65 results on '"Natalia Pediconi"'
Search Results
2. Retinal fingerprints of ALS in patients: Ganglion cell apoptosis and TDP-43/p62 misplacement
- Author
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Natalia Pediconi, Ylenia Gigante, Silvia Cama, Martina Pitea, Lorenza Mautone, Giancarlo Ruocco, Silvia Ghirga, and Silvia Di Angelantonio
- Subjects
retina ,ALS ,neurodegeneration ,biomarkers ,protein inclusions ,neurons ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
IntroductionAmyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by the progressive loss of motor neuron function. Although ophthalmic deficits are not considered a classic symptom of ALS, recent studies suggest that changes in retinal cells, similar to those in the spinal cord motor neurons, have been observed in postmortem human tissues and animal models.MethodsIn this study, we examined by immunofluorescence analysis the retinal cell layers of sporadic ALS patients in post-mortem retinal slices. We evaluated the presence of cytoplasmic TDP-43 and SQSTM1/p62 aggregates, activation of the apoptotic pathway, and microglia and astrocytes reactivity.ResultsWe found in the retinal ganglion cell layer of ALS patients the increase of mislocalized TDP-43, SQSTM1/p62 aggregates, activation of cleaved caspase-3, and microglia density, suggesting that retinal changes can be used as an additional diagnostic tool for ALS.DiscussionThe retina is considered part of the central nervous system, and neurodegenerative changes in the brain may be accompanied by structural and possibly functional changes in the neuroretina and ocular vasculature. Therefore, using in vivo retinal biomarkers as an additional diagnostic tool for ALS may provide an opportunity to longitudinally monitor individuals and therapies over time in a noninvasive and cost-effective manner.
- Published
- 2023
- Full Text
- View/download PDF
3. Broadband stimulated Raman imaging based on multi-channel lock-in detection for spectral histopathology
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Alejandro De la Cadena, Federico Vernuccio, Andrea Ragni, Giuseppe Sciortino, Renzo Vanna, Carino Ferrante, Natalia Pediconi, Carlo Valensise, Luca Genchi, Sergey P. Laptenok, Andrea Doni, Marco Erreni, Tullio Scopigno, Carlo Liberale, Giorgio Ferrari, Marco Sampietro, Giulio Cerullo, and Dario Polli
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Applied optics. Photonics ,TA1501-1820 - Abstract
Spontaneous Raman microscopy reveals the chemical composition of a sample in a label-free and non-invasive fashion by directly measuring the vibrational spectra of molecules. However, its extremely low cross section prevents its application to fast imaging. Stimulated Raman scattering (SRS) amplifies the signal by several orders of magnitude thanks to the coherent nature of the nonlinear process, thus unlocking high-speed microscopy applications that provide analytical information to elucidate biochemical mechanisms with subcellular resolution. Nevertheless, in its standard implementation, narrowband SRS provides images at only one frequency at a time, which is not sufficient to distinguish constituents with overlapping Raman bands. Here, we report a broadband SRS microscope equipped with a home-built multichannel lock-in amplifier simultaneously measuring the SRS signal at 32 frequencies with integration time down to 44 µs, allowing for detailed, high spatial resolution mapping of spectrally congested samples. We demonstrate the capability of our microscope to differentiate the chemical constituents of heterogeneous samples by measuring the relative concentrations of different fatty acids in cultured hepatocytes at the single lipid droplet level and by differentiating tumor from peritumoral tissue in a preclinical mouse model of fibrosarcoma.
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- 2022
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- View/download PDF
4. Downregulation of miR‐326 and its host gene β‐arrestin1 induces pro‐survival activity of E2F1 and promotes medulloblastoma growth
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Evelina Miele, Agnese Po, Angela Mastronuzzi, Andrea Carai, Zein Mersini Besharat, Natalia Pediconi, Luana Abballe, Giuseppina Catanzaro, Claudia Sabato, Enrico De Smaele, Gianluca Canettieri, Lucia Di Marcotullio, Alessandra Vacca, Antonello Mai, Massimo Levrero, Stefan M. Pfister, Marcel Kool, Felice Giangaspero, Franco Locatelli, and Elisabetta Ferretti
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ARRB1 ,E2F1 ,EZH2 ,medulloblastoma ,miR‐326 ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Persistent mortality rates of medulloblastoma (MB) and severe side effects of the current therapies require the definition of the molecular mechanisms that contribute to tumor progression. Using cultured MB cancer stem cells and xenograft tumors generated in mice, we show that low expression of miR‐326 and its host gene β‐arrestin1 (ARRB1) promotes tumor growth enhancing the E2F1 pro‐survival function. Our models revealed that miR‐326 and ARRB1 are controlled by a bivalent domain, since the H3K27me3 repressive mark is found at their regulatory region together with the activation‐associated H3K4me3 mark. High levels of EZH2, a feature of MB, are responsible for the presence of H3K27me3. Ectopic expression of miR‐326 and ARRB1 provides hints into how their low levels regulate E2F1 activity. MiR‐326 targets E2F1 mRNA, thereby reducing its protein levels; ARRB1, triggering E2F1 acetylation, reverses its function into pro‐apoptotic activity. Similar to miR‐326 and ARRB1 overexpression, we also show that EZH2 inhibition restores miR‐326/ARRB1 expression, limiting E2F1 pro‐proliferative activity. Our results reveal a new regulatory molecular axis critical for MB progression.
- Published
- 2021
- Full Text
- View/download PDF
5. Molecular Imaging of Tau Protein: New Insights and Future Directions
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Rocco Pizzarelli, Natalia Pediconi, and Silvia Di Angelantonio
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tau ,super-resolution imaging ,neurodegeneration ,BODIPY ,near-infrared fluorescent probes ,Alzheimer’s disease ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
Tau is a microtubule-associated protein (MAPT) that is highly expressed in neurons and implicated in several cellular processes. Tau misfolding and self-aggregation give rise to proteinaceous deposits known as neuro-fibrillary tangles. Tau tangles play a key role in the genesis of a group of diseases commonly referred to as tauopathies; notably, these aggregates start to form decades before any clinical symptoms manifest. Advanced imaging methodologies have clarified important structural and functional aspects of tau and could have a role as diagnostic tools in clinical research. In the present review, recent progresses in tau imaging will be discussed. We will focus mainly on super-resolution imaging methods and the development of near-infrared fluorescent probes.
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- 2020
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6. Antibiotics Treatment Modulates Microglia–Synapses Interaction
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Federica Cordella, Caterina Sanchini, Maria Rosito, Laura Ferrucci, Natalia Pediconi, Barbara Cortese, Francesca Guerrieri, Giuseppe Rubens Pascucci, Fabrizio Antonangeli, Giovanna Peruzzi, Maria Giubettini, Bernadette Basilico, Francesca Pagani, Alfonso Grimaldi, Giuseppina D’Alessandro, Cristina Limatola, Davide Ragozzino, and Silvia Di Angelantonio
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microglia ,gut–brain axis ,antibiotics ,glutamatergic synapses ,hippocampus ,patch clamp ,Cytology ,QH573-671 - Abstract
‘Dysbiosis’ of the adult gut microbiota, in response to challenges such as infection, altered diet, stress, and antibiotics treatment has been recently linked to pathological alteration of brain function and behavior. Moreover, gut microbiota composition constantly controls microglia maturation, as revealed by morphological observations and gene expression analysis. However, it is unclear whether microglia functional properties and crosstalk with neurons, known to shape and modulate synaptic development and function, are influenced by the gut microbiota. Here, we investigated how antibiotic-mediated alteration of the gut microbiota influences microglial and neuronal functions in adult mice hippocampus. Hippocampal microglia from adult mice treated with oral antibiotics exhibited increased microglia density, altered basal patrolling activity, and impaired process rearrangement in response to damage. Patch clamp recordings at CA3-CA1 synapses revealed that antibiotics treatment alters neuronal functions, reducing spontaneous postsynaptic glutamatergic currents and decreasing synaptic connectivity, without reducing dendritic spines density. Antibiotics treatment was unable to modulate synaptic function in CX3CR1-deficient mice, pointing to an involvement of microglia–neuron crosstalk through the CX3CL1/CX3CR1 axis in the effect of dysbiosis on neuronal functions. Together, our findings show that antibiotic alteration of gut microbiota impairs synaptic efficacy, suggesting that CX3CL1/CX3CR1 signaling supporting microglia is a major player in in the gut–brain axis, and in particular in the gut microbiota-to-neuron communication pathway.
- Published
- 2021
- Full Text
- View/download PDF
7. Neuroinflammatory Processes, A1 Astrocyte Activation and Protein Aggregation in the Retina of Alzheimer’s Disease Patients, Possible Biomarkers for Early Diagnosis
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Alfonso Grimaldi, Natalia Pediconi, Francesca Oieni, Rocco Pizzarelli, Maria Rosito, Maria Giubettini, Tiziana Santini, Cristina Limatola, Giancarlo Ruocco, Davide Ragozzino, and Silvia Di Angelantonio
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Alzheimer’s disease ,microglia ,astrocytes ,retina ,beta-amyloid ,tau ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
Alzheimer’s disease (AD), a primary cause of dementia in the aging population, is characterized by extracellular amyloid-beta peptides aggregation, intracellular deposits of hyperphosphorylated tau, neurodegeneration and glial activation in the brain. It is commonly thought that the lack of early diagnostic criteria is among the main causes of pharmacological therapy and clinical trials failure; therefore, the actual challenge is to define new biomarkers and non-invasive technologies to measure neuropathological changes in vivo at pre-symptomatic stages. Recent evidences obtained from human samples and mouse models indicate the possibility to detect protein aggregates and other pathological features in the retina, paving the road for non-invasive rapid detection of AD biomarkers. Here, we report the presence of amyloid beta plaques, tau tangles, neurodegeneration and detrimental astrocyte and microglia activation according to a disease associated microglia phenotype (DAM). Thus, we propose the human retina as a useful site for the detection of cellular and molecular changes associated with Alzheimer’s disease.
