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The role of CFTR in male reproduction and the underlying mechanisms. / CUHK electronic theses & dissertations collectionJanuary 2008 (has links)
As CFTR plays an important role in HCO3- transport, and HCO3- sensitive soluble adenylyl cyclase (sAC) has been shown to be largely responsible for the cAMP production in spermatogenetic cells, we hypothesized that CFTR-mediated HCO3- transport was important to spermatogenesis via sAC pathway in spermatogenetic and Sertoli cells. Using intracellular pH measurement, we demonstrated that CFTR is involved in HCO3- transport in Sertoli cells. RT-PCR results showed that increased HCO3- concentrations in the culture medium resulted in upregulation of CFTR expression. The results also showed that the intracellular cAMP level in Sertoli cells increased as the extracellular HCO3- concentration increased. HCO3- also caused phosphorylation of the cAMP response element binding (pCREB) proteins transcription factor on serine 133, a modification known to be required by Sertoli cells to support spermatogenesis. This phosphorylation could be inhibited by CFTR inhibitor, further lending support to the notion that CFTR is important for HCO3- transport in Sertoli cells, leading to HCO3- dependent events that are important for spermatogenesis. / CFTR is known to be widely expressed in epithelial cells of male reproductive tracts, but its expression in spermatogenic cells is less well known. We first confirmed the expression of CFTR in spermatogenic cells and mature sperm in rodents. Our study thus focused on the important role of CFTR in the processes related to male fertility including spermatogenesis and sperm capacitation. / Cystic fibrosis transmembrane conductance regulator (CFTR) is an anion channel, mutations of which cause cystic fibrosis, a disease characterized by defective Cl- and HCO3- transport. While over 95% of CF male patients are infertile because of congenital bilateral absence of the vas deferens (CBAVD), the question whether CFTR mutations are involved in other forms of male infertility is under intense debates. / In conclusion, our study has demonstrated the role of CFTR in male reproductive system. We have further elucidated its possible physiological role and the underlying molecular mechanisms. These studies may pave the way for the development of method strategies for diagnosis and treatment of CFTR related infertility in male. / Our study also detected CFTR in both human and mouse sperm. CFTR inhibitor or antibody significantly reduced sperm capacitation, and the associated HCO 3--dependent events including increases in intracellular pH, cAMP production and membrane hyperpolarization. The fertilizing capacity of the sperm obtained from heterozygous CFTR mutant mice is also significantly lower as compared to that of the wild type. These results suggest that CFTR in sperm may be involved in the transport of HCO3- important for sperm capacitation and that CFTR mutations with impaired CFTR function may lead to reduced sperm fertilizing capacity and male infertility other than CBAVD. / We further demonstrated the physiological role of CFTR in spermatogenesis using CFTR knockout mice as an in vivo model. Although TUNNEL staining showed normal percentage of apoptotic cells in seminiferous tubules, Cftr -/- mice had spermatogenetic defects in histology section and fewer number of mature sperm compared with wild type (WT) mice. Consistent with the proposed role of CFTR in spermatogenesis, RT-PCR and Western blot results showed reduced expression of spennatids specific gene, Protamine 1, Protamine 2, and CREM, which have been known to be involved in the process of spermatogenesis, in Cftr-/- mice. / Xu, Wenming. / "January 2008." / Source: Dissertation Abstracts International, Volume: 69-08, Section: B, page: 4506. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (p. 121-138). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract in English and Chinese. / School code: 1307.
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Experiences and Outcomes of Healthcare Transition in Cystic FibrosisSouth, Katherine January 2023 (has links)
The aim of this dissertation is to explore experiences and describe outcomes of healthcare transition in cystic fibrosis (CF).
Chapter one introduces the central concepts of this dissertation, describes current gaps in the literature on healthcare transition in cystic fibrosis and introduces the Expanded Socioecological Model for Adolescent and Young Adult Readiness for Transition (Expanded SMART), which guides the three studies of this dissertation.
Chapter two is a qualitative meta-synthesis of 63 studies describing adolescent, young adult, and parent experiences of healthcare transition across a variety of chronic conditions. Chapter three is a qualitative study exploring perceptions of CF management responsibility among a sample of 15 adolescent with CF and parent dyads. Chapter four uses national Cystic Fibrosis Foundation Patient Registry data to examine healthcare transition outcomes associated with participation in the transition preparation program CF R.I.S.E. Chapter five synthesizes the three studies of this dissertation and provides recommendations for practice, policy, and research.
