Ceramide is a Mediator of Apoptosis in Retina Photoreceptors

PURPOSE. The precise mechanisms involved in photoreceptor apoptosis are still unclear. We here investigated the role of ceramide, a sphingolipid precursor that induces apoptosis upon cellular stress, in activating this death in photoreceptors. METHODS. Rat retina neuronal cultures, with or without docosahexaenoic acid (DHA), were treated with the ceramide analog acetylsphingosine (C2-ceramide), and with a glucosylceramide synthase inhibitor. Ceramide synthesis in cultures treated with the oxidant paraquat was evaluated with [3H]palmitate. The effect of inhibitors of ceramide de novo synthesis, fumonisin B1 and cycloserine, on photoreceptor apoptosis was investigated. Apoptosis, mitochondrial membrane potential and Bcl-2 expression were determined. RESULTS. Addition of C2-ceramide induced photoreceptor apoptosis. Paraquat increased formation of [3H]ceramide in photoreceptors, compared to controls, while inhibition of ceramide synthesis, immediately before paraquat treatment, prevented paraquat-induced photoreceptor apoptosis. Fumonisin also reduced photoreceptor apoptosis during early development in vitro. DHA, the retina major polyunsaturated fatty acid, which protects photoreceptors from oxidative stress-induced apoptosis, completely blocked C2-ceramide-induced photoreceptor death, simultaneously increasing Bcl-2 expression. Inhibiting glucosylceramide synthase, which catalyzes ceramide glucosylation, before ceramide or paraquat treatment blocked DHA protective effect. CONCLUSIONS. Our results suggest that oxidative stress stimulated an increase in ceramide levels, which induced photoreceptor apoptosis. DHA prevented oxidative stress and ceramide damage by up regulating Bcl-2 expression and glucosylating ceramide, thus decreasing its intracellular concentration. This shows for the first time that ceramide is a critical mediator for triggering photoreceptor apoptosis in mammalian retina and suggests that modulating ceramide levels might provide a therapeutic tool for preventing photoreceptor death in neurodegenerative diseases.Fil: German, Olga Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; ArgentinaFil: Miranda, Gisela Edit. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; ArgentinaFil: Abrahan, Carolina Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; ArgentinaFil: Rotstein, Nora Patricia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentin

Retina stem cells, hopes and obstacles

Retinal degeneration is a major contributor to visual dysfunction worldwide. Although it comprises several eye diseases, loss of retinal pigment epithelial (RPE) and photoreceptor cells are the major contributors to their pathogenesis. Early therapies included diverse treatments, such as provision of anti-vascular endothelial growth factor and many survival and trophic factors that, in some cases, slow down the progression of the degeneration, but do not effectively prevent it. The finding of stem cells (SC) in the eye has led to the proposal of cell replacement strategies for retina degeneration. Therapies using different types of SC, such as retinal progenitor cells (RPCs), embryonic SC, pluripotent SCs (PSCs), induced PSCs (iPSCs), and mesenchymal stromal cells, capable of self-renewal and of differentiating into multiple cell types, have gained ample support. Numerous preclinical studies have assessed transplantation of SC in animal models, with encouraging results. The aim of this work is to revise the different preclinical and clinical approaches, analyzing the SC type used, their efficacy, safety, cell attachment and integration, absence of tumor formation and immunorejection, in order to establish which were the most relevant and successful. In addition, we examine the questions and concerns still open in the field. The data demonstrate the existence of two main approaches, aimed at replacing either RPE cells or photoreceptors. Emerging evidence suggests that RPCs and iPSC are the best candidates, presenting no ethical concerns and a low risk of immunorejection. Clinical trials have already supported the safety and efficacy of SC treatments. Serious concerns are pending, such as the risk of tumor formation, lack of attachment or integration of transplanted cells into host retinas, immunorejection, cell death, and also ethical. However, the amazing progress in the field in the last few years makes it possible to envisage safe and effective treatments to restore vision loss in a near future.Fil: German, Olga Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; ArgentinaFil: Vallese Maurizi, Harmonie. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; ArgentinaFil: Soto, Tamara Belen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; ArgentinaFil: Rotstein, Nora Patricia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; ArgentinaFil: Politi, Luis Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentin

A Defective Crosstalk Between Neurons and Müller Glial Cells in the rd1 Retina Impairs the Regenerative Potential of Glial Stem Cells