- Published
- 2019
- Full Text
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8. Correction: IL6 Inhibits HBV Transcription by Targeting the Epigenetic Control of the Nuclear cccDNA Minichromosome.
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Gianna Aurora Palumbo, Cecilia Scisciani, Natalia Pediconi, Leonardo Lupacchini, Dulce Alfaiate, Francesca Guerrieri, Ludovica Calvo, Debora Salerno, Silvia Di Cocco, Massimo Levrero, and Laura Belloni
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Medicine ,Science - Published
- 2015
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9. IL6 Inhibits HBV Transcription by Targeting the Epigenetic Control of the Nuclear cccDNA Minichromosome.
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Gianna Aurora Palumbo, Cecilia Scisciani, Natalia Pediconi, Leonardo Lupacchini, Dulce Alfalate, Francesca Guerrieri, Ludovica Calvo, Debora Salerno, Silvia Di Cocco, Massimo Levrero, and Laura Belloni
- Subjects
Medicine ,Science - Abstract
The HBV covalently closed circular DNA (cccDNA) is organized as a mini-chromosome in the nuclei of infected hepatocytes by histone and non-histone proteins. Transcription from the cccDNA of the RNA replicative intermediate termed pre-genome (pgRNA), is the critical step for genome amplification and ultimately determines the rate of HBV replication. Multiple evidences suggest that cccDNA epigenetic modifications, such as histone modifications and DNA methylation, participate in regulating the transcriptional activity of the HBV cccDNA. Inflammatory cytokines (TNFα, LTβ) and the pleiotropic cytokine interleukin-6 (IL6) inhibit hepatitis B virus (HBV) replication and transcription. Here we show, in HepG2 cells transfected with linear HBV monomers and HBV-infected NTCP-HepG2 cells, that IL6 treatment leads to a reduction of cccDNA-bound histone acetylation paralleled by a rapid decrease in 3.5kb/pgRNA and subgenomic HBV RNAs transcription without affecting cccDNA chromatinization or cccDNA levels. IL6 repressive effect on HBV replication is mediated by a loss of HNF1α and HNF4α binding to the cccDNA and a redistribution of STAT3 binding from the cccDNA to IL6 cellular target genes.
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- 2015
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10. Antibiotics Treatment Modulates Microglia-Synapses Interaction Through CX3CL1/CX3CR1 Axis
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Francesca Guerrieri, Barbara Cortese, Alfonso Grimaldi, Francesca Pagani, Federica Cordella, Natalia Pediconi, Maria Giubettini, Giuseppe Rubens Pascucci, Cristina Limatola, Caterina Sanchini, Bernadette Basilico, Giuseppina D'Alessandro, Maria Rosito, Fabrizio Antonangeli, Davide Ragozzino, Giovanna Peruzzi, Laura Ferrucci, and Silvia Di Angelantonio
- Subjects
Microglia ,Chemistry ,medicine.drug_class ,Gut–brain axis ,Antibiotics ,Hippocampus ,digestive system ,medicine.anatomical_structure ,nervous system ,CX3CR1 ,physiology ,medicine ,Patch clamp ,CX3CL1 ,Neuroscience - Abstract
‘Dysbiosis’ of the adult gut microbiota, in response to challenges such as infection, altered diet, stress, and antibiotics treatment has been recently linked to pathological alteration of brain func-tion and behavior. Moreover, gut microbiota composition constantly controls microglia matura-tion as revealed by morphological observations and gene expression analysis. However, it is un-clear whether gut microbiota influences microglia functional properties and crosstalk with neu-rons, known to shape and modulate synaptic development and function. Here, we investigated how antibiotic mediated alteration of the gut microbiota influences microglial and neuronal functions in adult mice hippocampus. Hippocampal microglia from adult mice treated with oral antibiotics exhibited increased microglia density, altered basal patrolling activity, and impaired process rearrangement in response to damage. Patch clamp recordings at CA3-CA1 synapses revealed that antibiotics treatment alters neuronal functions, reducing spontaneous postsynaptic glutamatergic currents and decreasing synaptic connectivity, without reducing dendritic spines density. The effect of dysbiosis on neuronal functions are mediated by microglia-neuron cross-talk through the CX3CL1-CX3CR1 axis, as antibiotics treatment of CX3CR1 deficient mice, mod-ulates microglia density and processes rearrangement leaving unaltered synaptic function. To-gether, our findings show that the antibiotics alteration of gut microbiota impairs synaptic effi-cacy, probably through CX3CL1-CX3CR1 signaling supporting microglia as a major player in in the gut-brain axis, and in particular in the gut microbiota-to-neuron communication pathway.
- Published
- 2021
11. Design and synthesis of piperazine-based compounds conjugated to humanized ferritin as delivery system of siRNA in cancer cells
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Giovanna Peruzzi, Maria Elisa Crestoni, Chiara Massera, Bruno Botta, Davide Corinti, Natalia Pediconi, Deborah Quaglio, Cristina Del Plato, Alberto Boffi, Constantinos M. Athanassopoulos, Alessandro Arcovito, Paola Baiocco, Mattia Mori, Franco Ugozzoli, and Francesca Ghirga
- Subjects
Small interfering RNA ,Pharmaceutical Science ,bioconjugation ,Chemistry Techniques, Synthetic ,02 engineering and technology ,humanized ferritin ,siRNA ,piperazine based compounds ,01 natural sciences ,HeLa ,polyamine ,Gene expression ,RNA, Small Interfering ,Regulation of gene expression ,Drug Carriers ,Tumor ,biology ,Chemistry ,Transfection ,021001 nanoscience & nanotechnology ,Cell biology ,0210 nano-technology ,Biotechnology ,nanoparticles ,ferritin ,drug delivery ,Biomedical Engineering ,Bioengineering ,Transferrin receptor ,Small Interfering ,Article ,Cell Line ,Cell Line, Tumor ,Humans ,Gene silencing ,Piperazine ,Settore BIO/10 - BIOCHIMICA ,Pharmacology ,010405 organic chemistry ,Synthetic ,Organic Chemistry ,Chemistry Techniques ,biology.organism_classification ,0104 chemical sciences ,Ferritins ,Drug Design ,Cancer cell ,RNA - Abstract
Gene expression regulation by small interfering RNA (siRNA) holds promise in treating a wide range of diseases through selective gene silencing. However, successful clinical application of nucleic acid-based therapy requires novel delivery options. Herein, to achieve efficient delivery of negatively charged siRNA duplexes, the internal cavity of “humanized” chimeric Archaeal ferritin (HumAfFt) was specifically decorated with novel cationic piperazine-based compounds (PAs). By coupling these rigid-rod-like amines with thiol-reactive reagents, chemoselective conjugation was efficiently afforded on topologically selected cysteine residues properly located inside HumAfFt. The capability of PAs-HumAfFt to host and deliver siRNA molecules through human transferrin receptor (TfR1), overexpressed in many cancer cells, was explored. These systems allowed siRNA delivery into HeLa, HepG2, and MCF-7 cancer cells with improved silencing effect on glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene expression with respect to traditional transfection methodologies and provided a promising TfR1-targeting system for multifunctional siRNA delivery to therapeutic applications.
- Published
- 2021
12. Downregulation of miR-326 and its host gene β-arrestin1 induces pro-survival activity of E2F1 and promotes medulloblastoma growth
- Author
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Enrico De Smaele, Luana Abballe, Massimo Levrero, Alessandra Vacca, Zein Mersini Besharat, Stefan M. Pfister, Lucia Di Marcotullio, Claudia Sabato, Agnese Po, Evelina Miele, Elisabetta Ferretti, Franco Locatelli, Angela Mastronuzzi, Felice Giangaspero, Marcel Kool, Andrea Carai, Gianluca Canettieri, Antonello Mai, Natalia Pediconi, and Giuseppina Catanzaro
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0301 basic medicine ,Male ,Cancer Research ,Mice, SCID ,Mice ,0302 clinical medicine ,Mice, Inbred NOD ,E2F1 ,RNA, Neoplasm ,ARRB1 ,EZH2 ,medulloblastoma ,miR-326 ,Research Articles ,General Medicine ,lcsh:Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,Neoplasm Proteins ,Gene Expression Regulation, Neoplastic ,beta-Arrestin 1 ,Oncology ,Settore MED/38 - PEDIATRIA GENERALE E SPECIALISTICA ,030220 oncology & carcinogenesis ,Molecular Medicine ,Female ,Research Article ,Down-Regulation ,Biology ,lcsh:RC254-282 ,03 medical and health sciences ,Downregulation and upregulation ,Cancer stem cell ,Genetics ,medicine ,Animals ,Humans ,Cerebellar Neoplasms ,Medulloblastoma ,Messenger RNA ,miR‐326 ,medicine.disease ,MicroRNAs ,030104 developmental biology ,HEK293 Cells ,Tumor progression ,Cancer research ,Ectopic expression ,E2F1 Transcription Factor - Abstract
Medulloblastoma (MB) is a malignant pediatric brain tumor, and we reveal a new regulatory molecular axis critical for MB progression. Low expression of miR‐326 and its host gene β‐arrestin1 (ARRB1) promotes tumor growth enhancing the E2F1 pro‐survival function. High levels of EZH2 are responsible for the presence of H3K27me3 that controls miR‐326 and ARRB1 through a bivalent domain. Restoration of miR‐326 and re‐expression of ARRB1 reverse E2F1 function into pro‐apoptotic activity., Persistent mortality rates of medulloblastoma (MB) and severe side effects of the current therapies require the definition of the molecular mechanisms that contribute to tumor progression. Using cultured MB cancer stem cells and xenograft tumors generated in mice, we show that low expression of miR‐326 and its host gene β‐arrestin1 (ARRB1) promotes tumor growth enhancing the E2F1 pro‐survival function. Our models revealed that miR‐326 and ARRB1 are controlled by a bivalent domain, since the H3K27me3 repressive mark is found at their regulatory region together with the activation‐associated H3K4me3 mark. High levels of EZH2, a feature of MB, are responsible for the presence of H3K27me3. Ectopic expression of miR‐326 and ARRB1 provides hints into how their low levels regulate E2F1 activity. MiR‐326 targets E2F1 mRNA, thereby reducing its protein levels; ARRB1, triggering E2F1 acetylation, reverses its function into pro‐apoptotic activity. Similar to miR‐326 and ARRB1 overexpression, we also show that EZH2 inhibition restores miR‐326/ARRB1 expression, limiting E2F1 pro‐proliferative activity. Our results reveal a new regulatory molecular axis critical for MB progression.
