184 results on '"Marco Tripodi"'
Search Results
152. Motor antagonism exposed by spatial segregation and timing of neurogenesis
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Anna E. Stepien, Marco Tripodi, and Silvia Arber
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Male ,Mice, 129 Strain ,Time Factors ,Spatial segregation ,Interneuron ,genetic structures ,Neurogenesis ,Sensory system ,Walking ,Biology ,Mice ,03 medical and health sciences ,0302 clinical medicine ,Interneurons ,medicine ,Animals ,Muscle, Skeletal ,030304 developmental biology ,Progenitor ,Motor Neurons ,0303 health sciences ,Multidisciplinary ,Proprioception ,musculoskeletal, neural, and ocular physiology ,Neuroanatomical Tract-Tracing Techniques ,Extremities ,Anatomy ,Spinal cord ,musculoskeletal system ,Mice, Inbred C57BL ,medicine.anatomical_structure ,Spinal Cord ,nervous system ,Synapses ,Female ,Nerve Net ,Neuroscience ,030217 neurology & neurosurgery - Abstract
Walking is a key motor behaviour of limbed animals, executed by contraction of functionally antagonistic muscle groups during swing and stance phases. Nevertheless, neuronal circuits regulating the activation of antagonistic extensor-flexor muscles remain poorly understood. Here we use monosynaptically restricted trans-synaptic viruses to elucidate premotor anatomical substrates for extensor-flexor control in mice. We observe a medio-lateral spatial segregation between extensor and flexor premotor interneurons in the dorsal spinal cord. These premotor interneuron populations are derived from common progenitor domains, but segregate by timing of neurogenesis. We find that proprioceptive sensory feedback from the periphery is targeted to medial extensor premotor populations and is required for extensor-specific connectivity profiles during development. Our findings provide evidence for a discriminating anatomical basis of antagonistic circuits at the level of premotor interneurons, and point to synaptic input and developmental ontogeny as key factors in the establishment of circuits regulating motor behavioural dichotomy.
- Published
- 2011
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153. Inhibition of interferon alpha signalling through the JAK-STAT pathway in HCV transgenic mice
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Marco Tripodi, Darius Moradpour, Alex Blindenbacher, Markus H. Heim, Nicola Lamonica, Hubert E. Blum, Simone Stutvoet, and Francois H.T. Duong
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Genetically modified mouse ,Signalling ,Hepatology ,Gastroenterology ,Cancer research ,JAK-STAT signaling pathway ,Alpha interferon ,Biology - Published
- 2001
154. 990 LIVER STEM CELL INVOLVEMENT IN HEPATIC FIBROSIS ONSET AND PROGRESSION
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Alessandra Marchetti, Alice Conigliaro, Marco Tripodi, F Garibaldi, Laura Amicone, and Carla Cicchini
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Pathology ,medicine.medical_specialty ,Hepatology ,business.industry ,medicine ,Liver Stem Cell ,business ,Hepatic fibrosis - Published
- 2010
155. Recognition efficiency of the hepatitis B virus polyadenylation signals is tissue specific in transgenic mice
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Marco Giorgio, Laura Amicone, Laura Pozzi, Marco Tripodi, Stefano Colloca, and Sabina Perfumo
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Gene Expression Regulation, Viral ,Hepatitis B virus ,Polyadenylation ,Transgene ,Immunology ,Mice, Transgenic ,Regulatory Sequences, Nucleic Acid ,medicine.disease_cause ,Microbiology ,Virus ,Mice ,Open Reading Frames ,Structure-Activity Relationship ,Virology ,Gene expression ,medicine ,Animals ,Tissue Distribution ,RNA, Messenger ,RNA Processing, Post-Transcriptional ,Enhancer ,biology ,Chromosome Mapping ,biology.organism_classification ,Molecular biology ,Mice, Inbred C57BL ,Open reading frame ,Hepadnaviridae ,Mice, Inbred DBA ,Insect Science ,Poly A ,Research Article - Abstract
The hepatitis B virus genome contains a unique polyadenylation (TATAAA) signal which is differentially utilized in the formation of the various hepatitis B virus transcripts. A head-to-tail multiple-copy insertion of a viral fragment comprising the viral enhancer, the X promoter, the X open reading frame, and the viral poly(A) signal in transgenic mice allowed us to monitor tissue-specific differences in the expression of transcripts initiating from the X promoter. These transcripts are efficiently processed at the first polyadenylation site in the liver, while in the kidney, the brain, and the testis, a portion of the transcripts covers two copies of the transgene, since only the second polyadenylation site is properly recognized. As discussed in this article, this observation suggests a tissue-specific distribution of cellular factors involved in polyadenylation.
- Published
- 1992
156. Disruption of the LF-A1 and LF-B1 binding sites in the human alpha-1-antitrypsin gene has a differential effect during development in transgenic mice
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Riccardo Cortese, Marco Tripodi, Nigel Vivian, Robin Lovell-Badge, Catherine M. Abbott, Tripodi, M., Abbott, C., Vivian, N., Cortese, Riccardo, and LOVELL BADGE, R.
