RESUMO
Although ultrastructural characteristics of mature neuroglia in the central nervous system (CNS) are very well described in mammals, much less is known in reptiles, especially serpents. In this context, two specimens of Bothrops jararaca were euthanized for morphological analysis of CNS glial cells. Samples from telencephalon, mesencephalon and spinal cord were collected and processed for light and transmission electron microscopy investigation. Astrocytes, oligodendrocytes, microglial cells and ependymal cells, as well as myelin sheaths, presented similar ultrastructural features to those already observed in mammals and tended to maintain their general aspect all over the distinct CNS regions observed. Morphological similarities between reptilian and mammalian glia are probably linked to their evolutionary conservation throughout vertebrate phylogeny...
Muito embora as características ultraestruturais da neuróglia madura do sistema nervoso central (SNC) sejam bem descritas em mamíferos, muito pouco é conhecido em répteis, especialmente em serpentes. Neste contexto, dois espécimes de Bothrops jararaca foram eutanasiados para análise morfológica das células gliais presentes no SNC. Amostras de telencéfalo, mesencéfalo e medula espinhal foram coletadas e processadas para investigação por microscopia de luz e eletrônica de transmissão. Astrócitos, oligodendócitos, células microgliais e ependimárias, bem como bainhas de mielina, apresentaram características ultraestruturais similares àquelas já observadas em mamíferos e tenderam a manter seu aspecto geral pelas diferentes regiões observadas no SNC. Similaridades morfológicas entre as células gliais de mamíferos e de répteis estão provavelmente ligadas a sua conservação evolutiva ao longo da filogenia dos vertebrados...
Assuntos
Animais , Bothrops/anatomia & histologia , Neuroglia/ultraestrutura , Sistema Nervoso Central/ultraestrutura , Forma do Núcleo Celular , Serpentes/anatomia & histologiaRESUMO
Although ultrastructural characteristics of mature neuroglia in the central nervous system (CNS) are very well described in mammals, much less is known in reptiles, especially serpents. In this context, two specimens of Bothrops jararaca were euthanized for morphological analysis of CNS glial cells. Samples from telencephalon, mesencephalon and spinal cord were collected and processed for light and transmission electron microscopy investigation. Astrocytes, oligodendrocytes, microglial cells and ependymal cells, as well as myelin sheaths, presented similar ultrastructural features to those already observed in mammals and tended to maintain their general aspect all over the distinct CNS regions observed. Morphological similarities between reptilian and mammalian glia are probably linked to their evolutionary conservation throughout vertebrate phylogeny.(AU)
Muito embora as características ultraestruturais da neuróglia madura do sistema nervoso central (SNC) sejam bem descritas em mamíferos, muito pouco é conhecido em répteis, especialmente em serpentes. Neste contexto, dois espécimes de Bothrops jararaca foram eutanasiados para análise morfológica das células gliais presentes no SNC. Amostras de telencéfalo, mesencéfalo e medula espinhal foram coletadas e processadas para investigação por microscopia de luz e eletrônica de transmissão. Astrócitos, oligodendócitos, células microgliais e ependimárias, bem como bainhas de mielina, apresentaram características ultraestruturais similares àquelas já observadas em mamíferos e tenderam a manter seu aspecto geral pelas diferentes regiões observadas no SNC. Similaridades morfológicas entre as células gliais de mamíferos e de répteis estão provavelmente ligadas a sua conservação evolutiva ao longo da filogenia dos vertebrados.(AU)
Assuntos
Animais , Neuroglia/ultraestrutura , Bothrops/anatomia & histologia , Sistema Nervoso Central/ultraestrutura , Serpentes/anatomia & histologia , Forma do Núcleo CelularRESUMO
Currently, the necessity of controlling infestation by ticks, especially by Rhipicephalus sanguineus, has led researchers and public health managers around the world to search for new and more efficient control methods. This way, we can highlight neem (Azadirachta indica A. Juss) leaf, bark, and seed extracts, which have been very effective on tick control, and moreover causing less damage to the environment and to the host. This study showed the potential of neem as a control method for R. sanguineus through morphological and morphometric evaluation of the integument and synganglion of females, in semiengorged stage. To attain this, routine techniques of optical microscopy, scanning electron microscopy and morphometry of the cuticle and subcuticle of the integument were applied. Expressive morphological alterations were observed in both organs, presenting a dose-dependent effect. Integument epithelial cells and nerve cells of the synganglion showed signs of cell vacuolation, dilated intercellular boundaries, and cellular disorganization, alterations not previously reported in studies with neem. In addition, variations in subcuticle thickness were also observed. In general, the effects of neem are multiple, and affect the morphology and physiology of target animals in various ways. The results presented in this work are the first evidence of its effects in the coating and nervous system of ticks, thus allowing an indication of neem aqueous extracts as a potential control method of the brown dog tick and opening new perspectives on acaricide use.
