by Lau Kwok Wing, Wilson. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1996. / Includes bibliographical references (leaves 166-188). / ACKNOWLEDGEMENTS --- p.i / ABBREVIATIONS --- p.ii / ABSTRACT --- p.v / TABLE OF CONTENTS --- p.viii / Chapter CHAPTER 1 : --- GENERAL INTRODUCTION --- p.1 / Chapter (1.1) --- Hematopoiesis : An Overview --- p.2 / Chapter (1.1.1) --- Development of Blood Cells and Sites of Hematopoiesis --- p.2 / Chapter (1.1.2) --- Hematopoietic Cytokine Network --- p.4 / Chapter (1.1.3) --- Molecular Control of Hematopoietic Cell Development --- p.5 / Chapter (1.2) --- Leukemia : An Overview --- p.8 / Chapter (1.2.1) --- Leukemia : Abnormalities in Blood Cell Formation --- p.8 / Chapter (1.2.2) --- Pathophysiology and Etiology of Leukemia --- p.10 / Chapter (1.2.3) --- New Avenues for Therapy : Induction of Differentiation and Apoptosis --- p.12 / Chapter (1.3) --- Induction of Differentiation in Myeloid Leukemia Cells --- p.14 / Chapter (1.3.1) --- Inducers of Leukemic Cell Differentiation --- p.14 / Chapter (1.3.2) --- Cytokines as Inducers of Myeloid Leukemic Cell Differentiation --- p.17 / Chapter (1.3.3) --- Phenotypic Changes and Functional Characterizations --- p.20 / Chapter (1.3.4) --- Modulation of Gene Expression in Myeloid Leukemic Cell Differentiation --- p.22 / Chapter (1.4) --- Apoptosis and Leukemic Cell Death --- p.23 / Chapter (1.4.1) --- Apoptosis : An Overview --- p.23 / Chapter (1.4.2) --- Cytokines and Apoptosis in Myeloid Leukemia --- p.26 / Chapter (1.5) --- Objectives and Research Strategy --- p.27 / Chapter (1.5.1) --- The Murine Myeloid Leukemia Cell Line (Ml) as an Experimental Cell Model for Acute Myeloid Leukemia --- p.27 / Chapter (1.5.2) --- Leukemia Inhibitory Factor (LIF) as a Differentiation Inducer --- p.28 / Chapter (1.5.3) --- Aims and Scopes of This Investigation --- p.31 / Chapter CHAPTER 2 ： --- MATERIALS AND METHODS --- p.33 / Chapter (2.1) --- Materials --- p.34 / Chapter (2.1.1) --- Mice --- p.34 / Chapter (2.1.2) --- Cell Lines --- p.34 / Chapter (2.1.3) --- Recombinant Cytokines --- p.34 / Chapter (2.1.4) --- Monoclonal Antibodies --- p.36 / Chapter (2.1.5) --- Oligonucleotide Primers and Internal Probes --- p.37 / Chapter (2.1.6) --- "Buffers, Culture Medium and Other Reagents" --- p.39 / Chapter (2.1.7) --- Reagents and Solutions for Gene Expression Study --- p.41 / Chapter (2.2) --- Methods --- p.46 / Chapter (2.2.1) --- Culture of Myeloid Leukemia Cell Lines --- p.46 / Chapter (2.2.2) --- Induction of Leukemic Cell Differentiation --- p.46 / Chapter (2.2.3) --- Determination of Cell Growth and Proliferation --- p.46 / Chapter (2.2.4) --- Cell Morphological Study --- p.47 / Chapter (2.2.5) --- Assessment of Differentiation-Associated Characteristics --- p.48 / Chapter (2.2.5.1) --- Nitroblue Tetrazolium (NBT) Reduction Assay --- p.48 / Chapter (2.2.5.2) --- Phagocytosis Assay --- p.48 / Chapter (2.2.5.3) --- Assay of Plastic Adherence --- p.49 / Chapter (2.2.6) --- Flow Cytometric Analysis --- p.49 / Chapter (2.2.6.1) --- Surface Antigen Immunophenotyping --- p.49 / Chapter (2.2.6.2) --- Assay of Endocytic Activity --- p.50 / Chapter (2.2.6.3) --- Assay of Non-specific Esterase Activity --- p.50 / Chapter (2.2.6.4) --- Cell Cycle / DNA Content Evaluation --- p.51 / Chapter (2.2.7) --- Gene Expression Analysis --- p.52 / Chapter (2.2.7.1) --- Preparation of Cell Lysate --- p.52 / Chapter (2.2.7.2) --- RNA Isolation --- p.52 / Chapter (2.2.7.3) --- Reverse Transcription --- p.53 / Chapter (2.2.7.4) --- Polymerase Chain Reaction (PGR) --- p.54 / Chapter (2.2.7.5) --- Agarose Gel Electrophoresis --- p.55 / Chapter (2.2.7.6) --- 3' End Labelling of Oligonucleotide Probes --- p.56 / Chapter (2.2.7.7) --- Dot Blot Hybridization --- p.56 / Chapter (2.2.7.8) --- Digoxigenin (DIG) Chemiluminescent Detection --- p.57 / Chapter (2.2.8) --- DNA Fragmentation Analysis --- p.58 / Chapter (2.2.9) --- Statistical Analysis --- p.59 / Chapter CHAPTER 3 ： --- "EFFECTS OF LEUKEMIA INHIBITORY FACTOR ON THE PROLIFERATION, DIFFERENTIATION, AND APOPTOSIS OF MURINE MYELOID LEUKEMIA Ml CELLS" --- p.60 / Chapter (3.1) --- Introduction --- p.61 / Chapter (3.2) --- Results --- p.63 / Chapter (3.2.1) --- Induction of Growth Arrest in rmLIF-Treated Ml Cells --- p.63 / Chapter (3.2.2) --- Induction of Monocytic Differentiation of Ml cells by rmLIF --- p.66 / Chapter (3.2.2.1) --- Morphological Changes --- p.66 / Chapter (3.2.2.2) --- Induction of Plastic Adherence --- p.70 / Chapter (3.2.2.3) --- Surface Antigen Immunophenotyping --- p.70 / Chapter (3.2.2.4) --- NBT-Reducing Activity of rmLIF-Treated Ml Cells --- p.76 / Chapter (3.2.2.5) --- Non-specific Esterase Activity of rmLIF-Treated Ml Cells --- p.77 / Chapter (3.2.2.6) --- Endocytic Activity of rmLIF-Treated Ml Cells --- p.78 / Chapter (3.2.2.7) --- Phagocytic Activity of rmLIF-Treated Ml Cells --- p.79 / Chapter (3.2.3) --- Induction of Differentiation-Associated DNA Fragmentation --- p.80 / Chapter (3.2.4) --- Production of Differentiation-Inducing Factors --- p.84 / Chapter (3.3) --- Discussion --- p.88 / Chapter CHAPTER 4 : --- CYTOKINE INTERACTIONS IN REGULATING THE PROLIFERATION AND DIFFERENTIATION OF MURINE MYELOID LEUKEMIA Ml CELLS --- p.94 / Chapter (4.1) --- Introduction --- p.95 / Chapter (4.2) --- Results --- p.97 / Chapter (4.2.1) --- Synergistic Effect of LIF and IL-6 on the Proliferation and Differentiation of Ml Cells --- p.97 / Chapter (4.2.2) --- Regulation of Proliferation and Differentiation of Ml Cells by LIF and OSM --- p.101 / Chapter (4.2.3) --- Effects of LIF and TNF-α on the Proliferation and Differentiation of Ml Cells --- p.104 / Chapter (4.2.4) --- Synergistic Effect of LIF and IL-1 on the Proliferation and Differentiation of Ml Cells --- p.107 / Chapter (4.3) --- Discussion --- p.115 / Chapter CHAPTER 5 ： --- MODULATION OF CYTOKINE AND CYTOKINE RECEPTOR GENE EXPRESSION IN LIF- INDUCED DIFFERENTIATION OF MURINE MYELOID LEUKEMIA Ml CELLS --- p.120 / Chapter (5.1) --- Introduction --- p.121 / Chapter (5.2) --- Results --- p.123 / Chapter (5.3) --- Discussion --- p.152 / Chapter CHAPTER 6 ： --- CONCLUSIONS AND FUTURE PERSPECTIVES --- p.158 / REFERENCES --- p.166

