GDF15 and ACE2 stratify COVID-19 patients according to severity while ACE2 mutations increase infection susceptibility

Coronavirus disease 19 (COVID-19) is a persistent global pandemic with a very heterogeneous disease presentation ranging from a mild disease to dismal prognosis. Early detection of sensitivity and severity of COVID-19 is essential for the development of new treatments. In the present study, we measured the levels of circulating growth differentiation factor 15 (GDF15) and angiotensin-converting enzyme 2 (ACE2) in plasma of severity-stratified COVID-19 patients and uninfected control patients and characterized the in vitro effects and cohort frequency of ACE2 SNPs. Our results show that while circulating GDF15 and ACE2 stratify COVID-19 patients according to disease severity, ACE2 missense SNPs constitute a risk factor linked to infection susceptibility

Metabolisme energètic de la cèl·lula tumoral: una posible diana per al tractament del càncer. Paper de la sirtuïna 3

[cat] Resum Les cèl·lules canceroses presenten diverses característiques distintives de les cèl·lules normals, entre les que destaca la reprogramació metabòlica que sofreixen per tal de sostenir la seva elevada taxa de proliferació. Avui en dia es reconeix el paper fonamental que juguen els mitocondris, principals productors d’ATP i d’espècies reactives d’oxigen (ROS), en el desenvolupament i la progressió del càncer. Una proteïna clau implicada en el control de la integritat mitocondrial i de l’estrès oxidatiu és SIRT3, considerada el guardià del mitocondri. Altres proteïnes que poden tenir un paper clau en el metabolisme tumoral són PGC-1α, regulador de la biogènesi mitocondrial; UCP2, implicada en la funció mitocondrial i l’estrès oxidatiu; o p53, regulador de la resposta antioxidant i supervivència cel·lular. Aquestes proteïnes podrien ser possibles dianes per al tractament del càncer. Els objectius d’aquesta tesi van ser els següents: 1) estudiar el paper de SIRT3 sobre l’estrès oxidatiu i l’homeòstasi mitocondrial en línies de càncer de mama i de còlon, i si el seu silenciament pot millorar l’eficàcia dels tractaments antitumorals emprats més freqüentment; 2) analitzar la importància de PGC-1α sobre la resposta a l’estrès oxidatiu i la funcionalitat mitocondrial en línies cel·lulars de melanoma; 3) estudiar si el silenciament d’UCP2 en cèl·lules de càncer de pàncrees pot afectar la funció mitocondrial; i 4) determinar si p53 mutat és capaç de regular l’estrès oxidatiu per l’adquisició d’un guany de funció. Els resultats obtinguts van mostrar que el silenciament de SIRT3 comprometia tant la funció mitocondrial com la resposta antioxidant en cèl·lules de càncer de mama i de còlon. A més, la combinació del silenciament amb l’ús de compostos antitumorals va millorar l’eficàcia d’aquests, incrementant la mort cel·lular. Per altra banda, l’activació de PGC-1α va induir la resposta antioxidant i va millorar la funció mitocondrial en línies de melanoma. Pel que fa a UCP2, el seu silenciament va incrementar la funcionalitat dels mitocondris i el consum d’oxigen, suggerint que UCP2 participa en la reprogramació metabòlica en el càncer de pàncrees. Finalment, l’estudi de p53 mutat a la línia cel·lular de melanoma MeWo suggereix que p53 mutat podria presentar una nova funció regulant UCP2 i SIRT3 com a estratègia per a mantenir els nivells de ROS controlats. Els resultats obtinguts a la present tesi permeten concloure que la modulació de proteïnes clau pel metabolisme de la cèl·lula tumoral, com SIRT3, PGC-1α, UCP2 o p53, podria considerar-se com a una estratègia de teràpia adjuvant per a millorar el tractament del càncer.[spa] Las células cancerosas presentan diversas características distintivas respecto a las células normales, entre las que destaca la reprogramación metabólica que sufren para poder sostener su elevada tasa de proliferación. Hoy en día se reconoce el papel fundamental que juegan las mitocondrias, principales productoras de ATP y de especies reactivas de oxígeno (ROS), en el desarrollo y la progresión del cáncer. Una proteína clave implicada en el control de la integridad mitocondrial y del estrés oxidativo es SIRT3, considerada el guardián de las mitocondrias. Otras proteínas que pueden tener un papel clave en el metabolismo tumoral son PGC-1α, regulador de la biogénesis mitocondrial; UCP2, implicada en la función mitocondrial y el estrés oxidativo; o p53, regulador