Open chromatin encoded in DNA sequence is the signature of ‘master’ replication origins in human cells

PubMed Central

Audit, Benjamin; Zaghloul, Lamia; Vaillant, Cédric; Chevereau, Guillaume; d'Aubenton-Carafa, Yves; Thermes, Claude; Arneodo, Alain

2009-01-01

For years, progress in elucidating the mechanisms underlying replication initiation and its coupling to transcriptional activities and to local chromatin structure has been hampered by the small number (approximately 30) of well-established origins in the human genome and more generally in mammalian genomes. Recent in silico studies of compositional strand asymmetries revealed a high level of organization of human genes around 1000 putative replication origins. Here, by comparing with recently experimentally identified replication origins, we provide further support that these putative origins are active in vivo. We show that regions ∼300-kb wide surrounding most of these putative replication origins that replicate early in the S phase are hypersensitive to DNase I cleavage, hypomethylated and present a significant enrichment in genomic energy barriers that impair nucleosome formation (nucleosome-free regions). This suggests that these putative replication origins are specified by an open chromatin structure favored by the DNA sequence. We discuss how this distinctive attribute makes these origins, further qualified as ‘master’ replication origins, priviledged loci for future research to decipher the human spatio-temporal replication program. Finally, we argue that these ‘master’ origins are likely to play a key role in genome dynamics during evolution and in pathological situations. PMID:19671527

Discovery of Azurin-Like Anticancer Bacteriocins from Human Gut Microbiome through Homology Modeling and Molecular Docking against the Tumor Suppressor p53.

PubMed

Nguyen, Chuong; Nguyen, Van Duy

2016-01-01

Azurin from Pseudomonas aeruginosa is known anticancer bacteriocin, which can specifically penetrate human cancer cells and induce apoptosis. We hypothesized that pathogenic and commensal bacteria with long term residence in human body can produce azurin-like bacteriocins as a weapon against the invasion of cancers. In our previous work, putative bacteriocins have been screened from complete genomes of 66 dominant bacteria species in human gut microbiota and subsequently characterized by subjecting them as functional annotation algorithms with azurin as control. We have qualitatively predicted 14 putative bacteriocins that possessed functional properties very similar to those of azurin. In this work, we perform a number of quantitative and structure-based analyses including hydrophobic percentage calculation, structural modeling, and molecular docking study of bacteriocins of interest against protein p53, a cancer target. Finally, we have identified 8 putative bacteriocins that bind p53 in a same manner as p28-azurin and azurin, in which 3 peptides (p1seq16, p2seq20, and p3seq24) shared with our previous study and 5 novel ones (p1seq09, p2seq05, p2seq08, p3seq02, and p3seq17) discovered in the first time. These bacteriocins are suggested for further in vitro tests in different neoplastic line cells.

Discovery of Azurin-Like Anticancer Bacteriocins from Human Gut Microbiome through Homology Modeling and Molecular Docking against the Tumor Suppressor p53

PubMed Central

Nguyen, Chuong; Nguyen, Van Duy

2016-01-01

Azurin from Pseudomonas aeruginosa is known anticancer bacteriocin, which can specifically penetrate human cancer cells and induce apoptosis. We hypothesized that pathogenic and commensal bacteria with long term residence in human body can produce azurin-like bacteriocins as a weapon against the invasion of cancers. In our previous work, putative bacteriocins have been screened from complete genomes of 66 dominant bacteria species in human gut microbiota and subsequently characterized by subjecting them as functional annotation algorithms with azurin as control. We have qualitatively predicted 14 putative bacteriocins that possessed functional properties very similar to those of azurin. In this work, we perform a number of quantitative and structure-based analyses including hydrophobic percentage calculation, structural modeling, and molecular docking study of bacteriocins of interest against protein p53, a cancer target. Finally, we have identified 8 putative bacteriocins that bind p53 in a same manner as p28-azurin and azurin, in which 3 peptides (p1seq16, p2seq20, and p3seq24) shared with our previous study and 5 novel ones (p1seq09, p2seq05, p2seq08, p3seq02, and p3seq17) discovered in the first time. These bacteriocins are suggested for further in vitro tests in different neoplastic line cells. PMID:27239476

Stimulation of plasmin activity in cultured human fibroblast cells by Porphyromonas endodontalis.

PubMed

Oikawa, T; Ogura, N; Akiba, M; Abiko, Y; Takiguchi, H; Izumi, H

1993-09-01

1. Plasmin activity in the conditioned medium of Gin-1 cells, a human gingival fibroblast cell line, was stimulated by Porphyromonas endodontalis, a putative pathogen of oral submucous abscesses, in a time- and dose-dependent manner. 2. P. endodontalis stimulated the activity of plasminogen activator in both the conditioned medium and the cell lysate. The plasminogen activator in Gin-1 cells was approx. 50 kDa by zymography. 3. The conditioned medium of Gin-1 cells exposed to P. endodontalis stimulated the conversion of human serum prekallikrein to kallikrein. 4. These results suggested that P. endodontalis stimulates the plasminogen activator-plasmin system in Gin-1 cells, and that activated plasmin plays a role in the progress of periodontal tissue inflammation.

Identification of putative Z-ring-associated proteins, involved in cell division in human pathogenic bacteria Helicobacter pylori.

PubMed

Kamran, Mohammad; Sinha, Swati; Dubey, Priyanka; Lynn, Andrew M; Dhar, Suman K

2016-07-01

Cell division in bacteria is initiated by FtsZ, which forms a Z ring at the middle of the cell, between the nucleoids. The Z ring is stabilized by Z ring-associated proteins (Zaps), which crosslink the FtsZ filaments and provide strength. The deletion of Zaps leads to the elongation phenotype with an abnormal Z ring. The components of cell division in Helicobacter pylori are similar to other gram negative bacteria except for the absence of few components including Zaps. Here, we used HHsearch to identify homologs of the missing cell division proteins and got potential hits for ZapA and ZapB, as well as for few other cell division proteins. We further validated the function of the putative ZapA homolog by genetic complementation, immuno-colocalization and biochemical analysis. © 2016 Federation of European Biochemical Societies.

Identification of Cytoplasmic Proteins Interacting with the Mammary Cell Transforming Domain of Ese-1

DTIC Science & Technology

2007-04-01

experiments using antibodies targeting epitope-tagged recombinant forms of these three putative SBCPs and recombinant and endogenous Ese- 1. These...The antagonistic regulation of human MUC4 and ErbB-2 genes by the Ets protein PEA3 in pancreatic cancer cells: implications for the proliferation

FOXM1 upregulation is an early event in human squamous cell carcinoma and it is enhanced by nicotine during malignant transformation.

PubMed

Gemenetzidis, Emilios; Bose, Amrita; Riaz, Adeel M; Chaplin, Tracy; Young, Bryan D; Ali, Muhammad; Sugden, David; Thurlow, Johanna K; Cheong, Sok-Ching; Teo, Soo-Hwang; Wan, Hong; Waseem, Ahmad; Parkinson, Eric K; Fortune, Farida; Teh, Muy-Teck

2009-01-01

Cancer associated with smoking and drinking remains a serious health problem worldwide. The survival of patients is very poor due to the lack of effective early biomarkers. FOXM1 overexpression is linked to the majority of human cancers but its mechanism remains unclear in head and neck squamous cell carcinoma (HNSCC). FOXM1 mRNA and protein expressions were investigated in four independent cohorts (total 75 patients) consisting of normal, premalignant and HNSCC tissues and cells using quantitative PCR (qPCR), expression microarray, immunohistochemistry and immunocytochemistry. Effect of putative oral carcinogens on FOXM1 transcriptional activity was dose-dependently assayed and confirmed using a FOXM1-specific luciferase reporter system, qPCR, immunoblotting and short-hairpin RNA interference. Genome-wide single nucleotide polymorphism (SNP) array was used to 'trace' the genomic instability signature pattern in 8 clonal lines of FOXM1-induced malignant human oral keratinocytes. Furthermore, acute FOXM1 upregulation in primary oral keratinocytes directly induced genomic instability. We have shown for the first time that overexpression of FOXM1 precedes HNSCC malignancy. Screening putative carcinogens in human oral keratinocytes surprisingly showed that nicotine, which is not perceived to be a human carcinogen, directly induced FOXM1 mRNA, protein stabilisation and transcriptional activity at concentrations relevant to tobacco chewers. Importantly, nicotine also augmented FOXM1-induced transformation of human oral keratinocytes. A centrosomal protein CEP55 and a DNA helicase/putative stem cell marker HELLS, both located within a consensus loci (10q23), were found to be novel targets of FOXM1 and their expression correlated tightly with HNSCC progression. This study cautions the potential co-carcinogenic effect of nicotine in tobacco replacement therapies. We hypothesise that aberrant upregulation of FOXM1 may be inducing genomic instability through a program of malignant transformation involving the activation of CEP55 and HELLS which may facilitate aberrant mitosis and epigenetic modifications. Our finding that FOXM1 is upregulated early during oral cancer progression renders FOXM1 an attractive diagnostic biomarker for early cancer detection and its candidate mechanistic targets, CEP55 and HELLS, as indicators of malignant conversion and progression.

Target cell cyclophilins facilitate human papillomavirus type 16 infection.

PubMed

Bienkowska-Haba, Malgorzata; Patel, Hetalkumar D; Sapp, Martin

2009-07-01

Following attachment to primary receptor heparan sulfate proteoglycans (HSPG), human papillomavirus type 16 (HPV16) particles undergo conformational changes affecting the major and minor capsid proteins, L1 and L2, respectively. This results in exposure of the L2 N-terminus, transfer to uptake receptors, and infectious internalization. Here, we report that target cell cyclophilins, peptidyl-prolyl cis/trans isomerases, are required for efficient HPV16 infection. Cell surface cyclophilin B (CyPB) facilitates conformational changes in capsid proteins, resulting in exposure of the L2 N-terminus. Inhibition of CyPB blocked HPV16 infection by inducing noninfectious internalization. Mutation of a putative CyP binding site present in HPV16 L2 yielded exposed L2 N-terminus in the absence of active CyP and bypassed the need for cell surface CyPB. However, this mutant was still sensitive to CyP inhibition and required CyP for completion of infection, probably after internalization. Taken together, these data suggest that CyP is required during two distinct steps of HPV16 infection. Identification of cell surface CyPB will facilitate the study of the complex events preceding internalization and adds a putative drug target for prevention of HPV-induced diseases.

Why so many sperm cells? Not only a possible means of mitigating the hazards inherent to human reproduction but also an indicator of an exaptation.

PubMed

Barlow, Peter W

2016-01-01

Redundancy-the excess of supply over necessity-has recently been proposed for human sperm cells. However, the apparent superfluity of cell numbers may be necessary in order to circumvent the hazards, many of which can be quantified, that can occur during the transition from gametogenesis within the testes to zygosis within the female reproductive tract. Sperm cell numbers are directly related to testicular volume, and it is owing to a redundancy, and the possible exaptation, of this latter parameter that a putative excess of sperm cells is perceived.

In vitro cell injury by oxidized low density lipoprotein involves lipid hydroperoxide-induced formation of alkoxyl, lipid, and peroxyl radicals.

PubMed Central

Coffey, M D; Cole, R A; Colles, S M; Chisolm, G M

1995-01-01

Mounting evidence supports current theories linking lipoprotein oxidation to atherosclerosis. We sought the cellular biochemical mechanism by which oxidized LDL inflicts cell injury. Inhibitors of candidate pathways of cell death were used to treat human fibroblast target cells exposed to oxidized LDL.. Ebselen, which degrades lipid hydroperoxides, inhibited oxidized LDL toxicity, consistent with our recent report that 7 beta-hydroperoxycholesterol (7 beta-OOH chol) is the major cytotoxin of oxidized LDL. Intracellular chelation of metal ions inhibited, while preloading cells with iron enhanced, toxicity, Inhibition of oxidized LDL and 7 beta-OOH chol toxicity by 2-keto-4-thiolmethyl butyric acid, a putative alkoxyl radical scavenger and by vitamin E, probucol and diphenylphenylenediamine, putative scavengers of peroxyl radicals was consistent with the involvement of these radicals in the lethal sequence. Cell death was thus postulated to occur due to lipid peroxidation via a sequence involving lipid hydroperoxide-induced, iron-mediated formation of alkoxyl, lipid, and peroxyl radicals. Pathways involving other reactive oxygen species, new protein synthesis, or altered cholesterol metabolism were considered less likely, since putative inhibitors failed to lessen toxicity. Understanding the mechanism of cell injury by oxidized LDL and its toxic moiety, 7 beta-OOH chol, may indicate specific interventions in the cell injury believed to accompany vascular lesion development. PMID:7560078

Tropomyosin-1: A Putative Tumor-Suppressor and a Biomarker of Human Breast Cancer

DTIC Science & Technology

2001-10-01

malignant cell types (Bhattacharya et al., 1990; Cooper cells, is significantly increased in TM1-expressing cells, et al., 1985, 1987; Hendricks and... penicillin and streptomycin. Cell lines derived from DT weretion is that DT cells are very potently transformed, and supplemented with appropriate drugs...10, 3097 --3112. Ben-Zc’ev A. (1997). Czur. Opit. Ce/l Bin!.. 9, 99 -108. Hendricks M atnd Weintraub H. (1981). Proc. Nall. Acead. Bhiattateharyat B

Tropomyosin-1, A Putative Tumor-Suppressor and a Biomarker of Human Breast Cancer

DTIC Science & Technology

2004-10-01

al., 1990; Cooper cells, is significantly increased in TMI-expressing cells, et al., 1985, 1987; Hendricks and Weintraub, 1981; without detectable...are very potently transformed, and penicillin and streptomycin. Cell lines derived from DT were supplemented with appropriate drugs, depending on the...3112. Ben-Ze’ev A. (1997). Curr. Opin. Cell Biol., 9, 99- 108. Hendricks M and Weintraub H. (1981). Proc. Natl. Acad. Bhattacharya B, Prasad GL

Structure and chromosomal localization of the human PD-1 gene (PDCD1)

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

Shinohara, T.; Ishida, Y.; Kawaichi, M.

1994-10-01

A cDNA encoding mouse PD-1, a member of the immunoglobulin superfamily, was previously isolated from apoptosis-induced cells by subtractive hybridization. To determine the structure and chromosomal location of the human PD-1 gene, we screened a human T cell cDNA library by mouse PD-1 probe and isolated a cDNA coding for the human PD-1 protein. The deduced amino acid sequence of human PD-1 was 60% identical to the mouse counterpart, and a putative tyrosine kinase-association motif was well conserved. The human PD-1 gene was mapped to 2q37.3 by chromosomal in situ hybridization. 7 refs., 3 figs.

Mapping of aldose reductase gene sequences to human chromosomes 1, 3, 7, 9, 11, and 13

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

Bateman, J.B.; Kojis, T.; Heinzmann, C.

1993-09-01

Aldose reductase (alditol:NAD(P)+ 1-oxidoreductase; EC 1.1.1.21) (AR) catalyzes the reduction of several aldehydes, including that of glucose, to the corresponding sugar alcohol. Using a complementary DNA clone encoding human AR, the authors mapped the gene sequences to human chromosomes 1, 3, 7, 9, 11, 13, 14, and 18 by somatic cell hybridization. By in situ hybridization analysis, sequences were localized to human chromosomes 1q32-q43, 3p12, 7q31-q35, 9q22, 11p14-p15, and 13q14-q21. As a putative functional AR gene has been mapped to chromosome 7 and a putative pseudogene to chromosome 3, the sequences on the other seven chromosomes may represent other activemore » genes, non-aldose reductase homologous sequences, or pseudogenes. 24 refs., 3 figs., 2 tabs.« less

Cryopreservation of putative pre-pubertal bovine spermatogonial stem cells by slow freezing.

PubMed

Kim, Ki-Jung; Lee, Yong-An; Kim, Bang-Jin; Kim, Yong-Hee; Kim, Byung-Gak; Kang, Hyun-Gu; Jung, Sang-Eun; Choi, Sun-Ho; Schmidt, Jonathan A; Ryu, Buom-Yong

2015-04-01

Development of techniques for the preservation of mammalian spermatogonial stem cells (SSCs) is a critical step in commercial application of SSC based technologies, including species preservation, amplification of agriculturally valuable germ lines, and human fertility preservations. The objective of this study was to develop an efficient cryopreservation protocol for preservation of bovine SSCs using a slow freezing technique. To maximize the efficiency of SSC cryopreservation, the effects of various methods (tissue vs. cell freezing) and cryoprotective agents (trehalose, sucrose, and polyethylene glycol [PEG]) were tested. Following thawing, cells were enriched for undifferentiated spermatogonia by differential plating and evaluated for recovery rate, proliferation capacity, and apoptosis. Additionally, putative stem cell activity was assessed using SSC xenotransplantation. The recovery rate, and proliferation capacity of undifferentiated spermatogonia were significantly greater for germ cells frozen using tissue freezing methods compared to cell freezing methods. Cryopreservation in the presence of 200 mM trehalose resulted in significantly greater recovery rate, proliferation capacity, and apoptosis of germ cells compared to control. Furthermore, cryopreservation using the tissue freezing method in the presence of 200 mM trehalose resulted in the production of colonies of donor-derived germ cells after xenotransplantation into recipient mouse testes, indicating putative stem cell function. Collectively, these data indicate that cryopreservation using tissue freezing methods in the presence of 200 mM trehalose is an efficient cryopreservation protocol for bovine SSCs. Copyright © 2015 Elsevier Inc. All rights reserved.

Massive NGS Data Analysis Reveals Hundreds Of Potential Novel Gene Fusions in Human Cell Lines.

PubMed

Gioiosa, Silvia; Bolis, Marco; Flati, Tiziano; Massini, Annalisa; Garattini, Enrico; Chillemi, Giovanni; Fratelli, Maddalena; Castrignanò, Tiziana

2018-06-01

Gene fusions derive from chromosomal rearrangements and the resulting chimeric transcripts are often endowed with oncogenic potential. Furthermore, they serve as diagnostic tools for the clinical classification of cancer subgroups with different prognosis and, in some cases, they can provide specific drug targets. So far, many efforts have been carried out to study gene fusion events occurring in tumor samples. In recent years, the availability of a comprehensive Next Generation Sequencing dataset for all the existing human tumor cell lines has provided the opportunity to further investigate these data in order to identify novel and still uncharacterized gene fusion events. In our work, we have extensively reanalyzed 935 paired-end RNA-seq experiments downloaded from "The Cancer Cell Line Encyclopedia" repository, aiming at addressing novel putative cell-line specific gene fusion events in human malignancies. The bioinformatics analysis has been performed by the execution of four different gene fusion detection algorithms. The results have been further prioritized by running a bayesian classifier which makes an in silico validation. The collection of fusion events supported by all of the predictive softwares results in a robust set of ∼ 1,700 in-silico predicted novel candidates suitable for downstream analyses. Given the huge amount of data and information produced, computational results have been systematized in a database named LiGeA. The database can be browsed through a dynamical and interactive web portal, further integrated with validated data from other well known repositories. Taking advantage of the intuitive query forms, the users can easily access, navigate, filter and select the putative gene fusions for further validations and studies. They can also find suitable experimental models for a given fusion of interest. We believe that the LiGeA resource can represent not only the first compendium of both known and putative novel gene fusion events in the catalog of all of the human malignant cell lines, but it can also become a handy starting point for wet-lab biologists who wish to investigate novel cancer biomarkers and specific drug targets.

Identification of the polypeptides encoded in the unassigned reading frames 2, 4, 4L, and 5 of human mitochondrial DNA.

PubMed Central

Mariottini, P; Chomyn, A; Riley, M; Cottrell, B; Doolittle, R F; Attardi, G

1986-01-01

In previous work, antibodies prepared against chemically synthesized peptides predicted from the DNA sequence were used to identify the polypeptides encoded in three of the eight unassigned reading frames (URFs) of human mitochondrial DNA (mtDNA). In the present study, this approach has been extended to other human mtDNA URFs. In particular, antibodies directed against the NH2-terminal octapeptide of the putative URF2 product specifically precipitated component 11 of the HeLa cell mitochondrial translation products, the reaction being inhibited by the specific peptide. Similarly, antibodies directed against the COOH-terminal nonapeptide of the putative URF4 product reacted specifically with components 4 and 5, and antibodies against a COOH-terminal heptapeptide of the presumptive URF4L product reacted specifically with component 26. Antibodies against the NH2-terminal heptapeptide of the putative product of URF5 reacted with component 1, but only to a marginal extent; however, the results of a trypsin fingerprinting analysis of component 1 point strongly to this component as being the authentic product of URF5. The polypeptide assignments to the mtDNA URFs analyzed here are supported by the relative electrophoretic mobilities of proteins 11, 4-5, 26, and 1, which are those expected for the molecular weights predicted from the DNA sequence for the products of URF2, URF4, URF4L, and URF5, respectively. With the present assignment, seven of the eight human mtDNA URFs have been shown to be expressed in HeLa cells. Images PMID:3456601

Ebola virus encodes a miR-155 analog to regulate importin-α5 expression.

PubMed

Liu, Yuanwu; Sun, Jing; Zhang, Hongwen; Wang, Mingming; Gao, George Fu; Li, Xiangdong

2016-10-01

The 2014 outbreak of Ebola virus caused more than 10,000 human deaths. Current knowledge of suitable drugs, clinical diagnostic biomarkers and molecular mechanisms of Ebola virus infection is either absent or insufficient. By screening stem-loop structures from the viral genomes of four virulence species, we identified a novel, putative viral microRNA precursor that is specifically expressed by the Ebola virus. The sequence of the microRNA precursor was further confirmed by mining the existing RNA-Seq database. Two putative mature microRNAs were predicted and subsequently validated in human cell lines. Combined with this prediction of the microRNA target, we identified importin-α5, which is a key regulator of interferon signaling following Ebola virus infection, as one putative target. We speculate that this microRNA could facilitate the evasion of the host immune system by the virus. Moreover, this microRNA might be a potential clinical therapeutic target or a diagnostic biomarker for Ebola virus.

Season of conception in rural Gambia affects DNA methylation at putative human metastable epialleles

USDA-ARS?s Scientific Manuscript database

Throughout most of the mammalian genome, genetically regulated developmental programming establishes diverse yet predictable epigenetic states across differentiated cells and tissues. At metastable epialleles (MEs), conversely, epigenotype is established stochastically in the early embryo then maint...

Organoid technology for brain and therapeutics research.

PubMed

Wang, Zhi; Wang, Shu-Na; Xu, Tian-Ying; Miao, Zhu-Wei; Su, Ding-Feng; Miao, Chao-Yu

2017-10-01

Brain is one of the most complex organs in human. The current brain research is mainly based on the animal models and traditional cell culture. However, the inherent species differences between humans and animals as well as the gap between organ level and cell level make it difficult to study human brain development and associated disorders through traditional technologies. Recently, the brain organoids derived from pluripotent stem cells have been reported to recapitulate many key features of human brain in vivo, for example recapitulating the zone of putative outer radial glia cells. Brain organoids offer a new platform for scientists to study brain development, neurological diseases, drug discovery and personalized medicine, regenerative medicine, and so on. Here, we discuss the progress, applications, advantages, limitations, and prospects of brain organoid technology in neurosciences and related therapeutics. © 2017 John Wiley & Sons Ltd.

Contribution of AmyA, an extracellular α-glucan degrading enzyme, to group A streptococcal host-pathogen interaction

PubMed Central

Shelburne, Samuel A.; Keith, David B.; Davenport, Michael T.; Beres, Stephen B.; Carroll, Ronan K.; Musser, James M.

2010-01-01

α-glucans such as starch and glycogen are abundant in the human oropharynx, the main site of group A Streptococcus (GAS) infection. However, the role in pathogenesis of GAS extracellular α-glucan binding and degrading enzymes is unknown. The serotype M1 GAS genome encodes two extracellular proteins putatively involved in α-glucan binding and degradation; pulA encodes a cell-wall anchored pullulanase and amyA encodes a freely secreted putative cyclomaltodextrin α-glucanotransferase. Genetic inactivation of amyA, but not pulA, abolished GAS α-glucan degradation. The ΔamyA strain had a slower rate of translocation across human pharyngeal epithelial cells. Consistent with this finding, the ΔamyA strain was less virulent following mouse mucosal challenge. Recombinant AmyA degraded α-glucans into β-cyclomaltodextrins that reduced pharyngeal cell transepithelial resistance, providing a physiologic explanation for the observed transepithelial migration phenotype. Higher amyA transcript levels were present in serotype M1 GAS strains causing invasive infection compared to strains causing pharyngitis. GAS proliferation in a defined α-glucan-containing medium was dependent on the presence of human salivary α-amylase. These data delineate the molecular mechanisms by which α-glucan degradation contributes to GAS host-pathogen interaction including how GAS employs human salivary α-amylase for its own metabolic benefit. PMID:19735442

Identification of the receptor tyrosine kinase AXL in breast cancer as a target for the human miR-34a microRNA

PubMed Central

Mackiewicz, Mark; Huppi, Konrad; Pitt, Jason J.; Dorsey, Tiffany H.; Ambs, Stefan

2012-01-01

The identification of molecular features that contribute to the progression of breast cancer can provide valuable insight into the pathogenesis of this disease. Deregulated microRNA expression represents one type of molecular event that has been associated with many different human cancers. In order to identify a miRNA/mRNA regulatory interaction that is biologically relevant to the triple-negative breast cancer genotype/phenotype, we initially conducted a miRNA profiling experiment to detect differentially expressed miRNAs in cell line models representing triple-negative (MDA-MB-231), ER+ (MCF7), and HER-2 over expressed (SK-BR-3) histotypes. We identified human miR-34a expression as being >3-fold down (from its median expression value across all cell lines) in MDA-MB-231 cells, and identified AXL as a putative mRNA target using multiple miRNA/target prediction algorithms. The miR-34a/AXL interaction was functionally characterized through ectopic over expression experiments with a miR-34a mimic in two independent triple-negative breast cancer cell lines. In reporter assays, miR-34a binds to its putative target site within the AXL 3′UTR to inhibit luciferase expression. We also observed degradation of AXL mRNA and decreased AXL protein levels, as well as cell signaling effects on AKT phosphorylation and phenotypic effects on cell migration. Finally, we present an inverse correlative trend in miR-34a and AXL expression for both cell line and patient tumor samples. PMID:21814748

Intracellular Localization Map of Human Herpesvirus 8 Proteins▿

PubMed Central

Sander, Gaby; Konrad, Andreas; Thurau, Mathias; Wies, Effi; Leubert, Rene; Kremmer, Elisabeth; Dinkel, Holger; Schulz, Thomas; Neipel, Frank; Stürzl, Michael

2008-01-01

Human herpesvirus 8 (HHV-8) is the etiological agent of Kaposi's sarcoma. We present a localization map of 85 HHV-8-encoded proteins in mammalian cells. Viral open reading frames were cloned with a Myc tag in expression plasmids, confirmed by full-length sequencing, and expressed in HeLa cells. Protein localizations were analyzed by immunofluorescence microscopy. Fifty-one percent of all proteins were localized in the cytoplasm, 22% were in the nucleus, and 27% were found in both compartments. Surprisingly, we detected viral FLIP (v-FLIP) in the nucleus and in the cytoplasm, whereas cellular FLIPs are generally localized exclusively in the cytoplasm. This suggested that v-FLIP may exert additional or alternative functions compared to cellular FLIPs. In addition, it has been shown recently that the K10 protein can bind to at least 15 different HHV-8 proteins. We noticed that K10 and only five of its 15 putative binding factors were localized in the nucleus when the proteins were expressed in HeLa cells individually. Interestingly, in coexpression experiments K10 colocalized with 87% (13 of 15) of its putative binding partners. Colocalization was induced by translocation of either K10 alone or both proteins. These results indicate active intracellular translocation processes in virus-infected cells. Specifically in this framework, the localization map may provide a useful reference to further elucidate the function of HHV-8-encoded genes in human diseases. PMID:18077714

Human spermatogonial stem cells display limited proliferation in vitro under mouse spermatogonial stem cell culture conditions.

PubMed

Medrano, Jose V; Rombaut, Charlotte; Simon, Carlos; Pellicer, Antonio; Goossens, Ellen

2016-11-01

To study the ability of human spermatogonial stem cells (hSSCs) to proliferate in vitro under mouse spermatogonial stem cell (mSSC) culture conditions. Experimental basic science study. Reproductive biology laboratory. Cryopreserved testicular tissue with normal spermatogenesis obtained from three donors subjected to orchiectomy due to a prostate cancer treatment. Testicular cells used to create in vitro cell cultures corresponding to the following groups: [1] unsorted human testicular cells, [2] differentially plated human testicular cells, and [3] cells enriched with major histocompatibility complex class 1 (HLA - )/epithelial cell surface antigen (EPCAM + ) in coculture with inactivated testicular feeders from the same patient. Analyses and characterization including immunocytochemistry and quantitative reverse-transcription polymerase chain reaction for somatic and germ cell markers, testosterone and inhibin B quantification, and TUNEL assay. Putative hSSCs appeared in singlets, doublets, or small groups of up to four cells in vitro only when testicular cells were cultured in StemPro-34 medium supplemented with glial cell line-derived neurotrophic factor (GDNF), leukemia inhibitory factor (LIF), basic fibroblast growth factor (bFGF), and epidermal growth factor (EGF). Fluorescence-activated cell sorting with HLA - /EPCAM + resulted in an enrichment of 27% VASA + /UTF1 + hSSCs, compared to 13% in unsorted controls. Coculture of sorted cells with inactivated testicular feeders gave rise to an average density of 112 hSSCs/cm 2 after 2 weeks in vitro compared with unsorted cells (61 hSSCs/cm 2 ) and differentially plated cells (49 hSSCS/cm 2 ). However, putative hSSCs rarely stained positive for the proliferation marker Ki67, and their presence was reduced to the point of almost disappearing after 4 weeks in vitro. We found that hSSCs show limited proliferation in vitro under mSSC culture conditions. Coculture of HLA - /EPCAM + sorted cells with testicular feeders improved the germ cell/somatic cell ratio. Copyright © 2016 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

A putative mesenchymal stem cells population isolated from adult human testes.

PubMed

Gonzalez, R; Griparic, L; Vargas, V; Burgee, K; Santacruz, P; Anderson, R; Schiewe, M; Silva, F; Patel, A

2009-08-07

Mesenchymal stem cells (MSCs) isolated from several adult human tissues are reported to be a promising tool for regenerative medicine. In order to broaden the array of tools for therapeutic application, we isolated a new population of cells from adult human testis termed gonadal stem cells (GSCs). GSCs express CD105, CD166, CD73, CD90, STRO-1 and lack hematopoietic markers CD34, CD45, and HLA-DR which are characteristic identifiers of MSCs. In addition, GSCs express pluripotent markers Oct4, Nanog, and SSEA-4. GSCs propagated for at least 64 population doublings and exhibited clonogenic capability. GSCs have a broad plasticity and the potential to differentiate into adipogenic, osteogenic, and chondrogenic cells. These studies demonstrate that GSCs are easily obtainable stem cells, have growth kinetics and marker expression similar to MSCs, and differentiate into mesodermal lineage cells. Therefore, GSCs may be a valuable tool for therapeutic applications.

Integrin-associated protein (CD47) is a putative mediator for soluble fibrinogen interaction with human red blood cells membrane.

PubMed

De Oliveira, S; Vitorino de Almeida, V; Calado, A; Rosário, H S; Saldanha, C

2012-03-01

Fibrinogen is a multifunctional plasma protein that plays a crucial role in several biological processes. Elevated fibrinogen induces erythrocyte hyperaggregation, suggesting an interaction between this protein and red blood cells (RBCs). Several studies support the concept that fibrinogen interacts with RBC membrane and this binding, due to specific and non-specific mechanisms, may be a trigger to RBC hyperaggregation in inflammation. The main goals of our work were to prove that human RBCs are able to specifically bind soluble fibrinogen, and identify membrane molecular targets that could be involved in this process. RBCs were first isolated from blood of healthy individuals and then separated in different age fractions by discontinuous Percoll gradients. After isolation RBC samples were incubated with human soluble fibrinogen and/or with a blocking antibody against CD47 followed by fluorescence confocal microscopy, flow cytometry acquisitions and zeta potential measurements. Our data show that soluble fibrinogen interacts with the human RBC membrane in an age-dependent manner, with younger RBCs interacting more with soluble fibrinogen than the older cells. Importantly, this interaction is abrogated in the presence of a specific antibody against CD47. Our results support a specific and age-dependent interaction of soluble fibrinogen with human RBC membrane; additionally we present CD47 as a putative mediator in this process. This interaction may contribute to RBC hyperaggregation in inflammation. Copyright © 2011 Elsevier B.V. All rights reserved.

Development of a conjunctival tissue substitute on the basis of plastic compressed collagen.

PubMed

Drechsler, C C; Kunze, A; Kureshi, A; Grobe, G; Reichl, S; Geerling, G; Daniels, J T; Schrader, S

2017-03-01

Ocular surface disorders, such as pterygium, cicatricial pemphigoid and external disruptions, can cause severe inflammation, scarring, fornix shortening as well as ankyloblepharon. Current treatments do not resolve these conditions sufficiently. The aim of this study was to evaluate clinical applicability and suitability of plastic compressed collagen to serve as a substrate for the expansion of human conjunctival epithelial cells in order to develop an epithelialized conjunctival substitute for fornix reconstruction. Human conjunctival epithelial cells were expanded on plastic compressed collagen gels. Epithelial cell characteristics were evaluated by haematoxylin and eosin staining, electron microscopy and cytokeratin expression. The expression of putative epithelial progenitor cell markers p63α, ABCG2 and CK15 was assessed by immunostaining. The proliferative capacity and clonal growth of the cells was evaluated before (P0) and after expansion (P1) on the plastic compressed collagen gels by colony forming efficiency assay. The potential clinical applicability of this gel substitutes was evaluated by assessment of their biomechanical properties as well as their surgical handling. Human conjunctival epithelial cells cultured on plastic and plastic compressed collagen gels formed a confluent cell layer and expressed CK19. The cells showed expression of the putative epithelial progenitor cell markers p63α, ABCG2 and CK15 and sustained colony forming ability. The compressed collagen gels showed a high ultimate tensile strength and elasticity and the surgical handling of gels was comparable to amniotic membrane. An epithelialized conjunctival tissue construct on the basis of compressed collagen might therefore be a promising alternative bioartificial tissue substitute for conjunctival reconstruction. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

FOXM1 Upregulation Is an Early Event in Human Squamous Cell Carcinoma and it Is Enhanced by Nicotine during Malignant Transformation

PubMed Central

Gemenetzidis, Emilios; Bose, Amrita; Riaz, Adeel M.; Chaplin, Tracy; Young, Bryan D.; Ali, Muhammad; Sugden, David; Thurlow, Johanna K.; Cheong, Sok-Ching; Teo, Soo-Hwang; Wan, Hong; Waseem, Ahmad; Parkinson, Eric K.; Fortune, Farida; Teh, Muy-Teck

2009-01-01

Background Cancer associated with smoking and drinking remains a serious health problem worldwide. The survival of patients is very poor due to the lack of effective early biomarkers. FOXM1 overexpression is linked to the majority of human cancers but its mechanism remains unclear in head and neck squamous cell carcinoma (HNSCC). Methodology/Principal Findings FOXM1 mRNA and protein expressions were investigated in four independent cohorts (total 75 patients) consisting of normal, premalignant and HNSCC tissues and cells using quantitative PCR (qPCR), expression microarray, immunohistochemistry and immunocytochemistry. Effect of putative oral carcinogens on FOXM1 transcriptional activity was dose-dependently assayed and confirmed using a FOXM1-specific luciferase reporter system, qPCR, immunoblotting and short-hairpin RNA interference. Genome-wide single nucleotide polymorphism (SNP) array was used to ‘trace’ the genomic instability signature pattern in 8 clonal lines of FOXM1-induced malignant human oral keratinocytes. Furthermore, acute FOXM1 upregulation in primary oral keratinocytes directly induced genomic instability. We have shown for the first time that overexpression of FOXM1 precedes HNSCC malignancy. Screening putative carcinogens in human oral keratinocytes surprisingly showed that nicotine, which is not perceived to be a human carcinogen, directly induced FOXM1 mRNA, protein stabilisation and transcriptional activity at concentrations relevant to tobacco chewers. Importantly, nicotine also augmented FOXM1-induced transformation of human oral keratinocytes. A centrosomal protein CEP55 and a DNA helicase/putative stem cell marker HELLS, both located within a consensus loci (10q23), were found to be novel targets of FOXM1 and their expression correlated tightly with HNSCC progression. Conclusions/Significance This study cautions the potential co-carcinogenic effect of nicotine in tobacco replacement therapies. We hypothesise that aberrant upregulation of FOXM1 may be inducing genomic instability through a program of malignant transformation involving the activation of CEP55 and HELLS which may facilitate aberrant mitosis and epigenetic modifications. Our finding that FOXM1 is upregulated early during oral cancer progression renders FOXM1 an attractive diagnostic biomarker for early cancer detection and its candidate mechanistic targets, CEP55 and HELLS, as indicators of malignant conversion and progression. PMID:19287496

Co-ordinated expression of MMP-2 and its putative activator, MT1-MMP, in human placentation.

PubMed

Bjørn, S F; Hastrup, N; Lund, L R; Danø, K; Larsen, J F; Pyke, C

1997-08-01

The spatial expression of mRNA for matrix metalloproteinase 2 (MMP-2), its putative activator, the membrane-type 1 matrix metalloproteinase (MT1-MMP), and the MMP-2 substrate type IV collagen was investigated in human placentas of both normal and tubal ectopic pregnancies and in cyclic endometrium using in-situ hybridization. Cytokeratin staining applied to adjacent sections was used to identify epithelial and trophoblast cells. In both normal and tubal pregnancies MT1-MMP, MMP-2 and type IV collagen mRNA were highly expressed and co-localized in the extravillous cytotrophoblasts of anchoring villi, in cytotrophoblasts that had penatrated into the placental bed and in cytotrophoblastic cell islands. In addition, the decidual cells of normal pregnancies in some areas co-expressed MT1-MMP and MMP-2 mRNA, with moderate signals for both components. Fibroblast-like stromal cells in tubal pregnancies were positive for MMP-2 mRNA but generally negative for MT1-MMP mRNA. The consistent co-localization of MT1-MMP with MMP-2 and type IV collagen in the same subset of cytotrophoblasts strongly suggests that all three components co-operate in the tightly regulated fetal invasion process. The co-expression of MT1-MMP and MMP-2 mRNA in some of the decidual cells indicates that these cells are also actively involved in the placentation process.

Distribution of efferent cholinergic terminals and alpha-bungarotoxin binding to putative nicotinic acetylcholine receptors in the human vestibular end-organs.

PubMed

Ishiyama, A; Lopez, I; Wackym, P A

1995-11-01

Although acetylcholine (ACh) has been identified as the primary neurotransmitter of the efferent vestibular system in most animals studied, no direct evidence exists that ACh is the efferent neurotransmitter of the human vestibular system. Choline acetyltransferase immunohistochemistry (ChATi), acetylcholinesterase (AChE) histochemistry, and alpha-bungarotoxin binding were used in human vestibular end-organs to address this question. ChATi and AChE activity was found in numerous bouton-type terminals contacting the basal area of type II vestibular hair cells and the afferent chalices surrounding type I hair cells; alpha-bungarotoxin binding suggested the presence of nicotinic acetylcholine receptors on type II vestibular hair cells and on the afferent chalices surrounding type I hair cells. This study provides evidence that the human efferent vestibular axons and terminals are cholinergic and that the receptors receiving this innervation may be nicotinic.

Stimulus selectivity and response latency in putative inhibitory and excitatory neurons of the primate inferior temporal cortex

PubMed Central

Mruczek, Ryan E. B.

2012-01-01

The cerebral cortex is composed of many distinct classes of neurons. Numerous studies have demonstrated corresponding differences in neuronal properties across cell types, but these comparisons have largely been limited to conditions outside of awake, behaving animals. Thus the functional role of the various cell types is not well understood. Here, we investigate differences in the functional properties of two widespread and broad classes of cells in inferior temporal cortex of macaque monkeys: inhibitory interneurons and excitatory projection cells. Cells were classified as putative inhibitory or putative excitatory neurons on the basis of their extracellular waveform characteristics (e.g., spike duration). Consistent with previous intracellular recordings in cortical slices, putative inhibitory neurons had higher spontaneous firing rates and higher stimulus-evoked firing rates than putative excitatory neurons. Additionally, putative excitatory neurons were more susceptible to spike waveform adaptation following very short interspike intervals. Finally, we compared two functional properties of each neuron's stimulus-evoked response: stimulus selectivity and response latency. First, putative excitatory neurons showed stronger stimulus selectivity compared with putative inhibitory neurons. Second, putative inhibitory neurons had shorter response latencies compared with putative excitatory neurons. Selectivity differences were maintained and latency differences were enhanced during a visual search task emulating more natural viewing conditions. Our results suggest that short-latency inhibitory responses are likely to sculpt visual processing in excitatory neurons, yielding a sparser visual representation. PMID:22933717

Comparative sequence analysis of a region on human chromosome 13q14, frequently deleted in B-cell chronic lymphocytic leukemia, and its homologous region on mouse chromosome 14.

PubMed

Kapanadze, B; Makeeva, N; Corcoran, M; Jareborg, N; Hammarsund, M; Baranova, A; Zabarovsky, E; Vorontsova, O; Merup, M; Gahrton, G; Jansson, M; Yankovsky, N; Einhorn, S; Oscier, D; Grandér, D; Sangfelt, O

2000-12-15

Previous studies have indicated the presence of a putative tumor suppressor gene on human chromosome 13q14, commonly deleted in patients with B-cell chronic lymphocytic leukemia (B-CLL). We have recently identified a minimally deleted region encompassing parts of two adjacent genes, termed LEU1 and LEU2 (leukemia-associated genes 1 and 2), and several additional transcripts. In addition, 50 kb centromeric to this region we have identified another gene, LEU5/RFP2. To elucidate further the complex genomic organization of this region, we have identified, mapped, and sequenced the homologous region in the mouse. Fluorescence in situ hybridization analysis demonstrated that the region maps to mouse chromosome 14. The overall organization and gene order in this region were found to be highly conserved in the mouse. Sequence comparison between the human deletion hotspot region and its homologous mouse region revealed a high degree of sequence conservation with an overall score of 74%. However, our data also show that in terms of transcribed sequences, only two of those, human LEU2 and LEU5/RFP2, are clearly conserved, strengthening the case for these genes as putative candidate B-CLL tumor suppressor genes.

Evidence of two distinct functionally specialized fibroblast lineages in breast stroma.

PubMed

Morsing, Mikkel; Klitgaard, Marie Christine; Jafari, Abbas; Villadsen, René; Kassem, Moustapha; Petersen, Ole William; Rønnov-Jessen, Lone

2016-11-03

The terminal duct lobular unit (TDLU) is the most dynamic structure in the human breast and the putative site of origin of human breast cancer. Although stromal cells contribute to a specialized microenvironment in many organs, this component remains largely understudied in the human breast. We here demonstrate the impact on epithelium of two lineages of breast stromal fibroblasts, one of which accumulates in the TDLU while the other resides outside the TDLU in the interlobular stroma. The two lineages are prospectively isolated by fluorescence activated cell sorting (FACS) based on different expression levels of CD105 and CD26. The characteristics of the two fibroblast lineages are assessed by immunocytochemical staining and gene expression analysis. The differentiation capacity of the two fibroblast populations is determined by exposure to specific differentiating conditions followed by analysis of adipogenic and osteogenic differentiation. To test whether the two fibroblast lineages are functionally imprinted by their site of origin, single cell sorted CD271 low /MUC1 high normal breast luminal epithelial cells are plated on fibroblast feeders for the observation of morphological development. Epithelial structure formation and polarization is shown by immunofluorescence and digitalized quantification of immunoperoxidase-stained cultures. Lobular fibroblasts are CD105 high /CD26 low while interlobular fibroblasts are CD105 low /CD26 high . Once isolated the two lineages remain phenotypically stable and functionally distinct in culture. Lobular fibroblasts have properties in common with bone marrow derived mesenchymal stem cells and they specifically convey growth and branching morphogenesis of epithelial progenitors. Two distinct functionally specialized fibroblast lineages exist in the normal human breast, of which the lobular fibroblasts have properties in common with mesenchymal stem cells and support epithelial growth and morphogenesis. We propose that lobular fibroblasts constitute a specialized microenvironment for human breast luminal epithelial progenitors, i.e. the putative precursors of breast cancer.

Human Lineage-Specific Transcriptional Regulation through GA-Binding Protein Transcription Factor Alpha (GABPa)

PubMed Central

Perdomo-Sabogal, Alvaro; Nowick, Katja; Piccini, Ilaria; Sudbrak, Ralf; Lehrach, Hans; Yaspo, Marie-Laure; Warnatz, Hans-Jörg; Querfurth, Robert

2016-01-01

A substantial fraction of phenotypic differences between closely related species are likely caused by differences in gene regulation. While this has already been postulated over 30 years ago, only few examples of evolutionary changes in gene regulation have been verified. Here, we identified and investigated binding sites of the transcription factor GA-binding protein alpha (GABPa) aiming to discover cis-regulatory adaptations on the human lineage. By performing chromatin immunoprecipitation-sequencing experiments in a human cell line, we found 11,619 putative GABPa binding sites. Through sequence comparisons of the human GABPa binding regions with orthologous sequences from 34 mammals, we identified substitutions that have resulted in 224 putative human-specific GABPa binding sites. To experimentally assess the transcriptional impact of those substitutions, we selected four promoters for promoter-reporter gene assays using human and African green monkey cells. We compared the activities of wild-type promoters to mutated forms, where we have introduced one or more substitutions to mimic the ancestral state devoid of the GABPa consensus binding sequence. Similarly, we introduced the human-specific substitutions into chimpanzee and macaque promoter backgrounds. Our results demonstrate that the identified substitutions are functional, both in human and nonhuman promoters. In addition, we performed GABPa knock-down experiments and found 1,215 genes as strong candidates for primary targets. Further analyses of our data sets link GABPa to cognitive disorders, diabetes, KRAB zinc finger (KRAB-ZNF), and human-specific genes. Thus, we propose that differences in GABPa binding sites played important roles in the evolution of human-specific phenotypes. PMID:26814189

Identification of estrogen-responsive genes using a genome-wide analysis of promoter elements for transcription factor binding sites.

PubMed

Kamalakaran, Sitharthan; Radhakrishnan, Senthil K; Beck, William T

2005-06-03

We developed a pipeline to identify novel genes regulated by the steroid hormone-dependent transcription factor, estrogen receptor, through a systematic analysis of upstream regions of all human and mouse genes. We built a data base of putative promoter regions for 23,077 human and 19,984 mouse transcripts from National Center for Biotechnology Information annotation and 8793 human and 6785 mouse promoters from the Data Base of Transcriptional Start Sites. We used this data base of putative promoters to identify potential targets of estrogen receptor by identifying estrogen response elements (EREs) in their promoters. Our program correctly identified EREs in genes known to be regulated by estrogen in addition to several new genes whose putative promoters contained EREs. We validated six genes (KIAA1243, NRIP1, MADH9, NME3, TPD52L, and ABCG2) to be estrogen-responsive in MCF7 cells using reverse transcription PCR. To allow for extensibility of our program in identifying targets of other transcription factors, we have built a Web interface to access our data base and programs. Our Web-based program for Promoter Analysis of Genome, PAGen@UIC, allows a user to identify putative target genes for vertebrate transcription factors through the analysis of their upstream sequences. The interface allows the user to search the human and mouse promoter data bases for potential target genes containing one or more listed transcription factor binding sites (TFBSs) in their upstream elements, using either regular expression-based consensus or position weight matrices. The data base can also be searched for promoters harboring user-defined TFBSs given as a consensus or a position weight matrix. Furthermore, the user can retrieve putative promoter sequences for any given gene together with identified TFBSs located on its promoter. Orthologous promoters are also analyzed to determine conserved elements.

Characterization of a microdissection library from human chromosome region 3p14

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

Bardenheuer, W.; Szymanski, S.; Lux, A.

1994-01-15

Structural alterations in human chromosome region 3p14-p23 resulting in the inactivation of one or more tumor suppressor genes are thought to play a pathogenic role in small cell lung cancer, renal cell carcinoma, and other human neoplasms. To identify putative tumor suppressor genes, 428 recombinant clones from a microdissection library specific for human chromosome region 3p14 were isolated and characterized. Ninety-six of these (22.5%) were human single-copy DNA sequences, 57 of which were unique sequence clones. Forty-four of these were mapped to the microdissected region using a cell hybrid mapping panel. Within this mapping panel, four probes detected two newmore » chromosome breakpoints that were previously indistinguishable from the translocation breakpoint t(3;8) in 3p14.2 in hereditary renal cell carcinoma. One probe maps to the homozygously deleted region of the small cell lung cancer cell line U2020. In addition, microdissection clones have been shown to be suitable for isolation of yeast artificial chromosomes. 52 refs., 3 figs., 2 tabs.« less

Impact of Procyanidins from Different Berries on Caspase 8 Activation in Colon Cancer.

PubMed

Minker, Carole; Duban, Livine; Karas, Daniel; Järvinen, Päivi; Lobstein, Annelise; Muller, Christian D

2015-01-01

The aim of this work is to identify which proapoptotic pathway is induced in human colon cancer cell lines, in contact with proanthocyanidins extracted from various berries. Proanthocyanidins (Pcys) extracted from 11 berry species are monitored for proapoptotic activities on two related human colon cancer cell lines: SW480-TRAIL-sensitive and SW620-TRAIL-resistant. Apoptosis induction is monitored by cell surface phosphatidylserine (PS) detection. Lowbush blueberry extract triggers the strongest activity. When tested on the human monocytic cell line THP-1, blueberry Pcys are less effective for PS externalisation and DNA fragmentation is absent, highlighting a specificity of apoptosis induction in gut cells. In Pcys-treated gut cell lines, caspase 8 (apoptosis extrinsic pathway) but not caspase 9 (apoptosis intrinsic pathway) is activated after 3 hours through P38 phosphorylation (90 min), emphasizing the potency of lowbush blueberry Pcys to eradicate gut TRAIL-resistant cancer cells. We highlight here that berries Pcys, especially lowbush blueberry Pcys, are of putative interest for nutritional chemoprevention of colorectal cancer in view of their apoptosis induction in a human colorectal cancer cell lines.

Characterization of ROS1 cDNA from a human glioblastoma cell line

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

Birchmeier, C.; O'Neill, K.; Riggs, M.

1990-06-01

The authors have isolated and characterized a human ROS1 cDNA from the glioblastoma cell line SW-1088. The cDNA, 8.3 kilobases long, has the potential to encode a transmembrane tyrosine-specific protein kinase with a predicted molecular mass of 259 kDa. The putative extracellular domain of ROS1 is homologous to the extracellular domain of the sevenless gene product from Drosophila. No comparable similarities in the extracellular domains were found between ROS1 and other receptor-type tyrosine kinases. Together, ROS1 and sevenless gene products define a distinct subclass of transmember tyrosine kinases.

MiR-21 suppresses the anticancer activities of curcumin by targeting PTEN gene in human non-small cell lung cancer A549 cells.

PubMed

Zhang, W; Bai, W; Zhang, W

2014-08-01

Curcumin, a natural phytochemical, exhibits potent anticancer activities. Here, we sought to determine the molecular mechanisms underlying the cytotoxic effects of curcumin against human non-small cell lung cancer (NSCLC) cells. MTT assay and annexin-V/PI staining were used to analyze the effects of curcumin on the proliferation and apoptosis of A549 cells. The expression of microRNA-21 in curcumin-treated A549 cells was measured by quantitative real-time polymerase chain reaction assay. The protein level of phosphatase and tensin homolog (PTEN), a putative target of microRNA-21, was determined by Western blot analysis. Transfection of A549 cells with microRNA-21 mimic or PTEN small interfering RNA was performed to modulate the expression of microRNA-21 and PTEN under the treatment of curcumin. Curcumin at 20-40 μM inhibited cell proliferation and induced apoptosis in A549 cells. Curcumin treatment produced a dose-dependent and significant (P < 0.05) suppression of microRNA-21 expression, compared to untreated A549 cells. Moreover, the protein level of PTEN, a putative target of microRNA-21, was significantly elevated in curcumin-treated A549 cells, as determined by Western blot analysis. Transfection of A549 cells with microRNA-21 mimic or PTEN small interfering RNA significantly (P < 0.05) reversed the growth suppression and apoptosis induction by curcumin, compared to corresponding controls. Our data suggest a novel molecular mechanism in which inhibition of microRNA-21 and upregulation of PTEN mediate the anticancer activities of curcumin in NSCLC cells. Suppression of microRNA-21 may thus have therapeutic benefits against this malignancy.

Investigations of the corneal epithelium in Veterinary Medicine: State of the art on corneal stem cells found in different mammalian species and their putative application.

PubMed

Patruno, M; Perazzi, A; Martinello, T; Gomiero, C; Maccatrozzo, L; Iacopetti, I

2018-05-08

The existence of progenitor cells that can readily differentiate into a specific cell type is a common cellular strategy for physiological tissue growth and repair mechanisms. In the mammalian cornea, many aspects regarding the nature and location of these cells are still unclear. In the human limbus (peripheral area of the cornea) progenitor cells have been found and characterized but in non-human mammals, the picture is not so clear. In this review, we examine current knowledge about the morphology of limbus and the localization of corneal epithelial stem cells in all species studied so far, comparing data with humans. We have also explored different research directions in the veterinary field in order to discuss the: i) currently used protocols and ii) best range of treatments for ocular pathologies in which corneal stem cells are involved. Copyright © 2018. Published by Elsevier Ltd.

Conjugative type IVb pilus recognizes lipopolysaccharide of recipient cells to initiate PAPI-1 pathogenicity island transfer in Pseudomonas aeruginosa

USDA-ARS?s Scientific Manuscript database

Pseudomonas aeruginosa pathogenicity island 1 (PAPI-1) is one of the largest genomic islands of this important opportunistic human pathogen. Previous studies have shown that PAPI-1 encodes several putative virulence factors, a major regulator of biofilm formation, and antibiotic-resistance traits, a...

Evidence of NK1 and NK2 Tachykinin Receptors and their Involvement in Histamine Release in a Murine Mast Cell Line

DTIC Science & Technology

1992-01-01

either human p ~ulmo(nary,. Delectaible in the absence of estrmcclular CaCI’. i’Potent 4.23ug/105 cells, or rat peritoneal mast cells. bousbesin...ABSTRACT (Maximum 200 words) Abstract-Binding of )kH substance P (SP) and histamine release were examined using a cloned mouse mast cell line SP binding...the cells with the NK2 antagonist peptide A reduced NKA-induced histamine release ID.Arg’,D.Phe’,D-Trp 0 3 .Leu t )nsu b s tance P , a putative SP

Mutational dynamics of the SARS coronavirus in cell culture and human populations isolated in 2003

PubMed Central

Vega, Vinsensius B; Ruan, Yijun; Liu, Jianjun; Lee, Wah Heng; Wei, Chia Lin; Se-Thoe, Su Yun; Tang, Kin Fai; Zhang, Tao; Kolatkar, Prasanna R; Ooi, Eng Eong; Ling, Ai Ee; Stanton, Lawrence W; Long, Philip M; Liu, Edison T

2004-01-01

Background The SARS coronavirus is the etiologic agent for the epidemic of the Severe Acute Respiratory Syndrome. The recent emergence of this new pathogen, the careful tracing of its transmission patterns, and the ability to propagate in culture allows the exploration of the mutational dynamics of the SARS-CoV in human populations. Methods We sequenced complete SARS-CoV genomes taken from primary human tissues (SIN3408, SIN3725V, SIN3765V), cultured isolates (SIN848, SIN846, SIN842, SIN845, SIN847, SIN849, SIN850, SIN852, SIN3408L), and five consecutive Vero cell passages (SIN2774_P1, SIN2774_P2, SIN2774_P3, SIN2774_P4, SIN2774_P5) arising from SIN2774 isolate. These represented individual patient samples, serial in vitro passages in cell culture, and paired human and cell culture isolates. Employing a refined mutation filtering scheme and constant mutation rate model, the mutation rates were estimated and the possible date of emergence was calculated. Phylogenetic analysis was used to uncover molecular relationships between the isolates. Results Close examination of whole genome sequence of 54 SARS-CoV isolates identified before 14th October 2003, including 22 from patients in Singapore, revealed the mutations engendered during human-to-Vero and Vero-to-human transmission as well as in multiple Vero cell passages in order to refine our analysis of human-to-human transmission. Though co-infection by different quasipecies in individual tissue samples is observed, the in vitro mutation rate of the SARS-CoV in Vero cell passage is negligible. The in vivo mutation rate, however, is consistent with estimates of other RNA viruses at approximately 5.7 × 10-6 nucleotide substitutions per site per day (0.17 mutations per genome per day), or two mutations per human passage (adjusted R-square = 0.4014). Using the immediate Hotel M contact isolates as roots, we observed that the SARS epidemic has generated four major genetic groups that are geographically associated: two Singapore isolates, one Taiwan isolate, and one North China isolate which appears most closely related to the putative SARS-CoV isolated from a palm civet. Non-synonymous mutations are centered in non-essential ORFs especially in structural and antigenic genes such as the S and M proteins, but these mutations did not distinguish the geographical groupings. However, no non-synonymous mutations were found in the 3CLpro and the polymerase genes. Conclusions Our results show that the SARS-CoV is well adapted to growth in culture and did not appear to undergo specific selection in human populations. We further assessed that the putative origin of the SARS epidemic was in late October 2002 which is consistent with a recent estimate using cases from China. The greater sequence divergence in the structural and antigenic proteins and consistent deletions in the 3' – most portion of the viral genome suggest that certain selection pressures are interacting with the functional nature of these validated and putative ORFs. PMID:15347429

Mitoxantrone is More Toxic than Doxorubicin in SH-SY5Y Human Cells: A 'Chemobrain' In Vitro Study.

PubMed

Almeida, Daniela; Pinho, Rita; Correia, Verónica; Soares, Jorge; Bastos, Maria de Lourdes; Carvalho, Félix; Capela, João Paulo; Costa, Vera Marisa

2018-05-05

The potential neurotoxic effects of anticancer drugs, like doxorubicin (DOX) and mitoxantrone (MTX; also used in multiple sclerosis), are presently important reasons for concern, following epidemiological data indicating that cancer survivors submitted to chemotherapy may suffer cognitive deficits. We evaluated the in vitro neurotoxicity of two commonly used chemotherapeutic drugs, DOX and MTX, and study their underlying mechanisms in the SH-SY5Y human neuronal cell model. Undifferentiated human SH-SY5Y cells were exposed to DOX or MTX (0.13, 0.2 and 0.5 μM) for 48 h and two cytotoxicity assays were performed, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) reduction and the neutral red (NR) incorporation assays. Phase contrast microphotographs, Hoechst, and acridine orange/ethidium bromide stains were performed. Mitochondrial membrane potential was also assessed. Moreover, putative protective drugs, namely the antioxidants N -acetyl-l-cysteine (NAC; 1 mM) and 100 μM tiron, the inhibitor of caspase-3/7, Ac-DEVD-CHO (100 μM), and a protein synthesis inhibitor, cycloheximide (CHX; 10 nM), were tested to prevent DOX- or MTX-induced toxicity. The MTT reduction assay was also done in differentiated SH-SY5Y cells following exposure to 0.2 μM DOX or MTX. MTX was more toxic than DOX in both cytotoxicity assays and according to the morphological analyses. MTX also evoked a higher number of apoptotic nuclei than DOX. Both drugs, at the 0.13 μM concentration, caused mitochondrial membrane potential depolarization after a 48-h exposure. Regarding the putative neuroprotectors, 1 mM NAC was not able to prevent the cytotoxicity caused by either drug. Notwithstanding, 100 μM tiron was capable of partially reverting MTX-induced cytotoxicity in the NR uptake assay. One hundred μM Ac-DEVD-CHO and 10 nM cycloheximide (CHX) also partially prevented the toxicity induced by DOX in the NR uptake assay. MTX was more toxic than DOX in differentiated SH-SY5Y cells, while MTX had similar toxicity in differentiated and undifferentiated SH-SY5Y cells. In fact, MTX was the most neurotoxic drug tested and the mechanisms involved seem dissimilar among drugs. Thus, its toxicity mechanisms need to be further investigated as to determine the putative neurotoxicity for multiple sclerosis and cancer patients.

UTF1, a Putative Marker for Spermatogonial Stem Cells in Stallions

PubMed Central

Jung, Heejun; Roser, Janet F.; Yoon, Minjung

2014-01-01

Spermatogonial stem cells (SSCs) continuously undergo self-renewal and differentiation to sustain spermatogenesis throughout adulthood in males. In stallions, SSCs may be used for the production of progeny from geldings after cryopreservation and therapy for infertile and subfertile stallions. Undifferentiated cell transcription factor 1 (UTF1) is a putative marker for undifferentiated spermatogonia in humans and rats. The main purposes of this study are to determine the following: 1) changes in the expression pattern of UTF1 at various reproductive stages of stallions, 2) subpopulations of spermatogonia that express UTF1. Testicular samples were collected and categorized based on the age of the horses as follows: pre-pubertal (<1 yr), pubertal (1–1.5 yr), post-pubertal (2–3 yr), and adult (4–8 yr). Western blot analysis was utilized to determine the cross-activity of the UTF1 antibody to horse testes tissues. Immunohistochemistry was conducted to investigate the UTF1 expression pattern in germ cells at different reproductive stages. Whole mount staining was applied to determine the subpopulation of UTF1-positive spermatogonia. Immunohistological analysis showed that most germ cells in the pre-pubertal and pubertal stages were immunolabeled with UTF1, whereas only a few germ cells in the basal compartment of the seminiferous tubule cross-sections of post-pubertal and adult tissues were UTF1-positive. No staining was observed in the Sertoli or Leydig cells at any reproductive stages. Whole mount staining showed that As, Apr, and chains of 4, 8, 16 Aal spermatogonia were immunolabeled with UTF1 in the post-pubertal stallion tubule. Isolated single germ cells were also immunolabeled with UTF1. In conclusion, UTF1 is expressed in undifferentiated spermatogonia, and its antibody can be used as a putative marker for SSCs in stallions. PMID:25272017

The mirror mechanism and mu rhythm in social development.

PubMed

Vanderwert, Ross E; Fox, Nathan A; Ferrari, Pier F

2013-04-12

Since the discovery of mirror neurons (MNs) in the monkey there has been a renewed interest in motor theories of cognitive and social development in humans by providing a potential neural mechanism underlying an action observation/execution matching system. It has been proposed that this system plays a fundamental role in the development of complex social and cognitive behaviors such as imitation and action recognition. In this review we discuss what is known about MNs from the work using single-cell recordings in the adult monkey, the evidence for the putative MN system in humans, and the extent to which research using electroencephalography (EEG) methods has contributed to our understanding of the development of these motor systems and their role in the social behaviors postulated by the MN hypothesis. We conclude with directions for future research that will improve our understanding of the putative human MN system and the functional role of MNs in social development. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Functions of MiRNA-128 on the regulation of head and neck squamous cell carcinoma growth and apoptosis.

PubMed

Hauser, Belinda; Zhao, Yuan; Pang, Xiaowu; Ling, Zhiqiang; Myers, Ernest; Wang, Paul; Califano, Joseph; Gu, Xinbin

2015-01-01

Incidence of head and neck squamous cell carcinoma (HNSCC) has continuously increased in past years while its survival rate has not been significantly improved. There is a critical need to better understand the genetic regulation of HNSCC tumorigenesis and progression. In this study, we comprehensively analyzed the function of miRNA-128 (miR-128) in the regulation of HNSCC growth and its putative targets in vitro and in vivo systems. The function and targets of miR-128 were investigated in human HNSCC cell lines (JHU-13 and JHU-22), which were stably transfected with the miR-128 gene using a lentiviral delivery system. The expression levels of miR-128 and its targeted proteins were analyzed with qRT-PCR, Western blotting and flow cytometry. The binding capacity of miRNA-128 to its putative targets was determined using a luciferase report assay. MTT, colony formation, and a tumor xenograft model further evaluated the effects of miR-128 on HNSCC growth. We generated two miR-128 stably transfected human HNSCC cell lines (JHU-13miR-128 and JHU-22miR-128). Enforced expression of miR-128 was detected in both cultured JHU-13miR-128 and JHU-22miR-128 cell lines, approximately seventeen to twenty folds higher than in vector control cell lines. miRNA-128 was able to bind with the 3'-untranslated regions of BMI-1, BAG-2, BAX, H3f3b, and Paip2 mRNAs, resulting in significant reduction of the targeted protein levels. We found that upregulated miR-128 expression significantly inhibited both JHU-13miR-128 and JHU-22miR-128 cell viability approximately 20 to 40%, and the JHU-22miR-128 tumor xenograft growth compared to the vector control groups. miR-128 acted as a tumor suppressor inhibiting the HNSCC growth by directly mediating the expression of putative targets. Our results provide a better understanding of miRNA-128 function and its potential targets, which may be valuable for developing novel diagnostic markers and targeted therapy.

Neuronal differentiation and long-term culture of the human neuroblastoma line SH-SY5Y.

PubMed

Constantinescu, R; Constantinescu, A T; Reichmann, H; Janetzky, B

2007-01-01

Parkinson's disease (PD) is the second most prevalent neurodegenerative disorder in industrialized countries. Present cell culture models for PD rely on either primary cells or immortal cell lines, neither of which allow for long-term experiments on a constant population, a crucial requisite for a realistic model of slowly progressing neurodegenerative diseases. We differentiated SH-SY5Y human dopaminergic neuroblastoma cells to a neuronal-like state in a perfusion culture system using a combination of retinoic acid and mitotic inhibitors. The cells could be cultivated for two months without the need for passage. We show, by various means, that the differentiated cells exhibit, at the molecular level, many neuronal properties not characteristic to the starting line. This approach opens the possibility to develop chronic models, in which the effect of perturbations and putative counteracting strategies can be monitored over long periods of time in a quasi-stable cell population.

Characterization of Plasmids in a Human Clinical Strain of Lactococcus garvieae

PubMed Central

Blanco, M. Mar; López-Campos, Guillermo H.; Cutuli, M. Teresa; Fernández-Garayzábal, José F.

2012-01-01

The present work describes the molecular characterization of five circular plasmids found in the human clinical strain Lactococcus garvieae 21881. The plasmids were designated pGL1-pGL5, with molecular sizes of 4,536 bp, 4,572 bp, 12,948 bp, 14,006 bp and 68,798 bp, respectively. Based on detailed sequence analysis, some of these plasmids appear to be mosaics composed of DNA obtained by modular exchange between different species of lactic acid bacteria. Based on sequence data and the derived presence of certain genes and proteins, the plasmid pGL2 appears to replicate via a rolling-circle mechanism, while the other four plasmids appear to belong to the group of lactococcal theta-type replicons. The plasmids pGL1, pGL2 and pGL5 encode putative proteins related with bacteriocin synthesis and bacteriocin secretion and immunity. The plasmid pGL5 harbors genes (txn, orf5 and orf25) encoding proteins that could be considered putative virulence factors. The gene txn encodes a protein with an enzymatic domain corresponding to the family actin-ADP-ribosyltransferases toxins, which are known to play a key role in pathogenesis of a variety of bacterial pathogens. The genes orf5 and orf25 encode two putative surface proteins containing the cell wall-sorting motif LPXTG, with mucin-binding and collagen-binding protein domains, respectively. These proteins could be involved in the adherence of L. garvieae to mucus from the intestine, facilitating further interaction with intestinal epithelial cells and to collagenous tissues such as the collagen-rich heart valves. To our knowledge, this is the first report on the characterization of plasmids in a human clinical strain of this pathogen. PMID:22768237

A putative lateral flagella of the cystic fibrosis pathogen Burkholderia dolosa regulates swimming motility and host cytokine production

PubMed Central

Clark, Bradley S.; Weatherholt, Molly; Renaud, Diane; Scott, David; LiPuma, John J.; Priebe, Gregory; Gerard, Craig

2018-01-01

Burkholderia dolosa caused an outbreak in the cystic fibrosis clinic at Boston Children’s Hospital and was associated with high mortality in these patients. This species is part of a larger complex of opportunistic pathogens known as the Burkholderia cepacia complex (Bcc). Compared to other species in the Bcc, B. dolosa is highly transmissible; thus understanding its virulence mechanisms is important for preventing future outbreaks. The genome of one of the outbreak strains, AU0158, revealed a homolog of the lafA gene encoding a putative lateral flagellin, which, in other non-Bcc species, is used for movement on solid surfaces, attachment to host cells, or movement inside host cells. Here, we analyzed the conservation of the lafA gene and protein sequences, which are distinct from those of the polar flagella, and found lafA homologs to be present in numerous β-proteobacteria but notably absent from most other Bcc species. A lafA deletion mutant in B. dolosa showed a greater swimming motility than wild-type due to an increase in the number of polar flagella, but did not appear to contribute to biofilm formation, host cell invasion, or murine lung colonization or persistence over time. However, the lafA gene was important for cytokine production in human peripheral blood mononuclear cells, suggesting it may have a role in recognition by the human immune response. PMID:29346379

The potential of induced pluripotent stem cells in models of neurological disorders: implications on future therapy.

PubMed

Crook, Jeremy Micah; Wallace, Gordon; Tomaskovic-Crook, Eva

2015-03-01

There is an urgent need for new and advanced approaches to modeling the pathological mechanisms of complex human neurological disorders. This is underscored by the decline in pharmaceutical research and development efficiency resulting in a relative decrease in new drug launches in the last several decades. Induced pluripotent stem cells represent a new tool to overcome many of the shortcomings of conventional methods, enabling live human neural cell modeling of complex conditions relating to aberrant neurodevelopment, such as schizophrenia, epilepsy and autism as well as age-associated neurodegeneration. This review considers the current status of induced pluripotent stem cell-based modeling of neurological disorders, canvassing proven and putative advantages, current constraints, and future prospects of next-generation culture systems for biomedical research and translation.

Presence of a novel exon 2E encoding a putative transmembrane protein in human IL-33 gene.

PubMed

Tominaga, Shin-ichi; Hayakawa, Morisada; Tsuda, Hidetoshi; Ohta, Satoshi; Yanagisawa, Ken

2013-01-18

Interleukin-33 (IL-33) is a dual-function molecule that regulates gene expression in nuclei and, as a cytokine, conveys proinflammatory signals from outside of cells via its specific receptor ST2L. There are still a lot of questions about localization and processing of IL-33 gene products. In the course of re-evaluating human IL-33 gene, we found distinct promoter usage depending on the cell type, similar to the case in the ST2 gene. Furthermore, we found a novel exon 2E in the conventional intron 2 whose open reading frame corresponded to a transmembrane protein of 131 amino acids. Dependence of exon 2E expression on differentiation of HUVEC cells is of great interest in relation to human IL-33 function. Copyright © 2012 Elsevier Inc. All rights reserved.

Measurement of the intracellular ph in human stomach cells: a novel approach to evaluate the gastric acid secretory potential of coffee beverages.

PubMed

Weiss, Carola; Rubach, Malte; Lang, Roman; Seebach, Elisabeth; Blumberg, Simone; Frank, Oliver; Hofmann, Thomas; Somoza, Veronika

2010-02-10

As the consumption of coffee beverages sometimes is reported to cause gastric irritation, for which an increased stomach acid secretion is one of the promoting factors, different processing technologies such as steam-treatment have been developed to reduce putative stomach irritating compounds. There is evidence-based data neither on the effect of detailed processing variations nor on individual coffee components affecting the proton secretory activity (PSA). This work aimed at developing a screening model suitable for investigating the effects of commercial coffee beverages and components thereof on human parietal cells. Human gastric cancer cells (HGT-1) were treated with reconstituted freeze-dried coffee beverages prepared from customary coffee products such as regular coffee (RC, n = 4), mild bean coffee (MBC, n = 5), stomach friendly coffee (SFC, n = 4), and SFC decaffeinated (SFCD, n = 3). PSA was analyzed by flow cytometry using the pH-sensitive dye SNARF-AM. Treatment of the cells with MBC did not result in a PSA different from RC treatment (p

Somatic Cells Become Cancer’s “Starter Dough” | Center for Cancer Research

Cancer.gov

Cancer stem cells (CSCs) is a term that sparks animated differences of opinions among researchers in the oncology community.  Much of the disagreement comes from the difficulty involved in isolating these cells and manipulating them ex vivo. When putative CSCs are isolated from clinical samples, researchers are unable to retrospectively identify the cell type that suffered the first oncogenic hit that led to tumorigenesis. Without this ability to make a clear pre- and post-cancer comparison, researchers are unable to characterize with confidence the origin and cellular properties of human CSCs.

Amplification of tumor inducing putative cancer stem cells (CSCs) by vitamin A/retinol from mammary tumors

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

Sharma, Rohit B.; Wang, Qingde; Khillan, Jaspal S., E-mail: khillan@pitt.edu

Highlights: •Vitamin A supports self renewal of putative CSCs from mammary tumors. •These cells exhibit impaired retinol metabolism into retinoic acid. •CSCs from mammary tumors differentiate into mammary specific cell lineages. •The cells express mammary stem cell specific CD29 and CD49f markers. •Putative CSCs form highly metastatic tumors in NOD SCID mouse. -- Abstract: Solid tumors contain a rare population of cancer stem cells (CSCs) that are responsible for relapse and metastasis. The existence of CSC however, remains highly controversial issue. Here we present the evidence for putative CSCs from mammary tumors amplified by vitamin A/retinol signaling. The cells exhibitmore » mammary stem cell specific CD29{sup hi}/CD49f{sup hi}/CD24{sup hi} markers, resistance to radiation and chemo therapeutic agents and form highly metastatic tumors in NOD/SCID mice. The cells exhibit indefinite self renewal as cell lines. Furthermore, the cells exhibit impaired retinol metabolism and do not express enzymes that metabolize retinol into retinoic acid. Vitamin A/retinol also amplified putative CSCs from breast cancer cell lines that form highly aggressive tumors in NOD SCID mice. The studies suggest that high purity putative CSCs can be isolated from solid tumors to establish patient specific cell lines for personalized therapeutics for pre-clinical translational applications. Characterization of CSCs will allow understanding of basic cellular and molecular pathways that are deregulated, mechanisms of tumor metastasis and evasion of therapies that has direct clinical relevance.« less

Impact of Procyanidins from Different Berries on Caspase 8 Activation in Colon Cancer

PubMed Central

Minker, Carole; Duban, Livine; Karas, Daniel; Järvinen, Päivi; Lobstein, Annelise; Muller, Christian D.

2015-01-01

Scope. The aim of this work is to identify which proapoptotic pathway is induced in human colon cancer cell lines, in contact with proanthocyanidins extracted from various berries. Methods and Results. Proanthocyanidins (Pcys) extracted from 11 berry species are monitored for proapoptotic activities on two related human colon cancer cell lines: SW480-TRAIL-sensitive and SW620-TRAIL-resistant. Apoptosis induction is monitored by cell surface phosphatidylserine (PS) detection. Lowbush blueberry extract triggers the strongest activity. When tested on the human monocytic cell line THP-1, blueberry Pcys are less effective for PS externalisation and DNA fragmentation is absent, highlighting a specificity of apoptosis induction in gut cells. In Pcys-treated gut cell lines, caspase 8 (apoptosis extrinsic pathway) but not caspase 9 (apoptosis intrinsic pathway) is activated after 3 hours through P38 phosphorylation (90 min), emphasizing the potency of lowbush blueberry Pcys to eradicate gut TRAIL-resistant cancer cells. Conclusion. We highlight here that berries Pcys, especially lowbush blueberry Pcys, are of putative interest for nutritional chemoprevention of colorectal cancer in view of their apoptosis induction in a human colorectal cancer cell lines. PMID:26180579

The Role of T-Cell Leukemia Translocation-Associated Gene Protein in Human Tumorigenesis and Osteoclastogenesis

PubMed Central

Kotake, Shigeru; Yago, Toru; Kawamoto, Manabu; Nanke, Yuki

2012-01-01

Synovial tissues of patients with rheumatoid arthritis (RA) include factors regulating bone resorption, such as receptor activator NF-κB ligand (RANKL), TNF-α, IL-6, IL-17, and IFN-γ. However, in addition to these cytokines, other factors expressed in synovial tissues may play a role in regulating bone resorption. In 2009, we demonstrated that novel peptides from T-cell leukemia translocation-associated gene (TCTA) protein expressed in synovial tissues from patients with RA inhibit human osteoclastogenesis, preventing cellular fusion via the interaction between TCTA protein and a putative counterpart molecule. Only a few studies on the role of TCTA protein have been reported. Genomic Southern blots demonstrated a reduced TCTA signal in three of four small cell lung cancer cell lines, suggesting the loss of one of the two copies of the gene. In the current paper, we reviewed the roles of TCTA protein in lung cancer cell lines and human osteoclastogenesis. PMID:22174563

From Hayflick to Walford: the role of T cell replicative senescence in human aging.

PubMed

Effros, Rita B

2004-06-01

The immunologic theory of aging, proposed more than 40 years ago by Roy Walford, suggests that the normal process of aging in man and in animals is pathogenetically related to faulty immunological processes. Since that time, research on immunological aging has undergone extraordinary expansion, leading to new information in areas spanning from molecular biology and cell signaling to large-scale clinical studies. Investigation in this area has also provided unexpected insights into HIV disease, many aspects of which represent accelerated immunological aging. This article describes the initial insights and vision of Roy Walford into one particular facet of human immunological aging, namely, the potential relevance of the well-studied human fibroblast replicative senescence model, initially developed by Leonard Hayflick, to cells of the immune system. Extensive research on T cell senescence in cell culture has now documented changes in vitro that closely mirror alterations occurring during in vivo aging in humans, underscoring the biological significance of T cell replicative senescence. Moreover, the inclusion of high proportions of putatively senescent T cells in the 'immune risk phenotype' that is associated with early mortality in octogenarians provides initial clinical confirmation of both the immunologic theory of aging and the role of the T cell Hayflick Limit in human aging, two areas of gerontological research pioneered by Roy Walford.

Pharmacological characterization of recombinant human and rat P2X receptor subtypes.

PubMed

Bianchi, B R; Lynch, K J; Touma, E; Niforatos, W; Burgard, E C; Alexander, K M; Park, H S; Yu, H; Metzger, R; Kowaluk, E; Jarvis, M F; van Biesen, T

1999-07-02

ATP functions as a fast neurotransmitter through the specific activation of a family of ligand-gated ion channels termed P2X receptors. In this report, six distinct recombinant P2X receptor subtypes were pharmacologically characterized in a heterologous expression system devoid of endogenous P2 receptor activity. cDNAs encoding four human P2X receptor subtypes (hP2X1, hP2X3, hP2X4, and hP2X7), and two rat P2X receptor subtypes (rP2X2 and rP2X3), were stably expressed in 1321N1 human astrocytoma cells. Furthermore, the rP2X2 and rP2X3 receptor subtypes were co-expressed in these same cells to form heteromultimeric receptors. Pharmacological profiles were determined for each receptor subtype, based on the activity of putative P2 ligands to stimulate Ca2+ influx. The observed potency and kinetics of each response was receptor subtype-specific and correlated with their respective electrophysiological properties. Each receptor subtype exhibited a distinct pharmacological profile, based on its respective sensitivity to nucleotide analogs, diadenosine polyphosphates and putative P2 receptor antagonists. Alphabeta-methylene ATP (alphabeta-meATP), a putative P2X receptor-selective agonist, was found to exhibit potent agonist activity only at the hP2X1, hP2X3 and rP2X3 receptor subtypes. Benzoylbenzoic ATP (BzATP, 2' and 3' mixed isomers), which has been reported to act as a P2X7 receptor-selective agonist, was least active at the rat and human P2X7 receptors, but was a potent (nM) agonist at hP2X1, rP2X3 and hP2X3 receptors. These data comprise a systematic examination of the functional pharmacology of P2X receptor activation.

The Putative Son's Attractiveness Alters the Perceived Attractiveness of the Putative Father.

PubMed

Prokop, Pavol

2015-08-01

A body of literature has investigated female mate choice in the pre-mating context (pre-mating sexual selection). Humans, however, are long-living mammals forming pair-bonds which sequentially produce offspring. Post-mating evaluations of a partner's attractiveness may thus significantly influence the reproductive success of men and women. I tested herein the theory that the attractiveness of putative sons provides extra information about the genetic quality of fathers, thereby influencing fathers' attractiveness across three studies. As predicted, facially attractive boys were more frequently attributed to attractive putative fathers and vice versa (Study 1). Furthermore, priming with an attractive putative son increased the attractiveness of the putative father with the reverse being true for unattractive putative sons. When putative fathers were presented as stepfathers, the effect of the boy's attractiveness on the stepfather's attractiveness was lower and less consistent (Study 2). This suggests that the presence of an attractive boy has the strongest effect on the perceived attractiveness of putative fathers rather than on non-fathers. The generalized effect of priming with beautiful non-human objects also exists, but its effect is much weaker compared with the effects of putative biological sons (Study 3). Overall, this study highlighted the importance of post-mating sexual selection in humans and suggests that the heritable attractive traits of men are also evaluated by females after mating and/or may be used by females in mate poaching.

Anticancer and apoptosis-inducing effects of quercetin in vitro and in vivo

PubMed Central

Hashemzaei, Mahmoud; Far, Amin Delarami; Yari, Arezoo; Heravi, Reza Entezari; Tabrizian, Kaveh; Taghdisi, Seyed Mohammad; Sadegh, Sarvenaz Ekhtiari; Tsarouhas, Konstantinos; Kouretas, Dimitrios; Tzanakakis, George; Nikitovic, Dragana; Anisimov, Nikita Yurevich; Spandidos, Demetrios A.; Tsatsakis, Aristides M.; Rezaee, Ramin

2017-01-01

The present study focused on the elucidation of the putative anticancer potential of quercetin. The anticancer activity of quercetin at 10, 20, 40, 80 and 120 µM was assessed in vitro by MMT assay in 9 tumor cell lines (colon carcinoma CT-26 cells, prostate adenocarcinoma LNCaP cells, human prostate PC3 cells, pheocromocytoma PC12 cells, estrogen receptor-positive breast cancer MCF-7 cells, acute lymphoblastic leukemia MOLT-4 T-cells, human myeloma U266B1 cells, human lymphoid Raji cells and ovarian cancer CHO cells). Quercetin was found to induce the apoptosis of all the tested cancer cell lines at the utilized concentrations. Moreover, quercetin significantly induced the apoptosis of the CT-26, LNCaP, MOLT-4 and Raji cell lines, as compared to control group (P<0.001), as demonstrated by Annexin V/PI staining. In in vivo experiments, mice bearing MCF-7 and CT-26 tumors exhibited a significant reduction in tumor volume in the quercetin-treated group as compared to the control group (P<0.001). Taken together, quercetin, a naturally occurring compound, exhibits anticancer properties both in vivo and in vitro. PMID:28677813

MiR-145 regulates PAK4 via the MAPK pathway and exhibits an antitumor effect in human colon cells

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

Wang, Zhigang; Zhang, Xiaoping; Yang, Zhili

2012-10-26

Highlights: Black-Right-Pointing-Pointer MiR-145 targets a putative binding site in the 3 Prime UTR of PAK4. Black-Right-Pointing-Pointer MiR-145 played an important role in inhibiting cell growth by directly targeting PAK4. Black-Right-Pointing-Pointer MiR-145 may function as tumor suppressors. -- Abstract: MicroRNAs (miRNAs) are regulators of numerous cellular events; accumulating evidence indicates that miRNAs play a key role in a wide range of biological functions, such as cellular proliferation, differentiation, and apoptosis in cancer. Down-regulated expression of miR-145 has been reported in colon cancer tissues and cell lines. The molecular mechanisms underlying miR-145 and the regulation of colon carcinogenesis remain unclear. In thismore » study, we investigated the levels of miR-145 in human colon cancer cells using qRT-PCR and found markedly decreased levels compared to normal epithelial cells. We identified PAK4 as a novel target of miR-145 using informatics screening. Additionally, we demonstrated that miR-145 targets a putative binding site in the 3 Prime UTR of PAK4 and that its abundance is inversely associated with miR-145 expression in colon cancer cells; we confirmed this relationship using the luciferase reporter assay. Furthermore, restoration of miR-145 by mimics in SW620 cells significantly attenuated cell growth in vitro, in accordance with the inhibitory effects induced by siRNA mediated knockdown of PAK4. Taken together, these findings demonstrate that miR-145 downregulates P-ERK expression by targeting PAK4 and leads to inhibition of tumor growth.« less

Enhancer connectome in primary human cells identifies target genes of disease-associated DNA elements

PubMed Central

Mumbach, Maxwell R; Satpathy, Ansuman T; Boyle, Evan A; Dai, Chao; Gowen, Benjamin G; Cho, Seung Woo; Nguyen, Michelle L; Rubin, Adam J; Granja, Jeffrey M; Kazane, Katelynn R; Wei, Yuning; Nguyen, Trieu; Greenside, Peyton G; Corces, M Ryan; Tycko, Josh; Simeonov, Dimitre R; Suliman, Nabeela; Li, Rui; Xu, Jin; Flynn, Ryan A; Kundaje, Anshul; Khavari, Paul A; Marson, Alexander; Corn, Jacob E; Quertermous, Thomas; Greenleaf, William J; Chang, Howard Y

2018-01-01

The challenge of linking intergenic mutations to target genes has limited molecular understanding of human diseases. Here we show that H3K27ac HiChIP generates high-resolution contact maps of active enhancers and target genes in rare primary human T cell subtypes and coronary artery smooth muscle cells. Differentiation of naive T cells into T helper 17 cells or regulatory T cells creates subtype-specific enhancer–promoter interactions, specifically at regions of shared DNA accessibility. These data provide a principled means of assigning molecular functions to autoimmune and cardiovascular disease risk variants, linking hundreds of noncoding variants to putative gene targets. Target genes identified with HiChIP are further supported by CRISPR interference and activation at linked enhancers, by the presence of expression quantitative trait loci, and by allele-specific enhancer loops in patient-derived primary cells. The majority of disease-associated enhancers contact genes beyond the nearest gene in the linear genome, leading to a fourfold increase in the number of potential target genes for autoimmune and cardiovascular diseases. PMID:28945252

Bovine brain ribonuclease is the functional homolog of human ribonuclease 1.

PubMed

Eller, Chelcie H; Lomax, Jo E; Raines, Ronald T

2014-09-19

Mounting evidence suggests that human pancreatic ribonuclease (RNase 1) plays important roles in vivo, ranging from regulating blood clotting and inflammation to directly counteracting tumorigenic cells. Understanding these putative roles has been pursued with continual comparisons of human RNase 1 to bovine RNase A, an enzyme that appears to function primarily in the ruminant gut. Our results imply a different physiology for human RNase 1. We demonstrate distinct functional differences between human RNase 1 and bovine RNase A. Moreover, we characterize another RNase 1 homolog, bovine brain ribonuclease, and find pronounced similarities between that enzyme and human RNase 1. We report that human RNase 1 and bovine brain ribonuclease share high catalytic activity against double-stranded RNA substrates, a rare quality among ribonucleases. Both human RNase 1 and bovine brain RNase are readily endocytosed by mammalian cells, aided by tight interactions with cell surface glycans. Finally, we show that both human RNase 1 and bovine brain RNase are secreted from endothelial cells in a regulated manner, implying a potential role in vascular homeostasis. Our results suggest that brain ribonuclease, not RNase A, is the true bovine homolog of human RNase 1, and provide fundamental insight into the ancestral roles and functional adaptations of RNase 1 in mammals. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

Identification of Primary Transcriptional Regulation of Cell Cycle-Regulated Genes upon DNA Damage

PubMed Central

Zhou, Tong; Chou, Jeff; Mullen, Thomas E.; Elkon, Rani; Zhou, Yingchun; Simpson, Dennis A.; Bushel, Pierre R.; Paules, Richard S.; Lobenhofer, Edward K.; Hurban, Patrick; Kaufmann, William K.

2007-01-01

The changes in global gene expression in response to DNA damage may derive from either direct induction or repression by transcriptional regulation or indirectly by synchronization of cells to specific cell cycle phases, such as G1 or G2. We developed a model that successfully estimated the expression levels of >400 cell cycle-regulated genes in normal human fibroblasts based on the proportions of cells in each phase of the cell cycle. By isolating effects on the gene expression associated with the cell cycle phase redistribution after genotoxin treatment, the direct transcriptional target genes were distinguished from genes for which expression changed secondary to cell synchronization. Application of this model to ionizing radiation (IR)-treated normal human fibroblasts identified 150 of 406 cycle-regulated genes as putative direct transcriptional targets of IR-induced DNA damage. Changes in expression of these genes after IR treatment derived from both direct transcriptional regulation and cell cycle synchronization. PMID:17404513

Cell surface expression of channel catfish leukocyte immune-type receptors (IpLITRs) and recruitment of both Src homology 2 domain-containing protein tyrosine phosphatase (SHP)-1 and SHP-2.

PubMed

Montgomery, Benjamin C S; Mewes, Jacqueline; Davidson, Chelsea; Burshtyn, Deborah N; Stafford, James L

2009-04-01

Channel catfish leukocyte immune-type receptors (IpLITRs) are immunoglobulin superfamily (IgSF) members believed to play a role in the control and coordination of cellular immune responses in teleost. Putative stimulatory and inhibitory IpLITRs are co-expressed by different types of catfish immune cells (e.g. NK cells, T cells, B cells, and macrophages) but their signaling potential has not been determined. Following cationic polymer-mediated transfections into human cell lines we examined the surface expression, tyrosine phosphorylation, and phosphatase recruitment potential of two types of putative inhibitory IpLITRs using 'chimeric' expression constructs and an epitope-tagged 'native' IpLITR. We also cloned and expressed the teleost Src homology 2 domain-containing protein tyrosine phosphatases (SHP)-1 and SHP-2 and examined their expression in adult tissues and developing zebrafish embryos. Co-immunoprecipitation experiments support the inhibitory signaling potential of distinct IpLITR-types that bound both SHP-1 and SHP-2 following the phosphorylation of tyrosine residues within their cytoplasmic tail (CYT) regions. Phosphatase recruitment by IpLITRs represents an important first step in understanding their influence on immune cell effector functions and suggests that certain inhibitory signaling pathways are conserved among vertebrates.

Cementogenic potential of multipotential mesenchymal stem cells purified from the human periodontal ligament.

