Title page, summary and table of contents only. The complete thesis in print form is available from the University of Adelaide Library. / Tumor necrosis factor (TNF) is a pro-inflammatory cytokine with multiple biological effects. The receptors for this cytokine on neutrophils have been shown to be rapidly down-regulated following activation, leading to the release of soluble forms of these receptors. Thus neutrophils become less responsive to TNF and the soluble TNF receptors (TNFR) serve to control TNF activity. During inflammation, leukocytes become activated as a result of the action of a variety of mediators. These mediators include not only cytokines but also lipids, such as the pro-inflammatory 00-6 fatty acid, arachidonic acid (AA) and its metabolites. Cellular activation leads to the release of AA from membrane phospholipids. AA regulates the function of many cell types including neutrophils. In view of the known pro-inflammatory properties of AA and the anti-inflammatory properties of 00-3 fatty acids, a study was undertaken to examine whether or not these fatty acids regulate the expression and release of TNFR in neutrophils. While much emphasis has been placed on agonist-induced down-regulation of TNFR, our data show that AA causes a rapid (10-20 min) and dose-dependent (0.5 to 30 uM) increase (8-fold) in the surface expression of both classes of TNFR (TNFRl and TNFRlI) on human neutrophils, at concentrations found in inflammatory fluids. This correlates with an increase in superoxide production to a TNF challenge. In contrast, both fMLP and LPS significantly reduce the expression of both TNF receptors. Interestingly, in neutrophils pretreated with AA, fMLP causes an increase in TNF receptor expression, consistent with AA preventing the fMLP-induced receptor release in neutrophil culture. In addition, while AA causes an increase in TNF receptor expression on matured HL-60 cells (neutrophil-like cells), a decrease occurs on HUVEC and non-matured HL-60 cells. These data demonstrate a unique effect of AA on neutrophils. The relationship between AA and the anti-inflammatory (0-3 fatty acids, DHA and eicosapentaenoic acid (EPA), in the modulation of TNF receptor expression has also been examined. These (0-3 polyunsaturated fatty acids, including linolenic acid (LNA), cause a decrease in TNFR expression on neutrophils. The (0-6 linoleic acid (LA) and (0-9 oleic acid (OA) both cause an increase in TNFR expression. Furthermore, pre-exposure of neutrophils to nanomolar amounts of EPA or DHA prevents the AA-induced up-regulation of TNFR. These results thus identify another mechanism of regulating the inflammatory reaction by the (0-3 fatty acids. The mechanisms by which AA induces an increase in TNFR expression have been studied. Masking of the carboxyl group results in loss of activity. It is unlikely that a product of AA is responsible since neither the hydroperoxyeicosatetraenoic acid, nor hydroxyeicosatetraenoic acid derivatives show activity. Also, the effects of AA are not sensitive to the action of inhibitors of the cyclooxygenases and lipoxygenases. Using chemical inhibitors of intracellular signaling pathways, we demonstrate that the effect of AA on TNFRI is very sensitive to GFI09203X, PD098059, AACOCF3 and wortmannin, showing a role for protein kinase C, the extracellular signal regulated protein kinases and cytoplasmic phospholipase A2, and PI-3 kinase respectively, in the enhancement of TNF receptor expression by AA. Although the effects of AA on TNFRII are also decreased by the chemical inhibitors, the results show that these signalling molecules only contribute in part to the mechanisms of increased TNFRII receptor expression. The data presented in this thesis suggest a novel role for AA in the inflammatory reaction, through its action on neutrophil TNFR expression. The work has identified a unique effect of 00-3 polyunsaturated fatty acids for regulating this AA-induced increase in the expression of TNF receptors. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1141955 / Thesis (Ph.D.) -- University of Adelaide, Dept. of Paediatrics, 2004

Thesis (Ph. D.)--Oregon State University, 2008. / Printout. Includes bibliographical references (leaves 91-109). Also available on the World Wide Web.

Diss. (sammanfattning) Umeå : Univ., 2004. / Härtill 4 uppsatser.

Thesis (M.S.)--Duquesne University, 2004. / Title from document title page. Abstract included in electronic submission form. Includes bibliographical references (p. 50-57) and index.

Thesis (Ph. D.)--University of Delaware, 2005. / Principal faculty advisor: Sharon L. Neal, Dept. of Chemistry & Biochemistry. Includes bibliographical references.

Thesis (Ph.D.)--University of California, San Francisco, 2004. / Includes bibliographical references. Also available online.

No description available.

N-Acylethanolamines (NAEs) are enriched in seed-derived tissues and are believed to be formed from the membrane phospholipid, N-acylphosphatidylethanolamine (NAPE) via the action of phospholipase D (PLD). In an effort to identify a functional NAPE-PLD in cotton seeds and seedlings, we have screened a cotton seedling cDNA (cotyledon mRNA from 48 h dark grown seedlings) library with a 1.2 kb tobacco partial cDNA fragment encoding the middle third of a putative PLDβ/γ (genbank accession, AF195614) isoform. Six plaques were isolated from the Uni-ZAP lambda library, excised as pBluescript SK(-) phagemids and subjected to nucleotide sequence analysis. Alignment of derived sequences with Arabidopsis PLD family members indicated that the cDNAs represent six different PLD gene products -three putative PLD β isoforms and three putative PLD δ isoforms. The PLD β isoforms, designated Ghpldβ1a, GHpldβ1b and a truncated Ghpldβ1b isoform. Both the full-length PLD β proteins contained characteristic HKxxxxD catalytic domains, a PC-binding domain, a PIP2-binding domain and a C2 domain. In addition both cotton PLD β isoforms had a N-terminal "SPQY" rich domain which appeared to be unique to these PLDs. The three PLD δ isoforms, designated Ghpldδ1a, Ghpldδ1b and Ghpldδ1b-2 encode full-length PLDδ proteins, and like the above PLDs, contained the characteristic catalytic and regulatory domains. The expression of Ghpldδ1b showed hydrolytic and transphosphatidylation activity toward radiolabelled phosphatidylcholine (PC) but it appears Ghpldδ1b does not utilize NAPE as a substrate to produce NAEs nor does it seem to be suppressed by NAEs.

The thesis is dedicated to the phospholipids and their polar headgroups analysis by gas chromatography, capillary electrophoresis and mass spectrometry. Phospholipids are the most important polar lipids and they are classified into phospholipid classes according to their phosphorylated groups. Phospholipids can be found in cell membranes and the changes in their ratio are monitored to research the impact of external conditions on cells. Actually thin layer chromatography is still used for phospholipid class ratio analyses. It is not suitable for microbiological research due to its time demandingness. The presented compendium of papers engaged in phospholipid classification is targeted on Bacillus subtilis strain, which produces potential antibiotics with detergent effect - surfactin. Published methods can be used for research of optimal conditions for producing microbe cultivation. Because non-polar parts of the phospholipid molecule (fatty acids) can affect the analysis methods on spliced polar headgroups have to be designed. Capillary electrophoresis and gas chromatography methods were developed and the latter one was further optimized for simultaneous analysis with fatty acids. Additional part deals with an alternative approach which consists in direct injection on mass spectrometer of intact...

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