de la respuesta antioxidante y supervivencia celular. Estas proteínas podrían ser posibles dianas para el tratamiento del cáncer. Los objetivos de esta tesis fueron los siguientes: 1) estudiar el papel de SIRT3 sobre el estrés oxidativo y la homeostasis mitocondrial en líneas de cáncer de mama y de colon, y si su silenciamiento puede mejorar la eficacia de los tratamientos antitumorales usados más frecuentemente; 2) analizar la importancia de PGC-1α sobre la respuesta al estrés oxidativo y la funcionalidad mitocondrial en líneas celulares de melanoma; 3) estudiar si el silenciamiento de UCP2 en células de cáncer de páncreas puede afectar a la función mitocondrial; y 4) determinar si p53 mutado es capaz de regular el estrés oxidativo por la adquisición de una ganancia de función. Los resultados obtenidos mostraron que el silenciamiento de SIRT3 comprometió tanto la función mitocondrial como la respuesta antioxidante en células de cáncer de mama y de colon. Además, la combinación del silenciamiento con el uso de compuestos antitumorales mejoró la eficacia de estos últimos, incrementando la muerte celular. Por otra parte, la activación de PGC-1α provocó la inducción de la respuesta antioxidante y mejoró la función mitocondrial en líneas de melanoma. Respecto a UCP2, su silenciamiento incrementó la funcionalidad mitocondrial y el consumo de oxígeno, sugiriendo que UCP2 participa en la reprogramación metabólica en el cáncer de páncreas. Finalmente, el estudio de p53 mutado en la línea celular de melanoma MeWo sugiere que p53 mutado podría presentar una nueva función regulando UCP2 y SIRT3 como parte de una estrategia para mantener los niveles de ROS controlados. Los resultados obtenidos en la presente tesis permiten concluir que la modulación de proteínas clave para el metabolismo de la célula tumoral, tales como SIRT3, PGC-1α, UCP2 o p53, podría considerarse como una estrategia de terapia adyuvante para mejorar el tratamiento del cáncer.[eng] Cancer cells exhibit some characteristics that distinguish them from normal cells. Among these hallmarks, the metabolic reprogramming is crucial to sustain their high proliferation rate. Mitochondria, the main source of ATP and reactive oxygen species (ROS), play a well-recognized role in cancer development and progression. SIRT3 is a key protein involved in the control of mitochondrial integrity and oxidative stress, and is considered the guardian of mitochondria. Other proteins that could have a crucial role in tumor metabolism are PGC-1α, regulator of mitochondrial biogenesis; UCP2, involved in mitochondrial function and oxidative stress; or p53, regulator of the antioxidant response and cell survival. These proteins could be new possible targets for cancer therapy. The objectives of this thesis were: 1) to study the role of SIRT3 in oxidative stress and mitochondrial homeostasis in breast and colon cancer cell lines, and whether its silencing could improve the efficacy of commonly used anticancer treatments; 2) to analyze the importance of PGC-1α on the response to oxidative stress and the mitochondrial functionality of melanoma cell lines; 3) to study whether UCP2 silencing in pancreatic cancer cells could affect mitochondrial function; and 4) to determine whether mutant p53 may regulate oxidative stress through the acquisition of a gain of function. The results showed that SIRT3 silencing compromised both mitochondrial function and antioxidant response in breast and colon cancer cells. Furthermore, the use of anticancer compounds in combination with SIRT3 knockdown increased the efficacy of these treatments, increasing cell death. On the other hand, PGC-1α activation induced the antioxidant response and improved mitochondrial function in melanoma cell lines. Regarding UCP2, its silencing increased mitochondria functionality and oxygen consumption, suggesting that UCP2 may be involved in the metabolic reprogramming of pancreatic cancer. Finally, the study of mutant p53 in MeWo melanoma cell line suggested that it could show a new function regulating UCP2 and SIRT3 as part of a strategy to control ROS levels. From the results obtained in this thesis, it can be concluded that the modulation of key proteins for cancer cells’ metabolism, such as SIRT3, PGC-1α, UCP2 or p53, could be considered as an adjuvant strategy to improve cancer treatment

L’aprenentatge basat en problemes aplicat a l’ensenyança de la Biologia i Geologia

