Del laboratorio a la clínica en el ictus isquémico agudo. Modelos experimentales in vitro e in vivo / From the laboratory to the clinic in acute ischaemic stroke. In vitro and in vivo experimental models

Introducción: La enfermedad cerebrovascular es una de las principales causas de muerte, discapacidad y demencia en el mundo. La forma más frecuente de la enfermedad, el ictus isquémico, sólo tiene un fármaco disponible, el activador tisular del plasminógeno, y pocos pacientes pueden beneficiarse de esta terapia por los estrictos criterios de inclusión establecidos para su uso. Esta circunstancia hace crucial la búsqueda de nuevas formas de tratamiento para combatir las secuelas de la enfermedad, y para ello es necesario el desarrollo de nuevos modelos biomiméticos que permitan conocer mejor su evolución. Desarrollo: En esta revisión, actualizamos las plataformas y modelos más utilizados en los últimos años para estudiar la fisiopatología del ictus isquémico. Por un lado, repasamos las plataformas bi- y tridimensionales sobre las que se llevan a cabo los ensayos in vitro y, por otro lado, describimos los modelos experimentales in vivo más utilizados en la actualidad, así como las técnicas para evaluar el daño isquémico. Conclusiones: El desarrollo de buenos modelos experimentales tiene como fin último encontrar nuevas formas de tratamiento y, de esta manera, mejorar el pronóstico y la calidad de vida de los pacientes; por ello, es importante generar nuevos dispositivos in vitro y refinar más aún los modelos in vivo para hacer posible una buena traslación a la clínica.(AU)

Introduction: Cerebrovascular disease is one of the leading causes of death, disability and dementia around the world. For the most common form of the disease, ischaemic stroke, there is only one drug available, tissue plasminogen activator, and few patients can benefit from this therapy because of the strict inclusion criteria established for its use. This circumstance makes it crucial to search for new forms of treatment to combat the sequelae of the disease, and this requires the development of new biomimetic models that allow for a better understanding of its evolution. Development: In this review, we update the platforms and models most widely used in recent years to study the pathophysiology of ischaemic stroke. On the one hand, we review the two- and three-dimensional platforms on which in vitro assays are carried out and, on the other, we describe the most commonly used in vivo experimental models and techniques for assessing ischaemic damage. Conclusions: The ultimate aim of developing good experimental models is to find new forms of treatment and thus improve patients’ prognosis and quality of life. It is therefore important to generate new in vitro devices and to further refine in vivo models to enable a good clinical translation.(AU)

[From the laboratory to the clinic in acute ischaemic stroke. In vitro and in vivo experimental models]. / Del laboratorio a la clínica en el ictus isquémico agudo. Modelos experimentales in vitro e in vivo.

INTRODUCTION: Cerebrovascular disease is one of the leading causes of death, disability and dementia around the world. For the most common form of the disease, ischaemic stroke, there is only one drug available, tissue plasminogen activator, and few patients can benefit from this therapy because of the strict inclusion criteria established for its use. This circumstance makes it crucial to search for new forms of treatment to combat the sequelae of the disease, and this requires the development of new biomimetic models that allow for a better understanding of its evolution. DEVELOPMENT: In this review, we update the platforms and models most widely used in recent years to study the pathophysiology of ischaemic stroke. On the one hand, we review the two- and three-dimensional platforms on which in vitro assays are carried out and, on the other, we describe the most commonly used in vivo experimental models and techniques for assessing ischaemic damage. CONCLUSIONS: The ultimate aim of developing good experimental models is to find new forms of treatment and thus improve patients' prognosis and quality of life. It is therefore important to generate new in vitro devices and to further refine in vivo models to enable a good clinical translation.

