Acute Effects of Dietary Protein Consumption on the Postprandial Metabolic Response, Amino Acid Levels and Circulating MicroRNAs in Patients with Obesity and Insulin Resistance.

The post-nutritional intervention modulation of miRNA expression has been previously investigated; however, post-acute dietary-ingestion-related miRNA expression dynamics in individuals with obesity and insulin resistance (IR) are unknown. We aimed to determine the acute effects of protein ingestion from different dietary sources on the postprandial metabolic response, amino acid levels, and circulating miRNA expression in adults with obesity and IR. This clinical trial included adults with obesity and IR who consumed (1) animal-source protein (AP; calcium caseinate) or (2) vegetable-source protein (VP; soy protein isolate). Glycaemic, insulinaemic, and glucagon responses, amino acid levels, and exosomal microRNAs isolated from plasma were analysed. Post-AP ingestion, the area under the curve (AUC) of insulin (p = 0.04) and the plasma concentrations of branched-chain (p = 0.007) and gluconeogenic (p = 0.01) amino acids increased. The effects of different types of proteins on the concentration of miRNAs were evaluated by measuring their plasma circulating levels. Compared with the baseline, the AP group presented increased circulating levels of miR-27a-3p, miR-29b-3p, and miR-122-5p (p < 0.05). Subsequent analysis over time at 0, 30, and 60 min revealed the same pattern and differences between treatments. We demonstrated that a single dose of dietary protein has acute effects on hormonal and metabolic regulation and increases exosomal miRNA expression in individuals with obesity and IR.

Intermittent fasting, calorie restriction, and a ketogenic diet improve mitochondrial function by reducing lipopolysaccharide signaling in monocytes during obesity: A randomized clinical trial.

BACKGROUND: Mitochondrial dysfunction occurs in monocytes during obesity and contributes to a low-grade inflammatory state; therefore, maintaining good mitochondrial conditions is a key aspect of maintaining health. Dietary interventions are primary strategies for treating obesity, but little is known about their impact on monocyte bioenergetics. Thus, the aim of this study was to evaluate the effects of calorie restriction (CR), intermittent fasting (IF), a ketogenic diet (KD), and an ad libitum habitual diet (AL) on mitochondrial function in monocytes and its modulation by the gut microbiota. METHODS AND FINDINGS: A randomized controlled clinical trial was conducted in which individuals with obesity were assigned to one of the 4 groups for 1 month. Subsequently, the subjects received rifaximin and continued with the assigned diet for another month. The oxygen consumption rate (OCR) was evaluated in isolated monocytes, as was the gut microbiota composition in feces and anthropometric and biochemical parameters. Forty-four subjects completed the study, and those who underwent CR, IF and KD interventions had an increase in the maximal respiration OCR (p = 0.025, n2p = 0.159 [0.05, 0.27] 95% confidence interval) in monocytes compared to that in the AL group. The improvement in mitochondrial function was associated with a decrease in monocyte dependence on glycolysis after the IF and KD interventions. Together, diet and rifaximin increased the gut microbiota diversity in the IF and KD groups (p = 0.0001), enriched the abundance of Phascolarctobacterium faecium (p = 0.019) in the CR group and Ruminococcus bromii (p = 0.020) in the CR and KD groups, and reduced the abundance of lipopolysaccharide (LPS)-producing bacteria after CR, IF and KD interventions compared to the AL group at the end of the study according to ANCOVA with covariate adjustment. Spearman's correlation between the variables measured highlighted LPS as a potential modulator of the observed effects. In line with this findings, serum LPS and intracellular signaling in monocytes decreased with the three interventions (CR, p = 0.002; IF, p = 0.001; and KD, p = 0.001) compared to those in the AL group at the end of the study. CONCLUSIONS: We conclude that these dietary interventions positively regulate mitochondrial bioenergetic health and improve the metabolic profile of monocytes in individuals with obesity via modulation of the gut microbiota. Moreover, the evaluation of mitochondrial function in monocytes could be used as an indicator of metabolic and inflammatory status, with potential applications in future clinical trials. TRIAL REGISTRATION: This trial was registered with ClinicalTrials.gov (NCT05200468).

