Fatty acids (FAs) are used as trophic markers in aquatic food web studies, but few studies have quantified individual variability in FAs profiles over several sites in a range of conditions. I investigated whether FAs profiles of yellow perch (YP), Perca flavescens, vary with body size and between lakes with and without largemouth (Micropterus salmoides), and smallmouth bass (Micropterus dolomieu), the most common and abundant piscivores in lakes of the region. I analyzed the FAs of YP as well as zooplankton, benthic invertebrates, and prey fish collected from eight lakes where bass were either present or absent in the Outaouais region over the summer of 2016. I compared the growth rate of YP between the lakes and the YP in lakes without bass exhibited a slower growth rate. I also compared the FA signatures of YP using redundancy analysis (RDA). 23 FAs could be identified and quantified. FAs profiles were dominated by palmitic- (16:0), oleic- (18:1), stearic- (18:0), and palmitoleic acid (16:1). The RDA analysis based on FAs profiles of YP revealed variation along two main gradients (the presence of bass and the date of capture). The first two eigenvectors accounted for 42.1% of the variation (RDA1=27.6% and 2=14.6%). Arachidonic (20:4) and docosatrienoic (22:3) were the most correlated FAs with RDA1. Due to the sampling period, it was impossible to determine if the observed effects were due to the date of capture, the presence of bass, or a change in metabolism, but the last two were deemed as the most plausible explanations. It was concluded that the utility of FA signatures to quantify diet in natural environments is limited and that FAs might be more successful as markers in primary consumers and other lower trophic levels. It is recommended that a combination of FAs, stable isotopes, and modelling should be used in the future.

京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第22664号 / 農博第2419号 / 新制||農||1080(附属図書館) / 学位論文||R2||N5295(農学部図書室) / 京都大学大学院農学研究科応用生物科学専攻 / (主査)教授 菅原 達也, 教授 佐藤 健司, 教授 澤山 茂樹 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DGAM

<p>PUFAs serve many important biological and physiological functions within the body and are key for the structure and function of the brain. Omega-6 and omega-3 PUFAs are found in abundance in phospholipids of neuronal membranes that impart structure and function of neurons. Omega-6 PUFAs are instrumental for neurotransmission, neuronal elongation, and neuritogenesis; whereas, omega-3 PUFAs promote neuronal maturation through synaptogenesis. The types of PUFAs incorporated into neuronal membranes is especially important in determining the progression of development. The processes of neurogenesis, neuritogenesis and elongation require large amounts of PUFAs to be incorporated into the membrane phospholipids. To accommodate for the high PUFA needs, maternal dietary PUFA, especially EPA and DHA, recommendations, mobilization of fatty acids into maternal circulation increases, and the accretion rate of PUFA are increased. If maternal nutritional inadequacy of PUFAs occurs during gestation, this can result in impaired cognition, behavioral abnormalities, reduced number of neurons, decreased dendric arborization, altered myelin sheath, and a reduction in brain size. </p> <p> Even though the essentiality of PUFAs in neuronal development is widely accepted, the mechanism is not well understood. There is a lack of consensus in the current literature on the effects of individual PUFAs on each stage of neuronal development and the molecular pathways involved. Despite the inconsistent evidence, the results of numerous studies have consistently suggested that neuronal membrane PUFA composition is associated with neuronal development outcomes, such as number of neurons and neurites, neurite length, and neurotransmitter release. The varying results may be the result of methodological discrepancies with PUFA composition and concentrations, as well as the models used for neuronal development. Additionally, very few studies have taken into consideration the competitive relationship of omega-6 and omega-3 PUFAs in the body when assessing neurodevelopment. </p> <p> This thesis was focused on addressing the role of PUFAs in neuronal development and to address some of the inconsistencies in the literature. attempt to elucidate the individual roles of ALA, ARA, and EPA on neuronal membrane composition and neuronal development. The aim of the thesis research project was to assess the impact of individual PUFAs on neuronal membrane PUFA composition, the membrane n-6:n-3 ratio, and the morphology of SH-SY5Y cells during differentiation. The results of this study demonstrated that supplementation of individual PUFAs alters membrane PUFA composition and the n-6:n-3 ratio. However, there wasn’t a significant effect on neurite number with ALA, ARA, and EPA treatment. Lastly, ARA treatment decreased cell viability compared to the other treatments and the BSA control. Furthermore, additional research needs to be conducted to address other morphological measures and functional outcomes, such as neurotransmitter production and release.</p>

Obesity, one of the most serious health problems of the 21st century, often occurs as a result of an imbalance between energy intake and energy expenditure. Dietary lipids play an important role in the development of obesity, partly because they represent the richest source of energy amongst all macronutrients. It is, however, not only the amount of consumed lipids, but also the composition of fatty acids, which strongly influences health effects of a particular diet. Saturated fatty acids (SFA) are generally considered as unhealthy due to their pro-inflammatory and lipotoxic properties, while monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) represent a healthier alternative, as they are more readily oxidized and do not disrupt biochemical properties of cellular membranes. Amongst PUFA, PUFA of n-3 series (Omega-3) represent an utterly unique class of lipids that have been documented to protect against cardiovascular disease and dyslipidemia in men and improve insulin sensitivity and glucose tolerance primarily in animal models of obesity. Some molecular mechanisms of Omega-3 action have been already uncovered, such as the modification of biological membranes composition, activation of various transcription factors and membrane receptors, and their role as precursors for...

