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In Mexico, there are no official public and reliably reported data on the total number and species of non-human animals used for scientific purposes. The aim of the current study was to calculate the total numbers of animals used for scientific and educational purposes in Mexico, from January 2015 to October 2021, based on data requested from the National Institute of Transparency, Access to Information and Protection of Personal Data (INAI, in Spanish). In this period, authorised laboratory animal facilities reported the use of 5,437,263 animals for scientific and educational purposes. However, these data should be viewed with caution, since there is no official register of all Mexican institutions that use animals for these purposes. The use of various species of different taxonomic groups was reported, including mammals, birds, reptiles, amphibians, fish and invertebrates. The main scientific purposes of this animal use were: technological development; innovation; laboratory testing; production of biologicals; quality control; diagnostic purposes; basic and applied research; and education. A robust system for the licensing and approval of animal use, as well as a means to ensure compliance with the relevant regulations, are both urgently required. In addition, in order to regulate animal use, monitor animal care and protect their welfare, the creation of a publicly accessible national database that records the number and species of the animals used is imperative.
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Peixes , Répteis , Animais , México , Anfíbios , Mamíferos , Animais de LaboratórioRESUMO
This article aims at raising awareness about the intersection of populism and bioethics. It argues that illiberal forms of populism may have negative consequences on the evolution of bioethics as a discipline and on its practical objectives. It identifies at least seven potential negative effects: (1) The rise of populist leaders fosters "epistemological populism," devaluing the expert and scientific perspectives on which bioethics is usually based, potentially steering policies away from evidence-based foundations. (2) The impact of "moral populism" is evident in legislative prioritization of the "morality of common people," often solicited through popular consultations on issues like abortion, drug legalization, or LGBT issues. (3) Populist distrust in autonomous governmental agencies and advisory bodies, including national bioethics commissions, can compromise expert advice, challenging both their authority and decisions. (4) Populists may erode transparency by undermining institutions responsible for it, hindering access to vital information for bioethical research. (5) "Medical populism" creates adversarial dynamics, prompting politicians to make simplistic healthcare policy decisions based on political rather than informed criteria, adversely affecting vulnerable populations. (6) Radical-right populist parties' "welfare chauvinism" may shape healthcare policies, impacting service access and resource allocation, disproportionately affecting vulnerable groups such as migrants, but indirectly affecting the rest of the population. (7) Nationalist sentiments associated with populism may obstruct international collaborations, posing challenges for global bioethics that seeks to address ethical concerns beyond national borders. In summary, these dynamics raise significant bioethical concerns encompassing evidence-based decision-making, transparency, healthcare equity, and global collaboration. How bioethicists may respond to these challenges is discussed.
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In Mexico, it is not known which institutions use animals for scientific purposes. This work reports, based on data requested from the National Institute of Transparency, Access to Information and Protection of Personal Data (INAI), the types of institutions that use animals for research and how many of these have an ethics committee. Research centres, colleges, hospitals, national institutes, technical colleges, and public universities are the types of institutions that report using animals for experimentation. Only 54% of institutions have ethics committees. Mexican institutions from 2015 to 2021 used a total of 2,112,786 animals. Mammals are the most widely used animal group. The scientific purposes for using animals depend on the type of institution that uses them. In Mexico, it is necessary to update the regulations in order to regulate the use, protection and the care of laboratory animals.
En México se desconoce cuáles son las instituciones que utilizan animales con fines científicos. Se reporta, a partir de datos solicitados al Instituto Nacional de Transparencia, Acceso a la Información y Protección de Datos Personales (INAI), los tipos de instituciones que usan animales y cuántas poseen un comité interno para el cuidado y uso de los animales de laboratorio. Los centros de investigación, colegios, hospitales, institutos nacionales, tecnológicos y universidades públicas son los tipos de instituciones que reportaron usar animales. El 54% de las instituciones poseen comités de ética. Un total de 2,112,786 animales fueron usados por instituciones del 2015 al 2021. Los mamíferos es el grupo animal más utilizado. El uso de los animales se encuentra en función del tipo de institución que los utiliza. En México, es necesario actualizar la normatividad, con el fin de regular el uso, la protección y el cuidado de los animales de laboratorio.
