고지방 식이로 유도된 비만 마우스에서 잣기름이 체지방량 조절 관련 요인에 미치는 영향

학위논문 (석사)-- 서울대학교 대학원 : 식품영양학과, 2013. 2. 한성림.Korean pine nut oil (PNO) has been reported to suppress appetite by increasing satiety hormone release. However, the effects of PNO on the expression of satiety hormone receptors and neuropeptides have not been studied. Also, there is limited information on whether PNO has an influence on lipid metabolism. In this study, 5-wk-old C57BL/6 mice were fed control diets containing 10% kcal fat from PNO or soybean oil (SBO) (PC or SC) or high-fat diets containing 35% kcal fat from lard and 10% kcal fat from PNO or SBO (PHF or SHF) for 12 weeks. The mRNA expression levels of cholecystokinin related genes, ghrelin related genes, neuropeptides, and genes associated with lipid metabolism in the small intestine and white adipose tissue were quantified by real-time PCR. Overall, PNO-fed mice gained less weight (P = 0.01) and had less white adipose tissue (P < 0.01) despite no difference in daily food intake between SBO- and PNO-fed mice. PC and PHF groups had less amount of white adipose tissue compared with SC group (30% less, P = 0.05) and SHF group (18% less, P = 0.03), respectively. Altogether, PNO-fed mice had significantly higher mRNA expression of Growth hormone secretagogue receptor (Ghsr, P = 0.03) and Agouti-related peptide (Agrp, P = 0.02), and tended to have higher mRNA expression of Pro-opiomelanocortin (Pomc, P = 0.08) and Cocaine- and amphetamine-regulated transcript (Cart, P = 0.06) in hypothalamus. PC group had higher Ghsr mRNA expression than SC group (1.23-fold, P = 0.02). PHF group had higher Agrp mRNA expression than SHF group (2.16-fold, P = 0.02). Collectively, PNO-fed mice had lower mRNA expression of jejunal Cd36 (P = 0.03) and epididymal Lipoprotein lipase (Lpl, P = 0.02). PC group had lower Lpl mRNA expression than SC group (38% less, P = 0.04). Overall, PNO-fed mice tended to have lower jejunal Apolipoprotein A-IV mRNA expression (Apoa4, P = 0.07) and higher epididymal β3-adrenergic receptor mRNA expression (Adrb3, P = 0.08). Higher expression of Ghsr and Agrp mRNA in PNO-fed mice indicates that PNO-fed mice received stronger signal promoting energy consumption which might be due to less amount of white adipose tissue. The tendency of higher Pomc and Cart mRNA expression in PNO-fed mice suggests that mice in SHF group might have impaired POMC/CART pathway and failed to upregulate Pomc and Cart mRNA expression despite their higher body weight. The lower expression of Cd36 and Lpl mRNA, and the tendency of lower Apoa4 mRNA and higher Adrb3 mRNA expression in PNO-fed mice imply that PNO was less efficiently absorbed and stored in the body than SBO, which led to less fat accumulation in PNO-fed mice. In conclusion, PNO reduced weight gain and alleviated the possibility of POMC/CART pathway dysregulation in high-fat diet-fed mice. The lower weight gain of PNO-fed mice seemed to be due to the effect of PNO on lipid metabolism.Abstract ------------------------------------------------------------------ⅰ Contents ----------------------------------------------------------------- ⅳ List of Tables ------------------------------------------------------------- ⅵ List of Figures ------------------------------------------------------------ ⅶ List of Abbreviations ------------------------------------------------------ ⅷ Ⅰ. Introduction ------------------------------------------------------------ 1 Ⅱ. Literature Review 1. Gastrointestinal regulation of energy homeostasis ----------------------- 3 2. Hypothalamic regulation of energy homeostasis ------------------------ 9 3. Lipid absorption in the small intestine --------------------------------- 12 4. Lipid metabolism in the white adipose tissue -------------------------- 16 5. Characteristics of pine nut oil ----------------------------------------- 20 Ⅲ. Materials and Methods 1. Animals and diets ---------------------------------------------------- 24 2. Determination of serum leptin concentration ---------------------------- 28 3. Determination of serum triglyceride and cholesterol concentrations ------ 29 4. RNA extraction and cDNA synthesis ----------------------------------- 31 5. Quantification of the gene expression ---------------------------------- 33 6. Statistical analysis --------------------------------------------------- 37 Ⅳ. Results 1. Body weight changes, food intake, food efficiency, white adipose tissue weight, and serum leptin concentration ------------------------------------------------------- 38 2. Serum triglyceride and cholesterol concentrations --------------------- 40 3. Expression of genes involved in appetite control ------------------------ 42 4. Expression of genes involved in lipid absorption ------------------------ 46 5. Expression of genes involved in body fat accumulation ----------------- 48 Ⅴ. Discussion ------------------------------------------------------------ 51 Ⅵ. Summary ------------------------------------------------------------- 58 Ⅶ. References ------------------------------------------------------------ 60 Appendices --------------------------------------------------------------- 69 국문초록 ------------------------------------------------------------------ 74Maste

