by Hiu Wong. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1991. / Includes bibliographical references. / SUMMARY --- p.1 / INTRODUCTION --- p.4 / LITERATURE REVIEW --- p.8 / Chapter I. --- Nasopharyngeal carcinoma (NPC) --- p.8 / Chapter A. --- Epidemiology of NPC --- p.8 / Chapter B. --- Anatomy of NPC --- p.11 / Chapter C. --- Pathology of NPC --- p.12 / Chapter D. --- Histological classification of NPC --- p.14 / Chapter E. --- Stage classification of NPC --- p.15 / Chapter F. --- Clinical feature of NPC --- p.18 / Chapter G. --- Diagnosis of NPC --- p.19 / Chapter (a) --- Clinical examination / Chapter (b) --- Radiographic examination / Chapter (c) --- Laboratory examination / Chapter (d) --- Biopsy examination / Chapter H. --- Treatment of NPC --- p.21 / Chapter (a) --- Surgery / Chapter (b) --- Chemotherapy / Chapter (c) --- Radiotherapy / Chapter I. --- Prognosis of NPC --- p.23 / Chapter J. --- Etiology of NPC --- p.24 / Chapter (a) --- Dietary factor / Chapter (b) --- Genetic factor / Chapter (c) --- Environmental factor / Chapter (d) --- EBV infection / Chapter (e) --- Others / Chapter II. --- Beta-2 Microglobulin (B2M) --- p.30 / Chapter A. --- Structure and function of B2M --- p.30 / Chapter B. --- Clinical chemistry of B2M --- p.33 / Chapter C. --- B2M and its relationship to immunogenetic system --- p.34 / Chapter D. --- B2M in solid malignancies --- p.35 / Chapter E. --- B2M in hematologic malignancies --- p.36 / Chapter F. --- B2M in non-malignant diseases --- p.38 / Chapter III. --- Epstein - Barr Virus (EBV) --- p.41 / Chapter A. --- Morphology / Chapter B. --- EBV infection --- p.42 / Chapter C. --- EBV and Nasopharyngeal Carcinoma --- p.44 / Chapter D. --- Relationship of EBV to other human disease --- p.46 / Chapter (a) --- The relationship of EBV to IM / Chapter (b) --- The relationship of EBV to BL / Chapter E. --- EBV genome-carrying lymphoid cell lines --- p.50 / Chapter IV. --- TUMOUR ANTIGEN OF SQUEMOUS CELL CARCINOMA --- p.55 / Chapter A. --- The source of TA-4 --- p.55 / Chapter B. --- Characteristics of TA-4 --- p.56 / Chapter C. --- TA-4 in squamous cell carcinoma of uterine cervix --- p.57 / Chapter D. --- TA-4 in other type of squamous cell carcinaoma --- p.58 / MATERIALS AND METHODS / Chapter A. --- Materials --- p.61 / Chapter B. --- Measurement of Beta-2 Microglobulin --- p.63 / Chapter (a) --- Principles / Chapter (b) --- Assay protocol / Chapter (c) --- Reproducibility / Chapter C. --- Detection of EBV antibody titres in human sera --- p.68 / Chapter (a) --- Induction of EA/VCA in Raji/P3HR-1 cell lines / Chapter (b) --- Detection of antibody titres to EA/VCA in human sera / Chapter D. --- Measurement of squamous cell carcinoma associated antigen --- p.75 / RESULTS --- p.79 / Chapter A. --- Diurnal change of serum B2M or TA-4 level --- p.79 / Chapter B. --- The B2M and TA-4 levels in apparently healthy people --- p.81 / Chapter C. --- The usefullness of assay in initial diagnosis and staging --- p.81 / Chapter (a) --- Correlation between serum B2M levels and staging of NPC / Chapter (b) --- Correlation between serum TA-4 levels and staging of NPC / Chapter D. --- Correlation between histological differentiation of NPC and B2M and TA-4 level --- p.91 / Chapter E. --- The usefulness of assay for monitoring the NPC --- p.93 / Chapter (a) --- patients achieved completed remission / Chapter (b) --- patients developed local recurrence / Chapter (c) --- patients developed distant metastases / DISCUSSION --- p.131 / Chapter A. --- Serum B2M in NPC patients --- p.131 / Chapter B. --- Serum TA-4 in NPC ptients --- p.136 / Chapter C. --- EBV antibody titres in NPC patients --- p.137 / Chapter D. --- Conclusion --- p.141 / Chapter E. --- Suggested further study --- p.143 / REFERENCES --- p.146

Thesis (Ph.D.)--Indiana University, 2008. / Title from screen (viewed on June 2, 2009). Department of Pathology & Laboratory Medicine, Indiana University-Purdue University Indianapolis (IUPUI). Advisor(s): Stephen D. Allen. Includes vita. Includes bibliographical references (leaves 192-215).

