RESUMEN
The most recent Ebola virus outbreak in West Africa, which was unprecedented in the number of cases and fatalities, geographic distribution, and number of nations affected, highlights the need for safe, effective, and readily available antiviral agents for treatment and prevention of acute Ebola virus (EBOV) disease (EVD) or sequelae. No antiviral therapeutics have yet received regulatory approval or demonstrated clinical efficacy. Here we report the discovery of a novel small molecule GS-5734, a monophosphoramidate prodrug of an adenosine analogue, with antiviral activity against EBOV. GS-5734 exhibits antiviral activity against multiple variants of EBOV and other filoviruses in cell-based assays. The pharmacologically active nucleoside triphosphate (NTP) is efficiently formed in multiple human cell types incubated with GS-5734 in vitro, and the NTP acts as an alternative substrate and RNA-chain terminator in primer-extension assays using a surrogate respiratory syncytial virus RNA polymerase. Intravenous administration of GS-5734 to nonhuman primates resulted in persistent NTP levels in peripheral blood mononuclear cells (half-life, 14 h) and distribution to sanctuary sites for viral replication including testes, eyes, and brain. In a rhesus monkey model of EVD, once-daily intravenous administration of 10 mg kg(-1) GS-5734 for 12 days resulted in profound suppression of EBOV replication and protected 100% of EBOV-infected animals against lethal disease, ameliorating clinical disease signs and pathophysiological markers, even when treatments were initiated three days after virus exposure when systemic viral RNA was detected in two out of six treated animals. These results show the first substantive post-exposure protection by a small-molecule antiviral compound against EBOV in nonhuman primates. The broad-spectrum antiviral activity of GS-5734 in vitro against other pathogenic RNA viruses, including filoviruses, arenaviruses, and coronaviruses, suggests the potential for wider medical use. GS-5734 is amenable to large-scale manufacturing, and clinical studies investigating the drug safety and pharmacokinetics are ongoing.
Asunto(s)
Alanina/análogos & derivados , Antivirales/uso terapéutico , Fiebre Hemorrágica Ebola/tratamiento farmacológico , Macaca mulatta/virología , Ribonucleótidos/uso terapéutico , Adenosina Monofosfato/análogos & derivados , Alanina/farmacocinética , Alanina/farmacología , Alanina/uso terapéutico , Secuencia de Aminoácidos , Animales , Antivirales/farmacocinética , Antivirales/farmacología , Línea Celular Tumoral , Ebolavirus/efectos de los fármacos , Femenino , Células HeLa , Fiebre Hemorrágica Ebola/prevención & control , Humanos , Masculino , Datos de Secuencia Molecular , Especificidad de Órganos , Profármacos/farmacocinética , Profármacos/farmacología , Profármacos/uso terapéutico , Ribonucleótidos/farmacocinética , Ribonucleótidos/farmacologíaRESUMEN
Remdesivir (RDV, GS-5734), the first FDA-approved antiviral for the treatment of COVID-19, is a single diastereomer monophosphoramidate prodrug of an adenosine analogue. It is intracellularly metabolized into the active triphosphate form, which in turn acts as a potent and selective inhibitor of multiple viral RNA polymerases. RDV has broad-spectrum activity against members of the coronavirus family, such as SARS-CoV-2, SARS-CoV, and MERS-CoV, as well as filoviruses and paramyxoviruses. To assess the potential for off-target toxicity, RDV was evaluated in a set of cellular and biochemical assays. Cytotoxicity was evaluated in a set of relevant human cell lines and primary cells. In addition, RDV was evaluated for mitochondrial toxicity under aerobic and anaerobic metabolic conditions, and for the effects on mitochondrial DNA content, mitochondrial protein synthesis, cellular respiration, and induction of reactive oxygen species. Last, the active 5'-triphosphate metabolite of RDV, GS-443902, was evaluated for potential interaction with human DNA and RNA polymerases. Among all of the human cells tested under 5 to 14 days of continuous exposure, the 50% cytotoxic concentration (CC50) values of RDV ranged from 1.7 to >20 µM, resulting in selectivity indices (SI, CC50/EC50) from >170 to 20,000, with respect to RDV anti-SARS-CoV-2 activity (50% effective concentration [EC50] of 9.9 nM in human airway epithelial cells). Overall, the cellular and biochemical assays demonstrated a low potential for RDV to elicit off-target toxicity, including mitochondria-specific toxicity, consistent with the reported clinical safety profile.
