Cheng, Cho Yiu. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 186-217). / Abstracts in English and Chinese. / Acknowledgements --- p.1 / Abstract of thesis --- p.2 / Abstract of thesis in Chinese --- p.7 / Presentation attended --- p.9 / Chapter Chapter 1: --- Introduction and Background --- p.13 / Chapter 1.1 --- Anatomy and functions of human prostate gland --- p.13 / Chapter 1.2 --- Worldwide epidemiology of prostate cancer --- p.15 / Chapter 1.3 --- Prostate cancer stages and treatments in clinic --- p.21 / Chapter 1.4 --- Introduction to nuclear receptors --- p.23 / Chapter 1.5 --- Nuclear receptor structure --- p.24 / Chapter 1.6 --- Nuclear receptors nomenclature and classification --- p.28 / Chapter 1.7 --- Mode of action for nuclear receptors --- p.34 / Chapter 1.8 --- Co-regulators of nuclear receptors --- p.35 / Chapter 1.9 --- Nuclear receptors related to prostate cancer --- p.43 / Chapter Chapter 2: --- Aim of study and experimental design --- p.59 / Chapter 2.1 --- Aim of study --- p.59 / Chapter 2.2 --- In vitro cell lines models used in the study --- p.60 / Chapter Chapter 3: --- Materials and methods --- p.64 / Chapter 3.1 --- Apparatus and preparation throughout the study --- p.64 / Chapter 3.2 --- Cells culture --- p.64 / Chapter 3.3 --- RNA extraction --- p.67 / Chapter 3.4 --- Reverse transcription --- p.68 / Chapter 3.5 --- Primers specificity checking --- p.69 / Chapter 3.6 --- Real time quantitative polymerase chain reaction --- p.84 / Chapter 3.7 --- Data analysis --- p.90 / Chapter Chapter 4: --- Results --- p.92 / Chapter 4.1 --- Expression of nuclear receptors transcripts in each prostatic cell lines used --- p.92 / Chapter 4.2 --- Expression of nuclear receptor transcripts in immortalized prostatic epithelial BPH-1 and BPH-1 derived cell lines model --- p.116 / Chapter 4.3 --- Expression of nuclear receptor transcripts in androgen-dependent and androgen-independent classical prostatic cancer cell lines model --- p.121 / Chapter 4.4 --- Expression of nuclear receptor transcripts in androgen-independent and antiandrogen-resistant LNCaP derived cell lines model --- p.125 / Chapter Chapter 5: --- Discussion --- p.129 / Chapter 5.1 --- Special expression pattern of some nuclear receptors in the prostatic cell lines or prostatic cancer cell lines --- p.129 / Chapter 5.2 --- BPH-1 and BPH-1 derived cell lines model --- p.138 / Chapter 5.2.1 --- Prostatic cell lines model studying the transformation and invasion in prostate cancer (BPH-1 Snail & BPH-1 CAFTDs versus BPH-1) --- p.138 / Chapter 5.2.2 --- Prostatic cell lines model studying the transformation and invasion in prostate cancer (BPH-1 Snail & BPH-1 CAFTDs versus BPH-1 AR) --- p.159 / Chapter 5.3.3 --- classical prostatic cancer cell lines model --- p.162 / Chapter 5.3.1 --- Prostatic cancer cell lines model studying androgen-dependence and androgen-independence (DU145 & PC-3 versus LNCaP) --- p.163 / Chapter 5.4 --- LNCaP and LNCaP derived cell lines model --- p.170 / Chapter 5.4.1 --- Prostatic cancer cell lines model studying androgen-independence and antiandrogen-resistance (LNCaP-abl & LNCaP-BCs versus LNCaP) --- p.171 / Chapter Chapter 6: --- Conclusion --- p.179 / References --- p.186

研究背景和研究目的 / 前列腺癌是許多西方國家男性人群中最常見的惡性腫瘤。最新癌症統計結果表明，前列腺發病例和致死率在亞洲國家尤其是中國和香港地區呈迅猛上升趨勢(2009年，本港前列腺癌發病率列所有腫瘤發病率中第三位，致死率列第五位)。目前前列腺癌治療策略主要集中在拮抗雄激素信號通路。然而，臨床實踐表明，這種治療方式除了引起由於體內激素水平失調產生的一系列副作用之外，往往導致疾病進展到令人棘手的去勢治療無效階段。因此，從分子水平更為深入的理解前列腺癌疾病進展過程對於最終攻克前列腺癌具有重要的研究價值。雌激素相關受體是孤兒核受體的亞組之一，包括 α, β, γ三個亞型。該組受體在結構上與α亞型雌激素受體具有很高的同源性。已有研究表明，α亞型雌激素相關受體直接调控涉及氧化磷酸化，線粒體生物發生和脂肪酸氧化的相關基因表達，從而在細胞能量代謝調節中發揮至關重要作用。最新研究發現， α亞型雌激素相關受體的高表達在包括乳腺癌和前列腺癌在內的一系列腫瘤中與疾病的進展和不良預後高度相關。這提示該受體可能參與這些腫瘤的惡性進展。腫瘤細胞對低氧環境的耐受是實體腫瘤的標誌性表型之一，同時也有研究表明這一機制可能在癌細胞的惡性克隆選擇中發揮了重要作用。在眾多低氧耐受的機制中，細胞能量代謝方式轉換被研究人員看作重要的調節通路之一。考慮到前列腫瘤的低氧微環境以及α亞型雌激素相關受體在能量代谢過程的重要調節作用，有理由推測在該受體可能在前列腺癌細胞低氧耐受中發揮了積極的作用進而促進前列腺癌的惡性進展。 / 材料和方法 / 為了研究α亞型雌激素相關受體在前列腺癌細胞低氧耐受中的功能，本次研究採取了下列實驗方法：1）用免疫組化方法考察α亞型雌激素相關受體在人前列腺癌組織中的表達情況；2）用合適的前列癌細胞系建立α亞型雌激素相關受體穩定過表達細胞系同時研究這些穩轉細胞系的體外生長表型；）研究雌激素相關受體穩定過表達細胞系在低氧环境下的體外生長表型；）研究雌激素相關受體穩定過表達細胞系在免疫缺陷小鼠中的致瘤能力同時用免疫組化方法考察其腫瘤血管生成情況；）用定量 PCR和免疫印跡(Western blot)方法檢測低氧誘導因子-1α亞基(HIF-1α)及其信號通路中相關基因在α亞型雌激素相關受體穩定過表達細胞系中的表達水平，同時用雙螢光素酶報告基因方法考察α亞型雌激素相關受體對低氧誘導因子‐1(HIF-1)靶基因啟動子的轉錄激活效應；5）用 shRNA介導的基因阻斷的方法進一步考察α亞型雌激素相關受體對前列腺癌細胞低氧耐受的影響；6）通過觀考察用α亞型雌激素相關受體選擇性抑製劑 XCT790處理細胞對其在低氧環境下的體外生長情況的作用，進一步闡明 α亞型雌激素相關受體對前列腺癌細胞低氧耐受的影響；7）用免疫印跡 (Western blot)，免疫共沉澱 (Co-IP)和熒光能量共振轉移(FRET)分析的方法考察α亞型雌激素相關受體對低氧誘導因子‐1α亞基表蛋白表達和穩定性以及對低氧誘導因子 -1信號通路的影響。 / 結果 / 本研究所得得到的結果簡要總結如下：1）α亞型雌激素相關受體在前列癌組織中的免疫反應性呈現隨著惡性程度升高而增加的趨勢；2）α亞型雌激素相關受體在人前列腺癌細胞系 LNCaP中的過表達能提升其在常氧和低氧環境下的體外細胞增殖，細胞集落形成，細胞對胞外基質的粘附以及細胞侵襲能力； 3) α亞型雌激素相關受體在人前列腺癌細胞系 LNCaP中的過表達能促進其體內腫瘤形成及腫瘤血管生成； 4）過表達 α亞型雌激素相關受體能上調低氧誘導因子-1α亞基的蛋白水平並提高其轉錄活性；5）shRNA介導的α亞型雌激素相關受體 mRNA阻斷可以削弱人前列腺癌細胞系 LNCaP細胞在低氧環境下的體外生長能力；6）在体外用α亞型雌激素相關受體選擇性抑製劑 XCT790处理人前列腺癌細胞系 LNCaP細胞可能通過減少低氧誘導因子‐1α亞基蛋白表達水平從而抑制其在低氧環境下的細胞生長能力；7）α亞型雌激素相關受體可以直接與低氧誘導因子-1α亞基相互作用，並且這種相互作用可能有助於抑制低氧誘導因子-1 α亞基的蛋白降解。 / 結論 / 本研究獲得結果提示，α亞型雌激素相關受體可能通過提高低氧誘導因子-1α亞基的蛋白水平及激活低氧誘導因子-1信號通路從而促進前列腺癌細胞在低鹽環境下的細胞生長能力。体外用 shRNA介導的α亞型雌激素相關受體 mRNA阻斷方法和α亞型雌激素相關受體選擇性抑製劑处理都有可能通過阻止低氧誘導因子‐1α亞基以削弱前列腺癌細胞在低鹽環境下的細胞生長能力。同時， α亞型雌激素相關受體能直接與低氧誘導因子-1 α亞基相互作用而這種相互作用有可能有助於抑制其蛋白降解，這些結果提示 α亞型雌激素相關受體可能在前列腺癌進展過程中的低氧耐受中發揮積極作用。 / Background and aims of study / Prostate cancer is the most common cancer in many Western counties among the male populations. Latest cancer statistics also show that its incidence and mortality rates are rapidly increasing in China and Hong Kong (Prostate cancer ranked the 3rd common cancer and 5th cancer causing death in Hong Kong in 2009). Current therapeutic strategies of prostate cancer mainly target to the antagonizing androgen signaling pathway, which usually drives the disease to the impasse of castration resistance albeit the side effects caused by the imbalance of hormone. The substantial clinical significance of prostate cancer is urgent to better understand the progression of this disease. Estrogen-related receptors (α,β,γ) are a subgroup of ligand-independent orphan nuclear receptors, which is constitutively activated without binding any physiological ligands and all share high homology with the estrogen receptor alpha (ER α) structurally. Previous studies indicates that ERR α plays a pivotal role in cellular energy home stasis regulation, target genes of which are involved in the procedures of oxidative phosphorylation, mitochondrial biogenesis and fatty acid oxidation. Recent studies reveals that high expression of ERR α may be useful as a poor prognostic marker in both hormone-dependent and hormone-independent cancers (including breast cancer and prostate cancer), which implicates this nuclear receptor may be involved in the advanced malignant progression of these cancers. Adaptation to hypoxia is one of the hallmark features of solid tumors and it is conceived to play an important role in malignant clonal selection of cancer cells. Among the diverse mechanisms on cellular hypoxia adaptation, energy metabolism reprogramming is characterized and considered as a critical regulatory pathway. Given the hypoxic microenvironment of prostate cancer and the energy regulatory role of ERR α, it is hypothesized that ERR α might play an active role in the cellular hypoxic adaptation of prostate cancer hence advancing the progre sion of this disease. / Materials and methods / To investigate the functional significance of ERR α in cellular hypoxic adaptation of prostate cancer, the following experimental approaches were employed and performed in my thesis study: 1) to survey the expression pattern of ERR α in human prostate cancer tissues by immunohistochemical staining; 2) to generate ERR α-stable expressing cell lines in selected prostate cancer cell lines and functionally characterize their in vitro phenotypes under normoxia condition; 3) to characterize in vitro hypoxic-response phenotypes of ERR α-infectants; 4) to determine the tumorigenicity of ERR α-infectants in immuno-deficient SCID mice and to investigate their tumor angiogenesis by