T3-L1 preadipocyte differentiation. In addition, CREB phosphorylation and C/EBPβ expression induced by 3-isobutyl-1-methylxanthine (IBMX) and forskolin were also attenuated by berberine. The binding activities of cAMP responsive element (CRE) stimulated by IBMX and forskolin were inhibited by berberine. The binding of phosphorylated CREB to the promoter of C/EBPβ was abrogated by berberine after the induction of preadipocyte differentiation. These results suggest that berberine blocks adipogenesis mainly via suppressing CREB activity, which leads to a decrease in C/EBPβ-triggered transcriptional cascades. PMID:25928058

Resveratrol Inhibits the Proliferation of Neural Progenitor Cells and Hippocampal Neurogenesis*

PubMed Central

Park, Hee Ra; Kong, Kyoung Hye; Yu, Byung Pal; Mattson, Mark P.; Lee, Jaewon

2012-01-01

Resveratrol is a phytoalexin and natural phenol that is present at relatively high concentrations in peanuts and red grapes and wine. Based upon studies of yeast and invertebrate models, it has been proposed that ingestion of resveratrol may also have anti-aging actions in mammals including humans. It has been suggested that resveratrol exerts its beneficial effects on health by activating the same cellular signaling pathways that are activated by dietary energy restriction (DR). Some studies have reported therapeutic actions of resveratrol in animal models of metabolic and neurodegenerative disorders. However, the effects of resveratrol on cell, tissue and organ function in healthy subjects are largely unknown. In the present study, we evaluated the potential effects of resveratrol on the proliferation and survival of neural progenitor cells (NPCs) in culture, and in the hippocampus of healthy young adult mice. Resveratrol reduced the proliferation of cultured mouse multi-potent NPCs, and activated AMP-activated protein kinase (AMPK), in a concentration-dependent manner. Administration of resveratrol to mice (1–10 mg/kg) resulted in activation of AMPK, and reduced the proliferation and survival of NPCs in the dentate gyrus of the hippocampus. Resveratrol down-regulated the levels of the phosphorylated form of cyclic AMP response element-binding protein (pCREB) and brain-derived neurotrophic factor (BDNF) in the hippocampus. Finally, resveratrol-treated mice exhibited deficits in hippocampus-dependent spatial learning and memory. Our findings suggest that resveratrol, unlike DR, adversely affects hippocampal neurogenesis and cognitive function by a mechanism involving activation of AMPK and suppression of CREB and BDNF signaling. PMID:23105098

Antioxidative Dietary Compounds Modulate Gene Expression Associated with Apoptosis, DNA Repair, Inhibition of Cell Proliferation and Migration

PubMed Central

Wang, Likui; Gao, Shijuan; Jiang, Wei; Luo, Cheng; Xu, Maonian; Bohlin, Lars; Rosendahl, Markus; Huang, Wenlin

2014-01-01

Many dietary compounds are known to have health benefits owing to their antioxidative and anti-inflammatory properties. To determine the molecular mechanism of these food-derived compounds, we analyzed their effect on various genes related to cell apoptosis, DNA damage and repair, oxidation and inflammation using in vitro cell culture assays. This review further tests the hypothesis proposed previously that downstream products of COX-2 (cyclooxygenase-2) called electrophilic oxo-derivatives induce antioxidant responsive elements (ARE), which leads to cell proliferation under antioxidative conditions. Our findings support this hypothesis and show that cell proliferation was inhibited when COX-2 was down-regulated by polyphenols and polysaccharides. Flattened macrophage morphology was also observed following the induction of cytokine production by polysaccharides extracted from viili, a traditional Nordic fermented dairy product. Coix lacryma-jobi (coix) polysaccharides were found to reduce mitochondrial membrane potential and induce caspase-3- and 9-mediated apoptosis. In contrast, polyphenols from blueberries were involved in the ultraviolet-activated p53/Gadd45/MDM2 DNA repair system by restoring the cell membrane potential. Inhibition of hypoxia-inducible factor-1 by saponin extracts of ginsenoside (Ginsen) and Gynostemma and inhibition of S100A4 by coix polysaccharides inhibited cancer cell migration and invasion. These observations suggest that antioxidants and changes in cell membrane potential are the major driving forces that transfer signals through the cell membrane into the cytosol and nucleus, triggering gene expression, changes in cell proliferation and the induction of apoptosis or DNA repair. PMID:25226533

Estrogen improves the proliferation and differentiation of hBMSCs derived from postmenopausal osteoporosis through notch signaling pathway.

PubMed

Fan, Jin-Zhu; Yang, Liu; Meng, Guo-Lin; Lin, Yan-shui; Wei, Bo-Yuan; Fan, Jing; Hu, Hui-Min; Liu, Yan-Wu; Chen, Shi; Zhang, Jin-Kang; He, Qi-Zhen; Luo, Zhuo-Jing; Liu, Jian

2014-07-01

Estrogen deficiency is the main reason of bone loss, leading to postmenopausal osteoporosis, and estrogen replacement therapy (ERT) has been demonstrated to protect bone loss efficiently. Notch signaling controls proliferation and differentiation of bone marrow-derived mesenchymal stem cells (BMSCs). Moreover, imperfect estrogen-responsive elements (EREs) were found in the 5'-untranslated region of Notch1 and Jagged1. Thus, we examined the molecular and biological links between estrogen and the Notch signaling in postmenopausal osteoporosis in vitro. hBMSCs were obtained from healthy women and patients with postmenopausal osteoporosis. Notch signaling molecules were quantified using real-time polymerase chain reaction (real-time PCR) and Western Blot. Luciferase reporter constructs with putative EREs were transfected into hBMSCs and analyzed. hBMSCs were transduced with lentiviral vectors containing human Notch1 intracellular domain (NICD1). We also used N-[N-(3, 5-diflurophenylacetate)-l-alanyl]-(S)-phenylglycine t-butyl ester, a γ-secretase inhibitor, to suppress the Notch signaling. We found that estrogen enhanced the Notch signaling in hBMSCs by promoting the expression of Jagged1. hBMSCs cultured with estrogen resulted in the up-regulation of Notch signaling and increased proliferation and differentiation. Enhanced Notch signaling could enhance the proliferation and differentiation of hBMSCs from patients with postmenopausal osteoporosis (OP-hBMSCs). Our results demonstrated that estrogen preserved bone mass partly by activating the Notch signaling. Because long-term ERT has been associated with several side effects, the Notch signaling could be a potential target for treating postmenopausal osteoporosis.

Nitrophenols isolated from diesel exhaust particles promote the growth of MCF-7 breast adenocarcinoma cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Furuta, Chie; Laboratory of Veterinary Physiology, Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509; Suzuki, Akira K.

2008-08-01

Diesel exhaust particles (DEPs) cause many adverse health problems, and reports indicate increased risk of breast cancer in men and women through exposure to gasoline and vehicle exhaust. However, DEPs include vast numbers of compounds, and the specific compound(s) responsible for these actions are not clear. We recently isolated two nitrophenols from DEPs-3-methyl-4-nitrophenol (4-nitro-m-cresol; PNMC) and 4-nitro-3-phenylphenol (PNMPP)-and showed that they had estrogenic and anti-androgenic activities. Here, we tried to clarify the involvement of these two nitrophenols in promoting the growth of the MCF-7 breast cancer cell line. First, comet assay was used to detect the genotoxicity of PNMC andmore » PNMPP in a CHO cell line. At all doses tested, PNMC and PNMPP showed negative genotoxicity, indicating that they had no tumor initiating activity. Next, the estrogen-responsive breast cancer cell line MCF-7 was used to assess cell proliferation. Proliferation of MCF-7 cells was stimulated by PNMC, PNMPP, and estradiol-17{beta} and the anti-estrogens 4-hydroxytamoxifen and ICI 182,780 inhibited the proliferation. To further investigate transcriptional activity through the estrogen receptor, MCF-7 cells were transfected with a receptor gene that allowed expression of luciferase enzyme under the control of the estrogen regulatory element. PNMC and PNMPP induced luciferase activity in a dose-dependent manner at submicromolar concentrations. ICI 182,780 inhibited the luciferase activity induced by PNMC and PNMPP. These results clearly indicate that PNMC and PNMPP do not show genotoxicity but act as tumor promoters in an estrogen receptor {alpha}-predominant breast cancer cell line.« less

Regenerative response following stab injury in the adult zebrafish telencephalon.

PubMed

März, Martin; Schmidt, Rebecca; Rastegar, Sepand; Strähle, Uwe

2011-09-01

In contrast to mammals, the brain of the adult zebrafish has a remarkable ability to regenerate. In mammals, injuries induce proliferation of astrocytes and oligodendrocyte progenitors contributing to the formation of a glial scar. We analyzed the proliferation of glial cells and microglia in response to stab injury in the adult zebrafish telencephalon: Radial glial markers were up-regulated at the ventricle and co-expressed the proliferation nuclear antigen (PCNA). Microglia and oligodendrocyte progenitors accumulated transiently at the site of lesion. However, we could not find evidence of permanent scar formation. Parenchymal proliferation was almost negligible in comparison to the increase in proliferation at the ventricular zone. This suggests that most of the cellular material for regeneration is derived from regions of constitutive neurogenesis. Remarkably, the proliferative response is almost completely restricted to the lesioned hemisphere indicating that signals inducing regeneration remain mainly confined within the lesioned half of the telencephalon. Copyright © 2011 Wiley-Liss, Inc.

The effect of burn injury on CD8+ and CD4+ T cells in an irradiation model of homeostatic proliferation.

PubMed

Buchanan, Ian B; Maile, Robert; Frelinger, Jeffrey A; Fair, Jeffrey H; Meyer, Anthony A; Cairns, Bruce A

2006-11-01

Homeostatic proliferation of T cells has recently been shown to be an important mechanism in the host response to infection. However, its role in the T cell response to burn injury is unknown. In this study, we examine the effect of burn injury on CD4+ and CD8+ T cell homeostatic proliferation after irradiation. Wild-type C57BL/6 female mice were irradiated with six grays ionizing radiation and 48 hours later, syngeneic whole splenocytes or purified CD4+ or CD8+ T cells labeled with carboxy-fluorescein diacetate, succinimidyl ester were adoptively transferred. Two days later, mice underwent a 20% burn injury, followed by splenocyte harvest 3 and 10 days after injury. Burn mice demonstrate increased splenic cellularity and CD8+ T cell proliferation after adoptive transfer of either purified CD8+ cells or whole spleen populations compared with unburned (sham) mice. In contrast, CD4+ T cell proliferation after burn injury is unchanged after adoptive transfer of whole spleen cells and drastically decreased after adoptive transfer of a purified CD4+ population compared with sham mice. Ten days after burn injury CD8+ T cells continue to demonstrate greater proliferation than CD4+ T cells. CD8+ T cells are more robust than CD4+ T cells in their proliferative response after burn injury. In addition, CD8+ T cell proliferation appears less reliant on other immune cells than purified CD4+ T cell proliferation. These data reiterate the importance of CD8+ T cells in the initial immune response to burn injury.

Quiescence does not affect p53 and stress response by irradiation in human lung fibroblasts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dai, Jiawen; Itahana, Koji, E-mail: koji.itahana@duke-nus.edu.sg; Baskar, Rajamanickam, E-mail: r.baskar@nccs.com.sg

Cells in many organs exist in both proliferating and quiescent states. Proliferating cells are more radio-sensitive, DNA damage pathways including p53 pathway are activated to undergo either G{sub 1}/S or G{sub 2}/M arrest to avoid entering S and M phase with DNA damage. On the other hand, quiescent cells are already arrested in G{sub 0}, therefore there may be fundamental difference of irradiation response between proliferating and quiescent cells, and this difference may affect their radiosensitivity. To understand these differences, proliferating and quiescent human normal lung fibroblasts were exposed to 0.10–1 Gy of γ-radiation. The response of key proteins involvedmore » in the cell cycle, cell death, and metabolism as well as histone H2AX phosphorylation were examined. Interestingly, p53 and p53 phosphorylation (Ser-15), as well as the cyclin-dependent kinase inhibitors p21 and p27, were induced similarly in both proliferating and quiescent cells after irradiation. Furthermore, the p53 protein half-life, and expression of cyclin A, cyclin E, proliferating cell nuclear antigen (PCNA), Bax, or cytochrome c expression as well as histone H2AX phosphorylation were comparable after irradiation in both phases of cells. The effect of radioprotection by a glycogen synthase kinase 3β inhibitor on p53 pathway was also similar between proliferating and quiescent cells. Our results showed that quiescence does not affect irradiation response of key proteins involved in stress and DNA damage at least in normal fibroblasts, providing a better understanding of the radiation response in quiescent cells, which is crucial for tissue repair and regeneration. - Highlights: • p53 response by irradiation was similar between proliferating and quiescent cells. • Quiescent cells showed similar profiles of cell cycle proteins after irradiation. • Radioprotection of GSK-3β inhibitor caused similar effects between these cells. • Quiescence did not affect p53 response despite its known role in radio-resistance.« less

p53 in survival, death and metabolic health: a lifeguard with a licence to kill.

PubMed

Kruiswijk, Flore; Labuschagne, Christiaan F; Vousden, Karen H

2015-07-01

The function of p53 as a tumour suppressor has been attributed to its ability to promote cell death or permanently inhibit cell proliferation. However, in recent years, it has become clear that p53 can also contribute to cell survival. p53 regulates various metabolic pathways, helping to balance glycolysis and oxidative phosphorylation, limiting the production of reactive oxygen species, and contributing to the ability of cells to adapt to and survive mild metabolic stresses. Although these activities may be integrated into the tumour suppressive functions of p53, deregulation of some elements of the p53-induced response might also provide tumours with a survival advantage.

A Prescription for Cultural Competence in Medical Education

PubMed Central

Kripalani, Sunil; Bussey-Jones, Jada; Katz, Marra G; Genao, Inginia

2006-01-01

Cultural competence programs have proliferated in U.S. medical schools in response to increasing national diversity, as well as mandates from accrediting bodies. Although such training programs share common goals of improving physician-patient communication and reducing health disparities, they often differ in their content, emphasis, setting, and duration. Moreover, training in cross-cultural medicine may be absent from students' clinical rotations, when it might be most relevant and memorable. In this article, the authors recommend a number of elements to strengthen cultural competency education in medical schools. This “prescription for cultural competence” is intended to promote an active and integrated approach to multicultural issues throughout medical school training. PMID:16836623

Foxp1 Regulates the Proliferation of Hair Follicle Stem Cells in Response to Oxidative Stress during Hair Cycling

PubMed Central

Zhao, Jianzhi; Li, Hanjun; Zhou, Rujiang; Ma, Gang; Dekker, Joseph D.; Tucker, Haley O.; Yao, Zhengju; Guo, Xizhi

2015-01-01

Hair follicle stem cells (HFSCs) in the bugle circularly generate outer root sheath (ORS) through linear proliferation within limited cycles during anagen phases. However, the mechanisms controlling the pace of HFSC proliferation remain unclear. Here we revealed that Foxp1, a transcriptional factor, was dynamically relocated from the nucleus to the cytoplasm of HFSCs in phase transitions from anagen to catagen, coupled with the rise of oxidative stress. Mass spectrum analyses revealed that the S468 phosphorylation of Foxp1 protein was responsive to oxidative stress and affected its nucleocytoplasmic translocation. Foxp1 deficiency in hair follicles led to compromised ROS accrual and increased HFSC proliferation. And more, NAC treatment profoundly elongated the anagen duration and HFSC proliferation in Foxp1-deficient background. Molecularly, Foxp1 augmented ROS levels through suppression of Trx1-mediated reductive function, thereafter imposing the cell cycle arrest by modulating the activity of p19/p53 pathway. Our findings identify a novel role for Foxp1 in controlling HFSC proliferation with cellular dynamic location in response to oxidative stress during hair cycling. PMID:26171970

Effect of interleukins on the proliferation and survival of B cell chronic lymphocytic leukaemia cells.

PubMed Central

Mainou-Fowler, T; Copplestone, J A; Prentice, A G

1995-01-01

AIMS--To investigate the effects of interleukin (IL) 1, 2, 4, and 5 on the proliferation and survival of peripheral blood B cells from patients with B chronic lymphocytic leukaemia (B-CLL) and compare them with the effects on normal peripheral blood B cells. METHODS--The proliferation and survival of pokeweed mitogen (PWM) activated B cells from B-CLL (n = 12) and normal peripheral blood (n = 5) were studied in vitro in response to IL-1, IL-2 IL-4, and IL-5. Survival of cells in cultures with or without added interleukins was studied by microscopic examination of cells and DNA agarose gel electrophoresis. RESULTS--Proliferation was observed in both B-CLL and normal peripheral blood cells on culture with IL-2 alone and also in some, but not all, B-CLL and normal peripheral blood cells with IL-1 and IL-4. However, there was greater variability in B-CLL cell responses than in normal peripheral blood cells. Il-5 did not affect normal peripheral blood cell proliferation but it increased proliferation in two B-CLL cases. Synergistic effects of these cytokines were not detected. IL-4 inhibited normal peripheral blood and B-CLL cell proliferation after the addition of IL-2. Inhibition of B-CLL cell responses to IL-2 was also observed with IL-5 and Il-1. Survival of B-CLL cells in cultures was enhanced with IL-4 not by an increase in proliferation but by reduced apoptosis. No such effect was seen in normal peripheral blood cells. IL-2 had a less noticeable antiapoptotic effect; IL-5 enhanced apoptosis in B-CLL cells. CONCLUSIONS--B-CLL and normal peripheral blood cells proliferated equally well in response to IL-2. IL-4 had a much lower effect on B-CLL cell proliferation, but had noticeable antiapoptotic activity. IL-5 enhanced cell death by apoptosis. Images PMID:7629299

Diversification, phylogeny and evolution of auxin response factor (ARF) family: insights gained from analyzing maize ARF genes.

PubMed

Wang, Yijun; Deng, Dexiang; Shi, Yating; Miao, Nan; Bian, Yunlong; Yin, Zhitong

2012-03-01

Auxin response factors (ARFs), member of the plant-specific B3 DNA binding superfamily, target specifically to auxin response elements (AuxREs) in promoters of primary auxin-responsive genes and heterodimerize with Aux/IAA proteins in auxin signaling transduction cascade. In previous research, we have isolated and characterized maize Aux/IAA genes in whole-genome scale. Here, we report the comprehensive analysis of ARF genes in maize. A total of 36 ARF genes were identified and validated from the B73 maize genome through an iterative strategy. Thirty-six maize ARF genes are distributed in all maize chromosomes except chromosome 7. Maize ARF genes expansion is mainly due to recent segmental duplications. Maize ARF proteins share one B3 DNA binding domain which consists of seven-stranded β sheets and two short α helixes. Twelve maize ARFs with glutamine-rich middle regions could be as activators in modulating expression of auxin-responsive genes. Eleven maize ARF proteins are lack of homo- and heterodimerization domains. Putative cis-elements involved in phytohormones and light signaling responses, biotic and abiotic stress adaption locate in promoters of maize ARF genes. Expression patterns vary greatly between clades and sister pairs of maize ARF genes. The B3 DNA binding and auxin response factor domains of maize ARF proteins are primarily subjected to negative selection during selective sweep. The mixed selective forces drive the diversification and evolution of genomic regions outside of B3 and ARF domains. Additionally, the dicot-specific proliferation of ARF genes was detected. Comparative genomics analysis indicated that maize, sorghum and rice duplicate chromosomal blocks containing ARF homologs are highly syntenic. This study provides insights into the distribution, phylogeny and evolution of ARF gene family.

Regenerative responses after mild heart injuries for cardiomyocyte proliferation in zebrafish

PubMed Central

Itou, Junji; Akiyama, Ryutaro; Pehoski, Steve; Yu, Xiaodan; Kawakami, Hiroko; Kawakami, Yasuhiko

2014-01-01

Background The zebrafish heart regenerates after various severe injuries. Common processes of heart regeneration are cardiomyocyte proliferation, activation of epicardial tissue and neovascularization. In order to further characterize heart regeneration processes, we introduced milder injuries and compared responses to those induced by ventricular apex resection, a widely used injury method. We used scratching of the ventricular surface and puncturing of the ventricle with a fine tungsten needle as injury inducing techniques. Results Scratching the ventricular surface induced subtle cardiomyocyte proliferation and responses of the epicardium. Endothelial cell accumulation was limited to the surface of the heart. Ventricular puncture induced cardiomyocyte proliferation, endocardial and epicardial activation and neo-vascularization, similar to the resection method. However, the degree of the responses was milder, correlating with milder injury. Sham operation induced epicardial aldh1a2 expression but not tbx18 and WT1. Conclusions Puncturing the ventricle induces responses equivalent to resection at milder degrees in a shorter time frame and would be used as simple injury model. Scratching the ventricle did not induce heart regeneration and would be used for studying wound responses to epicardium. PMID:25074230

Nucleolus-derived mediators in oncogenic stress response and activation of p53-dependent pathways.

PubMed

Stępiński, Dariusz

2016-08-01

Rapid growth and division of cells, including tumor ones, is correlated with intensive protein biosynthesis. The output of nucleoli, organelles where translational machineries are formed, depends on a rate of particular stages of ribosome production and on accessibility of elements crucial for their effective functioning, including substrates, enzymes as well as energy resources. Different factors that induce cellular stress also often lead to nucleolar dysfunction which results in ribosome biogenesis impairment. Such nucleolar disorders, called nucleolar or ribosomal stress, usually affect cellular functioning which in fact is a result of p53-dependent pathway activation, elicited as a response to stress. These pathways direct cells to new destinations such as cell cycle arrest, damage repair, differentiation, autophagy, programmed cell death or aging. In the case of impaired nucleolar functioning, nucleolar and ribosomal proteins mediate activation of the p53 pathways. They are also triggered as a response to oncogenic factor overexpression to protect tissues and organs against extensive proliferation of abnormal cells. Intentional impairment of any step of ribosome biosynthesis which would direct the cells to these destinations could be a strategy used in anticancer therapy. This review presents current knowledge on a nucleolus, mainly in relation to cancer biology, which is an important and extremely sensitive element of the mechanism participating in cellular stress reaction mediating activation of the p53 pathways in order to counteract stress effects, especially cancer development.

Sinensetin enhances adipogenesis and lipolysis by increasing cyclic adenosine monophosphate levels in 3T3-L1 adipocytes.

PubMed

Kang, Seong-Il; Shin, Hye-Sun; Kim, Se-Jae

2015-01-01

Sinensetin is a rare polymethoxylated flavone (PMF) found in certain citrus fruits. In this study, we investigated the effects of sinensetin on lipid metabolism in 3T3-L1 cells. Sinensetin promoted adipogenesis in 3T3-L1 preadipocytes growing in incomplete differentiation medium, which did not contain 3-isobutyl-1-methylxanthine. Sinensetin up-regulated expression of the adipogenic transcription factors peroxisome proliferator-activated receptor γ, CCAAT/enhancer-binding protein (C/EBP) α, and sterol regulatory element-binding protein 1c. It also potentiated expression of C/EBPβ and activation of cAMP-responsive element-binding protein. Sinensetin enhanced activation of protein kinase A and increased intracellular cAMP levels in 3T3-L1 preadipocytes. In mature 3T3-L1 adipocytes, sinensetin stimulated lipolysis via a cAMP pathway. Taken together, these results suggest that sinensetin enhances adipogenesis and lipolysis by increasing cAMP levels in adipocytes.

Epigenetic regulation of the NR4A orphan nuclear receptor NOR1 by histone acetylation.

PubMed

Zhao, Yue; Nomiyama, Takashi; Findeisen, Hannes M; Qing, Hua; Aono, Jun; Jones, Karrie L; Heywood, Elizabeth B; Bruemmer, Dennis

2014-12-20

The nuclear receptor NOR1 is an immediate-early response gene implicated in the transcriptional control of proliferation. Since the expression level of NOR1 is rapidly induced through cAMP response element binding (CREB) protein-dependent promoter activation, we investigated the contribution of histone acetylation to this transient induction. We demonstrate that NOR1 transcription is induced by histone deacetylase (HDAC) inhibition and by depletion of HDAC1 and HDAC3. HDAC inhibition activated the NOR1 promoter, increased histone acetylation and augmented the recruitment of phosphorylated CREB to the promoter. Furthermore, HDAC inhibition increased Ser133 phosphorylation of CREB and augmented NOR1 protein stability. These data outline previously unrecognized mechanisms of NOR1 regulation and illustrate a key role for histone acetylation in the rapid induction of NOR1. Copyright © 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

MC3T3-E1 cell response of amorphous phase/TiO2 nanocrystal composite coating prepared by microarc oxidation on titanium.

PubMed

Zhou, Rui; Wei, Daqing; Yang, Haoyue; Feng, Wei; Cheng, Su; Li, Baoqiang; Wang, Yaming; Jia, Dechang; Zhou, Yu

2014-06-01

Bioactive amorphous phase/TiO2 nanocrystal (APTN) composite coatings were fabricated by microarc oxidation (MAO) on Ti. The APTN coatings are composed of much amorphous phase with Si, Na, Ca, Ti and O elements and a few TiO2 nanocrystals. With increasing applied voltage, the micropore density of the APTN coating decreases and the micropore size of the APTN coating increases. The results indicate that less MC3T3-E1 cells attach on the APTN coatings as compared to Ti. However, the APTN coatings greatly enhance the cell proliferation ability and the activity of alkaline phosphatase. The amorphous phase and the concentrations of the released Ca and Si from the APTN coatings during cell culture have significant effects on the cell response. Copyright © 2014 Elsevier B.V. All rights reserved.

Pharmacological mimicking of caloric restriction elicits epigenetic reprogramming of differentiated cells to stem-like self-renewal states.

PubMed

Oliveras-Ferraros, Cristina; Vazquez-Martin, Alejandro; Menendez, Javier A

2010-10-01

Networks of oncogenes and tumor suppressor genes that control cancer cell proliferation also regulate stem cell renewal and possibly stem cell aging. Because (de)differentiation processes might dictate tumor cells to retrogress to a more stem-like state in response to aging-relevant epigenetic and/or environmental players, we recently envisioned that cultured human cancer cells might be used as reliable models to test the ability of antiaging interventions for promoting the initiation and maintenance of self-renewing divisions. Cancer cell lines naturally bearing undetectable amounts of stem/progenitor-like cell populations were continuously cultured in the presence of the caloric restriction mimetic metformin for several months. Microarray technology was employed to profile expression of genes related to the identification, growth, and differentiation of stem cells. Detection of functionally related gene groups using a pathway analysis package provided annotated genetic signatures over- and underexpressed in response to pharmacological mimicking of caloric restriction. By following this methodological approach, we recently obtained data fitting a model in which, in response to chronic impairment of cellular bioenergetics imposed by metformin-induced mitochondrial uncoupling as assessed by the phosphorylation state of cAMP-response element binding protein (CREB), tumor cells can retrogress from a differentiated state to a more CD44(+) stem-like primitive state epigenetically governed by the Polycomb-group suppressor BMI1-a crucial "stemness" gene involved in the epigenetic maintenance of adult stem cells. These findings might provide a novel molecular avenue to investigate if antiaging benefits from caloric restriction mimetics might relate to their ability to epigenetically reprogram stemness while prolonging the capacity of stem-like cell states to proliferate, differentiate, and replace mature cells in adult aging tissues.

Nicotine suppresses bone sialoprotein gene expression.

PubMed

Nakayama, Y; Mezawa, M; Araki, S; Sasaki, Y; Wang, S; Han, J; Li, X; Takai, H; Ogata, Y

2009-10-01

Tobacco smoking is a risk factor for periodontitis and osteoporosis. Nicotine is a major component of tobacco, and has been reported to inhibit proliferation and differentiation of osteoblasts. Bone sialoprotein (BSP) is a mineralized tissue-specific protein expressed by differentiated osteoblasts that appears to function in the initial mineralization of bone. The purpose of this study was to determine the effects of nicotine on bone metabolism. We used rat osteobast-like UMR106 and ROS 17/2.8 cells and rat stromal bone marrow RBMC-D8 cells. To determine the molecular basis of the transcriptional regulation of the BSP gene by nicotine, we conducted Northern hybridization, transient transfection analyses with chimeric constructs of the BSP gene promoter linked to a luciferase reporter gene and gel mobility shift assays. Nicotine (250 microg/mL) decreased the BSP mRNA levels at 12 and 24 h in UMR106 and ROS 17/2.8 cells. From transient transfection assays using various sized BSP promoter-luciferase constructs, nicotine decreased the luciferase activities of the construct, including the promoter sequence nucleotides -116 to +60, in UMR106 and RBMC-D8 cells. Nicotine decreased the nuclear protein binding to the cAMP response element (CRE), fibroblast growth factor 2 response element (FRE) and homeodomain protein-binding site (HOX) at 12 and 24 h. This study indicates that nicotine suppresses BSP transcription mediated through CRE, FRE and HOX elements in the proximal promoter of the rat BSP gene.

Iptakalim inhibits PDGF-BB-induced human airway smooth muscle cells proliferation and migration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Wenrui; Kong, Hui; Zeng, Xiaoning

Chronic airway diseases are characterized by airway remodeling which is attributed partly to the proliferation and migration of airway smooth muscle cells (ASMCs). ATP-sensitive potassium (K{sub ATP}) channels have been identified in ASMCs. Mount evidence has suggested that K{sub ATP} channel openers can reduce airway hyperresponsiveness and alleviate airway remodeling. Opening K{sup +} channels triggers K{sup +} efflux, which leading to membrane hyperpolarization, preventing Ca{sup 2+}entry through closing voltage-operated Ca{sup 2+} channels. Intracellular Ca{sup 2+} is the most important regulator of muscle contraction, cell proliferation and migration. K{sup +} efflux decreases Ca{sup 2+} influx, which consequently influences ASMCs proliferation andmore » migration. As a K{sub ATP} channel opener, iptakalim (Ipt) has been reported to restrain the proliferation of pulmonary arterial smooth muscle cells (PASMCs) involved in vascular remodeling, while little is known about its impact on ASMCs. The present study was designed to investigate the effects of Ipt on human ASMCs and the mechanisms underlying. Results obtained from cell counting kit-8 (CCK-8), flow cytometry and 5-ethynyl-2′-deoxyuridine (EdU) incorporation showed that Ipt significantly inhibited platelet-derived growth factor (PDGF)-BB-induced ASMCs proliferation. ASMCs migration induced by PDGF-BB was also suppressed by Ipt in transwell migration and scratch assay. Besides, the phosphorylation of Ca{sup 2+}/calmodulin-dependent kinase II (CaMKII), extracellular regulated protein kinases 1/2 (ERK1/2), protein kinase B (Akt), and cyclic adenosine monophosphate (cAMP) response element binding protein (CREB) were as well alleviated by Ipt administration. Furthermore, we found that the inhibition of Ipt on the PDGF-BB-induced proliferation and migration in human ASMCs was blocked by glibenclamide (Gli), a selective K{sub ATP} channel antagonist. These findings provide a strong evidence to support that Ipt antagonize the proliferating and migrating effects of PDGF-BB on human ASMCs through opening K{sub ATP} channels. Altogether, our results highlighted a novel profile of Ipt as a potent option against the airway remodeling in chronic airway diseases. - Highlights: Iptakalim is a novel ATP-sensitive potassium channel opener. Iptakalim showed anti-proliferation and anti-migration effects on PDGF-BB-induced human airway smooth muscle cells. Inhibitory effects of Iptakalim could be abolished by glibenclamide, a selective K{sub ATP} channel antagonist. Inhibitory effects of Iptakalim involved the signaling pathways of CaMKII, ERK1/2 and Akt, as well as their downstream, CREB.« less

DOE-NE Proliferation and Terrorism Risk Assessment: FY12 Plans Update

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sadasivan, Pratap

2012-06-21

This presentation provides background information on FY12 plans for the DOE Office of Nuclear Energy Proliferation and Terrorism Risk Assessment program. Program plans, organization, and individual project elements are described. Research objectives are: (1) Develop technologies and other solutions that can improve the reliability, sustain the safety, and extend the life of current reactors; (2) Develop improvements in the affordability of new reactors to enable nuclear energy; (3) Develop Sustainable Nuclear Fuel Cycles; and (4) Understand and minimize the risks of nuclear proliferation and terrorism - Goal is to enable the use of risk information to inform NE R&D programmore » planning.« less

Zinc promotes proliferation and activation of myogenic cells via the PI3K/Akt and ERK signaling cascade

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ohashi, Kazuya, E-mail: asuno10k@yahoo.co.jp; Nagata, Yosuke, E-mail: cynagata@mail.ecc.u-tokyo.ac.jp; Wada, Eiji, E-mail: gacchu1@yahoo.co.jp

2015-05-01

Skeletal muscle stem cells named muscle satellite cells are normally quiescent but are activated in response to various stimuli, such as injury and overload. Activated satellite cells enter the cell cycle and proliferate to produce a large number of myogenic progenitor cells, and these cells then differentiate and fuse to form myofibers. Zinc is one of the essential elements in the human body, and has multiple roles, including cell growth and DNA synthesis. However, the role of zinc in myogenic cells is not well understood, and is the focus of this study. We first examined the effects of zinc onmore » differentiation of murine C2C12 myoblasts and found that zinc promoted proliferation, with an increased number of cells incorporating EdU, but inhibited differentiation with reduced myogenin expression and myotube formation. Furthermore, we used the C2C12 reserve cell model of myogenic quiescence to investigate the role of zinc on activation of myogenic cells. The number of reserve cells incorporating BrdU was increased by zinc in a dose dependent manner, with the number dramatically further increased using a combination of zinc and insulin. Akt and extracellular signal-regulated kinase (ERK) are downstream of insulin signaling, and both were phosphorylated after zinc treatment. The zinc/insulin combination-induced activation involved the phosphoinositide 3-kinase (PI3K)/Akt and ERK cascade. We conclude that zinc promotes activation and proliferation of myogenic cells, and this activation requires phosphorylation of PI3K/Akt and ERK as part of the signaling cascade. - Highlights: • Zinc has roles for promoting proliferation and inhibition differentiation of C2C12. • Zinc promotes activation of reserve cells. • Insulin and zinc synergize activation of reserve cells. • PI3K/Akt and ERK cascade affect zinc/insulin-mediated activation of reserve cells.« less

HBV core promoter mutations promote cellular proliferation through E2F1-mediated upregulation of S-phase kinase-associated protein 2 transcription.

PubMed

Huang, Yuehua; Tai, Andrew W; Tong, Shuping; Lok, Anna S F

2013-06-01

Hepatitis B virus (HBV) core promoter (CP) mutations have been associated with an increased risk of hepatocellular carcinoma (HCC) in clinical studies. We previously reported that a combination of CP mutations seen in HCC patients, expressed in HBx gene, increased SKP2 (S-phase kinase-associated protein 2) expression, thereby promoting cellular proliferation. Here, we investigate the possible mechanisms by which CP mutations upregulate SKP2. We used immunoblotting and ATPlite assay to validate the effect of CP mutations in full-length HBV genome on cell cycle regulator levels and cell proliferation. Activation of SKP2 mRNA was assessed by quantitative real-time PCR in primary human hepatocytes (PHH) and HCC cell lines. Effect of CP mutations on SKP2 promoter activity was determined by luciferase assay. Target regulation of E2F1 on SKP2 was analyzed by siRNAs. CP mutations in full-length HBV genome upregulated SKP2 expression, thereby downregulating cell cycle inhibitors and accelerating cellular proliferation. CP mutations enhanced SKP2 promoter activity but had no effect on SKP2 protein stability. Mapping of the SKP2 promoter identified a region necessary for activation by CP mutations that contains an E2F1 response element. Knocking down E2F1 reduced the effects of CP mutations on SKP2 and cellular proliferation. The effect of CP mutations on E2F1 might be mediated through hyperphosphorylation of RB. HBV CP mutations enhance SKP2 transcription by activating the E2F1 transcription factor and in turn downregulate cell cycle inhibitors, thus providing a potential mechanism for an association between CP mutations and HCC. Copyright © 2013 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

Transcriptional regulation of human paraoxonase 1 by PXR and GR in human hepatoma cells.

PubMed

Ponce-Ruiz, N; Rojas-García, A E; Barrón-Vivanco, B S; Elizondo, G; Bernal-Hernández, Y Y; Mejía-García, A; Medina-Díaz, I M

2015-12-25

Human paraoxonase 1 (PON1) is A-esterase synthesized in the liver and secreted into the plasma, where it associates with HDL. PON1 acts as an antioxidant preventing lipid oxidation and detoxifies a wide range of substrates, including organophosphate compounds. The variability of PON1 (enzyme activity/serum levels) has been attributed to internal and external factors. However, the molecular mechanisms involved in the transcriptional regulation of PON1 have not been well-studied. The aim of this study was to evaluate and characterize the transcriptional activation of PON1 by nuclear receptors (NR) in human hepatoma cells. In silico analysis was performed on the promoter region of PON1 to determine the response elements of NR. Real-time PCR was used to evaluate the effect of specific NR ligands on the mRNA levels of genes regulated by NR and PON1. The results indicated that NR response elements had 95% homology to pregnenolone (PXR), glucocorticoids (GR), retinoic acid (RXR) and peroxisomes proliferator-activated receptor alpha (PPARα). Treatments with Dexamethasone (GR ligand), Rifampicin (PXR ligand) and TCDD (AhR ligand) increased the mRNA levels of PON1 at 24 and 48 h. We showed that the activation of GR by Dexamethasone results in PON1 gene induction accompanied by an increase in activity levels. In conclusion, these results demonstrate that GR regulates PON1 gene transcription through directly binding to NR response elements at -95 to -628 bp of the PON1 promoter. This study suggests new molecular mechanisms for the transcriptional regulation of PON1 through a process involving the activation of PXR. Copyright © 2015 Elsevier B.V. All rights reserved.

Effects of combined nicotine and fluoxetine treatment on adult hippocampal neurogenesis and conditioned place preference.

PubMed

Faillace, M P; Zwiller, J; Bernabeu, R O

2015-08-06

Adult neurogenesis occurs in mammals within the dentate gyrus, a hippocampal subarea. It is known to be induced by antidepressant treatment and reduced in response to nicotine administration. We checked here whether the antidepressant fluoxetine would inverse the decrease in hippocampal neurogenesis caused by nicotine. It is shown that repeated, but not a single injection of rats with fluoxetine was able to abolish the decrease in adult dentate cell proliferation produced by nicotine treatment. We measured the expression of several biochemical parameters known to be associated with neurogenesis in the dentate gyrus. Both drugs increased the expression of p75 neurotrophin receptor, which promotes proliferation and early maturation of dentate gyrus cells. Using the conditioned place preference (CPP) paradigm, we also gave both drugs in a context in which their rewarding properties could be measured. Fluoxetine produced a significant but less robust CPP than nicotine. A single injection of fluoxetine was found to reduce nicotine-induced CPP. Moreover, the rewarding properties of nicotine were completely abolished in response to repeated fluoxetine injections. Expression of nicotine-induced CPP was accompanied by an increase of phospho-CREB (cyclic AMP-responsive element-binding protein) and HDAC2 (histone deacetylase 2) expression in the nucleus accumbens. The data suggest that fluoxetine reward, as opposed to nicotine reward, depends on dentate gyrus neurogenesis. Since fluoxetine was able to disrupt the association between nicotine and the environment, this antidepressant may be tested as a treatment for nicotine addiction using cue exposure therapy. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

Reciprocal activation of α5-nAChR and STAT3 in nicotine-induced human lung cancer cell proliferation.

PubMed

Zhang, Yao; Jia, Yanfei; Li, Ping; Li, Huanjie; Xiao, Dongjie; Wang, Yunshan; Ma, Xiaoli

2017-07-20

Cigarette smoking is the top environmental risk factor for lung cancer. Nicotine, the addictive component of cigarettes, induces lung cancer cell proliferation, invasion and migration via the activation of nicotinic acetylcholine receptors (nAChRs). Genome-wide association studies (GWAS) show that CHRNA5 gene encoding α5-nAChR is especially relevant to lung cancer. However, the mechanism of this subunit in lung cancer is not clear. In the present study, we demonstrate that the expression of α5-nAChR is correlated with phosphorylated STAT3 (pSTAT3) expression, smoking history and lower survival of non-small cell lung cancer (NSCLC) samples. Nicotine increased the levels of α5-nAChR mRNA and protein in NSCLC cell lines and activated the JAK2/STAT3 signaling cascade. Nicotine-induced activation of JAK2/STAT3 signaling was inhibited by the silencing of α5-nAChR. Characterization of the CHRNA5 promoter revealed four STAT3-response elements. ChIP assays confirmed that the CHRNA5 promoter contains STAT3 binding sites. By silencing STAT3 expression, nicotine-induced upregulation of α5-nAChR was suppressed. Downregulation of α5-nAChR and/or STAT3 expression inhibited nicotine-induced lung cancer cell proliferation. These results suggest that there is a feedback loop between α5-nAChR and STAT3 that contributes to the nicotine-induced tumor cell proliferation, which indicates that α5-nAChR is an important therapeutic target involved in tobacco-associated lung carcinogenesis. Copyright © 2017 Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, and Genetics Society of China. Published by Elsevier Ltd. All rights reserved.

Nuclear Factor Kappa B Activation and Peroxisome Proliferator-activated Receptor Transactivational Effects of Chemical Components of the Roots of Polygonum multiflorum.

PubMed

Sun, Ya Nan; Li, Wei; Song, Seok Bean; Yan, Xi Tao; Yang, Seo Young; Kim, Young Ho

2016-01-01

Polygonum multiflorum is well-known as "Heshouwu" in traditional Chinese herbal medicine. In Northeast Asia, it is often used as a tonic to prevent premature aging of the kidney and liver, tendons, and bones and strengthening of the lower back and knees. To research the anti-inflammatory activities of components from P. multiflorum. The compounds were isolated by a combination of silica gel and YMC R-18 column chromatography, and their structures were identified by analysis of spectroscopic data (1D, 2D-nuclear magnetic resonance, and mass spectrometry). The anti-inflammatory activities of the isolated compounds 1-15 were evaluated by luciferase reporter gene assays. Fifteen compounds (1-15) were isolated from the roots of P. multiflorum. Compounds 1-5 and 14-15 significantly inhibited tumor necrosis factor-α-induced nuclear factor kappa B-luciferase activity, with IC50 values of 24.16-37.56 μM. Compounds 1-5 also greatly enhanced peroxisome proliferator-activated receptors transcriptional activity with EC50 values of 18.26-31.45 μM. The anthraquinone derivatives were the active components from the roots of P. multiflorum as an inhibitor on inflammation-related factors in human hepatoma cells. Therefore, we suggest that the roots of P. multiflorum can be used to treat natural inflammatory diseases. This study presented that fifteen compounds (1-15) isolated from the roots of Polygonum multiflrum exert signifiant anti inflmmatory effects by inhibiting TNF α induced NF κB activation and PPARs transcription. Abbreviation used: NF κB: Nuclear factor kappa B, PPARs: Peroxisome proliferator activated receptors, PPREs: Peroxisome proliferator response elements, TNF α: Tumor necrosis factor α, ESI-MS: Electrospray ionization mass spectrometry, HepG2: Human hepatoma cells.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Song, Xiulong, E-mail: songxiulong@hotmail.com; Wei, Zhengxi; Shaikh, Zahir A., E-mail: zshaikh@uri.edu

Cadmium (Cd) is a common environmental toxicant and an established carcinogen. Epidemiological studies implicate Cd with human breast cancer. Low micromolar concentrations of Cd promote proliferation of human breast cancer cells in vitro. The growth promotion of breast cancer cells is associated with the activation of MAPK/ERK pathway. This study explores the mechanism of Cd-induced activation of MAPK/ERK pathway. Specifically, the role of cell surface receptors ERα, EGFR, and Src kinase was evaluated in human breast cancer MCF-7 cells treated with 1–3 μM Cd. The activation of ERK was studied using a serum response element (SRE) luciferase reporter assay. Receptormore » phosphorylation was detected by Western blot analyses. Cd treatment increased both the SRE reporter activity and ERK1/2 phosphorylation in a concentration-dependent manner. Cd treatment had no effect on reactive oxygen species (ROS) generation. Also, blocking the entry of Cd into the cells with manganese did not diminish Cd-induced activation of MAPK/ERK. These results suggest that the effect of Cd was likely not caused by intracellular ROS generation, but through interaction with the membrane receptors. While Cd did not appear to activate either EGFR or Src kinase, their inhibition completely blocked the Cd-induced activation of ERK as well as cell proliferation. Similarly, silencing ERα with siRNA or use of ERα antagonist blocked the effects of Cd. Based on these results, it is concluded that not only ERα, but also basal activities of EGFR and Src kinase are essential for Cd-induced signal transduction and activation of MAPK/ERK pathway for breast cancer cell proliferation. - Highlights: • Low micromolar concentrations of Cd rapidly activate ERK1/2 in MCF-7 cells. • Signal transduction and resulting cell proliferation require EGFR, ERα, and Src. • These findings implicate Cd in promotion of breast cancer.« less

A role for palindromic structures in the cis-region of maize Sirevirus LTRs in transposable element evolution and host epigenetic response.

PubMed

Bousios, Alexandros; Diez, Concepcion M; Takuno, Shohei; Bystry, Vojtech; Darzentas, Nikos; Gaut, Brandon S

2016-02-01

Transposable elements (TEs) proliferate within the genome of their host, which responds by silencing them epigenetically. Much is known about the mechanisms of silencing in plants, particularly the role of siRNAs in guiding DNA methylation. In contrast, little is known about siRNA targeting patterns along the length of TEs, yet this information may provide crucial insights into the dynamics between hosts and TEs. By focusing on 6456 carefully annotated, full-length Sirevirus LTR retrotransposons in maize, we show that their silencing associates with underlying characteristics of the TE sequence and also uncover three features of the host-TE interaction. First, siRNA mapping varies among families and among elements, but particularly along the length of elements. Within the cis-regulatory portion of the LTRs, a complex palindrome-rich region acts as a hotspot of both siRNA matching and sequence evolution. These patterns are consistent across leaf, tassel, and immature ear libraries, but particularly emphasized for floral tissues and 21- to 22-nt siRNAs. Second, this region has the ability to form hairpins, making it a potential template for the production of miRNA-like, hairpin-derived small RNAs. Third, Sireviruses are targeted by siRNAs as a decreasing function of their age, but the oldest elements remain highly targeted, partially by siRNAs that cross-map to the youngest elements. We show that the targeting of older Sireviruses reflects their conserved palindromes. Altogether, we hypothesize that the palindromes aid the silencing of active elements and influence transposition potential, siRNA targeting levels, and ultimately the fate of an element within the genome. © 2016 Bousios et al.; Published by Cold Spring Harbor Laboratory Press.

Transposable element distribution, abundance and role in genome size variation in the genus Oryza.

PubMed

Zuccolo, Andrea; Sebastian, Aswathy; Talag, Jayson; Yu, Yeisoo; Kim, HyeRan; Collura, Kristi; Kudrna, Dave; Wing, Rod A

2007-08-29

The genus Oryza is composed of 10 distinct genome types, 6 diploid and 4 polyploid, and includes the world's most important food crop - rice (Oryza sativa [AA]). Genome size variation in the Oryza is more than 3-fold and ranges from 357 Mbp in Oryza glaberrima [AA] to 1283 Mbp in the polyploid Oryza ridleyi [HHJJ]. Because repetitive elements are known to play a significant role in genome size variation, we constructed random sheared small insert genomic libraries from 12 representative Oryza species and conducted a comprehensive study of the repetitive element composition, distribution and phylogeny in this genus. Particular attention was paid to the role played by the most important classes of transposable elements (Long Terminal Repeats Retrotransposons, Long interspersed Nuclear Elements, helitrons, DNA transposable elements) in shaping these genomes and in their contributing to genome size variation. We identified the elements primarily responsible for the most strikingly genome size variation in Oryza. We demonstrated how Long Terminal Repeat retrotransposons belonging to the same families have proliferated to very different extents in various species. We also showed that the pool of Long Terminal Repeat Retrotransposons is substantially conserved and ubiquitous throughout the Oryza and so its origin is ancient and its existence predates the speciation events that originated the genus. Finally we described the peculiar behavior of repeats in the species Oryza coarctata [HHKK] whose placement in the Oryza genus is controversial. Long Terminal Repeat retrotransposons are the major component of the Oryza genomes analyzed and, along with polyploidization, are the most important contributors to the genome size variation across the Oryza genus. Two families of Ty3-gypsy elements (RIRE2 and Atlantys) account for a significant portion of the genome size variations present in the Oryza genus.

Effect of ionizing radiation on human skeletal muscle precursor cells

PubMed Central

Jurdana, Mihaela; Cemazar, Maja; Pegan, Katarina; Mars, Tomaz

2013-01-01

Background Long term effects of different doses of ionizing radiation on human skeletal muscle myoblast proliferation, cytokine signalling and stress response capacity were studied in primary cell cultures. Materials and methods Human skeletal muscle myoblasts obtained from muscle biopsies were cultured and irradiated with a Darpac 2000 X-ray unit at doses of 4, 6 and 8 Gy. Acute effects of radiation were studied by interleukin – 6 (IL-6) release and stress response detected by the heat shock protein (HSP) level, while long term effects were followed by proliferation capacity and cell death. Results Compared with non-irradiated control and cells treated with inhibitor of cell proliferation Ara C, myoblast proliferation decreased 72 h post-irradiation, this effect was more pronounced with increasing doses. Post-irradiation myoblast survival determined by measurement of released LDH enzyme activity revealed increased activity after exposure to irradiation. The acute response of myoblasts to lower doses of irradiation (4 and 6 Gy) was decreased secretion of constitutive IL-6. Higher doses of irradiation triggered a stress response in myoblasts, determined by increased levels of stress markers (HSPs 27 and 70). Conclusions Our results show that myoblasts are sensitive to irradiation in terms of their proliferation capacity and capacity to secret IL-6. Since myoblast proliferation and differentiation are a key stage in muscle regeneration, this effect of irradiation needs to be taken in account, particularly in certain clinical conditions. PMID:24294183

TORC1 is required to balance cell proliferation and cell death in planarians

PubMed Central

Tu, Kimberly C.; Pearson, Bret J.; Alvarado, Alejandro Sánchez

2012-01-01

Multicellular organisms are equipped with cellular mechanisms that enable them to replace differentiated cells lost to normal physiological turnover, injury, and for some such as planarians, even amputation. This process of tissue homeostasis is generally mediated by adult stem cells (ASCs), tissue-specific stem cells responsible for maintaining anatomical form and function. To do so, ASCs must modulate the balance between cell proliferation, i.e. in response to nutrients, and that of cell death, i.e. in response to starvation or injury. But how these two antagonistic processes are coordinated remains unclear. Here, we explore the role of the core components of the TOR pathway during planarian tissue homeostasis and regeneration and identified an essential function for TORC1 in these two processes. RNAi-mediated silencing of TOR in intact animals resulted in a significant increase in cell death, whereas stem cell proliferation and stem cell maintenance were unaffected. Amputated animals failed to increase stem cell proliferation after wounding and displayed defects in tissue remodeling. Together, our findings suggest two distinct roles for TORC1 in planarians. TORC1 is required to modulate the balance between cell proliferation and cell death during normal cell turnover and in response to nutrients. In addition, it is required to initiate appropriate stem cell proliferation during regeneration and for proper tissue remodeling to occur to maintain scale and proportion. PMID:22445864

Epigenetic involvement of Alien/ESET complex in thyroid hormone-mediated repression of E2F1 gene expression and cell proliferation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hong, Wei, E-mail: hongwei@tijmu.edu.cn; College of Basic Medicine, Tianjin Medical University, 300070 Tianjin; Li, Jinru

Highlights: Black-Right-Pointing-Pointer Corepressor Alien interacts with histone methyltransferase ESET in vivo. Black-Right-Pointing-Pointer Alien/ESET complex is recruited to nTRE of T3-responsive gene by liganded TR{beta}1. Black-Right-Pointing-Pointer ESET-mediated H3K9 methylation is required for liganded TR{beta}1-repressed transcription. Black-Right-Pointing-Pointer ESET is involved in T3-repressed G1/S phase transition and proliferation. -- Abstract: The ligand-bound thyroid hormone receptor (TR) is known to repress via a negative TRE (nTRE) the expression of E2F1, a key transcription factor that controls the G1/S phase transition. Alien has been identified as a novel interacting factor of E2F1 and acts as a corepressor of E2F1. The detailed molecular mechanism by whichmore » Alien inhibits E2F1 gene expression remains unclear. Here, we report that the histone H3 lysine 9 (H3K9) methyltransferase (HMT) ESET is an integral component of the corepressor Alien complex and the Alien/ESET complex is recruited to both sites, the E2F1 and the nTRE site of the E2F1 gene while the recruitment to the negative thyroid hormone response element (nTRE) is induced by the ligand-bound TR{beta}1 within the E2F1 gene promoter. We show that, overexpression of ESET promotes, whereas knockdown of ESET releases, the inhibition of TR{beta}1-regulated gene transcription upon T3 stimulation; and H3K9 methylation is required for TR{beta}1-repressed transcription. Furthermore, depletion of ESET impairs thyroid hormone-repressed proliferation as well as the G1/S transition of the cell cycle. Taken together, our data indicate that ESET is involved in TR{beta}1-mediated transcription repression and provide a molecular basis of thyroid hormone-induced repression of proliferation.« less

N-acetylcysteine reverses immunotoxic effects of methyl mercury and augments murine lymphocyte proliferation in vitro

DOE Office of Scientific and Technical Information (OSTI.GOV)

Omara, F.; Fournier, M.; Bernier, J.

1995-12-31

N-Acetylcysteine (NAC) is a thiol antioxidant used clinically to treat chronic inflammatory lung disorders and acetaminophen poisoning in humans. The authors evaluated in vitro the effect of NAC on mitogen-induced blastogenesis in C57BI/6 mouse splenocytes by {sup 3}H-thymidine uptake, and its ability to protect against the immunotoxic effects of methyl mercury on lymphocyte proliferation. Lymphocyte proliferation stimulated by optimal and suboptimal concentrations of concanavalin A (Con A), lipopolysaccharide (LPS), or a combination of calcium ionophore A23187 and phorbol-12-myristate-13-acetate (PMA) were markedly enhanced by NAC. NAC itself was a weak mitogen. The kinetics of the NAC effect on splenocyte proliferation weremore » mitogen dependent. NAC enhanced Con A-induced splenocyte proliferation in a dose-dependent and linear manner but enhanced the LPS-induced response at 50--400 {micro}g/ml of NAC followed by a decline in response to control value at higher concentrations. In splenocytes stimulated with PMA plus A23187, NAC increased proliferation at 50--200 pg/ml followed by a constant response at 200--1,000 {micro}g/ml NAC. When splenocytes were stimulated with higher concentrations of Con A (10 {micro}g/ml) or LPS (150 {micro}g/ml) which markedly suppress splenocyte proliferation, NAC significantly enhanced the Con A-induced response and reversed the inhibitory effect of high concentrations of LPS. NAC also protected lymphocytes against mitogen activation-induced cell death. Methyl mercury at 5 {times} 10{sup {minus}7}--1 {times} 10{sup {minus}6} suppressed Con A- and LPS-induced splenocyte proliferation by over 80%. However, NAC completely reversed the immunotoxic effects of methyl mercury on the mitogen-induced splenocyte proliferation even when the cells were pre-incubated with methyl mercury for 6 or 24 hr before stimulation with the mitogens.« less

mTORC1 and p53

PubMed Central

Hasty, Paul; Sharp, Zelton Dave; Curiel, Tyler J.; Campisi, Judith

2013-01-01

A balance must be struck between cell growth and stress responses to ensure that cells proliferate without accumulating damaged DNA. This balance means that optimal cell proliferation requires the integration of pro-growth and stress-response pathways. mTOR (mechanistic target of rapamycin) is a pleiotropic kinase found in complex 1 (mTORC1). The mTORC1 pathway governs a response to mitogenic signals with high energy levels to promote protein synthesis and cell growth. In contrast, the p53 DNA damage response pathway is the arbiter of cell proliferation, restraining mTORC1 under conditions of genotoxic stress. Recent studies suggest a complicated integration of these pathways to ensure successful cell growth and proliferation without compromising genome maintenance. Deciphering this integration could be key to understanding the potential clinical usefulness of mTORC1 inhibitors like rapamycin. Here we discuss how these p53-mTORC1 interactions might play a role in the suppression of cancer and perhaps the development of cellular senescence and organismal aging. PMID:23255104

Horizontal Gene Acquisitions, Mobile Element Proliferation, and Genome Decay in the Host-Restricted Plant Pathogen Erwinia Tracheiphila

PubMed Central

Shapiro, Lori R.; Scully, Erin D.; Straub, Timothy J.; Park, Jihye; Stephenson, Andrew G.; Beattie, Gwyn A.; Gleason, Mark L.; Kolter, Roberto; Coelho, Miguel C.; De Moraes, Consuelo M.; Mescher, Mark C.; Zhaxybayeva, Olga

2016-01-01

Modern industrial agriculture depends on high-density cultivation of genetically similar crop plants, creating favorable conditions for the emergence of novel pathogens with increased fitness in managed compared with ecologically intact settings. Here, we present the genome sequence of six strains of the cucurbit bacterial wilt pathogen Erwinia tracheiphila (Enterobacteriaceae) isolated from infected squash plants in New York, Pennsylvania, Kentucky, and Michigan. These genomes exhibit a high proportion of recent horizontal gene acquisitions, invasion and remarkable amplification of mobile genetic elements, and pseudogenization of approximately 20% of the coding sequences. These genome attributes indicate that E. tracheiphila recently emerged as a host-restricted pathogen. Furthermore, chromosomal rearrangements associated with phage and transposable element proliferation contribute to substantial differences in gene content and genetic architecture between the six E. tracheiphila strains and other Erwinia species. Together, these data lead us to hypothesize that E. tracheiphila has undergone recent evolution through both genome decay (pseudogenization) and genome expansion (horizontal gene transfer and mobile element amplification). Despite evidence of dramatic genomic changes, the six strains are genetically monomorphic, suggesting a recent population bottleneck and emergence into E. tracheiphila’s current ecological niche. PMID:26992913

O-linked N-acetylglucosamine transferase enhances secretory clusterin expression via liver X receptors and sterol response element binding protein regulation in cervical cancer.

PubMed

Kim, Min Jun; Choi, Mee Young; Lee, Dong Hoon; Roh, Gu Seob; Kim, Hyun Joon; Kang, Sang Soo; Cho, Gyeong Jae; Kim, Yoon Sook; Choi, Wan Sung

2018-01-12

O-linked N-acetylglucosamine transferase (OGT) expression is increased in various cancer types, indicating the potential importance of O-GlcNAcylation in tumorigenesis. Secretory clusterin (sCLU) is involved in cancer cell proliferation and drug resistance, and recently, liver X receptors (LXRs) and sterol response element binding protein-1 (SREBP-1) were reported to regulate sCLU transcription. Here, we found that sCLU is significantly increased in cervical cancer cell lines, which have higher expression levels of O-GlcNAc and OGT than keratinocytes. OGT knockdown decreased expression of LXRs, SREBP-1 and sCLU through hypo-O-GlcNAcylation of LXRs. Additionally, treatment with Thiamet G, O-GlcNAcase OGA inhibitor, increased expression of O-GlcNAcylation and sCLU, and high glucose increased levels of LXRs, SREBP-1 and sCLU in HeLa cells. Moreover, OGT knockdown induced G 0 /G 1 phase cell cycle arrest and late apoptosis in cisplatin-treated HeLa cells, and decreased viability compared to OGT intact HeLa cells. Taken together, these findings suggest that OGT, O-GlcNAcylated LXRs, and SREBP-1 increase sCLU expression in cervical cancer cells, which contributes to drug resistance.

Essential role for cyclic-AMP responsive element binding protein 1 (CREB) in the survival of acute lymphoblastic leukemia.

PubMed

van der Sligte, Naomi E; Kampen, Kim R; ter Elst, Arja; Scherpen, Frank J G; Meeuwsen-de Boer, Tiny G J; Guryev, Victor; van Leeuwen, Frank N; Kornblau, Steven M; de Bont, Eveline S J M

2015-06-20

Acute lymphoblastic leukemia (ALL) relapse remains a leading cause of cancer related death in children, therefore, new therapeutic options are needed. Recently, we showed that a peptide derived from Cyclic-AMP Responsive Element Binding Protein (CREB) was highly phosphorylated in pediatric leukemias. In this study, we determined CREB phosphorylation and mRNA levels showing that CREB expression was significantly higher in ALL compared to normal bone marrow (phosphorylation: P < 0.0001, mRNA: P = 0.004). High CREB and phospho-CREB expression was correlated with a lower median overall survival in a cohort of 140 adult ALL patients. ShRNA mediated knockdown of CREB in ALL cell lines blocked leukemic cell growth by inducing cell cycle arrest and apoptosis. Gene expression array analysis showed downregulation of CREB target genes regulating cell proliferation and glucose metabolism and upregulation of apoptosis inducing genes. Similar to CREB knockdown, the CREB inhibitor KG-501 decreased leukemic cell viability and induced apoptosis in ALL cell lines, as well as primary T-ALL samples, with cases showing high phospho-CREB levels being more sensitive than those with lower phospho-CREB levels. Together, these in vitro findings support an important role for CREB in the survival of ALL cells and identify this transcription factor as a potential target for treatment.

Regulation of oxidative stress responses by ataxia-telangiectasia mutated is required for T cell proliferation.

PubMed

Bagley, Jessamyn; Singh, Gyanesh; Iacomini, John

2007-04-15

Mutations in the gene encoding ataxia-telangiectasia (A-T) mutated (Atm) cause the disease A-T, characterized by immunodeficiency, the molecular basis of which is not known. Following stimulation through the TCR, Atm-deficient T cells and normal T cells in which Atm is inhibited undergo apoptosis rather than proliferation. Apoptosis is prevented by scavenging reactive oxygen species (ROS) during activation. Atm therefore plays a critical role in T cell proliferation by regulating responses to ROS generated following T cell activation. The inability of Atm-deficient T cells to control responses to ROS is therefore the molecular basis of immunodeficiency associated with A-T.

Zinc Promotes Adipose-Derived Mesenchymal Stem Cell Proliferation and Differentiation towards a Neuronal Fate.

PubMed

Moon, Mi-Young; Kim, Hyun Jung; Choi, Bo Young; Sohn, Min; Chung, Tae Nyoung; Suh, Sang Won

2018-01-01

Zinc is an essential element required for cell division, migration, and proliferation. Under zinc-deficient conditions, proliferation and differentiation of neural progenitors are significantly impaired. Adipose-derived mesenchymal stem cells (AD-MSCs) are multipotent stem cells that can differentiate into neurons. The aim of this study was to evaluate the effect of zinc on AD-MSC proliferation and differentiation. We initially examined the effect of zinc on stem cell proliferation at the undifferentiated stage. AD-MSCs showed high proliferation rates on day 6 in 30  μ M and 100  μ M of ZnCl 2 . Zinc chelation inhibited AD-MSC proliferation via downregulation of ERK1/2 activity. We then assessed whether zinc was involved in cell migration and neurite outgrowth during differentiation. After three days of neuronal differentiation, TUJ-1-positive cells were observed, implying that AD-MSCs had differentiated into early neuron or neuron-like cells. Neurite outgrowth was increased in the zinc-treated group, while the CaEDTA-treated group showed diminished, shrunken neurites. Furthermore, we showed that zinc promoted neurite outgrowth via the inactivation of RhoA and led to the induction of neuronal gene expression (MAP2 and nestin) in differentiated stem cells. Taken together, zinc promoted AD-MSC proliferation and affected neuronal differentiation, mainly by increasing neurite outgrowth.

Regulation of Ketone Body Metabolism and the Role of PPARα

PubMed Central

Grabacka, Maja; Pierzchalska, Malgorzata; Dean, Matthew; Reiss, Krzysztof

2016-01-01

Ketogenesis and ketolysis are central metabolic processes activated during the response to fasting. Ketogenesis is regulated in multiple stages, and a nuclear receptor peroxisome proliferator activated receptor α (PPARα) is one of the key transcription factors taking part in this regulation. PPARα is an important element in the metabolic network, where it participates in signaling driven by the main nutrient sensors, such as AMP-activated protein kinase (AMPK), PPARγ coactivator 1α (PGC-1α), and mammalian (mechanistic) target of rapamycin (mTOR) and induces hormonal mediators, such as fibroblast growth factor 21 (FGF21). This work describes the regulation of ketogenesis and ketolysis in normal and malignant cells and briefly summarizes the positive effects of ketone bodies in various neuropathologic conditions. PMID:27983603

Selective Activation of a Perforin-Granzyme B Fusion Protein Toxin by PSA as Therapy for Metastatic Prostate Cancer

DTIC Science & Technology

2016-10-01

Prostate Cancer PRINCIPAL INVESTIGATOR: Samuel Denmeade RECIPIENT: Johns Hopkins University Baltimore, MD 21218 REPORT DATE: October 2016 TYPE...PSA as Therapy for Metastatic Prostate Cancer 5b. GRANT NUMBER W81XWH-15-1-0382 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Samuel R Denmeade...cytotoxic agent that can selectively kill both proliferating and non-proliferating prostate cancer cells within a metastatic site without significant host

Inhibition of proliferation and induction of apoptosis in soft tissue sarcoma cells by interferon-α and retinoids

PubMed Central

Brodowicz, T; Wiltschke, C; Kandioler-Eckersberger, D; Grunt, T W; Rudas, M; Schneider, S M; Hejna, M; Budinsky, A; Zielinski, C C

1999-01-01

Uncontrolled proliferation and a defect of apoptosis constitute crucial elements in the development and progression of tumours. Among many other biological response modifiers known to influence these mechanisms, the efficacy of retinoids and interferons in the treatment of various malignant entities is currently matter of discussion. In the present study, we have investigated the effects of 9-cis-retinoic acid (9cRA), 13-cis-retinoic acid (13cRA), all-trans-retinoic acid (tRA) and interferon-α on proliferation and apoptosis of human soft tissue sarcoma (STS) cell lines HTB-82 (rhabdomyosarcoma), HTB-91 (fibrosarcoma), HTB-92 (liposarcoma), HTB-93 (synovial sarcoma) and HTB-94 (chondrosarcoma) in relation to p53 genotype as well as p53 expression. HTB-91, HTB-92 and HTB-94 STS cells exhibited mutant p53, whereas wild-type p53 was found in HTB-93 STS cells, and a normal p53 status in HTB-82 STS cells, carrying a silent point mutation only. Interferon-α, irrespective of p53 status, inhibited the proliferation of all five cell lines dose- and time-dependently. Similarly, 9cRA, 13cRA and tRA decreased the proliferation of HTB-82 and HTB-93 STS cells, whereas the proliferation of p53-mutated HTB-91, HTB-92 and HTB-94 STS cells remained unchanged. Furthermore, only 9cRA and tRA were capable of inducing apoptosis in HTB-82 and HTB-93 STS cells, whereas HTB-91, HTB-92 and HTB-94 STS cells did not undergo apoptosis under the influence of 9cRA or tRA. Retinoic acid receptor (RAR)-α and RAR-β mRNA were not detectable by Northern blot analysis in the five STS cell lines, whereas mRNA for the universal retinoic acid receptor, RAR-γ, was expressed in all STS cell lines indicating that retinoid resistance was not associated with a lack of RAR expression. Apoptosis was not induced by interferon-α or 13cRA in any of the five STS cell lines tested. Our results indicate that within the panel of tested STS cell lines, inhibition of proliferation and induction of apoptosis result from different mechanisms which differ in their dependence upon the presence of intact p53. © 1999 Cancer Research Campaign PMID:10424735

The thorny path linking cellular senescence to organismalaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patil, Christopher K.; Mian, Saira; Campisi, Judith

2005-08-09

Half a century is fast approaching since Hayflick and colleagues formally described the limited ability of normal human cells to proliferate in culture (Hayflick and Moorhead, 1961). This finding--that normal somatic cells, in contrast to cancer cells, cannot divide indefinitely--challenged the prevailing idea that cells from mortal multicellular organisms were intrinsically ''immortal'' (Carrell, 1912). It also spawned two hypotheses, essential elements of which persist today. The first held that the restricted proliferation of normal cells, now termed cellular senescence, suppresses cancer (Hayflick, 1965; Sager, 1991; Campisi, 2001). The second hypothesis, as explained in the article by Lorenzini et al., suggestedmore » that the limited proliferation of cells in culture recapitulated aspects of organismal aging (Hayflick, 1965; Martin, 1993). How well have these hypotheses weathered the ensuing decades? Before answering this question, we first consider current insights into the causes and consequences of cellular senescence. Like Lorenzini et al., we limit our discussion to mammals. We also focus on fibroblasts, the cell type studied by Lorenzini et al., but consider other types as well. We suggest that replicative capacity in culture is not a straightforward assessment, and that it correlates poorly with both longevity and body mass. We speculate this is due to the malleable and variable nature of replicative capacity, which renders it an indirect metric of qualitative and quantitative differences among cells to undergo senescence, a response that directly alters cellular phenotype and might indirectly alter tissue structure and function.« less

From the Cover: Fenretinide, Troglitazone, and Elmiron Add to Weight of Evidence Support for Hemangiosarcoma Mode-of-Action From Studies in Mice.

PubMed

Cook, Jon C; Obert, Leslie A; Koza-Taylor, Petra; Coskran, Timothy M; Opsahl, Alan C; Ziemek, Daniel; Roy, Marc; Qian, Jessie; Lawton, Michael P; Criswell, Kay A

2018-01-01

Pharmaceuticals and chemicals produce hemangiosarcomas (HS) in mice, often by nongenotoxic, proliferative mechanisms. A mode-of-action (MOA) for hemangiosarcoma was proposed based on information presented at an international workshop (Cohen et al., Hemangiosarcoma in rodents: Mode-of-action evaluation and human relevance. Toxicol. Sci. 111, 4-18.). Five key elements of the MOA were articulated and included hypoxia, macrophage activation, increased angiogenic growth factors, dysregulated angiogenesis/erythropoiesis, and endothial cell proliferation. The goal of the current study was to add to the weight-of-evidence for the proposed MOA by assessing these key elements with 3 different compounds of varying potency for HS induction: fenretinide (high), troglitazone (intermediate), and elmiron (low). Multiple endpoints, including hypoxia (hyproxyprobe, transcriptomics), endothelial cell (EC) proliferation, and clinical and anatomic pathology, were assessed after 2, 4, and 13-weeks of treatment in B6C3F1 mice. All 3 compounds demonstrated strong evidence for dysregulated erythropoiesis (decrease in RBC and a failure to increase reticulocytes) and macrophage activation (4- to 11-fold increases); this pattern of hematological changes in mice might serve as an early biomarker to evaluate EC proliferation in suspected target organs for potential HS formation. Fenretinide demonstrated all 5 key elements, while troglitazone demonstrated 4 and elmiron demonstrated 3. Transcriptomics provided support for the 5 elements of the MOA, but was not any more sensitive than hypoxyprobe immunohistochemistry for detecting hypoxia. The overall transcriptional evidence for the key elements of the proposed MOA was also consistent with the potency of HS induction. These data, coupled with the previous work with 2-butoxyethanol and pregablin, increase the weight-of-evidence for the proposed MOA for HS formation. © The Author 2017. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

SIRT1 inhibits the mouse intestinal motility and epithelial proliferation

USDA-ARS?s Scientific Manuscript database

SIRT1 inhibits the mouse intestinal motility and epithelial proliferation. Sirtuin 1 (SIRT1), a NAD+-dependent histone deacetylase, is involved in a wide array of cellular processes, including glucose homeostasis, energy metabolism, proliferation and apoptosis, and immune response. However, it is un...

A comparative study of the proliferation and osteogenic differentiation of human periodontal ligament cells cultured on β-TCP ceramics and demineralized bone matrix with or without osteogenic inducers in vitro.

PubMed

An, Shaofeng; Gao, Yan; Huang, Xiangya; Ling, Junqi; Liu, Zhaohui; Xiao, Yin

2015-05-01

The repair of bone defects that result from periodontal diseases remains a clinical challenge for periodontal therapy. β-tricalcium phosphate (β-TCP) ceramics are biodegradable inorganic bone substitutes with inorganic components that are similar to those of bone. Demineralized bone matrix (DBM) is an acid-extracted organic matrix derived from bone sources that consists of the collagen and matrix proteins of bone. A few studies have documented the effects of DBM on the proliferation and osteogenic differentiation of human periodontal ligament cells (hPDLCs). The aim of the present study was to investigate the effects of inorganic and organic elements of bone on the proliferation and osteogenic differentiation of hPDLCs using three-dimensional porous β-TCP ceramics and DBM with or without osteogenic inducers. Primary hPDLCs were isolated from human periodontal ligaments. The proliferation of the hPDLCs on the scaffolds in the growth culture medium was examined using a Cell-Counting kit-8 (CCK-8) and scanning electron microscopy (SEM). Alkaline phosphatase (ALP) activity and the osteogenic differentiation of the hPDLCs cultured on the β-TCP ceramics and DBM were examined in both the growth culture medium and osteogenic culture medium. Specific osteogenic differentiation markers were examined using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). SEM images revealed that the cells on the β-TCP were spindle-shaped and much more spread out compared with the cells on the DBM surfaces. There were no significant differences observed in cell proliferation between the β-TCP ceramics and the DBM scaffolds. Compared with the cells that were cultured on β-TCP ceramics, the ALP activity, as well as the Runx2 and osteocalcin (OCN) mRNA levels in the hPDLCs cultured on DBM were significantly enhanced both in the growth culture medium and the osteogenic culture medium. The organic elements of bone may exhibit greater osteogenic differentiation effects on hPDLCs than the inorganic elements.

