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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Internalization of trichosanthin initiating cellular signal transduction involved in its cytotoxicity and antiviral mechanism. / CUHK electronic theses & dissertations collection

January 2003 (has links)
Huang Hai. / "May 2003." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (p. (158-183). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.
2

The simultaneous measurement of nucleotide-stimulated cytosolic calcium signaling and anion secretion in cultured equine sweat gland epithelium.

January 2000 (has links)
Wong Hau Yan Connie. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves 86-95). / Abstracts in English and Chinese. / Abstract --- p.ii / Acknowledgements --- p.ix / Contents --- p.x / List of Figures --- p.xiii / List of Tables --- p.xv / Abbreviations --- p.xvi / Chapter Chapter 1: --- Introduction / Chapter 1.1 --- Role of extracellular nucleotides in equine sweat gland epithelial cells --- p.1 / Chapter 1.2 --- Subdivision of P1 and P2 purinoceptor --- p.4 / Chapter 1.3 --- General properties of P2 purinoceptor --- p.5 / Chapter 1.3.1 --- P2X purinoceptor family --- p.5 / Chapter 1.3.2 --- P2Y purinoceptor family --- p.8 / Chapter 1.4 --- The diversity of P2Y purinoceptor --- p.10 / Chapter 1.4.1 --- P2Y1 receptor --- p.10 / Chapter 1.4.2 --- P2Y2 receptor --- p.10 / Chapter 1.4.3 --- P2Y4 receptor --- p.10 / Chapter 1.4.4 --- P2Y6 receptor --- p.10 / Chapter 1.4.5 --- P2Y11 receptor --- p.11 / Chapter 1.5 --- The importance of calcium --- p.13 / Chapter 1.6 --- General aspects of calcium signaling --- p.14 / Chapter 1.7 --- Calcium release from the intracellular calcium stores --- p.15 / Chapter 1.7.1 --- Metabolism of inositol phosphates --- p.15 / Chapter 1.7.2 --- Ca2+ release from the internal calcium store --- p.15 / Chapter 1.8 --- Store-operated calcium channels (SOCC) or Capacitative calcium entry (CCE) --- p.18 / Chapter 1.8.1 --- The nature of the signal for CCE --- p.18 / Chapter 1.8.1.1 --- Conformational coupling --- p.18 / Chapter 1.8.1.2 --- Diffusible messenger --- p.21 / Chapter 1.9 --- Mechanism of intracellular calcium measurement --- p.25 / Chapter 1.10 --- Background of E92/3 cell line --- p.28 / Chapter Chapter 2: --- Materials and methods --- p.29 / Chapter 2.1 --- Cell culture --- p.29 / Chapter 2.2 --- Preparation of the simultaneous measurement --- p.31 / Chapter 2.2.1 --- Cell seeding --- p.31 / Chapter 2.2.2 --- Dye loading --- p.33 / Chapter 2.3 --- The setup of simultaneous measurement --- p.36 / Chapter 2.4 --- Statistical analysis --- p.40 / Chapter Chapter 3: --- Results --- p.41 / Chapter 3.1 --- Major domain of Ca2+ influx is from the basolateral side --- p.41 / Chapter 3.1.1 --- Effect of store depletion by apical ATP --- p.41 / Chapter 3.1.2 --- Effect of store depletion by basolateral ATP --- p.43 / Chapter 3.1.3 --- Effect of store depletion by thapsigargin --- p.47 / Chapter 3.2 --- Differential effect of apical and basolateral nucleotides on [Ca2+]i and Isc --- p.51 / Chapter 3.2.1 --- Basolateral ATP activates an increase in [Ca2+]i but not Isc --- p.51 / Chapter 3.2.2 --- Apical and basolateral ATP activated distinct but partially overlapped internal Ca2+ pool --- p.51 / Chapter 3.2.3 --- "Dose-dependent effect of apical or basolateral ATP, UDP and UTP on [Ca2+]i i and Isc" --- p.54 / Chapter 3.3 --- P2Y receptors subtypes on the basolateral membrane --- p.60 / Chapter 3.3.1 --- "Possible involvement of P2X, P2Y1 and P2Y11 purinoceptors on the basolateral membrane" --- p.60 / Chapter 3.3.2 --- "Cross-desensitization of experiments of UTP, ATP and UDP" --- p.60 / Chapter 3.4 --- The ATP-activated Ca2+ pool and thapsigargin-activated Ca2+ pool are partially overlapped --- p.68 / Chapter 3.5 --- Anion secretion activated by Ca2+ -independent pathway --- p.74 / Chapter Chapter 4: --- Discussion --- p.76 / Chapter 4.1 --- The major membrane for the CCE is from the basolateral side --- p.76 / Chapter 4.2 --- Basolateral P2Y receptors --- p.80 / Chapter 4.3 --- Differential effects of apical and basolateral ATP --- p.82 / Chapter 4.3.1 --- Apical and basolateral ATP release Ca2+ from different pools --- p.83 / Chapter 4.3.2 --- Ca2+ -independent mechanism --- p.83 / Chapter 4.3.3 --- Other potential signaling molecules --- p.84 / Chapter Chapter 5: --- Reference --- p.86
3

