• Asian-Australasian Journal of Animal Sciences
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• 제6권3호
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• pp.339-342
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• 1993

This influence of dietary medium chain triglyceride on liver protein synthesis in chicks was investigated using a large dose injection of $L-[4-^3H]$ phenylalanine. Dietary medium chain triglyceride increased liver weight and liver fat content of chicks compared to the long chain triglyceride group. Fractional synthesis rate of liver protein was increased by dietary medium chain triglyceride, which was accounted for not by elevating protein synthesized per unit RNA but by enhancing RNA: protein ratio.

• Journal of Nutrition and Health
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• 제27권9호
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• pp.910-923
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• 1994

The effects of individual fatty acids, differing in their degree of unsaturation(18:0, 18:1, 18:2 and 18:3) on the biosynthesis and secretion and lipids were investigated in Hep-G2 cells. Synthesis of apolipoprotein was measured by the incorporation of 3H-leucine into apolipoprotein(d<1.21g/ml) and synthesis of lipids was measured by the incorporation of 3H-glycerol and 14C-acetate into various lipid classes. Inclusion of 1.0mM of each fatty acids into the culture medium significantly increased the synthesis of total apolipoprotein and Apo B(p<0.05). However, addition of fatty acid did not affect the synthesis of cellular and medium protein. Among different fatty acids tested, oleic acid had the greatest effect on Apo B synthesis. While stearic, linoleic and linolenic acid, all had similar effects. The secretion of triglyceride into the medium markedly increased in all fatty acid groups being 5-6 times over the albumin control. The triglyceride secretion was the highest int he oleic acid group. The secretion of phospholipid and cholesterol also increased with triglyceride output. A positive relationship existed between the output of lipoprotein-triglyceride and Apo B. Since the synthesis of Apo B was significantly increased when various fatty acids were included into the culture medium, part of the apparently stimulated synthesis of the apolipoprotein may be in response to the increased formation and secretion of lipoprotein lipids.

• 한국식품과학회지
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• 제51권6호
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• pp.558-564
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• 2019

Hypertriglyceridemia is one of the metabolic syndrome that is often observed as a result of lipid abnormalities. It is associated with other lipids, metabolic disorders, cardiovascular disease and liver disease. Korean red ginseng is known to affect obesity, dyslipidemia, liver disease and liver function, but the mechanism of its effect is not clear. This study examined the beneficial effects of hypertriglyceridemia and the mechanism of action of Jinan red ginseng extract (JRG) in hepatoma cells. To measure the levels of triglyceride accumulation, we studied the expression of proteins and mRNAs related to lipidogenesis in hepatoma cells (Huh7 and HepG2). JRG decreases the lipidogenic markers, peroxisome proliferator-activated receptor γ (PPARγ), CCAAT-enhancer-binding proteins α (C/EBPα) and C/EBPβ which are major regulators of triglyceride synthesis in hepatoma cells. We also found that JRG reduced sterol regulatory element binding proteins 1c (SREBP-1c), C/EBPα and C/EBPβ by regulating liver X receptor (LXR) and stearoyl CoA desaturase (SCD) expressions. In addition, the first-limited step of synthesis triglyceride (TG), glycerol-3-phosphate (G3P) is decreased by JRG. These results suggest that the anti-hypertriglyceride effect of JRG in hepatoma cells could be accompanied with the inhibition of lipidogenic transcription factors by regulating LXR and SCD expression.

• Journal of Microbiology and Biotechnology
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• 제23권11호
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• pp.1569-1576
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• 2013

In mice, supplementation of t10,c12 conjugated linoleic acid (CLA) increases liver mass and hepatic steatosis via increasing uptake of fatty acids released from adipose tissues. However, the effects of t10,c12 CLA on hepatic lipid synthesis and the associated mechanisms are largely unknown. Thus, we tested the hypothesis that gut microbiota-producing t10,c12 CLA would induce de novo lipogenesis and triglyceride (TG) synthesis in HepG2 cells, promoting lipid accumulation. It was found that treatment with t10,c12 CLA ($100{\mu}M$) for 72 h increased neutral lipid accumulation via enhanced incorporation of acetate, palmitate, oleate, and 2-deoxyglucose into TG. Furthermore, treatment with t10,c12 CLA led to increased mRNA expression and protein levels of lipogenic genes including SREBP1, ACC1, FASN, ELOVL6, GPAT1, and DGAT1, presenting potential mechanisms by which CLA may increase lipid deposition. Most strikingly, t10,c12 CLA treatment for 3 h increased phosphorylation of mTOR, S6K, and S6. Taken together, gut microbiota-producing t10,c12 CLA activates hepatic de novo lipogenesis and TG synthesis through activation of the mTOR/SREBP1 pathway, with consequent lipid accumulation in HepG2 cells.