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Chloramphenicol O-Acetyltransferase ,Aging ,Transcription, Genetic ,Response element ,Mutant ,Mice, Transgenic ,Biology ,General Biochemistry, Genetics and Molecular Biology ,Mice ,chemistry.chemical_compound ,Transcription (biology) ,Animals ,Humans ,Hepatocyte Nuclear Factor 1-alpha ,Binding site ,Promoter Regions, Genetic ,Molecular Biology ,Transcription factor ,Gene ,Hepatocyte Nuclear Factor 1-beta ,Binding Sites ,General Immunology and Microbiology ,General Neuroscience ,Nuclear Proteins ,Promoter ,DNA ,Blotting, Northern ,Cosmids ,Molecular biology ,DNA-Binding Proteins ,Retinol-Binding Proteins ,chemistry ,alpha 1-Antitrypsin ,Hepatocyte Nuclear Factor 1 ,Mutation ,RNA ,Plasmids ,Transcription Factors ,Research Article - Abstract
Previous work in transfected cell lines and in nuclear extracts has led to the identification of two cis-acting elements important for transcription of the human alpha-1-antitrypsin (A1AT) gene, which bind to two liver specific trans-acting factors, LF-A1 and LF-B1. Mutations EM3 and PM1, which abolish the binding of LF-A1 and LF-B1 respectively, drastically reduce transcription activity of the A1AT gene in vitro and in cell culture. The same mutants have now been introduced in a larger DNA context and their effect has been tested in transgenic mice. A stretch of DNA was constructed which carries two transcriptional units: 18 kb of the human retinol binding protein (RBP) gene, driving the expression of the bacterial chloramphenicol acetyl transferase, linked to 17.5 kb containing the entire A1AT coding sequence with additional 5' and 3' flanking sequences. Transcription from the RBP promoter was shown to predominate in liver, and could be used as an internal marker of 'active copy number'. Mutations in the A1AT gene promoter were introduced by homologous recombination in bacterial cells. The results show that base pair substitutions in the binding site for LF-A1 and LF-B1 drastically reduce transcription in non-hepatic adult tissues, yolk sac, and fetal liver, whereas only LF-B1 binding site mutations have a marked, albeit variable, effect in adult liver.
- Published
- 1991
157. Met murine hepatocytes: A new model for the study of liver cholesterol metabolism
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K.M. Botham, E. Bravo, Marco Tripodi, L. Amicone, and Claudio Cavallari
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medicine.medical_specialty ,Liver cholesterol ,Endocrinology ,Chemistry ,Internal medicine ,medicine ,Metabolism ,Cardiology and Cardiovascular Medicine ,Liver X receptor - Published
- 1999
158. 174 Opposite effects of immortalized met murine hepatocytes on cell cycle and cell fate of rat liver hepatic stellate cells and liver myofibroblasts
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A. Elmaouhoub, R. Novosiadlyy, V. Bordoni, Marco Tripodi, Jozsef Dudas, I. Aprighano, Giuliano Ramadori, and Bernhard Saile
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Hepatology ,Chemistry ,Liver cytology ,Rat liver ,Hepatic stellate cell ,Cell cycle ,Cell fate determination ,Myofibroblast ,Cell biology - Published
- 2006
159. [Untitled]
- Author
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Paolo Vezzoni, Laura Amicone, Marco Tripodi, Daniela Filippini, Maria Grazia Sacco, and Enrica Mira Catò
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Reporter gene ,Sodium arsenite ,Transgene ,Biology ,Molecular biology ,Hsp70 ,Transgenic Model ,Cell biology ,chemistry.chemical_compound ,medicine.anatomical_structure ,chemistry ,Cell culture ,Hepatocyte ,Heat shock protein ,medicine ,Biotechnology - Abstract
Primary hepatocytes, one of the most widely used cell types for toxicological studies, have a very limited life span and must be freshly derived from mice or even humans. Attempts to use stable cell lines maintaining the enzymatic pattern of liver cells have been so far unsatisfactory. Stress proteins (heat shock proteins, HSPs) have been proposed as general markers of cellular injury and their use for environmental monitoring has been suggested. The aim of this work is to develop a bi-transgenic hepatocyte cell line in order to evaluate the ability of various organic and inorganic chemicals to induce the expression of the HSP70 driven reporter gene. We previously described transgenic mice (Hsp70/hGH) secreting high levels of human Growth Hormone (hGH) following exposure to toxic compounds in vivo and in vitro in primary cultures derived from different organs. In addition, we also reported another transgenic model (AT/cytoMet) allowing the reproducible immortalization of untransformed hepatocytes retaining in vitro complex liver functions. The transgenic mouse line Hsp70/hGH was crossed with the AT/cytoMet transgenic strain permitting the reproducible immortalization of untransformed hepatocytes. From double transgenic animals we derived several stable hepatic cell lines (MMH-GH) which showed a highly-differentiated phenotype as judged from the retention of epithelial cell polarity and the profile of gene expression, including hepatocyte-enriched transcription factors and detoxifying enzymes. In these cell lines, stresses induced by exposure to inorganic [Sodium Arsenite (NaAsO2) and Cadmium Chloride (CdCl2)], and organic [Benzo(a)Pyrene (BaP), PentaChloroPhenol (PCP), TetraChloroHydroQuinone (TCHQ), 1-Chloro-2,4-DiNitro-Benzene (CDNB)] compounds, specifically induced hGH release in the culture medium. MMH-GH, an innovative model to evaluate the toxic potential of chemical and physical xenobiotics, provides a simple biological system that may reduce the need for animal experimentation and/or continuously deriving fresh hepatocytes.
- Published
- 2004
160. Overexpression of the hepatitis B virus X gene in liver cells is associated with apoptosis
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Marie-Annick Buendia, Marco Tripodi, Teresa Pollicino, Pierre Tiollais, H. Lecoeur, Olivier Terradillos, and M.-L. Gougeon
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Hepatology ,Apoptosis ,Hepatitis B virus DNA polymerase ,Viral transformation ,Hepatitis B Virus-X ,Biology ,Gene ,Virology - Published
- 1998
161. Very low density lipoprotein and low density lipoprotein isolated from patients with hepatitis C infection induce altered cellular lipid metabolism.