Memoria para optar al título de Químico Farmacéutico / Los fibroblastos cardiacos son las principales células no contráctiles presentes en el miocardio. Su función principal es preservar la estructura y el buen funcionamiento cardiaco, lo cual se realiza a través de la síntesis y secreción de componentes de la matriz extracelular. Después de un daño tisular, los fibroblastos cardiacos son células claves, del proceso reparativo y de cicatrización. Si este proceso se exacerba, se llega a fibrosis cardiaca rigidizando el corazón e incrementando el riesgo de arritmias, alterando fuertemente la función cardiaca. En este sentido, se ha demostrado que el aumento de AMPc, contribuye a disminuir el grado de fibrosis cardíaca, por regulación de procesos tales como adhesión, migración, secreción de colágeno y la diferenciación celular. En fibroblastos cardiacos se ha descrito que isoproterenol, un agonista de los receptores β-adrenérgicos, actúa vía Gs y estimula la producción de AMPc. Por otro lado, BK agonista del receptor B2 de cininas, activa su receptor vía Gq, y por sí mismo, no altera la producción de AMPc. Sin embargo, BK en combinación con isoproterenol potencia la respuesta adrenérgica aumentando de manera sinérgica la producción de AMPc en relación a la activación solo por isoproterenol. El objetivo de este trabajo fue estudiar in vitro, en cultivos primaros de fibroblastos cardiacos de ratas neonatas, el cross-talk entre las vías de señalización Gs-Gq y determinar si el aumento en los niveles de AMPc modula la adhesión, migración, síntesis de colágeno y diferenciación en fibroblastos cardiacos. BK tiene un efecto sinérgico en los niveles de AMPc aumentados por isoproterenol. Del mismo modo, BK potencia la adhesión de fibroblastos cardiacos estimulada por Isoproterenol; sin embargo, BK no tiene efectos sobre la migración en los fibroblastos cardiacos inducida por isoproterenol. Por otro lado, BK e isoproterenol por separado disminuyen la síntesis de colágeno; sin embargo, la administración conjunta de ISO+BK induce una mayor disminución de la síntesis. El efecto sinérgico de BK sobre el aumento de AMPc inducido por ISO potencia la inhibición de la diferenciación celular de fibroblasto a miofibroblasto estimulada por TGF-β1. Finalmente, determinamos que el efecto sinérgico de BK sobre la señalización de ISO es gatillada vía Gq-PLC-CaMK-II, conduciendo al aumento sinérgico en la producción de AMPc / Cardiac fibroblasts are the major non-contractile cells present in the myocardium. Its main function is to preserve the structure and the proper functioning of the heart, which is done through the synthesis and secretion of extracellular matrix components. After tissue injury, cardiac fibroblasts are key cells of the reparative process and healing. If this process is exacerbated cardiac fibrosis is reached, stiffening the heart and increasing the risk of arrhythmia, altering strongly the heart function In this regard, it has been shown that the increase of cAMP, helps to reduce the degree of cardiac fibrosis, by regulating processes such as adhesion, migration, collagen secretion and cell differentiation. In cardiac fibroblasts has been reported that isoproterenol, an agonist of β-adrenergic receptors, acts via Gs and stimulates the production of cAMP. On the other hand, BK an agonist of B2 kinin receptor, activates its receptor Gq, and by itself does not alter cAMP production. However, in combination with isoproterenol enhances the adrenergic response, increasing the levels of cAMP in a synergistic manner, in relation to activation by isoproterenol alone. The aim of this work was to study in vitro, in cultured of neonatal rat cardiac fibroblasts, the cross-talk between signaling pathways Gs-Gq and determine if the increase in cAMP modulates adhesion, migration, collagen secretion and differentiation in cardiac fibroblasts. BK has a synergistic effect on cAMP levels increased by isoproterenol. Similarly, BK enhances the adhesion of cardiac fibroblasts stimulated by isoproterenol, but BK has no effect on migration in cardiac fibroblasts induced by isoproterenol. Furthermore, BK and isoproterenol separately decrease collagen synthesis, but the co-administration of ISO+ BK induces a greater decrease in the synthesis. The synergistic effect of BK in the cAMP levels induced by ISO, showed inhibit the cellular differentiation of fibroblasts into myofibroblasts stimulated by TGF-β1 Finally, we determined that the synergistic effect of BK on ISO signaling is triggered via Gq-PLC-CaMK-II, leading to the synergistic increase in cAMP production