- Published
- 2021
13. Neuroinflammatory processes, A1 astrocyte activation and protein aggregation in the retina of Alzheimer’s and Parkinson's disease patients: Possible biomarkers for early diagnosis
- Author
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Maria Rosito, Rocco Pizzarelli, Maria Giubettini, Federica Lo Greco, Natalia Pediconi, Silvia Di Angelantonio, and Alfonso Grimaldi
- Subjects
Retina ,Parkinson's disease ,Epidemiology ,business.industry ,Health Policy ,Protein aggregation ,medicine.disease ,Psychiatry and Mental health ,Cellular and Molecular Neuroscience ,medicine.anatomical_structure ,Developmental Neuroscience ,medicine ,Neurology (clinical) ,Geriatrics and Gerontology ,business ,Neuroscience ,Astrocyte - Published
- 2020
14. Antibiotics Treatment Modulates Microglia–Synapses Interaction
- Author
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Davide Ragozzino, Maria Rosito, Barbara Cortese, Francesca Pagani, Francesca Guerrieri, Federica Cordella, Laura Ferrucci, Giuseppe Rubens Pascucci, Fabrizio Antonangeli, Silvia Di Angelantonio, Giovanna Peruzzi, Caterina Sanchini, Alfonso Grimaldi, Giuseppina D'Alessandro, Cristina Limatola, Maria Giubettini, Natalia Pediconi, and Bernadette Basilico
- Subjects
Dendritic spine ,hippocampus ,QH301-705.5 ,Gut–brain axis ,CX3C Chemokine Receptor 1 ,Glutamic Acid ,microglia ,Hippocampus ,Gut flora ,Synaptic Transmission ,patch clamp ,digestive system ,Article ,antibiotics ,Mice ,glutamatergic synapses ,gut-brain axis ,hippocampal slices, CX3CL1/CX3CR1 ,Postsynaptic potential ,CX3CL1/CX3CR1 ,CX3CR1 ,medicine ,Animals ,Biology (General) ,gut–brain axis ,Inflammation ,Neurons ,biology ,Microglia ,Chemokine CX3CL1 ,hippocampal slices ,General Medicine ,biology.organism_classification ,medicine.disease ,Anti-Bacterial Agents ,Cell biology ,medicine.anatomical_structure ,Gene Expression Regulation ,nervous system ,Synapses ,Dysbiosis ,Signal Transduction - Abstract
‘Dysbiosis’ of the adult gut microbiota, in response to challenges such as infection, altered diet, stress, and antibiotics treatment has been recently linked to pathological alteration of brain function and behavior. Moreover, gut microbiota composition constantly controls microglia maturation, as revealed by morphological observations and gene expression analysis. However, it is unclear whether microglia functional properties and crosstalk with neurons, known to shape and modulate synaptic development and function, are influenced by the gut microbiota. Here, we investigated how antibiotic-mediated alteration of the gut microbiota influences microglial and neuronal functions in adult mice hippocampus. Hippocampal microglia from adult mice treated with oral antibiotics exhibited increased microglia density, altered basal patrolling activity, and impaired process rearrangement in response to damage. Patch clamp recordings at CA3-CA1 synapses revealed that antibiotics treatment alters neuronal functions, reducing spontaneous postsynaptic glutamatergic currents and decreasing synaptic connectivity, without reducing dendritic spines density. Antibiotics treatment was unable to modulate synaptic function in CX3CR1-deficient mice, pointing to an involvement of microglia–neuron crosstalk through the CX3CL1/CX3CR1 axis in the effect of dysbiosis on neuronal functions. Together, our findings show that antibiotic alteration of gut microbiota impairs synaptic efficacy, suggesting that CX3CL1/CX3CR1 signaling supporting microglia is a major player in in the gut–brain axis, and in particular in the gut microbiota-to-neuron communication pathway.
- Published
- 2021
15. Inducing and Characterizing Vesicular Steatosis in Differentiated HepaRG Cells
- Author
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Abigail D G Nunn, Natalia Pediconi, Laura Belloni, Silvia Di Cocco, Silvia Piconese, Massimo Levrero, and Debora Salerno
- Subjects
Cirrhosis ,Cellular differentiation ,General Chemical Engineering ,0206 medical engineering ,02 engineering and technology ,General Biochemistry, Genetics and Molecular Biology ,Cell Line ,Mice ,Fibrosis ,In vivo ,NAFLD ,Lipid droplet ,medicine ,Animals ,Humans ,Vesicular steatosis ,CARS microscopy ,HepaRG ,Issue 149 ,Lipid droplets ,Liver ,Medicine ,General Immunology and Microbiology ,General Neuroscience ,Fatty liver ,Cell Differentiation ,021001 nanoscience & nanotechnology ,medicine.disease ,020601 biomedical engineering ,Cell biology ,Fatty Liver ,Hepatocytes ,Steatohepatitis ,Steatosis ,0210 nano-technology - Abstract
Hepatic steatosis represents a metabolic dysfunction that results from an accumulation of triglyceride-containing lipid droplets in hepatocytes. Excessive fat accumulation leads to non-alcoholic fatty liver disease (NAFLD), which is potentially reversible and may evolve into non-alcoholic steatohepatitis (NASH) and eventually cirrhosis and hepatocellular carcinoma (HCC). The molecular mechanisms linking lipid accumulation in hepatocytes with the progression to NASH, irreversible liver damage, fibrosis, cirrhosis, and even HCC still remains unclear. To this end, several in vitro and in vivo models have been developed to elucidate the pathological processes that cause NAFLD. In the present study, we describe a cellular model for the induction of liver vesicular steatosis that consists of DMSO-differentiated human hepatic HepaRG cells treated with the fatty acid salt sodium oleate. Indeed, sodium oleate-treated HepaRG cells accumulate lipid droplets in the cytoplasm and show typical features of steatosis. This in vitro human model represents a valuable alternative to in vivo mice models as well as to the primary human hepatocytes. We also present a comparison of several methods for the quantification and evaluation of fat accumulation in HepaRG cells, including Oil Red O staining, cytofluorimetric Bodipy measurement, metabolic gene expression analysis by qPCR, and coherent anti-Stokes Raman scattering (CARS) microscopy. CARS imaging combines the chemical specificity of Raman spectroscopy, a chemical analysis technique well-known in materials science applications, with the benefits of high-speed, high-resolution non-linear optical microscopies to allow precise quantification of lipid accumulation and lipid droplet dynamics. The establishment of an efficient in vitro model for the induction of vesicular steatosis, alongside an accurate method for the quantification and characterization of lipid accumulation, could lead to the development of early stage diagnosis of NAFLD via the identification of molecular markers, and to the generation of new treatment strategies.
- Published
- 2019
16. EZH2, JMJD3 and UTX epigenetically regulate hepatic plasticity inducing retro-differentiation and proliferation of liver cells
- Author
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Annapaola Angrisani, Debora Salerno, Leonardo Lupacchini, Enrico De Smaele, Giovanna Peruzzi, Massimo Levrero, Laura Belloni, and Natalia Pediconi
- Subjects
0301 basic medicine ,Cancer Research ,Jumonji Domain-Containing Histone Demethylases ,Methyltransferase ,Indoles ,Liver cytology ,Pyridones ,Immunology ,macromolecular substances ,Methylation ,Article ,Cell Line ,Epigenesis, Genetic ,Histones ,03 medical and health sciences ,Cellular and Molecular Neuroscience ,0302 clinical medicine ,Demethylase activity ,Humans ,Enhancer of Zeste Homolog 2 Protein ,lcsh:QH573-671 ,Cells, Cultured ,Cell Proliferation ,Regulation of gene expression ,Histone Demethylases ,JMJD3 ,UTX ,EZH2 ,liver retro-differentiation ,liver plasticity ,GSK-J4 ,GSK-126 ,HepaRG ,histone methylation ,H3K27me3 ,epigenetic ,Principal Component Analysis ,DNA methylation ,lcsh:Cytology ,Chemistry ,Gene Expression Profiling ,Lysine ,fungi ,Gene Expression Regulation, Developmental ,Cell Differentiation ,Cell Biology ,Benzazepines ,Cell biology ,030104 developmental biology ,Pyrimidines ,Liver ,030220 oncology & carcinogenesis ,Histone methyltransferase ,Hepatic stellate cell ,Hepatocytes ,Biomarkers - Abstract
Modification of histones by lysine methylation plays a role in many biological processes, and it is dynamically regulated by several histone methyltransferases and demethylases. The polycomb repressive complex contains the H3K27 methyltransferase EZH2 and controls dimethylation and trimethylation of H3K27 (H3K27me2/3), which trigger gene suppression. JMJD3 and UTX have been identified as H3K27 demethylases that catalyze the demethylation of H3K27me2/3, which in turns lead to gene transcriptional activation. EZH2, JMJD3 and UTX have been extensively studied for their involvement in development, immune system, neurodegenerative disease, and cancer. However, their role in molecular mechanisms underlying the differentiation process of hepatic cells is yet to be elucidated. Here, we show that EZH2 methyltransferase and JMJD3/UTX demethylases were deregulated during hepatic differentiation of human HepaRG cells resulting in a strong reduction of H3K27 methylation levels. Inhibition of JMJD3 and UTX H3K27 demethylase activity by GSK-J4 epi-drug reverted phenotype of HepaRG DMSO-differentiated cells and human primary hepatocytes, drastically decreasing expression of hepatic markers and inducing cell proliferation. In parallel, inhibition of EZH2 H3K27me3 activity by GSK-126 epi-drug induced upregulation of hepatic markers and downregulated the expression of cell cycle inhibitor genes. To conclude, we demonstrated that modulation of H3K27 methylation by inhibiting methyl-transferase and dimethyl-transferase activity influences the differentiation status of hepatic cells, identifying a possible new role of EZH2, JMJD3 and UTX epi-drugs to modulate hepatic cell plasticity.
