Systems Biology Analysis of the Radiation-Attenuated Schistosome Vaccine Reveals a Role for Growth Factors in Protection and Hemostasis Inhibition in Parasite Survival.

In spite of several decades of research, an effective vaccine against schistosomiasis remains elusive. The radiation-attenuated (RA) cercarial vaccine is still the best model eliciting high protection levels, although the immune mechanisms have not yet been fully characterized. In order to identify genes and pathways underlying protection we investigated patterns of gene expression in PBMC and skin draining Lymph Nodes (LN) from mice using two exposure comparisons: vaccination with 500 attenuated cercariae versus infection with 500 normal cercariae; one versus three doses. Vaccinated mice were challenged with 120 normal parasites. Integration of PBMC and LN data from the infected group revealed early up-regulation of pathways associated with Th2 skewing and polarization of IgG antibody profiles. Additionally, hemostasis pathways were downregulated in infected mice, correlating with platelet reduction, potentially a mechanism to assist parasite migration through capillary beds. Conversely, up regulation of such mechanisms after vaccination may explain parasite blockade in the lungs. In contrast, a single exposure to attenuated parasites revealed early establishment of a Th1 bias (signaling of IL-1, IFN-γ; and Leishmania infection). Genes encoding chemokines and their receptors were more prominent in vaccinated mice, indicating an enhanced capacity for inflammation, potentially augmenting the inhibition of intravascular migration. Increasing the vaccinations from one to three did not dramatically elevate protection, but there was a clear shift towards antibody-mediated effectors. However, elements of the Th1 bias were still evident. Notable features after three vaccinations were markers of cytotoxicity (including IL-6 and NK cells) together with growth factors and their receptors (FGFR/VEGF/EGF) and the apoptosis pathway. Indeed, there is evidence for the development of anergy after three vaccinations, borne out by the limited responses detected in samples after challenge. We infer that persistence of a Th1 response puts a limit on expression of antibody-mediated mechanisms. This feature may explain the failure of multiple doses to drive protection towards sterile immunity. We suggest that the secretions of lung stage parasites would make a novel cohort of antigens for testing in protection experiments.

PKCζ-Mitogen-activated protein kinase signaling mediates crotalphine-Induced antinociception / A sinalização da proteína quinase ativada por PKCζ-mitógeno medeia a antinocicepção induzida por crotalfina

Crotalphine (CRP) is a structural analogue to a peptide that was first identified in the crude venom from the South American rattlesnake Crotalus durissus terrificus. This peptide induces a potent and long-lasting antinociceptive effect that is mediated by the activation of peripheral opioid receptors. The opioid receptor activation regulates a variety of intracellular signaling, including the mitogen-activated protein kinase (MAPK) pathway. Using primary cultures of sensory neurons, it was demonstrated that crotalphine increases the level of activated ERK1/2 and JNK-MAPKs and this increase is dependent on the activation of protein kinase Cζ (PKCζ). However, whether PKCζ-MAPK signaling is critical for crotalphine-induced antinociception is unknown. Here, we biochemically demonstrated that the systemic crotalphine activates ERK1/2 and JNK and decreases the phosphorylation of p38 in the lumbar spinal cord. The in vivo pharmacological inhibition of spinal ERK1/2 and JNK, but not of p38, blocks the antinociceptive effect of crotalphine. Of interest, the administration of a PKCζ pseudosubstrate (PKCζ inhibitor) prevents crotalphine-induced ERK activation in the spinal cord, followed by the abolishment of crotalphine-induced analgesia. Together, our results demonstrate that the PKCζ-ERK signaling pathway is involved in crotalphine-induced analgesia. Our study opens a perspective for the PKCζ-MAPK axis as a target for pain control.