Further exploration to the cucurbitacin D (LC978) signal transduction pathway during fetal hemoglobin induction.

January 2008 (has links)
Zhang, Siwei. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 87-98). / Abstracts in English and Chinese. / Chapter 1. --- General introduction --- p.1 / Chapter 1.1. --- "Types, structure and function of human hemoglobin" --- p.1 / Chapter 1.1.1. --- Structure and functions of human hemoglobin --- p.1 / Chapter 1.1.2. --- Types of human hemoglobin --- p.2 / Chapter 1.2. --- Regulatory mechanism of human hemoglobin expression --- p.3 / Chapter 1.2.1. --- The human a and β locus --- p.3 / Chapter 1.2.2. --- Development of globin genes switching concept --- p.4 / Chapter 1.2.3. --- Factors that regulate globin gene expression --- p.5 / Chapter 1.2.3.1. --- The locus control region (LCR) --- p.5 / Chapter 1.2.3.2. --- The cis-regulatory elements --- p.5 / Chapter 1.2.3.3. --- The trans-acting factors --- p.6 / Chapter 1.3. --- The human hemoglobinopathies --- p.8 / Chapter 1.3.1. --- α-thalassemia --- p.8 / Chapter 1.3.2. --- β-thalassemia --- p.9 / Chapter 1.3.3. --- Sickle cell anemia --- p.10 / Chapter 1.4. --- Current approaches towards β-thalassemia treatment --- p.11 / Chapter 1.4.1. --- Blood transfusion --- p.11 / Chapter 1.4.2. --- Bone marrow transplantation --- p.12 / Chapter 1.4.3. --- Drug-induced activation of fetal hemoglobin production --- p.12 / Chapter 1.4.3.1. --- Hydroxyurea --- p.12 / Chapter 1.4.3.2. --- Butyrate and short-chain fatty acids --- p.13 / Chapter 1.4.3.3. --- "Mutagens, DNA methyltransferase inhibitors and other HbF inducible agents" --- p.13 / Chapter 1.4.3.4. --- Cucurbitacin D --- p.14 / Chapter 1.4.4. --- Gene therapy --- p.14 / Chapter 1.5. --- Research Objectives --- p.15 / Chapter 2. --- "Analysis of CuD, Hydroxyurea and other inducers on the induction of α, β, γ, δ, ε,ζ BP-1 genes and fetal hemoglobin induction" --- p.16 / Chapter 2.1. --- Introduction --- p.16 / Chapter 2.1.1. --- Properties of human K562 cell line --- p.16 / Chapter 2.1.2. --- Induction and measurement of fetal hemoglobin --- p.16 / Chapter 2.1.3. --- "Induction of α, β, γ, δ, ε , ζ and BP-1 gene and Real-time RT-PCR analysis" --- p.17 / Chapter 2.2. --- Materials --- p.18 / Chapter 2.2.1. --- Chemicals and reagents --- p.18 / Chapter 2.2.2. --- Kits --- p.19 / Chapter 2.2.3. --- Buffers and solutions --- p.19 / Chapter 2.2.4. --- Cell lines --- p.20 / Chapter 2.3. --- Experimental procedures --- p.20 / Chapter 2.3.1. --- Hemoglobin quantity measurement by HbF ELISA --- p.20 / Chapter 2.3.1.1. --- MTT assay --- p.21 / Chapter 2.3.1.2. --- Preparation of capture-antibody coated ELISA plates --- p.21 / Chapter 2.3.1.3. --- Plate blocking --- p.22 / Chapter 2.3.1.4. --- Sample and standard preparation --- p.22 / Chapter 2.3.1.5. --- HRP antibody and colorimetric detection --- p.23 / Chapter 2.3.1.6. --- Statistical analysis --- p.23 / Chapter 2.3.2. --- Preparation of mRNA extract from K562 cells --- p.23 / Chapter 2.3.3. --- Reverse transcription and Real-time PCR analysis --- p.24 / Chapter 2.4. --- Results --- p.25 / Chapter 2.4.1. --- CuD significantly upregulates HbF expression in K562 cells --- p.25 / Chapter 2.4.2. --- "CuD augments α, β, γ, δ, ε , ζ and BP-1 genes at different level in K562 cells" --- p.28 / Chapter 2.4.3. --- Cucurbitacin D-induced γ-globin gene activation requires12-24 hours in K562 cells --- p.31 / Chapter 2.5. --- Discussion --- p.33 / Chapter 2.5.1. --- Enhancement of fetal hemoglobin production using different chemical compounds --- p.33 / Chapter 2.5.2. --- CuD increased HbF synthesis by increasing γ-globin mRNA amount --- p.35 / Chapter 2.5.3. --- CuD and HU down-regulated the BP-1 gene expression --- p.36 / Chapter 3. --- Determination of potential signal transduction pathways during CuD and HU-mediated fetal hemoglobin production --- p.36 / Chapter 3.1. --- Introductions --- p.36 / Chapter 3.1.1. --- The p38 MAPK family --- p.37 / Chapter 3.1.2. --- The JAK2-STAT3 pathway --- p.38 / Chapter 3.1.3. --- Fundamentals on inhibition assay of p38 MAPK and JAK2-STAT3 pathway --- p.39 / Chapter 3.1.4. --- Fundamentals on nuclear translocation of STAT3 --- p.41 / Chapter 3.2. --- Materials --- p.41 / Chapter 3.2.1. --- Chemicals and reagents --- p.41 / Chapter 3.2.2. --- Kits --- p.44 / Chapter 3.2.3. --- Buffers and solutions --- p.44 / Chapter 3.3. --- Experimental procedures --- p.45 / Chapter 3.3.1. --- Detection of p3 8 MAPK phosphorylation status --- p.46 / Chapter 3.3.1.1. --- Preparation of cytosolic protein extracts --- p.46 / Chapter 3.3.1.2. --- Quantitative measurement of phospho-p38 and pan-p38 by ELIS A method --- p.46 / Chapter 3.3.1.2.1. --- Antigen adsorption and establishment of standard curves --- p.46 / Chapter 3.3.1.2.2. --- Plate washing and application of detection antibody --- p.47 / Chapter 3.3.1.2.3. --- Plate washing and application of secondary antibody --- p.47 / Chapter 3.3.1.2.4. --- Plate washing and chromogen detection --- p.48 / Chapter 3.3.2. --- Detection of signal cascade on JAK2-STAT3 pathway --- p.48 / Chapter 3.3.2.1. --- Preparation of cytosolic protein extracts for Western Blot detection --- p.48 / Chapter 3.3.2.2. --- Gel running and Western Blot detection --- p.48 / Chapter 3.3.3. --- Quantitative measurement of phospho-STAT3-Tyr705 using ELISA method --- p.50 / Chapter 3.3.3.1. --- Preparation of cytosolic protein extracts --- p.50 / Chapter 3.3.3.2. --- Reconstitution and Dilution of STAT3 [pY705] Standard --- p.50 / Chapter 3.3.3.3. --- Measurement of STAT3 [pY705] concentration in cell lysates --- p.51 / Chapter 3.3.4. --- Inhibitor assay of JAK2-STAT3 and p38 MAPK pathway --- p.52 / Chapter 3.3.4.1. --- Establishment of inhibitor assay --- p.52 / Chapter 3.3.4.2. --- HbF ELISA detection --- p.53 / Chapter 3.3.5. --- Detection of STAT3 nuclear translocation and DNA binding affinity --- p.53 / Chapter 3.3.5.1. --- Preparation of nuclear extract from K562 cells --- p.53 / Chapter 3.3.5.2. --- EMS A detection of transcriptional factors binding to γ-promoter region --- p.54 / Chapter 3.3.5.2.1. --- 3´ة end-labeling of EMS A probes --- p.54 / Chapter 3.3.5.2.2. --- Dot blotting for labeling efficiency estimation --- p.56 / Chapter 3.3.5.2.3. --- EMSA binding reaction and non-denaturing gel electrophoresis --- p.57 / Chapter 3.3.5.2.4. --- Membrane development and chemiluminescence detection --- p.58 / Chapter 3.3.5.3. --- Preparation of K562 samples for immunofluorescence detection --- p.60 / Chapter 3.3.5.3.1. --- Slide coating for cell capture --- p.60 / Chapter 3.3.5.3.2. --- Preparation of cell slide --- p.60 / Chapter 3.3.5.3.3. --- Sample fixation and antibody probing treatment --- p.60 / Chapter 3.3.5.3.4. --- Sample imaging and immunofluorescence detection --- p.61 / Chapter 3.4 --- Results --- p.62 / Chapter 3.4.1. --- Activation of p38 MAPK pathway and STAT3 phosphorylation by hydroxyurea --- p.62 / Chapter 3.4.1.1. --- "The p38 MAPK pathway is activated by hydroxyurea, but not activated by Cucurbitacin D" --- p.62 / Chapter 3.4.1.2. --- Increased p38 phosphorylation level elicits STAT3 phosphorylation at Ser727 site --- p.64 / Chapter 3.4.2. --- Activation of JAK2 and STAT3 phosphorylation by Cucurbitacin D --- p.66 / Chapter 3.4.2.1. --- Cucurbitacin D promotes JAK2 activation --- p.66 / Chapter 3.4.2.2. --- Cucurbitacin D and hydroxyurea promote STAT3 phosphorylation at Tyr705 site --- p.66 / Chapter 3.4.3. --- Basal activity of signal transduction pathways is essential for HbF induction --- p.69 / Chapter 3.4.3.1. --- Activation of γ-globin gene requires presence of basal phosphorylation level of p38 MAPK --- p.69 / Chapter 3.4.3.2. --- Inhibition on JAK2-STAT3 pathway results in reduced fetal hemoglobin production --- p.71 / Chapter 3.4.4. --- Translocation and DNA binding of STAT under Cucurbitacin D induction --- p.72 / Chapter 3.4.4.1. --- Cucurbitacin D and hydroxyurea both enhance binding affinity of transcriptional factors to the Gγ/Aγ promoter --- p.72 / Chapter 3.4.4.2. --- Cucurbitacin D and hydroxyurea induces nuclear translocation of STAT3 --- p.75 / Chapter 3.5. --- Discussion --- p.77 / Chapter 3.5.1. --- The role of p38 MAPK activation during γ-globin gene activation --- p.77 / Chapter 3.5.2. --- STAT3 phosphorylation at Ser727 site promotes transcription factor activity and γ-globin gene expression --- p.77 / Chapter 3.5.3. --- The role of JAK2-STAT3 activation during γ-globin gene activation --- p.78 / Chapter 3.5.4. --- Inhibitor assay --- p.79 / Chapter 3.5.5. --- Relations between STAT3 nuclear translocation and enhanced fetal hemoglobin production --- p.82 / Chapter 4. --- Summery and Prospect --- p.83 / Chapter 5. --- References --- p.87
4