- Published
- 2019
17. Metformin-induced ablation of microRNA 21-5p releases Sestrin-1 and CAB39L antitumoral activities
- Author
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Giovanni Blandino, Mario Cioce, Paola Muti, Patrizia Pasanisi, Gregory R. Steinberg, Franco Berrino, Maurizio Fanciulli, Rebecca J. Ford, Federica Mori, Claudio Pulito, Ludovica Ciuffreda, Sabrina Strano, Maria Ferraiuolo, Carlo Campagnoli, Andrea Sacconi, Michele Milella, Frauke Goeman, Natalia Pediconi, and Massimo Levrero
- Subjects
0301 basic medicine ,cancer metabolism ,Biochemistry ,Article ,03 medical and health sciences ,0302 clinical medicine ,Breast cancer ,microRNA ,Genetics ,medicine ,Protein kinase A ,Molecular Biology ,PI3K/AKT/mTOR pathway ,miRNA ,Everolimus ,business.industry ,Cancer ,Cell Biology ,everolimus ,medicine.disease ,Metformin ,030104 developmental biology ,030220 oncology & carcinogenesis ,mTOR ,Cancer research ,Ectopic expression ,metformin ,cell biology ,molecular biology ,biochemistry ,genetics ,business ,medicine.drug - Abstract
Metformin is a commonly prescribed type II diabetes medication that exhibits promising anticancer effects. Recently, these effects were found to be associated, at least in part, with a modulation of microRNA expression. However, the mechanisms by which single modulated microRNAs mediate the anticancer effects of metformin are not entirely clear and knowledge of such a process could be vital to maximize the potential therapeutic benefits of this safe and well-tolerated therapy. Our analysis here revealed that the expression of miR-21-5p was downregulated in multiple breast cancer cell lines treated with pharmacologically relevant doses of metformin. Interestingly, the inhibition of miR-21-5p following metformin treatment was also observed in mouse breast cancer xenografts and in sera from 96 breast cancer patients. This modulation occurred at the levels of both pri-miR-21 and pre-miR-21, suggesting transcriptional modulation. Antagomir-mediated ablation of miR-21-5p phenocopied the effects of metformin on both the clonogenicity and migration of the treated cells, while ectopic expression of miR-21-5p had the opposite effect. Mechanistically, this reduction in miR-21-5p enhanced the expression of critical upstream activators of the AMP-activated protein kinase, calcium-binding protein 39-like and Sestrin-1, leading to AMP-activated protein kinase activation and inhibition of mammalian target of rapamycin signaling. Importantly, these effects of metformin were synergistic with those of everolimus, a clinically relevant mammalian target of rapamycin inhibitor, and were independent of the phosphatase and tensin homolog status. This highlights the potential relevance of metformin in combinatorial settings for the treatment of breast cancer.
- Published
- 2017
18. Erratum: The histone deacetylase inhibiting drug Entinostat induces lipid accumulation in differentiated HepaRG cells
- Author
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Abigail D. G. Nunn, Tullio Scopigno, Natalia Pediconi, Massimo Levrero, Henning Hagman, Juris Kiskis, and Annika Enejder
- Subjects
Multidisciplinary ,Article - Abstract
Dietary overload of toxic, free metabolic intermediates leads to disrupted insulin signalling and fatty liver disease. However, it was recently reported that this pathway might not be universal: depletion of histone deacetylase (HDAC) enhances insulin sensitivity alongside hepatic lipid accumulation in mice, but the mechanistic role of microscopic lipid structure in this effect remains unclear. Here we study the effect of Entinostat, a synthetic HDAC inhibitor undergoing clinical trials, on hepatic lipid metabolism in the paradigmatic HepaRG liver cell line. Specifically, we statistically quantify lipid droplet morphology at single cell level utilizing label-free microscopy, coherent anti-Stokes Raman scattering, supported by gene expression. We observe Entinostat efficiently rerouting carbohydrates and free-fatty acids into lipid droplets, upregulating lipid coat protein gene Plin4, and relocating droplets nearer to the nucleus. Our results demonstrate the power of Entinostat to promote lipid synthesis and storage, allowing reduced systemic sugar levels and sequestration of toxic metabolites within protected protein-coated droplets, suggesting a potential therapeutic strategy for diseases such as diabetes and metabolic syndrome.
- Published
- 2016
19. THU-371-Modulation of H3K27 methylation by EZH2 and UTX/JMJD3 small molecules inhibitors impacts on proliferation and differentiation of hepatic progenitor cells and differentiated hepatocytes plasticity
- Author
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Laura Belloni, Natalia Pediconi, Giovanna Peruzzi, Debora Salerno, Enrico De Smaele, Leonardo Lupacchini, Annapaola Angrisani, and Massimo Levrero
- Subjects
Hepatology ,Chemistry ,EZH2 ,H3k27 methylation ,Plasticity ,Progenitor cell ,Small molecule ,Cell biology - Published
- 2019
20. Pathobiology of Hepatitis B Virus-Induced Carcinogenesis
- Author
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Laura Belloni, Francesca Guerrieri, Massimo Levrero, and Natalia Pediconi
- Subjects
Hepatitis B virus ,Genome instability ,Regulation of gene expression ,HBx ,Cancer research ,medicine ,Wnt signaling pathway ,Epigenetics ,Biology ,medicine.disease_cause ,Carcinogenesis ,digestive system diseases ,Chromatin - Abstract
Hepatitis B virus (HBV) contributes to hepatocellular carcinoma (HCC) development through direct and indirect mechanisms. HBV DNA integration into the host genome occurs at early steps of clonal tumor expansion and induces both genomic instability and direct insertional mutagenesis of diverse cancer-related genes. Prolonged expression of the viral regulatory protein HBx and/or altered versions of the PreS/S envelope proteins deregulates cell transcription and proliferation control and sensitizes liver cells to carcinogenic factors. Accumulation of preS1 large envelope proteins and/or preS2/S mutant proteins activates the unfold proteins response (UPR) that can contribute to hepatocyte transformation. Epigenetic changes targeting the expression of tumor-suppressor genes occur early in the development of HCC. A major role is played by HBx that is recruited on cellular chromatin and modulates chromatin dynamics at specific gene loci. Compared with tumors associated with other risk factors, HBV-related tumors have a higher rate of chromosomal alterations, p53 inactivation by mutations and overexpression of fetal liver/hepatic progenitor cells genes. The wnt/β-catenin pathway is also often activated but HBV-related tumors display a low rate of activating β-catenin mutations. HBV-related HCCs may arise on non-cirrhotic livers, further supporting the notion that HBV plays a direct role in liver transformation by triggering both common and etiology-specific oncogenic pathways in addition to stimulating the host immune response and driving liver chronic necro-inflammation.
- Published
- 2016
21. EZH2 methyltransferase and JMJD3/UTX demethylases are involved in hepatocytic differentiation and liver cancer cells plasticity
- Author
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Natalia Pediconi, Laura Belloni, Giovanna Peruzzi, Debora Salerno, Massimo Levrero, Antonello Mai, Leonardo Lupacchini, D. Rotili, and S. Di Cocco
- Subjects
Genetics ,Methyltransferase ,Hepatology ,EZH2 ,medicine ,Biology ,Liver cancer ,medicine.disease ,Cell biology - Published
- 2017
22. The Transcriptional Coactivator Yes-Associated Protein Drives p73 Gene-Target Specificity in Response to DNA Damage
- Author
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Natalia Pediconi, Giovanni Blandino, Gennaro Citro, Massimo Levrero, Giannino Del Sal, Olimpia Monti, Alexander Damalas, Ada Sacchi, Sabrina Strano, Fiamma Mantovani, Alessia Baccarini, Giulia Fontemaggi, Eleonora Lapi, Strano, S, Monti, O, Pediconi, N, Baccarini, A, Fontemaggi, G, Lapi, E, Mantovani, Fiamma, Damalas, A, Citro, G, Sacchi, A, DEL SAL, Giannino, Levrero, M, and Blandino, G.
- Subjects
Transcription, Genetic ,Cell ,Cell Cycle Proteins ,Promyelocytic Leukemia Protein ,Genes, Reporter ,Antibiotics ,Acetylation ,Antibiotics, Antineoplastic ,Apoptosis Regulatory Proteins ,Cisplatin ,DNA Damage ,DNA-Binding Proteins ,Doxorubicin ,Genes, Tumor Suppressor ,Humans ,Neoplasm Proteins ,Nuclear Proteins ,Proteins ,Trans-Activators ,Transcription Factors ,Tumor Suppressor Proteins ,Tumor Protein p73 ,skin and connective tissue diseases ,apoptosis ,Gene targeting ,Antineoplastic ,Histone ,medicine.anatomical_structure ,Transcriptional Coactivator ,p73 tumor suppressor ,Transcription ,Tumor Suppressor ,DNA damage ,Biology ,Promyelocytic leukemia protein ,Genetic ,Coactivator ,medicine ,Gene silencing ,neoplasms ,Gene ,Reporter ,Molecular Biology ,PML ,Promoter ,Cell Biology ,Genes ,Nuclear receptor coactivator 3 ,biology.protein ,Nuclear receptor coactivator 2 ,Cancer research - Abstract
The transcriptional coactivator Yes-associated protein (YAP) has been shown to interact with and to enhance p73-dependent apoptosis in response to DNA damage. Here, we show that YAP requires the promyelocytic leukemia gene (PML) and nuclear body localization to coactivate p73. YAP imparts selectivity to p73 by promoting the activation of a subset of p53 and/or p73 target promoters. Endogenous p73, YAP, and p300 proteins are concomitantly recruited onto the regulatory regions of the apoptotic target gene p53AIP1 only when cells are exposed to apoptotic conditions. Silencing of YAP by specific siRNA impairs p300 recruitment and reduces histone acetylation on the p53AIP1 target gene, resulting in delayed or reduced apoptosis mediated by p73. We also found that YAP contributes to the DNA damage-induced accumulation of p73 and potentiates the p300-mediated acetylation of p73. Altogether, our findings identify YAP as a key determinant of p73 gene targeting in response to DNA damage.