Assuntos
Acaricidas/toxicidade , Sistema Nervoso Central/efeitos dos fármacos , Glicerídeos/toxicidade , Óleos de Plantas/toxicidade , Rhipicephalus sanguineus/efeitos dos fármacos , Terpenos/toxicidade , Animais , Sistema Nervoso Central/ultraestrutura , Feminino , Masculino , Microscopia Eletrônica de Varredura , Rhipicephalus sanguineus/fisiologia , Rhipicephalus sanguineus/ultraestruturaRESUMO
To date nothing is known about the subacute phase of neurodegeneration following injury in invertebrates. Among few clues available are the results published by our group reporting hemocytes and activated glial cells at chronic and acute phases of the lesion. In vertebrates, glial activation and recruitment of immunological cells are crucial events during neurodegeneration. Here, we aimed to study the subacute stage of neurodegeneration in the crab Ucides cordatus, investigating the cellular/molecular strategy employed 48 hours following ablation of the protocerebral tract (PCT). We also explored the expression of nitric oxide (NO) and histamine in the PCT during this phase of neurodegeneration. Three immune cellular features which seem to characterize the subacute phase of neurodegeneration were revealed by: 1) the recruitment of granulocytes and secondarily of hyalinocytes to the lesion site (inducible NO synthase- and histamine-positive cells); 2) the attraction of a larger number of cells than observed in the acute phase; 3) the presence of activated glial cells as shown by the round shaped nuclei and increased expression of glial fibrillary acidic protein. We suggest that molecules released from granulocytes in the acute phase attract the hyalinocytes thus moving the degeneration process to the subacute phase. The importance of our study resides in the characterization of cellular and biochemical strategies peculiar to the subacute stage of the neurodegeneration in invertebrates. Such events are worth studying in crustaceans because in invertebrates this issue may be addressed with less interference from complex strategies resulting from the acquired immune system.
Assuntos
Sistema Nervoso Central/imunologia , Sistema Nervoso Central/patologia , Crustáceos/imunologia , Imunidade Inata , Degeneração Neural/imunologia , Degeneração Neural/patologia , Animais , Sistema Nervoso Central/ultraestrutura , Crustáceos/ultraestrutura , Proteína Glial Fibrilar Ácida/metabolismo , Hemócitos/patologia , Hemócitos/ultraestrutura , Histamina/metabolismo , Masculino , Óxido Nítrico Sintase Tipo II/metabolismo , Lectinas de Plantas/metabolismoRESUMO
This study performed the ultrastructural description of the synganglion of Rhipicephalus sanguineus males and females, aiming to contribute to the understanding of the cellular organization of this organ. The results show that the central nervous system of these individuals consists of a mass of fused nerves, named synganglion, from where nerves emerge towards several parts of the body. It is surrounded by the neural lamella, a uniform and acellular layer, constituted by repeated layers of homogeneous and finely granular material. The perineurium is just below, composed of glial cells, which extensions invaginate throughout the nervous tissue. The synganglion is internally divided into an outer cortex, which contains the cellular bodies of the neural cells and an inner neuropile. The neural cells can be classified into two types according to cell size, cytoplasm-nucleus relation, and neurosecretory activity. Type I cells are oval or spherical and present a large nucleus occupying most part of the cytoplasm, which contains few organelles. Type 2 cells are polygonal, present a great cytoplasm volume, and their nuclei are located in the cell periphery. The cytoplasm of these cells contains a well-developed rough endoplasmic reticulum, Golgi regions, mitochondria, and several neurosecretory granules. The subperineurium and the tracheal ramifications are found between the cortex and the neuropile. The latter is formed mainly by neural fibers, tracheal elements, and glial cells. The results obtained show that R. sanguineus males' and females' nervous tissue present an ultrastructural organization similar to the one described in the literature for other tick species.
