Identification of Differentially Expressed MicroRNAs in the Rat Hippocampus during Adolescence through an Epigenome-Wide Analysis

This study was funded by the research projects PID2020-114269GB-I00 (MCIN/AEI/10.13039/501100011033), BSEJ.514.UGR20 (FEDER, Junta de Andalucía, Spain), “Instituto de Salud Carlos III,” project PI18/00467 (co-funded by European Regional Development Fund/European Social Fund “A way to make Europe”/“Investing in your future”), and a predoctoral fellowship to AV-Á (FPU18/05012, MIU, Spain).Introduction: Epigenetic mechanisms involving microRNAs (miRNAs) play a fundamental role in many biological processes, particularly during prenatal and early postnatal development. Their role in adolescent brain development, however, has been poorly described. The present study aimed to explore miRNA expression in the hippocampus during adolescence compared to adulthood in rats. Method: The brains of female and male Wistar rats were extracted, and the hippocampus was freshly dissected at postnatal day 41 (adolescence) and postnatal day 98 (adulthood). An epigenome-wide analysis was conducted to identify the miRNAs significantly expressed in adolescence compared to adulthood. Additionally, target genes of such miRNAs were considered to perform an exploratory Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. Results: We identified 16 differentially expressed miRNAs in adolescent male rats compared with adult male rats and 4 differentially expressed miRNAs in adolescent females compared with adult females. Enrichment analysis reinforced that the target genes found are related to neurodevelopmental processes such as cell proliferation, cell migration, and nervous system development. Conclusion: Our findings suggest a complex pattern of miRNA expression during adolescence, which differs from that in adulthood. The differential expression of miRNA in the hippocampus during adolescence may be associated with the late developmental changes occurring in this brain region. Furthermore, the observed sex differences in miRNA expression patterns indicate potential sexual differentiation in hippocampal development. Further comprehensive investigations are needed to elucidate the roles of miRNA in normal brain development.MCIN/AEI/10.13039/501100011033 PID2020-114269GB-I00FEDER BSEJ.514.UGR20Junta de Andalucía, SpainEuropean Regional Development Fund “Instituto de Salud Carlos III” PI18/00467FPU18/05012, MIU, SpainUniversity of Granad

Understanding microRNAs in the Context of Infection to Find New Treatments against Human Bacterial Pathogens

[EN] The development of RNA-based anti-infectives has gained interest with the successful application of mRNA-based vaccines. Small RNAs are molecules of RNA of <200 nucleotides in length that may control the expression of specific genes. Small RNAs include small interference RNAs (siRNAs), Piwi-interacting RNAs (piRNAs), or microRNAs (miRNAs). Notably, the role of miRNAs on the post-transcriptional regulation of gene expression has been studied in detail in the context of cancer and many other genetic diseases. However, it is also becoming apparent that some human miRNAs possess important antimicrobial roles by silencing host genes essential for the progress of bacterial or viral infections. Therefore, their potential use as novel antimicrobial therapies has gained interest during the last decade. The challenges of the transport and delivery of miRNAs to target cells are important, but recent research with exosomes is overcoming the limitations in RNA-cellular uptake, avoiding their degradation. Therefore, in this review, we have summarised the latest developments in the exosomal delivery of miRNA-based therapies, which may soon be another complementary treatment to pathogen-targeted antibiotics that could help solve the problem caused by multidrug-resistant bacteriaSIWe thank the Junta de Castilla y León (Spain) for funding our research work on microRNAs, grant number LE044P20. A.M. is supported with a postdoctoral fellowship “Margarita Salas”. M.L. is the recipient of a “Beatriz Galindo” grant (Ref. BEAGAL18/00068 - BGP18/00033

Identificación y caracterización de esterasas de Lactobacillus plantarum con interés en tecnología de alimentos

