O desenvolvimento humano pode ser influenciado pelo ambiente. Estímulos recebidos ao longo da vida determinam seu progresso e sucesso. Estímulos positivos levam ao desenvolvimento de habilidades, melhorando funções cognitivas e da memória, enquanto estímulos negativos podem predispor a patologias como o estresse. Eventos estressantes durante a infância aumentam a predisposição para o desenvolvimento de transtornos psiquiátricos ao longo da vida. A separação materna, modelo animal de estresse pós-natal, promove diversas alterações comportamentais e encefálicas. Animais submetidos à separação materna apresentam comportamentos que mimetizam doenças psiquiátricas humanas. Por outro lado, diversos trabalhos sugerem que o enriquecimento ambiental pode ter efeito benéfico na reversão ou atenuação de modificações comportamentais e encefálicas promovidas por modelos animais de depressão, esquizofrenia, ansiedade e hiperatividade. Esses aspectos motivaram-nos a estudar se as alterações causadas por estresse podem ser revertidas ou atenuadas pelo enriquecimento do ambiente. Há evidências que sugerem um importante envolvimento de células gliais e de transportadores de glutamato presentes nessas células em modelos animais de transtornos psiquiátricos. Sendo assim, investigamos a expressão de mRNA e proteínas de dois transportadores de glutamato gliais e um neuronal, do receptor de glutamato AMPA, de marcadores gliais GFAP, S100?, glutamina sintase (GS) e do marcador de neurônios maduros NeuN na camada molecular e granular do giro denteado do hipocampo de ratos de 60 dias. Observamos que a separação materna diminui a expressão das proteínas GLAST, GLT-1, GS e NeuN, reduz a expressão dos genes Gria1 (AMPA) e S100?, e aumenta a expressão da proteína EAAC1 no giro denteado. Nossos dados sugerem uma reversão das alterações causadas pela separação materna em relação ao gene Gria1/AMPA e às proteínas GLAST, GLT-1 e EAAC1 após o enriquecimento ambiental. Portanto, o enriquecimento ambiental pode reverter as modificações causadas pela separação materna nas vias glutamatérgicas. Esses efeitos benéficos podem ser investigados para auxiliar no tratamento de transtornos psiquiátricos relacionados à separação materna. / Human development can be influenced by the environment. Stimuli received throughout life determine its progress and success. Positive stimuli lead to development of skills, improving cognitive and memory functions, while negative stimuli may predispose to pathologies such as stress. Stressful events during childhood increase the predisposition to psychiatric disorders throughout life. Maternal separation, an animal model of postnatal stress, promotes several behavioral and encephalic changes. Animals submitted to maternal separation stage behaviors associated with psychiatric diseases in humans. On the other hand, some researches have suggested that environmental enrichment may have some beneficial effects on the reversal or attenuation of behavioral and encephalic modifications promoted by animal models of depression, schizophrenia, anxiety and hyperactivity, which motivates us to study if these changes, stirred by this kind of stress, can be reversed or mitigated by environmental enrichment. There are evidences suggesting the involvement of glial cells and glutamate transporters existent in these cells in psychiatric disorders and animal models of these disorders. Therefore, we investigated mRNA and protein expression of two glial and one neuronal glutamate transporters, AMPA glutamate receptor, glial markers GFAP, S100?, glutamine synthase (GS), and the NeuN neuronal marker in the molecular and granular layer of the hippocampal gyrus in sixty-days-old rats. We observed that maternal separation decreases expression of GLAST, GLT-1, GS and NeuN proteins, reduces Gria1 (AMPA) and S100? gene expression, and increases EAAC1 protein expression in the dentate gyrus. After environmental enrichment, our data suggests a reversal of the maternal separation changes in the Gria1/AMPA gene and the GLAST, GLT-1 and EAAC1 proteins. Therefore, environmental enrichment may reverse the maternal separation changes in the glutamatergic pathways. These beneficial effects may be investigated to aid in the treatment of psychiatric disorders related to maternal separation.

Recentemente, com o intuito de identificar genes associados com invasão e proliferação tumoral, identificamos por PCR em tempo real, um aumento de aproximadamente cem vezes da proteína PLP2 em glioblastomas em relação a tecidos normais. Até o momento não há nenhum relato da identificação desta proteína em astrocitomas. Portanto, neste trabalho clonamos e expressamos em bactérias, as alças externas da PLP2 em fusão com a proteína SUMO, com o objetivo de obtermos anticorpos policlonais para serem usados na identificação da PLP2 em tumor humano por western blotting. Realizamos também a expressão da PLP2 fusionada com a EGFP em células de mamífero, para estudar sua distribuição celular, observamos que a PLP2 se concentra em toda a membrana celular e estudos sobre o transito da PLP2 nas células, indicam que ela possa estar envolvida em processos quimiotáticos via CCR1 sugerindo o envolvimento da PLP2 de alguma forma no processo tumorigênico. / Recently, in order to identify genes associated with tumoral invasion and proliferation, identified by real time PCR, an increase of about one hundred times of PLP2 protein in glioblastomas when compared to normal tissue. So far, there is no report of identification of this protein in astrocytomas. Therefore in this study, we cloned and expressed in bacteria the external handles of PLP2 fused with SUMO protein in order to obtain polyclonal antibodies for use in identifying the PLP2 in human tumor by western blotting. We also expressing the PLP2 fused with EGFP in mammalian cells to study its cellular distribution, we observed that focuses PLP2 across the cell membrane and studies on the traffic of PLP2 cells, indicate that it may be involved in chemotactic processes via CCR1 suggesting the involvement of PLP2 somehow in the tumorigenic process.

