163 research outputs found

    Polipéptido quimérico fibrina-filagrina citrulinado capaz de detectar los anticuerpos generados en la artritis reumatoide

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    Peer reviewedConsejo Superior de Investigaciones Científicas, Fundació Clinic per a la Recerca BiomédicaT3 Traducción de patente europe

    Interaction of synthetic peptides corresponding to hepatitis G virus (HGV/GBV-C) E2 structural protein with phospholipid vesicles

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    11 pages, 7 figures, 2 tables.-- PMID: 15885095 [PubMed].-- Printed version published May 2005.The interaction with phospholipid bilayers of two synthetic peptides with sequences corresponding to a segment next to the native N-terminus and an internal region of the E2 structural hepatitis G virus (HGV/GBV-C) protein [E2(7–26) and E2(279–298), respectively] has been characterized. Both peptides are water soluble but associate spontaneously with bilayers, showing higher affinity for anionic than zwitterionic membranes. However, whereas the E2(7–26) peptide is hardly transferred at all from water to the membrane interface, the E2(279–298) peptide is able to penetrate into negatively charged bilayers remaining close to the lipid/water interface. The nonpolar environment clearly induces a structural transition in the E2(279–298) peptide from random coil to α-helix, which causes bilayer perturbations leading to vesicle permeabilization. The results indicate that this internal segment peptide sequence is involved in the fusion of HGV/GBV-C to membrane.This work was funded by grants BQU2003-05070-CO2-01/02 from the Ministerio de Ciencia y Tecnología (Spain) and a predoctoral grant awarded to C. L.Peer reviewe

    Conjugation of cell-penetrating peptides with poly(Lactic-co-glycolic acid)-polyethylene glycol nanoparticles improves ocular drug delivery

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    In this work, a peptide for ocular delivery (POD) and human immunodeficiency virus transactivator were conjugated with biodegradable poly(lactic-co-glycolic acid) (PGLA)- polyethylene glycol (PEG)-nanoparticles (NPs) in an attempt to improve ocular drug bioavail- ability. The NPs were prepared by the solvent displacement method following two different pathways. One involved preparation of PLGA NPs followed by PEG and peptide conjugation (PLGA-NPs-PEG-peptide); the other involved self-assembly of PLGA-PEG and the PLGA-PEG- peptide copolymer followed by NP formulation. The conjugation of the PEG and the peptide was confrmed by a colorimetric test and proton nuclear magnetic resonance spectroscopy. Flur- biprofen was used as an example of an anti-inflammatory drug. The physicochemical properties of the resulting NPs (morphology, in vitro release, cell viability, and ocular tolerance) were studied. In vivo anti-inflammatory effcacy was assessed in rabbit eyes after topical instillation of sodium arachidonate. Of the formulations developed, the PLGA-PEG-POD NPs were the smaller particles and exhibited greater entrapment effciency and more sustained release. The positive charge on the surface of these NPs, due to the conjugation with the positively charged peptide, facilitated penetration into the corneal epithelium, resulting in more effective preven- tion of ocular inflammation. The in vitro toxicity of the NPs developed was very low; no ocular irritation in vitro (hen’s egg test-chorioallantoic membrane assay) or in vivo (Draize test) was detected. Taken together, these data demonstrate that PLGA-PEG-POD NPs are promising vehicles for ocular drug delivery.This work was supported by the Cooperation Research Program CSIC-CITMA and a project (MAT2011-26994) funded by the Spanish Ministry of Science and Technology. AV is a recipient of a PhD grant from the CSIC. The authors thank Nacho Pérez of the IQAC-CSIC for performing the cytotoxicity assays.Peer reviewe

    Development of Peptide Targeted PLGA-PEGylated Nanoparticles Loading Licochalcone-A for Ocular Inflammation

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    Licochalcone-A is a natural compound with anti-inflammatory properties. However, it possesses low water solubility, making its application for the treatment of ocular inflammation difficult. To overcome this drawback, biodegradable nanoparticles incorporating Licochalcone-A have been developed. Additionally, to avoid fast clearance and increase cellular internalization into the ocular tissues, PLGA nanoparticles have been functionalized using PEG and cell penetrating peptides (Tet-1 and B6). To optimize the formulations, a factorial design was carried out and short-term stability of the nanoparticles was studied. Moreover, morphology was also observed by transmission electron microcopy and in vitro drug release was carried out. Ocular tolerance of the formulations was ensured in vitro and in vivo and anti-inflammatory therapeutic efficacy was also assessed. Surface functionalized nanoparticles loading Licochalcone-A were developed with an average size below 200 nm, a positive surface charge, and a monodisperse population. The formulations were non-irritant and showed a prolonged Licochalcone-A release. Despite the fact that both Licochalcone-A Tet-1 and B6 functionalized nanoparticles demonstrated to be suitable for the treatment of ocular inflammation, B6 targeted nanoparticles provided greater therapeutic efficacy in in vivo assays. Keywords: Licochalcone-A; nanoparticles; ocular inflammation; cell-penetrating peptides; PLG

    Guiding the humoral response against HIV-1 toward a MPER adjacent region by immunization with a VLP-formulated antibody-selected envelope variant

