RESUMO
ABSTRACT: The ongoing coronavirus disease 2019 (COVID-19) pandemic caused by SARS-CoV-2 has significant implications in patients with concomitant cardiovascular disease (CVD) because they are the population at the greatest risk of death. The treatment of such patients and complications may represent a new challenge for the fields of cardiology and pharmacology. Thus, understanding the involvement of this viral infection in CVD might help to reduce the aggressiveness of SARS-CoV-2 in causing multiorgan infection and damage. SARS-CoV-2 disturbs the host epigenome and several epigenetic processes involved in the pathophysiology of COVID-19 that can directly affect the function and structure of the cardiovascular system (CVS). Hence, it would be relevant to identify epigenetic alterations that directly impact CVS physiology after SARS-CoV-2 infection. This could contribute to the view of this virus-induced CVS injury and direct forthcoming tackles for COVID-19 treatment to reduce mortality in patients with CVD. Targeting epigenetic marks could offer strong evidence for the development of novel antiviral therapies, especially in the context of COVID-19-related CVS damage. In this review, we address some of the main signaling pathways that are currently known as being involved in COVID-19 pathophysiology and the importance of this glint on epigenetics and some of its modifiers (epidrugs) to control the unregulated epitope activity in the context of SARS-CoV-2 infection, COVID-19, and underlying CVD.
Assuntos
Tratamento Farmacológico da COVID-19 , Doenças Cardiovasculares , Doenças Cardiovasculares/diagnóstico , Doenças Cardiovasculares/genética , Epigênese Genética , Humanos , SARS-CoV-2RESUMO
Toxoplasma gondii is an opportunistic protozoan pathogen with a wide geographic distribution. The chronic phase of toxoplasmosis is often asymptomatic in humans and is characterized by tissue cysts throughout the central nervous system and muscle cells. T. gondii and other pathogens with tropism for the central nervous system are considered risk factors in the etiology of several neuropsychiatric disorders, such as schizophrenia and bipolar disorder, besides neurological diseases. Currently, it is known that cerebral toxoplasmosis increases dopamine levels in the brain and it is related to behavioral changes in animals and humans. Here we evaluate whether chronic T. gondii infection, using the cystogenic ME-49 strain, could induce behavioral alterations associated with neuropsychiatric disorders and glutamatergic neurotransmission dysfunction. We observed that the startle amplitude is reduced in the infected animals as well as glutamate and D-serine levels in prefrontal cortical and hippocampal tissue homogenates. Moreover, we did not detect alterations in social preference and spontaneous alternation despite severe motor impairment. Thus, we conclude that behavioral and cognitive aspects are maintained even though severe neural damage is observed by chronic infection of C57Bl/6 mice with the ME-49 strain.
Assuntos
Ácido Glutâmico/metabolismo , Transtornos Mentais/etiologia , Transtornos Mentais/metabolismo , Reflexo de Sobressalto , Serina/metabolismo , Toxoplasmose Cerebral/complicações , Toxoplasmose Cerebral/parasitologia , Animais , Comportamento Animal , Peso Corporal , Encéfalo/metabolismo , Encéfalo/parasitologia , Encéfalo/patologia , Hipocampo/metabolismo , Transtornos Mentais/diagnóstico , Transtornos Mentais/psicologia , Camundongos , Neurotransmissores/metabolismo , Córtex Pré-Frontal/metabolismo , Comportamento Social , ToxoplasmaRESUMO
Parkinson's disease (PD) is an incurable progressive neurodegenerative disorder. Clinical presentation of PD stems largely from the loss of dopaminergic neurons in the nigrostriatal dopaminergic pathway, motivating experimental strategies of replacement based on cell therapy. Transplantation of dopaminergic neurons derived from embryonic stem cells significantly improves motor functions in rodent and non-human primate models of PD. However, protocols to generate dopaminergic neurons from embryonic stem cells generally meet with low efficacy and high risk of teratoma formation upon transplantation. To address these issues, we have pre-treated undifferentiated mouse embryonic stem cells (mESCs) with the DNA alkylating agent mitomycin C (MMC) before transplantation. MMC treatment of cultures prevented tumorigenesis in a 12 week follow-up after mESCs were injected in nude mice. In 6-OH-dopamine-lesioned mice, intrastriatal injection of MMC-treated mESCs markedly improved motor function without tumor formation for as long as 15 months. Furthermore, we show that halting mitotic activity of undifferentiated mESCs induces a four-fold increase in dopamine release following in vitro differentiation. Our findings indicate that treating mESCs with MMC prior to intrastriatal transplant is an effective to strategy that could be further investigated as a novel alternative for treatment of PD.
