d-Xylose Degradation Pathway in the Halophilic Archaeon Haloferax volcanii

PubMed Central

Johnsen, Ulrike; Dambeck, Michael; Zaiss, Henning; Fuhrer, Tobias; Soppa, Jörg; Sauer, Uwe; Schönheit, Peter

2009-01-01

The pathway of d-xylose degradation in archaea is unknown. In a previous study we identified in Haloarcula marismortui the first enzyme of xylose degradation, an inducible xylose dehydrogenase (Johnsen, U., and Schönheit, P. (2004) J. Bacteriol. 186, 6198–6207). Here we report a comprehensive study of the complete d-xylose degradation pathway in the halophilic archaeon Haloferax volcanii. The analyses include the following: (i) identification of the degradation pathway in vivo following 13C-labeling patterns of proteinogenic amino acids after growth on [13C]xylose; (ii) identification of xylose-induced genes by DNA microarray experiments; (iii) characterization of enzymes; and (iv) construction of in-frame deletion mutants and their functional analyses in growth experiments. Together, the data indicate that d-xylose is oxidized exclusively to the tricarboxylic acid cycle intermediate α-ketoglutarate, involving d-xylose dehydrogenase (HVO_B0028), a novel xylonate dehydratase (HVO_B0038A), 2-keto-3-deoxyxylonate dehydratase (HVO_B0027), and α-ketoglutarate semialdehyde dehydrogenase (HVO_B0039). The functional involvement of these enzymes in xylose degradation was proven by growth studies of the corresponding in-frame deletion mutants, which all lost the ability to grow on d-xylose, but growth on glucose was not significantly affected. This is the first report of an archaeal d-xylose degradation pathway that differs from the classical d-xylose pathway in most bacteria involving the formation of xylulose 5-phosphate as an intermediate. However, the pathway shows similarities to proposed oxidative pentose degradation pathways to α-ketoglutarate in few bacteria, e.g. Azospirillum brasilense and Caulobacter crescentus, and in the archaeon Sulfolobus solfataricus. PMID:19584053

GlpR is a direct transcriptional repressor of fructose metabolic genes in Haloferax volcanii.

PubMed

Martin, Jonathan H; Rawls, Katie Sherwood; Chan, Jou Chin; Hwang, Sungmin; Martinez-Pastor, Mar; McMillan, Lana J; Prunetti, Laurence; Schmid, Amy K; Maupin-Furlow, Julie A

2018-06-18

DeoR-type helix-turn-helix (HTH) domain proteins are transcriptional regulators of sugar and nucleoside metabolism in diverse bacteria and occur in select archaea. In the model archaeon Haloferax volcanii , previous work implicated GlpR, a DeoR-type transcriptional regulator, in transcriptional repression of glpR and the gene encoding the fructose-specific phosphofructokinase ( pfkB ) during growth on glycerol. However, the global regulon governed by GlpR remained unclear. Here we compared transcriptomes of wild type and Δ glpR mutant strains grown on glycerol and glucose to detect significant transcript level differences for nearly 50 new genes regulated by GlpR. By coupling computational prediction of GlpR binding sequences with in vivo and in vitro DNA binding experiments, we determined that GlpR directly controls genes encoding enzymes in fructose degradation, including fructose bisphosphate aldolase, a central control point in glycolysis. GlpR also directly controls other transcription factors. In contrast, other metabolic pathways appear to be under indirect influence of GlpR. In vitro experiments demonstrated that GlpR purifies as a tetramer that binds the effector molecule fructose-1-phosphate (F1P). These results suggest that Hfx. volcanii GlpR functions as a direct negative regulator of fructose degradation during growth on carbon sources other than fructose, such as glucose and glycerol, and that GlpR bears striking functional similarity to bacterial DeoR-type regulators. IMPORTANCE Many archaea are extremophiles, able to thrive in habitats of extreme salinity, pH and temperature. These biological properties are ideal for applications in biotechnology. However, limited knowledge of archaeal metabolism is a bottleneck that prevents broad use of archaea as microbial factories for industrial products. Here we characterize how sugar uptake and use is regulated in a species that lives in high salinity. We demonstrate that a key sugar regulatory protein in

Comparative genomic analysis of the Haloferax volcanii DS2 and Halobacterium salinarium GRB contig maps reveals extensive rearrangement.

PubMed Central

St Jean, A; Charlebois, R L

1996-01-01

Anonymous probes from the genome of Halobacterium salinarium GRB and 12 gene probes were hybridized to the cosmid clones representing the chromosome and plasmids of Halobacterium salinarium GRB and Haloferax volcanii DS2. The order of and pairwise distances between 35 loci uniquely cross-hybridizing to both chromosomes were analyzed in a search for conservation. No conservation between the genomes could be detected at the 15-kbp resolution used in this study. We found distinct sets of low-copy-number repeated sequences in the chromosome and plasmids of Halobacterium salinarium GRB, indicating some degree of partitioning between these replicons. We propose alternative courses for the evolution of the haloarchaeal genome: (i) that the majority of genomic differences that exist between genera came about at the inception of this group or (ii) that the differences have accumulated over the lifetime of the lineage. The strengths and limitations of investigating these models through comparative genomic studies are discussed. PMID:8682791

DNA replication restart and cellular dynamics of Hef helicase/nuclease protein in Haloferax volcanii.

PubMed

Lestini, Roxane; Delpech, Floriane; Myllykallio, Hannu

2015-11-01

Understanding how frequently spontaneous replication arrests occur and how archaea deal with these arrests are very interesting and challenging research topics. Here we will described how genetic and imaging studies have revealed the central role of the archaeal helicase/nuclease Hef belonging to the XPF/MUS81/FANCM family of endonucleases in repair of arrested replication forks. Special focus will be on description of a recently developed combination of genetic and imaging tools to study the dynamic localization of a functional Hef::GFP (Green Fluorescent Protein) fusion protein in the living cells of halophilic archaea Haloferax volcanii. As Archaea provide an excellent and unique model for understanding how DNA replication is regulated to allow replication of a circular DNA molecule either from single or multiple replication origins, we will also summarize recent studies that have revealed peculiar features regarding DNA replication, particularly in halophilic archaea. We strongly believe that fundamental knowledge of our on-going studies will shed light on the evolutionary history of the DNA replication machinery and will help to establish general rules concerning replication restart and the key role of recombination proteins not only in bacteria, yeast and higher eukaryotes but also in archaea. Copyright © 2015 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

RNomics and Modomics in the halophilic archaea Haloferax volcanii: identification of RNA modification genes

PubMed Central

Grosjean, Henri; Gaspin, Christine; Marck, Christian; Decatur, Wayne A; de Crécy-Lagard, Valérie

2008-01-01

Background Naturally occurring RNAs contain numerous enzymatically altered nucleosides. Differences in RNA populations (RNomics) and pattern of RNA modifications (Modomics) depends on the organism analyzed and are two of the criteria that distinguish the three kingdoms of life. If the genomic sequences of the RNA molecules can be derived from whole genome sequence information, the modification profile cannot and requires or direct sequencing of the RNAs or predictive methods base on the presence or absence of the modifications genes. Results By employing a comparative genomics approach, we predicted almost all of the genes coding for the t+rRNA modification enzymes in the mesophilic moderate halophile Haloferax volcanii. These encode both guide RNAs and enzymes. Some are orthologous to previously identified genes in Archaea, Bacteria or in Saccharomyces cerevisiae, but several are original predictions. Conclusion The number of modifications in t+rRNAs in the halophilic archaeon is surprisingly low when compared with other Archaea or Bacteria, particularly the hyperthermophilic organisms. This may result from the specific lifestyle of halophiles that require high intracellular salt concentration for survival. This salt content could allow RNA to maintain its functional structural integrity with fewer modifications. We predict that the few modifications present must be particularly important for decoding, accuracy of translation or are modifications that cannot be functionally replaced by the electrostatic interactions provided by the surrounding salt-ions. This analysis also guides future experimental validation work aiming to complete the understanding of the function of RNA modifications in Archaeal translation. PMID:18844986

Permuting the PGF Signature Motif Blocks both Archaeosortase-Dependent C-Terminal Cleavage and Prenyl Lipid Attachment for the Haloferax volcanii S-Layer Glycoprotein.

PubMed

Abdul Halim, Mohd Farid; Karch, Kelly R; Zhou, Yitian; Haft, Daniel H; Garcia, Benjamin A; Pohlschroder, Mechthild

2015-12-28

For years, the S-layer glycoprotein (SLG), the sole component of many archaeal cell walls, was thought to be anchored to the cell surface by a C-terminal transmembrane segment. Recently, however, we demonstrated that the Haloferax volcanii SLG C terminus is removed by an archaeosortase (ArtA), a novel peptidase. SLG, which was previously shown to be lipid modified, contains a C-terminal tripartite structure, including a highly conserved proline-glycine-phenylalanine (PGF) motif. Here, we demonstrate that ArtA does not process an SLG variant where the PGF motif is replaced with a PFG motif (slg(G796F,F797G)). Furthermore, using radiolabeling, we show that SLG lipid modification requires the PGF motif and is ArtA dependent, lending confirmation to the use of a novel C-terminal lipid-mediated protein-anchoring mechanism by prokaryotes. Similar to the case for the ΔartA strain, the growth, cellular morphology, and cell wall of the slg(G796F,F797G) strain, in which modifications of additional H. volcanii ArtA substrates should not be altered, are adversely affected, demonstrating the importance of these posttranslational SLG modifications. Our data suggest that ArtA is either directly or indirectly involved in a novel proteolysis-coupled, covalent lipid-mediated anchoring mechanism. Given that archaeosortase homologs are encoded by a broad range of prokaryotes, it is likely that this anchoring mechanism is widely conserved. Prokaryotic proteins bound to cell surfaces through intercalation, covalent attachment, or protein-protein interactions play critical roles in essential cellular processes. Unfortunately, the molecular mechanisms that anchor proteins to archaeal cell surfaces remain poorly characterized. Here, using the archaeon H. volcanii as a model system, we report the first in vivo studies of a novel protein-anchoring pathway involving lipid modification of a peptidase-processed C terminus. Our findings not only yield important insights into poorly understood

Fructose Degradation in the Haloarchaeon Haloferax volcanii Involves a Bacterial Type Phosphoenolpyruvate-Dependent Phosphotransferase System, Fructose-1-Phosphate Kinase, and Class II Fructose-1,6-Bisphosphate Aldolase

PubMed Central

Pickl, Andreas; Johnsen, Ulrike

2012-01-01

The halophilic archaeon Haloferax volcanii utilizes fructose as a sole carbon and energy source. Genes and enzymes involved in fructose uptake and degradation were identified by transcriptional analyses, deletion mutant experiments, and enzyme characterization. During growth on fructose, the gene cluster HVO_1495 to HVO_1499, encoding homologs of the five bacterial phosphotransferase system (PTS) components enzyme IIB (EIIB), enzyme I (EI), histidine protein (HPr), EIIA, and EIIC, was highly upregulated as a cotranscript. The in-frame deletion of HVO_1499, designated ptfC (ptf stands for phosphotransferase system for fructose) and encoding the putative fructose-specific membrane component EIIC, resulted in a loss of growth on fructose, which could be recovered by complementation in trans. Transcripts of HVO_1500 (pfkB) and HVO_1494 (fba), encoding putative fructose-1-phosphate kinase (1-PFK) and fructose-1,6-bisphosphate aldolase (FBA), respectively, as well as 1-PFK and FBA activities were specifically upregulated in fructose-grown cells. pfkB and fba knockout mutants did not grow on fructose, whereas growth on glucose was not inhibited, indicating the functional involvement of both enzymes in fructose catabolism. Recombinant 1-PFK and FBA obtained after homologous overexpression were characterized as having kinetic properties indicative of functional 1-PFK and a class II type FBA. From these data, we conclude that fructose uptake in H. volcanii involves a fructose-specific PTS generating fructose-1-phosphate, which is further converted via fructose-1,6-bisphosphate to triose phosphates by 1-PFK and FBA. This is the first report of the functional involvement of a bacterial-like PTS and of class II FBA in the sugar metabolism of archaea. PMID:22493022

A complex of Cas proteins 5, 6, and 7 is required for the biogenesis and stability of clustered regularly interspaced short palindromic repeats (crispr)-derived rnas (crrnas) in Haloferax volcanii.

PubMed

Brendel, Jutta; Stoll, Britta; Lange, Sita J; Sharma, Kundan; Lenz, Christof; Stachler, Aris-Edda; Maier, Lisa-Katharina; Richter, Hagen; Nickel, Lisa; Schmitz, Ruth A; Randau, Lennart; Allers, Thorsten; Urlaub, Henning; Backofen, Rolf; Marchfelder, Anita

2014-03-07

The clustered regularly interspaced short palindromic repeats/CRISPR-associated (CRISPR-Cas) system is a prokaryotic defense mechanism against foreign genetic elements. A plethora of CRISPR-Cas versions exist, with more than 40 different Cas protein families and several different molecular approaches to fight the invading DNA. One of the key players in the system is the CRISPR-derived RNA (crRNA), which directs the invader-degrading Cas protein complex to the invader. The CRISPR-Cas types I and III use the Cas6 protein to generate mature crRNAs. Here, we show that the Cas6 protein is necessary for crRNA production but that additional Cas proteins that form a CRISPR-associated complex for antiviral defense (Cascade)-like complex are needed for crRNA stability in the CRISPR-Cas type I-B system in Haloferax volcanii in vivo. Deletion of the cas6 gene results in the loss of mature crRNAs and interference. However, cells that have the complete cas gene cluster (cas1-8b) removed and are transformed with the cas6 gene are not able to produce and stably maintain mature crRNAs. crRNA production and stability is rescued only if cas5, -6, and -7 are present. Mutational analysis of the cas6 gene reveals three amino acids (His-41, Gly-256, and Gly-258) that are essential for pre-crRNA cleavage, whereas the mutation of two amino acids (Ser-115 and Ser-224) leads to an increase of crRNA amounts. This is the first systematic in vivo analysis of Cas6 protein variants. In addition, we show that the H. volcanii I-B system contains a Cascade-like complex with a Cas7, Cas5, and Cas6 core that protects the crRNA.

A Complex of Cas Proteins 5, 6, and 7 Is Required for the Biogenesis and Stability of Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-derived RNAs (crRNAs) in Haloferax volcanii*

PubMed Central

Brendel, Jutta; Stoll, Britta; Lange, Sita J.; Sharma, Kundan; Lenz, Christof; Stachler, Aris-Edda; Maier, Lisa-Katharina; Richter, Hagen; Nickel, Lisa; Schmitz, Ruth A.; Randau, Lennart; Allers, Thorsten; Urlaub, Henning; Backofen, Rolf; Marchfelder, Anita

2014-01-01

The clustered regularly interspaced short palindromic repeats/CRISPR-associated (CRISPR-Cas) system is a prokaryotic defense mechanism against foreign genetic elements. A plethora of CRISPR-Cas versions exist, with more than 40 different Cas protein families and several different molecular approaches to fight the invading DNA. One of the key players in the system is the CRISPR-derived RNA (crRNA), which directs the invader-degrading Cas protein complex to the invader. The CRISPR-Cas types I and III use the Cas6 protein to generate mature crRNAs. Here, we show that the Cas6 protein is necessary for crRNA production but that additional Cas proteins that form a CRISPR-associated complex for antiviral defense (Cascade)-like complex are needed for crRNA stability in the CRISPR-Cas type I-B system in Haloferax volcanii in vivo. Deletion of the cas6 gene results in the loss of mature crRNAs and interference. However, cells that have the complete cas gene cluster (cas1–8b) removed and are transformed with the cas6 gene are not able to produce and stably maintain mature crRNAs. crRNA production and stability is rescued only if cas5, -6, and -7 are present. Mutational analysis of the cas6 gene reveals three amino acids (His-41, Gly-256, and Gly-258) that are essential for pre-crRNA cleavage, whereas the mutation of two amino acids (Ser-115 and Ser-224) leads to an increase of crRNA amounts. This is the first systematic in vivo analysis of Cas6 protein variants. In addition, we show that the H. volcanii I-B system contains a Cascade-like complex with a Cas7, Cas5, and Cas6 core that protects the crRNA. PMID:24459147

Lack of production of (p)ppGpp in Halobacterium volcanii under conditions that are effective in the eubacteria.

PubMed Central

Scoarughi, G L; Cimmino, C; Donini, P

1995-01-01

The stringent halobacterial strain Haloferax volcanii was subjected to a set of physiological conditions different from amino acid starvation that are known to cause production of guanosine polyphosphates [(p)pp Gpp] in eubacteria via the relA-independent (spoT) pathway. The conditions used were temperature upshift, treatment with cyanide, and total starvation. Under none of these conditions were detectable levels of (p)ppGpp observed. This result, in conjunction with our previous finding that (p)ppGpp synthesis does not occur under amino acid starvation, leads to the conclusion that in halobacteria both growth rate control and stringency are probably governed by mechanisms that operate in the absence of ppGpp. During exponential growth, a low level of phosphorylated compounds with electrophoretic mobilities similar, but not identical, to that of (p)ppGpp were observed. The intracellular concentration of these compounds increased considerably during the stationary phase of growth and with all of the treatments used. The compounds were identified as short-chain polyphosphates identical to those found under similar conditions in Saccharomyces cerevisiae. PMID:7798153

LccA, an Archaeal Laccase Secreted as a Highly Stable Glycoprotein into the Extracellular Medium by Haloferax volcanii▿ †

PubMed Central

Uthandi, Sivakumar; Saad, Boutaiba; Humbard, Matthew A.; Maupin-Furlow, Julie A.

2010-01-01

Laccases couple the oxidation of phenolic compounds to the reduction of molecular oxygen and thus span a wide variety of applications. While laccases of eukaryotes and bacteria are well characterized, these enzymes have not been described in archaea. Here, we report the purification and characterization of a laccase (LccA) from the halophilic archaeon Haloferax volcanii. LccA was secreted at high levels into the culture supernatant of a recombinant H. volcanii strain, with peak activity (170 ± 10 mU·ml−1) at stationary phase (72 to 80 h). LccA was purified 13-fold to an overall yield of 72% and a specific activity of 29.4 U·mg−1 with an absorbance spectrum typical of blue multicopper oxidases. The mature LccA was processed to expose an N-terminal Ala after the removal of 31 amino acid residues and was glycosylated to 6.9% carbohydrate content. Purified LccA oxidized a variety of organic substrates, including bilirubin, syringaldazine (SGZ), 2,2,-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and dimethoxyphenol (DMP), with DMP oxidation requiring the addition of CuSO4. Optimal oxidation of ABTS and SGZ was at 45°C and pH 6 and pH 8.4, respectively. The apparent Km values for SGZ, bilirubin, and ABTS were 35, 236, and 670 μM, with corresponding kcat values of 22, 29, and 10 s−1, respectively. The purified LccA was tolerant of high salt, mixed organosolvents, and high temperatures, with a half-life of inactivation at 50°C of 31.5 h. PMID:19966030

Halophilic archaebacteria from the Kalamkass oil field

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

Zvyagintseva, I.S.; Belyaev, S.S.; Borzenkov, I.A.

1995-01-01

Two strains of halophilic archaebacteria, growing in a medium containing from 10 to 25% NaCl, were isolated from the brines of the Kalamkass (Mangyshlak) oil field. Both strains are extremely halophilic archaebacteria according to the complex of their phenotypic properties. Strain M-11 was identified as Haloferax mediterranei on the basis of the composition of polar lipids and DNA-DNA homology. The composition of polar lipids and 16S rRNA sequence of strain M-18 allowed us to assign it to the genus Haloferax. This strain differs from the approved species of the genus Haloferax, H. volcanii, and H. mediterranei. However, to describe itmore » as a new species, additional investigations are necessary. 13 refs., 3 figs.« less

Deletion of the Sm1 encoding motif in the lsm gene results in distinct changes in the transcriptome and enhanced swarming activity of Haloferax cells.

PubMed

Maier, Lisa-Katharina; Benz, Juliane; Fischer, Susan; Alstetter, Martina; Jaschinski, Katharina; Hilker, Rolf; Becker, Anke; Allers, Thorsten; Soppa, Jörg; Marchfelder, Anita

2015-10-01

Members of the Sm protein family are important for the cellular RNA metabolism in all three domains of life. The family includes archaeal and eukaryotic Lsm proteins, eukaryotic Sm proteins and archaeal and bacterial Hfq proteins. While several studies concerning the bacterial and eukaryotic family members have been published, little is known about the archaeal Lsm proteins. Although structures for several archaeal Lsm proteins have been solved already more than ten years ago, we still do not know much about their biological function, however one can confidently propose that the archaeal Lsm proteins will also be involved in RNA metabolism. Therefore, we investigated this protein in the halophilic archaeon Haloferax volcanii. The Haloferax genome encodes a single Lsm protein, the lsm gene overlaps and is co-transcribed with the gene for the ribosomal L37.eR protein. Here, we show that the reading frame of the lsm gene contains a promoter which regulates expression of the overlapping rpl37R gene. This rpl37R specific promoter ensures high expression of the rpl37R gene in exponential growth phase. To investigate the biological function of the Lsm protein we generated a lsm deletion mutant that had the coding sequence for the Sm1 motif removed but still contained the internal promoter for the downstream rpl37R gene. The transcriptome of this deletion mutant was compared to the wild type transcriptome, revealing that several genes are down-regulated and many genes are up-regulated in the deletion strain. Northern blot analyses confirmed down-regulation of two genes. In addition, the deletion strain showed a gain of function in swarming, in congruence with the up-regulation of transcripts encoding proteins required for motility. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Deciphering the Translation Initiation Factor 5A Modification Pathway in Halophilic Archaea

PubMed Central

Graf, Michael; Blaby, Ian K.; Makkay, Andrea M.; Starosta, Agata L.; Papke, R. Thane; Oshima, Tairo; Wilson, Daniel N.

2016-01-01

Translation initiation factor 5A (IF5A) is essential and highly conserved in Eukarya (eIF5A) and Archaea (aIF5A). The activity of IF5A requires hypusine, a posttranslational modification synthesized in Eukarya from the polyamine precursor spermidine. Intracellular polyamine analyses revealed that agmatine and cadaverine were the main polyamines produced in Haloferax volcanii in minimal medium, raising the question of how hypusine is synthesized in this halophilic Archaea. Metabolic reconstruction led to a tentative picture of polyamine metabolism and aIF5A modification in Hfx. volcanii that was experimentally tested. Analysis of aIF5A from Hfx. volcanii by LC-MS/MS revealed it was exclusively deoxyhypusinylated. Genetic studies confirmed the role of the predicted arginine decarboxylase gene (HVO_1958) in agmatine synthesis. The agmatinase-like gene (HVO_2299) was found to be essential, consistent with a role in aIF5A modification predicted by physical clustering evidence. Recombinant deoxyhypusine synthase (DHS) from S. cerevisiae was shown to transfer 4-aminobutyl moiety from spermidine to aIF5A from Hfx. volcanii in vitro. However, at least under conditions tested, this transfer was not observed with the Hfx. volcanii DHS. Furthermore, the growth of Hfx. volcanii was not inhibited by the classical DHS inhibitor GC7. We propose a model of deoxyhypusine synthesis in Hfx. volcanii that differs from the canonical eukaryotic pathway, paving the way for further studies. PMID:28053595

Drastic differences in glycosylation of related S-layer glycoproteins from moderate and extreme halophiles.

PubMed

Mengele, R; Sumper, M

1992-04-25

The outer surface of the moderate halophilic archaebacterium Haloferax volcanii (formerly named Halobacterium volcanii) is covered with a hexagonally packed surface (S) layer glycoprotein. The polypeptide (794 amino acid residues) contains 7 N-glycosylation sites. Four of these sites were isolated as glycopeptides and the structure of one of the corresponding saccharides was determined. Oligosaccharides consisting of beta-1,4-linked glucose residues are attached to the protein via the linkage unit asparaginyl-glucose. In the related glycoprotein from the extreme halophile Halobacterium halobium, the glucose residues are replaced by sulfated glucuronic acid residues, causing a drastic increase in surface charge density. This is discussed in terms of a recent model explaining the stability of halophilic proteins.

A simple laser-based device for simultaneous microbial culture and absorbance measurement

NASA Astrophysics Data System (ADS)

Abrevaya, X. C.; Cortón, E.; Areso, O.; Mauas, P. J. D.

2013-07-01

In this work we present a device specifically designed to study microbial growth with several applications related to environmental microbiology and other areas of research as astrobiology. The Automated Measuring and Cultivation device (AMC-d) enables semi-continuous absorbance measurements directly during cultivation. It can measure simultaneously up to 16 samples. Growth curves using low and fast growing microorganism were plotted, including Escherichia coli and Haloferax volcanii, a halophilic archaeon.

Post-translational Modification of Extremophilic Proteins: N-glycosylation in Archaea

DTIC Science & Technology

2014-12-02

Kaminski, Z. Guan, S. Yurist-Doutsch, J. Eichler. Two Distinct N-Glycosylation Pathways Process the Haloferax volcanii S-Layer Glycoprotein upon Changes...Promiscuity: AglB, the Archaeal Oligosaccharyltransferase, Can Process a Variety of Lipid-Linked Glycans, Applied and Environmental Microbiology, (11 2013...Archaea,  N-­‐linked   oligosaccharides  are   assembled  on  dolichol  phosphate  prior  to  transfer  of  the  glycan

Haloarchaeal Protein Translocation via the Twin Arginine Translocation Pathway

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

Pohlschroder Mechthild

2009-02-03

Protein transport across hydrophobic membranes that partition cellular compartments is essential in all cells. The twin arginine translocation (Tat) pathway transports proteins across the prokaryotic cytoplasmic membranes. Distinct from the universally conserved Sec pathway, which secretes unfolded proteins, the Tat machinery is unique in that it secretes proteins in a folded conformation, making it an attractive pathway for the transport and secretion of heterologously expressed proteins that are Sec-incompatible. During the past 7 years, the DOE-supported project has focused on the characterization of the diversity of bacterial and archaeal Tat substrates as well as on the characterization of the Tatmore » pathway of a model archaeon, Haloferax volcanii, a member of the haloarchaea. We have demonstrated that H. volcanii uses this pathway to transport most of its secretome.« less

Archaea-based microbial fuel cell operating at high ionic strength conditions.

PubMed

Abrevaya, Ximena C; Sacco, Natalia; Mauas, Pablo J D; Cortón, Eduardo

2011-11-01

In this work, two archaea microorganisms (Haloferax volcanii and Natrialba magadii) used as biocatalyst at a microbial fuel cell (MFC) anode were evaluated. Both archaea are able to grow at high salt concentrations. By increasing the media conductivity, the internal resistance was diminished, improving the MFC's performance. Without any added redox mediator, maximum power (P (max)) and current at P (max) were 11.87/4.57/0.12 μW cm(-2) and 49.67/22.03/0.59 μA cm(-2) for H. volcanii, N. magadii and E. coli, respectively. When neutral red was used as the redox mediator, P (max) was 50.98 and 5.39 μW cm(-2) for H. volcanii and N. magadii, respectively. In this paper, an archaea MFC is described and compared with other MFC systems; the high salt concentration assayed here, comparable with that used in Pt-catalyzed alkaline hydrogen fuel cells, will open new options when MFC scaling up is the objective necessary for practical applications.

Draft Genome Sequence of Haloferax sp. Strain ATB1, Isolated from a Semi-Arid Region in the Brazilian Caatinga.

PubMed

Castro, Wendel de Oliveira; Torres-Ballesteros, Adriana Maria; Nakayama, Cristina Rossi; Melo, Itamar Soares; Pellizari, Vivian Helena; Silva, Artur; Ramos, Rommel Thiago Jucá

2014-08-14

Organisms in the Haloferax genus are extreme halophiles that grow in environments with pH values between 4 and 12, and temperatures between 0°C and 60°C. In the present study, a draft of the first Haloferax sp. strain ATB1 genome isolated from the region of Cariri (in Paraíba State, Brazil) is presented. Copyright © 2014 Castro et al.

Ribosome surface properties may impose limits on the nature of the cytoplasmic proteome

PubMed Central

2017-01-01

Much of the molecular motion in the cytoplasm is diffusive, which possibly limits the tempo of processes. We studied the dependence of protein mobility on protein surface properties and ionic strength. We used surface-modified fluorescent proteins (FPs) and determined their translational diffusion coefficients (D) in the cytoplasm of Escherichia coli, Lactococcus lactis and Haloferax volcanii. We find that in E. coli D depends on the net charge and its distribution over the protein, with positive proteins diffusing up to 100-fold slower than negative ones. This effect is weaker in L. lactis and Hfx. volcanii due to electrostatic screening. The decrease in mobility is probably caused by interaction of positive FPs with ribosomes as shown in in vivo diffusion measurements and confirmed in vitro with purified ribosomes. Ribosome surface properties may thus limit the composition of the cytoplasmic proteome. This finding lays bare a paradox in the functioning of prokaryotic (endo)symbionts. PMID:29154755

Transcription-coupled repair of UV damage in the halophilic archaea.

PubMed

Stantial, Nicole; Dumpe, Jarrod; Pietrosimone, Kathryn; Baltazar, Felicia; Crowley, David J

2016-05-01

Transcription-coupled repair (TCR) is a subpathway of nucleotide excision repair (NER) in which excision repair proteins are targeted to RNA polymerase-arresting lesions located in the transcribed strand of active genes. TCR has been documented in a variety of bacterial and eukaryotic organisms but has yet to be observed in the Archaea. We used Halobacterium sp. NRC-1 and Haloferax volcanii to determine if TCR occurs in the halophilic archaea. Following UV irradiation of exponentially growing cultures, we quantified the rate of repair of cyclobutane pyrimidine dimers in the two strands of the rpoB2B1A1A2 and the trpDFEG operons of Halobacterium sp. NRC-1 and the pts operon of H. volcanii through the use of a Southern blot assay and strand-specific probes. TCR was observed in all three operons and was dependent on the NER gene uvrA in Halobacterium sp. NRC-1, but not in H. volcanii. The halophilic archaea likely employ a novel mechanism for TCR in which an as yet unknown coupling factor recognizes the arrested archaeal RNA polymerase complex and recruits certain NER proteins to complete the process. Copyright © 2016 Elsevier B.V. All rights reserved.

An Archaeal Immune System Can Detect Multiple Protospacer Adjacent Motifs (PAMs) to Target Invader DNA*

PubMed Central

Fischer, Susan; Maier, Lisa-Katharina; Stoll, Britta; Brendel, Jutta; Fischer, Eike; Pfeiffer, Friedhelm; Dyall-Smith, Mike; Marchfelder, Anita

2012-01-01

The clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated (Cas) system provides adaptive and heritable immunity against foreign genetic elements in most archaea and many bacteria. Although this system is widespread and diverse with many subtypes, only a few species have been investigated to elucidate the precise mechanisms for the defense of viruses or plasmids. Approximately 90% of all sequenced archaea encode CRISPR/Cas systems, but their molecular details have so far only been examined in three archaeal species: Sulfolobus solfataricus, Sulfolobus islandicus, and Pyrococcus furiosus. Here, we analyzed the CRISPR/Cas system of Haloferax volcanii using a plasmid-based invader assay. Haloferax encodes a type I-B CRISPR/Cas system with eight Cas proteins and three CRISPR loci for which the identity of protospacer adjacent motifs (PAMs) was unknown until now. We identified six different PAM sequences that are required upstream of the protospacer to permit target DNA recognition. This is only the second archaeon for which PAM sequences have been determined, and the first CRISPR group with such a high number of PAM sequences. Cells could survive the plasmid challenge if their CRISPR/Cas system was altered or defective, e.g. by deletion of the cas gene cassette. Experimental PAM data were supplemented with bioinformatics data on Haloferax and Haloquadratum. PMID:22767603

FtsZ ring: the eubacterial division apparatus conserved in archaebacteria.

PubMed

Wang, X; Lutkenhaus, J

1996-07-01

FtsZ is a tubulin-like protein that is essential for cell division in eubacteria. It functions by forming a ring at the division site that directs septation. The archaebacteria constitute a kingdom of life separate from eubacteria and eukaryotes. Like eubacteria, archaebacteria are prokaryotes, although they are phylogenetically closer to eukaryotes. Here it is shown that archaebacteria also possess FtsZ and that it is biochemically similar to eubacterial FtsZs. Significantly, FtsZ from the archaebacterium Haloferax volcanii is a GTPase that is localized to a ring that coincides with the division constriction. These results indicate that the FtsZ ring was part of the division apparatus of a common prokaryotic ancestor that was retained by both eubacteria and archaebacteria.

The haloarchaeal MCM proteins: bioinformatic analysis and targeted mutagenesis of the β7-β8 and β9-β10 hairpin loops and conserved zinc binding domain cysteines.

PubMed

Kristensen, Tatjana P; Maria Cherian, Reeja; Gray, Fiona C; MacNeill, Stuart A

2014-01-01

The hexameric MCM complex is the catalytic core of the replicative helicase in eukaryotic and archaeal cells. Here we describe the first in vivo analysis of archaeal MCM protein structure and function relationships using the genetically tractable haloarchaeon Haloferax volcanii as a model system. Hfx. volcanii encodes a single MCM protein that is part of the previously identified core group of haloarchaeal MCM proteins. Three structural features of the N-terminal domain of the Hfx. volcanii MCM protein were targeted for mutagenesis: the β7-β8 and β9-β10 β-hairpin loops and putative zinc binding domain. Five strains carrying single point mutations in the β7-β8 β-hairpin loop were constructed, none of which displayed impaired cell growth under normal conditions or when treated with the DNA damaging agent mitomycin C. However, short sequence deletions within the β7-β8 β-hairpin were not tolerated and neither was replacement of the highly conserved residue glutamate 187 with alanine. Six strains carrying paired alanine substitutions within the β9-β10 β-hairpin loop were constructed, leading to the conclusion that no individual amino acid within that hairpin loop is absolutely required for MCM function, although one of the mutant strains displays greatly enhanced sensitivity to mitomycin C. Deletions of two or four amino acids from the β9-β10 β-hairpin were tolerated but mutants carrying larger deletions were inviable. Similarly, it was not possible to construct mutants in which any of the conserved zinc binding cysteines was replaced with alanine, underlining the likely importance of zinc binding for MCM function. The results of these studies demonstrate the feasibility of using Hfx. volcanii as a model system for reverse genetic analysis of archaeal MCM protein function and provide important confirmation of the in vivo importance of conserved structural features identified by previous bioinformatic, biochemical and structural studies.

The haloarchaeal MCM proteins: bioinformatic analysis and targeted mutagenesis of the β7-β8 and β9-β10 hairpin loops and conserved zinc binding domain cysteines

PubMed Central

Kristensen, Tatjana P.; Maria Cherian, Reeja; Gray, Fiona C.; MacNeill, Stuart A.

2014-01-01

The hexameric MCM complex is the catalytic core of the replicative helicase in eukaryotic and archaeal cells. Here we describe the first in vivo analysis of archaeal MCM protein structure and function relationships using the genetically tractable haloarchaeon Haloferax volcanii as a model system. Hfx. volcanii encodes a single MCM protein that is part of the previously identified core group of haloarchaeal MCM proteins. Three structural features of the N-terminal domain of the Hfx. volcanii MCM protein were targeted for mutagenesis: the β7-β8 and β9-β10 β-hairpin loops and putative zinc binding domain. Five strains carrying single point mutations in the β7-β8 β-hairpin loop were constructed, none of which displayed impaired cell growth under normal conditions or when treated with the DNA damaging agent mitomycin C. However, short sequence deletions within the β7-β8 β-hairpin were not tolerated and neither was replacement of the highly conserved residue glutamate 187 with alanine. Six strains carrying paired alanine substitutions within the β9-β10 β-hairpin loop were constructed, leading to the conclusion that no individual amino acid within that hairpin loop is absolutely required for MCM function, although one of the mutant strains displays greatly enhanced sensitivity to mitomycin C. Deletions of two or four amino acids from the β9-β10 β-hairpin were tolerated but mutants carrying larger deletions were inviable. Similarly, it was not possible to construct mutants in which any of the conserved zinc binding cysteines was replaced with alanine, underlining the likely importance of zinc binding for MCM function. The results of these studies demonstrate the feasibility of using Hfx. volcanii as a model system for reverse genetic analysis of archaeal MCM protein function and provide important confirmation of the in vivo importance of conserved structural features identified by previous bioinformatic, biochemical and structural studies. PMID:24723920

Taxonomic analysis of extremely halophilic archaea isolated from 56-years-old dead sea brine samples.

PubMed

Arahal, D R; Gutiérrez, M C; Volcani, B E; Ventosa, A

2000-10-01

A taxonomic study comprising both phenotypic and genotypic characterization, has been carried out on a total of 158 extremely halophilic aerobic archaeal strains. These strains were isolated from enrichments prepared from Dead Sea water samples dating from 1936 that were collected by B. E. Volcani for the demonstration of microbial life in the Dead Sea. The isolates were examined for 126 morphological, physiological, biochemical and nutritional tests. Numerical analysis of the data, by using the S(J) coefficient and UPGMA clustering method, showed that the isolates clustered into six phenons. Twenty-two out of the 158 strains used in this study were characterized previously (ARAHAL et al., 1996) and were placed into five phenotypic groups. The genotypic study included both the determination of the guanineplus-cytosine content of the DNA and DNA-DNA hybridization studies. For this purpose, representative strains from the six phenons were chosen. These groups were found to represent some members of three different genera - Haloarcula (phenons A, B, and C), Haloferax (phenons D and E) and Halobacterium (phenon F) - of the family Halobacteriaceae, some of them never reported to occur in the Dead Sea, such as Haloarcula hispanica, while Haloferax volcanii (phenons D and E) was described in the Dead Sea by studies carried out several decades later than Volcani's work.

Purification and properties of a dissimilatory nitrate reductase from Haloferax denitrificans

NASA Technical Reports Server (NTRS)

Hochstein, L. I.; Lang, F.

1991-01-01

A membrane-bound nitrate reductase (nitrite:(acceptor) oxidoreductase, EC 1.7.99.4) from the extremely halophilic bacterium Haloferax denitrificans was solubilized by incubating membranes in buffer lacking NaCl and purified by DEAE, hydroxylapatite, and Sepharose 6B gel filtration chromatography. The purified nitrate reductase reduced chlorate and was inhibited by azide and cyanide. Preincubating the enzyme with cyanide increased the extent of inhibition which in turn was intensified when dithionite was present. Although cyanide was a noncompetitive inhibitor with respect to nitrate, nitrate protected against inhibition. The enzyme, as isolated, was composed of two subunits (Mr 116,000 and 60,000) and behaved as a dimer during gel filtration (Mr 380,000). Unlike other halobacterial enzymes, this nitrate reductase was most active, as well as stable, in the absence of salt.

Draft genome sequence of a human-associated isolate of Haloferax alexandrinus strain Arc-hr, an extremely halophilic archaea.

PubMed

Khelaifia, S; Caputo, A; Djossou, F; Raoult, D

2017-01-01

We report the draft genome sequence of Haloferax alexandrinus strain Arc-hr (CSUR P798), isolated from the human gut of a 10-year-old Amazonian individual. Its 3 893 626 bp genome exhibits a 66.00% GC content. The genome of the strain Arc-hr contains 37 genes identified as ORFans, seven genes associated to halocin and 11 genes associated with polyketide synthases or nonribosomal peptide synthetases.

Construction of a Specialized Cloning Strain of E. Coli for the Nitrate Reductase Genes of Haloferax Denitrificans

NASA Technical Reports Server (NTRS)

Johnson, Emmett

1999-01-01

This is the final report on Joint Research Interchange (NCC2-5011) "Construction of a Specialized Cloning Strain of E.. coli for the Nitrate Reductase Genes of Haloferax denitrificans." Originally the award was 11/l/93-10/31/95, but there were no-cost extensions made, because of a year Sabbatical at the Pasteur Institute in Paris and other leaves of 3 months each at the Pasteur Institute, during which work could not be done on this project, which extended the closing date to 10/30/98.

Archaeal Tuc1/Ncs6 Homolog Required for Wobble Uridine tRNA Thiolation Is Associated with Ubiquitin-Proteasome, Translation, and RNA Processing System Homologs

PubMed Central

Chavarria, Nikita E.; Hwang, Sungmin; Cao, Shiyun; Fu, Xian; Holman, Mary; Elbanna, Dina; Rodriguez, Suzanne; Arrington, Deanna; Englert, Markus; Uthandi, Sivakumar; Söll, Dieter; Maupin-Furlow, Julie A.

2014-01-01

While cytoplasmic tRNA 2-thiolation protein 1 (Tuc1/Ncs6) and ubiquitin-related modifier-1 (Urm1) are important in the 2-thiolation of 5-methoxycarbonylmethyl-2-thiouridine (mcm5s2U) at wobble uridines of tRNAs in eukaryotes, the biocatalytic roles and properties of Ncs6/Tuc1 and its homologs are poorly understood. Here we present the first report of an Ncs6 homolog of archaea (NcsA of Haloferax volcanii) that is essential for maintaining cellular pools of thiolated tRNALys UUU and for growth at high temperature. When purified from Hfx. volcanii, NcsA was found to be modified at Lys204 by isopeptide linkage to polymeric chains of the ubiquitin-fold protein SAMP2. The ubiquitin-activating E1 enzyme homolog of archaea (UbaA) was required for this covalent modification. Non-covalent protein partners that specifically associated with NcsA were also identified including UbaA, SAMP2, proteasome activating nucleotidase (PAN)-A/1, translation elongation factor aEF-1α and a β-CASP ribonuclease homolog of the archaeal cleavage and polyadenylation specificity factor 1 family (aCPSF1). Together, our study reveals that NcsA is essential for growth at high temperature, required for formation of thiolated tRNALys UUU and intimately linked to homologs of ubiquitin-proteasome, translation and RNA processing systems. PMID:24906001

Archaeal Tuc1/Ncs6 homolog required for wobble uridine tRNA thiolation is associated with ubiquitin-proteasome, translation, and RNA processing system homologs.

PubMed

Chavarria, Nikita E; Hwang, Sungmin; Cao, Shiyun; Fu, Xian; Holman, Mary; Elbanna, Dina; Rodriguez, Suzanne; Arrington, Deanna; Englert, Markus; Uthandi, Sivakumar; Söll, Dieter; Maupin-Furlow, Julie A

2014-01-01

While cytoplasmic tRNA 2-thiolation protein 1 (Tuc1/Ncs6) and ubiquitin-related modifier-1 (Urm1) are important in the 2-thiolation of 5-methoxycarbonylmethyl-2-thiouridine (mcm5s2U) at wobble uridines of tRNAs in eukaryotes, the biocatalytic roles and properties of Ncs6/Tuc1 and its homologs are poorly understood. Here we present the first report of an Ncs6 homolog of archaea (NcsA of Haloferax volcanii) that is essential for maintaining cellular pools of thiolated tRNA(Lys)UUU and for growth at high temperature. When purified from Hfx. volcanii, NcsA was found to be modified at Lys204 by isopeptide linkage to polymeric chains of the ubiquitin-fold protein SAMP2. The ubiquitin-activating E1 enzyme homolog of archaea (UbaA) was required for this covalent modification. Non-covalent protein partners that specifically associated with NcsA were also identified including UbaA, SAMP2, proteasome activating nucleotidase (PAN)-A/1, translation elongation factor aEF-1α and a β-CASP ribonuclease homolog of the archaeal cleavage and polyadenylation specificity factor 1 family (aCPSF1). Together, our study reveals that NcsA is essential for growth at high temperature, required for formation of thiolated tRNA(Lys)UUU and intimately linked to homologs of ubiquitin-proteasome, translation and RNA processing systems.

Divergent Roles of RPA Homologs of the Model Archaeon Halobacterium salinarum in Survival of DNA Damage.

PubMed

Evans, Jessica J; Gygli, Patrick E; McCaskill, Julienne; DeVeaux, Linda C

2018-04-20

The haloarchaea are unusual in possessing genes for multiple homologs to the ubiquitous single-stranded DNA binding protein (SSB or replication protein A, RPA) found in all three domains of life. Halobacterium salinarum contains five homologs: two are eukaryotic in organization, two are prokaryotic and are encoded on the minichromosomes, and one is uniquely euryarchaeal. Radiation-resistant mutants previously isolated show upregulation of one of the eukaryotic-type RPA genes. Here, we have created deletions in the five RPA operons. These deletion mutants were exposed to DNA-damaging conditions: ionizing radiation, UV radiation, and mitomycin C. Deletion of the euryarchaeal homolog, although not lethal as in Haloferax volcanii , causes severe sensitivity to all of these agents. Deletion of the other RPA/SSB homologs imparts a variable sensitivity to these DNA-damaging agents, suggesting that the different RPA homologs have specialized roles depending on the type of genomic insult encountered.

Enoyl-CoA hydratase mediates polyhydroxyalkanoate mobilization in Haloferax mediterranei

PubMed Central

Liu, Guiming; Cai, Shuangfeng; Hou, Jing; Zhao, Dahe; Han, Jing; Zhou, Jian; Xiang, Hua

2016-01-01

Although polyhydroxyalkanoate (PHA) accumulation and mobilization are one of the most general mechanisms for haloarchaea to adapt to the hypersaline environments with changeable carbon sources, the PHA mobilization pathways are still not clear for any haloarchaea. In this study, the functions of five putative (R)-specific enoyl-CoA hydratases (R-ECHs) in Haloferax mediterranei, named PhaJ1 to PhaJ5, respectively, were thoroughly investigated. Through gene deletion and complementation, we demonstrated that only certain of these ECHs had a slight contribution to poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) biosynthesis. But significantly, PhaJ1, the only R-ECH that is associated with PHA granules, was shown to be involved in PHA mobilization in this haloarchaeon. PhaJ1 catalyzes the dehydration of (R)-3-hydroxyacyl-CoA, the common product of PHA degradation, to enoyl-CoA, the intermediate of the β-oxidation cycle, thus could link PHA mobilization to β-oxidation pathway in H. mediterranei. This linkage was further indicated from the up-regulation of the key genes of β-oxidation under the PHA mobilization condition, as well as the obvious inhibition of PHA degradation upon inhibition of the β-oxidation pathway. Interestingly, 96% of phaJ-containing haloarchaeal species possess both phaC (encoding PHA synthase) and the full set genes of β-oxidation, implying that the mobilization of carbon storage in PHA through the β-oxidation cycle would be general in haloarchaea. PMID:27052994

Enoyl-CoA hydratase mediates polyhydroxyalkanoate mobilization in Haloferax mediterranei.

PubMed

Liu, Guiming; Cai, Shuangfeng; Hou, Jing; Zhao, Dahe; Han, Jing; Zhou, Jian; Xiang, Hua

2016-04-07

Although polyhydroxyalkanoate (PHA) accumulation and mobilization are one of the most general mechanisms for haloarchaea to adapt to the hypersaline environments with changeable carbon sources, the PHA mobilization pathways are still not clear for any haloarchaea. In this study, the functions of five putative (R)-specific enoyl-CoA hydratases (R-ECHs) in Haloferax mediterranei, named PhaJ1 to PhaJ5, respectively, were thoroughly investigated. Through gene deletion and complementation, we demonstrated that only certain of these ECHs had a slight contribution to poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) biosynthesis. But significantly, PhaJ1, the only R-ECH that is associated with PHA granules, was shown to be involved in PHA mobilization in this haloarchaeon. PhaJ1 catalyzes the dehydration of (R)-3-hydroxyacyl-CoA, the common product of PHA degradation, to enoyl-CoA, the intermediate of the β-oxidation cycle, thus could link PHA mobilization to β-oxidation pathway in H. mediterranei. This linkage was further indicated from the up-regulation of the key genes of β-oxidation under the PHA mobilization condition, as well as the obvious inhibition of PHA degradation upon inhibition of the β-oxidation pathway. Interestingly, 96% of phaJ-containing haloarchaeal species possess both phaC (encoding PHA synthase) and the full set genes of β-oxidation, implying that the mobilization of carbon storage in PHA through the β-oxidation cycle would be general in haloarchaea.

The role of Cas8 in type I CRISPR interference.

PubMed

Cass, Simon D B; Haas, Karina A; Stoll, Britta; Alkhnbashi, Omer S; Sharma, Kundan; Urlaub, Henning; Backofen, Rolf; Marchfelder, Anita; Bolt, Edward L

2015-05-05

CRISPR (clustered regularly interspaced short palindromic repeat) systems provide bacteria and archaea with adaptive immunity to repel invasive genetic elements. Type I systems use 'cascade' [CRISPR-associated (Cas) complex for antiviral defence] ribonucleoprotein complexes to target invader DNA, by base pairing CRISPR RNA (crRNA) to protospacers. Cascade identifies PAMs (protospacer adjacent motifs) on invader DNA, triggering R-loop formation and subsequent DNA degradation by Cas3. Cas8 is a candidate PAM recognition factor in some cascades. We analysed Cas8 homologues from type IB CRISPR systems in archaea Haloferax volcanii (Hvo) and Methanothermobacter thermautotrophicus (Mth). Cas8 was essential for CRISPR interference in Hvo and purified Mth Cas8 protein responded to PAM sequence when binding to nucleic acids. Cas8 interacted physically with Cas5-Cas7-crRNA complex, stimulating binding to PAM containing substrates. Mutation of conserved Cas8 amino acid residues abolished interference in vivo and altered catalytic activity of Cas8 protein in vitro. This is experimental evidence that Cas8 is important for targeting Cascade to invader DNA. © 2015 Authors.

Engineering substrate promiscuity in halophilic alcohol dehydrogenase (HvADH2) by in silico design.

PubMed

Cassidy, Jennifer; Bruen, Larah; Rosini, Elena; Molla, Gianluca; Pollegioni, Loredano; Paradisi, Francesca

2017-01-01

An alcohol dehydrogenase from the halophilic archaeon Haloferax volcanii (HvADH2) has been engineered by rational design to broaden its substrate scope towards the conversion of a range of aromatic substrates, including flurbiprofenol, that is an intermediate of the non-steroidal anti-inflammatory drug, flurbiprofen. Wild-type HvADH2 showed minimal activity with flurbiprofenol (11.1 mU/mg). A homology model of HvADH2 was built and docking experiments with this substrate revealed that the biphenyl rings of flurbiprofenol formed strong interactions with residues F85 and F108, preventing its optimal binding in the active site. Mutations at position 85 however did not increase activity. Site directed mutagenesis at position F108 allowed the identification of three variants showing a significant (up to 2.3-fold) enhancement of activity towards flurbiprofenol, when compared to wild-type HvADH2. Interestingly, F108G variant did not show the classic inhibition in the presence of (R)-enantiomer when tested with rac-1-phenylethanol, underling its potential in racemic resolution of secondary alcohols.

Prospects for robust biocatalysis: engineering of novel specificity in a halophilic amino acid dehydrogenase.

PubMed

Munawar, Nayla; Engel, Paul C

2013-01-01

Heat- and solvent-tolerant enzymes from halophiles, potentially important industrially, offer a robust framework for protein engineering, but few solved halophilic structures exist to guide this. Homology modelling has guided mutations in glutamate dehydrogenase (GDH) from Halobacterium salinarum to emulate conversion of a mesophilic GDH to a methionine dehydrogenase. Replacement of K89, A163 and S367 by leucine, glycine and alanine converted halophilic GDH into a dehydrogenase accepting L-methionine, L-norleucine and L-norvaline as substrates. Over-expression in the halophilic expression host Haloferax volcanii and three-step purification gave ~98 % pure protein exhibiting maximum activity at pH 10. This enzyme also showed enhanced thermostability and organic solvent tolerance even at 70 °C, offering a biocatalyst resistant to harsh industrial environments. To our knowledge, this is the first reported amino acid specificity change engineered in a halophilic enzyme, encouraging use of mesophilic models to guide engineering of novel halophilic biocatalysts for industrial application. Calibrated gel filtration experiments show that both the mutant and the wild-type enzyme are stable hexamers.

Microbial weeds in hypersaline habitats: the enigma of the weed-like Haloferax mediterranei.

PubMed

Oren, Aharon; Hallsworth, John E

2014-10-01

Heterotrophic prokaryotic communities that inhabit saltern crystallizer ponds are typically dominated by two species, the archaeon Haloquadratum walsbyi and the bacterium Salinibacter ruber, regardless of location. These organisms behave as 'microbial weeds' as defined by Cray et al. (Microb Biotechnol 6: 453-492, 2013) that possess the biological traits required to dominate the microbiology of these open habitats. Here, we discuss the enigma of the less abundant Haloferax mediterranei, an archaeon that grows faster than any other, comparable extreme halophile. It has a wide window for salt tolerance, can grow on simple as well as on complex substrates and degrade polymeric substances, has different modes of anaerobic growth, can accumulate storage polymers, produces gas vesicles, and excretes halocins capable of killing other Archaea. Therefore, Hfx. mediterranei is apparently more qualified as a 'microbial weed' than Haloquadratum and Salinibacter. However, the former differs because it produces carotenoid pigments only in the lower salinity range and lacks energy-generating retinal-based, light-driven ion pumps such as bacteriorhodopsin and halorhodopsin. We discuss these observations in relation to microbial weed biology in, and the open-habitat ecology of, hypersaline systems. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Extreme halophilic alcohol dehydrogenase mediated highly efficient syntheses of enantiopure aromatic alcohols.

PubMed

Alsafadi, Diya; Alsalman, Safaa; Paradisi, Francesca

2017-11-07

Enzymatic synthesis of enantiopure aromatic secondary alcohols (including substituted, hetero-aromatic and bicyclic structures) was carried out using halophilic alcohol dehydrogenase ADH2 from Haloferax volcanii (HvADH2). This enzyme showed an unprecedented substrate scope and absolute enatioselectivity. The cofactor NADPH was used catalytically and regenerated in situ by the biocatalyst, in the presence of 5% ethanol. The efficiency of HvADH2 for the conversion of aromatic ketones was markedly influenced by the steric and electronic factors as well as the solubility of ketones in the reaction medium. Furthermore, carbonyl stretching band frequencies ν (C[double bond, length as m-dash]O) have been measured for different ketones to understand the effect of electron withdrawing or donating properties of the ketone substituents on the reaction rate catalyzed by HvADH2. Good correlation was observed between ν (C[double bond, length as m-dash]O) of methyl aryl-ketones and the reaction rate catalyzed by HvADH2. The enzyme catalyzed the reductions of ketone substrates on the preparative scale, demonstrating that HvADH2 would be a valuable biocatalyst for the preparation of chiral aromatic alcohols of pharmaceutical interest.

In Vitro Antioxidant, Antihemolytic, and Anticancer Activity of the Carotenoids from Halophilic Archaea.

PubMed

Hou, Jing; Cui, Heng-Lin

2018-03-01

Halophilic archaea represent a promising natural source of carotenoids. However, little information is available about the biological effects of carotenoids from halophilic archaea. In this study, the carotenoids produced by seven halophilic archaeal strains Halogeometricum rufum, Halogeometricum limi, Haladaptatus litoreus, Haloplanus vescus, Halopelagius inordinatus, Halogranum rubrum, and Haloferax volcanii were identified by ultraviolet/visible spectroscopy, thin-layer chromatography, and high-performance liquid chromatography-tandem mass spectrometry. The C 50 carotenoids bacterioruberin and its derivatives monoanhydrobacterioruberin and bisanhydrobacterioruberin were found to be the predominant carotenoids. The antioxidant capacities of the carotenoids from these strains were significantly higher than β-carotene as determined by 1,1-diphenyl-2-picrylhydrazyl radical scavenging assay. The antihemolytic activities of these carotenoid extracts against H 2 O 2 -induced hemolysis in mouse erythrocytes were 3.9-6.3 times higher than β-carotene. A dose-dependent in vitro antiproliferative activity against HepG2 cells was observed for the extract from Hgm. limi, while that from Hpn. vescus exhibited a relatively high activity in a dose-independent manner. These results suggested that halophilic archaea could be considered as an alternative source of natural carotenoids with high antioxidant, antihemolytic, and anticancer activity.

Crystallization and preliminary X-ray analysis of binary and ternary complexes of Haloferax mediterranei glucose dehydrogenase

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

Esclapez, Julia; Britton, K. Linda; Baker, Patrick J.

2005-08-01

Single crystals of binary and ternary complexes of wild-type and D38C mutant H. mediterranei glucose dehydrogenase have been obtained by the hanging-drop vapour-diffusion method. Haloferax mediterranei glucose dehydrogenase (EC 1.1.1.47) belongs to the medium-chain alcohol dehydrogenase superfamily and requires zinc for catalysis. In the majority of these family members, the catalytic zinc is tetrahedrally coordinated by the side chains of a cysteine, a histidine, a cysteine or glutamate and a water molecule. In H. mediterranei glucose dehydrogenase, sequence analysis indicates that the zinc coordination is different, with the invariant cysteine replaced by an aspartate residue. In order to analyse themore » significance of this replacement and to contribute to an understanding of the role of the metal ion in catalysis, a range of binary and ternary complexes of the wild-type and a D38C mutant protein have been crystallized. For most of the complexes, crystals belonging to space group I222 were obtained using sodium/potassium citrate as a precipitant. However, for the binary and non-productive ternary complexes with NADPH/Zn, it was necessary to replace the citrate with 2-methyl-2,4-pentanediol. Despite the radical change in conditions, the crystals thus formed were isomorphous.« less

Structure and regulation of an archaebacterial promoter: An in vivo study. Progress report, August 1, 1991--March 31, 1993

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

Daniels, C.J.

1993-06-01

We have established that a 100 bp DNA fragment from the Haloferax volcanii tRNALys gene directs transcription in vivo. This element served as the starting point for a detailed analysis of the requirements for in vivo transcription. Among several gene tentatively identified as reporter elements, we selected a eukaryotic intron-containing tRNAPro gene for when it is driven by the H. volcanii tRNALys promoter fragment, produces a single small transcript. Transcript analysis, by Sl mapping and primer extension, showed that this RNA initiated at the expected tRNALys BoxB sequence and terminated in the tRNAPro RNA Pol III termination element present onmore » the DNA fragment. In initial studies we determined that the 3 inches proximal region of this tRNALys promoter element was sufficient for transcription initiation in vivo. This 40 bp region contains only the BoxA and BoxB regions and short purine rich regions 5 inches to the BoxA and BoxB sequence. Using the tRNAPro gene as the reporter and this minimal promoter, we performed a comprehensive analysis of the BoxA region. Each position of the BoxA region was converted to an four possible nucleotides and the transcription of 36 mutants was quantitated. Among the sites analyzed, only five of the positions showed high levels of discrimination; the preferred BoxA element was 5 inches-TT({sub T}/A)({sup A}/T) ANNNN-3 inches. Mutational analysis demonstrated that a transition from T-rich to A-rich sequences in the BoxA element is essential and that there is some flexibility in the location of the ``TA`` sequence. Additionally the TA sequence appears to determine the location of the transcription start site. The BoxA element defined in this study is similar to those observed for Sulfolobus and the methanogen promoters, and supports the hypothesis that a similar core promoter element is used by all archaeal RNA polymerases.« less

Chaperones and protein folding in the archaea.

PubMed

Large, Andrew T; Goldberg, Martin D; Lund, Peter A

2009-02-01

A survey of archaeal genomes for the presence of homologues of bacterial and eukaryotic chaperones reveals several interesting features. All archaea contain chaperonins, also known as Hsp60s (where Hsp is heat-shock protein). These are more similar to the type II chaperonins found in the eukaryotic cytosol than to the type I chaperonins found in bacteria, mitochondria and chloroplasts, although some archaea also contain type I chaperonin homologues, presumably acquired by horizontal gene transfer. Most archaea contain several genes for these proteins. Our studies on the type II chaperonins of the genetically tractable archaeon Haloferax volcanii have shown that only one of the three genes has to be present for the organisms to grow, but that there is some evidence for functional specialization between the different chaperonin proteins. All archaea also possess genes for prefoldin proteins and for small heat-shock proteins, but they generally lack genes for Hsp90 and Hsp100 homologues. Genes for Hsp70 (DnaK) and Hsp40 (DnaJ) homologues are only found in a subset of archaea. Thus chaperone-assisted protein folding in archaea is likely to display some unique features when compared with that in eukaryotes and bacteria, and there may be important differences in the process between euryarchaea and crenarchaea.

Halocin C8: an antimicrobial peptide distributed among four halophilic archaeal genera: Natrinema, Haloterrigena, Haloferax, and Halobacterium.

PubMed

Besse, Alison; Vandervennet, Manon; Goulard, Christophe; Peduzzi, Jean; Isaac, Stéphanie; Rebuffat, Sylvie; Carré-Mlouka, Alyssa

2017-05-01

Halophilic archaea thrive in hypersaline ecosystems and produce antimicrobial peptides (AMPs) named halocins. AMPs are essential effectors of microbial interactions in natural ecosystems. Halocin C8 is a 7.4 kDa peptide produced by Natrinema sp. AS7092. Surrounded by genes involved in regulation and transport, the halC8 gene encodes a precursor, processed into the mature halocin and an immunity protein, protecting the producing strain against its halocin. This feature constitutes a unique property of halocin C8, as known AMPs and their immunity proteins are generally encoded on distinct ORFs in an operon. By complementary in silico and PCR-based approaches, the presence of halC8 in halophilic archaea collected from various parts of the world was evidenced. The full-length halC8 gene is restricted and consistently found in the genomes of strains belonging to the phylogenetically related genera Natrinema and Haloterrigena, along with transport and regulation genes. Functional expression of halC8 was demonstrated by RT-PCR and antimicrobial assays. Active halocin C8 was shown to contain five disulphide bridges, presumably conferring a compact structure resistant to harsh environmental conditions. In other archaeal genera, Haloferax and Halobacterium, genes encoding halocin C8 with diverging immunity protein moiety were evidenced. A phylogenetic analysis of halocin C8 sequences was conducted.

Activity-guided separation and characterization of new halocin HA3 from fermented broth of Haloferax larsenii HA3.

PubMed

Kumar, Vijay; Tiwari, Santosh Kumar

2017-05-01

Haloferax larsenii HA3 was able to grow optimally in HS medium containing 15% NaCl, at pH 7.2 and 42 °C in aerobic conditions. Strain HA3 was found to be round shape, Gram-negative, catalase-positive, sensitive to bile acid, and resistant to chloramphenicol, and could not utilize arginine. The lipid profile revealed the presence of glycerol diether moiety (GDEM) suggesting Haloarchaea characteristics. Phylogenetic analysis based on 16S rRNA gene sequence similarities showed that it was closely related to H. larsenii ZJ206. Interestingly, strain HA3 was found to produce halocin HA3 which was purified using ultrafiltration and chromatography. It was found to be stable up to 80 °C, pH 2.0-10.0, organic solvents, surfactants, and detergents tested. However, the activity of halocin HA3 was completely reduced in the presence of proteinase K and trypsin. It was found to be halocidal against H. larsenii HA10, rupturing cell boundary and leading to cell death. The molecular weight of halocin HA3 was found to be ~13 kDa and MALDI-TOF MS/MS analysis suggested no homology with known halocins. The N-terminal ten amino-acid residues, NH 2 MNLGIILETN-COOH, suggested a new/novel halocin. These properties of halocin HA3 may be applicable for control of Haloarchaea in environments and salted foods.

Gene Repression in Haloarchaea Using the CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats)-Cas I-B System.

PubMed

Stachler, Aris-Edda; Marchfelder, Anita

2016-07-15

The clustered regularly interspaced short palindromic repeats (CRISPR)-Cas system is used by bacteria and archaea to fend off foreign genetic elements. Since its discovery it has been developed into numerous applications like genome editing and regulation of transcription in eukaryotes and bacteria. For archaea currently no tools for transcriptional repression exist. Because molecular biology analyses in archaea become more and more widespread such a tool is vital for investigating the biological function of essential genes in archaea. Here we use the model archaeon Haloferax volcanii to demonstrate that its endogenous CRISPR-Cas system I-B can be harnessed to repress gene expression in archaea. Deletion of cas3 and cas6b genes results in efficient repression of transcription. crRNAs targeting the promoter region reduced transcript levels down to 8%. crRNAs targeting the reading frame have only slight impact on transcription. crRNAs that target the coding strand repress expression only down to 88%, whereas crRNAs targeting the template strand repress expression down to 8%. Repression of an essential gene results in reduction of transcription levels down to 22%. Targeting efficiencies can be enhanced by expressing a catalytically inactive Cas3 mutant. Genes can be targeted on plasmids or on the chromosome, they can be monocistronic or part of a polycistronic operon. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Gene Repression in Haloarchaea Using the CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats)-Cas I-B System*

PubMed Central

Stachler, Aris-Edda; Marchfelder, Anita

2016-01-01

The clustered regularly interspaced short palindromic repeats (CRISPR)-Cas system is used by bacteria and archaea to fend off foreign genetic elements. Since its discovery it has been developed into numerous applications like genome editing and regulation of transcription in eukaryotes and bacteria. For archaea currently no tools for transcriptional repression exist. Because molecular biology analyses in archaea become more and more widespread such a tool is vital for investigating the biological function of essential genes in archaea. Here we use the model archaeon Haloferax volcanii to demonstrate that its endogenous CRISPR-Cas system I-B can be harnessed to repress gene expression in archaea. Deletion of cas3 and cas6b genes results in efficient repression of transcription. crRNAs targeting the promoter region reduced transcript levels down to 8%. crRNAs targeting the reading frame have only slight impact on transcription. crRNAs that target the coding strand repress expression only down to 88%, whereas crRNAs targeting the template strand repress expression down to 8%. Repression of an essential gene results in reduction of transcription levels down to 22%. Targeting efficiencies can be enhanced by expressing a catalytically inactive Cas3 mutant. Genes can be targeted on plasmids or on the chromosome, they can be monocistronic or part of a polycistronic operon. PMID:27226589

Post-transcriptional modifications in the small subunit ribosomal RNA from Thermotoga maritima, including presence of a novel modified cytidine

PubMed Central

Guymon, Rebecca; Pomerantz, Steven C.; Ison, J. Nicholas; Crain, Pamela F.; McCloskey, James A.

2007-01-01

Post-transcriptional modifications of RNA are nearly ubiquitous in the principal RNAs involved in translation. However, in the case of rRNA the functional roles of modification are far less established than for tRNA, and are subject to less knowledge in terms of specific nucleoside identities and their sequence locations. Post-transcriptional modifications have been studied in the SSU rRNA from Thermotoga maritima (optimal growth 80°C), one of the most deeply branched organisms in the Eubacterial phylogenetic tree. A total of 10 different modified nucleosides were found, the greatest number reported for bacterial SSU rRNA, occupying a net of ∼14 sequence sites, compared with a similar number of sites recently reported for Thermus thermophilus and 11 for Escherichia coli. The relatively large number of modifications in Thermotoga offers modest support for the notion that thermophile rRNAs are more extensively modified than those from mesophiles. Seven of the Thermotoga modified sites are identical (location and identity) to those in E. coli. An unusual derivative of cytidine was found, designated N-330 (M r 330.117), and was sequenced to position 1404 in the decoding region of the rRNA. It was unexpectedly found to be identical to an earlier reported nucleoside of unknown structure at the same location in the SSU RNA of the archaeal mesophile Haloferax volcanii. PMID:17255199

Identification of the Haloarchaeal Phasin (PhaP) That Functions in Polyhydroxyalkanoate Accumulation and Granule Formation in Haloferax mediterranei

PubMed Central

Cai, Shuangfeng; Cai, Lei; Liu, Hailong; Liu, Xiaoqing; Han, Jing; Zhou, Jian

2012-01-01

The polyhydroxyalkanoate (PHA) granule-associated proteins (PGAPs) are important for PHA synthesis and granule formation, but currently little is known about the haloarchaeal PGAPs. This study focused on the identification and functional analysis of the PGAPs in the haloarchaeon Haloferax mediterranei. These PGAPs were visualized with two-dimensional gel electrophoresis (2-DE) and identified by matrix-assisted laser desorption ionization–tandem time of flight mass spectrometry (MALDI-TOF/TOF MS). The most abundant protein on the granules was identified as a hypothetical protein, designated PhaP. A genome-wide analysis revealed that the phaP gene is located upstream of the previously identified phaEC genes. Through an integrative approach of gene knockout/complementation and fermentation analyses, we demonstrated that this PhaP is involved in PHA accumulation. The ΔphaP mutant was defective in both PHA biosynthesis and cell growth compared to the wild-type strain. Additionally, transmission electron microscopy results indicated that the number of PHA granules in the ΔphaP mutant cells was significantly lower, and in most of the ΔphaP cells only a single large granule was observed. These results demonstrated that the H. mediterranei PhaP was the predominant structure protein (phasin) on the PHA granules involved in PHA accumulation and granule formation. In addition, BLASTp and phylogenetic results indicate that this type of PhaP is exclusively conserved in haloarchaea, implying that it is a representative of the haloarchaeal type PHA phasin. PMID:22247127

Peroxisome proliferator-activated receptor {alpha}-independent peroxisome proliferation

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

Zhang Xiuguo; Tanaka, Naoki; Nakajima, Takero

2006-08-11

Hepatic peroxisome proliferation, increases in the numerical and volume density of peroxisomes, is believed to be closely related to peroxisome proliferator-activated receptor {alpha} (PPAR{alpha}) activation; however, it remains unknown whether peroxisome proliferation depends absolutely on this activation. To verify occurrence of PPAR{alpha}-independent peroxisome proliferation, fenofibrate treatment was used, which was expected to significantly enhance PPAR{alpha} dependence in the assay system. Surprisingly, a novel type of PPAR{alpha}-independent peroxisome proliferation and enlargement was uncovered in PPAR{alpha}-null mice. The increased expression of dynamin-like protein 1, but not peroxisome biogenesis factor 11{alpha}, might be associated with the PPAR{alpha}-independent peroxisome proliferation at least in part.

Evolutionary consequences of polyploidy in prokaryotes and the origin of mitosis and meiosis.

PubMed

Markov, Alexander V; Kaznacheev, Ilya S

2016-06-08

The origin of eukaryote-specific traits such as mitosis and sexual reproduction remains disputable. There is growing evidence that both mitosis and eukaryotic sex (i.e., the alternation of syngamy and meiosis) may have already existed in the basal eukaryotes. The mating system of the halophilic archaeon Haloferax volcanii probably represents an intermediate stage between typical prokaryotic and eukaryotic sex. H. volcanii is highly polyploid, as well as many other Archaea. Here, we use computer simulation to explore genetic and evolutionary outcomes of polyploidy in amitotic prokaryotes and its possible role in the origin of mitosis, meiosis and eukaryotic sex. Modeling suggests that polyploidy can confer strong short-term evolutionary advantage to amitotic prokaryotes. However, it also promotes the accumulation of recessive deleterious mutations and the risk of extinction in the long term, especially in highly mutagenic environment. There are several possible strategies that amitotic polyploids can use in order to reduce the genetic costs of polyploidy while retaining its benefits. Interestingly, most of these strategies resemble different components or aspects of eukaryotic sex. They include asexual ploidy cycles, equalization of genome copies by gene conversion, high-frequency lateral gene transfer between relatives, chromosome exchange coupled with homologous recombination, and the evolution of more accurate chromosome distribution during cell division (mitosis). Acquisition of mitosis by an amitotic polyploid results in chromosome diversification and specialization. Ultimately, it transforms a polyploid cell into a functionally monoploid one with multiple unique, highly redundant chromosomes. Specialization of chromosomes makes the previously evolved modes of promiscuous chromosome shuffling deleterious. This can result in selective pressure to develop accurate mechanisms of homolog pairing, and, ultimately, meiosis. Emergence of mitosis and the first

Mass production of C50 carotenoids by Haloferax mediterranei in using extruded rice bran and starch under optimal conductivity of brined medium.

