IF1 is a cold-regulated switch of ATP synthase hydrolytic activity to support thermogenesis in brown fat.

While mechanisms controlling uncoupling protein-1 (UCP1) in thermogenic adipocytes play a pivotal role in non-shivering thermogenesis, it remains unclear whether F1Fo-ATP synthase function is also regulated in brown adipose tissue (BAT). Here, we show that inhibitory factor 1 (IF1, encoded by Atp5if1), an inhibitor of ATP synthase hydrolytic activity, is a critical negative regulator of brown adipocyte energy metabolism. In vivo, IF1 levels are diminished in BAT of cold-adapted mice compared to controls. Additionally, the capacity of ATP synthase to generate mitochondrial membrane potential (MMP) through ATP hydrolysis (the so-called "reverse mode" of ATP synthase) is increased in brown fat. In cultured brown adipocytes, IF1 overexpression results in an inability of mitochondria to sustain the MMP upon adrenergic stimulation, leading to a quiescent-like phenotype in brown adipocytes. In mice, adeno-associated virus-mediated IF1 overexpression in BAT suppresses adrenergic-stimulated thermogenesis and decreases mitochondrial respiration in BAT. Taken together, our work identifies downregulation of IF1 upon cold as a critical event for the facilitation of the reverse mode of ATP synthase as well as to enable energetic adaptation of BAT to effectively support non-shivering thermogenesis.

Caracterización de los adolescentes participantes en el ensayo clínico con la vacuna Abdala / Characterization of participants adolescents in the clinical trial with Abdala vaccine

Introducción: La evaluación clínica de vacunas anti-COVID-19 en edades pediátricas, es un desafío en tiempos de pandemia; responde a la urgencia de muestras representativas que contribuyan a la reproducibilidad del estudio en la población real. Objetivo: Caracterizar a los adolescentes participantes del ensayo clínico con la vacuna anti-COVID-19 Abdala, evaluar el cumplimiento del esquema de vacunación y estimar si son representativos de este grupo poblacional. Métodos: Se utilizaron los datos de un ensayo fase II, monocéntrico, no controlado con la vacuna Abdala. Se incluyeron 703 sujetos; 207 (29,4 por ciento) fueron adolescentes de entre 12 y 18 años, aparentemente sanos o con enfermedades crónicas controladas, valoración nutricional entre 10 y 90 percentil y voluntariedad para participar. Se estudiaron datos sociodemográficos, antecedentes patológicos personales, hábitos tóxicos y cumplimiento del esquema de vacunación. Resultados: El promedio de edad fue de 15 años, predominó el sexo femenino (51,7 por ciento), el color de la piel blanca (55,6 por ciento) y la valoración nutricional por encima del 75 hasta el 90 percentil (40,6 por ciento). El 9,6 por ciento tuvo hábitos tóxicos como hábito de fumar e ingestión de bebidas alcohólicas. El 51,2 por ciento presentó algún antecedente patológico personal, con mayor prevalencia para asma bronquial, rinitis y otras alergias. El 95,8 por ciento cumplió con el esquema de vacunación. Conclusiones: Las características sociodemográficas, los antecedentes patológicos personales y hábitos tóxicos descritos en los adolescentes del estudio son representativos para este grupo poblacional de Cuba. Se alcanzó un óptimo cumplimiento del esquema de vacunación(AU)

Introduction: The clinical evaluation of anti-COVID-19 vaccines in pediatric population, is a challenge in times of pandemic, to respond to the urgency of representative samples that contribute to the reproducibility of the study in the real population. Objective: To characterize the adolescents participating in the clinical trial with the Abdala anti-COVID-19 vaccine, to evaluate compliance with the vaccination schedule and to estimate whether they are representative of this population group. Methods: Data from a phase II trial with Abdala vaccine were used. A total of 703 subjects were included, 207 (29.4 percent) of them were adolescents, between 12 and 18 years of age, with apparently healthy or controlled chronic diseases, nutritional assessment between 10 and 90 percentiles, and willingness to participate in the study. Sociodemographic data, personal pathological history, toxic habits and compliance with the vaccination scheme of 3 doses every 14 days were the variables studied. Results: The average age was 15 years, it was predominant female sex (51.7 percent), white skin color (55.6 percent) and nutritional assessment above 75 to 90 percentiles (40.6 percent). The 9.6 percent had toxic habits such as smoking and ingestion of alcoholic beverages. Some personal pathological history was in 51.2 percent with a higher prevalence for bronchial asthma, rhinitis and other allergies. The vaccination scheme was fulfilled for 95.8 percent of individuals. Conclusions: Sociodemographic characteristics, pathological history and toxic habits described for adolescents on the study are representative for this population group in Cuba. The vaccination schedule had an optimal compliance(AU)

A phase 3, randomised, double-blind, placebo-controlled clinical trial evaluation of the efficacy and safety of a SARS-CoV-2 recombinant spike RBD protein vaccine in adults (ABDALA-3 study).