immunohistochemical staining; 5) to determine the HIF-1α signal cohort in ERR α-infectants by both RT-PCR and immuno blot analysis and to investigate the transactivation effect of ERR α on HIF-1 targeting genes promoters by dual luciferase reporter assay; 6) to further characterize the hypoxic adaptation phenotypes induced by ERR α transduction using shRNA-mediated gene knockdown approach; 7) to further elucidate the effect of ERR α on the hypoxic cell growth regulation of prostate cancer by treating ERR α-infectants with an ERR α-selective antagonist XCT790; 8) to further investigate the mechanisms via which ERR α interferes with the protein expression or stabilization of HIF-1α as well as HIF-1 signal cohort using immuno blot analysis, immunoprecipitation assays and fluorescence resonance energy transfer (FRET) analysis. / Results / My results are briefly summarized as follows: 1) ERR α exhibited an increased immuno expression pattern in high-grade prostate cancer; 2) Ectopic expression of ERR α in LNCaP prostate cancer cell line could promote its in vitro cell proliferation, clonal formation, cell-extracellular matrix attachment and cell invasion capacities under both normoxic and hypoxic conditions; 3) Ectopic expression of ERR α in LNCaP prostate cancer cell line could promote its in vivo tumorigenicity and tumor angiogenesis; 4) Overexpression of ERR α could up-regulate protein level of hypoxia regulatory transcriptional factor-1(HIF-1) α subunit (HIF1-α) and enhance its transcriptional activity; 5) mRNA knock-down of ERR α could attenuate in vitro cell growth capacity of LNCaP prostate cancer cell line under hypoxic condition; 6) Treatment with an ERR α specific antagonist XCT790 could inhibit in vitro hypoxic cell growth of LNCaP cells via its effect on decreasing the protein level of HIF-1α; 7) ERR α could physically interact with HIF-1α and such ERR α-HIF1-α interaction might help to inhibit protein degradation of HIF-1α. / Conclusion / The results obtained in this study indicated that ERR α could promote the hypoxic cell growth of prostate cancer via its enhancing the protein level of HIF-1α and activation of HIF-1 signal cohort. Both treatment with ERR α selective antagonist and down-regulating of ERR α by shRNA-mediated gene knockdown approach could attenuate the hypoxia adaptation of prostate cancer cells, which might be mediated by their suppression of the protein level of HIF1α. ERR α could directly interact with HIF-1α and such interaction might help to suppress the protein degradation of HIF1α, suggesting that ERR α may play an active role in hypoxic adaptation in advancing of prostate cancer. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Zou, Chang. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 138-160). / 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 / ACKNOWLEDGEMENTS --- p.viii / PUBLICATIONS --- p.ix / CONTENTS --- p.x / ABBREVIATIONS --- p.xiii / Chapter CHAPTER 1 --- Introduction --- p.1 / Chapter 1.1 --- Prostate cancer --- p.2 / Chapter 1.1.1 --- Epidemiology --- p.2 / Chapter 1.1.2 --- Risk factors --- p.3 / Chapter 1.1.3 --- Patho-physiology --- p.6 / Chapter 1.1.4 --- Diagnosis and treatment --- p.8 / Chapter 1.2 --- Androgen,androgen receptor and prostate cancer --- p.10 / Chapter 1.2.1 --- Androgen and androgen receptor --- p.10 / Chapter 1.2.2 --- Castration Resistance Prostate Cancer (CRPC) --- p.12 / Chapter 1.2.2.1 --- Overexpression of AR --- p.13 / Chapter 1.2.2.2 --- Increasing sensitivity to and rogen --- p.13 / Chapter 1.2.2.3 --- AR mutation --- p.14 / Chapter 1.2.2.4 --- Deregulation of AR regulator factors --- p.15 / Chapter 1.2.2.5 --- Outlaw pathway --- p.15 / Chapter 1.2.2.6 --- AR-independent pathway --- p.16 / Chapter 1.3 --- Estrogen and prostate cancer --- p.17 / Chapter 1.3.1 --- Overview of estrogen and estrogen receptors --- p.17 / Chapter 1.3.2 --- Estrogen signaling pathway andprostatecancer --- p.18 / Chapter 1.4 --- Nuclear receptors --- p.20 / Chapter 1.4.1 --- Overview of NRs superfamily --- p.20 / Chapter 1.4.2 --- Classification --- p.21 / Chapter 1.4.3 --- NRs as therapeutic targets for cancer treatment --- p.23 / Chapter 1.5 --- Estrogen-related receptors --- p.25 / Chapter 1.5.1 --- NR3B subgroup --- p.25 / Chapter 1.5.2 --- Isoforms --- p.26 / Chapter 1.5.3 --- Structure --- p.27 / Chapter 1.5.4 --- Ligand --- p.28 / Chapter 1.5.5 --- Co-regulators --- p.31 / Chapter 1.5.6 --- Tissue-specific expression pattern and identifiedfunction --- p.32 / Chapter 1.5.6.1 --- Tissue-specific expression pattern --- p.32 / Chapter 1.5.6.2 --- Identified physiological function of ERRs --- p.33 / Chapter 1.5.7 --- ERRs and cancer --- p.35 / Chapter 1.5.7.1 --- ERRβ/γ and cancer --- p.35 / Chapter 1.5.7.2 --- Expression of ERRα in cancer --- p.37 / Chapter 1.5.7.3 --- Identified functional roles of ERRα in cancer --- p.40 / Chapter 1.5.7.4 --- Regulation of ERRα in cancer cells --- p.42 / Chapter 1.6 --- Hypoxiaadaptation andcancer --- p.47 / Chapter 1.6.1 --- HIFs isoforms and structure --- p.47 / Chapter 1.6.2 --- Structure --- p.48 / Chapter 1.6.3 --- Regulation of HIF-1α expression --- p.49 / Chapter 1.6.3.1 --- Regulation of HIF-1α mRNA transcription --- p.49 / Chapter 1.6.2.2 --- Regulation of HIF-1α mRNA transcription --- p.50 / Chapter 1.6.2.3 --- O₂-dependent regulation of stability of HIF-1α protein --- p.51 / Chapter 1.6.2.4 --- O₂-independent regulation of HIF-1α --- p.52 / Chapter 1.6.2.5 --- Genetranscriptional regulation role of HIFs --- p.54 / Chapter 1.6.3 --- HIFs and cancer --- p.55 / Chapter 1.6.3.1 --- Overview --- p.55 / Chapter 1.6.3.2 --- Expression of HIF-1α in cancer progression --- p.55 / Chapter 1.6.3.2 --- Functional roles of HIF-1α in cancer progression --- p.56 / Chapter CHAPTER 2 --- Aims of study --- p.58 / Chapter CHAPTER 3 --- Materials and methods --- p.61 / Chapter 3.1 --- Cell lines and cell culture --- p.62 / Chapter 3.2 --- Human Prostatic Tissues --- p.64 / Chapter 3.3 --- RNA isolation and Reverse transcriptional-PCR --- p.64 / Chapter 3.3.1 --- Total RNA extraction --- p.64 / Chapter 3.3.2 --- Reverse transcription reaction --- p.65 / Chapter 3.3.3 --- Polymerase Chain Reaction for gene expression detection --- p.66 / Chapter 3.4 --- Plasmids construction --- p.69 / Chapter 3.4.1 --- Genomic DNA extraction --- p.69 / Chapter 3.4.2 --- PCR for cloning and sub-cloning --- p.70 / Chapter 3.4.3 --- PCR for mutant generation --- p.70 / Chapter 3.4.4 --- Restriction enzymes cut and ligation --- p.71 / Chapter 3.5 --- Antibody and reagents --- p.73 / Chapter 3.6 --- Immunohistochemistry --- p.74 / Chapter 3.7 --- Western Blot Analysis --- p.75 / Chapter 3.7.1 --- Protein extraction --- p.75 / Chapter 3.7.2 --- Electrophoresis, Protein blotting and Colorimetric detection --- p.76 / Chapter 3.8 --- Retroviral transduction and generation of ERRα poolandstable clones --- p.77 / Chapter 3.9 --- In vitro Cell Growth Assays --- p.77 / Chapter 3.9.1 --- Cell counting --- p.77 / Chapter 3.9.2 --- 5-Bromodeoxyuridine (BrdU) incorporation assay --- p.78 / Chapter 3.9.3 --- MTT assay --- p.79 / Chapter 3.9.4 --- In vitro clonal formation assay --- p.79 / Chapter 3.10 --- Cell attachment assay --- p.80 / Chapter 3.11 --- Transwell cell invasion assay --- p.81 / Chapter 3.12 --- In vivo tumorigenicity assay --- p.81 / Chapter 3.13 --- RNA interference --- p.82 / Chapter 3.14 --- Transient Transfection and Luciferase Reporter Assay --- p.83 / Chapter 3.15 --- Immuno-precipitation (IP) assay --- p.84 / Chapter 3.16 --- Fluorescence Resonance Energy Transfer (FRET) detection --- p.85 / Chapter 3.17 --- In vitro treatment with XCT790, cycloheximide and MG-132 --- p.86 / Chapter CHAPTER 4 --- Reuslts --- p.88 / Chapter 4.1 --- ERRα exhibits an increased expression pattern in high grade prostate cancer --- p.89 / Chapter 4.2 --- Ectopic expression of ERRα in LNCaP prostate cancer cell line can promote its in vitro cell proliferation, clonal formation, cell attachment and cell invasion capacity under normoxic condition --- p.91 / Chapter 4.3 --- Ectopic expression of ERR α in LNCaP prostate cancer cell line can promote its in vitro cell proliferation, clonal formation, cell attachment and cell invasion capacities under hypoxic condition --- p.94 / Chapter 4.4 --- Ectopic expression of ERR α in LNCaP prostate cancer cells can promote their in vivo tumorigenicity and tumor angiogenesis. --- p.97 / Chapter 4.5 --- Overexpression of ERRα can up‐regulate protein level of HIF-1α and enhance its transcriptional activity --- p.99 / Chapter 4.6 --- mRNA Knock-down of ERRα can attenuate in vitro cell growth of LNCaP prostate cancer celll line under hypoxic condition --- p.107 / Chapter 4.7 --- Treatment with an ERRα specific antagonist XCT790 can inhibit in vitro hypoxic cell growth of LNCaP cells via its effect on decreasing the protein level of HIF-1α --- p.110 / Chapter 4.8 --- ERRα can physically interact with HIF-1α and such ERRα-HIF-1α interaction helps to inhibit protein degradation of HIF-1α --- p.114 / Chapter CHAPTER 5 --- Discussion --- p.119 / Chapter CHAPTER 6 --- Summary --- p.134 / References --- p.138