Agressões nos períodos críticos do crescimento do sistema nervoso podem modificar os eventos de desenvolvimento. Entre os vários fatores nocivos está a anóxia. O organismo do neonato tem suprimento de energia anaeróbica relativamente rica, foi observado que a acidose ocorre com menor facilidade, propiciam sobrevivência. A proteína de astrócitos, S100<font face=\"Symbol\">b, exerce efeitos parácrinos e autócrinos em neurônios e glia. Sua estimulação promove sobrevivência e proteção neuronal, atuando como fator trófico e neurotrófico. Modelo animal de anóxia neonatal desenvolvido em nosso laboratório, nos revelou ativação neural pela expressão de Fos e alterações comportamentais, o que nos instigou a explorar os efeitos da anóxia nas células da glia no Hipocampo e Núcleo do Trato Solitário. Para sua exposição à anoxia, durante 25 minutos, foi utilizada câmara, saturada com nitrogênio gasoso 100%. Grupos P2 e P7 nas condições: Basal (B), sem estimulo; Sham (S) como controle experimental e Anóxia (A) com falta de oxigênio, foram analisados por S100<font face=\"Symbol\">b-IR com técnicas ABC/DAB e Western blot. Observamos significante diferença de S100<font face=\"Symbol\">b-IR no núcleo do trato solitário, somente no grupo P2 A 2 h em relação ao grupo P2 S 2 h. A reatividade glial de S100<font face=\"Symbol\">b na formação hipocampal (CA1, CA3+CA2 e DG), apresentou diferença significante no grupo anoxia de acordo com o estágio de maturação do animal. A técnica por Western blot em toda a formação hipocampal, apresentou aumento de S100<font face=\"Symbol\">b no grupo A em ambos P2 e P7, a avaliação de um todo foi diferente daquela de áreas especificas. / Attacks to the nervous system at critical growth periods can modify developmental events. Among the various harmful factors at is anoxia. The high anaerobic energy supply to the newborn and a less easily acidosis occurrence provides survival. The astrocyte S100<font face=\"Symbol\">b protein exerts paracrine and autocrine effects on neurons and glia. Its stimulation promotes neuronal survival and protection, as a trophic and neurotrophic factor. An animal model of neonatal anoxia improved in our lab revealed neural activation by Fos expression and behavioral changes, which prompted us to explore the anoxia effects on glial cells in the Hypocampus and Nucleus of Solitary Tract. For their exposure to anoxia, a chamber, saturated with 100% nitrogen gas, for 25 minutes were used. Groups with P2 and P7, conditions: Baseline, without stimulation; Sham as the experimental control, and Anoxia with lack of oxygen, were evaluated by S100<font face=\"Symbol\">b-IR by ABC/DAB and Western blot techniques. The nucleus of solitary tract, significant different S100<font face=\"Symbol\">b-IR observed, only in the P2 A 2 h compared to P2 S 2 h. The glial S100<font face=\"Symbol\">b-IR at the hippocampal formation (CA1, CA2 + CA3 and DG) presented significant difference in the anoxic group according to the maturational stage of the animal. Western blot technique of the entire hippocampal formation, showed increase of S100<font face=\"Symbol\">b at the group A at both P2 and P7, the whole evaluation was different from of that of specific areas.

A Esclerose Lateral Amiotrófica (ELA) é uma doença neurodegenerativa de caráter progressivo caracterizada pela morte seletiva de neurônios motores que leva rapidamente os pacientes à morte. O camundongo transgênico que expressa a superóxido dismutase 1 humana mutante é o modelo experimental mais aceito para o estudo da doença. Os mecanismos que levam a perda neuronal ainda são pouco conhecidos e não existe tratamento eficaz para prolongar a vida do indivíduo. Estudos recentes indicam que as células gliais aceleram o processo neurodegenerativo, entretanto os mecanismos moleculares ainda não estão estabelecidos. Os astrócitos merecem uma atenção particular, pois apresentam íntima interação com os neurônios, fornecendo suporte estrutural, metabólico e trófico. Além disso, participam ativamente da modulação excitatória neuronal e da neurotransmissão, controlando os níveis extracelulares de íons e neurotransmissores. O presente estudo propôs investigar in vitro os possíveis dos astrócitos extraídos da medula espinal do camundongo de idade neonatal (P1) e adulta pré-sintomática (P60) sobre a morte de neurônios motores na ELA. Para isso, o trofismo e sobrevida do neurônio motor espinal foram avaliados nas culturas de neurônios motores tratados com meio condicionado de astrócitos e também em sistemas de co-culturas neurônios motores/astrócitos, de origem SOD1G93A (transgênica) e selvagem (wild type) em diferentes combinações. Investigou-se ainda, a expressão gênica de genes nos astrócitos nas culturas P1 e P60 realizadas através do PCR quantitativo (qPCR) e a quantificação de moléculas secretadas pelos astrócitos por ELISA Sanduíche. Para o estudo do trofismo e degeneração neuronal, as células foram marcadas com marcadores específicos de morte neuronal e o trofismo dos neurônios também foi quantificado por contraste de fase. As células foram quantificadas por métodos estereológicos específicos e as análises mostraram que o tratamento com meio condicionado de astrócitos transgênicos P1 e P60 causaram respectivamente retrações nos prolongamentos e morte dos neurônios transgênicos. As análises da morte neuronal dos meios condicionados e co-cultura mostraram que os astrócitos transgênicos de ambas as idades causaram a morte de neurônios wild type e apenas os astrócitos transgênicos P60 levaram os maiores perfis de morte nos neurônios transgênicos, demonstrando a toxidade dessas células. Quanto à análise da expressão gênica, os genes NKRF, UBE2I e TGFA mostraram-se diferencialmente