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Yip, Wai Ki. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 203-228). / Abstracts in English and Chinese. / ACKNOWLEDGMENTS --- p.i / ABBREVIATIONS --- p.iii / ABSTRACT --- p.x / 撮要 --- p.xiv / TABLE OF CONTENTS --- p.xvii / Chapter CHAPTER 1: --- GENERAL INTRODUCTION / Chapter 1.1 --- Hematopoiesis and Leukemia / Chapter 1.1.1 --- An Overview on Hematopoiesis Development --- p.1 / Chapter 1.1.1.1 --- Hematopoietic Growth Factors --- p.4 / Chapter 1.1.1.2 --- Site Switching of Hematopoiesis --- p.5 / Chapter 1.1.2 --- An Overview on Leukemia --- p.7 / Chapter 1.1.2.1 --- Classification of Leukemia --- p.7 / Chapter 1.1.2.2 --- Conventional Therapy of Leukemia --- p.10 / Chapter 1.1.2.3 --- Novel Approaches to Leukemia Therapy: Apoptosis and Differentiation Induction --- p.13 / Chapter 1.2 --- Polysaturated Fatty Acids / Chapter 1.2.1 --- An Overview on Polyunsaturated Fatty Acids --- p.16 / Chapter 1.2.2 --- An Overview on Essential Fatty Acids --- p.17 / Chapter 1.2.2.1 --- Alpha Linolenic Acids (ALA) --- p.17 / Chapter 1.2.2.2 --- Gamma Linolenic Acid (GLA) --- p.18 / Chapter 1.2.3 --- "An Overview on Conjugated Fatty Acids: Conjugated Linoleic Acid (CLA), Conjugated EPA and Conjugated DHA" --- p.20 / Chapter 1.2.4 --- Conjugated Linolenic Acid (CLN) --- p.24 / Chapter 1.2.4.1 --- Identification and Production of CLN --- p.28 / Chapter 1.2.4.2. --- Metabolism of CLN --- p.29 / Chapter 1.2.4.3 --- Anti-Obese and Hypolipidemic Effect of CLN --- p.30 / Chapter 1.2.4.4 --- Anti-Proliferative Effect of CLN --- p.30 / Chapter 1.2.4.5 --- Other Novel Effects of CLN --- p.32 / Chapter 1.3 --- Aims and Scopes of This Investigation --- p.34 / Chapter CHAPTER 2: --- MATERIALS AND METHODS / Chapter 2.1 --- Materials --- p.36 / Chapter 2.1.1 --- Animals --- p.36 / Chapter 2.1.2 --- Human Cell Lines --- p.36 / Chapter 2.1.3 --- "Cell Culture Medium, Buffers and Other Reagents" --- p.38 / Chapter 2.1.4 --- Reagents and Buffer for Flow Cytometry --- p.44 / Chapter 2.1.5 --- Reagents for DNA Extraction --- p.47 / Chapter 2.1.6 --- Cell Death Detection ELISApLus --- p.48 / Chapter 2.1.7 --- Reagents for Measuring Caspase Activity --- p.50 / Chapter 2.1.8 --- Reagents for FACE´ёØ ELISA Kit --- p.53 / Chapter 2.1.9 --- Reagents for Western Blotting --- p.55 / Chapter 2.2 --- Methods --- p.65 / Chapter 2.2.1 --- Culturing the Tumor Cell Lines --- p.65 / Chapter 2.2.2 --- "Isolation, Preparation and Culturing of Murine Peritoneal Macrophages and Bone Marrow Cells" --- p.66 / Chapter 2.2.3 --- Anti-proliferation Assays --- p.67 / Chapter 2.2.4 --- Cell Viability Determination --- p.68 / Chapter 2.2.5 --- Determination of Anti-leukemia Activity In Vivo (In Vivo Tumorigenicity Assay) --- p.69 / Chapter 2.2.6 --- Cell Cycle Analysis by Flow Cytometry --- p.69 / Chapter 2.2.7 --- Detection of Apoptosis --- p.70 / Chapter 2.2.8 --- Assessment of Differentiation-associated Characteristics --- p.74 / Chapter 2.2.9 --- Measurement of Caspase Activities --- p.76 / Chapter 2.2.10 --- Protein Expression Study --- p.78 / Chapter 2.2.11 --- Detection of Phosphorylation of JNK by FACE´ёØ JNK ELISA Kit --- p.83 / Chapter 2.2.12 --- Detection of Phosphorylation of NF-kB by FACE´ёØ NF-kB p65 Profiler --- p.85 / Chapter 2.2.13 --- Statistical Analysis --- p.85 / Chapter CHAPTER 3: --- STUDIES ON THE ANTI PROLIFERATIVE EFFECTS OF CONJUGATED LINOLENIC ACIDS ON THE HUMAN MYELOID LEUKEMIA CELLS / Chapter 3.1 --- Introduction --- p.86 / Chapter 3.2 --- Results / Chapter 3.2.1 --- Anti-proliferative Activity of CLN Isomers on Various Myeloid Leukemia and Lymphoma Cell Lines In Vitro --- p.88 / Chapter 3.2.2 --- Direct Cytotoxic Effect of Jacaric Acid on HL-60 Cells In Vitro --- p.95 / Chapter 3.2.3 --- Cytotoxic Effect of Jacaric Acid on Primary Murine Cells and Human Normal Cell Lines In Vitro --- p.98 / Chapter 3.2.4 --- Kinetics and Reversibility Studies of the Anti-proliferative Effect of Four CLN Isomers on the Human Promyelocytic Leukemia HL-60 Cells --- p.101 / Chapter 3.2.5 --- Synergistic Anti-proliferative Effect of Jacaric Acid with Vitamin D3 and All Trans-Retinoic Acid (ATRA) on the Human Promyelocytic Leukemia HL-60 Cells In Vitro --- p.114 / Chapter 3.2.6 --- Effect of Jacaric Acid on the Cell Cycle Profile of the HL-60 Cells In Vitro --- p.116 / Chapter 3.2.7 --- Effect of Jacaric Acid on the In Vivo Tumorigenicity of the HL-60 Cells --- p.119 / Chapter 3.3 --- Discussion --- p.121 / Chapter CHAPTER 4: --- STUDIES ON THE APOPTOSIS-INDUCING AND DIFFERENTIATION-INDUCING EFFECTS OF CONJUGATED LINOLENIC ACIDS ON THE HUMAN MYELOID LEUKEMIA CELLS / Chapter 4.1.1 --- Introduction --- p.128 / Chapter 4.2 --- Results / Chapter 4.2.1 --- Induction of Apoptosis in the Human Promyelocytic Leukemia HL-60 Cells by Jacaric Acid --- p.134 / Chapter 4.2.2 --- Apoptosis-Inducing Effect of Jacaric Acid on the Human Promyelocytic Leukemia HL-60 Cells as Detected by Annexin V-GFP PI Double Staining Method --- p.138 / Chapter 4.2.3 --- Effect of Jacaric Acid on the Mitochondrial Membrane Potential in the Human Promyelocytic Leukemia HL-60 Cells --- p.140 / Chapter 4.2.4 --- Effects of Jacaric Acid on the Caspase Activities in the Human Promyelocytic Leukemia HL-60 Cells --- p.142 / Chapter 4.2.5 --- Effects of Jacaric Acid and Antioxidants on the ROS Induction in the Human Promyelocyic Leukemia hl-6 Cells --- p.147 / Chapter 4.2.6 --- Effect of N-acetyl-L-Cysteine on the Apoptosis-Inducing Activity of Jacaric Acid in the Human Promyelocytic Leukemia HL-60 Cells --- p.149 / Chapter 4.2.7 --- Morphological Studies on the Jacaric Acid-treated Human Promyelocytic Leukemia HL-60 Cells --- p.151 / Chapter 4.2.8 --- Cell Size and Granularity of the Human Promyelocytic Leukemia HL-60 Cells after Treatment with Different CLN Isomers --- p.153 / Chapter 4.2.9 --- Expression of Differentiation-Related Cell Surface Markers in the Human Promyelocytic Leukemia HL-60 Cells after Treatment with Jacaric Acid --- p.155 / Chapter 4.3 --- Discussion --- p.158 / Chapter CHAPTER 5: --- STUDIES ON THE APOPTOSIS-ASSOCIATED PROTEINS AND SIGNALING PATHWAYS IN CONJUGATED LINOLENIC ACID-INDUCED APOPTOSIS OF THE HUMAN MYELOID LEUKEMIA CELLS / Chapter 5.1 --- Introduction --- p.165 / Chapter 5.2 --- Results / Chapter 5.2.1 --- Expression of Fas and Fas Ligand Proteins in the Jacaric Acid- treated Human Promyelocytic Leukemia HL-60 Cells --- p.171 / Chapter 5.2.2 --- Expression of Bcl-2 Family Member Proteins in the Jacaric Acid- treated Human Promyelocytic Leukemia HL-60 Cells --- p.173 / Chapter 5.2.3 --- Cytochrome c Release in the Jacaric Acid-treated Human Promyelocytic Leukemia HL-60 Cells --- p.175 / Chapter 5.2.4 --- Cleavage of Poly(ADP-ribose) Polymerase (PARP) in the Jacaric Acid-treated Human Promyelocytic Leukemia HL-60 Cells --- p.177 / Chapter 5.2.5 --- Phosphorylation of ERK in the Jacaric Acid-treated Human Promyelocytic Leukemia HL-60 Cells --- p.179 / Chapter 5.2.6 --- Phosphorylation of JNK in the Jacaric Acid-treated Human Promyelocytic Leukemia HL-60 Cells --- p.181 / Chapter 5.2.7 --- Phosphorylation of NF-kB Protein in the Jacaric Acid-treated Human Promyelocytic Leukemia HL-60 Cells --- p.183 / Chapter 5.3 --- Discussion --- p.185 / Chapter CHAPTER 6: --- CONCLUSIONS AND FUTURE PERSPECTIVES --- p.195 / REFERENCES --- p.203

