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The pig has similar features to the human in aspects such as physiology, immunology, and organ size. Because of these similarities, genetically modified pigs have been generated for xenotransplantation. Also, when using the pig as a model for human diseases (e.g. cystic fibrosis transmembrane conductance regulator), the pig exhibited similar symptoms to those that human patients present. The main goal of this work was to examine the efficacy of direct injection of the CRISPR/Cas9 system (clustered regularly interspaced short palindromic repeats/ CRISPR associated protein 9) in pigs and to overcome shortcomings that resulted after direct injection into the cytoplasm of developing zygotes. By using direct injection of CRISPR/Cas9 into developing zygotes, we successfully generated fetuses and piglets containing 9 different mutations. The total number of aborted fetuses was 20 and of live piglets was 55. Moreover, one issue that was encountered during the production of mutated pigs was that insertion or deletion (indel) mutations did not always introduce a premature stop codon because it did not interfere with the codon read. As a result of these triplet indel(s) mutations, a hypomorphic phenotype was presented; consequently, the mutated gene was partially functional. To prevent this hypomorphic phenotype, we introduced two sgRNAs to generate an intended deletion that would remove a DNA fragment on the genome by causing two double-strand breaks (DSB) during non-homologous end joining (NHEJ). The injection of two sgRNAs successfully generated the intended deletion on the targeted genes in embryos and live piglets. Results after using intended deletions, in IL2RG mutation pigs, did not show hypomorphic phenotypes even when a premature stop codon was not present. After using the intended deletion approach, function of the targeted genes was completely disrupted regardless of the presence or absence of a premature stop codon. Our next aim was to introduce (i.e. knock-in) a portion of exogenous (donor) DNA sequence into a specific locus by utilizing the homology direct repair (HDR) pathway. Because of the cytotoxicity of the linear form of the donor DNA, the concentration of the injected donor DNA was adjusted. After concentration optimization, four different donor DNA fragments targeting four different genes were injected into zygotes. Efficiency of knock-in was an average of 35%. Another donor DNA was used in this study which is IL2RG-IA donor DNA carried 3kb of exogenous cassette. It showed 15.6% of knock-in efficiency. IL2RG-IA Donor DNA injected embryos were transferred into surrogates, and a total of 7 pigs were born from one surrogate, but none of the 7 were positive for the knock-in. Future experiments need to be developed to optimize this approach. Overall, the direct injection of CRISPR/Cas9 is advantageous in cost, time, and efficiency for large animal production and for biomedical research. However, there are still unsolved challenges (off-targeting effects, low efficiency of knock-in, and monoallelic target mutation) that need to be elucidated for future application in humans and other species. / Doctor of Philosophy / The clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR associated protein 9 (Cas9) system is commonly used to make genetically modified pigs. The CRISPR/Cas9 system can break the DNA on a desired gene region. During the DNA repair process, random DNA base pairs can be inserted or deleted on the broken regions, thus generating a mutation on the desired gene. Scientists have adopted new methods to disrupt genes in many species. One of these new methods is the direct injection of CRISPR/Cas9 into a fertilized oocyte. In our first project, we used direct injection of the CRISPR/Cas9 system into the fertilized one-cell embryo. A total of 55 live pigs and aborted 20 fetuses with specifically disrupted genes were produced for biomedical research model. During these studies, one critical drawback of the direct injection method was encountered. Partial function of the gene was possible. To prevent this problem, two DNA broken regions were generated by the CRISPR/Cas9 system to remove the middle part the DNA by two DNA breaking. This method successfully removed the middle portion of the DNA targeted region in the pig embryos. Embryos injected with the CRISPR/Cas9 system to cut the two specific DNA regions were transplanted into surrogate pigs, and a total of 15 piglets were produced. All 15 pigs confirmed that a specific part of the gene had been removed by two DNA breakage. Also, no function of the desired gene was found in the 15 pigs. The objective of the last experiment was to introduce a specific exogenous DNA sequences into specific region of DNA using the CRISPR/Cas9 system. For this study, four different exogenous DNA fragments were synthesized for four different genes. When injected, one exogenous DNA along with the CRISPR/Cas9 system, the average integration efficiency of the four exogenous DNA fragments was 35% in the embryo. Another exogenous DNA, which was longer than other four DNA fragments showed 15.6% integration efficiency. The embryos injected with the long exogenous DNA fragment, along with the CRISPR/Cas9 system, were transferred into surrogate pigs. The result was that a total of 7 piglets were born, but the exogenous DNA sequence was not found in none of the seven piglets. In conclusion, the CRISPR/Cas9 system showed effective removal of the entire gene function of specific genes in the pig. However, for future application in the human and other species, some problems (un-wanted region mutation and low efficiency of exogenous DNA integration) continue to emerge and need to be addressed in future experiments.