expressos nos astrócitos transgênicos P1 e os genes HIPK3, TGFA e NTF5 diferencialmente expressos nos astrócitos transgênicos P60. Nas análises das moléculas secretadas nos meios condicionados maior quantidade de NGF foi encontrada no meio dos astrócitos transgênicos P60 comparando-se aos astrócitos wild type. A quantidade de IGF-I diminuiu no meio condicionado da cultura de astrócitos transgênicos P60 comparando-se aos astrócitos wild type E ainda, há a diminuição autócrina de TNF-? e IL-6 nos astrócitos transgênicos P60. Os astrócitos transgênicos parecem promover a toxicidade ao neurônio motor na ELA e moléculas liberadas pelos astrócitos parecem estar envolvidas no processo de desenvolvimento da ELA / Amyotrophic Lateral Sclerosis (ALS) is a neurodegenerative disease characterized by selective motor neurons death that readly leads patients to death. Transgenic mice expressing human mutant superoxide dismutase 1 (hSOD1) is the most accepted experimental model for the disease studying. The mechanisms that lead to neuronal loss are still poorly understood and there is no effective treatment able to prolong the pacient\'s life. Recent studies indicate that glial cells accelerate the neurodegenerative process, but the molecular mechanisms are not yet established. Astrocytes deserve particular attention, since they have close interaction with neurons, providing structural, metabolic and trophic support. In addition, they also participate actively in the neuronal excitatory modulation and in neuronal transmission, controlling ions and neurotransmitters at extracellular levels. The present study aimed to investigate the possible in vitro effects in astrocytes on the motor neurons death in ALS from newborn (P1) and adult pre symptomatic (P60) spinal cord mice. Thus, we evaluated spinal motor neuron survival and trophism in cultures treated with astrocytes conditioned medium and also in co-culture neuron/astrocyte systems of SOD1G93A (transgenic) and wild type in different cells combinations. Still, we investigated genes expression related to P1 and P60 astrocytes cultures performed by quantitative PCR (qPCR) and the molecules secreted by astrocytes were quantified by Sandwich ELISA. For the neuronal degeneration and trophism study, cells were immunostained with specific markers and neurouns were also visualized by phase contrast. These cells were quantified by stereological method and their analysis showed that treatment with transgenic P1 and P60 astrocytes conditioned medium cause length retractions and death on transgenic motor neuron. But, the neuronal death on conditioned medium and co-cultures experiments showed that transgenic P1 and P60 astrocytes caused wild type neuronal death and only transgenic P60 astrocytes led transgenic neurons death, demonstrating major toxicity of transgenic astrocytes. For the gene expression analysis NKRF, UBE2I and TGFa genes showed differentially expressed in transgenic P1 astrocytes and HIPK3, TGFa and NTF5 genes showed differentially expressed in transgenic P60 astrocytes. The analizes of molecules secreted by conditioned media a larger amount of NGF was found in transgenic P60 astrocytes comparing to wild type astrocytes. The amount of IGF-I in the conditioned medium was reduced in astrocytes transgenic P60 cultures compared to the wild type astrocytes Also, there is a reduction autocrine of TNF-? and IL-6 on transgenic astrocytes P60. The transgenic astrocytes seem to promote motor neuron toxicity in ALS and molecules released by astrocytes appear to be involved in the ALS development

A esclerose multipla (EM) é uma doença neurodegenerativa autoimune. As células da glia contribuem para o agravamento da EAE. Este trabalho objetiva mostrar a influência da dexametasona, na progressão da doença e nos défcits cognitivos da EAE. Foram utilizados camundongos C57BL/6, fêmeas, divididos em 4 grupos (CONT, DEX, EAE, EAE+DEX) imunizadas com MOG e Bordetella Pertussis, tratados com dexametasona (50mg/kg). Antes e após o aparecimento dos sintomas, os animais foram submetidos a testes comportamentais de campo aberto, labirinto em cruz elevado, contexto aversivo e reconhecimento de objetos. Os animais tratados com dexametasona (EAE+DEX) apresentaram diminuição do escore clínico em relação ao grupo EAE e apresentaram comportamento do tipo ansioso. Entretanto, o tratamento com DEX promoveu diminuição da memória de trabalho. Houve aumento marcadores inflamatórios e aumento do número de astrócitos no hipocampo do grupo EAE+DEX no 26o dia. Estes dados sugerem que a dexametasona diminui a aquisição da memória e aumenta o número e reatividade astrocitária na EAE. / Multiple sclerosis (MS) is an autoimmune neurodegenerative disease. The glial cells contribute to the aggravation of EAE. This work aims to show an influence of dexamethasone, the progression of the disease and the cognitive deficits of EAE. Female C57BL/6 mice were divided into 4 groups (CONT, DEX, EAE, EAE+DEX) immunized with MOG and Bordetella Pertussis, treated with dexamethasone (50mg/kg). Before and after the onset of symptoms, the animals were submitted to behavioral tests open field, the elevated plus maze, the aversive context and the object recognition test. The animals treated with dexamethasone (EAE+DEX) presented a decrease in the clinical score in relation to the EAE group and presented an anxious type behavior. However, treatment with DEX promoted a decrease in the work memory. There were increased inflammatory markers and increased number of hippocampal astrocytes from the EAE+DEX group on the 26th day. These data suggest that dexamethasone decreases memory acquisition and increases the astrocytic number and reactivity in EAE.