Milk fat composition determines specific rheological, sensory and physicochemical properties of dairy products such as texture, melting point, flavor, color, oxidation rates, and viscosity. Previous studies have shown that milkfats containing higher levels of long chain polyunsaturated fatty acids have lower melting points and decreased solid fat contents which leads to softer-textured products. An increased risk of higher oxidation rates can be a disadvantage of high levels of polyunsaturated fatty acids. Three different milkfat compositions were obtained through dietary manipulation of cows: high oleic content, high linoleic content and control milkfat. Ice cream and butter were processed from the treated and control milks. Butter and ice cream samples then were analyzed to measure differences in fatty acid profiles and firmness. High-oleic and high-linoleic milkfat had lower concentrations of saturated fatty acids, such as C 16:0. Conjugated linoleic acid content was increased in the high-linoleic milkfat. High-oleic milkfat resulted in a softer butter. Ice cream samples were analyzed to measure differences in viscosity, melting point, oxidation rate and sensory perception. Significant differences (P<0.05) were found in the fatty acid profiles of milkfat, ice cream mix viscosity, peroxide values of ice cream after 3 to 5 months of storage, butter color, and butter firmness. Sensory analyses included a scooping test at -18°C to detect differences in texture. A difference test was conducted to determine oxidation flavor differences between the three ice cream treatments at extended storage times. No significant differences were found in the scooping test or the oxidation flavor difference. Manipulation of the cow's diet increased the total amount of unsaturated fatty acids. It also influenced firmness of butter and behavior of peroxide values during extended storage of high-linoleic ice cream. / Master of Science

No / The effects of a conjugated linoleic acid (CLA) mixture of single isomers (50:50, w/w, cis9,trans11:trans10,cis12) and the individual isomers on (a) the production of resting and calcium ionophore stimulated 14C-eicosanoids and (b) the incorporation of 14C-arachidonic acid (AA) into membrane phospholipids of human saphenous vein endothelial cells were investigated. The CLA mixture and the individual isomers were found to inhibit resting production of 14C-prostaglandin F2a by 50, 43 and 40%, respectively. A dose dependent inhibition of stimulated 14C-prostaglandins was observed with the CLA mixture (IC50 100 ¿M). The cis9,trans11 and trans10,cis12 (50 ¿M) isomers individually inhibited the overall production of stimulated 14C-prostaglandins (between 35 and 55% and 23 and 42%, respectively). When tested at a high concentration (100 ¿M), cis9,trans11 was found to inhibit eicosanoid production in contrast to trans10,cis12 that caused stimulation. The overall degree of 14C-AA incorporation into membrane phospholipids of the CLA (mixture and individual isomers) treated cells was found to be lower than that of control cells and the cis9,trans11 isomer was found to increase the incorporation of 14C-AA into phosphatidylcholine. Docosahexaenoic acid, eicosapentaenoic acid and linoleic acid did not alter the overall degree of incorporation of 14C-AA. The results of this study suggest that both isomers inhibit eicosanoid production, and although trans10,cis12 exhibits pro-inflammatory activity at high concentrations, the CLA mixture maintains its beneficial anti-inflammatory action that contributes to its anti-carcinogenic and anti-atherogenic properties.

