• Title/Summary/Keyword: low-density lipoprotein receptor

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BS21, a combination of Phyllostachys pubescens and Scutellaria baicalensis extracts, reduces adiposity and hyperuricemia in high-fat diet-induced obese mice (죽엽황금복합추출물 BS21의 고지방식이 유도 비만 동물모델에서의 지방생성 및 고요산혈증 개선 효과)

  • Sung, Yoon-Young;Lee, Young-Sil;Kim, Seung-Hyung;Kim, Dong-Seon
    • The Korea Journal of Herbology
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    • v.35 no.5
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    • pp.1-12
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    • 2020
  • Objectives : Phyllostachys pubescens and Scutellaria baicalensis are considered to be effective in promoting blood circulation in traditional medicine. In this study, we examined whether a mixture of P. pubescens leaves and S. baicalensis root (BS21) had any anti-obesity, anti-hyperlipidemia, or anti-hyperuricemia effects and the possible mechanisms of action. Methods : We examined the effects of BS21 in high-fat diet (HFD)-induced obese mice. Mice were fed HFD with BS21 (75, 150, or 300 mg/kg) or Garcinia cambogia extracts (245 mg/kg) as a positive control for 8 weeks. At the end of 8 weeks, body weight, liver and adipose weight, adipocyte size, plasma lipid profiles, adipokine and uric acid levels, and adipose tissue expression levels in obesity and uric acid production-related genes were examined. Results : BS21 decreased body weight gain, white adipose tissue, liver weight, adipocyte size, and liver triglyceride accumulation. It also reduced levels of plasma glucose, triglycerides, non-esterified fatty acids, total cholesterol, low-density lipoprotein cholesterol, alanine transaminase, leptin, and uric acid. In contrast, BS21 increased adiponectin levels. Furthermore, BS21 decreased the expression levels of adipogenesis-related genes, such as peroxisome proliferator-activated receptor γ, sterol regulatory element binding protein-1c, and fatty acid synthase, as well as xanthine oxidoreductase, which is involved in uric acid production. Conclusions : These results suggest that BS21 may exert anti-obesity, anti-hyperlipidemia, and anti-hyperuricemia effects in HFD-induced obese mice by regulating the expression of xanthine oxidoreductase and adipogenesis-related genes.

Apolipoprotein E in Synaptic Plasticity and Alzheimer's Disease: Potential Cellular and Molecular Mechanisms

  • Kim, Jaekwang;Yoon, Hyejin;Basak, Jacob;Kim, Jungsu
    • Molecules and Cells
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    • v.37 no.11
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    • pp.767-776
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    • 2014
  • Alzheimer's disease (AD) is clinically characterized with progressive memory loss and cognitive decline. Synaptic dysfunction is an early pathological feature that occurs prior to neurodegeneration and memory dysfunction. Mounting evidence suggests that aggregation of amyloid-${\alpha}$ ($A{\alpha}$) and hyperphosphorylated tau leads to synaptic deficits and neurodegeneration, thereby to memory loss. Among the established genetic risk factors for AD, the ${\varepsilon}4$ allele of apolipoprotein E (APOE) is the strongest genetic risk factor. We and others previously demonstrated that apoE regulates $A{\alpha}$ aggregation and clearance in an isoform-dependent manner. While the effect of apoE on $A{\alpha}$ may explain how apoE isoforms differentially affect AD pathogenesis, there are also other underexplored pathogenic mechanisms. They include differential effects of apoE on cerebral energy metabolism, neuroinflammation, neurovascular function, neurogenesis, and synaptic plasticity. ApoE is a major carrier of cholesterols that are required for neuronal activity and injury repair in the brain. Although there are a few conflicting findings and the underlying mechanism is still unclear, several lines of studies demonstrated that apoE4 leads to synaptic deficits and impairment in long-term potentiation, memory and cognition. In this review, we summarize current understanding of apoE function in the brain, with a particular emphasis on its role in synaptic plasticity and the underlying cellular and molecular mechanisms, involving low-density lipoprotein receptor-related protein 1 (LRP1), syndecan, and LRP8/ApoER2.

