• Journal of Life Science
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• v.23 no.12
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• pp.1509-1515
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• 2013

The term lipotoxicity has been used to describe how excess lipid accumulation leads to cellular dysfunction and death in non-adipose tissues, including skeletal muscle. While lipotoxicity has been found in cultured skeletal muscle cells with high-fat feeding, the consequences of lipotoxicity in vivo are still unknown, particularly in Type-I muscle, which is metabolically affected by lipotoxicity. The aim of this study was to investigate the effects of a high-fat diet on changes in the morphology and apoptotic protein expression of Type-I muscle loss in rats. The rats were fed either a high-fat diet or a normal diet for six weeks, and then lipid accumulation, inflammation response, and nucleus infiltration were measured, and PARP protein expression was cleaved by Oil Red O staining, H & E staining, and Western blot, respectively. Lipid accumulation, inflammation response, nucleus infiltration, and cleaved PARP protein expression were significantly (p<0.05) higher in the high-fat diet group than they were in the normal diet group. The weight of Type-I muscle tended to be lower in the high-fat diet group compared to the normal diet group, but the difference was not statistically significant. These results indicate that a high-fat diet triggers cell death in Type-I muscle via lipotoxicity, which suggests that a high-fat diet may be associated with sarcopenia.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.9
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• pp.1194-1199
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• 2006

Effects of Korean traditional soybean fermented foods on weight reduction and lipid lowering activities were studied using Spraque-Dawley (SD) rats fed a high fat diet. The rats were raised for four weeks after adaptation period on either a normal diet (ND, based on the AIN-93 diet), high fat diet (HFD, supplemented with 12% lard oil in the ND), or diets containing 10% of freeze dried Doenjang, Chungkukjang, Kochujang, or Samjang to HFD. The final weight, food efficiency ratio (FER) and the weight of adipose tissue were decreased significantly by the consumption of Doenjang and Samjang, compared to HFD (p<0.05). The contents of cholesterol and triglyceride increased by HFD were reduced by the fermented foods in liver and perirenal fat tissues of the rats, especially Doenjang and Samjang diets showed high lipid lowering activity. And TG and cholesterol contents in the plasma serum were simillar trend to liver and perirenal fat tissue. These results suggested that Korean traditional soybean fermented foods, especially Doenjang showed the highest weight reduction and lipid lowering activities of the rats fed high fat diet.

• Journal of Applied Biological Chemistry
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• v.64 no.3
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• pp.291-298
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• 2021

In this study, we investigated whether the combined administration of berberine (BBR) and silibinin (SBN) was effective in improving hyperlipidemia and anti-obesity efficacy using a high-fat diet (HFD)-fed obese mouse model. HFD-induced obese mice were supplemented with the BBR and SBN combination (BBR-SBN) along with the HFD administration for 8 weeks. During the experiment, body weight, food intake, and levels of total cholesterol, triglyceride and high-density lipoprotein (HDL)-cholesterol were analyzed. Consumption of HFD in the mice caused rapid increases in body weight and the levels of total cholesterol and triglycerides compared to the normal control (NC) group. However, supplementation of BBR-SBN in these obese mice significantly reduced body weight gain and suppressed the levels of total cholesterol and triglyceride with the increment of HDL cholesterol level. In the HFD-fed group, abdominal fat weight was significantly increased and the adipocytes within the epididymal adipose tissue were found to have expanded sizes compared to the NC group. However, in the BBR-SBN group, the sizes of the adipocytes were comparable to those of the NC group and abdominal fat weight was significantly reduced. Moreover, the deposition of giant vesicular fat cells in liver tissues seen in the HFD-fed group was considerably reduced in the BBR-SBN group. These results suggest that the BBR-SBN combination tends to have synergic potential as an anti-obesity agent by significantly reducing body weight gain as well as lowering serum lipid levels and thus improving anti-obesity efficacy in HFD-induced obese mice.