IFN-γ stimulates Paneth cell secretion through necroptosis mTORC1 dependent.

Immune mediators affect multiple biological functions of intestinal epithelial cells (IECs) and, like Paneth and Paneth-like cells, play an important role in intestinal epithelial homeostasis. IFN-γ a prototypical proinflammatory cytokine disrupts intestinal epithelial homeostasis. However, the mechanism underlying the process remains unknown. In this study, using in vivo and in vitro models we demonstrate that IFN-γ is spontaneously secreted in the small intestine. Furthermore, we observed that this cytokine stimulates mitochondrial activity, ROS production, and Paneth and Paneth-like cell secretion. Paneth and Paneth-like secretion downstream of IFN-γ, as identified here, is mTORC1 and necroptosis-dependent. Thus, our findings revealed that the pleiotropic function of IFN-γ also includes the regulation of Paneth cell function in the homeostatic gut.

Transient inhibition of sodium-glucose cotransporter 2 after ischemia/reperfusion injury ameliorates chronic kidney disease.

Sodium-glucose cotransporter 2 (SGLT2) inhibitor, dapagliflozin (Dapa), exhibited nephroprotective effects in patients with chronic kidney disease (CKD). We assessed the efficacy of short-term Dapa administration following acute kidney injury (AKI) in preventing CKD. Male Wistar rats were randomly assigned to Sham surgery, bilateral ischemia for 30 minutes (abbreviated as IR), and IR + Dapa groups. Daily treatment with Dapa was initiated just 24 hours after IR and maintained for only 10 days. Initially, rats were euthanized at this point to study early renal repair. After severe AKI, Dapa promptly restored creatinine clearance (CrCl) and significantly reduced renal vascular resistance compared with the IR group. Furthermore, Dapa effectively reversed the mitochondrial abnormalities, including increased fission, altered mitophagy, metabolic dysfunction, and proapoptotic signaling. To study this earlier, another set of rats was studied just 5 days after AKI. Despite persistent renal dysfunction, our data reveal a degree of mitochondrial protection. Remarkably, a 10-day treatment with Dapa demonstrated effectiveness in preventing CKD transition in an independent cohort monitored for 5 months after AKI. This was evidenced by improvements in proteinuria, CrCl, glomerulosclerosis, and fibrosis. Our findings underscore the potential of Dapa in preventing maladaptive repair following AKI, emphasizing the crucial role of early intervention in mitigating AKI long-term consequences.

Revisiting genomes of non-model species with long reads yields new insights into their biology and evolution.

High-quality genomes obtained using long-read data allow not only for a better understanding of heterozygosity levels, repeat content, and more accurate gene annotation and prediction when compared to those obtained with short-read technologies, but also allow to understand haplotype divergence. Advances in long-read sequencing technologies in the last years have made it possible to produce such high-quality assemblies for non-model organisms. This allows us to revisit genomes, which have been problematic to scaffold to chromosome-scale with previous generations of data and assembly software. Nematoda, one of the most diverse and speciose animal phyla within metazoans, remains poorly studied, and many previously assembled genomes are fragmented. Using long reads obtained with Nanopore R10.4.1 and PacBio HiFi, we generated highly contiguous assemblies of a diploid nematode of the Mermithidae family, for which no closely related genomes are available to date, as well as a collapsed assembly and a phased assembly for a triploid nematode from the Panagrolaimidae family. Both genomes had been analysed before, but the fragmented assemblies had scaffold sizes comparable to the length of long reads prior to assembly. Our new assemblies illustrate how long-read technologies allow for a much better representation of species genomes. We are now able to conduct more accurate downstream assays based on more complete gene and transposable element predictions.

Parthenogenomics: Insights on mutation rates and nucleotide diversity in parthenogenetic Panagrolaimus nematodes.