PubMed

Torii, Daisuke; Konishi, Kiyoshi; Watanabe, Nobuyuki; Goto, Shinichi; Tsutsui, Takeki

2015-01-01

The periodontal ligament (PDL) consists of a group of specialized connective tissue fibers embedded in the alveolar bone and cementum that are believed to contain progenitors for mineralized tissue-forming cell lineages. These progenitors may contribute to regenerative cell therapy or tissue engineering methods aimed at recovery of tissue formation and functions lost in periodontal degenerative changes. Some reports using immortal clonal cell lines of cementoblasts, which are cells containing mineralized tissue-forming cell lineages, have shown that their phenotypic alteration and gene expression are associated with mineralization. Immortal, multipotential PDL-derived cell lines may be useful biological tools for evaluating differentiation-inducing agents. In this study, we confirmed the gene expression and mineralization potential of primary and immortal human PDL cells and characterized their immunophenotype. Following incubation with mineralization induction medium containing β-glycerophosphate, ascorbic acid, and dexamethasone, normal human PDL (Pel) cells and an immortal derivative line (Pelt) cells showed higher levels of mineralization compared with cells grown in normal growth medium. Both cell types were positive for putative surface antigens of mesenchymal cells (CD44, CD73, CD90, and CD105). They were also positive for stage-specific embryonic antigen-3, a marker of multipotential stem cells. Furthermore, PDL cells expressed cementum attachment protein and cementum protein 1 when cultured with recombinant human bone morphogenetic protein-2 or -7. The results suggest that normal and immortal human PDL cells contain multipotential mesenchymal stem cells with cementogenic potential.

A comparative study on efficiency of adult fibroblast, putative embryonic stem cell and lymphocyte as donor cells for production of handmade cloned embryos in goat and characterization of putative ntES cells obtained from these embryos.

PubMed

Dutta, Rahul; Malakar, Dhruba; Khate, Keviletsu; Sahu, Shailendra; Akshey, Yogesh; Mukesh, Manishi

2011-09-15

The main purpose of the experiment was to compare the efficiency of three cell types, namely adult fibroblast, putative embryonic stem (ES) cell, and lymphocyte, as donor cells for somatic cell nuclear transfer by handmade cloning in goats. The outcome clearly shows that putative embryonic stem cells, with a cleavage and blastocyst production rate of 74.69% ± 3.92 and 39.75% ± 3.86, respectively, performs better in comparison to adult fibroblast cell and lymphocyte. Between adult fibroblast cell and lymphocyte no statistically significant difference exists at P < 0.05. An overall cleavage and blastocyst formation rate of 67.41% ± 3.92 and 26.96% ± 3.86 was obtained using adult fibroblast donor cells. The study establishes beyond doubt the reprogrammability of lymphocyte by handmade cloning (HMC) protocol with a cleavage and blastocyst production rate of 56.47% ± 3.92 and 24.70% ± 3.86, respectively. PCR analysis of highly polymorphic 286 bp fragment of MHC II DRB genes of cloned embryos and three donor cells were performed to verify the cloned embryos. The amplified PCR products were subjected to SSCP to confirm their genetic identity. The karyotyping of the cloned embryos showed normal chromosomal status as expected in goat. Significantly, in the second stage of the experiment, the produced cloned embryos were successfully used to derive ntES-like cells. The rate of primary colony formation rate was 62.50% ± 4.62 for fibroblast donor cell derived embryos. The same was 60.60% ± 4.62 for putative ES donor cell derived embryos and 66.66% ± 4.62 for lymphocyte donor cell derived embryos, respectively. The putative ntES colonies were positively characterized for alkaline phosphatase, Oct-4, TRA-1-60, TRA-1-81, Sox-2, and Nanog by Immunocytochemistry and Reverse Transcription PCR. To further validate the stem ness, the produced putative ntES colonies were differentiated to embryoid bodies. Immunocytochemistry revealed that embryoid bodies expressed NESTIN specific for ectodermal lineage; GATA-4 for endodermal lineage and smooth muscle actin-I, and troponin-I specific for mesodermal lineage. The study has established an efficient protocol for putative ntES cell derivation from HMC embryos. It could be of substantial significance as patient specific ntES cells have proven therapeutic significance. Copyright © 2011 Elsevier Inc. All rights reserved.

Hematopoietic Colony Formation from Human Growth Factor-Dependent TF1 Cells and Human Cord Blood Myeloid Progenitor Cells Depends on SHP2 Phosphatase Function

PubMed Central

Etienne-Julan, Maryse; Gotoh, Akihiko; Braun, Stephen E.; Lu, Li; Cooper, Scott; Feng, Gen-Sheng; Li, Xing Jun

2013-01-01

The protein tyrosine phosphatase, SHP2, is widely expressed; however, previous studies demonstrated that hematopoietic cell development more stringently requires Shp2 expression compared to other tissues. Furthermore, somatic gain-of-function SHP2 mutants are commonly found in human myeloid leukemias. Given that pharmacologic inhibitors to SHP2 phosphatase activity are currently in development as putative antileukemic agents, we conducted a series of experiments examining the necessity of SHP2 phosphatase activity for human hematopoiesis. Anti-sense oligonucleotides to human SHP2 coding sequences reduced human cord blood- and human cell line, TF1-derived colony formation. Expression of truncated SHP2 bearing its Src homology 2 (SH2) domains, but lacking the phosphatase domain similarly reduced human cord blood- and TF1-derived colony formation. Mechanistically, expression of truncated SHP2 reduced the interaction between endogenous, full-length SHP2 with the adapter protein, Grb2. To verify the role of SHP2 phosphatase function in human hematopoietic cell development, human cord blood CD34+ cells were transduced with a leukemia-associated phosphatase gain-of-function SHP2 mutant or with a phosphatase dead SHP2 mutant, which indicated that increased phosphatase function enhanced, while decreased SHP2 phosphatase function reduced, human cord blood-derived colonies. Collectively, these findings indicate that SHP2 phosphatase function regulates human hematopoietic cell development and imply that the phosphatase component of SHP2 may serve as a pharmacologic target in human leukemias bearing increased SHP2 phosphatase activity. PMID:23082805

Hematopoietic colony formation from human growth factor-dependent TF1 cells and human cord blood myeloid progenitor cells depends on SHP2 phosphatase function.

PubMed

Broxmeyer, Hal E; Etienne-Julan, Maryse; Gotoh, Akihiko; Braun, Stephen E; Lu, Li; Cooper, Scott; Feng, Gen-Sheng; Li, Xing Jun; Chan, Rebecca J

2013-03-15

The protein tyrosine phosphatase, SHP2, is widely expressed; however, previous studies demonstrated that hematopoietic cell development more stringently requires Shp2 expression compared to other tissues. Furthermore, somatic gain-of-function SHP2 mutants are commonly found in human myeloid leukemias. Given that pharmacologic inhibitors to SHP2 phosphatase activity are currently in development as putative antileukemic agents, we conducted a series of experiments examining the necessity of SHP2 phosphatase activity for human hematopoiesis. Anti-sense oligonucleotides to human SHP2 coding sequences reduced human cord blood- and human cell line, TF1-derived colony formation. Expression of truncated SHP2 bearing its Src homology 2 (SH2) domains, but lacking the phosphatase domain similarly reduced human cord blood- and TF1-derived colony formation. Mechanistically, expression of truncated SHP2 reduced the interaction between endogenous, full-length SHP2 with the adapter protein, Grb2. To verify the role of SHP2 phosphatase function in human hematopoietic cell development, human cord blood CD34+ cells were transduced with a leukemia-associated phosphatase gain-of-function SHP2 mutant or with a phosphatase dead SHP2 mutant, which indicated that increased phosphatase function enhanced, while decreased SHP2 phosphatase function reduced, human cord blood-derived colonies. Collectively, these findings indicate that SHP2 phosphatase function regulates human hematopoietic cell development and imply that the phosphatase component of SHP2 may serve as a pharmacologic target in human leukemias bearing increased SHP2 phosphatase activity.

Functional significance of CD105-positive cells in papillary renal cell carcinoma.

PubMed

Matak, Damian; Brodaczewska, Klaudia K; Szczylik, Cezary; Koch, Irena; Myszczyszyn, Adam; Lipiec, Monika; Lewicki, Slawomir; Szymanski, Lukasz; Zdanowski, Robert; Czarnecka, Anna M

2017-01-05

CD105 was postulated as a renal cell carcinoma (RCC) stem cell marker, and CD133 as a putative RCC progenitor. Hypoxia, a natural microenvironment that prevails in tumors, was also incorporated into the study, especially in terms of the promotion of hypothetical stem-like cell properties. Within this study, we verify the existence of CD105+ and CD133+ populations in selected papillary subtype RCC (pRCC) cell lines. Both populations were analyzed for correlation with stem-like cell properties, such as stemness gene expression, and sphere and colony formation. For the preliminary analysis, several RCC cell lines were chosen (786-O, SMKT-R2, Caki-2, 796-P, ACHN, RCC6) and the control was human kidney cancer stem cells (HKCSC) and renal cells of embryonic origin (ASE-5063). Four cell lines were chosen for further investigation: Caki-2 (one of the highest numbers of CD105+ cells; primary origin), ACHN (a low number of CD105+ cells; metastatic origin), HKCSC (putative positive control), and ASE-5063 (additional control). In 769-P and RCC6, we could not detect a CD105+ population. Hypoxia variously affects pRCC cell growth, and mainly diminishes the stem-like properties of cells. Furthermore, we could not observe the correlation of CD105 and/or CD133 expression with the enhancement of stem-like properties. Based on this analysis, CD105/CD133 cannot be validated as cancer stem cell markers of pRCC cell lines.

BMP2 repression and optimized culture conditions promote human bone marrow-derived mesenchymal stem cell isolation.

PubMed

Kay, Alasdair Gawain; Dale, Tina Patricia; Akram, Khondoker Mehedi; Mohan, Param; Hampson, Karen; Maffulli, Nicola; Spiteri, Monica A; El Haj, Alicia Jennifer; Forsyth, Nicholas Robert

2015-01-01

Human mesenchymal stem cells (hMSC) are multipotent progenitor cells. We propose the optimization of hMSC isolation and recovery using the application of a controlled hypoxic environment. We evaluated oxygen, glucose and serum in the recovery of hMSC from bone marrow (BMhMSC). Colony forming units-fibroblastic, cell numbers, tri-lineage differentiation, immunofluorescence and microarray were used to confirm and characterize BMhMSC. In an optimized (2% O(2), 4.5 g/l glucose and 5% serum) environment both colony forming units-fibroblastic (p = 0.01) and cell numbers (p = 0.0001) were enhanced over standard conditions. Transcriptional analysis identified differential expression of bone morphogenetic protein 2 (BMP2) and, putatively, chemokine (C-X-C motif) receptor 2 (CXCR2) signaling pathways. We have detailed a potential milestone in the process of refinement of the BMhMSC isolation process.

Telocytes in meninges and choroid plexus.

PubMed

Popescu, B O; Gherghiceanu, M; Kostin, S; Ceafalan, L; Popescu, L M

2012-05-16

Telocytes (TCs) are a recently identified type of interstitial cells present in a wide variety of organs in humans and mammals (www.telocytes.com). They are characterized by a small cell body, but extremely long cell processes - telopodes (Tp), and a specific phenotype. TCs establish close contacts with blood capillaries, nerve fibers and stem cells. We report here identification of TCs by electron microscopy and immunofluorescence in rat meninges and choroid plexus/subventricular zone, in the vicinity of putative stem cells. The presence of TCs in brain areas involved in adult neurogenesis might indicate that they have a role in modulation of neural stem cell fate. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

A role for Lin28 in primordial germ cell development and germ cell malignancy

PubMed Central

West, Jason A.; Viswanathan, Srinivas R.; Yabuuchi, Akiko; Cunniff, Kerianne; Takeuchi, Ayumu; Park, In-Hyun; Sero, Julia E.; Zhu, Hao; Perez-Atayde, Antonio; Frazier, A. Lindsay; Surani, M. Azim; Daley, George Q.

2009-01-01

The rarity and inaccessibility of the earliest primordial germ cells (PGCs) in the mouse embryo thwarts efforts to investigate molecular mechanisms of germ cell specification. Stella marks the minute founder population of the germ lineage1,2. Here we differentiate mouse embryonic stem cells (ESCs) carrying a Stella transgenic reporter into putative PGCs in vitro. The Stella+ cells possess a transcriptional profile similar to embryo-derived PGCs, and like their counterparts in vivo, lose imprints in a time-dependent manner. Using inhibitory RNAs to screen candidate genes for effects on the development of Stella+ cells in vitro, we discovered that Lin28, a negative regulator of let-7 microRNA processing3-6, is essential for proper PGC development. We further show that Blimp1, a let-7 target and a master regulator of PGC specification7-9, can rescue the effect of Lin28-deficiency during PGC development, thereby establishing a mechanism of action for Lin28 during PGC specification. Over-expression of Lin28 promotes formation of Stella+ cells in vitro and PGCs in chimeric embryos, and is associated with human germ cell tumours. The differentiation of putative PGCs from ESCs in vitro recapitulates the early stages of gamete development in vivo, and provides an accessible system for discovering novel genes involved in germ cell development and malignancy. PMID:19578360

SHP-1 is directly activated by the aryl hydrocarbon receptor and regulates BCL-6 in the presence of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)

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

Phadnis-Moghe, Ashwini S.; Li, Jinpeng

2016-11-01

The environmental contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), which is a strong AHR agonist, causes significant suppression of human B cell activation and differentiation. The current studies describe the identification of Src homology phosphatase 1 (SHP-1) encoded by the gene PTPN6 as a putative regulator of TCDD-mediated suppression of B cell activation. Shp-1 was initially identified through a genome-wide analysis of AHR binding in mouse B cells in the presence of TCDD. The binding of AHR to the PTPN6 promoter was further confirmed using electrophoretic mobility shift assays in which, specific binding of AHR was detected at four putative DRE sites within PTPN6more » promoter. Time-course measurements performed in human B cells highlighted a significant increase in SHP-1 mRNA and protein levels in the presence of TCDD. The changes in the protein levels of SHP-1 were also observed in a TCDD concentration-dependent manner. The increase in SHP-1 levels was also seen to occur due to a change in early signaling events in the presence of TCDD. We have shown that BCL-6 regulates B cell activation by repressing activation marker CD80 in the presence of TCDD. TCDD-treatment led to a significant increase in the double positive (SHP-1{sup hi} BCL-6{sup hi}) population. Interestingly, treatment of naïve human B cells with SHP-1 inhibitor decreased BCL-6 protein levels suggesting possible regulation of BCL-6 by SHP-1 for the first time. Collectively, these results suggest that SHP-1 is regulated by AHR in the presence of TCDD and may, in part through BCL-6, regulate TCDD-mediated suppression of human B cell activation. - Highlights: • SHP-1 encoded by the gene PTPN6 is directly activated by the AHR. • AHR binds to dioxin response elements within the SHP-1 promoter in a TCDD-inducible manner. • TCDD-mediated increase in SHP-1 levels is observed in primary human B cells. • Higher SHP-1 levels help in maintaining high BCL-6 levels in the presence of TCDD. • In the presence of SHP-1 inhibitor, decreased BCL-6 levels are observed.« less

Stem cells in clinical practice: applications and warnings.

PubMed

Lodi, Daniele; Iannitti, Tommaso; Palmieri, Beniamino

2011-01-17

Stem cells are a relevant source of information about cellular differentiation, molecular processes and tissue homeostasis, but also one of the most putative biological tools to treat degenerative diseases. This review focuses on human stem cells clinical and experimental applications. Our aim is to take a correct view of the available stem cell subtypes and their rational use in the medical area, with a specific focus on their therapeutic benefits and side effects. We have reviewed the main clinical trials dividing them basing on their clinical applications, and taking into account the ethical issue associated with the stem cell therapy. We have searched Pubmed/Medline for clinical trials, involving the use of human stem cells, using the key words "stem cells" combined with the key words "transplantation", "pathology", "guidelines", "properties" and "risks". All the relevant clinical trials have been included. The results have been divided into different categories, basing on the way stem cells have been employed in different pathological conditions.

Discovery of a New Human Polyomavirus Associated with Trichodysplasia Spinulosa in an Immunocompromized Patient

PubMed Central

van der Meijden, Els; Janssens, René W. A.; Lauber, Chris; Bouwes Bavinck, Jan Nico; Gorbalenya, Alexander E.; Feltkamp, Mariet C. W.

2010-01-01

The Polyomaviridae constitute a family of small DNA viruses infecting a variety of hosts. In humans, polyomaviruses can cause infections of the central nervous system, urinary tract, skin, and possibly the respiratory tract. Here we report the identification of a new human polyomavirus in plucked facial spines of a heart transplant patient with trichodysplasia spinulosa, a rare skin disease exclusively seen in immunocompromized patients. The trichodysplasia spinulosa-associated polyomavirus (TSV) genome was amplified through rolling-circle amplification and consists of a 5232-nucleotide circular DNA organized similarly to known polyomaviruses. Two putative “early” (small and large T antigen) and three putative “late” (VP1, VP2, VP3) genes were identified. The TSV large T antigen contains several domains (e.g. J-domain) and motifs (e.g. HPDKGG, pRb family-binding, zinc finger) described for other polyomaviruses and potentially involved in cellular transformation. Phylogenetic analysis revealed a close relationship of TSV with the Bornean orangutan polyomavirus and, more distantly, the Merkel cell polyomavirus that is found integrated in Merkel cell carcinomas of the skin. The presence of TSV in the affected patient's skin was confirmed by newly designed quantitative TSV-specific PCR, indicative of a viral load of 105 copies per cell. After topical cidofovir treatment, the lesions largely resolved coinciding with a reduction in TSV load. PCR screening demonstrated a 4% prevalence of TSV in an unrelated group of immunosuppressed transplant recipients without apparent disease. In conclusion, a new human polyomavirus was discovered and identified as the possible cause of trichodysplasia spinulosa in immunocompromized patients. The presence of TSV also in clinically unaffected individuals suggests frequent virus transmission causing subclinical, probably latent infections. Further studies have to reveal the impact of TSV infection in relation to other populations and diseases. PMID:20686659

Bordetella pertussis Proteins Dominating the Major Histocompatibility Complex Class II-Presented Epitope Repertoire in Human Monocyte-Derived Dendritic Cells

PubMed Central

Stenger, Rachel M.; Meiring, Hugo D.; Kuipers, Betsy; Poelen, Martien; van Gaans-van den Brink, Jacqueline A. M.; Boog, Claire J. P.; de Jong, Ad P. J. M.

2014-01-01

Knowledge of naturally processed Bordetella pertussis-specific T cell epitopes may help to increase our understanding of the basis of cell-mediated immune mechanisms to control this reemerging pathogen. Here, we elucidate for the first time the dominant major histocompatibility complex (MHC) class II-presented B. pertussis CD4+ T cell epitopes, expressed on human monocyte-derived dendritic cells (MDDC) after the processing of whole bacterial cells by use of a platform of immunoproteomics technology. Pertussis epitopes identified in the context of HLA-DR molecules were derived from two envelope proteins, i.e., putative periplasmic protein (PPP) and putative peptidoglycan-associated lipoprotein (PAL), and from two cytosolic proteins, i.e., 10-kDa chaperonin groES protein (groES) and adenylosuccinate synthetase (ASS). No epitopes were detectable from known virulence factors. CD4+ T cell responsiveness in healthy adults against peptide pools representing epitope regions or full proteins confirmed the immunogenicity of PAL, PPP, groES, and ASS. Elevated lymphoproliferative activity to PPP, groES, and ASS in subjects within a year after the diagnosis of symptomatic pertussis suggested immunogenic exposure to these proteins during clinical infection. The PAL-, PPP-, groES-, and ASS-specific responses were associated with secretion of functional Th1 (tumor necrosis factor alpha [TNF-α] and gamma interferon [IFN-γ]) and Th2 (interleukin 5 [IL-5] and IL-13) cytokines. Relative paucity in the natural B. pertussis epitope display of MDDC, not dominated by epitopes from known protective antigens, can interfere with the effectiveness of immune recognition of B. pertussis. A more complete understanding of hallmarks in B. pertussis-specific immunity may advance the design of novel immunological assays and prevention strategies. PMID:24599530

Bordetella pertussis proteins dominating the major histocompatibility complex class II-presented epitope repertoire in human monocyte-derived dendritic cells.

PubMed

Stenger, Rachel M; Meiring, Hugo D; Kuipers, Betsy; Poelen, Martien; van Gaans-van den Brink, Jacqueline A M; Boog, Claire J P; de Jong, Ad P J M; van Els, Cécile A C M

2014-05-01

Knowledge of naturally processed Bordetella pertussis-specific T cell epitopes may help to increase our understanding of the basis of cell-mediated immune mechanisms to control this reemerging pathogen. Here, we elucidate for the first time the dominant major histocompatibility complex (MHC) class II-presented B. pertussis CD4(+) T cell epitopes, expressed on human monocyte-derived dendritic cells (MDDC) after the processing of whole bacterial cells by use of a platform of immunoproteomics technology. Pertussis epitopes identified in the context of HLA-DR molecules were derived from two envelope proteins, i.e., putative periplasmic protein (PPP) and putative peptidoglycan-associated lipoprotein (PAL), and from two cytosolic proteins, i.e., 10-kDa chaperonin groES protein (groES) and adenylosuccinate synthetase (ASS). No epitopes were detectable from known virulence factors. CD4(+) T cell responsiveness in healthy adults against peptide pools representing epitope regions or full proteins confirmed the immunogenicity of PAL, PPP, groES, and ASS. Elevated lymphoproliferative activity to PPP, groES, and ASS in subjects within a year after the diagnosis of symptomatic pertussis suggested immunogenic exposure to these proteins during clinical infection. The PAL-, PPP-, groES-, and ASS-specific responses were associated with secretion of functional Th1 (tumor necrosis factor alpha [TNF-α] and gamma interferon [IFN-γ]) and Th2 (interleukin 5 [IL-5] and IL-13) cytokines. Relative paucity in the natural B. pertussis epitope display of MDDC, not dominated by epitopes from known protective antigens, can interfere with the effectiveness of immune recognition of B. pertussis. A more complete understanding of hallmarks in B. pertussis-specific immunity may advance the design of novel immunological assays and prevention strategies.

PilY1 Promotes Legionella pneumophila Infection of Human Lung Tissue Explants and Contributes to Bacterial Adhesion, Host Cell Invasion, and Twitching Motility.

PubMed

Hoppe, Julia; Ünal, Can M; Thiem, Stefanie; Grimpe, Louisa; Goldmann, Torsten; Gaßler, Nikolaus; Richter, Matthias; Shevchuk, Olga; Steinert, Michael

2017-01-01

Legionnaires' disease is an acute fibrinopurulent pneumonia. During infection Legionella pneumophila adheres to the alveolar lining and replicates intracellularly within recruited macrophages. Here we provide a sequence and domain composition analysis of the L. pneumophila PilY1 protein, which has a high homology to PilY1 of Pseudomonas aeruginosa . PilY1 proteins of both pathogens contain a von Willebrand factor A (vWFa) and a C-terminal PilY domain. Using cellular fractionation, we assigned the L. pneumophila PilY1 as an outer membrane protein that is only expressed during the transmissive stationary growth phase. PilY1 contributes to infection of human lung tissue explants (HLTEs). A detailed analysis using THP-1 macrophages and A549 lung epithelial cells revealed that this contribution is due to multiple effects depending on host cell type. Deletion of PilY1 resulted in a lower replication rate in THP-1 macrophages but not in A549 cells. Further on, adhesion to THP-1 macrophages and A549 epithelial cells was decreased. Additionally, the invasion into non-phagocytic A549 epithelial cells was drastically reduced when PilY1 was absent. Complementation variants of a PilY1-negative mutant revealed that the C-terminal PilY domain is essential for restoring the wild type phenotype in adhesion, while the putatively mechanosensitive vWFa domain facilitates invasion into non-phagocytic cells. Since PilY1 also promotes twitching motility of L. pneumophila , we discuss the putative contribution of this newly described virulence factor for bacterial dissemination within infected lung tissue.

PXR-dependent induction of human CYP3A4 gene expression by organochlorine pesticides.

PubMed

Coumoul, Xavier; Diry, Monique; Barouki, Robert

2002-11-15

OCP are xenobiotics which display various toxic effects on animal and human health. One of their effects is to bind and activate estrogen receptor alpha (ERalpha). We have previously studied the down-regulation of induced CYP1A1 (cytochrome P450) expression by this class of molecules in mammary carcinoma cells and shown the importance of ERalpha in this process. However, an alternative mechanism was suggested by those experiments in hepatoma cells. In this study, we have performed Northern blot and transient transfection assays in various cell lines and shown that OCP activate human pregnane X receptor (PXR) and subsequent CYP3A4 mRNA expression. This effect is mediated by the distal xenobiotic responsive element modulator of the promoter. The induction of CYP3A4 by OCP was dose-dependent within the 1-10 microM range. The data suggest that chronic exposure to OCP could alter a major metabolite pathway in human liver and putatively modify the pharmacokinetics of drugs and pollutants.

Global reorganisation of cis-regulatory units upon lineage commitment of human embryonic stem cells

PubMed Central

Freire-Pritchett, Paula; Schoenfelder, Stefan; Várnai, Csilla; Wingett, Steven W; Cairns, Jonathan; Collier, Amanda J; García-Vílchez, Raquel; Furlan-Magaril, Mayra; Osborne, Cameron S; Fraser, Peter; Rugg-Gunn, Peter J; Spivakov, Mikhail

2017-01-01

Long-range cis-regulatory elements such as enhancers coordinate cell-specific transcriptional programmes by engaging in DNA looping interactions with target promoters. Deciphering the interplay between the promoter connectivity and activity of cis-regulatory elements during lineage commitment is crucial for understanding developmental transcriptional control. Here, we use Promoter Capture Hi-C to generate a high-resolution atlas of chromosomal interactions involving ~22,000 gene promoters in human pluripotent and lineage-committed cells, identifying putative target genes for known and predicted enhancer elements. We reveal extensive dynamics of cis-regulatory contacts upon lineage commitment, including the acquisition and loss of promoter interactions. This spatial rewiring occurs preferentially with predicted changes in the activity of cis-regulatory elements and is associated with changes in target gene expression. Our results provide a global and integrated view of promoter interactome dynamics during lineage commitment of human pluripotent cells. DOI: http://dx.doi.org/10.7554/eLife.21926.001 PMID:28332981

An ankyrin-like protein with transmembrane domains is specifically lost after oncogenic transformation of human fibroblasts.

PubMed

Jaquemar, D; Schenker, T; Trueb, B

1999-03-12

We have identified a novel transformation-sensitive mRNA, which is present in cultured fibroblasts but is lacking in SV40 transformed cells as well as in many mesenchymal tumor cell lines. The corresponding gene is located on human chromosome 8 in band 8q13. The open reading frame of the mRNA encodes a protein of 1119 amino acids forming two distinct domains. The N-terminal domain consists of 18 repeats that are related to the cytoskeletal protein ankyrin. The C-terminal domain contains six putative transmembrane segments that resemble many ion channels. This overall structure is reminiscent of TRP-like proteins that function as store-operated calcium channels. The novel protein with an Mr of 130 kDa is expressed at a very low level in human fibroblasts and at a moderate level in liposarcoma cells. Overexpression in eukaryotic cells appears to interfere with normal growth, suggesting that it might play a direct or indirect role in signal transduction and growth control.

Reprogramming human gallbladder cells into insulin-producing β-like cells

PubMed Central

Benedetti, Eric; Wang, Yuhan; Pelz, Carl; Schug, Jonathan; Kaestner, Klaus H.; Grompe, Markus

2017-01-01

The gallbladder and cystic duct (GBCs) are parts of the extrahepatic biliary tree and share a common developmental origin with the ventral pancreas. Here, we report on the very first genetic reprogramming of patient-derived human GBCs to β-like cells for potential autologous cell replacement therapy for type 1 diabetes. We developed a robust method for large-scale expansion of human GBCs ex vivo. GBCs were reprogrammed into insulin-producing pancreatic β-like cells by a combined adenoviral-mediated expression of hallmark pancreatic endocrine transcription factors PDX1, MAFA, NEUROG3, and PAX6 and differentiation culture in vitro. The reprogrammed GBCs (rGBCs) strongly induced the production of insulin and pancreatic endocrine genes and these responded to glucose stimulation in vitro. rGBCs also expressed an islet-specific surface marker, which was used to enrich for the most highly reprogrammed cells. More importantly, global mRNA and microRNA expression profiles and protein immunostaining indicated that rGBCs adopted an overall β-like state and these rGBCs engrafted in immunodeficient mice. Furthermore, comparative global expression analyses identified putative regulators of human biliary to β cell fate conversion. In summary, we have developed, for the first time, a reliable and robust genetic reprogramming and culture expansion of primary human GBCs—derived from multiple unrelated donors—into pancreatic β-like cells ex vivo, thus showing that human gallbladder is a potentially rich source of reprogrammable cells for autologous cell therapy in diabetes. PMID:28813430

Preconditioning With Low-Level Laser Irradiation Enhances the Therapeutic Potential of Human Adipose-derived Stem Cells in a Mouse Model of Photoaged Skin.

PubMed

Liao, Xuan; Li, Sheng-Hong; Xie, Guang-Hui; Xie, Shan; Xiao, Li-Ling; Song, Jian-Xing; Liu, Hong-Wei

2018-02-19

This study was conducted to explore the therapeutic potential of human adipose-derived stem cells (ADSCs) irradiated with a low-level laser (LLL). Cultured ADSCs were treated with 650-nm GaAlAs laser irradiation at 2, 4 and 8 J cm -2 . Cell proliferation was quantified by MTT assays, cytokine secretion was determined by enzyme-linked immunosorbent assays, and adipogenic differentiation was examined by oil red O staining. Additionally, the expression profiles of putative ADSC surface markers were analyzed by quantitative real-time PCR. In addition, a mouse photoaged skin model was established by UVB irradiation. Effects of GaAlAs laser-treated ADSCs on the thicknesses of the epidermis and dermis were analyzed by hematoxylin and eosin staining. The results showed that GaAlAs laser treatment of cells at a radiant exposure of 4 J cm -2 enhanced ADSC proliferation and adipogenic differentiation and increased secretion of growth factors. Furthermore, GaAlAs laser irradiation upregulated the expression of putative ADSC surface markers. In the mouse model of photoaged skin, ADSCs treated with GaAlAs laser irradiation had markedly decreased the epidermal thickness and increased the dermal thickness of photoaged mouse skin. Our data indicate that LLL irradiation is an effective biostimulator of ADSCs and might enhance the therapeutic potential of ADSCs for clinical use. © 2018 The American Society of Photobiology.

Regenerative therapy for vestibular disorders using human induced pluripotent stem cells (iPSCs): neural differentiation of human iPSC-derived neural stem cells after in vitro transplantation into mouse vestibular epithelia.

PubMed

Taura, Akiko; Nakashima, Noriyuki; Ohnishi, Hiroe; Nakagawa, Takayuki; Funabiki, Kazuo; Ito, Juichi; Omori, Koichi

2016-10-01

Vestibular ganglion cells, which convey sense of motion from vestibular hair cells to the brainstem, are known to degenerate with aging and after vestibular neuritis. Thus, regeneration of vestibular ganglion cells is important to aid in the recovery of balance for associated disorders. The present study derived hNSCs from induced pluripotent stem cells (iPSCs) and transplanted these cells into mouse utricle tissues. After a 7-day co-culture period, histological and electrophysiological examinations of transplanted hNSCs were performed. Injected hNSC-derived cells produced elongated axon-like structures within the utricle tissue that made contact with vestibular hair cells. A proportion of hNSC-derived cells showed spontaneous firing activities, similar to those observed in cultured mouse vestibular ganglion cells. However, hNSC-derived cells around the mouse utricle persisted as immature neurons or occasionally differentiated into putative astrocytes. Moreover, electrophysiological examination showed hNSC-derived cells around utricles did not exhibit any obvious spontaneous firing activities. Injected human neural stem cells (hNSCs) showed signs of morphological maturation including reconnection to denervated hair cells and partial physiological maturation, suggesting hNSC-derived cells possibly differentiated into neurons.

Identification and Single-Cell Functional Characterization of an Endodermally Biased Pluripotent Substate in Human Embryonic Stem Cells.

PubMed

Allison, Thomas F; Smith, Andrew J H; Anastassiadis, Konstantinos; Sloane-Stanley, Jackie; Biga, Veronica; Stavish, Dylan; Hackland, James; Sabri, Shan; Langerman, Justin; Jones, Mark; Plath, Kathrin; Coca, Daniel; Barbaric, Ivana; Gokhale, Paul; Andrews, Peter W

2018-05-09

Human embryonic stem cells (hESCs) display substantial heterogeneity in gene expression, implying the existence of discrete substates within the stem cell compartment. To determine whether these substates impact fate decisions of hESCs we used a GFP reporter line to investigate the properties of fractions of putative undifferentiated cells defined by their differential expression of the endoderm transcription factor, GATA6, together with the hESC surface marker, SSEA3. By single-cell cloning, we confirmed that substates characterized by expression of GATA6 and SSEA3 include pluripotent stem cells capable of long-term self-renewal. When clonal stem cell colonies were formed from GATA6-positive and GATA6-negative cells, more of those derived from GATA6-positive cells contained spontaneously differentiated endoderm cells than similar colonies derived from the GATA6-negative cells. We characterized these discrete cellular states using single-cell transcriptomic analysis, identifying a potential role for SOX17 in the establishment of the endoderm-biased stem cell state. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

MiR-34a regulates the invasive capacity of canine osteosarcoma cell lines

PubMed Central

Lopez, Cecilia M.; Yu, Peter Y.; Zhang, Xiaoli; Yilmaz, Ayse Selen; London, Cheryl A.

2018-01-01

Background Osteosarcoma (OSA) is the most common bone tumor in children and dogs; however, no substantial improvement in clinical outcome has occurred in either species over the past 30 years. MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression and play a fundamental role in cancer. The purpose of this study was to investigate the potential contribution of miR-34a loss to the biology of canine OSA, a well-established spontaneous model of the human disease. Methodology and principal findings RT-qPCR demonstrated that miR-34a expression levels were significantly reduced in primary canine OSA tumors and canine OSA cell lines as compared to normal canine osteoblasts. In canine OSA cell lines stably transduced with empty vector or pre-miR-34a lentiviral constructs, overexpression of miR-34a inhibited cellular invasion and migration but had no effect on cell proliferation or cell cycle distribution. Transcriptional profiling of canine OSA8 cells possessing enforced miR-34a expression demonstrated dysregulation of numerous genes, including significant down-regulation of multiple putative targets of miR-34a. Moreover, gene ontology analysis of down-regulated miR-34a target genes showed enrichment of several biological processes related to cell invasion and motility. Lastly, we validated changes in miR-34a putative target gene expression, including decreased expression of KLF4, SEM3A, and VEGFA transcripts in canine OSA cells overexpressing miR-34a and identified KLF4 and VEGFA as direct target genes of miR-34a. Concordant with these data, primary canine OSA tumor tissues demonstrated increased expression levels of putative miR-34a target genes. Conclusions These data demonstrate that miR-34a contributes to invasion and migration in canine OSA cells and suggest that loss of miR-34a may promote a pattern of gene expression contributing to the metastatic phenotype in canine OSA. PMID:29293555

MiR-34a regulates the invasive capacity of canine osteosarcoma cell lines.

PubMed

Lopez, Cecilia M; Yu, Peter Y; Zhang, Xiaoli; Yilmaz, Ayse Selen; London, Cheryl A; Fenger, Joelle M

2018-01-01

Osteosarcoma (OSA) is the most common bone tumor in children and dogs; however, no substantial improvement in clinical outcome has occurred in either species over the past 30 years. MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression and play a fundamental role in cancer. The purpose of this study was to investigate the potential contribution of miR-34a loss to the biology of canine OSA, a well-established spontaneous model of the human disease. RT-qPCR demonstrated that miR-34a expression levels were significantly reduced in primary canine OSA tumors and canine OSA cell lines as compared to normal canine osteoblasts. In canine OSA cell lines stably transduced with empty vector or pre-miR-34a lentiviral constructs, overexpression of miR-34a inhibited cellular invasion and migration but had no effect on cell proliferation or cell cycle distribution. Transcriptional profiling of canine OSA8 cells possessing enforced miR-34a expression demonstrated dysregulation of numerous genes, including significant down-regulation of multiple putative targets of miR-34a. Moreover, gene ontology analysis of down-regulated miR-34a target genes showed enrichment of several biological processes related to cell invasion and motility. Lastly, we validated changes in miR-34a putative target gene expression, including decreased expression of KLF4, SEM3A, and VEGFA transcripts in canine OSA cells overexpressing miR-34a and identified KLF4 and VEGFA as direct target genes of miR-34a. Concordant with these data, primary canine OSA tumor tissues demonstrated increased expression levels of putative miR-34a target genes. These data demonstrate that miR-34a contributes to invasion and migration in canine OSA cells and suggest that loss of miR-34a may promote a pattern of gene expression contributing to the metastatic phenotype in canine OSA.

Profiling Antibody Responses to Infections by Chlamydia abortus Enables Identification of Potential Virulence Factors and Candidates for Serodiagnosis

PubMed Central

Forsbach-Birk, Vera; Foddis, Corinna; Simnacher, Ulrike; Wilkat, Max; Longbottom, David; Walder, Gernot; Benesch, Christiane; Ganter, Martin; Sachse, Konrad; Essig, Andreas

2013-01-01

Enzootic abortion of ewes (EAE) due to infection with the obligate intracellular pathogen Chlamydia (C.) abortus is an important zoonosis leading to considerable economic loss to agriculture worldwide. The pathogen can be transmitted to humans and may lead to serious infection in pregnant women. Knowledge about epidemiology, clinical course and transmission to humans is hampered by the lack of reliable diagnostic tools. Immunoreactive proteins, which are expressed in infected animals and humans, may serve as novel candidates for diagnostic marker proteins and represent putative virulence factors. In order to broaden the spectrum of immunogenic C. abortus proteins we applied 2D immunoblot analysis and screening of an expression library using human and animal sera. We have identified 48 immunoreactive proteins representing potential diagnostic markers and also putative virulence factors, such as CAB080 (homologue of the “macrophage infectivity potentiator”, MIP), CAB167 (homologue of the “translocated actin recruitment protein”, TARP), CAB712 (homologue of the “chlamydial protease-like activity factor”, CPAF), CAB776 (homologue of the “Polymorphic membrane protein D”, PmpD), and the “hypothetical proteins” CAB063, CAB408 and CAB821, which are predicted to be type III secreted. We selected two putative virulence factors for further characterization, i.e. CAB080 (cMIP) and CAB063, and studied their expression profiles at transcript and protein levels. Analysis of the subcellular localization of both proteins throughout the developmental cycle revealed CAB063 being the first C. abortus protein shown to be translocated to the host cell nucleus. PMID:24260366

Chimeras taking shape: Potential functions of proteins encoded by chimeric RNA transcripts

PubMed Central

Frenkel-Morgenstern, Milana; Lacroix, Vincent; Ezkurdia, Iakes; Levin, Yishai; Gabashvili, Alexandra; Prilusky, Jaime; del Pozo, Angela; Tress, Michael; Johnson, Rory; Guigo, Roderic; Valencia, Alfonso

2012-01-01

Chimeric RNAs comprise exons from two or more different genes and have the potential to encode novel proteins that alter cellular phenotypes. To date, numerous putative chimeric transcripts have been identified among the ESTs isolated from several organisms and using high throughput RNA sequencing. The few corresponding protein products that have been characterized mostly result from chromosomal translocations and are associated with cancer. Here, we systematically establish that some of the putative chimeric transcripts are genuinely expressed in human cells. Using high throughput RNA sequencing, mass spectrometry experimental data, and functional annotation, we studied 7424 putative human chimeric RNAs. We confirmed the expression of 175 chimeric RNAs in 16 human tissues, with an abundance varying from 0.06 to 17 RPKM (Reads Per Kilobase per Million mapped reads). We show that these chimeric RNAs are significantly more tissue-specific than non-chimeric transcripts. Moreover, we present evidence that chimeras tend to incorporate highly expressed genes. Despite the low expression level of most chimeric RNAs, we show that 12 novel chimeras are translated into proteins detectable in multiple shotgun mass spectrometry experiments. Furthermore, we confirm the expression of three novel chimeric proteins using targeted mass spectrometry. Finally, based on our functional annotation of exon organization and preserved domains, we discuss the potential features of chimeric proteins with illustrative examples and suggest that chimeras significantly exploit signal peptides and transmembrane domains, which can alter the cellular localization of cognate proteins. Taken together, these findings establish that some chimeric RNAs are translated into potentially functional proteins in humans. PMID:22588898

CDB-4124 and its putative monodemethylated metabolite, CDB-4453, are potent antiprogestins with reduced antiglucocorticoid activity: in vitro comparison to mifepristone and CDB-2914.

PubMed

Attardi, Barbara J; Burgenson, Janet; Hild, Sheri A; Reel, Jerry R; Blye, Richard P

2002-02-25

To obtain selective antiprogestins, we have examined the in vitro antiprogestational/antiglucocorticoid properties of two novel compounds, CDB-4124 and the putative monodemethylated metabolite, CDB-4453, in transcription and receptor binding assays and compared them to CDB-2914 and mifepristone. All four antiprogestins bound with high affinity to rabbit uterine progestin receptors (PR) and recombinant human PR-A and PR-B (rhPR-A, rhPR-B) and were potent inhibitors of R5020-induced transactivation of the PRE2-tk-luciferase (PRE2-tk-LUC) reporter plasmid and endogenous alkaline phosphatase production in T47D-CO human breast cancer cells. None of these compounds exhibited agonist activity in these cells. Induction of luciferase activity was potentiated about five-fold by 8-Br-cAMP under basal conditions and to the same extent in the presence of the PR antagonists. Mifepristone bound to rabbit thymic glucocorticoid receptors (GR) with approximately twice the avidity of the CDB antiprogestins. Inhibition of GR-mediated transcription of PRE2-tk-LUC was assessed in HepG2 human hepatoblastoma cells. Mifepristone exhibited greater antiglucocorticoid activity than CDB-2914, 4124, and 4453, about 12-, 22-, and 185-fold, respectively. Thus, while there was a good correlation between binding to PR and functional activity of these antiprogestins, GR binding was not predictive of their glucocorticoid antagonist activity. In agreement with our in vivo results, CDB-4124 and CDB-4453, as well as CDB-2914, are potent antiprogestins in vitro, but show considerably less antiglucocorticoid activity than mifepristone.

Evaluation of the Selenotranscriptome Expression in Two Hepatocellular Carcinoma Cell Lines

PubMed Central

Guariniello, Stefano; Di Bernardo, Giovanni; Cammarota, Marcella; Castello, Giuseppe

2015-01-01

Hepatocellular carcinoma (HCC) is the most common type of liver cancer and is still one of the most fatal cancers. Hence, it needs to identify always new putative markers to improve its diagnosis and prognosis. Since the selenium is able to fight the oxidative damage which is one of the major origins of cell damage as well as cancer, we have recently focused our attention on selenoprotein family and their involvement in HCC. In the present paper we have carried out a global analysis of the selenotranscriptome expression in HepG2 and Huh7 cells compared to the normal human hepatocytes by reverse transcription-qPCR (RT-qPCR). Our data showed that in both cells there are three downregulated (DIO1, DIO2, and SELO) and ten upregulated (GPX4, GPX7, SELK, SELM, SELN, SELT, SELV, SEP15, SEPW1, and TrxR1) genes. Additionally, interactomic studies were carried out to evaluate the ability of these down- and upregulated genes to interact between them as well as to identify putative HUB nodes representing the centers of correlation able to exercise a direct control over the coordinated genes. PMID:26199857

Mutation of a putative MAP kinase consensus site regulates NCAM endocytosis and NCAM-dependent neurite outgrowth.

PubMed

Goschzik, Tobias; Cremer, Harold; Gnanapragassam, Vinayaga S; Horstkorte, Rüdiger; Bork, Kaya; Diestel, Simone

2017-07-01

The cytoplasmic domain of the neural cell adhesion molecule NCAM contains several putative serine/threonine phosphorylation sites whose functions are largely unknown. Human NCAM140 (NCAM140) possesses a potential MAP kinase phosphorylation site at threonine (T) 803. The aim of this study was to analyze a possible phosphorylation of NCAM140 by MAP kinases and to identify the functional role of T803. We found that NCAM140 is phosphorylated by the MAP kinase ERK2 in vitro. Exchange of T803 to aspartic acid (D) which mimics constitutive phosphorylation at the respective position resulted in increased endocytosis compared to NCAM140 in neuroblastoma cells and primary neurons. Consistently, NCAM140 endocytosis was inhibited by the MEK inhibitor U0126 in contrast to NCAM140-T803D or NCAM140-T803A endocytosis supporting a role of a potential ERK2 mediated phosphorylation at this site in endocytosis. Furthermore, cells expressing NCAM140-T803D developed significantly shorter neurites than NCAM140 expressing cells indicating that a potential phosphorylation of NCAM by ERK2 also regulates NCAM-dependent neurite outgrowth. Copyright © 2017 Elsevier Ireland Ltd and Japan Neuroscience Society. All rights reserved.

Oligosaccharide receptor mimics inhibit Legionella pneumophila attachment to human respiratory epithelial cells.

PubMed

Thomas, Richard J; Brooks, Tim J

2004-02-01

Legionnaire's disease is caused by the intracellular pathogen Legionella pneumophila, presenting as an acute pneumonia. Attachment is the key step during infection, often relying on an interaction between host cell oligosaccharides and bacterial adhesins. Inhibition of this interaction by receptor mimics offers possible novel therapeutic treatments. L. pneumophila attachment to the A549 cell line was significantly reduced by treatment with tunicamycin (73.6%) and sodium metaperiodate (63.7%). This indicates the importance of cell surface oligosaccharide chains in adhesion. A number of putative anti-adhesion compounds inhibited attachment to the A549 and U937 cell lines. The most inhibitory compounds were polymeric saccharides, GalNAcbeta1-4Gal, Galbeta1-4GlcNAc and para-nitrophenol. These compounds inhibited adhesion to a range of human respiratory cell lines, including nasal epithelial, bronchial epithelial and alveolar epithelial cell lines and the human monocytic cell line, U937. Some eukaryotic receptors for L. pneumophila were determined to be the glycolipids, asialo-GM1 and asialo-GM2 that contain the inhibitory saccharide moiety, GalNAcbeta1-4Gal. The identified compounds have the potential to be used as novel treatments for Legionnaire's disease.

SLC6A19 is a novel putative gene, induced by dioxins via AhR in human hepatoma HepG2 cells.

PubMed

Tian, Wenjing; Fu, Hualing; Xu, Tuan; Xu, Sherry Li; Guo, Zhiling; Tian, Jijing; Tao, Wuqun; Xie, Heidi Qunhui; Zhao, Bin

2018-06-01

The aryl hydrocarbon receptor (AhR) plays an important role in mediating dioxins toxicity. Currently, genes of P450 families are major research interests in studies on AhR-mediated gene alterations caused by dioxins. Genes related to other metabolic pathways or processes may be also responsive to dioxin exposures. Amino acid transporter B0AT1 (encoded by SLC6A19) plays a decisive role in neutral amino acid transport which is present in kidney, intestine and liver. However, effects of dioxins on its expression are still unknown. In the present study, we focused on the effects of dioxin and dioxin-like compounds on SLC6A19 expression in HepG2 cells. We identified SLC6A19 as a novel putative target gene of AhR activation in HepG2 cells. 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD) increased the expression of SLC6A19 in time- and concentration-dependent manners. Using AhR antagonist CH223191 and/or siRNA assays, we demonstrated that certain AhR agonists upregulated SLC6A19 expression via AhR, including TCDD, 1,2,3,7,8-pentachlorodibenzo-p-dioxin (1,2,3,7,8-PeCDD), 2,3,4,7,8- pentachlorodibenzofuran (2,3,4,7,8-PeCDF) and PCB126. In addition, the expression of B0AT1 was also significantly induced by TCDD in HepG2 cells. Our study suggested that dioxins might affect the transcription and translation of SLC6A19 in HepG2 cells, which might be a novel putative gene to assess dioxins' toxicity in amino acid transport and metabolism in liver. Copyright © 2018 Elsevier Ltd. All rights reserved.

The SRE Motif in the Human PNPLA3 Promoter (-97 to -88 bp) Mediates Transactivational Effects of SREBP-1c.

PubMed

Liang, Hua; Xu, Jing; Xu, Fen; Liu, Hongxia; Yuan, Ding; Yuan, Shuhua; Cai, Mengyin; Yan, Jinhua; Weng, Jianping

2015-09-01

Patatin-like phospholipase domain containing 3 (PNPLA3) is a non-secreted protein primarily expressed in liver and adipose tissue. Recently, numerous genetic studies have shown that PNPLA3 is a major susceptibility gene for nonalcoholic fatty liver disease (NAFLD). However, the mechanism involved in transcriptional regulation of the PNPLA3 gene remains unknown. We performed a detailed analysis of the human PNPLA3 gene promoter and identified two novel cis-acting elements (SRE and NFY binding motifs) located at -97/-88 and -26/-22 bp, respectively. Overexpression of SREBP-1c in HepG2 cells significantly increased PNPLA3 promoter activity. Mutation of either of the putative SRE or NFY binding motifs blocked the transactivation effects of SREBP-1c on the promoter. Overexpression of SREBP-1c and NFY together increased PNPLA3 promoter activity twice as much as that of SREBP-1c or NFY expression alone. This result suggests that SREBP-1c and NFY synergistically transactivate the human PNPLA3 gene. The ability of SREBP-1c and NFY to bind these cis-elements was confirmed using gel shift analysis. Putative SRE and NFY motifs also mediated synergistic insulin-induced transactivation of the PNPLA3 promoter in HepG2 cells. Additionally, the ability of SREBP-1c to bind to the PNPLA3 promoter was increased by insulin in a dose-dependent manner. Moreover, the treatment of HepG2 cells with the PI3K inhibitor LY294002 led to reduced insulin promoter-activating ability accompanied by a decrease in PNPLA3 and SREBP-1c protein expression. These results demonstrate that SREBP-1c is a direct activator of the human PNPLA3 gene and insulin transactivates the PNPLA3 gene via the PI3K-SREBP-1c/NFY pathway in HepG2 cells. © 2015 Wiley Periodicals, Inc.

Interleukin 4-producing CD4+ T cells in the skin of cats with allergic dermatitis.

PubMed

Roosje, P J; Dean, G A; Willemse, T; Rutten, V P M G; Thepen, T

2002-03-01

Lesional skin of cats with allergic dermatitis has a cellular infiltrate and a CD4/CD8 ratio comparable to that in humans with atopic dermatitis. CD4+ helper T cells and in particular cells belonging to the Th2 subset play an important role in disease pathogenesis in humans. We investigated the cytokine pattern of CD4+ T cells in situ, with special emphasis on the putative presence of cells producing interleukin 4 (IL4), in cats with allergic dermatitis. Immunohistochemical procedures were used to determine that CD4+ T cells in lesional and nonlesional skin of cats with allergic dermatitis can produce IL4, as occurs in humans. Lesional and nonlesional skin of cats with allergic dermatitis had significantly more IL4+ T cells (P = 0.001) than did skin of healthy control cats. Double staining indicated that all IL4+ cells were positive for pan-T or CD4 markers. Double labeling for mast cell chymase and IL4 stained primarily different cells. Western blotting demonstrated cross-reactivity between the antibody against human IL4 and a feline recombinant IL4. These results indicate that IL4 is primarily produced by CD4+ T cells and is also present in clinically uninvolved skin, indicating a role in the pathogenesis of allergic dermatitis in cats.

Isolation, molecular cloning and in vitro expression of rhesus monkey (Macaca mulatta) prominin-1.s1 complementary DNA encoding a potential hematopoietic stem cell antigen.

PubMed

Husain, S M; Shou, Y; Sorrentino, B P; Handgretinger, R

2006-10-01

Human prominin-1 (CD133 or AC133) is an important cell surface marker used to isolate primitive hematopoietic stem cells. The commercially available antibody to human prominin-1 does not recognize rhesus prominin-1. Therefore, we isolated, cloned and characterized the complementary DNA (cDNA) of rhesus prominin-1 gene and determined its coding potential. Following the nomenclature of prominin family of genes, we named this cDNA as rhesus prominin-1.s1. The amino acid sequence data of the putative rhesus prominin-1.s1 could be used in designing antigenic peptides to raise antibodies for use in isolation of pure populations of rhesus prominin-1(+) hematopoietic cells. To the best of our knowledge, there has been no previously published report about the isolation of a prominin-1 cDNA from rhesus monkey (Macaca mulatta).

Identification of Putative Metastasis Suppressor MicroRNA in Human Breast Cancer

DTIC Science & Technology

2009-11-01

receptor a-positive human breast cancer. Cancer Res. 68, 5004–5008. Krek, A., Grün, D., Poy, M.N., Wolf , R., Rosenberg, L., Epstein, E.J., MacMe- namin...Nadal C, Shu W, Gomis RR, Nguyen DX, et al. Genes that mediate breast cancer metastasis to the brain. Nature 2009; 459:1005-9. 49. Friedl P, Wolf K...Simultaneous reintroduction of ITGA5 and RhoA in miR-31-expressing cells sufficed to completely override miR-31-imposed obstruction of early post

Identification of Multipotent Stem Cells in Human Brain Tissue Following Stroke.

PubMed

Tatebayashi, Kotaro; Tanaka, Yasue; Nakano-Doi, Akiko; Sakuma, Rika; Kamachi, Saeko; Shirakawa, Manabu; Uchida, Kazutaka; Kageyama, Hiroto; Takagi, Toshinori; Yoshimura, Shinichi; Matsuyama, Tomohiro; Nakagomi, Takayuki

2017-06-01

Perivascular regions of the brain harbor multipotent stem cells. We previously demonstrated that brain pericytes near blood vessels also develop multipotency following experimental ischemia in mice and these ischemia-induced multipotent stem cells (iSCs) can contribute to neurogenesis. However, it is essential to understand the traits of iSCs in the poststroke human brain for possible applications in stem cell-based therapies for stroke patients. In this study, we report for the first time that iSCs can be isolated from the poststroke human brain. Putative iSCs were derived from poststroke brain tissue obtained from elderly stroke patients requiring decompressive craniectomy and partial lobectomy for diffuse cerebral infarction. Immunohistochemistry showed that these iSCs were localized near blood vessels within poststroke areas containing apoptotic/necrotic neurons and expressed both the stem cell marker nestin and several pericytic markers. Isolated iSCs expressed these same markers and demonstrated high proliferative potential without loss of stemness. Furthermore, isolated iSCs expressed other stem cell markers, such as Sox2, c-myc, and Klf4, and differentiated into multiple cells in vitro, including neurons. These results show that iSCs, which are likely brain pericyte derivatives, are present within the poststroke human brain. This study suggests that iSCs can contribute to neural repair in patients with stroke.

Intra-femoral injection of human mesenchymal stem cells.

PubMed

Mohanty, Sindhu T; Bellantuono, Ilaria

2013-01-01

In vivo transplantation of putative populations of hematopoietic stem cells (HSC) and assessment of their engraftment is considered the golden standard to assess their quality and degree of stemness. Transplantation is usually carried out by intravenous injection in murine models and assessment of engraftment is performed by monitoring the number and type of mature blood cells produced by the donor cells in time. In contrast intravenous injection of mesenchymal stem cells (MSC), the multipotent stem cells present in bone marrow and capable of differentiating to osteoblasts, chondrocytes and adipocytes, has not been successful. This is due to limited or absent engraftment levels. Here, we describe the use of intra-femoral injection as an improved method to assess MSC engraftment to bone and bone marrow and their quality.

HTLV-I Tax-dependent and -independent events associated with immortalization of human primary T lymphocytes

PubMed Central

Bellon, Marcia; Baydoun, Hicham H.; Yao, Yuan

2010-01-01

Human T-cell leukemia virus type I (HTLV-I)–associated malignancies are seen in a small percentage of infected persons. Although in vitro immortalization by HTLV-I virus is very efficient, we report that Tax has poor oncogenic activity in human primary T cells and that immortalization by Tax is rare. Sustained telomerase activity represents one of the oncogenic steps required for Tax-mediated immortalization. Tax expression was required for the growth of primary T cells, but was not sufficient to propel T cells into cell cycle in the absence of exogenous interleukin-2 (IL-2). Tax was sufficient to activate the phosphoinositide-3 kinase (PI3K)/Akt pathway as shown by down regulation of Src homology phosphatase-1 and increased phosphorylation of Akt. We also found disruption of putative tumor suppressors IL-16 and translocated promoter region (TPR) in Tax-immortalized and HTLV-I–transformed cell lines. Our results confirmed previous observations that Tax activates the anaphase-promoting complex. However, Tax did not affect the mitotic spindle checkpoint, which was also functional in HTLV-I–transformed cells. These data provide a better understanding of Tax functions in human T cells, and highlight the limitations of Tax, suggesting that other viral proteins are key to T-cell transformation and development of adult T-cell leukemia. PMID:20093405

Putative bronchopulmonary flagellated protozoa in immunosuppressed patients.

PubMed

Kilimcioglu, Ali Ahmet; Havlucu, Yavuz; Girginkardesler, Nogay; Celik, Pınar; Yereli, Kor; Özbilgin, Ahmet

2014-01-01

Flagellated protozoa that cause bronchopulmonary symptoms in humans are commonly neglected. These protozoal forms which were presumed to be "flagellated protozoa" have been previously identified in immunosuppressed patients in a number of studies, but have not been certainly classified so far. Since no human cases of bronchopulmonary flagellated protozoa were reported from Turkey, we aimed to investigate these putative protozoa in immunosuppressed patients who are particularly at risk of infectious diseases. Bronchoalveolar lavage fluid samples of 110 immunosuppressed adult patients who were admitted to the Department of Chest Diseases, Hafsa Sultan Hospital of Celal Bayar University, Manisa, Turkey, were examined in terms of parasites by light microscopy. Flagellated protozoal forms were detected in nine (8.2%) of 110 cases. Metronidazole (500 mg b.i.d. for 30 days) was given to all positive cases and a second bronchoscopy was performed at the end of the treatment, which revealed no parasites. In conclusion, immunosuppressed patients with bronchopulmonary symptoms should attentively be examined with regard to flagellated protozoa which can easily be misidentified as epithelial cells.

Bulge Region as a Putative Hair Follicle Stem Cells Niche: A Brief Review

PubMed Central

JOULAI VEIJOUYE, Sanaz; YARI, Abazar; HEIDARI, Fatemeh; SAJEDI, Nayereh; GHOROGHI MOGHANI, Fatemeh; NOBAKHT, Maliheh

2017-01-01

Background: Hair follicle stem cells exist in different sites. Most of the hair follicle stem cells are reside in niche called bulge. Bulge region is located between the opening of sebaceous gland and the attachment site of the arrector pili muscle. Methods: Data were collected using databases and resources of PubMed, Web of Science, Science Direct, Scopus, MEDLINE and their references from the earliest available published to identify English observational studies on hair follicle bulge region. Results: Bulge stem cells are pluripotent with high proliferative capacity. Specific markers allow the bulge cells to be isolated from mouse or human hair follicle. Stem cells isolated from bulge region are label retaining and slow cycling hence these cells are defined as label-retaining cells. Bulge cell populations, due to their plasticity nature are able to differentiate into distinct linage and could contribute in tissue regeneration. Conclusion: The current review discuss about bulge stem cells characteristics and biology including their cycle, location, plasticity, specific markers and regenerative nature. Also the differences between mouse and human hair follicles are investigated. PMID:29026781

MicroRNA regulatory networks reflective of polyhexamethylene guanidine phosphate-induced fibrosis in A549 human alveolar adenocarcinoma cells.

PubMed

Shin, Da Young; Jeong, Mi Ho; Bang, In Jae; Kim, Ha Ryong; Chung, Kyu Hyuck

2018-05-01

Polyhexamethylene guanidine phosphate (PHMG-phosphate), an active component of humidifier disinfectant, is suspected to be a major cause of pulmonary fibrosis. Fibrosis, induced by recurrent epithelial damage, is significantly affected by epigenetic regulation, including microRNAs (miRNAs). The aim of this study was to investigate the fibrogenic mechanisms of PHMG-phosphate through the profiling of miRNAs and their target genes. A549 cells were treated with 0.75 μg/mL PHMG-phosphate for 24 and 48 h and miRNA microarray expression analysis was conducted. The putative mRNA targets of the miRNAs were identified and subjected to Gene Ontology analysis. After exposure to PHMG-phosphate for 24 and 48 h, 46 and 33 miRNAs, respectively, showed a significant change in expression over 1.5-fold compared with the control. The integrated analysis of miRNA and mRNA microarray results revealed the putative targets that were prominently enriched were associated with the epithelial-mesenchymal transition (EMT), cell cycle changes, and apoptosis. The dose-dependent induction of EMT by PHMG-phosphate exposure was confirmed by western blot. We identified 13 putative EMT-related targets that may play a role in PHMG-phosphate-induced fibrosis according to the Comparative Toxicogenomic Database. Our findings contribute to the comprehension of the fibrogenic mechanism of PHMG-phosphate and will aid further study on PHMG-phosphate-induced toxicity. Copyright © 2018 Elsevier B.V. All rights reserved.

Invasion of Human Coronary Artery Cells by Periodontal Pathogens

PubMed Central

Dorn, Brian R.; Dunn, William A.; Progulske-Fox, Ann

1999-01-01

There is an emerging paradigm shift from coronary heart disease having a purely hereditary and nutritional causation to possibly having an infectious etiology. Recent epidemiological studies have shown a correlation between periodontal disease and coronary heart disease. However, to date, there is minimal information as to the possible disease mechanisms of this association. It is our hypothesis that invasion of the coronary artery cells by oral bacteria may start and/or exacerbate the inflammatory response in atherosclerosis. Since a few periodontal pathogens have been reported to invade oral epithelial tissues, we tested the ability of three putative periodontal pathogens—Eikenella corrodens, Porphyromonas gingivalis, and Prevotella intermedia—to invade human coronary artery endothelial cells and coronary artery smooth muscle cells. In this study we demonstrate by an antibiotic protection assay and electron microscopy that specific species and strains invade coronary artery cells at a significant level. Actin polymerization and eukaryotic protein synthesis in metabolically active cells were required since the corresponding inhibitors nearly abrogated invasion. Many intracellular P. gingivalis organisms were seen to be present in multimembranous vacuoles resembling autophagosomes by morphological analysis. This is the first report of oral microorganisms invading human primary cell cultures of the vasculature. PMID:10531230

Single-cell lineage tracking analysis reveals that an established cell line comprises putative cancer stem cells and their heterogeneous progeny

PubMed Central

Sato, Sachiko; Rancourt, Ann; Sato, Yukiko; Satoh, Masahiko S.

2016-01-01

Mammalian cell culture has been used in many biological studies on the assumption that a cell line comprises putatively homogeneous clonal cells, thereby sharing similar phenotypic features. This fundamental assumption has not yet been fully tested; therefore, we developed a method for the chronological analysis of individual HeLa cells. The analysis was performed by live cell imaging, tracking of every single cell recorded on imaging videos, and determining the fates of individual cells. We found that cell fate varied significantly, indicating that, in contrast to the assumption, the HeLa cell line is composed of highly heterogeneous cells. Furthermore, our results reveal that only a limited number of cells are immortal and renew themselves, giving rise to the remaining cells. These cells have reduced reproductive ability, creating a functionally heterogeneous cell population. Hence, the HeLa cell line is maintained by the limited number of immortal cells, which could be putative cancer stem cells. PMID:27003384

Zika virus crosses an in vitro human blood brain barrier model.

PubMed

Alimonti, Judie B; Ribecco-Lutkiewicz, Maria; Sodja, Caroline; Jezierski, Anna; Stanimirovic, Danica B; Liu, Qing; Haqqani, Arsalan S; Conlan, Wayne; Bani-Yaghoub, Mahmud

2018-05-15

Zika virus (ZIKV) is a flavivirus that is highly neurotropic causing congenital abnormalities and neurological damage to the central nervous systems (CNS). In this study, we used a human induced pluripotent stem cell (iPSC)-derived blood brain barrier (BBB) model to demonstrate that ZIKV can infect brain endothelial cells (i-BECs) without compromising the BBB barrier integrity or permeability. Although no disruption to the BBB was observed post-infection, ZIKV particles were released on the abluminal side of the BBB model and infected underlying iPSC-derived neural progenitor cells (i-NPs). AXL, a putative ZIKV cellular entry receptor, was also highly expressed in ZIKV-susceptible i-BEC and i-NPs. This iPSC-derived BBB model can help elucidate the mechanism by which ZIKV can infect BECs, cross the BBB and gain access to the CNS.

Cloning, expression and characterization of a novel human CAP10-like gene hCLP46 from CD34(+) stem/progenitor cells.

PubMed

Teng, Yun; Liu, Qiaohong; Ma, Jie; Liu, Feng; Han, Zeguang; Wang, Youxin; Wang, Wei

2006-04-12

A novel human gene, named as human CAP10-like protein 46 kDa (hCLP46), was isolated and identified from human acute myeloid leukemia transformed from myelodysplastic syndrome (MDS-AML) CD34(+) cells. hCLP46 (3q13.33) contains 11 exons encoding a putative protein of 392 amino acids, with a highly conserved CAP10 domain, a hydrophobic signal peptide at its N-terminus, and an endoplasmic reticulum (ER) retention signal motif KTEL at the C-terminus. The homologs of hCLP46 exist in different organisms from plants to animal kingdoms. Subcellular localization analysis showed that hCLP46 is an ER-resident protein. hCLP46 expressed in most human adult tissues at different intensities, with lengths of 3.5 kb and 1.9 kb. Transcript of hCLP46 was not detectable in colon, thymus, and small intestine, but was abundant in liver, indicating that hCLP46 may be involved in important physiological functions in the liver. hCLP46 over-expressed U937 cells had higher growth rate than the cells without exogenic hCLP46 protein expression, suggesting that hCLP46 protein possess the ability of promoting cell proliferation.

Enrichment of putative stem cells from adipose tissue using dielectrophoretic field-flow fractionation

PubMed Central

Vykoukal, Jody; Vykoukal, Daynene M.; Freyberg, Susanne; Alt, Eckhard U.; Gascoyne, Peter R. C.

2009-01-01

We have applied the microfluidic cell separation method of dielectrophoretic field-flow fractionation (DEP-FFF) to the enrichment of a putative stem cell population from an enzyme-digested adipose tissue derived cell suspension. A DEP-FFF separator device was constructed using a novel microfluidic-microelectronic hybrid flex-circuit fabrication approach that is scaleable and anticipates future low-cost volume manufacturing. We report the separation of a nucleated cell fraction from cell debris and the bulk of the erythrocyte population, with the relatively rare (<2% starting concentration) NG2-positive cell population (pericytes and/or putative progenitor cells) being enriched up to 14-fold. This work demonstrates a potential clinical application for DEP-FFF and further establishes the utility of the method for achieving label-free fractionation of cell subpopulations. PMID:18651083

Distribution and innervation of putative peripheral arterial chemoreceptors in the red-eared slider (Trachemys scripta elegans).

PubMed

Reyes, Catalina; Fong, Angelina Y; Milsom, William K

2015-06-15

Peripheral arterial chemoreceptors have been isolated to the common carotid artery, aorta, and pulmonary artery of turtles. However, the putative neurotransmitters associated with these chemoreceptors have not yet been described. The goal of the present study was to determine the neurochemical content, innervations, and distribution of putative oxygen-sensing cells in the central vasculature of turtles and to derive homologies with peripheral arterial chemoreceptors of other vertebrates. We used tract tracing together with immunohistochemical markers for cholinergic cells (vesicular acetylcholine transporter [VAChT]), tyrosine hydroxylase (TH; the rate-limiting enzyme in catecholamine synthesis), and serotonin (5HT) to identify putative oxygen-sensing cells and to determine their anatomical relation to branches of the vagus nerve (Xth cranial nerve). We found potential oxygen-sensing cells in all three chemosensory areas innervated by branches of the Xth cranial nerve. Cells containing either 5HT or VAChT were found in all three sites. The morphology and size of these cells resemble glomus cells found in amphibians, mammals, tortoises, and lizards. Furthermore, we found populations of cholinergic cells located at the base of the aorta and pulmonary artery that are likely involved in efferent regulation of vessel resistance. Catecholamine-containing cells were not found in any of the putative chemosensitive areas. The presence of 5HT- and VAChT-immunoreactive cells in segments of the common carotid artery, aorta, and pulmonary artery appears to reflect a transition between cells containing the major neurotransmitters seen in fish (5HT) and mammals (ACh and adenosine). © 2015 Wiley Periodicals, Inc.

Isolation and characterization of human CXCR4-positive pancreatic cells.

PubMed

Koblas, T; Zacharovová, K; Berková, Z; Mindlová, M; Girman, P; Dovolilová, E; Karasová, L; Saudek, F

2007-01-01

The existence of an adult PSC that may be used in the treatment of diabetes is still a matter of scientific debate as conclusive evidence of such a stem cell in the adult pancreas has not yet been presented. The main reason why putative PSC has not yet been identified is the lack of specific markers that may be used to isolate and purify them. In order to increase the list of potential PSC markers we have focused on the human pancreatic cells that express cell surface receptor CXCR4, a marker of stem cells derived from different adult tissues. Here we report that CXCR4-positive pancreatic cells express markers of pancreatic endocrine progenitors (neurogenin-3, nestin) and markers of pluripotent stem cells (Oct-4, Nanog, ABCG2, CD133, CD117). Upon in vitro differentiation, these cells form ILCC and produce key islet hormones including insulin. Based on our results, we assume that CXCR4 marks pancreatic endocrine progenitors and in combination with other cell surface markers may be used in the attempt to identify and isolate PSC.

Studies of the expression of human poly(ADP-ribose) polymerase-1 in Saccharomyces cerevisiae and identification of PARP-1 substrates by yeast proteome microarray screening.

PubMed

Tao, Zhihua; Gao, Peng; Liu, Hung-Wen

2009-12-15

Poly(ADP-ribosyl)ation of various nuclear proteins catalyzed by a family of NAD(+)-dependent enzymes, poly(ADP-ribose) polymerases (PARPs), is an important posttranslational modification reaction. PARP activity has been demonstrated in all types of eukaryotic cells with the exception of yeast, in which the expression of human PARP-1 was shown to lead to retarded cell growth. We investigated the yeast growth inhibition caused by human PARP-1 expression in Saccharomyces cerevisiae. Flow cytometry analysis reveals that PARP-1-expressing yeast cells accumulate in the G(2)/M stage of the cell cycle. Confocal microscopy analysis shows that human PARP-1 is distributed throughout the nucleus of yeast cells but is enriched in the nucleolus. Utilizing yeast proteome microarray screening, we identified 33 putative PARP-1 substrates, six of which are known to be involved in ribosome biogenesis. The poly(ADP-ribosyl)ation of three of these yeast proteins, together with two human homologues, was confirmed by an in vitro PARP-1 assay. Finally, a polysome profile analysis using sucrose gradient ultracentrifugation demonstrated that the ribosome levels in yeast cells expressing PARP-1 are lower than those in control yeast cells. Overall, our data suggest that human PARP-1 may affect ribosome biogenesis by modifying certain nucleolar proteins in yeast. The artificial PARP-1 pathway in yeast may be used as a simple platform to identify substrates and verify function of this important enzyme.

Mary Jane Hogue (1883-1962): A pioneer in human brain tissue culture.

PubMed

Zottoli, Steven J; Seyfarth, Ernst-August

2018-05-16

The ability to maintain human brain explants in tissue culture was a critical step in the use of these cells for the study of central nervous system disorders. Ross G. Harrison (1870-1959) was the first to successfully maintain frog medullary tissue in culture in 1907, but it took another 38 years before successful culture of human brain tissue was accomplished. One of the pioneers in this achievement was Mary Jane Hogue (1883-1962). Hogue was born into a Quaker family in 1883 in West Chester, Pennsylvania, and received her undergraduate degree from Goucher College in Baltimore, Maryland. Research with the developmental biologist Theodor Boveri (1862-1915) in Würzburg, Germany, resulted in her Ph.D. (1909). Hogue transitioned from studying protozoa to the culture of human brain tissue in the 1940s and 1950s, when she was one of the first to culture cells from human fetal, infant, and adult brain explants. We review Hogue's pioneering contributions to the study of human brain cells in culture, her putative identification of progenitor neuroblast and/or glioblast cells, and her use of the cultures to study the cytopathogenic effects of poliovirus. We also put Hogue's work in perspective by discussing how other women pioneers in tissue culture influenced Hogue and her research.

Human embryonic stem cell therapies for neurodegenerative diseases.

PubMed

Tomaskovic-Crook, Eva; Crook, Jeremy M

2011-06-01

There is a renewed enthusiasm for the clinical translation of human embryonic stem (hES) cells. This is abetted by putative clinically-compliant strategies for hES cell maintenance and directed differentiation, greater understanding of and accessibility to cells through formal cell registries and centralized cell banking for distribution, the revised US government policy on funding hES cell research, and paradoxically the discovery of induced pluripotent stem (iPS) cells. Additionally, as we consider the constraints (practical and fiscal) of delivering cell therapies for global healthcare, the more efficient and economical application of allogeneic vs autologous treatments will bolster the clinical entry of hES cell derivatives. Neurodegenerative disorders such as Parkinson's disease are primary candidates for hES cell therapy, although there are significant hurdles to be overcome. The present review considers key advances and challenges to translating hES cells into novel therapies for neurodegenerative diseases, with special consideration given to Parkinson's disease and Alzheimer's disease. Importantly, despite the focus on degenerative brain disorders and hES cells, many of the issues canvassed by this review are relevant to systemic application of hES cells and other pluripotent stem cells such as iPS cells.

The status of the art of human malignant glioma management: the promising role of targeting tumor-initiating cells.

PubMed

Florio, Tullio; Barbieri, Federica

2012-10-01

Glioblastoma is the most prevalent and malignant form of brain cancer, but the current available multimodality treatments yield poor survival improvement. Thus, innovative therapeutic strategies represent the challenging topic for glioblastoma management. Multidisciplinary advances, supporting current standard of care therapies and investigational trials that reveal potential drug targets for glioblastoma are reviewed. A radical change in glioblastoma therapeutic approaches could arise from the identification of cancer stem cells, putative tumor-initiating cells involved in tumor initiation, progression and resistance, as innovative drug target. Still controversial identification of markers and molecular regulators in glioma tumor-initiating cells and novel approaches targeting these cells are discussed. Copyright © 2012 Elsevier Ltd. All rights reserved.

Gut Microbiome and Putative Resistome of Inca and Italian Nobility Mummies

PubMed Central

Santiago-Rodriguez, Tasha M.; Luciani, Stefania; Toranzos, Gary A.; Marota, Isolina; Giuffra, Valentina; Cano, Raul J.

2017-01-01

Little is still known about the microbiome resulting from the process of mummification of the human gut. In the present study, the gut microbiota, genes associated with metabolism, and putative resistome of Inca and Italian nobility mummies were characterized by using high-throughput sequencing. The Italian nobility mummies exhibited a higher bacterial diversity as compared to the Inca mummies when using 16S ribosomal (rRNA) gene amplicon sequencing, but both groups showed bacterial and fungal taxa when using shotgun metagenomic sequencing that may resemble both the thanatomicrobiome and extant human gut microbiomes. Identification of sequences associated with plants, animals, and carbohydrate-active enzymes (CAZymes) may provide further insights into the dietary habits of Inca and Italian nobility mummies. Putative antibiotic-resistance genes in the Inca and Italian nobility mummies support a human gut resistome prior to the antibiotic therapy era. The higher proportion of putative antibiotic-resistance genes in the Inca compared to Italian nobility mummies may support the hypotheses that a greater exposure to the environment may result in a greater acquisition of antibiotic-resistance genes. The present study adds knowledge of the microbiome resulting from the process of mummification of the human gut, insights of ancient dietary habits, and the preserved putative human gut resistome prior the antibiotic therapy era. PMID:29112136

Gut Microbiome and Putative Resistome of Inca and Italian Nobility Mummies.

PubMed

Santiago-Rodriguez, Tasha M; Fornaciari, Gino; Luciani, Stefania; Toranzos, Gary A; Marota, Isolina; Giuffra, Valentina; Cano, Raul J

2017-11-07

Little is still known about the microbiome resulting from the process of mummification of the human gut. In the present study, the gut microbiota, genes associated with metabolism, and putative resistome of Inca and Italian nobility mummies were characterized by using high-throughput sequencing. The Italian nobility mummies exhibited a higher bacterial diversity as compared to the Inca mummies when using 16S ribosomal (rRNA) gene amplicon sequencing, but both groups showed bacterial and fungal taxa when using shotgun metagenomic sequencing that may resemble both the thanatomicrobiome and extant human gut microbiomes. Identification of sequences associated with plants, animals, and carbohydrate-active enzymes (CAZymes) may provide further insights into the dietary habits of Inca and Italian nobility mummies. Putative antibiotic-resistance genes in the Inca and Italian nobility mummies support a human gut resistome prior to the antibiotic therapy era. The higher proportion of putative antibiotic-resistance genes in the Inca compared to Italian nobility mummies may support the hypotheses that a greater exposure to the environment may result in a greater acquisition of antibiotic-resistance genes. The present study adds knowledge of the microbiome resulting from the process of mummification of the human gut, insights of ancient dietary habits, and the preserved putative human gut resistome prior the antibiotic therapy era.

Role of gonadotropin-releasing hormone (GnRH) in ovarian cancer

PubMed Central

Gründker, Carsten; Emons, Günter

2003-01-01

The expression of GnRH (GnRH-I, LHRH) and its receptor as a part of an autocrine regulatory system of cell proliferation has been demonstrated in a number of human malignant tumors, including cancers of the ovary. The proliferation of human ovarian cancer cell lines is time- and dose-dependently reduced by GnRH and its superagonistic analogs. The classical GnRH receptor signal-transduction mechanisms, known to operate in the pituitary, are not involved in the mediation of antiproliferative effects of GnRH analogs in these cancer cells. The GnRH receptor rather interacts with the mitogenic signal transduction of growth-factor receptors and related oncogene products associated with tyrosine kinase activity via activation of a phosphotyrosine phosphatase resulting in downregulation of cancer cell proliferation. In addition GnRH activates nucleus factor κB (NFκB) and protects the cancer cells from apoptosis. Furthermore GnRH induces activation of the c-Jun N-terminal kinase/activator protein-1 (JNK/AP-1) pathway independent of the known AP-1 activators, protein kinase (PKC) or mitogen activated protein kinase (MAPK/ERK). Recently it was shown that human ovarian cancer cells express a putative second GnRH receptor specific for GnRH type II (GnRH-II). The proliferation of these cells is dose- and time-dependently reduced by GnRH-II in a greater extent than by GnRH-I (GnRH, LHRH) superagonists. In previous studies we have demonstrated that in ovarian cancer cell lines except for the EFO-27 cell line GnRH-I antagonist Cetrorelix has comparable antiproliferative effects as GnRH-I agonists indicating that the dichotomy of GnRH-I agonists and antagonists might not apply to the GnRH-I system in cancer cells. After GnRH-I receptor knock down the antiproliferative effects of GnRH-I agonist Triptorelin were abrogated while the effects of GnRH-I antagonist Cetrorelix and GnRH-II were still existing. In addition, in the ovarian cancer cell line EFO-27 GnRH-I receptor but not putative GnRH-II receptor expression was found. These data suggest that in ovarian cancer cells the antiproliferative effects of GnRH-I antagonist Cetrorelix and GnRH-II are not mediated through the GnRH-I receptor. PMID:14594454

Human endogenous retroviruses: nature, occurrence, and clinical implications in human disease.

PubMed Central

Urnovitz, H B; Murphy, W H

1996-01-01

Retroviral diagnostics have become standard in human laboratory medicine. While current emphasis is placed on the human exogenous viruses (human immunodeficiency virus and human T-cell leukemia virus), evidence implicating human endogenous retroviruses (HERVs) in various human disease entities continues to mount. Literature on the occurrence of HERVs in human tissues and cells was analyzed. Substantial evidence documents that retrovirus particles were clearly demonstrable in various tissues and cells in both health and disease and were abundant in the placenta and that their occurrence could be implicated in some of the reproductive diseases. The characteristics of HERVs are summarized, mechanisms of replication and regulation are outlined, and the consistent hormonal responsiveness of HERVs is noted. Clear evidence implicating HERV gene products as participants in glomerulonephritis in some cases of systemic lupus erythematosus is adduced. Data implicating HERVs as etiologic factors in reproductive diseases, in some of the autoimmune diseases, in some forms of rheumatoid arthritis and connective tissue disease, in psoriasis, and in some of the inflammatory neurologic diseases are reviewed. The current major needs are to improve methods for HERV detection, to identify the most appropriate HERV prototypes, and to develop diagnostic reagents so that the putative biologic and pathologic roles of HERVs can be better evaluated. PMID:8665478

Mapping of the minimal inorganic phosphate transporting unit of human PiT2 suggests a structure universal to PiT-related proteins from all kingdoms of life

PubMed Central

2011-01-01

Background The inorganic (Pi) phosphate transporter (PiT) family comprises known and putative Na+- or H+-dependent Pi-transporting proteins with representatives from all kingdoms. The mammalian members are placed in the outer cell membranes and suggested to supply cells with Pi to maintain house-keeping functions. Alignment of protein sequences representing PiT family members from all kingdoms reveals the presence of conserved amino acids and that bacterial phosphate permeases and putative phosphate permeases from archaea lack substantial parts of the protein sequence when compared to the mammalian PiT family members. Besides being Na+-dependent Pi (NaPi) transporters, the mammalian PiT paralogs, PiT1 and PiT2, also are receptors for gamma-retroviruses. We have here exploited the dual-function of PiT1 and PiT2 to study the structure-function relationship of PiT proteins. Results We show that the human PiT2 histidine, H502, and the human PiT1 glutamate, E70, - both conserved in eukaryotic PiT family members - are critical for Pi transport function. Noticeably, human PiT2 H502 is located in the C-terminal PiT family signature sequence, and human PiT1 E70 is located in ProDom domains characteristic for all PiT family members. A human PiT2 truncation mutant, which consists of the predicted 10 transmembrane (TM) domain backbone without a large intracellular domain (human PiT2ΔR254-V483), was found to be a fully functional Pi transporter. Further truncation of the human PiT2 protein by additional removal of two predicted TM domains together with the large intracellular domain created a mutant that resembles a bacterial phosphate permease and an archaeal putative phosphate permease. This human PiT2 truncation mutant (human PiT2ΔL183-V483) did also support Pi transport albeit at very low levels. Conclusions The results suggest that the overall structure of the Pi-transporting unit of the PiT family proteins has remained unchanged during evolution. Moreover, in combination, our studies of the gene structure of the human PiT1 and PiT2 genes (SLC20A1 and SLC20A2, respectively) and alignment of protein sequences of PiT family members from all kingdoms, along with the studies of the dual functions of the human PiT paralogs show that these proteins are excellent as models for studying the evolution of a protein's structure-function relationship. PMID:21586110

Mapping of the minimal inorganic phosphate transporting unit of human PiT2 suggests a structure universal to PiT-related proteins from all kingdoms of life.

PubMed

Bøttger, Pernille; Pedersen, Lene

2011-05-17

The inorganic (Pi) phosphate transporter (PiT) family comprises known and putative Na(+)- or H(+)-dependent Pi-transporting proteins with representatives from all kingdoms. The mammalian members are placed in the outer cell membranes and suggested to supply cells with Pi to maintain house-keeping functions. Alignment of protein sequences representing PiT family members from all kingdoms reveals the presence of conserved amino acids and that bacterial phosphate permeases and putative phosphate permeases from archaea lack substantial parts of the protein sequence when compared to the mammalian PiT family members. Besides being Na(+)-dependent P(i) (NaP(i)) transporters, the mammalian PiT paralogs, PiT1 and PiT2, also are receptors for gamma-retroviruses. We have here exploited the dual-function of PiT1 and PiT2 to study the structure-function relationship of PiT proteins. We show that the human PiT2 histidine, H(502), and the human PiT1 glutamate, E(70),--both conserved in eukaryotic PiT family members--are critical for P(i) transport function. Noticeably, human PiT2 H(502) is located in the C-terminal PiT family signature sequence, and human PiT1 E(70) is located in ProDom domains characteristic for all PiT family members.A human PiT2 truncation mutant, which consists of the predicted 10 transmembrane (TM) domain backbone without a large intracellular domain (human PiT2ΔR(254)-V(483)), was found to be a fully functional P(i) transporter. Further truncation of the human PiT2 protein by additional removal of two predicted TM domains together with the large intracellular domain created a mutant that resembles a bacterial phosphate permease and an archaeal putative phosphate permease. This human PiT2 truncation mutant (human PiT2ΔL(183)-V(483)) did also support P(i) transport albeit at very low levels. The results suggest that the overall structure of the P(i)-transporting unit of the PiT family proteins has remained unchanged during evolution. Moreover, in combination, our studies of the gene structure of the human PiT1 and PiT2 genes (SLC20A1 and SLC20A2, respectively) and alignment of protein sequences of PiT family members from all kingdoms, along with the studies of the dual functions of the human PiT paralogs show that these proteins are excellent as models for studying the evolution of a protein's structure-function relationship. © 2011 Bøttger and Pedersen; licensee BioMed Central Ltd.

Large-Scale Identification and Characterization of Heterodera avenae Putative Effectors Suppressing or Inducing Cell Death in Nicotiana benthamiana

PubMed Central

Chen, Changlong; Chen, Yongpan; Jian, Heng; Yang, Dan; Dai, Yiran; Pan, Lingling; Shi, Fengwei; Yang, Shanshan; Liu, Qian

2018-01-01

Heterodera avenae is one of the most important plant pathogens and causes vast losses in cereal crops. As a sedentary endoparasitic nematode, H. avenae secretes effectors that modify plant defenses and promote its biotrophic infection of its hosts. However, the number of effectors involved in the interaction between H. avenae and host defenses remains unclear. Here, we report the identification of putative effectors in H. avenae that regulate plant defenses on a large scale. Our results showed that 78 of the 95 putative effectors suppressed programmed cell death (PCD) triggered by BAX and that 7 of the putative effectors themselves caused cell death in Nicotiana benthamiana. Among the cell-death-inducing effectors, three were found to be dependent on their specific domains to trigger cell death and to be expressed in esophageal gland cells by in situ hybridization. Ten candidate effectors that suppressed BAX-triggered PCD also suppressed PCD triggered by the elicitor PsojNIP and at least one R-protein/cognate effector pair, suggesting that they are active in suppressing both pattern-triggered immunity (PTI) and effector-triggered immunity (ETI). Notably, with the exception of isotig16060, these putative effectors could also suppress PCD triggered by cell-death-inducing effectors from H. avenae, indicating that those effectors may cooperate to promote nematode parasitism. Collectively, our results indicate that the majority of the tested effectors of H. avenae may play important roles in suppressing cell death induced by different elicitors in N. benthamiana. PMID:29379510

A small molecule-based strategy for endothelial differentiation and three-dimensional morphogenesis from human embryonic stem cells.

PubMed

Geng, Yijie; Feng, Bradley

2016-07-01

The emerging models of human embryonic stem cell (hESC) self-organizing organoids provide a valuable in vitro platform for studying self-organizing processes that presumably mimic in vivo human developmental events. Here we report that through a chemical screen, we identified two novel and structurally similar small molecules BIR1 and BIR2 which robustly induced the self-organization of a balloon-shaped three-dimensional structure when applied to two-dimensional adherent hESC cultures in the absence of growth factors. Gene expression analyses and functional assays demonstrated an endothelial identity of this balloon-like structure, while cell surface marker analyses revealed a VE-cadherin(+)CD31(+)CD34(+)KDR(+)CD43(-) putative endothelial progenitor population. Furthermore, molecular marker labeling and morphological examinations characterized several other distinct DiI-Ac-LDL(+) multi-cellular modules and a VEGFR3(+) sprouting structure in the balloon cultures that likely represented intermediate structures of balloon-formation.

The chronicles of Porphyromonas gingivalis: the microbium, the human oral epithelium and their interplay

PubMed Central

Yilmaz, Özlem

2009-01-01

The microbiota of the human oral mucosa consists of a myriad of bacterial species that normally exist in commensal harmony with the host. Porphyromonas gingivalis, an aetiological agent in severe forms of periodontitis (a chronic inflammatory disease), is a prominent component of the oral microbiome and a successful colonizer of the oral epithelium. This Gram-negative anaerobe can also exist within the host epithelium without the existence of overt disease. Gingival epithelial cells, the outer lining of the gingival mucosa, which function as an important part of the innate immune system, are among the first host cells colonized by P. gingivalis. This review describes recent studies implicating the co-existence and intracellular adaptation of the organism in these target host cells. Specifically, recent findings on the putative mechanisms of persistence, intercellular dissemination and opportunism are highlighted. These new findings may also represent an original and valuable model for mechanistic characterization of other successful host-adapted, self-limiting, persistent intracellular bacteria in human epithelial tissues. PMID:18832296

The chronicles of Porphyromonas gingivalis: the microbium, the human oral epithelium and their interplay.

PubMed

Yilmaz, Ozlem

2008-10-01

The microbiota of the human oral mucosa consists of a myriad of bacterial species that normally exist in commensal harmony with the host. Porphyromonas gingivalis, an aetiological agent in severe forms of periodontitis (a chronic inflammatory disease), is a prominent component of the oral microbiome and a successful colonizer of the oral epithelium. This Gram-negative anaerobe can also exist within the host epithelium without the existence of overt disease. Gingival epithelial cells, the outer lining of the gingival mucosa, which function as an important part of the innate immune system, are among the first host cells colonized by P. gingivalis. This review describes recent studies implicating the co-existence and intracellular adaptation of the organism in these target host cells. Specifically, recent findings on the putative mechanisms of persistence, intercellular dissemination and opportunism are highlighted. These new findings may also represent an original and valuable model for mechanistic characterization of other successful host-adapted, self-limiting, persistent intracellular bacteria in human epithelial tissues.

The Human Cell Surfaceome of Breast Tumors

PubMed Central

da Cunha, Júlia Pinheiro Chagas; Galante, Pedro Alexandre Favoretto; de Souza, Jorge Estefano Santana; Pieprzyk, Martin; Carraro, Dirce Maria; Old, Lloyd J.; Camargo, Anamaria Aranha; de Souza, Sandro José

2013-01-01

Introduction. Cell surface proteins are ideal targets for cancer therapy and diagnosis. We have identified a set of more than 3700 genes that code for transmembrane proteins believed to be at human cell surface. Methods. We used a high-throuput qPCR system for the analysis of 573 cell surface protein-coding genes in 12 primary breast tumors, 8 breast cell lines, and 21 normal human tissues including breast. To better understand the role of these genes in breast tumors, we used a series of bioinformatics strategies to integrates different type, of the datasets, such as KEGG, protein-protein interaction databases, ONCOMINE, and data from, literature. Results. We found that at least 77 genes are overexpressed in breast primary tumors while at least 2 of them have also a restricted expression pattern in normal tissues. We found common signaling pathways that may be regulated in breast tumors through the overexpression of these cell surface protein-coding genes. Furthermore, a comparison was made between the genes found in this report and other genes associated with features clinically relevant for breast tumorigenesis. Conclusions. The expression profiling generated in this study, together with an integrative bioinformatics analysis, allowed us to identify putative targets for breast tumors. PMID:24195083

Rapid tissue engineering of biomimetic human corneal limbal crypts with 3D niche architecture.