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Experimentação Animal , México , Animais , Experimentação Animal/ética , Animais de Laboratório , Universidades , HumanosRESUMO
This paper discusses the potential of an international agreement to ensure equitable vaccine distribution, addressing the failures witnessed during the COVID-19 pandemic. COVAX was unable to prevent vaccine monopolization and unequal distribution, which led to significant disparities in vaccination rates and avoidable deaths. Any future agreement on equitable vaccine distribution must address ethical and practical issues to ensure global health equity and access. The proposed agreement should recognize healthcare as a human right and consider vaccines beyond mere commodities, emphasizing the social responsibility of pharmaceutical companies to prioritize affordability, availability, and accessibility, particularly for low-income countries (LICs). Voluntary licensing agreements are suggested as a means to enhance access to essential medicines. The paper also outlines the necessity of international cooperation, with robust compliance mechanisms, to effectively enforce such an agreement and mitigate future health crises.
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Vacinas contra COVID-19 , COVID-19 , Indústria Farmacêutica , Acessibilidade aos Serviços de Saúde , Humanos , Indústria Farmacêutica/ética , COVID-19/prevenção & controle , COVID-19/epidemiologia , Cooperação Internacional , Equidade em Saúde , SARS-CoV-2 , Saúde Global , Países em DesenvolvimentoRESUMO
Several countries have implemented COVID-19 health passes or certificates to promote a safer return to in-person social activities. These passes have been proposed as a way to prove that someone has been vaccinated, has recovered from the disease, or has negative results on a diagnostic test. However, many people have questioned their ethical justification. This article presents some practical and ethical problems to consider in the event of wishing to implement these passes. Among the former, it is questioned how accurate diagnostic tests are as a means of ensuring that a person is not contagious, whether vaccination guarantees immunity, the fact that health passes can be forged, whether they encourage vaccination, and the problem that there is no universally recognized health pass. Among the ethical issues, it is discussed whether health passes promote discrimination and inequality and whether they violate rights to privacy and freedom. It is concluded that health passes have enough ethical justification to be implemented.
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COVID-19 , Humanos , Liberdade , PrivacidadeRESUMO
Members of the human APOBEC3 family of editing enzymes can inhibit various mobile genetic elements. APOBEC3A (A3A) can block the retrotransposon LINE-1 and the parvovirus adeno-associated virus type 2 (AAV-2) but does not inhibit retroviruses. In contrast, APOBEC3G (A3G) can block retroviruses but has only limited effects on AAV-2 or LINE-1. What dictates this differential target specificity remains largely undefined. Here, we modeled the structure of A3A based on its homology with the C-terminal domain of A3G and further compared the sequence of human A3A to those of 11 nonhuman primate orthologues. We then used these data to perform a mutational analysis of A3A, examining its ability to restrict LINE-1, AAV-2, and foreign plasmid DNA and to edit a single-stranded DNA substrate. The results revealed an essential functional role for the predicted single-stranded DNA-docking groove located around the A3A catalytic site. Within this region, amino acid differences between A3A and A3G are predicted to affect the shape of the polynucleotide-binding groove. Correspondingly, transferring some of these A3A residues to A3G endows the latter protein with the ability to block LINE-1 and AAV-2. These results suggest that the target specificity of APOBEC3 family members is partly defined by structural features influencing their interaction with polynucleotide substrates.
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Citidina Desaminase/química , Citidina Desaminase/metabolismo , DNA de Cadeia Simples/fisiologia , Dependovirus/fisiologia , Elementos Nucleotídeos Longos e Dispersos/fisiologia , Polinucleotídeos/metabolismo , Proteínas/química , Proteínas/metabolismo , Desaminase APOBEC-3G , Animais , Sequência de Bases , Citidina Desaminase/genética , DNA de Cadeia Simples/genética , DNA de Cadeia Simples/metabolismo , Dependovirus/genética , Dependovirus/metabolismo , Células HEK293 , Haplorrinos , Células HeLa , Humanos , Elementos Nucleotídeos Longos e Dispersos/genética , Modelos Moleculares , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Plasmídeos , Polinucleotídeos/química , Proteínas/genética , Retroelementos/genética , Alinhamento de Sequência , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Relação Estrutura-Atividade , Especificidade por SubstratoRESUMO
The potential for mitochondrial (mt) DNA mutation accumulation during antiretroviral therapy (ART), and preferential accumulation in patients with lipoatrophy compared with control participants, remains controversial. We sequenced the entire mitochondrial genome, both before ART and after ART exposure, in 29 human immunodeficiency virus (HIV)-infected Swiss HIV Cohort Study participants initiating a first-line thymidine analogue-containing ART regimen. No accumulation of mtDNA mutations or deletions was detected in 13 participants who developed lipoatrophy or in 16 control participants after significant and comparable ART exposure (median duration, 3.3 and 3.7 years, respectively). In HIV-infected persons, the development of lipoatrophy is unlikely to be associated with accumulation of mtDNA mutations detectable in peripheral blood.