Asexual reproduction is assumed to lead to the accumulation of deleterious mutations, and reduced heterozygosity due to the absence of recombination. Panagrolaimid nematode species display different modes of reproduction. Sexual reproduction with distinct males and females, asexual reproduction through parthenogenesis in the genus Panagrolaimus, and hermaphroditism in Propanagrolaimus. Here, we compared genomic features of free-living nematodes in populations and species isolated from geographically distant regions to study diversity, and genome-wide differentiation under different modes of reproduction. We firstly estimated genome-wide spontaneous mutation rates in a triploid parthenogenetic Panagrolaimus, and a diploid hermaphroditic Propanagrolaimus via long-term mutation accumulation lines. Secondly, we calculated population genetic parameters including nucleotide diversity, and fixation index (F ST) between populations of asexually and sexually reproducing nematodes. Thirdly, we used phylogenetic network methods on sexually and asexually reproducing Panagrolaimus populations to understand evolutionary relationships between them. The estimated mutation rate was slightly lower for the asexual population, as expected for taxa with this reproductive mode. Natural polyploid asexual populations revealed higher nucleotide diversity. Despite their common ancestor, a gene network revealed a high level of genetic differentiation among asexual populations. The elevated heterozygosity found in the triploid parthenogens could be explained by the third genome copy. Given their tendentially lower mutation rates it can be hypothesized that this is part of the mechanism to evade Muller's ratchet. Our findings in parthenogenetic triploid nematode populations seem to challenge common expectations of evolution under asexuality.

Complement alternative pathway determines disease susceptibility and severity in antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis.

Activation of the alternative pathway (AP) of complement is involved in the pathogenesis of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), although the underlying molecular mechanisms are unclear. To gain insight into the role of the AP, common gene variants in CFH/CFHR1-5, CFB, C3 and MCP, and longitudinal determinations of plasma C3, C4, FH, FHR-1, FHR-2, FHR-5, FB, properdin and sC5b-9 levels were analyzed in a Spanish AAV cohort consisting of 102 patients; 54 with active AAV (active cohort) and 48 in remission not receiving immunosuppressants or dialysis therapy (remission cohort). The validation cohort consisted of 100 patients with ANCA-associated glomerulonephritis. Here, we demonstrated that common genetic variants in complement components of the AP are associated with disease susceptibility (CFB32Q/W) or severity of kidney damage in AAV (CFH-H1, CFH1H2 and ΔCFHR3/1). Plasma levels of complement components were significantly different between active and remission cohorts. In longitudinal observations, a high degree of AP activation at diagnosis was associated with worse disease outcome, while high basal FHR-1 levels and lower FH/FHR-1 ratios determined severe forms of kidney associated AAV. These genetic and plasmatic findings were confirmed in the validation cohort. Additionally, autoantibodies against FH and C3 convertase were identified in one and five active patients, respectively. Thus, our study identified key genetic and plasma components of the AP that determine disease susceptibility, prognosis, and severity in AAV. Our data also suggests that balance between FH and FHR-1 is critical and supports FHR-1 as a novel AP-specific therapeutic target in AAV.

Ramon Flour (Brosimum alicastrum Swartz) Ameliorates Hepatic Lipid Accumulation, Induction of AMPK Phosphorylation, and Expression of the Hepatic Antioxidant System in a High-Fat-Diet-Induced Obesity Mouse Model.

Excessive consumption of fat and carbohydrates, together with a decrease in traditional food intake, has been related to obesity and the development of metabolic alterations. Ramon seed is a traditional Mayan food used to obtain Ramon flour (RF) with high biological value in terms of protein, fiber, micronutrients, and bioactive compounds such as polyphenols. However, few studies have evaluated the beneficial effects of RF. Thus, we aimed to determine the metabolic effects of RF consumption on a high-fat-diet-induced obesity mouse model. We divided male BALB/c mice into four groups (n = 5 each group) and fed them for 90 days with the following diets: Control (C): control diet (AIN-93), C + RF: control diet adjusted with 25% RF, HFD: high-fat diet + 5% sugar in water, and HFD + RF: high-fat diet adjusted with 25% RF + 5% sugar in water. The RF prevented the increase in serum total cholesterol (TC) and alanine transaminase (ALT) that occurred in the C and HFD groups. Notably, RF together with HFD increased serum polyphenols and antioxidant activity, and it promoted a decrease in the adipocyte size in white adipose tissue, along with lower hepatic lipid accumulation than in the HFD group. In the liver, the HFD + RF group showed an increase in the expression of ß-oxidation-related genes, and downregulation of the fatty acid synthase (Fas) gene compared with the HFD group. Moreover, the HFD + RF group had increased hepatic phosphorylation of AMP-activated protein kinase (AMPK), along with increased nuclear factor erythroid 2-related factor 2 (NRF2) and superoxide dismutase 2 (SOD2) protein expression compared with the HFD group. Thus, RF may be used as a nutritional strategy to decrease metabolic alterations during obesity.