PubMed

Levis, Hannah J; Massie, Isobel; Dziasko, Marc A; Kaasi, Andreas; Daniels, Julie T

2013-11-01

Limbal epithelial stem cells are responsible for the maintenance of the human corneal epithelium and these cells reside in a specialised stem cell niche. They are located at the base of limbal crypts, in a physically protected microenvironment in close proximity to a variety of neighbouring niche cells. Design and recreation of elements of various stem cell niches have allowed researchers to simplify aspects of these complex microenvironments for further study in vitro. We have developed a method to rapidly and reproducibly create bioengineered limbal crypts (BLCs) in a collagen construct using a simple one-step method. Liquid is removed from collagen hydrogels using hydrophilic porous absorbers (HPAs) that have custom moulded micro-ridges on the base. The resulting topography on the surface of the thin collagen constructs resembles the dimensions of the stromal crypts of the human limbus. Human limbal epithelial cells seeded onto the surface of the constructs populate these BLCs and form numerous layers with a high proportion of the cells lining the crypts expressing putative stem cell marker, p63α. The HPAs are produced using a moulding process that is flexible and can be adapted depending on the requirements of the end user. Creation of defined topographical features using this process could be applicable to numerous tissue-engineering applications where varied 3-dimensional niche architectures are required. Copyright © 2013 Elsevier Ltd. All rights reserved.

Epigenetics of prostate cancer and the prospect of identification of novel drug targets by RNAi screening of epigenetic enzymes.

PubMed

Björkman, Mari; Rantala, Juha; Nees, Matthias; Kallioniemi, Olli

2010-10-01

Alterations in epigenetic processes probably underlie most human malignancies. Novel genome-wide techniques, such as chromatin immunoprecipitation and high-throughput sequencing, have become state-of-the-art methods to map the epigenomic landscape of development and disease, such as in cancers. Despite these advances, the functional significance of epigenetic enzymes in cancer progression, such as prostate cancer, remain incompletely understood. A comprehensive mapping and functional understanding of the cancer epigenome will hopefully help to facilitate development of novel cancer therapy targets and improve future diagnostics. The authors have developed a novel cell microarray-based high-content siRNA screening technique suitable to address the putative functional role and impact of all known putative and novel epigenetic enzymes in cancer, including prostate cancer.

Basal cell adhesion molecule/lutheran protein. The receptor critical for sickle cell adhesion to laminin.

PubMed Central

Udani, M; Zen, Q; Cottman, M; Leonard, N; Jefferson, S; Daymont, C; Truskey, G; Telen, M J

1998-01-01

Sickle red cells bind significant amounts of soluble laminin, whereas normal red cells do not. Solid phase assays demonstrate that B-CAM/LU binds laminin on intact sickle red cells and that red cell B-CAM/LU binds immobilized laminin, whereas another putative laminin binding protein, CD44, does not. Ligand blots also identify B-CAM/LU as the only erythrocyte membrane protein(s) that binds laminin. Finally, transfection of murine erythroleukemia cells with human B-CAM cDNA induces binding of both soluble and immobilized laminin. Thus, B-CAM/LU appears to be the major laminin-binding protein of sickle red cells. Previously reported overexpression of B-CAM/LU by epithelial cancer cells suggests that this protein may also serve as a laminin receptor in malignant tumors. PMID:9616226

Demonstration of intermediate cells during human prostate epithelial differentiation in situ and in vitro using triple-staining confocal scanning microscopy.

PubMed

van Leenders, G; Dijkman, H; Hulsbergen-van de Kaa, C; Ruiter, D; Schalken, J

2000-08-01

In human prostate epithelium, morphologically basal and luminal cells can be discriminated. The basal cell layer that putatively contains progenitor cells of the secretory epithelium is characterized by the expression of keratins (K) 5 and 14. Luminal cells represent the secretory compartment of the epithelium and express K8 and 18. We developed a technique for the simultaneous analysis of K5, 14, and 18 to identify intermediate cell stages in the prostate epithelium and to study the dynamic aspects of its differentiation in vitro. Nonmalignant prostate tissue and primary epithelial cultures were immunohistochemically characterized using triple staining with antibodies for K5, K14, and K18. Antibodies for K18 and K5 were conjugated directly with fluorochromes Alexa 488 and 546. K14 was visualized indirectly with streptavidin-Cy5. Keratin expression was analyzed by confocal scanning microscopy. The occurrence of exocrine and neuroendocrine differentiation in culture was determined via antibodies to prostate-specific antigen (PSA), chromogranin A, and serotonin. We found that basal cells expressed either K5(++)/14(++)/18+ or K5(++)/18+. The majority of luminal cells expressed K18(++), but colocalization of K5+/18(++) were recognized. Epithelial monolayer cultures predominantly revealed the basal cell phenotype K5(++)/14(++)/18+, whereas intermediate subpopulations expressing K5+/14+/18(++) and K5+/18(++) were also identified. On confluence, differentiation was induced as multicellular gland-like buds, and extensions became evident on top of the monolayer. These structures were composed of K18(++)- and K5+/18(+)-positive cell clusters surrounded by phenotypically basal cells. Few multicellular structures and cells in the monolayer showed exocrine differentiation (PSA+), but expression of chromogranin A and serotonin was absent. We conclude that simultaneous evaluation of keratin expression is useful for analyzing epithelial differentiation in the prostate. During this process, putative stem cells phenotypically resembling K5(++)/14(++)/18+ differentiate toward luminal cells (K18(++)) via intermediate cell stages, as identified by up-regulation of K18 and down-regulation of K5 and 14.

Impact of the putative cancer stem cell markers and growth factor receptor expression on the sensitivity of ovarian cancer cells to treatment with various forms of small molecule tyrosine kinase inhibitors and cytotoxic drugs.

PubMed

Puvanenthiran, Soozana; Essapen, Sharadah; Seddon, Alan M; Modjtahedi, Helmout

2016-11-01

Increased expression and activation of human epidermal growth factor receptor (EGFR) and HER-2 have been reported in numerous cancers. The aim of this study was to determine the sensitivity of a large panel of human ovarian cancer cell lines (OCCLs) to treatment with various forms of small molecule tyrosine kinase inhibitors (TKIs) and cytotoxic drugs. The aim was to see if there was any association between the protein expression of various biomarkers including three putative ovarian cancer stem cell (CSC) markers (CD24, CD44, CD117/c-Kit), P-glycoprotein (P-gp), and HER family members and response to treatment with these agents. The sensitivity of 10 ovarian tumour cell lines to the treatment with various forms of HER TKIs (gefitinib, erlotinib, lapatinib, sapitinib, afatinib, canertinib, neratinib), as well as other TKIs (dasatinib, imatinib, NVP-AEW541, crizotinib) and cytotoxic agents (paclitaxel, cisplatin and doxorubicin), as single agents or in combination, was determined by SRB assay. The effect on these agents on the cell cycle distribution, and downstream signaling molecules and tumour migration were determined using flow cytometry, western blotting, and the IncuCyte Clear View cell migration assay respectively. Of the HER inhibitors, the irreversible pan-TKIs (canertinib, neratinib and afatinib) were the most effective TKIs for inhibiting the growth of all ovarian cancer cells, and for blocking the phosphorylation of EGFR, HER-2, AKT and MAPK in SKOV3 cells. Interestingly, while the majority of cancer cells were highly sensitive to treatment with dasatinib, they were relatively resistant to treatment with imatinib (i.e., IC50 >10 µM). Of the cytotoxic agents, paclitaxel was the most effective for inhibiting the growth of OCCLs, and of various combinations of these drugs, only treatment with a combination of NVP-AEW541 and paclitaxel produced a synergistic or additive anti-proliferative effect in all three cell lines examined (i.e., SKOV3, Caov3, ES2). Finally, of the TKIs, only treatment with afatinib, neratinib and dasatinib were able to reduce the migration of HER-2 overexpressing SKOV3 cells. We did not find any significant association between the expression of putative ovarian CSC marker, HER family members, c-MET, ALK, and IGF-IR and the response to the irreversible HER TKIs. Our results support the need for further investigations of the therapeutic potential of these irreversible HER family blockers in ovarian cancer, and the therapeutic potential of dasatinib when used in combination with the inhibitors of the HER family members in ovarian cancer.

TM6SF2 is a regulator of liver fat metabolism influencing triglyceride secretion and hepatic lipid droplet content

PubMed Central

Mahdessian, Hovsep; Taxiarchis, Apostolos; Popov, Sergej; Silveira, Angela; Franco-Cereceda, Anders; Hamsten, Anders; Eriksson, Per; van't Hooft, Ferdinand

2014-01-01

Genome-wide association studies have identified a locus on chromosome 19 associated with plasma triglyceride (TG) concentration and nonalcoholic fatty liver disease. However, the identity and functional role of the gene(s) responsible for these associations remain unknown. Of 19 expressed genes contained in this locus, none has previously been implicated in lipid metabolism. We performed gene expression studies and expression quantitative trait locus analysis in 206 human liver samples to identify the putative causal gene. Transmembrane 6 superfamily member 2 (TM6SF2), a gene with hitherto unknown function, expressed predominantly in liver and intestine, was identified as the putative causal gene. TM6SF2 encodes a protein of 351 amino acids with 7–10 predicted transmembrane domains. Otherwise, no other protein features were identified which could help to elucidate the function of TM6SF2. Protein subcellular localization studies with confocal microscopy demonstrated that TM6SF2 is localized in the endoplasmic reticulum and the ER-Golgi intermediate compartment of human liver cells. Functional studies for secretion of TG-rich lipoproteins (TRLs) and lipid droplet content were performed in human hepatoma Huh7 and HepG2 cells using confocal microscopy and siRNA inhibition and overexpression techniques. In agreement with the genome-wide association data, it was found that TM6SF2 siRNA inhibition was associated with reduced secretion of TRLs and increased cellular TG concentration and lipid droplet content, whereas TM6SF2 overexpression reduced liver cell steatosis. We conclude that TM6SF2 is a regulator of liver fat metabolism with opposing effects on the secretion of TRLs and hepatic lipid droplet content. PMID:24927523

Composite fatty acid ether amides suppress growth of liver cancer cells in vitro and in an in vivo allograft mouse model.

PubMed

Cao, Mengde; Prima, Victor; Nelson, David; Svetlov, Stanislav

2013-06-01

The heterogeneity of liver cancer, in particular hepatocellular carcinoma (HCC), portrays the requirement of multiple targets for both its treatment and prevention. Multifaceted agents, minimally or non-toxic for normal hepatocytes, are required to address the molecular diversity of HCC, including the resistance of putative liver cancer stem cells to chemotherapy. We designed and synthesized two fatty acid ethers of isopropylamino propanol, C16:0-AIP-1 and C18:1-AIP-2 (jointly named AIPs), and evaluated their anti-proliferative effects on the human HCC cell line Huh7 and the murine hepatoma cell line BNL 1MEA.7R.1, both in vitro and in an in vivo allograft mouse model. We found that AIP-1 and AIP-2 inhibited proliferation and caused cell death in both Huh7 and BNL 1MEA.7R.1 cells. Importantly, AIP-1 and AIP-2 were found to block the activation of putative liver cancer stem cells as manifested by suppression of clonal 'carcinosphere' development in growth factor-free and anchorage-free medium. The AIPs exhibited a relatively low toxicity against normal human or rat hepatocytes in primary cultures. In addition, we found that the AIPs utilized multifaceted pathways that mediate both autophagy and apoptosis in HCC, including the inhibition of AKTs and CAMK-1. In immune-competent mice, the AIPs significantly reduced BNL 1MEA.7R.1 cell-driven tumor allograft development, with a higher efficiency than sorafenib. A combination of AIP-1 + AIP-2 was most effective in reducing the tumor allograft incidence. AIPs represent a novel class of simple fatty acid derivatives that are effective against liver tumors via diverse pathways. They show a low toxicity towards normal hepatocytes. The addition of AIPs may represent a new avenue towards the management of chronic liver injury and, ultimately, the prevention and treatment of HCC.

Multiple splicing events involved in regulation of human aromatase expression by a novel promoter, I.6.

PubMed

Shozu, M; Zhao, Y; Bulun, S E; Simpson, E R

1998-04-01

The expression of aromatase is regulated in a tissue-specific fashion through alternative use of multiple promoter-specific first exons. To date, eight different first exons have been reported in human aromatase, namely I.1., I.2, I.3. I.4, I.5, PII, 2a, and 1f. Recently, we have found a new putative exon I in a RACE-generated library of THP-1 cells and have conducted studies to characterize this new exon I. We confirmed that the constructs containing -1552/+17 or less flanking sequence of this exon function as a promoter in THP-1 cells, JEG-3 cells and osteoblast-like cells obtained from a human fetus. Results of transfection assays using a series of deletion constructs and mutation constructs indicate that a 1-bp mismatch of the consensus TATA-like box (TTTAAT) and the consensus sequence of the initiator site, which is located 45 bp downstream of the putative TATA box, were functioning cooperatively as a core promoter. The putative transcription site was confirmed by the results of RT-PCR southern blot analysis. We examined the regulation and the expression of this exon, I.6, in several human cells and tissues by RT-PCR Southern blot analysis. THP-1 cells (mononuclear leukemic origin) and JEG-3 cells (choriocarcinoma origin) expressed exon I.6 in serum-free media. The level of expression was increased by serum and phorbol myristyl acetate (PMA) in both cell lines. Adipose stromal cells also expressed exon I.6 in the presence of PMA. In fetal osteoblasts, the expression of exon I.6 was increased most effectively by serum and less so by dexamethasone (DEX) + IL-1beta and DEX + IL-11, whereas induction by serum was suppressed by the addition of DEX. The level of expression was low in granulosa cells in culture and did not change with forskolin. On the other hand, dibutyryl cAMP suppressed PMA-stimulated expression of exon I.6 in THP-1 cells and adipose stromal cells. This result supports the hypothesis that the expression of exon I.6 is regulated mainly via an AP-1 binding site that is found upstream of the initiator site of the promoter region. Expression of exon I.6-specific transcripts was examined in several human tissues. Testis and bone obtained from normal adults expressed exon I.6. Testicular tumor and hepatic carcinoma expressed high levels of exon I.6, whereas granulosa cell tumor did not. Fetal liver and bone also showed a significant level of exon I.6 expression, but not so much as testicular tumor and hepatic tumor. Several splicing variants of exon I.6 were detected especially in THP-1 and JEG-3 cells, and to a lesser extent in primary cultures and tissue samples. These variants were identified as an unspliced form, a form spliced at the end of exon I.4, a form spliced at the end of exon I.3 (truncated) and a form spliced 220 bp downstream of the 3' end of exon I.6. The last variant revealed a new splicing site. Because most of the splicing variants contain the sequence specific for exon I.3, RT-PCR specific for exon I.3 can coamplify these splicing variants of exon I.6 transcripts. These results suggests that it is necessary to examine the expression of I.6 in tissues that are known to express exon I.3 such as breast adipose tissue, in which promoter usage of exon I of the aromatase gene switches from exon I.4 to I.3 in the course of malignant transformation.

Analysis of close associations of uropod-associated proteins in human T-cells using the proximity ligation assay

PubMed Central

Baumann, Tommy; Affentranger, Sarah

2013-01-01

We have shown previously that the raft-associated proteins flotillin-1 and -2 are rapidly recruited to the uropods of chemoattractant-stimulated human neutrophils and T-cells and are involved in cell polarization. Other proteins such as the adhesion receptor PSGL-1, the actin-membrane linker proteins ezrin/radixin/moesin (ERM) and the signaling enzyme phosphatidylinositol-4-phosphate 5-kinase type Iγ90 (PIPKIγ90) also accumulate in the T-cell uropod. Using the in situ proximity ligation assay (PLA) we now have investigated putative close associations of these proteins in human freshly isolated T-cells before and after chemokine addition. The PLA allows in situ subcellular localization of close proximity of endogenous proteins at single-molecule resolution in fixed cells. It allows detection also of weaker and transient complexes that would not be revealed with co-immunoprecipitation approaches. We previously provided evidence for heterodimer formation of tagged flotillin-1 and -2 in T-cells before and after chemokine addition using fluorescence resonance energy transfer (FRET). We now confirm these findings using PLA for the endogenous flotillins in fixed human T-cells. Moreover, in agreement with the literature, our PLA findings confirm a close association of endogenous PSGL-1 and ERM proteins both in resting and chemokine-activated human T-cells. In addition, we provide novel evidence using the PLA for close associations of endogenous activated ERM proteins with PIPKIγ90 and of endogenous flotillins with PSGL-1 in human T-cells, before and after chemokine addition. Our findings suggest that preformed clusters of these proteins coalesce in the uropod upon cell stimulation. PMID:24167781

Isolation and characterization of high affinity aptamers against DNA polymerase iota.

PubMed

Lakhin, Andrei V; Kazakov, Andrei A; Makarova, Alena V; Pavlov, Yuri I; Efremova, Anna S; Shram, Stanislav I; Tarantul, Viacheslav Z; Gening, Leonid V

2012-02-01

Human DNA-polymerase iota (Pol ι) is an extremely error-prone enzyme and the fidelity depends on the sequence context of the template. Using the in vitro systematic evolution of ligands by exponential enrichment (SELEX) procedure, we obtained an oligoribonucleotide with a high affinity to human Pol ι, named aptamer IKL5. We determined its dissociation constant with homogenous preparation of Pol ι and predicted its putative secondary structure. The aptamer IKL5 specifically inhibits DNA-polymerase activity of the purified enzyme Pol ι, but did not inhibit the DNA-polymerase activities of human DNA polymerases beta and kappa. IKL5 suppressed the error-prone DNA-polymerase activity of Pol ι also in cellular extracts of the tumor cell line SKOV-3. The aptamer IKL5 is useful for studies of the biological role of Pol ι and as a potential drug to suppress the increase of the activity of this enzyme in malignant cells.

Adult Human Neurogenesis: From Microscopy to Magnetic Resonance Imaging

PubMed Central

Sierra, Amanda; Encinas, Juan M.; Maletic-Savatic, Mirjana

2011-01-01

Neural stem cells reside in well-defined areas of the adult human brain and are capable of generating new neurons throughout the life span. In rodents, it is well established that the new born neurons are involved in olfaction as well as in certain forms of memory and learning. In humans, the functional relevance of adult human neurogenesis is being investigated, in particular its implication in the etiopathology of a variety of brain disorders. Adult neurogenesis in the human brain was discovered by utilizing methodologies directly imported from the rodent research, such as immunohistological detection of proliferation and cell-type specific biomarkers in postmortem or biopsy tissue. However, in the vast majority of cases, these methods do not support longitudinal studies; thus, the capacity of the putative stem cells to form new neurons under different disease conditions cannot be tested. More recently, new technologies have been specifically developed for the detection and quantification of neural stem cells in the living human brain. These technologies rely on the use of magnetic resonance imaging, available in hospitals worldwide. Although they require further validation in rodents and primates, these new methods hold the potential to test the contribution of adult human neurogenesis to brain function in both health and disease. This review reports on the current knowledge on adult human neurogenesis. We first review the different methods available to assess human neurogenesis, both ex vivo and in vivo and then appraise the changes of adult neurogenesis in human diseases. PMID:21519376

Deregulation of the CEACAM expression pattern causes undifferentiated cell growth in human lung adenocarcinoma cells.

PubMed

Singer, Bernhard B; Scheffrahn, Inka; Kammerer, Robert; Suttorp, Norbert; Ergun, Suleyman; Slevogt, Hortense

2010-01-18

CEACAM1, CEA/CEACAM5, and CEACAM6 are cell adhesion molecules (CAMs) of the carcinoembryonic antigen (CEA) family that have been shown to be deregulated in lung cancer and in up to 50% of all human cancers. However, little is known about the functional impact of these molecules on undifferentiated cell growth and tumor progression. Here we demonstrate that cell surface expression of CEACAM1 on confluent A549 human lung adenocarcinoma cells plays a critical role in differentiated, contact-inhibited cell growth. Interestingly, CEACAM1-L, but not CEACAM1-S, negatively regulates proliferation via its ITIM domain, while in proliferating cells no CEACAM expression is detectable. Furthermore, we show for the first time that CEACAM6 acts as an inducer of cellular proliferation in A549 cells, likely by interfering with the contact-inhibiting signal triggered by CEACAM1-4L, leading to undifferentiated anchorage-independent cell growth. We also found that A549 cells expressed significant amounts of non-membrane anchored variants of CEACAM5 and CEACAM6, representing a putative source for the increased CEACAM5/6 serum levels frequently found in lung cancer patients. Taken together, our data suggest that post-confluent contact inhibition is established and maintained by CEACAM1-4L, but disturbances of CEACAM1 signalling by CEACAM1-4S and other CEACAMs lead to undifferentiated cell growth and malignant transformation.

Systemic Problems: A perspective on stem cell aging and rejuvenation.

PubMed

Conboy, Irina M; Conboy, Michael J; Rebo, Justin

2015-10-01

This review provides balanced analysis of the advances in systemic regulation of young and old tissue stem cells and suggests strategies for accelerating development of therapies to broadly combat age-related tissue degenerative pathologies. Many highlighted recent reports on systemic tissue rejuvenation combine parabiosis with a "silver bullet" putatively responsible for the positive effects. Attempts to unify these papers reflect the excitement about this experimental approach and add value in reproducing previous work. At the same time, defined molecular approaches, which are "beyond parabiosis" for the rejuvenation of multiple old organs represent progress toward attenuating or even reversing human tissue aging.

Metformin repositioning as antitumoral agent: selective antiproliferative effects in human glioblastoma stem cells, via inhibition of CLIC1-mediated ion current

PubMed Central

Barbieri, Federica; Peretti, Marta; Pizzi, Erika; Pattarozzi, Alessandra; Carra, Elisa; Sirito, Rodolfo; Daga, Antonio; Curmi, Paul M.G.; Mazzanti, Michele; Florio, Tullio

2014-01-01

Epidemiological and preclinical studies propose that metformin, a first-line drug for type-2 diabetes, exerts direct antitumor activity. Although several clinical trials are ongoing, the molecular mechanisms of this effect are unknown. Here we show that chloride intracellular channel-1 (CLIC1) is a direct target of metformin in human glioblastoma cells. Metformin exposure induces antiproliferative effects in cancer stem cell-enriched cultures, isolated from three individual WHO grade IV human glioblastomas. These effects phenocopy metformin-mediated inhibition of a chloride current specifically dependent on CLIC1 functional activity. CLIC1 ion channel is preferentially active during the G1-S transition via transient membrane insertion. Metformin inhibition of CLIC1 activity induces G1 arrest of glioblastoma stem cells. This effect was time-dependent, and prolonged treatments caused antiproliferative effects also for low, clinically significant, metformin concentrations. Furthermore, substitution of Arg29 in the putative CLIC1 pore region impairs metformin modulation of channel activity. The lack of drugs affecting cancer stem cell viability is the main cause of therapy failure and tumor relapse. We identified CLIC1 not only as a modulator of cell cycle progression in human glioblastoma stem cells but also as the main target of metformin's antiproliferative activity, paving the way for novel and needed pharmacological approaches to glioblastoma treatment. PMID:25361004

Metformin repositioning as antitumoral agent: selective antiproliferative effects in human glioblastoma stem cells, via inhibition of CLIC1-mediated ion current.

PubMed

Gritti, Marta; Würth, Roberto; Angelini, Marina; Barbieri, Federica; Peretti, Marta; Pizzi, Erika; Pattarozzi, Alessandra; Carra, Elisa; Sirito, Rodolfo; Daga, Antonio; Curmi, Paul M G; Mazzanti, Michele; Florio, Tullio

2014-11-30

Epidemiological and preclinical studies propose that metformin, a first-line drug for type-2 diabetes, exerts direct antitumor activity. Although several clinical trials are ongoing, the molecular mechanisms of this effect are unknown. Here we show that chloride intracellular channel-1 (CLIC1) is a direct target of metformin in human glioblastoma cells. Metformin exposure induces antiproliferative effects in cancer stem cell-enriched cultures, isolated from three individual WHO grade IV human glioblastomas. These effects phenocopy metformin-mediated inhibition of a chloride current specifically dependent on CLIC1 functional activity. CLIC1 ion channel is preferentially active during the G1-S transition via transient membrane insertion. Metformin inhibition of CLIC1 activity induces G1 arrest of glioblastoma stem cells. This effect was time-dependent, and prolonged treatments caused antiproliferative effects also for low, clinically significant, metformin concentrations. Furthermore, substitution of Arg29 in the putative CLIC1 pore region impairs metformin modulation of channel activity. The lack of drugs affecting cancer stem cell viability is the main cause of therapy failure and tumor relapse. We identified CLIC1 not only as a modulator of cell cycle progression in human glioblastoma stem cells but also as the main target of metformin's antiproliferative activity, paving the way for novel and needed pharmacological approaches to glioblastoma treatment.

Human osteopontin splicing isoforms: known roles, potential clinical applications and activated signaling pathways.

PubMed

Gimba, E R; Tilli, T M

2013-04-30

Human osteopontin is subject to alternative splicing, which generates three isoforms, termed OPNa, OPNb and OPNc. These variants show specific expression and roles in different cell contexts. We present an overview of current knowledge of the expression profile of human OPN splicing isoforms (OPN-SIs), their tissue-specific roles, and the pathways mediating their functional properties in different pathophysiological conditions. We also describe their putative application as biomarkers, and their potential use as therapeutic targets by using antibodies, oligonucleotides or siRNA molecules. This synthesis provides new clues for a better understanding of human OPN splice variants, their roles in normal and pathological conditions, and their possible clinical applications. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Prevention and Treatment of ER-Negative Breast Cancer

DTIC Science & Technology

2005-10-01

human breast epithelial cell lines that express several levels of P13 kinase and AKT activity. These lines will be characterized with respect to...cancer. (4)Defined a putative role for psoriasin in breast tumor progression. (5) Progress in the analysis of the role of NFkappaB signaling in ER...press.. 9 PREVENTION AND TREATMENT OF ER-NEGATIVE BREAST CANCERPrincipal Investigator: Brown, Mvles A. 4) IGF-1 Receptor and the Akt protein kinase Akt

HaploReg v4: systematic mining of putative causal variants, cell types, regulators and target genes for human complex traits and disease.

PubMed

Ward, Lucas D; Kellis, Manolis

2016-01-04

More than 90% of common variants associated with complex traits do not affect proteins directly, but instead the circuits that control gene expression. This has increased the urgency of understanding the regulatory genome as a key component for translating genetic results into mechanistic insights and ultimately therapeutics. To address this challenge, we developed HaploReg (http://compbio.mit.edu/HaploReg) to aid the functional dissection of genome-wide association study (GWAS) results, the prediction of putative causal variants in haplotype blocks, the prediction of likely cell types of action, and the prediction of candidate target genes by systematic mining of comparative, epigenomic and regulatory annotations. Since first launching the website in 2011, we have greatly expanded HaploReg, increasing the number of chromatin state maps to 127 reference epigenomes from ENCODE 2012 and Roadmap Epigenomics, incorporating regulator binding data, expanding regulatory motif disruption annotations, and integrating expression quantitative trait locus (eQTL) variants and their tissue-specific target genes from GTEx, Geuvadis, and other recent studies. We present these updates as HaploReg v4, and illustrate a use case of HaploReg for attention deficit hyperactivity disorder (ADHD)-associated SNPs with putative brain regulatory mechanisms. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

Differential expression of conserved and novel microRNAs during tail regeneration in the lizard Anolis carolinensis.

PubMed

Hutchins, Elizabeth D; Eckalbar, Walter L; Wolter, Justin M; Mangone, Marco; Kusumi, Kenro

2016-05-05

Lizards are evolutionarily the most closely related vertebrates to humans that can lose and regrow an entire appendage. Regeneration in lizards involves differential expression of hundreds of genes that regulate wound healing, musculoskeletal development, hormonal response, and embryonic morphogenesis. While microRNAs are able to regulate large groups of genes, their role in lizard regeneration has not been investigated. MicroRNA sequencing of green anole lizard (Anolis carolinensis) regenerating tail and associated tissues revealed 350 putative novel and 196 known microRNA precursors. Eleven microRNAs were differentially expressed between the regenerating tail tip and base during maximum outgrowth (25 days post autotomy), including miR-133a, miR-133b, and miR-206, which have been reported to regulate regeneration and stem cell proliferation in other model systems. Three putative novel differentially expressed microRNAs were identified in the regenerating tail tip. Differentially expressed microRNAs were identified in the regenerating lizard tail, including known regulators of stem cell proliferation. The identification of 3 putative novel microRNAs suggests that regulatory networks, either conserved in vertebrates and previously uncharacterized or specific to lizards, are involved in regeneration. These findings suggest that differential regulation of microRNAs may play a role in coordinating the timing and expression of hundreds of genes involved in regeneration.

Molecular cloning of an inducible serine esterase gene from human cytotoxic lymphocytes.

PubMed Central

Trapani, J A; Klein, J L; White, P C; Dupont, B

1988-01-01

A cDNA clone encoding a human serine esterase gene was isolated from a library constructed from poly(A)+ RNA of allogeneically stimulated, interleukin 2-expanded peripheral blood mononuclear cells. The clone, designated HSE26.1, represents a full-length copy of a 0.9-kilobase mRNA present in human cytotoxic cells but absent from a wide variety of noncytotoxic cell lines. Clone HSE26.1 contains an 892-base-pair sequence, including a single 741-base-pair open reading frame encoding a putative 247-residue polypeptide. The first 20 amino acids of the polypeptide form a leader sequence. The mature protein is predicted to have an unglycosylated Mr of approximately equal to 26,000 and contains a single potential site for N-linked glycosylation. The nucleotide and predicted amino acid sequences of clone HSE26.1 are homologous with all murine and human serine esterases cloned thus far but are most similar to mouse granzyme B (70% nucleotide and 68% amino acid identity). HSE26.1 protein is expressed weakly in unstimulated peripheral blood mononuclear cells but is strongly induced within 6-hr incubation in medium containing phytohemagglutinin. The data suggest that the protein encoded by HSE26.1 plays a role in cell-mediated cytotoxicity. Images PMID:3261871

Season of conception in rural gambia affects DNA methylation at putative human metastable epialleles.

PubMed

Waterland, Robert A; Kellermayer, Richard; Laritsky, Eleonora; Rayco-Solon, Pura; Harris, R Alan; Travisano, Michael; Zhang, Wenjuan; Torskaya, Maria S; Zhang, Jiexin; Shen, Lanlan; Manary, Mark J; Prentice, Andrew M

2010-12-23

Throughout most of the mammalian genome, genetically regulated developmental programming establishes diverse yet predictable epigenetic states across differentiated cells and tissues. At metastable epialleles (MEs), conversely, epigenotype is established stochastically in the early embryo then maintained in differentiated lineages, resulting in dramatic and systemic interindividual variation in epigenetic regulation. In the mouse, maternal nutrition affects this process, with permanent phenotypic consequences for the offspring. MEs have not previously been identified in humans. Here, using an innovative 2-tissue parallel epigenomic screen, we identified putative MEs in the human genome. In autopsy samples, we showed that DNA methylation at these loci is highly correlated across tissues representing all 3 embryonic germ layer lineages. Monozygotic twin pairs exhibited substantial discordance in DNA methylation at these loci, suggesting that their epigenetic state is established stochastically. We then tested for persistent epigenetic effects of periconceptional nutrition in rural Gambians, who experience dramatic seasonal fluctuations in nutritional status. DNA methylation at MEs was elevated in individuals conceived during the nutritionally challenged rainy season, providing the first evidence of a permanent, systemic effect of periconceptional environment on human epigenotype. At MEs, epigenetic regulation in internal organs and tissues varies among individuals and can be deduced from peripheral blood DNA. MEs should therefore facilitate an improved understanding of the role of interindividual epigenetic variation in human disease.

Recombinant Human Parvovirus B19 Vectors: Erythroid Cell-Specific Delivery and Expression of Transduced Genes

PubMed Central

Ponnazhagan, Selvarangan; Weigel, Kirsten A.; Raikwar, Sudhanshu P.; Mukherjee, Pinku; Yoder, Mervin C.; Srivastava, Arun

1998-01-01

A novel packaging strategy combining the salient features of two human parvoviruses, namely the pathogenic parvovirus B19 and the nonpathogenic adeno-associated virus type 2 (AAV), was developed to achieve erythroid cell-specific delivery as well as expression of the transduced gene. The development of such a chimeric vector system was accomplished by packaging heterologous DNA sequences cloned within the inverted terminal repeats of AAV and subsequently packaging the DNA inside the capsid structure of B19 virus. Recombinant B19 virus particles were assembled, as evidenced by electron microscopy as well as DNA slot blot analyses. The hybrid vector failed to transduce nonerythroid human cells, such as 293 cells, as expected. However, MB-02 cells, a human megakaryocytic leukemia cell line which can be infected by B19 virus following erythroid differentiation with erythropoietin (N. C. Munshi, S. Z. Zhou, M. J. Woody, D. A. Morgan, and A. Srivastava, J. Virol. 67:562–566, 1993) but lacks the putative receptor for AAV (S. Ponnazhagan, X.-S. Wang, M. J. Woody, F. Luo, L. Y. Kang, M. L. Nallari, N. C. Munshi, S. Z. Zhou, and A. Srivastava, J. Gen. Virol. 77:1111–1122, 1996), were readily transduced by this vector. The hybrid vector was also found to specifically target the erythroid population in primary human bone marrow cells as well as more immature hematopoietic progenitor cells following erythroid differentiation, as evidenced by selective expression of the transduced gene in these target cells. Preincubation with anticapsid antibodies against B19 virus, but not anticapsid antibodies against AAV, inhibited transduction of primary human erythroid cells. The efficiency of transduction of primary human erythroid cells by the recombinant B19 virus vector was significantly higher than that by the recombinant AAV vector. Further development of the AAV-B19 virus hybrid vector system should prove beneficial in gene therapy protocols aimed at the correction of inherited and acquired human diseases affecting cells of erythroid lineage. PMID:9573295

Recent progress on normal and malignant pancreatic stem/progenitor cell research: therapeutic implications for the treatment of type 1 or 2 diabetes mellitus and aggressive pancreatic cancer

PubMed Central

Mimeault, M; Batra, S K

2010-01-01

Recent progress on pancreatic stem/progenitor cell research has revealed that the putative multipotent pancreatic stem/progenitor cells and/or more committed beta cell precursors may persist in the pancreatic gland in adult life. The presence of immature pancreatic cells with stem cell-like properties offers the possibility of stimulating their in vivo expansion and differentiation or to use their ex vivo expanded progenies for beta cell replacement-based therapies for type 1 or 2 diabetes mellitus in humans. In addition, the transplantation of either insulin-producing beta cells derived from embryonic, fetal and other tissue-resident adult stem/progenitor cells or genetically modified adult stem/progenitor cells may also constitute alternative promising therapies for treating diabetic patients. The genetic and/or epigenetic alterations in putative pancreatic adult stem/progenitor cells and/or their early progenies may, however, contribute to their acquisition of a dysfunctional behaviour as well as their malignant transformation into pancreatic cancer stem/progenitor cells. More particularly, the activation of distinct tumorigenic signalling cascades, including the hedgehog, epidermal growth factor–epidermal growth factor receptor (EGF–EGFR) system, wingless ligand (Wnt)/β-catenin and/or stromal cell-derived factor-1 (SDF-1)–CXC chemokine receptor 4 (CXCR4) pathways may play a major role in the sustained growth, survival, metastasis and/or drug resistance of pancreatic cancer stem/progenitor cells and their further differentiated progenies. The combination of drugs that target the oncogenic elements in pancreatic cancer stem/progenitor cells and their microenvironment, with the conventional chemotherapeutic regimens, could represent promising therapeutic strategies. These novel targeted therapies should lead to the development of more effective treatments of locally advanced and metastatic pancreatic cancers, which remain incurable with current therapies. PMID:18791122

Genetic modification of adeno-associated viral vector type 2 capsid enhances gene transfer efficiency in polarized human airway epithelial cells.

PubMed

White, April F; Mazur, Marina; Sorscher, Eric J; Zinn, Kurt R; Ponnazhagan, Selvarangan

2008-12-01

Cystic fibrosis (CF) is a common genetic disease characterized by defects in the expression of the CF transmembrane conductance regulator (CFTR) gene. Gene therapy offers better hope for the treatment of CF. Adeno-associated viral (AAV) vectors are capable of stable expression with low immunogenicity. Despite their potential in CF gene therapy, gene transfer efficiency by AAV is limited because of pathophysiological barriers in these patients. Although a few AAV serotypes have shown better transduction compared with the AAV2-based vectors, gene transfer efficiency in human airway epithelium has still not reached therapeutic levels. To engineer better AAV vectors for enhanced gene delivery in human airway epithelium, we developed and characterized mutant AAV vectors by genetic capsid modification, modeling the well-characterized AAV2 serotype. We genetically incorporated putative high-affinity peptide ligands to human airway epithelium on the GH loop region of AAV2 capsid protein. Six independent mutant AAV were constructed, containing peptide ligands previously reported to bind with high affinity for known and unknown receptors on human airway epithelial cells. The vectors were tested on nonairway cells and nonpolarized and polarized human airway epithelial cells for enhanced infectivity. One of the mutant vectors, with the peptide sequence THALWHT, not only showed the highest transduction in undifferentiated human airway epithelial cells but also indicated significant transduction in polarized cells. Interestingly, this modified vector was also able to infect cells independently of the heparan sulfate proteoglycan receptor. Incorporation of this ligand on other AAV serotypes, which have shown improved gene transfer efficiency in the human airway epithelium, may enhance the application of AAV vectors in CF gene therapy.

Stem cells--clinical application and perspectives.

PubMed

Brehm, Michael; Zeus, Tobias; Strauer, Bodo Eckehard

2002-11-01

Augmentation of myocardial performance in experimental models of therapeutic infarction and heart failure has been achieved by transplantation of exogenous cells into damaged myocardium. The quest for suitable donor cells has prompted research into the use of both embryonic stem cells and adult somatic stem cells. Recently, there has been a growing body of evidence that multipotent somatic stem cells in adult bone marrow exhibit tremendous functional plasticity and can reprogram in a new environmental tissue niche to give rise to cell lineages specific for new organ site. This phenomenon has made huge impact on myocardial biology, while multipotent adult bone marrow hematopoeitic stem cells and mesechymal stem cells can repopulate infarcted rodent myocardium and differentiate into both cardiomyocytes and new blood vessels. These data, coupled with the identification of a putative primitive cardiac stem cell population in the adult human heart, may open the way for novel therapeutic modalities for enhancing myocardial performance and treating heart failure.

Differential splicing of human androgen receptor pre-mRNA in X-linked reifenstein syndrome, because of a deletion involving a putative branch site

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

Ris-Stalpers, C.; Verleun-Mooijman, M.C.T.; Blaeij, T.J.P. de

1994-04-01

The analysis of the androgen receptor (AR) gene, mRNA, and protein in a subject with X-linked Reifenstein syndrome (partial androgen insensitivity) is reported. The presence of two mature AR transcripts in genital skin fibroblasts of the patient is established, and, by reverse transcriptase-PCR and RNase transcription analysis, the wild-type transcript and a transcript in which exon 3 sequences are absent without disruption of the translational reading frame are identified. Sequencing and hybridization analysis show a deletion of >6 kb in intron 2 of the human AR gene, starting 18 bp upstream of exon 3. The deletion includes the putative branch-pointmore » sequence (BPS) but not the acceptor splice site on the intron 2/exon 3 boundary. The deletion of the putative intron 2 BPS results in 90% inhibition of wild-type splicing. The mutant transcript encodes an AR protein lacking the second zinc finger of the DNA-binding domain. Western/immunoblotting analysis is used to show that the mutant AR protein is expressed in genital skin fibroblasts of the patient. The residual 10% wild-type transcript can be the result of the use of a cryptic BPS located 63 bp upstream of the intron 2/exon 3 boundary of the mutant AR gene. The mutated AR protein has no transcription-activating potential and does not influence the transactivating properties of the wild-type AR, as tested in cotransfection studies. It is concluded that the partial androgen-insensitivity syndrome of this patient is the consequence of the limited amount of wild-type AR protein expressed in androgen target cells, resulting from the deletion of the intron 2 putative BPS. 42 refs., 6 figs., 1 tab.« less

Effect of human patient plasma ex vivo treatment on gene expression and progenitor cell activation of primary human liver cells in multi-compartment 3D perfusion bioreactors for extra-corporeal liver support.

PubMed

Schmelzer, Eva; Mutig, Kerim; Schrade, Petra; Bachmann, Sebastian; Gerlach, Jörg C; Zeilinger, Katrin

2009-07-01

Cultivation of primary human liver cells in innovative 3D perfusion multi-compartment capillary membrane bioreactors using decentralized mass exchange and integral oxygenation provides in vitro conditions close to the physiologic environment in vivo. While a few scale-up bioreactors were used clinically, inoculated liver progenitors in these bioreactors were not investigated. Therefore, we characterized regenerative processes and expression patterns of auto- and paracrine mediators involved in liver regeneration in bioreactors after patient treatment. Primary human liver cells containing parenchymal and non-parenchymal cells co-cultivated in bioreactors were used for clinical extra-corporeal liver support to bridge to liver transplantation. 3D tissue re-structuring in bioreactors was studied; expression of proteins and genes related to regenerative processes and hepatic progenitors was analyzed. Formation of multiple bile ductular networks and colonies of putative progenitors were observed within parenchymal cell aggregates. HGF was detected in scattered cells located close to vascular-like structures, expression of HGFA and c-Met was assigned to biliary cells and hepatocytes. Increased expression of genes associated to hepatic progenitors was detected following clinical application. The results confirm auto- and paracrine interactions between co-cultured cells in the bioreactor. The 3D bioreactor provides a valuable tool to study mechanisms of progenitor activation and hepatic regeneration ex vivo under patient plasma treatment. (c) 2009 Wiley Periodicals, Inc.

Characterization of human DNGR-1+ BDCA3+ leukocytes as putative equivalents of mouse CD8α+ dendritic cells

PubMed Central

Poulin, Lionel Franz; Salio, Mariolina; Griessinger, Emmanuel; Anjos-Afonso, Fernando; Craciun, Ligia; Chen, Ji-Li; Keller, Anna M.; Joffre, Olivier; Zelenay, Santiago; Nye, Emma; Le Moine, Alain; Faure, Florence; Donckier, Vincent; Sancho, David; Cerundolo, Vincenzo; Bonnet, Dominique

2010-01-01

In mouse, a subset of dendritic cells (DCs) known as CD8α+ DCs has emerged as an important player in the regulation of T cell responses and a promising target in vaccination strategies. However, translation into clinical protocols has been hampered by the failure to identify CD8α+ DCs in humans. Here, we characterize a population of human DCs that expresses DNGR-1 (CLEC9A) and high levels of BDCA3 and resembles mouse CD8α+ DCs in phenotype and function. We describe the presence of such cells in the spleens of humans and humanized mice and report on a protocol to generate them in vitro. Like mouse CD8α+ DCs, human DNGR-1+ BDCA3hi DCs express Necl2, CD207, BATF3, IRF8, and TLR3, but not CD11b, IRF4, TLR7, or (unlike CD8α+ DCs) TLR9. DNGR-1+ BDCA3hi DCs respond to poly I:C and agonists of TLR8, but not of TLR7, and produce interleukin (IL)-12 when given innate and T cell–derived signals. Notably, DNGR-1+ BDCA3+ DCs from in vitro cultures efficiently internalize material from dead cells and can cross-present exogenous antigens to CD8+ T cells upon treatment with poly I:C. The characterization of human DNGR-1+ BDCA3hi DCs and the ability to grow them in vitro opens the door for exploiting this subset in immunotherapy. PMID:20479117

Comparison of porcine endogenous retroviruses infectious potential in supernatants of producer cells and in cocultures.

PubMed

Costa, Michael Rodrigues; Fischer, Nicole; Gulich, Barbara; Tönjes, Ralf R

2014-01-01

Porcine endogenous retroviruses (PERV) pose a zoonotic risk potential in pig-to-human xenotransplantation given that PERV capacity to infect different human cell lines in vitro has been clearly shown in the past. However, PERV infectious potential for human peripheral blood mononuclear cells (huPBMC) has been also demonstrated, albeit with controversial results. As productive PERV infection of huPBMC involves immune suppression that may attract opportunistic pathogens as shown for other retroviruses, it is crucial to ascertain unequivocally huPBMC susceptibility for PERV. To address this question, we first investigated in vitro infectivity of PERV for huPBMC using supernatants containing highly infectious PERV-A/C. Second, huPBMC were cocultivated with PERV-A/C producer cells to come a step closer to the in vivo situation of xenotransplantation. In addition, cocultivation of huPBMC with porcine PBMC (poPBMC) isolated from German landrace pigs was performed to distinguish PERV replication competence when they were constitutively produced by immortalized cells or by primary poPBMC. Supernatants containing recombinant highly infectious PERV-A/C were used to infect PHA-activated huPBMC in the presence or absence of polybrene. Next, PERV-producing cell lines such as human 293/5° and primary mitogenically activated poPBMC of three German landrace pigs were cocultivated with huPBMC as well as with susceptible human and porcine cell lines as controls. PERV infection was monitored by using three test approaches. The presence of provirus DNA in putatively infected cells was detected via sensitive nested PCR. Viral expression was determined by screening for the activity of gammaretroviral reverse transcriptase (RT) in cell-free supernatants of infected cells. Virus release was monitored by counting the number of packaged RNA particles in supernatants via PERV-specific quantitative one-step real-time reverse transcriptase PCR. Porcine endogenous retroviruses-A/C in supernatants of human producer 293/5° cells was not able to infect huPBMC. Neither RT activity nor PERV copies were detected. Even provirus could not be detected displaying the inability of PERV-A/C to induce a productive infection in huPBMC. In cocultivation experiments only non-productive infection of huPBMC with PERV derived from 293/5° cell line and from PHA-activated poPBMC was observed by detection of provirus DNA in infected cells. Recombinant PERV-A/C in supernatants of producer cells failed to infect huPBMC, whereas coculture experiments with producer cell lines lead to non-productive infection of huPBMC. PERV in supernatants seem to have not sufficient infectious potential for huPBMC. However, extensive PERV exposure to huPBMC via cocultivation enabled at least virus cell entry as provirus was detected by nested PCR. Furthermore, results presented support previous data showing German landrace pigs as low producers with negligible infectious potential due to the absence of replication-competent PERV in the genome. The low PERV expression profile and the lack of significant replication competence of German landrace pigs raise hope for considering these animals as putative donor animals in future pig-to-human xenotransplantation. Nonetheless, data imply that PERV still represent a virological risk in the course of xenotransplantation, as the presence of PERV provirus in host cells may lead to a provirus integration resulting in insertional mutagenesis and chromosomal rearrangements. © 2014 John Wiley & Sons A/S.

Coming of Age: CD96 Emerges as Modulator of Immune Responses.

PubMed

Georgiev, Hristo; Ravens, Inga; Papadogianni, Georgia; Bernhardt, Günter

2018-01-01

CD96 represents a type I transmembrane glycoprotein belonging to the immunoglobulin superfamily. CD96 is expressed mainly by cells of hematopoietic origin, in particular on T and NK cells. Upon interaction with CD155 present on target cells, CD96 was found to inhibit mouse NK cells, and absence of this interaction either by blocking with antibody or knockout of CD96 showed profound beneficial effects in containment of tumors and metastatic spread in murine model systems. However, our knowledge regarding CD96 functions remains fragmentary. In this review, we will discuss structural features of CD96 and their putative impact on function as well as some unresolved issues such as a potential activation that may be conferred by human but not mouse CD96. This is of importance for translation into human cancer therapy. We will also address CD96 activities in the context of the immune regulatory network that consists of CD155, CD96, CD226, and TIGIT.

Decursin inhibited proliferation and angiogenesis of endothelial cells to suppress diabetic retinopathy via VEGFR2.

PubMed

Yang, Ying; Yang, Ke; Li, Yiping; Li, Xianli; Sun, Qiangming; Meng, Hua; Zeng, Ying; Hu, Yong; Zhang, Ying

2013-09-25

Diabetes induces pathologic proliferation and angiogenesis in the retina that leads to catastrophic loss of vision. Decursin is a novel therapeutic that targets the vascular endothelial growth factor (VEGF) receptor (VEGFR) with putative anti-proliferative and anti-angiogenic activities. Thereby we utilized human retinal microvascular endothelial cells (HRMEC) and human umbilical vein endothelial cells (HUVEC) under conditions of excess glucose to explore dose-dependent responses of decursin on markers of migration, angiogenesis, and proliferation. Decursin dose-dependently inhibited tube formation, VEGFR-2 expression, along with relative metabolic activity and 5-bromo-2'-deoxy-uridine (BrdU) activity in both cell lines. We then correlated our findings to the streptozotocin-induced rat model of diabetes. Following three months of decursin treatment VEGFR-2 expression was significantly inhibited. Our data would suggest that decursin may be a potent anti-angiogenic and anti-proliferative agent targeting the VEGFR-2 signaling pathway, which significantly inhibits diabetic retinal neovascularization. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

The use of bone marrow stromal cells (bone marrow-derived multipotent mesenchymal stromal cells) for alveolar bone tissue engineering: basic science to clinical translation.

PubMed

Kagami, Hideaki; Agata, Hideki; Inoue, Minoru; Asahina, Izumi; Tojo, Arinobu; Yamashita, Naohide; Imai, Kohzoh

2014-06-01

Bone tissue engineering is a promising field of regenerative medicine in which cultured cells, scaffolds, and osteogenic inductive signals are used to regenerate bone. Human bone marrow stromal cells (BMSCs) are the most commonly used cell source for bone tissue engineering. Although it is known that cell culture and induction protocols significantly affect the in vivo bone forming ability of BMSCs, the responsible factors of clinical outcome are poorly understood. The results from recent studies using human BMSCs have shown that factors such as passage number and length of osteogenic induction significantly affect ectopic bone formation, although such differences hardly affected the alkaline phosphatase activity or gene expression of osteogenic markers. Application of basic fibroblast growth factor helped to maintain the in vivo osteogenic ability of BMSCs. Importantly, responsiveness of those factors should be tested under clinical circumstances to improve the bone tissue engineering further. In this review, clinical application of bone tissue engineering was reviewed with putative underlying mechanisms.

Liquid Chromatography Mass Spectrometry Analysis and Cytotoxicity of Asparagus adscendens Roots against Human Cancer Cell Lines.

PubMed

Khan, Kashif Maqbool; Nahar, Lutfun; Mannan, Abdul; Arfan, Muhammad; Khan, Ghazanfar Ali; Al-Groshi, Afaf; Evans, Andrew; Dempster, Nicola M; Ismail, Fyaz M D; Sarker, Satyajit D

2018-01-01

Asparagus adscendens Roxb. (Asparagaceae), is native to the Himalayas. This plant has been used in the prevention and effective treatment of various forms of cancers. This paper reports, for the first time, on the cytotoxicity of the methanol (MeOH) extract of the roots of A. adscendens and its solid-phase extraction (SPE) fractions against four human carcinoma cell lines and LC-ESI-QTOF-MS analysis of the SPE fractions. Finely powdered roots of A. adscendens were macerated in methanol and extracted through SPE using gradient solvent system (water: methanol) proceeded for analysis on LC-ESI-QTOF-MS and cytotoxicity against four human carcinoma cell lines: breast (MCF7), liver (HEPG2), lung (A549), and urinary bladder (EJ138), using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide assay. The MeOH extract and four SPE fractions exhibited cytotoxicity against all cell lines with the IC 50 values ranging from 6 to 79 μg/mL. As observed in other Asparagus species, the presence of saponins and sapogenins in the SPE fractions was evident in the liquid chromatography-mass spectrometry data. It is reasonable to assume that the cytotoxicity of the MeOH extract of the roots of A. adscendens and its SPE fractions, at least partly, due to the presence of saponins and their aglycones. This suggests that A. adscendens could be exploited as a potential source of cytotoxic compounds with putative anticancer potential. The MeOH extract and all solid-phase extraction (SPE) fractions exhibited various levels of cytotoxicity against all cell lines with the IC 50 values ranging from 6 to 79 μg/mLThe presence of saponins and sapogenins in the SPE fractions was evident in the Liquid chromatography-mass spectrometry dataDue to the presence of saponins and their aglycones, suggest that A. adscendens could be exploited as a potential source of cytotoxic compounds with putative anticancer potential. Abbreviation used: SPE: Solid-phase extraction, MCF7: Breast cancer cell line, HEPG2: Liver cancer cell line, A549: Lung liver cancer cell line, EJ138: Urinary bladder cancer cell line, MTT: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide, LC-MS: Liquid chromatography-mass spectrometry.

Chronic inorganic arsenic exposure in vitro induces a cancer cell phenotype in human peripheral lung epithelial cells

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

Person, Rachel J.; Olive Ngalame, Ntube N.; Makia, Ngome L.

Inorganic arsenic is a human lung carcinogen. We studied the ability of chronic inorganic arsenic (2 μM; as sodium arsenite) exposure to induce a cancer phenotype in the immortalized, non-tumorigenic human lung peripheral epithelial cell line, HPL-1D. After 38 weeks of continuous arsenic exposure, secreted matrix metalloproteinase-2 (MMP2) activity increased to over 200% of control, levels linked to arsenic-induced cancer phenotypes in other cell lines. The invasive capacity of these chronic arsenic-treated lung epithelial (CATLE) cells increased to 320% of control and colony formation increased to 280% of control. CATLE cells showed enhanced proliferation in serum-free media indicative of autonomousmore » growth. Compared to control cells, CATLE cells showed reduced protein expression of the tumor suppressor gene PTEN (decreased to 26% of control) and the putative tumor suppressor gene SLC38A3 (14% of control). Morphological evidence of epithelial-to-mesenchymal transition (EMT) occurred in CATLE cells together with appropriate changes in expression of the EMT markers vimentin (VIM; increased to 300% of control) and e-cadherin (CDH1; decreased to 16% of control). EMT is common in carcinogenic transformation of epithelial cells. CATLE cells showed increased KRAS (291%), ERK1/2 (274%), phosphorylated ERK (p-ERK; 152%), and phosphorylated AKT1 (p-AKT1; 170%) protein expression. Increased transcript expression of metallothioneins, MT1A and MT2A and the stress response genes HMOX1 (690%) and HIF1A (247%) occurred in CATLE cells possibly in adaptation to chronic arsenic exposure. Thus, arsenic induced multiple cancer cell characteristics in human peripheral lung epithelial cells. This model may be useful to assess mechanisms of arsenic-induced lung cancer. - Highlights: • Chronic arsenic exposure transforms a human peripheral lung epithelia cell line. • Cells acquire characteristics in common with human lung adenocarcinoma cells. • These transformed cells provide a valuable model for arsenic-induced lung cancer.« less

Next-generation sequencing reveals low-dose effects of cationic dendrimers in primary human bronchial epithelial cells.

PubMed

Feliu, Neus; Kohonen, Pekka; Ji, Jie; Zhang, Yuning; Karlsson, Hanna L; Palmberg, Lena; Nyström, Andreas; Fadeel, Bengt

2015-01-27

Gene expression profiling has developed rapidly in recent years with the advent of deep sequencing technologies such as RNA sequencing (RNA Seq) and could be harnessed to predict and define mechanisms of toxicity of chemicals and nanomaterials. However, the full potential of these technologies in (nano)toxicology is yet to be realized. Here, we show that systems biology approaches can uncover mechanisms underlying cellular responses to nanomaterials. Using RNA Seq and computational approaches, we found that cationic poly(amidoamine) dendrimers (PAMAM-NH2) are capable of triggering down-regulation of cell-cycle-related genes in primary human bronchial epithelial cells at doses that do not elicit acute cytotoxicity, as demonstrated using conventional cell viability assays, while gene transcription was not affected by neutral PAMAM-OH dendrimers. The PAMAMs were internalized in an active manner by lung cells and localized mainly in lysosomes; amine-terminated dendrimers were internalized more efficiently when compared to the hydroxyl-terminated dendrimers. Upstream regulator analysis implicated NF-κB as a putative transcriptional regulator, and subsequent cell-based assays confirmed that PAMAM-NH2 caused NF-κB-dependent cell cycle arrest. However, PAMAM-NH2 did not affect cell cycle progression in the human A549 adenocarcinoma cell line. These results demonstrate the feasibility of applying systems biology approaches to predict cellular responses to nanomaterials and highlight the importance of using relevant (primary) cell models.

Effects of chronic low dose rotenone treatment on human microglial cells

PubMed Central

2009-01-01

Background Exposure to toxins/chemicals is considered to be a significant risk factor in the pathogenesis of Parkinson's disease (PD); one putative chemical is the naturally occurring herbicide rotenone that is now used widely in establishing PD models. We, and others, have shown that chronic low dose rotenone treatment induces excessive accumulation of Reactive Oxygen Species (ROS), inclusion body formation and apoptosis in dopaminergic neurons of animal and human origin. Some studies have also suggested that microglia enhance the rotenone induced neurotoxicity. While the effects of rotenone on neurons are well established, there is little or no information available on the effect of rotenone on microglial cells, and especially cells of human origin. The aim of the present study was to investigate the effects of chronic low dose rotenone treatment on human microglial CHME-5 cells. Methods We have shown previously that rotenone induced inclusion body formation in human dopaminergic SH-SY5Y cells and therefore used these cells as a control for inclusion body formation in this study. SH-SY5Y and CHME-5 cells were treated with 5 nM rotenone for four weeks. At the end of week 4, both cell types were analysed for the presence of inclusion bodies, superoxide dismutases and cell activation (only in CHME-5 cells) using Haematoxylin and Eosin staining, immunocytochemical and western blotting methods. Levels of active caspases and ROS (both extra and intra cellular) were measured using biochemical methods. Conclusion The results suggest that chronic low dose rotenone treatment activates human microglia (cell line) in a manner similar to microglia of animal origin as shown by others. However human microglia release excessive amounts of ROS extracellularly, do not show excessive amounts of intracellular ROS and active caspases and most importantly do not show any protein aggregation or inclusion body formation. Human microglia appear to be resistant to rotenone (chronic, low dose) induced damage. PMID:20042120

Putative SF2 helicases of the early-branching eukaryote Giardia lamblia are involved in antigenic variation and parasite differentiation into cysts

PubMed Central

2012-01-01

Background Regulation of surface antigenic variation in Giardia lamblia is controlled post-transcriptionally by an RNA-interference (RNAi) pathway that includes a Dicer-like bidentate RNase III (gDicer). This enzyme, however, lacks the RNA helicase domain present in Dicer enzymes from higher eukaryotes. The participation of several RNA helicases in practically all organisms in which RNAi was studied suggests that RNA helicases are potentially involved in antigenic variation, as well as during Giardia differentiation into cysts. Results An extensive in silico analysis of the Giardia genome identified 32 putative Super Family 2 RNA helicases that contain almost all the conserved RNA helicase motifs. Phylogenetic studies and sequence analysis separated them into 22 DEAD-box, 6 DEAH-box and 4 Ski2p-box RNA helicases, some of which are homologs of well-characterized helicases from higher organisms. No Giardia putative helicase was found to have significant homology to the RNA helicase domain of Dicer enzymes. Additionally a series of up- and down-regulated putative RNA helicases were found during encystation and antigenic variation by qPCR experiments. Finally, we were able to recognize 14 additional putative helicases from three different families (RecQ family, Swi2/Snf2 and Rad3 family) that could be considered DNA helicases. Conclusions This is the first comprehensive analysis of the Super Family 2 helicases from the human intestinal parasite G. lamblia. The relative and variable expression of particular RNA helicases during both antigenic variation and encystation agrees with the proposed participation of these enzymes during both adaptive processes. The putatives RNA and DNA helicases identified in this early-branching eukaryote provide initial information regarding the biological role of these enzymes in cell adaptation and differentiation. PMID:23190735

Identification of Putative Cardiovascular System Developmental Toxicants using a Classification Model based on Signaling Pathway-Adverse Outcome Pathways

EPA Science Inventory

An important challenge for an integrative approach to developmental systems toxicology is associating putative molecular initiating events (MIEs), cell signaling pathways, cell function and modeled fetal exposure kinetics. We have developed a chemical classification model based o...

Cryo-electron microscopy structure of human peroxiredoxin-3 filament reveals the assembly of a putative chaperone.

PubMed

Radjainia, Mazdak; Venugopal, Hariprasad; Desfosses, Ambroise; Phillips, Amy J; Yewdall, N Amy; Hampton, Mark B; Gerrard, Juliet A; Mitra, Alok K

2015-05-05

Peroxiredoxins (Prxs) are a ubiquitous class of thiol-dependent peroxidases that play an important role in the protection and response of cells to oxidative stress. The catalytic unit of typical 2-Cys Prxs are homodimers, which can self-associate to form complex assemblies that are hypothesized to have signaling and chaperone activity. Mitochondrial Prx3 forms dodecameric toroids, which can further stack to form filaments, the so-called high-molecular-weight (HMW) form that has putative holdase activity. We used single-particle analysis and helical processing of electron cryomicroscopy images of human Prx3 filaments induced by low pH to generate a ∼7-Å resolution 3D structure of the HMW form, the first such structure for a 2-Cys Prx. The pseudo-atomic model reveals interactions that promote the stacking of the toroids and shows that unlike previously reported data, the structure can accommodate a partially folded C terminus. The HMW filament lumen displays hydrophobic patches, which we hypothesize bestow holdase activity. Copyright © 2015 Elsevier Ltd. All rights reserved.

Putative Bronchopulmonary Flagellated Protozoa in Immunosuppressed Patients

PubMed Central

Kilimcioglu, Ali Ahmet; Havlucu, Yavuz; Çelik, Pınar; Özbilgin, Ahmet

2014-01-01

Flagellated protozoa that cause bronchopulmonary symptoms in humans are commonly neglected. These protozoal forms which were presumed to be “flagellated protozoa” have been previously identified in immunosuppressed patients in a number of studies, but have not been certainly classified so far. Since no human cases of bronchopulmonary flagellated protozoa were reported from Turkey, we aimed to investigate these putative protozoa in immunosuppressed patients who are particularly at risk of infectious diseases. Bronchoalveolar lavage fluid samples of 110 immunosuppressed adult patients who were admitted to the Department of Chest Diseases, Hafsa Sultan Hospital of Celal Bayar University, Manisa, Turkey, were examined in terms of parasites by light microscopy. Flagellated protozoal forms were detected in nine (8.2%) of 110 cases. Metronidazole (500 mg b.i.d. for 30 days) was given to all positive cases and a second bronchoscopy was performed at the end of the treatment, which revealed no parasites. In conclusion, immunosuppressed patients with bronchopulmonary symptoms should attentively be examined with regard to flagellated protozoa which can easily be misidentified as epithelial cells. PMID:24804259

Distinct p53 genomic binding patterns in normal and cancer-derived human cells

PubMed Central

McCorkle, Sean R; McCombie, WR; Dunn, John J

2011-01-01

Here, we report genome-wide analysis of the tumor suppressor p53 binding sites in normal human cells. 743 high-confidence ChIP-seq peaks representing putative genomic binding sites were identified in normal IMR90 fibroblasts using a reference chromatin sample. More than 40% were located within 2 kb of a transcription start site (TSS), a distribution similar to that documented for individually studied, functional p53 binding sites and, to date, not observed by previous p53 genome-wide studies. Nearly half of the high-confidence binding sites in the IMR90 cells reside in CpG islands in marked contrast to sites reported in cancer-derived cells. The distinct genomic features of the IMR90 binding sites do not reflect a distinct preference for specific sequences, since the de novo developed p53 motif based on our study is similar to those reported by genome-wide studies of cancer cells. More likely, the different chromatin landscape in normal, compared with cancer-derived cells, influences p53 binding via modulating availability of the sites. We compared the IMR90 ChIP-seq peaks to the recently published IMR90 methylome1 and demonstrated that they are enriched at hypomethylated DNA. Our study represents the first genome-wide, de novo mapping of p53 binding sites in normal human cells and reveals that p53 binding sites reside in distinct genomic landscapes in normal and cancer-derived human cells. PMID:22127205

Dihydroartemisinin as a Putative STAT3 Inhibitor, Suppresses the Growth of Head and Neck Squamous Cell Carcinoma by Targeting Jak2/STAT3 Signaling

PubMed Central

Jia, Lifeng; Song, Qi; Zhou, Chenyang; Li, Xiaoming; Pi, Lihong; Ma, Xiuru; Li, Hui; Lu, Xiuying; Shen, Yupeng

2016-01-01

Developing drugs that can effectively block STAT3 activation may serve as one of the most promising strategy for cancer treatment. Currently, there is no putative STAT3 inhibitor that can be safely and effectively used in clinic. In the present study, we investigated the potential of dihydroartemisinin (DHA) as a putative STAT3 inhibitor and its antitumor activities in head and neck squamous cell carcinoma (HNSCC). The inhibitory effects of DHA on STAT3 activation along with its underlying mechanisms were studied in HNSCC cells. The antitumor effects of DHA against HNSCC cells were explored both in vitro and in vivo. An investigation on cooperative effects of DHA with cisplatin in killing HNSCC cells was also implemented. DHA exhibited remarkable and specific inhibitory effects on STAT3 activation via selectively blocking Jak2/STAT3 signaling. Besides, DHA significantly inhibited HNSCC growth both in vitro and in vivo possibly through induction of apoptosis and attenuation of cell migration. DHA also synergized with cisplatin in tumor inhibition in HNSCC cells. Our findings demonstrate that DHA is a putative STAT3 inhibitor that may represent a new and effective drug for cancer treatment and therapeutic sensitization in HNSCC patients. PMID:26784960

Mucin (MUC1) Expression and Function in Prostate Cancer Cells

DTIC Science & Technology

2004-03-01

Biophysical Research Communications 293 (2002) 1183-1190 1189 site, and is a feature of MUC4 metabolism [36]. [12] S. Zotter, P.C. Hageman, A. Lossnitzer...W.J. Mooi, J. Hilgers, Although the cleavage site sequence in MUC4 differs Tissue and tumor distribution of human polymorphic epithelial from that of...family of putative secreted (2001) 715-720. and membrane-associated MUC4 mucins, Eur. J. Biochem. 267 [261 M. Boshell, E-N. Lalani, L. Pemberton, J

Telocytes and putative stem cells in the lungs: electron microscopy, electron tomography and laser scanning microscopy.

PubMed

Popescu, Laurentiu M; Gherghiceanu, Mihaela; Suciu, Laura C; Manole, Catalin G; Hinescu, Mihail E

2011-09-01

This study describes a novel type of interstitial (stromal) cell - telocytes (TCs) - in the human and mouse respiratory tree (terminal and respiratory bronchioles, as well as alveolar ducts). TCs have recently been described in pleura, epicardium, myocardium, endocardium, intestine, uterus, pancreas, mammary gland, etc. (see www.telocytes.com ). TCs are cells with specific prolongations called telopodes (Tp), frequently two to three per cell. Tp are very long prolongations (tens up to hundreds of μm) built of alternating thin segments known as podomers (≤ 200 nm, below the resolving power of light microscope) and dilated segments called podoms, which accommodate mitochondria, rough endoplasmic reticulum and caveolae. Tp ramify dichotomously, making a 3-dimensional network with complex homo- and heterocellular junctions. Confocal microscopy reveals that TCs are c-kit- and CD34-positive. Tp release shed vesicles or exosomes, sending macromolecular signals to neighboring cells and eventually modifying their transcriptional activity. At bronchoalveolar junctions, TCs have been observed in close association with putative stem cells (SCs) in the subepithelial stroma. SCs are recognized by their ultrastructure and Sca-1 positivity. Tp surround SCs, forming complex TC-SC niches (TC-SCNs). Electron tomography allows the identification of bridging nanostructures, which connect Tp with SCs. In conclusion, this study shows the presence of TCs in lungs and identifies a TC-SC tandem in subepithelial niches of the bronchiolar tree. In TC-SCNs, the synergy of TCs and SCs may be based on nanocontacts and shed vesicles.

SUZ12 is a novel putative oncogene promoting tumorigenesis in head and neck squamous cell carcinoma.

PubMed

Wu, Yaping; Hu, Huijun; Zhang, Wei; Li, Zhongwu; Diao, Pengfei; Wang, Dongmiao; Zhang, Wei; Wang, Yanling; Yang, Jianrong; Cheng, Jie

2018-04-18

The suppressor of zest 12 (SUZ12), one of the core polycomb repressive complex 2 (PRC2) components, has increasingly appreciated as a key mediator during human tumorigenesis. However, its expression pattern and oncogenic roles in head and neck squamous cell carcinoma (HNSCC) remain largely unexplored yet. Here, we sought to determine its expression pattern, clinicopathological significance and biological roles in HNSCC. Through data mining and interrogation from multiple publicly available databases, our bioinformatics analyses revealed that SUZ12 mRNA was significantly overexpressed in multiple HNSCC patient cohorts. Moreover, SUZ12 protein was markedly up-regulated in primary HNSCC samples from our patient cohort as assessed by immunohistochemical staining and its overexpression significantly associated with cervical node metastasis and reduced overall and disease-free survival. In the 4-nitroquinoline 1-oxide (4NQO)-induced HNSCC mouse model, increased SUZ12 immunostaining was observed along with disease progression from epithelial hyperplasia to squamous cell carcinoma in tongue. Furthermore, shRNA-mediated SUZ12 knock-down significantly inhibited cell proliferation, migration and invasion in HNSCC cells, and resulted in compromised tumour growth in vivo. Collectively, our data reveal that SUZ12 might serve as a putative oncogene by promoting cell proliferation, migration and invasion, and also a novel biomarker with diagnostic and prognostic significance for HNSCC. © 2018 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

Stable Toll-Like Receptor 10 Knockdown in THP-1 Cells Reduces TLR-Ligand-Induced Proinflammatory Cytokine Expression.

PubMed

Le, Hai Van; Kim, Jae Young

2016-06-01

Toll-like receptor 10 (TLR10) is the only orphan receptor whose natural ligand and function are unknown among the 10 human TLRs. In this study, to test whether TLR10 recognizes some known TLR ligands, we established a stable TLR10 knockdown human monocytic cell line THP-1 using TLR10 short hairpin RNA lentiviral particle and puromycin selection. Among 60 TLR10 knockdown clones that were derived from each single transduced cell, six clones were randomly selected, and then one of those clones, named E7, was chosen for the functional study. E7 exhibited approximately 50% inhibition of TLR10 mRNA and protein expression. Of all the TLRs, only the expression of TLR10 changed significantly in this cell line. Additionally, phorbol 12-myristate 13-acetate-induced macrophage differentiation of TLR10 knockdown cells was not affected in the knockdown cells. When exposed to TLR ligands, such as synthetic diacylated lipoprotein (FSL-1), lipopolysaccharide (LPS), and flagellin, significant induction of proinflammatory cytokine gene expression including Interleukin-8 (IL-8), Interleukin-1 beta (IL-1β), Tumor necrosis factor-alpha (TNF-α) and Chemokine (C-C Motif) Ligand 20 (CCL20) expression, was found in the control THP-1 cells, whereas the TLR10 knockdown cells exhibited a significant reduction in the expression of IL-8, IL-1β, and CCL20. TNF-α was the only cytokine for which the expression did not decrease in the TLR10 knockdown cells from that measured in the control cells. Analysis of putative binding sites for transcription factors using a binding-site-prediction program revealed that the TNF-α promoter does not have putative binding sites for AP-1 or c-Jun, comprising a major transcription factor along with NF-κB for TLR signaling. Our results suggest that TLR10 is involved in the recognition of FSL-1, LPS, and flagellin and TLR-ligand-induced expression of TNF-α does not depend on TLR10.

Prioritizing and modelling of putative drug target proteins of Candida albicans by systems biology approach.

PubMed

Ismail, Tariq; Fatima, Nighat; Muhammad, Syed Aun; Zaidi, Syed Saoud; Rehman, Nisar; Hussain, Izhar; Tariq, Najam Us Sahr; Amirzada, Imran; Mannan, Abdul

2018-01-01

Candida albicans (Candida albicans) is one of the major sources of nosocomial infections in humans which may prove fatal in 30% of cases. The hospital acquired infection is very difficult to treat affectively due to the presence of drug resistant pathogenic strains, therefore there is a need to find alternative drug targets to cure this infection. In silico and computational level frame work was used to prioritize and establish antifungal drug targets of Candida albicans. The identification of putative drug targets was based on acquiring 5090 completely annotated genes of Candida albicans from available databases which were categorized into essential and non-essential genes. The result indicated that 9% of proteins were essential and could become potential candidates for intervention which might result in pathogen eradication. We studied cluster of orthologs and the subtractive genomic analysis of these essential proteins against human genome was made as a reference to minimize the side effects. It was seen that 14% of Candida albicans proteins were evolutionary related to the human proteins while 86% are non-human homologs. In the next step of compatible drug target selections, the non-human homologs were sequentially compared to the human microbiome data to minimize the potential effects against gut flora which accumulated to 38% of the essential genome. The sub-cellular localization of these candidate proteins in fungal cellular systems indicated that 80% of them are cytoplasmic, 10% are mitochondrial and the remaining 10% are associated with the cell wall. The role of these non-human and non-gut flora putative target proteins in Candida albicans biological pathways was studied. Due to their integrated and critical role in Candida albicans replication cycle, four proteins were selected for molecular modeling. For drug designing and development, four high quality and reliable protein models with more than 70% sequence identity were constructed. These proteins are used for the docking studies of the known and new ligands (unpublished data). Our study will be an effective framework for drug target identifications of pathogenic microbial strains and development of new therapies against the infections they cause.

Unravelling the mystery of stem/progenitor cells in human breast milk.

PubMed

Fan, Yiping; Chong, Yap Seng; Choolani, Mahesh A; Cregan, Mark D; Chan, Jerry K Y

2010-12-28

Mammary stem cells have been extensively studied as a system to delineate the pathogenesis and treatment of breast cancer. However, research on mammary stem cells requires tissue biopsies which limit the quantity of samples available. We have previously identified putative mammary stem cells in human breast milk, and here, we further characterised the cellular component of human breast milk. We identified markers associated with haemopoietic, mesenchymal and neuro-epithelial lineages in the cellular component of human breast milk. We found 2.6 ± 0.8% (mean ± SEM) and 0.7 ± 0.2% of the whole cell population (WCP) were found to be CD133+ and CD34+ respectively, 27.8 ± 9.1% of the WCP to be positive for Stro-1 through flow-cytometry. Expressions of neuro-ectodermal stem cell markers such as nestin and cytokeratin 5 were found through reverse-transcription polymerase chain reaction (RT-PCR), and in 4.17 ± 0.2% and 0.9 ± 0.2% of the WCP on flow-cytometry. We also established the presence of a side-population (SP) (1.8 ± 0.4% of WCP) as well as CD133+ cells (1.7 ± 0.5% of the WCP). Characterisation of the sorted SP and non-SP, CD133+ and CD133- cells carried out showed enrichment of CD326 (EPCAM) in the SP cells (50.6 ± 8.6 vs 18.1 ± 6.0, P-value  = 0.02). However, culture in a wide range of in vitro conditions revealed the atypical behaviour of stem/progenitor cells in human breast milk; in that if they are present, they do not respond to established culture protocols of stem/progenitor cells. The identification of primitive cell types within human breast milk may provide a non-invasive source of relevant mammary cells for a wide-range of applications; even the possibility of banking one's own stem cell for every breastfeeding woman.

Unravelling the Mystery of Stem/Progenitor Cells in Human Breast Milk

PubMed Central

Fan, Yiping; Chong, Yap Seng; Choolani, Mahesh A.; Cregan, Mark D.; Chan, Jerry K. Y.

2010-01-01

Background Mammary stem cells have been extensively studied as a system to delineate the pathogenesis and treatment of breast cancer. However, research on mammary stem cells requires tissue biopsies which limit the quantity of samples available. We have previously identified putative mammary stem cells in human breast milk, and here, we further characterised the cellular component of human breast milk. Methodology/Principal Findings We identified markers associated with haemopoietic, mesenchymal and neuro-epithelial lineages in the cellular component of human breast milk. We found 2.6±0.8% (mean±SEM) and 0.7±0.2% of the whole cell population (WCP) were found to be CD133+ and CD34+ respectively, 27.8±9.1% of the WCP to be positive for Stro-1 through flow-cytometry. Expressions of neuro-ectodermal stem cell markers such as nestin and cytokeratin 5 were found through reverse-transcription polymerase chain reaction (RT-PCR), and in 4.17±0.2% and 0.9±0.2% of the WCP on flow-cytometry. We also established the presence of a side-population (SP) (1.8±0.4% of WCP) as well as CD133+ cells (1.7±0.5% of the WCP). Characterisation of the sorted SP and non-SP, CD133+ and CD133- cells carried out showed enrichment of CD326 (EPCAM) in the SP cells (50.6±8.6 vs 18.1±6.0, P-value  = 0.02). However, culture in a wide range of in vitro conditions revealed the atypical behaviour of stem/progenitor cells in human breast milk; in that if they are present, they do not respond to established culture protocols of stem/progenitor cells. Conclusions/Significance The identification of primitive cell types within human breast milk may provide a non-invasive source of relevant mammary cells for a wide-range of applications; even the possibility of banking one's own stem cell for every breastfeeding woman. PMID:21203434

Upregulation of SMAD4 by MZF1 inhibits migration of human gastric cancer cells.

PubMed

Lee, Jin-Hee; Kim, Sung-Su; Lee, Hun Seok; Hong, Sungyoul; Rajasekaran, Nirmal; Wang, Li-Hui; Choi, Joon-Seok; Shin, Young Kee

2017-01-01

SMAD4 is a tumor suppressor that is frequently inactivated in many types of cancer. The role of abnormal expression of SMAD4 has been reported in developmental processes and the progression of various human cancers. The expression level of SMAD4 has been related to the survival rate in gastric cancer patients. However, the molecular mechanism underlying transcriptional regulation of SMAD4 remains largely unknown. In the present study, we characterized the promoter region of SMAD4 and identified myeloid zinc finger 1 (MZF1), as a putative transcription factor. MZF1 directly bound to a core region of the SMAD4 promoter and stimulated transcriptional activity. We also found that the expression of MZF1 influences the migration ability of gastric adenocarcinoma cells. Collectively, our results showed that MZF1 has a role in cellular migration of gastric cancer cells via promoting an increase in intracellular SMAD4 levels. This study might provide new evidence for the molecular basis of the tumor suppressive effect of the MZF1-SMAD4 axis, a new therapeutic target in advanced human gastric cancer.

In vitro antiprogestational/antiglucocorticoid activity and progestin and glucocorticoid receptor binding of the putative metabolites and synthetic derivatives of CDB-2914, CDB-4124, and mifepristone.

PubMed

Attardi, Barbara J; Burgenson, Janet; Hild, Sheri A; Reel, Jerry R

2004-03-01

In determining the biological profiles of various antiprogestins, it is important to assess the hormonal and antihormonal activity, selectivity, and potency of their proximal metabolites. The early metabolism of mifepristone is characterized by rapid demethylation and hydroxylation. Similar initial metabolic pathways have been proposed for CDB-2914 (CDB: Contraceptive Development Branch of NICHD) and CDB-4124, and their putative metabolites have been synthesized. We have examined the functional activities and potencies, in various cell-based assays, and relative binding affinities (RBAs) for progesterone receptors (PR) and glucocorticoid receptors (GR) of the putative mono- and didemethylated metabolites of CDB-2914, CDB-4124, and mifepristone and of the 17alpha-hydroxy and aromatic A-ring derivatives of CDB-2914 and CDB-4124. The binding affinities of the monodemethylated metabolites for rabbit uterine PR and human PR-A and PR-B were similar to those of the parent compounds. Monodemethylated mifepristone bound to rabbit thymic GR with higher affinity than monodemethylated CDB-2914 or CDB-4124. T47D-CO cells were used to assess inhibition of R5020-stimulated endogenous alkaline phosphatase activity and transactivation of the PRE(2)-thymidine kinase (tk)-luciferase (LUC) reporter plasmid in transient transfections. The antiprogestational potency was as follows: mifepristone/CDB-2914/CDB-4124/monodemethylated metabolites (IC(50)'s approximately 10(-9)M) > aromatic A-ring derivatives (IC(50)'s approximately 10(-8)M) > didemethylated/17alpha-hydroxy derivatives (IC(50)'s approximately 10(-7)M). Antiglucocorticoid activity was determined by inhibition of dexamethasone-stimulated transcriptional activity in HepG2 cells. The mono- and didemethylated metabolites of CDB-2914 and CDB-4124 had less antiglucocorticoid activity (IC(50)'s approximately 10(-6)M) than monodemethylated mifepristone (IC(50) approximately 10(-8)M) or the other test compounds. At 10(-6)M in transcription assays, none of these compounds showed progestin agonist activity, whereas mifepristone and its monodemethylated metabolite manifested slight glucocorticoid agonist activity. The reduced antiglucocorticoid activity of monodemethylated CDB-2914 and CDB-4124 was confirmed in vivo by the thymus involution assay in adrenalectomized male rats. The aromatic A-ring derivatives-stimulated transcription of an estrogen-responsive reporter plasmid in MCF-7 and T47D-CO human breast cancer cells but were much less potent than estradiol. Taken together, these data suggest that the proximal metabolites of mifepristone, CDB-2914, and CDB-4124 contribute significantly to the antiprogestational activity of the parent compounds in vivo. Furthermore, the reduced antiglucocorticoid activity of CDB-2914 and CDB-4124 compared to mifepristone in vivo may be due in part to decreased activity of their putative proximal metabolites.

Growth of human breast tissues from patient cells in 3D hydrogel scaffolds.

PubMed

Sokol, Ethan S; Miller, Daniel H; Breggia, Anne; Spencer, Kevin C; Arendt, Lisa M; Gupta, Piyush B

2016-03-01

Three-dimensional (3D) cultures have proven invaluable for expanding human tissues for basic research and clinical applications. In both contexts, 3D cultures are most useful when they (1) support the outgrowth of tissues from primary human cells that have not been immortalized through extensive culture or viral infection and (2) include defined, physiologically relevant components. Here we describe a 3D culture system with both of these properties that stimulates the outgrowth of morphologically complex and hormone-responsive mammary tissues from primary human breast epithelial cells. Primary human breast epithelial cells isolated from patient reduction mammoplasty tissues were seeded into 3D hydrogels. The hydrogel scaffolds were composed of extracellular proteins and carbohydrates present in human breast tissue and were cultured in serum-free medium containing only defined components. The physical properties of these hydrogels were determined using atomic force microscopy. Tissue growth was monitored over time using bright-field and fluorescence microscopy, and maturation was assessed using morphological metrics and by immunostaining for markers of stem cells and differentiated cell types. The hydrogel tissues were also studied by fabricating physical models from confocal images using a 3D printer. When seeded into these 3D hydrogels, primary human breast epithelial cells rapidly self-organized in the absence of stromal cells and within 2 weeks expanded to form mature mammary tissues. The mature tissues contained luminal, basal, and stem cells in the correct topological orientation and also exhibited the complex ductal and lobular morphologies observed in the human breast. The expanded tissues became hollow when treated with estrogen and progesterone, and with the further addition of prolactin produced lipid droplets, indicating that they were responding to hormones. Ductal branching was initiated by clusters of cells expressing putative mammary stem cell markers, which subsequently localized to the leading edges of the tissue outgrowths. Ductal elongation was preceded by leader cells that protruded from the tips of ducts and engaged with the extracellular matrix. These 3D hydrogel scaffolds support the growth of complex mammary tissues from primary patient-derived cells. We anticipate that this culture system will empower future studies of human mammary gland development and biology.

Comparison of RAW264.7, human whole blood and PBMC assays to screen for immunomodulators.

PubMed

Elisia, Ingrid; Pae, Han Bee; Lam, Vivian; Cederberg, Rachel; Hofs, Elyse; Krystal, Gerald

2018-01-01

The RAW264.7 mouse macrophage cell line is used extensively to carry out in vitro screens for immunomodulators. Compounds that are effective at reducing the expression of pro-inflammatory cytokines or nitric oxide (NO) from lipopolysaccharide (LPS)-stimulated RAW264.7 cells are often considered candidate anti-inflammatory agents for humans. There is, however, very little data on the reliability of this screen to identify bona fide human immunomodulators. We compared the efficacy of 37 purported immunomodulators to modulate LPS or E. coli-induced inflammatory responses in RAW264.7 cell, whole human blood and human peripheral blood mononuclear cell (PBMC) assays. Interestingly, there was no significant correlation (R=0.315) between the responses obtained with RAW264.7 cells and the whole blood assay (WBA), suggesting that compounds demonstrating efficacy in RAW264.7 cells may be ineffective in humans, and, more importantly, compounds that are effective in humans may be missed with a RAW264.7 screen. Interestingly, there was also no significant correlation between the WBA and human PBMCs when the latter were cultured with 10% FCS, but a moderate correlation was seen when the PBMCs were cultured with 25% autologous plasma. The presence of plasma thus contributes to the overall inflammatory response observed in the WBA. We then asked if RAW264.7 cells, given that they are mouse macrophage-like cells, respond in a manner similar to primary murine derived macrophages. Intriguingly, there was no significant correlation (R=0.012) with the 37 putative immunomodulators, pointing to distinct inflammatory response mechanisms in the two model systems. We conclude that the use of a WBA to confirm potential immunomodulators obtained from high throughput screening with RAW264.7 cells is advisable and that future screens be carried out using a WBA. Copyright © 2017 Elsevier B.V. All rights reserved.

A Putative Multiple-Demand System in the Macaque Brain.

PubMed

Mitchell, Daniel J; Bell, Andrew H; Buckley, Mark J; Mitchell, Anna S; Sallet, Jerome; Duncan, John

2016-08-17

In humans, cognitively demanding tasks of many types recruit common frontoparietal brain areas. Pervasive activation of this "multiple-demand" (MD) network suggests a core function in supporting goal-oriented behavior. A similar network might therefore be predicted in nonhuman primates that readily perform similar tasks after training. However, an MD network in nonhuman primates has not been described. Single-cell recordings from macaque frontal and parietal cortex show some similar properties to human MD fMRI responses (e.g., adaptive coding of task-relevant information). Invasive recordings, however, come from limited prespecified locations, so they do not delineate a macaque homolog of the MD system and their positioning could benefit from knowledge of where MD foci lie. Challenges of scanning behaving animals mean that few macaque fMRI studies specifically contrast levels of cognitive demand, so we sought to identify a macaque counterpart to the human MD system using fMRI connectivity in 35 rhesus macaques. Putative macaque MD regions, mapped from frontoparietal MD regions defined in humans, were found to be functionally connected under anesthesia. To further refine these regions, an iterative process was used to maximize their connectivity cross-validated across animals. Finally, whole-brain connectivity analyses identified voxels that were robustly connected to MD regions, revealing seven clusters across frontoparietal and insular cortex comparable to human MD regions and one unexpected cluster in the lateral fissure. The proposed macaque MD regions can be used to guide future electrophysiological investigation of MD neural coding and in task-based fMRI to test predictions of similar functional properties to human MD cortex. In humans, a frontoparietal "multiple-demand" (MD) brain network is recruited during a wide range of cognitively demanding tasks. Because this suggests a fundamental function, one might expect a similar network to exist in nonhuman primates, but this remains controversial. Here, we sought to identify a macaque counterpart to the human MD system using fMRI connectivity. Putative macaque MD regions were functionally connected under anesthesia and were further refined by iterative optimization. The result is a network including lateral frontal, dorsomedial frontal, and insular and inferior parietal regions closely similar to the human counterpart. The proposed macaque MD regions can be useful in guiding electrophysiological recordings or in task-based fMRI to test predictions of similar functional properties to human MD cortex. Copyright © 2016 Mitchell et al.

Systematic MicroRNA Analysis Identifies ATP6V0C as an Essential Host Factor for Human Cytomegalovirus Replication

PubMed Central

Pavelin, Jon; Reynolds, Natalie; Chiweshe, Stephen; Wu, Guanming; Tiribassi, Rebecca; Grey, Finn

2013-01-01

Recent advances in microRNA target identification have greatly increased the number of putative targets of viral microRNAs. However, it is still unclear whether all targets identified are biologically relevant. Here, we use a combined approach of RISC immunoprecipitation and focused siRNA screening to identify targets of HCMV encoded human cytomegalovirus that play an important role in the biology of the virus. Using both a laboratory and clinical strain of human cytomegalovirus, we identify over 200 putative targets of human cytomegalovirus microRNAs following infection of fibroblast cells. By comparing RISC-IP profiles of miRNA knockout viruses, we have resolved specific interactions between human cytomegalovirus miRNAs and the top candidate target transcripts and validated regulation by western blot analysis and luciferase assay. Crucially we demonstrate that miRNA target genes play important roles in the biology of human cytomegalovirus as siRNA knockdown results in marked effects on virus replication. The most striking phenotype followed knockdown of the top target ATP6V0C, which is required for endosomal acidification. siRNA knockdown of ATP6V0C resulted in almost complete loss of infectious virus production, suggesting that an HCMV microRNA targets a crucial cellular factor required for virus replication. This study greatly increases the number of identified targets of human cytomegalovirus microRNAs and demonstrates the effective use of combined miRNA target identification and focused siRNA screening for identifying novel host virus interactions. PMID:24385903

Spatiotemporal dynamics of neocortical excitation and inhibition during human sleep.

PubMed

Peyrache, Adrien; Dehghani, Nima; Eskandar, Emad N; Madsen, Joseph R; Anderson, William S; Donoghue, Jacob A; Hochberg, Leigh R; Halgren, Eric; Cash, Sydney S; Destexhe, Alain

2012-01-31

Intracranial recording is an important diagnostic method routinely used in a number of neurological monitoring scenarios. In recent years, advancements in such recordings have been extended to include unit activity of an ensemble of neurons. However, a detailed functional characterization of excitatory and inhibitory cells has not been attempted in human neocortex, particularly during the sleep state. Here, we report that such feature discrimination is possible from high-density recordings in the neocortex by using 2D multielectrode arrays. Successful separation of regular-spiking neurons (or bursting cells) from fast-spiking cells resulted in well-defined clusters that each showed unique intrinsic firing properties. The high density of the array, which allowed recording from a large number of cells (up to 90), helped us to identify apparent monosynaptic connections, confirming the excitatory and inhibitory nature of regular-spiking and fast-spiking cells, thus categorized as putative pyramidal cells and interneurons, respectively. Finally, we investigated the dynamics of correlations within each class. A marked exponential decay with distance was observed in the case of excitatory but not for inhibitory cells. Although the amplitude of that decline depended on the timescale at which the correlations were computed, the spatial constant did not. Furthermore, this spatial constant is compatible with the typical size of human columnar organization. These findings provide a detailed characterization of neuronal activity, functional connectivity at the microcircuit level, and the interplay of excitation and inhibition in the human neocortex.

Protein profile of basal prostate epithelial progenitor cells--stage-specific embryonal antigen 4 expressing cells have enhanced regenerative potential in vivo.

