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The role of cystic fibrosis transmembrane conductance regulator in insulin secretion in pancreatic islet β-cells. / Role of cystic fibrosis transmembrane conductance regulator in insulin secretion in pancreatic islet beta-cells / CUHK electronic theses & dissertations collectionJanuary 2013 (has links)
囊性纖維化(CF)是由囊性纖維化跨膜電導調節器(CFTR)的突變引起的一種隱性遺傳病。CF病人的肺、肝、胰腺、腸道與生殖道受到嚴重影響,其中有50%的成年病人患有糖尿病。由CF引起的糖尿病被稱為CF相關糖尿病(CFRD), 关于它的病因至今仍然存有爭議。2007年,人們發現CFTR在分泌胰島素的胰島β細胞上有表達。儘管如此,β細胞上的CFTR与糖尿病发病的关系却一直被忽略。我們的研究目標是闡述β細胞上的CFTR在胰島素分泌中的作用。 / 在β細胞上,葡萄糖刺激的胰島素分泌伴隨著複雜的電活動,這種電活動被描述為細胞膜電位去极化疊加的動作電位的爆發。葡萄糖引起的ATP敏感的鉀離子通道(K[subscript Asubscript Tsubscript P])的關閉被普遍認為是β細胞去極化的初始事件,初始的去極化啟動了電壓依賴的鈣離子通道,由此產生的鈣離子內流成為構成動作電位的去極化電流,引起了細胞內鈣離子的震盪,從而引起胰島素的釋放。雖然氯離子電流被認為參與了β細胞去極化電流,但是,人們仍然不能確定是哪一種氯離子通道介導了這個去極化電流。在我們研究的第一部分,CFTR被證明功能性的表達在β細胞上,並且可以被葡萄糖激活。CFTR可以被葡萄糖激活这一性质,在CFTR超表達的CHO 细胞上被進一步驗證。在原代培養的β細胞與β細胞株RIN-5F细胞中的葡萄糖引起的全細胞電流、膜電位的去極化、動作電位的幅度與頻率、鈣震盪和胰島素的分泌可以被CFTR的抑制劑或缺陷所降低。與野生型小鼠相比,CFTR基因敲除的小鼠,禁食之後,具有更高的血糖濃度,然而其胰島素的濃度低。 / 我們研究中的第二部分,利用了數學模型去闡明CFTR 在胰島素分泌的電活動中的角色。結果顯示, CFTR電導的減低可以使細胞的細胞膜去極化,從而導致需要更高的電刺激去引發動作電位,这些結果證明了CFTR對於维持細胞膜電位的貢獻。同時增加細胞內氯離子濃度和CFTR的電導可以引起更大頻率的膜電位的震盪,這一點證明了氯離子對於細胞膜電位震盪有著重要的作用。在数学模型中,CFTR電導的降低可以消除通過改變ATP/ADP值所引起的電火花, 這與我們在試驗中發現的CFTR參與了葡萄糖引起的動作電位是一致的。總而言之,我們的数学模型證明了CFTR對於胰島素的分泌是非常重要的,它通過介導氯離子外流對細胞膜電位的產生貢獻並且參與了電火花的產生,所有這些都進一步驗證了我們在實驗部分的發現。 / 综上所述,現有的研究揭示了CFTR,通過對β細胞膜電位作用與参与了動作電位的產生,在葡萄糖刺激胰島素分泌过程中的鮮為人知的重要角色。這個發現為揭示CFRD的病理機制提供了全新的視角,並且可能為開發治療CFRD的方法帶来了曙光。 / Cystic fibrosis (CF) is a recessive autosomal genetic disease resulted from mutations of cystic fibrosis transmembrane conductance regulator (CFTR). CF affects critically the lung, liver, pancreas, intestine and reproductive tract. CF patients also exhibit a high percentage of diabetes, which almost reach 50% in adult. The pathological cause of diabetes in CF patients, also called CF related diabetes (CFRD), is still controversial. It has been reported that CFTR expressed in the islet β cells, which is responsible for insulin secretion. However, the exact role of CFTR in islet β-cell and its relation to diabetes have been ignored. The present study aims to elucidate the role of CFTR in the process of insulin secretion by pancreatic islet β cells. / Glucose-stimulated insulin secretion is associated with a complex electrical activity in the pancreatic islet β-cell, which is characterized by a slow membrane depolarization superimposed with bursts of action potentials. Closing ATP-sensitive K⁺ channels (K[subscript Asubscript Tsubscript P]) in response to glucose increase is generally considered the initial event that depolarizes the β-cell membrane and activates the voltage-dependent Ca²⁺ channels, which constitutes the major depolarizing component of the bursting action potentials giving rise to the cytosolic calcium oscillations that trigger insulin release. While Cl⁻ has been implicated in an unknown depolarization current of the β-cell, the responsible Cl⁻ channel remains unidentified. In the first part of our study, we show functional expression of CFTR and its activation by glucose in the β-cell. Activation of CFTR by glucose was also demonstrated in CHO cell over-expression system. The glucose-elicited whole-cell currents, membrane depolarization, electrical bursts (both magnitude and frequency), Ca²⁺ oscillations and insulin secretion could be abolished or reduced by inhibitors/knockdown of CFTR in primary mouse β-cells or RIN-5F β-cell line, or significantly attenuated in isolated mouse islet β-cells from CFTR mutant mice compared to that of wildtype. Significantly increased blood glucose level accompanied with reduced level of insulin is found in CFTR mutant mice compared to the wildtype. The results strongly indicate a role of CFTR in the process of insulin secretion. / In the second part of our study, mathematical model is built up to clarify the role of CFTR in the electrical activity during insulin secretion. It is shown that reduction of CFTR conductance hyperpolarizes the membrane of the β-cell, for which it requires a larger electrical stimulus to evoke an action potential, indicating the contribution of CFTR to the membrane potential as demonstrated by our experimental results. Increase in intracellular Cl⁻ concentration and the conductance of CFTR result in higher frequency of membrane potential oscillations, demonstrating that Cl⁻ is crucial for the membrane potential oscillations. The electrical spikes induced by increase of ATP/ADP in the model are abolished by decreasing CFTR conductance, which is consistent with our findings that CFTR is involved in the generation of action potentials induced by glucose. In other word, our model demonstrates that CFTR is crucial for insulin secretion by its contribution to membrane potential and participating in the generation of electrical spikes via conducting Cl⁻ efflux, which confirms our findings in the experimental study. / Taken together, the present study reveals a previously unrecognized important role of CFTR in glucose-stimulated insulin secretion via contributing to the membrane potential and the participating in the generation of action potential in islet β cells. This finding sheds new light into the understanding of the pathogenesis of CFRD and may provide grounds for the development of new therapeutic approaches for CFRD. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Guo, Jinghui. / "December 2012." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 156-164). / 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.iii / Acknowledgement: --- p.v / LIST OF PUBLICATIONS --- p.vi / Declaration --- p.viii / ABBREVIATIONS --- p.xi / LIST OF FIGURES --- p.xiii / Chapter Chapter 1: --- General introduction --- p.1 / Chapter 1.1 --- The function of islet β cells and diabetes --- p.1 / Chapter 1.1.1 --- The introduction of the pancreas --- p.1 / Chapter 1.1.2. --- Glucose metabolism and blood glucose regulation --- p.6 / Chapter 1.1.2.2 --- Blood glucose regulation --- p.7 / Chapter 1.1.3 --- Insulin secretion by the islet β cell --- p.10 / Chapter 1.1.4 --- Diabetes --- p.14 / Chapter 1.2 --- Cystic fibrosis-related diabetes --- p.17 / Chapter 1.2.1 --- Cystic fibrosis --- p.17 / Chapter 1.2.2 --- CFTR --- p.19 / Chapter 1.3 --- Mathematical model for insulin secretion --- p.25 / Chapter 1.4 --- Aim and hypothesis --- p.27 / Chapter 1.4.1 --- CFTR may be activated by glucose --- p.27 / Chapter 1.4.2 --- Activation of CFTR may depolarize the membrane potential --- p.28 / Chapter 1.4.3 --- CFTR-mediating Cl-efflux may be involved in the generation of electrical spikes --- p.28 / Chapter 1.4.4 --- Calcium oscillation depends on CFTR --- p.28 / Chapter 1.4.5 --- Insulin secretion --- p.29 / Chapter 1.5 --- Approaches to test the hypothesis --- p.29 / Chapter Chapter 2: --- Materials and Methods --- p.31 / Chapter 2.1 --- Cell culture --- p.31 / Chapter 2.1.1 --- RIN-5F cell --- p.31 / Chapter 2.1.2 --- CHO cell --- p.31 / Chapter 2.2 --- Islet isolation and culture --- p.32 / Chapter 2.3 --- CFTR knockdown --- p.33 / Chapter 2.4 --- Western blot --- p.35 / Chapter 2.5 --- Immunofluorescence --- p.37 / Chapter 2.6 --- Membrane potential (Vm) measurement --- p.38 / Chapter 2.7 --- Intracellular chloride imaging --- p.39 / Chapter 2.8 --- Intracellular calcium imaging --- p.40 / Chapter 2.9 --- Patch-clamp --- p.40 / Chapter 2.10 --- Blood glucose measurement --- p.42 / Chapter 2.11 --- Insulin ELISA --- p.42 / Chapter 2.12 --- Statistics --- p.42 / Chapter Chapter 3: --- Contribution of CFTR on the eletrophysiological properties in insulin secretion --- p.43 / Chapter 3.1 --- Introduction --- p.43 / Chapter 3.2 --- Results --- p.45 / Chapter 3.2.1 --- Functional expression of CFTR in mouse islet β cells --- p.45 / Chapter 3.2.2 --- CFTR activation by glucose --- p.46 / Chapter 3.2.3 --- Involvement of CFTR in the maintenance of membrane potential of islet β cells --- p.47 / Chapter 3.2.4 --- CFTR is involved in the generation of spikes induced by glucose --- p.50 / Chapter 3.2.5 --- Generation of spikes burst in the β cell depends on intracellular chloride. --- p.52 / Chapter 3.2.6 --- Inhibition/mutation of CFTR attenuates calcium oscillation induced by glucose --- p.53 / Chapter 3.2.7 --- Inhibition/mutation of CFTR impairs insulin secretion --- p.53 / Chapter 3.3 --- Discussion --- p.71 / Chapter Chapter 4: --- Mathematical model for the role of CFTR in the process of insulin secretion in islet β cell --- p.74 / Chapter 4.1 --- Introduction to the mathematical modeling in the process of insulin secretion --- p.74 / Chapter 4.2 --- Methods --- p.77 / Chapter 4.2.1 --- Components in the model --- p.77 / Chapter 4.2.2 --- Assumptions and approaches in modeling --- p.78 / Chapter 4.2.3 --- Modeling ion channels and transporters --- p.79 / Chapter 4.2.3.1 --- KATP channel --- p.79 / Chapter 4.2.3.2 --- Sodium channel --- p.82 / Chapter 4.2.3.3 --- Voltage Dependent calcium channel --- p.83 / Chapter 4.2.3.4 --- NCX --- p.84 / Chapter 4.2.3.5 --- Na-K pump --- p.85 / Chapter 4.2.3.6 --- Kv channel --- p.87 / Chapter 4.2.3.7 --- Ca pump --- p.88 / Chapter 4.2.3.9 --- CFTR --- p.90 / Chapter 4.2.3.10 --- NKCC --- p.91 / Chapter 4.3 --- Results --- p.93 / Chapter 4.3.1 --- Role CFTR in regulation of the basal membrane potential in β cells --- p.93 / Chapter 4.3.2 --- Role of intracellular chloride concentration in the burst spikes induced by glucose --- p.95 / Chapter 4.3.3 --- Role of CFTR in the burst spikes induced by glucose --- p.96 / Chapter 4.4 --- Discussion --- p.105 / Chapter Chapter 5: --- General discussion and conclusion --- p.109 / Chapter 5.1 --- General discussion --- p.109 / Chapter 5.1.1 --- Role of CFTR in endocrine pancreas and diabetes --- p.109 / Chapter 5.1.2 --- Role of CFTR as a cell metabolic sensor --- p.111 / Chapter 5.1.3 --- Role of CFTR in excitable cells --- p.113 / Chapter 5.2 --- Conclusion --- p.114 / Appendix A --- p.115 / Appendix B --- p.118 / Reference: --- p.156
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Interaction of CFTR with AF-6/afadin and Its functional role in colorectal cancer metastasis. / CUHK electronic theses & dissertations collectionJanuary 2012 (has links)
CFTR基因突變或者功能缺失是否導致包括胃腸道在內的各種組織惡性腫瘤的發生風險增加目前仍然是一個充滿爭議的問題。同時,眾所周知,緊密連接分子在腫瘤發生和轉移的過程發揮了關鍵的作用。本論文首次發現了CFTR基因與一種緊密連接分子AF-6/afadin的在人類結直腸腫瘤中的表達水平呈高度相關,并研究了CFTR和AF-6/afadin之間潛在的相互作用及其在結直腸腫瘤轉移中的功能。 / 論文的第一部份首先用實時定量PCR和免疫組織化學的方法比較了CFTR在結直腸腫瘤和正常組織的表達情況,發現CFTR表達水平在腫瘤組織中有顯著的下降。令人感興趣的是,我們同時發現CFTR和AF-6/afadin在腫瘤組織中的表達呈高度正相關,并由此展開了後續的體外實驗,研究對CFTR與AF-6/afadin之間可能的相互聯繫。利用免疫螢光染色和免疫共沉澱的方法,我們發現了這兩種蛋白分子共表達在結直腸腫瘤細胞的接觸面,并存在相互作用。用CFTR突變蛋白的免疫共沉澱實驗進一步發現,這種相互作用需要CFTR分子在細胞膜表面的正確定位及其PDZ結構域結合位點。實驗還發現與CFTR的相互作用加強了AF-6/afadin與細胞骨架蛋白系統的結合。在結直腸腫瘤細胞中CFTR基因敲减导致了AF-6/afadin蛋白定位混亂,從細胞連接位點轉移到細胞漿內,并因此破壞了上皮細胞的緊密性。極性生長細胞的跨上皮電阻降低而滲透性增強的實驗結果證實了CFTR基因敲減導致的上皮細胞緊密性的破壞。同時,AF-6/afadin蛋白水平也隨著CFTR基因敲減而降低,但mRNA水平未發生明顯的改變。蛋白降解系統的抑製劑逆轉了CFTR基因敲減細胞中AF-6/afadin蛋白的減少,提示CFTR基因敲減增加了AF-6/afadin的蛋白降解。這些實驗結果揭示了通過與細胞連接分子AF-6/afadin的相互作用以及調節,CFTR可能在上皮細胞極性的調節以及腫瘤發展過程中起重要作用。 / 論文的第二部份研究了CFTR和AF-6/afadin在結直腸腫瘤細胞上皮細胞間充質化(EMT)和轉移過程中的功能及機制。我們之前的工作已經揭示抑制CFTR的功能可以誘導結直腸腫瘤LIM1863細胞的EMT過程。本研究在另外三株不同的結直腸腫瘤細胞(SW480,SW1116和HRT-18)中進一步證實了抑制CFTR誘導的EMT過程。細胞形態轉變,上皮細胞標誌物的下調,間充質細胞標誌物的上調以及受損的上皮細胞緊密性均證實了對CFTR的抑制可以在這三種細胞中成功誘導EMT的發生。我們發現在以上所有細胞EMT的過程中,AF-6/afadin的蛋白表達水平都發生了顯著的下調。在HRT-18細胞中過表達AF-6/afadin,可以逆轉由CFTR抑製劑誘導的上皮細胞標誌分子的下調和間充質標誌分子的上調,表明抑制CFTR誘導的EMT過程是由AF-6/afadin參與介導的。