Amino Acid Catabolism: An Overlooked Area of Metabolism.

Amino acids have been extensively studied in nutrition, mainly as key elements for maintaining optimal protein synthesis in the body as well as precursors of various nitrogen-containing compounds. However, it is now known that amino acid catabolism is an important element for the metabolic control of different biological processes, although it is still a developing field to have a deeper understanding of its biological implications. The mechanisms involved in the regulation of amino acid catabolism now include the contribution of the gut microbiota to amino acid oxidation and metabolite generation in the intestine, the molecular mechanisms of transcriptional control, and the participation of specific miRNAs involved in the regulation of amino acid degrading enzymes. In addition, molecules derived from amino acid catabolism play a role in metabolism as they are used in the epigenetic regulation of many genes. Thus, this review aims to examine the mechanisms of amino acid catabolism and to support the idea that this process is associated with the immune response, abnormalities during obesity, in particular insulin resistance, and the regulation of thermogenesis.

Genistein-mediated thermogenesis and white-to-beige adipocyte differentiation involve transcriptional activation of cAMP response elements in the Ucp1 promoter.

Genistein is an isoflavone present in soybeans and is considered a bioactive compound due to its widely reported biological activity. We have previously shown that intraperitoneal genistein administration and diet supplementation activates the thermogenic program in rats and mice subcutaneous white adipose tissue (scWAT) under multiple environmental cues, including cold exposure and high-fat diet feeding. However, the mechanistic insights of this process were not previously unveiled. Uncoupling protein 1 (UCP1), a mitochondrial membrane polypeptide responsible for dissipating energy into heat, is considered the most relevant thermogenic marker; thus, we aimed to evaluate whether genistein regulates UCP1 transcription. Here we show that genistein administration to thermoneutral-housed mice leads to the appearance of beige adipocyte markers, including a sharp upregulation of UCP1 expression and protein abundance in scWAT. Reporter assays showed an increase in UCP1 promoter activity after genistein stimulation, and in silico analysis revealed the presence of estrogen (ERE) and cAMP (CRE) response elements as putative candidates of genistein activation. Mutation of the CRE but not the ERE reduced genistein-induced promoter activity by 51%. Additionally, in vitro and in vivo ChIP assays demonstrated the binding of CREB to the UCP1 promoter after acute genistein administration. Taken together, these data elucidate the mechanism of genistein-mediated UCP1 induction and confirm its potential applications in managing metabolic disorders.

Astrocytic circadian clock control of energy expenditure by transcriptional stress responses in the ventromedial hypothalamus.

Hypothalamic circuits compute systemic information to control metabolism. Astrocytes residing within the hypothalamus directly sense nutrients and hormones, integrating metabolic information, and modulating neuronal responses. Nevertheless, the role of the astrocytic circadian clock on the control of energy balance remains unclear. We used mice with a targeted ablation of the core-clock gene Bmal1 within Gfap-expressing astrocytes to gain insight on the role played by this transcription factor in astrocytes. While this mutation does not substantially affect the phenotype in mice fed normo-caloric diet, under high-fat diet we unmasked a thermogenic phenotype consisting of increased energy expenditure, and catabolism in brown adipose and overall metabolic improvement consisting of better glycemia control, and body composition. Transcriptomic analysis in the ventromedial hypothalamus revealed an enhanced response to moderate cellular stress, including ER-stress response, unfolded protein response and autophagy. We identified Xbp1 and Atf1 as two key transcription factors enhancing cellular stress responses. Therefore, we unveiled a previously unknown role of the astrocytic circadian clock modulating energy balance through the regulation of cellular stress responses within the VMH.