Resumen del trabajo presentado a la 7ª Reunión de la Red Tematica Bal: "Participación de las Bacterias Lácticas en la Salud Humana y en la Calidad Alimentaria" celebrado en Madrid del 4 al 5 de julio de 2013.Los ésteres son compuestos aromáticos que a pesar de encontrarse en niveles traza, son muy importantes en el perfil aromático de los alimentos. Pequeñas variaciones en los niveles de estos compuestos pueden tener importantes efectos en el aroma, y por lo tanto en la calidad, de los alimentos. Los ésteres de los alimentos se originan por acción de enzimas con actividad esterasa (EC 3.1.1.x) que pueden catalizar tanto reacciones de hidrólisis como de síntesis en función de las condiciones de reacción, por lo que tienen un gran interés en biotecnología. Entre estas enzimas se pueden distinguir carboxilesterasas, arilesterasas y lipasas. Las carboxilesterasas y las arilesterasas catalizan la hidrólisis de ésteres de cadena alifática corta o media solubles en agua, mientras que las lipasas presentan actividad frente a ésteres de cadena larga e insolubles en agua. Las feruloil esterasas, son un tipo de arilesterasas capaces de hidrolizar el enlace éster entre los ácidos cinámicos y los azúcares de las paredes celulares vegetales liberando compuestos fenólicos como el ácido cafeico, p-cumárico y ferúlico, los cuales presentan numerosas aplicaciones en la industria alimentaría. Lactobacillus plantarum es la especie de bacteria láctica modelo en fermentaciones de sustratos vegetales, en donde los ésteres de compuestos fenólicos, se encuentran en altas concentraciones. En el genoma de L. plantarum aparecen anotados genes que codifican “esterasas” o “lipasas” cuya funcionalidad no se ha comprobado bioquímicamente a pesar del interés biotecnológico que presentan. Por ello el objetivo de este trabajo es la identificación y caracterización de posibles esterasas en L. plantarum WCFS1. A pesar de que se han clonado los genes que codifican 14 posibles esterasas o lipasas, sólo se han podido producir y purificar correctamente las proteínas Lp_0796, Lp_0973, Lp_1002, Lp_2923, Lp_2987, Lp_3561 y Lp_3562. Utilizando ésteres derivados de p-nitrofenilo que varían en la longitud de su cadena alifática (desde acetato de p-nitrofenilo hasta palmitato de pnitrofenilo) se ha comprobado que todas las proteínas estudiadas hidrolizan mejor los ésteres de cadena corta, aunque Lp_1002, Lp_2926 y Lp_3562 también hidrolizan eficazmente palmitato de p-nitrofenilo.La proteína Lp_2987 es la única que no presenta actividad sobre ninguno de los derivados ensayados por lo que no se puede considerar como “esterasa”. La especificidad de substrato de las esterasas también se ha evaluado mediante una colección de ésteres que permite conocer su selectividad respecto a la carga del substrato, al tamaño de la cadena o al alcohol presente. Todas las proteínas purificadas, excepto Lp_2987, presentan actividad sobre acetato de fenilo, por lo que se pueden considerar como “aril esterasas”. La proteína Lp_0973 es la única que, además de acetato de fenilo, degrada triacetina y tributirina. De las esterasas estudiadas, la proteína Lp_0796 es la más interesante puesto que es una “feruloil esterasa” que hidroliza ésteres de ácidos hidroxicinámicos, siendo la primera vez que se describe una proteína con esta actividad en L. plantarum. Con objeto de mejorar la actividad de las esterasas para su posible uso industrial se han realizado experimentos de cristalización, inmovilización y evolución dirigida de alguna de ellas. Los resultados obtenidos indican que L. plantarum es una fuente adecuada de enzimas con actividad esterasa de gran influencia en el aroma de los alimentos.Peer reviewe

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

Understanding microRNAs in the Context of Infection to Find New Treatments against Human Bacterial Pathogens

The development of RNA-based anti-infectives has gained interest with the successful application of mRNA-based vaccines. Small RNAs are molecules of RNA of <200 nucleotides in length that may control the expression of specific genes. Small RNAs include small interference RNAs (siRNAs), Piwi-interacting RNAs (piRNAs), or microRNAs (miRNAs). Notably, the role of miRNAs on the post-transcriptional regulation of gene expression has been studied in detail in the context of cancer and many other genetic diseases. However, it is also becoming apparent that some human miRNAs possess important antimicrobial roles by silencing host genes essential for the progress of bacterial or viral infections. Therefore, their potential use as novel antimicrobial therapies has gained interest during the last decade. The challenges of the transport and delivery of miRNAs to target cells are important, but recent research with exosomes is overcoming the limitations in RNA-cellular uptake, avoiding their degradation. Therefore, in this review, we have summarised the latest developments in the exosomal delivery of miRNA-based therapies, which may soon be another complementary treatment to pathogen-targeted antibiotics that could help solve the problem caused by multidrug-resistant bacteria

Blood-Based Biomarkers to Search for Atrial Fibrillation in High-Risk Asymptomatic Individuals and Cryptogenic Stroke Patients.