Indiana University-Purdue University Indianapolis (IUPUI) / Clostridium perfringens is an important human pathogen known to cause a range of diseases including diarrhea, necrotizing bowel disease and gas gangrene. Though potentially pathogenic, this microorganism is commonly identified in the fecal microbiota of healthy individuals. The major clinical findings associated with C. perfringens diseases are linked to production of potent toxins. In 1997, Gibert et al. identified a new toxin, the beta2 toxin, from a C. perfringens strain from a piglet with necrotic enteritis. Subsequently, this new beta2 toxin gene (cpb2) has been identified in C. perfringens from dogs, horses, and other animals. The principal objective of this investigation was to study cpb2 and the beta2 toxin in C. perfringens isolates from human sources. The C. perfringens isolates were grouped into three different populations: 1) fecal samples from patients suspected of having C. perfringens gastrointestinal illnesses (e.g. antibiotic-associated diarrhea or colitis), 2) extraintestinal specimen sources (e.g. wounds, abscesses, blood cultures), 3) a control group of isolates from healthy volunteers. Results of studies using different PCR methods and nucleotide sequencing revealed that cpb2 was present in the genome of isolates from all populations, and that the genetic variation between cpb2 from the different C. perfringens isolates was greater then expected. Using western blotting techniques, it was found that the beta2 protein was not expressed by all cpb2 positive C. perfringens isolates. Finally, different variants of cpb2 were cloned into E. coli, and the recombinant beta2 protein used in cell cytotoxicity assays. Results from these assays demonstrated that recombinant beta2 proteins caused a range of cellular damage at different levels of protein concentration and different lengths of time. Our results from these experiments provided new information regarding cpb2 in C. perfringens isolates from human sources; as well as on the range of variation of cpb2 genes, differences in beta2 toxin expression, and differences in the effects of recombinant beta2 toxin on enterocytes. This information could help to explain differences in virulence between C. perfringens isolates, differences in diseases and disease severity.

A ativação do receptor beta 2 adrenérgico (β2-AR), pelos mediadores químicos do estresse, pode induzir efeitos estimuladores ou inibidores na migração e invasão celular, dependendo do tipo de tumor maligno. A importância deste receptor na evolução do câncer de boca não está totalmente esclarecida. O objetivo deste estudo foi verificar a expressão do β2-AR em linhagens de carcinomas espinocelular de boca (SCC-9 e SCC-25), e investigar o papel da ativação deste receptor pela norepinefrina e de seu bloqueio por um antagonista na migração e invasão destas células neoplásicas. As células SCC-9 e SCC-25 foram investigadas quanto à expressão gênica e proteica do β2-AR, respectivamente, pelo RT-qPCR e pelo Western blot. A migração e a invasão celular foram analisadas pelo ensaio de cicatrização de feridas e pelo sistema de câmeras de invasão Transwell, respectivamente. Diferentes concentrações (0,1; 1 e 10μM) de norepinefrina foram utilizadas para estimular e 1μM de propranolol foi empregado para bloquear os receptores beta adrenérgicos nas células neoplásicas. As diferenças das médias obtidas nos experimentos de invasão e migração de SCC-9 e SCC-25 e da expressão proteica do β2-AR, foram comparadas pelo teste t de Student com nível de significância de 5%. Os resultados mostraram que a expressão gênica e proteica do β2-AR foi verificada em ambas as linhagens de câncer de boca. A concentração de 10μM de norepinefrina inibiu, significativamente (p≤0,05), a migração e invasão celular de SCC-9 e SCC-25, sendo este efeito mais acentuado nas células SCC-25. Além disso, houve uma redução significativa (p≤0,05) do efeito da norepinefrina na migração celular quando os β2-AR foram inibidos pelo propranolol. Adicionalmente, o bloqueio dos β-ARs pelo propranolol reverteu parcialmente o efeito da