Specific Increase in MDR1 Mediated Drug-Efflux in Human Brain Endothelial Cells following Co-Exposure to HIV-1 and Saquinavir

Persistence of HIV-1 reservoirs within the Central Nervous System (CNS) remains a significant challenge to the efficacy of potent anti-HIV-1 drugs. The primary human Brain Microvascular Endothelial Cells (HBMVEC) constitutes the Blood Brain Barrier (BBB) which interferes with anti-HIV drug delivery into the CNS. The ATP binding cassette (ABC) transporters expressed on HBMVEC can efflux HIV-1 protease inhibitors (HPI), enabling the persistence of HIV-1 in CNS. Constitutive low level expression of several ABC-transporters, such as MDR1 (a.k.a. P-gp) and MRPs are documented in HBMVEC. Although it is recognized that inflammatory cytokines and exposure to xenobiotic drug substrates (e.g HPI) can augment the expression of these transporters, it is not known whether concomitant exposure to virus and anti-retroviral drugs can increase drug-efflux functions in HBMVEC. Our in vitro studies showed that exposure of HBMVEC to HIV-1 significantly up-regulates both MDR1 gene expression and protein levels; however, no significant increases in either MRP-1 or MRP-2 were observed. Furthermore, calcein-AM dye-efflux assays using HBMVEC showed that, compared to virus exposure alone, the MDR1 mediated drug-efflux function was significantly induced following concomitant exposure to both HIV-1 and saquinavir (SQV). This increase in MDR1 mediated drug-efflux was further substantiated via increased intracellular retention of radiolabeled [3H-] SQV. The crucial role of MDR1 in 3H-SQV efflux from HBMVEC was further confirmed by using both a MDR1 specific blocker (PSC-833) and MDR1 specific siRNAs. Therefore, MDR1 specific drug-efflux function increases in HBMVEC following co-exposure to HIV-1 and SQV which can reduce the penetration of HPIs into the infected brain reservoirs of HIV-1. A targeted suppression of MDR1 in the BBB may thus provide a novel strategy to suppress residual viral replication in the CNS, by augmenting the therapeutic efficacy of HAART drugs

The habit of finger-licking: getting a solution out of the pandemic

The habit of finger-licking is an insanitary habit observed everywhere including hospital wards and other medical facilities, among providers and other staff members. It is an enduring habit that has been present before and during the pandemic and will continue unless serious notice of it is taken. Herein, we illustrate the risks imposed by this everyday habit on individuals practicing it and on surrounding people, we describe the challenges with prior attempts to defeat this habit, and we explain how the face mask can eliminate this ever-lasting habit

Les codes de la ville (Cultures, langues et formes d'expression urbaines): Cultures, langues et formes d'expression urbaines

Les codes de la ville questionnent la ville en tant qu'espace public et discursif par excellence où s'articulent la production des lieux collectifs de communication et les expressions des différentes formes de représentations sociolinguistiques, sémiotiques et discursives. Qu'ont de particulièrement urbain les phénomènes de contacts et les mélanges de langues ; les interférences, les hybridations et synthèses tant linguistiques que culturelles ? Les réponses sont données au travers d'études et réflexions sur plusieurs "villes-laboratoires" de France et d'Allemagne

Facteurs de risque d'échec de la méthode médicamenteuse d'interruption volontaire de grossesse jusqu à 49 jours d aménorrhée

LILLE2-BU Santé-Recherche (593502101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Species transfer via topsoil translocation: lessons from two large Mediterranean restoration projects

International audienceRestoration success of species-rich grasslands is often limited by low seed dispersal. To reintroduce target species of local provenances, bulk topsoil transfer is performed by excavating soil and vegetation from donor sites and spreading these on receptor sites. Our first objective was to determine the most advantageous season for transferring topsoil in Mediterranean grasslands. The second objective was to assess which treatmentcombination of season (spring or autumn) and transfer ratio (1:1 or 1:3)-performed best in restoring a Mediterranean grassland through bulk topsoil transfer after two large restoration projects. Just-in-time soil transfer (i.e. with no stockpiling) was implemented: (1) on a former 3ha orchard where topsoil was spread after removing trees and leveling soil; and (2) after a 5ha oil pipeline leak where polluted soil was removed prior to treatment (soil horizons were reconstituted). A seed bank study showed that the summer seed bank contained higher seed densities, species richness, and similarity to the reference site than the spring seed bank. Spring transfers gave better results than autumn transfers in terms of species richness and composition similarity with the reference site, while transfer ratios gave similar results. Long-term success was not driven by season or transfer ratio but by the underlying seed bank at receptor sites: the former orchard's weed-containing seed bank hampered topsoil transfer success. This study also suggests that restoration success cannot be deduced from seed bank studies alone, as species establishment is highly dependent on differences in growing conditions (including competition at receptor sites)

Effect of HIV-1 exposure on MDR1 gene expression and efflux function in HBMVEC.

<p>(<b>A</b>) MDR-1, MRP-1 and MRP-2 gene expression following exposure to HIV-1 (0.2 and 1.0 MOI) within 6 hrs post exposure was monitored by qRT-PCR. Data obtained in each sample was normalized to GAPDH mRNA levels (internal control). Fold change in ABC-transporter gene expression with respect to that observed with MDR1 in untreated cells (1.0) was calculated under each treatment condition and for each transporter. Data represent three independent experiments (n = 3) where standard deviation (error bars) were calculated from triplicate samples and significant differences from controls are shown (*, p<0.05 and ** p<0.01). (<b>B</b>) MDR1 efflux function following exposure to HIV-1 (0.2 and 1.0 MOI) for 24 hrs. Verapamil and MK-571 were used as MDR1 and MRPs blocker, respectively. Intracellular fluorescence was normalized to total protein content in cell lysates and change in calcein-AM retention is shown in the bar graphs (*, p<0.05). (<b>C</b>) Comparative effects of conditioned medium (CM) from HIV-1-infected or PMA-stimulated HuT-78 T-cells on MDR1 gene expression. The RT-PCR products from HBMVEC control (1); Hut-78 CM (2); CM from HuT-78 cells treated with PMA (3); or CM from virus producing HTLV-IIIB cells (4), are shown. (<b>D</b>) Effect of live HIV-1 (HTLV-IIIB CM) and heat inactivated HIV-1 (HTLV-IIIB CM-HI) on MDR1 gene expression. The respective fold change in MDR1 gene expression was calculated with respect to GAPDH (internal control). A representative data from three independent experiments, is shown.</p

Localization of MDR-1 (P-gp) protein in HIV-1 and SQV coexposed HBMVEC.

<p>A representative immunofluorescence microscopy data of MDR-1 protein in HBMVEC following exposure to HIV-1 or SQV for 24 hrs is shown. Green punctate MDR-1 staining appeared in (<b>A</b>) untreated cells, (<b>B</b>) cells exposed to SQV (1 µM), (<b>C</b>) cells exposed to HIV-1 (0.2 MOI) only, and (<b>D</b>) combined exposure of SQV and HIV-1. DAPI (blue) staining of the nucleus and WGA (red) staining of cell plasma membrane are also shown. Image Magnification: 630X, scale bar: 21 µm.</p