- Published
- 2005
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23. Regulation of the p300 HAT domain via a novel activation loop
- Author
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Vittorio Sartorelli, Jiemin Wong, Natalia Pediconi, Qingyuan Ge, Ling Wang, Marcella Fulco, Robert G. Roeder, Dianzheng Zhang, Paul R. Thompson, Dongxia Wang, Philip A. Cole, Massimo Levrero, Woojin An, and Robert J. Cotter
- Subjects
Enzymologic ,Lysine Acetyltransferases ,Molecular Sequence Data ,Protein domain ,Lysine ,Sequence Homology ,Biology ,Gene Expression Regulation, Enzymologic ,Acetyl Coenzyme A ,Acetyltransferases ,Structural Biology ,Acetylation ,Amino Acid Sequence ,Animals ,Cloning, Molecular ,Conserved Sequence ,DNA Primers ,Enzyme Activation ,Escherichia coli ,Escherichia coli Proteins ,Histone Acetyltransferases ,Kinetics ,Recombinant Proteins ,Sequence Alignment ,Sequence Homology, Amino Acid ,parasitic diseases ,Gene expression ,Molecular Biology ,Kinase ,Autophosphorylation ,Molecular ,Histone acetyltransferase ,Cell biology ,Amino Acid ,Gene Expression Regulation ,Biochemistry ,Activation loop ,biology.protein ,Cloning - Abstract
The transcriptional coactivator p300 is a histone acetyltransferase (HAT) whose function is critical for regulating gene expression in mammalian cells. However, the molecular events that regulate p300 HAT activity are poorly understood. We evaluated autoacetylation of the p300 HAT protein domain to determine its function. Using expressed protein ligation, the p300 HAT protein domain was generated in hypoacetylated form and found to have reduced catalytic activity. This basal catalytic rate was stimulated by autoacetylation of several key lysine sites within an apparent activation loop motif. This post-translational modification and catalytic regulation of p300 HAT activity is conceptually analogous to the activation of most protein kinases by autophosphorylation. We therefore propose that this autoregulatory loop could influence the impact of p300 on a wide variety of signaling and transcriptional events.
- Published
- 2004
24. TP63 and TP73 in cancer, an unresolved 'family' puzzle of complexity, redundancy and hierarchy
- Author
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Francesca Fausti, Laura Belloni, Elisabetta Botti, Francesca Guerrieri, Alessandra Narcisi, Natalia Pediconi, Antonio Costanzo, and Massimo Levrero
- Subjects
Gene isoform ,Development ,TP53 ,TP63 ,TP73 ,Tumor suppressors ,Animals ,Carcinogenesis ,DNA-Binding Proteins ,Humans ,Neoplasms ,Nuclear Proteins ,Transcription Factors ,Tumor Protein p73 ,Tumor Suppressor Protein p53 ,Tumor Suppressor Proteins ,media_common.quotation_subject ,Biophysics ,Computational biology ,Biology ,Biochemistry ,Structural Biology ,Genetics ,Redundancy (engineering) ,Gene family ,Molecular Biology ,Gene ,Transcription factor ,drug therapy/metabolism/pathology ,media_common ,animals ,dna-binding proteins ,tp53 ,chemistry/metabolism ,tp63 ,development ,tp73 ,metabolism ,neoplasms ,tumor suppressors ,tumor suppressor proteins ,transcription factors ,humans ,tumor suppressor protein p53 ,carcinogenesis ,nuclear proteins ,Settore MED/35 - Malattie Cutanee e Veneree ,Hierarchy (mathematics) ,Repertoire ,Longevity ,Cell Biology - Abstract
TP53 belongs to a small gene family that includes, in mammals, two additional paralogs, TP63 and TP73. The p63 and p73 proteins are structurally and functionally similar to p53 and their activity as transcription factors is regulated by a wide repertoire of shared and unique post-translational modifications and interactions with regulatory cofactors. p63 and p73 have important functions in embryonic development and differentiation but are also involved in tumor suppression. The biology of p63 and p73 is complex since both TP63 and TP73 genes are transcribed into a variety of different isoforms that give rise to proteins with antagonistic properties, the TA-isoforms that act as tumor-suppressors and DN-isoforms that behave as proto-oncogenes. The p53 family as a whole behaves as a signaling “network” that integrates developmental, metabolic and stress signals to control cell metabolism, differentiation, longevity, proliferation and death. Despite the progress of our knowledge, the unresolved puzzle of complexity, redundancy and hierarchy in the p53 family continues to represent a formidable challenge.
- Published
- 2014
25. Molecular Mechanisms of HBV-Associated Hepatocarcinogenesis
- Author
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Francesca Guerrieri, Massimo Levrero, Laura Belloni, and Natalia Pediconi
- Subjects
Gene Expression Regulation, Viral ,Genome instability ,Hepatitis B virus ,Carcinoma, Hepatocellular ,mirnas ,Biology ,medicine.disease_cause ,Epigenesis, Genetic ,Hepatitis B, Chronic ,Risk Factors ,medicine ,Animals ,Humans ,Viral Regulatory and Accessory Proteins ,Epigenetics ,PI3K/AKT/mTOR pathway ,Regulation of gene expression ,hepatocellular carcinoma (hcc) ,Hepatology ,epigenetics ,hepatitis b virus (hbv) ,Liver Neoplasms ,Wnt signaling pathway ,Cell Transformation, Viral ,Molecular biology ,digestive system diseases ,Chromatin ,Gene Expression Regulation, Neoplastic ,HBx ,hbx protein ,Host-Pathogen Interactions ,Trans-Activators ,Cancer research ,Signal Transduction - Abstract
Hepatitis B virus (HBV) contributes to hepatocellular carcinoma (HCC) development through direct and indirect mechanisms. HBV-DNA integration into the host genome occurs at early steps of clonal tumor expansion and induces both genomic instability and direct insertional mutagenesis of diverse cancer-related genes. Prolonged expression of the viral regulatory protein HBx and the large envelope protein deregulate the cellular transcription program and proliferation control and sensitize liver cells to carcinogenic factors. Epigenetic changes targeting the expression of tumor suppressor genes occur early in the development of HCC. A major role is played by HBx that is recruited on cellular chromatin and modulates chromatin dynamics at specific gene loci. Compared with tumors associated with other risk factors, HBV-related tumors have a higher rate of chromosomal alterations and p53 inactivation by mutations, overexpress fetal liver/hepatic progenitor cells genes, and show a specific activation of the AKT pathway. The wnt/β-catenin pathway is also often activated, but HBV-related tumors display a low rate of activating β-catenin mutations. All available evidence strongly supports the notion that chronic HBV infection triggers both common and etiology-specific oncogenic pathways, thus playing a direct role beyond stimulation of host immune responses and chronic necroinflammatory liver disease.
- Published
- 2013
26. Transcriptional regulation of miR-224 upregulated in human HCCs by NFκB inflammatory pathways
- Author
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Melchiorre Cervello, Giuseppe Montalto, Paolo D'Onorio De Meo, Rossana De Iaco, Francesca Guerrieri, V. Schinzari, Natalia Pediconi, Giovanni Raimondo, C. Scisciani, Massimo Levrero, Teresa Pollicino, Stefania Vossio, Scisciani, C., Vossio, S., Guerrieri, F., Schinzari, V., De Iaco, R., D'Onorio De Meo, P., Cervello, M., Montalto, G., Pollicino, T., Raimondo, G., Levrero, M., and Pediconi, N.
- Subjects
Lipopolysaccharides ,Liver Cirrhosis ,Male ,Carcinoma, Hepatocellular ,Transcription, Genetic ,Liver Cirrhosi ,Lipopolysaccharide ,Biology ,Cell Movement ,Cell Line, Tumor ,microRNA ,Transcriptional regulation ,Humans ,NF kappa B ,HCC ,mir-224 ,nfκb ,hcc ,mirnas ,transcription ,Transcription factor ,Lymphotoxin-alpha ,miRNA ,Aged ,Hepatology ,miRNAs ,miR-224 ,Transcription ,Tumor Necrosis Factor-alpha ,Liver Neoplasms ,NF-kappa B ,MicroRNA ,HCCS ,Middle Aged ,NFKB1 ,Up-Regulation ,MicroRNAs ,IκBα ,Liver ,Liver Neoplasm ,Case-Control Studies ,Immunology ,Cancer research ,Tumor necrosis factor alpha ,Female ,Signal transduction ,Case-Control Studie ,NFκB ,Human ,Signal Transduction - Abstract
Background & Aims: miR-224 is up-regulated in human HCCs as compared to both paired peri-tumoral cirrhotic tissues and cirrhotic livers without HCC. Here, we have cloned the miR-224 regulatory region and characterized its transcriptional regulation by the NFκB-dependent inflammatory pathways. Methods: Mature miRNA expression was evaluated by a 2 step stem-loop real-time RT-PCR. The recruitment of polymerase II and transcription factors on the pre-miR-224 promoter has been assessed by ChIPSeq and ChIP. Results: We found miR-224 levels strongly up-regulated in both peri-tumoral cirrhotic livers and HCC samples as compared to normal livers. In silico analysis of the putative miR-224 promoter revealed multiple NFκB sites. We showed that LTα and TNFα activate transcription from the miR-224 promoter and of endogenous miR-224 expression in HCC cell lines, whereas the expression of miR-224 target API5 was reduced. Exogenously expressed p65/RelA activates the miR-224 promoter and a dominant negative form of IκBα (IκBSR) represses it. ChIP analysis showed that p65/NFκB is recruited on the miR-224 promoter and that its binding sharply increases after exposure to LPS, TNFα, and LTα. Altogether these findings link the inflammatory signals to NFκB-mediated activation of miR-224 expression. An antago-miR specific for miR-224 blocked LPS and LTα stimulated HCC cells migration and invasion. Conversely, the IKK inhibitor BMS-345541 blocks pre-miR-224-induced cellular migration and invasion. Conclusions: Our results identify p65/NFκB as a direct transcriptional regulator of miR-224 expression and link miR-224 up-regulation with the activation of the LPS, LTα, and TNFα inflammatory pathways and cell migration/invasion in HCC. © 2011 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.