norepinefrina na capacidade invasiva de SCC-9 e SCC-25. Estes resultados comprovam que a norepinefrina, via ativação do β2-AR, reduziu a migração e a invasão das células do carcinoma espinocelular de boca e, portanto, o uso de agonistas dos receptores beta-adrenérgicos poderia se tornar um alvo terapêutico adjuvante no tratamento desta neoplasia maligna. / The activation of beta 2 adrenergic receptor (β2-AR), by chemical mediators of stress, can induce stimulatory or inhibitory effects on cell migration and invasion, depending on the type of malignancy. The importance of this receptor in the oral cancer outcome is not fully understood. The aim of this study was to verify β2- AR expression in oral squamous cell carcinoma cell lines (SCC-9 and SCC-25), and to investigate the role of activation of this receptor by norepinephrine and its blockade by an antagonist in migration and invasion of these neoplastic cells. SCC-9 and SCC-25 cells were investigated for gene and protein expression of β2-AR, respectively, by RT-qPCR and Western blot. The cell migration and invasion were analyzed by wound healing assay and Transwell invasion camera system, respectively. Different concentrations (0.1, 1 and 10μM) of norepinephrine were used to stimulate and 1μM propranolol was used to block the beta adrenergic receptors on cancer cells. Differences in mean values of the invasion and migration assays of SCC-9 and SCC-25 and β2-AR protein expression were compared by the Student t test with 5% significance level. The results showed that β2-AR gene and protein expression was verified in both oral cancer cell lines. The concentration of 10μM of norepinephrine inhibited significantly (p≤0.05), cell migration and invasion of SCC-9 and SCC-25, being the most pronounced effect in SCC-25 cells. Furthermore, there was a significant reduction (p≤0.05) of norepinephrine effect on cell migration when the β2-AR was inhibited by propranolol. In addition, blockade of β-ARs by propranolol partially reversed the effect of norepinephrine on the invasiveness of SCC-9 and SCC-25. These results show that norepinephrine via β2-AR activation, reduced the migration and invasion of oral squamous cell carcinoma cells and, therefore, the use of beta-adrenergic receptors agonists could become an adjuvant therapeutic target in the treatment of this malignancy.

Os efeitos benéficos do exercício físico aeróbico (EFA) frente à prevenção e ao tratamento de doenças ocorrem por meio de adaptações agudas e crônicas em diversos tecidos e sistemas orgânicos, dentre os quais o tecido muscular esquelético assume papel de destaque. Considerando que a musculatura esquelética é rica em mitocôndrias, não surpreende o fato de que o aumento da capacidade e potência aeróbicas induzido pelo EFA ocorra principalmente em função das adaptações mitocondriais. Contudo, os mecanismos moleculares envolvidos nessas adaptações mitocondriais induzidas pelo EFA não são completamente compreendidos. Considerando-se que a atividade nervosa simpática aumenta consideravelmente durante a realização de uma sessão de EFA, parte das respostas mitocondriais ao EFA poderia ser mediada pela ativação dos receptores \'beta\'-adrenérgicos (\'beta\'-AR) na musculatura esquelética, representados predominantemente pelo subtipo \'beta\'2 (~ 90%). Com isso, na primeira parte do presente estudo, testou-se a hipótese de que a sinalização \'beta\'2-AR contribuiria para as respostas de função e dinâmica mitocondriais induzidas pela ativação adrenérgica aguda na musculatura esquelética. Para isso, o agonista \'beta\'-AR não seletivo isoproterenol foi administrado na presença ou ausência do antagonista \'beta\'2-AR específico, ICI 118,551, tanto em miotúbulos diferenciados a partir da linhagem de células C2C12 como em camundongos da cepa FVB. Os dados demonstraram que a ativação \'beta\'-AR aumentou significativamente a respiração mitocondrial em miotúbulos e em fibras musculares isoladas do músculo tibial anterior de camundongos, e que tal resposta foi dependente da ativação dos receptores \'beta\'2-AR via eixo proteína Gαs-AMPc-PKA. Em relação à dinâmica mitocondrial, os dados obtidos demonstraram que a ativação dos receptores \'beta\'2-AR aumentou a fusão mitocondrial na musculatura esquelética, e que esta resposta estava associada a um aumento da proteína de fusão Mfn1. Na segunda parte do presente