After naïve lymphocytes are activated by foreign antigens, they yield cellular progeny with diverse functions, including memory cells, effector cells, and precursors of germinal center B cells. However, it remains unclear whether a naïve lymphocyte is capable of generating daughter cells with multiple fates or multiple naive cells are activated and each give rise to daughter cells with different cell fates. This dissertation analyzes the role of asymmetric cell division in the generation of effector lymphocytes and maintenance of progenitor cells. Our data provide evidence that daughter cells exhibit differential mitochondrial stasis and inherit different amounts of glucose transporters, which is coupled to distinct metabolic and transcriptional program in the sibling cells. To uncover the links between mitochondrial stasis, transcription network reprogramming and cell fate, we perturbed mitochondrial clearance with pharmacological and genetic approaches. I found that the treatments, which impaired mitochondrial function, increased the differentiation of B cells and T cells into effector subsets. Thus, we hypothesize that mitochondrial stasis could be a trigger for effector cell differentiation. To further explore the mechanism for aged mitochondria-induced shifts in transcriptional and metabolic programs, we used reactive oxygen species (ROS) scavengers and glycolysis inhibitors to demonstrate that mitochondria function and the expressions of lineage-specific transcription factors crosstalk through ROS-mediated signaling and activating AMPK. ROS scavenger treatments helped to maintain the progenitor population and suppressed the differentiation of effector subsets, whereas effector cell differentiation was boosted in the AMPK-α1 knockout. These results suggest mitochondrial stress-induced ROS is required for repressing Pax5 and increasing IRF4. In addition to showing mitochondrial stasis’ connection to cell fate, this dissertation also demonstrates the linkage between phosphatidylinositol-3-kinases and glucose transporter 1 (Glut1) in establishing polarity in dividing cells and in transcriptional reprogramming. In sum, this dissertation suggests that asymmetric mitochondrial stasis and nutrient up-take could be part of the driving force of cell fate owing to self-reinforcement and reciprocal inhibition between anabolism and catabolism. These results shed light on the deterministic mechanism of effector cell differentiation and provide clues to the basis of maintenance of self-renewal by activated lymphocytes. These findings could be beneficial for producing memory cells and preventing effector cell exhaustion phenotype in a chronic infection or in cancer microenvironment.