Pathogen Proliferation Governs the Magnitude but Compromises the Function of CD8 T Cells1

PubMed Central

Sad, Subash; Dudani, Renu; Gurnani, Komal; Russell, Marsha; van Faassen, Henk; Finlay, Brett; Krishnan, Lakshmi

2014-01-01

CD8+ T cell memory is critical for protection against many intracellular pathogens. However, it is not clear how pathogen virulence influences the development and function of CD8+ T cells. Salmonella typhimurium (ST) is an intracellular bacterium that causes rapid fatality in susceptible mice and chronic infection in resistant strains. We have constructed recombinant mutants of ST, expressing the same immunodominant Ag OVA, but defective in various key virulence genes. We show that the magnitude of CD8+ T cell response correlates directly to the intracellular proliferation of ST. Wild-type ST displayed efficient intracellular proliferation and induced increased numbers of OVA-specific CD8+ T cells upon infection in mice. In contrast, mutants with defective Salmonella pathogenicity island II genes displayed poor intracellular proliferation and induced reduced numbers of OVA-specific CD8+ T cells. However, when functionality of the CD8+ T cell response was measured, mutants of ST induced a more functional response compared with the wild-type ST. Infection with wild-type ST, in contrast to mutants defective in pathogenicity island II genes, induced the generation of mainly effector-memory CD8+ T cells that expressed little IL-2, failed to mediate efficient cytotoxicity, and proliferated poorly in response to Ag challenge in vivo. Taken together, these results indicate that pathogens that proliferate rapidly and chronically in vivo may evoke functionally inferior memory CD8+ T cells which may promote the survival of the pathogen. PMID:18424704

PTTG1, A novel androgen responsive gene is required for androgen-induced prostate cancer cell growth and invasion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Zheng; Jin, Bo; Jin, Yaqiong

Androgens (AR) play an important role in initiation and progression of prostate cancer. It has been shown that AR exert their effects mainly through the androgen-activated AR which binds to androgen response elements (AREs) in the regulatory regions of target genes to regulate the transcription of androgen-responsive genes, thus, identification of AR downstream target gene is critical to understand androgen function in prostate cancer. In this study, our results showed that androgen treatment of LNCaP cells induced PTTG1 expression, which was blocked by the androgen receptor antagonist, Casodex. Bioinformatics analysis and experiments using PTTG1 promoter deletion mutants showed that themore » PTTG1 promoter contains a putative androgen response element (ARE), which localizes in the −851 to −836 region of the promoter. Androgen activated androgen receptor (AR) binding to this ARE was confirmed by Chromatin immunoprecipitation (ChIP) assay. Furthermore, Knockdown of PTTG1 expression using short hairpin RNA significantly reduced androgen-induced LNCaP cell growth and invasion. In addition, we showed PTTG1 is highly expressed in metastasis prostate cancer tissue. These results suggest that PTTG1 is a novel downstream target gene of androgen receptor and take part in prostate cancer proliferation and metastasis. - Highlights: • Androgen treatment of LNCaP cells induced PTTG1 expression. • Knockdown of PTTG1 expression significantly reduced androgen-induced LNCaP cell growth and invasion. • PTTG1 is highly expressed in metastasis prostate cancer tissue. • PTTG1 is a novel downstream target gene of androgen receptor.« less

p53 inactivation decreases dependence on estrogen/ERK signalling for proliferation but promotes EMT and susceptility to 3-bromopyruvate in ERα+ breast cancer MCF-7 cells.

PubMed

Rieber, Manuel; Strasberg-Rieber, Mary

2014-03-15

Most breast cancers express the estrogen receptor alpha (ERα(+)), harbor wt TP53, depend on estrogen/ERK signalling for proliferation, and respond to anti-estrogens. However, concomittant activation of the epidermal growth factor receptor (EGFR)/MEK pathway promotes resistance by decreasing estrogen dependence. Previously, we showed that retroviral transduction of mutant p53 R175H into wt TP53 ERα(+) MCF-7 cells induces epidermal growth factor (EGF)-independent proliferation, activation of the EGF receptor (p-EGFR) and some characteristics of epithelial-mesenchymal transition (EMT). To investigate whether p53 inactivation augments ERα(+) cell proliferation in response to restrictive estradiol, chemical MEK inhibition or metabolic inhibitors. Introduction of mutant p53 R175H lowered expression of p53-dependent PUMA and p21WAF1, decreased E-cadherin and cytokeratin 18 associated with EMT, but increased the % of proliferating ERα(+)/Ki67 cells, diminishing estrogen dependence. These cells also exhibited higher proliferation in the presence of MEK-inhibitor UO126, reciprocally correlating with preferential susceptibility to the pyruvate analog 3-bromopyruvate (3-BrPA) without a comparable response to 2-deoxyglucose. p53 siRNA silencing by electroporation in wt TP53 MCF-7 cells also decreased estrogen dependence and response to MEK inhibition, while also conferring susceptibility to 3-BrPA. (a) ERα(+) breast cancer cells dysfunctional for TP53 which proliferate irrespective of low estrogen and chemical MEK inhibition are likely to increase metabolic consumption becoming increasingly susceptible to 3-BrPA; (b) targeting the pyruvate pathway may improve response to endocrine therapy in ERα(+) breast cancer with p53 dysfunction. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Lymphocyte responses to stress in postpartum women: relationship to vagal tone.

PubMed

Redwine, L S; Altemus, M; Leong, Y M; Carter, C S

2001-04-01

Although women spend their lives in various phases of the reproductive cycle, including menstrual, pregnancy, postpartum, lactation and menopause, few studies have examined immune responses to stress in women as a function of events associated with reproduction. The objective of this study was to evaluate differential effects of breastfeeding (n = 16), bottlefeeding (n = 10) and non-postpartum (n = 10) status on lymphocyte responses to stressful tasks (public speaking and mental arithmetic). To measure cellular immune responses, lymphocyte proliferation to plant lectins, poke weed mitogen (PWM) and phytohemagglutinin (PHA) were used. The autonomic measures, heart rate, vagal tone, blood pressure and the hormones of the HPA axis, ACTH and cortisol, were measured and their possible roles in mediating lymphocyte proliferation responses were examined. Recently parturient women who were breastfeeding or bottlefeeding had attenuated stress-induced change in lymphocyte responses to PWM compared with non-postpartum women, tested in the follicular phase of their cycle (P < 0.05). Also, lymphocyte responses to PHA were higher in the breastfeeding group compared with non-postpartum controls (P < 0.05). Regression analyses revealed that an index of cardiac vagal tone, but not other autonomic or endocrine measures, was positively predictive of lymphocyte proliferation to PWM. To summarize, these findings suggest that lactation and parturition can influence lymphocyte proliferation and that activity in the vagal system may influence lymphocyte responses to stress.

Transcriptional activation of melanocortin 2 receptor accessory protein by PPARγ in adipocytes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Nam Soo; Kim, Yoon-Jin; Cho, Si Young

2013-09-27

Highlights: •MRAP enhanced HSL expression. •ACTH-mediated MRAP reduced glycerol release. •PPARγ induced MRAP expression. •PPARγ bound to the MRAP promoter. -- Abstract: Adrenocorticotropic hormone (ACTH) in rodents decreases lipid accumulation and body weight. Melanocortin receptor 2 (MC2R) and MC2R accessory protein (MRAP) are specific receptors for ACTH in adipocytes. Peroxisome proliferator-activated receptor γ (PPARγ) plays a role in the transcriptional regulation of metabolic pathways such as adipogenesis and β-oxidation of fatty acids. In this study we investigated the transcriptional regulation of MRAP expression during differentiation of 3T3-L1 cells. Stimulation with ACTH affected lipolysis in murine mature adipocytes via MRAP. Putativemore » peroxisome proliferator response element (PPRE) was identified in the MRAP promoter region. In chromatin immunoprecipitation and reporter assays, we observed binding of PPARγ to the MRAP promoter. The mutagenesis experiments showed that the −1209/−1198 region of the MRAP promoter could function as a PPRE site. These results suggest that PPARγ is required for transcriptional activation of the MRAP gene during adipogenesis, which contributes to understanding of the molecular mechanism of lipolysis in adipocytes.« less

G protein-coupled receptor 30 down-regulates cofactor expression and interferes with the transcriptional activity of glucocorticoid.

PubMed

Ylikomi, Timo; Vienonen, Annika; Ahola, Tytti M

2004-11-01

G protein-coupled receptor 30 (GPR30) has previously been described to be important in steroid-mediated growth and to inhibit cell proliferation. Here we investigated whether the effect of GPR30 on cell growth is dependent on steroid hormone receptors. We stably introduced GPR30 in immortalized normal mammary epithelial (HME) cells using retroviruses for gene delivery. GPR30 inhibited the growth and proliferation of the cells. They expressed glucocorticoid receptor, but not estrogen or progesterone receptor. GPR30 down-regulated the expression of cofactor transcription intermediary factor 2 (TIF2) analyzed using quantitative RT-PCR analysis, and also diminished the expression of TIF2 at protein level analyzed by Western blotting using nuclear extracts from mammary epithelial cells. When HME cells were transiently transfected with the glucocorticoid response element MMTV-luc reporter plasmid, stable expression of GPR30 resulted in the abolition of ligand-induced transactivation of the promoter. In COS cells, transient transfection of GPR30 with glucocorticoid receptor alpha resulted in an abrogation of the MMTV-luc and GRE-luc reporter activities induced by dexamethasone. The results suggest a novel mechanism by which membrane-initiated signaling interferes with steroid signaling.

Estrogenic Activities of Fatty Acids and a Sterol Isolated from Royal Jelly

PubMed Central

Isohama, Yoichiro; Maruyama, Hiroe; Yamada, Yayoi; Narita, Yukio; Ohta, Shozo; Araki, Yoko; Miyata, Takeshi; Mishima, Satoshi

2008-01-01

We have previously reported that royal jelly (RJ) from honeybees (Apis mellifera) has weak estrogenic activity mediated by interaction with estrogen receptors that leads to changes in gene expression and cell proliferation. In this study, we isolated four compounds from RJ that exhibit estrogenic activity as evaluated by a ligand-binding assay for the estrogen receptor (ER) β. These compounds were identified as 10-hydroxy-trans-2-decenoic acid, 10-hydroxydecanoic acid, trans-2-decenoic acid and 24-methylenecholesterol. All these compounds inhibited binding of 17β-estradiol to ERβ, although more weakly than diethylstilbestrol or phytoestrogens. However, these compounds had little or no effect on the binding of 17β-estradiol to ERα. Expression assays suggested that these compounds activated ER, as evidenced by enhanced transcription of a reporter gene containing an estrogen-responsive element. Treatment of MCF-7 cells with these compounds enhanced their proliferation, but concomitant treatment with tamoxifen blocked this effect. Exposure of immature rats to these compounds by subcutaneous injection induced mild hypertrophy of the luminal epithelium of the uterus, but was not associated with an increase in uterine weight. These findings provide evidence that these compounds contribute to the estrogenic effect of RJ. PMID:18830443

Regulation of Proteome Maintenance Gene Expression by Activators of Peroxisome Proliferator-Activated Receptor a (PPARa)

EPA Science Inventory

The nuclear receptor peroxisome proliferator-activated receptor alpha (PPARa) is activated by a large number of xenobiotic and hypolipidemic compounds called peroxisome proliferator chemicals (PPC). One agonist of PPARa (WY-14,643) regulates responses in the mouse liver to chemic...

Characterisation of the immune response to type I collagen in scleroderma

PubMed Central

Warrington, Kenneth J; Nair, Usha; Carbone, Laura D; Kang, Andrew H; Postlethwaite, Arnold E

2006-01-01

This study was conducted to examine the frequency, phenotype, and functional profile of T lymphocytes that proliferate in response to type I collagen (CI) in patients with scleroderma (SSc). Peripheral blood mononuclear cells (PBMCs) from SSc patients, healthy controls, and rheumatoid arthritis disease controls were labeled with carboxy-fluorescein diacetate, succinimidyl ester (CFSE), cultured with or without antigen (bovine CI) for 14 days, and analysed by flow cytometry. Surface markers of proliferating cells were identified by multi-color flow cytometry. T-cell lines were derived after sorting for proliferating T cells (CFSElow). Cytokine expression in CI-responsive T cells was detected by intracellular staining/flow cytometry and by multiplex cytokine bead assay (Bio-Plex). A T-cell proliferative response to CI was detected in 8 of 25 (32%) SSc patients, but was infrequent in healthy or disease controls (3.6%; p = 0.009). The proliferating T cells expressed a CD4+, activated (CD25+), memory (CD45RO+) phenotype. Proliferation to CI did not correlate with disease duration or extent of skin involvement. T-cell lines were generated using in vitro CI stimulation to study the functional profile of these cells. Following activation of CI-reactive T cells, we detected intracellular interferon (IFN)-γ but not interleukin (IL)-4 by flow cytometry. Supernatants from the T-cell lines generated in vitro contained IL-2, IFN-γ, GM-CSF (granulocyte macrophage-colony-stimulating factor), and tumour necrosis factor-α, but little or no IL-4 and IL-10, suggesting that CI-responsive T cells express a predominantly Th1 cytokine pattern. In conclusion, circulating memory CD4 T cells that proliferate to CI are present in a subset of patients with SSc, but are infrequent in healthy or disease controls. PMID:16879746

Glucagon-like petide-2 acts on colon cancer myofibroblasts to stimulate proliferation, migration and invasion of both myofibroblasts and cancer cells via the IGF pathway.

PubMed

Shawe-Taylor, Marianne; Kumar, J Dinesh; Holden, Whitney; Dodd, Steven; Varga, Akos; Giger, Olivier; Varro, Andrea; Dockray, Graham J

2017-05-01

Glucagon-like peptide (GLP)-2 stimulates intestinal epithelial proliferation by acting, in part, via IGF release from sub-epithelial myofibroblasts. The response of myofibroblasts to GLP-2 remains incompletely understood. We studied the action of GLP-2 on myofibroblasts from colon cancer and adjacent tissue, and the effects of conditioned medium from these cells on epithelial cell proliferation, migration and invasion. GLP-2 stimulated proliferation, migration and invasion of myofibroblasts and the proliferative and invasive responses of cancer-associated myofibroblasts were greater than those of myofibroblasts from adjacent tissue. The responses were inhibited by an IGF receptor inhibitor, AG1024. Conditioned medium from GLP-2 treated myofibroblasts increased proliferation, migration and invasion of SW480, HT29, LoVo epithelial cells and these responses were inhibited by AG1024; GLP-2 alone had no effect on these cells. In addition, when myofibroblasts and epithelial cells were co-cultured in Ibidi chambers there was mutual stimulation of migration in response to GLP-2. The latter increased both IGF-1 and IGF-2 transcript abundance in myofibroblasts. Moreover, a number of IGF binding proteins (IGFBP-4, -5, -7) were identified in myofibroblast medium; in the presence of GLP-2 there was increased abundance of the cleavage products of IGBBP-4 and IGFBP-5 suggesting activation of a degradation mechanism that might increase IGF bioavailability. The data suggest that GLP-2 stimulates cancer myofibroblast proliferation, migration and invasion; GLP-2 acts indirectly on epithelial cells partly via increased IGF expression in myofibroblasts and partly, perhaps, by increased bioavailability through degradation of IGFBPs. Copyright © 2017 Elsevier Inc. All rights reserved.

The DEK oncogene activates VEGF expression and promotes tumor angiogenesis and growth in HIF-1α-dependent and -independent manners

PubMed Central

Li, Yang; Lv, Zhaohui; Zhu, Jie; Lin, Jing; Ding, Lihua; Ye, Qinong

2016-01-01

The DEK oncogene is overexpressed in various cancers and overexpression of DEK correlates with poor clinical outcome. Vascular endothelial growth factor (VEGF) is the most important regulator of tumor angiogenesis, a process essential for tumor growth and metastasis. However, whether DEK enhances tumor angiogenesis remains unclear. Here, we show that DEK is a key regulator of VEGF expression and tumor angiogenesis. Using chromatin immunoprecipitation assay, we found that DEK promoted VEGF transcription in breast cancer cells (MCF7, ZR75-1 and MDA-MB-231) by directly binding to putative DEK-responsive element (DRE) of the VEGF promoter and indirectly binding to hypoxia response element (HRE) upstream of the DRE through its interaction with the transcription factor hypoxia-inducible factor 1α (HIF-1α), a master regulator of tumor angiogenesis and growth. DEK is responsible for recruitment of HIF-1α and the histone acetyltransferase p300 to the VEGF promoter. DEK-enhanced VEGF increases vascular endothelial cell proliferation, migration and tube formation as well as angiogenesis in the chick chorioallantoic membrane. DEK promotes tumor angiogenesis and growth in nude mice in HIF-1α-dependent and -independent manners. Immunohistochemical staining showed that DEK expression positively correlates with the expression of VEGF and microvessel number in 58 breast cancer patients. Our data establish DEK as a sequence-specific binding transcription factor, a novel coactivator for HIF-1α in regulation of VEGF transcription and a novel promoter of angiogenesis. PMID:26988756

Evidence for a role of Collapsin response mediator protein-2 in signaling pathways that regulate the proliferation of non-neuronal cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tahimic, Candice Ginn T.; Tomimatsu, Nozomi; Nishigaki, Ryuichi

Collapsin response mediator protein-2 or Crmp-2 plays a critical role in the establishment of neuronal polarity. In this study, we present evidence that apart from its functions in neurodevelopment, Crmp-2 is also involved in pathways that regulate the proliferation of non-neuronal cells through its phosphorylation by regulatory proteins. We show that Crmp-2 undergoes dynamic phosphorylation changes in response to contact inhibition-induced quiescence and that hyperphosphorylation of Crmp-2 occurs in a tumor. We further suggest that de-regulation of Crmp-2 phosphorylation levels at certain amino acid residues may lead to aberrant cell proliferation and consequently, tumorigenesis.

Proliferation risks from nuclear power infrastructure

NASA Astrophysics Data System (ADS)

Squassoni, Sharon

2017-11-01

Certain elements of nuclear energy infrastructure are inherently dual-use, which makes the promotion of nuclear energy fraught with uncertainty. Are current restraints on the materials, equipment, and technology that can be used either to produce fuel for nuclear electricity generation or material for nuclear explosive devices adequate? Technology controls, supply side restrictions, and fuel market assurances have been used to dissuade countries from developing sensitive technologies but the lack of legal restrictions is a continued barrier to permanent reduction of nuclear proliferation risks.

Dissecting the T Cell Response: Proliferation Assays vs. Cytokine Signatures by ELISPOT

PubMed Central

Anthony, Donald D.; Milkovich, Kimberly A.; Zhang, Wenji; Rodriguez, Benigno; Yonkers, Nicole L.; Tary-Lehmann, Magdalena; Lehmann, Paul V.

2012-01-01

Chronic allograft rejection is in part mediated by host T cells that recognize allogeneic antigens on transplanted tissue. One factor that determines the outcome of a T cell response is clonal size, while another is the effector quality. Studies of alloimmune predictors of transplant graft survival have most commonly focused on only one measure of the alloimmune response. Because differing qualities and frequencies of the allospecific T cell response may provide distinctly different information we analyzed the relationship between frequency of soluble antigen and allo-antigen specific memory IFN-γ secreting CD4 and CD8 T cells, their ability to secrete IL-2, and their proliferative capacity, while accounting for cognate and bystander proliferation. The results show proliferative responses primarily reflect on IL-2 production by antigen-specific T cells, and that proliferating cells in such assays entail a considerable fraction of bystander cells. On the other hand, proliferation (and IL-2 production) did not reflect on the frequency of IFN-γ producing memory cells, a finding particularly accentuated in the CD8 T cell compartment. These data provide rationale for considering both frequency and effector function of pre-transplant T cell reactivity when analyzing immune predictors of graft rejection. PMID:24710419

Neurotoxic Doses of Chronic Methamphetamine Trigger Retrotransposition of the Identifier Element in Rat Dorsal Dentate Gyrus

PubMed Central

Moszczynska, Anna; Burghardt, Kyle J.; Yu, Dongyue

2017-01-01

Short interspersed elements (SINEs) are typically silenced by DNA hypermethylation in somatic cells, but can retrotranspose in proliferating cells during adult neurogenesis. Hypomethylation caused by disease pathology or genotoxic stress leads to genomic instability of SINEs. The goal of the present investigation was to determine whether neurotoxic doses of binge or chronic methamphetamine (METH) trigger retrotransposition of the identifier (ID) element, a member of the rat SINE family, in the dentate gyrus genomic DNA. Adult male Sprague-Dawley rats were treated with saline or high doses of binge or chronic METH and sacrificed at three different time points thereafter. DNA methylation analysis, immunohistochemistry and next-generation sequencing (NGS) were performed on the dorsal dentate gyrus samples. Binge METH triggered hypomethylation, while chronic METH triggered hypermethylation of the CpG-2 site. Both METH regimens were associated with increased intensities in poly(A)-binding protein 1 (PABP1, a SINE regulatory protein)-like immunohistochemical staining in the dentate gyrus. The amplification of several ID element sequences was significantly higher in the chronic METH group than in the control group a week after METH, and they mapped to genes coding for proteins regulating cell growth and proliferation, transcription, protein function as well as for a variety of transporters. The results suggest that chronic METH induces ID element retrotransposition in the dorsal dentate gyrus and may affect hippocampal neurogenesis. PMID:28272323

Hepatic CREB3L3 controls whole-body energy homeostasis and improves obesity and diabetes.

PubMed

Nakagawa, Yoshimi; Satoh, Aoi; Yabe, Sachiko; Furusawa, Mika; Tokushige, Naoko; Tezuka, Hitomi; Mikami, Motoki; Iwata, Wakiko; Shingyouchi, Akiko; Matsuzaka, Takashi; Kiwata, Shiori; Fujimoto, Yuri; Shimizu, Hidehisa; Danno, Hirosuke; Yamamoto, Takashi; Ishii, Kiyoaki; Karasawa, Tadayoshi; Takeuchi, Yoshinori; Iwasaki, Hitoshi; Shimada, Masako; Kawakami, Yasushi; Urayama, Osamu; Sone, Hirohito; Takekoshi, Kazuhiro; Kobayashi, Kazuto; Yatoh, Shigeru; Takahashi, Akimitsu; Yahagi, Naoya; Suzuki, Hiroaki; Yamada, Nobuhiro; Shimano, Hitoshi

2014-12-01

Transcriptional regulation of metabolic genes in the liver is the key to maintaining systemic energy homeostasis during starvation. The membrane-bound transcription factor cAMP-responsive element-binding protein 3-like 3 (CREB3L3) has been reported to be activated during fasting and to regulate triglyceride metabolism. Here, we show that CREB3L3 confers a wide spectrum of metabolic responses to starvation in vivo. Adenoviral and transgenic overexpression of nuclear CREB3L3 induced systemic lipolysis, hepatic ketogenesis, and insulin sensitivity with increased energy expenditure, leading to marked reduction in body weight, plasma lipid levels, and glucose levels. CREB3L3 overexpression activated gene expression levels and plasma levels of antidiabetic hormones, including fibroblast growth factor 21 and IGF-binding protein 2. Amelioration of diabetes by hepatic activation of CREB3L3 was also observed in several types of diabetic obese mice. Nuclear CREB3L3 mutually activates the peroxisome proliferator-activated receptor (PPAR) α promoter in an autoloop fashion and is crucial for the ligand transactivation of PPARα by interacting with its transcriptional regulator, peroxisome proliferator-activated receptor gamma coactivator-1α. CREB3L3 directly and indirectly controls fibroblast growth factor 21 expression and its plasma level, which contributes at least partially to the catabolic effects of CREB3L3 on systemic energy homeostasis in the entire body. Therefore, CREB3L3 is a therapeutic target for obesity and diabetes.

Distinct Signaling Pathways Mediate Stimulation of Cell Cycle Progression and Prevention of Apoptotic Cell Death by Estrogen in Rat Pituitary Tumor PR1 Cells

PubMed Central

Caporali, Simona; Imai, Manami; Altucci, Lucia; Cancemi, Massimo; Caristi, Silvana; Cicatiello, Luigi; Matarese, Filomena; Penta, Roberta; Sarkar, Dipak K.; Bresciani, Francesco; Weisz, Alessandro

2003-01-01

Estrogens control cell growth and viability in target cells via an interplay of genomic and extragenomic pathways not yet elucidated. Here, we show evidence that cell proliferation and survival are differentially regulated by estrogen in rat pituitary tumor PR1 cells. Pico- to femtomolar concentrations of 17β-estradiol (E2) are sufficient to foster PR1 cell proliferation, whereas nanomolar concentrations of the same are needed to prevent cell death that occurs at a high rate in these cells in the absence of hormone. Activation of endogenous (PRL) or transfected estrogen-responsive genes occurs at the same, higher concentrations of E2 required to promote cell survival, whereas stimulation of cyclin D3 expression and DNA synthesis occur at lower E2 concentrations. Similarly, the pure antiestrogen ICI 182,780 inhibits estrogen response element-dependent trans-activation and cell death more effectively than cyclin-cdk activity, G1-S transition, or DNA synthesis rate. In antiestrogen-treated and/or estrogen-deprived cells, death is due predominantly to apoptosis. Estrogen-induced cell survival, but not E2-dependent cell cycle progression, can be prevented by an inhibitor of c-Src kinase or by blockade of the mitogen-activated protein kinase kinase/extracellular signal-regulated kinase signaling pathway. These data indicate the coexistence of two distinguishable estrogen signaling pathways in PR1 cells, characterized by different functions and sensitivity to hormones and antihormones. PMID:12960425

Evaluation of estrogen receptor alpha activation by glyphosate-based herbicide constituents.

PubMed

Mesnage, Robin; Phedonos, Alexia; Biserni, Martina; Arno, Matthew; Balu, Sucharitha; Corton, J Christopher; Ugarte, Ricardo; Antoniou, Michael N

2017-10-01

The safety, including the endocrine disruptive capability, of glyphosate-based herbicides (GBHs) is a matter of intense debate. We evaluated the estrogenic potential of glyphosate, commercial GBHs and polyethoxylated tallowamine adjuvants present as co-formulants in GBHs. Glyphosate (≥10,000 μg/L or 59 μM) promoted proliferation of estrogen-dependent MCF-7 human breast cancer cells. Glyphosate also increased the expression of an estrogen response element-luciferase reporter gene (ERE-luc) in T47D-KBluc cells, which was blocked by the estrogen antagonist ICI 182,780. Commercial GBH formulations or their adjuvants alone did not exhibit estrogenic effects in either assay. Transcriptomics analysis of MCF-7 cells treated with glyphosate revealed changes in gene expression reflective of hormone-induced cell proliferation but did not overlap with an ERα gene expression biomarker. Calculation of glyphosate binding energy to ERα predicts a weak and unstable interaction (-4.10 kcal mol -1 ) compared to estradiol (-25.79 kcal mol -1 ), which suggests that activation of this receptor by glyphosate is via a ligand-independent mechanism. Induction of ERE-luc expression by the PKA signalling activator IBMX shows that ERE-luc is responsive to ligand-independent activation, suggesting a possible mechanism of glyphosate-mediated activation. Our study reveals that glyphosate, but not other components present in GBHs, can activate ERα in vitro, albeit at relatively high concentrations. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Glycolysis determines dichotomous regulation of T cell subsets in hypoxia

PubMed Central

Xu, Yang; Zhang, Ming; Savoldo, Barbara; Metelitsa, Leonid S.; Rodgers, John; Yustein, Jason T.; Neilson, Joel R.

2016-01-01

Hypoxia occurs in many pathological conditions, including chronic inflammation and tumors, and is considered to be an inhibitor of T cell function. However, robust T cell responses occur at many hypoxic inflammatory sites, suggesting that functions of some subsets are stimulated under low oxygen conditions. Here, we investigated how hypoxic conditions influence human T cell functions and found that, in contrast to naive and central memory T cells (TN and TCM), hypoxia enhances the proliferation, viability, and cytotoxic action of effector memory T cells (TEM). Enhanced TEM expansion in hypoxia corresponded to high hypoxia-inducible factor 1α (HIF1α) expression and glycolytic activity compared with that observed in TN and TCM. We determined that the glycolytic enzyme GAPDH negatively regulates HIF1A expression by binding to adenylate-uridylate–rich elements in the 3′-UTR region of HIF1A mRNA in glycolytically inactive TN and TCM. Conversely, active glycolysis with decreased GAPDH availability in TEM resulted in elevated HIF1α expression. Furthermore, GAPDH overexpression reduced HIF1α expression and impaired proliferation and survival of T cells in hypoxia, indicating that high glycolytic metabolism drives increases in HIF1α to enhance TEM function during hypoxia. This work demonstrates that glycolytic metabolism regulates the translation of HIF1A to determine T cell responses to hypoxia and implicates GAPDH as a potential mechanism for controlling T cell function in peripheral tissue. PMID:27294526

Food consumption increases cell proliferation in the python brain.

PubMed

Habroun, Stacy S; Schaffner, Andrew A; Taylor, Emily N; Strand, Christine R

2018-04-06

Pythons are model organisms for investigating physiological responses to food intake. While systemic growth in response to food consumption is well documented, what occurs in the brain is currently unexplored. In this study, male ball pythons ( Python regius ) were used to test the hypothesis that food consumption stimulates cell proliferation in the brain. We used 5-bromo-12'-deoxyuridine (BrdU) as a cell-birth marker to quantify and compare cell proliferation in the brain of fasted snakes and those at 2 and 6 days after a meal. Throughout the telencephalon, cell proliferation was significantly increased in the 6 day group, with no difference between the 2 day group and controls. Systemic postprandial plasticity occurs quickly after a meal is ingested, during the period of active digestion; however, the brain displays a surge of cell proliferation after most digestion and absorption is complete. © 2018. Published by The Company of Biologists Ltd.

Analysis of the Heat Shock Response in Mouse Liver Reveals Transcriptional Dependence on the Nuclear Receptor Peroxisome Proliferator-Activated Receptor alpha (PPARα)

EPA Science Inventory

BACKGROUND: The nuclear receptor peroxisome proliferator-activated receptor alpha (PPARalpha) regulates responses to chemical or physical stress in part by altering expression of genes involved in proteome maintenance. Many of these genes are also transcriptionally regulated by h...

RODENT AND HUMAN NEUROPROGENITOR CELLS FOR HIGH-CONTENT SCREENS OF CHEMICAL EFFECTS ON PROLIFERATION AND APOPTOSIS

EPA Science Inventory

The objective of these experiments is to develop high-throughput screens for proliferation and apoptosis in order to compare rodent and human neuroprogenitor cell responses to potential developmental neurotoxicants. Effects of 4 chemicals on proliferation and apoptosis in mouse c...

Slow and sustained nitric oxide releasing compounds inhibit multipotent vascular stem cell proliferation and differentiation without causing cell death

DOE Office of Scientific and Technical Information (OSTI.GOV)

Curtis, Brandon M.; Leix, Kyle Alexander; Ji, Yajing

Highlights: • Multipotent vascular stem cells (MVSCs) proliferate and differentiate. • Nitric oxide inhibits proliferation of MVSCs. • Nitric oxide inhibits MVSC differentiation to mesenchymal-like stem cells (MSCs). • Smooth muscle cells (SMCs) neither de-differentiate nor proliferate. - Abstract: Atherosclerosis is the leading cause of cerebral and myocardial infarction. It is believed that neointimal growth common in the later stages of atherosclerosis is a result of vascular smooth muscle cell (SMC) de-differentiation in response to endothelial injury. However, the claims of the SMC de-differentiation theory have not been substantiated by monitoring the fate of mature SMCs in response to suchmore » injuries. A recent study suggests that atherosclerosis is a consequence of multipotent vascular stem cell (MVSC) differentiation. Nitric oxide (NO) is a well-known mediator against atherosclerosis, in part because of its inhibitory effect on SMC proliferation. Using three different NO-donors, we have investigated the effects of NO on MVSC proliferation. Results indicate that NO inhibits MVSC proliferation in a concentration dependent manner. A slow and sustained delivery of NO proved to inhibit proliferation without causing cell death. On the other hand, larger, single-burst NO concentrations, inhibits proliferation, with concurrent significant cell death. Furthermore, our results indicate that endogenously produced NO inhibits MVSC differentiation to mesenchymal-like stem cells (MSCs) and subsequently to SMC as well.« less

EBP1 is a novel E2F target gene regulated by transforming growth factor-β.

PubMed

Judah, David; Chang, Wing Y; Dagnino, Lina

2010-11-10

Regulation of gene expression requires transcription factor binding to specific DNA elements, and a large body of work has focused on the identification of such sequences. However, it is becoming increasingly clear that eukaryotic transcription factors can exhibit widespread, nonfunctional binding to genomic DNA sites. Conversely, some of these proteins, such as E2F, can also modulate gene expression by binding to non-consensus elements. E2F comprises a family of transcription factors that play key roles in a wide variety of cellular functions, including survival, differentiation, activation during tissue regeneration, metabolism, and proliferation. E2F factors bind to the Erb3-binding protein 1 (EBP1) promoter in live cells. We now show that E2F binding to the EBP1 promoter occurs through two tandem DNA elements that do not conform to typical consensus E2F motifs. Exogenously expressed E2F1 activates EBP1 reporters lacking one, but not both sites, suggesting a degree of redundancy under certain conditions. E2F1 increases the levels of endogenous EBP1 mRNA in breast carcinoma and other transformed cell lines. In contrast, in non-transformed primary epidermal keratinocytes, E2F, together with the retinoblastoma family of proteins, appears to be involved in decreasing EBP1 mRNA abundance in response to growth inhibition by transforming growth factor-β1. Thus, E2F is likely a central coordinator of multiple responses that culminate in regulation of EBP1 gene expression, and which may vary depending on cell type and context.

Dual‑sensitive HRE/Egr1 promoter regulates Smac overexpression and enhances radiation‑induced A549 human lung adenocarcinoma cell death under hypoxia.

PubMed

Li, Chang-Feng; Chen, Li-Bo; Li, Dan-Dan; Yang, Lei; Zhang, Bao-Gang; Jin, Jing-Peng; Zhang, Ying; Zhang, Bin

2014-08-01

The aim of this study was to construct an expression vector carrying the hypoxia/radiation dual‑sensitive chimeric hypoxia response element (HRE)/early growth response 1 (Egr‑1) promoter in order to overexpress the therapeutic second mitochondria‑derived activator of caspases (Smac). Using this expression vector, the present study aimed to explore the molecular mechanism underlying radiotherapy‑induced A549 human lung adenocarcinoma cell death and apoptosis under hypoxia. The plasmids, pcDNA3.1‑Egr1‑Smac (pE‑Smac) and pcDNA3.1‑HRE/Egr-1‑Smac (pH/E‑Smac), were constructed and transfected into A549 human lung adenocarcinoma cells using the liposome method. CoCl2 was used to chemically simulate hypoxia, followed by the administration of 2 Gy X‑ray irradiation. An MTT assay was performed to detect cell proliferation and an Annexin V‑fluorescein isothiocyanate apoptosis detection kit was used to detect apoptosis. Quantitative polymerase chain reaction and western blot analyses were used for the detection of mRNA and protein expression, respectively. Infection with the pE‑Smac and pH/E‑Smac plasmids in combination with radiation and/or hypoxia was observed to enhance the expression of Smac. Furthermore, Smac overexpression was found to enhance the radiation‑induced inhibition of cell proliferation and promotion of cycle arrest and apoptosis. The cytochrome c/caspase‑9/caspase‑3 pathway was identified to be involved in this regulation of apoptosis. Plasmid infection in combination with X‑ray irradiation was found to markedly induce cell death under hypoxia. In conclusion, the hypoxia/radiation dual‑sensitive chimeric HRE/Egr‑1 promoter was observed to enhance the expression of the therapeutic Smac, as well as enhance the radiation‑induced inhibition of cell proliferation and promotion of cycle arrest and apoptosis under hypoxia. This apoptosis was found to involve the mitochondrial pathway.

Transcriptional Dynamics of LTR Retrotransposons in Early Generation and Ancient Sunflower Hybrids

PubMed Central

Ungerer, Mark C.; Kawakami, Takeshi

2013-01-01

Hybridization and abiotic stress are natural agents hypothesized to influence activation and proliferation of transposable elements in wild populations. In this report, we examine the effects of these agents on expression dynamics of both quiescent and transcriptionally active sublineages of long terminal repeat (LTR) retrotransposons in wild sunflower species with a notable history of transposable element proliferation. For annual sunflower species Helianthus annuus and H. petiolaris, neither early generation hybridization nor abiotic stress, alone or in combination, induced transcriptional activation of quiescent sublineages of LTR retrotransposons. These treatments also failed to further induce expression of sublineages that are transcriptionally active; instead, expression of active sublineages in F1 and backcross hybrids was nondistinguishable from, or intermediate relative to, parental lines, and abiotic stress generally decreased normalized expression relative to controls. In contrast to findings for early generation hybridization between H. annuus and H. petiolaris, ancient sunflower hybrid species derived from these same two species and which have undergone massive proliferation events of LTR retrotransposons display 2× to 6× higher expression levels of transcriptionally active sublineages relative to parental sunflower species H. annuus and H. petiolaris. Implications and possible explanations for these findings are discussed. PMID:23335122

Structure and Expression of Hybrid Dysgenesis-Induced Alleles of the Ovarian Tumor (Otu) Gene in Drosophila Melanogaster

PubMed Central

Sass, G. L.; Mohler, J. D.; Walsh, R. C.; Kalfayan, L. J.; Searles, L. L.

1993-01-01

Mutations at the ovarian tumor (otu) gene of Drosophila melanogaster cause female sterility and generate a range of ovarian phenotypes. Quiescent (QUI) mutants exhibit reduced germ cell proliferation; in oncogenic (ONC) mutants germ cells undergo uncontrolled proliferation generating excessive numbers of undifferentiated cells; the egg chambers of differentiated (DIF) mutants differentiate to variable degrees but fail to complete oogenesis. We have examined mutations caused by insertion and deletion of P elements at the otu gene. The P element insertion sites are upstream of the major otu transcription start sites. In deletion derivatives, the P element, regulatory regions and/or protein coding sequences have been removed. In both insertion and deletion mutants, the level of otu expression correlates directly with the severity of the phenotype: the absence of otu function produces the most severe QUI phenotype while the ONC mutants express lower levels of otu than those which are DIF. The results of this study demonstrate that the diverse mutant phenotypes of otu are the consequence of different levels of otu function. PMID:8436274

Low proliferation and high apoptosis of osteoblastic cells on hydrophobic surface are associated with defective Ras signaling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang, Eun-Ju; Kim, Hong-Hee; Huh, Jung-Eun

2005-02-01

The hydrophobic (HPB) nature of most polymeric biomaterials has been a major obstacle in using those materials in vivo due to low compatibility with cells. However, there is little knowledge of the molecular detail to explain how surface hydrophobicity affects cell responses. In this study, we compared the proliferation and apoptosis of human osteoblastic MG63 cells adhered to hydrophilic (HPL) and hydrophobic surfaces. On the hydrophobic surface, less formation of focal contacts and actin stress fibers, a delay in cell cycle progression, and an increase in apoptosis were observed. By using fibroblast growth factor 1 (FGF1) as a model growthmore » factor, we also investigated intracellular signaling pathways on hydrophilic and hydrophobic surfaces. The activation of Ras, Akt, and ERK by FGF1 was impaired in MG63 cells on the hydrophobic surface. The overexpression of constitutively active form of Ras and Akt rescued those cells from apoptosis and recovered cell cycle progression. Furthermore, their overexpression also restored the actin cytoskeletal organization on the hydrophobic surface. Finally, the proliferative, antiapoptotic, and cytoskeletal effects of constitutively active Ras in MG63 cells on the hydrophobic surface were blocked by wortmannin and PD98059 that inhibit Akt and ERK activation, respectively. Therefore, our results suggest that the activation of Ras and its downstream molecules Akt and ERK to an appropriate level is one of crucial elements in the determination of osteoblast cell responses. The Ras pathway may represent a cell biological target that should be considered for successful surface modification of biomaterials to induce adequate cell responses in the bone tissue.« less

Zinc Promotes Adipose-Derived Mesenchymal Stem Cell Proliferation and Differentiation towards a Neuronal Fate

PubMed Central

Moon, Mi-Young; Kim, Hyun Jung; Choi, Bo Young; Sohn, Min

2018-01-01

Zinc is an essential element required for cell division, migration, and proliferation. Under zinc-deficient conditions, proliferation and differentiation of neural progenitors are significantly impaired. Adipose-derived mesenchymal stem cells (AD-MSCs) are multipotent stem cells that can differentiate into neurons. The aim of this study was to evaluate the effect of zinc on AD-MSC proliferation and differentiation. We initially examined the effect of zinc on stem cell proliferation at the undifferentiated stage. AD-MSCs showed high proliferation rates on day 6 in 30 μM and 100 μM of ZnCl2. Zinc chelation inhibited AD-MSC proliferation via downregulation of ERK1/2 activity. We then assessed whether zinc was involved in cell migration and neurite outgrowth during differentiation. After three days of neuronal differentiation, TUJ-1-positive cells were observed, implying that AD-MSCs had differentiated into early neuron or neuron-like cells. Neurite outgrowth was increased in the zinc-treated group, while the CaEDTA-treated group showed diminished, shrunken neurites. Furthermore, we showed that zinc promoted neurite outgrowth via the inactivation of RhoA and led to the induction of neuronal gene expression (MAP2 and nestin) in differentiated stem cells. Taken together, zinc promoted AD-MSC proliferation and affected neuronal differentiation, mainly by increasing neurite outgrowth. PMID:29765417

P44/WDR77 restricts the sensitivity of proliferating cells to TGFβ signaling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yi, Pengfei; Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030; Gao, Shen

2014-07-18

Highlights: • P44/WDR77 causes proliferating cells to become non-responsive to TGFβ signaling. • P44/WDR77 down-regulates TβRII and TβR2 expression. • P44/WDR77 down-regulated TGFβ signaling correlates with lung tumorigenesis. - Abstract: We previously reported that a novel WD-40 domain-containing protein, p44/WDR77, drives quiescent epithelial cells to re-enter the cell cycle and plays an essential role for growth of lung and prostate cancer cells. Transforming growth factor beta (TGFβ) signaling is important in the maintenance of non-transformed cells in the quiescent or slowly cycling stage. However, both non-transformed proliferating cells and human cancer cells are non-responsive to endogenous TGFβ signaling. The mechanismmore » by which proliferating cells become refractory to TGFβ inhibition is not well established. Here, we found that silencing p44/WDR77 increased cellular sensitivity to TGFβ signaling and that this was inversely correlated with decreased cell proliferation. Smad2 or 3 phosphorylation, TGFβ-mediated transcription, and TGFβ2 and TGFβ receptor type II (TβRII) expression were dramatically induced by silencing of p44/WDR77. These data support the hypothesis that p44/WDR77 down-regulates the expression of the TGFβ ligand and its receptor, thereby leading to a cellular non-response to TGFβ signaling. Finally, we found that p44/WDR77 expression was correlated with cell proliferation and decreased TGFβ signaling during lung tumorigenesis. Together, these results suggest that p44/WDR77 expression causes the non-sensitivity of proliferating cells to TGFβ signaling, thereby contributing to cellular proliferation during lung tumorigenesis.« less

Resolving Heart Regeneration by Replacement Histone Profiling.

PubMed

Goldman, Joseph Aaron; Kuzu, Guray; Lee, Nutishia; Karasik, Jaclyn; Gemberling, Matthew; Foglia, Matthew J; Karra, Ravi; Dickson, Amy L; Sun, Fei; Tolstorukov, Michael Y; Poss, Kenneth D

2017-02-27

Chromatin regulation is a principal mechanism governing animal development, yet it is unclear to what extent structural changes in chromatin underlie tissue regeneration. Non-mammalian vertebrates such as zebrafish activate cardiomyocyte (CM) division after tissue damage to regenerate lost heart muscle. Here, we generated transgenic zebrafish expressing a biotinylatable H3.3 histone variant in CMs and derived cell-type-specific profiles of histone replacement. We identified an emerging program of putative enhancers that revise H3.3 occupancy during regeneration, overlaid upon a genome-wide reduction of H3.3 from promoters. In transgenic reporter lines, H3.3-enriched elements directed gene expression in subpopulations of CMs. Other elements increased H3.3 enrichment and displayed enhancer activity in settings of injury- and/or Neuregulin1-elicited CM proliferation. Dozens of consensus sequence motifs containing predicted transcription factor binding sites were enriched in genomic regions with regeneration-responsive H3.3 occupancy. Thus, cell-type-specific regulatory programs of tissue regeneration can be revealed by genome-wide H3.3 profiling. Copyright © 2017 Elsevier Inc. All rights reserved.

Disruption of transforming growth factor-beta signaling by curcumin induces gene expression of peroxisome proliferator-activated receptor-gamma in rat hepatic stellate cells.

PubMed

Zheng, Shizhong; Chen, Anping

2007-01-01

Activation of hepatic stellate cells (HSC), the major effectors of hepatic fibrogenesis, is coupled with sequential alterations in gene expression, including an increase in receptors for transforming growth factor-beta (TGF-beta) and a dramatic reduction in the peroxisome proliferator-activated receptor-gamma (PPAR-gamma). The relationship between them remains obscure. We previously demonstrated that curcumin induced gene expression of PPAR-gamma in activated HSC, leading to reducing cell proliferation, inducing apoptosis and suppressing expression of extracellular matrix genes. The underlying molecular mechanisms are largely unknown. We recently observed that stimulation of PPAR-gamma activation suppressed gene expression of TGF-beta receptors in activated HSC, leading to the interruption of TGF-beta signaling. This observation supported our assumption of an antagonistic relationship between PPAR-gamma activation and TGF-beta signaling in HSC. In this study, we further hypothesize that TGF-beta signaling might negatively regulate gene expression of PPAR-gamma in activated HSC. The present report demonstrates that exogenous TGF-beta1 inhibits gene expression of PPAR-gamma in activated HSC, which is eliminated by the pretreatment with curcumin likely by interrupting TGF-beta signaling. Transfection assays further indicate that blocking TGF-beta signaling by dominant negative type II TGF-beta receptor increases the promoter activity of PPAR-gamma gene. Promoter deletion assays, site-directed mutageneses, and gel shift assays localize two Smad binding elements (SBEs) in the PPAR-gamma gene promoter, acting as curcumin response elements and negatively regulating the promoter activity in passaged HSC. The Smad3/4 protein complex specifically binds to the SBEs. Overexpression of Smad4 dose dependently eliminates the inhibitory effects of curcumin on the PPAR-gamma gene promoter and TGF-beta signaling. Taken together, these results demonstrate that the interruption of TGF-beta signaling by curcumin induces gene expression of PPAR-gamma in activated HSC in vitro. Our studies provide novel insights into the molecular mechanisms of curcumin in the induction of PPAR-gamma gene expression and in the inhibition of HSC activation.

24-Methylenecycloartanyl ferulate, a major compound of γ-oryzanol, promotes parvin-beta expression through an interaction with peroxisome proliferator-activated receptor-gamma 2 in human breast cancer cells.

PubMed

Kim, Heon Woong; Lim, Eun Joung; Jang, Hwan Hee; Cui, XueLei; Kang, Da Rae; Lee, Sung Hyen; Kim, Haeng Ran; Choe, Jeong Sook; Yang, Young Mok; Kim, Jung Bong; Park, Jong Hwan

2015-12-25

Parvin-β is an adaptor protein that binds to integrin-linked kinase (ILK) and is significantly downregulated in breast tumors and breast cancer cell lines. We treated the breast cancer cell line MCF7 with 24-methylenecycloartanyl ferulate (24-MCF), a γ-oryzanol compound. We observed upregulation of parvin-β (GenBank Accession No. AF237769) and peroxisome proliferator-activated receptor (PPAR)-γ2 (GenBank Accession No. NM_015869). Among γ-oryzanol compounds, only treatment with 24-MCF led to the formation of reverse transcription-PCR products of parvin-β (650 and 500 bp) and PPAR-γ2 (580 bp) in MCF7 cells, but not in T47D, SK-BR-3, or MDA-MB-231 cells. 24-MCF treatment increased the mRNA and protein levels of parvin-β in MCF7 cells in a dose-dependent manner. We hypothesized that there is a correlation between parvin-β expression and induction of PPAR-γ2. This hypothesis was investigated by using a promoter-reporter assay, chromatin immunoprecipitation, and an electrophoretic mobility shift assay. 24-MCF treatment induced binding of PPAR-γ2 to a peroxisome proliferator response element-like cis-element (ACTAGGACAAAGGACA) in the parvin-β promoter in MCF7 cells in a dose-dependent manner. 24-MCF treatment significantly decreased anchorage-independent growth and inhibited cell movement in comparison to control treatment with dimethyl sulfoxide. 24-MCF treatment reduced the levels of GTP-bound Rac1 and Cdc42. Evaluation of Akt1 inhibition by 24-MCF revealed that the half maximal effective concentration was 33.3 μM. Docking evaluations revealed that 24-MCF binds to the ATP-binding site of Akt1(PDB ID: 3OCB) and the compound binding energy is -8.870 kcal/mol. Taken together, our results indicate that 24-MCF treatment increases parvin-β expression, which may inhibit ILK downstream signaling. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Fibroblast proliferation alters cardiac excitation conduction and contraction: a computational study.

PubMed

Zhan, He-qing; Xia, Ling; Shou, Guo-fa; Zang, Yun-liang; Liu, Feng; Crozier, Stuart

2014-03-01

In this study, the effects of cardiac fibroblast proliferation on cardiac electric excitation conduction and mechanical contraction were investigated using a proposed integrated myocardial-fibroblastic electromechanical model. At the cellular level, models of the human ventricular myocyte and fibroblast were modified to incorporate a model of cardiac mechanical contraction and cooperativity mechanisms. Cellular electromechanical coupling was realized with a calcium buffer. At the tissue level, electrical excitation conduction was coupled to an elastic mechanics model in which the finite difference method (FDM) was used to solve electrical excitation equations, and the finite element method (FEM) was used to solve mechanics equations. The electromechanical properties of the proposed integrated model were investigated in one or two dimensions under normal and ischemic pathological conditions. Fibroblast proliferation slowed wave propagation, induced a conduction block, decreased strains in the fibroblast proliferous tissue, and increased dispersions in depolarization, repolarization, and action potential duration (APD). It also distorted the wave-front, leading to the initiation and maintenance of re-entry, and resulted in a sustained contraction in the proliferous areas. This study demonstrated the important role that fibroblast proliferation plays in modulating cardiac electromechanical behaviour and which should be considered in planning future heart-modeling studies.

Fibroblast proliferation alters cardiac excitation conduction and contraction: a computational study*

PubMed Central

Zhan, He-qing; Xia, Ling; Shou, Guo-fa; Zang, Yun-liang; Liu, Feng; Crozier, Stuart

2014-01-01

In this study, the effects of cardiac fibroblast proliferation on cardiac electric excitation conduction and mechanical contraction were investigated using a proposed integrated myocardial-fibroblastic electromechanical model. At the cellular level, models of the human ventricular myocyte and fibroblast were modified to incorporate a model of cardiac mechanical contraction and cooperativity mechanisms. Cellular electromechanical coupling was realized with a calcium buffer. At the tissue level, electrical excitation conduction was coupled to an elastic mechanics model in which the finite difference method (FDM) was used to solve electrical excitation equations, and the finite element method (FEM) was used to solve mechanics equations. The electromechanical properties of the proposed integrated model were investigated in one or two dimensions under normal and ischemic pathological conditions. Fibroblast proliferation slowed wave propagation, induced a conduction block, decreased strains in the fibroblast proliferous tissue, and increased dispersions in depolarization, repolarization, and action potential duration (APD). It also distorted the wave-front, leading to the initiation and maintenance of re-entry, and resulted in a sustained contraction in the proliferous areas. This study demonstrated the important role that fibroblast proliferation plays in modulating cardiac electromechanical behaviour and which should be considered in planning future heart-modeling studies. PMID:24599687

Circulatory shear flow alters the viability and proliferation of circulating colon cancer cells

NASA Astrophysics Data System (ADS)

Fan, Rong; Emery, Travis; Zhang, Yongguo; Xia, Yuxuan; Sun, Jun; Wan, Jiandi

2016-06-01

During cancer metastasis, circulating tumor cells constantly experience hemodynamic shear stress in the circulation. Cellular responses to shear stress including cell viability and proliferation thus play critical roles in cancer metastasis. Here, we developed a microfluidic approach to establish a circulatory microenvironment and studied circulating human colon cancer HCT116 cells in response to a variety of magnitude of shear stress and circulating time. Our results showed that cell viability decreased with the increase of circulating time, but increased with the magnitude of wall shear stress. Proliferation of cells survived from circulation could be maintained when physiologically relevant wall shear stresses were applied. High wall shear stress (60.5 dyne/cm2), however, led to decreased cell proliferation at long circulating time (1 h). We further showed that the expression levels of β-catenin and c-myc, proliferation regulators, were significantly enhanced by increasing wall shear stress. The presented study provides a new insight to the roles of circulatory shear stress in cellular responses of circulating tumor cells in a physiologically relevant model, and thus will be of interest for the study of cancer cell mechanosensing and cancer metastasis.

T cells which proliferate in response to concanavalin A include cells which proliferate in mixed leucocyte reactions.

PubMed

Watanabe, T; Fathman, C G; Coutinho, A

1977-09-01

Selection in long-term culture of alloreactive T cells, by successive in vitro restimulation with semi-allogeneic cells, results in primed responder cell populations which maintain full proliferative reactivity to allogeneic cells as well as to the T cell mitogens concanavalin A (Con A) and phytohemagglutinin (PHA) but are depleted of cells which can effect target cell destruction in either a specific or nonspecific manner. Con A-induced T cell blasts (selected by velocity sedimentation) can revert to small resting lymphocytes in the presence of inert "filler" cells. Con A blasts which have reverted, readily proliferate in response to Con A or allogeneic stimulator cells but are largely depleted of effector killer cells and PHA-responsive cells.

Possible influence of infrasound on glioma cell response to chemotherapy: a pilot study.

PubMed

Yount, Garret; Taft, Ryan; West, Jeremy; Moore, Dan

2004-04-01

To assess the response of cultured human tumor cells to infrasound in combination with conventional anticancer agents using an infrasound-emitting apparatus marketed as a therapeutic device. Two pilot experiments measured proliferation of cultured brain tumor cells exposed to three treatment conditions: infrasound emission alone, infrasound in combination with the chemotherapy 5-fluorouracil (5-FU), and infrasound in combination with ionizing radiation. Results from each experimental condition were compared to those from appropriate control conditions. A standard colony-forming efficiency assay was used to assess tumor cell proliferation. Tumor cell proliferation was not significantly altered by treatment with infrasound alone, nor did infrasound appear to influence cellular response to x-rays. There was a significant interaction between 5-FU and infrasound (P < 0.0001), however, evident in decreased colony formation. Further research is warranted to assess potential synergism between infrasound and 5-FU against tumor cell proliferation, and to investigate the possible therapeutic use of infrasound.

ER Stress: A Therapeutic Target in Rheumatoid Arthritis?

PubMed

Rahmati, Marveh; Moosavi, Mohammad Amin; McDermott, Michael F

2018-04-22

Diverse physiological and pathological conditions that impact on protein folding of the endoplasmic reticulum (ER) cause ER stress. The unfolded protein response (UPR) and the ER-associated degradation (ERAD) pathway are activated to cope with ER stress. In rheumatoid arthritis (RA), inflammation and ER stress work in parallel by driving inflammatory cells to release cytokines that induce chronic ER stress pathways. This chronic ER stress may contribute to the pathogenesis of RA through synoviocyte proliferation and proinflammatory cytokine production. Therefore, ER stress pathways and their constituent elements are attractive targets for RA drug development. In this review, we integrate current knowledge of the contribution of ER stress to the overall pathogenesis of RA, and suggest some therapeutic implications of these discoveries. Copyright © 2018 Elsevier Ltd. All rights reserved.

Fish community responses to green tides in shallow estuarine and coastal areas

NASA Astrophysics Data System (ADS)

Le Luherne, E.; Réveillac, E.; Ponsero, A.; Sturbois, A.; Ballu, S.; Perdriau, M.; Le Pape, O.

2016-06-01

All over the world, numerous bays and estuarine systems that are known to shelter essential fish habitats are experiencing proliferations of green macroalgae known as green tides. Although the processes that enhance green tides in response to nutrient enrichment are well known, their consequences for ecological communities -especially for ichthyofauna- remain poorly studied. To estimate these consequences, this analysis focused on the two types of shallow systems that are experiencing green tides: sandy beaches and estuarine mudflats. In these two systems, macroalgae proliferation and fish community were surveyed along seasonal cycles at control and impacted sites that shared similar physico-chemical parameters and sediment structure. To analyse the consequences of green tides on the fish community, a Before-After Control-Impact approach was used. This approach reveals no difference between fish communities at the control and impacted sites before the macroalgal bloom. Then, it underlines an influence of green tides on the fish community, and this influence varies according to the composition, density and duration of the macroalgal bloom. Indeed, when intertidal systems experienced short proliferation and/or weak density, green tides did not seem to impact the fish community. However, when green macroalgae proliferated in large quantities and/or when the proliferation lasted for long periods, the fish community was significantly affected. These modifications in the fish community led to a significant decrease in fish species diversity and density until fish disappeared from impacted sites at high proliferations. Furthermore, the response of fish species to green tides differed according to their functional guilds. Negative consequences for benthic and marine juvenile fish species were beginning at low proliferations, whereas for pelagic fish species they occurred only at high proliferations. Thus, green tides significantly affect fish habitat suitability because they lead to changes in the composition of the fish community and eventually to the local disappearance of fish at high proliferations.

Opuntia ficus-indica seed attenuates hepatic steatosis and promotes M2 macrophage polarization in high-fat diet-fed mice.

PubMed

Kang, Jung-Woo; Shin, Jun-Kyu; Koh, Eun-Ji; Ryu, Hyojeong; Kim, Hyoung Ja; Lee, Sun-Mee

2016-04-01

Opuntia ficus-indica (L.) is a popular edible plant that possesses considerable nutritional value and exhibits diverse biological actions including anti-inflammatory and antidiabetic activities. In this study, we hypothesized that DWJ504, an extract of O ficus-indica seed, would ameliorate hepatic steatosis and inflammation by regulating hepatic de novo lipogenesis and macrophage polarization against experimental nonalcoholic steatohepatitis. Mice were fed a normal diet or a high-fat diet (HFD) for 10 weeks. DWJ504 (250, 500, and 1000 mg/kg) or vehicle (0.5% carboxymethyl cellulose) were orally administered for the last 4 weeks of the 10-week HFD feeding period. DWJ504 treatment remarkably attenuated HFD-induced increases in hepatic lipid content and hepatocellular damage. DWJ504 attenuated increases in sterol regulatory element-binding protein 1 and carbohydrate-responsive element-binding protein expression and a decrease in carnitine palmitoyltransferase 1A. Although DWJ504 augmented peroxisome proliferator-activated receptor α protein expression, it attenuated peroxisome proliferator-activated receptor γ expression. Moreover, DWJ504 promoted hepatic M2 macrophage polarization as indicated by attenuation of the M1 marker genes and enhancement of M2 marker genes. Finally, DWJ504 attenuated expression of toll-like receptor 4, nuclear factor κB, tumor necrosis factor α, interleukin 6, TIR-domain-containing adapter-inducing interferon β, and interferon β levels. Our results demonstrate that DWJ504 prevented intrahepatic lipid accumulation, induced M2 macrophage polarization, and suppressed the toll-like receptor 4-mediated inflammatory signaling pathway. Thus, DWJ504 has therapeutic potential in the prevention of nonalcoholic fatty liver disease. Copyright © 2016 Elsevier Inc. All rights reserved.

Upregulation of human heme oxygenase gene expression by Ets-family proteins.

PubMed

Deramaudt, B M; Remy, P; Abraham, N G

1999-03-01

Overexpression of human heme oxygenase-1 has been shown to have the potential to promote EC proliferation and angiogenesis. Since Ets-family proteins have been shown to play an important role in angiogenesis, we investigated the presence of ETS binding sites (EBS), GGAA/T, and ETS protein contributing to human HO-1 gene expression. Several chloramphenicol acetyltransferase constructs were examined in order to analyze the effect of ETS family proteins on the transduction of HO-1 in Xenopus oocytes and in microvessel endothelial cells. Heme oxygenase promoter activity was up-regulated by FLI-1ERGETS-1 protein(s). Chloramphenicol acetyltransferase (CAT) assays demonstrated that the promoter region (-1500 to +19) contains positive and negative control elements and that all three members of the ETS protein family were responsible for the up-regulation of HHO-1. Electrophoretic mobility shift assays (EMSA), performed with nuclear extracts from endothelial cells overexpressing HHO-1 gene, and specific HHO-1 oligonucleotides probes containing putative EBS resulted in a specific and marked bandshift. Synergistic binding was observed in EMSA between AP-1 on the one hand, FLI-1, ERG, and ETS-1 protein on the other. Moreover, 5'-deletion analysis demonstrated the existence of a negative control element of HHO-1 expression located between positions -1500 and -120 on the HHO-1 promoter. The presence of regulatory sequences for transcription factors such as ETS-1, FLI-1, or ERG, whose activity is associated with cell proliferation, endothelial cell differentiation, and matrix metalloproteinase transduction, may be an indication of the important role that HO-1 may play in coronary collateral circulation, tumor growth, angiogenesis, and hemoglobin-induced endothelial cell injuries.

Micropropagation of pear (Pyrus sp)

USDA-ARS?s Scientific Manuscript database

Establishment of shoot tip cultures, proliferation, rooting, and acclimatization of the resulting plantlets are all elements of micropropagation. The great genetic variation in Pyrus (pear)makes micropropagation challenging for many genotypes. Initiation of shoots is most successful from forced do...

Role of T cells in the B-cell response: glutaraldehyde-fixed T-helper hybridoma cells synergize with the lymphokine IL-4 to induce B-cell activation and proliferation.

PubMed

Kubota, E; McKenzie, D T; Dutton, R W; Swain, S L

1991-01-01

Antigen-unselected helper T-cell hybridomas (Th) which activate normal resting B cells to RNA synthesis and proliferation in the presence of concanavalin A (Con A) have been developed. The response is completely Th cell dependent, and not restricted by the haplotype of the B-cell major histocompatibility complex (MHC). Culture supernatants from the Con A-stimulated Th hybridomas contain interleukin-4 (IL-4) and IL-2, but undetectable level of IL-5. The supernatant alone, however, does not induce B-cell activation or proliferation. Although the Con A-mediated Th cell-dependent B-cell response occurs in an MHC-unrestricted manner, the response of resting B cells can be blocked by monoclonal Ia antibody specific for the surface class II molecules of the responding B cell. The response is also blocked by monoclonal antibody to L3T4. Significant activation and proliferation of resting B cells can also be triggered by glutaraldehyde-fixed Th hybridomas and Con A when exogenous IL-4 is added. The stimulation with fixed Th hybridomas plus IL-4 can be inhibited by monoclonal anti-L3T4 or anti-Ia. These results suggest that maximal B-cell activation requires a direct helper T cell-B cell interaction which depends on availability of Ia on the B cell and L3T4 on the T cell, even when Con A overcomes the requirement for MHC-restricted T-cell recognition. We suggest that this signal, in conjunction with T-cell produced lymphokine IL-4, is responsible for the activation and subsequent proliferation of the B cells which occurs following interaction with T cells.

Promotion of chloroplast proliferation upon enhanced post-mitotic cell expansion in leaves.

PubMed

Kawade, Kensuke; Horiguchi, Gorou; Ishikawa, Naoko; Hirai, Masami Yokota; Tsukaya, Hirokazu

2013-09-28

Leaves are determinate organs; hence, precise control of cell proliferation and post-mitotic cell expansion is essential for their growth. A defect in cell proliferation often triggers enhanced post-mitotic cell expansion in leaves. This phenomenon is referred to as 'compensation'. Several lines of evidence from studies on compensation have shown that cell proliferation and post-mitotic cell expansion are coordinately regulated during leaf development. Therefore, compensation has attracted much attention to the mechanisms for leaf growth. However, our understanding of compensation at the subcellular level remains limited because studies of compensation have focused mainly on cellular-level phenotypes. Proper leaf growth requires quantitative control of subcellular components in association with cellular-level changes. To gain insight into the subcellular aspect of compensation, we investigated the well-known relationship between cell area and chloroplast number per cell in compensation-exhibiting lines, and asked whether chloroplast proliferation is modulated in response to the induction of compensation. We first established a convenient and reliable method for observation of chloroplasts in situ. Using this method, we analyzed Arabidopsis thaliana mutants fugu5 and angustifolia3 (an3), and a transgenic line KIP-RELATED PROTEIN2 overexpressor (KRP2 OE), which are known to exhibit typical features of compensation. We here showed that chloroplast number per cell increased in the subepidermal palisade tissue of these lines. We analyzed tetraploidized wild type, fugu5, an3 and KRP2 OE, and found that cell area itself, but not nuclear ploidy, is a key parameter that determines the activity of chloroplast proliferation. In particular, in the case of an3, we uncovered that promotion of chloroplast proliferation depends on the enhanced post-mitotic cell expansion. The expression levels of chloroplast proliferation-related genes are similar to or lower than that in the wild type during this process. This study demonstrates that chloroplast proliferation is promoted in compensation-exhibiting lines. This promotion of chloroplast proliferation takes place in response to cell-area increase in post-mitotic phase in an3. The expression of chloroplast proliferation-related genes were not promoted in compensation-exhibiting lines including an3, arguing that an as-yet-unknown mechanism is responsible for modulation of chloroplast proliferation in these lines.

Promotion of chloroplast proliferation upon enhanced post-mitotic cell expansion in leaves

PubMed Central

2013-01-01

Background Leaves are determinate organs; hence, precise control of cell proliferation and post-mitotic cell expansion is essential for their growth. A defect in cell proliferation often triggers enhanced post-mitotic cell expansion in leaves. This phenomenon is referred to as ‘compensation’. Several lines of evidence from studies on compensation have shown that cell proliferation and post-mitotic cell expansion are coordinately regulated during leaf development. Therefore, compensation has attracted much attention to the mechanisms for leaf growth. However, our understanding of compensation at the subcellular level remains limited because studies of compensation have focused mainly on cellular-level phenotypes. Proper leaf growth requires quantitative control of subcellular components in association with cellular-level changes. To gain insight into the subcellular aspect of compensation, we investigated the well-known relationship between cell area and chloroplast number per cell in compensation-exhibiting lines, and asked whether chloroplast proliferation is modulated in response to the induction of compensation. Results We first established a convenient and reliable method for observation of chloroplasts in situ. Using this method, we analyzed Arabidopsis thaliana mutants fugu5 and angustifolia3 (an3), and a transgenic line KIP-RELATED PROTEIN2 overexpressor (KRP2 OE), which are known to exhibit typical features of compensation. We here showed that chloroplast number per cell increased in the subepidermal palisade tissue of these lines. We analyzed tetraploidized wild type, fugu5, an3 and KRP2 OE, and found that cell area itself, but not nuclear ploidy, is a key parameter that determines the activity of chloroplast proliferation. In particular, in the case of an3, we uncovered that promotion of chloroplast proliferation depends on the enhanced post-mitotic cell expansion. The expression levels of chloroplast proliferation-related genes are similar to or lower than that in the wild type during this process. Conclusions This study demonstrates that chloroplast proliferation is promoted in compensation-exhibiting lines. This promotion of chloroplast proliferation takes place in response to cell-area increase in post-mitotic phase in an3. The expression of chloroplast proliferation-related genes were not promoted in compensation-exhibiting lines including an3, arguing that an as-yet-unknown mechanism is responsible for modulation of chloroplast proliferation in these lines. PMID:24074400

Effect of interlukin-1beta on proliferation of gastric epithelial cells in culture.

PubMed

Beales, Ian L P

2002-04-05

Helicobacter pylori is the main risk factor for the development of non-cardia gastric cancer. Increased proliferation of the gastric mucosa is a feature of H. pylori infection. Mucosal interkeukin-1beta production is increased in H. pylori infection and IL-1beta genotypes associated with increased pro-inflammatory activity are risk factors for the development of gastric cancer. The effect of IL-1beta on gastric epithelial cell proliferation has been examined in this study. AGS cells were cultured with IL-1beta. DNA synthesis was assed by [3H]thymidine incorporation and total viable cell numbers by MTT assay. IL-1beta dose dependently increased DNA synthesis and cell numbers. The enhanced proliferation was blocked by interleukin-1 receptor antagonist. Addition of neutralising antibody to GM-CSF reduced IL-1beta-stimulated proliferation by 31 +/- 4 %. GM-CSF alone significantly stimulated proliferation. Addition or neutralisation of IL-8 had no effect on basal or IL-1beta-stimulated proliferation. The tyrosine kinase inhibitor genistein completely blocked IL-1beta-stimulated proliferation and inhibition of the extracellular signal related kinase pathway with PD 98059 inhibited IL-1beta stimulated proliferation by 58 +/- 5 %. IL-1beta stimulates proliferation in gastric epithelial cells. Autocrine stimulation by GM-CSF contributes to this proliferative response. Signalling via tyrosine kinase activity is essential to the mitogenic response to IL-1beta. The extracellular signal related kinase pathway is involved in, but not essential to downstream signalling. IL-1beta may contribute to the hyperproliferation seen in H. pylori- infected gastric mucosa, and be involved in the carcinogenic process.

Potential role of peroxisome proliferator activated receptor gamma activation on serum visfatin and trace elements in high fat diet induced type 2 diabetes mellitus.

PubMed

Tabassum, Arshia; Zaidi, Syeda Nuzhat Fatima; Yasmeen, Kausar; Mahboob, Tabassum

2018-07-15

Electrolytes and trace elements dysregulation play an important role in the progression of obesity and diabetes complications. The present study was designed to evaluate the insulin sensitizing effects of peroxisomes proliferators activated receptor gamma (PPAR-γ) agonist on trace elements in obesity induced type 2 diabetes mellitus and correlate with serum visfatin. Wistar rats were categorized into five groups. Group I served as control; Group II fed on high fat diet (HFD); Group III fed on HFD and treated with rosiglitazone (3 mg/kg) for 7 days; Group IV were T2DM rats induce by HFD and low dose of streptozotocin (i.p. 35 mg/kg); Group V was T2DM rats treated with rosiglitazone (3 mg/kg) for 7 days. Serum and tissues electrolytes levels and renal, hepatic and cardiac tissues trace elements were estimated by flame photometer and atomic absorption spectroscopy. Serum visfatin was estimated by ELISA. Pearson correlations were analyzed among fasting blood glucose (FBG), serum visfatin and tissues trace elements. Results of the current study showed hyponatremia, hyperkalemia, hypomagnesemia and hypercalcemia in HFD and T2DM groups. HFD and T2DM also showed elevated copper and iron levels; however, zinc and selenium levels were decreased. Rosiglitazone treatment increased the insulin sensitization and altered these changes. A Strong association was observed among FBG, serum visfatin and trace elements levels of HFD and T2DM. Obesity and diabetes mellitus disturbed visfatin, electrolytes and trace elements homeostasis. Rosiglitazone treatment restored these changes. The results of the study could serve as a basis for further studies for the prevention of diabetic complications. Copyright © 2018 Elsevier Inc. All rights reserved.

Editor's Highlight: Development of an In vitro Assay Measuring Uterine-Specific Estrogenic Responses for Use in Chemical Safety Assessment.

PubMed

Miller, Michelle M; Alyea, Rebecca A; LeSommer, Caroline; Doheny, Daniel L; Rowley, Sean M; Childs, Kristin M; Balbuena, Pergentino; Ross, Susan M; Dong, Jian; Sun, Bin; Andersen, Melvin A; Clewell, Rebecca A

2016-11-01

A toxicity pathway approach was taken to develop an in vitro assay using human uterine epithelial adenocarcinoma (Ishikawa) cells as a replacement for measuring an in vivo uterotrophic response to estrogens. The Ishikawa cell was determined to be fit for the purpose of recapitulating in vivo uterine response by verifying fidelity of the biological pathway components and the dose-response predictions to women of child-bearing age. Expression of the suite of estrogen receptors that control uterine proliferation (ERα66, ERα46, ERα36, ERβ, G-protein coupled estrogen receptor (GPER)) were confirmed across passages and treatment conditions. Phenotypic responses to ethinyl estradiol (EE) from transcriptional activation of ER-mediated genes, to ALP enzyme induction and cellular proliferation occurred at concentrations consistent with estrogenic activity in adult women (low picomolar). To confirm utility of this model to predict concentration-response for uterine proliferation with xenobiotics, we tested the concentration-response for compounds with known uterine estrogenic activity in humans and compared the results to assays from the ToxCast and Tox21 suite of estrogen assays. The Ishikawa proliferation assay was consistent with in vivo responses and was a more sensitive measure of uterine response. Because this assay was constructed by first mapping the key molecular events for cellular response, and then ensuring that the assay incorporated these events, the resulting cellular assay should be a reliable tool for identifying estrogenic compounds and may provide improved quantitation of chemical concentration response for in vitro-based safety assessments. © The Author 2016. Published by Oxford University Press on behalf of the Society of Toxicology.

