Thesis (Ph. D.)--University of Sydney, 2008. / Title from title screen (viewed Apr. 27, 2009) Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the Discipline of Oral Pathology and Oral Medicine, Faculty of Dentistry. Degree awarded 2008; thesis submitted 2007. Includes bibliography. Also available in print form.

Thesis (M. Phil.)--University of Hong Kong, 2008. / Includes bibliographical references (leaves 75-100) Also available in print.

Thesis (M. Phil.)--University of Hong Kong, 2008. / Includes bibliographical references (leaves 75-100) Also available online.

Thesis (Ph. D.)--University of Nebraska Medical Center, 1999. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (M.S.)--University of Tennessee Health Science Center, 2009. / Title from title page screen (viewed on August 5, 2009). Research advisor: David A. Tipton, D.D.S., Ph.D. Document formatted into pages (vi, 39 p. : ill.). Vita. Abstract. Includes bibliographical references (p. 27-38).

Thesis (Ph. D.)--University of Nebraska Medical Center, 1999. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

A relação entre bacteriófagos e virulência bacteriana é um modelo muito intrigante e pouco estudado na patogênese periodontal, uma vez que um patógeno periodontal pode ser lisogênico. O objetivo do nosso estudo é determinar a capacidade de fibroblastos gengivais humanos de induzir as cepas lisogênicas de Aggregatibacter actinomycetemcomitans. Dois experimentos foram realizados seguidos da titulação de fago. Os experimentos consistiram da co-cultura com fibroblastos gengivais humanos e três cepas de Aa [Aa29524, Aa2112, Aa29524(Ø2112)], não lisogênica, lisogênica e lisogênica induzida em laboratório, respectivamente. Em três momentos distintos (no experimento 1: 0, 2 e 4 horas; e no experimento 2: 2, 4 e 6 horas), o sobrenadante da co-cultura foi filtrado e cultivado overnight com a bactéria indicadora (Aa29524) e analisado para a capacidade de lisar a célula indicadora. Em ambos os experimentos, o sobrenadante da co-cultura de fibroblastos gengivais humanos com Aa lisogênico e Aa lisogênico induzido em laboratório, ao ser cultivado com a bactéria indicadora, promoveu lise da mesma, resultando no aumento da produção de fago. Pode-se concluir que, nesse estudo os fibroblastos gengivais humanos foram capazes de induzir cepas lisogênicas de Aggregatibacter actinomycetemcomitans. / The relationship between bacteriophages and bacterial virulence is a very intriguing, but rarely studied model in periodontal pathogenesis, as a periodontal pathogens can be lysogenic. The aim of our study is to determine the ability of human gingival fibroblasts to induce lysogenic strains of Aggregatibacter actinomycetemcomitans. Two experiments were performed followed by titration of phage. The experiments consisted of co-culture with human gingival fibroblasts and three strains of Aa [Aa29524, Aa2112, Aa29524 (Ø2112)], not lysogenic, lysogenic and lysogenic induced in the laboratory, respectively. In three different times (in experiment 1: 0, 2 and 4 hours, and in experiment 2: 2, 4 and 6 hours), the co-culture supernatant was filtered and cultured overnight with the indicator strain (Aa29524) and analyzed for ability to lyse the cell indicator. In both experiments, the supernatant of the co-culture of human gingival fibroblasts with Aa lysogenic and Aa lysogenic induced in the laboratory to be cultured with the indicator bacteria, caused lysis of the same, resulting an increased phage production. It can be concluded that in this study, human gingival fibroblasts were able to induce lysogenic strains of Aggregatibacter actinomycetemcomitans.