A thesis submitted to the Faculty of Science, University of the Witwatersrand, in fulfilment of the requirements for the degree of Doctor of Philosophy Johannesburg, 2011. / The phosphotidylinositide-3-kinase (PI3K) pro-survival signalling pathway is critical in the development of cancer. Major contributors to the proliferative and/or anti-proliferative signalling in human oesophageal squamous cell carcinoma (HOSCC) are currently unknown. Based on the Ser473 phosphorylation state of PKB (pPKB), this study dissects the overall activation status of the PI3K/PKB pathway. Despite the prevalent membrane expression of PI3K determined through western blotting and immunofluorescence, pPKB levels were shown to be surprisingly low. Activation of EGFR did not produce a hyperactivation of the PI3K/PKB pathway. Neither PI3K nor PKB sequence isolated from the 5 HOSCC cell lines possessed any of the ―hotspot‖ mutations described previously for other tumours. Inhibiting phosphatase protein 2A (PP2A), an integral antagonist of PKB, indicated that its activity in respect of PKB is diminished in HOSCC cells. Despite the low concentration of pPKB, the reciprocal relationship with PTEN expression was not evident in the WHCO and SNO HOSCC series. Moreover, reversible oxidization and inhibition of PTEN served to augment the activation of the PI3K/PKB pathway. Since oxidation of PTEN is imperative for effective signal propagation from activated EGFR and PI3K, these data reveal an aberrant EGFR-PI3K-H2O2 mediated PTEN inhibition in HOSCC. Allied to this discovery, was the finding that HOSCC cells are highly susceptible to oxidative stress induced by H2O2. This was suggested to play an essential part in maintaining the low PI3K/PKB activation status. Although the decrease in PTEN activity was required for the induction of pPKB, PTEN may not be the only limiting component for the activation of the PI3K/PKB pathway in HOSCC. In addition to its overexpressed EGFR status, the WHCO and SNO HOSCC series have the propensity to appropriate nuclear β-catenin. Interruption of the PI3K/PKB signalling pathway caused a small, yet significant, depression in the nuclear localization of β-catenin in 3 of the HOSCC cell lines. Together, this work greatly expands our understanding of the major influences behind the proliferative and/or anti-proliferative signalling in HOSCC, primarily that, the EGFR overexpression status does not propagate these transforming capabilities via activation of the PI3K/PKB pathway, and that this may be a reflection of its transformation potential. The findings derived from this study are likely to have a profound impact on future therapeutic targets for this disease.

The lens is responsible for focusing light into the retina. It accomplishes this through its maturation from an epithelial cell into a fiber cell. A large amount of research has been done on cellular differentiation. Nevertheless, we still lack knowledge on many different aspects of differentiation, including a complete theory on the mechanism behind differentiation. Due to the lens’ unique structure and cell types, this is an ideal model for studying differentiation. Our research has shown that αB crystallin, a small heat shock protein, is able to modulate cytochrome C levels and protect the mitochondria under oxidative stress. Also, cytochrome C release is often followed by caspase 3 activation. In addition, research has shown that low levels of caspase 3 activation is essential in driving differentiation. My work examined if αB crystallin could modulate cytochrome C to lower caspase 3 levels to allow for differentiation rather than apoptosis. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2019. / FAU Electronic Theses and Dissertations Collection

Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 109-118).

Thesis (M. Phil.)--University of Hong Kong, 2007. / Also available online.

Thesis (Ph. D.)--University of Hong Kong, 2006. / Title proper from title frame. Also available in printed format.

Thesis (M. Phil.)--University of Hong Kong, 2007. / Title proper from title frame. Also available in printed format.

Thesis (M. Phil.)--University of Hong Kong, 2007. / Title proper from title frame. Also available in printed format.

Thesis (Ph. D.)--Ohio State University, 2006. / Title from first page of PDF file. Includes bibliographical references (p. 115-136).