PubMed

Höfner, Thomas; Klein, Corinna; Eisen, Christian; Rigo-Watermeier, Teresa; Haferkamp, Axel; Sprick, Martin R

2016-04-01

The long-term propagation of basal prostate progenitor cells ex vivo has been very difficult in the past. The development of novel methods to expand prostate progenitor cells in vitro allows determining their cell surface phenotype in greater detail. Mouse (Lin(-)Sca-1(+) CD49f(+) Trop2(high)-phenotype) and human (Lin(-) CD49f(+) TROP2(high)) basal prostate progenitor cells were expanded in vitro. Human and mouse cells were screened using 242 anti-human or 176 antimouse monoclonal antibodies recognizing the cell surface protein profile. Quantitative expression was evaluated at the single-cell level using flow cytometry. Differentially expressed cell surface proteins were evaluated in conjunction with the known CD49f(+)/TROP2(high) phenotype of basal prostate progenitor cells and characterized by in vivo sandwich-transplantation experiments using nude mice. The phenotype of basal prostate progenitor cells was determined as CD9(+)/CD24(+)/CD29(+)/CD44(+)/CD47(+)/CD49f(+)/CD104(+)/CD147(+)/CD326(+)/Trop2(high) of mouse as well as human origin. Our analysis revealed several proteins, such as CD13, Syndecan-1 and stage-specific embryonal antigens (SSEAs), as being differentially expressed on murine and human CD49f(+) TROP2(+) basal prostate progenitor cells. Transplantation experiments suggest that CD49f(+) TROP2(high) SSEA-4(high) human prostate basal progenitor cells to be more potent to regenerate prostate tubules in vivo as compared with CD49f(+) TROP2(high) or CD49f(+) TROP2(high) SSEA-4(low) cells. Determination of the cell surface protein profile of functionally defined murine and human basal prostate progenitor cells reveals differentially expressed proteins that may change the potency and regenerative function of epithelial progenitor cells within the prostate. SSEA-4 is a candidate cell surface marker that putatively enables a more accurate identification of the basal PESC lineage. © 2016 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

Potassium recycling pathways in the human cochlea.

PubMed

Weber, P C; Cunningham, C D; Schulte, B A

2001-07-01

Potential pathways for recycling potassium (K+) used in the maintenance of inner ear electrochemical gradients have been elucidated in animal models. However, little is known about K+ transport in the human cochlea. This study was designed to characterize putative K+ recycling pathways in the human ear and to determine whether observations from animal models can be extrapolated to humans. A prospective laboratory study using an immunohistochemical approach to analyze the distribution of key ion transport mediators in the human cochlea. Human temporal bones were fixed in situ within 1 to 6 hours of death and subsequently harvested at autopsy. Decalcification was accomplished with the aid of microwaving. Immunohistochemical staining was then performed to define the presence and cell type-specific distribution of Na,K-ATPase, sodium-potassium-chloride cotransporter (NKCC), and carbonic anhydrase (CA) in the inner ear. Staining patterns visualized in the human cochlea closely paralleled those seen in other species. Anti-Na,K-ATPase stained strongly the basolateral plasma membrane of strial marginal cells and nerve endings underlying hair cells. This antibody also localized Na,K-ATPase to type II, type IV, and type V fibrocytes in the spiral ligament and in limbal fibrocytes. NKCC was present in the basolateral membrane of strial marginal cells as well as in type II, type V, and limbal fibrocytes. Immunoreactive carbonic anhydrase was present in type I and type III fibrocytes and in epithelial cells lining Reissner's membrane and the spiral prominence. The distribution of several major ion transport proteins in the human cochlea is similar but not identical to that described in various rodent models. These results support the presence of a complex system for recycling and regulating K+ homeostasis in the human cochlea, similar to that described in other mammalian species.

The origin of pre-neoplastic metaplasia in the stomach: Chief cells emerge from the Mist

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

Goldenring, James R., E-mail: jim.goldenring@vanderbilt.edu; Departments of Surgery and Cell and Developmental Biology, Epithelial Biology Center, Vanderbilt University School of Medicine, Nashville, TN; Nam, Ki Taek

2011-11-15

The digestive-enzyme secreting, gastric epithelial chief (zymogenic) cell is remarkable and underappreciated. Here, we discuss how all available evidence suggests that mature chief cells in the adult, mammalian stomach are postmitotic, slowly turning over cells that arise via a relatively long-lived progenitor, the mucous neck cell, The differentiation of chief cells from neck cells does not involve cell division, and the neck cell has its own distinct pattern of gene expression and putative physiological function. Thus, the ontogeny of the normal chief cell lineage exemplifies transdifferentiation. Furthermore, under pathophysiogical loss of acid-secreting parietal cell, the chief cell lineage can itselfmore » trasndifferentiate into a mucous cell metaplasia designated Spasmolytic Polypeptide Expressing Metaplasia (SPEM). Especially in the presence of inflammation, this metaplastic lineage can regain proliferative capacity and, in humans may also further differentiate into intestinal metaplasia. The results indicate that gastric fundic lineages display remarkable plasticity in both physiological ontogeny and pathophysiological pre-neoplastic metaplasia.« less

Expression and Characterization of a Bifidobacterium adolescentis Beta-Mannanase Carrying Mannan-Binding and Cell Association Motifs

PubMed Central

Kulcinskaja, Evelina; Rosengren, Anna; Ibrahim, Romany; Kolenová, Katarína

2013-01-01

The gene encoding β-mannanase (EC 3.2.1.78) BaMan26A from the bacterium Bifidobacterium adolescentis (living in the human gut) was cloned and the gene product characterized. The enzyme was found to be modular and to contain a putative signal peptide. It possesses a catalytic module of the glycoside hydrolase family 26, a predicted immunoglobulin-like module, and two putative carbohydrate-binding modules (CBMs) of family 23. The enzyme is likely cell attached either by the sortase mechanism (LPXTG motif) or via a C-terminal transmembrane helix. The gene was expressed in Escherichia coli without the native signal peptide or the cell anchor. Two variants were made: one containing all four modules, designated BaMan26A-101K, and one truncated before the CBMs, designated BaMan26A-53K. BaMan26A-101K, which contains the CBMs, showed an affinity to carob galactomannan having a dissociation constant of 0.34 μM (8.8 mg/liter), whereas BaMan26A-53K did not bind, showing that at least one of the putative CBMs of family 23 is mannan binding. For BaMan26A-53K, kcat was determined to be 444 s−1 and Km 21.3 g/liter using carob galactomannan as the substrate at the optimal pH of 5.3. Both of the enzyme variants hydrolyzed konjac glucomannan, as well as carob and guar gum galactomannans to a mixture of oligosaccharides. The dominant product from ivory nut mannan was found to be mannotriose. Mannobiose and mannotetraose were produced to a lesser extent, as shown by high-performance anion-exchange chromatography. Mannobiose was not hydrolyzed, and mannotriose was hydrolyzed at a significantly lower rate than the longer oligosaccharides. PMID:23064345

Metabolomics and cytotoxicity of monomethylhydrazine (MMH) and (E)-1,1,4,4-tetramethyl-2-tetrazene (TMTZ), two liquid propellants.

PubMed

Guyot, Laetitia; Machon, Christelle; Honorat, Myléne; Manship, Brigitte; Bouard, Charlotte; Vigneron, Arnaud; Puisieux, Alain; Labarthe, Emilie; Jacob, Guy; Dhenain, Anne; Guitton, Jérôme; Payen, Léa

2018-06-07

Hydrazine-based liquid propellants are routinely used for space rocket propulsion, in particular monomethylhydrazine (MMH), although such compounds are highly hazardous. For several years, great efforts were devoted to developing a less hazardous molecule. To explore the toxicological effects of an alternative compound, namely (E)-1,1,4,4-tetramethyl-2-tetrazene (TMTZ), we exposed various cellular animal and human models to this compound and to the reference compound MMH. We observed no cytotoxic effects following exposure to TMTZ in animal, as well as human models. However, although the three animal models were unaffected by MMH, exposure of the human hepatic HepaRG cell model revealed that apoptotic cytotoxic effects were only detectable in proliferative human hepatic HepaRG cells and not in differentiated cells, although major biochemical modifications were uncovered in the latter. The present findings indicate that the metabolic mechanisms of MMH toxicity is close to those described for hydrazine with numerous biochemical alterations induced by mitochondrial disruption, production of radical species, and aminotransferase inhibition. The alternative TMTZ molecule had little impact on cellular viability and proliferation of rodent and human dermic and hepatic cell models. TMTZ did not produce any metabolomic effects and appears to be a promising putative industrial alternative to MMH. Copyright © 2018. Published by Elsevier Ltd.

The effect of riboflavin-UV-A treatment on corneal limbal epithelial cells--a study on human cadaver eyes.

PubMed

Vimalin, Jeyalatha; Gupta, Nidhi; Jambulingam, Malathi; Padmanabhan, Prema; Madhavan, Hajib N

2012-09-01

To determine the effect of riboflavin-UV-A treatment on the corneal limbal epithelial cells during a corneal collagen cross-linking (CXL) procedure. Thirty freshly enucleated human cadaveric eyeballs were subjected to a CXL procedure, mimicking the clinical protocol. During the UV-A exposure, one half of the limbus (sector A) was left unprotected, whereas the other half (sector B) was covered by a metal shield. Limbal biopsies from both sectors before and after the procedure were analyzed. Each strip of tissue was divided into 3 segments, for cell count of viable cells, for cultivation on human amniotic membrane (HAM), and for stem cell and differentiated corneal epithelial cell marker studies using reverse transcriptase-polymerase chain reaction. Compared with the cell count before CXL, there was a statistically significant drop in the mean number of viable cells after CXL in sector A but not in sector B. Biopsies from both sectors before CXL and from sector B after CXL showed good growth on HAM. Biopsies from sector A after CXL showed no growth on HAM. The putative stem cell marker ABCG2 was absent in all samples and p63 was absent in 3 of 10 samples taken from sector A after CXL. All markers were present in all samples from sector B after CXL. Riboflavin-UV-A treatment can result in damage to limbal epithelial cells, particularly the stem cells. Covering the limbal region with a metal shield effectively prevents this damage.

A Preliminary Study: Human Fibroid Stro-1+/CD44+ Stem Cells Isolated From Uterine Fibroids Demonstrate Decreased DNA Repair and Genomic Integrity Compared to Adjacent Myometrial Stro-1+/CD44+ Cells.

PubMed

Prusinski Fernung, Lauren E; Al-Hendy, Ayman; Yang, Qiwei

2018-01-01

Although uterine fibroids (UFs) continue to place a major burden on female reproductive health, the mechanisms behind their origin remain undetermined. Normal myometrial stem cells may be transformed into tumor-initiating stem cells, causing UFs, due to unknown causes of somatic mutations in MED12, found in up to 85% of sporadically formed UFs. It is well established in other tumor types that defective DNA repair increases the risk of such tumorigenic somatic mutations, mechanisms not yet studied in UFs. To examine the putative cause(s) of this stem cell transformation, we analyzed DNA repair within stem cells from human UFs compared to those from adjacent myometrium to determine whether DNA repair in fibroid stem cells is compromised. Human fibroid (F) and adjacent myometrial (Myo) stem cells were isolated from fresh tissues, and gene expression relating to DNA repair was analyzed. Fibroid stem cells differentially expressed DNA repair genes related to DNA double- (DSBs) and single-strand breaks. DNA damage was measured using alkaline comet assay. Additionally, DNA DSBs were induced in these stem cells and DNA DSB repair evaluated (1) by determining changes in phosphorylation of DNA DSB-related proteins and (2) by determining differences in γ-H2AX foci formation and relative DNA repair protein RAD50 expression. Overall, F stem cells demonstrated increased DNA damage and altered DNA repair gene expression and signaling, suggesting that human F stem cells demonstrate impaired DNA repair. Compromised F stem cell DNA repair may contribute to further mutagenesis and, consequently, further growth and propagation of UF tumors.

Downregulation of missing in metastasis gene (MIM) is associated with the progression of bladder transitional carcinomas.

PubMed

Wang, Ying; Liu, Jiali; Smith, Elizabeth; Zhou, Kang; Liao, Jie; Yang, Guang-Yu; Tan, Ming; Zhan, Xi

2007-03-01

Missing in metastasis (MIM) gene encodes a putative metastasis suppressor. However, the role of MIM in tumorigenesis and metastasis has not yet been established. Western blot analysis using a MIM specific antibody demonstrated that MIM protein is present at varying levels in a variety of normal cells as well as tumor cell lines. Immunohistochemical staining of adult mouse tissues revealed abundant MIM immunoreactivity in uroepithelial cells in the bladder, neuron Purkinje cells in the cerebellum, and megakaryocytes in the bone marrow and spleen in addition. MIM immunoreactivity also was found in human normal bladder transitional epithelial cells. However, the reactivity was not seen in 69 percent of human primary transitional cell carcinoma specimens. Over 51 percent of the tumors at low grade display MIM staining similarly to the normal cells, whereas only 16.7 percent of the tumors at high-grade with poor differentiation show faint or mild staining. Furthermore, full-length MIM protein is highly expressed in SV-HUC-L an immortalized normal transitional epithelial cell line, moderately expressed in T24 and poorly expressed in J82 and TCCSUP transitional cell carcinoma cells. This finding indicates that downegulation of MIM expression may correlate with the transition of tumor cells from distinct epithelium-like morphology to less differentiated carcinomas.

Induced adult stem (iAS) cells and induced transit amplifying progenitor (iTAP) cells-a possible alternative to induced pluripotent stem (iPS) cells?

PubMed

Heng, Boon Chin; Richards, Mark; Ge, Zigang; Shu, Yimin

2010-02-01

The successful derivation of iPSC lines effectively demonstrates that it is possible to reset the 'developmental clock' of somatic cells all the way back to the initial embryonic state. Hence, it is plausible that this clock may instead be turned back half-way to a less immature developmental stage that is more directly applicable to clinical therapeutic applications or for in vitro pharmacology/toxicology screening assays. Such a suitable developmental state is postulated to be either the putative transit amplifying progenitor stage or adult stem cell stage. It is hypothetically possible to reprogram mature and terminally differentiated somatic cells back to the adult stem cell or transit amplifying progenitor stage, in a manner similar to the derivation of iPSC. It is proposed that the terminology 'Induced Adult Stem Cells' (iASC) or 'Induced Transit Amplifying Progenitor Cells' (iTAPC) be used to described such reprogrammed somatic cells. Of particular interest, is the possibility of resetting the developmental clock of mature differentiated somatic cells of the mesenchymal lineage, explanted from adipose tissue, bone marrow and cartilage. The putative adult stem cell sub-population from which these cells are derived, commonly referred to as 'mesenchymal stem cells', are highly versatile and hold much therapeutic promise in regenerative medicine, as attested to by numerous human clinical trials and animal studies. Perhaps it may be appropriate to term such reprogrammed cells as 'Induced Mesenchymal Stem Cells' (iMSC) or as 'Induced Mesenchumal Progenitor Cells' (iMPC). Given that cells from the same organ/tissue will share some commonalities in gene expression, we hypothesize that the generation of iASC or iTAPC would be more efficient as compared to iPSC generation, since a common epigenetic program must exist between the reprogrammed cells, adult stem cell or progenitor cell types and terminally differentiated cell types from the same organ/tissue.

Expression of putative pathogenicity-related genes in Xylella fastidiosa grown at low and high cell density conditions in vitro.

PubMed

Scarpari, Leandra M; Lambais, Marcio R; Silva, Denise S; Carraro, Dirce M; Carrer, Helaine

2003-05-16

Xylella fastidiosa is the causal agent of economically important plant diseases, including citrus variegated chlorosis and Pierce's disease. Hitherto, there has been no information on the molecular mechanisms controlling X. fastidiosa-plant interactions. To determine whether predicted open reading frames (ORFs) encoding putative pathogenicity-related factors were expressed by X. fastidiosa 9a5c cells grown at low (LCD) and high cell density (HCD) conditions in liquid modified PW medium, reverse Northern blot hybridization and reverse transcription-polymerase chain reaction (RT-PCR) experiments were performed. Our results indicated that ORFs XF2344, XF2369, XF1851 and XF0125, encoding putative Fur, GumC, a serine-protease and RsmA, respectively, were significantly suppressed at HCD conditions. In contrast, ORF XF1115, encoding putative RpfF, was significantly induced at HCD conditions. Expressions of ORFs XF2367, XF2362 and XF0290, encoding putative GumD, GumJ and RpfA, respectively, were detected only at HCD conditions, whereas expression of ORF XF0287, encoding putative RpfB was detected only at LCD conditions. Bioassays with an Agrobacterium traG::lacZ reporter system indicated that X. fastidiosa does not synthesize N-acyl-homoserine lactones, whereas bioassays with a diffusible signal factor (DSF)-responsive Xanthomonas campestris pv. campestris mutant indicate that X. fastidiosa synthesizes a molecule similar to DSF in modified PW medium. Our data also suggest that the synthesis of the DSF-like molecule and fastidian gum by X. fastidiosa is affected by cell density in vitro.

Nimrod, a putative phagocytosis receptor with EGF repeats in Drosophila plasmatocytes.

PubMed

Kurucz, Eva; Márkus, Róbert; Zsámboki, János; Folkl-Medzihradszky, Katalin; Darula, Zsuzsanna; Vilmos, Péter; Udvardy, Andor; Krausz, Ildikó; Lukacsovich, Tamás; Gateff, Elisabeth; Zettervall, Carl-Johan; Hultmark, Dan; Andó, István

2007-04-03

The hemocytes, the blood cells of Drosophila, participate in the humoral and cellular immune defense reactions against microbes and parasites [1-8]. The plasmatocytes, one class of hemocytes, are phagocytically active and play an important role in immunity and development by removing microorganisms as well as apoptotic cells. On the surface of circulating and sessile plasmatocytes, we have now identified a protein, Nimrod C1 (NimC1), which is involved in the phagocytosis of bacteria. Suppression of NimC1 expression in plasmatocytes inhibited the phagocytosis of Staphylococcus aureus. Conversely, overexpression of NimC1 in S2 cells stimulated the phagocytosis of both S. aureus and Escherichia coli. NimC1 is a 90-100 kDa single-pass transmembrane protein with ten characteristic EGF-like repeats (NIM repeats). The nimC1 gene is part of a cluster of ten related nimrod genes at 34E on chromosome 2, and similar clusters of nimrod-like genes are conserved in other insects such as Anopheles and Apis. The Nimrod proteins are related to other putative phagocytosis receptors such as Eater and Draper from D. melanogaster and CED-1 from C. elegans. Together, they form a superfamily that also includes proteins that are encoded in the human genome.

rse, a novel receptor-type tyrosine kinase with homology to Axl/Ufo, is expressed at high levels in the brain.

PubMed

Mark, M R; Scadden, D T; Wang, Z; Gu, Q; Goddard, A; Godowski, P J

1994-04-08

We have isolated cDNA clones that encode the human and murine forms of a novel receptor-type tyrosine kinase termed Rse. Sequence analysis indicates that human Rse contains 890 amino acids, with an extracellular region composed of two immunoglobulin-like domains followed by two fibronectin type III domains. Murine Rse contains 880 amino acids and shares 90% amino acid identity with its human counterpart. Rse is structurally similar to the receptor-type tyrosine kinase Axl/Ufo, and the two proteins have 35 and 63% sequence identity in their extracellular and intracellular domains, respectively. To study the synthesis and activation of this putative receptor-type tyrosine kinase, we constructed a version of Rse (termed gD-Rse, where gD represents glycoprotein D) that contains an NH2-terminal epitope tag. NIH3T3 cells were engineered to express gD-Rse, which could be detected at the cell surface by fluorescence-activated cell sorting. Moreover, gD-Rse was rapidly phosphorylated on tyrosine residues upon incubation of the cells with an antibody directed against the epitope tag, suggesting that rse encodes an active tyrosine kinase. In the human tissues we examined, the highest level of expression of rse mRNA was observed in the brain; rse mRNA was also detected in the premegakaryocytopoietic cell lines CMK11-5 and Dami. The gene for rse was localized to human chromosome 15.

History and update on host defense against vaginal candidiasis.

PubMed

Fidel, Paul L

2007-01-01

Vulvovaginal candidiasis (VVC), caused by Candida albicans, remains a significant problem in women of childbearing age. While cell-mediated immunity is considered the predominant host defense mechanism against mucosal candidal infections, two decades of research from animal models and clinical studies have revealed a lack of a protective role for adaptive immunity against VVC caused by putative immunoregulatory mechanisms. Moreover, natural protective mechanisms and factors associated with susceptibility to infection have remained elusive. That is until recently, when through a live challenge model in humans, it was revealed that protection against vaginitis coincides with a non-inflammatory innate presence, whereas symptomatic infection correlates with a neutrophil infiltrate in the vaginal lumen and elevated fungal burden. Thus, instead of VVC being caused by a putative deficient adaptive immune response, it is now being considered that symptomatic vaginitis is caused by an aggressive innate response.

Acute cardiovascular toxicity of sterilizers, PHMG, and PGH: severe inflammation in human cells and heart failure in zebrafish.

PubMed

Kim, Jae-Yong; Kim, Hak Hyeon; Cho, Kyung-Hyun

2013-06-01

In 2011, dozens of children and pregnant women in Korea died by exposure to sterilizer for household humidifier, such as Oxy(®) and Cefu(®). Until now, however, it remains unknown how the sterilizer affect the human health to cause the acute deaths. To find its toxicity for organ, we investigated the putative toxicity of the sterilizer in the cardiovascular system. The sterilizers, polyhexamethylene guanidine phosphate (PHMG, Cefu(®)), and oligo-[2-(2-ethoxy)-ethoxyethyl)-guanidinium-chloride (PGH, Oxy(®)) were treated to human lipoproteins, macrophages, and dermal fibroblast cells. The PGH and PHMG at normal dosages caused severe atherogenic process in human macrophages, cytotoxic effect, and aging in human dermal cell. Zebrafish embryos, which were exposed to the sterilizer, showed early death with acute inflammation and attenuated developmental speed. All zebrafish exposed to the working concentration of PHMG (final 0.3 %) and PGH (final 10 mM) died within 70 min and displayed acute increases in serum triacylglycerol level and fatty liver induction. The dead zebrafish showed severe accumulation of fibrous collagen in the bulbous artery of the heart with elevation of reactive oxygen species. In conclusion, the sterilizers showed acute toxic effect in blood circulation system, causing by severe inflammation, atherogenesis, and aging, with embryo toxicity.

MicroRNA-188 suppresses G1/S transition by targeting multiple cyclin/CDK complexes.

PubMed

Wu, Jiangbin; Lv, Qing; He, Jie; Zhang, Haoxiang; Mei, Xueshuang; Cui, Kai; Huang, Nunu; Xie, Weidong; Xu, Naihan; Zhang, Yaou

2014-10-11

Accelerated cell cycle progression is the common feature of most cancers. MiRNAs can act as oncogenes or tumor suppressors by directly modulating cell cycle machinery. It has been shown that miR-188 is upregulated in UVB-irradiated mouse skin and human nasopharyngeal carcinoma CNE cells under hypoxic stress. However, little is known about the function of miR-188 in cell proliferation and growth control. Overexpression of miR-188 inhibits cell proliferation, tumor colony formation and G1/S cell cycle transition in human nasopharyngeal carcinoma CNE cells. Using bioinformatics approach, we identify a series of genes regulating G1/S transition as putative miR-188 targets. MiR-188 inhibits both mRNA and protein expression of CCND1, CCND3, CCNE1, CCNA2, CDK4 and CDK2, suppresses Rb phosphorylation and downregulates E2F transcriptional activity. The expression level of miR-188 also inversely correlates with the expression of miR-188 targets in human nasopharyngeal carcinoma (NPC) tissues. Moreover, studies in xenograft mouse model reveal that miR-188 is capable of inhibiting tumor initiation and progression by suppressing target genes expression and Rb phosphorylation. This study demonstrates that miR-188 exerts anticancer effects, via downregulation of multiple G1/S related cyclin/CDKs and Rb/E2F signaling pathway.

Secreted Human Adipose Leptin Decreases Mitochondrial Respiration in HCT116 Colon Cancer Cells

PubMed Central

Yehuda-Shnaidman, Einav; Nimri, Lili; Tarnovscki, Tanya; Kirshtein, Boris; Rudich, Assaf; Schwartz, Betty

2013-01-01

Obesity is a key risk factor for the development of colon cancer; however, the endocrine/paracrine/metabolic networks mediating this connection are poorly understood. Here we hypothesize that obesity results in secreted products from adipose tissue that induce malignancy-related metabolic alterations in colon cancer cells. Human HCT116 colon cancer cells, were exposed to conditioned media from cultured human adipose tissue fragments of obese vs. non-obese subjects. Oxygen consumption rate (OCR, mostly mitochondrial respiration) and extracellular acidification rate (ECAR, mostly lactate production via glycolysis) were examined vis-à-vis cell viability and expression of related genes and proteins. Our results show that conditioned media from obese (vs. non-obese) subjects decreased basal (40%, p<0.05) and maximal (50%, p<0.05) OCR and gene expression of mitochondrial proteins and Bax without affecting cell viability or expression of glycolytic enzymes. Similar changes could be recapitulated by incubating cells with leptin, whereas, leptin-receptor specific antagonist inhibited the reduced OCR induced by conditioned media from obese subjects. We conclude that secreted products from the adipose tissue of obese subjects inhibit mitochondrial respiration and function in HCT116 colon cancer cells, an effect that is at least partly mediated by leptin. These results highlight a putative novel mechanism for obesity-associated risk of gastrointestinal malignancies, and suggest potential new therapeutic avenues. PMID:24073224

Engineered three-dimensional multicellular culture model to ...

EPA Pesticide Factsheets

Tissue fusion during early mammalian development requires crosstalk between multiple cell types. For example, paracrine signaling between palatal epithelial cells and palatal mesenchyme mediates the fusion of opposing palatal shelves during embryonic development. Fusion events in developmental processes including heart development, neural tube closure, and palatal fusion are dependent on epithelial-mesenchymal interactions (EMIs) and specific signaling pathways that have been elucidated largely using gene knockout mouse models. A broad analysis of literature using ToxRefDB identified 63 ToxCast chemicals associated with cleft palate in animal models. However, the influence of these and other putative teratogens on human palatal fusion has not been examined in depth due to the lack of in vitro models incorporating EMIs between human cell types. We sought to engineer the stratified mesenchymal and epithelial structure of the developing palate in vitro using spheroid culture of human Wharton’s Jelly mesenchymal stem cells (hMSC). hMSC spheroids exhibited uniform size over time (175 ± 21 µm mean diameter) that was proportional to starting cell density. Further, hMSCs in spheroid culture exhibited increased alkaline phosphatase activity and increased expression of bglap and runx2 after 7 days of culture in osteo-induction medium, which suggests that spheroid culture together with osteo-induction medium supports osteogenic differentiation. We developed a novel pro

MITOSTATIN, a putative tumor suppressor on chromosome 12q24.1, is downregulated in human bladder and breast cancer.

PubMed

Vecchione, A; Fassan, M; Anesti, V; Morrione, A; Goldoni, S; Baldassarre, G; Byrne, D; D'Arca, D; Palazzo, J P; Lloyd, J; Scorrano, L; Gomella, L G; Iozzo, R V; Baffa, R

2009-01-15

Allelic deletions on human chromosome 12q24 are frequently reported in a variety of malignant neoplasms, indicating the presence of a tumor suppressor gene(s) in this chromosomal region. However, no reasonable candidate has been identified so far. In this study, we report the cloning and functional characterization of a novel mitochondrial protein with tumor suppressor activity, henceforth designated MITOSTATIN. Human MITOSTATIN was found within a 3.2-kb transcript, which encoded a approximately 62 kDa, ubiquitously expressed protein with little homology to any known protein. We found homozygous deletions and mutations of MITOSTATIN gene in approximately 5 and approximately 11% of various cancer-derived cells and solid tumors, respectively. When transiently overexpressed, MITOSTATIN inhibited colony formation, tumor cell growth and was proapoptotic, all features shared by established tumor suppressor genes. We discovered a specific link between MITOSTATIN overexpression and downregulation of Hsp27. Conversely, MITOSTATIN knockdown cells showed an increase in cell growth and cell survival rates. Finally, MITOSTATIN expression was significantly reduced in primary bladder and breast tumors, and its reduction was associated with advanced tumor stages. Our findings support the hypothesis that MITOSTATIN has many hallmarks of a classical tumor suppressor in solid tumors and may play an important role in cancer development and progression.

Extract from the Zooxanthellate Jellyfish Cotylorhiza tuberculata Modulates Gap Junction Intercellular Communication in Human Cell Cultures

PubMed Central

Leone, Antonella; Lecci, Raffaella Marina; Durante, Miriana; Piraino, Stefano

2013-01-01

On a global scale, jellyfish populations in coastal marine ecosystems exhibit increasing trends of abundance. High-density outbreaks may directly or indirectly affect human economical and recreational activities, as well as public health. As the interest in biology of marine jellyfish grows, a number of jellyfish metabolites with healthy potential, such as anticancer or antioxidant activities, is increasingly reported. In this study, the Mediterranean “fried egg jellyfish” Cotylorhiza tuberculata (Macri, 1778) has been targeted in the search forputative valuable bioactive compounds. A medusa extract was obtained, fractionated, characterized by HPLC, GC-MS and SDS-PAGE and assayed for its biological activity on breast cancer cells (MCF-7) and human epidermal keratinocytes (HEKa). The composition of the jellyfish extract included photosynthetic pigments, valuable ω-3 and ω-6 fatty acids, and polypeptides derived either from jellyfish tissues and their algal symbionts. Extract fractions showed antioxidant activity and the ability to affect cell viability and intercellular communication mediated by gap junctions (GJIC) differentially in MCF-7and HEKa cells. A significantly higher cytotoxicity and GJIC enhancement in MCF-7 compared to HEKa cells was recorded. A putative action mechanism for the anticancer bioactivity through the modulation of GJIC has been hypothesized and its nutraceutical and pharmaceutical potential was discussed. PMID:23697954

Extract from the zooxanthellate jellyfish Cotylorhiza tuberculata modulates gap junction intercellular communication in human cell cultures.

PubMed

Leone, Antonella; Lecci, Raffaella Marina; Durante, Miriana; Piraino, Stefano

2013-05-22

On a global scale, jellyfish populations in coastal marine ecosystems exhibit increasing trends of abundance. High-density outbreaks may directly or indirectly affect human economical and recreational activities, as well as public health. As the interest in biology of marine jellyfish grows, a number of jellyfish metabolites with healthy potential, such as anticancer or antioxidant activities, is increasingly reported. In this study, the Mediterranean "fried egg jellyfish" Cotylorhiza tuberculata (Macri, 1778) has been targeted in the search forputative valuable bioactive compounds. A medusa extract was obtained, fractionated, characterized by HPLC, GC-MS and SDS-PAGE and assayed for its biological activity on breast cancer cells (MCF-7) and human epidermal keratinocytes (HEKa). The composition of the jellyfish extract included photosynthetic pigments, valuable ω-3 and ω-6 fatty acids, and polypeptides derived either from jellyfish tissues and their algal symbionts. Extract fractions showed antioxidant activity and the ability to affect cell viability and intercellular communication mediated by gap junctions (GJIC) differentially in MCF-7 and HEKa cells. A significantly higher cytotoxicity and GJIC enhancement in MCF-7 compared to HEKa cells was recorded. A putative action mechanism for the anticancer bioactivity through the modulation of GJIC has been hypothesized and its nutraceutical and pharmaceutical potential was discussed.

NCR1 Expression Identifies Canine Natural Killer Cell Subsets with Phenotypic Similarity to Human Natural Killer Cells

PubMed Central

Foltz, Jennifer A.; Somanchi, Srinivas S.; Yang, Yanwen; Aquino-Lopez, Arianexys; Bishop, Erin E.; Lee, Dean A.

2016-01-01

Canines spontaneously develop many cancers similar to humans – including osteosarcoma, leukemia, and lymphoma – offering the opportunity to study immune therapies in a genetically heterogeneous and immunocompetent environment. However, a lack of antibodies recognizing canine NK cell markers has resulted in suboptimal characterization and unknown purity of NK cell products, hindering the development of canine models of NK cell adoptive immunotherapy. To this end, we generated a novel antibody to canine NCR1 (NKp46), the putative species-wide marker of NK cells, enabling purification of NK cells for further characterization. We demonstrate that CD3−/NKp46+ cells in healthy and osteosarcoma-bearing canines have phenotypic similarity to human CD3−/NKp46+ NK cells, expressing mRNA for CD16 and the natural cytotoxicity receptors NKp30, NKp44, and NKp80. Functionally, we demonstrate with the calcein release assay that canine CD3−/NKp46+ cells kill canine tumor cell lines without prior sensitization and secrete IFN-γ, TNF-α, IL-8, IL-10, and granulocyte-macrophage colony-stimulating factor as measured by Luminex. Similar to human NK cells, CD3−/NKp46+ cells expand rapidly on feeder cells expressing 4-1BBL and membrane-bound IL-21 (median = 20,283-fold in 21 days). Furthermore, we identify a minor Null population (CD3−/CD21−/CD14−/NKp46−) with reduced cytotoxicity against osteosarcoma cells, but similar cytokine secretion as CD3−/NKp46+ cells. Null cells in canines and humans have reduced expression of NKG2D, NKp44, and CD16 compared to NKp46+ NK cells and can be induced to express NKp46 with further expansion on feeder cells. In conclusion, we have identified and characterized canine NK cells, including an NKp46− subset of canine and human NK cells, using a novel anti-canine NKp46 antibody, and report robust ex vivo expansion of canine NK cells sufficient for adoptive immunotherapy. PMID:27933061

The cytolethal distending toxin from the chancroid bacterium Haemophilus ducreyi induces cell-cycle arrest in the G2 phase.

PubMed

Cortes-Bratti, X; Chaves-Olarte, E; Lagergård, T; Thelestam, M

1999-01-01

The potent cytolethal distending toxin produced by Haemophilus ducreyi is a putative virulence factor in the pathogenesis of chancroid. We studied its action on eukaryotic cells, with the long-term goal of understanding the pathophysiology of the disease. Intoxication of cultured human epithelial-like cells, human keratinocytes, and hamster fibroblasts was irreversible, and appeared as a gradual distention of three- to fivefold the size of control cells. Organized actin assemblies appeared concomitantly with cell enlargement, promoted by a mechanism that probably does not involve small GTPases of the Rho protein family. Intoxicated cells did not proliferate. Similar to cells treated with other cytolethal distending toxins, these cells accumulated in the G2 phase of the cell cycle, demonstrating an increased level of the tyrosine phosphorylated (inactive) form of the cyclin-dependent kinase p34(cdc2). DNA synthesis was not affected until several hours after this increase, suggesting that the toxin acts directly on some kinase/phosphatase in the signaling network controlling the p34(cdc2) activity. We propose that this toxin has an important role both in the generation of chancroid ulcers and in their slow healing. The toxin may also be an interesting new tool for molecular studies of the eukaryotic cell- cycle machinery.

The cytolethal distending toxin from the chancroid bacterium Haemophilus ducreyi induces cell-cycle arrest in the G2 phase

PubMed Central

Cortes-Bratti, Ximena; Chaves-Olarte, Esteban; Lagergård, Teresa; Thelestam, Monica

1999-01-01

The potent cytolethal distending toxin produced by Haemophilus ducreyi is a putative virulence factor in the pathogenesis of chancroid. We studied its action on eukaryotic cells, with the long-term goal of understanding the pathophysiology of the disease. Intoxication of cultured human epithelial-like cells, human keratinocytes, and hamster fibroblasts was irreversible, and appeared as a gradual distention of three- to fivefold the size of control cells. Organized actin assemblies appeared concomitantly with cell enlargement, promoted by a mechanism that probably does not involve small GTPases of the Rho protein family. Intoxicated cells did not proliferate. Similar to cells treated with other cytolethal distending toxins, these cells accumulated in the G2 phase of the cell cycle, demonstrating an increased level of the tyrosine phosphorylated (inactive) form of the cyclin-dependent kinase p34cdc2. DNA synthesis was not affected until several hours after this increase, suggesting that the toxin acts directly on some kinase/phosphatase in the signaling network controlling the p34cdc2 activity. We propose that this toxin has an important role both in the generation of chancroid ulcers and in their slow healing. The toxin may also be an interesting new tool for molecular studies of the eukaryotic cell- cycle machinery. PMID:9884340

Development of a high-throughput screening system for identification of novel reagents regulating DNA damage in human dermal fibroblasts.

PubMed

Bae, Seunghee; An, In-Sook; An, Sungkwan

2015-09-01

Ultraviolet (UV) radiation is a major inducer of skin aging and accumulated exposure to UV radiation increases DNA damage in skin cells, including dermal fibroblasts. In the present study, we developed a novel DNA repair regulating material discovery (DREAM) system for the high-throughput screening and identification of putative materials regulating DNA repair in skin cells. First, we established a modified lentivirus expressing the luciferase and hypoxanthine phosphoribosyl transferase (HPRT) genes. Then, human dermal fibroblast WS-1 cells were infected with the modified lentivirus and selected with puromycin to establish cells that stably expressed luciferase and HPRT (DREAM-F cells). The first step in the DREAM protocol was a 96-well-based screening procedure, involving the analysis of cell viability and luciferase activity after pretreatment of DREAM-F cells with reagents of interest and post-treatment with UVB radiation, and vice versa. In the second step, we validated certain effective reagents identified in the first step by analyzing the cell cycle, evaluating cell death, and performing HPRT-DNA sequencing in DREAM-F cells treated with these reagents and UVB. This DREAM system is scalable and forms a time-saving high-throughput screening system for identifying novel anti-photoaging reagents regulating DNA damage in dermal fibroblasts.

In vivo identification of tumor suppressive PTEN ceRNAs in an oncogenic BRAF-induced mouse model of melanoma

PubMed Central

Karreth, Florian A.; Tay, Yvonne; Perna, Daniele; Ala, Ugo; Tan, Shen Mynn; Rust, Alistair G.; DeNicola, Gina; Webster, Kaitlyn A.; Weiss, Dror; Perez-Mancera, Pedro A.; Krauthammer, Michael; Halaban, Ruth; Provero, Paolo; Adams, David J.; Tuveson, David A.; Pandolfi, Pier Paolo

2011-01-01

Summary We recently proposed that competitive endogenous RNAs (ceRNAs) sequester microRNAs to regulate mRNA transcripts containing common microRNA recognition elements (MREs). However, the functional role of ceRNAs in cancer remains unknown. Loss of PTEN, a tumor suppressor regulated by ceRNA activity, frequently occurs in melanoma. Here, we report the discovery of significant enrichment of putative PTEN ceRNAs among genes whose loss accelerates tumorigenesis following Sleeping Beauty insertional mutagenesis in a mouse model of melanoma. We validated several putative PTEN ceRNAs and further characterized one, the ZEB2 transcript. We show that ZEB2 modulates PTEN protein levels in a microRNA-dependent, protein coding-independent manner. Attenuation of ZEB2 expression activates the PI3K/AKT pathway, enhances cell transformation, and commonly occurs in human melanomas and other cancers expressing low PTEN levels. Our study genetically identifies multiple putative microRNA decoys for PTEN, validates ZEB2 mRNA as a bona fide PTEN ceRNA, and demonstrates that abrogated ZEB2 expression cooperates with BRAFV600E to promote melanomagenesis. PMID:22000016

Postdoctoral Fellow | Center for Cancer Research

Cancer.gov

The Hernandez lab is seeking a postdoctoral fellow to join the research program, which is focused on interrogating the molecular underpinnings of metastatic colonization. The lab utilizes multi-photon intravital microscopy to mechanistically interrogate and visualize the dynamics of metastatic outgrowth, including the roles of supporting stromal and immune cells. The lab has begun pioneering first-ever human tissue models by repurposing perfusion systems to sustain metastasis-bearing tissue (liver and peritoneum) ex vivo. We envision these models will allow us to 1) evaluate putative metastasis governing genes in human tissue, 2) personalize investigation of the metastatic cascade by leveraging multi-photon imaging with an individual patient’s tumor cells, which will be dissociated, labelled, and subsequently injected into the perfusate to seed that patient’s metastatic target tissue, and 3) utilized tumor-bearing tissue as a platform for drug discovery and evaluation of novel drug-delivery combinations. We believe our human tissue models have the potential to transcend multiple disciplines in translational medicine and permit investigations and manipulations not previously possible.

Recent studies on the developing human hepatocellular carcinoma.

PubMed

Gerber, M A

1986-01-01

From our knowledge of characteristic phenotypic changes of the preneoplastic lesions during the stepwise evolution of hepatocellular carcinoma (HCC) in experimental models, we are now beginning to define the structural, histochemical, biochemical, antigenic and molecular properties of early HCC and of the putative preneoplastic changes in human liver. Histological, ultrastructural, morphometric and immunohistochemical studies suggest that adenomatous nodules of regenerating and hyperplastic hepatocytes are more likely to represent direct precursors of HCC than dysplastic hepatocytes. Histochemical and immunomorphological investigations show appreciable functional and phenotypic heterogeneity of human HCC as previously recognized in experimental hepatocarcinogenesis. Studies of altered expression of oncogenes in the regenerating liver and HCC are beginning to define the molecular mechanisms in cell growth and malignant transformation. Although integration of Hepadna viral DNA sequences frequently occurs during persistent infection in man and animals, the exact mechanism of viral oncogenesis remains to be elucidated. It is likely that the development of monoclonal antibodies to surface antigens on transformed hepatocytes will be useful for exploring lineage relationships between the cell populations involved in hepatocarcinogenesis.

Unusual varieties and duplication of Rig-I like receptors encoded in the marine mollusk, Crassostrea gigas

NASA Astrophysics Data System (ADS)

Tian, Z. H.; Jiao, C. Z.

2017-07-01

RIG-I like receptors (RLRs) play key roles in sensing non-self nucleic acids in cytoplasm and trigger antiviral innate immune response in vertebrates and human body. Here we carried out in silico analysis to identify and investigate the putative RLRs encoded in the genome of marine mollusk, Crassostrea gigas (cgRLRs), an invertebrate species. We found the unusual duplication and varieties on domain architecture of putative cgRLRs encoded in the genome of C. gigas. Three putative cgRLRs (accessions numbers are EKC24603, EKC31344.1 and EKC38304.1 on GenBank), have the similar domain architecture with that of human RIG-I or MDA5, and one protein (EKC34573.1) with that of human LGP2; The fifth putative cgRLRs (EKC38303.1) is somewhat similar with human RIG-I/MDA5 except that it has only one caspase activation and recruitment domain (CARD) in its N-terminal. Other nine proteins were identified to be partialy similar with RLRs while with the incomplete sequences, which maybe reflect the events of partial duplication of cgRLRs genes occurred in the oyster genome.

The gene expression profile of non-cultured, highly purified human adipose tissue pericytes: Transcriptomic evidence that pericytes are stem cells in human adipose tissue

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

Silva Meirelles, Lindolfo da, E-mail: lindolfomeirelles@gmail.com; Laboratory for Stem Cells and Tissue Engineering, PPGBioSaúde, Lutheran University of Brazil, Av. Farroupilha 8001, 92425-900 Canoas, RS; Deus Wagatsuma, Virgínia Mara de

Pericytes (PCs) are a subset of perivascular cells that can give rise to mesenchymal stromal cells (MSCs) when culture-expanded, and are postulated to give rise to MSC-like cells during tissue repair in vivo. PCs have been suggested to behave as stem cells (SCs) in situ in animal models, although evidence for this role in humans is lacking. Here, we analyzed the transcriptomes of highly purified, non-cultured adipose tissue (AT)-derived PCs (ATPCs) to detect gene expression changes that occur as they acquire MSC characteristics in vitro, and evaluated the hypothesis that human ATPCs exhibit a gene expression profile compatible with anmore » AT SC phenotype. The results showed ATPCs are non-proliferative and express genes characteristic not only of PCs, but also of AT stem/progenitor cells. Additional analyses defined a gene expression signature for ATPCs, and revealed putative novel ATPC markers. Almost all AT stem/progenitor cell genes differentially expressed by ATPCs were not expressed by ATMSCs or culture-expanded ATPCs. Genes expressed by ATMSCs but not by ATPCs were also identified. These findings strengthen the hypothesis that PCs are SCs in vascularized tissues, highlight gene expression changes they undergo as they assume an MSC phenotype, and provide new insights into PC biology. - Highlights: • Non-cultured adipose tissue-derived human pericytes (ncATPCs) exhibit a distinctive gene expression signature. • ncATPCs express key adipose tissue stem cell genes previously described in vivo in mice. • ncATPCs express message for anti-proliferative and antiangiogenic molecules. • Most ncATPC-specific transcripts are absent in culture-expanded pericytes or ATMSCs • Gene expression changes ncATPCs undergo as they acquire a cultured ATMSC phenotype are pointed out.« less

Regulation of myeloid leukemia factor-1 interacting protein (MLF1IP) expression in glioblastoma.

PubMed

Hanissian, Silva H; Teng, Bin; Akbar, Umar; Janjetovic, Zorica; Zhou, Qihong; Duntsch, Christopher; Robertson, Jon H

2005-06-14

The myelodysplasia/myeloid leukemia factor 1-interacting protein MLF1IP is a novel gene which encodes for a putative transcriptional repressor. It is localized to human chromosome 4q35.1 and is expressed in both the nuclei and cytoplasm of cells. Northern and Western blot analyses have revealed MLF1IP to be present at very low amounts in normal brain tissues, whereas a number of human and rat glioblastoma (GBM) cell lines demonstrated a high level expression of the MLF1IP protein. Immunohistochemical analysis of rat F98 and C6 GBM tumor models showed that MLF1IP was highly expressed in the tumor core where it was co-localized with MLF1 and nestin. Moreover, MLF1IP expression was elevated in the contralateral brain where no tumor cells were detected. These observations, together with previous data demonstrating a role for MLF1IP in erythroleukemias, suggest a possible function for this protein in glioma pathogenesis and potentially in other types of malignancies.

Anopheles Midgut Epithelium Evades Human Complement Activity by Capturing Factor H from the Blood Meal

PubMed Central

Khattab, Ayman; Barroso, Marta; Miettinen, Tiera; Meri, Seppo

2015-01-01

Hematophagous vectors strictly require ingesting blood from their hosts to complete their life cycles. Exposure of the alimentary canal of these vectors to the host immune effectors necessitates efficient counteractive measures by hematophagous vectors. The Anopheles mosquito transmitting the malaria parasite is an example of hematophagous vectors that within seconds can ingest human blood double its weight. The innate immune defense mechanisms, like the complement system, in the human blood should thereby immediately react against foreign cells in the mosquito midgut. A prerequisite for complement activation is that the target cells lack complement regulators on their surfaces. In this work, we analyzed whether human complement is active in the mosquito midgut, and how the mosquito midgut cells protect themselves against complement attack. We found that complement remained active for a considerable time and was able to kill microbes within the mosquito midgut. However, the Anopheles mosquito midgut cells were not injured. These cells were found to protect themselves by capturing factor H, the main soluble inhibitor of the alternative complement pathway. Factor H inhibited complement on the midgut cells by promoting inactivation of C3b to iC3b and preventing the activity of the alternative pathway amplification C3 convertase enzyme. An interference of the FH regulatory activity by monoclonal antibodies, carried to the midgut via blood, resulted in increased mosquito mortality and reduced fecundity. By using a ligand blotting assay, a putative mosquito midgut FH receptor could be detected. Thereby, we have identified a novel mechanism whereby mosquitoes can tolerate human blood. PMID:25679788

Generation and Characterization of an Immortalized Human Esophageal Myofibroblast Line.

PubMed

Niu, Chao; Chauhan, Uday; Gargus, Matthew; Shaker, Anisa

2016-01-01

Stromal cells with a myofibroblast phenotype present in the normal human esophagus are increased in individuals with gastro-esophageal reflux disease (GERD). We have previously demonstrated that myofibroblasts stimulated with acid and TLR4 agonists increase IL-6 and IL-8 secretion using primary cultures of myofibroblasts established from normal human esophagus. While primary cultures have the advantage of reflecting the in vivo environment, a short life span and unavoidable heterogeneity limits the usefulness of this model in larger scale in vitro cellular signaling studies. The major aim of this paper therefore was to generate a human esophageal myofibroblast line with an extended lifespan. In the work presented here we have generated and characterized an immortalized human esophageal myofibroblast line by transfection with a commercially available GFP-hTERT lentivirus. Immortalized human esophageal myofibroblasts demonstrate phenotypic, genotypic and functional similarity to primary cultures of esophageal myofibroblasts we have previously described. We found that immortalized esophageal myofibroblasts retain myofibroblast spindle-shaped morphology at low and high confluence beyond passage 80, and express α-SMA, vimentin, and CD90 myofibroblast markers. Immortalized human esophageal myofibroblasts also express the putative acid receptor TRPV1 and TLR4 and retain the functional capacity to respond to stimuli encountered in GERD with secretion of IL-6. Finally, immortalized human esophageal myofibroblasts also support the stratified growth of squamous esophageal epithelial cells in 3D organotypic cultures. This newly characterized immortalized human esophageal myofibroblast cell line can be used in future cellular signaling and co-culture studies.

PuTmiR: A database for extracting neighboring transcription factors of human microRNAs

PubMed Central

2010-01-01

Background Some of the recent investigations in systems biology have revealed the existence of a complex regulatory network between genes, microRNAs (miRNAs) and transcription factors (TFs). In this paper, we focus on TF to miRNA regulation and provide a novel interface for extracting the list of putative TFs for human miRNAs. A putative TF of an miRNA is considered here as those binding within the close genomic locality of that miRNA with respect to its starting or ending base pair on the chromosome. Recent studies suggest that these putative TFs are possible regulators of those miRNAs. Description The interface is built around two datasets that consist of the exhaustive lists of putative TFs binding respectively in the 10 kb upstream region (USR) and downstream region (DSR) of human miRNAs. A web server, named as PuTmiR, is designed. It provides an option for extracting the putative TFs for human miRNAs, as per the requirement of a user, based on genomic locality, i.e., any upstream or downstream region of interest less than 10 kb. The degree distributions of the number of putative TFs and miRNAs against each other for the 10 kb USR and DSR are analyzed from the data and they explore some interesting results. We also report about the finding of a significant regulatory activity of the YY1 protein over a set of oncomiRNAs related to the colon cancer. Conclusion The interface provided by the PuTmiR web server provides an important resource for analyzing the direct and indirect regulation of human miRNAs. While it is already an established fact that miRNAs are regulated by TFs binding to their USR, this database might possibly help to study whether an miRNA can also be regulated by the TFs binding to their DSR. PMID:20398296

Pre-existing Epithelial Diversity in Normal Human Livers: A Tissue-tethered Cytometric Analysis in Portal/Periportal Epithelial Cells

PubMed Central

Isse, Kumiko; Lesniak, Andrew; Grama, Kedar; Maier, John; Specht, Susan; Castillo-Rama, Marcela; Lunz, John; Roysam, Badrinath; Michalopoulos, George; Demetris, Anthony J.

2012-01-01

Routine light microscopy identifies two distinct epithelial cell populations in normal human livers: hepatocytes and biliary epithelial cells (BEC). Considerable epithelial diversity, however, arises during disease states when a variety of hepatocyte-BEC hybrid cells appear. This has been attributed to activation and differentiation of putative hepatic progenitor cells (HPC) residing in the Canals of Hering and/or metaplasia of pre-existing mature epithelial cells. A novel analytic approach consisting of multiplex labeling, high resolution whole slide imaging (WSI), and automated image analysis was used to determine if more complex epithelial cell phenotypes pre-existed in normal adult human livers, which might provide an alternative explanation for disease-induced epithelial diversity. “Virtually digested” WSI enabled quantitative cytometric analyses of individual cells displayed in a variety of formats (e.g. scatter plots) while still tethered to the WSI and tissue structure. We employed biomarkers specifically-associated with mature epithelial forms (HNF4α for hepatocytes, CK19 and HNF1β for BEC) and explored for the presence of cells with hybrid biomarker phenotypes. Results showed abundant hybrid cells in portal bile duct BEC, canals of Hering, and immediate periportal hepatocytes. These bi-potential cells likely serve as a reservoir for the epithelial diversity of ductular reactions, appearance of hepatocytes in bile ducts, and the rapid and fluid transition of BEC to hepatocytes, and vice versa. Conclusion Novel imaging and computational tools enable increased information extraction from tissue samples and quantify the considerable pre-existent hybrid epithelial diversity in normal human liver. This computationally-enabled tissue analysis approach offers much broader potential beyond the results presented here. PMID:23150208

The Varicella-zoster virus DNA encapsidation genes: Identification and characterization of the putative terminase subunits

PubMed Central

Visalli, Robert J.; Nicolosi, Denise M.; Irven, Karen L.; Goshorn, Bradley; Khan, Tamseel; Visalli, Melissa A.

2007-01-01

The putative DNA encapsidation genes encoded by open reading frames (ORFs) 25, 26, 30, 34, 43, 45/42 and 54 were cloned from Varicella-zoster virus (VZV) strain Ellen. Sequencing revealed that the Ellen ORFs were highly conserved at the amino acid level when compared to those of nineteen previously published VZV isolates. Additionally, RT-PCR provided the first evidence that ORF45/42 was expressed as a spliced transcript in VZV-infected cells. All seven ORFs were expressed in vitro and full length products were identified using a C-terminal V5 epitope tag. The in vitro products of the putative VZV terminase subunits encoded by ORFs 30 and 45/42 proved useful in protein-protein interaction assays. Previous studies have reported the formation of a heterodimeric terminase complex involved in DNA encapsidation for both herpes simplex virus-type 1 (HSV-1) and human cytomegalovirus (HCMV). Here we report that the C-terminal portion of exon II of ORF45/42 (ORF42-C269) interacted in GST-pull down experiments with in vitro synthesized ORF30 and ORF45/42. The interactions were maintained in the presence of anionic detergents and in buffers of increasing ionic strength. Cells transiently transfected with epitope tagged ORF45/42 or ORF30 showed primarily cytoplasmic staining. In contrast, an antiserum directed to the N-terminal portion of ORF45 showed nearly exclusive nuclear localization of the ORF45/42 gene product in infected cells. An ORF30 specific antiserum detected an 87 kDa protein in both the cytoplasmic and nuclear fractions of VZV infected cells. The results were consistent with the localization and function of herpesviral terminase subunits. This is the first study aimed at the identification and characterization of the VZV DNA encapsidation gene products. PMID:17868947

Putative human sperm Interactome: a networks study.

PubMed

Ordinelli, Alessandra; Bernabò, Nicola; Orsini, Massimiliano; Mattioli, Mauro; Barboni, Barbara

2018-04-11

For over sixty years, it has been known that mammalian spermatozoa immediately after ejaculation are virtually infertile. They became able to fertilize only after they reside for long time (hours to days) within female genital tract where they complete their functional maturation, the capacitation. This process is finely regulated by the interaction with the female environment and involves, in spermatozoa, a myriad of molecules as messengers and target of signals. Since, to date, a model able to represent the molecular interaction that characterize sperm physiology does not exist, we realized the Human Sperm Interactme Network3.0 (HSIN3.0) and its main component (HSNI3.0_MC), starting from the pathway active in male germ cells. HSIN3.0 and HSIN3.0_MC are scale free networks, adherent to the Barabasi-Albert model, and are characterised by an ultra-small world topology. We found that they are resistant to random attacks and that are designed to respond quickly and specifically to external inputs. In addition, it has been possible to identify the most connected nodes (the hubs) and the bottlenecks nodes. This result allowed us to explore the control mechanisms active in driving sperm biochemical machinery and to verify the different levels of controls: party vs. date hubs and hubs vs. bottlenecks, thanks the availability of data from KO mice. Finally, we found that several key nodes represent molecules specifically involved in function that are thought to be not present or not active in sperm cells, such as control of cell cycle, proteins synthesis, nuclear trafficking, and immune response, thus potentially open new perspectives on the study of sperm biology. For the first time we present a network representing putative human sperm interactome. This result gives very intriguing biological information and could contribute to the knowledge of spermatozoa, either in physiological or pathological conditions.

Tissue- and cell-type–specific manifestations of heteroplasmic mtDNA 3243A>G mutation in human induced pluripotent stem cell-derived disease model

PubMed Central

Hämäläinen, Riikka H.; Manninen, Tuula; Koivumäki, Hanna; Kislin, Mikhail; Otonkoski, Timo; Suomalainen, Anu

2013-01-01

Mitochondrial DNA (mtDNA) mutations manifest with vast clinical heterogeneity. The molecular basis of this variability is mostly unknown because the lack of model systems has hampered mechanistic studies. We generated induced pluripotent stem cells from patients carrying the most common human disease mutation in mtDNA, m.3243A>G, underlying mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome. During reprogramming, heteroplasmic mtDNA showed bimodal segregation toward homoplasmy, with concomitant changes in mtDNA organization, mimicking mtDNA bottleneck during epiblast specification. Induced pluripotent stem cell–derived neurons and various tissues derived from teratomas manifested cell-type specific respiratory chain (RC) deficiency patterns. Similar to MELAS patient tissues, complex I defect predominated. Upon neuronal differentiation, complex I specifically was sequestered in perinuclear PTEN-induced putative kinase 1 (PINK1) and Parkin-positive autophagosomes, suggesting active degradation through mitophagy. Other RC enzymes showed normal mitochondrial network distribution. Our data show that cellular context actively modifies RC deficiency manifestation in MELAS and that autophagy is a significant component of neuronal MELAS pathogenesis. PMID:24003133

Characterization of putative toxin/antitoxin systems in Vibrio parahaemolyticus.

PubMed

Hino, M; Zhang, J; Takagi, H; Miyoshi, T; Uchiumi, T; Nakashima, T; Kakuta, Y; Kimura, M

2014-07-01

To obtain more information about the toxin/antitoxin (TA) systems in the Vibrio genus and also to examine their involvement in the induction of a viable but nonculturable (VBNC) state, we searched homologues of the Escherichia coli TA systems in the Vibrio parahaemolyticus genome. We found that a gene cluster, vp1842/vp1843, in the V. parahaemolyticus genome database has homology to that encoding the E. coli TA proteins, DinJ/YafQ. Expression of the putative toxin gene vp1843 in E. coli cells strongly inhibited the cell growth, while coexpression with the putative antitoxin gene vp1842 neutralized this effect. Mutational analysis identified Lys37 and Pro45 in the gene product VP1843 of vp1843 as crucial residues for the growth retardation of E. coli cells. VP1843, unlike the E. coli toxin YafQ, has no protein synthesis inhibitory activity, and that instead the expression of vp1843 in E. coli caused morphological change of the cells. The gene cluster vp1842/vp1843 encodes the V. parahaemolyticus TA system; VP1843 inhibits cell growth, whereas VP1842 serves as an antitoxin by forming a stable complex with VP1843. The putative toxin, VP1843, may be involved in the induction of the VBNC state in V. parahaemolyticus by inhibiting cell division. © 2014 The Society for Applied Microbiology.

The Cancer-Related Transcription Factor Runx2 Modulates Cell Proliferation in Human Osteosarcoma Cell Lines

PubMed Central

Lucero, Claudia M.J.; Vega, Oscar A.; Osorio, Mariana M.; Tapia, Julio C.; Antonelli, Marcelo; Stein, Gary S.; Van Wijnen, Andre J.; Galindo, Mario A.

2013-01-01

Runx2 regulates osteogenic differentiation and bone formation, but also suppresses pre-osteoblast proliferation by affecting cell cycle progression in the G1 phase. The growth suppressive potential of Runx2 is normally inactivated in part by protein destabilization, which permits cell cycle progression beyond the G1/S phase transition, and Runx2 is again up-regulated after mitosis. Runx2 expression also correlates with metastasis and poor chemotherapy response in osteosarcoma. Here we show that six human osteosarcoma cell lines (SaOS, MG63, U2OS, HOS, G292, and 143B) have different growth rates, which is consistent with differences in the lengths of the cell cycle. Runx2 protein levels are cell cycle-regulated with respect to the G1/S phase transition in U2OS, HOS, G292, and 143B cells. In contrast, Runx2 protein levels are constitutively expressed during the cell cycle in SaOS and MG63 cells. Forced expression of Runx2 suppresses growth in all cell lines indicating that accumulation of Runx2 in excess of its pre-established levels in a given cell type triggers one or more anti-proliferative pathways in osteosarcoma cells. Thus, regulatory mechanisms controlling Runx2 expression in osteosarcoma cells must balance Runx2 protein levels to promote its putative oncogenic functions, while avoiding suppression of bone tumor growth. PMID:22949168

PUTATIVE CREATINE KINASE M-ISOFORM IN HUMAN SPERM IS IDENTIFIED AS THE 70-KILODALTON HEAT SHOCK PROTEIN HSPA2

EPA Science Inventory

THE PUTATIVE CREATINE KINASE M-ISOFORM IN HUMAN SPERM
IS IDENTIFIED AS THE 70 kDa HEAT SHOCK PROTEIN HSPA2

* Gabor Huszar1, Kathryn Stone2, David Dix3 and Lynne Vigue1
1The Sperm Physiology Laboratory, Department of Obstetrics and Gynecology, 2 W.M. Keck Foundatio...

Regulatory single nucleotide polymorphisms (rSNPs) at the promoters 1A and 1B of the human APC gene.

PubMed

Matveeva, Marina Yu; Kashina, Elena V; Reshetnikov, Vasily V; Bryzgalov, Leonid O; Antontseva, Elena V; Bondar, Natalia P; Merkulova, Tatiana I

2016-12-22

Germline mutations in the coding sequence of the tumour suppressor APC gene give rise to familial adenomatous polyposis (which leads to colorectal cancer) and are associated with many other oncopathologies. The loss of APC function because of deletion of putative promoter 1A or 1B also results in the development of colorectal cancer. Since the regions of promoters 1A and 1B contain many single nucleotide polymorphisms (SNPs), the aim of this study was to perform functional analysis of some of these SNPs by means of an electrophoretic mobility shift assay (EMSA) and a luciferase reporter assay. First, it was shown that both putative promoters of APC (1A and 1B) drive transcription in an in vitro reporter experiment. From eleven randomly selected SNPs of promoter 1A and four SNPs of promoter 1B, nine and two respectively showed differential patterns of binding of nuclear proteins to oligonucleotide probes corresponding to alternative alleles. The luciferase reporter assay showed that among the six SNPs tested, the rs75612255 C allele and rs113017087 C allele in promoter 1A as well as the rs138386816 T allele and rs115658307 T allele in promoter 1B significantly increased luciferase activity in the human erythromyeloblastoid leukaemia cell line K562. In human colorectal cancer HCT-116 cells, none of the substitutions under study had any effect, with the exception of minor allele G of rs79896135 in promoter 1B. This allele significantly decreased the luciferase reporter's activity CONCLUSION: Our results indicate that many SNPs in APC promoters 1A and 1B are functionally relevant and that allele G of rs79896135 may be associated with the predisposition to colorectal cancer.

Identification and Analysis of Putative Homologues of Mechanosensitive Channels in Pathogenic Protozoa

PubMed Central

Prole, David L.; Taylor, Colin W.

2013-01-01

Mechanosensitive channels play important roles in the physiology of many organisms, and their dysfunction can affect cell survival. This suggests that they might be therapeutic targets in pathogenic organisms. Pathogenic protozoa lead to diseases such as malaria, dysentery, leishmaniasis and trypanosomiasis that are responsible for millions of deaths each year worldwide. We analyzed the genomes of pathogenic protozoa and show the existence within them of genes encoding putative homologues of mechanosensitive channels. Entamoeba histolytica, Leishmania spp., Trypanosoma cruzi and Trichomonas vaginalis have genes encoding homologues of Piezo channels, while most pathogenic protozoa have genes encoding homologues of mechanosensitive small-conductance (MscS) and K+-dependent (MscK) channels. In contrast, all parasites examined lack genes encoding mechanosensitive large-conductance (MscL), mini-conductance (MscM) and degenerin/epithelial Na+ (DEG/ENaC) channels. Multiple sequence alignments of evolutionarily distant protozoan, amoeban, plant, insect and vertebrate Piezo channel subunits define an absolutely conserved motif that may be involved in channel conductance or gating. MscS channels are not present in humans, and the sequences of protozoan and human homologues of Piezo channels differ substantially. This suggests the possibility for specific targeting of mechanosensitive channels of pathogens by therapeutic drugs. PMID:23785469

Molecular cloning of the mouse gene coding for {alpha}{sub 2}-macroglobulin and targeting of the gene in embryonic stem cells

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

Umans, L.; Serneels, L.; Hilliker, C.

1994-08-01

The authors have cloned the mouse gene coding for {alpha}{sub 2}-macroglobulin in overlapping {lambda} clones and have analyzed its structure. The gene contains 36 exons, coding for the 4.8-kb cDNA that we cloned previously. Including putative control elements in the 5{prime} flanking region, the gene covers about 45 kb. A region of 3.8 kb, stretching from 835 bases upstream of the cDNA start site to exon 4, including all intervening sequences, was sequenced completely. The analysis demonstrated that the putative promoter region of the mouse A2M gene differed considerably from the known promoter sequences of the human A2M gene andmore » of the rat acute-phas A2M gene. Comparison of the exon-intron structure of all known genes of the A2M family confirmed that the rat acute phase A2M gene is more closely related to the human gene than to the mouse A2M gene. To generate mice with the A2M gene inactivated, an insertion type of construct containing 7.5 kb of genomic DNA of the mouse strain 129/J, encompassing exons 16 to 19, was synthesized. A hygromycin marker gene was embedded in intron 17. After electroporation, 198 hygromycin-resistant ES cell lines were isolated and analyzed by Southern blotting. Five ES cell lines were obtained with one allele of the mouse A2M gene targeted by this insertion construct, demonstrating that the position and the characteristics of the vector served the intended goal.« less

High-Throughput Library Screening Identifies Two Novel NQO1 Inducers in Human Lung Cells

PubMed Central

Marquardt, Gaby; Massimi, Aldo B.; Shi, Miao; Han, Weiguo; Spivack, Simon D.

2012-01-01

Many phytochemicals possess antioxidant and cancer-preventive properties, some putatively through antioxidant response element–mediated phase II metabolism, entailing mutagen/oxidant quenching. In our recent studies, however, most candidate phytochemical agents were not potent in inducing phase II genes in normal human lung cells. In this study, we applied a messenger RNA (mRNA)–specific gene expression–based high throughput in vitro screening approach to discover new, potent plant-derived phase II inducing chemopreventive agents. Primary normal human bronchial epithelial (NHBE) cells and immortalized human bronchial epithelial cells (HBECs) were exposed to 800 individual compounds in the MicroSource Natural Products Library. At a level achievable in humans by diet (1.0 μM), 2,3-dihydroxy-4-methoxy-4′-ethoxybenzophenone (DMEBP), triacetylresveratrol (TRES), ivermectin, sanguinarine sulfate, and daunorubicin induced reduced nicotinamide adenine dinucleotide phosphate:quinone oxidoreductase 1 (NQO1) mRNA and protein expression in NHBE cells. DMEBP and TRES were the most attractive agents as coupling potency and low toxicity for induction of NQO1 (mRNA level, ≥3- to 10.8-fold that of control; protein level, ≥ two- to fourfold that of control). Induction of glutathione S-transferase pi mRNA expression was modest, and none was apparent for glutathione S-transferase pi protein expression. Measurements of reactive oxygen species and glutathione/oxidized glutathione ratio showed an antioxidant effect for DMEBP, but no definite effect was found for TRES in NHBE cells. Exposure of NHBE cells to H2O2 induced nuclear translocation of nuclear factor erythroid 2–related factor 2, but this translocation was not significantly inhibited by TRES and DMEBP. These studies show that potency and low toxicity may align for two potential NQO1-inducing agents, DMEBP and TRES. PMID:22021338

Functional analysis of human aromatic amino acid transporter MCT10/TAT1 using the yeast Saccharomyces cerevisiae.

PubMed

Uemura, Satoshi; Mochizuki, Takahiro; Kurosaka, Goyu; Hashimoto, Takanori; Masukawa, Yuki; Abe, Fumiyoshi

2017-10-01

Tryptophan is an essential amino acid in humans and an important serotonin and melatonin precursor. Monocarboxylate transporter MCT10 is a member of the SLC16A family proteins that mediates low-affinity tryptophan transport across basolateral membranes of kidney, small intestine, and liver epithelial cells, although the precise transport mechanism remains unclear. Here we developed a simple functional assay to analyze tryptophan transport by human MCT10 using a deletion mutant for the high-affinity tryptophan permease Tat2 in Saccharomyces cerevisiae. tat2Δtrp1 cells are defective in growth in YPD medium because tyrosine present in the medium competes for the low-affinity tryptophan permease Tat1 with tryptophan. MCT10 appeared to allow growth of tat2Δtrp1 cells in YPD medium, and accumulate in cells deficient for Rsp5 ubiquitin ligase. These results suggest that MCT10 is functional in yeast, and is subject to ubiquitin-dependent quality control. Whereas growth of Tat2-expressing cells was significantly impaired by neutral pH, that of MCT10-expressing cells was nearly unaffected. This property is consistent with the transport mechanism of MCT10 via facilitated diffusion without a need for pH gradient across the plasma membrane. Single-nucleotide polymorphisms (SNPs) are known to occur in the human MCT10 coding region. Among eight SNP amino acid changes in MCT10, the N81K mutation completely abrogated tryptophan import without any abnormalities in the expression or localization. In the MCT10 modeled structure, N81 appeared to protrude into the putative trajectory of tryptophan. Plasma membrane localization of MCT10 and the variant proteins was also verified in human embryonic kidney 293T cells. Copyright © 2017 Elsevier B.V. All rights reserved.

Spatial expression of components of a calcitonin receptor-like receptor (CRL) signalling system (CRL, calcitonin gene-related peptide, adrenomedullin, adrenomedullin-2/intermedin) in mouse and human heart valves.

PubMed

Pfeil, Uwe; Bharathala, Subhashini; Murtaza, Ghulam; Mermer, Petra; Papadakis, Tamara; Boening, Andreas; Kummer, Wolfgang

2016-12-01

Heart valves are highly organized structures determining the direction of blood flow through the heart. Smooth muscle cells within the valve are thought to play an active role during the heart cycle, rather than being just passive flaps. The mature heart valve is composed of extracellular matrix (ECM), various differentiations of valvular interstitial cells (VIC), smooth muscle cells and overlying endothelium. VIC are important for maintaining the structural integrity of the valve, thereby affecting valve function and ECM remodelling. Accumulating evidence suggests an important role of calcitonin receptor-like receptor (CRL) signalling in preventing heart damage under several pathological conditions. Thus we investigate the existence of a putative CRL signalling system in mouse and human heart valves by real-time RT-PCR, laser-assisted microdissection, immunofluorescence and NADPH-diaphorase histochemistry. Mouse and human heart valves expressed mRNAs for the CRL ligands adrenomedullin (AM), adrenomedullin-2 (AM-2) and calcitonin gene-related peptide (CGRP) and for their receptor components, i.e., CRL and receptor-activity-modifying proteins 1-3. Immunofluorescence analysis revealed AM-, AM-2- and CRL-immunolabelling in endothelial cells and VIC, whereas CGRP immunoreactivity was restricted to nerve fibres and some endothelial cells. Nitric oxide synthase activity, as demonstrated by NADPH-diaphorase histochemistry, was shown mainly in valvular endothelial cells in mice, whereas in human aortic valves, VIC and smooth muscle cells were positive. Our results showed the presence of an intrinsic AM/AM-2/CGRP signalling system in murine and human heart valves with distinct cellular localization, suggesting its involvement in the regulation of valve stiffness and ECM production and turnover.

Human iPSC-Derived Endothelial Cell Sprouting Assay in ...

EPA Pesticide Factsheets

Activation of vascular endothelial cells (ECs) by growth factors initiates a cascade of events in vivo consisting of EC tip cell selection, sprout formation, EC stalk cell proliferation, and ultimately vascular stabilization by support cells. Although EC functional assays can recapitulate one or more aspects of angiogenesis in vitro, they are often limited by a lack of definition to the substratum and lack of dependence on key angiogenic signaling axes. Here, we designed and characterized a chemically-defined model of endothelial sprouting behavior in vitro using human induced pluripotent stem cell-derived endothelial cells (iPSC-ECs). Thiol-ene photopolymerization was used to rapidly encapsulate iPSC-ECs at high density in poly(ethylene glycol) (PEG) hydrogel spheres and subsequently to rapidly encapsulate iPSC-EC-containing hydrogel spheres in a cell-free over-layer. The hydrogel sprouting array here maintained pro-angiogenic phenotype of iPSC-ECs and supported growth factor-dependent proliferation and sprouting behavior. The sprouting model responded appropriately to several reference pharmacological angiogenesis inhibitors, which suggests the functional role of vascular endothelial growth factor, NF-κB, matrix metalloproteinase-2/9, protein kinase activity, and β-tubulin in endothelial sprouting. A blinded screen of 38 putative vascular disrupting compounds (pVDCs) from the US Environmental Protection Agency’s ToxCast library identified five compounds th

Auditory–vocal mirroring in songbirds

PubMed Central

Mooney, Richard

2014-01-01

Mirror neurons are theorized to serve as a neural substrate for spoken language in humans, but the existence and functions of auditory–vocal mirror neurons in the human brain remain largely matters of speculation. Songbirds resemble humans in their capacity for vocal learning and depend on their learned songs to facilitate courtship and individual recognition. Recent neurophysiological studies have detected putative auditory–vocal mirror neurons in a sensorimotor region of the songbird's brain that plays an important role in expressive and receptive aspects of vocal communication. This review discusses the auditory and motor-related properties of these cells, considers their potential role on song learning and communication in relation to classical studies of birdsong, and points to the circuit and developmental mechanisms that may give rise to auditory–vocal mirroring in the songbird's brain. PMID:24778375

Auditory-vocal mirroring in songbirds.

PubMed

Mooney, Richard

2014-01-01

Mirror neurons are theorized to serve as a neural substrate for spoken language in humans, but the existence and functions of auditory-vocal mirror neurons in the human brain remain largely matters of speculation. Songbirds resemble humans in their capacity for vocal learning and depend on their learned songs to facilitate courtship and individual recognition. Recent neurophysiological studies have detected putative auditory-vocal mirror neurons in a sensorimotor region of the songbird's brain that plays an important role in expressive and receptive aspects of vocal communication. This review discusses the auditory and motor-related properties of these cells, considers their potential role on song learning and communication in relation to classical studies of birdsong, and points to the circuit and developmental mechanisms that may give rise to auditory-vocal mirroring in the songbird's brain.

Candida albicans orf19.3727 encodes phytase activity and is essential for human tissue damage

PubMed Central

Fong, Wing-Ping; Samaranayake, Lakshman Perera

2017-01-01

Candida albicans is a clinically important human fungal pathogen. We previously identified the presence of cell-associated phytase activity in C. albicans. Here, we reveal for the first time, that orf19.3727 contributes to phytase activity in C. albicans and ultimately to its virulence potency. Compared with its wild type counterpart, disruption of C. albicans orf19.3727 led to decreased phytase activity, reduced ability to form hyphae, attenuated in vitro adhesion, and reduced ability to penetrate human epithelium, which are the major virulence attributes of this yeast. Thus, orf19.3727 of C. albicans plays a key role in fungal pathogenesis. Further, our data uncover a putative novel strategy for anti-Candidal drug design through inhibition of phytase activity of this common pathogen. PMID:29216308

Synergistic effect of p53 on TSA-induced stanniocalcin 1 expression in human nasopharyngeal carcinoma cells, CNE2.

PubMed

Ching, L Y; Yeung, Bonnie H Y; Wong, Chris K C

2012-06-01

Human stanniocalcin 1 (STC1) has recently been identified as a putative protein factor involved in cellular apoptosis. The use of histone deacetylase inhibitor (i.e. trichostatin A (TSA)) and doxorubicin (Dox) is one of the common treatment methods to induce apoptosis in human cancer cells. A study on TSA and Dox-mediated apoptosis may shed light on the regulation and function of STC1 in cancer treatment. In this study, TSA and Dox cotreatment in human nasopharyngeal carcinoma cells (CNE2) elicited synergistic effects on STC1 gene expression and cellular apoptosis. An activation of p53 (TP53) transcriptional activity in Dox- or Dox+TSA-treated cells was revealed by the increased expression levels of p53 mRNA/protein as well as p53-driven luciferase activities. To elucidate the possible involvement of p53 in STC1 gene transcription, a vector expressing wild-type or dominant negative (DN) p53 was transiently transfected into the cells. Both STC1 promoter luciferase constructs and chromatin immunoprecipitation assays did not support the direct role of p53 in STC1 gene transactivation. However, the synergistic effects of p53 on the induction of NF-κB phosphorylation and the recruitment of acetylated histone H3 in STC1 promoter were observed in TSA-cotreated cells. The overexpression of exogenous STC1 sensitized apoptosis in Dox-treated cells. Taken together, this study provides data to show the cross talk of NF-κB, p53, and histone protein in the regulation of STC1 expression and function.

Telocytes and putative stem cells in ageing human heart

PubMed Central

Popescu, Laurentiu M; Curici, Antoanela; Wang, Enshi; Zhang, Hao; Hu, Shengshou; Gherghiceanu, Mihaela

2015-01-01

Tradition considers that mammalian heart consists of about 70% non-myocytes (interstitial cells) and 30% cardiomyocytes (CMs). Anyway, the presence of telocytes (TCs) has been overlooked, since they were described in 2010 (visit http://www.telocytes.com). Also, the number of cardiac stem cells (CSCs) has not accurately estimated in humans during ageing. We used electron microscopy to identify and estimate the number of cells in human atrial myocardium (appendages). Three age-related groups were studied: newborns (17 days–1 year), children (6–17 years) and adults (34–60 years). Morphometry was performed on low-magnification electron microscope images using computer-assisted technology. We found that interstitial area gradually increases with age from 31.3 ± 4.9% in newborns to 41 ± 5.2% in adults. Also, the number of blood capillaries (per mm2) increased with several hundreds in children and adults versus newborns. CMs are the most numerous cells, representing 76% in newborns, 88% in children and 86% in adults. Images of CMs mitoses were seen in the 17-day newborns. Interestingly, no lipofuscin granules were found in CMs of human newborns and children. The percentage of cells that occupy interstitium were (depending on age): endothelial cells 52–62%; vascular smooth muscle cells and pericytes 22–28%, Schwann cells with nerve endings 6–7%, fibroblasts 3–10%, macrophages 1–8%, TCs about 1% and stem cells less than 1%. We cannot confirm the popular belief that cardiac fibroblasts are the most prevalent cell type in the heart and account for about 20% of myocardial volume. Numerically, TCs represent a small fraction of human cardiac interstitial cells, but because of their extensive telopodes, they achieve a 3D network that, for instance, supports CSCs. The myocardial (very) low capability to regenerate may be explained by the number of CSCs, which decreases fivefold by age (from 0.5% to 0.1% in newborns versus adults). PMID:25545142

Chlorotheolides A and B, Spiroketals Generated via Diels-Alder Reactions in the Endophytic Fungus Pestalotiopsis theae.

PubMed

Liu, Ling; Han, Yu; Xiao, Junhai; Li, Li; Guo, Liangdong; Jiang, Xuejun; Kong, Lingyi; Che, Yongsheng

2016-10-28

Chlorotheolides A (1) and B (2), two new spiroketals possessing the unique [4,7]methanochromene and dispiro-trione skeletons, respectively, and their putative biosynthetic precursors, 1-undecen-2,3-dicarboxylic acid (3) and maldoxin (4), were isolated from the solid substrate fermentation of the plant endophytic fungus Pestalotiopsis theae (N635). Their structures were elucidated based on NMR spectroscopic data and electronic circular dichroism calculations. Biogenetically, compounds 1 and 2 could be generated from the co-isolated 3 and 4 via Diels-Alder reactions. Chlorotheolide (2) showed an antiproliferative effect against the human tumor cell line HeLa and induced an autophagic process in the cells.

Effects of a human recombinant alkaline phosphatase during impaired mitochondrial function in human renal proximal tubule epithelial cells.

PubMed

Peters, Esther; Schirris, Tom; van Asbeck, Alexander H; Gerretsen, Jelle; Eymael, Jennifer; Ashikov, Angel; Adjobo-Hermans, Merel J W; Russel, Frans; Pickkers, Peter; Masereeuw, Rosalinde

2017-02-05

Sepsis-associated acute kidney injury is a multifactorial syndrome in which inflammation and renal microcirculatory dysfunction play a profound role. Subsequently, renal tubule mitochondria reprioritize cellular functions to prevent further damage. Here, we investigated the putative protective effects of human recombinant alkaline phosphatase (recAP) during inhibition of mitochondrial respiration in conditionally immortalized human proximal tubule epithelial cells (ciPTEC). Full inhibition of mitochondrial oxygen consumption was obtained after 24h antimycin A treatment, which did not affect cell viability. While recAP did not affect the antimycin A-induced decreased oxygen consumption and increased hypoxia-inducible factor-1α or adrenomedullin gene expression levels, the antimycin A-induced increase of pro-inflammatory cytokines IL-6 and IL-8 was attenuated. Antimycin A tended to induce the release of detrimental purines ATP and ADP, which reached statistical significance when antimycin A was co-incubated with lipopolysaccharide, and were completely converted into cytoprotective adenosine by recAP. As the adenosine A 2A receptor was up-regulated after antimycin A exposure, an adenosine A 2A receptor knockout ciPTEC cell line was generated in which recAP still provided protection. Together, recAP did not affect oxygen consumption but attenuated the inflammatory response during impaired mitochondrial function, an effect suggested to be mediated by dephosphorylating ATP and ADP into adenosine. Copyright © 2016 Elsevier B.V. All rights reserved.

Inhibition of cell proliferation by nobiletin, a dietary phytochemical, associated with apoptosis and characteristic gene expression, but lack of effect on early rat hepatocarcinogenesis in vivo.

PubMed

Ohnishi, Hiroyuki; Asamoto, Makoto; Tujimura, Kazunari; Hokaiwado, Naomi; Takahashi, Satoru; Ogawa, Kumiko; Kuribayashi, Masanori; Ogiso, Tadashi; Okuyama, Harumi; Shirai, Tomoyuki

2004-12-01

Dietary phytochemicals can inhibit the development of certain types of tumors. We here investigated the effects of nobiletin (Nob), garcinol (Gar), auraptene (Aur), beta-cryptoxanthin- and hesperidine-rich pulp (CHRP) and 1,1'-acetoxychavicol acetate (ACA) on hepatocarcinogenesis in a rat medium-term liver bioassay, and also examined their influence on cell proliferation, cell cycle kinetics, apoptosis and cell invasion of rat and human hepatocellular carcinoma (HCC) cells, MH1C1 and HepG2, respectively. While there were no obvious suppressive effects on the development of putative preneoplastic liver lesions, inhibition of hepatocarcinoma cell proliferation was evident in the Nob group. Nob also caused G2/M cell cycle arrest and apoptosis. Microarray analysis identified a set of genes specifically regulated by Nob, and these are likely to be involved in the observed growth suppression of HCC cells. These results suggest that phytochemicals might have chemopreventive potential in late stages of hepatocarcinogenesis.

Thyroid hormone stimulates progesterone release from human luteal cells by generating a proteinaceous factor.

PubMed

Datta, M; Roy, P; Banerjee, J; Bhattacharya, S

1998-09-01

Blood samples collected from 29 women (aged between 19 and 35 years) during the luteal phase of the menstrual cycle (between days 18 and 23 of the cycle) showed that deficiency in thyroid hormone level is related to a decrease in progesterone (P4) secretion. To observe the effect of thyroid hormone on human ovarian luteal cells, 3,5,3'-triiodothyronine (T3; 125 ng/ml) was added to luteal cells in vitro. T3 significantly stimulated progesterone release (P < 0.01) from luteal cells and this could be blocked by cycloheximide, indicating a protein mediator for the T3 effect. The T3 stimulatory effect was inhibited by anti-T3 antibody suggesting specificity of T3 action. Addition of T3 caused a more than threefold increase in cellular protein synthesis which was inhibited by cycloheximide. Preparation of partially purified thyroid hormone-induced factor (TIF) (from peak II of Sephadex G 100 chromatography of T3-incubated cells), and its addition to luteal cell incubations caused a significant increase in P4 release (P < 0.05). Incubation with trypsin or treatment with heat destroyed the stimulatory effect of TIF on P4 release, indicating the proteinaceous nature of TIF. Purified thyroid hormone-induced protein. (TIP) from rat granulosa cells and fish ovarian follicles greatly stimulated P4 release from human luteal cells. These results suggest that T3 stimulation of P4 release from human luteal cells is not direct, but is mediated through a putative protein factor, which appears to be a protein conserved through evolution as far as its biological activity is concerned.

Molecular and functional characterization of the promoter of ETS2, the human c-ets-2 gene.

PubMed Central

Mavrothalassitis, G J; Watson, D K; Papas, T S

1990-01-01

The 5' end of the human c-ets-2 gene, ETS2, was cloned and characterized. The major transcription initiation start sites were identified, and the pertinent sequences surrounding the ETS2 promoter were determined. The promoter region of ETS2 does not possess typical "TATA" and "CAAT" elements. However, this promoter contains several repeat regions, as well as two consensus AP2 binding sites and three putative Sp1 sites. There is also a palindromic region similar to the serum response element of the c-fos gene, located 1400 base pairs (bp) upstream from the first major transcription initiation site. A G + C-rich sequence (GC element) with dyad symmetry can be seen in the ETS2 promoter, immediately following an unusually long (approximately 250-bp) polypurine-polypyrimidine tract. A series of deletion fragments from the putative promoter region were ligated in front of the bacterial chloramphenicol acetyltransferase gene and tested for activity following transfection into HeLa cells. The 5' boundary of the region needed for maximum promoter activity was found to be 159 bp upstream of the major initiation site. This region of 159 bp contains putative binding sites for transcription factors Sp1 and AP2 (one for each), the GC element, one small forward repeat, one inverted repeat, and half of the polypurine-pyrimidine tract. The promoter of ETS2 (within the polypyrimidine tract) serves to illustrate an alternative structure that may be present in genes with "TATA-less" promoters. Images PMID:2405393

Attention Induced Gain Stabilization in Broad and Narrow-Spiking Cells in the Frontal Eye-Field of Macaque Monkeys

PubMed Central

Brandt, Christian; Dasilva, Miguel; Gotthardt, Sascha; Chicharro, Daniel; Panzeri, Stefano; Distler, Claudia

2016-01-01

Top-down attention increases coding abilities by altering firing rates and rate variability. In the frontal eye field (FEF), a key area enabling top-down attention, attention induced firing rate changes are profound, but its effect on different cell types is unknown. Moreover, FEF is the only cortical area investigated in which attention does not affect rate variability, as assessed by the Fano factor, suggesting that task engagement affects cortical state nonuniformly. We show that putative interneurons in FEF of Macaca mulatta show stronger attentional rate modulation than putative pyramidal cells. Partitioning rate variability reveals that both cell types reduce rate variability with attention, but more strongly so in narrow-spiking cells. The effects are captured by a model in which attention stabilizes neuronal excitability, thereby reducing the expansive nonlinearity that links firing rate and variance. These results show that the effect of attention on different cell classes and different coding properties are consistent across the cortical hierarchy, acting through increased and stabilized neuronal excitability. SIGNIFICANCE STATEMENT Cortical processing is critically modulated by attention. A key feature of this influence is a modulation of “cortical state,” resulting in increased neuronal excitability and resilience of the network against perturbations, lower rate variability, and an increased signal-to-noise ratio. In the frontal eye field (FEF), an area assumed to control spatial attention in human and nonhuman primates, firing rate changes with attention occur, but rate variability, quantified by the Fano factor, appears to be unaffected by attention. Using recently developed analysis tools and models to quantify attention effects on narrow- and broad-spiking cell activity, we show that attention alters cortical state strongly in the FEF, demonstrating that its effect on the neuronal network is consistent across the cortical hierarchy. PMID:27445139

Microspectroscopy of spectral biomarkers associated with human corneal stem cells

PubMed Central

Nakamura, Takahiro; Kelly, Jemma G.; Trevisan, Júlio; Cooper, Leanne J.; Bentley, Adam J.; Carmichael, Paul L.; Scott, Andrew D.; Cotte, Marine; Susini, Jean; Martin-Hirsch, Pierre L.; Kinoshita, Shigeru; Martin, Francis L.

2010-01-01

Purpose Synchrotron-based radiation (SRS) Fourier-transform infrared (FTIR) microspectroscopy potentially provides novel biomarkers of the cell differentiation process. Because such imaging gives a “biochemical-cell fingerprint” through a cell-sized aperture, we set out to determine whether distinguishing chemical entities associated with putative stem cells (SCs), transit-amplifying (TA) cells, or terminally-differentiated (TD) cells could be identified in human corneal epithelium. Methods Desiccated cryosections (10 μm thick) of cornea on barium fluoride infrared transparent windows were interrogated using SRS FTIR microspectroscopy. Infrared analysis was performed through the acquisition of point spectra or image maps. Results Point spectra were subjected to principal component analysis (PCA) to identify distinguishing chemical entities. Spectral image maps to highlight SCs, TA cells, and TD cells of the cornea were then generated. Point spectrum analysis using PCA highlighted remarkable segregation between the three cell classes. Discriminating chemical entities were associated with several spectral differences over the DNA/RNA (1,425–900 cm−1) and protein/lipid (1,800–1480 cm−1) regions. Prominent biomarkers of SCs compared to TA cells and/or TD cells were 1,040 cm−1, 1,080 cm−1, 1,107 cm−1, 1,225 cm−1, 1,400 cm−1, 1,525 cm−1, 1,558 cm−1, and 1,728 cm−1. Chemical entities associated with DNA/RNA conformation (1,080 cm−1 and 1,225 cm−1) were associated with SCs, whereas protein/lipid biochemicals (1,558 cm−1 and 1,728 cm−1) most distinguished TA cells and TD cells. Conclusions SRS FTIR microspectroscopy can be employed to identify differential spectral biomarkers of SCs, TA cells, and/or TD cells in human cornea. This nondestructive imaging technology is a novel approach to characterizing SCs in situ. PMID:20520745

Overexpression of sialomucin complex, a rat homologue of MUC4, inhibits tumor killing by lymphokine-activated killer cells.

PubMed

Komatsu, M; Yee, L; Carraway, K L

1999-05-01

Sialomucin complex (SMC) is a large heterodimeric glycoprotein complex composed of a mucin subunit ascites sialoglycoprotein-1 and a transmembrane subunit ascites sialoglycoprotein-2. It is a rat homologue of human mucin gene MUC4 and is abundantly expressed on the cell surface of highly metastatic ascites 13762 rat mammary adenocarcinoma cells. Because of their extended and rigid structures, mucin-type glycoproteins are suggested to have suppressing effects on cell-cell and cell-matrix interactions. During the metastatic process, these effects presumably cause tumor cell detachment from the primary tumor mass and facilitate escape of the tumor cells from immunosurveillance. Analyses of human breast cancer cells in solid tumors and tumor effusions showed that the more aggressive cells in effusions are stained with polyclonal antibodies against SMC more frequently than cells in solid tumors, suggesting a role for MUC4/SMC in tumor progression and metastasis. Previously, we generated recombinant cDNAs for SMC that vary in the number of mucin repeats to study the putative functions of SMC in tumor metastasis. These cDNAs were transfected into human cancer cell lines and tested for the effect of the expression of this gene. Here, using a tetracycline-responsive inducible expression system, we demonstrate that overexpression of SMC masks the surface antigens on target tumor cells and effectively suppresses tumor cell killing by cytotoxic lymphocytes. This effect results from the ability of SMC to block killer cell binding to the tumor cells and is dependent on both overexpression of the mucin and the number of mucin repeats in the expressed SMC. These results provide an explanation for the proposed role of SMC/MUC4 in tumor progression.

