O Fator de Necrose Tumoral-alfa (TNF-alfa) possui um importante papel na imunopatogênese da psoríase e agentes biológicos, como os inibidores de TNF-alfa, têm apresentado bons resultados no tratamento desta. No entanto, estes agentes foram associados ao aumento de casos de reativação de tuberculose entre os pacientes que os utilizaram. Este estudo foi realizado com o intuito de avaliar a resposta imune de pacientes com psoríase grave, ativa, sem tratamento, frente a antígenos de Mycobacterium tuberculosis (Mtb), e o efeito dos inibidores de TNF-alfa nesta resposta. Estudamos 24 pacientes com psoríase grave divididos em 2 grupos: não reatores (n = 14) e reatores (n = 10) ao teste intradérmico com PPD. Como controle, utilizamos um total de 26 indivíduos sadios, também separados em 2 grupos segundo a reatividade ao PPD (PPD-, n = 13; PPD+, n = 13). Em uma segunda etapa estudamos 11 pacientes com psoríase leve a moderada, também sem tratamento, PPD (-) para avaliarmos a importância da gravidade da psoríase na resposta aos antígenos micobacterianos. Avaliamos a resposta imunológica in vitro através da linfoproliferação, quantificação da produção de IFN-gama (ELISA) e quantificação de células produtoras de IFN-gama (ELISPOT), na presença e ausência dos inibidores de TNF-alfa (infliximab e etanercepte), utilizando os antígenos purificados ESAT-6, Ag85B e o antígeno bruto sonicado da cepa H37Rv (AgSMtb), e o mitógeno fitohemaglutinina (PHA). Os pacientes com psoríase grave PPD (-) apresentaram reposta linfoproliferativa e níveis de IFN-gama menores que nos controles PPD (-). Os pacientes com psoríase leve a moderada apresentaram resposta imune intermediária entre controles e pacientes graves. Em relação aos inibidores de TNF- alfa, verificou-se que infliximab e etanercepte apresentaram diferença em suas capacidades de inibição, sendo que somente o infliximab ocasionou a inibição total de TNF-alfa. Em contrapartida o etanercept manteve a produção de TNF-alfa, e em alguns casos elevou sua produção. Estes diminuíram apenas parcialmente a reatividade in vitro dos pacientes com psoríase, uma vez que a secreção de IFN-gama e o número de células produtoras de IFN-gama não foram alterados na presença dos inibidores. A secreção de IL-10 foi diminuída tanto na presença do infliximab, quanto na presença do etanercepte. Os dados obtidos permitem concluir que (a) os pacientes com psoríase grave PPD (-) apresentam uma baixa reatividade in vitro, principalmente das respostas que avaliam linfócitos T de memória central, aos antígenos de Mtb, sendo que essa baixa reatividade não está totalmente relacionada com a gravidade da doença, uma vez que os pacientes com psoríase leve a moderada apresentaram resposta intermediária a dos controles e pacientes com psoríase grave; (b) e que apesar dos inibidores de TNF- alfa promoverem uma inibição parcial da resposta imune, a reativação da tuberculose estaria mais relacionada à própria ausência de TNF-alfa, não compensada pela atuação isolada, e provavelmente insuficiente, de IFN-gama na manutenção do granuloma, do que a outras substanciais modificações na resposta imunológica frente aos antígenos micobacterianos. / Tumor necrosis factor alpha (TNF-alpha) has a pivotal role in psoriasis pathogenesis and biologic agents, such as TNF-alpha inhibitors, have provided good results in its treatment. However, the use of these agents has been associated with an increase in the number of cases of tuberculosis reactivation. This study aimed to evaluate the immune response of severe psoriasis patients, with active, untreated disease to relevant Mycobcterium tuberculosis antigens, and the effect of the TNF-alpha inhibitors (infliximab and etanercept) in this response. Twenty four severe psoriasis patients were enrolled and divided in two groups according to their reactivity to the tuberculin skin test: TST (n= 14) and TST + (n=10). As controls, we studied 26 healthy donors, also divided in two groups to the TST reactivity (TST -, n=13; TST+, n=13). Eleven mild to moderate psoriasis patients, untreated, TST (-) were studied to evaluated the role of psoriasis severity in the immune response to the mycobacterial antigens. Immune responses were evaluated in vitro by the lymphocyte proliferative response (LPR) assay, ELISA for IFN-? secretion by peripheral blood mononuclear cells and enumeration of IFN-? secreted cells (ELISPOT) induced in response to the purified antigens ESAT-6, Ag85B and a crude sonicated antigen preparation from H37Rv Mtb strain (AgSMtb), as well as to the mitogen phytohemagglutinin (PHA), in the presence or absenceinflimab/etanercept. The LPR and IFN-g secretion to Mtb antigens were lower in TST- severe psoriasis patients than TST- controls. Mild to moderate psoriasis patients had intermediate responses, between controls and severe psoriasis patients. The TNF-a inhibitors infliximab and etanercept showed differences in their inhibitiory activity, since only infliximab was capable to neutralize all TNF-a. On the other hand, etanercept kept TNF-alpha production, and in some cases even increased its production. The TNF-alpha inhibitors diminished partially the in vitro patients immune responses, since the IFN-? secretion and enumeration of IFN-? secreted cells were not affected. IL-10 secretion was diminished with both TNF-a inhibitors. In conclusion: (a) TST(-) severe psoriasis patients have decreased in vitro reactivity, mainly in those responses that evaluate central memory T-cell responses, to Mtb antigens, and this decrease could not be fully explained by disease severity, since mild psotiasis patients had intermediate responses; (b) and despite the fact that TNF-alpha inhibitors promote a partial immune response inhibition, tuberculosis reactivation could be related more with the lack of TNF-alpha, which was probably not compensated by the IFN-g activity alone, probably insufficient, to the support granuloma formation, than other defects of the immune response to Mtb antigens.