- Author
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Mariarosaria Napolitano, Alessandro Giuliani, Tonino Alonzi, Carmine Mancone, Gianpiero D'Offizi, Marco Tripodi, and Elena Bravo
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LOW density lipoproteins ,HEPATITIS C ,HEPATITIS ,LIPID metabolism - Abstract
Several abnormalities of lipid metabolism, including hypo‐β‐lipoproteinemia and liver steatosis are associated with infection by hepatitis C virus (HCV). The aim of this study was to determine whether circulating lipoproteins of patients with HCV infection could directly cause alterations of lipid cellular metabolism. To this end the metabolic response of human monocyte‐derived macrophages (HMDM) to very low‐density lipoprotein (VLDL) and low‐density lipoprotein (LDL), measuring the cholesteryl ester (CE) and triglyceride (TG) production was analyzed. Lipoproteins were isolated from 18 patients infected with hepatitis C virus (HCV‐VLDL and HCV‐LDL) and from normal healthy donors (ct‐VLDL and ct‐LDL). In comparison to ct‐lipoproteins, HCV‐lipoproteins induced significant differences in HMDM CE and TG production. HCV‐VLDL decreased CE and TG production; while HCV‐LDL induced an increased TG synthesis. The present findings suggest that HCV infection modifies VLDL and LDL molecular composition, affecting cellular lipid metabolism, thus promoting intracellular lipid accumulation and hypo‐β‐lipoproteinemia. J. Med. Virol. 79:254–258, 2007. © 2007 Wiley‐Liss, Inc. [ABSTRACT FROM AUTHOR]
- Published
- 2007
162. Proteomic analysis of human very low-density lipoprotein by two-dimensional gel electrophoresis and MALDI-TOF/TOF.
- Author
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Carmine Mancone, Laura Amicone, Gian Maria Fimia, Elena Bravo, Mauro Piacentini, Marco Tripodi, and Tonino Alonzi
- Published
- 2007
- Full Text
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163. Animal model for human liver disease: transgenic mice carrying viral and pathogenic genes
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Laura Amicone, Laura Pozzi, Marco Tripodi, Sabina Perfumo, Stefano Colloca, and Carlo Delia Rocca
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Pharmacology ,Genetically modified mouse ,Animal model ,Human liver ,Disease ,Biology ,Virology ,Pathogenic genes - Published
- 1990
164. The human alpha-1-antitrypsin gene is efficiently expressed from two tissue-specific promotors in transgenic mice
- Author
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Ulrich Rüther, Riccardo Cortcsc, Erwin F. Wagner, and Marco Tripodi
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Genetically modified mouse ,Mutant ,DNA, Recombinant ,Mice, Transgenic ,Biology ,Kidney ,law.invention ,Mice ,law ,Transcription (biology) ,Gene expression ,Genetics ,Animals ,Humans ,Promoter Regions, Genetic ,Gene ,Regulation of gene expression ,Macrophages ,Promoter ,Molecular biology ,Recombinant Proteins ,Mice, Inbred C57BL ,Gene Expression Regulation ,Liver ,Organ Specificity ,alpha 1-Antitrypsin ,Recombinant DNA ,Female - Abstract
Alpha 1-antitrypsin (alpha 1AT) present in large amounts in human serum and synthesized predominantly in hepatocytes, is the most abundant protease inhibitor and alpha 1AT mutant proteins are associated with hereditary disorders. To investigate the regulation of the normal human alpha 1AT gene, we have microinjected fertilized mouse eggs with a 17.5 kb DNA fragment containing the entire gene with 7 kb 5' and 0.3 kb 3' flanking sequences. We show that this DNA fragment contains all the information for efficient, accurate and tissue-specific expression. High serum concentration of the human protein was found in three independent transgenic mouse lines. The human alpha 1AT RNA is transcribed efficiently in liver, kidney and macrophages and we demonstrate that two different promoters are used for the expression in liver and macrophages of the transgenic mice.
- Published
- 1987
165. DNA sequences complementary to human 7 SK RNA show structural similarities to the short mobile elements of the mammalian genome
- Author
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Elisabetta Ullu, Shona Murphy, L. Silengo, Marialuisa Melli, F. Altruda, and Marco Tripodi
- Subjects
Recombination, Genetic ,Genetics ,Base Sequence ,Genotype ,Pseudogene ,Nucleic Acid Hybridization ,DNA ,Biology ,DNA sequencing ,chemistry.chemical_compound ,Nucleic acid thermodynamics ,Genes ,chemistry ,Structural Biology ,Humans ,Direct repeat ,Electrophoresis, Polyacrylamide Gel ,Human genome ,Cloning, Molecular ,Molecular Biology ,Gene ,HeLa Cells ,Genomic organization - Abstract
A complementary DNA clone of 7 SK RNA from HeLa cells was used to study the genomic organization of 7 SK sequences in the human genome. Genomic hybridizations and genomic clones show that 7 SK is homologous to a family of disperse repeated sequences most of which lack the 3' end of the 7 SK RNA sequence. Only few of the genomic K sequences are homologous to both 3' and 5' 7 SK probes and presumably include the gene(s) for 7 SK RNA. The sequence of four genomic 7 SK clones confirms that they are in most cases pseudogenes. Although Alu sequences are frequently found near the 3' and 5' end of K DNA, the sequences immediately flanking the pseudogenes are different in all clones studied. However, direct repeats were found flanking directly the K DNA or the K-Alu unit, suggesting that the K sequences alone or in conjunction with Alu DNA might constitute a mobile element.