Involvement of neuron-derived orphan receptor-1 (NOR-1) in LDL-induced mitogenic stimulus in vascular smooth muscle cells: role of CREB.

PubMed

Rius, Jordi; Martínez-González, José; Crespo, Javier; Badimon, Lina

2004-04-01

Low density lipoproteins (LDLs) modulate the expression of key genes involved in atherogenesis. Recently, we have shown that the transcription factor neuron-derived orphan receptor-1 (NOR-1) is involved in vascular smooth muscle cell (VSMC) proliferation. Our aim was to analyze whether NOR-1 is involved in LDL-induced mitogenic effects in VSMC. LDL induced NOR-1 expression in a time- and dose-dependent manner. Antisense oligonucleotides against NOR-1 inhibit DNA synthesis induced by LDL in VSMCs as efficiently as antisense against the protooncogene c-fos. The upregulation of NOR-1 mRNA levels by LDL involves pertusis-sensitive G protein-coupled receptors, Ca2+ mobilization, protein kinases A (PKA) and C (PKC) activation, and mitogen-activated protein kinase pathways (MAPK) (p44/p42 and p38). LDL promotes cAMP response element binding protein (CREB) activation (phosphorylation in Ser133). In transfection assays a dominant-negative of CREB inhibits NOR-1 promoter activity, while mutation of specific (cAMP response element) CRE sites in the NOR-1 promoter abolishes LDL-induced NOR-1 promoter activity. In VSMCs, LDL-induced mitogenesis involves NOR-1 upregulation through a CREB-dependent mechanism. CREB could play a role in the modulation by LDL of key genes (containing CRE sites) involved in atherogenesis.

BDNF–ERK–CREB signalling mediates the role of miR-132 in the regulation of the effects of oleanolic acid in male mice

PubMed Central

Yi, Li-Tao; Li, Jing; Liu, Bin-Bin; Luo, Liu; Liu, Qing; Geng, Di

2014-01-01

Background Although previous study has demonstrated that brain-derived neurotrophic factor (BDNF) is involved in the antidepressant-like effect of oleanolic acid, there is little information regarding the details of the molecular mechanism involved in this effect. Methods We used a chronic unpredictable mild stress (CUMS) model to test the antidepressant-like effect of oleanolic acid on depressant-like behaviour, miR-132 expression and synaptic protein expression in the male mouse hippocampus. Furthermore, we explored the possible signalling pathways associated with miR-132 expression that mediate the effect of oleanolic acid on neuronal proliferation. Results The results demonstrated that a 3-week treatment with oleanolic acid ameliorated CUMS-induced anhedonic and anxiogenic behaviours. Furthermore, we found that oleanolic acid led to the BDNF-related phosphorylation and activation of extracellular signal-regulated kinases (ERK) and cyclic adenosine monophosphate response element binding protein (CREB), which was associated with the upregulation of miR-132 and hippocampal neuronal proliferation. Moreover, experiments with an miR-132 antagomir revealed that targeting miR-132 led to inhibition of neuronal proliferation and the postsynaptic density protein 95, but did not affect presynaptic protein synapsin I. Limitations Several other stimuli can also induce CREB phosphorylation in the hippocampus. Thus, regulation of miR-132 may not be restricted to neurotrophic signalling. Conclusion Our results show that oleanolic acid induces the upregulation of miR-132, which serves as an important regulator of neurotrophic actions, mainly through the activation of the hippocampal BDNF–ERK–CREB signalling pathways. PMID:25079084

Low doses of bisphenol A promote human seminoma cell proliferation by activating PKA and PKG via a membrane G-protein-coupled estrogen receptor.

PubMed

Bouskine, Adil; Nebout, Marielle; Brücker-Davis, Françoise; Benahmed, Mohamed; Fenichel, Patrick

2009-07-01

Fetal exposure to environmental estrogens may contribute to hypofertility and/or to testicular germ cell cancer. However, many of these xenoestrogens have only a weak affinity for the classical estrogen receptors (ERs,) which is 1,000-fold less potent than the affinity of 17beta-estradiol (E(2)). Thus, several mechanisms have been suggested to explain how they could affect male germ cell proliferation at low environmental relevant concentrations. In this study we aimed to explore the possible promoting effect of bisphenol A (BPA) on human testicular seminoma cells. BPA is a well-recognized estrogenic endocrine disruptor used as a monomer to manufacture poly carbonate plastic and released from resin-lined food or beverage cans or from dental sealants. BPA at very low concentrations (10(-9) to 10(-12) M) similar to those found in human fluids stimulated JKT-1 cell proliferation in vitro. BPA activated both cAMP-dependent protein kinase and cGMP-dependent protein kinase pathways and triggered a rapid (15 min) phosphorylation of the transcription factor cAMP response-element-binding protein (CREB) and the cell cycle regulator retinoblastoma protein (Rb). This nongenomic activation did not involve classical ERs because it could not be reversed by ICI 182780 (an ER antagonist) or reproduced either by E(2) or by diethylstilbestrol (a potent synthetic estrogen), which instead triggered a suppressive effect. This activation was reproduced only by E(2) coupled to bovine serum albumin (BSA), which is unable to enter the cell. As with E(2)-BSA, BPA promoted JKT-1 cell proliferation through a G-protein-coupled nonclassical membrane ER (GPCR) involving a Galpha(s) and a Galpha(i)/Galpha(q) subunit, as shown by the reversible effect observed by the corresponding inhibitors NF449 and pertussis toxin. This GPCR-mediated nongenomic action represents--in addition to the classical ER-mediated effect--a new basis for evaluating xenoestrogens such as BPA that, at low doses and with a high affinity for this GPCR, could interfere with the developmental programming of fetal germ cell proliferation and/or differentiation when they cross the placenta.

Selenium in bone health: roles in antioxidant protection and cell proliferation.

PubMed

Zeng, Huawei; Cao, Jay J; Combs, Gerald F

2013-01-10

Selenium (Se) is an essential trace element for humans and animals, and several findings suggest that dietary Se intake may be necessary for bone health. Such findings may relate to roles of Se in antioxidant protection, enhanced immune surveillance and modulation of cell proliferation. Elucidation of the mechanisms by which Se supports these cellular processes can lead to a better understanding of the role of this nutrient in normal bone metabolism. This article reviews the current knowledge concerning the molecular functions of Se relevant to bone health.

Selenium in Bone Health: Roles in Antioxidant Protection and Cell Proliferation

PubMed Central

Zeng, Huawei; Cao, Jay J.; Combs, Gerald F.

2013-01-01

Selenium (Se) is an essential trace element for humans and animals, and several findings suggest that dietary Se intake may be necessary for bone health. Such findings may relate to roles of Se in antioxidant protection, enhanced immune surveillance and modulation of cell proliferation. Elucidation of the mechanisms by which Se supports these cellular processes can lead to a better understanding of the role of this nutrient in normal bone metabolism. This article reviews the current knowledge concerning the molecular functions of Se relevant to bone health. PMID:23306191

l-Arginine modulates neonatal lymphocyte proliferation through an interleukin-2 independent pathway

PubMed Central

Yu, Hong-Ren; Kuo, Ho-Chang; Huang, Li-Tung; Chen, Chih-Cheng; Tain, You-Lin; Sheen, Jiunn-Ming; Tiao, Mao-Meng; Huang, Hsin-Chun; Yang, Kuender D; Ou, Chia-Yo; Hsu, Te-Yao

2014-01-01

In cases of arginine depletion, lymphocyte proliferation, cytokine production and CD3ζ chain expression are all diminished. In addition to myeloid suppressor cells, polymorphonuclear cells (PMN) also exert T-cell immune suppressive effects through arginase-induced l-arginine depletion, especially during pregnancy. In this study, we investigated how arginase/l-arginine modulates neonatal lymphocyte proliferation. Results showed that the neonatal plasma l-arginine level was lower than in adults (48·1 ± 11·3 versus 86·5 ± 14·6 μm; P = 0·003). Neonatal PMN had a greater abundance of arginase I protein than adult PMN. Both transcriptional regulation and post-transcriptional regulation were responsible for the higher arginase I expression of neonatal PMN. Exogenous l-arginine enhanced neonate lymphocyte proliferation but not that of adult cells. The RNA-binding protein HuR was important but was not the only modulation factor in l-arginine-regulated neonatal T-cell proliferation. l-Arginine-mediated neonatal lymphocyte proliferation could not be blocked by interleukin-2 receptor blocking antibodies. These results suggest that the altered arginase/l-arginine cascade may be one of the mechanisms that contribute to altered neonatal immune responses. Exogenous l-arginine could enhance neonate lymphocyte proliferation through an interleukin-2-independent pathway. PMID:24697328

G protein-coupled receptor 30 (GPR30) mediates gene expression changes and growth response to 17beta-estradiol and selective GPR30 ligand G-1 in ovarian cancer cells.

PubMed

Albanito, Lidia; Madeo, Antonio; Lappano, Rosamaria; Vivacqua, Adele; Rago, Vittoria; Carpino, Amalia; Oprea, Tudor I; Prossnitz, Eric R; Musti, Anna Maria; Andò, Sebastiano; Maggiolini, Marcello

2007-02-15

Estrogens play a crucial role in the development of ovarian tumors; however, the signal transduction pathways involved in hormone action are still poorly defined. The orphan G protein-coupled receptor 30 (GPR30) mediates the nongenomic signaling of 17beta-estradiol (E2) in a variety of estrogen-sensitive cancer cells through activation of the epidermal growth factor receptor (EGFR) pathway. Whether estrogen receptor alpha (ERalpha) also contributes to GPR30/EGFR signaling is less understood. Here, we show that, in ERalpha-positive BG-1 ovarian cancer cells, both E2 and the GPR30-selective ligand G-1 induced c-fos expression and estrogen-responsive element (ERE)-independent activity of a c-fos reporter gene, whereas only E2 stimulated an ERE-responsive reporter gene, indicating that GPR30 signaling does not activate ERalpha-mediated transcription. Similarly, both ligands up-regulated cyclin D1, cyclin E, and cyclin A, whereas only E2 enhanced progesterone receptor expression. Moreover, both GPR30 and ERalpha expression are required for c-fos stimulation and extracellular signal-regulated kinase (ERK) activation in response to either E2 or G-1. Inhibition of the EGFR transduction pathway inhibited c-fos stimulation and ERK activation by either ligand, suggesting that in ovarian cancer cells GPR30/EGFR signaling relays on ERalpha expression. Interestingly, we show that both GPR30 and ERalpha expression along with active EGFR signaling are required for E2-stimulated and G-1-stimulated proliferation of ovarian cancer cells. Because G-1 was able to induce both c-fos expression and proliferation in the ERalpha-negative/GPR30-positive SKBR3 breast cancer cells, the requirement for ERalpha expression in GPR30/EGFR signaling may depend on the specific cellular context of different tumor types.

Fundamental Study of the Development and Evaluation of Biodegradable Mg-Y-Ca-Zr Alloys as Novel Implant Materials

NASA Astrophysics Data System (ADS)

Da-Tren Chou

Degradable metals hold considerable promise as materials which exhibit higher mechanical properties than degradable polymers while corroding over time to alleviate complications such as stress-shielding and infection that is inherent to permanent, bioinert metallic biomaterials. Specifically, degradable magnesium (Mg) alloys have emerged as a promising alternative for orthopedic and craniofacial applications due to their positive bone remodeling behavior, good biocompatibility, and relatively high strength compared to polymers while exhibiting similar stiffness to natural bone. Increasing the strength to maintain device integrity during degradation while simultaneously controlling the rapid corrosion of Mg to reduce the risk of hydrogen gas accumulation and toxicity are ongoing paramount goals for optimizing Mg alloys for musculoskeletal applications. In order to address these goals, novel Mg-Y-Ca-Zr based alloys were developed with alloying elements judiciously selected to impart favorable properties. Processing techniques including solution heat treatment combined with hot extrusion were employed to further enhance the desired properties of the material namely, controlled corrosion, high strength and ductility, and minimal toxic response. Increasing the Y content contributed to improved corrosion resistance yielding corrosion rates similar to commercial Mg alloys. Hot extrusion was employed to reduce the grain size, thereby improving mechanical properties through the Hall-Petch relation. Extrusion yielded extremely high strength relative to other Mg alloys, values approaching that of iron-based alloys, due to the presence of Mg12YZn, a long period stacking order phase that served to impede dislocation propagation. Both as-cast and extruded Mg-Y-Ca-Zr alloys demonstrated excellent in vitro cytocompatibility eliciting high viability and proliferation of MC3T3 pre-osteoblast cells and human mesenchymal stem cells. Alloying elements Y and Zr were specifically shown to improve cell proliferation. Finally, implantation of Mg-Y-Ca-Zr based alloys into the mouse subcutaneous tissue and intramedullary cavities of fractured rat femurs resulted in a normal host response and fracture healing, without eliciting any local or systemic toxicity. Thus, the alloys investigated in this work demonstrated great potential for applications as orthopedic and craniofacial implant biomaterials, warranting additional pre-clinical safety and efficacy trials that will be conducted in the near future.

Gemfibrozil, a Lipid-lowering Drug, Inhibits the Induction of Nitric-oxide Synthase in Human Astrocytes*

PubMed Central

Pahan, Kalipada; Jana, Malabendu; Liu, Xiaojuan; Taylor, Bradley S.; Wood, Charles; Fischer, Susan M.

2007-01-01

Gemfibrozil, a lipid-lowering drug, inhibited cytokine-induced production of NO and the expression of inducible nitric-oxide synthase (iNOS) in human U373MG astroglial cells and primary astrocytes. Similar to gemfibrozil, clofibrate, another fibrate drug, also inhibited the expression of iNOS. Inhibition of human iNOS promoter-driven luciferase activity by gemfibrozil in cytokine-stimulated U373MG astroglial cells suggests that this compound inhibits the transcription of iNOS. Since gemfibrozil is known to activate peroxisome proliferator-activated receptor-α (PPAR-α), we investigated the role of PPAR-α in gemfibrozil-mediated inhibition of iNOS. Gemfibrozil induced peroxisome proliferator-responsive element (PPRE)-dependent luciferase activity, which was inhibited by the expression of ΔhPPAR-α, the dominant-negative mutant of human PPAR-α. However, ΔhPPAR-α was unable to abrogate gemfibrozil-mediated inhibition of iNOS suggesting that gemfibrozil inhibits iNOS independent of PPAR-α. The human iNOS promoter contains consensus sequences for the binding of transcription factors, including interferon-γ (IFN-γ) regulatory factor-1 (IRF-1) binding to interferon-stimulated responsive element (ISRE), signal transducer and activator of transcription (STAT) binding to γ-activation site (GAS), nuclear factor-κB (NF-κB), activator protein-1 (AP-1), and CCAAT/enhancer-binding protein β (C/EBPβ); therefore, we investigated the effect of gemfibrozil on the activation of these transcription factors. The combination of interleukin (IL)-1β and IFN-γ induced the activation of NF-κB, AP-1, C/EBPβ, and GAS but not that of ISRE, suggesting that IRF-1 may not be involved in cytokine-induced expression of iNOS in human astrocytes. Interestingly, gemfibrozil strongly inhibited the activation of NF-κB, AP-1, and C/EBPβ but not that of GAS in cytokine-stimulated astroglial cells. These results suggest that gemfibrozil inhibits the induction of iNOS probably by inhibiting the activation of NF-κB, AP-1, and C/EBPβ and that gemfibrozil, a prescribed drug for humans, may further find its therapeutic use in neuroinflammatory diseases. PMID:12244038

Overexpression of caspase 7 is ERα dependent to affect proliferation and cell growth in breast cancer cells by targeting p21(Cip).

PubMed

Chaudhary, S; Madhukrishna, B; Adhya, A K; Keshari, S; Mishra, S K

2016-04-18

Caspase 7 (CASP7) expression has important function during cell cycle progression and cell growth in certain cancer cells and is also involved in the development and differentiation of dental tissues. However, the function of CASP7 in breast cancer cells is unclear. The aim of this study was to analyze the expression of CASP7 in breast carcinoma patients and determine the role of CASP7 in regulating tumorigenicity in breast cancer cells. In this study, we show that the CASP7 expression is high in breast carcinoma tissues compared with normal counterpart. The ectopic expression of CASP7 is significantly associated with ERα expression status and persistently elevated in different stages of the breast tumor grades. High level of CASP7 expression showed better prognosis in breast cancer patients with systemic endocrine therapy as observed from Kaplan-Meier analysis. S3 and S4, estrogen responsive element (ERE) in the CASP7 promoter, is important for estrogen-ERα-mediated CASP7 overexpression. Increased recruitment of p300, acetylated H3 and pol II in the ERE region of CASP7 promoter is observed after hormone stimulation. Ectopic expression of CASP7 in breast cancer cells results in cell growth and proliferation inhibition via p21(Cip) reduction, whereas small interfering RNA (siRNA) mediated reduction of CASP7 rescued p21(Cip) levels. We also show that pro- and active forms of CASP7 is located in the nucleus apart from cytoplasmic region of breast cancer cells. The proliferation and growth of breast cancer cells is significantly reduced by broad-spectrum peptide inhibitors and siRNA of CASP7. Taken together, our findings show that CASP7 is aberrantly expressed in breast cancer and contributes to cell growth and proliferation by downregulating p21(Cip) protein, suggesting that targeting CASP7-positive breast cancer could be one of the potential therapeutic strategies.

Opposing effects of TIGAR- and RAC1-derived ROS on Wnt-driven proliferation in the mouse intestine

PubMed Central

Cheung, Eric C.; Lee, Pearl; Ceteci, Fatih; Nixon, Colin; Blyth, Karen; Sansom, Owen J.; Vousden, Karen H.

2016-01-01

Reactive oxygen species (ROS) participate in numerous cell responses, including proliferation, DNA damage, and cell death. Based on these disparate activities, both promotion and inhibition of ROS have been proposed for cancer therapy. However, how the ROS response is determined is not clear. We examined the activities of ROS in a model of Apc deletion, where loss of the Wnt target gene Myc both rescues APC loss and prevents ROS accumulation. Following APC loss, Myc has been shown to up-regulate RAC1 to promote proliferative ROS through NADPH oxidase (NOX). However, APC loss also increased the expression of TIGAR, which functions to limit ROS. To explore this paradox, we used three-dimensional (3D) cultures and in vivo models to show that deletion of TIGAR increased ROS damage and inhibited proliferation. These responses were suppressed by limiting damaging ROS but enhanced by lowering proproliferative NOX-derived ROS. Despite having opposing effects on ROS levels, loss of TIGAR and RAC1 cooperated to suppress intestinal proliferation following APC loss. Our results indicate that the pro- and anti-proliferative effects of ROS can be independently modulated in the same cell, with two key targets in the Wnt pathway functioning to integrate the different ROS signals for optimal cell proliferation. PMID:26679840

miR-133b Regulation of Connective Tissue Growth Factor

PubMed Central

Gjymishka, Altin; Pi, Liya; Oh, Seh-Hoon; Jorgensen, Marda; Liu, Chen; Protopapadakis, Yianni; Patel, Ashnee; Petersen, Bryon E.

2017-01-01

miRNAs are involved in liver regeneration, and their expression is dysregulated in hepatocellular carcinoma (HCC). Connective tissue growth factor (CTGF), a direct target of miR-133b, is crucial in the ductular reaction (DR)/oval cell (OC) response for generating new hepatocyte lineages during liver injury in the context of hepatotoxin-inhibited hepatocyte proliferation. Herein, we investigate whether miR-133b regulation of CTGF influences HCC cell proliferation and migration, and DR/OC response. We analyzed miR-133b expression and found it to be down-regulated in HCC patient samples and induced in the rat DR/OC activation model of 2-acetylaminofluorene with partial hepatectomy. Furthermore, overexpression of miR-133b via adenoviral system in vitro led to decreased CTGF expression and reduced proliferation and Transwell migration of both HepG2 HCC cells and WBF-344 rat OCs. In vivo, overexpression of miR-133b in DR/OC activation models of 2-acetylaminofluorene with partial hepatectomy in rats, and 3,5-diethoxycarbonyl-1,4-dihydrocollidine in mice, led to down-regulation of CTGF expression and OC proliferation. Collectively, these results show that miR-133b regulation of CTGF is a novel mechanism critical for the proliferation and migration of HCC cells and OC response. PMID:26945106

Roles of Stat3 and ERK in G-CSF signaling.

PubMed

Kamezaki, Kenjirou; Shimoda, Kazuya; Numata, Akihiko; Haro, Takashi; Kakumitsu, Haruko; Yoshie, Masumi; Yamamoto, Masahiro; Takeda, Kiyoshi; Matsuda, Tadashi; Akira, Shizuo; Ogawa, Katsuhiro; Harada, Mine

2005-02-01

G-CSF specifically stimulates the proliferation and differentiation of cells that are committed to the neutrophil-granulocyte lineage. Although Stat3 was thought to be essential for the transduction of G-CSF-induced cell proliferation and differentiation signals, mice deficient for Stat3 in hematopoietic cells show neutrocytosis and infiltration of cells into the digestive tract. The number of progenitor cells in the neutrophil lineage is not changed, and G-CSF-induced proliferation of progenitor cells and prolonged neutrophil survival were observed in Stat3-deficient mice. In hematopoietic cells from Stat3-deficient mice, trace levels of SOCS3, a negative regulator of granulopoiesis, were observed, and SOCS3 expression was not induced by G-CSF stimulation. Stat3-null bone marrow cells displayed a significant activation of extra-cellular regulated kinase 1 (ERK1)/ERK2 under basal conditions, and the activation of ERK was enhanced and sustained by G-CSF stimulation. Furthermore, the augmented proliferation of Stat3-deficient bone marrow cells in response to G-CSF was dramatically decreased by addition of a MEK1 inhibitor. These results indicate that Stat3 functions as a negative regulator of G-CSF signaling by inducing SOCS3 expression and that ERK activation is the major factor responsible for inducing the proliferation of hematopoietic cells in response to G-CSF.

Human T cell lymphotropic virus type I genomic expression and impact on intracellular signaling pathways during neurodegenerative disease and leukemia.

PubMed

Yao, J; Wigdahl, B

2000-01-01

HTLV-I has been identified as the etiologic agent of neoplasia within the human peripheral blood T lymphocyte population, and a progressive neurologic disorder based primarily within the central nervous system. We have examined the role of HTLV-I in these two distinctly different clinical syndromes by examining the life cycle of the virus, with emphasis on the regulation of viral gene expression within relevant target cell populations. In particular, we have examined the impact of specific viral gene products, particularly Tax, on cellular metabolic function. Tax is a highly promiscuous and pleiotropic viral oncoprotein, and is the most important factor contributing to the initial stages of viral-mediated transformation of T cells after HTLV-I infection. Tax, which weakly binds to Tax response element 1 (TRE-1) in the viral long terminal repeat (LTR), can dramatically trans-activate viral gene expression by interacting with cellular transcription factors, such as activated transcription factors and cyclic AMP response element binding proteins (ATF/CREB), CREB binding protein (CBP/p300), and factors involved with the basic transcription apparatus. At the same time, Tax alters cellular gene expression by directly or indirectly interacting with a variety of cellular transcription factors, cell cycle control elements, and cellular signal transduction molecules ultimately resulting in dysregulated cell proliferation. The mechanisms associated with HTLV-I infection, leading to tropical spastic paraparesis (TSP) are not as clearly resolved. Possible explanations of viral-induced neurologic disease range from central nervous system (CNS) damage caused by direct viral invasion of the CNS to bystander CNS damage caused by the immune response to HTLV-I infection. It is interesting to note that it is very rare for an HTLV-I infected individual to develop both adult T cell leukemia (ATL) and TSP in his/her life time, suggesting that the mechanisms governing development of these two diseases are mutually exclusive.

Butyl benzyl phthalate suppresses the ATP-induced cell proliferation in human osteosarcoma HOS cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, P.-S., E-mail: pslediting@mail.scu.edu.t; Chen, C.-Y.

2010-05-01

Butyl benzyl phthalate (BBP), an endocrine disruptor present in the environment, exerts its genomic effects via intracellular steroid receptors and elicits non-genomic effects by interfering with membrane ion-channel receptors. We previously found that BBP blocks the calcium signaling coupled with P2X receptors in PC12 cells (Liu and Chen, 2006). Osteoblast P2X receptors were recently reported to play a role in cell proliferation and bone remodeling. In this present study, the effects of BBP on ATP-induced responses were investigated in human osteosarcoma HOS cells. These receptors mRNA had been detected, named P2X4, P2X7, P2Y2, P2Y4, P2Y5, P2Y9, and P2Y11, in humanmore » osteosarcoma HOS cells by RT-PCR. The enhancement of cell proliferation and the decrease of cytoviability had both been shown to be coupled to stimulation via different concentrations of ATP. BBP suppressed the ATP-induced calcium influx (mainly coupled with P2X) and cell proliferation but not the ATP-induced intracellular calcium release (mainly coupled with P2Y) and cytotoxicity in human osteosarcoma HOS cells. Suramin, a common P2 receptor's antagonist, blocked the ATP-induced calcium signaling, cell proliferation, and cytotoxicity. We suggest that P2X is mainly responsible for cell proliferation, and P2Y might be partially responsible for the observed cytotoxicity. BBP suppressed the calcium signaling coupled with P2X, suppressing cell proliferation. Since the importance of P2X receptors during bone metastasis has recently become apparent, the possible toxic risk of environmental BBP during bone remodeling is a public problem of concern.« less

Effect of Interlukin-1β on proliferation of gastric epithelial cells in culture

PubMed Central

Beales, Ian LP

2002-01-01

Background Helicobacter pylori is the main risk factor for the development of non-cardia gastric cancer. Increased proliferation of the gastric mucosa is a feature of H. pylori infection. Mucosal interkeukin-1β production is increased in H. pylori infection and IL-1β genotypes associated with increased pro-inflammatory activity are risk factors for the development of gastric cancer. The effect of IL-1β on gastric epithelial cell proliferation has been examined in this study. Methods AGS cells were cultured with IL-1β. DNA synthesis was assed by [3H]thymidine incorporation and total viable cell numbers by MTT assay. Results IL-1β dose dependently increased DNA synthesis and cell numbers. The enhanced proliferation was blocked by interleukin-1 receptor antagonist. Addition of neutralising antibody to GM-CSF reduced IL-1β-stimulated proliferation by 31 ± 4 %. GM-CSF alone significantly stimulated proliferation. Addition or neutralisation of IL-8 had no effect on basal or IL-1β-stimulated proliferation. The tyrosine kinase inhibitor genistein completely blocked IL-1β-stimulated proliferation and inhibition of the extracellular signal related kinase pathway with PD 98059 inhibited IL-1β stimulated proliferation by 58 ± 5 %. Conclusions IL-1β stimulates proliferation in gastric epithelial cells. Autocrine stimulation by GM-CSF contributes to this proliferative response. Signalling via tyrosine kinase activity is essential to the mitogenic response to IL-1β. The extracellular signal related kinase pathway is involved in, but not essential to downstream signalling. IL-1β may contribute to the hyperproliferation seen in H. pylori- infected gastric mucosa, and be involved in the carcinogenic process. PMID:11936957

Slow and sustained nitric oxide releasing compounds inhibit multipotent vascular stem cell proliferation and differentiation without causing cell death.

PubMed

Curtis, Brandon M; Leix, Kyle Alexander; Ji, Yajing; Glaves, Richard Samuel Elliot; Ash, David E; Mohanty, Dillip K

2014-07-18

Atherosclerosis is the leading cause of cerebral and myocardial infarction. It is believed that neointimal growth common in the later stages of atherosclerosis is a result of vascular smooth muscle cell (SMC) de-differentiation in response to endothelial injury. However, the claims of the SMC de-differentiation theory have not been substantiated by monitoring the fate of mature SMCs in response to such injuries. A recent study suggests that atherosclerosis is a consequence of multipotent vascular stem cell (MVSC) differentiation. Nitric oxide (NO) is a well-known mediator against atherosclerosis, in part because of its inhibitory effect on SMC proliferation. Using three different NO-donors, we have investigated the effects of NO on MVSC proliferation. Results indicate that NO inhibits MVSC proliferation in a concentration dependent manner. A slow and sustained delivery of NO proved to inhibit proliferation without causing cell death. On the other hand, larger, single-burst NO concentrations, inhibits proliferation, with concurrent significant cell death. Furthermore, our results indicate that endogenously produced NO inhibits MVSC differentiation to mesenchymal-like stem cells (MSCs) and subsequently to SMC as well. Published by Elsevier Inc.

Potential advantages of treatment of transplanted saphenous vein aorto-coronary artery bypass grafts with beta irradiation to prevent graft occlusion.

PubMed

Smith, R G

1997-01-01

Intimal proliferation or Neointimal hyperplasia (NIH) is a vascular lesion that often arises in arteries after balloon angioplasty or other vessel wall injuries. FIH is a vascular lesion that develops in autologous saphenous vein grafts (SVG) after transplantation into the aorto-coronary circulation or the peripheral vascular circulation. FIH shares elements of smooth muscle migration, proliferation and fibrous tissue deposition in common with nibrointimal proliferation (NIH). Either NIH of a coronary artery or FIH of a SVG obstruct the vascular lumen and result in myocardial dysfunction. Local radiotherapy has been used for several decades to reduce the post-operative recurrence of the fibrovascular proliferations of pterygia and keloids. Similarly, in animal and human experiments, endovascular radiotherapy has been shown to reduce arterial smooth muscle proliferation. Consideration of the similarities of vascular smooth muscle cell proliferation in NIH and FIH leads one to suggest that endovascular beta irradiation can reduce FIH as well as it reduces NIH. The goal of such treatment is to achieve a clinically significant decrease in the morbidity and mortality resulting from SVG occlusions. The potential for large reduction of the consequences of SVG occlusion, the very large number of patients at risk, and the simplicity of the proposed intervention encourages prompt scientific evaluation of this technique.

Chemical characteristics and anti-proliferation activities of Ganoderma tsugae polysaccharides.

PubMed

Chien, Rao-Chi; Yen, Ming-Tsung; Tseng, Yu-Hsiu; Mau, Jeng-Leun

2015-09-05

Polysaccharides were extracted by hot-water and hot-alkali from four forms of Ganoderma tsugae including mature and baby Ling chih, mycelium and filtrate. Different profiles of proximate composition and monosaccharide constituents, and element contents were found in the extracted polysaccharides from different extractions and different forms. The molecular weight distributions of polysaccharides were 2.8×10(4)-6.5×10(5)Da and their infrared spectra were comparable. The hot-alkali extracted polysaccharides exhibited better anti-proliferation on IMR32 cells than the hot-water extracted polysaccharides, which were in turn more effective than the hot-water extracts. Besides, most hot-water extracts and both extracted polysaccharides exhibited an anti-proliferation effect on Hep G2 cells. However, the hot-water extracts showed less effective in anti-proliferation of IMR32 and Hep G2 cells. Based on the anti-tumor effects, both polysaccharides could be prepared for use in the formulation of nutraceuticals and functional foods. Copyright © 2015 Elsevier Ltd. All rights reserved.

Separation of human bone marrow by counterflow centrifugation monitored by DNA-flowcytometry.

PubMed

de Witte, T; Plas, A; Koekman, E; Blankenborg, G; Salden, M; Wessels, J; Haanen, C

1984-10-01

Human bone marrow was fractionated by counterflow centrifugation into 16 fractions with increasing cell size. Three distinct subpopulations could be recognized: small lymphocytic cells, medium-sized nucleated erythroid cells and large myeloid elements. DNA-flowcytometry and 3H-thymidine uptake showed that within the erythroid and myeloid cell populations counterflow centrifugation separates each population according to the cell cycle phase. Hypotonic treatment of bone marrow for removal of the erythroid nucleated cells resulted in a complete abrogation of the proliferating erythroid cell population. Counterflow centrifugation also separates the small non-proliferating myeloid and erythroid committed stem cells from the larger proliferating stem cells. It appeared feasible to separate the small lymphocytic cells from the majority of BFU-E and CFU-GM, due to the larger size of the proliferating normoblasts and the committed progenitor cells. Elimination of the mature lymphocytes from the haematopoietic stem cells by counterflow centrifugation may offer an alternative approach to the prevention of graft versus host disease (GvHD).

Sepsis reveals compartment-specific responses in intestinal proliferation and apoptosis in transgenic mice whose enterocytes re-enter the cell cycle.

PubMed

Lyons, John D; Klingensmith, Nathan J; Otani, Shunsuke; Mittal, Rohit; Liang, Zhe; Ford, Mandy L; Coopersmith, Craig M

2017-12-01

Cell production and death are tightly regulated in the rapidly renewing gut epithelium, with proliferation confined to crypts and apoptosis occurring in villi and crypts. This study sought to determine how stress alters these compartmentalized processes. Wild-type mice made septic via cecal ligation and puncture had decreased crypt proliferation and increased crypt and villus apoptosis. Fabpi -TAg mice expressing large T-antigen solely in villi had ectopic enterocyte proliferation with increased villus apoptosis in unmanipulated animals. Septic fabpi -TAg mice had an unexpected increase in villus proliferation compared with unmanipulated littermates, whereas crypt proliferation was decreased. Cell cycle regulators cyclin D1 and cyclin D2 were decreased in jejunal tissue in septic transgenic mice. In contrast, villus and crypt apoptosis were increased in septic fabpi -TAg mice. To examine the relationship between apoptosis and proliferation in a compartment-specific manner, fabpi -TAg mice were crossed with fabpl -Bcl-2 mice, resulting in expression of both genes in the villus but Bcl-2 alone in the crypt. Septic bi-transgenic animals had decreased crypt apoptosis but had a paradoxical increase in villus apoptosis compared with septic fabpi -TAg mice, associated with decreased proliferation in both compartments. Thus, sepsis unmasks compartment-specific proliferative and apoptotic regulation that is not present under homeostatic conditions.-Lyons, J. D., Klingensmith, N. J., Otani, S., Mittal, R., Liang, Z., Ford, M. L., Coopersmith, C. M. Sepsis reveals compartment-specific responses in intestinal proliferation and apoptosis in transgenic mice whose enterocytes re-enter the cell cycle. © FASEB.

Role of cellular bioenergetics in smooth muscle cell proliferation induced by platelet-derived growth factor.

PubMed

Perez, Jessica; Hill, Bradford G; Benavides, Gloria A; Dranka, Brian P; Darley-Usmar, Victor M

2010-05-13

Abnormal smooth muscle cell proliferation is a hallmark of vascular disease. Although growth factors are known to contribute to cell hyperplasia, the changes in metabolism associated with this response, particularly mitochondrial respiration, remain unclear. Given the increased energy requirements for proliferation, we hypothesized that PDGF (platelet-derived growth factor) would stimulate glycolysis and mitochondrial respiration and that this elevated bioenergetic capacity is required for smooth muscle cell hyperplasia. To test this hypothesis, cell proliferation, glycolytic flux and mitochondrial oxygen consumption were measured after treatment of primary rat aortic VSMCs (vascular smooth muscle cells) with PDGF. PDGF increased basal and maximal rates of glycolytic flux and mitochondrial oxygen consumption; enhancement of these bioenergetic pathways led to a substantial increase in the mitochondrial reserve capacity. Interventions with the PI3K (phosphoinositide 3-kinase) inhibitor LY-294002 or the glycolysis inhibitor 2-deoxy-D-glucose abrogated PDGF-stimulated proliferation and prevented augmentation of glycolysis and mitochondrial reserve capacity. Similarly, when L-glucose was substituted for D-glucose, PDGF-dependent proliferation was abolished, as were changes in glycolysis and mitochondrial respiration. Interestingly, LDH (lactate dehydrogenase) protein levels and activity were significantly increased after PDGF treatment. Moreover, substitution of L-lactate for D-glucose was sufficient to increase mitochondrial reserve capacity and cell proliferation after treatment with PDGF; these effects were inhibited by the LDH inhibitor oxamate. These results suggest that glycolysis, by providing substrates that enhance the mitochondrial reserve capacity, plays an essential role in PDGF-induced cell proliferation, underscoring the integrated metabolic response required for proliferation of VSMCs in the diseased vasculature.

Checkpoint suppressor 1 suppresses transcriptional activity of ERα and breast cancer cell proliferation via deacetylase SIRT1.

PubMed

Xu, Zhaowei; Yang, Yangyang; Li, Bowen; Li, Yanan; Xia, Kangkai; Yang, Yuxi; Li, Xiahui; Wang, Miao; Li, Shujing; Wu, Huijian

2018-05-11

Breast cancer is a highly heterogeneous carcinoma in women worldwide, but the underlying mechanisms that account for breast cancer initiation and development have not been fully established. Mounting evidence indicates that Checkpoint suppressor 1 (CHES1) is tightly associated with tumorigenesis and prognosis in many types of cancer. However, the definitive function of CHES1 in breast cancer remains to be explored. Here we showed that CHES1 had a physical interaction with estrogen receptor-α (ERα) and repressed the transactivation of ERα in breast cancer cells. Mechanistically, the interaction between CHES1 and ERα enhanced the recruitment of nicotinamide adenine dinucleotide (NAD+) deacetylase Sirtuin 1 (SIRT1), and it further induced SIRT1-mediated ERα deacetylation and repression on the promoter-binding enrichment of ERα. In addition, we also found that the expression of CHES1 was repressed by estrogen-ERα signaling and the expression level of CHES1 was significantly downregulated in ERα-positive breast cancer. The detailed mechanism was that ERα may directly bind to CHES1 potential promoter via recognizing the conserved estrogen response element (ERE) motif in response to estrogen stimulation. Functionally, CHES1 inhibited ERα-mediated proliferation and tumorigenesis of breast cancer cells in vivo and in vitro. Totally, these results identified a negative cross-regulatory loop between ERα and CHES1 that was required for growth of breast cancer cells, it might uncover novel insight into molecular mechanism of CHES1 involved in breast cancer and provide new avenues for molecular-targeted therapy in hormone-regulated breast cancer.

17beta-estradiol, genistein, and 4-hydroxytamoxifen induce the proliferation of thyroid cancer cells through the g protein-coupled receptor GPR30.

PubMed

Vivacqua, Adele; Bonofiglio, Daniela; Albanito, Lidia; Madeo, Antonio; Rago, Vittoria; Carpino, Amalia; Musti, Anna Maria; Picard, Didier; Andò, Sebastiano; Maggiolini, Marcello

2006-10-01

The higher incidence of thyroid carcinoma (TC) in women during reproductive years compared with men and the increased risk associated with the therapeutic use of estrogens have suggested a pathogenetic role exerted by these steroids in the development of TC. In the present study, we evaluated the potential of 17beta-estradiol (E2), genistein (G), and 4-hydroxyta-moxifen (OHT) to regulate the expression of diverse estrogen target genes and the proliferation of human WRO, FRO, and ARO thyroid carcinoma cells, which were used as a model system. We have ascertained that ARO cells are devoid of estrogen receptors (ERs), whereas both WRO and FRO cells express a single variant of ERalpha that was neither transactivated, modulated, nor translocated into the nucleus upon treatment with ligands. However, E2, G, and OHT were able either to induce the transcriptional activity of c-fos promoter constructs, including those lacking the estrogen-responsive elements, or to increase c-fos, cyclin A, and D1 expression. It is noteworthy that we have demonstrated that the G protein-coupled receptor 30 (GPR30) and the mitogen-activated protein kinase (MAPK) pathway mediate both the up-regulation of c-fos and the growth response to E2, G, and OHT in TC cells studied, because these stimulatory effects were prevented by silencing GPR30 and using the MEK inhibitor 2'-amino-3'-methoxyflavone (PD 98059). Our findings provide new insight into the molecular mechanisms through which estrogens may induce the progression of TC.

Up-regulation of Hsp27 by ERα/Sp1 facilitates proliferation and confers resistance to apoptosis in human papillary thyroid cancer cells.

PubMed

Mo, Xiao-Mei; Li, Li; Zhu, Ping; Dai, Yu-Jie; Zhao, Ting-Ting; Liao, Ling-Yao; Chen, George G; Liu, Zhi-Min

2016-08-15

17β-estradiol (E2) has been suggested to play a role in the development and progression of papillary thyroid cancer. Heat shock protein 27 (Hsp27) is a member of the Hsp family that is responsible for cell survival under stressful conditions. Previous studies have shown that the 5'-promoter region of Hsp27 gene contains a specificity protein-1 (Spl) and estrogen response element half-site (ERE-half), which contributes to Hsp27 induction by E2 in breast cancer cells. However, it is unclear whether Hsp27 can be up-regulated by E2 and which estrogen receptor (ER) isoform and tethered transcription factor are involved in this regulation in papillary thyroid cancer cells. In the present study, we demonstrated that Hsp27 can be effectively up-regulated by E2 at mRNA and protein levels in human K1 and BCPAP papillary thyroid cancer cells which have more than two times higher level of ERα than that of ERβ. The up-regulation of Hsp27 by E2 is mediated by ERα/Sp1 and ERβ has repressive effect on this ERα/Sp1-mediated up-regulation of Hsp27. Moreover, we showed that the up-regulation of Hsp27 by ERα/Sp1 facilitates proliferation and confers resistance to apoptosis through interaction with procaspase-3. Targeting this pathway may be a potential strategy for therapy of papillary thyroid cancer. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Peroxisome Proliferator-Activated Receptor Subtype- and Cell-Type-Specific Activation of Genomic Target Genes upon Adenoviral Transgene Delivery

PubMed Central

Nielsen, Ronni; Grøntved, Lars; Stunnenberg, Hendrik G.; Mandrup, Susanne

2006-01-01

Investigations of the molecular events involved in activation of genomic target genes by peroxisome proliferator-activated receptors (PPARs) have been hampered by the inability to establish a clean on/off state of the receptor in living cells. Here we show that the combination of adenoviral delivery and chromatin immunoprecipitation (ChIP) is ideal for dissecting these mechanisms. Adenoviral delivery of PPARs leads to a rapid and synchronous expression of the PPAR subtypes, establishment of transcriptional active complexes at genomic loci, and immediate activation of even silent target genes. We demonstrate that PPARγ2 possesses considerable ligand-dependent as well as independent transactivation potential and that agonists increase the occupancy of PPARγ2/retinoid X receptor at PPAR response elements. Intriguingly, by direct comparison of the PPARs (α, γ, and β/δ), we show that the subtypes have very different abilities to gain access to target sites and that in general the genomic occupancy correlates with the ability to activate the corresponding target gene. In addition, the specificity and potency of activation by PPAR subtypes are highly dependent on the cell type. Thus, PPAR subtype-specific activation of genomic target genes involves an intricate interplay between the properties of the subtype- and cell-type-specific settings at the individual target loci. PMID:16847324

CRTC2 is required for β-cell function and proliferation.

PubMed

Eberhard, Chandra E; Fu, Accalia; Reeks, Courtney; Screaton, Robert A

2013-07-01

Previous work in insulinoma cell lines has established that calcineurin plays a critical role in the activation of cAMP-responsive element binding protein (Creb), a key transcription factor required for β-cell function and survival, by dephosphorylating the Creb coactivator Creb-regulated transcription coactivator (Crtc)2 at 2 regulatory sites, Ser171 and Ser275. Here, we report that Crtc2 is essential both for glucose-stimulated insulin secretion and cell survival in the β-cell. Endogenous Crtc2 activation is achieved via increasing glucose levels to the physiological feeding range, indicating that Crtc2 is a sensor that couples ambient glucose concentrations to Creb activity in the β-cell. Immunosuppressant drugs such as cyclosporin A and tacrolimus that target the protein phosphatase calcineurin are commonly administered after organ transplantation. Chronic use is associated with reduced insulin secretion and new onset diabetes, suggestive of pancreatic β-cell dysfunction. Importantly, we show that overexpression of a Crtc2 mutant rendered constitutively active by introduction of nonphosphorylatable alanine residues at Ser171 and Ser275 permits Creb target gene activation under conditions when calcineurin is inhibited. Taken together, these data suggest that promoting Crtc2-Creb activity is required for β-cell function and proliferation and promoting this pathway could ameliorate symptoms of new onset diabetes after transplantation.

MEIS1 functions as a potential AR negative regulator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cui, Liang; Department of Urology, Civil Aviation General Hospital/Civil Aviation Medical College of Peking University, Beijing 100123; Li, Mingyang

2014-10-15

The androgen receptor (AR) plays critical roles in human prostate carcinoma progression and transformation. However, the activation of AR is regulated by co-regulators. MEIS1 protein, the homeodomain transcription factor, exhibited a decreased level in poor-prognosis prostate tumors. In this study, we investigated a potential interaction between MEIS1 and AR. We found that overexpression of MEIS1 inhibited the AR transcriptional activity and reduced the expression of AR target gene. A potential protein–protein interaction between AR and MEIS1 was identified by the immunoprecipitation and GST pull-down assays. Furthermore, MEIS1 modulated AR cytoplasm/nucleus translocation and the recruitment to androgen response element in prostatemore » specific antigen (PSA) gene promoter sequences. In addition, MEIS1 promoted the recruitment of NCoR and SMRT in the presence of R1881. Finally, MEIS1 inhibited the proliferation and anchor-independent growth of LNCaP cells. Taken together, our data suggests that MEIS1 functions as a novel AR co-repressor. - Highlights: • A potential interaction was identified between MEIS1 and AR signaling. • Overexpression of MEIS1 reduced the expression of AR target gene. • MEIS1 modulated AR cytoplasm/nucleus translocation. • MEIS1 inhibited the proliferation and anchor-independent growth of LNCaP cells.« less

Epinephrine deficiency results in intact glucose counter-regulation, severe hepatic steatosis and possible defective autophagy in fasting mice

PubMed Central

Sharara-Chami, Rana I.; Zhou, Yingjiang; Ebert, Steven; Pacak, Karel; Ozcan, Umut; Majzoub, Joseph A.

2016-01-01

Epinephrine is one of the major hormones involved in glucose counter-regulation and gluconeogenesis. However, little is known about its importance in energy homeostasis during fasting. Our objective is to study the specific role of epinephrine in glucose and lipid metabolism during starvation. In our experiment, we subject regular mice and epinephrine-deficient mice to a 48-h fast then we evaluate the different metabolic responses to fasting. Our results show that epinephrine is not required for glucose counter-regulation: epinephrine-deficient mice maintain their blood glucose at normal fasting levels via glycogenolysis and gluconeogenesis, with normal fasting-induced changes in the peroxisomal activators: peroxisome proliferator activated receptor γ coactivator α (PGC-1α), fibroblast growth factor 21 (FGF-21), peroxisome proliferator activated receptor α (PPAR-α), and sterol regulatory element binding protein (SREBP-1c). However, fasted epinephrine-deficient mice develop severe ketosis and hepatic steatosis, with evidence for inhibition of hepatic autophagy, a process that normally provides essential energy via degradation of hepatic triglycerides during starvation. We conclude that, during fasting, epinephrine is not required for glucose homeostasis, lipolysis or ketogenesis. Epinephrine may have an essential role in lipid handling, possibly via an autophagy-dependent mechanism. PMID:22405854

PPARα activation sensitizes cancer cells to epigallocatechin-3-gallate (EGCG) treatment via suppressing heme oxygenase-1.

PubMed

Zhang, Shuyu; Yang, Xiaodong; Luo, Judong; Ge, Xin; Sun, Wanping; Zhu, Hong; Zhang, Weiping; Cao, Jianping; Hou, Yinglong

2014-01-01

Epigallocatechin-3-gallate (EGCG), the major polyphenolic constituent of green tea, is a potent antioxidant that may have potential therapeutic applications for the treatment of many disorders, including cancer. Peroxisome proliferator-activated receptor-α (PPARα) has been shown to play a key role in diverse metabolic and cellular functions. PPARα modulates target gene expression by binding to specific regions on the DNA of target genes. The effects and mechanisms of PPARα activation on EGCG efficacy have not yet been analyzed in cancer cells. We found that when cancer cells were exposed to EGCG, the expression of PPARα was increased at the protein level in a dose-dependent manner. The PPARα agonist clofibrate blocked cytoprotective heme oxygenase-1 (HO-1) induction and sensitized multiple types of cancer cells to EGCG-induced cell death. Conversely, the PPARα inhibitor G6471 and PPARα siRNA increased HO-1 expression. Electro-mobility shift assays (EMSA) and in vivo chromatin immunoprecipitation (ChIP) confirmed that PPARα interacts with the peroxisome proliferator-responsive element of the HO-1 promoter. Moreover, cell death induced by EGCG plus clofibrate was partially reversed by HO-1 overexpression in PANC1 cells. These results indicate that PPARα is a direct and negative regulator of HO-1 induced by EGCG and confers cell susceptibility to EGCG.

Alpha cyano-4-hydroxy-3-methoxycinnamic acid inhibits proliferation and induces apoptosis in human breast cancer cells.

PubMed

Hamdan, Lamia; Arrar, Zoheir; Al Muataz, Yacoub; Suleiman, Lutfi; Négrier, Claude; Mulengi, Joseph Kajima; Boukerche, Habib

2013-01-01

This study investigated the underlying mechanism of 4-hydroxy-3-methoxycinnamic acid (ACCA), on the growth of breast cancer cells and normal immortal epithelial cells, and compared their cytotoxic effects responses. Treatment of breast cancer cells (MCF-7, T47D, and MDA-231) with ACCA resulted in dose- and time-dependent decrease of cell proliferation, viability in colony formation assay, and programmed cell death (apoptosis) with minimal effects on non-tumoral cells. The ability of ACCA to suppress growth in cancer cells not expressing or containing defects in p53 gene indicates a lack of involvement of this critical tumor suppressor element in mediating ACCA-induced growth inhibition. Induction of apoptosis correlated with an increase in Bax protein, an established inducer of programmed cell death, and the ratio of Bax to Bcl-2, an established inhibitor of apoptosis. We also documented the ability of ACCA to inhibit the migration and invasion of MDA-231 cells with ACCA in vitro. Additionally, tumor growth of MDA-231 breast cancer cells in vivo was dramatically affected with ACCA. On the basis of its selective anticancer inhibitory activity on tumor cells, ACCA may represent a promising therapeutic drug that should be further evaluated as a chemotherapeutic agent for human breast cancer.

Alpha Cyano-4-Hydroxy-3-Methoxycinnamic Acid Inhibits Proliferation and Induces Apoptosis in Human Breast Cancer Cells

PubMed Central

Hamdan, Lamia; Arrar, Zoheir; Al Muataz, Yacoub; Suleiman, Lutfi; Négrier, Claude; Mulengi, Joseph Kajima; Boukerche, Habib

2013-01-01

This study investigated the underlying mechanism of 4-hydroxy-3-methoxycinnamic acid (ACCA), on the growth of breast cancer cells and normal immortal epithelial cells, and compared their cytotoxic effects responses. Treatment of breast cancer cells (MCF-7, T47D, and MDA-231) with ACCA resulted in dose- and time-dependent decrease of cell proliferation, viability in colony formation assay, and programmed cell death (apoptosis) with minimal effects on non-tumoral cells. The ability of ACCA to suppress growth in cancer cells not expressing or containing defects in p53 gene indicates a lack of involvement of this critical tumor suppressor element in mediating ACCA-induced growth inhibition. Induction of apoptosis correlated with an increase in Bax protein, an established inducer of programmed cell death, and the ratio of Bax to Bcl-2, an established inhibitor of apoptosis. We also documented the ability of ACCA to inhibit the migration and invasion of MDA-231 cells with ACCA in vitro. Additionally, tumor growth of MDA-231 breast cancer cells in vivo was dramatically affected with ACCA. On the basis of its selective anticancer inhibitory activity on tumor cells, ACCA may represent a promising therapeutic drug that should be further evaluated as a chemotherapeutic agent for human breast cancer. PMID:24039831

Insulin-like growth factor-I increases bone sialoprotein (BSP) expression through fibroblast growth factor-2 response element and homeodomain protein-binding site in the proximal promoter of the BSP gene.

PubMed

Nakayama, Youhei; Nakajima, Yu; Kato, Naoko; Takai, Hideki; Kim, Dong-Soon; Arai, Masato; Mezawa, Masaru; Araki, Shouta; Sodek, Jaro; Ogata, Yorimasa

2006-08-01

Insulin-like growth factor-I (IGF-I) promotes bone formation by stimulating proliferation and differentiation of osteoblasts. Bone sialoprotein (BSP), is thought to function in the initial mineralization of bone, is selectively expressed by differentiated osteoblast. To determine the molecular mechanism of IGF-I regulation of osteogenesis, we analyzed the effects of IGF-I on the expression of BSP in osteoblast-like Saos2 and in rat stromal bone marrow (RBMC-D8) cells. IGF-I (50 ng/ml) increased BSP mRNA levels at 12 h in Saos2 cells. In RBMC-D8 cells, IGF-I increased BSP mRNA levels at 3 h. From transient transfection assays, a twofold increase in transcription by IGF-I was observed at 12 h in pLUC3 construct that included the promoter sequence from -116 to +60. Effect of IGF-I was abrogated by 2-bp mutations in either the FGF2 response element (FRE) or homeodomain protein-binding site (HOX). Gel shift analyses showed that IGF-I increased binding of nuclear proteins to the FRE and HOX elements. Notably, the HOX-protein complex was supershifted by Smad1 antibody, while the FRE-protein complex was shifted by Smad1 and Cbfa1 antibodies. Dlx2 and Dlx5 antibodies disrupted the formation of the FRE- and HOX-protein complexes. The IGF-I effects on the formation of FRE-protein complexes were abolished by tyrosine kinase inhibitor herbimycin A (HA), PI3-kinase/Akt inhibitor LY249002, and MAP kinase kinase inhibitor U0126, while IGF-I effects on HOX-protein complexes were abolished by HA and LY249002. These studies demonstrate that IGF-I stimulates BSP transcription by targeting the FRE and HOX elements in the proximal promoter of BSP gene.

The genomic proliferation of transposable elements in colonizing populations: Schistosoma mansoni in the new world.

PubMed

Wijayawardena, Bhagya K; DeWoody, J Andrew; Minchella, Dennis J

2015-06-01

Transposable elements (TEs) are mobile genes with an inherent ability to move within and among genomes. Theory predicts that TEs proliferate extensively during physiological stress due to the breakdown of TE repression systems. We tested this hypothesis in Schistosoma mansoni, a widespread trematode parasite that causes the human disease schistosomiasis. According to phylogenetic analysis, S. mansoni invaded the new world during the last 500 years. We hypothesized that new world strains of S. mansoni would have more copies of TEs than old world strains due to the physiological stress associated with invasion of the new world. We quantified the copy number of six TEs (Saci-1, Saci-2 and Saci-3, Perere-1, Merlin-sm1, and SmTRC1) in the genome and the transcriptome of old world and new world strains of S. mansoni, using qPCR relative quantification. As predicted, the genomes of new world parasites contain significantly more copies of class I and class II TEs in both laboratory and field strains. However, such differences are not observed in the transcriptome suggesting that either TE silencing mechanisms have reactivated to control the expression of these elements or the presence of inactive truncated copies of TEs.

Plant root proliferation in nitrogen-rich patches confers competitive advantage

PubMed Central

Robinson, D.; Hodge, A.; Griffiths, B. S.; Fitter, A. H.

1999-01-01

Plants respond strongly to environmental heterogeneity, particularly below ground, where spectacular root proliferations in nutrient-rich patches may occur. Such 'foraging' responses apparently maximize nutrient uptake and are now prominent in plant ecological theory. Proliferations in nitrogen-rich patches are difficult to explain adaptively, however. The high mobility of soil nitrate should limit the contribution of proliferation to N capture. Many experiments on isolated plants show only a weak relation between proliferation and N uptake. We show that N capture is associated strongly with proliferation during interspecific competition for finite, locally available, mixed N sources, precisely the conditions under which N becomes available to plants on generally infertile soils. This explains why N-induced root proliferation is an important resource-capture mechanism in N-limited plant communities and suggests that increasing proliferation by crop breeding or genetic manipulation will have a limited impact on N capture by well-fertilized monocultures.

AFRRI (Armed Forces Radiobiology Research Institute) Reports, October, November and December 1987.

DTIC Science & Technology

1988-03-01

cells (Blakely et al., 1979), mouse BalbC 3T3 cells (Ngo et al., 1981), cells grown in multicellular spheroids (Durand and Olive , 1976), in situ mela...0 radiation. It appeared that an experimental elemental diet was associated with both an enhanced cellular proliferation in the blood-forming tissues...elemental diet for I week before irradiation, and the mean survival time was 59 days. Beginning the diet after irradiation offered no protection. Vitamin E

Enhanced expression of cyclins and cyclin-dependent kinases in aniline-induced cell proliferation in rat spleen

PubMed Central

Wang, Jianling; Wang, Gangduo; Ma, Huaxian; Khan, M. Firoze

2010-01-01

Aniline exposure is associated with toxicity to the spleen leading to splenomegaly, hyperplasia, fibrosis and a variety of sarcomas of the spleen on chronic exposure. In earlier studies, we have shown that aniline exposure leads to iron overload, oxidative stress and activation of redox-sensitive transcription factors, which could regulate various genes leading to a tumorigenic response in the spleen. However, molecular mechanisms leading to aniline-induced cellular proliferation in the spleen remain largely unknown. This study was, therefore, undertaken on the regulation of G1 phase cell cycle proteins (cyclins), expression of cyclin-dependent kinases (CDKs), phosphorylation of retinoblastoma protein (pRB) and cell proliferation in the spleen, in an experimental condition preceding a tumorigenic response. Male SD rats were treated with aniline (0.5 mmol/kg/day via drinking water) for 30 days (controls received drinking water only), and splenocyte proliferation, protein expression of G1 phase cyclins, CDKs and pRB were measured. Aniline treatment resulted in significant increases in splenocyte proliferation, based on cell counts, cell proliferation markers including proliferating cell nuclear antigen (PCNA), nuclear Ki67 protein (Ki67) and minichromosome maintenance (MCM), MTT assay and flow cytometric analysis. Western blot analysis of splenocyte proteins from aniline-treated rats showed significantly increased expression of cyclins D1, D2, D3 and cyclin E, as compared to the controls. Similarly, real-time PCR analysis showed significantly increased mRNA expression for cyclins D1, D2, D3 and E in the spleens of aniline-treated rats. The overexpression of these cyclins was associated with increases in the expression of CDK4, CDK6, CDK2 as well as phosphorylation of pRB protein. Our data suggest that increased expression of cyclins, CDKs and phosphorylation of pRB protein could be critical in cell proliferation, and may contribute to aniline-induced tumorigenic response in the spleen. PMID:21070798

Mitochondrial Cardiomyopathy Caused by Elevated Reactive Oxygen Species and Impaired Cardiomyocyte Proliferation.

PubMed

Zhang, Donghui; Li, Yifei; Heims-Waldron, Danielle; Bezzerides, Vassilios; Guatimosim, Silvia; Guo, Yuxuan; Gu, Fei; Zhou, Pingzhu; Lin, Zhiqiang; Ma, Qing; Liu, Jianming; Wang, Da-Zhi; Pu, William T

2018-01-05

Although mitochondrial diseases often cause abnormal myocardial development, the mechanisms by which mitochondria influence heart growth and function are poorly understood. To investigate these disease mechanisms, we studied a genetic model of mitochondrial dysfunction caused by inactivation of Tfam (transcription factor A, mitochondrial), a nuclear-encoded gene that is essential for mitochondrial gene transcription and mitochondrial DNA replication. Tfam inactivation by Nkx2.5 Cre caused mitochondrial dysfunction and embryonic lethal myocardial hypoplasia. Tfam inactivation was accompanied by elevated production of reactive oxygen species (ROS) and reduced cardiomyocyte proliferation. Mosaic embryonic Tfam inactivation confirmed that the block to cardiomyocyte proliferation was cell autonomous. Transcriptional profiling by RNA-seq demonstrated the activation of the DNA damage pathway. Pharmacological inhibition of ROS or the DNA damage response pathway restored cardiomyocyte proliferation in cultured fetal cardiomyocytes. Neonatal Tfam inactivation by AAV9-cTnT-Cre caused progressive, lethal dilated cardiomyopathy. Remarkably, postnatal Tfam inactivation and disruption of mitochondrial function did not impair cardiomyocyte maturation. Rather, it elevated ROS production, activated the DNA damage response pathway, and decreased cardiomyocyte proliferation. We identified a transient window during the first postnatal week when inhibition of ROS or the DNA damage response pathway ameliorated the detrimental effect of Tfam inactivation. Mitochondrial dysfunction caused by Tfam inactivation induced ROS production, activated the DNA damage response, and caused cardiomyocyte cell cycle arrest, ultimately resulting in lethal cardiomyopathy. Normal mitochondrial function was not required for cardiomyocyte maturation. Pharmacological inhibition of ROS or DNA damage response pathways is a potential strategy to prevent cardiac dysfunction caused by some forms of mitochondrial dysfunction. © 2017 American Heart Association, Inc.

Phylogenetic analysis of HERV-K LTR-like elements in primates: presence in some new world monkeys and evidence of recent parallel evolution in these species and in homo sapiens.

PubMed

Kim, H S; Wadekar, R V; Takenaka, O; Hyun, B H; Crow, T J

1999-01-01

Solitary long terminal repeats (LTRs) of the human endogenous retroviruses K family (HERV-K) have been found to be coexpressed with sequences of closely located genes. We identified forty-three HERV-K LTR-like elements in primates (African great apes, two Old World monkeys, and two New World monkeys) and analyzed them along with human-specific HERV-K LTRs. We report detection of HERV-K LTR-like elements from New World monkeys, as represented by the squirrel monkey and the night monkey, for the first time. Analysis revealed a high degree of sequence homology with human-specific HERV-K LTRs. A phylogenetic tree obtained by the neighbor-joining method revealed that five sequence (SMS-1, 2, 5, 6, 7) from the squirrel monkey and three sequences (NM6-4, 5, 9) from the night monkey are more closely related to human-specific HERV-K LTRs than they are to those of apes (the chimpanzee and gorilla) and Old World monkeys (the African green monkey and rhesus monkey). The findings are consistent with the concept the HERV-K LTR-like elements have proliferated independently and recently in the genome of primates, and that such proliferation has been more recent in Homo sapiens and in these representatives of New World monkeys than in some Old World monkeys.

Maintenance of human hyperplastic prostate implants at different sites in athymic mice.

PubMed

Soós, G; Debiec-Rychter, M; Jones, R F; Zukowski, K; Haas, G P; Wang, C Y

1995-01-01

The present study determined the influence of implantation sites, androgens, and the graft's fibrovascular elements on the maintenance of epithelial elements of human benign hyperplastic prostate tissue (BPH) in the nude mouse. BPH fragments prepared from fresh surgical specimens were implanted subcutaneously (s.c.), intraperitoneally (i.p.), or under the renal capsules (r.c.) into male Beige nude mice, which had been implanted s.c. with a Silastic tube filled with 4-dihydrotestosterone (DHT) or cholesterol. Two weeks later the BPH tissues were removed from the mouse and examined microscopically. The implants from all three sites maintained a comparable morphology, with epithelial and/or angio-leiomyomatous stromal hyperplastic appearance, without striking signs of atrophy, irrespective of supplementation with DHT. Expression of proliferating cell nuclear antigen in the implants was comparable, indicating that there was no significant influence of implantation site on the proliferative ability of either epithelia or the stromal fibroblasts. The PCNA-positive cells in the implants, including the vascular and myofibrous elements, hybridized in situ to a human-specific repeated-sequence DNA probe, indicating that these proliferating cells were of human origin. Our data suggest that during the early phases of the adaptation and maintenance of BPH implants, survival of epithelial cells is actively supported by fibro-vascular mesenchymal elements of the prostate grafts in a manner apparently unaffected by DHT supplements.

Sequential activation of CD8+ T cells in the draining lymph nodes in response to pulmonary virus infection.

PubMed

Yoon, Heesik; Legge, Kevin L; Sung, Sun-sang J; Braciale, Thomas J

2007-07-01

We have used a TCR-transgenic CD8+ T cell adoptive transfer model to examine the tempo of T cell activation and proliferation in the draining lymph nodes (DLN) in response to respiratory virus infection. The T cell response in the DLN differed for mice infected with different type A influenza strains with the onset of T cell activation/proliferation to the A/JAPAN virus infection preceding the A/PR8 response by 12-24 h. This difference in T cell activation/proliferation correlated with the tempo of accelerated respiratory DC (RDC) migration from the infected lungs to the DLN in response to influenza virus infection, with the migrant RDC responding to the A/JAPAN infection exhibiting a more rapid accumulation in the lymph nodes (i.e., peak migration for A/JAPAN at 18 h, A/PR8 at 24-36 h). Furthermore, in vivo administration of blocking anti-CD62L Ab at various time points before/after infection revealed that the virus-specific CD8+ T cells entered the DLN and activated in a sequential "conveyor belt"-like fashion. These results indicate that the tempo of CD8+ T cell activation/proliferation after viral infection is dependent on the tempo of RDC migration to the DLN and that T cell activation occurs in an ordered sequential fashion.

Tetranychus urticae mites do not mount an induced immune response against bacteria

PubMed Central

Santos-Matos, Gonçalo; Wybouw, Nicky; Martins, Nelson E.; Zélé, Flore; Riga, Maria; Leitão, Alexandre B.; Vontas, John; Grbić, Miodrag; Van Leeuwen, Thomas; Magalhães, Sara

2017-01-01

The genome of the spider mite Tetranychus urticae, a herbivore, is missing important elements of the canonical Drosophila immune pathways necessary to fight bacterial infections. However, it is not known whether spider mites can mount an immune response and survive bacterial infection. In other chelicerates, bacterial infection elicits a response mediated by immune effectors leading to the survival of infected organisms. In T. urticae, infection by either Escherichia coli or Bacillus megaterium did not elicit a response as assessed through genome-wide transcriptomic analysis. In line with this, spider mites died within days even upon injection with low doses of bacteria that are non-pathogenic to Drosophila. Moreover, bacterial populations grew exponentially inside the infected spider mites. By contrast, Sancassania berlesei, a litter-dwelling mite, controlled bacterial proliferation and resisted infections with both Gram-negative and Gram-positive bacteria lethal to T. urticae. This differential mortality between mite species was absent when mites were infected with heat-killed bacteria. Also, we found that spider mites harbour in their gut 1000-fold less bacteria than S. berlesei. We show that T. urticae has lost the capacity to mount an induced immune response against bacteria, in contrast to other mites and chelicerates but similarly to the phloem feeding aphid Acyrthosiphon pisum. Hence, our results reinforce the putative evolutionary link between ecological conditions regarding exposure to bacteria and the architecture of the immune response. PMID:28592670

Tetranychus urticae mites do not mount an induced immune response against bacteria.

PubMed

Santos-Matos, Gonçalo; Wybouw, Nicky; Martins, Nelson E; Zélé, Flore; Riga, Maria; Leitão, Alexandre B; Vontas, John; Grbić, Miodrag; Van Leeuwen, Thomas; Magalhães, Sara; Sucena, Élio

2017-06-14

The genome of the spider mite Tetranychus urticae , a herbivore, is missing important elements of the canonical Drosophila immune pathways necessary to fight bacterial infections. However, it is not known whether spider mites can mount an immune response and survive bacterial infection. In other chelicerates, bacterial infection elicits a response mediated by immune effectors leading to the survival of infected organisms. In T. urticae , infection by either Escherichia coli or Bacillus megaterium did not elicit a response as assessed through genome-wide transcriptomic analysis. In line with this, spider mites died within days even upon injection with low doses of bacteria that are non-pathogenic to Drosophila Moreover, bacterial populations grew exponentially inside the infected spider mites. By contrast, Sancassania berlesei , a litter-dwelling mite, controlled bacterial proliferation and resisted infections with both Gram-negative and Gram-positive bacteria lethal to T. urticae This differential mortality between mite species was absent when mites were infected with heat-killed bacteria. Also, we found that spider mites harbour in their gut 1000-fold less bacteria than S. berlesei We show that T. urticae has lost the capacity to mount an induced immune response against bacteria, in contrast to other mites and chelicerates but similarly to the phloem feeding aphid Acyrthosiphon pisum Hence, our results reinforce the putative evolutionary link between ecological conditions regarding exposure to bacteria and the architecture of the immune response. © 2017 The Authors.

Emergent cell and tissue dynamics from subcellular modeling of active biomechanical processes

NASA Astrophysics Data System (ADS)

Sandersius, S. A.; Weijer, C. J.; Newman, T. J.

2011-08-01

Cells and the tissues they form are not passive material bodies. Cells change their behavior in response to external biochemical and biomechanical cues. Behavioral changes, such as morphological deformation, proliferation and migration, are striking in many multicellular processes such as morphogenesis, wound healing and cancer progression. Cell-based modeling of these phenomena requires algorithms that can capture active cell behavior and their emergent tissue-level phenotypes. In this paper, we report on extensions of the subcellular element model to model active biomechanical subcellular processes. These processes lead to emergent cell and tissue level phenotypes at larger scales, including (i) adaptive shape deformations in cells responding to slow stretching, (ii) viscous flow of embryonic tissues, and (iii) streaming patterns of chemotactic cells in epithelial-like sheets. In each case, we connect our simulation results to recent experiments.

Oligodeoxynucleotides Expressing Polyguanosine Motifs Promote Anti-Tumor Activity through the Up-Regulation of IL-2

PubMed Central

Kobayashi, Nobuaki; Hong, Choongman; Klinman, Dennis M.; Shirota, Hidekazu

2012-01-01

The primary goal of cancer immunotherapy is to elicit an immune response capable of eliminating the tumor. One approach towards accomplishing that goal utilizes general (rather than tumor-specific) immunomodulatory agents to boost the number and activity of pre-existing cytotoxic T lymphocytes. We find that the intra-tumoral injection of poly-G ODN has such an effect, boosting anti-tumor immunity and promoting tumor regression. The anti-tumor activity of polyguanosine (poly-G) oligonucleotides (ODN) was mediated through CD8 T cells in a TLR9 independent manner. Mechanistically, poly-G ODN directly induced the phosphorylation of Lck (an essential element of the T cell signaling pathway), thereby enhancing the production of IL-2 and CD8 T cell proliferation. These findings establish poly-G ODN as a novel type of cancer immunotherapy. PMID:23296706

Proliferation of pronephric lymphocytes of carp, Cyprinus carpio induced by extracts of Bothriocephalus acheilognathi.

PubMed

Nie, P; Hoole, D; Arme, C

1996-06-01

The interaction between Bothriocephalus acheilognathi Yamaguti, 1934 (Cestoda) and pronephric lymphocytes of carp, Cyprinus carpio L. was studied by examining proliferation of lymphocytes isolated from both naïve fish and fish injected intraperitoneally with cestode extract. Lymphocytes from naïve hosts were stimulated to proliferate in the presence of the extract depending upon the extract protein concentrations; lower concentrations (0.01-0.05 microgram/ml) induced the greatest response, and immunosuppression occurred at higher concentrations. Significant differences were noted in fish that received intraperitoneal injections of parasite extracts. Five days post-injection, lymphocyte proliferation was significantly greater in these individuals compared with sham injected or untreated controls. This difference was reduced at 10 days post-injection, although the response was dependent on the concentration of the parasite extract. The possible significance of the observed stimulation/suppression of lymphocyte activity to establishment of the parasite in the wild is discussed.

Lipocalin-2 Promotes Endoplasmic Reticulum Stress and Proliferation by Augmenting Intracellular Iron in Human Pulmonary Arterial Smooth Muscle Cells

PubMed Central

Wang, Guoliang; Liu, Shenghua; Wang, Li; Meng, Liukun; Cui, Chuanjue; Zhang, Hao; Hu, Shengshou; Ma, Ning; Wei, Yingjie

2017-01-01

Endoplasmic reticulum (ER) stress, a feature of many conditions associated with pulmonary hypertension (PH), is increasingly recognized as a common response to promote proliferation in the walls of pulmonary arteries. Increased expression of Lipocalin-2 in PH led us to test the hypothesis that Lipocalin-2, a protein known to sequester iron and regulate it intracellularly, might facilitate the ER stress and proliferation in pulmonary arterial smooth muscle cells (PASMCs). In this study, we observed greatly increased Lcn2 expression accompanied with increased ATF6 cleavage in a standard rat model of pulmonary hypertension induced by monocrotaline. In cultured human PASMCs, Lcn2 significantly promoted ER stress (determined by augmented cleavage and nuclear localization of ATF6, up-regulated transcription of GRP78 and NOGO, increased expression of SOD2, and mild augmented mitochondrial membrane potential) and proliferation (assessed by Ki67 staining and BrdU incorporation). Lcn2 promoted ER stress accompanied with augmented intracellular iron levels in human PASMCs. Treatment human PASMCs with FeSO4 induced the similar ER stress and proliferation response and iron chelator (deferoxamine) abrogated the ER stress and proliferation induced by Lcn2 in cultured human PASMCs. In conclusion, Lcn2 significantly promoted human PASMC ER stress and proliferation by augmenting intracellular iron. The up-regulation of Lcn2 probably involved in the pathogenesis and progression of PH. PMID:28255266

Early divergent host responses in SHIVsf162P3 and SIVmac251 infected macaques correlate with control of viremia.

