TGF-β dependent regulation of oxygen radicals during transdifferentiation of activated hepatic stellate cells to myofibroblastoid cells

BACKGROUND: The activation of hepatic stellate cells (HSCs) plays a pivotal role during liver injury because the resulting myofibroblasts (MFBs) are mainly responsible for connective tissue re-assembly. MFBs represent therefore cellular targets for anti-fibrotic therapy. In this study, we employed activated HSCs, termed M1-4HSCs, whose transdifferentiation to myofibroblastoid cells (named M-HTs) depends on transforming growth factor (TGF)-β. We analyzed the oxidative stress induced by TGF-β and examined cellular defense mechanisms upon transdifferentiation of HSCs to M-HTs. RESULTS: We found reactive oxygen species (ROS) significantly upregulated in M1-4HSCs within 72 hours of TGF-β administration. In contrast, M-HTs harbored lower intracellular ROS content than M1-4HSCs, despite of elevated NADPH oxidase activity. These observations indicated an upregulation of cellular defense mechanisms in order to protect cells from harmful consequences caused by oxidative stress. In line with this hypothesis, superoxide dismutase activation provided the resistance to augmented radical production in M-HTs, and glutathione rather than catalase was responsible for intracellular hydrogen peroxide removal. Finally, the TGF-β/NADPH oxidase mediated ROS production correlated with the upregulation of AP-1 as well as platelet-derived growth factor receptor subunits, which points to important contributions in establishing antioxidant defense. CONCLUSION: The data provide evidence that TGF-β induces NADPH oxidase activity which causes radical production upon the transdifferentiation of activated HSCs to M-HTs. Myofibroblastoid cells are equipped with high levels of superoxide dismutase activity as well as glutathione to counterbalance NADPH oxidase dependent oxidative stress and to avoid cellular damage

TGF-β dependent regulation of oxygen radicals during transdifferentiation of activated hepatic stellate cells to myofibroblastoid cells

Background: The activation of hepatic stellate cells (HSCs) plays a pivotal role during liver injury because the resulting myofibroblasts (MFBs) are mainly responsible for connective tissue re-assembly. MFBs represent therefore cellular targets for anti-fibrotic therapy. In this study, we employed activated HSCs, termed M1-4HSCs, whose transdifferentiation to myofibroblastoid cells (named M-HTs) depends on transforming growth factor (TGF)-β. We analyzed the oxidative stress induced by TGF-β and examined cellular defense mechanisms upon transdifferentiation of HSCs to M-HTs. Results: We found reactive oxygen species (ROS) significantly upregulated in M1-4HSCs within 72 hours of TGF-β administration. In contrast, M-HTs harbored lower intracellular ROS content than M1-4HSCs, despite of elevated NADPH oxidase activity. These observations indicated an upregulation of cellular defense mechanisms in order to protect cells from harmful consequences caused by oxidative stress. In line with this hypothesis, superoxide dismutase activation provided the resistance to augmented radical production in M-HTs, and glutathione rather than catalase was responsible for intracellular hydrogen peroxide removal. Finally, the TGF-β/NADPH oxidase mediated ROS production correlated with the upregulation of AP-1 as well as platelet-derived growth factor receptor subunits, which points to important contributions in establishing antioxidant defense. Conclusion: The data provide evidence that TGF-β induces NADPH oxidase activity which causes radical production upon the transdifferentiation of activated HSCs to M-HTs. Myofibroblastoid cells are equipped with high levels of superoxide dismutase activity as well as glutathione to counterbalance NADPH oxidase dependent oxidative stress and to avoid cellular damage

Defective lysosomal proteolysis and axonal transport are early pathogenic events that worsen with age leading to increased APP metabolism and synaptic Abeta in transgenic APP/PS1 hippocampus