- Published
- 1984
166. Human leukemia K-562 cells: induction of erythroid differentiation by 5-azacytidine
- Author
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Antonio Fantoni, Giuseppe Raschellà, Laura del Senno, Marco Tripodi, Roberto Gambari, Raffaella Barbieri, and Viola L
- Subjects
Erythrocytes ,HpaII ,Hemoglobins, Abnormal ,Cellular differentiation ,dna methylation ,Biology ,Methylation ,Deoxyribonuclease HpaII ,Cell Line ,Hemoglobins ,chemistry.chemical_compound ,5-azacytidine ,hemic and lymphatic diseases ,Humans ,RNA, Messenger ,Globin ,Fetal Hemoglobin ,erythroid differentiation ,globin mrna ,k-562 cell ,Cell Differentiation ,DNA ,DNA Restriction Enzymes ,Molecular biology ,Globins ,Restriction enzyme ,Gene Expression Regulation ,chemistry ,Cell culture ,DNA methylation ,Azacitidine ,Leukemia, Erythroblastic, Acute ,Developmental Biology - Abstract
In this article we show that the cytidine analog 5-azacytidine is able to induce differentiation of the human leukemia K-562 cell line. Erythroid induction is associated with (a) an increase of the overall globin synthesis and globin mRNA accumulation, (b) a relative increase of fetal with respect to embryonic globins, and (c) a decrease of the proliferative capacity of hemoglobin-containing cells. In addition, we have analysed the DNA methylation pattern at the cleavage sites of MspI and HpaII restriction enzymes, which are known to cleave differently CCGG DNA sequences when 5-methylcytosine is present. These experiments indicate that in K-562 cells treated with 5-azacytidine, DNA becomes hypomethylated, suggesting that genetic programmes leading to an erythroid phenotype may be activated by a reduction of DNA methylation.
- Published
- 1984
167. Ultrafast tissue staining with chemical tags
- Author
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Ernesto Ciabatti, Marco Tripodi, Sebastian Cachero, Ben Sutcliffe, Daniel Krueger, Gregory S.X.E. Jefferis, Julian Ng, Tiago Branco, Adam Tozer, Shahar Frechter, Johannes Kohl, Sabine Ruehle, and Michael-John Dolan
- Subjects
Neurons ,0303 health sciences ,Multidisciplinary ,Staining and Labeling ,Transgene ,Brain ,Biology ,Molecular biology ,Cell biology ,Staining ,Viral vector ,Mice, Inbred C57BL ,03 medical and health sciences ,0302 clinical medicine ,PNAS Plus ,Fluorescence microscope ,Animals ,Immunohistochemistry ,Drosophila ,Tissue staining ,030217 neurology & neurosurgery ,Chemical labeling ,Immunostaining ,Fluorescent Dyes ,030304 developmental biology - Abstract
Genetically encoded fluorescent proteins and immunostaining are widely used to detect cellular and subcellular structures in fixed biological samples. However, for thick or whole-mount tissue, each approach suffers from limitations, including limited spectral flexibility and lower signal or slow speed, poor penetration, and high background labeling, respectively. We have overcome these limitations by using transgenically expressed chemical tags for rapid, even, high-signal and low-background labeling of thick biological tissues. We first construct a platform of widely applicable transgenic Drosophila reporter lines, demonstrating that chemical labeling can accelerate staining of whole-mount fly brains by a factor of 100. Using viral vectors to deliver chemical tags into the mouse brain, we then demonstrate that this labeling strategy works well in mice. Thus this tag-based approach drastically improves the speed and specificity of labeling genetically marked cells in intact and/or thick biological samples.
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- View/download PDF
168. Desferrioxamine inhibits induced erythroid differentiation of human leukemic K-562 cells
- Author
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Marco Tripodi, Maria Giulia Farace, Roberto Gambari, Antonio Fantoni, and Giuseppe Raschellà
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k-562 cells ,Erythrocytes ,Erythroblasts ,Cellular differentiation ,Iron ,Heme ,Biology ,Deferoxamine ,chemistry.chemical_compound ,Transcription (biology) ,hemic and lymphatic diseases ,medicine ,Humans ,Inducer ,Globin ,Gene ,erythroid differentiation ,Regulation of gene expression ,desferrioxamine ,Leukemia ,Cell Differentiation ,Molecular biology ,Globins ,Butyrates ,chemistry ,Gene Expression Regulation ,Butyric Acid ,Cell Division ,Developmental Biology ,medicine.drug - Abstract
The iron chelator desferrioxamine reversibly inhibits heme accumulation and globin synthesis in human leukemic K-562 cells induced to express erythroid genes by butyric acid. These results suggest that iron metabolism can modulate globin gene expression. In addition we describe experimental conditions (6.25 micrograms/ml desferrioxamine) which do not suppress transcription of globin genes and translation of globin mRNA but prevent heme synthesis. Therefore expression of globin genes in butyric acid induced K-562 cells does not require accumulation of heme molecules. Human leukemic K-562 cells cultured with different inducers and treated with desferrioxamine should be used as a useful model system to further analyse the relationship between expression of erythroid genes, iron metabolism and heme accumulation.
- Published
- 1983
169. Assignment of human coagulation factor XII (fXII) to chromosome 5 by cDNA hybridization to DNA from somatic cell hybrids
- Author
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Giovanni Romeo, Marco Tripodi, Mariano Rocchi, Francesco Bernardi, Franca Citarella, and Antonio Fantoni
- Subjects
Coagulation Factor XII ,Hybrid Cells ,Restriction fragment ,chemistry.chemical_compound ,Cricetulus ,Complementary DNA ,Cricetinae ,Genetics ,Animals ,Humans ,Gene ,Genetics (clinical) ,Serine protease ,Factor XII ,biology ,Chromosome Mapping ,Nucleic Acid Hybridization ,DNA ,Molecular biology ,Restriction enzyme ,Blotting, Southern ,Biochemistry ,chemistry ,biology.protein ,Chromosomes, Human, Pair 5 - Abstract
Human coagulation factor XII (fXII), a serine protease synthesized in liver and active in plasma, is involved in a wide variety of functions, including blood coagulation, fibrinolysis, bradykinin and complement activation. A complementary DNA (597 bp) encoding amino acid -16 to amino acid 183 of fXII protein was used to determine the chromosomal location of the fXII gene. DNAs from hamster-human somatic cell hybrids were digested with restriction enzymes and hybridized with the fXII cDNA. By the Southern method it was shown that restriction fragments able to hybridize to fXII cDNA are present only in DNA extracted from clones retaining human chromosome 5.