The high rate of obesity is having a significant impact on human health. Understanding the underlying biological mechanisms that regulate adipogenesis and adipocyte lipid metabolism is necessary to identify novel approaches that promote weight loss. Conjugated linoleic acid (CLA) is an example of a naturally-derived product reported to exhibit an anti-obesity effect. For this thesis, it was hypothesized that the anti-obesity effects of the t10-c12 CLA isomer is due to lipid droplet dynamics alteration through activation of the Wnt/β-catenin pathway, which leads to weight loss via affecting adipogenesis and/or adipocyte death. Testing of this hypothesis was achieved by examining the effects of the most biologically active CLA isomers, cis-9, trans-11 (c9-t11), trans-10, cis-12 (t10-c12) CLA using in vitro (3T3-L1 cell line) and in vivo (mouse) models. In 3T3-L1 preadipocytes, both c9-t11 and t10-c12 CLA stimulated early stage differentiation, while t10-c12 CLA inhibited late differentiation as indicated by fewer lipid droplets, lower adipokine levels, and decreased levels of perilipin-1 and phospho-perilipin-1 compared to null. The t10-c12 CLA isomer decreased hormone-sensitive lipase (HSL) levels and inhibited lipolysis by activating protein kinase Cα (PKCα). As well, t10-c12-CLA inhibited adipocyte differentiation by stabilizing β-catenin, which sequesters peroxisome proliferator-activated receptor-γ in an inactive complex. Reduced body weight in both db/db and C57B/L6 mice fed t10-c12 CLA was due to less white and brown fat mass without changes in lean body mass or an alteration in feed intake compared to their respective control. t10-c12 CLA did not stimulate cell death in white adipose tissue. Immune cell infiltration was decreased in calorie restricted pair weight control mice, but not with CLA. t10-c12 CLA-induced weight loss did not improve hyperglycemia in db/db mice. In conclusion, the anti-adipogenic effects of t10-c12 CLA in vitro result from stabilization of β-catenin, which alters lipid droplet dynamics through HSL levels and perilipin-1 phosphorylation via the activation of PKCα. In contrast, t10-c12 CLA promotes loss of adipose tissue in vivo, possibly by activating β-catenin, but without influencing either adipogenesis or adipocyte clearance. This study suggests a novel mechanism for the anti-obesity effect of t10-c12 CLA, and highlights the possible side-effects associated with t10-c12 CLA consumption. / February 2016

Yeung Chi Hang, Thomas. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1999. / Includes bibliographical references (leaves 126-146). / Abstracts in English and Chinese. / Table of content / ACKNOWLEDGEMENT --- p.i / ABSTRACT --- p.ii / LIST OF ABBREVIATION --- p.vi / TABLE OF CONTENTS --- p.vii / Chapter Chapter1 --- General Introduction / Chapter 1.1 --- INTRODUCTION --- p.1 / Chapter 1.2 --- FORMATION OF CLA --- p.1 / Chapter 1.3 --- OCCURRENCE OF CLA IN FOODS --- p.5 / Chapter 1.4 --- PHYSIOLOGICAL EFFECTS OF CLA --- p.8 / Chapter 1.4.1 --- Anticarcinogenic Effects of CLA --- p.8 / Chapter 1.4.2 --- Antiatherogenic Effect of CLA --- p.11 / Chapter 1.4.3 --- Antioxidant Effect of CLA --- p.12 / Chapter 1.4.4 --- CLA and Immune Response --- p.13 / Chapter 1.4.5 --- CLA and Body Composition --- p.14 / Chapter Chapter2 --- Protective Effect of CLA on Copper-Induced Human LDL Oxidation / Chapter 2.1 --- INTRODUCTION --- p.17 / Chapter 2.1.1 --- Oxidative Modification of LDL and Atherosclerosis --- p.20 / Chapter 2.1.1.1 --- Understanding of LDL --- p.20 / Chapter 2.1.1.2 --- Oxidative