Roma Tre University

About: Roma Tre University is a education organization based out in Rome, Lazio, Italy. It is known for research contribution in the topics: Large Hadron Collider & Galaxy. The organization has 4434 authors who have published 15352 publications receiving 374888 citations. The organization is also known as: Universita degli Studi Roma Tre & RomaTre.

Oxidative Stress Induces Persistent Telomeric DNA Damage Responsible for Nuclear Morphology Change in Mammalian Cells

Abstract: One main function of telomeres is to maintain chromosome and genome stability The rate of telomere shortening can be accelerated significantly by chemical and physical environmental agents Reactive oxygen species are a source of oxidative stress and can produce modified bases (mainly 8-oxoG) and single strand breaks anywhere in the genome The high incidence of guanine residues in telomeric DNA sequences makes the telomere a preferred target for oxidative damage Our aim in this work is to evaluate whether chromosome instability induced by oxidative stress is related specifically to telomeric damage We treated human primary fibroblasts (MRC-5) in vitro with hydrogen peroxide (100 and 200 µM) for 1 hr and collected data at several time points To evaluate the persistence of oxidative stress-induced DNA damage up to 24 hrs after treatment, we analysed telomeric and genomic oxidative damage by qPCR and a modified comet assay, respectively The results demonstrate that the genomic damage is completely repaired, while the telomeric oxidative damage persists The analysis of telomere length reveals a significant telomere shortening 48 hrs after treatment, leading us to hypothesise that residual telomere damage could be responsible for the telomere shortening observed Considering the influence of telomere length modulation on genomic stability, we quantified abnormal nuclear morphologies (Nucleoplasmic Bridges, Nuclear Buds and Micronuclei) and observed an increase of chromosome instability in the same time frame as telomere shortening At subsequent times (72 and 96 hrs), we observed a restoration of telomere length and a reduction of chromosome instability, leaving us to conjecture a correlation between telomere shortening/dysfunction and chromosome instability We can conclude that oxidative base damage leads to abnormal nuclear morphologies and that telomere dysfunction is an important contributor to this effect

Exosomes from Human Immunodeficiency Virus Type 1 (HIV-1)-Infected Cells License Quiescent CD4+ T Lymphocytes To Replicate HIV-1 through a Nef- and ADAM17-Dependent Mechanism

Abstract: Resting CD4+ T lymphocytes resist human immunodeficiency virus (HIV) infection Here, we provide evidence that exosomes from HIV-1-infected cells render resting human primary CD4+ T lymphocytes permissive to HIV-1 replication These results were obtained with transwell cocultures of HIV-1-infected cells with quiescent CD4+ T lymphocytes in the presence of inhibitors of exosome release and were confirmed using exosomes purified from supernatants of HIV-1-infected primary CD4+ T lymphocytes We found that the expression of HIV-1 Nef in exosome-producing cells is both necessary and sufficient for cell activation as well as HIV-1 replication in target CD4+ T lymphocytes We also identified a Nef domain important for the effects we observed, ie, the 62EEEE65 acidic cluster domain In addition, we observed that ADAM17, ie, a disintegrin and metalloprotease converting pro-tumor necrosis factor alpha (TNF-α) in its mature form, associates with exosomes from HIV-1-infected cells, and plays a key role in the HIV-1 replication in quiescent CD4+ T lymphocytes Treatment with an inhibitor of ADAM17 abolished both activation and HIV-1 replication in resting CD4+ T lymphocytes TNF-α is the downstream effector of ADAM17 since the treatment of resting lymphocytes with anti-TNF-α antibodies blocked the HIV-1 replication The data presented here are consistent with a model where Nef induces intercellular communication through exosomes to activate bystander quiescent CD4+ T lymphocytes, thus stimulating viral spread IMPORTANCE Overall, our findings support the idea that HIV evolved to usurp the exosome-based intercellular communication network to favor its spread in infected hosts

Subduction, convergence and the mode of backarc extension in the Mediterranean region

Abstract: 30-35 Ma ago a major change occurred in the Mediterranean region, from a regionally compressional subduction coeval with the formation of Alpine mountain belts, to extensional subduction and backarc rifting. Backarc extension was accompanied by gravitational spreading of the mountain belts formed before this Oligocene revolution. Syn-rift basins formed during this process above detachments and low-angle normal faults. Parameters that control the formation and the kinematics of such flat-lying detachments are still poorly understood. From the Aegean Sea to the Tyrrhenian Sea and the Alboran Sea, we have analysed onshore the deformation and P-T-t evolution of the ductile crust exhumed by extension, and the transition from ductile to brittle conditions as well as the relations between deep deformation and basin formation. We show that the sense of shear along crustal-scale detachments is toward the trench when subduction proceeds with little or no convergence (northern Tyrrhenian and Alboran after 20 Ma) and away from the trench in the case of true convergence (Aegean). We tentatively propose a scheme explaining how interactions between the subducting slab and the mantle control the basal shear below the upper plate and the geometry and distribution of detachments and associated sedimentary basins. We propose that ablative subduction below the Aegean is responsible for the observed kinematics on detachments (i.e. away from the trench). The example of the Betic Cordillera and the Rif orogen, where the directions of stretching were different in the lower and the upper crust and changed through time, is also discussed following this hypothesis.

Network Analysis of World Trade using the BACI-CEPII Dataset

Abstract: In this paper we explore the BACI-CEPII database using Network Analysis. From the visualization of the World Trade Network, we define and describe its topology, both in its binary version and in it...

Underwater Optical Wireless Communications: Overview.

Abstract: Underwater Optical Wireless Communication (UOWC) is not a new idea, but it has recently attracted renewed interest since seawater presents a reduced absorption window for blue-green light. Due to its higher bandwidth, underwater optical wireless communications can support higher data rates at low latency levels compared to acoustic and RF counterparts. The paper is aimed at those who want to undertake studies on UOWC. It offers an overview on the current technologies and those potentially available soon. Particular attention has been given to offering a recent bibliography, especially on the use of single-photon receivers.