Morpho-Functional Architecture of the Golgi Complex of Neuroendocrine Cells

In neuroendocrine cells, prohormones move from the endoplasmic reticulum to the Golgi complex (GC), where they are sorted and packed into secretory granules. The GC is considered the central station of the secretory pathway of proteins and lipids en route to their final destination. In most mammalian cells, it is formed by several stacks of cisternae connected by tubules, forming a continuous ribbon. This organelle shows an extraordinary structural and functional complexity, which is exacerbated by the fact that its architecture is cell type specific and also tuned by the functional status of the cell. It is, indeed, one the most beautiful cellular organelles and, for that reason, perhaps the most extensively photographed by electron microscopists. In recent decades, an exhaustive dissection of the molecular machinery involved in membrane traffic and other Golgi functions has been carried out. Concomitantly, detailed morphological studies have been performed, including 3D analysis by electron tomography, and the precise location of key proteins has been identified by immunoelectron microscopy. Despite all this effort, some basic aspects of Golgi functioning remain unsolved. For instance, the mode of intra-Golgi transport is not known, and two opposing theories (vesicular transport and cisternal maturation models) have polarized the field for many years. Neither of these theories explains all the experimental data so that new theories and combinations thereof have recently been proposed. Moreover, the specific role of the small vesicles and tubules which surround the stacks needs to be clarified. In this review, we summarize our current knowledge of the Golgi architecture in relation with its function and the mechanisms of intra-Golgi transport. Within the same framework, the characteristics of the GC of neuroendocrine cells are analyzed

Cutting edge: Regulation of exosome secretion by the integral MAL protein in T cells

Exosomes secreted by T cells play an important role in coordinating the immune response. HIV-1 Nef hijacks the route of exosome secretion of T cells to modulate the functioning of uninfected cells. Despite the importance of the process, the protein machinery involved in exosome biogenesis is yet to be identified. In this study, we show that MAL, a tetraspanning membrane protein expressed in human T cells, is present in endosomes that travel toward the plasma membrane for exosome secretion. In the absence of MAL, the release of exosome particles and markers was greatly impaired. This effect was accompanied by protein sorting defects at multivesicular endosomes that divert the exosomal marker CD63 to autophagic vacuoles. Exosome release induced by HIV-1 Nef was also dependent on MAL expression. Therefore,MAL is a critical element of the machinery for exosome secretion andmay constitute a target for modulating exosome secretion by human T cells. The Journal of Immunology, 2015, 195: 810–814.Peer Reviewe

Estímulo del trabajo autónomo en el aprendizaje práctico de la Histología: una experiencia transversal en Ciencias de la salud

El estudio microscópico de tejidos y órganos constituye un aspecto muy importante del aprendizaje de la histología, pero no siempre se dispone de suficientes colecciones de muestras, sobre todo humanas, para que el alumnado pueda disponer de ellas de forma presencial durante las prácticas. Por ello, el portal virtual digital slidebox (DSB) permite al profesorado generar una colección de preparaciones histológicas virtuales, de manera que los estudiantes tienen acceso "online" a estas muestras y pueden visualizarlas a la misma escala que ofrece la observación directa del microscopio óptico, e incluso mayor. Para la realización de cada práctica en sus horas presenciales el alumno dispone previamente de un guión con los objetivos que debe cumplir al realizar la observación de cada preparación histológica. Al final de cada práctica presencial los objetivos son explicados por el alumno, y evaluados por el profesor, realizando una puesta en común. Una vez realizada la práctica, y en horario no presencial, el alumnado tiene la posibilidad de completar este trabajo usando el portal virtual DSB. Con las imágenes digitales captadas el alumno realiza su portafolio de prácticas incorporando dichas imágenes y rotulándolas. Al final del curso se realiza un examen práctico global y la evaluación final del portafolio

The hidden microbial ecosystem in the perennial ice from a Pyrenean ice cave.

