Eventos

Defensa de Tesis Doctoral: “Papel de las vesículas extracelulares en la propagación y mantenimiento de la neuroinflamación inducida por el consumo de alcohol en la adolescencia”

Doctorando: Francesc Ibañez Cabanes
Directoras: Dra. Consuelo Guerri Sirera y Dra. María Pascual Mora

Resumen: El consumo de alcohol en altas cantidades y en un corto período de tiempo, conocido también como consumo en atracón, produce efectos negativos en el sistema nervioso central del adolescente, mediante la activación de una respuesta inflamatoria que puede llegar a producir muerte neuronal y alteraciones a nivel estructural y de comportamiento. Entre los mecanismos que podrían participar en la amplificación de la respuesta neuroinflamatoria se encontrarían un tipo de vesículas extracelulares (VEs), denominadas exosomas. Los exosomas son micropartículas de 30-150 nm de tamaño con un contenido de carácter bioactivo, formado por proteínas, lípidos y ácidos nucleicos, y que cumplen un papel importante en la comunicación intercelular. Por tanto, la hipótesis que planteamos en esta tesis doctoral es que las VEs ejercen un papel en el mantenimiento y propagación de la neuroinflamación causada por el consumo de alcohol en forma de atracón. Para ello, tratamos cultivos primarios de astrocitos de ratones WT y deficientes para la proteína TLR4 con etanol, aislamos sus VEs, las caracterizamos e incubamos neuronas con éstas. Las VEs procedentes de astrocitos WT tratados con etanol eran más cuantiosas y presentaron mayores niveles de proteínas y microARNs relacionados con la inflamación. Las neuronas que fueron incubadas con estas VEs (procedentes de astrocitos WT tratados con etanol) presentaron mayores niveles de marcadores inflamatorios y apoptosis. El incremento observado en la secreción de VEs se debió al efecto conjunto de las enzimas esfingomielinasas junto con las membranas de retículo endoplasmático asociadas a mitocondrias (MAM), siendo éste revertido al inhibirse estos componentes. También se analizaron los perfiles de microARNs presentes en las VEs circulantes en el plasma de adolescentes humanos y de ratón tras una intoxicación etílica aguda (IEA) donde observamos diferencias a nivel de género, presentando las VEs como buenos candidatos a biomarcadores de la neuroinflamación inducida por el alcohol.

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Mechanobiology of the tumour microenvironment driving cancer spreading and immune cells trafficking

Anna Labernadie

Institute for Bioengineering of Catalonia, Parc Científic de Barcelona (PCB) Edifici Clúster c/ Baldiri Reixac 10-12, Barcelona, Spain

The tumor microenvironment (TME) is a complex array of cellular and non-cellular components including cancer associated fibroblasts (CAFs), blood vessels, immune cells and the extracellular matrix (ECM) that tightly interact with cancer cells. Increasing evidence reveals that physical interactions, as importantly as chemical crosstalk, can drive tumour dissemination and immunotherapy resistance.

In the first part of the presentation, we will focus on the role of TME in tumour spreading. Using combined biophysical techniques and molecular tools we demonstrated the existence of force transmission between cancer-associated fibroblasts (CAFs) and cancer cells mediated by a heterophilic junction between E-cadherin expressed by cancer cells and N-cadherin expressed by CAFs. We discovered that this adhesion was mechanically active and enables CAFs to guide collective cell migration and initiate cancer cell invasion. The second part of the talk will focus on the role of the TME in cancer immunotherapy outcomes. I will present our newly designed Micro Immunotherapy Response On-chip (MIRO) model that enables to recapitulate in vivo traits of the stromal barrier and allow to assess immunotherapy efficacy through multiscale approaches. Using a HER2+ breast tumour model we show that the use of MIRO allows to monitor immune infiltration through the stromal barrier and quantify Antibody-Dependent Cellular Cytotoxicity (ADCC) response upon drug treatment. Our study reveals that MIRO could offer a versatile tool to unveil fundamental features of the TME driving immune response, and a promising preclinical tool for precision medicine.

12:00 – 12:30 Paz Boix

Optimization of Accurate Breast Cancer Models for the Advanced Preclinical Evaluation of Polymer Therapeutics Polymer therapeutics-based approaches provide advantage over the “free” form of a given drug, including enhanced passive tumor targeting, altered pharmacokinetics, and specific release of drugs at the tumor site thanks to the use of bioresponsive linkers. In vitro characterization of polymer therapeutics commonly employs traditional two-dimensional (2D) cell culture approaches that fail to fully recapitulate important in vivo tumor characteristics. Therefore, we developed optimized three-dimensional (3D) breast cancer culture systems growing in basement membrane matrix extract as a robust platform for the characterization of novel anti-cancer polymer therapeutics. We first established and optimized patient-derived breast cancer organoid and cell line-derived spheroid cultures and then confirmed the maintenance of breast cancer subtype-defining biomarkers. We next characterized the 2D and 3D models and encountered significant differences in metabolic profiles, the epithelial-to-mesenchymal transition, and the expression of breast cancer biomarkers linked to prognosis. We also compared specific drug release-triggering stimuli such as reactive oxygen species (ROS) and cathepsin B levels between breast cancer subtypes, which revealed that 3D cultures of MCF7, MDA-MB-453, and ZR75 breast cancer cell lines displayed significantly increased ROS levels compared to 2D, while cathepsin B levels tended to decrease in 3D ZR75 cultures when compared to 2D. Finally, we evaluated the internalization and lysosomal colocalization of the polyglutamic acid carrier in breast cancer spheroids and characterized the toxicity of a polymer-based combination conjugate carrying a curcuminoid and endocrine therapy both in 3D culture than in 2D culture, obtaining promising results. Our findings highlight the need to employ 3D culture conditions to generate robust characterization data for polymer therapeutics-based anti-cancer strategies. We now aim to apply our 3D models derived from cell lines and patient samples to evaluate both single-drug and combination polymer therapeutics in the hope that this platform will accelerate clinical translation.

12:30 – 13:00 Paco Ibáñez

Role of Extracellular Vesicles during ethanol induced neuroinflammation in adolescence Current evidence indicates that extracellular vesicles (EVs) participate in intercellular signaling and in the regulation and amplification of neuroinflammation. We have demonstrated that ethanol is able to induce an inflammatory immune response through the toll-like receptor 4 (TLR4) activation. But how ethanol alters EVs physiology is not well understood. In the first part of the study, we evaluated if ethanol, through TLR4 response, could change the release and inflammatory content of astrocyte-derived EVs, and whether these vesicles were capable to communicate with neurons and spread neuroinflammation. Previous results of the lab showed that the female brain is more vulnerable to the inflammatory effects of binge ethanol drinking in adolescence than the male brain, and these differences can be detected in plasma. Since EVs can cross the blood brain barrier and the EV miRNAs are highly stable in peripheral circulation, for the second part of the study we analyzed gender differences in the levels of several inflammatory-related miRNAs in plasma EVs derived from alcohol-intoxicated female and male adolescents and whether these miRNAs of EVs could be used as biomarkers of the neuroinflammation induced by ethanol in adolescence.