Time-of-day defines NAD+ efficacy to treat diet-induced metabolic disease by synchronizing the hepatic clock in mice.

The circadian clock is an endogenous time-tracking system that anticipates daily environmental changes. Misalignment of the clock can cause obesity, which is accompanied by reduced levels of the clock-controlled, rhythmic metabolite NAD+. Increasing NAD+ is becoming a therapy for metabolic dysfunction; however, the impact of daily NAD+ fluctuations remains unknown. Here, we demonstrate that time-of-day determines the efficacy of NAD+ treatment for diet-induced metabolic disease in mice. Increasing NAD+ prior to the active phase in obese male mice ameliorated metabolic markers including body weight, glucose and insulin tolerance, hepatic inflammation and nutrient sensing pathways. However, raising NAD+ immediately before the rest phase selectively compromised these responses. Remarkably, timed NAD+ adjusted circadian oscillations of the liver clock until completely inverting its oscillatory phase when increased just before the rest period, resulting in misaligned molecular and behavioral rhythms in male and female mice. Our findings unveil the time-of-day dependence of NAD+-based therapies and support a chronobiology-based approach.

Biomarkers of sequela in adult patients convalescing from COVID-19.

Different biomarkers for SARS-CoV-2 have been linked to detection, diagnosis, treatment, disease progression, and development of new drugs and vaccines. The objective of this research was to evaluate various hematological, biochemicals, immunological, radiological and spirometric parameters in 20 adult patients convalescing from COVID-19 and their possible relationship with the clinical course of the disease. The frequencies of categorical variables were compared using the chi-square and Fisher's exact test. The levels of statistical significance were denoted in each figure legend. Two-dimensional clustering analysis was performed using MeV software from TIGR. The tests with P value of ≤ 0.05 were considered statistically significant. Most of the patients studied presented alterations in dissimilar laboratory, radiological and spirometric parameters, which were related to the clinical evolution of the disease. The results obtained show that certain hematological, biochemical, immunological and radiological parameters can be considered as biomarkers of sequela in adult COVID-19 patients, which allows their stratification, according to the degree of involvement or sequela, into three groups: I (mild degree of involvement or sequela), without lung lesions on computerized axial tomography (CT scan) and high values of IgG, C3 and hemoglobin, II (moderate degree of involvement or sequel), without lung lesions on CT scan, characterized by high levels of CD3+/CD4+ T lymphocytes and the rest of the variables with low values and III (severe degree of involvement or sequela), with lung lesions on CT scan and high values of erythrocyte sedimentation rate, monocytes and neutrophils, associated with lymphopenia and decreased concentrations of IgG and C3.

Integrative systems analysis identifies genetic and dietary modulators of bile acid homeostasis.

Bile acids (BAs) are complex and incompletely understood enterohepatic-derived hormones that control whole-body metabolism. Here, we profiled postprandial BAs in the liver, feces, and plasma of 360 chow- or high-fat-diet-fed BXD male mice and demonstrated that both genetics and diet strongly influence BA abundance, composition, and correlation with metabolic traits. Through an integrated systems approach, we mapped hundreds of quantitative trait loci that modulate BAs and identified both known and unknown regulators of BA homeostasis. In particular, we discovered carboxylesterase 1c (Ces1c) as a genetic determinant of plasma tauroursodeoxycholic acid (TUDCA), a BA species with established disease-preventing actions. The association between Ces1c and plasma TUDCA was validated using data from independent mouse cohorts and a Ces1c knockout mouse model. Collectively, our data are a unique resource to dissect the physiological importance of BAs as determinants of metabolic traits, as underscored by the identification of CES1C as a master regulator of plasma TUDCA levels.

Safety and immunogenicity of the FINLAY-FR-1A vaccine in COVID-19 convalescent participants: an open-label phase 2a and double-blind, randomised, placebo-controlled, phase 2b, seamless, clinical trial.