Asunto(s)
Adenosina Monofosfato/análogos & derivados , Alanina/análogos & derivados , Antivirales/farmacología , Tratamiento Farmacológico de COVID-19 , SARS-CoV-2/efectos de los fármacos , Adenosina Monofosfato/química , Adenosina Monofosfato/farmacología , Alanina/química , Alanina/farmacología , Antivirales/química , COVID-19/virología , Línea Celular , Células Epiteliales/efectos de los fármacos , Humanos , Concentración 50 Inhibidora , Mitocondrias/efectos de los fármacos , Cultivo Primario de CélulasRESUMEN
BACKGROUND: Presatovir is an oral respiratory syncytial virus (RSV) fusion inhibitor targeting RSV F protein. In a double-blind, placebo-controlled study in healthy adults experimentally infected with RSV (Memphis-37b), presatovir significantly reduced viral load and clinical disease severity in a dose-dependent manner. METHODS: Viral RNA from nasal wash samples was amplified and the F gene sequenced to monitor presatovir resistance. Effects of identified amino acid substitutions on in vitro susceptibility to presatovir, viral fitness, and clinical outcome were assessed. RESULTS: Twenty-eight treatment-emergent F substitutions were identified. Of these, 26 were tested in vitro; 2 were not due to lack of recombinant virus recovery. Ten substitutions did not affect presatovir susceptibility, and 16 substitutions reduced RSV susceptibility to presatovir (2.9- to 410-fold). No substitutions altered RSV susceptibility to palivizumab or ribavirin. Frequency of phenotypically resistant substitutions was higher with regimens containing lower presatovir dose and shorter treatment duration. Participants with phenotypic presatovir resistance had significantly higher nasal viral load area under the curve relative to those without, but substitutions did not significantly affect peak viral load or clinical manifestations of RSV disease. CONCLUSIONS: Emergence of presatovir-resistant RSV occurred during therapy but did not significantly affect clinical efficacy in participants with experimental RSV infection.
Asunto(s)
Indazoles/uso terapéutico , Infecciones por Virus Sincitial Respiratorio/tratamiento farmacológico , Virus Sincitiales Respiratorios/efectos de los fármacos , Sulfonamidas/uso terapéutico , Inhibidores de Proteínas Virales de Fusión/uso terapéutico , Adolescente , Adulto , Sustitución de Aminoácidos , Relación Dosis-Respuesta a Droga , Método Doble Ciego , Farmacorresistencia Viral/genética , Humanos , Persona de Mediana Edad , Virus Sincitiales Respiratorios/genética , Carga Viral/efectos de los fármacos , Adulto JovenRESUMEN
OBJECTIVE: Life-long maintenance of brain health is important for the prevention of cognitive impairment in older age. Low-grade peripheral inflammation associated with excess visceral fat (VF) may influence brain structure and function. Here we examined (i) if this type of inflammation is associated with altered white-matter (WM) microstructure and lower cognitive functioning in adolescents, and (ii) if recently identified circulating glycerophosphocholines (GPCs) can index this type of inflammation and associated variations in WM microstructure and cognitive functioning. SUBJECTS: We studied a community-based sample of 872 adolescents (12-18 years, 48% males) in whom we assessed VF and WM microstructure with magnetic resonance imaging, processing speed with cognitive testing, serum C-reactive protein (CRP, a common marker of peripheral inflammation) with a high-sensitivity assay, and serum levels of a panel of 64 GPCs with advanced mass spectrometry. RESULTS: VF was associated with CRP, and CRP in turn was associated with "altered" WM microstructure and lower processing speed (all p < 0.003). Further, "altered" WM microstructure was associated with lower processing speed (p < 0.0001). Of all 64 tested GPCs, 4 were associated with both VF and CRP (at Bonferroni corrected p < 0.0004). One of them, PC16:0/2:0, was also associated with WM microstructure (p < 0.0001) and processing speed (p = 0.0003), and mediated the directed associations between VF and both WM microstructure (p < 0.0001) and processing speed (p = 0.02). As a mediator, PC16:0/2:0 explained 21% of shared variance between VF and WM microstructure, and 22% of shared variance between VF and processing speed. Similar associations were observed in an auxiliary study of 80 middle-aged adults. CONCLUSIONS: Our results show that VF-related peripheral inflammation is associated with "altered" WM microstructure and lower cognitive functioning already in adolescents, and a specific circulating GPC may be a new molecule indexing this VF-related peripheral inflammation and its influences on brain structure and function.
