Thesis (Ph. D.)--University of Missouri--Columbia, 2003. / "December 2003." Typescript. Vita. Includes bibliographical references (leaves 172-205). Also issued on the Internet.

Thesis (Ph. D.)--University of Washington, 2003. / Vita. Includes bibliographical references (leaves 99-131).

published_or_final_version / Obstetrics and Gynaecology / Master / Master of Philosophy

During the growth phase of oogenesis, mammalian oocytes increase several hundred-fold in volume. Although it is known that ovarian granulosa cells send growth promoting signals, neither these external signals nor the transduction pathways that become activated in the oocyte are known. Therefore, the presence and the activity of candidate signaling pathways in growing murine oocytes were investigated. By immunoblotting, the MAP kinases, ERK1 and ERK2, as well as their activating kinase MEK, were detected in oocytes at all stages of growth. However, using a phospho-specific anti-ERK antibody, no immunoreactive species were detectable in isolated granulosa cells or oocytes at any stage of growth, except metaphase II. Phosphorylated ERK was also present, although in smaller quantities, in oocyte-granulosa cell complexes at the later stages of growth. Furthermore, when ovarian sections were stained with an anti-ERK antibody, the protein was found to be highly concentrated in the cytoplasm of oocytes at all stages of growth, with lower levels in the nucleus. Another member of the MAP kinase family, Jun kinase (JNK), was investigated. By immunoblotting, JNK was detected in growing oocytes. Experiments using an anti-JNK antibody on ovary sections revealed the protein to be uniformly distributed in non-growing and growing oocytes with no evidence of preferential nuclear localization. These results imply that an interaction between the oocyte and the granulosa cells may be required to generate phosphorylated ERK. They also imply that growth signals probably are not relayed through ERK, but do not exclude a role for Jun kinase in mediating oocyte growth.

In C. albicans, a MAP kinase pathway has been implicated in aspects of controlling hyphal development. We have examined the transcription profile of cells deleted for the transcription factor Cph1 as well as Cst20, Hst7 and Cek1, three upstream kinases potentially involved in Cph1 regulation. Deletion of these four elements does not block filament induction by serum and does not dramatically affect the transcription profile of yeast-hyphal transition, but deletion of CPH1 delays filamentation. Over-expression of Cph1 by ADH1pt-CPH1 significantly enhances filamentation, suggesting that Cph1 is helpful but not essential for filament induction. Interestingly, the transcription profile of ADH1pt-CPH1 expressing cells under yeast conditions is similar to that of wild type strains undergoing the yeast-hyphal transition. Finally, it appears that Cek1 and its regulators Hst7 and Cst20 may control the repression of genes such as CHT2 through a process independent of the Cph1p transcription factor.

T cells are involved in cellular pathways which enable the immune system to protect us against infection and cancer. However, the same mechanisms also allow T cells to generate chronic inflammatory conditions, including autoimmunity and allergy. Thus a concerted effort has been made to try to understand how the immune system functions in order to inhibit responses which may have harmful effects on tissues and organs. There is a continued search for new immunosuppressants which can only be accomplished through a better understanding of the pathways that regulate T cell function. This includes the intracellular signalling pathways which modulate T cell proliferation and cytokine production. While the Mitogen-Activated Protein Kinases (MAPK), extracellular signal-regulated protein kinases (ERK) and p38 have received attention, the role of the stress-activated protein kinases or c-jun N-terminal kinases (JNK) remains controversial. To overcome some of the limitations in studying the role of JNK, a new approach was taken in this thesis. The investigations used recently described peptides (TAT-JIP[subscript]153-163 and TAT-JIP[subscript]153-172) derived from the scaffold protein, JIP-1, which have previously been demonstrated to act as JNK pathway inhibitors. The research characterised the specificity of these inhibitors to enable the appropriate interpretation of data. Using these inhibitors, we were able to show that JNK regulated human T cell proliferation and cytokine production in T cell responses induced independently of TCR ligation (PHAPMA) or via the TCR (anti-CD3-anti-CD28 antibodies, Mixed Lymphocyte Reaction (MLR), Tetanus Toxoid and Der p 2). The data demonstrated that JNK primarily regulated the Th1 cytokine patterns (IFNγ, IL2 and LT) with minimal effect on Th2 cytokine production (IL4, IL10) in response to all stimulatory models. However, while the JNK signalling pathway promoted T cell proliferation and cytokine production in response to PHA-PMA, the pathway depressed these responses following stimulation with anti-CD3-anti-CD28 antibodies and Tetanus Toxoid. Thus activation of JNK with microbial pathogens such as Pseudomonas aeruginosa (PA), which non-specifically activate T cells, may promote lymphocyte proliferation and the release of Th1 cytokines, such as IFNγ. In contrast, JNK activation resulting from engagement of the T cell receptor (TCR) (i.e. Tetanus Toxoid), down-regulates Th1 cytokine production. Therefore, it is likely that the JNK signalling pathway may dampen the development of chronic inflammatory conditions resulting from infection with intracellular parasites and autoimmune diseases. In contrast to Tetanus Toxoid, responses to the recombinant house dust mite allergen, Dermatophagoides pteronyssinus (Der p 2) were promoted by JNK, leading to an increase in Th1 cytokine production. Thus the results suggest that the use of JNK inhibitors could exacerbate both inflammatory conditions (autoimmunity and allergy) and this may also apply to p38 but not the ERK signalling pathway. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1374669 / Thesis (Ph.D.) - University of Adelaide, School of Molecular and Biomedical Science, 2009

Diss. (sammanfattning) Uppsala : Univ., 2002. / Härtill 3 uppsatser.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2002. / Härtill 5 uppsatser.

Diss. (sammanfattning) Stockholm : Karol. inst., 2003. / Härtill 5 uppsatser.

Diss. (sammanfattning) Stockholm : Karol. inst., 2003. / Härtill 4 uppsatser.