- Published
- 1988
170. Molecular cloning and sequence analysis of a cDNA coding for the mouse alpha-like embryonic globin chain x
- Author
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Marshall H. Edgell, Marco Tripodi, Alison Presmanes Hill, Roberto Gambari, Giuseppe Raschellà, Maria Giulia Farace, Antonio Fantoni, Clyde A. Hutchison, and Richard W. Padgett
- Subjects
Untranslated region ,Sequence analysis ,DNA, Recombinant ,Molecular cloning ,Biology ,Mice ,Species Specificity ,Complementary DNA ,Genetics ,Animals ,Humans ,Amino Acid Sequence ,RNA, Messenger ,Globin ,Gene ,Fetal Hemoglobin ,Phylogeny ,Base Sequence ,cDNA library ,Nucleic acid sequence ,General Medicine ,Molecular biology ,Globins ,Protein Biosynthesis ,Chickens - Abstract
Cytoplasmic poly(A)+mRNA from 12-day mouse-yolk-sac erythroid cells has been used to prepare a cDNA library in the plasmid pBR322. One clone containing sequences coding for the alpha-like embryonic globin chain x, pHE52, has been identified by hybrid selection and in vitro translation of the complementary mRNA. The nucleotide sequence of pHE52 confirms that it codes for an embryonic alpha-like globin chain. The insert sequence is 316 nucleotides long, contains the codons corresponding to amino acid residues 43-141, and extends into the 3' untranslated region. An analysis of the nucleotide sequence of pHE52 and the other known alpha globins suggests that the adult-embryonic divergence began approx. 400 million years ago reflecting a difference in the evolutionary history of the alpha- and beta-globin gene complexes.
- Published
- 1984
171. A SEQUENCE UPSTREAM FROM THE CODING REGION IS REQUIRED FOR THE TRANSCRIPTION OF THE 7SK RNA GENES
- Author
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Marialuisa Melli, Marco Tripodi, and Shona Murphy
- Subjects
Genetics ,Base Sequence ,Transcription, Genetic ,biology ,DNA, Recombinant ,Intron ,Nucleic Acid Hybridization ,RNA Polymerase III ,RNA ,RNA-dependent RNA polymerase ,RNA polymerase II ,Ribonucleoproteins, Small Nuclear ,Molecular biology ,Ribonucleoproteins ,Transcription (biology) ,Sequence Homology, Nucleic Acid ,biology.protein ,Humans ,Transcription factor II D ,Promoter Regions, Genetic ,RNA polymerase II holoenzyme ,Small nuclear RNA ,Repetitive Sequences, Nucleic Acid - Abstract
We have isolated and characterized two recombinant lambda phages containing sequences homologous to 7SK RNA which code for a RNA 330 nucleotides long in an "in vitro" transcription system. S1 mapping of the transcript shows that this RNA corresponds to the 7SK RNA obtained from human cells, indicating that the two recombinant phages contain genes coding for 7SK RNA. The transcription of these genes is polymerase III dependent. Sequences upstream from the start of transcription are essential for "in vitro" synthesis of 7SK RNA, suggesting that internal promoter elements, if present, are not sufficient to support the synthesis of 7SK RNA. A region of homology with the upstream sequences of the genes for U6 RNA, 7SL RNA and Bombyx mori alanine tRNA is found within 50 bp from the transcription start point. Within the homologous region a motif common to the four genes is a "TATA"-like box, placed at position -30 to -25 of the 7SK RNA gene, which is typical of the polymerase II promoter region.
- Published
- 1986
172. Expression of human alpha 1-acid glycoprotein genes in cultured cells and in transgenic mice
- Author
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Luciana Dente, U. Rüther, Marco Tripodi, Ef Wagner, and Riccardo Cortese
- Subjects
Genetically modified mouse ,Regulation of gene expression ,Messenger RNA ,Transcription, Genetic ,Mice, Transgenic ,Transfection ,Orosomucoid ,Biology ,Molecular biology ,Cell Line ,Mice ,Gene Expression Regulation ,Liver ,Cell culture ,Multigene Family ,Gene expression ,Genetics ,Coding region ,Animals ,Humans ,Cloning, Molecular ,Gene ,Developmental Biology - Abstract
The human genome contains three alpha 1-glycoprotein genes (AGP-A, AGP-B, and AGP-B') encoding for slightly different forms of the protein. The major component of human alpha 1-acid glycoprotein found in plasma is coded by AGP-A, which is expressed in liver and in hepatoma cell lines and is induced by inflammatory stimuli. We have studied the regulation of the cloned AGP-A gene by transfection into cell lines of hepatic and nonhepatic origin. Unlike any other liver-specific gene investigated so far, every AGP construct tested was expressed with comparable efficiency in hepatoma and HeLa cells. In contrast, identical constructs in transgenic mice are expressed in a tissue-specific manner and are regulated by acute-phase stimuli. Transgenic mice carrying the cluster of three AGP genes secrete the human protein in the serum, and the corresponding mRNA is mainly derived from the AGP-A gene. The mRNA is liver specific, and its concentration increases several fold following experimentally induced inflammation. Additional transgenic lines carrying only the AGP-A gene showed that sufficient information for tissue-specific and regulated expression is contained within a 6.6-kb segment comprising the whole coding region plus 1.2-kb 5'-flanking and 2-kb 3'-flanking DNA.