Regulation of Thermogenic and Inflammatory Response in Adipose Tissue by 18-Carbon Fatty Acids

Dietary fatty acids, in particular long-chain fatty acids (LCFA), are involved in the regulation of metabolic, oxidative, and inflammatory responses. This is a mechanism by which fatty acids participate in the regulation of energy homeostasis and impact development of obesity, type 2 diabetes, and cardiovascular diseases. White and brown adipose tissue play a significant role in energy storage and expenditure through fatty acid uptake and oxidation. LCFA, especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), have been reported to induce thermogenesis by activating brown and beige adipocytes to oxidize more fuel molecules. However, the effects of 18-carbon (18-C) LCFA with same length but with different number and position of double bonds on metabolism and expression of thermogenic genes in adipose tissue has not been well studied. It is important to study this group of fatty acids because they are some of the most abundant fatty acid class in human diets, and there are multiple isomers in terms of the number and the position of double bonds in their structure. Therefore, the research described in this dissertation were conducted to investigate effects of 18-C fatty acids on regulation of expression of metabolic and brown-specific genes. To determine thermogenic responses of different adipocyte cell types with distinct stages of differentiation into mature white adipocytes to 18-C fatty acids, fully differentiated C3H10T1/2, 3T3-L1, murine, or porcine primary adipocytes were treated with 18-C fatty acids, including stearic acid (STA; C18:0), oleic acid (OLA; C18:1), linoleic acid (LNA; C18:2, n-6), α-linolenic acid (ALA; C18:3, n-3), γ-linolenic acid (GLA; C18:3, n-6), and pinolenic acid (PLA, C18:3, n-6), with or without norepinephrine (NE). In murine primary adipocytes, LNA, ALA, GLA, and PLA upregulated expression of thermogenic genes; however, other types of adipocytes did not respond to these PUFA. Although NE increased thermogenic gene expression in C3H10T1/2 adipocytes, there was no effect of NE in 3T3-L1 adipocytes. In porcine primary adipocytes, which lack of uncoupling protein 1 (UCP1), NE upregulated oxidative gene expression, suggesting that increasing fatty acid oxidation may be a compensatory mechanism to overcome absence of UCP1 in pigs. This study indicates that different adipocytes have different thermogenic responses to 18-carbon fatty acids and β-adrenergic agonist. The second experiment was conducted to compare thermogenic effects of 18-C fatty acids in vivo. Mice (C57BL/6J) were fed high-fat diets (HFD) made of vegetable oils with different composition of 18-C fatty acids, including shea butter (SHB; STA-rich fat), olive oil (OO; OLA-rich oil), safflower oil (SFO; LNA-rich oil), and soybean oil (SBO; ALA-rich fat) for 12 weeks. This was followed with or without a terminal NE injection. Compared to SHB group that had the lowest thermogenic gene expression, OO, SFO, and SBO groups had lower weight gain and body fat accumulation. Among HFD-fed groups, OO group had the lowest white fat mass due to its highest heat production level, which led to improved glucose metabolism. Feeding of SFO, with the highest n-6:n-3 ratio of fatty acids, downregulated oxidative gene expression and upregulated lipogenic gene expression. Mice that were fed HFD had lower basal (without NE injection) brown-specific gene expression in both subcutaneous and epididymal white adipose tissue (WAT), and had diminished NE-induced upregulation of thermogenic genes in brown adipose tissue (BAT). These data indicate that quantity and quality of dietary fatty acids, especially the position of the double bonds of fatty acids, may be important in regulating their effects on thermogenic gene expression. LCFA are also involved in regulation of inflammatory responses, which are known to cause dysregulation of lipid metabolism and thermogenesis, effects of HFD differing in 18-C fatty acid composition on inflammatory and thermogenic markers were also investigated. C57BL/6J mice were fed HFD made of SHB (saturated fatty acid-rich), OO (monounsaturated fatty acid-rich), and SBO (polyunsaturated fatty acid-rich) for 4 weeks with or without a terminal injection of lipopolysaccharides (LPS). Mice fed OO had the highest BAT mass and hypothalamic leptin receptor expression, indicating that they may have a higher thermogenesis than other groups because of the involvement of BAT in non-shivering thermogenesis. In contrast, SBO-fed mice with the highest weight gain had higher expression of pro-inflammatory cytokines and downregulation of oxidative genes in WAT compared to other groups. This is because upregulation of pro-inflammatory cytokines is associated with insulin resistance and lower thermogenic gene expression in WAT. In support of this, exposure to LPS has been shown to suppress thermogenic and oxidative gene expression in NE-treated murine primary adipocytes. However, there was no fatty acid-specific effect in the regulation of response to inflammatory effect of LPS. (Abstract shortened by ProQuest.