[cat] L’aprenentatge basat en problemes o ABP és una metodologia didàctica que pren com a punt de partida per a l’aprenentatge una situació problemàtica i versemblant, relacionada amb la vida real. Es tracta d’una estratègia d’aprenentatge actiu en què es potencia l’autonomia dels alumnes, ja que han d’identificar, tot treballant en petits grups, què saben i què els fa falta per resoldre el problema. Posteriorment, cada alumne ha de fer la recerca d’informació necessària per posar-la després en comú i discutir-la amb el seu grup, per tal d’arribar a una possible solució al problema inicial plantejat. A banda de construir nous coneixements de manera autònoma, l’ABP permet treballar, a més, competències i habilitats com aprendre a aprendre, raonament crític, autoavaluació, treball en equip, comunicació i aprenentatge cooperatiu, entre d’altres. El paper del professor en aquesta metodologia és actuar com a guia i facilitador de l’aprenentatge, estimulant debats dins el grup i preguntes que dirigeixin els esforços de l’estudiant. Tot i que l’ABP presenta alguns desavantatges, està guanyant cada vegada més interès per aplicar-ho a secundària i batxillerat. Per aquest motiu, en aquest treball es presenta una proposta didàctica pel curs de 3r d’ESO basada en l’ABP, en la qual es pretén que els alumnes treballin conceptes del sistema nerviós a partir d’una situació problemàtica contextualitzada en el consum de drogues. Alhora, s’intenta que adquireixin el coneixement necessari per tal d’actuar de manera responsable i desenvolupar conductes saludables

SIRT3: Oncogene and Tumor Suppressor in Cancer

Sirtuin 3 (SIRT3), the major deacetylase in mitochondria, plays a crucial role in modulating oxygen reactive species (ROS) and limiting the oxidative damage in cellular components. SIRT3 targets different enzymes which regulate mitochondrial metabolism and participate in ROS detoxification, such as the complexes of the respiratory chain, the isocitrate dehydrogenase, or the manganese superoxide dismutase. Thus, SIRT3 activity is essential in maintaining mitochondria homeostasis and has recently received great attention, as it is considered a fidelity protein for mitochondrial function. In some types of cancer, SIRT3 functions as a tumoral promoter, since it keeps ROS levels under a certain threshold compatible with cell viability and proliferation. On the contrary, other studies describe SIRT3 as a tumoral suppressor, as SIRT3 could trigger cell death under stress conditions. Thus, SIRT3 could have a dual role in cancer. In this regard, modulation of SIRT3 activity could be a new target to develop more personalized therapies against cancer

Sex Specific Differences in Response to Calorie Restriction in Skeletal Muscle of Young Rats

Calorie restriction (CR), defined as a reduction of the total calorie intake of 30% to 60% without malnutrition, is the only nutritional strategy that has been shown to extend lifespan, prevent or delay the onset of age-associated diseases, and delay the functional decline in a wide range of species. However, little is known about the effects of CR when started early in life. We sought to analyze the effects of CR in the skeletal muscle of young Wistar rats. For this, 3-month-old male and female rats were subjected to 40% CR or fed ad libitum for 3 months. Gastrocnemius muscles were used to extract RNA and total protein. Western blot and RT-qPCR were performed to evaluate the expression of key markers/pathways modulated by CR and affected by aging. CR decreased body and skeletal muscle weight in both sexes. No differences were found in most senescence, antioxidant, and nutrient sensing pathways analyzed. However, we found a sexual dimorphism in markers of oxidative stress, inflammation, apoptosis, and mitochondrial function in response to CR. Our data show that young female rats treated with CR exhibit similar expression patterns of key genes/pathways associated with healthy aging when compared to old animals treated with CR, while in male rats these effects are reduced. Additional studies are needed to understand how early or later life CR exerts positive effects on healthspan and lifespan

High Concentrations of Genistein Decrease Cell Viability Depending on Oxidative Stress and Inflammation in Colon Cancer Cell Lines

Genistein could play a crucial role in modulating three closely linked physiological processes altered during cancer: oxidative stress, mitochondrial biogenesis, and inflammation. However, genistein’s role in colorectal cancer remains unclear. We aimed to determine genistein’s effects in two colon cancer cells: HT29 and SW620, primary and metastatic cancer cells, respectively. After genistein treatment for 48 h, cell viability and hydrogen peroxide (H2O2) production were studied. The cell cycle was studied by flow cytometry, mRNA and protein levels were analyzed by RT-qPCR and Western blot, respectively, and finally, cytoskeleton remodeling and NF-κB translocation were determined by confocal microscopy. Genistein 100 µM decreased cell viability and produced G2/M arrest, increased H2O2, and produced filopodia in SW620 cells. In HT29 cells, genistein produced an increase of cell death, H2O2 production, and in the number of stress fibers. In HT29 cells, mitochondrial biogenesis was increased, however, in SW620 cells, it was decreased. Finally, the expression of inflammation-related genes increased in both cell lines, being greater in SW620 cells, where NF-κB translocation to the nucleus was higher. These results indicate that high concentrations of genistein could increase oxidative stress and inflammation in colon cancer cells and, ultimately, decrease cell viability