Streptomycin action to the mammalian inner ear vestibular organs: comparison between pigmented guinea pigs and rats.

PubMed

Meza, Graciela; Aguilar-Maldonado, Beatriz

2007-01-01

Streptomycin is the antibiotic of choice to treat tuberculosis and other infectious diseases but it causes vestibular malfunction and hipoacusia. Rodents are usually employed as models of drug action to the inner ear and results are extrapolated to what happens in humans. In rats, streptomycin destroys macular sensory cells and does not affect cochlear ones, whereas in guinea pigs the contrary is true. Action on the vestibular cristae cells involved in vestibulo-ocular reflex integrity is less clear. Thus, we compared this response in both pigmented guinea pigs (Cavia cobaya) and rats (Rattus norvegicus) after parallel streptomycin chronic treatment. In guinea pigs, the reflex was obliterated along treatment time; in rats this behavior was not observed, suggesting that the end organ target was diverse. In recent studies, streptidine, a streptomycin derivative found in the blood of humans and rats treated with streptomycin, was the actual ototoxic agent. The putative streptomycin vestibular organ target observed in humans corresponds with the guinea pig observations. Results observed in rats are controversial: streptidine did not cause any damage either to vestibular cristae nor auditory cells. We hypothesize differential drug metabolism and distribution and conclude that results in laboratory animals may not always be applicable in the human situation.

Applications of CRISPR genome editing technology in drug target identification and validation.

PubMed

Lu, Quinn; Livi, George P; Modha, Sundip; Yusa, Kosuke; Macarrón, Ricardo; Dow, David J

2017-06-01

The analysis of pharmaceutical industry data indicates that the major reason for drug candidates failing in late stage clinical development is lack of efficacy, with a high proportion of these due to erroneous hypotheses about target to disease linkage. More than ever, there is a requirement to better understand potential new drug targets and their role in disease biology in order to reduce attrition in drug development. Genome editing technology enables precise modification of individual protein coding genes, as well as noncoding regulatory sequences, enabling the elucidation of functional effects in human disease relevant cellular systems. Areas covered: This article outlines applications of CRISPR genome editing technology in target identification and target validation studies. Expert opinion: Applications of CRISPR technology in target validation studies are in evidence and gaining momentum. Whilst technical challenges remain, we are on the cusp of CRISPR being applied in complex cell systems such as iPS derived differentiated cells and stem cell derived organoids. In the meantime, our experience to date suggests that precise genome editing of putative targets in primary cell systems is possible, offering more human disease relevant systems than conventional cell lines.

H19, a marker of developmental transition, is reexpressed in human atherosclerotic plaques and is regulated by the insulin family of growth factors in cultured rabbit smooth muscle cells.

PubMed

Han, D K; Khaing, Z Z; Pollock, R A; Haudenschild, C C; Liau, G

1996-03-01

H19 is a developmentally regulated gene with putative tumor suppressor activity, and loss of H19 expression may be involved in Wilms' tumorigenesis. In this report, we have performed in situ hybridization analysis of H19 expression during normal rabbit development and in human atherosclerotic plaques. We have also used cultured smooth muscle cells to identify H19 regulatory factors. Our data indicate that H19 expression in the developing skeletal and smooth muscles correlated with specific differentiation events in these tissues. Expression of H19 in the skeletal muscle correlated with nonproliferative, actin-positive muscle cells. In the prenatal blood vessel, H19 expression was both temporally and spatially regulated with initial loss of expression in the inner smooth muscle layers adjacent to the lumen. We also identified H19-positive cells within the adult atherosclerotic lesion and we suggest that these cells may recapitulate earlier developmental events. These results, along with the identification of the insulin family of growth factors as potent regulatory molecules for H19 expression, provide additional clues toward understanding the physiological regulation and function of H19.

H19, a marker of developmental transition, is reexpressed in human atherosclerotic plaques and is regulated by the insulin family of growth factors in cultured rabbit smooth muscle cells.

PubMed Central

Han, D K; Khaing, Z Z; Pollock, R A; Haudenschild, C C; Liau, G

1996-01-01

H19 is a developmentally regulated gene with putative tumor suppressor activity, and loss of H19 expression may be involved in Wilms' tumorigenesis. In this report, we have performed in situ hybridization analysis of H19 expression during normal rabbit development and in human atherosclerotic plaques. We have also used cultured smooth muscle cells to identify H19 regulatory factors. Our data indicate that H19 expression in the developing skeletal and smooth muscles correlated with specific differentiation events in these tissues. Expression of H19 in the skeletal muscle correlated with nonproliferative, actin-positive muscle cells. In the prenatal blood vessel, H19 expression was both temporally and spatially regulated with initial loss of expression in the inner smooth muscle layers adjacent to the lumen. We also identified H19-positive cells within the adult atherosclerotic lesion and we suggest that these cells may recapitulate earlier developmental events. These results, along with the identification of the insulin family of growth factors as potent regulatory molecules for H19 expression, provide additional clues toward understanding the physiological regulation and function of H19. PMID:8636440

Cloning, identification, and functional analysis of bone marrow stromal cell antigen-2 from sika deer (Cervus nippon).

PubMed

Wang, Jiawen; Bian, Shuai; Liu, Meichun; Zhang, Xin; Wang, Siming; Bai, Xueyuan; Zhao, Daqing; Zhao, Yu

2018-06-30

BST-2(tetherin/CD317/HM1.24) has been identified as a cellular antiviral factor that inhibits the release of a wide range of enveloped viruses from infected cells. Orthologs of BST-2 have been identified in several species including humans, monkeys, cows, sheep, pigs, and mice. In this study, we cloned the gene and characterized the protein of the BST-2 homolog from sika deer (Cervus nippon). cnBST-2 shares 37.8% and 74.2% identity with the BST-2 homologs from Homo sapiens and Ovis aries, respectively. The extracellular domain of cnBST-2 has two putative N-linked glycosylation sites and three potential dimerization sites. cnBST-2 was shown to be expressed on the cell surface, like human BST-2. Exogenous expression of cnBST-2 resulted in potent inhibition of HIV-1 particle release in 293T cells; however, this activity resisted antagonism by HIV-1 Vpu. Moreover, cnBST-2 was not able to activate nuclear factor-κB, in contrast to human BST-2. This study is the first report of the isolation and characterization of BST-2 from C. nippon. Copyright © 2018 Elsevier B.V. All rights reserved.

microRNA-145 modulates epithelial-mesenchymal transition and suppresses proliferation, migration and invasion by targeting SIP1 in human cervical cancer cells.

PubMed

Sathyanarayanan, Anusha; Chandrasekaran, Karthik Subramanian; Karunagaran, Devarajan

2017-04-01

Previously, it has been reported that microRNA-145 (miR-145) is lowly expressed in human cervical cancers and that its putative tumour suppressive role may be attributed to epithelial-mesenchymal transition (EMT) regulation. Here, we aimed to assess whether miR-145 may affect EMT-associated markers/genes and suppress cervical cancer growth and motility, and to provide a mechanistic basis for these phenomena. The identification of the SMAD-interacting protein 1 (SIP1) mRNA as putative miR-145 target was investigated using a 3' untranslated region (3'UTR) luciferase assay and Western blotting, respectively. The functional effects of exogenous miR-145 expression, miR-145 suppression or siRNA-mediated SIP1 expression down-regulation in cervical cancer-derived C33A and SiHa cells were analysed using Western blotting, BrdU incorporation (proliferation), transwell migration and invasion assays. In addition, the expression levels of miR-145 and SIP1 were determined in primary human cervical cancer and non-cancer tissue samples using qRT-PCR. We found that miR-145 binds to the wild-type 3'UTR of SIP1, but not to its mutant counterpart, and that, through this binding, miR-145 can effectively down-regulate SIP1 expression. In addition, we found that exogenous miR-145 expression or siRNA-mediated down-regulation of SIP1 expression attenuates the proliferation, migration and invasion of C33A and SiHa cells and alters the expression of the EMT-associated markers CDH1, VIM and SNAI1, whereas inhibition of endogenous miR-145 expression elicited the opposite effects. The expression of miR-145 in cervical cancer tissue samples was found to be low, while that of SIP1 was found to be high compared to non-cancerous cervical tissues. An inverse expression correlation between the two was substantiated through the anlaysis of data deposited in the TCGA database. Our data indicate that low miR-145 expression levels in conjunction with elevated SIP1 expression levels may contribute to cervical cancer development. MiR-145-mediated regulation of SIP1 provides a novel mechanistic basis for its tumour suppressive mode of action in human cervical cancer cells.

Identification of human cyclin-dependent kinase 8, a putative protein kinase partner for cyclin C.

PubMed Central

Tassan, J P; Jaquenoud, M; Léopold, P; Schultz, S J; Nigg, E A

1995-01-01

Metazoan cyclin C was originally isolated by virtue of its ability to rescue Saccharomyces cerevisiae cells deficient in G1 cyclin function. This suggested that cyclin C might play a role in cell cycle control, but progress toward understanding the function of this cyclin has been hampered by the lack of information on a potential kinase partner. Here we report the identification of a human protein kinase, K35 [cyclin-dependent kinase 8 (CDK8)], that is likely to be a physiological partner of cyclin C. A specific interaction between K35 and cyclin C could be demonstrated after translation of CDKs and cyclins in vitro. Furthermore, cyclin C could be detected in K35 immunoprecipitates prepared from HeLa cells, indicating that the two proteins form a complex also in vivo. The K35-cyclin C complex is structurally related to SRB10-SRB11, a CDK-cyclin pair recently shown to be part of the RNA polymerase II holoenzyme of S. cerevisiae. Hence, we propose that human K35(CDK8)-cyclin C might be functionally associated with the mammalian transcription apparatus, perhaps involved in relaying growth-regulatory signals. Images Fig. 2 Fig. 3 PMID:7568034

Toward the human cellular microRNAome.

PubMed

McCall, Matthew N; Kim, Min-Sik; Adil, Mohammed; Patil, Arun H; Lu, Yin; Mitchell, Christopher J; Leal-Rojas, Pamela; Xu, Jinchong; Kumar, Manoj; Dawson, Valina L; Dawson, Ted M; Baras, Alexander S; Rosenberg, Avi Z; Arking, Dan E; Burns, Kathleen H; Pandey, Akhilesh; Halushka, Marc K

2017-10-01

MicroRNAs are short RNAs that serve as regulators of gene expression and are essential components of normal development as well as modulators of disease. MicroRNAs generally act cell-autonomously, and thus their localization to specific cell types is needed to guide our understanding of microRNA activity. Current tissue-level data have caused considerable confusion, and comprehensive cell-level data do not yet exist. Here, we establish the landscape of human cell-specific microRNA expression. This project evaluated 8 billion small RNA-seq reads from 46 primary cell types, 42 cancer or immortalized cell lines, and 26 tissues. It identified both specific and ubiquitous patterns of expression that strongly correlate with adjacent superenhancer activity. Analysis of unaligned RNA reads uncovered 207 unknown minor strand (passenger) microRNAs of known microRNA loci and 495 novel putative microRNA loci. Although cancer cell lines generally recapitulated the expression patterns of matched primary cells, their isomiR sequence families exhibited increased disorder, suggesting DROSHA- and DICER1-dependent microRNA processing variability. Cell-specific patterns of microRNA expression were used to de-convolute variable cellular composition of colon and adipose tissue samples, highlighting one use of these cell-specific microRNA expression data. Characterization of cellular microRNA expression across a wide variety of cell types provides a new understanding of this critical regulatory RNA species. © 2017 McCall et al.; Published by Cold Spring Harbor Laboratory Press.

Putative outer membrane proteins of Leptospira interrogans stimulate human umbilical vein endothelial cells (HUVECS) and express during infection.

PubMed

Gómez, Ricardo M; Vieira, Monica L; Schattner, Mirta; Malaver, Elisa; Watanabe, Monica M; Barbosa, Angela S; Abreu, Patricia A E; de Morais, Zenaide M; Cifuente, Javier O; Atzingen, Marina V; Oliveira, Tatiane R; Vasconcellos, Silvio A; Nascimento, Ana L T O

2008-01-01

Cell adhesion molecules (CAMs) are surface receptors present in eukaryotic cells that mediate cell-cell or cell-extracellular matrix interactions. Vascular endothelium stimulation in vitro that lead to the upregulation of CAMs was reported for the pathogenic spirochaetes, including rLIC10365 of Leptospira interrogans. In this study, we report the cloning of LIC10507, LIC10508, LIC10509 genes of L. interrogans using Escherichia coli as a host system. The rational for selecting these sequences is due to their location in L. interrogans serovar Copenhageni genome that has a potential involvement in pathogenesis. The genes encode for predicted lipoproteins with no assigned functions. The purified recombinant proteins were capable to promote the upregulation of intercellular adhesion molecule 1 (ICAM-1) and E-selectin on monolayers of human umbilical vein endothelial cells (HUVECS). In addition, the coding sequences are expressed in the renal tubules of animal during bacterial experimental infection. The proteins are probably located at the outer membrane of the bacteria since they are detected in detergent-phase of L. interrogans Triton X-114 extract. Altogether our data suggest a possible involvement of these proteins during bacterial infection and provide new insights into the role of this region in the pathogenesis of Leptospira.

Human YKL39 (chitinase 3-like protein 2), an osteoarthritis-associated gene, enhances proliferation and type II collagen expression in ATDC5 cells

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

Miyatake, Kazumasa; Tsuji, Kunikazu, E-mail: ktsuji.gcoe@tmd.ac.jp; Yamaga, Mika

Highlights: ► hYKL-39 expression is increased in osteoarthritic articular chondrocytes. ► To examine the molecular functions of hYKL-39 in chondrocytes, we overexpressed hYKL-39 in chondrocytic ATDC5 cells. ► hYKL-39 enhanced proliferation and colony formation in ATDC5 cells. ► hYKL-39 increased type II collagen expression in ATDC5 cells treated with chondrogenic medium. -- Abstract: Human YKL39 (chitinase 3-like protein 2/CHI3L2) is a secreted 39 kDa protein produced by articular chondrocytes and synoviocytes. Recent studies showed that hYKL-39 expression is increased in osteoarthritic articular chondrocytes suggesting the involvement of hYKL-39 in the progression of osteoarthritis (OA). However little is known regarding themore » molecular function of hYKL-39 in joint homeostasis. Sequence analyses indicated that hYKL-39 has significant identity with the human chitotorisidase family molecules, although it is considered that hYKL-39 has no enzymatic activity since it lacks putative chitinase catalytic motif. In this study, to examine the molecular function of hYKL-39 in chondrocytes, we overexpressed hYKL-39 in ATDC5 cells. Here we report that hYKL-39 enhances colony forming activity, cell proliferation, and type II collagen expression in these cells. These data suggest that hYKL-39 is a novel growth and differentiation factor involved in cartilage homeostasis.« less

Identification of CD166 as a Surface Marker for Enriching Prostate Stem/Progenitor and Cancer Initiating Cells

PubMed Central

Wang, Shunyou; Tran, Linh M.; Goldstein, Andrew S.; Lawson, Devon; Chen, Donghui; Li, Yunfeng; Guo, Changyong; Zhang, Baohui; Fazli, Ladan; Gleave, Martin; Witte, Owen N.; Garraway, Isla P.; Wu, Hong

2012-01-01

New therapies for late stage and castration resistant prostate cancer (CRPC) depend on defining unique properties and pathways of cell sub-populations capable of sustaining the net growth of the cancer. One of the best enrichment schemes for isolating the putative stem/progenitor cell from the murine prostate gland is Lin-;Sca1+;CD49fhi (LSChi), which results in a more than 10-fold enrichment for in vitro sphere-forming activity. We have shown previously that the LSChi subpopulation is both necessary and sufficient for cancer initiation in the Pten-null prostate cancer model. To further improve this enrichment scheme, we searched for cell surface molecules upregulated upon castration of murine prostate and identified CD166 as a candidate gene. CD166 encodes a cell surface molecule that can further enrich sphere-forming activity of WT LSChi and Pten null LSChi. Importantly, CD166 could enrich sphere-forming ability of benign primary human prostate cells in vitro and induce the formation of tubule-like structures in vivo. CD166 expression is upregulated in human prostate cancers, especially CRPC samples. Although genetic deletion of murine CD166 in the Pten null prostate cancer model does not interfere with sphere formation or block prostate cancer progression and CRPC development, the presence of CD166 on prostate stem/progenitors and castration resistant sub-populations suggest that it is a cell surface molecule with the potential for targeted delivery of human prostate cancer therapeutics. PMID:22880034

SILAC proteomics of planarians identifies Ncoa5 as a conserved component of pluripotent stem cells.

PubMed

Böser, Alexander; Drexler, Hannes C A; Reuter, Hanna; Schmitz, Henning; Wu, Guangming; Schöler, Hans R; Gentile, Luca; Bartscherer, Kerstin

2013-11-27

Planarian regeneration depends on the presence of pluripotent stem cells in the adult. We developed an in vivo stable isotope labeling by amino acids in cell culture (SILAC) protocol in planarians to identify proteins that are enriched in planarian stem cells. Through a comparison of SILAC proteomes of normal and stem cell-depleted planarians and of a stem cell-enriched population of sorted cells, we identified hundreds of stem cell proteins. One of these is an ortholog of nuclear receptor coactivator-5 (Ncoa5/CIA), which is known to regulate estrogen-receptor-mediated transcription in human cells. We show that Ncoa5 is essential for the maintenance of the pluripotent stem cell population in planarians and that a putative mouse ortholog is expressed in pluripotent cells of the embryo. Our study thus identifies a conserved component of pluripotent stem cells, demonstrating that planarians, in particular, when combined with in vivo SILAC, are a powerful model in stem cell research. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

Genetic Lineage Tracing of Non-Myocyte Population by Dual Recombinases.

PubMed

Li, Yan; He, Lingjuan; Huang, Xiuzhen; Issa Bhaloo, Shirin; Zhao, Huan; Zhang, Shaohua; Pu, Wenjuan; Tian, Xueying; Li, Yi; Liu, Qiaozhen; Yu, Wei; Zhang, Libo; Liu, Xiuxiu; Liu, Kuo; Tang, Juan; Zhang, Hui; Cai, Dongqing; Adams, Ralf H; Xu, Qingbo; Lui, Kathy O; Zhou, Bin

2018-04-26

Background -Whether the adult mammalian heart harbors cardiac stem cells (CSCs) for regeneration of cardiomyocytes is an important yet contentious topic in the field of cardiovascular regeneration. The putative myocyte stem cell populations recognized without specific cell markers such as the cardiosphere-derived cells or with markers such as Sca1 + , Bmi1 + , Isl1 + or Abcg2 + CSCs have been reported. Moreover, it remains unclear whether putative CSCs with unknown or unidentified markers exist and give rise to de novo cardiomyocytes in the adult heart. Methods -To address this question without relying on a particular stem cell marker, we developed a new genetic lineage tracing system to label all non-myocyte populations that contain putative CSCs. Using dual lineage tracing system, we assessed if non-myocytes generated any new myocytes during embryonic development, adult homeostasis and after myocardial infarction. Skeletal muscle was also examined after injury for internal control of new myocytes generation from non-myocytes. Results -By this stem cell marker-free and dual recombinases-mediated cell tracking approach, our fate mapping data show that new myocytes arise from non-myocytes in the embryonic heart, but not in the adult heart during homeostasis or after myocardial infarction. As positive control, our lineage tracing system detected new myocytes derived from non-myocytes in the skeletal muscle after injury. Conclusions -This study provides in vivo genetic evidence for non-myocyte to myocyte conversion in embryonic but not adult heart, arguing again the myogenic potential of putative stem cell populations for cardiac regeneration in the adult stage. This study also provides a new genetic strategy to identify endogenous stem cells, if any, in other organ systems for tissue repair and regeneration.

hUTP24 is essential for processing of the human rRNA precursor at site A1, but not at site A0

PubMed Central

Tomecki, Rafal; Labno, Anna; Drazkowska, Karolina; Cysewski, Dominik; Dziembowski, Andrzej

2015-01-01

Production of ribosomes relies on more than 200 accessory factors to ensure the proper sequence of steps and faultless assembly of ribonucleoprotein machinery. Among trans-acting factors are numerous enzymes, including ribonucleases responsible for processing the large rRNA precursor synthesized by RNA polymerase I that encompasses sequences corresponding to mature 18S, 5.8S, and 25/28S rRNA. In humans, the identity of most enzymes responsible for individual processing steps, including endoribonucleases that cleave pre-rRNA at specific sites within regions flanking and separating mature rRNA, remains largely unknown. Here, we investigated the role of hUTP24 in rRNA maturation in human cells. hUTP24 is a human homolog of the Saccharomyces cerevisiae putative PIN domain-containing endoribonuclease Utp24 (yUtp24), which was suggested to participate in the U3 snoRNA-dependent processing of yeast pre-rRNA at sites A0, A1, and A2. We demonstrate that hUTP24 interacts to some extent with proteins homologous to the components of the yeast small subunit (SSU) processome. Moreover, mutation in the putative catalytic site of hUTP24 results in slowed growth of cells and reduced metabolic activity. These effects are associated with a defect in biogenesis of the 40S ribosomal subunit, which results from decreased amounts of 18S rRNA as a consequence of inaccurate pre-rRNA processing at the 5′-end of the 18S rRNA segment (site A1). Interestingly, and in contrast to yeast, site A0 located upstream of A1 is efficiently processed upon UTP24 dysfunction. Finally, hUTP24 inactivation leads to aberrant processing of 18S rRNA 2 nucleotides downstream of the normal A1 cleavage site. PMID:26237581

Characterisation of putative oxygen chemoreceptors in bowfin (Amia calva).

PubMed

Porteus, Cosima S; Wright, Patricia A; Milsom, William K

2014-04-15

Serotonin containing neuroepithelial cells (NECs) are putative oxygen sensing cells found in different locations within the gills of fish. In this study we wished to determine the effect of sustained internal (blood) hypoxaemia versus external (aquatic) hypoxia on the size and density of NECs in the first gill arch of bowfin (Amia calva), a facultative air breather. We identified five different populations of serotonergic NECs in this species (Types I-V) based on location, presence of synaptic vesicles (SV) that stain for the antibody SV2, innervation and labelling with the neural crest marker HNK-1. Cell Types I-III were innervated, and these cells, which participate in central O2 chemoreflexes, were studied further. Although there was no change in the density of any cell type in bowfin after exposure to sustained hypoxia (6.0 kPa for 7 days) without access to air, all three of these cell types increased in size. In contrast, only Type II and III cells increased in size in bowfin exposed to sustained hypoxia with access to air. These data support the suggestion that NECs are putative oxygen-sensing cells, that they occur in several locations, and that Type I cells monitor only hypoxaemia, whereas both other cell types monitor hypoxia and hypoxaemia.

Aromatic D-amino acids act as chemoattractant factors for human leukocytes through a G protein-coupled receptor, GPR109B.

PubMed

Irukayama-Tomobe, Yoko; Tanaka, Hirokazu; Yokomizo, Takehiko; Hashidate-Yoshida, Tomomi; Yanagisawa, Masashi; Sakurai, Takeshi

2009-03-10

GPR109B (HM74) is a putative G protein-coupled receptor (GPCR) whose cognate ligands have yet to be characterized. GPR109B shows a high degree of sequence similarity to GPR109A, another GPCR that was identified as a high-affinity nicotinic acid (niacin) receptor. However, the affinity of nicotinic acid to GPR109B is very low. In this study, we found that certain aromatic D-amino acids, including D-phenylalanine, D-tryptophan, and the metabolite of the latter, D-kynurenine, decreased the activity of adenylate cyclase in cells transfected with GPR109B cDNA through activation of pertussis toxin (PTX)-sensitive G proteins. These D-amino acids also elicited a transient rise of intracellular Ca(2+) level in cells expressing GPR109B in a PTX-sensitive manner. In contrast, these D-amino acids did not show any effects on cells expressing GPR109A. We found that the GPR109B mRNA is abundantly expressed in human neutrophils. D-phenylalanine and D-tryptophan induced a transient increase of intracellular Ca(2+) level and a reduction of cAMP levels in human neutrophils. Furthermore, knockdown of GPR109B by RNA interference inhibited the D-amino acids-induced decrease of cellular cAMP levels in human neutrophils. These D-amino acids induced chemotactic activity of freshly prepared human neutrophils. We also found that D-phenylalanine and D-tryptophan induced chemotactic responses in Jurkat cells transfected with the GPR109B cDNA but not in mock-transfected Jurkat cells. These results suggest that these aromatic D-amino acids elicit a chemotactic response in human neutrophils via activation of GPR109B.

Genomic Disruption of VEGF-A Expression in Human Retinal Pigment Epithelial Cells Using CRISPR-Cas9 Endonuclease.

PubMed

Yiu, Glenn; Tieu, Eric; Nguyen, Anthony T; Wong, Brittany; Smit-McBride, Zeljka

2016-10-01

To employ type II clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 endonuclease to suppress ocular angiogenesis by genomic disruption of VEGF-A in human RPE cells. CRISPR sequences targeting exon 1 of human VEGF-A were computationally identified based on predicted Cas9 on- and off-target probabilities. Single guide RNA (gRNA) cassettes with these target sequences were cloned into lentiviral vectors encoding the Streptococcuspyogenes Cas9 endonuclease (SpCas9) gene. The lentiviral vectors were used to infect ARPE-19 cells, a human RPE cell line. Frequency of insertion or deletion (indel) mutations was assessed by T7 endonuclease 1 mismatch detection assay; mRNA levels were assessed with quantitative real-time PCR; and VEGF-A protein levels were determined by ELISA. In vitro angiogenesis was measured using an endothelial cell tube formation assay. Five gRNAs targeting VEGF-A were selected based on the highest predicted on-target probabilities, lowest off-target probabilities, or combined average of both scores. Lentiviral delivery of the top-scoring gRNAs with SpCas9 resulted in indel formation in the VEGF-A gene at frequencies up to 37.0% ± 4.0% with corresponding decreases in secreted VEGF-A protein up to 41.2% ± 7.4% (P < 0.001), and reduction of endothelial tube formation up to 39.4% ± 9.8% (P = 0.02). No significant indel formation in the top three putative off-target sites tested was detected. The CRISPR-Cas9 endonuclease system may reduce VEGF-A secretion from human RPE cells and suppress angiogenesis, supporting the possibility of employing gene editing for antiangiogenesis therapy in ocular diseases.

Cystogenesis in ARPKD results from increased apoptosis in collecting duct epithelial cells of Pkhd1 mutant kidneys

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

Hu, Bo; Department of Medicine, Vanderbilt University, Nashville, TN 37232; He, Xiusheng

2011-01-15

Mutations in the PKHD1 gene result in autosomal recessive polycystic kidney disease (ARPKD) in humans. To determine the molecular mechanism of the cystogenesis in ARPKD, we recently generated a mouse model for ARPKD that carries a targeted mutation in the mouse orthologue of human PKHD1. The homozygous mutant mice display hepatorenal cysts whose phenotypes are similar to those of human ARPKD patients. By littermates of this mouse, we developed two immortalized renal collecting duct cell lines with Pkhd1 and two without. Under nonpermissive culture conditions, the Pkhd1{sup -/-} renal cells displayed aberrant cell-cell contacts and tubulomorphogenesis. The Pkhd1{sup -/-} cellsmore » also showed significantly reduced cell proliferation and elevated apoptosis. To validate this finding in vivo, we examined proliferation and apoptosis in the kidneys of Pkhd1{sup -/-} mice and their wildtype littermates. Using proliferation (PCNA and Histone-3) and apoptosis (TUNEL and caspase-3) markers, similar results were obtained in the Pkhd1{sup -/-} kidney tissues as in the cells. To identify the molecular basis of these findings, we analyzed the effect of Pkhd1 loss on multiple putative signaling regulators. We demonstrated that the loss of Pkhd1 disrupts multiple major phosphorylations of focal adhesion kinase (FAK), and these disruptions either inhibit the Ras/C-Raf pathways to suppress MEK/ERK activity and ultimately reduce cell proliferation, or suppress PDK1/AKT to upregulate Bax/caspase-9/caspase-3 and promote apoptosis. Our findings indicate that apoptosis may be a major player in the cyst formation in ARPKD, which may lead to new therapeutic strategies for human ARPKD.« less

Identification of stable reference genes in differentiating human pluripotent stem cells.

PubMed

Holmgren, Gustav; Ghosheh, Nidal; Zeng, Xianmin; Bogestål, Yalda; Sartipy, Peter; Synnergren, Jane

2015-06-01

Reference genes, often referred to as housekeeping genes (HKGs), are frequently used to normalize gene expression data based on the assumption that they are expressed at a constant level in the cells. However, several studies have shown that there may be a large variability in the gene expression levels of HKGs in various cell types. In a previous study, employing human embryonic stem cells (hESCs) subjected to spontaneous differentiation, we observed that the expression of commonly used HKG varied to a degree that rendered them inappropriate to use as reference genes under those experimental settings. Here we present a substantially extended study of the HKG signature in human pluripotent stem cells (hPSC), including nine global gene expression datasets from both hESC and human induced pluripotent stem cells, obtained during directed differentiation toward endoderm-, mesoderm-, and ectoderm derivatives. Sets of stably expressed genes were compiled, and a handful of genes (e.g., EID2, ZNF324B, CAPN10, and RABEP2) were identified as generally applicable reference genes in hPSCs across all cell lines and experimental conditions. The stability in gene expression profiles was confirmed by reverse transcription quantitative PCR analysis. Taken together, the current results suggest that differentiating hPSCs have a distinct HKG signature, which in some aspects is different from somatic cell types, and underscore the necessity to validate the stability of reference genes under the actual experimental setup used. In addition, the novel putative HKGs identified in this study can preferentially be used for normalization of gene expression data obtained from differentiating hPSCs. Copyright © 2015 the American Physiological Society.

CHL1 gene acts as a tumor suppressor in human neuroblastoma.

PubMed

Ognibene, Marzia; Pagnan, Gabriella; Marimpietri, Danilo; Cangelosi, Davide; Cilli, Michele; Benedetti, Maria Chiara; Boldrini, Renata; Garaventa, Alberto; Frassoni, Francesco; Eva, Alessandra; Varesio, Luigi; Pistoia, Vito; Pezzolo, Annalisa

2018-05-25

Neuroblastoma is an aggressive, relapse-prone childhood tumor of the sympathetic nervous system that accounts for 15% of pediatric cancer deaths. A distal portion of human chromosome 3p is often deleted in neuroblastoma, this region may contain one or more putative tumor suppressor genes. A 2.54 Mb region at 3p26.3 encompassing the smallest region of deletion pinpointed CHL1 gene, the locus for neuronal cell adhesion molecule close homolog of L1. We found that low CHL1 expression predicted poor outcome in neuroblastoma patients. Here we have used two inducible cell models to analyze the impact of CHL1 on neuroblastoma biology. Over-expression of CHL1 induced neurite-like outgrowth and markers of neuronal differentiation in neuroblastoma cells, halted tumor progression, inhibited anchorage-independent colony formation, and suppressed the growth of human tumor xenografts. Conversely, knock-down of CHL1 induced neurite retraction and activation of Rho GTPases, enhanced cell proliferation and migration, triggered colony formation and anchorage-independent growth, accelerated growth in orthotopic xenografts mouse model. Our findings demonstrate unambiguously that CHL1 acts as a regulator of proliferation and differentiation of neuroblastoma cells through inhibition of the MAPKs and Akt pathways. CHL1 is a novel candidate tumor suppressor in neuroblastoma, and its associated pathways may represent a promising target for future therapeutic interventions.

Identification, characterization and leucocyte expression of Siglec-10, a novel human sialic acid-binding receptor.

PubMed Central

Munday, J; Kerr, S; Ni, J; Cornish, A L; Zhang, J Q; Nicoll, G; Floyd, H; Mattei, M G; Moore, P; Liu, D; Crocker, P R

2001-01-01

Here we characterize Siglec-10 as a new member of the Siglec family of sialic acid-binding Ig-like lectins. A full-length cDNA was isolated from a human spleen library and the corresponding gene identified. Siglec-10 is predicted to contain five extracellular Ig-like domains and a cytoplasmic tail containing three putative tyrosine-based signalling motifs. Siglec-10 exhibited a high degree of sequence similarity to CD33-related Siglecs and mapped to the same region, on chromosome 19q13.3. The expressed protein was able to mediate sialic acid-dependent binding to human erythrocytes and soluble sialoglycoconjugates. Using specific antibodies, Siglec-10 was detected on subsets of human leucocytes including eosinophils, monocytes and a minor population of natural killer-like cells. The molecular properties and expression pattern suggest that Siglec-10 may function as an inhibitory receptor within the innate immune system. PMID:11284738

Knock down of GCN5 histone acetyltransferase by siRNA decreases ethanol-induced histone acetylation and affects differential expression of genes in human hepatoma cells.

PubMed

Choudhury, Mahua; Pandey, Ravi S; Clemens, Dahn L; Davis, Justin Wade; Lim, Robert W; Shukla, Shivendra D

2011-06-01

We have investigated whether Gcn5, a histone acetyltransferase (HAT), is involved in ethanol-induced acetylation of histone H3 at lysine 9 (H3AcK9) and has any effect on the gene expression. Human hepatoma HepG2 cells transfected with ethanol-metabolizing enzyme alcohol dehydrogenase 1 (VA 13 cells) were used. Knock down of Gcn5 by siRNA silencing decreased mRNA and protein levels of general control nondepressible 5 (GCN5), HAT activity, and also attenuated ethanol-induced H3AcK9 in VA13 cells. Illumina gene microarray analysis using total RNA showed 940 transcripts affected by GCN5 silencing or ethanol. Silencing caused differential expression of 891 transcripts (≥1.5-fold upregulated or downregulated). Among these, 492 transcripts were upregulated and 399 were downregulated compared with their respective controls. Using a more stringent threshold (≥2.5-fold), the array data from GCN5-silenced samples showed 57 genes differentially expressed (39 upregulated and 18 downregulated). Likewise, ethanol caused differential regulation of 57 transcripts with ≥1.5-fold change (35 gene upregulated and 22 downregulated). Further analysis showed that eight genes were differentially regulated that were common for both ethanol treatment and GCN5 silencing. Among these, SLC44A2 (a putative choline transporter) was strikingly upregulated by ethanol (three fold), and GCN5 silencing downregulated it (1.5-fold). The quantitative real-time polymerase chain reaction profile corroborated the array findings. This report demonstrates for the first time that (1) GCN5 differentially affects expression of multiple genes, (2) ethanol-induced histone H3-lysine 9 acetylation is mediated via GCN5, and (3) GCN5 is involved in ethanol-induced expression of the putative choline transporter SLC44A2. Copyright © 2011 Elsevier Inc. All rights reserved.

Putative melatonin receptors in a human biological clock

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

Reppert, S.M.; Weaver, D.R.; Rivkees, S.A.

In vitro autoradiography with /sup 125/I-labeled melatonin was used to examine melatonin binding sites in human hypothalamus. Specific /sup 125/I-labeled melatonin binding was localized to the suprachiasmatic nuclei, the site of a putative biological clock, and was not apparent in other hypothalamic regions. Specific /sup 125/I-labeled melatonin binding was consistently found in the suprachiasmatic nuclei of hypothalami from adults and fetuses. Densitometric analysis of competition experiments with varying concentrations of melatonin showed monophasic competition curves, with comparable half-maximal inhibition values for the suprachiasmatic nuclei of adults (150 picomolar) and fetuses (110 picomolar). Micromolar concentrations of the melatonin agonist 6-chloromelatonin completelymore » inhibited specific /sup 125/I-labeled melatonin binding, whereas the same concentrations of serotonin and norepinephrine caused only a partial reduction in specific binding. The results suggest that putative melatonin receptors are located in a human biological clock.« less

Pancreatic Cancer

PubMed Central

Maitra, Anirban; Hruban, Ralph H.

2009-01-01

The past two decades have witnessed an explosion in our understanding of pancreatic cancer, and it is now clear that pancreatic cancer is a disease of inherited (germ-line) and somatic gene mutations. The genes mutated in pancreatic cancer include KRAS2, p16/CDKN2A, TP53, and SMAD4/DPC4, and these are accompanied by a substantial compendium of genomic and transcriptomic alterations that facilitate cell cycle deregulation, cell survival, invasion, and metastases. Pancreatic cancers do not arise de novo, and three distinct precursor lesions have been identified. Experimental models of pancreatic cancer have been developed in genetically engineered mice, which recapitulate the multistep progression of the cognate human disease. Although the putative cell of origin for pancreatic cancer remains elusive, minor populations of cells with stem-like properties have been identified that appear responsible for tumor initiation, metastases, and resistance of pancreatic cancer to conventional therapies. PMID:18039136

Mammarenaviruses deleted from their Z gene are replicative and produce an infectious progeny in BHK-21 cells.

PubMed

Zaza, Amélie D; Herbreteau, Cécile H; Peyrefitte, Christophe N; Emonet, Sébastien F

2018-05-01

Mammarenaviruses bud out of infected cells via the recruitment of the endosomal sorting complex required for transport through late domain motifs localized into their Z protein. Here, we demonstrated that mammarenaviruses lacking this protein can be rescued and are replicative, despite a 3-log reduction in virion production, in BHK-21 cells, but not in five other cell lines. Mutations of putative late domain motifs identified into the viral nucleoprotein resulted in the almost complete abolition of infectious virion production by Z-deleted mammarenaviruses. This result strongly suggested that the nucleoprotein may compensate for the deletion of Z. These observations were primarily obtained using the Lymphocytic choriomeningitis virus, and further confirmed using the Old World Lassa and New World Machupo viruses, responsible of human hemorrhagic fevers. Z-deleted viruses should prove very useful tools to investigate the biology of Mammarenaviruses. Copyright © 2018 Elsevier Inc. All rights reserved.

Glucocorticoid Regulation of the Vitamin D Receptor

PubMed Central

Hidalgo, Alejandro A.; Trump, Donald L.; Johnson, Candace S.

2010-01-01

Many studies indicate calcitriol has potent anti-tumor activity in different types of cancers. However, high levels of vitamin D can produce hypercalcemia in some patients. Glucocorticoids are used to ameliorate hypercalcemia and to enhance calcitriol anti-tumor activity. Calcitriol in combination with the glucocorticoid dexamethasone (Dex) increased vitamin D receptor (VDR) protein levels and ligand binding in squamous cell carcinoma VII (SCC). In this study we found that both calcitriol and Dex induce VDR- and glucocorticoid receptor (GR)-mediated transcription respectively, indicating both hormone receptors are active in SCC. Pre-treatment with Dex increases VDR-mediated transcription at the human CYP24A1 promoter. Whereas, pre-treatment with other steroid hormones, including dihydrotestosterone and R1881, has no effect on VDR-mediated transcription. Real-time PCR indicates treatment with Dex increases Vdr transcripts in a time-dependent manner, suggesting Dex may directly regulate expression of Vdr. Numerous putative glucocorticoid response elements (GREs) were found in the Vdr gene. Chromatin immunoprecipitation (ChIP) assay demonstrated GR binding at several putative GREs located within the mouse Vdr gene. However, none of the putative GREs studied increase GR-mediated transcription in luciferase reporter assays. In an attempt to identify the response element responsible for Vdr transcript regulation, future studies will continue to analyze newly identified GREs more distal from the Vdr gene promoter. PMID:20398752

Reduced miR-433 expression is associated with advanced stages and early relapse of colorectal cancer and restored miR-433 expression suppresses the migration, invasion and proliferation of tumor cells in vitro and in nude mice.

PubMed

Zhang, Jian; Zhang, Lei; Zhang, Tong; Dong, Xin-Min; Zhu, Yu; Chen, Long-Hua

2018-05-01

The expression of microRNA (miR-433) is altered in various types of human cancer. The present study analyzed the prognostic and biological value of miR-433 expression in colorectal cancer using reverse transcription-quantitative polymerase chain reaction in 125 colorectal tissue specimens (including a test cohort of 40 cases of paired colorectal cancer and adjacent normal mucosae and a confirmation cohort of 85 cases of stage I-III colorectal cancer). In vitro and nude mouse xenograft experiments were subsequently used to assess the effects of miR-433 expression on the regulation of colorectal cancer cell proliferation, adhesion, migration, and invasion. The data indicated that miR-433 expression was significantly downregulated in colorectal cancer tissues in the test and confirmation patient cohorts and that low miR-433 expression was associated with advanced tumor stage and early relapse. Furthermore, the restoration of miR-433 expression was able to significantly inhibit the proliferation of tumor cells by inducing G1-S cell cycle arrest, suppressing cyclinD1 and CDK4 expression, and markedly inhibited the migratory and invasive capacities of tumor cells in vitro . The restoration of miR-433 expression or liposome-based delivery of miR-433 mimics suppressed the growth of colorectal cancer cell xenografts in nude mice. In conclusion, miR-433 may be a putative tumor suppressor in colorectal cancer, and the detection of low miR-433 expression will be investigated in further studies as a putative biomarker for the detection of early relapse in patients with colorectal cancer.

Differential metabolomic analysis of the potential antiproliferative mechanism of olive leaf extract on the JIMT-1 breast cancer cell line.

PubMed

Barrajón-Catalán, Enrique; Taamalli, Amani; Quirantes-Piné, Rosa; Roldan-Segura, Cristina; Arráez-Román, David; Segura-Carretero, Antonio; Micol, Vicente; Zarrouk, Mokhtar

2015-02-01

A new differential metabolomic approach has been developed to identify the phenolic cellular metabolites derived from breast cancer cells treated with a supercritical fluid extracted (SFE) olive leaf extract. The SFE extract was previously shown to have significant antiproliferative activity relative to several other olive leaf extracts examined in the same model. Upon SFE extract incubation of JIMT-1 human breast cancer cells, major metabolites were identified by using HPLC coupled to electrospray ionization quadrupole-time-of-flight mass spectrometry (ESI-Q-TOF-MS). After treatment, diosmetin was the most abundant intracellular metabolite, and it was accompanied by minor quantities of apigenin and luteolin. To identify the putative antiproliferative mechanism, the major metabolites and the complete extract were assayed for cell cycle, MAPK and PI3K proliferation pathways modulation. Incubation with only luteolin showed a significant effect in cell survival. Luteolin induced apoptosis, whereas the whole olive leaf extract incubation led to a significant cell cycle arrest at the G1 phase. The antiproliferative activity of both pure luteolin and olive leaf extract was mediated by the inactivation of the MAPK-proliferation pathway at the extracellular signal-related kinase (ERK1/2). However, the flavone concentration of the olive leaf extract did not fully explain the strong antiproliferative activity of the extract. Therefore, the effects of other compounds in the extract, probably at the membrane level, must be considered. The potential synergistic effects of the extract also deserve further attention. Our differential metabolomics approach identified the putative intracellular metabolites from a botanical extract that have antiproliferative effects, and this metabolomics approach can be expanded to other herbal extracts or pharmacological complex mixtures. Copyright © 2014 Elsevier B.V. All rights reserved.

Reduced miR-433 expression is associated with advanced stages and early relapse of colorectal cancer and restored miR-433 expression suppresses the migration, invasion and proliferation of tumor cells in vitro and in nude mice

PubMed Central

Zhang, Jian; Zhang, Lei; Zhang, Tong; Dong, Xin-Min; Zhu, Yu; Chen, Long-Hua

2018-01-01

The expression of microRNA (miR-433) is altered in various types of human cancer. The present study analyzed the prognostic and biological value of miR-433 expression in colorectal cancer using reverse transcription-quantitative polymerase chain reaction in 125 colorectal tissue specimens (including a test cohort of 40 cases of paired colorectal cancer and adjacent normal mucosae and a confirmation cohort of 85 cases of stage I–III colorectal cancer). In vitro and nude mouse xenograft experiments were subsequently used to assess the effects of miR-433 expression on the regulation of colorectal cancer cell proliferation, adhesion, migration, and invasion. The data indicated that miR-433 expression was significantly downregulated in colorectal cancer tissues in the test and confirmation patient cohorts and that low miR-433 expression was associated with advanced tumor stage and early relapse. Furthermore, the restoration of miR-433 expression was able to significantly inhibit the proliferation of tumor cells by inducing G1-S cell cycle arrest, suppressing cyclinD1 and CDK4 expression, and markedly inhibited the migratory and invasive capacities of tumor cells in vitro. The restoration of miR-433 expression or liposome-based delivery of miR-433 mimics suppressed the growth of colorectal cancer cell xenografts in nude mice. In conclusion, miR-433 may be a putative tumor suppressor in colorectal cancer, and the detection of low miR-433 expression will be investigated in further studies as a putative biomarker for the detection of early relapse in patients with colorectal cancer. PMID:29740483

Insights into the TOR-S6K signaling pathway in maize (Zea mays L.). pathway activation by effector-receptor interaction.

PubMed

Garrocho-Villegas, Verónica; Aguilar C, Raúl; Sánchez de Jiménez, Estela

2013-12-23

The primordial TOR pathway, known to control growth and cell proliferation, has still not been fully described for plants. Nevertheless, in maize, an insulin-like growth factor (ZmIGF) peptide has been reported to stimulate this pathway. This research provides further insight into the TOR pathway in maize, using a biochemical approach in cultures of fast-growing (FG) and slow-growing (SG) calli, as a model system. Our results revealed that addition of either ZmIGF or insulin to SG calli stimulated DNA synthesis and increased the growth rate through cell proliferation and increased the rate of ribosomal protein (RP) synthesis by the selective mobilization of RP mRNAs into polysomes. Furthermore, analysis of the phosphorylation status of the main TOR and S6K kinases from the TOR pathway revealed stimulation by ZmIGF or insulin, whereas rapamycin inhibited its activation. Remarkably, a putative maize insulin-like receptor was recognized by a human insulin receptor antibody, as demonstrated by immunoprecipitation from membrane protein extracts of maize callus. Furthermore, competition experiments between ZmIGF and insulin for the receptor site on maize protoplasts suggested structural recognition of the putative receptor by either effector. These data were confirmed by confocal immunolocalization within the cell membrane of callus cells. Taken together, these data indicate that cell growth and cell proliferation in maize depend on the activation of the TOR-S6K pathway through the interaction of an insulin-like growth factor and its receptor. This evidence suggests that higher plants as well as metazoans have conserved this biochemical pathway to regulate their growth, supporting the conclusion that it is a highly evolved conserved pathway.

Portal inflammation during NAFLD is frequent and associated with the early phases of putative hepatic progenitor cell activation.

PubMed

Carotti, Simone; Vespasiani-Gentilucci, Umberto; Perrone, Giuseppe; Picardi, Antonio; Morini, Sergio

2015-11-01

We investigated whether portal tract inflammation observed in non-alcoholic fatty liver disease (NAFLD) is associated with hepatic progenitor cell compartment activation, as thoroughly evaluated with different markers of the staminal lineage. Fifty-two patients with NAFLD were studied. NAFLD activity score, fibrosis and portal inflammation were histologically evaluated. Putative hepatic progenitor cells, intermediate hepatobiliary cells and bile ductules/interlobular bile ducts were evaluated by immunohistochemistry for cytokeratin (CK)-7, CK-19 and epithelial cell adhesion molecule (EpCAM), and a hepatic progenitor cell compartment score was derived. Hepatic stellate cell and myofibroblast activity was determined by immunohistochemistry for α-smooth muscle actin. Portal inflammation was absent in a minority of patients, mild in 40% of cases and more than mild in about half of patients, showing a strong correlation with fibrosis (r=0.76, p<0.001). Portal inflammation correlated with CK-7-counted putative hepatic progenitor cells (r=0.48, p<0.001), intermediate hepatobiliary cells (r=0.6, p<0.001) and bile ductules/interlobular bile ducts (r=0.6, p<0.001), and with the activity of myofibroblasts (r=0.5, p<0.001). Correlations were confirmed when elements were counted by immunostaining for CK-19 and EpCAM. Lobular inflammation, ballooning, myofibroblast activity and hepatic progenitor cell compartment activation were associated with portal inflammation by univariate analysis. In the multivariate model, the only variable independently associated with portal inflammation was hepatic progenitor cell compartment activation (OR 3.7, 95% CI 1.1 to 12.6). Portal inflammation is frequent during NAFLD and strongly associated with activation of putative hepatic progenitor cells since the first steps of their differentiation, portal myofibroblast activity and fibrosis. 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.

Novel Regenerative Therapies Based on Regionally Induced Multipotent Stem Cells in Post-Stroke Brains: Their Origin, Characterization, and Perspective.

PubMed

Takagi, Toshinori; Yoshimura, Shinichi; Sakuma, Rika; Nakano-Doi, Akiko; Matsuyama, Tomohiro; Nakagomi, Takayuki

2017-12-01

Brain injuries such as ischemic stroke cause severe neural loss. Until recently, it was believed that post-ischemic areas mainly contain necrotic tissue and inflammatory cells. However, using a mouse model of cerebral infarction, we demonstrated that stem cells develop within ischemic areas. Ischemia-induced stem cells can function as neural progenitors; thus, we initially named them injury/ischemia-induced neural stem/progenitor cells (iNSPCs). However, because they differentiate into more than neural lineages, we now refer to them as ischemia-induced multipotent stem cells (iSCs). Very recently, we showed that putative iNSPCs/iSCs are present within post-stroke areas in human brains. Because iNSPCs/iSCs isolated from mouse and human ischemic tissues can differentiate into neuronal lineages in vitro, it is possible that a clearer understanding of iNSPC/iSC profiles and the molecules that regulate iNSPC/iSC fate (e.g., proliferation, differentiation, and survival) would make it possible to perform neural regeneration/repair in patients following stroke. In this article, we introduce the origin and traits of iNSPCs/iSCs based on our reports and recent viewpoints. We also discuss their possible contribution to neurogenesis through endogenous and exogenous iNSPC/iSC therapies following ischemic stroke.

Human endometrial matrix metalloproteinase-2, a putative menstrual proteinase. Hormonal regulation in cultured stromal cells and messenger RNA expression during the menstrual cycle.

PubMed Central

Irwin, J C; Kirk, D; Gwatkin, R B; Navre, M; Cannon, P; Giudice, L C

1996-01-01

Proteinases are likely effectors of endometrial menstrual breakdown. We have investigated proteinase production by human endometrial stromal cells subjected in vitro to progesterone (P) withdrawal, the physiologic stimulus for menstruation. Culture media of cells exposed to estradiol, P, or estradiol plus P had low levels of proteolytic activity similar to cultures maintained in the absence of steroids. P withdrawal, or addition of RU486 to P-treated cultures, stimulated proteinase secretion. The stromal cell proteinase was characterized by gelatin zymography, inhibitor profile, and organomercurial activation, as a metalloproteinase present mostly as a 66-kD proenzyme with lower levels of a 62-kD active form. The P withdrawal-induced metalloproteinase was identified as matrix metalloproteinase-2 (MMP-2) by Western blotting. The increase of MMP-2 induced by P withdrawal was associated with the metalloproteinase-dependent breakdown of stromal cultures, involving dissolution of extracellular matrix and dissociation of stromal cells. Northern analysis showed the differential expression of MMP-2 mRNA in late secretory phase endometrium. These findings are consistent with the involvement of stromal cell-derived MMP-2 in the proteolysis of extracellular matrix promoting cyclic endometrial breakdown and the onset of menstrual bleeding. PMID:8567965

Updates in the Development of ImmunoRNases for the Selective Killing of Tumor Cells.

PubMed

Jordaan, Sandra; Akinrinmade, Olusiji A; Nachreiner, Thomas; Cremer, Christian; Naran, Krupa; Chetty, Shivan; Barth, Stefan

2018-03-05

Targeted cancer therapy includes, amongst others, antibody-based delivery of toxic payloads to selectively eliminate tumor cells. This payload can be either a synthetic small molecule drug composing an antibody-drug conjugate (ADC) or a cytotoxic protein composing an immunotoxin (IT). Non-human cytotoxic proteins, while potent, have limited clinical efficacy due to their immunogenicity and potential off-target toxicity. Humanization of the cytotoxic payload is essential and requires harnessing of potent apoptosis-inducing human proteins with conditional activity, which rely on targeted delivery to contact their substrate. Ribonucleases are attractive candidates, due to their ability to induce apoptosis by abrogating protein biosynthesis via tRNA degradation. In fact, several RNases of the pancreatic RNase A superfamily have shown potential as anti-cancer agents. Coupling of a human RNase to a humanized antibody or antibody derivative putatively eliminates the immunogenicity of an IT (now known as a human cytolytic fusion protein, hCFP). However, RNases are tightly regulated in vivo by endogenous inhibitors, controlling the ribonucleolytic balance subject to the cell's metabolic requirements. Endogenous inhibition limits the efficacy with which RNase-based hCFPs induce apoptosis. However, abrogating the natural interaction with the natural inhibitors by mutation has been shown to significantly enhance RNase activity, paving the way toward achieving cytolytic potency comparable to that of bacterial immunotoxins. Here, we review the immunoRNases that have undergone preclinical studies as anti-cancer therapeutic agents.

Ku80 Counters Oxidative Stress-Induced DNA Damage and Cataract Formation in the Human Lens.

PubMed

Smith, Andrew John Oliver; Ball, Simon Sidney Robert; Manzar, Kamal; Bowater, Richard Peter; Wormstone, Ian Michael

2015-12-01

Oxidative stress in the human lens leads to a wide range of damage including DNA strand breaks, which are likely to contribute to cataract formation. The protein Ku80 is a fundamental component of the nonhomologous end-joining pathway that repairs DNA double strand breaks. This study investigates the putative impact of Ku80 in cataract prevention in the human lens. The present study used the human lens epithelial cell line FHL124 and whole human lens organ culture. Targeted siRNA was used to deplete Ku80, with Western blot and immunocytochemistry employed to assess Ku80 expression levels. Oxidative stress was induced with hydrogen peroxide and DNA strand breaks measured by alkaline comet assay and γH2AX foci counts. Visual quality of whole human lenses was measured with image analysis software. Expression of Ku80 was predominately found in the cell nucleus of both FHL124 cells and native human lens epithelium. Treatment of FHL124 cells and whole lens cultures with siRNA targeted against Ku80 resulted in a significant knockdown at the protein level. Application of oxidative stress (30 μM H2O2) created more DNA strand breaks when added to Ku80 knockdown cells than in scrambled siRNA control cells as determined by the alkaline comet assay and the number of γH2AX foci. In whole lens cultures, exposure to 1 mM H2O2 resulted in more lens opacity in Ku80 knockdown lenses than match-paired controls. Depletion of Ku80 in the lens through acute change or a consequence of aging is likely to increase levels of DNA strand breaks, which could negatively influence physiological function and promote lens opacity. It is therefore feasible that Ku80 plays a role in retarding cataract formation.

Suitability of human Tenon's fibroblasts as feeder cells for culturing human limbal epithelial stem cells.

PubMed

Scafetta, Gaia; Tricoli, Eleonora; Siciliano, Camilla; Napoletano, Chiara; Puca, Rosa; Vingolo, Enzo Maria; Cavallaro, Giuseppe; Polistena, Andrea; Frati, Giacomo; De Falco, Elena

2013-12-01

Corneal epithelial regeneration through ex vivo expansion of limbal stem cells (LSCs) on 3T3-J2 fibroblasts has revealed some limitations mainly due to the corneal microenvironment not being properly replicated, thus affecting long term results. Insights into the feeder cells that are used to expand LSCs and the mechanisms underlying the effects of human feeder cells have yet to be fully elucidated. We recently developed a standardized methodology to expand human Tenon's fibroblasts (TFs). Here we aimed to investigate whether TFs can be employed as feeder cells for LSCs, characterizing the phenotype of the co-cultures and assessing what human soluble factors are secreted. The hypothesis that TFs could be employed as alternative human feeder layer has not been explored yet. LSCs were isolated from superior limbus biopsies, co-cultured on TFs, 3T3-J2 or dermal fibroblasts (DFs), then analyzed by immunofluorescence (p63α), colony-forming efficiency (CFE) assay and qPCR for a panel of putative stem cell and epithelial corneal differentiation markers (KRT3). Co-cultures supernatants were screened for a set of soluble factors. Results showed that the percentage of p63α(+)LSCs co-cultured onto TFs was significantly higher than those on DFs (p = 0.032) and 3T3-J2 (p = 0.047). Interestingly, LSCs co-cultures on TFs exhibited both significantly higher CFE and mRNA expression levels of ΔNp63α than on 3T3-J2 and DFs (p < 0.0001), showing also significantly greater levels of soluble factors (IL-6, HGF, b-FGF, G-CSF, TGF-β3) than LSCs on DFs. Therefore, TFs could represent an alternative feeder layer to both 3T3-J2 and DFs, potentially providing a suitable microenvironment for LSCs culture.

Changes in tumor cell heterogeneity after chemotherapy treatment in a xenograft model of glioblastoma.

PubMed

Welker, Alessandra M; Jaros, Brian D; An, Min; Beattie, Christine E

2017-07-25

Glioblastoma (GBM) is a highly aggressive brain cancer with limited treatments and poor patient survival. GBM tumors are heterogeneous containing a complex mixture of dividing cells, differentiated cells, and cancer stem cells. It is unclear, however, how these different cell populations contribute to tumor growth or whether they exhibit differential responses to chemotherapy. Here we set out to address these questions using a zebrafish xenograft transplant model (Welker et al., 2016). We found that a small population of differentiated vimentin-positive tumor cells, but a majority of Sox2-positive putative cancer stem cells, were dividing during tumor growth. We also observed co-expression of Sox2 and GFAP, another suggested marker of glioma cancer stem cells, indicating that the putative cancer stem cells in GBM9 tumors expressed both of these markers. To determine how these different tumor cell populations responded to chemotherapy, we treated animals with temozolomide (TMZ) and assessed these cell populations immediately after treatment and 5 and 10days after treatment cessation. As expected we found a significant decrease in dividing cells after treatment. We also found a significant decrease in vimentin-positive cells, but not in Sox2 or GFAP-positive cells. However, the Sox2-positive cells significantly increased 5days after TMZ treatment. These data support that putative glioma cancer stem cells are more resistant to TMZ treatment and may contribute to tumor regrowth after chemotherapy. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

Primary Human Placental Trophoblasts are Permissive for Zika Virus (ZIKV) Replication.

PubMed

Aagaard, Kjersti M; Lahon, Anismrita; Suter, Melissa A; Arya, Ravi P; Seferovic, Maxim D; Vogt, Megan B; Hu, Min; Stossi, Fabio; Mancini, Michael A; Harris, R Alan; Kahr, Maike; Eppes, Catherine; Rac, Martha; Belfort, Michael A; Park, Chun Shik; Lacorazza, Daniel; Rico-Hesse, Rebecca

2017-01-27

Zika virus (ZIKV) is an emerging mosquito-borne (Aedes genus) arbovirus of the Flaviviridae family. Although ZIKV has been predominately associated with a mild or asymptomatic dengue-like disease, its appearance in the Americas has been accompanied by a multi-fold increase in reported incidence of fetal microcephaly and brain malformations. The source and mode of vertical transmission from mother to fetus is presumptively transplacental, although a causal link explaining the interval delay between maternal symptoms and observed fetal malformations following infection has been missing. In this study, we show that primary human placental trophoblasts from non-exposed donors (n = 20) can be infected by primary passage ZIKV-FLR isolate, and uniquely allowed for ZIKV viral RNA replication when compared to dengue virus (DENV). Consistent with their being permissive for ZIKV infection, primary trophoblasts expressed multiple putative ZIKV cell entry receptors, and cellular function and differentiation were preserved. These findings suggest that ZIKV-FLR strain can replicate in human placental trophoblasts without host cell destruction, thereby serving as a likely permissive reservoir and portal of fetal transmission with risk of latent microcephaly and malformations.

A Molecular Sensor To Characterize Arenavirus Envelope Glycoprotein Cleavage by Subtilisin Kexin Isozyme 1/Site 1 Protease.

PubMed

Oppliger, Joel; da Palma, Joel Ramos; Burri, Dominique J; Bergeron, Eric; Khatib, Abdel-Majid; Spiropoulou, Christina F; Pasquato, Antonella; Kunz, Stefan

2016-01-15

Arenaviruses are emerging viruses including several causative agents of severe hemorrhagic fevers in humans. The advent of next-generation sequencing technology has greatly accelerated the discovery of novel arenavirus species. However, for many of these viruses, only genetic information is available, and their zoonotic disease potential remains unknown. During the arenavirus life cycle, processing of the viral envelope glycoprotein precursor (GPC) by the cellular subtilisin kexin isozyme 1 (SKI-1)/site 1 protease (S1P) is crucial for productive infection. The ability of newly emerging arenaviruses to hijack human SKI-1/S1P appears, therefore, to be a requirement for efficient zoonotic transmission and human disease potential. Here we implement a newly developed cell-based molecular sensor for SKI-1/S1P to characterize the processing of arenavirus GPC-derived target sequences by human SKI-1/S1P in a quantitative manner. We show that only nine amino acids flanking the putative cleavage site are necessary and sufficient to accurately recapitulate the efficiency and subcellular location of arenavirus GPC processing. In a proof of concept, our sensor correctly predicts efficient processing of the GPC of the newly emergent pathogenic Lujo virus by human SKI-1/S1P and defines the exact cleavage site. Lastly, we employed our sensor to show efficient GPC processing of a panel of pathogenic and nonpathogenic New World arenaviruses, suggesting that GPC cleavage represents no barrier for zoonotic transmission of these pathogens. Our SKI-1/S1P sensor thus represents a rapid and robust test system for assessment of the processing of putative cleavage sites derived from the GPCs of newly discovered arenavirus by the SKI-1/S1P of humans or any other species, based solely on sequence information. Arenaviruses are important emerging human pathogens that can cause severe hemorrhagic fevers with high mortality in humans. A crucial step in productive arenavirus infection of human cells is the processing of the viral envelope glycoprotein by the cellular subtilisin kexin isozyme 1 (SKI-1)/site 1 protease (S1P). In order to break the species barrier during zoonotic transmission and cause severe disease in humans, newly emerging arenaviruses must be able to hijack human SKI-1/S1P efficiently. Here we implement a newly developed cell-based molecular sensor for human SKI-1/S1P to characterize the processing of arenavirus glycoproteins in a quantitative manner. We further use our sensor to correctly predict efficient processing of the glycoprotein of the newly emergent pathogenic Lujo virus by human SKI-1/S1P. Our sensor thus represents a rapid and robust test system with which to assess whether the glycoprotein of any newly emerging arenavirus can be efficiently processed by human SKI-1/S1P, based solely on sequence information. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

PRE-CLINICAL EVALUATION OF EXTRACTS AND ESSENTIAL OILS FROM BETEL-LIKE SCENT PIPER SPECIES IDENTIFIED POTENTIAL CANCER TREATMENT

PubMed Central

Sanubol, Arisa; Chaveerach, Arunrat; Tanee, Tawatchai; Sudmoon, Runglawan

2017-01-01

Background: Nine Piper species with betel-like scents are sources of industrial and medicinal aromatic chemicals, but there is lack of information on cytotoxicity and genotoxicity for human safety, including how these plants impact human cervical cancer cell line. Methods: Plant leaves were extracted with hexane and hydro-distilled for essential oils. The extracts and oils were pre-clinically studied based on cyto - and genotoxicity using microculture tetrazolium (MTT) and comet assays. Results: The crude extracts showed an IC50 in leukocytes and HeLa cells of 58.59-97.31 mg/ml and 34.91-101.79 mg/ml, the LD50 is higher than 5000 mg/kg. With lower values than the crude extracts, the essential oils showed an IC50 in leukocytes and HeLa cells of 0.023-0.059 μg/ml and 0.025-0.043 μg/ml the LD50 is less than 50 mg/kg. IC50 values showed that the essential oils were highly toxic than the crude extracts. At the level of human genetic materials, the crude extracts of two species, including P. betloides and P. crocatum, showed a significant toxicity (p < 0.05) in leukocytes. The other samples were non-toxic. The crude extracts of all samples showed significant genotoxicity in HeLa cells. The essential oils of all studied Piper species showed insignificant toxicity in leukocytes. For HeLa cells, the eight-studied species showed significant toxicity in HeLa cells, whereas only P. submultinerve showed insignificant toxicity. Conclusion: The crude extracts and essential oils should be tested as putative cervical cancer treatments due to less toxicity in human normal cells. PMID:28480386

PRE-CLINICAL EVALUATION OF EXTRACTS AND ESSENTIAL OILS FROM BETEL-LIKE SCENT PIPER SPECIES IDENTIFIED POTENTIAL CANCER TREATMENT.

PubMed

Sanubol, Arisa; Chaveerach, Arunrat; Tanee, Tawatchai; Sudmoon, Runglawan

2017-01-01

Nine Piper species with betel-like scents are sources of industrial and medicinal aromatic chemicals, but there is lack of information on cytotoxicity and genotoxicity for human safety, including how these plants impact human cervical cancer cell line. Plant leaves were extracted with hexane and hydro-distilled for essential oils. The extracts and oils were pre-clinically studied based on cyto - and genotoxicity using microculture tetrazolium (MTT) and comet assays. The crude extracts showed an IC 50 in leukocytes and HeLa cells of 58.59-97.31 mg/ml and 34.91-101.79 mg/ml, the LD 50 is higher than 5000 mg/kg. With lower values than the crude extracts, the essential oils showed an IC 50 in leukocytes and HeLa cells of 0.023-0.059 μg/ml and 0.025-0.043 μg/ml the LD 50 is less than 50 mg/kg. IC 50 values showed that the essential oils were highly toxic than the crude extracts. At the level of human genetic materials, the crude extracts of two species, including P. betloides and P. crocatum , showed a significant toxicity ( p < 0.05) in leukocytes. The other samples were non-toxic. The crude extracts of all samples showed significant genotoxicity in HeLa cells. The essential oils of all studied Piper species showed insignificant toxicity in leukocytes. For HeLa cells, the eight-studied species showed significant toxicity in HeLa cells, whereas only P. submultinerve showed insignificant toxicity. The crude extracts and essential oils should be tested as putative cervical cancer treatments due to less toxicity in human normal cells.

Adult pituitary stem cells: from pituitary plasticity to adenoma development.

PubMed

Florio, Tullio

2011-01-01

The pituitary needs high plasticity of the hormone-producing cell compartment to generate the continuously changing hormonal signals that govern the key physiological processes it is involved in, as well as homeostatic cell turnover. However, the underlying mechanisms are still poorly understood. It was proposed that adult stem cells direct the generation of newborn cells with a hormonal phenotype according to the physiological requirements. However, only in recent years adult pituitary stem cells have begun to be phenotypically characterized in several studies that identified multiple stem/progenitor cell candidates. Also considering the incompletely defined features of this cell subpopulation, some discrepancies among the different reports are clearly apparent and long-term self-renewal remains to be unequivocally demonstrated. Here, all the recently published evidence is analyzed, trying, when possible, to reconcile the results of the different studies. Finally, with the perspective of shedding light on pituitary tumorigenesis and the development of potentially new pharmacological approaches directed against these cells, very recent evidence on the presence of putative cancer stem cells in human pituitary adenomas is discussed. Copyright © 2011 S. Karger AG, Basel.

CD86 expression as a surrogate cellular biomarker for pharmacological inhibition of the histone demethylase lysine-specific demethylase 1.

PubMed

Lynch, James T; Cockerill, Mark J; Hitchin, James R; Wiseman, Daniel H; Somervaille, Tim C P

2013-11-01

There is a lack of rapid cell-based assays that read out enzymatic inhibition of the histone demethylase LSD1 (lysine-specific demethylase 1). Through transcriptome analysis of human acute myeloid leukemia THP1 cells treated with a tranylcypromine-derivative inhibitor of LSD1 active in the low nanomolar range, we identified the cell surface marker CD86 as a sensitive surrogate biomarker of LSD1 inhibition. Within 24h of enzyme inhibition, there was substantial and dose-dependent up-regulation of CD86 expression, as detected by quantitative polymerase chain reaction, flow cytometry, and enzyme-linked immunosorbent assay. Thus, the use of CD86 expression may facilitate screening of compounds with putative LSD1 inhibitory activities in cellular assays. Copyright © 2013 Elsevier Inc. All rights reserved.

The life span-prolonging effect of sirtuin-1 is mediated by autophagy.

PubMed

Morselli, Eugenia; Maiuri, Maria Chiara; Markaki, Maria; Megalou, Evgenia; Pasparaki, Angela; Palikaras, Konstantinos; Criollo, Alfredo; Galluzzi, Lorenzo; Malik, Shoaib Ahmad; Vitale, Ilio; Michaud, Mickael; Madeo, Frank; Tavernarakis, Nektarios; Kroemer, Guido

2010-01-01

The life span of various model organisms can be extended by caloric restriction as well as by autophagy-inducing pharmacological agents. Life span-prolonging effects have also been observed in yeast cells, nematodes and flies upon the overexpression of the deacetylase Sirtuin-1. Intrigued by these observations and by the established link between caloric restriction and Sirtuin-1 activation, we decided to investigate the putative implication of Sirtuin-1 in the response of human cancer cells and Caenorhabditis elegans to multiple triggers of autophagy. Our data indicate that the activation of Sirtuin-1 (by the pharmacological agent resveratrol and/or genetic means) per se ignites autophagy, and that Sirtuin-1 is required for the autophagic response to nutrient deprivation, in both human and nematode cells, but not for autophagy triggered by downstream signals such as the inhibition of mTOR or p53. Since the life spanextending effects of Sirtuin-1 activators are lost in autophagy-deficient C. elegans, our results suggest that caloric restriction and resveratrol extend longevity, at least in experimental settings, by activating autophagy.

Biosynthesis of highly enriched 13C-lycopene for human metabolic studies using repeated batch tomato cell culturing with 13C-glucose

PubMed Central

Moran, Nancy E.; Rogers, Randy B.; Lu, Chi-Hua; Conlon, Lauren E.; Lila, Mary Ann; Clinton, Steven K.; Erdman, John W.

2013-01-01

While putative disease-preventing lycopene metabolites are found in both tomato (Solanum lycopersicum) products and in their consumers, mammalian lycopene metabolism is poorly understood. Advances in tomato cell culturing techniques offer an economical tool for generation of highly-enriched 13C-lycopene for human bioavailability and metabolism studies. To enhance the 13C-enrichment and yields of labeled lycopene from the hp-1 tomato cell line, cultures were first grown in 13C-glucose media for three serial batches and produced increasing proportions of uniformly labeled lycopene (14.3 +/− 1.2 %, 39.6 +/− 0.5 %, and 48.9 +/− 1.5% with consistent yields (from 5.8 to 9 mg/L). An optimized 9-day-long 13C-loading and 18-day-long labeling strategy developed based on glucose utilization and lycopene yields, yielded 13C-lycopene with 93% 13C isotopic purity, and 55% of isotopomers were uniformly labeled. Furthermore, an optimized acetone and hexane extraction led to a four-fold increase in lycopene recovery from cultures compared to a standard extraction. PMID:23561155

The hppA gene of Helicobacter pylori encodes the class C acid phosphatase precursor.

PubMed

Godlewska, Renata; Bujnicki, Janusz M; Ostrowski, Jerzy; Jagusztyn-Krynicka, Elzbieta K

2002-08-14

Screening of the Helicobacter pylori genomic library with sera from infected humans and from immunized rabbits resulted in identification of the 25 kDa protein cell envelope (HppA) which exhibits acid phosphatase activity. Enzyme activity was demonstrated by specific enzymatic assays with whole-cell protein preparations of H. pylori strain N6 and from Escherichia coli carrying the hppA gene (pUWM192). HppA showed optimum activity at pH 5.6 and was resistant to inhibition by EDTA. Bioinformatics analysis and site-directed mutagenesis of two putative active site residues (D73 and D192) provide further insight into the sequence-structure-function relationships of HppA as a member of the DDDD phosphohydrolase superfamily.

Molecular cloning and identification of the transcriptional regulatory domain of the goat neurokinin B gene TAC3.

PubMed

Suetomi, Yuta; Matsuda, Fuko; Uenoyama, Yoshihisa; Maeda, Kei-ichiro; Tsukamura, Hiroko; Ohkura, Satoshi

2013-10-01

Neurokinin B (NKB), encoded by TAC3, is thought to be an important accelerator of pulsatile gonadotropin-releasing hormone release. This study aimed to clarify the transcriptional regulatory mechanism of goat TAC3. First, we determined the full-length mRNA sequence of goat TAC3 from the hypothalamus to be 820 b, including a 381 b coding region, with the putative transcription start site located 143-b upstream of the start codon. The deduced amino acid sequence of NKB, which is produced from preproNKB, was completely conserved among goat, cattle, and human. Next, we cloned 5'-upstream region of goat TAC3 up to 3400 b from the translation initiation site, and this region was highly homologous with cattle TAC3 (89%). We used this goat TAC3 5'-upstream region to perform luciferase assays. We created a luciferase reporter vector containing DNA constructs from -2706, -1837, -834, -335, or -197 to +166 bp (the putative transcription start site was designated as +1) of goat TAC3 and these were transiently transfected into mouse hypothalamus-derived N7 cells and human neuroblastoma-derived SK-N-AS cells. The luciferase activity gradually increased with the deletion of the 5'-upstream region, suggesting that the transcriptional suppressive region is located between -2706 and -336 bp and that the core promoter exists downstream of -197 bp. Estradiol treatment did not lead to significant suppression of luciferase activity of any constructs, suggesting the existence of other factor(s) that regulate goat TAC3 transcription.

Human adenovirus serotypes 4p and 11p are efficiently expressed in cell lines of neural tumour origin.

PubMed

Skog, Johan; Mei, Ya-Fang; Wadell, Göran

2002-06-01

Most currently used adenovirus vectors are based upon adenovirus serotypes 2 and 5 (Ad2 and Ad5), which have limited efficiencies for gene transfer to human neural cells. Both serotypes bind to the known adenovirus receptor, CAR (coxsackievirus and adenovirus receptor), and have restricted cell tropism. The purpose of this study was to find vector candidates that are superior to Ad5 in infecting human neural tumours. Using flow cytometry, the vector candidates Ad4p, Ad11p and Ad17p were compared to the commonly used adenovirus vector Ad5v for their binding capacity to neural cell lines derived from glioblastoma, medulloblastoma and neuroblastoma cell lines. The production of viral structural proteins and the CAR-binding properties of the different serotypes were also assessed in these cells. Computer-based models of the fibre knobs of Ad4p and Ad17 were created based upon the crystallized fibre knob structure of adenoviruses and analysed for putative receptor-interacting regions that differed from the fibre knob of Ad5. The non CAR-binding vector candidate Ad11p showed clearly the best binding capacity to all of the neural cell lines, binding more than 90% of cells of all of the neural cell lines tested, in contrast to 20% or less for the commonly used vector Ad5v. Ad4p and Ad11p were also internalized and produced viral proteins more successfully than Ad5. Ad4p showed a low binding ability but a very efficient capacity for infection in cell culture. Ad17p virions neither bound or efficiently infected any of the neural cell lines studied.

Identification of the bombesin receptor on murine and human cells by cross-linking experiments.

PubMed

Kris, R M; Hazan, R; Villines, J; Moody, T W; Schlessinger, J

1987-08-15

The bombesin receptor present on the surface of murine and human cells was identified using 125I-labeled gastrin-releasing peptide as a probe, the cross-linking agent disuccinimidyl suberate, and sodium dodecyl sulfate gels. A clone of NIH-3T3 cells which possesses approximately 80,000 bombesin receptors/cell with a single binding constant of approximately 1.9 X 10(-9) M was used in these studies. In addition, we used Swiss 3T3 cells and a human glioma cell line which possesses approximately 100,000 and approximately 55,000 bombesin receptors/cell, respectively. Under conditions found optimal for binding, it is demonstrated that 125I-labeled gastrin-releasing peptide can be cross-linked specifically to a glycoprotein of apparent molecular mass of 65,000 daltons on the surface of the NIH-3T3 cells. Similar results were obtained when the cross-linked product was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis under reducing or non-reducing conditions. Moreover, the cross-linking reaction is specific and saturable and the 65,000-dalton polypeptide is not observed when the cross-linking experiments were performed with a NIH-3T3 cell line which is devoid of bombesin receptors. Interestingly, glycoproteins with apparent molecular weights of 75,000 were labeled specifically by 125I-labeled gastrin-releasing peptide when similar experiments were performed with Swiss 3T3 cells and with human glioma cell line GM-340. These different molecular weights may indicate differential glycosylation as treatment with the enzyme N-glycanase reduced the apparent molecular weight of the cross-linked polypeptide to 45,000. On the basis of these results it is concluded that the cross-linked polypeptides represent the bombesin receptor or the ligand-binding subunit of a putative larger bombesin receptor expressed on the surface of these cells.

Identification of a CYP3A form (CYP3A126) in fathead minnow (Pimephales promelas) and characterisation of putative CYP3A enzyme activity.

PubMed

Christen, Verena; Caminada, Daniel; Arand, Michael; Fent, Karl

2010-01-01

Cytochrome P450-dependent monooxygenases (CYPs) are involved in the metabolic defence against xenobiotics. Human CYP3A enzymes metabolise about 50% of all pharmaceuticals in use today. Induction of CYPs and associated xenobiotic metabolism occurs also in fish and may serve as a useful tool for biomonitoring of environmental contamination. In this study we report on the cloning of a CYP3A family gene from fathead minnows (Pimephales promelas), which has been designated as CYP3A126 by the P450 nomenclature committee (GenBank no. EU332792). The cDNA was isolated, identified and characterised by extended inverse polymerase chain reaction (PCR), an alternative to the commonly used method of rapid amplification of cDNA ends. In a fathead minnow cell line we identified a full-length cDNA sequence (1,863 base pairs (bp)) consisting of a 1,536 bp open reading frame encoding a 512 amino acid protein. Genomic analysis of the identified CYP3A isoenzyme revealed a DNA sequence consisting of 13 exons and 12 introns. CYP3A126 is also expressed in fathead minnow liver as demonstrated by reverse transcription PCR. Exposure of fathead minnow (FHM) cells with the CYP3A inducer rifampicin leads to dose-dependent increase in putative CYP3A enzyme activity. In contrast, inhibitory effects of diazepam treatment were observed on putative CYP3A enzyme activity and additionally on CYP3A126 mRNA expression. This indicates that CYP3A is active in FHM cells and that CYP3A126 is at least in part responsible for this CYP3A activity. Further investigations will show whether CYP3A126 is involved in the metabolism of environmental chemicals.

Homozygous ARHGEF2 mutation causes intellectual disability and midbrain-hindbrain malformation.

PubMed

Ravindran, Ethiraj; Hu, Hao; Yuzwa, Scott A; Hernandez-Miranda, Luis R; Kraemer, Nadine; Ninnemann, Olaf; Musante, Luciana; Boltshauser, Eugen; Schindler, Detlev; Hübner, Angela; Reinecker, Hans-Christian; Ropers, Hans-Hilger; Birchmeier, Carmen; Miller, Freda D; Wienker, Thomas F; Hübner, Christoph; Kaindl, Angela M

2017-04-01

Mid-hindbrain malformations can occur during embryogenesis through a disturbance of transient and localized gene expression patterns within these distinct brain structures. Rho guanine nucleotide exchange factor (ARHGEF) family members are key for controlling the spatiotemporal activation of Rho GTPase, to modulate cytoskeleton dynamics, cell division, and cell migration. We identified, by means of whole exome sequencing, a homozygous frameshift mutation in the ARHGEF2 as a cause of intellectual disability, a midbrain-hindbrain malformation, and mild microcephaly in a consanguineous pedigree of Kurdish-Turkish descent. We show that loss of ARHGEF2 perturbs progenitor cell differentiation and that this is associated with a shift of mitotic spindle plane orientation, putatively favoring more symmetric divisions. The ARHGEF2 mutation leads to reduction in the activation of the RhoA/ROCK/MLC pathway crucial for cell migration. We demonstrate that the human brain malformation is recapitulated in Arhgef2 mutant mice and identify an aberrant migration of distinct components of the precerebellar system as a pathomechanism underlying the midbrain-hindbrain phenotype. Our results highlight the crucial function of ARHGEF2 in human brain development and identify a mutation in ARHGEF2 as novel cause of a neurodevelopmental disorder.

Homozygous ARHGEF2 mutation causes intellectual disability and midbrain-hindbrain malformation

PubMed Central

Yuzwa, Scott A.; Hernandez-Miranda, Luis R.; Musante, Luciana; Boltshauser, Eugen; Schindler, Detlev; Hübner, Angela; Reinecker, Hans-Christian; Ropers, Hans-Hilger; Miller, Freda D.; Hübner, Christoph; Kaindl, Angela M.

2017-01-01

Mid-hindbrain malformations can occur during embryogenesis through a disturbance of transient and localized gene expression patterns within these distinct brain structures. Rho guanine nucleotide exchange factor (ARHGEF) family members are key for controlling the spatiotemporal activation of Rho GTPase, to modulate cytoskeleton dynamics, cell division, and cell migration. We identified, by means of whole exome sequencing, a homozygous frameshift mutation in the ARHGEF2 as a cause of intellectual disability, a midbrain-hindbrain malformation, and mild microcephaly in a consanguineous pedigree of Kurdish-Turkish descent. We show that loss of ARHGEF2 perturbs progenitor cell differentiation and that this is associated with a shift of mitotic spindle plane orientation, putatively favoring more symmetric divisions. The ARHGEF2 mutation leads to reduction in the activation of the RhoA/ROCK/MLC pathway crucial for cell migration. We demonstrate that the human brain malformation is recapitulated in Arhgef2 mutant mice and identify an aberrant migration of distinct components of the precerebellar system as a pathomechanism underlying the midbrain-hindbrain phenotype. Our results highlight the crucial function of ARHGEF2 in human brain development and identify a mutation in ARHGEF2 as novel cause of a neurodevelopmental disorder. PMID:28453519

Characterization of a candidate bcl-1 gene.

PubMed Central

Withers, D A; Harvey, R C; Faust, J B; Melnyk, O; Carey, K; Meeker, T C

1991-01-01

The t(11;14)(q13;q32) translocation has been associated with human B-lymphocytic malignancy. Several examples of this translocation have been cloned, documenting that this abnormality joins the immunoglobulin heavy-chain gene to the bcl-1 locus on chromosome 11. However, the identification of the bcl-1 gene, a putative dominant oncogene, has been elusive. In this work, we have isolated genomic clones covering 120 kb of the bcl-1 locus. Probes from the region of an HpaII-tiny-fragment island identified a candidate bcl-1 gene. cDNAs representing the bcl-1 mRNA were cloned from three cell lines, two with the translocation. The deduced amino acid sequence from these clones showed bcl-1 to be a member of the cyclin gene family. In addition, our analysis of expression of bcl-1 in an extensive panel of human cell lines showed it to be widely expressed except in lymphoid or myeloid lineages. This observation may provide a molecular basis for distinct modes of cell cycle control in different mammalian tissues. Activation of the bcl-1 gene may be oncogenic by directly altering progression through the cell cycle. Images PMID:1833629

Structural analysis of the 5{prime} region of mouse and human Huntington disease genes reveals conservation of putative promoter region and Di- and trinucleotide polymorphisms

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

Lin, Biaoyang; Nasir, J.; Kalchman, M.A.

1995-02-10

We have previously cloned and characterized the murine homologue of the Huntington disease (HD) gene and shown that it maps to mouse chromosome 5 within a region of conserved synteny with human chromosome 4p16.3. Here we present a detailed comparison of the sequence of the putative promoter and the organization of the 5{prime} genomic region of the murine (Hdh) and human HD genes encompassing the first five exons. We show that in this region these two genes share identical exon boundaries, but have different-size introns. Two dinucleotide (CT) and one trinucleotide intronic polymorphism in Hdh and an intronic CA polymorphismmore » in the HD gene were identified. Comparison of 940-bp sequence 5{prime} to the putative translation start site reveals a highly conserved region (78.8% nucleotide identity) between Hdh and the HD gene from nucleotide -56 to -206 (of Hdh). Neither Hdh nor the HD gene have typical TATA or CCAAT elements, but both show one putative AP2 binding site and numerous potential Sp1 binding sites. The high sequence identity between Hdh and the HD gene for approximately 200 bp 5{prime} to the putative translation start site indicates that these sequences may play a role in regulating expression of the Huntington disease gene. 30 refs., 4 figs., 2 tabs.« less

Regulatory T-cells in autoimmune diseases: challenges, controversies and--yet--unanswered questions.

PubMed

Grant, Charlotte R; Liberal, Rodrigo; Mieli-Vergani, Giorgina; Vergani, Diego; Longhi, Maria Serena

2015-02-01

Regulatory T cells (Tregs) are central to the maintenance of self-tolerance and tissue homeostasis. Markers commonly used to define human Tregs in the research setting include high expression of CD25, FOXP3 positivity and low expression/negativity for CD127. Many other markers have been proposed, but none unequivocally identifies bona fide Tregs. Tregs are equipped with an array of mechanisms of suppression, including the modulation of antigen presenting cell maturation and function, the killing of target cells, the disruption of metabolic pathways and the production of anti-inflammatory cytokines. Treg impairment has been reported in a number of human autoimmune conditions and includes Treg numerical and functional defects and conversion into effector cells in response to inflammation. In addition to intrinsic Treg impairment, resistance of effector T cells to Treg control has been described. Discrepancies in the literature are common, reflecting differences in the choice of study participants and the technical challenges associated with investigating this cell population. Studies differ in terms of the methodology used to define and isolate putative regulatory cells and to assess their suppressive function. In this review we outline studies describing Treg frequency and suppressive function in systemic and organ specific autoimmune diseases, with a specific focus on the challenges faced when investigating Tregs in these conditions. Copyright © 2014 Elsevier B.V. All rights reserved.

The putative oncotarget CSN5 controls a transcription-uncorrelated p53-mediated autophagy implicated in cancer cell survival under curcumin treatment.

PubMed

Zhang, Qing-Yu; Jin, Rui; Zhang, Xian; Sheng, Ji-Po; Yu, Fang; Tan, Ren-Xiang; Pan, Ying; Huang, Jun-Jian; Kong, Ling-Dong

2016-10-25

Curcumin has shown promise as a safe and specific anticancer agent. The COP9 signalosome (CSN) component CSN5, a known specific target for curcumin, can control p53 stability by increasing its degradation through ubiquitin system. But the correlation of CSN5-controlled p53 to anticancer therapeutic effect of curcumin is currently unknown. Here we showed that CSN5-controlled p53 was transcriptional inactive and responsible for autophagy in human normal BJ cells and cancer HepG2 cells under curcumin treatment. Of note, CSN5-initiated cellular autophagy by curcumin treatment was abolished in p53-null HCT116p53-/- cancer cells, which could be rescued by reconstitution with wild-type p53 or transcription inactive p53 mutant p53R273H. Furthermore, CSN5-controlled p53 conferred a pro-survival autophagy in diverse cancer cells response to curcumin. Genetic p53 deletion, as well as autophagy pharmacological inhibition by chloroquine, significantly enhanced the therapeutic effect of curcumin on cancer cells in vitro and in vivo, but not normal cells. This study identifies a novel CSN5-controlled p53 in autophagy of human cells. The p53 expression state is a useful biomarker for predicting the anticancer therapeutic effect of curcumin. Therefore, the pharmacologic autophagy manipulation may benefit the ongoing anticancer clinical trials of curcumin.

Hybrid clone cells derived from human breast epithelial cells and human breast cancer cells exhibit properties of cancer stem/initiating cells.

PubMed

Gauck, Daria; Keil, Silvia; Niggemann, Bernd; Zänker, Kurt S; Dittmar, Thomas

2017-08-02

The biological phenomenon of cell fusion has been associated with cancer progression since it was determined that normal cell × tumor cell fusion-derived hybrid cells could exhibit novel properties, such as enhanced metastatogenic capacity or increased drug resistance, and even as a mechanism that could give rise to cancer stem/initiating cells (CS/ICs). CS/ICs have been proposed as cancer cells that exhibit stem cell properties, including the ability to (re)initiate tumor growth. Five M13HS hybrid clone cells, which originated from spontaneous cell fusion events between M13SV1-EGFP-Neo human breast epithelial cells and HS578T-Hyg human breast cancer cells, and their parental cells were analyzed for expression of stemness and EMT-related marker proteins by Western blot analysis and confocal laser scanning microscopy. The frequency of ALDH1-positive cells was determined by flow cytometry using AldeRed fluorescent dye. Concurrently, the cells' colony forming capabilities as well as the cells' abilities to form mammospheres were investigated. The migratory activity of the cells was analyzed using a 3D collagen matrix migration assay. M13HS hybrid clone cells co-expressed SOX9, SLUG, CK8 and CK14, which were differently expressed in parental cells. A variation in the ALDH1-positive putative stem cell population was observed among the five hybrids ranging from 1.44% (M13HS-7) to 13.68% (M13HS-2). In comparison to the parental cells, all five hybrid clone cells possessed increased but also unique colony formation and mammosphere formation capabilities. M13HS-4 hybrid clone cells exhibited the highest colony formation capacity and second highest mammosphere formation capacity of all hybrids, whereby the mean diameter of the mammospheres was comparable to the parental cells. In contrast, the largest mammospheres originated from the M13HS-2 hybrid clone cells, whereas these cells' mammosphere formation capacity was comparable to the parental breast cancer cells. All M13HS hybrid clones exhibited a mesenchymal phenotype and, with the exception of one hybrid clone, responded to EGF with an increased migratory activity. Fusion of human breast epithelial cells and human breast cancer cells can give rise to hybrid clone cells that possess certain CS/IC properties, suggesting that cell fusion might be a mechanism underlying how tumor cells exhibiting a CS/IC phenotype could originate.

PPARγ regulates exocrine pancreas lipase.

