Identification of di-substituted ureas that prevent growth of trypanosomes through inhibition of translation initiation

Some 1,3-diarylureas and 1-((1,4-trans)-4-aryloxycyclohexyl)-3-arylureas (cHAUs) activate heme-regulated kinase causing protein synthesis inhibition via phosphorylation of the eukaryotic translation initiation factor 2 (eIF2) in mammalian cancer cells. To evaluate if these agents have potential to inhibit trypanosome multiplication by also affecting the phosphorylation of eIF2 alpha subunit (eIF2 alpha), we tested 25 analogs of 1,3-diarylureas and cHAUs against Trypanosoma cruzi, the agent of Chagas disease. One of them (I-17) presented selectivity close to 10-fold against the insect replicative forms and also inhibited the multiplication of T. cruzi inside mammalian cells with an EC50 of 1-3 mu M and a selectivity of 17-fold. I-17 also prevented replication of African trypanosomes (Trypanosoma brucei bloodstream and procyclic forms) at similar doses. It caused changes in the T. cruzi morphology, arrested parasite cell cycle in G1 phase, and promoted phosphorylation of eIF2 alpha with a robust decrease in ribosome association with mRNA. The activity against T. brucei also implicates eIF2 alpha phosphorylation, as replacement of WT-eIF2 alpha with a non-phosphorylatable eIF2 alpha, or knocking down eIF2 protein kinase-3 by RNAi increased resistance to I-17. Therefore, we demonstrate that eIF2 alpha phosphorylation can be engaged to develop trypanosome-static agents in general, and particularly by interfering with activity of eIF2 kinases.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)CNPqFundacao de Amparo a Pesquisa do Estado do Rio de Janeiro (FAPERJ)NIHUniv Fed Sao Paulo, Escola Paulista Med, Dept Microbiol Imunol & Parasitol, BR-04039032 Sao Paulo, SP, BrazilUniv Fed Rio de Janeiro, Inst Biofis Carlos Chagas Filho, Lab Parasitol Mol, Rio De Janeiro, RJ, BrazilInst Butantan, Sao Paulo, SP, BrazilUniv Sao Paulo, Inst Ciencias Biomed, Dept Microbiol, Sao Paulo, SP, BrazilBrigham & Womens Hosp, Dept Med, Hematol Lab Translat Res, 75 Francis St, Boston, MA 02115 USAHarvard Med Sch, 75 Francis St, Boston, MA 02115 USAUniv Fed Sao Paulo, Escola Paulista Med, Dept Microbiol Imunol & Parasitol, BR-04039032 Sao Paulo, SP, BrazilFAPESP: 2015/20031-0FAPESP: 2014/01577-2CNPq: 445655/2014-3NIH: R01 CA152312Web of Scienc

Compreensão das características fisiopatológicas da hipertensão arterial sistêmica em relação a senescência: uma revisão de literatura

Introdução: A Hipertensão Arterial Sistêmica (HAS) é uma doença prevalente nos diversos âmbitos sociais e devido ao processo de envelhecimento natural do organismo, os idosos são mais propensos a adquirir essa doença. Objetivo: compreender as principais características relatadas na Hipertensão Arterial Sistêmica em associação ao processo fisiológico de envelhecimento, evidenciando, portanto, a importância do controle de fatores de risco evitáveis. Metodologia: Trata-se de uma revisão integrativa da literatura, por proporcionar uma síntese dos resultados obtidos através de pesquisas publicadas. Para direcionar a pesquisa, adotou-se como pergunta norteadora: “Quais as principais características associadas entre a Hipertensão Arterial Sistêmica e a senescência?" Para construção da pesquisa, a coleta e análise de dados foi realizada através do Portal da Biblioteca Virtual da Saúde e das bases de dados Medical Literature Analysis and Retrievel System Online via PubMed e Google Acadêmico através dos seguintes Descritores em Ciências da Saúde (DeCS): “Hipertensão Arterial Sistêmica”, “Senescência” e “Sintomas locais” combinados entre si pelo operador booleano AND com seus respectivos correspondentes no Mesh Terms. Discussão: Segundo dados das Pesquisa Nacional de Saúde (PNS) de 2013, aproximadamente 22% da população considerava-se portador de HA, sendo que indivíduos em uso de medicamentos anti-hipertensivos e com pressão arterial ≥ 140 por 90 mmHg superou a média de 33%. Por certo, pacientes mais idosos contam com uma maior rigidez arterial, atuando como a principal condição predisponente para elevação da pressão arterial. Conclusão: Com o aumento da expectativa de vida, há a prevalência e incidência maior de doenças progressivas, como a hipertensão arterial. Com isso, é essencial conduzir o devido conhecimento sobre os fatores de risco da HAS para a população, em especial os idosos, a fim de destacar a importância da prevenção e estimular o tratamento da pessoa idosa com Hipertensão Arterial Sistêmica

