7-Keto-Cholesterol and Cholestan-3beta, 5alpha, 6beta-Triol Induce Eryptosis through Distinct Pathways Leading to NADPH Oxidase and Nitric Oxide Synthase Activation

BACKGROUND/AIMS: We showed that patho-physiological concentrations of either 7-keto-cholesterol (7-KC), or cholestane-3beta, 5alpha, 6beta-triol (TRIOL) caused the eryptotic death of human red blood cells (RBC), strictly dependent on the early production of reactive oxygen species (ROS). The goal of the current study was to assess the contribution of the erythrocyte ROS-generating enzymes, NADPH oxidase (RBC-NOX), nitric oxide synthase (RBC-NOS) and xanthine oxido-reductase (XOR) to the oxysterol-dependent eryptosis and pertinent activation pathways. METHODS: Phosphatidylserine exposure at the cell surface was estimated from annexin-V-binding, reactive oxygen/nitrogen species (RONS) and nitric oxide formation from 2',7'-dichloro-dihydrofluorescein (DCF-DA) and 4-amino-5-methylamino-2',7'-difluorofluorescein diacetate (DAF-FM DA) -dependent fluorescence, respectively; Akt1, phospho-NOS3 Ser1177, and PKCζ from Western blot analysis. The activity of individual 7-KC (7 μM) and TRIOL (2, μM) on ROS-generating enzymes and relevant activation pathways was assayed in the presence of Diphenylene iodonium chloride (DPI), N-nitro-L-arginine methyl ester (L-NAME), allopurinol, NSC23766 and LY294002, inhibitors in this order of RBC-NOX, RBC-NOS, XOR and upstream regulatory proteins Rac GTPase and phosphoinositide3 Kinase (PI3K); hemoglobin oxidation from spectrophotometric analysis. RESULTS: RBC-NOX was the target of 7-KC, through a signaling including Rac GTPase and PKCζ, whereas TRIOL caused activation of RBC-NOS according to the pathway PI3K/Akt, with the concurrent activity of a Rac-GTPase. In concomitance with the TRIOL-induced .NO production, formation of methemoglobin with global loss of heme were observed, ascribable to nitrosative stress. XOR, activated after modification of the redox environment by either RBC-NOX or RBC-NOS activity, concurred to the overall oxidative/nitrosative stress by either oxysterols. When 7-KC and TRIOL were combined, they acted independently and their effect on ROS/RONS production and PS exposure appeared the result of the effects of the oxysterols on RBC-NOX and RBC-NOS. CONCLUSION: Eryptosis of human RBCs may be caused by either 7-KC or TRIOL by oxidative/nitrosative stress through distinct signaling cascades activating RBC-NOX and RBC-NOS, respectively, with the complementary activity of XOR; when combined, the oxysterols act independently and both concur to the final eryptotic effect

The microcalcification influence on the ateroma plaque vulnerability

Rupture of atherosclerotic plaque, which is related to maximal stress conditions in the plaque, isa major cause of mortality worldwide. More careful examination of stress distributions inplaques reveals that it may be caused by the local stress behaviors caused by cap thinning,inflammation, macroscopic heterogeneity, and recently, the presence of microcalcifications, atcritical sites. However, the role of microcalcifications is not yet fully understood and most finiteelement models of blood vessels with atheroma plaque do not consider the heterogeneity of theplaque constituents at the micro-scale. The goal of the present work is to investigate the effectsof microcalcifications on the stress field of an atheroma plaque vessel section. This is achievedby performing a parametric finite element study, assuming a plane strain hypothesis, of anidealized coronary artery cross-section with eccentric atheroma plaque and onemicrocalcification incorporated. The model was extruded at a small length in order to introducesome purely 3D parameters such as the fiber orientation. Healthy (adventitia) and diseased(fibrotic, lipidic and calcification) tissues were considered. The parametric analysis includes themost influential geometric parameter on atheroma vulnerability and the position and dimensionsof the microcalcification: the fibrous cap thickness, the microcalcification ratio, angle andeccentricity. In total, a large set of 108 different geometries were studied. We could concludethat microcalcifications should be considered in the modeling of this kind of problems sincethey cause a significant alteration of the vulnerable risk by increasing the maximum maximalprincipal stress up to 40%

A parametric model for analysing atherosclerotic arteries: On the FSI coupling

There are many evidences that coronary plaque is not only dependent on the formation and progression of atherosclerosis, but also on the vascular remodelling response. If the local wall shear stress is low, a proliferative plaque may develop. Local inflammatory response will stimulate the formation of a plaque prone to rupture with superimposed thrombus formation (vulnerable plaque). Furthermore, the role of the wall shear stress in the genesis and the development of atherosclerotic diseases has been recently intensively investigated, examining its relationship with the presence of lesions and the intima media thickness. Due to the important role of pulsating blood flow, pressure and hemodynamics factors in atheroma growth, a Fluid Structure Interaction (FSI) parametric study of a 3D atherosclerotic artery has been carried out, with aim of studying the main geometrical risk factors in terms of plaque vulnerability

Remoción química como nueva alternativa a la remoción mecánica para el estudio del polen transportado en las escopas de abejas silvestres

255-262Taxonomic recognition and quantification of the different pollen types collected by bees offer the most direct method to study the diet. To determine the importance of each plant taxon, it is necessary to separate the pollen deposited only in the collecting structures in order to minimize contamination of grains collected passively in other parts of the body. The technique currently applied is based on the mechanical removal of the pollen loads with dissecting needles and repeated washings with ethanol. Metathoracic scopae that underwent this procedure showed traces of pollen in varying amounts when observed under the microscope. As an alternative to this technique chemical removal using HOK is proposed. The leg is removed and treated separatedly to avoid contamination. The deflocculant properties of HOK successfully allowed to separate the pollen adhered to the scopae, which can be then returned to the individual, unaffected by the procedure. Suspend the pollen in a know quantity of mounting fluid permit take the subsamples and determine the total number of pollen grains of each taxon. In this paper, the new technique is presented and its effectiveness is compared to the technique currenty used