TITLE: Del laboratorio a la clínica en el ictus isquémico agudo. Modelos experimentales in vitro e in vivo.Introducción. La enfermedad cerebrovascular es una de las principales causas de muerte, discapacidad y demencia en el mundo. La forma más frecuente de la enfermedad, el ictus isquémico, sólo tiene un fármaco disponible, el activador tisular del plasminógeno, y pocos pacientes pueden beneficiarse de esta terapia por los estrictos criterios de inclusión establecidos para su uso. Esta circunstancia hace crucial la búsqueda de nuevas formas de tratamiento para combatir las secuelas de la enfermedad, y para ello es necesario el desarrollo de nuevos modelos biomiméticos que permitan conocer mejor su evolución. Desarrollo. En esta revisión, actualizamos las plataformas y modelos más utilizados en los últimos años para estudiar la fisiopatología del ictus isquémico. Por un lado, repasamos las plataformas bi- y tridimensionales sobre las que se llevan a cabo los ensayos in vitro y, por otro lado, describimos los modelos experimentales in vivo más utilizados en la actualidad, así como las técnicas para evaluar el daño isquémico. Conclusiones. El desarrollo de buenos modelos experimentales tiene como fin último encontrar nuevas formas de tratamiento y, de esta manera, mejorar el pronóstico y la calidad de vida de los pacientes; por ello, es importante generar nuevos dispositivos in vitro y refinar más aún los modelos in vivo para hacer posible una buena traslación a la clínica.

Specific Features of SVZ Neurogenesis After Cortical Ischemia: a Longitudinal Study.

Stroke is a devastating disease with an increasing prevalence. Part of the current development in stroke therapy is focused in the chronic phase, where neurorepair mechanisms such as neurogenesis, are involved. In the adult brain, one of the regions where neurogenesis takes place is the subventricular zone (SVZ) of the lateral ventricles. Given the possibility to develop pharmacological therapies to stimulate this process, we have performed a longitudinal analysis of neurogenesis in a model of cortical ischemia in mice. Our results show an initial decrease of SVZ proliferation at 24 h, followed by a recovery leading to an increase at 14d and a second decrease 28d after stroke. Coinciding with the 24 h proliferation decrease, an increase in the eutopic neuroblast migration towards the olfactory bulb was observed. The analysis of the neuroblast ectopic migration from the SVZ toward the lesion showed an increase in this process from day 14 after the insult. Finally, our data revealed an increased number of new cortical neurons in the peri-infarct cortex 65d after the insult. In summary, we report here critical check-points about post-stroke neurogenesis after cortical infarcts, important for the pharmacological modulation of this process in stroke patients.

Daidzein has neuroprotective effects through ligand-binding-independent PPARγ activation.

Phytoestrogens are a group of plant-derived compounds that include mainly isoflavones like daidzein. Phytoestrogens prevent neuronal damage and improve outcome in experimental stroke; however, the mechanisms of this neuroprotective action have not been fully elucidated. In this context, it has been postulated that phytoestrogens might activate the peroxisome proliferator-activated receptor-γ (PPARγ), which exerts neuroprotective effects in several settings. The aim of this study was to determine whether the phytoestrogen daidzein elicits beneficial actions in neuronal cells by mechanisms involving activation of PPARγ. Our results show that daidzein (0.05-5 µM) decreases cell death induced by exposure to oxygen-glucose deprivation (OGD) from rat cortical neurons and that improves synaptic function, in terms of increased synaptic vesicle recycling at nerve terminals, being both effects inhibited by the PPARγ antagonist T0070907 (1 µM). In addition, this phytoestrogen activated PPARγ in neuronal cultures, as shown by an increase in PPARγ transcriptional activity. Interestingly, these effects were not due to binding to the receptor ligand site, as shown by a TR-FRET PPARγ competitive binding assay. Conversely, daidzein increased PPARγ nuclear protein levels and decreased cytosolic ones, suggesting nuclear translocation. We have used the receptor antagonist (RE) fulvestrant to study the neuroprotective participation of daidzein via estrogen receptor and at least in our model, we have discarded this pathway. These results demonstrate that the phytoestrogen daidzein has cytoprotective properties in neurons, which are due to an increase in PPARγ activity not mediated by direct binding to the receptor ligand-binding domain but likely due to post-translational modifications affecting its subcellular location and not depending to the RE and it is not additive with the agonist rosiglitazone.