- Published
- 2012
27. IL6 Inhibits HBV Transcription by Targeting the Epigenetic Control of the Nuclear cccDNA Minichromosome
- Author
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Francesca Guerrieri, Natalia Pediconi, C. Scisciani, Silvia Di Cocco, Leonardo Lupacchini, Laura Belloni, Massimo Levrero, G.A. Palumbo, Debora Salerno, Ludovica Calvo, and Dulce Alfalate
- Subjects
replication ,HBV RNA encapsidation signal epsilon ,hepatitis-b-virus ,lcsh:Medicine ,dna ,Biology ,liver ,medicine.disease_cause ,stat3 ,Transcription (biology) ,gene-expression ,interleukin-6 ,il-6 ,activation ,protein ,medicine ,Epigenetics ,lcsh:Science ,Hepatitis B virus ,Multidisciplinary ,lcsh:R ,virus diseases ,cccDNA ,Molecular biology ,digestive system diseases ,Chromatin ,Histone ,DNA methylation ,biology.protein ,lcsh:Q ,Research Article - Abstract
The HBV covalently closed circular DNA (cccDNA) is organized as a mini-chromosome in the nuclei of infected hepatocytes by histone and non-histone proteins. Transcription from the cccDNA of the RNA replicative intermediate termed pre-genome (pgRNA), is the critical step for genome amplification and ultimately determines the rate of HBV replication. Multiple evidences suggest that cccDNA epigenetic modifications, such as histone modifications and DNA methylation, participate in regulating the transcriptional activity of the HBV cccDNA. Inflammatory cytokines (TNFα, LTβ) and the pleiotropic cytokine interleukin-6 (IL6) inhibit hepatitis B virus (HBV) replication and transcription. Here we show, in HepG2 cells transfected with linear HBV monomers and HBV-infected NTCP-HepG2 cells, that IL6 treatment leads to a reduction of cccDNA-bound histone acetylation paralleled by a rapid decrease in 3.5kb/pgRNA and subgenomic HBV RNAs transcription without affecting cccDNA chromatinization or cccDNA levels. IL6 repressive effect on HBV replication is mediated by a loss of HNF1α and HNF4α binding to the cccDNA and a redistribution of STAT3 binding from the cccDNA to IL6 cellular target genes.
- Published
- 2015
28. IFN-α inhibits HBV transcription and replication in cell culture and in humanized mice by targeting the epigenetic regulation of the nuclear cccDNA minichromosome
- Author
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Lena Allweiss, Laura Belloni, Massimo Levrero, Joerg Petersen, Francesca Guerrieri, Teresa Pollicino, Maura Dandri, Giovanni Raimondo, Natalia Pediconi, and Tassilo Volz
- Subjects
Hepatitis B virus ,Transcription, Genetic ,Response element ,Cell Culture Techniques ,Mice, Transgenic ,Mice, SCID ,Biology ,medicine.disease_cause ,Virus Replication ,Chimerism ,epigenetic regulation ,Epigenesis, Genetic ,HBV infection ,IFN-stimulated response element ,IFN-α ,HBV covalently closed circular DNA (cccDNA) minichromosome ,Mice ,Minichromosome ,Transcription (biology) ,medicine ,Animals ,Humans ,Transcription factor ,Subgenomic mRNA ,virus diseases ,Interferon-alpha ,General Medicine ,cccDNA ,Virology ,digestive system diseases ,Viral replication ,DNA, Circular ,Research Article - Abstract
HBV infection remains a leading cause of death worldwide. IFN-α inhibits viral replication in vitro and in vivo, and pegylated IFN-α is a commonly administered treatment for individuals infected with HBV. The HBV genome contains a typical IFN-stimulated response element (ISRE), but the molecular mechanisms by which IFN-α suppresses HBV replication have not been established in relevant experimental systems. Here, we show that IFN-α inhibits HBV replication by decreasing the transcription of pregenomic RNA (pgRNA) and subgenomic RNA from the HBV covalently closed circular DNA (cccDNA) minichromosome, both in cultured cells in which HBV is replicating and in mice whose livers have been repopulated with human hepatocytes and infected with HBV. Administration of IFN-α resulted in cccDNA-bound histone hypoacetylation as well as active recruitment to the cccDNA of transcriptional corepressors. IFN-α treatment also reduced binding of the STAT1 and STAT2 transcription factors to active cccDNA. The inhibitory activity of IFN-α was linked to the IRSE, as IRSE-mutant HBV transcribed less pgRNA and could not be repressed by IFN-α treatment. Our results identify a molecular mechanism whereby IFN-α mediates epigenetic repression of HBV cccDNA transcriptional activity, which may assist in the development of novel effective therapeutics.
- Published
- 2011
29. hSirT1-Dependent Regulation of the PCAF-E2F1-p73 Apoptotic Pathway in Response to DNA Damage▿
- Author
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Maurizio Fanciulli, Tiziana Bruno, Francesca Guerrieri, V. Schinzari, Natalia Pediconi, C. Scisciani, Stefania Vossio, Massimo Levrero, and Laura Belloni
- Subjects
Transcription, Genetic ,DNA damage ,Apoptosis ,P300-CBP Transcription Factors ,Biology ,Sirtuin 1 ,E2F1 ,Humans ,Sirtuins ,p300-CBP Transcription Factors ,Promoter Regions, Genetic ,Molecular Biology ,Tumor Suppressor Proteins ,Nuclear Proteins ,Acetylation ,Tumor Protein p73 ,Cell Biology ,Articles ,DNA-Binding Proteins ,E2F1 Transcription Factor ,Gene Expression Regulation ,DNA Damage ,Molecular biology ,PCAF ,biology.protein ,NAD+ kinase ,Histone deacetylase ,Deacetylase activity - Abstract
The NAD(+)-dependent histone deacetylase hSirT1 regulates cell survival and stress responses by inhibiting p53-, NF-kappaB-, and E2F1-dependent transcription. Here we show that the hSirT1/PCAF interaction controls the E2F1/p73 apoptotic pathway. hSirT1 represses E2F1-dependent P1p73 promoter activity in untreated cells and inhibits its activation in response to DNA damage. hSirT1, PCAF, and E2F1 are corecruited in vivo on theP1p73 promoter. hSirT1 deacetylates PCAF in vitro and modulates PCAF acetylation in vivo. In cells exposed to apoptotic DNA damage, nuclear NAD(+) levels decrease and inactivate hSirT1 without altering the hSirT1 interaction with PCAF and hSirT1 binding to the P1p73 promoter. The reactivation of hSirT1 by pyruvate that increases the [NAD(+)]/[NADH] ratio completely abolished the DNA damage-induced activation of TAp73 expression, thus linking the modulation of chromatin-bound hSirT1 deacetylase activity by the intracellular redox state with P1p73 promoter activity. The release of PCAF from hSirT1 repression favors the assembly of transcriptionally active PCAF/E2F1 complexes onto the P1p73 promoter and p53-independent apoptosis. Our results identify hSirT1 and PCAF as potential targets to modulate tumor cell survival and chemoresistance irrespective of p53 status.