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Antirretrovirais/efeitos adversos , DNA Mitocondrial/genética , Infecções por HIV/genética , Adulto , Estudos de Casos e Controles , Estudos de Coortes , DNA Mitocondrial/química , DNA Mitocondrial/efeitos dos fármacos , Infecções por HIV/tratamento farmacológico , Síndrome de Lipodistrofia Associada ao HIV/tratamento farmacológico , Síndrome de Lipodistrofia Associada ao HIV/genética , Haplótipos , Humanos , Masculino , Pessoa de Meia-Idade , Análise de Sequência de DNA , Suíça , Timidina/efeitos adversos , Timidina/análogos & derivadosRESUMO
Bioethics should pay more attention to globalization and some of its consequences than it has done so far. The COVID-19 pandemic would not have been possible without globalization, which has also increased some of its negative consequences. Globalization has intensified wildlife trade in the world. One of the main hypotheses about the origin of this pandemic is that it originated in illegal forms of wildlife trade in China. In the last 30 or 40 years, there have been zoonotic outbreaks at a much frequent pace than before, many of those have been related to wildlife trade. Legal and illegal wildlife trade has grown in the shadow of globalization. Second, globalization has had a huge impact on the redistribution of wealth in the world. Since 1990 income inequality has increased in most high- and in many middle- and low-income countries. A country's level of pre-COVID income inequality is the best predictor of the COVID death rate. These two issues are not unrelated. People living in poverty in LMIC tend to suffer more from infectious diseases and tend to be marginalized from the health sector. Additionally, poverty tends to reproduce the conditions under which zoonotic diseases can more easily spread.
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Retroviruses are both powerful evolutionary forces and dangerous threats to genome integrity. As such, they have imposed strong selective pressure on their hosts, notably triggering the emergence of restriction factors, such as TRIM5 alpha, that act as potent barriers to their cross-species transmission. TRIM5 alpha orthologues from different primates have distinct retroviral restriction patterns, largely dictated by the sequence of their C-terminal PRYSPRY domain, which binds the capsid protein of incoming virions. Here, by combining genetic and functional analyses of human and squirrel monkey TRIM5 alpha, we demonstrate that the coiled-coil domain of this protein, thus far essentially known for mediating oligomerization, also conditions the spectrum of antiretroviral activity. Furthermore, we identify three coiled-coil residues responsible for this effect, one of which has been under positive selection during primate evolution, notably in New World monkeys. These results indicate that the PRYSPRY and coiled-coil domains cooperate to determine the specificity of TRIM5 alpha-mediated capture of retroviral capsids, shedding new light on this complex event.
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Proteínas de Transporte/metabolismo , Proteínas/metabolismo , Animais , Fatores de Restrição Antivirais , Sequência de Bases , Sítios de Ligação , Proteínas do Capsídeo/metabolismo , Proteínas de Transporte/química , Interações Hospedeiro-Patógeno , Humanos , Macaca , Estrutura Terciária de Proteína , Proteínas/química , Retroviridae , Saimiri , Especificidade da Espécie , Proteínas com Motivo Tripartido , Ubiquitina-Proteína LigasesRESUMO
A World Health Organization (WHO) Ad Hoc Expert Group on the Next Steps for Covid-19 Vaccine Evaluation recently recommended placebo-controlled trials (PCT) of Covid-19 vaccines. PCTs are ethically acceptable when there is no proven effective and safe treatment for a certain condition. However, there are already some vaccines that have been approved and which have high levels of efficacy and safety. Any new vaccine under development must be tested against the most effective vaccines available. PCTs go against the participants' best interests, by putting them in a position of disadvantage while taking part in a trial, compared with people who are not in the trial and who could get vaccinated. Particularly in high-income countries, many people are getting vaccinated. This means that, following a recent trend in clinical trials, PCTs would have to be conducted in low- and middle-income countries, where there a number of advantages for drug companies, but where fatality rates of Covid-19 are, in many cases, much higher. For this and other reasons having to do with equal rights, participants in control groups should be protected with the most effective vaccines available.