Asunto(s)
Encéfalo/patología , Glicerofosfatos/sangre , Inflamación/fisiopatología , Grasa Intraabdominal/patología , Obesidad Infantil/fisiopatología , Adiposidad , Adolescente , Encéfalo/diagnóstico por imagen , Estudios Transversales , Femenino , Humanos , Inflamación/etiología , Imagen por Resonancia Magnética , Masculino , Neuroimagen , Obesidad Infantil/complicaciones , Obesidad Infantil/diagnóstico por imagenRESUMEN
Age-related decreases in cortical thickness observed during adolescence may be related to fluctuations in sex and stress hormones. We examine this possibility by relating inter-regional variations in age-related cortical thinning (data from the Saguenay Youth Study) to inter-regional variations in expression levels of relevant genes (data from the Allen Human Brain Atlas); we focus on genes coding for glucocorticoid receptor (NR3C1), androgen receptor (AR), progesterone receptor (PGR), and estrogen receptors (ESR1 and ESR2). Across 34 cortical regions (Desikan-Killiany parcellation), age-related cortical thinning varied as a function of mRNA expression levels of NR3C1 in males (R2 = 0.46) and females (R2 = 0.30) and AR in males only (R2 = 0.25). Cortical thinning did not vary as a function of expression levels of PGR, ESR1, or ESR2 in either sex; this might be due to the observed low consistency of expression profiles of these 3 genes across donors. Inter-regional levels of the NR3C1 and AR expression interacted with each other vis-à-vis cortical thinning: age-related cortical thinning varied as a function of NR3C1 mRNA expression in brain regions with low (males: R2 = 0.64; females: R2 = 0.58) but not high (males: R2 = 0.0045; females: R2 = 0.15) levels of AR mRNA expression. These results suggest that glucocorticoid and androgen receptors contribute to cortical maturation during adolescence.
Asunto(s)
Envejecimiento/fisiología , Corteza Cerebral/fisiología , Expresión Génica/fisiología , Adolescente , Corteza Cerebral/diagnóstico por imagen , Niño , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Masculino , ARN Mensajero/metabolismo , Receptores Androgénicos/genética , Receptores Androgénicos/metabolismo , Receptores de Estrógenos/genética , Receptores de Estrógenos/metabolismo , Receptores de Glucocorticoides/genética , Receptores de Glucocorticoides/metabolismo , Receptores de Progesterona/genética , Receptores de Progesterona/metabolismo , Factores Sexuales , TranscriptomaRESUMEN
Neurobiological underpinnings of cortical thickness in the human brain are largely unknown. Here we use cell-type-specific gene markers to evaluate the contribution of 9 neural cell-types in explaining inter-regional variations in cortical thickness and age-related cortical thinning in the adolescent brain. Gene-expression data were derived from the Allen Human Brain Atlas (and validated using the BrainSpan Atlas). Values of cortical thickness/thinning were obtained with magnetic resonance imaging in a sample of 987 adolescents. We show that inter-regional profiles in cortical thickness relate to those in the expression of genes marking CA1 pyramidal cells, astrocytes, and microglia; taken together, the 3 cell types explain 70% of regional variation in cortical thickness. We also show that inter-regional profiles in cortical thinning relate to those in the expression of genes marking CA1 and S1 pyramidal cells, astrocytes and microglia. Using Gene Ontology analysis, we demonstrate that the difference in the contribution of CA1 and S1 pyramidal cells may relate to biological processes such as neuronal plasticity and potassium channel activity, respectively. This "virtual histology" approach (scripts provided) can be used to examine neurobiological underpinnings of cortical profiles associated with development, aging, and various disorders.
Asunto(s)
Corteza Cerebral/citología , Corteza Cerebral/crecimiento & desarrollo , Neuroglía/citología , Neuronas/citología , Adolescente , Femenino , Humanos , Masculino , Tamaño de los Órganos , TranscriptomaRESUMEN
BACKGROUND: Glycerophosphocholine (GPC) metabolites modulate atherosclerosis and thus risk for cardiovascular disease (CVD). Preclinical CVD may start during adolescence. Here, we used targeted serum lipidomics to identify a new panel of GPCs, and tested whether any of these GPCs are associated, in adolescence, with classical risk factors of CVD, namely excess visceral fat (VF), elevated blood pressure, insulin resistance, and atherogenic dyslipidemia. METHODS: We studied a population-based sample of 990 adolescents (12-18 years, 48% male), as part of the Saguenay Youth Study. Using liquid chromatography-electrospray ionization-mass spectrometry, we identified 69 serum GPCs within the 450 to 680 m/z range. We measured VF with MRI. RESULTS: We identified several novel GPCs that were associated with multiple CVD risk factors. Most significantly, PC16:0/2:0 was negatively associated with VF (P=1.4×10-19), blood pressure (P=7.7×10-5), and fasting triacylglycerols (P=9.0×10-5), and PC14:1/0:0 was positively associated with VF (P=3.0×10-7), fasting insulin (P=5.4×10-32), and triacylglycerols (P=1.4×10-29). The Sobel test of mediation revealed that both GPCs mediated their respective relations between VF (as a potential primary exposure) and CVD risk factors (as outcomes, P values<1.3×10-3). Furthermore, a GPC shown recently to predict incident coronary heart disease in older adults, PC18:2/0:0, was associated with several CVD risk factors in adolescents; these associations were less strong than those with the newly identified GPCs. CONCLUSIONS: We identified novel GPCs strongly associated with multiple CVD risk factors in adolescents. These GPCs may be sensitive indicators of obesity-related risk for CVD outcomes in adults, and may improve biological understanding of CVD risk.