• Animal Bioscience
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• v.34 no.4
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• pp.662-669
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• 2021

Objective: Effects of linseed oil (LO) supplementation on the fat content and fatty acid profile of breast meat, and the expression of three genes in the liver, breast muscle and fat tissues of commercial 154-day-old hybrid male turkeys were investigated. Methods: The animals in the control group were fed a commercially available feed and received no LO supplementation (n = 70), whereas animals in the LO group (n = 70) were fed the same basic diet supplemented with LO (day 15 to 21, 0.5%; day 22 to 112, 1%). The effect of dietary LO supplementation on fatty acid composition of breast muscle was examined by gas chromatography, and the expression of fatty acid desaturase 2 (FADS2), peroxisome proliferator activated receptor gamma (PPARγ), and insulin-like growth factor 1 (IGF1) genes was analysed by means of quantitative reverse transcription polymerase chain reaction. Results: The LO supplementation affected the fatty acid composition of breast muscle. Hepatic FADS2 levels were considerably lower (p<0.001), while adipose tissue expression was higher (p<0.05) in the control compared to the LO group. The PPARγ expression was lower (p<0.05), whereas IGF1 was higher (p<0.05) in the fat of control animals. There were no significant (p>0.05) differences in FADS2, PPARγ, and IGF1 gene expressions of breast muscle; however, omega-6/omega-3 ratio of breast muscle substantially decreased (p<0.001) in the LO group compared to control. Conclusion: Fatty acid composition of breast meat was positively influenced by LO supplementation without deterioration of fattening parameters. Remarkably, increased FADS2 expression in the liver of LO supplemented animals was associated with a significantly decreased omega-6/omega-3 ratio, providing a potentially healthier meat product for human consumption. Increased PPARγ expression in fat tissue of the LO group was not associated with fat content of muscle, whereas a decreased IGF1 expression in fat tissue was associated with a trend of decreasing fat content in muscle of the experimental LO group.

• Journal of the Korean Society of Food Culture
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• v.22 no.1
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• pp.157-165
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• 2007

This study was designed to evaluate the effects of fructose(F) or sucrose(S) and guar gum intake on carbohydrate and lipid metabolism in 15-week-old male Goto-Kakizaki(GK) rats. Fifty rats were randomly assigned to 5 groups which were different in carbohydrate(25% of carbohydrate) and fiber(5% w/w) sources. The carbohydrate(CHO) sources of each group were comstarch(control group, 100% of CHO), fructose with cellulose(F), fructose with guar gum(FG), sucrose with cellulose(S), and sucrose with guar gum(SG). Each group was fed exterimental diet for 4 weeks. We measured food intake, body weight gain, adipose tissues weight and organs weight. We conducted oral glucose tolerance test(OGTT) and measured plasma insulin concentration to examine carbohydrate metabolism. To evaluate lipid metabolism, we measured the lipid profile of plasma, liver and feces. Food intake and weight gain of FG or SG groups tended to be less than those of F or S groups. Perirenal and epididymal fat pad weights of SG group were significantly lower than those of S group and those of FG group tended to be lower than those of F group. In OGTT, blood glucose values of F or S groups were significantly higher than those of C group, and FG or SG groups tended to be lower than those of F or S groups during the experimental time. The area under the curve(AUC) of C group was significantly highest among the groups, AUC and plasma insulin concentration of FG or SG groups tended to be lower than those of F or S groups. Plasma and hepatic triglyceride (TG) of FG and SG groups were significantly lower than those of F and S groups, plasma and hepatic total lipid(TL) and total cholesterol(TC) of FG and SG groups tended to be lower than those of F and S groups. Fecal TL, TG and TC of FG or SG groups tended to be higher than those of F and S groups. In conclusion, intake of guar gum should improve carbohydrate and lipid metabolism in partial substitution of fructose or sucrose for cornstarch in GK rats.