PubMed

Xu, Huanbin; Wang, Xiaolei; Morici, Lisa A; Pahar, Bapi; Veazey, Ronald S

2011-03-25

We previously showed intravaginal inoculation with SHIVsf162p3 results in transient viremia followed by undetectable viremia in most macaques, and some displayed subsequent immunity to superinfection with pathogenic SIVmac251. Here we compare early T cell activation, proliferation, and plasma cytokine/chemokine responses in macaques intravaginally infected with either SHIVsf162p3 or SIVmac251 to determine whether distinct differences in host responses may be associated with early viral containment. The data show SIVmac251 infection results in significantly higher levels of T cell activation, proliferation, and a mixed cytokine/chemokine "storm" in plasma in primary infection, whereas infection with SHIVsf162p3 resulted in significantly lower levels of T cell activation, proliferation, and better preservation of memory CD4+ T cells in early infection which immediately preceded control of viremia. These results support the hypothesis that early systemic immune activation, T cell proliferation, and a more prominent and broader array of cytokine/chemokine responses facilitate SIV replication, and may play a key role in persistence of infection, and the progression to AIDS. In contrast, immune unresponsiveness may be associated with eventual clearance of virus, a concept that may have key significance for therapy and vaccine design.

Role of selenium-containing proteins in T cell and macrophage function

PubMed Central

Carlson, Bradley A.; Yoo, Min-Hyuk; Shrimali, Rajeev K.; Irons, Robert; Gladyshev, Vadim N.; Hatfield, Dolph L.; Park, Jin Mo

2011-01-01

Synopsis Selenium has been known for many years to have a role in boosting immune function, but the manner in which this element acts at the molecular level in host defense and inflammatory diseases is poorly understood. To elucidate the role of selenium-containing proteins in immune function, we knocked out the expression of this protein class in T cells or macrophages of mice by targeting the removal of the selenocysteine tRNA gene using loxP-Cre technology. Mice with selenoprotein-less T cells manifested reduced pools of mature and functional T cells in lymphoid tissues and an impairment in T cell-dependent antibody responses. Furthermore, selenoprotein deficiency in T cells led to an inability of these cells to suppress reactive oxygen species (ROS) production, which in turn affected their ability to proliferate in response to T cell receptor stimulation. Selenoprotein-less macrophages, on the other hand, manifested mostly normal inflammatory responses, but this deficiency resulted in an altered regulation in extracellular matrix-related gene expression and a diminished migration of macrophages in a protein gel matrix. These observations provided novel insights into the role of selenoproteins in immune function and tissue homeostasis. PMID:20576203

Interactions between human mesenchymal stem cells and natural killer cells.

PubMed

Sotiropoulou, Panagiota A; Perez, Sonia A; Gritzapis, Angelos D; Baxevanis, Constantin N; Papamichail, Michael

2006-01-01

Mesenchymal stem cells (MSCs) are multipotent progenitor cells representing an attractive therapeutic tool for regenerative medicine. They possess unique immunomodulatory properties, being capable of suppressing T-cell responses and modifying dendritic cell differentiation, maturation, and function, whereas they are not inherently immunogenic, failing to induce alloreactivity to T cells and freshly isolated natural killer (NK) cells. To clarify the generation of host immune responses to implanted MSCs in tissue engineering and their potential use as immunosuppressive elements, the effect of MSCs on NK cells was investigated. We demonstrate that at low NK-to-MSC ratios, MSCs alter the phenotype of NK cells and suppress proliferation, cytokine secretion, and cyto-toxicity against HLA-class I- expressing targets. Some of these effects require cell-to-cell contact, whereas others are mediated by soluble factors, including transforming growth factor-beta1 and prostaglandin E2, suggesting the existence of diverse mechanisms for MSC-mediated NK-cell suppression. On the other hand, MSCs are susceptible to lysis by activated NK cells. Overall, these data improve our knowledge of interactions between MSCs and NK cells and consequently of their effect on innate immune responses and their contribution to the regulation of adaptive immunity, graft rejection, and cancer immunotherapy.

Non-alcoholic beverages, unknown influence on cell proliferation - an in vitro study.

PubMed

Nowacki, Maciej; Adamowicz, Jan; Olkowska, Joanna; Pietkun, Katarzyna; Kloskowski, Tomasz; Bajek, Anna; Drewa, Tomasz

2014-01-01

The aim of the presented study was to check differences between 'Diet' and 'non-Diet' soft drinks on cell proliferation. Coca Cola and Pepsi Cola of different origin and their dietetic versions were examined at concentrations of 2% and 4%. Fructose and glucose as well as medium alone (control) were examined. Cell number was higher in media supplemented with soft drinks, compared to control. Proliferation depended on the soft drink concentration and its origin, but not on sugar and calorific content. An unknown factor is responsible for the increase in proliferation.

S-Nitrosation of monocarboxylate transporter 1: Inhibition of pyruvate-fueled respiration and proliferation of breast cancer cells

PubMed Central

Diers, Anne R.; Broniowska, Katarzyna A.; Chang, Ching-Fang; Hill, R. Blake; Hogg, Neil

2014-01-01

Summary Energy substrates metabolized through mitochondria (e.g., pyruvate, glutamine) are required for biosynthesis of macromolecules in proliferating cells. Since several mitochondrial proteins are known to be targets of S-nitrosation, we determined whether bioenergetics are modulated by S-nitrosation and defined the subsequent effects on proliferation. The nitrosating agent S-nitroso-L-cysteine (L-CysNO) was used to initiate intracellular S-nitrosation, and treatment decreased mitochondrial function and inhibited proliferation of MCF7 mammary adenocarcinoma cells. Surprisingly, the D isomer of CysNO (D-CysNO) which is not transported into cells also caused mitochondrial dysfunction and limited proliferation. Both L- and D-CysNO also inhibited cellular pyruvate uptake and caused S-nitrosation of thiol groups on monocarboxylate transporter 1, a proton-linked pyruvate transporter. These data demonstrate the importance of mitochondrial metabolism in proliferative responses in breast cancer and highlight a novel role for inhibition of metabolic substrate uptake through S-nitrosation of exofacial protein thiols in cellular responses to nitrosative stress. PMID:24486553

Effects of different transferrin forms on transferrin receptor expression, iron uptake, and cellular proliferation of human leukemic HL60 cells. Mechanisms responsible for the specific cytotoxicity of transferrin-gallium.

PubMed Central

Chitambar, C R; Seligman, P A

1986-01-01

We have previously shown that human leukemic cells proliferate normally in serum-free media containing various transferrin forms, but the addition of transferrin-gallium leads to inhibition of cellular proliferation. Because gallium has therapeutic potential, the effects of transferrin-gallium on leukemic cell proliferation, transferrin receptor expression, and cellular iron utilization were studied. The cytotoxicity of gallium is considerably enhanced by its binding to transferrin and cytotoxicity can be reversed by transferrin-iron but not by other transferrin forms. Exposure to transferrin-gallium leads to a marked increase in cell surface transferrin binding sites, but despite this, cellular 59Fe incorporation is inappropriately low. Although shunting of transferrin-gallium to another cellular compartment has not been ruled out, other studies suggest that transferrin-gallium impairs intracellular release of 59Fe from transferrin by interfering with processes responsible for intracellular acidification. These studies, taken together, demonstrate that inhibition of cellular iron incorporation by transferrin-gallium is a prerequisite for inhibition of cellular proliferation. PMID:3465751

Atractylenolide I restores HO-1 expression and inhibits Ox-LDL-induced VSMCs proliferation, migration and inflammatory responses in vitro

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Weifeng, E-mail: liwf@mail.xjtu.edu.cn; Zhi, Wenbing; Liu, Fang

Pathogenesis of atherosclerosis is characterized by the proliferation and migration of vascular smooth muscle cells (VSMCs) and inflammatory lesions. The aim of this study is to elucidate the effect of atractylenolide I (AO-I) on smooth muscle cell inflammation, proliferation and migration induced by oxidized modified low density lipoprotein (Ox-LDL). Here, We found that atractylenolide I inhibited Ox-LDL-induced VSMCs proliferation and migration in a dose-dependent manner, and decreased the production of inflammatory cytokines and the expression of monocyte chemoattractant protein-1 (MCP-1) in VSMCs. The study also identified that AO-I prominently inhibited p38-MAPK and NF-κB activation. More importantly, the specific heme oxygenase-1more » (HO-1) inhibitor zinc protoporphyrin (ZnPP) IX partially abolished the beneficial effects of atractylenolide I on Ox-LDL-induced VSMCs. Furthermore, atractylenolide I blocked the foam cell formation in macrophages induced by Ox-LDL. In summary, inhibitory roles of AO-I in VSMCs proliferation and migration, lipid peroxidation and subsequent inflammatory responses might contribute to the anti-atherosclerotic property of AO-I. - Highlights: • AO-I inhibited Ox-LDL-induced VSMCs proliferation and migration. • AO-I alleviated inflammatory response via inhibiting TNF-α, IL-6 and NO production. • AO-I restored HO-1 expression and down-regulated PCNA expression. • MCP-1 overexpression is potentially regulated by NF-κB and p38 MAPK pathway. • AO-I possesses strong anti-lipid peroxidation effect.« less

Chlorinated dibenzo-P-dioxins and dibenzofurans and the human immune system (2) In vitro proliferation of lymphocytes from workers with quantified moderately-increased body burdens

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neubert, R.; Maskow, L.; Delgado, I.

1995-11-01

Lymphocyte proliferation responses were studied in workers with moderately increased body burdens of 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin and other polychlorinated dibenzo-p-dioxin and other polyclorinated dibenzo-p-dioxins and dibenzofurans (PCDDs/PCDFs), calculated as International Toxicity Equivalencies [I-TE]. Mitogens (pokeweed mitogen [PWM], phytohemagglutinine [PHA], concanavalin A [Con A], as well as anti-human monoclonal antibody against CD3 were used as proliferation stimulators in vitro. Additionally, the feasibility of using the lymphocyte response to tetanus toxoid was assessed, and the response to this recall-antigen was included in this trial. No decrease in the capacity of {sup 3}H-thymidine incorporation was observed with any of the proliferation stimulatorsmore » in the group of volunteers with the increased TCDD-body burden when compared with volunteers exhibiting TCDD-concentrations in blood flat within the reference range. Regression analysis revealed a slight trend towards an increase for {sup 3}H-thymidine incorporation during the stimulation with PHA only. It can be concluded from our data that moderates increases in the TCDD- or I-TE-body burdens do not induce any medically significant changes in the capacity for proliferation of lymphocytes, measured as {sub 3}H=thymidine incorporation. 25 refs., 5 figs., 3 tabs.« less

Thiazolidinediones inhibit REG I{alpha} gene transcription in gastrointestinal cancer cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yamauchi, Akiyo; Laboratory of Molecular Genetics, Tohoku University Graduate School of Pharmaceutical Sciences, Sendai 980-8578; Department of Biochemistry, Nara Medical University, Kashihara 634-8521

2009-02-13

REG (Regenerating gene) I{alpha} protein functions as a growth factor for gastrointestinal cancer cells, and its mRNA expression is strongly associated with a poor prognosis in gastrointestinal cancer patients. We here demonstrated that PPAR{gamma}-agonist thiazolidinediones (TZDs) inhibited cell proliferation and REG I{alpha} protein/mRNA expression in gastrointestinal cancer cells. TZDs inhibited the REG I{alpha} gene promoter activity, via its cis-acting element which lacked PPAR response element and could not bind to PPAR{gamma}, in PPAR{gamma}-expressing gastrointestinal cancer cells. The inhibition was reversed by co-treatment with a specific PPAR{gamma}-antagonist GW9662. Although TZDs did not inhibit the REG I{alpha} gene promoter activity in PPAR{gamma}-non-expressingmore » cells, PPAR{gamma} overexpression in the cells recovered their inhibitory effect. Taken together, TZDs inhibit REG I{alpha} gene transcription through a PPAR{gamma}-dependent pathway. The TZD-induced REG I{alpha} mRNA reduction was abolished by cycloheximide, indicating the necessity of novel protein(s) synthesis. TZDs may therefore be a candidate for novel anti-cancer drugs for patients with gastrointestinal cancer expressing both REG I{alpha} and PPAR{gamma}.« less

Goldilocks and the three inorganic equilibria: how Earth's chemistry and life coevolve to be nearly in tune.

PubMed

Rickaby, R E M

2015-03-13

Life and the chemical environment are united in an inescapable feedback cycle. The periodic table of the elements essential for life has transformed over Earth's history, but, as today, evolved in tune with the elements available in abundance in the environment. The most revolutionary time in life's history was the advent and proliferation of oxygenic photosynthesis which forced the environment towards a greater degree of oxidation. Consideration of three inorganic chemical equilibria throughout this gradual oxygenation prescribes a phased release of trace metals to the environment, which appear to have coevolved with employment of these new chemicals by life. Evolution towards complexity was chemically constrained, and changes in availability of notably Fe, Zn and Cu paced the systematic development of complex organisms. Evolving life repeatedly catalysed its own chemical challenges via the unwitting release of new and initially toxic chemicals. Ultimately, the harnessing of these allowed life to advance to greater complexity, though the mechanism responsible for translating novel chemistry to heritable use remains elusive. Whether a chemical acts as a poison or a nutrient lies both in the dose and in its environmental history. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Estradiol induces endothelial cell migration and proliferation through estrogen receptor-enhanced RhoA/ROCK pathway.

PubMed

Oviedo, Pilar J; Sobrino, Agua; Laguna-Fernandez, Andrés; Novella, Susana; Tarín, Juan J; García-Pérez, Miguel-Angel; Sanchís, Juan; Cano, Antonio; Hermenegildo, Carlos

2011-03-30

Migration and proliferation of endothelial cells are involved in re-endothelialization and angiogenesis, two important cardiovascular processes that are increased in response to estrogens. RhoA, a small GTPase which controls multiple cellular processes, is involved in the control of cell migration and proliferation. Our aim was to study the role of RhoA on estradiol-induced migration and proliferation and its dependence on estrogen receptors activity. Human umbilical vein endothelial cells were stimulated with estradiol, in the presence or absence of ICI 182780 (estrogen receptors antagonist) and Y-27632 (Rho kinase inhibitor). Estradiol increased Rho GEF-1 gene expression and RhoA (gene and protein expression and activity) in an estrogen receptor-dependent manner. Cell migration, stress fiber formation and cell proliferation were increased in response to estradiol and were also dependent on the estrogen receptors and RhoA activation. Estradiol decreased p27 levels, and significantly raised the expression of cyclins and CDK. These effects were counteracted by the use of either ICI 182780 or Y-27632. In conclusion, estradiol enhances the RhoA/ROCK pathway and increases cell cycle-related protein expression by acting through estrogen receptors. This results in an enhanced migration and proliferation of endothelial cells. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Non-Thermal Atmospheric Pressure Plasma Efficiently Promotes the Proliferation of Adipose Tissue-Derived Stem Cells by Activating NO-Response Pathways

PubMed Central

Park, Jeongyeon; Lee, Hyunyoung; Lee, Hae June; Kim, Gyoo Cheon; Kim, Do Young; Han, Sungbum; Song, Kiwon

2016-01-01

Non-thermal atmospheric pressure plasma (NTAPP) is defined as a partially ionized gas with electrically charged particles at atmospheric pressure. Our study showed that exposure to NTAPP generated in a helium-based dielectric barrier discharge (DBD) device increased the proliferation of adipose tissue-derived stem cells (ASCs) by 1.57-fold on an average, compared with untreated cells at 72 h after initial NTAPP exposure. NTAPP-exposed ASCs maintained their stemness, capability to differentiate into adipocytes but did not show cellular senescence. Therefore, we suggested that NTAPP can be used to increase the proliferation of ASCs without affecting their stem cell properties. When ASCs were exposed to NTAPP in the presence of a nitric oxide (NO) scavenger, the proliferation-enhancing effect of NTAPP was not obvious. Meanwhile, the proliferation of NTAPP-exposed ASCs was not much changed in the presence of scavengers for reactive oxygen species (ROS). Also, Akt, ERK1/2, and NF-κB were activated in ASCs after NTAPP exposure. These results demonstrated that NO rather than ROS is responsible for the enhanced proliferation of ASCs following NTAPP exposure. Taken together, this study suggests that NTAPP would be an efficient tool for use in the medical application of ASCs both in vitro and in vivo. PMID:27991548

A Somatically Acquired Enhancer of the Androgen Receptor Is a Noncoding Driver in Advanced Prostate Cancer.

PubMed

Takeda, David Y; Spisák, Sándor; Seo, Ji-Heui; Bell, Connor; O'Connor, Edward; Korthauer, Keegan; Ribli, Dezső; Csabai, István; Solymosi, Norbert; Szállási, Zoltán; Stillman, David R; Cejas, Paloma; Qiu, Xintao; Long, Henry W; Tisza, Viktória; Nuzzo, Pier Vitale; Rohanizadegan, Mersedeh; Pomerantz, Mark M; Hahn, William C; Freedman, Matthew L

2018-06-09

Increased androgen receptor (AR) activity drives therapeutic resistance in advanced prostate cancer. The most common resistance mechanism is amplification of this locus presumably targeting the AR gene. Here, we identify and characterize a somatically acquired AR enhancer located 650 kb centromeric to the AR. Systematic perturbation of this enhancer using genome editing decreased proliferation by suppressing AR levels. Insertion of an additional copy of this region sufficed to increase proliferation under low androgen conditions and to decrease sensitivity to enzalutamide. Epigenetic data generated in localized prostate tumors and benign specimens support the notion that this region is a developmental enhancer. Collectively, these observations underscore the importance of epigenomic profiling in primary specimens and the value of deploying genome editing to functionally characterize noncoding elements. More broadly, this work identifies a therapeutic vulnerability for targeting the AR and emphasizes the importance of regulatory elements as highly recurrent oncogenic drivers. Copyright © 2018 Elsevier Inc. All rights reserved.

Requirement of ERα and basal activities of EGFR and Src kinase in Cd-induced activation of MAPK/ERK pathway in human breast cancer MCF-7 cells.

PubMed

Song, Xiulong; Wei, Zhengxi; Shaikh, Zahir A

2015-08-15

Cadmium (Cd) is a common environmental toxicant and an established carcinogen. Epidemiological studies implicate Cd with human breast cancer. Low micromolar concentrations of Cd promote proliferation of human breast cancer cells in vitro. The growth promotion of breast cancer cells is associated with the activation of MAPK/ERK pathway. This study explores the mechanism of Cd-induced activation of MAPK/ERK pathway. Specifically, the role of cell surface receptors ERα, EGFR, and Src kinase was evaluated in human breast cancer MCF-7 cells treated with 1-3μM Cd. The activation of ERK was studied using a serum response element (SRE) luciferase reporter assay. Receptor phosphorylation was detected by Western blot analyses. Cd treatment increased both the SRE reporter activity and ERK1/2 phosphorylation in a concentration-dependent manner. Cd treatment had no effect on reactive oxygen species (ROS) generation. Also, blocking the entry of Cd into the cells with manganese did not diminish Cd-induced activation of MAPK/ERK. These results suggest that the effect of Cd was likely not caused by intracellular ROS generation, but through interaction with the membrane receptors. While Cd did not appear to activate either EGFR or Src kinase, their inhibition completely blocked the Cd-induced activation of ERK as well as cell proliferation. Similarly, silencing ERα with siRNA or use of ERα antagonist blocked the effects of Cd. Based on these results, it is concluded that not only ERα, but also basal activities of EGFR and Src kinase are essential for Cd-induced signal transduction and activation of MAPK/ERK pathway for breast cancer cell proliferation. Copyright © 2015 Elsevier Inc. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luo, Shuang, E-mail: luoshuangsch@163.com; Wang, Jidong; Ma, Ying

miR-125b has essential roles in coordinating tumor proliferation, angiogenesis, invasiveness, metastasis and chemotherapy recurrence. In ovarian cancer miR-125b has been shown to be downregulated and acts as a tumor suppressor by targeting proto-oncogene BCL3. PPARγ, a multiple functional transcription factor, has been reported to have anti-tumor effects through inhibition of proliferation and induction of differentiation and apoptosis by targeting the tumor related genes. However, it is unclear whether miR-125b is regulated by PPARγ in ovarian cancer. In this study, we demonstrated that the miR-125b downregulated in ovarian cancer tissues and cell lines. Ligands-activated PPARγ suppressed proliferation of ovarian cancer cellsmore » and this PPARγ-induced growth inhibition is mediated by the upregulation of miR-125b. PPARγ promoted the expression of miR-125b by directly binding to the responsive element in miR-125b gene promoter region. Thus, our results suggest that PPARγ can induce growth suppression of ovarian cancer by upregulating miR-125b which inhibition of proto-oncogene BCL3. These findings will extend our understanding of the function of PPARγ in tumorigenesis and miR-125b may be a therapeutic intervention of ovarian cancer. - Highlights: • miR-125b is down-regulated in ovarian cancer tissues and cells. • PPARγ upregulates miR-125b and downregulates its target gene BCL3 expression. • Silence of miR-125b attenuates PPARγ-mediated growth suppression of ovarian cancer cells. • PPARγ promotes the transcription of miR-125b via binding to PPARE in miR-125b gene promoter region.« less

Transient Proliferation of Proanthocyanidin-Accumulating Cells on the Epidermal Apex Contributes to Highly Aluminum-Resistant Root Elongation in Camphor Tree1[W

PubMed Central

Osawa, Hiroki; Endo, Izuki; Hara, Yukari; Matsushima, Yuki; Tange, Takeshi

2011-01-01

Aluminum (Al) is a harmful element that rapidly inhibits the elongation of plant roots in acidic soils. The release of organic anions explains Al resistance in annual crops, but the mechanisms that are responsible for superior Al resistance in some woody plants remain unclear. We examined cell properties at the surface layer of the root apex in the camphor tree (Cinnamomum camphora) to understand its high Al resistance mechanism. Exposure to 500 μm Al for 8 d, more than 20-fold higher concentration and longer duration than what soybean (Glycine max) can tolerate, only reduced root elongation in the camphor tree to 64% of the control despite the slight induction of citrate release. In addition, Al content in the root apices was maintained at low levels. Histochemical profiling revealed that proanthocyanidin (PA)-accumulating cells were present at the adjacent outer layer of epidermis cells at the root apex, having distinctive zones for cell division and the early phase of cell expansion. Then the PA cells were gradually detached off the root, leaving thin debris behind, and the root surface was replaced with the elongating epidermis cells at the 3- to 4-mm region behind the tip. Al did not affect the proliferation of PA cells or epidermis cells, except for the delay in the start of expansion and the accelerated detachment of the former. In soybean roots, the innermost lateral root cap cells were absent in both PA accumulation and active cell division and failed to protect the epidermal cell expansion at 25 μm Al. These results suggest that transient proliferation and detachment of PA cells may facilitate the expansion of epidermis cells away from Al during root elongation in camphor tree. PMID:21045123

Transient proliferation of proanthocyanidin-accumulating cells on the epidermal apex contributes to highly aluminum-resistant root elongation in camphor tree.

PubMed

Osawa, Hiroki; Endo, Izuki; Hara, Yukari; Matsushima, Yuki; Tange, Takeshi

2011-01-01

Aluminum (Al) is a harmful element that rapidly inhibits the elongation of plant roots in acidic soils. The release of organic anions explains Al resistance in annual crops, but the mechanisms that are responsible for superior Al resistance in some woody plants remain unclear. We examined cell properties at the surface layer of the root apex in the camphor tree (Cinnamomum camphora) to understand its high Al resistance mechanism. Exposure to 500 μm Al for 8 d, more than 20-fold higher concentration and longer duration than what soybean (Glycine max) can tolerate, only reduced root elongation in the camphor tree to 64% of the control despite the slight induction of citrate release. In addition, Al content in the root apices was maintained at low levels. Histochemical profiling revealed that proanthocyanidin (PA)-accumulating cells were present at the adjacent outer layer of epidermis cells at the root apex, having distinctive zones for cell division and the early phase of cell expansion. Then the PA cells were gradually detached off the root, leaving thin debris behind, and the root surface was replaced with the elongating epidermis cells at the 3- to 4-mm region behind the tip. Al did not affect the proliferation of PA cells or epidermis cells, except for the delay in the start of expansion and the accelerated detachment of the former. In soybean roots, the innermost lateral root cap cells were absent in both PA accumulation and active cell division and failed to protect the epidermal cell expansion at 25 μm Al. These results suggest that transient proliferation and detachment of PA cells may facilitate the expansion of epidermis cells away from Al during root elongation in camphor tree.

Upregulation of cell proliferation via Shc and ERK1/2 MAPK signaling in SaOS-2 osteoblasts grown on magnesium alloy surface coating with tricalcium phosphate.

PubMed

Jiang, Tianlong; Guo, Lei; Ni, Shenghui; Zhao, Yuyan

2015-04-01

Magnesium (Mg) alloys have been demonstrated to be viable orthopedic implants because of mechanical and biocompatible properties similar to natural bone. In order to improve its osteogenic properties, a porous β-tricalcium phosphate (β-TCP) was coated on the Mg-3AI-1Zn alloy by alkali-heat treatment technique. The human bone-derived cells (SaOS-2) were cultured on (β-TCP)-Mg-3AI-1Zn in vitro, and the osteoblast response, the morphology and the elements on this alloy surface were investigated. Also, the regulation of key intracellular signalling proteins was investigated in the SaOS-2 cells cultured on alloy surface. The results from scanning electron microscope and immunofluorescence staining demonstrated that (β-TCP)-Mg-3AI-1Zn induced significant osteogenesis. SaOS-2 cell proliferation was improved by β-TCP coating. Moreover, the (β-TCP)-Mg-3AI-1Zn surface induced activation of key intracellular signalling proteins in SaOS-2 cells. We observed an enhanced activation of Src homology and collagen (Shc), a common point of integration between bone morphogenetic protein 2, and the Ras/mitogen-activated protein kinase (MAPK) pathway. ERK1/2 MAP kinase activation was also upregulated, suggesting a role in mediating osteoblastic cell interactions with biomaterials. The signalling pathway involving c-fos (member of the activated protein-1) was also shown to be upregulated in osteoblasts cultured on the (β-TCP)-Mg-3AI-1Zn. These results suggest that β-TCP coating may contribute to successful osteoblast function on Mg alloy surface. (β-TCP)-Mg-3AI-1Zn may upregulate cell proliferation via Shc and ERK1/2 MAPK signaling in SaOS-2 osteoblasts grown on Mg alloy surface.

Niclosamide suppresses acute myeloid leukemia cell proliferation through inhibition of CREB-dependent signaling pathways

PubMed Central

Chae, Hee-Don; Cox, Nick; Dahl, Gary V.; Lacayo, Norman J.; Davis, Kara L.; Capolicchio, Samanta; Smith, Mark; Sakamoto, Kathleen M.

2018-01-01

CREB (cAMP Response Element Binding protein) is a transcription factor that is overexpressed in primary acute myeloid leukemia (AML) cells and associated with a decreased event-free survival and increased risk of relapse. We recently reported a small molecule inhibitor of CREB, XX-650-23, which inhibits CREB activity in AML cells. Structure-activity relationship analysis for chemical compounds with structures similar to XX-650-23 led to the identification of the anthelminthic drug niclosamide as a potent anti-leukemic agent that suppresses cell viability of AML cell lines and primary AML cells without a significant decrease in colony forming activity of normal bone marrow cells. Niclosamide significantly inhibited CREB function and CREB-mediated gene expression in cells, leading to apoptosis and G1/S cell cycle arrest with reduced phosphorylated CREB levels. CREB knockdown protected cells from niclosamide treatment-mediated cytotoxic effects. Furthermore, treatment with a combination of niclosamide and CREB inhibitor XX-650-23 showed an additive anti-proliferative effect, consistent with the hypothesis that niclosamide and XX-650-23 regulate the same targets or pathways to inhibit proliferation and survival of AML cells. Niclosamide significantly inhibited the progression of disease in AML patient-derived xenograft (PDX) mice, and prolonged survival of PDX mice. Niclosamide also showed synergistic effects with chemotherapy drugs to inhibit AML cell proliferation. While chemotherapy antagonized the cytotoxic potential of niclosamide, pretreatment with niclosamide sensitized cells to chemotherapeutic drugs, cytarabine, daunorubicin, and vincristine. Therefore, our results demonstrate niclosamide as a potential drug to treat AML by inducing apoptosis and cell cycle arrest through inhibition of CREB-dependent pathways in AML cells. PMID:29435104

Bathing in carbon dioxide-enriched water alters protein expression in keratinocytes of skin tissue in rats.

PubMed

Kälsch, Julia; Pott, Leona L; Takeda, Atsushi; Kumamoto, Hideo; Möllmann, Dorothe; Canbay, Ali; Sitek, Barbara; Baba, Hideo A

2017-04-01

Beneficial effects of balneotherapy using naturally occurring carbonated water (CO 2 enriched) have been known since the Middle Ages. Although this therapy is clinically applied for peripheral artery disease and skin disorder, the underlying mechanisms are not fully elucidated.Under controlled conditions, rats were bathed in either CO 2 -enriched water (CO 2 content 1200 mg/L) or tap water, both at 37 °C, for 10 min daily over 4 weeks. Proliferation activity was assessed by Ki67 immunohistochemistry of the epidermis of the abdomen. The capillary density was assessed by immunodetection of isolectin-positive cells. Using cryo-fixed abdominal skin epidermis, follicle cells and stroma tissue containing capillaries were separately isolated by means of laser microdissection and subjected to proteomic analysis using label-free technique. Differentially expressed proteins were validated by immunohistochemistry.Proliferation activity of keratinocytes was not significantly different in the epidermis after bathing in CO 2 -enriched water, and also, capillary density did not change. Proteomic analysis revealed up to 36 significantly regulated proteins in the analyzed tissue. Based on the best expression profiles, ten proteins were selected for immunohistochemical validation. Only one protein, far upstream element binding protein 2 (FUBP2), was similarly downregulated in the epidermis after bathing in CO 2 -enriched water with both techniques. Low FUBP2 expression was associated with low c-Myc immune-expression in keratinocytes.Long-term bathing in CO 2 -enriched water showed a cellular protein response of epithelial cells in the epidermis which was detectable by two different methods. However, differences in proliferation activity or capillary density were not detected in the normal skin.

Discovery of peroxisome proliferator-activated receptor α (PPARα) activators with a ligand-screening system using a human PPARα-expressing cell line.

PubMed

Tachibana, Keisuke; Yuzuriha, Tomohiro; Tabata, Ryotaro; Fukuda, Syohei; Maegawa, Takashi; Takahashi, Rika; Tanimoto, Keiichi; Tsujino, Hirofumi; Nunomura, Kazuto; Lin, Bangzhong; Matsuura, Yoshiharu; Tanaka, Toshiya; Hamakubo, Takao; Sakai, Juro Js; Kodama, Tatsuhiko; Kobayashi, Tadayuki; Ishimoto, Kenji; Miyachi, Hiroyuki; Doi, Takefumi

2018-05-15

Peroxisome proliferator-activated receptor alpha (PPARα) is a ligand-activated transcription factor that belongs to the superfamily of nuclear hormone receptors. PPARα is mainly expressed in the liver, where it activates fatty acid oxidation and lipoprotein metabolism and improves plasma lipid profiles. Therefore, PPARα activators are often used to treat patients with dyslipidemia. To discover additional PPARα activators as potential compounds for use in hypolipidemic drugs, here we established human hepatoblastoma cell lines with luciferase reporter expression from the promoters containing peroxisome proliferator responsive elements (PPRE) and tetracycline-regulated expression of full-length human PPARα to quantify the effects of chemical ligands on PPARα activity. Using the established cell-based PPARα-activator screening system to screen a library of > 12,000 chemical compounds, we identified several hit compounds with basic chemical skeletons different from those of known PPARα agonists. One of the hit compounds, a 1H-pyrazolo[3,4-b]pyridine-4-carboxylic acid derivative we termed compound 3, selectively up-regulated PPARα transcriptional activity, leading to PPARα target gene expression both in vitro and in vivo. Of note, the half-maximal effective concentrations of the hit compounds were lower than that of the known PPARα ligand fenofibrate. Finally, fenofibrate or compound 3 treatment of high fructose-fed rats having elevated plasma triglyceride levels for 14 days indicated that compound 3 reduces plasma triglyceride levels with similar efficiency as fenofibrate. These observations raise the possibility that 1H-pyrazolo[3,4-b]pyridine-4-carboxylic acid derivatives might be effective drug candidates for selective targeting of PPARα to manage dyslipidemia. Published under license by The American Society for Biochemistry and Molecular Biology, Inc.

Changes in lymphocyte accumulation and proliferation in the lymph nodes draining the pregnant uterus.

PubMed Central

Ansell, J D; McDougall, C M; Speedy, G; Inchley, C J

1978-01-01

Changes in weight, lymphocyte accumulation and cellular proliferation have been measured in the lymph nodes draining the uterus during inter- and intra-strain pregnancies and compared with similar effects after other antigenic stimuli. From the data obtained it was concluded that "paternal" antigenic stimulation from the conceptus initiated an immune response in these nodes. The mechanisms of the subsequent suppression of this response are discussed. PMID:657586

Effect of arachidonic acid metabolites on thymocyte proliferation.

PubMed

Delebassée, S; Gualde, N

1988-01-01

The influences of prostaglandin E2 (PGE2), 15-hydroxyeicosatetraenoic acid (15-HETE) and leukotrienes (LT) on the proliferative response of mature (PNA-) and immature (PNA+) mouse thymocytes was investigated. Both PNA+ and PNA- thymocytes proliferated when cultured with concanavalin A plus interleukin-2. PGE2 in concentrations of 10(-6) to 10(-9) M caused significant inhibition of proliferation of both PNA+ and PNA- thymocytes in these cultures. In contrast, the lipoxygenase products 15-HETE, LTB4, LTC4 and LTD4 caused marked increases in proliferation of PNA+ thymocytes while having no effect on PNA- cells. Therefore, the effect of leukotrienes on thymocyte proliferation depends upon the level of cell maturation and mainly affects immature PNA+ thymocytes.

Inhibition of antigen- and mitogen-induced human lymphocyte proliferation by gold compounds.

PubMed Central

Lipsky, P E; Ziff, M

1977-01-01

Gold sodium thiomalate (GST) inhibited in vitro antigen- and mitogen-triggered human lymphocyte DNA synthesis. Inhibition of responsiveness was observed with concentrations of GST equivalent to gold levels found in serum or tissues of patients receiving chrysotherapy, Inhibition was dependent upon the gold ion itself since GST and gold chloride were both inhibitory whereas thiomalic acid was not. Inhibition could not be explained by nonspecific killing of cells or by an alteration in the kinetics of the responses. GST inhibited mitogen-induced proliferation most effectively when present from the initiation of culture and could not inhibit the responsiveness of cells which previously had been activated by concanvalin A. These findings indicated that GST blocked a critical early step in lymphocyte activation. The degree of GST-induced inhibition of proliferation was increased in cultures of cells partially depleted of monocytes. Moreover, inhibition was reversed by supplementation of these cultures with purified monocytes. These observations suggested that GST blocked thymus-derived (T)-lymphocyte activation by interfering with a requisite function of the monocyte population in initiating such responses. Prolonged incubation of peripheral blood mononuclear cells with GST resulted in diminished mitogen responsiveness upon subsequent culture in the absence of gold. The addition of fresh monocytes restored responsiveness to these populations. Furthermore, preincubation of purified monocytes with GST rendered them deficient in their ability to support mitogen-induced T-lymphocyte proliferation on subsequent culture. These observations indicate that the major effect of GST results from interference with the functional capability of the monocyte population. PMID:838859

Maternal allergic disease does not affect the phenotype of T and B cells or the immune response to allergens in neonates.

PubMed

Rindsjö, E; Joerink, M; Johansson, C; Bremme, K; Malmström, V; Scheynius, A

2010-07-01

It is hypothesized that the in utero environment in allergic mothers can affect the neonatal immune responses. The aim of this study was to analyse the effect of maternal allergic disease on cord blood mononuclear cell (CBMC) phenotype and proliferative responses upon allergen stimulation. Peripheral blood mononuclear cells (PBMC) from 12 allergic and 14 nonallergic mothers and CBMC from their children were analysed. In the mothers, we determined cell proliferation, production of IL-4 and expression of FOXP3 in response to allergen stimulation. In the children, we evaluated cell proliferation and FOXP3 expression following allergen stimulation. Furthermore, expression of different homing markers on T cells and regulatory T cells and maturity of the T cells and B cell subsets were evaluated directly ex vivo. The timothy- and birch-allergic mothers responded with increased proliferation and/or IL-4 production towards timothy and birch extract, respectively, when compared to nonallergic mothers. This could not be explained by impairment of FOXP3(+) regulatory T cells in the allergic mothers. CBMC proliferation and FOXP3 expression in response to allergens were not affected by the allergic status of the mother. Also, phenotype of T cells, FOXP3(+) regulatory T cells and B cells was not affected by the allergic status of the mother. Our results suggest that maternal allergic disease has no effect on the neonatal response to allergens or the phenotype of neonatal lymphocytes. The factors studied here could, however, still affect later development of allergy.

Pyruvate kinase isoform expression alters nucleotide synthesis to impact cell proliferation

PubMed Central

Lunt, Sophia Y.; Muralidhar, Vinayak; Hosios, Aaron M.; Israelsen, William J.; Gui, Dan Y.; Newhouse, Lauren; Ogrodzinski, Martin; Hecht, Vivian; Xu, Kali; Acevedo, Paula N. Marín; Hollern, Daniel P.; Bellinger, Gary; Dayton, Talya L.; Christen, Stefan; Elia, Ilaria; Dinh, Anh T.; Stephanopoulos, Gregory; Manalis, Scott R.; Yaffe, Michael B.; Andrechek, Eran R.; Fendt, Sarah-Maria; Heiden, Matthew G. Vander

2014-01-01

SUMMARY Metabolic regulation influences cell proliferation. The influence of pyruvate kinase isoforms on tumor cells has been extensively studied, but whether PKM2 is required for normal cell proliferation is unknown. We examine how PKM2-deletion affects proliferation and metabolism in non-transformed, non-immortalized PKM2-expressing primary cells. We find that deletion of PKM2 in primary cells results in PKM1 expression and proliferation arrest. PKM1 expression, rather than PKM2 loss, is responsible for this effect, and proliferation arrest cannot be explained by cell differentiation, senescence, death, changes in gene expression, or prevention of cell growth. Instead, PKM1 expression impairs nucleotide production and the ability to synthesize DNA and progress through the cell cycle. Nucleotide biosynthesis is limiting, as proliferation arrest is characterized by severe thymidine depletion, and supplying exogenous thymine rescues both nucleotide levels and cell proliferation. Thus, PKM1 expression promotes a metabolic state that is unable to support DNA synthesis. PMID:25482511

Molecular Determinants of Magnolol Targeting Both RXRα and PPARγ

PubMed Central

Chen, Lili; Chen, Jing; Hu, Lihong; Jiang, Hualiang; Shen, Xu

2011-01-01

Nuclear receptors retinoic X receptor α (RXRα) and peroxisome proliferator activated receptor γ (PPARγ) function potently in metabolic diseases, and are both important targets for anti-diabetic drugs. Coactivation of RXRα and PPARγ is believed to synergize their effects on glucose and lipid metabolism. Here we identify the natural product magnolol as a dual agonist targeting both RXRα and PPARγ. Magnolol was previously reported to enhance adipocyte differentiation and glucose uptake, ameliorate blood glucose level and prevent development of diabetic nephropathy. Although magnolol can bind and activate both of these two nuclear receptors, the transactivation assays indicate that magnolol exhibits biased agonism on the transcription of PPAR-response element (PPRE) mediated by RXRα:PPARγ heterodimer, instead of RXR-response element (RXRE) mediated by RXRα:RXRα homodimer. To further elucidate the molecular basis for magnolol agonism, we determine both the co-crystal structures of RXRα and PPARγ ligand-binding domains (LBDs) with magnolol. Structural analyses reveal that magnolol adopts its two 5-allyl-2-hydroxyphenyl moieties occupying the acidic and hydrophobic cavities of RXRα L-shaped ligand-binding pocket, respectively. While, two magnolol molecules cooperatively accommodate into PPARγ Y-shaped ligand-binding pocket. Based on these two complex structures, the key interactions for magnolol activating RXRα and PPARγ are determined. As the first report on the dual agonist targeting RXRα and PPARγ with receptor-ligand complex structures, our results are thus expected to help inspect the potential pharmacological mechanism for magnolol functions, and supply useful hits for nuclear receptor multi-target ligand design. PMID:22140563

cAMP-response-element-binding protein positively regulates breast cancer metastasis and subsequent bone destruction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Son, Jieun; Lee, Jong-Ho; Kim, Ha-Neui

2010-07-23

Research highlights: {yields} CREB is highly expressed in advanced breast cancer cells. {yields} Tumor-related factors such as TGF-{beta} further elevate CREB expression. {yields} CREB upregulation stimulates metastatic potential of breast cancer cells. {yields} CREB signaling is required for breast cancer-induced bone destruction. -- Abstract: cAMP-response-element-binding protein (CREB) signaling has been reported to be associated with cancer development and poor clinical outcome in various types of cancer. However, it remains to be elucidated whether CREB is involved in breast cancer development and osteotropism. Here, we found that metastatic MDA-MB-231 breast cancer cells exhibited higher CREB expression than did non-metastatic MCF-7 cellsmore » and that CREB expression was further increased by several soluble factors linked to cancer progression, such as IL-1, IGF-1, and TGF-{beta}. Using wild-type CREB and a dominant-negative form (K-CREB), we found that CREB signaling positively regulated the proliferation, migration, and invasion of MDA-MB-231 cells. In addition, K-CREB prevented MDA-MB-231 cell-induced osteolytic lesions in a mouse model of cancer metastasis. Furthermore, CREB signaling in cancer cells regulated the gene expression of PTHrP, MMPs, and OPG, which are closely involved in cancer metastasis and bone destruction. These results indicate that breast cancer cells acquire CREB overexpression during their development and that this CREB upregulation plays an important role in multiple steps of breast cancer bone metastasis.« less

PPARs and the Cardiovascular System

PubMed Central

Hamblin, Milton; Chang, Lin; Fan, Yanbo; Zhang, Jifeng

2009-01-01

Abstract Peroxisome proliferator-activated receptors (PPARs) belong to the nuclear hormone-receptor superfamily. Originally cloned in 1990, PPARs were found to be mediators of pharmacologic agents that induce hepatocyte peroxisome proliferation. PPARs also are expressed in cells of the cardiovascular system. PPARγ appears to be highly expressed during atherosclerotic lesion formation, suggesting that increased PPARγ expression may be a vascular compensatory response. Also, ligand-activated PPARγ decreases the inflammatory response in cardiovascular cells, particularly in endothelial cells. PPARα, similar to PPARγ, also has pleiotropic effects in the cardiovascular system, including antiinflammatory and antiatherosclerotic properties. PPARα activation inhibits vascular smooth muscle proinflammatory responses, attenuating the development of atherosclerosis. However, PPARδ overexpression may lead to elevated macrophage inflammation and atherosclerosis. Conversely, PPARδ ligands are shown to attenuate the pathogenesis of atherosclerosis by improving endothelial cell proliferation and survival while decreasing endothelial cell inflammation and vascular smooth muscle cell proliferation. Furthermore, the administration of PPAR ligands in the form of TZDs and fibrates has been disappointing in terms of markedly reducing cardiovascular events in the clinical setting. Therefore, a better understanding of PPAR-dependent and -independent signaling will provide the foundation for future research on the role of PPARs in human cardiovascular biology. Antioxid. Redox Signal. 11, 1415–1452. PMID:19061437

Effect of Water-Glass Coating on HA and HA-TCP Samples for MSCs Adhesion, Proliferation, and Differentiation.

PubMed

Bajpai, Indu; Kim, Duk Yeon; Kyong-Jin, Jung; Song, In-Hwan; Kim, Sukyoung

2016-01-01

Ca-P and silicon based materials have become very popular as bone tissue engineering materials. In this study, water-glass (also known as sodium silicate glass) was coated on sintered hydroxyapatite (HA) and HA-TCP (TCP stands for tricalcium phosphate) samples and subsequently heat-treated at 600°C for 2 hrs. X-rays diffraction showed the presence of β- and α-TCP phases along with HA in the HA-TCP samples. Samples without coating, with water-glass coating, and heat-treated after water-glass coating were used to observe the adhesion and proliferation response of bone marrow derived-mesenchymal stem cells (MSCs). Cell culture was carried out for 4 hrs, 1 day, and 7 days. Interestingly, all samples showed similar response for cell adhesion and proliferation up to 7-day culture but fibronectin, E-cadherin, and osteogenic differentiation related genes (osteocalcin and osteopontin) were significantly induced in heat-treated water-glass coated HA-TCP samples. A water-glass coating on Ca-P samples was not found to influence the cell proliferation response significantly but activated some extracellular matrix genes and induced osteogenic differentiation in the MSCs.

X-linked recessive primary retinal dysplasia is linked to the Norrie disease locus.

PubMed

Ravia, Y; Braier-Goldstein, O; Bat-Miriam, K M; Erlich, S; Barkai, G; Goldman, B

1993-08-01

X-linked primary retinal dysplasia (PRD) refers to an abnormal proliferation of retinal tissue causing either its neural elements or its glial tissue to form folds, giving rise to gliosis. A Jewish family of oriental origin was previously reported by Godel and Goodman, in which a total of five males suffer from different degrees of blindness. The authors postulated that the described findings are distinguished from Norrie disease, since in this case no clinical findings, other than those associated with the eyes, were noticed in the affected males. In addition, two of the carrier females exhibit minimal eye changes. We have performed linkage analysis of the family using the L1.28, p58-1 and m27 beta probes, and DXS426 and MAOB associated microsatellites. Our results map the gene responsible for the disorder between the MAOB and DXS426, m27 beta and p58-1 loci, on the short arm of the X chromosome at Xp11.3, which suggest the possibility that the same gene is responsible for both primary retinal dysplasia and Norrie disease.

Amitriptyline induces early growth response-1 gene expression via ERK and JNK mitogen-activated protein kinase pathways in rat C6 glial cells.

PubMed

Chung, Eun Young; Shin, Soon Young; Lee, Young Han

2007-07-05

Astrocytes play important roles in guiding the construction of the nervous system, controlling extracellular ions and neurotransmitters, and regulating CNS synaptogenesis. Egr-1 is a transcription factor involved in neuronal differentiation and astrocyte cell proliferation. In this study, we investigated whether the tricyclic antidepressant (TCA) amitriptyline induces Egr-1 expression in astrocytes using rat C6 glioma cells as a model. We found that amitriptyline increased the expression of Egr-1 in a dose- and time-dependent manner. The amitriptyline-induced Egr-1 expression was mediated through serum response elements (SREs) in the Egr-1 promoter. SREs were activated by the Ets-domain transcription factor Elk-1 through the ERK and JNK mitogen-activated protein (MAP) kinase pathways. The inhibition of the ERK and JNK MAP kinase signals attenuated amitriptyline-induced transactivation of Gal4-Elk-1 and Egr-1 promoter activity. Our findings suggest that the induction of Egr-1 expression in astrocytes may be required to attain the therapeutic effects of antidepressant drugs.

Custom-designed proteins as novel therapeutic tools? The case of arrestins

PubMed Central

Gurevich, Vsevolod V.; Gurevich, Eugenia V.

2010-01-01

Multiple genetic disorders can be associated with excessive signalling by mutant G-protein-coupled receptors (GPCRs) that are either constitutively active or have lost sites where phosphorylation by GPCR kinases is necessary for desensitisation by cognate arrestins. Phosphorylation-independent arrestin1 can compensate for defects in phosphorylation of the GPCR rhodopsin in retinal rod cells, facilitating recovery, improving light responsiveness, and promoting photoreceptor survival. These proof-of-principle experiments show that, based on mechanistic understanding of the inner workings of a protein, one can modify its functional characteristics to generate custom-designed mutants that improve the balance of signalling in congenital and acquired disorders. Manipulations of arrestin elements responsible for scaffolding mitogen-activated protein kinase cascades and binding other signalling proteins involved in life-or-death decisions in the cell are likely to yield mutants that affect cell survival and proliferation in the desired direction. Although this approach is still in its infancy, targeted redesign of individual functions of many proteins offers a promise of a completely new therapeutic toolbox with huge potential. PMID:20412604

Multiple anticancer activities of EF24, a novel curcumin analog, on human ovarian carcinoma cells.

PubMed

Tan, Xin; Sidell, Neil; Mancini, Alessandra; Huang, Ruo-Pan; Shenming Wang; Horowitz, Ira R; Liotta, Dennis C; Taylor, Robert N; Wieser, Friedrich

2010-10-01

Curcumin, a component of turmeric, has been reported to exhibit potential antitumor activities. This study assessed the effects of a novel synthetic curcumin analog, EF24, on proliferation, apoptosis, and vascular endothelial growth factor (VEGF) regulation in platinum-sensitive (IGROV1) and platinum-resistant (SK-OV-3) human ovarian cancer cells. EF24 time- and dose-dependently suppressed the growth of both cell lines and synergized with cisplatin to induce apoptosis. Although treatment with EF24 had no significant effect on VEGF messenger RNA (mRNA) expression,VEGF protein secretion into conditioned media was dose-dependently reduced with EF24 demonstrating ∼8-fold greater potency than curcumin (P < .05). EF24 significantly inhibited hydrogen peroxide (H(2)O(2))-induced VEGF expression, as did the phenolic antioxidant tert-butylhydroquinone (t-BHQ). EF24 upregulated cellular antioxidant responses as observed by the suppression of reactive oxygen species (ROS) generation and activation of antioxidant response element (ARE)-dependent gene transcription. Given its high potency, EF24 is an excellent lead candidate for further development as an adjuvant therapeutic agent in preclinical models of ovarian cancer.

Persistence of T-cell immune response induced by two acellular pertussis vaccines in children five years after primary vaccination.

PubMed

Palazzo, Raffaella; Carollo, Maria; Bianco, Manuela; Fedele, Giorgio; Schiavoni, Ilaria; Pandolfi, Elisabetta; Villani, Alberto; Tozzi, Alberto E; Mascart, Françoise; Ausiello, Clara M

2016-01-01

The resurgence of pertussis suggests the need for greater efforts to understand the long-lasting protective responses induced by vaccination. In this paper we dissect the persistence of T memory responses induced by primary vaccination with two different acellular pertussis (aP) vaccines, hexavalent Hexavac® vaccine (Hexavac) (Sanofi Pasteur MSD) and Infanrix hexa® (Infanrix) (Glaxo-SmithKline Biologicals). We evaluated magnitude and duration of T-cell responses to pertussis toxin (PT) by measuring T-cell proliferation, cytokines (IL-2 and IFNγ) production and memory subsets in two groups of children 5 years after primary vaccination. Some of the enrolled children received only primary vaccination, while others had the pre-school boost dose. Positive T-cell responses to PT were detected in 36% of children. Percentage of responsive children, T-cell proliferation and CD4IL-2+ cells were significantly higher in the children primed with Hexavac than in those who received Infanrix vaccine. No major effects of the boost on PT-specific proliferation were observed. Overall, our data documented a persistence of T-cell memory against PT in a minor fraction of children 5 years after primary vaccination. The different responses induced by Hexavac and Infanrix vaccine could rely on differences in PT inactivation process or excipients/adjuvants formulations.

Effect of the feeding system on the fatty acid composition, expression of the Δ9-desaturase, Peroxisome Proliferator-Activated Receptor Alpha, Gamma, and Sterol Regulatory Element Binding Protein 1 genes in the semitendinous muscle of light lambs of the Rasa Aragonesa breed

PubMed Central

2010-01-01

Background Conjugated linoleic acids (CLAs) are receiving increasing attention because of their beneficial effects on human health, with milk and meat products derived from ruminants as important sources of CLA in the human diet. SCD gene is responsible for some of the variation in CLA concentration in adipose tissues, and PPARγ, PPARα and SREBP1 genes are regulator of SCD gene. The aim of this work was to evaluate the effect of the feeding system on fatty acid composition, CLA content and relative gene expression of Δ9-desaturase (SCD), Peroxisome Proliferator-Activated Receptor Gamma (PPARγ), Peroxisome Proliferator-Activated Receptor Alpha, (PPARα) and Sterol Regulatory Element Binding Protein (SREBP1) in Rasa Aragonesa light lambs in semitendinous muscle. Forty-four single-born male lambs were used to evaluate the effect of the feeding system, varying on an intensity gradient according to the use of concentrates: 1. grazing alfalfa, 2. grazing alfalfa with a supplement for lambs, 3. indoor lambs with grazing ewes and 4. drylot. Results Both grazing systems resulted in a higher concentration of vaccenic acid (VA), CLA, CLA/VA acid ratio, and a lower oleic content, oleic acid (C18:1)/stearic acid (C18:0) ratio, PUFA n-6/n-3 ratio and SCD expression compared to other diets. In addition feeding system affected the fatty acid composition and SCD expression, possibly due to CLA concentration or the PUFA n-6/n-3 ratio. Both expression of the SCD gene and the feeding system were important factors affecting CLA concentration in the animal's semitendinous muscle. PPARγ, PPARα and SREBP1 expression seemed to be unaffected by the feeding system. Although no significant results were found, PPARγ, PPARα and SREBP1 showed similar expression pattern as SCD. Moreover, the correlation results between SCD expression and PPARγ (p < 0.01), as well as SREBP1 (p < 0.01) expression, may suggest that these genes were affecting SCD expression in a different way. Conclusions The data indicated that the feeding system is the main factor affecting the fatty acid composition and SCD gene expression, which is also affected by CLA and possibly by n-6/n-3 PUFAs. PMID:20649987

Cytokine Production but Lack of Proliferation in Peripheral Blood Mononuclear Cells from Chronic Chagas' Disease Cardiomyopathy Patients in Response to T. cruzi Ribosomal P Proteins

PubMed Central

Longhi, Silvia A.; Atienza, Augusto; Perez Prados, Graciela; Buying, Alcinette; Balouz, Virginia; Buscaglia, Carlos A.; Santos, Radleigh; Tasso, Laura M.; Bonato, Ricardo; Chiale, Pablo; Gómez, Karina A.

2014-01-01

Background Trypanosoma cruzi ribosomal P proteins, P2β and P0, induce high levels of antibodies in patients with chronic Chagas' disease Cardiomyopathy (CCC). It is well known that these antibodies alter the beating rate of cardiomyocytes and provoke apoptosis by their interaction with β1-adrenergic and M2-muscarinic cardiac receptors. Based on these findings, we decided to study the cellular immune response to these proteins in CCC patients compared to non-infected individuals. Methodology/Principal findings We evaluated proliferation, presence of surface activation markers and cytokine production in peripheral blood mononuclear cells (PBMC) stimulated with P2β, the C-terminal portion of P0 (CP0) proteins and T. cruzi lysate from CCC patients predominantly infected with TcVI lineage. PBMC from CCC patients cultured with P2β or CP0 proteins, failed to proliferate and express CD25 and HLA-DR on T cell populations. However, multiplex cytokine assays showed that these antigens triggered higher secretion of IL-10, TNF-α and GM-CSF by PBMC as well as both CD4+ and CD8+ T cells subsets of CCC subjects. Upon T. cruzi lysate stimulation, PBMC from CCC patients not only proliferated but also became activated within the context of Th1 response. Interestingly, T. cruzi lysate was also able to induce the secretion of GM-CSF by CD4+ or CD8+ T cells. Conclusions/Significance Our results showed that although the lack of PBMC proliferation in CCC patients in response to ribosomal P proteins, the detection of IL-10, TNF-α and GM-CSF suggests that specific T cells could have both immunoregulatory and pro-inflammatory potential, which might modulate the immune response in Chagas' disease. Furthermore, it was possible to demonstrate for the first time that GM-CSF was produced by PBMC of CCC patients in response not only to recombinant ribosomal P proteins but also to parasite lysate, suggesting the value of this cytokine to evaluate T cells responses in T. cruzi infection. PMID:24901991

Scaffold architecture and fibrin gels promote meniscal cell proliferation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pawelec, K. M., E-mail: pawelec.km@gmail.com, E-mail: jw626@cam.ac.uk; Best, S. M.; Cameron, R. E.

2015-01-01

Stability of the knee relies on the meniscus, a complex connective tissue with poor healing ability. Current meniscal tissue engineering is inadequate, as the signals for increasing meniscal cell proliferation have not been established. In this study, collagen scaffold structure, isotropic or aligned, and fibrin gel addition were tested. Metabolic activity was promoted by fibrin addition. Cellular proliferation, however, was significantly increased by both aligned architectures and fibrin addition. None of the constructs impaired collagen type I production or triggered adverse inflammatory responses. It was demonstrated that both fibrin gel addition and optimized scaffold architecture effectively promote meniscal cell proliferation.

Transforming growth factor β suppresses peroxisome proliferator-activated receptor γ expression via both SMAD binding and novel TGF-β inhibitory elements.

PubMed

Lakshmi, Sowmya P; Reddy, Aravind T; Reddy, Raju C

2017-04-24

Transforming growth factor β (TGF-β) contributes to wound healing and, when dysregulated, to pathological fibrosis. TGF-β and the anti-fibrotic nuclear hormone receptor peroxisome proliferator-activated receptor γ (PPARγ) repress each other's expression, and such PPARγ down-regulation is prominent in fibrosis and mediated, via previously unknown SMAD-signaling mechanisms. Here, we show that TGF-β induces the association of SMAD3 with both SMAD4, needed for translocation of the complex into the nucleus, and the essential context-sensitive co-repressors E2F4 and p107. The complex mediates TGF-β-induced repression by binding to regulatory elements in the target promoter. In the PPARG promoter, we found that the SMAD3-SMAD4 complex binds both to a previously unknown consensus TGF-β inhibitory element (TIE) and also to canonical SMAD-binding elements (SBEs). Furthermore, the TIE and SBEs independently mediated the partial repression of PPARG transcription, the first demonstration of a TIE and SBEs functioning within the same promoter. Also, TGF-β-treated fibroblasts contained SMAD complexes that activated a SMAD target gene in addition to those repressing PPARG transcription, the first finding of such dual activity within the same cell. These findings describe in detail novel mechanisms by which TGF-β represses PPARG transcription, thereby facilitating its own pro-fibrotic activity. © 2017 The Author(s); published by Portland Press Limited on behalf of the Biochemical Society.

The Effects of Cocaine and Stress on Lymphocyte Proliferation in Rats

DTIC Science & Technology

1993-02-22

indices of immune function while decreasing others. Bagarasa and Forman (1989) found that intraperitoneal cocaine (1 . 25, 2.5 mg/kg-10 days) at low ... doses caused an 3 increase in PFC response in male Fisher rats, but at higher doses (5 rng/kg-lO days) PFC response was suppressed. Analysis of...found that cocaine combined with Con A in vitro suppressed lymphocyte proliferation in a dose ~ dependent fashion for mice splenocytes and human

Polycomb Repressive Complex 2 Confers BRG1 Dependency on the CIITA Locus.

PubMed

Abou El Hassan, Mohamed; Yu, Tao; Song, Lan; Bremner, Rod

2015-05-15

CIITA (or MHC2TA) coordinates constitutive and IFN-γ-induced expression of MHC class II genes. IFN-γ responsiveness of CIITA requires BRG1 (SMARCA4), the ATPase engine of the chromatin remodeling SWI/SNF complex (also called BAF). SWI/SNF is defective in many human cancers, providing a mechanism to explain IFN-γ resistance. BRG1 dependency is mediated through remote elements. Short CIITA reporters lacking these elements respond to IFN-γ, even in BRG1-deficient cells, suggesting that BRG1 counters a remote repressive influence. The nature of this distal repressor is unknown, but it would represent a valuable therapeutic target to reactivate IFN-γ responsiveness in cancer. In this article, we show that the polycomb repressive complex 2 (PRC2) components EZH2 and SUZ12, as well as the associated histone mark H3K27me3, are codetected at interenhancer regions across the CIITA locus. IFN-γ caused a BRG1-dependent reduction in H3K27me3, associated with nucleosome displacement. SUZ12 knockdown restored IFN-γ responsiveness in BRG1-null cells, and it mimicked the ability of BRG1 to induce active histone modifications (H3K27ac, H3K4me) at the -50-kb enhancer. Thus, PRC2 confers BRG1 dependency on the CIITA locus. Our data suggest that, in addition to its known roles in promoting stemness and proliferation, PRC2 may inhibit immune surveillance, and it could be targeted to reactivate CIITA expression in SWI/SNF deficient cancers. Copyright © 2015 by The American Association of Immunologists, Inc.

The BTB and CNC homology 1 (BACH1) target genes are involved in the oxidative stress response and in control of the cell cycle.

PubMed

Warnatz, Hans-Jörg; Schmidt, Dominic; Manke, Thomas; Piccini, Ilaria; Sultan, Marc; Borodina, Tatiana; Balzereit, Daniela; Wruck, Wasco; Soldatov, Alexey; Vingron, Martin; Lehrach, Hans; Yaspo, Marie-Laure

2011-07-01

The regulation of gene expression in response to environmental signals and metabolic imbalances is a key step in maintaining cellular homeostasis. BTB and CNC homology 1 (BACH1) is a heme-binding transcription factor repressing the transcription from a subset of MAF recognition elements at low intracellular heme levels. Upon heme binding, BACH1 is released from the MAF recognition elements, resulting in increased expression of antioxidant response genes. To systematically address the gene regulatory networks involving BACH1, we combined chromatin immunoprecipitation sequencing analysis of BACH1 target genes in HEK 293 cells with knockdown of BACH1 using three independent types of small interfering RNAs followed by transcriptome profiling using microarrays. The 59 BACH1 target genes identified by chromatin immunoprecipitation sequencing were found highly enriched in genes showing expression changes after BACH1 knockdown, demonstrating the impact of BACH1 repression on transcription. In addition to known and new BACH1 targets involved in heme degradation (HMOX1, FTL, FTH1, ME1, and SLC48A1) and redox regulation (GCLC, GCLM, and SLC7A11), we also discovered BACH1 target genes affecting cell cycle and apoptosis pathways (ITPR2, CALM1, SQSTM1, TFE3, EWSR1, CDK6, BCL2L11, and MAFG) as well as subcellular transport processes (CLSTN1, PSAP, MAPT, and vault RNA). The newly identified impact of BACH1 on genes involved in neurodegenerative processes and proliferation provides an interesting basis for future dissection of BACH1-mediated gene repression in neurodegeneration and virus-induced cancerogenesis.

Isoniazid suppresses antioxidant response element activities and impairs adipogenesis in mouse and human preadipocytes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Yanyan; The First Affiliated Hospital, China Medical University, Shenyang 110001; Xue, Peng

2013-12-15

Transcriptional signaling through the antioxidant response element (ARE), orchestrated by the Nuclear factor E2-related factor 2 (Nrf2), is a major cellular defense mechanism against oxidative or electrophilic stress. Here, we reported that isoniazid (INH), a widely used antitubercular drug, displays a substantial inhibitory property against ARE activities in diverse mouse and human cells. In 3T3-L1 preadipocytes, INH concentration-dependently suppressed the ARE-luciferase reporter activity and mRNA expression of various ARE-dependent antioxidant genes under basal and oxidative stressed conditions. In keeping with our previous findings that Nrf2-ARE plays a critical role in adipogenesis by regulating expression of CCAAT/enhancer-binding protein β (C/EBPβ) andmore » peroxisome proliferator-activated receptor γ (PPARγ), suppression of ARE signaling by INH hampered adipogenic differentiation of 3T3-L1 cells and human adipose-derived stem cells (ADSCs). Following adipogenesis induced by hormonal cocktails, INH-treated 3T3-L1 cells and ADSCs displayed significantly reduced levels of lipid accumulation and attenuated expression of C/EBPα and PPARγ. Time-course studies in 3T3-L1 cells revealed that inhibition of adipogenesis by INH occurred in the early stage of terminal adipogenic differentiation, where reduced expression of C/EBPβ and C/EBPδ was observed. To our knowledge, the present study is the first to demonstrate that INH suppresses ARE signaling and interrupts with the transcriptional network of adipogenesis, leading to impaired adipogenic differentiation. The inhibition of ARE signaling may be a potential underlying mechanism by which INH attenuates cellular antioxidant response contributing to various complications. - Highlights: • Isoniazid suppresses ARE-mediated transcriptional activity. • Isoniazid inhibits adipogenesis in preadipocytes. • Isoniazid suppresses adipogenic gene expression during adipogenesis.« less

Hydrogel microstructure live-cell array for multiplexed analyses of cancer stem cells, tumor heterogeneity and differential drug response at single-element resolution.

PubMed

Afrimzon, E; Botchkina, G; Zurgil, N; Shafran, Y; Sobolev, M; Moshkov, S; Ravid-Hermesh, O; Ojima, I; Deutsch, M

2016-03-21

Specific phenotypic subpopulations of cancer stem cells (CSCs) are responsible for tumor development, production of heterogeneous differentiated tumor mass, metastasis, and resistance to therapies. The development of therapeutic approaches based on targeting rare CSCs has been limited partially due to the lack of appropriate experimental models and measurement approaches. The current study presents new tools and methodologies based on a hydrogel microstructure array (HMA) for identification and multiplex analyses of CSCs. Low-melt agarose integrated with type I collagen, a major component of the extracellular matrix (ECM), was used to form a solid hydrogel array with natural non-adhesive characteristics and high optical quality. The array contained thousands of individual pyramidal shaped, nanoliter-volume micro-chambers (MCs), allowing concomitant generation and measurement of large populations of free-floating CSC spheroids from single cells, each in an individual micro-chamber (MC). The optical live cell platform, based on an imaging plate patterned with HMA, was validated using CSC-enriched prostate and colon cancer cell lines. The HMA methodology and quantitative image analysis at single-element resolution clearly demonstrates several levels of tumor cell heterogeneity, including morphological and phenotypic variability, differences in proliferation capacity and in drug response. Moreover, the system facilitates real-time examination of single stem cell (SC) fate, as well as drug-induced alteration in expression of stemness markers. The technology may be applicable in personalized cancer treatment, including multiplex ex vivo analysis of heterogeneous patient-derived tumor specimens, precise detection and characterization of potentially dangerous cell phenotypes, and for representative evaluation of drug sensitivity of CSCs and other types of tumor cells.

Effect of activated autologous platelet-rich plasma on proliferation and osteogenic differentiation of human adipose-derived stem cells in vitro

PubMed Central

Xu, Fang-Tian; Li, Hong-Mian; Yin, Qing-Shui; Liang, Zhi-Jie; Huang, Min-Hong; Chi, Guang-Yi; Huang, Lu; Liu, Da-Lie; Nan, Hua

2015-01-01

To investigate whether activated autologous platelet-rich plasma (PRP) can promote proliferation and osteogenic differentiation of human adipose-derived stem cells (hASCs) in vitro. hASCs were isolated from lipo-aspirates, and characterized by specific cell markers and multilineage differentiation capacity after culturing to the 3rd passage. PRP was collected and activated from human peripheral blood of the same patient. Cultured hASCs were treated with normal osteogenic inductive media alone (group A, control) or osteogenic inductive media plus 5%, 10%, 20%, 40%PRP (group B, C, D, E, respectively). Cell proliferation was assessed by CCK-8 assay. mRNA expression of osteogenic marker genes including alkaline phosphatase (ALP), osteopontin (OPN), osteocalcin (OCN) and core binding factor alpha 1 (Cbfa1) were determined by Real-Time Quantitative PCR Analysis (qPCR). Data revealed that different concentrations of activated autologous PRP significantly promoted hASCs growth in the proliferation phase compared to the without PRP group and resulted in a dose-response relationship. At 7-d and 14-d time point of the osteogenic induced stage, ALP activity in PRP groups gradually increased with the increasing of concentrations of PRP and showed that dose-response relationship. At 21-d time point of the osteogenic induced stage, PRP groups make much more mineralization and mRNA relative expression of ALP, OPN, OCN and Cbfa1 than that without PRP groups and show that dose-response relationship. This study indicated that different concentrations of activated autologous PRP can promote cell proliferation at earlier stage and promote osteogenic differentiation at later stage of hASCs in vitro. Moreover, it displayed a dose-dependent effect of activated autologous PRP on cell proliferation and osteogenic differentiation of hASCs in vitro. PMID:25901195

Leptin sustains spontaneous remyelination in the adult central nervous system

PubMed Central

Matoba, Ken; Muramatsu, Rieko; Yamashita, Toshihide

2017-01-01

Demyelination is a common feature of many central nervous system (CNS) diseases and is associated with neurological impairment. Demyelinated axons are spontaneously remyelinated depending on oligodendrocyte development, which mainly involves molecules expressed in the CNS environment. In this study, we found that leptin, a peripheral hormone secreted from adipocytes, promoted the proliferation of oligodendrocyte precursor cells (OPCs). Leptin increased the OPC proliferation via in vitro phosphorylation of extracellular signal regulated kinase (ERK); whereas leptin neutralization inhibited OPC proliferation and remyelination in a mouse model of toxin-induced demyelination. The OPC-specific leptin receptor long isoform (LepRb) deletion in mice inhibited both OPC proliferation and remyelination in the response to demyelination. Intrathecal leptin administration increased OPC proliferation. These results demonstrated a novel molecular mechanism by which leptin sustained OPC proliferation and remyelination in a pathological CNS. PMID:28091609

Lithium doped calcium phosphate cement maintains physical mechanical properties and promotes osteoblast proliferation and differentiation.

PubMed

Li, Li; Wang, Renchong; Li, Baichuan; Liang, Wei; Pan, Haobo; Cui, Xu; Tang, Jingli; Li, Bing

2017-07-01

Calcium phosphate cement (CPC) has been widely used in bone tissue repairing due to its physical mechanical properties and biocompatibility. Addition of trace element to CPC has shown promising evidence to improve the physical properties and biological activities of CPC. Lithium (Li) has effect on osteoblast proliferation and differentiation. In this study, we incorporated Li to CPC and examined the physical properties of Li/CPC and its effect on osteoblast proliferation and differentiation. We found that Li doped CPC maintained similar setting time, pore size distribution, compressive strength, composition, and morphology as CPC without Li. Additionally, Li doped CPC improved osteoblast proliferation and differentiation significantly compared to CPC without Li. To our knowledge, our results, for the first time, show that Li doped CPC has beneficial effect on osteoblast in cell culture while keeps the excellent physical-mechanical properties of CPC. This study will lead to potential application of Li doped CPC in bone tissue engineering. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 944-952, 2017. © 2016 Wiley Periodicals, Inc.

Protease Activated Receptor-2 Expression and Function in Asthmatic Bronchial Smooth Muscle

PubMed Central

Gilbert, Guillaume; Carvalho, Gabrielle; Trian, Thomas; Ozier, Annaig; Gillibert-Duplantier, Jennifer; Ousova, Olga; Maurat, Elise; Thumerel, Matthieu; Quignard, Jean-François; Girodet, Pierre-Olivier; Marthan, Roger; Berger, Patrick

2014-01-01

Asthmatic bronchial smooth muscle (BSM) is characterized by structural remodeling associated with mast cell infiltration displaying features of chronic degranulation. Mast cell-derived tryptase can activate protease activated receptor type-2 (PAR-2) of BSM cells. The aims of the present study were (i) to evaluate the expression of PAR-2 in both asthmatic and non asthmatic BSM cells and, (ii) to analyze the effect of prolonged stimulation of PAR-2 in asthmatic BSM cells on cell signaling and proliferation. BSM cells were obtained from both 33 control subjects and 22 asthmatic patients. PAR-2 expression was assessed by flow cytometry, western blot and quantitative RT-PCR. Calcium response, transduction pathways and proliferation were evaluated before and following PAR-2 stimulation by SLIGKV-NH2 or trypsin for 1 to 3 days. Asthmatic BSM cells expressed higher basal levels of functional PAR-2 compared to controls in terms of mRNA, protein expression and calcium response. When PAR-2 expression was increased by means of lentivirus in control BSM cells to a level similar to that of asthmatic cells, PAR-2-induced calcium response was then similar in both types of cell. However, repeated PAR-2 stimulations increased the proliferation of asthmatic BSM cells but not that of control BSM cells even following lentiviral over-expression of PAR-2. Such an increased proliferation was related to an increased phosphorylation of ERK in asthmatic BSM cells. In conclusion, we have demonstrated that asthmatic BSM cells express increased baseline levels of functional PAR-2. This higher basal level of PAR-2 accounts for the increased calcium response to PAR-2 stimulation, whereas the increased proliferation to repeated PAR-2 stimulation is related to increased ERK phosphorylation. PMID:24551046

GW501516-activated PPARβ/δ promotes liver fibrosis via p38-JNK MAPK-induced hepatic stellate cell proliferation.