PubMed

Danino, Hila; Naor, Ronny Peri-; Fogel, Chen; Ben-Harosh, Yael; Kadir, Rotem; Salem, Hagit; Birk, Ruth

2016-12-01

Pancreatic lipase (triacylglycerol lipase EC 3.1.1.3) is an essential enzyme in hydrolysis of dietary fat. Dietary fat, especially polyunsaturated fatty acids (PUFA), regulate pancreatic lipase (PNLIP); however, the molecular mechanism underlying this regulation is mostly unknown. As PUFA are known to regulate expression of proliferator-activated receptor gamma (PPARγ), and as we identified in-silico putative PPARγ binding sites within the putative PNLIP promoter sequence, we hypothesized that PUFA regulation of PNLIP might be mediated by PPARγ. We used in silico bioinformatics tools, reporter luciferase assay, PPARγ agonists and antagonists, PPARγ overexpression in exocrine pancreas AR42J and primary cells to study PPARγ regulation of PNLIP. Using in silico bioinformatics tools we mapped PPARγ binding sites (PPRE) to the putative promoter region of PNLIP. Reporter luciferase assay in AR42J rat exocrine pancreas acinar cells transfected with various constructs of the putative PNLIP promoter showed that PNLIP transcription is significantly enhanced by PPARγ dose-dependently, reaching maximal levels with multi PPRE sites. This effect was significantly augmented in the presence of PPARγ agonists and reduced by PPARγ antagonists or mutagenesis abrogating PPRE sites. Over-expression of PPARγ significantly elevated PNLIP transcript and protein levels in AR42J cells and in primary pancreas cells. Moreover, PNLIP expression was up-regulated by PPARγ agonists (pioglitazone and 15dPGJ2) and significantly down-regulated by PPARγ antagonists in non-transfected rat exocrine pancreas AR42J cell line cells. PPARγ transcriptionally regulates PNLIP gene expression. This transcript regulation resolves part of the missing link between dietary PUFA direct regulation of PNLIP. Copyright © 2016 Elsevier B.V. All rights reserved.

A Novel Role of Silibinin as a Putative Epigenetic Modulator in Human Prostate Carcinoma.

PubMed

Anestopoulos, Ioannis; Sfakianos, Aristeidis P; Franco, Rodrigo; Chlichlia, Katerina; Panayiotidis, Mihalis I; Kroll, David J; Pappa, Aglaia

2016-12-31

Silibinin, extracted from milk thistle ( Silybum marianum L.), has exhibited considerable preclinical activity against prostate carcinoma. Its antitumor and chemopreventive activities have been associated with diverse effects on cell cycle, apoptosis, and receptor-dependent mitogenic signaling pathways. Here we hypothesized that silibinin's pleiotropic effects may reflect its interference with epigenetic mechanisms in human prostate cancer cells. More specifically, we have demonstrated that silibinin reduces gene expression levels of the Polycomb Repressive Complex 2 (PRC2) members Enhancer of Zeste Homolog 2 (EZH2), Suppressor of Zeste Homolog 12 (SUZ12), and Embryonic Ectoderm Development (EED) in DU145 and PC3 human prostate cancer cells, as evidenced by Real Time Polymerase Chain Reaction (RT-PCR). Furthermore immunoblot and immunofluorescence analysis revealed that silibinin-mediated reduction of EZH2 levels was accompanied by an increase in trimethylation of histone H3 on lysine (Κ)-27 residue (H3K27me3) levels and that such response was, in part, dependent on decreased expression levels of phosphorylated Akt (ser473) (pAkt) and phosphorylated EZH2 (ser21) (pEZH2). Additionally silibinin exerted other epigenetic effects involving an increase in total DNA methyltransferase (DNMT) activity while it decreased histone deacetylases 1-2 (HDACs1-2) expression levels. We conclude that silibinin induces epigenetic alterations in human prostate cancer cells, suggesting that subsequent disruptions of central processes in chromatin conformation may account for some of its diverse anticancer effects.

Cigarette smoke increases Staphylococcus aureus biofilm formation via oxidative stress.

PubMed

Kulkarni, Ritwij; Antala, Swati; Wang, Alice; Amaral, Fábio E; Rampersaud, Ryan; Larussa, Samuel J; Planet, Paul J; Ratner, Adam J

2012-11-01

The strong epidemiological association between cigarette smoke (CS) exposure and respiratory tract infections is conventionally attributed to immunosuppressive and irritant effects of CS on human cells. Since pathogenic bacteria such as Staphylococcus aureus are members of the normal microbiota and reside in close proximity to human nasopharyngeal cells, we hypothesized that bioactive components of CS might affect these organisms and potentiate their virulence. Using Staphylococcus aureus as a model organism, we observed that the presence of CS increased both biofilm formation and host cell adherence. Analysis of putative molecular pathways revealed that CS exposure decreased expression of the quorum-sensing agr system, which is involved in biofilm dispersal, and increased transcription of biofilm inducers such as sarA and rbf. CS contains bioactive compounds, including free radicals and reactive oxygen species, and we observed transcriptional induction of bacterial oxidoreductases, including superoxide dismutase, following exposure. Moreover, pretreatment of CS with an antioxidant abrogated CS-mediated enhancement of biofilms. Exposure of bacteria to hydrogen peroxide alone increased biofilm formation. These observations are consistent with the hypothesis that CS induces staphylococcal biofilm formation in an oxidant-dependent manner. CS treatment induced transcription of fnbA (encoding fibronectin binding protein A), leading to increased binding of CS-treated staphylococci to immobilized fibronectin and increased adherence to human cells. These observations indicate that the bioactive effects of CS may extend to the resident microbiota of the nasopharynx, with implications for the pathogenesis of respiratory infection in CS-exposed humans.

Functional high-resolution time-course expression analysis of human embryonic stem cells undergoing cardiac induction.

PubMed

Piccini, Ilaria; Araúzo-Bravo, Marcos; Seebohm, Guiscard; Greber, Boris

2016-12-01

Cardiac induction of human embryonic stem cells (hESCs) is a process bearing increasing medical relevance, yet it is poorly understood from a developmental biology perspective. Anticipated technological progress in deriving stably expandable cardiac precursor cells or in advancing cardiac subtype specification protocols will likely require deeper insights into this fascinating system. Recent improvements in controlling hESC differentiation now enable a near-homogeneous induction of the cardiac lineage. This is based on an optimized initial stimulation of mesoderm-inducing signaling pathways such as Activin and/or FGF, BMP, and WNT, followed by WNT inhibition as a secondary requirement. Here, we describe a comprehensive data set based on varying hESC differentiation conditions in a systematic manner and recording high-resolution differentiation time-courses analyzed by genome-wide expression profiling (GEO accession number GSE67154). As a baseline, hESCs were differentiated into cardiomyocytes under optimal conditions. Moreover, in additional time-series, individual signaling factors were withdrawn from the initial stimulation cocktail to reveal their specific roles via comparison to the standard condition. Hence, this data set presents a rich resource for hypothesis generation in studying human cardiac induction, as we reveal numbers of known as well as uncharacterized genes prominently marking distinct intermediate stages in the process. These data will also be useful for identifying putative cardiac master regulators in the human system as well as for characterizing expandable cardiac stem cells.

Dacarbazine-mediated upregulation of NKG2D ligands on tumor cells activates NK and CD8 T cells and restrains melanoma growth.

PubMed

Hervieu, Alice; Rébé, Cédric; Végran, Frédérique; Chalmin, Fanny; Bruchard, Mélanie; Vabres, Pierre; Apetoh, Lionel; Ghiringhelli, François; Mignot, Grégoire

2013-02-01

Dacarbazine (DTIC) is a cytotoxic drug widely used for melanoma treatment. However, the putative contribution of anticancer immune responses in the efficacy of DTIC has not been evaluated. By testing how DTIC affects host immune responses to cancer in a mouse model of melanoma, we unexpectedly found that both natural killer (NK) and CD8(+) T cells were indispensable for DTIC therapeutic effect. Although DTIC did not directly affect immune cells, it triggered the upregulation of NKG2D ligands on tumor cells, leading to NK cell activation and IFNγ secretion in mice and humans. NK cell-derived IFNγ subsequently favored upregulation of major histocompatibility complex class I molecules on tumor cells, rendering them sensitive to cytotoxic CD8(+) T cells. Accordingly, DTIC markedly enhanced cytotoxic T lymphocyte antigen 4 inhibition efficacy in vivo in an NK-dependent manner. These results underscore the immunogenic properties of DTIC and provide a rationale to combine DTIC with immunotherapeutic agents that relieve immunosuppression in vivo.

Identification of a novel putative pancreatic stem/progenitor cell marker DCAMKL-1 in normal mouse pancreas.

PubMed

May, Randal; Sureban, Sripathi M; Lightfoot, Stan A; Hoskins, Aimee B; Brackett, Daniel J; Postier, Russell G; Ramanujam, Rama; Rao, Chinthalapally V; Wyche, James H; Anant, Shrikant; Houchen, Courtney W

2010-08-01

Stem cells are critical in maintaining adult homeostasis and have been proposed to be the origin of many solid tumors, including pancreatic cancer. Here we demonstrate the expression patterns of the putative intestinal stem cell marker DCAMKL-1 in the pancreas of uninjured C57BL/6 mice compared with other pancreatic stem/progenitor cell markers. We then determined the viability of isolated pancreatic stem/progenitor cells in isotransplantation assays following DCAMKL-1 antibody-based cell sorting. Sorted cells were grown in suspension culture and injected into the flanks of athymic nude mice. Here we report that DCAMKL-1 is expressed in the main pancreatic duct epithelia and islets, but not within acinar cells. Coexpression was observed with somatostatin, NGN3, and nestin, but not glucagon or insulin. Isolated DCAMKL-1+ cells formed spheroids in suspension culture and induced nodule formation in isotransplantation assays. Analysis of nodules demonstrated markers of early pancreatic development (PDX-1), glandular epithelium (cytokeratin-14 and Ep-CAM), and isletlike structures (somatostatin and secretin). These data taken together suggest that DCAMKL-1 is a novel putative stem/progenitor marker, can be used to isolate normal pancreatic stem/progenitors, and potentially regenerates pancreatic tissues. This may represent a novel tool for regenerative medicine and a target for anti-stem cell-based therapeutics in pancreatic cancer.

Identification of a novel putative pancreatic stem/progenitor cell marker DCAMKL-1 in normal mouse pancreas

PubMed Central

May, Randal; Sureban, Sripathi M.; Lightfoot, Stan A.; Hoskins, Aimee B.; Brackett, Daniel J.; Postier, Russell G.; Ramanujam, Rama; Rao, Chinthalapally V.; Wyche, James H.; Anant, Shrikant

2010-01-01

Stem cells are critical in maintaining adult homeostasis and have been proposed to be the origin of many solid tumors, including pancreatic cancer. Here we demonstrate the expression patterns of the putative intestinal stem cell marker DCAMKL-1 in the pancreas of uninjured C57BL/6 mice compared with other pancreatic stem/progenitor cell markers. We then determined the viability of isolated pancreatic stem/progenitor cells in isotransplantation assays following DCAMKL-1 antibody-based cell sorting. Sorted cells were grown in suspension culture and injected into the flanks of athymic nude mice. Here we report that DCAMKL-1 is expressed in the main pancreatic duct epithelia and islets, but not within acinar cells. Coexpression was observed with somatostatin, NGN3, and nestin, but not glucagon or insulin. Isolated DCAMKL-1+ cells formed spheroids in suspension culture and induced nodule formation in isotransplantation assays. Analysis of nodules demonstrated markers of early pancreatic development (PDX-1), glandular epithelium (cytokeratin-14 and Ep-CAM), and isletlike structures (somatostatin and secretin). These data taken together suggest that DCAMKL-1 is a novel putative stem/progenitor marker, can be used to isolate normal pancreatic stem/progenitors, and potentially regenerates pancreatic tissues. This may represent a novel tool for regenerative medicine and a target for anti-stem cell-based therapeutics in pancreatic cancer. PMID:20522640

MicroRNA-23b mediates urokinase and c-met downmodulation and a decreased migration of human hepatocellular carcinoma cells.

PubMed

Salvi, Alessandro; Sabelli, Cristiano; Moncini, Silvia; Venturin, Marco; Arici, Bruna; Riva, Paola; Portolani, Nazario; Giulini, Stefano M; De Petro, Giuseppina; Barlati, Sergio

2009-06-01

Urokinase-type plasminogen activator (uPA) and c-met play a major role in cancer invasion and metastasis. Evidence has suggested that uPA and c-met overexpression may be coordinated in human hepatocellular carcinoma (HCC). In the present study, to understand whether the expression of these genes might be coregulated by specific microRNAs (miRs) in human cells, we predicted that Homo sapiens microRNA-23b could recognize two sites in the 3'-UTR of uPA and four sites in the c-met 3'-UTR by the algorithm pictar. The miR-23b expression analysis in human tumor and normal cells revealed an inverse trend with uPA and c-met expression, indicating that uPA and c-met negative regulation might depend on miR-23b expression. Transfection of miR-23b molecules in HCC cells (SKHep1C3) led to inhibition of protein expression of the target genes and caused a decrease in cell migration and proliferation capabilities. Furthermore, anti-miR-23b transfection in human normal AB2 dermal fibroblasts upregulated the expression of endogenous uPA and c-met. Cotransfection experiments in HCC cells of the miR-23b with pGL4.71 Renilla luciferase reporter gene constructs, containing the putative uPA and c-met 3'-UTR target sites, and with the pGL3 firefly luciferase-expressing vector showed a decrease in the relative luciferase activity. This would indicate that miR-23b can recognize target sites in the 3'-UTR of uPA and of c-met mRNAs and translationally repress the expression of uPA and c-met in HCC cells. The evidence obtained shows that overexpression of miR-23b leads to uPA and c-met downregulation and to decreased migration and proliferation abilities of HCC cells.

Orally Administered Salacia reticulata Extract Reduces H1N1 Influenza Clinical Symptoms in Murine Lung Tissues Putatively Due to Enhanced Natural Killer Cell Activity

PubMed Central

Romero-Pérez, Gustavo A.; Egashira, Masayo; Harada, Yuri; Tsuruta, Takeshi; Oda, Yuriko; Ueda, Fumitaka; Tsukahara, Takamitsu; Tsukamoto, Yasuhiro; Inoue, Ryo

2016-01-01

Influenza is a major cause of respiratory tract infection. Although most cases do not require further hospitalization, influenza periodically causes epidemics in humans that can potentially infect and kill millions of people. To countermeasure this threat, new vaccines need to be developed annually to match emerging influenza viral strains with increased resistance to existing vaccines. Thus, there is a need for finding and developing new anti-influenza viral agents as alternatives to current treatments. Here, we tested the antiviral effects of an extract from the stems and roots of Salacia reticulata (SSRE), a plant rich in phytochemicals, such as salacinol, kotalanol, and catechins, on H1N1 influenza virus-infected mice. Following oral administration of 0.6 mg/day of SSRE, the incidence of coughing decreased in 80% of mice, and only one case of severe pulmonary inflammation was detected. Moreover, when compared with mice given Lactobacillus casei JCM1134, a strain previously shown to help increase in vitro natural killer (NK) cell activity, SSRE-administered mice showed greater and equal NK cell activity in splenocytes and pulmonary cells, respectively, at high effector cell:target cell ratios. Next, to test whether or not SSRE would exert protective effects against influenza in the absence of gut microbiota, mice were given antibiotics before being inoculated influenza virus and subsequently administered SSRE. SSRE administration induced an increase in NK cell activity in splenocytes and pulmonary cells at levels similar to those detected in mice not treated with antibiotics. Based on our results, it can be concluded that phytochemicals in the SSRE exerted protective effects against influenza infection putatively via modulation of the immune response, including enhancement of NK cell activity, although some protective effects were not necessarily through modulation of gut microbiota. Further investigation is necessary to elucidate the molecular mechanisms underlying the protective effects of SSRE against influenza infection. PMID:27066007

A Catalogue of Putative cis-Regulatory Interactions Between Long Non-coding RNAs and Proximal Coding Genes Based on Correlative Analysis Across Diverse Human Tumors.

PubMed

Basu, Swaraj; Larsson, Erik

2018-05-31

Antisense transcripts and other long non-coding RNAs are pervasive in mammalian cells, and some of these molecules have been proposed to regulate proximal protein-coding genes in cis For example, non-coding transcription can contribute to inactivation of tumor suppressor genes in cancer, and antisense transcripts have been implicated in the epigenetic inactivation of imprinted genes. However, our knowledge is still limited and more such regulatory interactions likely await discovery. Here, we make use of available gene expression data from a large compendium of human tumors to generate hypotheses regarding non-coding-to-coding cis -regulatory relationships with emphasis on negative associations, as these are less likely to arise for reasons other than cis -regulation. We document a large number of possible regulatory interactions, including 193 coding/non-coding pairs that show expression patterns compatible with negative cis -regulation. Importantly, by this approach we capture several known cases, and many of the involved coding genes have known roles in cancer. Our study provides a large catalog of putative non-coding/coding cis -regulatory pairs that may serve as a basis for further experimental validation and characterization. Copyright © 2018 Basu and Larsson.

Stability and function of a putative microtubule-organizing center in the human parasite Toxoplasma gondii

PubMed Central

Leung, Jacqueline M.; He, Yudou; Zhang, Fangliang; Hwang, Yu-Chen; Nagayasu, Eiji; Liu, Jun; Murray, John M.; Hu, Ke

2017-01-01

The organization of the microtubule cytoskeleton is dictated by microtubule nucleators or organizing centers. Toxoplasma gondii, an important human parasite, has an array of 22 regularly spaced cortical microtubules stemming from a hypothesized organizing center, the apical polar ring. Here we examine the functions of the apical polar ring by characterizing two of its components, KinesinA and APR1, and show that its putative role in templating can be separated from its mechanical stability. Parasites that lack both KinesinA and APR1 (ΔkinesinAΔapr1) are capable of generating 22 cortical microtubules. However, the apical polar ring is fragmented in live ΔkinesinAΔapr1 parasites and is undetectable by electron microscopy after detergent extraction. Disintegration of the apical polar ring results in the detachment of groups of microtubules from the apical end of the parasite. These structural defects are linked to a diminished ability of the parasite to move and invade host cells, as well as decreased secretion of effectors important for these processes. Together the findings demonstrate the importance of the structural integrity of the apical polar ring and the microtubule array in the Toxoplasma lytic cycle, which is responsible for massive tissue destruction in acute toxoplasmosis. PMID:28331073

Chaperonin-containing T-complex Protein 1 Subunit ζ Serves as an Autoantigen Recognized by Human Vδ2 γδ T Cells in Autoimmune Diseases.

PubMed

Chen, Hui; You, Hongqin; Wang, Lifang; Zhang, Xuan; Zhang, Jianmin; He, Wei

2016-09-16

Human γδ T cells recognize conserved endogenous and stress-induced antigens typically associated with autoimmune diseases. However, the role of γδ T cells in autoimmune diseases is not clear. Few autoimmune disease-related antigens recognized by T cell receptor (TCR) γδ have been defined. In this study, we compared Vδ2 TCR complementarity-determining region 3 (CDR3) between systemic lupus erythematosus (SLE) patients and healthy donors. Results show that CDR3 length distribution differed significantly and displayed oligoclonal characteristics in SLE patients when compared with healthy donors. We found no difference in the frequency of Jδ gene fragment usage between these two groups. According to the dominant CDR3δ sequences in SLE patients, synthesized SL2 peptides specifically bound to human renal proximal tubular epithelial cell line HK-2; SL2-Vm, a mutant V sequence of SL2, did not bind. We identified the putative protein ligand chaperonin-containing T-complex protein 1 subunit ζ (CCT6A) using SL2 as a probe in HK-2 cell protein extracts by affinity chromatography and liquid chromatography-electrospray ionization-tandem mass spectrometry analysis. We found CCT6A expression on the surface of HK-2 cells. Cytotoxicity of only Vδ2 γδ T cells to HK-2 cells was blocked by anti-CCT6A antibody. Finally, we note that CCT6A concentration was significantly increased in plasma of SLE and rheumatoid arthritis patients. These data suggest that CCT6A is a novel autoantigen recognized by Vδ2 γδ T cells, which deepens our understanding of mechanisms in autoimmune diseases. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

DNA from Porphyromonas gingivalis and Tannerella forsythia induce cytokine production in human monocytic cell lines.

PubMed

Sahingur, S E; Xia, X-J; Alamgir, S; Honma, K; Sharma, A; Schenkein, H A

2010-04-01

Toll-like receptor 9 (TLR9) expression is increased in periodontally diseased tissues compared with healthy sites indicating a possible role of TLR9 and its ligand, bacterial DNA (bDNA), in periodontal disease pathology. Here, we determine the immunostimulatory effects of periodontal bDNA in human monocytic cells (THP-1). THP-1 cells were stimulated with DNA of two putative periodontal pathogens: Porphyromonas gingivalis and Tannerella forsythia. The role of TLR9 in periodontal bDNA-initiated cytokine production was determined either by blocking TLR9 signaling in THP-1 cells with chloroquine or by measuring IL-8 production and nuclear factor-kappaB (NF-kappaB) activation in HEK293 cells stably transfected with human TLR9. Cytokine production (IL-1beta, IL-6, and TNF-alpha) was increased significantly in bDNA-stimulated cells compared with controls. Chloroquine treatment of THP-1 cells decreased cytokine production, suggesting that TLR9-mediated signaling pathways are operant in the recognition of DNA from periodontal pathogens. Compared with native HEK293 cells, TLR9-transfected cells demonstrated significantly increased IL-8 production (P < 0.001) and NF-kappaB activation in response to bDNA, further confirming the role of TLR9 in periodontal bDNA recognition. The results of PCR arrays demonstrated upregulation of proinflammatory cytokine and NF-kappaB genes in response to periodontal bDNA in THP-1 cells, suggesting that cytokine induction is through NF-kappaB activation. Hence, immune responses triggered by periodontal bacterial nucleic acids may contribute to periodontal disease pathology by inducing proinflammatory cytokine production through the TLR9 signaling pathway.

Differentiation of V2a interneurons from human pluripotent stem cells

PubMed Central

Butts, Jessica C.; McCreedy, Dylan A.; Martinez-Vargas, Jorge Alexis; Mendoza-Camacho, Frederico N.; Hookway, Tracy A.; Gifford, Casey A.; Taneja, Praveen; Noble-Haeusslein, Linda; McDevitt, Todd C.

2017-01-01

The spinal cord consists of multiple neuronal cell types that are critical to motor control and arise from distinct progenitor domains in the developing neural tube. Excitatory V2a interneurons in particular are an integral component of central pattern generators that control respiration and locomotion; however, the lack of a robust source of human V2a interneurons limits the ability to molecularly profile these cells and examine their therapeutic potential to treat spinal cord injury (SCI). Here, we report the directed differentiation of CHX10+ V2a interneurons from human pluripotent stem cells (hPSCs). Signaling pathways (retinoic acid, sonic hedgehog, and Notch) that pattern the neural tube were sequentially perturbed to identify an optimized combination of small molecules that yielded ∼25% CHX10+ cells in four hPSC lines. Differentiated cultures expressed much higher levels of V2a phenotypic markers (CHX10 and SOX14) than other neural lineage markers. Over time, CHX10+ cells expressed neuronal markers [neurofilament, NeuN, and vesicular glutamate transporter 2 (VGlut2)], and cultures exhibited increased action potential frequency. Single-cell RNAseq analysis confirmed CHX10+ cells within the differentiated population, which consisted primarily of neurons with some glial and neural progenitor cells. At 2 wk after transplantation into the spinal cord of mice, hPSC-derived V2a cultures survived at the site of injection, coexpressed NeuN and VGlut2, extended neurites >5 mm, and formed putative synapses with host neurons. These results provide a description of V2a interneurons differentiated from hPSCs that may be used to model central nervous system development and serve as a potential cell therapy for SCI. PMID:28438991

Berberine-induced Inactivation of Signal Transducer and Activator of Transcription 5 Signaling Promotes Male-specific Expression of a Bile Acid Uptake Transporter*

PubMed Central

Bu, Pengli; Le, Yuan; Zhang, Yue; Zhang, Youcai; Cheng, Xingguo

2017-01-01

Sodium-taurocholate co-transporting polypeptide (Ntcp/NTCP) is the major uptake transporter of bile salts in mouse and human livers. In certain diseases, including endotoxemia, cholestasis, diabetes, and hepatocarcinoma, Ntcp/NTCP expression is markedly reduced, which interferes with enterohepatic circulation of bile salts, impairing the absorption of lipophilic compounds. Therefore, normal Ntcp/NTCP expression in the liver is physiologically important. Berberine is an herbal medicine used historically to improve liver function and has recently been shown to repress STAT signaling. However, berberine effects on Ntcp/NTCP expression are unknown, prompting use to investigate this possible connection. Our results showed that berberine dose-dependently increased Ntcp expression in male mouse liver and decreased taurocholic acid levels in serum but increased them in the liver. In mouse and human hepatoma cells, berberine induced Ntcp/NTCP mRNA and protein expression and increased cellular uptake of [3H] taurocholate. Mechanistically, berberine decreased nuclear protein levels of phospho-JAK2 and phospho-STAT5, thus disrupting the JAK2-STAT5 signaling. Moreover, berberine stimulated luciferase reporter expression from the mouse Ntcp promoter when one putative STAT5 response element (RE) (−1137 bp) was deleted and from the human NTCP promoter when three putative STAT5REs (−2898, −2164, and −691 bp) were deleted. Chromatin immunoprecipitation demonstrated that berberine decreased binding of phospho-STAT5 protein to the−2164 and −691 bp STAT5REs in the human NTCP promoter. In summary, berberine-disrupted STAT5 signaling promoted mouse and human Ntcp/NTCP expression, resulting in enhanced bile acid uptake. Therefore, berberine may be a therapeutic candidate compound for maintaining bile acid homeostasis. PMID:28154180

Large-scale interaction profiling of PDZ domains through proteomic peptide-phage display using human and viral phage peptidomes.

PubMed

Ivarsson, Ylva; Arnold, Roland; McLaughlin, Megan; Nim, Satra; Joshi, Rakesh; Ray, Debashish; Liu, Bernard; Teyra, Joan; Pawson, Tony; Moffat, Jason; Li, Shawn Shun-Cheng; Sidhu, Sachdev S; Kim, Philip M

2014-02-18

The human proteome contains a plethora of short linear motifs (SLiMs) that serve as binding interfaces for modular protein domains. Such interactions are crucial for signaling and other cellular processes, but are difficult to detect because of their low to moderate affinities. Here we developed a dedicated approach, proteomic peptide-phage display (ProP-PD), to identify domain-SLiM interactions. Specifically, we generated phage libraries containing all human and viral C-terminal peptides using custom oligonucleotide microarrays. With these libraries we screened the nine PSD-95/Dlg/ZO-1 (PDZ) domains of human Densin-180, Erbin, Scribble, and Disks large homolog 1 for peptide ligands. We identified several known and putative interactions potentially relevant to cellular signaling pathways and confirmed interactions between full-length Scribble and the target proteins β-PIX, plakophilin-4, and guanylate cyclase soluble subunit α-2 using colocalization and coimmunoprecipitation experiments. The affinities of recombinant Scribble PDZ domains and the synthetic peptides representing the C termini of these proteins were in the 1- to 40-μM range. Furthermore, we identified several well-established host-virus protein-protein interactions, and confirmed that PDZ domains of Scribble interact with the C terminus of Tax-1 of human T-cell leukemia virus with micromolar affinity. Previously unknown putative viral protein ligands for the PDZ domains of Scribble and Erbin were also identified. Thus, we demonstrate that our ProP-PD libraries are useful tools for probing PDZ domain interactions. The method can be extended to interrogate all potential eukaryotic, bacterial, and viral SLiMs and we suggest it will be a highly valuable approach for studying cellular and pathogen-host protein-protein interactions.

Berberine-induced Inactivation of Signal Transducer and Activator of Transcription 5 Signaling Promotes Male-specific Expression of a Bile Acid Uptake Transporter.

PubMed

Bu, Pengli; Le, Yuan; Zhang, Yue; Zhang, Youcai; Cheng, Xingguo

2017-03-17

Sodium-taurocholate co-transporting polypeptide (Ntcp/NTCP) is the major uptake transporter of bile salts in mouse and human livers. In certain diseases, including endotoxemia, cholestasis, diabetes, and hepatocarcinoma, Ntcp/NTCP expression is markedly reduced, which interferes with enterohepatic circulation of bile salts, impairing the absorption of lipophilic compounds. Therefore, normal Ntcp/NTCP expression in the liver is physiologically important. Berberine is an herbal medicine used historically to improve liver function and has recently been shown to repress STAT signaling. However, berberine effects on Ntcp/NTCP expression are unknown, prompting use to investigate this possible connection. Our results showed that berberine dose-dependently increased Ntcp expression in male mouse liver and decreased taurocholic acid levels in serum but increased them in the liver. In mouse and human hepatoma cells, berberine induced Ntcp/NTCP mRNA and protein expression and increased cellular uptake of [3H] taurocholate. Mechanistically, berberine decreased nuclear protein levels of phospho-JAK2 and phospho-STAT5, thus disrupting the JAK2-STAT5 signaling. Moreover, berberine stimulated luciferase reporter expression from the mouse Ntcp promoter when one putative STAT5 response element (RE) (-1137 bp) was deleted and from the human NTCP promoter when three putative STAT5REs (-2898, -2164, and -691 bp) were deleted. Chromatin immunoprecipitation demonstrated that berberine decreased binding of phospho-STAT5 protein to the-2164 and -691 bp STAT5REs in the human NTCP promoter. In summary, berberine-disrupted STAT5 signaling promoted mouse and human Ntcp/NTCP expression, resulting in enhanced bile acid uptake. Therefore, berberine may be a therapeutic candidate compound for maintaining bile acid homeostasis. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Tiered High-Throughput Screening Approach to Identify Thyroperoxidase Inhibitors Within the ToxCast Phase I and II Chemical Libraries

PubMed Central

Watt, Eric D.; Hornung, Michael W.; Hedge, Joan M.; Judson, Richard S.; Crofton, Kevin M.; Houck, Keith A.; Simmons, Steven O.

2016-01-01

High-throughput screening for potential thyroid-disrupting chemicals requires a system of assays to capture multiple molecular-initiating events (MIEs) that converge on perturbed thyroid hormone (TH) homeostasis. Screening for MIEs specific to TH-disrupting pathways is limited in the U.S. Environmental Protection Agency ToxCast screening assay portfolio. To fill 1 critical screening gap, the Amplex UltraRed-thyroperoxidase (AUR-TPO) assay was developed to identify chemicals that inhibit TPO, as decreased TPO activity reduces TH synthesis. The ToxCast phase I and II chemical libraries, comprised of 1074 unique chemicals, were initially screened using a single, high concentration to identify potential TPO inhibitors. Chemicals positive in the single-concentration screen were retested in concentration-response. Due to high false-positive rates typically observed with loss-of-signal assays such as AUR-TPO, we also employed 2 additional assays in parallel to identify possible sources of nonspecific assay signal loss, enabling stratification of roughly 300 putative TPO inhibitors based upon selective AUR-TPO activity. A cell-free luciferase inhibition assay was used to identify nonspecific enzyme inhibition among the putative TPO inhibitors, and a cytotoxicity assay using a human cell line was used to estimate the cellular tolerance limit. Additionally, the TPO inhibition activities of 150 chemicals were compared between the AUR-TPO and an orthogonal peroxidase oxidation assay using guaiacol as a substrate to confirm the activity profiles of putative TPO inhibitors. This effort represents the most extensive TPO inhibition screening campaign to date and illustrates a tiered screening approach that focuses resources, maximizes assay throughput, and reduces animal use. PMID:26884060

Multi-Targeted Molecular Effects of Hibiscus sabdariffa Polyphenols: An Opportunity for a Global Approach to Obesity

PubMed Central

Herranz-López, María; Olivares-Vicente, Mariló; Barrajón-Catalán, Enrique; Segura-Carretero, Antonio; Joven, Jorge; Micol, Vicente

2017-01-01

Improper diet can alter gene expression by breaking the energy balance equation and changing metabolic and oxidative stress biomarkers, which can result in the development of obesity-related metabolic disorders. The pleiotropic effects of dietary plant polyphenols are capable of counteracting by modulating different key molecular targets at the cell, as well as through epigenetic modifications. Hibiscus sabdariffa (HS)-derived polyphenols are known to ameliorate various obesity-related conditions. Recent evidence leads to propose the complex nature of the underlying mechanism of action. This multi-targeted mechanism includes the regulation of energy metabolism, oxidative stress and inflammatory pathways, transcription factors, hormones and peptides, digestive enzymes, as well as epigenetic modifications. This article reviews the accumulated evidence on the multiple anti-obesity effects of HS polyphenols in cell and animal models, as well as in humans, and its putative molecular targets. In silico studies reveal the capacity of several HS polyphenols to act as putative ligands for different digestive and metabolic enzymes, which may also deserve further attention. Therefore, a global approach including integrated and networked omics techniques, virtual screening and epigenetic analysis is necessary to fully understand the molecular mechanisms of HS polyphenols and metabolites involved, as well as their possible implications in the design of safe and effective polyphenolic formulations for obesity. PMID:28825642

Tiered High-Throughput Screening Approach to Identify ...

EPA Pesticide Factsheets

High-throughput screening (HTS) for potential thyroid–disrupting chemicals requires a system of assays to capture multiple molecular-initiating events (MIEs) that converge on perturbed thyroid hormone (TH) homeostasis. Screening for MIEs specific to TH-disrupting pathways is limited in the US EPA ToxCast screening assay portfolio. To fill one critical screening gap, the Amplex UltraRed-thyroperoxidase (AUR-TPO) assay was developed to identify chemicals that inhibit TPO, as decreased TPO activity reduces TH synthesis. The ToxCast Phase I and II chemical libraries, comprised of 1,074 unique chemicals, were initially screened using a single, high concentration to identify potential TPO inhibitors. Chemicals positive in the single concentration screen were retested in concentration-response. Due to high false positive rates typically observed with loss-of-signal assays such as AUR-TPO, we also employed two additional assays in parallel to identify possible sources of nonspecific assay signal loss, enabling stratification of roughly 300 putative TPO inhibitors based upon selective AUR-TPO activity. A cell-free luciferase inhibition assay was used to identify nonspecific enzyme inhibition among the putative TPO inhibitors, and a cytotoxicity assay using a human cell line was used to estimate the cellular tolerance limit. Additionally, the TPO inhibition activities of 150 chemicals were compared between the AUR-TPO and an orthogonal peroxidase oxidation assay using

Multi-Targeted Molecular Effects of Hibiscus sabdariffa Polyphenols: An Opportunity for a Global Approach to Obesity.

PubMed

Herranz-López, María; Olivares-Vicente, Mariló; Encinar, José Antonio; Barrajón-Catalán, Enrique; Segura-Carretero, Antonio; Joven, Jorge; Micol, Vicente

2017-08-20

Improper diet can alter gene expression by breaking the energy balance equation and changing metabolic and oxidative stress biomarkers, which can result in the development of obesity-related metabolic disorders. The pleiotropic effects of dietary plant polyphenols are capable of counteracting by modulating different key molecular targets at the cell, as well as through epigenetic modifications. Hibiscus sabdariffa (HS)-derived polyphenols are known to ameliorate various obesity-related conditions. Recent evidence leads to propose the complex nature of the underlying mechanism of action. This multi-targeted mechanism includes the regulation of energy metabolism, oxidative stress and inflammatory pathways, transcription factors, hormones and peptides, digestive enzymes, as well as epigenetic modifications. This article reviews the accumulated evidence on the multiple anti-obesity effects of HS polyphenols in cell and animal models, as well as in humans, and its putative molecular targets. In silico studies reveal the capacity of several HS polyphenols to act as putative ligands for different digestive and metabolic enzymes, which may also deserve further attention. Therefore, a global approach including integrated and networked omics techniques, virtual screening and epigenetic analysis is necessary to fully understand the molecular mechanisms of HS polyphenols and metabolites involved, as well as their possible implications in the design of safe and effective polyphenolic formulations for obesity.

Safety of targeting ROR1 in primates with chimeric antigen receptor-modified T cells

PubMed Central

Berger, Carolina; Sommermeyer, Daniel; Hudecek, Michael; Berger, Michael; Balakrishnan, Ashwini; Paszkiewicz, Paulina J.; Kosasih, Paula L.; Rader, Christoph; Riddell, Stanley R.

2014-01-01

Genetic engineering of T cells for adoptive transfer by introducing a tumor-targeting chimeric antigen receptor (CAR) is a new approach to cancer immunotherapy. A challenge for the field is to define cell surface molecules that are both preferentially expressed on tumor cells and can be safely targeted with T cells. The orphan tyrosine kinase receptor ROR1 is a candidate target for T-cell therapy with CAR-modified T cells (CAR-T cells) since it is expressed on the surface of many lymphatic and epithelial malignancies and has a putative role in tumor cell survival. The cell surface isoform of ROR1 is expressed in embryogenesis but absent in adult tissues except for B-cell precursors, and low levels of transcripts in adipocytes, pancreas, and lung. ROR1 is highly conserved between humans and macaques and has a similar pattern of tissue expression. To determine if low-level ROR1-expression on normal cells would result in toxicity or adversely affect CAR-T cell survival and/or function, we adoptively transferred autologous ROR1 CAR-T cells into nonhuman primates. ROR1 CAR-T cells did not cause overt toxicity to normal organs and accumulated in bone marrow and lymph node sites where ROR1-positive B cells were present. The findings support the clinical evaluation of ROR1 CAR-T cells for ROR1+ malignancies and demonstrate the utility of nonhuman primates for evaluating the safety of immunotherapy with engineered T cells specific for tumor-associated molecules that are homologous between humans and nonhuman primates. PMID:25355068

Adaptive reconfiguration of the human NK-cell compartment in response to cytomegalovirus: a different perspective of the host-pathogen interaction.

PubMed

Muntasell, Aura; Vilches, Carlos; Angulo, Ana; López-Botet, Miguel

2013-05-01

As discussed in this review, human cytomegalovirus (HCMV) infection in healthy individuals is associated with a variable and persistent increase of NK cells expressing the CD94/NKG2C activating receptor. The expansion of NKG2C(+) NK cells reported in other infectious diseases is systematically associated with HCMV co-infection. The functionally mature NKG2C(bright) NK-cell subset expanding in HCMV(+) individuals displays inhibitory Ig-like receptors (KIR and LILRB1) specific for self HLA class I, and low levels of NKp46 and NKp30 activating receptors. Such reconfiguration of the NK-cell compartment appears particularly marked in immunocompromised patients and in children with symptomatic congenital infection, thus suggesting that its magnitude may be inversely related with the efficiency of the T-cell-mediated response. This effect of HCMV infection is reminiscent of the pattern of response of murine Ly49H(+) NK cells against murine CMV (MCMV), and it has been hypothesized that a cognate interaction of the CD94/NKG2C receptor with HCMV-infected cells may drive the expansion of the corresponding NK-cell subset. Yet, the precise role of NKG2C(+) cells in the control of HCMV infection, the molecular mechanisms underlying the NK-cell compartment redistribution, as well as its putative influence in the response to other pathogens and tumors remain open issues. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Isolation, immortalization, and characterization of a human breast epithelial cell line with stem cell properties

PubMed Central

Gudjonsson, Thorarinn; Villadsen, René; Nielsen, Helga Lind; Rønnov-Jessen, Lone; Bissell, Mina J.; Petersen, Ole William

2002-01-01

The epithelial compartment of the human breast comprises two distinct lineages: the luminal epithelial and the myoepithelial lineage. We have shown previously that a subset of the luminal epithelial cells could convert to myoepithelial cells in culture signifying the possible existence of a progenitor cell. We therefore set out to identify and isolate the putative precursor in the luminal epithelial compartment. Using cell surface markers and immunomagnetic sorting, we isolated two luminal epithelial cell populations from primary cultures of reduction mammoplasties. The major population coexpresses sialomucin (MUC+) and epithelial-specific antigen (ESA+) whereas the minor population has a suprabasal position and expresses epithelial specific antigen but no sialomucin (MUC−/ESA+). Two cell lines were further established by transduction of the E6/E7 genes from human papilloma virus type 16. Both cell lines maintained a luminal epithelial phenotype as evidenced by expression of the tight junction proteins, claudin-1 and occludin, and by generation of a high transepithelial electrical resistance on semipermeable filters. Whereas in clonal cultures, the MUC+/ESA+ epithelial cell line was luminal epithelial restricted in its differentiation repertoire, the suprabasal-derived MUC−/ESA+ epithelial cell line was able to generate itself as well as MUC+/ESA+ epithelial cells and Thy-1+/α-smooth muscle actin+ (ASMA+) myoepithelial cells. The MUC−/ESA+ epithelial cell line further differed from the MUC+/ESA+ epithelial cell line by the expression of keratin K19, a feature of a subpopulation of epithelial cells in terminal duct lobular units in vivo. Within a reconstituted basement membrane, the MUC+/ESA+ epithelial cell line formed acinus-like spheres. In contrast, the MUC−/ESA+ epithelial cell line formed elaborate branching structures resembling uncultured terminal duct lobular units both by morphology and marker expression. Similar structures were obtained by inoculating the extracellular matrix-embedded cells subcutaneously in nude mice. Thus, MUC−/ESA+ epithelial cells within the luminal epithelial lineage may function as precursor cells of terminal duct lobular units in the human breast. PMID:11914275

Comparative analysis of programmed cell death pathways in filamentous fungi.

PubMed

Fedorova, Natalie D; Badger, Jonathan H; Robson, Geoff D; Wortman, Jennifer R; Nierman, William C

2005-12-08

Fungi can undergo autophagic- or apoptotic-type programmed cell death (PCD) on exposure to antifungal agents, developmental signals, and stress factors. Filamentous fungi can also exhibit a form of cell death called heterokaryon incompatibility (HI) triggered by fusion between two genetically incompatible individuals. With the availability of recently sequenced genomes of Aspergillus fumigatus and several related species, we were able to define putative components of fungi-specific death pathways and the ancestral core apoptotic machinery shared by all fungi and metazoa. Phylogenetic profiling of HI-associated proteins from four Aspergilli and seven other fungal species revealed lineage-specific protein families, orphan genes, and core genes conserved across all fungi and metazoa. The Aspergilli-specific domain architectures include NACHT family NTPases, which may function as key integrators of stress and nutrient availability signals. They are often found fused to putative effector domains such as Pfs, SesB/LipA, and a newly identified domain, HET-s/LopB. Many putative HI inducers and mediators are specific to filamentous fungi and not found in unicellular yeasts. In addition to their role in HI, several of them appear to be involved in regulation of cell cycle, development and sexual differentiation. Finally, the Aspergilli possess many putative downstream components of the mammalian apoptotic machinery including several proteins not found in the model yeast, Saccharomyces cerevisiae. Our analysis identified more than 100 putative PCD associated genes in the Aspergilli, which may help expand the range of currently available treatments for aspergillosis and other invasive fungal diseases. The list includes species-specific protein families as well as conserved core components of the ancestral PCD machinery shared by fungi and metazoa.

Substances released from probiotic Lactobacillus rhamnosus GR-1 potentiate NF-κB activity in Escherichia coli-stimulated urinary bladder cells.

PubMed

Karlsson, Mattias; Scherbak, Nikolai; Khalaf, Hazem; Olsson, Per-Erik; Jass, Jana

2012-11-01

Lactobacillus rhamnosus GR-1 is a probiotic bacterium used to maintain urogenital health. The putative mechanism for its probiotic effect is by modulating the host immunity. Urinary tract infections (UTI) are often caused by uropathogenic Escherichia coli that frequently evade or suppress immune responses in the bladder and can target pathways, including nuclear factor-kappaB (NF-κB). We evaluated the role of L. rhamnosus GR-1 on NF-κB activation in E. coli-stimulated bladder cells. Viable L. rhamnosus GR-1 was found to potentiate NF-κB activity in E. coli-stimulated T24 bladder cells, whereas heat-killed lactobacilli demonstrated a marginal increase in NF-κB activity. Surface components released by trypsin- or LiCl treatment, or the resultant heat-killed shaved lactobacilli, had no effect on NF-κB activity. Isolation of released products from L. rhamnosus GR-1 demonstrated that the induction of NF-κB activity was owing to released product(s) with a relatively large native size. Several putative immunomodulatory proteins were identified, namely GroEL, elongation factor Tu and NLP/P60. GroEL and elongation factor Tu have previously been shown to elicit immune responses from human cells. Isolating and using immune-augmenting substances produced by lactobacilli is a novel strategy for the prevention or treatment of UTI caused by immune-evading E. coli. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Murine tissue-engineered stomach demonstrates epithelial differentiation.

PubMed

Speer, Allison L; Sala, Frederic G; Matthews, Jamil A; Grikscheit, Tracy C

2011-11-01

Gastric cancer remains the second largest cause of cancer-related mortality worldwide. Postgastrectomy morbidity is considerable and quality of life is poor. Tissue-engineered stomach is a potential replacement solution to restore adequate food reservoir and gastric physiology. In this study, we performed a detailed investigation of the development of tissue-engineered stomach in a mouse model, specifically evaluating epithelial differentiation, proliferation, and the presence of putative stem cell markers. Organoid units were isolated from <3 wk-old mouse glandular stomach and seeded onto biodegradable scaffolds. The constructs were implanted into the omentum of adult mice. Implants were harvested at designated time points and analyzed with histology and immunohistochemistry. Tissue-engineered stomach grows as an expanding sphere with a simple columnar epithelium organized into gastric glands and an adjacent muscularis. The regenerated gastric epithelium demonstrates differentiation of all four cell types: mucous, enteroendocrine, chief, and parietal cells. Tissue-engineered stomach epithelium proliferates at a rate comparable to native glandular stomach and expresses two putative stem cell markers: DCAMKL-1 and Lgr5. This study demonstrates the successful generation of tissue-engineered stomach in a mouse model for the first time. Regenerated gastric epithelium is able to appropriately proliferate and differentiate. The generation of murine tissue-engineered stomach is a necessary advance as it provides the transgenic tools required to investigate the molecular and cellular mechanisms of this regenerative process. Delineating the mechanism of how tissue-engineered stomach develops in vivo is an important precursor to its use as a human stomach replacement therapy. Copyright © 2011 Elsevier Inc. All rights reserved.

The role of BST2/tetherin in infection with the feline retroviruses

PubMed Central

Dietrich, Isabelle; Hosie, Margaret J.; Willett, Brian J.

2014-01-01

The recently identified host restriction factor tetherin (BST-2, CD317) potently inhibits the release of nascent retrovirus particles from infected cells. Recently, we reported the identification and characterization of tetherin as a novel feline retroviral restriction factor. Based on homology to human tetherin we identified a putative tetherin gene in the genome of the domestic cat (Felis catus) which was found to be expressed in different feline cell lines both prior to and post treatment with either type I or type II interferon (IFN). The predicted structure of feline tetherin (feTHN) was that of a type II single-pass transmembrane protein encoding an N-terminal transmembrane anchor, central predicted coiled-coil bearing extracellular domain to promote dimerization, and a C-terminal GPI-anchor, consistent with conservation of structure between human and feline tetherin. FeTHN displayed potent inhibition of feline immunodeficiency virus (FIV) and human immunodeficiency virus type 1 (HIV-1) particle release in single-cycle replication assays. Notably, feTHN activity was resistant to antagonism by HIV-1 Vpu. However, stable ectopic expression of feTHN mRNA in different feline cell lines had no inhibitory effect on the growth of diverse primary or cell culture-adapted strains of FIV. Hence, whereas feline tetherin efficiently blocks viral particle release in single-cycle replication assays, it might not prevent dissemination of feline retroviruses in vivo. PMID:21715020

The putative G-protein coupled estrogen receptor agonist G-1 suppresses proliferation of ovarian and breast cancer cells in a GPER-independent manner

PubMed Central

Wang, Cheng; Lv, Xiangmin; Jiang, Chao; Davis, John S

2012-01-01

G-protein coupled estrogen receptor 1 (GPER) plays an important role in mediating estrogen action in many different tissues under both physiological and pathological conditions. G-1 (1-[4-(6-bromobenzo[1,3]dioxol-5yl)-3a,4,5,9b-tetrahydro-3H-cyclopenta [c]quinolin-8-yl]-ethanone) has been developed as a selective GPER agonist to distinguish estrogen actions mediated by GPER from those mediated by classic estrogen receptors. In the present study, we surprisingly found that G-1 suppressed proliferation and induced apoptosis of KGN cells (a human ovarian granulosa cell tumor cell line), actions that were not blocked by a selective GPER antagonist G15 or siRNA knockdown of GPER. G-1 also suppressed proliferation and induced cell apoptosis in GPER-negative HEK-293 cells and MDA-MB 231 breast cancer cells. Our results demonstrate that G-1 suppresses proliferation of ovarian and breast cancer cells in a GPER-independent manner. G-1 may be a candidate for the development of drugs against ovarian and breast cancer. PMID:23145207

Extremotolerant tardigrade genome and improved radiotolerance of human cultured cells by tardigrade-unique protein

PubMed Central

Hashimoto, Takuma; Horikawa, Daiki D.; Saito, Yuki; Kuwahara, Hirokazu; Kozuka-Hata, Hiroko; Shin-I, Tadasu; Minakuchi, Yohei; Ohishi, Kazuko; Motoyama, Ayuko; Aizu, Tomoyuki; Enomoto, Atsushi; Kondo, Koyuki; Tanaka, Sae; Hara, Yuichiro; Koshikawa, Shigeyuki; Sagara, Hiroshi; Miura, Toru; Yokobori, Shin-ichi; Miyagawa, Kiyoshi; Suzuki, Yutaka; Kubo, Takeo; Oyama, Masaaki; Kohara, Yuji; Fujiyama, Asao; Arakawa, Kazuharu; Katayama, Toshiaki; Toyoda, Atsushi; Kunieda, Takekazu

2016-01-01

Tardigrades, also known as water bears, are small aquatic animals. Some tardigrade species tolerate almost complete dehydration and exhibit extraordinary tolerance to various physical extremes in the dehydrated state. Here we determine a high-quality genome sequence of Ramazzottius varieornatus, one of the most stress-tolerant tardigrade species. Precise gene repertoire analyses reveal the presence of a small proportion (1.2% or less) of putative foreign genes, loss of gene pathways that promote stress damage, expansion of gene families related to ameliorating damage, and evolution and high expression of novel tardigrade-unique proteins. Minor changes in the gene expression profiles during dehydration and rehydration suggest constitutive expression of tolerance-related genes. Using human cultured cells, we demonstrate that a tardigrade-unique DNA-associating protein suppresses X-ray-induced DNA damage by ∼40% and improves radiotolerance. These findings indicate the relevance of tardigrade-unique proteins to tolerability and tardigrades could be a bountiful source of new protection genes and mechanisms. PMID:27649274

Extremotolerant tardigrade genome and improved radiotolerance of human cultured cells by tardigrade-unique protein.

PubMed

Hashimoto, Takuma; Horikawa, Daiki D; Saito, Yuki; Kuwahara, Hirokazu; Kozuka-Hata, Hiroko; Shin-I, Tadasu; Minakuchi, Yohei; Ohishi, Kazuko; Motoyama, Ayuko; Aizu, Tomoyuki; Enomoto, Atsushi; Kondo, Koyuki; Tanaka, Sae; Hara, Yuichiro; Koshikawa, Shigeyuki; Sagara, Hiroshi; Miura, Toru; Yokobori, Shin-Ichi; Miyagawa, Kiyoshi; Suzuki, Yutaka; Kubo, Takeo; Oyama, Masaaki; Kohara, Yuji; Fujiyama, Asao; Arakawa, Kazuharu; Katayama, Toshiaki; Toyoda, Atsushi; Kunieda, Takekazu

2016-09-20

Tardigrades, also known as water bears, are small aquatic animals. Some tardigrade species tolerate almost complete dehydration and exhibit extraordinary tolerance to various physical extremes in the dehydrated state. Here we determine a high-quality genome sequence of Ramazzottius varieornatus, one of the most stress-tolerant tardigrade species. Precise gene repertoire analyses reveal the presence of a small proportion (1.2% or less) of putative foreign genes, loss of gene pathways that promote stress damage, expansion of gene families related to ameliorating damage, and evolution and high expression of novel tardigrade-unique proteins. Minor changes in the gene expression profiles during dehydration and rehydration suggest constitutive expression of tolerance-related genes. Using human cultured cells, we demonstrate that a tardigrade-unique DNA-associating protein suppresses X-ray-induced DNA damage by ∼40% and improves radiotolerance. These findings indicate the relevance of tardigrade-unique proteins to tolerability and tardigrades could be a bountiful source of new protection genes and mechanisms.

Endoplasmic reticulum localized PerA is required for cell wall integrity, azole drug resistance, and virulence in Aspergillus fumigatus

PubMed Central

Chung, Dawoon; Thammahong, Arsa; Shepardson, Kelly M.; Blosser, Sara J.; Cramer, Robert A.

2014-01-01

Summary GPI-anchoring is a universal and critical post-translational protein modification in eukaryotes. In fungi, many cell wall proteins are GPI-anchored, and disruption of GPI-anchored proteins impairs cell wall integrity. After being synthesized and attached to target proteins, GPI anchors undergo modification on lipid moieties. In spite of its importance for GPI-anchored protein functions, our current knowledge of GPI lipid remodeling in pathogenic fungi is limited. In this study, we characterized the role of a putative GPI lipid remodeling protein, designated PerA, in the human pathogenic fungus Aspergillus fumigatus. PerA localizes to the endoplasmic reticulum and loss of PerA leads to striking defects in cell wall integrity. A perA null mutant has decreased conidia production, increased susceptibility to triazole antifungal drugs, and is avirulent in a murine model of invasive pulmonary aspergillosis. Interestingly, loss of PerA increases exposure of β-glucan and chitin content on the hyphal cell surface, but diminished TNF production by bone marrow derived macrophages relative to wild type. Given the structural specificity of fungal GPI-anchors, which is different from humans, understanding GPI lipid remodeling and PerA function in A. fumigatus is a promising research direction to uncover a new fungal specific antifungal drug target. PMID:24779420

Comparative Analysis of AhR-Mediated TCDD-Elicited Gene Expression in Human Liver Adult Stem Cells

PubMed Central

Kim, Suntae; Dere, Edward; Burgoon, Lyle D.; Chang, Chia-Cheng; Zacharewski, Timothy R.

2009-01-01

Time course and dose-response studies were conducted in HL1-1 cells, a human liver cell line with stem cell–like characteristics, to assess the differential gene expression elicited by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) compared with other established models. Cells were treated with 0.001, 0.01, 0.1, 1, 10, or 100nM TCDD or dimethyl sulfoxide vehicle control for 12 h for the dose-response study, or with 10nM TCDD or vehicle for 1, 2, 4, 8, 12, 24, or 48 h for the time course study. Elicited changes were monitored using a human cDNA microarray with 6995 represented genes. Empirical Bayes analysis identified 144 genes differentially expressed at one or more time points following treatment. Most genes exhibited dose-dependent responses including CYP1A1, CYP1B1, ALDH1A3, and SLC7A5 genes. Comparative analysis of HL1-1 differential gene expression to human HepG2 data identified 74 genes with comparable temporal expression profiles including 12 putative primary responses. HL1-1–specific changes were related to lipid metabolism and immune responses, consistent with effects elicited in vivo. Furthermore, comparative analysis of HL1-1 cells with mouse Hepa1c1c7 hepatoma cell lines and C57BL/6 hepatic tissue identified 18 and 32 commonly regulated orthologous genes, respectively, with functions associated with signal transduction, transcriptional regulation, metabolism and transport. Although some common pathways are affected, the results suggest that TCDD elicits species- and model-specific gene expression profiles. PMID:19684285

Cytotoxicity and gene expression profiling of polyhexamethylene guanidine hydrochloride in human alveolar A549 cells.

PubMed

Jung, Ha-Na; Zerin, Tamanna; Podder, Biswajit; Song, Ho-Yeon; Kim, Yong-Sik

2014-06-01

In Korea, lung disease of children and pregnant women associated with humidifier disinfectant use has become a major concern. A common sterilizer is polyhexamethylene guanidine (PHMG), a member of the guanidine family of antiseptics. This study was done to elucidate the putative cytotoxic effect of PHMG and the PHMG-mediated altered gene expression in human alveolar epithelial A549 cells in vitro. Cell viability analyses revealed the potent cytotoxicity of PHMG, with cell death evident at as low as 5 μg/mL. Death was dose- and time-dependent, and was associated with formation of intracellular reactive oxygen species, and apoptosis significantly, at even 2 μg/mL concentration. The gene expression profile in A549 cells following 24 h exposure to 5 μg/mL of PHMG was investigated using DNA microarray analysis. Changes in gene expression relevant to the progression of cell death included induction of genes related to apoptosis, autophagy, fibrosis, and cell cycle. However, the expressions of genes encoding antioxidant and detoxifying enzymes were down-regulated or not affected. The altered expression of selected genes was confirmed by quantitative reverse transcription-polymerase chain reaction and Western blot analyses. The collective data suggest that PHMG confers cellular toxicity through the generation of intracellular reactive oxygen species and alteration of gene expression. Copyright © 2014 Elsevier Ltd. All rights reserved.

SOX2 regulates self-renewal and tumorigenicity of human melanoma-initiating cells.

PubMed

Santini, R; Pietrobono, S; Pandolfi, S; Montagnani, V; D'Amico, M; Penachioni, J Y; Vinci, M C; Borgognoni, L; Stecca, B

2014-09-18

Melanoma is one of the most aggressive types of human cancer, characterized by enhanced heterogeneity and resistance to conventional therapy at advanced stages. We and others have previously shown that HEDGEHOG-GLI (HH-GLI) signaling is required for melanoma growth and for survival and expansion of melanoma-initiating cells (MICs). Recent reports indicate that HH-GLI signaling regulates a set of genes typically expressed in embryonic stem cells, including SOX2 (sex-determining region Y (SRY)-Box2). Here we address the function of SOX2 in human melanomas and MICs and its interaction with HH-GLI signaling. We find that SOX2 is highly expressed in melanoma stem cells. Knockdown of SOX2 sharply decreases self-renewal in melanoma spheres and in putative melanoma stem cells with high aldehyde dehydrogenase activity (ALDH(high)). Conversely, ectopic expression of SOX2 in melanoma cells enhances their self-renewal in vitro. SOX2 silencing also inhibits cell growth and induces apoptosis in melanoma cells. In addition, depletion of SOX2 progressively abrogates tumor growth and leads to a significant decrease in tumor-initiating capability of ALDH(high) MICs upon xenotransplantation, suggesting that SOX2 is required for tumor initiation and for continuous tumor growth. We show that SOX2 is regulated by HH signaling and that the transcription factors GLI1 and GLI2, the downstream effectors of HH-GLI signaling, bind to the proximal promoter region of SOX2 in primary melanoma cells. In functional studies, we find that SOX2 function is required for HH-induced melanoma cell growth and MIC self-renewal in vitro. Thus SOX2 is a critical factor for self-renewal and tumorigenicity of MICs and an important mediator of HH-GLI signaling in melanoma. These findings could provide the basis for novel therapeutic strategies based on the inhibition of SOX2 for the treatment of a subset of human melanomas.

Regulation of human heme oxygenase-1 gene expression under thermal stress.

PubMed

Okinaga, S; Takahashi, K; Takeda, K; Yoshizawa, M; Fujita, H; Sasaki, H; Shibahara, S

1996-06-15

Heme oxygenase-1 is an essential enzyme in heme catabolism, and its human gene promoter contains a putative heat shock element (HHO-HSE). This study was designed to analyze the regulation of human heme oxygenase-1 gene expression under thermal stress. The amounts of heme oxygenase-1 protein were not increased by heat shock (incubation at 42 degrees C) in human alveolar macrophages and in a human erythroblastic cell line, YN-1-0-A, whereas heat shock protein 70 (HSP70) was noticeably induced. However, heat shock factor does bind in vitro to HHO-HSE and the synthetic HHO-HSE by itself is sufficient to confer the increase in the transient expression of a reporter gene upon heat shock. The deletion of the sequence, located downstream from HHO-HSE, resulted in the activation of a reporter gene by heat shock. These results suggest that HHO-HSE is potentially functional but is repressed in vivo. Interestingly, heat shock abolished the remarkable increase in the levels of heme oxygenase-1 mRNA in YN-1-0-A cells treated with hemin or cadmium, in which HSP70 mRNA was noticeably induced. Furthermore, transient expression assays showed that heat shock inhibits the cadmium-mediated activation of the heme oxygenase-1 promoter, whereas the HSP70 gene promoter was activated upon heat shock. Such regulation of heme oxygenase-1 under thermal stress may be of physiologic significance in erythroid cells.

Establishment and characterization of novel epithelial-like cell lines derived from human periodontal ligament tissue in vitro.

PubMed

Tansriratanawong, Kallapat; Ishikawa, Hiroshi; Toyomura, Junko; Sato, Soh

2017-10-01

In this study, novel human-derived epithelial-like cells (hEPLCs) lines were established from periodontal ligament (PDL) tissues, which were composed of a variety of cell types and exhibited complex cellular activities. To elucidate the putative features distinguishing these from epithelial rest of Malassez (ERM), we characterized hEPLCs based on cell lineage markers and tight junction protein expression. The aim of this study was, therefore, to establish and characterize hEPLCs lines from PDL tissues. The hEPLCs were isolated from PDL of third molar teeth. Cellular morphology and cell organelles were observed thoroughly. The characteristics of epithelial-endothelial-mesenchymal-like cells were compared in several markers by gene expression and immunofluorescence, to ERM and human umbilical-vein endothelial cells (HUVECs). The resistance between cellular junctions was assessed by transepithelial electron resistance, and inflammatory cytokines were detected by ELISA after infecting hEPLCs with periodontopathic bacteria. The hEPLCs developed into small epithelial-like cells in pavement appearance similar to ERM. However, gene expression patterns and immunofluorescence results were different from ERM and HUVECs, especially in tight junction markers (Claudin, ZO-1, and Occludins), and endothelial markers (vWF, CD34). The transepithelial electron resistance indicated higher resistance in hEPLCs, as compared to ERM. Periodontopathic bacteria were phagocytosed with upregulation of inflammatory cytokine secretion within 24 h. In conclusion, hEPLCs that were derived using the single cell isolation method formed tight multilayers colonies, as well as strongly expressed tight junction markers in gene expression and immunofluorescence. Novel hEPLCs lines exhibited differently from ERM, which might provide some specific functions such as metabolic exchange and defense mechanism against bacterial invasion in periodontal tissue.

One pyrimidine dimer inactivates expression of a transfected gene in xeroderma pigmentosum cells

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

Protic-Sabljic, M.; Kraemer, K.H.

1985-10-01

The authors have developed a host cell reactivation assay of DNA repair utilizing UV-treated plasmid vectors. The assay primarily reflects cellular repair of transcriptional activity of damaged DNA measured indirectly as enzyme activity of the transfected genes. They studied three plasmids (pSV2cat, 5020 base pairs; pSV2catSVgpt, 7268 base pairs; and pRSVcat, 5027 base pairs) with different sizes and promoters carrying the bacterial cat gene (CAT, chloramphenicol acetyltransferase) in a construction that permits cat expression in human cells. All human simian virus 40-transformed cells studied expressed high levels of the transfected cat gene. UV treatment of the plasmids prior to transfectionmore » resulted in differential decrease in CAT activity in different cell lines. With pSV2catSVgpt, UV inactivation of CAT expression was greater in the xeroderma pigmentosum group A and D lines than in the other human cell lines tested. The D0 of the CAT inactivation curve was 50 J X m-2 for pSV2cat and for pRSVcat in the xeroderma pigmentosum group A cells. The similarity of the D0 data in the xeroderma pigmentosum group A cells for three plasmids of different size and promoters implies they all have similar UV-inactivation target size. UV-induced pyrimidine dimer formation in the plasmids was quantified by assay of the number of UV-induced T4 endonuclease V-sensitive sites. In the most sensitive xeroderma pigmentosum cells, with all three plasmids, one UV-induced pyrimidine dimer inactivates a target of about 2 kilobases, close to the size of the putative CAT mRNA.« less

In vitro modeling of human pancreatic duct epithelial cell transformation defines gene expression changes induced by K-ras oncogenic activation in pancreatic carcinogenesis.

PubMed

Qian, Jiaying; Niu, Jiangong; Li, Ming; Chiao, Paul J; Tsao, Ming-Sound

2005-06-15

Genetic analysis of pancreatic ductal adenocarcinomas and their putative precursor lesions, pancreatic intraepithelial neoplasias (PanIN), has shown a multistep molecular paradigm for duct cell carcinogenesis. Mutational activation or inactivation of the K-ras, p16(INK4A), Smad4, and p53 genes occur at progressive and high frequencies in these lesions. Oncogenic activation of the K-ras gene occurs in >90% of pancreatic ductal carcinoma and is found early in the PanIN-carcinoma sequence, but its functional roles remain poorly understood. We show here that the expression of K-ras(G12V) oncogene in a near diploid HPV16-E6E7 gene immortalized human pancreatic duct epithelial cell line originally derived from normal pancreas induced the formation of carcinoma in 50% of severe combined immunodeficient mice implanted with these cells. A tumor cell line established from one of these tumors formed ductal cancer when implanted orthotopically. These cells also showed increased activation of the mitogen-activated protein kinase, AKT, and nuclear factor-kappaB pathways. Microarray expression profiling studies identified 584 genes whose expression seemed specifically up-regulated by the K-ras oncogene expression. Forty-two of these genes have been reported previously as differentially overexpressed in pancreatic cancer cell lines or primary tumors. Real-time PCR confirmed the overexpression of a large number of these genes. Immunohistochemistry done on tissue microarrays constructed from PanIN and pancreatic cancer samples showed laminin beta3 overexpression starting in high-grade PanINs and occurring in >90% of pancreatic ductal carcinoma. The in vitro modeling of human pancreatic duct epithelial cell transformation may provide mechanistic insights on gene expression changes that occur during multistage pancreatic duct cell carcinogenesis.

Host cell recruitment patterns by bone morphogenetic protein-2 releasing hyaluronic acid hydrogels in a mouse subcutaneous environment.

PubMed

Todeschi, Maria R; El Backly, Rania M; Varghese, Oommen P; Hilborn, Jöns; Cancedda, Ranieri; Mastrogiacomo, Maddalena

2017-07-01

This study aimed to identify host cell recruitment patterns in a mouse model in response to rhBMP-2 releasing hyaluronic acid hydrogels and influence of added nano-hydroxyapatite particles on rhBMP-2 release and pattern of bone formation. Implanted gels were retrieved after implantation and cells were enzymatically dissociated for flow cytometric analysis. Percentages of macrophages, progenitor endothelial cells and putative mesenchymal stem cells were measured. Implants were evaluated for BMP-2 release by ELISA and by histology to monitor tissue formation. Hyaluronic acid+BMP-2 gels influenced the inflammatory response in the bone healing microenvironment. Host-derived putative mesenchymal stem cells were major contributors. Addition of hydroxyapatite nanoparticles modified the release pattern of rhBMP-2, resulting in enhanced bone formation.

The influence of gravity on the formation of amyloplasts in columella cells of Zea mays L

NASA Technical Reports Server (NTRS)

Moore, R.; Fondren, W. M.; Koon, E. C.; Wang, C. L.

1986-01-01

Columella (i.e., putative graviperceptive) cells of Zea mays seedlings grown in the microgravity of outer space allocate significantly less volume to putative statoliths (amyloplasts) than do columella cells of Earth-grown seedlings. Amyloplasts of flight-grown seedlings are significantly smaller than those of ground controls, as is the average volume of individual starch grains. Similarly, the relative volume of starch in amyloplasts in columella cells of flight-grown seedlings is significantly less than that of Earth-grown seedlings. Microgravity does not significantly alter the volume of columella cells, the average number of amyloplasts per columella cell, or the number of starch grains per amyloplast. These results are discussed relative to the influence of gravity on cellular and organellar structure.

Characterization of noncoding regulatory DNA in the human genome.

PubMed

Elkon, Ran; Agami, Reuven

2017-08-08

Genetic variants associated with common diseases are usually located in noncoding parts of the human genome. Delineation of the full repertoire of functional noncoding elements, together with efficient methods for probing their biological roles, is therefore of crucial importance. Over the past decade, DNA accessibility and various epigenetic modifications have been associated with regulatory functions. Mapping these features across the genome has enabled researchers to begin to document the full complement of putative regulatory elements. High-throughput reporter assays to probe the functions of regulatory regions have also been developed but these methods separate putative regulatory elements from the chromosome so that any effects of chromatin context and long-range regulatory interactions are lost. Definitive assignment of function(s) to putative cis-regulatory elements requires perturbation of these elements. Genome-editing technologies are now transforming our ability to perturb regulatory elements across entire genomes. Interpretation of high-throughput genetic screens that incorporate genome editors might enable the construction of an unbiased map of functional noncoding elements in the human genome.

Molecular cloning, expression and immunolocalization of a novel human cementum-derived protein (CP-23).

PubMed

Alvarez-Pérez, Marco Antonio; Narayanan, Sampath; Zeichner-David, Margarita; Rodríguez Carmona, Bruno; Arzate, Higinio

2006-03-01

Cementum is a unique mineralized connective tissue that covers the root surfaces of the teeth. The cementum is critical for appropriate maturation of the periodontium, both during development as well as that associated with regeneration of periodontal tissues, IU; however, one major impediment to understand the molecular mechanisms that regulate periodontal regeneration is the lack of cementum markers. Here we report on the identification and characterization of one such differentially human expressed gene, termed "cementum protein-23" (CP-23) that appears to be periodontal ligament and cementum-specific. We screened human cementum tumor-derived cDNA libraries by transient expression in COS-7 cells and "panning" with a rabbit polyclonal antibody against a cementoblastoma conditioned media-derived protein (CP). One isolated cDNA, CP-23, was expressed in E. coli and polyclonal antibodies against the recombinant human CP-23 were produced. Expression of CP-23 protein by cells of the periodontium was examined by Northern blot and in situ hybridization. Expression of CP-23 transcripts in human cementoblastoma-derived cells, periodontal ligament cells, human gingival fibroblasts and alveolar bone-derived cells was determined by RT-PCR. Our results show that we have isolated a 1374-bp human cDNA containing an open reading frame that encodes a polypeptide with 247 amino acid residues, with a predicted molecular mass of 25.9 kDa that represents CP species. The recombinant human CP-23 protein cross-reacted with antibodies against CP and type X collagen. Immunoscreening of human periodontal tissues revealed that CP-23 gene product is localized to the cementoid matrix of cementum and cementoblasts throughout the entire surface of the root, cell subpopulations of the periodontal ligament as well as cells located paravascularly to the blood vessels into the periodontal ligament. Furthermore, 98% of putative cementoblasts and 15% of periodontal ligament cells cultured in vitro expressed CP-23 gene product. Cementoblastoma cells and periodontal ligament cells contained a 5.0 kb CP-23 mRNA. In situ hybridization showed strong expression of CP-23 mRNA on cementoblast, cell subpopulations of the periodontal ligament and cells located around blood vessels into the periodontal ligament. Our results demonstrate that CP-23 represents a novel, tissue-specific-gene product being expressed by periodontal ligament subpopulations and cementoblasts. These findings offer the possibility to determine the cellular and molecular events that regulate the cementogenesis process during root development. Furthermore, it might provide new venues for the design of translational studies aimed at achieving predictable new cementogenesis and regeneration of the periodontal tissues.

Role played by Disabled-2 in albumin induced MAP Kinase signalling

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

Diwakar, Ramaswamy; Pearson, Alexander L.; Colville-Nash, Paul

2008-02-15

Albumin has been shown to activate the mitogen activated protein kinase (MAPK) pathway in proximal tubular cells (PTECs) of the kidney. Megalin, the putative receptor for albumin has potential signalling properties. However, the mechanisms by which megalin signals are unclear. The adaptor phosphoprotein Disabled-2 (Dab2) is known to interact with the cytoplasmic tail of megalin and may be involved in albumin-mediated MAPK signalling. In this study, we investigated the role of Dab2 in albumin-mediated MAPK signalling and further studied the role of Dab2 in albumin-induced TGF{beta}-1 secretion, a MAPK dependent event. We used RNA interference to knockdown Dab2 protein abundancemore » in HKC-8 cells a model of human PTECs. Albumin activated ERK1,2 and Elk-1 in a MEK-1 dependent manner and resulted in secretion of TGF{beta}-1. In the absence of albumin, knockdown of Dab2 resulted in a trend towards increase in pERK1,2 consistent with its putative role as an inhibitor of cell proliferation. However albumin-induced ERK1,2 activation was completely abolished by Dab2 knockdown. Dab2 knockdown did not however result in inhibition of albumin-induced TGF{beta}-1 secretion. These results suggest that Dab2 is a ligand dependent bi-directional regulator of ERK1,2 activity by demonstrating that in addition to its more traditional role as an inhibitor of ERK1,2 it may also activate ERK1,2.« less

Synthesis, structural characterization and effect on human granulocyte intracellular cAMP levels of abscisic acid analogs.

PubMed

Bellotti, Marta; Salis, Annalisa; Grozio, Alessia; Damonte, Gianluca; Vigliarolo, Tiziana; Galatini, Andrea; Zocchi, Elena; Benatti, Umberto; Millo, Enrico

2015-01-01

The phytohormone abscisic acid (ABA), in addition to regulating physiological functions in plants, is also produced and released by several mammalian cell types, including human granulocytes, where it stimulates innate immune functions via an increase of the intracellular cAMP concentration ([cAMP]i). We synthesized several ABA analogs and evaluated the structure-activity relationship, by the systematical modification of selected regions of these analogs. The resulting molecules were tested for their ability to inhibit the ABA-induced increase of [cAMP]i in human granulocytes. The analogs with modified configurations at C-2' and C-3' abrogated the ABA-induced increase of the [cAMP]i and also inhibited several pro-inflammatory effects induced by exogenous ABA on granulocytes and monocytes. Accordingly, these analogs could be suitable as novel putative anti-inflammatory compounds. Copyright © 2014 Elsevier Ltd. All rights reserved.

Multi-platform ’Omics Analysis of Human Ebola Virus Disease Pathogenesis

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

Eisfeld, Amie J.; Halfmann, Peter J.; Wendler, Jason P.

The pathogenesis of human Ebola virus disease (EVD) is complex. EVD is characterized by high levels of virus replication and dissemination, dysregulated immune responses, extensive virus- and host-mediated tissue damage, and disordered coagulation. To clarify how host responses contribute to EVD pathophysiology, we performed multi-platform ’omics analysis of peripheral blood mononuclear cells and plasma from EVD patients. Our results indicate that EVD molecular signatures overlap with those of sepsis, imply that pancreatic enzymes contribute to tissue damage in fatal EVD, and suggest that Ebola virus infection may induce aberrant neutrophils whose activity could explain hallmarks of fatal EVD. Moreover, integratedmore » biomarker prediction identified putative biomarkers from different data platforms that differentiated survivors and fatalities early after infection. This work reveals insight into EVD pathogenesis, suggests an effective approach for biomarker identification, and provides an important community resource for further analysis of human EVD severity.« less

Picornavirus Modification of a Host mRNA Decay Protein

PubMed Central

Rozovics, Janet M.; Chase, Amanda J.; Cathcart, Andrea L.; Chou, Wayne; Gershon, Paul D.; Palusa, Saiprasad; Wilusz, Jeffrey; Semler, Bert L.

2012-01-01

ABSTRACT Due to the limited coding capacity of picornavirus genomic RNAs, host RNA binding proteins play essential roles during viral translation and RNA replication. Here we describe experiments suggesting that AUF1, a host RNA binding protein involved in mRNA decay, plays a role in the infectious cycle of picornaviruses such as poliovirus and human rhinovirus. We observed cleavage of AUF1 during poliovirus or human rhinovirus infection, as well as interaction of this protein with the 5′ noncoding regions of these viral genomes. Additionally, the picornavirus proteinase 3CD, encoded by poliovirus or human rhinovirus genomic RNAs, was shown to cleave all four isoforms of recombinant AUF1 at a specific N-terminal site in vitro. Finally, endogenous AUF1 was found to relocalize from the nucleus to the cytoplasm in poliovirus-infected HeLa cells to sites adjacent to (but distinct from) putative viral RNA replication complexes. PMID:23131833

Multi-platform 'Omics Analysis of Human Ebola Virus Disease Pathogenesis.

PubMed

Eisfeld, Amie J; Halfmann, Peter J; Wendler, Jason P; Kyle, Jennifer E; Burnum-Johnson, Kristin E; Peralta, Zuleyma; Maemura, Tadashi; Walters, Kevin B; Watanabe, Tokiko; Fukuyama, Satoshi; Yamashita, Makoto; Jacobs, Jon M; Kim, Young-Mo; Casey, Cameron P; Stratton, Kelly G; Webb-Robertson, Bobbie-Jo M; Gritsenko, Marina A; Monroe, Matthew E; Weitz, Karl K; Shukla, Anil K; Tian, Mingyuan; Neumann, Gabriele; Reed, Jennifer L; van Bakel, Harm; Metz, Thomas O; Smith, Richard D; Waters, Katrina M; N'jai, Alhaji; Sahr, Foday; Kawaoka, Yoshihiro

2017-12-13

The pathogenesis of human Ebola virus disease (EVD) is complex. EVD is characterized by high levels of virus replication and dissemination, dysregulated immune responses, extensive virus- and host-mediated tissue damage, and disordered coagulation. To clarify how host responses contribute to EVD pathophysiology, we performed multi-platform 'omics analysis of peripheral blood mononuclear cells and plasma from EVD patients. Our results indicate that EVD molecular signatures overlap with those of sepsis, imply that pancreatic enzymes contribute to tissue damage in fatal EVD, and suggest that Ebola virus infection may induce aberrant neutrophils whose activity could explain hallmarks of fatal EVD. Moreover, integrated biomarker prediction identified putative biomarkers from different data platforms that differentiated survivors and fatalities early after infection. This work reveals insight into EVD pathogenesis, suggests an effective approach for biomarker identification, and provides an important community resource for further analysis of human EVD severity. Copyright © 2017 Elsevier Inc. All rights reserved.

Transcriptome analysis of Spodoptera frugiperda Sf9 cells reveals putative apoptosis-related genes and a preliminary apoptosis mechanism induced by azadirachtin.

PubMed

Shu, Benshui; Zhang, Jingjing; Sethuraman, Veeran; Cui, Gaofeng; Yi, Xin; Zhong, Guohua

2017-10-16

As an important botanical pesticide, azadirachtin demonstrates broad insecticidal activity against many agricultural pests. The results of a previous study indicated the toxicity and apoptosis induction of azadirachtin in Spodoptera frugiperda Sf9 cells. However, the lack of genomic data has hindered a deeper investigation of apoptosis in Sf9 cells at a molecular level. In the present study, the complete transcriptome data for Sf9 cell line was accomplished using Illumina sequencing technology, and 97 putative apoptosis-related genes were identified through BLAST and KEGG orthologue annotations. Fragments of potential candidate apoptosis-related genes were cloned, and the mRNA expression patterns of ten identified genes regulated by azadirachtin were examined using qRT-PCR. Furthermore, Western blot analysis showed that six putative apoptosis-related proteins were upregulated after being treated with azadirachtin while the protein Bcl-2 were downregulated. These data suggested that both intrinsic and extrinsic apoptotic signal pathways comprising the identified potential apoptosis-related genes were potentially active in S. frugiperda. In addition, the preliminary results revealed that caspase-dependent or caspase-independent apoptotic pathways could function in azadirachtin-induced apoptosis in Sf9 cells.

Dynamic Modulation of Expression of Lentiviral Restriction Factors in Primary CD4+ T Cells following Simian Immunodeficiency Virus Infection.

PubMed

Rahmberg, Andrew R; Rajakumar, Premeela A; Billingsley, James M; Johnson, R Paul

2017-04-01

Although multiple restriction factors have been shown to inhibit HIV/SIV replication, little is known about their expression in vivo Expression of 45 confirmed and putative HIV/SIV restriction factors was analyzed in CD4 + T cells from peripheral blood and the jejunum in rhesus macaques, revealing distinct expression patterns in naive and memory subsets. In both peripheral blood and the jejunum, memory CD4 + T cells expressed higher levels of multiple restriction factors compared to naive cells. However, relative to their expression in peripheral blood CD4 + T cells, jejunal CCR5 + CD4 + T cells exhibited significantly lower expression of multiple restriction factors, including APOBEC3G , MX2 , and TRIM25 , which may contribute to the exquisite susceptibility of these cells to SIV infection. In vitro stimulation with anti-CD3/CD28 antibodies or type I interferon resulted in upregulation of distinct subsets of multiple restriction factors. After infection of rhesus macaques with SIVmac239, the expression of most confirmed and putative restriction factors substantially increased in all CD4 + T cell memory subsets at the peak of acute infection. Jejunal CCR5 + CD4 + T cells exhibited the highest levels of SIV RNA, corresponding to the lower restriction factor expression in this subset relative to peripheral blood prior to infection. These results illustrate the dynamic modulation of confirmed and putative restriction factor expression by memory differentiation, stimulation, tissue microenvironment and SIV infection and suggest that differential expression of restriction factors may play a key role in modulating the susceptibility of different populations of CD4 + T cells to lentiviral infection. IMPORTANCE Restriction factors are genes that have evolved to provide intrinsic defense against viruses. HIV and simian immunodeficiency virus (SIV) target CD4 + T cells. The baseline level of expression in vivo and degree to which expression of restriction factors is modulated by conditions such as CD4 + T cell differentiation, stimulation, tissue location, or SIV infection are currently poorly understood. We measured the expression of 45 confirmed and putative restriction factors in primary CD4 + T cells from rhesus macaques under various conditions, finding dynamic changes in each state. Most dramatically, in acute SIV infection, the expression of almost all target genes analyzed increased. These are the first measurements of many of these confirmed and putative restriction factors in primary cells or during the early events after SIV infection and suggest that the level of expression of restriction factors may contribute to the differential susceptibility of CD4 + T cells to SIV infection. Copyright © 2017 American Society for Microbiology.

In silico Prediction, in vitro Antibacterial Spectrum, and Physicochemical Properties of a Putative Bacteriocin Produced by Lactobacillus rhamnosus Strain L156.4

PubMed Central

Oliveira, Letícia de C.; Silveira, Aline M. M.; Monteiro, Andréa de S.; dos Santos, Vera L.; Nicoli, Jacques R.; Azevedo, Vasco A. de C.; Soares, Siomar de C.; Dias-Souza, Marcus V.; Nardi, Regina M. D.

2017-01-01

A bacteriocinogenic Lactobacillus rhamnosus L156.4 strain isolated from the feces of NIH mice was identified by 16S rRNA gene sequencing and MALDI-TOF mass spectrometry. The entire genome was sequenced using Illumina, annotated in the PGAAP, and RAST servers, and deposited. Conserved genes associated with bacteriocin synthesis were predicted using BAGEL3, leading to the identification of an open reading frame (ORF) that shows homology with the L. rhamnosus GG (ATCC 53103) prebacteriocin gene. The encoded protein contains a conserved protein motif associated a structural gene of the Enterocin A superfamily. We found ORFs related to the prebacteriocin, immunity protein, ABC transporter proteins, and regulatory genes with 100% identity to those of L. rhamnosus HN001. In this study, we provide evidence of a putative bacteriocin produced by L. rhamnosus L156.4 that was further confirmed by in vitro assays. The antibacterial activity of the substances produced by this strain was evaluated using the deferred agar-spot and spot-on-the lawn assays, and a wide antimicrobial activity spectrum against human and foodborne pathogens was observed. The physicochemical characterization of the putative bacteriocin indicated that it was sensitive to proteolytic enzymes, heat stable and maintained its antibacterial activity in a pH ranging from 3 to 9. The activity against Lactobacillus fermentum, which was used as an indicator strain, was detected during bacterial logarithmic growth phase, and a positive correlation was confirmed between bacterial growth and production of the putative bacteriocin. After a partial purification from cell-free supernatant by salt precipitation, the putative bacteriocin migrated as a diffuse band of approximately 1.0–3.0 kDa by SDS-PAGE. Additional studies are being conducted to explore its use in the food industry for controlling bacterial growth and for probiotic applications. PMID:28579977

Protein kinase C epsilon mediates the inhibition of angiotensin II on the slowly activating delayed-rectifier potassium current through channel phosphorylation.

PubMed

Gou, Xiangbo; Wang, Wenying; Zou, Sihao; Qi, Yajuan; Xu, Yanfang

2018-03-01

The slowly activating delayed rectifier K + current (I Ks ) is one of the main repolarizing currents in the human heart. Evidence has shown that angiotensin II (Ang II) regulates I Ks through the protein kinase C (PKC) pathway, but the related results are controversial. This study was designed to identify PKC isoenzymes involved in the regulation of I Ks by Ang II and the underlying molecular mechanism. The whole-cell patch-clamp technique was used to record I Ks in isolated guinea pig ventricular cardiomyocytes and in human embryonic kidney (HEK) 293 cells co-transfected with human KCNQ1/KCNE1 genes and Ang II type 1 receptor genes. Ang II inhibited I Ks in a concentration-dependent manner in native cardiomyocytes. A broad PKC inhibitor Gö6983 (not inhibiting PKCε) and a selective cPKC inhibitor Gö6976 did not affect the inhibitory action of Ang II. In contrast, the inhibition was significantly attenuated by PKCε-selective peptide inhibitor εV1-2. However, direct activation of PKC by phorbol 12-myristate 13-acetate (PMA) increased the cloned human I Ks in HEK293 cells. Similarly, the cPKC peptide activator significantly enhanced the current. In contrast, the PKCε peptide activator inhibited the current. Further evidence showed that PKCε knockdown by siRNA antagonized the Ang II-induced inhibition on KCNQ1/KCNE1 current, whereas knockdown of cPKCs (PKCα and PKCβ) attenuated the potentiation of the current by PMA. Moreover, deletion of four putative phosphorylation sites in the C-terminus of KCNQ1 abolished the action of PMA. Mutation of two putative phosphorylation sites in the N-terminus of KCNQ1 and one site in KCNE1 (S102) blocked the inhibition of Ang II. Our results demonstrate that PKCε isoenzyme mediates the inhibitory action of Ang II on I Ks and by phosphorylating distinct sites in KCNQ1/KCNE1, cPKC and PKCε isoenzymes produce the contrary regulatory effects on the channel. These findings have provided new insight into the molecular mechanism underlying the modulation of the KCNQ1/KCNE1 channel. Copyright © 2018 Elsevier Ltd. All rights reserved.

CXCR6 identifies a putative population of retained human lung T cells characterised by co-expression of activation markers.

PubMed

Morgan, Angela J; Guillen, Cristina; Symon, Fiona A; Birring, Surinder S; Campbell, James J; Wardlaw, Andrew J

2008-01-01

Expressions of activation markers have been described on the surface of T cells in the blood and the lung in both health and disease. We have studied the distribution of activation markers on human lung T cells and have found that only certain populations exist. Importantly, the presence or absence of some markers appears to predict those of others, in particular cells which express CD103 also express CD49a and CD69, whereas cells which do not express CD69 also do not express CD49a or CD103. In view of the paucity of activation marker expression in the peripheral blood, we have hypothesised that these CD69+, CD49a+, and CD103+ (triple positive) cells are retained in the lung, possess effector function (IFNgamma secretion) and express particular chemokine receptors which allow them to be maintained in this environment. We have found that the ability of the triple negative cells to secrete IFNgamma is significantly less than the triple positive cells, suggesting that the expression of activation markers can highlight a highly specialised effector cell. We have studied the expression of 14 chemokine receptors and have found that the most striking difference between the triple negative cells and the triple positive cells is the expression of CXCR6 with 12.8+/-9.8% of triple negative cells expressing CXCR6 compared to 89.5+/-5.5% of triple positive cells. We propose therefore that CXCR6 may play an important role in the retention of T cells within the lung.

Structural domains required for channel function of the mouse transient receptor potential protein homologue TRP1beta.

PubMed

Engelke, Michael; Friedrich, Olaf; Budde, Petra; Schäfer, Christina; Niemann, Ursula; Zitt, Christof; Jüngling, Eberhard; Rocks, Oliver; Lückhoff, Andreas; Frey, Jürgen

2002-07-17

Transient receptor potential proteins (TRP) are supposed to participate in the formation of store-operated Ca(2+) influx channels by co-assembly. However, little is known which domains facilitate the interaction of subunits. Contribution of the N-terminal coiled-coil domain and ankyrin-like repeats and the putative pore region of the mouse TRP1beta (mTRP1beta) variant to the formation of functional cation channels were analyzed following overexpression in HEK293 (human embryonic kidney) cells. MTRP1beta expressing cells exhibited enhanced Ca(2+) influx and enhanced whole-cell membrane currents compared to mTRP1beta deletion mutants. Using a yeast two-hybrid assay only the coiled-coil domain facilitated homodimerization of the N-terminus. These results suggest that the N-terminus of mTRP1beta is required for structural organization thus forming functional channels.

Noninvasive in situ evaluation of osteogenic differentiation by time-resolved laser-induced fluorescence spectroscopy.

PubMed

Ashjian, Peter; Elbarbary, Amir; Zuk, Patricia; DeUgarte, Daniel A; Benhaim, Prosper; Marcu, Laura; Hedrick, Marc H

2004-01-01

The clinical implantation of bioengineered tissues requires an in situ nondestructive evaluation of the quality of tissue constructs developed in vitro before transplantation. Time-resolved laser-induced fluorescence spectroscopy (TR-LIFS) is demonstrated here to noninvasively monitor the formation of osteogenic extracellular matrix (ECM) produced by putative stem cells (PLA cells) derived from human adipose tissue. We show that this optical spectroscopy technique can assess the relative expression of collagens (types I, III, IV, and V) within newly forming osteogenic ECM. The results are consistent with those obtained by conventional histochemical techniques (immunofluorescence and Western blot) and demonstrate that TR-LIFS is a potential tool for monitoring the expression of distinct collagen types and the formation of collagen cross-links in intact tissue constructs.

Suppression of Peroxiredoxin 4 in Glioblastoma Cells Increases Apoptosis and Reduces Tumor Growth

PubMed Central

Kim, Tae Hyong; Song, Jieun; Alcantara Llaguno, Sheila R.; Murnan, Eric; Liyanarachchi, Sandya; Palanichamy, Kamalakannan; Yi, Ji-Yeun; Viapiano, Mariano Sebastian; Nakano, Ichiro; Yoon, Sung Ok; Wu, Hong; Parada, Luis F.; Kwon, Chang-Hyuk

2012-01-01

Glioblastoma multiforme (GBM), the most common and aggressive primary brain malignancy, is incurable despite the best combination of current cancer therapies. For the development of more effective therapies, discovery of novel candidate tumor drivers is urgently needed. Here, we report that peroxiredoxin 4 (PRDX4) is a putative tumor driver. PRDX4 levels were highly increased in a majority of human GBMs as well as in a mouse model of GBM. Reducing PRDX4 expression significantly decreased GBM cell growth and radiation resistance in vitro with increased levels of ROS, DNA damage, and apoptosis. In a syngenic orthotopic transplantation model, Prdx4 knockdown limited GBM infiltration and significantly prolonged mouse survival. These data suggest that PRDX4 can be a novel target for GBM therapies in the future. PMID:22916164

Exogenous fatty acid binding protein 4 promotes human prostate cancer cell progression.

