Poon, Chui Wa Christina. / "August 2011." / Thesis (M.Phil.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 123-131). / Abstracts in English and Chinese. / ABSTRACT --- p.i / 論文摘要 --- p.vi / ACKNOWLEDGEMENTS --- p.ix / PUBLICATIONS --- p.x / Abstracts --- p.x / ABBREVIATIONS --- p.xii / Chapter 1. --- GENERAL INTRODUCTION --- p.1 / Chapter 1.1. --- Diabetes --- p.1 / Chapter 1.1.1. --- Overview --- p.1 / Chapter 1.1.2. --- Diagnostic Criteria of Type-2 Diabetes --- p.2 / Chapter 1.1.3. --- Type-2 Diabetes (T2DM) --- p.3 / Chapter 1.1.3.1. --- Impaired Insulin Synthesis and Insulin Secretory Defects in Type-2 Diabetes --- p.3 / Chapter 1.1.3.2. --- β-Cell Dysfunction --- p.5 / Chapter 1.1.3.3. --- Insulin Resistance --- p.5 / Chapter 1.1.4. --- Glucose Toxicity --- p.6 / Chapter 1.1.4.1. --- Fasting Hyperglycemia --- p.8 / Chapter 1.1.4.2. --- Postprandial Hyperglycemia --- p.8 / Chapter 1.2. --- Oxidative Stress --- p.8 / Chapter 1.2.1. --- ROS and Mitochondria --- p.8 / Chapter 1.2.2. --- ROS Production by Mitochondria --- p.9 / Chapter 1.2.3. --- The Relationship of Glucose Recognition by β-cells and Oxidative Stress --- p.11 / Chapter 1.2.4. --- Important Roles of Glutathione in Pancreatic β-cells and Glutathione Synthesis --- p.14 / Chapter 1.2.5. --- N-acetyl-L-cysteine - A Potential Drug Treatment for Type-2 Diabetes? --- p.17 / Chapter 1.3. --- Role of F-actin Cytoskeleton on Glucose-induced Insulin Secretion --- p.18 / Chapter 1.4. --- Current Clinical Treatments for Type-2 Diabetes Mellitus --- p.21 / Chapter 1.4.1. --- Metformin --- p.22 / Chapter 1.4.2. --- Sulfonylureas --- p.22 / Chapter 1.4.3. --- Thiazolidinediones --- p.23 / Chapter 1.4.4. --- Glinides (Meglitinide Analogues) --- p.23 / Chapter 1.4.5. --- α-Glucosidase (AG) Inhibitors --- p.24 / Chapter 1.4.6. --- Dipeptidyl Peptidase-4 (DPP-4) Inhibitors --- p.24 / Chapter 1.4.7. --- (Clinical) Antioxidant Treatment --- p.24 / Chapter 1.5. --- Animal Models Used in Type-2 Diabetes Research --- p.25 / Chapter 1.6. --- Aims of Study --- p.27 / Chapter 2. --- RESEARCH DESIGN & METHODS --- p.28 / Chapter 2.1. --- Materials --- p.28 / Table 1. Sources and concentrations of drugs tested in this study: --- p.28 / Culture Medium - --- p.29 / General Reagents --- p.29 / Chapter 2.2. --- Isolation of Islets of Langerhans and Single Pancreatic β-Cells --- p.31 / Chapter 2.3. --- Measurement of Mitochondrial ROS Levels --- p.32 / Chapter 2.4. --- Measurement of Islets Insulin Release and Insulin Content --- p.34 / Chapter 2.4.1. --- Preparation of Samples --- p.34 / Chapter 2.4.2. --- Enzyme-Link Immunosorbent Assay (ELISA) --- p.35 / Chapter 2.5. --- Immunocytochemistry --- p.35 / Chapter 2.6. --- Data and Statistical Analysis --- p.37 / Chapter 3. --- RESULTS --- p.38 / Chapter 3.1. --- "Effects of L-NAC, Various Oxidative Stress Inducers/Reducers and Actin Polymerisation/Depolymerisation Inducers on Releasable Insulin Levels and Insulin Contents in Response to Low Glucose (5 mM) and High Glucose (15 mM) of Isolated Pancreatic Islets of (db+/m+) and (db+/db+) Mice" --- p.38 / Chapter 3.1.1. --- Effect of L-NAC on Insulin Secretion and Insulin Contents --- p.38 / Chapter 3.1.2. --- Effect of Cytochalasin B on Insulin Secretion and Insulin Contents --- p.39 / Chapter 3.1.3. --- Effect of 4-Phenyl Butyric Acid on Insulin Secretion and Insulin Contents --- p.43 / Chapter 3.1.4. --- Effect of Ursodeoxycholic Acid on Insulin Secretion and Insulin Contents --- p.46 / Chapter 3.1.5. --- Effect of Hydrogen Peroxide on Insulin Secretion and Insulin Contents --- p.49 / Chapter 3.1.6. --- Effect of Jasplakinolide on Insulin Secretion and Insulin Contents --- p.53 / Chapter 3.1.7. --- Effect of Thapsigargin on Insulin Secretion and Insulin Contents --- p.57 / Chapter 3.1.8. --- Effect of BSO on Insulin Secretion and Insulin Contents --- p.61 / Chapter 3.2. --- "Effects of L-NAC, Various Oxidative Stress Inducers/Reducers and Actin Polymerisation/Depolymerisation Inducers on Mitochondrial ROS Levels in Response to High Glucose (15 mM) Challenge in Isolated Single Pancreatic β-Cells of (db +/m+) and (db +/db +) Mice" --- p.65 / Chapter 3.2.1. --- "Effects of L-NAC (20 mM), 4-Phenyl Butyric Acid (4-PBA) (1 mM), Ursodeoxycholic Acid (UA) (500 μg/ml), H202 (200 μM), Thapsigargin (0.5 μM) and DL-Buthionine-[S,R]-Sulfoximine (BSO) (0.1 μM) Pre-treatments on Mitochondrial ROS Level in Response to High Glucose (15 mM) Challenge" --- p.65 / Chapter 3.2.2. --- "Effects of L-NAC (20 mM), Cytochalasin B (10 μM) and Jasplakinolide (5 μM) Pre-treatments on Mitochondrial ROS Level in Response to High Glucose (15 mM) Challenge_" --- p.76 / Chapter 3.3. --- "Effects of L-NAC, Various Oxidative Stress Inducers/Reducers and Actin Polymerisation/Depolymerisation Inducers on F-actin Cytoskeleton Levels Incubated in Low Glucose (5 mM) and High Glucose (15 mM) Medium in Single Pancreatic β-Cells of Non-Diabetic (db +/m+) and Diabetic (db +/db +) Mice" --- p.81 / Chapter 4. --- DISCUSSION --- p.100 / Chapter 4.1. --- General Discussion --- p.100 / Chapter 5. --- SUMMARY --- p.120 / Chapter 6. --- FUTURE PERSPECTIVES --- p.121 / Chapter 7. --- REFERENCES --- p.123