© 2016 Elsevier B.V. Background Polyunsaturated fatty acids (PUFA) are known to be present and/or enriched in vegetable and fish oils. Among fatty acids, n-3 PUFA are generally considered to be protective in inflammation-related diseases. The guidelines for substituting saturated fatty acids for PUFAs have been highly publicized for decades by numerous health organizations. Recently, however, the beneficial properties of n-3 PUFA are questioned by detailed analyses of multiple randomized controlled clinical trials. The reported heterogeneity of results is likely due not only to differential effects of PUFAs on various pathological processes in humans, but also to the wide spectrum of PUFA's derived products generated in vivo. Scope of review The goal of this review is to discuss the studies focused on well-defined end-products of PUFAs oxidation, their generation, presence in various pathological and physiological conditions, their biological activities and known receptors. Carboxyethylpyrrole (CEP), a DHA-derived oxidized product, is especially emphasized due to recent data demonstrating its pathophysiological significance in many inflammation-associated diseases, including atherosclerosis, hyperlipidemia, thrombosis, macular degeneration, and tumor progression. Major conclusions CEP is a product of radical-based oxidation of PUFA that forms adducts with proteins and lipids in blood and tissues, generating new powerful ligands for TLRs and scavenger receptors. The interaction of CEP with these receptors affects inflammatory response, angiogenesis, and wound healing. General significance The detailed understanding of CEP–mediated cellular responses may provide a basis for the development of novel therapeutic strategies and dietary recommendations.

Hyperlipidemia caused by a diet high in saturated fat can lead to visceral fat weight gain, obesity, and metabolic syndrome. Being over-weight from visceral fat has been linked to increased risk of developing most age-related diseases and disability, along with a lower income potential and quality of life. However, researchers are just beginning to understand the biological mechanisms that regulate the conversion of excess calories into visceral fat storage rather than glycogen or muscle. Epidemiological studies have repeatedly shown a comorbid association between age-related diseases involving hyperlipemia and circulating levels of uric acid, but not a direct association. This study utilized archival data from 31 healthy, middle-aged adults, who participated in a randomized, double-blind, crossover clinical trial on blood markers of lipidemia and inflammation following a high saturated fat (HSF) verses a "healthy" polyunsaturated fat (PUFA) meal. This primary study was conducted and funded by the National Institute on Aging. A secondary analysis of this data using Pearson's correlation with least squares (2-tailed) regression modeling found that when stratified by gender, baseline uric acid level was an independent and significant predictor of the lipemic response from the HSF, but not the PUFA meal. The linear regression plots indicated that males with uric acid levels above 4.5, and females above 3.0 mg/dL, had a progressively increased lipemic response to the HSF meal. The public health utility of this finding may include the clinical use of the gender-specific linear regression plots of uric acid values to identify and advise individuals at risk for hyperlipidemia from a diet high in saturated fats.

The Western diet is commonly consumed by industrialized societies and characterized by an increased consumption of vegetable oils rich in omega-6 (n-6) fatty acids. This results in a higher ratio of omega-6 to omega-3 (n-3) fatty acids in the diet. Omega-6 polyunsaturated fatty acids (PUFA) are believed to induce a pro-inflammatory response in the body. Therefore, this change in PUFA concentration and/or ratio of n-6:n-3 in the Western diet may contribute to colorectal cancer (CRC) risk. Five identical diets, varying only in PUFA concentration and n-6:n-3 ratio, were fed to mice dosed with a carcinogen and an inflammatory accent (AOM+DSS). The diets included: 1.) AIN-93G, control diet, containing 7% (kcal) dietary PUFA, 7:1 n-6:n-3 ratio, 2.) 2.5% dietary PUFA 1:1 n-6:n-3 ratio, 3.) 2.5% PUFA 20:1 n-6:n-3, 4.) 10% PUFA 1:1 n-6:n-3, and 5.) 10% PUFA 20:1 n-6:n-3. PUFA ratio had a significant effect on tumor size. Diets having an n-6:n-3 ratio of 1:1 resulted in significantly larger tumors than diets with an n-6:n-3ratio of 20:1. Mice fed either the AIN-93G or 2.5% 1:1 diet had the highest number of tumors compared to the other experimental diets. From these results, it appears that the dietary PUFA profile influences the etiology of CRC. Studies investigating CRC commonly use rodent models to investigate human diseases. Typically rodents are fed diets formulated to promote growth and heath, however these diets are considerably different than the Western diet in terms of macro- and micronutrients. Diet is known to influence CRC incidence, which led to the development of the Total Western Diet (TWD) by Hinze and colleagues. The TWD is a rodent diet that uses purified ingredients to match the macro- and micronutrient composition of the average American diet. However, the complex nature of whole-foods is also known to impact colon health, so the TWD was redesigned. The TWD-2 is the only whole-foods-based rodent diet that emulates the macro- and micronutrient consumption of the average American. Initiating studies using the TWD-2, in place of the AIN diets, will hopefully make the rodent a better model for human disease research.

京都大学 / 0048 / 新制・論文博士 / 博士(農学) / 乙第12822号 / 論農博第2795号 / 新制||農||1025(附属図書館) / 学位論文||H26||N4817(農学部図書室) / 31309 / 京都大学農学研究科食品生物科学専攻 / (主査)教授 喜多 恵子, 教授 三上 文三, 教授 栗原 達夫 / 学位規則第4条第2項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

付記する学位プログラム名: 充実した健康長寿社会を築く総合医療開発リーダー育成プログラム / 京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第21794号 / 工博第4611号 / 新制||工||1718(附属図書館) / 京都大学大学院工学研究科合成・生物化学専攻 / (主査)教授 梅田 眞郷, 教授 跡見 晴幸, 教授 秋吉 一成 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM

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