Over the last years, perennial ice deposits located within caves have awakened interest as places to study microbial communities since they represent unique cryospheric archives of climate change. Since the beginning of the twentieth century, the temperature has gradually increased, and it is estimated that by the end of this century the increase in average temperature could be around 4.0°C. In this context of global warming the ice deposits of the Pyrenean caves are undergoing a significant regression. Among this type of caves, that on the Cotiella Massif in the Southern Pyrenees is one of the southernmost studied in Europe. These types of caves house microbial communities which have so far been barely explored, and therefore their study is necessary. In this work, the microbial communities of the Pyrenean ice cave A294 were identified using metabarcoding techniques. In addition, research work was carried out to analyze how the age and composition of the ice affect the composition of the bacterial and microeukaryotic populations. Finally, the in vivo effect of climate change on the cellular machinery that allow microorganisms to live with increasing temperatures has been studied using proteomic techniques

Toward a clinical practice guide in pharmacogenomics testing for functional polymorphisms of drug-metabolizing enzymes. Gene/drug pairs and barriers perceived in Spain

The development of clinica lpractice recommendations or guidelines for the clinical use of biomarkers is an issue of great importance withr regard to adverse drug reactions.The poten-tial of pharmacogenomicbiomarkers has been extensively investigated in recent years.However,several barriers to implementing the use of pharmacogenomics testing exist.We conducted a survey among members of the Spanish Societies of Pharmacology and Clinical Pharmacology to obtain information about the perception of such barriers and to compare the perceptions of participants about the relative importance of majorgene/drug pairs.Of 11 potential barriers,the highest importance was attributed to lack of institutional support for pharmacogenomic stesting,and to the issues related to the lack of guidelines.Of the proposed gene/drug pairs the highest importance was assigned to HLA-B/abacavir, UGT1A1/irinotecan, and CYP2D6/tamoxifen.In this perspective article,we compare the relative importance of 29 gene/drugpairs in the Spanish study with that of the same pairs in the American Society for Clinical Pharmacology and Therapeutic sstudy,and we provide suggestions and areas of focus to develop a guide for clinical practice in pharmacogenomics testingThe work in the author’s laboratory is financed by Grants PS09/00943, PS09/00469, RETICS RIRAAF RD07/0064/0016, and CIBERehd from Instituto de Salud CarlosIII,Madrid, Spain, and by Grants GR10068 from Junta de Extremadura, Spain. Financed in part with FEDER funds from the European Unio

Differential association of 4E-BP2-interacting proteins is related to selective delayed neuronal death after ischemia

Cerebral ischemia induces an inhibition of protein synthesis and causes cell death and neuronal deficits. These deleterious effects do not occur in resilient areas of the brain, where protein synthesis is restored. In cellular stress conditions, as brain ischemia, translational repressors named eukaryotic initiation factor (eIF) 4E-binding proteins (4E-BPs) specifically bind to eIF4E and are critical in the translational control. We previously described that 4E-BP2 protein, highly expressed in brain, can be a molecular target for the control of cell death or survival in the reperfusion after ischemia in an animal model of transient cerebral ischemia. Since these previous studies showed that phosphorylation would not be the regulation that controls the binding of 4E-BP2 to eIF4E under ischemic stress, we decided to investigate the differential detection of 4E-BP2-interacting proteins in two brain regions with different vulnerability to ischemia-reperfusion (IR) in this animal model, to discover new potential 4E-BP2 modulators and biomarkers of cerebral ischemia. For this purpose, 4E-BP2 immunoprecipitates from the resistant cortical region and the vulnerable hippocampal cornu ammonis 1 (CA1) region were analyzed by two-dimensional (2-D) fluorescence difference in gel electrophoresis (DIGE), and after a biological variation analysis, 4E-BP2-interacting proteins were identified by matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry. Interestingly, among the 4E-BP2-interacting proteins identified, heat shock 70 kDa protein-8 (HSC70), dihydropyrimidinase-related protein-2 (DRP2), enolase-1, ubiquitin carboxyl-terminal hydrolase isozyme-L1 (UCHL1), adenylate kinase isoenzyme-1 (ADK1), nucleoside diphosphate kinase-A (NDKA), and Rho GDP-dissociation inhibitor-1 (Rho-GDI), were of notable interest, showing significant differences in their association with 4E-BP2 between resistant and vulnerable regions to ischemic stress. Our data contributes to the first characterization of the 4E-BP2 interactome, increasing the knowledge in the molecular basis of the protection and vulnerability of the ischemic regions and opens the way to detect new biomarkers and therapeutic targets for diagnosis and treatment of cerebral ischemia