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

糖尿病是一種以不正常的高血糖為主要特徵的長期性的糖代謝紊亂疾病。二型糖尿病是常見的糖尿病類型，多於九成的糖尿病病人患有此種類型。各種引起糖尿病的病因最終都會導致血糖過高，並且最終會引起有關眼睛，腎臟，神經和血管系統的併發癥。迄今，糖尿病正影響著大約世界6%的人口，而現在患病率依然在逐年增加。在香港，由於高能量的食和缺乏運動，越來越多的老年人和青年人正在遭受著糖尿病的困擾。糖尿病不是一種致命性的疾病，但是如果沒有採取好的治療控制措施，糖尿病最終會引起一些併發癥，這些併發癥最終會使糖尿病患者走向死亡。高血糖癥不僅是糖尿病的主要特徵，而且也是引起各種糖尿病併發癥的重要因素，在二型糖尿病的治療當中，根據各種病理因素，市場上已經研製出了很多西藥來治療糖尿病。然而，它們都有一些副作用的限制。因此，我們需要通過綜合治療和通過新的途徑研製新的製劑來控制血糖水平，保護病人遠離長期併發癥的困擾。如今，腎臟在血糖平衡中的重要角色已經被很好的認知。 在過去的二十年裡， 通過減少血糖在腎臟的重吸收來增加尿液中血糖的排出，從而達到降低體內血糖水平的方法已經被提出并認為是治療糖尿病的一直新的途徑。 在腎臟中，鈉葡萄糖共轉運體2（SGLT 2）主要負責葡萄糖的重吸收，因此，鈉葡萄糖共轉運體2（SGLT 2）抑製劑被認為是一種有潛質的新型的治療糖尿病的製劑。然而，市場上至今沒有成功研製這種製劑。达格列嗪（dapagliflozin），作為一種最有潛質的鈉葡萄糖共轉運體2（SGLT 2）抑製劑，依然處於臨床三期實驗。至今，對具有鈉葡萄糖共轉運體2（SGLT 2）抑製作用的天然產物和傳統中醫藥的信息報導非常少。中醫中藥的治療理念強調整體治療，從此點看來，爲了使糖尿病患者遠離長期的糖尿病併發癥的困擾，中醫中藥可能比西藥更有優勢。 / 因此，本研究的目的是尋找那些具有體外能專門抑制鈉葡萄糖共轉運體2（SGLT 2）並且體內能通過增加尿糖排出來降低血糖水平的抗糖尿天然產物或傳統中藥。從文獻分析中找到了經常用於治療糖尿病的11種中藥和兩種天然產物。 / 試管實驗確立了五味子醇提物和丹皮酚對表達了人的鈉葡萄糖共轉運體2（SGLT 2）基因的COS 7細胞鏈中鈉葡萄糖共轉運體2對¹⁴C-α-甲基- D-葡萄糖苷的吸收作用具有很強的抑制作用。 / 生物活性引導的片段分析確立了五味子醇提物中的活性片段--乙酸乙酯：甲醇（4:6）（F8）片段具有明顯的專門抑制鈉葡萄糖共轉運體2的作用。本實驗也對F8進行了高效液相色譜和液質聯用色譜分析。五味子中三種常見的化合物：五味子甲素，五味子乙素和五味子醇甲存在于F8中，但濃度都很低。試管實驗顯示，這三種常見化合物均無抑制鈉葡萄糖共轉運體2的作用。因此得出結論，這三種常見的五味子化合物不是F8中有效的抑制鈉葡萄糖共轉運體2的活性成份。 / 本實驗也利用動物實驗調查了丹皮酚的抗糖尿作用。糖尿病大鼠被餵食了三個星期的丹皮酚，基礎血糖實驗和尿糖排出實驗均無陽性結果。 / Diabetes Mellitus (DM) is a chronic disorder of glucose metabolism characterized by abnormally high blood glucose level. Type 2 DM is the common form of diabetes which accounts for more than 90% of all DM cases. All causes of diabetes ultimately lead to hyperglycemia, and it can cause the late complications involving the eyes, kidneys, nerves and blood vessels, which are harmful to health. DM is now affecting about 6% population of the world, and the prevalence is still increasing quickly year by year. In Hong Kong, more and more elderly and youth are suffering from diabetes because of lacking of exercise and high energy diet. DM is not a fatal disease, but if no good action is taken, it can finally cause some kinds of complications, which can lead the patients to the end of their lives. Hyperglycemia is the major characteristics of diabetes, and it is also an important factor which induces all kinds of diabetic complications. In the therapy of type 2 diabetes, a lot of western medicine have been developed in the market according to various pathological causes. However, they have limitations such as existence of side effects. Therefore, combination therapy and development of new agents with novel mechanisms should be required to control the glycemic level and protect the patients from the long-term complications. Nowadays, the significance of the kidney's role in glucose homeostasis is well recognized. Glucose excretion with urine by reducing the renal glucose reabsorption to attenuate the glycemic level has been considered as a new mechanism to treat diabetes since the past two decades. Inhibitors on sodium glucose co-transporters 2 (SGLT 2) which are responsible for the glucose reabsorption in kidney are considered as a kind of new agents that have a potential on the treatment of diabetes. However, there is still no such kind of drug developed in the market, since the most potential one, dapagliflozin, is still on Phase III clinical trial. So far, only few information is found on natural products/traditional Chinese medicines (TCMs) that possess SGLT inhibitory action. Regarding the protection of patients from long-term complications, Chinese medicine which consider the body as a whole, may have advantages over western drugs. / Therefore, the aim of this study is to search for anti-diabetic TCM/natural products which specifically inhibit the activity of SGLT2 in vitro and attenuate plasma glucose level in vivo via increasing glucose excretion through urination. From literature review, 11 TCMs and 2 natural products frequently used in treating DM were selected for screening. / Using hSGLT 1 and hSGLT 2-expressed COS-7 cell lines as a model, in vitro study demonstrated that Fructus Schisandrae chinensis (ethanolic extract) and paeonol posses the most potent inhibitory effect on SGLT 2 in the in vitro ¹⁴C-α-methyl-D-glucopyranoside (¹⁴C-AMG) uptake assay. / The purification of active fraction(s) in ethanolic extract of Schisandrae chinensis fructus was carried out using the bioassay-guided fractionation assay. The ethyl acetate-methanol (4:6) fraction (F8) was selected with significant specific inhibitory effect on SGLT 2. UPLC and LC/MS-MS profiles of F8 were also given in this study. The concentrations of three common compounds of Fructus Shisansrae chinensis: deoxyschisandrin, schisandrin B (γ-schisandrin) and schisandrin were shown very low concentration in F8, the results of uptake assay showed none of these three compounds have inhibitory effects on SGLT 2. It is concluded that these three common compounds in Schisandrae chinensis fructus are not the effective ingredients in F8 which can specifically inhibit SGLT 2. / The anti-diabetic effects of paeonol in treating type 2 DM was investigated in animal study. Paeonol (200 and 300 mg/mL) was given to the type 2 diabetic rat model - Zucker Diabetic Fatty (ZDF) rats for three weeks, the results showed no positive effects on the basal glycaemia test and urinary glucose excretion test. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Qu, Yue. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 141-153). / Abstracts also in Chinese. / TABLE OF CONTENTS / ABSTRACT --- p.iv / 摘要 --- p.vii / ACKNOWLEDGEMENT --- p.ix / LIST OF ABBREVIATIONS --- p.x / LIST OF TABLES --- p.xiii / LIST OF FIGURES --- p.xiv / TABLE OF CONTENTS --- p.1 / Chapter CHAPTER 1 --- INTRODUCTION --- p.8 / Chapter 1.1 --- Definition, diagnosis, classification and epidemiology of Diabetes Mellitus --- p.8 / Chapter 1.1.1 --- Definition of Diabetes Mellitus --- p.8 / Chapter 1.1.2 --- Diagnosis of Diabetes Mellitus --- p.8 / Chapter 1.1.3 --- Classification of Diabetes Mellitus --- p.9 / Chapter 1.1.4 --- Prevalence of Diabetes Mellitus --- p.11 / Chapter 1.2 --- Glucose Homeostasis and Diabetes Mellitus --- p.12 / Chapter 1.2.1 --- General Description --- p.12 / Chapter 1.2.2 --- Kidney's role in Glucose Homeostasis --- p.14 / Chapter 1.2.2.1 --- Gluconeogenesis in the Kidney --- p.15 / Chapter 1.2.2.2 --- Glucose Reabsorption in the Kidney --- p.15 / Chapter 1.2.2.3 --- Renal glucose transporters --- p.17 / Chapter 1.2.2.4 --- Disorders with abnormal renal glucose transport --- p.19 / Chapter 1.3 --- Etiology of Diabetes Mellitus --- p.20 / Chapter 1.3.1 --- Pancreatic β cell dysfunction --- p.21 / Chapter 1.3.2 --- Insulin resistance --- p.21 / Chapter 1.4 --- Diabetic complications --- p.23 / Chapter 1.5 --- Treatment of type 2 Diabetes Mellitus --- p.25 / Chapter 1.5.1 --- Conventional therapy of type 2 Diabetes Mellitus --- p.25 / Chapter 1.5.2 --- New mechanism for the treatment of type 2 Diabetes Mellitus - Inhibition of glucose reabsorption by glucose transporters in Kidney --- p.29 / Chapter 1.6 --- Traditional Chinese Medicine for Diabetes Mellitus --- p.30 / Chapter 1.7 --- Project objective --- p.33 / Chapter CHAPTER 2 --- TRADITIONAL CHINESE HERBAL MATERIALS AND NATURAL PRODUCTS --- p.36 / Chapter 2.1 --- Materials --- p.36 / Chapter 2.2 --- General description and anti-diabetic effects of selected herbs/natural products --- p.38 / Chapter 2.3 --- Extraction Method --- p.45 / Chapter CHAPTER 3 --- IN VITRO STUDIES OF THE INHIBITORY EFFECT OF SELECTED TRADITIONAL CHINESE HERBS AND NATURAL PRODUCTS ON SODIUM GLUCOSE COTRANSPORTERS (SGLT) --- p.48 / Chapter 3.1 --- Introduction --- p.48 / Chapter 3.2 --- Materials --- p.49 / Chapter 3.3 --- Methods and Methods --- p.52 / Chapter 3.3.1 --- In vitro model for screening of SGLT inhibitor --- p.52 / Chapter 3.3.1.1 --- Preparation of hSGLT1 and hSGLT2 Plasmid --- p.52 / Chapter 3.3.1.2 --- Transient Transfection of SGLT1 or SGLT2 clone --- p.53 / Chapter 3.3.1.3 --- Detection of mRNA expression level by Reverse Transcription-Polymerase Chain Reaction (RT-PCR) --- p.54 / Chapter 3.3.1.4 --- Development of SGLT1 or SGLT2 stable cell lines --- p.56 / Chapter 3.3.1.5 --- Results --- p.56 / Chapter 3.3.2 --- Cell proliferation assay (MTT assay) --- p.57 / Chapter 3.3.2.1 --- Methods --- p.57 / Chapter 3.3.2.2 --- Results --- p.58 / Chapter 3.3.3 --- Uptake Assay of ¹⁴C-α-methyl-D-glucopyranoside (¹⁴C-AMG) in cultured COS-7 cells expressing SGLT1 or SGLT2 --- p.63 / Chapter 3.3.3.1 --- Methods --- p.63 / Chapter 3.3.3.2 --- Screening Results of Effective Chinese Herbs/Natural Products --- p.64 / Chapter 3.4 --- Discussion --- p.83 / Chapter CHAPTER 4 --- FRACTIONATION OF SCHISANDRAE CHINENSIS FRUCTUS --- p.86 / Chapter 4.1 --- Introduction --- p.86 / Chapter 4.2 --- Organic Extraction of Schisandrae Chinensis Fructus --- p.86 / Chapter 4.2.1 --- Material and Methods --- p.86 / Chapter 4.2.2 --- Result --- p.86 / Chapter 4.3 --- Bioassay-guided Fractionation of Ethanolic Extract of Schisandrae Chinensis Fructus --- p.87 / Chapter 4.3.1 --- Materials --- p.87 / Chapter 4.3.2 --- Methods --- p.87 / Chapter 4.3.2 --- Results --- p.89 / Chapter 4.4 --- ¹⁴C-α-methyl-D-glucopyranoside (¹⁴C-AMG) Uptake Assay of fractions in cultured COS-7 cells expressing SGLT1 or SGLT2 --- p.92 / Chapter 4.4.1 --- Methods --- p.92 / Chapter 4.4.2 --- Results --- p.93 / Chapter 4.5 --- Characterization of F8 of Schisandrae chinensis fructus using Ultra Performance Liquid Chromatography (UPLC) --- p.98 / Chapter 4.5.1 --- Introduction --- p.98 / Chapter 4.5.2 --- Materials and Methods --- p.98 / Chapter 4.5.3 --- UPLC chromatograms --- p.99 / Chapter 4.6 --- Characterization of F8 using Liquid Chromatography/Mass Spectrometry-Mass Spectrometry (LC/MS-MS) --- p.101 / Chapter 4.6.1. --- Materials --- p.101 / Chapter 4.6.2 --- Methods --- p.102 / Chapter 4.6.3 --- Results --- p.103 / Chapter 4.7 --- ¹⁴C-α-methyl-D-glucopyranoside (¹⁴C-AMG) Uptake Assay of three chemical standards in cultured COS-7 cells expressing SGLT1 or SLGT2 --- p.108 / Chapter 4.7.1 --- Methods --- p.108 / Chapter 4.7.2 --- Results --- p.108 / Chapter 4.8 --- Discussion --- p.111 / Chapter CHAPTER 5 --- IN VIVO STUDIES OF THE ANTI-DIABETIC EFFECT OF SELECTED TRADITIONAL CHINESE HERBS AND NATURAL PRODUCTS IN TYPE 2 DIABETIC RAT MODEL --- p.114 / Chapter 5.1 --- Introduction --- p.114 / Chapter 5.1.1 --- Diabetic Animal Models --- p.114 / Chapter 5.2 --- In vivo Study Tests --- p.117 / Chapter 5.2.1 --- Introduction --- p.117 / Chapter 5.2.2 --- Animals --- p.117 / Chapter 5.2.3 --- Methods --- p.118 / Chapter 5.2.4 --- Results --- p.120 / Chapter 5.3 --- Discussion --- p.125 / Chapter CHAPTER 6 --- GENERAL DISCUSSION --- p.128 / Chapter 6.1 --- Importance of SGLT --- p.128 / Chapter 6.2 --- Current developed SGLT 2 Inhibitors --- p.130 / Chapter 6.3 --- Importance and Treatment of DM by TCMs --- p.132 / Chapter 6.4 --- Screening and Developing drugs from Traditional Chinese medicinal plants --- p.134 / Chapter 6.5 --- Limitations and Improvements --- p.136 / Chapter 6.6 --- Future Works --- p.137 / Chapter 6.7 --- Conclusions --- p.139 / REFERENCES --- p.141

In the first study, I aimed to compare the angiotensin II type 1 receptor (AT1R) expression levels of the isolated pancreatic islets from normal and mouse model of T2DM. In addition, 4-week-old diabetic mice were orally treated with AT1R antagonist losartan for 8 weeks. It is found that AT1R mRNA was upregulated markedly in diabetic islets and double-immunolabeling confirmed that AT1R was localized to beta-cells. Losartan selectively improved glucose-induced insulin release and (pro)insulin biosynthesis in diabetic islets. Oral losartan treatment delayed the onset of diabetes, and reduced hyperglycemia and glucose intolerance in diabetic mice. These data indicate that AT1R antagonism improves beta-cell function and glucose tolerance in young T2DM mice. / In the second study, I aimed to examine how the upregulated RAS could impair beta-cell function, where oxidative stress is the potential mediator. Meanwhile, T2DM results in oxidative stress-mediated activation of uncoupling protein 2 (UCP2), a negative regulator of islet function. Thus, it was postulated that some of the protective effects of AT1R antagonism might be mediated through interference with this pathway and tested this hypothesis in a mouse model of T2DM. In order to achieve this, losartan was given to 4-week-old diabetic mice for 8 weeks. UCP2-driven oxidative damage and apoptosis were analyzed in isolated islets. Results showed that losartan selectively inhibited oxidative stress via NADPH oxidase downregulation; this in turn suppressed UCP2 expression, thus improving beta-cell insulin secretion while decreasing apoptosis-induced beta-cell mass loss in diabetic mice islets. These data indicate that islet AT1R activation in young diabetic mice can lead to progressive islet beta-cell failure through UCP2-driven oxidative damage and apoptosis. / The mechanisms by which chronic hyperglycemia associated with glucotoxicity causes beta-cell dysfunction and apoptosis remain ambiguous. Voltage-gated outward potassium (Kv) current, which mediates beta-cell membrane potential and limits insulin secretion, could play a role in glucotoxicity. Meanwhile the RAS has been shown to be upregulated by prolonged exposure to high glucose. In the third part of my study, I therefore investigated the effects of prolonged exposure to high glucose and angiotensin II (Ang II) on the expression and activity of Kv channels in mouse pancreatic beta-cell. Dissociated mice beta-cells, incubated in 5.6 mM or 28 mM glucose for 3-5 days, were used for electrophysiological study; while isolated islets cultured for 1-7 days were proceeded for gene/protein expression analysis. Both Kv channel expression and current were markedly increased by prolonged glucose incubation. Simultaneously, Ang II reduced Kv current under normal glucose condition, while high glucose incubation abolished the effect of Ang II. Moreover, the ability of Ang II on Kv current reduction was eliminated by inhibiting AT2R but not AT1R. These data indicated that Ang II reduced Kv current via AT2R, which was abolished by prolonged high glucose incubation. On the other hand, high glucose increased Kv channel expression and current, which might alter the ability of insulin secretion in beta-cell. (Abstract shortened by UMI.) / Chu, Kwan Yi. / Adviser: P. S. Leung. / Source: Dissertation Abstracts International, Volume: 70-06, Section: B, page: 3246. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 163-188). / 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. / Abstracts in English and Chinese. / School code: 1307.