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Pesquisa Biomédica/ética , Pesquisa Biomédica/normas , Vacinas contra COVID-19/normas , COVID-19/prevenção & controle , Ética Médica , Guias como Assunto , Placebos/normas , Humanos , Pandemias , SARS-CoV-2RESUMO
The current availability of five complete genomes of different primate species allows the analysis of genetic divergence over the last 40 million years of evolution. We hypothesized that the interspecies differences observed in susceptibility to HIV-1 would be influenced by the long-range selective pressures on host genes associated with HIV-1 pathogenesis. We established a list of human genes (n = 140) proposed to be involved in HIV-1 biology and pathogenesis and a control set of 100 random genes. We retrieved the orthologous genes from the genome of humans and of four nonhuman primates (Pan troglodytes, Pongo pygmaeus abeli, Macaca mulatta, and Callithrix jacchus) and analyzed the nucleotide substitution patterns of this data set using codon-based maximum likelihood procedures. In addition, we evaluated whether the candidate genes have been targets of recent positive selection in humans by analyzing HapMap Phase 2 single-nucleotide polymorphisms genotyped in a region centered on each candidate gene. A total of 1,064 sequences were used for the analyses. Similar median K(A)/K(S) values were estimated for the set of genes involved in HIV-1 pathogenesis and for control genes, 0.19 and 0.15, respectively. However, genes of the innate immunity had median values of 0.37 (P value = 0.0001, compared with control genes), and genes of intrinsic cellular defense had K(A)/K(S) values around or greater than 1.0 (P value = 0.0002). Detailed assessment allowed the identification of residues under positive selection in 13 proteins: AKT1, APOBEC3G, APOBEC3H, CD4, DEFB1, GML, IL4, IL8RA, L-SIGN/CLEC4M, PTPRC/CD45, Tetherin/BST2, TLR7, and TRIM5alpha. A number of those residues are relevant for HIV-1 biology. The set of 140 genes involved in HIV-1 pathogenesis did not show a significant enrichment in signals of recent positive selection in humans (intraspecies selection). However, we identified within or near these genes 24 polymorphisms showing strong signatures of recent positive selection. Interestingly, the DEFB1 gene presented signatures of both interspecies positive selection in primates and intraspecies recent positive selection in humans. The systematic assessment of long-acting selective pressures on primate genomes is a useful tool to extend our understanding of genetic variation influencing contemporary susceptibility to HIV-1.
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Evolução Molecular , Infecções por HIV/genética , HIV/patogenicidade , Primatas/genética , Animais , Códon/genética , Humanos , Estrutura Terciária de Proteína , Proteínas/química , Proteínas/genética , Proteínas/metabolismo , Seleção Genética , Alinhamento de Sequência , Frações Subcelulares/metabolismoRESUMO
Bioethical approaches to reproductive health have been of utmost importance for the last three decades in Mexico. As Mexican laws regarding abortion, assisted reproduction, and conscientious objection have been modified, a number of social actors with an interest in these areas have realized that they have to educate the different agents who take part in these procedures in a bioethical approach to reproductive health and rights. This strategy was first used in Mexico by the Catholic Church and many Catholic universities. Advocates, scientists, and feminist organizations, as well as some public universities, have also realized that a grounding in bioethics could help health providers to have an ethical frame that supports the provision of abortion services. Bioethics is also a good framework for supporting the legalization of abortion and for more liberal laws regarding assisted reproduction. So, for the last few years, one of the priorities of these two sides, Catholic and secular groups, has been to train healthcare personnel, lawyers, and members of ethics committees and members of Congress in the application of their respective bioethical perspectives.