Assuntos
Sistema Nervoso Central/ultraestrutura , Rhipicephalus sanguineus/ultraestrutura , Animais , Feminino , MasculinoRESUMO
Los modelos experimentales en rata han sido de gran utilidad en las evaluaciones terapéuticas o de reemplazo de células en enfermedades neurodegenerativas. Se ha comprobado que las células de la médula ósea (CMO) de ratas pueden diferenciarse en células que no forman parte de sus linajes normales. Hay evidencias de estos procesos de trans-diferenciación, pero aún no se conocen los mecanismos moleculares que activan estos procesos. El propósito de nuestro trabajo fue estudiar el polimorfismo genético del ADN de los tipos celulares que conforman las CMO y las células del sistema nervioso central (SNC), estríatales y de la corteza de ratas mediante la técnica de RAPD. Las CMO, las células mononucleares (CMMO), las células estromales (CEMO) y las del SNC fueron obtenidas de ratas, y su ADN genómico fue purificado y amplificado mediante la técnica de RAPD, utilizando 15 cebadores al azar. Se construyó un dendograma de las bandas de amplificación generadas utilizando el método de UPGMA. Las células estudiadas según el análisis del RAPD quedaron en 2 grupos bien definidos, pudiéndose diferenciar las CEMO del resto de las células estudiadas. Los cebadores OPA-6, 7 y 12, mostraron el polimorfismo genético de los linajes de células estudiadas. Mediante la técnica de RAPD se demostró la variabilidad genética entre las CEMO y las CMMO, células estriadas y de corteza que mostraron una homogeneidad genética, proponiéndose marcadores específicos de RAPD para cada grupo de células. Este es el primer estudio del polimorfismo genético de las CMO y del SNC de ratas.
Experimental models have been of grate usefulness in the therapeutic or replacement cells in neurodegenerative diseases. It has been demonstrated that bone marrow cells (BMC), can be difefferentiated in cells that do not form part of their normal lineage. There is evidence of these trans-differentiation processes in these cells, but nevertheless, molecular mechanisms that activate these differentiation process still not known. The purpose of our work was to study the genetic polymorphism of those cellular types; that conform the rat bone marrow cells (BMC) as well as those of the central nervous system (CNS), striatum cells and cortex ones, trough RAPD technique. BM, mononuclear cells (BMMC), estromal cells (BMSC) and the CNS cells were obtained from rats and genomic ADN was purified and amplified through RAPD technique, using 15 random primers. A dendogram was constructed according to UPGMA method of the amplifying RAPD bands. Studied cells as- according to the RAPD analysis- were grouped into 2 well- defined groups, as CEMO coud be differentiated from the rest of studied cells. OPA-6, 7 and 12 primers showed the genetic polymorphism of the studied lineages cells. Also will be proposed specific RAPD genetic markers. Through RAPD technique permitted the genetic variability was demonstrated betwen BMEC and BMMC of striated cells and of cortex, which demonstratd a genetic homogeneity through RAPD technique so specific genetic markers of RAPD were thus propose for each group of cells. These constitute the first study on genetic polymorphism of BMC and CNS.
Assuntos
Medula Óssea/anormalidades , Medula Óssea/crescimento & desenvolvimento , Medula Óssea/imunologia , Medula Óssea/ultraestrutura , Polimorfismo Genético/fisiologia , Polimorfismo Genético/genética , Técnica de Amplificação ao Acaso de DNA Polimórfico , Sistema Nervoso Central/anormalidades , Sistema Nervoso Central/lesões , Sistema Nervoso Central/metabolismo , Sistema Nervoso Central/microbiologia , Sistema Nervoso Central/ultraestruturaRESUMO
A infecção por herpesvírus bovino (BoHV) é uma das principais causas de doença neurológica em bovinos na região Centro-Oeste do Brasil. O uso de técnicas moleculares de diagnóstico representa uma contribuição importante para o estudo dessa doença. Este trabalho descreve o uso de uma técnica específica de PCR multiplex para identificar BoHV-5 e BoHV-1 em 76 amostras de encéfalo de bovinos fixadas em formol e incluídas em parafina. Com base nas alterações histológicas, as amostras foram separadas em 2 grupos: o Grupo 1 era composto de 40 amostras de bovinos com meningoencefalite necrosante característica da infecção por BoHV; no Grupo 2 estavam 36 amostras de casos com encefalite não-supurativa inespecífica. Identificação de BoHV-5 foi constatada em 40 por cento das amostras do grupo 1 e em 33 por cento das amostras do grupo 2. Não houve amplificação de DNA de BoHV-1 em nenhuma amostra.(AU)