• Korean Journal of Exercise Nutrition
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• v.16 no.2
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• pp.65-71
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• 2012

Oxygen is the final acceptor of electron transport from fat and carbohydrate oxidation, which is the rate-limiting factor for cellular ATP production. Under altitude hypoxia condition, energy reliance on anaerobic glycolysis increases to compensate for the shortfall caused by reduced fatty acid oxidation [1]. Therefore, training at altitude is expected to strongly influence the human metabolic system, and has the potential to be designed as a non-pharmacological or recreational intervention regimen for correcting diabetes or related metabolic problems. However, most people cannot accommodate high altitude exposure above 4500 M due to acute mountain sickness (AMS) and insulin resistance corresponding to a increased levels of the stress hormones cortisol and catecholamine [2]. Thus, less stringent conditions were evaluated to determine whether glucose tolerance and insulin sensitivity could be improved by moderate altitude exposure (below 4000 M). In 2003, we and another group in Austria reported that short-term moderate altitude exposure plus endurance-related physical activity significantly improves glucose tolerance (not fasting glucose) in humans [3,4], which is associated with the improvement in the whole-body insulin sensitivity [5]. With daily hiking at an altitude of approximately 4000 M, glucose tolerance can still be improved but fasting glucose was slightly elevated. Individuals vary widely in their response to altitude challenge. In particular, the improvement in glucose tolerance and insulin sensitivity by prolonged altitude hiking activity is not apparent in those individuals with low baseline DHEA-S concentration [6]. In addition, hematopoietic adaptation against altitude hypoxia can also be impaired in individuals with low DHEA-S. In short-lived mammals like rodents, the DHEA-S level is barely detectable since their adrenal cortex does not appear to produce this steroid [7]. In this model, exercise training recovery under prolonged hypoxia exposure (14-15% oxygen, 8 h per day for 6 weeks) can still improve insulin sensitivity, secondary to an effective suppression of adiposity [8]. Genetically obese rats exhibit hyperinsulinemia (sign of insulin resistance) with up-regulated baseline levels of AMP-activated protein kinase and AS160 phosphorylation in skeletal muscle compared to lean rats. After prolonged hypoxia training, this abnormality can be reversed concomitant with an approximately 50% increase in GLUT4 protein expression. Additionally, prolonged moderate hypoxia training results in decreased diffusion distance of muscle fiber (reduced cross-sectional area) without affecting muscle weight. In humans, moderate hypoxia increases postprandial blood distribution towards skeletal muscle during a training recovery. This physiological response plays a role in the redistribution of fuel storage among important energy storage sites and may explain its potent effect on changing body composition. Conclusion: Prolonged moderate altitude hypoxia (rangingfrom 1700 to 2400 M), but not acute high attitude hypoxia (above 4000 M), can effectively improve insulin sensitivity and glucose tolerance for humans and antagonizes the obese phenotype in animals with a genetic defect. In humans, the magnitude of the improvementvaries widely and correlates with baseline plasma DHEA-S levels. Compared to training at sea-level, training at altitude effectively decreases fat mass in parallel with increased muscle mass. This change may be associated with increased perfusion of insulin and fuel towards skeletal muscle that favors muscle competing postprandial fuel in circulation against adipose tissues.

• Applied Microscopy
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• v.32 no.4
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• pp.385-398
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• 2002

The purpose of the present study is to investigate whether stromal cells supporting specific microenvironment for hematopoiesis of bone marrow are affected by toxicants and therapeutic drugs such as antibiotics and anticancer drugs and whether laminin-1 is associated with such effects. SD rats were intraperitoneally injected with 75 mg/kg of cyclophosphamide which is widely used to treat infant's solid tumor, leukemia and myeloma and sacrificed after 3 days, 1 week, 3 weeks or 5 weeks of injection. The bone marrow extracted and paraffin-sectioned was analyzed using immunohistochemical staining. A part of tissues was subjected to electron microscopy following reaction with rabbit anti-laminin antibody, biotinylated goat anti-rabbit IgG conjugated with 12 nm gold particles, and staining with uranyl acetate. 1. The bone marrow tissue at day 3 post injection with cyclophosphamide displayed dilated venous sinus, partial necrotic death, and decreased number of hematopoietic cells. Laminin-1 was intensively stained in the reticular and adipose tissues. 2. Up to 5 weeks post injection, laminin-1 was stained at a low level in the stromal tissue of bone marrow and the number of hematopoietic cell was increased. 3. Deposition of the gold particle which represents laminin-1 expression was observed at the highest level in the stromal cells of bone marrow obtained 3 days after injection, and decreased after 1 to 5 weeks. These results suggest that stromal cells which play a role in supporting microenvironment for bone marrow hematopoiesis augment induction of laminin-1 expression and activation upon administration of cyclophosphamide.