- Published
- 2009
30. Metformin targets a new EZH2-phosphoSTAT3-miRNAs pathway to inhibit lipid droplets accumulation and intracellular inflammation
- Author
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Massimo Levrero, Laura Belloni, Vincenzo Barnaba, S. Di Cocco, Silvia Piconese, Natalia Pediconi, and Debora Salerno
- Subjects
Hepatology ,business.industry ,EZH2 ,Gastroenterology ,Inflammation ,Metformin ,Biochemistry ,Lipid droplet ,microRNA ,Medicine ,medicine.symptom ,business ,Intracellular ,medicine.drug - Published
- 2015
31. Hepatitis B Virus Replication Is Regulated by the Acetylation Status of Hepatitis B Virus cccDNA-Bound H3 and H4 Histones
- Author
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Giuseppina Raffa, Teresa Pollicino, Giovanni Raimondo, Giovanni Squadrito, Massimo Levrero, Laura Belloni, and Natalia Pediconi
- Subjects
Adult ,Male ,Hepatitis B virus ,HBV CCCDNA MINICHROMOSOME ,Virus Replication ,medicine.disease_cause ,Hepatitis B virus PRE beta ,Histones ,Hepatitis B, Chronic ,CHROMATIN IMMUNOPRECIPITATION CHIP ASSAY ,HBV COVALENTLY CLOSED CIRCULA CCC DNA ,HBV CCCDNA BOUND H3 AND H4 HISTONES ,CLASS I/II HISTONE DEACETYLASE INHIBITORS ,medicine ,Humans ,Viremia ,Enzyme Inhibitors ,Aged ,Transcriptionally active chromatin ,Hepatology ,biology ,Gastroenterology ,virus diseases ,Acetylation ,cccDNA ,Middle Aged ,Virology ,digestive system diseases ,Histone Deacetylase Inhibitors ,Trichostatin A ,Histone ,Viral replication ,DNA, Viral ,biology.protein ,Female ,DNA, Circular ,Chromatin immunoprecipitation ,medicine.drug - Abstract
Background & Aims: HBV covalently closed circular DNA (cccDNA), the replicative intermediate responsible for persistent HBV infection of hepatocytes, is the template for transcription of all viral mRNAs. Nuclear cccDNA accumulates as a stable episome organized into minichromosomes by histone and nonhistone proteins. In this study we investigated, by a newly developed sensitive and specific assay, the relationship between viral replication and HBV chromatin assembly, transcription, and interaction with viral and cellular regulatory proteins. Methods: To achieve this aim we coupled a quantitative chromatin immunoprecipitation (ChIP) technique to an established method that allows the amplification of virion-encapsidated HBV genomes after transfection of linear HBV DNA into human hepatoma HuH7 cells. The cccDNA–ChIP technique was also applied to study HBV minichromosome transcriptional regulation in liver tissue from HBV-infected patients. Results: The use of anti–acetyl-H4/-H3 specific antibodies to immunoprecipitate transcriptionally active chromatin revealed that HBV replication is regulated by the acetylation status of the cccDNA-bound H3/H4 histones. Class I histone deacetylases inhibitors induced an evident increase of both cccDNA-bound acetylated H4 and HBV replication. Finally, histones hypoacetylation and histone deacetylase 1 recruitment onto the cccDNA in liver tissue correlated with low HBV viremia in hepatitis B patients. Conclusions: We developed a ChIP-based assay to analyze, in vitro and ex vivo, the transcriptional regulation of HBV cccDNA minichromosome. Our results provide new insights on the regulation of HBV replication and identify the enzymatic activities that modulate the acetylation of cccDNA-bound histones as new therapeutic targets for anti-HBV drugs.
- Published
- 2006
32. Differential regulation of E2F1 apoptotic target genes in response to DNA damage
- Author
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Laura Belloni, Alessandra Ianari, Natalia Pediconi, Antonio Porcellini, Edoardo Alesse, Massimo Levrero, Isabella Screpanti, Rita Gallo, Letizia Cimino, Alberto Gulino, Clara Balsano, Antonio Costanzo, Pediconi, N, Ianari, A, Costanzo, A, Belloni, L, Gallo, R, Cimino, L, Porcellini, Antonio, Screpanti, L, Balsano, C, Alesse, E, Gulino, A, and Levrero, M.
- Subjects
Messenger ,Apoptosis ,Cell Cycle Proteins ,Histones ,Genes, Reporter ,Tumor Cells, Cultured ,E2F1 ,Tumor Protein p73 ,Genes, Tumor Suppressor ,Promoter Regions, Genetic ,Etoposide ,Settore MED/35 - Malattie Cutanee e Veneree ,Cultured ,Nuclear Proteins ,E2F1 Transcription Factor ,Acetylation ,Chromatin ,Cell biology ,Tumor Cells ,DNA-Binding Proteins ,biological phenomena, cell phenomena, and immunity ,E2F Transcription Factors ,Tumor Suppressor ,Transcriptional Activation ,endocrine system ,DNA damage ,Biology ,Promoter Regions ,Genetic ,DNA Damage ,Humans ,Doxorubicin ,Tumor Suppressor Proteins ,Fibroblasts ,Gene Deletion ,RNA, Messenger ,Transcription Factors ,Gene Expression Regulation ,E2F ,Transcription factor ,Reporter ,Cell Biology ,Genes ,Cancer research ,RNA ,Chromatin immunoprecipitation - Abstract
E2F1, a member of the E2F family of transcription factors, in addition to its established proliferative effect, has also been implicated in the induction of apoptosis through p53-dependent and p53-independent pathways. Several genes involved in the activation or execution of the apoptotic programme have recently been shown to be upregulated at the transcriptional level by E2F1 overexpression, including the genes encoding INK4a/ARF, Apaf-1, caspase 7 and p73 (refs 3-5). E2F1 is stabilized in response to DNA damage but it has not been established how this translates into the activation of specific subsets of E2F target genes. Here, we applied a chromatin immunoprecipitation approach to show that, in response to DNA damage, E2F1 is directed from cell cycle progression to apoptotic E2F target genes. We identify p73 as an important E2F1 apoptotic target gene in DNA damage response and we show that acetylation is required for E2F1 recruitment on the P1p73 promoter and for its transcriptional activation.
- Published
- 2003
33. Epigenetic drugs targeting cccDNA-bound chromatin modifying enzymes silence HBV transcription and inhibit viral replication
- Author
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S. Valente, Natalia Pediconi, Massimo Levrero, D. Rotili, Antonello Mai, Laura Belloni, and G.A. Palumbo
- Subjects
Genetics ,Hepatology ,Viral replication ,Transcription (biology) ,business.industry ,Chromatin modifying enzymes ,Gastroenterology ,Medicine ,cccDNA ,Epigenetics ,business - Published
- 2014
34. Epigenetic changes associated with the induction of vesicular steatosis in an in vitro cellular model
- Author
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S. Di Cocco, Natalia Pediconi, Debora Salerno, Laura Belloni, Vincenzo Barnaba, Massimo Levrero, and Silvia Piconese
- Subjects
Hepatology ,business.industry ,Immunology ,Gastroenterology ,Medicine ,Epigenetics ,Steatosis ,Cellular model ,business ,medicine.disease ,In vitro ,Cell biology - Published
- 2014
35. Polycomb protein enhancer of Zeste Homolog 2 (EZH2) protects human hepatocellular carcinoma (HCC) cells from DNA damage response (DDR) associated apoptosis
- Author
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Laura Belloni, Debora Salerno, Natalia Pediconi, Massimo Levrero, and S. Jeddari
- Subjects
Hepatology ,business.industry ,Apoptosis ,DNA damage ,Hepatocellular carcinoma ,EZH2 ,Gastroenterology ,Cancer research ,Medicine ,business ,medicine.disease ,Molecular biology - Published
- 2014
36. DN-p73 is activated after DNA damage in a p53-dependent manner to regulate p53-induced cell cycle arrest
- Author
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Massimo Levrero, Natalia Pediconi, Stefania Vossio, Francesca Moretti, E. Palescandolo, Clara Balsano, and Antonio Costanzo
- Subjects
p53 ,Transcriptional Activation ,Cancer Research ,Cell cycle checkpoint ,Tumor suppressor gene ,oncogenes ,tumor suppressor ,DNA damage ,p73 ,Cell ,Apoptosis ,Biology ,apoptosis ,cell cycle ,Cell Line ,Transactivation ,Genetics ,medicine ,Tumor Cells, Cultured ,Humans ,Genes, Tumor Suppressor ,RNA, Messenger ,skin and connective tissue diseases ,Promoter Regions, Genetic ,neoplasms ,Molecular Biology ,Tumor Suppressor Proteins ,Cell Cycle ,Nuclear Proteins ,Tumor Protein p73 ,Cell cycle ,Fibroblasts ,Molecular biology ,Up-Regulation ,DNA-Binding Proteins ,medicine.anatomical_structure ,Doxorubicin ,Tumor Suppressor Protein p53 ,Chromatin immunoprecipitation ,DNA Damage - Abstract
p53 and p73 genes are both activated in response to DNA damage to induce either cell cycle arrest or apoptosis, depending on the strength and the quality of the damaging stimulus. p53/p73 transcriptional activity must be tightly regulated to ensure that the appropriate biological response is achieved and to allow the cell to re-enter into the cell cycle after the damage has been repaired. In addition to multiple transcriptionally active (TA) isoforms, dominant negative (DN) variants, that lack the amino-terminal transactivation domain and function as trans-repressors of p53, p63 and p73, are expressed from a second internal promoter (P2-p73Pr). Here we show that, in response to a non apoptotic DNA damage induced by low doses of doxorubicin, p53 binds in vivo, as detected by a p53-specific chromatin immunoprecipitation assay, and activates the P2-p73 promoter. DN-p73alpha protein accumulates under the same conditions and exogenously expressed DN-p73alpha is able to counteract the p53-induced activation of the P2-p73Pr. These results suggest that DN-p73 may contribute to the autoregulatory loops responsible for the termination of p53/p73 responses in cells that do not undergo apoptosis. Accordingly, the activation of the P2-p73Pr is markedly enhanced in both p73-/- murine fibroblasts and in human cells in which p73 transcripts are selectively knocked-out by p73-specific small interfering RNAs.