Asunto(s)
Enfermedades Cardiovasculares/etiología , Glicerofosfatos/efectos adversos , Adolescente , Enfermedades Cardiovasculares/sangre , Niño , Estudios de Cohortes , Femenino , Humanos , Masculino , Factores de RiesgoRESUMEN
Ledipasvir (LDV; GS-5885), a component of Harvoni (a fixed-dose combination of LDV with sofosbuvir [SOF]), is approved to treat chronic hepatitis C virus (HCV) infection. Here, we report key preclinical antiviral properties of LDV, including in vitro potency, in vitro resistance profile, and activity in combination with other anti-HCV agents. LDV has picomolar antiviral activity against genotype 1a and genotype 1b replicons with 50% effective concentration (EC50) values of 0.031 nM and 0.004 nM, respectively. LDV is also active against HCV genotypes 4a, 4d, 5a, and 6a with EC50 values of 0.11 to 1.1 nM. LDV has relatively less in vitro antiviral activity against genotypes 2a, 2b, 3a, and 6e, with EC50 values of 16 to 530 nM. In vitro resistance selection with LDV identified the single Y93H and Q30E resistance-associated variants (RAVs) in the NS5A gene; these RAVs were also observed in patients after a 3-day monotherapy treatment. In vitro antiviral combination studies indicate that LDV has additive to moderately synergistic antiviral activity when combined with other classes of HCV direct-acting antiviral (DAA) agents, including NS3/4A protease inhibitors and the nucleotide NS5B polymerase inhibitor SOF. Furthermore, LDV is active against known NS3 protease and NS5B polymerase inhibitor RAVs with EC50 values equivalent to those for the wild type.
Asunto(s)
Antivirales/farmacología , Bencimidazoles/farmacología , Fluorenos/farmacología , Hepacivirus/efectos de los fármacos , Hepatitis C Crónica/tratamiento farmacológico , Proteínas no Estructurales Virales/antagonistas & inhibidores , Proteínas Portadoras/antagonistas & inhibidores , Línea Celular Tumoral , Combinación de Medicamentos , Farmacorresistencia Viral/genética , Sinergismo Farmacológico , Genotipo , Células HeLa , Hepacivirus/genética , Humanos , Péptidos y Proteínas de Señalización Intracelular , Pruebas de Sensibilidad Microbiana , Sofosbuvir/farmacologíaRESUMEN
Toxicity has emerged during the clinical development of many but not all nucleotide inhibitors (NI) of hepatitis C virus (HCV). To better understand the mechanism for adverse events, clinically relevant HCV NI were characterized in biochemical and cellular assays, including assays of decreased viability in multiple cell lines and primary cells, interaction with human DNA and RNA polymerases, and inhibition of mitochondrial protein synthesis and respiration. NI that were incorporated by the mitochondrial RNA polymerase (PolRMT) inhibited mitochondrial protein synthesis and showed a corresponding decrease in mitochondrial oxygen consumption in cells. The nucleoside released by the prodrug balapiravir (R1626), 4'-azido cytidine, was a highly selective inhibitor of mitochondrial RNA transcription. The nucleotide prodrug of 2'-C-methyl guanosine, BMS-986094, showed a primary effect on mitochondrial function at submicromolar concentrations, followed by general cytotoxicity. In contrast, NI containing multiple ribose modifications, including the active forms of mericitabine and sofosbuvir, were poor substrates for PolRMT and did not show mitochondrial toxicity in cells. In general, these studies identified the prostate cell line PC-3 as more than an order of magnitude more sensitive to mitochondrial toxicity than the commonly used HepG2 cells. In conclusion, analogous to the role of mitochondrial DNA polymerase gamma in toxicity caused by some 2'-deoxynucleotide analogs, there is an association between HCV NI that interact with PolRMT and the observation of adverse events. More broadly applied, the sensitive methods for detecting mitochondrial toxicity described here may help in the identification of mitochondrial toxicity prior to clinical testing.