Background: The pandemic of COVID-19 raised the urgent need for safe and efficacious vaccines against SARS-CoV-2. We evaluated the efficacy and safety of a new SARS-CoV-2 virus receptor-binding domain (RBD) vaccine. Methods: A phase 3, multicentre, randomised, double-blind, placebo-controlled trial was carried out at 18 clinical sites in three provinces of the south-eastern region of Cuba. Subjects (healthy or those with controlled chronic diseases) aged between 19 and 80 years, who gave written informed consent were eligible. Subjects were randomly assigned (1:1, in blocks) to two groups: placebo, and 50 µg RBD vaccine (Abdala). The product was administered intramuscularly, 0.5 mL in the deltoid region, in a three-dose immunization schedule at 0-14-28 days. The organoleptic characteristics and presentations of the vaccine and placebo were identical. All participants (subjects, clinical researchers, statisticians, laboratory technicians, and monitors) remained blinded during the study period. The main endpoint was to evaluate the efficacy of the Abdala vaccine in the prevention of symptomatic COVID-19. The trial is registered with the Cuban Public Registry of Clinical Trials, RPCEC00000359. Findings: Between March 22 to April 03, 2021, 48,290 subjects were included (24,144 and 24,146 in the placebo and Abdala groups, respectively) in the context of predominant D614G variant circulation. The evaluation of the main efficacy outcomes occurred during May-June 2021, starting at May 3rd, in the context of high circulation of mutant viruses, predominantly VOC Beta. The incidence of adverse reactions for individuals in the placebo and Abdala vaccine groups were 1227/24,144 (5.1%) and 1621/24,146 (6.7%), respectively. Adverse reactions were mostly mild, and from the injection site, which resolved in the first 24-48 h. No severe adverse events with demonstrated cause-effect relationship attributable to the vaccine were reported. Symptomatic COVID-19 disease was confirmed in 142 participants in the placebo group (78.44 incidence per 1000 person-years, 95% confidence interval [CI], 66.07-92.46) and in 11 participants in Abdala vaccine group (6.05 incidence per 1000 person years; 95% CI 3.02-10.82). The Abdala vaccine efficacy against symptomatic COVID-19 was 92.28% (95% CI 85.74-95.82). Moderate/serious forms of COVID-19 occurred in 30 participants (28 in the placebo group and only 2 in the Abdala vaccine group) for a vaccine efficacy of 92.88% (95% CI 70.12-98.31). There were five critical patients (of which four died), all in the placebo group. Interpretation: The Abdala vaccine was safe, well tolerated, and highly effective, fulfilling the WHO target product profile for COVID-19 vaccines. Those results, along with its immunization schedule and the advantage of easy storage and handling conditions at 2-8 °C, make this vaccine an option for the use in immunization strategies as a key tool for the control of the pandemic. Funding: Centre for Genetic Engineering and Biotechnology (CIGB), Havana, Cuba.

Trained innate immunity, long-lasting epigenetic modulation, and skewed myelopoiesis by heme.

Trained immunity defines long-lasting adaptations of innate immunity based on transcriptional and epigenetic modifications of myeloid cells and their bone marrow progenitors [M. Divangahi et al., Nat. Immunol. 22, 2-6 (2021)]. Innate immune cells, however, do not exclusively differentiate between foreign and self but also react to host-derived molecules referred to as alarmins. Extracellular "labile" heme, released during infections, is a bona fide alarmin promoting myeloid cell activation [M. P. Soares, M. T. Bozza, Curr. Opin. Immunol. 38, 94-100 (2016)]. Here, we report that labile heme is a previously unrecognized inducer of trained immunity that confers long-term regulation of lineage specification of hematopoietic stem cells and progenitor cells. In contrast to previous reports on trained immunity, essentially mediated by pathogen-associated molecular patterns, heme training depends on spleen tyrosine kinase signal transduction pathway acting upstream of c-Jun N-terminal kinases. Heme training promotes resistance to sepsis, is associated with the expansion of self-renewing hematopoetic stem cells primed toward myelopoiesis and to the occurrence of a specific myeloid cell population. This is potentially evoked by sustained activity of Nfix, Runx1, and Nfe2l2 and dissociation of the transcriptional repressor Bach2. Previously reported trained immunity inducers are, however, infrequently present in the host, whereas heme abundantly occurs during noninfectious and infectious disease. This difference might explain the vanishing protection exerted by heme training in sepsis over time with sustained long-term myeloid adaptations. Hence, we propose that trained immunity is an integral component of innate immunity with distinct functional differences on infectious disease outcome depending on its induction by pathogenic or endogenous molecules.