Bovine herpesvirus (BoHV) is an important cause of neurological disease in cattle in the Midwest Brazil. The application of molecular diagnostic techniques represents an important contribution for the study of BoHV. This paper describes the detection of BoHV-5 and BoHV-1 by a specific multiplex PCR assay in 76 paraffin-embedded samples from central nervous system (CNS) of cattle with neurological disorders. The samples were divided into 2 groups according to the histological features: Group 1 was composed of 40 cases of necrotizing meningoencephalitis (characteristic of BoHV infection), and Group 2 was composed of 36 cases of nonspecific nonsuppurative meningoencephalitis. Positive results for BoHV-5 accounted for 40 percent of the samples in the group 1 and 33 percent in the group 2. No detection of BoHV-1 was recorded.(AU)
Assuntos
Animais , Bovinos , Herpesvirus Bovino 1/isolamento & purificação , Sistema Nervoso Central/ultraestrutura , Meningoencefalite/diagnóstico , Meningoencefalite/mortalidade , Meningoencefalite/veterinária , Meningoencefalite/virologia , DNA Viral/análise , Doenças Transmissíveis , Doenças Neurodegenerativas , Encefalopatia Espongiforme BovinaRESUMO
A infecção por herpesvírus bovino (BoHV) é uma das principais causas de doença neurológica em bovinos na região Centro-Oeste do Brasil. O uso de técnicas moleculares de diagnóstico representa uma contribuição importante para o estudo dessa doença. Este trabalho descreve o uso de uma técnica específica de PCR multiplex para identificar BoHV-5 e BoHV-1 em 76 amostras de encéfalo de bovinos fixadas em formol e incluídas em parafina. Com base nas alterações histológicas, as amostras foram separadas em 2 grupos: o Grupo 1 era composto de 40 amostras de bovinos com meningoencefalite necrosante característica da infecção por BoHV; no Grupo 2 estavam 36 amostras de casos com encefalite não-supurativa inespecífica. Identificação de BoHV-5 foi constatada em 40 por cento das amostras do grupo 1 e em 33 por cento das amostras do grupo 2. Não houve amplificação de DNA de BoHV-1 em nenhuma amostra.
Bovine herpesvirus (BoHV) is an important cause of neurological disease in cattle in the Midwest Brazil. The application of molecular diagnostic techniques represents an important contribution for the study of BoHV. This paper describes the detection of BoHV-5 and BoHV-1 by a specific multiplex PCR assay in 76 paraffin-embedded samples from central nervous system (CNS) of cattle with neurological disorders. The samples were divided into 2 groups according to the histological features: Group 1 was composed of 40 cases of necrotizing meningoencephalitis (characteristic of BoHV infection), and Group 2 was composed of 36 cases of nonspecific nonsuppurative meningoencephalitis. Positive results for BoHV-5 accounted for 40 percent of the samples in the group 1 and 33 percent in the group 2. No detection of BoHV-1 was recorded.
Assuntos
Animais , Bovinos , DNA Viral/análise , Herpesvirus Bovino 1/isolamento & purificação , Meningoencefalite/diagnóstico , Meningoencefalite/mortalidade , Meningoencefalite/veterinária , Meningoencefalite/virologia , Sistema Nervoso Central/ultraestrutura , Doenças Transmissíveis , Encefalopatia Espongiforme Bovina , Doenças NeurodegenerativasRESUMO
A polyclonal antibody (C4), raised against the head domain of chicken myosin Va, reacted strongly towards a 65 kDa polypeptide (p65) on Western blots of extracts from squid optic lobes but did not recognize the heavy chain of squid myosin V. This peptide was not recognized by other myosin Va antibodies, nor by an antibody specific for squid myosin V. In an attempt to identify it, p65 was purified from optic lobes of Loligo plei by cationic exchange and reverse phase chromatography. Several peptide sequences were obtained by mass spectroscopy from p65 cut from sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) gels. BLAST analysis and partial matching with expressed sequence tags (ESTs) from a Loligo pealei data bank indicated that p65 contains consensus signatures for the heterogeneous nuclear ribonucleoprotein (hnRNP) A/B family of RNA-binding proteins. Centrifugation of post mitochondrial extracts from optic lobes on sucrose gradients after treatment with RNase gave biochemical evidence that p65 associates with cytoplasmic RNP complexes in an RNA-dependent manner. Immunohistochemistry and immunofluorescence studies using the C4 antibody showed partial co-labeling with an antibody against squid synaptotagmin in bands within the outer plexiform layer of the optic lobes and at the presynaptic zone of the stellate ganglion. Also, punctate labeling by the C4 antibody was observed within isolated optic lobe synaptosomes. The data indicate that p65 is a novel RNA-binding protein located to the presynaptic terminal within squid neurons and may have a role in synaptic localization of RNA and its translation or processing.