Asunto(s)
Antivirales/farmacología , ARN Polimerasas Dirigidas por ADN/efectos de los fármacos , Hepacivirus/efectos de los fármacos , Hepatitis C Crónica/tratamiento farmacológico , Mitocondrias/efectos de los fármacos , Línea Celular , ADN Polimerasa gamma , ADN Polimerasa Dirigida por ADN/genética , ARN Polimerasas Dirigidas por ADN/genética , Desoxicitidina/análogos & derivados , Desoxicitidina/farmacología , Guanosina Monofosfato/análogos & derivados , Guanosina Monofosfato/farmacología , Humanos , Mitocondrias/genética , Mitocondrias/metabolismo , Nucleósidos/farmacología , Consumo de Oxígeno/efectos de los fármacos , Biosíntesis de Proteínas/efectos de los fármacos , ARN/genética , ARN Mitocondrial , Sofosbuvir/farmacología , Transcripción Genética/efectos de los fármacos , Transcripción Genética/genética , Replicación Viral/efectos de los fármacosRESUMEN
OBJECTIVE: To assess body dissatisfaction among children between 9 and 14 years of age and to examine factors (age, sex, body mass index, perceived shape, and self-esteem) associated with wanting a thinner or a larger shape. STUDY DESIGN: Through at-school questionnaires, 1515 preadolescent children (51.2% girls) were asked to fill out the Culture Free Self-Esteem Inventory and the Contour Drawing Rating Scale (body dissatisfaction). Trained assessors then weighed and measured the students individually. RESULTS: Overall, 50.5% of girls wanted a thinner shape compared with 35.9% of boys. More boys wanted a larger shape compared with girls (21.1% vs 7.2%). Most of the preadolescents who were overweight or obese were unsatisfied whereas 58.0% of girls and 41.6% of boys who were underweight were satisfied with their body. Results of a multinomial logistic regression revealed that age, sex, body mass index, perceived shape, and self-esteem were significant correlates of the 4 body dissatisfaction contrasts (wanting a slightly thinner, much thinner, slightly larger, and much larger shape) and explained 50% of the variance. An interaction between sex and perceived shape was found, revealing that girls who perceived themselves as having a larger shape were more likely to desire a thinner shape than boys. CONCLUSIONS: The high prevalence rate of body dissatisfaction among children suggests that current approaches in our society to prevent problems related to body image must be improved. The different results between girls and boys highlight the need to take into account sex differences when designing prevention programs that aim to decrease body dissatisfaction.
Asunto(s)
Imagen Corporal , Peso Corporal , Sobrepeso/epidemiología , Obesidad Infantil/epidemiología , Autoimagen , Delgadez/epidemiología , Adolescente , Índice de Masa Corporal , Niño , Femenino , Humanos , Modelos Logísticos , Masculino , Sobrepeso/psicología , Obesidad Infantil/psicología , Satisfacción Personal , Prevalencia , Quebec , Encuestas y Cuestionarios , Delgadez/psicologíaRESUMEN
Distinct differences in the human voice emerge during adolescence, with males producing deeper and more resonant voices than females by the end of sexual maturation. Using magnetic resonance images of heads and voice recordings obtained in 532 typically developing adolescents, we investigate what might be the drivers of this change in voice, and the subjective judgment of the voice "maleness" and "femaleness". We show clear sex differences in the morphology of voice-related structures during adolescence, with males displaying strong associations between age (and puberty) and both vocal-fold and vocal-tract length; this was not the case in female adolescents. At the same time, males (compared with females) display stronger associations between age (and puberty) with both fundamental frequency and formant position. In males, vocal morphology was a mediator in the relationship between bioavailable testosterone and acoustic indices. Subjective judgment of the voice sex could be predicted by the morphological and acoustic parameters in males only: the length of vocal folds and its acoustic counterpart, fundamental frequency, is a larger predictor of subjective "maleness" of a voice than vocal-tract length and formant position.
Asunto(s)
Desarrollo del Adolescente/fisiología , Acústica del Lenguaje , Pliegues Vocales/anatomía & histología , Voz/fisiología , Adolescente , Factores de Edad , Femenino , Humanos , Masculino , Caracteres Sexuales , Maduración SexualRESUMEN
Genetic variations in fat mass- and obesity (FTO)-associated gene, a well-replicated gene locus of obesity, appear to be associated also with reduced regional brain volumes in elderly. Here, we examined whether FTO is associated with total brain volume in adolescence, thus exploring possible developmental effects of FTO. We studied a population-based sample of 598 adolescents recruited from the French Canadian founder population in whom we measured brain volume by magnetic resonance imaging. Total fat mass was assessed with bioimpedance and body mass index was determined with anthropometry. Genotype-phenotype associations were tested with Merlin under an additive model. We found that the G allele of FTO (rs9930333) was associated with higher total body fat [TBF (P = 0.002) and lower brain volume (P = 0.005)]. The same allele was also associated with higher lean body mass (P = 0.03) and no difference in height (P = 0.99). Principal component analysis identified a shared inverse variance between the brain volume and TBF, which was associated with FTO at P = 5.5 × 10(-6). These results were replicated in two independent samples of 413 and 718 adolescents, and in a meta-analysis of all three samples (n = 1729 adolescents), FTO was associated with this shared inverse variance at P = 1.3 × 10(-9). Co-expression networks analysis supported the possibility that the underlying FTO effects may occur during embryogenesis. In conclusion, FTO is associated with shared inverse variance between body adiposity and brain volume, suggesting that this gene may exert inverse effects on adipose and brain tissues. Given the completion of the overall brain growth in early childhood, these effects may have their origins during early development.