Modification of LDL --- p.20 / Chapter 2.1.1.3 --- Role of Oxidative Modified LDL in Atherogenesis --- p.23 / Chapter 2.1.2 --- Antioxidants and Atherosclerosis --- p.25 / Chapter 2.1.3 --- Measuring TBARS Formation as an in vitro Index to Monitor LDL Oxidation --- p.26 / Chapter 2.1.4 --- CLA and Atherogenesis --- p.27 / Chapter 2.2 --- OBJECTIVE OF THE PRESENT STUDY --- p.28 / Chapter 2.3 --- MATERIALS AND METHODS --- p.29 / Chapter 2.3.1 --- Human LDL Isolation --- p.29 / Chapter 2.3.2 --- LDL Oxidation --- p.30 / Chapter 2.3.3 --- Thiobarbituric Acid Reactive Substances (TBARS) Assay --- p.30 / Chapter 2.4 --- STATISTICS --- p.31 / Chapter 2.5 --- RESULTS --- p.32 / Chapter 2.5.1 --- Inhibitory Effect of BSA on Human LDL Oxidation --- p.32 / Chapter 2.5.2 --- Pro-oxidant Effect of LA on Human LDL Oxidation --- p.32 / Chapter 2.5.3 --- Inhibitory Effect of CLA on Human LDL Oxidation --- p.32 / Chapter 2.6 --- DISCUSSION --- p.37 / Chapter 2.6.1 --- Effect ofBSA on Copper-Induced LDL Oxidation --- p.37 / Chapter 2.6.2 --- Effect of LA on Copper-Induced LDL Oxidation --- p.38 / Chapter 2.6.3 --- Protective Effect of CLA on Copper-Induced Human LDL Oxidation --- p.39 / Chapter Chapter3 --- Hypolipidemic Activity of CLA / Chapter 3.1 --- INTRODUCTION --- p.42 / Chapter 3.1.1 --- Total Cholesterol and LDL Cholesterol --- p.42 / Chapter 3.1.2 --- Triglyceride (TG) --- p.44 / Chapter 3.1.3 --- Hypolipidemic Effect of CLA --- p.45 / Chapter 3.1.4 --- Golden Syrian Hamster as an Animal Model of Cholesterol Metabolism --- p.46 / Chapter 3.2 --- OBJECTIVES OF THE PRESENT STUDY --- p.48 / Chapter 3.3 --- MATERIALS AND METHODS --- p.48 / Chapter 3.3.1 --- LA and CLA --- p.49 / Chapter 3.3.2 --- Animals --- p.49 / Chapter 3.3.3 --- Experiment1 --- p.49 / Chapter 3.3.4 --- Experiment2 --- p.51 / Chapter 3.3.5 --- "Determination of Serum TC, HDL-Cholesterol (HDL-C) and TG" --- p.54 / Chapter 3.3.6 --- Lipid analysis of Liver and Adipose Tissue --- p.54 / Chapter 3.3.6.1 --- Lipid Extraction and Separation of Different Lipid Species --- p.54 / Chapter 3.3.6.2 --- Acid-Catalyzed Methylation of Fatty Acids --- p.55 / Chapter 3.3.6.3 --- GLC Analysis of FAME --- p.55 / Chapter 3.3.7 --- Quantification of Tissue Cholesterol --- p.56 / Chapter 3.3.7.1 --- Cholesterol Extraction and Silylation --- p.56 / Chapter 3.3.7.2 --- GLC Analysis of TMS-Ether Derivative of Cholesterol --- p.56 / Chapter 3.4 --- STATISTICS --- p.57 / Chapter 3.5 --- RESULTS --- p.59 / Chapter 3.5.1 --- Body Weight and Food Intake --- p.59 / Chapter 3.5.2 --- "Effect of Dietary CLA Supplementation on Serum TG, TC and HDL-C" --- p.59 / Chapter 3.5.3 --- "Effect of Dietary CLA Supplementation on Hepatic TG, Phospholipid and Cholesterol" --- p.64 / Chapter 3.5.4 --- Effect of Dietary CLA Supplementation on Adipose Tissue TG and Cholesterol --- p.73 / Chapter 3.5.5 --- Effect of CLA Supplementation on Cholesterol Levels of Different Tissues --- p.73 / Chapter 3.6 --- DISCUSSION --- p.79 / Chapter 3.6.1 --- "Effect of CLA Supplementation on Serum TG, TC and HDL-C" --- p.79 / Chapter 3.6.2 --- "Effect of CLA Supplementation on Hepatic TG, PL and Cholesterol" --- p.81 / Chapter 3.6.3 --- Effect of CLA on Adipose Tissue TG and Cholesterol --- p.83 / Chapter 3.6.4 --- Implication of CLA Intake in Humans --- p.84 / Chapter Chapter4 --- Influences of Dietary CLA on Cholesterol Homeostasis / Chapter 4.1 --- INTRODUCTION --- p.86 / Chapter 4.2 --- NEUTRAL EFFECT OF DIETARY CLA SUPPLEMENTATION ON HMG-COA REDUCTASE ACTIVITY --- p.88 / Chapter 4.2.1 --- HMG-CoA Reductase as the Rate-Limiting Enzyme