Effects of Diets Differing in Composition of 18-C Fatty Acids on Adipose Tissue Thermogenic Gene Expression in Mice Fed High-Fat Diets

Dietary fatty acids play important roles in the regulation of fat accumulation or metabolic phenotype of adipocytes, either as brown or beige fat. However, a systematic comparison of effects of diets with different composition of 18-C fatty acids on browning/beiging phenotype has not been done. In this study, we compared the effects of different dietary fats, rich in specific 18-carbon fatty acids, on thermogenesis and lipid metabolism. Male C57BL/6 mice were fed a control diet containing 5.6% kcal fat from lard and 4.4% kcal fat from soybean oil (CON) or high-fat diets (HFD) containing 25% kcal from lard and 20% kcal fat from shea butter (stearic acid-rich fat; SHB), olive oil (oleic acid-rich oil; OO), safflower oil (linoleic acid-rich oil; SFO), or soybean oil (mixed oleic, linoleic, and α-linolenic acids; SBO) ad libitum for 12 weeks, with or without a terminal 4-h norepinephrine (NE) treatment. When compared to SHB, feeding OO, SFO, and SBO resulted in lower body weight gain. The OO fed group had the highest thermogenesis level, which resulted in lower body fat accumulation and improved glucose and lipid metabolism. Feeding SFO downregulated expression of lipid oxidation-related genes and upregulated expression of lipogenic genes, perhaps due to its high n-6:n-3 ratio. In general, HFD-feeding downregulated Ucp1 expression in both subcutaneous and epididymal white adipose tissue, and suppressed NE-induced Pgc1a expression in brown adipose tissue. These results suggest that the position of double bonds in dietary fatty acids, as well as the quantity of dietary fat, may have a significant effect on the regulation of oxidative and thermogenic conditions in vivo

Korean Pine Nut Oil Attenuated Hepatic Triacylglycerol Accumulation in High-Fat Diet-Induced Obese Mice

Korean pine nut oil (PNO) has been reported to influence weight gain and lipid metabolism. We examined whether PNO replacement in a high-fat diet (HFD) can ameliorate HFD-induced hepatic steatosis. Five-week-old male C57BL mice were fed control diets containing 10% of the energy from fat from PNO or soybean oil (SBO) (PC, SC) or HFDs with 45% of the energy from fat, with 10% from PNO or SBO and 35% from lard (PHFD, SHFD), for 12 weeks. Body weight gain and amount of white adipose tissue were lower in PHFD (10% and 18% lower, respectively) compared with SHFD. Hepatic triacylglycerol (TG) level was significantly lower in PHFD than the SHFD (26% lower). PNO consumption upregulated hepatic ACADL mRNA levels. The hepatic PPARG mRNA level was lower in the PC than in the SC. Expression of the sirtuin (SIRT) 3 protein in white adipose tissue was down-regulated in the SHFD and restored in the PHFD to the level in the lean control mice. SIRT 3 was reported to be upregulated under conditions of caloric restriction (CR) and plays a role in regulating mitochondrial function. PNO consumption resulted in lower body fat and hepatic TG accumulation in HFD-induced obesity, which seemed to be associated with the CR-mimetic response