by Leung, Chi Ting Gideon. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1995. / Includes bibliographical references (leaves 72-86). / Acknowledgement / List of Abbreviations / Abstract --- p.i / Chapter Chapter 1 --- Introduction / Chapter 1.1 --- Parkinson's disease --- p.1 / Chapter 1.1.1 --- Epidemiology --- p.1 / Chapter 1.1.2 --- Symptoms --- p.1 / Chapter 1.1.3 --- Pathology --- p.3 / Chapter 1.1.4 --- Etiology --- p.4 / Chapter 1.2 1 --- "-Methyl-4-Phenyl-1,2,3,6-Tetrahydropyridine (MPTP)" --- p.5 / Chapter 1.2.1 --- History --- p.5 / Chapter 1.2.2 --- MPTP induced Parkinson's disease --- p.6 / Chapter 1.2.2.1 --- The metabolism of MPTP --- p.6 / Chapter 1.2.2.2 --- MPTP neurotoxicity --- p.9 / Chapter 1.2.2.3 --- MPTP analogs --- p.11 / Chapter 1.3 --- Factors involved in the degenerative process of Parkinson's disease --- p.12 / Chapter 1.3.1 --- Mitochondrial defect --- p.13 / Chapter 1.3.2 --- Oxidative stress --- p.14 / Chapter 1.3.2.1 --- Free Radicals --- p.14 / Chapter 1.3.2.2 --- Superoxide radicals --- p.14 / Chapter 1.3.2.3 --- Hydrogen peroxide --- p.16 / Chapter 1.3.2.4 --- Hydroxyl radicals --- p.17 / Chapter 1.3.3 --- Lipid peroxidation --- p.18 / Chapter 1.4 --- Antioxidants --- p.22 / Chapter 1.4.1 --- Introduction --- p.22 / Chapter 1.4.2 --- Glutathione and related enzymes --- p.25 / Chapter 1.4.2.1 --- Glutathione --- p.25 / Chapter 1.4.2.2 --- Glutathione peroxidase --- p.29 / Chapter 1.4.2.3 --- Glutathione reductase --- p.30 / Chapter 1.5 --- Astrocytes --- p.31 / Chapter 1.5.1 --- Introduction --- p.31 / Chapter 1.5.2 --- Role of astrocytes in PD --- p.34 / Chapter 1.6 --- Aim of the project --- p.35 / Chapter Chapter 2 --- Materials And Methods / Chapter 2.1 --- Astrocyte cultures --- p.38 / Chapter 2.2 --- MPTP treatment --- p.40 / Chapter 2.3 --- Lactate dehydrogenase (LDH) assay --- p.41 / Chapter 2.4 --- DTNB-GSSG reductase recycling assay for total GSH --- p.43 / Chapter 2.5 --- DTNB-GSSG reductase recycling assay for GSSG --- p.44 / Chapter 2.6 --- Glutathione peroxidase --- p.45 / Chapter 2.7 --- Glutathione reductase --- p.48 / Chapter 2.8 --- Statistics --- p.49 / Chapter Chapter 3 --- Results / Chapter 3.1 --- Change in lactate dehydrogenase (LDH) activities after MPTP treatment --- p.50 / Chapter 3.2 --- Change in total glutathione (GSH+GSSG) levels in astrocytes after different concentrations of MPTP treatment --- p.51 / Chapter 3.3 --- Change in glutathione and related enzyme activities in astrocytes after MPTP treatment --- p.51 / Chapter 3.3.1 --- Change in total glutathione (GSH+GSSG) levels --- p.51 / Chapter 3.3.2 --- Change in oxidized glutathione (GSSG) level in astrocytes after MPTP treatment --- p.54 / Chapter 3.3.3 --- Change in oxidized glutathione and total glutathione ratioin astrocytes after MPTP treatment --- p.56 / Chapter 3.3.4 --- Change in glutathione peroxidase activity after MPTP treatment --- p.57 / Chapter 3.3.5 --- Change in glutathione reductase activity after MPTP treatment --- p.59 / Chapter Chapter 4 --- Discussion And Conclusion --- p.61 / Chapter Chapter 5 --- References --- p.72

by Chang Chuen Chung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1993. / Includes bibliographical references (leaves 125-140). / Acknowledgement --- p.4 / List of Abbreviations --- p.5 / Abstract --- p.7 / Chapter CHAPTER I --- INTRODUCTION --- p.10 / Chapter 1.1 --- Astrocytes in the Central Nervous System --- p.10 / Chapter 1.1.1 --- Characteristics of astrocytes --- p.10 / Chapter 1.1.2 --- Functional roles of astrocytes --- p.11 / Chapter 1.1.2.1 --- General functions of astrocytes --- p.11 / Chapter 1.1.2.2 --- Volume regulation of astrocytes in CNS injuries --- p.12 / Chapter 1.1.2.3 --- Immunological functions of astrocytes --- p.13 / Chapter 1.2 --- Taurine in the CNS --- p.15 / Chapter 1.2.1 --- The biochemistry and distribution of taurine --- p.15 / Chapter 1.2.2 --- Physiological functions of taurine in the CNS --- p.19 / Chapter 1.2.3 --- Uptake and release of taurine by cultured astrocytes --- p.20 / Chapter 1.2.3.1 --- Taurine uptake in astrocytes --- p.21 / Chapter 1.2.3.2 --- Taurine release in astrocytes --- p.22 / Chapter 1.3 --- Tumor necrosis factor in the CNS --- p.23 / Chapter 1.3.1 --- Characteristics of tumor necrosis factor --- p.23 / Chapter 1.3.2 --- Sources of TNF in the CNS --- p.25 / Chapter 1.3.3 --- Functions of TNF in the CNS --- p.26 / Chapter 1.3.4 --- TNF and signal transduction --- p.27 / Chapter 1.4 --- cGMP second messenger system in astrocyte --- p.29 / Chapter 1.4.1 --- cGMP as second messenger in astrocytes --- p.29 / Chapter 1.4.2 --- Post cGMP cascade effects --- p.30 / Chapter 1.5 --- The aims of this project --- p.30 / Chapter CHAPTER II --- METHODS --- p.34 / Chapter 2.1 --- Primary astrocytes culture --- p.34 / Chapter 2.1.1 --- Primary rat astrocytes culture --- p.34 / Chapter 2.1.2 --- Primary mouse astrocytes culture --- p.36 / Chapter 2.1.3 --- Culture of rat C6 glioma cell line --- p.36 / Chapter 2.1.4 --- Subculture of astrocytes in different