此外,CFTR基因敲減導致結直腸腫瘤細胞的惡性表型強化,包括減弱的細胞粘附性,增強的貼壁依賴性生長、侵襲和遷移。另外,CFTR基因敲減激活了ERK的磷酸化,過表達AF-6/afadin可以阻斷ERK途徑的激活。CFTR基因敲減而增強的細胞侵襲性也可以被外源性AF-6/afadin或者ERK途徑的抑製劑U0126完全逆轉,提示作為AF-6/afadin的下游靶信號,ERK介導了CFTR在腫瘤侵襲中的作用。更重要的是,我們分析了CFTR和AF-6/afadin的表達水平與結直腸癌病人腫瘤進展的關係,發現在嚴重TNM腫瘤分期或者有腫瘤遠處轉移的病人中CFTR的表達水平顯著低於輕型分期或未发生转移的病人中的水平,而且CFTR和/或AF-6/afadin低表達的病人的預後更差。這些實驗結果顯示CFTR的缺失可能通過抑制AF-6/afadin和激活ERK通路而與EMT和結直腸癌癥轉移的過程高度相關。 / 綜上所述,本研究揭示了以往未報道過的CFTR在結直腸腫瘤發病機理中的功能,提示CFTR可以用作一種新的腫瘤的潛在預後指標。 / The question whether mutation or dysfunction of CFTR increases the risk of malignancies in various tissues, including the gastrointestinal tract, remains highly controversial. Meanwhile, it is well-known that adherens junctions play critical roles in the process of cancer development and metastasis. In this thesis we found for the first time a highly correlation between expression levels of CFTR and an adherens junction molecule AF-6/afadin in human colorectal tumours, and investigated the potential interaction between CFTR and AF-6/afadin and their functional roles in the metastasis of colorectal cancer. / In the first section of this thesis, we started our studies with comparing the expression of CFTR between human colorectal tumours and normal colorectal tissues. Real time quantitative PCR and immunohistochemistry results revealed a dramatically reduced CFTR level in the cancer tissues. Intriguingly, we noticed a highly positive correlation between CFTR and AF-6/afadin expression in tumours, which prompted the further in vitro investigation of possible interaction between CFTR and AF-6/afadin. Using immunofluoresent staining and co-immunoprecipitation, we found that the two proteins were colocalized at cell-cell junctions and interacted with each other in colorectal cancer cell lines. Further Co-IP experiments performed with CFTR mutations revealed that this protein interaction requires the proper localization of CFTR in cell membrane and its PDZ-interacting domain. Moreover the interaction with CFTR strengthens the binding of AF-6/afadin to the cytoskeleton system. Knockdown of CFTR in colorectal cancer cells resulted in the disorganized localization of AF-6/afadin protein from junctional sites to the cytoplasm and impaired epithelial tightness, which was confirmed by significantly reduced transepithelial resistance and increased permeability of polarized cells. Meanwhile, the protein level of AF-6/afadin was down-regulated in CFTR-knockdown cells, while no significant changes were detected at the mRNA level. Protein degradation inhibitor reversed the repression of AF-6/afadin protein in CFTR knockdown cells, suggesting the protein degradation of AF-6/afadin was increased by CFTR knockdown. These data revealed that CFTR interacts with and regulates the cell adhesion molecular AF-6/afadin in colorectal cells, which may be important in the regulation of epithelial cell polarity and cancer development. / In the second section of this thesis, we studied the functional roles and mechanisms of CFTR and AF-6/afadin in the epithelial-mesenchymal transition (EMT) and metastasis of human colorectal cancer cells. Our previous work has revealed inhibition of CFTR can induce EMT in a colorectal cancer cell line, LIM1863. This study further confirmed the induction of EMT by inhibiting CFTR in several other colorectal cancer cell lines (SW480, SW1116 and HRT-18), which was evaluated by morphological changes, down-regulation of epithelial markers or up-regulation of mesenchymal markers, and impaired epithelial cell tightness. In all these cell lines, we found that the protein levels of AF-6/afadin were significantly reduced. Over-expression of AF-6/afadin in HRT-18 cells reversed the down-regulated epithelial markers and up-regulated mesenchymal markers induced by CFTR inhibition, indicating that the CFTR inhibition-induced EMT is mediated by AF-6/afadin. Moreover, knockdown of CFTR in HRT-18 or RKO cells resulted in enhanced malignant phenotypes, including decreased cell adhesion, increased anchorage-independent cell growth, invasion, and migration. In addition, extracellular signal-regulated kinase (ERK) phosphorylation was activated by CFTR knockdown, which was abolished by over-expression of AF-6/afadin. The enhanced invasiveness of CFTR knockdown cells was also completely inhibited by either exogenous AF-6/afadin or ERK inhibitor, U0126, suggesting that ERK, the downstream target of AF-6/afadin, is involved in mediating the effect of CFTR in cancer invasion. More importantly, we analyzed the association of CFTR and AF-6/afadin expression levels with tumour progression of patients with colorectal cancer, and revealed that CFTR expression was significantly lower in patients with more severe TNM stage or with metastasis to distant organs than those with milder stage or with no metastasis. The prognosis was poorer in patients with lower expression of CFTR and/or AF-6/afadin than those with higher expressions. These data showed that dysfunction of CFTR is highly associated with EMT and colorectal cancer metastasis, probably via repression of AF-6/afadin and activation of ERK pathways. / In summary, the present study has revealed a previously undefined role of CFTR in the pathogenesis of colorectal cancer and indicated its potential as a new prognostic indicator. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Sun, Tingting. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 113-127). / 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 / 中文摘要 --- p.iv / Publications --- p.vi / Conference Abstract --- p.vii / Declaration --- p.viii / Acknowledgements --- p.x / List of Figures --- p.xi / List of Tables --- p.xiii / List of Abbreviations --- p.xiv / Chapter Chapter 1 --- General Introduction --- p.1 / Chapter 1.1. --- Colorectal Cancer --- p.1 / Chapter 1.1.1. --- Structure of Human Normal Colon and Rectum Epithelium --- p.1 / Chapter 1.1.2. --- Staging of Colorectal Cancer --- p.3 / Chapter 1.1.3. --- Metastasis of Colorectal Cancer --- p.3 / Chapter 1.1.4. --- K-Ras mutation and It Downstream Pathways in Colorectal Cancer Metastasis --- p.11 / Chapter 1.1.5. --- Prognosis of Colorectal Cancer --- p.14 / Chapter 1.2. --- Epithelial Cell Junctional Complexes --- p.14 / Chapter 1.2.1. --- Junctional Complexes and Epithelial Cell Polarity --- p.15 / Chapter 1.2.2. --- Classic Cadherin-catenin Complex --- p.17 / Chapter 1.2.3. --- Novel Nectin-afadin Complex --- p.19 / Chapter 1.2.4. --- Cell Polarity and Cancer Progression --- p.23 / Chapter 1.3. --- Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) --- p.24 / Chapter 1.3.1. --- Structure of CFTR --- p.24 / Chapter 1.3.2. --- Mutations of CFTR --- p.24 / Chapter 1.3.3. --- Functions of CFTR --- p.26 / Chapter 1.3.4. --- Cancer Risk of CF Patients --- p.33 / Chapter 1.4. --- Hypothesis and Aims --- p.34 / Chapter Chapter 2 --- Materials and Methods --- p.35 / Chapter 2.1. --- Materials --- p.35 / Chapter 2.1.1. --- Reagents and Chemicals --- p.35 / Chapter 2.1.2. --- Antibodies --- p.35 / Chapter 2.1.3. --- Primers --- p.35 / Chapter 2.1.4. --- Solutions and Buffers --- p.35 / Chapter 2.1.5. --- Human Specimens --- p.36 / Chapter 2.2. --- Methods --- p.36 / Chapter 2.2.1. --- Cell Culture --- p.36 / Chapter 2.2.2. --- Transfection --- p.36 / Chapter 2.2.3. --- Selection of Stable Clones --- p.40 / Chapter 2.2.4. --- RNA Extraction and RT-PCR --- p.40 / Chapter 2.2.5. --- Quantitative Real Time PCR --- p.41 / Chapter 2.2.6. --- Protein Extraction and Western Blotting --- p.42 / Chapter 2.2.7. --- Immunostaining --- p.45 / Chapter 2.2.8. --- In vitro Cell Functional Assays --- p.46 / Chapter 2.2.9. --- Epithelial Tightness Measurement --- p.48 / Chapter 2.2.10. --- Statistical Analysis --- p.49 / Chapter Chapter 3 --- Interaction of CFTR with AF-6/afadin and Its Importance in Maintaining Colorectal Epithelial Cell Polarity --- p.50 / Chapter 3.1. --- Introduction --- p.50 / Chapter 3.2. --- Objectives --- p.53 / Chapter 3.3. --- Experimental plan --- p.54 / Chapter 3.4. --- Results --- p.55 / Chapter 3.4.1. --- The expression of CFTR and AF-6/afadin is decreased and positively correlated in human colorectal cancer --- p.55 / Chapter 3.4.2. --- CFTR colocalizes and interacts with AF-6/afadin in human colorectal cancer cells --- p.58 / Chapter 3.4.3. --- PDZ binding motif and membrane localization of CFTR are necessary for the interaction between CFTR and AF-6/afadin --- p.64 / Chapter 3.4.4. --- Knockdown of CFTR interferes with cell junction formation in colorectal cancer cells --- p.66 / Chapter 3.5. --- Discussion --- p.71 / Chapter Chapter 4 --- CFTR as a Suppressor and Prognosis Indicator of Metastasis in Human Colorectal Cancer --- p.77 / Chapter 4.1. --- Introduction --- p.77 / Chapter 4.2. --- Objectives --- p.80 / Chapter 4.3. --- Experimental plan --- p.81 / Chapter 4.4. --- Results --- p.82 / Chapter 4.4.1. --- CFTR inhibition-induced EMT in colorectal cancer cells involves AF-6/afadin --- p.82 / Chapter 4.4.2. --- Knockdown of CFTR aggravates malignant phenotype of colorectal cancer cells --- p.86 / Chapter 4.4.3. --- AF-6/afadin mediates the effect of CFTR on cell invasion in colon cancer through ERK --- p.91 / Chapter 4.4.4. --- CFTR and AF-6/afadin expression is correlated with the prognosis of colorectal cancer --- p.97 / Chapter 4.5. --- Discussion --- p.100 / Chapter Chapter 5 --- General Discussion and Conclusion --- p.105 / Chapter 5.1. --- The diversified roles of CFTR in epithelial cells --- p.105 / Chapter 5.2. --- The unfolding relationship between CFTR and cancer development --- p.107 / Chapter 5.3. --- Future studies --- p.109 / Chapter 5.4. --- Conclusions --- p.112 / Reference List --- p.113 / Chapter Appendix A --- Reagents and Chemicals --- p.128 / Chapter Appendix B --- Antibody List --- p.131 / Chapter Appendix C --- Primer List --- p.132 / Chapter Appendix D --- Solution Recipe --- p.133
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Study of interactions between endocrine and exocrine pancreas mediated by microparticles in cystic fibrosis : impact of infections and immunosuppressive drugs / Etude des interactions entre le pancréas endocrine et exocrine promus par les microparticules dans la mucoviscidose : impact des infections et des immunosuppresseursConstantinescu, Andrei 29 September 2014 (has links)
Ce travail scientifique a abordé la problématique de la communication cellulaire entre le pancréas exocrine et endocrine dans la mucoviscidose. La contribution des infections pulmonaires chroniques et des traitements immunosuppresseurs sur la dégénerescence pancréatique a été aussi étudiée. Les résultats obtenus ont montré que le LPS disséminé par des infections récurrentes peut cibler les cellules pancréatiques exocrines, en conduisant à la formation des microparticules membranaires qui sont nuisibles pour la survie et le fonctionnement des cellules endocrines. Dans cette communication intercellulaire, la protéine CFTR est un médiateur essentiel de la sévérité des signaux délivrés par les microparticules et de la réponse cellulaire à l'inflammation du pancréas, en participant à l'équilibre de la sécrétion d'insuline des cellules endocrines. En outre, les données ont mis en évidence que l'administration prolongée d’immunosuppresseurs chez les patients greffés pourrait différemment induire l'apoptose de manière dépendante de la mitochondrie, cela