2 型糖尿病(T2D)的發展歷史悠久，但導致T2D 患者胰島素抵抗的確切病理還沒有完全理解。骨骼肌佔大多數(70-80%)的胰島素引導的葡萄糖的吸收，所以它一直是胰島素抵抗的研究焦點。許多 T2D 患者的骨骼組織顯示線粒體功能障礙，但線粒體功能障礙和胰島素抵抗之間的關係尚不清楚還在辯論中。在這個項目中，這種關係是通過研究游離脂肪酸(FFA)( 24 小時處理)對 C2C12 小鼠骨骼肌細胞的效果來闡明。 / 免疫印記法顯示FFA 誘導胰島素抵抗，結合二維電泳和質譜分析的蛋白質組學研究發現FFA 有抑制糖酵解，增加β-氧化作用，沒有改變檸檬酸循環和抑製氧化磷酸化的作用。FFA 抑制電子傳遞鏈的幾個組成部分，揭示線粒體功能障礙，背後的原因可推測為FFA 增加令β-氧化作用增加，但沒有協調改變率檸檬酸循環，導致積累不完全β-氧化的中轉體，導致線粒體過載，最終導致胰島素抵抗。 / There is a long history of Type 2 diabetes (T2D) research development, but the exact pathology leading to insulin resistance of T2D is still not fully understood. T2D is frequently characterized by tissue insulin resistance and it is often associated with an elevated concentration of palmitic acid (PA, a major kind of dietary fatty acid) in serum. Due to this correlation, much of the effort in the field had been concentrated on the effect of PA in insulin action and glucose metabolism, and how elevated PA could possibly cause insulin resistance in specific tissues. / Skeletal muscle accounts for the majority (70-80%) of insulin-mediated glucose uptake, so it has been the focus of insulin resistance studies. Many T2D patients having elevated serum free fatty acid (FFA, where PA is a kind of FFA) also show mitochondrial dysfunction in their skeletal tissue, but the relationship between mitochondrial dysfunction and insulin resistance in skeletal muscle remains unclear and under debate. In this project, the three-party relationship was elucidated by studying the effect of 24hrs of incubation of palmitic acid (PA) on skeletal muscle using C2C12 mouse skeletal cells as model. / PA-treated C2C12 cells show reduction in insulin-stimulated Akt phosphorylation when compared with untreated C2C12 cells. Comparative proteomic study for both total proteins and mitochondrial proteins with 2D gel electrophoresis and mass spectrometry unveil, when compared with untreated cells, PA-treated C2C12 cells show down-regulation in enzymes involved in glycolysis(e.g. glyceraldehyde-3-phosphate dehydrogenase, phosphoglycerate kinase, fructose-bisphosphate aldose A), up-regulation in enzymes involved in beta-oxidation(e.g. 3-ketoacyl-CoA thiolase, 3-hydroxyacyl-CoA dehydrogenase), and down-regulation in proteins involved in oxidative phosphorylation(e.g. ATP synthase subunits, NADH-ubiquinone oxidoreductase 75kDa subunit, cytochrome b-c complex subunit 1). / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Lam, Chor Kwan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 69-78). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts also in Chinese. / Thesis/Assessment Committee --- p.i / Declaration --- p.ii / Abstract (in English) --- p.iii / Abstract (in Chinese) --- p.v / Acknowledgments --- p.vi / Table of Contents --- p.vii / List of Abbreviations --- p.x / List of Figures --- p.xiii / List of Tables --- p.xiv / Chapter 1. --- Literature review --- p.1 / Chapter 1.1. --- Introduction to diabetes mellitus --- p.1 / Chapter 1.1.1. --- Definition and prevalence --- p.1 / Chapter 1.1.2. --- Diagnosis and classification --- p.2 / Chapter 1.1.3. --- Symptoms and complications --- p.4 / Chapter 1.1.4. --- Causes and risk factors --- p.5 / Chapter 1.1.5. --- Prevention and treatment --- p.6 / Chapter 1.2. --- The role of muscle tissue in pathophysiology of T2DM --- p.7 / Chapter 1.3. --- Insulin receptor substrate-1 and Fatty acids-induced insulin resistance --- p.15 / Chapter 1.4. --- Introduction of proteomics --- p.18 / Chapter 1.4.1. --- The application of proteomics in disease discovery --- p.18 / Chapter 1.4.2. --- Application of Proteomics --- p.19 / Chapter 1.4.3 --- Two-dimensional gel electrophoresis --- p.20 / Chapter 1.4.4 --- Organelles proteomics --- p.21 / Chapter 1.4.5. --- Mass spectrometry --- p.22 / Chapter 1.4.6 --- Application of