65 research outputs found
Coronary Intimal Thickening Begins in Fetuses and Progresses in Pediatric Population and Adolescents to Atherosclerosis
The prevalence of coronary intimal thickening (IT) was assessed in fetuses and pediatric population. We studied the coronary arteries of 63 hearts obtained from fetuses, infants, children, and adolescents, deceased from noncardiac disease or trauma. Histomorphometric analysis, planimetry, and immunohistochemical studies were conducted. Intimal thickening consisted of proliferation of smooth muscle cells and scarce monocytes embedded in amorphous deposits within the internal elastic membrane (IEM). Intermingled lesions of intimal hyperplasia and parietal nonstenotic plaques were also observed. Intimal thickening was found in 10% of 20 fetuses, in 33.3% of 18 infants, 73.3% of 15 children, and 100% of 10 adolescents. A significant correlation (r = 0.671, P < 0.001) was found between the extent of IT and age. The IEM was duplicated or interrupted in 43% of patients, showing a positive correlation with the degree of IT (P = 0.01). Intimal thickening was predominantly found near bifurcation sites in the left anterior descending coronary artery (55.6%) and in zones free of bifurcation in the right coronary artery (75%). In conclusion, the prevalence and extension of IT lesions are higher at older ages within a young population. Intimal thickening may be regarded as the first event occurring in coronary preatherosclerosis, preceding lipid deposition.Fil: Guerri Guttenberg, Roberto Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Cardiológicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Cardiológicas; ArgentinaFil: Castilla, Rocio Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Cardiológicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Cardiológicas; ArgentinaFil: Cao, Gabriel Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Cardiológicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Cardiológicas; ArgentinaFil: Azzato, Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Cardiológicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Cardiológicas; ArgentinaFil: Ambrosio, Giuseppe. Università di Perugia; ItaliaFil: Milei, Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Cardiológicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Cardiológicas; Argentin
Surface X-ray Diffraction Study of a Bi-Layer Junction Based on Cu and Cd Sulfides for Photovoltaic Applications
none9noThis study investigates the crystal structure of thin films of chalcogenides, particularly a junction
with a p-type (Cu2S) and an n-type (CdS) layer deposited one on top of the other on a Ag(111)
substrate, starting from an aqueous solution and by means of electrochemical atomic layer
deposition (E-ALD) (the system is denoted by (Cu2S)60/(CdS)60/Ag(111)).mixedTommaso Baroni; Francesco Di Benedetto; Andrea Giaccherini; Enrico Berretti; Francesca Russo; Annalisa Guerri; Massimo Innocenti; Francesco Carlà; Roberto FeliciBaroni, Tommaso; DI BENEDETTO, Francesco; Giaccherini, Andrea; Berretti, Enrico; Russo, Francesca; Guerri, Annalisa; Innocenti, Massimo; Carlà, Francesco; Felici, Robert
Operando SXRD study of the structure and growth process of Cu2S ultra-thin films
International audienceElectrochemical Atomic Layer Deposition (E-ALD) technique has demonstrated to be a suitable process for growing compound semiconductors, by alternating the under-potential deposition (UPD) of the metallic element with the UPD of the non-metallic element. The cycle can be repeated several times to build up films with sub-micrometric thickness. We show that it is possible to grow, by E-ALD, Cu2S ultra-thin films on Ag(111) with high structural quality. They show a well ordered layered crystal structure made on alternating pseudohexagonal layers in lower coordination. As reported in literature for minerals in the Cu-S compositional field, these are based on CuS3 triangular groups, with layers occupied by highly mobile Cu ions. This structural model is closely related to the one of the low chalcocite. The domain size of such films is more than 1000 angstrom in lateral size and extends with a high crystallinity in the vertical growth direction up to more than 10 nm. E-ALD process results in the growth of highly ordered and almost unstrained ultra-thin films. This growth can lead to the design of semiconductors with optimal transport proprieties by an appropriate doping of the intra metallic layer. The present study enables E-ALD as an efficient synthetic route for the growth of semiconducting heterostructures with tailored propertie
Bichromatic laser emission from dipyrromethene dyes incorporated into solid polymeric media
9 pages, 9 figures.Bichromatic laser emission from dipyrromethene-based solid-state dye lasers is reported. The dependence of this dual emission on different factors and its origin and causes are discussed in the light of different models proposed in the literature. Our experimental results indicate that the long-wavelength emission can be explained in terms of reabsorption/reemission effects and inhomogeneous broadening of the S0-S1 transition. The short-wavelength emission corresponds to the usual S0-S1 transition and dominates at low dye concentration.This work was supported by Project Nos. MAT2004-04643-C03-01 and MAT2004-04643-C03-02 of the Spanish CICYT. One of the authors (M.Á.) thanks Ministerio de Ciencia y Tecnología (MCT) for a predoctoral grant. Another author (M.L.) thanks Comunidad Autónoma de Madrid for a postdoctoral grant and MCT for a Juan de la Cierva contract.Peer reviewe
CryoEM structures of the SARS-CoV-2 spike bound to antivirals
(Póster 63)
Background: Single-particle cryoelectron microscopy (cryoEM) has played a key role in the fight against COVID-19. The
molecular mechanisms for the action of some of the currently approved drugs targeting the SARS-CoV-2 RNA-dependent
RNA polymerase, the fast developments of the current available vaccines and antibody therapies are examples of the
impact of the knowledge gained from the cryoEM structures of SARS-CoV-2 proteins in complex with proteins (ACE2 or
antibodies/nanobodies) or small compounds. Our aim is to use this technology to understand structurally how certain
antiviral compounds and proteins targeting the spike may inhibit viral entry.