The role of Ras and Kinase Suppressor of Ras 1 (KSR-1) in breast cancer in progression and metastasis /

De Cristofano, Sabrina. January 2007 (has links)
The Ras signaling cascade is a vital component in the processes that mediate cell survival, growth, differentiation and transformation through activation of MAP kinase (mitogen-activated protein kinase). The recent discovery of a new scaffold of the Ras signaling pathway, Kinase Suppressor of Ras (KSR), is found to be a positive effector of Ras signaling which further contributes to proliferation and transformation in the ERK/MAPK pathway. This thesis describes the roles of Ras and Kinase Suppressor of Ras 1 (KSR-1) in regulating the expression of tumor promoting genes such as urokinase plasminogen activator (uPA) in the development and progression of breast cancer in vitro and in vivo. Ras and KSR increase the proliferative capacity and migration of MDAMB-231 human breast cancer cells in vitro. In contrast, Ras and KSR decrease the invasiveness of MDA-MB-231 human breast cancer cells in vitro. Furthermore, uPA gene expression levels do not correlate with uPA protein expression levels suggesting a possible mutation induced by KSR and/or Ras. In vivo studies reveal that Ras and KSR increase tumor volume in mice, as well as more advanced osteolytic bone metastases. Collectively, these results indicate that Ras and KSR play significant roles in breast cancer development and metastasis.
5

The role of Ras and Kinase Suppressor of Ras 1 (KSR-1) in breast cancer in progression and metastasis /

De Cristofano, Sabrina. January 2007 (has links)
No description available.
6

Heteromeric TRPV4-C1-P2 and TRPV4-P2 channels: assembly and function. / CUHK electronic theses & dissertations collection