Background: Axonal pathology might constitute one of the earliest manifestations of Alzheimer disease. Axonal dystrophies were observed in Alzheimer’s patients and transgenic models at early ages. These axonal dystrophies could reflect the disruption of axonal transport and the accumulation of multiple vesicles at local points. It has been also proposed that dystrophies might interfere with normal intracellular proteolysis. In this work, we have investigated the progression of the hippocampal pathology and the possible implication in Abeta production in young (6 months) and aged (18 months) PS1(M146L)/APP(751sl) transgenic mice. Results: Our data demonstrated the existence of a progressive, age-dependent, formation of axonal dystrophies, mainly located in contact with congophilic Abeta deposition, which exhibited tau and neurofilament hyperphosphorylation. This progressive pathology was paralleled with decreased expression of the motor proteins kinesin and dynein. Furthermore, we also observed an early decrease in the activity of cathepsins B and D, progressing to a deep inhibition of these lysosomal proteases at late ages. This lysosomal impairment could be responsible for the accumulation of LC3-II and ubiquitinated proteins within axonal dystrophies. We have also investigated the repercussion of these deficiencies on the APP metabolism. Our data demonstrated the existence of an increase in the amyloidogenic pathway, which was reflected by the accumulation of hAPPfl, C99 fragment, intracellular Abeta in parallel with an increase in BACE and gamma-secretase activities. In vitro experiments, using APPswe transfected N2a cells, demonstrated that any imbalance on the proteolytic systems reproduced the in vivo alterations in APP metabolism. Finally, our data also demonstrated that Abeta peptides were preferentially accumulated in isolated synaptosomes. Conclusion: A progressive age-dependent cytoskeletal pathology along with a reduction of lysosomal and, in minor extent, proteasomal activity could be directly implicated in the progressive accumulation of APP derived fragments (and Abeta peptides) in parallel with the increase of BACE-1 and gamma-secretase activities. This retard in the APP metabolism seemed to be directly implicated in the synaptic Abeta accumulation and, in consequence, in the pathology progression between synaptically connected regions

Pregnancy Outcomes and SARS-CoV-2 Infection: The Spanish Obstetric Emergency Group Study

Pregnant women who are infected with SARS-CoV-2 are at an increased risk of adverse perinatal outcomes. With this study, we aimed to better understand the relationship between maternal infection and perinatal outcomes, especially preterm births, and the underlying medical and interventionist factors. This was a prospective observational study carried out in 78 centers (Spanish Obstetric Emergency Group) with a cohort of 1347 SARS-CoV-2 PCR-positive pregnant women registered consecutively between 26 February and 5 November 2020, and a concurrent sample of PCR-negative mothers. The patients' information was collected from their medical records, and the association of SARS-CoV-2 and perinatal outcomes was evaluated by univariable and multivariate analyses. The data from 1347 SARS-CoV-2-positive pregnancies were compared with those from 1607 SARS-CoV-2-negative pregnancies. Differences were observed between both groups in premature rupture of membranes (15.5% vs. 11.1%, p < 0.001); venous thrombotic events (1.5% vs. 0.2%, p < 0.001); and severe pre-eclampsia incidence (40.6 vs. 15.6%, p = 0.001), which could have been overestimated in the infected cohort due to the shared analytical signs between this hypertensive disorder and COVID-19. In addition, more preterm deliveries were observed in infected patients (11.1% vs. 5.8%, p < 0.001) mainly due to an increase in iatrogenic preterm births. The prematurity in SARS-CoV-2-affected pregnancies results from a predisposition to end the pregnancy because of maternal disease (pneumonia and pre-eclampsia, with or without COVID-19 symptoms)

Role of assessing liver fibrosis in management of chronic hepatitis C virus infection

Fibrosis progression is common in hepatitis C. Both host and viral factors influence its natural history. Liver fibrosis is a key predictive factor for advanced disease including endpoints such as liver failure, cirrhosis and hepatocellular carcinoma (HCC). METAVIR fibrosis stages F3–F4 have been considered as the threshold for antiviral therapy. However, this aspect is controversial after the advent of new direct-acting antivirals (DAAs) because they show an excellent efficacy and safety profile. Moreover, in the DAA era, fibrosis stage seems not to be a predictive factor of a sustained virological response (SVR). Viral eradication decreases liver damage by improving the inflammation, as well as by regressing fibrosis irrespective of the treatment regimen. Non-invasive methods are useful in the assessment of liver fibrosis, replacing liver biopsy in clinical practice; but their usefulness for monitoring fibrosis after SVR needs to be demonstrated. Fibrosis regression has been demonstrated after the eradication of hepatitis C virus infection and is associated with a lower risk of hepatic cirrhosis and liver cancer. However, patients showing advanced fibrosis and cirrhosis must be followed-up after SVR, as risks of portal hypertension and HCC remain.Peer reviewe

TGF-β dependent regulation of oxygen radicals during transdifferentiation of activated hepatic stellate cells to myofibroblastoid cells