Sociodemographic and Lifestyle Determinants of Adherence to Current Dietary Recommendations and Diet Quality in Middle-Aged Spanish Premenopausal Women

Background: A healthy diet when approaching menopause could prevent some of the symptoms associated with the climacteric. Few studies examine adherence to current healthy dietary recommendations in middle-aged premenopausal women. Our objective was to analyze the diet quality and the adherence to the Spanish Society of Community Nutrition (SENC) dietary recommendations in middle-aged Spanish premenopausal women, and to identify the associated sociodemographic and lifestyle factors. Methods: This is a cross-sectional study based on 1251 premenopausal women, aged 39-50, who attended to Madrid City Council Medical Diagnostic Center. Women completed an epidemiological and a food frequency questionnaire. Degree of adherence to the SENC recommendations was estimated with a score that evaluated null (0 points) and full (1 point) adherence of each specific recommendation. Associations were explored using an ordinal logistic multivariable regression model. Results: Regarding food groups, the worst adherence was found for sweets, red/processed meat, olive oil and eggs. Most of the participants exceeded the recommended caloric intake from proteins and fats, and practically all of them showed vitamin D intake deficiency. The overall score ranged from 2 to 12 (out of 15), with a median of 6.0 (interquartile range: 5.0-7.0). Former smokers (OR: 1.38; 95%CI: 1.08-1.78), as well as those with higher educational level (ORSSecondary:1.68; 95%CI: 0.97-2.93, ORUniversity:1.82; 95%IC: 1.05-3.14), with two or more children (OR: 1.31; 95%IC: 1.00-1.72), with higher caloric intake (OR>2188.2kcal/day: 8.22; 95%CI: 6.19-10.92) and with greater physical activity (OR≥21METS-h/week: 1.29; 95%CI: 0.95-1.76) showed greater adherence. Conclusions: Almost two-thirds of middle-aged premenopausal participants showed low or moderate compliance with SENC recommendations. Education, smoking, parity, and physical activity were associated with the degree of adherence to these recommendations.This study was funded by the Spanish Ministry of Health (EC11–273) and by the Instituto de Salud Carlos III (PI15CIII/0029). The article presents independent research.S

Preclinical Characterization of Antioxidant Quinolyl Nitrone QN23 as a New Candidate for the Treatment of Ischemic Stroke

Nitrones are encouraging drug candidates for the treatment of oxidative stress-driven diseases such as acute ischemic stroke (AIS). In a previous study, we found a promising quinolylnitrone, QN23, which exerted a neuroprotective effect in neuronal cell cultures subjected to oxygen–glucose deprivation and in experimental models of cerebral ischemia. In this paper, we update the biological and pharmacological characterization of QN23. We describe the suitability of intravenous administration of QN23 to induce neuroprotection in transitory four-vessel occlusion (4VO) and middle cerebral artery occlusion (tMCAO) experimental models of brain ischemia by assessing neuronal death, apoptosis induction, and infarct area, as well as neurofunctional outcomes. QN23 significantly decreased the neuronal death and apoptosis induced by the ischemic episode in a dose-dependent manner and showed a therapeutic effect when administered up to 3 h after post-ischemic reperfusion onset, effects that remained 11 weeks after the ischemic episode. In addition, QN23 significantly reduced infarct volume, thus recovering the motor function in a tMCAO model. Remarkably, we assessed the antioxidant activity of QN23 in vivo using dihydroethidium as a molecular probe for radical species. Finally, we describe QN23 pharmacokinetic parameters. All these results pointing to QN23 as an interesting and promising preclinical candidate for the treatment of AIS.This work was supported by the Instituto de Salud Carlos III and co-financed by the European Development Regional Fund (FEDER) through grants PI18/00255, RD16/0019/0006, and RD21/0006/0019 to J.M. and A.A., and RD16/0019/0008 and RD21/0006/0014 to J.B.S.; the MINECO grant SAF2015-65586-R to J.M.-C.; and the Comunidad de Madrid Neurocentro project B2017/BMD-3760 to D.G.-N