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Aborto Induzido/ética , Bioética/educação , Religião , Saúde Reprodutiva/educação , Feminino , Humanos , México , GravidezRESUMO
The antiretroviral protein TRIM5alpha is known to have evolved different restriction capacities against various retroviruses, driven by positive Darwinian selection. However, how these different specificities have evolved in the primate lineages is not fully understood. Here we used ancestral protein resurrection to estimate the evolution of antiviral restriction specificities of TRIM5alpha on the primate lineage leading to humans. We used TRIM5alpha coding sequences from 24 primates for the reconstruction of ancestral TRIM5alpha sequences using maximum-likelihood and Bayesian approaches. Ancestral sequences were transduced into HeLa and CRFK cells. Stable cell lines were generated and used to test restriction of a panel of extant retroviruses (human immunodeficiency virus type 1 [HIV-1] and HIV-2, simian immunodeficiency virus [SIV] variants SIV(mac) and SIV(agm), and murine leukemia virus [MLV] variants N-MLV and B-MLV). The resurrected TRIM5alpha variant from the common ancestor of Old World primates (Old World monkeys and apes, approximately 25 million years before present) was effective against present day HIV-1. In contrast to the HIV-1 restriction pattern, we show that the restriction efficacy against other retroviruses, such as a murine oncoretrovirus (N-MLV), is higher for more recent resurrected hominoid variants. Ancestral TRIM5alpha variants have generally limited efficacy against HIV-2, SIV(agm), and SIV(mac). Our study sheds new light on the evolution of the intrinsic antiviral defense machinery and illustrates the utility of functional evolutionary reconstruction for characterizing recently emerged protein differences.
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Proteínas/fisiologia , Retroviridae/patogenicidade , Animais , Evolução Molecular , Células HeLa , Humanos , Mutagênese Sítio-Dirigida , Primatas , Proteínas/genética , Ubiquitina-Proteína LigasesRESUMO
Since 2007, when Mexico City decriminalized abortion during the first trimester, a debate has been taking place regarding abortion and the right to conscientious objection (CO). Many people argue that, since the provision of abortions (or "legal terminations of pregnancy" as they are called under Mexico City's law) is now a statutory duty of healthcare personnel there can be no place for "conscientious objection." Others claim that, even if such an objection were to be allowed, it should not be seen as a right, since talk about a right to CO may lead to a slippery slope where we may end up recognizing a right to disobey the law. In this paper, I argue that there is a right to CO and that this may be justified through the notions of autonomy and integrity, which a liberal democracy should respect. However, it cannot be an absolute right, and in the case of abortion, it conflicts with women's reproductive rights. Therefore, CO should be carefully regulated so that it does not obstruct the exercise of women's reproductive rights. Regulation should address questions about who is entitled to object, how such objection should take place, and what can legitimately be objected to.
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Introducción: las enfermedades crónicas van en aumento e implican múltiples consecuencias que, en un determinado momento, con el paso de los años, pueden llegar a un estado terminal de la enfermedad. El objetivo de este estudio fue analizar el discurso de enfermos crónicos sobre la muerte digna, la eutanasia y el suicidio médicamente asistido para visibilizar la necesidad de la regulación de la muerte digna. Materiales y métodos: se llevó a cabo una investigación cualitativa que se inserta dentro del paradigma del construccionismo social, mediante entrevistas a enfermos crónicos de la Ciudad de México, utilizando una guía semiestructurada. Se empleó el análisis del discurso para encontrar convergencias y diferencias en los discursos. Resultados: se entrevistaron siete personas vía telefónica de enero a marzo del 2022. Las principales enfermedades fueron: lupus, cáncer, artritis, diabetes y ovarios poliquísticos. Los discursos convergen hacia una muerte digna sin dolor, sufrimiento, tranquila y en casa. Coinciden sus discursos en legalizar la eutanasia y el suicidio médicamente asistido; sin embargo, hay divergencias en cuanto a solicitarlas. Conclusiones: la experiencia de la enfermedad crónica es un factor importante para aceptar en un futuro la muerte médicamente asistida, sin ser una carga para otros y evitar el dolor y sufrimiento al final de la vida. La religión influye en las decisiones, pero se puede observar una mayor apertura para aceptar la legalización de la muerte médicamente asistida.