Asunto(s)
Encéfalo/anatomía & histología , Obesidad/genética , Proteínas/genética , Tejido Adiposo/metabolismo , Adiposidad/genética , Adolescente , Dioxigenasa FTO Dependiente de Alfa-Cetoglutarato , Antropometría , Índice de Masa Corporal , Encéfalo/metabolismo , Femenino , Predisposición Genética a la Enfermedad , Humanos , Masculino , Obesidad/metabolismo , Proteínas/metabolismoRESUMEN
Respiratory syncytial virus (RSV) is a leading cause of lower respiratory tract infections in infants and young children. In addition, RSV causes significant morbidity and mortality in hospitalized elderly and immunocompromised patients. Currently, only palivizumab, a monoclonal antibody against the RSV fusion (F) protein, and inhaled ribavirin are approved for the prophylactic and therapeutic treatment of RSV, respectively. Therefore, there is a clinical need for safe and effective therapeutic agents for RSV infections. GS-5806, discovered via chemical optimization of a hit from a high-throughput antiviral-screening campaign, selectively inhibits a diverse set of 75 RSV subtype A and B clinical isolates (mean 50% effective concentration [EC50] = 0.43 nM). The compound maintained potency in primary human airway epithelial cells and exhibited low cytotoxicity in human cell lines and primary cell cultures (selectivity > 23,000-fold). Time-of-addition and temperature shift studies demonstrated that GS-5806 does not block RSV attachment to cells but interferes with virus entry. Follow-up experiments showed potent inhibition of RSV F-mediated cell-to-cell fusion. RSV A and B variants resistant to GS-5806, due to mutations in F protein (RSV A, L138F or F140L/N517I, and RSV B, F488L or F488S), were isolated and showed cross-resistance to other RSV fusion inhibitors, such as VP-14637, but remained fully sensitive to palivizumab and ribavirin. In summary, GS-5806 is a potent and selective RSV fusion inhibitor with antiviral activity against a diverse set of RSV clinical isolates. The compound is currently under clinical investigation for the treatment of RSV infection in pediatric, immunocompromised, and elderly patients.
Asunto(s)
Antivirales/farmacología , Pirazoles/farmacología , Virus Sincitial Respiratorio Humano/efectos de los fármacos , Sulfonamidas/farmacología , Bronquios/citología , Bronquios/virología , Fusión Celular , Línea Celular , Evaluación Preclínica de Medicamentos/métodos , Farmacorresistencia Viral/efectos de los fármacos , Farmacorresistencia Viral/genética , Humanos , Indazoles , Infecciones por Virus Sincitial Respiratorio/tratamiento farmacológico , Infecciones por Virus Sincitial Respiratorio/virología , Virus Sincitial Respiratorio Humano/genética , Virus Sincitial Respiratorio Humano/aislamiento & purificación , Virus Sincitial Respiratorio Humano/patogenicidad , Internalización del Virus/efectos de los fármacosRESUMEN
Respiratory syncytial virus (RSV) is the leading cause of bronchiolitis and pneumonia in infants. Effective treatment for RSV infection is a significant unmet medical need. While new RSV therapeutics are now in development, there are very few animal models that mimic the pathogenesis of human RSV, making it difficult to evaluate new disease interventions. Experimental infection of Holstein calves with bovine RSV (bRSV) causes a severe respiratory infection that is similar to human RSV infection, providing a relevant model for testing novel therapeutic agents. In this model, viral load is readily detected in nasal secretions by quantitative real-time PCR (qRT-PCR), and cumulative symptom scoring together with histopathology evaluations of infected tissue allow for the assessment of disease severity. The bovine RSV model was used to evaluate the antiviral activity of an RSV fusion inhibitor, GS1, which blocks virus entry by inhibiting the fusion of the viral envelope with the host cell membrane. The efficacy of GS1, a close structural analog of GS-5806 that is being developed to treat RSV infection in humans was evaluated in two randomized, blind, placebo-controlled studies in bRSV-infected calves. Intravenous administration of GS1 at 4 mg/kg of body weight/day for 7 days starting 24 h or 72 h postinoculation provided clear therapeutic benefit by reducing the viral load, disease symptom score, respiration rate, and lung pathology associated with bRSV infection. These data support the use of the bovine RSV model for evaluation of experimental therapeutics for treatment of RSV.
