Thesis (M.Sc.), Memorial University of Newfoundland, Faculty of Medicine,1999. / Typescript. Bibliography: leaves 100-118.

Diss. (sammanfattning) Stockholm : Karol. inst., 2005. / Härtill 5 uppsatser.

Master of Science / Department of Anatomy and Physiology / Lei Wang / Jishu Shi / Transforming growth factor beta (TGF-β) and interleukin-1β (IL-1β) are both up-regulated in high grade gliomas and their elevated activities have been associated with prognosis in glioma patients. It is known that TGF-β is involved in proliferation and maintenance of glioma stem cells. In this study, I evaluated whether IL-1β also plays an important role in glioma stem cell development. Glioma stem cells are usually identified by using a sphere assay where glioma stem cells proliferate as neurospheres in serum free medium (SFM) in the presence of two growth factors: EGF and bFGF. However, LN229, a human glioblastoma cell line does not form neurospheres in SFM, suggesting that LN229 cells contain very few stem cells. I found that combination of IL-1β and TGF-β, but not IL-1β or TGF-β alone induced LN229 cells to grow as neurospheres in SFM. Furthermore, quantitative RT-PCR analyses show that the expression of stem cell markers (Nestin, Bmi1, Notch2, and LIF), cytokines (IL-1β, IL-6 and IL-8) and invasive genes (SIP1, β-integrin and N-Cadherin) are significantly enhanced in IL-1β /TGF-β induced spheres compared to the control. Using an invasion assay, drug resistance test, and colony assay, I found that LN229 sphere cells induced by IL-1β and TGF-β are more invasive, have increased drug resistant ability, and are more oncogenic in comparison to the control. Together, these results suggest that IL-1β cooperates with TGF-β to induce glioma stem-like cell phenotype.

No description available.

Inflammatory bone diseases like rheumatoid arthritis and periodontal disease lead to increased bone loss in the inflamed areas. The multinucleated bone resorbing cells, the osteoclasts, present in these diseases are larger than normal, and these larger osteoclasts (10+ nuclei) resorb more bone and more often than smaller osteoclasts (2-5 nuclei). Thus, the focus of this thesis was to determine if there are differences in mechanisms of osteoclast activation between large and small osteoclasts. Experiments using authentic rabbit osteoclasts and RAW 264.7-derived osteoclasts revealed differences in the expression of a number of activating factors; with large osteoclasts expressing higher levels of activating receptors (RANK, IL-1RI, TNFR1 and integrins αv and β3), as well as enzymes involved in cellular resorption, while small osteoclasts expressed higher levels of an alleged fusion receptor and the inhibitory receptor, IL-1RII. Further studies revealed that large osteoclasts more readily responded to stimulation by IL-1 compared to small osteoclasts and at lower concentrations suggesting this is a result of their higher expression of activating receptors. Differences in responses to the IL-1 isoforms, IL-1α and IL-1β, were also seen in large osteoclasts: IL-1α generated more large osteoclasts over the course of differentiation, while IL-1β induced changes in cell morphology and in the induction of integrin β3 phosphorylation. These observations suggested that differences in osteoclast responses are induced by IL-1α and IL-1β and it led to the hypothesis that there are differences in signaling between large and small osteoclasts. To elucidate differences in signaling mechanisms a signaling pathway microarray was used which revealed higher expression of Vegfa in large compared to small osteoclasts. Osteoclast differentiation with RANKL increased Vegfa gene expression in a time-dependent manner and VEGF-A secretion was elevated in populations enriched for large osteoclasts. Furthermore, mechanistic studies with inhibitors of transcription factors involved in differentiation revealed that RANKL-mediated Vegfa expression in large osteoclasts was regulated by the NF-κB pathway via induction of Hif1α. These results support the hypothesis that signaling differences exist between large and small osteoclasts and implicates VEGF-A in osteoclast hyperactivity in inflammatory conditions.

No description available.

Graduation date: 2000

Abstract The members of interleukin-1 (IL-1) gene family, interleukin-1£] (IL-1b) and Interleukin -1 receptor antagonist (IL-l RN) are cytokines that play a key role in modulating the inflammatory response in the gastrointestinal mucosa. IL-1£]

Zugl.: Berlin, Humboldt-Univ., Diss., 2009

Thesis (Ph. D.)--University of Texas at Austin, 1999. / Vita. Includes bibliographical references (leaves 178-199). Available also in a digital version from Dissertation Abstracts.