PubMed

Uehara, Hisanori; Takahashi, Tetsuyuki; Oha, Mina; Ogawa, Hirohisa; Izumi, Keisuke

2014-12-01

Epidemiologic studies have found that obesity is associated with malignant grade and mortality in prostate cancer. Several adipokines have been implicated as putative mediating factors between obesity and prostate cancer. Fatty acid binding protein 4 (FABP4), a member of the cytoplasmic fatty acid binding protein multigene family, was recently identified as a novel adipokine. Although FABP4 is released from adipocytes and mean circulating concentrations of FABP4 are linked with obesity, effects of exogenous FABP4 on prostate cancer progression are unclear. In this study, we examined the effects of exogenous FABP4 on human prostate cancer cell progression. FABP4 treatment promoted serum-induced prostate cancer cell invasion in vitro. Furthermore, oleic acid promoted prostate cancer cell invasion only if FABP4 was present in the medium. These promoting effects were reduced by FABP4 inhibitor, which inhibits FABP4 binding to fatty acids. Immunostaining for FABP4 showed that exogenous FABP4 was taken up into DU145 cells in three-dimensional culture. In mice, treatment with FABP4 inhibitor reduced the subcutaneous growth and lung metastasis of prostate cancer cells. Immunohistochemical analysis showed that the number of apoptotic cells, positive for cleaved caspase-3 and cleaved PARP, was increased in subcutaneous tumors of FABP4 inhibitor-treated mice, as compared with control mice. These results suggest that exogenous FABP4 might promote human prostate cancer cell progression by binding with fatty acids. Additionally, exogenous FABP4 activated the PI3K/Akt pathway, independently of binding to fatty acids. Thus, FABP4 might be a key molecule to understand the mechanisms underlying the obesity-prostate cancer progression link. © 2014 UICC.

In vitro antineoplastic effects of brivaracetam and lacosamide on human glioma cells.

PubMed

Rizzo, Ambra; Donzelli, Sara; Girgenti, Vita; Sacconi, Andrea; Vasco, Chiara; Salmaggi, Andrea; Blandino, Giovanni; Maschio, Marta; Ciusani, Emilio

2017-06-06

Epilepsy is a frequent symptom in patients with glioma. Although treatment with antiepileptic drugs is generally effective in controlling seizures, drug-resistant patients are not uncommon. Multidrug resistance proteins (MRPs) and P-gp are over-represented in brain tissue of patients with drug-resistant epilepsy, suggesting their involvement in the clearance of antiepileptic medications. In addition to their anticonvulsant action, some drugs have been documented for cytotoxic effects. Aim of this study was to evaluate possible in vitro cytotoxic effects of two new-generation antiepileptic drugs on a human glioma cell line U87MG. Cytotoxicity of brivaracetam and lacosamide was tested on U87MG, SW1783 and T98G by MTS assay. Expression of chemoresistance molecules was evaluated using flow cytometry in U87MG and human umbilical vein endothelial cells (HUVECs). To investigate the putative anti-proliferative effect, apoptosis assay, microRNA expression profile and study of cell cycle were performed. Brivaracetam and lacosamide showed a dose-dependent cytotoxic and anti-migratory effects. Cytotoxicity was not related to apoptosis. The exposure of glioma cells to brivaracetam and lacosamide resulted in the modulation of several microRNAs; particularly, the effect of miR-195-5p modulation seemed to affect cell cycle, while miR-107 seemed to be implicated in the inhibition of cells migration. Moreover, brivaracetam and lacosamide treatment did not modulate the expression of chemoresistance-related molecules MRPs1-3-5, GSTπ, P-gp on U87MG and HUVECs. Based on antineoplastic effect of brivaracetam and lacosamide on glioma cells, we assume that patients with glioma could benefit by the treatment with these two molecules, in addition to standard therapeutic options.

Differential Gene Expression in Normal Human Mammary Epithelial Cells Treated with Malathion Monitored by DNA Microarrays

PubMed Central

Gwinn, Maureen R.; Whipkey, Diana L.; Tennant, Lora B.; Weston, Ainsley

2005-01-01

Organophosphate pesticides are a major source of occupational exposure in the United States. Moreover, malathion has been sprayed over major urban populations in an effort to control mosquitoes carrying West Nile virus. Previous research, reviewed by the U.S. Environmental Protection Agency, on the genotoxicity and carcinogenicity of malathion has been inconclusive, although malathion is a known endocrine disruptor. Here, interindividual variations and commonality of gene expression signatures have been studied in normal human mammary epithelial cells from four women undergoing reduction mammoplasty. The cell strains were obtained from the discarded tissues through the Cooperative Human Tissue Network (sponsors: National Cancer Institute and National Disease Research Interchange). Interindividual variation of gene expression patterns in response to malathion was observed in various clustering patterns for the four cell strains. Further clustering identified three genes with increased expression after treatment in all four cell strains. These genes were two aldo–keto reductases (AKR1C1 and AKR1C2) and an estrogen-responsive gene (EBBP). Decreased expression of six RNA species was seen at various time points in all cell strains analyzed: plasminogen activator (PLAT), centromere protein F (CPF), replication factor C (RFC3), thymidylate synthetase (TYMS), a putative mitotic checkpoint kinase (BUB1), and a gene of unknown function (GenBank accession no. AI859865). Expression changes in all these genes, detected by DNA microarrays, have been verified by real-time polymerase chain reaction. Differential changes in expression of these genes may yield biomarkers that provide insight into interindividual variation in malathion toxicity. PMID:16079077

Dual Role of Endothelial Nitric Oxide Synthase in Oxidized LDL-Induced, p66Shc-Mediated Oxidative Stress in Cultured Human Endothelial Cells

PubMed Central

Shi, Yi; Lüscher, Thomas F.; Camici, Giovanni G.

2014-01-01

Background The aging gene p66Shc, is an important mediator of oxidative stress-induced vascular dysfunction and disease. In cultured human aortic endothelial cells (HAEC), p66Shc deletion increases endothelial nitric oxide synthase (eNOS) expression and nitric oxide (NO) bioavailability via protein kinase B. However, the putative role of the NO pathway on p66Shc activation remains unclear. This study was designed to elucidate the regulatory role of the eNOS/NO pathway on p66Shc activation. Methods and Results Incubation of HAEC with oxidized low density lipoprotein (oxLDL) led to phosphorylation of p66Shc at Ser-36, resulting in an enhanced production of superoxide anion (O2 -). In the absence of oxLDL, inhibition of eNOS by small interfering RNA or L-NAME, induced p66Shc phosphorylation, suggesting that basal NO production inhibits O2 - production. oxLDL-induced, p66Shc-mediated O2- was prevented by eNOS inhibition, suggesting that when cells are stimulated with oxLDL eNOS is a source of reactive oxygen species. Endogenous or exogenous NO donors, prevented p66Shc activation and reduced O2- production. Treatment with tetrahydrobiopterin, an eNOS cofactor, restored eNOS uncoupling, prevented p66Shc activation, and reduced O2- generation. However, late treatment with tetrahydropterin did not yield the same result suggesting that eNOS uncoupling is the primary source of reactive oxygen species. Conclusions The present study reports that in primary cultured HAEC treated with oxLDL, p66Shc-mediated oxidative stress is derived from eNOS uncoupling. This finding contributes novel information on the mechanisms of p66Shc activation and its dual interaction with eNOS underscoring the importance eNOS uncoupling as a putative antioxidant therapeutical target in endothelial dysfunction as observed in cardiovascular disease. PMID:25247687

Dual role of endothelial nitric oxide synthase in oxidized LDL-induced, p66Shc-mediated oxidative stress in cultured human endothelial cells.

PubMed

Shi, Yi; Lüscher, Thomas F; Camici, Giovanni G

2014-01-01

The aging gene p66Shc, is an important mediator of oxidative stress-induced vascular dysfunction and disease. In cultured human aortic endothelial cells (HAEC), p66Shc deletion increases endothelial nitric oxide synthase (eNOS) expression and nitric oxide (NO) bioavailability via protein kinase B. However, the putative role of the NO pathway on p66Shc activation remains unclear. This study was designed to elucidate the regulatory role of the eNOS/NO pathway on p66Shc activation. Incubation of HAEC with oxidized low density lipoprotein (oxLDL) led to phosphorylation of p66Shc at Ser-36, resulting in an enhanced production of superoxide anion (O2-). In the absence of oxLDL, inhibition of eNOS by small interfering RNA or L-NAME, induced p66Shc phosphorylation, suggesting that basal NO production inhibits O2- production. oxLDL-induced, p66Shc-mediated O2- was prevented by eNOS inhibition, suggesting that when cells are stimulated with oxLDL eNOS is a source of reactive oxygen species. Endogenous or exogenous NO donors, prevented p66Shc activation and reduced O2- production. Treatment with tetrahydrobiopterin, an eNOS cofactor, restored eNOS uncoupling, prevented p66Shc activation, and reduced O2- generation. However, late treatment with tetrahydropterin did not yield the same result suggesting that eNOS uncoupling is the primary source of reactive oxygen species. The present study reports that in primary cultured HAEC treated with oxLDL, p66Shc-mediated oxidative stress is derived from eNOS uncoupling. This finding contributes novel information on the mechanisms of p66Shc activation and its dual interaction with eNOS underscoring the importance eNOS uncoupling as a putative antioxidant therapeutical target in endothelial dysfunction as observed in cardiovascular disease.

Topography of the Human Papillomavirus Minor Capsid Protein L2 during Vesicular Trafficking of Infectious Entry.

PubMed

DiGiuseppe, Stephen; Keiffer, Timothy R; Bienkowska-Haba, Malgorzata; Luszczek, Wioleta; Guion, Lucile G M; Müller, Martin; Sapp, Martin

2015-10-01

The human papillomavirus (HPV) capsid is composed of the major capsid protein L1 and the minor capsid protein L2. During entry, the HPV capsid undergoes numerous conformational changes that result in endosomal uptake and subsequent trafficking of the L2 protein in complex with the viral DNA to the trans-Golgi network. To facilitate this transport, the L2 protein harbors a number of putative motifs that, if capable of direct interaction, would interact with cytosolic host cell factors. These data imply that a portion of L2 becomes cytosolic during infection. Using a low concentration of digitonin to selectively permeabilize the plasma membrane of infected cells, we mapped the topography of the L2 protein during infection. We observed that epitopes within amino acid residues 64 to 81 and 163 to 170 and a C-terminal tag of HPV16 L2 are exposed on the cytosolic side of intracellular membranes, whereas an epitope within residues 20 to 38, which are upstream of a putative transmembrane region, is luminal. Corroborating these findings, we also found that L2 protein is sensitive to trypsin digestion during infection. These data demonstrate that the majority of the L2 protein becomes accessible on the cytosolic side of intracellular membranes in order to interact with cytosolic factors to facilitate vesicular trafficking. In order to complete infectious entry, nonenveloped viruses have to pass cellular membranes. This is often achieved through the viral capsid protein associating with or integrating into intracellular membrane. Here, we determine the topography of HPV L2 protein in the endocytic vesicular compartment, suggesting that L2 becomes a transmembrane protein with a short luminal portion and with the majority facing the cytosolic side for interaction with host cell transport factors. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

An in silico pipeline to filter the Toxoplasma gondii proteome for proteins that could traffic to the host cell nucleus and influence host cell epigenetic regulation.

PubMed

Syn, Genevieve; Blackwell, Jenefer M; Jamieson, Sarra E; Francis, Richard W

2018-01-01

Toxoplasma gondii uses epigenetic mechanisms to regulate both endogenous and host cell gene expression. To identify genes with putative epigenetic functions, we developed an in silico pipeline to interrogate the T. gondii proteome of 8313 proteins. Step 1 employs PredictNLS and NucPred to identify genes predicted to target eukaryotic nuclei. Step 2 uses GOLink to identify proteins of epigenetic function based on Gene Ontology terms. This resulted in 611 putative nuclear localised proteins with predicted epigenetic functions. Step 3 filtered for secretory proteins using SignalP, SecretomeP, and experimental data. This identified 57 of the 611 putative epigenetic proteins as likely to be secreted. The pipeline is freely available online, uses open access tools and software with user-friendly Perl scripts to automate and manage the results, and is readily adaptable to undertake any such in silico search for genes contributing to particular functions.

Testicular cell conditioned medium supports differentiation of embryonic stem cells into ovarian structures containing oocytes.

PubMed

Lacham-Kaplan, Orly; Chy, Hun; Trounson, Alan

2006-02-01

Previous reports and the current study have found that germ cell precursor cells appear in embryoid bodies (EBs) formed from mouse embryonic stem cells as identified by positive expression of specific germ cell markers such as Oct-3/4, Mvh, c-kit, Stella, and DAZL. We hypothesized that if exposed to appropriate growth factors, the germ cell precursor cells within the EBs would differentiate into gametes. The source for growth factors used in the present study is conditioned medium collected from testicular cell cultures prepared from the testes of newborn males. Testes at this stage of development contain most growth factors required for the transformation of germ stem cells into differentiated gametes. When EBs were cultured in the conditioned medium, they developed into ovarian structures, which contained putative oocytes. The oocytes were surrounded by one to two layers of flattened cells and did not have a visible zona pellucida. However, oocyte-specific markers such as Fig-alpha and ZP3 were found expressed by the ovarian structures. The production of oocytes using this method is repeatable and reliable and may be applicable to other mammalian species, including the human.

miR-137 inhibits the proliferation of human non-small cell lung cancer cells by targeting SRC3

PubMed Central

Chen, Ruilin; Zhang, Yongqing; Zhang, Chengcheng; Wu, Hua; Yang, Shumei

2017-01-01

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer. The results of the present study demonstrate that high expression of microRNA (miR)-137 and low expression of steroid receptor coactivator-3 (SRC3) had a significant negative correlation in 40 NSCLC tissue samples. In addition, cell colony formation and proliferation was significantly reduced in miR-137-transfected A549 and NCI-H838 cells compared with scramble-transfected NSCLC cell lines. miR-137 was identified to induce G1/S cell cycle arrest and dysregulate the mRNA expression of cell cycle-associated proteins (proliferating cell nuclear antigen, cyclin E, cyclin A1, cyclin A2 and p21) in NSCLC cells. Notably, miR-137 could significantly suppress SRC3 3′ untranslated region (UTR) luciferase-reporter activity, an effect that was not detectable when the putative 3′-UTR target-site was mutated, further clarifying the molecular mechanisms underlying the role of miR-137 in NSCLC. In conclusion, the results of the present study suggest that miR-137 suppresses NSCLC cell proliferation by partially targeting SRC3. PMID:28521488

Integrated Transcriptomic and Epigenomic Analysis of Primary Human Lung Epithelial Cell Differentiation

PubMed Central

Marconett, Crystal N.; Zhou, Beiyun; Rieger, Megan E.; Selamat, Suhaida A.; Dubourd, Mickael; Fang, Xiaohui; Lynch, Sean K.; Stueve, Theresa Ryan; Siegmund, Kimberly D.; Berman, Benjamin P.

2013-01-01

Elucidation of the epigenetic basis for cell-type specific gene regulation is key to gaining a full understanding of how the distinct phenotypes of differentiated cells are achieved and maintained. Here we examined how epigenetic changes are integrated with transcriptional activation to determine cell phenotype during differentiation. We performed epigenomic profiling in conjunction with transcriptomic profiling using in vitro differentiation of human primary alveolar epithelial cells (AEC). This model recapitulates an in vivo process in which AEC transition from one differentiated cell type to another during regeneration following lung injury. Interrogation of histone marks over time revealed enrichment of specific transcription factor binding motifs within regions of changing chromatin structure. Cross-referencing of these motifs with pathways showing transcriptional changes revealed known regulatory pathways of distal alveolar differentiation, such as the WNT and transforming growth factor beta (TGFB) pathways, and putative novel regulators of adult AEC differentiation including hepatocyte nuclear factor 4 alpha (HNF4A), and the retinoid X receptor (RXR) signaling pathways. Inhibition of the RXR pathway confirmed its functional relevance for alveolar differentiation. Our incorporation of epigenetic data allowed specific identification of transcription factors that are potential direct upstream regulators of the differentiation process, demonstrating the power of this approach. Integration of epigenomic data with transcriptomic profiling has broad application for the identification of regulatory pathways in other models of differentiation. PMID:23818859

Bile Stress Response in Listeria monocytogenes LO28: Adaptation, Cross-Protection, and Identification of Genetic Loci Involved in Bile Resistance

PubMed Central

Begley, Máire; Gahan, Cormac G. M.; Hill, Colin

2002-01-01

Bile is one of many barriers that Listeria monocytogenes must overcome in the human gastrointestinal tract in order to infect and cause disease. We demonstrated that stationary-phase cultures of L. monocytogenes LO28 were able to tolerate concentrations of bovine, porcine, and human bile and bile acids well in excess of those encountered in vivo. Strain LO28 was relatively bile resistant compared with other clinical isolates of L. monocytogenes, as well as with Listeria innocua, Salmonella enterica serovar Typhimurium LT2, and Lactobacillus sakei. While exponential-phase L. monocytogenes LO28 cells were exquisitely sensitive to unconjugated bile acids, prior adaptation to sublethal levels of bile acids or heterologous stresses, such as acid, heat, salt, or sodium dodecyl sulfate (SDS), significantly enhanced bile resistance. This adaptive response was independent of protein synthesis, and in the cases of bile and SDS adaptation, occurred in seconds. In order to identify genetic loci involved in the bile tolerance phenotype of L. monocytogenes LO28, transposon (Tn917) and plasmid (pORI19) integration banks were screened for bile-sensitive mutants. The disrupted genes included a homologue of the capA locus required for capsule formation in Bacillus anthracis; a gene encoding the transcriptional regulator ZurR; a homologue of an Escherichia coli gene, lytB, involved in isoprenoid biosynthesis; a gene encoding a homologue of the Bacillus subtilis membrane protein YxiO; and a gene encoding an amino acid transporter with a putative role in pH homeostasis, gadE. Interestingly, all of the identified loci play putative roles in maintenance of the cell envelope or in stress responses. PMID:12450822

HER2-specific T cells target primary glioblastoma stem cells and induce regression of autologous experimental tumors.

PubMed

Ahmed, Nabil; Salsman, Vita S; Kew, Yvonne; Shaffer, Donald; Powell, Suzanne; Zhang, Yi J; Grossman, Robert G; Heslop, Helen E; Gottschalk, Stephen

2010-01-15

Glioblastoma multiforme (GBM) is the most aggressive human primary brain tumor and is currently incurable. Immunotherapies have the potential to target GBM stem cells, which are resistant to conventional therapies. Human epidermal growth factor receptor 2 (HER2) is a validated immunotherapy target, and we determined if HER2-specific T cells can be generated from GBM patients that will target autologous HER2-positive GBMs and their CD133-positive stem cell compartment. HER2-specific T cells from 10 consecutive GBM patients were generated by transduction with a retroviral vector encoding a HER2-specific chimeric antigen receptor. The effector function of HER2-specific T cells against autologous GBM cells, including CD133-positive stem cells, was evaluated in vitro and in an orthotopic murine xenograft model. Stimulation of HER2-specific T cells with HER2-positive autologous GBM cells resulted in T-cell proliferation and secretion of IFN-gamma and interleukin-2 in a HER2-dependent manner. Patients' HER2-specific T cells killed CD133-positive and CD133-negative cells derived from primary HER2-positive GBMs, whereas HER2-negative tumor cells were not killed. Injection of HER2-specific T cells induced sustained regression of autologous GBM xenografts established in the brain of severe combined immunodeficient mice. Gene transfer allows the reliable generation of HER2-specific T cells from GBM patients, which have potent antitumor activity against autologous HER2-positive tumors including their putative stem cells. Hence, the adoptive transfer of HER2-redirected T cells may be a promising immunotherapeutic approach for GBM.

The putative oncotarget CSN5 controls a transcription-uncorrelated p53-mediated autophagy implicated in cancer cell survival under curcumin treatment

PubMed Central

Sheng, Ji-Po; Yu, Fang; Tan, Ren-Xiang; Pan, Ying; Huang, Jun-Jian; Kong, Ling-Dong

2016-01-01

Curcumin has shown promise as a safe and specific anticancer agent. The COP9 signalosome (CSN) component CSN5, a known specific target for curcumin, can control p53 stability by increasing its degradation through ubiquitin system. But the correlation of CSN5-controlled p53 to anticancer therapeutic effect of curcumin is currently unknown. Here we showed that CSN5-controlled p53 was transcriptional inactive and responsible for autophagy in human normal BJ cells and cancer HepG2 cells under curcumin treatment. Of note, CSN5-initiated cellular autophagy by curcumin treatment was abolished in p53-null HCT116p53−/− cancer cells, which could be rescued by reconstitution with wild-type p53 or transcription inactive p53 mutant p53R273H. Furthermore, CSN5-controlled p53 conferred a pro-survival autophagy in diverse cancer cells response to curcumin. Genetic p53 deletion, as well as autophagy pharmacological inhibition by chloroquine, significantly enhanced the therapeutic effect of curcumin on cancer cells in vitro and in vivo, but not normal cells. This study identifies a novel CSN5-controlled p53 in autophagy of human cells. The p53 expression state is a useful biomarker for predicting the anticancer therapeutic effect of curcumin. Therefore, the pharmacologic autophagy manipulation may benefit the ongoing anticancer clinical trials of curcumin. PMID:27626169

Prevention of the degeneration of human dopaminergic neurons in an astrocyte co-culture system allowing endogenous drug metabolism

PubMed Central

Efremova, Liudmila; Schildknecht, Stefan; Adam, Martina; Pape, Regina; Gutbier, Simon; Hanf, Benjamin; Bürkle, Alexander; Leist, Marcel

2015-01-01

Background and Purpose Few neuropharmacological model systems use human neurons. Moreover, available test systems rarely reflect functional roles of co-cultured glial cells. There is no human in vitro counterpart of the widely used 1-methyl-4-phenyl-tetrahydropyridine (MPTP) mouse model of Parkinson's disease Experimental Approach We generated such a model by growing an intricate network of human dopaminergic neurons on a dense layer of astrocytes. In these co-cultures, MPTP was metabolized to 1-methyl-4-phenyl-pyridinium (MPP+) by the glial cells, and the toxic metabolite was taken up through the dopamine transporter into neurons. Cell viability was measured biochemically and by quantitative neurite imaging, siRNA techniques were also used. Key Results We initially characterized the activation of PARP. As in mouse models, MPTP exposure induced (poly-ADP-ribose) synthesis and neurodegeneration was blocked by PARP inhibitors. Several different putative neuroprotectants were then compared in mono-cultures and co-cultures. Rho kinase inhibitors worked in both models; CEP1347, ascorbic acid or a caspase inhibitor protected mono-cultures from MPP+ toxicity, but did not protect co-cultures, when used alone or in combination. Application of GSSG prevented degeneration in co-cultures, but not in mono-cultures. The surprisingly different pharmacological profiles of the models suggest that the presence of glial cells, and the in situ generation of the toxic metabolite MPP+ within the layered cultures played an important role in neuroprotection. Conclusions and Implications Our new model system is a closer model of human brain tissue than conventional cultures. Its use for screening of candidate neuroprotectants may increase the predictiveness of a test battery. PMID:25989025

Non-senescent Hydra tolerates severe disturbances in the nuclear lamina.

PubMed

Klimovich, Alexander; Rehm, Arvid; Wittlieb, Jörg; Herbst, Eva-Maria; Benavente, Ricardo; Bosch, Thomas C G

2018-05-10

The cnidarian Hydra is known for its unlimited lifespan and non-senescence, due to the indefinite self-renewal capacity of its stem cells. While proteins of the Lamin family are recognized as critical factors affecting senescence and longevity in human and mice, their putative role in the extreme longevity and non-senescence in long-living animals remains unknown. Here we analyze the role of a single lamin protein in non-senescence of Hydra . We demonstrate that proliferation of stem cells in Hydra is robust against the disturbance of Lamin expression and localization. While Lamin is indispensable for Hydra , the stem cells tolerate overexpression, downregulation and mislocalization of Lamin, and disturbances in the nuclear envelope structure. This extraordinary robustness may underlie the indefinite self-renewal capacity of stem cells and the non-senescence of Hydra . A relatively low complexity of the nuclear envelope architecture in basal Metazoa might allow for their extreme lifespans, while an increasing complexity of the nuclear architecture in bilaterians resulted in restricted lifespans.

Putative oncogene Brachyury (T) is essential to specify cell fate but dispensable for notochord progenitor proliferation and EMT.

PubMed

Zhu, Jianjian; Kwan, Kin Ming; Mackem, Susan

2016-04-05

The transcription factor Brachyury (T) gene is expressed throughout primary mesoderm (primitive streak and notochord) during early embryonic development and has been strongly implicated in the genesis of chordoma, a sarcoma of notochord cell origin. Additionally, T expression has been found in and proposed to play a role in promoting epithelial-mesenchymal transition (EMT) in various other types of human tumors. However, the role of T in normal mammalian notochord development and function is still not well-understood. We have generated an inducible knockdown model to efficiently and selectively deplete T from notochord in mouse embryos. In combination with genetic lineage tracing, we show that T function is essential for maintaining notochord cell fate and function. Progenitors adopt predominantly a neural fate in the absence of T, consistent with an origin from a common chordoneural progenitor. However, T function is dispensable for progenitor cell survival, proliferation, and EMT, which has implications for the therapeutic targeting of T in chordoma and other cancers.

Putative oncogene Brachyury (T) is essential to specify cell fate but dispensable for notochord progenitor proliferation and EMT

PubMed Central

Zhu, Jianjian; Kwan, Kin Ming; Mackem, Susan

2016-01-01

The transcription factor Brachyury (T) gene is expressed throughout primary mesoderm (primitive streak and notochord) during early embryonic development and has been strongly implicated in the genesis of chordoma, a sarcoma of notochord cell origin. Additionally, T expression has been found in and proposed to play a role in promoting epithelial–mesenchymal transition (EMT) in various other types of human tumors. However, the role of T in normal mammalian notochord development and function is still not well-understood. We have generated an inducible knockdown model to efficiently and selectively deplete T from notochord in mouse embryos. In combination with genetic lineage tracing, we show that T function is essential for maintaining notochord cell fate and function. Progenitors adopt predominantly a neural fate in the absence of T, consistent with an origin from a common chordoneural progenitor. However, T function is dispensable for progenitor cell survival, proliferation, and EMT, which has implications for the therapeutic targeting of T in chordoma and other cancers. PMID:27006501

A major defect in mast cell effector functions in CRACM1-/- mice

PubMed Central

Vig, Monika; Dehaven, Wayne I; Bird, Gary S; Billingsley, James M; Wang, Huiyun; Rao, Patricia E; Hutchings, Amy B; Jouvin, Marie-Hélène; Putney, James W; Kinet, Jean-Pierre

2008-01-01

CRACM1 (Orai1) constitutes the pore subunit of CRAC channels that are crucial for many physiological processes 1-6. A point mutation in CRACM1 has been associated with SCID disease in humans 2. We have generated CRACM1 deficient mice using gene trap, where β-galactosidase (LacZ) activity identifies CRACM1 expression in tissues. We show here that the homozygous CRACM1 deficient mice are considerably smaller in size and are grossly defective in mast cell degranulation and cytokine secretion. FcεRI-mediated in vivo allergic reactions were also inhibited in CRACM1-/- mice. Other tissues expressing truncated CRACM1-LacZ fusion protein include skeletal muscles, kidney and regions in the brain and heart. Surprisingly, no CRACM1 expression was seen in the lymphoid regions of thymus. Accordingly, we found no defect in T cell development. Thus, our data reveal novel crucial roles for CRAC channels including a putative role in excitable cells. PMID:18059270

Non-senescent Hydra tolerates severe disturbances in the nuclear lamina

PubMed Central

Rehm, Arvid; Wittlieb, Jörg; Herbst, Eva-Maria; Benavente, Ricardo

2018-01-01

The cnidarian Hydra is known for its unlimited lifespan and non-senescence, due to the indefinite self-renewal capacity of its stem cells. While proteins of the Lamin family are recognized as critical factors affecting senescence and longevity in human and mice, their putative role in the extreme longevity and non-senescence in long-living animals remains unknown. Here we analyze the role of a single lamin protein in non-senescence of Hydra. We demonstrate that proliferation of stem cells in Hydra is robust against the disturbance of Lamin expression and localization. While Lamin is indispensable for Hydra, the stem cells tolerate overexpression, downregulation and mislocalization of Lamin, and disturbances in the nuclear envelope structure. This extraordinary robustness may underlie the indefinite self-renewal capacity of stem cells and the non-senescence of Hydra. A relatively low complexity of the nuclear envelope architecture in basal Metazoa might allow for their extreme lifespans, while an increasing complexity of the nuclear architecture in bilaterians resulted in restricted lifespans. PMID:29754147

Physical structure and chromosomal localization of a gene encoding human p58[sup clk-1], a cell division control related protein kinase

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

Eipers, P.G.

1992-01-01

The gene for the human p58[sup clk[minus]1] protein kinase, a cell division control-related gene, has been mapped by somatic cell hybrid analyses, in situ localization with the chromosomal gene, and nested polymerase chain reaction amplification of microdissected chromosomes. These studies indicate that the expressed p58[sup clk[minus]1] chromosomal gene maps to 1p36, while a highly related p58[sup clk[minus]1] sequence of unknown nature maps to chromosome 15. Assignment of a p34[sup cdc2]-related gene to 1p36 region, including neuroblastoma, ductal carcinoma of the breast, malignant melanoma, Merkel cell carcinoma and endocrine neoplasia among others. Aberrant expression of this protein kinase negatively regulates normalmore » cellular growth. The p58[sup clk[minus]1] protein contains a central domain of 299 amino acids that is 46% identical to human p34[sup cdc2], the master mitotic protein kinase. This dissertation details the complete structure of the p58[sup clk[minus]1] chromosomal gene, including its putative promoter region, transcriptional start sites, exonic sequences, and intron/exon boundary sequences. The gene is 10 kb in size and contains 12 exons and 11 introns. Interestingly, the rather large 2.0 kb 3[prime] untranslated region is interrupted by an intron that separates a region containing numerous AUUUA destabilization motifs from the coding region. Furthermore, the expression of this gene in normal human tissues, as well as several human tumor cell samples and lines, is examined. The origin of multiple human transcripts from the same chromosomal gene, and the possible differential stability of these various transcripts, is discussed with regard to the transcriptional and post-transcriptional regulation of this gene. This is the first report of the chromosomal gene structure of a member of the p34[sup cdc2] supergene family.« less

Multiple Natural Substitutions in Avian Influenza A Virus PB2 Facilitate Efficient Replication in Human Cells.

PubMed

Mänz, Benjamin; de Graaf, Miranda; Mögling, Ramona; Richard, Mathilde; Bestebroer, Theo M; Rimmelzwaan, Guus F; Fouchier, Ron A M

2016-07-01

A strong restriction of the avian influenza A virus polymerase in mammalian cells generally limits viral host-range switching. Although substitutions like E627K in the PB2 polymerase subunit can facilitate polymerase activity to allow replication in mammals, many human H5N1 and H7N9 viruses lack this adaptive substitution. Here, several previously unknown, naturally occurring, adaptive substitutions in PB2 were identified by bioinformatics, and their enhancing activity was verified using in vitro assays. Adaptive substitutions enhanced polymerase activity and virus replication in mammalian cells for avian H5N1 and H7N9 viruses but not for a partially human-adapted H5N1 virus. Adaptive substitutions toward basic amino acids were frequent and were mostly clustered in a putative RNA exit channel in a polymerase crystal structure. Phylogenetic analysis demonstrated divergent dependency of influenza viruses on adaptive substitutions. The novel adaptive substitutions found in this study increase basic understanding of influenza virus host adaptation and will help in surveillance efforts. Influenza viruses from birds jump the species barrier into humans relatively frequently. Such influenza virus zoonoses may pose public health risks if the virus adapts to humans and becomes a pandemic threat. Relatively few amino acid substitutions-most notably in the receptor binding site of hemagglutinin and at positions 591 and 627 in the polymerase protein PB2-have been identified in pandemic influenza virus strains as determinants of host adaptation, to facilitate efficient virus replication and transmission in humans. Here, we show that substantial numbers of amino acid substitutions are functionally compensating for the lack of the above-mentioned mutations in PB2 and could facilitate influenza virus emergence in humans. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Evidence for presence of nonesterified fatty acids as potential gustatory signaling molecules in humans.

PubMed

Kulkarni, Bhushan; Mattes, Richard

2013-02-01

Gustatory fatty acid signaling termed "fatty acid taste" is initiated when nonesterified fatty acids (NEFA) bind to putative fat receptors on taste receptor cells. However, the source and quantity of NEFA in the oral cavity of humans are unresolved. Dietary fat is comprised predominantly of triacylglycerol, and human lingual lipase is of questionable functionality. The objective of this study was to characterize the species of NEFA in saliva and quantify their individual concentrations during oral processing of high-fat foods. Participants chewed fixed amounts of almonds, coconut, walnuts, almond butter, and olive oil (stimuli that vary in physical state and fatty acid composition) for 1 min at the rate of 1 bite/s and expectorated. The salivary NEFA from the expectorant were quantitatively and qualitatively analyzed by gas chromatography-mass spectrometry. Palmitic, oleic, linoleic, and stearic acids were the 4 predominant salivary NEFA, reflecting their concentrations in the foods tested. Their significantly increased concentrations ranged from 20 to 60 µM. Previous animal electrophysiological studies suggest that these NEFA concentrations are sufficient to depolarize taste receptor cells. These data indicate NEFA concentrations likely to be sufficient to initiate gustatory signaling are present in the human oral cavity when masticating high-fat foods.

A bioluminescent test system reveals valuable antioxidant properties of lactobacillus strains from human microbiota.

PubMed

Marsova, Maria; Abilev, Serikbay; Poluektova, Elena; Danilenko, Valeriy

2018-01-17

Oxidative stress cause serious damages in human organism resulting in multiple diseases. Antioxidant therapy includes diet, the use of chemical agents or commensal bacteria such as lactobacilli. This study aims to evaluate the antioxidant (AO) activity of cell-free culture supernatants of lactobacilli, isolated from different parts of the human body. A test system based on Escherichia coli MG1655 strains carrying plasmids encoding luminescent biosensors pSoxS-lux and pKatG-lux inducible by superoxide anion and hydrogen peroxide, respectively, was used to analyze cell-free culture supernatants of lactobacilli. Bioluminescent detection systems are suitable for quick screening of AO activity of lactobacilli. The majority of strains (51 out of 81) belonging to six different species demonstrated various levels of antioxidant activity. This activity was confirmed using the trolox equivalent method. The genome of one of the strains showing high AO activity was sequenced, and the genes putatively involved in AO capacity were determined. Potencies of standard AO and CFS from the most active Lactobacillus strains. Percentages of decrease in the detected luminescence (IAO%) in the presence of AO or CFS are presented. L. br.-L. brevis, L. pl. -L. plantarum, L. rh.-L. rhamnosus.

Human distribution and release of a putative new gut hormone, peptide YY.

PubMed

Adrian, T E; Ferri, G L; Bacarese-Hamilton, A J; Fuessl, H S; Polak, J M; Bloom, S R

1985-11-01

A radioimmunoassay has been developed for the new intestinal hormonal peptide tyrosine tyrosine [peptide YY (PYY)]. Peptide YY concentrations were measured in separated layers of the human gastrointestinal tract, where PYY was found exclusively in the mucosal epithelium which contained the endocrine cells. Peptide YY was found throughout the small intestine, in very low concentrations (5 pmol/g) in duodenum (6 pmol/g) and jejunum (5 pmol/g), but in higher concentrations in the terminal ileum (84 pmol/g). High concentrations were found throughout the colon (ascending 82 pmol/g, sigmoid 196 pmol/g), being maximum in the rectum (480 pmol/g). The major molecular form of PYY-like immunoreactivity in human intestine appeared to be identical to pure porcine hormone, both as judged by gel permeation chromatography and by reverse-phase high-pressure liquid chromatography. Basal plasma concentrations of PYY were low but rose in response to food, remaining elevated for several hours postprandially. The known potent biologic actions of PYY, its high concentrations in gut endocrine cells, and its release into the circulation after a normal meal suggest that this peptide may function physiologically as a circulating gut hormone.

The Gárdos channel: a review of the Ca2+-activated K+ channel in human erythrocytes.

PubMed

Maher, Anthony D; Kuchel, Philip W

2003-08-01

Ca(2+)-dependent K(+) efflux from human erythrocytes was first described in the 1950s. Subsequent studies revealed that a K(+)-specific membrane protein (the Gárdos channel) was responsible for this phenomenon (the Gárdos effect). In recent years several types of Ca-activated K(+) channel have been identified and studied in a wide range of cells, with the erythrocyte Gárdos channel serving as both a model for a broader physiological perspective, and an intriguing component of erythrocyte function. The existence of this channel has raised a number of questions. For example, what is its role in the establishment and maintenance of ionic distribution across the red cell membrane? What role might it play in erythrocyte development? To what extent is it active in circulating erythrocytes? What are the cell-physiological implications of its dysfunction?This review summarises current knowledge of this membrane protein with respect to its function and structure, its physiological roles (some putative) and its contribution to various disease states, and it provides an introduction to adaptable NMR methods, which is our own area of technical expertise, for such ion transport analysis.

Study on polymethylmethacrylate ring in protecting limbal stem cells during collagen cross-linking.

PubMed

Jeyalatha, Vimalin; Jambulingam, Malathi; Gupta, Nidhi; Padmanabhan, Prema; Madhavan, Hajib N

2013-01-01

The UV rays used in the collagen cross-linking (CXL) procedure seem to cause potential damage to the limbal stem cells. This study was designed to evaluate the ability of polymethylmethacrylate (PMMA) hemiannulus as an alternative to protect corneal limbal stem cells during CXL. Ten freshly enucleated human cadaveric eyeballs were subjected to the corneal CXL procedure. The cadaveric eye ball was divided into 2 sectors: A and B. Sector A was left unprotected, while sector B was covered by a PMMA shield. Limbal biopsies from both sectors before and after the procedure were analyzed. Each limbal tissue was placed on human amniotic membrane (HAM) to check the cultivability and was subjected to marker studies using reverse transcriptase PCR. Before CXL, biopsies from both sectors showed growth on HAM. After CXL, biopsies from sector A showed no growth on HAM while 2 out of the 10 from sector B covered with the PMMA ring did show growth on HAM. The putative stem-cell marker ABCG2 was negative in all the samples from sector A after CXL and was positive in 2 out of the 10 samples from sector B. Covering the limbal region with PMMA offers partial protection of the limbus from the UV rays during the CXL procedure. © 2013 S. Karger AG, Basel.

Phylloseptin-PBa—A Novel Broad-Spectrum Antimicrobial Peptide from the Skin Secretion of the Peruvian Purple-Sided Leaf Frog (Phyllomedusa Baltea) Which Exhibits Cancer Cell Cytotoxicity

PubMed Central

Wan, Yuantai; Ma, Chengbang; Zhou, Mei; Xi, Xinping; Li, Lei; Wu, Di; Wang, Lei; Lin, Chen; Lopez, Juan Chavez; Chen, Tianbao; Shaw, Chris

2015-01-01

Antimicrobial peptides from amphibian skin secretion display remarkable broad-spectrum antimicrobial activity and are thus promising for the discovery of new antibiotics. In this study, we report a novel peptide belonging to the phylloseptin family of antimicrobial peptides, from the skin secretion of the purple-sided leaf frog, Phyllomedusa baltea, which was named Phylloseptin-PBa. Degenerate primers complementary to putative signal peptide sites of frog skin peptide precursor-encoding cDNAs were designed to interrogate a skin secretion-derived cDNA library from this frog. Subsequently, the peptide was isolated and identified using reverse phase HPLC and MS/MS fragmentation. The synthetic replicate was demonstrated to have activity against S. aureus, E. coli and C. albicans at concentrations of 8, 128 and 8 mg/L, respectively. In addition, it exhibited anti-proliferative activity against the human cancer cell lines, H460, PC3 and U251MG, but was less active against a normal human cell line (HMEC). Furthermore, a haemolysis assay was performed to assess mammalian cell cytotoxicity of Phylloseptin-PBa. This peptide contained a large proportion of α-helical domain, which may explain its antimicrobial and anticancer activities. PMID:26633506

Male fertility preservation before gonadotoxic therapies

PubMed Central

Wyns, C.

2010-01-01

Background: Recent advances in cancer therapy have resulted in an increased number of long-term cancer survivors. Unfortunately, aggressive chemotherapy, radiotherapy and preparative regimens for bone marrow transplantation can severely affect male germ cells, including spermatogonial stem cells (SSCs), and lead to permanent loss of fertility. Different options for fertility preservation are dependent on the pubertal state of the patient. Methods: Relevant studies were identified by an extensive Medline search of English and French language articles. Results: Sperm cryopreservation prior to gonadotoxic treatment is a well established method after puberty. In case of ejaculation failure by masturbation, assisted ejaculation methods or testicular tissue sampling should be considered. Although no effective gonadoprotective drug is yet available for in vivo spermatogonial stem cell (SSC) protection in humans, current evidence supports the feasibility of immature testicular tissue (ITT) cryopreservation. The different cryopreservation protocols and available fertility restoration options from frozen tissue, i.e. cell suspension transplantation, tissue grafting and in vitro maturation, are presented. Results obtained in humans are discussed in the light of lessons learned from animal studies. Conclusion: Advances in reproductive technology have made fertility preservation a real possibility in young patients whose gonadal function is threatened by gonadotoxic therapies. The putative indications for such techniques, as well as their limitations according to disease, are outlined. PMID:25302103

Male fertility preservation before gonadotoxic therapies.

PubMed

Wyns, C

2010-01-01

Recent advances in cancer therapy have resulted in an increased number of long-term cancer survivors. Unfortunately, aggressive chemotherapy, radiotherapy and preparative regimens for bone marrow transplantation can severely affect male germ cells, including spermatogonial stem cells (SSCs), and lead to permanent loss of fertility. Different options for fertility preservation are dependent on the pubertal state of the patient. Relevant studies were identified by an extensive Medline search of English and French language articles. Sperm cryopreservation prior to gonadotoxic treatment is a well established method after puberty. In case of ejaculation failure by masturbation, assisted ejaculation methods or testicular tissue sampling should be considered. Although no effective gonadoprotective drug is yet available for in vivo spermatogonial stem cell (SSC) protection in humans, current evidence supports the feasibility of immature testicular tissue (ITT) cryopreservation. The different cryopreservation protocols and available fertility restoration options from frozen tissue, i.e. cell suspension transplantation, tissue grafting and in vitro maturation, are presented. RESULTS obtained in humans are discussed in the light of lessons learned from animal studies. Advances in reproductive technology have made fertility preservation a real possibility in young patients whose gonadal function is threatened by gonadotoxic therapies. The putative indications for such techniques, as well as their limitations according to disease, are outlined.

Utility of the dual-specificity protein kinase TTK as a therapeutic target for intrahepatic spread of liver cancer.

PubMed

Miao, Ruoyu; Wu, Yan; Zhang, Haohai; Zhou, Huandi; Sun, Xiaofeng; Csizmadia, Eva; He, Lian; Zhao, Yi; Jiang, Chengyu; Miksad, Rebecca A; Ghaziani, Tahereh; Robson, Simon C; Zhao, Haitao

2016-09-13

Therapies for primary liver cancer, the third leading cause of cancer-related death worldwide, remain limited. Following multi-omics analysis (including whole genome and transcriptome sequencing), we were able to identify the dual-specific protein kinase TTK as a putative new prognostic biomarker for liver cancer. Herein, we show that levels of TTK protein are significantly elevated in neoplastic tissues from a cohort of liver cancer patients, when compared with adjacent hepatic tissues. We also tested the utility of TTK targeted inhibition and have demonstrated therapeutic potential in an experimental model of liver cancer in vivo. Following lentiviral shRNA knockdown in several human liver cancer cell lines, we demonstrated that TTK boosts cell growth and promotes cell spreading; as well as protects against senescence and decreases autophagy. In an experimental animal model, we show that in vitro knockdown of TTK effectively blocks intrahepatic growth of human HCC xenografts. Furthermore, we note that, in vivo silencing of TTK, by systemically delivering TTK siRNAs to already tumor-bearing liver, limits intrahepatic spread of liver cancer cells. This intervention is associated with decreased tumor aggressiveness, as well as increased senescence and autophagy. Taken together, our data suggest that targeted TTK inhibition might have clinical utility as an adjunct therapy in management of liver cancer.

Phylloseptin-PBa--A Novel Broad-Spectrum Antimicrobial Peptide from the Skin Secretion of the Peruvian Purple-Sided Leaf Frog (Phyllomedusa Baltea) Which Exhibits Cancer Cell Cytotoxicity.

PubMed

Wan, Yuantai; Ma, Chengbang; Zhou, Mei; Xi, Xinping; Li, Lei; Wu, Di; Wang, Lei; Lin, Chen; Lopez, Juan Chavez; Chen, Tianbao; Shaw, Chris

2015-12-01

Antimicrobial peptides from amphibian skin secretion display remarkable broad-spectrum antimicrobial activity and are thus promising for the discovery of new antibiotics. In this study, we report a novel peptide belonging to the phylloseptin family of antimicrobial peptides, from the skin secretion of the purple-sided leaf frog, Phyllomedusa baltea, which was named Phylloseptin-PBa. Degenerate primers complementary to putative signal peptide sites of frog skin peptide precursor-encoding cDNAs were designed to interrogate a skin secretion-derived cDNA library from this frog. Subsequently, the peptide was isolated and identified using reverse phase HPLC and MS/MS fragmentation. The synthetic replicate was demonstrated to have activity against S. aureus, E. coli and C. albicans at concentrations of 8, 128 and 8 mg/L, respectively. In addition, it exhibited anti-proliferative activity against the human cancer cell lines, H460, PC3 and U251MG, but was less active against a normal human cell line (HMEC). Furthermore, a haemolysis assay was performed to assess mammalian cell cytotoxicity of Phylloseptin-PBa. This peptide contained a large proportion of α-helical domain, which may explain its antimicrobial and anticancer activities.

P53 oncosuppressor influences selection of genomic imbalances in response to ionizing radiations in human osteosarcoma cell line SAOS-2.

PubMed

Zuffa, Elisa; Mancini, Manuela; Brusa, Gianluca; Pagnotta, Eleonora; Hattinger, Claudia Maria; Serra, Massimo; Remondini, Daniel; Castellani, Gastone; Corrado, Patrizia; Barbieri, Enza; Santucci, Maria Alessandra

2008-07-01

To investigate the impact of TP53 (tumor protein 53, p53) on genomic stability of osteosarcoma (OS). In first instance, we expressed in OS cell line SAOS-2 (lacking p53) a wild type (wt) p53 construct, whose protein undergoes nuclear import and activation in response to ionizing radiations (IR). Thereafter, we investigated genomic imbalances (amplifications and deletions at genes or DNA regions most frequently altered in human cancers) associated with radio-resistance relative to p53 expression by mean of an array-based comparative genomic hybridization (aCGH) strategy. Finally we investigated a putative marker of radio-induced oxidative stress, a 4,977 bp deletion at mitochondrial (mt) DNA usually referred to as 'common' deletion, by mean of a polimerase chain reaction (PCR) strategy. In radio-resistant subclones generated from wt p53-transfected SAOS-2 cells DNA deletions were remarkably reduced and the accumulation of 'common' deletion at mtDNA (that may let the persistence of oxidative damage by precluding detoxification from reactive oxygen species [ROS]) completely abrogated. The results of our study confirm that wt p53 has a role in protection of OS cell DNA integrity. Multiple mechanisms involved in p53 safeguard of genomic integrity and prevention of deletion outcome are discussed.

TNF induction of jagged-1 in endothelial cells is NFκB-dependent

PubMed Central

Johnston, Douglas A.; Dong, Bamboo; Hughes, Christopher C.W.

2009-01-01

TNF-α is a potent proinflammatory cytokine that induces endothelial cell (EC) adhesion molecules. In addition, TNF promotes angiogenesis by inducing an EC tip cell phenotype and the expression of jagged-1, a ligand for the notch pathway. Notch signaling is critical for vascular patterning and helps to restrict the proliferation of tip cells. Here we demonstrate that TNF induction of jagged-1 in human EC is rapid and dependent upon signaling through TNFR1, but not TNFR2. A luciferase reporter construct carrying 3.7 kb of 5′ promoter sequence from the human gene was responsive to both TNF and overexpression of NFκB pathway components. TNF-induced promoter activation was blocked by treatment with an NFκB inhibitor or co-expression of dominant-negative IKKβ. Mutations in a putative NFκB-binding site at −3.0 kb, which is conserved across multiple species, resulted in a loss of responsiveness to TNF and NFκB. Electromobility shift and chromatin immunoprecipitation assays revealed binding of both p50 and p65 to the promoter in response to TNF treatment. Full promoter activity also depends on an AP-1 site at −2.0 kb. These results indicate that canonical NFκB signaling is required for TNF induction of the notch ligand jagged-1 in EC. PMID:19393188

Healthy human T-Cell Responses to Aspergillus fumigatus antigens.

PubMed

Chaudhary, Neelkamal; Staab, Janet F; Marr, Kieren A

2010-02-17

Aspergillus fumigatus is associated with both invasive and allergic pulmonary diseases, in different hosts. The organism is inhaled as a spore, which, if not cleared from the airway, germinates into hyphal morphotypes that are responsible for tissue invasion and resultant inflammation. Hyphae secrete multiple products that function as antigens, evoking both a protective (T(H)1-T(H)17) and destructive allergic (T(H)2) immunity. How Aspergillus allergens (Asp f proteins) participate in the development of allergic sensitization is unknown. To determine whether Asp f proteins are strictly associated with T(H)2 responses, or represent soluble hyphal products recognized by healthy hosts, human T cell responses to crude and recombinant products were characterized by ELISPOT. While responses (number of spots producing IFN-gamma, IL-4 or IL-17) to crude hyphal antigen preparations were weak, responses to recombinant Asp f proteins were higher. Recombinant allergens stimulated cells to produce IFN-gamma more so than IL-4 or IL-17. Volunteers exhibited a diverse CD4+ and CD8+ T cell antigen recognition profile, with prominent CD4 T(H)1-responses to Asp f3 (a putative peroxismal membrane protein), Asp f9/16 (cell wall glucanase), Asp f11 (cyclophilin type peptidyl-prolyl isomerase) and Asp f22 (enolase). Strong IFN-gamma responses were reproduced in most subjects tested over 6 month intervals. Products secreted after conidial germination into hyphae are differentially recognized by protective T cells in healthy, non-atopic individuals. Defining the specificity of the human T cell repertoire, and identifying factors that govern early responses may allow for development of novel diagnostics and therapeutics for both invasive and allergic Aspergillus diseases.

Immunohistochemical estimation of cell cycle phase in laryngeal neoplasia

PubMed Central

Chatrath, P; Scott, I S; Morris, L S; Davies, R J; Bird, K; Vowler, S L; Coleman, N

2006-01-01

We previously developed an immunohistochemical method for estimating cell cycle state and phase in tissue samples, including biopsies that are too small for flow cytometry. We have used our technique to examine whether primary abnormalities of the cell cycle exist in laryngeal neoplasia. Antibodies against the markers of cell cycle entry, minichromosome maintenance protein-2 (Mcm-2) and Ki67, and putative markers of cell cycle phase, cyclin D1 (G1-phase), cyclin A (S-phase), cyclin B1 (G2-phase) and phosphohistone H3 (Mitosis) were applied to paraffin-embedded sections of normal larynx (n=8), laryngeal dysplasia (n=10) and laryngeal squamous cell carcinoma (n=10). Cells expressing each marker were determined as a percentage of total cells, termed the labelling index (LI), and as a percentage of Mcm-2-positive cells, termed the labelling fraction (LF). The frequency of coexpression of each putative phase marker was investigated by confocal microscopy. There was a correlation between Mcm-2 and Ki67 LIs (ρ=0.93) but Mcm-2 LIs were consistently higher. All cells expressing a phase marker coexpressed Mcm-2, whereas Ki67 was not expressed in a proportion of these cells. The putative phase markers showed little coexpression. Labelling index values increased on progression from normal larynx through laryngeal dysplasia to squamous cell carcinoma for Mcm-2 (P=0.001), Ki67 (P=0.0002), cyclin D1 (P=0.015), cyclin A (P=0.0001) and cyclin B1 (P=0.0004). There was no evidence of an increase in the LF for any phase marker. Immunohistochemistry can be used to estimate cell cycle state and phase in laryngeal biopsies. Our data argues against primary cell cycle phase abnormalities in laryngeal neoplasia. PMID:16832409

Absence of specific binding of several putative neuro-transmitters to human fibroblasts.

PubMed

Berrettini, W H; Nadi, N S; Gershon, E S

1983-01-01

Fibroblasts were examined for specific binding sites of ten putative neurotransmitters to determine whether this tissue could be used in receptor studies of neurologic and psychiatric disorders. Stereospecific saturable binding was not found for any of the ligands: arginine vasopressin, neurotensin, somatostatin, angiotensin II, thyrotropin-releasing hormone (TRH), alpha-bungarotoxin, LSD, dihydromorphine, muscimol and spiperone.

Merkel cell polyomavirus small T antigen initiates Merkel cell carcinoma-like tumor development in mice

PubMed Central

Verhaegen, Monique E.; Mangelberger, Doris; Harms, Paul W.; Eberl, Markus; Wilbert, Dawn M.; Meireles, Julia; Bichakjian, Christopher K.; Saunders, Thomas L.; Wong, Sunny Y.; Dlugosz, Andrzej A.

2017-01-01

Merkel cell carcinoma (MCC) tumor cells express several markers detected in normal Merkel cells, a non-proliferative population of neuroendocrine cells which arise from epidermis. MCCs frequently contain Merkel cell polyomavirus (MCPyV) DNA and express viral transforming antigens, sT and tLT, but the role of these putative oncogenes in MCC development, and this tumor’s cell of origin, are unknown. Using a panel of pre-term transgenic mice, we show that epidermis-targeted co-expression of sT and the cell fate determinant atonal bHLH transcription factor 1 (Atoh1) leads to development of widespread cellular aggregates with histology and marker expression mimicking that of human intraepidermal MCC. The MCC-like tumor phenotype was dependent on the FBXW7-binding domain of sT, but not the sT-PP2A binding domain. Co-expression of MCPyV tLT did not appreciably alter the phenotype driven by either sT or sT combined with Atoh1. MCPyV sT, when co-expressed with Atoh1, is thus sufficient to initiate development of epidermis-derived MCC-like tumors in mice. PMID:28512245

Merkel Cell Polyomavirus Small T Antigen Initiates Merkel Cell Carcinoma-like Tumor Development in Mice.

PubMed

Verhaegen, Monique E; Mangelberger, Doris; Harms, Paul W; Eberl, Markus; Wilbert, Dawn M; Meireles, Julia; Bichakjian, Christopher K; Saunders, Thomas L; Wong, Sunny Y; Dlugosz, Andrzej A

2017-06-15

Merkel cell carcinoma (MCC) tumor cells express several markers detected in normal Merkel cells, a nonproliferative population of neuroendocrine cells that arise from epidermis. MCCs frequently contain Merkel cell polyomavirus (MCPyV) DNA and express viral transforming antigens, sT and tLT, but the role of these putative oncogenes in MCC development, and this tumor's cell of origin, are unknown. Using a panel of preterm transgenic mice, we show that epidermis-targeted coexpression of sT and the cell fate-determinant atonal bHLH transcription factor 1 (ATOH1) leads to development of widespread cellular aggregates, with histology and marker expression mimicking that of human intraepidermal MCC. The MCC-like tumor phenotype was dependent on the FBXW7-binding domain of sT, but not the sT-PP2A binding domain. Coexpression of MCPyV tLT did not appreciably alter the phenotype driven by either sT or sT combined with ATOH1. MCPyV sT, when coexpressed with ATOH1, is thus sufficient to initiate development of epidermis-derived MCC-like tumors in mice. Cancer Res; 77(12); 3151-7. ©2017 AACR . ©2017 American Association for Cancer Research.

Roles of the Putative Type IV-like Secretion System Key Component VirD4 and PrsA in Pathogenesis of Streptococcus suis Type 2

PubMed Central

Jiang, Xiaowu; Yang, Yunkai; Zhou, Jingjing; Zhu, Lexin; Gu, Yuanxing; Zhang, Xiaoyan; Li, Xiaoliang; Fang, Weihuan

2016-01-01

Streptococcus suis type 2 (SS2) is a zoonotic pathogen causing septic infection, meningitis and pneumonia in pigs and humans. SS2 may cause streptococcal toxic shock syndrome (STSS) probably due to excessive release of inflammatory cytokines. A previous study indicated that the virD4 gene in the putative type IV-like secretion system (T4SS) within the 89K pathogenicity island specific for recent epidemic strains contributed to the development of STSS. However, the functional basis of VirD4 in STSS remains unclear. Here we show that deletion of virD4 led to reduced virulence as shown by about 65% higher LD50, lower bacterial load in liver and brain, and lower level of expression of inflammatory cytokines in mice and cell lines than its parent strain. The ΔVirD4 mutant was more easily phagocytosed, suggesting its role as an anti-phagocytic factor. Oxidative stress that mimic bacterial exposure to respiratory burst of phagocytes upregulated expression of virD4. Proteomic analysis identified 10 secreted proteins of significant differences between the parent and mutant strains under oxidative stress, including PrsA, a peptidyl-prolyl isomerase. The SS2 PrsA expressed in E. coli caused a dose-dependent cell death and increased expression of proinflammatory IL-1β, IL-6 and TNF-α in murine macrophage cells. Our data provide novel insights into the contribution of the VirD4 factor to STSS pathogenesis, possibly via its anti-phagocytic activity, upregulation of its expression upon oxidative stress and its involvement in increased secretion of PrsA as a cell death inducer and proinflammatory effector. PMID:27995095

The candidate tumor suppressor gene, RASSF1A, from human chromosome 3p21.3 is involved in kidney tumorigenesis

PubMed Central

Dreijerink, Koen; Braga, Eleonora; Kuzmin, Igor; Geil, Laura; Duh, Fuh-Mei; Angeloni, Debora; Zbar, Berton; Lerman, Michael I.; Stanbridge, Eric J.; Minna, John D.; Protopopov, Alexei; Li, Jingfeng; Kashuba, Vladimir; Klein, George; Zabarovsky, Eugene R.

2001-01-01

Clear cell-type renal cell carcinomas (clear RCC) are characterized almost universally by loss of heterozygosity on chromosome 3p, which usually involves any combination of three regions: 3p25-p26 (harboring the VHL gene), 3p12-p14.2 (containing the FHIT gene), and 3p21-p22, implying inactivation of the resident tumor-suppressor genes (TSGs). For the 3p21-p22 region, the affected TSGs remain, at present, unknown. Recently, the RAS association family 1 gene (isoform RASSF1A), located at 3p21.3, has been identified as a candidate lung and breast TSG. In this report, we demonstrate aberrant silencing by hypermethylation of RASSF1A in both VHL-caused clear RCC tumors and clear RCC without VHL inactivation. We found hypermethylation of RASSF1A's GC-rich putative promoter region in most of analyzed samples, including 39 of 43 primary tumors (91%). The promoter was methylated partially or completely in all 18 RCC cell lines analyzed. Methylation of the GC-rich putative RASSF1A promoter region and loss of transcription of the corresponding mRNA were related causally. RASSF1A expression was reactivated after treatment with 5-aza-2′-deoxycytidine. Forced expression of RASSF1A transcripts in KRC/Y, a renal carcinoma cell line containing a normal and expressed VHL gene, suppressed growth on plastic dishes and anchorage-independent colony formation in soft agar. Mutant RASSF1A had reduced growth suppression activity significantly. These data suggest that RASSF1A is the candidate renal TSG gene for the 3p21.3 region. PMID:11390984

Overexpression of syndecan-1, MUC-1, and putative stem cell markers in breast cancer leptomeningeal metastasis: a cerebrospinal fluid flow cytometry study.

PubMed

Cordone, Iole; Masi, Serena; Summa, Valentina; Carosi, Mariantonia; Vidiri, Antonello; Fabi, Alessandra; Pasquale, Alessia; Conti, Laura; Rosito, Immacolata; Carapella, Carmine Maria; Villani, Veronica; Pace, Andrea

2017-04-11

Cancer is a mosaic of tumor cell subpopulations, where only a minority is responsible for disease recurrence and cancer invasiveness. We focused on one of the most aggressive circulating tumor cells (CTCs) which, from the primitive tumor, spreads to the central nervous system (CNS), evaluating the expression of prognostic and putative cancer stem cell markers in breast cancer (BC) leptomeningeal metastasis (LM). Flow cytometry immunophenotypic analysis of cerebrospinal fluid (CSF) samples (4.5 ml) was performed in 13 consecutive cases of BCLM. Syndecan-1 (CD138), MUC-1 (CD227) CD45, CD34, and the putative cancer stem cell markers CD15, CD24, CD44, and CD133 surface expression were evaluated on CSF floating tumor cells. The tumor-associated leukocyte population was also characterized. Despite a low absolute cell number (8 cell/μl, range 1-86), the flow cytometry characterization was successfully conducted in all the samples. Syndecan-1 and MUC-1 overexpression was documented on BC cells in all the samples analyzed; CD44, CD24, CD15, and CD133 in 77%, 75%, 70%, and 45% of cases, respectively. A strong syndecan-1 and MUC-1 expression was also documented by immunohistochemistry on primary breast cancer tissues, performed in four patients. The CSF tumor population was flanked by T lymphocytes, with a different immunophenotype between the CSF and peripheral blood samples (P ≤ 0.02). Flow cytometry can be successfully employed for solid tumor LM characterization even in CSF samples with low cell count. This in vivo study documents that CSF floating BC cells overexpress prognostic and putative cancer stem cell biomarkers related to tumor invasiveness, potentially representing a molecular target for circulating tumor cell detection and LM treatment monitoring, as well as a primary target for innovative treatment strategies. The T lymphocyte infiltration, documented in all CSF samples, suggests a possible involvement of the CNS lymphatic system in both lymphoid and cancer cell migration into and out of the meninges, supporting the extension of a new form of cellular immunotherapy to LM. Due to the small number of cases, validation on large cohorts of patients are warranted to confirm these findings and to evaluate the impact and value of these results for diagnosis and management of LM.

PHTS, a novel putative tumor suppressor, is involved in the transformation reversion of HeLaHF cells independently of the p53 pathway

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

Yu Dehua; Fan, Wufang; Liu, Guohong

2006-04-01

HeLaHF is a non-transformed revertant of HeLa cells, likely resulting from the activation of a putative tumor suppressor(s). p53 protein was stabilized in this revertant and reactivated for certain transactivation functions. Although p53 stabilization has not conclusively been linked to the reversion, it is clear that the genes in p53 pathway are involved. The present study confirms the direct role of p53 in HeLaHF reversion by demonstrating that RNAi-mediated p53 silencing partially restores anchorage-independent growth potential of the revertant through the suppression of anoikis. In addition, we identified a novel gene, named PHTS, with putative tumor suppressor properties, and showedmore » that this gene is also involved in HeLaHF reversion independently of the p53 pathway. Expression profiling revealed that PHTS is one of the genes that is up-regulated in HeLaHF but not in HeLa. It encodes a putative protein with CD59-like domains. RNAi-mediated PHTS silencing resulted in the partial restoration of transformation (anchorage-independent growth) in HeLaHF cells, similar to that of p53 gene silencing, implying its tumor suppressor effect. However, the observed increased transformation potential by PHTS silencing appears to be due to an increased anchorage-independent proliferation rate rather than suppression of anoikis, unlike the effect of p53 silencing. p53 silencing did not affect PHTS gene expression, and vice versa, suggesting PHTS may function in a new and p53-independent tumor suppressor pathway. Furthermore, over-expression of PHTS in different cancer cell lines, in addition to HeLa, reduces cell growth likely via induced apoptosis, confirming the broad PHTS tumor suppressor properties.« less

kappa-Opioid receptor in humans: cDNA and genomic cloning, chromosomal assignment, functional expression, pharmacology, and expression pattern in the central nervous system.

PubMed Central

Simonin, F; Gavériaux-Ruff, C; Befort, K; Matthes, H; Lannes, B; Micheletti, G; Mattéi, M G; Charron, G; Bloch, B; Kieffer, B

1995-01-01

Using the mouse delta-opioid receptor cDNA as a probe, we have isolated genomic clones encoding the human mu- and kappa-opioid receptor genes. Their organization appears similar to that of the human delta receptor gene, with exon-intron boundaries located after putative transmembrane domains 1 and 4. The kappa gene was mapped at position q11-12 in human chromosome 8. A full-length cDNA encoding the human kappa-opioid receptor has been isolated. The cloned receptor expressed in COS cells presents a typical kappa 1 pharmacological profile and is negatively coupled to adenylate cyclase. The expression of kappa-opioid receptor mRNA in human brain, as estimated by reverse transcription-polymerase chain reaction, is consistent with the involvement of kappa-opioid receptors in pain perception, neuroendocrine physiology, affective behavior, and cognition. In situ hybridization studies performed on human fetal spinal cord demonstrate the presence of the transcript specifically in lamina II of the dorsal horn. Some divergences in structural, pharmacological, and anatomical properties are noted between the cloned human and rodent receptors. Images Fig. 3 Fig. 4 PMID:7624359

Exosomal particles secreted by prostate cancer cells are potent mRNA and protein vehicles for the interference of tumor and tumor environment.

PubMed

Rauschenberger, Lisa; Staar, Doreen; Thom, Kathleen; Scharf, Christian; Venz, Simone; Homuth, Georg; Schlüter, Rabea; Brandenburg, Lars-Ove; Ziegler, Patrick; Zimmermann, Uwe; Weitschies, Werner; Völker, Uwe; Lendeckel, Uwe; Walther, Reinhard; Burchardt, Martin; Stope, Matthias B

2016-03-01

Remodeling of the tumor environment and the modulation of tumor associated non-malignant cells are essential events in tumor progression. Exosomes are small membranous vesicles of 50-150 nm in diameter, which are secreted into the extracellular space and supposedly serve as vehicles for signal and effector molecules to modulate adjacent target cells. We characterized the mRNA and protein composition as well as cellular functions of prostate cancer cell-derived exosomes. Exosomes were prepared from prostate cancer cell culture supernatant by ultracentrifugation and subsequently characterized by dynamic light scattering and electron microscopy. Exosomal mRNA and protein composition were analyzed by DNA microarrays and gel electrophoresis coupled with mass spectrometry. Physiological effects of exosomes were studied by means of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and lactate dehydrogenase release cell assays. Using a SILAC approach, putative uptake of exosomal human proteins in canine cells and canine de novo synthesis of proteins specified by exosome-transferred human mRNA was analyzed in MDCK cells via mass spectrometry. Preparations of exosomes revealed typical cup shaped particles of 150 nm in diameter. Analysis of mRNA and protein composition of exosomes exhibited a wide range of mRNA and protein species. Interestingly, the packaging of at least small proteins into exosomes was apparently unspecific, as shown with the example of two model proteins. In cell culture incubation experiments exosomal preparations of prostate cancer cells caused anti-proliferative effects. MS analysis revealed the uptake of exosomal human proteins into canine cells after 6 hr of incubation. The results reveal a distinct exosomal functionality in the modulation of the prostatic tumor adjacent environment. The multitude of translocated factors implies the induction of numerous effects in tumor-associated target cells, including impact on cellular growth. © 2015 Wiley Periodicals, Inc.

In Silico Prediction and Validation of Novel RNA Binding Proteins and Residues in the Human Proteome.

PubMed

Chowdhury, Shomeek; Zhang, Jian; Kurgan, Lukasz

2018-05-28

Deciphering a complete landscape of protein-RNA interactions in the human proteome remains an elusive challenge. We computationally elucidate RNA binding proteins (RBPs) using an approach that complements previous efforts. We employ two modern complementary sequence-based methods that provide accurate predictions from the structured and the intrinsically disordered sequences, even in the absence of sequence similarity to the known RBPs. We generate and analyze putative RNA binding residues on the whole proteome scale. Using a conservative setting that ensures low, 5% false positive rate, we identify 1511 putative RBPs that include 281 known RBPs and 166 RBPs that were previously predicted. We empirically demonstrate that these overlaps are statistically significant. We also validate the putative RBPs based on two major hallmarks of their RNA binding residues: high levels of evolutionary conservation and enrichment in charged amino acids. Moreover, we show that the novel RBPs are significantly under-annotated functionally which coincides with the fact that they were not yet found to interact with RNAs. We provide two examples of our novel putative RBPs for which there is recent evidence of their interactions with RNAs. The dataset of novel putative RBPs and RNA binding residues for the future hypothesis generation is provided in the Supporting Information. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A combination of valproic acid sodium salt, CHIR99021, E-616452, tranylcypromine, and 3-Deazaneplanocin A causes stem cell-like characteristics in cancer cells.

PubMed

Sha, Shuang; Zhai, Yuanfen; Lin, Chengzhao; Wang, Heyong; Chang, Qing; Song, Shuang; Ren, Mingqiang; Liu, Gentao

2017-08-08

Many studies are based on the hypothesis that recurrence and drug resistance in lung carcinoma are due to a subpopulation of cancer stem-like cells (CSLCs) in solid tumors. Therefore it is crucial to screen for and recognize lung CSLCs. In this study, we stimulated non-small cell lung cancer (NSCLC) A549 cells to display stem cell-like characteristics using a combination of five small molecule compounds. The putative A549 stem cells activated an important CSLC marker, CD133 protein, as well multiple CSLC-related genes including ATP-binding cassette transporter G2 (ABCG2), C-X-C chemokine receptor type 4 (CXCR4), NESTIN, and BMI1. The A549 stem-like cells displayed resistance to the chemotherapeutic drugs etoposide and cisplatin, epithelial-to-mesenchymal transition properties, and increased protein expression levels of NOTCH1 and Hes Family bHLH Transcription Factor 1 (HES1). When A549 cells were pretreated with a NOTCH signaling pathway inhibitor before compound induction, expression of the NOTCH1 target gene HES1 was reduced. This demonstrated that the NOTCH signaling pathway in the putative A549 stem-like cells had been activated. Together, the results of our study showed that a combination of five small molecule agents could transform A549 cells into putative stem-like cells, and that these compounds could also elevate CD133 and ABCG2 protein expression levels in H460 cells. This study provides a convenient method for obtaining lung CSLCs, which may be an effective strategy for developing lung carcinoma treatments.

Organotypic three-dimensional culture model of mesenchymal ...

EPA Pesticide Factsheets

Tissue fusion during early mammalian development requires coordination of multiple cell types, the extracellular matrix, and complex signaling pathways. Fusion events during processes including heart development, neural tube closure, and palatal fusion are dependent on signaling pathways elucidated using gene knockout mouse models. A broad analysis of literature, ToxRefDB, and ToxCast identified 63 chemicals that are related to cleft palate. However,the influence of these putative teratogens on human palatal fusion has not been studied due to the lack of in vitro models. We sought to engineer the stratified mesenchymal and epithelial structure of the developing palate in vitro via organotypic culture of human mesenchymal stem cell (hMSC) spheroids coated with a single layer of human primary epidermalkeratinocytes (hPEKp). hMSC spheroids exhibited uniform size over time (175 ± 21 µm mean diameter) proportional to starting cell density. Further, we developed a novel procedure to coat hMSC spheroids homogeneously with a single layer of hPEKp cells using a seeding ratio of 0.1-0.2 hPEKp per hMSC, and hMSC/hPEKp spheroids expressed mesenchymal markers (vim+, C044+, CD105+, CD34-) and epithelial markers (krt17+, itga6+) via qRT-PCR. Analysis of adverse outcome pathways related to palate fusion points to an EGF/TGFj33 switch that could be a target for cleft palate teratogens, and both egf and egfr were expressed by hMSC/hPEKp spheres. Finally, hMSCs and hPE

Expression of the serine/threonine kinase hSGK1 in chronic viral hepatitis.

PubMed

Fillon, Sophie; Klingel, Karin; Wärntges, Simone; Sauter, Martina; Gabrysch, Sabine; Pestel, Sabine; Tanneur, Valerie; Waldegger, Siegfried; Zipfel, Annette; Viebahn, Richard; Häussinger, Dieter; Bröer, Stefan; Kandolf, Reinhard; Lang, Florian

2002-01-01

The human serine/threonine kinase hSGK1 is expressed ubiquitously with highest transcript levels in pancreas and liver. This study has been performed to determine the hSGK1 distribution in normal liver and its putative role in fibrosing liver disease. HSGK1-localization was determined by in situ hybridization, regulation of hSGK1-transcription by Northern blotting, fibronectin synthesis and hSGK1 phosphorylation by Western blotting. In normal liver hSGK1 was mainly transcribed by Kupffer cells. In liver tissue from patients with chronic viral hepatitis, hSGK1 transcript levels were excessively high in numerous activated Kupffer cells and inflammatory cells localized within fibrous septum formations. HSGK1 transcripts were also detected in activated hepatic stellate cells. Accordingly, Western blotting revealed that tissue from fibrotic liver expresses excessive hSGK1 protein as compared to normal liver. TGF-beta1 (2 ng/ml) increases hSGK1 transcription in both human U937 macro-phages and HepG2 hepatoma cells. H(2)O(2) (0.3 mM) activated hSGK1 and increased fibronectin formation in HepG2 cells overexpressing hSGK1 but not in HepG2 cells expressing the inactive mutant hSGK1(K127R). In conclusion hSGK1 is upregulated by TGF-beta1 during hepatitis and may contribute to enhanced matrix formation during fibrosing liver disease. Copyright 2002 S. Karger AG, Basel

Neo-vascularization of the stroke cavity by implantation of human neural stem cells on VEGF-releasing PLGA microparticles

PubMed Central

Bible, Ellen; Qutachi, Omar; Chau, David Y.S.; Alexander, Morgan R.; Shakesheff, Kevin M.; Modo, Michel

2012-01-01

Replacing the tissue lost after a stroke potentially provides a new neural substrate to promote recovery. However, significant neurobiological and biotechnological challenges need to be overcome to make this possibility into a reality. Human neural stem cells (hNSCs) can differentiate into mature brain cells, but require a structural support that retains them within the cavity and affords the formation of a de novo tissue. Nevertheless, in our previous work, even after a week, this primitive tissue is void of a vasculature that could sustain its long-term viability. Therefore, tissue engineering strategies are required to develop a vasculature. Vascular endothelial growth factor (VEGF) is known to promote the proliferation and migration of endothelial cells during angio- and arteriogenesis. VEGF by itself here did not affect viability or differentiation of hNSCs, whereas growing cells on poly(D,L-lactic acid-co-glycolic acid) (PLGA) microparticles, with or without VEGF, doubled astrocytic and neuronal differentiation. Secretion of a burst and a sustained delivery of VEGF from the microparticles in vivo attracted endothelial cells from the host into this primate tissue and in parts established a neovasculature, whereas in other parts endothelial cells were merely interspersed with hNSCs. There was also evidence of a hypervascularization indicating that further work will be required to establish an adequate level of vascularization. It is therefore possible to develop a putative neovasculature within de novo tissue that is forming inside a tissue cavity caused by a stroke. PMID:22818980

The AICD interacting protein DAB1 is up-regulated in Alzheimer frontal cortex brain samples and causes deregulation of proteins involved in gene expression changes.

PubMed

Müller, T; Loosse, C; Schrötter, A; Schnabel, A; Helling, S; Egensperger, R; Marcus, K

2011-08-01

AICD is the intracellular subdomain of the amyloid precursor protein thought to play a pivotal role as a potential transcription factor that might be of relevance for the pathophysiology of Alzheimer's disease. For its signal transduction potential AICD requires interacting proteins like FE65 and TIP60. However, many other proteins were described being able to bind to AICD. Here, we studied mRNA levels of AICD interacting proteins and found one of them (DAB1) strongly up-regulated in human post-mortem frontal cortex brain samples of AD patients. Subsequent cell culture experiments revealed that elevated DAB1 level results in the deregulation of the cellular proteome. We found the proliferation associated protein 2G4 as well as the guanine monophosphate synthetase (GMPS) significantly up-regulated in DAB1 over-expressing cells. Both proteins can be involved in cellular transcription processes supporting the hypothesis that DAB1 acts via modification of the AICD-dependent transcriptionally active complex. Of note, expression of the three components of the putative transcription complex (AICD, FE65, and TIP60 (AFT)) also revealed deregulation of the GMPS protein in an opposite fashion. Our results point to a putative relevance of AICD-dependent mechanisms in AD, caused by protein abundance changes of AICD interacting proteins, as shown for DAB1 in this work.

Data from Tiered High-Throughput Screening Approach to Identify Thyroperoxidase Inhibitors within the ToxCast Phase I and II Chemical Libraries

EPA Pesticide Factsheets

High-throughput screening for potential thyroid-disrupting chemicals requires a system of assays to capture multiple molecular-initiating events (MIEs) that converge on perturbed thyroid hormone (TH) homeostasis. Screening for MIEs specific to TH-disrupting pathways is limited in the U.S. Environmental Protection Agency ToxCast screening assay portfolio. To fill 1 critical screening gap, the Amplex UltraRed-thyroperoxidase (AUR-TPO) assay was developed to identify chemicals that inhibit TPO, as decreased TPO activity reduces TH synthesis. The ToxCast phase I and II chemical libraries, comprised of 1074 unique chemicals, were initially screened using a single, high concentration to identify potential TPO inhibitors. Chemicals positive in the single-concentration screen were retested in concentration-response. Due to high false-positive rates typically observed with loss-of-signal assays such as AUR-TPO, we also employed 2 additional assays in parallel to identify possible sources of nonspecific assay signal loss, enabling stratification of roughly 300 putative TPO inhibitors based upon selective AUR-TPO activity. A cell-free luciferase inhibition assay was used to identify nonspecific enzyme inhibition among the putative TPO inhibitors, and a cytotoxicity assay using a human cell line was used to estimate the cellular tolerance limit. Additionally, the TPO inhibition activities of 150 chemicals were compared between the AUR-TPO and an orthogonal peroxidase oxidat

The evolution of vision.

PubMed

Gehring, Walter J

2014-01-01

In this review, the evolution of vision is retraced from its putative origins in cyanobacteria to humans. Circadian oscillatory clocks, phototropism, and phototaxis require the capability to detect light. Photosensory proteins allow us to reconstruct molecular phylogenetic trees. The evolution of animal eyes leading from an ancestral prototype to highly complex image forming eyes can be deciphered on the basis of evolutionary developmental genetic experiments and comparative genomics. As all bilaterian animals share the same master control gene, Pax6, and the same retinal and pigment cell determination genes, we conclude that the different eye-types originated monophyletically and subsequently diversified by divergent, parallel, or convergent evolution. © 2012 Wiley Periodicals, Inc.

Tumour suppressor protein p53 regulates the stress activated bilirubin oxidase cytochrome P450 2A6

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

Hu, Hao, E-mail: hao.hu1@uqconnect.edu.au; Yu, Ting, E-mail: t.yu2@uq.edu.au; Arpiainen, Satu, E-mail: Satu.Juhila@orion.fi

2015-11-15

Human cytochrome P450 (CYP) 2A6 enzyme has been proposed to play a role in cellular defence against chemical-induced oxidative stress. The encoding gene is regulated by various stress activated transcription factors. This paper demonstrates that p53 is a novel transcriptional regulator of the gene. Sequence analysis of the CYP2A6 promoter revealed six putative p53 binding sites in a 3 kb proximate promoter region. The site closest to transcription start site (TSS) is highly homologous with the p53 consensus sequence. Transfection with various stepwise deletions of CYP2A6-5′-Luc constructs – down to − 160 bp from the TSS – showed p53 responsivenessmore » in p53 overexpressed C3A cells. However, a further deletion from − 160 to − 74 bp, including the putative p53 binding site, totally abolished the p53 responsiveness. Electrophoretic mobility shift assay with a probe containing the putative binding site showed specific binding of p53. A point mutation at the binding site abolished both the binding and responsiveness of the recombinant gene to p53. Up-regulation of the endogenous p53 with benzo[α]pyrene – a well-known p53 activator – increased the expression of the p53 responsive positive control and the CYP2A6-5′-Luc construct containing the intact p53 binding site but not the mutated CYP2A6-5′-Luc construct. Finally, inducibility of the native CYP2A6 gene by benzo[α]pyrene was demonstrated by dose-dependent increases in CYP2A6 mRNA and protein levels along with increased p53 levels in the nucleus. Collectively, the results indicate that p53 protein is a regulator of the CYP2A6 gene in C3A cells and further support the putative cytoprotective role of CYP2A6. - Highlights: • CYP2A6 is an immediate target gene of p53. • Six putative p53REs located on 3 kb proximate CYP2A6 promoter region. • The region − 160 bp from TSS is highly homologous with the p53 consensus sequence. • P53 specifically bind to the p53RE on the − 160 bp region. • HNF4α may interact with p53 in regulating CYP2A6 expression.« less

Reassessing direct-to-consumer portrayals of unproven stem cell therapies: is it getting better?

PubMed

Ogbogu, Ubaka; Rachul, Christen; Caulfield, Timothy

2013-05-01

To determine whether increased scrutiny of 'stem cell tourism' has resulted in changes to online claims by clinics that provide putative unproven stem cell treatments. We analyzed historical and current versions of clinics' websites. The study sample consisted of 18 websites included in a 2008 peer-reviewed study and an additional 12 clinics identified through the Google™ search engine. Our analysis revealed similarities between historical and current stem cell treatment offerings, claims, representations of risk, benefit and efficacy and attention to social, ethical and regulatory concerns. Claims and representations remain overly optimistic. Current websites provide more detailed descriptions of treatment procedures and outcomes and are more aesthetically appealing. Noteworthy trends in the movements and locations of clinics was observed. Increased scrutiny of stem cell tourism has not had much impact on the online claims of clinics that provide putative unproven stem cell treatments.

Undifferentiated embryonic cell transcription factor 1 (UTF1) and deleted in azoospermia-like (DAZL) expression in the testes of donkeys.

PubMed

Lee, Y S; Jung, H J; Yoon, M J

2017-04-01

Putative markers for each specific germ cell stage can be a useful tool to study the fate and functions of these cells. Undifferentiated embryonic cell transcription factor 1 (UTF1) is a putative marker for undifferentiated spermatogonia in humans, rats and horses. The deleted in azoospermia-like (DAZL) protein is also expressed by differentiated spermatogonia and primary spermatocytes in several species. However, whether the expression patterns of these molecular markers are identical and applicable to donkeys remains to be elucidated. The objective of this study was to investigate the expression patterns of UTF1 and DAZL in donkey testicular tissue, using immunohistochemistry (IHC). Testicular samples were collected from routine field castration of donkeys in Korea. The reproductive stages (pre- or post-puberty) of the testes were determined from the morphological characteristics of cross-sections of the seminiferous tubules. For IHC, the UTF1 and DAZL primary antibodies were diluted at 1:100 and 1:200, respectively. The immunolabelling revealed that UTF1 was expressed in approximately 50% of spermatogonia in the pre-pubertal stage, whereas its expression was limited to an early subset of spermatogonia in the post-pubertal stage. DAZL was expressed in some, but not all, spermatogonia in the pre-pubertal spermatogonia, and interestingly, its expression was also observed in spermatogonia and primary spermatocytes in the post-pubertal stage. Co-immunolabelling of the germ cells with both UTF1 and DAZL revealed three types of protein expression patterns at both reproductive stages, namely UTF1 only, DAZL only and both UTF1 and DAZL. These protein molecules were not expressed in Sertoli and Leydig cells. In conclusion, a co-immunolabelling system with UTF1 and DAZL antibodies may be used to identify undifferentiated (UTF1 only), differentiating (UTF1 and DAZL), and differentiated spermatogonia (DAZL only) in donkey testes. © 2017 Blackwell Verlag GmbH.

YAC contigs covering an 8-megabase region of 3p deleted in the small-cell lung cancer cell line U2020

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

Todd, S.; Bolin, R.; Drabkin, H.A.

1995-01-01

Somatic deletions of chromosome 3p occur at high frequencies in cancers of kidney, breast, cervix, head and neck, nasopharynx, and lung. The frequency of 3p deletion in lung cancer approaches 100% among small cell lesions and 70 to 80% in non-small cell lesions. This evidence strongly implies that one or more tumor suppressor genes of potentially widespread significance reside within the deleted region(s). Precise definition of the deleted target region(s) has been difficult due to the extensive area(s) lost and use of markers with low informativeness. However, improved definition remains essential to permit isolation of putative tumor suppressor genes frommore » 3p. The identification of several small, homozygous 3p deletions in lung cancer cell lines has provided a critical resource that will assist this search. The U2020 cell line contains a small homozygous deletion that maps to a very proximal region of 3p and includes the marker D3S3. We previously identified a subset of DNA markers located within the deleted region and determined their relative order by pulsed-field gel mapping studies. In the present report, we describe the development of YAC contigs that span the majority of the deleted region and link up to flanking markers on both sides. The centromere proximal portion of the contig crosses the breakpoint from an X;3 translocation located within 3p12 providing both location and orientation to the map. PCR-based (CA){sub n} microsatellite polymorphisms have been localized within and flanking the deletion region. These markers should greatly facilitate loss-of-heterozygosity studies of this region in human cancer. The contig provides a direct means for isolation of putative tumor suppressor genes from this segment of 3p. 51 refs., 3 figs., 3 tabs.« less

Mutations of the central tyrosines of putative cholesterol recognition amino acid consensus (CRAC) sequences modify folding, activity, and sterol-sensing of the human ABCG2 multidrug transporter.

PubMed

Gál, Zita; Hegedüs, Csilla; Szakács, Gergely; Váradi, András; Sarkadi, Balázs; Özvegy-Laczka, Csilla

2015-02-01

Human ABCG2 is a plasma membrane glycoprotein causing multidrug resistance in cancer. Membrane cholesterol and bile acids are efficient regulators of ABCG2 function, while the molecular nature of the sterol-sensing sites has not been elucidated. The cholesterol recognition amino acid consensus (CRAC, L/V-(X)(1-5)-Y-(X)(1-5)-R/K) sequence is one of the conserved motifs involved in cholesterol binding in several proteins. We have identified five potential CRAC motifs in the transmembrane domain of the human ABCG2 protein. In order to define their roles in sterol-sensing, the central tyrosines of these CRACs (Y413, 459, 469, 570 and 645) were mutated to S or F and the mutants were expressed both in insect and mammalian cells. We found that mutation in Y459 prevented protein expression; the Y469S and Y645S mutants lost their activity; while the Y570S, Y469F, and Y645F mutants retained function as well as cholesterol and bile acid sensitivity. We found that in the case of the Y413S mutant, drug transport was efficient, while modulation of the ATPase activity by cholesterol and bile acids was significantly altered. We suggest that the Y413 residue within a putative CRAC motif has a role in sterol-sensing and the ATPase/drug transport coupling in the ABCG2 multidrug transporter. Copyright © 2014. Published by Elsevier B.V.

humpty dumpty is required for developmental DNA amplification and cell proliferation in Drosophila.

PubMed

Bandura, Jennifer L; Beall, Eileen L; Bell, Maren; Silver, Hannah R; Botchan, Michael R; Calvi, Brian R

2005-04-26

The full complement of proteins required for the proper regulation of genome duplication are yet to be described. We employ a genetic DNA-replication model system based on developmental amplification of Drosophila eggshell (chorion) genes [1]. Hypomorphic mutations in essential DNA replication genes result in a distinct thin-eggshell phenotype owing to reduced amplification [2]. Here, we molecularly identify the gene, which we have named humpty dumpty (hd), corresponding to the thin-eggshell mutant fs(3)272-9 [3]. We confirm that hd is essential for DNA amplification in the ovary and show that it also is required for cell proliferation during development. Mosaic analysis of hd mutant cells during development and RNAi in Kc cells reveal that depletion of Hd protein results in severe defects in genomic replication and DNA damage. Most Hd protein is found in nuclear foci, and some may traverse the nuclear envelope. Consistent with a role in DNA replication, expression of Hd protein peaks during late G1 and S phase, and it responds to the E2F1/Dp transcription factor. Hd protein sequence is conserved from plants to humans, and published microarrays indicate that expression of its putative human ortholog also peaks at G1/S [4]. Our data suggest that hd defines a new gene family likely required for cell proliferation in all multicellular eukaryotes.

Invincible, but not invisible: imaging approaches toward in vivo detection of cancer stem cells.

PubMed

Hart, Lori S; El-Deiry, Wafik S

2008-06-10

With evidence emerging in support of a cancer stem-cell model of carcinogenesis, it is of paramount importance to identify and image these elusive cells in their natural environment. The cancer stem-cell hypothesis has the potential to explain unresolved questions of tumorigenesis, tumor heterogeneity, chemotherapeutic and radiation resistance, and even the metastatic phenotype. Intravital imaging of cancer stem cells could be of great value for determining prognosis, as well as monitoring therapeutic efficacy and influencing therapeutic protocols. Cancer stem cells represent a rare population of cells, as low as 0.1% of cells within a human tumor, and the phenotype of isolated cancer stem cells is easily altered when placed under in vitro conditions. This represents a challenge in studying cancer stem cells without manipulation or extraction from their natural environment. Advanced imaging techniques allow for the in vivo observation of physiological events at cellular resolution. Cancer stem-cell studies must take advantage of such technology to promote a better understanding of the cancer stem-cell model in relation to tumor growth and metastasis, as well as to potentially improve on the principles by which cancers are treated. This review examines the opportunities for in vivo imaging of putative cancer stem cells with regard to currently accepted cancer stem-cell characteristics and advanced imaging technologies.

Polyphosphate is a key factor for cell survival after DNA damage in eukaryotic cells.

PubMed

Bru, Samuel; Samper-Martín, Bàrbara; Quandt, Eva; Hernández-Ortega, Sara; Martínez-Laínez, Joan M; Garí, Eloi; Rafel, Marta; Torres-Torronteras, Javier; Martí, Ramón; Ribeiro, Mariana P C; Jiménez, Javier; Clotet, Josep

2017-09-01

Cells require extra amounts of dNTPs to repair DNA after damage. Polyphosphate (polyP) is an evolutionary conserved linear polymer of up to several hundred inorganic phosphate (Pi) residues that is involved in many functions, including Pi storage. In the present article, we report on findings demonstrating that polyP functions as a source of Pi when required to sustain the dNTP increment essential for DNA repair after damage. We show that mutant yeast cells without polyP produce less dNTPs upon DNA damage and that their survival is compromised. In contrast, when polyP levels are ectopically increased, yeast cells become more resistant to DNA damage. More importantly, we show that when polyP is reduced in HEK293 mammalian cell line cells and in human dermal primary fibroblasts (HDFa), these cells become more sensitive to DNA damage, suggesting that the protective role of polyP against DNA damage is evolutionary conserved. In conclusion, we present polyP as a molecule involved in resistance to DNA damage and suggest that polyP may be a putative target for new approaches in cancer treatment or prevention. Copyright © 2017 Elsevier B.V. All rights reserved.

MicroRNA-944 Affects Cell Growth by Targeting EPHA7 in Non-Small Cell Lung Cancer.