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Antivirales/farmacología , Infecciones por Virus Sincitial Respiratorio/tratamiento farmacológico , Virus Sincitial Respiratorio Bovino/efectos de los fármacos , Animales , Bronquiolitis/tratamiento farmacológico , Bronquiolitis/virología , Bovinos , Enfermedades de los Bovinos/tratamiento farmacológico , Enfermedades de los Bovinos/patología , Enfermedades de los Bovinos/virología , Línea Celular , Membrana Celular/patología , Membrana Celular/virología , Método Doble Ciego , Humanos , Indazoles , Pulmón/patología , Pulmón/virología , Masculino , Pirazoles/farmacología , Infecciones por Virus Sincitial Respiratorio/patología , Virus Sincitial Respiratorio Humano/efectos de los fármacos , Sulfonamidas/farmacología , Carga Viral/efectos de los fármacosRESUMEN
GS-5806 is a small-molecule inhibitor of human respiratory syncytial virus fusion protein-mediated viral entry. During viral entry, the fusion protein undergoes major conformational changes, resulting in fusion of the viral envelope with the host cell membrane. This process is reproduced in vitro using a purified, truncated respiratory syncytial virus (RSV) fusion protein. GS-5806 blocked these conformational changes, suggesting a possible mechanism for antiviral activity.
Asunto(s)
Antivirales/farmacología , Pirazoles/farmacología , Virus Sincitial Respiratorio Humano/efectos de los fármacos , Virus Sincitial Respiratorio Humano/metabolismo , Sulfonamidas/farmacología , Proteínas Virales/química , Proteínas Virales/metabolismo , Indazoles , Conformación Proteica , Infecciones por Virus Sincitial RespiratorioRESUMEN
BACKGROUND: Preference for fatty foods is a risk factor for obesity. It is a complex behaviour that involves the brain reward system and is regulated by genetic and environmental factors, such as the opioid receptor mu-1 gene (OPRM1) and prenatal exposure to maternal cigarette smoking (PEMCS). We examined whether OPRM1 and PEMCS interact in influencing fat intake and whether exposure-associated epigenetic modifications of OPRM1 may mediate this gene-environment interaction. METHODS: We studied adolescents from a French Canadian genetic founder population, half of whom were exposed prenatally to maternal cigarette smoking. Fat intake was assessed with a 24-hour food recall in the form of a structured interview conducted by a trained nutritionist. The OPRM1 variant rs2281617 was genotyped for the whole sample with the Illumina Human610-Quad and HumanOmniExpress BeadChips. Methylation of blood DNA was assessed at 21 CpGs across OPRM1 in a subset of the sample using the Illumina HumanMethylation450 BeadChip. RESULTS: We included 956 adolescents in our study. In the whole sample, OPRM1 (T carrier in rs2281617) was associated with lower fat intake (-1.6%, p = 0.017), and PEMCS was associated with higher fat intake (+1.6%, p = 0.005). OPRM1 and PEMCS interacted with each other (p = 0.003); the "protective" (fat intake-lowering) allele of OPRM1 was associated with lower fat intake in nonexposed (-3.2%, p < 0.001) but not in exposed individuals (+0.8%, p = 0.42). Further, PEMCS was associated with lower DNA methylation across multiple CpGs across OPRM1 in exposed versus nonexposed individuals (p = 0.031). LIMITATIONS: A limitation of our study was its cross-sectional design. CONCLUSION: Our study suggests that PEMCS may interact with OPRM1 in increasing fat preference. Silencing of the protective OPRM1 allele in exposed adolescents might be related to epigenetic modification of this gene.
Asunto(s)
Grasas de la Dieta , Preferencias Alimentarias/fisiología , Interacción Gen-Ambiente , Efectos Tardíos de la Exposición Prenatal , Receptores Opioides mu/genética , Fumar/efectos adversos , Adolescente , Canadá , Islas de CpG , Estudios Transversales , Metilación de ADN , Femenino , Técnicas de Genotipaje , Humanos , Entrevistas como Asunto , Masculino , Polimorfismo de Nucleótido Simple , Embarazo , Población Blanca/genéticaRESUMEN
Novel 4'-substituted ß-d-2'-deoxy-2'-α-fluoro (2'd2'F) nucleoside inhibitors of respiratory syncytial virus (RSV) are reported. The introduction of 4'-substitution onto 2'd2'F nucleoside analogs resulted in compounds demonstrating potent cell based RSV inhibition, improved inhibition of the RSV polymerase by the nucleoside triphosphate metabolites, and enhanced selectivity over incorporation by mitochondrial RNA and DNA polymerases. Selectivity over the mitochondrial polymerases was found to be extremely sensitive to the specific 4'-substitution and not readily predictable. Combining the most potent and selective 4'-groups from N-nucleoside analogs onto a 2'd2'F C-nucleoside analog resulted in the identification of ß-D-2'-deoxy-2'-α-fluoro-4'-α-cyano-5-aza-7,9-dideaza adenosine as a promising nucleoside lead for RSV.