PubMed

Kostadinova, Radina; Montagner, Alexandra; Gouranton, Erwan; Fleury, Sébastien; Guillou, Hervé; Dombrowicz, David; Desreumaux, Pierre; Wahli, Walter

2012-10-10

After liver injury, the repair process comprises activation and proliferation of hepatic stellate cells (HSCs), which produce extracellular matrix (ECM) proteins. Peroxisome proliferator-activated receptor beta/delta (PPARβ/δ) is highly expressed in these cells, but its function in liver repair remains incompletely understood. This study investigated whether activation of PPARβ/δ with the ligand GW501516 influenced the fibrotic response to injury from chronic carbon tetrachloride (CCl4) treatment in mice. Wild type and PPARβ/δ-null mice were treated with CCl4 alone or CCl4 co-administered with GW501516. To unveil mechanisms underlying the PPARβ/δ-dependent effects, we analyzed the proliferative response of human LX-2 HSCs to GW501516 in the presence or absence of PPARβ/δ. We found that GW501516 treatment enhanced the fibrotic response. Compared to the other experimental groups, CCl4/GW501516-treated wild type mice exhibited increased expression of various profibrotic and pro-inflammatory genes, such as those involved in extracellular matrix deposition and macrophage recruitment. Importantly, compared to healthy liver, hepatic fibrotic tissues from alcoholic patients showed increased expression of several PPAR target genes, including phosphoinositide-dependent kinase-1, transforming growth factor beta-1, and monocyte chemoattractant protein-1. GW501516 stimulated HSC proliferation that caused enhanced fibrotic and inflammatory responses, by increasing the phosphorylation of p38 and c-Jun N-terminal kinases through the phosphoinositide-3 kinase/protein kinase-C alpha/beta mixed lineage kinase-3 pathway. This study clarified the mechanism underlying GW501516-dependent promotion of hepatic repair by stimulating proliferation of HSCs via the p38 and JNK MAPK pathways.

Pirfenidone Inhibits T Cell Activation, Proliferation, Cytokine and Chemokine Production, and Host Alloresponses

PubMed Central

Visner, Gary A.; Liu, Fengzhi; Bizargity, Peyman; Liu, Hanzhong; Liu, Kaifeng; Yang, Jun; Wang, Liqing; Hancock, Wayne W.

2009-01-01

Background We previously showed that pirfenidone, an anti-fibrotic agent, reduces lung allograft injury/rejection. In this study, we tested the hypothesis that pirfenidone has immune modulating activities and evaluated its effects on the function of T cell subsets, which play important roles in allograft rejection. Method We first evaluated whether pirfenidone alters T cell proliferation and cytokine release in response to T cell receptor (TCR) activation, and whether pirfenidone alters regulatory T cells (CD4+CD25+) suppressive effects using an in vitro assay. Additionally, pirfenidone effects on alloantigen-induced T cell proliferation in vivo were assessed by adoptive transfer of CFSE-labeled T cells across a parent->F1 MHC mismatch, as well as using a murine heterotopic cardiac allograft model (BALB/c->C57BL/6). Results Pirfenidone was found to inhibit the responder frequency of TCR-stimulated CD4+ cell total proliferation in vitro and in vivo, whereas both CD4 and CD8 proliferation index were reduced by pirfenidone. Additionally, pirfenidone inhibited TCR-induced production of multiple pro-inflammatory cytokines and chemokines. Interestingly, there was no change on TGF-β production by purified T cells, and pirfenidone had no effect on the suppressive properties of naturally occurring regulatory T cells. Pirfenidone alone showed a small but significant (p < 0.05) effect on the in vivo allogeneic response while the combination of pirfenidone and low dose rapamycin had more remarkable effect in reducing the alloantigen response with prolonged graft survival. Conclusion Pirfenidone may be an important new agent in transplantation, with particular relevance to combating chronic rejection by inhibiting both fibroproliferative and alloimmune responses. PMID:19667934

Leptin stimulation of cell cycle and inhibition of apoptosis gene and protein expression in OVCAR-3 ovarian cancer cells.

PubMed

Ptak, Anna; Kolaczkowska, Elzbieta; Gregoraszczuk, Ewa L

2013-04-01

The OVCAR-3 cell line expressing the long (ObRb) and short (ObRt) isoforms of leptin receptor mRNA was used to analyze the effect of leptin on the expression of selected genes and proteins involved in the cell cycle and apoptosis. OVCAR-3 cells were exposed to 2, 20, 40, and 100 ng/ml of leptin. Cell proliferation was determined using the alamarBlue cell viability test and flow cytometry. Apoptosis was measured using a cellular DNA fragmentation ELISA kit. The expression of selected cell cycle and apoptosis genes was evaluated by real-time PCR and confirmed by western blot. The stimulatory action of leptin on cell proliferation was observed as an increase in cells in the S and G2/M phases. Up-regulation of genes responsible for inducing cell proliferation and suppression of genes responsible for inhibition of proliferation were noted. Western blots revealed increased expression of cyclins D and A and inhibition of p21WAF1/CIP1 protein expression by leptin. Inhibition of DNA fragmentation was observed under all leptin doses. Suppression of genes involved in the extrinsic and intrinsic apoptotic pathway was observed. Western blots illustrated decreased Bad, TNFR1, and caspase 6 protein expression in response to leptin treatment. Leptin promotes ovarian cancer cell line growth by up-regulating genes and proteins responsible for inducing cell proliferation as well as down-regulating pro-apoptotic genes and proteins in apoptotic pathways. Results of this study warrant examining the relationship between the risk of ovarian cancer and elevated leptin levels in obese women.

IL-3 induces apoptosis in a ras-transformed myeloid cell line.

PubMed

Ahmed, N; Anderson, S M; Berridge, M V

1999-04-01

Growth factors promote cell survival and proliferation. Homeostasis is maintained by programmed cell death which occurs when the growth stimulus is withdrawn, in response to negative growth regulators such as interferons, TNF-alpha and CD95 ligand, or following differentiation. Although acutely-transforming oncogenes often overcome the need for growth factors, growth regulatory cytokines can influence proliferative responses of transformed cells. In this study we investigated the effects of IL-3 on the proliferative responses of parental bone marrow-derived 32D cells and cells transformed with ras and abl oncogenes. We show that treatment of ras-transformed 32D cells with IL-3 reduced proliferative responses and decreased colony-forming ability. These effects were exacerbated in the absence of serum and associated with inhibition of tyrosine kinase activity, down-regulation of RAS and MYC expression, and induction of apoptosis as indicated by DNA fragmentation. In contrast, treatment of parental 32D cells with IL-3, which is obligatory for cell survival and proliferation, increased tyrosine kinase activity, upregulated MYC and RAS expression and maintained DNA integrity. With abl-transformed cells, proliferation and colony-forming ability were also inhibited by IL-3. Tyrosine kinase activity and MYC expression were reduced, but early apoptosis was not evident. Calcium uptake however, was stimulated by IL-3 in both parental and oncogene-transformed cells. These results suggest that threshold levels of tyrosine kinase activity are necessary for cell survival and proliferation and that with ras-transformed cells, IL-3 treatment may result in this threshold being breached. We conclude that in some situations, growth-promoting cytokines can inhibit proliferation of transformed cells and induce cell death by apoptosis.

Melatonin promotes circadian rhythm-induced proliferation through Clock/histone deacetylase 3/c-Myc interaction in mouse adipose tissue.

PubMed

Liu, Zhenjiang; Gan, Lu; Luo, Dan; Sun, Chao

2017-05-01

Melatonin is synthesized in the pineal gland and controls circadian rhythm of peripheral adipose tissue, resulting in changes in body weight. Although core regulatory components of clock rhythmicity have been defined, insight into the mechanisms of circadian rhythm-mediated proliferation in adipose tissue is still limited. Here, we showed that melatonin (20 mg/kg/d) promoted circadian and proliferation processes in white adipose tissue. The circadian amplitudes of brain and muscle aryl hydrocarbon receptor nuclear translocator-like 1 (Bmal1, P<.05) and circadian locomotor output cycles kaput (Clock, P<.05), period 2 (Per2, P<.05), cyclin E (P<.05), and c-Myc (P<.05) were directly increased by melatonin in adipose tissue. Melatonin also promoted cell cycle and increased cell numbers (P<.05), which was correlated with the Clock expression (P<.05). Further analysis demonstrated that Clock bound to the E-box elements in the promoter region of c-Myc and then directly stimulated c-Myc transcription. Moreover, Clock physically interacted with histone deacetylase 3 (HDAC3) and formed a complex with c-Myc to promote adipocyte proliferation. Melatonin also attenuated circadian disruption and promoted adipocyte proliferation in chronic jet-lagged mice and obese mice. Thus, our study found that melatonin promoted adipocyte proliferation by forming a Clock/HDAC3/c-Myc complex and subsequently driving the circadian amplitudes of proliferation genes. Our data reveal a novel mechanism that links circadian rhythm to cell proliferation in adipose tissue. These findings also identify a new potential means for melatonin to prevent and treat sleep deprivation-caused obesity. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Cellular response of osteoblasts to low modulus Ti-24Nb-4Zr-8Sn alloy mesh structure.

PubMed

Nune, K C; Misra, R D K; Li, S J; Hao, Y L; Yang, R

2017-03-01

Titanium alloys (Ti-6Al-4V and Ti-6Al-7Nb) are widely used for implants, which are characterized by high elastic modulus (∼110 GPa) with (α + β) structure and that may induce undesirable stress shielding effect and immune responses associated with the presence of toxic elements. In this regard, we have combined the attributes of a new alloy design and the concept of additive manufacturing to fabricate 3D scaffolds with an interconnected porous structure. The new alloy is a β-type Ti-24Nb-4Zr-8Sn (Ti2448) alloy with significantly reduced modulus. In the present study, we explore the biological response of electron beam melted low modulus Ti2448 alloy porous mesh structure through the elucidation of bioactivity and osteoblast functions. The cellular activity was explored in terms of cell-to-cell communication involving proliferation, spreading, synthesis of extracellular and intracellular proteins, differentiation, and mineralization. The formation of fine apatite-like crystals on the surface during immersion test in simulated body fluid confirmed the bioactivity of the scaffold surface, which provided the favorable osteogenic microenvironment for cell-material interaction. The combination of unique surface chemistry and interconnected porous architecture provided the desired pathway for supply of nutrients and oxygen to cells and a favorable osteogenic micro-environment for incorporation (on-growth and in-growth) of osteoblasts. The proliferation and differentiation of pre-osteoblasts and their ability to form a well mineralized bone-like extracellular matrix (ECM) by secreting bone markers (ALP, calcium, etc.) over the struts of the scaffold point toward the determining role of unique surface chemistry and 3D architecture of the Ti2448 alloy mesh structure in modulating osteoblasts functions. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 859-870, 2017. © 2016 Wiley Periodicals, Inc.

Recombinant adenovirus of SEA and CD80 genes driven by MMRE and mouse TERT promoter induce effective antitumor immune responses against different types of tumor cells in vitro and in vivo.

PubMed

Si, Shao-Yan; Liu, Jun-Li; Liu, Jun-Lian; Xu, Bing-Xin; Li, Jian-Zhong; Qin, Ya-Ya; Song, Shu-Jun

2017-05-01

Staphylococcus enterotoxin A (SEA) is a powerful immunostimulant and can stimulate T cells bearing certain T-cell receptor β-chain variable regions when bound to major histocompatibility complex II molecules. SEA is widely used in research of antitumor therapy. The low affinity T-cell receptor (TCR) interaction with SEA in the absence of MHC class II antigens is sufficient for the induction of cytotoxicity but requires additional CD28/B7 signaling to result in proliferation of resting T cells. In this study, we constructed recombinant adenovirus (named as Ad-MMRE-mTERT-BIS) carrying membrane-expressing SEA (named as SEAtm) and CD80 driven by Myc-Max response elements (MMRE) and mouse telomerase reverse transcriptase (mTERT) promoter to reduce toxicity and to improve safety and efficiency. We demonstrated that Ad-MMRE-mTERT-BIS could make SEAtm and CD80 to co-express highly on the surface of Hepa1-6 and B16 cells, at low level on the surface of CT26 cells, but not in NIH3T3. Hepa1-6 and B16 cells infected by the recombinant adenovirus induced proliferation of CD4+ and CD8+ T cells and increased cytokine [interleukin (IL)-2, tumor necrosis factor (TNF)-α, interferon (IFN)-γ] production in vitro. Intratumoral injection of Ad-MMRE-mTERT-BIS in hepatoma and melanoma mouse models induced tumor-specific cytotoxic T cells in the spleen. Moreover, hepatoma and melanoma xenografts were suppressed by treatment with Ad-MMRE-mTERT-BIS and the survival time of treated mice was prolonged. These findings suggest that recombinant adenovirus of SEA and CD80 genes driven by mTERT promoter could induce effective antitumor immune responses against different kinds of tumor cells in vitro and in vivo.

A PPARgamma mutant serves as a dominant negative inhibitor of PPAR signaling and is localized in the nucleus.

PubMed

Berger, J; Patel, H V; Woods, J; Hayes, N S; Parent, S A; Clemas, J; Leibowitz, M D; Elbrecht, A; Rachubinski, R A; Capone, J P; Moller, D E

2000-04-25

The peroxisomal proliferator-activated receptors (PPARs) are members of the nuclear receptor superfamily that act as ligand-activated transcription factors. PPARgamma plays a critical role in regulating adipocyte differentiation and lipid metabolism. Recently, thiazolidinedione (TZD) and select non-TZD antidiabetic agents have been identified as PPARgamma agonists. To further characterize this receptor subclass, a mutant hPPARgamma lacking five carboxyl-terminal amino acids was produced (hPPARgamma2Delta500). In COS-1 cells transfected with PPAR-responsive reporter constructs, the mutant receptor could not be activated by a potent PPARgamma agonist. When cotransfected with hPPARgamma2 or hPPARalpha, hPPARgamma2Delta500 abrogated wild-type receptor activity in a dose-responsive manner. hPPARgamma2Delta500 was also impaired with respect to binding of a high-affinity radioligand. In addition, its conformation was unaffected by normally saturating concentrations of PPARgamma agonist as determined by protease protection experiments. Electrophoretic mobility shift assays demonstrated that hPPARgamma2Delta500 and hPPARgamma2 both formed heterodimeric complexes with human retinoidxreceptor alpha (hRXRalpha) and could bind a peroxisome proliferator-responsive element (PPRE) with similar affinity. Therefore, hPPARgamma2Delta500 appears to repress PPAR activity by competing with wild type receptor to dimerize with RXR and bind the PPRE. In addition, the mutant receptor may titrate out factors required for PPAR-regulated transcriptional activation. Both hPPARgamma2 and hPPARgamma2Delta500 localized to the nucleus of transiently transfected COS-1 cells as determined by immunofluorescence using a PPARgamma-specific antibody. Thus, nuclear localization of PPARgamma occurs independently of its activation state. The dominant negative mutant, hPPARgamma2Delta500, may prove useful in further studies to characterize PPAR functions both in vitro and in vivo

Stimulatory effect of boron and manganese salts on keratinocyte migration.

PubMed

Chebassier, Nathalie; Ouijja, El Houssein; Viegas, Isabelle; Dreno, Brigitte

2004-01-01

Keratinocyte proliferation and migration are essential for the reconstruction of the cutaneous barrier after skin injury. Interestingly, thermal waters which are rich in trace elements (e.g. boron and manganese), are known to be able to improve wound healing. In order to understand the mechanism of action of this effect, our study investigated the in vitro modulation of keratinocyte migration and proliferation by boron and manganese salts, which are present in high concentrations in a thermal water (Saint Gervais). Our in vitro study demonstrated that incubating keratinocytes for 24 h with boron salts at concentrations between 0.5 and 10 microg/ml or manganese salts at concentrations between 0.1 and 1.5 microg/ml accelerated wound closure compared with control medium (+20%). As this acceleration was not related to an increase in keratinocyte proliferation we suggest that boron and manganese act on wound healing mainly by increasing the migration of keratinocytes.

Effects of Lidocaine-Mediated CPEB3 Upregulation in Human Hepatocellular Carcinoma Cell Proliferation In Vitro

PubMed Central

Liu, Hongjun; Wang, Yiru; Chen, Bing

2018-01-01

Lidocaine displays antitumor activity by inducing apoptosis and suppressing tumor growth in human hepatocellular carcinoma (HepG2) cells in vitro. However, the molecular mechanism underlying lidocaine-mediated antitumor activity is unclear. In this study, HepG2 cells were treated with lidocaine, and cell proliferation and colony-forming ability were assessed. The expression level of cytoplasmic polyadenylation element binding protein 3 (CPEB3) was detected by real-time quantitative PCR and western blot. Lidocaine treatment resulted in decreased HepG2 cell viability and colony formation in a dose-dependent manner. In hepatocellular carcinoma patient samples, CPEB3 was downregulated and was associated with poor prognosis and high-grade malignancy. Additionally, CPEB3 was a critical mediator of lidocaine-induced repression of HepG2 cell proliferation. These results demonstrated that lidocaine decreased cell viability and colony-forming ability of HepG2 cells by upregulating CPEB3 expression.

Cardiac lipin 1 expression is regulated by the peroxisome proliferator activated receptor γ coactivator 1α/estrogen related receptor axis

PubMed Central

Mitra, Mayurranjan S.; Schilling, Joel D.; Wang, Xiaowei; Jay, Patrick Y.; Huss, Janice M.; Su, Xiong; Finck, Brian N.

2011-01-01

Lipin family proteins (lipin 1, 2, and 3) are bifunctional intracellular proteins that regulate metabolism by acting as coregulators of DNA-bound transcription factors and also dephosphorylate phosphatidate to form diacylglycerol [phosphatidate phosphohydrolase activity] in the triglyceride synthesis pathway. Herein, we report that lipin 1 is enriched in heart and that hearts of mice lacking lipin 1 (fld mice) exhibit accumulation of phosphatidate. We also demonstrate that the expression of the gene encoding lipin 1 (Lpin1) is under the control of the estrogen-related receptors (ERRs) and their coactivator the peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α). PGC-1α, ERRα, or ERRγ overexpression increased Lpin1 transcription in cultured ventricular myocytes and the ERRs were associated with response elements in the first intron of the Lpin1 gene. Concomitant RNAi-mediated knockdown of ERRα and ERRγ abrogated the induction of lipin 1 expression by PGC-1α overexpression. Consistent with these data, 3-fold overexpression of PGC-1α in intact myocardium of transgenic mice increased cardiac lipin 1 and ERRα/γ expression. Similarly, injection of the β2-adrenergic agonist clenbuterol induced PGC-1α and lipin 1 expression, and the induction in lipin 1 after clenbuterol occurred in a PGC-1α-dependent manner. In contrast, expression of PGC-1α, ERRα, ERRγ, and lipin 1 was down-regulated in failing heart. Cardiac phosphatidic acid phosphohydrolase activity was also diminished, while cardiac phosphatidate content was increased, in failing heart. Collectively, these data suggest that lipin 1 is the principal lipin protein in the myocardium and is regulated in response to physiologic and pathologic stimuli that impact cardiac metabolism. PMID:21549711

Activated α2-macroglobulin binding to human prostate cancer cells triggers insulin-like responses.

PubMed

Misra, Uma Kant; Pizzo, Salvatore Vincent

2015-04-10

Ligation of cell surface GRP78 by activated α2-macroglobulin (α2M*) promotes cell proliferation and suppresses apoptosis. α2M*-treated human prostate cancer cells exhibit a 2-3-fold increase in glucose uptake and lactate secretion, an effect similar to insulin treatment. In both α2M* and insulin-treated cells, the mRNA levels of SREBP1-c, SREBP2, fatty-acid synthase, acetyl-CoA carboxylase, ATP citrate lyase, and Glut-1 were significantly increased together with their protein levels, except for SREBP2. Pretreatment of cells with α2M* antagonist antibody directed against the carboxyl-terminal domain of GRP78 blocks these α2M*-mediated effects, and silencing GRP78 expression by RNAi inhibits up-regulation of ATP citrate lyase and fatty-acid synthase. α2M* induces a 2-3-fold increase in lipogenesis as determined by 6-[(14)C]glucose or 1-[(14)C]acetate incorporation into free cholesterol, cholesterol esters, triglycerides, free fatty acids, and phosphatidylcholine, which is blocked by inhibitors of fatty-acid synthase, PI 3-kinase, mTORC, or an antibody against the carboxyl-terminal domain of GRP78. We also assessed the incorporation of [(14)CH3]choline into phosphatidylcholine and observed similar effects. Lipogenesis is significantly affected by pretreatment of prostate cancer cells with fatostatin A, which blocks sterol regulatory element-binding protein proteolytic cleavage and activation. This study demonstrates that α2M* functions as a growth factor, leading to proliferation of prostate cancer cells by promoting insulin-like responses. An antibody against the carboxyl-terminal domain of GRP78 may have important applications in prostate cancer therapy. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Activated α2-Macroglobulin Binding to Human Prostate Cancer Cells Triggers Insulin-like Responses

PubMed Central

Misra, Uma Kant; Pizzo, Salvatore Vincent

2015-01-01

Ligation of cell surface GRP78 by activated α2-macroglobulin (α2M*) promotes cell proliferation and suppresses apoptosis. α2M*-treated human prostate cancer cells exhibit a 2–3-fold increase in glucose uptake and lactate secretion, an effect similar to insulin treatment. In both α2M* and insulin-treated cells, the mRNA levels of SREBP1-c, SREBP2, fatty-acid synthase, acetyl-CoA carboxylase, ATP citrate lyase, and Glut-1 were significantly increased together with their protein levels, except for SREBP2. Pretreatment of cells with α2M* antagonist antibody directed against the carboxyl-terminal domain of GRP78 blocks these α2M*-mediated effects, and silencing GRP78 expression by RNAi inhibits up-regulation of ATP citrate lyase and fatty-acid synthase. α2M* induces a 2–3-fold increase in lipogenesis as determined by 6-[14C]glucose or 1-[14C]acetate incorporation into free cholesterol, cholesterol esters, triglycerides, free fatty acids, and phosphatidylcholine, which is blocked by inhibitors of fatty-acid synthase, PI 3-kinase, mTORC, or an antibody against the carboxyl-terminal domain of GRP78. We also assessed the incorporation of [14CH3]choline into phosphatidylcholine and observed similar effects. Lipogenesis is significantly affected by pretreatment of prostate cancer cells with fatostatin A, which blocks sterol regulatory element-binding protein proteolytic cleavage and activation. This study demonstrates that α2M* functions as a growth factor, leading to proliferation of prostate cancer cells by promoting insulin-like responses. An antibody against the carboxyl-terminal domain of GRP78 may have important applications in prostate cancer therapy. PMID:25720493

hCLCA2 is a p53-inducible inhibitor of breast cancer cell proliferation

PubMed Central

Walia, Vijay; Ding, Ming; Kumar, Sumit; Nie, Daotai; Premkumar, Louis; Elble, Randolph C.

2009-01-01

hCLCA2 is frequently downregulated in breast cancer and is a candidate tumor suppressor gene. We show here that the hCLCA2 gene is strongly induced by p53 in response to DNA damage. Adenoviral expression of p53 induces hCLCA2 in a variety of breast cell lines. Further, we find that p53 binds to consensus elements in the hCLCA2 promoter and mutation of these sites abolishes p53-responsiveness and induction by DNA damage. Adenoviral transduction of hCLCA2 into immortalized cells induces p53, CDK inhibitors p21 and p27, and cell cycle arrest by 24 hours, and caspase induction and apoptosis by 40 hours post-infection. Transduction of the malignant tumor cell line BT549 on the other hand does not induce p53, p21, or p27 but instead induces apoptosis directly and more rapidly. Knockout and knockdown studies indicate that growth inhibition and apoptosis are signaled via multiple pathways. Conversely, suppression of hCLCA2 by RNA interference enhances proliferation of MCF10A and reduces sensitivity to doxorubicin. Gene expression profiles indicate that hCLCA2 levels are strongly predictive of tumor cell sensitivity to doxorubicin and other chemotherapeutics. Because certain Cl- channels are proposed to promote apoptosis by reducing intracellular pH, we tested whether, and established that, hCLCA2 enhances Cl- current in breast cancer cells and reduces pH to ∼6.7. These results reveal hCLCA2 as a novel p53-inducible growth inhibitor, explain how its downregulation confers a survival advantage to tumor cells, and suggest both prognostic and therapeutic applications. PMID:19654313

Molecular analysis of peroxisome proliferation in the hamster.

PubMed

Choudhury, Agharul I; Sims, Helen M; Horley, Neill J; Roberts, Ruth A; Tomlinson, Simon R; Salter, Andrew M; Bruce, Mary; Shaw, P Nicholas; Kendall, David; Barrett, David A; Bell, David R

2004-05-15

Three novel P450 members of the cytochrome P450 4A family were cloned as partial cDNAs from hamster liver, characterised as novel members of the CYP4A subfamily, and designated CYP4A17, 18, and 19. Hamsters were treated with the peroxisome proliferator-activated receptor alpha (PPARalpha) agonists, methylclofenapate (MCP) or Wy-14,643, and shown to develop hepatomegaly and induction of CYP4A17 RNA, and concomitant induction of lauric acid 12- hydroxylase. This treatment also resulted in hypolipidaemia, which was most pronounced in the VLDL fraction, with up to 50% reduction in VLDL-triglycerides; by contrast, blood cholesterol concentration was unaffected by this treatment. These data show that hamster is highly responsive to induction of CYP4A by peroxisome proliferators. To characterise the molecular basis of peroxisome proliferation, the hamster PPARalpha was cloned and shown to encode a 468-amino-acid protein, which is highly similar to rat and mouse PPARalpha proteins. The level of expression of hamster PPARalpha in liver is intermediate between mouse and guinea pig. These results fail to support the hypothesis that the level of PPARalpha in liver is directly responsible for species differences in peroxisome proliferation.

Proliferation: Threat and Response

DTIC Science & Technology

2001-01-01

weapons program threatens Japan, South Korea, and U.S. forces and interests in the region. In North Africa and the Middle East, states of proliferation...fanatical terrorists or self-proclaimed apocalyptic prophets. The followers of Usama bin Laden have, in fact, already trained with toxic chemicals...18 SOUTH ASIA

Low-level laser irradiation promotes the proliferation and maturation of keratinocytes during epithelial wound repair

PubMed Central

Sperandio, Felipe F.; Simões, Alyne; Corrêa, Luciana; Aranha, Ana Cecília C.; Giudice, Fernanda S.; Hamblin, Michael R.; Sousa, Suzana C.O.M.

2015-01-01

Low-level laser therapy (LLLT) has been extensively employed to improve epithelial wound healing, though the exact response of epithelium maturation and stratification after LLLT is unknown. Thus, this study aimed to assess the in vitro growth and differentiation of keratinocytes (KCs) and in vivo wound healing response when treated with LLLT. Human KCs (HaCaT cells) showed an enhanced proliferation with all the employed laser energy densities (3, 6 and 12 J/cm2, 660nm, 100mW), together with an increased expression of Cyclin D1. Moreover, the immunoexpression of proteins related to epithelial proliferation and maturation (p63, CK10, CK14) all indicated a faster maturation of the migrating KCs in the LLLT-treated wounds. In that way, an improved epithelial healing was promoted by LLLT with the employed parameters; this improvement was confirmed by changes in the expression of several proteins related to epithelial proliferation and maturation. PMID:25411997

Homeostatic Proliferation and IL-7R Alpha Expression Do Not Correlate with Enhanced T Cell Proliferation and Protection in Chronic Mouse Malaria

PubMed Central

Stephens, Robin; Seddon, Benedict; Langhorne, Jean

2011-01-01

While chronic infection has been shown to enhance protection from disease caused by several pathogens, the mechanisms are not known. The gamma-c family of cytokines IL-7, IL-2, and IL-15 are implicated in homeostatic proliferation, which is thought to maintain T cell memory. However in chronic infection, prolonged antigen exposure itself may contribute to lymphocyte survival. We have previously observed that chronic malaria infection enhances protection to re-infection, as well as enhancing B cell responses. Here, we show that chronic Plasmodium chabaudi malaria infection in mice enhances the expansion of CD4+ T cells in a second infection, and that this correlates with increased expression of the IL-2/15 Receptor beta (CD122) on memory T cells, as well as increasing IL-2 producers on re-infection. IL-2 has been recently linked to improved secondary proliferation, while the role of IL-7 in maintenance of CD4+ memory cells has been demonstrated in homeostatic proliferation, but its role in protective memory populations in infectious disease protective has not been fully investigated. Increased IL-7Rα (CD127) expression correlated, as previously reported with increased turnover of CD4 memory cells, however, this was not linked to protection or enhanced response to rechallenge, These data support the idea that antigen or IL-2 production resulting from chronic stimulation may play a role in an enhanced secondary T cell response. PMID:22039531

Perilipin, a critical regulator of fat storage and breakdown, is a target gene of estrogen receptor-related receptor {alpha}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Akter, Mst. Hasina; Yamaguchi, Tomohiro; Hirose, Fumiko

2008-04-11

Perilipin is a protein localized on lipid droplet surfaces in adipocytes and steroidogenic cells, playing a central role in regulated lipolysis. Expression of the perilipin gene is markedly induced during adipogenesis. We found that transcription from the perilipin gene promoter is activated by an orphan nuclear receptor, estrogen receptor-related receptor (ERR){alpha}. A response element to this receptor was identified in the promoter region by a gene reporter assay, the electrophoretic-gel mobility-shift assay and the chromatin immunoprecipitation assay. Peroxisome proliferator-activated receptor {gamma} coactivator (PGC)-1{alpha} enhanced, whereas small heterodimer partner (SHP) repressed, the transactivating function of ERR{alpha} on the promoter. Thus, themore » perilipin gene expression is regulated by a transcriptional network controlling energy metabolism, substantiating the functional importance of perilipin in the maintenance of body energy balance.« less

Review: the role of vitamin D in nervous system health and disease.

PubMed

DeLuca, G C; Kimball, S M; Kolasinski, J; Ramagopalan, S V; Ebers, G C

2013-08-01

Vitamin D and its metabolites have pleomorphic roles in both nervous system health and disease. Animal models have been paramount in contributing to our knowledge and understanding of the consequences of vitamin D deficiency on brain development and its implications for adult psychiatric and neurological diseases. The conflation of in vitro, ex vivo, and animal model data provide compelling evidence that vitamin D has a crucial role in proliferation, differentiation, neurotrophism, neuroprotection, neurotransmission, and neuroplasticity. Vitamin D exerts its biological function not only by influencing cellular processes directly, but also by influencing gene expression through vitamin D response elements. This review highlights the epidemiological, neuropathological, experimental and molecular genetic evidence implicating vitamin D as a candidate in influencing susceptibility to a number of psychiatric and neurological diseases. The strength of evidence varies for schizophrenia, autism, Parkinson's disease, amyotrophic lateral sclerosis, Alzheimer's disease, and is especially strong for multiple sclerosis. © 2013 British Neuropathological Society.

Anoctamin 1 (TMEM16A) is essential for testosterone-induced prostate hyperplasia.

PubMed

Cha, Joo Young; Wee, Jungwon; Jung, Jooyoung; Jang, Yongwoo; Lee, Byeongjun; Hong, Gyu-Sang; Chang, Beom Chul; Choi, Yoon-La; Shin, Young Kee; Min, Hye-Young; Lee, Ho-Young; Na, Tae-Young; Lee, Mi-Ock; Oh, Uhtaek

2015-08-04

Benign prostatic hyperplasia (BPH) is characterized by an enlargement of the prostate, causing lower urinary tract symptoms in elderly men worldwide. However, the molecular mechanism underlying the pathogenesis of BPH is unclear. Anoctamin1 (ANO1) encodes a Ca(2+)-activated chloride channel (CaCC) that mediates various physiological functions. Here, we demonstrate that it is essential for testosterone-induced BPH. ANO1 was highly amplified in dihydrotestosterone (DHT)-treated prostate epithelial cells, whereas the selective knockdown of ANO1 inhibited DHT-induced cell proliferation. Three androgen-response elements were found in the ANO1 promoter region, which is relevant for the DHT-dependent induction of ANO1. Administration of the ANO1 blocker or Ano1 small interfering RNA, inhibited prostate enlargement and reduced histological abnormalities in vivo. We therefore concluded that ANO1 is essential for the development of prostate hyperplasia and is a potential target for the treatment of BPH.

Anoctamin 1 (TMEM16A) is essential for testosterone-induced prostate hyperplasia

PubMed Central

Cha, Joo Young; Wee, Jungwon; Jung, Jooyoung; Jang, Yongwoo; Lee, Byeongjun; Hong, Gyu-Sang; Chang, Beom Chul; Choi, Yoon-La; Shin, Young Kee; Min, Hye-Young; Lee, Ho-Young; Na, Tae-Young; Lee, Mi-Ock; Oh, Uhtaek

2015-01-01

Benign prostatic hyperplasia (BPH) is characterized by an enlargement of the prostate, causing lower urinary tract symptoms in elderly men worldwide. However, the molecular mechanism underlying the pathogenesis of BPH is unclear. Anoctamin1 (ANO1) encodes a Ca2+-activated chloride channel (CaCC) that mediates various physiological functions. Here, we demonstrate that it is essential for testosterone-induced BPH. ANO1 was highly amplified in dihydrotestosterone (DHT)-treated prostate epithelial cells, whereas the selective knockdown of ANO1 inhibited DHT-induced cell proliferation. Three androgen-response elements were found in the ANO1 promoter region, which is relevant for the DHT-dependent induction of ANO1. Administration of the ANO1 blocker or Ano1 small interfering RNA, inhibited prostate enlargement and reduced histological abnormalities in vivo. We therefore concluded that ANO1 is essential for the development of prostate hyperplasia and is a potential target for the treatment of BPH. PMID:26153424

LLNL/LANS mission committee meeting

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burns, Michael J

2010-12-06

Recent events continue to show the national security imperative of the global security mission: (1) Fighting Proliferation - (a) At Yongbyon, 'a modern, industrial-scale U-enrichment facility w/2000 centrifuges' seen Nov. 2010, (b) In Iran, fueling began at Bushehr while P5+1/lran talks delayed to Dec. 2010; (2) Continuing need to support the warfighter and IC - (a) tensions on the Korean peninsula, (b) primitative IEDs a challenge in Afghanistan, (c) cyber command, (d)another Georgian smuggling event; and (3) Countering terrorisms on US soil - (a) toner cartridge bomb, (b) times square bomb, (c) christmas tree bomb. Joint Technical Operations Team (JTOT)more » and Accident Response Group (ARG) elements deployed to two East Coast locations in November to work a multi-weapon scenario. LANL provided 70% of on-duty field and reconstitution teams for both Marble Challenge 11-01 and JD 11-01. There were a total of 14 deployments in FY10.« less

Lymphocyte Redox Imbalance and Reduced Proliferation after a Single Session of High Intensity Interval Exercise.

PubMed

Tossige-Gomes, Rosalina; Costa, Karine Beatriz; Ottone, Vinícius de Oliveira; Magalhães, Flávio de Castro; Amorim, Fabiano Trigueiro; Rocha-Vieira, Etel

2016-01-01

This study investigated whether an acute session of high-intensity interval training (HIIT) is sufficient to alter lymphocyte function and redox status. Sixteen young healthy men underwent a HIIT session on a cycloergometer, consisting of eight bouts of 1 min at 90-100% of peak power, with 75 seconds of active recovery at 30 W between bouts. Venous blood was collected before, immediately after, and 30 minutes after the HIIT session. In response to Staphylococcus aureus superantigen B (SEB) stimulation, lymphocyte proliferation decreased and the IL-2 concentration increased after the HIIT session. However, the HIIT session had no effect on lymphocyte proliferation or IL-2 response to phytohemagglutinin stimulation. The HIIT session also induced lymphocyte redox imbalance, characterized by an increase in the concentration of thiobarbituric acid reactive substances and a decrease in the activity of the antioxidant enzyme catalase. Lymphocyte viability was not affected by the HIIT session. The frequencies of CD25+ and CD69+ T helper and B lymphocytes in response to superantigen stimulation were lower after exercise, suggesting that superantigen-induced lymphocyte activation was reduced by HIIT. However, HIIT also led to a reduction in the frequency of CD4+ and CD19+ cells, so the frequencies of CD25+ and CD69+ cells within the CD4 and CD19 cell populations were not affected by HIIT. These data indicate that the reduced lymphocyte proliferation observed after HIIT is not due to reduced early lymphocyte activation by superantigen. Our findings show that an acute HIIT session promotes lymphocyte redox imbalance and reduces lymphocyte proliferation in response to superantigenic, but not to mitogenic stimulation. This observation cannot be explained by alteration of the early lymphocyte activation response to superantigen. The manner in which lymphocyte function modulation by an acute HIIT session can affect individual immunity and susceptibility to infection is important and requires further investigation.

Lymphocyte Redox Imbalance and Reduced Proliferation after a Single Session of High Intensity Interval Exercise

PubMed Central

Tossige-Gomes, Rosalina; Costa, Karine Beatriz; Ottone, Vinícius de Oliveira; Magalhães, Flávio de Castro; Amorim, Fabiano Trigueiro; Rocha-Vieira, Etel

2016-01-01

This study investigated whether an acute session of high-intensity interval training (HIIT) is sufficient to alter lymphocyte function and redox status. Sixteen young healthy men underwent a HIIT session on a cycloergometer, consisting of eight bouts of 1 min at 90–100% of peak power, with 75 seconds of active recovery at 30 W between bouts. Venous blood was collected before, immediately after, and 30 minutes after the HIIT session. In response to Staphylococcus aureus superantigen B (SEB) stimulation, lymphocyte proliferation decreased and the IL-2 concentration increased after the HIIT session. However, the HIIT session had no effect on lymphocyte proliferation or IL-2 response to phytohemagglutinin stimulation. The HIIT session also induced lymphocyte redox imbalance, characterized by an increase in the concentration of thiobarbituric acid reactive substances and a decrease in the activity of the antioxidant enzyme catalase. Lymphocyte viability was not affected by the HIIT session. The frequencies of CD25+ and CD69+ T helper and B lymphocytes in response to superantigen stimulation were lower after exercise, suggesting that superantigen-induced lymphocyte activation was reduced by HIIT. However, HIIT also led to a reduction in the frequency of CD4+ and CD19+ cells, so the frequencies of CD25+ and CD69+ cells within the CD4 and CD19 cell populations were not affected by HIIT. These data indicate that the reduced lymphocyte proliferation observed after HIIT is not due to reduced early lymphocyte activation by superantigen. Our findings show that an acute HIIT session promotes lymphocyte redox imbalance and reduces lymphocyte proliferation in response to superantigenic, but not to mitogenic stimulation. This observation cannot be explained by alteration of the early lymphocyte activation response to superantigen. The manner in which lymphocyte function modulation by an acute HIIT session can affect individual immunity and susceptibility to infection is important and requires further investigation. PMID:27096389

CSF-1 Receptor-Dependent Colon Development, Homeostasis and Inflammatory Stress Response

PubMed Central

Huynh, Duy; Akçora, Dilara; Malaterre, Jordane; Chan, Chee Kai; Dai, Xu-Ming; Bertoncello, Ivan; Stanley, E. Richard; Ramsay, Robert G.

2013-01-01

The colony stimulating factor-1 (CSF-1) receptor (CSF-1R) directly regulates the development of Paneth cells (PC) and influences proliferation and cell fate in the small intestine (SI). In the present study, we have examined the role of CSF-1 and the CSF-1R in the large intestine, which lacks PC, in the steady state and in response to acute inflammation induced by dextran sulfate sodium (DSS). As previously shown in mouse, immunohistochemical (IHC) analysis of CSF-1R expression showed that the receptor is baso-laterally expressed on epithelial cells of human colonic crypts, indicating that this expression pattern is shared between species. Colons from Csf1r null and Csf1op/op mice were isolated and sectioned for IHC identification of enterocytes, enteroendocrine cells, goblet cells and proliferating cells. Both Csf1r−/− and Csf1op/op mice were found to have colon defects in enterocytes and enteroendocrine cell fate, with excessive goblet cell staining and reduced cell proliferation. In addition, the gene expression profiles of the cell cycle genes, cyclinD1, c-myc, c-fos, and c-myb were suppressed in Csf1r−/− colonic crypt, compared with those of WT mice and the expression of the stem cell marker gene Lgr5 was markedly reduced. However, analysis of the proliferative responses of immortalized mouse colon epithelial cells (lines; Immorto-5 and YAMC) indicated that CSF-1R is not a major regulator of colonocyte proliferation and that its effects on proliferation are indirect. In an examination of the acute inflammatory response, Csf1r +/− male mice were protected from the adverse affects of DSS-induced colitis compared with WT mice, while Csf1r +/− female mice were significantly less protected. These data indicate that CSF-1R signaling plays an important role in colon homeostasis and stem cell gene expression but that the receptor exacerbates the response to inflammatory challenge in male mice. PMID:23451116

Orbital Fibroblasts From Thyroid Eye Disease Patients Differ in Proliferative and Adipogenic Responses Depending on Disease Subtype

PubMed Central

Kuriyan, Ajay E.; Woeller, Collynn F.; O'Loughlin, Charles W.; Phipps, Richard P.; Feldon, Steven E.

2013-01-01

Purpose. Thyroid eye disease (TED) patients are classified as type I (predominantly fat compartment enlargement) or type II (predominantly extraocular muscle enlargement) based on orbital imaging. Orbital fibroblasts (OFs) can be driven to proliferate or differentiate into adipocytes in vitro. We tested the hypothesis that type I OFs undergo more adipogenesis than type II OFs, whereas type II OFs proliferate more than type I OFs. We also examined the effect of cyclooxygenase (COX) inhibitors on OF adipogenesis and proliferation. Methods. Type I, type II, and non-TED OFs were treated with transforming growth factor-beta (TGFβ) to induce proliferation and with 15-deoxy-Δ−12,14-prostaglandin J2 (15d-PGJ2) to induce adipogenesis. Proliferation was measured using the [3H]thymidine assay, and adipogenesis was measured using the AdipoRed assay, Oil Red O staining, and flow cytometry. The effect of COX inhibition on adipogenesis and proliferation was also studied. Results. Type II OFs incorporated 1.7-fold more [3H]thymidine than type I OFs (P < 0.05). Type I OFs accumulated 4.8-fold more lipid than type II OFs (P < 0.05) and 12.6-fold more lipid than non-TED OFs (P < 0.05). Oil Red O staining and flow cytometry also demonstrated increased adipogenesis in type I OFs compared to type II and non-TED OFs. Cyclooxygenase inhibition significantly decreased proliferation and adipogenesis in type II OFs, but not type I OFs. Conclusions. We have demonstrated that OFs from TED patients have heterogeneous responses to proproliferative and proadipogenic stimulators in vitro in a manner that corresponds to their different clinical manifestations. Furthermore, we demonstrated a differential effect of COX inhibitors on type I and type II OF proliferation and adipogenesis. PMID:24135759

ELAC (3,12-di-O-acetyl-8-O-tigloilingol), a plant-derived lathyrane diterpene, induces subventricular zone neural progenitor cell proliferation through PKCβ activation.

PubMed

Murillo-Carretero, Maribel; Geribaldi-Doldán, Noelia; Flores-Giubi, Eugenia; García-Bernal, Francisco; Navarro-Quiroz, Elkin A; Carrasco, Manuel; Macías-Sánchez, Antonio J; Herrero-Foncubierta, Pilar; Delgado-Ariza, Antonio; Verástegui, Cristina; Domínguez-Riscart, Jesús; Daoubi, Mourad; Hernández-Galán, Rosario; Castro, Carmen

2017-07-01

Pharmacological strategies aimed to facilitate neuronal renewal in the adult brain, by promoting endogenous neurogenesis, constitute promising therapeutic options for pathological or traumatic brain lesions. We have previously shown that non-tumour-promoting PKC-activating compounds (12-deoxyphorbols) promote adult neural progenitor cell (NPC) proliferation in vitro and in vivo, enhancing the endogenous neurogenic response of the brain to a traumatic injury. Here, we show for the first time that a diterpene with a lathyrane skeleton can also activate PKC and promote NPC proliferation. We isolated four lathyranes from the latex of Euphorbia plants and tested their effect on postnatal NPC proliferation, using neurosphere cultures. The bioactive lathyrane ELAC (3,12-di-O-acetyl-8-O-tigloilingol) was also injected into the ventricles of adult mice to analyse its effect on adult NPC proliferation in vivo. The lathyrane ELAC activated PKC and significantly increased postnatal NPC proliferation in vitro, particularly in synergy with FGF2. In addition ELAC stimulated proliferation of NPC, specifically affecting undifferentiated transit amplifying cells. The proliferative effect of ELAC was reversed by either the classical/novel PKC inhibitor Gö6850 or the classical PKC inhibitor Gö6976, suggesting that NPC proliferation is promoted in response to activation of classical PKCs, particularly PKCß. ELAC slightly increased the proportion of NPC expressing Sox2. The effects of ELAC disappeared upon acetylation of its C7-hydroxyl group. We propose lathyranes like ELAC as new drug candidates to modulate adult neurogenesis through PKC activation. Functional and structural comparisons between ELAC and phorboids are included. © 2017 The British Pharmacological Society.

Loss of DLK expression in WI-38 human diploid fibroblasts induces a senescent-like proliferation arrest

DOE Office of Scientific and Technical Information (OSTI.GOV)

Daviau, Alex; Couture, Jean-Philippe; Blouin, Richard, E-mail: Richard.Blouin@USherbrooke.ca

Highlights: {yields} Role of DLK in cell proliferation. {yields} Modulation of DLK expression during cell cycle progression. {yields} DLK knockdown induces proliferation arrest and senescence. {yields} DLK-depleted cells display loss of cyclin D1 and up-regulation of p21. {yields} DLK participates in cell proliferation by modulating cell cycle regulator expression. -- Abstract: DLK, a serine/threonine kinase that functions as an upstream activator of the mitogen-activated protein kinase (MAPK) pathways, has been shown to play a role in development, cell differentiation, apoptosis and neuronal response to injury. Interestingly, recent studies have shown that DLK may also be required for cell proliferation, althoughmore » little is known about its specific functions. To start addressing this issue, we studied how DLK expression is modulated during cell cycle progression and what effect DLK depletion has on cell proliferation in WI-38 fibroblasts. Our results indicate that DLK protein levels are low in serum-starved cells, but that serum addition markedly stimulated it. Moreover, RNA interference experiments demonstrate that DLK is required for ERK activity, expression of the cell cycle regulator cyclin D1 and proliferation of WI-38 cells. DLK-depleted cells also show a senescent phenotype as revealed by senescence-associated galactosidase activity and up-regulation of the senescence pathway proteins p53 and p21. Consistent with a role for p53 in this response, inhibition of p53 expression by RNA interference significantly alleviated senescence induced by DLK knockdown. Together, these findings indicate that DLK participates in cell proliferation and/or survival, at least in part, by modulating the expression of cell cycle regulatory proteins.« less

Horizontal gene acquisitions, mobile element proliferation, and genome decay in the host-restricted plant pathogen erwinia tracheiphila

USDA-ARS?s Scientific Manuscript database

Modern industrial agriculture depends on high-density cultivation of genetically similar crop plants, creating favorable conditions for the emergence of novel pathogens with increased fitness in managed compared with ecologically intact settings. Here, we present the genome sequence of six strains o...

Mesenchymal stem cells induce dermal fibroblast responses to injury

PubMed Central

Smith, Andria N.; Willis, Elise; Chan, Vincent T.; Muffley, Lara A.; Isik, F. Frank; Gibran, Nicole S.; Hocking, Anne M.

2009-01-01

Although bone marrow-derived mesenchymal stem cells have been shown to promote repair when applied to cutaneous wounds, the mechanism for this response remains to be determined. The aim of this study was to determine the effects of paracrine signaling from mesenchymal stem cells on dermal fibroblast responses to injury including proliferation, migration and expression of genes important in wound repair. Dermal fibroblasts were co-cultured with bone marrow-derived mesenchymal stem cells grown in inserts, which allowed for paracrine interactions without direct cell contact. In this co-culture model, bone marrow-derived mesenchymal stem cells regulate dermal fibroblast proliferation, migration and gene expression. When co-cultured with mesenchymal stem cells, dermal fibroblasts show increased proliferation and accelerated migration in a scratch assay. A chemotaxis assay also demonstrated that dermal fibroblasts migrate towards bone marrow-derived mesenchymal stem cells. A PCR array was used to analyze the effect of mesenchymal stem cells on dermal fibroblast gene expression. In response to mesenchymal stem cells, dermal fibroblasts up-regulate integrin alpha 7 expression and down-regulate expression of ICAM1, VCAM1 and MMP11. These observations suggest that mesenchymal stem cells may provide an important early signal for dermal fibroblast responses to cutaneous injury. PMID:19666021

Stable SREBP-1a knockdown decreases the cell proliferation rate in human preadipocyte cells without inducing senescence

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alvarez, María Soledad; Fernandez-Alvarez, Ana; Cucarella, Carme

2014-04-25

Highlights: • SGBS cells mostly expressed SREBP-1a variant. • SREBP-1a knockdown decreased the proliferation of SGBS cells without inducing senescence. • We have identified RBBP8 and CDKN3 genes as potential SREBP-1a targets. - Abstract: Sterol regulatory element binding proteins (SREBP), encoded by the Srebf1 and Srebf2 genes, are important regulators of genes involved in cholesterol and fatty acid metabolism. Whereas SREBP-2 controls the cholesterol synthesis, SREBP-1 proteins (-1a and -1c) function as the central hubs in lipid metabolism. Despite the key function of these transcription factors to promote adipocyte differentiation, the roles of SREBP-1 proteins during the preadipocyte state remainmore » unknown. Here, we evaluate the role of SREBP-1 in preadipocyte proliferation using RNA interference technology. Knockdown of the SREBP-1a gene decreased the proliferation rate in human SGBS preadipocyte cell strain without inducing senescence. Furthermore, our data identified retinoblastoma binding protein 8 and cyclin-dependent kinase inhibitor 3 genes as new potential SREBP-1 targets, in addition to cyclin-dependent kinase inhibitor 1A which had already been described as a gene regulated by SREBP-1a. These data suggested a new role of SREBP-1 in adipogenesis via regulation of preadipocyte proliferation.« less

Potentiation of lymphocyte proliferative responses by nickel sulfide

NASA Technical Reports Server (NTRS)

Jaramillo, A.; Sonnenfeld, G.

1992-01-01

Crystalline nickel sulfide (NiS) induced a spleen cell proliferation that resembles a mixed lymphocyte reaction (MLR). It depended on cell-cell interaction, induced high levels of interleukin-1 (IL-1) and interleukin-2 (IL-2) and the responding cell subpopulation was composed of CD4+ T lymphocytes. Furthermore, the proliferation was inhibited in a dose-dependent manner by magnesium. Crystalline NiS also increased significantly the spleen cell proliferative response to concanavalin A (Con A) and lipopolysaccharide (LPS) with magnesium potentiating the combined effects of crystalline NiS and mitogens. Interestingly, crystalline NiS did not show any effect on the induction of IL-2 by Con A. The results described herein suggest that crystalline NiS can potentiate both antigenic (MLR) and mitogenic (Con A and LPS) proliferative responses in vitro. Crystalline NiS appears to potentiate these responses by acting in the form of ionic nickel on several intracellular targets for which magnesium ions have different noncompetitive interactions. The effects of magnesium on the potentiating action of crystalline NiS are different depending upon the type of primary stimulatory signal for proliferation (mitogenic or antigenic).

Antigen-dependent proliferation and cytokine induction in respiratory syncytial virus-infected cotton rats reflect the presence of effector-memory T cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Richter, Bettina W.M.; Onuska, Jaya M.; Niewiesk, Stefan

2005-06-20

Respiratory syncytial virus (RSV) is a major cause of lower airway disease in infants and children. Immunity to RSV is not long lasting, resulting in re-occurring infections throughout life. Effective long-lived immunity results when central-memory T cells that proliferate vigorously and secrete IL-2 are present. In contrast, effector-memory T cells that mainly produce IFN-{gamma}, facilitate virus clearance but are not long lived. To identify the type of memory response induced after RSV-A (Long) infection, we characterized the kinetics of the antigen-specific immune response and identified the types of cytokines induced. RSV-specific lymphocytic proliferation following primary and secondary infection was similar,more » and in both cases responses waned within a short period of time. In addition, mRNA for IFN-{gamma} but not IL-2 was induced in RSV-specific CD4{sup +} T cells. This supports the idea that the presence of effector-memory rather than central-memory T cells contributes to the ineffectiveness of the immune response to RSV.« less

Phosphorylation at tyrosine 114 of Proliferating Cell Nuclear Antigen (PCNA) is required for adipogenesis in response to high fat diet

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lo, Yuan-Hung; Ho, Po-Chun; Chen, Min-Shan

Highlights: Black-Right-Pointing-Pointer Proliferating Cell Nuclear Antigen (PCNA) is phosphorylated at Y114. Black-Right-Pointing-Pointer Phospho-Y114 of PCNA is not required for cell proliferation for normal growth. Black-Right-Pointing-Pointer MCE during adipogenesis is abolished in the lack of the phosphorylation. Black-Right-Pointing-Pointer Homozygous Y114F mice are resistant to high fat diet induced obesity. Black-Right-Pointing-Pointer Our results shed light on the interface between proliferation and differentiation. -- Abstract: Clonal proliferation is an obligatory component of adipogenesis. Although several cell cycle regulators are known to participate in the transition between pre-adipocyte proliferation and terminal adipocyte differentiation, how the core DNA synthesis machinery is coordinately regulated in adipogenesismore » remains elusive. PCNA (Proliferating Cell Nuclear Antigen) is an indispensable component for DNA synthesis during proliferation. Here we show that PCNA is subject to phosphorylation at the highly conserved tyrosine residue 114 (Y114). Replacing the Y114 residue with phenylalanine (Y114F), which is structurally similar to tyrosine but cannot be phosphorylated, does not affect normal animal development. However, when challenged with high fat diet, mice carrying homozygous Y114F alleles (PCNA{sup F/F}) are resistant to adipose tissue enlargement in comparison to wild-type (WT) mice. Mouse embryonic fibroblasts (MEFs) harboring WT or Y114F mutant PCNA proliferate at similar rates. However, when subjected to adipogenesis induction in culture, PCNA{sup F/F} MEFs are not able to re-enter the cell cycle and fail to form mature adipocytes, while WT MEFs undergo mitotic clonal expansion in response to the adipogenic stimulation, accompanied by enhanced Y114 phosphorylation of PCNA, and differentiate to mature adipocytes. Consistent with the function of Y114 phosphorylation in clonal proliferation in adipogenesis, fat tissues isolated from WT mice contain significantly more adipocytes than those isolated from PCNA{sup F/F} mice. This study identifies a critical role for PCNA in adipose tissue development, and for the first time identifies a role of the core DNA replication machinery at the interface between proliferation and differentiation.« less

Small interfering RNA transfection against serum response factor mediates growth inhibition of benign prostatic hyperplasia fibroblasts.

PubMed

Nolte, Andrea; Aufderklamm, Stefan; Scheu, Katrin; Walker, Tobias; König, Olivia; Böttcher, Miriam; Niederlaender, Jan; Schwentner, Christian; Schlensak, Christian; Stenzl, Arnulf; Wendel, Hans Peter

2013-02-01

To treat urethral strictures of the lower urinary tract, urethrotomy is the method of choice. But this minimally invasive method suffers from poor outcome rates and leads often to restenosis of the urinary tract because of hyper-proliferating fibroblasts. Our aim is to minimize the proliferation of excessive tissue due to a new minimal invasive therapeutic approach. As an appropriate model, we isolated fibroblasts from different benign prostatic hyperplasia patients and transfected them with small interfering RNA (siRNA) against the transcription factor serum response factor (SRF), a key factor for cell cycle regulation and apoptosis. The resulting knockdown of SRF was examined on the messenger RNA level by quantitative real-time polymerase chain reaction and on the protein level by western blot. The correlation of SRF silencing and impact on cell proliferation was examined by xCELLigence, 5-bromo-2'-deoxiuridine proliferation assay, total cell counts, and senescence assay. The transfection of primary prostatic fibroblasts with SRFsiRNA revealed specific and significant knockdown of SRF, leading to significant inhibition of proliferation after the second transfection, which was revealed by proliferation assay and total cell number. The results of this study indicate a substantial role of SRF in prostatic fibroblasts and we suggest that SRF silencing might be used for the treatment of urethral strictures to achieve a durably patent urethra.

A Population of Progenitor Cells in the Basal and Intermediate Layers of the Murine Bladder Urothelium Contributes to Urothelial Development and Regeneration

PubMed Central

Colopy, Sara A.; Bjorling, Dale E.; Mulligan, William A.; Bushman, Wade

2014-01-01

Background Homeostatic maintenance and repair of the bladder urothelium has been attributed to proliferation of keratin 5-expressing basal cells (K5-BC) with subsequent differentiation into superficial cells. Recent evidence, however, suggests that the intermediate cell layer harbors a population of progenitor cells. We use label-retaining cell (LRC) methodology in conjunction with a clinically relevant model of uropathogenic Escherichia coli (UPEC)-induced injury to characterize urothelial ontogeny during development and in response to diffuse urothelial injury. Results In the developing urothelium, proliferating cells were dispersed throughout the K5-BC and intermediate cells layers, becoming progressively concentrated in the K5-BC layer with age. When 5-bromo-2-deoxyuridine (BrdU) was administered during urothelial development, LRCs in the adult were found within the K5-BC, intermediate, and superficial cell layers, the location dependent upon time of labeling. UPEC inoculation resulted in loss of the superficial cell layer followed by robust proliferation of K5-BCs and intermediate cells. LRCs within the K5-BC and intermediate cell layers proliferated in response to injury. Conclusions Urothelial development and regeneration following injury relies on proliferation of K5-BC and intermediate cells. The existence and proliferation of LRCs within both the K5-BC and intermediate cell layers suggests the presence of two populations of urothelial progenitor cells. PMID:24796293

The Lcn2-engineered HEK-293 cells show senescence under stressful condition

PubMed Central

Bahmani, Bahareh; Amiri, Fatemeh; Mohammadi Roushandeh, Amaneh; Bahadori, Marzie; Harati, Mozhgan Dehghan; Habibi Roudkenar, Mehryar

2015-01-01

Objective(s): Lipocalin2 (Lcn2) gene is highly expressed in response to various types of cellular stresses. The precise role of Lcn2 has not been fully understood yet. However, it plays a key role in controlling vital cellular processes such as proliferation, apoptosis and metabolism. Recently it was shown that Lcn2 decreases senescence and increases proliferation of mesenchymal stem cells (MSC) with finite life span under either normal or oxidative stress conditions. However, Lcn2 effects on immortal cell line with infinite proliferation are not defined completely. Materials and Materials and Methods: HEK-293 cells were transfected with recombinant pcDNA3.1 containing Lcn2 fragment (pcDNA3.1-Lcn2). Expression of lipocalin2 in transfected cells was evaluated by RT-PCR, real time RT-PCR, and ELISA. Different cell groups were treated with H2O2 and WST-1 assay was performed to determine their proliferation rate. Senescence was studied by β-galactosidase and gimsa staining methods as well as evaluation of the expression of senescence-related genes by real time RT-PCR. Results: Lcn2 increased cell proliferation under normal culture condition, while the proliferation slightly decreased under oxidative stress. This decrease was further found to be attributed to senescence. Conclusion: Our findings indicated that under harmful conditions, Lcn2 gene is responsible for the regulation of cell survival through senescence. PMID:26124931

Lymphocyte responses to influenza and tetanus toxoid in vitro following intensive exercise and carbohydrate ingestion on consecutive days.

PubMed

Bishop, Nicolette C; Walker, Gary J; Bowley, Lee A; Evans, Kate F; Molyneux, Karen; Wallace, Fiona A; Smith, Alice C

2005-10-01

The effect of carbohydrate (CHO) ingestion on antigen- (rather than mitogen-) stimulated T-cell responses to prolonged, intensive exercise may give a more realistic insight into the effect of CHO on T-cell functional capacity and subsequent infection risk. This study investigated the effect of CHO ingestion during prolonged, intensive exercise on influenza- and tetanus toxoid-stimulated T-cell cytokine mRNA expression and proliferation. Mitogen- [phytohemagglutinin (PHA)] stimulated proliferation was assessed for comparison. Responses were assessed following exercise on consecutive mornings to determine any carryover effect. Fifteen male games players performed two exercise trials in a double-blind, randomized, crossover design. Each trial comprised 90 min of intensive, intermittent running on consecutive mornings, with either CHO (6.4% wt/vol) or placebo (PLA) beverage ingestion before, during, and after each bout of exercise. Postexercise CD3(+) cell counts were higher in PLA than CHO on both days (P < 0.05). Antigen-stimulated T-cell cytokine mRNA expression was unaffected by exercise or CHO ingestion. Before exercise on day 2, T-cell proliferative responses to PHA, influenza, and tetanus toxoid were higher in CHO than PLA by 99, 80, and 58%, respectively (P < 0.01 for PHA, P < 0.05 for influenza and tetanus toxoid). At 1 h postexercise on day 2, PHA-induced proliferation was 70% higher in CHO than PLA (P < 0.05), yet there were no differences between trials for antigen-induced proliferative responses. Therefore, mitogen-induced T-cell proliferation following strenuous exercise and CHO does not necessarily reflect responses to specific antigens and, consequently, may not provide a good model for the situation in vivo.

Reverse crosstalk of TGFβ and PPARβ/δ signaling identified by transcriptional profiling

PubMed Central

Stockert, Josefine; Adhikary, Till; Kaddatz, Kerstin; Finkernagel, Florian; Meissner, Wolfgang; Müller-Brüsselbach, Sabine; Müller, Rolf

2011-01-01

Previous work has provided strong evidence for a role of peroxisome proliferator-activated receptor β/δ (PPARβ/δ) and transforming growth factor-β (TGFβ) in inflammation and tumor stroma function, raising the possibility that both signaling pathways are interconnected. We have addressed this hypothesis by microarray analyses of human diploid fibroblasts induced to myofibroblastic differentiation, which revealed a substantial, mostly reverse crosstalk of both pathways and identified distinct classes of genes. A major class encompasses classical PPAR target genes, including ANGPTL4, CPT1A, ADRP and PDK4. These genes are repressed by TGFβ, which is counteracted by PPARβ/δ activation. This is mediated, at least in part, by the TGFβ-induced recruitment of the corepressor SMRT to PPAR response elements, and its release by PPARβ/δ ligands, indicating that TGFβ and PPARβ/δ signals are integrated by chromatin-associated complexes. A second class represents TGFβ-induced genes that are downregulated by PPARβ/δ agonists, exemplified by CD274 and IL6, which is consistent with the anti-inflammatory properties of PPARβ/δ ligands. Finally, cooperative regulation by both ligands was observed for a minor group of genes, including several regulators of cell proliferation. These observations indicate that PPARβ/δ is able to influence the expression of distinct sets of both TGFβ-repressed and TGFβ-activated genes in both directions. PMID:20846954

Antitumorigenic Effects of ZAKβ, an Alternative Splicing Isoform of ZAK.

PubMed

Lee, Jin-Sun; Lin, Yuh-Yih; Wang, Tsu-Shing; Liu, Jer-Yuh; Lin, Wei-Wen; Yang, Jaw-Ji

2018-02-28

Sterile alpha motif (SAM)- and leucine-zipper-containing kinase (ZAK) plays a role in the regulation of cell cycle progression and oncogenic transformation. The ZAK gene generates two transcript variants, ZAKα and ZAKβ, through alternative splicing. In this study, we identified that ZAKα proteins were upregulated in tumor tissues, whereas ZAKβ proteins were mostly expressed in corresponding normal tissues. The ectopically expressed ZAKβ proteins in cancer cells inhibited cancer cell proliferation as well as anchorage-independent growth. The ZAKβ:ZAKα protein ratio played a role in the regulation of the cyclic adenosine monophosphate (cAMP) signaling pathway, whereas high ZAKβ protein levels led to the activation of cAMP response element binding protein 1 (CREB1) and exerted antitumor properties. Overexpression of ZAKβ or CREB1 cDNAs in cancer cells inhibited anchorage-independent growth and also reduced the levels of cyclooxygenase 2 (Cox2) and β-catenin proteins. Cancer cells treated with doxorubicin (Doxo) resulted in the switching from the expression of ZAKα to ZAKβ and also inhibited cancer cell growth in soft agar, demonstrating that pharmacological drugs could be used to manipulate endogenous reprogramming splicing events and resulting in the activation of endogenous antitumorigenic properties. We showed that the two ZAK transcript variants, ZAKα and ZAKβ, had opposite biological functions in the regulation of tumor cell proliferation in that ZAKβ had powerful antitumor properties and that ZAKα could promote tumor growth.

E2F1 induces p19INK4d, a protein involved in the DNA damage response, following UV irradiation.

PubMed

Carcagno, Abel L; Giono, Luciana E; Marazita, Mariela C; Castillo, Daniela S; Pregi, Nicolás; Cánepa, Eduardo T

2012-07-01

Central to the maintenance of genomic integrity is the cellular DNA damage response. Depending on the type of genotoxic stress and through the activation of multiple signaling cascades, it can lead to cell cycle arrest, DNA repair, senescence, and apoptosis. p19INK4d, a member of the INK4 family of CDK inhibitors, plays a dual role in the DNA damage response, inhibiting cell proliferation and promoting DNA repair. Consistently, p19INK4d has been reported to become upregulated in response to UV irradiation and a great variety of genotoxic agents. Here, this induction is shown to result from a transcriptional stimulatory mechanism that can occur at every phase of the cell cycle except during mitosis. Moreover, evidence is presented that demonstrates that E2F1 is involved in the induction of p19INK4d following UV treatment, as it is prevented by E2F1 protein ablation and DNA-binding inhibition. Specific inhibition of this regulation using triplex-forming oligonucleotides that target the E2F response elements present in the p19INK4d promoter also block p19INK4d upregulation and sensitize cells to DNA damage. These results constitute the first description of a mechanism for the induction of p19INK4d in response to UV irradiation and demonstrate the physiological relevance of this regulation following DNA damage.

Deciphering the Adaptive Immune Response to Ovarian Cancer

DTIC Science & Technology

2013-10-01

Additionally, anti-cancer drugs such as 2-phenyl benzimidazole (2- PB) disrupt the Golgi apparatus, which leads to reduced cell proliferation and tumour...of Golgi processing by 2-phenyl benzimidazole analogs blocks cell proliferation and slows tumor growth. Cancer Chemother Pharmacol 2008; 61: 1045–1058

Practical uses for ecdysteroids in mammals including humans: an update

PubMed Central

Lafont, R.; Dinan, L.

2003-01-01

Ecdysteroids are widely used as inducers for gene-switch systems based on insect ecdysteroid receptors and genes of interest placed under the control of ecdysteroid-response elements. We review here these systems, which are currently mainly used in vitro with cultured cells in order to analyse the role of a wide array of genes, but which are expected to represent the basis for future gene therapy strategies. Such developments raise several questions, which are addressed in detail. First, the metabolic fate of ecdysteroids in mammals, including humans, is only poorly known, and the rapid catabolism of ecdysteroids may impede their use as in vivo inducers. A second set of questions arose in fact much earlier with the pioneering “heterophylic” studies of Burdette in the early sixties on the pharmacological effects of ecdysteroids on mammals. These and subsequent studies showed a wide range of effects, most of them being beneficial for the organism (e.g. hypoglycaemic, hypocholesterolaemic, anabolic). These effects are reviewed and critically analysed, and some hypotheses are proposed to explain the putative mechanisms involved. All of these pharmacological effects have led to the development of a wide array of ecdysteroid-containing preparations, which are primarily used for their anabolic and/or “adaptogenic” properties on humans (or horses or dogs). In the same way, increasing numbers of patents have been deposited concerning various beneficial effects of ecdysteroids in many medical or cosmetic domains, which make ecdysteroids very attractive candidates for several practical uses. It may be questioned whether all these pharmacological actions are compatible with the development of ecdysteroid-inducible gene switches for gene therapy, and also if ecdysteroids should be classified among doping substances. Abbreviation: 20E 20-hydroxyecdysone 2d20E 2-deoxy-20-hydroxyecdysone 2dE 2-deoxyecdysone BAH bisacylhydrazine BmEcR Bombyx mori EcR CfEcR Choristoneura fumiferana EcR CfUSP Choristoneura fumiferana USP CHO Chinese hamster ovary CMV cytomegalovirus DBD DNA-binding domain DmEcR Drosophila melanogaster EcR AbbE ecdysone EcR ecdysteroid receptor EcRE ecdysteroid response element EHT effective half-time ERE oestrogen response element GR glucocorticoid receptor GRE glucocorticoid response element HEK human embryonic kidney HvEcR Heliothis virescens EcR LBD ligand binding domain murA muristerone A PKA protein kinase A polB polypodine B ponA ponasterone A PPAR peroxisome proliferator-activated receptor RAR retinoic acid receptor RXR retinoid X receptor TR thyroid receptor USP ultraspiracle VDR vitamin D receptor VEGF vascular endothelial growth factor PMID:15844229

Black seed oil ameliorates allergic airway inflammation by inhibiting T-cell proliferation in rats.

PubMed

Shahzad, Muhammad; Yang, Xudong; Raza Asim, M B; Sun, Qingzhu; Han, Yan; Zhang, Fujun; Cao, Yongxiao; Lu, Shemin

2009-02-01

The black seeds, from the Ranunculaceae family, have been traditionally used by various cultures as a natural remedy for several ailments. In this study, we examined the effect of black seed oil as an immunomodulator in a rat model of allergic airway inflammation. Rats sensitized to ovalbumin and challenged intranasally with ovalbumin to induce an allergic inflammatory response were compared to ovalbumin-sensitized, intranasally ovalbumin-exposed rats pretreated with intraperitoneally administered black seed oil and to control rats. The levels of IgE, IgG1 and ova-specific T-cell proliferation in spleen were measured by ELISA. The pro-inflammatory cytokine IL-4, IL-5, IL-6 and TGF-beta1 mRNA expression levels were measured by reverse transcription polymerase chain reaction. The intraperitoneal administration of black seed oil inhibited the Th2 type immune response in rats by preventing inflammatory cell infiltration and pathological lesions in the lungs. It significantly decreased the nitric oxide production in BALF, total serum IgE, IgG1 and OVA-specific IgG1 along with IL-4, IL-5, IL-6 and TGF-beta1 mRNA expression. Black seed oil treatment resulted in decreased T-cell response evident by lesser delayed type hypersensitivity and lower T-cell proliferation in spleen. In conclusion, black seed oil exhibited a significant reduction in all the markers of allergic inflammation mainly by inhibiting the delayed type hypersensitivity and T-cell proliferation. The data suggests that inhibition of T-cell response may be responsible for immunomodulatory effect of black seed oil in the rat model of allergic airway inflammation.

Matrix stiffness reverses the effect of actomyosin tension on cell proliferation.

PubMed

Mih, Justin D; Marinkovic, Aleksandar; Liu, Fei; Sharif, Asma S; Tschumperlin, Daniel J

2012-12-15

The stiffness of the extracellular matrix exerts powerful effects on cell proliferation and differentiation, but the mechanisms transducing matrix stiffness into cellular fate decisions remain poorly understood. Two widely reported responses to matrix stiffening are increases in actomyosin contractility and cell proliferation. To delineate their relationship, we modulated cytoskeletal tension in cells grown across a physiological range of matrix stiffnesses. On both synthetic and naturally derived soft matrices, and across a panel of cell types, we observed a striking reversal of the effect of inhibiting actomyosin contractility, switching from the attenuation of proliferation on rigid substrates to the robust promotion of proliferation on soft matrices. Inhibiting contractility on soft matrices decoupled proliferation from cytoskeletal tension and focal adhesion organization, but not from cell spread area. Our results demonstrate that matrix stiffness and actomyosin contractility converge on cell spreading in an unexpected fashion to control a key aspect of cell fate.

Matrix stiffness reverses the effect of actomyosin tension on cell proliferation

PubMed Central

Mih, Justin D.; Marinkovic, Aleksandar; Liu, Fei; Sharif, Asma S.; Tschumperlin, Daniel J.

2012-01-01

Summary The stiffness of the extracellular matrix exerts powerful effects on cell proliferation and differentiation, but the mechanisms transducing matrix stiffness into cellular fate decisions remain poorly understood. Two widely reported responses to matrix stiffening are increases in actomyosin contractility and cell proliferation. To delineate their relationship, we modulated cytoskeletal tension in cells grown across a physiological range of matrix stiffnesses. On both synthetic and naturally derived soft matrices, and across a panel of cell types, we observed a striking reversal of the effect of inhibiting actomyosin contractility, switching from the attenuation of proliferation on rigid substrates to the robust promotion of proliferation on soft matrices. Inhibiting contractility on soft matrices decoupled proliferation from cytoskeletal tension and focal adhesion organization, but not from cell spread area. Our results demonstrate that matrix stiffness and actomyosin contractility converge on cell spreading in an unexpected fashion to control a key aspect of cell fate. PMID:23097048

microRNA-451a regulates colorectal cancer proliferation in response to radiation.