PubMed

Liu, Minxia; Zhou, Kecheng; Cao, Yi

2016-09-26

MicroRNAs (miRNAs) have critical roles in lung tumorigenesis and development. To determine aberrantly expressed miRNAs involved in non-small cell lung cancer (NSCLC) and investigate pathophysiological functions and mechanisms, we firstly carried out small RNA deep sequencing in NSCLC cell lines (EPLC-32M1, A549 and 801D) and a human immortalized cell line 16HBE, we then studied miRNA function by cell proliferation and apoptosis. cDNA microarray, luciferase reporter assay and miRNA transfection were used to investigate interaction between the miRNA and target gene. miR-944 was significantly down-regulated in NSCLC and had many putative targets. Moreover, the forced expression of miR-944 significantly inhibited the proliferation of NSCLC cells in vitro. By integrating mRNA expression data and miR-944-target prediction, we disclosed that EPHA7 was a potential target of miR-944, which was further verified by luciferase reporter assay and microRNA transfection. Our data indicated that miR-944 targets EPHA7 in NSCLC and regulates NSCLC cell proliferation, which may offer a new mechanism underlying the development and progression of NSCLC.

Neuroendocrine factors affecting the glycogen metabolism of purified Mytilus edulis glycogen cells: partial characterization of the putative glycogen mobilization hormone--demonstration of a factor that stimulates glycogen synthesis.

PubMed

Robbins, I; Lenoir, F; Mathieu, M

1991-04-01

A putative glycogen mobilizing hormone (GMH) from the marine mussel Mytilus edulis L. has been partially characterized. GMH activity is present in the cerebral ganglia and the hemolymph serum and promotes the mobilization of glycogen in isolated glycogen cells. The cerebral GMH is trypsin sensitive and partially heat labile and has an apparent molecular mass of greater than 20 kDa. Following fractionation of cerebral extracts by molecular mass, a second factor, with a molecular mass of ca. 1.5 kDa, was discovered. This factor stimulates post-incubation incorporation of 14C into glycogen in isolated glycogen cells.

Neisseria Heparin Binding Antigen is targeted by the human alternative pathway C3-convertase

PubMed Central

Di Fede, Martina; Biagini, Massimiliano; Cartocci, Elena; Parillo, Carlo; Greco, Alessandra; Martinelli, Manuele; Marchi, Sara; Pezzicoli, Alfredo; Delany, Isabel

2018-01-01

Neisserial Heparin Binding Antigen (NHBA) is a surface-exposed lipoprotein specific for Neisseria and constitutes one of the three main protein antigens of the Bexsero vaccine. Meningococcal and human proteases, cleave NHBA protein upstream or downstream of a conserved Arg-rich region, respectively. The cleavage results in the release of the C-terminal portion of the protein. The C-terminal fragment originating from the processing of meningococcal proteases, referred to as C2 fragment, exerts a toxic effect on endothelial cells altering the endothelial permeability. In this work, we reported that recombinant C2 fragment has no influence on the integrity of human airway epithelial cell monolayers, consistent with previous findings showing that Neisseria meningitidis traverses the epithelial barrier without disrupting the junctional structures. We showed that epithelial cells constantly secrete proteases responsible for a rapid processing of C2 fragment, generating a new fragment that does not contain the Arg-rich region, a putative docking domain reported to be essential for C2-mediated toxic effect. Moreover, we found that the C3-convertase of the alternative complement pathway is one of the proteases responsible for this processing. Overall, our data provide new insights on the cleavage of NHBA protein during meningococcal infection. NHBA cleavage may occur at different stages of the infection, and it likely has a different role depending on the environment the bacterium is interacting with. PMID:29579105

Mining novel effector proteins from the esophageal gland cells of Meloidogyne incognita

PubMed Central

Rutter, William B.; Hewezi, Tarek; Abubucker, Sahar; Maier, Tom R.; Huang, Guozhong; Mitreva, Makedonka; Hussey, Richard S.; Baum, Thomas J.

2014-01-01

Meloidogyne incognita is one of the most economically damaging plant pathogens in agriculture and horticulture. Identifying and characterizing the effector proteins, which M. incognita secretes into its host plants during infection, is an important step towards finding new ways to manage this pest. In this study we have identified the cDNAs for 18 putative effectors, i.e., proteins that have the potential to facilitate M. incognita parasitism of host plants. These putative effectors are secretory proteins that do not contain transmembrane domains and whose genes are specifically expressed in the secretory gland cells of the nematode, indicating that they are likely secreted from the nematode through its stylet. We have determined that in the plant cells, these putative effectors are likely to localize to the cytoplasm. Furthermore, the transcripts of many of these novel effectors are specifically up-regulated during different stages of the nematode’s life cycle, indicating that they function at specific stages during M. incognita parasitism. The predicted proteins showed little to no homology to known proteins from free-living nematode species, suggesting that they evolved recently to support the parasitic lifestyle. On the other hand, several of the effectors are part of gene families within the M. incognita genome as well as that of Meloidogyne hapla, which points to an important role that these putative effectors are playing in both parasites. With the discovery of these putative effectors we have increased our knowledge of the effector repertoire utilized by root-knot nematodes to infect, feed, and reproduce on their host plants. Future studies investigating the roles these proteins play in planta will help mitigate the effects of this damaging pest. PMID:24875667

Pro-apoptotic effect of a Mycoplasma hyopneumoniae putative type I signal peptidase on PK(15) swine cells.

PubMed

Paes, Jéssica A; Virginio, Veridiana G; Cancela, Martín; Leal, Fernanda M A; Borges, Thiago J; Jaeger, Natália; Bonorino, Cristina; Schrank, Irene S; Ferreira, Henrique B

2017-03-01

Mycoplasma hyopneumoniae is an economically significant swine pathogen that causes porcine enzootic pneumonia (PEP). Important processes for swine infection by M. hyopneumoniae depend on cell surface proteins, many of which are secreted by secretion pathways not completely elucidated so far. A putative type I signal peptidase (SPase I), a possible component of a putative Sec-dependent pathway, was annotated as a product of the sipS gene in the pathogenic M. hyopneumoniae 7448 genome. This M. hyopneumoniae putative SPase I (MhSPase I) displays only 14% and 23% of sequence identity/similarity to Escherichia coli bona fide SPase I, and, in complementation assays performed with a conditional E. coli SPase I mutant, only a partial restoration of growth was achieved with the heterologous expression of a recombinant MhSPase I (rMhSPase I). Considering the putative surface location of MhSPase I and its previously demonstrated capacity to induce a strong humoral response, we then assessed its potential to elicit a cellular and possible immunomodulatory response. In assays for immunogenicity assessment, rMhSPase I unexpectedly showed a cytotoxic effect on murine splenocytes. This cytotoxic effect was further confirmed using the swine epithelial PK(15) cell line in MTT and annexin V-flow cytometry assays, which showed that rMhSPase I induces apoptosis in a dose dependent-way. It was also demonstrated that this pro-apoptotic effect of rMhSPase I involves activation of a caspase-3 cascade. The potential relevance of the rMhSPase I pro-apoptotic effect for M. hyopneumoniae-host interactions in the context of PEP is discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

Mining novel effector proteins from the esophageal gland cells of Meloidogyne incognita.

PubMed

Rutter, William B; Hewezi, Tarek; Abubucker, Sahar; Maier, Tom R; Huang, Guozhong; Mitreva, Makedonka; Hussey, Richard S; Baum, Thomas J

2014-09-01

Meloidogyne incognita is one of the most economically damaging plant pathogens in agriculture and horticulture. Identifying and characterizing the effector proteins which M. incognita secretes into its host plants during infection is an important step toward finding new ways to manage this pest. In this study, we have identified the cDNAs for 18 putative effectors (i.e., proteins that have the potential to facilitate M. incognita parasitism of host plants). These putative effectors are secretory proteins that do not contain transmembrane domains and whose genes are specifically expressed in the secretory gland cells of the nematode, indicating that they are likely secreted from the nematode through its stylet. We have determined that, in the plant cells, these putative effectors are likely to localize to the cytoplasm. Furthermore, the transcripts of many of these novel effectors are specifically upregulated during different stages of the nematode's life cycle, indicating that they function at specific stages during M. incognita parasitism. The predicted proteins showed little to no homology to known proteins from free-living nematode species, suggesting that they evolved recently to support the parasitic lifestyle. On the other hand, several of the effectors are part of gene families within the M. incognita genome as well as that of M. hapla, which points to an important role that these putative effectors are playing in both parasites. With the discovery of these putative effectors, we have increased our knowledge of the effector repertoire utilized by root-knot nematodes to infect, feed on, and reproduce on their host plants. Future studies investigating the roles that these proteins play in planta will help mitigate the effects of this damaging pest.

Oral Mucosa Harbors a High Frequency of Endothelial Cells: A Novel Postnatal Cell Source for Angiogenic Regeneration.

PubMed

Zhou, Jian; Rogers, Jason H; Lee, Scott H; Sun, DongMing; Yao, Hai; Mao, Jeremy J; Kong, Kimi Y

2017-01-15

Endothelial progenitor cells/endothelial cells (EPCs/ECs) have great potential to treat pathological conditions such as cardiac infarction, muscle ischemia, and bone fractures, but isolation of EPC/ECs from existing cell sources is challenging due to their low EC frequency. We have isolated endothelial progenitor (EP)-like cells from rat oral mucosa and characterized their yield, immunophenotype, growth, and in vivo angiogenic potential. The frequency of EP-like cells derived from oral mucosa is thousands of folds higher than EPCs derived from donor-match bone marrow samples. EP-like cells from oral mucosa were positive for EC markers CD31, VE-Cadherin, and VEGFR2. Oral mucosa-derived EP-like cells displayed robust uptake of acetylated low-density lipoprotein and formed stable capillary networks in Matrigel. Subcutaneously implanted oral mucosa-derived EP-like cells anastomosed with host blood vessels, implicating their ability to elicit angiogenesis. Similar to endothelial colony-forming cells, EP-like cells from oral mucosa have a significantly higher proliferative rate than human umbilical vein endothelial cells. These findings identify a putative EPC source that is easily accessible in the oral cavity, potentially from discarded tissue specimens, and yet with robust yield and potency for angiogenesis in tissue and organ regeneration.

Oral Mucosa Harbors a High Frequency of Endothelial Cells: A Novel Postnatal Cell Source for Angiogenic Regeneration

PubMed Central

Zhou, Jian; Rogers, Jason H.; Lee, Scott H.; Sun, DongMing; Yao, Hai; Mao, Jeremy J.

2017-01-01

Endothelial progenitor cells/endothelial cells (EPCs/ECs) have great potential to treat pathological conditions such as cardiac infarction, muscle ischemia, and bone fractures, but isolation of EPC/ECs from existing cell sources is challenging due to their low EC frequency. We have isolated endothelial progenitor (EP)-like cells from rat oral mucosa and characterized their yield, immunophenotype, growth, and in vivo angiogenic potential. The frequency of EP-like cells derived from oral mucosa is thousands of folds higher than EPCs derived from donor-match bone marrow samples. EP-like cells from oral mucosa were positive for EC markers CD31, VE-Cadherin, and VEGFR2. Oral mucosa-derived EP-like cells displayed robust uptake of acetylated low-density lipoprotein and formed stable capillary networks in Matrigel. Subcutaneously implanted oral mucosa-derived EP-like cells anastomosed with host blood vessels, implicating their ability to elicit angiogenesis. Similar to endothelial colony-forming cells, EP-like cells from oral mucosa have a significantly higher proliferative rate than human umbilical vein endothelial cells. These findings identify a putative EPC source that is easily accessible in the oral cavity, potentially from discarded tissue specimens, and yet with robust yield and potency for angiogenesis in tissue and organ regeneration. PMID:27832737

[Merkel cell carcinoma: cutaneous manifestation of a highly malignant pre-/pro-B cell neoplasia? : Novel concept about the cellular origin of Merkel cell carcinoma].

PubMed

Sauer, C M; Chteinberg, E; Rennspiess, D; Kurz, A K; Zur Hausen, A

2017-03-01

Merkel cell carcinoma (MCC) is a relatively rare but highly malignant non-melanoma skin cancer of the elderly and immunosuppressed patients. The discovery of the Merkel cell polyomavirus (MCPyV) in 2008 significantly impacted the understanding of the etiopathogenesis of MCC. MCPyV is clonally integrated into the MCC genome and approximately 80% of MCC are MCPyV-positive. Recent results of clinical trials using blockade of the PD-1 immune modulatory pathway are promising for the future treatment of MCC. Despite this major progress of the past few years, the cellular origin of MCC still remains obscure. Based on histomorphology, gene expression profiling, and molecular analyses, we have recently hypothesized that MCC originates from pre‑/pro-B cells. Here we review putative cells of MCC, including Merkel cells, (epi‑)dermal stem cells, and pro‑/pre-B cells. In the present work, the focus is on the concept of pre‑/pro-B cells as the cellular origin of MCC, which might also impact the understanding of other human small cell malignancies of unknown cellular origin, such as small cell carcinomas of the lung and other anatomical locations. In addition, this concept might pave the way for novel treatment options, especially for advanced MCC.

C-mannosylation of R-spondin3 regulates its secretion and activity of Wnt/β-catenin signaling in cells.

PubMed

Fujiwara, Miho; Kato, Shintaro; Niwa, Yuki; Suzuki, Takehiro; Tsuchiya, Miyu; Sasazawa, Yukiko; Dohmae, Naoshi; Simizu, Siro

2016-08-01

R-spondin3 (Rspo3) is a secreted protein, which acts as an agonist of canonical Wnt/β-catenin signaling that plays an important role in embryonic development and homeostasis. In this study, we focused on C-mannosylation, a unique type of glycosylation, of human Rspo3. Rspo3 has two putative C-mannosylation sites at Trp(153) and Trp(156) ; however, it had been unclear whether these sites are C-mannosylated or not. We demonstrated that Rspo3 was C-mannosylated at both Trp(153) and Trp(156) by mass spectrometry. Using C-mannosylation-defective Rspo3 mutant-overexpressing cell lines, we found that C-mannosylation of Rspo3 promotes its secretion and activates Wnt/β-catenin signaling. © 2016 Federation of European Biochemical Societies.

Examination of Campylobacter jejuni putative adhesins leads to the identification of a new protein, designated FlpA, required for chicken colonization

USDA-ARS?s Scientific Manuscript database

Campylobacter jejuni colonization of chickens is dependent upon surface exposed proteins termed adhesins. Putative C. jejuni adhesins include CadF, CapA, JlpA, MOMP, PEB1, Cj1279c, and Cj1349c. We examined the genetic relatedness of ninety-seven C. jejuni isolates recovered from human, poultry, bo...

Mycobacterium tuberculosis genome-wide screen exposes multiple CD8+ T cell epitopes

PubMed Central

Hammond, A S; Klein, M R; Corrah, T; Fox, A; Jaye, A; McAdam, K P; Brookes, R H

2005-01-01

Mounting evidence suggests human leucocyte antigen (HLA) class I-restricted CD8+ T cells play a role in protective immunity against tuberculosis yet relatively few epitopes specific for the causative organism, Mycobacterium tuberculosis, are reported. Here a total genome-wide screen of M. tuberculosis was used to identify putative HLA-B*3501 T cell epitopes. Of 479 predicted epitopes, 13 with the highest score were synthesized and used to restimulate lymphocytes from naturally exposed HLA-B*3501 healthy individuals in cultured and ex vivo enzyme-linked immunospot (ELISPOT) assays for interferon (IFN)-γ. All 13 peptides elicited a response that varied considerably between individuals. For three peptides CD8+ T cell lines were expanded and four of the 13 were recognized permissively through the HLA-B7 supertype family. Although further testing is required we show the genome-wide screen to be feasible for the identification of unknown mycobacterial antigens involved in immunity against natural infection. While the mechanisms of protective immunity against M. tuberculosis infection remain unclear, conventional class I-restricted CD8+ T cell responses appear to be widespread throughout the genome. PMID:15762882

The Giardia cell cycle progresses independently of the anaphase-promoting complex

PubMed Central

Gourguechon, Stéphane; Holt, Liam J.; Cande, W. Zacheus

2013-01-01

Summary Most cell cycle regulation research has been conducted in model organisms representing a very small part of the eukaryotic domain. The highly divergent human pathogen Giardia intestinalis is ideal for studying the conservation of eukaryotic pathways. Although Giardia has many cell cycle regulatory components, its genome lacks all anaphase-promoting complex (APC) components. In the present study, we show that a single mitotic cyclin in Giardia is essential for progression into mitosis. Strikingly, Giardia cyclin B lacks the conserved N-terminal motif required for timely degradation mediated by the APC and ubiquitin conjugation. Expression of Giardia cyclin B in fission yeast is toxic, leading to a prophase arrest, and this toxicity is suppressed by the addition of a fission yeast degradation motif. Cyclin B is degraded during mitosis in Giardia cells, but this degradation appears to be independent of the ubiquitination pathway. Other putative APC substrates, aurora and polo-like kinases, also show no evidence of ubiquitination. This is the first example of mitosis not regulated by the APC and might reflect an evolutionary ancient form of cell cycle regulation. PMID:23525017

What Tumor Dynamics Modeling Can Teach us About Exploiting the Stem-Cell View for Better Cancer Treatment

PubMed Central

Day, Roger S

2015-01-01

The cancer stem cell hypothesis is that in human solid cancers, only a small proportion of the cells, the cancer stem cells (CSCs), are self-renewing; the vast majority of the cancer cells are unable to sustain tumor growth indefinitely on their own. In recent years, discoveries have led to the concentration, if not isolation, of putative CSCs. The evidence has mounted that CSCs do exist and are important. This knowledge may promote better understanding of treatment resistance, create opportunities to test agents against CSCs, and open up promise for a fresh approach to cancer treatment. The first clinical trials of new anti-CSC agents are completed, and many others follow. Excitement is mounting that this knowledge will lead to major improvements, even breakthroughs, in treating cancer. However, exploitation of this phenomenon may be more successful if informed by insights into the population dynamics of tumor development. We revive some ideas in tumor dynamics modeling to extract some guidance in designing anti-CSC treatment regimens and the clinical trials that test them. PMID:25780337

Endo-beta-N-acetylglucosaminidase, an enzyme involved in processing of free oligosaccharides in the cytosol.

PubMed

Suzuki, Tadashi; Yano, Keiichi; Sugimoto, Seiji; Kitajima, Ken; Lennarz, William J; Inoue, Sadako; Inoue, Yasuo; Emori, Yasufumi

2002-07-23

Formation of oligosaccharides occurs both in the cytosol and in the lumen of the endoplasmic reticulum (ER). Luminal oligosaccharides are transported into the cytosol to ensure that they do not interfere with proper functioning of the glycan-dependent quality control machinery in the lumen of the ER for newly synthesized glycoproteins. Once in the cytosol, free oligosaccharides are catabolized, possibly to maximize the reutilization of the component sugars. An endo-beta-N-acetylglucosaminidase (ENGase) is a key enzyme involved in the processing of free oligosaccharides in the cytosol. This enzyme activity has been widely described in animal cells, but the gene encoding this enzyme activity has not been reported. Here, we report the identification of the gene encoding human cytosolic ENGase. After 11 steps, the enzyme was purified 150,000-fold to homogeneity from hen oviduct, and several internal amino acid sequences were analyzed. Based on the internal sequence and examination of expressed sequence tag (EST) databases, we identified the human orthologue of the purified protein. The human protein consists of 743 aa and has no apparent signal sequence, supporting the idea that this enzyme is localized in the cytosol. By expressing the cDNA of the putative human ENGase in COS-7 cells, the enzyme activity in the soluble fraction was enhanced 100-fold over the basal level, confirming that the human gene identified indeed encodes for ENGase. Careful gene database surveys revealed the occurrence of ENGase homologues in Drosophila melanogaster, Caenorhabditis elegans, and Arabidopsis thaliana, indicating the broad occurrence of ENGase in higher eukaryotes. This gene was expressed in a variety of human tissues, suggesting that this enzyme is involved in basic biological processes in eukaryotic cells.

Human TSCM cell dynamics in vivo are compatible with long-lived immunological memory and stemness.

PubMed

Del Amo, Pedro Costa; Beneytez, Julio Lahoz; Boelen, Lies; Ahmed, Raya; Miners, Kelly L; Zhang, Yan; Roger, Laureline; Jones, Rhiannon E; Marraco, Silvia A Fuertes; Speiser, Daniel E; Baird, Duncan M; Price, David A; Ladell, Kristin; Macallan, Derek; Asquith, Becca

2018-06-22

Adaptive immunity relies on the generation and maintenance of memory T cells to provide protection against repeated antigen exposure. It has been hypothesised that a self-renewing population of T cells, named stem cell-like memory T (TSCM) cells, are responsible for maintaining memory. However, it is not clear if the dynamics of TSCM cells in vivo are compatible with this hypothesis. To address this issue, we investigated the dynamics of TSCM cells under physiological conditions in humans in vivo using a multidisciplinary approach that combines mathematical modelling, stable isotope labelling, telomere length analysis, and cross-sectional data from vaccine recipients. We show that, unexpectedly, the average longevity of a TSCM clone is very short (half-life < 1 year, degree of self-renewal = 430 days): far too short to constitute a stem cell population. However, we also find that the TSCM population is comprised of at least 2 kinetically distinct subpopulations that turn over at different rates. Whilst one subpopulation is rapidly replaced (half-life = 5 months) and explains the rapid average turnover of the bulk TSCM population, the half-life of the other TSCM subpopulation is approximately 9 years, consistent with the longevity of the recall response. We also show that this latter population exhibited a high degree of self-renewal, with a cell residing without dying or differentiating for 15% of our lifetime. Finally, although small, the population was not subject to excessive stochasticity. We conclude that the majority of TSCM cells are not stem cell-like but that there is a subpopulation of TSCM cells whose dynamics are compatible with their putative role in the maintenance of T cell memory.

MicroRNA miR-30 family regulates non-attachment growth of breast cancer cells

PubMed Central

2013-01-01

Background A subset of breast cancer cells displays increased ability to self-renew and reproduce breast cancer heterogeneity. The characterization of these so-called putative breast tumor-initiating cells (BT-ICs) may open the road for novel therapeutic strategies. As microRNAs (miRNAs) control developmental programs in stem cells, BT-ICs may also rely on specific miRNA profiles for their sustained activity. To explore the notion that miRNAs may have a role in sustaining BT-ICs, we performed a comprehensive profiling of miRNA expression in a model of putative BT-ICs enriched by non-attachment growth conditions. Results We found breast cancer cells grown under non-attachment conditions display a unique pattern of miRNA expression, highlighted by a marked low expression of miR-30 family members relative to parental cells. We further show that miR-30a regulates non-attachment growth. A target screening revealed that miR-30 family redundantly modulates the expression of apoptosis and proliferation-related genes. At least one of these targets, the anti-apoptotic protein AVEN, was able to partially revert the effect of miR-30a overexpression. Finally, overexpression of miR-30a in vivo was associated with reduced breast tumor progression. Conclusions miR30-family regulates the growth of breast cancer cells in non-attachment conditions. This is the first analysis of target prediction in a whole family of microRNAs potentially involved in survival of putative BT-ICs. PMID:23445407

Transfection and heat-inducible expression of molluscan promoter-luciferase reporter gene constructs in the Biomphalaria glabrata embryonic snail cell line.

PubMed

Yoshino, T P; Wu, X J; Liu, H D

1998-09-01

Studies were initiated to begin developing a genetic transformation system for cells derived from the freshwater gastropod, Biomphalaria glabrata, an intermediate host of the human blood fluke Schistosoma mansoni. Using a 70-kD heat-shock protein (HSP70) cDNA probe obtained from the B. glabrata embryonic (Bge) cell line, we cloned from Bge cells a complete HSP70 gene including a 1-kb genomic DNA fragment in its 5'-flanking region containing sequences indicative of a HSP promoter. Identified in the 5'-half (416 nucleotides) of this genomic fragment were TATA and CAAT boxes, two putative transcription initiation sites, and a series of palindromic DNA repeats with shared homology to the heat-shock element consensus sequence (Bge HSP70(0.5k) promoter). The 3'-half of this upstream flanking region was comprised of a 508-base intron located immediately 5' of the ATG start codon. To determine the functionality of the putative snail promoter sequence, Bge HSP promoter/luciferase (Luc) reporter gene constructs were introduced into Bge cells by N-(1-(2,3-dioleoyloxy) propyl)-N,N,N-trimethylammonium methylsulfate (DOTAP)-mediated transfection methods, and assayed for Luc activity 48 hr following a 1.5-hr heat-shock treatment (40 degrees C). Compared with control vectors or the Bge HSP70(0.5k/1.0k) promoter constructs at 26 degrees C, a 10- to 300-fold increase in Luc expression was obtained only in the Bge HSP70 promoter/Luc-transfected cells following heat-shock. Results of transfection experiments demonstrate that the Bge HSP70(0.5k) DNA segment contains appropriate promoter sequences for driving temperature-inducible gene expression in the Bge snail cell line. This report represents the first isolation and functional characterization of an inducible promoter from a freshwater gastropod mollusc. Successful transient expression of a foreign reporter gene in Bge cells using a homologous, inducible promoter sequence now paves the way for development of methods for stable integration and expression of snail genes of interest into the Bge cell line.

SND1, a component of RNA-induced silencing complex, is up-regulated in human colon cancers and implicated in early stage colon carcinogenesis.

PubMed

Tsuchiya, Naoto; Ochiai, Masako; Nakashima, Katsuhiko; Ubagai, Tsuneyuki; Sugimura, Takashi; Nakagama, Hitoshi

2007-10-01

Colon cancers have been shown to develop after accumulation of multiple genetic and epigenetic alterations with changes in global gene expression profiles, contributing to the establishment of widely diverse phenotypes. Transcriptional and posttranscriptional regulation of gene expression by small RNA species, such as the small interfering RNA and microRNA and the RNA-induced silencing complex (RISC), is currently drawing major interest with regard to cancer development. SND1, also called Tudor-SN and p100 and recently reported to be a component of RISC, is among the list of highly expressed genes in human colon cancers. In the present study, we showed remarkable up-regulation of SND1 mRNA in human colon cancer tissues, even in early-stage lesions, and also in colon cancer cell lines. When mouse Snd1 was stably overexpressed in IEC6 rat intestinal epithelial cells, contact inhibition was lost and cell growth was promoted, even after the cells became confluent. Intriguingly, IEC6 cells with high levels of Snd1 also showed an altered distribution of E-cadherin from the cell membrane to the cytoplasm, suggesting loss of cellular polarity. Furthermore, the adenomatous polyposis coli (Apc) protein was coincidentally down-regulated, with no significant changes in the Apc mRNA level. Immunohistochemical analysis using chemically induced colonic lesions developed in rats revealed overexpression of Snd1 not only in colon cancers but also in aberrant crypt foci, putative precancerous lesions of the colon. Up-regulation of SND1 may thus occur at a very early stage in colon carcinogenesis and contribute to the posttranscriptional regulation of key players in colon cancer development, including APC and beta-catenin.

Silencing of transposable elements may not be a major driver of regulatory evolution in primate iPSCs

PubMed Central

Zhao, Siming; Luo, Kaixuan; Pavlovic, Bryan J; Karimi, Mohammad M; Stephens, Matthew

2018-01-01

Transposable elements (TEs) comprise almost half of primate genomes and their aberrant regulation can result in deleterious effects. In pluripotent stem cells, rapidly evolving KRAB-ZNF genes target TEs for silencing by H3K9me3. To investigate the evolution of TE silencing, we performed H3K9me3 ChIP-seq experiments in induced pluripotent stem cells from 10 human and 7 chimpanzee individuals. We identified four million orthologous TEs and found the SVA and ERV families to be marked most frequently by H3K9me3. We found little evidence of inter-species differences in TE silencing, with as many as 82% of putatively silenced TEs marked at similar levels in humans and chimpanzees. TEs that are preferentially silenced in one species are a similar age to those silenced in both species and are not more likely to be associated with expression divergence of nearby orthologous genes. Our data suggest limited species-specificity of TE silencing across 6 million years of primate evolution. PMID:29648536

Updates in the Development of ImmunoRNases for the Selective Killing of Tumor Cells

PubMed Central

Jordaan, Sandra; Akinrinmade, Olusiji A.; Nachreiner, Thomas; Cremer, Christian; Naran, Krupa; Chetty, Shivan; Barth, Stefan

2018-01-01

Targeted cancer therapy includes, amongst others, antibody-based delivery of toxic payloads to selectively eliminate tumor cells. This payload can be either a synthetic small molecule drug composing an antibody-drug conjugate (ADC) or a cytotoxic protein composing an immunotoxin (IT). Non-human cytotoxic proteins, while potent, have limited clinical efficacy due to their immunogenicity and potential off-target toxicity. Humanization of the cytotoxic payload is essential and requires harnessing of potent apoptosis-inducing human proteins with conditional activity, which rely on targeted delivery to contact their substrate. Ribonucleases are attractive candidates, due to their ability to induce apoptosis by abrogating protein biosynthesis via tRNA degradation. In fact, several RNases of the pancreatic RNase A superfamily have shown potential as anti-cancer agents. Coupling of a human RNase to a humanized antibody or antibody derivative putatively eliminates the immunogenicity of an IT (now known as a human cytolytic fusion protein, hCFP). However, RNases are tightly regulated in vivo by endogenous inhibitors, controlling the ribonucleolytic balance subject to the cell’s metabolic requirements. Endogenous inhibition limits the efficacy with which RNase-based hCFPs induce apoptosis. However, abrogating the natural interaction with the natural inhibitors by mutation has been shown to significantly enhance RNase activity, paving the way toward achieving cytolytic potency comparable to that of bacterial immunotoxins. Here, we review the immunoRNases that have undergone preclinical studies as anti-cancer therapeutic agents. PMID:29510557

Identification of virulence determinants for endocarditis in Streptococcus sanguinis by signature-tagged mutagenesis.

PubMed

Paik, Sehmi; Senty, Lauren; Das, Sankar; Noe, Jody C; Munro, Cindy L; Kitten, Todd

2005-09-01

Streptococcus sanguinis is a gram-positive, facultative anaerobe and a normal inhabitant of the human oral cavity. It is also one of the most common agents of infective endocarditis, a serious endovascular infection. To identify virulence factors for infective endocarditis, signature-tagged mutagenesis (STM) was applied to the SK36 strain of S. sanguinis, whose genome is being sequenced. STM allows the large-scale creation, in vivo screening, and recovery of a series of mutants with altered virulence. Screening of 800 mutants by STM identified 38 putative avirulent and 5 putative hypervirulent mutants. Subsequent molecular analysis of a subset of these mutants identified genes encoding undecaprenol kinase, homoserine kinase, anaerobic ribonucleotide reductase, adenylosuccinate lyase, and a hypothetical protein. Virulence reductions ranging from 2-to 150-fold were confirmed by competitive index assays. One putatively hypervirulent strain with a transposon insertion in an intergenic region was identified, though increased virulence was not confirmed in competitive index assays. All mutants grew comparably to SK36 in aerobic broth culture except for the homoserine kinase mutant. Growth of this mutant was restored by the addition of threonine to the medium. Mutants containing an insertion or in-frame deletion in the anaerobic ribonucleotide reductase gene failed to grow under strictly anaerobic conditions. The results suggest that housekeeping functions such as cell wall synthesis, amino acid and nucleic acid synthesis, and the ability to survive under anaerobic conditions are important virulence factors in S. sanguinis endocarditis.

Identification of Virulence Determinants for Endocarditis in Streptococcus sanguinis by Signature-Tagged Mutagenesis†

PubMed Central

Paik, Sehmi; Senty, Lauren; Das, Sankar; Noe, Jody C.; Munro, Cindy L.; Kitten, Todd

2005-01-01

Streptococcus sanguinis is a gram-positive, facultative anaerobe and a normal inhabitant of the human oral cavity. It is also one of the most common agents of infective endocarditis, a serious endovascular infection. To identify virulence factors for infective endocarditis, signature-tagged mutagenesis (STM) was applied to the SK36 strain of S. sanguinis, whose genome is being sequenced. STM allows the large-scale creation, in vivo screening, and recovery of a series of mutants with altered virulence. Screening of 800 mutants by STM identified 38 putative avirulent and 5 putative hypervirulent mutants. Subsequent molecular analysis of a subset of these mutants identified genes encoding undecaprenol kinase, homoserine kinase, anaerobic ribonucleotide reductase, adenylosuccinate lyase, and a hypothetical protein. Virulence reductions ranging from 2-to 150-fold were confirmed by competitive index assays. One putatively hypervirulent strain with a transposon insertion in an intergenic region was identified, though increased virulence was not confirmed in competitive index assays. All mutants grew comparably to SK36 in aerobic broth culture except for the homoserine kinase mutant. Growth of this mutant was restored by the addition of threonine to the medium. Mutants containing an insertion or in-frame deletion in the anaerobic ribonucleotide reductase gene failed to grow under strictly anaerobic conditions. The results suggest that housekeeping functions such as cell wall synthesis, amino acid and nucleic acid synthesis, and the ability to survive under anaerobic conditions are important virulence factors in S. sanguinis endocarditis. PMID:16113327

Heterogeneity of signal transduction by Na-K-ATPase α-isoforms: role of Src interaction.

PubMed

Yu, Hui; Cui, Xiaoyu; Zhang, Jue; Xie, Joe X; Banerjee, Moumita; Pierre, Sandrine V; Xie, Zijian

2018-02-01

Of the four Na-K-ATPase α-isoforms, the ubiquitous α1 Na-K-ATPase possesses both ion transport and Src-dependent signaling functions. Mechanistically, we have identified two putative pairs of domain interactions between α1 Na-K-ATPase and Src that are critical for α1 signaling function. Our subsequent report that α2 Na-K-ATPase lacks these putative Src-binding sites and fails to carry on Src-dependent signaling further supported our proposed model of direct interaction between α1 Na-K-ATPase and Src but fell short of providing evidence for a causative role. This hypothesis was specifically tested here by introducing key residues of the two putative Src-interacting domains present on α1 but not α2 sequence into the α2 polypeptide, generating stable cell lines expressing this mutant, and comparing its signaling properties to those of α2-expressing cells. The mutant α2 was fully functional as a Na-K-ATPase. In contrast to wild-type α2, the mutant gained α1-like signaling function, capable of Src interaction and regulation. Consistently, the expression of mutant α2 redistributed Src into caveolin-1-enriched fractions and allowed ouabain to activate Src-mediated signaling cascades, unlike wild-type α2 cells. Finally, mutant α2 cells exhibited a growth phenotype similar to that of the α1 cells and proliferated much faster than wild-type α2 cells. These findings reveal the structural requirements for the Na-K-ATPase to function as a Src-dependent receptor and provide strong evidence of isoform-specific Src interaction involving the identified key amino acids. The sequences surrounding the putative Src-binding sites in α2 are highly conserved across species, suggesting that the lack of Src binding may play a physiologically important and isoform-specific role.

The cell wall hydrolase Pmp23 is important for assembly and stability of the division ring in Streptococcus pneumoniae.

PubMed

Jacq, Maxime; Arthaud, Christopher; Manuse, Sylvie; Mercy, Chryslène; Bellard, Laure; Peters, Katharina; Gallet, Benoit; Galindo, Jennifer; Doan, Thierry; Vollmer, Waldemar; Brun, Yves V; VanNieuwenhze, Michael S; Di Guilmi, Anne Marie; Vernet, Thierry; Grangeasse, Christophe; Morlot, Cecile

2018-05-15

Bacterial division is intimately linked to synthesis and remodeling of the peptidoglycan, a cage-like polymer that surrounds the bacterial cell, providing shape and mechanical resistance. The bacterial division machinery, which is scaffolded by the cytoskeleton protein FtsZ, includes proteins with enzymatic, structural or regulatory functions. These proteins establish a complex network of transient functional and/or physical interactions which preserve cell shape and cell integrity. Cell wall hydrolases required for peptidoglycan remodeling are major contributors to this mechanism. Consistent with this, their deletion or depletion often results in morphological and/or division defects. However, the exact function of most of them remains elusive. In this work, we show that the putative lysozyme activity of the cell wall hydrolase Pmp23 is important for proper morphology and cell division in the opportunistic human pathogen Streptococcus pneumoniae. Our data indicate that active Pmp23 is required for proper localization of the Z-ring and the FtsZ-positioning protein MapZ. In addition, Pmp23 localizes to the division site and interacts directly with the essential peptidoglycan synthase PBP2x. Altogether, our data reveal a new regulatory function for peptidoglycan hydrolases.

Morphological description of limbal epithelium: searching for stem cells crypts in the dog, cat, pig, cow, sheep and horse.

PubMed

Patruno, M; Perazzi, A; Martinello, T; Blaseotto, A; Di Iorio, E; Iacopetti, I

2017-06-01

The cornea provides protection and transparency to the eye, allowing an optimal sharpness view. In some pathological conditions the cornea is able to regenerate thanks to the presence of a stem cells reservoir present at the level of the transition area between cornea and sclera (limbus). Corneal cell therapies in Veterinary Medicine are really limited due to the lacking of knowledge about the anatomy of the limbal area, the putative presence of stem cells and their identification in domestic species. The aim of this study was to provide an overview of the main distinctive structural features of the sclero-corneal junction and conjunctival-corneal junction areas in some species of veterinary importance, using optic microscope observations of histological sections. The resulting data were compared with cornea from humans adapting protocols already used to identify stem cells by means of a specific cellular marker. We tested the expression of ΔNp63α isoform in the cornea basal cells, trying to correlate the distribution profile with areas of highly proliferative turnover. The results obtained from this study represent a first step towards the identification of a corneal stem cells reservoir in different animals.

Loss of Dnmt3a induces CLL and PTCL with distinct methylomes and transcriptomes in mice.

PubMed

Haney, Staci L; Upchurch, Garland M; Opavska, Jana; Klinkebiel, David; Appiah, Adams Kusi; Smith, Lynette M; Heavican, Tayla B; Iqbal, Javeed; Joshi, Shantaram; Opavsky, Rene

2016-09-28

Cytosine methylation of DNA is an epigenetic modification involved in the repression of genes that affect biological processes including hematopoiesis. It is catalyzed by DNA methyltransferases, one of which -DNMT3A- is frequently mutated in human hematologic malignancies. We have previously reported that Dnmt3a inactivation in hematopoietic stem cells results in chronic lymphocytic leukemia (CLL) and CD8-positive peripheral T cell lymphomas (PTCL) in EμSRα-tTA;Teto-Cre;Dnmt3a fl/fl ; Rosa26LOXP EGFP/EGFP (Dnmt3a Δ/Δ ) mice. The extent to which molecular changes overlap between these diseases is not clear. Using high resolution global methylation and expression analysis we show that whereas patterns of methylation and transcription in normal B-1a cells and CD8-positive T cells are similar, methylomes and transcriptomes in malignant B-1a and CD8+ T cells are remarkably distinct, suggesting a cell-type specific function for Dnmt3a in cellular transformation. Promoter hypomethylation in tumors was 10 times more frequent than hypermethylation, three times more frequent in CLL than PTCL and correlated better with gene expression than hypermethylation. Cross-species molecular comparison of mouse and human CLL and PTCL reveals significant overlaps and identifies putative oncogenic drivers of disease. Thus, Dnmt3a Δ/Δ mice can serve as a new mouse model to study CLL and PTCL in relevant physiological settings.

Comprehensive analysis of genome-wide DNA methylation across human polycystic ovary syndrome ovary granulosa cell.

PubMed

Xu, Jiawei; Bao, Xiao; Peng, Zhaofeng; Wang, Linlin; Du, Linqing; Niu, Wenbin; Sun, Yingpu

2016-05-10

Polycystic ovary syndrome (PCOS) affects approximately 7% of the reproductive-age women. A growing body of evidence indicated that epigenetic mechanisms contributed to the development of PCOS. The role of DNA modification in human PCOS ovary granulosa cell is still unknown in PCOS progression. Global DNA methylation and hydroxymethylation were detected between PCOS' and controls' granulosa cell. Genome-wide DNA methylation was profiled to investigate the putative function of DNA methylaiton. Selected genes expressions were analyzed between PCOS' and controls' granulosa cell. Our results showed that the granulosa cell global DNA methylation of PCOS patients was significant higher than the controls'. The global DNA hydroxymethylation showed low level and no statistical difference between PCOS and control. 6936 differentially methylated CpG sites were identified between control and PCOS-obesity. 12245 differential methylated CpG sites were detected between control and PCOS-nonobesity group. 5202 methylated CpG sites were significantly differential between PCOS-obesity and PCOS-nonobesity group. Our results showed that DNA methylation not hydroxymethylation altered genome-wide in PCOS granulosa cell. The different methylation genes were enriched in development protein, transcription factor activity, alternative splicing, sequence-specific DNA binding and embryonic morphogenesis. YWHAQ, NCF2, DHRS9 and SCNA were up-regulation in PCOS-obesity patients with no significance different between control and PCOS-nonobesity patients, which may be activated by lower DNA methylaiton. Global and genome-wide DNA methylation alteration may contribute to different genes expression and PCOS clinical pathology.

Putative contact ketoconazole shampoo-triggered pemphigus foliaceus in a dog.

PubMed

Sung, Hyun-Jeong; Yoon, In-Hwa; Kim, Jung-Hyun

2017-09-01

A 10-year-old spayed female cocker spaniel dog was referred for an evaluation of acute-onset generalized pustular cutaneous lesions following application of ketoconazole shampoo. Cytologic and histopathologic examinations of the lesions revealed intra-epidermal pustules with predominantly neutrophils and acantholytic cells. This is the first description of putative contact ketoconazole shampoo-triggered pemphigus foliaceus in a dog.

Putative contact ketoconazole shampoo-triggered pemphigus foliaceus in a dog

PubMed Central

Sung, Hyun-Jeong; Yoon, In-Hwa; Kim, Jung-Hyun

2017-01-01

A 10-year-old spayed female cocker spaniel dog was referred for an evaluation of acute-onset generalized pustular cutaneous lesions following application of ketoconazole shampoo. Cytologic and histopathologic examinations of the lesions revealed intra-epidermal pustules with predominantly neutrophils and acantholytic cells. This is the first description of putative contact ketoconazole shampoo-triggered pemphigus foliaceus in a dog. PMID:28878412

NKG2C zygosity influences CD94/NKG2C receptor function and the NK-cell compartment redistribution in response to human cytomegalovirus.

PubMed

Muntasell, Aura; López-Montañés, María; Vera, Andrea; Heredia, Gemma; Romo, Neus; Peñafiel, Judith; Moraru, Manuela; Vila, Joan; Vilches, Carlos; López-Botet, Miguel

2013-12-01

Human cytomegalovirus (HCMV) infection promotes a persistent expansion of a functionally competent NK-cell subset expressing the activating CD94/NKG2C receptor. Factors underlying the wide variability of this effect observed in HCMV-seropositive healthy individuals and exacerbated in immunocompromized patients are uncertain. A deletion of the NKG2C gene has been reported, and an apparent relation of NKG2C genotype with circulating NKG2C(+) NK-cell numbers was observed in HCMV(+) children. We have assessed the influence of NKG2C gene dose on the NK-cell repertoire in a cohort of young healthy adults (N = 130, median age 19 years). Our results revealed a relation of NKG2C copy number with surface receptor levels and with NKG2C(+) NK-cell numbers in HCMV(+) subjects, independently of HLA-E dimorphism. Functional studies showed quantitative differences in signaling (i.e. iCa(2+) influx), degranulation, and IL-15-dependent proliferation, in response to NKG2C engagement, between NK cells from NKG2C(+/+) and hemizygous subjects. These observations provide a mechanistic interpretation on the way the NKG2C genotype influences steady-state NKG2C(+) NK-cell numbers, further supporting an active involvement of the receptor in the HCMV-induced reconfiguration of the NK-cell compartment. The putative implications of NKG2C zygosity over viral control and other clinical variables deserve attention. © 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim.

Drug resistance is conferred on the model yeast Saccharomyces cerevisiae by expression of full-length melanoma-associated human ATP-binding cassette transporter ABCB5.

PubMed

Keniya, Mikhail V; Holmes, Ann R; Niimi, Masakazu; Lamping, Erwin; Gillet, Jean-Pierre; Gottesman, Michael M; Cannon, Richard D

2014-10-06

ABCB5, an ATP-binding cassette (ABC) transporter, is highly expressed in melanoma cells, and may contribute to the extreme resistance of melanomas to chemotherapy by efflux of anti-cancer drugs. Our goal was to determine whether we could functionally express human ABCB5 in the model yeast Saccharomyces cerevisiae, in order to demonstrate an efflux function for ABCB5 in the absence of background pump activity from other human transporters. Heterologous expression would also facilitate drug discovery for this important target. DNAs encoding ABCB5 sequences were cloned into the chromosomal PDR5 locus of a S. cerevisiae strain in which seven endogenous ABC transporters have been deleted. Protein expression in the yeast cells was monitored by immunodetection using both a specific anti-ABCB5 antibody and a cross-reactive anti-ABCB1 antibody. ABCB5 function in recombinant yeast cells was measured by determining whether the cells possessed increased resistance to known pump substrates, compared to the host yeast strain, in assays of yeast growth. Three ABCB5 constructs were made in yeast. One was derived from the ABCB5-β mRNA, which is highly expressed in human tissues but is a truncation of a canonical full-size ABC transporter. Two constructs contained full-length ABCB5 sequences: either a native sequence from cDNA or a synthetic sequence codon-harmonized for S. cerevisiae. Expression of all three constructs in yeast was confirmed by immunodetection. Expression of the codon-harmonized full-length ABCB5 DNA conferred increased resistance, relative to the host yeast strain, to the putative substrates rhodamine 123, daunorubicin, tetramethylrhodamine, FK506, or clorgyline. We conclude that full-length ABCB5 can be functionally expressed in S. cerevisiae and confers drug resistance.

HLA class I antibodies trigger increased adherence of monocytes to endothelial cells by eliciting an increase in endothelial P-selectin and, depending on subclass, by engaging FcγRs.

PubMed

Valenzuela, Nicole M; Mulder, Arend; Reed, Elaine F

2013-06-15

Ab-mediated rejection (AMR) of solid organ transplants is characterized by intragraft macrophages. It is incompletely understood how donor-specific Ab binding to graft endothelium promotes monocyte adhesion, and what, if any, contribution is made by the Fc region of the Ab. We investigated the mechanisms underlying monocyte recruitment by HLA class I (HLA I) Ab-activated endothelium. We used a panel of murine mAbs of different subclasses to crosslink HLA I on human aortic, venous, and microvascular endothelial cells and measured the binding of human monocytic cell lines and peripheral blood monocytes. Both anti-HLA I murine (m)IgG1 and mIgG2a induced endothelial P-selectin, which was required for monocyte adhesion to endothelium irrespective of subclass. mIgG2a but not mIgG1 could bind human FcγRs. Accordingly, HLA I mIgG2a but not mIgG1 treatment of endothelial cells significantly augmented recruitment, predominantly through FcγRI, and, to a lesser extent, FcγRIIa. Moreover, HLA I mIgG2a promoted firm adhesion of monocytes to ICAM-1 through Mac-1, which may explain the prominence of monocytes during AMR. We confirmed these observations using human HLA allele-specific mAbs and IgG purified from transplant patient sera. HLA I Abs universally elicit endothelial exocytosis leading to monocyte adherence, implying that P-selectin is a putative therapeutic target to prevent macrophage infiltration during AMR. Importantly, the subclass of donor-specific Ab may influence its pathogenesis. These results imply that human IgG1 and human IgG3 should have a greater capacity to trigger monocyte infiltration into the graft than IgG2 or IgG4 due to enhancement by FcγR interactions.

Tissue distribution of aryl hydrocarbon receptor in the intestine: Implication of putative roles in tumor suppression

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

Ikuta, Togo, E-mail: togo@cancer-c.pref.saitama.jp; Kurosumi, Masafumi, E-mail: mkurosumi@cancer-c.pref.saitama.jp; Yatsuoka, Toshimasa, E-mail: yatsuoka-gi@umin.ac.jp

Intestinal homeostasis is maintained by complex interactions between intestinal microorganisms and the gut immune system. Dysregulation of gut immunity may lead to inflammatory disorders and tumorigenesis. We previously have shown the tumor suppressive effects of aryl hydrocarbon receptor (AhR) in intestinal carcinogenesis. In the present study, we investigated AhR distribution in the mouse and human intestine by histochemical analysis. In the normal intestine, AhR was mainly localized in the stroma containing immune cells in the lamina propria and lymphoid follicles. On the other hand, in the tumor tissue from human colon cancer and that developed in Apc{sup Min/+}mice, AhR expressionmore » was elevated. AhR immunostaining was found in both stromal and tumor cells. Although AhR was localized in the cytoplasm of tumor cells in most cases, nuclear AhR was also observed in some. AhR knockdown using siRNA resulted in significant promotion of cell growth in colon cancer cell lines. Furthermore, AhR activation by AhR ligands supplemented in culture medium suppressed cell growth. Our study results suggest that tumor suppressive roles of AhR are estimated in two distinct ways: in normal tissue, AhR is associated with tumor prevention by regulating gut immunity, whereas in tumor cells, it is involved in growth suppression. - Highlights: • In the normal intestine, AhR was mainly localized in stroma containing immune cells. • In the tumor tissue, AhR expression was found in both stromal and tumor cells. • AhR knockdown promoted cell growth in colon cancer cell lines.« less

The protons of space and brain tumors II. Cellular and molecular considerations

NASA Astrophysics Data System (ADS)

Nagle, W. A.; Moss, A. J.; Dalrymple, G. V.; Cox, A. B.; Wigle, J. F.; Mitchell, J. C.

1989-05-01

An increased incidence of highly malignant gliomas, termed glioblastoma multiforme has been observed in Rhesus monkeys irradiated with 55 MeV protons, and in humans treated with therapeutic irradiation to the head. The results suggest a radiation etiology for these tumors. In this paper, we review briefly some characteristics of glioma tumors, and summarize the genetic changes associated with malignant gliomas in experimental animals and in humans. The genetic abnormalities include cytogenetic alterations, and changes in the structure and expression of specific oncogenes. We discuss the potential for these genetic changes to contribute to several putative mechanism leading to aberrant growth stimulation and, ultimately, to tumorigenesis. In addition, we review briefly some recent data concerning the molecular nature of radiation-induced somatic cell mutation and oncogene activation, and discuss the significance of these results for the radiation etiology of malignant gliomas. Finally, some implications of these results are discussed in relation to human radiation exposure in space.

Cysteine cathepsin S processes leptin, inactivating its biological activity.

PubMed

Oliveira, Marcela; Assis, Diego M; Paschoalin, Thaysa; Miranda, Antonio; Ribeiro, Eliane B; Juliano, Maria A; Brömme, Dieter; Christoffolete, Marcelo Augusto; Barros, Nilana M T; Carmona, Adriana K

2012-08-01

Leptin is a 16  kDa hormone mainly produced by adipocytes that plays an important role in many biological events including the regulation of appetite and energy balance, atherosclerosis, osteogenesis, angiogenesis, the immune response, and inflammation. The search for proteolytic enzymes capable of processing leptin prompted us to investigate the action of cysteine cathepsins on human leptin degradation. In this study, we observed high cysteine peptidase expression and hydrolytic activity in white adipose tissue (WAT), which was capable of degrading leptin. Considering these results, we investigated whether recombinant human cysteine cathepsins B, K, L, and S were able to degrade human leptin. Mass spectrometry analysis revealed that among the tested enzymes, cathepsin S exhibited the highest catalytic activity on leptin. Furthermore, using a Matrigel assay, we observed that the leptin fragments generated by cathepsin S digestion did not exhibit angiogenic action on endothelial cells and were unable to inhibit food intake in Wistar rats after intracerebroventricular administration. Taken together, these results suggest that cysteine cathepsins may be putative leptin activity regulators in WAT.

Plasmacytoid dendritic cells (PDC) are the major DC subset innately producing cytokines in human lymph nodes.

PubMed

Cox, Karina; North, Margaret; Burke, Michael; Singhal, Hemant; Renton, Sophie; Aqel, Nayef; Islam, Sabita; Knight, Stella C

2005-11-01

Plasmacytoid dendritic cells (PDC) constitute a distinct subset of DC found in human peripheral lymph nodes (LN), but little is known about their function. Cell suspensions were prepared from tumor draining LN (n=20) and control LN (n=11) of women undergoing surgical resection for primary breast cancer and elective surgery for benign conditions, respectively. Using four-color flow cytometry, human leukocyte antigen-DR+ DC subsets were identified phenotypically. The proportions and numbers of cells innately producing interleukin (IL)-4, IL-10, IL-12, and interferon-gamma (IFN-gamma) were also measured from intracellular accumulation of cytokine after blocking with monensin. All flow cytometry data were collected without compensation and were compensated off-line using the Winlist algorithm (Verity software). This package also provided the subtraction program to calculate percentage positive cells and intensity of staining. PDC (CD11c-, CD123+) expressed more cytokines than did myeloid DC (CD11c+) or CD1a+ putative "migratory" DC (P<0.001). LN PDC from patients with a good prognosis (px; n=11) demonstrated a relative increase in IL-12 and IFN-gamma expression (median IL-10:IL-12 ratio=0.78 and median IL-4:IFN-gamma ratio=0.7), and PDC from LN draining poor px cancer (n=9) showed a relative increase in IL-10 and IL-4 expression (median IL-10:IL-12 ratio=1.31 and median IL-4:IFN-gamma ratio=2.6). The difference in IL-4:IFN-gamma expression between good and poor px cancer groups was significant (P<0.05). Thus, PDC innately producing cytokines were identified in cell suspensions from human LN, and the character of PDC cytokine secretion may differ between two breast cancer prognostic groups. We speculate that a shift towards PDC IL-10 and IL-4 expression could promote tumor tolerance in LN draining poor px breast cancer.

Differential regulation of protease activated receptor-1 and tissue plasminogen activator expression by shear stress in vascular smooth muscle cells

NASA Technical Reports Server (NTRS)

Papadaki, M.; Ruef, J.; Nguyen, K. T.; Li, F.; Patterson, C.; Eskin, S. G.; McIntire, L. V.; Runge, M. S.

1998-01-01

Recent studies have demonstrated that vascular smooth muscle cells are responsive to changes in their local hemodynamic environment. The effects of shear stress on the expression of human protease activated receptor-1 (PAR-1) and tissue plasminogen activator (tPA) mRNA and protein were investigated in human aortic smooth muscle cells (HASMCs). Under conditions of low shear stress (5 dyn/cm2), PAR-1 mRNA expression was increased transiently at 2 hours compared with stationary control values, whereas at high shear stress (25 dyn/cm2), mRNA expression was decreased (to 29% of stationary control; P<0.05) at all examined time points (2 to 24 hours). mRNA half-life studies showed that this response was not due to increased mRNA instability. tPA mRNA expression was decreased (to 10% of stationary control; P<0.05) by low shear stress after 12 hours of exposure and was increased (to 250% of stationary control; P<0.05) after 24 hours at high shear stress. The same trends in PAR-1 mRNA levels were observed in rat smooth muscle cells, indicating that the effects of shear stress on human PAR-1 were not species-specific. Flow cytometry and ELISA techniques using rat smooth muscle cells and HASMCs, respectively, provided evidence that shear stress exerted similar effects on cell surface-associated PAR-1 and tPA protein released into the conditioned media. The decrease in PAR-1 mRNA and protein had functional consequences for HASMCs, such as inhibition of [Ca2+] mobilization in response to thrombin stimulation. These data indicate that human PAR-1 and tPA gene expression are regulated differentially by shear stress, in a pattern consistent with their putative roles in several arterial vascular pathologies.

Lineage-Specific Genome Architecture Links Enhancers and Non-coding Disease Variants to Target Gene Promoters.

PubMed

Javierre, Biola M; Burren, Oliver S; Wilder, Steven P; Kreuzhuber, Roman; Hill, Steven M; Sewitz, Sven; Cairns, Jonathan; Wingett, Steven W; Várnai, Csilla; Thiecke, Michiel J; Burden, Frances; Farrow, Samantha; Cutler, Antony J; Rehnström, Karola; Downes, Kate; Grassi, Luigi; Kostadima, Myrto; Freire-Pritchett, Paula; Wang, Fan; Stunnenberg, Hendrik G; Todd, John A; Zerbino, Daniel R; Stegle, Oliver; Ouwehand, Willem H; Frontini, Mattia; Wallace, Chris; Spivakov, Mikhail; Fraser, Peter

2016-11-17

Long-range interactions between regulatory elements and gene promoters play key roles in transcriptional regulation. The vast majority of interactions are uncharted, constituting a major missing link in understanding genome control. Here, we use promoter capture Hi-C to identify interacting regions of 31,253 promoters in 17 human primary hematopoietic cell types. We show that promoter interactions are highly cell type specific and enriched for links between active promoters and epigenetically marked enhancers. Promoter interactomes reflect lineage relationships of the hematopoietic tree, consistent with dynamic remodeling of nuclear architecture during differentiation. Interacting regions are enriched in genetic variants linked with altered expression of genes they contact, highlighting their functional role. We exploit this rich resource to connect non-coding disease variants to putative target promoters, prioritizing thousands of disease-candidate genes and implicating disease pathways. Our results demonstrate the power of primary cell promoter interactomes to reveal insights into genomic regulatory mechanisms underlying common diseases. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Functional domains of the poliovirus receptor

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

Koike, Satoshi; Ise, Iku; Nomoto, Akio

1991-05-15

A number of mutant cDNAs of the human poliovirus receptor were constructed to identify essential regions of the molecule as the receptor. All mutant cDNAs carrying the sequence coding for the entire N-terminal immunoglobulin-like domain (domain I) confer permissiveness for poliovirus to mouse L cells, but a mutant cDNA lacking the sequence for domain I does not. The transformants permissive for poliovirus were able to bind the virus and were also recognized by monoclonal antibody D171, which competes with poliovirus for the cellular receptor. These results strongly suggest that the poliovirus binding site resides in domain I of the receptor.more » Mutant cDNAs for the sequence encoding the intracellular peptide were also constructed and expressed in mouse L cells. Susceptibility of these cells to poliovirus revealed that the entire putative cytoplasmic domain is not essential for virus infection. Thus, the cytoplasmic domain of the molecule appears not to play a role in the penetration of poliovirus.« less

Neuronal Activity Promotes Glioma Growth through Neuroligin-3 Secretion.

PubMed

Venkatesh, Humsa S; Johung, Tessa B; Caretti, Viola; Noll, Alyssa; Tang, Yujie; Nagaraja, Surya; Gibson, Erin M; Mount, Christopher W; Polepalli, Jai; Mitra, Siddhartha S; Woo, Pamelyn J; Malenka, Robert C; Vogel, Hannes; Bredel, Markus; Mallick, Parag; Monje, Michelle

2015-05-07

Active neurons exert a mitogenic effect on normal neural precursor and oligodendroglial precursor cells, the putative cellular origins of high-grade glioma (HGG). By using optogenetic control of cortical neuronal activity in a patient-derived pediatric glioblastoma xenograft model, we demonstrate that active neurons similarly promote HGG proliferation and growth in vivo. Conditioned medium from optogenetically stimulated cortical slices promoted proliferation of pediatric and adult patient-derived HGG cultures, indicating secretion of activity-regulated mitogen(s). The synaptic protein neuroligin-3 (NLGN3) was identified as the leading candidate mitogen, and soluble NLGN3 was sufficient and necessary to promote robust HGG cell proliferation. NLGN3 induced PI3K-mTOR pathway activity and feedforward expression of NLGN3 in glioma cells. NLGN3 expression levels in human HGG negatively correlated with patient overall survival. These findings indicate the important role of active neurons in the brain tumor microenvironment and identify secreted NLGN3 as an unexpected mechanism promoting neuronal activity-regulated cancer growth. Copyright © 2015 Elsevier Inc. All rights reserved.

Beclin-1 deficiency in the murine ovary results in the reduction of progesterone production to promote preterm labor.

PubMed

Gawriluk, Thomas R; Ko, CheMyong; Hong, Xiaoman; Christenson, Lane K; Rucker, Edmund B

2014-10-07

Autophagy is an important cellular process that serves as a companion pathway to the ubiquitin-proteasome system to degrade long-lived proteins and organelles to maintain cell homeostasis. Although initially characterized in yeast, autophagy is being realized as an important regulator of development and disease in mammals. Beclin1 (Becn1) is a putative tumor suppressor gene that has been shown to undergo a loss of heterozygosity in 40-75% of human breast, ovarian, and prostate cancers. Because Becn1 is a key regulator of autophagy, we sought to investigate its role in female reproduction by using a conditional knockout approach in mice. We find that pregnant females lacking Becn1 in the ovarian granulosa cell population have a defect in progesterone production and a subsequent preterm labor phenotype. Luteal cells in this model exhibit defective autophagy and a failure to accumulate lipid droplets needed for steroidogenesis. Collectively, we show that Becn1 provides essential functions in the ovary that are essential for mammalian reproduction.

Angiotensin-converting enzyme in epithelial and neuroepithelial cells.

PubMed

Defendini, R; Zimmerman, E A; Weare, J A; Alhenc-Gelas, F; Erdös, E G

1983-07-01

Angiotensin-converting enzyme (CE) occurs in three types of cell: endothelial, epithelial, and neuroepithelial. In all three, it appears to be bound to plasma membrane. With antisera to the human enzyme, CE is demonstrated in paraffin sections on the apical surface of epithelial cells in the proximal tubule of the kidney, the mucosa of the small intestine, the syncytial trophoblast of the placenta, and the choroid plexus. Epithelial CE is characteristically found on microvillous surfaces in contact with an effluent, well placed to act on substrate in flux. In the brain, CE occurs in nerve fibers and terminals, mainly mesiobasally and in basal ganglia. Mesiobasal CE coincides with other components of the renin-angiotensin system (RAS) in the choroid/ventricular fluid, the subfornical organ, and the magnocellular neurosecretory system of the hypothalamus. Extrapyramidal CE, however, may not be related to the RAS. In the substantia nigra and the globus pallidus, the enzyme has the same cellular distribution as two putative neuromodulators, substance P and enkephalin, the latter a known substrate of CE.

Construction of a 780-kb PAC, BAC, and cosmid contig encompassing the minimal critical deletion involved in B cell lymphocytic leukemia at 13q14.3

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

Bouyge-Moreau, I.; Rondeau, G.; Andre, M.T.

A putative tumor suppressor gene involved in B cell chronic lymphocytic leukemia (B-CLL) was mapped to human chromosome 13q14.3 close to the genetic markers D13S25 and D13S319. We constructed a 780-kb-long contig composed of cosmids, bacterial artificial chromosomes, and bacteriophage PI-derived artificial chromosomes that provides essential information and tools for the positional cloning of this gene. The contig contains both flanking markers as well as several additional genetic markers, three ESTs, and one potential CpG island. In addition, using one B-CLL patient, we characterized a small internal deleted region of 550 kb. Comparing this deletion with other recently published deletionsmore » narrows the minimally deleted area to less than 100 kb in our physical map. This deletion core region should contain all or part of the disrupted in B cell malignancies tumor suppressor gene. 27 refs., 3 figs.« less

Insights into Cdc13 Dependent Telomere Length Regulation

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

M Mason; E Skordalakes

Cdc13 is a single stranded telomere binding protein that specifically localizes to the telomere ends of budding yeasts and is essential for cell viability. It caps the ends of chromosomes thus preventing chromosome end-to-end fusions and exonucleolytic degradation, events that could lead to genomic instability and senescence, the hallmark of aging. Cdc13 is also involved in telomere length regulation by recruiting or preventing access of telomerase to the telomeric overhang. Recruitment of telomerase to the telomeres for G-strand extension is required for continuous cell division, while preventing its access to the telomeres through capping the chromosome ends prevents mitotic eventsmore » that could lead to cell immortality, the hall mark of carcinogenesis. Cdc13 and its putative homologues human CTC1 and POT1 are therefore key to many biological processes directly associated with life extension and cancer prevention and can be viewed as an ideal target for cancer and age related therapies.« less

Using reporter gene assays to identify cis regulatory differences between humans and chimpanzees.

PubMed

Chabot, Adrien; Shrit, Ralla A; Blekhman, Ran; Gilad, Yoav

2007-08-01

Most phenotypic differences between human and chimpanzee are likely to result from differences in gene regulation, rather than changes to protein-coding regions. To date, however, only a handful of human-chimpanzee nucleotide differences leading to changes in gene regulation have been identified. To hone in on differences in regulatory elements between human and chimpanzee, we focused on 10 genes that were previously found to be differentially expressed between the two species. We then designed reporter gene assays for the putative human and chimpanzee promoters of the 10 genes. Of seven promoters that we found to be active in human liver cell lines, human and chimpanzee promoters had significantly different activity in four cases, three of which recapitulated the gene expression difference seen in the microarray experiment. For these three genes, we were therefore able to demonstrate that a change in cis influences expression differences between humans and chimpanzees. Moreover, using site-directed mutagenesis on one construct, the promoter for the DDA3 gene, we were able to identify three nucleotides that together lead to a cis regulatory difference between the species. High-throughput application of this approach can provide a map of regulatory element differences between humans and our close evolutionary relatives.

The Aeromonas caviae AHA0618 gene modulates cell length and influences swimming and swarming motility

PubMed Central

Lowry, Rebecca C; Parker, Jennifer L; Kumbhar, Ramhari; Mesnage, Stephane; Shaw, Jonathan G; Stafford, Graham P

2015-01-01

Aeromonas caviae is motile via a polar flagellum in liquid culture, with a lateral flagella system used for swarming on solid surfaces. The polar flagellum also has a role in cellular adherence and biofilm formation. The two subunits of the polar flagellum, FlaA and FlaB, are posttranslationally modified by O-linked glycosylation with pseudaminic acid on 6–8 serine and threonine residues within the central region of these proteins. This modification is essential for the formation of the flagellum. Aeromonas caviae possesses the simplest set of genes required for bacterial glycosylation currently known, with the putative glycosyltransferase, Maf1, being described recently. Here, we investigated the role of the AHA0618 gene, which shares homology (37% at the amino acid level) with the central region of a putative deglycosylation enzyme (HP0518) from the human pathogen Helicobacter pylori, which also glycosylates its flagellin and is proposed to be part of a flagellin deglycosylation pathway. Phenotypic analysis of an AHA0618 A. caviae mutant revealed increased swimming and swarming motility compared to the wild-type strain but without any detectable effects on the glycosylation status of the polar flagellins when analyzed by western blot analysis or mass spectroscopy. Bioinformatic analysis of the protein AHA0618, demonstrated homology to a family of l,d-transpeptidases involved in cell wall biology and peptidoglycan cross-linking (YkuD-like). Scanning electron microscopy (SEM) and fluorescence microscopy analysis of the wild-type and AHA0618-mutant A. caviae strains revealed the mutant to be subtly but significantly shorter than wild-type cells; a phenomenon that could be recovered when either AHA0618 or H. pylori HP0518 were introduced. We can therefore conclude that AHA0618 does not affect A. caviae behavior by altering polar flagellin glycosylation levels but is likely to have a role in peptidoglycan processing at the bacterial cell wall, consequently altering cell length and hence influencing motility. PMID:25515520

CRISPR-Cas9 induced mutations along de novo purine synthesis in HeLa cells result in accumulation of individual enzyme substrates and affect purinosome formation.

PubMed

Baresova, Veronika; Krijt, Matyas; Skopova, Vaclava; Souckova, Olga; Kmoch, Stanislav; Zikanova, Marie

2016-11-01

Purines are essential molecules for nucleic acid synthesis and are the most common carriers of chemical energy in all living organisms. The cellular pool of purines is maintained by the balance between their de novo synthesis (DNPS), recycling and degradation. DNPS includes ten reactions catalysed by six enzymes. To date, two genetically determined disorders of DNPS enzymes have been described, and the existence of other defects manifested by neurological symptoms and the accumulation of DNPS intermediates in bodily fluids is highly presumable. In the current study, we prepared specific recombinant DNPS enzymes and used them for the biochemical preparation of their commercially unavailable substrates. These compounds were used as standards for the development and validation of quantitative liquid chromatography-tandem mass spectrometry (LC-MS/MS). To simulate manifestations of known and putative defects of DNPS we prepared CRISPR-Cas9 genome-edited HeLa cells deficient for the individual steps of DNPS (CR-cells), assessed the substrates accumulation in cell lysates and growth media and tested how the mutations affect assembly of the purinosome, the multi-enzyme complex of DNPS enzymes. In all model cell lines with the exception of one, an accumulation of the substrate(s) for the knocked out enzyme was identified. The ability to form the purinosome was reduced. We conclude that LC-MS/MS analysis of the dephosphorylated substrates of DNPS enzymes in bodily fluids is applicable in the selective screening of the known and putative DNPS disorders. This approach should be considered in affected individuals with neurological and neuromuscular manifestations of unknown aetiology. Prepared in vitro human model systems can serve in various studies that aim to provide a better characterization and understanding of physiology and pathology of DNPS, to study the role of each DNPS protein in the purinosome formation and represent an interesting way for the screening of potential therapeutic agents. Copyright © 2016 Elsevier Inc. All rights reserved.

Minocycline, a putative neuroprotectant, co-administered with doxorubicin-cyclophosphamide chemotherapy in a xenograft model of triple-negative breast cancer

PubMed Central

Himmel, Lauren E.; Lustberg, Maryam B.; DeVries, A. Courtney; Poi, Ming; Chen, Ching-Shih; Kulp, Samuel K.

2016-01-01

Minocycline is purported to have neuroprotective properties in experimental models of some human neurologic diseases, and has therefore been identified as a putative neuroprotectant for chemotherapy-induced cognitive impairment (CICI) in breast cancer patients. However, because its mechanism of action is believed to be mediated through anti-inflammatory, anti-apoptotic, and anti-oxidant pathways, co-administration of minocycline with chemotherapeutic agents has the potential to reduce the efficacy of anticancer drugs. The objective of this study is to evaluate the effect of minocycline on the activity of the AC chemotherapeutic regimen (Adriamycin [doxorubicin], Cytoxan [cyclophosphamide]) in in vitro and in vivo models of triple-negative breast cancer (TNBC). Clonogenic and methylthiazol tetrazolium (MTT) assays were used to assess survival and viability in two TNBC cell lines treated with increasing concentrations of AC in the presence or absence of minocycline. Biomarkers of apoptosis, cell stress, and DNA damage were evaluated by western blot. The in vivo effects of AC and minocycline, each alone and in combination, were assessed in a xenograft model of TNBC in female athymic nude mice by weekly tumor volume measurement, body and organ weight measurement, and histopathology. Apoptosis and proliferation were characterized by immunohistochemistry in the xenografts tumors. Brains from tumor-bearing mice were evaluated for microglial activation, glial scars, and the proportion of neural progenitor cells. Data from these in vitro and in vivo studies demonstrate that minocycline does not diminish the cytotoxic and tumor-suppressive effects of this chemotherapeutic drug combination in TNBC cells. Moreover, minocycline appeared to prevent the reduction in doublecortin-positive neural progenitor cells observed in AC-treated mice. We posit that minocycline may be useful clinically for its reported neuroprotective activity in breast cancer patients receiving AC without loss of chemotherapeutic efficacy. PMID:27555377

Minocycline, a putative neuroprotectant, co-administered with doxorubicin-cyclophosphamide chemotherapy in a xenograft model of triple-negative breast cancer.

PubMed

Himmel, Lauren E; Lustberg, Maryam B; DeVries, A Courtney; Poi, Ming; Chen, Ching-Shih; Kulp, Samuel K

2016-10-01

Minocycline is purported to have neuroprotective properties in experimental models of some human neurologic diseases, and has therefore been identified as a putative neuroprotectant for chemotherapy-induced cognitive impairment (CICI) in breast cancer patients. However, because its mechanism of action is believed to be mediated through anti-inflammatory, anti-apoptotic, and anti-oxidant pathways, co-administration of minocycline with chemotherapeutic agents has the potential to reduce the efficacy of anticancer drugs. The objective of this study is to evaluate the effect of minocycline on the activity of the AC chemotherapeutic regimen (Adriamycin [doxorubicin], Cytoxan [cyclophosphamide]) in in vitro and in vivo models of triple-negative breast cancer (TNBC). Clonogenic and methylthiazol tetrazolium (MTT) assays were used to assess survival and viability in two TNBC cell lines treated with increasing concentrations of AC in the presence or absence of minocycline. Biomarkers of apoptosis, cell stress, and DNA damage were evaluated by western blot. The in vivo effects of AC and minocycline, each alone and in combination, were assessed in a xenograft model of TNBC in female athymic nude mice by weekly tumor volume measurement, body and organ weight measurement, and histopathology. Apoptosis and proliferation were characterized by immunohistochemistry in the xenografts tumors. Brains from tumor-bearing mice were evaluated for microglial activation, glial scars, and the proportion of neural progenitor cells. Data from these in vitro and in vivo studies demonstrate that minocycline does not diminish the cytotoxic and tumor-suppressive effects of this chemotherapeutic drug combination in TNBC cells. Moreover, minocycline appeared to prevent the reduction in doublecortin-positive neural progenitor cells observed in AC-treated mice. We posit that minocycline may be useful clinically for its reported neuroprotective activity in breast cancer patients receiving AC without loss of chemotherapeutic efficacy. Copyright © 2016 Elsevier GmbH. All rights reserved.

Comparative transcriptome analysis links distinct peritoneal tumor spread types, miliary and non-miliary, with putative origin, tubes and ovaries, in high grade serous ovarian cancer.

PubMed

Auer, Katharina; Bachmayr-Heyda, Anna; Aust, Stefanie; Grunt, Thomas W; Pils, Dietmar

2017-03-01

High grade serous ovarian cancer (HGSOC) is characterized by extensive local, i.e. peritoneal, tumor spread, manifested in two different clinical presentations, miliary (many millet sized peritoneal implants) and non-miliary (few large exophytically growing peritoneal nodes), and an overall unfavorable outcome. HGSOC is thought to arise from fallopian tube secretory epithelial cells, via so called serous tubal intraepithelial carcinomas (STICs) but an ovarian origin was never ruled out for at least some cases. Comparative transcriptome analyses of isolated tumor cells from fresh HGSOC tissues and (immortalized) ovarian surface epithelial and fallopian tube secretory epithelial cell lines revealed a close relation between putative origin and tumor spread characteristic, i.e. miliary from tubes and non-miliary from ovaries. The latter were characterized by more mesenchymal cell characteristics, more adaptive tumor immune infiltration, and a favorable overall survival. Several molecular sub-classification systems (Crijns' overall survival signature, Yoshihara's subclasses, and a collagen-remodeling signature) seem to already indicate origin. Putative origin alone is a significant independent predictor for HGSOC outcome, validated in independent patient cohorts. Characteristics of both spread types could guide development of new targeted therapeutics, which are urgently needed. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Dynamics of excitatory and inhibitory networks are differentially altered by selective attention.

PubMed

Snyder, Adam C; Morais, Michael J; Smith, Matthew A

2016-10-01

Inhibition and excitation form two fundamental modes of neuronal interaction, yet we understand relatively little about their distinct roles in service of perceptual and cognitive processes. We developed a multidimensional waveform analysis to identify fast-spiking (putative inhibitory) and regular-spiking (putative excitatory) neurons in vivo and used this method to analyze how attention affects these two cell classes in visual area V4 of the extrastriate cortex of rhesus macaques. We found that putative inhibitory neurons had both greater increases in firing rate and decreases in correlated variability with attention compared with putative excitatory neurons. Moreover, the time course of attention effects for putative inhibitory neurons more closely tracked the temporal statistics of target probability in our task. Finally, the session-to-session variability in a behavioral measure of attention covaried with the magnitude of this effect. Together, these results suggest that selective targeting of inhibitory neurons and networks is a critical mechanism for attentional modulation. Copyright © 2016 the American Physiological Society.

Dynamics of excitatory and inhibitory networks are differentially altered by selective attention

PubMed Central

Snyder, Adam C.; Morais, Michael J.

2016-01-01

Inhibition and excitation form two fundamental modes of neuronal interaction, yet we understand relatively little about their distinct roles in service of perceptual and cognitive processes. We developed a multidimensional waveform analysis to identify fast-spiking (putative inhibitory) and regular-spiking (putative excitatory) neurons in vivo and used this method to analyze how attention affects these two cell classes in visual area V4 of the extrastriate cortex of rhesus macaques. We found that putative inhibitory neurons had both greater increases in firing rate and decreases in correlated variability with attention compared with putative excitatory neurons. Moreover, the time course of attention effects for putative inhibitory neurons more closely tracked the temporal statistics of target probability in our task. Finally, the session-to-session variability in a behavioral measure of attention covaried with the magnitude of this effect. Together, these results suggest that selective targeting of inhibitory neurons and networks is a critical mechanism for attentional modulation. PMID:27466133

NG2/CSPG4-collagen type VI interplays putatively involved in the microenvironmental control of tumour engraftment and local expansion.

PubMed

Cattaruzza, Sabrina; Nicolosi, Pier Andrea; Braghetta, Paola; Pazzaglia, Laura; Benassi, Maria Serena; Picci, Piero; Lacrima, Katia; Zanocco, Daniela; Rizzo, Erika; Stallcup, William B; Colombatti, Alfonso; Perris, Roberto

2013-06-01

In soft-tissue sarcoma patients, enhanced expression of NG2/CSPG4 proteoglycan in pre-surgical primary tumours predicts post-surgical metastasis formation and thereby stratifies patients into disease-free survivors and patients destined to succumb to the disease. Both primary and secondary sarcoma lesions also up-regulate collagen type VI, a putative extracellular matrix ligand of NG2, and this matrix alteration potentiates the prognostic impact of NG2. Enhanced constitutive levels of the proteoglycan in isolated sarcoma cells closely correlate with a superior engraftment capability and local growth in xenogenic settings. This apparent NG2-associated malignancy was also corroborated by the diverse tumorigenic behaviour in vitro and in vivo of immunoselected NG2-expressing and NG2-deficient cell subsets, by RNAi-mediated knock down of endogenous NG2, and by ectopic transduction of full-length or deletion constructs of NG2. Cells with modified expression of NG2 diverged in their interaction with purified Col VI, matrices supplemented with Col VI, and cell-free matrices isolated from wild-type and Col VI null fibroblasts. The combined use of dominant-negative NG2 mutant cells and purified domain fragments of the collagen allowed us to pinpoint the reciprocal binding sites within the two molecules and to assert the importance of this molecular interaction in the control of sarcoma cell adhesion and motility. The NG2-mediated binding to Col VI triggered activation of convergent cell survival- and cell adhesion/migration-promoting signal transduction pathways, implicating PI-3K as a common denominator. Thus, the findings point to an NG2-Col VI interplay as putatively involved in the regulation of the cancer cell-host microenvironment interactions sustaining sarcoma progression.

Human body scents: do they influence our behavior?

PubMed

Mildner, Sophie; Buchbauer, Gerhard

2013-11-01

Pheromonal communication in the animal world has been of great research interest for a long time. While extraordinary discoveries in this field have been made, the importance of the human sense of smell was of far lower interest. Humans are seen as poor smellers and therefore research about human olfaction remains quite sparse compared with other animals. Nevertheless amazing achievements have been made during the past 15 years. This is a collection of available data on this topic and a controversial discussion on the role of putative human pheromones in our modem way of living. While the focus was definitely put on behavioral changes evoked by putative human pheromones this article also includes other important aspects such as the possible existence of a human vomeronasal organ. If pheromones do have an influence on human behavior there has to be a receptor organ. How are human body scents secreted and turned into odorous substances? And how can con-specifics detect those very odors and transmit them to the brain? Apart from that the most likely candidates for human pheromones are taken on account and their impact on human behavior is shown in various detail.

The nucleotide sequence and a first generation gene transfer vector of species B human adenovirus serotype 3.

PubMed

Sirena, Dominique; Ruzsics, Zsolt; Schaffner, Walter; Greber, Urs F; Hemmi, Silvio

2005-12-20

Human adenovirus (Ad) serotype 3 causes respiratory infections. It is considered highly virulent, accounting for about 13% of all Ad isolates. We report here the complete Ad3 DNA sequence of 35,343 base pairs (GenBank accession DQ086466). Ad3 shares 96.43% nucleotide identity with Ad7, another virulent subspecies B1 serotype, and 82.56 and 62.75% identity with the less virulent species B2 Ad11 and species C Ad5, respectively. The genomic organization of Ad3 is similar to the other human Ads comprising five early transcription units, E1A, E1B, E2, E3, and E4, two delayed early units IX and IVa2, and the major late unit, in total 39 putative and 7 hypothetical open reading frames. A recombinant E1-deleted Ad3 was generated on a bacterial artificial chromosome. This prototypic virus efficiently transduced CD46-positive rodent and human cells. Our results will help in clarifying the biology and pathology of adenoviruses and enhance therapeutic applications of viral vectors in clinical settings.

microRNA in Human Reproduction.

PubMed

Eisenberg, Iris; Kotaja, Noora; Goldman-Wohl, Debra; Imbar, Tal

2015-01-01

microRNAs constitute a large family of approximately 21-nucleotide-long, noncoding RNAs. They emerged more than 20 years ago as key posttranscriptional regulators of gene expression. The regulatory role of these small RNA molecules has recently begun to be explored in the human reproductive system. microRNAs have been shown to play an important role in control of reproductive functions, especially in the processes of oocyte maturation, folliculogenesis, corpus luteum function, implantation, and early embryonic development. Knockout of Dicer, the cytoplasmic enzyme that cleaves the pre-miRNA to its mature form, results in postimplantation embryonic lethality in several animal models, attributing to these small RNA vital functions in reproduction and development. Another intriguing characteristic of microRNAs is their presence in body fluids in a remarkably stable form that is protected from endogenous RNase activity. In this chapter we will describe the current knowledge on microRNAs, specifically relating to human gonadal cells. We will focus on their role in the ovarian physiologic process and ovulation dysfunction, regulation of spermatogenesis and male fertility, and putative involvement in human normal and aberrant trophoblast differentiation and invasion through the process of placentation.

Heat shock 70-kDa protein 8 isoform 1 is expressed on the surface of human embryonic stem cells and downregulated upon differentiation.

PubMed

Son, Yeon Sung; Park, Jae Hyun; Kang, Young Kook; Park, Jin-Sung; Choi, Hong Seo; Lim, Ji Young; Lee, Jeoung Eun; Lee, Jung Bok; Ko, Myoung Seok; Kim, Yong-Sam; Ko, Jeong-Heon; Yoon, Hyun Soo; Lee, Kwang-Woong; Seong, Rho Hyun; Moon, Shin Yong; Ryu, Chun Jeih; Hong, Hyo Jeong

2005-01-01

The cell-surface markers used routinely to define the undifferentiated state and pluripotency of human embryonic stem cells (hESCs) are those used in mouse embryonic stem cells (mESCs) because of a lack of markers directly originated from hESC itself. To identify more hESC-specific cell-surface markers, we generated a panel of monoclonal antibodies (MAbs) by immunizing the irradiated cell clumps of hESC line Miz-hES1, and selected 26 MAbs that were able to bind to Miz-hES1 cells but not to mESCs, mouse embryonic fibroblast cells, and STO cells. Most antibodies did not bind to human neural progenitor cells derived from the Miz-hES1 cells, either. Of these, MAb 20-202S (IgG1, kappa) immunoprecipitated a cell-surface protein of 72-kDa from the lysate of biotin-labeled Miz-hES1 cells, which was identified to be heat shock 70-kDa protein 8 isoform 1 (HSPA8) by quadrupole time-of-flight tandem mass spectrometry. Immunocytochemical analyses proved that the HSPA8 protein was also present on the surface of hESC lines Miz-hES4, Miz-hES6, and HSF6. Two-color flow cytometric analysis of Miz-hES1 and HSF6 showed the coexpression of the HSPA8 protein with other hESC markers such as stage-specific embryonic antigen 3 (SSEA3), SSEA4, TRA-1-60, and TRA-1-81. Flow cytometric and Western blot analyses using various cells showed that MAb 20-202S specifically bound to the HSPA8 protein on the surface of Miz-hES1, contrary to other anti-HSP70 antibodies examined. Furthermore, the surface expression of the HSPA8 protein on Miz-hES1 was markedly downregulated upon differentiation. These data indicate that a novel MAb 20-202S recognizes the HSPA8 protein on the surface of hESCs and suggest that the HSPA8 protein is a putative cell-surface marker for undifferentiated hESCs.

Mechanisms of asbestos-induced squamous metaplasia in tracheobronchial epithelial cells.

PubMed Central

Cameron, G; Woodworth, C D; Edmondson, S; Mossman, B T

1989-01-01

Within 1 to 4 weeks after exposure to asbestos, differentiated rodent and human tracheobronchial epithelial cells in organ culture undergo squamous metaplasia, a putative preneoplastic lesion characterized by conversion of mucociliary cell types to keratinizing cells. The exogenous addition of retinal acetate (RA) to culture medium of hamster tracheal organ cultures reverses preestablished, asbestos-induced squamous metaplasia, although data suggest that the effectiveness of RA decreases as the length of time between exposure to asbestos and initial application of RA increases. alpha-Difluoromethylornithine (DFMO), an irreversible inhibitor of ornithine decarboxylase (ODC), inhibits squamous metaplasia caused by asbestos or vitamin A deficiency, whereas addition of methylglyoxal bis(guanylhydrazone) (MGBG), a structural analog of spermidine and inhibitor of S-adenosylmethionine decarboxylase, causes an enhancement of metaplasia under both circumstances. Basal cell hyperplasia and increased incorporation of 3H-thymidine by tracheal epithelial cells also are seen after addition of the polyamines, putrescine or spermidine, to tracheal organ cultures, an observation supporting the importance of polyamines in the development of this lesion. The use of retinoids and inhibitors of ODC could be promising as preventive and/or therapeutic approaches for individuals at high risk for development of asbestos-associated diseases. PMID:2924752

PigZ, a TetR/AcrR family repressor, modulates secondary metabolism via the expression of a putative four-component resistance-nodulation-cell-division efflux pump, ZrpADBC, in Serratia sp. ATCC 39006.

PubMed

Gristwood, Tamzin; Fineran, Peter C; Everson, Lee; Salmond, George P C

2008-07-01

The Gram-negative enterobacterium, Serratia sp. ATCC 39006 synthesizes several secondary metabolites, including prodigiosin (Pig) and a carbapenem antibiotic (Car). A complex hierarchical network of regulatory proteins control Pig and Car production. In this study we characterize a TetR family regulator, PigZ, which represses transcription of a divergently transcribed putative resistance-nodulation-cell-division (RND) efflux pump, encoded by zrp (PigZ repressed pump) ADBC, via direct binding to the zrpA-pigZ intergenic region. Unusually, this putative RND pump contains two predicted membrane fusion proteins (MFPs), ZrpA and ZrpD. A mutation in pigZ resulted in multiple phenotypic changes, including exoenzyme production, motility and differential regulation of Pig and Car production. A polar suppressor mutation, within zrpA, restored all tested phenotypes to parental strain levels, indicating that the changes observed are due to the increase in expression of ZrpADBC in the absence of the repressor, PigZ. Genomic deletions of zrpA and zrpD indicate that the MFP ZrpD, but not ZrpA, is essential for activity of the putative pump. Bioinformatic analysis revealed that putative RND efflux pumps encoding two MFP components are not uncommon, particularly among plant-associated, Gram-negative bacteria. In addition, based on phylogenetic analysis, we propose that these pairs of MFPs consist of two distinct subtypes.

Molecular cloning of a novel receptor tyrosine kinase, tif, highly expressed in human ovary and testis.

PubMed

Dai, W; Pan, H; Hassanain, H; Gupta, S L; Murphy, M J

1994-03-01

Using a combination of polymerase chain reaction and conventional cDNA library screening approaches, we have cloned and characterized a putative receptor tyrosine kinase termed tif. The extracellular domain of tif has an immunoglobulin-like loop and a fibronectin type III structure. The intracellular domain contains a tyrosine kinase domain. Compared with ryk, a ubiquitously expressed receptor tyrosine kinase, tif expression is tissue-specific with human ovary and testis containing the highest amount of tif mRNA. Many other tested human tissues such as heart, liver, pancreas and thymus do not contain detectable levels of tif mRNA. The molecular cloning and characterization of tif cDNA will facilitate the identification of a potential ligand(s) for the putative receptor and the study of its biological role.

Localization and functional consequences of a direct interaction between TRIOBP-1 and hERG proteins in the heart.

PubMed

Jones, David K; Johnson, Ashley C; Roti Roti, Elon C; Liu, Fang; Uelmen, Rebecca; Ayers, Rebecca A; Baczko, Istvan; Tester, David J; Ackerman, Michael J; Trudeau, Matthew C; Robertson, Gail A

2018-03-22

Reduced levels of the cardiac human (h)ERG ion channel protein and the corresponding repolarizing current I Kr can cause arrhythmia and sudden cardiac death, but the underlying cellular mechanisms controlling hERG surface expression are not well understood. Here, we identified TRIOBP-1, an F-actin-binding protein previously associated with actin polymerization, as a putative hERG-interacting protein in a yeast-two hybrid screen of a cardiac library. We corroborated this interaction by performing Förster resonance energy transfer (FRET) in HEK293 cells and co-immunoprecipitation in HEK293 cells and native cardiac tissue. TRIOBP-1 overexpression reduced hERG surface expression and current density, whereas reducing TRIOBP-1 expression via shRNA knockdown resulted in increased hERG protein levels. Immunolabeling in rat cardiomyocytes showed that native TRIOBP-1 colocalized predominantly with myosin-binding protein C and secondarily with rat ERG. In human stem cell-derived cardiomyocytes, TRIOBP-1 overexpression caused intracellular co-sequestration of hERG signal, reduced native I Kr and disrupted action potential repolarization. Ca 2+ currents were also somewhat reduced and cell capacitance was increased. These findings establish that TRIOBP-1 interacts directly with hERG and can affect protein levels, I Kr magnitude and cardiac membrane excitability. © 2018. Published by The Company of Biologists Ltd.

Oncostatic action of melatonin: facts and question marks.

PubMed

Pawlikowski, Marek; Winczyk, Katarzyna; Karasek, Michal

2002-04-01

The paper presents the data concerning the in vivo effects of melatonin on experimentally-induced tumors in animals and the in vitro effects on animal and human tumor cells. The majority of experimental tumors responded to the melatonin treatment with growth inhibition. However, some negative or opposite results (i.e. stimulation of tumor instead of inhibition) were also reported. Some of the negative results can be attributed to the improper timing of melatonin administration. Melatonin was also shown to inhibit the growth of several animal and human tumor cell lines in vitro. On the basis of these experiments, a hypothesis of the oncostatic action of melatonin was put forward. The mechanism of the postulated action is complex and probably includes: 1) modulation of the endocrine system; 2) modulation of the immune system; 3) the direct oncostatic action of melatonin on tumor cells. The latter includes the recently discovered anti-oxidative action which probably plays an important role in the countering the DNA damage during the radiation challenge or the exposure to chemical carcinogens. It also includes the antiproliferative and pro-apoptotic effects exerted via melatonin receptors expressed by tumor cells. The involvement of the membrane melatonin receptors is mainly assumed. However, the recent data from our and other laboratories suggest also the involvement of RZR/ROR receptors (the putative melatonin nuclear receptors) in both melatonin-induced proliferation inhibition and apoptosis.