January 2011 (has links)
Du, Juan. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 110-134). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.
7

Signaling mechanism underlying the stimulatory effects of Bak Foong pills and its active components on gastrointestinal epithelia. / CUHK electronic theses & dissertations collection

January 2004 (has links)
Zhu Jinxia. / "July 2004." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (p. 142-170). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.
8

Growth hormone secretagogue receptors: cell signalling and receptor oligomerization. / CUHK electronic theses & dissertations collection

January 2005 (has links)
In a HEK 293 cell line stably expressing seabream GHS-R1a (sbGHS-R1a), we found that a synthetic growth hormone secretagogue (GHS) increased [ 3H]-inositol phosphate production, clearly indicating coupling of this receptor to Gq/11-proteins. Using Western blotting, we found that GHS could also stimulate extracellular signal-regulated kinases 1 and 2 (ERK1/2), and that this response was inhibited by the MEK inhibitor U0126. For both the [3H]-inositol phosphate and ERK1/2 assays, the presence of the GHS-R antagonist D-Lys(3)-GHRP-6 significantly inhibited the GHS-stimulated activities, and in addition inhibited basal activities by 50% and 40%, respectively. These results showed that sbGHS-R1a is a constitutively active receptor and the antagonist D-Lys(3)-GHRP-6 is an inverse agonist. We also proposed that the expression of sbGHS-Rs was involved in the regulation of cell apoptosis. / Oligomerization of the human GHS-Rs (hGHS-Rs) was explored by transient transfection of the hGHS-Rs in HEK 293 cells followed by co-immunoprecipitation of differentially epitope-tagged forms of the receptors and bioluminescence resonance energy transfer 2 (BRET2) studies. (Abstract shortened by UMI.) / The concept that G protein-coupled receptors (GPCRs) exist and potentially function as dimers and/or higher oligomers has progressed from hypothesis to being widely accepted recently. Oligomerization of GPCRs has been increasingly noted in the regulation of the biological activity of the receptors. The growth hormone secretagogue receptor 1a (GHS-R1a) is a GPCR which principally regulates the pulsatile release of growth hormone from the pituitary gland. The GHS-R exists in two forms: GHS-R1a being a constitutively-active GPCR with 7 transmembrane (TM) domains, and GHS-R1b being a truncated version of type 1a but having only 5 TM domains. The endogenous agonist for GHS-R1a is ghrelin which exerts a wide range of physiological actions, but the function of GHS-R1b is still unclear. Since the tissue distribution patterns of the two isoforms of GHS-R are different, the objective of the present study is to explore the mechanisms of cell signalling of GHS-R1a and to determine the extent and importance of interactions between these two receptor isoforms. / Leung Po Ki. / "July 2005." / Adviser: Helen Wise. / Source: Dissertation Abstracts International, Volume: 67-07, Section: B, page: 3728. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (p. 189-210). / 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, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / School code: 1307.
9

Regulation of TRPC3-mediated Ca2+ influx and flow-induced Ca2+ influx. / Regulation of TRPC3-mediated [calcium ion] influx and flow-induced [calcium ion] influx / CUHK electronic theses & dissertations collection

January 2006 (has links)
Kwan Hiu Yee. / "June 2006." / 2+ in the title is superscript. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (p. 131-150). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese.
10

Calcium-related signal transduction systems in developing visual cortex

Jia, Wei-Guo January 1991 (has links)
Neuronal connections in cat visual cortex are highly susceptible to visual experience at early postnatal age and thus serve as a useful model of neural plasticity. The biochemical mechanisms underlying this cortical plasticity remain unclear. In this thesis, the development of several elements in calcium-related signal transduction systems, including the type-1 muscarinic and alpha-1 adrenoceptor systems as examples of cell surface receptors and protein kinase C. calcium/calmodulin dependent kinase II and inositol 1,4,5 phosphotate receptors as second messenger targets, were investigated using the methods of immunocytochemistry and autoradiography. The results show that each receptor develops with its own time-table and laminar distribution; the various elements all culminate and display the maximal colocalization during the critical period; and, only at this age, the cortical levels of the receptors and kinases are dependent on subcortical afferents. The results suggest that cell surface receptors and their second messenger targets develop in specific temporal and spatial patterns, which may be both genetically and environmentally determined, and this specific sequence of development of the molecules for signal transduction results in a series of modifications in the morphology and physiology of the developing cortex leading to its maturation. / Medicine, Faculty of / Graduate

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