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The role of cystic fibrosis transmembrane conductance regulator (CFTR) in ovarian functions. / CUHK electronic theses & dissertations collectionJanuary 2012 (has links)
卵巢是女性生殖系統中一個重要的器官,負責為受精提供卵子,以及合成生殖過程中所必需,同時也在其他生理過程中起重要作用的各種激素。大約有30%的不育源於卵巢的問題,包括無排卵,無月經,月經週期不規律和激素水平異常等。雄激素:雌激素比例過高,卵泡發育異常,無排卵等卵巢功能障礙常見於各種疾病中,例如多囊性卵巢綜合征(PCOS)--一種影響5~10%育齡婦女的內分泌疾病,以及囊性纖維化( CF)--一種由囊性纖維化跨膜電導調節器(CFTR) 基因突變引起的遺傳疾病。然而引起這些卵巢功能障礙的確切機制並不清楚。 / 雌激素是在卵泡雌激素(FSH) 的調節下,在卵巢顆粒細胞中通過芳香化臨的住激素轉化而生成的。在論文第一部分的研究中,我們旨在證明CFTR 在卵巢顆粒細胞中的表達,以及它參與雌激素生成的過程。實驗結果證實了CFTR 在小鼠和人顆粒細胞中的表達,同時表明CFTR 通過一種碳酸氫根離子(HC0₃⁻) 敏感的可溶性腺苦酸環化梅(sAC) ,放大FSH 所刺激的雌激素生成過程。實驗結果顯示,在原代小鼠顆粒細胞中, HC0₃⁻能夠增強FSH 所引起的CREB 磷酸化,芳香化晦表達,以及雌激素的生成,而在抑制CFTR 的情況下,或在CFTR 敲除/DeltaF508 突變小鼠的顆粒細胞中, HCO3-的放大作用顯著降低。CFTR 和芳香化醋的表達水準在人顆粒細胞中具有正相關性,進一步支持CFTR 對雌激素生成的調節作用。在PCOS 患者的顆粒細胞和大鼠PCOS 模型的卵巢中, CFTR 和芳香化醋的表達水準顯著下調。這些結果提示, CFTR 對雌激素生成調節這一機制的缺陷可能參與了CF 和PCOS 中卵巢功能障礙的發病機理。 / 卵泡發育很大程度上依賴於顆粒細胞的增殖'生存和凋亡,這些過程在PCOS 中都會出現異常。論文的第二部分冒在研究顆粒細胞的CFTR 在PCOS 的卵泡發育異常中的作用。實驗結果表明, CFTR 在PCOS 大鼠的囊,性卵泡的顆粒細胞中表達降低,同時伴隨著PCNA 和Bcl-2 的下調,而Bax 和cleaved caspase-3則沒有變化,提示顆粒細胞的增殖和生存/抗凋亡能力降低。敲減或抑制顆粒細胞中的CFTR 導致細胞存活降低, PCNA 和Bcl-2 表達下調,以及細胞凋亡增加,提示CFTR 對顆粒細胞增殖和生存的調節作用。CFTR 通過HC0₃⁻/ sAC/PKA 信號通路,調節基礎及FSH 刺激引起的ERK I!2 磷酸化,及其下游的CyclinD2 和PCNA表達,從而促進顆樹圍胞的增殖。顆粒細胞CFTR 的下調可能通過抑制細胞增殖和降低細胞生存能力,參與了PCOS 中的囊性卵泡的形成過程。 / 綜上所述,本論文證明了CFTR 在卵巢顆粒細胞上的表達,並且參與調節顆粒細胞雌激素生成和細胞的增殖和生存。CFTR 的缺陷或表達下調可能是導致CF和PCOS 的卵巢功能障礙的發病機理。 / The ovary is the female reproductive organ, which produces female gametes, oocytes for fertilization and sex hormones essential to reproduction and important to a wide range of physiological and pathological events as well. About 30% of infertility cases arise from ovarian problems, including anovulation, amenorrhea, irregular menstrual cycle and abnormal hormone levels. Ovarian disorders, such as high androgen to estrogen ratio, abnormal folliculogenesis and anovulation, are often seen in diseases, including polycystic ovarian syndrome (PCOS) and cystic fibrosis (CF). The former is an endocrine disorder affecting 5~10% women of reproductive age, and the latter is a common genetic disease caused by mutations of the cystic fibrosis transmembrane conductance regulator (CFTR). However, the exact mechanisms underlying the ovarian disorders seen in these diseases are not well understood. / Estrogen biosynthesis is profoundly influenced by follicle-stimulating hormone (FSH) that regulates the conversion of androgen to estrogen in ovarian granulosa cells by the rate-limiting enzyme aromatase. The first part of the study aims to investigate the expression of CFTR in granulosa cells and its involvement in regulating estrogen production. The results demonstrate the expression of CFTR in both mouse and human granulosa cells, and provide evidence demonstrating a previously unsuspected role of CFTR in amplification of FSH-stimulated ovarian estrogen biosynthesis and the involvement of a HC0₃⁻ sensor, the soluble adenylyl cyclase (sAC) in this synthesis. FSH-stimulated CREB phosphorylation, aromatae expression, as well as estradiol production are enhanced by HC0₃⁻ and sAC, which could be significantly reduced by CFTR inhibition or in ovaries or granulosa cells of cftr knockout/deltaF508 mutant mice. The fact that CFTR expression is found positively correlated with aromatase expression in human granulosa cells supports its role in regulating estrogen production in humans. Reduced CFTR and aromatase expression is also found in polycystic ovarian syndrome (PCOS) rodent models and human patients. These findings suggest that defective CFTR-dependent regulation of estrogen production may underline the ovarian disorders seen in CF and PCOS. / Folliculogenesis largely depends on the proliferation, survival and apoptosis of granulosa cells in the follicles and alteration in which has been found in PCOS. The second part of the study aims to investigate the possible involvement of granulosa cell CFTR in the impaired folliculogenesis in PCOS. The results show that downregulation of CFTR is found in the cystic follicles, which is accompanied by reduced expression of PCNA and Bcl-2, but not Bax and cleaved caspase-3, in the ovaries of PCOS rat models, indicating reduced cell proliferation and survival/anti-apoptotic ability. Knockdown or inhibition of CFTR in granulosa cell culture results in reduced cell viability, downregulation of PCNA and Bcl-2 and increase of apoptosis, supporting a role of