media --- p.37 / Chapter 2.2 --- Taurine uptake and release assay --- p.39 / Chapter 2.2.1 --- Taurine uptake assay --- p.39 / Chapter 2.2.2 --- Taurine release assay --- p.41 / Chapter 2.3 --- The effects of TNF on taurine transport --- p.42 / Chapter 2.4 --- The effects of TNF on cell volume in astrocytes --- p.43 / Chapter 2.5 --- "The effects of TNF on amino acids, glucose and neurotransmitters uptake" --- p.43 / Chapter 2.5.1 --- The effects of TNF on amino acids uptake --- p.43 / Chapter 2.5.2 --- The effects of TNF on glucose uptake --- p.44 / Chapter 2.5.3 --- The effects of TNF on neurotransmitters uptake --- p.45 / Chapter 2.6 --- The effects of LPS on taurine uptake in astrocytes --- p.46 / Chapter 2.7 --- The effects of IFN-¡’ on taurine uptake in astrocytes --- p.46 / Chapter 2.8 --- The effects of PMA on taurine uptake in astrocytes --- p.47 / Chapter 2.9 --- "The effects of TNF on thymidine, uridine and leucine incorporation in astrocytes" --- p.47 / Chapter 2.10 --- The effects of TNF on basal level of cGMP in astrocytes --- p.48 / Chapter 2.11 --- The effects of TNF on protein phosphorylation in astrocytes --- p.49 / Chapter 2.12 --- The effects of TNF on calcium uptake in astrocytes --- p.50 / Chapter CHAPTER III --- RESULTS --- p.51 / Chapter 3.1 --- The effects of TNF on taurine transport in cultured rat astrocytes --- p.51 / Chapter 3.1.1 --- The effects of TNF on [3H]-taurine uptake -time course study --- p.52 / Chapter 3.1.2 --- The effects of TNF on the kinetic parameters of the taurine uptake system --- p.54 / Chapter 3.1.3 --- The effects of TNF concentration on taurine uptake --- p.63 / Chapter 3.1.4 --- The effects of TNF exposure time on taurine uptake --- p.65 / Chapter 3.1.5 --- The effects of TNF on cell volume change in astrocytes --- p.67 / Chapter 3.1.6 --- "Comparison of the effects of TNF on taurine uptake amongst cultured primary rat astrocytes, primary mouse astrocytes and C6 glioma cell line" --- p.69 / Chapter 3.1.7 --- The effects of TNF on taurine release --- p.71 / Chapter 3.1.8 --- The specificity of the effects of TNF on taurine uptake --- p.74 / Chapter 3.1.8.1 --- The effects of TNF on the uptake of amino acids and glucose in primary rat astrocytes --- p.79 / Chapter 3.1.8.2 --- The effects of TNF on neurotransmitters uptake --- p.87 / Chapter 3.1.9 --- The effects of LPS on taurine uptake in astrocytes --- p.92 / Chapter 3.1.10 --- The effects of IFN-¡’ on taurine uptake in astrocytes --- p.97 / Chapter 3.1.11 --- The effects of PMA on taurine uptake --- p.99 / Chapter 3.2 --- The effects of TNF on cell metabolism in rat astrocytes --- p.102 / Chapter 3.2.1 --- The effects of TNF on astrocyte proliferation --- p.102 / Chapter 3.2.2 --- The effects of TNF on RNA synthesis --- p.103 / Chapter 3.2.3 --- The effects of TNF on protein synthesis --- p.106 / Chapter 3.2.4 --- The effects of TNF on basal level of cGMP --- p.108 / Chapter 3.2.5 --- The effects of TNF on protein phosphorylation --- p.111 / Chapter 3.2.6 --- The effects of TNF on calcium uptake --- p.113 / Chapter Chapter IV --- DISCUSSION AND CONCLUSION --- p.116 / References --- p.125

by Wong Kin Ling. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 348-373). / Abstracts in English and Chinese. / Abstract --- p.ii / 撮要 --- p.iv / Acknowledgements --- p.vi / Table of Contents --- p.vii / List of Abbreviations --- p.xviii / List of Tables --- p.xxi / List of Figures --- p.xxii / Chapter CHAPTER 1. --- INTRODUCTION / Chapter 1.1. --- Events happened in brain injury --- p.1 / Chapter 1.2. --- An alternate approach based on neuronal regeneration --- p.3 / Chapter 1.3. --- Fate of astrocytes after brain injury --- p.4 / Chapter 1.3.1. --- General information of astrocytes --- p.4 / Chapter 1.3.2. --- Functions of astrocytes --- p.5 / Chapter 1.4. --- Factors relate to astrocytes proliferation --- p.7 / Chapter 1.4.1. --- TNF-α --- p.8 / Chapter 1.4.2. --- β adrenergic mechanism and astrocyte proliferation --- p.11 / Chapter 1.5. --- Cell cycle-related proteins --- p.13 / Chapter 1.5.1. --- Maturation promoting factor (MPF) --- p.15 / Chapter 1.5.2. --- Early G1 phase --- p.16 / Chapter 1.5.3. --- Retinoblastoma protein (pRb) --- p.18 / Chapter 1.5.4. --- Cyclin-dependent kinase (cdk) activating kinase (Cak) --- p.19 / Chapter 1.5.5. --- "Cyclin, cdks, cki" --- p.20 / Chapter 1.5.5.1. --- Cyclins --- p.20 / Chapter 1.5.5.1.1. --- Cyclin D --- p.21 / Chapter 1.5.5.1.2. --- Cyclin E --- p.22 / Chapter 1.5.5.1.3. --- Cyclin A --- p.23 / Chapter 1.5.5.1.4. --- Cyclin B --- p.23 / Chapter 1.5.5.2. --- Cyclin-dependent kinases (cdks) --- p.24 / Chapter 1.5.5.3. --- Cyclin-dependent kinase inhibitor (cki) --- p.24 / Chapter 1.5.5.3.1. --- INK4 proteins (inhibitors of cdk-4 and cdk-6) --- p.25 / Chapter 1.5.5.3.2. --- p21 family proteins --- p.25 / Chapter 1.5.5.3.2.1. --- p21 --- p.25 / Chapter 1.5.5.3.2.2. --- p27 --- p.25 / Chapter 1.6. --- Apoptosis related proteins --- p.26 / Chapter 1.6.1. --- bcl-2 family --- p.26 / Chapter 1.6.1.1. --- bcl-2 --- p.26 / Chapter 1.6.1.2. --- bcl-x --- p.27 / Chapter 1.6.1.3. --- bcl-xα --- p.27 / Chapter 1.6.1.4. --- bcl-w --- p.28 / Chapter 1.6.1.5. --- Myeloid cell leukemia factor 1 (Mcl-1) --- p.28 / Chapter 1.7. --- C6 glioma cell line --- p.28 / Chapter 1.8. --- Aim of this project --- p.30 / Chapter CHAPTER 2. --- MATERIALS & METHODS / Chapter 2.1. --- Materials / Chapter 2.1.1. --- Rat C6 glioma cell line --- p.32 / Chapter 2.1.2. --- Cell culture materials preparation / Chapter 2.1.2.1. --- Complete Dulbecco's Modified Medium (cDMEM) --- p.32 / Chapter 2.1.2.2. --- Serum-free Dulbecco's Modified Medium (sDMEM) --- p.33 / Chapter 2.1.2.3. --- Phosphate buffered saline (PBS) --- p.33 / Chapter 2.1.3. --- Drug preparation / Chapter 2.1.3.1. --- Recombinant cytokines --- p.34 / Chapter 2.1.3.2. --- Antibodies / Chapter 2.1.3.2.1. --- Antibodies used in expression analysis --- p.34 / Chapter 2.1.4. --- Antibodies used in Western blotting --- p.34 / Chapter 2.1.5. --- Reagents for RNA isolation --- p.36 / Chapter 2.1.6. --- Reagents for reverse transcription-polymerase chain reaction (RT-PCR) --- p.36 / Chapter 2.1.7. --- Reagents for Electrophoresis --- p.38 / Chapter 2.1.8. --- Reagents and buffers for Western blotting --- p.38 / Chapter 2.1.9. --- Other chemicals and reagents --- p.39 / Chapter 2.2. --- Methods / Chapter 2.2.1. --- Maintenance of C6 cells --- p.39 / Chapter 2.2.2. --- Preparation of cells for assays --- p.40 / Chapter 2.2.3. --- Drugs preparation --- p.40 / Chapter 2.2.4. --- Determination of RNA expression by RT-PCR analysis / Chapter 2.2.4.1. --- RNA extraction --- p.41 / Chapter 2.2.4.2. --- Spectrophotometric Quantitation of DNA and RNA --- p.43 / Chapter 2.2.4.3. --- RNA gel electrophoresis --- p.43 / Chapter 2.2.4.4. --- Reverse transcription-polymerase chain reaction (RT- PCR) --- p.43 / Chapter 2.2.4.5. --- Separation of PCR products by agarose gel electrophoresis --- p.43 / Chapter 2.2.4.6. --- Quantification of band density --- p.45 / Chapter 2.2.4.7. --- Restriction enzyme (RE) digestion --- p.45 / Chapter 2.2.5. --- Determination of protein expression by Western blotting / Chapter 2.2.5.1. --- Total protein extraction --- p.46 / Chapter 2.2.5.2. --- Western blotting analysis --- p.46 / Chapter CHAPTER 3. --- RESULTS / Chapter 3.1. --- Effects of TNF-α on cell cycle related genes and proteins expression --- p.49 / Chapter 3.1.1. --- Effects of TNF-α on the time courses of cyclin D1 gene and protein expression --- p.49 / Chapter 3.1.2. --- Effect of TNF-α on the time course of cyclin D2 gene expression --- p.50 / Chapter 3.1.3. --- Effects of TNF-α on the time courses of cyclin D3 gene and protein expression --- p.53 / Chapter 3.1.4. --- Effects of TNF-α on the time courses of cdk-4 gene and protein expression --- p.55 / Chapter 3.1.5. --- Effects of TNF-α on the time courses of cyclin E gene and protein expression --- p.55 / Chapter 3.1.6. --- Effects of TNF-α on the time courses of cdk-2 gene and protein expression --- p.58 / Chapter 3.1.7. --- Effects of TNF-α on the time courses of p15 gene and protein expression --- p.61 / Chapter 3.1.8. --- Effects of TNF-α on the time courses of p27 gene and protein expression --- p.61 / Chapter 3.1.9. --- Effects of TNF-α on the time courses of p21 gene and protein expression --- p.64 / Chapter 3.1.10. --- Effects of TNF-α on the time courses of p130 gene and protein expression --- p.66 / Chapter 3.1.11. --- Effects of TNF-α on the time courses of Cak gene and protein expression --- p.66 / Chapter 3.1.12. --- Effects of TNF-α on the time courses of cyclin H gene and protein expression --- p.68 / Chapter 3.1.13. --- Effects of TNF-α on the time courses of cyclin B gene and protein expression- --- p.71 / Chapter 3.1.14. --- Effect of TNF-α on the time course of bcl-2 protein expression --- p.71 / Chapter 3.1.15. --- Effects of TNF-α on the time courses of bcl-XL gene and protein expression --- p.73 / Chapter 3.1.16. --- Effect of TNF-α on the time course of bcl-xα gene expression --- p.73 / Chapter 3.1.17. --- Effects of TNF-α on the time courses of bcl-w gene and protein expression --- p.76 / Chapter 3.1.18. --- Effects of TNF-α on the time courses of Mcl-1 gene expression --- p.76 / Chapter 3.2. --- Effects of TNF-R1 and -R2 on cell cycle related genes and proteins expression --- p.81 / Chapter 3.2.1. --- Effects of blocking TNF-R1/ -R2 on the time courses of cyclin D1 gene and protein expression --- p.81 / Chapter 3.2.2. --- Effect of blocking TNF-R1/ -R2 on the time course of cyclin D2 gene expression --- p.82 / Chapter 3.2.3. --- Effects of blocking TNF-R1/ -R2 on the time courses of cyclin D3 gene and protein expression --- p.85 / Chapter 3.2.4. --- Effects of blocking TNF-R1/ -R2 on the time courses of cdk-4 gene and protein expression --- p.90 / Chapter 3.2.5. --- Effects of blocking TNF-R1/ -R2 on the time courses of cyclin E gene and protein expression --- p.93 / Chapter 3.2.6. --- Effects of blocking TNF-R1/ -R2 on the time courses of cdk-2 gene and protein expression --- p.93 / Chapter 3.2.7. --- Effects