RESUMO
Müller cells constitute the main glial cell type in the retina where it interacts with virtually all cells displaying relevant functions to retinal physiology. Under appropriate stimuli, Müller cells may undergo dedifferentiation, being able to generate other neural cell types. Here, we show that purified mouse Müller cells in culture express a group of proteins related to the dopaminergic phenotype, including the nuclear receptor-related 1 protein, required for dopaminergic differentiation, as well the enzyme tyrosine hydroxylase. These dopaminergic components are active, since Müller cells are able to synthesize and release dopamine to the extracellular medium. Moreover, Müller-derived tyrosine hydroxylase can be regulated, increasing its activity because of phosphorylation of serine residues in response to agents that increase intracellular cAMP levels. These observations were extended to glial cells obtained from adult monkey retinas with essentially the same results. To address the potential use of dopaminergic Müller cells as a source of dopamine in cell therapy procedures, we used a mouse model of Parkinson's disease, in which mouse Müller cells with the dopaminergic phenotype were transplanted into the striatum of hemi-parkinsonian mice generated by unilateral injection of 6-hydroxydopamine. These cells fully decreased the apomorphine-induced rotational behavior and restored motor functions in these animals, as measured by the rotarod and the forelimb-use asymmetry (cylinder) tests. The data indicate local restoration of dopaminergic signaling in hemi-parkinsonian mice confirmed by measurement of striatal dopamine after Müller cell grafting.
Assuntos
Neurônios Dopaminérgicos/transplante , Células Ependimogliais/transplante , Transtornos Parkinsonianos/patologia , Transtornos Parkinsonianos/terapia , Animais , Cebus , Diferenciação Celular/fisiologia , Células Cultivadas , Corpo Estriado/citologia , Corpo Estriado/fisiologia , Modelos Animais de Doenças , Dopamina/metabolismo , Neurônios Dopaminérgicos/citologia , Neurônios Dopaminérgicos/metabolismo , Células Ependimogliais/citologia , Células Ependimogliais/metabolismo , Feminino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Atividade Motora/fisiologia , Membro 2 do Grupo A da Subfamília 4 de Receptores Nucleares/metabolismo , Transtornos Parkinsonianos/metabolismo , Fosforilação/efeitos dos fármacos , Fosforilação/fisiologia , Recuperação de Função Fisiológica/fisiologia , Tirosina 3-Mono-Oxigenase/metabolismoRESUMO
2,4-Dinitrophenol (DNP) is a neuroprotective compound previously shown to promote neuronal differentiation in a neuroblastoma cell line and neurite outgrowth in primary neurons. Here, we tested the hypothesis that DNP could induce neurogenesis in embryonic stem cells (ESCs). Murine ESCs, grown as embryoid bodies (EBs), were exposed to 20 µM DNP (or vehicle) for 4 days. Significant increases in the proportion of nestin- and ß-tubulin III-positive cells were detected after EB exposure to DNP, accompanied by enhanced glial fibrillary acidic protein (GFAP), phosphorylated extracellular signal-regulated kinase (p-ERK) and ATP-linked oxygen consumption, thought to mediate DNP-induced neural differentiation. DNP further protected ESCs from cell death, as indicated by reduced caspase-3 positive cells, and increased proliferation. Cell migration from EBs was significantly higher in DNP-treated EBs, and migrating cells were positive for nestin, ß-tubulin III and MAP2, similar to that observed with retinoic acid (RA)-treated EBs. Compared to RA, however, DNP exerted a marked neuritogenic effect on differentiating ESCs, increasing the average length and number of neurites per cell. Results establish that DNP induces neural differentiation of ESCs, accompanied by cell proliferation, migration and neuritogenesis, suggesting that DNP may be a novel tool to induce neurogenesis in embryonic stem cells.