in Cholesterol Synthesis --- p.88 / Chapter 4.2.2 --- Objective of The Present Study --- p.91 / Chapter 4.2.3 --- Materials and Methods --- p.92 / Chapter 4.2.3.1 --- Preparation of Hepatic Microsome --- p.92 / Chapter 4.2.3.2 --- HMG-GoA Reductase Activity Assay --- p.92 / Chapter 4.2.4 --- Statistics --- p.93 / Chapter 4.2.5 --- Results --- p.94 / Chapter 4.2.6 --- Discussion --- p.96 / Chapter 4.3 --- DOWN-REGULATION OF THE INTESTINAL ACAT ACTIVITY BY CLA FEEDING --- p.97 / Chapter 4.3.1 --- Role of ACAT in Cholesterol Absorption --- p.97 / Chapter 4.3.2 --- Objective of The Present Study --- p.99 / Chapter 4.3.3 --- Materials and Methods --- p.100 / Chapter 4.3.3.1 --- Preparation of Intestinal Microsome --- p.100 / Chapter 4.3.3.2 --- ACAT Activity Assay --- p.100 / Chapter 4.3.4 --- Statistics --- p.101 / Chapter 4.3.5 --- Results --- p.102 / Chapter 4.3.6 --- Discussion --- p.104 / Chapter 4.4 --- ALTERATION OF FECAL EXCRETION BY DIETARY CLA --- p.105 / Chapter 4.4.1 --- Objective of The Present Study --- p.108 / Chapter 4.4.2 --- Materials and Methods --- p.109 / Chapter 4.4.2.1 --- Separation of Neutral and Acidic Sterols --- p.109 / Chapter 4.4.2.2 --- Neutral Sterol Analysis --- p.109 / Chapter 4.4.2.3 --- Acidic Sterol Analysis --- p.110 / Chapter 4.4.2.4 --- GLC Analysis of Neutral and Acidic Sterols --- p.110 / Chapter 4.4.3 --- Statistics --- p.113 / Chapter 4.4.4 --- Results --- p.114 / Chapter 4.4.4.1 --- Effect of CLA Supplementation on Fecal Output of Neutral Sterols --- p.114 / Chapter 4.4.4.2 --- Effect of CLA Supplementation on Fecal Output of Acidic Sterols --- p.114 / Chapter 4.4.5 --- Discussion --- p.118 / Chapter Chapter5 --- Conclusions --- p.123 / References --- p.126

Orientador: Cláudia Maria Bertan Membrive / Banca: Guilherme Pugliesi / Banca: Flávia Lombardi Lopes / Resumo: Mortalidade embrionária em bovinos, entre 15 e 19 dias de prenhez, pode ser promovida pela liberação de PGF2 endometrial. A síntese de PGF2 é inibida pela suplementação com compostos ricos em ácido linoléico, como a semente de girassol. Assim, objetivou-se avaliar o efeito e os mecanismos pelos quais a suplementação com semente de girassol atua na performance reprodutiva de fêmeas bovinas de corte. Hipotetizou-se que tal suplementação promove um incremento na taxa de concepção de receptoras de embriões produzidos in vitro submetidas à TETF e que tal efeito decorra de modificações na composição lipídica plasmática e endometrial, alterações na expressão de transcritos envolvidos na biossíntese de eicosanoides e/ou modificações no número e/ou morfometria das glândulas endometriais. No Experimento 1, novilhas mestiças zebuínas submetidas ao protocolo de TETF suplementadas com semente de girassol, por 22 dias a partir da remoção do dispositivo de progesterona, apresentaram maior taxa de concepção em relação ao grupo controle (55,66% vs. 36,94%; P < 0,01). No Experimento 2, vacas Nelore suplementadas com semente de girassol apresentaram maiores concentrações plasmáticas de colesterol total, LDL e HDL; modificações na composição lipídica endometrial e alterações na expressão de transcritos envolvidos na biossíntese de eicosanoides. Conclui-se que a suplementação com semente de girassol aumenta a taxa de concepção por modificar a composição lipídica plasmática e endometrial, a expressão de transcritos envolvidos na biossíntese de eicosanoides e número... ((Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Embryonic mortality in cattle, between 15 and 19 days of pregnancy, can be promoted by the release of endometrial PGF2. Synthesis