Duchenne muscular dystrophy (DMD) is a severe and fatal muscle wasting disease characterized by a high mutation rate in the gene that encodes the membrane-associated protein dystrophin that results in absence of expressed protein. Although the primary genetic defect for DMD is known, the mechanisms that initiate the onset of DMD are not currently understood. This study tested the hypothesis that pathophysiological processes involved in DMD could be identified by the global expression of mRNA in maturing dystrophin- and utrophin-deficient mouse (mdx:utrn-/-) muscles. Two potential dystrophic onset mechanisms targeted for analysis were (1) disrupted expression of calcium handling proteins; and, (2) increased expression of immune response markers. An mRNA expression profile was developed following isolation of total RNA from control and mdx:utrn-/- triceps surae (TS) muscles at ages 9-10 and 20-21 days using Affymetrix® Mu74Av2 GeneChips®. Compared to control, the mRNA expression profile in mdx:utrn-/- muscles revealed there was a 3-fold increase in the number of gene transcripts differentially expressed more than 2-fold (53 transcripts at ages 9-10 days; 153 at ages 20-21 days). However, there were no changes in the mRNA transcripts for calcium handling proteins. In distinct contrast, there was up-regulation of transcripts that corresponded to an immune response (40 transcripts), extracellular matrix activity (14), and proteolysis (8). Up-regulation of several transcripts corresponded to cytokines and their receptors (11), chemokines and their receptors (5), and lymphoid and myeloid markers (16) suggesting that dystrophic muscle is susceptible to invasion by macrophages, leukocytes, B- and T-cells. These results are consistent with several reports (Spencer et al., 1997; Chen et al., 2000; Porter et al., 2002; Porter et al., 2003a; Porter et al., 2003b; Porter et al., 2004) that indicate the immune system may play an important role in the early pathophysiology of DMD. Understanding the functional aspects of an immune response in DMD onset should lead to more effective therapeutics. / Master of Science

Le système nerveux somatosensoriel permet l'interaction entre l'organisme et son environnement. Ce système collecte, via des récepteurs périphériques, les stimuli extérieurs et les transmet au système nerveux central par les neurones sensoriels primaires, dont les corps cellulaires sont situés dans les ganglions rachidiens dorsaux. Ces neurones primaires sont spécifiques des différentes sensations et ont, pour y répondre, des récepteurs, des modalités sensorielles, des caractéristiques moléculaires différentes. Ils sont généralement séparés en 3 grandes familles: les propriocepteurs, les mécanocepteurs et les nocicepteurs, chacune de ces familles se séparant à son tour en une multitude de sous familles. Ces neurones dérivent de la crête neurale, une structure spécifique des vertébrés. Au cours de leur migration vers les ganglions rachidiens dorsaux, les cellules vont être soumises à un grand nombre de facteurs et de voies de signalisation, qui vont entrainer leur survie, leur mort ou leur différenciation. Le facteur de transcription Meis2 a été isolé par l'équipe comme un candidat pouvant intervenir dans cette différentiation des cellules en neurones différenciés. Chez les souris, son expression est spécifique de sous populations mécanoceptives et proprioceptives, et s'étend des stades précoces de développement jusqu'à l'âge adulte. La lignée conditionnelle de souris Knock Out pour Meis2, croisée avec la lignée Wnt1cre, permet l'abolition de Meis2 dans toutes les cellules de la crête neurale et ses dérivés. Le mutant issu de ce croisement meurt à la naissance, avec de nombreux problèmes phénotypiques. Cette lignée cKOMeis2 a alors été croisée avec la lignée Islet1cre, ce qui permet d'invalider le gène Meis2 dans les neurones post-mitotiques des ganglions rachidiens dorsaux. Cette souris m'a servi de modèle afin de déterminer les conséquences éventuelles de la perte de Meis2 dans les neurones sensoriels du ganglion rachidien dorsal par analyse comportementale. / The