en favorisant l'entrée des cellules en sénescence prématurée, un état métabolique du dysfonctionnement cellulaire. / This scientific work tackled the issue of the communication between exocrine and endocrine pancreas in cystic fibrosis. Also, the contribution of recurrent lung infections and immunosuppressive therapy to the pancreatic cell degenerescence was studied in vitro. Results obtained showed that disseminated LPS released by recurrent infections could target pancreatic exocrine cells, leading to the formation of membrane microparticles that are deleterious for endocrine cell survival and function. In this intercellular cross-talk, CFTR is a critical mediator for the severity of the MP-delivered signals and for the pancreatic cell response to inflammation, also participating to the balance of insulin secretion of endocrine cells. Furthermore, data evidenced that long-term administration of immunosuppressive drugs in grafted patients may differently induce apoptosis in a mitochondrial-dependent fashion, possibly favoring cells to enter premature senescence, which is a metabolic state of cellular dysfunction.
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Gating of cystic fibrosis transmembrane conductance regulator (CFTR) chloride channels by nucleoside triphosphatesZeltwanger, Shawn January 1998 (has links)
Thesis (Ph. D.)--University of Missouri--Columbia, 1998. / Typescript. Vita. Includes bibliographical references (l. 140-148). Also available on the Internet.
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Incidenicia da fibrose cistica calculada atraves de portadores do alelo ?F508 no Nordeste e Sudeste do Brasil / Cystic fibrosis incidence calculated from heterozygote frequencies in Northeast and Southeast BrazilArruda, Leonardo Vicentini 14 August 2007 (has links)
Orientador: Carmen Silvia Bertuzzo / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-09T09:38:13Z (GMT). No. of bitstreams: 1
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Previous issue date: 2006 / Resumo: A incidência da fibrose cística no Brasil é significativamente variável, com diferenças de até 20 vezes de acordo com o grupo étnico e região geográfica estudada. A população brasileira é composta da mistura de muitos grupos étnicos. Os portugueses começaram a colonização no século XVI. Os holandeses invadiram o nordeste em 1630. Os africanos foram trazidos ao Brasil, numa contínua migração forçada, que perdurou do século XVI ao século XIX. No final do século XIX, tiveram início novos movimentos migratórios, principalmente da Alemanha, Itália, Arábia e Espanha. Durante as três primeiras décadas do século XX, nova corrente migratória ocorreu, principalmente da Itália, Espanha e Portugal Após a segunda guerra mundial, o Brasil recebeu novos imigrantes (japoneses, judeus) compondo esta população. Este estudo gerou os primeiros dados sobre a incidência da FC no nordeste e também foram obtidos novos dados para a região sudeste. Na época do estudo, na cidade de Campinas estão sob atendimento no ambulatório 70 pacientes não aparentados com dois testes de suor alterados. Nestes pacientes, foram triadas as seguintes mutações. ?F508 (50%), G542X (4,29%), R1162X (2,14%), N1303K (1,43%) e R553X (0,71%). A mutação G551D não foi encontrada. A mutação ?F508 também foi analisada em 1.138 mulheres saudáveis, sendo 694 da cidade de Campinas - SP e 444 de João Pessoa ¿ PB com idade média de 26,3 anos (15-39, ±6,8), que participaram voluntariamente de projeto de pesquisa anterior. Nas amostras coletadas em Campinas n=694 não foi encontrado nenhum alelo mutante 0/1.388, o que nos impediu de calcular a incidência nesta cidade através deste método. Dos 888 alelos analisados de João Pessoa, foram encontrados quatro alelos mutantes (p=0,0045). Sabendo que a mutação ?F508 corresponde a aproximadamente 50% dos alelos de indivíduos com FC no Brasil, a freqüência dos alelos causadores da FC foi estimada utilizando a proporção: (0,0045/0,5)=0,0090. Com isso, para a cidade de João Pessoa a incidência estimada desta doença autossômica recessiva é de 1:12.321 indivíduos. Esta incidência é similar à encontrada por afro-brasileiros, entretanto difere por exemplo, da encontrada na população do RS. Quando utilizamos o método de cruzamento de dados étnicos das duas regiões estudadas com dados literários da doença nos diferentes grupos étnicos, na cidade de Campinas a incidência da FC ficaria em 1/4.434 e na cidade de João Pessoa ficaria 1/6.087 / Abstract: The incidence of the Cystic Fibrosis (CF) is significantly variable in Brazil, with differences larger than 20 fold, according with the ethnic group and geographic studied region. Brazilian population is composed by ethnic admixture. Portuguese started colonization in the 16th century. The Netherlander invaded the northeast in 1630. The Africans were brought to Brazil, in a continuous forced migration, which lasted from 16th to 19th centuries. In the 19th century, new migratory movements have begun from Germany, Italy, Arab and Spain. In the first three decades of the 20th century, started a new migratory flow, mainly from Italy, Spain and Portugal. After the World War II, Brazil received additional immigrants (Japanese, Jewish) compounding its population. These studies generated the first data about the CF incidence on the Brazilian northeast and also were obtained new data about the southeast region. At the time of this study, 70 non related patients were attended at the local CF center in Campinas, with two positive sweat tests in the city of Campinas-SP. On theses patients were screened the following mutations: ?F508 (50%), G542X (4.29%), R1162X (2.14%), N1303K (1.43%) and R553X (0.71%). The mutation G551D wasn¿t found. The ?F508 mutation was also analyzed in 1,138 healthy voluntary women, 694 from Campinas ¿ SP and 444 from João Pessoa ¿ PB, with average age of 26.3 years (15-39, ±6.8), who previously participated from another research. In the samples collected in Campinas ¿ SP n=694 wasn¿t found any mutated allele 0/1,388 and so, we wasn¿t able to make any incidence calculation through this method. In the 888 alleles from João Pessoa, four carry the ?F508 mutation (p=0.0045). Knowing that this mutation accounts for approximately 50% of the FC patients alleles in Brazil, the incidence of the CF in this region was estimated using the proportion: (0.0045/0.5)=0.009. Thus, the estimated incidence of this recessive disease in João Pessoa was 1:12,321. This incidence is similar to the found in African-Brazilians, although differs for example, to the found on the RS population. When we use the method of crossing ethnic data of both studied regions with literary data of the disease in the different ethnic groups, in the city of Campinas, the incidence of the CF would be in 1/4,434 and in the city of João Pessoa would be 1/6,087 / Mestrado / Mestre em Farmacologia
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Freqüência de polimorfismos do gene CFTR em pacientes portadores de pancreatite crônica alcoólica / Polymorphisms in patients with alcoholic chronic pancreatitisMarianges Zadrozny Gouvêa da Costa 19 March 2008 (has links)
A dependência de álcool acomete de 10 a 12% da população mundial, estando a associação entre uso abusivo do álcool e pancreatite crônica bem estabelecida. A suscetibilidade pancreática ao álcool é variável e apenas 5 a 10% dos etilistas crônicos desenvolvem pancreatite crônica, sendo o papel dos fatores genéticos neste processo praticamente desconhecido. O gene CFTR (cystic fibrosis transmenbrane conductance regulator) codifica proteína que funciona na membrana plasmática de células epiteliais e que tem papel chave na função pancreática exócrina normal, promovendo a regulação, da secreção de fluídos e bicarbonato, importantes para a diluição e a alcalinização do suco pancreático. Quando a função desta proteína é inadequada, observa-se obstrução de pequenos ductos por rolhas protéicas. Várias pesquisas buscam documentar a associação fibrose cística - pancreatite crônica, porém os resultados são conflitantes. Este trabalho pesquisou a freqüência de polimorfismos no trato de politiminas e poli TGs no intron 8 do gene CFTR em pacientes portadores de pancreatite crônica alcoólica. Foram estudados três grupos de pacientes: Grupo A - adultos alcoolistas com diagnóstico de pancreatite crônica; Grupo B - adultos alcoolistas sem pancreatopatia ou cirrose hepática e Grupo C - adultos sadios não alcoolistas. O DNA genômico para análise do gene CFTR foi extraído do sangue periférico, pesquisando-se a freqüência de polimorfismos no trato de politiminas e poli TGs no intron 8. O genótipo 5T/7T foi mais encontrado no grupo A do que no B (p = 0,0481), não havendo diferença quando comparados os grupos A e C (p = 0,1317). Pacientes com pancreatite crônica por álcool com o genótipo 5T/7T tiveram menor incidência de diabetes melito do que aqueles com outros genótipos (p = 0,0465). A combinação de haplótipos 10TG 7T / 11TG 7T foi mais freqüente nos grupos B e C do que no A e poderia, eventualmente, ser um fator protetor contra o desenvolvimento da pancreatite crônica. (p = 0,0080 e 0,0162). Em conclusão, há diferenças no intron 8 do gene CFTR em pacientes com pancreatite crônica alcoólica, quando comparados com alcoolistas não pancreatopatas e indivíduos com o genótipo 5T/7T teriam maior risco de desenvolver pancreatite crônica quando se tornam alcoolistas crônicos. / The alcohol dependence affects from 10 to 12% of the world-wide population, being the association between alcohol abuse and chronic pancreatitis well established. The pancreatic susceptibility to the alcohol is only 5 to 10%, being the paper of the genetic factors practically unknown. The CFTR gene (cystic fibrosis transmenbrane conductance regulator) codifies a protein that functions in the epithelial cells and has a role in pancreatic exocrine function, promoting regulation of the secretion of fluids and bicarbonate, important for the dilution and the alcalinization of the pancreatic juice. When the function of this protein is inadequate, blockage of small ducts occurs. Some research regist the association cystic fibrosis - chronic pancreatite, however the results are conflicting. This work searched the frequency of polymorphisms in the polyT and poly TGs tracts in intron 8 of CFTR gene in patients with alcoholic chronic pancreatitis. Three groups of patients have been studied: Group A - adult alcoholics with chronic pancreatitis; Group B - adult alcoholics without pancreatic disease or hepatic cirrhosis and Group C - non alcoholics healthy adults. DNA analysis of CFTR gene was made after extraction from peripheral blood samples. The 5T/7T genotype was more frequently found in group A that in B (p = 0.0481), with no difference when compared to group C (p = 0,1317). Patients with alcoholic chronic pancreatitis and 5T/7T genotype had less incidence of diabetes mellitus that those with other genotypes (p = 0,0465). The haplotype combination 10TG 7T / 11TG 7T was more frequent in groups B and C that in A and it could, eventually, be a protective factor against the development of alcoholic chronic pancreatitis. (p = 0,0080 and 0,0162). In conclusion, we found differences when these tree groups are compared and individuals with 5T/7T genotype would have greater risk to develop chronic pancreatitis if they become alcoholics.