of blocking TNF-R1/ -R2 on the time courses of p15 gene and protein expression --- p.96 / Chapter 3.2.8. --- Effects of blocking TNF-R1/ -R2 on the time courses of p27 gene and protein expression --- p.99 / Chapter 3.2.9. --- Effects of blocking TNF-R1/ -R2 on the time courses of p21 gene and protein expression --- p.103 / Chapter 3.2.10. --- Effects of blocking TNF-R1/ -R2 on the time courses of pl30 gene and protein expression --- p.106 / Chapter 3.2.11. --- Effect of blocking TNF-R1/ -R2 on the time course of Cak gene expression --- p.110 / Chapter 3.2.12. --- Effects of blocking TNP-R1/ -R2 on the time courses of cyclin H gene and protein expression --- p.110 / Chapter 3.2.13. --- Effects of blocking TNF-R1/ -R2 on the time courses of cyclin B gene and protein expression --- p.112 / Chapter 3.2.14. --- Effect of blocking TNF-R1/ -R2 on the time course of bcl-2 protein expression --- p.116 / Chapter 3.2.15. --- Effects of blocking TNF-R1/ -R2 on the time courses of bcl-xL gene and protein expression --- p.119 / Chapter 3.2.16. --- Effect of blocking TNF-R1/ -R2 on the time course of bcl-xα gene expression --- p.122 / Chapter 3.2.17. --- Effects of blocking TNF-R1/ -R2 on the time courses of bcl-w gene and protein expression --- p.124 / Chapter 3.2.18. --- Effect of blocking TNF-R1/ -R2 on the time course of Mcl-1 gene expression --- p.124 / Chapter 3.3. --- "Effects of other cytokines (IL-6, IL-lα, IL-lβ, IFγ) on cell cycle related genes and proteins expression" --- p.129 / Chapter 3.3.1. --- "Effects of TNF-α, IL-6, IL-lα, IL-lβ, IFγ on cyclin D1 gene and protein expression" --- p.129 / Chapter 3.3.2. --- "Effects of TNF-a, IL-6, IL-lα, IL-lβ, IFγ on cyclin D2 gene and protein expression" --- p.132 / Chapter 3.3.3. --- "Effects of TNF-α, IL-6, IL-lα, IL-1β, IFγ on cyclin D3 gene and protein expression" --- p.136 / Chapter 3.3.4. --- "Effects of TNF-α, IL-6, IL-lα, IL-1β, IFγ on cdk-4 gene and protein expression" --- p.140 / Chapter 3.3.5. --- "Effects of TNF-α, IL-6, IL-lα, IL-1β, IFγ on cyclin E gene and protein expression" --- p.144 / Chapter 3.3.6. --- "Effects of TNF-α, IL-6, IL-lα, IL-1β, IFγ on cdk-2 gene and protein expression" --- p.148 / Chapter 3.3.7. --- "Effects of TNF-α, IL-6, IL-lα, IL-1β, IFγ on pl5 gene and protein expression" --- p.152 / Chapter 3.3.8. --- "Effects of TNF-α, IL-6, IL-lα, IL-1β, IFγ on p27 gene and protein expression" --- p.152 / Chapter 3.3.9. --- "Effects of TNF-α, IL-6, IL-lα, IL-ip, IFγ on p21 gene and protein expression" --- p.159 / Chapter 3.3.10. --- "Effects of TNF-α, IL-6, IL-lα, IL-lβ, IFγ on pl30 gene and protein expression" --- p.162 / Chapter 3.3.11. --- "Effects of TNF-α, IL-6, IL-lα, IL-lp, IFγ on Cak gene expression" --- p.166 / Chapter 3.3.12. --- "Effects of TNF-α, IL-6, IL-lα, IL-1β, IFy on cyclin H gene and protein expression -" --- p.170 / Chapter 3.3.13. --- "Effects of TNF-α, IL-6, IL-lα, IL-1β, IFγ on cyclin B gene and protein expression" --- p.174 / Chapter 3.3.14. --- "Effects of TNF-α, IL-6, IL-lα, IL-1β, IFγ on bcl-2 gene and protein expression" --- p.178 / Chapter 3.3.15. --- "Effects of TNF-a, IL-6, IL-lα, IL-1β, IFγ on bcl-xL gene and protein expression" --- p.178 / Chapter 3.3.16. --- "Effects of TNF-α, IL-6, IL-lα, IL-1β, IFγ on bcl-xα gene expression" --- p.184 / Chapter 3.3.17. --- "Effects of TNF-α, IL-6, IL-lα, IL-lβ, IFγ on bcl-w gene and protein expression" --- p.187 / Chapter 3.3.18. --- "Effects of TNF-α, IL-6, IL-lα, IL-1β, IFγ on Mcl-1 gene expression" --- p.191 / Chapter 3.4. --- Effects of P-ARs on cell cycle related genes expression --- p.194 / Chapter 3.4.1. --- Effects of β-AR agonists and antagonists on cyclin D1 gene expression --- p.195 / Chapter 3.4.2. --- Effects of β-AR agonists and antagonists on cyclin D2 gene expression --- p.198 / Chapter 3.4.3. --- Effects of β-AR agonists and antagonists on cyclin D3 gene expression --- p.201 / Chapter 3.4.4. --- Effects of β-AR agonists and antagonists on cdk-4 gene expression --- p.204 / Chapter 3.4.5. --- Effects of β-AR agonists and antagonists on cyclin E gene expression --- p.207 / Chapter 3.4.6. --- Effects of β-AR agonists and antagonists on cdk-2 gene expression - --- p.210 / Chapter 3.4.7. --- Effects of β-AR agonists and antagonists on p15 gene expression --- p.213 / Chapter 3.4.8. --- Effects of β-AR agonists and antagonists on p27 gene expression --- p.216 / Chapter 3.4.9. --- Effects of β-AR agonists and antagonists on p21 gene expression --- p.219 / Chapter 3.4.10. --- Effects of β-AR agonists and antagonists on p130 gene expression --- p.222 / Chapter 3.4.11. --- Effects of β-AR agonists and antagonists on Cak gene expression --- p.225 / Chapter 3.4.12. --- Effects of β-AR agonists and antagonists on cyclin H gene expression --- p.228 / Chapter 3.4.13. --- Effects of β-AR agonists and antagonists on cyclin B gene expression --- p.231 / Chapter 3.4.14. --- Effects of β-AR agonists and antagonists on bcl-XL gene expression --- p.233 / Chapter 3.4.15. --- Effects of β-AR agonists and antagonists on bcl-xα gene