somatosensory nervous system allows the interaction between the organism and the environment. This system receives from peripheral receptors some exterior stimuli which are transmitted to the central nervous system by sensory primary neurons. Their cell bodies are located in the dorsal root ganglions (DRG). These primary neurons are specific to various sensations and are characterized by specific receptors, sensory modalities and molecular characteristics involved in their response. They are usually defined as belonging to one of three main families: proprioceptors, mecanoceptors and nociceptors, and each family is composed of a large number of subgroups. These neurons are derived from the neural crest cells to form the DRG. The cells are exposed to a number of key pathways and factors, which permit their survival, death or differentiation. The transcription factor Meis2 was isolated by our team as a good candidate to act in the differentiation or specification of these cells into sensory neurons. The expression pattern of Meis2 is shown to be specific to the mecanoceptor and proprioceptor subgroups and starts, in mice, from the early stages of development up to the adult age. To investigate the role of Meis2 the conditional strain mice Meis2 Knock Out (cKOMeis2) were crossed with the strain Wnt1cre which invalidates the gene Meis2 in all the neural crest and derived cells. The new born mice die at birth with most showing phenotypic dysfunctions. Finally, this cKOMeis2 strain was crossed with Islet1cre which specifically disrupts the Meis2 gene in post-mitotic DRG neurons. This thesis characterises the Islet1cre/+cKOMeis2LoxP/LoxP strain in order to determine the behavioural consequences of the loss of the Meis2 protein in DRG sensory neurons.

A molécula adaptadora myeloid differentiation primary response gene 88 (MyD88) está envolvida na ativação de receptores Toll-like (TLRs), os quais são responsáveis pelo reconhecimento precoce pelas células do hospedeiro de patógenos invasores e pelo desencadeamento da resposta imunológica. O objetivo do presente estudo foi caracterizar o desenvolvimento e a progressão de lesões periapicais induzidas experimentalmente em dentes de camundongos knockout (KO) para a molécula MyD88 (MyD88 KO), comparados a animais wild-type (WT). Lesões periapicais foram induzidas nos primeiros molares inferiores de 30 camundongos WT e de 30 camundongos MyD88 KO. Decorridos 7, 21 e 42 dias, os animais foram submetidos à eutanásia em câmara de CO2 e as mandíbulas foram removidas e submetidas ao processamento histotécnico. A seguir, cortes representativos foram corados com hematoxilina e eosina (HE), para descrição das características do canal radicular e das regiões apical e periapical e para contagem do número de células inflamatórias (neutrófilos), em microscopia de luz, e para mensuração da área das lesões periapicais, em microscopia de fluorescência. Espécimes sequenciais foram analisados por meio de: histoenzimologia para a atividade da TRAP, para contagem de osteoclastos; coloração de Brown & Brenn, para localização de bactérias; e imunohistoquímica, para identificação de marcadores da osteoclastogênese (RANK, RANKL e OPG). Os dados foram submetidos à análise estatística por meio dos testes não-paramétricos de Mann-Whitney, Kruskal-Wallis e pós-teste de Dunn, utilizando o programa SPSS (Statistical Package for the Social Sciences) versão 17.O, com nível de significância de 5%. As demais análises foram expressas de maneira qualitativa. Com relação à extensão das lesões periapicais, o grupo MyD88 KO apresentou valores significantemente maiores do que o grupo WT nos períodos de 7 (p=0,001) e 21 dias (p=0,05), sendo que após 42 dias foi observada tendência de maiores valores, porém sem diferença significante (p=0,09). Foi observada maior quantidade de neutrófilos no grupo MyD88 KO, em comparação aos animais WT (p=0,01 em 7 dias; p=0,004 em 21 dias; e p<0,001 em 42 dias). Por outro lado, com relação à quantidade de osteoclastos, não foi observada diferença significante entre ambos os grupos, em todos os períodos experimentais (p=0,884 em 7 