SARS-CoV-2 uses CD4 to infect T helper lymphocytes

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the agent of a major global outbreak of respiratory tract disease known as Coronavirus Disease 2019 (COVID-19). SARS-CoV-2 infects mainly lungs and may cause several immune-related complications, such as lymphocytopenia and cytokine storm, which are associated with the severity of the disease and predict mortality. The mechanism by which SARS-CoV-2 infection may result in immune system dysfunction is still not fully understood. Here, we show that SARS-CoV-2 infects human CD4+ T helper cells, but not CD8+ T cells, and is present in blood and bronchoalveolar lavage T helper cells of severe COVID-19 patients. We demonstrated that SARS-CoV-2 spike glycoprotein (S) directly binds to the CD4 molecule, which in turn mediates the entry of SARS-CoV-2 in T helper cells. This leads to impaired CD4 T cell function and may cause cell death. SARS-CoV-2-infected T helper cells express higher levels of IL-10, which is associated with viral persistence and disease severity. Thus, CD4-mediated SARS-CoV-2 infection of T helper cells may contribute to a poor immune response in COVID-19 patients.</p

SARS-CoV-2 uses CD4 to infect T helper lymphocytes

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the agent of a major global outbreak of respiratory tract disease known as Coronavirus Disease 2019 (COVID-19). SARS-CoV-2 infects mainly lungs and may cause several immune-related complications, such as lymphocytopenia and cytokine storm, which are associated with the severity of the disease and predict mortality. The mechanism by which SARS-CoV-2 infection may result in immune system dysfunction is still not fully understood. Here, we show that SARS-CoV-2 infects human CD4+ T helper cells, but not CD8+ T cells, and is present in blood and bronchoalveolar lavage T helper cells of severe COVID-19 patients. We demonstrated that SARS-CoV-2 spike glycoprotein (S) directly binds to the CD4 molecule, which in turn mediates the entry of SARS-CoV-2 in T helper cells. This leads to impaired CD4 T cell function and may cause cell death. SARS-CoV-2-infected T helper cells express higher levels of IL-10, which is associated with viral persistence and disease severity. Thus, CD4-mediated SARS-CoV-2 infection of T helper cells may contribute to a poor immune response in COVID-19 patients.</p

Activity of the Di-Substituted Urea-Derived Compound I-17 in Leishmania In Vitro Infections

Protein synthesis has been a very rich target for developing drugs to control prokaryotic and eukaryotic pathogens. Despite the development of new drug formulations, treating human cutaneous and visceral Leishmaniasis still needs significant improvements due to the considerable side effects and low adherence associated with the current treatment regimen. In this work, we show that the di-substituted urea-derived compounds I-17 and 3m are effective in inhibiting the promastigote growth of different Leishmania species and reducing the macrophage intracellular load of amastigotes of the Leishmania (L.) amazonensis and L. major species, in addition to exhibiting low macrophage cytotoxicity. We also show a potential immunomodulatory effect of I-17 and 3m in infected macrophages, which exhibited increased expression of inducible Nitric Oxide Synthase (NOS2) and production of Nitric Oxide (NO). Our data indicate that I-17, 3m, and their analogs may be helpful in developing new drugs for treating leishmaniasis

Systems approach reveals nuclear factor erythroid 2-related factor 2/protein kinase R crosstalk in human cutaneous Leishmaniasis