PubMed

Ruhl, Rebecca; Rana, Shushan; Kelley, Katherine; Espinosa-Diez, Cristina; Hudson, Clayton; Lanciault, Christian; Thomas, Charles R; Liana Tsikitis, V; Anand, Sudarshan

2018-05-03

Colorectal cancer (CRC) is a leading cause of cancer-related death. The biologic response of CRC to standard of care adjuvant therapies such as chemotherapy and radiation are poorly understood. MicroRNAs (miRs) have been shown to affect CRC progression and metastasis. Therefore, we hypothesized that specific miRs modulate CRC response to chemoradiation. In this study, we used miR expression profiling and discovered a set of microRNAs upregulated rapidly in response to either a single 2 Gy dose fraction or a 10 Gy dose of γ-radiation in mouse colorectal carcinoma models. We used gain and loss-of-function studies in 2D and 3Dcell proliferation assays and colony formation assays to understand the role of the top miR candidate from our profiling. We used Student's T-tests for simple comparisons and two-factor ANOVA for evaluating significance. The most upregulated candidate at early time points in our signature, miR-451a inhibited tumor cell proliferation and attenuated surviving fraction in longer-term cultures. Conversely, inhibition of miR-451a increased proliferation, tumorsphere formation, and surviving fraction of tumor cells. Using a bioinformatics approach, we identified four genes, CAB39, EMSY, MEX3C, and EREG, as targets of miR-451a. Transfection of miR-451a decreased both mRNA and protein levels of these targets. Importantly, we found miR-451a expression was high and CAB39, EMSY levels were low in a small subset of rectal cancer patients who had a partial response to chemoradiation when compared to patients that had no response. Finally, analysis of a TCGA colorectal cancer dataset revealed that CAB39 and EMSY are upregulated at the protein level in a significant number of CRC patients. Higher levels of CAB39 and EMSY correlated with poorer overall survival. Taken together, our data indicates miR-451a is induced by radiation and may influence colorectal carcinoma proliferation via CAB39 and EMSY pathways.

Low-Dose Radiation Induces Cell Proliferation in Human Embryonic Lung Fibroblasts but not in Lung Cancer Cells: Importance of ERK1/2 and AKT Signaling Pathways.

PubMed

Liang, Xinyue; Gu, Junlian; Yu, Dehai; Wang, Guanjun; Zhou, Lei; Zhang, Xiaoying; Zhao, Yuguang; Chen, Xiao; Zheng, Shirong; Liu, Qiang; Cai, Lu; Cui, Jiuwei; Li, Wei

2016-01-01

Hormesis and adaptive responses are 2 important biological effects of low-dose ionizing radiation (LDR). In normal tissue, LDR induces hormesis as evinced by increased cell proliferation; however, whether LDR also increases tumor cell proliferation needs to be investigated. In this study, cell proliferation was assayed by total cell numbers and the Cell Counting Kit 8 assay. Mitogen-activated protein kinases (MAPK)/extracellular signal-regulated kinase (ERK) and phosphatidylinositol 3' -kinase(PI3K)-Akt (PI3K/AKT) phosphorylation were determined by Western blot analysis. Human embryonic lung fibroblast 2BS and lung cancer NCI-H446 cell lines were irradiated with LDR at different doses (20-100 mGy). In response to 20 to 75 mGy X-rays, cell proliferation was significantly increased in 2BS but not in NCI-H446 cells. In 2BS cells, LDR at 20 to 75 mGy also stimulated phosphorylation of MAPK/ERK pathway proteins including ERK, MEK, and Raf and of the PI3K/AKT pathway protein AKT. To test whether ERK1/2 and AKT pathway activation was involved in the stimulation of cell proliferation in 2BS cells, the MAPK/ERK and PI3K/AKT pathways were inhibited using their specific inhibitors, U0126 and LY294002. U0126 decreased the phosphorylation of ERK1/2, and LY294002 decreased the phosphorylation of AKT; each could significantly inhibit LDR-induced 2BS cell proliferation. However, LDR did not stimulate these kinases, and kinase inhibitors also did not affect cell proliferation in the NCI-H446 cells. These results suggest that LDR stimulates cell proliferation via the activation of both MAPK/ERK and PI3K/AKT signaling pathways in 2BS but not in NCI-H446 cells. This finding implies the potential for applying LDR to protect normal tissues from radiotherapy without diminishing the efficacy of tumor therapy.

Low-Dose Radiation Induces Cell Proliferation in Human Embryonic Lung Fibroblasts but not in Lung Cancer Cells

PubMed Central

Liang, Xinyue; Gu, Junlian; Yu, Dehai; Wang, Guanjun; Zhou, Lei; Zhang, Xiaoying; Zhao, Yuguang; Chen, Xiao; Zheng, Shirong; Liu, Qiang; Cai, Lu

2016-01-01

Hormesis and adaptive responses are 2 important biological effects of low-dose ionizing radiation (LDR). In normal tissue, LDR induces hormesis as evinced by increased cell proliferation; however, whether LDR also increases tumor cell proliferation needs to be investigated. In this study, cell proliferation was assayed by total cell numbers and the Cell Counting Kit 8 assay. Mitogen-activated protein kinases (MAPK)/extracellular signal-regulated kinase (ERK) and phosphatidylinositol 3′ -kinase(PI3K)-Akt (PI3K/AKT) phosphorylation were determined by Western blot analysis. Human embryonic lung fibroblast 2BS and lung cancer NCI-H446 cell lines were irradiated with LDR at different doses (20-100 mGy). In response to 20 to 75 mGy X-rays, cell proliferation was significantly increased in 2BS but not in NCI-H446 cells. In 2BS cells, LDR at 20 to 75 mGy also stimulated phosphorylation of MAPK/ERK pathway proteins including ERK, MEK, and Raf and of the PI3K/AKT pathway protein AKT. To test whether ERK1/2 and AKT pathway activation was involved in the stimulation of cell proliferation in 2BS cells, the MAPK/ERK and PI3K/AKT pathways were inhibited using their specific inhibitors, U0126 and LY294002. U0126 decreased the phosphorylation of ERK1/2, and LY294002 decreased the phosphorylation of AKT; each could significantly inhibit LDR-induced 2BS cell proliferation. However, LDR did not stimulate these kinases, and kinase inhibitors also did not affect cell proliferation in the NCI-H446 cells. These results suggest that LDR stimulates cell proliferation via the activation of both MAPK/ERK and PI3K/AKT signaling pathways in 2BS but not in NCI-H446 cells. This finding implies the potential for applying LDR to protect normal tissues from radiotherapy without diminishing the efficacy of tumor therapy. PMID:26788032

Involvement of Retinoblastoma Protein and HBP1 in Histone H10 Gene Expression

PubMed Central

Lemercier, Claudie; Duncliffe, Kym; Boibessot, Isabelle; Zhang, Hui; Verdel, André; Angelov, Dimitar; Khochbin, Saadi

2000-01-01

The histone H10-encoding gene is expressed in vertebrates in differentiating cells during the arrest of proliferation. In the H10 promoter, a specific regulatory element, which we named the H4 box, exhibits features which implicate a role in mediating H10 gene expression in response to both differentiation and cell cycle control signals. For instance, within the linker histone gene family, the H4 box is found only in the promoters of differentiation-associated subtypes, suggesting that it is specifically involved in differentiation-dependent expression of these genes. In addition, an element nearly identical to the H4 box is conserved in the promoters of histone H4-encoding genes and is known to be involved in their cell cycle-dependent expression. The transcription factors interacting with the H10 H4 box were therefore expected to link differentiation-dependent expression of H10 to the cell cycle control machinery. The aim of this work was to identify such transcription factors and to obtain information concerning the regulatory pathway involved. Interestingly, our cloning strategy led to the isolation of a retinoblastoma protein (RB) partner known as HBP1. HBP1, a high-mobility group box transcription factor, interacted specifically with the H10 H4 box and moreover was expressed in a differentiation-dependent manner. We also showed that the HBP1-encoding gene is able to produce different forms of HBP1. Finally, we demonstrated that both HBP1 and RB were involved in the activation of H10 gene expression. We therefore propose that HBP1 mediates a link between the cell cycle control machinery and cell differentiation signals. Through modulating the expression of specific chromatin-associated proteins such as histone H10, HBP1 plays a vital role in chromatin remodeling events during the arrest of cell proliferation in differentiating cells. PMID:10958660

Dietary β-conglycinin prevents fatty liver induced by a high-fat diet by a decrease in peroxisome proliferator-activated receptor γ2 protein.

PubMed

Yamazaki, Tomomi; Kishimoto, Kyoko; Miura, Shinji; Ezaki, Osamu

2012-02-01

Diets high in sucrose/fructose or fat can result in hepatic steatosis (fatty liver). Mice fed a high-fat diet, especially that of saturated-fat-rich oil, develop fatty liver with an increase in peroxisome proliferator-activated receptor (PPAR) γ2 protein in liver. The fatty liver induced by a high-fat diet is improved by knockdown of liver PPARγ2. In this study, we investigated whether β-conglycinin (a major protein of soy protein) could reduce PPARγ2 protein and prevent high-fat-diet-induced fatty liver in ddY mice. Mice were fed a high-starch diet (70 energy% [en%] starch) plus 20% (wt/wt) sucrose in their drinking water or a high-safflower-oil diet (60 en%) or a high-butter diet (60 en%) for 11 weeks, by which fatty liver is developed. As a control, mice were fed a high-starch diet with drinking water. Either β-conglycinin or casein (control) was given as dietary protein. β-Conglycinin supplementation completely prevented fatty liver induced by each type of diet, along with a reduction in adipose tissue weight. β-Conglycinin decreased sterol regulatory element-binding protein (SREBP)-1c and carbohydrate response element-binding protein (ChREBP) messenger RNAs (mRNAs) in sucrose-supplemented mice, whereas it decreased PPARγ2 mRNA (and its target genes CD36 and FSP27), but did not decrease SREBP-1c and ChREBP mRNAs, in mice fed a high-fat diet. β-Conglycinin decreased PPARγ2 protein and liver triglyceride (TG) concentration in a dose-dependent manner in mice fed a high-butter diet; a significant decrease in liver TG concentration was observed at a concentration of 15 en%. In conclusion, β-conglycinin effectively prevents fatty liver induced by a high-fat diet through a decrease in liver PPARγ2 protein. Copyright © 2012 Elsevier Inc. All rights reserved.

CaMKII Signaling Stimulates Mef2c Activity In Vitro but Only Minimally Affects Murine Long Bone Development in vivo

PubMed Central

Amara, Chandra S.; Fabritius, Christine; Houben, Astrid; Wolff, Lena I.; Hartmann, Christine

2017-01-01

The long bones of vertebrate limbs form by endochondral ossification, whereby mesenchymal cells differentiate into chondrogenic progenitors, which then differentiate into chondrocytes. Chondrocytes undergo further differentiation from proliferating to prehypertrophic, and finally to hypertrophic chondrocytes. Several signaling pathways and transcription factors regulate this process. Previously, we and others have shown in chicken that overexpression of an activated form of Calcium/calmodulin-dependent kinase II (CaMKII) results in ectopic chondrocyte maturation. Here, we show that this is not the case in the mouse. Although, in vitro Mef2c activity was upregulated by about 55-fold in response to expression of an activated form of CaMKII (DACaMKII), transgenic mice that expressed a dominant-active form of CaMKII under the control of the Col2a1 regulatory elements display only a very transient and mild phenotype. Here, only the onset of chondrocyte hypertrophy at E12.5 is accelerated. It is also this early step in chondrocyte differentiation that is temporarily delayed around E13.5 in transgenic mice expressing the peptide inhibitor CaM-KIIN from rat (rKIIN) under the control of the Col2a1 regulatory elements. Yet, ultimately DACaMKII, as well as rKIIN transgenic mice are born with completely normal skeletal elements with regard to their length and growth plate organization. Hence, our in vivo analysis suggests that CaMKII signaling plays a minor role in chondrocyte maturation in mice. PMID:28361052

Effects of Interleukin-12 and Interleukin-15 on Measles-Specific T-Cell Responses in Vaccinated Infants

PubMed Central

YASUKAWA, LINDA L.; ZHANG, CATHRYN Z.; WAKIM, RIMA HANNA; RINKI, MARY; DEHOVITZ, ROSS; ARVIN, ANN M.

2008-01-01

Abstract Understanding the infant host response to measles vaccination is important because of their increased mortality from measles and the need to provide effective protection during the first year of life. Measles-specific T- and B-cell responses are lower in infants after measles vaccination than in adults. To define potential mechanisms, we investigated age-related differences in measles-specific T-cell proliferation, CD40-L expression, and IFN-γ production after measles immunization, and the effects of rhIL-12 and rhIL-15 on these responses. Measles-specific T-cell proliferation and mean IFN-γ release from infant PBMCs were significantly lower when compared with responses of vaccinated children and adults. Infant responses increased to ranges observed in children and adults when both rhIL-12 and rhIL-15 were added to PBMC cultures. Furthermore, a significant rise in T-cell proliferation and IFN-γ release was observed when infant PBMCs were stimulated with measles antigen in the presence of rhIL-12 and rhIL-15 compared to measles antigen alone. CD40-L expression by infant and adult T cells stimulated with measles antigen was comparable, but fewer infant CD40-L+ T cells expressed IFN-γ. These observations suggest that lower measles-specific T-cell immune responses elicited by measles vaccine in infants may be due to diminished levels of key cytokines. PMID:18419254

Viability and DNA damage responses of TPPII-deficient Myc- and Ras-transformed fibroblasts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsurumi, Chizuko; Firat, Elke; Gaedicke, Simone

2009-09-04

Tripeptidyl peptidase II (TPPII) is a giant cytosolic protease. Previous protease inhibitor, overexpression and siRNA studies suggested that TPPII is important for viability and proliferation of tumor cells, and for their ionizing radiation-induced DNA damage response. The possibility that TPPII could be targeted for tumor therapy prompted us to study its role in transformed cells following genetic TPPII deletion. We generated cell lines from primary fibroblasts having conditional (floxed) TPPII alleles, transformed them with both the c-myc and H-ras oncogenes, and deleted TPPII using retroviral self-deleting Cre recombinase. Clonally derived TPPIIflox/flox and TPPII-/- transformed fibroblasts showed no influences of TPPIImore » expression on basal cell survival and proliferation, nor on radiation-induced p53 activation, p21 induction, cell cycle arrest, apoptosis, or clonogenic cell death. Thus, our results do not support a generally important role of TPPII for viability and proliferation of transformed cells or their p53-mediated DNA damage response.« less

Viability and DNA damage responses of TPPII-deficient Myc- and Ras-transformed fibroblasts.

PubMed

Tsurumi, Chizuko; Firat, Elke; Gaedicke, Simone; Huai, Jisen; Mandal, Pankaj Kumar; Niedermann, Gabriele

2009-09-04

Tripeptidyl peptidase II (TPPII) is a giant cytosolic protease. Previous protease inhibitor, overexpression and siRNA studies suggested that TPPII is important for viability and proliferation of tumor cells, and for their ionizing radiation-induced DNA damage response. The possibility that TPPII could be targeted for tumor therapy prompted us to study its role in transformed cells following genetic TPPII deletion. We generated cell lines from primary fibroblasts having conditional (floxed) TPPII alleles, transformed them with both the c-myc and H-ras oncogenes, and deleted TPPII using retroviral self-deleting Cre recombinase. Clonally derived TPPIIflox/flox and TPPII-/- transformed fibroblasts showed no influences of TPPII expression on basal cell survival and proliferation, nor on radiation-induced p53 activation, p21 induction, cell cycle arrest, apoptosis, or clonogenic cell death. Thus, our results do not support a generally important role of TPPII for viability and proliferation of transformed cells or their p53-mediated DNA damage response.

Immunosuppressive activity of tilmicosin on the immune responses in mice.

PubMed

Guan, Shuang; Song, Yu; Guo, Weixiao; Chu, Xiao; Zhang, Xiaozhe; Wang, Dacheng; Lu, Jing; Deng, Xuming

2011-06-01

Tilmicosin, a semi-synthetic macrolide antibiotic that is only used in the veterinary clinic, was evaluated for its immunosuppressive activity on the immune responses to ovalbumin (OVA) in mice. Tilmicosin suppressed concanavalin A (Con A)- and lipopolysaccharide (LPS)-stimulated splenocyte proliferation in vitro. BALB/c mice were immunized subcutaneously with OVA on day 1 and 4. Beginning on the day of boosting immunization, the mice were administered intraperitoneally with tilmicosin at a single dose of 10, 30, and 90 mg/kg for 10 consecutive days. On day 14, blood samples were collected for measuring specific total-immunoglobulin G (total-IgG), IgG1, IgG2b, and splenocytes were harvested for determining lymphocyte proliferation and interleukin-2 (IL-2), interferon-γ (IFN-γ), IL-4 production. The results demonstrated that tilmicosin could significantly suppress Con A-induced splenocyte proliferation in a dose-dependent manner, decrease LPS-and OVA-induced splenocyte proliferation only at high concentration, produced less IL-2, IL-4, and IFN-γ as compared to the control in the OVA-immunized mice. Moreover, the OVA-specific IgG, IgG1, and IgG2b levels in the OVA-immunized mice were reduced by tilmicosin. These results suggest that tilmicosin could suppress the cellular and humoral immune response in mice.

Effects of melatonin or maternal nutrient restriction on vascularity and cell proliferation in the ovine placenta

USDA-ARS?s Scientific Manuscript database

Previously we reported increased umbilical artery blood flow in ewes supplemented with melatonin from mid- to late-pregnancy, while maternal nutrient restriction decreased uterine artery blood flow. To further unravel these responses, this study was designed to assess placental cell proliferation an...

Global Proliferation-Dynamics, Acquisition Strategies, and Responses. Volume 2. Nuclear Proliferation

DTIC Science & Technology

1994-09-01

due to Marvin Atkins, Joel Bengston. Richard Blumstein. John Bulger, James Bushong, Burrus Carnahan, Alexis Castor, Emerory Chase, Edward Chaves...SCIENCE BOARDATTN: DR P G K MINSKI OSD (DDR&E) ATTN: DR VICTOR REIS DEPUTY ASSISTANT SECRETARY OSD COMPTROLLER ATTN: JANE MATTHIAS ATTN: HONORABLE JOHN

Proliferation, differentiation and gene expression of osteoblasts in boron-containing associated with dexamethasone deliver from mesoporous bioactive glass scaffolds.

PubMed

Wu, Chengtie; Miron, Richard; Sculean, Anton; Kaskel, Stefan; Doert, Thomas; Schulze, Renate; Zhang, Yufeng

2011-10-01

Boron is one of the trace elements in the human body which plays an important role in bone growth. Porous mesopore bioactive glass (MBG) scaffolds are proposed as potential bone regeneration materials due to their excellent bioactivity and drug-delivery ability. The aims of the present study were to develop boron-containing MBG (B-MBG) scaffolds by sol-gel method and to evaluate the effect of boron on the physiochemistry of B-MBG scaffolds and the response of osteoblasts to these scaffolds. Furthermore, the effect of dexamethasone (DEX) delivery in B-MBG scaffold system was investigated on the proliferation, differentiation and bone-related gene expression of osteoblasts. The composition, microstructure and mesopore properties (specific surface area, nano-pore volume and nano-pore distribution) of B-MBG scaffolds have been characterized. The effect of boron contents and large-pore porosity on the loading and release of DEX in B-MBG scaffolds were also investigated. The results have shown that the incorporation of boron into MBG scaffolds slightly decreases the specific surface area and pore volume, but maintains well-ordered mesopore structure and high surface area and nano-pore volume compared to non-mesopore bioactive glass. Boron contents in MBG scaffolds did not influence the nano-pore size distribution or the loading and release of DEX. B-MBG scaffolds have the ability to maintain a sustained release of DEX in a long-term span. Incorporating boron into MBG glass scaffolds led to a controllable release of boron ions and significantly improved the proliferation and bone-related gene expression (Col I and Runx2) of osteoblasts. Furthermore, the sustained release of DEX from B-MBG scaffolds significantly enhanced alkaline phosphatase (ALP) activity and gene expressions (Col I, Runx2, ALP and BSP) of osteoblasts. These results suggest that boron plays an important role in enhancing osteoblast proliferation in B-MBG scaffold system and DEX-loaded B-MBG scaffolds show great potential as a release system to enhance osteogenic property for bone tissue engineering application. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

Surgery accelerates the development of endometriosis in mice.

PubMed

Long, Qiqi; Liu, Xishi; Guo, Sun-Wei

2016-09-01

Surgery is currently the mainstay treatment for solid tumors and many benign diseases, including endometriosis, and women tend to receive substantially more surgeries than men mainly because of gynecological and cosmetic surgeries. Despite its cosmetic, therapeutic, or even life-saving benefits, surgery is reported to increase the cancer risk and promotes cancer metastasis. Surgery activates adrenergic signaling, which in turn suppresses cell-mediated immunity and promotes angiogenesis and metastasis. Because immunity, angiogenesis, and invasiveness are all involved in the pathophysiology of endometriosis, it is unclear whether surgery may accelerate the development of endometriosis. The objective of the study was to test the hypothesis that surgery activates adrenergic signaling, increases angiogenesis, and accelerates the growth of endometriotic lesions. This was a prospective, randomized experimentation. The first experiment used 42 female adult Balb/C mice, and the second used 90 female adult Balb/C mice. In experiment 1, 3 days after the induction of endometriosis, mice were randomly divided into 3 groups of approximately equal sizes, control, laparotomy, and mastectomy. In experiment 2, propranolol infusion via Alzet pumps was used to forestall the effect of sympathetic nervous system activation by surgery. In both experiments, mice were evaluated 2 weeks after surgery. Lesion size, hotplate latency, and immunohistochemistry analysis of vascular endothelial growth factor, CD31-positive microvessels, proliferating cell nuclear antigen, phosphorylated cyclic adenosine monophosphate-responsive element-binding protein, β2-adrenergic receptor (ADRB)-2, ADRB1, ADRB3, ADRA1, and ADRA2 in ectopic implants. Both mastectomy and laparotomy increased lesion weight and exacerbated hyperalgesia, increased microvessel density and elevated the immunoreactivity against ADRB2, phosphorylated cyclic adenosine monophosphate-responsive element-binding protein, vascular endothelial growth factor, and proliferating cell nuclear antigen but not ADRB1, ADRB3, ADRA1, and ADRA2, suggesting activated adrenergic signaling, increased angiogenesis, and accelerated growth of endometriotic lesions. β-Blockade completely abrogated the facilitory effect of surgery, further underscoring the critical role of β-adrenergic signaling in mediating the effect of surgery. Surgery activates adrenergic signaling, increases angiogenesis, and accelerates the growth of endometriotic lesions in the mouse, but such a facilitory effect of surgery can be completely abrogated by β-blockade. Whether surgery can promote the development of endometriosis in humans warrants further investigation. Copyright © 2016 Elsevier Inc. All rights reserved.

HIV-1 Vpr Enhances PPARβ/δ-Mediated Transcription, Increases PDK4 Expression, and Reduces PDC Activity

PubMed Central

Shrivastav, Shashi; Zhang, Liyan; Okamoto, Koji; Lee, Hewang; Lagranha, Claudia; Abe, Yoshifusa; Balasubramanyam, Ashok; Lopaschuk, Gary D.; Kino, Tomoshige

2013-01-01

HIV infection and its therapy are associated with disorders of lipid metabolism and bioenergetics. Previous work has suggested that viral protein R (Vpr) may contribute to the development of lipodystrophy and insulin resistance observed in HIV-1–infected patients. In adipocytes, Vpr suppresses mRNA expression of peroxisomal proliferator-activating receptor-γ (PPARγ)-responsive genes and inhibits differentiation. We investigated whether Vpr might interact with PPARβ/δ and influence its transcriptional activity. In the presence of PPARβ/δ, Vpr induced a 3.3-fold increase in PPAR response element-driven transcriptional activity, a 1.9-fold increase in pyruvate dehydrogenase kinase 4 (PDK4) protein expression, and a 1.6-fold increase in the phosphorylated pyruvate dehydrogenase subunit E1α leading to a 47% decrease in the activity of the pyruvate dehydrogenase complex in HepG2 cells. PPARβ/δ knockdown attenuated Vpr-induced enhancement of endogenous PPARβ/δ-responsive PDK4 mRNA expression. Vpr induced a 1.3-fold increase in mRNA expression of both carnitine palmitoyltransferase I (CPT1) and acetyl-coenzyme A acyltransferase 2 (ACAA2) and doubled the activity of β-hydroxylacyl coenzyme A dehydrogenase (HADH). Vpr physically interacted with the ligand-binding domain of PPARβ/δ in vitro and in vivo. Consistent with a role in energy expenditure, Vpr increased state-3 respiration in isolated mitochondria (1.16-fold) and basal oxygen consumption rate in intact HepG2 cells (1.2-fold) in an etomoxir-sensitive manner, indicating that the oxygen consumption rate increase is β-oxidation–dependent. The effects of Vpr on PPAR response element activation, pyruvate dehydrogenase complex activity, and β-oxidation were reversed by specific PPARβ/δ antagonists. These results support the hypothesis that Vpr contributes to impaired energy metabolism and increased energy expenditure in HIV patients. PMID:23842279

Curcumin differentially regulates endoplasmic reticulum stress through transcriptional corepressor SMILE (small heterodimer partner-interacting leucine zipper protein)-mediated inhibition of CREBH (cAMP responsive element-binding protein H).

PubMed

Misra, Jagannath; Chanda, Dipanjan; Kim, Don-kyu; Li, Tiangang; Koo, Seung-Hoi; Back, Sung-Hoon; Chiang, John Y L; Choi, Hueng-Sik

2011-12-09

Curcumin (diferuloylmethane), a major active component of turmeric (Curcuma longa), is a natural polyphenolic compound. Herein the effect of curcumin on endoplasmic reticulum (ER) stress responsive gene expression was investigated. We report that curcumin induces transcriptional corepressor small heterodimer partner-interacting leucine zipper protein (SMILE) gene expression through liver kinase B1 (LKB1)/adenosine monophosphate-activated kinase (AMPK) signaling pathway and represses ER stress-responsive gene transcription in an ER-bound transcription factor specific manner. cAMP responsive element-binding protein H (CREBH) and activating transcription factor 6 (ATF6) are both ER-bound bZIP family transcription factors that are activated upon ER stress. Of interest, we observed that both curcumin treatment and SMILE overexpression only represses CREBH-mediated transactivation of the target gene but not ATF6-mediated transactivation. Knockdown of endogenous SMILE significantly releases the inhibitory effect of curcumin on CREBH transactivation. Intrinsic repressive activity of SMILE is observed in the Gal4 fusion system, and the intrinsic repressive domain is mapped to the C terminus of SMILE spanning amino acid residues 203-269, corresponding to the basic region leucine zipper (bZIP) domain. In vivo interaction assay revealed that through its bZIP domain, SMILE interacts with CREBH and inhibits its transcriptional activity. Interestingly, we observed that SMILE does not interact with ATF6. Furthermore, competition between SMILE and the coactivator peroxisome proliferator-activated receptor α (PGC-1α) on CREBH transactivation has been demonstrated in vitro and in vivo. Finally, chromatin immunoprecipitation assays revealed that curcumin decreases the binding of PGC-1α and CREBH on target gene promoter in a SMILE-dependent manner. Overall, for the first time we suggest a novel phenomenon that the curcumin/LKB1/AMPK/SMILE/PGC1α pathway differentially regulates ER stress-mediated gene transcription.

Nutrition beyond nutrition: plausibility of immunotrophic nutrition for space travel.

PubMed

Kulkarni, A D; Yamauchi, K; Hales, N W; Ramesh, V; Ramesh, G T; Sundaresan, A; Andrassy, R J; Pellis, N R

2002-06-01

Microgravity has adverse effects on the immune system. We examined the effects of supplemental dietary nucleotides on immune function in ground-based in vivo anti-orthostatic tail-suspended (AOS) mice and in vitro (bioreactor-BIO) analogs of microgravity. BALB/c mice were divided into the following three groups: group housed, single isolation, and AOS. Mice were fed either control chow or chow supplemented with RNA or uracil. Immune function was assessed by in vivo popliteal lymph node proliferation (PLN), in vitro PHA-stimulated proliferation of splenocytes and cytokine production. BIO splenocytes were cultured in vitro with/without PHA, a nucleoside-nucleotide mixture (NS/NT) or uridine. The cell proliferation and scanning electron microscopic examination for cells were carried out. PLN response was significantly suppressed in AOS mice (P<0.05) and was restored by RNA and uracil diets. Splenocytes from AOS mice had decreased phytohemagglutinin (PHA)-stimulated proliferation, decreased IL-2 and IFN-gamma cytokine levels (P<0.05). These responses were restored by RNA and uracil diets. In BIO cultures, PHA response was suppressed significantly, and uridine and NS/NT restored the proliferative responses. Scanning electron microscopic analysis of cells cultured in BIO revealed cells with pinched, distorted and eroded membranes. Nucleotide supplementation especially uridine restored normal activated cell surface appearance and ruffling. In the microgravity analog environment of AOS and BIO, supplemental nucleotides and especially uracil/uridine have up-regulating and immunoprotective effects with potential as a countermeasure to the observed immune dysfunction in true microgravity.

T-cell proliferative responses following sepsis in neonatal rats.

PubMed

Dallal, Ousama; Ravindranath, Thyyar M; Choudhry, Mashkoor A; Kohn, Annamarie; Muraskas, Jonathan K; Namak, Shahla Y; Alattar, Mohammad H; Sayeed, Mohammed M

2003-01-01

Both experimental and clinical evidence suggest a suppression of T-cell function in burn and sepsis. The objective of the present study was to evaluate splenocyte and purified T-cell proliferative response and IL-2 production in septic neonatal rats. We also examined if alterations in T-cell proliferation and IL-2 production in neonatal sepsis is due to elevation in PGE2. PGE2 is known to play a significant role in T-cell suppression during sepsis in adults. Sepsis was induced in 15-day-old neonatal Sprague-Dawley rats by implanting 0.1 cm3 of fecal pellet impregnated with Escherichia coli (50 CFU) and Bacteroides fragilis (10(3) CFU). Animals receiving fecal pellets without the bacteria were designated as sterile. A group of septic and sterile rats were treated with PGE2 synthesis inhibitors, NS398 and resveratrol. These treatments of animals allowed us to evaluate the role of PGE2 in T-cell suppression during neonatal sepsis. Splenocytes as well as purified T cells were prepared and then proliferative response and IL-2 productive capacities were measured. A significant suppression of splenocyte proliferation and IL-2 production was noticed in both sterile and septic animals compared to the T cells from unoperated control rats. In contrast, the proliferation and IL-2 production by nylon wool purified T cells in sterile rats was not significantly different from control rats, whereas, a significant suppression in Con A-mediated T-cell proliferation and IL-2 production noticed in septic rat T cells compared to the sterile and control rat T cells. Such decrease in T-cell proliferation and IL-2 production was accompanied with 20-25% deaths in neonates implanted with septic pellets. No mortality was noted in sterile-implanted neonates. Treatment of animals with COX-1 inhibitor had no effect on T-cell proliferation response in both septic and sterile groups, whereas COX-2 inhibitor abrogated the decrease in T-cell proliferative response in the septic group. The treatment of animals with COX-2 inhibitor also significantly prevented the sepsis-associated mortality in neonates. In conclusion, the present study demonstrated T-cell suppression during neonatal sepsis is accompanied by a decrease in IL-2 production. Such suppressions were ameliorated with COX-2 inhibitor suggesting a role for PGE2 in the suppressed T-cell-mediated immune function in neonatal sepsis. Copyright 2003 S. Karger AG, Basel

Ethanol and liver: Recent insights into the mechanisms of ethanol-induced fatty liver

PubMed Central

Liu, Jinyao

2014-01-01

Alcoholic fatty liver disease (AFLD), a potentially pathologic condition, can progress to steatohepatitis, fibrosis, and cirrhosis, leading to an increased probability of hepatic failure and death. Alcohol induces fatty liver by increasing the ratio of reduced form of nicotinamide adenine dinucleotide to oxidized form of nicotinamide adenine dinucleotide in hepatocytes; increasing hepatic sterol regulatory element-binding protein (SREBP)-1, plasminogen activator inhibitor (PAI)-1, and early growth response-1 activity; and decreasing hepatic peroxisome proliferator-activated receptor-α activity. Alcohol activates the innate immune system and induces an imbalance of the immune response, which is followed by activated Kupffer cell-derived tumor necrosis factor (TNF)-α overproduction, which is in turn responsible for the changes in the hepatic SREBP-1 and PAI-1 activity. Alcohol abuse promotes the migration of bone marrow-derived cells (BMDCs) to the liver and then reprograms TNF-α expression from BMDCs. Chronic alcohol intake triggers the sympathetic hyperactivity-activated hepatic stellate cell (HSC) feedback loop that in turn activates the HSCs, resulting in HSC-derived TNF-α overproduction. Carvedilol may block this feedback loop by suppressing sympathetic activity, which attenuates the progression of AFLD. Clinical studies evaluating combination therapy of carvedilol with a TNF-α inhibitor to treat patients with AFLD are warranted to prevent the development of alcoholic liver disease. PMID:25356030

The G protein-coupled receptor 30 is up-regulated by hypoxia-inducible factor-1alpha (HIF-1alpha) in breast cancer cells and cardiomyocytes.

PubMed

Recchia, Anna Grazia; De Francesco, Ernestina Marianna; Vivacqua, Adele; Sisci, Diego; Panno, Maria Luisa; Andò, Sebastiano; Maggiolini, Marcello

2011-03-25

GPR30, also known as GPER, has been suggested to mediate rapid effects induced by estrogens in diverse normal and cancer tissues. Hypoxia is a common feature of solid tumors involved in apoptosis, cell survival, and proliferation. The response to low oxygen environment is mainly mediated by the hypoxia-inducible factor named HIF-1α, which activates signaling pathways leading to adaptive mechanisms in tumor cells. Here, we demonstrate that the hypoxia induces HIF-1α expression, which in turn mediates the up-regulation of GPER and its downstream target CTGF in estrogen receptor-negative SkBr3 breast cancer cells and in HL-1 cardiomyocytes. Moreover, we show that HIF-1α-responsive elements located within the promoter region of GPER are involved in hypoxia-dependent transcription of GPER, which requires the ROS-induced activation of EGFR/ERK signaling in both SkBr3 and HL-1 and cells. Interestingly, the apoptotic response to hypoxia was prevented by estrogens through GPER in SkBr3 cells. Taken together, our data suggest that the hypoxia-induced expression of GPER may be included among the mechanisms involved in the anti-apoptotic effects elicited by estrogens, particularly in a low oxygen microenvironment.

Short-Chain Fatty Acid Acetate Stimulates Adipogenesis and Mitochondrial Biogenesis via GPR43 in Brown Adipocytes.

PubMed

Hu, Jiamiao; Kyrou, Ioannis; Tan, Bee K; Dimitriadis, Georgios K; Ramanjaneya, Manjunath; Tripathi, Gyanendra; Patel, Vanlata; James, Sean; Kawan, Mohamed; Chen, Jing; Randeva, Harpal S

2016-05-01

Short-chain fatty acids play crucial roles in a range of physiological functions. However, the effects of short-chain fatty acids on brown adipose tissue have not been fully investigated. We examined the role of acetate, a short-chain fatty acid formed by fermentation in the gut, in the regulation of brown adipocyte metabolism. Our results show that acetate up-regulates adipocyte protein 2, peroxisomal proliferator-activated receptor-γ coactivator-1α, and uncoupling protein-1 expression and affects the morphological changes of brown adipocytes during adipogenesis. Moreover, an increase in mitochondrial biogenesis was observed after acetate treatment. Acetate also elicited the activation of ERK and cAMP response element-binding protein, and these responses were sensitive to G(i/o)-type G protein inactivator, Gβγ-subunit inhibitor, phospholipase C inhibitor, and MAPK kinase inhibitor, indicating a role for the G(i/o)βγ/phospholipase C/protein kinase C/MAPK kinase signaling pathway in these responses. These effects of acetate were mimicked by treatment with 4-chloro-α-(1-methylethyl)-N-2-thiazolylbenzeneacetamide, a synthetic G protein-coupled receptor 43 (GPR43) agonist and were impaired in GPR43 knockdown cells. Taken together, our results indicate that acetate may have important physiological roles in brown adipocytes through the activation of GPR43.

Sphingosine-1-phosphate: a novel nonhypoxic activator of hypoxia-inducible factor-1 in vascular cells.

PubMed

Michaud, Maude D; Robitaille, Geneviève A; Gratton, Jean-Philippe; Richard, Darren E

2009-06-01

Sphingosine-1-phosphate (S1P) is a potent bioactive phospholipid responsible for a variety of vascular cell responses. Hypoxia-inducible factor-1 (HIF-1) is a transcriptional activator of genes essential for adaptation to low oxygen. S1P and HIF-1 are both important mediators of vascular cell responses such as migation, proliferation, and survival. Studies have shown that nonhypoxic stimuli can activate HIF-1 in oxygenated conditions. Here, we attempt to determine whether S1P can modulate the vascular activation of HIF-1. We show that in vascular endothelial and smooth muscle cells, activation of the S1P type-2 receptor by S1P strongly increases HIF-1 alpha protein levels, the active subunit of HIF-1. This is achieved through pVHL-independent stabilization of HIF-1 alpha. We demonstrate that the HIF-1 nuclear complex, formed on S1P stimulation, is transcriptionally active and specifically binds to a hypoxia-responsive elements. Moreover, S1P activates the expression of genes known to be closely regulated by HIF-1. Our results identify S1P as a novel and potent nonhypoxic activator of HIF-1. We believe that understanding the role played by HIF-1 in S1P gene regulation will have a strong impact on different aspects of vascular biology.

Local fibroblast proliferation but not influx is responsible for synovial hyperplasia in a murine model of rheumatoid arthritis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matsuo, Yusuke; Mizoguchi, Fumitaka; Saito, Tetsuya

Synovial fibroblasts play crucial roles in inflammation and joint destruction in rheumatoid arthritis (RA). How they accumulate in the RA joints remains unclear. This study was conducted to discern whether cellular influx from the outside of the joints and local proliferation are responsible for synovial fibroblast accumulation in an animal model of RA. We found that synovial fibroblasts were identified as GFP+ cells using collagen type I alpha 2 (Col1a2)-GFP transgenic reporter mice. Then, bone marrow transplantation and parabiosis techniques were utilized to study the cellular influx. Irradiated wild-type mice were transplanted with bone marrow from Col1a2-GFP mice. Col1a2-GFP andmore » wild-type mice were conjoined for parabiosis. The transplanted mice and the parabionts were subjected to collagen antibody-induced arthritis (CAIA). We found no GFP+ cells in the hyperplastic synovial tissues from the transplanted mice with CAIA and from the wild-type parabionts with CAIA. Furthermore, normal and CAIA synovial tissues from Col1a2-GFP mice and from fluorescent ubiquitination-based cell cycle indicator (Fucci) transgenic mice, in which cells in S/G{sub 2}/M phases of the cell cycle express Azami-Green, were studied for Ki67, a cellular proliferation marker, and vimentin, a fibroblast marker, expression. The percentages of Ki67+/GFP+ and Azami-Green+/vimentin+ cells in the CAIA synovial tissues were higher than those in the untreated synovial tissues (34% vs. 0.40% and 19% vs. 0.26%, respectively). These findings indicate that local fibroblast proliferation but not cellular influx is responsible for the synovial hyperplasia in CAIA. Suppression of proliferation of the local synovial fibroblasts should be a promising treatment for RA. - Highlights: • We studied how synovial fibroblasts accumulate in joints in a murine model of RA. • Bone marrow-derived cells did not accumulate in arthritic joints. • Synovial fibroblasts did not accumulate in arthritic joints via circulation. • Local proliferation was responsible for the synovial fibroblast accumulation.« less

Bile Acids Down-Regulate Caveolin-1 in Esophageal Epithelial Cells through Sterol Responsive Element-Binding Protein

PubMed Central

Prade, Elke; Tobiasch, Moritz; Hitkova, Ivana; Schäffer, Isabell; Lian, Fan; Xing, Xiangbin; Tänzer, Marc; Rauser, Sandra; Walch, Axel; Feith, Marcus; Post, Stefan; Röcken, Christoph; Schmid, Roland M.; Ebert, Matthias P.A.

2012-01-01

Bile acids are synthesized from cholesterol and are major risk factors for Barrett adenocarcinoma (BAC) of the esophagus. Caveolin-1 (Cav1), a scaffold protein of membrane caveolae, is transcriptionally regulated by cholesterol via sterol-responsive element-binding protein-1 (SREBP1). Cav1 protects squamous epithelia by controlling cell growth and stabilizing cell junctions and matrix adhesion. Cav1 is frequently down-regulated in human cancers; however, the molecular mechanisms that lead to this event are unknown. We show that the basal layer of the nonneoplastic human esophageal squamous epithelium expressed Cav1 mainly at intercellular junctions. In contrast, Cav1 was lost in 95% of tissue specimens from BAC patients (n = 100). A strong cytoplasmic expression of Cav1 correlated with poor survival in a small subgroup (n = 5) of BAC patients, and stable expression of an oncogenic Cav1 variant (Cav1-P132L) in the human BAC cell line OE19 promoted proliferation. Cav1 was also detectable in immortalized human squamous epithelial, Barrett esophagus (CPC), and squamous cell carcinoma cells (OE21), but was low in BAC cell lines (OE19, OE33). Mechanistically, bile acids down-regulated Cav1 expression by inhibition of the proteolytic cleavage of 125-kDa pre-SREBP1 from the endoplasmic reticulum/Golgi apparatus and nuclear translocation of active 68-kDa SREBP1. This block in SREBP1's posttranslational processing impaired transcriptional activation of SREBP1 response elements in the proximal human Cav1 promoter. Cav1 was also down-regulated in esophagi from C57BL/6 mice on a diet enriched with 1% (wt/wt) chenodeoxycholic acid. Mice deficient for Cav1 or the nuclear bile acid receptor farnesoid X receptor showed hyperplasia and hyperkeratosis of the basal cell layer of esophageal epithelia, respectively. These data indicate that bile acid-mediated down-regulation of Cav1 marks early changes in the squamous epithelium, which may contribute to onset of Barrett esophagus metaplasia and progression to BAC. PMID:22474125

Effect of monoclonal antibodies (MoAb) to class I and class II HLA antigens on lectin- and MoAb OKT3-induced lymphocyte proliferation.

PubMed

Akiyama, Y; Zicht, R; Ferrone, S; Bonnard, G D; Herberman, R B

1985-04-01

We have examined the effect of several monoclonal antibodies (MoAb) to monomorphic determinants of class II HLA antigens, and MoAb to monomorphic determinants of class I HLA antigens and to beta-2-microglobulin (beta 2-mu) on lectin- and MoAb OKT3-induced proliferation of human peripheral blood mononuclear cells (PBMNC) and cultured T cells (CTC). Some, but not all, anti-class II HLA MoAb inhibited the proliferative response of PBMNC to MoAb OKT3 and pokeweed mitogen (PWM). The degree of inhibitory effect varied considerably. This effect was not limited to anti-class II HLA MoAb since anti-class I HLA MoAb and anti-beta 2-mu MoAb also inhibited MoAb OKT3- or PWM-induced proliferative responses. In contrast, the response of PBMNC to phytohemagglutinin (PHA) and concanavalin A (Con A) was not blocked by any anti-class II HLA MoAb. However, some anti-class II HLA MoAb also inhibited the proliferative response of CTC plus allogeneic peripheral blood adherent accessory cells (AC) to PHA or Con A as well as to MoAb OKT3 or PWM. This may be attributable to the substantially greater class II HLA antigen expression by CTC than by fresh lymphocytes. Pretreatment of either CTC or AC with anti-class II HLA MoAb inhibited OKT3-induced proliferation. In contrast, pretreatment of CTC, but not AC, with anti-class I HLA MoAb inhibited the proliferative response of CTC to OKT3. Pretreatment of CTC with anti-class I HLA MoAb inhibited PHA-, Con A and PWM-induced proliferation, to a greater degree than the anti-class II HLA MoAb. It appears as if lymphocyte activation by different mitogens exhibits variable requirements for the presence of cells expressing major histocompatibility determinants. Binding of Ab to membrane markers may interfere with lymphocyte-AC cooperation, perhaps by inhibiting binding of mitogens to their receptors or by interfering with lymphocyte and AC function. We also have examined the role of class II HLA antigens on CTC by depleting class II HLA-positive cells. As expected, elimination of class II HLA-positive AC with anti-class II HLA MoAb plus complement caused a decrease in proliferation of CTC in response to all the mitogens tested. In contrast, elimination of class II HLA-positive CTC was shown to clearly increase proliferation of CTC, perhaps because this may deplete class II HLA-positive suppressor cells.

Identification and Characterization of MYC Regulatory Elements: Links to Prostate Cancer

DTIC Science & Technology

2011-06-01

cell proliferation and growth,MYC is up-regulated at both the mRNA and protein levels in aggressive prostate cancers ( DeMarzo et al. 2003). In...evolutionary synthesis: A genetic theory of morphological evolution. Cell 134: 25–36. DeMarzo AM, Nelson WG, Isaacs WB, Epstein JI. 2003. Pathological and

Onchocerciasis modulates the immune response to mycobacterial antigens

PubMed Central

Stewart, G R; Boussinesq, M; Coulson, T; Elson, L; Nutman, T; Bradley, J E

1999-01-01

Chronic helminth infection induces a type-2 cellular immune response. In contrast to this, mycobacterial infections commonly induce a type-1 immune response which is considered protective. Type-2 responses and diminished type-1 responses to mycobacteria have been previously correlated with active infection states such as pulmonary tuberculosis and lepromatous leprosy. The present study examines the immune responses of children exposed to both the helminth parasite Onchocerca volvulus and the mycobacterial infections, Mycobacterium tuberculosis and M. leprae. Proliferation of peripheral blood mononuclear cells (PBMC) and production of IL-4 in response to both helminth and mycobacterial antigen (PPD) decreased dramatically with increasing microfilarial (MF) density. Although interferon-gamma (IFN-γ) production strongly correlated with cellular proliferation, it was surprisingly not related to MF density for either antigen. IL-4 production in response to helminth antigen and PPD increased with ascending children's age. IFN-γ and cellular proliferation to PPD were not related to age, but in response to helminth antigen were significantly higher in children of age 9–12 years than children of either the younger age group (5–8 years) or the older group (13–16 years). Thus, there was a MF density-related down-regulation of cellular responsiveness and age-related skewing toward type 2 which was paralleled in response to both the helminth antigen and PPD. This parasite-induced immunomodulation of the response to mycobacteria correlates with a previous report of doubled incidence of lepromatous leprosy in onchocerciasis hyperendemic regions. Moreover, this demonstration that helminth infection in humans can modulate the immune response to a concurrent infection or immunological challenge is of critical importance to future vaccination strategies. PMID:10469056

Transposable element evolution in the allotetraploid Capsella bursa-pastoris.

PubMed

Ågren, J Arvid; Huang, Hui-Run; Wright, Stephen I

2016-07-01

Shifts in ploidy affect the evolutionary dynamics of genomes in a myriad of ways. Population genetic theory predicts that transposable element (TE) proliferation may follow because the genomewide efficacy of selection should be reduced and the increase in gene copies may mask the deleterious effects of TE insertions. Moreover, in allopolyploids, TEs may further accumulate because of hybrid breakdown of TE silencing. However, to date the evidence of TE proliferation following an increase in ploidy is mixed, and the relative importance of relaxed selection vs. silencing breakdown remains unclear. We used high-coverage whole-genome sequence data to evaluate the abundance, genomic distribution, and population frequencies of TEs in the self-fertilizing recent allotetraploid Capsella bursa-pastoris (Brassicaceae). We then compared the C. bursa-pastoris TE profile with that of its two parental diploid species, outcrossing C. grandiflora and self-fertilizing C. orientalis. We found no evidence that C. bursa-pastoris has experienced a large genomewide proliferation of TEs relative to its parental species. However, when centromeric regions are excluded, we found evidence of significantly higher abundance of retrotransposons in C. bursa-pastoris along the gene-rich chromosome arms compared with C. grandiflora and C. orientalis. The lack of a genomewide effect of allopolyploidy on TE abundance, combined with the increases TE abundance in gene-rich regions, suggests that relaxed selection rather than hybrid breakdown of host silencing explains the TE accumulation in C. bursa-pastoris. © 2016 Botanical Society of America.

Bursts of retrotransposition reproduced in Arabidopsis.

PubMed

Tsukahara, Sayuri; Kobayashi, Akie; Kawabe, Akira; Mathieu, Olivier; Miura, Asuka; Kakutani, Tetsuji

2009-09-17

Retrotransposons, which proliferate by reverse transcription of RNA intermediates, comprise a major portion of plant genomes. Plants often change the genome size and organization during evolution by rapid proliferation and deletion of long terminal repeat (LTR) retrotransposons. Precise transposon sequences throughout the Arabidopsis thaliana genome and the trans-acting mutations affecting epigenetic states make it an ideal model organism with which to study transposon dynamics. Here we report the mobilization of various families of endogenous A. thaliana LTR retrotransposons identified through genetic and genomic approaches with high-resolution genomic tiling arrays and mutants in the chromatin-remodelling gene DDM1 (DECREASE IN DNA METHYLATION 1). Using multiple lines of self-pollinated ddm1 mutant, we detected an increase in copy number, and verified this for various retrotransposons in a gypsy family (ATGP3) and copia families (ATCOPIA13, ATCOPIA21, ATCOPIA93), and also for a DNA transposon of a Mutator family, VANDAL21. A burst of retrotransposition occurred stochastically and independently for each element, suggesting an additional autocatalytic process. Furthermore, comparison of the identified LTR retrotransposons in related Arabidopsis species revealed that a lineage-specific burst of retrotransposition of these elements did indeed occur in natural Arabidopsis populations. The recent burst of retrotransposition in natural population is targeted to centromeric repeats, which is presumably less harmful than insertion into genes. The ddm1-induced retrotransposon proliferations and genome rearrangements mimic the transposon-mediated genome dynamics during evolution and provide experimental systems with which to investigate the controlling molecular factors directly.

The MADS-box XAANTAL1 increases proliferation at the Arabidopsis root stem-cell niche and participates in transition to differentiation by regulating cell-cycle components

PubMed Central

García-Cruz, Karla V.; García-Ponce, Berenice; Garay-Arroyo, Adriana; Sanchez, María De La Paz; Ugartechea-Chirino, Yamel; Desvoyes, Bénédicte; Pacheco-Escobedo, Mario A.; Tapia-López, Rosalinda; Ransom-Rodríguez, Ivan; Gutierrez, Crisanto; Alvarez-Buylla, Elena R.

2016-01-01

Background Morphogenesis depends on the concerted modulation of cell proliferation and differentiation. Such modulation is dynamically adjusted in response to various external and internal signals via complex transcriptional regulatory networks that mediate between such signals and regulation of cell-cycle and cellular responses (proliferation, growth, differentiation). In plants, which are sessile, the proliferation/differentiation balance is plastically adjusted during their life cycle and transcriptional networks are important in this process. MADS-box genes are key developmental regulators in eukaryotes, but their role in cell proliferation and differentiation modulation in plants remains poorly studied. Methods We characterize the XAL1 loss-of-function xal1-2 allele and overexpression lines using quantitative cellular and cytometry analyses to explore its role in cell cycle, proliferation, stem-cell patterning and transition to differentiation. We used quantitative PCR and cellular markers to explore if XAL1 regulates cell-cycle components and PLETHORA1 (PLT1) gene expression, as well as confocal microscopy to analyse stem-cell niche organization. Key Results We previously showed that XAANTAL1 (XAL1/AGL12) is necessary for Arabidopsis root development as a promoter of cell proliferation in the root apical meristem. Here, we demonstrate that XAL1 positively regulates the expression of PLT1 and important components of the cell cycle: CYCD3;1, CYCA2;3, CYCB1;1, CDKB1;1 and CDT1a. In addition, we show that xal1-2 mutant plants have a premature transition to differentiation with root hairs appearing closer to the root tip, while endoreplication in these plants is partially compromised. Coincidently, the final size of cortex cells in the mutant is shorter than wild-type cells. Finally, XAL1 overexpression-lines corroborate that this transcription factor is able to promote cell proliferation at the stem-cell niche. Conclusion XAL1 seems to be an important component of the networks that modulate cell proliferation/differentiation transition and stem-cell proliferation during Arabidopsis root development; it also regulates several cell-cycle components. PMID:27474508

Organization of cis-acting regulatory elements in osmotic- and cold-stress-responsive promoters.

PubMed

Yamaguchi-Shinozaki, Kazuko; Shinozaki, Kazuo

2005-02-01

cis-Acting regulatory elements are important molecular switches involved in the transcriptional regulation of a dynamic network of gene activities controlling various biological processes, including abiotic stress responses, hormone responses and developmental processes. In particular, understanding regulatory gene networks in stress response cascades depends on successful functional analyses of cis-acting elements. The ever-improving accuracy of transcriptome expression profiling has led to the identification of various combinations of cis-acting elements in the promoter regions of stress-inducible genes involved in stress and hormone responses. Here we discuss major cis-acting elements, such as the ABA-responsive element (ABRE) and the dehydration-responsive element/C-repeat (DRE/CRT), that are a vital part of ABA-dependent and ABA-independent gene expression in osmotic and cold stress responses.

Regulation of human bone sialoprotein gene transcription by platelet-derived growth factor-BB.

PubMed

Mezawa, Masaru; Araki, Shouta; Takai, Hideki; Sasaki, Yoko; Wang, Shuang; Li, Xinyue; Kim, Dong-Soon; Nakayama, Youhei; Ogata, Yorimasa

2009-04-15

Platelet-derived growth factor (PDGF) is produced by mesenchymal cells and released by platelets following aggregation and is synthesized by osteoblasts. In bone, PDGF stimulates proliferation and differentiation of osteoblasts. PDGF also increases bone resorption, most likely by increasing the number of osteoclasts. Bone sialoprotein (BSP) is thought to function in the initial mineralization of bone, selectively expressed by differentiated osteoblast. To determine the molecular mechanisms PDGF regulation of human BSP gene transcription, we have analyzed the effects of PDGF-BB on osteoblast-like Saos2 and ROS17/2.8 cells. PDGF-BB (5 ng/ml) increased BSP mRNA and protein levels at 12 h in Saos2 cells, and induced BSP mRNA expression at 3 h, reached maximal at 12 h in ROS17/2.8 cells. Transient transfection analyses were performed using chimeric constructs of the human BSP gene promoter linked to a luciferase reporter gene. Treatment of Saos2 cells with PDGF-BB (5 ng/ml, 12 h) increased luciferase activities of all constructs between -184LUC to -2672LUC including the human BSP gene promoter. Effects of PDGF-BB abrogated in constructs included 2 bp mutations in the two cAMP response elements (CRE1 and CRE2), activator protein 1(3) (AP1(3)) and shear stress response element 1 (SSRE1). Luciferase activities induced by PDGF-BB were blocked by protein kinase A inhibitor H89 and tyrosine kinase inhibitor herbimycin A. Gel mobility shift analyses showed that PDGF-BB increased binding of CRE1, CRE2, AP1(3) and SSRE1 elements. CRE1- and CRE2-protein complexes were supershifted by CREB1 and phospho-CREB1 antibodies. Notably, AP1(3)-protein complexes were supershifted by c-Fos and JunD, and disrupted by CREB1, phospho-CREB1, c-Jun and Fra2 antibodies. These studies, therefore, demonstrate that PDGF-BB stimulates human BSP transcription by targeting the CRE1, CRE2, AP1(3) and SSRE1 elements in the human BSP gene promoter.

Higher Molecular Weight Polyethylene Glycol Increases Cell Proliferation While Improving Barrier Function in an In Vitro Colon Cancer Model

PubMed Central

Bharadwaj, Shruthi; Vishnubhotla, Ramana; Shan, Sun; Chauhan, Chinmay; Cho, Michael; Glover, Sarah C.

2011-01-01

Polyethylene glycol (PEG) has been previously shown to protect against enteric pathogens and prevent colon cancer invasion. To determine if PEG could indeed protect against previously observed pro-invasive effects of commensal E. coli and EPEC, Caco-2 cells grown in an in vitro model of colon cancer were infected with strains of human commensal E. coli or EPEC and treated with 10% PEG 3350, PEG 8000, and PEG 20,000, respectively. At 24 hours after infection, MMP-1 and MMP-13 activities, cell cluster thickness, depth of invasion, and proliferation were determined using standard molecular biology techniques and advanced imaging. We found that higher molecular weight PEG, especially PEG 8000 and 20,000, regardless of bacterial infection, increased proliferation and depth of invasion although a decrease in cellular density and MMP-1 activity was also noted. Maximum proliferation and depth of invasion of Caco-2 cells was observed in scaffolds treated with a combination of commensal E. coli strain, HS4 and PEG 8000. In conclusion, we found that PEG 8000 increased cell proliferation and led to the preservation of cell density in cells treated with commensal bacteria. This is important, because the preservation of a proliferative response in colon cancer results in a more chemo-responsive tumor. PMID:21976966

Higher molecular weight polyethylene glycol increases cell proliferation while improving barrier function in an in vitro colon cancer model.

PubMed

Bharadwaj, Shruthi; Vishnubhotla, Ramana; Shan, Sun; Chauhan, Chinmay; Cho, Michael; Glover, Sarah C

2011-01-01

Polyethylene glycol (PEG) has been previously shown to protect against enteric pathogens and prevent colon cancer invasion. To determine if PEG could indeed protect against previously observed pro-invasive effects of commensal E. coli and EPEC, Caco-2 cells grown in an in vitro model of colon cancer were infected with strains of human commensal E. coli or EPEC and treated with 10% PEG 3350, PEG 8000, and PEG 20,000, respectively. At 24 hours after infection, MMP-1 and MMP-13 activities, cell cluster thickness, depth of invasion, and proliferation were determined using standard molecular biology techniques and advanced imaging. We found that higher molecular weight PEG, especially PEG 8000 and 20,000, regardless of bacterial infection, increased proliferation and depth of invasion although a decrease in cellular density and MMP-1 activity was also noted. Maximum proliferation and depth of invasion of Caco-2 cells was observed in scaffolds treated with a combination of commensal E. coli strain, HS4 and PEG 8000. In conclusion, we found that PEG 8000 increased cell proliferation and led to the preservation of cell density in cells treated with commensal bacteria. This is important, because the preservation of a proliferative response in colon cancer results in a more chemo-responsive tumor.

Wnt/β-catenin signaling directs the regional expansion of first and second heart field-derived ventricular cardiomyocytes

PubMed Central

Buikema, Jan Willem; Mady, Ahmed S.; Mittal, Nikhil V.; Atmanli, Ayhan; Caron, Leslie; Doevendans, Pieter A.; Sluijter, Joost P. G.; Domian, Ibrahim J.

2013-01-01

In mammals, cardiac development proceeds from the formation of the linear heart tube, through complex looping and septation, all the while increasing in mass to provide the oxygen delivery demands of embryonic growth. The developing heart must orchestrate regional differences in cardiomyocyte proliferation to control cardiac morphogenesis. During ventricular wall formation, the compact myocardium proliferates more vigorously than the trabecular myocardium, but the mechanisms controlling such regional differences among cardiomyocyte populations are not understood. Control of definitive cardiomyocyte proliferation is of great importance for application to regenerative cell-based therapies. We have used murine and human pluripotent stem cell systems to demonstrate that, during in vitro cellular differentiation, early ventricular cardiac myocytes display a robust proliferative response to β-catenin-mediated signaling and conversely accelerate differentiation in response to inhibition of this pathway. Using gain- and loss-of-function murine genetic models, we show that β-catenin controls ventricular myocyte proliferation during development and the perinatal period. We further demonstrate that the differential activation of the Wnt/β-catenin signaling pathway accounts for the observed differences in the proliferation rates of the compact versus the trabecular myocardium during normal cardiac development. Collectively, these results provide a mechanistic explanation for the differences in localized proliferation rates of cardiac myocytes and point to a practical method for the generation of the large numbers of stem cell-derived cardiac myocytes necessary for clinical applications. PMID:24026118

Mesenchymal stem cells induce dermal fibroblast responses to injury

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, Andria N., E-mail: snosmith@u.washington.edu; Willis, Elise, E-mail: elise.willis@gmail.com; Chan, Vincent T.

2010-01-01

Although bone marrow-derived mesenchymal stem cells have been shown to promote repair when applied to cutaneous wounds, the mechanism for this response remains to be determined. The aim of this study was to determine the effects of paracrine signaling from mesenchymal stem cells on dermal fibroblast responses to injury including proliferation, migration and expression of genes important in wound repair. Dermal fibroblasts were co-cultured with bone marrow-derived mesenchymal stem cells grown in inserts, which allowed for paracrine interactions without direct cell contact. In this co-culture model, bone marrow-derived mesenchymal stem cells regulate dermal fibroblast proliferation, migration and gene expression. Whenmore » co-cultured with mesenchymal stem cells, dermal fibroblasts show increased proliferation and accelerated migration in a scratch assay. A chemotaxis assay also demonstrated that dermal fibroblasts migrate towards bone marrow-derived mesenchymal stem cells. A PCR array was used to analyze the effect of mesenchymal stem cells on dermal fibroblast gene expression. In response to mesenchymal stem cells, dermal fibroblasts up-regulate integrin alpha 7 expression and down-regulate expression of ICAM1, VCAM1 and MMP11. These observations suggest that mesenchymal stem cells may provide an important early signal for dermal fibroblast responses to cutaneous injury.« less

Effect of Porosity of Alumina and Zirconia Ceramics toward Pre-Osteoblast Response

PubMed Central

Hadjicharalambous, Chrystalleni; Prymak, Oleg; Loza, Kateryna; Buyakov, Ales; Kulkov, Sergei; Chatzinikolaidou, Maria

2015-01-01

It is acknowledged that cellular responses are highly affected by biomaterial porosity. The investigation of this effect is important for the development of implanted biomaterials that integrate with bone tissue. Zirconia and alumina ceramics exhibit outstanding mechanical properties and are among the most popular implant materials used in orthopedics, but few data exist regarding the effect of porosity on cellular responses to these materials. The present study investigates the effect of porosity on the attachment and proliferation of pre-osteoblastic cells on zirconia and alumina. For each composition, ceramics of three different porosities are fabricated by sintering, and characterized using scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray powder diffraction. Cell proliferation is quantified, and microscopy is employed to qualitatively support the proliferation results and evaluate cell morphology. Cell adhesion and metabolic activity are found comparable among low porosity zirconia and alumina. In contrast, higher porosity favors better cell spreading on zirconia and improves growth, but does not significantly affect cell response on alumina. Between the highest porosity materials, cell response on zirconia is found superior to alumina. Results show that an average pore size of ~150 μm and ~50% porosity can be considered beneficial to cellular growth on zirconia ceramics. PMID:26579516

Radiation effect of neutrons produced by D-D side reactions on a D-3He fusion reactor

NASA Astrophysics Data System (ADS)

Bahmani, J.

2017-04-01

One of the most important characteristics in D-3He fusion reactors is neutron production via D-D side reactions. The neutrons can activate structural material, degrading them and ultimately converting them into high-level radioactive waste, while it is really costly and difficult to remove them. The neutrons from a fusion reactor could also be used to make weapons-grade nuclear material, rendering such types of fusion reactors a serious proliferation hazard. A related problem is the presence of radioactive elements such as tritium in D-3He plasma, either as fuel for or as products of the nuclear reactions; substantial quantities of radioactive elements would not only pose a general health risk, but tritium in particular would also be another proliferation hazard. The problems of neutron radiation and radioactive element production are especially interconnected because both would result from the D-D side reaction. Therefore, the presentation approach for reducing neutrons via D-D nuclear side reactions in a D-3He fusion reactor is very important. For doing this research, energy losses and neutron power fraction in D-3He fusion reactors are investigated. Calculations show neutrons produced by the D-D nuclear side reaction could be reduced by changing to a more 3He-rich fuel mixture, but then the bremsstrahlung power loss fraction would increase in the D-3He fusion reactor.

A tumor-promoting mechanism mediated by retrotransposon-encoded reverse transcriptase is active in human transformed cell lines

PubMed Central

Sciamanna, Ilaria; Gualtieri, Alberto; Cossetti, Cristina; Osimo, Emanuele Felice; Ferracin, Manuela; Macchia, Gianfranco; Aricò, Eleonora; Prosseda, Gianni; Vitullo, Patrizia; Misteli, Tom; Spadafora, Corrado

2013-01-01

LINE-1 elements make up the most abundant retrotransposon family in the human genome. Full-length LINE-1 elements encode a reverse transcriptase (RT) activity required for their own retrotranpsosition as well as that of non-autonomous Alu elements. LINE-1 are poorly expressed in normal cells and abundantly in cancer cells. Decreasing RT activity in cancer cells, by either LINE-1-specific RNA interference, or by RT inhibitory drugs, was previously found to reduce proliferation and promote differentiation and to antagonize tumor growth in animal models. Here we have investigated how RT exerts these global regulatory functions. We report that the RT inhibitor efavirenz (EFV) selectively downregulates proliferation of transformed cell lines, while exerting only mild effects on non-transformed cells; this differential sensitivity matches a differential RT abundance, which is high in the former and undetectable in the latter. Using CsCl density gradients, we selectively identify Alu and LINE-1 containing DNA:RNA hybrid molecules in cancer but not in normal cells. Remarkably, hybrid molecules fail to form in tumor cells treated with EFV under the same conditions that repress proliferation and induce the reprogramming of expression profiles of coding genes, microRNAs (miRNAs) and ultraconserved regions (UCRs). The RT-sensitive miRNAs and UCRs are significantly associated with Alu sequences. The results suggest that LINE-1-encoded RT governs the balance between single-stranded and double-stranded RNA production. In cancer cells the abundant RT reverse-transcribes retroelement-derived mRNAs forming RNA:DNA hybrids. We propose that this impairs the formation of double-stranded RNAs and the ensuing production of small regulatory RNAs, with a direct impact on gene expression. RT inhibition restores the ‘normal’ small RNA profile and the regulatory networks that depend on them. Thus, the retrotransposon-encoded RT drives a previously unrecognized mechanism crucial to the transformed state in tumor cells. PMID:24345856

Cell Proliferation in Neuroblastoma

PubMed Central

Stafman, Laura L.; Beierle, Elizabeth A.

2016-01-01

Neuroblastoma, the most common extracranial solid tumor of childhood, continues to carry a dismal prognosis for children diagnosed with advanced stage or relapsed disease. This review focuses upon factors responsible for cell proliferation in neuroblastoma including transcription factors, kinases, and regulators of the cell cycle. Novel therapeutic strategies directed toward these targets in neuroblastoma are discussed. PMID:26771642

Ectopic expression of Msx-2 in posterior limb bud mesoderm impairs limb morphogenesis while inducing BMP-4 expression, inhibiting cell proliferation, and promoting apoptosis.

PubMed

Ferrari, D; Lichtler, A C; Pan, Z Z; Dealy, C N; Upholt, W B; Kosher, R A

1998-05-01

During early stages of chick limb development, the homeobox-containing gene Msx-2 is expressed in the mesoderm at the anterior margin of the limb bud and in a discrete group of mesodermal cells at the midproximal posterior margin. These domains of Msx-2 expression roughly demarcate the anterior and posterior boundaries of the progress zone, the highly proliferating posterior mesodermal cells underneath the apical ectodermal ridge (AER) that give rise to the skeletal elements of the limb and associated structures. Later in development as the AER loses its activity, Msx-2 expression expands into the distal mesoderm and subsequently into the interdigital mesenchyme which demarcates the developing digits. The domains of Msx-2 expression exhibit considerably less proliferation than the cells of the progress zone and also encompass several regions of programmed cell death including the anterior and posterior necrotic zones and interdigital mesenchyme. We have thus suggested that Msx-2 may be in a regulatory network that delimits the progress zone by suppressing the morphogenesis of the regions of the limb mesoderm in which it is highly expressed. In the present study we show that ectopic expression of Msx-2 via a retroviral expression vector in the posterior mesoderm of the progress zone from the time of initial formation of the limb bud severely impairs limb morphogenesis. Msx-2-infected limbs are typically very narrow along the anteroposterior axis, are occasionally truncated, and exhibit alterations in the pattern of formation of skeletal elements, indicating that as a consequence of ectopic Msx-2 expression the morphogenesis of large portions of the posterior mesoderm has been suppressed. We further show that Msx-2 impairs limb morphogenesis by reducing cell proliferation and promoting apoptosis in the regions of the posterior mesoderm in which it is ectopically expressed. The domains of ectopic Msx-2 expression in the posterior mesoderm also exhibit ectopic expression of BMP-4, a secreted signaling molecule that is coexpressed with Msx-2 during normal limb development in the anterior limb mesoderm, the posterior necrotic zone, and interdigital mesenchyme. This indicates that Msx-2 regulates BMP-4 expression and that the suppressive effects of Msx-2 on limb morphogenesis might be mediated in part by BMP-4. These studies indicate that during normal limb development Msx-2 is a key component of a regulatory network that delimits the boundaries of the progress zone by suppressing the morphogenesis of the regions of the limb mesoderm in which it is highly expressed, thus restricting the outgrowth and formation of skeletal elements and associated structures to the progress zone. We also report that rather large numbers of apoptotic cells as well as proliferating cells are present throughout the AER during all stages of normal limb development we have examined, indicating that many of the cells of the AER are continuously undergoing programmed cell death at the same time that new AER cells are being generated by cell proliferation. Thus, a balance between cell proliferation and programmed cell death may play a very important role in maintaining the activity of the AER. Copyright 1998 Academic Press.

Cyclic GMP-AMP Synthase Is Required for Cell Proliferation and Inflammatory Responses in Rheumatoid Arthritis Synoviocytes.

PubMed

Wang, Yan; Su, Guo-Hua; Zhang, Fang; Chu, Jing-Xue; Wang, Yun-Shan

2015-01-01

Rheumatoid arthritis (RA) is characterized by inflammatory cell infiltration, fibroblast-like synoviocytes (FLS) invasive proliferation, and joint destruction. Cyclic GMP-AMP synthase (cGAS) is a cytosolic DNA sensor that induces immune activation. In this study, we examined whether cGAS plays a role in RA FLS. In this study, cGAS was overexpressed in RA-FLS compared with OA FLS. TNFα stimulation induced cGAS expression in RA FLS. Overexpression of cGAS promoted the proliferation and knockdown of cGAS inhibited the proliferation of RA FLS. cGAS overexpression enhanced the production of proinflammatory cytokines and matrix metalloproteinases (MMPs) as well as AKT and ERK phosphorylation in TNFα-stimulated FLS. In contrast, cGAS silencing inhibited production of proinflammatory cytokines and matrix metalloproteinases (MMPs) as well as AKT and ERK phosphorylation in TNFα-stimulated FLS. These results suggest that cGAS activates the AKT and ERK pathways to promote the inflammatory response of RA FLS, and the development of strategies targeting cGAS may have therapeutic potential for human RA.