expression --- p.236 / Chapter 3.4.16. --- Effects of β-AR agonists and antagonists on bcl-w gene expression --- p.239 / Chapter 3.4.17. --- Effects of β-AR agonists and antagonists on Mcl-1 gene expression --- p.243 / Chapter CHAPTER 4. --- DISCUSSION & CONCLUSION --- p.247 / Chapter 4.1. --- Effects of TNF-α on the induction of cell cycle regulatory genes/proteins expression --- p.248 / Chapter 4.2. --- Effects of TNF-α on bcl-2 family apoptotic inhibitor genes expression --- p.250 / Chapter 4.3. --- The TNF-R subtype(s) responsible for the TNF-a-induced cell cycle regulatory genes and proteins expression --- p.251 / Chapter 4.4. --- Is the TNF-α-induced cell cycle regulatory genes and proteins expression cytokine specific? --- p.253 / Chapter 4.5. --- The relationship between TNF-α and β-adrenergic mechanism in C6 cell proliferation --- p.254 / Chapter 4.6. --- General Discussion --- p.256 / Chapter 4.7. --- Possible treatments for brain injury --- p.258 / APPENDIX --- p.259 / REFERENCES --- p.348

Amyotrophic lateral sclerosis (ALS) is a late onset neurodegenerative disorder characterised by selective loss of upper and lower motor neurons (MNs). Recently, the GGGGCC (G4C2) hexanucleotide repeat expansion in chromosome 9 open reading frame 72 (C9orf72) has been identified as the most common genetic cause of ALS, highlighting the importance of studying the pathogenic mechanisms underlying this mutation. Accumulating evidence implicates that ALS is a multisystem and multifactor disease. Specifically, non-neuronal cells, astrocytes in particular, are also affected by toxicity mediated by ALS-related mutations, and they can contribute to neurodegeneration, suggesting astrocytes as a key player in ALS pathogenesis. Here, a human induced pluripotent stem cells (iPSCs)-based in vitro model of ALS was established to investigate the impact of the C9orf72 mutation on astrocyte behaviour—both cell- and non-cell autonomous. Work in this study shows that patient iPSC-derived astrocytes recapitulate key pathological features associated with C9orf72-mediated ALS, such as formation of G4C2 repeat RNA foci, production of dipeptide repeat (DPR) proteins and reduced viability under basal conditions compared to controls. Moreover, C9orf72 mutant astrocytes in co-culture result in reduced viability and structural defects of human MNs. Importantly, correction of the G4C2 repeat expansion in mutant astrocytes through targeted gene editing reverses these phenotypes, strongly confirming that the C9orf72 mutation is responsible for the observed findings. Altogether, this iPSC-based in vitro model provides a valuable platform to gain better understandings of ALS pathophysiology and can be used for future exploration of potential therapeutic drugs.

Homeostasis within the neuro-glial unit is essential to the longevity of neurons. Conversely, loss of homeostasis, particularly of Ca2+ levels, of redox balance and of ATP, contribute to neuronal loss and dysfunction in many neurodegenerative and neurological disorders. This thesis is centred on better understanding the vulnerability of neurons to stress, as well as adaptive responses to these stresses. Since neurodegenerative conditions associated with Ca2+, redox and bioenergetic dyshomeostasis are often characterised by early dendritic pathology, I first studied dendritic vs. somatic responses of primary cortical neurons to these types of challenges in real-time. Using a wide range of genetically-encoded probes to measure Ca2+, ATP, NADH, glutathione and glutamate, I show that dendrites are selectively vulnerable to oxidative stress, excitotoxicity as well as to metabolic demand induced by action potential (AP) burst activity. However, I provide evidence that neurons undergoing energetically demanding AP burst activity can adjust their metabolic output by increasing mitochondrial NADH production in a manner dependent on the mitochondrial calcium uniporter (MCU), as well as increase their capacity to buffer their intracellular redox balance. Finally, I have studied transcriptional programs in astrocytes triggered by neurons and neuronal activity to better understand adaptive signaling between different cell types in the neuro-glial unit. I developed a novel system combining neurons and astrocytes from closely-related species, followed by RNA-seq and in silico read sorting. I uncovered a program of neuron-induced astrocytic gene expression which drives and maintains astrocytic maturity and neurotransmitter uptake function. In addition I identified a novel form of synapse-to-nucleus signaling, mediated by glutamatergic activity and acutely regulating diverse astrocytic genes involved in astrocyte-neuron metabolic coupling. Of note, neuronal activity co-ordinately induced astrocytic genes involved in astrocyte-to-neuron thyroid hormone signaling, extracellular antioxidant defences, and the astrocyte-neuron lactate shuttle, suggesting that this non cell-autonomous signaling may form part of the homeostatic machinery within the neuro-glial unit.