Conclusions. The growing epidemic of type 2 diabetes and its cardiorenal complications place a major burden on our health care system. Diabetic kidney disease is of particular importance in Asian populations including Chinese. In this series of studies, using a large prospective cohort established since 1995, I confirmed the powerful predictive value of albuminuria on cardio-renal complications. Inhibition of the RAAS interacted with both modifiable and genetic factors, notably the ACE I/D polymorphism, on the development of cardio-renal complications. In addition, it was found that CKD predicts CVD independent of albuminuria. Based on two prospective studies, I confirmed the effectiveness of global risk-factor control using structured care protocol to prevent these devastating complications. (Abstract shortened by UMI.) / I then examined the possible independent and interactive effects of CKD and albuminuria on cardio-renal outcomes in the original cohort of 5,004 patients. Glomerular filtration rate was estimated (eGFR) by the Modification of Diet in Renal Disease equation. The frequency of CKD as defined by eGFR <60ml/min/1.73m 2 was 15.8% in the cohort at baseline, when 6% of patients had serum creatinine ≥150mumol/L. / In collaboration with colleagues, I have conducted a series of studies to examine the prognostic factors for cardio-renal complications in Chinese type 2 diabetic patients. The modulating effects of RAAS inhibition and the effectiveness of rnuitidisciplinary care to prevent ESRD are also examined. / Research Hypotheses. (1) Albuminuria is a prognostic factor on cardio-renal outcomes in type 2 diabetes patients; (2) Chronic Kidney Disease is associated with other metabolic risk factors and phenotypes and is a prognostic factor on cardio-renal outcomes in type 2 diabetes patients; (3) Angiotensin-converting-enzyme insertion/deletion polymorphism is a prognostic factor on cardio-renal outcomes in type 2 diabetes patients, and has an effect on treatment responses with RAAS blockage with ACE inhibitors; (4) Structured care models by risk stratification using various prognostic factors and adherence to care protocol can improve cardio-renal outcome in type 2 diabetes patients. / Results. In a prospective cohort of 5,004 patients, I examined the effect of albuminuria and ACE inhibition on survival and cardio-renal outcomes in 3,773 patients who had been observed for at least 6 months with a mean follow up period of 35.8 months. / Taken together, measurement of serum creatinine alone without GFR estimation may underestimate the frequency of CKD in Chinese type 2 diabetic patients. Estimated GFR was inversely associated wit-29h an increasing frequency of micro- and macrovascular complications cross-sectionally and an increased risk of all-cause mortality prospectively, independent of albuminuria and metabolic control. / So Wing Yee. / Source: Dissertation Abstracts International, Volume: 70-06, Section: B, page: 3422. / Thesis (M.D.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 203-243). / 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. / School code: 1307.

Background. Diabetes mellitus is a complex metabolic disorder characterized by clustering of multiple cardiovascular risk factors. Diabetic albuminuria is associated with increased prevalence of both micro-vascular and macro-vascular complications. This thesis examined vascular function (Flow-mediated dilatation, FMD) in type 2 diabetic patients with particular emphasis on its relationships with nephropathy. Independent predictors for FMD in Chinese population using data from both diabetic and non-diabetic subjects as well as the predictive value of FMD on clinical endpoints and death in type 2 diabetic patients with nephropathy were examined. / Conclusions. In Chinese subjects with or without type 2 diabetes, hyperglycaemia, hypertriglyceridemia, smoking and albuminuria were independent predictors for FMD. Type 2 diabetic subjects with overt nephropathy had impaired endothelium-dependent and endothelium-independent dilatation, suggesting vascular dysfunction beyond the endothelium. In agreement with studies from Caucasians, smoking was the most important determinant for vascular dysfunction in Chinese type 2 diabetic patients with overt nephropathy. Furthermore, FMD was predictive of new onset of cardiovascular events and related death in Chinese type 2 diabetic patients with overt nephropathy. / In diabetic patients with overt nephropathy, smoking (current and ex-smokers), waist hip ratio (WHR) and serum creatinine were independent predictors for impaired FMD. The latter was predictive of advancement of IMT and was an independent predictor for new onset of combined cardiovascular diseases and related death after a follow up period of 42 months (log rank test=6.04, p=0.014 using Cox regression analysis) after controlling for all confounding factors. In addition, fasting total cholesterol and plasma glucose were predictive for all-cause mortality while serum creatinine predicted new onset of renal endpoint. In a subgroup analysis in diabetic patients with overt nephropathy, smokers who developed CVD or ESRD had greater diminution of FMD than those who did not develop clinical endpoints. / Methods and results. FMD was assessed using high-resolution ultrasound scan. In the cross-sectional study, the sample population was divided into four groups according to the presence or absence of type 2 diabetes and level of albuminuria. They included the non-diabetic group (N=52), diabetic group with normoalbuminuria (N=18), diabetic group with microalbuminuria (N=18) and diabetic group with overt nephropathy defined as macroalbuminuria and renal insufficiency (N=22). Compared to non-diabetic subjects, type 2 diabetic subjects with nephropathy had impaired FMD (4.54% +/- 2.25 vs. 2.50% +/- 2.31, p<0.05) and impaired GTN-dependent dilatation (GTND) (14.30% +/- 3.77 vs. 12.70% +/- 4.70, p<0.05). They also had reduced endothelium-dependent dilatation to endothelium-independent dilatation ratio when compared to non-diabetic subjects (0.19 +/- 0.17 vs. 0.32 +/- 0.15, p<0.05). These findings suggest that the impaired vascular dilatation was due to dysfunction of both endothelium and vascular smooth muscle cells. In the entire cohort, fasting plasma glucose, fasting triglyceride, smoking and albuminuria were independent predictors for FMD. / Lai Wai Keung Christopher. / "February 2006." / Source: Dissertation Abstracts International, Volume: 67-11, Section: B, page: 6298. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (p. 202-252). / 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. / Abstracts in English and Chinese. / School code: 1307.