by Wai Yuen. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves 123-157). / Abstracts in English and Chinese. / Acknowledegment --- p.iv / Abstract --- p.v / List of Abbreviations --- p.ix / Chapter CHAPTER ONE: --- INTRODUCTION / Chapter 1.1 --- Parkinson's Disease (PD) --- p.1 / Chapter 1.1.1 --- Epidemiology --- p.1 / Chapter 1.1.2 --- Neuropathology --- p.2 / Chapter 1.1.3 --- Clinical Symptoms --- p.3 / Chapter 1.1.4 --- Treatment --- p.6 / Chapter 1.2 --- Proposed Mechanisms of Neurodegeneration in PD --- p.11 / Chapter 1.2.1 --- Oxidative Stress --- p.11 / Chapter 1.2.2 --- Mitochondrial Dysfunction --- p.13 / Chapter 1.2.3 --- Genetic Factors --- p.15 / Chapter 1.2.4 --- Environmental Factors --- p.17 / Chapter 1.2.5 --- Ageing --- p.20 / Chapter 1.3 --- "1-Methy-4-Phenyl-1,2,3,6-Tetrahydropyridine (MPTP) as a PD Model" --- p.22 / Chapter 1.3.1 --- Discovery of MPTP --- p.22 / Chapter 1.3.2 --- The Mechanisms of MPTP-induced Neurotoxicity --- p.23 / Chapter 1.4 --- Antioxidants in the Central Nervous System --- p.26 / Chapter 1.4.1 --- Superoxide Dismutase --- p.26 / Chapter 1.4.2 --- Glutathione --- p.27 / Chapter 1.5 --- Metallothioneins (MTs) --- p.29 / Chapter 1.5.1 --- Characteristics of MTs --- p.29 / Chapter 1.5.2 --- Functions of Astrocytes --- p.31 / Chapter 1.6 --- Astrocytes --- p.34 / Chapter 1.6.1 --- Characteristics of Astrocytes --- p.34 / Chapter 1.6.2 --- Functions of Astrocytes --- p.35 / Chapter 1.6.3 --- Role of Astrocytes in Parkinson's Disease --- p.39 / Chapter 1.7 --- Aim of Project --- p.41 / Chapter CHAPTER TWO: --- MATERIALS AND METHODS / Chapter 2.1 --- In Vitro Study --- p.44 / Chapter 2.1.1 --- Astrocyte Cultures --- p.44 / Chapter 2.1.2 --- Treatment Regimen --- p.46 / Chapter 2.1.2.1 --- 1 -methyl-4-phenyl-pyridinium (MPP+) Treatment --- p.46 / Chapter 2.1.2.2 --- Induction of Metallothioneins (MTs) and Glutathione (GSH) --- p.46 / Chapter 2.1.2.2.1 --- Northern Blot Analysis --- p.47 / Chapter 2.1.2.2.2 --- Immunocytochemical Staining for MTs --- p.48 / Chapter 2.1.2.2.3 --- GSH Assay --- p.49 / Chapter 2.1.2.3 --- Iron Chelation --- p.51 / Chapter 2.1.2.4 --- Combined Pretreatment --- p.51 / Chapter 2.1.3 --- Lactate Dehydrogenase (LDH) Assay --- p.51 / Chapter 2.1.4 --- "3,(4,5-dimethylthiazol-2-yl)2,5-diphenyl-tetrazolium bromide (MTT) Assay" --- p.53 / Chapter 2.1.5 --- Reactive Oxygen Species (ROS) Assay --- p.55 / Chapter 2.1.6 --- Protein Assay --- p.56 / Chapter 2.1.7 --- Statistics --- p.57 / Chapter 2.2 --- In Vivo Study --- p.57 / Chapter 2.2.1 --- "Administration of 1 -methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)" --- p.57 / Chapter 2.2.2 --- Tyrosine Hydroxylase (TH) Immunocytochemical Staining --- p.58 / Chapter 2.2.3 --- DAT Receptor Binding Assay --- p.59 / Chapter 2.2.4 --- Dopamine (DA) and DA metabolites - High Performance Liquid Chromatography (HPLC) --- p.60 / Chapter 2.2.5 --- Statistics --- p.61 / Chapter CHAPTER THREE: --- RESULTS / Chapter 3.1 --- In Vitro Study --- p.62 / Chapter 3.1.1. --- Induction of Metallothioneins (MTs) in Astrocytes with Zinc Sulfate (ZnS04) --- p.62 / Chapter 3.1.1.1 --- Immunocytochemical changes --- p.62 / Chapter 3.1.1.2 --- Northern Blot Analysis --- p.62 / Chapter 3.1.1.3 --- The Effects of ZnSO4 Pretreatment on 1 -methyl-4-phenyl- pyridinium (MPP+)-treated Astrocytes --- p.63 / Chapter 3.1.1.3.1 --- Lactate Dehydrogenase (LDH) Activities --- p.63 / Chapter 3.1.1.3.2 --- "3,(4,5-dimethylthiazol-2-yl)2,5-diphenyl- tetrazolium bromide (MTT) Activities" --- p.67 / Chapter 3.1.1.3.3 --- Reactive Oxygen Species (ROS) Production --- p.71 / Chapter 3.1.2 --- The Effects of NAc Pretreatment on MPP+-treated Astrocytes --- p.75 / Chapter 3.1.2.1 --- Glutathione (GSH) levels --- p.75 / Chapter 3.1.2.2 --- LDH Activities --- p.77 / Chapter 3.1.2.3 --- MTT Activities --- p.80 / Chapter 3.1.2.4 --- ROS Production --- p.83 / Chapter 3.1.3 --- The Effects of Deferoxamine on MPP+-treated Astrocytes --- p.87 / Chapter 3.1.3.1 --- LDH Activities --- p.87 / Chapter 3.1.3.2 --- ROS Production --- p.89 / Chapter 3.1.4 --- The Effects of ZnSO4 and NAc Combined Treatment on MPP+-treated Astrocytes --- p.92 / Chapter 3.1.4.1 --- LDH Activities --- p.92 / Chapter 3.1.4.2 --- ROS Production --- p.95 / Chapter 3.2 --- "Effects of 1 -methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) on MT-I, -II Knock-out Mice" --- p.99 / Chapter 3.2.1 --- The Effects of MPTP on Substantia Nigral (SN) Cell Loss --- p.99 / Chapter 3.2.2 --- The Effects of MPTP on Striatal (ST) and SN Dopamine Transporter (DAT) Binding --- p.99 / Chapter 3.2.3 --- The Effects of MPTP on ST Dopamine (DA) Metabolites --- p.100 / Chapter CHAPTER FOUR: --- DISCUSSION AND CONCLUSION --- p.102 / REFERENCES --- p.123

Tang Angie. / Thesis submitted in: November 2005. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 151-172). / Abstracts in English and Chinese. / Acknowledgements --- p.i / Abstract --- p.iii / Abstract in Chinese --- p.vi / Table of Contents --- p.vii / List of Publications --- p.xi / Awards --- p.xii / List of Abbreviations --- p.xiii / List of Tables --- p.xv / List of Figures --- p.xvi / Chapter Chapter 1 --- Introduction --- p.1 / Chapter Chapter 2 --- Literature Review --- p.3 / Chapter 2.1 --- Gastric cancer-overview --- p.3 / Chapter 2.1.1 --- Epidemology --- p.3 / Chapter 2.1.2 --- Pathology --- p.3 / Chapter 2.1.3 --- Etiologies and Risk Factors --- p.4 / Chapter I. --- Environmental factors --- p.4 / Chapter a. --- Helicobacter pylori infections --- p.4 / Chapter b. --- Epstein-Barr virus (EBV) --- p.6 / Chapter c. --- Dietary factors --- p.6 / Chapter d. --- Smoking --- p.6 / Chapter II. --- Genetic Factors --- p.7 / Chapter a. --- Hereditary Gastric Cancer --- p.7 / Chapter b. --- Genetic polymorphism --- p.8 / Chapter III. --- Cyclooxygenases (COX) enzymes --- p.10 / Chapter IV. --- Molecular carcinogenesis --- p.11 / Chapter a. --- Activation of proto-oncogenes --- p.11 / Chapter b. --- Candidate tumor suppressor genes --- p.12 / Chapter 1. --- Gene mutation and deletion --- p.12 / Chapter 2. --- Epigenetic Silencing --- p.13 / Chapter 2.2 --- Epigenetics --- p.14 / Chapter 2.2.1 --- DNA methylation --- p.15 / Chapter 2.2.2 --- Histone modification --- p.28 / Chapter I. --- Histone acetylation and deacetylation --- p.32 / Chapter II. --- Histone methylation --- p.32 / Chapter III. --- Histone phosphorylation --- p.34 / Chapter IV. --- Histone ubiquitylation --- p.34 / Chapter 2.3 --- "HAT, HDAC and HDAC inhibitors" --- p.36 / Chapter 2.3.1 --- HAT --- p.38 / Chapter 2.3.2 --- HDAC --- p.39 / Chapter (a) --- Class I --- p.40 / Chapter (b) --- Class II --- p.41 / Chapter (c) --- Class III --- p.42 / Chapter (d) --- Mammalian HDAC and their mechanism of deacetylation --- p.44 / Chapter 2.3.3 --- HDAC inhibitors --- p.45 / Chapter I. --- Class I/II natural inhibitors --- p.47 / Chapter II. --- Class I/II synthetic inhibitors --- p.48 / Chapter III. --- Sirtuins inhibitors --- p.49 / Chapter IV. --- Activity of HDAC inhibitors in vitro --- p.50 / Chapter a. --- Effect in the gene expression --- p.50 / Chapter b. --- Non-transcriptional effects --- p.55 / Chapter c. --- Activity of HDAC inhibitors with other agents --- p.57 / Chapter d. --- Effects in xenograft tumor models --- p.57 / Chapter V. --- Clinical trials of HDAC inhibitors --- p.59 / Chapter Chapter 3 --- Aims of the study --- p.63 / Chapter Chapter 4 --- Materials and Methods --- p.64 / Chapter 4.1 --- Cell culture --- p.64 / Chapter 4.2 --- Drug treatment --- p.64 / Chapter 4.2.1 --- Suberoylanilide Hydroxamic Acid treatment --- p.64 / Chapter 4.2.2 --- Trichostatin A treatment --- p.65 / Chapter 4.3 --- Cell proliferation assay --- p.66 / Chapter 4.4 --- Apoptotic assay --- p.67 / Chapter 4.5 --- Flow cytometry --- p.67 / Chapter 4.5.1 --- Cell preparation --- p.67 / Chapter 4.5.2 --- Propidium Iodide staining --- p.68 / Chapter 4.5.3 --- Annexin V-FITC staining --- p.68 / Chapter 4.5.4 --- Flow cytometer analysis --- p.69 / Chapter 4.6 --- Total RNA extraction --- p.70 / Chapter 4.7 --- DNA extraction --- p.71 / Chapter 4.8 --- Protein extraction --- p.72 / Chapter 4.9 --- Western blottng --- p.72 / Chapter 4.10 --- Microarray analysis --- p.74 / Chapter 4.10.1 --- Sample preparation for microarray --- p.74 / Chapter 4.10.2 --- Hybridization --- p.75 / Chapter 4.10.3 --- Scanning and data processing --- p.75 / Chapter 4.10.4 --- Data analysis --- p.76 / Chapter 4.11 --- Primer design --- p.77 / Chapter 4.12 --- RT-PCR --- p.77 / Chapter 4.12.1 --- Reverse transcription --- p.77 / Chapter 4.12.2 --- Quantitative RT-PCR --- p.78 / Chapter 4.13 --- Methlyation study --- p.79 / Chapter 4.13.1 --- Demethylation by 5-aza-2'deoxycytidine --- p.79 / Chapter 4.13.2 --- Bisulfite modification --- p.79 / Chapter 4.13.3 --- Methylation-specific PCR (MSP) --- p.79 / Chapter Chapter 5 --- Results --- p.81 / Chapter 5.1 --- Morphological changes in AGS cells --- p.81 / Chapter 5.2 --- Anti-cancer effects of HDAC inhibitors --- p.81 / Chapter 5.2.1 --- Effect of HDAC inhibitors on cell growth --- p.81 / Chapter a. --- SAHA inhibits cell proliferation --- p.82 / Chapter b. --- TSA inhibits cell proliferation --- p.82 / Chapter 5.2.2 --- Cell cycle analysis --- p.87 / Chapter a. --- Effect of SAHA on cell cycle --- p.87 / Chapter b. --- Effect of TSA on cell cycle --- p.88 / Chapter 5.2.3 --- Induction of apoptosis on AGS cells --- p.92 / Chapter a. --- SAHA induces apoptotic cell death --- p.92 / Chapter b. --- TSA induces apoptotic cell death --- p.94 / Chapter 5.3 --- Induction of histone expression on AGS cells --- p.102 / Chapter 5.3.1 --- HDAC inhibitors induced acetylation of histone H3 --- p.102 / Chapter 5.3.2 --- HDAC inhibitors induced acetylation of histone H4 --- p.103 / Chapter 5.4 --- SAHA- and TSA-induced gene expression profiles --- p.106 / Chapter 5.5 --- Verification of gene expression by quantitative RT-PCR --- p.108 / Chapter 5.6 --- Methylation study --- p.113 / Chapter Chapter 6 --- Discussion --- p.116 / Chapter 6.1 --- Improved treatment strategy is needed for gastric cancer. --- p.116 / Chapter 6.2 --- HDAC inhibitors as potential anti-cancer agents --- p.117 / Chapter 6.3 --- Potential anti-cancer effect of TSA and SAHA on AGS cells --- p.120 / Chapter I. --- Morphological changes of AGS gastric cancer cells --- p.120 / Chapter II. --- Inhibition of cell proliferation --- p.120 / Chapter III. --- Induction of cell cycle arrest --- p.121 / Chapter IV. --- Induction of apoptosis --- p.122 / Chapter 6.4 --- Expression of acetylated histones upon treatment with TSA and SAHA --- p.124 / Chapter 6.5 --- Identify potential target genes upon treatment with TSA and SAHA --- p.125 / Chapter 6.5.1 --- Candidate genes involved in cell cycle --- p.126 / Chapter a. --- P21WAF1 --- p.126 / Chapter b. --- p27kip1. --- p.128 / Chapter c. --- Cyclin E & Cyclin A --- p.128 / Chapter d. --- Signal-induced proliferation-associated gene 1 (SIPA1) .… --- p.129 / Chapter 6.5.2 --- Candidate genes involved in apoptosis and anti-proliferation --- p.130 / Chapter a. --- BCL2-interacting killer (apoptosis-inducing) (BIK) (Pro-apoptotic gene) --- p.131 / Chapter b. --- Thioredoxin interacting protein (TXNIP) (Proapoptotic gene) / Chapter c. --- Cell death-inducing DFFA-like effector b (CIDEB) (apoptosis induction) --- p.132 / Chapter d. --- B-cell translocation gene 1 (BTG1) - (anti-proliferation) --- p.133 / Chapter e. --- Quiescin 6 (QSCN6) (anti-proliferation) --- p.133 / Chapter f. --- "Cysteine-rich, angiogenic inducer, 61 (CYR61) (anti-proliferative)" --- p.134 / Chapter g. --- Metallothionein 2A (MT2A) (apoptosis induction and anti-proliferative) --- p.134 / Chapter 6.5.3 --- Other genes reported to be up-regulated with HDAC inhibitors treatment --- p.135 / Chapter a. --- Glia maturation factor-gamma (GMFG) --- p.135 / Chapter b. --- v-fos FBJ murine osteosarcoma viral oncogene homolog (FOS) / Chapter c. --- Interleukin 8 (IL-8) --- p.136 / Chapter d. --- Insulin-like growth factor binding protein- 2 (IGFBP2) --- p.137 / Chapter e. --- Integrin alpha chain 7 (ITGA7) --- p.138 / Chapter 6.5.4 --- Selected highly up-regulated genes with HDAC inhibitors treatment --- p.139 / Chapter a. --- Aldo-keto reductase family 1，member C3 (AKR1C3) --- p.139 / Chapter b. --- GPI-anchored metastasis-associated protein homolog (C4.4A) --- p.139 / Chapter c. --- "Serine (or cysteine) proteinase inhibitor，clade I (neuroserpin), member 1 (SERPINI1)" --- p.140 / Chapter d. --- "Serine (or cysteine) proteinase inhibitor，clade E (nexin, plasminogen activator inhibitor type 1), member 1 (SERPINE1)" --- p.140 / Chapter e. --- Adrenomedullin (ADM) --- p.141 / Chapter f. --- Dehydrogenase/reductase (SDR family) member 2 (HEP27) --- p.142 / Chapter g. --- Cholecystokinin (CCK) --- p.142 / Chapter h. --- Silver homolog (mouse) (SILV) --- p.143 / Chapter 6.6 --- Genes regulated by gene promoter hypermethylation in AGS cells --- p.143 / Chapter Chapter 7 --- Conclusion --- p.147 / Chapter Chapter 8 --- Further Studies --- p.150 / References --- p.151 / Appendix I --- p.151 / Appendix II --- p.III / Appendix III --- p.IV / Appendix IV --- p.VI