Remoción química como nueva alternativa a la remoción mecánica para el estudio del polen transportado en las escopas de abejas silvestres

255-262Taxonomic recognition and quantification of the different pollen types collected by bees offer the most direct method to study the diet. To determine the importance of each plant taxon, it is necessary to separate the pollen deposited only in the collecting structures in order to minimize contamination of grains collected passively in other parts of the body. The technique currently applied is based on the mechanical removal of the pollen loads with dissecting needles and repeated washings with ethanol. Metathoracic scopae that underwent this procedure showed traces of pollen in varying amounts when observed under the microscope. As an alternative to this technique chemical removal using HOK is proposed. The leg is removed and treated separatedly to avoid contamination. The deflocculant properties of HOK successfully allowed to separate the pollen adhered to the scopae, which can be then returned to the individual, unaffected by the procedure. Suspend the pollen in a know quantity of mounting fluid permit take the subsamples and determine the total number of pollen grains of each taxon. In this paper, the new technique is presented and its effectiveness is compared to the technique currenty used

Methodology to calibrate the dissection properties of aorta layers from two sets of experimental measurements

Aortic dissection is a prevalent cardiovascular pathology that can have a fatal outcome. However, the mechanisms that trigger this disease and the mechanics of its progression are not fully understood. Computational models can help understand these issues, but they need a proper characterisation of the tissues. Therefore, we propose a methodology to obtain the dissection parameters of all layers in aortic tissue via the computational modelling of two different delamination tests: the peel and mixed tests. Both experimental tests have been performed in specimens of porcine aorta, where the intima-media and media-adventitia interfaces, as well as the medial layer, were dissected. These two tests have been modelled using a cohesive zone formulation for the separating interface and a hyperelastic anisotropic material model via an implicit static analysis. The dissection properties of each interface have been calibrated by reproducing the force-displacement curves obtained in the experimental tests. The values of peak and mean force of the experiments were fitted with an error below 10%. With this methodology, we intend to contribute to the development of reliable numerical tools for simulating aortic dissection and aortic aneurysm rupture. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

Anti-Eryptotic Activity of Food-Derived Phytochemicals and Natural Compounds

Human red blood cells (RBCs), senescent or damaged due to particular stress, can be removed by programmed suicidal death, a process called eryptosis. There are various molecular mechanisms underlying eryptosis. The most frequent is the increase in the cytoplasmic concentration of Ca2+ ions, later exposure of erythrocytes to oxidative stress, hyperosmotic shock, ceramide formation, stimulation of caspases, and energy depletion. Phosphatidylserine (PS) exposed by eryptotic RBCs due to interaction with endothelial CXC-Motiv-Chemokin-16/Scavenger-receptor, causes the RBCs to adhere to vascular wall with consequent damage to the microcirculation. Eryptosis can be triggered by various xenobiotics and endogenous molecules, such as high cholesterol levels. The possible diseases associated with eryptosis are various, including anemia, chronic kidney disease, liver failure, diabetes, hypertension, heart failure, thrombosis, obesity, metabolic syndrome, arthritis, and lupus. This review addresses and collates the existing ex vivo and animal studies on the inhibition of eryptosis by food-derived phytochemicals and natural compounds including phenolic compounds (PC), alkaloids, and other substances that could be a therapeutic and/or co-adjuvant option in eryptotic-driven disorders, especially if they are introduced through the diet

Incidence, seasonality and serotypes of rotavirus in Gipuzkoa (Basque Country), Spain. A 14-year study

Over a 14-year period (1984–97) the presence of rotavirus in stool samples from children under 15 years with acute gastroenteritis was studied by enzymoimmunoanalysis. Serotyping (G1–G4) was performed using monoclonal antibodies. A total of 17348 children under 15 were investigated. Rotavirus was detected in 3637 (21·0%) specimens, 74·6% of which were from children younger than 2 years old. G1 and G4 were the most frequent serotypes. In 1991–7, the minimum incidence of rotavirus gastroenteritis in children under 4 years of age was 21·7 cases/1000 children/year. By the age of 5 years, at least 1 out of 11·3 children and probably 1 out of every 5–6 children in this area had experienced an episode of rotavirus gastroenteritis that required medical care. In the 1984–90 period a clear seasonality was not observed but in the second period of the study (1991–7), seasonality was marked, with peak activity in winter

Percepciones del consumidor sobre la carne de caprino en España

Se ha realizado una encuesta a consumidores (n=119) con el fin de conocer la percepción que tenían de la carne de caprino frente a la carne de ovino en función de diversos aspectos relacionados con la intención de compra y la percepción de su calidad. El cuestionario constó de 11 enunciados afirmativos, respondidos hedónicamente mediante una escala categórica de 7 puntos (1: “totalmente en desacuerdo”, 7: “totalmente de acuerdo”). El análisis de las respuestas se realizó mediante frecuencias. Los resultados obtenidos han demostrado, globalmente, una sensibilidad positiva hacia la carne de caprino tanto en parámetros decisivos a la hora de la intención de compra como en parámetros de calidad sensorial de la carne. Esto ha sucedido en contra de lo que podría pensarse dado, en nuestro país, el alto consumo y consideración de calidad que tiene la especie ovina.Comisión Interministerial de Ciencia y Tecnología AGL2005-05777- C02-01/GA