Assuntos
2,4-Dinitrofenol/farmacologia , Corpos Embrioides/efeitos dos fármacos , Células-Tronco Embrionárias/efeitos dos fármacos , Neurogênese/efeitos dos fármacos , Neurônios/citologia , 2,4-Dinitrofenol/química , Animais , Diferenciação Celular , Linhagem Celular , Movimento Celular , Proliferação de Células , Corpos Embrioides/citologia , Corpos Embrioides/metabolismo , Células-Tronco Embrionárias/citologia , Proteína Glial Fibrilar Ácida , Camundongos , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Nestina/metabolismo , Neurônios/metabolismo , Consumo de Oxigênio , Tretinoína/farmacologia , Tubulina (Proteína)/metabolismoRESUMO
A agressividade, ou a violência, é um grave problema de saúde pública. Anualmente milhares de pessoas vão a óbito em consequência deste fenômeno. Os diversos modelos de estudo de agressividade são baseados na indução das agressões, por apenas dois indivíduos e em um período curto de tempo. Nosso objetivo é estruturar e aplicar um modelo que seja capaz de determinar o surgimento de episódios agressivos (não induzido - espontânea) e que possibilite o acompanhamento comportamental de um mesmo indivíduo desde sua infância até a idade adulta. Realizamos um esquema de agrupamento e reagrupamento e aplicamos metodologias comportamentais como etograma, teste do campo aberto, teste de suspensão da cauda (TSC) e caixa de preferência. Nossos resultados demonstram que 90% dos grupos apresentam padrões de comportamento agressivo (PCA) e em 10% dos indivíduos pudemos observar graves lesões e ferimentos decorrentes de agressões. Interessantemente, em 10% dos grupos não observamos PCA. Nesses grupos a atividade motora e exploratória foi superior aosgrupos agressivos. Além disso, o TSC demonstrou ser um eficiente método para definir o perfil de atividade de cada animal, sua possível posição hierárquica e sua influência no surgimento de PCA. Desta maneira, podemos concluir que o MEA demonstrou ser eficaz na reprodutibilidade da identificação e avaliação do surgimento de agressividade em grupos de camundongos em biotério. CEUA Nº LW 5/12.(AU)
The aggressiveness or violence is a serious public health issue. Annually, thousands of people will die as a result of this phenomenon. The various animal models of aggression study are based on the induction of injuries, by only two individuals and a short period of time. Our goal is to structure and implement a model that is able to determine the emergence of aggressive episodes (not induced - spontaneous) and enabling the monitoring behavior of a single individual from childhood to adulthood. We carry out a scheme of grouping and regrouping and applied behavioral methodologies as ethogram, open field test, tail suspension test and box preference. Our results described that 90% of groups showed pattern of aggressive behavior and 10% of individuals was observed serious injuries and injuries resulting from attacks or fight. Interestingly, 10% of the groups did not observe PCA. In respective group, the motor and exploratory activity was significantly superior to aggressive group. In addition, the TSC has proved an efficient method to set the activity profile of each animal, their hierarchical position and their possible influence on the genesis of PCA. Thus, we conclude that the MEA has proven effective in(AU)
Assuntos
Animais , Camundongos , Camundongos/classificação , Comportamento Animal , Violência , Saúde Pública/métodosRESUMO
A agressividade, ou a violência, é um grave problema de saúde pública. Anualmente milhares de pessoas vão a óbito em consequência deste fenômeno. Os diversos modelos de estudo de agressividade são baseados na indução das agressões, por apenas dois indivíduos e em um período curto de tempo. Nosso objetivo é estruturar e aplicar um modelo que seja capaz de determinar o surgimento de episódios agressivos (não induzido - espontânea) e que possibilite o acompanhamento comportamental de um mesmo indivíduo desde sua infância até a idade adulta. Realizamos um esquema de agrupamento e reagrupamento e aplicamos metodologias comportamentais como etograma, teste do campo aberto, teste de suspensão da cauda (TSC) e caixa de preferência. Nossos resultados demonstram que 90% dos grupos apresentam padrões de comportamento agressivo (PCA) e em 10% dos indivíduos pudemos observar graves lesões e ferimentos decorrentes de agressões. Interessantemente, em 10% dos grupos não observamos PCA. Nesses grupos a atividade motora e exploratória foi superior aosgrupos agressivos. Além disso, o TSC demonstrou ser um eficiente método para definir o perfil de atividade de cada animal, sua possível posição hierárquica e sua influência no surgimento de PCA. Desta maneira, podemos concluir que o MEA demonstrou ser eficaz na reprodutibilidade da identificação e avaliação do surgimento de agressividade em grupos de camundongos em biotério. CEUA Nº LW 5/12.