Asunto(s)
Adenosina/química , Antivirales/química , ADN Polimerasa Dirigida por ADN/química , Inhibidores de la Síntesis del Ácido Nucleico/química , ARN Polimerasa Dependiente del ARN/antagonistas & inhibidores , ARN/química , Virus Sincitiales Respiratorios/enzimología , Virus Sincitiales Respiratorios/fisiología , Adenosina/síntesis química , Adenosina/farmacología , Antivirales/síntesis química , Antivirales/farmacología , Compuestos Aza/química , ADN Polimerasa Dirigida por ADN/metabolismo , Evaluación Preclínica de Medicamentos , Inhibidores de la Síntesis del Ácido Nucleico/síntesis química , Inhibidores de la Síntesis del Ácido Nucleico/farmacología , ARN/metabolismo , ARN Mitocondrial , ARN Polimerasa Dependiente del ARN/metabolismo , Virus Sincitiales Respiratorios/efectos de los fármacos , Relación Estructura-Actividad , Replicación Viral/efectos de los fármacosRESUMEN
This longitudinal study aims to describe the development of body dissatisfaction (BD), measured with the Contour Drawing Rating Scale, between the ages of 14 and 18, and to identify factors associated with BD at age 18, among 413 adolescents. Between the ages of 14 and 18, the proportion of girls wanting to be thinner increased, although it remained unchanged among boys. A ratio of 1:2 girls and 1:5 boys reported having seriously tried to lose weight. Factors associated with BD in girls at age 18 were (1) wanting to be thinner, (2) body mass index (BMI), (3) weight control behaviours and (4) negative comments about weight. Factors associated with BD in boys at age 18 were (1) wanting to be thinner or bigger, (2) BMI, (3) having experienced sexual intercourse and (4) negative comments about weight. The high prevalence of BD and weight-related concerns suggest a need for early interventions.
RESUMEN
Obesity, a major risk factor for cardiometabolic disease, is associated with variations in a number of structural properties in the adult brain, as assessed with magnetic resonance imaging (MRI). In this study, we investigated the cross-sectional relationship between visceral fat (VF), total body fat (TBF) and three MRI parameters in the brains of typically developing adolescents: (i) T1-weighted (T1W) signal intensity; (ii) T1W signal contrast between white matter (WM) and gray matter (GM); and (iii) magnetization transfer ratio (MTR). In a community-based sample of 970 adolescents (12-18 years old, 466 males), VF was quantified using MRI, and total body fat was measured using a multifrequency bioimpedance. T1W images of the brain were used to determine signal intensity in lobar GM and WM, as well as WM:GM signal contrast. A magnetization transfer (MT) sequence of MT(ON) and MT(OFF) was used to obtain MTR in GM and WM. We found that both larger volumes of VF and more TBF were independently associated with higher signal intensity in WM and higher WM:GM signal contrast, as well as higher MTR in both GM and WM. These relationships were independent of a number of potential confounders, including age, sex, puberty stage, household income and height. Our results suggest that both visceral fat and fat deposited elsewhere in the body are associated independently with structural properties of the adolescent brain. We speculate that these relationships suggest the presence of adiposity-related variations in phospholipid composition of brain lipids.
Asunto(s)
Adiposidad/fisiología , Encéfalo/patología , Adolescente , Niño , Estudios Transversales , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Masculino , Obesidad/complicaciones , Obesidad/patologíaRESUMEN
The pituitary gland is a key structure in the hypothalamic-pituitary-gonadal (HPG) axis--it plays an important role in sexual maturation during puberty. Despite its small size, its volume can be quantified using magnetic resonance imaging (MRI). Here, we study a cohort of 962 typically developing adolescents from the Saguenay Youth Study and estimate pituitary volumes using a newly developed multi-atlas segmentation method known as the MAGeT Brain algorithm. We found that age and puberty stage (controlled for age) each predicts adjusted pituitary volumes (controlled for total brain volume) in both males and females. Controlling for the effects of age and puberty stage, total testosterone and estradiol levels also predict adjusted pituitary volumes in males and pre-menarche females, respectively. These findings demonstrate that the pituitary gland grows during adolescence, and its volume relates to circulating plasma-levels of sex steroids in both males and females.