BACKGROUND: A phase 1, clinical trial to evaluate FINLAY-FR-1A vaccine in COVID-19 convalescent individuals was completed. Here, we report results of the phase 2, clinical trial. METHODS: We studied 450 convalescent participants with a history of asymptomatic, mild, or moderate COVID-19 at the National Institute of Hematology and Immunology and the National Centre for Sexual Education in Havana, Cuba. The study included adults aged 19-78 years who had recovered from COVID-19 and had had a negative PCR test at least 2 months before the initiation of the study. Phase 2 was done sequentially in two stages. The first stage to assess safety comprised an open, non-controlled phase 2a study in participants aged 60-78 years who received a single dose of the FINLAY-FR-1A vaccine (50 µg of recombinant dimeric receptor binding domain [RBD]). The second stage comprised the placebo-controlled, double-blind, phase 2b trial in participants aged 19-78 years, where participants were randomly assigned (4:1) into two groups: an experimental group vaccinated with a single dose of the FINLAY-FR-1A vaccine, and a control (placebo) group injected with vaccine excipient. The primary outcomes were safety, evaluated 28 days after vaccination by the occurrence of serious adverse events in all participants, and successful immune response, assessed by neutralising antibody ELISA, and defined as half-maximal surrogate virus neutralisation titres of 250 or more. Secondary endpoints included vaccine immunogenicity assessed by ELISA anti-RBD and live-virus neutralisation test. All randomly assigned participants were included in the safety analysis (safety population), and immunogenicity was evaluated in participants without study interruptions (per-protocol population). The trial is registered with the Cuban Public Registry of Clinical Trials, RPCEC00000366-En and WHO-ICTRP and is complete. FINDINGS: From April 9, 2021, to April 17, 2021, 663 COVID-19 convalescent participants were enrolled in the study; 213 participants did not meet the selection criteria and 450 volunteers were recruited. 20 participants aged 60-78 years were included in the open, single-group, phase 2a study and 430 participants were randomly assigned to the experimental (n=344) or control groups (n=86) in the phase 2b study of participants aged 19-78 years. 19 (95%) of 20 phase 2a volunteers achieved a successful immune response after vaccination. No vaccine-associated serious adverse events were reported in the whole study population. Minor adverse events were found, the most common being pain at the injection site (105 [29%] of 364 in the intervention group; 13 [15%] of 86 in the placebo group). A successful immune response was found in 289 (81%) of 358 participants 28 days after vaccination. The vaccine elicited a greater than 31-times increase in anti-RBD-IgG antibodies compared with prevaccination rates, and the seroconversion rate was 302 (84%) of 358 on day 28 after vaccination; the geometric mean titres of live-virus neutralisation test increased from 15·4 (95% CI 10·3-23·2) to 400·3 (272·4-588·1) and high response was found against alpha, beta, and delta variants of concern. INTERPRETATION: A single dose of the FINLAY-FR-1A vaccine against SARS-CoV-2 strengthened the pre-existing natural immunity, with excellent safety profile. FUNDING: Cuba's Ministry of Science, Technology, and Environment.

Genistein Stimulation of White Adipose Tissue Thermogenesis Is Partially Dependent on GPR30 in Mice.

SCOPE: Genistein increases whole body energy expenditure by stimulating white adipose tissue (WAT) browning and thermogenesis. G-Coupled receptor GPR30 can mediate some actions of genistein, however, it is not known whether it is involved in the activation of WAT-thermogenesis. Thus, the aim of the study is to determine whether genistein activates thermogenesis coupled to an increase in WAT browning and mitochondrial activity, in GPR30+/+ and GPR30-/- mice. METHODS AND RESULTS: GPR30+/+ and GPR30-/- mice are fed control or high fat sucrose diets containing or not genistein for 8 weeks. Body weight and composition, energy expenditure, glucose tolerance, and browning markers in WAT, and oxygen consumption rate, 3', 5'-cyclic adenosine monophosphate (cAMP) concentration and browning markers in adipocytes are evaluated. Genistein consumption reduces body weight and fat mass gain in a different extent in both genotypes, however, energy expenditure is lower in GPR30-/- compared to GPR30+/+ mice, accompanied by a reduction in browning markers, maximal mitochondrial respiration, cAMP concentration, and browning markers in cultured adipocytes from GPR30-/- mice. Genistein improves glucose tolerance in GPR30+/+ , but this is partially observed in GPR30-/- mice. CONCLUSION: The results show that GPR30 partially mediates genistein stimulation of WAT thermogenesis and the improvement of glucose tolerance.