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Fibrose cística = avaliação diagnóstica através da diferença de potencial nasal e sua correlação com duas mutações genéticas / Cystic fibrosis diagnostic evaluation through nasal potential difference and its correlation with two genetic mutationsNg, Ronny Tah Yen, 1979- 23 August 2018 (has links)
Orientador: Eulalia Sakano / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-23T20:48:54Z (GMT). No. of bitstreams: 1
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Previous issue date: 2013 / Resumo: A fibrose cística (FC) é uma doença genética autossômica recessiva, resultante da ausência total na proteína CFTR (Cystic Fibrosis Transmembrane Conductance Regulator), ou de alterações qualitativas ou quantitativas do gene que transcreve esta proteína, em células de diversos órgãos do corpo humano, resultando em inúmeros genótipos e fenótipos desta doença. Em muitos pacientes, o diagnóstico é difícil de ser definido, pelo método clássico de dosagem de sódio e cloro no suor, ou pelo sequenciamento genético, justificando a utilização de novas técnicas de auxílio diagnóstico, como a Diferença de Potencial Nasal (DPN). Este teste proporciona uma forma de avaliação direta e sensível, através do epitélio nasal, do transporte de sódio e cloro das membranas celulares, baseado nas propriedades bioelétricas transepiteliais. O objetivo deste trabalho foi verificar se existe diferença dos valores obtidos no exame de DPN em pacientes com FC em comparação com indivíduos controles saudáveis; e verificar se este teste permite diferenciar pacientes com FC das subclasses funcionais mais graves (I, II, III) das subclasses menos graves (IV, V, VI). Foram incluídos no estudo 15 pacientes FC, 10 com mutações mais graves (grupo A) e 5 com mutações menos graves (grupo B), e 21 controles saudáveis (grupo C). Foram considerados os seguintes parâmetros do teste da DPN: "Finger", PDMax, ?Amilorideo, ?Amilorídeo+livrecloreto e index de Wilchanski. Para a variável "Finger", foi encontrada diferença entre pacientes com FC grupo B - mutações menos graves (classe IV, V ou VI) e indivíduos saudáveis - grupo C. O valor do index de Wilchanski mostrou diferença entre pacientes com FC grupo A - mutações mais graves (classes I, II ou III) e indivíduos saudáveis - grupo C. No nosso estudo, a DPN mostrou valores estatisticamente diferentes entre FC com 2 mutações conhecidas e sujeitos saudáveis. Porém, não conseguiu diferenciar fibrocísticos com mutações mais graves (classes I, II e III) daqueles com mutações consideradas menos graves (classes IV, V e VI) / Abstract: Cystic fibrosis (CF) is an autosomal recessive genetic disease, due to the total absence of protein CFTR (Cystic Fibrosis Transmembrane Conductance Regulator), or due to qualitative or quantitative changes in the gene that transcript this protein in cells of various organs of the human body, resulting in numerous genotypes and phenotypes of the disease. In several patients, the diagnosis is difficult to be defined by the classical method of sodium and chloride dosage in sweat, or by genetic sequencing, justifying the use of new techniques for diagnosis, as the Nasal Potential Difference (NPD). This test provides a way of direct and sensitive assessment of the transport of sodium and chloride ions in cell membranes, via the nasal epithelium, based on transepithelial bioelectric properties. The objective of this work was to verify the difference of the values obtained in the examination of NPD in patients with CF compared with healthy control subjects, and, to verify if this test allows differentiating patients with more severe CF functional subclasses (I, II , III) from patients with less severe CF subclasses (IV, V, VI). This study included 15 CF patients, 10 with more severe mutations (group A) and 5 with less severe mutations (group B), and 21 healthy controls (group C). We considered the following test parameters of NPD: "Finger", PDMax, ?Amiloride, ?Amiloríde+Chloridefree and Wilchanski index. For "Finger" values, it was found difference between patients with CF Group B - less severe mutations (class IV , V or VI) and healthy individuals - group C. The value of Wilchanski index showed difference between group A CF patients, with more severe mutations (class I, II or III) and healthy individuals - group C. In our study, NPD showed statistically different values between CF patients with two known mutations and healthy subjects. However, it was not able to distinguish between CF patients with more severe mutations (class I, II and III) of the CF patientswith less severe mutations (Class IV, V and VI) / Mestrado / Otorrinolaringologia / Mestre em Ciências Médicas
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Hälsoproblem relaterade till cystisk fibros : en litteraturöversikt / Health problems related to cystic fibrosis : a literature reviewManouilenko Rosales, Camilla, Lindström, Jenny January 2021 (has links)
Bakgrund Cystisk fibros är en multisystemsjukdom som främst påverkar lungor, bukspottkörtel och tarm. Sjukdomen påverkar 70 000 till 100 000 personer globalt i världen. Syfte Syftet var att belysa hälsoproblem hos personer med cystisk fibros. Metod Icke systematisk litteraturöversikt med integrerad analys där litteratursökning tillämpas utifrån databasen PubMed. Artiklarna som inkluderades är publicerade mellan 2011 och 2021. Resultat Baserat på dataanalysen av de 16 inkluderade vetenskapliga artiklarna identifierades fyra teman: fysiska, psykiska, sociala och existentiella hälsoproblem med att leva och överleva med diagnosen cystisk fibros. Slutsats Slutsatsen av denna studie visar att cystisk fibros är en sjukdom som har stor inverkan på både kropp och psyke. Patienter har ett livslångt behov av vård och mer forskning behövs på området för att ytterligare bredda kunskapen om sjukdomen. / Background Cystic fibrosis is a multisystem disease which primarily affects lungs, pancreas and the gut. The disease affects 70,000 to 100,000 globally. Aim The aim of this study was to illustrate the health complications present in patients with cystic fibrosis. Method Non-systematic literature review with integrated analysis where literature search is applied based on the databases PubMed. The articles included in this review are published between 2011 and 2021. Results Four themes were identified based on the analysis of 16 scientific articles: physical, mental, social and existential health problems of living and surviving with the diagnosis of cystic fibrosis. Conclusions The conclusion of this study shows that cystic fibrosis is a disease that has a major impact on both physical and mental health. Patients have a lifelong need for care and more research is needed about the subject to further broaden the knowledge of the disease.