According to the Centers for Disease Control, cancer is one of the leading causes of death in the United States. Characterized as a disease that develops as a result of an unstable genome, cancer is known to arise from numerous spontaneous mutations in the DNA of cells. Recent evidence shows that cancer cells within tumors are not self-reliant; rather, they progress along with other cells in their surrounding environment. Tumor cells recruit neighboring cells that, like the cancer cells, also become deregulated, forming the tumor stroma that aids in tumor progression. Within the stroma, cancer-associated fibroblasts (CAFs) play a vital role in the progression of cancer. Recent studies have found an important link between increased matrix stiffness surrounding the tumor and the invasion of the tumor. Thus, it is proposed that as the matrix stiffens, the tumor takes on more aggressive phenotypes. The transcriptional regulators YAP and TAZ (YAP/TAZ), key effectors of the Hippo pathway, are known to respond and influence matrix stiffening. In stiff matrix environments YAP/TAZ accumulate in the nucleus, and can drive transcriptional events. CAF's from late stage breast cancers have been found to exhibit increased YAP expression and increased ability to remodel and stiffen the extracellular matrix. Whether YAP or TAZ in these CAFs influences the metastatic properties of tumor cells is unclear. The present study aims to establish a link between YAP/TAZ activity in CAFs and cancer migration and invasion. We hypothesized that high nuclear activity of YAP/TAZ in fibroblasts would lead to non-autonomous signals that increase epithelial migration, and conversely that signals originating from epithelial cells affect YAP regulation in fibroblasts. We obtained CAFs from oral squamous cell carcinomas (OSCC) at various stages, and interestingly found that when CAFs obtained from stage III and stage IV tumors were co-cultured with OSCC cells they had the ability to cause OSCC cell migration. This CAF-induced migration was dependent on YAP/TAZ in the CAFs, as YAP/TAZ knockdown repressed this crosstalk. To gain insight into the mechanisms driving this process, transwell migration assays were conducted using NIH-3T3 fibroblasts engineered to overexpress YAP, or mutants of YAP, in doxycycline-inducible manner. We found that expression of YAP in NIH-3T3 cells, particularly a nuclear-localized YAP mutant, promoted the ability for OSCC cells to migrate in co-culture experiments. Media conditioned from these cells was sufficient to recapitulate this phenotype, suggesting that secreted factors from these fibroblasts may act as a signal that promotes migration. This activity of YAP was dependent on the ability for YAP to bind to the TEAD transcription factors, a major mediator of YAP transcriptional activity. Together these results indicate that nuclear YAP activity in fibroblasts can modulate the migration of neighboring cancer cells, suggesting that YAP plays a key role in stroma-cancer crosstalk during cancer progression.

Background. The Cysteine-rich protein, Connective tissue growth factor, and Nephroblastoma overexpressed protein (CCN) family of matricellular proteins are signaling molecules found in the extracellular space, which can have pro-angiogenic, anti-inflammatory and anti-fibrotic properties. Their expression and role in repair and remodeling after myocardial infarction (MI) remains to be better elucidated. In this study, the age-associated expression of Nov (CCN3) and Wisp1 (CCN4) were examined post-MI in mice. Methods and Results. In vivo, MI was induced in young (6 week) and old (12-14 months) mice. Cardiac function was assessed by echocardiography, showing that LVEF was reduced in old mice (33.9%) at 14 days post-MI compared to young mice (43.9%; p=0.002). RT-qPCR analysis of harvested myocardial tissue revealed that mRNA expression of several matricellular proteins in healthy tissue was decreased by 2.5- to 5-fold in old compared to young mice (p=0.03 for Nov, p=0.04 for Wisp1, p=0.0002 for TnC, p=0.04 for TSP-1). Post-MI, mRNA expression of Nov was reduced in the infarct (by up to 13-fold; p<0.03) and border zone (by up to 16-fold; p<0.002) in old compared to young mice. Nov and Wisp1 protein expression was also reduced in old compared to young mice in the infarct and border zones; specifically, for Nov in the infarct zone (p=0.01) and the border zone (p=0.009) at 2 days post-MI and for Wisp1 in the infarct zone at 2 days (p=0.0003) and 14 days (p=0.003), along with 7 days post-MI in the border zone (p=0.0003). To identify possible sources of matricellular proteins, in vitro culture experiments were performed. The expression of Nov protein was increased (1.9-fold; p=0.006) in TGF-B stimulated cardiac fibroblasts after 48h, as was the expression of the myofibroblast marker a-SMA (1.7-fold; p=0.035). Wisp1 mRNA expression was increased (4.5-fold; p=0.03) in stimulated cardiac fibroblasts after 48h in a hypoxic environment. There was also a trend for increased mRNA expression of Nov (p=0.118) and Wisp1 (p=0.121) in M2 macrophages. Cardiac fibroblasts treated with Nov+TGF-B exhibited greater proliferation (by 29%; p0.01), as did those treated with Wisp1+TGF-B (by 16%; p<0.05). Treatment with Nov or Wisp1 led to an increase in viability of cardiac fibroblasts both in the presence (Nov; p=0.0004, Wisp1; p=0.01) and absence of TGF-B (Nov; p=0.0005, Wisp1; p=0.003). Summary. There is an age-associated difference in the expression of matricellular proteins Nov and Wisp1 between both healthy and MI mice. In vitro studies suggest that cardiac fibroblasts may produce Nov and Wisp1 upon their activation to myofibroblasts. The presence of these proteins was also shown to increase the proliferation and viability of fibroblasts. Therefore, reduced levels of Nov and Wisp1 in old mice may negatively affect the repair and remodeling process post-MI compared to young mice. A better understanding of Nov and Wisp1 function in aging and post-MI repair may help identify novel therapeutic targets for limiting damage post-MI and improving repair and heart function.