- Published
- 2001
37. Epigenetic sylencing and transcriptional regulation of miRNAs modulated in human HCCs
- Author
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Massimo Levrero, Stefania Vossio, Natalia Pediconi, C. Scisciani, R. De Iaco, and V. Schinzari
- Subjects
Hepatology ,business.industry ,microRNA ,Gastroenterology ,Cancer research ,Transcriptional regulation ,Medicine ,Epigenetics ,HCCS ,business - Published
- 2009
38. The hSIRT1 hystone deacetylase regulates TAp73 transcription and apoptosis in response to DNA damage IN HCC cells
- Author
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Francesca Guerrieri, Natalia Pediconi, Stefania Vossio, Laura Belloni, and Massimo Levrero
- Subjects
Hepatology ,Transcription (biology) ,Apoptosis ,DNA damage ,DNA repair ,business.industry ,Gastroenterology ,Medicine ,business ,Cell biology - Published
- 2007
39. 56 SUPPRESSION OF HEPATITIS B VIRUS (HBV) TRANSCRIPTION AND REPLICATION BY SMALL MOLECULES THAT TARGET THE EPIGENETIC CONTROL OF NUCLEAR cccDNA MINICHROMOSOME
- Author
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D. Rotili, S. Valente, Natalia Pediconi, G.A. Palumbo, Massimo Levrero, A. Mai, and Laura Belloni
- Subjects
Hepatology ,business.industry ,medicine.medical_treatment ,cccDNA ,TLR8 ,Liver transplantation ,Virology ,Hepatitis B virus PRE beta ,Minichromosome ,Immunity ,Transcription (biology) ,Medicine ,Epigenetics ,business - Abstract
55 SELECTIVE ACTIVATION OF INTRAHEPATIC IMMUNITY WITH TLR8 AGONIST: A POTENT THERAPEUTIC STRATEGY TO BOOST ANTIVIRAL IMMUNITY IN HUMAN LIVER J. Jo, X.-Z. Tang, A.T. Tan, E. Sandalova, A. Chia, K.C. Tan, K.H. Lee, A.J. Gehring, A. Bertoletti. Singapore Institute for Clinical Sciences, A*STAR Singapore, Asian Unit for Liver Transplantation, Gleneagles Hospital, Program Emerging Viral Diseases Unit, Duke-NUS Graduate Medical School, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore E-mail: juandy_jo@sics.a-star.edu.sg
- Published
- 2013
40. 129 IDENTIFICATION OF HBx TARGET miRNAs THAT REGULATE HBV REPLICATION BY ChIP-Seq
- Author
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Anna Tramontano, L. Le Pera, Laura Belloni, Daniel D'Andrea, Massimo Levrero, Francesca Guerrieri, and Natalia Pediconi
- Subjects
HBx ,Hepatology ,microRNA ,Identification (biology) ,Computational biology ,Biology ,Hbv replication ,Virology - Published
- 2013
41. 1283 MC2791, A SPECIFIC Sirt1 AGONIST DRUG, DECREASES LIPIDS AND REACTIVE OXYGEN SPECIES ACCUMULATION IN AN IN VITRO MODEL OF STEATOSIS IN DIFFERENTIATED HepaRG CELLS
- Author
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A. Mai, S. Di Cocco, Silvia Piconese, S. Valente, D. Rotili, Natalia Pediconi, Massimo Levrero, and Vincenzo Barnaba
- Subjects
Drug ,Agonist ,chemistry.chemical_classification ,Reactive oxygen species ,Hepatology ,medicine.drug_class ,Chemistry ,media_common.quotation_subject ,medicine.disease ,Molecular biology ,In vitro model ,Biochemistry ,medicine ,Steatosis ,media_common - Abstract
1283 MC2791, A SPECIFIC Sirt1 AGONIST DRUG, DECREASES LIPIDS AND REACTIVE OXYGEN SPECIES ACCUMULATION IN AN IN VITRO MODEL OF STEATOSIS IN DIFFERENTIATED HepaRG CELLS N. Pediconi, S. Piconese, S. Valente, S. Di Cocco, D. Rotili, V. Barnaba, A. Mai, M. Levrero. Dip. di Medicina Interna (DMISM), Life Nanosciences Laboratory, EAL Inserm U 785, Dip. di Chimica e Tecnologie del Farmaco, Sapienza University, Rome, Italy E-mail: natalia.pediconi@gmail.com
- Published
- 2013
42. OC-22 Suppression of HBV transcription and replication by small molecules that target the epigenetic control of nuclear cccDNA minichromosome
- Author
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G.A. Palumbo, Laura Belloni, Massimo Levrero, D. Rotili, S. Valente, Antonello Mai, and Natalia Pediconi
- Subjects
Hepatology ,Minichromosome ,business.industry ,Transcription (biology) ,Gastroenterology ,Medicine ,cccDNA ,Epigenetics ,business ,Small molecule ,Molecular biology ,Cell biology - Published
- 2013
43. T-25 MC2791, a specific class III HDAC Sirt1 agonist drug, decreases lipids and reactive oxygen species accumulation in an in vitro model of steatosis in differentiated HepaRG cells
- Author
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Antonello Mai, S. Valente, S. Di Cocco, Natalia Pediconi, Vincenzo Barnaba, Silvia Piconese, D. Rotili, and Massimo Levrero
- Subjects
Agonist ,chemistry.chemical_classification ,Drug ,Reactive oxygen species ,Hepatology ,medicine.drug_class ,media_common.quotation_subject ,Gastroenterology ,Class iii ,Biology ,medicine.disease ,In vitro model ,chemistry ,Biochemistry ,medicine ,Steatosis ,media_common - Published
- 2013
44. 443 HBX-INDUCED REPRESSION OF MIR224 EXPRESSION RELIEVES THE DIRECT INHIBITORY EFFECTS OF MIR224 ON HBV PGRNA TO POTENTIATE HBV REPLICATION
- Author
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Francesca Guerrieri, A. Sbardellati, Natalia Pediconi, C. Scisciani, Laura Belloni, Anna Tramontano, and Massimo Levrero
- Subjects
HBx ,Hepatology ,Biology ,Inhibitory postsynaptic potential ,Hbv replication ,Psychological repression ,Cell biology - Published
- 2012
45. 41 IL6, IL6-INDUCED MIRNAS AND HNF1A/HNF4A AND THE EPIGENETIC CONTROL OF CCCDNA TRANSCRIPTION
- Author
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Ulrike Protzer, Massimo Levrero, Francesca Guerrieri, Natalia Pediconi, C. Scisciani, Stefan Rose-John, Julie Lucifora, A. Palumbo, and Laura Belloni
- Subjects
Hepatology ,Transcription (biology) ,microRNA ,cccDNA ,Epigenetics ,Biology ,HNF1A ,Cell biology - Published
- 2012
46. OC-9 IL6, IL6-induced miRNAs and HNF1α/HNF4α in the epigenetic control of cccDNA transcription
- Author
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Ulrike Protzer, Massimo Levrero, Natalia Pediconi, C. Scisciani, Francesca Guerrieri, Julie Lucifora, Laura Belloni, and Stefan Rose-John
- Subjects
Hepatology ,business.industry ,Transcription (biology) ,microRNA ,Gastroenterology ,Medicine ,cccDNA ,Epigenetics ,business ,Cell biology - Published
- 2012
47. The Anti-apoptotic and pro-proliferative p53-related DN-p73 protein is expressed in human HCC
- Author
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Massimo Levrero, Paola Merlo, Natalia Pediconi, Marcella Fulco, Stefania Vossio, Cristiana Almerighi, Elisabetta Cariani, E. Palescandolo, Antonio Costanzo, and Clara Balsano
- Subjects
Hepatology ,Apoptosis ,Cancer research - Published
- 2002
48. CS7.3 cccDNA function and HBV replication
- Author
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Massimo Levrero, Francesca Guerrieri, Laura Belloni, and Natalia Pediconi
- Subjects
Microbiology (medical) ,Infectious Diseases ,General Medicine ,cccDNA ,Biology ,Hbv replication ,Virology ,Function (biology) - Published
- 2011
49. 1121 MIR-224 IS A DIRECT TARGET OF HBX AND MODULATES HBV REPLICATION
- Author
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Natalia Pediconi, Francesca Guerrieri, Laura Belloni, C. Scisciani, and Massimo Levrero
- Subjects
HBx ,Histone ,Methyltransferase ,Hepatology ,biology ,microRNA ,biology.protein ,Cancer research ,Transcriptional regulation ,HCCS ,Transcription factor ,digestive system diseases ,Chromatin remodeling - Abstract
Background: miR224 is frequently up-regulated in human HCCs, peri-tumoral cirrhotic tissues and cirrhotic livers without HCCs. We have recently shown that miR224 expression in the liver is induced by the NFkB-dependent inflammatory pathways (i.e. LTa, and TNFa) that are activated in a large proportion of chronic viral hepatitis, cirrhosis and HCC patients. Differently from other HCCrelated miRNAs that are over-expressed in several other cancers and are considered as bona fide onco-miRs (i.e. miR-21, miR-221, miR-222), miR-224 is apparently more HCC specific, suggesting a possible role of miR224 in liver physiopathology and/or chronic hepatitis infection before HCC development. Aim: To characterize the transcriptional regulation of miR224 by HBx and its effects on HBV replication. Methods: In vivo recruitment of HBx, transcription factors and chromatin remodeling enzymes was analyzed in ChIP-Seq and conventional ChIP experiments. miR224(pr) luciferase reporter constructs were generated and used to assess the ability of HBx to modulate miR224 expression. Endogenous miR224 expression and the impact of miR224 on HBV replication were assessed in HBV replicating HepG2 cells. Results: In a genome wide search of HBx cellular targets by ChIP-Seq we found that HBx protein binds in vivo to the miR224 regulatory region. HBx binding is accompanied by the co-recruitment of p65/NFkB, a loss of Pol II occupancy, the recruitment of the DNMT3a methyltransferase and reduced H4 histone acetylation. Accordingly, miR224 levels were reduced in HBV replicating cells and HBx repressed the miR224(pr) in luciferase reporter assays. pre-miR224 overexpression resulted in reduced HBV pgRNA levels and a 50% reduction in HBV replication. In silico analysis revealed the presence of several miR224 seed sequences on the HBV genome that were conserved across HBV genotypes, suggesting a direct effect of miR224 on the HBV pgRNA. Conclusions: Our results identify a functional regulatory loop between HBx, miR224 and HBV replication where HBx repression of miR224 expression relieves the negative effects of miR224 on HBV replication. These results are compatible with the low HBV replication observed in HCC tissues and support the hypothesis that the loss of the described regulatory loop might occur at the time of transformation or HCC progression.
- Published
- 2011
50. OC-14 miR-224 is a direct target of HBx and modulates HBV replication
- Author
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Francesca Guerrieri, Natalia Pediconi, C. Scisciani, Laura Belloni, and Massimo Levrero
- Subjects
HBx ,Hepatology ,business.industry ,Gastroenterology ,Medicine ,business ,Hbv replication ,Virology - Published
- 2011
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