The Structural Studies of Biomimetic Peptides P99 Derived from Apo B-100 by NMR

  • Kim, Gil-Hoon;Won, Ho-Shik
    • Journal of the Korean Magnetic Resonance Society
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    • v.24 no.4
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    • pp.136-142
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    • 2020
  • Apolipoprotein B-100 (apo B-100), the main protein component that makes up LDL (Low density lipoprotein), consists of 4,536 amino acids and serves to combine with the LDL receptor. The oxidized LDL peptides by malondialdehyde (MDA) or acetylation in vivo were act as immunoglobulin (Ig) antigens and peptide groups were classified into 7 peptide groups with subsequent 20 amino acids (P1-P302). The biomimetic peptide P99 (KGTYG LSCQR DPNTG RLNGE) out of B-group peptides carrying the highest value of IgM antigens were selected for structural studies that may provide antigen specificity. Circular Dichroism (CD) spectra were measured for peptide secondary structure in the range of 190-260 nm. Experimental results show that P99 has pseudo α-helice and random coil structure. Homonuclear (COSY, TOCSY, NOESY) 2D-NMR experiments were carried out for NMR signal assignments and structure determination for P99. On the basis of these completely assigned NMR spectra and proton distance information, distance geometry (DG) and molecular dynamic (MD) were carried out to determine the structures of P99. The proposed structure was selected by comparisons between experimental NOE spectra and back-calculated 2D NOE results from determined structure showing acceptable agreement. The total Root-Mean-Square-Deviation (RMSD) value of P99 obtained upon superposition of all atoms were in the set range. The solution state P99 has mixed structure of pseudo α-helix and β-turn(Gln[9] to Thr[13]). These NMR results are well consistent with secondary structure from experimental results of circular dichroism. Structural studies based on NMR may contribute to the prevent oxidation studies of atherosclerosis and observed conformational characteristics of apo B-100 in LDL using monoclonal antibodies.

Effects of black chokeberry on cholesterol metabolism in HepG2 cells (블랙 초크베리가 HepG2세포에서 콜레스테롤 대사에 미치는 효과)

  • Lee, Sang Gil;Kim, Bohkyung
    • Korean Journal of Food Science and Technology
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    • v.54 no.4
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    • pp.398-402
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    • 2022
  • Black chokeberry (Aronia melanocarpa), a rich source of polyphenols, exerts hypocholesterolemic effects. However, little is known about its effects on the regulation of the hepatic cholesterol metabolism and the underlying mechanisms. In the present study, the effects of polyphenol-rich black chokeberry extract (CBE) on hepatic cholesterol metabolism were investigated by measuring the expression of genes involved in the absorption, de novo synthesis, and efflux of cholesterol in HepG2 cells. There was a significant reduction in the expression levels of genes involved in cholesterol metabolism, the low-density lipoprotein receptor, 3-hydroxy-3-methylglutaryl coenzyme A reductase, and sterol regulatory element-binding protein 2, in CBE-treated HepG2 cells. Meanwhile, CBE increased the expression levels of genes involved in cholesterol and bile acid efflux. The expression levels of mitochondrial fatty acid oxidation genes increased, whereas those of lipogenic genes decreased following CBE treatment. These data suggest that the consumption of black chokeberry may be beneficial for the prevention of hypercholesterolemia.

The Structural Studies of Peptide P143 Derived from Apo B-100 by NMR

  • Lee, Ji-Eun;Kim, Gil-Hoon;Won, Ho-Shik
    • Journal of the Korean Magnetic Resonance Society
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    • v.25 no.4
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    • pp.58-63
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    • 2021
  • Apolipoprotein B-100 (apo B-100), the main protein component that makes up LDL (Low density lipoprotein), consists of 4,536 amino acids and serves to combine with the LDL receptor. The oxidized LDL peptides by malondialdehyde (MDA) or acetylation in vivo act as immunoglobulin (Ig) antigens and peptide groups were classified into 7 peptide groups with subsequent 20 amino acids (P1-P302). The biomimetic peptide P143 (IALDD AKINF NEKLS QLQTY) out of C-group peptides carrying the highest value of IgG antigens were selected for structural studies that may provide antigen specificity. Experimental results show that P143 has β-sheet in Ile[1]-Asn[9] and α-helice in Gln[16]-Tyr[20] structure. Homonuclear 2D-NMR (COSY, TOCSY, NOESY) experiments were carried out for NMR signal assignments and structure determination for P143. On the basis of these completely assigned NMR spectra and proton distance information, distance geometry (DG) and molecular dynamic (MD) were carried out to determine the structures of P143. The proposed structure was selected by comparisons between experimental NOE spectra and back-calculated 2D NOE results from determined structure showing acceptable agreement. The total Root-Mean-Square-Deviation (RMSD) value of P143 obtained upon superposition of all atoms were in the set range. The solution state P143 has a mixed structure of pseudo α-helix and β-turn(Phe[10] to Glu[12]). These results are well consistent with calculated structure from experimental data of NOE spectra. Structural studies based on NMR may contribute to the prevent oxidation studies of atherosclerosis and observed conformational characteristics of apo B-100 in LDL using monoclonal antibodies.