Introduction: Chronic diseases are increasing in frequency and entail multiple consequences that can eventually lead to death. The study aim was to analyze the discourse of chronically-ill patients on death with dignity, euthanasia, and medically-assisted suicide to highlight the need for regulation of death with dignity. Materials and Methods: A qualitative study was conducted within the paradigm of social constructionism. A semi-structured guide was used to conduct interviews with chronically-ill patients in Mexico City. Discourse analysis was performed to identify convergences and differences in the discourses. Results: Seven interviews were conducted by telephone from January to March 2022. The main diseases of the interviewees were lupus, cancer, arthritis, diabetes, and polycystic ovaries. The discourses converged toward a preference for dignified death without pain or suffering that was calm, and occurred at home. The discourses included the topics of legalizing euthanasia and medically-assisted suicide, but the patients differed on whether or not these should be requested. Conclusions: The experience of chronic illness was an important factor in accepting medically-assisted death for the patients, who did not wish to be a burden on others and wanted to avoid pain and suffering at the end of their lives. Religion influenced the patients' decisions, but there was openness to accepting legalization of medically-assisted death.
Introdução: a incidência das doenças crônicas vem aumentando, e têm múltiplas consequências que num determinado momento, ao longo dos anos, podem chegar a um estado terminal da doença. O objetivo deste estudo foi analisar o discurso de pessoas com doenças crônicas sobre morte digna, eutanásia e suicídio medicamente assistido para tornar visível a necessidade de regulamentar a morte digna. Materiais e métodos: foi realizada uma pesquisa qualitativa que se insere no paradigma do construcionismo social. Entrevistas com pacientes crônicos na Cidade do México foram realizadas usando um guia semiestruturado. A análise do discurso foi utilizada para encontrar convergências e divergências nos discursos. Resultados: foram realizadas sete entrevistas por telefone no período de janeiro a março de 2022. As principais doenças foram lúpus, câncer, artrite, diabetes e ovários policísticos. Os discursos convergem para uma morte digna sem dor, sofrimento, tranquila e em casa. Seus discursos coincidem na legalização da eutanásia e do suicídio medicamente assistido; entretanto, há divergências quanto à sua solicitação. Conclusões: a experiência da doença crônica é um fator importante para aceitar a morte medicamente assistida no futuro, sem ser um fardo para os outros e evitando a dor e o sofrimento no final da vida. A religião influencia nas decisões, mas observase uma maior abertura para aceitar a legalização da morte medicamente assistida.
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HumanosRESUMO
The metabotropic glutamate receptor 4 (mGluR4) is an emerging target for the treatment of Parkinson's disease (PD). However, since the discovery of its therapeutic potential, no ligand has been successfully developed enough to be tested in the clinic. In the present paper, we report for the first time the medicinal chemistry efforts conducted around the pharmacological tool (-)-PHCCC. This work led to the identification of compound 40, a potent and selective mGluR4 positive allosteric modulator (PAM) with good water solubility and demonstrating consistent activity across validated preclinical rodent models of PD motor symptoms after intraperitoneal administration: haloperidol-induced catalepsy in mouse and the rat 6-hydroxydopamine (6-OHDA) lesion model. Moreover, we also describe the identification of compound 60 a close analogue of compound 40 with improved pharmacokinetic profile after oral administration. On the basis of its favorable and unique preclinical profile, compound 60 (PXT002331, now foliglurax) was nominated as a candidate for clinical development.
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Antiparkinsonianos/farmacologia , Encéfalo/efeitos dos fármacos , Descoberta de Drogas , Receptores de Glutamato Metabotrópico/efeitos dos fármacos , Regulação Alostérica , Animais , Antiparkinsonianos/farmacocinética , Cromatografia Líquida , Células HEK293 , Humanos , Espectrometria de Massas , Camundongos , Espectroscopia de Prótons por Ressonância Magnética , Ratos , Relação Estrutura-AtividadeRESUMO
BACKGROUND: Evolutionary analysis may serve as a useful approach to identify and characterize host defense and viral proteins involved in genetic conflicts. We analyzed patterns of coding sequence evolution of genes with known (TRIM5alpha and APOBEC3G) or suspected (TRIM19/PML) roles in virus restriction, or in viral pathogenesis (PPIA, encoding Cyclophilin A), in the same set of human and non-human primate species. RESULTS AND CONCLUSION: This analysis revealed previously unidentified clusters of positively selected sites in APOBEC3G and TRIM5alpha that may delineate new virus-interaction domains. In contrast, our evolutionary analyses suggest that PPIA is not under diversifying selection in primates, consistent with the interaction of Cyclophilin A being limited to the HIV-1M/SIVcpz lineage. The strong sequence conservation of the TRIM19/PML sequences among primates suggests that this gene does not play a role in antiretroviral defense.