Xanthine-Catechin Mixture Enhances Lithium-Induced Anti-Inflammatory Response in Activated Macrophages In Vitro

PubMed Central

Barbisan, Fernanda; Azzolin, Verônica Farina; Teixeira, Cibele Ferreira; Mastella, Moisés Henrique; Ribeiro, Euler Esteves; do Prado-Lima, Pedro Antonio Schmidt; Praia, Raquel de Souza; Medeiros Frescura Duarte, Marta Maria

2017-01-01

Lithium (Li) is a chemical element used for treating and preventing bipolar disorder (BD) and exerts positive effects such as anti-inflammatory effects as well as undesirable side effects. These effects of Li can be influenced by interaction with some nutritional elements. Therefore, we investigated the potential effects of xanthine (caffeine and theobromine) and catechin molecules present in some food beverages broadly consumed worldwide, such as coffee and tea, on Li-induced anti-inflammatory effects. In the present study, we concomitantly exposed RAW 264.7 macrophages to Li, isolated xanthine and catechin molecules, and a xanthine-catechin mixture (XC mixture). We evaluated the effects of these treatments on cell proliferation, cell cycle progression, oxidative and antioxidant marker expression, cytokine levels, gene expression, and GSK-3β enzyme expression. Treatment with the XC mixture potentialized Li-induced anti-inflammatory effects by intensification of the following: GSK-3β inhibitory action, lowering effect on proinflammatory cytokines (IL-1β, IL-6, and TNFα), and increase in the levels of IL-10 that is an anti-inflammatory cytokine. Despite the controversial nature of caffeine consumption by BD patients, these results suggested that consumption of caffeine, in low concentrations, mixed with other bioactive molecules along with Li may be safe. PMID:29250539

Specific TRPC6 Channel Activation, a Novel Approach to Stimulate Keratinocyte Differentiation*S⃞

PubMed Central

Müller, Margarethe; Essin, Kirill; Hill, Kerstin; Beschmann, Heike; Rubant, Simone; Schempp, Christoph M.; Gollasch, Maik; Boehncke, W. Henning; Harteneck, Christian; Müller, Walter E.; Leuner, Kristina

2008-01-01

The protective epithelial barrier in our skin undergoes constant regulation, whereby the balance between differentiation and proliferation of keratinocytes plays a major role. Impaired keratinocyte differentiation and proliferation are key elements in the pathophysiology of several important dermatological diseases, including atopic dermatitis and psoriasis. Ca2+ influx plays an essential role in this process presumably mediated by different transient receptor potential (TRP) channels. However, investigating their individual role was hampered by the lack of specific stimulators or inhibitors. Because we have recently identified hyperforin as a specific TRPC6 activator, we investigated the contribution of TRPC6 to keratinocyte differentiation and proliferation. Like the endogenous differentiation stimulus high extracellular Ca2+ concentration ([Ca2+]o), hyperforin triggers differentiation in HaCaT cells and in primary cultures of human keratinocytes by inducing Ca2+ influx via TRPC6 channels and additional inhibition of proliferation. Knocking down TRPC6 channels prevents the induction of Ca2+- and hyperforin-induced differentiation. Importantly, TRPC6 activation is sufficient to induce keratinocyte differentiation similar to the physiological stimulus [Ca2+]o. Therefore, TRPC6 activation by hyperforin may represent a new innovative therapeutic strategy in skin disorders characterized by altered keratinocyte differentiation. PMID:18818211

Associations of cord blood fatty acids with lymphocyte proliferation, IL-13, and IFN-γ

PubMed Central

Gold, Diane R.; Willwerth, Ben M.; Tantisira, Kelan G.; Finn, Patricia W.; Schaub, Bianca; Perkins, David L.; Tzianabos, Arthur; Ly, Ngoc P.; Schroeter, Christian; Gibbons, Fiona; Campos, Hannia; Oken, Emily; Gillman, Matthew W.; Palmer, Lyle J.; Ryan, Louise M.; Weiss, Scott T.

2006-01-01

Background. N-3 and n-6 polyunsaturated fatty acids (PUFAs) have been hypothesized to have opposing influences on neonatal immune responses that might influence the risk of allergy or asthma. However, both n-3 eicosapentaenoic acid (EPA) and n-6 arachidonic acid (AA) are required for normal fetal development. Objective. We evaluated whether cord blood fatty acid levels were related to neonatal immune responses and whether n-3 and n-6 PUFA responses differed. Methods. We examined the relation of cord blood plasma n-3 and n-6 PUFAs (n = 192) to antigen- and mitogen-stimulated cord blood lymphocyte proliferation (n = 191) and cytokine (IL-13 and IFN-γ; n = 167) secretion in a US birth cohort. Results. Higher levels of n-6 linoleic acid were correlated with higher IL-13 levels in response to Bla g 2 (cockroach, P = .009) and Der f 1 (dust mite, P = .02). Higher n-3 EPA and n-6 AA levels were each correlated with reduced lymphocyte proliferation and IFN-γ levels in response to Bla g 2 and Der f 1 stimulation. Controlling for potential confounders, EPA and AA had similar independent effects on reduced allergen-stimulated IFN-γ levels. If neonates had either EPA or AA levels in the highest quartile, their Der f 1 IFN-γ levels were 90% lower (P = .0001) than those with both EPA and AA levels in the lowest 3 quartiles. Reduced AA/EPA ratio was associated with reduced allergen-stimulated IFN-γ level. Conclusion. Increased levels of fetal n-3 EPA and n-6 AA might have similar effects on attenuation of cord blood lymphocyte proliferation and IFN-γ secretion. Clinical implications. The implications of these findings for PMID:16630954

Seagrass Proliferation Precedes Mortality during Hypo-Salinity Events: A Stress-Induced Morphometric Response

PubMed Central

Collier, Catherine J.; Villacorta-Rath, Cecilia; van Dijk, Kor-jent; Takahashi, Miwa; Waycott, Michelle

2014-01-01

Halophytes, such as seagrasses, predominantly form habitats in coastal and estuarine areas. These habitats can be seasonally exposed to hypo-salinity events during watershed runoff exposing them to dramatic salinity shifts and osmotic shock. The manifestation of this osmotic shock on seagrass morphology and phenology was tested in three Indo-Pacific seagrass species, Halophila ovalis, Halodule uninervis and Zostera muelleri, to hypo-salinity ranging from 3 to 36 PSU at 3 PSU increments for 10 weeks. All three species had broad salinity tolerance but demonstrated a moderate hypo-salinity stress response – analogous to a stress induced morphometric response (SIMR). Shoot proliferation occurred at salinities <30 PSU, with the largest increases, up to 400% increase in shoot density, occurring at the sub-lethal salinities <15 PSU, with the specific salinity associated with peak shoot density being variable among species. Resources were not diverted away from leaf growth or shoot development to support the new shoot production. However, at sub-lethal salinities where shoots proliferated, flowering was severely reduced for H. ovalis, the only species to flower during this experiment, demonstrating a diversion of resources away from sexual reproduction to support the investment in new shoots. This SIMR response preceded mortality, which occurred at 3 PSU for H. ovalis and 6 PSU for H. uninervis, while complete mortality was not reached for Z. muelleri. This is the first study to identify a SIMR in seagrasses, being detectable due to the fine resolution of salinity treatments tested. The detection of SIMR demonstrates the need for caution in interpreting in-situ changes in shoot density as shoot proliferation could be interpreted as a healthy or positive plant response to environmental conditions, when in fact it could signal pre-mortality stress. PMID:24705377

Identification of coeliac disease triggering glutenin peptides in adults.

PubMed

Donnelly, Suzanne C; Šuligoj, Tanja; Ellis, H Julia; Ciclitira, Paul J

2016-07-01

Coeliac disease affects approximately 1% of Northern American and European populations. It is caused by an inappropriate immune response to dietary gluten. Gluten comprises of two major protein fractions: gliadins and glutenins. Glutenins have recently been found to be toxic to coeliac individuals. Proliferation assays suggest in some but not all paediatric coeliac individuals there may be immunological stimulation with high molecular weight (HMW) glutenins. Less evidence pertains to low molecular weight (LMW) glutenins. The aim is to assess adaptive, T-cell driven, and innate immune response in adult coeliac individuals towards HMW glutenin peptide, glut04, and LMW glutenin peptide, glt156. Coeliac patients were recruited attending endoscopy for routine monitoring. Adaptive immune response towards glut04 and glt156 was measured by proliferation assays and measurement of interferon-γ secretion in 28 T-cell lines. The innate immune response was assessed by measurement of enterocyte cell height (ECH) in coeliac small intestinal biopsies following overnight incubation in organ culture chambers in a further nine individuals. There were 3/28 and 2/28 positive proliferation results using gluten-sensitive T-cells with glut04 and glt156, respectively. All coeliac biopsies tested in organ culture chambers demonstrated clear reduction in ECH with peptic-tryptic digest of whole industrial gluten, glut04 and glt156 when compared to negative control ovalbumin (p < 0.005). Three individuals had both T-cell and organ culture study data. Their proliferation assays showed no stimulation of the T-cells. This study demonstrates glutenin epitopes glut04 and glt156, while minor T-cell epitopes, are important in their ability to trigger the innate immune response.

Dendritic cells loaded with HeLa-derived exosomes simulate an antitumor immune response.

PubMed

Ren, Guoping; Wang, Yanhong; Yuan, Shexia; Wang, Baolian

2018-05-01

The aim of the present study was to investigate the effect of loading dendritic cells (DCs) with HeLa-derived exosomes on cytotoxic T-lymphocyte (CTL) responses, and the cytotoxic effects of CTL responses on the HeLa cell line. Ultrafiltration centrifugation combined with sucrose density gradient ultracentrifugation was applied to isolate exosomes (HeLa-exo) from the supernatant of HeLa cells. Morphological features of HeLa-exo were identified by transmission electron microscopy (TEM), and the expression of cluster of differentiation (CD)63 was detected by western blotting. Next, monocytes were isolated from peripheral blood and cultured with the removal of adherent cells to induce DC proliferation. DCs were then phenotypically characterized by flow cytometry. Finally, MTT assays were performed to analyze the effects of DCs loaded with HeLa-exo on T cell proliferation and cytotoxicity assays to evaluate the effect of CTL responses on HeLa cells. TEM revealed that HeLa-exo exhibit typical cup-shaped morphology with a diameter range of 30-100 nm. It was also identified that the CD63 surface antigen is expressed on HeLa-exo. Furthermore, monocyte-derived DCs were able to express CD1a, suggesting that DC induction was a success. DCs exhibited hair-like protrusions and other typical dendritic cell morphology. Furthermore, DCs loaded with HeLa-exo could enhance CTL proliferation and the cytotoxic activity of CTLs compared with DCs without HeLa-exo (P<0.05). In conclusion, DCs loaded with HeLa-exo may promote T cell proliferation and induce CTL responses to inhibit the growth of cervical cancer cells in vitro .

Differential expression and activation of a family of murine peroxisome proliferator-activated receptors.

PubMed Central

Kliewer, S A; Forman, B M; Blumberg, B; Ong, E S; Borgmeyer, U; Mangelsdorf, D J; Umesono, K; Evans, R M

1994-01-01

To gain insight into the function of peroxisome proliferator-activated receptor (PPAR) isoforms in mammals, we have cloned and characterized two PPAR alpha-related cDNAs (designated PPAR gamma and -delta, respectively) from mouse. The three PPAR isoforms display widely divergent patterns of expression during embryogenesis and in the adult. Surprisingly, PPAR gamma and -delta are not activated by pirinixic acid (Wy 14,643), a potent peroxisome proliferator and activator of PPAR alpha. However, PPAR gamma and -delta are activated by the structurally distinct peroxisome proliferator LY-171883 and linoleic acid, respectively, indicating that each of the isoforms can act as a regulated activator of transcription. These data suggest that tissue-specific responsiveness to peroxisome proliferators, including certain fatty acids, is in part a consequence of differential expression of multiple, pharmacologically distinct PPAR isoforms. Images PMID:8041794

In vitro blood and fibroblast responses to BisGMA-TEGDMA/bioactive glass composite implants.

PubMed

Abdulmajeed, Aous A; Kokkari, Anne K; Käpylä, Jarmo; Massera, Jonathan; Hupa, Leena; Vallittu, Pekka K; Närhi, Timo O

2014-01-01

This in vitro study was designed to evaluate both blood and human gingival fibroblast responses to bisphenol A-glycidyl methacrylate-triethyleneglycol dimethacrylate (BisGMA-TEGDMA)/bioactive glass (BAG) composite, aimed to be used as composite implant abutment surface modifier. Three different types of substrates were investigated: (a) plain polymer (BisGMA 50 wt%-TEGDMA 50 wt%), (b) BAG-composite (50 wt% polymer + 50 wt% fraction of BAG-particles, <50 μm), and (c) plain BAG plates (100 wt% BAG). The blood response, including the blood-clotting ability and platelet adhesion morphology were evaluated. Human gingival fibroblasts were plated and cultured on the experimental substrates for up to 10 days, then the cell proliferation rate was assessed using AlamarBlue assay™. The BAG-composite and plain BAG substrates had a shorter clotting time than plain polymer substrates. Platelet activation and aggregation were most extensive, qualitatively, on BAG-composite. Analysis of the normalized cell proliferation rate on the different surfaces showed some variations throughout the experiment, however, by day 10 the BAG-composite substrate showed the highest (P < 0.001) cell proliferation rate. In conclusion, the presence of exposed BAG-particles enhances fibroblast and blood responses on composite surfaces in vitro.

Human Gastric Mucins Differently Regulate Helicobacter pylori Proliferation, Gene Expression and Interactions with Host Cells

PubMed Central

Skoog, Emma C.; Sjöling, Åsa; Navabi, Nazanin; Holgersson, Jan; Lundin, Samuel B.; Lindén, Sara K.

2012-01-01

Helicobacter pylori colonizes the mucus niche of the gastric mucosa and is a risk factor for gastritis, ulcers and cancer. The main components of the mucus layer are heavily glycosylated mucins, to which H. pylori can adhere. Mucin glycosylation differs between individuals and changes during disease. Here we have examined the H. pylori response to purified mucins from a range of tumor and normal human gastric tissue samples. Our results demonstrate that mucins from different individuals differ in how they modulate both proliferation and gene expression of H. pylori. The mucin effect on proliferation varied significantly between samples, and ranged from stimulatory to inhibitory, depending on the type of mucins and the ability of the mucins to bind to H. pylori. Tumor-derived mucins and mucins from the surface mucosa had potential to stimulate proliferation, while gland-derived mucins tended to inhibit proliferation and mucins from healthy uninfected individuals showed little effect. Artificial glycoconjugates containing H. pylori ligands also modulated H. pylori proliferation, albeit to a lesser degree than human mucins. Expression of genes important for the pathogenicity of H. pylori (babA, sabA, cagA, flaA and ureA) appeared co-regulated in response to mucins. The addition of mucins to co-cultures of H. pylori and gastric epithelial cells protected the viability of the cells and modulated the cytokine production in a manner that differed between individuals, was partially dependent of adhesion of H. pylori to the gastric cells, but also revealed that other mucin factors in addition to adhesion are important for H. pylori-induced host signaling. The combined data reveal host-specific effects on proliferation, gene expression and virulence of H. pylori due to the gastric mucin environment, demonstrating a dynamic interplay between the bacterium and its host. PMID:22563496

Hypergravity Stimulates Osteoblast Proliferation Via Matrix-Integrin-Signaling Pathways

NASA Technical Reports Server (NTRS)

Vercoutere, W.; Parra, M.; Roden, C.; DaCosta, M.; Wing, A.; Damsky, C.; Holton, E.; Searby, N.; Globus, R.; Almeida, E.

2003-01-01

Extensive characterizations of the physiologic consequences of microgravity and gravity indicate that lack of weight-bearing may cause tissue atrophy through cellular and subcellular level mechanisms. We hypothesize that gravity is needed for the efficient transduction of cell growth and survival signals from the extra-cellular matrix (ECM) in mechanosensitive tissues. Recent work from our laboratory and from others shows that an increase of gravity increases bone cell growth and survival. We found that 50-g hypergravity stimulation increased osteoblast proliferation for cells grown on Collagen Type I and Fibronectin, but not on Laminin or uncoated plastic. This may be a tissue-specific response, because 50-g hypergravity stimulation caused no increase in proliferation for primary rat fibroblasts. These results combined with RT-PCR for all possible integrins indicate that beta1 integrin subunit may be involved. The osteoblast proliferation response on Collagen Type I was greater at 25-g than at 10-g or 50-g; 24-h duration of hypergravity was necessary to see an increase in proliferation. Survival was enhanced during hypergravity stimulation by the presence of matrix. Flow cytometry analysis indicated that cell cycle may be altered; BrdU incorporation in proliferating cells showed an increase in the number of actively dividing cells from about 60% at 1-g to over 90% at 25-g. To further investigate the molecular components involved, we applied fluorescence labeling of cytoskeletal and signaling molecules to cells after 2 to 30 minutes of hypergravity stimulation. While structural components did not appear to be altered, phosphorylation increased, indicating that signaling pathways may be activated. These data indicate that gravity mechanostimulation of osteoblast proliferation involves specific matrix-integrin signaling pathways which are sensitive to duration and g-level.

Near-infrared laser increases MDPC-23 odontoblast-like cells proliferation by activating redox sensitive pathways.

PubMed

Rizzi, Manuela; Migliario, Mario; Rocchetti, Vincenzo; Tonello, Stelvio; Renò, Filippo

2016-11-01

Near infrared laser is known to induce biostimulatory effects, resulting in cell proliferation enhancement. Although such positive effect is widely exploited in various clinical applications, molecular mechanisms involved are still poorly understood. The aim of the study was to investigate the ability of laser stimulation to increase cell proliferation through an early activation of three redox sensitive pathways, namely Nrf-2, NF-κB and ERK in a rat odontoblast-like cell line (MDPC-23 cells). MDPC-23 cells were irradiated with different energy settings (0-50J, corresponding to 0-32.47J/cm 2 ) and cell proliferation was evaluated by cell counting. Nrf-2, NF-κB and ERK signaling pathways activation was investigated through Western blot analysis. Our results show that a single 25J laser stimulation is able to increase cell proliferation and that this effect could be increased by repeating the stimulation twice with a time lapse of 24h. Western blot experiments demonstrated that laser stimulation is able to induce an early activation response in intracellular signaling, with an overlapping time pattern between the three considered pathways. Results discussed in this paper reveal a complex mechanism underlying near-infrared induced increase in pre-odontoblasts proliferation, involving three survival pathways that can act both separately or through reciprocal crosstalk. In particular, data presented suggest an important role for ERK pathway that could act directly by stimulating cell proliferation but can also induce both Nrf-2 and NF-κB activation, acting as a critical cellular checkpoint in response to imbalanced redox state generated by a laser induced increase in ROS production. Copyright © 2016 Elsevier B.V. All rights reserved.

REST, regulated by RA through miR-29a and the proteasome pathway, plays a crucial role in RPC proliferation and differentiation.

PubMed

Wang, Yuyao; Zhang, Dandan; Tang, Zhimin; Zhang, Yi; Gao, Huiqin; Ni, Ni; Shen, Bingqiao; Sun, Hao; Gu, Ping

2018-04-18

One of the primary obstacles in the application of retinal progenitor cells (RPCs) to the treatment of retinal degenerative diseases, such as age-related macular degeneration (AMD) and retinitis pigmentosa (RP), is their limited ability to proliferate and differentiate into specific retinal neurons. In this study, we revealed that repressor element-1-silencing transcription factor (REST), whose expression could be transcriptionally and post-transcriptionally mediated by retinoic acid (RA, one isomeride of a vitamin A derivative used as a differentiation-inducing agent in many disease treatments), plays a pivotal role in the regulation of proliferation and differentiation of RPCs. Our results show that direct knockdown of endogenous REST reduced RPC proliferation but accelerated RPC differentiation toward retinal neurons, which phenocopied the observed effects of RA on RPCs. Further studies disclosed that the expression level of REST could be downregulated by RA not only through upregulating microRNA (miR)-29a, which directly interacted with the 3'-untranslated region (3'-UTR) of the REST mRNA, but also through promoting REST proteasomal degradation. These results show us a novel functional protein, REST, which regulates RPC proliferation and differentiation, can be mediated by RA. Understanding the mechanisms of REST and RA in RPC fate determination enlightens a promising future for the application of REST and RA in the treatment of retinal degeneration diseases.

Dose-related cell proliferation in medaka (Oryzias latipes) after N-nitrosodiethylamine exposure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ortego, L.S.; Hawkins, W.E.; Walker, W.W.

1994-12-31

Cell proliferation is important in toxic and carcinogenic mechanisms. Carcinogens such as N-nitrosodiethylamine (DEN) that cause necrotizing injury stimulate cell proliferation as part of an injury-repair mechanism. A stimulus to cell division in an organ with a low rate of cell division, such as the liver, may initiate or enhance the carcinogenicity of a chemical. The authors examined the effect of DEN exposure on cell proliferation in the liver of medaka (Oryzias latipes). Two age groups (6 and 56 days post-hatch) were exposed to DEN continuously at 5 doses (0.0, 2.5, 5.0, 10.0, and 20.0 ppm) for 28 days. Cellmore » proliferation was measured using the proliferating cell nuclear antigen (PCNA) assay two months post-initiation of DEN exposure. The assay involves monoclonal antibody detection of PCNA, an auxiliary protein of DNA polymerase delta which is, expressed during cell division. Results suggested that cell proliferation paralleled the DEN dose and that age at initiation of exposure did not affect this relationship. The increase in cell proliferation appeared to be a sustained response from that initiated during DEN exposure. The study suggests that cell proliferation in medaka is an important component in carcinogenesis and is related to carcinogen exposure dose.« less

Role of interleukin 1 in antigen-specific T cell proliferation.

PubMed

Chu, E; Rosenwasser, L J; Dinarello, C A; Lareau, M; Geha, R S

1984-03-01

The role of interleukin 1 (IL 1) in human antigen-specific T cell proliferation was examined. Nylon wool-purified T cells proliferated in the presence of autologous monocytes (Mo.) pulsed for 18 h with tetanus toxoid (TT) antigen (Mo.TT). Irradiation of Mo.TT with ultraviolet (UV) light (72 J/m2) abolished their capacity to support T cell proliferation and drastically reduced their capacity to secrete IL 1 after stimulation with Staphylococcus albus. The defect in antigen presentation induced by UV irradiation of Mo.TT was reversed in a dose-dependent manner by the addition of two different preparations containing human interleukin 1 (IL 1). The first preparation consisted of supernatants of Mo. stimulated with Con A for 18 hr and in which Con A activity was blocked by alpha-D-methyl-mannoside (Mo.-Con A-Sup). The second preparation consisted of human IL 1 partially purified from supernatants of human peripheral blood mononuclear cells stimulated with S. albus. This IL 1 copurified with human leukocyte pyrogen (LP) and was termed IL 1/LP. Both IL 1-containing preparations enhanced the response of C57BL/6 mouse thymocytes to phytohemagglutinin. A rabbit antibody to human IL 1/LP inhibited the capacity of T cells to proliferate in response to Mo.TT and inhibited the capacity of Mo.-Con A-Sup to reconstitute the T cell response to UV-irradiated Mo.TT. IL 1/LP was not necessary for T cells to recognize the immunogenic moiety presented by Mo., because monolayers of UV-irradiated Mo.TT were equivalent to monolayers of unirradiated MO.TT in their capacity to adsorb TT-reactive T cells specifically. Furthermore, the addition of rabbit antibody to IL 1/LP did not interfere with the capacity of UV-irradiated Mo.TT to adsorb TT-reactive T cells. The results obtained in this study indicate that IL 1 is involved in optimal antigen-driven proliferation of human T lymphocytes.

Importance of inverse correlation between ALDH3A1 and PPARγ in tumor cells and tissue regeneration.

PubMed

Oraldi, M; Saracino, S; Maggiora, M; Chiaravalloti, A; Buemi, C; Martinasso, G; Paiuzzi, E; Thompson, D; Vasiliou, V; Canuto, R A

2011-05-30

Aldehyde dehydrogenase (ALDH) enzymes are involved in maintaining cellular homeostasis by metabolizing both endogenous and exogenous reactive aldehydes. They modulate several cell functions including proliferation, differentiation, survival as well as cellular response to oxidative stress. We previously reported that ALDH3A1 expression is inversely correlated with the activation of PPARs (Peroxisome Proliferators-Activated Receptors), a category of orphan nuclear hormone receptors, in both rat and human cells. PPARγ is involved in cell proliferation. In this study, we have used PPARγ transfection and inhibition to examine the relationship between ALDH3A1 and PPARγ and their role as regulators of cell proliferation. Induction of PPARγ in A549 and NCTC 2544 cells by transfection caused a decrease in ALDH3A1 and inhibition of cell proliferation, a result we obtained previously using ligands that induce PPARγ. A reduction of PPARγ expression using siRNA increased ALDH3A1 expression and cell proliferation. In cells induced to proliferate in a model of tissue regeneration, ALDH3A1 expression increased during the period of proliferation, whereas PPARγ expression decreased. In conclusion, through modulation of PPARγ or ALDH3A1, it may be possible to reduce cell proliferation in tumor cells or stimulate cell proliferation in normal cells during tissue regeneration. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Cell proliferation within small intestinal crypts is the principal driving force for cell migration on villi

PubMed Central

Parker, Aimee; Maclaren, Oliver J.; Fletcher, Alexander G.; Muraro, Daniele; Kreuzaler, Peter A.; Byrne, Helen M.; Maini, Philip K.; Watson, Alastair J. M.; Pin, Carmen

2017-01-01

The functional integrity of the intestinal epithelial barrier relies on tight coordination of cell proliferation and migration, with failure to regulate these processes resulting in disease. It is not known whether cell proliferation is sufficient to drive epithelial cell migration during homoeostatic turnover of the epithelium. Nor is it known precisely how villus cell migration is affected when proliferation is perturbed. Some reports suggest that proliferation and migration may not be related while other studies support a direct relationship. We used established cell-tracking methods based on thymine analog cell labeling and developed tailored mathematical models to quantify cell proliferation and migration under normal conditions and when proliferation is reduced and when it is temporarily halted. We found that epithelial cell migration velocities along the villi are coupled to cell proliferation rates within the crypts in all conditions. Furthermore, halting and resuming proliferation results in the synchronized response of cell migration on the villi. We conclude that cell proliferation within the crypt is the primary force that drives cell migration along the villus. This methodology can be applied to interrogate intestinal epithelial dynamics and characterize situations in which processes involved in cell turnover become uncoupled, including pharmacological treatments and disease models.—Parker, A., Maclaren, O. J., Fletcher, A. G., Muraro, D., Kreuzaler, P. A., Byrne, H. M., Maini, P. K., Watson, A. J. M., Pin, C. Cell proliferation within small intestinal crypts is the principal driving force for cell migration on villi. PMID:27811059

FAK Regulates Intestinal Epithelial Cell Survival and Proliferation during Mucosal Wound Healing

PubMed Central

Tilghman, Robert W.; Casanova, James E.; Bouton, Amy H.

2011-01-01

Background Following damage to the intestinal epithelium, restoration of epithelial barrier integrity is triggered by a robust proliferative response. In other tissues, focal adhesion kinase (FAK) regulates many of the cellular processes that are critical for epithelial homeostasis and restitution, including cell migration, proliferation and survival. However, few studies to date have determined how FAK contributes to mucosal wound healing in vivo. Methodology and Principal Findings To examine the role of FAK in intestinal epithelial homeostasis and during injury, we generated intestinal epithelium (IE)-specific conditional FAK knockout mice. Colitis was induced with dextran-sulfate-sodium (DSS) and intestinal tissues were analyzed by immunohistochemistry and immunoblotting. While intestinal development occurred normally in mice lacking FAK, FAK-deficient animals were profoundly susceptible to colitis. The loss of epithelial FAK resulted in elevated p53 expression and an increased sensitivity to apoptosis, coincident with a failure to upregulate epithelial cell proliferation. FAK has been reported to function as a mechanosensor, inducing cyclin D1 expression and promoting cell cycle progression under conditions in which tissue/matrix stiffness is increased. Collagen deposition, a hallmark of inflammatory injury resulting in increased tissue rigidity, was observed in control and FAK knockout mice during colitis. Despite this fibrotic response, the colonic epithelium in FAK-deficient mice exhibited significantly reduced cyclin D1 expression, suggesting that proliferation is uncoupled from fibrosis in the absence of FAK. In support of this hypothesis, proliferation of Caco-2 cells increased proportionally with matrix stiffness in vitro only under conditions of normal FAK expression; FAK depleted cells exhibited reduced proliferation concomitant with attenuated cyclin D1 expression. Conclusions In the colon, FAK functions as a regulator of epithelial cell survival and proliferation under conditions of mucosal injury and a mechanosensor of tissue compliance, inducing repair-driven proliferation in the colonic epithelium through upregulation of cyclin D1. PMID:21887232

An epibulbar chocolate cyst: a rare complication of silicone-based scleral buckle

PubMed Central

Venkatesh, Pradeep; Gogia, Varun; Gupta, Shikha; Nayak, Bhagabat

2015-01-01

A patient with a history of vitreoretinal surgery presented with nasal dystopia, diplopia and epibulbar bluish black mass simulating a chocolate cyst in the right eye. After a non-conclusive ocular examination, he underwent CT of the orbit along with volume rendition and three-dimensional reconstruction, which demonstrated intact globe with laterally displaced band-buckle assembly along with peri-scleral buckle element (SBE) soft tissue proliferation. Imaging-assisted exploration of the lesion was performed and retained scleral buckle element (SBE) was removed in toto; thus relieving the patient long-standing dystopia. PMID:26240109

An epibulbar chocolate cyst: a rare complication of silicone-based scleral buckle.

PubMed

Venkatesh, Pradeep; Gogia, Varun; Gupta, Shikha; Nayak, Bhagabat

2015-08-03

A patient with a history of vitreoretinal surgery presented with nasal dystopia, diplopia and epibulbar bluish black mass simulating a chocolate cyst in the right eye. After a non-conclusive ocular examination, he underwent CT of the orbit along with volume rendition and three-dimensional reconstruction, which demonstrated intact globe with laterally displaced band-buckle assembly along with peri-scleral buckle element (SBE) soft tissue proliferation. Imaging-assisted exploration of the lesion was performed and retained scleral buckle element (SBE) was removed in toto; thus relieving the patient long-standing dystopia. 2015 BMJ Publishing Group Ltd.

Fc receptors for mouse IgG1 on human monocytes: polymorphism and role in antibody-induced T cell proliferation.

PubMed

Tax, W J; Hermes, F F; Willems, R W; Capel, P J; Koene, R A

1984-09-01

In previous studies, it was shown that there is polymorphism in the mitogenic effect of mouse IgG1 monoclonal antibodies against the T3 antigen of human T cells. This polymorphism implies that IgG1 anti-T3 antibodies are not mitogenic for T cells from 30% of healthy individuals. The present results demonstrate that this polymorphism is caused by polymorphism of an Fc receptor for mouse IgG1, present on human monocytes. The Fc receptor for murine IgG1 could be detected by a newly developed rosetting assay on monocytes from all individuals responsive to the mitogenic effect of IgG1 anti-T3 antibodies. This Fc receptor was not detectable on monocytes from those individuals exhibiting no mitogenic responses to IgG1 anti-T3 monoclonal antibodies. Cross-linking of T3 antigens appears to be essential for antibody-induced mitosis of T cells, because mononuclear cells that did not proliferate in response to WT 31 (an IgG1 antibody against T3 antigen) showed a proliferative response to Sepharose beads coated with WT 31. The Fc receptor--if functionally present--may be involved in the cross-linking of T3 antigens through anti-T3 antibodies. Further evidence for the involvement of this Fc receptor in antibody-induced T cell proliferation was provided by inhibition studies. Immune complexes containing IgG1 antibodies were able to inhibit the proliferative response to IgG1 anti-T3 antibodies. This inhibition by immune complexes appears to be mediated through the monocyte Fc receptor for mouse IgG1. These findings are important for the interpretation of previously described inhibitory effects of anti-T cell monoclonal antibodies on T cell proliferation, and show that such inhibitory effects may be monocyte-mediated (via immune complexes) rather than caused by a direct involvement of the respective T cell antigens in T cell mitosis. The Fc receptor for mouse IgG1 plays a role in antibody-induced T cell proliferation. Its polymorphism may have important implications for the therapeutic use of IgG1 monoclonal antibodies.

Concurrent Fowlpox and Candidiasis Diseases in Backyard Chickens with Unusual Pox Lesions in the Bursa of Fabricius.

PubMed

Ogasawara, Fusae; Yamamoto, Yu; Sato, Yasuo; Fukunari, Kazuhiro; Murata, Ken-Ichi; Yaegashi, Gakuji; Goto, Makiko; Murakami, Ryukoh

2016-09-01

Concurrent fowlpox and candidiasis diseases occurred in a backyard chicken flock. Four deceased chickens (one Nagoya breed and three white silkie chickens) were examined for diagnosis. At necropsy, white curd-like plaques were observed in the crop. Fungal elements that stained positive for Candida albicans with immunohistochemistry were distributed throughout the tongue, choanal mucosa, esophagus, and crop. Typical fowlpox lesions, composed of proliferating epithelial cells with ballooning degeneration and viral intracytoplasmic inclusions, were observed in the conjunctiva, nasal mucosa, and skin around the cloaca. Interestingly, hyperplastic interfollicular epithelium with rare virus inclusions was observed in the bursa of Fabricius (BF). Some bursal follicles were replaced by proliferating epithelial cells. These proliferating cells immunohistochemically stained positive for cytokeratin. PCR and subsequent genetic sequencing detected the C. albicans gene in the crop, and fowlpox virus genes in the BF. These results indicate that this outbreak was a rare presentation of fowlpox in spontaneously infected chickens, with unusual pox lesions in the BF.

Cytoplasmic proliferating cell nuclear antigen connects glycolysis and cell survival in acute myeloid leukemia.

PubMed

Ohayon, Delphine; De Chiara, Alessia; Chapuis, Nicolas; Candalh, Céline; Mocek, Julie; Ribeil, Jean-Antoine; Haddaoui, Lamya; Ifrah, Norbert; Hermine, Olivier; Bouillaud, Frédéric; Frachet, Philippe; Bouscary, Didier; Witko-Sarsat, Véronique

2016-10-19

Cytosolic proliferating cell nuclear antigen (PCNA), a scaffolding protein involved in DNA replication, has been described as a key element in survival of mature neutrophil granulocytes, which are non-proliferating cells. Herein, we demonstrated an active export of PCNA involved in cell survival and chemotherapy resistance. Notably, daunorubicin-resistant HL-60 cells (HL-60R) have a prominent cytosolic PCNA localization due to increased nuclear export compared to daunorubicin-sensitive HL-60 cells (HL-60S). By interacting with nicotinamide phosphoribosyltransferase (NAMPT), a protein involved in NAD biosynthesis, PCNA coordinates glycolysis and survival, especially in HL-60R cells. These cells showed a dramatic increase in intracellular NAD+ concentration as well as glycolysis including increased expression and activity of hexokinase 1 and increased lactate production. Furthermore, this functional activity of cytoplasmic PCNA was also demonstrated in patients with acute myeloid leukemia (AML). Our data uncover a novel pathway of nuclear export of PCNA that drives cell survival by increasing metabolism flux.

Posttranscriptional Control of T Cell Effector Function by Aerobic Glycolysis

PubMed Central

Chang, Chih-Hao; Curtis, Jonathan D.; Maggi, Leonard B.; Faubert, Brandon; Villarino, Alejandro V.; O’Sullivan, David; Huang, Stanley Ching-Cheng; van der Windt, Gerritje J.W.; Blagih, Julianna; Qiu, Jing; Weber, Jason D.; Pearce, Edward J.; Jones, Russell G.; Pearce, Erika L.

2013-01-01

SUMMARY A “switch” from oxidative phosphorylation (OXPHOS) to aerobic glycolysis is a hallmark of T cell activation and is thought to be required to meet the metabolic demands of proliferation. However, why proliferating cells adopt this less efficient metabolism, especially in an oxygen-replete environment, remains incompletely understood. We show here that aerobic glycolysis is specifically required for effector function in T cells but that this pathway is not necessary for proliferation or survival. When activated T cells are provided with costimulation and growth factors but are blocked from engaging glycolysis, their ability to produce IFN-γ is markedly compromised. This defect is translational and is regulated by the binding of the glycolysis enzyme GAPDH to AU-rich elements within the 3′ UTR of IFN-γ mRNA. GAPDH, by engaging/disengaging glycolysis and through fluctuations in its expression, controls effector cytokine production. Thus, aerobic glycolysis is a metabolically regulated signaling mechanism needed to control cellular function. PMID:23746840

Cytoplasmic proliferating cell nuclear antigen connects glycolysis and cell survival in acute myeloid leukemia

PubMed Central

Ohayon, Delphine; De Chiara, Alessia; Chapuis, Nicolas; Candalh, Céline; Mocek, Julie; Ribeil, Jean-Antoine; Haddaoui, Lamya; Ifrah, Norbert; Hermine, Olivier; Bouillaud, Frédéric; Frachet, Philippe; Bouscary, Didier; Witko-Sarsat, Véronique

2016-01-01

Cytosolic proliferating cell nuclear antigen (PCNA), a scaffolding protein involved in DNA replication, has been described as a key element in survival of mature neutrophil granulocytes, which are non-proliferating cells. Herein, we demonstrated an active export of PCNA involved in cell survival and chemotherapy resistance. Notably, daunorubicin-resistant HL-60 cells (HL-60R) have a prominent cytosolic PCNA localization due to increased nuclear export compared to daunorubicin-sensitive HL-60 cells (HL-60S). By interacting with nicotinamide phosphoribosyltransferase (NAMPT), a protein involved in NAD biosynthesis, PCNA coordinates glycolysis and survival, especially in HL-60R cells. These cells showed a dramatic increase in intracellular NAD+ concentration as well as glycolysis including increased expression and activity of hexokinase 1 and increased lactate production. Furthermore, this functional activity of cytoplasmic PCNA was also demonstrated in patients with acute myeloid leukemia (AML). Our data uncover a novel pathway of nuclear export of PCNA that drives cell survival by increasing metabolism flux. PMID:27759041

Attenuation of HIV-associated human B cell exhaustion by siRNA downregulation of inhibitory receptors

PubMed Central

Kardava, Lela; Moir, Susan; Wang, Wei; Ho, Jason; Buckner, Clarisa M.; Posada, Jacqueline G.; O’Shea, Marie A.; Roby, Gregg; Chen, Jenny; Sohn, Hae Won; Chun, Tae-Wook; Pierce, Susan K.; Fauci, Anthony S.

2011-01-01

Chronic immune activation in HIV-infected individuals leads to accumulation of exhausted tissue-like memory B cells. Exhausted lymphocytes display increased expression of multiple inhibitory receptors, which may contribute to the inefficiency of HIV-specific antibody responses. Here, we show that downregulation of B cell inhibitory receptors in primary human B cells led to increased tissue-like memory B cell proliferation and responsiveness against HIV. In human B cells, siRNA knockdown of 9 known and putative B cell inhibitory receptors led to enhanced B cell receptor–mediated (BCR-mediated) proliferation of tissue-like memory but not other B cell subpopulations. The strongest effects were observed with the putative inhibitory receptors Fc receptor–like–4 (FCRL4) and sialic acid–binding Ig-like lectin 6 (Siglec-6). Inhibitory receptor downregulation also led to increased levels of HIV-specific antibody-secreting cells and B cell–associated chemokines and cytokines. The absence of known ligands for FCRL4 and Siglec-6 suggests these receptors may regulate BCR signaling through their own constitutive or tonic signaling. Furthermore, the extent of FCLR4 knockdown effects on BCR-mediated proliferation varied depending on the costimulatory ligand, suggesting that inhibitory receptors may engage specific pathways in inhibiting B cell proliferation. These findings on HIV-associated B cell exhaustion define potential targets for reversing the deleterious effect of inhibitory receptors on immune responses against persistent viral infections. PMID:21633172

Transitional change in rat fetal cell proliferation in response to ghrelin and des-acyl ghrelin during the last stage of pregnancy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Inoue, Yoshiyuki; Nakahara, Keiko; Kangawa, Kenji

Expression of mRNA for the ghrelin receptor, GHS-R1a, was detected in various peripheral and central tissues of fetal rats, including skin, bone, heart, liver, gut, brain and spinal cord, on embryonic day (ED)15 and ED17. However, its expression in skin, bone, heart and liver, but not in gut, brain and spinal cord, became relatively weak on ED19 and disappeared after birth (ND2). Ghrelin and des-acyl ghrelin facilitated the proliferation of cultured fetal (ED17, 19), but not neonatal (ND2), skin cells. On the other hand, with regard to cells from the spinal cord and hypothalamus, the proliferative effect of ghrelin continuedmore » after birth, whereas the effect of des-acyl ghrelin on neurogenesis in these tissues was lost at the ED19 fetal and ND2 neonatal stages. Immunohistochemistry revealed that the cells in the hypothalamus induced to proliferate by ghrelin at the ND2 stage were positive for nestin and glial fibrillary acidic protein. These results suggest that in the period immediately prior to, and after birth, rat fetal cells showing proliferation in response to ghrelin and des-acyl ghrelin are at a transitional stage characterized by alteration of the expression of GHS-R1a and an undefined des-acyl ghrelin receptor, their responsiveness varying among different tissues.« less

TCR revision generates functional CD4+ T cells1

PubMed Central

Hale, J. Scott; Wubeshet, Maramawit; Fink, Pamela J.

2010-01-01

CD4+Vβ5+ peripheral T cells in B6 mice respond to encounter with a peripherally-expressed endogenous superantigen by undergoing either deletion or TCR revision. In this latter process, cells lose surface Vβ5 expression and undergo RAG-dependent rearrangement of endogenous TCRβ genes, driving surface expression of novel TCRs. While post-revision CD4+Vβ5−TCRβ+ T cells accumulate with age in Vβ5 transgenic mice and bear a diverse TCR Vβ repertoire, it is unknown whether they respond to homeostatic and antigenic stimuli, and thus may benefit the host. We now demonstrate that post-revision cells are functional. These cells have a high rate of steady-state homeostatic proliferation in situ and they undergo extensive MHC class II-dependent lymphopenia-induced proliferation. Importantly, post-revision cells do not proliferate in response to the tolerizing superantigen, implicating TCR revision as a mechanism of tolerance induction and demonstrating that TCR-dependent activation of post-revision cells is not driven by the transgene-encoded receptor. Post-revision cells proliferate extensively to commensal bacterial Ags and can generate I-Ab-restricted responses to Ag by producing IFNγ following Listeria monocytogenes challenge. These data show that rescued post-revision T cells are responsive to homeostatic signals and recognize self and foreign peptides in the context of self MHC, and are thus useful to the host. PMID:20971922

TCR revision generates functional CD4+ T cells.

PubMed

Hale, J Scott; Wubeshet, Maramawit; Fink, Pamela J

2010-12-01

CD4(+)Vβ5(+) peripheral T cells in C57BL/6 mice respond to encounter with a peripherally expressed endogenous superantigen by undergoing either deletion or TCR revision. In this latter process, cells lose surface Vβ5 expression and undergo RAG-dependent rearrangement of endogenous TCRβ genes, driving surface expression of novel TCRs. Although postrevision CD4(+)Vβ5(-)TCRβ(+) T cells accumulate with age in Vβ5 transgenic mice and bear a diverse TCR Vβ repertoire, it is unknown whether they respond to homeostatic and antigenic stimuli and thus may benefit the host. We demonstrate in this study that postrevision cells are functional. These cells have a high rate of steady-state homeostatic proliferation in situ, and they undergo extensive MHC class II-dependent lymphopenia-induced proliferation. Importantly, postrevision cells do not proliferate in response to the tolerizing superantigen, implicating TCR revision as a mechanism of tolerance induction and demonstrating that TCR-dependent activation of postrevision cells is not driven by the transgene-encoded receptor. Postrevision cells proliferate extensively to commensal bacterial Ags and can generate I-A(b)-restricted responses to Ag by producing IFN-γ following Listeria monocytogenes challenge. These data show that rescued postrevision T cells are responsive to homeostatic signals and recognize self- and foreign peptides in the context of self-MHC and are thus useful to the host.

Evaluation of the Biological Activity of Opuntia ficus indica as a Tissue- and Estrogen Receptor Subtype-Selective Modulator.

PubMed

An, Byoung Ha; Jeong, Hyesoo; Zhou, Wenmei; Liu, Xiyuan; Kim, Soolin; Jang, Chang Young; Kim, Hyun-Sook; Sohn, Johann; Park, Hye-Jin; Sung, Na-Hye; Hong, Cheol Yi; Chang, Minsun

2016-06-01

Phytoestrogens are selective estrogen receptor modulators (SERMs) with potential for use in hormone replacement therapy (HRT) to relieve peri/postmenopausal symptoms. This study was aimed at elucidating the molecular mechanisms underlying the SERM properties of the extract of Korean-grown Opuntia ficus-indica (KOFI). The KOFI extract induced estrogen response element (ERE)-driven transcription in breast and endometrial cancer cell lines and the expression of endogenous estrogen-responsive genes in breast cancer cells. The flavonoid content of different KOFI preparations affected ERE-luciferase activities, implying that the flavonoid composition likely mediated the estrogenic activities in cells. Oral administration of KOFI decreased the weight gain and levels of both serum glucose and triglyceride in ovariectomized (OVX) rats. Finally, KOFI had an inhibitory effect on the 17β-estradiol-induced proliferation of the endometrial epithelium in OVX rats. Our data demonstrate that KOFI exhibited SERM activity with no uterotrophic side effects. Therefore, KOFI alone or in combination with other botanical supplements, vitamins, or minerals may be an effective and safe alternative active ingredient to HRTs, for the management of postmenopausal symptoms. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

p67SRF is a constitutive nuclear protein implicated in the modulation of genes required throughout the G1 period.

PubMed Central

Gauthier-Rouvière, C; Cavadore, J C; Blanchard, J M; Lamb, N J; Fernandez, A

1991-01-01

Indirect immunofluorescence analysis, using antibodies directed against peptide sequences outside the DNA-binding domain of the 67-kDa serum response factor (p67SRF), revealed a punctuated nuclear staining, constant throughout the cell cycle and in all different cell lines tested. p67SRF was also tightly associated with chromatin through all stages of mitosis. Inhibition of p67SRF activity in vivo, through microinjection of anti-p67SRF antibodies, specifically suppressed DNA synthesis induced after serum addition or ras microinjection, suggesting that these antibodies were effective in preventing expression of serum response element (SRE)-regulated genes. A similar inhibition was also obtained in cells injected with oligonucleotides corresponding to the DNA binding sequence for p67SRF protein, SRE. Moreover, this inhibition of DNA synthesis by anti-p67SRF or SRE injection was still observed in cells injected during late G1, well after c-fos induction. These data imply that genes regulated by p67SRF are continuously involved in the proliferation pathway throughout G1 and that p67SRF forms an integral component of mammalian cell transcriptional control. Images PMID:1782216

The Roles of Extrinsic Factors in a Community of Inquiry Model of E-Learning

ERIC Educational Resources Information Center

Lee, Richard; Faulkner, Margaret

2011-01-01

Despite its proliferation in higher learning institutions, e-learning has been criticised as being nothing more than trivial online conversations, or a mere means of delivering class materials electronically. If e-learning is to address such criticisms and become an effective pedagogical platform, educators need to identify elements critical to…

Curricular Treatment of Body Image, Self-Esteem and Self-Concept in Spain

ERIC Educational Resources Information Center

Rodríguez, Antonio V.; Estévez, Manuel; Palomares, Juan

2015-01-01

Adolescence is a period of human development in which problems with the perception of body image, self-esteem and self-concept proliferate, while the child is studying for Secondary Education. This study analyses the curricular treatment given to body image, self-esteem and self-concept in different legislative elements in the region of Valencia…

Development of the Electronic Portfolio Student Perspective Instrument: An ePortfolio Integration Initiative

ERIC Educational Resources Information Center

Ritzhaupt, Albert Dieter; Singh, Oma; Seyferth, Thelma; Dedrick, Robert F.

2008-01-01

With the proliferation of eportfolios and their organizational uses in higher education, it is important for educators and other relevant stakeholders to understand the student perspective. The way students view and use ePortfolios are revealing elements to aid educators in the successful integration of ePortfolio systems. This research describes…

Simulation on reactor TRIGA Puspati core kinetics fueled with thorium (Th) based fuel element

NASA Astrophysics Data System (ADS)

Mohammed, Abdul Aziz; Pauzi, Anas Muhamad; Rahman, Shaik Mohmmed Haikhal Abdul; Zin, Muhamad Rawi Muhammad; Jamro, Rafhayudi; Idris, Faridah Mohamad

2016-01-01

In confronting global energy requirement and the search for better technologies, there is a real case for widening the range of potential variations in the design of nuclear power plants. Smaller and simpler reactors are attractive, provided they can meet safety and security standards and non-proliferation issues. On fuel cycle aspect, thorium fuel cycles produce much less plutonium and other radioactive transuranic elements than uranium fuel cycles. Although not fissile itself, Th-232 will absorb slow neutrons to produce uranium-233 (233U), which is fissile. By introducing Thorium, the numbers of highly enriched uranium fuel element can be reduced while maintaining the core neutronic performance. This paper describes the core kinetic of a small research reactor core like TRIGA fueled with a Th filled fuel element matrix using a general purpose Monte Carlo N-Particle (MCNP) code.

Simulation on reactor TRIGA Puspati core kinetics fueled with thorium (Th) based fuel element

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mohammed, Abdul Aziz, E-mail: azizM@uniten.edu.my; Rahman, Shaik Mohmmed Haikhal Abdul; Pauzi, Anas Muhamad, E-mail: anas@uniten.edu.my

2016-01-22

In confronting global energy requirement and the search for better technologies, there is a real case for widening the range of potential variations in the design of nuclear power plants. Smaller and simpler reactors are attractive, provided they can meet safety and security standards and non-proliferation issues. On fuel cycle aspect, thorium fuel cycles produce much less plutonium and other radioactive transuranic elements than uranium fuel cycles. Although not fissile itself, Th-232 will absorb slow neutrons to produce uranium-233 ({sup 233}U), which is fissile. By introducing Thorium, the numbers of highly enriched uranium fuel element can be reduced while maintainingmore » the core neutronic performance. This paper describes the core kinetic of a small research reactor core like TRIGA fueled with a Th filled fuel element matrix using a general purpose Monte Carlo N-Particle (MCNP) code.« less

Constant Applied Force Stimulates Osteoblast Proliferation Via Matrix-Integrin-Signaling Pathways

NASA Technical Reports Server (NTRS)

Vercoutere, W.; Parra, M.; Roden, C.; DaCosta, M.; Wing, A.; Damsky, C.; Holton, E.; Searby, N.; Globus, R.; Almeida, E. A. C.

2003-01-01

Reduced weight-bearing caused by immobilization, bed-rest or microgravity leads to atrophy in mechanosensitive tissue such as muscle and bone. We hypothesize that bone tissue requires earth s gravity (1-g) for the maintenance of extracellular matrix, integrin, and kinase-mediated cell growth and survival pathways. We investigate the role of matrix-integrin signaling in bone cells using cell culture centrifugation to provide different levels of hypergravity mechanostimulation. The 10-50-g range we use also mimics physiological intermedullary pressure (1.2 - 5 kPa). 24 hours at 50-g increased primary rat osteoblast proliferation on collagen Type I and fibronectin, but not laminin or uncoated plastic. BrdU incorporation in primary osteoblasts over 24 h showed hypergravity increased the number of cells actively synthesizing DNA from about 60% at 1-g to over 90% at 25-g. Primary rat fibroblasts grown at 50-g (24 h) showed no proliferation increase, suggesting this is a tissue-specific phenomenon. These results suggest that the betal and alpha4 integrins may be involved. To further test this, we used osteocytic-like MLO-Y4 cells that showed increased proliferation at 1-g with stable expression of a betal integrin cytoplasmic tail and transmembrane domain construct. At 50-g, MLO-Y4/betal cells showed greater MAPK activation than MLO-Y4 vector controls, suggesting that betal integrin is involved in transducing mitogenic signals in response to hypergravity. Preliminary results also show that interfering with the alpha4 integrin in primary osteoblasts grown on fibronectin blocked the proliferation response. These results indicate that cells from mechanosensitive bone tissue can respond to gravity-generated forces, and this response involves specific matrix and integrin-dependent signaling pathways.

Cellular immune responses to platelet factor 4 and heparin complexes in patients with heparin-induced thrombocytopenia.

PubMed

Nazy, Ishac; Clare, Rumi; Staibano, Phillip; Warkentin, Theodore E; Larche, Mark; Moore, Jane C; Smith, James W; Whitlock, Richard P; Kelton, John G; Arnold, Donald M

2018-05-03

Heparin-induced thrombocytopenia (HIT) is an adverse reaction to heparin characterized by thrombocytopenia and thrombotic complications. HIT is caused by pathogenic antibodies that bind to complexes of platelet factor 4 and heparin (PF4/heparin) leading to platelet activation and inducing a hypercoagulable state. Previous studies have shown immunity to PF4/heparin occurs early in life even before heparin exposure; however, the immunogenesis of HIT is not well characterized. The aim of this study was to investigate cellular proliferation in response to PF4/heparin complexes in patients with HIT. Peripheral blood mononuclear cells (PBMCs) from healthy controls (n = 30), postoperative cardiac surgery patients who underwent cardiopulmonary bypass (CPB, n = 17), and patients with confirmed HIT (n = 41) were cultured with PF4 and PF4/heparin. Cellular proliferation was assessed by 3 H-thymidine uptake and 5-ethynyl-2'-deoxyuridine (EdU) detection. PBMCs proliferated in the presence of PF4 and was enhanced by the addition of heparin in all study groups. CPB and HIT patients exhibited significantly higher proliferative responses compared to healthy controls. PBMC proliferation was antigen-specific, depended on the presence of platelets, and only CD14 + cells were identified as proliferating cells. Culture supernatants were tested for the levels of regulatory cytokines and both CPB and HIT patients produced significantly lower levels of IL-10 and TGF-β1 compared to healthy controls. These findings further demonstrate that cellular immune sensitization to PF4/heparin occurs before heparin exposure and suggests that immune dysregulation can contribute to the immunogenesis of HIT. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Acute exercise boosts cell proliferation and the heat shock response in lymphocytes: correlation with cytokine production and extracellular-to-intracellular HSP70 ratio.

PubMed

Heck, Thiago Gomes; Scomazzon, Sofia Pizzato; Nunes, Patrícia Renck; Schöler, Cinthia Maria; da Silva, Gustavo Stumpf; Bittencourt, Aline; Faccioni-Heuser, Maria Cristina; Krause, Mauricio; Bazotte, Roberto Barbosa; Curi, Rui; Homem de Bittencourt, Paulo Ivo

2017-03-01

Exercise stimulates immune responses, but the appropriate "doses" for such achievements are unsettled. Conversely, in metabolic tissues, exercise improves the heat shock (HS) response, a universal cytoprotective response to proteostasis challenges that are centred on the expression of the 70-kDa family of intracellular heat shock proteins (iHSP70), which are anti-inflammatory. Concurrently, exercise triggers the export of HSP70 towards the extracellular milieu (eHSP70), where they work as pro-inflammatory cytokines. As the HS response is severely compromised in chronic degenerative diseases of inflammatory nature, we wondered whether acute exercise bouts of different intensities could alter the HS response of lymphocytes from secondary lymphoid organs and whether this would be related to immunoinflammatory responses. Adult male Wistar rats swam for 20 min at low, moderate, high or strenuous intensities as per an overload in tail base. Controls remained at rest under the same conditions. Afterwards, mesenteric lymph node lymphocytes were assessed for the potency of the HS response (42 °C for 2 h), NF-κB binding activity, mitogen-stimulated proliferation and cytokine production. Exercise stimulated cell proliferation in an "inverted-U" fashion peaking at moderate load, which was paralleled by suppression of NF-κB activation and nuclear location, and followed by enhanced HS response in relation to non-exercised animals. Comparative levels of eHSP70 to iHSP70 (H-index) matched IL-2/IL-10 ratios. We conclude that exercise, in a workload-dependent way, stimulates immunoinflammatory performance of lymphocytes of tissues far from the circulation and this is associated with H-index of stress response, which is useful to assess training status and immunosurveillance balance.

Regulation of Axolotl (Ambystoma mexicanum) Limb Blastema Cell Proliferation by Nerves and BMP2 in Organotypic Slice Culture.

PubMed

Lehrberg, Jeffrey; Gardiner, David M

2015-01-01

We have modified and optimized the technique of organotypic slice culture in order to study the mechanisms regulating growth and pattern formation in regenerating axolotl limb blastemas. Blastema cells maintain many of the behaviors that are characteristic of blastemas in vivo when cultured as slices in vitro, including rates of proliferation that are comparable to what has been reported in vivo. Because the blastema slices can be cultured in basal medium without fetal bovine serum, it was possible to test the response of blastema cells to signaling molecules present in serum, as well as those produced by nerves. We also were able to investigate the response of blastema cells to experimentally regulated changes in BMP signaling. Blastema cells responded to all of these signals by increasing the rate of proliferation and the level of expression of the blastema marker gene, Prrx-1. The organotypic slice culture model provides the opportunity to identify and characterize the spatial and temporal co-regulation of pathways in order to induce and enhance a regenerative response.

Regulation of Axolotl (Ambystoma mexicanum) Limb Blastema Cell Proliferation by Nerves and BMP2 in Organotypic Slice Culture

PubMed Central

Lehrberg, Jeffrey; Gardiner, David M.

2015-01-01

We have modified and optimized the technique of organotypic slice culture in order to study the mechanisms regulating growth and pattern formation in regenerating axolotl limb blastemas. Blastema cells maintain many of the behaviors that are characteristic of blastemas in vivo when cultured as slices in vitro, including rates of proliferation that are comparable to what has been reported in vivo. Because the blastema slices can be cultured in basal medium without fetal bovine serum, it was possible to test the response of blastema cells to signaling molecules present in serum, as well as those produced by nerves. We also were able to investigate the response of blastema cells to experimentally regulated changes in BMP signaling. Blastema cells responded to all of these signals by increasing the rate of proliferation and the level of expression of the blastema marker gene, Prrx-1. The organotypic slice culture model provides the opportunity to identify and characterize the spatial and temporal co-regulation of pathways in order to induce and enhance a regenerative response. PMID:25923915

SerpinB1 Promotes Pancreatic β Cell Proliferation

DOE Office of Scientific and Technical Information (OSTI.GOV)

El Ouaamari, Abdelfattah; Dirice, Ercument; Gedeon, Nicholas

2016-01-01

Compensatory β-cell growth in response to insulin resistance is a common feature in diabetes. We recently reported that liver-derived factors participate in this compensatory response in the liver insulin receptor knockout (LIRKO) mouse, a model of significant islet hyperplasia. Here we show that serpinB1 is a liver-derived secretory protein that controls β-cell proliferation. SerpinB1 is abundant in the hepatocyte secretome and sera derived from LIRKO mice. SerpinB1 and small molecule compounds that partially mimic serpinB1 activity enhanced proliferation of zebrafish, mouse and human β-cells. We report that serpinB1-induced β-cell replication requires protease inhibition activity and mice lacking serpinB1 exhibit attenuatedmore » β-cell replication in response to insulin resistance. Finally, SerpinB1-treatment of islets modulated signaling proteins in growth and survival pathways such as MAPK, PKA and GSK3. Together, these data implicate SerpinB1 as a protein that can potentially be harnessed to enhance functional β-cell mass in patients with diabetes.« less

The mechanism of retrovirus suppression of human T cell proliferation in vitro.

PubMed

Copelan, E A; Rinehart, J J; Lewis, M; Mathes, L; Olsen, R; Sagone, A

1983-10-01

Immunosuppression is commonly associated with retrovirus-induced animal tumors. Studies in the murine and feline retrovirus systems suggest that the 15,000-dalton envelope protein (p15E) of the virion may contribute to immunosuppression by interfering with normal lymphocyte function. We examined the effect of inactivated feline leukemia virus (UV-FeLV) and p15E derived from this virus on concanavalin A (Con A) driven human T cell proliferation. Virus and p15E markedly suppressed mononuclear cell proliferative response to Con A. Suppression was not due to inhibition of monocyte accessory cell function, or interleukin 1 (IL 1) secretion. In fact, the presence of monocytes partially protected T cells from UV-FeLV suppression. UV-FeLV, however, suppressed T cell secretion of and response to interleukin 2 (IL 2). We conclude that UV-FeLV and derived p15E inhibit T cell proliferation by direct inhibition of T cell function. These findings, extended to the in vivo situations, suggest that retrovirus-associated suppression of the immune response involves the induction of T cell but not monocyte dysfunction.

Higher O-GlcNAc Levels Are Associated with Defects in Progenitor Proliferation and Premature Neuronal Differentiation during in-Vitro Human Embryonic Cortical Neurogenesis

PubMed Central

Parween, Shama; Varghese, Divya S.; Ardah, Mustafa T.; Prabakaran, Ashok D.; Mensah-Brown, Eric; Emerald, Bright Starling; Ansari, Suraiya A.

2017-01-01

The nutrient responsive O-GlcNAcylation is a dynamic post-translational protein modification found on several nucleocytoplasmic proteins. Previous studies have suggested that hyperglycemia induces the levels of total O-GlcNAcylation inside the cells. Hyperglycemia mediated increase in protein O-GlcNAcylation has been shown to be responsible for various pathologies including insulin resistance and Alzheimer's disease. Since maternal hyperglycemia during pregnancy is associated with adverse neurodevelopmental outcomes in the offspring, it is intriguing to identify the effect of increased protein O-GlcNAcylation on embryonic neurogenesis. Herein using human embryonic stem cells (hESCs) as model, we show that increased levels of total O-GlcNAc is associated with decreased neural progenitor proliferation and premature differentiation of cortical neurons, reduced AKT phosphorylation, increased apoptosis and defects in the expression of various regulators of embryonic corticogenesis. As defects in proliferation and differentiation during neurodevelopment are common features of various neurodevelopmental disorders, increased O-GlcNAcylation could be one mechanism responsible for defective neurodevelopmental outcomes in metabolically compromised pregnancies such as diabetes. PMID:29311838

Toll-like receptor signaling in cell proliferation and survival

PubMed Central

Li, Xinyan; Jiang, Song; Tapping, Richard I.

2009-01-01

Toll-like receptors (TLRs) are important sensors of foreign microbial components as well as products of damaged or inflamed self tissues. Upon sensing these molecules, TLRs initiate a series of downstream signaling events that drive cellular responses including the production of cytokines, chemokines and other inflammatory mediators. This outcome results from the intracellular assembly of protein complexes that drive phosphorylation and other signaling cascades ultimately leading to chromatin remodeling and transcription factor activation. In addition to driving inflammatory responses, TLRs also regulate cell proliferation and survival which serves to expand useful immune cells and integrate inflammatory responses and tissue repair processes. In this context, central TLR signaling molecules, such as the mitogen-activated protein kinases (MAPK) and phosphoinositide 3-kinase (PI3K), play key roles. In addition, four major groups of transcription factors which are targets of TLR activation also control cell fate. This review focuses on the role of TLR signaling as it relates to cell proliferation and survival. This topic not only has important implications for understanding host defense and tissue repair, but also cancer which is often associated with conditions of chronic inflammation. PMID:19775907

Proliferation of the human urothelium is induced by atypical β1 -adrenoceptors.

PubMed

Winder, M; Wasén, C; Aronsson, P; Giglio, D

2015-09-01

We wanted to assess whether β-adrenoceptors mediate proliferation in the normal and malignant urothelial cell lines UROtsa and T24, respectively. Urothelial cells were cultured for 24 h in the presence of the β-adrenoceptor agonists isoprenaline (β1/2/3 ), dobutamine (β1 ), salbutamol (β2 ), BRL 37344 (β3 ), CGP 12177 (a partial β-agonist) or β-adrenoceptor antagonists (metoprolol; β1 , propranolol; β1/2 ). Phosphorylation of kinases was screened with a Human Phospho-Kinase Array Kit (R&D systems). Intracellular pathways activated by proliferation of urothelial cells were characterized by incubating cells with the MEK1/2 inhibitor PD 98,059, the p38 kinase inhibitor losmapimod or with the Akt 1/2 kinase inhibitor. Proliferation was assessed with the MTT proliferation assay (ATCC). Western blot and immunocytochemistry were used for detection of the β1 -adrenoceptor. Isoprenaline and dobutamine induced proliferation, while salbutamol and BRL 37344 did not. Dobutamine-induced proliferation was not affected by metoprolol or propranolol but was instead antagonized by CGP 12177 in T24 but not in UROtsa. In response to stimulation with dobutamine, Akt1/2/3 was phosphorylated in UROtsa, while ERK1/2 and p38 were phosphorylated in T24. MEK1/2 inhibition blocked basal and dobutamine-induced proliferation in T24 but only basal proliferation in UROtsa. Losmapimod slightly inhibited basal proliferation in T24 but not dobutamine-induced proliferation. Akt 1/2 inhibitor blocked basal and dobutamine-induced proliferation in UROtsa. Immunocytochemistry and Western blot revealed expression of β1 -adrenoceptors in both urothelial cell lines. The present data show that the urothelium expresses atypical β1-adrenoceptors that activate intracellular kinases inducing urothelial proliferation. © 2016 John Wiley & Sons Ltd.

Developmental regulation of CYCA2s contributes to tissue-specific proliferation in Arabidopsis

PubMed Central

Vanneste, Steffen; Coppens, Frederik; Lee, EunKyoung; Donner, Tyler J; Xie, Zidian; Van Isterdael, Gert; Dhondt, Stijn; De Winter, Freya; De Rybel, Bert; Vuylsteke, Marnik; De Veylder, Lieven; Friml, Jiří; Inzé, Dirk; Grotewold, Erich; Scarpella, Enrico; Sack, Fred; Beemster, Gerrit T S; Beeckman, Tom

2011-01-01

In multicellular organisms, morphogenesis relies on a strict coordination in time and space of cell proliferation and differentiation. In contrast to animals, plant development displays continuous organ formation and adaptive growth responses during their lifespan relying on a tight coordination of cell proliferation. How developmental signals interact with the plant cell-cycle machinery is largely unknown. Here, we characterize plant A2-type cyclins, a small gene family of mitotic cyclins, and show how they contribute to the fine-tuning of local proliferation during plant development. Moreover, the timely repression of CYCA2;3 expression in newly formed guard cells is shown to require the stomatal transcription factors FOUR LIPS/MYB124 and MYB88, providing a direct link between developmental programming and cell-cycle exit in plants. Thus, transcriptional downregulation of CYCA2s represents a critical mechanism to coordinate proliferation during plant development. PMID:21772250

Behavioral Fever Drives Epigenetic Modulation of the Immune Response in Fish.

PubMed

Boltana, Sebastian; Aguilar, Andrea; Sanhueza, Nataly; Donoso, Andrea; Mercado, Luis; Imarai, Monica; Mackenzie, Simon

2018-01-01

Ectotherms choose the best thermal conditions to mount a successful immune response, a phenomenon known as behavioral fever. The cumulative evidence suggests that behavioral fever impacts positively upon lymphocyte proliferation, inflammatory cytokine expression, and other immune functions. In this study, we have explored how thermal choice during infection impacts upon underpinning molecular processes and how temperature increase is coupled to the immune response. Our results show that behavioral fever results in a widespread, plastic imprint on gene regulation, and lymphocyte proliferation. We further explored the possible contribution of histone modification and identified global associations between temperature and histone changes that suggest epigenetic remodeling as a result of behavioral fever. Together, these results highlight the critical importance of thermal choice in mobile ectotherms, particularly in response to an infection, and demonstrate the key role of epigenetic modification to orchestrate the thermocoupling of the immune response during behavioral fever.

Inhibition of Vascular Smooth Muscle Cell Proliferation by Gentiana lutea Root Extracts

PubMed Central

Kesavan, Rushendhiran; Potunuru, Uma Rani; Nastasijević, Branislav; T, Avaneesh; Joksić, Gordana; Dixit, Madhulika

2013-01-01

Gentiana lutea belonging to the Gentianaceae family of flowering plants are routinely used in traditional Serbian medicine for their beneficial gastro-intestinal and anti-inflammatory properties. The aim of the study was to determine whether aqueous root extracts of Gentiana lutea consisting of gentiopicroside, gentisin, bellidifolin-8-O-glucoside, demethylbellidifolin-8-O-glucoside, isovitexin, swertiamarin and amarogentin prevents proliferation of aortic smooth muscle cells in response to PDGF-BB. Cell proliferation and cell cycle analysis were performed based on alamar blue assay and propidium iodide labeling respectively. In primary cultures of rat aortic smooth muscle cells (RASMCs), PDGF-BB (20 ng/ml) induced a two-fold increase in cell proliferation which was significantly blocked by the root extract (1 mg/ml). The root extract also prevented the S-phase entry of synchronized cells in response to PDGF. Furthermore, PDGF-BB induced ERK1/2 activation and consequent increase in cellular nitric oxide (NO) levels were also blocked by the extract. These effects of extract were due to blockade of PDGF-BB induced expression of iNOS, cyclin D1 and proliferating cell nuclear antigen (PCNA). Docking analysis of the extract components on MEK1, the upstream ERK1/2 activating kinase using AutoDock4, indicated a likely binding of isovitexin to the inhibitor binding site of MEK1. Experiments performed with purified isovitexin demonstrated that it successfully blocks PDGF-induced ERK1/2 activation and proliferation of RASMCs in cell culture. Thus, Gentiana lutea can provide novel candidates for prevention and treatment of atherosclerosis. PMID:23637826

Inhibition of vascular smooth muscle cell proliferation by Gentiana lutea root extracts.

PubMed

Kesavan, Rushendhiran; Potunuru, Uma Rani; Nastasijević, Branislav; T, Avaneesh; Joksić, Gordana; Dixit, Madhulika

2013-01-01

Gentiana lutea belonging to the Gentianaceae family of flowering plants are routinely used in traditional Serbian medicine for their beneficial gastro-intestinal and anti-inflammatory properties. The aim of the study was to determine whether aqueous root extracts of Gentiana lutea consisting of gentiopicroside, gentisin, bellidifolin-8-O-glucoside, demethylbellidifolin-8-O-glucoside, isovitexin, swertiamarin and amarogentin prevents proliferation of aortic smooth muscle cells in response to PDGF-BB. Cell proliferation and cell cycle analysis were performed based on alamar blue assay and propidium iodide labeling respectively. In primary cultures of rat aortic smooth muscle cells (RASMCs), PDGF-BB (20 ng/ml) induced a two-fold increase in cell proliferation which was significantly blocked by the root extract (1 mg/ml). The root extract also prevented the S-phase entry of synchronized cells in response to PDGF. Furthermore, PDGF-BB induced ERK1/2 activation and consequent increase in cellular nitric oxide (NO) levels were also blocked by the extract. These effects of extract were due to blockade of PDGF-BB induced expression of iNOS, cyclin D1 and proliferating cell nuclear antigen (PCNA). Docking analysis of the extract components on MEK1, the upstream ERK1/2 activating kinase using AutoDock4, indicated a likely binding of isovitexin to the inhibitor binding site of MEK1. Experiments performed with purified isovitexin demonstrated that it successfully blocks PDGF-induced ERK1/2 activation and proliferation of RASMCs in cell culture. Thus, Gentiana lutea can provide novel candidates for prevention and treatment of atherosclerosis.

Wnt signaling induces proliferation of sensory precursors in the postnatal mouse cochlea.

PubMed

Chai, Renjie; Kuo, Bryan; Wang, Tian; Liaw, Eric J; Xia, Anping; Jan, Taha A; Liu, Zhiyong; Taketo, Makoto M; Oghalai, John S; Nusse, Roeland; Zuo, Jian; Cheng, Alan G

2012-05-22

Inner ear hair cells are specialized sensory cells essential for auditory function. Previous studies have shown that the sensory epithelium is postmitotic, but it harbors cells that can behave as progenitor cells in vitro, including the ability to form new hair cells. Lgr5, a Wnt target gene, marks distinct supporting cell types in the neonatal cochlea. Here, we tested the hypothesis that Lgr5(+) cells are Wnt-responsive sensory precursor cells. In contrast to their quiescent in vivo behavior, Lgr5(+) cells isolated by flow cytometry from neonatal Lgr5(EGFP-CreERT2/+) mice proliferated and formed clonal colonies. After 10 d in culture, new sensory cells formed and displayed specific hair cell markers (myo7a, calretinin, parvalbumin, myo6) and stereocilia-like structures expressing F-actin and espin. In comparison with other supporting cells, Lgr5(+) cells were enriched precursors to myo7a(+) cells, most of which formed without mitotic division. Treatment with Wnt agonists increased proliferation and colony-formation capacity. Conversely, small-molecule inhibitors of Wnt signaling suppressed proliferation without compromising the myo7a(+) cells formed by direct differentiation. In vivo lineage tracing supported the idea that Lgr5(+) cells give rise to myo7a(+) hair cells in the neonatal Lgr5(EGFP-CreERT2/+) cochlea. In addition, overexpression of β-catenin initiated proliferation and led to transient expansion of Lgr5(+) cells within the cochlear sensory epithelium. These results suggest that Lgr5 marks sensory precursors and that Wnt signaling can promote their proliferation and provide mechanistic insights into Wnt-responsive progenitor cells during sensory organ development.

Effects of environmental stressors on lymphocyte proliferation in Florida manatees, Trichechus manatus latirostris.

PubMed

Walsh, Cathy J; Luer, Carl A; Noyes, David R

2005-02-10

The health of many Florida manatees (Trichechus manatus latirostris) is adversely affected each year by exposure to cold weather or harmful algal blooms (red tide; Karenia brevis). Exposures can be sublethal, resulting in stressed animals that are rescued and taken to authorized facilities for rehabilitation, or lethal if exposures are prolonged or unusually severe. To investigate whether sublethal environmental exposures can impair immune function in manatees, rendering animals vulnerable to disease or death, mitogen-induced proliferation was assessed in lymphocytes from manatees exposed to cold temperatures (N=20) or red tide (N=19) in the wild, and compared to lymphocyte responses from healthy free-ranging manatees (N=32). All animals sampled for this study were adults. Lymphocytes were stimulated in vitro with either concanavalin A (ConA) or phytohemagglutinin (PHA) and proliferation was assessed after 96 h using incorporation of the thymidine analog, bromodeoxyuridine (BrdU), into newly synthesized DNA. Proliferation of lymphocytes from manatees rescued from exposure to red tide or cold-stress was approximately one-third that of lymphocytes from healthy free-ranging manatees. To examine the direct effects of red tide toxins on lymphocyte function, mitogen-induced proliferation was assessed following co-culture of lymphocytes with K. brevis toxin extracts. Stimulation indices decreased with increasing toxin concentration, with a significant decrease in proliferation occurring in the presence of 400 ng red tide toxins/ml. When lymphocytes from cold-stressed manatees were co-cultured with red tide toxin extracts, proliferative responses were reduced even further, suggesting multiple stressors may have synergistic effects on immune function in manatees.