- Published
- 1988
173. cDNA sequence coding for human coagulation factor XII (Hageman)
- Author
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Riccardo Cortese, Marco Tripodi, S. Guida, Franca Citarella, P. Galeffi, and Antonio Fantoni
- Subjects
Genetics ,Factor XII ,Base Sequence ,Protein primary structure ,Coagulation Factor XII ,DNA ,Biology ,Molecular biology ,chemistry.chemical_compound ,chemistry ,Liver ,Complementary DNA ,Humans ,Amino Acid Sequence ,Peptide sequence ,Factor hageman ,Sequence (medicine) - Published
- 1986
174. Human leukemia K562 cells: relationship between hemin-mediated erythroid induction, cell proliferation and expression of c-abl and c-myc oncogenes
- Author
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Antonio Fantoni, Roberta Piva, Laura del Senno, Franca Citarella, Francesco Bernardi, Marco Tripodi, Roberto Gambari, Giovanna Marchetti, Amelotti F, and Raffaella Barbieri
- Subjects
Erythrocytes ,Cell division ,Biophysics ,Heme ,Biology ,Biochemistry ,Cell Line ,Hemoglobins ,hemic and lymphatic diseases ,medicine ,Humans ,RNA, Messenger ,Molecular Biology ,Regulation of gene expression ,ABL ,Leukemia ,Oncogene ,Cell growth ,Nucleic Acid Hybridization ,Cell Biology ,Oncogenes ,medicine.disease ,Molecular biology ,Cell biology ,Cell Transformation, Neoplastic ,Gene Expression Regulation ,Cell culture ,Hemin ,Cell Division ,K562 cells - Abstract
We have studied the expression of the c-myc and c-abl oncogenes in two human leukemic K562 cell lines which do express hemoglobin genes retaining a differential rate of cell proliferation. Our data indicate that in hemin-induced K562(S) cells the expression of c-abl oncogene decreases and appears to be related to a decrease in the proliferation capacity rather than to the activation of differentiated functions. The K562(hC) cell line, which produces large amounts of Hb Gower 1 retaining an efficient rate of cell proliferation, expresses indeed the c-abl oncogene at high level.
- Published
- 1984
175. Activated Vγ9Vδ2 T cells trigger granulocyte functions via MCP-2 release
- Author
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Chiara Agrati, Federico Martini, Veronica Bordoni, Alessandra Sacchi, Marco Tripodi, Rita Casetti, Cristiana Gioia, Eleonora Cimini, Federica Turchi, Agrati, C., Cimini, E., Sacchi, A., Bordoni, V., Gioia, C., Casetti, R., Turchi, F., Tripodi, M., and Martini, F.
- Subjects
Granulocyte activation ,T cell ,Immunology ,Lymphokine ,Biology ,Acquired immune system ,Cell biology ,Interleukin 21 ,medicine.anatomical_structure ,Immune system ,medicine ,Immunology and Allergy ,Cytotoxic T cell ,Interleukin 3 - Abstract
Vγ9Vδ2 T cells display a broad antimicrobial activity by directly killing infected cells and by inducing an effective adaptive immune response. The activation of Vγ9Vδ2 T cells by aminobisphosphonate drugs such as zoledronic acid (ZOL) results in a massive release of cytokines and chemokines that may induce a bystander activation of other immune cells. The aim of this work was to evaluate the ability of soluble factors released by ZOL-activated Vγ9Vδ2 T cells to induce granulocyte activation. We showed that soluble factors released by ZOL-stimulated Vγ9Vδ2 T cells activate granulocytes by inducing their chemotaxis, phagocytosis, and α-defensins release. Proteomic analysis allowed us to identify a number of cytokines and chemokines specifically released by activated Vγ9Vδ2 T cells. Moreover, MCP-2 depletion by neutralizing Ab revealed a critical role of this chemokine in induction of granulocyte α-defensins release. Altogether, these data show a Vγ9Vδ2-mediated activation of granulocytes through a bystander mechanism, and confirm the wide ability of Vγ9Vδ2 T-lymphocytes in orchestrating the immune response. In conclusion, an immune modulating strategy targeting Vγ9Vδ2 T cells may represent a key switch to induce an effective and well-coordinated immune response, and can be proposed as a way to strengthen the immune competence during infectious diseases. Copyright © 2008 by The American Association of Immunologists, Inc.
176. Generation of small mutation in large genomic fragments by homologous recombination: Description of the technique and examples of its use
- Author
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Robin R. Ali, Riccardo Cortese, Marco Tripodi, Catherine M. Abbott, Sabina Perfumo, and Laura Amicone
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Cloning ,Genetics ,clone (Java method) ,Recombination, Genetic ,Mutagenesis (molecular biology technique) ,Gene Expression ,Exons ,Biology ,Cosmids ,Plasmid ,Genetic Techniques ,Mutagenesis ,Mutation (genetic algorithm) ,Cosmid ,Escherichia coli ,Cloning, Molecular ,Homologous recombination ,Recombination ,Plasmids - Abstract
We have developed a technique of homologous recombination in bacteria which allows the mutagenesis of large genomic fragments cloned in cosmids. The desired mutation is first introduced into a plasmid clone and is then transferred to the appropriate cosmid clone by the means of double antibiotic selection coupled with phenotypic selection. We describe three different types of construct made by this technique.