Systems biology analysis of the radiation- attenuated schistosome vaccine reveals a role for growth factors in protection and hemostasis inhibition in parasite survival

In spite of several decades of research, an effective vaccine against schistosomiasis remains elusive. The radiation-attenuated (RA) cercarial vaccine is still the best model eliciting high protection levels, although the immune mechanisms have not yet been fully characterized. In order to identify genes and pathways underlying protection we investigated patterns of gene expression in PBMC and skin draining Lymph Nodes (LN) from mice using two exposure comparisons: vaccination with 500 attenuated cercariae versus infection with 500 normal cercariae; one versus three doses. Vaccinated mice were challenged with 120 normal parasites. Integration of PBMC and LN data from the infected group revealed early up-regulation of pathways associated with Th2 skewing and polarization of IgG antibody profiles. Additionally, hemostasis pathways were downregulated in infected mice, correlating with platelet reduction, potentially a mechanism to assist parasite migration through capillary beds. Conversely, up regulation of such mechanisms after vaccination may explain parasite blockade in the lungs. In contrast, a single exposure to attenuated parasites revealed early establishment of a Th1 bias (signaling of IL-1, IFN-γ; and Leishmania infection). Genes encoding chemokines and their receptors were more prominent in vaccinated mice, indicating an enhanced capacity for inflammation, potentially augmenting the inhibition of intravascular migration. Increasing the vaccinations from one to three did not dramatically elevate protection, but there was a clear shift towards antibody-mediated effectors. However, elements of the Th1 bias were still evident. Notable features after three vaccinations were markers of cytotoxicity (including IL-6 and NK cells) together with growth factors and their receptors (FGFR/VEGF/EGF) and the apoptosis pathway. Indeed, there is evidence for the development of anergy after three vaccinations, borne out by the limited responses detected in samples after challenge. We infer that persistence of a Th1 response puts a limit on expression of antibody-mediated mechanisms. This feature may explain the failure of multiple doses to drive protection towards sterile immunity. We suggest that the secretions of lung stage parasites would make a novel cohort of antigens for testing in protection experiments.

Estabelecimento de metodologia de diferenciação de células tronco embrionárias de camundongo em células precursoras de oligodendrócitos: uma plataforma para triagem de novas drogas remielinizantes / Establishment of a mouse embryonic stem cell line differentiation methodology into oligodendrocyte precursor cells: a platform for remyelinating drug screening.

The myelin sheath plays a crucial role in nerve function. In the Central Nervous System, the myelin sheath is produced by oligodendrocytes (OL), which are differentiated from oligodendrocyte precursor cells (OPC). Several neurological disorders, including multiple sclerosis, display damage in the myelin sheath and failure in the remyelination. Therefore, researching for new compounds that act in the OPCs differentiation to OLs is a promising strategy to treat demyelinating diseases. In this study, we established a methodology that allows the generation of OPCs in large quantities from two lineages of mouse embryonic stem cells (mESCs; lineages HM-1 and USP-1). Initially, mESCs were induced to differentiate into neural precursors and, later, to OPCs by adding growth factors such as FGF, EGF and PDGF. The characteristic and predominant expression of Olig2, Sox-10, PDGFRα and NG2 observed by immunofluorescence, and the double labeling of PDGFRα and NG2 by flow cytometry, confirmed the OPCs generation from mESCs. Therefore, this study shows an efficient and reproducible methodology for generating OPCs capable of being used in screening assays or in OLs lineage biology studies.

A bainha de mielina desempenha um papel crucial nas funções nervosas. No sistema nervoso central, a bainha de mielina é produzida por oligodendrócitos (OLs), os quais são diferenciados a partir de células precursoras de oligodendrócitos (OPCs). Em várias desordens neurológicas, entre elas, a Esclerose Múltipla, a bainha de mielina é danificada e a remielinização deixa de acontecer. Desse modo, a busca por novos compostos que atuem na diferenciação de OPCs a OLs, é um caminho promissor na terapia de doenças desmielinizantes. Neste estudo, estabelecemos uma metodologia que permitiu gerar OPCs a partir de duas linhagens de células tronco embrionárias de camundongos (mESCs – linhagens USP-1 e HM-1). Inicialmente, as mESCs foram induzidas a diferenciar em precursores neurais e, posteriormente, a OPCs, pela adição de fatores de crescimento como FGFb, EGF e PDGF-AA. A expressão característica e predominante de Olig2, Sox10, PDGFRα e NG2 observada por imunofluorescência e a dupla marcação de PDGFRα e NG2 por citometria de fluxo (com rendimentos de 88,3-87,3%) confirmaram a obtenção de OPCs a partir de mESCs. Estas células podem ser expandidas por 5 passagens adicionais e ainda serem capazes de gerar bilhões de OPC puros. Portanto, o estudo apresenta uma metodologia eficiente e reprodutível que permite a geração de um modelo a ser empregado em triagem de novas drogas ou no estudo da biologia da linhagem de OLs.

Stage and tissue expression patterns of Schistosoma mansoni venom allergen-like proteins SmVAL 4, 13, 16 and 24.

BACKGROUND: Schistosoma mansoni venom allergen-like protein (SmVAL) is a gene family composed of 29 members divided into group 1 encoding proteins potentially secreted, and group 2 encoding intracellular components. Some members were found to be upregulated in the transition of germ ball - cercariae - day 3 schistosomula, suggesting that group 1 SmVAL proteins are associated with the invasion of the human host, although their functions are not completely established. Recently, we have described the localization of SmVAL7 (group 1) and SmVAL6 (group 2) transcripts in the oesophageal gland and in the oral and ventral suckers of adult parasites, respectively. The expression patterns of the two genes suggest that SmVAL7 protein plays a role in the blood-feeding process while SmVAL6 is associated with the parasite attachment and movement in the vasculature. In this way, searching for additional secreted SmVAL proteins that could be involved in key processes from skin penetration to the beginning of blood-feeding, we investigated the tissue localization of SmVAL4, 13, 16 and 24 by whole-mount in situ hybridization (WISH). RESULTS: We report here the localization of group 1 SmVAL4 and 24 transcripts in the pre-acetabular glands of developing germ balls. Time course experiments of in vitro cultured schistosomula after cercariae transformation demonstrated that SmVAL4 protein is secreted during the first 3 h of in vitro culture, correlating with the emptying of acetabular glands as documented by confocal microscopy. In addition, the localization of SmVAL13 transcripts in adult male anterior oesophageal gland suggests that the respective protein may be involved in the first steps of the blood-feeding process. SmVAL16 was localized close to the neural ganglia and requires further investigation. CONCLUSIONS: Our findings demonstrate that SmVAL proteins have localizations that place them in strategic positions to be considered as potential vaccine candidates as some members are exposed to interaction with the immune system and may participate in key processes of mammalian invasion and parasitism establishment.

Stage and tissue expression patterns of Schistosoma mansoni venom allergen-like proteins SmVAL 4, 13, 16 and 24

Background: Schistosoma mansoni venom allergen-like protein (SmVAL) is a gene family composed of 29 members divided into group 1 encoding proteins potentially secreted, and group 2 encoding intracellular components. Some members were found to be upregulated in the transition of germ ball - cercariae - day 3 schistosomula, suggesting that group 1 SmVAL proteins are associated with the invasion of the human host, although their functions are not completely established. Recently, we have described the localization of SmVAL7 (group 1) and SmVAL6 (group 2) transcripts in the oesophageal gland and in the oral and ventral suckers of adult parasites, respectively. The expression patterns of the two genes suggest that SmVAL7 protein plays a role in the blood-feeding process while SmVAL6 is associated with the parasite attachment and movement in the vasculature. In this way, searching for additional secreted SmVAL proteins that could be involved in key processes from skin penetration to the beginning of blood-feeding, we investigated the tissue localization of SmVAL4, 13, 16 and 24 by whole-mount in situ hybridization (WISH). Results: We report here the localization of group 1 SmVAL4 and 24 transcripts in the pre-acetabular glands of developing germ balls. Time course experiments of in vitro cultured schistosomula after cercariae transformation demonstrated that SmVAL4 protein is secreted during the first 3 h of in vitro culture, correlating with the emptying of acetabular glands as documented by confocal microscopy. In addition, the localization of SmVAL13 transcripts in adult male anterior oesophageal gland suggests that the respective protein may be involved in the first steps of the blood-feeding process. SmVAL16 was localized close to the neural ganglia and requires further investigation. Conclusions: Our findings demonstrate that SmVAL proteins have localizations that place them in strategic positions to be considered as potential vaccine candidates as some members are exposed to interaction with the immune system and may participate in key processes of mammalian invasion and parasitism establishment.

Morfologia Floral de uma População de Tucumã, Astrocaryum aculeatum Meyer (Arecaceae) na Amazônia Central / Floral morphology of one population of Astrocaryum aculeatumMeyer (Arecaceae) in the Central Amazon-Brazil

Foi realizada a descrição morfológica das inflorescências, bem como das flores pistiladas e estaminadas, de uma população de Astrocaryum aculeatum Meyer, no Campus do Instituto Nacional de Pesquisas da Amazônia - INPA. A inflorescência é do tipo panícula de espigas, pedunculada, interfoliar e apresenta tamanho médio de 146 ± 20,3 cm. Uma bráctea lenhosa provida de espinhos em toda superfície externa protege a inflorescência. Estas apresentam cerca de 375 ± 49,5 ráquilas. Foi estimado de 500 a 1.200 flores pistiladas e 190.000 a 260.000 flores estaminadas por inflorescência. As flores estaminadas apresentam um padrão de cores que variam do vinho ao creme e também com tons mesclados de vinho e creme.

Morphological descriptions are provided for inflorescences of pistillate and staminate flowers of a population of Astrocaryum aculeatum Meyer located on the campus of the Instituto Nacional de Pesquisas da Amazônia (INPA). The inflorescence is an interfoliar, panicle of spikelets, with a peduncle, and medium size of 146 ± 20.3 cm in length. Woody, thorny bracts are present on the entire external surface, protecting the inflorescence. Each inflorescence had approximately 375 ± 49.5 rachillae. Each inflorescence was estimated to have about 500 to 1.200 pistillate flowers and 190.000 to 260.000 staminate flowers. Staminate flowers varied in colouration from wine to cream and intermediate mixes of wine and cream.

Atendimento nos serviços de emergência pediatrica da Fundaçäo Hospitalar do Distrito Federal, nas Regionais Sul, Taguatinga e Planaltina-DF / Pediatric Emergency Assistance at the Hospital Foundation of Distrito Federal, in the Sul Region, Taguatinga and Planaltina

Os servicos de emergencia pediatrica vem sendo desviados de sua principal funcao, prestando, com frequencia, atendimento em situacoes nao-emergenciais. Os autores deste estudo aplicaram um questionario aos acompanhantes dos pacientes (378) e fizeram um levantamento nas Guias de Atendimento de Emergencias correspondentes, no dia 21/05/96, das 8 as 18 horas. A entrevista visou identificar os principais motivos da nao-procura, por parte do acompanhante , ao centro de saude. A pesquisa nas GAEs buscou levantar o percentual de patologias que poderiam ser solucionadas nos centros de saude e a procedencia dos pacientes atendidos nos servicos pesquisados. Os resultados mostraram que a maioria dos entrevistados (67 por cento) nao procurou o centro de saude antes de irem ao servico de emergencia. O principal motivo apontado pelos acompanhantes, para a nao-procura do centro de saude, foi a dificuldade de marcacao de consultas neste ultimo (22,8 por cento), seguido pela caracterizacao do caso como emergencia, onde, de todos os casos caracterizados pelos acompanhantes como tal, apenas (27,8 por cento) foram de fato considerados emergencias pelos criterios adotados. Os dados mostraram ainda, que no dia e horarios pesquisados, 78 por cento dos atendimentos prestados nao foram considerados de emergencia, pelos criterios preestabelecidos, concluindo, desta forma, que a reforma do modelo de atencao e uma necessidade premente.