肥大細胞是過敏和炎症的主要效應細胞，其激活機制包括了IgE依賴性和非IgE依賴性的激活。IgE依賴性激活是指抗原與IgE的高親和力受體FcεRI上的IgE結合，促使FcεRI受體交聯而引起變態反應。其它的肥大細胞促分泌素如神經肽P物質，能夠激活百日咳毒素（PTX）敏感性的G蛋白而介導非IgE依賴性的細胞激活。最近的研究指出，肥大細胞表達Toll樣受體家族，提示肥大細胞也積極參與固有免疫反應。本研究主要探討Toll樣受體2激動劑肽聚糖（PGN）和合成激動劑Pam3CSK4對人類肥大細胞的影響，及其對抗原和P物質引起的肥大細胞激活的調控。 / Toll樣受體2激動劑本身不引起人類肥大細胞脫顆粒，但抑制抗原和P物質引起的肥大細胞脫顆粒。鈣動員是引起肥大細胞脫顆粒的關鍵因素。Pam3CSK4通過抑制抗原和P物質鈣動員來抑制肥大細胞脫顆粒。PGN只抑制抗原鈣動員，卻對P物質沒有影響。 / PGN和Pam3CSK4皆刺激人類肥大細胞釋放白細胞介素8(IL-8)和腫瘤壞死因子α（TNF-α）。Pam3CSK4通過激活G₀蛋白，Erk，Ca²⁺/calcineurin/NFAT和TAK信號通路引起肥大細胞釋放IL-8。其間，Go蛋白的激活介導Erk和Ca²⁺/calcineurin/NFAT信號通路的活化。與Pam3CSK4不同，PGN通過激活JNK, Erk, PI3K和TAK信號通路引起肥大細胞釋放IL-8。此外，雖然PTX敏感性G蛋白不影響PGN刺激引起的IL-8釋放，它卻抑制PGN刺激引起的Erk激活。 / Pam3CSK4與抗原協同作用刺激肥大細胞釋放IL-8和TNF-α，PGN與抗原卻並無協同作用。PGN與P物質協同作用刺激肥大細胞釋放IL-8和TNF-α，Pam3CSK4卻幹擾P物質的作用。在Pam3CSK4與抗原的協同作用中，Erk，Ca²⁺/calcineurin/NFAT和TAK信號通路起重要作用。PGN與P物質的協同作用則通過Erk, Ca²⁺/calcineurin/NFAT，NF-κB，PI3K和TAK這五條信號通路。 / 本研究表明，不同的Toll樣受體2激動劑能通過不同的作用機制介導和調控人類肥大細胞的反應。同時，我們首次發現G₀蛋白參與人類肥大細胞Toll樣受體2信號的激活。由於Toll樣受體2與感染和炎症息息相關，繼續研究Toll樣受體2激活對人類肥大細胞的調控機制，有助於促進開發抗感染和炎症藥物，意義深遠。 / Mast cells are activated by IgE-dependent and -independent mechanisms and play a pivotal role in both allergic and inflammatory responses. The classical IgE-dependent mechanism involves the binding of antigens to the receptor-bound IgE and crosslinking of the high-affinity receptor for IgE (FcεRI). For the poly-basic secretagogues, such as the neuropeptide substance P, they can directly stimulate pertussis toxin (PTX)-sensitive G proteins in mast cells in an IgE-independent manner. Recent studies also discover the expression of the Toll-like receptors on mast cells, indicating that mast cells are active players in innate immunity against a wide variety of pathogens. In this study, we investigated the effects of Toll-like receptor 2 (TLR2) ligands peptidoglycan (PGN) and Pam3CSK4 on human mast cell line LAD2 cells activation and the modulatory effects of these TLR2 ligands on LAD2 cells activities in response to anti-IgE and substance P. / TLR2 ligands did not cause significant degranulation on their own, but inhibited anti-IgE and substance P induced degranulation. Pam3CSK4 acted through TLR2, while the inhibitory effect of PGN involved other non-TLR2 related mechanisms. Pretreatment of Pam3CSK4 inhibited calcium mobilization induced by anti-IgE and substance P. However, pretreatment of PGN only inhibited calcium mobilization induced by anti-IgE, but failed to demonstrate similar effect on substance P. / Both TLR2 ligands triggered the release of IL-8 and TNF-α from LAD2 cells in TLR2-dependent manner. G protein, MAPKs, Ca²⁺/calcineurin/NFAT, PI3K/Akt and TAK pathways were differentially activated by PGN and Pam3CSK4. Release of IL-8 induced by Pam3CSK4 required the involvement of G₀ protein, Erk, Ca²⁺/calcineurin/ NFAT and TAK signaling pathways, but not PI3K/Akt and NF-κB. Meanwhile, G₀ protein was required for the upstream regulation of Erk and Ca²⁺/calcineurin/NFAT signaling cascades activated by Pam3CSK4. In contrast to Pam3CSK4, IL-8 release induced by PGN required the activation of JNK, Erk, PI3K and TAK signaling pathways, but not Ca²⁺ /calcineurin/NFAT and NF-κB. PTX-sensitive Gi/o protein was also involved in PGN induced Erk phosphorylation without influencing IL-8 release. / Pam3CSK4 acted in synergy with anti-IgE to augment the release of IL-8 and TNF-α, but PGN failed to demonstrate similar effect. In contrast, PGN acted in synergy with substance P, while co-stimulation of Pam3CSK4 with substance P failed to demonstrate similar synergism. Erk, Ca²⁺/calcineurin/NFAT and TAK signaling pathways were required for the synergistic action of Pam3CSK4 combined with anti-IgE, while synergistic release of IL-8 induced by PGN and substance P required the activation of Ca²⁺/calcineurin/NFAT, Erk, NF-κB, PI3K, and TAK signaling networks and was enhanced by Ca²⁺/calcineurin/NFAT and NF-κB signaling cascades in LAD2 cells, although NF-κB was not required for IL-8 release induced by PGN or substance P. / These ndings suggest that activation of human mast cells LAD2 can be differentially modified by different TLR2 ligands via distinct signaling pathways. We identify for the first time the involvement of G₀ protein in TLR2 signaling transduction in human mast cells. Further studies of the regulation of mast cells by Toll-like receptors will provide important opportunities for the therapeutic manipulation of infection and allergic diseases. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Yu, Yangyang. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 205-233). / Abstract also in Chinese. / Abstract (English) --- p.i / Abstract (Chinese) --- p.iv / Acknowledgements --- p.vi / Publication --- p.vii / Abbreviations --- p.viii / Contents --- p.x / Chapter 1 --- Introduction --- p.1 / Origin of mast cells --- p.1 / Cytokines and growth factors required for mast cells development --- p.3 / Mediators release from mast cell --- p.7 / Mast cells activation by classical IgE-dependent pathway --- p.13 / Substance P and mast cells --- p.20 / Mast cells in host defense --- p.23 / Toll-like receptors and mast cells --- p.25 / Aims --- p.31 / Chapter 2 --- Materials and Methods --- p.33 / Materials --- p.33 / Methods --- p.42 / LAD2 mast cells culture --- p.42 / Degranulation assay --- p.43 / IL-8 and TNF-α measurement --- p.44 / Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) --- p.44 / Western Blotting --- p.46 / Calcium mobilization assay --- p.47 / Flow cytometry assay --- p.48 / siRNA Transfection --- p.48 / Statistical analysis --- p.49 / Chapter 3 --- Functional Studies of Toll-Like Receptor 2 on Human Mast Cells Activation --- p.51 / Experimental conditions --- p.56 / Results --- p.57 / Discussions --- p.62 / Chapter 4 --- Modulatory Effects of Toll-Like Receptor 2 on Human Mast Cells in Response to Anti-IgE and the Signaling Pathways Involved in the Events --- p.80 / Experimental conditions --- p.92 / Results --- p.93 / Discussions --- p.102 / Chapter 5 --- Modulatory Effects of Toll-Like Receptor 2 on Human Mast Cells Activation in Response to Substance P and Signaling Pathways Involved in the Event --- p.136 / Experimental conditions --- p.140 / Results --- p.141 / Discussions --- p.152 / Chapter 6 --- General Discussion --- p.188 / Chapter 7 --- References --- p.205