estudo, testou-se a hipótese de que a ativação \'beta\'2-AR contribuiria para as respostas mitocondriais agudas induzidas pelo EFA na musculatura esquelética. Para isso, camundongos FVB foram submetidos a uma sessão de EFA em esteira rolante com e sem o bloqueio dos receptores \'beta\'2-AR com o antagonista ICI 118,551, e parâmetros de função e dinâmica mitocondriais foram avaliados. O EFA foi capaz de aumentar a respiração máxima mitocondrial em fibras musculares isoladas, e este efeito foi parcialmente prevenido pelo bloqueio dos receptores \'beta\'2-AR. Além disso, assim como observado com o tratamento com isoproterenol, o EFA promoveu aumento da fusão mitocondrial na musculatura esquelética, sendo que a ativação \'beta\'2-AR estava associada a essa resposta, porém em uma menor magnitude em relação aos efeitos observados com o estímulo farmacológico. Assim como observado no tratamento com isoproterenol, a expressão de Mfn1 foi aumentada pela sessão de EFA, a qual não foi atenuada pelo bloqueio dos receptores \'beta\'2-AR com ICI 118,551. Dessa forma, a partir dos resultados obtidos no presente estudo, pode-se concluir que os receptores \'beta\'2-AR têm papel importante no metabolismo muscular esquelético, modulando a função e a dinâmica mitocondriais. Essa resposta é evidente mediante ativação direta via agonistas \'beta\'-AR no músculo esquelético, no entanto, os receptores \'beta\'2-AR modulam parcialmente as respostas mitocondriais em resposta à uma sessão de EFA / The beneficial effects of aerobic exercise (AE) for prevention and treatment of diseases are due to acute and chronic adaptations in several organ systems, including skeletal muscle, one of the main tissues involved in these adaptations. Since skeletal muscle contains high amounts of mitochondria, the increased aerobic capacity induced by AE occurs mainly due to mitochondrial adaptations. However, the molecular mechanisms underlying skeletal muscle mitochondrial adaptations induced by AE are not fully understood. One of the mechanisms by which these mitochondrial adaptations may occur is sympathetic activation mediated by \'beta\'2-adrenergic receptors (\'beta\'-AR) in skeletal muscle, predominantly represented by \'beta\'2 subtype (~90%). Considering that sympathetic activity increases during AE, \'beta\'2-AR signaling might be involved in skeletal muscle mitochondrial adaptations in response to AE. Thus, in the first part of this study, we tested the hypothesis that acute \'beta\'2-AR activation contributes to mitochondrial function and dynamics adaptations in skeletal muscle. For this, both differentiated C2C12 myotubes and FVB mice were treated with the nonselective \'beta\'-AR agonist isoproterenol in the presence or absence of the specific \'beta\'2-AR antagonist, ICI 118,551. The data showed that β-AR activation significantly increased mitochondrial respiration in myotubes and muscle fiber bundles isolated from mice tibialis anterior, and that this response was dependent on \'beta\'2-AR receptors activation via protein G\' alpha\'s-cAMP-PKA signaling cascade. Regarding mitochondrial dynamics, the data showed that \'beta\'2-AR receptor activation increased mitochondrial fusion in skeletal muscle and that this response was associated to an increase in Mfn1. In the second part of this study, we tested the hypothesis that \'beta\'2-AR activation would contribute to acute mitochondrial responses induced by AE in skeletal muscle. For this, FVB mice underwent one session of AE on a treadmill with and without \'beta\'2-AR receptor blockade with ICI 118,551, and parameters of mitochondrial function and dynamics were evaluated. AE was able to increase maximal mitochondrial respiration in isolated muscle fibers, and this effect was partially prevented by blocking \'beta\'2-AR receptors. Furthermore, as observed with isoproterenol treatment, AE increased mitochondrial fusion in skeletal muscle. \'beta\'2-AR activation was associated with this response, but in a smaller magnitude compared to the effects observed with pharmacological stimulation. As observed with the isoproterenol treatment, Mfn1 expression was increased by AE, which was not attenuated by blocking \'beta\'2-AR receptors with ICI 118,551. Therefore, one can conclude that \'beta\'2-AR receptors play an important role in skeletal muscle metabolism, modulating mitochondrial function and dynamics. This response is evident by direct activation through \'beta\'-AR agonists in skeletal muscle, however, \'beta\'2-AR receptors partially modulate mitochondrial responses induced by AE