Müller glial cells (MGC) are stem cells in the retina. Although their regenerative capacity is very low in mammals, the use of MGC as stem cells to regenerate photoreceptors (PHRs) during retina degenerations, such as in retinitis pigmentosa, is being intensely studied. Changes affecting PHRs in diseased retinas have been thoroughly investigated; however, whether MGC are also affected is still unclear. We here investigated whether MGC in retinal degeneration 1 (rd1) mouse, an animal model of retinitis pigmentosa, have impaired stem cell properties or structure. rd1 MGC showed an altered morphology, both in culture and in the whole retina. Using mixed neuron-glial cultures obtained from newborn mice retinas, we determined that proliferation was significantly lower in rd1 than in wild type (wt) MGC. Levels of stem cell markers, such as Nestin and Sox2, were also markedly reduced in rd1 MGC compared to wt MGC in neuron-glial cultures and in retina cryosections, even before the onset of PHR degeneration. We then investigated whether neuron-glial crosstalk was involved in these changes. Noteworthy, Nestin expression was restored in rd1 MGC in co-culture with wt neurons. Conversely, Nestin expression decreased in wt MGC in co-culture with rd1 neurons, as occurred in rd1 MGC in rd1 neuron-glial mixed cultures. These results imply that MGC proliferation and stem cell markers are reduced in rd1 retinas and might be restored by their interaction with "healthy" PHRs, suggesting that alterations in rd1 PHRs lead to a disruption in neuron-glial crosstalk affecting the regenerative potential of MGC.Fil: Volonté, Yanel Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; ArgentinaFil: Vallese Maurizi, Harmonie Agostina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; ArgentinaFil: Dibo, Marcos Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; ArgentinaFil: Ayala Peña, Victoria Belen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; ArgentinaFil: Garelli, Andres. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; ArgentinaFil: Zanetti, Samanta Romina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; ArgentinaFil: Turpaud Barrera, Axel Hector Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; ArgentinaFil: Craft, Cheryl Mae. University Of Southern California; Estados UnidosFil: Rotstein, Nora Patricia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; ArgentinaFil: Politi, Luis Enrique. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; ArgentinaFil: German, Olga Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; Argentin

COVID-19 epidemiological surveillance through pool testing focused on asymptomatic healthcare workers in the city of Bahía Blanca

INTRODUCCIÓN: Uno de los desafíos más relevantes al comienzo de la pandemia consistió en implementar estrategias dirigidas a prevenir la transmisión del virus SARS-CoV-2 y mitigar el impacto de la COVID-19. El propósito de este estudio fue contribuir a reducir la transmisión comunitaria a través de una iniciativa interinstitucional, cuyos objetivos fueron validar un método de detección de ARN del SARS-CoV-2 e implementar y evaluar la vigilancia en trabajadores de salud asintomáticos de instituciones de salud pública de Bahía Blanca. MÉTODOS: Se validó una prueba de detección del gen E del coronavirus mediante RT-PCR a partir de ARN aislado de hisopados nasofaríngeos. Para aumentar la capacidad de testeo se validó la detección del ARN viral en muestras agrupadas (pooles). Se realizó un estudio de cohorte prospectiva entre el 15/09/20 y el 15/09/21. RESULTADOS: La sensibilidad y especificidad de la prueba en muestras individuales fue del 95% (IC 95%: 85%-100%). La sensibilidad de la detección en pooles fue del 73% (IC 95%: 46%-99%) y la especificidad, del 100%. A lo largo de la vigilancia se incluyeron 855 trabajadores y 1764 hisopados, con una incidencia acumulada anual de 2,3% (IC 95%: 1,2%-3,4%). Se detectaron 20 casos asintomáticos positivos. DISCUSIÓN: El tamizaje de trabajadores de salud asintomáticos en la pandemia contribuyó a reducir el riesgo de brotes hospitalarios. Asimismo, se generó un marco de trabajo interdisciplinario aplicable a otros problemas de saludINTRODUCTION: One of the most important challenges at the beginning of the pandemic was to implement strategies to prevent SARS-CoV-2 virus transmission and reduce the impact of COVID-19. The purpose of this study was to contribute to the reduction of community transmission through an interinstitutional initiative, aimed at validating a SARS-CoV-2 RNA detection method, and at implementing and assessing the surveillance of asymptomatic infected healthcare workers (HCWs) at public health institutions in the city of Bahía Blanca. METHODS: To validate a coronavirus RNA detection method, RNA was extracted from nasopharyngeal swabs and identification of the viral E gene was done by RT-PCR. Validation of sample pooling was performed to increase the testing capacity. A prospective cohort study was conducted from 15 September 2020 to 15 September 2021. RESULTS: The sensitivity and specificity of the test in individual samples was 95% (CI 95%: 85%-100%). The sensitivity of the pooling strategy was 73% (CI 95%: 46%-99%) and the specificity was 100%. A total of the 855 HCWs were included in the surveillance and 1764 swabs were performed, with an annual cumulative incidence of 2.3% (CI 95%: 1,2%-3,4%), and 20 positive asymptomatic cases were detected. DISCUSSION: The screening of asymptomatic HCWs during the pandemic contributed to reduce the risk of outbreaks in hospital settings. Moreover, an interdisciplinary team framework applicable to other health problems was generated.Fil: Esandi, María del Carmen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; ArgentinaFil: Marinovich, Joel. Hospital Municipal Doctor Leonidas Lucero.; Argentina. Universidad Nacional del Sur; ArgentinaFil: Bergé, Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; ArgentinaFil: García, Nicolás. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Física del Sur. Universidad Nacional del Sur. Departamento de Física. Instituto de Física del Sur; ArgentinaFil: German, Olga Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; ArgentinaFil: Ayala Peña, Victoria Belen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; ArgentinaFil: Sierra, Fermín. Hospital Municipal Doctor Leonidas Lucero.; Argentina. Universidad Nacional del Sur; ArgentinaFil: Serralunga, María Gabriela. Universidad Nacional del Sur. Departamento de Matemática; ArgentinaFil: Esandi, Maria Eugenia. Universidad Nacional del Sur. Departamento de Economía; ArgentinaFil: del Valle, Marta. Hospital Municipal Doctor Leonidas Lucero.; Argentina. Universidad Nacional del Sur; ArgentinaFil: Bouzat, Cecilia Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentin

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)

In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. For example, a key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process versus those that measure fl ux through the autophagy pathway (i.e., the complete process including the amount and rate of cargo sequestered and degraded). In particular, a block in macroautophagy that results in autophagosome accumulation must be differentiated from stimuli that increase autophagic activity, defi ned as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (inmost higher eukaryotes and some protists such as Dictyostelium ) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the fi eld understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. It is worth emphasizing here that lysosomal digestion is a stage of autophagy and evaluating its competence is a crucial part of the evaluation of autophagic flux, or complete autophagy. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. Along these lines, because of the potential for pleiotropic effects due to blocking autophagy through genetic manipulation it is imperative to delete or knock down more than one autophagy-related gene. In addition, some individual Atg proteins, or groups of proteins, are involved in other cellular pathways so not all Atg proteins can be used as a specific marker for an autophagic process. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field

Guía de práctica clínica para la prevención, diagnóstico, tratamiento y rehabilitación de la falla cardiaca en población mayor de 18 años, clasificación B, C y D

La falla cardíaca es un síndrome clínico caracterizado por síntomas y signos típicos de insuficiencia cardíaca, adicional a la evidencia objetiva de una anomalía estructural o funcional del corazón. Guía completa 2016. Guía No. 53Población mayor de 18 añosN/

Retinoid X Receptor´s activation modulates a crosstalk between NrF2 and NFkB pathway in retinal pigment epithelium cells upon H2O2 treatment