Phosphorylation of Eukaryotic Initiation Factor 4G1 (eIF4G1) at Ser1147 Is Specific for eIF4G1 Bound to eIF4E in Delayed Neuronal Death after Ischemia

Ischemic strokes are caused by a reduction in cerebral blood flow and both the ischemic period and subsequent reperfusion induce brain injury, with different tissue damage depending on the severity of the ischemic insult, its duration, and the particular areas of the brain affected. In those areas vulnerable to cerebral ischemia, the inhibition of protein translation is an essential process of the cellular response leading to delayed neuronal death. In particular, translation initiation is ratelimiting for protein synthesis and the eukaryotic initiation factor (eIF) 4F complex is indispensable for cap-dependent protein translation. In the eIF4F complex, eIF4G is a scaffolding protein that provides docking sites for the assembly of eIF4A and eIF4E, binding to the cap structure of the mRNA and stabilizing all proteins of the complex. The eIF4F complex constituents, eIF4A, eIF4E, and eIF4G, participate in translation regulation by their phosphorylation at specific sites under cellular stress conditions, modulating the activity of the cap-binding complex and protein translation. This work investigates the phosphorylation of eIF4G1 involved in the eIF4E/eIF4G1 association complex, and their regulation in ischemia-reperfusion (IR) as a stress-inducing condition. IR was induced in an animal model of transient cerebral ischemia and the results were studied in the resistant cortical region and in the vulnerable hippocampal CA1 region. The presented data demonstrate the phosphorylation of eIF4G1 at Ser1147, Ser1185, and Ser1231 in both brain regions and in control and ischemic conditions, being the phosphorylation of eIF4G1 at Ser1147 the only one found in the eIF4E/eIF4G association complex from the cap-containing matrix (m7GTP-Sepharose). In addition, our work reveals the specific modulation of the phosphorylation of eIF4G1 at Ser1147 in the vulnerable region, with increased levels and colocalization with eIF4E in response to IR. These findings contribute to elucidate the molecular mechanism of protein translation regulation that underlies in the balance of cell survival/death during pathophysiological stress, such as cerebral ischemia

Patients’ Opinions about Knowing Their Risk for Depression and What to Do about It. The PredictD-Qualitative Study

[Background] The predictD study developed and validated a risk algorithm for predicting the onset of major depression in primary care. We aimed to explore the opinion of patients about knowing their risk for depression and the values and criteria upon which these opinions are based. [Methods] A maximum variation sample of patients was taken, stratified by city, age, gender, immigrant status, socio-economic status and lifetime depression. The study participants were 52 patients belonging to 13 urban health centres in seven different cities around Spain. Seven Focus Groups (FGs) were given held with primary care patients, one for each of the seven participating cities. [Results] The results showed that patients generally welcomed knowing their risk for depression. Furthermore, in light of available evidence several patients proposed potential changes in their lifestyles to prevent depression. Patients generally preferred to ask their General Practitioners (GPs) for advice, though mental health specialists were also mentioned. They suggested that GPs undertake interventions tailored to each patient, from a “patient-centred” approach, with certain communication skills, and giving advice to help patients cope with the knowledge that they are at risk of becoming depressed. [Conclusions] Patients are pleased to be informed about their risk for depression. We detected certain beliefs, attitudes, values, expectations and behaviour among the patients that were potentially useful for future primary prevention programmes on depression.This work was supported by grants from the Andalusian Council of Health [grant reference: 2008/0195][www.juntadeandalucia.es/fundacionprogres​oysalud]; the Department of Health of the Basque Government [grant reference: 2008/111021][www.osakidetza.euskadi.net]; the Spanish Network of Primary Care Research “redIAPP” (RD06/0018), the “Aragón group” (RD06/0018/0020), the “Sant Joan de Deu group” (RD07/0018/0017), “Bizkaya group” (RD07/0018/0018), “Castilla-León group” (RD07/0018/0027) and the “SAMSERAP group” (RD06/0018/0039 and CTS-587) [www.rediapp.org]