dias; p=0,506 em 21 dias; e p=0,211 em 42 dias). A análise microscópica descritiva do grupo MyD88 KO revelou um infiltrado inflamatório mais intenso, com presença abundante de células porlimorfonucleadas e mononucleadas e com grande destruição tecidual, após 7, 21 e 42 dias. A coloração de Brown e Brenn evidenciou uma maior disseminação bacteriana, inclusive nos tecidos periapicais, no grupo MyD88 KO, quando comparado aos animais WT. Com relação à imunohistoquímica, foram observadas marcações para RANK, RANKL e OPG de forma semelhante entre os dois grupos de animais. Com base nas metodologias e nos resultados obtidos no presente estudo pode-se concluir que na ausência da MyD88 os animais apresentaram lesões periapicais mais extensas, com um infiltrado inflamatório severo e com número significantemente maior de neutrófilos, quando comparados aos animais WT, sugerindo o importante papel desta molécula na resposta imune e inflamatória no combate à infecção de origem endodôntica. / The adaptor molecule myeloid differentiation primary response gene 88 (MyD88) is involved in the activation of toll-like receptors (TLRs), which are responsible for the early recognition by the host cells of invading pathogens and for triggering the immune response. The aim of the present study was to characterize the formation and progression of experimentally induced periapical lesions in teeth of MyD88 knockout (MyD88 KO) mice compared with wildtype (WT) mice. Periapical lesions were induced in the mandibular first molars of 30 WT and 30 MyD88 KO mice. After 7, 21 and 42 days, the animals were euthanized in a CO2 chamber and the mandibles were removed and subjected to histotechnical processing. Representative histological sections were stained with hematoxylin and eosin (HE) for description of the features of the root canal and the apical and periapical regions, and for counting of inflammatory cells (neutrophils) under conventional light microscopy and for determination of the size of the periapical lesions under fluorescence microscopy. Sequential specimens were evaluated by: TRAP histoenzymology, for osteoclast counting; Brown & Brenn staining, for localization of bacteria; and immunohistochemistry for identification of osteoclastogenesis markers (RANK, RANKL, OPG). Data were subjected to statistical analysis by the nonparametric Mann-Whitney and Kruskal-Wallis tests and the Dunn post-test, using the SPSS (Statistical Package for the Social Sciences) software, version 17.0. The significance level was set at 5%. The other analyzes were displayed qualitatively. Regarding the periapical lesion size, the MyD88 KO group presented significantly higher values than the WT group in the periods of 7 (p=0.001) and 21 days (p=0.05). Tendency for higher values was observed after 42 days, though without significant difference (p=0.09). A larger number of neutrophils in the MyD88 KO group were observed compared with the WT animals (p=0.01 at 7 days, p=0.004 at 21 days and p<0.001 at 42 days). On the other hand, regarding the number of osteoclasts, no statistically significant difference was observed between the groups at any of the experimental periods (p=0.884 at 7 days, p=0.506 at 21 days and p=0.211 at 42 days). Descriptive microscopic analysis of the MyD88 KO group revealed a more intense inflammatory infiltrate, with abundant presence of polymorphonuclear and mononuclear cells and wide tissue destruction, after 7, 21 and 42 days. Brown & Brenn staining showed an increased bacterial dissemination, including the periapical tissues in the MyD88 KO group, when compared with the WT animals. As for immunohistochemistry, RANK, RANKL and OPG immunostainings were similar between the two groups of animals. Based on the employed methodology and the obtained results, it may be concluded that in the absence of MyD88, the animals showed larger periapical lesions, with a severe inflammatory infiltrate and a significantly larger number of neutrophils, when compared with WT animals, suggesting the important role of this molecule during the immune and inflammatory response against infections of endodontic origin.