病原體感染是包括植物的高等生物的主要健康危害之一。為抵禦入侵者，大多數植物會製造防禦蛋白，包括凝集素、蛋白酶抑製劑、抗真菌蛋白、核糖核酸酶和核糖體失活蛋白，並分佈在不同的器官，如葉、根、種子和塊莖。一些植物防禦蛋白被發現能表現出多種生物活性，如抗腫瘤活性、抗細菌活性和抗病毒活性，能抵抗多種植物病原菌和人類病原體。因此，一些植物防禦蛋白可能有潛力用於治療人類疾病，或保護農作物免受感染。 / 我們在研究中從不同的植物來源成功純化出各種防禦蛋白，包括：小芋頭塊莖中的血凝素、日本長芋中的凝集素、東北紅豆中的血凝素和抗真菌多肽、棕色芸豆中的凝集素、抗真菌多肽和胰蛋白酶抑製劑，玉豆一號中的凝集素以及小斑豆中的胰蛋白酶抑製劑。小芋頭血凝素被發現能誘導脾細胞的有絲分裂反應。日本長芋凝集素和東北紅豆血凝素被發現能對一些腫瘤細胞株（如乳腺癌MCF7細胞及鼻咽癌CNE2細胞）發揮抗增殖的作用。棕色芸豆凝集素能誘導脾臟細胞的有絲分裂反應以及抑制腫瘤細胞株（如乳腺癌MCF7細胞、肝癌HepG2及鼻咽癌CNE1和 CNE2細胞）的生長，而棕色芸豆抗真菌蛋白能抑制數種病原真菌物種的生長。研究這些防禦蛋白的生物活性有助找出其潛在應用價值，如藥用前景。 / Infection from pathogens is one of the major health hazards in higher organisms including plants. To defend against harmful invaders, most plants produce a variety of defense proteins including lectins, protease inhibitors, antifungal proteins, ribonucleases and ribosome-inactivating proteins. They may be present in different organs of the plants, such as leaves, roots, seeds and tubers. Some of the plant defense proteins were found to exhibit a variety of biological activities such as anti-tumor activity, anti-bacterial activity and anti-viral activity that act against various plant pathogens and also some human pathogens. Therefore, some plant defense proteins may have potential for therapeutic applications in human diseases, or protecting the crops from infections. / This study involved purification of defense proteins from different plant sources. The proteins that were successfully isolated included a hemagglutinin from small taro tubers, a lectin from Japanese yam tubers, a lectin and an antifungal peptide from northeast red beans, a lectin, an antifungal peptide and a trypsin inhibitor from brown kidney beans, a lectin from French bean cultivar no. 1 and a trypsin inhibitor from mini pinto beans. The small taro hemagglutinin was found to induce mitogenic response in splenocytes. The Japanese yam lectin and northeast red bean hemagglutinin were found to exert anti-proliferative activity toward some tumor cell lines including MCF7 and CNE2 cells. The brown kidney bean lectin induced a mitogenic response from murine splenocytes as well as inhibited the growth of tumor cell lines including MCF7, HepG2, CNE1 and CNE2 cells, while the brown kidney bean antifungal protein inhibited the growth of several pathogenic fungal species including M. arachidicola, S. turcica and B. maydis. Studying the biological activities of these defense proteins helps to find out their potential applications like therapeutic uses. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Chan, Yau Sang. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves i-xvii). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese. / Abstract --- p.i-ii / 論文摘要 --- p.iii / Acknowledgements --- p.iv / List of Publications --- p.v / Table of Contents --- p.vi-vii / List of Figures --- p.viii-ix / List of Tables --- p.x / List of Abbreviations --- p.xi / Chapter Chapter 1 --- Introduction on plant defense proteins / Chapter 1.1 --- General introduction to plant defense proteins --- p.1-2 / Chapter 1.2 --- An overview on lectins --- p.3-18 / Chapter 1.2.1 --- History of lectins --- p.3-6 / Chapter 1.2.2 --- Classification of lectins --- p.7-11 / Chapter 1.2.3 --- Biological activities of lectins --- p.12-16 / Chapter 1.2.4 --- Applications of plant lectins --- p.16-18 / Chapter 1.3 --- An overview on defensins --- p.18-25 / Chapter 1.3.1 --- Types of defensins --- p.18-21 / Chapter 1.3.2 --- Mechanism of anti-microbial activity of defensins --- p.22-23 / Chapter 1.3.3 --- Application of defensins --- p.23-25 / Chapter 1.4 --- An overview on trypsin inhibitors --- p.25-38 / Chapter 1.4.1 --- Serpins --- p.26-28 / Chapter 1.4.2 --- Kunitz-type protease inhibitors --- p.29-31 / Chapter 1.4.3 --- Bowman-Birk protease inhibitors --- p.32-34 / Chapter 1.4.4 --- Physiological functions of protease inhibitors --- p.35-38 / Chapter 1.5 --- Aim of study --- p.38-41 / Chapter Chapter 2 --- Isolation and characterization of a hemagglutinin from small taros and a lectin from yam tubers / Chapter 2.1 --- Introduction --- p.42-45 / Chapter 2.2 --- Materials and Methods --- p.46-55 / Chapter 2.3 --- Results --- p.56-78 / Chapter 2.4 --- Discussion --- p.79-84 / Chapter Chapter 3 --- Isolation and characterization of two defense proteins from seeds of Phaseolus vulgaris cv. “northeast red bean“ / Chapter 3.1 --- Introduction --- p.85-86 / Chapter 3.2 --- Materials and Methods --- p.87-93 / Chapter 3.3 --- Results --- p.93-119 / Chapter 3.4 --- Discussion --- p.120-129 / Chapter Chapter 4 --- Isolation and characterization of three defense proteins from seeds of Phaseolus vulgaris cv. “brown kidney bean“ / Chapter 4.1 --- Introduction --- p.130-131 / Chapter 4.2 --- Materials and Methods --- p.131-136 / Chapter 4.3 --- Results --- p.136-175 / Chapter 4.4 --- Discussion --- p.176-189 / Chapter Chapter 5 --- Isolation and characterization of a lectin from French bean cultivar no. 1 beans and a trypsin inhibitor from mini pinto beans / Chapter 5.1 --- Introduction --- p.190-191 / Chapter 5.2 --- Materials and Methods --- p.191-194 / Chapter 5.3 --- Results --- p.195-212 / Chapter 5.4 --- Discussion --- p.213-221 / Chapter Chapter 6 --- General discussion / Chapter 6.1 --- Summary on purification protocols of the defense proteins in the study --- p.222-228 / Chapter 6.2 --- Chemical properties of the defense proteins in the study --- p.228-232 / Chapter 6.3 --- Biological activities of the defense proteins in the study --- p.232-238 / Chapter 6.4 --- Potential application of these defense proteins and future perspectives --- p.238-242 / References --- p.i-xvi

Wong Hei Lui. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 192-226). / Abstracts in English and Chinese. / Publications Based On The Work In This Thesis --- p.i / Abstract --- p.ii / Acknowledgements --- p.vii / Abbreviations --- p.viii / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Normal joint --- p.1 / Chapter 1.11 --- Biology of joint --- p.1 / Chapter 1.12 --- Structure of synovial joint --- p.1 / Chapter 1.13 --- Components of the mature synovial joint --- p.3 / Chapter 1.131 --- Articular cartilage --- p.3 / Chapter 1.1311 --- Water --- p.4 / Chapter 1.1312 --- Cartilage matrix --- p.4 / Chapter 1.1313 --- Chondrocyte --- p.5 / Chapter 1.132 --- Synovium --- p.5 / Chapter 1.1321 --- Synovium vasculature --- p.6 / Chapter 1.1322 --- Synovial blood flow --- p.7 / Chapter 1.133 --- Synovial fluid --- p.8 / Chapter 1.134 --- Bone --- p.9 / Chapter 1.2 --- Pathological processes of arthritis --- p.11 / Chapter 1.21 --- Activation of immune cells in arthritis --- p.11 / Chapter 1.22 --- Synovial proliferation --- p.13 / Chapter 1.221 --- Synovial lining cell activation --- p.13 / Chapter 1.222 --- Pannus invasion --- p.14 / Chapter 1.23 --- Cartilage and bone degradation --- p.14 / Chapter 1.231 --- Depletion of proteoglycan (GAG) --- p.15 / Chapter 1.232 --- Collagen denature --- p.15 / Chapter 1.3 --- Tachykinins (TKs) --- p.17 / Chapter 1.31 --- History --- p.17 / Chapter 1.32 --- "Synthesis, storage and release of TKs" --- p.17 / Chapter 1.33 --- Tachykinin receptors --- p.18 / Chapter 1.331 --- Characterization of NK1 receptor --- p.19 / Chapter 1.332 --- Characterization of NK2 receptor --- p.19 / Chapter 1.333 --- Characterization of NK3 receptor --- p.20 / Chapter 1.34 --- Effector systems of TKs --- p.21 / Chapter 1.35 --- Termination of TK signals --- p.21 / Chapter 1.351 --- Enzymatic breakdown --- p.21 / Chapter 1.352 --- Receptor desensitization --- p.22 / Chapter 1.353 --- Receptor endocytosis --- p.22 / Chapter 1.36 --- TK receptor antagonists --- p.23 / Chapter 1.361 --- Selective NK1 receptor antagonists --- p.23 / Chapter 1.362 --- Selective NK2 receptor antagonists --- p.24 / Chapter 1.363 --- Selective NK3 receptor antagonists --- p.25 / Chapter 1.4 --- Roles of tachykinins in arthritis --- p.28 / Chapter 1.41 --- Correlation between tachykinins and joint inflammation --- p.28 / Chapter 1.42 --- Roles of tachykinins in immune cell activation --- p.30 / Chapter 1.43 --- Roles of tachykinins in synovial proliferation --- p.31 / Chapter 1.44 --- Roles of tachykinins in cartilage degradation --- p.32 / Chapter 1.5 --- Animal model of arthritis --- p.33 / Chapter 1.51 --- Instability model --- p.33 / Chapter 1.52 --- Immobilization model --- p.34 / Chapter 1.53 --- Noxious agent-induced model --- p.34 / Chapter 1.531 --- Collagen-induced erosive arthritis --- p.34 / Chapter 1.532 --- Cartilage oligometric matrix protein-induced arthritis --- p.35 / Chapter 1.533 --- Oil-induced arthritis --- p.35 / Chapter 1.534 --- Streptococcal cell wall-induced arthritis --- p.35 / Chapter 1.535 --- Adjuvant-induced arthritis --- p.36 / Chapter 1.536 --- Pristane-induced arthritis --- p.36 / Chapter 1.6 --- Current anti-arthritic therapies --- p.39 / Chapter 1.61 --- Non steroid anti-inflammatory drugs --- p.39 / Chapter 1.62 --- Glucocorticoid --- p.44 / Chapter 1.63 --- Second-line treatment --- p.46 / Chapter 1.631 --- Sulfasalazine --- p.46 / Chapter 1.632 --- Gold salts --- p.47 / Chapter 1 633 --- D-penicillamine --- p.48 / Chapter 1.634 --- Antimalarial --- p.49 / Chapter 1 .635 --- Methotrexate --- p.51 / Chapter 1.64 --- New trends for treatment of arthritis --- p.53 / Chapter 1.641 --- Anti-cytokine therapy --- p.53 / Chapter 1.642 --- Anti-angiogenesis therapy --- p.54 / Chapter 1.7 --- Aims of study --- p.57 / Chapter Chapter 2 --- Material and drugs --- p.62 / Chapter Chapter 3 --- Methodology --- p.62 / Chapter 3.1 --- Animals used and anaesthetization --- p.62 / Chapter 3.2 --- Measurement of plasma protein extravasation --- p.63 / Chapter 3.3 --- Measurement of knee joint sizes --- p.64 / Chapter 3.4 --- Measurement of knee joint blood flow --- p.65 / Chapter 3.5 --- Measurement of histological changes --- p.65 / Chapter 3.51 --- Dissection and fixation --- p.65 / Chapter 3.52 --- Decalcification --- p.66 / Chapter 3.53 --- Processing --- p.66 / Chapter 3.54 --- Embedding --- p.67 / Chapter 3.55 --- Sectioning --- p.67 / Chapter 3.56 --- Staining --- p.69 / Chapter 3.6 --- Data analysis --- p.69 / Chapter 3.61 --- Scoring systems --- p.72 / Chapter Chapter 4 --- A model of monoarthritis in rats --- p.72 / Chapter 4.1 --- Introduction --- p.72 / Chapter 4.2 --- Method --- p.73 / Chapter 4.3 --- Results --- p.73 / Chapter 4.31 --- Lewis rats --- p.73 / Chapter 4.32 --- Sprague-Dawley (SD) rats --- p.74 / Chapter 4.33 --- Comparison of FCA-induced changes in Lewis and SD rats --- p.74 / Chapter 4.34 --- Histological studies on arthritic SD rats --- p.75 / Chapter 4.4 --- Discussion --- p.93 / Chapter 4.5 --- Conclusions --- p.95 / Chapter Chapter 5 --- Effect of Substance P on adjuvant-induced arthritis --- p.96 / Chapter 5.1 --- Introduction --- p.96 / Chapter 5.2 --- Method --- p.98 / Chapter 5.3 --- Results --- p.99 / Chapter 5.31 --- Evans blue extravasation --- p.99 / Chapter 5.32 --- Joint size --- p.100 / Chapter 5.33 --- Knee joint blood flow --- p.101 / Chapter 5.34 --- Histology results --- p.102 / Chapter 5.341 --- Infiltration of immune cells in synovial tissue --- p.102 / Chapter 5.342 --- Synovial tissue proliferation --- p.102 / Chapter 5.343 --- Cartilage degradation --- p.103 / Chapter 5.344 --- Bone degradation --- p.103 / Chapter 5.4 --- Discussion --- p.120 / Chapter 5.5 --- Conclusions --- p.125 / Chapter Chapter 6 --- Effects of tachykinin receptor antagonists on FCA-induced arthritis / Chapter 6.1 --- Introduction --- p.126 / Chapter 6.2 --- Method --- p.128 / Chapter 6. 21 --- Intravenous NK1 receptor antagonists on FCA-induced arthritis --- p.128 / Chapter 6. 22 --- Intraperitoneal TK receptor antagonists on FCA-induced arthritis --- p.128 / Chapter 6.3 --- Results --- p.129 / Chapter 6.31 --- Intravenous NK1 227}0اreceptor antagonists on FCA-induced arthritis Evans blue extravasation and joint swelling --- p.129 / Chapter 6.32 --- Intraperitoneal tachykinin receptor antagonists on FCA- induced arthritis Evans blue extravasation and joint swelling --- p.129 / Chapter 6.33 --- Intraperitoneal tachykinin receptor antagonists on FCA- induced immune cell accumulation --- p.130 / Chapter 6.34 --- Intraperitoneal tachykinin receptor antagonists on FCA- induced synovial tissue proliferation --- p.131 / Chapter 6.35 --- Intraperitoneal tachykinin receptor antagonists on FCA- induced cartilage degration and bone erosion --- p.131 / Chapter 6.4 --- Discussion --- p.159 / Chapter 6.5 --- Conclusions --- p.162 / Chapter Chapter 7 --- Individual and combined effects of dexamethasone and TK receptor antagonists on FCA-induced arthritis --- p.163 / Chapter 7.1 --- Introduction --- p.163 / Chapter 7.2 --- Method --- p.166 / Chapter 7.3 --- Results --- p.167 / Chapter 7.31 --- Evans blue extravasation --- p.167 / Chapter 7.32 --- Knee joint size --- p.167 / Chapter 7.33 --- Body weight --- p.168 / Chapter 7.34 --- Cellular infiltration --- p.168 / Chapter 7.35 --- Synovial tissue proliferation --- p.168 / Chapter 7.36 --- Cartilage degradation --- p.169 / Chapter 7.4 --- Discussion --- p.184 / Chapter 7.5 --- Conclusions --- p.187 / Chapter Chapter 8 --- General discussions and conclusions --- p.188 / References --- p.192