A ativação do receptor beta 2 adrenérgico (β2-AR), pelos mediadores químicos do estresse, pode induzir efeitos estimuladores ou inibidores na migração e invasão celular, dependendo do tipo de tumor maligno. A importância deste receptor na evolução do câncer de boca não está totalmente esclarecida. O objetivo deste estudo foi verificar a expressão do β2-AR em linhagens de carcinomas espinocelular de boca (SCC-9 e SCC-25), e investigar o papel da ativação deste receptor pela norepinefrina e de seu bloqueio por um antagonista na migração e invasão destas células neoplásicas. As células SCC-9 e SCC-25 foram investigadas quanto à expressão gênica e proteica do β2-AR, respectivamente, pelo RT-qPCR e pelo Western blot. A migração e a invasão celular foram analisadas pelo ensaio de cicatrização de feridas e pelo sistema de câmeras de invasão Transwell, respectivamente. Diferentes concentrações (0,1; 1 e 10μM) de norepinefrina foram utilizadas para estimular e 1μM de propranolol foi empregado para bloquear os receptores beta adrenérgicos nas células neoplásicas. As diferenças das médias obtidas nos experimentos de invasão e migração de SCC-9 e SCC-25 e da expressão proteica do β2-AR, foram comparadas pelo teste t de Student com nível de significância de 5%. Os resultados mostraram que a expressão gênica e proteica do β2-AR foi verificada em ambas as linhagens de câncer de boca. A concentração de 10μM de norepinefrina inibiu, significativamente (p≤0,05), a migração e invasão celular de SCC-9 e SCC-25, sendo este efeito mais acentuado nas células SCC-25. Além disso, houve uma redução significativa (p≤0,05) do efeito da norepinefrina na migração celular quando os β2-AR foram inibidos pelo propranolol. Adicionalmente, o bloqueio dos β-ARs pelo propranolol reverteu parcialmente o efeito da norepinefrina na capacidade invasiva de SCC-9 e SCC-25. Estes resultados comprovam que a norepinefrina, via ativação do β2-AR, reduziu a migração e a invasão das células do carcinoma espinocelular de boca e, portanto, o uso de agonistas dos receptores beta-adrenérgicos poderia se tornar um alvo terapêutico adjuvante no tratamento desta neoplasia maligna. / The activation of beta 2 adrenergic receptor (β2-AR), by chemical mediators of stress, can induce stimulatory or inhibitory effects on cell migration and invasion, depending on the type of malignancy. The importance of this receptor in the oral cancer outcome is not fully understood. The aim of this study was to verify β2- AR expression in oral squamous cell carcinoma cell lines (SCC-9 and SCC-25), and to investigate the role of activation of this receptor by norepinephrine and its blockade by an antagonist in migration and invasion of these neoplastic cells. SCC-9 and SCC-25 cells were investigated for gene and protein expression of β2-AR, respectively, by RT-qPCR and Western blot. The cell migration and invasion were analyzed by wound healing assay and Transwell invasion camera system, respectively. Different concentrations (0.1, 1 and 10μM) of norepinephrine were used to stimulate and 1μM propranolol was used to block the beta adrenergic receptors on cancer cells. Differences in mean values of the invasion and migration assays of SCC-9 and SCC-25 and β2-AR protein expression were compared by the Student t test with 5% significance level. The results showed that β2-AR gene and protein expression was verified in both oral cancer cell lines. The concentration of 10μM of norepinephrine inhibited significantly (p≤0.05), cell migration and invasion of SCC-9 and SCC-25, being the most pronounced effect in SCC-25 cells. Furthermore, there was a significant reduction (p≤0.05) of norepinephrine effect on cell migration when the β2-AR was inhibited by propranolol. In addition, blockade of β-ARs by propranolol partially reversed the effect of norepinephrine on the invasiveness of SCC-9 and SCC-25. These results show that norepinephrine via β2-AR activation, reduced the migration and invasion of oral squamous cell carcinoma cells and, therefore, the use of beta-adrenergic receptors agonists could become an adjuvant therapeutic target in the treatment of this malignancy.