A single dose of SARS-CoV-2 FINLAY-FR-1A vaccine enhances neutralization response in COVID-19 convalescents, with a very good safety profile: An open-label phase 1 clinical trial.

BACKGROUND: As a first step towards a vaccine protecting COVID-19 convalescents from reinfection, we evaluated FINLAY-FR-1A vaccine in a clinical trial. METHODS: Thirty COVID-19 convalescents aged 22-57 years were studied: convalescents of mild COVID-19, asymptomatic convalescents, both with PCR-positive at the moment of diagnosis; and individuals with subclinical infection detected by viral-specific IgG. They received a single intramuscular injection of the FINLAY-FR-1A vaccine (50 µg of the recombinant dimeric receptor binding domain). The primary outcomes were safety and reactogenicity, assessed over 28 days after vaccination. The secondary outcome was vaccine immunogenicity. Humoral response at baseline and following vaccination was evaluated by ELISA and live-virus neutralization test. The effector T cellular response was also assessed. Cuban Public Registry of Clinical Trials, WHO-ICTRP: https://rpcec.sld.cu/en/trials/RPCEC00000349-En. FINDINGS: No serious adverse events were reported. Minor adverse events were found, the most common, local pain: 3 (10%) and redness: 2 (6·7%). The vaccine elicited a >21 fold increase in IgG anti-RBD antibodies 28 days after vaccination. The median of inhibitory antibody titres (94·0%) was three times greater than that of the COVID-19 convalescent panel. Virus neutralization titres higher than 1:160 were found in 24 (80%) participants. There was also an increase in RBD-specific T cells producing IFN-γ and TNF-α. INTERPRETATION: A single dose of the FINLAY-FR-1A vaccine against SARS-CoV-2 was an efficient booster of pre-existing natural immunity, with excellent safety profile. FUNDING: Partial funding for this study was received from the Project-2020-20, Fondo de Ciencia e Innovación (FONCI), Ministry of Science, Technology and the Environment, Cuba.   RESUMEN. ANTECEDENTES: Como un primer paso hacia una vacuna que proteja a los convalecientes de COVID-19 de la reinfección, evaluamos la vacuna FINLAY-FR-1A en un ensayo clínico. MÉTODOS: Se estudiaron treinta convalecientes de COVID-19 de 22 a 57 años: convalecientes de COVID-19 leve y convalecientes asintomáticos, ambos con prueba PCR positiva al momento del diagnóstico; e individuos con infección subclínica detectada por IgG específica viral. Los participantes recibieron una dosis única por vía intramuscular de la vacuna FINLAY-FR-1A (50 µg del dominio de unión al receptor recombinante dimérico del SARS CoV-2). Las variables de medida primarias fueron la seguridad y la reactogenicidad, evaluadas durante 28 días después de la vacunación. La variable secundaria, la inmunogenicidad. La respuesta humoral, al inicio del estudio y después de la vacunación, se evaluó por ELISA y mediante la prueba de neutralización del virus vivo. También se evaluó la respuesta de células T efectoras. Registro Público Cubano de Ensayos Clínicos, WHO-ICTRP: https://rpcec.sld.cu/en/trials/RPCEC00000349-En. RESULTADOS: No se reportaron eventos adversos graves. Se encontraron eventos adversos leves, los más comunes, dolor local: 3 (10%) y enrojecimiento: 2 (6·7%). La vacuna estimuló un incremento >21 veces de los anticuerpos IgG anti-RBD 28 días después de la vacunación. La mediana de los títulos de anticuerpos inhibidores (94·0%) fue aproximadamente tres veces mayor que la del panel de convalecientes de COVID-19. Se encontraron títulos de neutralización viral superiores a 1:160 en 24 (80%) de los participantes. También hubo un aumento en las células T específicas de RBD que producen IFN-γ y TNF-α. INTERPRETACIÓN: Una sola dosis de la vacuna FINLAY-FR-1A contra el SARS-CoV-2 reforzó eficazmente la inmunidad natural preexistente, con un excelente perfil de seguridad. FINANCIAMIENTO: Se recibió un financiamiento parcial del Proyecto-2020-20, Fondo de Ciencia e Innovación (FONCI), Ministerio de Ciencia, Tecnología y Medio Ambiente, Cuba.