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Využití sekvenačních metod nové generace pro objasnění fenotypu podobného CF u pacientů s nejasnou molekulární podstatou onemocnění. / Utilization of new generation sequencing methods to elucidate cystic fibrosis-like phenotype at patients with unclear illness of molecular type.Matějčková, Iva January 2017 (has links)
Cystic fibrosis (CF) is genetically conditioned, autosomal recessive disease that occurs in the European population with a prevalence of about 1:2500 - 1:1800. In this disease we observe a mutation of the CTFR gene with subsequent fault in chloride channels. Such afflicted individuals usually suffer from chronic respiratory problems, pancreatic insufficiency, high concentration of chloride ions in sweat and obstructive azoospermia. Genetic testing of CFTR gene is indicated in individuals who meet the CF clinical picture and a positive sweat test (increased concentration of chlorides in the sweat). Genetic testing of the CFTR gene is usually done by using commercial kits detecting the most common mutations of the CFTR gene in the Czech Republic. If the testing results are negative, it is further performed an MLPA method that captures the larger deletions and duplications of gene, eventually a sequencing of all exons is. Despite the well-established algorithm of the testing, some patients suffering from symptoms of CF are left without genetic findings. Thanks to development of next generation sequencing, it is possible to make the diagnosis of CF more effective and uncover the variants that were not captured by previous methods.
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Caractérisation du statut en vitamine K chez les patients adultes atteints de la fibrose kystiqueBergeron, Cindy 08 1900 (has links)
Les déficiences en vitamines liposolubles sont fréquentes chez les patients atteints de la fibrose kystique (FK), mais la fréquence et les implications cliniques d’un déficit en vitamine K sont peu documentées. L’objectif de cette étude était d’évaluer les déficiences en vitamines liposolubles des patients adultes atteints de la FK et d’examiner les associations entre la concentration sérique de la vitamine K1 et le statut nutritionnel, la fonction pulmonaire et la tolérance au glucose.
Nous avons effectué une étude transversale chez des patients adultes (≥ 18 ans, n =168) atteints de la FK. Les concentrations sériques de vitamine K1 ont été mesurées par chromatographie liquide à haute performance (HPLC) sur les prélèvements à jeun, obtenus lors du test d’hyperglycémie provoquée par voie orale (HPGO) visant à dépister le diabète associé à la FK. Les patients ont été classés selon leur taux de vitamine K1 (sous-optimal défini comme < 0,30 nmol/L).
Des taux sanguins sous-optimaux de vitamine K1 ont été observés chez 66 % des patients atteints de la FK. Les patients ayant un statut sous-optimal en vitamine K1 ont un risque plus élevé de colonisation par la bactérie Pseudomonas aeruginosa, un indice de masse corporelle (IMC) plus bas et sont plus susceptibles d'avoir une insuffisance pancréatique exocrine. Une régression multivariée n'a pas réussi à démontrer des relations significatives entre les variables cliniques et les niveaux de vitamine K1 transformés en log. En utilisant un seuil pour la vitamine K1, nous avons montré des mesures réduites de la sécrétion d'insuline chez les patients ayant un statut en vitamine K1 inférieur à 0,30 nmol/L.
Une association claire entre un statut sous-optimal en vitamine K1 et les mesures de la dysglycémie et de la sécrétion d'insuline n’a pas pu être démontrée. Nous soulignons les associations potentielles d'une carence légère en vitamine K avec une colonisation par la bactérie Pseudomonas et un IMC plus bas, bien que celles-ci doivent être validées dans des études prospectives.
Ce mémoire contribue à l’amélioration des connaissances sur le statut en vitamine K chez les adultes atteints de la FK. / Patients with Cystic Fibrosis (CF) are at high risk of fat-soluble vitamin deficiencies, even with supplementation. The contribution of fat-soluble deficiencies to respiratory and endocrine pathophysiology in CF has been inadequately characterized. The aim of this observational study was to assess vitamin deficiencies in adult patients with CF, in the Montreal Cystic Fibrosis Cohort (MCFC). In particular, given the lack of evidence around the impact of vitamin K in CF, the purpose was to look at how vitamin K1 related to CF-related diabetes (CFRD) and whether there was a negative association between a suboptimal vitamin K1 status and measures of dysglycemia.
We performed a cross-sectional study with baseline data from adult patients with CF (≥ 18 years old, n = 168). Serum vitamin K1 was measured with high performance liquid chromatography (HPLC) on fasting samples from an oral glucose tolerance test (OGTT) used for CFRD screening. Patients were categorized according to vitamin K levels (suboptimal defined as <0.30 nmol/L).
Suboptimal vitamin K1 levels were observed in 66 % of patients. Patients with a suboptimal vitamin K1 status have a higher risk of colonization with Pseudomonas aeruginosa, lower BMI and were more likely to have exocrine pancreatic insufficiency. Multivariate regression failed to demonstrate significant relationships between clinical variables and log-transformed vitamin K1 levels. Using an established threshold for vitamin K1, we did show reduced OGTT-derived measures of insulin secretion in patients with a vitamin K1 status below 0.30 nmol/L.
We failed to demonstrate a clear association between a suboptimal vitamin K status and measures of dysglycemia and insulin secretion. We highlight the potential associations of mild vitamin K deficiency with pseudomonal colonization and lower BMI, although these need to be validated in prospective studies.
This study contributes to improving knowledge on vitamin K status in patients with CF.
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