of PGF2 is inhibited by supplementation with compounds rich in linoleic acid such as sunflower seed. This study aimed to evaluate the effects and the mechanisms by which supplementation with sunflower seed acts on reproductive performance of beef cows. It was hypothesized that such supplementation promotes an increase on conception rate of in vitro-produced embryos subjected to FTET; and that this effect arises from changes in plasma lipid composition and endometrial changes in the expression of transcripts involved in the biosynthesis of eicosanoids and/or changes in the number and/or endometrial gland morphology. In Experiment 1, zebu crossbred heifers submitted to the FTET protocol supplemented with sunflower seed, for 22 days from the removal of the progesterone device, showed higher conception rate in the control group (55.66% vs. 36.94% ; P < 0.01). In Experiment 2, Nelore cows supplemented with sunflower seed showed higher plasma concentrations of total cholesterol, LDL and HDL, changes in endometrial lipid composition and changes in the expression of transcripts involved in the biosynthesis of eicosanoids. It was concluded that supplementation with sunflower seeds increases the conception rate by modifying the lipid composition of the plasma and the endometrium, the expression of transcripts involved in the biosynthesis of eicosanoids and number and morphometry of the endometrial glands / Mestre

The effects of conjugated linoleic acid (CLA) on lipogenesis and preadipocyte proliferation in young pigs were evaluated in two separate experiments. The first compared dietary effects of linoleic acid, beef tallow, and CLA on composition, lipogenesis, and DNA synthesis. Eighteen pigs weaned at 17 d of age were allotted randomly to corn-based diets supplemented with 1.5% corn oil, 1.5% tallow, or 1.5% CLA. The second experiment evaluated the effects of CLA included with diets high in polyunsaturated fat or beef tallow. Twenty-four pigs weaned at 17 d of age were allotted randomly to one of four corn-based diets supplemented with: 15% corn oil, 12% corn oil + 3% CLA, 15% tallow, and 12% tallow + 3% CLA. The piglets in both trials were fed a basal diet for 7 d and their respective diet for 35 d. [U-14C]Glucose incorporation into total lipids was (experiment 1): 10.64, 11.04, 13.64; (experiment 2): 21.15, 17.54, 21.34, and 19.52 nmol/(105 cells per h) for subcutaneous (s.c.) adipose tissue from corn oil, tallow, CLA; corn oil, corn oil + CLA, tallow, and tallow + CLA-fed piglets, respectively. Tritiated thymidine incorporation into DNA was not different in s.c. adipocytes across treatment groups, but was 5,581, 2,794, 6,573, and 3,760 dpm/(105 cells per h) in s.c. stromal vascular cells from corn oil, corn oil + CLA, tallow, and tallow + CLA-fed piglets, respectively (CLA main effect p<0.034). Additionally, there was a greater proportion of s.c. adipocytes in the smaller, 180-pL cell fraction from the corn oil + CLA-fed pigs (p<0.0074). CLA in the diet increased the s.c. adipose tissue concentration of 18:0 and decreased 16:1 and 18:1 (p<0.05), suggesting depression of stearoyl-coenzyme A desaturase (SCD) enzyme activity in the CLA-fed pigs. The concentration of CLA isomers was raised only slightly in s.c. adipose tissue with the addition of CLA to the diets even though the CLA oil contained 62% CLA isomers. No effects on the growth of young pigs were observed. However, CLA caused a more saturated fatty acid composition and may suppress preadipocyte proliferation, apparent SCD activity, and lipid filling of smaller cells.