• 생명과학회지
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• 제6권3호
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• pp.159-164
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• 1996

Effects of 1% dietary orotic acid on triglyceride metabolism were examined in SD-rats and Kud: ddY mice. When rats were fed semisynthetic diet containing 1% orotic acid and n-6 polyunsaturated fatty acid (linoleic acid), the hepared diet. In contrast to rats which respond to orotic acid consumption with increases in hepatic triglyceride content, mice did not so respond. The rats-limiting step in triglyceride synthesis is catalyzed by the enzyme phosphatic acid phosphohydrolase (EC3.1.3.4) which is present in the liver cytosol and microsomes of rats fed oroic acid diet. This finding suggests that the activity of this enzyme may play a tole in the fatty liver formation in rats.

• 생명과학회지
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• 제15권4호
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• pp.613-618
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• 2005

치커리 수용성 추출물을 $2\%$ 및 $4\%$ 수준으로 첨가한 식이를 Sprague-Dawle계 흰쥐에 2주간 투여하여 중성지질 대사에 미치는 영향을 검토하였다. 혈청 중성지질 농도는 대조군에 비해 치커리 추출물 투여군에서 현저히 감소하였다. Apolipoprotein B-함유 lipoprotein의 합성 및 분비에 필수적인 간장 microsomal triglyceride transfer protein (MTP)활성도 치커리 투여군에서 현저히 감소하였다. 간 조직에서 중성지질 합성의 중요 조절효소로 알려진 phosphatidate phosphohydrolase (PAP) 활성은 각 실험군간에 큰 차이는 없었다. 또한 혈청 및 간 조직의 콜레스테롤, 인지질, 유리지방산 농도도 각 실험군간에 유의적인 차이는 없었다. 이상의 실험결과에서 치커리 수용성 추출물 $2\%$ 및 $4\%$ 첨가는 간 조직에서 혈중으로 분비하는데 중요한 역할을 하는 MTP활성의 감소가 혈청중성지질 농도의 감소에 영향을 미치는 중요한 요인으로 사료되었다.

• Asian-Australasian Journal of Animal Sciences
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• 제28권1호
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• pp.127-134
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• 2015

Castration induces the accumulation of body fat and deposition of intramuscular fat in Korean cattle, resulting in improved beef quality. However, little is known about the metabolic adaptations in the liver following castration. To understand changes in lipid metabolism following castration, hepatic expression levels of lipid metabolism genes were compared between Korean bulls and steers. Steers had higher (p<0.001) hepatic lipids contents and higher (p<0.01) mRNA levels of lipogenic acetyl-CoA carboxylase. This differential gene expression may, in part, contribute to increased hepatic lipid content following the castration of bulls. However, we found no differences in the hepatic expression levels of genes related to triglyceride synthesis (mitochondrial glycerol-3-phosphate acyltransferase, diacylglycerol O-acyltransferase 1 and 2) and fatty acid (FA) oxidation (carnitine palmitoyltransferase 1A, C-4 to C-12 straight chain acyl-CoA dehydrogenase, very long chain acyl-CoA dehydrogenase) between bulls and steers. No differences in gene expression for very-low-density lipoprotein (VLDL) secretion, including apolipoprotein B mRNA and microsomal triglyceride transfer protein (MTTP) protein, were observed in the liver although MTTP mRNA levels were higher in steers compared to bulls. In conclusion, FA synthesis may contribute to increased hepatic lipid deposition in steers following castration. However, hepatic lipid metabolism, including triglyceride synthesis, FA oxidation, and VLDL secretion, was not significantly altered by castration. Our results suggest that hepatic lipid metabolism does not significantly contribute to increased body fat deposition in steers following castration.

• 생명과학회지
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• 제32권12호
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• pp.962-970
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• 2022