研究背景與研究目的 / 細胞衰老是指細胞進入不可逆的永久化的生長停滯狀態。目前，細胞衰老作為重要的抑癌機制受到廣泛認可，对其相關信號通路的研究為腫瘤的靶向治療提供了新的依據和策略。TLX核受體基因属于核受體亞家族2組E成員1，是一種孤兒受體。雞和老鼠TLX基因最初作為果蠅末端/间隙基(tailless) 的同源基因而被發現，而人TLX 基因是在檢索惡性淋巴癌中的抑癌細胞而從人胚胎的腦cDNA文庫中克隆出來的。TLX基因敲除的轉基因老鼠的研究表明TLX基因對維持胚胎腦和成体腦神經幹細胞的分裂增殖起重要作用。最近的研究發現，TLX在臨床神經胶质瘤組織中高表達。並且，在轉基因鼠中，TLX的高表達会引起神經幹細胞的大量增殖而形成腦腫瘤，提示TLX可能參與腦腫瘤的發生和發展。但是，TLX对包括前列腺癌在内的人類惡性腫瘤的發生發展中所起的功能及作用機制尚不清楚。表達譜研究發現，TLX在前列腺細胞中的表達水平高於永生化的正常前列腺上皮細胞的表達，並且，TLX在臨床惡性程度高的前列腺癌中呈高表達趨勢，預示TLX可能參與促進前列腺癌的惡性進展。因此本研究的主要目的是TLX在前列腺癌細胞中的功能研究。 / 研究材料與方法 / 為了研究TLX對前列腺癌細胞生長的影響以及相關機制，本論文主要採用以下方法：1）運用免疫組化的方法檢測TLX在臨床前列腺癌組織中的表達，並應用實時螢光定量PCR方法檢測TLX在永生化的非惡性前列腺上皮細胞以及前列腺癌細胞株中的表達；2）根據不同的p53表達狀態選擇雄激素依賴（LNCaP）和雄激素非依賴（PC-3, DU145）的前列腺癌細胞株，分別采用慢病毒感染和逆轉錄病毒感染的方法建立TLX-敲除和TLX-過表達的細胞株，並研究這些穩轉細胞系離體和在體的生長表型（包括檢測細胞生長，細胞週期，細胞衰老，細胞的遷移和侵染，化療藥物抗性，缺氧耐受性以及體內成瘤能力）；3）採用檢測β-半乳糖苷酶活性的方法檢測TLX穩轉系細胞在衰老因素誘導和非誘導狀態下TLX缺失和高表達對細胞衰老的影響；4）采用免疫印跡（western blot）的方法檢測TLX穩轉系細胞中參與細胞衰老的關鍵蛋白的表達情況；5）利用雙螢光素酶報告基因方法和染色質免疫沉澱技術，研究TLX對靶基因的調控；6）構建TLX缺失變異體（△ZF1 和 △LBD-AF2），在前列腺細胞系和非前列腺細胞系中外源性表達相應的變異體進一步驗證TLX的功能。 / 結果 / 本論文研究結果總結如下：1）TLX在前列腺癌細株中和惡性程度高的前列腺癌組織中高表達；2）在前列腺癌中進行TLX基因敲除能顯著抑制細胞體外和體內的生長並誘導前列腺癌細胞的衰老；3）相反，TLX的過表達能促進前列腺癌細胞體外和體內的惡性生長，包括促進細胞的錨定和非錨定性生長、促進細胞的遷移與侵染、增強細胞缺氧耐受、對化療藥物抗性、以及增強細胞異位移植瘤的成瘤能力；4）TLX 的高表達抑制了前列腺癌細胞衰老，並保護細胞免受多柔比星誘導的細胞衰老以及持續性激活的癌基因H-RAS（H-RAS{U+1D33}¹²{U+2C7D}）誘導的細胞衰老；5）TLX可以結合到p21{U+1D42}{U+1D2C}{U+A7F1}¹/{U+A7F0}{U+1D35}{U+1D3E}¹基因（其後縮寫為p21）的啟動子序列並抑制p21的啟動子的轉錄活性，並且在TLX-過表達細胞中外源性高表達p21能誘導前列腺癌細胞重新進入衰老狀態；6）TLX也能結合到SIRT1基因的啟動子序列並激活SIRT1的轉錄活性，在TLX-過表達細胞中對SIRT1進行基因沉默能誘導這些細胞的再次衰老；7）TLX介導的衰老抑制效應以及對其靶基因的轉錄調控作用需要完整的DNA-結合域以及配體結合域，對TLX兩個區域的缺失變異影響TLX在前列腺細胞和非前列腺細胞中的生理功能及轉錄調控活性。 / 結論 / 本論文的研究結果提示TLX通過抑制前列腺癌細胞的衰老在前列腺癌發生發展過程中起重要作用，並且這種衰老抑制作用是通過介導p21基因的轉錄抑制以及對SIRT1基因的轉錄激活而實現的。此研究首次證實了TLX在前列腺癌中高表達，並且TLX能夠抑制前列腺癌細胞的衰老從而促進前列腺癌的發生發展，提示TLX有可能成為前列腺癌治療潛在的重要靶點。 / Background and aims of the study / Cellular senescence represents an irreversible form of permanent cell-cycle arrest and it acts a key process of tumor suppression, while targeting to pathways involved in this process can provide potential and promising therapeutic strategies to cancer treatments. TLX belongs to the NR2E1 orphan nuclear receptor subfamily. The chicken and mouse TLX genes were initially isolated as a vertebrate homolog to the Drosophila terminal-gap gene tailless (tll), while the human TLX was cloned from a fetal brain cDNA library in a search for putative tumor suppressor genes in lymphoid malignancies. Functional studies in transgenic mouse model of TLX-knockdown show that TLX plays important regulatory roles in the maintenance and self-renewal control of both embryonic and adult neural stem cells. Recent studies of transgenic mice with TLX overexpression combined with its expression studies in human clinical gliomas revealed that TLX is overexpressed in primary human glioblastomas and its dysregulation may contribute to the initiation and development of some brain tumors. However, the exact functional contributions of TLX and the involved mechanism(s) in human malignancies, including prostate cancer, are still far from clear. In an expression profile study, it was demonstrated that TLX exhibited an up-regulated expression pattern in many prostate cancer cell lines and also the high-grade clinical prostate cancer, suggesting that TLX might play a positive regulatory role in the advanced progression of prostate cancer. The overall aim of this study was to elucidate the functional role of TLX in prostate cancer cell growth. / Materials and methods / In order to elucidate the functional roles of TLX in prostate cancer growth and the involved mechanisms, the following experiments were conducted: 1) To investigate and determine the expression pattern of TLX in clinical prostatic tissues by immunohistochemistry, and to survey the expression profile of TLX in a panel of prostatic immortalized epithelial and prostate cancer cell lines by quantitative real-time PCR analysis; 2) To generate stable TLX-knockdown prostate cancer cells by lentiviral transduction and TLX-stable expressing cells by retroviral transduction in both hormone-sensitive (LNCaP) and -insensitive (DU145 and PC-3) prostate cancer lines with different expression status of p53; and to conduct growth phenotype characterization studies (including cell growth, cell cycle, cellular senescence, cell migration and invasion, resistance to chemotherapy drugs, hypoxic cell growth assays, and tumorigenesis) on these TLX-transfectants in vitro and in vivo; 3) To characterize cellular senescence phenotype of TLX-infectants by senescence-associated β-galactosidase (SA-β-Gal) staining method with or without senescence inducers; 4) To investigate the expression status of markers involved in cellular senescence in TLX-infectants by immunoblotting; 5) To demonstrate the transcriptional regulation targets of TLX by dual-luciferase reporter assay and chromatin immunoprecipitation (ChIP) assay; 6) To confirm the cellular function of TLX in prostatic and non-prostatic cells expressing different TLX deletion mutants (△ZF1 and △LBD-AF2). / Results / Results obtained in this study are summarized as follows: 1) TLX displayed an increased expression pattern in many prostate cancer cell lines and also high-grade (Gleason score ≥ 7) prostate cancer tissues; 2) Depletion of TLX mRNA by RNA interference dramatically suppressed in vitro and in vivo tumor cell growth and triggered cellular senescence (SA-β-Gal histochemical marker) in prostate cancer cells; 3) On the contrary, TLX overexpression significantly enhanced multiple advanced malignant growth capacities (including enhanced anchorage-dependent and -independent cell growth, cell migration and invasion, hypoxia adaptation, resistance to chemotherapy drug Doxorubicin as well as in vivo tumorigenicity) in prostate cancer cells; 4) TLX overexpression significantly suppressed cellular senescence and protected cells against doxorubicin-induced or oncogenic H-RAS (H-RAS{U+1D33}¹²{U+2C7D})- induced senescence; 5) TLX could directly bind to p21{U+1D42}{U+1D2C}{U+A7F1}¹/{U+A7F0}{U+1D35}{U+1D3E}¹ gene (hereafter p21) promoter and repress the transcriptional activity of p21 promoter, while ectopic restoration of p21 expression in TLX-overexpressed cells could rescue cellular senescence with enhanced SA-β-Gal staining; 6) protein deacetylase SIRT1 gene was also activated by TLX through its direct transcriptional regulation, while knockdown of SIRT1 in TLX-overexpressed cells could rescue cellular senescence; 7) TLX-induced suppression of cellular senescence and also its direct gene regulation would require an intact DBD and LBD domain, as truncated deletion of DBD or LBD domain could both abolish the cellular function and transcriptional activity of TLX in prostatic and non-prostatic cells. / Conclusions / The results obtained in this study suggested that TLX could play a positive growth regulatory or tumor-promoting role in prostate cancer development by its suppression of cellular senescence and this senescence suppression was mediated via its direct transcriptional regulation of both p21 (repression) and SIRT1 (transactivation) genes. Moreover, this study also showed for the first time that TLX, which was overexpressed in prostate cancer tissues, might function to suppress premature senescence in prostate cancer progression and also targeting to TLX could be a potential therapeutic approach for prostate cancer treatment. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Wu, Dinglan. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 135-151). / Abstract also in Chinese. / Thesis /Assessment Committee --- p.I / ABSTRACT --- p.II / 摘 要 --- p.VI / ACKNOWLEDGEMENT --- p.IX / PUBLICATIONS RELATED TO THIS THESIS --- p.XI / CONTENTS --- p.XII / ABBREVIATION --- p.XV / Chapter CHAPTER 1 --- INTRODUCTION --- p.1 / Chapter 1.1 --- Prostate cancer --- p.2 / Chapter 1.1.1 --- Epidemiology --- p.2 / Chapter 1.1.2 --- Nature history --- p.4 / Chapter 1.1.3 --- Androgen Axis prostate cancer --- p.7 / Chapter 1.1.3.1 --- Androgen receptor --- p.7 / Chapter 1.1.3.2 --- Function of the androgen receptor in prostate cancer --- p.7 / Chapter 1.1.3.3 --- Mechanisms of CRPC progression --- p.8 / Chapter 1.1.3.4 --- Androgen receptor pathway-directed therapies --- p.10 / Chapter 1.1.4 --- Treatment of prostate cancer --- p.11 / Chapter 1.2 --- Cellular senescence --- p.13 / Chapter 1.2.1 --- What is senescence --- p.13 / Chapter 1.2.1.1 --- Replicative cellular senescence --- p.13 / Chapter 1.2.1.2 --- Oncogene induced senescence (OIS) --- p.15 / Chapter 1.2.1.3 --- Tumor suppressor loss-induced senescence --- p.17 / Chapter 1.2.2 --- Establishment of cellular senescence --- p.19 / Chapter 1.2.3 --- The p16/pRb and ARF/p53/p21 pathway of senescence induction --- p.21 / Chapter 1.2.3.1 --- p16/pRb senescence pathway --- p.22 / Chapter 1.2.3.2 --- ARF/p53/p21 senescence pathway --- p.23 / Chapter 1.2.4 --- Markers of senescence --- p.24 / Chapter 1.2.4.1 --- Cell cycle arrest and morphology --- p.24 / Chapter 1.2.4.2 --- Senescence-associated β-galactosidase --- p.25 / Chapter 1.2.4.3 --- p16/pRb and p53/p21 pathways --- p.26 / Chapter 1.2.4.4 --- γ-H2AX staining as a marker for DNA damage --- p.27 / Chapter 1.2.4.5 --- Senescence-associated heterochromatin foci (SAHF) --- p.27 / Chapter 1.2.5 --- Pro-senescence therapy for cancer treatment --- p.29 / Chapter 1.2.5.1 --- Why pro-senescence therapy --- p.29 / Chapter 1.2.5.2 --- Critical factors of pro-senescence therapy --- p.31 / Chapter 1.2.5.3 --- Strategies of senescence induction --- p.32 / Chapter 1.2.5.4 --- Targeting to senescence-associated secretory phenotype (SASP) --- p.38 / Chapter 1.2.6 --- Future direction --- p.40 / Chapter 1.3 --- TLX --- p.41 / Chapter 1.3.1 --- Nuclear receptor --- p.41 / Chapter 1.3.2 --- Identification of tailless/TLX --- p.42 / Chapter 1.3.3 --- Tailless in drosophila --- p.43 / Chapter 1.3.4 --- Functional role of tll/TLX --- p.45 / Chapter 1.3.4.1 --- Role of tll/TLX in brain development --- p.45 / Chapter 1.3.4.2 --- Role of tll/TLX in visual system developments --- p.46 / Chapter 1.3.4.3 --- Role of TLX in neural stem cell self-renewal --- p.47 / Chapter 1.3.5 --- Target genes of TLX --- p.49 / Chapter 1.3.6 --- Transcriptional regulation of tll/TLX --- p.51 / Chapter 1.3.7 --- TLX in cancer --- p.52 / Chapter CHAPTER 2 --- STUDY AIMS --- p.54 / Chapter CHAPTER 3 --- MATERIALS AND METHODS --- p.57 / Chapter 3.1 --- Human prostatic tissues and Immunohistochemistry --- p.58 / Chapter 3.2 --- Cell lines and cell cultures --- p.59 / Chapter 3.3 --- Antibody and reagents --- p.63 / Chapter 3.3.1 --- Generation of rabbit anti-TLX polyclonal antibody --- p.63 / Chapter 3.3.2 --- Commercial antibody --- p.64 / Chapter 3.4 --- RNA isolation and Reverse transcriptional-PCR --- p.65 / Chapter 3.4.1 --- RNA isolation --- p.65 / Chapter 3.4.2 --- Reverse transcription reaction (RT) --- p.66 / Chapter 3.4.3 --- Polymerase Chain Reaction (PCR) --- p.66 / Chapter 3.5 --- Western blotting --- p.68 / Chapter 3.5.1 --- Protein extraction --- p.68 / Chapter 3.5.2 --- Electrophoresis, Protein blotting and Colorimetric detection --- p.69 / Chapter 3.6 --- Plasmids construction --- p.70 / Chapter 3.6.1 --- PCR for sub-cloning --- p.70 / Chapter 3.6.2 --- PCR for mutant generation --- p.71 / Chapter 3.6.3 --- Restriction enzymes digestion and ligation --- p.72 / Chapter 3.7 --- Retroviral, lentiviral transduction and generation of TLX-stable cells --- p.73 / Chapter 3.8 --- RNA interference --- p.75 / Chapter 3.9 --- In vitro cell growth assay --- p.76 / Chapter 3.9.1 --- Cell counting --- p.76 / Chapter 3.9.2 --- MTT assay --- p.76 / Chapter 3.9.3 --- Soft agar assay for anchorage independent growth --- p.77 / Chapter 3.10 --- Cell cycle assay --- p.77 / Chapter 3.11 --- Cell invasion assay --- p.78 / Chapter 3.12 --- In vivo tumor growth assay --- p.78 / Chapter 3.13 --- In vitro and in vivo SA-β-Gal staining --- p.79 / Chapter 3.14 --- In vitro treatment with doxorubicin --- p.80 / Chapter 3.15 --- Transient Transfection and Luciferase Reporter Assay --- p.81 / Chapter 3.16 --- Chromatin immunoprecipitation (ChIP) assay --- p.82 / Chapter 3.16.1 --- Cross-linking and harvesting cells --- p.82 / Chapter 3.16.2 --- Cell lysis --- p.83 / Chapter 3.16.3 --- Sonication --- p.83 / Chapter 3.16.4 --- Immunoprecipitation --- p.83 / Chapter 3.16.5 --- Washing --- p.84 / Chapter 3.16.6 --- Elution --- p.85 / Chapter 3.16.7 --- Reverse cross-linking and DNA purification --- p.85 / Chapter 3.16.8 --- PCR --- p.86 / Chapter 3.17 --- Statistical analysis --- p.86 / Chapter CHAPTER 4 --- RESULTS --- p.87 / Chapter 4.1 --- TLX is up-regulated in prostate carcinoma and prostate cancer cell lines --- p.88 / Chapter 4.2 --- Knockdown of TLX suppresses in vitro cell growth and triggers cellular senescence in prostate cancer cells --- p.93 / Chapter 4.3 --- Knockdown of TLX inhibits in vivo tumor growth and induces cellular senescence of prostate cancer cells --- p.97 / Chapter 4.4 --- Ectopic expression of TLX enhances in vitro cell growth and multiple advanced malignant phenotypes in prostate cancer cells --- p.100 / Chapter 4.5 --- Ectopic expression of TLX suppresses cellular senescence in prostate cancer cells --- p.105 / Chapter 4.6 --- TLX suppresses cellular senescence via its direct transcriptional repression of p21{U+1D42}{U+1D2C}{U+A7F1}¹/{U+A7F0}{U+1D35}{U+1D3E}¹ gene --- p.110 / Chapter 4.7 --- TLX also suppresses cellular senescence via its transcriptional regulation of SIRT1 gene --- p.116 / Chapter CHAPTER 5 --- DISCUSSION --- p.121 / Chapter CHAPTER 6 --- SUMMARY --- p.131 / REFERENCES --- p.135

In a phage binding assay, phage clone (3p5A190) expressing a surrogate mas ligand displayed punctate binding and were internalized in cell expressing native mas and GFP-tagged variants. However, the number of bound and internalized phages in cells expressing mas-GFP was substantially less than the cells expressing mas-(Gly10Ser5)GFP and native mas. In parallel, biotinylation experiment quantitatively showed that the extent of mas-(Gly10Ser 5)-GFP translocation was higher than that of mas-GFP. Consistently, cells expressing mas-(Gly10Ser5)-GFP and native mas showed a rapid and sustained increase of intracellular calcium levels upon MBP7 stimulation. By contrast, cells expressing mas-GFP only response to higher concentration of MBP7 challenge and showed a delayed increase of intracellular calcium level. Moreover, cells expressing native mas had a higher proportion (80%) of cells responsive to MBP7 stimulation; in contrast to only 10∼20% of cells expressing mas fusion proteins. / MBP7-like motif was identified in human facilitative GLUT1 and GLUT7 indicating that mas might interact with glucose transporter (GLUT) and regulate cellular glucose uptake. GLUT4 was found to be expressed endogenously in the CHO cell by RT-PCR, but expression of insulin receptor was not detectable. Although no statistical difference was detected in basal glucose uptake among control cells Vc0M80 and cells with different levels of mas expression, cells expressing mas-(Gly10Ser5)-GFP showed a high glucose uptake in response to insulin. Furthermore, basal 2-DOG uptake in Mc0M80 cells was not affected by pretreatment with various kinase inhibitors or transient expression of Rho variants. By contrast, MBP7 was found to induce a significant elevation of glucose uptake specifically in Mc0M80 cells transiently transfected with GLUT1. / Orphan G protein-coupled receptor (GPCR) mas was initially isolated from a human epidermal carcinoma. Previous study from our lab identified a surrogate ligand---MBP7 (mas binding peptide 7) for mas, and suggested that GFP tagging might affect the receptor activity of mas. In this project, three stable CHO cell lines expressing native mas, mas-GFP and mas-(Gly10Ser 5)-GFP were used to characterize receptor activity of mas. / To summarize, direct GFP tagging at the C-terminus of mas decreased its interactions with ligand and downstream signaling molecules. Partial recovery of mas receptor activity by adding a peptide linker was confirmed by phage binding, membrane fusion protein translocation and calcium response. In addition, mas was possibily coupled with GLUT1 to affect cellular glucose uptake via signaling pathways yet to be fully characterized. / Sun, Jingxin. / Adviser: Cheung Wing Tai. / Source: Dissertation Abstracts International, Volume: 71-01, Section: B, page: 0104. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 150-170). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. Ann Arbor, MI : ProQuest Information and Learning Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese.