Methods: 1) Production of wild-type and mutated spike and ACE2 proteins using baculovirus/insect cells. 2) Spike
binding kinetics: protein-protein and protein-small compound interactions measured by BLI Biolayer interferometry
(BLI) and/or microscale Thermophoresis (MST). 3) Buffer optimization for cryoEM grid preparation of spike variants by
thermal shift assays and negative-staining electron microscopy (NSEM). These techniques are also used to adjust the
molar ratio of spike:ACE2 and spike:small-compound complexes. 4) Structural characterization by cryoEM.
Results: At IBV-CSIC we have created a pipeline for the production and characterization of several spike variants and
ACE2 decoys. While this pipeline is described in detail in other oral/poster communications, this communication is
centered around one of the pillars within this pipeline; the structural characterization of possible drug candidates
bound to the SARS-CoV-2 spike by cryoEM. In this way, we have successfully solved structures of the spike bound to:
A) protein inhibitors as ACE2 decoys; B) a small inhibitory compound; C) mixtures of proteins and small-compound
(nanobody-heparan derivative) working cooperatively as inhibitors. These protein/drug candidates were previously
selected based on the results obtained in our interactomics platform, whereas their concentration and the buffer
conditions for cryoEM grids preparation were established based on thermal shift assays and NSEM.
Conclusion: CryoEM is a powerful tool to directly visualize the effect caused by a potential drug on a protein target. In
a short period of time we have developed this technique in our institute to be applied to the SARS-CoV-2 spike protein,
not only to obtain high-resolution structures of SARS- CoV-2 spike variants of concern (see WP4) but also to obtain the
structures of complexes of the spike with various inhibitory compounds of very different nature
Photophysical and laser emission studies of 8-polyphenylene-substituted BODIPY dyes in liquid solution and in solid polymeric matrices
In our search for efficient and photostable laser dyes, four new dyes with the basic structure of the
commercial BODIPY laser dye PM567, with either an 8-diphenylene or an 8-p-triphenylene group,
both substituted at the terminal polyphenylene position with an acetoxymethyl (dyes P2Ar1Ac and
P3Ar1Ac, respectively) or a methacryloyloxymethyl group (dyes P2Ar1MA and P3Ar1MA,
respectively), have been synthesized. The photophysical and lasing properties of the dyes have been
studied both dissolved in liquid solvents (acetoxymethyl dyes) and incorporated into solid polymeric
matrices, in the latter case as solutions (acetoxymethyl dyes) or as copolymers with methyl methacrylate
(methacryloyloxymethyl dyes). In liquid solution, the photophysics of P2Ar1Ac and P3Ar1Ac is
scarcely affected by the number (two or three) of p-phenylene units. Quantum mechanical calculations
reveal that the p-phenylene units in these dyes are twisted ca. 37◦ each other, an that the first
8-p-phenylene group stands nearly perpendicular to the aromatic BODIPY plane, resulting in electronic
decoupling of the two chromophores. P2Ar1Ac exhibits a somewhat lower photodegradation quantum
yield under UV and visible irradiation, if compared with P3Ar1Ac or with PM567, likely because of its
also lower rate constant for the reaction with in situ-generated singlet molecular oxygen. Both
acetoxymethyl dyes emit laser radiation in solution in all the solvents tried, under transversal pumping
at 532 nm. In ethyl acetate, with a dye concentration of 0.80 × 10−3 M, laser efficiencies as high as 80%
have been observed. When the 8-polyphenylene dyes were incorporated into solid poly(methyl
methacrylate) (PMMA) matrices, as solutions or as copolymers, the fluorescence emission increased
with respect to that of the parent PM567 dye dissolved in the same matrix, and lasing efficiencies in the
range 18–31% were obtained, with good photostability. The dye P2Ar1Ac dissolved in PMMA was
found to exhibit the best overall laser behavior, with a good balance between efficiency and
photostability.This work was supported by Project MAT2004-04643-C03-01 of
the Spanish CICYT. M. Liras thanks Comunidad Aut´onoma
de Madrid for a predoctoral scholarship and Ministerio de
Educaci´on y Ciencia for a Juan de la Cierva contract.M. A´ lvarez
thanks Ministerio de Educaci´on y Ciencia for a predoctoral scholarship.