CFTR in regulating granulosa cell proliferation and survival. CFTR exerts its effect on granuloa cell proliferation by modulating basal and FSH-stimulated ERKl/2 phosphorylation and the expression of its downstream target CyclinD2 and PCNA through the HC0₃⁻/sAC/PKA pathway. These findings suggest that downregulation of CFTR may play a role in the formation of cystic follicles by inhibiting granulosa cell proliferation and reducing cell survival ability, therefore providing a possible mechanism for the abnormal folliculogenesis in PCOS. / In conclusion, the present study has demonstrated the expression of CFTR in the ovarian granulosa cell and its role in regulation of granulosa cell proliferation, survival and estrogen production. Defect of CFTR in CF and downregulation of CFTR in PCOS may contribute to the abnonnal honnone profile and impaired folliculogenesis in both disease conditions. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Chen, Hui. / "October 2011." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 124-137). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese. / ABSTRACT --- p.i / 摘要 --- p.iv / ACKNOWLEDGEMENT --- p.vi / LIST OF PUBLICATIONS --- p.viii / ABBREVIATIONS --- p.xiii / LIST OF FIGURES AND TABLES --- p.xvi / Chapter 1 --- CHAPTER I: Introduction --- p.1 / Chapter 1.1 --- The ovary --- p.1 / Chapter 1.1.1 --- Structure and function of the ovary --- p.1 / Chapter 1.1.2 --- Follicle development --- p.5 / Chapter 1.1.3 --- Ovulation and luteinization --- p.7 / Chapter 1.1.4 --- Ovarian hormone biosynthesis --- p.10 / Chapter 1.2 --- Diseases with ovarian dysfunction --- p.14 / Chapter 1.2.1 --- Polycystic ovarian syndrome (PCOS) --- p.14 / Chapter 1.2.1.1 --- Introduction to PCOS --- p.14 / Chapter 1.2.1.2 --- Diagnostic criteria --- p.14 / Chapter 1.2.1.3 --- Abnormal hormone profile in PCOS --- p.16 / Chapter 1.2.1.4 --- Abnormal folliculogenesis in PCOS --- p.18 / Chapter 1.2.1.5 --- Etiology --- p.22 / Chapter 1.2.2 --- Cystic Fibrosis (CF) --- p.24 / Chapter 1.2.2.1 --- Introduction to CF --- p.24 / Chapter 1.2.2.2 --- Cause and pathogenesis of CF --- p.25 / Chapter 1.2.2.3 --- Ovarian disorder in CF --- p.27 / Chapter 1.3 --- CFTR in reproduction --- p.29 / Chapter 1.3.1 --- Introduction to CFTR --- p.29 / Chapter 1.3.2 --- Channel function --- p.30 / Chapter 1.3.3 --- Protein regulator function --- p.32 / Chapter 1.3.4 --- Regulation of CFTR expression --- p.34 / Chapter 1.3.5 --- Role of CFTR in reproduction --- p.35 / Chapter 1.3.6 --- CFTR in the ovary --- p.39 / Chapter 1.4 --- General hypothesis and aims --- p.39 / Chapter 1.4.1 --- General hypothesis --- p.39 / Chapter 1.4.2 --- Aims of the study --- p.40 / Chapter 2 --- CHAPTER II: General Methods --- p.42 / Chapter 2.1 --- Meterials --- p.42 / Chapter 2.1.1 --- Animals --- p.42 / Chapter 2.1.2 --- Chemicals and reagents --- p.42 / Chapter 2.1.3 --- Antibodies --- p.44 / Chapter 2.1.4 --- Primers --- p.45 / Chapter 2.2 --- Methods --- p.45 / Chapter 2.2.1 --- Determination of estrous cycle --- p.45 / Chapter 2.2.2 --- Granulosa cell culture --- p.46 / Chapter 2.2.3 --- PCGS rat model --- p.47 / Chapter 2.2.4 --- Collection of human granulosa cells --- p.47 / Chapter 2.2.5 --- Reverse transcription-polymerase chain reaction (RT-PCR) --- p.48 / Chapter 2.2.6 --- Western blot --- p.50 / Chapter 2.2.7 --- Histological studies --- p.53 / Chapter 2.2.8 --- siRNA transfection --- p.55 / Chapter 2.2.9 --- Intracellular pH measurement --- p.56 / Chapter 2.2.10 --- Whole-cell patch clamp recording --- p.57 / Chapter 2.2.11 --- Statistics --- p.57 / Chapter 3 --- CHAPTER III: Result I - The Role of CFTR in FSH-stimulated Estrogen Production: Implication in Cystic Fibrosis and PCGS --- p.59 / Chapter 3.1 --- Summary --- p.59 / Chapter 3.2 --- Introduction --- p.60 / Chapter 3.3 --- Methods --- p.63 / Chapter 3.3.1 --- Intracellular cAMP assay --- p.63 / Chapter 3.3.2 --- Nuclei isolation and nuclear cAMP measurement --- p.63 / Chapter 3.3.3 --- CREB phosphorylation assay --- p.64 / Chapter 3.3.4 --- Estradiol enzyme immunoassay --- p.64 / Chapter 3.4 --- Results --- p.64 / Chapter 3.4.1 --- Functional expression of CFTR in granulosa cells --- p.64 / Chapter 3.4.2 --- Expression and localization of sAC in granulosa cells and its involvement in BC03f CFTR-dependent cAMP production --- p.66 / Chapter 3.4.3 --- Effect of CFTR and HC0₃⁻ on basal and FSB-stimulated CREB phosphorylation --- p.67 / Chapter 