<p> Asthmatic human airway smooth muscle cells (hASMCs) exhibit enhanced expression of numerous cytokine-responsive genes but this trend has not been observed for cyclooxygenase-2 (COX-2) expression despite knowledge that conserved regulatory mechanisms exist for cytokine-responsive gene expression. Enhanced expression of cytokine-responsive genes in asthmatic hASMCs has been attributed to differences in histone post-translational modifications and microRNA (miR or miRNA) expression. COX-2 expression is of interest because it serves as a model cytokine-responsive gene and is regulated by epigenetic mechanisms. In other cell types, miR-146a represses COX-2 and Interleukin (IL)-1&beta; expression, directly and indirectly, respectively. Due to sequence homology, miR-146b is predicted to repress the expression of COX-2 and IL-1&beta;. I investigated COX-2 expression in asthmatic and non-asthmatic hASMCS treated with cytomix (IL-1&beta;, tumor necrosis factor (TNF)-&alpha;, and interferon (IFN)-&gamma;). Also, I chose to compare histone acetylation, transcription factor binding, and miR-146a/b expression in asthmatic and non-asthmatic hASMCs to identify any correlations with COX-2 expression. A major goal of this project was to help identify new treatment targets for asthma therapeutics . I hypothesized that asthmatic hASMCs treated with cytomix express more COX-2 and secrete more prostaglandinE2 (PGE2) than non-asthmatic hASMCs due to differences in COX-2 epigenetic regulation. It is reported here that asthmatic hASMCs treated with cytomix expressed more COX-2 (mRNA/protein), and secreted more PGE2 than non-asthmatic hASMCs. Histone H3/H4 pan-acetylation at the COX-2 promoter did not increase with cytomix treatment and was not different in asthmatic and non-asthmatic hASMCs. Treatment of hASMCs with cytomix increased RNA Polymerase II and nuclear factor-&kappa;B binding at the COX-2 promoter with no difference between asthmatic and non-asthmatic hASMCs. Treatment of hASMCs with cytomix increased miR-146a and miR-146b expression with greater miR-146a expression in asthmatic. MiR-146a/b expression in asthmatic hASMCs treated with cytomix did not negatively correlate with COX-2 expression. These results led me to investigate whether miR-146a/b were capable of negatively regulating COX-2 and IL-1&beta; expression in hASMCs. MiR-146a and miR-146b mimics reduced COX-2 and IL-1&beta; mRNA/protein, and PGE2 secretion in hASMCs. MiR-146a and miR-146a/b combination inhibition increased COX-2 and pro-IL-1&beta; protein in hASMCs but not miR-146b inhibition alone. In conclusion, elevated miR-146a expression and histone acetylation are not responsible for increased COX-2 expression in asthmatic hASMCs. MiR-146a is a minor negative regulator of COX-2 and IL-1&beta; expression in hASMCs at physiological expression levels but mimics are capable of antagonizing cytokine-responsive gene expression profoundly. These results coupled with other evidence from the literature indicate that miR-146a/b should be investigated in animal models of asthma to determine if they are relevant asthma drug target in patients that do not respond to current anti-inflammatory therapies.</p>

Thesis (Ph.D.)--Indiana University, Dept. of Biology, 2007. / Source: Dissertation Abstracts International, Volume: 68-09, Section: B, page: 5744. Adviser: Mark Estelle. Title from dissertation home page (viewed May 9, 2008).

Thesis (Ph.D.)--University of Hawai'i at Manoa, 2005. / (UnM)AAI3198363. Source: Dissertation Abstracts International, Volume: 66-12, Section: B, page: 6430. Chair: Dulal Borthakur.

Thesis (Ph.D.)--University of California, San Francisco, 2005. / Source: Dissertation Abstracts International, Volume: 66-12, Section: B, page: 6537. Adviser: Frank McCormick.

Thesis (Ph.D.)--University of California, San Francisco, 2006. / Source: Dissertation Abstracts International, Volume: 68-01, Section: B, page: 0119. Adviser: Arturo Alvarez-Buylla.

Thesis (Ph.D.)--Indiana University, Dept. of Biology, 2007. / Title from home page (viewed Nov. 14, 2008). Source: Dissertation Abstracts International, Volume: 68-09, Section: B, page: 5708. Adviser: William Saxton.

Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2007. / Source: Dissertation Abstracts International, Volume: 68-06, Section: B, page: 3581. Advisers: Esmail Meisami; Philip Best. Includes bibliographical references (leaves 98-117) Available on microfilm from Pro Quest Information and Learning.

Thesis (Ph.D.)--University of California, San Francisco, 2007. / Source: Dissertation Abstracts International, Volume: 68-07, Section: B, page: 4220. Adviser: Thomas B. Kornberg.

Thesis (Ph.D.)--University of California, San Francisco, 2007. / Source: Dissertation Abstracts International, Volume: 68-11, Section: B, page: 7115. Adviser: Joseph DeRisi.

Thesis (Ph. D.)--University of California, San Francisco, 2008. / Source: Dissertation Abstracts International, Volume: 69-02, Section: B, page: 0782. Adviser: Jonathan S. Weissman.