by Yam Kwok Fai. / Year shown on spine: 1997. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1996. / Includes bibliographical references (leaves 141-149). / Acknowledgments --- p.i / List of Contents --- p.ii / List of Figures --- p.viii / List of Tables --- p.xii / List of Primers --- p.xiii / Abbreviations --- p.xiv / Chapter Chapter 1 --- Introduction / Chapter 1.1 --- Growth Hormone (GH) --- p.1 / Chapter 1.2 --- Growth Hormone Receptor (GHR) --- p.3 / Chapter 1.2.1 --- Tissue Distribution of GHR --- p.4 / Chapter 1.2.2 --- Biosynthesis and Degradation of GHR --- p.6 / Chapter 1.2.3 --- Regulation of GHR Level --- p.7 / Chapter 1.2.4 --- The Structure of GHR --- p.9 / Chapter 1.2.5 --- The Structure of GHR Gene --- p.13 / Chapter 1.2.6 --- Growth Hormone Binding Protein (GHBP) --- p.14 / Chapter 1.2.7 --- The GH/Prolactin/Cytokine/Erythropoietin Receptor Superfamily --- p.15 / Chapter 1.2.8 --- Proposed Signal Transduction Pathway --- p.17 / Chapter 1.2.9 --- GHR Related Dwarfism --- p.22 / Chapter i). --- Substitution of certain amino acid residues in the extracellular domain --- p.22 / Chapter ii). --- Deletion of the extracellular domain --- p.23 / Chapter a). --- deletion of a small portion of the binding protein / Chapter b). --- deletion of a large portion of the binding protein / Chapter c). --- deletion of a large portion of the binding domain and the whole transmembrane domain / Chapter iii). --- Associated with normal GHBP --- p.24 / Chapter 1.3 --- Objectives of Cloning Vertebrate GHR cDNAs --- p.24 / Chapter Chapter 2 --- General Experimental Methods / Chapter 2.1 --- Preparation of Ribonuclease Free Reagents and Apparatus --- p.26 / Chapter 2.2 --- Isolation of Total RNA --- p.26 / Chapter 2.3 --- Isolation of mRNA --- p.26 / Chapter a). --- directly from tissue / Chapter b). --- from isolated total RNA / Chapter 2.4 --- Spectrophotometric Quantification and Qualification of DNA and RNA --- p.29 / Chapter 2.5 --- First Strand cDNA Synthesis --- p.29 / Chapter 2.6 --- Polymerase Chain Reaction (PCR) --- p.30 / Chapter 2.7 --- Agarose Gel Electrophoresis --- p.31 / Chapter 2.8 --- Formaldehyde Agarose Gel Electrophoresis of RNA --- p.31 / Chapter 2.9 --- Capillary Transfer of DNA/RNA to a Nylon Membrane (Southern/Northern Blotting) --- p.32 / Chapter a). --- DNA denaturing / Chapter b). --- Capillary transfer / Chapter 2.10 --- DNA Radiolabelling --- p.33 / Chapter a). --- By random primer translation / Chapter b). --- By nick translation / Chapter 2.11 --- Spuncolumn Chromatography --- p.34 / Chapter 2.12 --- Hybridization of Southern/Northern Blot --- p.35 / Chapter 2.13 --- Autoradiography --- p.35 / Chapter 2.14 --- Linearization and Dephosphorylation of Plasmid DNA --- p.36 / Chapter 2.15 --- Restriction Digestion of DNA --- p.36 / Chapter 2.16 --- Purification of DNA from Agarose Gel using GENECLEAN® Kit --- p.36 / Chapter 2.17 --- 3' End Modification of PCR Amplified DNA --- p.37 / Chapter 2.18 --- Ligation of DNA Fragments to Linearized Vector --- p.37 / Chapter 2.19 --- Preparation of Escherichia coli Competent Cells --- p.38 / Chapter 2.20 --- Transformation of the Escherichia coli Strain DH5a --- p.38 / Chapter 2.21 --- Minipreparation of Plasmid DNA --- p.39 / Chapter 2.22 --- DNA Purification by Phenol/Chloroform Extraction --- p.39 / Chapter 2.23 --- Ethanol Precipitation of DNA and RNA --- p.40 / Chapter 2.24 --- Preparation of Plasmid DNA using Wizard´ёØ Minipreps DNA Purification Kit from Promega --- p.40 / Chapter 2.25 --- Preparation of Plasmid DNA using QIAGEN-tip100 --- p.41 / Chapter 2.26 --- DNA Sequencing --- p.42 / Chapter 2.26.1 --- DNA Sequencing Reaction / Chapter a). --- T7 sequencing / Chapter b). --- PCR sequencing / Chapter 2.26.2 --- DNA Sequencing Electrophoresis --- p.44 / Chapter i). --- Preparation of 8% polyacrylamide gel solution / Chapter ii). --- Casting the gel / Chapter iii). --- Electrophoresis / Chapter Chapter 3 --- Molecular Cloning of Golden Hamster (Mesocricetus auratus) GHR cDNA / Chapter 3.1 --- Introduction --- p.46 / Chapter 3.2 --- Experimental Methods / Chapter 3.2.1 --- Animals and Tissues --- p.47 / Chapter 3.2.2 --- PCR Cloning of GHR cDNA Fragments in the Cytoplasmic Domain --- p.47 / Chapter 3.2.2.1 --- Primer design and PCR strategy --- p.47 / Chapter 3.2.2.2 --- PCR studies on the hamster liver and kidney first strand cDNA --- p.49 / Chapter 3.2.2.3 --- Southern analysis of the PCR products --- p.50 / Chapter 3.2.2.4 --- Subcloning and sequencing of PCR amplified cDNA fragments --- p.50 / Chapter 3.2.3 --- Screening of a Hamster Liver cDNA Library --- p.51 / Chapter 3.2.3.1 --- Preparation of the plating bacteria --- p.51 / Chapter 3.2.3.2 --- Phage titering of the λ ZAP library --- p.51 / Chapter 3.2.3.3 --- Primary screening of the amplified hamster liver cDNA library --- p.52 / Chapter 3.2.3.4 --- Plaque uplifting and hybridization with hamster GHR cDNA fragment --- p.52 / Chapter 3.2.3.5 --- Purification of putative clones from primary screening --- p.53 / Chapter 3.2.3.6 --- Checking the size of the DNA insert --- p.53 / Chapter 3.2.3.7 --- In vitro excision to release phagemid from the phage vector --- p.54 / Chapter 3.2.3.8 --- Plasmid minipreparation of the putative clones --- p.56 / Chapter 3.2.3.9 --- Nucleotide sequencing of the DNA inserts of different clones --- p.56 / Chapter 3.2.4 --- Tissue Distribution of GHR in Hamster Tissues and the Relative Expression Level of GHR mRNAin these tissues --- p.58 / Chapter 3.2.5 --- Cloning of the Full-length GHR cDNA into a Mammalian Vector --- p.59 / Chapter 3.2.5.1 --- PCR amplification of the full-length hamster GHR cDNA --- p.59 / Chapter 3.2.5.2 --- Preparation of the hamster GHR cDNA insert for ligation --- p.60 / Chapter 3.2.5.3 --- Linearization of pRc/CMV expression vector --- p.60 / Chapter 3.2.5.4 --- Ligation of the linearized expression vector with the full-length hamster GHR cDNA --- p.61 / Chapter 3.3 --- Results / Chapter 3.3.1 --- PCR Amplification of Hamster GHR cDNA Fragments --- p.61 / Chapter 3.3.1.1 --- RT-PCR --- p.61 / Chapter 3.3.1.2 --- Southern blot analysis --- p.62 / Chapter 3.3.1.3 --- Subcloning and nucleotide sequencing of PCR amplified hamster GHR cDNA fragments --- p.64 / Chapter 3.3.2 --- Screening of an Amplified λZAP Hamster Liver cDNA Library --- p.70 / Chapter 3.3.2.1 --- Preparation of the cDNA probe and phage titering --- p.70 / Chapter 3.3.2.2 --- Screening of the cDNA library --- p.70 / Chapter 3.3.2.3 --- PCR study of the 5' and 3' regions of the DNA insert of the clones selected for secondary screening --- p.72 / Chapter 3.2.3.4 --- Nucleotide sequencing of the full-length hamster GHR cDNA --- p.73 / Chapter 3.2.3.5 --- Tissue distribution of GHR in hamster and the relative expression level of the GHR mRNA in these tissues --- p.73 / Chapter 3.2.3.6 --- Cloning of the full-length hamster GHR cDNA into a mammalian expression vector --- p.79 / Chapter 3.4 --- Discussion / Chapter 3.4.1 --- Cloning of the Full-length hamster GHR cDNA --- p.81 / Chapter 3.4.2 --- Comparison of the Nucleotide and the Predicted Amino Acid Sequences of the Hamster GHR with other Cloned GHRs --- p.82 / Chapter 3.4.3 --- Tissue Distribution of GHR in Hamster and the Relative Expression Level of the GHR mRNA in these Tissues --- p.89 / Chapter 3.4.4 --- Further Studies on Hamster GHR --- p.90 / Chapter Chapter 4 --- Molecular Cloning of Chinese Bullfrog (Rana tigria rigulosa) GHR cDNA from Adult Frog Liver / Chapter 4.1 --- Introduction --- p.92 / Chapter 4.2 --- Experimental Methods / Chapter 4.2.1 --- Animal and Tissues --- p.93 / Chapter 4.2.2 --- Cloning of the Cytoplasmic Domain of Frog GHR cDNA by PCR --- p.93 / Chapter 4.2.2.1 --- RT-PCR --- p.93 / Chapter 4.2.2.2 --- Southern blot analysis of PCR amplified products --- p.95 / Chapter 4.2.2.3 --- Subcloning and sequencing of PCR amplified DNA fragments --- p.95 / Chapter 4.2.2.4 --- Restriction analysis of GHR cDNA fragment between GHR p1 and GHR p2 --- p.95 / Chapter 4.2.2.5 --- PCR cloning of other portions of frog GHR cDNA --- p.96 / Chapter 4.2.2.6 --- Subcloning and sequencing of PCR amplified GHR cDNA fragment using primers other than GHR p1 and GHR p2 --- p.97 / Chapter 4.3 --- Results / Chapter 4.3.1 --- Cloning of the Intracellular Domain of Frog GHR cDNA by RT-PCR --- p.97 / Chapter 4.3.1.1 --- RT-PCR --- p.97 / Chapter 4.3.1.2 --- Southern blot analysis --- p.98 / Chapter 4.3.1.3 --- Subcloning and sequencing of PCR amplified DNA fragments --- p.98 / Chapter 4.3.1.4 --- Restriction enzyme analysis of GHR cDNA fragments --- p.102 / Chapter 4.3.1.5 --- PCR cloning of other portions of frog GHR cDNA --- p.103 / Chapter 4.3.1.6 --- Subcloning and sequencing of PCR products from other portions of frog GHR cDNA --- p.103 / Chapter 4.4 --- Discussion / Chapter 4.4.1 --- Cloning of the Full-length frog GHR cDNA --- p.109 / Chapter 4.4.2 --- Further Studies on Frog GHR --- p.117 / Chapter Chapter 5 --- Attempts on the Molecular Cloning of Teleost GHR cDNA / Chapter 5.1 --- Introduction --- p.119 / Chapter 5.2 --- Experimental Methods / Chapter 5.2.1 --- Animals and Tissues --- p.120 / Chapter 5.2.2 --- PCR Cloning of Teleost GHR cDNA fragments --- p.120 / Chapter 5.2.2.1 --- Design of PCR primers --- p.120 / Chapter 5.2.2.2 --- Preparation of mRNA and synthesis of first strand cDNA --- p.122 / Chapter 5.2.2.3 --- PCR studies on dace and snakehead fish liver first strand cDNA --- p.122 / Chapter 5.2.2.3.1 --- PCR studies on dace liver first strand cDNA --- p.122 / Chapter 5.2.2.3.2 --- PCR studies on snakehead fish liver first strand cDNA --- p.122 / Chapter 5.2.3 --- "Northern Analysis on Dace, Snakehead fish and Eel mRNA" --- p.123 / Chapter 5.3 --- Results / Chapter 5.3.1 --- Molecular Studies on Dace GHR cDNA --- p.123 / Chapter 5.3.1.1 --- PCR studies on dace first strand cDNA --- p.123 / Chapter 5.3.2 --- PCR Studies on Teleost First Strand cDNA --- p.128 / Chapter 5.3.3 --- Northern Analysis on Teleost mRNA --- p.128 / Chapter 5.4 --- Discussion --- p.130 / Chapter 5.4.1 --- PCR Studies on Teleost GHR cDNA --- p.130 / Chapter 5.4.2 --- Northern Analysis on Teleost mRNA --- p.131 / Chapter Chapter 6 --- General Discussion / Chapter 6.1 --- Achievement of this Project --- p.134 / Chapter 6.1.1 --- Hamster GHR --- p.134 / Chapter 6.1.2 --- Frog GHR --- p.135 / Chapter 6.1.3 --- Teleost GHR --- p.136 / Chapter 6.2 --- Postulation on Cloned GHRs at the Molecular Level --- p.136 / Bibliography --- p.141 / Appendices --- p.150