Leishmania parasites infect macrophages, causing a wide spectrum of human diseases, from cutaneous to visceral forms. In search of novel therapeutic targets, we performed comprehensive in vitro and ex vivo mapping of the signaling pathways upstream and downstream of antioxidant transcription factor [nuclear factor erythroid 2-related factor 2 (Nrf2)] in cutaneous leishmaniasis (CL), by combining functional assays in human and murine macrophages with a systems biology analysis of in situ (skin biopsies) CL patient samples. First, we show the PKR pathway controls the expression and activation of Nrf2 in Leishmania amazonensis infection in vitro. Nrf2 activation also required PI3K/Akt signaling and autophagy mechanisms. Nrf2- or PKR/Akt-deficient macrophages exhibited increased levels of ROS/RNS and reduced expression of Sod1 Nrf2-dependent gene and reduced parasite load. L. amazonensis counteracted the Nrf2 inhibitor Keap1 through the upregulation of p62 via PKR. This Nrf2/Keap1 observation was confirmed in situ in skin biopsies from Leishmania-infected patients. Next, we explored the ex vivo transcriptome in CL patients, as compared to healthy controls. We found the antioxidant response element/Nrf2 signaling pathway was significantly upregulated in CL, including downstream target p62. In silico enrichment analysis confirmed upstream signaling by interferon and PI3K/Akt, and validated our in vitro findings. Our integrated in vitro, ex vivo, and in silico approach establish Nrf2 as a central player in human cutaneous leishmaniasis and reveal Nrf2/PKR crosstalk and PI3K/Akt pathways as potential therapeutic targets.status: publishe

Les représentations sociales de l'évaluation des apprentissages chez des finissants d'un baccalauréat en éducation préscolaire et en enseignement primaire (BEPEP)

Dans un contexte où le domaine de l’éducation s’inspire des cadres de référence de différents paradigmes de l’apprentissage, cette recherche aborde les représentations sociales de l’évaluation des apprentissages chez des finissants d’un baccalauréat en éducation préscolaire et en enseignement primaire au Québec. Ce choix découle de la confusion existant dans les pratiques évaluatives des enseignants et dans le sentiment d’incompétence des futurs enseignants face à l’évaluation. La théorie des représentations sociales postule qu’elles se forment en fonction des expériences vécues tout au long d’une vie et qu’elles sont à la base de toute action. Les futurs enseignants ont vécu un type d’évaluation influencé par les principes du paradigme du néobéhaviorisme, mais ont reçu une formation axée sur les principes issus des paradigmes du constructivisme, du socioconstructivisme et du cognitivisme. À partir de ces présupposés, la question se pose à savoir quelles sont les représentations sociales de l’évaluation des apprentissages chez les finissants en éducation au préscolaire et en enseignement primaire ? Les représentations sociales sont formées de connaissances, d’opinions, de croyances et d’attitudes qui guident les conduites. Pour l’analyse, cette recherche s’appuie sur les théories du noyau central, des processus d’objectivation et d’ancrage et des principes organisateurs. L’évaluation des apprentissages y est également définie au regard des paradigmes principaux de l’apprentissage à savoir, le néobéhaviorisme, le constructivisme, le socioconstructivisme, le cognitivisme et l’humanisme. L’étude des représentations sociales demande d’analyser le discours des finissants, mais également les actions et les raisons sous-jacentes aux actions. L’approche par méthodes mixtes intègre, à la fois, une analyse de type quantitatif d’un questionnaire distribué à tous les finissants et une analyse de type qualitatif d’observations en classe et d’entretiens d’autoconfrontation menés auprès de quatre stagiaires. Les résultats du questionnaire mettent en évidence que les finissants définissent l’évaluation des apprentissages en évoquant des termes qui rejoignent les principes sous-jacents aux différents paradigmes de l’apprentissage avec une tendance pour les paradigmes du constructivisme et du néobéhaviorisme. Lorsque les finissants doivent se positionner à partir d’énoncés, ils sont toutefois favorables aux principes du paradigme du cognitivisme. Les observations indiquent une tendance chez les stagiaires à opter pour l’enseignement dirigé et collectif. Lors des entretiens d’autoconfrontation, les stagiaires valident leurs actions en exprimant des opinions rejoignant les différents paradigmes étudiés dans cette recherche. La discussion met en perspective trois interprétations de l’évaluation des apprentissages données par les stagiaires : l’évaluation en cours d’apprentissage axée sur le produit, l’évaluation en cours d’apprentissage axée sur le processus, l’évaluation de fin d’étape. La discussion met en évidence les différentes influences que subissent les stagiaires dans la construction de leurs représentations sociales, mais également leur façon d’interpréter les concepts intégrés durant leur formation initiale. L’auteure poursuit en questionnant les difficultés à intégrer la fonction de l’évaluation comme aide à l’apprentissage. Un retour sur les résultats significatifs de cette recherche, sur sa contribution scientifique ainsi que sur les perspectives de recherche au regard de l’évaluation comme aide à l’apprentissage clôt la thèse