Atrial fibrillation (AF) increases the risk of ischemic stroke in asymptomatic individuals and may be the underlying cause of many cryptogenic strokes. We aimed to test the usefulness of candidate blood-biomarkers related to AF pathophysiology in two prospective cohorts representative of those populations. Two hundred seventy-four subjects aged 65-75 years with hypertension and diabetes from the AFRICAT cohort, and 218 cryptogenic stroke patients aged >55 years from the CRYPTO-AF cohort were analyzed. AF was assessed by 4 weeks of monitoring with a wearable Holter device (NuuboTM™). Blood was collected immediately before monitoring started. 10 candidate biomarkers were measured by automated immunoassays (Roche, Penzberg) in the plasma of all patients. Univariate and logistic regression analyses were performed in each cohort separately. Atrial fibrillation detection rate was 12.4% (AFRICAT cohort) and 22.9% (CRYPTO-AF cohort). 4 biomarkers were significantly increased in asymptomatic individuals with AF [Troponin-T, Angiopoietin-2 (Ang-2), Endocan, and total N-terminal pro-B type natriuretic peptide (NT-proBNP)] and 7 biomarkers showed significantly higher concentrations in cryptogenic stroke patients with AF detection [growth differentiation factor 15, interleukin 6, Troponin-T, Ang-2, Bone morphogenic protein 10, Dickkopf-related protein 3 (DKK-3), and total NT-proBNP]. The models including Ang-2 and total NT-proBNP [AUC 0.764 (0.665-0.863)], and Ang-2 and DKK-3 [AUC = 0.733 (0.654-0.813)], together with age and sex, showed the best performance to detect AF in high-risk asymptomatic individuals, and in cryptogenic stroke patients, respectively. Blood-biomarkers, in particular, total NT-proBNP, DKK-3, and Ang-2, were associated with AF reflecting two mechanistically different pathways involved in AF pathophysiology (AF stretch and vascular changes). The combination of these biomarkers could be useful in AF screening strategies in the primary care setting and also for searching AF after cryptogenic stroke

Characteristics, complications and outcomes among 1549 patients hospitalised with COVID-19 in a secondary hospital in Madrid, Spain: a retrospective case series study

Objectives To describe demographic, clinical, radiological and laboratory characteristics, as well as outcomes, of patients admitted for COVID-19 in a secondary hospital.Design and setting Retrospective case series of sequentially hospitalised patients with confirmed SARS-CoV-2, at Infanta Leonor University Hospital (ILUH) in Madrid, Spain.Participants All patients attended at ILUH testing positive to reverse transcriptase-PCR on nasopharyngeal swabs and diagnosed with COVID-19 between 1 March 2020 and 28 May 2020.Results A total of 1549 COVID-19 cases were included (median age 69 years (IQR 55.0–81.0), 57.5% men). 78.2% had at least one underlying comorbidity, the most frequent was hypertension (55.8%). Most frequent symptoms at presentation were fever (75.3%), cough (65.7%) and dyspnoea (58.1%). 81 (5.8%) patients were admitted to the intensive care unit (ICU) (median age 62 years (IQR 51–71); 74.1% men; median length of stay 9 days (IQR 5–19)) 82.7% of them needed invasive ventilation support. 1393 patients had an outcome at the end of the study period (case fatality ratio: 21.2% (296/1393)). The independent factors associated with fatality (OR; 95% CI): age (1.07; 1.06 to 1.09), male sex (2.86; 1.85 to 4.50), neurological disease (1.93; 1.19 to 3.13), chronic kidney disease (2.83; 1.40 to 5.71) and neoplasia (4.29; 2.40 to 7.67). The percentage of hospital beds occupied with COVID-19 almost doubled (702/361), with the number of patients in ICU quadrupling its capacity (32/8). Median length of stay was 9 days (IQR 6–14).Conclusions This study provides clinical characteristics, complications and outcomes of patients with COVID-19 admitted to a European secondary hospital. Fatal outcomes were similar to those reported by hospitals with a higher level of complexity