Dietary bioactive compounds as modulators of mitochondrial function.

The increase in incidence and prevalence of metabolic diseases, such as diabetes, obesity, and metabolic syndrome, is a health problem worldwide. Nutritional strategies that can impact on mitochondrial activity represent a novel and effective option to modulate energy expenditure and energetic metabolism in cells and tissues and could be used as adjuvant treatments for metabolic-associated disorders. Dietary bioactive compounds also known as "food bioactives" have proven to exert multiple health benefits and counteract metabolic alterations. In the last years, it has been consistently reported that the modulation of mitochondrial function represents one of the mechanisms behind the bioactive compounds-dependent health improvements. In this review, we focus on gathering, summarizing, and discussing the evidence that supports the effect of dietary bioactive compounds on mitochondrial activity and the relation of these effects in the pathological context. Despite the evidence presented here on in vivo and in vitro effects, more studies are needed to determine their effectiveness in humans.

Central anorexigenic actions of bile acids are mediated by TGR5.

Bile acids (BAs) are signalling molecules that mediate various cellular responses in both physiological and pathological processes. Several studies report that BAs can be detected in the brain1, yet their physiological role in the central nervous system is still largely unknown. Here we show that postprandial BAs can reach the brain and activate a negative-feedback loop controlling satiety in response to physiological feeding via TGR5, a G-protein-coupled receptor activated by multiple conjugated and unconjugated BAs2 and an established regulator of peripheral metabolism3-8. Notably, peripheral or central administration of a BA mix or a TGR5-specific BA mimetic (INT-777) exerted an anorexigenic effect in wild-type mice, while whole-body, neuron-specific or agouti-related peptide neuronal TGR5 deletion caused a significant increase in food intake. Accordingly, orexigenic peptide expression and secretion were reduced after short-term TGR5 activation. In vitro studies demonstrated that activation of the Rho-ROCK-actin-remodelling pathway decreases orexigenic agouti-related peptide/neuropeptide Y (AgRP/NPY) release in a TGR5-dependent manner. Taken together, these data identify a signalling cascade by which BAs exert acute effects at the transition between fasting and feeding and prime the switch towards satiety, unveiling a previously unrecognized role of physiological feedback mediated by BAs in the central nervous system.

SIRT7 modulates the stability and activity of the renal K-Cl cotransporter KCC4 through deacetylation.

SIRT7 is a NAD+ -dependent deacetylase that controls important aspects of metabolism, cancer, and bone formation. However, the molecular targets and functions of SIRT7 in the kidney are currently unknown. In silico analysis of kidney transcripts of the BXD murine genetic reference population revealed a positive correlation between Sirt7 and Slc12a7 mRNA expression, suggesting a link between the corresponding proteins that these transcripts encode, SIRT7, and the K-Cl cotransporter KCC4, respectively. Here, we find that protein levels and activity of heterologously expressed KCC4 are significantly modulated depending on its acetylation status in Xenopus laevis oocytes. Moreover, SIRT7 interacts with KCC4 in a NAD+ -dependent manner and increases its stability and activity in HEK293 cells. Interestingly, metabolic acidosis increases SIRT7 expression in kidney, as occurs with KCC4. In contrast, total SIRT7-deficient mice present lower KCC4 expression and an exacerbated metabolic acidosis than wild-type mice during an ammonium chloride challenge. Altogether, our data suggest that SIRT7 interacts with, stabilizes and modulates KCC4 activity through deacetylation, and reveals a novel role for SIRT7 in renal physiology.