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Evolução Molecular , Proteínas/genética , Retroviridae/patogenicidade , Animais , Genômica , Interações Hospedeiro-Parasita/genética , Primatas/genética , Primatas/virologia , Retroviridae/genética , Seleção Genética , Vírus da Imunodeficiência Símia/genética , Vírus da Imunodeficiência Símia/patogenicidadeRESUMO
BACKGROUND: The retroviral restriction factor tripartite motif protein (TRIM)5alpha, is characterized by marked amino acid diversity among primates, including specific clusters of residues under positive selection. The identification of multiple non-synonymous changes in humans suggests that TRIM5alpha variants might be relevant to retroviral pathogenesis. Previous studies have shown that such variants are unlikely to modify susceptibility to HIV-1 infection, or the course of early infection. However, the longterm effect of carrying Trim5alpha variants on disease progression in individuals infected with HIV-1 has not previously been investigated. METHODS: In a cohort of 979 untreated individuals infected with HIV-1 with median follow up 3.2 years and 9,828 CD4 T cell measurements, we analysed common amino acid variations: H43Y, V112F, R136Q, G249D, and H419Y. The rate of CD4 T cell decline before treatment was used as the phenotype. In addition, we extended previous work on the in vitro susceptibility of purified donor CD4 T cells (n = 125) to HIV-1 infection, and on the susceptibility of HeLa cells that were stably transduced with the different TRIM5 variants. Haplotypes were analysed according to the most parsimonious evolutionary structure, where two main human TRIM5alpha groups can be defined according to the residue at amino acid 136. Humans present both Q136 and R136 at similar frequency, and additional TRIM5alpha amino acid variants are almost exclusively derived from R136-carrying haplotypes. RESULTS: We observed modest differences in disease progression for evolutionary branches carrying R136-derived haplotypes, and with the non-synonymous polymorphisms G249D and H419Y. In vitro analysis of susceptibility of donor CD4 T cells, and of the various transduced HeLa cell lines supported the absence of significant differential restriction of HIV-1 infection by the various huTRIM5alpha alleles. CONCLUSION: Common human variants of TRIM5alpha have no effect or modest effect on HIV-1 disease progression. These variants occur at sites conserved throughout evolution, and are remote from clusters of positive selection in the primate lineage. The evolutionary value of the substitutions remains unclear.
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Proteínas de Transporte/genética , Infecções por HIV/genética , HIV-1 , Adulto , Fatores de Restrição Antivirais , Contagem de Linfócito CD4 , Linfócitos T CD4-Positivos/imunologia , Estudos de Coortes , Progressão da Doença , Feminino , Predisposição Genética para Doença , Infecções por HIV/imunologia , Infecções por HIV/patologia , Células HeLa , Humanos , Masculino , Polimorfismo de Nucleotídeo Único , Isoformas de Proteínas , Proteínas com Motivo Tripartido , Ubiquitina-Proteína LigasesRESUMO
Numerous in vitro studies attribute to human TRIM5α some modest anti-HIV-1 activity and human population studies suggest some differential effect of TRIM5α polymorphisms on disease progression. If the activity of TRIM5α were relevant in vivo, it could result in positive selection on the viral capsid. To address this issue, we identified 10 positively selected sites in HIV-1 capsid from multiple viral strains and generated 17 clade B viruses carrying a minor (i.e. low frequency) residue or an alanine at those positions. All recombinant viruses were susceptible to the modest effect of common human TRIM5α and allelic variants R136Q, and H419Y; H43Y and G249D TRIM5α were generally inactive. Increased sensitivity to TRIM5α was observed for some capsid variants, suggesting that minor residues are selected against in human populations. On the other hand, the modest potency of human TRIM5α does not translate in escape mutations in the viral capsid.