177. ADAR1 restricts LINE-1 retrotransposition
- Author
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Ambra Antonioni, Loredana Frassinelli, Silvia Galardi, Marco Tripodi, Alessandro Michienzi, Margherita Doria, Silvia Anna Ciafrè, Claudia Montaldo, Carmine Mancone, and Elisa Orecchini
- Subjects
0301 basic medicine ,Retroelements ,Adenosine Deaminase ,Retrotransposon ,Biology ,Ribosome ,03 medical and health sciences ,retrotransposition ,ADAR1 ,Genetics ,Humans ,Heat-Shock Proteins ,Ribonucleoprotein ,Regulation of gene expression ,Gene Expression Profiling ,editing ,Gene regulation, Chromatin and Epigenetics ,Settore BIO/13 ,RNA ,RNA-Binding Proteins ,Molecular Sequence Annotation ,LINE1 ,Molecular biology ,Cell biology ,Long interspersed nuclear element ,030104 developmental biology ,HEK293 Cells ,Long Interspersed Nucleotide Elements ,Viral replication ,Gene Expression Regulation ,Ribonucleoproteins ,RNA editing ,Host-Pathogen Interactions ,HIV-1 ,Genetics. ADAR ,Biological Assay ,HeLa Cells ,Protein Binding ,Signal Transduction - Abstract
Adenosine deaminases acting on RNA (ADARs) are involved in RNA editing that converts adenosines to inosines in double-stranded RNAs. ADAR1 was demonstrated to be functional on different viruses exerting either antiviral or proviral effects. Concerning HIV-1, several studies showed that ADAR1 favors viral replication. The aim of this study was to investigate the composition of the ADAR1 ribonucleoprotein complex during HIV-1 expression. By using a dual-tag affinity purification procedure in cells expressing HIV-1 followed by mass spectrometry analysis, we identified 14 non-ribosomal ADAR1-interacting proteins, most of which are novel. A significant fraction of these proteins were previously demonstrated to be associated to the Long INterspersed Element 1 (LINE1 or L1) ribonucleoparticles and to regulate the life cycle of L1 retrotransposons that continuously re-enter host-genome. Hence, we investigated the function of ADAR1 in the regulation of L1 activity. By using different cell-culture based retrotransposition assays in HeLa cells, we demonstrated a novel function of ADAR1 as suppressor of L1 retrotransposition. Apparently, this inhibitory mechanism does not occur through ADAR1 editing activity. Furthermore, we showed that ADAR1 binds the basal L1 RNP complex. Overall, these data support the role of ADAR1 as regulator of L1 life cycle.
178. Biotin-tagged cDNA expression libraries displayed on lambda phage: a new tool for the selection of natural protein ligands
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Alessandra Luzzago, Carla Cicchini, Helenia Ansuini, Riccardo Cortese, Marco Tripodi, Alfredo Nicosia, H., Ansuini, C., Cicchini, Nicosia, Alfredo, M., Tripodi, R., Cortese, and A., Luzzago
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DNA, Complementary ,Phage display ,Genetic Vectors ,Molecular Sequence Data ,Reading frame ,GAP-43 ,Biotin ,Gene Expression ,VECTOR ,Computational biology ,Biology ,Ligands ,Chromatography, Affinity ,Cell Line ,Mice ,Open Reading Frames ,Viral Proteins ,GAP-43 Protein ,Peptide Library ,Complementary DNA ,BINDING ,Tumor Cells, Cultured ,Genetics ,Animals ,Humans ,Amino Acid Sequence ,NAR Methods Online ,Base Sequence ,SEQUENCES ,cDNA library ,ANTIBODY-ANTIGEN INTERACTIONS ,Antibodies, Monoclonal ,Brain ,BACTERIOPHAGE-LAMBDA ,Genomics ,Lambda phage ,biology.organism_classification ,Bacteriophage lambda ,GENE ,Open reading frame ,SURFACE DISPLAY ,Biotinylation ,BIOTINYLATION ,Capsid Proteins ,RANDOM PEPTIDE LIBRARIES ,Streptavidin ,Functional genomics - Abstract
cDNA expression libraries displayed on lambda phage have been successfully employed to identify partners involved in antibody–antigen, protein– protein and DNA–protein interactions and represent a novel approach to functional genomics. However, as in all other cDNA expression libraries based on fusion to a carrier polypeptide, a major issue of this system is the absence of control over the translation frame of the cDNA. As a consequence, a large number of clones will contain lambda D/cDNA fusions, resulting in the foreign sequence being translated on alternative reading frames. Thus, many phage will not display natural proteins, but could be selected, as they mimic the binding properties of the real ligand, and will hence interfere with the selection outcome. Here we describe a novel lambda vector for display of exogenous peptides at the C-terminus of the capsid D protein. In this vector, translation of fusion peptides in the correct reading frame allows efficient in vivo biotinylation of the chimeric phage during amplification. Using this vector system we constructed three libraries from human hepatoma cells, mouse hepatocytic MMH cells and from human brain. Clones containing open reading frames (ORFs) were rapidly selected by streptavidin affinity chromatography, leading to biological repertoires highly enriched in natural polypeptides. We compared the selection outcome of two independent experiments performed using an anti-GAP-43 monoclonal antibody on the human brain cDNA library before and after ORF enrichment. A significant increase in the efficiency of identification of natural target peptides with very little background of false-positive clones was observed in the latter case.
179. Inhibition of MMH (Met murine hepatocyte) cell differentiation by TGFβ is abrogated by pre-treatment with the heritable differentiation effector FGF1
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Spagnoli, F. M., Cicchini, C., Marco Tripodi, and Weiss, M. C.