3.4.4 --- Effect of CFTR and HC0₃⁻ on basal and FSB-stimulated aromatase expression and estradiol production --- p.68 / Chapter 3.4.5 --- Impaired CREB phosphorylation aromatase expression and estradiol production by granulosa cells from CFTR-deficient mice --- p.70 / Chapter 3.4.6 --- Reduced CFTR and aromatase expression in human PCOS granulosa cells and rat PCOS ovaries --- p.71 / Chapter 3.5 --- Discussion --- p.87 / Chapter 4 --- CHAPTER IV: Result II - The Role of CFTR in Granulosa Cell Proliferation and survival in PCOS --- p.91 / Chapter 4.1 --- Summary --- p.91 / Chapter 4.2 --- Introduction --- p.92 / Chapter 4.3 --- Methods --- p.95 / Chapter 4.3.1 --- Cell viability assay (MTT and MTS assay) --- p.95 / Chapter 4.3.2 --- ERKI/2 phosphorylation assay --- p.95 / Chapter 4.4 --- Results --- p.96 / Chapter 4.4.1 --- Reduced CFTR expression in PCOS rat models --- p.96 / Chapter 4.4.2 --- Downregulation of genes related to proliferation and survival in PCOS --- p.96 / Chapter 4.4.3 --- CFTR affect viability of granulosa cells --- p.97 / Chapter 4.4.4 --- CFTR regulate cell cycle protein and promote proliferation via HC0₃⁻/sAC/PKA and ERK pathway --- p.98 / Chapter 4.4.5 --- CFTR regulates apoptosis-related protein expression --- p.100 / Chapter 4.5 --- Discussion --- p.114 / Chapter 5 --- CHAPTER V: General Discussion --- p.119 / Chapter 5.1 --- Role of CFTR in ovarian function --- p.119 / Chapter 5.2 --- Role of CFTR/HC0₃⁻/sAC in modulating FSH signaling in the ovary --- p.120 / Chapter 5.3 --- CFTR/HC0₃⁻/sAC as a general modulator in receptor-mediated signaling cascades --- p.122 / Chapter 5.4 --- Concluding remarks --- p.123 / REFERENCES --- p.124 / APPENDICES --- p.138
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Functional role of cystic fibrosis transmembrane conductance regulator (CFTR) in the male reproductive system. / CUHK electronic theses & dissertations collectionJanuary 2004 (has links)
Cheung King Ho. / "August 2004." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (p. 140-158). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.
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Qualitative study of cystic fibrosis (CF) patients' expectations of gene therapyJannetta, Evelyn Elena January 2009 (has links)
Introduction: Gene therapy is currently being developed for people with cystic fibrosis (CF), a life-threatening condition for which there is no cure. The UK CF Gene Therapy Consortium are preparing for a multi-dose gene therapy trial of sufficient duration that clinical benefit may be seen. Aims: The current study aimed to explore the expectations and beliefs of cystic fibrosis (CF) patients involved in the preparatory phase of the gene therapy trial (the Run-in study), from which participants will be selected for the multi-dose actual gene therapy trial. Method: Twelve participants (six with mild and six with moderate CF) were interviewed using a semi-structured interview. Interviews were recorded, transcribed verbatim and then analysed using a Constructivist Grounded Theory approach. Results: Since entering the Run-in study, half of the patients had increased their expectations of gene therapy being an effective future treatment. Most of the participants hoped to derive clinical benefit from the trial itself though half were unsure of what to expect. Whilst half of the participants expressed the hope of a future cure for CF, the remainder saw gene therapy only in terms of an improved treatment. Participants used several strategies to manage their expectations including not thinking too far ahead and trusting the research team. Discussion: The findings indicate that participants in the Run-in trial are generally eager to be involved in the gene therapy trial and have developed a strong sense of trust in the research team conducting the trials. The levels of optimism expressed for personal benefit from trial were higher than those from earlier studies. Some of the positive expectations were unlikely to be met by the gene therapy trial and participants risk disappointment. However other patients participated with apparently realistic expectations and it seems likely that some patients would have participated even without prospect for personal benefit. Possible areas of psychological support are discussed e.g. a standard clinical interview for all those not accepted for the gene therapy trial; screening for anxiety pre-, during and post-participation.