proteomic technology in disease pathology --- p.24 / Chapter 1.4.7 --- Current challenges --- p.25 / Chapter 1.5 --- Objectives --- p.27 / Chapter 2 --- Materials and Methods --- p.28 / Chapter 2.1 --- Fatty acid preparation --- p.28 / Chapter 2.2 --- Cell culture --- p.28 / Chapter 2.2.1 --- Treatment of C2C12 myotubes with Palmitic acid --- p.28 / Chapter 2.2.2 --- MTT assay for viability measurement --- p.29 / Chapter 2.2.3 --- Determination of the IC₅₀ values --- p.31 / Chapter 2.3 --- Proteomic analysis of C2C12 cells with and without PA treatment --- p.32 / Chapter 2.3.1 --- Protein sample preparation from C2C12 skeletal muscle cells --- p.32 / Chapter 2.3.2 --- Protein quantitation --- p.33 / Chapter 2.3.3 --- 2D Gel electrophoresis --- p.34 / Chapter 2.3.4 --- Image analysis --- p.36 / Chapter 2.3.5 --- In gel digestion and MALDI-ToF MS --- p.37 / Chapter 2.4 --- Mitochondrial purification and protein extraction --- p.38 / Chapter 2.4.1 --- Ultracentrifugation method --- p.38 / Chapter 2.4.2 --- Mitochondrial Isolation Kit --- p.39 / Chapter 2.5 --- Western Immunoblotting --- p.40 / Chapter 2.5.1 --- Protein sample preparation --- p.40 / Chapter 2.5.2 --- SDS-PAGE --- p.40 / Chapter 2.5.3 --- Western blotting --- p.40 / Chapter 2.5.4 --- Membrane Blocking and Antibody Incubations --- p.41 / Chapter 2.5.5 --- Detection of Proteins --- p.42 / Chapter 3 --- Results --- p.43 / Chapter 3.1 --- Differentiation of C2C12 myoblast into myotubes --- p.43 / Chapter 3.2 --- The effect of Palmitic acid on C2C12 Proliferation --- p.44 / Chapter 3.3 --- Comparison of total protein profiles of palmitic acid-treated C2C12 myotubes with control myotubes --- p.45 / Chapter 3.4 --- Western blotting of Akt and Phospho-Akt in C2C12 cells treated with Palmitic acid after acute exposure to insulin --- p.50 / Chapter 3.5 --- Comparison of two mitochondria isolation methodsultracentrifugation and mitochondrial isolation kit --- p.51 / Chapter 3.5.1 --- Quantity of extracted mitochondrial protein --- p.51 / Chapter 3.5.2 --- Purity of extracted mitochondrial protein --- p.52 / Chapter 3.6 --- Comparison of mitochondrial protein profiles between palmitic acid-treated and control C2C12 myotubes --- p.53 / Chapter 3.7 --- Western blotting of insulin receptor substrate-1 and its serine phosphorylation --- p.58 / Chapter 4 --- Discussion --- p.59 / Chapter 4.1 --- Investigation of anti-proliferating effect of Palmitic acid on C2C12 using MTT assay --- p.59 / Chapter 4.2 --- Comparison of total protein profiles of palmitic C2C12 myotubes with control myotubes --- p.60 / Chapter 4.3 --- Western blotting of insulin receptor substrate-1and its serine phosphorylation --- p.62 / Chapter 4.4 --- Western blotting of Akt and Phospho-Akt in C2C12 cells treated with Palmitic acid after acute exposure to insulin --- p.63 / Chapter 4.5 --- Comparison of mitochondrial protein profiles between palmitic acid-treated and control C2C12 myotubes --- p.65 / Chapter 4.6 --- Problems faced and future prospect --- p.68 / Chapter 5 --- References --- p.69
| Identifer | oai:union.ndltd.org:cuhk.edu.hk/oai:cuhk-dr:cuhk_328278 |
| Date | January 2012 |
| Contributors | Lam, Chor Kwan., Chinese University of Hong Kong Graduate School. Division of Life Sciences. |
| Source Sets | The Chinese University of Hong Kong |
| Language | English, Chinese |
| Detected Language | English |
| Type | Text, bibliography |
| Format | electronic resource, electronic resource, remote, 1 online resource (xiv, 78 leaves) : ill. (some col.) |
| Rights | Use of this resource is governed by the terms and conditions of the Creative Commons “Attribution-NonCommercial-NoDerivatives 4.0 International” License (http://creativecommons.org/licenses/by-nc-nd/4.0/) |
Page generated in 0.0038 seconds