A molécula adaptadora myeloid differentiation primary response gene 88 (MyD88) está envolvida na ativação de receptores Toll-like (TLRs), os quais são responsáveis pelo reconhecimento precoce pelas células do hospedeiro de patógenos invasores e pelo desencadeamento da resposta imunológica. O objetivo do presente estudo foi caracterizar o desenvolvimento e a progressão de lesões periapicais induzidas experimentalmente em dentes de camundongos knockout (KO) para a molécula MyD88 (MyD88 KO), comparados a animais wild-type (WT). Lesões periapicais foram induzidas nos primeiros molares inferiores de 30 camundongos WT e de 30 camundongos MyD88 KO. Decorridos 7, 21 e 42 dias, os animais foram submetidos à eutanásia em câmara de CO2 e as mandíbulas foram removidas e submetidas ao processamento histotécnico. A seguir, cortes representativos foram corados com hematoxilina e eosina (HE), para descrição das características do canal radicular e das regiões apical e periapical e para contagem do número de células inflamatórias (neutrófilos), em microscopia de luz, e para mensuração da área das lesões periapicais, em microscopia de fluorescência. Espécimes sequenciais foram analisados por meio de: histoenzimologia para a atividade da TRAP, para contagem de osteoclastos; coloração de Brown & Brenn, para localização de bactérias; e imunohistoquímica, para identificação de marcadores da osteoclastogênese (RANK, RANKL e OPG). Os dados foram submetidos à análise estatística por meio dos testes não-paramétricos de Mann-Whitney, Kruskal-Wallis e pós-teste de Dunn, utilizando o programa SPSS (Statistical Package for the Social Sciences) versão 17.O, com nível de significância de 5%. As demais análises foram expressas de maneira qualitativa. Com relação à extensão das lesões periapicais, o grupo MyD88 KO apresentou valores significantemente maiores do que o grupo WT nos períodos de 7 (p=0,001) e 21 dias (p=0,05), sendo que após 42 dias foi observada tendência de maiores valores, porém sem diferença significante (p=0,09). Foi observada maior quantidade de neutrófilos no grupo MyD88 KO, em comparação aos animais WT (p=0,01 em 7 dias; p=0,004 em 21 dias; e p<0,001 em 42 dias). Por outro lado, com relação à quantidade de osteoclastos, não foi observada diferença significante entre ambos os grupos, em todos os períodos experimentais (p=0,884 em 7 dias; p=0,506 em 21 dias; e p=0,211 em 42 dias). A análise microscópica descritiva do grupo MyD88 KO revelou um infiltrado inflamatório mais intenso, com presença abundante de células porlimorfonucleadas e mononucleadas e com grande destruição tecidual, após 7, 21 e 42 dias. A coloração de Brown e Brenn evidenciou uma maior disseminação bacteriana, inclusive nos tecidos periapicais, no grupo MyD88 KO, quando comparado aos animais WT. Com relação à imunohistoquímica, foram observadas marcações para RANK, RANKL e OPG de forma semelhante entre os dois grupos de animais. Com base nas metodologias e nos resultados obtidos no presente estudo pode-se concluir que na ausência da MyD88 os animais apresentaram lesões periapicais mais extensas, com um infiltrado inflamatório severo e com número significantemente maior de neutrófilos, quando comparados aos animais WT, sugerindo o importante papel desta molécula na resposta imune e inflamatória no combate à infecção de origem endodôntica. / The adaptor molecule myeloid differentiation primary response gene 88 (MyD88) is involved in the activation of toll-like receptors (TLRs), which are responsible for the early recognition by the host cells of invading pathogens and for triggering the immune response. The aim of the present study was to characterize the formation and progression of experimentally induced periapical lesions in teeth of MyD88 knockout (MyD88 KO) mice compared with wildtype (WT) mice. Periapical lesions were induced in the mandibular first molars of 30 WT and 30 MyD88 KO mice. After 7, 21 and 42 days, the animals were euthanized in a CO2 chamber and the mandibles were removed and subjected to histotechnical processing. Representative histological sections were stained with hematoxylin and eosin (HE) for description of the features of the root canal and the apical and periapical regions, and for counting of inflammatory cells (neutrophils) under conventional light microscopy and for determination of the size of the periapical