by Simon Chan Siu Hoi. / Spine title varies. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1997. / Includes bibliographical references (leaves 130-148). / Acknowledgments --- p.i / Table of Contents --- p.ii / List of Abbreviations --- p.ix / List of Figures --- p.xiii / List of Tables --- p.xvi / Page / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Growth Hormone --- p.1 / Chapter 1.2 --- Growth Hormone Receptor --- p.3 / Chapter 1.2.1 --- Cytokine/Hematopoietin Receptor Superfamily --- p.3 / Chapter 1.2.2 --- Tissue Distribution of GHR --- p.6 / Chapter 1.2.3 --- Biosynthesis and Degradation of GHR --- p.7 / Chapter 1.2.4 --- Regulation of GHR Level --- p.8 / Chapter 1.2.5 --- The GHR Protein --- p.10 / Chapter 1.2.6 --- The GHR Gene --- p.15 / Chapter 1.2.7 --- GHR Dimerization --- p.16 / Chapter 1.2.8 --- Mechanism of Signaling by GHR --- p.19 / Chapter 1.2.9 --- GH Binding Protein --- p.21 / Chapter 1.2.10 --- GHR Related Dwarfism --- p.23 / Chapter 1.3 --- Objectives of the Present Investigation --- p.25 / Chapter Chapter 2 --- Materials and Methods --- p.27 / Chapter 2.1 --- Fish Growth Hormone Radioactive Labeling --- p.27 / Chapter 2.1.1 --- Preparation of Iodogen-Coated Tubes --- p.27 / Chapter 2.1.2 --- Packing of the Sephadex G-75 Column --- p.28 / Chapter 2.1.3 --- Iodination of brGH and Purification of the Iodinated brGH --- p.28 / Chapter 2.1.4 --- Determination of the Specific Radioactivity and Percentage of 125I Incorporation --- p.29 / Chapter 2.1.5 --- Reagents and Buffers Used --- p.30 / Chapter 2.2 --- Integrity of 125I-brGH --- p.30 / Chapter 2.2.1 --- HPLC of brGH --- p.31 / Chapter 2.2.2 --- HPLC of 125I-brGH after Iodination --- p.31 / Chapter 2.2.3 --- HPLC of 125I-brGH after Receptor Binding --- p.31 / Chapter 2.3 --- Preparation of Membranes from Fish Tissues --- p.32 / Chapter 2.3.1 --- Preparation of Snakehead Fish Liver Membranes --- p.32 / Chapter 2.3.2 --- Reagents and Buffers Used --- p.33 / Chapter 2.4 --- Protein Determination of Membrane Preparations --- p.34 / Chapter 2.4.1 --- The BCA Protein Reaction Scheme --- p.34 / Chapter 2.4.2 --- BCA Protein Determination Protocol --- p.34 / Chapter 2.5 --- Receptor Binding Studies --- p.35 / Chapter 2.5.1 --- Association and Dissociation Studies --- p.36 / Chapter 2.5.2 --- pH Dependence Study --- p.36 / Chapter 2.5.3 --- Membrane Protein Dependence Study --- p.37 / Chapter 2.5.4 --- Ca2+ Dependence Study --- p.37 / Chapter 2.5.5 --- Tissue Distribution Study --- p.37 / Chapter 2.5.6 --- Displacement and Specificity Studies --- p.38 / Chapter 2.5.7 --- Dithiothreitol (DTT) Dependence Study --- p.39 / Chapter 2.5.8 --- p-Chloromercuribenzene Sulfonate (PCMBS) Pretreatment: Dose Dependence Study --- p.39 / Chapter 2.5.9 --- Scatchard Analysis of the PCMBS Pretreated and Control Snakehead Fish Liver Membranes --- p.40 / Chapter 2.5.10 --- Reversibility of the PCMBS Effect --- p.40 / Chapter 2.5.11 --- Reagents and Buffers Used --- p.41 / Chapter 2.6 --- Crosslinking Studies --- p.41 / Chapter 2.6.1 --- Crosslinking Performed on Snakehead Fish Liver Membranes --- p.41 / Chapter 2.6.2 --- Crosslinking Performed on Solubilized Snakehead Fish Liver Membranes --- p.42 / Chapter 2.6.3 --- Gel Filtration Chromatography of the Crosslinked Comp)lexes --- p.43 / Chapter 2.6.4 --- Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis (SDS-PAGE) of the Crosslinked Complexes --- p.43 / Chapter 2.6.5 --- Reagents and Buffers Used --- p.45 / Chapter 2.7 --- Western Blot Analysis of Snakehead Fish Liver GHR --- p.46 / Chapter 2.7.1 --- SDS-PAGE of Snakehead Fish Liver Membranes --- p.46 / Chapter 2.7.2 --- Transfer of Proteins onto Polyvinylidene Fluoride (PVDF) Membrane --- p.46 / Chapter 2.7.3 --- Antibody Development of PVDF Membrane --- p.47 / Chapter 2.7.4 --- Reagents and Buffers Used --- p.48 / Chapter 2.8 --- Solubilization of Snakehead Fish Liver Membranes and Solubilized Receptor Binding Studies --- p.48 / Chapter 2.8.1 --- Solubilization of Snakehead Fish Liver Membranes --- p.49 / Chapter 2.8.2 --- Solubilized Receptor Binding Assay --- p.49 / Chapter 2.8.3 --- "Solubilization of Snakehead Fish Liver Membranes: Detergent Concentration, pH, Temperature and Time Dependence" --- p.50 / Chapter 2.8.4 --- Solubilized Receptor Binding Study: Interference of Detergent --- p.50 / Chapter 2.8.5 --- Reagents and Buffers Used --- p.51 / Chapter 2.9 --- Purification of Snakehead Fish Liver GHR by Affinity Chromatography --- p.51 / Chapter 2.9.1 --- Affinity Column Preparation --- p.52 / Chapter 2.9.2 --- Snakehead Fish Liver GHR Purification --- p.52 / Chapter 2.9.3 --- Reagents and Buffers Used --- p.53 / Chapter Chapter 3 --- Results: fGH Labeling and Integrity Determination --- p.54 / Chapter 3.1 --- Introduction --- p.54 / Chapter 3.2 --- Experimental Results --- p.55 / Chapter 3.2.1 --- Iodination of fGH --- p.55 / Chapter 3.2.2 --- Integrity of 125I-fGH --- p.55 / Chapter 3.3 --- Discussion --- p.61 / Chapter Chapter 4 --- Results: Membrane Receptor Binding Studies --- p.62 / Chapter 4.1 --- Introduction --- p.62 / Chapter 4.2 --- Experimental Results --- p.63 / Chapter 4.2.1 --- Optimal Conditions for Snakehead Fish Liver Membrane GHR Binding --- p.64 / Chapter 4.2.1.1 --- Association and Dissociation Studies --- p.64 / Chapter 4.2.1.2 --- pH Dependence Study --- p.67 / Chapter 4.2.1.3 --- Membrane Protein Dependence Study --- p.70 / Chapter 4.2.1.4 --- Ca2+ Dependence Study --- p.73 / Chapter 4.2.2 --- Localization and Specificity of Snakehead Fish GHR --- p.76 / Chapter 4.2.2.1 --- Tissue Distribution Study --- p.76 / Chapter 4.2.2.2 --- Displacement and Specificity Studies --- p.78 / Chapter 4.2.3 --- Effects of Sulfhydryl Group Reducing and Oxidizing Agents on GHR Binding --- p.81 / Chapter 4.2.3.1 --- Effect of DTT: Concentration Dependence Study --- p.81 / Chapter 4.2.3.2 --- Effect of PCMBS: Concentration Dependence Study --- p.84 / Chapter 4.2.3.3 --- Scatchard Analysis of Control and PCMBS- pretreated Membranes --- p.86 / Chapter 4.2.3.4 --- Reversibility of the PCMBS Effect --- p.88 / Chapter 4.3 --- Discussion --- p.90 / Chapter 4.3.1 --- Optimal Conditions for Snakehead Fish Liver Membrane GHR Binding --- p.90 / Chapter 4.3.2 --- Localization and Specificity of Snakehead Fish GHR --- p.93 / Chapter 4.3.3 --- Effects of Sulfhydryl Group Reducing and Oxidizing Agents on GHR Binding --- p.96 / Chapter Chapter 5 --- Results: Crosslinking and Western Blot Analysis --- p.101 / Chapter 5.1 --- Introduction --- p.101 / Chapter 5.1.1 --- Crosslinking Studies --- p.101 / Chapter 5.1.2 --- Western Blot Analysis --- p.103 / Chapter 5.2 --- Experimental Results --- p.104 / Chapter 5.2.1 --- Crosslinking Studies --- p.104 / Chapter 5.2.2 --- Western Blot Analysis --- p.105 / Chapter 5.3 --- Discussion --- p.112 / Chapter Chapter 6 --- Results: Affinity Purification of Snakehead Fish Liver GHR --- p.115 / Chapter 6.1 --- Introduction --- p.115 / Chapter 6.1.1 --- Membrane Solubilization and Solubilized GHR Binding Studies --- p.115 / Chapter 6.1.2 --- Affinity Purification of Solubilized Snakehead Fish Liver GHR --- p.116 / Chapter 6.2 --- Exp erimental Results --- p.117 / Chapter 6.2.1 --- Solubilization of Snakehead Fish Liver Membranes --- p.117 / Chapter 6.2.2 --- Interference of Detergents in the Solubilized Receptor Binding Assay --- p.118 / Chapter 6.2.3 --- Affinity Purification of Solubilized Snakehead Fish Liver GHR --- p.120 / Chapter 6.3 --- Discussion --- p.122 / Chapter Chapter 7 --- General Discussion --- p.125 / References --- p.130

Motivation has been defined as a set of processes which enables organisms to overcome obstacles by energizing behavior in the pursuit of a goal. There are several important observations about motivated behavior which provide insight into the neural mechanisms underlying goal-directed motivation. First, motivation serves two important functions, as it both energizes behavior and also directs it toward or away from specific stimuli. Many of the behavioral tasks used to assay motivation in laboratory rodents do not specifically aim to measure these two distinct aspects of motivation. A second feature of goal-directed motivation is that it is sensitive to both costs and benefits of a given situation, enabling animals to make cost-benefit decisions. Again, many of the behavioral tasks which study cost-benefit decision making do not specifically aim to independently measure the impact of cost manipulations and benefit manipulations in an isolated manner. Here, I first develop behavioral measures which aim to specifically dissociate activational and directional effects of motivation. By characterizing a novel behavioral measure known as a Progressive Hold Down (Ph.D.) task, and using this task in parallel with a more traditionally used Progressive Ratio (PR) task, I show that methamphetamine robustly enhances activational effects of motivation, leading to increased response rates in both the Ph.D. and PR task, but mice are not more goal-directed in the Ph.D. task. I next develop and characterize two novel behavioral assays which are specifically used to examine effort and value contributions to cost-benefit decision making. The Concurrent Effort Choice (CEC) task measures how changes in effort levels impact decision making whereas the Concurrent Value Choice (CVC) task measure how changes in reward value impact decision making. Using these novel assays to examine specific processes important for goal-directed motivation, I carefully examine the role of manipulation of the Dopamine D2 receptor (D2R) in a mouse model which over-expresses the D2R within the striatum (D2R-OE), and the role of pharmacological manipulation of the Serotonin 2C receptor (5-HT2CR) with the functionally selective ligand SB242084. Whereas D2R-OE specifically impacts sensitivity to changes in effort levels which decrease overall levels of goal-directed motivation, selective modulation of the 5-HT2CR via treatment with SB242084 increases response vigor through enhanced dopamine release in the dorsomedial striatum, but this increase in response vigor does not alter sensitivity to effort or value changes when working for rewards. Together, these studies demonstrate the benefits of developing a more nuanced understanding of how specific manipulations impact motivated behavior by examining the specific underlying processes being altered.