PubMed

Chen, C Will; Hsu, Shu-hui; Lin, Ming-Tse; Hsu, Yi-hui

2015-12-01

Microbial carotenoids have potentially healthcare or medical applications. Haloferax mediterranei was difficult to economically grow into a large quantities as well as producing a valuable pigment of carotenoids. This study reports a novel investigation into the optimal conductivity on the mass production of carotenoids from H. mediterranei. The major component at about 52.4% in the extracted red pigment has been confirmed as bacterioruberin, a C50 carotenoids, by liquid chromatography separation and mass spectrometry analysis. By maintaining higher conductivity of 40 S/m in the brined medium, the cell concentration attained to 7.73 × 10(9) cells/L with low pigments concentration of 125 mg/L. When the conductivity was controlled at about 30 S/m, we obtained the highest cell concentration to 1.29 × 10(10) cells/L with pigments of 361.4 mg/L. When the conductivity was maintained at optimal 25 S/m, the pigments can be increased to maximum value of 555.6 mg/L at lower cell concentration of 9.22 × 10(9) cells/L. But conductivity below 20 S/m will cause the significant decrease in cell concentration as well as pigments due to the osmotic stress around the cells. Red pigment of carotenoids from an extremely halophilic archaebacterium could be efficiently produced to a high concentration by applying optimal conductivity control in the brined medium with extruded low-cost rice bran and corn starch.

Interactions of RadB, a DNA repair protein in archaea, with DNA and ATP.

PubMed

Guy, Colin P; Haldenby, Sam; Brindley, Amanda; Walsh, David A; Briggs, Geoffrey S; Warren, Martin J; Allers, Thorsten; Bolt, Edward L

2006-04-21

The RecA family of recombinases (RecA, Rad51, RadA and UvsX) catalyse strand-exchange between homologous DNA molecules by utilising conserved DNA-binding modules and a common core ATPase domain. RadB was identified in archaea as a Rad51-like protein on the basis of conserved ATPase sequences. However, RadB does not catalyse strand exchange and does not turn over ATP efficiently. RadB does bind DNA, and here we report a triplet of residues (Lys-His-Arg) that is highly conserved at the RadB C terminus, and is crucial for DNA binding. This is consistent with the motif forming a "basic patch" of highly conserved residues identified in an atomic structure of RadB from Thermococcus kodakaraensis. As the triplet motif is conserved at the C terminus of XRCC2 also, a mammalian Rad51-paralogue, we present a phylogenetic analysis that clarifies the relationship between RadB, Rad51-paralogues and recombinases. We investigate interactions between RadB and ATP using genetics and biochemistry; ATP binding by RadB is needed to promote survival of Haloferax volcanii after UV irradiation, and ATP, but not other NTPs, induces pronounced conformational change in RadB. This is the first genetic analysis of radB, and establishes its importance for maintaining genome stability in archaea. ATP-induced conformational change in RadB may explain previous reports that RadB controls Holliday junction resolution by Hjc, depending on the presence or the absence of ATP.

Identification and codon reading properties of 5-cyanomethyl uridine, a new modified nucleoside found in the anticodon wobble position of mutant haloarchaeal isoleucine tRNAs

PubMed Central

Mandal, Debabrata; Köhrer, Caroline; Su, Dan; Babu, I. Ramesh; Chan, Clement T.Y.; Liu, Yuchen; Söll, Dieter; Blum, Paul; Kuwahara, Masayasu; Dedon, Peter C.; RajBhandary, Uttam L.

2014-01-01

Most archaea and bacteria use a modified C in the anticodon wobble position of isoleucine tRNA to base pair with A but not with G of the mRNA. This allows the tRNA to read the isoleucine codon AUA without also reading the methionine codon AUG. To understand why a modified C, and not U or modified U, is used to base pair with A, we mutated the C34 in the anticodon of Haloarcula marismortui isoleucine tRNA (tRNA2Ile) to U, expressed the mutant tRNA in Haloferax volcanii, and purified and analyzed the tRNA. Ribosome binding experiments show that although the wild-type tRNA2Ile binds exclusively to the isoleucine codon AUA, the mutant tRNA binds not only to AUA but also to AUU, another isoleucine codon, and to AUG, a methionine codon. The G34 to U mutant in the anticodon of another H. marismortui isoleucine tRNA species showed similar codon binding properties. Binding of the mutant tRNA to AUG could lead to misreading of the AUG codon and insertion of isoleucine in place of methionine. This result would explain why most archaea and bacteria do not normally use U or a modified U in the anticodon wobble position of isoleucine tRNA for reading the codon AUA. Biochemical and mass spectrometric analyses of the mutant tRNAs have led to the discovery of a new modified nucleoside, 5-cyanomethyl U in the anticodon wobble position of the mutant tRNAs. 5-Cyanomethyl U is present in total tRNAs from euryarchaea but not in crenarchaea, eubacteria, or eukaryotes. PMID:24344322

Analysis of the Transcriptional Regulator GlpR, Promoter Elements, and Posttranscriptional Processing Involved in Fructose-Induced Activation of the Phosphoenolpyruvate-Dependent Sugar Phosphotransferase System in Haloferax mediterranei

PubMed Central

Cai, Lei; Cai, Shuangfeng; Zhao, Dahe; Wu, Jinhua; Wang, Lei; Liu, Xiaoqing; Li, Ming; Hou, Jing; Zhou, Jian; Liu, Jingfang; Han, Jing

2014-01-01

Among all known archaeal strains, the phosphoenolpyruvate-dependent phosphotransferase system (PTS) for fructose utilization is used primarily by haloarchaea, which thrive in hypersaline environments, whereas the molecular details of the regulation of the archaeal PTS under fructose induction remain unclear. In this study, we present a comprehensive examination of the regulatory mechanism of the fructose PTS in the haloarchaeon Haloferax mediterranei. With gene knockout and complementation, microarray analysis, and chromatin immunoprecipitation-quantitative PCR (ChIP-qPCR), we revealed that GlpR is the indispensable activator, which specifically binds to the PTS promoter (PPTS) during fructose induction. Further promoter-scanning mutation indicated that three sites located upstream of the H. mediterranei PPTS, which are conserved in most haloarchaeal PPTSs, are involved in this induction. Interestingly, two PTS transcripts (named T8 and T17) with different lengths of 5′ untranslated region (UTR) were observed, and promoter or 5′ UTR swap experiments indicated that the shorter 5′ UTR was most likely generated from the longer one. Notably, the translation efficiency of the transcript with this shorter 5′ UTR was significantly higher and the ratio of T8 (with the shorter 5′ UTR) to T17 increased during fructose induction, implying that a posttranscriptional mechanism is also involved in PTS activation. With these insights into the molecular regulation of the haloarchaeal PTS, we have proposed a working model for haloarchaea in response to environmental fructose. PMID:24334671

Production of poly-3-(hydroxybutyrate-co-hydroxyvalerate) by Haloferax mediterranei using rice-based ethanol stillage with simultaneous recovery and re-use of medium salts.

PubMed

Bhattacharyya, Anirban; Saha, Jayeeta; Haldar, Saubhik; Bhowmic, Asit; Mukhopadhyay, Ujjal Kumar; Mukherjee, Joydeep

2014-03-01

Haloferax mediterranei holds promise for competitive industrial-scale production of polyhydroxyalkanoate (PHA) because cheap carbon sources can be used thus lowering production costs. Although high salt concentration in production medium permits a non-sterile, low-cost process, salt disposal after process completion is a problem as current environmental standards do not allow total dissolved solids (TDS) above 2000 mg/l in discharge water. As the first objective of this work, the waste product of rice-based ethanol industry, stillage, was used for the production of PHA by H. mediterranei in shake flasks. Utilization of raw stillage led to 71 ± 2% (of dry cell weight) PHA accumulation and 16.42 ± 0.02 g/l PHA production. The product yield coefficient was 0.35 while 0.17 g/l h volumetric productivity was attained. Simultaneous reduction of BOD5 and COD values of stillage by 83% was accomplished. The PHA was isolated by osmotic lysis of cells, purification by sodium dodecyl sulfate and organic solvents. The biopolymer was identified as poly-3-(hydroxybutyrate-co-15.4 mol%-hydroxyvalerate) (PHBV). This first report on utilization of rice-based ethanol stillage for PHBV production by H. mediterranei is currently the most cost effective. As the second objective, directional properties of decanoic acid together with temperature dependence of water solubility in decanoic acid were applied for two-stage desalination of the spent stillage medium. We report for the first time, recovery and re-use of 96% of the medium salts for PHA production thus removing the major bottleneck in the potential application of H. mediterranei for industrial production of PHBV. Final discharge water had TDS content of 670 mg/l.

Archaeal Inorganic Pyrophosphatase Displays Robust Activity under High-Salt Conditions and in Organic Solvents.

PubMed

McMillan, Lana J; Hepowit, Nathaniel L; Maupin-Furlow, Julie A

2016-01-15

Soluble inorganic pyrophosphatases (PPAs) that hydrolyze inorganic pyrophosphate (PPi) to orthophosphate (Pi) are commonly used to accelerate and detect biosynthetic reactions that generate PPi as a by-product. Current PPAs are inactivated by high salt concentrations and organic solvents, which limits the extent of their use. Here we report a class A type PPA of the haloarchaeon Haloferax volcanii (HvPPA) that is thermostable and displays robust PPi-hydrolyzing activity under conditions of 25% (vol/vol) organic solvent and salt concentrations from 25 mM to 3 M. HvPPA was purified to homogeneity as a homohexamer by a rapid two-step method and was found to display non-Michaelis-Menten kinetics with a Vmax of 465 U · mg(-1) for PPi hydrolysis (optimal at 42°C and pH 8.5) and Hill coefficients that indicated cooperative binding to PPi and Mg(2+). Similarly to other class A type PPAs, HvPPA was inhibited by sodium fluoride; however, hierarchical clustering and three-dimensional (3D) homology modeling revealed HvPPA to be distinct in structure from characterized PPAs. In particular, HvPPA was highly negative in surface charge, which explained its extreme resistance to organic solvents. To demonstrate that HvPPA could drive thermodynamically unfavorable reactions to completion under conditions of reduced water activity, a novel coupled assay was developed; HvPPA hydrolyzed the PPi by-product generated in 2 M NaCl by UbaA (a "salt-loving" noncanonical E1 enzyme that adenylates ubiquitin-like proteins in the presence of ATP). Overall, we demonstrate HvPPA to be useful for hydrolyzing PPi under conditions of reduced water activity that are a hurdle to current PPA-based technologies. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Archaeal Inorganic Pyrophosphatase Displays Robust Activity under High-Salt Conditions and in Organic Solvents

PubMed Central

McMillan, Lana J.; Hepowit, Nathaniel L.

2015-01-01

Soluble inorganic pyrophosphatases (PPAs) that hydrolyze inorganic pyrophosphate (PPi) to orthophosphate (Pi) are commonly used to accelerate and detect biosynthetic reactions that generate PPi as a by-product. Current PPAs are inactivated by high salt concentrations and organic solvents, which limits the extent of their use. Here we report a class A type PPA of the haloarchaeon Haloferax volcanii (HvPPA) that is thermostable and displays robust PPi-hydrolyzing activity under conditions of 25% (vol/vol) organic solvent and salt concentrations from 25 mM to 3 M. HvPPA was purified to homogeneity as a homohexamer by a rapid two-step method and was found to display non-Michaelis-Menten kinetics with a Vmax of 465 U · mg−1 for PPi hydrolysis (optimal at 42°C and pH 8.5) and Hill coefficients that indicated cooperative binding to PPi and Mg2+. Similarly to other class A type PPAs, HvPPA was inhibited by sodium fluoride; however, hierarchical clustering and three-dimensional (3D) homology modeling revealed HvPPA to be distinct in structure from characterized PPAs. In particular, HvPPA was highly negative in surface charge, which explained its extreme resistance to organic solvents. To demonstrate that HvPPA could drive thermodynamically unfavorable reactions to completion under conditions of reduced water activity, a novel coupled assay was developed; HvPPA hydrolyzed the PPi by-product generated in 2 M NaCl by UbaA (a “salt-loving” noncanonical E1 enzyme that adenylates ubiquitin-like proteins in the presence of ATP). Overall, we demonstrate HvPPA to be useful for hydrolyzing PPi under conditions of reduced water activity that are a hurdle to current PPA-based technologies. PMID:26546423

A Patatin-Like Protein Associated with the Polyhydroxyalkanoate (PHA) Granules of Haloferax mediterranei Acts as an Efficient Depolymerase in the Degradation of Native PHA

PubMed Central

Liu, Guiming; Hou, Jing; Cai, Shuangfeng; Zhao, Dahe; Cai, Lei; Han, Jing; Zhou, Jian

2015-01-01

The key enzymes and pathways involved in polyhydroxyalkanoate (PHA) biosynthesis in haloarchaea have been identified in recent years, but the haloarchaeal enzymes for PHA degradation remain unknown. In this study, a patatin-like PHA depolymerase, PhaZh1, was determined to be located on the PHA granules in the haloarchaeon Haloferax mediterranei. PhaZh1 hydrolyzed the native PHA (nPHA) [including native polyhydroxybutyrate (nPHB) and native poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (nPHBV) in this study] granules in vitro with 3-hydroxybutyrate (3HB) monomer as the primary product. The site-directed mutagenesis of PhaZh1 indicated that Gly16, Ser47 (in a classical lipase box, G-X-S47-X-G), and Asp195 of this depolymerase were essential for its activity in nPHA granule hydrolysis. Notably, phaZh1 and bdhA (encoding putative 3HB dehydrogenase) form a gene cluster (HFX_6463 to _6464) in H. mediterranei. The 3HB monomer generated from nPHA degradation by PhaZh1 could be further converted into acetoacetate by BdhA, indicating that PhaZh1-BdhA may constitute the first part of a PHA degradation pathway in vivo. Interestingly, although PhaZh1 showed efficient activity and was most likely the key enzyme in nPHA granule hydrolysis in vitro, the knockout of phaZh1 had no significant effect on the intracellular PHA mobilization, implying the existence of an alternative PHA mobilization pathway(s) that functions effectively within the cells of H. mediterranei. Therefore, identification of this patatin-like depolymerase of haloarchaea may provide a new strategy for producing the high-value-added chiral compound (R)-3HB and may also shed light on the PHA mobilization in haloarchaea. PMID:25710370

Integration of poly-3-(hydroxybutyrate-co-hydroxyvalerate) production by Haloferax mediterranei through utilization of stillage from rice-based ethanol manufacture in India and its techno-economic analysis.

PubMed

Bhattacharyya, Anirban; Jana, Kuntal; Haldar, Saubhik; Bhowmic, Asit; Mukhopadhyay, Ujjal Kumar; De, Sudipta; Mukherjee, Joydeep

2015-05-01

Haloferax mediterranei has potential for economical industrial-scale production of polyhydroxyalkanoate (PHA) as it can utilize cheap carbon sources, has capacity for nonsterile cultivation and allows simple product recovery. Molasses-based Indian distilleries are converting themselves to cereal-based distilleries. Waste stillage (14 l) of rice-based ethanol industry was used for the production of PHA by H. mediterranei in the simple plug-flow reactor configuration of the activated sludge process. Cells utilized stillage and accumulated 63 ± 3 % PHA of dry cell weight and produced 13.12 ± 0.05 g PHA/l. The product yield coefficient was 0.27 while 0.14 g/l h volumetric productivity was reached. Simultaneous lowering of 5-day biochemical oxygen demand and chemical oxygen demand values of stillage by 82 % was attained. The biopolymer was characterized as poly-3-(hydroxybutyrate-co-17.9 mol%-hydroxyvalerate) (PHBV). Directional properties of decanoic acid jointly with temperature-dependent water solubility in decanoic acid were employed for two-step desalination of the spent stillage medium in a cylindrical baffled-tank with an immersed heater and a stirrer holding axial and radial impellers. 99.3 % of the medium salts were recovered and re-used for PHA production. The cost of PHBV was estimated as US$2.05/kg when the annual production was simulated as 1890 tons. Desalination contributed maximally to the overall cost. Technology and cost-analysis demonstrate that PHA production integrated with ethanol manufacture is feasible in India. This study could be the basis for construction of a pilot plant.

Neural control of colonic cell proliferation.

PubMed

Tutton, P J; Barkla, D H

1980-03-15

The mitotic rate in rat colonic crypts and in dimethylhydrazine-induced colonic carcinomas was measured using a stathmokinetic technique. In sympathectomized animals cell proliferation was retarded in the crypts but not in the tumors, whereas in animals treated with Metaraminol, a drug which releases norepinephrine from nerve terminals, crypt cell but not tumor cell proliferation was accelerated. Blockade of alpha-adrenoceptors also inhibited crypt cell proliferation. However, stimulation of beta-adrenoceptors inhibited and blockade of beta-adrenoceptors accelerated tumor cell proliferation without influencing crypt cell proliferation. Injection of either serotonin or histamine stimulated tumor but not crypt cell proliferation and blockade or serotonin receptors or histamine H2-receptors inhibited tumor cell proliferation. It is postulated that cell proliferation in the colonic crypts, like that in the jejunal crypts, is under both endocrine and autonomic neural control whereas colonic tumor cell division is subject to endocrine regulation alone.

Identification of transcriptional networks involved in peroxisome proliferator chemical-induced hepatocyte proliferation

EPA Science Inventory

Peroxisome proliferator chemical (PPC) exposure leads to increases in rodent liver tumors through a non-genotoxic mode of action (MOA). The PPC MOA includes increased oxidative stress, hepatocyte proliferation and decreased apoptosis. We investigated the putative genetic regulato...

Nuclear Proliferation: A Historical Overview

DTIC Science & Technology

2008-03-01

Talbert, “Nuclear Proliferation Technology Trends Analysis ,” Pacific Northwest National Laboratory, PNNL -14480 (September 2005), p. 92. 1973: Closed...L. Coles, and R. J. Talbert, “Nuclear Proliferation Technology Trends Analysis ,” Pacific Northwest National Laboratory, PNNL -14480 (September 2005...D. Zentner, G. L. Coles, and R. J. Talbert, “Nuclear Proliferation Technology Trends Analysis ,” Pacific Northwest National Laboratory, PNNL -14480

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

Proliferating cell nuclear antigen (PCNA): a new marker to study human colonic cell proliferation.

PubMed Central

Kubben, F J; Peeters-Haesevoets, A; Engels, L G; Baeten, C G; Schutte, B; Arends, J W; Stockbrügger, R W; Blijham, G H

1994-01-01

Immunohistochemistry of the S phase related proliferating cell nuclear antigen (PCNA) was studied as an alternative to ex-vivo bromodeoxyuridine (BrdU) immunohistochemistry for assessment of human colonic cell proliferation. From 16 subjects without colonic disease biopsy specimens were collected from five different sites along the colorectum and processed for BrdU and PCNA immunohistochemistry. The mean proliferation index of PCNA was significantly higher at 133% of the value obtained with BrdU. There was, however, a good correlation between the results from both techniques (r = 0.6275; p < 0.05). Decrease in proliferation index along the colorectum was seen with both staining methods but was clearer with PCNA immunohistochemistry (caecum/ascending colon v rectum: 12.0 v 7.2; p < 0.004). The total number of crypt cells also decreased from proximal to distal (134 to 128; p < 0.06) but at no site correlated significantly with the proliferation index. It is concluded that in clinical cell kinetic studies staining for PCNA may serve as an attractive alternative to the BrdU incorporation assay. Images Figure 4 PMID:7909785

Resistance of extremely halophilic archaea to zinc and zinc oxide nanoparticles

NASA Astrophysics Data System (ADS)

Salgaonkar, Bhakti B.; Das, Deepthi; Bragança, Judith Maria

2016-02-01

Industrialization as well as other anthropogenic activities have resulted in addition of high loads of metal and/or metal nanoparticles to the environment. In this study, the effect of one of the widely used heavy metal, zinc (Zn) and zinc oxide nanoparticles (ZnO NPs) on extremely halophilic archaea was evaluated. One representative member from four genera namely Halococcus, Haloferax, Halorubrum and Haloarcula of the family Halobacteriaceae was taken as the model organism. All the haloarchaeal genera investigated were resistant to both ZnCl2 and ZnO NPs at varying concentrations. Halococcus strain BK6 and Haloferax strain BBK2 showed the highest resistance in complex/minimal medium of up to 2.0/1.0 mM ZnCl2 and 2.0/1.0-0.5 mM ZnO NP. Accumulation of ZnCl2/ZnO NPs was seen as Haloferax strain BBK2 (287.2/549.6 mg g-1) > Halococcus strain BK6 (165.9/388.5 mg g-1) > Haloarcula strain BS2 (93.2/28.5 mg g-1) > Halorubrum strain BS17 (29.9/16.2 mg g-1). Scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM-EDX) analysis revealed that bulk ZnCl2 was sorbed at a higher concentration (21.77 %) on the cell surface of Haloferax strain BBK2 as compared to the ZnO NPs (14.89 %).

MicroRNA-2400 promotes bovine preadipocyte proliferation

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

Wei, Yao; Cui, Ya Feng; Tong, Hui Li

MicroRNAs (miRNAs) play critical roles in the proliferation of bovine preadipocytes. miR-2400 is a novel and unique miRNA from bovines. In the present study, we separated and identified preadipocytes from bovine samples. miR-2400 overexpression increased the rate of preadipocyte proliferation, which was analyzed with a combination of EdU and flow cytometry. Simultaneously, functional genes related to proliferation (PCNA, CCND2, CCNB1) were also increased, which was detected by real-time PCR. Furthermore, luciferase reporter assays showed that miR-2400 bound directly to the 3'untranslated regions (3′UTRs) of PRDM11 mRNA. These data suggested that miR-2400 could promote preadipocyte proliferation by targeting PRDM11. - Highlights:more » • miRNAs are important in bovine preadipocyte proliferation. • miR-2400 is a novel miRNA from bovines. • miR-2400 overexpression increased preadipocyte proliferation. • Functional genes related to preadipocyte proliferation were upregulated. • Preadipocyte proliferation was promoted by targeting PRDM11.« less

MECHANISMS INVOLVED IN THE ENHANCED SUSCEPTIBILITY OF SENESCENT RATS TO THE HEPATOCARCINOGENIC EFFECT OF PEROXISOME PROLIFERATORS: ROLE OF PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR ALPHA (PPARA), CELL PROLIFERATION AND OXIDATIVE STRESS

EPA Science Inventory

Mechanisms involved in the ENHANCED SUSCEPTIBILITY of SENESCENT Rats TO THE HEPATOCARCINOGENIC EFFECT OF PEROXISOME PROLIFERATORS: Role of peroxisome proliferator-activated receptor alpha (PPARa), cell proliferation and oxidative stress

Jihan A. Youssef1, Pierre Ammann2, B...

Proliferation resistance of small modular reactors fuels

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

Polidoro, F.; Parozzi, F.; Fassnacht, F.

2013-07-01

In this paper the proliferation resistance of different types of Small Modular Reactors (SMRs) has been examined and classified with criteria available in the literature. In the first part of the study, the level of proliferation attractiveness of traditional low-enriched UO{sub 2} and MOX fuels to be used in SMRs based on pressurized water technology has been analyzed. On the basis of numerical simulations both cores show significant proliferation risks. Although the MOX core is less proliferation prone in comparison to the UO{sub 2} core, it still can be highly attractive for diversion or undeclared production of nuclear material. Inmore » the second part of the paper, calculations to assess the proliferation attractiveness of fuel in typical small sodium cooled fast reactor show that proliferation risks from spent fuel cannot be neglected. The core contains a highly attractive plutonium composition during the whole life cycle. Despite some aspects of the design like the sealed core that enables easy detection of unauthorized withdrawal of fissile material and enhances proliferation resistance, in case of open Non-Proliferation Treaty break-out, weapon-grade plutonium in sufficient quantities could be extracted from the reactor core.« less

Regulators of Cholangiocyte Proliferation.

PubMed

Hall, Chad; Sato, Keisaku; Wu, Nan; Zhou, Tianhao; Kyritsi, Konstantina; Meng, Fanyin; Glaser, Shannon; Alpini, Gianfranco

2017-02-10

Cholangiocytes, a small population of cells within the normal liver, have been the focus of a significant amount of research over the past two decades because of their involvement in cholangiopathies such as primary sclerosing cholangitis and primary biliary cholangitis. This article summarizes landmark studies in the field of cholangiocyte physiology and aims to provide an updated review of biliary pathogenesis. The historical approach of rodent extrahepatic bile duct ligation and the relatively recent utilization of transgenic mice have led to significant discoveries in cholangiocyte pathophysiology. Cholangiocyte physiology is a complex system based on heterogeneity within the biliary tree and a number of signaling pathways that serve to regulate bile composition. Studies have expanded the list of neuropeptides, neurotransmitters, and hormones that have been shown to be key regulators of proliferation and biliary damage. The peptide histamine and hormones, such as melatonin and angiotensin, angiotensin, as well as numerous sex hormones, have been implicated in cholangiocyte proliferation during cholestasis. Numerous pathways promote cholangiocyte proliferation during cholestasis, and there is growing evidence to suggest that cholangiocyte proliferation may promote hepatic fibrosis. These pathways may represent significant therapeutic potential for a subset of cholestatic liver diseases that currently lack effective therapies.

Label Structured Cell Proliferation Models

DTIC Science & Technology

2010-06-16

and (, + ) are the cell proliferation and death rates , respectively, relative to the moving label coordinate system + . Daughter...proliferation and death rates relative to this new coordinate system. While not common in the biological sciences, it is altogether common in the physical

Dual effect of LPS on murine myeloid leukemia cells: Pro-proliferation and anti-proliferation

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

Yu, Lingling; Noncoding RNA Center, Yangzhou University, Yangzhou 225001; Zhao, Yingmin

Modification of the bone marrow microenvironment is considered as a promising strategy to control leukemic cell proliferation, diseases progression and relapse after treatment. However, due to the diversity and complexity of the cellular and molecular compartments in the leukemic microenvironment, it is extremely difficult to dissect the role of each individual molecule or cell type in vivo. Here we established an in vitro system to dissect the role of lipopolysaccharide (LPS), stromal cells and endothelial cells in the growth of mouse myeloid tumor cells and B-lymphoma cells. We found that either LPS or bone marrow stromal cells as a feedermore » layer in culture is required for the proliferation of myeloid tumor cells. Surprisingly, the growth of myeloid leukemic cells on stromal cells is strongly inhibited when coupled with LPS in culture. This opposing effect of LPS, a complete switch from pro-proliferation to antitumor growth is due, at least in part, to the rapidly increased production of interleukin 12, Fas ligand and tissue inhibitor of metalloproteinases-2 from stromal cells stimulated by LPS. These results demonstrate that LPS can either facilitate or attenuate tumor cell proliferation, thus changing the disease course of myeloid leukemias through its direct effect or modulation of the tumor microenvironment. - Highlights: • LPS alone in culture is required for the proliferation of murine myeloid tumor cells. • Bone marrow stromal cells as a feeder layer is also required for the proliferation of myeloid tumor cells. • However, the growth of myeloid tumor cells is inhibited when LPS and stromal cells are both available in culture. • Thus LPS can either facilitate or attenuate tumor growth through its direct effect or modulation of tumor microenvironment.« less

Ligand activation of peroxisome proliferator-activated receptor-beta/delta inhibits cell proliferation in human HaCaT keratinocytes.

PubMed

Borland, Michael G; Foreman, Jennifer E; Girroir, Elizabeth E; Zolfaghari, Reza; Sharma, Arun K; Amin, Shantu; Gonzalez, Frank J; Ross, A Catharine; Peters, Jeffrey M

2008-11-01

Although there is strong evidence that ligand activation of peroxisome proliferator-activated receptor (PPAR)-beta/delta induces terminal differentiation and attenuates cell growth, some studies suggest that PPARbeta/delta actually enhances cell proliferation. For example, it was suggested recently that retinoic acid (RA) is a ligand for PPARbeta/delta and potentiates cell proliferation by activating PPARbeta/delta. The present study examined the effect of ligand activation of PPARbeta/delta on cell proliferation, cell cycle kinetics, and target gene expression in human HaCaT keratinocytes using two highly specific PPARbeta/delta ligands [4-[[[2-[3-fluoro-4-(trifluoromethyl)phenyl]-4-methyl-5-thiazolyl]methyl]thio]-2-methylphenoxy acetic acid (GW0742) and 2-methyl-4-((4-methyl-2-(4-trifluoromethylphenyl)-1,3-thiazol-5-yl)-methylsulfanyl)phenoxy-acetic acid (GW501516)] and RA. Both PPARbeta/delta ligands and RA inhibited cell proliferation of HaCaT keratinocytes. GW0742 and GW501516 increased expression of known PPARbeta/delta target genes, whereas RA did not; RA increased the expression of known retinoic acid receptor/retinoid X receptor target genes, whereas GW0742 did not affect these genes. GW0742, GW501516, and RA did not modulate the expression of 3-phosphoinositide-dependent protein kinase or alter protein kinase B phosphorylation. GW0742 and RA increased annexin V staining as quantitatively determined by flow cytometry. The effects of GW0742 and RA were also examined in wild-type and PPARbeta/delta-null primary mouse keratinocytes to determine the specific role of PPARbeta/delta in modulating cell growth. Although inhibition of keratinocyte proliferation by GW0742 was PPARbeta/delta-dependent, inhibition of cell proliferation by RA occurred in both genotypes. Results from these studies demonstrate that ligand activation of PPARbeta/delta inhibits keratinocyte proliferation through PPARbeta/delta-dependent mechanisms. In contrast, the observed inhibition of

Low-grade myofibroblastic proliferations of the urinary bladder.

PubMed

Alquati, Sara; Gira, Federica Alessandra; Bartoli, Veronica; Contini, Sandro; Corradi, Domenico

2013-08-01

Myofibroblastic proliferations of the urinary bladder, which share some similarities with nodular fasciitis, were first reported in 1980. Since then, they have had several designations, the most frequently used being inflammatory myofibroblastic tumor. Based on both histopathologic and prognostic grounds, some authors prefer the term pseudosarcomatous myofibroblastic proliferation, at least for some of the proliferations. These same scientists also assimilate the so-called postoperative spindle cell nodules with the pseudosarcomatous myofibroblastic proliferations. Little is known about these low-grade myofibroblastic proliferations. To review the literature about low-grade myofibroblastic proliferations occurring in the urinary bladder. Textbooks and literature review. We obtained most of the clinicopathologic peculiarities from a patient population composed of the most-relevant, previously reported cases. The low-grade myofibroblastic proliferations of the urinary bladder are rare lesions affecting males more often than they do females. The most-common signs and symptoms are hematuria and dysuria. Histopathologically, they are spindle cell proliferations in a loose myxoid stroma, even though compact proliferations or hypocellular fibrous patterns can be found. Immunohistochemistry is quite nonspecific, except for ALK-1 positivity (20%-89%). Fluorescence in situ hybridization has demonstrated clonal genetic aberrations involving the ALK gene in 50% to 60% of cases. After surgery, only 6% of patients experience local recurrence, without metastases or deaths from the disease. Malignant transformation has been reported exceptionally. These myofibroblastic proliferations are probably part of a continuum with, at one end, benign pseudosarcomatous proliferations and, at the opposite end, more-aggressive lesions. Because of the frequently indolent clinical course, aggressive treatment would be unjustified.

Ligand Activation of Peroxisome Proliferator-Activated Receptor-β/δ Inhibits Cell Proliferation in Human HaCaT KeratinocytesS

PubMed Central

Borland, Michael G.; Foreman, Jennifer E.; Girroir, Elizabeth E.; Zolfaghari, Reza; Sharma, Arun K.; Amin, Shantu; Gonzalez, Frank J.; Ross, A. Catharine; Peters, Jeffrey M.

2009-01-01

Although there is strong evidence that ligand activation of peroxisome proliferator-activated receptor (PPAR)-β/δ induces terminal differentiation and attenuates cell growth, some studies suggest that PPARβ/δ actually enhances cell proliferation. For example, it was suggested recently that retinoic acid (RA) is a ligand for PPARβ/δ and potentiates cell proliferation by activating PPARβ/δ. The present study examined the effect of ligand activation of PPARβ/δ on cell proliferation, cell cycle kinetics, and target gene expression in human HaCaT keratinocytes using two highly specific PPARβ/δ ligands [4-[[[2-[3-fluoro-4-(trifluoromethyl)phenyl]-4-methyl-5-thiazolyl]methyl]thio]-2-methylphenoxy acetic acid (GW0742) and 2-methyl-4-((4-methyl-2-(4-trifluoromethylphenyl)-1,3-thiazol-5-yl)-methylsulfanyl)phenoxy-acetic acid (GW501516)] and RA. Both PPARβ/δ ligands and RA inhibited cell proliferation of HaCaT keratinocytes. GW0742 and GW501516 increased expression of known PPARβ/δ target genes, whereas RA did not; RA increased the expression of known retinoic acid receptor/retinoid X receptor target genes, whereas GW0742 did not affect these genes. GW0742, GW501516, and RA did not modulate the expression of 3-phosphoinositide-dependent protein kinase or alter protein kinase B phosphorylation. GW0742 and RA increased annexin V staining as quantitatively determined by flow cytometry. The effects of GW0742 and RA were also examined in wild-type and PPARβ/δ-null primary mouse keratinocytes to determine the specific role of PPARβ/δ in modulating cell growth. Although inhibition of keratinocyte proliferation by GW0742 was PPARβ/δ-dependent, inhibition of cell proliferation by RA occurred in both genotypes. Results from these studies demonstrate that ligand activation of PPARβ/δ inhibits keratinocyte proliferation through PPARβ/δ-dependent mechanisms. In contrast, the observed inhibition of cell proliferation in mouse and human keratinocytes by RA is

Perchlorate and halophilic prokaryotes: implications for possible halophilic life on Mars.

PubMed

Oren, Aharon; Elevi Bardavid, Rahel; Mana, Lily

2014-01-01

In view of the finding of perchlorate among the salts detected by the Phoenix Lander on Mars, we investigated the relationships of halophilic heterotrophic microorganisms (archaea of the family Halobacteriaceae and the bacterium Halomonas elongata) toward perchlorate. All strains tested grew well in NaCl-based media containing 0.4 M perchlorate, but at the highest perchlorate concentrations, tested cells were swollen or distorted. Some species (Haloferax mediterranei, Haloferax denitrificans, Haloferax gibbonsii, Haloarcula marismortui, Haloarcula vallismortis) could use perchlorate as an electron acceptor for anaerobic growth. Although perchlorate is highly oxidizing, its presence at a concentration of 0.2 M for up to 2 weeks did not negatively affect the ability of a yeast extract-based medium to support growth of the archaeon Halobacterium salinarum. These findings show that presence of perchlorate among the salts on Mars does not preclude the possibility of halophilic life. If indeed the liquid brines that may exist on Mars are inhabited by salt-requiring or salt-tolerant microorganisms similar to the halophiles on Earth, presence of perchlorate may even be stimulatory when it can serve as an electron acceptor for respiratory activity in the anaerobic Martian environment.

Biology and survival of extremely halophilic archaeon Haloarcula marismortui RR12 isolated from Mumbai salterns, India in response to salinity stress.

PubMed

Thombre, Rebecca S; Shinde, Vinaya D; Oke, Radhika S; Dhar, Sunil Kumar; Shouche, Yogesh S

2016-05-27

Haloarchaea are unique microorganism's resistant to environmental and osmotic stresses and thrive in their habitats despite extreme fluctuating salinities. In the present study, haloarchaea were isolated from hypersaline thalossohaline salterns of Bhandup, Mumbai, India and were identified as Haloferax prahovense, Haloferax alexandrines, Haloferax lucentense, Haloarcula tradensis, Haloarcula marismortui and Haloarcula argentinensis. The mechanism of adaptation to contrasting salinities (1.5 M and 4.5 M) was investigated in the extreme haloarchaeon, Hal. marismortui RR12. Hal. marismortui RR12 increased the intracellular sequestration of K(+) and Cl(-) ions in hypo salinity and hyper salinity respectively as detected by Energy-dispersive X-ray spectroscopy microanalysis (EDAX) and Inductively Coupled Plasma- atomic Emission Spectroscopy (ICP-AES) indicating the presence of 'salt-in' strategy of osmoadaptation. As a cellular response to salinity stress, it produced small heat shock like proteins (sHSP) identified using MALDI-TOF MS and increased the production of protective red carotenoid pigment. This is the first report on the study of the concomitant cellular, molecular and physiological mechanism adapted by Hal. marismortui RR12 when exposed to contrasting salinities in external environment.

Succinyl-CoA:Mesaconate CoA-Transferase and Mesaconyl-CoA Hydratase, Enzymes of the Methylaspartate Cycle in Haloarcula hispanica.

PubMed

Borjian, Farshad; Johnsen, Ulrike; Schönheit, Peter; Berg, Ivan A

2017-01-01

Growth on acetate or other acetyl-CoA-generating substrates as a sole source of carbon requires an anaplerotic pathway for the conversion of acetyl-CoA into cellular building blocks. Haloarchaea (class Halobacteria ) possess two different anaplerotic pathways, the classical glyoxylate cycle and the novel methylaspartate cycle. The methylaspartate cycle was discovered in Haloarcula spp. and operates in ∼40% of sequenced haloarchaea. In this cycle, condensation of one molecule of acetyl-CoA with oxaloacetate gives rise to citrate, which is further converted to 2-oxoglutarate and then to glutamate. The following glutamate rearrangement and deamination lead to mesaconate (methylfumarate) that needs to be activated to mesaconyl-C1-CoA and hydrated to β-methylmalyl-CoA. The cleavage of β-methylmalyl-CoA results in the formation of propionyl-CoA and glyoxylate. The carboxylation of propionyl-CoA and the condensation of glyoxylate with another acetyl-CoA molecule give rise to two C 4 -dicarboxylic acids, thus regenerating the initial acetyl-CoA acceptor and forming malate, its final product. Here we studied two enzymes of the methylaspartate cycle from Haloarcula hispanica , succinyl-CoA:mesaconate CoA-transferase (mesaconate CoA-transferase, Hah_1336) and mesaconyl-CoA hydratase (Hah_1340). Their genes were heterologously expressed in Haloferax volcanii , and the corresponding enzymes were purified and characterized. Mesaconate CoA-transferase was specific for its physiological substrates, mesaconate and succinyl-CoA, and produced only mesaconyl-C1-CoA and no mesaconyl-C4-CoA. Mesaconyl-CoA hydratase had a 3.5-fold bias for the physiological substrate, mesaconyl-C1-CoA, compared to mesaconyl-C4-CoA, and virtually no activity with other tested enoyl-CoA/3-hydroxyacyl-CoA compounds. Our results further prove the functioning of the methylaspartate cycle in haloarchaea and suggest that mesaconate CoA-transferase and mesaconyl-CoA hydratase can be regarded as

The Role of Multiple Transcription Factors In Archaeal Gene Expression

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

Charles J. Daniels

2008-09-23

Since the inception of this research program, the project has focused on two central questions: What is the relationship between the 'eukaryal-like' transcription machinery of archaeal cells and its counterparts in eukaryal cells? And, how does the archaeal cell control gene expression using its mosaic of eukaryal core transcription machinery and its bacterial-like transcription regulatory proteins? During the grant period we have addressed these questions using a variety of in vivo approaches and have sought to specifically define the roles of the multiple TATA binding protein (TBP) and TFIIB-like (TFB) proteins in controlling gene expression in Haloferax volcanii. H. volcaniimore » was initially chosen as a model for the Archaea based on the availability of suitable genetic tools; however, later studies showed that all haloarchaea possessed multiple tbp and tfb genes, which led to the proposal that multiple TBP and TFB proteins may function in a manner similar to alternative sigma factors in bacterial cells. In vivo transcription and promoter analysis established a clear relationship between the promoter requirements of haloarchaeal genes and those of the eukaryal RNA polymerase II promoter. Studies on heat shock gene promoters, and the demonstration that specific tfb genes were induced by heat shock, provided the first indication that TFB proteins may direct expression of specific gene families. The construction of strains lacking tbp or tfb genes, coupled with the finding that many of these genes are differentially expressed under varying growth conditions, provided further support for this model. Genetic tools were also developed that led to the construction of insertion and deletion mutants, and a novel gene expression scheme was designed that allowed the controlled expression of these genes in vivo. More recent studies have used a whole genome array to examine the expression of these genes and we have established a linkage between the expression of

Financial incentives for reducing proliferation risks

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

Weise, Rachel A.; Hund, Gretchen

This article submitted for publication to the Bulletin of Atomic Scientists explains the possible financial incentives for financial institutions and large integrators to reduce nuclear proliferation risks by including anti-proliferation measures in their due diligence and requiring their suppliers to meet heightened compliance standards. Because manufacturers of dual-use nuclear goods are diverse and numerous outreach is difficult. However, financial institutions and large integrators work with nearly all dual-use manufacturers, making financial institutions and integrators well-positioned to increase awareness of proliferation and trafficking risks throughout the nuclear supply chain

Teaching Activities on Horizontal Nuclear Proliferation.

ERIC Educational Resources Information Center

Zola, John

1990-01-01

Provides learning activities concerning the horizontal proliferation of nuclear weapons. Includes step-by-step directions for four activities: (1) the life cycle of nuclear weapons; (2) nuclear nonproliferation: pros and cons; (3) the nuclear power/nuclear weapons connection; and (4) managing nuclear proliferation. (NL)

15 CFR 12.2 - Undue proliferation.

Code of Federal Regulations, 2010 CFR

2010-01-01

..., he shall initiate an inquiry for the purpose of finding facts concerning the existence of undue... possible existence of undue proliferation. Such communications should be in writing and include supporting... regarding the possible existence of undue proliferation, the Secretary will determine whether there has been...

15 CFR 12.2 - Undue proliferation.

Code of Federal Regulations, 2011 CFR

2011-01-01

..., he shall initiate an inquiry for the purpose of finding facts concerning the existence of undue... possible existence of undue proliferation. Such communications should be in writing and include supporting... regarding the possible existence of undue proliferation, the Secretary will determine whether there has been...

Combating the Proliferation of Weapons of Mass Destruction.

ERIC Educational Resources Information Center

Jenkins, Bonnie

1997-01-01

Reveals the growing threat posed to all countries by the proliferation of weapons of mass destruction. Discusses the international effort combating this proliferation including the Nuclear Non-Proliferation Treaty, Strategic Arms Reduction Treaties, Biological Weapons Convention, and Chemical Weapons Convention. Also considers regional arms…

Myocilin Regulates Cell Proliferation and Survival*

PubMed Central

Joe, Myung Kuk; Kwon, Heung Sun; Cojocaru, Radu; Tomarev, Stanislav I.

2014-01-01

Myocilin, a causative gene for open angle glaucoma, encodes a secreted glycoprotein with poorly understood functions. To gain insight into its functions, we produced a stably transfected HEK293 cell line expressing myocilin under an inducible promoter and compared gene expression profiles between myocilin-expressing and vector control cell lines by a microarray analysis. A significant fraction of differentially expressed genes in myocilin-expressing cells was associated with cell growth and cell death, suggesting that myocilin may have a role in the regulation of cell growth and survival. Increased proliferation of myocilin-expressing cells was demonstrated by the WST-1 proliferation assay, direct cell counting, and immunostaining with antibodies against Ki-67, a cellular proliferation marker. Myocilin-containing conditioned medium also increased proliferation of unmodified HEK293 cells. Myocilin-expressing cells were more resistant to serum starvation-induced apoptosis than control cells. TUNEL-positive apoptotic cells were dramatically decreased, and two apoptotic marker proteins, cleaved caspase 7 and cleaved poly(ADP-ribose) polymerase, were significantly reduced in myocilin-expressing cells as compared with control cells under apoptotic conditions. In addition, myocilin-deficient mesenchymal stem cells exhibited reduced proliferation and enhanced susceptibility to serum starvation-induced apoptosis as compared with wild-type mesenchymal stem cells. Phosphorylation of ERK1/2 and its upstream kinases, c-Raf and MEK, was increased in myocilin-expressing cells compared with control cells. Elevated phosphorylation of ERK1/2 was also observed in the trabecular meshwork of transgenic mice expressing 6-fold higher levels of myocilin when compared with their wild-type littermates. These results suggest that myocilin promotes cell proliferation and resistance to apoptosis via the ERK1/2 MAPK signaling pathway. PMID:24563482

Proliferation resistance assessments during the design phase of a recycling facility as a means of reducing proliferation risks

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

Lindell, M.A.; Grape, S.; Haekansson, A.

The sustainability criterion for Gen IV nuclear energy systems inherently presumes the availability of efficient fuel recycling capabilities. One area for research on advanced fuel recycling concerns safeguards aspects of this type of facilities. Since a recycling facility may be considered as sensitive from a non-proliferation perspective, it is important to address these issues early in the design process, according to the principle of Safeguards By Design. Presented in this paper is a mode of procedure, where assessments of the proliferation resistance (PR) of a recycling facility for fast reactor fuel have been performed so as to identify the weakestmore » barriers to proliferation of nuclear material. Two supplementing established methodologies have been applied; TOPS (Technological Opportunities to increase Proliferation resistance of nuclear power Systems) and PR-PP (Proliferation Resistance and Physical Protection evaluation methodology). The chosen fuel recycling facility belongs to a small Gen IV lead-cooled fast reactor system that is under study in Sweden. A schematic design of the recycling facility, where actinides are separated using solvent extraction, has been examined. The PR assessment methodologies make it possible to pinpoint areas in which the facility can be improved in order to reduce the risk of diversion. The initial facility design may then be slightly modified and/or safeguards measures may be introduced to reduce the total identified proliferation risk. After each modification of design and/or safeguards implementation, a new PR assessment of the revised system can then be carried out. This way, each modification can be evaluated and new ways to further enhance the proliferation resistance can be identified. This type of iterative procedure may support Safeguards By Design in the planning of new recycling plants and other nuclear facilities. (authors)« less

Intermittent pressure decreases human keratinocyte proliferation in vitro.

PubMed

Nasca, Maria R; Shih, Alan T; West, Dennis P; Martinez, Wanda M; Micali, Giuseppe; Landsman, Adam S

2007-01-01

The aim of this study was to investigate the correlation between pressure changes and keratinocyte proliferation by determining whether keratinocytes exposed to altered mechanical pressures would proliferate at different rates compared to control cells not subjected to pressure changes. Tissue culture flasks of human keratinocytes plated at an approximate density of 15,000 cells/cm(2) undergoing an intermittent cyclic pressure of 362 mm Hg at a frequency of 2.28 or 5.16 cycles/min (0.038 or 0.086 Hz) for 8 h were compared to control flasks grown at ambient room pressure. An in-line pressure transducer was used to monitor and adjust pressure within the cell chambers, using a solenoid valve. A thymidine incorporation assay assessed the amount of cell proliferation in each set of experiments. Differences in proliferation between keratinocytes subjected to cyclic pressure changes and control cells were found to be statistically significant (p < 0.05) in 4 out of 5 proliferation assays. Also, a higher frequency of pressure changes consistently generated a reduced proliferation rate compared to that seen in cells exposed to a lower frequency of pressure changes. These data indicate that keratinocytes undergoing intermittent pressure changes exhibit decreased proliferation rates compared to controls. Furthermore, an increased frequency rate seems to have a greater effect on proliferation than low-frequency rate pressure changes, suggesting that the stress caused by frequently changed pressure may play a greater role in reducing keratinocyte proliferation than the actual magnitude of load applied to the cells. Our results support the current treatment protocol of reducing speed and duration of walking on the site of the wound to promote healing of foot ulcers. (c) 2007 S. Karger AG, Basel.

Estradiol and corticosterone stimulate the proliferation of a GH cell line, MtT/S: Proliferation of growth hormone cells.

PubMed

Nogami, Haruo; Hiraoka, Yoshiki; Aiso, Sadakazu

2016-08-01

Estrogens are known as a potent growth-stimulator of the anterior pituitary cells such as prolactin cells and somatomammotroph cell lines, while glucocorticoids often inhibit cellular proliferation in the pituitary gland as well as in the extra-pituitary tissues. In this study, the involvement of these steroid hormones in the regulation of proliferation was examined in the MtT/S cells, secreting growth hormone (GH). Effects of estrogens and glucocorticoids were examined in MtT/S cells grown in the medium containing dextran-coated charcoal treated serum. The relative cell density after culture was estimated by the Cell Titer-Glo Luminescent Cell Viability Assay System, and the proliferation rate was determined by the BrdU incorporation method. The mRNA levels were determined by real-time PCR. Estradiol and the specific agonist for both estrogen receptor (ER) α and ERβ stimulated MtT/S growth at a dose dependent manner. The membrane impermeable estrogen, 17β-estradiol-bovine serum albumin conjugate also stimulated the MtT/S proliferation. The effects of all estrogens were inhibited by an estrogen receptor antagonist, ICI182780. Corticosterone stimulated the proliferation of MtT/S cells at doses lower than 10nM without stimulating GH gene transcription, whereas it did not change the proliferation rate at 1μM. The effects of corticosterone were inhibited by glucocorticoid receptor inhibitor, RU486, but not by the mineralocorticoid receptor antagonist, spironolactone. Both estrogens and glucocorticoids were found to stimulate the proliferation of MtT/S, increasing the mRNA expression of cyclins D1, D3, and E. The results suggest that estrogens and glucocorticoids may be involved in the mechanisms responsible for the proliferation of GH cells in the course of pituitary development, to maintain the population of GH cells in the adult pituitary gland, and also in the promotion of GH cell tumors. Copyright © 2016 Elsevier Ltd. All rights reserved.

RNA sequencing-based cell proliferation analysis across 19 cancers identifies a subset of proliferation-informative cancers with a common survival signature.

PubMed

Ramaker, Ryne C; Lasseigne, Brittany N; Hardigan, Andrew A; Palacio, Laura; Gunther, David S; Myers, Richard M; Cooper, Sara J

2017-06-13

Despite advances in cancer diagnosis and treatment strategies, robust prognostic signatures remain elusive in most cancers. Cell proliferation has long been recognized as a prognostic marker in cancer, but the generation of comprehensive, publicly available datasets allows examination of the links between cell proliferation and cancer characteristics such as mutation rate, stage, and patient outcomes. Here we explore the role of cell proliferation across 19 cancers (n = 6,581 patients) by using tissue-based RNA sequencing data from The Cancer Genome Atlas Project and calculating a 'proliferative index' derived from gene expression associated with Proliferating Cell Nuclear Antigen (PCNA) levels. This proliferative index is significantly associated with patient survival (Cox, p-value < 0.05) in 7 of 19 cancers, which we have defined as "proliferation-informative cancers" (PICs). In PICs, the proliferative index is strongly correlated with tumor stage and nodal invasion. PICs demonstrate reduced baseline expression of proliferation machinery relative to non-PICs. Additionally, we find the proliferative index is significantly associated with gross somatic mutation burden (Spearman, p = 1.76 x 10-23) as well as with mutations in individual driver genes. This analysis provides a comprehensive characterization of tumor proliferation indices and their association with disease progression and prognosis in multiple cancer types and highlights specific cancers that may be particularly susceptible to improved targeting of this classic cancer hallmark.

Cell proliferation assessment in oncology.

PubMed

Hofstädter, F; Knüchel, R; Rüschoff, J

1995-01-01

A review of the current knowledge on cell cycle control and the techniques used to assess proliferation of normal and neoplastic cells was the focus of a workshop in Regensburg, Germany, held under the joint auspices of the Graduiertenkolleg: Therapieforschung Onkologie and the Committee on AgNOR Quantification. An overview of the recently discovered group of cyclins and their specific kinases, and of other proliferation-associated antigens, such as Ki67, PCNA and topoiseromase II alpha, was given. The topics continued with a reappraisal of modern imaging and flow-cytometric techniques. An update of the relation of AgNORs to cellular proliferation and differentiation was the link to presentations on clinical data, problems and strategies for standardization, as well as guidelines to establish the prognostic value of marker molecules. These lectures were supported by posters. Bringing together researchers from life sciences, technically oriented workers, pathologists, and clinicians resulted in a lively and constructive discussion, which is briefly summarized in the Concluding remarks.

Calcium signaling and cell proliferation.

PubMed

Pinto, Mauro Cunha Xavier; Kihara, Alexandre Hiroaki; Goulart, Vânia A M; Tonelli, Fernanda M P; Gomes, Katia N; Ulrich, Henning; Resende, Rodrigo R

2015-11-01

Cell proliferation is orchestrated through diverse proteins related to calcium (Ca(2+)) signaling inside the cell. Cellular Ca(2+) influx that occurs first by various mechanisms at the plasma membrane, is then followed by absorption of Ca(2+) ions by mitochondria and endoplasmic reticulum, and, finally, there is a connection of calcium stores to the nucleus. Experimental evidence indicates that the fluctuation of Ca(2+) from the endoplasmic reticulum provides a pivotal and physiological role for cell proliferation. Ca(2+) depletion in the endoplasmatic reticulum triggers Ca(2+) influx across the plasma membrane in an phenomenon called store-operated calcium entries (SOCEs). SOCE is activated through a complex interplay between a Ca(2+) sensor, denominated STIM, localized in the endoplasmic reticulum and a Ca(2+) channel at the cell membrane, denominated Orai. The interplay between STIM and Orai proteins with cell membrane receptors and their role in cell proliferation is discussed in this review. Copyright © 2015 Elsevier Inc. All rights reserved.

Inhibition of Smooth Muscle Proliferation by Urea-Based Alkanoic Acids via Peroxisome Proliferator-Activated Receptor α–Dependent Repression of Cyclin D1

PubMed Central

Ng, Valerie Y.; Morisseau, Christophe; Falck, John R.; Hammock, Bruce D.; Kroetz, Deanna L.

2007-01-01

Objective Proliferation of smooth muscle cells is implicated in cardiovascular complications. Previously, a urea-based soluble epoxide hydrolase inhibitor was shown to attenuate smooth muscle cell proliferation. We examined the possibility that urea-based alkanoic acids activate the nuclear receptor peroxisome proliferator-activated receptor α (PPARα) and the role of PPARα in smooth muscle cell proliferation. Methods and Results Alkanoic acids transactivated PPARα, induced binding of PPARα to its response element, and significantly induced the expression of PPARα-responsive genes, showing their function as PPARα agonists. Furthermore, the alkanoic acids attenuated platelet-derived growth factor–induced smooth muscle cell proliferation via repression of cyclin D1 expression. Using small interfering RNA to decrease endogenous PPARα expression, it was determined that PPARα was partially involved in the cyclin D1 repression. The antiproliferative effects of alkanoic acids may also be attributed to their inhibitory effects on soluble epoxide hydrolase, because epoxyeicosatrienoic acids alone inhibited smooth muscle cell proliferation. Conclusions These results show that attenuation of smooth muscle cell proliferation by urea-based alkanoic acids is mediated, in part, by the activation of PPARα. These acids may be useful for designing therapeutics to treat diseases characterized by excessive smooth muscle cell proliferation. PMID:16917105

Cell proliferation of Paramecium tetraurelia under simulated microgravity

NASA Astrophysics Data System (ADS)

Sawai, S.; Mogami, Y.; Baba, S. A.

Paramecium is known to proliferate faster under microgravity in space and slower under hypergravity Experiments using axenic culture medium have demonstrated that the hypergravity affected directly on the proliferation of Paramecium itself Kato et al 2003 In order to assess the mechanisms underlying the physiological effects of gravity on cell proliferation Paramecium tetraurelia was grown under simulated microgravity performed by clinorotation and the time course of the proliferation was investigated in detail on the basis of the logistic analysis P tetraurelia was cultivated in a closed chamber in which cells were confined without air babbles reducing the shear stresses and turbulence under the rotation The chamber is made of quartz and silicone rubber film the former is for the optically-flat walls for the measurement of cell density by means of a non-invasive laser optical-slice method and the latter for gas exchange Because the closed chamber has an inner dimension of 3 times 3 times 60 mm Paramecium does not accumulate at the top of the chamber despite its negative gravitactic behavior We measured the cell density at regular time intervals without breaking the configuration of the chamber and analyzed the proliferation parameters by fitting the data to a logistic equation Clinorotation had the effects of reducing the proliferation of P tetraurelia It reduced both the saturation cell density and the maximum proliferation rate although it had little effect on the

Early diagnosis and successful treatment of paraneoplastic melanocytic proliferation

PubMed Central

Jansen, Joyce C G; Van Calster, Joachim; Pulido, Jose S; Miles, Sarah L; Vile, Richard G; Van Bergen, Tine; Cassiman, Catherine; Spielberg, Leigh H; Leys, Anita M

2015-01-01

Background Paraneoplastic melanocytic proliferation (bilateral diffuse uveal melanocytic proliferation, BDUMP) is a rare but devastating disease that causes progressive visual loss in patients who usually have an occult malignancy. Visual loss occurs as a result of paraneoplastic changes in the uveal tissue. Methods In a masked fashion, the serum of two patients with BDUMP was evaluated for the presence of cultured melanocyte elongation and proliferation (CMEP) factor using cultured human melanocytes. We evaluated the efficacy of plasmapheresis as a treatment modality early in the disease in conjunction with radiation and chemotherapy. Results The serum of the first case patient was investigated after plasmapheresis and did not demonstrate proliferation of cultured human melanocytes. The serum of the second case was evaluated prior to treatment with plasmapheresis and did induce this proliferation. These findings are in accordance with the diminution of CMEP factor after plasmapheresis. Treatment with plasmapheresis managed to stabilise the ocular disease progression in both patients. Conclusions In the past, visual loss due to paraneoplastic melanocytic proliferation was considered progressive and irreversible. We treated two patients successfully with plasmapheresis and demonstrated a relation between CMEP factor in the serum of these patients and proliferation of cultured melanocytes. PMID:25908835

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.

Worldwide Report, Nuclear Development and Proliferation

DTIC Science & Technology

1984-06-07

A 201204 JPRS-TND-84-013 7 June 1984 Worldwide Report NUCLEAR DEVELOPMENT AND PROLIFERATION \\ y0& ^ KK0 %>$JJMXSTT JWRTF-Tnuyy...Publications Research Service, 1000 North Glebe Road, Arlington, Virginia 22201. JPRS-TND-84-013 7 June 1984 WORLDWIDE REPORT NUCLEAR DEVELOPMENT AND...But China by no means favors nuclear proliferation by helping other countries to develop nuclear weapons, he declared. China holds, he said, that

Wnt signaling regulates pancreatic β cell proliferation

PubMed Central

Rulifson, Ingrid C.; Karnik, Satyajit K.; Heiser, Patrick W.; ten Berge, Derk; Chen, Hainan; Gu, Xueying; Taketo, Makoto M.; Nusse, Roel; Hebrok, Matthias; Kim, Seung K.

2007-01-01

There is widespread interest in defining factors and mechanisms that stimulate proliferation of pancreatic islet cells. Wnt signaling is an important regulator of organ growth and cell fates, and genes encoding Wnt-signaling factors are expressed in the pancreas. However, it is unclear whether Wnt signaling regulates pancreatic islet proliferation and differentiation. Here we provide evidence that Wnt signaling stimulates islet β cell proliferation. The addition of purified Wnt3a protein to cultured β cells or islets promoted expression of Pitx2, a direct target of Wnt signaling, and Cyclin D2, an essential regulator of β cell cycle progression, and led to increased β cell proliferation in vitro. Conditional pancreatic β cell expression of activated β-catenin, a crucial Wnt signal transduction protein, produced similar phenotypes in vivo, leading to β cell expansion, increased insulin production and serum levels, and enhanced glucose handling. Conditional β cell expression of Axin, a potent negative regulator of Wnt signaling, led to reduced Pitx2 and Cyclin D2 expression by β cells, resulting in reduced neonatal β cell expansion and mass and impaired glucose tolerance. Thus, Wnt signaling is both necessary and sufficient for islet β cell proliferation, and our study provides previously unrecognized evidence of a mechanism governing endocrine pancreas growth and function. PMID:17404238

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.

Nuclear Energy, Nuclear Weapons Proliferation, and the Arms Race.

ERIC Educational Resources Information Center

Hollander, Jack, Ed.

A symposium was organized to reexamine the realities of vertical proliferation between the United States and the Soviet Union and to place into perspective the horizontal proliferation of nuclear weapons throughout the world, including the possible role of commercial nuclear power in facilitating proliferation. The four invited symposium…

Peroxisome proliferator-activated receptor gamma overexpression suppresses proliferation of human colon cancer cells

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

Tsukahara, Tamotsu, E-mail: ttamotsu@shinshu-u.ac.jp; Haniu, Hisao

2012-08-03

Highlights: Black-Right-Pointing-Pointer We examined the correlation between PPAR{gamma} expression and cell proliferation. Black-Right-Pointing-Pointer PPAR{gamma} overexpression reduces cell viability. Black-Right-Pointing-Pointer We show the synergistic effect of cell growth inhibition by a PPAR{gamma} agonist. -- Abstract: Peroxisome proliferator-activated receptor gamma (PPAR{gamma}) plays an important role in the differentiation of intestinal cells and tissues. Our previous reports indicate that PPAR{gamma} is expressed at considerable levels in human colon cancer cells. This suggests that PPAR{gamma} expression may be an important factor for cell growth regulation in colon cancer. In this study, we investigated PPAR{gamma} expression in 4 human colon cancer cell lines, HT-29, LOVO,more » DLD-1, and Caco-2. Real-time polymerase chain reaction (PCR) and Western blot analysis revealed that the relative levels of PPAR{gamma} mRNA and protein in these cells were in the order HT-29 > LOVO > Caco-2 > DLD-1. We also found that PPAR{gamma} overexpression promoted cell growth inhibition in PPAR{gamma} lower-expressing cell lines (Caco-2 and DLD-1), but not in higher-expressing cells (HT-29 and LOVO). We observed a correlation between the level of PPAR{gamma} expression and the cells' sensitivity for proliferation.« less

Sequencing of Seven Haloarchaeal Genomes Reveals Patterns of Genomic Flux

PubMed Central

Lynch, Erin A.; Langille, Morgan G. I.; Darling, Aaron; Wilbanks, Elizabeth G.; Haltiner, Caitlin; Shao, Katie S. Y.; Starr, Michael O.; Teiling, Clotilde; Harkins, Timothy T.; Edwards, Robert A.; Eisen, Jonathan A.; Facciotti, Marc T.

2012-01-01

We report the sequencing of seven genomes from two haloarchaeal genera, Haloferax and Haloarcula. Ease of cultivation and the existence of well-developed genetic and biochemical tools for several diverse haloarchaeal species make haloarchaea a model group for the study of archaeal biology. The unique physiological properties of these organisms also make them good candidates for novel enzyme discovery for biotechnological applications. Seven genomes were sequenced to ∼20×coverage and assembled to an average of 50 contigs (range 5 scaffolds - 168 contigs). Comparisons of protein-coding gene compliments revealed large-scale differences in COG functional group enrichment between these genera. Analysis of genes encoding machinery for DNA metabolism reveals genera-specific expansions of the general transcription factor TATA binding protein as well as a history of extensive duplication and horizontal transfer of the proliferating cell nuclear antigen. Insights gained from this study emphasize the importance of haloarchaea for investigation of archaeal biology. PMID:22848480

Cardiac resident macrophages are involved in hypoxia-induced postnatal cardiomyocyte proliferation

PubMed Central

Liu, Bo; Zhang, Hua-Gang; Zhu, Yun; Jiang, Yun-Han; Luo, Gui-Ping; Tang, Fu-Qin; Jian, Zhao; Xiao, Ying-Bin

2017-01-01

Induction of cardiomyocyte proliferation, the most promising approach to reverse myocardial attrition, has been gaining importance as a therapy for cardiovascular disease. Hypoxia and macrophages were previously independently reported to promote cardiomyocyte proliferation in mice. However, whether hypoxia promotes cardiomyocyte proliferation in humans, and the association between hypoxia and macrophages in cardiomyocyte proliferation, have not to the best of our knowledge been previously investigated. The present study investigated the cardiomyocyte proliferation in 22 acyanotic and 29 cyanotic patients. Cardiomyocyte proliferation in a hypoxic mouse model (15% O2) was subsequently performed and the macrophage subsets were analyzed. A C-C chemokine receptor type 2 (CCR2) inhibitor was used to increase the number of resident macrophages in order to investigate the effect of macrophages on cardiomyocyte proliferation. The results demonstrated that cardiomyocyte proliferation in the cyanotic infant group was significantly increased compared with the acyanotic infant group and the hypoxia-treated C57BL/6J neonates confirmed the hypoxia-induced cardiomyocyte proliferation. However, hypoxia did not induce the proliferation of isolated cardiomyocytes. Notably, hypoxia treatment increased the number of cardiac resident macrophages in neonate hearts. Furthermore, increasing the number of resident macrophages significantly enhanced cardiomyocyte proliferation. In conclusion, postnatal hypoxia promoted cardiomyocyte proliferation in humans and animals, and cardiac resident macrophages may be involved in this process. Therefore, this novel mechanism may provide a promising strategy for cardiovascular disease treatment. PMID:28393210

Proliferation of nuclear weapons: opportunities for control and abolition.

PubMed

Sidel, Victor W; Levy, Barry S

2007-09-01

Nuclear weapons pose a particularly destructive threat. Prevention of the proliferation and use of nuclear weapons is urgently important to public health. "Horizontal" proliferation refers to nation-states or nonstate entities that do not have, but are acquiring, nuclear weapons or developing the capability and materials for producing them. "Vertical" proliferation refers to nation-states that do possess nuclear weapons and are increasing their stockpiles of these weapons, improving the technical sophistication or reliability of their weapons, or developing new weapons. Because nation-states or other entities that wish to use or threaten to use nuclear weapons need methods for delivering those weapons, proliferation of delivery mechanisms must also be prevented. Controlling proliferation--and ultimately abolishing nuclear weapons--involves national governments, intergovernmental organizations, nongovernmental and professional organizations, and society at large.

Nuclear Proliferation Technology Trends Analysis

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

Zentner, Michael D.; Coles, Garill A.; Talbert, Robert J.

2005-10-04

A process is underway to develop mature, integrated methodologies to address nonproliferation issues. A variety of methodologies (both qualitative and quantitative) are being considered. All have one thing in common, a need for a consistent set of proliferation related data that can be used as a basis for application. One approach to providing a basis for predicting and evaluating future proliferation events is to understand past proliferation events, that is, the different paths that have actually been taken to acquire or attempt to acquire special nuclear material. In order to provide this information, this report describing previous material acquisition activitiesmore » (obtained from open source material) has been prepared. This report describes how, based on an evaluation of historical trends in nuclear technology development, conclusions can be reached concerning: (1) The length of time it takes to acquire a technology; (2) The length of time it takes for production of special nuclear material to begin; and (3) The type of approaches taken for acquiring the technology. In addition to examining time constants, the report is intended to provide information that could be used to support the use of the different non-proliferation analysis methodologies. Accordingly, each section includes: (1) Technology description; (2) Technology origin; (3) Basic theory; (4) Important components/materials; (5) Technology development; (6) Technological difficulties involved in use; (7) Changes/improvements in technology; (8) Countries that have used/attempted to use the technology; (9) Technology Information; (10) Acquisition approaches; (11) Time constants for technology development; and (12) Required Concurrent Technologies.« less

Mullerian papilloma-like proliferation arising in cystic pelvic endosalpingiosis.

PubMed

McCluggage, W Glenn; O'Rourke, Declan; McElhenney, Clodagh; Crooks, Michael

2002-09-01

This report describes an unusual epithelial proliferation occurring in pelvic cystic endosalpingiosis. A cyst mass lined by a layer of ciliated epithelial cells involved the posterior surface of the cervix and vagina. The epithelial proliferation within the wall resembled a mullerian papilloma with fibrous and fibrovascular cores lined by bland cuboidal epithelial cells. Other areas had a microglandular growth pattern resembling cervical microglandular hyperplasia, and focally there was a solid growth pattern. Foci of typical endosalpingiosis involved the surface of both ovaries and pelvic soft tissues. The cystic lesion recurred after partial cystectomy and drainage and was followed up radiologically and with periodic fine-needle aspiration. Part of the wall of the cyst removed 11 years after the original surgery showed an identical epithelial proliferation. MIB1 staining showed a proliferation index of less than 5%, contrasting with the higher proliferation index of a typical serous borderline tumor. The differential diagnosis is discussed. As far as we are aware, this is the first report of such a benign epithelial proliferation involving cystic endosalpingiosis. Copyright 2002, Elsevier Science (USA). All rights reserved.

T-kininogen induces endothelial cell proliferation.

PubMed

Pérez, Viviana; Leiva-Salcedo, Elías; Acuña-Castillo, Claudio; Aravena, Mauricio; Gómez, Christian; Sabaj, Valeria; Colombo, Alicia; Nishimura, Sumiyo; Pérez, Claudio; Walter, Robin; Sierra, Felipe

2006-03-01

Basal proliferation of endothelial cells increases with age, and this might play a role in the etiology of age-related vascular diseases, as well as angiogenesis. Serum kininogen levels increase during aging in rats and humans, and T-kininogen (T-KG) can affect proliferative homeostasis in several cell models. Both kinins and kininogens have been shown previously to be angiogenic through activation of endothelial cell proliferation, and here we show that exposure of endothelial cells to T-KG results in vigorous cell proliferation, accompanied by ERK/AKT activation. In our experiments, the proliferative response requires B1 and B2 kinin receptors, even though kinins are not released from the precursor. We hypothesize that the age-related increase in T-KG could play a significant role in the age-related dysregulation of vascular physiology and function.

The role of peroxisome proliferator-activated receptor-{beta}/{delta} in epidermal growth factor-induced HaCaT cell proliferation

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

Liang Pengfei; Jiang Bimei; Yang Xinghua

2008-10-15

Epidermal growth factor (EGF) has been shown to be a potent mitogen for epidermal cells both in vitro and in vivo, thus contributing to the development of an organism. It has recently become clear that peroxisome proliferator-activated receptor-{beta}/{delta} (PPAR{beta}/{delta}) expression and activation is involved in the cell proliferation. However, little is known about the role of PPAR{beta}/{delta} in EGF-induced proliferation of HaCaT keratinocytes. In this study, HaCaT cells were cultured in the presence and absence of EGF and we identified that EGF induced an increase of PPAR{beta}/{delta} mRNA and protein level expression in time-dependent and dose-dependent manner, and AG1487, anmore » EGF receptor (EGFR) special inhibitor, caused attenuation of PPAR{beta}/{delta} protein expression. Electrophoretic mobility shift assay (EMSA) revealed that EGF significantly increased PPAR{beta}/{delta} binding activity in HaCaT keratinocytes. Antisense phosphorothioate oligonucleotides (asODNs) against PPAR{beta}/{delta} caused selectively inhibition of PPAR{beta}/{delta} protein content induced by EGF and significantly attenuated EGF-mediated cell proliferation. Treatment of the cells with L165041, a specific synthetic ligand for PPAR{beta}/{delta}, significantly enhanced EGF-mediated cell proliferation. Finally, c-Jun ablation inhibited PPAR{beta}/{delta} up-regulation induced by EGF, and chromatin immunoprecipitation (ChIP) showed that c-Jun bound to the PPAR{beta}/{delta} promoter and the binding increased in EGF-stimulated cells. These results demonstrate that EGF induces PPAR{beta}/{delta} expression in a c-Jun-dependent manner and PPAR{beta}/{delta} plays a vital role in EGF-stimulated proliferation of HaCaT cells.« less

Early diagnosis and successful treatment of paraneoplastic melanocytic proliferation.