lesions under fluorescence microscopy. Sequential specimens were evaluated by: TRAP histoenzymology, for osteoclast counting; Brown & Brenn staining, for localization of bacteria; and immunohistochemistry for identification of osteoclastogenesis markers (RANK, RANKL, OPG). Data were subjected to statistical analysis by the nonparametric Mann-Whitney and Kruskal-Wallis tests and the Dunn post-test, using the SPSS (Statistical Package for the Social Sciences) software, version 17.0. The significance level was set at 5%. The other analyzes were displayed qualitatively. Regarding the periapical lesion size, the MyD88 KO group presented significantly higher values than the WT group in the periods of 7 (p=0.001) and 21 days (p=0.05). Tendency for higher values was observed after 42 days, though without significant difference (p=0.09). A larger number of neutrophils in the MyD88 KO group were observed compared with the WT animals (p=0.01 at 7 days, p=0.004 at 21 days and p<0.001 at 42 days). On the other hand, regarding the number of osteoclasts, no statistically significant difference was observed between the groups at any of the experimental periods (p=0.884 at 7 days, p=0.506 at 21 days and p=0.211 at 42 days). Descriptive microscopic analysis of the MyD88 KO group revealed a more intense inflammatory infiltrate, with abundant presence of polymorphonuclear and mononuclear cells and wide tissue destruction, after 7, 21 and 42 days. Brown & Brenn staining showed an increased bacterial dissemination, including the periapical tissues in the MyD88 KO group, when compared with the WT animals. As for immunohistochemistry, RANK, RANKL and OPG immunostainings were similar between the two groups of animals. Based on the employed methodology and the obtained results, it may be concluded that in the absence of MyD88, the animals showed larger periapical lesions, with a severe inflammatory infiltrate and a significantly larger number of neutrophils, when compared with WT animals, suggesting the important role of this molecule during the immune and inflammatory response against infections of endodontic origin.

A paracoccidioidomicose (PCM) é uma doença granulomatosa sistêmica, causada por Paracoccidioides spp., (P. brasiliensis e P. lutzii), geograficamente, limita-se a América Latina com as áreas endêmicas estendendo-se desde o México até a Argentina, constituindo uma das micoses sistêmicas de maior incidência na região, afetando principalmente trabalhadores rurais. O maior número de pacientes com PCM tem sido reportado principalmente no Brasil, Colômbia e Venezuela. A incidência real desta micose encontra-se subestimada no Brasil e pouco se conhece em relação a nova espécie descrita - P. lutzii. A maioria dos estudos em P. lutzii foram focados em genética, especiação e na geração de novos antígenos para melhorar a especificidade e sensibilidade dos testes sorológicos. Atualmente, as preparações antigênicas tradicionais, preparadas a partir de isolados de P. brasiliensis, são ineficientes. Raros são os trabalhos focados na biologia de P. lutzii e nos fatores de virulência que podem ser comparados com P. brasiliensis nos modelos experimentais. A nossa proposta de estudo foi avaliar alguns aspectos in vitro e in vivo relacionados com a patogenicidade e destacamos: a fagocitose e a morte intracelular de P. lutzii por macrófagos, peritoneais, de camundongos Knockouts (KO) e selvagens para PRRs (TLR2, TLR4 e Dectina) e ativadores intracelulares (MyD88 e NALP3). Paralelamente a este estudo, animais foram infectados com leveduras de P. lutzii e comparados com os modelos de infecção já estabelecidos com leveduras (Pb18) e conídios (ATCCPb60855) de P. brasiliensis. Nossos dados indicam que similar ao que ocorre com P. brasiliensis a fagocitose de P. lutzii depende de TLR2, TLR4 e Dectina- 1, resultados semelhantes também foram observadas na expressão de moléculas envolvidas na co-estimulação e a apresentação de antígenos (MHC II, CD80 e CD86). Contudo, a morte intracelular de leveduras de P. lutzii é claramente dependente de TLR4, e a produção de citocinas IL-6, MIP-2, IFN- e IL-12p40 são importantes para o controle das leveduras pelos macrófagos. No modelo experimental de P. lutzii, camundongos machos C57BL/6 (6-7 semanas) foram infectados intratraquealmente como 1x106 leveduras viáveis do isolado de P. lutzii Pb01. Encontramos