A robust symmetrical electrode with layered perovskite structure for direct hydrocarbon solid oxide fuel cells: PrBa0.8Ca0.2Mn2O5+d

Symmetrical solid oxide fuel cells (SOFCs), where the same material is used as both the anode and the cathode, have gained increasing attention due to a number of attractive benefits compared to the conventional SOFC such as a simplified fabrication procedure, reduced processing costs, minimized compatibility issues, as well as enhanced stability and reliability. Since the anode is in a reducing environment while the cathode is in an oxidizing environment, the symmetrical SOFC electrode should be chemically and structurally stable in both environments. Herein, we propose a highly stable symmetrical SOFC electrode, a layered perovskite Ca doped PrBaMn2O5+?? (PBCMO). The electrical conductivity of this electrode is very high in a reducing atmosphere and suitable in an oxidizing atmosphere. Furthermore, the PBCMO symmetrical electrode demonstrates excellent electrochemical performance and durability in various hydrocarbon fuels as well as hydrogen.close

Adipose-derived stem cell-released osteoprotegerin protects cardiomyocytes from reactive oxygen species-induced cell death

Abstract Background The paracrine effect is likely the major mechanism of the adipose-derived stem cell (ASC)-mediated cardioprotective effect. However, the exact composition and nature of ASC-released paracrine factors remain elusive. In the present study, we examined the effect of osteoprotegerin (OPG), a stem cell-released decoy receptor for death ligand, on the survival of cardiomyocytes exposed to oxidative stress. Methods The production of OPG from ASCs under oxidative stress was determined by ELISA and immunohistochemistry. The effects of OPG and the OPG-containing conditioned media of ASCs on the survival of cardiomyocytes were determined using a cell viability assay. Results Hydrogen peroxide (H2O2) significantly increased OPG production from ASCs in vitro, and OPG production from the ASCs transplanted into the ischemia–reperfusion-injured heart was also observed. OPG significantly attenuated cardiomyocyte death in vitro. OPG-containing conditioned media of ASCs also significantly protected cardiomyocytes. Delivery of siRNA specific to OPG significantly decreased the OPG production of ASCs, and also offset the protective effect of the conditioned media of ASCs. Conclusions Our study strongly suggests that OPG is one of the prosurvival factors released from ASCs that may contribute to the ASC-mediated cardioprotection and calls for further studies to elucidate detailed underlying mechanisms

MicroRNA-Mediated Down-Regulation of Apoptosis Signal-Regulating Kinase 1 (ASK1) Attenuates the Apoptosis of Human Mesenchymal Stem Cells (MSCs) Transplanted into Infarcted Heart

Stem cell therapy using adult stem cells, such as mesenchymal stem cells (MSCs) has produced some promising results in treating the damaged heart. However, the low survival rate of MSCs after transplantation is still one of the crucial factors that limit the therapeutic effect of stem cells. In the damaged heart, oxidative stress due to reactive oxygen species (ROS) production can cause the death of transplanted MSCs. Apoptosis signal-regulating kinase 1 (ASK1) has been implicated in the development of oxidative stress-related pathologic conditions. Thus, we hypothesized that down-regulation of ASK1 in human MSCs (hMSCs) might attenuate the post-transplantation death of MSCs. To test this hypothesis, we screened microRNAs (miRNAs) based on a miRNA-target prediction database and empirical data and investigated the anti-apoptotic effect of selected miRNAs on human adipose-derived stem cells (hASCs) and on rat myocardial infarction (MI) models. Our data indicated that miRNA-301a most significantly suppressed ASK1 expression in hASCs. Apoptosis-related genes were significantly down-regulated in miRNA-301a-enriched hASCs exposed to hypoxic conditions. Taken together, these data show that miRNA-mediated down-regulation of ASK1 protects MSCs during post-transplantation, leading to an increase in the efficacy of MSC-based cell therapy