Conclusion. The equations developed in this study provide a more accurate estimate of GFR, ranging from normal to renal impairment, in both Chinese diabetic and non-diabetic patients, compared to currently available GFR formulae. / Hypothesis/objectives. Type 2 diabetes mellitus is a major health burden associated with increased morbidity and mortality as well as socio-economic impact. A rapid increase in disease prevalence has been reported and predicted in China and other Asian countries. Patients with low and declining GFR and microalbuminuria are at high CVD risk. A simple and precise predictive equation of GFR for Chinese diabetic patients is essential in the light of the growing epidemic of diabetes and CKD in Chinese population both for monitoring and treatment purposes. In this pilot study, a set of accurate, simple and clinically practical equations to predict GFR in Chinese type 2 diabetic patients was established. Their performance was validated using separate samples of diabetic and non-diabetic subjects and compared with other widely used GFR formulae. / Methods. 202 type 2 diabetic patient and 46 non-diabetic patients were enrolled in the study. Of these 135 were randomly selected as the training sample; the remaining 67 diabetic patients and 46 non-diabetic patients constituted 2 validation groups. The prediction equation was developed by stepwise regression applied to the training sample. The equation was then tested and compared with other prediction equation including MDRD and CG equations in the validation samples. / Results. Independent factors associated with GFR included age, serum creatinine concentration, serum urea nitrogen level and serum albumin levels (P < 0.005 for all factors). Two predictive formulae, sRFCD and RFCD, were established. Simplified Renal formula in Chinese Diabetes (sRFCD) Study (ml/min/1.73 m2) is: GFR (for men) = 90400 x (Age)-0.495 (yr) x [ SCr]-1.097 (mumol/l) GFR (for women) = 58983 x (Age)-0.542 (yr) x [SCr]-1.012 (mumol/l) and Renal formula in Chinese Diabetes (RFCD) Study (ml/min/1.73 m2) is: GFR (for men) = 11825 x (Age)-0.494 x [SCr]-1.059 (mumol/l) x [Alb]+0.485 (g/l) GFR (for women) = 34166 x ( Age)-0.489 x [SCr] -0.877 (mumol/l) x [SUN] -0.150 (mmol/l) The multiple regression model explained 89.9% and 89.4% respectively of the variance in the logarithm of GFR. Compared to other GFR formulae, the sRFCD and RFCD formulae showed less bias and were more precise and accurate in estimating GFR in diabetic patients whereas the sRFCD and MDRD formulae showed better performance in non-diabetic patients. / Leung Tak Kei. / "July 2006." / Adviser: Juliana C. N. Chan. / Source: Dissertation Abstracts International, Volume: 68-08, Section: B, page: 5117. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (p. 161-180). / 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. / Abstracts in English and Chinese. / School code: 1307.

Patients’ perceptions of health care and support is a key determinant in self-efficacy and active participation in the management of chronic conditions. Nurses play a significant role in Diabetes Self-Management Education by providing clients with tools, empowerment and knowledge to self-manage their condition. The purpose of this study was to examine and describe diabetes patients’ perceptions of nurses’ support for self-management in Botswana. The aim was to improve clients’ skills in self-management and to strengthen diabetes health care management. This study was carried out at the Diabetes Clinic of Excellence, in the city of Francistown, the second largest city in Botswana. The study population comprised of Type 2 Diabetes patients registered at the Diabetes Clinic for their follow-up. All were aged 18 years and above. Three hundred and fifty-four (354) patients participated in the study. The study used a non-experimental, descriptive, quantitative design. Probability sampling method was used to recruit diabetes patients from the selected clinic. Data were were collected using a structured, researcher developed, questionnaire mostly in face-to-face interviews, a few participants completed the questionnaire. The Quantitative data analysis included descriptive and inferential statistics using SPSS (Statistical Package for Social Science Software (version 25). Spearman rho was used to determine statistical correlation between patients’ perceptions and their self-management practices. The findings showed that generally, patients’ perceptions of professional support was positive regarding most of the constructs measured. However, there were areas that showed less satisfaction with the support such as foot-care, risk control, and ability to identify signs of low and high blood sugar level and carrying of Identification Band (ID). Perceptions of nurses’ motivational behaviour showed varied responses. Patients’ self-care activities were sub-optimal and showed some variations which tended to correspond with their perceptions of professionals support. The Spearman's correlation results ranged from strong, moderate, and weak positive correlation. A few demographic variables showed some impact on self-care activities. Based on the findings, the study concludes that professional support through DSME and DSMS, self-management and patients’ perceptions of care play a significant role in diabetes management. / Health Studies / M.A. (Nursing Science)