duas fases da doença, a primeira de 0 hora até 2 a 4 semanas pós-infecção, e a segunda de 4 até 12 semanas. As leveduras parecem ser contidas na primeira semana de infecção e posteriormente não encontramos leveduras nos macerados de pulmão, diferente do modelo de BALB/c infetado com conídios de ATCC-Pb60855 no qual as UFC são recuperadas até a semana 16 pós-infeção. Como relação aos níveis de citocinas, encontramos que na lavagem broncoalveolar e macerado de pulmão um perfil misto Th1/Th2 porém, marcado por citocinas próinflamatórias no primeiro período e citocinas regulatórias tipo Th2 no segundo período (IL-12p70, IL-23, IL-10); similar ao descrito nos modelos de P. brasiliensis infectados tanto com conídios como com leveduras. No entanto, no primeiro período da doença, em camundongos C57BL/6, parece ter uma carga inflamatória maior que reflete nas citocinas que mantém seus níveis até o período crônico: TNF-alfa, MIP-2 e GM-CSF está última, regulada positivamente tanto em experimentos in vitro como in vivo. Também observamos que a partir das 48horas pós-infecção encontramos níveis aumentados de IL-12p70 até o período crônico onde junto com a IL-23 parecem ser as responsáveis pela diminuição da infecção no período tárdio. Esta é a primeira vez que se descreve um modelo experimental com P. lutzii (isolado Pb01) indicando o perfil imunopatológico com pequenas diferenças comparados ao P. brasiliensis porém, de importância na patogenicidade da doença auxiliando a compreender as diferentes formas da doença no modelo experimental / Paracoccidioidomycosis (PCM) is a systemic granulomatous disease caused by Paracoccidioides spp. (P. brasiliensis and P. lutzii), geographically, is limited to Latin America with endemic areas from Mexico to Argentina, as one of the systemic mycoses with the highest incidence in the region, mainly affecting rural workers. The largest number of patients with PCM has been mainly reported in Brazil, Colombia and Venezuela. The true incidence of this mycosis is underestimated in Brazil and little is known about the new species described - P. lutzii. Most studies in P. lutzii were focused on genetics, speciation and the generation of new antigens to improve the specificity and sensitivity of serological tests. Currently, traditional antigenic preparations, prepared with isolates of P. brasiliensis, are inefficient. There are few studies focused on P. lutzii biology and virulence factors that can be compared with P. brasiliensis in experimental models. Our study aimed to evaluate some in vitro and in vivo aspects related to pathogenicity: phagocytosis and intracellular killing of P. lutzii by peritoneal macrophages from knockouts (KO) for PRRs (TLR2, TLR4 and Dectin) and intracellular activators (MyD88 and NALP3). In addition, animals were infected with P. lutzii yeast and compared with the well-established models of infection with yeast cells (Pb18) and conidia (ATCC Pb60855) from P. brasiliensis. Our data indicate that similarly to what happens with the phagocytosis of P. brasiliensis, P. lutzii phagocytosis is dependent on TLR2, TLR4 and Dectin-1. Other molecules, involved in co-stimulation and presentation of antigens such as MHC II, CD80 and CD86 were also shown to participate in the P. lutzii-host interaction. However, intracellular killing of P. lutzii yeast cells was clearly dependent on TLR4, and the production of cytokines as IL-6, MIP-2, IFN- and IL-12p40 were important for the control of the yeast by macrophages. In the experimental model of P. lutzii, male C57BL/6 mice (6-7 weeks) were infected intratracheally with 1x106 viable yeasts of the isolate Pb01like. We found two phases of the disease, the first from the inoculation to 2 or 4 weeks after infection and the second from 4 to 12 weeks. Yeast appear to be contained within the first week of infection and subsequently are also absent from macerated lung, differently from the model of BALB/c mice infected with ATCC Pb60855 conidia in which CFUs were detected up to week 16 post-infection. We found a mixed Th1/Th2 pattern (IL-12p70, IL-23, IL-10) in bronchoalveolar lavage and lung, with the predominance of proinflammatory cytokines in the first phase and predominance of regulatory Th2 cytokines in the second phase, reproducing findings of P. brasiliensis infection models produced with both conidia and