The 8-polyphenylene-substituted boron-dipyrromethene
dyes described in this paper and their utilization in liquid and solidstate
dye lasers are covered by Spanish PatentNo. P200701763 filed
on 25 June 2007.Peer reviewe
Use of an interactomics pipeline to assess the potential of new antivirals against SARS-CoV-2
(Póster 80)
Background: In late 2019 SARS-CoV-2 infection appeared in China, becoming a pandemic in 2020. The scientific
community reacted rapidly, characterizing the viral genome and its encoded proteins, aiming at interfering with viral
spreading with vaccines and antivirals. The receptor binding domain (RBD) of the viral spike (S) protein plays a key role
in cell entry of the virus. It interacts with the cellular receptor for SARS-CoV-2, the membrane-bound human Angiotensin
Converting Ectoenzyme 2 (ACE2). With the goal of monitoring interference with this interaction by potential antiviral
drugs, we have set up at the Institute for Biomedicine of Valencia (IBV-CSIC) an interactomics pipeline targeting the
initial step of viral entry.
Methods: For the production part of the pipeline (pure RBD/Spike variants and soluble ACE2), see parallel poster. These
proteins allowed monitoring of the RBD/Spike-ACE2 interaction in presence or absence of potential inhibitors. Thermal
shift assays (thermofluor) were used for initial detection of compound binding at different ligand/protein ratios
and media conditions (pH, buffers, chaotropic agents). Next, binding affinity and on/off kinetics were characterized
using Biolayer interferometry (BLI), Surface plasmon resonance (SPR), Microscale Thermophoresis (MST) and/or
Isothermal titration calorimetry (ITC). For protein-protein interactions, we mostly used BLI or SPR, whereas for proteinsmall
compound analysis MST was generally best. Protein aggregation-dissociation was monitored by size exclusion
chromatography with multiangle light scattering (SEC-MALS).
Results: Candidates proven by thermal shift assays to bind to RBD/spike protein without affecting the integrity of
these proteins were subjected to quantitative affinity measurements. We successfully demonstrated that BLI, SPR and
MST can be used to follow the interactions between SARS-CoV- 2 proteins and the putative drug candidates, as well
as to monitor the interference with Spike-Ace2 binding of potential drug candidates. While BLI and SPR displayed
reproducible results in the measurement of protein-protein interaction (applied to soluble ACE2 used as a decoy),
they were less suitable for measuring the binding of small molecules. The fact that most small compounds were only
soluble in organic solvents made difficult to obtain a low signal/noise while using BLI, necessary for the assessment
of the binding. We overcame that problem by using MST. After dilution of the compounds to the final experimental
concentrations, the technique could detect a significant binding signal enough to calculate binding parameters. MST
also allowed to measure the degree of interference that each compound was having on RBD/Spike-ACE2 interaction.
The pipeline has been customized and validated with compounds of very different nature provided by different groups
belonging to the PTI and other external laboratories, as well as with different Ace2 decoys designed at the IBV.
Conclusions: The interactomics platform at the IBV has been used to successfully develop two different antiviral
approaches in order to fight COVID-19. It has allowed technical specialization of the staff as well as the development,
in a very short period of time, of two ambitious projects. We have demonstrated that we can perform interactomic
characterization for challenging projects as well as provide information about binding of antivirals to potential new
SARS-CoV-2 variants of concern
Protein traffic is an intracellular target in alcohol toxicity
Eukaryotic cells comprise a set of organelles, surrounded by membranes with a unique composition, which is maintained by a complex synthesis and transport system. Cells also synthesize the proteins destined for secretion. Together, these processes are known as the secretory pathway or exocytosis. In addition, many molecules can be internalized by cells through a process called endocytosis. Chronic and acute alcohol (ethanol) exposure alters the secretion of different essential products, such as hormones, neurotransmitters and others in a variety of cells, including central nervous system cells. This effect could be due to a range of mechanisms, including alcohol-induced alterations in the different steps involved in intracellular transport, such as glycosylation and vesicular transport along cytoskeleton elements. Moreover, alcohol consumption during pregnancy disrupts developmental processes in the central nervous system. No single mechanism has proved sufficient to account for these effects, and multiple factors are likely involved. One such mechanism indicates that ethanol also perturbs protein trafficking. The purpose of this review is to summarize our understanding of how ethanol exposure alters the trafficking of proteins in different cell systems, especially in central nervous system cells (neurons and astrocytes) in adult and developing brains
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