Development of 1‑((1,4-trans)‑4-Aryloxycyclohexyl)-3-arylurea Activators of Heme-Regulated Inhibitor as Selective Activators of the Eukaryotic Initiation Factor 2 Alpha (eIF2α) Phosphorylation Arm of the Integrated Endoplasmic Reticulum Stress Response

Heme-regulated inhibitor (HRI), an eukaryotic translation initiation factor 2 alpha (eIF2α) kinase, plays critical roles in cell proliferation, differentiation, adaptation to stress, and hemoglobin disorders. HRI phosphorylates eIF2α, which couples cellular signals, including endoplasmic reticulum (ER) stress, to translation. We previously identified 1,3-diarylureas and 1-((1,4-trans)-4-aryloxycyclohexyl)-3-arylureas (cHAUs) as specific activators of HRI that trigger the eIF2α phosphorylation arm of ER stress response as molecular probes for studying HRI biology and its potential as a druggable target. To develop drug-like cHAUs needed for in vivo studies, we undertook bioassay-guided structure-activity relationship studies and tested them in the surrogate eIF2α phosphorylation and cell proliferation assays. We further evaluated some of these cHAUs in endogenous eIF2α phosphorylation and in the expression of the transcription factor C/EBP homologous protein (CHOP) and its mRNA, demonstrating significantly improved solubility and/or potencies. These cHAUs are excellent candidates for lead optimization for development of investigational new drugs that potently and specifically activate HRI

Development of 1‑((1,4-<i>trans</i>)‑4-Aryloxycyclohexyl)-3-arylurea Activators of Heme-Regulated Inhibitor as Selective Activators of the Eukaryotic Initiation Factor 2 Alpha (eIF2α) Phosphorylation Arm of the Integrated Endoplasmic Reticulum Stress Response

Heme-regulated inhibitor (HRI), an eukaryotic translation initiation factor 2 alpha (eIF2α) kinase, plays critical roles in cell proliferation, differentiation, adaptation to stress, and hemoglobin disorders. HRI phosphorylates eIF2α, which couples cellular signals, including endoplasmic reticulum (ER) stress, to translation. We previously identified 1,3-diarylureas and 1-((1,4-<i>trans</i>)-4-aryloxycyclohexyl)-3-arylureas (cHAUs) as specific activators of HRI that trigger the eIF2α phosphorylation arm of ER stress response as molecular probes for studying HRI biology and its potential as a druggable target. To develop drug-like cHAUs needed for in vivo studies, we undertook bioassay-guided structure–activity relationship studies and tested them in the surrogate eIF2α phosphorylation and cell proliferation assays. We further evaluated some of these cHAUs in endogenous eIF2α phosphorylation and in the expression of the transcription factor C/EBP homologous protein (CHOP) and its mRNA, demonstrating significantly improved solubility and/or potencies. These cHAUs are excellent candidates for lead optimization for development of investigational new drugs that potently and specifically activate HRI

Development of 1‑((1,4-<i>trans</i>)‑4-Aryloxycyclohexyl)-3-arylurea Activators of Heme-Regulated Inhibitor as Selective Activators of the Eukaryotic Initiation Factor 2 Alpha (eIF2α) Phosphorylation Arm of the Integrated Endoplasmic Reticulum Stress Response

Heme-regulated inhibitor (HRI), an eukaryotic translation initiation factor 2 alpha (eIF2α) kinase, plays critical roles in cell proliferation, differentiation, adaptation to stress, and hemoglobin disorders. HRI phosphorylates eIF2α, which couples cellular signals, including endoplasmic reticulum (ER) stress, to translation. We previously identified 1,3-diarylureas and 1-((1,4-<i>trans</i>)-4-aryloxycyclohexyl)-3-arylureas (cHAUs) as specific activators of HRI that trigger the eIF2α phosphorylation arm of ER stress response as molecular probes for studying HRI biology and its potential as a druggable target. To develop drug-like cHAUs needed for in vivo studies, we undertook bioassay-guided structure–activity relationship studies and tested them in the surrogate eIF2α phosphorylation and cell proliferation assays. We further evaluated some of these cHAUs in endogenous eIF2α phosphorylation and in the expression of the transcription factor C/EBP homologous protein (CHOP) and its mRNA, demonstrating significantly improved solubility and/or potencies. These cHAUs are excellent candidates for lead optimization for development of investigational new drugs that potently and specifically activate HRI