yeast. However, in the first period of the disease in C57BL/6 mice there was a higher inflammatory burden, reflected by the high cytokine levels (TNF-alpha, MIP-2 and GM-CSF), the latter in particular because it was positively regulated both in vitro and vivo), that persisted through the chronic period. We also observed that starting from 48 hours postinfection to the chronic period there were increased levels of IL-12p70, which together with IL-23 appeared to be responsible for the reduction of infection in the late period. This is the first time that an experimental model with P. lutzii (Pb01) is described, showing an immunological profile with only slight differences compared to the P. brasiliensis model. The present study details important aspects of the pathogenesis of the disease due to different species of Paracoccidioides and helps to understand the different forms of presentation in experimental models

O conhecimento de que o exercício é benéfico na doença aterosclerótica é baseado principalmente em estudos epidemiológicos. O objetivo deste trabalho foi investigar se o treinamento físico preventivo ou terapêutico altera a evolução da placa aterosclerótica. Camundongos LDLr-/- com 16 semanas de vida foram separados em dois programas: preventivo e terapêutico. Animais do programa preventivo receberam dieta normal ou aterogênica por 14 semanas. O treinamento físico foi iniciado concomitantemente ao início da dieta. Animais do programa terapêutico receberam dieta normal ou aterogênica por 28 semanas. O treinamento físico foi iniciado após 14 semanas do início da dieta, com placas bem estabelecidas. O treinamento físico aeróbico moderado foi realizado em esteira rolante, por 60 min, 5 dias/sem, durante 14 semanas. Massa corporal, pressão arterial caudal e freqüência cardíaca foram registradas. Lipoproteínas plasmáticas foram separadas por FPLC e colesterol total foi dosado por métodos enzimáticos. Foram quantificados tamanho, conteúdo de gordura e de colágeno da placa por coloração de oil-red O e picro-sirius. Citocinas TNF-, IL-6 foram medidas por Elisa. MMP-9 plasmática foi medida por zimografia. Marcadores inflamatórios teciduais, MMP-9, CD40/CD40L e nitrotirosina, foram medidos na placa por imunohistoquímica. O treinamento físico não modificou o tamanho da placa, mas tornou a placa mais estável por aumentar o conteúdo de colágeno. O treinamento físico diminuiu o conteúdo de gordura da placa, os fatores de risco e o CD40 somente no programa preventivo. Nenhuma alteração foi notada nos marcadores inflamatórios circulantes e na expressão de MMP-9 e formação de nitrotirosina na placa aterosclerótica. / The knowledge that exercise exerts beneficial effects on atherosclerotic disease is mainly based on epidemiological studies. Our aim was to investigate the effect of preventive and therapeutic exercise programs on atherosclerotic plaque formation and development. Sixteen-week-old LDLr-/- mice were randomly divided into preventive and therapeutic programs. Preventive programs mice received normal or atherogenic diet for 14 weeks. Exercise training started at the same time of dieting. Therapeutic programs mice received normal or atherogenic diet for 28 weeks. Exercise training started after 14 weeks of dieting when atherosclerosis plaques were already established. Moderate intensity aerobic exercise training was performed on a motor treadmill for 60 min, 5 days/wk, during 14 weeks. Body mass, caudal blood pressure and heart rate were registered. Plasma lipoproteins were separated by FPLC and total cholesterol was determined by enzymatic methods. Cross sections of aortic root were stained with oil-red O for plaque size and fat content. Aorta longitudinal sections were stained with picro-sirius for collagen content. TNF- and IL-6 cytokines were measured by Elisa. Plasmatic MMP-9 was determined by zimography. Inflammatory tissue markers, MMP-9, CD40/CD40L and nitrotirosine, were measured by immunohistochemistry. We concluded that exercise training did not modify plaque size, but turned it into a more stable one by increasing its collagen content. Exercise training reduced plaque fat content, risk factors and plaque CD40 expression only in the preventive program. No difference in systemic inflammatory markers, and in plaque MMP-9 expression and nitrotirosine formation was noted.

No description available.