Background: The activation of hepatic stellate cells (HSCs) plays a pivotal role during liver injury because the resulting myofibroblasts (MFBs) are mainly responsible for connective tissue re-assembly. MFBs represent therefore cellular targets for anti-fibrotic therapy. In this study, we employed activated HSCs, termed M1-4HSCs, whose transdifferentiation to myofibroblastoid cells (named M-HTs) depends on transforming growth factor (TGF)-β. We analyzed the oxidative stress induced by TGF-β and examined cellular defense mechanisms upon transdifferentiation of HSCs to M-HTs. Results: We found reactive oxygen species (ROS) significantly upregulated in M1-4HSCs within 72 hours of TGF-β administration. In contrast, M-HTs harbored lower intracellular ROS content than M1-4HSCs, despite of elevated NADPH oxidase activity. These observations indicated an upregulation of cellular defense mechanisms in order to protect cells from harmful consequences caused by oxidative stress. In line with this hypothesis, superoxide dismutase activation provided the resistance to augmented radical production in M-HTs, and glutathione rather than catalase was responsible for intracellular hydrogen peroxide removal. Finally, the TGF-β/NADPH oxidase mediated ROS production correlated with the upregulation of AP-1 as well as platelet-derived growth factor receptor subunits, which points to important contributions in establishing antioxidant defense. Conclusion: The data provide evidence that TGF-β induces NADPH oxidase activity which causes radical production upon the transdifferentiation of activated HSCs to M-HTs. Myofibroblastoid cells are equipped with high levels of superoxide dismutase activity as well as glutathione to counterbalance NADPH oxidase dependent oxidative stress and to avoid cellular damage

Colocación y seguimiento de cajas nido en el entorno natural de la Facultad de Veterinaria de la UCM, aplicable a una enseñanza teórico-práctica del campo de la Zoología.

El medio natural en la actualidad es desconocido por una gran parte del alumnado, por lo que puede constituir uno de los principales recursos de aprendizaje, permitiendo la observación de los fenómenos naturales y el contacto directo con los seres vivos. La falta de contacto con la naturaleza en general está siendo sustituida por una oferta de realidad virtual. A su vez, se están produciendo cambios globales de forma acelerada en todo el planeta debido a la contaminación, la cual está elevando la temperatura de la Tierra y cambiando el ritmo estacional, lo que se ha traducido en la pérdida de hábitats naturales, la subida del nivel de las aguas y a la desaparición de decenas de especies animales. Con el objetivo de hacer frente a este hecho, y poder aportar nuestro grano de arena al cambio, realizamos este proyecto en el que retamos a nuestro alumnado a mitigar estas repercusiones mediante la colocación y el seguimiento de cajas nido en los alrededores de la Facultad de Veterinaria. Este proyecto se ha ajustado a la Agenda 2030, donde la UNESCO pone de relieve diferentes objetivos sostenibles como fueron “Educación de Calidad”, “Ciudades y Comunidades sostenibles”, y “Vida de Ecosistemas Terrestres”. Con el presente proyecto hemos puesto en contacto directo al alumnado con los fenómenos naturales y la vida silvestre, enseñando y generando comportamientos proambientales, conciencia sobre aspectos de la conservación ambiental y conocimiento científico. Además, ha proporcionado sesiones prácticas, las cuales son una estrategia de enseñanza clave en el Grado de Veterinaria, donde los estudiantes han llevado a cabo procedimientos, y han obtenido habilidades y destrezas específicas relacionadas con las aves insectívoras urbanas Se han colocado 60 cajas nidos en las que se han instalado distintas especies de aves paseriformes. Los estudiantes de Grado en Veterinaria han desempeñado un papel fundamental en la puesta a punto de las cajas nido y en su posterior seguimiento. En las cajas nido colocadas han completado su reproducción durante la primavera y verano de 2023, tres parejas de Herrerillo común y cuatro parejas de Gorrión molinero. Se han obtenido parámetros reproductivos como fecha y tamaño de puesta, fecha de eclosión de los pollos, número de volantones producidos, etc. y se ha procedido a anillar a 45 polluelos. Estos, junto con otros datos de carácter científico, como medidas biométricas, se han incorporado a un fichero de datos para su uso en futuros trabajos científicos que se puedan lleven a cabo. Además, el proyecto ha tenido tal alcance que la Comunidad de Madrid mediante el proyecto Arco Verde ha querido participar activamente. También ha servido para impartir charlas sobre diversidad urbana mediante una ponencia titulada “Cajas nido para reproducción e investigación de aves urbanas”, y para participar en la Feria del Campo mediante la realización de un taller titulado “Aves de nuestro entorno: una mirada al interior del nido.”Sección Deptal. de Fisiología (Veterinaria)Fac. de VeterinariaFALSEsubmitte