PubMed

Jansen, Joyce C G; Van Calster, Joachim; Pulido, Jose S; Miles, Sarah L; Vile, Richard G; Van Bergen, Tine; Cassiman, Catherine; Spielberg, Leigh H; Leys, Anita M

2015-07-01

Paraneoplastic melanocytic proliferation (bilateral diffuse uveal melanocytic proliferation, BDUMP) is a rare but devastating disease that causes progressive visual loss in patients who usually have an occult malignancy. Visual loss occurs as a result of paraneoplastic changes in the uveal tissue. In a masked fashion, the serum of two patients with BDUMP was evaluated for the presence of cultured melanocyte elongation and proliferation (CMEP) factor using cultured human melanocytes. We evaluated the efficacy of plasmapheresis as a treatment modality early in the disease in conjunction with radiation and chemotherapy. The serum of the first case patient was investigated after plasmapheresis and did not demonstrate proliferation of cultured human melanocytes. The serum of the second case was evaluated prior to treatment with plasmapheresis and did induce this proliferation. These findings are in accordance with the diminution of CMEP factor after plasmapheresis. Treatment with plasmapheresis managed to stabilise the ocular disease progression in both patients. In the past, visual loss due to paraneoplastic melanocytic proliferation was considered progressive and irreversible. We treated two patients successfully with plasmapheresis and demonstrated a relation between CMEP factor in the serum of these patients and proliferation of cultured melanocytes. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Worldwide Report, Nuclear Development and Proliferation

DTIC Science & Technology

1984-07-02

delegate welcomed the inclusion of a new item-disarmament and development -on the commission’s agenda. Miss Kunadi said the catalytic effects of arms...249199 JPRS-TND-84-016 2 July 1984 — """ , f L ~ tibiae iel<M99; Worldwide Report NUCLEAR DEVELOPMENT AND PROLIFERATION mom m FBIS...Arlington, Virginia 22201. JPRS-TND-84- ■016 2 July 1984 WORLDWIDE REPORT NUCLEAR DEVELOPMENT AND PROLIFERATION CONTENTS ASIA PEOPLE ’S REPUBLIC OF

Benzene and its metabolite decreases cell proliferation via LncRNA-OBFC2A-mediated anti-proliferation effect involving NOTCH1 and KLF15

PubMed Central

Sun, Pengling; Wang, Jing; Guo, Xiaoli; Chen, Yujiao; Xing, Caihong; Gao, Ai

2017-01-01

LncRNA has been considered to play a crucial role in the progression of several diseases by affecting cell proliferation. However, its role in benzene toxicity remains unclear. Our study showed that the expression of lncRNA-OBFC2A increased accompanied with the change of cell proliferation related-genes in benzene-exposed workers. In vitro experiments, 1,4-Benzoquinone dose-dependently inhibited cell proliferation and simultaneously caused the decrease of NOTCH1 expression and the increase of KLF15 in AHH-1 cell lines. Meanwhile, 1, 4-Benzoquinone obviously increased the expression of lncRNA-OBFC2A, which was consistent with our previous population results. Therefore, we propose that lncRNA-OBFC2A is involved in benzene toxicity by regulating cell proliferation. Further, we successfully constructed a lentivirus model of interfering the expression of lncRNA-OBFC2A. After interfering lncRNA-OBFC2A, the cell proliferation inhibition and the expression of NOTCH1 and KLF15 induced by 1, 4-Benzoquinone were reversed. Subsequently, RNA fluorescence in situ Hybridization assay showed that lncRNA-OBFC2A was located in cell nuclei. These results suggest that benzene and its metabolite decreases cell proliferation via LncRNA-OBFC2A-mediated anti-proliferation effect involving NOTCH1 and KLF15. LncRNA-OBFC2A can be a potential biomarker for benzene toxicity. PMID:28388563

Benzene and its metabolite decreases cell proliferation via LncRNA-OBFC2A-mediated anti-proliferation effect involving NOTCH1 and KLF15.

PubMed

Sun, Pengling; Wang, Jing; Guo, Xiaoli; Chen, Yujiao; Xing, Caihong; Gao, Ai

2017-06-20

LncRNA has been considered to play a crucial role in the progression of several diseases by affecting cell proliferation. However, its role in benzene toxicity remains unclear. Our study showed that the expression of lncRNA-OBFC2A increased accompanied with the change of cell proliferation related-genes in benzene-exposed workers. In vitro experiments, 1,4-Benzoquinone dose-dependently inhibited cell proliferation and simultaneously caused the decrease of NOTCH1 expression and the increase of KLF15 in AHH-1 cell lines. Meanwhile, 1, 4-Benzoquinone obviously increased the expression of lncRNA-OBFC2A, which was consistent with our previous population results. Therefore, we propose that lncRNA-OBFC2A is involved in benzene toxicity by regulating cell proliferation. Further, we successfully constructed a lentivirus model of interfering the expression of lncRNA-OBFC2A. After interfering lncRNA-OBFC2A, the cell proliferation inhibition and the expression of NOTCH1 and KLF15 induced by 1, 4-Benzoquinone were reversed. Subsequently, RNA fluorescence in situ Hybridization assay showed that lncRNA-OBFC2A was located in cell nuclei. These results suggest that benzene and its metabolite decreases cell proliferation via LncRNA-OBFC2A-mediated anti-proliferation effect involving NOTCH1 and KLF15. LncRNA-OBFC2A can be a potential biomarker for benzene toxicity.

EDA-containing fibronectin increases proliferation of embryonic stem cells.

PubMed

Losino, Noelia; Waisman, Ariel; Solari, Claudia; Luzzani, Carlos; Espinosa, Darío Fernández; Sassone, Alina; Muro, Andrés F; Miriuka, Santiago; Sevlever, Gustavo; Barañao, Lino; Guberman, Alejandra

2013-01-01

Embryonic stem cells (ESC) need a set of specific factors to be propagated. They can also grow in conditioned medium (CM) derived from a bovine granulosa cell line BGC (BGC-CM), a medium that not only preserves their main features but also increases ESC´s proliferation rate. The mitogenic properties of this medium were previously reported, ascribing this effect to an alternative spliced generated fibronectin isoform that contains the extra domain A (FN EDA(+)). Here, we investigated if the FN EDA(+) isoform increased proliferation of mouse and human ES cells. We analyzed cell proliferation using conditioned media produced by different mouse embryonic fibroblast (MEF) lines genetically engineered to express FN constitutively including or excluding the EDA domain (FN EDA(-)), and in media supplemented with recombinant peptides containing or not the EDA. We found that the presence of EDA in the medium increased mouse and human ESC's proliferation rate. Here we showed for the first time that this FN isoform enhances ESC's proliferation. These findings suggest a possible conserved behavior for regulation of ES cells proliferation by this FN isoform and could contribute to improve their culturing conditions both for research and cell therapy.

EDA-Containing Fibronectin Increases Proliferation of Embryonic Stem Cells

PubMed Central

Losino, Noelia; Waisman, Ariel; Solari, Claudia; Luzzani, Carlos; Espinosa, Darío Fernández; Sassone, Alina; Muro, Andrés F.; Miriuka, Santiago; Sevlever, Gustavo; Barañao, Lino; Guberman, Alejandra

2013-01-01

Embryonic stem cells (ESC) need a set of specific factors to be propagated. They can also grow in conditioned medium (CM) derived from a bovine granulosa cell line BGC (BGC-CM), a medium that not only preserves their main features but also increases ESC´s proliferation rate. The mitogenic properties of this medium were previously reported, ascribing this effect to an alternative spliced generated fibronectin isoform that contains the extra domain A (FN EDA+). Here, we investigated if the FN EDA+ isoform increased proliferation of mouse and human ES cells. We analyzed cell proliferation using conditioned media produced by different mouse embryonic fibroblast (MEF) lines genetically engineered to express FN constitutively including or excluding the EDA domain (FN EDA-), and in media supplemented with recombinant peptides containing or not the EDA. We found that the presence of EDA in the medium increased mouse and human ESC’s proliferation rate. Here we showed for the first time that this FN isoform enhances ESC’s proliferation. These findings suggest a possible conserved behavior for regulation of ES cells proliferation by this FN isoform and could contribute to improve their culturing conditions both for research and cell therapy. PMID:24244705

Explaining weapons proliferation: Going beyond the security dilemma

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

Rattray, G.J.

1994-07-01

Most analyses addressing the subject of why states choose to proliferate focus on external motivations, particularly the security dilemma, facing a country`s leaders. This paper concludes that, other factors, such as prestige, regime type and stability, and economic status, can have impact in determining proliferation outcomes. In the case of Newly Independent States of the former Soviet Union (NIS), the domestic problems generated by internal conflicts, arms remaining from the Cold War, excess defense industrial capacity, economic difficulties and the breakdown of central authority resulting in a loss of border control and corruption have all made the NIS an extremelymore » fertile ground for weapons proliferation. A more positive `rollback` situation has emerged in Latin America where both Argentina and Brazil have seemingly decided to forgo the acquisition of nuclear weapons and ballistic missiles. The US must understand the `strategic personality` of each potential proliferation. Not all state behavior can be explained in terms of the security dilemma. One must also keep in mind the complexity of possible motivations. Economic and technological assistance and cooperative efforts at institution-building hold great potential to combating proliferation.« less

OPC-12759 increases proliferation of cultured rat conjunctival goblet cells.

PubMed

Ríos, José D; Shatos, Marie; Urashima, Hiroki; Tran, Hao; Dartt, Darlene A

2006-06-01

To determine if the gastroprotective drug OPC-12759 increased proliferation of rat conjunctival goblet cells in culture. Cultured goblet cells were incubated with 10(-12) to 10(-8) M OPC-12759 for 1 to 7 days. Fetal bovine serum (FBS) was used as a positive control. Cell proliferation was determined by a MTT [3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide] colorimetric assay and by immunohistochemical staining with anti-Ki-67, a marker of cell division. Goblet cells were identified by double-labeling with anti-Ki-67, a marker of cell division, and Ulex europaeus agglutinin I lectin, anti-MUC5AC and anticytokeratin 7. Stratified squamous cells were identified by using Griffonia (Bandeiraea) simplicifolia lectin and anticytokeratin 4 antibody. As determined by MTT conversion to formazan, OPC-12579 at 10(-11) M induced an almost 2-fold increase in goblet cell proliferation on Days 1 and 3 of incubation but not on Days 5 and 7. The FBS at 10% increased cell proliferation by 2- to 3-fold at each time point. Daily replenishment of OPC-12579 for 3 consecutive days induced cell proliferation at all concentrations. Proliferation as determined by the number of Ki-67 positive cells increased by 4- and 3-fold at Days 1 and 3, respectively with addition of 10(-11) M OPC-12579. The FBS at 10% induced a 10-fold increase in goblet cell proliferation on Days 1, 3, and 5. Colocalization of Ulex europaeus agglutinin I, MUC5AC and anticytokeratin 7 with Ki-67 indicated that proliferating cells were goblet cells. Proliferating cells were negative for the nongoblet cell markers Bandeiraea lectin and anticytokeratin 4. The OPC-12759 stimulates proliferation of conjunctival goblet cells in primary culture.

Pancreatic β-cell proliferation in obesity.

PubMed

Linnemann, Amelia K; Baan, Mieke; Davis, Dawn Belt

2014-05-01

Because obesity rates have increased dramatically over the past 3 decades, type 2 diabetes has become increasingly prevalent as well. Type 2 diabetes is associated with decreased pancreatic β-cell mass and function, resulting in inadequate insulin production. Conversely, in nondiabetic obesity, an expansion in β-cell mass occurs to provide sufficient insulin and to prevent hyperglycemia. This expansion is at least in part due to β-cell proliferation. This review focuses on the mechanisms regulating obesity-induced β-cell proliferation in humans and mice. Many factors have potential roles in the regulation of obesity-driven β-cell proliferation, including nutrients, insulin, incretins, hepatocyte growth factor, and recently identified liver-derived secreted factors. Much is still unknown about the regulation of β-cell replication, especially in humans. The extracellular signals that activate proliferative pathways in obesity, the relative importance of each of these pathways, and the extent of cross-talk between these pathways are important areas of future study. © 2014 American Society for Nutrition.

Myopericytoma proliferating in an unusual anastomosing multinodular fashion.

PubMed

Inoue, Takuya; Misago, Noriyuki; Asami, Akihiko; Tokunaga, Osamu; Narisawa, Yutaka

2016-05-01

We herein describe a case of myopericytoma that proliferated in an unusual fashion. Myopericytoma is described as a group of rare, benign, dermal or subcutaneous tumors that are characterized histologically by a striking, concentric, perivascular proliferation of spindle cells and showing apparent differentiation towards perivascular myoid cells. Myopericytoma forms a morphological continuum with myofibroma/myofibromatosis, glomus tumor and angioleiomyoma. The patient was a 64-year-old woman who demonstrated a recurrent ulcer on an atrophic plaque on her left shin. A histopathological examination of the plaque demonstrated that tumor cells proliferated in an anastomosing multinodular fashion along the vessels in the dermis and subcutaneous tissue. In those nodules, there were numerous, small, concentric proliferations of myoid-appearing spindle cells around small vascular lumina. The present case is an unusual example of myopericytoma, manifesting in a characteristic anastomosing, multinodular, infiltrating fashion. © 2015 Japanese Dermatological Association.

Monitoring Technology Proliferation: An Open Source Methodology For Generating Proliferation Intelligence

DTIC Science & Technology

1993-12-01

72 D. MINES AND THE MILITARY-TECHNOLOGICAL REVOLUTION ...................................... 74 E. CUSTOMIZING THE TDD PROLIFERATION MARKET M...Data Storage & Peripherals - Systems Managmnt Technologies 4. Passive Sensors - Sensors and Signal Processing 5. Photonics - Electronic and...a reproducible procedure to allow customization of the model, provides the "guts" of the method. 18 Third, because they are not optimized for

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

Utility of Social Modeling for Proliferation Assessment - Preliminary Assessment

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

Coles, Garill A.; Gastelum, Zoe N.; Brothers, Alan J.

2009-06-01

This Preliminary Assessment draft report will present the results of a literature search and preliminary assessment of the body of research, analysis methods, models and data deemed to be relevant to the Utility of Social Modeling for Proliferation Assessment research. This report will provide: 1) a description of the problem space and the kinds of information pertinent to the problem space, 2) a discussion of key relevant or representative literature, 3) a discussion of models and modeling approaches judged to be potentially useful to the research, and 4) the next steps of this research that will be pursued based onmore » this preliminary assessment. This draft report represents a technical deliverable for the NA-22 Simulations, Algorithms, and Modeling (SAM) program. Specifically this draft report is the Task 1 deliverable for project PL09-UtilSocial-PD06, Utility of Social Modeling for Proliferation Assessment. This project investigates non-traditional use of social and cultural information to improve nuclear proliferation assessment, including nonproliferation assessment, proliferation resistance assessments, safeguards assessments and other related studies. These assessments often use and create technical information about the State’s posture towards proliferation, the vulnerability of a nuclear energy system to an undesired event, and the effectiveness of safeguards. This project will find and fuse social and technical information by explicitly considering the role of cultural, social and behavioral factors relevant to proliferation. The aim of this research is to describe and demonstrate if and how social science modeling has utility in proliferation assessment.« less

Blue light inhibits proliferation of melanoma cells

NASA Astrophysics Data System (ADS)

Becker, Anja; Distler, Elisabeth; Klapczynski, Anna; Arpino, Fabiola; Kuch, Natalia; Simon-Keller, Katja; Sticht, Carsten; van Abeelen, Frank A.; Gretz, Norbert; Oversluizen, Gerrit

2016-03-01

Photobiomodulation with blue light is used for several treatment paradigms such as neonatal jaundice, psoriasis and back pain. However, little is known about possible side effects concerning melanoma cells in the skin. The aim of this study was to assess the safety of blue LED irradiation with respect to proliferation of melanoma cells. For that purpose we used the human malignant melanoma cell line SK-MEL28. Cell proliferation was decreased in blue light irradiated cells where the effect size depended on light irradiation dosage. Furthermore, with a repeated irradiation of the melanoma cells on two consecutive days the effect could be intensified. Fluorescence-activated cell sorting with Annexin V and Propidium iodide labeling did not show a higher number of dead cells after blue light irradiation compared to non-irradiated cells. Gene expression analysis revealed down-regulated genes in pathways connected to anti-inflammatory response, like B cell signaling and phagosome. Most prominent pathways with up-regulation of genes were cytochrome P450, steroid hormone biosynthesis. Furthermore, even though cells showed a decrease in proliferation, genes connected to the cell cycle were up-regulated after 24h. This result is concordant with XTT test 48h after irradiation, where irradiated cells showed the same proliferation as the no light negative control. In summary, proliferation of melanoma cells can be decreased using blue light irradiation. Nevertheless, the gene expression analysis has to be further evaluated and more studies, such as in-vivo experiments, are warranted to further assess the safety of blue light treatment.

Hippocampal cell proliferation regulation by repeated stress and antidepressants.

PubMed

Chen, Hu; Pandey, Ghanshyam N; Dwivedi, Yogesh

2006-06-26

A recent hypothesis suggests reduced hippocampal neurogenesis in depression. Here, we examined cell proliferation in the dentate gyrus and the subventricular zone of rats given repeated stress, a paradigm that prolongs learned helplessness behavior, and whether antidepressants modulate the learned helplessness-associated altered cell proliferation. Decreased cell proliferation, number of clusters, and cells/cluster were noted in the dentate gyrus, but not in the subventricular zone, of learned helplessness rats. Both fluoxetine and desipramine reversed the learned helplessness behavior and increased the cell proliferation and the number of clusters in learned helplessness rats; only fluoxetine did so significantly. Both fluoxetine and desipramine significantly increased the number of cells/cluster. Our results suggest modified hippocampal neurogenesis in prolonged depression and in the mechanism of antidepressant action.

E2F mediates enhanced alternative polyadenylation in proliferation.

PubMed

Elkon, Ran; Drost, Jarno; van Haaften, Gijs; Jenal, Mathias; Schrier, Mariette; Oude Vrielink, Joachim A F; Agami, Reuven

2012-07-02

The majority of mammalian genes contain multiple poly(A) sites in their 3' UTRs. Alternative cleavage and polyadenylation are emerging as an important layer of gene regulation as they generate transcript isoforms that differ in their 3' UTRs, thereby modulating genes' response to 3' UTR-mediated regulation. Enhanced cleavage at 3' UTR proximal poly(A) sites resulting in global 3' UTR shortening was recently linked to proliferation and cancer. However, mechanisms that regulate this enhanced alternative polyadenylation are unknown. Here, we explored, on a transcriptome-wide scale, alternative polyadenylation events associated with cellular proliferation and neoplastic transformation. We applied a deep-sequencing technique for identification and quantification of poly(A) sites to two human cellular models, each examined under proliferative, arrested and transformed states. In both cell systems we observed global 3' UTR shortening associated with proliferation, a link that was markedly stronger than the association with transformation. Furthermore, we found that proliferation is also associated with enhanced cleavage at intronic poly(A) sites. Last, we found that the expression level of the set of genes that encode for 3'-end processing proteins is globally elevated in proliferation, and that E2F transcription factors contribute to this regulation. Our results comprehensively identify alternative polyadenylation events associated with cellular proliferation and transformation, and demonstrate that the enhanced alternative polyadenylation in proliferative conditions results not only in global 3' UTR shortening but also in enhanced premature cleavage in introns. Our results also indicate that E2F-mediated co-transcriptional regulation of 3'-end processing genes is one of the mechanisms that links enhanced alternative polyadenylation to proliferation.

E2F mediates enhanced alternative polyadenylation in proliferation

PubMed Central

2012-01-01

Background The majority of mammalian genes contain multiple poly(A) sites in their 3' UTRs. Alternative cleavage and polyadenylation are emerging as an important layer of gene regulation as they generate transcript isoforms that differ in their 3' UTRs, thereby modulating genes' response to 3' UTR-mediated regulation. Enhanced cleavage at 3' UTR proximal poly(A) sites resulting in global 3' UTR shortening was recently linked to proliferation and cancer. However, mechanisms that regulate this enhanced alternative polyadenylation are unknown. Results Here, we explored, on a transcriptome-wide scale, alternative polyadenylation events associated with cellular proliferation and neoplastic transformation. We applied a deep-sequencing technique for identification and quantification of poly(A) sites to two human cellular models, each examined under proliferative, arrested and transformed states. In both cell systems we observed global 3' UTR shortening associated with proliferation, a link that was markedly stronger than the association with transformation. Furthermore, we found that proliferation is also associated with enhanced cleavage at intronic poly(A) sites. Last, we found that the expression level of the set of genes that encode for 3'-end processing proteins is globally elevated in proliferation, and that E2F transcription factors contribute to this regulation. Conclusions Our results comprehensively identify alternative polyadenylation events associated with cellular proliferation and transformation, and demonstrate that the enhanced alternative polyadenylation in proliferative conditions results not only in global 3' UTR shortening but also in enhanced premature cleavage in introns. Our results also indicate that E2F-mediated co-transcriptional regulation of 3'-end processing genes is one of the mechanisms that links enhanced alternative polyadenylation to proliferation. PMID:22747694

Sphingosine-1-phosphate stimulates rat primary chondrocyte proliferation

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

Kim, Mi-Kyoung; Lee, Ha Young; Kwak, Jong-Young

2006-06-23

Rat primary chondrocytes express the sphingosine-1-phosphate (S1P) receptor, S1P{sub 2}, S1P{sub 3}, S1P{sub 4}, but not S1P{sub 1}. When chondrocytes were stimulated with S1P or phytosphingosine-1-phosphate (PhS1P, an S1P{sub 1}- and S1P{sub 4}-selective agonist), phospholipase C-mediated cytosolic calcium increase was dramatically induced. S1P and PhS1P also stimulated two kinds of mitogen-activated protein kinases, extracellular signal-regulated kinase (ERK) and p38 kinase in chondrocytes. In terms of the two phospholipids-mediated functional modulation of chondrocytes, S1P and PhS1P stimulated cellular proliferation. The two phospholipids-induced chondrocyte proliferations were almost completely blocked by PD98059 but not by SB203580, suggesting that ERK but not p38 kinasemore » is essentially required for the proliferation. Pertussis toxin almost completely inhibited the two phospholipids-induced cellular proliferation and ERK activation, indicating the crucial role of G{sub i} protein. This study demonstrates the physiological role of two important phospholipids (S1P and PhS1P) on the modulation of rat primary chondrocyte proliferation, and the crucial role played by ERK in the process.« less

Proliferation of Nuclear Weapons: Opportunities for Control and Abolition

PubMed Central

Sidel, Victor W.; Levy, Barry S.

2007-01-01

Nuclear weapons pose a particularly destructive threat. Prevention of the proliferation and use of nuclear weapons is urgently important to public health. “Horizontal” proliferation refers to nation-states or nonstate entities that do not have, but are acquiring, nuclear weapons or developing the capability and materials for producing them. “Vertical” proliferation refers to nation-states that do possess nuclear weapons and are increasing their stockpiles of these weapons, improving the technical sophistication or reliability of their weapons, or developing new weapons. Because nation-states or other entities that wish to use or threaten to use nuclear weapons need methods for delivering those weapons, proliferation of delivery mechanisms must also be prevented. Controlling proliferation—and ultimately abolishing nuclear weapons—involves national governments, intergovernmental organizations, nongovernmental and professional organizations, and society at large. PMID:17666690

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.

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

Estimation of Cell Proliferation Dynamics Using CFSE Data

PubMed Central

Banks, H.T.; Sutton, Karyn L.; Thompson, W. Clayton; Bocharov, Gennady; Roose, Dirk; Schenkel, Tim; Meyerhans, Andreas

2010-01-01

Advances in fluorescent labeling of cells as measured by flow cytometry have allowed for quantitative studies of proliferating populations of cells. The investigations (Luzyanina et al. in J. Math. Biol. 54:57–89, 2007; J. Math. Biol., 2009; Theor. Biol. Med. Model. 4:1–26, 2007) contain a mathematical model with fluorescence intensity as a structure variable to describe the evolution in time of proliferating cells labeled by carboxyfluorescein succinimidyl ester (CFSE). Here, this model and several extensions/modifications are discussed. Suggestions for improvements are presented and analyzed with respect to statistical significance for better agreement between model solutions and experimental data. These investigations suggest that the new decay/label loss and time dependent effective proliferation and death rates do indeed provide improved fits of the model to data. Statistical models for the observed variability/noise in the data are discussed with implications for uncertainty quantification. The resulting new cell dynamics model should prove useful in proliferation assay tracking and modeling, with numerous applications in the biomedical sciences. PMID:20195910

Cell proliferation of Paramecium tetraurelia on a slow rotating clinostat

NASA Astrophysics Data System (ADS)

Sawai, Satoe; Mogami, Yoshihiro; Baba, Shoji A.

Paramecium is known to proliferate faster under microgravity conditions, and slower under hypergravity. Experiments using axenic culture medium have demonstrated that hypergravity affected directly on the proliferation of Paramecium itself. In order to assess the mechanisms underlying the physiological effects of gravity on cell proliferation, Paramecium tetraurelia was grown under clinorotation (2.5 rpm) and the time course of the proliferation was investigated in detail on the basis of the logistic analysis. On the basis of the mechanical properties of Paramecium, this slow rate of the rotation appears to be enough to simulate microgravity in terms of the randomization of the cell orientation with respect to gravity. P. tetraurelia was cultivated in a closed chamber in which cells were confined without air bubbles, reducing the shear forces and turbulences under clinorotation. The chamber is made of quartz and silicone rubber film; the former is for the optically-flat walls for the measurement of cell density by means of a non-invasive laser optical-slice method, and the latter for gas exchange. Because of the small dimension for culture space, Paramecium does not accumulate at the top of the chamber in spite of its known negative gravitactic behavior. We measured the cell density at regular time intervals without breaking the configuration of the chamber, and analyzed the proliferation parameters by fitting the data to a logistic equation. As a result, P. tetraurelia showed reduced proliferation under slow clinorotation. The saturation of the cell density as well as the maximum proliferation rate decreased, although we found no significant changes on the half maximal time for proliferation. We also found that the mean swimming velocity decreased under slow clinorotation. These results were not consistent with those under microgravity and fast rotating clinostat. This may suggest that randomization of the cell orientation performed by slow rotating clinostat has

The novel protein C3orf43 accelerates hepatocyte proliferation.

PubMed

Zhang, Chunyan; Chang, Cuifang; Li, Deming; Zhang, Fuchun; Xu, Cunshuan

2017-01-01

Our previous study found that single-pass membrane protein with coiled-coil domains 1 (C3orf43; XM_006248472.3) was significantly upregulated in the proliferative phase during liver regeneration. This indicates that C3orf43 plays a vital role in liver cell proliferation. However, its physiological functions remains unclear. The expressions of C3orf43 in BRL-3A cells transfected with C3orf43-siRNA (C3-siRNA) or overexpressing the vector plasmid pCDH-C3orf43 (pCDH-C3) were measured via RT-qPCR and western blot. Cell growth and proliferation were determined using MTT and flow cytometry. Cell proliferation-related gene expression was measured using RT-qPCR and western blot. It was found that upregulation of C3orf43 by pCDH-C3 promoted hepatocyte proliferation, and inhibition of C3orf43 by C3-siRNA led to the reduction of cell proliferation. The results of qRT-PCR and western blot assay showed that the C3-siRNA group downregulated the expression of cell proliferation-related genes like JUN, MYC, CCND1 and CCNA2, and the pCDH-C3 group upregulated the expression of those genes. These findings reveal that C3orf43 may contribute to hepatocyte proliferation and may have the potential to promote liver repair and regeneration.

Cell Proliferation on Planar and Curved Substrates

NASA Astrophysics Data System (ADS)

Gaines, Michelle; Chang, Ya Wen; Cruz, Ricardo; Fragkopoulos, Alexandros; Garcia, Andres; Fernandez-Nieves, Alberto

Aberrant epithelial collective cell growth is one of the major challenges to be addressed in order to treat diseases such as cancer and organ fibrosis. The conditions of the extracellular microenvironment, properties of the cells' cytoskeleton, and interfacial properties of the substratum (the surface in contact with epithelial cells) have a significant influence on the migratory behavior of epithelial cells, cell proliferation and migration. This work focuses on understanding the impact the substratum curvature has on cell behavior. We focus on cell proliferation first and study MDCK cells on both planar and curved hydrogel substrates. The curved hydrogels are based on polyacrylamide and have toroidal shape, with tube radius 200 um and an aspect ratio in the rage between 2 and 9. Proliferation is measured using the Click-it EDU assay (Invitrogen), which measures cells that are synthesizing DNA. Funding Source is Childrens Healthcare of Atlanta.

Effect of nickel chloride on cell proliferation.

PubMed

D'Antò, Vincenzo; Valletta, Rosa; Amato, Massimo; Schweikl, Helmut; Simeone, Michele; Paduano, Sergio; Rengo, Sandro; Spagnuolo, Gianrico

2012-01-01

Metal alloys used in dentistry and in other biomedical fields may release nickel ions in the oral environment. The release of nickel might influence the normal biological and physiological processes, including tissue wound healing, cell growth and proliferation. The aim of this study was to evaluate in vitro the effects of nickel ions on cell cycle, viability and proliferation. Human osteosarcoma cells (U2OS) and human keratinocytes (HaCat) were exposed to different nickel chloride (NiCl(2)) concentrations (0 - 5mM) for various periods exposure. The viability of cultured cells was estimated by flow cytometry using Annexin V-FITC and Propidium Iodide (PI). Cell proliferation was evaluated by using carboxyfluorescein diacetate succinimidyl ester (CFDA-SE) and flow cytometry. Finally, the effects of NiCl(2) on cell cycle were assessed and quantified by flow cytometry. Statistical analysis was performed by means of ANOVA followed by Tukey's test. NiCl(2) induced a dose and time dependent decrease in cell viability. After 24h, 1mM NiCl(2) caused a similar and significant reduction of viability in U2OS and HaCat cells, while higher NiCl(2) concentrations and longer exposure times showed a reduced cytotoxic effect in HaCat as compared to U2OS cells. Exposure to NiCl(2) caused a dose- and time-dependent inhibition of cell proliferation in both cell lines tested, with a prominent effect on U2OS cells. Furthermore, both cell lines exposed to NiCl(2) exhibited significant changes in cell cycle distribution after 24h exposure 2mM NiCl2, as compared to untreated cells (p<0.05). Our results indicate that release of nickel ions may affect cell proliferation. The inhibition of cell growth by NiCl2 is mediated by both cell cycle arrest and by induction of cell death.

Induction of Malignant Plasma Cell Proliferation by Eosinophils

PubMed Central

Wong, Tina W.; Kita, Hirohito; Hanson, Curtis A.; Walters, Denise K.; Arendt, Bonnie K.; Jelinek, Diane F.

2013-01-01

The biology of the malignant plasma cells (PCs) in multiple myeloma (MM) is highly influenced by the bone marrow (BM) microenvironment in which they reside. More specifically, BM stromal cells (SCs) are known to interact with MM cells to promote MM cell survival and proliferation. By contrast, it is unclear if innate immune cells within this same space also actively participate in the pathology of MM. Our study shows for the first time that eosinophils (Eos) can contribute to the biology of MM by enhancing the proliferation of some malignant PCs. We first demonstrate that PCs and Eos can be found in close proximity in the BM. In culture, Eos were found to augment MM cell proliferation that is predominantly mediated through a soluble factor(s). Fractionation of cell-free supernatants and neutralization studies demonstrated that this activity is independent of Eos-derived microparticles and a proliferation-inducing ligand (APRIL), respectively. Using a multicellular in vitro system designed to resemble the native MM niche, SCs and Eos were shown to have non-redundant roles in their support of MM cell growth. Whereas SCs induce MM cell proliferation predominantly through the secretion of IL-6, Eos stimulate growth of these malignant cells via an IL-6-independent mechanism. Taken together, our study demonstrates for the first time a role for Eos in the pathology of MM and suggests that therapeutic strategies targeting these cells may be beneficial. PMID:23894671

Fisetin regulates astrocyte migration and proliferation in vitro

PubMed Central

Wang, Nan; Yao, Fang; Li, Ke; Zhang, Lanlan; Yin, Guo; Du, Mingjun; Wu, Bingyi

2017-01-01

Fisetin (3,3′,4′,7-tetrahydroxyflavone) is a plant flavonol found in fruits and vegetables that has been reported to inhibit migration and proliferation in several types of cancer. Reactive astrogliosis involves astrocyte migration and proliferation, and contributes to the formation of glial scars in central nervous system (CNS) disorders. However, the effect of fisetin on the migration and proliferation of astrocytes remains unclear. In this study, we found that fisetin inhibited astrocyte migration in a scratch-wound assay and diminished the phosphorylation of focal adhesion kinase (FAK; Tyr576/577 and paxillin (Tyr118). It also suppressed cell proliferation, as indicated by the decreased number of 5-ethynyl-2′-deoxyuridine (EdU)-positive cells, induced cell cycle arrest in the G1 phase, reduced the percentage of cells in the G2 and S phase (as measured by flow cytometry), and decreased cyclin D1 expression, but had no effect on apoptosis. Fisetin also decreased the phosphorylation levels of Akt and extracellular signal-regulated kinase (Erk)1/2, but had no effect on the phosphorylation of p38 mitogen-activated protein kinase (MAPK). These results indicate that fisetin inhibits aggressive cell phenotypes by suppressing cell migration and proliferation via the Akt/Erk signaling pathway. Fisetin may thus have potential for use as a therapeutic strategy targeting reactive astrocytes, which may lead to the inhibition of glial scar formation in vitro. PMID:28204814

Hypoxia induces pulmonary fibroblast proliferation through NFAT signaling.

PubMed

Senavirathna, Lakmini Kumari; Huang, Chaoqun; Yang, Xiaoyun; Munteanu, Maria Cristina; Sathiaseelan, Roshini; Xu, Dao; Henke, Craig A; Liu, Lin

2018-02-09

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive and typically fatal lung disease with a very low survival rate. Excess accumulation of fibroblasts, myofibroblasts and extracellular matrix creates hypoxic conditions within the lungs, causing asphyxiation. Hypoxia is, therefore, one of the prominent features of IPF. However, there have been few studies concerning the effects of hypoxia on pulmonary fibroblasts. In this study, we investigated the molecular mechanisms of hypoxia-induced lung fibroblast proliferation. Hypoxia increased the proliferation of normal human pulmonary fibroblasts and IPF fibroblasts after exposure for 3-6 days. Cell cycle analysis demonstrated that hypoxia promoted the G1/S phase transition. Hypoxia downregulated cyclin D1 and A2 levels, while it upregulated cyclin E1 protein levels. However, hypoxia had no effect on the protein expression levels of cyclin-dependent kinase 2, 4, and 6. Chemical inhibition of hypoxia-inducible factor (HIF)-2 reduced hypoxia-induced fibroblast proliferation. Moreover, silencing of Nuclear Factor Activated T cell (NFAT) c2 attenuated the hypoxia-mediated fibroblasts proliferation. Hypoxia also induced the nuclear translocation of NFATc2, as determined by immunofluorescence staining. NFAT reporter assays showed that hypoxia-induced NFAT signaling activation is dependent on HIF-2, but not HIF-1. Furthermore, the inhibition or silencing of HIF-2, but not HIF-1, reduced the hypoxia-mediated NFATc2 nuclear translocation. Our studies suggest that hypoxia induces the proliferation of human pulmonary fibroblasts through NFAT signaling and HIF-2.

Supporting aspartate biosynthesis is an essential function of respiration in proliferating cells

PubMed Central

Sullivan, Lucas B.; Gui, Dan Y.; Hosios, Aaron M.; Bush, Lauren N.; Freinkman, Elizaveta; Vander Heiden, Matthew G.

2015-01-01

Summary Mitochondrial respiration is important for cell proliferation, however the specific metabolic requirements fulfilled by respiration to support proliferation have not been defined. Here we show that a major role of respiration in proliferating cells is to provide electron acceptors for aspartate synthesis. This finding is consistent with the observation that cells lacking a functional respiratory chain are auxotrophic for pyruvate, which serves as an exogenous electron acceptor. Further, the pyruvate requirement can be fulfilled with an alternative electron acceptor, alpha-ketobutyrate, which provides cells neither carbon nor ATP. Alpha-ketobutyrate restores proliferation when respiration is inhibited, suggesting that an alternative electron acceptor can substitute for respiration to support proliferation. We find that electron acceptors are limiting for producing aspartate, and supplying aspartate enables proliferation of respiration deficient cells in the absence of exogenous electron acceptors. Together, these data argue a major function of respiration in proliferating cells is to support aspartate synthesis. PMID:26232225

Supporting Aspartate Biosynthesis Is an Essential Function of Respiration in Proliferating Cells.

PubMed

Sullivan, Lucas B; Gui, Dan Y; Hosios, Aaron M; Bush, Lauren N; Freinkman, Elizaveta; Vander Heiden, Matthew G

2015-07-30

Mitochondrial respiration is important for cell proliferation; however, the specific metabolic requirements fulfilled by respiration to support proliferation have not been defined. Here, we show that a major role of respiration in proliferating cells is to provide electron acceptors for aspartate synthesis. This finding is consistent with the observation that cells lacking a functional respiratory chain are auxotrophic for pyruvate, which serves as an exogenous electron acceptor. Further, the pyruvate requirement can be fulfilled with an alternative electron acceptor, alpha-ketobutyrate, which provides cells neither carbon nor ATP. Alpha-ketobutyrate restores proliferation when respiration is inhibited, suggesting that an alternative electron acceptor can substitute for respiration to support proliferation. We find that electron acceptors are limiting for producing aspartate, and supplying aspartate enables proliferation of respiration deficient cells in the absence of exogenous electron acceptors. Together, these data argue a major function of respiration in proliferating cells is to support aspartate synthesis. Copyright © 2015 Elsevier Inc. All rights reserved.

The new politics of missile proliferation

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

Karp, A.

1996-10-01

The author addresses the most consequential proliferation battle of the 1990s which occurred in Washington over the interpretation of the long-term threat to the United States from ballistic missiles. In the early 1970s, the stabilization of the US-Soviet strategic relationship led to new disputes over the other side`s future intentions, seen most graphically in Western debates over the implications of the Soviet SS-18 and SS-20 missile programs. Today, in much the same way, proliferation politics has matured to the point that surprises are few and the most challenging problem is anticipating the more distant future. Washington`s ballistic missile proliferation battlemore » was sparked by National Intelligence Estimate (NIE) 95-19, entitled {open_quotes}Emerging Threats to North America During the Next 15 Years,{close_quotes} released by the National Intelligence Council in November 1995. This document updated the evidence of regional missile programs reviewed in a similar report issued in 1993, and recapitulated the previous finding that {open_quotes}No country, other than the major declared nuclear powers, will develop or otherwise acquire a ballistic missile in the next 15 years that could threatened the contiguous 48 states or Canada.{close_quotes} The new report confirmed what several other studies of missile proliferation had already established: that besides the five nuclear-weapon states (the United States, Russia, China, France and Britain), only India, Israel and Japan are in a position to develop an ICBM during the foreseeable future, and while all have relevant capabilities, none are undertaking the steps necessary to develop an actual ICBM.« less

MicroRNA-27a promotes myoblast proliferation by targeting myostatin

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

Huang, Zhiqing; Chen, Xiaoling; Yu, Bing

2012-06-29

Highlights: Black-Right-Pointing-Pointer We identified a myogenic role for miR-27a and a new target, myostatin. Black-Right-Pointing-Pointer The miR-27a was confirmed to target myostatin 3 Prime UTR. Black-Right-Pointing-Pointer miR-27a is upregulated and myostatin is downregulated during myoblast proliferation. Black-Right-Pointing-Pointer miR-27a promotes myoblast proliferation by reducing the expression of myostatin. -- Abstract: MicroRNAs (miRNAs) are a class of endogenous non-coding RNAs that play critical roles in skeletal muscle development as well as in regulation of muscle cell proliferation and differentiation. However, the role of miRNAs in myoblast proliferation remains poorly understood. Here we found that the expression of miR-27a was increased during proliferationmore » of C2C12 myoblasts. Moreover, overexpression of miR-27a in C2C12 cells promoted myoblast proliferation by reducing the expression of myostatin, a critical inhibitor of skeletal myogenesis. In addition, the miR-27a was confirmed to target myostatin 3 Prime UTR by a luciferase reporter analysis. Together, these results suggest that miR-27a promotes myoblast proliferation through targeting myostatin.« less

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.

Isl-1 down-regulates DRG cell proliferation during chicken embryo development.

PubMed

Chen, Dawei; Wang, Guoxin; Luo, Haoshu; Liu, Jiali; Cui, Sheng

2010-01-01

Protein Isl-1 RNA interference and over expression in early chicken embryo dorsal root ganglia (DRG) were used to investigate the function of Isl-1 in DRG cell proliferation. Isl-1 targeted shRNA expression vector and Isl-1 over-expression vector were transfected into chicken embryo DRG by in ovo electroporation. Then, the DRG proliferation rate was detected by BrdU immunohistochemistry. The rate of DRG cell proliferation increased after Isl-1 knock-down and decreased after Isl-1 over-expression. In this study, we found that Isl-1 negatively modulates DRG cell proliferation.

Proliferation and the Former Soviet Union

DTIC Science & Technology

1994-09-23

YES, please send me the following: copies of Proliferation and the Former Soviet Union (104 pages), S / N 052-003-01384-3 at $6.50 each. Telephone...send me the following: copies of Proliferation and the Former Soviet Union (104 pages), S / N 052-003-01384-3 at $6.50 each. Telephone orders (202...is& >£&mäim iHl K illffS OJ OFFICE OF TECHNOLOGY ASSE 1MEMT CONGRESS OF THE UNITED S ^1 um ’FVt’^’TfirfVsr’’- sY «•fi1E,aH’fl; wrx 3prc«’’Xj

Neuronal models for evaluation of proliferation in vitro using high content screening.

PubMed

Mundy, William R; Radio, Nicholas M; Freudenrich, Theresa M

2010-04-11

In vitro test methods can provide a rapid approach for the screening of large numbers of chemicals for their potential to produce toxicity (hazard identification). In order to identify potential developmental neurotoxicants, a battery of in vitro tests for neurodevelopmental processes such as cell proliferation, differentiation, growth, and synaptogenesis has been proposed. The development of in vitro approaches for toxicity testing will require choosing a model system that is appropriate to the endpoint of concern. This study compared several cell lines as models for neuronal proliferation. The sensitivities of neuronal cell lines derived from three species (PC12, rat; N1E-115, mouse; SH-SY5Y, human) to chemicals known to affect cell proliferation were assessed using a high content screening system. After optimizing conditions for cell growth in 96-well plates, proliferation was measured as the incorporation of 5-bromo-2'-deoxyuridine (BrdU) into replicating DNA during S phase. BrdU-labeled cells were detected by immunocytochemistry and cell counts were obtained using automated image acquisition and analysis. The three cell lines showed approximately 30-40% of the population in S phase after a 4h pulse of BrdU. Exposure to the DNA polymerase inhibitor aphidicolin for 20 h prior to the 4h pulse of BrdU significantly decreased proliferation in all three cell lines. The sensitivities of the cell lines were compared by exposure to eight chemicals known to affect proliferation (positive controls) and determination of the concentration inhibiting proliferation by 50% of control (I(50)). PC12 cells were the most sensitive to chemicals; 6 out of 8 chemicals (aphidicolin, cadmium, cytosine arabinoside, dexamethasone, 5-fluorouracil, and methylmercury) inhibited proliferation at the concentrations tested. SH-SY5Y cells were somewhat less sensitive to chemical effects, with five out of eight chemicals inhibiting proliferation; dexamethasone had no effect, and cadmium

Sevoflurane suppresses proliferation by upregulating microRNA-203 in breast cancer cells.

PubMed

Liu, Jiaying; Yang, Longqiu; Guo, Xia; Jin, Guangli; Wang, Qimin; Lv, Dongdong; Liu, Junli; Chen, Qiu; Song, Qiong; Li, Baolin

2018-05-03

Rapid proliferation is one of the critical characteristics of breast cancer. However, the underlying regulatory mechanism of breast cancer cell proliferation is largely unclear. The present study indicated that sevoflurane, one of inhalational anesthetics, could significantly suppress breast cancer cell proliferation by arresting cell cycle at G1 phase. Notably, the rescue experiment indicated that miR-203 was upregulated by sevoflurane and mediated the function of sevoflurane on suppressing the breast cancer cell proliferation. The present study indicated the function of the sevoflurane/miR-203 signaling pathway on regulating breast cancer cell proliferation. These results provide mechanistic insight into how the sevoflurane/miR-203 signaling pathway supresses proliferation of breast cancer cells, suggesting the sevoflurane/miR-203 pathway may be a potential target in the treatment of breast cancer.

Molecular imaging of low-power laser irradiation induced cell proliferation

NASA Astrophysics Data System (ADS)

Gao, Xuejuan; Wang, Fang; Da, Xing

2006-02-01

Low-power laser irradiation (LPLI) has been shown to promote cell proliferation in various cell types, yet the mechanism of which has not been fully clarified. Studying the signaling pathways involved in the laser irradiation is important for understanding these processes. The Ras/Raf/MEK/ERK (extracellular-signal-regulated kinase) signaling pathway is a network that governs proliferation, differentiation and cell survival. Recent studies suggest that Ras/Raf signaling pathway is involved in the LPLI-induced cell proliferation. Protein kinase Cs (PKCs) have been recently presumed to be involved in the regulation of cell proliferation induced by LPLI. In present study, to monitor the direct interaction between Ras and Raf and PKCs activation after LPLI treatment in living cells in real time, Raichu-Ras reporter and C kinase activity reporter (CKAR) were utilized, both of which were constructed based on fluorescence resonance energy transfer (FRET) technique. Our results show that the direct interaction between Ras and Raf is monitored during cell proliferation induced by LPLI (0.8 J/cm2) in serum-starved human lung adenocarcinoma cells (ASTC-a-1) expressing Raichu-Ras reporter using FRET imaging on laser scanning confocal microscope, and that the increasing dynamics of PKCs activity is also monitored during cell proliferation induced by LPLI (0.8 J/cm2) in serum-starved ASTC-a-1 cells expressing CKAR reporter using the similar way. Taken together, LPLI induces the ASTC-a-1 cell proliferation by activated Ras directly interacting with Raf and by specifically activating PKCs.

Cell proliferation and differentiation in chemical leukemogenesis

NASA Technical Reports Server (NTRS)

Irons, R. D.; Stillman, W. S.; Clarkson, T. W. (Principal Investigator)

1993-01-01

In tissues such as bone marrow with normally high rates of cell division, proliferation is tightly coordinated with cell differentiation. Survival, proliferation and differentiation of early hematopoietic progenitor cells depend on the growth factors, interleukin 3 (IL-3) and/or granulocyte-macrophage colony stimulating factor (GM-CSF) and their synergism with other cytokines. We provide evidence that a characteristic shared by a diverse group of compounds with demonstrated leukemogenic potential is the ability to act synergistically with GM-CSF. This results in an increase in recruitment of a resting population of hematopoietic progenitor cells normally unresponsive to the cytokine and a twofold increase in the size of the proliferating cell population normally regarded to be at risk of transformation in leukemogenesis. These findings support the possibility that transient alterations in hematopoietic progenitor cell differentiation may be an important factor in the early stages of development of leukemia secondary to chemical or drug exposure.

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.

Geospatial Image Mining For Nuclear Proliferation Detection: Challenges and New Opportunities

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

Vatsavai, Raju; Bhaduri, Budhendra L; Cheriyadat, Anil M

2010-01-01

With increasing understanding and availability of nuclear technologies, and increasing persuasion of nuclear technologies by several new countries, it is increasingly becoming important to monitor the nuclear proliferation activities. There is a great need for developing technologies to automatically or semi-automatically detect nuclear proliferation activities using remote sensing. Images acquired from earth observation satellites is an important source of information in detecting proliferation activities. High-resolution remote sensing images are highly useful in verifying the correctness, as well as completeness of any nuclear program. DOE national laboratories are interested in detecting nuclear proliferation by developing advanced geospatial image mining algorithms. Inmore » this paper we describe the current understanding of geospatial image mining techniques and enumerate key gaps and identify future research needs in the context of nuclear proliferation.« less

Early Postnatal Cardiomyocyte Proliferation Requires High Oxidative Energy Metabolism.

PubMed

de Carvalho, Ana Elisa Teófilo Saturi; Bassaneze, Vinícius; Forni, Maria Fernanda; Keusseyan, Aline Alfonso; Kowaltowski, Alicia Juliana; Krieger, José Eduardo

2017-11-13

Cardiac energy metabolism must cope with early postnatal changes in tissue oxygen tensions, hemodynamics, and cell proliferation to sustain development. Here, we tested the hypothesis that proliferating neonatal cardiomyocytes are dependent on high oxidative energy metabolism. We show that energy-related gene expression does not correlate with functional oxidative measurements in the developing heart. Gene expression analysis suggests a gradual overall upregulation of oxidative-related genes and pathways, whereas functional assessment in both cardiac tissue and cultured cardiomyocytes indicated that oxidative metabolism decreases between the first and seventh days after birth. Cardiomyocyte extracellular flux analysis indicated that the decrease in oxidative metabolism between the first and seventh days after birth was mostly related to lower rates of ATP-linked mitochondrial respiration, suggesting that overall energetic demands decrease during this period. In parallel, the proliferation rate was higher for early cardiomyocytes. Furthermore, in vitro nonlethal chemical inhibition of mitochondrial respiration reduced the proliferative capacity of early cardiomyocytes, indicating a high energy demand to sustain cardiomyocyte proliferation. Altogether, we provide evidence that early postnatal cardiomyocyte proliferative capacity correlates with high oxidative energy metabolism. The energy requirement decreases as the proliferation ceases in the following days, and both oxidative-dependent metabolism and anaerobic glycolysis subside.

Zinc oxide nanoparticles as selective killers of proliferating cells.

PubMed

Taccola, Liuba; Raffa, Vittoria; Riggio, Cristina; Vittorio, Orazio; Iorio, Maria Carla; Vanacore, Renato; Pietrabissa, Andrea; Cuschieri, Alfred

2011-01-01

It has recently been demonstrated that zinc oxide nanoparticles (ZnO NPs) induce death of cancerous cells whilst having no cytotoxic effect on normal cells. However, there are several issues which need to be resolved before translation of zinc oxide nanoparticles into medical use, including lack of suitable biocompatible dispersion protocols and a better understanding being needed of the mechanism of their selective cytotoxic action. Nanoparticle dose affecting cell viability was evaluated in a model of proliferating cells both experimentally and mathematically. The key issue of selective toxicity of ZnO NPs toward proliferating cells was addressed by experiments using a biological model of noncancerous cells, ie, mesenchymal stem cells before and after cell differentiation to the osteogenic lineage. In this paper, we report a biocompatible protocol for preparation of stable aqueous solutions of monodispersed zinc oxide nanoparticles. We found that the threshold of intracellular ZnO NP concentration required to induce cell death in proliferating cells is 0.4 ± 0.02 mM. Finally, flow cytometry analysis revealed that the threshold dose of zinc oxide nanoparticles was lethal to proliferating pluripotent mesenchymal stem cells but exhibited negligible cytotoxic effects to osteogenically differentiated mesenchymal stem cells. Results confirm the ZnO NP selective cytotoxic action on rapidly proliferating cells, whether benign or malignant.

The cell proliferation antigen Ki-67 organises heterochromatin

PubMed Central

Sobecki, Michal; Mrouj, Karim; Camasses, Alain; Parisis, Nikolaos; Nicolas, Emilien; Llères, David; Gerbe, François; Prieto, Susana; Krasinska, Liliana; David, Alexandre; Eguren, Manuel; Birling, Marie-Christine; Urbach, Serge; Hem, Sonia; Déjardin, Jérôme; Malumbres, Marcos; Jay, Philippe; Dulic, Vjekoslav; Lafontaine, Denis LJ; Feil, Robert; Fisher, Daniel

2016-01-01

Antigen Ki-67 is a nuclear protein expressed in proliferating mammalian cells. It is widely used in cancer histopathology but its functions remain unclear. Here, we show that Ki-67 controls heterochromatin organisation. Altering Ki-67 expression levels did not significantly affect cell proliferation in vivo. Ki-67 mutant mice developed normally and cells lacking Ki-67 proliferated efficiently. Conversely, upregulation of Ki-67 expression in differentiated tissues did not prevent cell cycle arrest. Ki-67 interactors included proteins involved in nucleolar processes and chromatin regulators. Ki-67 depletion disrupted nucleologenesis but did not inhibit pre-rRNA processing. In contrast, it altered gene expression. Ki-67 silencing also had wide-ranging effects on chromatin organisation, disrupting heterochromatin compaction and long-range genomic interactions. Trimethylation of histone H3K9 and H4K20 was relocalised within the nucleus. Finally, overexpression of human or Xenopus Ki-67 induced ectopic heterochromatin formation. Altogether, our results suggest that Ki-67 expression in proliferating cells spatially organises heterochromatin, thereby controlling gene expression. DOI: http://dx.doi.org/10.7554/eLife.13722.001 PMID:26949251

Electrospun fiber membranes enable proliferation of genetically modified cells

PubMed Central

Borjigin, Mandula; Eskridge, Chris; Niamat, Rohina; Strouse, Bryan; Bialk, Pawel; Kmiec, Eric B

2013-01-01

Polycaprolactone (PCL) and its blended composites (chitosan, gelatin, and lecithin) are well-established biomaterials that can enrich cell growth and enable tissue engineering. However, their application in the recovery and proliferation of genetically modified cells has not been studied. In the study reported here, we fabricated PCL-biomaterial blended fiber membranes, characterized them using physicochemical techniques, and used them as templates for the growth of genetically modified HCT116-19 colon cancer cells. Our data show that the blended polymers are highly miscible and form homogenous electrospun fiber membranes of uniform texture. The aligned PCL nanofibers support robust cell growth, yielding a 2.5-fold higher proliferation rate than cells plated on standard plastic plate surfaces. PCL-lecithin fiber membranes yielded a 2.7-fold higher rate of proliferation, while PCL-chitosan supported a more modest growth rate (1.5-fold higher). Surprisingly, PCL-gelatin did not enhance cell proliferation when compared to the rate of cell growth on plastic surfaces. PMID:23467983

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.

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

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

Cardiomyocyte-released factors stimulate oligodendrocyte precursor cells proliferation

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

Kuroda, Mariko; Muramatsu, Rieko; Precursory Research for Embryonic Science and Technology

The heart produces multiple diffusible factors that are involved in a number of physiological processes, but the action of these factors on the central nervous system is not well understood. In this study, we found that one or more factors released by cardiomyocytes promote oligodendrocyte precursor cell (OPC) proliferation in vitro. Mouse OPCs co-cultured with mouse cardiomyocytes showed higher proliferative ability than OPCs cultured alone. In addition, cardiomyocyte-conditioned media was sufficient to promote OPC proliferation. The phosphorylation of phosphatidylinositol (PI) 3-kinase and extracellular signal-regulated kinase (ERK) in OPCs is necessary for the enhancement of OPC proliferation by cardiomyocyte-conditioned media. These datamore » indicate that heart-derived factors have the ability to directly regulate the function of central nervous system (CNS) cells.« less

Activation of PPARbeta/delta induces endothelial cell proliferation and angiogenesis.

PubMed

Piqueras, Laura; Reynolds, Andrew R; Hodivala-Dilke, Kairbaan M; Alfranca, Arántzazu; Redondo, Juan M; Hatae, Toshihisa; Tanabe, Tadashi; Warner, Timothy D; Bishop-Bailey, David

2007-01-01

The role of the nuclear receptor peroxisome-proliferator activated receptor (PPAR)-beta/delta in endothelial cells remains unclear. Interestingly, the selective PPARbeta/delta ligand GW501516 is in phase II clinical trials for dyslipidemia. Here, using GW501516, we have assessed the involvement of PPARbeta/delta in endothelial cell proliferation and angiogenesis. Western blot analysis indicated PPARbeta/delta was expressed in primary human umbilical and aortic endothelial cells, and in the endothelial cell line, EAHy926. Treatment with GW501516 increased human endothelial cell proliferation and morphogenesis in cultures in vitro, endothelial cell outgrowth from murine aortic vessels in vitro, and angiogenesis in a murine matrigel plug assay in vivo. GW501516 induced vascular endothelial cell growth factor mRNA and peptide release, as well as adipose differentiation-related protein (ADRP), a PPARbeta/delta target gene. GW501516-induced proliferation, morphogenesis, vascular endothelial growth factor (VEGF), and ADRP were absent in endothelial cells transfected with dominant-negative PPARbeta/delta. Furthermore, treatment of cells with cyclo-VEGFI, a VEGF receptor1/2 antagonist, abolished GW501516-induced endothelial cell proliferation and tube formation. PPARbeta/delta is a novel regulator of endothelial cell proliferation and angiogenesis through VEGF. The use of GW501516 to treat dyslipidemia may need to be carefully monitored in patients susceptible to angiogenic disorders.

Inhibition of Fatty Acid Metabolism Reduces Human Myeloma Cells Proliferation

PubMed Central

Tirado-Vélez, José Manuel; Joumady, Insaf; Sáez-Benito, Ana; Cózar-Castellano, Irene; Perdomo, Germán

2012-01-01

Multiple myeloma is a haematological malignancy characterized by the clonal proliferation of plasma cells. It has been proposed that targeting cancer cell metabolism would provide a new selective anticancer therapeutic strategy. In this work, we tested the hypothesis that inhibition of β-oxidation and de novo fatty acid synthesis would reduce cell proliferation in human myeloma cells. We evaluated the effect of etomoxir and orlistat on fatty acid metabolism, glucose metabolism, cell cycle distribution, proliferation, cell death and expression of G1/S phase regulatory proteins in myeloma cells. Etomoxir and orlistat inhibited β-oxidation and de novo fatty acid synthesis respectively in myeloma cells, without altering significantly glucose metabolism. These effects were associated with reduced cell viability and cell cycle arrest in G0/G1. Specifically, etomoxir and orlistat reduced by 40–70% myeloma cells proliferation. The combination of etomoxir and orlistat resulted in an additive inhibitory effect on cell proliferation. Orlistat induced apoptosis and sensitized RPMI-8226 cells to apoptosis induction by bortezomib, whereas apoptosis was not altered by etomoxir. Finally, the inhibitory effect of both drugs on cell proliferation was associated with reduced p21 protein levels and phosphorylation levels of retinoblastoma protein. In conclusion, inhibition of fatty acid metabolism represents a potential therapeutic approach to treat human multiple myeloma. PMID:23029529

BET bromodomain proteins are required for glioblastoma cell proliferation.

PubMed

Pastori, Chiara; Daniel, Mark; Penas, Clara; Volmar, Claude-Henry; Johnstone, Andrea L; Brothers, Shaun P; Graham, Regina M; Allen, Bryce; Sarkaria, Jann N; Komotar, Ricardo J; Wahlestedt, Claes; Ayad, Nagi G

2014-04-01

Epigenetic proteins have recently emerged as novel anticancer targets. Among these, bromodomain and extra terminal domain (BET) proteins recognize lysine-acetylated histones, thereby regulating gene expression. Newly described small molecules that inhibit BET proteins BRD2, BRD3, and BRD4 reduce proliferation of NUT (nuclear protein in testis)-midline carcinoma, multiple myeloma, and leukemia cells in vitro and in vivo. These findings prompted us to determine whether BET proteins may be therapeutic targets in the most common primary adult brain tumor, glioblastoma (GBM). We performed NanoString analysis of GBM tumor samples and controls to identify novel therapeutic targets. Several cell proliferation assays of GBM cell lines and stem cells were used to analyze the efficacy of the drug I-BET151 relative to temozolomide (TMZ) or cell cycle inhibitors. Lastly, we performed xenograft experiments to determine the efficacy of I-BET151 in vivo. We demonstrate that BRD2 and BRD4 RNA are significantly overexpressed in GBM, suggesting that BET protein inhibition may be an effective means of reducing GBM cell proliferation. Disruption of BRD4 expression in glioblastoma cells reduced cell cycle progression. Similarly, treatment with the BET protein inhibitor I-BET151 reduced GBM cell proliferation in vitro and in vivo. I-BET151 treatment enriched cells at the G1/S cell cycle transition. Importantly, I-BET151 is as potent at inhibiting GBM cell proliferation as TMZ, the current chemotherapy treatment administered to GBM patients. Since I-BET151 inhibits GBM cell proliferation by arresting cell cycle progression, we propose that BET protein inhibition may be a viable therapeutic option for GBM patients suffering from TMZ resistant tumors.

BET bromodomain proteins are required for glioblastoma cell proliferation

PubMed Central

Pastori, Chiara; Daniel, Mark; Penas, Clara; Volmar, Claude-Henry; Johnstone, Andrea L; Brothers, Shaun P; Graham, Regina M; Allen, Bryce; Sarkaria, Jann N; Komotar, Ricardo J; Wahlestedt, Claes; Ayad, Nagi G

2014-01-01

Epigenetic proteins have recently emerged as novel anticancer targets. Among these, bromodomain and extra terminal domain (BET) proteins recognize lysine-acetylated histones, thereby regulating gene expression. Newly described small molecules that inhibit BET proteins BRD2, BRD3, and BRD4 reduce proliferation of NUT (nuclear protein in testis)-midline carcinoma, multiple myeloma, and leukemia cells in vitro and in vivo. These findings prompted us to determine whether BET proteins may be therapeutic targets in the most common primary adult brain tumor, glioblastoma (GBM). We performed NanoString analysis of GBM tumor samples and controls to identify novel therapeutic targets. Several cell proliferation assays of GBM cell lines and stem cells were used to analyze the efficacy of the drug I-BET151 relative to temozolomide (TMZ) or cell cycle inhibitors. Lastly, we performed xenograft experiments to determine the efficacy of I-BET151 in vivo. We demonstrate that BRD2 and BRD4 RNA are significantly overexpressed in GBM, suggesting that BET protein inhibition may be an effective means of reducing GBM cell proliferation. Disruption of BRD4 expression in glioblastoma cells reduced cell cycle progression. Similarly, treatment with the BET protein inhibitor I-BET151 reduced GBM cell proliferation in vitro and in vivo. I-BET151 treatment enriched cells at the G1/S cell cycle transition. Importantly, I-BET151 is as potent at inhibiting GBM cell proliferation as TMZ, the current chemotherapy treatment administered to GBM patients. Since I-BET151 inhibits GBM cell proliferation by arresting cell cycle progression, we propose that BET protein inhibition may be a viable therapeutic option for GBM patients suffering from TMZ resistant tumors. PMID:24496381

Neuropeptide Y stimulates retinal neural cell proliferation--involvement of nitric oxide.

PubMed

Alvaro, Ana Rita; Martins, João; Araújo, Inês M; Rosmaninho-Salgado, Joana; Ambrósio, António F; Cavadas, Cláudia

2008-06-01

Neuropeptide Y (NPY) is a 36 amino acid peptide widely present in the CNS, including the retina. Previous studies have demonstrated that NPY promotes cell proliferation of rat post-natal hippocampal and olfactory epithelium precursor cells. The aim of this work was to investigate the role of NPY on cell proliferation of rat retinal neural cells. For this purpose, primary retinal cell cultures expressing NPY, and NPY Y(1), Y(2), Y(4) and Y(5) receptors [Alvaro et al., (2007) Neurochem. Int., 50, 757] were used. NPY (10-1000 nM) stimulated cell proliferation through the activation of NPY Y(1), Y(2) and Y(5) receptors. NPY also increased the number of proliferating neuronal progenitor cells (BrdU(+)/nestin(+) cells). The intracellular mechanisms coupled to NPY receptors activation that mediate the increase in cell proliferation were also investigated. The stimulatory effect of NPY on cell proliferation was reduced by L-nitroarginine-methyl-esther (L-NAME; 500 microM), a nitric oxide synthase inhibitor, 1H-[1,2,4]oxadiazolo-[4, 3-a]quinoxalin-1-one (ODQ; 20 microM), a soluble guanylyl cyclase inhibitor or U0126 (1 microM), an inhibitor of the extracellular signal-regulated kinase 1/2 (ERK 1/2). In conclusion, NPY stimulates retinal neural cell proliferation, and this effect is mediated through nitric oxide-cyclic GMP and ERK 1/2 pathways.

Role of magnolol in the proliferation of vascular smooth muscle cells.

PubMed

Wu, L; Zou, H; Xia, W; Dong, Q; Wang, L

2015-05-01

Proliferation of vascular smooth muscle cells (VSMCs) contributes to the development of vascular remodeling. Recently, magnolol has been reported to have a potential role in regulating tumor necrosis factor α-induced proliferation of VSMCs. However, the role of magnolol in platelet-derived growth factor (PDGF)-induced proliferation of VSMCs remains unknown. Our purpose was to elucidate the effect of magnolol on the proliferation of VSMCs induced by PDGF-BB and to investigate the underlying molecular mechanisms. Our data demonstrated that magnolol inhibited rat VSMC proliferation and DNA synthesis stimulated by 20 ng/ml PDGF-BB without causing cell cytotoxicity. Flow cytometric analysis showed that magnolol inhibited S-phase entry of VSMCs. We also demonstrated that magnolol caused this effect by inhibiting the mRNA and protein expression of cyclin D1, cyclin E, and cyclin-dependent kinases 2 and 4 in PDGF-BB-stimulated VSMCs. Further analysis showed that the inhibitory effect of magnolol on the proliferation of VSMCs was associated with the inhibition of the PDGF-BB-stimulated production of intracellular reactive oxygen species (ROS) and Ras, MEK, and ERK1/2 activation. These results demonstrate that magnolol can block the proliferation of VSMCs through inhibition of intracellular ROS production and Ras-MEK-ERK1/2 pathways. Magnolol, therefore, has a potential application in preventing atherosclerosis and restenosis.

Effect of different wound dressings on cell viability and proliferation.

PubMed

Paddle-Ledinek, Joanne E; Nasa, Zeyad; Cleland, Heather J

2006-06-01

Many new dressings have been developed since the early 1980s. Wound healing comprises cleansing, granulation/vascularization, and epithelialization phases. An optimum microenvironment and the absence of cytotoxic factors are essential for epithelialization. This study examines the effect of extracts of different wound dressings on keratinocyte survival and proliferation. Keratinocyte cultures were exposed for 40 hours to at least three extracts of each of the following wound dressings, which were tested in octuplicate: Acticoat, Aquacel-Ag, Aquacel, Algisite M, Avance, Comfeel Plus transparent, Contreet-H, Hydrasorb, and SeaSorb. Silicone extract provided the reference material. Controls were included of cells cultured in medium that had been incubated under conditions identical to those used with the extracts. Cell survival (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide reduction) and proliferation (5-bromo-2':-deoxyuridine incorporation) were measured. Extracts of silver-containing dressings (Acticoat, Aquacel-Ag, Contreet-H, and Avance) were most cytotoxic. Extracts of Hydrasorb were less cytotoxic but markedly affected keratinocyte proliferation and morphology. Extracts of alginate-containing dressings (Algisite M, SeaSorb, and Contreet-H) demonstrated high calcium concentrations, markedly reduced keratinocyte proliferation, and affected keratinocyte morphology. Extracts of Aquacel and Comfeel Plus transparent induced small but significant inhibition of keratinocyte proliferation. The principle of minimizing harm should be applied to the choice of wound dressing. Silver-based dressings are cytotoxic and should not be used in the absence of infection. Alginate dressings with high calcium content affect keratinocyte proliferation probably by triggering terminal differentiation of keratinocytes. Such dressings should be used with caution in cases in which keratinocyte proliferation is essential. All dressings should be tested in vitro before

Effect of Nickel Chloride on Cell Proliferation

PubMed Central

D’Antò, Vincenzo; Valletta, Rosa; Amato, Massimo; Schweikl, Helmut; Simeone, Michele; Paduano, Sergio; Rengo, Sandro; Spagnuolo, Gianrico

2012-01-01

Objective: Metal alloys used in dentistry and in other biomedical fields may release nickel ions in the oral environment. The release of nickel might influence the normal biological and physiological processes, including tissue wound healing, cell growth and proliferation. The aim of this study was to evaluate in vitro the effects of nickel ions on cell cycle, viability and proliferation. Materials and Methods: Human osteosarcoma cells (U2OS) and human keratinocytes (HaCat) were exposed to different nickel chloride (NiCl2) concentrations (0 - 5mM) for various periods exposure. The viability of cultured cells was estimated by flow cytometry using Annexin V-FITC and Propidium Iodide (PI). Cell proliferation was evaluated by using carboxyfluorescein diacetate succinimidyl ester (CFDA-SE) and flow cytometry. Finally, the effects of NiCl2 on cell cycle were assessed and quantified by flow cytometry. Statistical analysis was performed by means of ANOVA followed by Tukey’s test. Results: NiCl2 induced a dose and time dependent decrease in cell viability. After 24h, 1mM NiCl2 caused a similar and significant reduction of viability in U2OS and HaCat cells, while higher NiCl2 concentrations and longer exposure times showed a reduced cytotoxic effect in HaCat as compared to U2OS cells. Exposure to NiCl2 caused a dose- and time-dependent inhibition of cell proliferation in both cell lines tested, with a prominent effect on U2OS cells. Furthermore, both cell lines exposed to NiCl2 exhibited significant changes in cell cycle distribution after 24h exposure 2mM NiCl2, as compared to untreated cells (p<0.05). Conclusion: Our results indicate that release of nickel ions may affect cell proliferation. The inhibition of cell growth by NiCl2 is mediated by both cell cycle arrest and by induction of cell death. PMID:23198004

Zinc oxide nanoparticles as selective killers of proliferating cells

PubMed Central

Taccola, Liuba; Raffa, Vittoria; Riggio, Cristina; Vittorio, Orazio; Iorio, Maria Carla; Vanacore, Renato; Pietrabissa, Andrea; Cuschieri, Alfred

2011-01-01

Background: It has recently been demonstrated that zinc oxide nanoparticles (ZnO NPs) induce death of cancerous cells whilst having no cytotoxic effect on normal cells. However, there are several issues which need to be resolved before translation of zinc oxide nanoparticles into medical use, including lack of suitable biocompatible dispersion protocols and a better understanding being needed of the mechanism of their selective cytotoxic action. Methods: Nanoparticle dose affecting cell viability was evaluated in a model of proliferating cells both experimentally and mathematically. The key issue of selective toxicity of ZnO NPs toward proliferating cells was addressed by experiments using a biological model of noncancerous cells, ie, mesenchymal stem cells before and after cell differentiation to the osteogenic lineage. Results: In this paper, we report a biocompatible protocol for preparation of stable aqueous solutions of monodispersed zinc oxide nanoparticles. We found that the threshold of intracellular ZnO NP concentration required to induce cell death in proliferating cells is 0.4 ± 0.02 mM. Finally, flow cytometry analysis revealed that the threshold dose of zinc oxide nanoparticles was lethal to proliferating pluripotent mesenchymal stem cells but exhibited negligible cytotoxic effects to osteogenically differentiated mesenchymal stem cells. Conclusion: Results confirm the ZnO NP selective cytotoxic action on rapidly proliferating cells, whether benign or malignant. PMID:21698081

In vitro toxicity of photodynamic antimicrobial chemotherapy on human keratinocytes proliferation.

PubMed

Migliario, Mario; Rizzi, Manuela; Rocchetti, Vincenzo; Cannas, Mario; Renò, Filippo

2013-02-01

This in vitro experimental study has been designed to assess the effects of photodynamic antimicrobial chemotherapy (PACT) on human keratinocytes proliferation. Human keratinocytes (HaCaT) monolayers (∼0.5 cm(2)) have been irradiated with 635 nm red laser light with a fluence of 82.5 or 112.5 J/cm(2) in the absence or presence of toluidine (TB). Cell proliferation, monolayer area coverage, cytokeratin 5 (K5) and filaggrin (Fil) expression, and metalloproteinase (MMP)-2 and MMP-9 activity were measured after 72 h from laser irradiation. HaCaT proliferation was reduced by TB staining. Cell exposure to both low- and high-fluence laser irradiation in both presence and absence of TB staining reduced their proliferation and monolayer area extension. Moreover both laser treatments were able to reduce K5 and Fil expression and MMP-9 production in keratinocytes not treated with TB. These data indicate that PACT could exert toxic effects on normal proliferating keratinocytes present around parodontal pockets. The observed reduced cell proliferation along with a reduced production of enzymes involved in wound healing could alter the clinical outcome of the patients treated with PACT.

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.

Proliferating macrophages prevail in atherosclerosis.

PubMed

Randolph, Gwendalyn J

2013-09-01

Macrophages accumulate in atherosclerotic lesions during the inflammation that is part of atherosclerosis development and progression. A new study in mice indicates that the accumulation of macrophages in atherosclerotic plaques depends on local macrophage proliferation rather than the recruitment of circulating monocytes.

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.

Aldosterone Promotes Cardiac Endothelial Cell Proliferation In Vivo

PubMed Central

Gravez, Basile; Tarjus, Antoine; Pelloux, Véronique; Ouvrard‐Pascaud, Antoine; Delcayre, Claude; Samuel, Janelise; Clément, Karine; Farman, Nicolette; Jaisser, Fréderic; Messaoudi, Smail

2015-01-01

Background Experimentally, aldosterone in association with NaCl induces cardiac fibrosis, oxidative stress, and inflammation through mineralocorticoid receptor activation; however, the biological processes regulated by aldosterone alone in the heart remain to be identified. Methods and Results Mice were treated for 7 days with aldosterone, and then cardiac transcriptome was analyzed. Aldosterone regulated 60 transcripts (51 upregulated and 9 downregulated) in the heart (fold change ≥1.5, false discovery rate <0.01). To identify the biological processes modulated by aldosterone, a gene ontology analysis was performed. The majority of aldosterone‐regulated genes were involved in cell division. The cardiac Ki‐67 index (an index of proliferation) of aldosterone‐treated mice was higher than that of nontreated mice, confirming microarray predictions. Costaining of Ki‐67 with vinculin, CD68, α‐smooth muscle actin, CD31, or caveolin 1 revealed that the cycling cells were essentially endothelial cells. Aldosterone‐induced mineralocorticoid receptor–dependent proliferation was confirmed ex vivo in human endothelial cells. Moreover, pharmacological‐specific blockade of mineralocorticoid receptor by eplerenone inhibited endothelial cell proliferation in a preclinical model of heart failure (transverse aortic constriction). Conclusions Aldosterone modulates cardiac gene expression and induces the proliferation of cardiac endothelial cells in vivo. PMID:25564371

Nesfatin-1 inhibits ovarian epithelial carcinoma cell proliferation in vitro

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

Xu, Yang; Pang, Xiaoyan; Dong, Mei

Highlights: •Nesfatin-1 inhibits the proliferation and growth of HO-8910 cells by G1 phase arrest. •Nesfatin-1 enhances HO-8910 cell apoptosis. •Nesfatin-1 inhibits HO-8910 cell proliferation via mTOR and RhoA/ROCK signaling pathway. •The first report of nesfatin-1-mediated proliferation in ovarian epithelial carcinoma. -- Abstract: Nesfatin-1, an 82-amino-acid peptide derived from a 396-amino-acid precursor protein nucleobindin 2 (NUCB2), was originally identified in hypothalamic nuclei involved in the regulation of food intake. It was recently reported that nesfatin-1 is a novel depot specific adipokine preferentially produced by subcutaneous tissue, with obesity- and food deprivation-regulated expression. Although a relation between ovarian cancer mortality and obesitymore » has been previously established, a role of nesfatin-1 in ovarian epithelial carcinoma remains unknown. The aim of the present study is to examine the effect of nesfatin-1 on ovary carcinoma cells proliferation. We found that nesfatin-1 inhibits the proliferation and growth of HO-8910 cells by G1 phase arrest, this inhibition could be abolished by nesfatin-1 neutralizing antibody. Nesfatin-1 enhances HO-8910 cell apoptosis, activation of mammalian target of rapamycin (mTOR) and RhoA/ROCK signaling pathway block the effects of nesfatin-1-induced apoptosis, therefore reverses the inhibition of HO-8910 cell proliferation by nesfatin-1. In conclusion, the present study demonstrated that nesfatin-1 can inhibit the proliferation in human ovarian epithelial carcinoma cell line HO-8910 cells through inducing apoptosis via mTOR and RhoA/ROCK signaling pathway. This study provides a novel regulatory signaling pathway of nesfatin-1-regulated ovarian epithelial carcinoma growth and may contribute to ovarian cancer prevention and therapy, especially in obese patients.« less

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.

Effects of neuropeptides on human lung fibroblast proliferation and chemotaxis.

PubMed

Harrison, N K; Dawes, K E; Kwon, O J; Barnes, P J; Laurent, G J; Chung, K F

1995-02-01

An increase in subepithelial mesenchymal cells and associated connective tissue is a feature of bronchial asthma. We determined whether neuropeptides could modulate fibroblast activity, particularly with respect to proliferation and chemotaxis. Human lung fibroblasts were cultured with neurokinin A (NKA), substance P (SP), vasoactive intestinal peptide (VIP), and calcitonin-gene-related peptide (CGRP). After 48 h, fibroblast proliferation was measured by a colorimetric assay based on the uptake and subsequent release of methylene blue. The chemotactic response to neuropeptides was determined with the use of a modified Boyden chamber. Both NKA and SP (10(-7)-10(-4) M) stimulated human lung fibroblast proliferation in HFL1 and IMR-90 fibroblasts. VIP and CGRP had no effect on fibroblast proliferation. NKA alone stimulated fibroblast chemotaxis maximally at 10(-10) M. Neutral endopeptidase (NEP) activity of 0.52 and 5.2 pmol/10(6) cells was assayed in IMR-90 and Hs68 fibroblasts, respectively. Phosphoramidon (5 x 10(-6)-10(-5) M), an NEP inhibitor, enhanced fibroblast proliferation in a dose-dependent manner. Thus neuropeptides have the potential to cause activation of mesenchymal cells, and neuropeptide release may contribute to the structural abnormalities observed in asthmatic airways.

Preventing ballistic missile proliferation: Lessons from Iraq. Master`s thesis

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

Talay, B.J.

1996-12-01

This thesis examines the case of Iraq to assess the performance of the missile nonproliferation regime since 1970. By analyzing the methods used by Iraq to obtain missile systems and missile technology, this thesis assesses the ability of the international community to prevent ballistic missile proliferation. Understanding Iraq`s past capabilities as well as its post-war efforts to rebuild weapons programs and procurement networks, this thesis provides suggestions for improving the regime`s performance. This thesis finds that (1) prior to 1992, the Missile Technology Control Regime (MTCR) failed in its attempts to prevent proliferation; (2) the existence of the MTCR, whilemore » necessary to slow proliferation, is not sufficient to prevent proliferation; and (3) additional enforcement is needed to counter weapons of mass destruction acquisition by resourceful and determined states.« less

Nanocarbon Allotropes-Graphene and Nanocrystalline Diamond-Promote Cell Proliferation.

PubMed

Verdanova, Martina; Rezek, Bohuslav; Broz, Antonin; Ukraintsev, Egor; Babchenko, Oleg; Artemenko, Anna; Izak, Tibor; Kromka, Alexander; Kalbac, Martin; Hubalek Kalbacova, Marie

2016-05-01

Two profoundly different carbon allotropes - nanocrystalline diamond and graphene - are of considerable interest from the viewpoint of a wide range of biomedical applications including implant coating, drug and gene delivery, cancer therapy, and biosensing. Osteoblast adhesion and proliferation on nanocrystalline diamond and graphene are compared under various conditions such as differences in wettability, topography, and the presence or absence of protein interlayers between cells and the substrate. The materials are characterized in detail by means of scanning electron microscopy, atomic force microscopy, photoelectron spectroscopy, Raman spectroscopy, and contact angle measurements. In vitro experiments have revealed a significantly higher degree of cell proliferation on graphene than on nanocrystalline diamond and a tissue culture polystyrene control material. Proliferation is promoted, in particular, by hydrophobic graphene with a large number of nanoscale wrinkles independent of the presence of a protein interlayer, i.e., substrate fouling is not a problematic issue in this respect. Nanowrinkled hydrophobic graphene, thus, exhibits superior characteristics for those biomedical applications where high cell proliferation is required under differing conditions. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Sildenafil Inhibits the Proliferation of Cultured Human Endothelial Cells

PubMed Central

Erdogan, Ali; Luedders, Doerte Wiebke; Muenz, Benedikt Manuel; Schaefer, Christian Alexander; Tillmanns, Harald; Wiecha, Johannes; Kuhlmann, Christoph Ruediger Wolfram

2007-01-01

The proliferation of endothelial cells plays a crucial role in the development of intraplaque angiogenesis (IPA). IPA is a major source of intraplaque hemorrhage and therefore contributes to the destabilization of atherosclerotic plaques. Therefore, the aim of the present study was to examine, whether sildenafil inhibits endothelial cell growth. The proliferation of human endothelial cells derived from umbilical cord veins (HUVEC) was examined on DNA level by measurements of (3H)-thymidine incorporation. Cell viability was analyzed using trypan blue staining. The proliferation of cultured human endothelial cells was significantly decreased by 1 μmol/l (-48.4%) and 10 μmol/l (-89.6%) sildenafil (n=10, p<0.05). This was not a cytotoxic effect, because cell viability was only reduced at sildenafil concentrations of 50 μmol/l or greater. In addition sildenafil significantly reduced endothelial proliferation induced by bFGF (n=10, p<0.05). The presented results demonstrate an antiangiogenic effect of sildenafil that might be useful in the prevention of atherosclerotic plaque vascularization. PMID:23675029

Intermittent individual housing increases survival of newly proliferated cells.

PubMed

Aberg, Elin; Pham, Therese M; Zwart, Mieke; Baumans, Vera; Brené, Stefan

2005-09-08

In this study, we analyzed how intermittent individual housing with or without a running wheel influenced corticosterone levels and survival of newly proliferated cells in the dentate gyrus of the hippocampus. Female Balb/c mice, in standard or enhanced housing, were divided into groups that were individually housed with or without running wheels on every second day. Intermittent individual housing without, but not with, running wheels increased survival of proliferated cells in the dentate gyrus as compared with continuous group housing in standard or enhanced conditions. Thus, changes in housing conditions on every second day can, under certain circumstances, have an impact on the survival of newly proliferated cells in the dentate gyrus.

Hypoxia enhances periodontal ligament stem cell proliferation via the MAPK signaling pathway.

PubMed

He, Y; Jian, C X; Zhang, H Y; Zhou, Y; Wu, X; Zhang, G; Tan, Y H

2016-11-21

There is high incidence of periodontal disease in high-altitude environments; hypoxia may influence the proliferation and clone-forming ability of periodontal ligament stem cells (PDLSCs). The MAPK signaling pathway is closely correlated with cell proliferation, differentiation, and apoptosis. Thus, we isolated and cultured PDLSCs under hypoxic conditions to clarify the impact of hypoxia on PDLSC proliferation and the underlying mechanism. PDLSCs were separated and purified by the limiting dilution method and identified by flow cytometry. PDLSCs were cultured under hypoxic or normoxic conditions to observe their cloning efficiency. PDLSC proliferation at different oxygen concentrations was evaluated by MTT assay. Expression of p38/MAPK and MAPK/ERK signaling pathway members was detected by western blotting. Inhibitors for p38/MAPK or ERK were applied to PDLSCs to observe their impacts on clone formation and proliferation. Isolated PDLSCs exhibited typical stem cell morphological characteristics, strong abilities of globular clone formation and proliferation, and upregulated expression of mesenchymal stem cell markers. Stem cell marker expression was not statistically different between PDLSCs cultured under hypoxia and normoxia (P > 0.05). The clone number in the hypoxia group was significantly higher than that in the control (P < 0.05). PDLSC proliferation under hypoxia was higher than that of the control (P < 0.001). p38 and ERK1/2 phosphorylation in hypoxic PDLSCs was markedly enhanced compared to that in the control (P < 0.05). Either P38/MAPK inhibitor or ERK inhibitor treatment reduced clone formation and proliferation. Therefore, hypoxia enhanced PDLSC clone formation and proliferation by activating the p38/MAPK and ERK/MAPK signaling pathways.

Melanosome uptake is associated with the proliferation and differentiation of keratinocytes.

PubMed

Choi, Hye-In; Sohn, Kyung-Cheol; Hong, Dong-Kyun; Lee, Young; Kim, Chang Deok; Yoon, Tae-Jin; Park, Jin Woon; Jung, Sunggyun; Lee, Jeung-Hoon; Lee, Young Ho

2014-01-01

Melanosomes are synthesized in melanocytes and transferred to neighboring keratinocytes. However, the associations of melanosome uptake with the proliferation and differentiation of keratinocytes are not fully understood. We examined the associations of melanosome uptake with keratinocyte differentiation and proliferation. SV40T-transformed human epidermal keratinocytes (SV-HEKs) were treated with isolated melanosomes. The effects of melanosome uptake on the proliferation and differentiation of the keratinocytes were analyzed by Western blotting and flow cytometry. The relationship between melanosome uptake and keratinocyte differentiation status was verified by determining the melanin content in the cells. Melanosomes reduced the proliferation of SV-HEKs in a dose-dependent manner, but did not induce differentiation. Melanosome uptake was higher in differentiating keratinocytes compared to non-differentiating keratinocytes, and inhibited significantly by PAR-2 inhibitor. Melanosomes inhibit keratinocyte proliferation. Moreover, melanosome uptake is influenced by keratinocyte differentiation status, being highest in mid-stage differentiating keratinocytes in a PAR-2 dependent manner.

Tight Junction–Associated Signaling Pathways Modulate Cell Proliferation in Uveal Melanoma

PubMed Central

Jayagopal, Ashwath; Yang, Jin-Long; Haselton, Frederick R.; Chang, Min S.

2011-01-01

Purpose. To investigate the role of tight junction (TJ)–associated signaling pathways in the proliferation of uveal melanoma. Methods. Human uveal melanoma cell lines overexpressing the TJ molecule blood vessel epicardial substance (Bves) were generated. The effects of Bves overexpression on TJ protein expression, cell proliferation, and cell cycle distribution were quantified. In addition, localization and transcription activity of the TJ-associated protein ZO-1–associated nucleic acid binding protein (ZONAB) were evaluated using immunofluorescence and bioluminescence reporter assays to study the involvement of Bves signaling in cell proliferation-associated pathways. Results. Bves overexpression in uveal melanoma cell lines resulted in increased expression of the TJ proteins occludin and ZO-1, reduced cell proliferation, and increased sequestration of ZONAB at TJs and reduced ZONAB transcriptional activity. Conclusions. TJ proteins are present in uveal melanoma, and TJ-associated signaling pathways modulate cell signaling pathways relevant to proliferation in uveal melanoma. PMID:20861479

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

Nandrolone decanoate is able to modulate proliferation and adhesion of myoblasts.

PubMed

Oliveira, E N; Fernandes, K P; Silva, C A; Oliveira, T S; Junior, J A; Bussadori, S K; Renno, A C; Mesquita-Ferrari, R A

2014-07-01

The search for a more efficient repair process of muscle injuries has become evident in clinical practice. The aim of the present study was to evaluate the effect of nandrolone decanoate (ND) on the proliferation, adhesion, and expression of myogenic regulatory factors (MRFs) in C2C12 cells.Methods. Cell proliferation and adhesion were assessed using an MTT assay. The expression of MRFs was assessed by real-time PCR.Results. ND applied at 10 or 25 µM concentration induced after 60 min an increase in adhesion, at 5 µM concentration induced after 5 days an increase in cell proliferation, and ND at 50 µM concentration led after 5 days to a decrease in cell proliferation in comparison with other groups. The steroid did not alter the expression of MRFs.Conclusions. The positive effects of ND regarding the proliferation and adhesion of C2C12 cells suggest that this steroid may have positive effects following a muscle injury.

Hyaluronic acid influence on platelet-induced airway smooth muscle cell proliferation.

PubMed

Svensson Holm, Ann-Charlotte B; Bengtsson, Torbjörn; Grenegård, Magnus; Lindström, Eva G

2012-03-10

Hyaluronic acid (HA) is one of the main components of the extracellular matrix (ECM) and is expressed throughout the body including the lung and mostly in areas surrounding proliferating and migrating cells. Furthermore, platelets have been implicated as important players in the airway remodelling process, e.g. due to their ability to induce airway smooth muscle cell (ASMC) proliferation. The aim of the present study was to investigate the role of HA, the HA-binding surface receptor CD44 and focal adhesion kinase (FAK) in platelet-induced ASMC proliferation. Proliferation of ASMC was measured using the MTS-assay, and we found that the CD44 blocking antibody and the HA synthase inhibitor 4-Methylumbelliferone (4-MU) significantly inhibited platelet-induced ASMC proliferation. The interaction between ASMC and platelets was studied by fluorescent staining of F-actin. In addition, the ability of ASMC to synthesise HA was investigated by fluorescent staining using biotinylated HA-binding protein and a streptavidin conjugate. We observed that ASMC produced HA and that a CD44 blocking antibody and 4-MU significantly inhibited platelet binding to the area surrounding the ASMC. Furthermore, the FAK-inhibitor PF 573228 inhibited platelet-induced ASMC proliferation. Co-culture of ASMC and platelets also resulted in increased phosphorylation of FAK as detected by Western blot analysis. In addition, 4-MU significantly inhibited the increased FAK-phosphorylation. In conclusion, our findings demonstrate that ECM has the ability to influence platelet-induced ASMC proliferation. Specifically, we propose that HA produced by ASMC is recognised by platelet CD44. The platelet/HA interaction is followed by FAK activation and increased proliferation of co-cultured ASMC. We also suggest that the mitogenic effect of platelets represents a potential important and novel mechanism that may contribute to airway remodelling. Copyright © 2011 Elsevier Inc. All rights reserved.

Norms in Conflict: Statecraft, Preventive Force, and Counter Proliferation

DTIC Science & Technology

2016-12-01

power. Finally, the ethical character of norms offers a framework for the attacking state to justify its actions to the international community ...national identity, sanctions, and ethics play in counter-proliferation strategies. Finally, it concludes by offering policy recommendations for...role that national identity, sanctions, and ethics play in counter-proliferation strategies. Finally, it concludes by offering policy

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

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

Fisetin regulates astrocyte migration and proliferation in vitro.

PubMed

Wang, Nan; Yao, Fang; Li, Ke; Zhang, Lanlan; Yin, Guo; Du, Mingjun; Wu, Bingyi

2017-04-01

Fisetin (3,3',4',7-tetrahydroxyflavone) is a plant flavonol found in fruits and vegetables that has been reported to inhibit migration and proliferation in several types of cancer. Reactive astrogliosis involves astrocyte migration and proliferation, and contributes to the formation of glial scars in central nervous system (CNS) disorders. However, the effect of fisetin on the migration and proliferation of astrocytes remains unclear. In this study, we found that fisetin inhibited astrocyte migration in a scratch-wound assay and diminished the phosphorylation of focal adhesion kinase (FAK; Tyr576/577 and paxillin (Tyr118). It also suppressed cell proliferation, as indicated by the decreased number of 5-ethynyl-2'-deoxyuridine (EdU)-positive cells, induced cell cycle arrest in the G1 phase, reduced the percentage of cells in the G2 and S phase (as measured by flow cytometry), and decreased cyclin D1 expression, but had no effect on apoptosis. Fisetin also decreased the phosphorylation levels of Akt and extracellular signal-regulated kinase (Erk)1/2, but had no effect on the phosphorylation of p38 mitogen-activated protein kinase (MAPK). These results indicate that fisetin inhibits aggressive cell phenotypes by suppressing cell migration and proliferation via the Akt/Erk signaling pathway. Fisetin may thus have potential for use as a therapeutic strategy targeting reactive astrocytes, which may lead to the inhibition of glial scar formation in vitro.

Phenolic Compounds in Extra Virgin Olive Oil Stimulate Human Osteoblastic Cell Proliferation.

PubMed

García-Martínez, Olga; De Luna-Bertos, Elvira; Ramos-Torrecillas, Javier; Ruiz, Concepción; Milia, Egle; Lorenzo, María Luisa; Jimenez, Brigida; Sánchez-Ortiz, Araceli; Rivas, Ana

2016-01-01

In this study, we aimed to clarify the effects of phenolic compounds and extracts from different extra virgin olive oil (EVOO) varieties obtained from fruits of different ripening stages on osteoblast cells (MG-63) proliferation. Cell proliferation was increased by hydroxytyrosol, luteolin, apigenin, p-coumaric, caffeic, and ferulic acids by approximately 11-16%, as compared with controls that were treated with one vehicle alone, while (+)-pinoresinol, oleuropein, sinapic, vanillic acid and derivative (vanillin) did not affect cell proliferation. All phenolic extracts stimulated MG-63 cell growth, and they induced higher cell proliferation rates than individual compounds. The most effective EVOO phenolic extracts were those obtained from the Picual variety, as they significantly increased cell proliferation by 18-22%. Conversely, Arbequina phenolic extracts increased cell proliferation by 9-13%. A decline in osteoblast proliferation was observed in oils obtained from olive fruits collected at the end of the harvest period, as their total phenolic content decreases at this late stage. Further research on the signaling pathways of olive oil phenolic compounds involved in the processes and their metabolism should be carried out to develop new interventions and adjuvant therapies using EVOO for bone health (i.e.osteoporosis) in adulthood and the elderly.

Phenolic Compounds in Extra Virgin Olive Oil Stimulate Human Osteoblastic Cell Proliferation

PubMed Central

García-Martínez, Olga; De Luna-Bertos, Elvira; Ramos-Torrecillas, Javier; Ruiz, Concepción; Milia, Egle; Lorenzo, María Luisa; Jimenez, Brigida; Sánchez-Ortiz, Araceli; Rivas, Ana

2016-01-01

In this study, we aimed to clarify the effects of phenolic compounds and extracts from different extra virgin olive oil (EVOO) varieties obtained from fruits of different ripening stages on osteoblast cells (MG-63) proliferation. Cell proliferation was increased by hydroxytyrosol, luteolin, apigenin, p-coumaric, caffeic, and ferulic acids by approximately 11–16%, as compared with controls that were treated with one vehicle alone, while (+)-pinoresinol, oleuropein, sinapic, vanillic acid and derivative (vanillin) did not affect cell proliferation. All phenolic extracts stimulated MG-63 cell growth, and they induced higher cell proliferation rates than individual compounds. The most effective EVOO phenolic extracts were those obtained from the Picual variety, as they significantly increased cell proliferation by 18–22%. Conversely, Arbequina phenolic extracts increased cell proliferation by 9–13%. A decline in osteoblast proliferation was observed in oils obtained from olive fruits collected at the end of the harvest period, as their total phenolic content decreases at this late stage. Further research on the signaling pathways of olive oil phenolic compounds involved in the processes and their metabolism should be carried out to develop new interventions and adjuvant therapies using EVOO for bone health (i.e.osteoporosis) in adulthood and the elderly. PMID:26930190

Detection of p53 mutations in proliferating vascular cells in glioblastoma multiforme.

PubMed

Kawasoe, Takuma; Takeshima, Hideo; Yamashita, Shinji; Mizuguchi, Sohei; Fukushima, Tsuyoshi; Yokogami, Kiyotaka; Yamasaki, Kouji

2015-02-01

Glioblastoma multiforme (GBM), one of the most aggressive tumors in humans, is highly angiogenic. However, treatment with the angiogenesis inhibitor bevacizumab has not significantly prolonged overall patient survival times. GBM resistance to angiogenesis inhibitors is attributed to multiple interacting mechanisms. Although mesenchymal transition via glioma stem-like cells has attracted attention, it is considered a poor biomarker. There is no simple method for differentiating tumor-derived and reactive vascular cells from normal cells. The authors attempted to detect the mesenchymal transition of tumor cells by means of p53 and isocitrate dehydrogenase 1 (IDH1) immunohistochemistry. Using antibody against p53 and IDH1 R132H, the authors immunohistochemically analyzed GBM tissue from patients who had undergone surgery at the University of Miyazaki Hospital during August 2005-December 2011. They focused on microvascular proliferation with a p53-positive ratio exceeding 50%. They compared TP53 mutations in original tumor tissues and in p53-positive and p53-negative microvascular proliferation cells collected by laser microdissection. Among 61 enrolled GBM patients, the first screening step (immunostaining) identified 46 GBMs as p53 positive, 3 of which manifested areas of prominent p53-positive microvascular proliferation (>50%). Histologically, areas of p53-positive microvascular proliferation tended to be clustered, and they coexisted with areas of p53-negative microvascular proliferation. Both types of microvascular proliferation cells were clearly separated from original tumor cells by glial fibrillary acidic protein, epidermal growth factor receptor, and low-/high-molecular-weight cytokeratin. DNA sequencing analysis disclosed that p53-positive microvascular proliferation cells exhibited TP53 mutations identical to those observed in the original tumor; p53-negative microvascular proliferation cells contained a normal allele. Although immunostaining indicated

JPRS Report, Proliferation Issues

DTIC Science & Technology

1992-09-23

reactor with earlier United Nations specialists arriving into the dis- limited capability from an Argentine specialist company puted area had found no...DEPARTMENT OF COMMERCE NATIONAL TECHNICAL INFORMATION SERVICE SPRINGFIELD, VA 22161 PROLIFERATION ISSUES JPRS-TND-92-035 CONTENTS 23 September 1992...thought that joining this treaty would constitute a sort of given national resource. impediment to the commercialization of Niger’s ura- [Ouhoumoudou

Clinicopathological and immunohistochemical characterization of papillary proliferation of the endometrium: A single institutional experience.

PubMed

Park, Cheol Keun; Yoon, Gun; Cho, Yoon Ah; Kim, Hyun-Soo

2016-06-28

Papillary proliferation of the endometrium is an unusual lesion that is composed of papillae with fibrovascular stromal cores covered with benign-appearing glandular epithelium. We studied the clinicopathological and immunohistochemical features of four cases of endometrial papillary proliferations. All patients were postmenopausal. Two lesions were incidental findings in hysterectomy specimens, and two lesions were detected in endometrial curettage specimens. Based on the degree of architectural complexity and extent of proliferation, we classified papillary proliferations histopathologically into "simple" or "complex" growth patterns. Three cases were classified as simple papillary proliferation, and one case was classified as complex papillary proliferation. Simple papillary proliferations were characterized by slender papillae with delicate stromal cores. In contrast, complex papillary proliferations had intracystic papillary projections and cellular clusters with frequent branching and occasional cytological atypia. All cases showed coexistent metaplastic epithelial changes, including mucinous metaplasia, eosinophilic cell change, and ciliated cell metaplasia. One patient with simple papillary proliferations had coexistent well-differentiated endometrioid carcinoma. One patient had subsequent hyperplasia without atypia, and another patient had subsequent atypical hyperplasia/endometrioid intraepithelial neoplasia; both patients underwent total hysterectomy within four months. Our observations are consistent with previous data demonstrating that endometrial papillary proliferations coexist with or develop into atypical hyperplasia/endometrioid intraepithelial neoplasia or endometrioid carcinoma. It is very important for pathologists to discriminate papillary proliferations from neoplastic lesions (including atypical hyperplasia/endometrioid intraepithelial neoplasia and well-differentiated endometrioid carcinoma) and benign mimickers (including papillary

Clinicopathological and immunohistochemical characterization of papillary proliferation of the endometrium: A single institutional experience

PubMed Central

Park, Cheol Keun; Yoon, Gun; Cho, Yoon Ah; Kim, Hyun-Soo

2016-01-01

Papillary proliferation of the endometrium is an unusual lesion that is composed of papillae with fibrovascular stromal cores covered with benign-appearing glandular epithelium. We studied the clinicopathological and immunohistochemical features of four cases of endometrial papillary proliferations. All patients were postmenopausal. Two lesions were incidental findings in hysterectomy specimens, and two lesions were detected in endometrial curettage specimens. Based on the degree of architectural complexity and extent of proliferation, we classified papillary proliferations histopathologically into “simple” or “complex” growth patterns. Three cases were classified as simple papillary proliferation, and one case was classified as complex papillary proliferation. Simple papillary proliferations were characterized by slender papillae with delicate stromal cores. In contrast, complex papillary proliferations had intracystic papillary projections and cellular clusters with frequent branching and occasional cytological atypia. All cases showed coexistent metaplastic epithelial changes, including mucinous metaplasia, eosinophilic cell change, and ciliated cell metaplasia. One patient with simple papillary proliferations had coexistent well-differentiated endometrioid carcinoma. One patient had subsequent hyperplasia without atypia, and another patient had subsequent atypical hyperplasia/endometrioid intraepithelial neoplasia; both patients underwent total hysterectomy within four months. Our observations are consistent with previous data demonstrating that endometrial papillary proliferations coexist with or develop into atypical hyperplasia/endometrioid intraepithelial neoplasia or endometrioid carcinoma. It is very important for pathologists to discriminate papillary proliferations from neoplastic lesions (including atypical hyperplasia/endometrioid intraepithelial neoplasia and well-differentiated endometrioid carcinoma) and benign mimickers (including

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...

Osthole inhibits proliferation and induces apoptosis in human osteosarcoma cells.

PubMed

Ding, Yong; Lu, Xiongwei; Hu, Xiaopeng; Ma, Jie; Ding, Huan

2014-02-01

The purpose of this study was to investigate the effect of osthole on osteosarcoma cell proliferation and apoptosis. Cell counting Kit-8 assay was performed to establish the effects of osthole on osteosarcoma MG-63 cell proliferation. Annexin V-FITC/PI was performed to analyze the apoptotic rate of the cells. The inhibitory effects of osthole on the expression of BCL-2, BAX, and caspase-3 were detected by Western blotting. Osthole inhibited the growth of human osteosarcoma MG-63 cells by inhibiting cell proliferation and induced cell apoptosis. Western blotting demonstrated that osthole downregulated the expressions of BCL-2 and caspase-3 and upregulated the expression of BAX in human osteosarcoma cells. Osthole can inhibit osteosarcoma cell proliferation and induced apoptosis effectively in a dose-dependent manner through downregulating the expression of BCL-2 and caspase-3 proteins levels and upregulating the expression of BAX proteins levels.

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

Cold thyroid nodules show a marked increase in proliferation markers.

PubMed

Krohn, Knut; Stricker, Ingo; Emmrich, Peter; Paschke, Ralf

2003-06-01

Thyroid follicular adenomas and adenomatous thyroid nodules are a frequent finding in geographical areas with iodine deficiency. They occur as hypofunctioning (scintigraphically cold) or hyperfunctioning (scintigraphically hot) nodules. Their predominant clonal origin suggests that they result from clonal expansion of a single cell, which is very likely the result of a prolonged increase in proliferation compared with non-affected surrounding cells. To test whether increased cell proliferation is detectable in cold thyroid nodules, we studied paraffin-embedded tissue from 40 cold thyroid nodules and their surrounding normal thyroid tissue for the occurrence of the proliferating cell nuclear antigen (PCNA) and Ki-67 (MIB-1 antibody) epitopes as markers for cell proliferation. All 40 thyroid nodules were histologically well characterized and have been studied for molecular characteristics before. The labeling index (number of labeled cells versus total cell number) for nodular and surrounding tissue was calculated. In 33 cold thyroid nodules a significant (p < or = 0.05) increase in the labeling index for PCNA was detectable. In 19 cold thyroid nodules a significant (p < or = 0.05) increase in the labeling index for Ki-67 was detectable. Moreover, surrounding tissues with lymphocyte infiltration showed a significantly higher labeling index for both PCNA and Ki-67 compared with normal surrounding tissue. These findings are first evidence that an increased thyroid epithelial cell proliferation is a uniform feature common to most cold nodules. However, the increase of proliferation markers shows a heterogeneity that is not correlated with histopathologic, molecular, or clinical characteristics.

Hyaluronan Does Not Regulate Human Epidermal Keratinocyte Proliferation and Differentiation*

PubMed Central

Malaisse, Jérémy; Pendaries, Valérie; Hontoir, Fanny; De Glas, Valérie; Van Vlaender, Daniel; Simon, Michel; Lambert de Rouvroit, Catherine; Poumay, Yves; Flamion, Bruno

2016-01-01

Hyaluronan (HA) is synthesized by three HA synthases (HAS1, HAS2, and HAS3) and secreted in the extracellular matrix. In human skin, large amounts of HA are found in the dermis. HA is also synthesized by keratinocytes in the epidermis, although its epidermal functions are not clearly identified yet. To investigate HA functions, we studied the effects of HA depletion on human keratinocyte physiology within in vitro reconstructed human epidermis. Inhibition of HA synthesis with 4-methylumbelliferone (4MU) did not modify the expression profile of the epidermal differentiation markers involucrin, keratin 10, and filaggrin during tissue reconstruction. In contrast, when keratinocytes were incubated with 4MU, cell proliferation was decreased. In an attempt to rescue the proliferation function, HA samples of various mean molecular masses were added to keratinocyte cultures treated with 4MU. These samples were unable to rescue the initial proliferation rate. Furthermore, treatments with HA-specific hyaluronidase, although removing almost all HA from keratinocyte cultures, did not alter the differentiation or proliferation processes. The differences between 4MU and hyaluronidase effects did not result from differences in intracellular HA, sulfated glycosaminoglycan concentration, apoptosis, or levels of HA receptors, all of which remained unchanged. Similarly, knockdown of UDP-glucose 6-dehydrogenase (UGDH) using lentiviral shRNA effectively decreased HA production but did not affect proliferation rate. Overall, these data suggest that HA levels in the human epidermis are not directly correlated with keratinocyte proliferation and differentiation and that incubation of cells with 4MU cannot equate with HA removal. PMID:26627828

GPNMB promotes proliferation of developing eosinophils.

PubMed

Hwang, Sae Mi; Kang, Jin Hyun; Kim, Bo Kyum; Uhm, Tae Gi; Kim, Hye Jeong; Lee, Hyune-Hwan; Binas, Bert; Chung, Il Yup

2017-08-01

Glycoprotein non-metastatic melanoma protein B (GPNMB) is a type I transmembrane protein that is expressed in a wide variety of cell types, including haematopoietic lineages. We previously demonstrated that GPNMB is one of the most highly expressed genes at an early and intermediate stage of eosinophil development. We herein examined GPNMB expression and its possible functional effect using cord blood (CB) CD34+ haematopoietic stem cells differentiating toward eosinophils during a 24-day culture period. Western blot and confocal microscopy analyses showed that GPNMB reached its highest levels at day 12 with most GPNMB-positive cells also expressing major basic protein 1 (MBP1), an eosinophil granule protein. GPNMB declined thereafter, but was still present at an appreciable level at day 24, the time when CB eosinophils most abundantly expressed MBP1 and were thus considered fully differentiated. When the developing CB cells were cultured in the presence of a blocking anti-GPNMB antibody, cell proliferation was significantly reduced. In agreement, ectopic expression of GPNMB in heterologous cells resulted in a significant increase in cell proliferation, while small interfering RNA of GPNMB inhibited the GPNMB-mediated proliferation. Thus, GPNMB is expressed in a temporal manner during eosinophil development and delivers a proliferative signal upon activation. © The Authors 2017. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.

Low oxygen level increases proliferation and metabolic changes in bovine granulosa cells.

PubMed

Shiratsuki, Shogo; Hara, Tomotaka; Munakata, Yasuhisa; Shirasuna, Koumei; Kuwayama, Takehito; Iwata, Hisataka

2016-12-05

The present study addresses molecular backgrounds underlying low oxygen induced metabolic changes and 1.2-fold change in bovine granulosa cell (GCs) proliferation. RNA-seq revealed that low oxygen (5%) upregulated genes associated with HIF-1 and glycolysis and downregulated genes associated with mitochondrial respiration than that in high oxygen level (21%). Low oxygen level induced high glycolytic activity and low mitochondrial function and biogenesis. Low oxygen level enhanced GC proliferation with high expression levels of HIF-1, VEGF, AKT, mTOR, and S6RP, whereas addition of anti-VEGF antibody decreased cellular proliferation with low phosphorylated AKT and mTOR expression levels. Low oxygen level reduced SIRT1, whereas activation of SIRT1 by resveratrol increased mitochondrial replication and decreased cellular proliferation with reduction of phosphorylated mTOR. These results suggest that low oxygen level stimulates the HIF1-VEGF-AKT-mTOR pathway and up-regulates glycolysis, which contributes to GC proliferation, and downregulation of SIRT1 contributes to hypoxia-associated reduction of mitochondria and cellular proliferation. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

The forms and mechanisms of stress proliferation: the case of AIDS caregivers.

PubMed

Pearlin, L I; Aneshensel, C S; LeBlanc, A J

1997-09-01

Processes of stress proliferation are explored in a sample of informal caregivers to people with AIDS. Proliferation refers to the tendency for stressors to beget stressors. Two forms of proliferation are explored, each based on the distinction between primary and secondary stressors. Among AIDS caregivers, primary stressors are the hardships rooted in the caregiving role. Secondary stressors result from primary stressors, but arise in roles and activities outside of caregiving. One form of proliferation is the expansion of primary stressors, reflected in an increase in role overload and a growing sense of being a captive of the caregiver role. Expansion is largely driven by the course of AIDS and the elevation of demands it places on the caregiver. The second form of proliferation is the surfacing of secondary stressors in social and leisure life and in the occupational realm. This form arises from the strains imposed by the emerging caregiver role on the other roles and activities of the caregiver. It is proposed that the systematic assessment of proliferated stressors can help illuminate the dynamic connections between stress and health.

Black cohosh inhibits 17β-estradiol-induced cell proliferation of endometrial adenocarcinoma cells.

PubMed

Park, So Yun; Kim, Hee Ja; Lee, Sa Ra; Choi, Youn-Hee; Jeong, Kyungah; Chung, Hyewon

2016-10-01

This study was conducted to investigate the effect of black cohosh (BC) extract on the proliferation and apoptosis of Ishikawa cells. Ishikawa human endometrial adenocarcinoma cells were treated with or without BC (1, 5, 10 and 25 μM) and cell proliferation and cytotoxicity were measured by CCK-8 assays and flow cytometry analysis. Additionally, Ishikawa cells were treated with 17β-estradiol (E2), E2 + progesterone and E2 + BC (5 and 10 μM) and the effect of BC and progesterone on E2-induced cell proliferation was analyzed. BC decreased the proliferation of Ishikawa cells at a dose-dependent rate compared with the control group (p < 0.05). The proliferation of Ishikawa cells increased in the presence of E2, whereas the subsequent addition of progesterone or BC decreased proliferation to the level of the control group (p < 0.05). The inhibitory effect of BC on E2-induced cell proliferation was greater than the inhibitory effect of progesterone. In conclusion, BC induces apoptosis in Ishikawa cells and suppresses E2-induced cell proliferation in Ishikawa cells. BC could be considered a candidate co-treatment agent of estrogen-dependent tumors, especially those involving endometrial cells.

Effects of weightlessness on tissue proliferation

NASA Technical Reports Server (NTRS)

Crosby, W. H.; Tavassoli, M.

1975-01-01

The repair of bone marrow stroma following mechanical injury was studied to obtain baseline data for a proposed space experiment regarding the effect of weightlessness on marrow stroma and other proliferating cell systems.

Legionella pneumophila prevents proliferation of its natural host Acanthamoeba castellanii

PubMed Central

Mengue, Luce; Régnacq, Matthieu; Aucher, Willy; Portier, Emilie; Héchard, Yann; Samba-Louaka, Ascel

2016-01-01

Legionella pneumophila is a ubiquitous, pathogenic, Gram-negative bacterium responsible for legionellosis. Like many other amoeba-resistant microorganisms, L. pneumophila resists host clearance and multiplies inside the cell. Through its Dot/Icm type IV secretion system, the bacterium injects more than three hundred effectors that modulate host cell physiology in order to promote its own intracellular replication. Here we report that L. pneumophila prevents proliferation of its natural host Acanthamoeba castellanii. Infected amoebae could not undergo DNA replication and no cell division was observed. The Dot/Icm secretion system was necessary for L. pneumophila to prevent the eukaryotic proliferation. The absence of proliferation was associated with altered amoebal morphology and with a decrease of mRNA transcript levels of CDC2b, a putative regulator of the A. castellanii cell cycle. Complementation of CDC28-deficient Saccharomyces cerevisiae by the CDC2b cDNA was sufficient to restore proliferation of CDC28-deficient S. cerevisiae and suggests for the first time that CDC2b from A. castellanii could be functional and a bona fide cyclin-dependent kinase. Hence, our results reveal that L. pneumophila impairs proliferation of A. castellanii and this effect could involve the cell cycle protein CDC2b. PMID:27805070

Dedifferentiation, Proliferation, and Redifferentiation of Adult Mammalian Cardiomyocytes After Ischemic Injury.

PubMed

Wang, Wei Eric; Li, Liangpeng; Xia, Xuewei; Fu, Wenbin; Liao, Qiao; Lan, Cong; Yang, Dezhong; Chen, Hongmei; Yue, Rongchuan; Zeng, Cindy; Zhou, Lin; Zhou, Bin; Duan, Dayue Darrel; Chen, Xiongwen; Houser, Steven R; Zeng, Chunyu

2017-08-29

Adult mammalian hearts have a limited ability to generate new cardiomyocytes. Proliferation of existing adult cardiomyocytes (ACMs) is a potential source of new cardiomyocytes. Understanding the fundamental biology of ACM proliferation could be of great clinical significance for treating myocardial infarction (MI). We aim to understand the process and regulation of ACM proliferation and its role in new cardiomyocyte formation of post-MI mouse hearts. β-Actin-green fluorescent protein transgenic mice and fate-mapping Myh6-MerCreMer-tdTomato/lacZ mice were used to trace the fate of ACMs. In a coculture system with neonatal rat ventricular myocytes, ACM proliferation was documented with clear evidence of cytokinesis observed with time-lapse imaging. Cardiomyocyte proliferation in the adult mouse post-MI heart was detected by cell cycle markers and 5-ethynyl-2-deoxyuridine incorporation analysis. Echocardiography was used to measure cardiac function, and histology was performed to determine infarction size. In vitro, mononucleated and bi/multinucleated ACMs were able to proliferate at a similar rate (7.0%) in the coculture. Dedifferentiation proceeded ACM proliferation, which was followed by redifferentiation. Redifferentiation was essential to endow the daughter cells with cardiomyocyte contractile function. Intercellular propagation of Ca 2+ from contracting neonatal rat ventricular myocytes into ACM daughter cells was required to activate the Ca 2+ -dependent calcineurin-nuclear factor of activated T-cell signaling pathway to induce ACM redifferentiation. The properties of neonatal rat ventricular myocyte Ca 2+ transients influenced the rate of ACM redifferentiation. Hypoxia impaired the function of gap junctions by dephosphorylating its component protein connexin 43, the major mediator of intercellular Ca 2+ propagation between cardiomyocytes, thereby impairing ACM redifferentiation. In vivo, ACM proliferation was found primarily in the MI border zone. An ischemia

Effect of irradiation on human T-cell proliferation: low dose irradiation stimulates mitogen-induced proliferation and function of the suppressor/cytotoxic T-cell subset.

PubMed

Gualde, N; Goodwin, J S

1984-04-01

Unfractionated human T cells exposed to 10-50 rad of X irradiation incorporated less [3H]thymidine than nonirradiated T cells when subsequently cultured with PHA or Con A. The cytotoxic/suppressor T-cell subset, isolated as either OKT8(+) or OKT4(-) cells, demonstrated significantly enhanced [3H]thymidine incorporation in PHA- or Con A-stimulated cultures after exposure to 10-50 rad, compared to unirradiated cells, while the proliferation of the OKT4(+) helper/inducer subset was inhibited by low dose irradiation. It has been previously reported that approximately 30% of the cytotoxic/suppressor subset also stains with OKM1. When the cytotoxic/suppressor subset was further subdivided into OKT4(-), OKM1(+), and OKT4(-), OKM1(-) cells, proliferation of the OKT4(-), OKM1(+) population was inhibited by exposure to 25 rad while proliferation of the OKT4(-), OKM1(-) population was stimulated. The increase in proliferation of the cytotoxic/suppressor T-cell subset after low dose irradiation is paralleled by an increase in suppressor activity of these cells. T cells exposed to 25 rad and then cultured with Con A for 48 hr caused greater inhibition of IgG production when added to fresh autologous lymphocytes stimulated by pokeweed mitogen than did unirradiated cells. Thus, low dose irradiation enhances both the proliferation and function of the human suppressor T-cell subset.

BCOR regulates myeloid cell proliferation and differentiation

PubMed Central

Cao, Qi; Gearhart, Micah D.; Gery, Sigal; Shojaee, Seyedmehdi; Yang, Henry; Sun, Haibo; Lin, De-chen; Bai, Jing-wen; Mead, Monica; Zhao, Zhiqiang; Chen, Qi; Chien, Wen-wen; Alkan, Serhan; Alpermann, Tamara; Haferlach, Torsten; Müschen, Markus; Bardwell, Vivian J.; Koeffler, H. Phillip

2016-01-01

BCOR is a component of a variant Polycomb group repressive complex 1 (PRC1). Recently, we and others reported recurrent somatic BCOR loss-of-function mutations in myelodysplastic syndrome and acute myelogenous leukaemia (AML). However, the role of BCOR in normal hematopoiesis is largely unknown. Here, we explored the function of BCOR in myeloid cells using myeloid murine models with Bcor conditional loss-of-function or overexpression alleles. Bcor mutant bone marrow cells showed significantly higher proliferation and differentiation rates with upregulated expression of Hox genes. Mutation of Bcor reduced protein levels of RING1B, an H2A ubiquitin ligase subunit of PRC1 family complexes and reduced H2AK119ub upstream of upregulated HoxA genes. Global RNA expression profiling in murine cells and AML patient samples with BCOR loss-of-function mutation suggested that loss of BCOR expression is associated with enhanced cell proliferation and myeloid differentiation. Our results strongly suggest that BCOR plays an indispensable role in hematopoiesis by inhibiting myeloid cell proliferation and differentiation and offer a mechanistic explanation for how BCOR regulates gene expression such as Hox genes. PMID:26847029

Peroxisome proliferators induce apoptosis in hepatoma cells.

PubMed

Canuto, R A; Muzio, G; Bonelli, G; Maggiora, M; Autelli, R; Barbiero, G; Costelli, P; Brossa, O; Baccino, F M

1998-01-01

In the AH-130 hepatoma, a poorly differentiated tumor, maintained by weekly transplantations in rats, a low percentage of cells spontaneously underwent apoptosis, mainly during the transition from logarithmic- to stationary-growth phase. It was possible to induce massive apoptosis of cells by treating them with clofibrate, a peroxisome proliferator and hypolipidemic drug. Similar results were obtained with HepG2 cells. With 1 mM clofibrate, apoptosis began to manifest itself after 1 h of treatment in vitro, and was assessed by morphological analysis, by DNA fragmentation carried out with agarose gel electrophoresis, and with flow cytometric determination of terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling. The mechanisms whereby clofibrate induces apoptosis are still unclear. Since the peroxisome proliferator-activated receptor was expressed at a very low level and was not stimulated by clofibrate in the AH-130 hepatoma cells, its involvement seems unlikely. Moreover, lipid peroxidation was not increased after clofibrate treatment. Phospholipids and cholesterol were significantly decreased. The decreased cholesterol content might suggest an inhibition of the mevalonate pathway and, therefore, of isoprenylation of proteins involved in cell proliferation.

Lensless imaging system to quantify cell proliferation

NASA Astrophysics Data System (ADS)

Vinjimore Kesavan, S.; Allier, C. P.; Navarro, F.; Mittler, F.; Chalmond, B.; Dinten, J.-M.

2013-02-01

Owing to its simplicity, lensless imaging system is adept at continuous monitoring of adherent cells inside the incubator. The setup consists of a CMOS sensor with pixel pitch of 2.2 μm and field of view of 24 mm2, LED with a dominating wavelength of 525 nm, along with a pinhole of 150 μm as the source of illumination. The in-line hologram obtained from cells depends on the degree of cell-substrate adhesion. Drastic difference is observed between the holographic patterns of floating and adherent cells. In addition, the well-established fact of reduction of cell-substrate contact during cell division is observed with our system based on corresponding spontaneous transition in the holographic pattern. Here, we demonstrate that by recognizing this specific holographic pattern, number of cells undergoing mitosis in a cell culture with a population of approximately 5000 cells, can be estimated in real-time. The method is assessed on comparison with Edu-based proliferation assay. The approach is straightforward and it eliminates the use of markers to estimate the proliferation rate of a given cell culture. Unlike most proliferation assays, the cells are not harvested enabling continuous monitoring of cell culture.

Novel T lymphocyte proliferation assessment using whole mouse cryo-imaging

NASA Astrophysics Data System (ADS)

Wuttisarnwattana, Patiwet; Raza, Syed A.; Eid, Saada; Cooke, Kenneth R.; Wilson, David L.

2014-03-01

New imaging technologies enable one to assess T-cell proliferation, an important feature of the immunological response. However, none of the traditional imaging modalities allow one to examine quantiatively T-cell function with microscopic resolution and single cell sensitivity over an entire mouse. To address this need, we established T-cells proliferation assays using 3D microscopic cryo-imaging. Assays include: (1) biodistribution of T-cells, (2) secondary lymphoid organ (SLO) volume measurement, (3) carboxyfluorescein succinimidyl ester (CFSE) dilution per cell as cells divide. To demonstrate the application, a graft-versus-host-disease (GVHD) model was used. 3D visualization show that T-cells specifically homed to the SLOs (spleen and lymph nodes) as well as GVHD target organs (such as GI-tract, liver, skin and thymus).The spleen was chosen as representative of the SLOs. For spleen size analysis, volumes of red and white pulp were measured. Spleen volumes of the allogeneic mice (with GVHD) were significantly larger than those of the syngeneic mice (without GVHD) at 72 to 120 hours post-transplant. For CFSE dilution approach, we employed color-coded volume rendering and probability density function (PDF) of single cell intensity to assess T-cell proliferation in the spleen. As compared to syngeneic T-cells, the allogeneic T-cells quickly aggregated in the spleen as indicated by increasing of CFSE signal over the first 48 hours. Then they rapidly proliferated as evidenced by reduced CFSE intensity (at 48-96 hours). Results suggest that assays can be used to study GVHD treatments using T-cell proliferation and biodistibution as assays. In summary, this is the first time that we are able to track and visualize T-cells in whole mouse with single cell sensitivity. We believe that our technique can be an alternative choice to traditional in vitro immunological proliferation assays by providing assessment of proliferation in an in vivo model.

Mechanisms of decreased intestinal epithelial proliferation and increased apoptosis in murine acute lung injury.

PubMed

Husain, Kareem D; Stromberg, Paul E; Woolsey, Cheryl A; Turnbull, Isaiah R; Dunne, W Michael; Javadi, Pardis; Buchman, Timothy G; Karl, Irene E; Hotchkiss, Richard S; Coopersmith, Craig M

2005-10-01

The aim of this study was to determine the effects of acute lung injury on the gut epithelium and examine mechanisms underlying changes in crypt proliferation and apoptosis. The relationship between severity and timing of lung injury to intestinal pathology was also examined. Randomized, controlled study. University research laboratory. Genetically inbred mice. Following induction of acute lung injury, gut epithelial proliferation and apoptosis were assessed in a) C3H/HeN wild-type and C3H/HeJ mice, which lack functional Toll-like receptor 4 (n = 17); b) C57Bl/6 mice that received monoclonal anti-tumor necrosis factor-alpha or control antibody (n = 22); and c) C57Bl/6 wild-type and transgenic mice that overexpress Bcl-2 in their gut epithelium (n = 21). Intestinal epithelial proliferation and death were also examined in animals with differing degrees of lung inflammation (n = 24) as well as in a time course analysis following a fixed injury (n = 18). Acute lung injury caused decreased proliferation and increased apoptosis in crypt epithelial cells in all animals studied. C3H/HeJ mice had higher levels of proliferation than C3H/HeN animals without additional changes in apoptosis. Anti-tumor necrosis factor-alpha antibody had no effect on gut epithelial proliferation or death. Overexpression of Bcl-2 did not change proliferation despite decreasing gut apoptosis. Proliferation and apoptosis were not correlated to severity of lung injury, as gut alterations were lost in mice with more severe acute lung injury. Changes in both gut epithelial proliferation and death were apparent within 12 hrs, but proliferation was decreased 36 hrs following acute lung injury while apoptosis returned to normal. Acute lung injury causes disparate effects on crypt proliferation and apoptosis, which occur, at least in part, through differing mechanisms involving Toll-like receptor 4 and Bcl-2. Severity of lung injury does not correlate with perturbations in proliferation or death in the

Mechanisms of decreased intestinal epithelial proliferation and increased apoptosis in murine acute lung injury

PubMed Central

Husain, Kareem D.; Stromberg, Paul E.; Woolsey, Cheryl A.; Turnbull, Isaiah R.; Dunne, W. Michael; Javadi, Pardis; Buchman, Timothy G.; Karl, Irene E.; Hotchkiss, Richard S.; Coopersmith, Craig M.

2005-01-01

Objectives The aim of this study was to determine the effects of acute lung injury (ALI) on the gut epithelium and examine mechanisms underlying changes in crypt proliferation and apoptosis. The relationship between severity and timing of lung injury to intestinal pathology was also examined. Design Randomized, controlled study. Setting University research laboratory. Subjects Genetically inbred mice. Interventions Following induction of ALI, gut epithelial proliferation and apoptosis was assessed in a) C3H/HeN wild type and C3H/HeJ mice, that lack functional toll-like receptor 4 (TLR4, n=17), b) C57Bl/6 mice that received monoclonal anti-tumor necrosis factor-α (TNFα) or control antibody (n=22) and c) C57Bl/6 wild type and transgenic mice that overexpress Bcl-2 in their gut epithelium (n=21). Intestinal epithelial proliferation and death were also examined in animals with differing degrees of lung inflammation (n=24) as well as in a timecourse analysis following a fixed injury (n=18). Measurements and Main Results ALI caused decreased proliferation and increased apoptosis in crypt epithelial cells in all animals studied. C3H/HeJ mice had higher levels of proliferation than C3H/HeN animals without additional changes in apoptosis. Anti-TNFα antibody had no effect on gut epithelial proliferation or death. Overexpression of Bcl-2 did not change proliferation despite decreasing gut apoptosis. Proliferation and apoptosis were not correlated to severity of lung injury, as gut alterations were lost in mice with more severe ALI. Changes in both gut epithelial proliferation and death were apparent within 12 hours, but proliferation was decreased 36 hours following ALI while apoptosis returned to normal. Conclusions ALI causes disparate effects on crypt proliferation and apoptosis, which occur, at least in part, through differing mechanisms involving TLR4 and Bcl-2. Severity of lung injury does not correlate with perturbations in proliferation or death in the gut

Dpp signaling inhibits proliferation in the Drosophila wing by Omb-dependent regional control of bantam.

PubMed

Zhang, Xubo; Luo, Dan; Pflugfelder, Gert O; Shen, Jie

2013-07-01

The control of organ growth is a fundamental aspect of animal development but remains poorly understood. The morphogen Dpp has long been considered as a general promoter of cell proliferation during Drosophila wing development. It is an ongoing debate whether the Dpp gradient is required for the uniform cell proliferation observed in the wing imaginal disc. Here, we investigated how the Dpp signaling pathway regulates proliferation during wing development. By systematic manipulation of Dpp signaling we observed that it controls proliferation in a region-specific manner: Dpp, via omb, promoted proliferation in the lateral and repressed proliferation in the medial wing disc. Omb controlled the regional proliferation rate by oppositely regulating transcription of the microRNA gene bantam in medial versus lateral wing disc. However, neither the Dpp nor Omb gradient was essential for uniform proliferation along the anteroposterior axis.

SOX15 regulates proliferation and migration of endometrial cancer cells.

PubMed

Rui, Xiaohui; Xu, Yun; Jiang, Xiping; Guo, Caixia; Jiang, Jingting

2017-10-31

The study aimed to investigate the effects of Sry-like high mobility group box 15 ( SOX15 ) on proliferation and migration of endometrial cancer (EC) cells. Immunohistochemistry (IHC) was applied to determine the expression of SOX15 in EC tissues and adjacent tissues. We used cell transfection method to construct the HEC-1-A and Ishikawa cell lines with stable overexpression and low expression SOX15 Reverse-transcription quantitative real-time PCR (RT-qPCR) and Western blot were performed to examine expression of SOX15 mRNA and SOX15 protein, respectively. By conducting a series of cell proliferation assay and migration assay, we analyzed the influence of SOX15 overexpression or low expression on EC cell proliferation and migration. The expression of SOX15 mRNA and protein in EC tissues was significantly lower than that in adjacent tissues. After lentivirus-transfecting SOX15 , the expression level of SOX15 mRNA and protein was significantly increased in cells of SOX15 group, and decreased in sh- SOX15 group. Overexpression of SOX15 could suppress cell proliferation, while down-regulation of SOX15 increased cell proliferation. Flow cytometry results indicated that overexpression of SOX15 induced the ratio of cell-cycle arrest in G 1 stage. In addition, Transwell migration assay results showed that SOX15 overexpression significantly inhibited cell migration, and also down-regulation of SOX15 promoted the migration. As a whole, SOX15 could regulate the proliferation and migration of EC cells and up- regulation of SOX15 could be valuable for EC treatment. © 2017 The Author(s).

Genistein effects on stromal cells determines epithelial proliferation in endometrial co-cultures.

PubMed

Sampey, Brante P; Lewis, Terrence D; Barbier, Claire S; Makowski, Liza; Kaufman, David G

2011-06-01

Estrogen is the leading etiologic factor for endometrial cancer. Estrogen-induced proliferation of endometrial epithelial cells normally requires paracrine growth factors produced by stromal cells. Epidemiologic evidence indicates that dietary soy prevents endometrial cancer, and implicates the phytoestrogen genistein in this effect. However, results from previous studies are conflicting regarding the effects of genistein on hormone responsive cancers. The effects of estrogen and genistein on proliferation of Ishikawa (IK) endometrial adenocarcinoma cells were examined in co-cultures of IK cells with endometrial stromal cells, recapitulating the heterotypic cell-to-cell interactions observed in vivo. The roles of estrogen receptor (ER)α and ERβ were evaluated using ERα and ERβ specific agonists. ER activation and cell proliferation in the IK epithelial cells were determined by alkaline phosphatase assay and Coulter counter enumeration, respectively. Both estrogen and genistein increased estrogen receptor-induced gene activity in IK cells over a range of concentrations. Estrogen alone but not genistein increased IK proliferation in co-cultures. When primed by estrogen treatment, increasing concentrations of genistein produced a biphasic effect on IK proliferation: nM concentrations inhibited estrogen-induced proliferation while μM concentrations increased proliferation. Studies with an ERβ-specific agonist produced similar results. Genistein did not influence the effects of estrogen on IK proliferation in monoculture. Our study indicates that nutritionally relevant concentrations (nM) of genistein inhibit the proliferative effects of estrogen on endometrial adenocarcinoma cells presumably through activation of stromal cell ERβ. We believe that sub-micromolar concentrations of genistein may represent a novel adjuvant for endometrial cancer treatment and prevention. Copyright © 2011 Elsevier Inc. All rights reserved.

Effects of glucocorticoid hormones on cell proliferation in dimethylhydrazine-induced tumours in rat colon.

PubMed

Tutton, P J; Barkla, D H

1981-01-01

Adrenocortical hormones have previously been shown to influence cell proliferation in many tissues. In this report, their influence on cell proliferation in the colonic crypt epithelium and in colonic adenocarcinomata is compared. Colonic tumour cell proliferation was found to be retarded following adrenalectomy and this retardation was reversible by administration of hydrocortisone, or by administration of synthetic steroids with predominantly glucocorticoid activity. Tumour cell proliferation in adrenalectomized rats was not promoted by the mineralocorticoid hormone aldosterone. Neither adrenalectomy, nor adrenocortical hormone treatment, significantly influenced colonic crypt cell proliferation.

Proliferation resistance assessment of various methods of spent nuclear fuel storage and disposal

NASA Astrophysics Data System (ADS)

Kollar, Lenka

Many countries are planning to build or already are building new nuclear power plants to match their growing energy needs. Since all nuclear power plants handle nuclear materials that could potentially be converted and used for nuclear weapons, they each present a nuclear proliferation risk. Spent nuclear fuel presents the largest build-up of nuclear material at a power plant. This is a proliferation risk because spent fuel contains plutonium that can be chemically separated and used for a nuclear weapon. The International Atomic Energy Agency (IAEA) safeguards spent fuel in all non-nuclear weapons states that are party to the Non-Proliferation Treaty. Various safeguards methods are in use at nuclear power plants and research is underway to develop safeguards methods for spent fuel in centralized storage or underground storage and disposal. Each method of spent fuel storage presents different proliferation risks due to the nature of the storage method and the safeguards techniques that are utilized. Previous proliferation resistance and proliferation risk assessments have mainly compared nuclear material through the whole fuel cycle and not specifically focused on spent fuel storage. This project evaluates the proliferation resistance of the three main types of spent fuel storage: spent fuel pool, dry cask storage, and geological repository. The proliferation resistance assessment methodology that is used in this project is adopted from previous work and altered to be applicable to spent fuel storage. The assessment methodology utilizes various intrinsic and extrinsic proliferation-resistant attributes for each spent fuel storage type. These attributes are used to calculate a total proliferation resistant (PR) value. The maximum PR value is 1.00 and a greater number means that the facility is more proliferation resistant. Current data for spent fuel storage in the United States and around the world was collected. The PR values obtained from this data are 0.49 for

Excessive Cellular Proliferation Negatively Impacts Reprogramming Efficiency of Human Fibroblasts

PubMed Central

Gupta, Manoj K.; Teo, Adrian Kee Keong; Rao, Tata Nageswara; Bhatt, Shweta; Kleinridders, Andre; Shirakawa, Jun; Takatani, Tomozumi; Hu, Jiang; De Jesus, Dario F.; Windmueller, Rebecca; Wagers, Amy J.

2015-01-01

The impact of somatic cell proliferation rate on induction of pluripotent stem cells remains controversial. Herein, we report that rapid proliferation of human somatic fibroblasts is detrimental to reprogramming efficiency when reprogrammed using a lentiviral vector expressing OCT4, SOX2, KLF4, and cMYC in insulin-rich defined medium. Human fibroblasts grown in this medium showed higher proliferation, enhanced expression of insulin signaling and cell cycle genes, and a switch from glycolytic to oxidative phosphorylation metabolism, but they displayed poor reprogramming efficiency compared with cells grown in normal medium. Thus, in contrast to previous studies, our work reveals an inverse correlation between the proliferation rate of somatic cells and reprogramming efficiency, and also suggests that upregulation of proteins in the growth factor signaling pathway limits the ability to induce pluripotency in human somatic fibroblasts. Significance The efficiency with which human cells can be reprogrammed is of interest to stem cell biology. In this study, human fibroblasts cultured in media containing different concentrations of growth factors such as insulin and insulin-like growth factor-1 exhibited variable abilities to proliferate, with consequences on pluripotency. This occurred in part because of changes in the expression of proteins involved in the growth factor signaling pathway, glycolysis, and oxidative phosphorylation. These findings have implications for efficient reprogramming of human cells. PMID:26253715

tRNA modification profiles of the fast-proliferating cancer cells

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

Dong, Chao; Niu, Leilei; Song, Wei

Despite the recent progress in RNA modification study, a comprehensive modification profile is still lacking for mammalian cells. Using a quantitative HPLC/MS/MS assay, we present here a study where RNA modifications are examined in term of the major RNA species. With paired slow- and fast-proliferating cell lines, distinct RNA modification profiles are first revealed for diverse RNA species. Compared to mRNAs, increased ribose and nucleobase modifications are shown for the highly-structured tRNAs and rRNAs, lending support to their contribution to the formation of high-order structures. This study also reveals a dynamic tRNA modification profile in the fast-proliferating cells. In additionmore » to cultured cells, this unique tRNA profile has been further confirmed with endometrial cancers and their adjacent normal tissues. Taken together, the results indicate that tRNA is a actively regulated RNA species in the fast-proliferating cancer cells, and suggest that they may play a more active role in biological process than expected. -- Highlights: •RNA modifications were first examined in term of the major RNA species. •A dynamic tRNA modifications was characterized for the fast-proliferating cells. •The unique tRNA profile was confirmed with endometrial cancers and their adjacent normal tissues. •tRNA was predicted as an actively regulated RNA species in the fast-proliferating cancer cells.« less

Calcitonin gene-related peptide stimulates proliferation of human endothelial cells.

PubMed Central

Haegerstrand, A; Dalsgaard, C J; Jonzon, B; Larsson, O; Nilsson, J

1990-01-01

The effects of the vasoactive perivascular neuropeptides calcitonin gene-related peptide (CGRP), neurokinin A (NKA), neuropeptide Y (NPY), and vasoactive intestinal polypeptide (VIP) on proliferation of cultured human umbilical vein endothelial cells (HUVECs) were investigated. CGRP was shown to increase both cell number and DNA synthesis, whereas NKA, NPY, and VIP were ineffective. 125I-labeled CGRP was shown to bind to HUVECs and this binding was displaced by addition of unlabeled CGRP, suggesting the existence of specific CGRP receptors. The effect of CGRP on formation of adenosine 3',5'-cyclic monophosphate (cAMP) and inositol phosphates (InsP), two intracellular messengers known to be involved in regulation of cell proliferation, was investigated. CGRP stimulated cAMP formation but was without effect on the formation of InsP. Proliferation, as well as cAMP formation, was also stimulated by cholera toxin. Basic fibroblast growth factor stimulated growth without affecting cAMP or InsP formation, whereas thrombin, which increased InsP formation, did not stimulate proliferation. We thus suggest that CGRP may act as a local factor stimulating proliferation of endothelial cells; that the mechanism of action is associated with cAMP formation; and that this effect of CGRP may be important for formation of new vessels during physiological and pathophysiological events such as ischemia, inflammation, and wound healing. PMID:2159144

Calcitonin gene-related peptide stimulates proliferation of human endothelial cells.

PubMed

Haegerstrand, A; Dalsgaard, C J; Jonzon, B; Larsson, O; Nilsson, J

1990-05-01

The effects of the vasoactive perivascular neuropeptides calcitonin gene-related peptide (CGRP), neurokinin A (NKA), neuropeptide Y (NPY), and vasoactive intestinal polypeptide (VIP) on proliferation of cultured human umbilical vein endothelial cells (HUVECs) were investigated. CGRP was shown to increase both cell number and DNA synthesis, whereas NKA, NPY, and VIP were ineffective. 125I-labeled CGRP was shown to bind to HUVECs and this binding was displaced by addition of unlabeled CGRP, suggesting the existence of specific CGRP receptors. The effect of CGRP on formation of adenosine 3',5'-cyclic monophosphate (cAMP) and inositol phosphates (InsP), two intracellular messengers known to be involved in regulation of cell proliferation, was investigated. CGRP stimulated cAMP formation but was without effect on the formation of InsP. Proliferation, as well as cAMP formation, was also stimulated by cholera toxin. Basic fibroblast growth factor stimulated growth without affecting cAMP or InsP formation, whereas thrombin, which increased InsP formation, did not stimulate proliferation. We thus suggest that CGRP may act as a local factor stimulating proliferation of endothelial cells; that the mechanism of action is associated with cAMP formation; and that this effect of CGRP may be important for formation of new vessels during physiological and pathophysiological events such as ischemia, inflammation, and wound healing.

CCDC106 promotes non-small cell lung cancer cell proliferation.

PubMed

Zhang, Xiupeng; Zheng, Qin; Wang, Chen; Zhou, Haijing; Jiang, Guiyang; Miao, Yuan; Zhang, Yong; Liu, Yang; Li, Qingchang; Qiu, Xueshan; Wang, Enhua

2017-04-18

Coiled-coil domain containing (CCDC) family members enhance tumor cell proliferation, and high CCDC protein levels correlate with unfavorable prognoses. Limited research demonstrated that CCDC106 may promote the degradation of p53/TP53 protein and inhibit its transactivity. The present study demonstrated that CCDC106 expression correlates with advanced TNM stage (P = 0.008), positive regional lymph node metastasis (P < 0.001), and poor overall survival (P < 0.001) in 183 non-small cell lung cancer cases. A549 and H1299 cells were selected as representative of CCDC106-low and CCDC106-high expressing cell lines, respectively. CCDC106 overexpression promoted A549 cell proliferation and xenograft tumor growth in nude mice, while siRNA-mediated CCDC106 knockdown inhibited H1299 cell proliferation. CCDC106 promoted AKT phosphorylation and upregulated the cell cycle-regulating proteins Cyclin A2 and Cyclin B1. Cell proliferation promoted by CCDC106 via Cyclin A2 and Cyclin B1 was rescued by treatment with the AKT inhibitor, LY294002. Our studies revealed that CCDC106 is associated with non-small cell lung cancer progression and unfavorable prognosis. CCDC106 enhanced Cyclin A2 and Cyclin B1 expression and promoted A549 and H1299 cell proliferation, which depended on AKT signaling. These results suggest that CCDC106 may be a novel target for lung cancer treatment.

The effect of nutritional status on myogenic satellite cell proliferation and differentiation.

PubMed

Powell, D J; McFarland, D C; Cowieson, A J; Muir, W I; Velleman, S G

2013-08-01

Early posthatch satellite cell (SC) mitotic activity is a critical component of muscle development and growth. Satellite cells are stem cells that can be induced by nutrition to follow other cellular developmental pathways. The objective of the current study was to determine the effect of restricting protein synthesis on the proliferation and differentiation of SC, using variable concentrations of Met and Cys to modulate protein synthesis. Broiler pectoralis major SC were cultured and treated with 1 of 6 different Met/Cys concentrations: 60/192, 30/96 (control), 7.5/24, 3/9.6, 1/3.2, or 0/0 mg/L. The effect of Met/Cys concentration on SC proliferation and differentiation was measured, and myonuclear accretion was measured by counting the number of nuclei per myotube during differentiation. The 30/96 mg/L Met/Cys treatment resulted in the highest rate of proliferation compared with all other treatments by 72 h of proliferation (P < 0.05). Differentiation was measured with Met/Cys treatments only during proliferation and the cultures receiving normal differentiation medium (R/N), normal proliferation medium and differentiation medium with variable Met/Cys (N/R), or both proliferation and differentiation receiving variable Met/Cys treatments (R/R). Differentiation responded in a dose-dependent manner to Met/Cys concentration under all 3 of these treatment regimens, with a degree of recovery in the R/N regimen cells following reinstatement of the control medium. Reductions in both proliferation and differentiation were more pronounced as Met/Cys concentrations were further reduced, whereas increased differentiation was observed under the increased Met/Cys concentration treatment when applied during differentiation in the N/R and R/R regimens. The number of nuclei per myotube was significantly decreased in the severely Met/Cys restricted treatments (P < 0.05). These data demonstrate the sensitivity of pectoralis major SC to nutritional availability and the importance of

Enhancer of Zeste Homolog 2 Induces Pulmonary Artery Smooth Muscle Cell Proliferation

PubMed Central

Aljubran, Salman A.; Rajanbabu, Venugopal; Bao, Huynh; Mohapatra, Shyam M.; Lockey, Richard; Kolliputi, Narasaiah

2012-01-01

Introduction Pulmonary Arterial Hypertension (PAH) is a progressively devastating disease characterized by excessive proliferation of the Pulmonary Arterial Smooth Muscle Cells (PASMCs). Studies suggest that PAH and cancers share an apoptosis-resistant state featuring excessive cell proliferation. The proliferation of cancer cells is mediated by increased expression of Enhancer of Zeste Homolog 2 (EZH2), a mammalian histone methyltransferase that contributes to the epigenetic silencing of target genes. However, the role of EZH2 in PAH has not been studied. In this study, it is hypothesized that EZH2 could play a role in the proliferation of PASMCs. Methods In the present study, the expression patterns of EZH2 were investigated in normal and hypertensive mouse PASMCs. The effects of EZH2 overexpression on the proliferation of human PASMCs were tested. PASMCs were transfected with EZH2 or GFP using nucleofector system. After transfection, the cells were incubated for 48 hours at 37°C. Proliferation and cell cycle analysis were performed using flow cytometry. Apoptosis of PASMCs was determined using annexin V staining and cell migration was tested by wound healing assay. Results EZH2 protein expression in mouse PASMCs were correlated with an increase in right ventricular systolic pressure and Right Ventricular Hypertrophy (RVH). The overexpression of EZH2 in human PASMCs enhances proliferation, migration, and decrease in the rate of apoptosis when compared to GFP-transfected cells. In the G2/M phase of the EZH2 transfected cells, there was a 3.5 fold increase in proliferation, while there was a significant decrease in the rate of apoptosis of PASMCs, when compared to control. Conclusion These findings suggest that EZH2 plays a role in the migration and proliferation of PASMCs, which is a major hallmark in PAH. It also suggests that EZH2 could play a role in the development of PAH and can serve as a potential target for new therapies for PAH. PMID:22662197

TWEAK induces liver progenitor cell proliferation

PubMed Central

Jakubowski, Aniela; Ambrose, Christine; Parr, Michael; Lincecum, John M.; Wang, Monica Z.; Zheng, Timothy S.; Browning, Beth; Michaelson, Jennifer S.; Baestcher, Manfred; Wang, Bruce; Bissell, D. Montgomery; Burkly, Linda C.

2005-01-01

Progenitor (“oval”) cell expansion accompanies many forms of liver injury, including alcohol toxicity and submassive parenchymal necrosis as well as experimental injury models featuring blocked hepatocyte replication. Oval cells can potentially become either hepatocytes or biliary epithelial cells and may be critical to liver regeneration, particularly when hepatocyte replication is impaired. The regulation of oval cell proliferation is incompletely understood. Herein we present evidence that a TNF family member called TWEAK (TNF-like weak inducer of apoptosis) stimulates oval cell proliferation in mouse liver through its receptor Fn14. TWEAK has no effect on mature hepatocytes and thus appears to be selective for oval cells. Transgenic mice overexpressing TWEAK in hepatocytes exhibit periportal oval cell hyperplasia. A similar phenotype was obtained in adult wild-type mice, but not Fn14-null mice, by administering TWEAK-expressing adenovirus. Oval cell expansion induced by 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) was significantly reduced in Fn14-null mice as well as in adult wild-type mice with a blocking anti-TWEAK mAb. Importantly, TWEAK stimulated the proliferation of an oval cell culture model. Finally, we show increased Fn14 expression in chronic hepatitis C and other human liver diseases relative to its expression in normal liver, which suggests a role for the TWEAK/Fn14 pathway in human liver injury. We conclude that TWEAK has a selective mitogenic effect for liver oval cells that distinguishes it from other previously described growth factors. PMID:16110324

Effect of irradiation on human T-cell proliferation: low dose irradiation stimulates mitogen-induced proliferation and function of the suppressor/cytotoxic T-cell subset

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

Gualde, N.; Goodwin, J.S.

1984-04-01

Unfractionated human T cells exposed to 10-50 rad of X irradiation incorporated less (/sup 3/H)thymidine than nonirradiated T cells when subsequently cultured with PHA or Con A. The cytotoxic/suppressor T-cell subset, isolated as either OKT8(+) or OKT4(-) cells, demonstrated significantly enhanced (/sup 3/H)thymidine incorporation in PHA- or Con A-stimulated cultures after exposure to 10-50 rad, compared to unirradiated cells, while the proliferation of the OKT4(+) helper/inducer subset was inhibited by low dose irradiation. It has been previously reported that approximately 30% of the cytotoxic/suppressor subset also stains with OKM1. When the cytotoxic/suppressor subset was further subdivided into OKT4(-), OKM1(+), andmore » OKT4(-), OKM1(-) cells, proliferation of the OKT4(-), OKM1(+) population was inhibited by exposure to 25 rad while proliferation of the OKT4(-), OKM1(-) population was stimulated. The increase in proliferation of the cytotoxic/suppressor T-cell subset after low dose irradiation is paralleled by an increase in suppressor activity of these cells. T cells exposed to 25 rad and then cultured with Con A for 48 hr caused greater inhibition of IgG production when added to fresh autologous lymphocytes stimulated by pokeweed mitogen than did unirradiated cells. Thus, low dose irradiation enhances both the proliferation and function of the human suppressor T-cell subset.« less

Tetraspanin CD9 modulates human lymphoma cellular proliferation via histone deacetylase activity

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

Herr, Michael J.; Department of Medicine, The University of Tennessee Health Science Center, Memphis, TN 38163; Department of Molecular Sciences, The University of Tennessee Health Science Center, Memphis, TN 38163

2014-05-16

Highlights: • CD9 is differentially expressed in human Burkitt’s lymphoma cells. • We found that CD9 expression promotes these cells proliferation. • CD9 expression also increases HDAC activity. • HDAC inhibition decreased both cell proliferation and importantly CD9 expression. • CD9 may dictate HDAC efficacy and play a role in HDAC regulation. - Abstract: Non-Hodgkin Lymphoma (NHL) is a type of hematological malignancy that affects two percent of the overall population in the United States. Tetraspanin CD9 is a cell surface protein that has been thoroughly demonstrated to be a molecular facilitator of cellular phenotype. CD9 expression varies in twomore » human lymphoma cell lines, Raji and BJAB. In this report, we investigated the functional relationship between CD9 and cell proliferation regulated by histone deacetylase (HDAC) activity in these two cell lines. Introduction of CD9 expression in Raji cells resulted in significantly increased cell proliferation and HDAC activity compared to Mock transfected Raji cells. The increase in CD9–Raji cell proliferation was significantly inhibited by HDAC inhibitor (HDACi) treatment. Pretreatment of BJAB cells with HDAC inhibitors resulted in a significant decrease in endogenous CD9 mRNA and cell surface expression. BJAB cells also displayed decreased cell proliferation after HDACi treatment. These results suggest a significant relationship between CD9 expression and cell proliferation in human lymphoma cells that may be modulated by HDAC activity.« less

Heme-induced Trypanosoma cruzi proliferation is mediated by CaM kinase II

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

Souza, C.F.; Carneiro, A.B.; Silveira, A.B.

2009-12-18

Trypanosoma cruzi, the etiologic agent of Chagas disease, is transmitted through triatomine vectors during their blood-meal on vertebrate hosts. These hematophagous insects usually ingest approximately 10 mM of heme bound to hemoglobin in a single meal. Blood forms of the parasite are transformed into epimastigotes in the crop which initiates a few hours after parasite ingestion. In a previous work, we investigated the role of heme in parasite cell proliferation and showed that the addition of heme significantly increased parasite proliferation in a dose-dependent manner . To investigate whether the heme effect is mediated by protein kinase signalling pathways, parasitemore » proliferation was evaluated in the presence of several protein kinase (PK) inhibitors. We found that only KN-93, a classical inhibitor of calcium-calmodulin-dependent kinases (CaMKs), blocked heme-induced cell proliferation. KN-92, an inactive analogue of KN-93, was not able to block this effect. A T. cruzi CaMKII homologue is most likely the main enzyme involved in this process since parasite proliferation was also blocked when Myr-AIP, an inhibitory peptide for mammalian CaMKII, was included in the cell proliferation assay. Moreover, CaMK activity increased in parasite cells with the addition of heme as shown by immunological and biochemical assays. In conclusion, the present results are the first strong indications that CaMKII is involved in the heme-induced cell signalling pathway that mediates parasite proliferation.« less

Denuclearization for a Just World: The Failure of Non Proliferation.

ERIC Educational Resources Information Center

Institute for World Order, New York, NY.

The document discusses the non proliferation policies of nuclear power nations. It specifically focuses on the credibility gap which exists between the actual statements of peaceful intentions made by these nations which express the need for non proliferation of nuclear weapons and their actual conduct with regards to nuclear-related issues in…

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

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.

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

Mitochondrial motility and vascular smooth muscle proliferation.

PubMed

Chalmers, Susan; Saunter, Christopher; Wilson, Calum; Coats, Paul; Girkin, John M; McCarron, John G

2012-12-01

Mitochondria are widely described as being highly dynamic and adaptable organelles, and their movement is thought to be vital for cell function. Yet, in various native cells, including those of heart and smooth muscle, mitochondria are stationary and rigidly structured. The significance of the differences in mitochondrial behavior to the physiological function of cells is unclear and was studied in single myocytes and intact resistance-sized cerebral arteries. We hypothesized that mitochondrial dynamics is controlled by the proliferative status of the cells. High-speed fluorescence imaging of mitochondria in live vascular smooth muscle cells shows that the organelle undergoes significant reorganization as cells become proliferative. In nonproliferative cells, mitochondria are individual (≈ 2 μm by 0.5 μm), stationary, randomly dispersed, fixed structures. However, on entering the proliferative state, mitochondria take on a more diverse architecture and become small spheres, short rod-shaped structures, long filamentous entities, and networks. When cells proliferate, mitochondria also continuously move and change shape. In the intact pressurized resistance artery, mitochondria are largely immobile structures, except in a small number of cells in which motility occurred. When proliferation of smooth muscle was encouraged in the intact resistance artery, in organ culture, the majority of mitochondria became motile and the majority of smooth muscle cells contained moving mitochondria. Significantly, restriction of mitochondrial motility using the fission blocker mitochondrial division inhibitor prevented vascular smooth muscle proliferation in both single cells and the intact resistance artery. These results show that mitochondria are adaptable and exist in intact tissue as both stationary and highly dynamic entities. This mitochondrial plasticity is an essential mechanism for the development of smooth muscle proliferation and therefore presents a novel therapeutic

Extracapillary proliferation in IgA nephropathy; recent findings and new ideas.

PubMed

Nasri, Hamid; Mubarak, Muhammed

2015-01-01

IgA nephropathy (IgAN) is an autoimmune disorder and is the most common form of primary glomerulonephritis (GN) worldwide. Directory of Open Access Journals (DOAJ), Google Scholar, PubMed (NLM), LISTA (EBSCO) and Web of Science have been searched. It is a slowly progressing disorder that leads to end-stage renal disease (ESRD) in up to 50% of the patients within 25 years of the onset of the disease. IgAN is defined by predominant IgA deposition in the mesangial area on immunofluorescence (IF) microscopy. Its histology varies from mild focal segmental proliferation of mesangial cells to severe diffuse global proliferation with extracapillary proliferation (crescent formation). The Oxford classification, designed in 2009, is a new classification for the evaluation of morphologic lesions of IgAN. This classification, containing four pathology variables, was found to have prognostic implications. The variables included are mesangial hypercellularity (M), endocapillary proliferation (E), segmental glomerulosclerosis (S) and the proportion of interstitial fibrosis and tubular atrophy (T). However, crescents were not included in the Oxford classification. In this mini-review, we describe the recent publications about the significance of extracapillary proliferation in IgAN and we conclude that, there is much controversy about the role of extracapillary proliferation as a significant prognostic factor in IgAN. Hence, it is important to re-consider crescents in IgAN patients. Therefore, we suggest further investigations on this aspect of IgAN disease.

Extracapillary proliferation in IgA nephropathy; recent findings and new ideas

PubMed Central

Nasri, Hamid; Mubarak, Muhammed

2015-01-01

Context: IgA nephropathy (IgAN) is an autoimmune disorder and is the most common form of primary glomerulonephritis (GN) worldwide. Evidence Acquisitions: Directory of Open Access Journals (DOAJ), Google Scholar, PubMed (NLM), LISTA (EBSCO) and Web of Science have been searched. Results: It is a slowly progressing disorder that leads to end-stage renal disease (ESRD) in up to 50% of the patients within 25 years of the onset of the disease. IgAN is defined by predominant IgA deposition in the mesangial area on immunofluorescence (IF) microscopy. Its histology varies from mild focal segmental proliferation of mesangial cells to severe diffuse global proliferation with extracapillary proliferation (crescent formation). The Oxford classification, designed in 2009, is a new classification for the evaluation of morphologic lesions of IgAN. This classification, containing four pathology variables, was found to have prognostic implications. The variables included are mesangial hypercellularity (M), endocapillary proliferation (E), segmental glomerulosclerosis (S) and the proportion of interstitial fibrosis and tubular atrophy (T). However, crescents were not included in the Oxford classification. Conclusions: In this mini-review, we describe the recent publications about the significance of extracapillary proliferation in IgAN and we conclude that, there is much controversy about the role of extracapillary proliferation as a significant prognostic factor in IgAN. Hence, it is important to re-consider crescents in IgAN patients. Therefore, we suggest further investigations on this aspect of IgAN disease. PMID:25657978

Platelet-released growth factors inhibit proliferation of primary keratinocytes in vitro.

PubMed

Bayer, Andreas; Tohidnezhad, Mersedeh; Berndt, Rouven; Lippross, Sebastian; Behrendt, Peter; Klüter, Tim; Pufe, Thomas; Jahr, Holger; Cremer, Jochen; Rademacher, Franziska; Simanski, Maren; Gläser, Regine; Harder, Jürgen

2018-01-01

Autologous thrombocyte concentrate lysates as platelet-released growth factors (PRGF) or Vivostat Platelet Rich Fibrin (PRF ® ) represent important tools in modern wound therapy, especially in the treatment of chronic, hard-to-heal or infected wounds. Nevertheless, underlying cellular and molecular mechanisms of the beneficial clinical effects of a local wound therapy with autologous thrombocyte concentrate lysates are poorly understood. Recently, we have demonstrated that PRGF induces antimicrobial peptides in primary keratinocytes and accelerates keratinocytes' differentiation. In the present study we analyzed the influence of PRGF on primary human keratinocytes' proliferation. Using the molecular proliferation marker Ki-67 we observed a concentration- and time dependent inhibition of Ki-67 gene expression in PRGF treated primary keratinocytes. These effects were independent from the EGFR- and the IL-6-R pathway. Inhibition of primary keratinocytes' proliferation by PRGF treatment was confirmed in colorimetric cell proliferation assays. Together, these data indicate that the clinically observed positive effects of autologous thrombocytes concentrates in the treatment of chronic, hard-to-heal wounds are not based on an increased keratinocytes proliferation. Copyright © 2017 Elsevier GmbH. All rights reserved.

Activation of peroxisome proliferator-activated receptor beta/delta induces lung cancer growth via peroxisome proliferator-activated receptor coactivator gamma-1alpha.

PubMed

Han, Shouwei; Ritzenthaler, Jeffrey D; Sun, Xiaojuan; Zheng, Ying; Roman, Jesse

2009-03-01

We previously demonstrated that a selective agonist of peroxisome proliferator-activated receptor beta/delta (PPARbeta/delta), GW501516, stimulated human non-small cell lung carcinoma (NSCLC) growth, partly through inhibition of phosphatase and tensin homolog deleted on chromosome 10 expression. Here, we show that GW501516 also decreases the phosphorylation of AMP-activated protein kinase alpha (AMPKalpha), a major regulator of energy metabolism. This was mediated through specific activation of PPARbeta/delta, as a PPARbeta/delta small interfering RNA inhibited the effect. However, AMPKalpha did not mediate the growth-promoting effects of GW501516, as silencing of AMPKalpha did not inhibit GW501516-induced cell proliferation. Instead, we found that GW501516 stimulated peroxisome proliferator-activated receptor coactivator gamma (PGC)-1alpha, which activated the phosphatidylinositol 3 kinase (PI3-K)/Akt mitogenic pathway. An inhibitor of PI3-K, LY294002, had no effect on PGC-1alpha, consistent with PGC-1alpha being upstream of PI3-K/Akt. Of note, an activator of AMPKalpha, 5-amino-4-imidazole carboxamide riboside, inhibited the growth-promoting effects of GW501516, suggesting that although AMPKalpha is not responsible for the mitogenic effects of GW501516, its activation can oppose these events. This study unveils a novel mechanism by which GW501516 and activation of PPARbeta/delta stimulate human lung carcinoma cell proliferation, and suggests that activation of AMPKalpha may oppose this effect.

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

Osteosarcoma cells induce endothelial cell proliferation during neo-angiogenesis.

PubMed

de Nigris, Filomena; Mancini, Francesco Paolo; Schiano, Concetta; Infante, Teresa; Zullo, Alberto; Minucci, Pellegrino Biagio; Al-Omran, Mohammed; Giordano, Antonio; Napoli, Claudio

2013-04-01

Understanding the mechanisms inducing endothelial cell (EC) proliferation following tumor microenvironment stimuli may be important for the development of antiangiogenic therapies. Here, we show that cyclin-dependent kinase 2 and 5 (Cdk2, Cdk5) are important mediators of neoangiogenesis in in vitro and in vivo systems. Furthermore, we demonstrate that a specific Yin Yang 1 (YY1) protein-dependent signal from osteosarcoma (SaOS) cells determines proliferation of human aortic endothelial cells (HAECs). Following tumor cell stimuli, HAECs overexpress Cdk2 and Cdk5, display increased Cdk2 activity, undergo enhanced proliferation, and form capillary-like structures. Moreover, Roscovitine, an inhibitor of Cdks, blunted overexpression of Cdk2 and Cdk5 and Cdk2 activity induced by the YY1-dependent signal secreted by SaOS cells. Furthermore, Roscovitine decreased HAEC proliferation and angiogenesis (the latter by 70% in in vitro and 50% in in vivo systems; P < 0.01 vs. control). Finally, the finding that Roscovitine triggers apoptosis in SaOS cells as well as in HAECs by activating caspase-3/7 indicates multiple mechanisms for the potential antitumoral effect of Roscovitine. Present work suggests that Cdk2 and Cdk5 might be pharmacologically accessible targets for both antiangiogenic and antitumor therapy. Copyright © 2012 Wiley Periodicals, Inc.

Role of CYP2B in Phenobarbital-Induced Hepatocyte Proliferation in Mice.

PubMed

Li, Lei; Bao, Xiaochen; Zhang, Qing-Yu; Negishi, Masahiko; Ding, Xinxin

2017-08-01

Phenobarbital (PB) promotes liver tumorigenesis in rodents, in part through activation of the constitutive androstane receptor (CAR) and the consequent changes in hepatic gene expression and increases in hepatocyte proliferation. A typical effect of CAR activation by PB is a marked induction of Cyp2b10 expression in the liver; the latter has been suspected to be vital for PB-induced hepatocellular proliferation. This hypothesis was tested here by using a Cyp2a(4/5)bgs -null (null) mouse model in which all Cyp2b genes are deleted. Adult male and female wild-type (WT) and null mice were treated intraperitoneally with PB at 50 mg/kg once daily for 5 successive days and tested on day 6. The liver-to-body weight ratio, an indicator of liver hypertrophy, was increased by 47% in male WT mice, but by only 22% in male Cyp2a(4/5)bgs -null mice, by the PB treatment. The fractions of bromodeoxyuridine-positive hepatocyte nuclei, assessed as a measure of the rate of hepatocyte proliferation, were also significantly lower in PB-treated male null mice compared with PB-treated male WT mice. However, whereas few proliferating hepatocytes were detected in saline-treated mice, many proliferating hepatocytes were still detected in PB-treated male null mice. In contrast, female WT mice were much less sensitive than male WT mice to PB-induced hepatocyte proliferation, and PB-treated female WT and PB-treated female null mice did not show significant difference in rates of hepatocyte proliferation. These results indicate that CYP2B induction plays a significant, but partial, role in PB-induced hepatocyte proliferation in male mice. U.S. Government work not protected by U.S. copyright.

Enhanced Keratinocyte Proliferation and Migration in Co-culture with Fibroblasts

PubMed Central

Wang, Zhenxiang; Wang, Ying; Farhangfar, Farhang; Zimmer, Monica; Zhang, Yongxin

2012-01-01

Wound healing is primarily controlled by the proliferation and migration of keratinocytes and fibroblasts as well as the complex interactions between these two cell types. To investigate the interactions between keratinocytes and fibroblasts and the effects of direct cell-to-cell contact on the proliferation and migration of keratinocytes, keratinocytes and fibroblasts were stained with different fluorescence dyes and co-cultured with or without transwells. During the early stage (first 5 days) of the culture, the keratinocytes in contact with fibroblasts proliferated significantly faster than those not in contact with fibroblasts, but in the late stage (11th to 15th day), keratinocyte growth slowed down in all cultures unless EGF was added. In addition, keratinocyte migration was enhanced in co-cultures with fibroblasts in direct contact, but not in the transwells. Furthermore, the effects of the fibroblasts on keratinocyte migration and growth at early culture stage correlated with heparin-binding EGF-like growth factor (HB-EGF), IL-1α and TGF-β1 levels in the cultures where the cells were grown in direct contact. These effects were inhibited by anti-HB-EGF, anti-IL-1α and anti-TGF-β1 antibodies and anti-HB-EGF showed the greatest inhibition. Co-culture of keratinocytes and IL-1α and TGF-β1 siRNA-transfected fibroblasts exhibited a significant reduction in HB-EGF production and keratinocyte proliferation. These results suggest that contact with fibroblasts stimulates the migration and proliferation of keratinocytes during wound healing, and that HB-EGF plays a central role in this process and can be up-regulated by IL-1α and TGF-β1, which also regulate keratinocyte proliferation differently during the early and late stage. PMID:22911722

Discoidin domain receptor 2 (DDR2) regulates proliferation of endochondral cells in mice

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

Kawai, Ikuma; Hisaki, Tomoka; Sugiura, Koji

2012-10-26

Highlights: Black-Right-Pointing-Pointer Discoidin domain receptor 2 (DDR2) is a receptor tyrosine kinase. Black-Right-Pointing-Pointer DDR2 regulates cell proliferation, cell adhesion, migration, and extracellular matrix remodeling. Black-Right-Pointing-Pointer We produced in vitro and in vivo model to better understand the role of DDR2. Black-Right-Pointing-Pointer DDR2 might play an inhibitory role in the proliferation of chondrocyte. -- Abstract: Discoidin domain receptor 2 (DDR2) is a receptor tyrosine kinase that is activated by fibrillar collagens. DDR2 regulates cell proliferation, cell adhesion, migration, and extracellular matrix remodeling. The decrement of endogenous DDR2 represses osteoblastic marker gene expression and osteogenic differentiation in murine preosteoblastic cells, but themore » functions of DDR2 in chondrogenic cellular proliferation remain unclear. To better understand the role of DDR2 signaling in cellular proliferation in endochondral ossification, we inhibited Ddr2 expression via the inhibitory effect of miRNA on Ddr2 mRNA (miDdr2) and analyzed the cellular proliferation and differentiation in the prechondrocyte ATDC5 cell lines. To investigate DDR2's molecular role in endochondral cellular proliferation in vivo, we also produced transgenic mice in which the expression of truncated, kinase dead (KD) DDR2 protein is induced, and evaluated the DDR2 function in cellular proliferation in chondrocytes. Although the miDdr2-transfected ATDC5 cell lines retained normal differentiation ability, DDR2 reduction finally promoted cellular proliferation in proportion to the decreasing ratio of Ddr2 expression, and it also promoted earlier differentiation to cartilage cells by insulin induction. The layer of hypertrophic chondrocytes in KD Ddr2 transgenic mice was not significantly thicker than that of normal littermates, but the layer of proliferative chondrocytes in KD-Ddr2 transgenic mice was significantly thicker than that of normal

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

Folic acid and pteroylpolyglutamate contents of archaebacteria.

PubMed Central

Worrell, V E; Nagle, D P

1988-01-01

Cell extracts of methanogens and the thermoacidophile Sulfolobus solfataricus contained little or no folic acid (pteroylglutamate) or pteroylpolyglutamate activity (less than 0.1 nmol/g [dry weight]). However, the halophile Halobacterium salinarum contained pteroylmono- or pteroyldiglutamates, and Halobacterium volcanii and Halobacterium halobium contained pteroyltriglutamates at levels equivalent to those in eubacteria (greater than 1 nmol/g [dry weight]). PMID:3137217

Homeobox A7 stimulates breast cancer cell proliferation by up-regulating estrogen receptor-alpha

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

Zhang, Yu; Department of Obstetrics and Gynaecology, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia V5Z 4H4; Cheng, Jung-Chien

2013-11-01

Highlights: •HOXA7 regulates MCF7 cell proliferation. •HOXA7 up-regulates ERα expression. •HOXA7 mediates estrogen-induced MCF7 cell proliferation. -- Abstract: Breast cancer is the most common hormone-dependent malignancy in women. Homeobox (HOX) transcription factors regulate many cellular functions, including cell migration, proliferation and differentiation. The aberrant expression of HOX genes has been reported to be associated with human reproductive cancers. Estradiol (E2) and its nuclear receptors, estrogen receptor (ER)-alpha and ER-beta, are known to play critical roles in the regulation of breast cancer cell growth. However, an understanding of the potential relationship between HOXA7 and ER in breast cancer cells is limited.more » In this study, our results demonstrate that knockdown of HOXA7 in MCF7 cells significantly decreased cell proliferation and ERα expression. In addition, HOXA7 knockdown attenuated E2-induced cell proliferation as well as progesterone receptor (PR) expression. The stimulatory effects of E2 on cell proliferation and PR expression were abolished by co-treatment with ICI 182780, a selective ERα antagonist. In contrast, overexpression of HOXA7 significantly stimulated cell proliferation and ERα expression. Moreover, E2-induced cell proliferation, as well as PR expression, was enhanced by the overexpression of HOXA7. Neither knockdown nor overexpression of HOXA7 affected the ER-beta levels. Our results demonstrate a novel mechanistic role for HOXA7 in modulating breast cancer cell proliferation via regulation of ERα expression. This finding contributes to our understanding of the role HOXA7 plays in regulating the proliferation of ER-positive cancer cells.« less

Epidermal growth factor receptor is required for estradiol-stimulated bovine satellite cell proliferation.

PubMed

Reiter, B C; Kamanga-Sollo, E; Pampusch, M S; White, M E; Dayton, W R

2014-07-01

The objective of this study was to assess the role of the epidermal growth factor receptor (EGFR) in estradiol-17β (E2)-stimulated proliferation of cultured bovine satellite cells (BSCs). Treatment of BSC cultures with AG1478 (a specific inhibitor of EGFR tyrosine kinase activity) suppresses E2-stimulated BSC proliferation (P < 0.05). In addition, E2-stimulated proliferation is completely suppressed (P < 0.05) in BSCs in which EGFR expression is silenced by treatment with EGFR small interfering RNA (siRNA). These results indicate that EGFR is required for E2 to stimulate proliferation in BSC cultures. Both AG1478 treatment and EGFR silencing also suppress proliferation stimulated by LR3-IGF-1 (an IGF1 analogue that binds normally to the insulin-like growth factor receptor (IGFR)-1 but has little or no affinity for IGF binding proteins) in cultured BSCs (P < 0.05). Even though EGFR siRNA treatment has no effect on IGFR-1β mRNA expression in cultured BSCs, IGFR-1β protein level is substantially reduced in BSCs treated with EGFR siRNA. These data suggest that EGFR silencing results in post-transcriptional modifications that result in decreased IGFR-1β protein levels. Although it is clear that functional EGFR is necessary for E2-stimulated proliferation of BSCs, the role of EGFR is not clear. Transactivation of EGFR may directly stimulate proliferation, or EGFR may function to maintain the level of IGFR-1β which is necessary for E2-stimulated proliferation. It also is possible that the role of EGFR in E2-stimulated BSC proliferation may involve both of these mechanisms. Copyright © 2014 Elsevier Inc. All rights reserved.

78 FR 33995 - Nuclear Proliferation Assessment in Licensing Process for Enrichment or Reprocessing Facilities

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-06

... designed to minimize proliferation risks world-wide, including the Nuclear Non- Proliferation Treaty, the U... and licensees ensure that they comply with requirements designed to minimize proliferation risks... NRC's regulations on physical security, information security, material control and accounting, cyber...

The impact of 27-hydroxycholesterol on endometrial cancer proliferation.

PubMed

Gibson, Douglas A; Collins, Frances; Cousins, Fiona L; Esnal Zufiaurre, Arantza; Saunders, Philippa T K

2018-04-01

Endometrial cancer (EC) is the most common gynaecological malignancy. Obesity is a major risk factor for EC and is associated with elevated cholesterol. 27-hydroxycholesterol (27HC) is a cholesterol metabolite that functions as an endogenous agonist for Liver X receptor (LXR) and a selective oestrogen receptor modulator (SERM). Exposure to oestrogenic ligands increases risk of developing EC; however, the impact of 27HC on EC is unknown. Samples of stage 1 EC ( n  = 126) were collected from postmenopausal women undergoing hysterectomy. Expression of LXRs ( NR1H3 , LXRα; NR1H2 , LXRβ) and enzymes required for the synthesis ( CYP27A1 ) or breakdown ( CYP7B1 ) of 27HC were detected in all grades of EC. Cell lines originating from well-, moderate- and poorly-differentiated ECs (Ishikawa, RL95, MFE 280 respectively) were used to assess the impact of 27HC or the LXR agonist GW3965 on proliferation or expression of a luciferase reporter gene under the control of LXR- or ER-dependent promoters (LXRE, ERE). Incubation with 27HC or GW3965 increased transcription via LXRE in Ishikawa, RL95 and MFE 280 cells ( P  < 0.01). 27HC selectively activated ER-dependent transcription ( P  < 0.001) in Ishikawa cells and promoted proliferation of both Ishikawa and RL95 cells ( P  < 0.001). In MFE 280 cells, 27HC did not alter proliferation but selective targeting of LXR with GW3965 significantly reduced cell proliferation ( P  < 0.0001). These novel results suggest that 27HC can contribute to risk of EC by promoting proliferation of endometrial cancer epithelial cells and highlight LXR as a potential therapeutic target in the treatment of advanced disease. © 2018 The authors.

Keyhole limpet hemocyanin augmented the killing activity, cytokine production and proliferation of NK cells, and inhibited the proliferation of Meth A sarcoma cells in vitro.

PubMed

Sarker, Md Moklesur Rahman; Zhong, Ming

2014-01-01

Keyhole limpet hemocyanin (KLH) is a popular tumor vaccine carrier protein and an immunostimulant. The present study aimed to investigate the immunoregulatory activity of KLH on cytotoxicity, cytokines production, and proliferation of natural killer (NK) cells. Moreover, antiproliferative activity of KLH on Meth A sarcoma cells was studied. Cytotoxicity was determined with killing ability of NK cells against yeast artificial chromosome (YAC)-1 cells. Interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α) productions by NK cells were measured by enzyme-linked immunosorbent assay (ELISA). Proliferations of NK and Meth A cells were determined by [(3)H]thymidine incorporated proliferation and 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) methods, respectively. KLH at 6.25, 12.5, and 25 μg/well augmented cytotoxicity of NK cells against YAC-1 cells by 2.5, three, and five-times, respectively. KLH at 25 μg/well enhanced IFN-γ and TNF-α productions by 17- and 23-folds, respectively. The proliferation of NK cells was three times stimulated by KLH. The proliferation of Meth A cells was markedly inhibited by all the doses; the highest (4-folds higher) inhibition was observed at a dose of KLH (25 μg/well). The study demonstrated the anticancer activity of KLH acting through the induction of NK cells and inhibition of cancer cells. KLH, therefore, may be a good candidate for an anticancer agent alone or in combination with other chemotherapeutic agents.

Cell proliferation in dimethylhydrazine-induced colonic adenocarcinomata following cytotoxic drug treatment.

PubMed

Tutton, P J; Barkla, D H

1978-08-25

A stathmokinetic technique was used to study cell proliferation in dimethylhydrazine-induced adenocarcinomata of rat colon following treatment with cytotoxic drugs. The rate of cell division was significantly increased three days after treatment with 5,7-dihydroxytryptamine and seven days after treatment with 5-fluorouracil. Acceleration of tumour cell proliferation following 5,7-dihydroxytryptamine treatment was inhibited by treating animals with the antiseritoninergic drug Xylamidine Tosylate. Acceleration of tumour cell proliferation following 5-fluorouracil treatment was inhibited by treating animals either with the antiseritoninergic drug BW501 or with the histamine H2-receptor blocking drug Cimetidine.

Bisdemethoxycurcumin inhibits PDGF-induced vascular smooth muscle cell motility and proliferation

PubMed Central

Hua, Yinan; Dolence, Julia; Ramanan, Shalini; Ren, Jun; Nair, Sreejayan

2013-01-01

Scope A key event in the development of plaque in the arteries is the migration and proliferation of smooth muscle cells (SMCs) from the media to the intima of the blood vessel. This study was conducted to evaluate the effects of bisdemethoxycurcumin, a naturally occurring structural analog of curcumin, on PDGF-stimulated migration and proliferation of SMCs. Methods and results Demethoxycurcumin were synthesized by condensing vanillin and 4-hydroxybenzaldehyde. SMCs isolated from adult rat aorta were stimulated with PDGF in the presence or absence of curcumin or bisdemethoxycurcumin following which cell migration and proliferation were assessed by monolayer wound healing assay and [3H]-thymidine incorporation respectively. PDGF-induced phosphorylation of PDGF-receptor-β and its downstream effector Akt were assessed by Western blotting. Intracellular reactive oxygen species (ROS) was assessed using the fluorescent dye DCFDA. Bisdemethoxycurcumin elicited a concentration-dependent inhibition of PDGF-stimulated phosphorylation of PDGFR-β, Akt and Erk as well as the PDGF-stimulated SMC migration and proliferation. Bisdemethoxycurcumin was more potent than curcumin in inhibiting migration and proliferation and suppressing PDGF-signaling in SMCs. Both compounds were equipotent in inhibiting PDGF-stimulated intracellular ROS-generation. Conclusion Bisdemethoxycurcumin may be of potential use in the prevention or treatment of vascular disease. PMID:23554078

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

Substrate effect modulates adhesion and proliferation of fibroblast on graphene layer.

PubMed

Lin, Feng; Du, Feng; Huang, Jianyong; Chau, Alicia; Zhou, Yongsheng; Duan, Huiling; Wang, Jianxiang; Xiong, Chunyang

2016-10-01

Graphene is an emerging candidate for biomedical applications, including biosensor, drug delivery and scaffold biomaterials. Cellular functions and behaviors on different graphene-coated substrates, however, still remain elusive to a great extent. This paper explored the functional responses of cells such as adhesion and proliferation, to different kinds of substrates including coverslips, silicone, polydimethylsiloxane (PDMS) with different curing ratios, PDMS treated with oxygen plasma, and their counterparts coated with single layer graphene (SLG). Specifically, adherent cell number, spreading area and cytoskeleton configuration were exploited to characterize cell-substrate adhesion ability, while MTT assay was employed to test the proliferation capability of fibroblasts. Experimental outcome demonstrated graphene coating had excellent cytocompatibility, which could lead to an increase in early adhesion, spreading, proliferation, and remodeling of cytoskeletons of fibroblast cells. Notably, it was found that the underlying substrate effect, e.g., stiffness of substrate materials, could essentially regulate the adhesion and proliferation of cells cultured on graphene. The stiffer the substrates were, the stronger the abilities of adhesion and proliferation of fibroblasts were. This study not only deepens our understanding of substrate-modulated interfacial interactions between live cells and graphene, but also provides a valuable guidance for the design and application of graphene-based biomaterials in biomedical engineering. Copyright © 2016 Elsevier B.V. All rights reserved.

Differential activation of natriuretic peptide receptors modulates cardiomyocyte proliferation during development

PubMed Central

Becker, Jason R.; Chatterjee, Sneha; Robinson, Tamara Y.; Bennett, Jeffrey S.; Panáková, Daniela; Galindo, Cristi L.; Zhong, Lin; Shin, Jordan T.; Coy, Shannon M.; Kelly, Amy E.; Roden, Dan M.; Lim, Chee Chew; MacRae, Calum A.

2014-01-01

Organ development is a highly regulated process involving the coordinated proliferation and differentiation of diverse cellular populations. The pathways regulating cell proliferation and their effects on organ growth are complex and for many organs incompletely understood. In all vertebrate species, the cardiac natriuretic peptides (ANP and BNP) are produced by cardiomyocytes in the developing heart. However, their role during cardiogenesis is not defined. Using the embryonic zebrafish and neonatal mammalian cardiomyocytes we explored the natriuretic peptide signaling network during myocardial development. We observed that the cardiac natriuretic peptides ANP and BNP and the guanylate cyclase-linked natriuretic peptide receptors Npr1 and Npr2 are functionally redundant during early cardiovascular development. In addition, we demonstrate that low levels of the natriuretic peptides preferentially activate Npr3, a receptor with Gi activator sequences, and increase cardiomyocyte proliferation through inhibition of adenylate cyclase. Conversely, high concentrations of natriuretic peptides reduce cardiomyocyte proliferation through activation of the particulate guanylate cyclase-linked natriuretic peptide receptors Npr1 and Npr2, and activation of protein kinase G. These data link the cardiac natriuretic peptides in a complex hierarchy modulating cardiomyocyte numbers during development through opposing effects on cardiomyocyte proliferation mediated through distinct cyclic nucleotide signaling pathways. PMID:24353062

Moclobemide up-regulates proliferation of hippocampal progenitor cells in chronically stressed mice.

PubMed

Li, Yun-feng; Zhang, You-zhi; Liu, Yan-qin; Wang, Heng-lin; Yuan, Li; Luo, Zhi-pu

2004-11-01

To explore the action mechanism of antidepressants. The PC12 cell proliferation was detected by flow cytometry. The proliferation of hippocampal progenitor cells and level of brain-derived neurotrophic factor (BDNF) were measured by immunohistochemistry. Treatment with N-methylaspartate (NMDA) 600 micromol/L for 3 d significantly decreased the percentage of S-phase in PC12 cells, while in the presence of classical antidepressant, moclobemide (MOC) 2 and 10 micromol/L, the percentage in S-phase increased. Furthermore, the proliferation of progenitor cells in hippocampal dentate gyrus (subgranular zone), as well as the level of BDNF in hippocampus significantly decreased in chronically stressed mice, while chronic administration with MOC 40 mg/kg (ip) up-regulated the progenitor cell proliferation and BDNF level in the same time course. Up-regulation of the proliferation of hippocampal progenitor cells is one of the action mechanisms for MOC, which may be closely related to the elevation of BDNF level at the same time. These results also extend evidence for our hypothesis that up-regulation of the hippocampal neurogenesis is one of the common mechanisms for antidepressants.

C/EBPβ regulates homeostatic and oncogenic gastric cell proliferation.

PubMed

Regalo, Goncalo; Förster, Susann; Resende, Carlos; Bauer, Bianca; Fleige, Barbara; Kemmner, Wolfgang; Schlag, Peter M; Meyer, Thomas F; Machado, José C; Leutz, Achim

2016-12-01

Cancer of the stomach is among the leading causes of death from cancer worldwide. The transcription factor C/EBPβ is frequently overexpressed in gastric cancer and associated with the suppression of the differentiation marker TFF1. We show that the murine C/EBPβ knockout stomach displays unbalanced homeostasis and reduced cell proliferation and that tumorigenesis of human gastric cancer xenograft is inhibited by knockdown of C/EBPβ. Cross-species comparison of gene expression profiles between C/EBPβ-deficient murine stomach and human gastric cancer revealed a subset of tumors with a C/EBPβ signature. Within this signature, the RUNX1t1 tumor suppressor transcript was down-regulated in 38 % of gastric tumor samples. The RUNX1t1 promoter was frequently hypermethylated and ectopic expression of RUNX1t1 in gastric cancer cells inhibited proliferation and enhanced TFF1 expression. These data suggest that the tumor suppressor activity of both RUNX1t1 and TFF1 are mechanistically connected to C/EBPβ and that cross-regulation between C/EBPβ-RUNX1t1-TFF1 plays an important role in gastric carcinogenesis. C/EBPβ controls proliferation and differentiation balance in the stomach. Homeostatic differentiation/proliferation balance is altered in gastric cancer. RUNX1t1 is a C/EBPβ-associated tumor suppressor. RUNX1t1 negatively regulates C/EBPβ pro-oncogenic functions.

Persistence of γ-H2AX and 53BP1 foci in proliferating and non-proliferating human mammary epithelial cells after exposure to γ-rays or iron ions.

PubMed

Groesser, Torsten; Chang, Hang; Fontenay, Gerald; Chen, James; Costes, Sylvain V; Helen Barcellos-Hoff, Mary; Parvin, Bahram; Rydberg, Bjorn

2011-07-01

To investigate γ-H2AX (phosphorylated histone H2AX) and 53BP1 (tumour protein 53 binding protein No. 1) foci formation and removal in proliferating and non-proliferating human mammary epithelial cells (HMEC) after exposure to sparsely and densely ionising radiation under different cell culture conditions. HMEC cells were grown either as monolayers (2D) or in extracellular matrix to allow the formation of acinar structures in vitro (3D). Foci numbers were quantified by image analysis at various time points after exposure. Our results reveal that in non-proliferating cells under 2D and 3D cell culture conditions, iron-ion induced γ-H2AX foci were still present at 72 h after exposure, although 53BP1 foci returned to control levels at 48 h. In contrast in proliferating HMEC, both γ-H2AX and 53BP1 foci decreased to control levels during the 24-48 h time interval after irradiation under 2D conditions. Foci numbers decreased faster after γ-ray irradiation and returned to control levels by 12 h regardless of marker, cell proliferation status, and cell culture condition. The disappearance of radiation-induced γ-H2AX and 53BP1 foci in HMEC has different dynamics that depend on radiation quality and proliferation status. Notably, the general patterns do not depend on the cell culture condition (2D versus 3D). We speculate that the persistent γ-H2AX foci in iron-ion irradiated non-proliferating cells could be due to limited availability of double-strand break (DSB) repair pathways in G0/G1-phase, or that repair of complex DSB requires replication or chromatin remodelling.

Effect of borax on immune cell proliferation and sister chromatid exchange in human chromosomes

PubMed Central

Pongsavee, Malinee

2009-01-01

Background Borax is used as a food additive. It becomes toxic when accumulated in the body. It causes vomiting, fatigue and renal failure. Methods The heparinized blood samples from 40 healthy men were studied for the impact of borax toxicity on immune cell proliferation (lymphocyte proliferation) and sister chromatid exchange in human chromosomes. The MTT assay and Sister Chromatid Exchange (SCE) technic were used in this experiment with the borax concentrations of 0.1, 0.15, 0.2, 0.3 and 0.6 mg/ml. Results It showed that the immune cell proliferation (lymphocyte proliferation) was decreased when the concentrations of borax increased. The borax concentration of 0.6 mg/ml had the most effectiveness to the lymphocyte proliferation and had the highest cytotoxicity index (CI). The borax concentrations of 0.15, 0.2, 0.3 and 0.6 mg/ml significantly induced sister chromatid exchange in human chromosomes (P < 0.05). Conclusion Borax had effects on immune cell proliferation (lymphocyte proliferation) and induced sister chromatid exchange in human chromosomes. Toxicity of borax may lead to cellular toxicity and genetic defect in human. PMID:19878537

Estrogen receptor beta signaling inhibits PDGF induced human airway smooth muscle proliferation.

PubMed

Ambhore, Nilesh Sudhakar; Katragadda, Rathnavali; Raju Kalidhindi, Rama Satyanarayana; Thompson, Michael A; Pabelick, Christina M; Prakash, Y S; Sathish, Venkatachalem

2018-04-20

Airway smooth muscle (ASM) cell hyperplasia driven by persistent inflammation is a hallmark feature of remodeling in asthma. Sex steroid signaling in the lungs is of considerable interest, given epidemiological data showing more asthma in pre-menopausal women and aging men. Our previous studies demonstrated that estrogen receptor (ER) expression increases in asthmatic human ASM; however, very limited data are available regarding differential roles of ERα vs. ERβ isoforms in human ASM cell proliferation. In this study, we evaluated the effect of selective ERα and ERβ modulators on platelet-derived growth factor (PDGF)-stimulated ASM proliferation and the mechanisms involved. Asthmatic and non-asthmatic primary human ASM cells were treated with PDGF, 17β-estradiol, ERα-agonist and/or ERβ-agonist and/or G-protein-coupled estrogen receptor 30 (GPR30/GPER) agonist and proliferation was measured using MTT and CyQuant assays followed by cell cycle analysis. Transfection of small interfering RNA (siRNA) ERα and ERβ significantly altered the human ASM proliferation. The specificity of siRNA transfection was confirmed by Western blot analysis. Gene and protein expression of cell cycle-related antigens (PCNA and Ki67) and C/EBP were measured by RT-PCR and Western analysis, along with cell signaling proteins. PDGF significantly increased ASM proliferation in non-asthmatic and asthmatic cells. Treatment with PPT showed no significant effect on PDGF-induced proliferation, whereas WAY interestingly suppressed proliferation via inhibition of ERK1/2, Akt, and p38 signaling. PDGF-induced gene expression of PCNA, Ki67 and C/EBP in human ASM was significantly lower in cells pre-treated with WAY. Furthermore, WAY also inhibited PDGF-activated PCNA, C/EBP, cyclin-D1, and cyclin-E. Overall, we demonstrate ER isoform-specific signaling in the context of ASM proliferation. Activation of ERβ can diminish remodeling in human ASM by inhibiting pro-proliferative signaling pathways

Role of YAP activation in nuclear receptor CAR-mediated proliferation of mouse hepatocytes.

PubMed

Abe, Taiki; Amaike, Yuto; Shizu, Ryota; Takahashi, Miki; Kano, Makoto; Hosaka, Takuomi; Sasaki, Takamitsu; Kodama, Susumu; Matsuzawa, Atsushi; Yoshinari, Kouichi

2018-06-08

Constitutive androstane receptor (CAR) is a xenobiotic-responsive nuclear receptor that is highly expressed in the liver. CAR activation induces hepatocyte proliferation and hepatocarcinogenesis in rodents, but the mechanisms remain unclear. In this study, we investigated the association of CAR-dependent cell proliferation with Yes-associated protein (YAP), which is a transcriptional cofactor controlling organ size and cell growth through the interaction with various transcriptional factors including TEAD. In mouse livers, TCPOBOP (a mouse CAR activator) treatment increased the nuclear YAP accumulation and mRNA levels of YAP target genes as well as cell-cycle related genes along with liver hypertrophy and verteporfin (an inhibitor of YAP/TEAD interaction) cotreatment tended to attenuate them. Furthermore, in cell-based reporter gene assays, CAR activation enhanced the YAP/TEAD-dependent transcription. To investigate the role of YAP/TEAD activation in the CAR-dependent hepatocyte proliferation, we sought to establish an in vitro system completely reproducing CAR-dependent cell proliferation. Since CAR was only slightly expressed in cultured mouse primary hepatocytes compared to mouse livers and no proliferation was observed after treatment with TCPOBOP, we overexpressed CAR using mouse CAR expressing adenovirus (Ad-mCAR-V5) in mouse primary hepatocytes. Ad-mCAR-V5 infection and TCPOBOP treatment induced hepatocyte proliferation. Similar results were obtained with immortalized normal mouse hepatocytes as well. In the established in vitro system, CAR-dependent proliferation was strongly inhibited by Yap knockdown and completely abolished by verteporfin treatment. Our present results obtained in in vivo and in vitro experiments suggest that YAP/TEAD activation plays key roles in CAR-dependent proliferation of murine hepatocytes.

[Cordyceps sinensis enhances lymphocyte proliferation and CD markers expression in simulated microgravity environment].

PubMed

Hao, Tong; Li, Jun-Jie; Du, Zhi-Yan; Duan, Cui-Mi; Wang, Yan-Meng; Wang, Chang-Yong; Song, Jing-Ping; Wang, Lin-Jie; Li, Ying-Hui; Wang, Yan

2012-10-01

This study was aimed to explore the effect of cordyceps sinensis enhancing lymphocyte proliferation and surface CD marker expression in simulated microgravity environment. The splenic lymphocytes were separated from mice and cultured in the rotary cell culture system simulated microgravity environment. The cells were treated with different concentration of cordyceps sinensis solution (0, 6.25, 12.5, 25 and 50 µg/ml) for 24, 48 and 72 h respectively, then the cells were harvested, and analyzed for cell proliferation and the expression of cell surface markers (CD4 and CD8). The results showed that under simulated microgravity environment, the lymphocyte proliferation was inhibited. When the concentration of cordyceps sinensis was 25 or 50 µg/ml, the lymphocyte proliferation, CD4 and CD8 expressions all increased, but 50 µg/ml cordyceps sinensis could inhibit the proliferation ability with the time prolonging. It is concluded that the suitable concentration of cordyceps sinensis displayed the ability to enhance the lymphocyte proliferation and CD marker expression in simulated microgravity environment. These results may be valuable for screening drugs which can be potentially against immunosuppression under simulated microgravity.

Endotoxin contamination of apolipoprotein A-I: effect on macrophage proliferation--a cautionary tale.

PubMed

Jin, Xueting; Xu, Qing; Champion, Keith; Kruth, Howard S

2015-05-01

This technical report addresses the problem of endotoxin contamination of apolipoprotein reagents. Using a bromodeoxyuridine incorporation cell proliferation assay, we observed that human plasma ApoA-I as low as 1 μg/ml resulted in a >90% inhibition in macrophage proliferation. However, not all ApoA-I from different sources showed this effect. We considered the possibility that endotoxin contamination of the apolipoproteins contributed to the differential inhibition of macrophage cell proliferation. Endotoxin alone very potently inhibited macrophage proliferation (0.1 ng/ml inhibited macrophage proliferation>90%). Measurement of endotoxin levels in the apolipoprotein products, including an analysis of free versus total endotoxin, the latter which included endotoxin that was masked due to binding to protein, suggested that free endotoxin mediated inhibition of macrophage proliferation. Despite the use of an advanced endotoxin removal procedure and agents commonly used to inhibit endotoxin action, the potency of endotoxin precluded successful elimination of endotoxin effect. Our findings show that endotoxin contamination can significantly influence apparent apolipoprotein-mediated cell effects (or effects of any other biological products), especially when these products are tested on highly endotoxin-sensitive cells, such as macrophages. Published by Elsevier Ireland Ltd.

Role of methotrexate exposure in apoptosis and proliferation during early neurulation.

PubMed

Wang, Xiuwei; Wang, Jianhua; Guan, Tao; Xiang, Qian; Wang, Mingsheng; Guan, Zhen; Li, Guannan; Zhu, Zhiqiang; Xie, Qiu; Zhang, Ting; Niu, Bo

2014-08-01

Apoptosis and proliferation play important roles in embryonic development and are required for neural tube closure. The antifolate drug methotrexate (MTX) induces folate dysmetabolism by inhibition of dihydrofolate reductase and causes abnormal apoptosis and proliferation. In this study, we established an animal model of neural tube defects (NTDs) using MTX to investigate the role of apoptosis and proliferation in NTDs caused by folate deficiency. Differential gene expressions were studied by microarray and reverse transcription-polymerase chain reaction in the NTD animal model. Results showed that 30.8% of NTDs were caused by using MTX in treatment regimens. Microarray indicated that 166 genes were significantly different between the control and NTD mice, including four apoptosis-related genes (Endog, Trp53, Casp3, Bax) and three proliferation-related genes (Ptch1, Pla2g4a, Foxg1). Levels of Endog, Trp53, Casp3, Bax (fold change>1.5) were upregulated but Ptch1, Pla2g4a, Foxg1 (fold change<0.67) were downregulated (P<0.05). These results were confirmed by reverse transcription-polymerase chain reaction. TUNEL, immunohistochemical assays and Western blot were further used to detect apoptosis and proliferation in the NTD animal model. It was found that apoptosis in neuroepithelial cells was increased as determined by TUNEL (P<0.05). Expressions of caspase-3 were significantly enhanced (P<0.05) but expressions of phosphohistone H3 were greatly decreased (P<0.05). These results concluded that MTX caused a folate and folate-associated dysmetabolism, and further induced abnormal apoptosis and proliferation, which may play a critical role in the occurrence of NTDs caused by folate deficiency. Copyright © 2013 John Wiley & Sons, Ltd.

Immunohistochemical study of calretinin in normal skin and cutaneous adnexal proliferations.

PubMed

González-Guerra, Elena; Kutzner, Heinz; Rutten, Arno; Requena, Luis

2012-07-01

Calretinin is a calcium-binding protein member of the EF-hand family. The presence of calretinin has been demonstrated in certain stages of the cellular cycle in a wide variety of normal and neoplastic tissues. The main aims of our study were (1) to investigate what structures of the normal skin and cutaneous adnexal proliferations express immunoreactivity for calretinin and (2) to determine the value of immunohistochemical expression for calretinin as a marker for follicular, sebaceous, apocrine, and eccrine differentiation in cutaneous adnexal proliferations. We studied 139 biopsy specimens, including 10 cases of normal skin of different locations and 129 benign and malignant cutaneous adnexal proliferations. In normal skin, we found that calretinin is expressed in the innermost cell layer of the outer root sheath in anagen hair follicle, in both the duct and sebolemma of the sebaceous gland, in the secretory portion of eccrine glands, and in mast cells of the stroma. In cutaneous adnexal proliferations, we found strong immunoreactivity for calretinin in tricholemmal cysts, tricholemmomas/inverted follicular keratoses, tumors of follicular infundibulum, and in some basal cell carcinomas. Focal positivity was also seen in trichoadenomas, trichoblastomas/trichoepitheliomas, pilomatricomas, proliferating tricholemmal tumors, pilar sheath acanthomas, trichofolliculomas, follicular hybrid cysts, cutaneous mixed tumors, steatocystomas, sebaceous hyperplasias, and sebaceomas. These results demonstrate that immunohistochemical study for calretinin may be helpful to identify the innermost cell layer of the outer root sheath in anagen hair follicle and the cutaneous adnexal proliferations showing differentiation toward this structure. Calretinin immunoreactivity supports eccrine differentiation in some sweat gland neoplasms, and it is also useful in identifying neoplasms with ductal sebaceous differentiation.

Enhancing BWR proliferation resistance fuel with minor actinides

NASA Astrophysics Data System (ADS)

Chang, Gray S.

2009-03-01

To reduce spent fuel for storage and enhance the proliferation resistance for the intermediate-term, there are two major approaches (a) increase the discharged spent fuel burnup in the advanced light water reactor- LWR (Gen-III Plus), which not only can reduce the spent fuel for storage, but also increase the 238Pu isotopes ratio to enhance the proliferation resistance, and (b) use of transuranic nuclides ( 237Np and 241Am) in the high burnup fuel, which can drastically increase the proliferation resistance isotope ratio of 238Pu/Pu. For future advanced nuclear systems, minor actinides (MA) are viewed more as a resource to be recycled, and transmuted to less hazardous and possibly more useful forms, rather than simply disposed of as a waste stream in an expensive repository facility. As a result, MAs play a much larger part in the design of advanced systems and fuel cycles, not only as additional sources of useful energy, but also as direct contributors to the reactivity control of the systems into which they are incorporated. In the study, a typical boiling water reactor (BWR) fuel unit lattice cell model with UO 2 fuel pins will be used to investigate the effectiveness of minor actinide reduction approach (MARA) for enhancing proliferation resistance and improving the fuel cycle performance in the intermediate-term goal for future nuclear energy systems. To account for the water coolant density variation from the bottom (0.76 g/cm 3) to the top (0.35 g/cm 3) of the core, the axial coolant channel and fuel pin were divided to 24 nodes. The MA transmutation characteristics at different elevations were compared and their impact on neutronics criticality discussed. The concept of MARA, which involves the use of transuranic nuclides ( 237Np and/or 241Am), significantly increases the 238Pu/Pu ratio for proliferation resistance, as well as serves as a burnable absorber to hold-down the initial excess reactivity. It is believed that MARA can play an important role in

Dyon proliferation in interacting quantum spin Hall edges

NASA Astrophysics Data System (ADS)

Lee, Shu-Ping; Maciejko, Joseph

We show that a quantum spin Hall system with intra-edge multiparticle backscattering and inter-edge exchange interactions exhibits a modular invariant zero-temperature phase diagram. We establish this through mapping to a classical 2D Coulomb gas with electrically and magnetically charged particles; strong coupling phases in the quantum edge problem correspond to the proliferation of various dyons in the Coulomb gas. Distinct dyon proliferated phases can be accessed by tuning the edge Luttinger parameters, for example using a split gate geometry. This research was supported by NSERC Grant #RGPIN-2014-4608, the Canada Research Chair Program (CRC) and the Canadian Institute for Advanced Research (CIFAR).

Iran and Iraq - the proliferation challenge. Strategic research report

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

Jordan, F.R.

1996-04-15

Worldwide proliferation of weapons of mass destruction and ballistic missiles has been on the rise since the end of the Cold War. This escalation has brought a new set of challenges to post-Cold War strategists and policymakers. This study focus on the impact of nuclear proliferation in the Middle East. It assesses the possibility of Iran`s and Iraq`s ability to develop a nuclear capability within the next twenty to thirty years. United States` strategy and policy to counter this potential is also considered.

Ethylene Inhibits Cell Proliferation of the Arabidopsis Root Meristem1[OPEN

PubMed Central

Street, Ian H.; Aman, Sitwat; Zubo, Yan; Ramzan, Aleena; Wang, Xiaomin; Shakeel, Samina N.; Kieber, Joseph J.; Schaller, G. Eric

2015-01-01

The root system of plants plays a critical role in plant growth and survival, with root growth being dependent on both cell proliferation and cell elongation. Multiple phytohormones interact to control root growth, including ethylene, which is primarily known for its role in controlling root cell elongation. We find that ethylene also negatively regulates cell proliferation at the root meristem of Arabidopsis (Arabidopsis thaliana). Genetic analysis indicates that the inhibition of cell proliferation involves two pathways operating downstream of the ethylene receptors. The major pathway is the canonical ethylene signal transduction pathway that incorporates CONSTITUTIVE TRIPLE RESPONSE1, ETHYLENE INSENSITIVE2, and the ETHYLENE INSENSITIVE3 family of transcription factors. The secondary pathway is a phosphorelay based on genetic analysis of receptor histidine kinase activity and mutants involving the type B response regulators. Analysis of ethylene-dependent gene expression and genetic analysis supports SHORT HYPOCOTYL2, a repressor of auxin signaling, as one mediator of the ethylene response and furthermore, indicates that SHORT HYPOCOTYL2 is a point of convergence for both ethylene and cytokinin in negatively regulating cell proliferation. Additional analysis indicates that ethylene signaling contributes but is not required for cytokinin to inhibit activity of the root meristem. These results identify key elements, along with points of cross talk with cytokinin and auxin, by which ethylene negatively regulates cell proliferation at the root apical meristem. PMID:26149574

PET imaging of proliferation with pyrimidines.

PubMed

Tehrani, Omid S; Shields, Anthony F

2013-06-01

Several new tracers are being developed for use with PET to assess pathways that are altered in cancers, including energy use, cellular signaling, transport, and proliferation. Because increased proliferation is a hallmark of many cancers, several tracers have been tested to track the DNA synthesis pathway. Thymidine, which is incorporated into DNA but not RNA, has been used in laboratory studies to measure tumor growth. Because thymidine labeled with (11)C undergoes rapid biologic degradation and has a short physical half-life, tracers labeled with (18)F have been preferred in PET imaging. One such tracer is (18)F-labeled 3'-deoxy-3'-fluorothymidine ((18)F-FLT). (18)F-FLT is trapped after phosphorylation by thymidine kinase 1, whose expression is increased in replicating cells. Several studies on breast, lung, and brain tumors have demonstrated that retention of (18)F-FLT correlated with tumor proliferation. Although (18)F-FLT has been used to image and stage several tumor types, the standardized uptake value is generally lower than that obtained with (18)F-FDG. (18)F-FLT can be used to image many areas of the body, but background uptake is high in the liver, marrow, and renal system, limiting use in these organs. (18)F-FLT PET imaging has primarily been studied in the assessment of treatment response. Rapid declines in (18)F-FLT retention within days to weeks have been demonstrated in several tumor types treated with cytotoxic drugs, targeted agents, and radiotherapy. Further work is ongoing to validate this approach and determine its utility in the development of new drugs and in the clinical evaluation of standard treatment approaches.

Cell proliferation is a key determinant of the outcome of FOXO3a activation

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

Poulsen, Raewyn C., E-mail: raewyn.poulsen@gmail.com; Carr, Andrew J.; Hulley, Philippa A.

2015-06-19

The FOXO family of forkhead transcription factors have a pivotal role in determining cell fate in response to oxidative stress. FOXO activity can either promote cell survival or induce cell death. Increased FOXO-mediated cell death has been implicated in the pathogenesis of degenerative diseases affecting musculoskeletal tissues. The aim of this study was to determine the conditions under which one member of the FOXO family, FOXO3a, promotes cell survival as opposed to cell death. Treatment of primary human tenocytes with 1 pM hydrogen peroxide for 18 h resulted in increased protein levels of FOXO3a. In peroxide-treated cells cultured in low serum media,more » FOXO3a inhibited cell proliferation and protected against apoptosis. However in peroxide treated cells cultured in high serum media, cell proliferation was unchanged but level of apoptosis significantly increased. Similarly, in tenocytes transduced to over-express FOXO3a, cell proliferation was inhibited and level of apoptosis unchanged in cells cultured in low serum. However there was a robust increase in cell death in FOXO3a-expressing cells cultured in high serum. Inhibition of cell proliferation in either peroxide-treated or FOXO3a-expressing cells cultured in high serum protected against apoptosis induction. Conversely, addition of a Chk2 inhibitor to peroxide-treated or FOXO3a-expressing cells overrode the inhibitory effect of FOXO3a on cell proliferation and led to increased apoptosis in cells cultured in low serum. This study demonstrates that proliferating cells may be particularly susceptible to the apoptosis-inducing actions of FOXO3a. Inhibition of cell proliferation by FOXO3a may be a critical event in allowing the pro-survival rather than the pro-apoptotic activity of FOXO3a to prevail. - Highlights: • FOXO3a activity can result in either promotion of cell survival or apoptosis. • The outcome of FOXO3a activation differs in proliferating compared to non-proliferating cells. �

Orlistat Reduces Proliferation and Enhances Apoptosis in Human Pancreatic Cancer Cells (PANC-1).

PubMed

Sokolowska, Ewa; Presler, Malgorzata; Goyke, Elzbieta; Milczarek, Ryszard; Swierczynski, Julian; Sledzinski, Tomasz

2017-11-01

Pancreatic cancer is a disease with very poor prognosis, and none of currently available pharmacotherapies have proven to be efficient in this indication. The aim of this study was to analyze the expression of fatty acid synthase (FASN) gene as a potential therapeutic target in proliferating human pancreatic cancer cells (PANC-1), and verify if orlistat, originally developed as an anti-obesity drug, inhibits PANC-1 proliferation. The effects of orlistat on gene expression, lipogenesis, proliferation and apoptosis was studied in PANC-1 cell culture. Expression of FASN increased during proliferation of PANC-1. Inhibition of FASN by orlistat resulted in a significant reduction of PANC-1 proliferation and enhanced apoptosis of these cells. This study showed, to our knowledge for the first time, that orlistat exhibits significant antitumor activity against PANC-1 cells. This implies that orlistat analogs with good oral bioavailability may find application in pharmacotherapy of pancreatic cancer. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Cortisol reduces cell proliferation in the telencephalon of rainbow trout (Oncorhynchus mykiss).

PubMed

Sørensen, Christina; Bohlin, Linda C; Øverli, Øyvind; Nilsson, Göran E

2011-03-28

The fish brain grows throughout life, and new cells are added continuously in all major brain areas. As in mammals, the rate of adult brain cell proliferation in fish can be regulated by external factors including environmental complexity and interaction with conspecifics. We have recently demonstrated that the stress experienced by subordinate rainbow trout in social hierarchies leads to a marked suppression of brain cell proliferation in the telencephalon, and that this is accompanied by an increase in plasma levels of cortisol. Corticosteroid hormones are known to suppress adult neurogenesis in mammals, and to investigate whether this is also the case in fish, rainbow trout were fed feed containing either a low or a high dose of cortisol for 6 days. Compared to control animals receiving regular feed, both cortisol treated groups had significantly elevated cortisol levels 24h after the last feeding, with the high group having levels comparable to those previously reported in socially stressed fish. To quantify cell proliferation, immunohistochemistry for proliferating cell nuclear antigen (PCNA) was performed to identify actively cycling cells. The density of PCNA-positive nuclei in the telencephalon was reduced by about 50% in both cortisol treated groups. The effect of cortisol on brain cell proliferation did not reflect a general down regulation of growth, as only the high cortisol group had reduced growth rate, and there was no correlation between brain cell proliferation and growth rate in any group. These results indicate that the reduced proliferative activity seen in brains of socially stressed fish is mediated by cortisol, and that there is a similar suppressive effect of cortisol on brain cell proliferation in the teleost forebrain as in the mammalian hippocampus. Copyright © 2010 Elsevier Inc. All rights reserved.

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

Uterine epithelial cell proliferation and endometrial hyperplasia: evidence from a mouse model

PubMed Central

Gao, Yang; Li, Shu; Li, Qinglei

2014-01-01

In the uterus, epithelial cell proliferation changes during the estrous cycle and pregnancy. Uncontrolled epithelial cell proliferation results in implantation failure and/or cancer development. Transforming growth factor-β (TGF-β) signaling is a fundamental regulator of diverse biological processes and is indispensable for multiple reproductive functions. However, the in vivo role of TGF-β signaling in uterine epithelial cells remains poorly defined. We have shown that in the uterus, conditional deletion of the Type 1 receptor for TGF-β (Tgfbr1) using anti-Müllerian hormone receptor type 2 (Amhr2) Cre leads to myometrial defects. Here, we describe enhanced epithelial cell proliferation by immunostaining of Ki67 in the uteri of these mice. The aberration culminated in endometrial hyperplasia in aged females. To exclude the potential influence of ovarian steroid hormones, the proliferative status of uterine epithelial cells was assessed following ovariectomy. Increased uterine epithelial cell proliferation was also revealed in ovariectomized Tgfbr1 Amhr2-Cre conditional knockout mice. We further demonstrated that transcript levels for fibroblast growth factor 10 (Fgf10) were markedly up-regulated in Tgfbr1 Amhr2-Cre conditional knockout uteri. Consistently, treatment of primary uterine stromal cells with TGF-β1 significantly reduced Fgf10 mRNA expression. Thus, our findings suggest a potential involvement of TGFBR1-mediated signaling in the regulation of uterine epithelial cell proliferation, and provide genetic evidence supporting the role of uterine epithelial cell proliferation in the pathogenesis of endometrial hyperplasia. PMID:24770950

Apoptosis and proliferation of oligodendrocyte progenitor cells in the irradiated rodent spinal cord

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

Atkinson, Shelley L.; Li Yuqing; Wong, C. Shun

2005-06-01

Purpose: Oligodendrocytes undergo early apoptosis after irradiation. The aim of this study was to determine the relationship between oligodendroglial apoptosis and proliferation of oligodendrocyte progenitor cells (OPC) in the irradiated central nervous system. Methods and Materials: Adult rats and p53 transgenic mice were given single doses of 2 Gy, 8 Gy, or 22 Gy to the cervical spinal cord. Apoptosis was assessed using TUNEL (Tdt-mediated dUTP terminal nick-end labeling) staining or by examining nuclear morphology. Oligodendrocyte progenitor cells were identified with an NG2 antibody or by in situ hybridization for platelet-derived growth factor receptor {alpha}. Proliferation of OPC was assessedmore » by in vivo bromodeoxyuridine (BrdU) labeling and subsequent immunohistochemistry. Because radiation-induced apoptosis of oligodendroglial cells is p53 dependent, p53 transgenic mice were used to study the relationship between apoptosis and cell proliferation. Results: Oligodendrocyte progenitor cells underwent apoptosis within 24 h of irradiation in the rat. That did not result in a change in OPC density at 24 h. Oligodendrocyte progenitor cell density was significantly reduced by 2-4 weeks, but showed recovery by 6 weeks after irradiation. An increase in BrdU-labeled cells was observed at 2 weeks after 8 Gy or 22 Gy, and proliferating cells in the rat spinal cord were immunoreactive for NG2. The mouse spinal cord showed a similar early cell proliferation after irradiation. No difference was observed in the proliferation response in the spinal cord of p53 -/- mice compared with wild type animals. Conclusions: Oligodendroglial cells undergo early apoptosis and OPC undergo early proliferation after ionizing radiation. However, apoptosis is not likely to be the trigger for early proliferation of OPC in the irradiated central nervous system.« less

Weapons proliferation and organized crime: The Russian military and security force dimension

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

Turbiville, G.H.

One dimension of international security of the post-Cold War era that has not received enough attention is how organized crime facilitates weapons proliferation worldwide. The former Soviet Union (FSU) has emerged as the world`s greatest counterproliferation challenge. It contains the best developed links among organized crime, military and security organizations, and weapons proliferation. Furthermore, Russian military and security forces are the principle source of arms becoming available to organized crime groups, participants in regional conflict, and corrupt state officials engaged in the black, gray, and legal arms markets in their various dimensions. The flourishing illegal trade in conventional weapons ismore » the clearest and most tangible manifestation of the close links between Russian power ministries and criminal organizations. The magnitude of the WMD proliferation problem from the FSU is less clear and less tangible. There have been many open reports of small-scale fissile material smuggling out of the FSU. The situation with regard to the proliferation of chemical weapon usually receives less attention but may be more serious. With an acknowledged stockpile of 40,000 metric tons of chemical agents, the potential for proliferation is enormous.« less

The Nuclear Non-Proliferation Treaty: Regulating Nuclear Weapons around the World

ERIC Educational Resources Information Center

Middleton, Tiffany Willey

2010-01-01

In May 2010, scientists, national security experts, and state delegates from nations around the world will convene in New York for the 2010 Nuclear Non-Proliferation Treaty Review Conference. They will review current guidelines for nuclear testing and possession of nuclear weapons in accordance with the Nuclear Non-Proliferation Treaty of 1968,…

Proliferation of the Golgi apparatus in tobacco BY-2 cells during cell proliferation after release from the stationary phase of growth.

PubMed

Abiodun, Moses; Matsuoka, Ken

2013-08-01

We have recently developed a new method aimed at mass photo-conversion of photo-convertible fluorescence protein (PFP) fluorescence in transformed tobacco BY-2 cells. Using this method we reported recently that the Golgi apparatus is generated by the de novo formation from ER and the division of pre-existing Golgi stacks with similar extents In this work we report that the proliferation of the Golgi apparatus in tobacco cells that enter the growing cycle from the non-dividing cycle is quite similar to that in rapidly growing cells and that de novo formation from the ER and division of pre-existing stacks seems to contribute almost equally to the proliferation.

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.

Limiting nuclear proliferation

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

Gordon, L.; Cecelski, L.

1978-01-01

As a result of the 1977 experience, it is shown that the U.S. no longer dominates the world nuclear market and must change its approach from coercion to persuasion. President Carter, implementing his campaign promises on nuclear nonproliferation, has used direct pressure, negotiated with nuclear suppliers, and asked for legislation to impose rigid criteria for the export of nuclear materials. Unilateral actions included the deferment of facilities for fuel reprocessing and breeder reactors, but were followed by efforts for international cooperation as the year progressed. While global non-proliferation policies reinforced with international technical cooperation are seen as admirable goals, themore » response to U.S. initiatives is not seen to be encouraging.« less

Effect of PGE2 on thymocyte proliferation induced by Con A or IL-4 + PMA.

PubMed

Daculsi, R; Vaillier, D; Bezian, J H; Gualde, N

1993-02-01

Prostaglandin E2 (PGE2) is known to inhibit peripheral T-lymphocyte and thymocyte proliferation activated by antigens, mitogens or anti-CD3 antibodies. In this study, we have investigated, the effect of PGE2 on thymocyte proliferation induced by the combination of IL-4 plus PMA. PGE2 inhibits the proliferation of thymocytes activated by ConA, whatever the culture period; in contrast PGE2 shifts the kinetics of thymocyte proliferation after stimulation by IL-4 plus PMA, but does not sustain the proliferation beyond day 3. This effect depends upon cell density, IL-4 concentration and on the time that PGE2 is added to the culture. By use of the cAMP inducer, forskolin, or a cAMP analog, db-cAMP, we observed the same results, PGE2 increases the proliferation of CD8+ corticoresistant thymocytes (CRT) activated by IL-4 plus PMA, but inhibits that of CD4+ CRT. These results suggest that PGE2 can regulate thymocyte proliferation differently according to the activation pathway and the thymic subpopulations.

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.

Proliferation zones in the axolotl brain and regeneration of the telencephalon.

PubMed

Maden, Malcolm; Manwell, Laurie A; Ormerod, Brandi K

2013-01-17

Although the brains of lower vertebrates are known to exhibit somewhat limited regeneration after incisional or stab wounds, the Urodele brain exhibits extensive regeneration after massive tissue removal. Discovering whether and how neural progenitor cells that reside in the ventricular zones of Urodeles proliferate to mediate tissue repair in response to injury may produce novel leads for regenerative strategies. Here we show that endogenous neural progenitor cells resident to the ventricular zone of Urodeles spontaneously proliferate, producing progeny that migrate throughout the telencephalon before terminally differentiating into neurons. These progenitor cells appear to be responsible for telencephalon regeneration after tissue removal and their activity may be up-regulated by injury through an olfactory cue. There is extensive proliferation of endogenous neural progenitor cells throughout the ventricular zone of the adult axolotl brain. The highest levels are observed in the telencephalon, especially the dorsolateral aspect, and cerebellum. Lower levels are observed in the mesencephalon and rhombencephalon. New cells produced in the ventricular zone migrate laterally, dorsally and ventrally into the surrounding neuronal layer. After migrating from the ventricular zone, the new cells primarily express markers of neuronal differentiative fates. Large-scale telencephalic tissue removal stimulates progenitor cell proliferation in the ventricular zone of the damaged region, followed by proliferation in the tissue that surrounds the healing edges of the wound until the telencephalon has completed regeneration. The proliferative stimulus appears to reside in the olfactory system, because telencephalic regeneration does not occur in the brains of olfactory bulbectomized animals in which the damaged neural tissue simply heals over. There is a continual generation of neuronal cells from neural progenitor cells located within the ventricular zone of the axolotl brain

Gab3 is required for human colorectal cancer cell proliferation

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

Xiang, Shihao; Wang, Na; Hui, Pingping

Here, we focused on the potential function of Gab3, an uncommon Gab family protein, in human colorectal cancer (CRC) cells. We found that Gab3 was only expressed in human colon cancer tissues as well as in established (HCT-116 and HT-29 lines) and primary human CRC cells. It was however absent in normal human colon cancer tissues and in FHC colon epithelial cells. Knockdown of Gab3 by targeted-shRNAs inhibited proliferation of the CRC cells. Reversely, exogenous over-expression of Gab3 promoted CRC cell proliferation. At the signaling level, Gab3 co-precipitated with p85 and SHP2 in CRC cells, which was required for subsequentmore » Akt and Erk activation. Gab3 shRNA knockdown inhibited Akt and Erk activation, yet Gab3 over-expression augmented it. In vivo, HCT-116 xenograft tumor growth in severe combined immune deficient (SCID) mice was suppressed following expressing Gab3 shRNAs. Meanwhile, Akt and Erk activation in Gab3 shRNA-expressing tumors was also largely inhibited. Together, our results suggest that Gab3 expression in CRC cells is important for Akt-Erk activation and cell proliferation. - Highlights: • Gab3 is only expressed in colorectal cancer (CRC) cells, but not in colon epithelial cells. • Gab3 shRNA knockdown inhibits CRC cell proliferation. • Exogenous over-expression of Gab3 promotes HCT-116 cell proliferation. • Gab3 co-precipitates with p85 and SHP2 to mediate Akt and Erk activation in CRC cells. • HCT-116 tumor growth in SCID mice is suppressed with expression of Gab3 shRNAs.« less

Elevated circulating IGF-I promotes mammary gland development and proliferation.

PubMed

Cannata, Dara; Lann, Danielle; Wu, Yingjie; Elis, Sebastien; Sun, Hui; Yakar, Shoshana; Lazzarino, Deborah A; Wood, Teresa L; Leroith, Derek

2010-12-01

Animal studies have shown that IGF-I is essential for mammary gland development. Previous studies have suggested that local IGF-I rather than circulating IGF-I is the major mediator of mammary gland development. In the present study we used the hepatic IGF-I transgenic (HIT) and IGF-I knockout/HIT (KO-HIT) mouse models to examine the effects of enhanced circulating IGF-I on mammary development in the presence and absence of local IGF-I. HIT mice express the rat IGF-I transgene under the transthyretin promoter in the liver and have elevated circulating IGF-I and normal tissue IGF-I levels. The KO-HIT mice have no tissue IGF-I and increased circulating IGF-I. Analysis of mammary gland development reveals a greater degree of complexity in HIT mice as compared to control and KO-HIT mice, which demonstrate similar degrees of mammary gland complexity. Immunohistochemical evaluation of glands of HIT mice also suggests an enhanced degree of proliferation of the mammary gland, whereas KO-HIT mice exhibit mammary gland proliferation similar to control mice. In addition, HIT mice have a higher percentage of proliferating myoepithelial and luminal cells than control mice, whereas KO-HIT mice have an equivalent percentage of proliferating myoepithelial and luminal cells as control mice. Thus, our findings show that elevated circulating IGF-I levels are sufficient to promote normal pubertal mammary epithelial development. However, HIT mice demonstrate more pronounced mammary gland development when compared to control and KO-HIT mice. This suggests that both local and endocrine IGF-I play roles in mammary gland development and that elevated circulating IGF-I accelerates mammary epithelial proliferation.

Curcumin and docosahexaenoic acid block insulin-induced colon carcinoma cell proliferation.

PubMed

Fenton, Jenifer I; McCaskey, Sarah J

2013-03-01

Diets high in fish and curcumin are associated with a decreased risk of CRC. Insulin resistance and obesity are associated with increased CRC risk and higher reoccurrence rates. We utilized cell culture to determine if dietary compounds could reduce insulin-induced cell proliferation comparing the response in normal and metastatic colon epithelial cells. We treated model normal murine colon epithelial cells (YAMC) and adenocarcinoma cells (MC38) with docosahexaenoic acid (DHA) or curcumin alone and then co-treatments of the diet-derived compound and insulin were combined. Cell proliferation was stimulated with insulin (1 ug/mL) to model insulin resistance in obesity. Despite the presence of insulin, proliferation was reduced in the MC38 cells treated with 10 μM curcumin (p<0.001) and 50 μM DHA (p<0.001). Insulin stimulated MAPK and MEK phosphorylation was inhibited by DHA and curcumin in MC38 cancer cells. Here we show that curcumin and DHA can block insulin-induced colon cancer cell proliferation in vitro via a MEK mediated mechanism. Copyright © 2012 Elsevier Ltd. All rights reserved.

E-cadherin interactions regulate beta-cell proliferation in islet-like structures.

PubMed

Carvell, Melanie J; Marsh, Phil J; Persaud, Shanta J; Jones, Peter M

2007-01-01

Islet function is dependent on cells within the islet interacting with each other. E-cadherin (ECAD) mediates Ca(2+)-dependent homophilic cell adhesion between b-cells within islets and has been identified as a tumour suppressor. We generated clones of the MIN6 beta-cell line that stably over- (S) and under-express (alphaS) ECAD. Modified expression of ECAD was confirmed by quantitative RT-PCR, immunoblotting and immunocytochemistry. Preproinsulin mRNA, insulin content and basal rates of insulin secretion were higher in S cells compared to aS and control (V) cells. However, stimulated insulin secretory responses were unaffected by ECAD expression levels. ECAD expression did affect proliferation, with enhanced ECAD expression being associated with reduced proliferation and vice versa. Formation of islet-like structures was associated with a significant reduction in proliferation of V and S cells but not alphaS cells. These data suggest that ECAD expression levels do not modulate insulin secretory function but are consistent with a role for ECAD in the regulation of beta-cell proliferation. Copyright (c) 2007 S. Karger AG, Basel.

Effects of sulforaphane on neural stem cell proliferation and differentiation.

PubMed

Han, Zhenxian; Xu, Qian; Li, Changfu; Zhao, Hong

2017-03-01

Sulforaphane (SFN) is a natural organosulfur compound with anti-oxidant and anti-inflammation properties. The objective of this study is to investigate the effect of SFN on the proliferation and differentiation of neural stem cells (NSC). NSCs were exposed to SFN at the concentrations ranging from 0.25 to 10 µM. Cell viability was evaluated with MTT assay and lactate dehydogenase (LDH) release assay. The proliferation of NSCs was evaluated with neurosphere formation assay and Ki-67 staining. The level of Tuj-1 was evaluated with immunostaining and Western blot to assess NSC neuronal differentiation. The expression of key proteins in the Wnt signaling pathway, including β-catenin and cyclin D1, in response to SFN treatment or the Wnt inhibitor, DKK-1, was determined by Western blotting. No significant cytotoxicity was seen for SFN on NSCs with SFN at concentrations of less than 10 µM. On the contrary, SFN of low concentrations stimulated cell proliferation and prominently increased neurosphere formation and NSC differentiation to neurons. SFN treatment upregulated Wnt signaling in the NSCs, whereas DKK-1 attenuated the effects of SFN. SFN is a drug to promote NSC proliferation and neuronal differentiation when used at low concentrations. These protective effects are mediated by Wnt signaling pathway. © 2017 Wiley Periodicals, Inc.

Nuclear proliferation-resistance and safeguards for future nuclear fuel cycle

NASA Astrophysics Data System (ADS)

Kuno, Y.; Inoue, N.; Senzaki, M.

2009-03-01

Corresponding to the world nuclear security concerns, future nuclear fuel cycle (NFC) should have high proliferation-resistance (PR) and physical protection (PP), while promotion of the peaceful use of the nuclear energy must not be inhibited. In order to accomplish nuclear non-proliferation from NFC, a few models of the well-PR systems should be developed so that international community can recognize them as worldwide norms. To find a good balance of 'safeguard-ability (so-called extrinsic measure or institutional barrier)' and 'impede-ability (intrinsic feature or technical barrier)' will come to be essential for NFC designers to optimize civilian nuclear technology with nuclear non-proliferation, although the advanced safeguards with high detectability can still play a dominant role for PR in the states complying with full institutional controls. Accomplishment of such goal in a good economic efficiency is a future key challenge.

Arabidopsis and Tobacco SUPERMAN regulate hormone signalling and mediate cell proliferation and differentiation

PubMed Central

Nibau, Candida; Di Stilio, Verónica S.; Wu, Hen-ming; Cheung, Alice Y.

2011-01-01

Arabidopsis thaliana SUPERMAN (SUP) plays an important role during flower development by maintaining the boundary between stamens and carpels in the inner two whorls. It was proposed that SUP maintains this boundary by regulating cell proliferation in both whorls, as loss-of-function superman mutants produce more stamens at the expense of carpels. However, the cellular mechanism that underlies SUP function remains unknown. Here Arabidopsis or tobacco (Nicotiana tabacum) SUP was overexpressed in tobacco plants to substantiate SUP's role as a regulator of cell proliferation and boundary definition and provide evidence that its biological role may be mediated via hormonal changes. It was found that moderate levels of SUP stimulated cell growth and proliferation, whereas high levels were inhibitory. SUP stimulated auxin- and cytokinin-regulated processes, and cells overexpressing SUP displayed reduced hormone dependency for proliferation and regeneration into plants. SUP also induced proliferation of female traits in the second and third flower whorls and promoted differentiation of petaloid properties in sepals, further supporting a role for SUP as a boundary regulator. Moreover, cytokinin suppressed stamen development and promoted differentiation of carpeloid tissues, suggesting that SUP may regulate male and female development via its effect on cytokinin signalling. Taken together, these observations suggest a model whereby the effect of SUP on cell growth and proliferation involves the modulation of auxin- and cytokinin-regulated processes. Furthermore, differential SUP expression or different sensitivities of different cell types to SUP may determine whether SUP stimulates or suppresses their proliferation. PMID:20980362

Low-dose radiation modulates human mesenchymal stem cell proliferation through regulating CDK and Rb.

PubMed

Yang, Lei; Liu, Ziling; Chen, Chen; Cong, Xiaofeng; Li, Zhi; Zhao, Shasha; Ren, Meng

2017-01-01

Low-dose radiation (LDR) has been known to stimulate cell proliferation. The effect of LDR on human bone marrow mesenchymal stem cells (BMSCs), however, remains to be determined. The current study, therefore, aimed to investigate the effect of LDR on human BMSC proliferation and its mechanisms. To accomplish this, human BMSCs were isolated from ribs and cultured with or without exposition to LDR (75 mGy) for 24 h. Cell proliferation was assessed by MTT assay, the cytokines secreted by the BMSCs were quantified by ELISA, and the proteins associated with cell proliferation and cell cycle were evaluated by immunoblot analysis. BMSCs isolated from human ribs were capable of differentiating into osteoblasts and adipocytes. LDR stimulated human BMSC proliferation (0.580 ± 0.106 vs 0.419 ± 0.026 on day 4, P < 0.05; 0.794 ± 0.025 vs 0.689 ± 0.047 on day 7, P < 0.05) and increased S-phase proportion. LDR significantly enhanced the production of SCF, GM-CSF, and IL-11. Moreover, BMSCs modulated T-cell proliferation, and LDR further augmented the modulatory effect of BMSCs on T-cell proliferation. Cell cycle-associated proteins, such as Rb, CDK1, and CDC25B, appeared to mediate the stimulatory effect of LDR on BMSC proliferation. The findings of the current study indicate that physical stimulants, such as LDR, could be used for the large-scale expansion of human BMSCs, and thus may be used for MSC cellular therapy in clinic.

Benign endometrial proliferations mimicking malignancies: a review of problematic entities in small biopsy specimens.

PubMed

Ip, Philip Pun-Ching

2018-02-14

Benign proliferations that mimic malignancies are commonly encountered during the course of assessment of small and fragmented endometrial samples. Although benign, endometrial epithelial metaplasias often coexist with premalignant or malignant lesions causing diagnostic confusion. The difficulty with mucinous metaplasia lies in its distinction from atypical mucinous glandular proliferations and mucinous carcinomas, which are associated with significant interobserver variability. Papillary proliferation of the endometrium is commonly associated with hormonal drugs and endometrial polyps and is characterised by papillae with fibrovascular cores covered by epithelial cells without cytologic atypia. They are classified into simple or complex papillary proliferations depending on the architectural complexity and extent of proliferation. Complex papillary proliferations are associated with a high risk of concurrent or subsequent hyperplasia with atypia/carcinoma. Papillary proliferations may have coexisting epithelial metaplasias and, most commonly, mucinous metaplasia and syncytial papillary change. Those with striking mucinous metaplasia overlap morphologically with papillary mucinous metaplasia. The latter has been proposed as a precursor of endometrial mucinous carcinoma. Misinterpreting the Arias-Stella reaction as a malignant or premalignant lesion is more likely to occur if the pathologist is unaware that the patient is pregnant or on hormonal drugs. Endometrial hyperplasia with secretory changes may occasionally be difficult to distinguish from the torturous and crowded glands of a late secretory endometrium. Endometrial polyps may have abnormal features that can be misinterpreted as endometrial hyperplasia or Mullerian adenosarcoma. Awareness of these benign endometrial proliferations and their common association with hormonal medication or altered endogenous hormonal levels will help prevent the over-diagnosis of premalignant and malignant lesions.

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

Boric acid inhibits human prostate cancer cell proliferation.

PubMed

Barranco, Wade T; Eckhert, Curtis D

2004-12-08

The role of boron in biology includes coordinated regulation of gene expression in mixed bacterial populations and the growth and proliferation of higher plants and lower animals. Here we report that boric acid, the dominant form of boron in plasma, inhibits the proliferation of prostate cancer cell lines, DU-145 and LNCaP, in a dose-dependent manner. Non-tumorigenic prostate cell lines, PWR-1E and RWPE-1, and the cancer line PC-3 were also inhibited, but required concentrations higher than observed human blood levels. Studies using DU-145 cells showed that boric acid induced a cell death-independent proliferative inhibition, with little effect on cell cycle stage distribution and mitochondrial function.

Human Nanog pseudogene8 promotes the proliferation of gastrointestinal cancer cells

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

Uchino, Keita, E-mail: uchino13@intmed1.med.kyushu-u.ac.jp; Hirano, Gen; Hirahashi, Minako

2012-09-10

There is emerging evidence that human solid tumor cells originate from cancer stem cells (CSCs). In cancer cell lines, tumor-initiating CSCs are mainly found in the side population (SP) that has the capacity to extrude dyes such as Hoechst 33342. We found that Nanog is expressed specifically in SP cells of human gastrointestinal (GI) cancer cells. Nucleotide sequencing revealed that NanogP8 but not Nanog was expressed in GI cancer cells. Transfection of NanogP8 into GI cancer cell lines promoted cell proliferation, while its inhibition by anti-Nanog siRNA suppressed the proliferation. Immunohistochemical staining of primary GI cancer tissues revealed NanogP8 proteinmore » to be strongly expressed in 3 out of 60 cases. In these cases, NanogP8 was found especially in an infiltrative part of the tumor, in proliferating cells with Ki67 expression. These data suggest that NanogP8 is involved in GI cancer development in a fraction of patients, in whom it presumably acts by supporting CSC proliferation. -- Highlights: Black-Right-Pointing-Pointer Nanog maintains pluripotency by regulating embryonic stem cells differentiation. Black-Right-Pointing-Pointer Nanog is expressed in cancer stem cells of human gastrointestinal cancer cells. Black-Right-Pointing-Pointer Nucleotide sequencing revealed that Nanog pseudogene8 but not Nanog was expressed. Black-Right-Pointing-Pointer Nanog pseudogene8 promotes cancer stem cells proliferation. Black-Right-Pointing-Pointer Nanog pseudogene8 is involved in gastrointestinal cancer development.« less

Ghrelin promotes oral tumor cell proliferation by modifying GLUT1 expression.

PubMed

Kraus, Dominik; Reckenbeil, Jan; Wenghoefer, Matthias; Stark, Helmut; Frentzen, Matthias; Allam, Jean-Pierre; Novak, Natalija; Frede, Stilla; Götz, Werner; Probstmeier, Rainer; Meyer, Rainer; Winter, Jochen

2016-03-01

In our study, ghrelin was investigated with respect to its capacity on proliferative effects and molecular correlations on oral tumor cells. The presence of all molecular components of the ghrelin system, i.e., ghrelin and its receptors, was analyzed and could be detected using real-time PCR and immunohistochemistry. To examine cellular effects caused by ghrelin and to clarify downstream-regulatory mechanisms, two different oral tumor cell lines (BHY and HN) were used in cell culture experiments. Stimulation of either cell line with ghrelin led to a significantly increased proliferation. Signal transduction occurred through phosphorylation of GSK-3β and nuclear translocation of β-catenin. This effect could be inhibited by blocking protein kinase A. Glucose transporter1 (GLUT1), as an important factor for delivering sufficient amounts of glucose to tumor cells having high requirements for this carbohydrate (Warburg effect) was up-regulated by exogenous and endogenous ghrelin. Silencing intracellular ghrelin concentrations using siRNA led to a significant decreased expression of GLUT1 and proliferation. In conclusion, our study describes the role for the appetite-stimulating peptide hormone ghrelin in oral cancer proliferation under the particular aspect of glucose uptake: (1) tumor cells are a source of ghrelin. (2) Ghrelin affects tumor cell proliferation through autocrine and/or paracrine activity. (3) Ghrelin modulates GLUT1 expression and thus indirectly enhances tumor cell proliferation. These findings are of major relevance, because glucose uptake is assumed to be a promising target for cancer treatment.

The antidepressant effect of running is associated with increased hippocampal cell proliferation.

PubMed

Bjørnebekk, Astrid; Mathé, Aleksander A; Brené, Stefan

2005-09-01

A common trait of antidepressant drugs, electroconvulsive treatment and physical exercise is that they relieve depression and up-regulate neurotrophic factors as well as cell proliferation and neurogenesis in the hippocampus. In order to identify possible biological underpinnings of depression and the antidepressant effect of running, we analysed cell proliferation, the level of the neurotrophic factor BDNF in hippocampus and dynorphin in striatum/accumbens in 'depressed' Flinders Sensitive Line rats (FSL) and Flinders Resistant Line (FRL) rats with and without access to running-wheels. The FRL strain exhibited a higher daily running activity than the FSL strain. Wheel-running had an antidepressant effect in the 'depressed' FSL rats, as indicated by the forced swim test. In the hippocampus, cell proliferation was lower in the 'depressed' rats compared to the control FRL rats but there was no difference in BDNF or dynorphin levels in striatum/accumbens. After 5 wk of running, cell proliferation increased in FSL but not in FRL rats. BDNF and dynorphin mRNA levels were increased in FRL but not to the same extent in the in FSL rats; thus, increased BDNF and dynorphin levels were correlated to the running activity but not to the antidepressant effect of running. The only parameter that was associated to basal level of 'depression' and to the antidepressant effect was cell proliferation in the hippocampus. Thus, suppression of cell proliferation in the hippocampus could constitute one of the mechanisms that underlie depression, and physical activity might be an efficient antidepressant.

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.

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

Cell proliferation and apoptosis during histogenesis of the guinea pig and rabbit cerebellar cortex.

PubMed

Lossi, Laura; Coli, Alessandra; Giannessi, Elisabetta; Stornelli, Maria Rita; Marroni, Paolo

2002-01-01

Cell proliferation and apoptosis are essential for development of the nervous system. In this study we have investigated the histogenesis of the cerebellar cortex in guinea pig (a precocial species) and rabbit (an altricial species) at different stages of pregnancy and postnatal life. Proliferating cells were identified after labeling with antibodies against the proliferating cell nuclear antigen (PCNA) and/or the Ki-67 antigen. Apoptotic cells were visualized in situ by the TUNEL method and by immunodetection of cleaved caspase 3 and 9. In guinea pigs, both proliferating and apoptotic cells were detected during pre-natal life (E0-E40). Conversely, cell proliferation and apoptosis in rabbits were temporally restricted to early postnatal weeks (P0-P20). In both species cell proliferation was mainly linked to differentiation and migration of the granule cells. In both species, the majority of cells undergoing programmed cell death likely corresponded to granule cells. They were mainly detected in the external granular layer, and were by far more common than previously reported in other locations of the postnatal brain. This study shows that apoptosis is a shared process of cell death during cerebellar development in both altricial and precocial animals, and that there is a direct spatial and temporal correlation between cell proliferation and death in two mammals with different time tables in cerebellar maturation.

Proliferation of smooth muscle cells stimulated by Porphyromonas gingivalis is inhibited by apple polyphenol.

PubMed

Inaba, Hiroaki; Tagashira, Motoyuki; Kanda, Tomomasa; Amano, Atsuo

2011-11-01

Porphyromonas gingivalis (Pg) is thought to be involved in the progression of occlusive arterial lesions, whereas vascular smooth muscle cell (SMC) proliferation is considered to be involved in occlusive arterial disease. We previously showed that bacteremia caused by Pg infection induced proliferation of mouse aortic SMCs. Furthermore, human SMCs stimulated with human plasma incubated with Pg showed a marked transformation from the contractile to proliferative phenotype. In the present study, we examine the involvement of Pg gingipains and fimbriae in induction of the SMC transformation and proliferation, and effective inhibitors. Pg strains including gingipain- and fimbria-null mutants were incubated in human plasma, after which the bacteria were removed and the supernatants were added to cultured SMCs. To evaluate the effects of inhibitors, Pg organisms were incubated in plasma in the presence of apple polyphenol (AP), epigallocatechin gallate, KYT-1 (Arg-gingipain inhibitor), and KYT-36 (Lys-gingipain inhibitor). Plasma supernatants from wild-type and fimbria-mutant cultures markedly stimulated cellular proliferation, whereas those containing gingipain-null mutants showed negligible effects. SMC proliferation was also induced by plasma treated with trypsin. Furthermore, plasma supernatants cultured in the presence of KYT-1/KYT-36 and AP showed significant inhibitory effects on SMC proliferation, whereas cultures with epigallocatechin gallate did not. Our results suggest that Pg gingipains are involved in the induction of SMC transformation and proliferation, whereas this was inhibited by AP.

Effects of electrical stimulation on cell proliferation and apoptosis.

PubMed

Love, Maria R; Palee, Siripong; Chattipakorn, Siriporn C; Chattipakorn, Nipon

2018-03-01

The application of exogenous electrical stimulation (ES) to cells in order to manipulate cell apoptosis and proliferation has been widely investigated as a possible method of treatment in a number of diseases. Alteration of the transmembrane potential of cells via ES can affect various intracellular signaling pathways which are involved in the regulation of cellular function. Controversially, several types of ES have proved to be effective in both inhibiting or inducing apoptosis, as well as increasing proliferation. However, the mechanisms through which ES achieves this remain fairly unclear. The aim of this review was to comprehensively summarize current findings from in vitro and in vivo studies on the effects of different types of ES on cell apoptosis and proliferation, highlighting the possible mechanisms through which ES induced these effects and define the optimum parameters at which ES can be used. Through this we hope to provide a greater insight into how future studies can most effectively use ES at the clinical trial stage. © 2017 Wiley Periodicals, Inc.

Development of bioengineering system for stem cell proliferation

NASA Astrophysics Data System (ADS)

Park, H. S.; Shah, R.; Shah, C.

2016-08-01

From last decades, intensive research in the field of stem cells proliferation had been promoted due to the unique property of stem cells to self-renew themselves into multiples and has potential to replicate into an organ or tissues and so it's highly demanding though challenging. Bioreactor, a mechanical device, works as a womb for stem cell proliferation by providing nutritious environment for the proper growth of stem cells. Various factors affecting stem cells growth are the bioreactor mechanism, feeding of continuous nutrients, healthy environment, etc., but it always remains a challenge for controlling biological parameters. The present paper unveils the design of mechanical device commonly known as bioreactor in tissues engineering and biotech field, use for proliferation of stem cells and imparts the proper growing condition for stem cells. This high functional bioreactor provides automation mixing of cell culture and stem cells. This design operates in conjunction with mechanism of reciprocating motion. Compare to commercial bioreactors, this proposed design is more convenient, easy to operate and less maintenance is required as bioreactor culture bag is made of polyethylene which is single use purpose. Development of this bioengineering system will be beneficial for better growth and expansion of stem cell

Endogenous Hydrogen Sulfide Enhances Cell Proliferation of Human Gastric Cancer AGS Cells.

PubMed

Sekiguchi, Fumiko; Sekimoto, Teruki; Ogura, Ayaka; Kawabata, Atsufumi

2016-01-01

Hydrogen sulfide (H2S), the third gasotransmitter, is endogenously generated by certain H2S synthesizing enzymes, including cystathionine-γ-lyase (CSE) and cystathionine-β-synthase (CBS) from L-cysteine in the mammalian body. Several studies have shown that endogenous and exogenous H2S affects the proliferation of cancer cells, although the effects of H2S appear to vary with cell type, being either promotive or suppressive. In the present study, we determined whether endogenously formed H2S regulates proliferation in human gastric cancer AGS cells. CSE, but not CBS, was expressed in AGS cells. CSE inhibitors, DL-propargylglycine (PPG) and β-cyano-L-alanine (BCA), significantly suppressed the proliferation of AGS cells in a concentration-dependent manner. CSE inhibitors did not increase lactate dehydrogenase (LDH) release in the same concentration range. The inhibitory effects of PPG and BCA on cell proliferation were reversed by repetitive application of NaHS, a donor of H2S. Interestingly, nuclear condensation and fragmentation were detected in AGS cells treated with PPG or BCA. These results suggest that endogenous H2S produced by CSE may contribute to the proliferation of gastric cancer AGS cells, most probably through anti-apoptotic actions.

CD98 regulates vascular smooth muscle cell proliferation in atherosclerosis.

PubMed

Baumer, Yvonne; McCurdy, Sara; Alcala, Martin; Mehta, Nehal; Lee, Bog-Hieu; Ginsberg, Mark H; Boisvert, William A

2017-01-01

Vascular smooth muscle cells (VSMC) migrate and proliferate to form a stabilizing fibrous cap that encapsulates atherosclerotic plaques. CD98 is a transmembrane protein made of two subunits, CD98 heavy chain (CD98hc) and one of six light chains, and is known to be involved in cell proliferation and survival. Because the influence of CD98hc on atherosclerosis development is unknown, our aim was to determine if CD98hc expressed on VSMC plays a role in shaping the morphology of atherosclerotic plaques by regulating VSMC function. In addition to determining the role of CD98hc in VSMC proliferation and apoptosis, we utilized mice with SMC-specific deletion of CD98hc (CD98hc fl/fl SM22αCre + ) to determine the effects of CD98hc deficiency on VSMC function in atherosclerotic plaque. After culturing for 5 days in vitro, CD98hc -/- VSMC displayed dramatically reduced cell counts, reduced proliferation, as well as reduced migration compared to control VSMC. Analysis of aortic VSCM after 8 weeks of HFD showed a reduction in CD98hc -/- VSMC proliferation as well as increased apoptosis compared to controls. A long-term atherosclerosis study using SMC-CD98hc -/- /ldlr -/- mice was performed. Although total plaque area was unchanged, CD98hc -/- mice showed reduced presence of VSMC within the plaque (2.1 ± 0.4% vs. 4.3 ± 0.4% SM22α-positive area per plaque area, p < 0.05), decreased collagen content, as well as increased necrotic core area (25.8 ± 1.9% vs. 10.9 ± 1.6%, p < 0.05) compared to control ldlr -/- mice. We conclude that CD98hc is required for VSMC proliferation, and that its deficiency leads to significantly reduced presence of VSMC in the neointima. Thus, CD98hc expression in VSMC contributes to the formation of plaques that are morphologically more stable, and thereby protects against atherothrombosis. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Isorhynchophylline protects against pulmonary arterial hypertension and suppresses PASMCs proliferation

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

Guo, Haipeng; Zhang, Xin; Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Health, Qilu Hospital of Shandong University, Jinan 250012

Highlights: • We focus on PASMCs proliferation in the pathogenesis of PAH. • Isorhynchophylline inhibited PASMCs proliferation and alleviated PAH. • IRN blocked PDGF-Rβ phosphorylation and its downstream signal transduction. • IRN regulated cyclins and CDKs to arrest cell cycle in the G0/G1 phase. • We reported IRN has the potential to be a candidate for PAH treatment. - Abstract: Increased pulmonary arterial smooth muscle cells (PASMCs) proliferation is a key pathophysiological component of pulmonary vascular remodeling in pulmonary arterial hypertension (PAH). Isorhynchophylline (IRN) is a tetracyclic oxindole alkaloid isolated from the Chinese herbal medicine Uncaria rhynchophylla. It has longmore » been used clinically for treatment of cardiovascular and cerebrovascular diseases. However, very little is known about whether IRN can influence the development of PAH. Here we examined the effect of IRN on monocrotaline (MCT) induced PAH in rats. Our data demonstrated that IRN prevented MCT induced PAH in rats, as assessed by right ventricular (RV) pressure, the weight ratio of RV to (left ventricular + septum) and RV hypertrophy. IRN significantly attenuated the percentage of fully muscularized small arterioles, the medial wall thickness, and the expression of smooth muscle α-actin (α-SMA) and proliferating cell nuclear antigen (PCNA). In vitro studies, IRN concentration-dependently inhibited the platelet-derived growth factor (PDGF)-BB-induced proliferation of PASMCs. Fluorescence-activated cell-sorting analysis showed that IRN caused G0/G1 phase cell cycle arrest. IRN-induced growth inhibition was associated with downregulation of Cyclin D1 and CDK6 as well as an increase in p27Kip1 levels in PDGF-BB-stimulated PASMCs. Moreover, IRN negatively modulated PDGF-BB-induced phosphorylation of PDGF-Rβ, ERK1/2, Akt/GSK3β, and signal transducers and activators of transcription 3 (STAT3). These results demonstrate that IRN could inhibit PASMCs

Director`s series on proliferation

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

Bailey, K.C.; Price, M.E.

1994-10-17

This series is an occasional publication of essays on the topics of nuclear, chemical, biological, and missile proliferation. Essays contained in this document include: Key issues on NPT renewal and extension, Africa and nuclear nonproliferation, Kenya`s views on the NPT, Prospects for establishing a zone free of weapons of mass destruction in the middle east, effects of a special nuclear weapon materials cut-off convention, and The UK view of NPT renewal.

Russia’s Proliferation Pathways

DTIC Science & Technology

2009-01-01

2002. Russia’s willingness to provide the facilities and related support was also appealing because Moscow did not attach conditions related to human ...much higher level of risk than is already the case. In line with this wholly instrumental or utilitarian approach to the proliferation issue we also...hightened dispute with Georgia. Georgia’s leadership in turn beseeched the U.S. and Europe to stand up for democracy, human rights, and other Western norms

Genetic abolishment of hepatocyte proliferation activates hepatic stem cells.

PubMed

Endo, Yoko; Zhang, Mingjun; Yamaji, Sachie; Cang, Yong

2012-01-01

Quiescent hepatic stem cells (HSCs) can be activated when hepatocyte proliferation is compromised. Chemical injury rodent models have been widely used to study the localization, biomarkers, and signaling pathways in HSCs, but these models usually exhibit severe promiscuous toxicity and fail to distinguish damaged and non-damaged cells. Our goal is to establish new animal models to overcome these limitations, thereby providing new insights into HSC biology and application. We generated mutant mice with constitutive or inducible deletion of Damaged DNA Binding protein 1 (DDB1), an E3 ubiquitin ligase, in hepatocytes. We characterized the molecular mechanism underlying the compensatory activation and the properties of oval cells (OCs) by methods of mouse genetics, immuno-staining, cell transplantation and gene expression profiling. We show that deletion of DDB1 abolishes self-renewal capacity of mouse hepatocytes in vivo, leading to compensatory activation and proliferation of DDB1-expressing OCs. Partially restoring proliferation of DDB1-deficient hepatocytes by ablation of p21, a substrate of DDB1 E3 ligase, alleviates OC proliferation. Purified OCs express both hepatocyte and cholangiocyte markers, form colonies in vitro, and differentiate to hepatocytes after transplantation. Importantly, the DDB1 mutant mice exhibit very minor liver damage, compared to a chemical injury model. Microarray analysis reveals several previously unrecognized markers, including Reelin, enriched in oval cells. Here we report a genetic model in which irreversible inhibition of hepatocyte duplication results in HSC-driven liver regeneration. The DDB1 mutant mice can be broadly applied to studies of HSC differentiation, HSC niche and HSCs as origin of liver cancer.

Oxytocin stimulates cell proliferation in vaginal cell line Vk2E6E7.

PubMed

Kallak, Theodora K; Uvnäs-Moberg, Kerstin

2017-03-01

Objective During and after menopause, the symptoms of vaginal atrophy cause great discomfort and necessitate effective treatment options. Currently, vaginally applied oxytocin is being investigated as a treatment for the symptoms of vaginal atrophy in postmenopausal women. To clarify the mechanisms behind oxytocins effects on vaginal atrophy, the present study investigated the effects of oxytocin on cell proliferation in the cells of the Vk2E6E7 line, a non-tumour vaginal cell line. The study also compared the effects of oxytocin with those of estradiol (E2). Study design The effects of both oxytocin and E2 on the proliferation of Vk2E6E7 cells were investigated using Cell Proliferation ELISA BrdU Colorimetric Assay. The expression of both oxytocin and oxytocin receptor was studied in Vk2E6E7 cells using quantitative real-time polymerase chain reaction and immunofluorescent staining. Main outcome measures Cell proliferation and gene expression. Results Oxytocin increased cell proliferation both time dependently and dose dependently. This differed from the effect pattern observed in cells treated with E2. In addition, in oxytocin-treated cells, the oxytocin receptor was found to be co-localized with caveolin-1, indicating pro-proliferative signalling within the cell. Conclusions Oxytocin stimulates cell proliferation and the co-localization of oxytocin receptor with caveolin-1 in oxytocin-treated cells, supporting the role of oxytocin signalling in cell proliferation. In addition, these findings suggest that increased cell proliferation is one mechanism by which local vaginal oxytocin treatment increases vaginal thickness and relieves vaginal symptoms in postmenopausal women with vaginal atrophy.

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

Deterring Nuclear Proliferation: The Importance of IAEA Safeguards: A TEXTBOOK

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

Rosenthal, M.D.; Fishbone, L.G.; Gallini, L.

2012-03-13

Nuclear terrorism and nuclear proliferation are among the most pressing challenges to international peace and security that we face today. Iran and Syria remain in non-compliance with the safeguards requirements of the NPT, and the nuclear ambitions of North Korea remain unchecked. Despite these challenges, the NPT remains a cornerstone of the nuclear non-proliferation regime, and the safeguards implemented by the International Atomic Energy Agency (IAEA) under the NPT play a critical role in deterring nuclear proliferation.How do they work? Where did they come from? And what is their future? This book answers these questions. Anyone studying the field ofmore » nuclear non-proliferation will benefit from reading this book, and for anyone entering the field, the book will enable them to get a running start. Part I describes the foundations of the international safeguards system: its origins in the 1930s - when new discoveries in physics made it clear immediately that nuclear energy held both peril and promise - through the entry into force in 1970 of the NPT, which codified the role of IAEA safeguards as a means to verify states NPT commitments not to acquire nuclear weapons. Part II describes the NPT safeguards system, which is based on a model safeguards agreement developed specifically for the NPT, The Structure and Content of Agreements between the Agency and States required in connection with the Treaty on the Non-Proliferation of Nuclear Weapons, which has been published by the IAEA as INFCIRC/153. Part III describes events, especially in South Africa, the DPRK, and Iraq in the early 1990s, that triggered a transformation in the way in which safeguards were conceptualized and implemented.« less

Endotoxin Contamination of Apolipoprotein A-I: Effect on Macrophage Proliferation – A Cautionary Tale

PubMed Central

Jin, Xueting; Xu, Qing; Champion, Keith; Kruth, Howard S.

2015-01-01

This technical report addresses the problem of endotoxin contamination of apolipoprotein reagents. Using a bromodeoxyuridine incorporation cell proliferation assay, we observed that human plasma ApoA-I as low as 1 μg/ml resulted in a >90% inhibition in macrophage proliferation. However, not all ApoA-I from different sources showed this effect. We considered the possibility that endotoxin contamination of the apolipoproteins contributed to the differential inhibition of macrophage cell proliferation. Endotoxin alone very potently inhibited macrophage proliferation (0.1 ng/ml inhibited macrophage proliferation >90%). Measurement of endotoxin levels in the apolipoprotein products, including an analysis of free versus total endotoxin, the latter which included endotoxin that was masked due to binding to protein, suggested that free endotoxin mediated inhibition of macrophage proliferation. Despite the use of an advanced endotoxin removal procedure and agents commonly used to inhibit endotoxin action, the potency of endotoxin precluded successful elimination of endotoxin effect. Our findings show that endotoxin contamination can significantly influence apparent apolipoprotein-mediated cell effects (or effects of any other biological products), especially when these products are tested on highly endotoxin-sensitive cells, such as macrophages. PMID:25778625

Peroxisome proliferator-activated receptor gamma coactivator-1 alpha acts as a tumor suppressor in hepatocellular carcinoma.

PubMed

Liu, Rui; Zhang, Haiyang; Zhang, Yan; Li, Shuang; Wang, Xinyi; Wang, Xia; Wang, Cheng; Liu, Bin; Zen, Ke; Zhang, Chen-Yu; Zhang, Chunni; Ba, Yi

2017-04-01

Peroxisome proliferator-activated receptor gamma coactivator-1 alpha plays a crucial role in regulating the biosynthesis of mitochondria, which is closely linked to the energy metabolism in various tumors. This study investigated the regulatory role of peroxisome proliferator-activated receptor gamma coactivator-1 alpha in the pathogenesis of hepatocellular carcinoma. In this study, the changes of peroxisome proliferator-activated receptor gamma coactivator-1 alpha messenger RNA levels between normal human liver and hepatocellular carcinoma tissue were examined by quantitative reverse transcription polymerase chain reaction. Knockdown of peroxisome proliferator-activated receptor gamma coactivator-1 alpha was conducted by RNA interference in the human liver cell line L02, while overexpression of peroxisome proliferator-activated receptor gamma coactivator-1 alpha was conducted by adenovirus encoding peroxisome proliferator-activated receptor gamma coactivator-1 alpha complementary DNA in the human hepatocarcinoma cell line HepG2. Cellular morphological changes were observed via optical and electron microscopy. Cellular apoptosis was determined by Hoechst 33258 staining. In addition, the expression levels of 21,400 genes in tissues and cells were detected by microarray. It was shown that peroxisome proliferator-activated receptor gamma coactivator-1 alpha expression was significantly downregulated in hepatocellular carcinoma compared with normal liver tissues. After knockdown of peroxisome proliferator-activated receptor gamma coactivator-1 alpha expression in L02 cells, cells reverted to immature and dedifferentiated morphology exhibiting cancerous tendency. Apoptosis occurred in the HepG2 cells after transfection by adenovirus encoding peroxisome proliferator-activated receptor gamma coactivator-1 alpha. Microarray analysis showed consistent results. The results suggest that peroxisome proliferator-activated receptor gamma coactivator-1 alpha acts as a tumor

Profound Tissue Specificity in Proliferation Control Underlies Cancer Drivers and Aneuploidy Patterns.

PubMed

Sack, Laura Magill; Davoli, Teresa; Li, Mamie Z; Li, Yuyang; Xu, Qikai; Naxerova, Kamila; Wooten, Eric C; Bernardi, Ronald J; Martin, Timothy D; Chen, Ting; Leng, Yumei; Liang, Anthony C; Scorsone, Kathleen A; Westbrook, Thomas F; Wong, Kwok-Kin; Elledge, Stephen J

2018-04-05

Genomics has provided a detailed structural description of the cancer genome. Identifying oncogenic drivers that work primarily through dosage changes is a current challenge. Unrestrained proliferation is a critical hallmark of cancer. We constructed modular, barcoded libraries of human open reading frames (ORFs) and performed screens for proliferation regulators in multiple cell types. Approximately 10% of genes regulate proliferation, with most performing in an unexpectedly highly tissue-specific manner. Proliferation drivers in a given cell type showed specific enrichment in somatic copy number changes (SCNAs) from cognate tumors and helped predict aneuploidy patterns in those tumors, implying that tissue-type-specific genetic network architectures underlie SCNA and driver selection in different cancers. In vivo screening confirmed these results. We report a substantial contribution to the catalog of SCNA-associated cancer drivers, identifying 147 amplified and 107 deleted genes as potential drivers, and derive insights about the genetic network architecture of aneuploidy in tumors. Copyright © 2018 Elsevier Inc. All rights reserved.

Isolation of hydrocarbon-degrading extremely halophilic archaea from an uncontaminated hypersaline pond (Camargue, France).

PubMed

Tapilatu, Yosmina H; Grossi, Vincent; Acquaviva, Monique; Militon, Cécile; Bertrand, Jean-Claude; Cuny, Philippe

2010-03-01

Little information exists about the ability of halophilic archaea present in hypersaline environments to degrade hydrocarbons. In order to identify the potential actors of hydrocarbon degradation in these environments, enrichment cultures were prepared using samples collected from a shallow crystallizer pond with no known contamination history in Camargue, France, with n-alkanes provided as source of carbon and energy. Five alkane-degrading halophilic archaeal strains were isolated: one (strain MSNC 2) was closely related to Haloarcula and three (strains MSNC 4, MSNC 14, and MSNC 16) to Haloferax. Biodegradation assays showed that depending on the strain, 32 to 95% (0.5 g/l) of heptadecane was degraded after 30 days of incubation at 40 degrees C in 225 g/l NaCl artificial medium. One of the strains (MSNC 14) was also able to degrade phenanthrene. This work clearly shows for the first time the potential role of halophilic archaea belonging to the genera Haloarcula and Haloferax in the degradation of hydrocarbons in both pristine and hydrocarbon-contaminated hypersaline environments.

Dracorhodin perchlorate regulates fibroblast proliferation to promote rat's wound healing.

PubMed

Jiang, Xiaowen; Liu, Lin; Qiao, Lu; Zhang, Binqing; Wang, Xuewei; Han, Yuwen; Yu, Wenhui

2018-02-01

In recent years, plant-derived extracts are increasing interest from researchers worldwide due to good efficacy and lower side effects. Among the different plant extracts, Dracorhodin perchlorate (DP) is originated from Dragon's blood which has long been used as a natural medicine with various pharmacological activities. In the present study, we have explored the potential regulation of DP on fibroblast proliferation which promotes wound healing both in vitro and in vivo. DP at treatment of 12-24 h significantly induced fibroblast proliferation which is associated with increasing level of phosphorylated-extracellular signal-regulated kinase (ERK). Moreover, if ERK is halted with siRNA, DP cannot induce fibroblast proliferation. In vivo, DP ointment treatment at low- (2.5 μg/mL), medium- (5 μg/mL) and high-(10 μg/mL) doses, rat wounds healed more rapidly compared with the control group. After DP treatment for 7 days, Serpin family H member 1 (SERPINH1) staining confirmed enhanced fibroblast proliferation in the wound tissue. Finally, phosphorylated-ERK in the wound tissue remarkably increased with DP ointment treatment. Therefore, DP may be developed into a potential lead compounds for the treatment of wounds in clinical trials in the near future. Copyright © 2018 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

Strategic forum. Number 70. Regional deterrence strategies for new proliferation threats

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

Kahan, J.H.

1996-04-01

The deterrence of armed aggression against the United States, its vital national interests, or its allies has moved beyond the requirements of conventional force deterrence. The proliferation of nuclear, biological, and chemical (NBC) weapons requires a new strategy to ensure effective deterrence against their use by regional states that could not win in a conventional conflict with the United States. Because proliferation has expanded to a number of regional actors, a single strategy is unlikely to be sufficient in deterring states with varied motivations, and social, economic, religious, cultural, and political backgrounds. The Unified Commands-principally the Pacific, Central and Europeanmore » Commands- provide a ready-made framework in which general U.S. deterrence strategies can be tailored to each proliferant state While the Unified Commands would shape the individual deterrence strategies, the national command authority (NCA) would retain control of key decisions. Guidelines for NBC regional deterrence should include developing credible counterproliferation postures, profiling potential adversaries, tailoring our military capabilities to specific threats, integrating NBC preparedness into exercises and warplans, and actively pursuing coalitions designed to deter regional proliferators from threatening to use or using NBC weapons.« less

Cyclin D2 induces proliferation of cardiac myocytes and represses hypertrophy

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

Busk, Peter K.; Hinrichsen, Rebecca; Bartkova, Jirina

2005-03-10

The myocytes of the adult mammalian heart are considered unable to divide. Instead, mitogens induce cardiomyocyte hypertrophy. We have investigated the effect of adenoviral overexpression of cyclin D2 on myocyte proliferation and morphology. Cardiomyocytes in culture were identified by established markers. Cyclin D2 induced DNA synthesis and proliferation of cardiomyocytes and impaired hypertrophy induced by angiotensin II and serum. At the molecular level, cyclin D2 activated CDK4/6 and lead to pRB phosphorylation and downregulation of the cell cycle inhibitors p21{sup Waf1/Cip1} and p27{sup Kip1}. Expression of the CDK4/6 inhibitor p16 inhibited proliferation and cyclin D2 overexpressing myocytes became hypertrophic undermore » such conditions. Inhibition of hypertrophy by cyclin D2 correlated with downregulation of p27{sup Kip1}. These data show that hypertrophy and proliferation are highly related processes and suggest that cardiomyocyte hypertrophy is due to low amounts of cell cycle activators unable to overcome the block imposed by cell cycle inhibitors. Cell cycle entry upon hypertrophy may be converted to cell division by increased expression of activators such as cyclin D2.« less

Nuclear Proliferation in the Middle East: In Pursuit of a Regional Logic

DTIC Science & Technology

the Cold War allowed the sole superpower, the United States, to better manage proliferation issues and strengthen existing or create new multilateral...mechanisms to control these threats. In the recent, less structured multipolar environment, great powers came together to manage proliferation with their efforts bolstered by the nonproliferation regime.

H{sub 2}S does not regulate proliferation via T-type Ca{sup 2+} channels

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

Elies, Jacobo; Johnson, Emily; Boyle, John P.

T-type Ca{sup 2+} channels (Cav3.1, 3.2 and 3.3) strongly influence proliferation of various cell types, including vascular smooth muscle cells (VSMCs) and certain cancers. We have recently shown that the gasotransmitter carbon monoxide (CO) inhibits T-type Ca{sup 2+} channels and, in so doing, attenuates proliferation of VSMC. We have also shown that the T-type Ca{sup 2+} channel Cav3.2 is selectively inhibited by hydrogen sulfide (H{sub 2}S) whilst the other channel isoforms (Cav3.1 and Cav3.3) are unaffected. Here, we explored whether inhibition of Cav3.2 by H{sub 2}S could account for the anti-proliferative effects of this gasotransmitter. H{sub 2}S suppressed proliferation inmore » HEK293 cells expressing Cav3.2, as predicted by our previous observations. However, H{sub 2}S was similarly effective in suppressing proliferation in wild type (non-transfected) HEK293 cells and those expressing the H{sub 2}S insensitive channel, Cav3.1. Further studies demonstrated that T-type Ca{sup 2+} channels in the smooth muscle cell line A7r5 and in human coronary VSMCs strongly influenced proliferation. In both cell types, H{sub 2}S caused a concentration-dependent inhibition of proliferation, yet by far the dominant T-type Ca{sup 2+} channel isoform was the H{sub 2}S-insensitive channel, Cav3.1. Our data indicate that inhibition of T-type Ca{sup 2+} channel-mediated proliferation by H{sub 2}S is independent of the channels’ sensitivity to H{sub 2}S. - Highlights: • T-type Ca{sup 2+} channels regulate proliferation and are sensitive to the gasotransmitters CO and H{sub 2}S. • H{sub 2}S reduced proliferation in HEK293 cells expressing the H{sub 2}S sensitive Cav3.2 channel. • H{sub 2}S also inhibited proliferation in non-transfected cells and HEK293 cells expressing Cav3.1. • Native smooth muscle cells primarily express Cav3.1. Their proliferation was also inhibited by H{sub 2}S. • Unlike CO, H{sub 2}S does not regulate smooth muscle proliferation via T-type Ca

Effect of mobile phone proliferation on crash notification times and fatality rates.

PubMed

Stickles, Jimmy L; Kempema, James M; Brown, Lawrence H

2018-01-01

The purpose of this study was to evaluate whether increased proliferation of mobile telephones has been associated with decreased MVC notification times and/or decreased MVC fatality rates in the United States (US). We used World Bank annual mobile phone market penetration data and US Fatality Analysis Reporting System (FARS) fatal MVC data for 1994-2014. For each year, phone proliferation was measured as mobile phones per 100 population. FARS data were used to calculate MVC notification time (time EMS notified - time MVC occurred) in minutes, and to determine the MVC fatality rate per billion vehicle miles traveled (BVMT). We used basic vector auto-regression modeling to explore relationships between changes in phone proliferation and subsequent changes in median and 90th percentile MVC notification times, as well as MVC fatality rates. From 1994 to 2014, larger year-over-year increases in phone proliferation were associated with larger decreases in 90th percentile notification times for MVCs occurring during daylight hours (p=0.004) and on the national highway system (p=0.046) two years subsequent, and crashes off the national highway system three years subsequent (p=0.023). There were no significant associations between changes in phone proliferation and subsequent changes in median crash notification times, nor with subsequent changes in MVC fatality rates. Between 1994 and 2014 increased mobile phone proliferation in the U.S. was associated with shorter 90th percentile EMS notification times for some subgroups of fatal MVCs, but not with decreases in median notification times or overall MVC fatality rates. Copyright © 2017 Elsevier Inc. All rights reserved.

Uterine epithelial cell proliferation and endometrial hyperplasia: evidence from a mouse model.

PubMed

Gao, Yang; Li, Shu; Li, Qinglei

2014-08-01

In the uterus, epithelial cell proliferation changes during the estrous cycle and pregnancy. Uncontrolled epithelial cell proliferation results in implantation failure and/or cancer development. Transforming growth factor-β (TGF-β) signaling is a fundamental regulator of diverse biological processes and is indispensable for multiple reproductive functions. However, the in vivo role of TGF-β signaling in uterine epithelial cells remains poorly defined. We have shown that in the uterus, conditional deletion of the Type 1 receptor for TGF-β (Tgfbr1) using anti-Müllerian hormone receptor type 2 (Amhr2) Cre leads to myometrial defects. Here, we describe enhanced epithelial cell proliferation by immunostaining of Ki67 in the uteri of these mice. The aberration culminated in endometrial hyperplasia in aged females. To exclude the potential influence of ovarian steroid hormones, the proliferative status of uterine epithelial cells was assessed following ovariectomy. Increased uterine epithelial cell proliferation was also revealed in ovariectomized Tgfbr1 Amhr2-Cre conditional knockout mice. We further demonstrated that transcript levels for fibroblast growth factor 10 (Fgf10) were markedly up-regulated in Tgfbr1 Amhr2-Cre conditional knockout uteri. Consistently, treatment of primary uterine stromal cells with TGF-β1 significantly reduced Fgf10 mRNA expression. Thus, our findings suggest a potential involvement of TGFBR1-mediated signaling in the regulation of uterine epithelial cell proliferation, and provide genetic evidence supporting the role of uterine epithelial cell proliferation in the pathogenesis of endometrial hyperplasia. © The Author 2014. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Eroding market stability by proliferation of financial instruments

NASA Astrophysics Data System (ADS)

Caccioli, F.; Marsili, M.; Vivo, P.

2009-10-01

We contrast Arbitrage Pricing Theory (APT), the theoretical basis for the development of financial instruments, with a dynamical picture of an interacting market, in a simple setting. The proliferation of financial instruments apparently provides more means for risk diversification, making the market more efficient and complete. In the simple market of interacting traders discussed here, the proliferation of financial instruments erodes systemic stability and it drives the market to a critical state characterized by large susceptibility, strong fluctuations and enhanced correlations among risks. This suggests that the hypothesis of APT may not be compatible with a stable market dynamics. In this perspective, market stability acquires the properties of a common good, which suggests that appropriate measures should be introduced in derivative markets, to preserve stability. in here

A Neural Network Based Workstation for Automated Cell Proliferation Analysis

DTIC Science & Technology

2001-10-25

work was supported by the Programa de Apoyo a Proyectos de Desarrollo e Investigacíon en Informática REDII 2000. We thank Blanca Itzel Taboada for...Meléndez1, G. Corkidi.2 1Centro de Instrumentos, UNAM. P.O. Box 70-186, México 04510, D.F. 2Instituto de Biotecnología, UNAM. P.O. Box 510-3, 62250...proliferation analysis, of cytological microscope images. The software of the system assists the expert biotechnologist during cell proliferation and

Inflammation-Induced Cell Proliferation Potentiates DNA Damage-Induced Mutations In Vivo

PubMed Central

Kiraly, Orsolya; Gong, Guanyu; Olipitz, Werner; Muthupalani, Sureshkumar; Engelward, Bevin P.

2015-01-01

Mutations are a critical driver of cancer initiation. While extensive studies have focused on exposure-induced mutations, few studies have explored the importance of tissue physiology as a modulator of mutation susceptibility in vivo. Of particular interest is inflammation, a known cancer risk factor relevant to chronic inflammatory diseases and pathogen-induced inflammation. Here, we used the fluorescent yellow direct repeat (FYDR) mice that harbor a reporter to detect misalignments during homologous recombination (HR), an important class of mutations. FYDR mice were exposed to cerulein, a potent inducer of pancreatic inflammation. We show that inflammation induces DSBs (γH2AX foci) and that several days later there is an increase in cell proliferation. While isolated bouts of inflammation did not induce HR, overlap between inflammation-induced DNA damage and inflammation-induced cell proliferation induced HR significantly. To study exogenously-induced DNA damage, animals were exposed to methylnitrosourea, a model alkylating agent that creates DNA lesions relevant to both environmental exposures and cancer chemotherapy. We found that exposure to alkylation damage induces HR, and importantly, that inflammation-induced cell proliferation and alkylation induce HR in a synergistic fashion. Taken together, these results show that, during an acute bout of inflammation, there is a kinetic barrier separating DNA damage from cell proliferation that protects against mutations, and that inflammation-induced cell proliferation greatly potentiates exposure-induced mutations. These studies demonstrate a fundamental mechanism by which inflammation can act synergistically with DNA damage to induce mutations that drive cancer and cancer recurrence. PMID:25647331

Comparison of the circadian variation in cell proliferation in normal and neoplastic colonic epithelial cells.

PubMed

Kennedy, M F; Tutton, P J; Barkla, D H

1985-09-15

Circadian variations in cell proliferation in normal tissues have been recognised for many years but comparable phenomena in neoplastic tissues appear not to have been reported. Adenomas and carcinomas were induced in mouse colon by injection of dimethylhydrazine (DMH) and cell proliferation in these tumors was measured stathmokinetically. In normal intestine cell proliferation is fastest at night whereas in both adenomas and carcinomas it was found to be slower at night than in the middle of the day. Chemical sympathectomy was found to abolish the circadian variation in tumor cell proliferation.

CRMP2 Phosphorylation Drives Glioblastoma Cell Proliferation.

PubMed

Moutal, Aubin; Villa, Lex Salas; Yeon, Seul Ki; Householder, Kyle T; Park, Ki Duk; Sirianni, Rachael W; Khanna, Rajesh

2018-05-01

Glioblastoma (GBM) is an aggressive primary brain tumor. The rapid growth and the privileged provenance of the tumor within the brain contribute to its aggressivity and poor therapeutic targeting. A poor prognostic factor in glioblastoma is the deletion or mutation of the Nf1 gene. This gene codes for the protein neurofibromin, a tumor suppressor gene that is known to interact with the collapsin response mediator protein 2 (CRMP2). CRMP2 expression and elevated expression of nuclear phosphorylated CRMP2 have recently been implicated in cancer progression. The CRMP2-neurofibromin interaction protects CRMP2 from its phosphorylation by cyclin-dependent kinase 5 (Cdk5), an event linked to cancer progression. In three human glioblastoma cell lines (GL15, A172, and U87), we observed an inverse correlation between neurofibromin expression and CRMP2 phosphorylation levels. Glioblastoma cell proliferation was dependent on CRMP2 expression and phosphorylation by Cdk5 and glycogen synthase kinase 3 beta (GSK3β). The CRMP2 phosphorylation inhibitor (S)-lacosamide reduces, in a concentration-dependent manner, glioblastoma cell proliferation and induced apoptosis in all three GBM cell lines tested. Since (S)-lacosamide is bioavailable in the brain, we tested its utility in an in vivo orthotopic model of GBM using GL261-LucNeo glioma cells. (S)-lacosamide decreased tumor size, as measured via in vivo bioluminescence imaging, by ~54% compared to vehicle control. Our results introduce CRMP2 expression and phosphorylation as a novel player in GBM proliferation and survival, which is enhanced by loss of Nf1.

Tumor proliferation and diffusion on percolation clusters.

PubMed

Jiang, Chongming; Cui, Chunyan; Zhong, Weirong; Li, Gang; Li, Li; Shao, Yuanzhi

2016-10-01

We study in silico the influence of host tissue inhomogeneity on tumor cell proliferation and diffusion by simulating the mobility of a tumor on percolation clusters with different homogeneities of surrounding tissues. The proliferation and diffusion of a tumor in an inhomogeneous tissue could be characterized in the framework of the percolation theory, which displays similar thresholds (0.54, 0.44, and 0.37, respectively) for tumor proliferation and diffusion in three kinds of lattices with 4, 6, and 8 connecting near neighbors. Our study reveals the existence of a critical transition concerning the survival and diffusion of tumor cells with leaping metastatic diffusion movement in the host tissues. Tumor cells usually flow in the direction of greater pressure variation during their diffusing and infiltrating to a further location in the host tissue. Some specific sites suitable for tumor invasion were observed on the percolation cluster and around these specific sites a tumor can develop into scattered tumors linked by some advantage tunnels that facilitate tumor invasion. We also investigate the manner that tissue inhomogeneity surrounding a tumor may influence the velocity of tumor diffusion and invasion. Our simulation suggested that invasion of a tumor is controlled by the homogeneity of the tumor microenvironment, which is basically consistent with the experimental report by Riching et al. as well as our clinical observation of medical imaging. Both simulation and clinical observation proved that tumor diffusion and invasion into the surrounding host tissue is positively correlated with the homogeneity of the tissue.

Bone morphogenetic protein-4 strongly potentiates growth factor-induced proliferation of mammary epithelial cells

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

Montesano, Roberto; Sarkoezi, Rita; Schramek, Herbert

2008-09-12

Bone morphogenetic proteins (BMPs) are multifunctional cytokines that elicit pleiotropic effects on biological processes such as cell proliferation, cell differentiation and tissue morphogenesis. With respect to cell proliferation, BMPs can exert either mitogenic or anti-mitogenic activities, depending on the target cells and their context. Here, we report that in low-density cultures of immortalized mammary epithelial cells, BMP-4 did not stimulate cell proliferation by itself. However, when added in combination with suboptimal concentrations of fibroblast growth factor (FGF)-2, FGF-7, FGF-10, epidermal growth factor (EGF) or hepatocyte growth factor (HGF), BMP-4 potently enhanced growth factor-induced cell proliferation. These results reveal a hithertomore » unsuspected interplay between BMP-4 and growth factors in the regulation of mammary epithelial cell proliferation. We suggest that the ability of BMP-4 to potentiate the mitogenic activity of multiple growth factors may contribute to mammary gland ductal morphogenesis as well as to breast cancer progression.« less

Proliferation zones in the axolotl brain and regeneration of the telencephalon

PubMed Central

2013-01-01

Background Although the brains of lower vertebrates are known to exhibit somewhat limited regeneration after incisional or stab wounds, the Urodele brain exhibits extensive regeneration after massive tissue removal. Discovering whether and how neural progenitor cells that reside in the ventricular zones of Urodeles proliferate to mediate tissue repair in response to injury may produce novel leads for regenerative strategies. Here we show that endogenous neural progenitor cells resident to the ventricular zone of Urodeles spontaneously proliferate, producing progeny that migrate throughout the telencephalon before terminally differentiating into neurons. These progenitor cells appear to be responsible for telencephalon regeneration after tissue removal and their activity may be up-regulated by injury through an olfactory cue. Results There is extensive proliferation of endogenous neural progenitor cells throughout the ventricular zone of the adult axolotl brain. The highest levels are observed in the telencephalon, especially the dorsolateral aspect, and cerebellum. Lower levels are observed in the mesencephalon and rhombencephalon. New cells produced in the ventricular zone migrate laterally, dorsally and ventrally into the surrounding neuronal layer. After migrating from the ventricular zone, the new cells primarily express markers of neuronal differentiative fates. Large-scale telencephalic tissue removal stimulates progenitor cell proliferation in the ventricular zone of the damaged region, followed by proliferation in the tissue that surrounds the healing edges of the wound until the telencephalon has completed regeneration. The proliferative stimulus appears to reside in the olfactory system, because telencephalic regeneration does not occur in the brains of olfactory bulbectomized animals in which the damaged neural tissue simply heals over. Conclusion There is a continual generation of neuronal cells from neural progenitor cells located within the

41 CFR 109-45.309-53 - Nuclear-related or proliferation sensitive property.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 41 Public Contracts and Property Management 3 2014-01-01 2014-01-01 false Nuclear-related or proliferation sensitive property. 109-45.309-53 Section 109-45.309-53 Public Contracts and Property Management... Personal Property § 109-45.309-53 Nuclear-related or proliferation sensitive property. Nuclear-related or...

41 CFR 109-45.309-53 - Nuclear-related or proliferation sensitive property.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 41 Public Contracts and Property Management 3 2011-01-01 2011-01-01 false Nuclear-related or proliferation sensitive property. 109-45.309-53 Section 109-45.309-53 Public Contracts and Property Management... Personal Property § 109-45.309-53 Nuclear-related or proliferation sensitive property. Nuclear-related or...

41 CFR 109-45.309-53 - Nuclear-related or proliferation sensitive property.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 41 Public Contracts and Property Management 3 2013-07-01 2013-07-01 false Nuclear-related or proliferation sensitive property. 109-45.309-53 Section 109-45.309-53 Public Contracts and Property Management... Personal Property § 109-45.309-53 Nuclear-related or proliferation sensitive property. Nuclear-related or...

41 CFR 109-45.309-53 - Nuclear-related or proliferation sensitive property.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 41 Public Contracts and Property Management 3 2012-01-01 2012-01-01 false Nuclear-related or proliferation sensitive property. 109-45.309-53 Section 109-45.309-53 Public Contracts and Property Management... Personal Property § 109-45.309-53 Nuclear-related or proliferation sensitive property. Nuclear-related or...

41 CFR 109-45.309-53 - Nuclear-related or proliferation sensitive property.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false Nuclear-related or proliferation sensitive property. 109-45.309-53 Section 109-45.309-53 Public Contracts and Property Management... Personal Property § 109-45.309-53 Nuclear-related or proliferation sensitive property. Nuclear-related or...

PDGF is Required for Remyelination-Promoting IgM Stimulation of Oligodendrocyte Progenitor Cell Proliferation

PubMed Central

Watzlawik, Jens O.; Warrington, Arthur E.; Rodriguez, Moses

2013-01-01

Background Promotion of remyelination is a major goal in treating demyelinating diseases such as multiple sclerosis (MS). The recombinant human monoclonal IgM, rHIgM22, targets myelin and oligodendrocytes (OLs) and promotes remyelination in animal models of MS. It is unclear whether rHIgM22-mediated stimulation of lesion repair is due to promotion of oligodendrocyte progenitor cell (OPC) proliferation and survival, OPC differentiation into myelinating OLs or protection of mature OLs. It is also unknown whether astrocytes or microglia play a functional role in IgM-mediated lesion repair. Methods We assessed the effect of rHIgM22 on cell proliferation in mixed CNS glial and OPC cultures by tritiated-thymidine uptake and by double-label immunocytochemistry using the proliferation marker, Ki-67. Antibody-mediated signaling events, OPC differentiation and OPC survival were investigated and quantified by Western blots. Results rHIgM22 stimulates OPC proliferation in mixed glial cultures but not in purified OPCs. There is no proliferative response in astrocytes or microglia. rHIgM22 activates PDGFαR in OPCs in mixed glial cultures. Blocking PDGFR-kinase inhibits rHIgM22-mediated OPC proliferation in mixed glia. We confirm in isolated OPCs that rHIgM22-mediated anti-apoptotic signaling and inhibition of OPC differentiation requires PDGF and FGF-2. We observed no IgM-mediated effect in mature OLs in the absence of PDGF and FGF-2. Conclusion Stimulation of OPC proliferation by rHIgM22 depends on co-stimulatory astrocytic and/or microglial factors. We demonstrate that rHIgM22-mediated activation of PDGFαR is required for stimulation of OPC proliferation. We propose that rHIgM22 lowers the PDGF threshold required for OPC proliferation and protection, which can result in remyelination of CNS lesions. PMID:23383310

WINGLESS (WNT) signaling is a progesterone target for rat uterine stromal cell proliferation

PubMed Central

Talbott, Alex; Bhusri, Anuradha; Krumsick, Zach; Foster, Sierra; Wormington, Joshua; Kimler, Bruce F

2016-01-01

Preparation of mammalian uterus for embryo implantation requires a precise sequence of cell proliferation. In rodent uterus, estradiol stimulates proliferation of epithelial cells. Progesterone operates as a molecular switch and redirects proliferation to the stroma by down-regulating glycogen synthase kinase-3β (GSK-3β) and stimulating β-catenin accumulation in the periluminal stromal cells. In this study, the WNT signal involved in the progesterone-dependent proliferative switch was investigated. Transcripts of four candidate Wnt genes were measured in the uteri from ovariectomized (OVX) rats, progesterone-pretreated (3 days of progesterone, 2mg/daily) rats, and progesterone-pretreated rats given a single dose (0.2µg) of estradiol. The spatial distribution of the WNT proteins was determined in the uteri after the same treatments. Wnt5a increased in response to progesterone and the protein emerged in the periluminal stromal cells of progesterone-pretreated rat uteri. To investigate whether WNT5A was required for proliferation, uterine stromal cell lines were stimulated with progesterone (1µM) and fibroblast growth factor (FGF, 50ng/mL). Proliferating stromal cells expressed a two-fold increase in WNT5A protein at 12h post stimulation. Stimulated stromal cells were cultured with actinomycin D (25µg/mL) to inhibit new RNA synthesis. Relative Wnt5a expression increased at 4 and 6 h of culture, suggesting that progesterone plus FGF preferentially increased Wnt5a mRNA stability. Knockdown of Wnt5a in uterine stromal cell lines inhibited stromal cell proliferation and decreased Wnt5a mRNA. The results indicate that progesterone initiates and synchronizes uterine stromal cell proliferation by increasing WNT5A expression and signaling. PMID:26975616

The Molecular Phenotype of Endocapillary Proliferation: Novel Therapeutic Targets for IgA Nephropathy

PubMed Central

John, Rohan; Grone, Elisabeth; Porubsky, Stefan; Gröne, Hermann-Josef; Herzenberg, Andrew M.; Scholey, James W.; Hladunewich, Michelle; Cattran, Daniel C.

2014-01-01

IgA nephropathy (IgAN) is a clinically and pathologically heterogeneous disease. Endocapillary proliferation is associated with higher risk of progressive disease, and clinical studies suggest that corticosteroids mitigate this risk. However, corticosteroids are associated with protean cellular effects and significant toxicity. Furthermore the precise mechanism by which they modulate kidney injury in IgAN is not well delineated. To better understand molecular pathways involved in the development of endocapillary proliferation and to identify novel specific therapeutic targets, we evaluated the glomerular transcriptome of microdissected kidney biopsies from 22 patients with IgAN. Endocapillary proliferation was defined according to the Oxford scoring system independently by 3 nephropathologists. We analyzed mRNA expression using microarrays and identified transcripts differentially expressed in patients with endocapillary proliferation compared to IgAN without endocapillary lesions. Next, we employed both transcription factor analysis and in silico drug screening and confirmed that the endocapillary proliferation transcriptome is significantly enriched with pathways that can be impacted by corticosteroids. With this approach we also identified novel therapeutic targets and bioactive small molecules that may be considered for therapeutic trials for the treatment of IgAN, including resveratrol and hydroquinine. In summary, we have defined the distinct molecular profile of a pathologic phenotype associated with progressive renal insufficiency in IgAN. Exploration of the pathways associated with endocapillary proliferation confirms a molecular basis for the clinical effectiveness of corticosteroids in this subgroup of IgAN, and elucidates new therapeutic strategies for IgAN. PMID:25133636

Sprouty2 controls proliferation of palate mesenchymal cells via fibroblast growth factor signaling

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

Matsumura, Kaori; Taketomi, Takaharu, E-mail: taketomi@dent.kyushu-u.ac.jp; Yoshizaki, Keigo

2011-01-28

Research highlights: {yields} Sprouty2-deficient mice exhibit cleft palate as a result of failure of palatal shelf elevation. {yields} We examined palate cell proliferation in Sprouty2-deficient mice. {yields} Palate mesenchymal cell proliferation was increased in Sprouty2 KO mice. {yields} Sprouty2 plays roles in murine palatogenesis by regulating cell proliferation. -- Abstract: Cleft palate is one of the most common craniofacial deformities. The fibroblast growth factor (FGF) plays a central role in reciprocal interactions between adjacent tissues during palatal development, and the FGF signaling pathway has been shown to be inhibited by members of the Sprouty protein family. In this study, wemore » report the incidence of cleft palate, possibly caused by failure of palatal shelf elevation, in Sprouty2-deficient (KO) mice. Sprouty2-deficient palates fused completely in palatal organ culture. However, palate mesenchymal cell proliferation estimated by Ki-67 staining was increased in Sprouty2 KO mice compared with WT mice. Sprouty2-null palates expressed higher levels of FGF target genes, such as Msx1, Etv5, and Ptx1 than WT controls. Furthermore, proliferation and the extracellular signal-regulated kinase (Erk) activation in response to FGF was enhanced in palate mesenchymal cells transfected with Sprouty2 small interfering RNA. These results suggest that Sprouty2 regulates palate mesenchymal cell proliferation via FGF signaling and is involved in palatal shelf elevation.« less

Assessing State Nuclear Weapons Proliferation: Using Bayesian Network Analysis of Social Factors

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

Coles, Garill A.; Brothers, Alan J.; Olson, Jarrod

A Bayesian network (BN) model of social factors can support proliferation assessments by estimating the likelihood that a state will pursue a nuclear weapon. Social factors including political, economic, nuclear capability, security, and national identity and psychology factors may play as important a role in whether a State pursues nuclear weapons as more physical factors. This paper will show how using Bayesian reasoning on a generic case of a would-be proliferator State can be used to combine evidence that supports proliferation assessment. Theories and analysis by political scientists can be leveraged in a quantitative and transparent way to indicate proliferationmore » risk. BN models facilitate diagnosis and inference in a probabilistic environment by using a network of nodes and acyclic directed arcs between the nodes whose connections, or absence of, indicate probabilistic relevance, or independence. We propose a BN model that would use information from both traditional safeguards and the strengthened safeguards associated with the Additional Protocol to indicate countries with a high risk of proliferating nuclear weapons. This model could be used in a variety of applications such a prioritization tool and as a component of state safeguards evaluations. This paper will discuss the benefits of BN reasoning, the development of Pacific Northwest National Laboratory’s (PNNL) BN state proliferation model and how it could be employed as an analytical tool.« less

Induction of endothelial cell proliferation by angiogenic factors released by activated monocytes

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

Pakala, Rajbabu; Watanabe, Takuya; Benedict, Claude R

2002-06-01

Introduction: Cell-cell interaction is an essential component of atherosclerotic plaque development. Activated monocytes appear to play a central role in the development of atherosclerosis, not only through foam cell formation but also via the production of various growth factors that induce proliferation of different cell types that are involved in the plaque development. Using serum free co-culture method, we determined the effect of monocytes on endothelial cell proliferation. Methods: Endothelial cell proliferation is determined by the amount of [{sup 3}H]thymidine incorporated in to the DNA. Basic fibroblast growth factor (b-FGF), vascular endothelial growth factor (VEGF) and interleukin-8 (IL-8) levels inmore » the conditioned medium were determined by ELISA. Results: Conditioned medium from unactivated monocytes partially inhibited endothelial cell proliferation, whereas conditioned medium from activated monocytes promoted endothelial cell proliferation. The mitogenic effect of conditioned medium derived from activated monocytes is due to the presence of b-FGF, VEGF and IL-8. Neutralizing antibodies against b-FGF, VEGF and IL-8 partially reversed the mitogenic effect of conditioned medium derived from activated monocytes. When b-FGF, VEGF and IL-8 were immunoprecipitated from conditioned medium derived from activated monocytes, it is less mitogenic to endothelial cells. Conclusion: Activated monocytes may play an important role in the development of atherosclerotic plaque by producing endothelial cell growth factors.« less

CD147-induced cell proliferation is associated with Smad4 signal inhibition.