Assuntos
Sistema Nervoso Central/metabolismo , Ribonucleoproteínas Nucleares Heterogêneas/metabolismo , Loligo/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Terminações Pré-Sinápticas/metabolismo , Proteínas de Ligação a RNA/metabolismo , Animais , Sistema Nervoso Central/ultraestrutura , Gânglios dos Invertebrados/metabolismo , Gânglios dos Invertebrados/ultraestrutura , Ribonucleoproteínas Nucleares Heterogêneas/química , Ribonucleoproteínas Nucleares Heterogêneas/isolamento & purificação , Loligo/ultraestrutura , Peso Molecular , Proteínas do Tecido Nervoso/química , Proteínas do Tecido Nervoso/isolamento & purificação , Lobo Óptico de Animais não Mamíferos/metabolismo , Lobo Óptico de Animais não Mamíferos/ultraestrutura , Terminações Pré-Sinápticas/ultraestrutura , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/química , Proteínas de Ligação a RNA/isolamento & purificação , Ribonucleoproteínas Citoplasmáticas Pequenas/genética , Ribonucleoproteínas Citoplasmáticas Pequenas/metabolismo , Sinaptossomos/metabolismo , Sinaptossomos/ultraestruturaRESUMO
MicroRNAs são moléculas recém-descobertas de RNA não-codificadores que possuem de 21 a 24 nucleotídeos e que regulam a expressão após a transcrição dos genes alvo. Essa regulação pode ser realizada através da inibição da tradução ou da degradação do RNA mensageiro. Os miRNAs estão envolvidos em vários processo biológicos como, diferenciação celular e desenvolvimento embrionário, além de apresentarem expressão tecido e tempo-específica. Eles podem regular a expressão de pelo menos 1/3 de todos os genes humanos e estão envolvidos com a regulação do metabolismo e da apoptose. Os miRNAs são a chave como reguladores pós-transcricionais da neurogênese; estudos mostram que eles possuem a expressão associada com a transição entre proliferação e diferenciação e também tem expressão constitutiva em neurônios maduros, evidenciando o envolvimento dessas moléculas com o desenvolvimento do sistema nervoso central (SNC). Outros miRNAs estão sendo estudados e verifica-se que eles agem como reguladores de genes envolvidos em doenças como Alzheimer, Parkinson e, provavelmente, também devam possuir um papel na regulação das epilepsias. No primeiro trabalho, apresentado no segundo capítulo, investigamos o papel dos miRNAs no desenvolvimento do SNC através da quantificação de 104 miRNAs em cérebros em desenvolvimento de camundongos. No segundo trabalho, apresentado no terceiro capítulo, para analisarmos o papel dos miRNAs na epilepsia de lobo temporal, verificamos se havia presença de miRNAs com expressão diferenciada entre tecidos removidos de pacientes que se submeteram a cirurgia de hipocampectomia e tecidos normais provenientes de autópsias. Para ambos os experimentos, foram extraídos os RNAs dos tecidos e quantificados por PCR em tempo real com o kit MicroRNA Assay baseado em iniciadores com estrutura em stem loop. Nos camundongos, análises de bioinformática encontraram quatro cluster de acordo com a expressão dos miRNAs...
MicroRNAs are a new class of small RNA molecules (21-24 nucleotide-long) that negatively regulate gene expression either by translational repression or target mRNA degradation. It is believed that about 30% of all human genes are targeted by these molecules. MiRNAs are involved in many important biological processes including cell differentiation, embryonic development and central nervous system formation, besides they showed specific temporal-space expression. They can regulate 1/3 of human genes and are involved in metabolism and apoptosis. miRNAs are the key as neurogenesis postranscriptional regulation; studies previous indicates miRNA expression associate with proliferation and differentiation in development of central nervous system (CNS) and housekeeping expression in mature neurons. They are involved in several diseases as Alzkeimer's and Parkinson and may have a role in epilepsy regulation. In second chapter, we analyze the miRNA expression in mouse brain during four stages of CNS development; in third chapter, we analyze hippocampal tissue of four patients who underwent selective resection of the mesial temporal structures for the treatment of clinically refractory seizures. In addition we used control samples from autopsy (n=4) for comparison. In both experiments, total RNA was isolated from tissues and used in real-time PCR reactions with TaqMan¿ microRNA assays (Applied Biosystems) to quantify 104 (mouse brain) or 157 (human tissue) different miRNAs...