by Keung Ka Man. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 163-184). / Abstracts in English and Chinese. / Abstract --- p.ii / 摘要 --- p.iv / Acknowledgements --- p.vi / Table of Contents --- p.vii / List of Abbreviations --- p.xiv / List of Tables --- p.xvi / List of Figures --- p.xvi / Chapter CHAPTER 1. --- INTRODUCTION / Chapter 1.1. --- Events happened after brain injury --- p.1 / Chapter 1.2. --- Glial cells --- p.3 / Chapter 1.2.1. --- Microglia --- p.4 / Chapter 1.2.2. --- Oligodendrocytes --- p.5 / Chapter 1.2.3. --- Astrocytes --- p.5 / Chapter 1.2.3.1. --- Uptake of neurotransmitters --- p.7 / Chapter 1.2.3.2. --- Maintenance of extracellular homeostasis --- p.8 / Chapter 1.2.3.3. --- Induction of blood-brain-barrier --- p.8 / Chapter 1.2.3.4. --- Guidance of migrating neurons during development --- p.9 / Chapter 1.2.3.5. --- Immunocompetent cells of the brain --- p.9 / Chapter 1.2.3.6. --- Contribution to astrogliosis --- p.10 / Chapter 1.3. --- Cytokines and astrogliosis --- p.11 / Chapter 1.3.1. --- IL-6 and astrogliosis --- p.12 / Chapter 1.3.2. --- IL-1 and astrogliosis --- p.13 / Chapter 1.3.3. --- IFN-γ and astrogliosis --- p.14 / Chapter 1.3.4. --- TNF-α and astrogliosis --- p.14 / Chapter 1.3.4.1. --- General properties of TNF-α --- p.15 / Chapter 1.3.4.2. --- TNF receptors (TNFRs) --- p.17 / Chapter 1.3.4.3. --- NFkB induction --- p.18 / Chapter 1.3.4.4. --- Intermediate early genes --- p.19 / Chapter 1.3.4.5. --- iNOS is the target of NFkB and AP-1 --- p.20 / Chapter 1.4. --- β-Adrenergic receptors (P-ARs) --- p.21 / Chapter 1.4.1. --- β-ARs and astrogliosis --- p.22 / Chapter 1.4.2. --- General properties of β-ARs --- p.23 / Chapter 1.4.3. --- Interactions between β-adrenergic mechanism and TNF-α --- p.24 / Chapter 1.5. --- Aims and scopes of the project --- p.25 / Chapter CHAPTER 2. --- MATERIALS & METHODS / Chapter 2.1. --- Materials --- p.29 / Chapter 2.1.1. --- Rats for astrocyte culture --- p.29 / Chapter 2.1.2. --- Cell culture materials --- p.29 / Chapter 2.1.2.1. --- Complete Dulbecco's Modified Eagle Medium:F12 (DF12) --- p.29 / Chapter 2.1.2.2. --- Phosphate buffered saline (PBS) --- p.30 / Chapter 2.1.3. --- Drugs preparation --- p.30 / Chapter 2.1.3.1. --- Recombinant cytokines --- p.30 / Chapter 2.1.3.2. --- Modulators of protein kinase A (PKA) --- p.30 / Chapter 2.1.3.3. --- Modulators of protein kinase C (PKC) --- p.31 / Chapter 2.1.3.4. --- β-Agonists and -antagonists --- p.31 / Chapter 2.1.3.5. --- Antibodies used in western blot analysis --- p.31 / Chapter 2.1.4. --- Reagents for cell proliferation determination --- p.32 / Chapter 2.1.5. --- Reagents for RNA isolation --- p.32 / Chapter 2.1.6. --- Reagents for reverse transcription-polymerase chain reaction (RT-PCR) --- p.32 / Chapter 2.1.7. --- Reagents for Electrophoresis --- p.33 / Chapter 2.1.8. --- Reagents and buffers for western blotting --- p.35 / Chapter 2.2. --- Methods --- p.36 / Chapter 2.2.1. --- Preparation of primary astrocytes --- p.36 / Chapter 2.2.2. --- Preparation of cells for assays --- p.36 / Chapter 2.2.3. --- Determination of cell proliferation --- p.36 / Chapter 2.2.3.1. --- [3H]-Thymidine incorporation assay --- p.37 / Chapter 2.2.3.2. --- MTT assay --- p.37 / Chapter 2.2.3.3. --- Data analysis --- p.38 / Chapter 2.2.4. --- Determination of RNA expression by RT-PCR analysis --- p.38 / Chapter 2.2.4.1. --- RNA extraction --- p.38 / Chapter 2.2.4.2. --- Spectrophotometric Quantitation of DNA and RNA --- p.38 / Chapter 2.2.4.3. --- RNA gel electrophoresis --- p.39 / Chapter 2.2.4.4. --- Reverse transcription-polymerase chain reaction (RT-PCR) --- p.39 / Chapter 2.2.4.5. --- Separation of PCR products by agarose gel electrophoresis --- p.40 / Chapter 2.2.4.6. --- Quantification of band density --- p.41 / Chapter 2.2.5. --- Determination of protein expression by Western blotting --- p.41 / Chapter 2.2.5.1. --- Total protein extraction --- p.41 / Chapter 2.2.5.2. --- Western blotting analysis --- p.42 / Chapter CHAPTER 3. --- RESULTS / Chapter 3.1. --- Effects of pro-inflammatory cytokines on astrocyte proliferation --- p.43 / Chapter 3.1.1. --- Effects of TNF-α on astrocyte proliferation --- p.44 / Chapter 3.1.2. --- Effects of TNF-R1 and -R2 antibodies on astrocyte proliferation --- p.47 / Chapter 3.1.3. --- Effects of other cytokines on astrocyte proliferation --- p.50 / Chapter 3.1.4. --- Comparisons of the effects of cytokines on astrocyte proliferation --- p.53 / Chapter 3.2. --- Effects of β-agonist and -antagonist on astrocyte proliferation --- p.55 / Chapter 3.3. --- Effects of TNF-α on the expression of TNFR and endogenous TNF-α in astrocytes --- p.60 / Chapter 3.3.1. --- Effects of TNF-α on the expression of TNF-R1 and -R2 in astrocytes --- p.60 / Chapter 3.3.1.1. --- Effects of TNF-α on the expression of TNF-R1 and -R2 mRNA --- p.60 / Chapter 3.3.1.2. --- TNFR subtypes involved in the TNF-α-induced TNF-R2 mRNA expression --- p.62 / Chapter 3.3.1.3. --- Signaling pathways of the TNF-α-induced TNF-R2 mRNA expression --- p.67 / Chapter 3.3.1.4. --- Effects of TNF-α on the expression of TNF-R1 and -R2 --- p.68 / Chapter 3.3.2. --- Effects of TNF-α on the expression of endogenous TNF-α in astrocytes --- p.73 / Chapter 3.3.2.1. --- Effects of TNF-α on the expression of TNF-α mRNA --- p.73 / Chapter 3.3.2.2. --- TNFR subtypes involved in the TNF-α-induced TNF-α mRNA expression --- p.73 / Chapter 3.3.2.3. --- Signaling pathways of the TNF-α-induced TNF-α mRNA expression --- p.74 / Chapter 3.3.2.4. --- Effects of other cytokines on the expression of TNF-α mRNA --- p.75 / Chapter 3.4. --- Effects of TNF-α on the expression of β1- and β2-AR in astrocytes --- p.85 / Chapter 3.4.1. --- Effects of TNF-α on the expression of β1- and β2-AR mRNA --- p.85 / Chapter 3.4.2. --- TNFR subtypes involved in the TNF-a-induced β1 and β2-AR mRNA expressions --- p.88 / Chapter 3.4.3. --- Signaling pathways of the TNF-α -induced β1- and β2-AR mRNA expressions --- p.88 / Chapter 3.4.4. --- Effects of TNF-α on the expression of β1- and β2-AR protein --- p.100 / Chapter 3.4.5. --- Effects of other cytokines on the expression of β1- and β2-AR mRNA --- p.100 / Chapter 3.5. --- Interactions between TNF-α and β-adrenergic mechanism in astrocytes --- p.107 / Chapter 3.5.1. --- Effects of β-agonists and -antagonists on the TNF-α-induced endogenous TNF-α expression in astrocytes --- p.107 / Chapter 3.5.1.1. --- Effects of ISO and PROP on the expression of TNF-α mRNA --- p.107 / Chapter 3.5.1.2. --- β-AR subtypes involved in the TNF-α-induced TNF-α mRNA expression --- p.108 / Chapter 3.5.2. --- Effects of β-agonists and -antagonists on the TNF-α-induced TNFRs expression in astrocytes --- p.112 / Chapter 3.5.2.1. --- Effects of ISO and PROP on the