Ischaemic stroke has become one of the leading causes of death and disability in the world. Protease activated receptors (PARs, PAR-1 to PAR-4) belong to G protein coupled receptors that can be self-activated by tethered ligands (TL) revealed through proteolytic cleavage. Based on these TL, many activating peptides (APs) and antagonists have been synthesized to investigate PARs actions. / In the present study, the roles of PARs were examined in two models of ischaemic stroke. For the in vivo model, transient middle cerebral artery occlusion (tMCAO) was performed to establish cerebral ischaemia in rats. For the in vitro model, oxygen and glucose deprivation (OGD) was used to mimic an ischaemia insult in primary cultured rat embryonic cortical neurones. / Western blot studies showed that expressions of PAR-1 and PAR-2 were increased in the rat ischaemic brain cortex, whereas PAR-1 was reduced in the rat cortical neurones subjected to OGD. Pretreatments of PAR-1 AP (SFLLRN-NH₂) and PAR-2 AP (SLIGRL-NH₂) produced significant protection against ischaemia-induced damage. Pretreatment of PAR-3 AP (SFNGGP-NH₂) only improved ischaemic symptoms in in vivo but not in in vitro model. When treated after ischaemia, only PAR-1 AP produced significant reductions on ischaemia-induced damage. Protective actions of PAR-1 and PAR-2 APs were inhibited by PAR-1 antagonist (BMS-200261) and PAR-2 antagonist (ENMD-1068) respectively, but PAR-1 antagonist did not affect posttreatment effects of PAR-1 AP in in vitro model. Pre- and posttreatments of thrombin, and pretreatment of trypsin also protected ischaemia-induced damage in the two models. / PAR-1 AP produced marked increase in the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and ratio of bcl-2/bax, but reduced contents of reactive oxygen species (ROS), nitric oxide (NO) and malondialdehyde (MDA) in both ipsilateral ischaemic brain cortices and in rat cortical neurones subjected to OGD. In the in vitro model, PAR-1 AP greatly decreased caspase-3 activity and TUNEL positive cells, while markedly increased mitochondrial membrane potential (MMP). All these protective actions were inhibited by its antagonist, which suggests it was mediated via activation of PAR-1. / In MCA isolated from normal and ischameic rats, PAR-2 AP and trypsin produced vasodilatation while PAR-3 AP elicited vasoconstriction. However, another PAR-3 AP had no effect in the two types of MCA. A high concentration of PAR-1 AP relaxed MCA isolated form ischaemic rats, and it was not inhibited by a PAR-1 antagonist. The vasodilator action of PAR-2 AP was inhibited by one of two PAR-2 antagonists tested. The vasodilator actions induced by PAR-1 and PAR-2 APs involved NO production since L-NAME was effective in inhibiting their actions. / In conclusion, PAR-1 AP was found to be the most efficacious in protecting the brain from ischaemia-induced damage when administered either before or after ischaemia insults. The protective actions were likely to be attributed to its anti-oxidant properties in the ischaemic brain that reduced apoptosis of brain cells. Therefore, PAR-1 was identified as a promising target for development of novel prophylactic and therapeutic treatments of ischaemic brain disease. / 缺血性腦中風已經成為全世界導致死亡和殘疾的最主要的疾病之一。蛋白酶激活受體（PARs, PAR-1 to PAR-4）屬於G蛋白偶聯受體並且可以通過蛋白水解生成系鎖配體（TL）從而作用於受體本身而激活信號通路。根據TL的序列已經合成了很多激活肽和拮抗劑，它們可以作為有價值的工具藥進行PAR的作用研究。 / 當前，PAR的作用在兩個缺血性腦中風模型中進行研究。體內模型是通過大鼠大腦中動脈阻塞手術而建立；體外模型是通過對大鼠胚胎大腦皮層神經元進行氧糖剝奪模擬缺血性損傷。 / 蛋白質印跡法的實驗表明PAR-1和PAR-2的表達在缺血側大腦皮層中有所增多，而PAR-1在氧糖剝奪的大鼠皮層神經元中表達卻有所降低。預處理PAR-1（SFLLRN-NH₂）和PAR-2（SLIGRL-NH₂）的激活肽顯著改善了缺血導致的損傷。預處理PAR-3激活肽（SFNGGP-NH₂）僅僅改善了體內缺血症狀，卻對體外缺血模型沒有效果。然而，當這些激活肽在缺血后給予的時候，只有PAR-1的激活肽顯著改善了缺血損傷。PAR-1的拮抗劑（BMS-200261）和PAR-2的拮抗劑（ENMD-1068）抑制了PAR-1和PAR-2激活肽的保護作用，但是體外實驗後處理PAR-1激活肽的保護作用卻未收影響。預處理及後處理凝血酶，預處理胰酶都在這兩個模型中顯示出保護缺血性損傷的作用。 / PAR-1激活肽在缺血同側大腦皮層以及經受氧糖剝奪的大鼠皮層神經元中，顯著提高了超氧化物歧化酶（SOD）、過氧化氫酶（CAT）、谷胱甘肽過氧化物酶（GSH-Px）的活力以及bcl-2/bax的比例，同時顯著降低了活性氧自由基（ROS）、一氧化氮（NO）以及丙二醛（MDA）的含量。在體外模型中，PAR-1激活肽還顯著降低了caspase-3的活力以及TUNEL陽性細胞的比例，同時顯著提高了線粒體膜電位（MMP）。所有這些作用都可以被拮抗劑抑制，說明PAR-1激活肽的保護作用是通過激活PAR-1介導的。 / 不管是從正常還是缺血的大鼠中分離出來的大腦中動脈，PAR-2激活肽和胰酶都可以使之舒張，PAR-3激活肽卻對其有收縮作用。然而，另外一種PAR-3激活肽卻未顯現出對血管活性的影響。高劑量的PAR-1激活肽只可以在分離于缺血大鼠的大腦中動脈中引起舒張，但此作用不能被其拮抗劑所抑制。PAR-2激活肽導致的血管舒張只可以被檢測的兩個拮抗劑中的其中一個所抑制。PAR-1和PAR-2激活肽引起的血管舒張與NO的產生有關，因為L-NAME可以有效抑制它們的作用。 / 總之，不管是預處理還是後處理的給藥方式，PAR-1的激活肽在保護大腦的缺血性損傷中都是最有效果的。保護作用可能可以歸因于其抗氧化以及抗凋亡的特性。所以，PAR-1是研究防治缺血性腦疾病的發展中富有希望的一個靶點。 / Zhen, Xia. / Thesis Ph.D. Chinese University of Hong Kong 2014. / Includes bibliographical references (leaves 194-206). / Abstracts also in Chinese. / Title from PDF title page (viewed on 11, October, 2016). / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only.

Noradrenergic signaling has important functions in the central nervous system (CNS) with respect to emotion, learning and memory. Activation of β- adrenergic receptors (β ARs) stimulates protein kinase A via Gs-protein, adenylyl cyclase, and cAMP. Synaptic β←2 -adrenergic receptors, targets of the neurotransmitter norephinephrin, are associated with the GluA1 subunit of AMPA-type glutamate receptors, which mediate most excitatory synaptic transmission in mammalian CNS. PKA-mediated phosphorylation of GluA1 on Ser845 is important for GluA1 surface expression, activity induced postsynaptic accumulation, and synaptic plasticity. Postsynaptic localization of PKA is mediated by a major scaffolding protein `A kinase anchor protein 5 (AKAP5)'. AKAP5 associates with AMPA receptors via SAP97 and PSD95. We have two strains of AKAP5 mutant mice: AKAP5 knockout and AKAP5 D36. AKAP5 KO mice have a complete loss of AKAP5 gene expression. D36 mice miss the last 36 residues (PKA binding site) of AKAP5 but without affecting other interactions. These mutant mice provide us with appropriate in vivo models for studying the functional roles of AKAP5. We compared the functional and physical association of β2AR and AMPA receptors among wild type, AKAP5 KO, and AKAP5 D36 mice. Although AKAP5 was not necessary for the assembly of the β2AR / GluA1 complex, we found that AKAP5 anchored PKA activity was required for full β2AR stimulation-induced GluA1 Ser845 phosphorylation. Recording and analysis of field EPSPs (fEPSPs) of CA1 pyramidal neurons with brief bath perfusion of the β2AR agonist isoproterenol indicated a role of AKAP5 anchored PKA in the regulation of postsynaptic AMPAR responses by norephinephrin. Moreover, we observed a delayed extinction of contextual fear memory in AKAP5 D36 mice, which suggests the involvement of AKAP5 anchored PKA in memory formation and modification.