Zhang, Ji. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 100-104). / Abstracts in English and Chinese. / Chapter CHAPTER 1. --- Introduction / Chapter 1.1. --- Introduction of genetic association studies --- p.1 / Chapter 1.1.1. --- Application of genetic association studies in complex diseases --- p.3 / Chapter 1.1.2. --- Application of genetic association studies in type-2 diabetes --- p.4 / Chapter 1.2. --- Study design of genetic association studies --- p.7 / Chapter 1.3. --- Overview of statistical approaches in association studies --- p.10 / Chapter 1.3.1. --- Preliminary analyses --- p.10 / Chapter 1.3.1.1. --- HardýؤWeinberg equilibrium testing --- p.10 / Chapter 1.3.1.2. --- Inference of missing genotype data --- p.12 / Chapter 1.3.1.3. --- SNP tagging --- p.14 / Chapter 1.3.2. --- Single-point and multipoint tests for association --- p.15 / Chapter 1.4. --- Other relevant methods employed in this study --- p.20 / Chapter 1.4.1. --- Self-Organizing Maps (SOM) with further classification by K-means clustering --- p.20 / Chapter 1.4.2. --- Random forests --- p.27 / Chapter 1.5. --- Main objectives of this study --- p.31 / Chapter CHAPTER 2. --- Materials and methods / Chapter 2.1. --- Study cohort --- p.32 / Chapter 2.2. --- Study design --- p.34 / Chapter 2.2.1. --- Construction of sample sets for each stage using SOM and K-means clustering --- p.34 / Chapter 2.2.2. --- Stage 1 analysis by random forests --- p.37 / Chapter 2.2.3. --- Stage 2 analysis by chi-square test --- p.42 / Chapter 2.2.4. --- Two-stage genetic association study by chi-square test --- p.43 / Chapter 2.2.5. --- Comparison of results: random forests plus chi-square test versus chi-square test --- p.43 / Chapter 2.2.6. --- Validation of results in the whole sample set by allelic chi-square test --- p.44 / Chapter 2.2.7. --- Extensions of the study: cumulative effects of candidate SNPs on risk of type-2 diabetes --- p.45 / Chapter CHAPTER 3. --- Results / Chapter 3.1. --- Effects of sample classification by SOM and K-means clustering --- p.50 / Chapter 3.2. --- Genetic associations in stage 1 --- p.64 / Chapter 3.3. --- Genetic associations in stage 2 and validation of results --- p.69 / Chapter 3.4. --- Cumulative effects of candidate SNPs on risk of type-2 diabetes --- p.76 / Chapter CHAPTER 4. --- Discussion / Chapter 4.1. --- Overall strategy --- p.81 / Chapter 4.1.1. --- Effects of SOM and K-means clustering --- p.82 / Chapter 4.1.2. --- Effects of random forests in the first stage of association study --- p.83 / Chapter 4.1.3. --- Comparison of our method with traditional chi-square test --- p.84 / Chapter 4.1.4. --- Joint effects of candidate SNPs selected by the hybrid method --- p.86 / Chapter 4.2. --- Biological significance of candidate SNPs --- p.88 / Chapter 4.2.1. --- Gene CDKAL1 --- p.89 / Chapter 4.2.2. --- Gene KIAA1305 --- p.90 / Chapter 4.2.3. --- Gene DACH1 --- p.91 / Chapter 4.2.4. --- Gene FUCA1 --- p.92 / Chapter 4.2.5. --- Gene KCNQ1 --- p.93 / Chapter 4.2.6. --- Gene SLC27A1 --- p.94 / Chapter 4.3. --- Limits and improvement of this study --- p.96 / Chapter 4.4. --- Conclusion --- p.99 / REFERENCES --- p.100

Lui, Ming Yin. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 117-129). / Abstracts in English and Chinese. / Acknowledgement --- p.I / Abstract --- p.III / Abstract in Chinese --- p.V / List of Abbreviations --- p.VII / List of Figures --- p.X / List of Tables --- p.XII / Table of Contents --- p.XIII / Chapter Chapter 1: --- Introduction / Chapter 1.1 --- Overview on type 2 diabetes --- p.1 / Chapter 1.1.1 --- Definition of diabetes --- p.1 / Chapter 1.1.2 --- Diagnostic criteria --- p.2 / Chapter 1.1.3 --- Prevalence and societal impact --- p.2 / Chapter 1.1.4 --- Risks factors for type 2 diabetes --- p.4 / Chapter 1.1.4.1 --- Metabolic syndrome --- p.4 / Chapter 1.1.4.2 --- Genetics of type 2 diabetes --- p.6 / Chapter 1.1.4.3 --- "Environmental risk factors, lifestyle and energy imbalance" --- p.8 / Chapter 1.1.5 --- Pathophysiology of type 2 diabetes --- p.9 / Chapter 1.1.5.1 --- Insulin secretion and signaling --- p.9 / Chapter 1.1.5.1.1 --- Insulin Secretion --- p.9 / Chapter 1.1.5.1.2 --- Insulin signaling --- p.11 / Chapter 1.1.5.2 --- Natural history of type 2 diabetes --- p.12 / Chapter 1.1.5.3 --- Insulin resistance --- p.13 / Chapter 1.1.5.4 --- Impairment in insulin secretion --- p.15 / Chapter 1.1.5.5 --- Endocannabinoid system: A new target for energy balance and metabolism --- p.16 / Chapter 1.1.5.6 --- Effects of diabetes mellitus and its complications --- p.16 / Chapter 1.2 --- Biology of prostacyclin synthase (PTGIS) --- p.18 / Chapter 1.2.1 --- Molecular information of PTGIS --- p.18 / Chapter 1.2.2 --- Transcriptional control of PTGIS --- p.19 / Chapter 1.2.3 --- Protein structure of PGIS --- p.21 / Chapter 1.2.4 --- Sub-cellular localization and tissue distribution --- p.22 / Chapter 1.2.5 --- Function of PGIS --- p.25 / Chapter 1.2.5.1 --- Function of PGI2 in blood vessels --- p.26 / Chapter 1.2.5.2 --- Role of PGh in embryo development --- p.26 / Chapter 1.2.5.3 --- Role of PGI2 in apoptosis --- p.27 / Chapter 1.2.5.4 --- Targeted knock-out mice phenotype --- p.27 / Chapter 1.2.6 --- Relationship between PTGIS and diseases --- p.28 / Chapter 1.2.6.1 --- Genetic association --- p.28 / Chapter 1.2.6.2 --- Inactivation and tyrosine nitration of PGIS by peroxynitrite --- p.29 / Chapter 1.3 --- Biology of peroxisome proliferator-activated receptor delta (PPARD) --- p.30 / Chapter 1.3.1 --- Molecular