비알코올성 지방간염(nonalcoholic steatohepatitis, NASH)은 비알코올성 지방간 질환(nonalcoholic fatty liver disease, NAFLD)의 진행질환으로, 중성지방 침착, 염증 및 간 섬유화가 동반되어 간경변증과 간암의 원인이 되는 질환이나, 아직까지 비알코올성 지방간염을 치료하는 뚜렷한 치료제가 없는 실정이다. Poricoic acid (PoA)는 복령의 약효성분으로 여러 약리작용이 보고되었으나 비알코올성 지방간염의 치료 효능은 보고되지 않았다. 따라서 본 연구에서는 PoA가 비알코올성 지방간염의 병인에 작용하여 비알코올성 지방간염을 억제하는지를 in vivo 및 in vitro 연구를 통해 확인하였다. 비알코올성 지방간염을 유도하는 식이(high fat and methionine-choline deficient diet, HFMCD)로 비알코올성 지방간염을 유발한 쥐에서 PoA는 HFMCD에 의해 증가된 간 무게를 감소시켰으며, 간 독성을 나타내는 alanine aminotransferase, aspartate aminotransferase도 감소시켰다. Oil Red O 염색 및 hematoxylin & eosin 염색의 결과에 의하면, PoA는 HFMCD에 증가하는 간 조직 내 중성지방의 생성을 감소시켰으며, qPCR 결과에 의해서도 PoA는 중성 지방 합성과 관련된 유전자들의 발현도 감소시켰다. 또한 간 조직에서 CD68 면역 염색 결과에 의하면, PoA는 HFMCD에 의해 증가는 CD68 면역 염색을 감소시켰으며, 염증과 관련된 유전자 발현도 감소시켰다. 더욱이 Sirius red 염색과 α-smooth muscle actin (α-SMA) 면역 염색으로 간 섬유화 정도를 측정한 결과, PoA는 HFMCD에 증가되는 sirius red 염색과 α-SMA 면역 염색을 유의적으로 감소시켰으며 섬유화 관련 유전자들의 발현도 감소시켰다. 또한, PoA는 palmitate (Pa)로 처리한 간세포 AML12에서 Pa에 의해 증가하는 중성 지방산 합성, 염증 및 섬유화 관련 유전자들의 발현을 감소시켰다. 이상의 결과를 종합하면 PoA는 비알코올성 지방간염의 중요 병인인 중성지방 생성, 염증 및 섬유화를 억제하여 비알코올성 지방간염을 억제함을 확인하였다.

• 한국식품과학회지
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• 제33권4호
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• pp.492-496
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• 2001

혈청 중성지질 저하작용을 가지고 있는 것으로 알려진 OA식 및 DEHP식을 각각 투여한 흰쥐의 간장 및 소장에서 MTP 활성과 mRNA 수준을 검토하였다. 간장 중성지질 농도는 대조군에 비교해서 OA군에서 유의하게 증가하였으나, DEHP군에서는 유의한 차이가 없었다. 혈청 중성지질 농도는 대조군에 비해서 OA군 및 DEHP군에서 유의하게 감소하였는데, 이러한 저하는 OA군에서 더욱 현저하였다. 간세포에서의 MTP 활성과 mRNA 수준은 대조군에 비해서 OA군에서 유의하게 저하하였으나, 소장에서의 MTP 활성은 증가하였다. 그러나, 간장 및 소장의 MTP 활성과 mRNA 수준은 대조군과 DEHP군 사이에서는 유의적인 변화가 없었다. 간장에 있어서 중성지질 합성의 중요 조절효소인 microsomal PAP 활성은 대조군에 비해 OA군에서 유의하게 증가하였으나, DEHP군에서는 cytosolic PAP 활성이 감소하였다. 이상의 결과로부터, OA에 의한 혈청 중성지질 저하 작용에는 간장 MTP 활성과 mRNA 유전자 발현이 깊이 관여하였으나, DEHP에 의한 혈청 중성지질 저하 작용에는 MTP 대사와는 무관한 것으로 사료되었다.

• Asian-Australasian Journal of Animal Sciences
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• 제15권12호
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• pp.1760-1764
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• 2002

In order to elucidate the physiological function of circulating IGF-I on muscle protein synthesis in the chicken under malnutritional conditions, we administrated recombinant chicken IGF-I using a osmotic mini pump to fasted young chickens and measured the rate of muscle protein synthesis and plasma metabolite. The pumps delivered IGF-I at the rate of $22{\mu}g/d\{300{\mu}g{\cdot}(kg\;body\;weight{\cdot}d)^{-1}\}$. Fractional rate of protein synthesis in the muscle was measured using a large dose injection of L-[$2,6-^3H$]phenylalanine. Constant infusion of chicken IGF-I did not affect plasma glucose level. Significant interaction between dietary treatment and IGF-I infusion was observed in plasma NEFA and total cholesterol concentrations. When chicks were fasted, IGF-I infusion decreased plasma NEFA and total cholesterol concentrations. On the other hand, IGF-I administration did not affect plasma levels of both metabolites. Fasting reduced plasma triglyceride concentration significantly. IGF-I infusion also decreased the level of plasma triglyceride. Plasma IGF-I concentration of young chickens was halved by fasting for 1 d. IGF-I infusion using an osmotic minipump for 1 d increased plasma IGF-I concentration in fasted chicks to the level of fed chicks. Fasting decreased body weight and the loss of body weight was significantly ameliorated by IGF-I infusion. There was a significant interaction between dietary treatment and IGF-I infusion in the fractional rate of breast muscle protein synthesis. There was no effect of IGF-I infusion on muscle protein synthesis in fed chicks. Muscle protein synthesis reduced by fasting was ameliorated by IGF-I infusion, but did not reach to the level of fed control. Muscle weight of fasted chicks infused with IGF-I was similar to fasted birds without IGF-I infusion, which suggests that muscle protein degradation would be increased by IGF-I infusion as well as protein synthesis in fasted chicks.