180. CD90+ liver cancer cells modulate endothelial cell phenotype through the release of exosomes containing H19 lncRNA
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Mauro Manno, Viviana Costa, Alessia Lo Dico, Samuele Raccosta, Marco Tripodi, Riccardo Alessandro, Carmine Mancone, Francesco Dieli, Giacomo De Leo, Alice Conigliaro, Simona Buccheri, Laura Saieva, Conigliaro, A, Costa, V, Lo Dico, A, Saieva, L, Buccheri, S, Dieli, F, Manno, M, Raccosta, S, Mancone, C, Tripodi, M, De Leo, G, and Alessandro, R
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Cancer Research ,Angiogenesis ,CD90+ liver cancer cells ,Exosomes ,Long-non-coding RNA H19 ,Antigens, Thy-1 ,Cell Adhesion ,Cell Line, Tumor ,Endothelial Cells ,Human Umbilical Vein Endothelial Cells ,Humans ,Liver Neoplasms ,RNA, Long Noncoding ,Phenotype ,Molecular Medicine ,Oncology ,Biology ,Cell Line ,Settore BIO/13 - Biologia Applicata ,Cancer stem cell ,medicine ,CD90 ,Antigens ,Thy-1 ,Tumor ,Exosomes, Long-non-coding RNA H19, CD90+ liver cancer cells, Angiogenesis ,Research ,Cancer ,medicine.disease ,Microvesicles ,Cell biology ,Endothelial stem cell ,embryonic structures ,Thy-1 Antigens ,RNA ,Long Noncoding ,Stem cell ,Liver cancer - Abstract
Background CD90+ liver cancer cells have been described as cancer stem-cell-like (CSC), displaying aggressive and metastatic phenotype. Using two different in vitro models, already described as CD90+ liver cancer stem cells, our aim was to study their interaction with endothelial cells mediated by the release of exosomes. Methods Exosomes were isolated and characterized from both liver CD90+ cells and hepatoma cell lines. Endothelial cells were treated with exosomes, as well as transfected with a plasmid containing the full length sequence of the long non-coding RNA (lncRNA) H19. Molecular and functional analyses were done to characterize the endothelial phenotype after treatments. Results Exosomes released by CD90+ cancer cells, but not by parental hepatoma cells, modulated endothelial cells, promoting angiogenic phenotype and cell-to-cell adhesion. LncRNA profiling revealed that CD90+ cells were enriched in lncRNA H19, and released this through exosomes. Experiments of gain and loss of function of H19 showed that this LncRNA plays an important role in the exosome-mediated phenotype of endothelial cells. Conclusions Our data indicate a new exosome-mediated mechanism by which CSC-like CD90+ cells could influence their tumor microenvironment by promoting angiogenesis. Moreover, we suggest the lncRNA H19 as a putative therapeutic target in hepatocellular carcinoma. Electronic supplementary material The online version of this article (doi:10.1186/s12943-015-0426-x) contains supplementary material, which is available to authorized users.
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181. Predominant expression of σ and ε globin genes in human leukemia K-562(S6) variant cell line
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A. Fantoni, Marco Tripodi, Roberto Gambari, Antonino Romeo, Giuseppe Raschellà, R. Biagini, and Maria Giulia Farace
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Erythroblasts ,Cell division ,Cellular differentiation ,Biology ,Cell Line ,Cellular and Molecular Neuroscience ,hemic and lymphatic diseases ,Gene expression ,medicine ,Humans ,Globin ,Molecular Biology ,Pharmacology ,Regulation of gene expression ,Leukemia ,Cell Cycle ,Cell Differentiation ,Cell Biology ,Cell cycle ,medicine.disease ,Molecular biology ,Globins ,Cell biology ,Gene Expression Regulation ,Cell culture ,Hemin ,Molecular Medicine ,Cell Division - Abstract
In the human leukemia K-562(S6) cell line (a) the accumulation of alpha-globin chains is low or absent, (b) zeta-globin gene expression is correlated with expression of epsilon-chains and (c) the genes responsible for the terminal cell division are not operated within 8-12 cell cycles, while K-562(S6) cells are fully induced to erythroid differentiation.
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- 1983
182. TaqI polymorphism at the human coagulation factor XII locus (F12)
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Giovanna Marchetti, Marco Tripodi, Francesco Bernardi, and F Panicucci
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Genetics ,Factor XII ,Polymorphism, Genetic ,TaqI POLYMORPHISM ,Locus (genetics) ,DNA Restriction Enzymes ,Coagulation Factor XII ,Biology ,Molecular biology ,Restriction fragment ,biology.protein ,Humans ,Factor hageman - Published
- 1986
183. A human liver cDNA recombinant plasmid expressed in bacteria produces a protein immunolocically identical to factor VII of human coagulation
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Marco Tripodi, Laura Amicone, Franca Citarella, P. Galeffi, G. Mariani, Antonio Fantoni, and S. Guida
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Factor VII ,Human liver ,A protein ,Cell Biology ,Biology ,biology.organism_classification ,Molecular biology ,law.invention ,chemistry.chemical_compound ,Coagulation ,chemistry ,law ,Complementary DNA ,Recombinant DNA ,Bacteria - Published
- 1986
184. Hepatitis C virus relies on lipoproteins for its life cycle.
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Grassi G, Di Caprio G, Fimia GM, Ippolito G, Tripodi M, and Alonzi T
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- Animals, Hepatitis C diagnosis, Hepatitis C virology, Host-Pathogen Interactions, Humans, Life Cycle Stages, Liver virology, Signal Transduction, Virion metabolism, Virus Internalization, Virus Replication, Hepacivirus growth & development, Hepacivirus metabolism, Hepatitis C metabolism, Lipoproteins metabolism, Liver metabolism
- Abstract
Hepatitis C virus (HCV) infects over 150 million people worldwide. In most cases, HCV infection becomes chronic causing liver disease ranging from fibrosis to cirrhosis and hepatocellular carcinoma. Viral persistence and pathogenesis are due to the ability of HCV to deregulate specific host processes, mainly lipid metabolism and innate immunity. In particular, HCV exploits the lipoprotein machineries for almost all steps of its life cycle. The aim of this review is to summarize current knowledge concerning the interplay between HCV and lipoprotein metabolism. We discuss the role played by members of lipoproteins in HCV entry, replication and virion production.
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- 2016
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