Estrogen enhances mismatch repair by induction of MLH1 expression via estrogen receptor-β

PubMed Central

Lu, Jun-Yu; Jin, Peng; Gao, Wei; Wang, De-Zhi; Sheng, Jian-Qiu

2017-01-01

Epidemiological data demonstrated that hormone replace treatment has protective effect against colorectal cancer (CRC). Our previous studies showed that this effect may be associated with DNA mismatch repair. This study aims to investigate the mechanism of estrogen induction of MLH1, and whether colorectal tumor proliferation can be inhibited through induction of MLH1 by estrogen signal pathway. Human CRC cell lines were used to examine the regulation of MLH1 expression by over-expression and depletion of estrogen receptor-α (ERα) and estrogen receptor-β (ERβ), under the treatment with 17β-estradiol or β-Estradiol 6-(O-carboxy-methyl)oxime:BSA, followed by a real-time Q-PCR and Western blotting analysis. Luciferase reporter and chromatin immunoprecipitation assays were used to identify the estrogen response elements in the proximal promoter of MLH1 gene. Then, the influence of estrogen-induced MLH1 on CRC tumor growth were determined in vitro and in vivo. We found that mismatch repair ability and microsatellite stability of cells were enhanced by estrogen via induction of MLH1 expression, which was mediated by ERβ, through a transcriptional activation process. Furthermore, we identified that ERβ exerted an inhibitory effect on CRC tumor proliferation in vitro and in vivo, combined with 5-FU, through up-regulation of MLH1 expression. Finally, we concluded that estrogen enhances mismatch repair ability and tumor inhibition effect in vitro and in vivo, via induction of MLH1 expression mediated by ERβ. PMID:28404976

Estrogen enhances mismatch repair by induction of MLH1 expression via estrogen receptor-β.

PubMed

Lu, Jun-Yu; Jin, Peng; Gao, Wei; Wang, De-Zhi; Sheng, Jian-Qiu

2017-06-13

Epidemiological data demonstrated that hormone replace treatment has protective effect against colorectal cancer (CRC). Our previous studies showed that this effect may be associated with DNA mismatch repair. This study aims to investigate the mechanism of estrogen induction of MLH1, and whether colorectal tumor proliferation can be inhibited through induction of MLH1 by estrogen signal pathway. Human CRC cell lines were used to examine the regulation of MLH1 expression by over-expression and depletion of estrogen receptor-α (ERα) and estrogen receptor-β (ERβ), under the treatment with 17β-estradiol or β-Estradiol 6-(O-carboxy-methyl)oxime:BSA, followed by a real-time Q-PCR and Western blotting analysis. Luciferase reporter and chromatin immunoprecipitation assays were used to identify the estrogen response elements in the proximal promoter of MLH1 gene. Then, the influence of estrogen-induced MLH1 on CRC tumor growth were determined in vitro and in vivo. We found that mismatch repair ability and microsatellite stability of cells were enhanced by estrogen via induction of MLH1 expression, which was mediated by ERβ, through a transcriptional activation process. Furthermore, we identified that ERβ exerted an inhibitory effect on CRC tumor proliferation in vitro and in vivo, combined with 5-FU, through up-regulation of MLH1 expression. Finally, we concluded that estrogen enhances mismatch repair ability and tumor inhibition effect in vitro and in vivo, via induction of MLH1 expression mediated by ERβ.

A New lncRNA, APTR, Associates with and Represses the CDKN1A/p21 Promoter by Recruiting Polycomb Proteins

PubMed Central

Negishi, Masamitsu; Wongpalee, Somsakul P.; Sarkar, Sukumar; Park, Jonghoon; Lee, Kyung Yong; Shibata, Yoshiyuki; Reon, Brian J.; Abounader, Roger; Suzuki, Yutaka; Sugano, Sumio; Dutta, Anindya

2014-01-01

Long noncoding RNAs (lncRNAs) have emerged as a major regulator of cell physiology, but many of which have no known function. CDKN1A/p21 is an important inhibitor of the cell-cycle, regulator of the DNA damage response and effector of the tumor suppressor p53, playing a crucial role in tumor development and prevention. In order to identify a regulator for tumor progression, we performed an siRNA screen of human lncRNAs required for cell proliferation, and identified a novel lncRNA, APTR, that acts in trans to repress the CDKN1A/p21 promoter independent of p53 to promote cell proliferation. APTR associates with the promoter of CDKN1A/p21 and this association requires a complementary-Alu sequence encoded in APTR. A different module of APTR associates with and recruits the Polycomb repressive complex 2 (PRC2) to epigenetically repress the p21 promoter. A decrease in APTR is necessary for the induction of p21 after heat stress and DNA damage by doxorubicin, and the levels of APTR and p21 are anti-correlated in human glioblastomas. Our data identify a new regulator of the cell-cycle inhibitor CDKN1A/p21 that acts as a proliferative factor in cancer cell lines and in glioblastomas and demonstrate that Alu elements present in lncRNAs can contribute to targeting regulatory lncRNAs to promoters. PMID:24748121

Rufinamide, an antiepileptic drug, improves cognition and increases neurogenesis in the aged gerbil hippocampal dentate gyrus via increasing expressions of IGF-1, IGF-1R and p-CREB.

PubMed

Chen, Bai Hui; Ahn, Ji Hyeon; Park, Joon Ha; Song, Minah; Kim, Hyunjung; Lee, Tae-Kyeong; Lee, Jae Chul; Kim, Young-Myeong; Hwang, In Koo; Kim, Dae Won; Lee, Choong-Hyun; Yan, Bing Chun; Kang, Il Jun; Won, Moo-Ho

2018-04-25

Rufinamide is a novel antiepileptic drug and commonly used in the treatment of Lennox-Gastaut syndrome. In the present study, we investigated effects of rufinamide on cognitive function using passive avoidance test and neurogenesis in the hippocampal dentate gyrus using Ki-67 (a marker for cell proliferation), doublecortin (DCX, a marker for neuroblast) and BrdU/NeuN (markers for newly generated mature neurons) immunohistochemistry in aged gerbils. Aged gerbils (24-month old) were treated with 1 mg/kg and 3 mg/kg rufinamide for 4 weeks. Treatment with 3 mg/kg rufinamide, not 1 mg/kg rufinamide, significantly improved cognitive function and increased neurogenesis, showing that proliferating cells (Ki-67-immunoreactive cells), differentiating neuroblasts (DCX-immunoreactive neuroblasts) and mature neurons (BrdU/NeuN-immunoreactive cells) in the aged dentate gyrus compared with those in the control group. When we examined its mechanisms, rufinamide significantly increased immunoreactivities of insulin-like growth factor-1 (IGF-1), its receptor (IGF-1R), and phosphorylated cAMP response element binding protein (p-CREB). However, rufinamide did not show any increase in immunoreactivities of brain-derived neurotrophic factor and its receptor. Therefore, our results indicate that rufinamide can improve cognitive function and increase neurogenesis in the hippocampus of the aged gerbil via increasing expressions of IGF-1, IGF-1R and p-CREB. Copyright © 2018 Elsevier B.V. All rights reserved.

Decreased expression of peroxisome proliferator activated receptor gamma in cftr-/- mice.

PubMed

Ollero, Mario; Junaidi, Omer; Zaman, Munir M; Tzameli, Iphigenia; Ferrando, Adolfo A; Andersson, Charlotte; Blanco, Paola G; Bialecki, Eldad; Freedman, Steven D

2004-08-01

Some of the pathological manifestations of cystic fibrosis are in accordance with an impaired expression and/or activity of PPARgamma. We hypothesized that PPARgamma expression is altered in tissues lacking the normal cystic fibrosis transmembrane regulator protein (CFTR). PPARgamma mRNA levels were measured in colonic mucosa, ileal mucosa, adipose tissue, lung, and liver from wild-type and cftr-/- mice by quantitative RT-PCR. PPARgamma expression was decreased twofold in CFTR-regulated tissues (colon, ileum, and lung) from cftr-/- mice compared to wild-type littermates. In contrast, no differences were found in fat and liver. Immunohistochemical analysis of PPARgamma in ileum and colon revealed a predominantly nuclear localization in wild-type mucosal epithelial cells while tissues from cftr-/- mice showed a more diffuse, lower intensity labeling. A significant decrease in PPARgamma expression was confirmed in nuclear extracts of colon mucosa by Western blot analysis. In addition, binding of the PPARgamma/RXR heterodimer to an oligonucletotide containing a peroxisome proliferator responsive element (PPRE) was also decreased in colonic mucosa extracts from cftr-/- mice. Treatment of cftr-/- mice with the PPARgamma ligand rosiglitazone restored both the nuclear localization and binding to DNA, but did not increase RNA levels. We conclude that PPARgamma expression in cftr-/- mice is downregulated at the RNA and protein levels and its function diminished. These changes may be related to the loss of function of CFTR and may be relevant to the pathogenesis of metabolic abnormalities associated with cystic fibrosis in humans. Copyright 2004 Wiley-Liss, Inc.

Heme Oxygenase-1 Counteracts Contrast Media-Induced Endothelial Cell Dysfunction

PubMed Central

Chang, Chao-Fu; Liu, Xiao-Ming; Peyton, Kelly J.; Durante, William

2013-01-01

Endothelial cell (EC) dysfunction is involved in the pathogenesis of contrast-induced acute kidney injury, which is a major adverse event following coronary angiography. In this study, we evaluated the effect of contrast media (CM) on human EC proliferation, migration, and inflammation, and determined if heme oxygenase-1 (HO-1) influences the biological actions of CM. We found that three distinct CM, including high-osmolar (diatrizoate), low-osmolar (iopamidol), and iso-osmolar (iodixanol), stimulated the expression of HO-1 protein and mRNA. The induction of HO-1 was associated with an increase in NF-E2-related factor-2 (Nrf2) activity and reactive oxygen species (ROS). CM also stimulated HO-1 promoter activity and this was prevented by mutating the antioxidant responsive element or by overexpressing dominant-negative Nrf2. In addition, the CM-mediated induction of HO-1 and activation of Nrf2 was abolished by acetylcysteine. Finally, CM inhibited the proliferation and migration of ECs and stimulated the expression of intercellular adhesion molecule-1 and the adhesion of monocytes on ECs. Inhibition or silencing of HO-1 exacerbated the anti-proliferative and inflammatory actions of CM but had no effect on the anti-migratory effect. Thus, induction of HO-1 via the ROS-Nrf2 pathway counteracts the anti-proliferative and inflammatory actions of CM. Therapeutic approaches targeting HO-1 may provide a novel approach in preventing CM-induced endothelial and organ dysfunction. PMID:24239896

Activation of Peroxisome Proliferator-activated Receptor γ (PPARγ) and CD36 Protein Expression

PubMed Central

Yang, Xiaoxiao; Zhang, Wenwen; Chen, Yuanli; Li, Yan; Sun, Lei; Liu, Ying; Liu, Mengyang; Yu, Miao; Li, Xiaoju; Han, Jihong; Duan, Yajun

2016-01-01

Progesterone or its analog, one of components of hormone replacement therapy, may attenuate the cardioprotective effects of estrogen. However, the underlying mechanisms have not been fully elucidated. Expression of CD36, a receptor for oxidized LDL (oxLDL) that enhances macrophage/foam cell formation, is activated by the transcription factor peroxisome proliferator-activated receptor γ (PPARγ). CD36 also functions as a fatty acid transporter to influence fatty acid metabolism and the pathophysiological status of several diseases. In this study, we determined that progesterone induced macrophage CD36 expression, which is related to progesterone receptor (PR) activity. Progesterone enhanced cellular oxLDL uptake in a CD36-dependent manner. Mechanistically, progesterone increased PPARγ expression and PPARγ promoter activity in a PR-dependent manner and the binding of PR with the progesterone response element in the PPARγ promoter. Specific deletion of macrophage PPARγ (MφPPARγ KO) expression in mice abolished progesterone-induced macrophage CD36 expression and cellular oxLDL accumulation. We also determined that, associated with gestation and increased serum progesterone levels, CD36 and PPARγ expression in mouse adipose tissue, skeletal muscle, and peritoneal macrophages were substantially activated. Taken together, our study demonstrates that progesterone can play dual pathophysiological roles by activating PPARγ expression, in which progesterone increases macrophage CD36 expression and oxLDL accumulation, a negative effect on atherosclerosis, and enhances the PPARγ-CD36 pathway in adipose tissue and skeletal muscle, a protective effect on pregnancy. PMID:27226602

Ethanolic extract of dandelion (Taraxacum mongolicum) induces estrogenic activity in MCF-7 cells and immature rats.

PubMed

Oh, Seung Min; Kim, Ha Ryong; Park, Yong Joo; Lee, Yong Hwa; Chung, Kyu Hyuck

2015-11-01

Plants of the genus Taraxacum, commonly known as dandelions, are used to treat breast cancer in traditional folk medicine. However, their use has mainly been based on empirical findings without sufficient scientific evidence. Therefore, we hypothesized that dandelions would behave as a Selective estrogen receptor modulator (SERM) and be effective as hormone replacement therapy (HRT) in the postmenopausal women. In the present study, in vitro assay systems, including cell proliferation assay, reporter gene assay, and RT-PCR to evaluate the mRNA expression of estrogen-related genes (pS2 and progesterone receptor, PR), were performed in human breast cancer cells. Dandelion ethanol extract (DEE) significantly increased cell proliferation and estrogen response element (ERE)-driven luciferase activity. DEE significantly induced the expression of estrogen related genes such as pS2 and PR, which was inhibited by tamoxifen at 1 μmol·L(-1). These results indicated that DEE could induce estrogenic activities mediated by a classical estrogen receptor pathway. In addition, immature rat uterotrophic assay was carried out to identify estrogenic activity of DEE in vivo. The lowest concentration of DEE slightly increased the uterine wet weight, but there was no significant effect with the highest concentration of DEE. The results demonstrate the potential estrogenic activities of DEE, providing scientific evidence supporting their use in traditional medicine. Copyright © 2015 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.

Mesenchymal Stromal Cell Secreted Sphingosine 1-Phosphate (S1P) Exerts a Stimulatory Effect on Skeletal Myoblast Proliferation

PubMed Central

Tani, Alessia; Anderloni, Giulia; Pierucci, Federica; Matteini, Francesca; Chellini, Flaminia; Zecchi Orlandini, Sandra; Meacci, Elisabetta

2014-01-01

Bone-marrow-derived mesenchymal stromal cells (MSCs) have the potential to significantly contribute to skeletal muscle healing through the secretion of paracrine factors that support proliferation and enhance participation of the endogenous muscle stem cells in the process of repair/regeneration. However, MSC-derived trophic molecules have been poorly characterized. The aim of this study was to investigate paracrine signaling effects of MSCs on skeletal myoblasts. It was found, using a biochemical and morphological approach that sphingosine 1-phosphate (S1P), a natural bioactive lipid exerting a broad range of muscle cell responses, is secreted by MSCs and represents an important factor by which these cells exert their stimulatory effects on C2C12 myoblast and satellite cell proliferation. Indeed, exposure to conditioned medium obtained from MSCs cultured in the presence of the selective sphingosine kinase inhibitor (iSK), blocked increased cell proliferation caused by the conditioned medium from untreated MSCs, and the addition of exogenous S1P in the conditioned medium from MSCs pre-treated with iSK further increased myoblast proliferation. Finally, we also demonstrated that the myoblast response to MSC-secreted vascular endothelial growth factor (VEGF) involves the release of S1P from C2C12 cells. Our data may have important implications in the optimization of cell-based strategies to promote skeletal muscle regeneration. PMID:25264785

Multiple effects of TRAIL in human carcinoma cells: Induction of apoptosis, senescence, proliferation, and cytokine production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Levina, Vera; Marrangoni, Adele M.; DeMarco, Richard

TRAIL is a death ligand that induces apoptosis in malignant but not normal cells. Recently the ability of TRAIL to induce proliferation in apoptosis-resistant normal and malignant cells was reported. In this study, we analyzed TRAIL effects in apoptosis sensitive MCF7, OVCAR3 and H460 human tumor cell lines. TRAIL at low concentrations preferentially induced cell proliferation. At 100 ng/ml, apoptotic death was readily observed, however surviving cells acquired higher proliferative capacity. TRAIL-stimulated production of several cytokines, IL-8, RANTES, MCP-1 and bFGF, and activation of caspases 1 and 8 was essential for this effect. Antibodies to IL-8, RANTES, and bFGF blockedmore » TRAIL-induced cell proliferation and further stimulated apoptosis. For the first time, we report that high TRAIL concentrations induced cell senescence as determined by the altered morphology and expression of several senescence markers: SA-{beta}-gal, p21{sup Waf1/Cip1}, p16{sup INK4a}, and HMGA. Caspase 9 inhibition protected TRAIL-treated cells from senescence, whereas inhibition of caspases 1 and 8 increased the yield of SLP cells. In conclusion, in cultured human carcinoma cells, TRAIL therapy results in three functional outcomes, apoptosis, proliferation and senescence. TRAIL-induced proapoptotic and prosurvival responses correlate with the strength of signaling. TRAIL-induced cytokine production is responsible for its proliferative and prosurvival effects.« less

Low-dose naltrexone targets the opioid growth factor-opioid growth factor receptor pathway to inhibit cell proliferation: mechanistic evidence from a tissue culture model.

PubMed

Donahue, Renee N; McLaughlin, Patricia J; Zagon, Ian S

2011-09-01

Naltrexone (NTX) is an opioid antagonist that inhibits or accelerates cell proliferation in vivo when utilized in a low (LDN) or high (HDN) dose, respectively. The mechanism of opioid antagonist action on growth is not well understood. We established a tissue culture model of LDN and HDN using short-term and continuous opioid receptor blockade, respectively, in human ovarian cancer cells, and found that the duration of opioid receptor blockade determines cell proliferative response. The alteration of growth by NTX also was detected in cells representative of pancreatic, colorectal and squamous cell carcinomas. The opioid growth factor (OGF; [Met(5)]-enkephalin) and its receptor (OGFr) were responsible for mediating the action of NTX on cell proliferation. NTX upregulated OGF and OGFr at the translational but not at the transcriptional level. The mechanism of inhibition by short-term NTX required p16 and/or p21 cyclin-dependent inhibitory kinases, but was not dependent on cell survival (necrosis, apoptosis). Sequential administration of short-term NTX and OGF had a greater inhibitory effect on cell proliferation than either agent alone. Given the parallels between short-term NTX in vitro and LDN in vivo, we now demonstrate at the molecular level that the OGF-OGFr axis is a common pathway that is essential for the regulation of cell proliferation by NTX.

NRF2 Mediates Neuroblastoma Proliferation and Resistance to Retinoic Acid Cytotoxicity in a Model of In Vitro Neuronal Differentiation.

PubMed

de Miranda Ramos, Vitor; Zanotto-Filho, Alfeu; de Bittencourt Pasquali, Matheus Augusto; Klafke, Karina; Gasparotto, Juciano; Dunkley, Peter; Gelain, Daniel Pens; Moreira, José Cláudio Fonseca

2016-11-01

Retinoic acid (RA) morphogenetic properties have been used in different kinds of therapies, from neurodegenerative disorders to some types of cancer such as promyelocytic leukemia and neuroblastoma. However, most of the pathways responsible for RA effects remain unknown. To investigate such pathways, we used a RA-induced differentiation model in the human neuroblastoma cells, SH-SY5Y. Our data showed that n-acetyl-cysteine (NAC) reduced cells' proliferation rate and increased cells' sensitivity to RA toxicity. Simultaneously, NAC pre-incubation attenuated nuclear factor erythroid 2-like factor 2 (NRF2) activation by RA. None of these effects were obtained with Trolox ® as antioxidant, suggesting a cysteine signalization by RA. NRF2 knockdown increased cell sensibility to RA after 96 h of treatment and diminished neuroblastoma proliferation rate. Conversely, NRF2 overexpression limited RA anti-proliferative effects and increased cell proliferation. In addition, a rapid and non-genomic activation of the ERK 1/2 and PI3K/AKT pathways revealed to be equally required to promote NRF2 activation and necessary for RA-induced differentiation. Together, we provide data correlating NRF2 activity with neuroblastoma proliferation and resistance to RA treatments; thus, this pathway could be a potential target to optimize neuroblastoma chemotherapeutic response as well as in vitro neuronal differentiation protocols.

Islet inflammation and ductal proliferation may be linked to increased pancreatitis risk in type 2 diabetes

PubMed Central

Schludi, Belinda; Moin, Abu Saleh Md; Montemurro, Chiara; Gurlo, Tatyana; Matveyenko, Aleksey V.; Kirakossian, David; Dawson, David W.; Dry, Sarah M.; Butler, Peter C.; Butler, Alexandra E.

2017-01-01

Pancreatitis is more frequent in type 2 diabetes mellitus (T2DM), although the underlying cause is unknown. We tested the hypothesis that ongoing β cell stress and apoptosis in T2DM induces ductal tree proliferation, particularly the pancreatic duct gland (PDG) compartment, and thus potentially obstructs exocrine outflow, a well-established cause of pancreatitis. PDG replication was increased 2-fold in human pancreas from individuals with T2DM, and was associated with increased pancreatic intraepithelial neoplasia (PanIN), lesions associated with pancreatic inflammation and with the potential to obstruct pancreatic outflow. Increased PDG replication in the prediabetic human-IAPP-transgenic (HIP) rat model of T2DM was concordant with increased β cell stress but preceded metabolic derangement. Moreover, the most abundantly expressed chemokines released by the islets in response to β cell stress in T2DM, CXCL1, -4, and -10, induced proliferation in human pancreatic ductal epithelium. Also, the diabetes medications reported as potential modifiers for the risk of pancreatitis in T2DM modulated PDG proliferation accordingly. We conclude that chronic stimulation and proliferation of the PDG compartment in response to islet inflammation in T2DM is a potentially novel mechanism that serves as a link to the increased risk for pancreatitis in T2DM and may potentially be modified by currently available diabetes therapy. PMID:28679961

Islet amyloid polypeptide exerts a novel autocrine action in β-cell signaling and proliferation.

PubMed

Visa, Montse; Alcarraz-Vizán, Gema; Montane, Joel; Cadavez, Lisa; Castaño, Carlos; Villanueva-Peñacarrillo, María Luisa; Servitja, Joan-Marc; Novials, Anna

2015-07-01

The toxic effects of human islet amyloid polypeptide (IAPP) on pancreatic islets have been widely studied. However, much less attention has been paid to the physiologic actions of IAPP on pancreatic β cells, which secrete this peptide together with insulin upon glucose stimulation. Here, we aimed to explore the signaling pathways and mitogenic actions of IAPP on β cells. We show that IAPP activated Erk1/2 and v-akt murine thymoma viral oncogene homolog 1 (Akt) at the picomolar range (10-100 pM) in mouse pancreatic islets and MIN6 β cells cultured at low glucose concentrations. In contrast, IAPP decreased the induction of these pathways by high glucose levels. Consistently, IAPP induced a 1.7-fold increase of β-cell proliferation at low-glucose conditions, whereas it reduced β-cell proliferation at high glucose levels. Strikingly, the specific antagonist of the IAPP receptor AC187 (100 nM) decreased the activation of Erk1/2 and Akt and reduced β-cell proliferation by 24% in glucose-stimulated β cells, uncovering a key role of endogenously released IAPP in β-cell responses to glucose. We conclude that exogenously added IAPP exerts a dual effect on β-cell mitogenic signaling and proliferation, depending on the glucose concentration. Importantly, secreted IAPP contributes to the signaling and mitogenic response of β cells to glucose through an autocrine mechanism. © FASEB.

Impact of blue LED irradiation on proliferation and gene expression of cultured human keratinocytes

NASA Astrophysics Data System (ADS)

Becker, Anja; Sticht, Carsten; Dweep, Harsh; van Abeelen, Frank A.; Gretz, Norbert; Oversluizen, Gerrit

2015-03-01

Blue light is known for its anti-microbial, anti-proliferative and anti-inflammatory effects. Furthermore, it is already used for the treatment of neonatal jaundice and acne. However, little is known about the exact mechanisms of action on gene expression level. The aim of this study was to assess the impact of blue LED irradiation on the proliferation and gene expression in immortalized human keratinocytes (HaCaT) in vitro. Furthermore its safety was assessed. XTT-tests revealed a decrease in cell proliferation in blue light irradiated cells depending on the duration of light irradiation. Moreover, gene expression analysis demonstrated deregulated genes already 3 hours after blue light irradiation. 24 hours after blue light irradiation the effects seemed to be even more pronounced. The oxidative stress response was significantly increased, pointing to increased ROS production due to blue light, as well as steroid hormone biosynthesis. Downregulated pathways or biological processes were connected to anti-inflammatory response. Interestingly, also the melanoma pathway contained significantly downregulated genes 24 hours after blue light irradiation, which stands in accordance to literature that blue light can also inhibit proliferation in cancer cells. First tests with melanoma cells revealed a decrease in cell proliferation after blue light irradiation. In conclusion, blue light irradiation might open avenues to new therapeutic regimens; at least blue light seems to have no effect that induces cancer growth or formation.

CORE-SINEs: eukaryotic short interspersed retroposing elements with common sequence motifs.

PubMed

Gilbert, N; Labuda, D

1999-03-16

A 65-bp "core" sequence is dispersed in hundreds of thousands copies in the human genome. This sequence was found to constitute the central segment of a group of short interspersed elements (SINEs), referred to as mammalian-wide interspersed repeats, that proliferated before the radiation of placental mammals. Here, we propose that the core identifies an ancient tRNA-like SINE element, which survived in different lineages such as mammals, reptiles, birds, and fish, as well as mollusks, presumably for >550 million years. This element gave rise to a number of sequence families (CORE-SINEs), including mammalian-wide interspersed repeats, whose distinct 3' ends are shared with different families of long interspersed elements (LINEs). The evolutionary success of the generic CORE-SINE element can be related to the recruitment of the internal promoter from highly transcribed host RNA as well as to its capacity to adapt to changing retropositional opportunities by sequence exchange with actively amplifying LINEs. It reinforces the notion that the very existence of SINEs depends on the cohabitation with both LINEs and the host genome.

CORE-SINEs: Eukaryotic short interspersed retroposing elements with common sequence motifs

PubMed Central

Gilbert, Nicolas; Labuda, Damian

1999-01-01

A 65-bp “core” sequence is dispersed in hundreds of thousands copies in the human genome. This sequence was found to constitute the central segment of a group of short interspersed elements (SINEs), referred to as mammalian-wide interspersed repeats, that proliferated before the radiation of placental mammals. Here, we propose that the core identifies an ancient tRNA-like SINE element, which survived in different lineages such as mammals, reptiles, birds, and fish, as well as mollusks, presumably for >550 million years. This element gave rise to a number of sequence families (CORE-SINEs), including mammalian-wide interspersed repeats, whose distinct 3′ ends are shared with different families of long interspersed elements (LINEs). The evolutionary success of the generic CORE-SINE element can be related to the recruitment of the internal promoter from highly transcribed host RNA as well as to its capacity to adapt to changing retropositional opportunities by sequence exchange with actively amplifying LINEs. It reinforces the notion that the very existence of SINEs depends on the cohabitation with both LINEs and the host genome. PMID:10077603

In vivo responses of macrophages and perisinusoidal cells to cholestatic liver injury.

PubMed Central

Hines, J. E.; Johnson, S. J.; Burt, A. D.

1993-01-01

We investigated the response of macrophages and perisinusoidal (Ito) cells (PSCs) during the development of secondary biliary cirrhosis after ligation and division of the common bile duct. Liver tissue was obtained from three groups of male Wistar rats: 1) untreated controls (n = 3); 2) common bile duct-ligated (CBDL) animals (n = 15); and 3) sham-operated controls (n = 15). Material from animal groups 2 and 3 was obtained on days 3, 7, 14, 21, and 28 after operation; in all animals 5-bromo-2-deoxyuridine was administered intraperitoneally before death. Monocytes and macrophages were detected using the monoclonal antibody ED1 and tissue macrophages using the antibody ED2. Cell proliferation within the macrophage population was demonstrated by double labeling for ED2 and incorporated 5-bromo-2-deoxyuridine. PSCs were demonstrated in tissue sections by immunolocalization of desmin; proliferating PSCs were identified by double labeling for desmin and incorporated 5-bromo-2-deoxyuridine. Evidence of phenotypic modulation of PSCs was sought using anti-alpha-smooth muscle actin (alpha-SMA) antibody. Increased numbers of ED1- and ED2-positive cells were seen in CBDL animals at all time points. Local proliferation of macrophages could be identified and reached a peak at day 3, thereafter falling toward control values. Compared with those of controls, livers of CBDL animals showed increased numbers of desmin-positive PSCs in periportal zones from day 3 on, reaching a peak at day 14 (127.8 +/- 10.99 cells/0.635 mm2) and followed by a plateau. PSC proliferation peaked at days 3 and 7 (labeling indices 11.2% and 11.2%, respectively) and thereafter fell toward control values; no expansion of the PSC population was seen in sham-operated rats. Increased alpha-SMA-positive cells were also noted from day 3, with a peak at day 21 (231.1 +/- 11.52 cells/0.635 mm2) and followed by a plateau. En face labeling experiments in days 14, 21, and 28 CBDL animals showed cells co-expressing alpha-SMA and desmin and cells expressing alpha-SMA alone. These results indicate that in response to chronic cholestatic liver injury, PSCs proliferate and undergo phenotypic modulation toward "myofibroblast-like" cells. The kinetics of the response are similar to those of the ED2-positive cell population in keeping with a hypothesis that PSC proliferation and activation may be mediated by factors released by macrophages in response to various forms of liver injury. We conclude that the responses of macrophages and PSCs to cholestatic injury are similar to those after toxin-induced hepatocyte necrosis. Images Figure 2 Figure 4 Figure 5 Figure 6 PMID:8434646

TCDD promoted EMT of hFPECs via AhR, which involved the activation of EGFR/ERK signaling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gao, Zhan; The Fifth Affiliated Hospital, Zhengzhou University, 450052; Bu, Yongjun

2016-05-01

One critical step of second palatal fusion is the newly formed medial epithelia seam (MES) disintegration, which involves apoptosis, epithelial to mesenchymal transition (EMT), and cell migration. Although the environmental toxicant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) produces cleft palate at high rates, little is known about the effects of TCDD exposure on the fate of palatal epithelial cells. By using primary epithelial cells isolated from human fetal palatal shelves (hFPECs), we show that TCDD increased cell proliferation and EMT, as demonstrated by increased the epithelial markers (E-cadherin and cytokeratin14) and enhanced the mesenchymal markers (vimentin and fibronectin), but had no effect on cellmore » migration and apoptosis. TCDD exposure led to a dose-dependent increase in Slug protein expression. Coimmunoprecipitation revealed that TCDD promoted AhR to form a protein complex with Slug. ChIP assay confirmed that TCDD exposure recruited AhR to the xenobiotic responsive element of Slug promoter. Knockdown of AhR by siRNA remarkably weakened TCDD-induced binding of AhR to the XRE promoter of slug, thereby suppressed TCDD-induced vimentin. Further experiment showed that TCDD stimulated EGFR phosphorylation did not influence the TGFβ3/Smad signaling; whereas TCDD increased phosphorylation of ERK1/2 and p38 with no effect on activation of JNK. By using varieties of inhibitors, we confirmed that TCDD promoted proliferation and EMT of hFPECs via activation of EGFR/ERK pathway. These data make a novel contribution to the molecular mechanism of cleft palate by TCDD. - Highlights: • TCDD exposure promoted cell proliferation and EMT of hFPECs; • AhR signaling was activated and required for TCDD-induced EMT; • TCDD-mediated EMT of hFPECs involved the activation of EGFR/ERK signaling; • TCDD exposure had no effect on TGFβ3/Smad pathway.« less

The targeting expression of the vascular endothelial growth factor gene in endothelial cells regulated by HRE.ppET-1.

PubMed

Zheng, Xiangrong; Zhang, Shangshang; Yang, Yujia; Wang, Xia; Zhong, Le; Yu, Xiaohe

2008-11-01

The success of gene therapy depends largely on the efficacy of gene delivery vector systems that can deliver genes to target organs or cells selectively and efficiently with minimal toxicity. Here, we show that by using the HRE.ppET-1 regulatory element, we were able to restrict expression of the transgene of vascular endothelial growth factor (VEGF) to endothelial cells exclusively in hypoxic conditions. Eukaryotic expression vectors such as pEGFP-HRE.ppET-1, pcDNA3.1-VEGF+Pa, pcDNA3.1-ppET-1+ EGF+Pa, and pcDNA3.1-HRE.ppET-1+VEGF+Pa were constructed by using a series of nuclear molecule handling methods like PCR, enzyme digestion. The recombinant vectors were transfected into HUVEC cells and HL7702 cells by the lipofectin method. GFP expression was observed with a fluorescence microscope to validate the specificity of expression in endothelial cells under the regulation of HRE.ppET-1 element. Cobalt chloride (final concentration 100 mumol/L) was added to the medium to mimic hypoxia in vitro. After transfection of vectors, the expression of VEGF mRNA was detected by RT-PCR, and the expression of VEGF was detected by Western blotting and ELISA methods under normoxia and hypoxia, respectively. The cell proliferation rate was detected by the MTT test. The expression of GFP revealed that the exterior gene was transcripted effectively in endothelial cells regulated by the HRE.ppET-1 element, while the expression of GFP was very weak in nonendothelial cells. The results of RT-PCR, Western blotting and ELISA showed that VEGF gene expression in the pcDNA3.1-HRE.ppET-1+VEGF+Pa group and in the pcDNA3.1-ppET-1+VEGF+Pa group was higher in hypoxia than it was in normoxia (P<0.05). The MTT test showed that the proliferation rate of HUVEC transfected with HPVA under hypoxia exceeded that of the control group. We conclude that the HRE.ppET-1 element was expressed specifically in endothelial cells, and can increase the expression of VEGF in hypoxia and stimulate proliferation of endothelial cells. Taking advantage of these facts could greatly improve the efficiency of gene therapy. The vector would be valuable for various gene transfer studies targeting endothelial cells.

A Pdx-1-Regulated Soluble Factor Activates Rat and Human Islet Cell Proliferation

PubMed Central

Hayes, Heather L.; Zhang, Lu; Becker, Thomas C.; Haldeman, Jonathan M.; Stephens, Samuel B.; Arlotto, Michelle; Moss, Larry G.; Newgard, Christopher B.

2016-01-01

The homeodomain transcription factor Pdx-1 has important roles in pancreas and islet development as well as in β-cell function and survival. We previously reported that Pdx-1 overexpression stimulates islet cell proliferation, but the mechanism remains unclear. Here, we demonstrate that overexpression of Pdx-1 triggers proliferation largely by a non-cell-autonomous mechanism mediated by soluble factors. Consistent with this idea, overexpression of Pdx-1 under the control of a β-cell-specific promoter (rat insulin promoter [RIP]) stimulates proliferation of both α and β cells, and overexpression of Pdx-1 in islets separated by a Transwell membrane from islets lacking Pdx-1 overexpression activates proliferation in the untreated islets. Microarray and gene ontology (GO) analysis identified inhibin beta-B (Inhbb), an activin subunit and member of the transforming growth factor β (TGF-β) superfamily, as a Pdx-1-responsive gene. Overexpression of Inhbb or addition of activin B stimulates rat islet cell and β-cell proliferation, and the activin receptors RIIA and RIIB are required for the full proliferative effects of Pdx-1 in rat islets. In human islets, Inhbb overexpression stimulates total islet cell proliferation and potentiates Pdx-1-stimulated proliferation of total islet cells and β cells. In sum, this study identifies a mechanism by which Pdx-1 induces a soluble factor that is sufficient to stimulate both rat and human islet cell proliferation. PMID:27620967

Short interspersed DNA elements and miRNAs: a novel hidden gene regulation layer in zebrafish?

PubMed

Scarpato, Margherita; Angelini, Claudia; Cocca, Ennio; Pallotta, Maria M; Morescalchi, Maria A; Capriglione, Teresa

2015-09-01

In this study, we investigated by in silico analysis the possible correlation between microRNAs (miRNAs) and Anamnia V-SINEs (a superfamily of short interspersed nuclear elements), which belong to those retroposon families that have been preserved in vertebrate genomes for millions of years and are actively transcribed because they are embedded in the 3' untranslated region (UTR) of several genes. We report the results of the analysis of the genomic distribution of these mobile elements in zebrafish (Danio rerio) and discuss their involvement in generating miRNA gene loci. The computational study showed that the genes predicted to bear V-SINEs can be targeted by miRNAs with a very high hybridization E-value. Gene ontology analysis indicates that these genes are mainly involved in metabolic, membrane, and cytoplasmic signaling pathways. Nearly all the miRNAs that were predicted to target the V-SINEs of these genes, i.e., miR-338, miR-9, miR-181, miR-724, miR-735, and miR-204, have been validated in similar regulatory roles in mammals. The large number of genes bearing a V-SINE involved in metabolic and cellular processes suggests that V-SINEs may play a role in modulating cell responses to different stimuli and in preserving the metabolic balance during cell proliferation and differentiation. Although they need experimental validation, these preliminary results suggest that in the genome of D. rerio, as in other TE families in vertebrates, the preservation of V-SINE retroposons may also have been favored by their putative role in gene network modulation.

The MADS-box XAANTAL1 increases proliferation at the Arabidopsis root stem-cell niche and participates in transition to differentiation by regulating cell-cycle components.

PubMed

García-Cruz, Karla V; García-Ponce, Berenice; Garay-Arroyo, Adriana; Sanchez, María De La Paz; Ugartechea-Chirino, Yamel; Desvoyes, Bénédicte; Pacheco-Escobedo, Mario A; Tapia-López, Rosalinda; Ransom-Rodríguez, Ivan; Gutierrez, Crisanto; Alvarez-Buylla, Elena R

2016-07-29

Morphogenesis depends on the concerted modulation of cell proliferation and differentiation. Such modulation is dynamically adjusted in response to various external and internal signals via complex transcriptional regulatory networks that mediate between such signals and regulation of cell-cycle and cellular responses (proliferation, growth, differentiation). In plants, which are sessile, the proliferation/differentiation balance is plastically adjusted during their life cycle and transcriptional networks are important in this process. MADS-box genes are key developmental regulators in eukaryotes, but their role in cell proliferation and differentiation modulation in plants remains poorly studied. We characterize the XAL1 loss-of-function xal1-2 allele and overexpression lines using quantitative cellular and cytometry analyses to explore its role in cell cycle, proliferation, stem-cell patterning and transition to differentiation. We used quantitative PCR and cellular markers to explore if XAL1 regulates cell-cycle components and PLETHORA1 (PLT1) gene expression, as well as confocal microscopy to analyse stem-cell niche organization. We previously showed that XAANTAL1 (XAL1/AGL12) is necessary for Arabidopsis root development as a promoter of cell proliferation in the root apical meristem. Here, we demonstrate that XAL1 positively regulates the expression of PLT1 and important components of the cell cycle: CYCD3;1, CYCA2;3, CYCB1;1, CDKB1;1 and CDT1a In addition, we show that xal1-2 mutant plants have a premature transition to differentiation with root hairs appearing closer to the root tip, while endoreplication in these plants is partially compromised. Coincidently, the final size of cortex cells in the mutant is shorter than wild-type cells. Finally, XAL1 overexpression-lines corroborate that this transcription factor is able to promote cell proliferation at the stem-cell niche. XAL1 seems to be an important component of the networks that modulate cell proliferation/differentiation transition and stem-cell proliferation during Arabidopsis root development; it also regulates several cell-cycle components. © The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Controlling the leakage of liquid bismuth cathode elements in ceramic crucibles used for the electrowinning process in pyroprocessing

NASA Astrophysics Data System (ADS)

Kim, Dae-Young; Hwang, Il-Soon; Lee, Jong-Hyeon

2016-09-01

Pyroprocessing has shown promise as an alternative to wet processing for the recycling of transuranics with a high proliferation resistance. However, a critical issue for pyroprocessing is the ceramic crucibles used in the electrowinning process. These ceramic crucibles are frequently damaged by thermal stress, which results in significant volumes of crucible waste that must be properly disposed. Transuranic waste (TRU) elements intrude throughout the pores of a damaged crucible. The volume of generated radioactive waste is a concern when dealing with nuclear power plants and decontamination issues. In this study, laser treatment and sintering were performed on the crucibles to minimize the TRU elements trapped within. Secondary ion mass spectroscopy was used to measure the intrusion depth of Li in the surface-treated ceramics.

Towards the identification of the common features of bacterial biofilm development.

PubMed

Lasa, Iñigo

2006-03-01

Microorganisms can live and proliferate as individual cells swimming freely in the environment, or they can grow as highly organized, multicellular communities encased in a self-produced polymeric matrix in close association with surfaces and interfaces. This microbial lifestyle is referred to as biofilms. The intense search over the last few years for factors involved in biofilm development has revealed that distantly related bacterial species recurrently make use of the same elements to produce biofilms. These common elements include a group of proteins containing GGDEF/EAL domains, surface proteins homologous to Bap of Staphylococcus aureus, and some types of exopolysaccharides, such as cellulose and the poly-beta-1,6-N-acetylglucosamine. This review summarizes current knowledge about these three common elements and their role in biofilm development.

Assessing humoral and cell-mediated immune response in Hawaiian green turtles, Chelonia mydas

USGS Publications Warehouse

Work, Thierry M.; Balazs, George H.; Rameyer, Robert; Chang, S.P.; Berestecky, J.

2000-01-01

Seven immature green turtles, Chelonia mydas, captured from Kaneohe Bay on the island of Oahu were used to evaluate methods for assessing their immune response. Two turtles each were immunized intramuscularly with egg white lysozyme (EWL) in Freund’s complete adjuvant, Gerbu, or ISA-70; a seventh turtle was immunized with saline only and served as a control. Humoral immune response was measured with an indirect enzyme linked immunosorbent assay (ELISA). Cell-mediated immune response was measured using in vitro cell proliferation assays (CPA) using whole blood or peripheral blood mononuclear cells (PBM) cultured with concanavalin A (ConA), phytohaemagglutinin (PHA), or soluble egg EWL antigen. All turtles, except for one immunized with Gerbu and the control, produced a detectable humoral immune response by 6 weeks which persisted for at least 14 weeks after a single immunization. All turtles produced an anamnestic humoral immune response after secondary immunization. Antigen specific cell-mediated immune response in PBM was seen in all turtles either after primary or secondary immunization, but it was not as consistent as humoral immune response; antigen specific cell-mediated immune response in whole blood was rarely seen. Mononuclear cells had significantly higher stimulation indices than whole blood regardless of adjuvant, however, results with whole blood had lower variability. Both Gerbu and ISA-70 appeared to potentiate the cell-mediated immune response when PBM or whole blood were cultured with PHA. This is the first time cell proliferation assays have been compared between whole blood and PBM for reptiles. This is also the first demonstration of antigen specific cell-mediated response in reptiles. Cell proliferation assays allowed us to evaluate the cell-mediated immune response of green turtles. However, CPA may be less reliable than ELISA for detecting antigen specific immune response. Either of the three adjuvants appears suitable to safely elicit a detectable immune response in green turtles.

Nitric oxide regulates stretch-induced proliferation in C2C12 myoblasts.

PubMed

Soltow, Quinlyn A; Lira, Vitor A; Betters, Jenna L; Long, Jodi H D; Sellman, Jeff E; Zeanah, Elizabeth H; Criswell, David S

2010-09-01

Mechanical stretch of skeletal muscle activates nitric oxide (NO) production and is an important stimulator of satellite cell proliferation. Further, cyclooxygenase (COX) activity has been shown to promote satellite cell proliferation in response to stretch. Since COX-2 expression in skeletal muscle can be regulated by NO we sought to determine if NO is required for stretch-induced myoblast proliferation and whether supplemental NO can counter the effects of COX-2 and NF-kappaB inhibitors. C2C12 myoblasts were cultured for 24 h, then switched to medium containing either the NOS inhibitor, L-NAME (200 microM), the COX-2 specific inhibitor NS-398 (100 microM), the NF-kappaB inhibiting antioxidant, PDTC (5 mM), the nitric oxide donor, DETA-NONOate (10-100 microM) or no supplement (control) for 24 h. Subgroups of each treatment were exposed to 1 h of 15% cyclic stretch (1 Hz), and were then allowed to proliferate for 24 h before fixing. Proliferation was measured by BrdU incorporation during the last hour before fixing, and DAPI stain. Stretch induced a twofold increase in nuclear number compared to control, and this effect was completely inhibited by L-NAME, NS-398 or PDTC (P < 0.05). Although DETA-NONOate (10 microM) did not affect basal proliferation, the NO-donor augmented the stretch-induced increase in proliferation and rescued stretch-induced proliferation in NS-398-treated cells, but not in PDTC-treated cells. In conclusion, NO, COX-2, and NF-kappaB are necessary for stretch-induced proliferation of myoblasts. Although COX-2 and NF-kappaB are both involved in basal proliferation, NO does not affect basal growth. Thus, NO requires the synergistic effect of stretch in order to induce muscle cell proliferation.

Ki-67 staining for determination of rhesus macaque T cell proliferative responses ex vivo1

PubMed Central

Shedlock, Devon J.; Talbott, Kendra T.; Morrow, Matthew P.; Ferraro, Bernadette; Hokey, David A.; Muthumani, Karuppiah; Weiner, David B.

2010-01-01

The capacity for robust proliferation upon re-infection is a hallmark of adaptive immunity and the basis of vaccination. A widely used animal model for the study of human disease is the rhesus macaque (RM), where capacity for proliferation can be assessed ex vivo using carboxyfluorescein succinimidyl ester (CFSE)-based dilution assays. However, we show over the course of the standard ex vivo proliferation assay that CFSE-labeling at commonly-used dye concentrations induces significant cell death, but that this phenomenon is dose-dependent. Here we describe an alternative, semi-quantitative method for estimating T cell proliferative responses that avoids the putative biases associated with chemical modification. RM peripheral blood mononuclear cells were stimulated ex vivo with cognate peptides for five days, immunostained for intracellular Ki-67, and then analyzed by flow cytometry. We describe a gating strategy using Ki-67 and side light scatter, also a marker of blastogenesis, which correlates strongly with data from CFSE dilution. We show that this method is a valid tool for measuring RM antigen-specific cellular proliferation ex vivo and can be used as an alternative to CFSE dilution assays. PMID:20104580

Intestinal Cell Proliferation and Senescence Are Regulated by Receptor Guanylyl Cyclase C and p21*

PubMed Central

Basu, Nirmalya; Saha, Sayanti; Khan, Imran; Ramachandra, Subbaraya G.; Visweswariah, Sandhya S.

2014-01-01

Guanylyl cyclase C (GC-C) is expressed in intestinal epithelial cells and serves as the receptor for bacterial heat-stable enterotoxin (ST) peptides and the guanylin family of gastrointestinal hormones. Activation of GC-C elevates intracellular cGMP, which modulates intestinal fluid-ion homeostasis and differentiation of enterocytes along the crypt-villus axis. GC-C activity can regulate colonic cell proliferation by inducing cell cycle arrest, and mice lacking GC-C display increased cell proliferation in colonic crypts. Activation of GC-C by administration of ST to wild type, but not Gucy2c−/−, mice resulted in a reduction in carcinogen-induced aberrant crypt foci formation. In p53-deficient human colorectal carcinoma cells, ST led to a transcriptional up-regulation of p21, the cell cycle inhibitor, via activation of the cGMP-responsive kinase PKGII and p38 MAPK. Prolonged treatment of human colonic carcinoma cells with ST led to nuclear accumulation of p21, resulting in cellular senescence and reduced tumorigenic potential. Our results, therefore, identify downstream effectors for GC-C that contribute to regulating intestinal cell proliferation. Thus, genomic responses to a bacterial toxin can influence intestinal neoplasia and senescence. PMID:24217248

Low-level laser irradiation promotes the proliferation and maturation of keratinocytes during epithelial wound repair.

PubMed

Sperandio, Felipe F; Simões, Alyne; Corrêa, Luciana; Aranha, Ana Cecília C; Giudice, Fernanda S; Hamblin, Michael R; Sousa, Suzana C O M

2015-10-01

Low-level laser therapy (LLLT) has been extensively employed to improve epithelial wound healing, though the exact response of epithelium maturation and stratification after LLLT is unknown. Thus, this study aimed to assess the in vitro growth and differentiation of keratinocytes (KCs) and in vivo wound healing response when treated with LLLT. Human KCs (HaCaT cells) showed an enhanced proliferation with all the employed laser energy densities (3, 6 and 12 J/cm(2) , 660 nm, 100 mW), together with an increased expression of Cyclin D1. Moreover, the immunoexpression of proteins related to epithelial proliferation and maturation (p63, CK10, CK14) all indicated a faster maturation of the migrating KCs in the LLLT-treated wounds. In that way, an improved epithelial healing was promoted by LLLT with the employed parameters; this improvement was confirmed by changes in the expression of several proteins related to epithelial proliferation and maturation. Immunofluorescent expression of cytokeratin 10 (red) and Cyclin D1 (green) in (A) Control keratinocytes and (B) Low-level laser irradiated cells. Blue color illustrates the nuclei of the cells (DAPI staining). © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Different protein of Echinococcus granulosus stimulates dendritic induced immune response.

PubMed

Wang, Yana; Wang, Qiang; Lv, Shiyu; Zhang, Shengxiang

2015-06-01

Cystic echinococcosis is a chronic infectious disease that results from a host/parasite interaction. Vaccination with ferritin derived from Echinococcus granulosus is a potential preventative treatment. To understand whether ferritin is capable of inducing a host immune response, we investigated the response of dendritic cells (DCs) to both recombinant ferritin protein and the hydatid fluid (HF) of E. granulosus. We evaluated the immunomodulatory potential of these antigens by performing, immunocytochemistry, electron microscopy and in vivo imaging of monocyte-derived murine DCs. During antigen stimulation of DCs, ferritin cause DCs maturation and induced higher levels of surface marker expression and activated T-cell proliferation and migration. On contrary, HF failed to induce surface marker expression and to stimulate T-cell proliferation. In response to HF, DCs produced interleukin-6 (IL-6), but no IL-12 and IL-10. DCs stimulated with ferritin produced high levels of cytokines. Overall, HF appears to induce host immunosuppression in order to ensure parasite survival via inhibits DC maturation and promotes Th2-dependent secretion of cytokines. Although ferritin also promoted DC maturation and cytokine release, it also activates CD4+T-cell proliferation, but regard of the mechanism of the Eg.ferritin induce host to eradicate E. granulosus were not clear.

Chimera Analysis Supports a Predominant Role of PDGFRβ in Promoting Smooth-Muscle Cell Chemotaxis after Arterial Injury

PubMed Central

Buetow, Bernard S.; Tappan, Kristen A.; Crosby, Jeffrey R.; Seifert, Ronald A.; Bowen-Pope, Daniel F.

2003-01-01

The carotid artery shows a common response to many forms of injury, including a rapid activation of smooth muscle cell (SMC) proliferation in the media and migration of SMCs into the intima to form a neointima. Platelet-derived growth factor (PDGF) is believed to play a role in this response to injury, but it has proven difficult to distinguish whether it is stimulating cell migration or cell proliferation, and whether the action is direct or indirect. To determine this, we created chimeric mice composed of both wild-type (WT) and marked PDGF receptor β (PDGFRβ)-deficient cells, and determined the consequences of PDGFRβ expression for SMC participation in response to ligation of the left common carotid artery. The proportion of PDGFRβ−/− SMCs increased 4.5-fold in the media and decreased 1.8-fold during formation of the neointima, consistent with migration of WT SMCs out of the media and into the intima, leaving the PDGFRβ−/− cells behind. The fibrotic reaction in the adventitia, which does not involve cell migration, did not result in any change in relative abundance of WT and PDGFRβ-deficient fibroblasts. We conclude that the most significant direct role of PDGFRβ is to mediate responses that involve cell migration rather than proliferation. PMID:12937138

Role of G protein-coupled receptors (GPCR), matrix metalloproteinases 2 and 9 (MMP2 and MMP9), heparin-binding epidermal growth factor-like growth factor (hbEGF), epidermal growth factor receptor (EGFR), erbB2, and insulin-like growth factor 1 receptor (IGF-1R) in trenbolone acetate-stimulated bovine satellite cell proliferation.

PubMed

Thornton, K J; Kamange-Sollo, E; White, M E; Dayton, W R

2015-09-01

Implanting cattle with steroids significantly enhances feed efficiency, rate of gain, and muscle growth. However, the mechanisms responsible for these improvements in muscle growth have not been fully elucidated. Trenbolone acetate (TBA), a testosterone analog, has been shown to increase proliferation rate in bovine satellite cell (BSC) cultures. The classical genomic actions of testosterone have been well characterized; however, our results indicate that TBA may also initiate a quicker, nongenomic response that involves activation of G protein-coupled receptors (GPCR) resulting in activation of matrix metalloproteinases 2 and 9 (MMP2 and MMP9) that release membrane-bound heparin-binding epidermal growth factor-like growth factor (hbEGF), which then binds to and activates the epidermal growth factor receptor (EGFR) and/or erbB2. Furthermore, the EGFR has been shown to regulate expression of the IGF-1 receptor (IGF-1R), which is well known for its role in modulating muscle growth. To determine whether this nongenomic pathway is potentially involved in TBA-stimulated BSC proliferation, we analyzed the effects of treating BSC with guanosine 5'-O-2-thiodiphosphate (GDPβS), an inhibitor of all GPCR; a MMP2 and MMP9 inhibitor (MMPI); CRM19, a specific inhibitor of hbEGF; AG1478, a specific EGFR tyrosine kinase inhibitor; AG879, a specific erbB2 kinase inhibitor; and AG1024, an IGF-1R tyrosine kinase inhibitor on TBA-stimulated proliferation rate (H-thymidine incorporation). Assays were replicated at least 9 times for each inhibitor experiment using BSC cultures obtained from at least 3 different animals. Bovine satellite cell cultures were obtained from yearling steers that had no previous exposure to androgenic or estrogenic compounds. As expected, BSC cultures treated with 10 n TBA showed ( < 0.05) increased proliferation rate when compared with control cultures. Additionally, treatment with 5 ng hbEGF/mL stimulated proliferation in BSC cultures ( < 0.05). Treatment with GDPβS, MMPI, CRM197, AG1024, AG1478, and/or AG879 all suppressed ( < 0.05) TBA-induced increases in proliferation. These data indicate that TBA likely initiates a nongenomic response involving GPCR, MMP2 and MMP9, hbEGF, EGFR, erbB2, and IGF-1R, which may play a role in TBA-mediated increases in BSC proliferation.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heon, Elise K.; Wulan, Hasi; Macdonald, Loch P.

IL-15 has pivotal roles in the control of CD8{sup +} memory T cells and has been investigated as a therapeutic option in cancer therapy. Although IL-15 and IL-2 share many functions together, including the stimulation of CD8 T cell proliferation and IFN-γ production, the different in vivo roles of IL-15 and IL-2 have been increasingly recognized. Here, we explored the different effects of IL-15 and IL-2 on tumor-infiltrating (TI) T cells from resected breast tumors. We found that neither IL-2 nor IL-15 induced intratumoral CD8 T cell proliferation by itself, but after CD3/CD28-stimulation, IL-15 induced significantly higher proliferation than IL-2 duringmore » early time points, at day 2, day 3 and day 6. However, the IL-15-induced proliferation leveled off at day 9 and day 12, whereas IL-2 induced lower but progressive proliferation at each time point. Furthermore, IL-15 caused an early and robust increase of IFN-γ in the supernatant of TI cell cultures, which diminished at later time points, while the IL-2-induced IFN-γ production remained constant over time. In addition, the IL-15-costimulated CD8 T cells presented higher frequencies of apoptotic cells. The diminishing IL-15-induced response was possibly due to regulatory and/or exhaustion mechanisms. We did not observe increased IL-10 or PD-1 upregulation, but we have found an increase of Tim-3 upregulation on IL-15-, but not IL-2-stimulated cells. Blocking Tim-3 function using anti-Tim-3 antibodies resulted in increased IL-15-induced proliferation and IFN-γ production for a prolonged period of time, whereas adding Tim-3 ligand galectin 9 led to reduced proliferation and IFN-γ production. Our results suggest that IL-15 in combination of Tim-3 blocking antibodies could potentially act as an IL-2 alternative in tumor CD8 T cell expansion in vitro, a crucial step in adoptive T cell therapy. - Highlights: • We explored the effects of IL-15 and IL-2 on tumor-infiltrating (TI) T cells of breast cancer. • IL-15 and IL-2 had different kinetics in inducing TI CD8 T cell responses. • IL-15 induced stronger but shorter-lived TI CD8 T cell responses than IL-2. • IL-15, but not IL-2, caused upregulation of Tim-3 on TI CD8 T cells. • Blocking Tim-3 resulted in increased IL-15-induced proliferation and IFN-γ production in TI CD8 T cells.« less

Proliferation of Prostate Stromal Cell Induced by Benign Prostatic Hyperplasia Epithelial Cell Stimulated With Trichomonas vaginalis via Crosstalk With Mast Cell.

PubMed

Kim, Jung-Hyun; Kim, Sang-Su; Han, Ik-Hwan; Sim, Seobo; Ahn, Myoung-Hee; Ryu, Jae-Sook

2016-11-01

Chronic inflammation has a role in the pathogenesis of benign prostatic hyperplasia (BPH) and prostate cancer. Mast cells have been detected in chronic inflammatory infiltrate of the prostate, and it is possible that the interaction between prostate epithelial cells and Trichomonas vaginalis influences the activity of mast cells in the prostate stroma. Activated mast cells might influence the biological functions of nearby tissues and cells. In this study, we investigated whether mast cells reacted with the culture supernatant of BPH epithelial cells infected with T. vaginalis may induce the proliferation of prostate stromal cells. To measure the proliferation of prostate stromal cells in response to chronic inflammation caused by the infection of BPH-1 cells with T. vaginalis, the CCK-8 assay and wound healing assay were used. ELISAs, quantitative real-time PCR, western blotting and immunofluorescence were used to measure the production and expression of inflammatory cytokine and cytokine receptor. BPH-1 cells incubated with live trichomonads produced increased levels of CCL2, IL-1β, IL-6, and CXCL8, and induced the migration of mast cells and monocytes. When the culture supernatant of BPH-1 cells stimulated with trichomonads (TCM) was added to mast cells, they became activated, as confirmed by release of β-hexosaminidase and CXCL8. Prostate stromal cells incubated with the culture supernatant of mast cells activated with TCM (M-TCM) proliferated and expressed increased levels of CXCL8, CCL2, and the cytokine receptors CXCR1 and CCR2. Blocking the chemokine receptors reduced the proliferation of stromal cells and also decreased the production of CXCL8 and CCL2. Moreover, the expression of FGF2, cyclin D1, and Bcl-2 was increased in the proliferated stromal cells stimulated with M-TCM. Additionally, the M-TCM-treated stromal cells were more invasive than control cells. The inflammatory mediators released by BPH epithelial cells in response to infection by trichomonads induce the migration and activation of mast cells. The activated mast cells induce the proliferation of prostate stromal cells via CXCL8-CXCR1 and CCL2-CCR2 signaling. Our results therefore show that the inflammatory response by BPH epithelial cells stimulated with T. vaginalis induce the proliferation of prostate stromal cells via crosstalk with mast cells. Prostate 76:1431-1444, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Genome expansion and gene loss in powdery mildew fungi reveal functional tradeoffs in extreme parasitism

USDA-ARS?s Scientific Manuscript database

Eukaryotic genomes vary in size over five orders of magnitude ranging from microsporidia (~2.9Mb) to the lung-fish (~1.2Tb). This extraordinary variation is largely a result of the proliferation of mobile DNA elements also referred to as “genomic parasites.” The constraints on genome size may be imp...

Charter Schools and "Customer" Satisfaction: Lessons from Field Testing a Parent Survey

ERIC Educational Resources Information Center

Wohlstetter, Priscilla; Nayfack, Michelle B.; Mora-Flores, Eugenia

2008-01-01

Since the development of magnet schools in the 1960s--and more recently, the proliferation of charter schools in the last fifteen years--school choice has been a pervasive element on the education reform landscape. With this growth has come the need for information tools to help site-based educators manage, grow, and improve their schools. This is…

DNA transposon dynamics in populations of Daphnia pulex with and without sex.

PubMed

Schaack, Sarah; Pritham, Ellen J; Wolf, Abby; Lynch, Michael

2010-08-07

We investigate the role of recombination in transposable element (TE) proliferation in the cyclical parthenogen, Daphnia pulex. Recombination provides a mechanism by which the rate of both TE gain and loss can be accelerated, a duality that has long intrigued many biologists interested in the influence of sex on mutation accumulation. We compared TE loads among populations of D. pulex where sex occurs regularly (cyclical parthenogens or 'sexuals') with those in which the ability to reproduce sexually has been completely lost (obligate 'asexuals') for six different families of DNA transposons. Transposon display assays showed that sexuals have more TEs than asexuals, contrary to the expectations under Muller's ratchet but consistent with the idea that sex facilitates TE spread. Sexuals also exhibit higher insertion site polymorphism among lineages, as predicted because recombination accelerates rates of loss and gain. Asexuals, however, have proportionally more singletons (loci occupied in a single isolate), which differs from previous studies where selfing and outcrossing were used as a proxy for high and low recombination. Our multi-element survey reveals that the impact of sex on TE proliferation is consistent among different Class II TE families and we discuss the genomic consequences of different reproductive strategies over long time periods.

Hypothyroidism in utero stimulates pancreatic beta cell proliferation and hyperinsulinaemia in the ovine fetus during late gestation.

PubMed

Harris, Shelley E; De Blasio, Miles J; Davis, Melissa A; Kelly, Amy C; Davenport, Hailey M; Wooding, F B Peter; Blache, Dominique; Meredith, David; Anderson, Miranda; Fowden, Abigail L; Limesand, Sean W; Forhead, Alison J

2017-06-01

Thyroid hormones are important regulators of growth and maturation before birth, although the extent to which their actions are mediated by insulin and the development of pancreatic beta cell mass is unknown. Hypothyroidism in fetal sheep induced by removal of the thyroid gland caused asymmetric organ growth, increased pancreatic beta cell mass and proliferation, and was associated with increased circulating concentrations of insulin and leptin. In isolated fetal sheep islets studied in vitro, thyroid hormones inhibited beta cell proliferation in a dose-dependent manner, while high concentrations of insulin and leptin stimulated proliferation. The developing pancreatic beta cell is therefore sensitive to thyroid hormone, insulin and leptin before birth, with possible consequences for pancreatic function in fetal and later life. The findings of this study highlight the importance of thyroid hormones during pregnancy for normal development of the fetal pancreas. Development of pancreatic beta cell mass before birth is essential for normal growth of the fetus and for long-term control of carbohydrate metabolism in postnatal life. Thyroid hormones are also important regulators of fetal growth, and the present study tested the hypotheses that thyroid hormones promote beta cell proliferation in the fetal ovine pancreatic islets, and that growth retardation in hypothyroid fetal sheep is associated with reductions in pancreatic beta cell mass and circulating insulin concentration in utero. Organ growth and pancreatic islet cell proliferation and mass were examined in sheep fetuses following removal of the thyroid gland in utero. The effects of triiodothyronine (T 3 ), insulin and leptin on beta cell proliferation rates were determined in isolated fetal ovine pancreatic islets in vitro. Hypothyroidism in the sheep fetus resulted in an asymmetric pattern of organ growth, pancreatic beta cell hyperplasia, and elevated plasma insulin and leptin concentrations. In pancreatic islets isolated from intact fetal sheep, beta cell proliferation in vitro was reduced by T 3 in a dose-dependent manner and increased by insulin at high concentrations only. Leptin induced a bimodal response whereby beta cell proliferation was suppressed at the lowest, and increased at the highest, concentrations. Therefore, proliferation of beta cells isolated from the ovine fetal pancreas is sensitive to physiological concentrations of T 3 , insulin and leptin. Alterations in these hormones may be responsible for the increased beta cell proliferation and mass observed in the hypothyroid sheep fetus and may have consequences for pancreatic function in later life. © 2017 The Authors. The Journal of Physiology published by John Wiley & Sons Ltd on behalf of The Physiological Society.

Epigenetic regulation of transcription and possible functions of mammalian short interspersed elements, SINEs.

PubMed

Ichiyanagi, Kenji

2013-01-01

Short interspersed elements (SINEs) are a class of retrotransposons, which amplify their copy numbers in their host genomes by retrotransposition. More than a million copies of SINEs are present in a mammalian genome, constituting over 10% of the total genomic sequence. In contrast to the other two classes of retrotransposons, long interspersed elements (LINEs) and long terminal repeat (LTR) elements, SINEs are transcribed by RNA polymerase III. However, like LINEs and LTR elements, the SINE transcription is likely regulated by epigenetic mechanisms such as DNA methylation, at least for human Alu and mouse B1. Whereas SINEs and other transposable elements have long been thought as selfish or junk DNA, recent studies have revealed that they play functional roles at their genomic locations, for example, as distal enhancers, chromatin boundaries and binding sites of many transcription factors. These activities imply that SINE retrotransposition has shaped the regulatory network and chromatin landscape of their hosts. Whereas it is thought that the epigenetic mechanisms were originated as a host defense system against proliferation of parasitic elements, this review discusses a possibility that the same mechanisms are also used to regulate the SINE-derived functions.

Extracellular matrix elasticity and topography: material-based cues that affect cell function via conserved mechanisms

PubMed Central

Janson, Isaac A.; Putnam, Andrew J.

2014-01-01

Chemical, mechanical, and topographic extracellular matrix (ECM) cues have been extensively studied for their influence on cell behavior. These ECM cues alter cell adhesion, cell shape, and cell migration, and activate signal transduction pathways to influence gene expression, proliferation, and differentiation. ECM elasticity and topography, in particular, have emerged as material properties of intense focus based on strong evidence these physical cue can partially dictate stem cell differentiation. Cells generate forces to pull on their adhesive contacts, and these tractional forces appear to be a common element of cells’ responses to both elasticity and topography. This review focuses on recently published work that links ECM topography and mechanics and their influence on differentiation and other cell behaviors, We also highlight signaling pathways typically implicated in mechanotransduction that are (or may be) shared by cells subjected to topographic cues. Finally, we conclude with a brief discussion of the potential implications of these commonalities for cell based therapies and biomaterial design. PMID:24910444

The goat mammary glandular epithelial (GMGE) cell line promotes polyfucosylation and N,N'-diacetyllactosediaminylation of N-glycans linked to recombinant human erythropoietin.

PubMed

Sánchez, O; Montesino, R; Toledo, J R; Rodríguez, E; Díaz, D; Royle, L; Rudd, P M; Dwek, R A; Gerwig, G J; Kamerling, J P; Harvey, D J; Cremata, J A

2007-08-15

We have established a continuous, non-transformed cell line from primary cultures from Capra hircus mammary gland. Low-density cultures showed a homogeneous epithelial morphology without detectable fibroblastic or myoepithelial cells. The culture was responsive to contact inhibition of proliferation and its doubling time was dependent on the presence of insulin and epidermal growth factor (EGF). GMGE cells secrete caseins regardless of the presence or absence of lactogenic hormones in the culture media. Investigation of the total N-glycan pool of human erythropoietin (rhEPO) expressed in GMGE cells by monosaccharide analysis, HPLC profiling, and mass spectrometry, indicated significant differences with respect to the same protein expressed in Chinese hamster ovary (CHO) cells. N-Glycans of rhEPO-GMGE are core-fucosylated, but fucosylation of outer arms was also found. Our results also revealed the presence of low levels of sialylation (>95% Neu5Ac), N,N'-diacetyllactosediamine units, and possibly Gal-Gal non-reducing terminal elements.

Co-evolution of plant LTR-retrotransposons and their host genomes.

PubMed

Zhao, Meixia; Ma, Jianxin

2013-07-01

Transposable elements (TEs), particularly, long terminal repeat retrotransposons (LTR-RTs), are the most abundant DNA components in all plant species that have been investigated, and are largely responsible for plant genome size variation. Although plant genomes have experienced periodic proliferation and/or recent burst of LTR-retrotransposons, the majority of LTR-RTs are inactivated by DNA methylation and small RNA-mediated silencing mechanisms, and/or were deleted/truncated by unequal homologous recombination and illegitimate recombination, as suppression mechanisms that counteract genome expansion caused by LTR-RT amplification. LTR-RT DNA is generally enriched in pericentromeric regions of the host genomes, which appears to be the outcomes of preferential insertions of LTR-RTs in these regions and low effectiveness of selection that purges LTR-RT DNA from these regions relative to chromosomal arms. Potential functions of various TEs in their host genomes remain blurry; nevertheless, LTR-RTs have been recognized to play important roles in maintaining chromatin structures and centromere functions and regulation of gene expressions in their host genomes.

Nuclear PTEN functions as an essential regulator of SRF-dependent transcription to control smooth muscle differentiation

PubMed Central

Horita, Henrick; Wysoczynski, Christina L.; Walker, Lori A.; Moulton, Karen S.; Li, Marcella; Ostriker, Allison; Tucker, Rebecca; McKinsey, Timothy A.; Churchill, Mair E. A.; Nemenoff, Raphael A.; Weiser-Evans, Mary C. M.

2016-01-01

Vascular disease progression is associated with marked changes in vascular smooth muscle cell (SMC) phenotype and function. SMC contractile gene expression and, thus differentiation, is under direct transcriptional control by the transcription factor, serum response factor (SRF); however, the mechanisms dynamically regulating SMC phenotype are not fully defined. Here we report that the lipid and protein phosphatase, PTEN, has a novel role in the nucleus by functioning as an indispensible regulator with SRF to maintain the differentiated SM phenotype. PTEN interacts with the N-terminal domain of SRF and PTEN–SRF interaction promotes SRF binding to essential promoter elements in SM-specific genes. Factors inducing phenotypic switching promote loss of nuclear PTEN through nucleo-cytoplasmic translocation resulting in reduced myogenically active SRF, but enhanced SRF activity on target genes involved in proliferation. Overall decreased expression of PTEN was observed in intimal SMCs of human atherosclerotic lesions underlying the potential clinical importance of these findings. PMID:26940659

Nuclear PTEN functions as an essential regulator of SRF-dependent transcription to control smooth muscle differentiation.

PubMed

Horita, Henrick; Wysoczynski, Christina L; Walker, Lori A; Moulton, Karen S; Li, Marcella; Ostriker, Allison; Tucker, Rebecca; McKinsey, Timothy A; Churchill, Mair E A; Nemenoff, Raphael A; Weiser-Evans, Mary C M

2016-03-04

Vascular disease progression is associated with marked changes in vascular smooth muscle cell (SMC) phenotype and function. SMC contractile gene expression and, thus differentiation, is under direct transcriptional control by the transcription factor, serum response factor (SRF); however, the mechanisms dynamically regulating SMC phenotype are not fully defined. Here we report that the lipid and protein phosphatase, PTEN, has a novel role in the nucleus by functioning as an indispensible regulator with SRF to maintain the differentiated SM phenotype. PTEN interacts with the N-terminal domain of SRF and PTEN-SRF interaction promotes SRF binding to essential promoter elements in SM-specific genes. Factors inducing phenotypic switching promote loss of nuclear PTEN through nucleo-cytoplasmic translocation resulting in reduced myogenically active SRF, but enhanced SRF activity on target genes involved in proliferation. Overall decreased expression of PTEN was observed in intimal SMCs of human atherosclerotic lesions underlying the potential clinical importance of these findings.

Metabolic reprogramming during TGFβ1-induced epithelial-to-mesenchymal transition

PubMed Central

Jiang, Lei; Xiao, Ling; Sugiura, Hidekazu; Huang, Xiumei; Ali, Aktar; Kuro-o, Makoto; Deberardinis, Ralph J.; Boothman, David A.

2014-01-01

Metastatic progression, including extravasation and micro-metastatic outgrowth, is the main cause of cancer patient death. Recent studies suggest that cancer cells reprogram their metabolism to support increased proliferation through increased glycolysis and biosynthetic activities, including lipogenesis pathways. However, metabolic changes during metastatic progression, including alterations in regulatory gene expression, remain undefined. We show that transforming growth factor beta 1 (TGFβ1) induced Epithelial-to-Mesenchymal Transition (EMT) is accompanied by coordinately reduced enzyme expression required to convert glucose into fatty acids, and concomitant enhanced respiration. Over-expressed Snail1, a transcription factor mediating TGFβ1-induced EMT, was sufficient to suppress carbohydrate-responsive-element-binding protein (ChREBP, a master lipogenic regulator), and fatty acid synthase (FASN), its effector lipogenic gene. Stable FASN knock-down was sufficient to induce EMT, stimulate migration and extravasation in vitro. FASN silencing enhanced lung metastasis and death in vivo. These data suggest that a metabolic transition that suppresses lipogenesis and favors energy production is an essential component of TGFβ1-induced EMT and metastasis. PMID:25284588