A relação entre bacteriófagos e virulência bacteriana é um modelo muito intrigante e pouco estudado na patogênese periodontal, uma vez que um patógeno periodontal pode ser lisogênico. O objetivo do nosso estudo é determinar a capacidade de fibroblastos gengivais humanos de induzir as cepas lisogênicas de Aggregatibacter actinomycetemcomitans. Dois experimentos foram realizados seguidos da titulação de fago. Os experimentos consistiram da co-cultura com fibroblastos gengivais humanos e três cepas de Aa [Aa29524, Aa2112, Aa29524(Ø2112)], não lisogênica, lisogênica e lisogênica induzida em laboratório, respectivamente. Em três momentos distintos (no experimento 1: 0, 2 e 4 horas; e no experimento 2: 2, 4 e 6 horas), o sobrenadante da co-cultura foi filtrado e cultivado overnight com a bactéria indicadora (Aa29524) e analisado para a capacidade de lisar a célula indicadora. Em ambos os experimentos, o sobrenadante da co-cultura de fibroblastos gengivais humanos com Aa lisogênico e Aa lisogênico induzido em laboratório, ao ser cultivado com a bactéria indicadora, promoveu lise da mesma, resultando no aumento da produção de fago. Pode-se concluir que, nesse estudo os fibroblastos gengivais humanos foram capazes de induzir cepas lisogênicas de Aggregatibacter actinomycetemcomitans. / The relationship between bacteriophages and bacterial virulence is a very intriguing, but rarely studied model in periodontal pathogenesis, as a periodontal pathogens can be lysogenic. The aim of our study is to determine the ability of human gingival fibroblasts to induce lysogenic strains of Aggregatibacter actinomycetemcomitans. Two experiments were performed followed by titration of phage. The experiments consisted of co-culture with human gingival fibroblasts and three strains of Aa [Aa29524, Aa2112, Aa29524 (Ø2112)], not lysogenic, lysogenic and lysogenic induced in the laboratory, respectively. In three different times (in experiment 1: 0, 2 and 4 hours, and in experiment 2: 2, 4 and 6 hours), the co-culture supernatant was filtered and cultured overnight with the indicator strain (Aa29524) and analyzed for ability to lyse the cell indicator. In both experiments, the supernatant of the co-culture of human gingival fibroblasts with Aa lysogenic and Aa lysogenic induced in the laboratory to be cultured with the indicator bacteria, caused lysis of the same, resulting an increased phage production. It can be concluded that in this study, human gingival fibroblasts were able to induce lysogenic strains of Aggregatibacter actinomycetemcomitans.