The aggressiveness or violence is a serious public health issue. Annually, thousands of people will die as a result of this phenomenon. The various animal models of aggression study are based on the induction of injuries, by only two individuals and a short period of time. Our goal is to structure and implement a model that is able to determine the emergence of aggressive episodes (not induced - spontaneous) and enabling the monitoring behavior of a single individual from childhood to adulthood. We carry out a scheme of grouping and regrouping and applied behavioral methodologies as ethogram, open field test, tail suspension test and box preference. Our results described that 90% of groups showed pattern of aggressive behavior and 10% of individuals was observed serious injuries and injuries resulting from attacks or fight. Interestingly, 10% of the groups did not observe PCA. In respective group, the motor and exploratory activity was significantly superior to aggressive group. In addition, the TSC has proved an efficient method to set the activity profile of each animal, their hierarchical position and their possible influence on the genesis of PCA. Thus, we conclude that the MEA has proven effective in
Assuntos
Animais , Camundongos , Camundongos/classificação , Comportamento Animal , Saúde Pública/métodos , ViolênciaRESUMO
Embryonic stem (ES) cells are pluripotent cells derived from the inner cell mass of blastocyst-stage early mammalian embryos. A crucial stage in the differentiation of ES cells is the formation of embryoid bodies (EBs) aggregates. EB formation is based on spontaneous aggregation when ES cells are cultured in non adherent plates. Three-dimensional EB recapitulates many aspects of early mammalian embryogenesis and differentiate into the three germ layers: ectoderm, mesoderm and endoderm. Immunofluorescence and in situ hybridization are widely used techniques for the detection of target proteins and mRNA present in cells of a tissue section. Here we present a simple technique to generate high quality cryosections of embryoid bodies. This approach relies on the spatial orientation of EB embedding in OCT followed by the cryosection technique. The resulting sections can be subjected to a wide variety of analytical procedures in order to characterize populations of cells containing certain proteins, RNA or DNA. In this sense, the preparation of EB cryosections (10 µm) are essential tools for histology staining analysis (e.g. Hematoxilin and Eosin, DAPI), immunofluorescence (e.g. Oct4, nestin) or in situ hybridization. This technique can also help to understand aspects of embryogenesis with regards to the maintenance of the tri-dimensional spherical structure of EBs.
Assuntos
Crioultramicrotomia/métodos , Corpos Embrioides/citologia , Células-Tronco Pluripotentes/citologia , Animais , Imunofluorescência , Hibridização In Situ , CamundongosRESUMO
Aims: To analyze the existence and distribution of some matrix proteins in tissue cysts of Toxoplasma gondii. Methods: Laminin and fibronectin in tissue cysts of Toxoplasma gondii were detected by confocal microscopy and transmission electron microscopy. Results: Ultrastructural immunocytochemistry showed both glycoproteins in the granular region of tissue cysts, cystic matrix, micronemes, rhoptries, dense granules and rarely at the membrane of bradyzoites of Toxoplasma gondii. Conclusions: The presence of both laminin and fibronectin in secretory organelles and in the apical region of bradyzoites suggests that exocytosis of these glycoproteins can contribute to their interaction with host cells, besides composing the cyst matrix of Toxoplasma gondii.
Assuntos
Imuno-Histoquímica , Fibronectinas , Glicoproteínas , Microscopia , Microscopia Eletrônica de Transmissão , Toxoplasmose/etiologiaRESUMO
Toxoplasmosis, caused by Toxoplasma gondii, is an important parasitic disease worldwide, which causes widespread human and animal diseases. The need for new therapeutic agents along with the biology of these parasites has fueled a keen interest in the understanding of the nutrients acquisition by these parasites. Studies on the characterization of the T. gondii cyst wall as well as the contribution of the host cell to this formation have been little explored. The aim of this paper was to investigate the electric surface charge of the T. gondii tissue cysts by ultrastructural cytochemistry, through polycationic markers, employing ruthenium red (RR) and cationized ferritin (CF). Glycosaminoglycans revealed by RR were localized on the cyst wall as a homogeneous granular layer electrondense, all over its surface. The incubation of living tissue cysts with CF for 20 min at 4 degrees C followed by the increase of temperature to 37 degrees C indicated that T. gondii cyst wall is negatively charged and that occurs an incorporation of anionic sites by the cyst wall, through vesicles and tubules, and their posterior location in the cyst matrix. So, as to identify which group of molecules produces negative charge in the cyst wall, we used enzymes for cleavage on different types of molecules, demonstrating that the negative charge in the cyst wall is mainly produced by phospholipids. Our results, described in this work show, for the first time, the negativities of the cyst wall, the incorporation and the traffic of intracellular surface molecules by T. gondii cyst wall. Our model of study can give an important contribution to the knowledge of the biology and the processes involved in nutrients acquisition by bradyzoites living inside the cysts and, and also be applied as a target for the direct action of drugs against the cyst.