<p>The fatty acid linoleic acid has been identified as a potential mediator of atherosclerotic plaque development. Treatment of monocytes with linoleic acid leads to an increase in monocyte adhesion to endothelial cells under flow conditions; however, the mechanisms through which linoleic acid affect monocyte adhesion remain unclear. Using a combination of micropipette aspiration techniques and fluorescent microscopy, I tested the hypothesis that linoleic acid increases membrane tether formation between monocytes and endothelial cells. </p><p>Treatment of U937 monocytes with free linoleic acid or albumin-bound linoleic acid reduced the cortical tension of the monocytes. The effects of albumin-bound linoleic acid on the membrane were governed by the exchange of linoleic acid from albumin to the membrane and by the removal of fatty acids from the membrane by fatty acid binding sites on albumin. </p><p>The frequency of tether formation between U937 monocytes and TNF-α stimulated HUVECs increased following treatment with free linoleic acid or albumin-bound linoleic acid. The increase in tether frequency was not due to an increase in monocyte deformability or adhesion receptor expression. Tether extraction occurred primarily through E-selectin. Treatment with free linoleic acid increased the localization of E-selectin to clathrin-coated pits suggesting an increase in the formation of nanoclusters of E-selectin on HUVECs. The increase in tether frequency was blocked by the U73122 phospholipase C inhibitor indicating that linoleic acid increased monocyte adhesion through a phospholipase C mediated mechanism.</p><p>Treatment with free linoleic acid did not affect the threshold force for tether extraction or the effective viscosity of tethers extracted from HUVECs, but it decreased the threshold force for tether extraction from U937 monocytes and increased the effective tether viscosity. Treatment with U73122 blocked the reduction in the threshold force indicating that linoleic acid affected the regulation of the membrane adhesion energy through the hydrolysis of PIP2 by phospholipase C.</p><p>The results of the study indicated that linoleic acid promoted membrane tether formation by increasing E-selectin bond formation and reducing the adhesion energy between the U937 plasma membrane and the actin cytoskeleton through the hydrolysis of PIP2 by phospholipase C.</p> / Dissertation

The effects of conjugated linoleic acid (CLA) on lipogenesis and preadipocyte proliferation in young pigs were evaluated in two separate experiments. The first compared dietary effects of linoleic acid, beef tallow, and CLA on composition, lipogenesis, and DNA synthesis. Eighteen pigs weaned at 17 d of age were allotted randomly to corn-based diets supplemented with 1.5% corn oil, 1.5% tallow, or 1.5% CLA. The second experiment evaluated the effects of CLA included with diets high in polyunsaturated fat or beef tallow. Twenty-four pigs weaned at 17 d of age were allotted randomly to one of four corn-based diets supplemented with: 15% corn oil, 12% corn oil + 3% CLA, 15% tallow, and 12% tallow + 3% CLA. The piglets in both trials were fed a basal diet for 7 d and their respective diet for 35 d. [U-14C]Glucose incorporation into total lipids was (experiment 1): 10.64, 11.04, 13.64; (experiment 2): 21.15, 17.54, 21.34, and 19.52 nmol/(105 cells per h) for subcutaneous (s.c.) adipose tissue from corn oil, tallow, CLA; corn oil, corn oil + CLA, tallow, and tallow + CLA-fed piglets, respectively. Tritiated thymidine incorporation into DNA was not different in s.c. adipocytes across treatment groups, but was 5,581, 2,794, 6,573, and 3,760 dpm/(105 cells per h) in s.c. stromal vascular cells from corn oil, corn oil + CLA, tallow, and tallow + CLA-fed piglets, respectively (CLA main effect p<0.034). Additionally, there was a greater proportion of s.c. adipocytes in the smaller, 180-pL cell fraction from the corn oil + CLA-fed pigs (p<0.0074). CLA in the diet increased the s.c. adipose tissue concentration of 18:0 and decreased 16:1 and 18:1 (p<0.05), suggesting depression of stearoyl-coenzyme A desaturase (SCD) enzyme activity in the CLA-fed pigs. The concentration of CLA isomers was raised only slightly in s.c. adipose tissue with the addition of CLA to the diets even though the CLA oil contained 62% CLA isomers. No effects on the growth of young pigs were observed. However, CLA caused a more saturated fatty acid composition and may suppress preadipocyte proliferation, apparent SCD activity, and lipid filling of smaller cells.