Thesis (Ph. D.)--University of Washington, 2007. / Vita. Includes bibliographical references (leaves 95-113).

Diss. (sammanfattning) Stockholm : Karol. inst., 2006. / Härtill 4 uppsatser.

Thesis (Ph. D.)--Carleton University, 2004. / Includes bibliographical references (p. 200-217). Also available in electronic format on the Internet.

Thesis (Ph. D.)--University of Washington, 2004. / Vita. Includes bibliographical references (leaves 106-122).

Stuttgart, Univ., Diss., 2002.

Thesis (Ph.D.) -- University of Texas Southwestern Medical Center at Dallas, 2006. / Embargoed. Vita. Bibliography: 180-194.

IL-1α and IL-1β are two IL-1 agonists which signals at the same receptor complex composed of IL-1R1/IL-1RAcP. However, IL-1α and IL-1β exert differential actions. A recent CNS-specific IL-1 receptor accessory protein, called IL-1RAcPb, has been characterised but its actions are unknown. In T cell line, over expression of IL-1RAcPb negatively regulate IL-1 action (Smith et al, 2009), but over-expression of IL-1RAcPb in HEK cell line induces IL-1 signaling (Lu et al, 2008). The role of IL-1RAcPb has not been studied in primary cells. The aim of this project was to investigate the role of IL-1RAcPb in IL-1-induced actions in neurones and glia, and to determine IL-1α and IL-1β differential actions in these two cell types. The role of IL-1RAcPb in IL-1-induced protein expression and IL 1α and IL-1β differential effects were investigated by treating WT and IL 1RAcPb-/- neurones and glia with IL-1α or IL-1β in the presence or absence of IL-1RA for 24 h followed by assessment of IL-6 induction by ELISA. The mechanism of IL-1RAcPb actions were studied by examining the effects of IL-1α or IL-1β on p38, ERK1/2 and Src kinase activation in neurones and glia by Western blot analysis. SB203580 (p38 inhibitor), UO126 (ERK1/2 inhibitor), and PP2 (Src kinase inhibitor) were used to determine the contribution of p38, ERK1/2 and Src kinase activation to IL-1-induced IL-6 synthesis in neuronal cultures. In WT neurones, IL-1α and IL-1β were equipotent at inducing IL-6 synthesis and p38 activation, whilst both ligands failed to induce ERK1/2 or Src kinase activation. In IL-1RAcPb-/- neurones, IL-1α and IL-1β induced similar levels of IL-6, but IL-1β was more potent than IL-1α at inducing p38 activation. IL-1α-induced p38 activation was reduced in IL-1RAcPb-/- neurones compared to WT neurones. In contrast to WT neurones, ERK1/2 was activated in IL-1RAcPb-/- neurones in response to IL-1α, whilst Src kinase was not activated by IL-1α or IL 1β. IL-1-induced IL-6 synthesis was abolished by IL-1RA, SB203580, UO126 and PP2. Interestingly PP2, a specific Src kinase inhibitor also partially inhibited basal ERK1/2 activity. In WT glial cells, IL-1α was more potent than IL-1β at inducing IL-6 synthesis but both cytokines induced ERK1/2 activation with equal potency. In IL-1RAcPb-/- glia, IL-1α and IL-1β were equally potent at inducing IL-6 synthesis and ERK1/2 activation. However, IL-α-induced-IL-6 synthesis was reduced in IL 1RAcPb-/- glia compared to WT glia. In both WT and IL-1RAcPb-/- glia, IL-1α and IL-1β induced p38 activation but not Src kinase activation . In conclusion, this study showed that in neurones, IL-1RAcPb may contribute to IL-1α-induced p38 activation but negatively regulates IL-1-induced ERK1/2 activation, therefore IL-1RAcPb may have specific effects on different signalling pathways. The effect of IL-1RAcPb could also be cell specific, as IL 1RAcPb contributed to IL-1α-induced p38 signalling in neurones but IL-6 production in glia. The role of IL-1RAcPb remains largely unknown and more investigations are required to elucidate its role in IL-1 signalling in the brain.