Age-related macular degeneration (AMD) is the main pathology leading to blindness in adults and has no cure or effective treatment. Retinal pigment epithelial (RPE) cells have immunomodulatory properties and their degeneration contributes in AMD development. Oxidative stress is also involved in the pathogenesis of this disease. We have demonstrated that RXR activation with HX630 protects RPE (D407) cells from H2O2-induced apoptosis, and prevents NFkB nuclear translocation. Also, our previous results suggested RXR- PPARgamma as the main heterodimer involved. In this work we investigate the RXR-PPARgamma involvement in the mentioned protective effect and its mechanism of action. For that, D407 were treated or not with H2O2, HX630 and/or a PPARgamma specific agonist (Pioglitazone: PG). We analyzed cell viability by MTT assay and DAPI stained; and studied NFkB pathway (which modulates inflammation and apoptosis) and Nrf2 (which activates cytoprotective genes and regulates NFkB pathway) by qRT-PCR, florescence microscopy and Western-blot. PG reproduced the inhibition of NFkB translocation and the protective effect of RXR activation against oxidative damage. PG inhibited the IKBalpha phosphorylation more than HX630, while it promoted IKBalpha synthesis. When HX630 and PG were together, the inhibition of NFkB translocation was higher than the agonists alone, although, there was no synergism in apoptosis prevention. HX630 increases Nrf2 synthesis, PG does not, and both agonists together decrease NrF2 levels suggesting proteosomal degradation. As a whole, our results show that RXR and PPARgamma agonists together potentiate the anti- inflammatory response but not the antiapoptotic effects of each agonist alone on RPE cells upon oxidative stress, and suggest that both agonists are necessary together to alter the crosstalk between NrF2 and NFkB pathway.Fil: Ayala Peña, Victoria Belen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; ArgentinaFil: German, Olga Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; ArgentinaReunión Anual de Sociedades de Biociencia 2019; LXIV Reunión Anual de la Sociedad Argentina de Investigación Clínica (SAIC); LI Reunión Anual de la Asociación Argentina de Farmacología Experimental (SAFE); XXI Reunión Anual de la Sociedad Argentina de Biología (SAB); XXXI Reunión Anual de la Sociedad Argentina de Protozoología (SAP); IX Reunión Anual de la Asociación Argentina de Nanomedicinas (NANOMED-ar); VI Reunión Científica Regional de la Asociación Argentina de Ciencia y Tecnología de Animales de Laboratorio (AACyTAL)mar del plataArgentinaSociedad Argentina de Investigación ClínicaAsociación Argentina de Farmacología ExperimentalSociedad Argentina de BiologíaSociedad Argentina de ProtozoologíaAsociación Argentina de NanomedicinasAsociación Argentina de Ciencia y Tecnología de Animales de LaboratorioThe Histochemical Societ

Analysis of expression and function of voltage-activated potassium KCNQ channels on mouse eye

Neuronal potassium channels KCNQ (Kv7) are important for neuron physiology because they regulate their excitability. Four of the five KCNQ channel genes are mutated in human genetic diseases. There are transgenic mice for KCNQ3, -4 and -5 channels, which we used in previous works, allowing the study of protein function and mutation-associated pathologies. Recent publications showed the expression of KCNQ2 to -5 in primate eye and also a possible link between Kcnq5 gen and refractive errors. For these reasons, we investigate the expression and function of these channels in wild-type, Kcnq4-/- and Kcnq5dn/dn mice. We found a weak labeling of KCNQ4 in retinal pigmented epithelium cells, which is enhanced in pigmented cells of ciliary body. KCNQ3 was found only in cells of the non-pigmented epitehlium of the ciliary body. Opposite to what was reported in other species, no KCNQ channel subunits were found in mouse retina. Besides, immature mouse retinal neurons in culture did not show M-like potassium currents, which are generated by KCNQ channels in neurons. Our results suggest that KCNQ channels may participate in the formation of aquous humor of the eye, providing part of the companion positive current during chloride transport trough the epithelium.Fil: Spitzmaul, Guillermo Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; ArgentinaFil: German, Olga Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; ArgentinaFil: Jentsch, Thomas. Leibniz-Institut fuer Molekulare Pharmakologie; Alemania. MaxDelbrueck-Centrum fuer Molekulare Medizin; AlemaniaXXIX Annual Meeting of Sociedad Argentina de Investigación en NeurocienciasHuerta GrandeArgentinaSociedad Argentina e Investigación en Neurociencia

Tipos de muerte celular

Todos los organismos nacen, crecen, se reproducen y mueren. Este ciclo es indispensable para lograr mantener la continuidad del ADN a través de las sucesivas generaciones. Una vez asegurada la transmisión del material genético a la descendencia, la muerte es un proceso inevitable y necesario. Para los organismos sencillos, la muerte, ya sea por depredación, por condiciones desfavorables del medio o por causas patológicas, es un hecho no querido que representa un obstáculo sustancial a la continuidad de su ADN. En cambio, durante el curso de su vida, los organismos multicelulares requieren que muchas de sus células sean eliminadas para que el organismo en su conjunto tenga éxito en la réplica y transmisión del material genético a la progenie. En éstos, la muerte celular no necesariamente implica la muerte del organismo sino que constituye una manera de contribuir a su supervivencia y reproducción. Por lo tanto, la muerte celular es parte esencial del proceso normal de desarrollo, maduración y remodelación de los organismos multicelulares. La muerte es también una respuesta necesaria del organismo frente a mutaciones en el ADN de sus propias células o a agentes xenobióticos (por ejemplo a microorganismos y a agentes químicos) o situaciones patológicas, en procesos como la inflamación o cuando ocurren alteraciones en el suministro normal de sangre a un tejido.Fil: German, Olga Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; ArgentinaFil: Politi, Luis Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; ArgentinaFil: Rotstein, Nora Patricia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentin