Navegando por Palavras-chave "neurogenesis"
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- ItemAcesso aberto (Open Access)Biomateriais na reparação do sistema nervoso central: uso de nanofibras sintéticas biodegradáveis como suporte para transplante celular e nanopartículas contendo cxcl12 no recrutamento de células-tronco endógenas(Universidade Federal de São Paulo (UNIFESP), 2016-12-31) Zamproni, Laura Nicoleti [UNIFESP]; Porcionatto, Marimelia Porcionatto [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Central nervous system (CNS) disorders are highly debilitating and with few therapeutic options. Stem cells are a therapeutic promise for these diseases. The two main strategies described in literature are exogenous stem cells transplantation and enhancement of endogenous neurogenesis. Since both strategies pose problems, there is increasing research on the use of biomaterial to try to optimize cell engraftment and delivery of soluble factors that can increase neurogenesis. In this study, we evaluated polylactic acid (PLA) polymeric nanofibers (PNF) as carriers for cell transplantation and evaluated two formulations of poly(lactic-co-glycolic acid) (PLGA) for local delivery of CXCL12, a powerful chemokine to recruit neural stem cells (NSC). PNF were produced by jet-rotatory spinning and characterized by scanning electron microscopy. MSC and NSC obtained respectively from bone marrow and subventricular zone of C57BL/6 adult mice were cultured on PNF and transplanted into the brain of adult mice submitted to ischemic stroke model. Both cell types were viable when cultured on PNF, and MSC but not NSC were able to reduce the necrotic area. CXCL12 formulations were made by double emulsion. Two formulations were evaluated: microspheres (MS) and nanoparticles (NP). Both were able to encapsulate more than 80% of CXCL12, but showed different release profiles, with 100% CXCL12 released after 6 days for MS and 25% CXCL12 released after 2 weeks for NP. CXCL12 bioactivity was demonstrated by chemotaxis assay. When injected into the brains of mice submitted to traumatic brain injury model, only NP-CXCL12 induced CTN migration to the injured area. We conclude that the PNF are viable scaffolds for cell transplantation, MS and NP are suitable for soluble factor, such as CXCL12, delivery in two different brains injury model. Thus, we suggest that both approaches presented in this work could be tested as therapeutic strategies for CNS injuries.
- ItemSomente MetadadadosMaternal Consumption of High-fat Diet in Mice Alters Hypothalamic Notch Pathway, NPY Cell Population and Food Intake in Offspring(Pergamon-Elsevier Science Ltd, 2018) Lemes, Simone Ferreira; Parras de Souza, Anelise Cristina; Payolla, Tanyara Baliani; Versutti, Milena Diorio; da Silva Ramalho, Albina de Fatima; Mendes-da-Silva, Cristiano [UNIFESP]; Souza, Camilla Mendes; Milanski, Marciane; Torsoni, Adriana Souza; Torsoni, Marcio AlbertoStudies show that maternal consumption of a high-fat diet (HFD) can impair the formation of hypothalamic neuronal circuits in mouse offspring. This damage can be mediated by Notch1/Hes5 signaling activation, leading to repression of proneural factors such as Mash1 and Ngn2/3, which are essential for neuronal differentiation and neurogenesis. Thus, we aimed to investigate the effects of maternal HFD consumption during gestation and lactation on the Notch1/Mash1 pathway in the hypothalamus and arcuate nucleus (ARC) of mouse offspring (neonates and 28 days old). Our results showed that maternal HFD consumption increases body weight and adiposity of mouse offspring, accompanied by increased levels of Il-1 beta mRNA compared to those in control offspring. We noticed high mRNA levels of Hes5 accompanied by diminished mRNA levels of Ascl1 (Mash1). The number of Mash1-labeled cells in the ARC was diminished in HFD-O. Additionally, the population of NPY neurons was increased in these animals. Mash1 is important for the development of POMC and NPY neurons in the ARC. Therefore, the reduction in Mash1-labeled cells could be related to modification of the NPY neuron population in the ARC. This scenario favors hyperphagia and weight gain, and could be responsible for the development of obesity in adulthood. (C) 2017 IBRO. Published by Elsevier Ltd. All rights reserved.
- ItemAcesso aberto (Open Access)Neurogenesis induced by seizures in the dentate gyrus is not related to mossy fiber sprouting but is age dependent in developing rats(Academia Brasileira de Neurologia - ABNEURO, 2008-12-01) Sanabria, Yaima Del Carmen Garrido [UNIFESP]; Argañaraz, Gustavo Adolfo [UNIFESP]; Lima, Eliângela de [UNIFESP]; Priel, Margareth Rose [UNIFESP]; Trindade, Edvaldo da Silva [UNIFESP]; Loeb, Luana Mazzacoratti [UNIFESP]; Scorza, Fulvio Alexandre [UNIFESP]; Cavalheiro, Esper Abrão [UNIFESP]; Amado, Débora [UNIFESP]; Naffah-Mazzacoratti, Maria da Graca [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Neurogenesis in the dentate gyrus (DG) has attracted attention since abnormal supragranular mossy fiber sprouting occurs in the same region, in temporal lobe epilepsy. Thus, we submitted developing rats to pilocarpine-induced status epilepticus (SE) to study the relationship between neurogenesis and mossy fiber sprouting. Groups were submitted to SE at: I-P9, II-P7, P8 and P9, III-P17 e IV-P21. Neurogenesis was quantified using BrdU protocol and confirmed through double staining, using neuronal pentraxin. Other animals were monitored by video system until P120 and their brain was studied (Timm and Nissl staining). The neurogenesis at P17 (p=0.007) and P21 (p=0.006) were increased. However, only P21 group showed recurrent seizures and the mossy fiber sprouting in the same region, during adult life, while P17 did not. Thus, our results suggest that neurogenesis is not related to mossy fiber sprouting neither to recurrent spontaneous seizures in pilocarpine model.
- ItemSomente MetadadadosNovel Perspectives of Neural Stem Cell Differentiation: From Neurotransmitters to Therapeutics(Wiley-Blackwell, 2009-01-01) Trujillo, Cleber A.; Schwindt, Telma Tiemi [UNIFESP]; Martins, Antonio Henrique Baccin [UNIFESP]; Alves, Janaina Maria [UNIFESP]; Mello, Luiz Eugenio Araujo de Moraes [UNIFESP]; Ulrich, Henning; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP)In the past years, many reports have described the existence of neural progenitor and stem cells in the adult central nervous system capable of generating new neurons, astrocytes, and oligodendrocytes. This discovery has overturned the central assumption in the neuroscience field, of no new neurons being originated in the brain after birth and provided the fundaments to understand the molecular basis of neural differentiation and to develop new therapies for neural tissue repair. Although the mechanisms underlying cell fate during neural development are not yet understood, the importance of intrinsic and extrinsic factors and of an appropriate microenvironment is well known. in this context, emerging evidence strongly suggests that glial cells play a key role in controlling multiple steps of neurogenesis. Those cells, of particular radial glia, are important for migration, cell specification, and integration of neurons into a functional neural network. This review aims to present an update in the neurogenesis area and highlight the modulation of neural stem cell differentiation by neurotransmitters, growth factors, and their receptors, with possible applications for cell therapy strategies of neurological disorders. (C) 2008 international Society for Advancement of Cytometry
- ItemAcesso aberto (Open Access)Physical Exercise Restores the Generation of New born Neurons in an Animal Model of Chronic Epilepsy(Frontiers Media Sa, 2017) Mendonca, Fabricio N.; Santos, Luiz E. C.; Rodrigues, Antonio M.; da Silva, Sergio Gomes; Arida, Ricardo M. [UNIFESP]; da Silveira, Gilcelio A.; Scorza, Fulvio A. [UNIFESP]; Almeida, Antonio-Carlos G.Neurogenesis impairment is associated with the chronic phase of the epilepsy in humans and also observed in animal models. Recent studies with animal models have shown that physical exercise is capable of improving neurogenesis in adult subjects, alleviating cognitive impairment and depression. Here, we show that there is a reduction in the generation of newborn granule cells in the dentate gyrus of adult rats subjected to a chronic model of epilepsy during the postnatal period of brain development. We also show that the physical exercise was capable to restore the number of newborn granule cells in this animals to the level observed in the control group. Notably, a larger number of newborn granule cells exhibiting morphological characteristics indicative of correct targeting into the hippocampal circuitry and the absence of basal dendrite projections was also observed in the epileptic animals subjected to physical exercise compared to the epileptic animals. The results described here could represent a positive interference of the physical exercise on the neurogenesis process in subjects with chronic epilepsy. The results may also help to reinterpret the benefits of the physical exercise in alleviating symptoms of depression and cognitive dysfunction.
- ItemAcesso aberto (Open Access)Topical Dexamethasone Administration Impairs Protein Synthesis and Neuronal Regeneration in the Olfactory Epithelium(Frontiers Media Sa, 2018) Crisafulli, Umberto [UNIFESP]; Xavier, Andre Machado [UNIFESP]; Santos, Fabiana B. dos [UNIFESP]; Cambiaghi, Tavane David [UNIFESP]; Chang, Seo Y. [UNIFESP]; Porcionatto, Marimélia Aparecida [UNIFESP]; Castilho, Beatriz Amaral de [UNIFESP]; Malnic, Bettina; Glezer, Isaias [UNIFESP]Chronic inflammatory process in the nasal mucosa is correlated with poor smell perception. Over-activation of immune cells in the olfactory epithelium (OE) is generally associated with loss of olfactory function, and topical steroidal anti-inflammatory drugs have been largely used for treating such condition. Whether this therapeutic strategy could directly affect the regenerative process in the OE remains unclear. In this study, we show that nasal topical application of dexamethasone (DEX