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    Preventive HIV-1 vaccine strategies rely on the elicitation of broadly neutralizing antibody (bNAb) responses, but their induction in vivo by vaccination remains challenging. Considering that the ability of an epitope to elicit effective humoral immunity depends on its exposure on the virion, we have used a reverse genetics approach to select variants from an HIV-1 AC10_29 randomly mutated envelope library that showed increased affinity for a selected bNAb (4E10 bNAb targeting the HIV-1 MPER region). Isolated envelope sequences were analyzed by deep-sequencing showing a small number of dominant changes, including the loss of four potential N-linked glycosylation sites and disruption of the V1/V2 loop. Accordingly, the dominant variant (LR1-C1), showed not only increased affinity for MPER bNAbs 4E10 and 2F5, but also higher affinity for an additional antibody targeting the V3 loop (447-52D) that could be a consequence of an open conformation tier 1-like Env. Furthermore, the amino acids specific for the selected variant are associated with an increased sensitivity for 4E10 and 2F5 antibodies. In vivo studies showed that sera from mice immunized with LR1-C1 viruses possessed an improved neutralizing activity compared to the wild-type AC10_29 env. While Virus Like Particles (VLPs) carrying this envelope were unable to induce detectable neutralizing activity in immunized rabbits, one animal showed antibody response to the 4E10-proximal region. Our data establish a novel approach that has the potential to yield HIV envelope immunogen sequences that direct antibody responses to specific envelope regions

    Big dynorphin is a neuroprotector scaffold against amyloid β-peptide aggregation and cell toxicity

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    Amyloid β-peptide (Aβ) misfolding into β-sheet structures triggers neurotoxicity inducing Alzheimer's disease (AD). Molecules able to reduce or to impair Aβ aggregation are highly relevant as possible AD treatments since they should protect against Aβ neurotoxicity. We have studied the effects of the interaction of dynorphins, a family of opioid neuropeptides, with Aβ40 the most abundant species of Aβ. Biophysical measurements indicate that Aβ40 interacts with Big Dynorphin (BigDyn), lowering the amount of hydrophobic aggregates, and slowing down the aggregation kinetics. As expected, we found that BigDyn protects against Aβ40 aggregates when studied in human neuroblastoma cells by cell survival assays. The cross-interaction between BigDyn and Aβ40 provides insight into the mechanism of amyloid pathophysiology and may open up new therapy possibilities.The authors would like to thank Mr. Jordi Pujols Pujol for skillful technical assistance in RP-HPLC experiments, and Mr. Mateo Calle Velásquez for skillful assistance in the docking process.Peer reviewe

    Assessment of anti-malondialdehyde-acetaldehyde antibody frequencies in rheumatoid arthritis with new data from two independent cohorts, meta-analysis, and meta-regression

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    Autoantibodies are critical elements in RA pathogenesis and clinical assessment. The anti-malondialdehyde-acetaldehyde (anti-MAA) antibodies are potentially useful because of their claimed high sensitivity for all RA patients, including those lacking RF and anti-CCP antibodies. Therefore, we aimed to replicate these findings.The research done in Santiago was funded by Instituto de Salud Carlos III through the projects PI20/01268, PI17/01606 and RD21/0002/0003, co-funded by the European Union. L.R.-M. was supported by Xunta de Galicia (Spain) through a Gain pre-doctoral fellowship (IN606A-2017/015). The research in Barcelona was funded by the Spanish Ministry of Economy, Industry and Competitiveness and the European Regional Development Fund (Grant PID2021-122216OB-I00).Peer reviewe

    Hyperoxemia and excess oxygen use in early acute respiratory distress syndrome : Insights from the LUNG SAFE study

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    Publisher Copyright: © 2020 The Author(s). Copyright: Copyright 2020 Elsevier B.V., All rights reserved.Background: Concerns exist regarding the prevalence and impact of unnecessary oxygen use in patients with acute respiratory distress syndrome (ARDS). We examined this issue in patients with ARDS enrolled in the Large observational study to UNderstand the Global impact of Severe Acute respiratory FailurE (LUNG SAFE) study. Methods: In this secondary analysis of the LUNG SAFE study, we wished to determine the prevalence and the outcomes associated with hyperoxemia on day 1, sustained hyperoxemia, and excessive oxygen use in patients with early ARDS. Patients who fulfilled criteria of ARDS on day 1 and day 2 of acute hypoxemic respiratory failure were categorized based on the presence of hyperoxemia (PaO2 > 100 mmHg) on day 1, sustained (i.e., present on day 1 and day 2) hyperoxemia, or excessive oxygen use (FIO2 ≥ 0.60 during hyperoxemia). Results: Of 2005 patients that met the inclusion criteria, 131 (6.5%) were hypoxemic (PaO2 < 55 mmHg), 607 (30%) had hyperoxemia on day 1, and 250 (12%) had sustained hyperoxemia. Excess FIO2 use occurred in 400 (66%) out of 607 patients with hyperoxemia. Excess FIO2 use decreased from day 1 to day 2 of ARDS, with most hyperoxemic patients on day 2 receiving relatively low FIO2. Multivariate analyses found no independent relationship between day 1 hyperoxemia, sustained hyperoxemia, or excess FIO2 use and adverse clinical outcomes. Mortality was 42% in patients with excess FIO2 use, compared to 39% in a propensity-matched sample of normoxemic (PaO2 55-100 mmHg) patients (P = 0.47). Conclusions: Hyperoxemia and excess oxygen use are both prevalent in early ARDS but are most often non-sustained. No relationship was found between hyperoxemia or excessive oxygen use and patient outcome in this cohort. Trial registration: LUNG-SAFE is registered with ClinicalTrials.gov, NCT02010073publishersversionPeer reviewe
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