No description available.

No description available.

Cardiovascular diseases (CVD) are the leading cause of morbidity and mortality in the United States. It is also well recognized that the incidence of CVD is substantially increased in postmenopausal women due to the loss of estrogen. Experimental and clinical data support vascular protective effects of estrogen by various mechanisms. However, administration of estrogen is also associated with an increased incidence of heart disease which limits its therapeutic potential. Given the demonstrated risks of conventional estrogen therapy, a search for novel, cost-effective, alternative vasoactive agents for prevention of CVD is of major importance in the effort to decrease the burden of CVD morbidity. Genistein, a major soy isoflavone, may be one of those alternative agents because of its selective affinity to estrogen receptor-beta and various beneficial effects on CVD. However, the mechanism of the cardioprotective effects of genistein is still unclear. The objectives of this study were (1) to investigate the effect of genistein on the expression of endothelial nitric oxide synthase (eNOS) both in vitro and in vivo; (2) to define the mechanism by which genistein regulates eNOS expression; and, (3) to examine whether genistein protects against tumor necrosis factor-alpha (TNF-α)-induced apoptosis in human aortic endothelial cells (HAECs). The results demonstrated that genistein, at physiologically achievable concentrations (1-10 μM) in individuals consuming soy products, enhanced the expression of eNOS protein and subsequently elevated nitric oxie (NO) synthesis in both HAECs and human umbilical vein endothelial cells, concomitant with the increased eNOS mRNA expression (2.6-fold of control) and eNOS promoter activity, suggesting that genistein activates eNOS transcription. Furthermore, dietary supplementation of genistein to spontaneously hypertensive rats restored aortic eNOS levels, improved aortic wall thickness, and alleviated hypertension, confirming the biological relevance of the in vitro findings. However, the effects of genistein on eNOS and NO were not mediated by activation of estrogen signaling, mitogen-activated protein kinase, phosphatidylinositol 3-kinase/Akt kinase, protein kinase C or inhibition of typrosine kinases, but possibly through activating the cAMP/protein kinase A/cAMP responsive elemant binding protein pathway. These data suggest that genistein has direct genomic effects on the vascular wall that are unrelated to its known actions, leading to increase in eNOS expression and NO synthesis, thereby improving vascular homeostasis. We also found that genistein (5-10 μM) significantly inhibited TNF-α-induced apoptosis in HAECs as determined by caspase-3 activation, apoptotic cell detection and DNA laddering. The anti-apoptotic effect of genistein was associated with an enhanced expression of anti-apoptotic Bcl-2 protein and its promoter activity that was ablated by TNF-α. Moreover, this anti-apoptotic effect of genistein was not mediated by extracellular signal-regulated kinase 1/2, protein kinase A, or estrogen receptor. However, inhibition of p38 mitogen-activated protein kinase (p38) by SB203580 completely abolished the cytoprotective effect of genistein, suggesting that genistein acted through the p38-dependent pathway. Accordingly, stimulation of HAECs with genistein resulted in rapid and dose-dependent activation of p38. Unlike TNF-α which specifically activated p38α, genistein selectively induced phosphorylation of p38β, suggesting that p38β, but not p38α, is essential for the cytoprotective effect of genistein. These findings provide the evidence that genistein acts as a survival factor for vascular ECs to protect cells against apoptosis via activation of p38β. Taken together, the resuls of the present study suggest that genistein can act directly on vascular ECs, improves endothelium homeostasis by promoting eNOS expression and endothelial-derived NO synthesis through activating the cAMP/PKA/CREB cascade, and protects against TNF-α-induced apoptosis via activation of p38 β. These data potentially provide a basic mechanism underlying the physiological effects of genistein in the vasculature. / Ph. D.