• Journal of Animal Science and Technology
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• v.46 no.6
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• pp.947-956
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• 2004

The primary role of lipoprotein lipase(LPL) is the hydrolysis of triglycerides(TG) from the core of triglyceride-rich lipoproteins such as chylomicrons and very low density lipoproteins in plasma. Fatty acids liberated by LPL on capillary endothelial surfaces are available for tissues as energy sources especially in muscles or for storage in the form of TG in adipose tissues. Therefore, as the candidate gene related to the carcass traits of the beef cattle, we have directly sequenced the exon 5${\sim}$exon 6 region in the bovine LPL gene for discovery of single nucleotide polymorphism(SNP) with 24 unrelated Hanwoo(Korean cattle). Novel eight sequence variants were detected: three loci on exon 5, three on intron 5 and two on exon 6. All SNPs identified were strongly linked each other, and one hundred twenty eight Hanwoo samples were genotyped one SNP on intron 5 using PCR-restriction fragment length polymorphism method by digestion with Hae III restriction enzyme. The allele frequency of the polymorphism was 0.76 and 0.24. The effects of this polymorphism on the breeding values of the carcass weight, loin muscle area, back fat thickness and marbling score were analyzed using least square methods of SAS GLM. The marbling score of BB genotype was significantly higher than those of AA and AB genotypes(P<0.05). This result indicates that this polymorphism may be associated with the variation of marbling score. Further study is warranted to investigate the phenotypic association in Hanwoo.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.5
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• pp.669-676
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• 2010

This study was performed to investigate the effect of Brassica rapa (BR) sprouts on weight reduction and cholesterol-lowering action in rats fed high fat diet for 4 weeks. Weight-matched male Sprague-Dawley rats were assigned to four groups according to dietary fat levels (10% or 20% of diet wt.). Experimental groups were normal diet group (N), high fat diet group (HF), high fat diet with 5% BR sprouts powder group (HF-BRL), and high fat diet with 10% BR sprouts powder group (HF-BRH). The body weight gain was increased in HF group, but gradually decreased to the corresponding level of the N group fed BR sprouts powder. The concentrations of serum LDL-cholesterol, atherogenic index and cardiac risk factor tended to decrease in the BR sprouts powder fed groups compared with the HF group. However, HDL-cholesterol concentration in serum decreased in the HF group and markedly increased in the BR sprouts powder fed groups. Concentrations of triglyceride and total cholesterol in liver were also markedly decreased in the BR sprouts powder fed groups. Triglyceride concentrations of epididymal and mesenteric adipose tissues in the BR sprouts powder fed groups were also decreased compared with the HF group. These results indicate that BR sprouts powder may reduce fat accumulation and body weight, and have cholesterol-lowering effect.

• Journal of Life Science
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• v.16 no.2 s.75
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• pp.231-239
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• 2006

Human mesenchymal stem cells (hMSCs) in bone marrow (BM) can be induced to differentiate into a variety of mesenchymal tissues, including adipocytes, osteoblasts and chondroblasts, under the influence of certain growth or environmental factors. In this study, we analyzed the differentiation process and the associated gene expression profiles inherent to the process by which hMSCs differentiate into osteoblasts. We conducted a comparison of gene expression profiles of the normal human BM MSCs, using human 8K cDNA microarray, incubated in media containing either a combination of $\beta$-glycerol phosphate, L-ascorbic acid, and dexamethasone, or in medium lacking these osteogenic supplements. During the osteoblastic differentiation process, 36 genes were determined to be up-regulated, and 59 genes were shown to be down-regulated. Osteoprotegerin, LRP5, and metallothionein 2A, all of which are associated with the osteogenetic process, were up-regulated, and genes associated with the differentiation of MSCs into other lineages, including muscle, adipose tissue and vascular structure were down-regulated. The set of differentially expressed genes reported in this work should contribute to our current understanding of the processes inherent to the differentiation of MSCs into osteoblasts.