Os efeitos benéficos do exercício físico aeróbico (EFA) frente à prevenção e ao tratamento de doenças ocorrem por meio de adaptações agudas e crônicas em diversos tecidos e sistemas orgânicos, dentre os quais o tecido muscular esquelético assume papel de destaque. Considerando que a musculatura esquelética é rica em mitocôndrias, não surpreende o fato de que o aumento da capacidade e potência aeróbicas induzido pelo EFA ocorra principalmente em função das adaptações mitocondriais. Contudo, os mecanismos moleculares envolvidos nessas adaptações mitocondriais induzidas pelo EFA não são completamente compreendidos. Considerando-se que a atividade nervosa simpática aumenta consideravelmente durante a realização de uma sessão de EFA, parte das respostas mitocondriais ao EFA poderia ser mediada pela ativação dos receptores \'beta\'-adrenérgicos (\'beta\'-AR) na musculatura esquelética, representados predominantemente pelo subtipo \'beta\'2 (~ 90%). Com isso, na primeira parte do presente estudo, testou-se a hipótese de que a sinalização \'beta\'2-AR contribuiria para as respostas de função e dinâmica mitocondriais induzidas pela ativação adrenérgica aguda na musculatura esquelética. Para isso, o agonista \'beta\'-AR não seletivo isoproterenol foi administrado na presença ou ausência do antagonista \'beta\'2-AR específico, ICI 118,551, tanto em miotúbulos diferenciados a partir da linhagem de células C2C12 como em camundongos da cepa FVB. Os dados demonstraram que a ativação \'beta\'-AR aumentou significativamente a respiração mitocondrial em miotúbulos e em fibras musculares isoladas do músculo tibial anterior de camundongos, e que tal resposta foi dependente da ativação dos receptores \'beta\'2-AR via eixo proteína Gαs-AMPc-PKA. Em relação à dinâmica mitocondrial, os dados obtidos demonstraram que a ativação dos receptores \'beta\'2-AR aumentou a fusão mitocondrial na musculatura esquelética, e que esta resposta estava associada a um aumento da proteína de fusão Mfn1. Na segunda parte do presente estudo, testou-se a hipótese de que a ativação \'beta\'2-AR contribuiria para as respostas mitocondriais agudas induzidas pelo EFA na musculatura esquelética. Para isso, camundongos FVB foram submetidos a uma sessão de EFA em esteira rolante com e sem o bloqueio dos receptores \'beta\'2-AR com o antagonista ICI 118,551, e parâmetros de função e dinâmica mitocondriais foram avaliados. O EFA foi capaz de aumentar a respiração máxima mitocondrial em fibras musculares isoladas, e este efeito foi parcialmente prevenido pelo bloqueio dos receptores \'beta\'2-AR. Além disso, assim como observado com o tratamento com isoproterenol, o EFA promoveu aumento da fusão mitocondrial na musculatura esquelética, sendo que a ativação \'beta\'2-AR estava associada a essa resposta, porém em uma menor magnitude em relação aos efeitos observados com o estímulo farmacológico. Assim como observado no tratamento com isoproterenol, a expressão de Mfn1 foi aumentada pela sessão de EFA, a qual não foi atenuada pelo bloqueio dos receptores \'beta\'2-AR com ICI 118,551. Dessa forma, a partir dos resultados obtidos no presente estudo, pode-se concluir que os receptores \'beta\'2-AR têm papel importante no metabolismo muscular esquelético, modulando a função e a dinâmica mitocondriais. Essa resposta é evidente mediante ativação direta via agonistas \'beta\'-AR no músculo esquelético, no entanto, os receptores \'beta\'2-AR modulam parcialmente as respostas mitocondriais em resposta à uma sessão de EFA / The beneficial effects of aerobic exercise (AE) for prevention and treatment of diseases are due to acute and chronic adaptations in several organ systems, including skeletal muscle, one of the main tissues involved in these adaptations. Since skeletal muscle contains high amounts of mitochondria, the increased aerobic capacity induced by AE occurs mainly due to mitochondrial adaptations. However, the molecular mechanisms underlying skeletal muscle mitochondrial adaptations induced by AE are not fully understood. One of the mechanisms by which these mitochondrial adaptations may occur is sympathetic activation mediated by \'beta\'2-adrenergic receptors (\'beta\'-AR) in skeletal muscle, predominantly represented by \'beta\'2 subtype (~90%). Considering that sympathetic activity increases during AE, \'beta\'2-AR signaling might be involved in skeletal muscle mitochondrial adaptations in response to AE. Thus, in the first part of this study, we tested the hypothesis that acute \'beta\'2-AR activation contributes to mitochondrial function and dynamics adaptations in skeletal muscle. For this, both differentiated C2C12 myotubes and FVB mice were treated with the nonselective \'beta\'-AR agonist isoproterenol in the presence or absence of the specific \'beta\'2-AR antagonist, ICI 118,551. The data showed that β-AR activation significantly increased mitochondrial respiration in