PubMed

Qin, Hui; Rasul, Azhar; Li, Xin; Masood, Muqaddas; Yang, Guang; Wang, Na; Wei, Wei; He, Xi; Watanabe, Nobumoto; Li, Jiang; Li, Xiaomeng

2017-09-15

CD147 is a multifunctional trans-membrane glycoprotein, which is highly expressed in many cancers. However, the mechanism by which CD147 modulates cell proliferation is not fully understood. The aim of this study is to investigate the role of CD147 in cell proliferation associated with the TGF-β/Smad4 signaling pathway. Here, we used cell viability and clone formation assays in LNCaP prostate cancer cells to demonstrate that CD147 promotes cell proliferation. The luciferase assay and western blotting show that silencing CD147 using shRNA enhances transcription and expression of p21 WAF1 . Using immunofluorescence and nuclear-cytoplasmic separation, we show that this is primarily attributed to transport of Smad4 from the cytoplasm to nucleus. Other assays (GST pull-down, co-immunoprecipitation and immunofluorescence) demonstrate that Smad4 is a new interaction partner of CD147, with the Smad4 MH2 domain and CD147 intracellular domain (CD147-ICD) being involved in the interaction. Furthermore, we report that a phosphoserine (pSer) in CD147 (pSer252) is responsible for this interaction and inhibition of the Smad4/p21 WAF1 signal that promotes cell proliferation. Our results provide a novel molecular mechanism for CD147-induced cell proliferation associated with Smad4 signal inhibition. Copyright © 2017. Published by Elsevier Inc.

Skeletal muscle Kv7 (KCNQ) channels in myoblast differentiation and proliferation

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

Roura-Ferrer, Meritxell; Sole, Laura; Martinez-Marmol, Ramon

Voltage-dependent K{sup +} channels (Kv) are involved in myocyte proliferation and differentiation by triggering changes in membrane potential and regulating cell volume. Since Kv7 channels may participate in these events, the purpose of this study was to investigate whether skeletal muscle Kv7.1 and Kv7.5 were involved during proliferation and myogenesis. Here we report that, while myotube formation did not regulate Kv7 channels, Kv7.5 was up-regulated during cell cycle progression. Although, Kv7.1 mRNA also increased during the G{sub 1}-phase, pharmacological evidence mainly involves Kv7.5 in myoblast growth. Our results indicate that the cell cycle-dependent expression of Kv7.5 is involved in skeletalmore » muscle cell proliferation.« less

Lactate dehydrogenase-A is indispensable for vascular smooth muscle cell proliferation and migration.

PubMed

Kim, Ji-Hyun; Bae, Kwi-Hyun; Byun, Jun-Kyu; Lee, Sungwoo; Kim, Jung-Guk; Lee, In Kyu; Jung, Gwon-Soo; Lee, You Mie; Park, Keun-Gyu

2017-10-07

The proliferation and migration of vascular smooth muscle cells (VSMCs) have been implicated in the pathogenesis of atherosclerosis. Increased aerobic glycolysis is a key feature of cellular phenotypes including cancer and immune cells. However, the role of aerobic glycolysis in the atherogenic phenotype of VSMCs remains largely unknown. Here, we investigated the role of lactate dehydrogenase-A (LDHA), which is a key enzyme for glycolysis, in the proliferation and migration of VSMCs. Activation of primary rat VSMCs with fetal bovine serum (FBS) or platelet-derived growth factor (PDGF) increased their proliferation and migration, glycolytic activity, and expression of LDHA. Wound healing and transwell migration assays demonstrated that small interfering RNA-mediated knockdown of LDHA and pharmacological inhibition of LDHA by oxamate both effectively inhibited VSMC proliferation and migration. Inhibition of LDHA activity by oxamate reduced PDGF-stimulated glucose uptake, lactate production, and ATP production. Taken together, this study shows that enhanced glycolysis in PDGF- or FBS-stimulated VSMCs plays an important role in their proliferation and migration and suggests that LDHA is a potential therapeutic target to prevent vessel lumen constriction during the course of atherosclerosis and restenosis. Copyright © 2017 Elsevier Inc. All rights reserved.

Repressive effect of the phytoestrogen genistein on estradiol-induced uterine leiomyoma cell proliferation.

PubMed

Miyake, Asako; Takeda, Takashi; Isobe, Aki; Wakabayashi, Atsuko; Nishimoto, Fumihito; Morishige, Ken-Ichirou; Sakata, Masahiro; Kimura, Tadashi

2009-06-01

Uterine leiomyomas are the most common gynecological benign tumor and greatly affect reproductive health and well-being. They are the predominant indication for hysterectomy in premenopausal women. Current epidemiological study reported that soy products intake is inversely associated with diseases leading to hysterectomy. Genistein is a soy-derived phytoestrogen and its inhibitory effect on leiomyoma cell proliferation is reported. In this study, we investigated the siginificant inhibitory effect of genistein on estradiol (E(2))-induced leiomyoma cells proliferation. The Eker rat-derived uterine leiomyoma cell line ELT-3 cells were used. Cell proliferation was assessed by counting the number of cells. The expression of estrogen receptors and peroxisome proliferator-activated receptor-gamma (PPARgamma) was evaluated by Western blot analysis. PPARgamma was expressed in ELT-3 cells and genistein acted as PPARgamma ligand. This inhibitory effect of genistein was attenuated by the treatment of cells with PPARgamma antagonist bisphenol A diglycidyl ether (BADGE) or GW9662. These experimental findings in vitro show that the repressive effect of genistein on E(2)-induced ELT-3 cell proliferation is through the activation of PPARgamma. Genistein may be useful as an alternative therapy for leiomyoma.

miR-613 inhibits proliferation and invasion of breast cancer cell via VEGFA

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

Wu, Junzhao; Yuan, Peng; Mao, Qixin

MicroRNAs (miRNAs) play important roles in the pathogenesis of many types of cancers by negatively regulating gene expression at posttranscriptional level. However, the role of microRNAs in breast cancer, has remained elusive. Here, we identified that miR-613 inhibits breast cancer cell proliferation by negatively regulates its target gene VEGFA. In breast cancer cell lines, CCK-8 proliferation assay indicated that the cell proliferation was inhibited by miR-613, while miR-613 inhibitor significantly promoted the cell proliferation. Transwell assay showed that miR-613 mimics significantly inhibited the migration and invasion of breast cancer cells, whereas miR-613 inhibitors significantly increased cell migration and invasion. Luciferasemore » assays confirmed that miR-613 directly bound to the 3′ untranslated region of VEGFA, and western blotting showed that miR-613 suppressed the expression of VEGFA at the protein levels. This study indicated that miR-613 negatively regulates VEGFA and inhibits proliferation and invasion of breast cancer cell lines. Thus, miR-613 may represent a potential therapeutic molecule for breast cancer intervention.« less

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

Proliferation Control Regimes: Background and Status

DTIC Science & Technology

2006-12-26

developing a national capability to conduct forensic analysis of evidence from bio-crimes and terrorism. Given the difficulty of differentiating between...North Korea in 2004 galvanized the international community to examine strengthening implementation of national export controls and interdiction ... interdiction of WMD-related equipment shipments at sea, on land, and by air. President Bush announced the Proliferation Security Initiative (PSI) on May 31

Worldwide Report, Nuclear Development and Proliferation

DTIC Science & Technology

1984-05-14

PROLIFERATION IMC QUALITY: 19980729 081 FBIS FOREIGN BROADCAST INFORMATION SERVICE REPRODUCED BY NATIONAL TECHNICAL INFORMATION SERVICE U.S...Information Service , Springfield, Virginia 22161. In order- ing, it is recommended that the JPRS number, title, date and author, if applicable, of...Information Service , and are listed in the Monthly Catalog of U.S. Government Publications issued by the Superintendent of Documents, U.S. Government

PKA and Epac synergistically inhibit smooth muscle cell proliferation

PubMed Central

Hewer, Richard C.; Sala-Newby, Graciela B.; Wu, Yih-Jer; Newby, Andrew C.; Bond, Mark

2011-01-01

Cyclic AMP signalling promotes VSMC quiescence in healthy vessels and during vascular healing following injury. Cyclic AMP inhibits VSMC proliferation via mechanisms that are not fully understood. We investigated the role of PKA and Epac signalling on cAMP-induced inhibition of VSMC proliferation. cAMP-mediated growth arrest was PKA-dependent. However, selective PKA activation with 6-Benzoyl-cAMP did not inhibit VSMC proliferation, indicating a requirement for additional pathways. Epac activation using the selective cAMP analogue 8-CPT-2′-O-Me-cAMP, did not affect levels of hyperphosphorylated Retinoblastoma (Rb) protein, a marker of G1-S phase transition, or BrdU incorporation, despite activation of the Epac-effector Rap1. However, 6-Benzoyl-cAMP and 8-CPT-2′-O-Me-cAMP acted synergistically to inhibit Rb-hyperphosphorylation and BrdU incorporation, indicating that both pathways are required for growth inhibition. Consistent with this, constitutively active Epac increased Rap1 activity and synergised with 6-Benzoyl-cAMP to inhibit VSMC proliferation. PKA and Epac synergised to inhibit phosphorylation of ERK and JNK. Induction of stellate morphology, previously associated with cAMP-mediated growth arrest, was also dependent on activation of both PKA and Epac. Rap1 inhibition with Rap1GAP or siRNA silencing did not negate forskolin-induced inhibition of Rb-hyperphosphorylation, BrdU incorporation or stellate morphology. This data demonstrates for the first time that Epac synergises with PKA via a Rap1-independent mechanism to mediate cAMP-induced growth arrest in VSMC. This work highlights the role of Epac as a major player in cAMP-dependent growth arrest in VSMC. PMID:20971121

ALG2 regulates glioblastoma cell proliferation, migration and tumorigenicity

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

Zhang, Dunke; Wang, Feng; Pang, Yi

Apoptosis-linked gene-2 (ALG-2), also known as programmed cell death 6 (PDCD6), has recently been reported to be aberrantly expressed in various tumors and required for tumor cell viability. The aim of the present study was to investigate whether ALG-2 plays a crucial role in tumor cell proliferation, migration and tumorigenicity. In this study, we examined the expression of PDCD6 in glioblastoma cell lines and found that ALG-2 was generally expressed in glioblastoma cell lines. We also performed an analysis of an online database and found that high expression of ALG-2 was associated with poor prognosis (p = 0.039). We found that over-expressionmore » of ALG2 in glioblastoma could inhibit cell proliferation and, conversely, that down-regulation of ALG2 could promote cell proliferation. Further studies showed that over-expression of ALG2 inhibited the migration of tumor cells, whereas down-regulation of ALG2 promoted tumor cell migration. Finally, in vitro and in vivo studies showed that over-expression of ALG2 inhibited the tumorigenic ability of tumor cells, while down-regulation of ALG2 promoted tumor cell tumorigenic ability. In conclusion, ALG2 has a tumor suppressive role in glioblastoma and might be a potential target for the treatment of glioblastoma. - Highlights: • Low ALG2 expression is indicative of poor prognosis in glioblastoma patients. • ALG2 is required for cell proliferation in GBM cells. • ALG2 is involved in GBM cell migration. • ALG2 is involved in GBM cell self-renewal and tumorigenesis in vitro and in vivo.« less

Genetic Abolishment of Hepatocyte Proliferation Activates Hepatic Stem Cells

PubMed Central

Endo, Yoko; Zhang, Mingjun; Yamaji, Sachie; Cang, Yong

2012-01-01

Quiescent hepatic stem cells (HSCs) can be activated when hepatocyte proliferation is compromised. Chemical injury rodent models have been widely used to study the localization, biomarkers, and signaling pathways in HSCs, but these models usually exhibit severe promiscuous toxicity and fail to distinguish damaged and non-damaged cells. Our goal is to establish new animal models to overcome these limitations, thereby providing new insights into HSC biology and application. We generated mutant mice with constitutive or inducible deletion of Damaged DNA Binding protein 1 (DDB1), an E3 ubiquitin ligase, in hepatocytes. We characterized the molecular mechanism underlying the compensatory activation and the properties of oval cells (OCs) by methods of mouse genetics, immuno-staining, cell transplantation and gene expression profiling. We show that deletion of DDB1 abolishes self-renewal capacity of mouse hepatocytes in vivo, leading to compensatory activation and proliferation of DDB1-expressing OCs. Partially restoring proliferation of DDB1-deficient hepatocytes by ablation of p21, a substrate of DDB1 E3 ligase, alleviates OC proliferation. Purified OCs express both hepatocyte and cholangiocyte markers, form colonies in vitro, and differentiate to hepatocytes after transplantation. Importantly, the DDB1 mutant mice exhibit very minor liver damage, compared to a chemical injury model. Microarray analysis reveals several previously unrecognized markers, including Reelin, enriched in oval cells. Here we report a genetic model in which irreversible inhibition of hepatocyte duplication results in HSC-driven liver regeneration. The DDB1 mutant mice can be broadly applied to studies of HSC differentiation, HSC niche and HSCs as origin of liver cancer. PMID:22384083

Cell cycles and proliferation patterns in Haematococcus pluvialis

NASA Astrophysics Data System (ADS)

Zhang, Chunhui; Liu, Jianguo; Zhang, Litao

2017-09-01

Most studies on Haematococcus pluvialis have been focused on cell growth and astaxanthin accumulation; far less attention has been paid to cell cycles and proliferation patterns. The purpose of this study was to clarify cell cycles and proliferation patterns in H. pluvialis microscopically using a camera and video recorder system. The complicated life history of H. pluvialis can be divided into two stages: the motile stage and the non-motile stage. All the cells can be classified into forms as follows: motile cell, nonmotile cell, zoospore and aplanospore. The main cell proliferation, both in the motile phase and non-motile phase in H. pluvialis, is by asexual reproduction. Under normal growth conditions, a motile cell usually produces two, sometimes four, and exceptionally eight zoospores. Under unfavorable conditions, the motile cell loses its flagella and transforms into a non-motile cell, and the non-motile cell usually produces 2, 4 or 8 aplanospores, and occasionally 20-32 aplanospores, which further develop into non-motile cells. Under suitable conditions, the non-motile cell is also able to release zoospores. The larger non-motile cells produce more than 16 zoospores, and the smaller ones produce 4 or 8 zoospores. Vegetative reproduction is by direct cell division in the motile phase and by occasional cell budding in the non-motile phase. There is, as yet, no convincing direct evidence for sexual reproduction.

Long-term proliferation and safeguards issues in future technologies

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

Keisch, B.; Auerbach, C.; Fainberg, A.

1986-02-01

The purpose of the task was to assess the effect of potential new technologies, nuclear and non-nuclear, on safeguards needs and non-proliferation policies, and to explore possible solutions to some of the problems envisaged. Eight subdivisions were considered: New Enrichment Technologies; Non-Aqueous Reprocessing Technologies; Fusion; Accelerator-Driven Reactor Systems; New Reactor Types; Heavy Water and Deuterium; Long-Term Storage of Spent Fuel; and Other Future Technologies (Non-Nuclear). For each of these subdivisions, a careful review of the current world-wide effort in the field provided a means of subjectively estimating the viability and qualitative probability of fruition of promising technologies. Technologies for whichmore » safeguards and non-proliferation requirements have been thoroughly considered by others were not restudied here (e.g., the Fast Breeder Reactor). The time scale considered was 5 to 40 years for possible initial demonstration although, in some cases, a somewhat optimistic viewpoint was embraced. Conventional nuclear-material safeguards are only part of the overall non-proliferation regime. Other aspects are international agreements, export controls on sensitive technologies, classification of information, intelligence gathering, and diplomatic initiatives. The focus here is on safeguards, export controls, and classification.« less

Inhibition of brain tumor cell proliferation by alternating electric fields

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

Jeong, Hyesun; Oh, Seung-ick; Hong, Sunghoi, E-mail: shong21@korea.ac.kr, E-mail: radioyoon@korea.ac.kr

2014-11-17

This study was designed to investigate the mechanism by which electric fields affect cell function, and to determine the optimal conditions for electric field inhibition of cancer cell proliferation. Low-intensity (<2 V/cm) and intermediate-frequency (100–300 kHz) alternating electric fields were applied to glioblastoma cell lines. These electric fields inhibited cell proliferation by inducing cell cycle arrest and abnormal mitosis due to the malformation of microtubules. These effects were significantly dependent on the intensity and frequency of applied electric fields.

Co-culture with Sertoli cells promotes proliferation and migration of umbilical cord mesenchymal stem cells

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

Zhang, Fenxi, E-mail: fxzhang0824@gmail.com; Hong, Yan; Liang, Wenmei

Highlights: Black-Right-Pointing-Pointer Co-culture of Sertoli cells (SCs) with human umbilical cord mesenchymal stem cells (UCMSCs). Black-Right-Pointing-Pointer Presence of SCs dramatically increased proliferation and migration of UCMSCs. Black-Right-Pointing-Pointer Presence of SCs stimulated expression of Mdm2, Akt, CDC2, Cyclin D, CXCR4, MAPKs. -- Abstract: Human umbilical cord mesenchymal stem cells (hUCMSCs) have been recently used in transplant therapy. The proliferation and migration of MSCs are the determinants of the efficiency of MSC transplant therapy. Sertoli cells are a kind of 'nurse' cells that support the development of sperm cells. Recent studies show that Sertoli cells promote proliferation of endothelial cells and neuralmore » stem cells in co-culture. We hypothesized that co-culture of UCMSCs with Sertoli cells may also promote proliferation and migration of UCMSCs. To examine this hypothesis, we isolated UCMSCs from human cords and Sertoli cells from mouse testes, and co-cultured them using a Transwell system. We found that UCMSCs exhibited strong proliferation ability and potential to differentiate to other cell lineages such as osteocytes and adipocytes. The presence of Sertoli cells in co-culture significantly enhanced the proliferation and migration potential of UCMSCs (P < 0.01). Moreover, these phenotypic changes were accompanied with upregulation of multiple genes involved in cell proliferation and migration including phospho-Akt, Mdm2, phospho-CDC2, Cyclin D1, Cyclin D3 as well as CXCR4, phospho-p44 MAPK and phospho-p38 MAPK. These findings indicate that Sertoli cells boost UCMSC proliferation and migration potential.« less

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.

Upregulation of GRAIL is associated with impaired CD4 T cell proliferation in sepsis.

PubMed

Aziz, Monowar; Yang, Weng-Lang; Matsuo, Shingo; Sharma, Archna; Zhou, Mian; Wang, Ping

2014-03-01

The loss of numbers and functionality of CD4 T cells is observed in sepsis; however, the mechanism remains elusive. Gene related to anergy in lymphocytes (GRAIL) is critical for the impairment of CD4 T cell proliferation. We therefore sought to examine the role of GRAIL in CD4 T cell proliferation during sepsis. Sepsis was induced in 10-wk-old male C57BL/6 mice by cecal ligation and puncture. Splenocytes were isolated and subjected to flow cytometry to determine CD4 T cell contents. CD4 T cell proliferation was assessed by CFSE staining, and the expression of GRAIL in splenocytes was measured by immunohistochemistry, real-time PCR, and flow cytometry. The expressions of IL-2 and early growth response-2 were determined by real-time PCR. As compared with shams, the numbers of CD4 T cells were significantly reduced in spleens. Septic CD4 T cells were less efficient in proliferation than shams. The IL-2 expression was significantly reduced, whereas the GRAIL expression was significantly increased in septic mice splenocytes as compared with shams. The small interfering RNA-mediated knockdown of GRAIL expression re-established the CD4 T cell proliferation ability ex vivo. Similarly, the treatment with recombinant murine IL-2 to the septic CD4 T cells restored their proliferation ability by downregulating GRAIL expression. Our findings reveal a novel association of the increased GRAIL expression with impaired CD4 T cell proliferation, implicating an emerging therapeutic tool in sepsis.

Exogenous hydrogen sulfide promotes cell proliferation and differentiation by modulating autophagy in human keratinocytes

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

Xie, Xin; Dai, Hui; Zhuang, Binyu

The effects and the underlying mechanisms of hydrogen sulfide (H{sub 2}S) on keratinocyte proliferation and differentiation are still less known. In the current study, we investigated the effects and the underlying mechanisms of exogenous H{sub 2}S on keratinocyte proliferation and differentiation. Human keratinocytes (HaCaT cells) were treated with various concentrations (0.05, 0.25, 0.5 and 1 mM) of sodium hydrosulfide (NaHS, a donor of H{sub 2}S) for 24 h. A CCK-8 assay was used to assess cell viability. Western blot analysis was performed to determine the expression levels of proteins associated with differentiation and autophagy. Transmission electron microscopy was performed to observe autophagicmore » vacuoles, and flow cytometry was applied to evaluate apoptosis. NaHS promoted the viability, induced the differentiation, and enhanced autophagic activity in a dose-dependent manner in HaCaT cells but had no effect on cell apoptosis. Blockage of autophagy by ATG5 siRNA inhibited NaHS-induced cell proliferation and differentiation. The current study demonstrated that autophagy in response to exogenous H{sub 2}S treatment promoted keratinocyte proliferation and differentiation. Our results provide additional insights into the potential role of autophagy in keratinocyte proliferation and differentiation. - Highlights: • Exogenous H{sub 2}S promotes keratinocyte proliferation and differentiation. • The effects of H{sub 2}S on proliferation and differentiation is modulated by autophagy. • Exogenous H{sub 2}S has no effect on keratinocyte apoptosis.« less

O-linked β-N-acetylglucosamine transferase directs cell proliferation in idiopathic pulmonary arterial hypertension.

PubMed

Barnes, Jarrod W; Tian, Liping; Heresi, Gustavo A; Farver, Carol F; Asosingh, Kewal; Comhair, Suzy A A; Aulak, Kulwant S; Dweik, Raed A

2015-04-07

Idiopathic pulmonary arterial hypertension (IPAH) is a cardiopulmonary disease characterized by cellular proliferation and vascular remodeling. A more recently recognized characteristic of the disease is the dysregulation of glucose metabolism. The primary link between altered glucose metabolism and cell proliferation in IPAH has not been elucidated. We aimed to determine the relationship between glucose metabolism and smooth muscle cell proliferation in IPAH. Human IPAH and control patient lung tissues and pulmonary artery smooth muscle cells (PASMCs) were used to analyze a specific pathway of glucose metabolism, the hexosamine biosynthetic pathway. We measured the levels of O-linked β-N-acetylglucosamine modification, O-linked β-N-acetylglucosamine transferase (OGT), and O-linked β-N-acetylglucosamine hydrolase in control and IPAH cells and tissues. Our data suggest that the activation of the hexosamine biosynthetic pathway directly increased OGT levels and activity, triggering changes in glycosylation and PASMC proliferation. Partial knockdown of OGT in IPAH PASMCs resulted in reduced global O-linked β-N-acetylglucosamine modification levels and abrogated PASMC proliferation. The increased proliferation observed in IPAH PASMCs was directly impacted by proteolytic activation of the cell cycle regulator, host cell factor-1. Our data demonstrate that hexosamine biosynthetic pathway flux is increased in IPAH and drives OGT-facilitated PASMC proliferation through specific proteolysis and direct activation of host cell factor-1. These findings establish a novel regulatory role for OGT in IPAH, shed a new light on our understanding of the disease pathobiology, and provide opportunities to design novel therapeutic strategies for IPAH. © 2015 American Heart Association, Inc.

Endothelial progenitor cells proliferated via MEK-dependent p42 MAPK signaling pathway.

PubMed

Sandra, Ferry; Oktaviono, Yudi Her; Widodo, Mohammad Aris; Dirgantara, Yanni; Chouw, Angliana; Sargowo, Djanggan

2015-02-01

Endothelial progenitor cells (EPCs) clinical applications have been well reported. However, due to low number of EPCs that could be isolated, EPCs expansion study became one of the main focuses. Some optimized mediums to culture EPCs were currently available. However, the proliferation signaling pathway is not clearly disclosed yet. Peripheral blood was collected from eight healthy subjects, followed by mononuclear cells (MNCs) isolation. MNCs were then prepared and cultured for 2 days. After that, non-adherent cells were harvested and further cultured for 3 days. Resulted colony-forming unit (CFU)-Hill colonies were documented and enumerated under an inverted light microscope. To detect membrane markers, immunofluorescence was performed to detect CD34, VEGFR-2, and CD133. Cell documentation was conducted under a fluorescence microscope. To check cell proliferation, XTT Cell Proliferation Assay Kit was used according to kit insert. To detect possible activation of p44/42 MAPK, western blot was performed to detect p44/42 MAPK and phosphorylated p44/42 MAPK. All visualized bands were captured and quantified. Our results showed that EPCs markers (CD34, CD133 and VEGFR-2) were detected in 3 days culture. From XTT cell proliferation assay and CFU enumeration results, we found that EPCs proliferated significantly (p = 0.012) with addition of supplement. Phosphorylated-p42 MAPK expression of EPCs treated with supplement was significantly higher than the one of EPCs without treatment. Significant inhibition of p42 MAPK phosphorylation by U0126 was observed (p = 0.012). By pretreatment of U0126, number of viable cells and CFUs treated with supplement was significantly decreased (p = 0.012). Our results showed that MEK-dependent p42 MAPK pathway might play an important role in EPCs proliferation.

Nerves Regulate Cardiomyocyte Proliferation and Heart Regeneration.

PubMed

Mahmoud, Ahmed I; O'Meara, Caitlin C; Gemberling, Matthew; Zhao, Long; Bryant, Donald M; Zheng, Ruimao; Gannon, Joseph B; Cai, Lei; Choi, Wen-Yee; Egnaczyk, Gregory F; Burns, Caroline E; Burns, C Geoffrey; MacRae, Calum A; Poss, Kenneth D; Lee, Richard T

2015-08-24

Some organisms, such as adult zebrafish and newborn mice, have the capacity to regenerate heart tissue following injury. Unraveling the mechanisms of heart regeneration is fundamental to understanding why regeneration fails in adult humans. Numerous studies have revealed that nerves are crucial for organ regeneration, thus we aimed to determine whether nerves guide heart regeneration. Here, we show using transgenic zebrafish that inhibition of cardiac innervation leads to reduction of myocyte proliferation following injury. Specifically, pharmacological inhibition of cholinergic nerve function reduces cardiomyocyte proliferation in the injured hearts of both zebrafish and neonatal mice. Direct mechanical denervation impairs heart regeneration in neonatal mice, which was rescued by the administration of neuregulin 1 (NRG1) and nerve growth factor (NGF) recombinant proteins. Transcriptional analysis of mechanically denervated hearts revealed a blunted inflammatory and immune response following injury. These findings demonstrate that nerve function is required for both zebrafish and mouse heart regeneration. Copyright © 2015 Elsevier Inc. All rights reserved.

Ki67 and proliferation in breast cancer.

PubMed

Pathmanathan, Nirmala; Balleine, Rosemary L

2013-06-01

New approaches to the prognostic assessment of breast cancer have come from molecular profiling studies. A major feature of this work has been to emphasise the importance of cancer cell proliferation as a key discriminative indicator of recurrence risk for oestrogen receptor positive breast cancer in particular. Mitotic count scoring, as a component of histopathological grade, has long formed part of a routine evaluation of breast cancer biology. However, there is an increasingly compelling case to include a specific proliferation score in breast cancer pathology reports based on expression of the cell cycle regulated protein Ki67. Immunohistochemical staining for Ki67 is a widely available and economical test with good tolerance of pre-analytical variations and staining conditions. However, there is currently no evidence based protocol established to derive a reliable and informative Ki67 score for routine clinical use. In this circumstance, pathologists must establish a standardised framework for scoring Ki67 and communicating results to a multidisciplinary team.

Microfluidic devices for cell cultivation and proliferation

PubMed Central

Tehranirokh, Masoomeh; Kouzani, Abbas Z.; Francis, Paul S.; Kanwar, Jagat R.

2013-01-01

Microfluidic technology provides precise, controlled-environment, cost-effective, compact, integrated, and high-throughput microsystems that are promising substitutes for conventional biological laboratory methods. In recent years, microfluidic cell culture devices have been used for applications such as tissue engineering, diagnostics, drug screening, immunology, cancer studies, stem cell proliferation and differentiation, and neurite guidance. Microfluidic technology allows dynamic cell culture in microperfusion systems to deliver continuous nutrient supplies for long term cell culture. It offers many opportunities to mimic the cell-cell and cell-extracellular matrix interactions of tissues by creating gradient concentrations of biochemical signals such as growth factors, chemokines, and hormones. Other applications of cell cultivation in microfluidic systems include high resolution cell patterning on a modified substrate with adhesive patterns and the reconstruction of complicated tissue architectures. In this review, recent advances in microfluidic platforms for cell culturing and proliferation, for both simple monolayer (2D) cell seeding processes and 3D configurations as accurate models of in vivo conditions, are examined. PMID:24273628

Mitochondrial Superoxide Production Negatively Regulates Neural Progenitor Proliferation and Cerebral Cortical Development

PubMed Central

Hou, Yan; Ouyang, Xin; Wan, Ruiqian; Cheng, Heping; Mattson, Mark P.; Cheng, Aiwu

2012-01-01

Although high amounts of reactive oxygen species (ROS) can damage cells, ROS can also play roles as second messengers, regulating diverse cellular processes. Here we report that embryonic mouse cerebral cortical neural progenitor cells (NPCs) exhibit intermittent spontaneous bursts of mitochondrial superoxide (SO) generation (mitochondrial SO flashes) that require transient opening of membrane permeability transition pores (mPTP). This quantal SO production negatively regulates NPC self-renewal. Mitochondrial SO scavengers and mPTP inhibitors reduce SO flash frequency and enhance NPC proliferation, whereas prolonged mPTP opening and SO generation increase SO flash incidence and decrease NPC proliferation. The inhibition of NPC proliferation by mitochondrial SO involves suppression of extracellular signal-regulated kinases. Moreover, mice lacking SOD2 (SOD2−/− mice) exhibit significantly fewer proliferative NPCs and differentiated neurons in the embryonic cerebral cortex at mid-gestation compared with wild type littermates. Cultured SOD2−/− NPCs exhibit a significant increase in SO flash frequency and reduced NPC proliferation. Taken together, our findings suggest that mitochondrial SO flashes negatively regulate NPC self-renewal in the developing cerebral cortex. PMID:22949407

Role of Dicer1 in thyroid cell proliferation and differentiation.

PubMed

Penha, Ricardo Cortez Cardoso; Sepe, Romina; De Martino, Marco; Esposito, Francesco; Pellecchia, Simona; Raia, Maddalena; Del Vecchio, Luigi; Decaussin-Petrucci, Myriam; De Vita, Gabriella; Pinto, Luis Felipe Ribeiro; Fusco, Alfredo

2017-01-01

DICER1 plays a central role in the biogenesis of microRNAs and it is important for normal development. Altered microRNA expression and DICER1 dysregulation have been described in several types of tumors, including thyroid carcinomas. Recently, our group identified a new somatic mutation (c.5438A>G; E1813G) within DICER1 gene of an unknown function. Herein, we show that DICER1 is overexpressed, at mRNA level, in a significant-relative number of papillary (70%) and anaplastic (42%) thyroid carcinoma samples, whereas is drastically downregulated in all the analyzed human thyroid carcinoma cell lines (TPC-1, BCPAP, FRO and 8505c) in comparison with normal thyroid tissue samples. Conversely, DICER1 is downregulated, at protein level, in PTC in comparison with normal thyroid tissues. Our data also reveals that DICER1 overexpression positively regulates thyroid cell proliferation, whereas its silencing impairs thyroid cell differentiation. The expression of DICER1 gene mutation (c.5438A>G; E1813G) negatively affects the microRNA machinery and cell proliferation as well as upregulates DICER1 protein levels of thyroid cells but has no impact on thyroid differentiation. In conclusion, DICER1 protein is downregulated in papillary thyroid carcinomas and affects thyroid proliferation and differentiation, while DICER1 gene mutation (c.5438A>G; E1813G) compromises the DICER1 wild-type-mediated microRNA processing and cell proliferation.

Social Competition in Rats: Cell Proliferation and Behavior

PubMed Central

Hoshaw, Brian A.; Evans, Jennifer C.; Mueller, Bridget; Valentino, Rita J.; Lucki, Irwin

2007-01-01

Behavioral and physiological changes were studied following prolonged exposure to social competition in pairs of non food-deprived rats competing daily for a limited supply of graham cracker crumbs. Stable dominant-subordinate relationships developed in most pairs, as measured by feeding time, which were maintained over a 5–6-week study period. In other behavioral tests, subordinates demonstrated a decreased latency to immobility in the forced swim test compared with dominants, but no difference in locomotor activity. Subordinates had increased bladder size, decreased adrenal gland size, and a 35% reduction of hippocampus cell proliferation compared with the dominant member. Therefore, prolonged social competition, based on restricted access to palatable substances, produced hierarchies among individuals that were associated with differences in behavior, physiology and hippocampal cell proliferation. PMID:17045347

Reducing Proliferation Rick Through Multinational Fuel Cycle Facilities

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

Amanda Rynes

2010-11-01

With the prospect of rapid expansion of the nuclear energy industry and the ongoing concern over weapons proliferation, there is a growing need for a viable alternative to traditional nation-based fuel production facilities. While some in the international community remain apprehensive, the advantages of multinational fuel cycle facilities are becoming increasingly apparent, with states on both sides of the supply chain able to garner the security and financial benefits of such facilities. Proliferation risk is minimized by eliminating the need of states to establish indigenous fuel production capabilities and the concept's structure provides an additional internationally monitored barrier against themore » misuse or diversion of nuclear materials. This article gives a brief description of the arguments for and against the implementation of a complete multinational fuel cycle.« less

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

Annexin V-induced rat Leydig cell proliferation involves Ect2 via RhoA/ROCK signaling pathway.

PubMed

Jing, Jun; Chen, Li; Fu, Hai-Yan; Fan, Kai; Yao, Qi; Ge, Yi-Feng; Lu, Jin-Chun; Yao, Bing

2015-03-24

This study investigated the effect of annexin V on the proliferation of primary rat Leydig cells and the potential mechanism. Our results showed that annexin V promoted rat Leydig cell proliferation and cell cycle progression in a dose- and time-dependent manner. Increased level of annexin V also enhanced Ect2 protein expression. However, siRNA knockdown of Ect2 attenuated annexin V-induced proliferation of rat Leydig cells. Taken together, these data suggest that increased level of annexin V induced rat Leydig cell proliferation and cell cycle progression via Ect2. Since RhoA activity was increased following Ect2 activation, we further investigated whether Ect2 was involved in annexin V-induced proliferation via the RhoA/ROCK pathway, and the results showed that annexin V increased RhoA activity too, and this effect was abolished by the knockdown of Ect2. Moreover, inhibition of the RhoA/ROCK pathway by a ROCK inhibitor, Y27632, also attenuated annexin V-induced proliferation and cell cycle progression. We thus conclude that Ect2 is involved in annexin V-induced rat Leydig cell proliferation through the RhoA/ROCK pathway.

Advanced glycation end products increase carbohydrate responsive element binding protein expression and promote cancer cell proliferation.

PubMed

Chen, Hanbei; Wu, Lifang; Li, Yakui; Meng, Jian; Lin, Ning; Yang, Dianqiang; Zhu, Yemin; Li, Xiaoyong; Li, Minle; Xu, Ye; Wu, Yuchen; Tong, Xuemei; Su, Qing

2014-09-01

Diabetic patients have increased levels of advanced glycation end products (AGEs) and the role of AGEs in regulating cancer cell proliferation is unclear. Here, we found that treating colorectal and liver cancer cells with AGEs promoted cell proliferation. AGEs stimulated both the expression and activation of a key transcription factor called carbohydrate responsive element binding protein (ChREBP) which had been shown to promote glycolytic and anabolic activity as well as proliferation of colorectal and liver cancer cells. Using siRNAs or the antagonistic antibody for the receptor for advanced glycation end-products (RAGE) blocked AGEs-induced ChREBP expression or cell proliferation in cancer cells. Suppressing ChREBP expression severely impaired AGEs-induced cancer cell proliferation. Taken together, these results demonstrate that AGEs-RAGE signaling enhances cancer cell proliferation in which AGEs-mediated ChREBP induction plays an important role. These findings may provide new explanation for increased cancer progression in diabetic patients. Copyright © 2014. Published by Elsevier Ireland Ltd.

Control of proliferation rate of N27 dopaminergic neurons using Transcranial Magnetic Stimulation orientation

NASA Astrophysics Data System (ADS)

Meng, Yiwen; Hadimani, Ravi; Anantharam, Vellareddy; Kanthasamy, Anumantha; Jiles, David

2015-03-01

Transcranial magnetic stimulation (TMS) has been used to investigate possible treatments for a variety of neurological disorders. However, the effect that magnetic fields have on neurons has not been well documented in the literature. We have investigated the effect of different orientation of magnetic field generated by TMS coils with a monophasic stimulator on the proliferation rate of N27 neuronal cells cultured in flasks and multi-well plates. The proliferation rate of neurons would increase by exposed horizontally adherent N27 cells to a magnetic field pointing upward through the neuronal proliferation layer compared with the control group. On the other hand, proliferation rate would decrease in cells exposed to a magnetic field pointing downward through the neuronal growth layer compared with the control group. We confirmed results obtained from the Trypan-blue and automatic cell counting methods with those from the CyQuant and MTS cell viability assays. Our findings could have important implications for the preclinical development of TMS treatments of neurological disorders and represents a new method to control the proliferation rate of neuronal cells.

Apigenin inhibits TGF-β1-induced proliferation and migration of airway smooth muscle cells.

PubMed

Li, Li-Hua; Lu, Bin; Wu, Hong-Ke; Zhang, Hao; Yao, Fei-Fei

2015-01-01

It is well known that the proliferation and migration of ASM cells (ASMCs) plays an important role in the pathogenesis of airway remodeling in asthma. Previous studies reported that apigenin can inhibit airway remodeling in a mouse asthma model. However, its effects on the proliferation and migration of ASMCs in asthma remain unknown. Therefore, the aim of our present study was to investigate the effects of apigenin on ASMC proliferation and migration, and explore the possible molecular mechanism. We found that apigenin inhibited transforming growth factor-β1 (TGF-β1)-induced ASMC proliferation. The cell cycle was blocked at G1/S-interphase by apigenin. It also suppressed TGF-β1-induced ASMCs migration. Furthermore, apigenin inhibited TGF-β1-induced Smad 2 and Smad 3 phosphorylation in ASMCs. Taken together, these results suggested that apigenin inhibited the proliferation and migration of TGF-β1-stimulated ASMCs by inhibiting Smad signaling pathway. These data might provide useful information for treating asthma and show that apigenin has potential for attenuating airway remodeling.

Effect of chronic aspirin ingestion on epithelial proliferation in rat fundus, antrum, and duodenum

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

Eastwood, G.L.; Quimby, G.F.

We studied the effect of chronic aspirin ingestion on gastroduodenal epithelial proliferation by feeding rats aspirin in the drinking water. A control group of rats received plain water. At the end of 4 wk, (3H)-thymidine was given intravenously to label proliferating cells, and the rats were killed 1 h later. Sections of fundus, antrum, and proximal duodenum were processed for light autoradiography. We found that chronic aspirin ingestion stimulated epithelial proliferation in fundic mucosa but had no effect in the antrum. In the duodenum, aspirin increased proliferation in the lowest four crypt-cell positions, which most likely indicates an increase inmore » stem-cell production. None of the tissues contained evidence of inflammation or ulceration. The proliferative effects of aspirin may help explain the previously observed phenomenon of mucosal adaptation in the rat after repeated exposure to aspirin. Further, if human gastroduodenal epithelium responds in a similar manner to chronic aspirin exposure, the effects on proliferation may explain in part the distribution of aspirin-associated ulcers.« less

GPER mediates estrogen-induced signaling and proliferations in human breast epithelial cells, and normal and malignant breast

PubMed Central

Scaling, Allison L.

2014-01-01

17β-estradiol (estrogen), through receptor binding and activation, is required for mammary gland development. Estrogen stimulates epithelial proliferation in the mammary gland, promoting ductal elongation and morphogenesis. In addition to a developmental role, estrogen promotes proliferation in tumorigenic settings, particularly breast cancer. The proliferative effects of estrogen in the normal breast and breast tumors are attributed to estrogen receptor α. Although in vitro studies have demonstrated that the G protein-coupled estrogen receptor (GPER, previously called GPR30) can modulate proliferation in breast cancer cells both positively and negatively depending on cellular context, its role in proliferation in the intact normal or malignant breast remains unclear. Estrogen-induced GPER-dependent proliferation was assessed in the immortalized non-tumorigenic human breast epithelial cell line, MCF10A, and an ex vivo organ culture model employing human breast tissue from reduction mammoplasty or tumor resections. Stimulation by estrogen and the GPER-selective agonist G-1 increased the mitotic index in MCF10A cells and proportion of cells in the cell cycle in human breast and breast cancer explants, suggesting increased proliferation. Inhibition of candidate signaling pathways that may link GPER activation to proliferation revealed a dependence on Src, epidermal growth factor receptor transactivation by heparin-bound EGF and subsequent ERK phosphorylation. Proliferation was not dependent on matrix metalloproteinase cleavage of membrane bound pro-HB-EGF. The contribution of GPER to estrogen-induced proliferation in MCF10A cells and breast tissue was confirmed by the ability of GPER-selective antagonist G36 to abrogate estrogen- and G-1-induced proliferation, and the ability of siRNA knockdown of GPER to reduce estrogen- and G-1-induced proliferation in MCF10A cells. This is the first study to demonstrate GPER-dependent proliferation in primary normal and malignant

Interleukin-15 regulates proliferation and self-renewal of adult neural stem cells

PubMed Central

Gómez-Nicola, Diego; Valle-Argos, Beatriz; Pallas-Bazarra, Noemí; Nieto-Sampedro, Manuel

2011-01-01

The impact of inflammation is crucial for the regulation of the biology of neural stem cells (NSCs). Interleukin-15 (IL-15) appears as a likely candidate for regulating neurogenesis, based on its well-known mitogenic properties. We show here that NSCs of the subventricular zone (SVZ) express IL-15, which regulates NSC proliferation, as evidenced by the study of IL-15−/− mice and the effects of acute IL-15 administration, coupled to 5-bromo-2′-deoxyuridine/5-ethynyl-2′-deoxyuridine dual-pulse labeling. Moreover, IL-15 regulates NSC differentiation, its deficiency leading to an impaired generation of neuroblasts in the SVZ–rostral migratory stream axis, recoverable through the action of exogenous IL-15. IL-15 expressed in cultured NSCs is linked to self-renewal, proliferation, and differentiation. IL-15–/– NSCs presented deficient proliferation and self-renewal, as evidenced in proliferation and colony-forming assays and the analysis of cell cycle–regulatory proteins. Moreover, IL-15–deficient NSCs were more prone to differentiate than wild-type NSCs, not affecting the cell population balance. Lack of IL-15 led to a defective activation of the JAK/STAT and ERK pathways, key for the regulation of proliferation and differentiation of NSCs. The results show that IL-15 is a key regulator of neurogenesis in the adult and is essential to understanding diseases with an inflammatory component. PMID:21508317

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.

Essential components for ex vivo proliferation of mesenchymal stromal cells.

PubMed

Fekete, Natalie; Rojewski, Markus Thomas; Lotfi, Ramin; Schrezenmeier, Hubert

2014-02-01

Mesenchymal stromal cells (MSCs) are highly interesting candidates for clinical applications in regenerative medicine. Due to their low occurrence in human tissues, extensive in vitro expansion is necessary to obtain sufficient cell numbers applicable as a clinical dose in the context of cellular therapy. Current cell culture media formulations for the isolation and expansion of MSCs include fetal calf serum (FCS), human AB serum (ABS), or human platelet lysate (PL) as a supplement. However, these established supplements are inherently ill-defined formulations that contain a variety of bioactive molecules in varying batch-to-batch compositions and the risk of transmitting pathogens that escape routine screening procedures. In this study, we have comparatively characterized the capacity of commonly used basal media, such as the Minimum Essential Medium alpha (αMEM), Dulbecco's modified Eagle's medium (DMEM), Iscove's Modified Dulbecco's Medium (IMDM), and RPMI 1640 as well as human- and animal-derived supplements, that is, PL, ABS, and FCS to stimulate cell proliferation. MSC proliferation was observed to be optimal in the PL-supplemented αMEM. Using a combinatorial approach, we then assessed a library of soluble factors, including mitogens (TGF-β1, Activin A, bFGF, EGF, IGF-I, PDGF-BB, and VEGF), chemokines (CCL21, CCL25, CXCL12, and RANTES), proteins (human serum albumin), lipids (e.g., oleic acid, linoleic acid, and arachidonic acid), and hormones (dexamethasone, insulin, and TSH), to create a defined medium as well as coating of cell culture surfaces to promote robust MSC proliferation in vitro. A combination of recombinant human factors partially met the nutritional requirements of bone marrow-derived MSCs, and was able to promote cell proliferation comparable to about 5% PL if supplemented with auxiliary 0.6%-1.2% PL. Maximal MSC proliferation was achieved by combining 5% PL with a cocktail of recombinant factors and did not depend on coating of cell

Dynamics of cell proliferation in the adult dentate gyrus of two inbred strains of mice

NASA Technical Reports Server (NTRS)

Hayes, N. L.; Nowakowski, R. S.

2002-01-01

The output potential of proliferating populations in either the developing or the adult nervous system is critically dependent on the length of the cell cycle (T(c)) and the size of the proliferating population. We developed a new approach for analyzing the cell cycle, the 'Saturate and Survive Method' (SSM), that also reveals the dynamic behaviors in the proliferative population and estimates of the size of the proliferating population. We used this method to analyze the proliferating population of the adult dentate gyrus in 60 day old mice of two inbred strains, C57BL/6J and BALB/cByJ. The results show that the number of cells labeled by exposure to BUdR changes dramatically with time as a function of the number of proliferating cells in the population, the length of the S-phase, cell division, the length of the cell cycle, dilution of the S-phase label, and cell death. The major difference between C57BL/6J and BALB/cByJ mice is the size of the proliferating population, which differs by a factor of two; the lengths of the cell cycle and the S-phase and the probability that a newly produced cell will die within the first 10 days do not differ in these two strains. This indicates that genetic regulation of the size of the proliferating population is independent of the genetic regulation of cell death among those newly produced cells. The dynamic changes in the number of labeled cells as revealed by the SSM protocol also indicate that neither single nor repeated daily injections of BUdR accurately measure 'proliferation.'.

Branches of NF-κb signaling pathway regulate hepatocyte proliferation in rat liver regeneration.

PubMed

Chang, C F; Zhao, W M; Mei, J X; Zhou, Y; Pan, C Y; Xu, T T; Xu, C S

2015-07-13

Previous studies have demonstrated that the nuclear factor κB (NF-κB) pathway is involved in promoting cell proliferation. To further explore the regulatory branches and their sequence in the NF-κB pathway in the promotion of hepatocyte proliferation at the transcriptional level during rat liver regeneration, Rat Genome 230 2.0 array was used to detect the expression changes of the isolated hepatocytes. We found that many genes involved in the NF-κB pathway (including 73 known genes and 19 homologous genes) and cell proliferation (including 484 genes and 104 homologous genes) were associated with liver regeneration. Expression profile function (Ep) was used to analyze the biological processes. It was revealed that the NF-κB pathway promoted hepatocyte proliferation through three branches. Several methods of integrated statistics were applied to extract and screen key genes in liver regeneration, and it indicated that eight genes may play a vital role in rat liver regeneration. To confirm the above predicted results, Ccnd1, Jun and Myc were analyzed using qRT-PCR, and the results were generally consistent with that of microarray data. It is concluded that 3 branches and 8 key genes involved in the NF-κB pathway regulate hepatocyte proliferation during rat liver regeneration.

Fluoxetine Decreases the Proliferation and Adipogenic Differentiation of Human Adipose-Derived Stem Cells

PubMed Central

Sun, Bo Kyung; Kim, Ji Hye; Choi, Joon-Seok; Hwang, Sung-Joo; Sung, Jong-Hyuk

2015-01-01

Fluoxetine was originally developed as an antidepressant, but it has also been used to treat obesity. Although the anti-appetite effect of fluoxetine is well-documented, its potential effects on human adipose-derived stem cells (ASCs) or mature adipocytes have not been investigated. Therefore, we investigated the mechanisms underlying the inhibitory effects of fluoxetine on the proliferation of ASCs. We also investigated its inhibitory effect on adipogenic differentiation. Fluoxetine significantly decreased ASC proliferation, and signal transduction PCR array analysis showed that it increased expression of autophagy-related genes. In addition, fluoxetine up-regulated SQSTM1 and LC3B protein expression as detected by western blotting and immunofluorescence. The autophagy inhibitor, 3-methyladenine (3-MA), significantly attenuated fluoxetine-mediated effects on ASC proliferation and SQSTM1/LC3B expression. In addition, 3-MA decreased the mRNA expression of two autophagy-related genes, beclin-1 and Atg7, in ASCs. Fluoxetine also significantly inhibited lipid accumulation and down-regulated the levels of PPAR-γ and C/EBP-α in ASCs. Collectively, these results indicate that fluoxetine decreases ASC proliferation and adipogenic differentiation. This is the first in vitro evidence that fluoxetine can reduce fat accumulation by inhibiting ASC proliferation and differentiation. PMID:26204837

Fluoxetine Decreases the Proliferation and Adipogenic Differentiation of Human Adipose-Derived Stem Cells.

PubMed

Sun, Bo Kyung; Kim, Ji Hye; Choi, Joon-Seok; Hwang, Sung-Joo; Sung, Jong-Hyuk

2015-07-22

Fluoxetine was originally developed as an antidepressant, but it has also been used to treat obesity. Although the anti-appetite effect of fluoxetine is well-documented, its potential effects on human adipose-derived stem cells (ASCs) or mature adipocytes have not been investigated. Therefore, we investigated the mechanisms underlying the inhibitory effects of fluoxetine on the proliferation of ASCs. We also investigated its inhibitory effect on adipogenic differentiation. Fluoxetine significantly decreased ASC proliferation, and signal transduction PCR array analysis showed that it increased expression of autophagy-related genes. In addition, fluoxetine up-regulated SQSTM1 and LC3B protein expression as detected by western blotting and immunofluorescence. The autophagy inhibitor, 3-methyladenine (3-MA), significantly attenuated fluoxetine-mediated effects on ASC proliferation and SQSTM1/LC3B expression. In addition, 3-MA decreased the mRNA expression of two autophagy-related genes, beclin-1 and Atg7, in ASCs. Fluoxetine also significantly inhibited lipid accumulation and down-regulated the levels of PPAR-γ and C/EBP-α in ASCs. Collectively, these results indicate that fluoxetine decreases ASC proliferation and adipogenic differentiation. This is the first in vitro evidence that fluoxetine can reduce fat accumulation by inhibiting ASC proliferation and differentiation.

1,8-cineole inhibits both proliferation and elongation of BY-2 cultured tobacco cells.

PubMed

Yoshimura, Hiroko; Sawai, Yu; Tamotsu, Satoshi; Sakai, Atsushi

2011-03-01

Volatile monoterpenes such as 1,8-cineole inhibit the growth of Brassica campestris seedlings in a dose-dependent manner, and the growth-inhibitory effects are more severe for roots than hypocotyls. The preferential inhibition of root growth may be explained if the compounds inhibit cell proliferation more severely than cell elongation because root growth requires both elongation and proliferation of the constituent cells, whereas hypocotyl growth depends exclusively on elongation of existing cells. In order to examine this possibility, BY-2 suspension-cultured tobacco (Nicotiana tabacum) cells were treated with 1,8-cineole, and the inhibitory effects on cell proliferation and on cell elongation were assessed quantitatively. Treatment with 1,8-cineole lowered both the mitotic index and elongation of the cells in a dose-dependent manner, and the half-maximal inhibitory concentration (IC₅₀) for cell elongation was lower than that for cell proliferation. Moreover, 1,8-cineole also inhibited starch synthesis, with IC₅₀ lower than that for cell proliferation. Thus, the inhibitory effects of 1,8-cineole were not specific to cell proliferation; rather, 1,8-cineole seemed inhibitory to a variety of physiological activities when it was in direct contact with target cells. Based on these results, possible mechanisms for the mode of action of 1,8-cineole and for its preferential inhibition on root growth are discussed.

AS160 controls eukaryotic cell cycle and proliferation by regulating the CDK inhibitor p21.

PubMed

Gongpan, Pianchou; Lu, Yanting; Wang, Fang; Xu, Yuhui; Xiong, Wenyong

2016-07-02

AS160 (TBC1D4) has been implicated in multiple biological processes. However, the role and the mechanism of action of AS160 in the regulation of cell proliferation remain unclear. In this study, we demonstrated that AS160 knockdown led to blunted cell proliferation in multiple cell types, including fibroblasts and cancer cells. The results of cell cycle analysis showed that these cells were arrested in the G1 phase. Intriguingly, this inhibition of cell proliferation and the cell cycle arrest caused by AS160 depletion were glucose independent. Moreover, AS160 silencing led to a marked upregulation of the expression of the cyclin-dependent kinase inhibitor p21. Furthermore, whereas AS160 overexpression resulted in p21 downregulation and rescued the arrested cell cycle in AS160-depeleted cells, p21 silencing rescued the inhibited cell cycle and proliferation in the cells. Thus, our results demonstrated that AS160 regulates glucose-independent eukaryotic cell proliferation through p21-dependent control of the cell cycle, and thereby revealed a molecular mechanism of AS160 modulation of cell cycle and proliferation that is of general physiological significance.

Mechanisms and kinetics of proliferation and fibrosis development in a mouse model of thyrocyte hyperplasia.

PubMed

Ciornei, Radu Tudor; Hong, So-Hee; Fang, Yujiang; Zhu, Ziwen; Braley-Mullen, Helen

2016-01-01

IFN-γ(-/-) NOD.H-2h4 mice develop autoimmune disease with extensive hyperplasia and proliferation of thyroid epithelial cells (TEC H/P) and fibrosis. Splenic T cells from donors with severe TEC H/P transfer TEC H/P to SCID recipients. The goal of this study was to determine what factors control TEC H/P development/progression by examining T cells, markers of apoptosis, senescence and proliferation in thyroids of SCID recipients over time. At 28days, T cell infiltration was maximal, thyrocytes were proliferating, and fibrosis was moderate. At days 60 and 90, thyroids were larger with more fibrosis. T cells, cytokines and thyrocyte proliferation decreased, and cell cycle inhibitor proteins, and anti-apoptotic molecules increased. T cells and thyrocytes had foci of phosphorylated histone protein H2A.X, indicative of cellular senescence, when TEC H/P progressed and thyrocyte proliferation declined. Some thyrocytes were regenerating at day 90, with irregularly shaped empty follicles and ciliated epithelium. Proliferating thyrocytes were thyroid transcription factor (TTF1)-positive, suggesting they derived from epithelial cells and not brachial cleft remnants. Copyright © 2016 Elsevier Inc. All rights reserved.

RELM-β promotes human pulmonary artery smooth muscle cell proliferation via FAK-stimulated surviving

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

Lin, Chunlong, E-mail: lclmd@sina.com; Li, Xiaohui; Luo, Qiong

Resistin-like molecule-β (RELM-β), focal adhesion kinase (FAK), and survivin may be involved in the proliferation of cultured human pulmonary artery smooth muscle cells (HPAMSCs), which is involved in pulmonary hypertension. HPAMSCs were treated with human recombinant RELM-β (rhRELM-β). siRNAs against FAK and survivin were transfected into cultured HPASMCs. Expression of FAK and survivin were examined by RT-PCR and western blot. Immunofluorescence was used to localize FAK. Flow cytometry was used to examine cell cycle distribution and cell death. Compared to the control group, all rhRELM-β-treated groups demonstrated significant increases in the expression of FAK and survivin (P<0.05). rhRELM-β significantly increasedmore » the proportion of HPASMCs in the S phase and decreased the proportion in G0/G1. FAK siRNA down-regulated survivin expression while survivin siRNA did not affect FAK expression. FAK siRNA effectively inhibited FAK and survivin expression in RELM-β-treated HPASMCs and partially suppressed cell proliferation. RELM-β promoted HPASMC proliferation and upregulated FAK and survivin expression. In conclusion, results suggested that FAK is upstream of survivin in the signaling pathway mediating cell proliferation. FAK seems to be important in RELM-β-induced HPASMC proliferation, partially by upregulating survivin expression. - Highlights: • rhRELM-β increased the expression of FAK and survivin. • rhRELM-β increased the proportion of HPASMCs in the S phase. • FAK is upstream of survivin in the signaling pathway mediating cell proliferation. • FAK is important in RELM-β-induced HPASMC proliferation, partly via survivin.« less

The selection of light emitting diode irradiation parameters for stimulation of human mesenchymal stem cells proliferation

NASA Astrophysics Data System (ADS)

Lewandowski, Rafał; Trafny, ElŻbieta A.; Stepińska, Małgorzata; Gietka, Andrzej; Kotowski, Paweł; Dobrzyńska, Monika; Łapiński, Mariusz P.

2016-12-01

Human mesenchymal stem cells (hMSCs) with their vast differentiation potential are very useful for cell-based regenerative medicine. To achieve sufficient numbers of cells for tissue engineering, many different methods have been used to reach the effective increase of cell proliferation. Low-energy red light provided by light emitting diodes (LEDs) have been recently introduced as a method that promoted biomodulation and proliferation of hMSCs in vitro. The purpose of this study was to find the optimum stimulatory dosimetric parameters of LED (630 nm) irradiation on the hMSCs proliferation. The energy density was 2, 3, 4, 10, 20 J/cm2 and the power density used was 7, 17 or 30 mW/cm2. Human MSCs were irradiated with single or triple exposures daily at room temperature and the cell proliferation rate was evaluated during nine days after irradiation. The results showed that after irradiation 4 J/cm2 and 17 mW/cm2 at a single dose the proliferation rate of hMSCs increased on day 5 and 9 (13% and 7%, respectively) when compared to nonirradiated cells. However, triple LED irradiation under the same parameters resulted in the decline in the cell proliferation rate on day 5, but the proliferation rate was at the same level on day 9, when compared with the cell proliferation after irradiation with a single dose. The effect of a single dose irradiation with 4 J/cm2 and 17 mW/cm2 on the proliferation of cells was the highest when the cells were irradiated in phosphate-buffered saline (PBS) instead of MSCGM culture medium.

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

IL-4 directly signals tissue-resident macrophages to proliferate beyond homeostatic levels controlled by CSF-1

PubMed Central

Ruckerl, Dominik; Thomas, Graham D.; Hewitson, James P.; Duncan, Sheelagh; Brombacher, Frank; Maizels, Rick M.; Hume, David A.; Allen, Judith E.

2013-01-01

Macrophages (MΦs) colonize tissues during inflammation in two distinct ways: recruitment of monocyte precursors and proliferation of resident cells. We recently revealed a major role for IL-4 in the proliferative expansion of resident MΦs during a Th2-biased tissue nematode infection. We now show that proliferation of MΦs during intestinal as well as tissue nematode infection is restricted to sites of IL-4 production and requires MΦ-intrinsic IL-4R signaling. However, both IL-4Rα–dependent and –independent mechanisms contributed to MΦ proliferation during nematode infections. IL-4R–independent proliferation was controlled by a rise in local CSF-1 levels, but IL-4Rα expression conferred a competitive advantage with higher and more sustained proliferation and increased accumulation of IL-4Rα+ compared with IL-4Rα− cells. Mechanistically, this occurred by conversion of IL-4Rα+ MΦs from a CSF-1–dependent to –independent program of proliferation. Thus, IL-4 increases the relative density of tissue MΦs by overcoming the constraints mediated by the availability of CSF-1. Finally, although both elevated CSF1R and IL-4Rα signaling triggered proliferation above homeostatic levels, only CSF-1 led to the recruitment of monocytes and neutrophils. Thus, the IL-4 pathway of proliferation may have developed as an alternative to CSF-1 to increase resident MΦ numbers without coincident monocyte recruitment. PMID:24101381

IL-4 directly signals tissue-resident macrophages to proliferate beyond homeostatic levels controlled by CSF-1.

PubMed

Jenkins, Stephen J; Ruckerl, Dominik; Thomas, Graham D; Hewitson, James P; Duncan, Sheelagh; Brombacher, Frank; Maizels, Rick M; Hume, David A; Allen, Judith E

2013-10-21

Macrophages (MΦs) colonize tissues during inflammation in two distinct ways: recruitment of monocyte precursors and proliferation of resident cells. We recently revealed a major role for IL-4 in the proliferative expansion of resident MΦs during a Th2-biased tissue nematode infection. We now show that proliferation of MΦs during intestinal as well as tissue nematode infection is restricted to sites of IL-4 production and requires MΦ-intrinsic IL-4R signaling. However, both IL-4Rα-dependent and -independent mechanisms contributed to MΦ proliferation during nematode infections. IL-4R-independent proliferation was controlled by a rise in local CSF-1 levels, but IL-4Rα expression conferred a competitive advantage with higher and more sustained proliferation and increased accumulation of IL-4Rα(+) compared with IL-4Rα(-) cells. Mechanistically, this occurred by conversion of IL-4Rα(+) MΦs from a CSF-1-dependent to -independent program of proliferation. Thus, IL-4 increases the relative density of tissue MΦs by overcoming the constraints mediated by the availability of CSF-1. Finally, although both elevated CSF1R and IL-4Rα signaling triggered proliferation above homeostatic levels, only CSF-1 led to the recruitment of monocytes and neutrophils. Thus, the IL-4 pathway of proliferation may have developed as an alternative to CSF-1 to increase resident MΦ numbers without coincident monocyte recruitment.

Differential regulation of cell proliferation in neurogenic zones in mice lacking cystine transport by xCT

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

Liu, Richard R.; Brown, Craig E.; Brain Research Center, University of British Columbia, Vancouver, BC, V6T 1Z3

2007-12-21

The cystine/glutamate exchanger (xCT) supplies intracellular cyst(e)ine for the production of glutathione, a major cellular anti-oxidant. xCT is enriched in brain regions associated with neurogenesis. Previous studies have shown that the malfunction of this protein greatly attenuates cell proliferation in vitro and is associated with brain atrophy in vivo. Using mice that are homozygous for a function-blocking deletion in xCT (Sut mice), we examined in vivo the role of xCT in cell proliferation in neurogenic regions of the subventricular zone (SVZ) and denate gyrus (DG) in the adult brain. Our results indicate that a high level of cellular proliferation inmore » the adult brain persists even in the absence of functional xCT. Furthermore, in both young adult and middle-aged mice (3 and 11 months old), rates of SVZ cell proliferation were comparable between Sut and wild-type controls, although there was trend towards reduced proliferation in Sut mice (12% and 9% reduction, respectively). To our surprise, rates of cell proliferation in the DG were elevated in both 3- and 11-month-old Sut mice relative to controls (22% and 28% increase, respectively). These results demonstrate that xCT expression plays a role in regulating cellular proliferation in the DG, but not the SVZ of adult mice. Furthermore, unlike previous in vitro studies, our in vivo observations clearly indicate that xCT is not essential for ongoing cellular proliferation.« less

Non-woven PGA/PVA fibrous mesh as an appropriate scaffold for chondrocyte proliferation.

PubMed

Rampichová, M; Koštáková, E; Filová, E; Prosecká, E; Plencner, M; Ocheretná, L; Lytvynets, A; Lukáš, D; Amler, E

2010-01-01

Non-woven textile mesh from polyglycolic acid (PGA) was found as a proper material for chondrocyte adhesion but worse for their proliferation. Neither hyaluronic acid nor chitosan nor polyvinyl alcohol (PVA) increased chondrocyte adhesion. However, chondrocyte proliferation suffered from acidic byproducts of PGA degradation. However, the addition of PVA and/or chitosan into a wet-laid non-woven textile mesh from PGA improved chondrocyte proliferation seeded in vitro on the PGA-based composite scaffold namely due to a diminished acidification of their microenvironment. This PVA/PGA composite mesh used in combination with a proper hydrogel minimized the negative effect of PGA degradation without dropping positive parameters of the PGA wet-laid non-woven textile mesh. In fact, presence of PVA and/or chitosan in the PGA-based wet-laid non-woven textile mesh even advanced the PGA-based wet-laid non-woven textile mesh for chondrocyte seeding and artificial cartilage production due to a positive effect of PVA in such a scaffold on chondrocyte proliferation.

Understanding the Warburg effect: the metabolic requirements of cell proliferation.

PubMed

Vander Heiden, Matthew G; Cantley, Lewis C; Thompson, Craig B

2009-05-22

In contrast to normal differentiated cells, which rely primarily on mitochondrial oxidative phosphorylation to generate the energy needed for cellular processes, most cancer cells instead rely on aerobic glycolysis, a phenomenon termed "the Warburg effect." Aerobic glycolysis is an inefficient way to generate adenosine 5'-triphosphate (ATP), however, and the advantage it confers to cancer cells has been unclear. Here we propose that the metabolism of cancer cells, and indeed all proliferating cells, is adapted to facilitate the uptake and incorporation of nutrients into the biomass (e.g., nucleotides, amino acids, and lipids) needed to produce a new cell. Supporting this idea are recent studies showing that (i) several signaling pathways implicated in cell proliferation also regulate metabolic pathways that incorporate nutrients into biomass; and that (ii) certain cancer-associated mutations enable cancer cells to acquire and metabolize nutrients in a manner conducive to proliferation rather than efficient ATP production. A better understanding of the mechanistic links between cellular metabolism and growth control may ultimately lead to better treatments for human cancer.

Recurrent proliferating trichilemmal tumor of the vulva: a case report.

PubMed

Moraloğlu, Özlem; Güngör, Tayfun; Ozyer, Sebnem; Eryilmaz, Özlem Gün; Özdener, Tülin; Toğrul, Cihan; Bayramoğlu, Hatice

2013-01-01

Proliferating trichilemmal tumor (PTT) is a rare but morphologically distinct tumor that usually arises on the scalp of elderly women. It is composed of multiple cysts consisting of squamous epithelium with trichilemmal keratinization without granular layer interposition. Vulvar proliferating trichilemmal cyst is very rare, with, to the best of our knowledge, only 3 cases previously reported in the literature. We describe a 39-year-old woman with recurrent PTT on the left labium majus of the vulva, which had been excised from the same side 5 years before. She had a palpable nodule, approximately 2 cm in size, which was firm, mobile, and nontender; without erythema and ulceration; and covered by normal skin on the vulva. There was no inguinal lymphadenopathy. The lesion was removed by wide surgical excision; because of the tissue elasticity, primary closure was possible. The pathology result was reported as proliferating trichilemmal carcinoma with tumor-free margins. Although local recurrence after wide excision is rare, we recommend complete excision for treatment of PTT and long-term follow-up because of the possibility of recurrence.

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.

Evaluation of proliferation potential in thyroid normo-/hypofunctioning and hyperfunctioning nodules.

PubMed

Cornianu, Marioara; Stan, V; Lazăr, Elena; Dema, Alis; Golu, Ioana; Tăban, Sorina; Vlad, Mihaela; Faur, Alexandra; Vărcuş, F; Babău, F

2011-01-01

Thyroid follicular adenomas (FA) and adenomatous thyroid nodules (AN) - lesions that are frequently found in areas with iodine deficiency, can be normo-/hypofunctioning (scintigraphically cold - SCN) or hyperfunctioning (scintigraphically hot - SHN) nodules. Evaluation of proliferation potential in thyroid nodules on tissue samples obtained at surgery from euthyroid patients clinically diagnosed with SCN and from patients with thyroid hyperfunction and SHN. We investigated the proliferation activity estimated by assessing PCNA and Ki-67 proliferation markers in 20 SCN (eight FA and 12 AN) and 16 toxic nodules (six hyperfunctioning FA and 10 toxic multinodular goiters), on formalin-fixed and paraffin-embedded tissue samples, 4-5 μm thick; we used the immunohistochemical technique in LSAB system (DAB visualization) with anti-PCNA (PC10) and anti-Ki-67 (MIB-1) monoclonal antibodies. For each case, we calculated the proliferation index PI-PCNA and PI-Ki-67. The dates were statistically evaluated using the t-unpaired test. We observed a higher PI-PCNA in thyroid nodules than in the normal surrounding thyroid tissue, with statistically significant values for FA (14.3% vs. 3.8%; p<0.029) and also for AN (8.36% vs. 1.24%; p<0.001). The mean PI-Ki-67 in nodules vs. surrounding thyroid tissue was 1.64% vs. 1.10% in FA (p<0.35) and 1.07% vs. 0.51% in AN (p>0.05). We also noted: (1) significantly higher PI-PCNA values (p < 0.01) in FA (14.03%) than in AN (8.36%), as compared to statistically insignificant values for Ki-67 (1.64% vs. 1.07%; p>0.05); (2) increased proliferation rate (p<0.01) in thyroid nodules with aspects of lymphocytic thyroiditis (LT) (PI-Ki-67 was 1.21%) as compared to nodules without LT (PI-Ki-67 was 0.12%); (3) a mean PI-PCNA of 8.5% and PI-Ki-67 of 4.61% in toxic thyroid nodules (TTN) vs. 3.01% and 1.5% in normal surrounding thyroid, respectively. The clinical expression of SCN is the consequence of increased thyrocyte proliferation in the nodules; the

Promotion of stem cell proliferation by vegetable peptone.