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Parental Grief when a child is diagnoised with a life-threatening chronic-illness: The impact of gender, perceptions and coping strategies.Betman, Johannah Erna Marie January 2006 (has links)
The grief experienced by mothers and fathers when their child is diagnosed with a life threatening chronic-illness was investigated in order to validate the presence of grief in these parents and look at the factors that influence it. More specifically, I was interested in whether the grief experience differed for mothers and fathers and the impact that perceptions and coping have on both these gender differences in grief and on grief in general. The particular population investigated in this study were parents of children with Cystic Fibrosis. Participants were recruited through questionnaires randomly sent out by the National Cystic Fibrosis Association. In all, 37 mothers and 15 fathers took part. Results not only confirmed presence of grief in these parents but also indicated that this grief differs for mothers and fathers, with mothers reporting significantly higher levels of physical distress. In line with the literature no gender differences were found in regards to perception of impact parents felt their child's chronic-illness had had on their lives. Contrary to what was expected, however, no differences were found amongst the coping strategies used by mothers and fathers. In regards to the question of which factors have the greatest impact on the grief experienced by mothers and fathers combined, the coping strategy of self-blame was found to be the most important, followed closely by negative perceptions. The significance of these findings and their implications for parents and the people who work with them was discussed.
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Molecular approaches to fungal infections in immunocompromised patientsWilliamson, Emma Charlotte Mary January 2001 (has links)
No description available.
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The effect of glycosaminoglycans on cytokine-mediated inflammatory cell recruitmentRamdin, Lara S. P. January 1998 (has links)
No description available.
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The electrical manipulation of bio-formulations for delivery to the lungDavies, Lee January 2001 (has links)
No description available.
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Regulation of a COX-2/PGE₂ by cystic fibrosis transmembrane conductance regulator: implications in inflammation and infertility. / CUHK electronic theses & dissertations collectionJanuary 2012 (has links)
環氧合酶-2(COX-2)是在花生四烯酸(AA)轉化為前列腺素H₂(PGH₂)的過程中最重要的限速酶,PGH2再進一步被合成為各種前列腺素,包括前列腺素E₂(PGE₂), 因此,COX-2在前列腺素的合成中起著舉足輕重的作用。COX-2在受到例如感染和炎症等刺激的情況下被誘導,迅速大量地產生。越來越多的證據證明瞭COX-2在許多細胞反應和病理生理過程中起重要作用, 其中, 對COX-2在炎症中的作用研究最深入。 / 囊性纖維化病(CF)是一種由於編碼囊性纖維化跨膜轉導調節器(CFTR)基因的突變所引起的常染色體隱性遺傳疾病。CFTR是在上皮細胞中廣泛表達的環磷酸腺苷(cAMP)依賴的陰離子通道。愈來愈多的證據顯示, CF的呼吸道上皮處於過量炎症因子和前列腺素的微環境中, 最終導致了在CF肺部病變中觀察到的超炎症反應. 但其中的機制仍未闡明. 本研究觀察到, 相對於野生型人類支氣管上皮細胞系(16HBE14o-), CF的人類支氣管上皮細胞系(CFBE41o-)中NFκB的活化, COX-2的表達和PGE₂的產量增加. 此外, CFTR基因敲除小鼠顯示出升高的NFκB活性和COX-2表達水準, 提示CFTR基因的缺失介導了超炎症反應的信號. 我們還驗證了一條PKA和CREB參與介導的PGE₂產生的正回饋通路. 更重要的是, 在CFBE41o-細胞中過表達CFTR顯著地抑制了COX-2的表達. 用LPS或者PGE₂處理16HBE14o-細胞導致了野生型CFTR表達的顯著升高. 這些實驗結果提示了CFTR可能參與對COX-2/PGE₂的負調節. 因此, CFTR負調節PGE₂介導的炎症反應. 這個調節機制的缺陷可能導致在CF炎症反應的組織中觀察到的過量的NFκB活化和過量PGE₂產生. / 我們證實了睾丸中也存在這條CFTR負調節COX-2/PGE₂的通路. 由於隱睾處於比陰囊溫度高的腹腔中, 在隱睾中, 我們觀察到了高溫導致的CFTR下調,伴隨著COX-2的上調以及緊密連接蛋白(ZO-1, occludin)的下調. 這種CFTR和COX-2的負相關在小鼠睾丸高熱動物模型以及CFTR基因敲除小鼠模型中也被證實. 為了模擬隱睾的病理狀況, 我們提高原代睾丸支援細胞的培養溫度至37°C. 與在32°C培養條件下的對照細胞相比, 37C培養的支持細胞中CFTR表達顯著下調, 而COX-2表達顯著上調. 用CFTR的抑制劑CFTRinh-172處理支持細胞48小時後, COX-2的表達也上升了. 抑制或者敲除支持細胞中的CFTR都引起了ZO-1和occludin表達水準的下降, 從而損傷了支持細胞間的緊密連接. NFκB或者PGE₂的抑制劑都能逆轉ZO-1和occludin表達水準的下降. PGE₂同樣導致了支援細胞間緊密連接的損傷. 以上結果提示CFTR對緊密連接的調節作用是通過NFκB/COX-2/PGE₂通路實現的. 