expression of TNFRs mRNA --- p.112 / Chapter 3.5.2.2. --- β-AR subtypes involved in the TNF-α-induced TNF-R2 mRNA expression --- p.115 / Chapter 3.6. --- Effects of TNF-α on the expression of transcription factors in astrocytes --- p.117 / Chapter 3.6.1. --- "Effects of TNF-α on c-fos, c-jun and NFKB/p50 expression" --- p.118 / Chapter 3.6.2. --- Effects of other cytokines on the expression of NFKB/p50 mRNA --- p.119 / Chapter 3.6.3. --- "TNFR subtypes involved in the TNF-α-induced c-fos, c-jun and NFKB/p50 mRNA expression" --- p.125 / Chapter 3.7. --- Effects of TNF-α on the expression of iNOS in astrocytes --- p.130 / Chapter 3.7.1. --- Effects ofTNF-α the expression of iNOS mRNA --- p.130 / Chapter 3.7.2. --- TNFR subtypes involved in the TNF-α-induced iNOS mRNA expression --- p.131 / Chapter 3.7.3. --- Signaling pathways of the TNF-α-induced iNOS mRNA expression --- p.136 / Chapter 3.7.4. --- Effects of other cytokines on the expression of iNOS mRNA --- p.139 / Chapter 3.7.5. --- Effects of β-agonists and -antagonists on the TNF-α-induced iNOS expression --- p.142 / Chapter 3.7.5.1. --- Effects of ISO and PROP on the expression of iNOS mRNA --- p.142 / Chapter 3.7.5.2. --- β-AR subtypes involved in the TNF-α-induced iNOS mRNA expression --- p.143 / Chapter CHAPTER 4. --- DISCUSSIONS & CONCLUSIONS / Chapter 4.1. --- Effects of TNF-α on astrocyte proliferation --- p.148 / Chapter 4.2. --- Roles of endogenous TNF-α and TNFR in astrocyte proliferation --- p.150 / Chapter 4.3. --- Interactions between TNF-α and β-adrenergic mechanism in astrocytes --- p.154 / Chapter 4.4. --- Induction of transcription factors by TNF-α in astrocytes --- p.157 / Chapter 4.5. --- Possible source of β-agonists --- p.159 / Chapter 4.6. --- Conclusions --- p.160 / REFERENCE --- p.163

O Fator de Necrose Tumoral-alfa (TNF-alfa) possui um importante papel na imunopatogênese da psoríase e agentes biológicos, como os inibidores de TNF-alfa, têm apresentado bons resultados no tratamento desta. No entanto, estes agentes foram associados ao aumento de casos de reativação de tuberculose entre os pacientes que os utilizaram. Este estudo foi realizado com o intuito de avaliar a resposta imune de pacientes com psoríase grave, ativa, sem tratamento, frente a antígenos de Mycobacterium tuberculosis (Mtb), e o efeito dos inibidores de TNF-alfa nesta resposta. Estudamos 24 pacientes com psoríase grave divididos em 2 grupos: não reatores (n = 14) e reatores (n = 10) ao teste intradérmico com PPD. Como controle, utilizamos um total de 26 indivíduos sadios, também separados em 2 grupos segundo a reatividade ao PPD (PPD-, n = 13; PPD+, n = 13). Em uma segunda etapa estudamos 11 pacientes com psoríase leve a moderada, também sem tratamento, PPD (-) para avaliarmos a importância da gravidade da psoríase na resposta aos antígenos micobacterianos. Avaliamos a resposta imunológica in vitro através da linfoproliferação, quantificação da produção de IFN-gama (ELISA) e quantificação de células produtoras de IFN-gama (ELISPOT), na presença e ausência dos inibidores de TNF-alfa (infliximab e etanercepte), utilizando os antígenos purificados ESAT-6, Ag85B e o antígeno bruto sonicado da cepa H37Rv (AgSMtb), e o mitógeno fitohemaglutinina (PHA). Os pacientes com psoríase grave PPD (-) apresentaram reposta linfoproliferativa e níveis de IFN-gama menores que nos controles PPD (-). Os pacientes com psoríase leve a moderada apresentaram resposta imune intermediária entre controles e pacientes graves. Em relação aos inibidores de TNF- alfa, verificou-se que infliximab e etanercepte apresentaram diferença em suas capacidades de inibição, sendo que somente o infliximab ocasionou a inibição total de TNF-alfa. Em contrapartida o etanercept manteve a produção de TNF-alfa, e em alguns casos elevou sua produção. Estes diminuíram apenas parcialmente a reatividade in vitro dos pacientes com psoríase, uma vez que a secreção de IFN-gama e o número de células produtoras de IFN-gama não foram alterados na presença dos inibidores. A secreção de IL-10 foi diminuída tanto na presença do infliximab, quanto na presença do etanercepte. Os dados obtidos permitem concluir que (a) os pacientes com psoríase grave PPD (-) apresentam uma baixa reatividade in vitro, principalmente das respostas que avaliam linfócitos T de memória central, aos antígenos de Mtb, sendo que essa baixa reatividade não está totalmente relacionada com a gravidade da doença, uma vez que os pacientes com psoríase leve a moderada apresentaram resposta intermediária a dos controles e pacientes com psoríase grave; (b) e que apesar dos inibidores de TNF- alfa promoverem uma inibição parcial da resposta imune, a reativação da tuberculose estaria mais relacionada à própria ausência de TNF-alfa, não compensada pela atuação isolada, e provavelmente insuficiente, de IFN-gama na manutenção do granuloma, do que a outras substanciais modificações na resposta imunológica frente aos antígenos micobacterianos. / Tumor necrosis factor alpha (TNF-alpha) has a pivotal role in psoriasis pathogenesis and biologic agents, such as TNF-alpha inhibitors, have provided good results in its treatment. However, the use of these agents has been associated with an increase in the number of cases of tuberculosis reactivation. This study aimed to evaluate the immune response of severe psoriasis patients, with active, untreated disease to relevant Mycobcterium tuberculosis antigens, and the effect of the TNF-alpha inhibitors (infliximab and etanercept) in this response. Twenty four severe psoriasis patients were enrolled and divided in two groups according to their reactivity to the tuberculin skin test: TST (n= 14) and TST + (n=10). As controls, we studied 26 healthy donors, also divided in two groups to the TST reactivity (TST -, n=13; TST+, n=13). Eleven mild to moderate psoriasis patients, untreated, TST (-) were studied to evaluated the role of psoriasis severity in the immune response to the mycobacterial antigens. Immune responses were evaluated in vitro by the lymphocyte proliferative response (LPR) assay, ELISA for IFN-? secretion by peripheral blood mononuclear cells and enumeration of IFN-? secreted cells (ELISPOT) induced in response to the purified antigens ESAT-6, Ag85B and a crude sonicated antigen preparation from H37Rv Mtb strain (AgSMtb), as well as to the mitogen phytohemagglutinin (PHA), in the presence or absenceinflimab/etanercept. The LPR and IFN-g secretion to Mtb antigens were lower in TST- severe psoriasis patients than TST- controls. Mild to moderate psoriasis patients had intermediate responses, between controls and severe psoriasis