Generation and characterization of murine monoclonal antibodies against immunoreactive trypsinogen for newborn screening of cystic fibrosis.

Cystic fibrosis (CF) is a multisystem disorder that reduces quality of life and survival in affected individuals. In newborns, the release of pancreatic enzymes into the blood raises the levels of immunoreactive trypsinogen (IRT), the main marker for CF screening, which is detected in dried blood samples on filter paper by immunoenzymatic assays. In Cuba, CF has an estimated incidence of 1/9862 live births and should be included in the national basic newborn screening (NBS) panel given its benefits in terms of nutrition, lung function and survival. The Immunoassay Center develops and produces diagnostic kits allowing the establishment of large-scale NBS programs for inherited metabolic disorders in Cuba and other Latin American countries. IRT-specific monoclonal antibodies (MAbs) obtained at the Immunoassay Center are essential for developing an affordable immunoassay for IRT to support CF NBS in our low-income country. An immunization scheme with trypsinogen-1 originated two IgG1-producing murine hybridomas. 4C9C9 and 4C9E11 MAbs recognized different determinants on both trypsin-1 and trypsin-2 molecules. Both antibodies identified conformational epitopes on the molecule of trypsin-1 and of its zymogen. As 4C9E11 MAb cross-reacted with proteins structurally and functionally related to trypsinogen, it was used as revealing antibody in a sandwich-type UMELISA® assay for IRT determination with 4C9C9 MAb for capture. This combination, aside from detecting several commercially available trypsins, adequately quantified IRT from dried blood samples on filter paper of newborns. The evaluation of the assay's accuracy yielded percentage recoveries ranging 93.3-109.2% for commercial controls. The properties of the studied MAbs demonstrate their suitability for being used in a sandwich-type UMELISA® assay for the CF NBS in Cuba.

Phenolic Metabolites Modulate Cardiomyocyte Beating in Response to Isoproterenol.

Cardiovascular disease (CVD) is a public health concern, and the third cause of death worldwide. Several epidemiological studies and experimental approaches have demonstrated that consumption of polyphenol-enriched fruits and vegetables can promote cardioprotection. Thus, diet plays a key role in CVD development and/or prevention. Physiological ß-adrenergic stimulation promotes beneficial inotropic effects by increasing heart rate, contractility and relaxation speed of cardiomyocytes. Nevertheless, chronic activation of ß-adrenergic receptors can cause arrhythmias, oxidative stress and cell death. Herein the cardioprotective effect of human metabolites derived from polyphenols present in berries was assessed in cardiomyocytes, in response to chronic ß-adrenergic stimulation, to disclose some of the underlying molecular mechanisms. Ventricular cardiomyocytes derived from neonate rats were treated with three human bioavailable phenolic metabolites found in circulating human plasma, following berries' ingestion (catechol-O-sulphate, pyrogallol-O-sulphate, and 1-methylpyrogallol-O-sulphate). The experimental conditions mimic the physiological concentrations and circulating time of these metabolites in the human plasma (2 h). Cardiomyocytes were then challenged with the ß-adrenergic agonist isoproterenol (ISO) for 24 h. The presence of phenolic metabolites limited ISO-induced mitochondrial oxidative stress. Likewise, phenolic metabolites increased cell beating rate and synchronized cardiomyocyte beating population, following prolonged ß-adrenergic receptor activation. Finally, phenolic metabolites also prevented ISO-increased activation of PKA-cAMP pathway, modulating Ca2+ signalling and rescuing cells from an arrhythmogenic Ca2+ transients' phenotype. Unexpected cardioprotective properties of the recently identified human-circulating berry-derived polyphenol metabolites were identified. These metabolites modulate cardiomyocyte beating and Ca2+ transients following ß-adrenergic prolonged stimulation.