myotubes and muscle fiber bundles isolated from mice tibialis anterior, and that this response was dependent on \'beta\'2-AR receptors activation via protein G\' alpha\'s-cAMP-PKA signaling cascade. Regarding mitochondrial dynamics, the data showed that \'beta\'2-AR receptor activation increased mitochondrial fusion in skeletal muscle and that this response was associated to an increase in Mfn1. In the second part of this study, we tested the hypothesis that \'beta\'2-AR activation would contribute to acute mitochondrial responses induced by AE in skeletal muscle. For this, FVB mice underwent one session of AE on a treadmill with and without \'beta\'2-AR receptor blockade with ICI 118,551, and parameters of mitochondrial function and dynamics were evaluated. AE was able to increase maximal mitochondrial respiration in isolated muscle fibers, and this effect was partially prevented by blocking \'beta\'2-AR receptors. Furthermore, as observed with isoproterenol treatment, AE increased mitochondrial fusion in skeletal muscle. \'beta\'2-AR activation was associated with this response, but in a smaller magnitude compared to the effects observed with pharmacological stimulation. As observed with the isoproterenol treatment, Mfn1 expression was increased by AE, which was not attenuated by blocking \'beta\'2-AR receptors with ICI 118,551. Therefore, one can conclude that \'beta\'2-AR receptors play an important role in skeletal muscle metabolism, modulating mitochondrial function and dynamics. This response is evident by direct activation through \'beta\'-AR agonists in skeletal muscle, however, \'beta\'2-AR receptors partially modulate mitochondrial responses induced by AE

Class of 2012 Abstract / Specific Aims: We sought to determine the influence of genetic variation of ADRB2 on the airway response to albuterol in patients with CF when compared to matched healthy controls at baseline and at 60 minutes following the administration of albuterol (2.5mg diluted in 3ml normal saline). Methods: Baseline pulmonary function (forced vital capacity, FVC, forced expiratory flow in 1-second, FEV1, mid-maximal expiratory flow, MMF, and forced expiratory flow at 50% of the FVC) was assessed in 17 patients with CF and 31 healthy subjects. Main Results: As expected, the healthy group had higher baseline pulmonary function when compared to the CF group (FVC=97±3 vs. 83±5; FEV1=95±3 vs. 72±6; MMF=90±4 vs. 54±8, % predicted for healthy and CF, respectively, mean±SE, p<0.05 for all. We compared Arg16Arg to Arg16Gly/Gly16Gly subjects. There was no effect of genotype on the response to albuterol in healthy subjects. However, in the CF group, we found that the Arg16Arg group (n=6) had an attenuated response to β-agonist when compared to the Gly-containing group (n=11) (FVC=0±0.9 vs. 6±3: FEV1=3±1 vs. 7±4: MMF=12±3 vs. 12±5 % change, for Arg16Arg and Gly-containing groups, respectively, p<0.05 for FVC, p=0.06 for FEV1). Conclusions: These results demonstrate a differential response to β-agonists according to genetic variation of the ADRB2 at amino acid 16. Due to the differences in FVC and FEV1 but not in MMF, these data suggest that the genetic difference in airway function is primarily in bronchodilation of the larger airways.

Class of 2010 Abstract / OBJECTIVES: Cystic fibrosis (CF) is a disease that adversely affects the lung resulting in a reduction of lung diffusion. Stimulation of the β2 adrenergic receptors results in mucocilliary clearance, and therefore, lung diffusion. We sought to determine the influence of an inhaled β-­‐agonist on the diffusing capacity of the lungs for carbon monoxide (DLCO), alveolar-­‐capillary membrane conductance (DM), pulmonary capillary blood volume (Vc), and peripheral oxygen saturation (SaO2) in subjects with CF and compare the data to matched healthy subjects. METHODS: To determine this we recruited 20 healthy subjects and 18 subjects with CF (age=23±7 vs. 24±4years, ht=168±8 vs. 174±12cm. wt=64±16 vs. 70±13kg, BMI= 23±4 vs. 23±3kg/m2, FEV1= 72±27 vs. 92±12%pred., VO2peak = 45±25 vs. 99±24%pred., P<0.05 for FEV1 and VO2peak, mean±SD) for the study and measured DLCO, DM, Vc and SaO2 before and 30, 60, and 90 minutes following the administration of inhaled albuterol. RESULTS: Within the healthy subjects, there were no differences in DLCO, DM, Vc, DM/Vc at baseline or in response to albuterol according to genetic variation of the ADRB2 at amino acid 27. Within the CF group, the Glu27Glu/Gln27Glu group had higher DM/Vc when compared to the Gln27Gln group at baseline. Both genotype groups had a significant decline in Vc and a significant improvement in DM/Vc and SaO2 in response to albuterol, but not in DLCO or DM. CONCLUSIONS: These results suggest that there are differences in lung diffusion and peripheral SaO2 according to genetic variants of the ADRB2 at position 27 and could play a potential role in treatment options.