information of PPARD --- p.30 / Chapter 1.3.2 --- Transcriptional control of PPARD --- p.31 / Chapter 1.3.3 --- Translational control and protein structure --- p.32 / Chapter 1.3.4 --- Sub-cellular localization and tissue expression --- p.35 / Chapter 1.3.5 --- Function of PPARδ --- p.37 / Chapter 1.3.5.1 --- Mechanisms of action --- p.37 / Chapter 1.3.5.2 --- Ligands for PPARδ --- p.38 / Chapter 1.3.5.3 --- PPARδ in lipoprotein metabolism --- p.39 / Chapter 1.3.5.4 --- PPARδ action in adipose tissue --- p.39 / Chapter 1.3.5.5 --- PPARδ action in skeletal and cardiac muscle --- p.40 / Chapter 1.3.5.6 --- PPARδ action in liver --- p.42 / Chapter 1.3.5.7 --- PPARδ and endocannabinoid system --- p.42 / Chapter 1.3.5.8 --- PPARδ action in inflammation --- p.43 / Chapter 1.3.5.9 --- Targeted knock-out mice phenotype --- p.44 / Chapter 1.3.5.10 --- Disease association --- p.44 / Chapter 1.4 --- Functional relationship of PGIS and PPARδ: possible role in energy metabolism --- p.46 / Chapter 1.5 --- Methods for studying genetics of type 2 diabetes and linkage analysis results --- p.47 / Chapter 1.5.1 --- Genome-wide scan --- p.47 / Chapter 1.5.2 --- Candidate gene approach --- p.48 / Chapter 1.6 --- Hypothesis and objectives --- p.49 / Chapter 1.7 --- Long-term significance --- p.49 / Chapter Chapter 2: --- Association Study of Prostacyclin Synthase and Peroxisome Proliferator-Activated Receptor Delta Gene Polymorphisms with Type2 Diabetes and Related Metabolic Traits / Chapter 2.1 --- Introduction and research design --- p.50 / Chapter 2.2 --- Study population --- p.52 / Chapter 2.2.1 --- Ethics approval --- p.52 / Chapter 2.2.2 --- Subjects --- p.52 / Chapter 2.2.3 --- Clinical assessments --- p.52 / Chapter 2.3 --- Materials and methods --- p.55 / Chapter 2.3.1 --- DNA samples --- p.55 / Chapter 2.3.2 --- Marker selection --- p.55 / Chapter 2.3.3 --- Genotyping --- p.57 / Chapter 2.3.4 --- Statistical analysis --- p.59 / Chapter 2.4 --- Results and Discussion --- p.60 / Chapter 2.4.1 --- Clinical characteristics of the study population --- p.60 / Chapter 2.4.2 --- Genotyping and LD analysis --- p.60 / Chapter 2.4.3 --- Association with type 2 diabetes and related metabolic traits --- p.61 / Chapter 2.4.3.1 --- Single SNP association with type 2 diabetes --- p.61 / Chapter 2.4.3.2 --- Single SNP association with metabolic traits --- p.64 / Chapter 2.4.3.3 --- Gene-gene interaction on type 2 diabetes --- p.74 / Chapter 2.4.3.4 --- Gene-gene interaction on metabolic traits --- p.74 / Chapter 2.5 --- Limitation and improvement --- p.79 / Chapter 2.6 --- Conclusions --- p.79 / Chapter Chapter 3: --- Functional Studies of Prostacyclin Synthase rs508757-A/G Intronic Polymorphism / Chapter 3.1 --- Introduction and research design --- p.80 / Chapter 3.2 --- Materials and methods --- p.81 / Chapter 3.2.1 --- Bioinformatics --- p.81 / Chapter 3.2.1.1 --- Cross-species alignment --- p.81 / Chapter 3.2.1.2 --- BLAST search and open reading frame prediction --- p.81 / Chapter 3.2.1.3 --- Transcription factor binding sites prediction --- p.82 / Chapter 3.2.2 --- PCR amplification from cDNA --- p.82 / Chapter 3.2.3 --- Culture of mammalian cell --- p.83 / Chapter 3.2.3.1 --- Cell line --- p.83 / Chapter 3.2.3.2 --- Medium and supplement --- p.83 / Chapter 3.2.3.3 --- Cell culture wares --- p.83 / Chapter 3.2.3.4 --- Cell culture conditions --- p.84 / Chapter 3.2.4 --- Construction of reporter vectors with rs508757 flanking sequence --- p.84 / Chapter 3.2.4.1 --- Cloning and vector preparation --- p.84 / Chapter 3.2.4.2 --- Site-directed mutagenesis --- p.84 / Chapter 3.2.5 --- Dual-luciferase reporter assay --- p.85 / Chapter 3.2.5.1 --- Transfection of VSMC --- p.85 / Chapter 3.2.5.2 --- Cell lysis and luminescence measurement --- p.86 / Chapter 3.2.6 --- Circular Dichroism --- p.87 / Chapter 3.2.6.1 --- Introduction to DNA quardruplex structure and circular dichroism --- p.87 / Chapter 3.2.6.1.1 --- DNA quardruplex --- p.87 / Chapter 3.2.6.1.2 --- Circular dichroism --- p.88 / Chapter 3.2.6.2 --- Circular dichroism measurement --- p.89 / Chapter 3.2.6.2.1 --- DNA samples --- p.89 / Chapter 3.2.6.2.2 --- CD spectroscopy --- p.89 / Chapter 3.2.7 --- Statistical analysis --- p.90 / Chapter 3.3 --- Results and Discussion --- p.91 / Chapter 3.3.1 --- Cross-species alignment --- p.91 / Chapter 3.3.2 --- BLAST search and ORF prediction --- p.92 / Chapter 3.3.3 --- PCR results on testing the presence of a new transcript --- p.93 / Chapter 3.3.4 --- Effect of rs508757 flanking sequence on SV40 promoter activity --- p.94 / Chapter 3.3.5 --- Circular dichroism experiment on rs508757 flanking sequence --- p.96 / Chapter 3.3.6 --- DNA slipping model --- p.98 / Chapter 3.3.7 --- Transcription factor binding site prediction --- p.99 / Chapter 3.4 --- Limitation and improvement --- p.107 / Chapter 3.5 --- Conclusions --- p.107 / Chapter Chapter 4: --- "General Discussion, Conclusion and Future Perspectives" / Chapter 4.1 --- General discussion --- p.108 / Chapter 4.2 --- Future perspectives --- p.115 / Chapter 4.2.1 --- "Association on type 2 diabetes and molecular interaction between transcription factors, PTGIS and PPARD" --- p.115 / Chapter 4.2.2 --- Association with diabetic nephropathy --- p.115 / Chapter 4.2.3 --- Study tissue or cell type specific actions of PGIS and PPARδ --- p.116 / Chapter 4.3 --- Conclusions to my project --- p.116 / Chapter Chapter 5: --- Bibliography --- p.117 / Appendix --- p.130