PubMed

Lee, J; Lee, J; Hwang, H; Jung, E; Huh, S; Hyun, J; Park, D

2009-10-01

Technical limitations and evolution of therapeutic applications for cell culture-derived products have accelerated elimination of animal-derived constituents from such products to minimize inadvertent introduction of microbial contaminants, such as fungi, bacteria or viruses. The study described here was conducted to investigate the proliferative effect of vegetable peptone on adult stem cells in the absence of serum, and its possible mechanisms of action. Cell viability and proliferation were determined using the MTT assay and Click-iT EdU flow cytometry, respectively. In addition, changes in expression of cytokine genes were analysed using MILLIPLEX human cytokine enzyme-linked immunosorbent assay kit. Viability of cord blood-derived mesenchymal stem cells (CB-MSC) and adipose tissue-derived stem cells (ADSC) increased significantly when treated with the peptone. In addition, median value of the group treated with peptone shifted to the right when compared to the untreated control group. Furthermore, quantitative analysis of the cytokines revealed that production of vascular endothelial growth factor (VEGF), transforming growth factor-beta1 (TGF-beta1), and interleukin-6 (IL-6) increased significantly in response to treatment with our vegetable peptone in both CB-MSCs and ADSCs. Our findings revealed that the vegetable peptone promotes proliferation of CB-MSCs and ADSCs. In addition, results of this study suggest that induction of stem cell proliferation by vegetable peptone is likely to be related to its induction of VEGF, TGF-beta1, and IL-6 expression.

MicroRNAs control hepatocyte proliferation during liver regeneration.

PubMed

Song, Guisheng; Sharma, Amar Deep; Roll, Garrett R; Ng, Raymond; Lee, Andrew Y; Blelloch, Robert H; Frandsen, Niels M; Willenbring, Holger

2010-05-01

MicroRNAs (miRNAs) constitute a new class of regulators of gene expression. Among other actions, miRNAs have been shown to control cell proliferation in development and cancer. However, whether miRNAs regulate hepatocyte proliferation during liver regeneration is unknown. We addressed this question by performing 2/3 partial hepatectomy (2/3 PH) on mice with hepatocyte-specific inactivation of DiGeorge syndrome critical region gene 8 (DGCR8), an essential component of the miRNA processing pathway. Hepatocytes of these mice were miRNA-deficient and exhibited a delay in cell cycle progression involving the G(1) to S phase transition. Examination of livers of wildtype mice after 2/3 PH revealed differential expression of a subset of miRNAs, notably an induction of miR-21 and repression of miR-378. We further discovered that miR-21 directly inhibits Btg2, a cell cycle inhibitor that prevents activation of forkhead box M1 (FoxM1), which is essential for DNA synthesis in hepatocytes after 2/3 PH. In addition, we found that miR-378 directly inhibits ornithine decarboxylase (Odc1), which is known to promote DNA synthesis in hepatocytes after 2/3 PH. Our results show that miRNAs are critical regulators of hepatocyte proliferation during liver regeneration. Because these miRNAs and target gene interactions are conserved, our findings may also be relevant to human liver regeneration.

Agmatine inhibits chronic morphine exposure-induced impairment of hippocampal neural progenitor proliferation in adult rats.

PubMed

Liu, Ying; Lu, Guan-Yi; Chen, Wen-Qiang; Li, Yun-Feng; Wu, Ning; Li, Jin

2018-01-05

Our previous studies have shown that agmatine inhibited opioid dependence, yet the neural mechanism remains unclear. Growing evidence showed that opioids decrease neurogenesis in the adult hippocampal subgranular zone by inhibiting neural progenitor proliferation. However, whether agmatine affects chronic opioid exposure-induced impairment to hippocampal neural progenitor cell proliferation remains unknown. In the present study, we investigated the role of agmatine in hippocampal neural progenitors in morphine dependence rats. We found that chronic administration of morphine for 12 days induced morphine dependence in rats. This treatment not only decreased the proliferation of hippocampal neural progenitors in the granule cell layer, but also decreased the levels of hippocampal cAMP, pCREB and BDNF. However, these alterations can be restored to normal levels by co-treatment of agmatine (10mg/kg, s.c.). In vitro treatment with agmatine (10µM) for two days significantly increased proliferation of the cultured hippocampal neural progenitors. Concurrent treatment of agmatine (10µM) with morphine (10 or 50µM) reversed the supression of morphine-induced neural progenitor proliferation. In conclusion, we found that agmatine abolished chronic morphine-induced decrease in proliferation of hippocampal progenitors in vivo and in vitro, which may be due to the increase in cAMP-CREB-BDNF signaling. The enhancement of agmatine to proliferation of hippocampal progenitors may be one of the important mechanisms involved in the inhibition of morphine dependence by agmatine. Copyright © 2017. Published by Elsevier B.V.

miR-367 promotes proliferation and invasion of hepatocellular carcinoma cells by negatively regulating PTEN

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

Meng, Xiangrui, E-mail: mengxiangruibb2008@163.com; Lu, Peng; Fan, Qingxia

2016-01-29

MicroRNAs play important roles in the carcinogenesis of many types of cancers by inhibiting gene expression at posttranscriptional level. However, the roles of microRNAs in hepatocellular carcinoma, are still unclear. Here, we identified that miR-367 promotes hepatocellular carcinoma (HCC) cell proliferation by negatively regulates its target gene PTEN. The expression of miR-367 and PTEN are significantly inverse correlated in 35 HCC patients. In HCC cell line, CCK-8 proliferation assay indicated that the cell proliferation was promoted by miR-367, while miR-367 inhibitor significantly inhibited the cell proliferation. Transwell assay showed that miR-367 mimics significantly promoted the migration and invasion of HCCmore » cells, whereas miR-367 inhibitors significantly reduced cell migration and invasion. Luciferase assays confirmed that miR-367 directly bound to the 3'untranslated region of PTEN, and western blotting showed that miR-367 suppressed the expression of PTEN at the protein levels. This study indicated that miR-367 negatively regulates PTEN and promotes proliferation and invasion of HCC cells. Thus, miR-367 may represent a potential therapeutic target for HCC intervention. - Highlights: • miR-367 mimics promote the proliferation and invasion of HCC cells. • miR-367 inhibitors inhibit the proliferation and invasion of HCC cells. • miR-367 targets 3′UTR of PTEN in HCC cells. • miR-367 negatively regulates PTEN in HCC cells.« less

Commercial Satellite Imagery Analysis for Countering Nuclear Proliferation

NASA Astrophysics Data System (ADS)

Albright, David; Burkhard, Sarah; Lach, Allison

2018-05-01

High-resolution commercial satellite imagery from a growing number of private satellite companies allows nongovernmental analysts to better understand secret or opaque nuclear programs of countries in unstable or tense regions, called proliferant states. They include North Korea, Iran, India, Pakistan, and Israel. By using imagery to make these countries’ aims and capabilities more transparent, nongovernmental groups like the Institute for Science and International Security have affected the policies of governments and the course of public debate. Satellite imagery work has also strengthened the efforts of the International Atomic Energy Agency, thereby helping this key international agency build its case to mount inspections of suspect sites and activities. This work has improved assessments of the nuclear capabilities of proliferant states. Several case studies provide insight into the use of commercial satellite imagery as a key tool to educate policy makers and affect policy.

The Role of Spatially Controlled Cell Proliferation in Limb Bud Morphogenesis

PubMed Central

Boehm, Bernd; Westerberg, Henrik; Lesnicar-Pucko, Gaja; Raja, Sahdia; Rautschka, Michael; Cotterell, James; Swoger, Jim; Sharpe, James

2010-01-01

Although the vertebrate limb bud has been studied for decades as a model system for spatial pattern formation and cell specification, the cellular basis of its distally oriented elongation has been a relatively neglected topic by comparison. The conventional view is that a gradient of isotropic proliferation exists along the limb, with high proliferation rates at the distal tip and lower rates towards the body, and that this gradient is the driving force behind outgrowth. Here we test this hypothesis by combining quantitative empirical data sets with computer modelling to assess the potential role of spatially controlled proliferation rates in the process of directional limb bud outgrowth. In particular, we generate two new empirical data sets for the mouse hind limb—a numerical description of shape change and a quantitative 3D map of cell cycle times—and combine these with a new 3D finite element model of tissue growth. By developing a parameter optimization approach (which explores spatial patterns of tissue growth) our computer simulations reveal that the observed distribution of proliferation rates plays no significant role in controlling the distally extending limb shape, and suggests that directional cell activities are likely to be the driving force behind limb bud outgrowth. This theoretical prediction prompted us to search for evidence of directional cell orientations in the limb bud mesenchyme, and we thus discovered a striking highly branched and extended cell shape composed of dynamically extending and retracting filopodia, a distally oriented bias in Golgi position, and also a bias in the orientation of cell division. We therefore provide both theoretical and empirical evidence that limb bud elongation is achieved by directional cell activities, rather than a PD gradient of proliferation rates. PMID:20644711

Mesenchymal stem cells do not suppress lymphoblastic leukemic cell line proliferation.

PubMed

Mousavi Niri, Neda; Jaberipour, Mansooreh; Razmkhah, Mahboobeh; Ghaderi, Abbas; Habibagahi, Mojtaba

2009-12-01

Several studies have demonstrated the immunosuppresive effects of mesenchymal stem cells (MSCs) in allogeneic or mitogenic interactions. Cell-cell contact inhibition and secretion of suppressive soluble factors have been suggested in this regard. To investigate if adipose derived MSCs could inhibit Jurkat lymphoblastic leukemia T cell proliferation during coculture. Adherent cells with the ability of cellular growth were isolated from normal adipose tissues. Initial characterization of growing cells by flow cytometry suggested their mesenchymal stem cell characteristics. Cells were maintained in culture and used during third to fifth culture passages. Jurkat or allogeneic peripheral blood mononuclear cells (PBMCs) were labeled with carboxy fluorescein diacetate succinimidyl ester and cocultured with increasing doses of MSCs or MSC culture supernatant. Proliferation of PBMCs or Jurkat cells under these conditions was assessed by flow cytometry after 2 and 3 days of coculture, respectively. Results showed the expression of CD105, CD166 and CD44, and the absence of CD45, CD34 and CD14 on the surface of MSC like cells. Moreover, initial differentiation studies showed the potential of cell differentiation into hepatocytes. Comparison of Jurkat cell proliferation in the presence and absence of MSCs showed no significant difference, with 70% of cells displaying signs of at least one cell division. Similarly, the highest concentration of MSC culture supernatant (50% vol/vol) had no significant effect on Jurkat cell proliferation (p>0.6). The same MSC lots significantly suppressed the allogeneic PHA activated PBMCs under similar culture conditions. Using Jurkat cells as a model of leukemia T cells, our results indicated an uncertainty about the suppressive effect of MSCs and their inhibitory metabolites on tumor or leukemia cell proliferation. Additional systematic studies with MSCs of different sources are needed to fully characterize the immunological properties of MSCs

ERβ inhibits proliferation and invasion of breast cancer cells

PubMed Central

Lazennec, Gwendal; Bresson, Damien; Lucas, Annick; Chauveau, Corine; Vignon, Françoise

2001-01-01

Recent studies indicate that the expression of ERβ in breast cancer is lower than in normal breast, suggesting that ERβ could play an important role in carcinogenesis. To investigate this hypothesis, we engineered estrogen-receptor negative MDA-MB-231 breast cancer cells to reintroduce either ERα or ERβ protein with an adenoviral vector. In these cells, ERβ (as ERα) expression was monitored using RT-PCR and Western blot. ERβ protein was localized in the nucleus (immunocytochemistry) and able to transactivate estrogen-responsive reporter constructs in the presence of estradiol. ERβ and ERα induced the expression of several endogenous genes such as pS2, TGFα or the cyclin kinase inhibitor p21, but in contrast to ERα, ERβ was unable to regulate c-myc proto-oncogene expression. The pure antiestrogen ICI 164, 384 completely blocked ERα and ERβ estrogen-induced activities. ERβ inhibited MDA-MB-231 cell proliferation in a ligand-independent manner, whereas ERα inhibition of proliferation is hormone-dependent. Moreover, ERβ and ERα, decreased cell motility and invasion. Our data bring the first evidence that ERβ is an important modulator of proliferation and invasion of breast cancer cells and support the hypothesis that the loss of ERβ expression could be one of the events leading to the development of breast cancer. PMID:11517191

Squamous cell carcinoma of the lung with highly proliferating fibromatosis-like stroma: a rare phenomenon.

PubMed

Tajima, Shogo; Takanashi, Yusuke; Koda, Kenji

2015-01-01

Few cases of carcinoma with exuberant stromal proliferation have been documented, apart from scirrhous carcinoma. To the best of our knowledge, previous cases of carcinoma exhibiting exuberant stromal proliferation have exclusively been reported in the thyroid gland, specifically as papillary carcinoma. The exuberant stromal proliferation has been recognized to be similar to either fibromatosis or nodular fasciitis. Herein, we report a case of a 74-year-old Japanese man whose tumor in the upper lobe of his right lung displayed highly proliferating stroma with dispersed, poorly differentiated squamous cell carcinoma nests. The stromal spindle cells (fibroblasts/myofibroblasts) had similar molecular profiles to those typically observed in fibromatosis rather than nodular fasciitis, resulting in the designation of "fibromatosis-like" stroma. The presence of carcinoma cells, along with stromal cells, expressing TGF-β in this case likely fostered continuous stromal proliferation, presumably in conjunction with the unique microenvironment in which the carcinoma cells were present.

Lidocaine inhibits the proliferation of lung cancer by regulating the expression of GOLT1A.

PubMed

Zhang, Lei; Hu, Rong; Cheng, Yanyong; Wu, Xiaoyang; Xi, Siwei; Sun, Yu; Jiang, Hong

2017-10-01

Lidocaine is the most commonly used local anaesthetic in clinical and can inhibit proliferation, suppress invasion and migration and induce apoptosis in human lung adenocarcinoma (LAD) cells. However, its specific downstream molecular mechanism is unclear. LAD cell lines, A549 and H1299 cells, were treated with lidocaine. The proliferation was evaluated by the methylthiazolyldiphenyl-tetrazolium bromide (MTT) and bromodeoxyuridine (BrdU) assay. The expression level of related proteins was detected by real-time quantitative PCR (qPCR) and Western blot assay. The results indicated that lidocaine dose-dependently suppressed the proliferation of A549 and H1299 cells. In the LAD patients' samples, GOLT1A was upregulated and involved in the poor prognosis and higher grade malignancy. Additionally, GOLT1A mediates the function of lidocaine on repressing proliferation by regulating the cell cycle in A549 cells. Our findings suggest that lidocaine downregulates the GOLT1A expression to repress the proliferation of lung cancer cells. © 2017 John Wiley & Sons Ltd.

Inosine Released from Dying or Dead Cells Stimulates Cell Proliferation via Adenosine Receptors.

PubMed

Chen, Jin; Chaurio, Ricardo A; Maueröder, Christian; Derer, Anja; Rauh, Manfred; Kost, Andriy; Liu, Yi; Mo, Xianming; Hueber, Axel; Bilyy, Rostyslav; Herrmann, Martin; Zhao, Yi; Muñoz, Luis E

2017-01-01

Many antitumor therapies induce apoptotic cell death in order to cause tumor regression. Paradoxically, apoptotic cells are also known to promote wound healing, cell proliferation, and tumor cell repopulation in multicellular organisms. We aimed to characterize the nature of the regenerative signals concentrated in the micromilieu of dead and dying cells. Cultures of viable melanoma B16F10 cells, mouse fibroblasts, and primary human fibroblast-like synoviocytes (FLS) in the presence of dead and dying cells, their supernatants (SNs), or purified agonists and antagonists were used to evaluate the stimulation of proliferation. Viable cell quantification was performed by either flow cytometry of harvested cells or by crystal violet staining of adherent cells. High-performance liquid chromatography and liquid chromatography coupled with mass spectrometry of cell SNs were deployed to identify the nature of growth-promoting factors. Coimplantation of living cells in the presence of SNs collected from dead and dying cells and specific agonists was used to evaluate tumor growth in vivo . The stimulation of proliferation of few surviving cells by bystander dead cells was confirmed for melanoma cells, mouse fibroblasts, and primary FLS. We found that small soluble molecules present in the protein-free fraction of SNs of dead and dying cells were responsible for the promotion of proliferation. The nucleoside inosine released by dead and dying cells acting via adenosine receptors was identified as putative inducer of proliferation of surviving tumor cells after irradiation and heat treatment. Inosine released by dead and dying cells mediates tumor cell proliferation via purinergic receptors. Therapeutic strategies surmounting this pathway may help to reduce the rate of recurrence after radio- and chemotherapy.

Drivers of tall shrub proliferation adjacent to the Dempster Highway, Northwest Territories, Canada

NASA Astrophysics Data System (ADS)

Cameron, Emily A.; Lantz, Trevor C.

2016-04-01

Arctic ecosystems are undergoing rapid changes as a result of climate warming and more frequent disturbances. Disturbances can have particularly large effects on high-latitude ecosystems when ecosystem structure and function is controlled by strong feedbacks between soil conditions, vegetation, and ground thermal regime. In this study we investigated the impact of road construction and maintenance on vegetation structure and biomass along the Dempster Highway where it crosses the Peel Plateau in the Northwest Territories. To explore drivers of tall shrub proliferation and to quantify shrub proliferation in this region of continuous permafrost, greyscale air photos (1975) and Quickbird satellite imagery (2008) were used to map landcover change within two 0.6 km2 belts next to the road and two 0.6 km2 belts 500 m away from the road. Maps showing areas where: 1) tall shrubs expanded, and 2) dwarf shrub tundra resisted invasion were then used to select field sites where a suite of biophysical variables were measured. Rapid tall shrub proliferation and greater biomass adjacent to the road indicate that disturbance can facilitate vegetation change in tundra environments. Our field data also suggests that increased shrub proliferation adjacent to the road was caused by greater soil moisture. Tall shrub proliferation adjacent to the road occurred at lower elevation sites characterized by wetter soils with thicker organic layers. Areas that resisted tall shrub encroachment were located at higher elevations and had drier soils with thin organic layers. Our observations also support previous work illustrating that tall shrub expansion next to the highway promotes strong positive feedbacks to ongoing shrub growth and proliferation.

Photobiostimulation on chondrocytes proliferation in different concentration of fetal bovine serum under low-level laser irradiation

NASA Astrophysics Data System (ADS)

Zheng, Liqin; Wang, Yuhua; Qiu, Caimin; Chen, Jianlin; Yang, Hongqin; Zhang, Yanding; Xie, Shusen

2015-03-01

The aim of this in vitro study was to evaluate the influence of low-level laser irradiation (LLLI) on the chondrocytes proliferation cultured in different concentration of fetal bovine serum (FBS) using 658 nm, 785 nm and 830 nm diode lasers. The role of energy density (10-70 mJ·cm-2) on chondrocytes proliferation following irradiation with 658 nm laser for 2 days was firstly investigated to find out the best laser energy density. Then the effect of LLLI on the proliferation of chondrocytes cultured with fetal bovine serum at 0%, 2%, 5% and 10% was also evaluated. The results showed that there was no or little photobiostimulation on the proliferation of chondrocytes cultured with 0% FBS and 10% FBS; the cell proliferation at 2% and 5% FBS was significantly modulated by LLLI.

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

Whole organism high content screening identifies stimulators of pancreatic beta-cell proliferation.

PubMed

Tsuji, Naoki; Ninov, Nikolay; Delawary, Mina; Osman, Sahar; Roh, Alex S; Gut, Philipp; Stainier, Didier Y R

2014-01-01

Inducing beta-cell mass expansion in diabetic patients with the aim to restore glucose homeostasis is a promising therapeutic strategy. Although several in vitro studies have been carried out to identify modulators of beta-cell mass expansion, restoring endogenous beta-cell mass in vivo has yet to be achieved. To identify potential stimulators of beta-cell replication in vivo, we established transgenic zebrafish lines that monitor and allow the quantification of cell proliferation by using the fluorescent ubiquitylation-based cell cycle indicator (FUCCI) technology. Using these new reagents, we performed an unbiased chemical screen, and identified 20 small molecules that markedly increased beta-cell proliferation in vivo. Importantly, these structurally distinct molecules, which include clinically-approved drugs, modulate three specific signaling pathways: serotonin, retinoic acid and glucocorticoids, showing the high sensitivity and robustness of our screen. Notably, two drug classes, retinoic acid and glucocorticoids, also promoted beta-cell regeneration after beta-cell ablation. Thus, this study establishes a proof of principle for a high-throughput small molecule-screen for beta-cell proliferation in vivo, and identified compounds that stimulate beta-cell proliferation and regeneration.

Development of Shuttle Vectors for Halobacteria

DTIC Science & Technology

1989-02-01

the time of application, we had completed a study of transfection, using Halobacterium halobiun and its phage ,DH. We showed (Cline and Doolittle... phage particles), producing plaques titratable on H. halobium lawns. Uptake of DNA by both species appears to be about equally efficient, but DNA from H...halobium-grown phage is restricted in H. volcanii, which shows a 104 - 105 reduction in transfection efficiency (400 plaques per pg) but no reduction

Simultaneous Increases in Proliferation and Apoptosis of Vascular Smooth Muscle Cells Accelerate Diabetic Mouse Venous Atherosclerosis

PubMed Central

Liu, Shuying; Zhang, Zhengyu; Wang, Jingjing; Zhou, Yuhuan; Liu, Kefeng; Huang, Jintao; Chen, Dadi; Wang, Junmei; Li, Chaohong

2015-01-01

Aims This study was designed to demonstrate simultaneous increases in proliferation and apoptosis of vascular smooth muscle cells (VSMCs) leading to accelerated vein graft remodeling and to explore the underlying mechanisms. Methods Vein grafts were performed in non-diabetic and diabetic mice. The cultured quiescent VSMCs were subjected to mechanical stretch stress (SS) and/or advanced glycosylation end products (AGEs). Harvested vein grafts and treated VSMCs were used to detect cell proliferation, apoptosis, mitogen-activated protein kinases (MAPKs) activation and SM-α-actin expression. Results Significantly thicker vessel walls and greater increases in proliferation and apoptosis were observed in diabetic vein grafts than those in non-diabetic. Both SS and AGEs were found to induce different activation of three members of MAPKs and simultaneous increases in proliferation and apoptosis of VSMCs, and combined treatment with both had a synergistic effect. VSMCs with strong SM-α-actin expression represented more activated JNKs or p38MAPK, and cell apoptosis, while the cells with weak SM-α-actin expression demonstrated preferential activation of ERKs and cell proliferation. In contrast, inhibition of MAPKs signals triggered significant decreases in VSMC proliferation, and apoptosis. Treatment of the cells with RNA interference of receptor of AGEs (RAGE) also resulted in significant decreases in both proliferation and apoptosis. Conclusions Increased pressure-induced SS triggers simultaneous increases in proliferation and apoptosis of VSMCs in the vein grafts leading to vein arterializations, which can be synergistically accelerated by high glucose-induced AGEs resulting in vein graft atherosclerosis. Either SS or AGEs and their combination induce simultaneous increases in proliferation and apoptosis of VSMCs via different activation of three members of MAPKs resulting from different VSMC subtypes classified by SM-α-actin expression levels. PMID:26488175

Adenylate kinase 2 (AK2) promotes cell proliferation in insect development

PubMed Central

2012-01-01

Background Adenylate kinase 2 (AK2) is a phosphotransferase that catalyzes the reversible reaction 2ADP(GDP) ↔ ATP(GTP) + AMP and influences cellular energy homeostasis. However, the role of AK2 in regulating cell proliferation remains unclear because AK2 has been reported to be involved in either cell proliferation or cell apoptosis in different cell types of various organisms. Results This study reports AK2 promotion of cell proliferation using the lepidopteran insect Helicoverpa armigera and its epidermal cell line HaEpi as models. Western blot analysis indicates that AK2 constitutively expresses in various tissues during larval development. Immunocytochemistry analysis indicates that AK2 localizes in the mitochondria. The recombinant expressed AK2 in E. coli promotes cell growth and viability of HaEpi cell line by 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. AK2 knockdown in larvae by RNA interference causes larval growth defects, including body weight decrease and development delay. AK2 knockdown in larvae also decreases the number of circulating haemocytes. The mechanism for such effects might be the suppression of gene transcription involved in insect development caused by AK2 knockdown. Conclusion These results show that AK2 regulates cell growth, viability, and proliferation in insect growth and development. PMID:23020757

Tenascin-C, proliferation and subendothelial fibronectin in progressive pulmonary vascular disease.

PubMed Central

Jones, P. L.; Cowan, K. N.; Rabinovitch, M.

1997-01-01

Progressive pulmonary hypertension is characterized by smooth muscle cell proliferation and migration leading to occlusive arterial lesions. Previously, using cultured smooth muscle cells, we demonstrated that epidermal growth factor (EGF)-dependent proliferation and migration are dependent on tenascin-C (Tn) and cellular fibronectin (Fn), respectively. In this study we applied immunohistochemistry to lung biopsy tissue from patients with congenital heart defects and pulmonary hypertension to determine how the distribution and intensity of Tn, EGF, proliferating cell nuclear antigen (PCNA), and Fn expression related to arterial abnormalities. With mildly increased wall thickness, minimal Tn, PCNA, and EGF was evident. With progressive hypertrophy, moderately intense foci of Tn were apparent in the adventitia, periendothelium, and occasionally the media but not consistently co-distributing with EGF and PCNA. With obstructive lesions, intense neointimal Tn expression co-localized with EGF and PCNA. Fn accumulation in the periendothelium increased with medial hypertrophy and became more widespread in a diffuse pattern with neointimal formation. The neointima was predominantly composed of alpha-smooth-muscle-actin-positive cells, occasional inflammatory cells with no evidence of apoptosis. These studies are consistent with Tn modulating EGF-dependent neointimal smooth muscle cell proliferation and Fn providing a gradient for smooth muscle cell migration from media to neointima. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 PMID:9094991

Liver damage, proliferation, and progenitor cell markers in experimental necrotizing enterocolitis.

PubMed

Miyake, Hiromu; Li, Bo; Lee, Carol; Koike, Yuhki; Chen, Yong; Seo, Shogo; Pierro, Agostino

2018-05-01

Necrotizing enterocolitis (NEC) is a disease known to cause injury to multiple organs including the liver. Liver regeneration is essential for the recovery after NEC-induced liver injury. Our aim was to investigate hepatic proliferation and progenitor cell marker expression in experimental NEC. Following ethical approval (#32238), NEC was induced in mice by hypoxia, gavage feeding of hyperosmolar formula, and lipopolysaccharide. Breastfed pups were used as control. We analyzed serum ALT level, liver inflammatory cytokines, liver proliferation markers, and progenitor cell marker expression. Comparison was made between NEC and controls. Serum ALT level was higher in NEC (p<0.05). The mRNA expression of inflammatory cytokines in the liver was also higher in NEC (IL6: p<0.05, TNF-α: p<0.01). Conversely, mRNA expression of proliferation markers in the liver was lower in NEC (Ki67; p<0.01, PCNA: p<0.01). LGR5 expression was also significantly decreased in NEC as demonstrated by mRNA (p<0.05) and protein (p<0.01) levels. Inflammatory injury was present in the liver during experimental NEC. Proliferation and LGR5 expression were impaired in the NEC liver. Modulation of progenitor cell expressing LGR5 may result in stimulation of liver regeneration in NEC-induced liver injury and improved clinical outcome. Level IV. Copyright © 2018. Published by Elsevier Inc.

Simultaneous Study of Mechanical Stretch-Induced Cell Proliferation and Apoptosis on C2C12 Myoblasts.

PubMed

Feng, Yu; Tian, Xiang-Yang; Sun, Peng; Cheng, Ze-Peng; Shi, Reng-Fei

2018-06-27

Mechanical stretch may cause myoblasts to either proliferate or undergo apoptosis. Identifying the molecular events that switch the fate of a stretched cell from proliferation to apoptosis is practically important in the field of regenerative medicine. A recent study on vascular smooth muscle cells illustrated that identification of these events may be achieved by addressing the stretch-induced opposite cellular outcomes simultaneously within a single investigation. To define conditions or a model in which both proliferation and apoptosis can be studied at the same time, we exposed in vitro cultured C2C12 myoblasts to a cyclic mechanical stretch regimen of 15% elongation at a stretching frequency of 1 Hz for 0, 2, 4, 6, or 8 h every day, consecutively, for 3 days. Both proliferation and apoptosis were observed. Moreover, as the duration of the stretch was prolonged, cell proliferation increased until it peaked at the optimal stretching duration. Afterwards, apoptosis gradually prevailed. Therefore, we established a model in which stretch-induced cell proliferation and apoptosis can be studied simultaneously. © 2018 S. Karger AG, Basel.

41 CFR 109-43.305-50 - Nuclear-related and proliferation-sensitive personal property.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 41 Public Contracts and Property Management 3 2014-01-01 2014-01-01 false Nuclear-related and proliferation-sensitive personal property. 109-43.305-50 Section 109-43.305-50 Public Contracts and Property... Excess § 109-43.305-50 Nuclear-related and proliferation-sensitive personal property. Nuclear-related and...

41 CFR 109-43.305-50 - Nuclear-related and proliferation-sensitive personal property.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 41 Public Contracts and Property Management 3 2011-01-01 2011-01-01 false Nuclear-related and proliferation-sensitive personal property. 109-43.305-50 Section 109-43.305-50 Public Contracts and Property... Excess § 109-43.305-50 Nuclear-related and proliferation-sensitive personal property. Nuclear-related and...

41 CFR 109-43.305-50 - Nuclear-related and proliferation-sensitive personal property.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 41 Public Contracts and Property Management 3 2013-07-01 2013-07-01 false Nuclear-related and proliferation-sensitive personal property. 109-43.305-50 Section 109-43.305-50 Public Contracts and Property... Excess § 109-43.305-50 Nuclear-related and proliferation-sensitive personal property. Nuclear-related and...

41 CFR 109-43.305-50 - Nuclear-related and proliferation-sensitive personal property.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 41 Public Contracts and Property Management 3 2012-01-01 2012-01-01 false Nuclear-related and proliferation-sensitive personal property. 109-43.305-50 Section 109-43.305-50 Public Contracts and Property... Excess § 109-43.305-50 Nuclear-related and proliferation-sensitive personal property. Nuclear-related and...

41 CFR 109-43.305-50 - Nuclear-related and proliferation-sensitive personal property.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false Nuclear-related and proliferation-sensitive personal property. 109-43.305-50 Section 109-43.305-50 Public Contracts and Property... Excess § 109-43.305-50 Nuclear-related and proliferation-sensitive personal property. Nuclear-related and...

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.

Tyrosine Kinase Inhibitor, Vatalanib, Inhibits Proliferation and Migration of Human Pterygial Fibroblasts.

PubMed

Kim, Hong Kyu; Choi, Ji-Young; Park, Sang Min; Rho, Chang Rae; Cho, Kyong Jin; Jo, Sangmee Ahn

2017-09-01

Vatalanib is a small-molecule tyrosine kinase inhibitor. We investigated the effects of vatalanib on the proliferation and migration of cultured human pterygial fibroblasts (HPFs). Pterygium tissues were obtained after pterygium excision surgery and subjected to primary culture. HPFs were treated with vatalanib at various concentrations. Mitomycin C (MMC) was used as a positive control. Cell proliferation and migration assays were used to investigate the effects of vatalanib. Cell death was measured using flow cytometry analysis. Western blot analysis was performed to identify signaling molecules associated with the response to vatalanib. Vatalanib inhibited both proliferation and migration of HPFs in a dose-dependent manner. Cell proliferation was significantly suppressed by vatalanib (10 and 100 μM) and MMC (0.004% and 0.04%) treatments. Migration assays revealed significant HPF delay when treated with vatalanib (1, 10, and 100 μM) and MMC (0.004% and 0.04%) compared with that in a negative control. Cell death analysis showed that high concentrations of vatalanib (100 μM) and MMC (0.004% and 0.04%) decreased cell numbers. Western blot analysis of vatalanib-treated cells showed vascular endothelial growth factor and transforming growth factor-β significantly reduced, but there was no alteration in p53 protein levels in HPFs. These results indicate that vatalanib significantly suppressed the proliferation and migration of HPFs by decreasing vascular endothelial growth factor and transforming growth factor-β. Vatalanib showed less toxicity than that of MMC. Based on these results, vatalanib may potentially serve as a new adjuvant treatment after pterygium excision surgery.

Inhibition of glycogen synthase kinase 3 increased subventricular zone stem cells proliferation.

PubMed

Pachenari, Narges; Kiani, Sahar; Javan, Mohammad

2017-09-01

The effects of Wnt signaling modifiers on cell proliferation, seem to be cell specific. Enhancing the proliferation of subventricular zone (SVZ) progenitors has been in the focus of research in recent years. Here we investigate the effect of CHIR99021, a Glycogen Synthase Kinase 3 (GSk-3) inhibitor, on SVZ progenitor's proliferation both in vivo and in vitro. Neural stem cells were extracted from the adult C57bl/6 by mincing and trypsin treatment followed by culturing in specific medium. Sphere cells formed within about 7-10days and were characterized by immunostaining. Number of spheres and their size was assessed following exposure to different concentration of CHIR99021 or vehicle. For in vivo studies, animals received intracerebroventricular (i.c.v.) injection of CHIR99021 or vehicle for four days. A subgroup of animals, after 4days treatment with CHIR99021 received intranasal kainic acid to induce local neurodegeneration in CA3 area of hippocampus. Inhibition of GSk-3 by CHIR99021 increased neural progenitor proliferation and the effect of CHIR99021 was long lasting so that the treated cells showed higher proliferation even after CHIR99021 removal. In vivo administration of CHIR99021 increased the number of neural progenitors at the rims of lateral ventricles especially when the treatment was followed by kainic acid administration which induces neural insult. Results showed that direct administration of CHIR99021 into the culture medium or animal brain increased the number of SVZ progenitors, especially when a neural insult was induced in the hippocampus. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Role of acetylcholine receptors in proliferation and differentiation of P19 embryonal carcinoma cells

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

Resende, R.R.; Alves, A.S.; Britto, L.R.G

2008-04-15

Coordinated proliferation and differentiation of progenitor cells is the base for production of appropriate numbers of neurons and glia during neuronal development in order to establish normal brain functions. We have used murine embryonal carcinoma P19 cells as an in vitro model for early differentiation to study participation of nicotinic (nAChR) and muscarinic acetylcholine (mAChR) receptors in the proliferation of neural progenitor cells and their differentiation to neurons. We have previously shown that functional nicotinic acetylcholine receptors (nAChRs) already expressed in embryonic cells mediate elevations in cytosolic free calcium concentration ([Ca{sup 2+}]{sub i}) via calcium influx through nAChR channels whereasmore » intracellular stores contribute to nAChR- and mAChR-mediated calcium fluxes in differentiated cells [Resende et al., Cell Calcium 43 (2008) 107-121]. In the present study, we have demonstrated that nicotine provoked inhibition of proliferation in embryonic cells as determined by BrdU labeling. However, in neural progenitor cells nicotine stimulated proliferation which was reversed in the presence of inhibitors of calcium mobilization from intracellular stores, indicating that liberation of intracellular calcium contributed to this proliferation induction. Muscarine induced proliferation stimulation in progenitor cells by activation of G{alpha}{sub q/11}-coupled M{sub 1}, M{sub 3} and M{sub 5} receptors and intracellular calcium stores, whereas G{alpha}{sub i/o}-protein coupled M{sub 2} receptor activity mediated neuronal differentiation.« less

HPV16 E6 Promotes Breast Cancer Proliferation via Upregulation of COX-2 Expression

PubMed Central

Li, Y. Z.; Zhang, Z. Y.; Wang, J. Q.

2017-01-01

Background. Breast cancer remains the leading cause of cancer-related mortality worldwide. It has been indicated that human papillomaviruses 16 (HPV16) might participate in the pathogenesis and development of breast cancer. However, the detected rate of HPV16 varies with region. We will investigate HPV16 E6 expression in North China and explore the effects and mechanism of HPV16 E6 on breast cancer proliferation in this study. Methods. The expressions of HPV16 E6 and COX-2 in paraffin-embedded tissues of the invasive ductal breast cancer were detected by qPCR and IHC. The effects of HPV16 E6 on breast cancer proliferation were determined by function studies. The mechanism of HPV16 E6 in promoting breast cancer proliferation was explored by Western blot and Dual-Luciferase Reporter Assay. Results. HPV16 E6 was positive in 28% invasive ductal breast carcinoma in North China; HPV16 E6 promoted breast cancer proliferation. Inhibition of COX-2 by siCOX-2 or Celecoxib attenuated the proliferation of breast cancer cells with HPV16 E6 expression; and the upregulation of COX-2 could be suppressed by the inhibition of NF-κB activity. Conclusion. HPV16 E6 promotes breast cancer proliferation by activation of NF-κB signaling pathway and increase of COX-2 expression. COX-2 will be a potential target for HPV16 E6-associated breast cancer. PMID:29250535

Involvement of cell proliferation in the process of follicular atresia in the guinea pig.

PubMed

Wang, Wei; Liu, Honglin; Ding, Wei; Gong, Yan; Chen, Jingwei; Hutz, Reinhold J; Mao, Dagan; Shi, Fangxiong

2010-08-01

Cell morphology and proliferation was investigated in the atretic follicles during estrous cycles in the guinea pig. Ovarian samples on days 1, 4, 8, 12 and 16 of the estrous cycle in the guinea pig were taken in the morning for histologic staining with hematoxylin and eosin (HE), and immunohistochemical staining of the protein proliferating cell nuclear antigen (PCNA). The results indicated that the granulosa cells degenerated and eliminated first in atretic follicles, while the fibroblast-like cells appeared in the innermost layer of theca interna cells. When the fibroblast-like cells migrated to the antrum, they proliferated and formed a new tissue in peripheral to the zona pellucida of the oocyte. Our results also revealed that the orientation of the theca interna cell arrangement changed twice during the process of atresia, and the loose connective tissue in the antrum was critical for follicular atresia. Therefore, follicular atresia was not a simple process of cell death and elimination, but coexisted with cell proliferation. To our knowledge, we have for the first time confirmed cell proliferation and the presence of new tissue in atretic follicles in guinea pigs. Copyright 2010 Elsevier Ltd. All rights reserved.

Peroxisome Proliferator-Activated Receptor Ligands and Their Role in Chronic Myeloid Leukemia: Therapeutic Strategies.

PubMed

Yousefi, Bahman; Samadi, Nasser; Baradaran, Behzad; Shafiei-Irannejad, Vahid; Zarghami, Nosratollah

2016-07-01

Imatinib therapy remains the gold standard for treatment of chronic myeloid leukemia; however, the acquired resistance to this therapeutic agent in patients has urged the scientists to devise modalities for overcoming this chemoresistance. For this purpose, initially therapeutic agents with higher tyrosine kinase activity were introduced, which had the potential for inhibiting even mutant forms of Bcr-Abl. Furthermore, coupling imatinib with peroxisome proliferator-activated receptor ligands also showed beneficial effects in chronic myeloid leukemia cell proliferation. These combination protocols inhibited cell growth and induced apoptosis as well as differentiation in chronic myeloid leukemia cell lines. In addition, peroxisome proliferator-activated receptors ligands increased imatinib uptake by upregulating the expression of human organic cation transporter 1. Taken together, peroxisome proliferator-activated receptors ligands are currently being considered as novel promising therapeutic candidates for chronic myeloid leukemia treatment, because they can synergistically enhance the efficacy of imatinib. In this article, we reviewed the potential of peroxisome proliferator-activated receptors ligands for use in chronic myeloid leukemia treatment. The mechanism of action of these therapeutics modalities are also presented in detail. © 2016 John Wiley & Sons A/S.

Paracrine influence of human perivascular cells on the proliferation of adenocarcinoma alveolar epithelial cells.

PubMed

Kim, Eunbi; Na, Sunghun; An, Borim; Yang, Se-Ran; Kim, Woo Jin; Ha, Kwon-Soo; Han, Eun-Taek; Park, Won Sun; Lee, Chang-Min; Lee, Ji Yoon; Lee, Seung-Joon; Hong, Seok-Ho

2017-03-01

Understanding the crosstalk mechanisms between perivascular cells (PVCs) and cancer cells might be beneficial in preventing cancer development and metastasis. In this study, we investigated the paracrine influence of PVCs derived from human umbilical cords on the proliferation of lung adenocarcinoma epithelial cells (A549) and erythroleukemia cells (TF-1α and K562) in vitro using Transwell® co-culture systems. PVCs promoted the proliferation of A549 cells without inducing morphological changes, but had no effect on the proliferation of TF-1α and K562 cells. To identify the factors secreted from PVCs, conditioned media harvested from PVC cultures were analyzed by antibody arrays. We identified a set of cytokines, including persephin (PSPN), a neurotrophic factor, and a key regulator of oral squamous cell carcinoma progression. Supplementation with PSPN significantly increased the proliferation of A549 cells. These results suggested that PVCs produced a differential effect on the proliferation of cancer cells in a cell-type dependent manner. Further, secretome analyses of PVCs and the elucidation of the molecular mechanisms could facilitate the discovery of therapeutic target(s) for lung cancer.

Carbachol induces TGF-alpha expression and colonic epithelial cell proliferation in sensory-desensitised rats.

PubMed

Bulut, Kerem; Felderbauer, Peter; Hoeck, Karoline; Schmidt, Wolfgang E; Hoffmann, Peter

2010-03-01

Signals for the expression of the peptide growth factors epidermal growth factor and transforming growth factor-alpha (TGFalpha) in the gastrointestinal mucosa are largely unknown. We have shown earlier that extrinsic afferents in the gastrointestinal tract induce TGFalpha expression in colonic mucosa via the deliberation of neurotransmitters substance P and calcitonin gene-related peptide. The aim of our present study was to determine the effects of carbachol on mucosal TGFalpha expression and epithelial cell proliferation in vivo. Rats were divided in three groups. Group 1 was treated with vehicle only, group 2 received one single subcutaneous injection of 250 microg/kg of carbachol and animals in group 3 were sensory-desensitised prior to the injection of 250 microg/kg carbachol. TGFalpha expression and epithelial cell proliferation was evaluated by polymerase chain reaction, Western blot analysis and bromodeoxyuridine staining. Carbachol induced a significant increase in mucosal epithelial cell proliferation and TGFalpha expression. Sensory desensitisation did neither abolish the increased TGFalpha expression nor the increase in epithelial cell proliferation. Parasympathetic pathways are involved in the control of TGFalpha expression in gastrointestinal mucosa as well as in epithelial cell proliferation.

Imbalance between proliferation and apoptosis-related impaired GPR30 expression is involved in preeclampsia.

PubMed

Li, Jianxin; Chen, Zhu; Zhou, Xiaobo; Shi, Shuming; Qi, Hongbo; Baker, Philip N; Zhang, Hua

2016-11-01

The proliferation and apoptosis of cells in the placenta play a critical role in preeclampsia (PE) in which estrogen has been implicated via estrogen receptors (ERs). A novel ER, G-protein-coupled receptor 30 (GPR30), has recently been shown to be involved in PE. We investigated the basic levels of proliferation and apoptosis in normal placentae and placentae with PE and compared GPR30 expression levels between the two groups. We demonstrated that low GPR30 expression levels, more apoptosis, and less proliferation were associated with PE. Moreover, our in vitro study showed that both the selective GPR30 agonist G1 and the general ER agonist 17-β-estradiol were able to protect the placenta from hypoxia-reoxygenation injuries, resulting in decreased apoptosis and increased proliferation. Furthermore, this protective effect was abolished by the addition of the selective GPR30 inhibitor G15. These results provide evidence that (1) GPR30 is involved in regulating cell proliferation and apoptosis; (2) pharmacologic upregulation of GPR30 is beneficial for PE management; (3) GPR30 may therefore be an interventional target for pregnancies complicated by PE.

Poisson-event-based analysis of cell proliferation.

PubMed

Summers, Huw D; Wills, John W; Brown, M Rowan; Rees, Paul

2015-05-01

A protocol for the assessment of cell proliferation dynamics is presented. This is based on the measurement of cell division events and their subsequent analysis using Poisson probability statistics. Detailed analysis of proliferation dynamics in heterogeneous populations requires single cell resolution within a time series analysis and so is technically demanding to implement. Here, we show that by focusing on the events during which cells undergo division rather than directly on the cells themselves a simplified image acquisition and analysis protocol can be followed, which maintains single cell resolution and reports on the key metrics of cell proliferation. The technique is demonstrated using a microscope with 1.3 μm spatial resolution to track mitotic events within A549 and BEAS-2B cell lines, over a period of up to 48 h. Automated image processing of the bright field images using standard algorithms within the ImageJ software toolkit yielded 87% accurate recording of the manually identified, temporal, and spatial positions of the mitotic event series. Analysis of the statistics of the interevent times (i.e., times between observed mitoses in a field of view) showed that cell division conformed to a nonhomogeneous Poisson process in which the rate of occurrence of mitotic events, λ exponentially increased over time and provided values of the mean inter mitotic time of 21.1 ± 1.2 hours for the A549 cells and 25.0 ± 1.1 h for the BEAS-2B cells. Comparison of the mitotic event series for the BEAS-2B cell line to that predicted by random Poisson statistics indicated that temporal synchronisation of the cell division process was occurring within 70% of the population and that this could be increased to 85% through serum starvation of the cell culture. © 2015 International Society for Advancement of Cytometry.

Improved fibronectin-immobilized fibrinogen microthreads for the attachment and proliferation of fibroblasts

PubMed Central

Rajangam, Thanavel; An, Seong Soo A

2013-01-01

The aim of this study was to fabricate fibrinogen (Fbg) microfibers with different structural characteristics for the development of 3-D tissue-engineering scaffolds. Fabricated Fbg microfibers were investigated for their biomolecule encapsulation, cell adhesion, and proliferations. Microfibers with three different concentrations of Fbg (5, 10, and 15 wt%) were prepared by a gel solvent-extraction method using a silicone rubber tube. Fbg microfibers were covalently modified with fibronectin (FN) by using water-soluble 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide as the cross-linking agent. Fbg microfibers were characterized by their FN cross-linking properties, structural morphology, and in vitro degradation. Furthermore, FN/Fbg microfibers were evaluated for cell attachment and proliferation. The bio-compatibility and cell proliferation of the microfibers were assessed by measuring adenosine triphosphate activity in C2C12 fibroblast cells. Cell attachment and proliferation on microfibers were further examined using fluorescence and scanning electron microscopic images. FN loading on the microfibers was confirmed by fluorescence and infrared spectroscopy. Surface morphology was characterized by scanning electron microscopy, and showed highly aligned nanostructures for fibers made with 15 wt% Fbg, a more porous structure for fibers made with 10 wt% Fbg, and a less porous structure for those made with 5 wt% Fbg. Controlled biodegradation of the fiber was observed for 8 weeks by using an in vitro proteolytic degradation assay. Fbg microfibers with highly aligned nanostructures (15 wt%) showed enhanced biomolecule encapsulation, as well as higher cell adhesion and proliferation than another two types of FN/Fbg fibers (5 and 10 wt%) and unmodified Fbg fibers. The promising results obtained from the present study reveal that optimal structure of Fbg microfibers could be used as a potential substratum for growth factors or drug release, especially in wound healing and

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

Neuron-derived orphan receptor 1 promoted human pulmonary artery smooth muscle cells proliferation.

PubMed

Wang, Chang-Guo; Lei, Wei; Li, Chang; Zeng, Da-Xiong; Huang, Jian-An

2015-05-01

As a transcription factor of the nuclear receptor superfamily, neuron-derived orphan receptor 1 (NOR1) is induced rapidly in response to various extracellular stimuli. But, it is still unclear its role in pulmonary artery smooth muscle cells proliferation. Human PASMCs were cultured in vitro and stimulated by serum. The special antisense oligodeoxynucleotides (AS-ODNs) were used to knockdown human NOR1 gene expression. Real-time PCR and Western-blot were used to evaluate the gene expression and protein levels. Fetal bovine serum (FBS) induced human PASMCs proliferation in a dose dependent manner. Furthermore, FBS promoted NOR1 gene expression in a dose dependent manner and a time dependent manner. 10% FBS induced a maximal NOR1 mRNA levels at 2 h. FBS also induced a significant higher NOR1 protein levels as compared with control. The NOR1 over-expressed plasmid significantly promoted DNA synthesis and cells proliferation. Moreover, the special AS-ODNs against human NOR1 not only prevented NOR1 expression but also inhibited DNA synthesis and cells proliferation significantly. The NOR1 over-expression plasmid could up-regulate cyclin D1 expression markedly, but the AS-ODNs inhibited cyclin D1 expression significantly. So, we concluded that NOR1 could promote human PASMCs proliferation. Cyclin D1 might be involved in this process.

Repression of myoblast proliferation and fibroblast growth factor receptor 1 promoter activity by KLF10 protein.

PubMed

Parakati, Rajini; DiMario, Joseph X

2013-05-10

FGFR1 gene expression regulates myoblast proliferation and differentiation, and its expression is controlled by Krüppel-like transcription factors. KLF10 interacts with the FGFR1 promoter, repressing its activity and cell proliferation. KLF10 represses FGFR1 promoter activity and thereby myoblast proliferation. A model of transcriptional control of chicken FGFR1 gene regulation during myogenesis is presented. Skeletal muscle development is controlled by regulation of myoblast proliferation and differentiation into muscle fibers. Growth factors such as fibroblast growth factors (FGFs) and their receptors (FGFRs) regulate cell proliferation and differentiation in numerous tissues, including skeletal muscle. Transcriptional regulation of FGFR1 gene expression is developmentally regulated by the Sp1 transcription factor, a member of the Krüppel-like factor (KLF) family of transcriptional regulators. Here, we show that another KLF transcription factor, KLF10, also regulates myoblast proliferation and FGFR1 promoter activity. Expression of KLF10 reduced myoblast proliferation by 86%. KLF10 expression also significantly reduced FGFR1 promoter activity in myoblasts and Sp1-mediated FGFR1 promoter activity in Drosophila SL2 cells. Southwestern blot, electromobility shift, and chromatin immunoprecipitation assays demonstrated that KLF10 bound to the proximal Sp factor binding site of the FGFR1 promoter and reduced Sp1 complex formation with the FGFR1 promoter at that site. These results indicate that KLF10 is an effective repressor of myoblast proliferation and represses FGFR1 promoter activity in these cells via an Sp1 binding site.

Mechanical unloading reduces microtubule actin crosslinking factor 1 expression to inhibit β-catenin signaling and osteoblast proliferation.

PubMed

Yin, Chong; Zhang, Yan; Hu, Lifang; Tian, Ye; Chen, Zhihao; Li, Dijie; Zhao, Fan; Su, Peihong; Ma, Xiaoli; Zhang, Ge; Miao, Zhiping; Wang, Liping; Qian, Airong; Xian, Cory J

2018-07-01

Mechanical unloading was considered a major threat to bone homeostasis, and has been shown to decrease osteoblast proliferation although the underlying mechanism is unclear. Microtubule actin crosslinking factor 1 (MACF1) is a cytoskeletal protein that regulates cellular processes and Wnt/β-catenin pathway, an essential signaling pathway for osteoblasts. However, the relationship between MACF1 expression and mechanical unloading, and the function and the associated mechanisms of MACF1 in regulating osteoblast proliferation are unclear. This study investigated effects of mechanical unloading on MACF1 expression levels in cultured MC3T3-E1 osteoblastic cells and in femurs of mice with hind limb unloading; and it also examined the role and potential action mechanisms of MACF1 in osteoblast proliferation in MACF1-knockdown, overexpressed or control MC3T3-E1 cells treated with or without the mechanical unloading condition. Results showed that the mechanical unloading condition inhibited osteoblast proliferation and MACF1 expression in MC3T3-E1 osteoblastic cells and mouse femurs. MACF1 knockdown decreased osteoblast proliferation, while MACF1 overexpression increased it. The inhibitory effect of mechanical unloading on osteoblast proliferation also changed with MACF1 expression levels. Furthermore, MACF1 was found to enhance β-catenin expression and activity, and mechanical unloading decreased β-catenin expression through MACF1. Moreover, β-catenin was found an important regulator of osteoblast proliferation, as its preservation by treatment with its agonist lithium attenuated the inhibitory effects of MACF1-knockdown or mechanical unloading on osteoblast proliferation. Taken together, mechanical unloading decreases MACF1 expression, and MACF1 up-regulates osteoblast proliferation through enhancing β-catenin signaling. This study has thus provided a mechanism for mechanical unloading-induced inhibited osteoblast proliferation. © 2017 Wiley Periodicals, Inc.

Biofilms’ Role in Planktonic Cell Proliferation

PubMed Central

Bester, Elanna; Wolfaardt, Gideon M.; Aznaveh, Nahid B.; Greener, Jesse

2013-01-01

The detachment of single cells from biofilms is an intrinsic part of this surface-associated mode of bacterial existence. Pseudomonas sp. strain CT07gfp biofilms, cultivated in microfluidic channels under continuous flow conditions, were subjected to a range of liquid shear stresses (9.42 mPa to 320 mPa). The number of detached planktonic cells was quantified from the effluent at 24-h intervals, while average biofilm thickness and biofilm surface area were determined by confocal laser scanning microscopy and image analysis. Biofilm accumulation proceeded at the highest applied shear stress, while similar rates of planktonic cell detachment was maintained for biofilms of the same age subjected to the range of average shear rates. The conventional view of liquid-mediated shear leading to the passive erosion of single cells from the biofilm surface, disregards the active contribution of attached cell metabolism and growth to the observed detachment rates. As a complement to the conventional conceptual biofilm models, the existence of a biofilm surface-associated zone of planktonic cell proliferation is proposed to highlight the need to expand the traditional perception of biofilms as promoting microbial survival, to include the potential of biofilms to contribute to microbial proliferation. PMID:24201127

Homeostatic action of adenosine A3 and A1 receptor agonists on proliferation of hematopoietic precursor cells.

PubMed

Hofer, Michal; Pospísil, Milan; Znojil, Vladimír; Holá, Jirina; Streitová, Denisa; Vacek, Antonín

2008-07-01

Two adenosine receptor agonists, N6-(3-iodobenzyl)adenosine-5'-N-methyluronamide (IB-MECA) and N6-cyclopentyladenosine (CPA), which selectively activate adenosine A3 and A1 receptors, respectively, were tested for their ability to influence proliferation of granulocytic and erythroid cells in femoral bone marrow of mice using morphological criteria. Agonists were given intraperitoneally to mice in repeated isomolar doses of 200 nmol/kg. Three variants of experiments were performed to investigate the action of the agonists under normal resting state of mice and in phases of cell depletion and subsequent regeneration after treatment with the cytotoxic drug 5-fluorouracil. In the case of granulopoiesis, IB-MECA 1) increased by a moderate but significant level proliferation of cells under normal resting state; 2) strongly increased proliferation of cells in the cell depletion phase; but 3) did not influence cell proliferation in the regeneration phase. CPA did not influence cell proliferation under normal resting state and in the cell depletion phase, but strongly suppressed the overshooting cell proliferation in the regeneration phase. The stimulatory effect of IB-MECA on cell proliferation of erythroid cells was observed only when this agonist was administered during the cell depletion phase. CPA did not modulate erythroid proliferation in any of the functional states investigated, probably due to the lower demand for cell production as compared with granulopoiesis. The results indicate opposite effects of the two adenosine receptor agonists on proliferation of hematopoietic cells and suggest the plasticity and homeostatic role of the adenosine receptor expression.

Approach to proliferation risk assessment based on multiple objective analysis framework

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

Andrianov, A.; Kuptsov, I.; Studgorodok 1, Obninsk, Kaluga region, 249030

2013-07-01

The approach to the assessment of proliferation risk using the methods of multi-criteria decision making and multi-objective optimization is presented. The approach allows the taking into account of the specifics features of the national nuclear infrastructure, and possible proliferation strategies (motivations, intentions, and capabilities). 3 examples of applying the approach are shown. First, the approach has been used to evaluate the attractiveness of HEU (high enriched uranium)production scenarios at a clandestine enrichment facility using centrifuge enrichment technology. Secondly, the approach has been applied to assess the attractiveness of scenarios for undeclared production of plutonium or HEU by theft of materialsmore » circulating in nuclear fuel cycle facilities and thermal reactors. Thirdly, the approach has been used to perform a comparative analysis of the structures of developing nuclear power systems based on different types of nuclear fuel cycles, the analysis being based on indicators of proliferation risk.« less

p62 Regulates the Proliferation of Molecular Apocrine Breast Cancer Cells

PubMed Central

Nozaki, Fumi; Hirotani, Yukari; Nakanishi, Yoko; Yamaguchi, Hiromi; Nishimaki, Haruna; Noda, Hiroko; Tang, Xiaoyan; Yamamoto, Hisae; Suzuki, Atsuko; Seki, Toshimi; Masuda, Shinobu

2016-01-01

p62, also called sequestosome 1 (SQSTM1), is a multifunctional signaling molecule that affects cell proliferation. Recently, we found accumulation of p62 in apocrine carcinoma of the breast, however, the biological role of p62 expression in apocrine carcinoma still remains unclear. To investigate whether p62 might contribute to tumor cell proliferation in apocrine carcinomas, we used the MDA-MB-453 (androgen receptor-positive, HER2-type) and MFM223 (androgen receptor-positive, triple-negative type) breast cancer cell lines as models of molecular apocrine carcinoma. Both MDA-MB-453 and MFM223 showed strong and d high p62 protein expression than MCF7 cells (androgen receptor-negative, luminal A type). Knockdown of p62 resulted in significant reduction of the cell proliferative activity in both MDA-MB-453 (P<0.01) and MFM223 (P<0.05). In conclusion, p62 could contribute to cell proliferation and represent a therapeutic target in apocrine carcinoma. PMID:27682016

p62 Regulates the Proliferation of Molecular Apocrine Breast Cancer Cells.

PubMed

Nozaki, Fumi; Hirotani, Yukari; Nakanishi, Yoko; Yamaguchi, Hiromi; Nishimaki, Haruna; Noda, Hiroko; Tang, Xiaoyan; Yamamoto, Hisae; Suzuki, Atsuko; Seki, Toshimi; Masuda, Shinobu

2016-08-30

p62, also called sequestosome 1 (SQSTM1), is a multifunctional signaling molecule that affects cell proliferation. Recently, we found accumulation of p62 in apocrine carcinoma of the breast, however, the biological role of p62 expression in apocrine carcinoma still remains unclear. To investigate whether p62 might contribute to tumor cell proliferation in apocrine carcinomas, we used the MDA-MB-453 (androgen receptor-positive, HER2-type) and MFM223 (androgen receptor-positive, triple-negative type) breast cancer cell lines as models of molecular apocrine carcinoma. Both MDA-MB-453 and MFM223 showed strong and d high p62 protein expression than MCF7 cells (androgen receptor-negative, luminal A type). Knockdown of p62 resulted in significant reduction of the cell proliferative activity in both MDA-MB-453 (P<0.01) and MFM223 (P<0.05). In conclusion, p62 could contribute to cell proliferation and represent a therapeutic target in apocrine carcinoma.

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

Hippo/Yap signaling controls epithelial progenitor cell proliferation and differentiation in the embryonic and adult lung

PubMed Central

Lange, Alexander W.; Sridharan, Anusha; Xu, Yan; Stripp, Barry R.; Perl, Anne-Karina; Whitsett, Jeffrey A.

2015-01-01

The Hippo/Yap pathway is a well-conserved signaling cascade that regulates cell proliferation and differentiation to control organ size and stem/progenitor cell behavior. Following airway injury, Yap was dynamically regulated in regenerating airway epithelial cells. To determine the role of Hippo signaling in the lung, the mammalian Hippo kinases, Mst1 and Mst2, were deleted in epithelial cells of the embryonic and mature mouse lung. Mst1/2 deletion in the fetal lung enhanced proliferation and inhibited sacculation and epithelial cell differentiation. The transcriptional inhibition of cell proliferation and activation of differentiation during normal perinatal lung maturation were inversely regulated following embryonic Mst1/2 deletion. Ablation of Mst1/2 from bronchiolar epithelial cells in the adult lung caused airway hyperplasia and altered differentiation. Inhibitory Yap phosphorylation was decreased and Yap nuclear localization and transcriptional targets were increased after Mst1/2 deletion, consistent with canonical Hippo/Yap signaling. YAP potentiated cell proliferation and inhibited differentiation of human bronchial epithelial cells in vitro. Loss of Mst1/2 and expression of YAP regulated transcriptional targets controlling cell proliferation and differentiation, including Ajuba LIM protein. Ajuba was required for the effects of YAP on cell proliferation in vitro. Hippo/Yap signaling regulates Ajuba and controls proliferation and differentiation of lung epithelial progenitor cells. PMID:25480985

Bone marrow–based homeostatic proliferation of mature T cells in nonhuman primates: implications for AIDS pathogenesis

PubMed Central

Paiardini, Mirko; Cervasi, Barbara; Engram, Jessica C.; Gordon, Shari N.; Klatt, Nichole R.; Muthukumar, Alagarraju; Else, James; Mittler, Robert S.; Staprans, Silvija I.; Sodora, Donald L.

2009-01-01

Bone marrow (BM) is the key hematopoietic organ in mammals and is involved in the homeostatic proliferation of memory CD8+ T cells. Here we expanded on our previous observation that BM is a preferential site for T-cell proliferation in simian immunodeficiency virus (SIV)–infected sooty mangabeys (SMs) that do not progress to AIDS despite high viremia. We found high levels of mature T-cell proliferation, involving both naive and memory cells, in healthy SMs and rhesus macaques (RMs). In addition, we observed in both species that lineage-specific, BM-based T-cell proliferation follows antibody-mediated in vivo CD4+ or CD8+ T-cell depletion, thus indicating a role for the BM in maintaining T-cell homeostasis under depleting circumstances. We also observed that, in SIV-infected SMs, but not RMs, the level of proliferation of BM-based CD4+ T cells is higher than that of circulating CD4+ T cells. Interestingly, limited BM-based CD4+ T-cell proliferation was found in SIV-infected SMs with low CD4+ T-cell counts, suggesting a regenerative failure in these animals. Collectively, these results indicate that BM is involved in maintaining T-cell homeostasis in primates and suggest a role for BM-based CD4+ T-cell proliferation in determining the benign nature of natural SIV infection of SMs. PMID:18832134

Bone marrow-based homeostatic proliferation of mature T cells in nonhuman primates: implications for AIDS pathogenesis.

PubMed

Paiardini, Mirko; Cervasi, Barbara; Engram, Jessica C; Gordon, Shari N; Klatt, Nichole R; Muthukumar, Alagarraju; Else, James; Mittler, Robert S; Staprans, Silvija I; Sodora, Donald L; Silvestri, Guido

2009-01-15

Bone marrow (BM) is the key hematopoietic organ in mammals and is involved in the homeostatic proliferation of memory CD8(+) T cells. Here we expanded on our previous observation that BM is a preferential site for T-cell proliferation in simian immunodeficiency virus (SIV)-infected sooty mangabeys (SMs) that do not progress to AIDS despite high viremia. We found high levels of mature T-cell proliferation, involving both naive and memory cells, in healthy SMs and rhesus macaques (RMs). In addition, we observed in both species that lineage-specific, BM-based T-cell proliferation follows antibody-mediated in vivo CD4(+) or CD8(+) T-cell depletion, thus indicating a role for the BM in maintaining T-cell homeostasis under depleting circumstances. We also observed that, in SIV-infected SMs, but not RMs, the level of proliferation of BM-based CD4(+) T cells is higher than that of circulating CD4(+) T cells. Interestingly, limited BM-based CD4(+) T-cell proliferation was found in SIV-infected SMs with low CD4(+) T-cell counts, suggesting a regenerative failure in these animals. Collectively, these results indicate that BM is involved in maintaining T-cell homeostasis in primates and suggest a role for BM-based CD4(+) T-cell proliferation in determining the benign nature of natural SIV infection of SMs.

Reciprocal actions of microRNA-9 and TLX in the proliferation and differentiation of retinal progenitor cells.

PubMed

Hu, Yamin; Luo, Min; Ni, Ni; Den, Yuan; Xia, Jing; Chen, Junzhao; Ji, Jing; Zhou, Xiaojian; Fan, Xianqun; Gu, Ping

2014-11-15

Recent research has demonstrated critical roles of a number of microRNAs (miRNAs) in stem cell proliferation and differentiation. miRNA-9 (miR-9) is a brain-enriched miRNA. Whether miR-9 has a role in retinal progenitor cell (RPC) proliferation and differentiation remains unknown. In this study, we show that miR-9 plays an important role in RPC fate determination. The expression of miR-9 was inversely correlated with that of the nuclear receptor TLX, which is an essential regulator of neural stem cell self-renewal. Overexpression of miR-9 downregulated the TLX levels in RPCs, leading to reduced RPC proliferation and increased neuronal and glial differentiation, and the effect of miR-9 overexpression on RPC proliferation and differentiation was inhibited by the TLX overexpression; knockdown of miR-9 resulted in increased TLX expression as well as enhanced proliferation of RPCs. Furthermore, inhibition of endogenous TLX by small interfering RNA suppressed RPC proliferation and promoted RPCs to differentiate into retinal neuronal and glial cells. These results suggest that miR-9 and TLX form a feedback regulatory loop to coordinate the proliferation and differentiation of retinal progenitors.

Sirtuin 1 Mediates the Actions of Peroxisome Proliferator-Activated Receptor δ on the Oxidized Low-Density Lipoprotein-Triggered Migration and Proliferation of Vascular Smooth Muscle Cells.

PubMed

Hwang, Jung Seok; Ham, Sun Ah; Yoo, Taesik; Lee, Won Jin; Paek, Kyung Shin; Lee, Chi-Ho; Seo, Han Geuk

2016-11-01

Peroxisome proliferator-activated receptor δ (PPARδ) has been implicated in vascular pathophysiology. However, its functions in atherogenic changes of the vascular wall have not been fully elucidated. PPARδ activated by GW501516 (2-[2-methyl-4-[[4-methyl-2-[4-(trifluoromethyl)phenyl]-1,3-thiazol-5-yl]methylsulfanyl]phenoxy]acetic acid) significantly inhibited the migration and proliferation of vascular smooth muscle cells (VSMCs) triggered by oxidized low-density lipoprotein (oxLDL). These GW501516-mediated effects were significantly reversed by PPARδ-targeting small-interfering RNA (siRNA), indicating that PPARδ is involved in the action of GW501516. The antiproliferative effect of GW501516 was directly linked to cell cycle arrest at the G 0 /G 1 to S phase transition, which was followed by the down-regulation of cyclin-dependent kinase 4 along with increased levels of p21 and p53. In VSMCs treated with GW501516, the expression of sirtuin 1 (SIRT1) mRNA and protein was time-dependently increased. This GW501516-mediated up-regulation of SIRT1 expression was also demonstrated even in the presence of oxLDL. In addition, GW501516-dependent inhibition of oxLDL-triggered migration and proliferation of VSMCs was almost completely abolished in the presence of SIRT1-targeting siRNA. These effects of GW501516 on oxLDL-triggered phenotypic changes of VSMCs were also demonstrated via activation or inhibition of SIRT1 activity by resveratrol or sirtinol, respectively. Finally, gain or loss of SIRT1 function imitated the action of PPARδ on oxLDL-triggered migration and proliferation of VSMCs. Taken together, these observations indicate that PPARδ-dependent up-regulation of SIRT1 contributes to the antiatherogenic activities of PPARδ by suppressing the migration and proliferation of VSMCs linked to vascular diseases such as restenosis and atherosclerosis. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

DNA methyltransferase mediates dose-dependent stimulation of neural stem cell proliferation by folate.

PubMed

Li, Wen; Yu, Min; Luo, Suhui; Liu, Huan; Gao, Yuxia; Wilson, John X; Huang, Guowei

2013-07-01

The proliferative response of neural stem cells (NSCs) to folate may play a critical role in the development, function and repair of the central nervous system. It is important to determine the dose-dependent effects of folate in NSC cultures that are potential sources of transplantable cells for therapies for neurodegenerative diseases. To determine the optimal concentration and mechanism of action of folate for stimulation of NSC proliferation in vitro, NSCs were exposed to folic acid or 5-methyltetrahydrofolate (5-MTHF) (0-200 μmol/L) for 24, 48 or 72 h. Immunocytochemistry and methyl thiazolyl tetrazolium assay showed that the optimal concentration of folic acid for NSC proliferation was 20-40 μmol/L. Stimulation of NSC proliferation by folic acid was associated with DNA methyltransferase (DNMT) activation and was attenuated by the DNMT inhibitor zebularine, which implies that folate dose-dependently stimulates NSC proliferation through a DNMT-dependent mechanism. Based on these new findings and previously published evidence, we have identified a mechanism by which folate stimulates NSC growth. Copyright © 2013 Elsevier Inc. All rights reserved.

MYB36 regulates the transition from proliferation to differentiation in the Arabidopsis root

PubMed Central

Liberman, Louisa M.; Sparks, Erin E.; Moreno-Risueno, Miguel A.; Petricka, Jalean J.; Benfey, Philip N.

2015-01-01

Stem cells are defined by their ability to self-renew and produce daughter cells that proliferate and mature. These maturing cells transition from a proliferative state to a terminal state through the process of differentiation. In the Arabidopsis thaliana root the transcription factors SCARECROW and SHORTROOT regulate specification of the bipotent stem cell that gives rise to cortical and endodermal progenitors. Subsequent progenitor proliferation and differentiation generate mature endodermis, marked by the Casparian strip, a cell-wall modification that prevents ion diffusion into and out of the vasculature. We identified a transcription factor, MYB DOMAIN PROTEIN 36 (MYB36), that regulates the transition from proliferation to differentiation in the endodermis. We show that SCARECROW directly activates MYB36 expression, and that MYB36 likely acts in a feed-forward loop to regulate essential Casparian strip formation genes. We show that myb36 mutants have delayed and defective barrier formation as well as extra divisions in the meristem. Our results demonstrate that MYB36 is a critical positive regulator of differentiation and negative regulator of cell proliferation. PMID:26371322

Continuous Time Random Walk and Migration-Proliferation Dichotomy of Brain Cancer

NASA Astrophysics Data System (ADS)

Iomin, A.

A theory of fractional kinetics of glial cancer cells is presented. A role of the migration-proliferation dichotomy in the fractional cancer cell dynamics in the outer-invasive zone is discussed and explained in the framework of a continuous time random walk. The main suggested model is based on a construction of a 3D comb model, where the migration-proliferation dichotomy becomes naturally apparent and the outer-invasive zone of glioma cancer is considered as a fractal composite with a fractal dimension Dfr < 3.

Daucosterol promotes the proliferation of neural stem cells.

PubMed

Jiang, Li-hua; Yang, Nian-yun; Yuan, Xiao-lin; Zou, Yi-jie; Zhao, Feng-ming; Chen, Jian-ping; Wang, Ming-yan; Lu, Da-xiang

2014-03-01

Neural stem cells (NSCs) are self-regenerating cells, but their regenerative capacity is limited. The present study was conducted to investigate the effect of daucosterol (a sterolin) on the promotion of NSC proliferation and determine the corresponding molecular mechanism. Results of cell counting kit-8 (CCK-8) assay showed that daucosterol significantly increased the quantity of viable cells and the effectiveness of daucosterol was similar to that of basic fibroblast growth factor (bFGF) and epidermal growth factor (EGF). Flow cytometry detection of CFSE-labeled (CFSE, carboxyfluorescein diacetate succinimidyl ester) NSCs showed that Div Index (or the average number of cell divisions) and % Divided (or the percentage of cells that divided at least once) of the cells were increased, indicating that daucosterol increased the percentage of NSCs re-entering the cell cycle. mRNA microarray analysis showed that 333 genes that are mostly involved in the mitotic cell cycle were up-regulated. By contrast, 627 genes that are mostly involved in differentiation were down-regulated. In particular, insulin-like growth factor I (IGF1) was considered as an important regulatory gene that functionally promoted NSC proliferation, and the increased expression of IGF1 protein was validated by ELISA. In addition, the phosphorylation of AKT was increased, indicating that the proliferation-enhancing activity of daucosterol may be involved in IGF1-AKT pathway. Our study provided information about daucosterol as an efficient and inexpensive growth factor alternative that could be used in clinical medicine and research applications. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Neural and oligodendrocyte progenitor cells: transferrin effects on cell proliferation