patients. The TNF-a inhibitors infliximab and etanercept showed differences in their inhibitiory activity, since only infliximab was capable to neutralize all TNF-a. On the other hand, etanercept kept TNF-alpha production, and in some cases even increased its production. The TNF-alpha inhibitors diminished partially the in vitro patients immune responses, since the IFN-? secretion and enumeration of IFN-? secreted cells were not affected. IL-10 secretion was diminished with both TNF-a inhibitors. In conclusion: (a) TST(-) severe psoriasis patients have decreased in vitro reactivity, mainly in those responses that evaluate central memory T-cell responses, to Mtb antigens, and this decrease could not be fully explained by disease severity, since mild psotiasis patients had intermediate responses; (b) and despite the fact that TNF-alpha inhibitors promote a partial immune response inhibition, tuberculosis reactivation could be related more with the lack of TNF-alpha, which was probably not compensated by the IFN-g activity alone, probably insufficient, to the support granuloma formation, than other defects of the immune response to Mtb antigens.

The regulation of systemic immune responses is dependent on individual cell responses that will concur to induce a coherent response against a stimulus. In turn, cell response is dependent on the processing of intracellular signals generated at the cell membrane and transmitted through successive protein modifications to the nucleus in order to activate gene transcription. This is referred to as intracellular signalling. Tight control of these mechanisms is required to generate an appropriate cell response to environmental stimulations and globally to establish an appropriate immune response. Among protein modifications used to transmit a signal to the nucleus, protein tyrosine phosphorylation represents a pivotal method used by immune cells to rapidly induce signalling. While protein tyrosine kinases (PTKs) phosphorylate proteins, protein tyrosine phosphatases (PTPs) regulate the signalling by removing the phosphate group. The goal of this study was to better characterize intracellular signalling events involved in allergic asthma, a chronic inflammatory disease involving a Th2 immune response. In a first time, we investigated the role of PTPs in the development of asthma. We show that inhibition of global PTP activity in mice, during either the allergen sensitization or the allergen challenge phase, reduces asthma development and is linked to an increased Th1 response in the spleen and lung. Secondly, we revealed that TC-PTP inhibition reduces asthma development, while PTP-1B inhibition exacerbates inflammatory cells recruitment to the lung. Inhibition of either SHP-1 or PTP-PEST activity did not significantly modulate asthma development in our model. In a third set of experiments, we got interested in the signalling pathways triggered by the pro-inflammatory molecules myeloid-related proteins (MRPs) 8 and 14. MRPs are small cytosolic proteins recently described to have extracellular functions. MRP8 expression is resistant to corticosteroid treatment, and potentially promotes inflammation in corticosteroid-treated patients. We identified that MRPs induce signal through the action of TLR-4 and trigger the activation of MEK/ERK and JNK pathways that lead to NF-kappaB translocation. Collectively, our data provide a new characterization of signalling pathways engaged in allergic asthma. This should be helpful in the elaboration of new therapeutic approaches targeting precise pathways to inhibit mechanisms of inflammation.

Our lab has previously reported the identification of a novel endogenous 19-nor steroid, estradienolone (ED), in pregnant women that strongly bound to sex hormone binding globulin. Estrogen-receptor related receptors (ERRs), which have no known natural ligands, are a family of orphan receptors consisting of 3 isoforms: ERRalpha, ERRbeta and ERRgamma. The ERRs have been shown to actively modulate estrogenic responses, to play an essential role in pregnancy, and are implicated in breast cancer prognosis. My results show that ED acts as an antagonist of the ERRalpha confirming preliminary results obtained by our group. Studies of cellular responses demonstrate that ED has strong anti-mitogenic properties. ED inhibited the growth of both estrogen receptor (ER)-positive (MCF-7) and ER-negative (MDA-MB-231) breast cancer cells in a dose-dependent manner but did not have any effects on the proliferation of the non-cancerous immortalized epithelial breast MCF-10A cells. The finding that ED inhibits proliferation of both ER negative and ER positive breast cancer cells, and regulate ERR transcriptional activity may have important ramifications in breast cancer therapy.

The active form of vitamin D, 1,25-dihydroxyvitamin D3 (1,25D), is a key calcium (Ca++) regulatory hormone. It is also associated with functions unrelated to Ca++ homeostasis. Here, special attention is paid towards the anticancer properties of 1,25D. 1,25D strongly inhibits the growth of well-differentiated head and neck squamous cell carcinoma (HNSCC) derived cell lines. However, advanced, less differentiated, HNSCC cell lines (e.g. SCC4) are partially resistant to 1,25D. Resistance to nuclear receptor (NR) agonists is a common event that occurs in other NR-related treatments. For example, some leukemias develop resistance to the usually effective retinoic acid (RA) treatment. However, treating RA-resistant cells with HDAC inhibitors (HDACi) sensitizes them to RA. Thus, this study aims to investigate how treatment with TSA, an HDACi, would affect the response of SCC4 cell lines to 1,25D. We found that TSA had a variety of effects on 1,25D-regulated gene expression. Combined treatment with 1,25D and TSA increased the expression of cell-cycle regulating proteins, but also enhanced the downregulation of key target genes. Given the potential of the 1,25D/HDACi combination in combating cancers, two chimeric compounds, each containing parts of 1,25D and an HDACi, were synthesized in collaboration with Dr. James Gleason (Dept. of Chemistry, McGill). These 1,25D analogs have the HDACi-like structure replacing the 1,25D side chain. Both compounds proved to be agonists of the vitamin D receptor. Moreover, the TSA-substituted compound, called triciferol, effectively induced a-tubulin as well as histones acetylation. This study underlines the potential of combining 1,25D and TSA in cancer treatment, and reveals that bi-functional 1,25D analogs can be produced with potentially enhanced therapeutic activity.