Mutant p53 induces SIRT3/MnSOD axis to moderate ROS production in melanoma cells

The TP53 tumor suppressor gene is the most frequently altered gene in tumors and mutant p53 isoforms can acquire oncogenic properties referred to as gain-of-function (GOF). In this study, we used wild-type (A375) and mutant p53 (MeWo) melanoma cell lines to assess the regulation of the mitochondrial antioxidant manganese superoxide dismutase (MnSOD) by mutant p53. The effects of mutant p53 were evaluated by qPCR, immunoblotting, enzyme activity assay, cell proliferation assay, reactive oxygen species (ROS) assay after cellular transfection. We demonstrate that mutant p53 induces MnSOD expression, which is recovered by the ROS scavenger N-acetyl-l-cysteine. This suggests MnSOD induction as a defense mechanism of melanoma cells to counterbalance the pro-oxidant conditions induced by mutant p53. We also demonstrate that mutant p53 induces the expression of Sirtuin3 (SIRT3), a major mitochondrial NAD+-dependent deacetylase, stimulating MnSOD deacetylation and enzymatic activity. Indeed, the restoration of SIRT3 reverses MnSOD activity decrease by mutant p53 knock-down. Finally, MnSOD knock-down further enhances mutant p53-mediated ROS increase, contracting mutp53-dependent cell hyperproliferation. This indicates that SIRT3 and MnSOD act to maintain ROS levels controlled to promote cell proliferation and survival, providing new therapeutic opportunities to be further considered for clinical studies in cancer patients bearing mutant TP53 gene

Use of Omics Technologies for the Detection of Colorectal Cancer Biomarkers

Colorectal cancer (CRC) is one of the most frequently diagnosed cancers with high mortality rates, especially when detected at later stages. Early detection of CRC can substantially raise the 5-year survival rate of patients, and different efforts are being put into developing enhanced CRC screening programs. Currently, the faecal immunochemical test with a follow-up colonoscopy is being implemented for CRC screening. However, there is still a medical need to describe biomarkers that help with CRC detection and monitor CRC patients. The use of omics techniques holds promise to detect new biomarkers for CRC. In this review, we discuss the use of omics in different types of samples, including breath, urine, stool, blood, bowel lavage fluid, or tumour tissue, and highlight some of the biomarkers that have been recently described with omics data. Finally, we also review the use of extracellular vesicles as an improved and promising instrument for biomarker detection

Organoids: An Emerging Tool to Study Aging Signature across Human Tissues. Modeling Aging with Patient-Derived Organoids

The biology of aging is focused on the identification of novel pathways that regulate the underlying processes of aging to develop interventions aimed at delaying the onset and progression of chronic diseases to extend lifespan. However, the research on the aging field has been conducted mainly in animal models, yeast, Caenorhabditis elegans, and cell cultures. Thus, it is unclear to what extent this knowledge is transferable to humans since they might not reflect the complexity of aging in people. An organoid culture is an in vitro 3D cell-culture technology that reproduces the physiological and cellular composition of the tissues and/or organs. This technology is being used in the cancer field to predict the response of a patient-derived tumor to a certain drug or treatment serving as patient stratification and drug-guidance approaches. Modeling aging with patient-derived organoids has a tremendous potential as a preclinical model tool to discover new biomarkers of aging, to predict adverse outcomes during aging, and to design personalized approaches for the prevention and treatment of aging-related diseases and geriatric syndromes. This could represent a novel approach to study chronological and/or biological aging, paving the way to personalized interventions targeting the biology of aging

Circulating Neurofilament Light Chain Levels Increase with Age and Are Associated with Worse Physical Function and Body Composition in Men but Not in Women

This study aimed to assess the relationship between age-related changes in Neurofilament Light Chain (NFL), a marker of neuronal function, and various factors including muscle function, body composition, and metabolomic markers. The study included 40 participants, aged 20 to 85 years. NFL levels were measured, and muscle function, body composition, and metabolomic markers were assessed. NFL levels increased significantly with age, particularly in men. Negative correlations were found between NFL levels and measures of muscle function, such as grip strength, walking speed, and chair test performance, indicating a decline in muscle performance with increasing NFL. These associations were more pronounced in men. NFL levels also negatively correlated with muscle quality in men, as measured by 50 kHz phase angle. In terms of body composition, NFL was positively correlated with markers of fat mass and negatively correlated with markers of muscle mass, predominantly in men. Metabolomic analysis revealed significant associations between NFL levels and specific metabolites, with gender-dependent relationships observed. This study provides insights into the relationship between circulating serum NFL, muscle function, and aging. Our findings hint at circulating NFL as a potential early marker of age-associated neurodegenerative processes, especially in men