本研究闡明了在支持細胞中, CFTR通過負調節NFκB/COX-2/PGE₂通路調節緊密連接, 從而參與了隱睾導致的生精障礙的病理過程. / 總之, 本研究論證了CFTR/COX-2/PGE₂通路在CF呼吸道的超炎症反應以及隱睾導致的生精障礙兩個病理過程中的作用, 說明了CFTR在呼吸系統和男性生殖系統中維持細胞因子穩態的重要作用. CF肺中CFTR的缺失或者隱睾病中CFTR表達水準的下降可能導致了呼吸道中過剩炎症反應和生精障礙. / Cyclooxygenase-2 (COX-2) is a pivotal rate-limiting enzyme responsible for the production of prostaglandins by converting arachidonic acid (AA) to prostaglandin H₂ (PGH₂), which is further metabolized to various prostaglandins, including PGE₂. COX-2 is inducible and increases dramatically upon stimulation, such as infection and inflammation. Accumulating evidences have demonstrated the important role of COX-2 in many cellular responses and pathophysiological processes, especially inflammation. / Cystic Fibrosis (CF) is an autosomal recessive disorder caused by mutations of the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR), a cAMP-dependent anion channel expressed in many epithelia. Accumulating evidence suggests that CF airway epithelia are overwhelmed by excessive inflammatory cytokines and prostaglandins (PGs), which eventually lead to the over-inflammatory condition observed in CF lung disease. However, the exact underlying mechanism remains elusive. In this study, we observed increased COX-2 expression and over-production of prostaglandin E₂ (PGE₂) in human CF bronchial epithelial cell line (CFBE41o-) with elevated NFκB activity compared to a wild-type bronchial epithelial cell line (16HBE14o-). Moreover, we demonstrated that CFTR knockout mice had inherently higher levels of COX-2 and NFκB activity, supporting the notion that lack of CFTR results in hyper-inflammatory signaling. In addition, we identified a positive feedback loop for production of PGE₂ involving PKA and transcription factor, CREB. More importantly, overexpression of wild-type CFTR significantly suppressed COX-2 expression in CFBE41o- cells, and wild-type CFTR protein expression was significantly increased when 16HBE14o- cells were challenged with LPS as well as PGE₂, indicating possible involvement of CFTR in the negative regulation of COX-2/PGE₂. These results suggest that CFTR is a negative regulator of PGE₂-mediated inflammatory response, defect of which may result in excessive activation of NFκB, leading to over production of PGE2 as seen in inflammatory CF tissues. / This negative regulation of COX-2/PGE₂ pathway by CFTR was also identified in the testis in the present study. Downregulation of CFTR accompanied by upregulation of COX-2/PGE₂ and downregulation of tight junction proteins, including ZO-1 and occludin, were observed in a cryptorchidism mouse model with elevated testis in the abdomen, at which the temperature is several degrees higher than that in the scrotum. The inverse correlation of CFTR and COX-2 was further confirmed in a mouse testis hyperthermia model and in CF mice. Culturing primary Sertoli cells at a temperature of 37°C, which mimics the pathological condition of cryptorchidism, led to a significant decrease in CFTR and increase in COX-2 expression compared to the physiological condition of 32°C. Increase of COX-2 expression was also detected 48 hours after administrating CFTRinh-172 to the cells. Inhibition or knockdown of CFTR led to decreased ZO-1 and occludin expression and impaired tight junction in Sertoli cells, which could be mimicked by PGE₂, but reversed by NFκB and COX-2 inhibitors, suggesting that regulation of tight junction by CFTR is mediated by NFκB /COX-2/PGE₂ pathway. This study illustrates that CFTR may be involved in regulating testicular tight junctions through its negative regulation of NFκB/COX-2/PGE₂ pathway in Sertoli cells, defect of which may result in spermatogenesis defect in cryptorchidism. / Taken together, the present study has demonstrated the role of CFTR/ NFκB /COX-2/PGE₂ pathway in two pathological processes, exaggerated inflammation in CF airway and defective spermatogenesis in cryptorchidism, indicating that CFTR is critical for maintaining cytokine homeostasis in respiratory system and male reproductive system. Defect of CFTR in CF lung and downregulation of CFTR in cryptorchidism may contribute to the excessive lung inflammation and impaired spermatogenesis respectively. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Chen, Jing. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 109-121). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese. / ABSTRACT --- p.i / 摘要 --- p.iv / ACKNOWLEDGEMENT --- p.vi / LIST OF PUBLICATIONS --- p.vii / ABBREVIATIONS --- p.xii / LIST OF FIGURES AND TABLES --- p.xvi / Chapter 1 --- Chpter 1: Overview --- p.1 / Chapter 1.1 --- CFTR and Cystic Fibrosis --- p.1 / Chapter 1.1.1 --- Cystic Fibrosis --- p.1 / Chapter 1.1.2 --- Structure of CFTR --- p.2 / Chapter 1.1.3 --- Mutations of CFTR --- p.2 / Chapter 1.1.4 --- Channel and signal transduction function of CFTR --- p.3 / Chapter 1.1.5 --- Interaction of CFTR with other proteins --- p.4 / Chapter 1.1.6 --- Regulation of CFTR --- p.5 / Chapter 1.2 --- COX-2 and PGE₂ --- p.6 / Chapter 1.2.1 --- Biosynthesis of PGE₂ --- p.6 / Chapter 1.2.2 --- Pathophysiologic roles of COX-2 and PGE₂ --- p.7 / Chapter 1.2.3 --- Role of COX-2/PGE₂ in inflammation --- p.7 / Chapter 1.2.4 --- Regulation of COX-2 --- p.8 / Chapter 1.2.4.1 --- Regulation of COX-2 by NF-κB --- p.9 / Chapter 1.2.4.2 --- Regulation of COX-2 by CREB --- p.10 / Chapter 1.3 --- Link between CFTR and NF-κB --- p.11 / Chapter 1.4 --- General hypothesis and aims of study --- p.12 / Chapter 2 --- Chapter 2: CFTR negatively regulates COX-2/PGE₂ positive loop in feedback loop in inflammation --- p.13 / Chapter 2.1 --- Introduction --- p.13 / Chapter 2.1.1 --- Airway inflammation in Cystic Fibrosis --- p.13 / Chapter 2.1.2 --- Current theories on the causes of pulmonary inflammation in CF --- p.13 / Chapter 2.1.2.1 --- Theory one --- p.14 / Chapter 2.1.2.2 --- Theory two --- p.16 / Chapter 2.1.3 --- Role of airway epithelia in CF airway inflammation --- p.16 / Chapter 2.1.4 --- Link between CFTR and NF-κB in pulmonary inflammation --- p.17 / Chapter 2.1.5 --- Link between CFTR and COX-2/PGE₂ in pulmonary inflammation --- p.18 / Chapter 2.1.6 --- Hypothesis and aims of study --- p.18 / Chapter 2.2 --- Materials and methods --- p.20 / Chapter 2.2.1 --- Cell culture materials --- p.20 / Chapter 2.2.2 --- Animals --- p.20 / Chapter 2.2.3 --- Chemicals, drugs and assay kits --- p.20 / Chapter 2.2.4 --- Antibodies --- p.22 / Chapter 2.2.5 --- Cell culture. --- p.22 / Chapter 2.2.6 --- Animal models and procedures --- p.23 / Chapter 2.2.7 --- Manipulation of RNA and QRT-PCR --- p.23 / Chapter 2.2.8 --- Manipulation of protein and Western blot --- p.25 / Chapter 2.2.9 --- Histological and morphological --- p.27 / Chapter 2.2.9.1 --- Tissue section. --- p.28 / Chapter 2.2.9.2 --- Hematoxylin and eosin staining --- p.28 / Chapter 2.2.9.3 --- Immunohistochemistry --- p.28 / Chapter 2.2.10 --- PGE₂ EIA --- p.29 / Chapter 2.2.11 --- Statistical analysis --- p.30 / Chapter 2.3 --- Results --- p.30 / Chapter 2.3.1 --- Increased expression of NF-κB and COX-2 in the lung of CF mice --- p.31 / Chapter 2.3.2 --- Defect of CFTR leads to increased COX-2 expression in CF cell line --- p.31 / Chapter 2.3.3 --- Increased expression of COX-2 in CF cells is attributed to NF-κB activation --- p.33 / Chapter 2.3.4 --- A positive feedback loop from PGE₂ to COX-2 is mediated by PGE₂/cAMP/PKA/p-CREB pathway --- p.34 / Chapter 2.3.5 --- PGE₂ increase the expression of CFTR protein in 16HBE14o- but not in CFBE41o- cells --- p.35 / Chapter 2.4 --- Discussion --- p.47 / Chapter 2.5 --- Conclusion --- p.51 / Chapter 3 --- Chapter 3: Role of CFTR/COX-2/PGE₂ Pathway in the Regulation of Junctional Complex Proteins in Sertoli Cells and its Implication in Spermatogenesis Defect in Cryptorchidism --- p.53 / Chapter 3.1 --- Introduction --- p.53 / Chapter 3.1.1 --- Spermatogenesis.p53 / Chapter 3.1.1.1 --- Structure of the seminiferous tubules --- p.53 / Chapter 3.1.1.2 --- Role of Sertoli cells in spermatogenesis --- p.55 / Chapter 3.1.1.3 --- Role of junctional complexes in spermatogenesis --- p.55 / Chapter 3.1.2 --- Junctional complexes in the testis --- p.59 / Chapter 3.1.2.1 --- Tight Junction --- p.59 / Chapter 3.1.2.2 --- Anchoring Junction. --- p.60 / Chapter 3.1.2.3 --- Cross talk between TJs and AJs --- p.60 / Chapter 3.1.3 --- Cryptorchidism --- p.61 / Chapter 3.1.3.1 --- Causes and consequences of Cryptorchidism --- p.61 / Chapter 3.1.3.2 --- Elevated temperature caused by cryptorchidism greatly contributes to defective spermatogenesis --- p.62 / Chapter 3.1.3.3 --- Changes of Sertoli cells in cryptorchidim contributing to defective spermatogenesis. --- p.62 / Chapter 3.1.3.4 --- Disruption of junctional complexes in heat shock and cryptorchidism. --- p.65 / Chapter 3.1.4 --- CFTR and spermatogenesis --- p.66 / Chapter 3.1.4.1 --- Expression of CFTR in Sertoli cells in testis --- p.66 / Chapter 3.1.4.2 --- Temperature sensitive processing of CFTR protein --- p.66 / Chapter 3.1.4.3 --- CFTR and junctional complex --- p.67 / Chapter 3.1.4.4 --- CFTR and male reproduction --- p.68 / Chapter 3.1.4.5 --- Role of CFTR in spermatogenesis --- p.68 / Chapter 3.1.5 --- Prostaglandins and male fertility --- p.69 / Chapter 3.1.5.1 --- Expression of COX-2 in testis. --- p.69 / Chapter 3.1.5.2 --- Role of prostaglandins in spermatogenesis --- p.70 / Chapter 3.1.5.3 --- Regulation of junctional complexes by PGE₂ --- p.70 / Chapter 3.1.5.4 --- Prostaglandins in cryptorchidism --- p.72 / Chapter 3.1.6 --- Hypothesis and aims of study --- p.73 / Chapter 3.2 --- Materials and Methods --- p.74 / Chapter 3.2.1 --- Cell culture materials --- p.74 / Chapter 3.2.2 --- Drugs and Reagents --- p.74 / Chapter 3.2.3 --- Antibodies --- p.74 / Chapter 3.2.4 --- Animals --- p.75 / Chapter 3.2.4.1 --- Mice artificial cryptorchidism model --- p.75 / Chapter 3.2.4.2 --- Mice testes hyperthermia model --- p.75 / Chapter 3.2.5 --- Sertoli cell primary culture --- p.76 / Chapter 3.2.6 --- siRNA against CFTR and transfection --- p.76 / Chapter 3.2.7 --- Examination of assembly and destruction of assembly of inter-Sertoli TJs --- p.77 / Chapter 3.2.8 --- Manipulation of RNA and Real-Time Quantitative RT-PCR (QRT-PCR) --- p.77 / Chapter 3.2.9 --- Manipulation of protein and western blot --- p.77 / Chapter 3.2.10 --- Histological and morphological studies --- p.78 / Chapter 3.2.10.1 --- Immunofluorescence of ZO-1 Staining in Sertoli cells --- p.78 / Chapter 3.2.10.2 --- Immunofluorescent staining of ZO-1, Occludin and β-Catenin in testes --- p.78 / Chapter 3.2.11 --- PGE₂ EIA --- p.79 / Chapter 3.2.12 --- Statistical Analysis --- p.79 / Chapter 3.3 --- Results --- p.79 / Chapter 3.3.1 --- Downregulation of CFTR is associated with upregulation of COX-2 in mice cryptorchidism model, mice testes hyperthermia model, and CF mice testes --- p.79 / Chapter 3.3.2 --- Negative regulation of COX-2 by CFTR is mediated by NF-κB --- p.81 / Chapter 3.3.3 --- Decreased tight junction proteins expression and increased anchoring junction proteins expression in cryptorchid testes. --- p.81 / Chapter 3.3.4 --- Elevation of culture temperature results in downregulation of CFTR and upregulation of COX-2 in primary cultured rat sertoli cells --- p.82 / Chapter 3.3.5 --- Defect of functional CFTR leads to increased COX-2 expression. --- p.83 / Chapter 3.3.6 --- CFTR regulates TJ protein expression and TJ formation through NF-κB/COX-2/PGE₂. --- p.83 / Chapter 3.4 --- Discussion --- p.100 / Chapter 3.5 --- Conclusion --- p.104 / Chapter 4 --- Chapter 4: General Discussion --- p.105 / Chapter 4.1 --- The immunosuppressive function of PGE₂ in CF lung disease and cryptorchidism-induced infertility. --- p.105 / Chapter 4.2 --- Importance of CFTR/ NF-κB /COX-2/PGE₂ pathway in inflammation-based diseases. --- p.106 / Chapter 4.3 --- Possible implications of CFTR/NF-κB /COX-2/PGE₂ pathway in cancer --- p.107 / Chapter 4.4 --- Concluding remarks --- p.108
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