Effect of Buddleja officinalis in Diabetic Atherosclerotic Mouse Model Using High Fat Diet (고지방 식이로 유도된 당뇨병성 죽상경화 마우스 모델에서 밀몽화의 효능 연구)

  • Hwang, Sun-Mi;Lee, Yun-Jung;Kim, Eun-Ju;Kim, Hye-Yoom;Li, Xiang;Choi, Yong-Jun;Cho, Nam-Geun;Lee, Ho-Sub;Kang, Dae-Gill
    • The Korea Journal of Herbology
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    • v.24 no.4
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    • pp.55-62
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    • 2009
  • Objectives : This study was designed to investigate the effects of an aqueous extract from Buddleja officinalis Maxim (ABO) on vascular dysfunction in low-density lipoprotein receptor deficient (LDLr KO) mice. Methods : Present study showed that LDLr KO mice were fed a high fat diet consisting of 60 kcal% fat, with or without 200 mg/day/kg ABO of diet, for 14 weeks. Results : High fat diet-LDLr KO mice were treated with ABO were completely normalized by lowering glucose. ABO reduced intima/media thickness in a high fat diet-LDLr KO mice without affecting plasma cholesterol and triglyceride levels. ABO caused endothelium-dependent relaxation in the acetylcholine-precontracted aorta of high fat diet-LDLr KO mice. ABO increased eNOS expression, while decreased cell adhesion molecules expression in high fat diet-LDLr KO mice. Conclusions : In conclusion, chronic treatment with ABO improved hyperglycemia and endothelium-dependent vascular relaxation as well as exhibited anti-inflammatory effect in diabetic atherosclerotic mouse model, independent of effects on plasma lipids.

Trigonella Goenum-Graecum Seed Extract Alleviates Menopausal Symptoms and Osteoporosis in Ovariectomized Rats (호로파(葫蘆巴) 종자 추출물이 난소 절제술을 받은 쥐에서 갱년기 증상 및 골다공증에 미치는 영향)

  • Min Ju Kim;Mi-Rae Shin;Hak Joo Choi;Seong-Soo Roh
    • The Korea Journal of Herbology
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    • v.39 no.3
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    • pp.85-95
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    • 2024
  • Objectives : We proposed the hypothesis that administering Trigonella foenum-graecum seed extract (TSE) could alleviate menopausal symptoms and osteoporosis resulting from estrogen deficiency. Methods : Ovariectomized (OVX) rats were administered TSE at doses of 300 or 600 mg/kg body weight for 8 weeks, followed by measurement of serum lipid profile and serum bone markers using ELISA kits. Additionally, analysis of related genes in the femur and uterus was performed using Western blot and real-time PCR. Additionally, micro-CT analysis was performed to investigate the protective effect of TSE against bone loss due to oophorectomy. Results : The administration of TSE led to significant reductions in triglyceride (TG), total cholesterol (TC), low-density lipoprotein (LDL) cholesterol, and glucose levels in the serum of OVX rats. Furthermore, TSE increased estradiol levels in the serum and notably improved the levels of biochemical markers associated with bone metabolism. Additionally, TSE exerted significant regulatory effects on the mRNA levels of alkaline phosphatase (ALP) and receptor activator of nuclear factor kappa-B ligand (RANKL)-genes closely associated with bone metabolism in the femur. TSE also demonstrated pronounced effects on uterine tissue, with improvements observed in gene expression related to estrogen receptors. Conclusion : Our findings confirm the efficacy of TSE in ameliorating menopause symptoms by modulating elements associated with both bone and lipid metabolism in the serum, uterine tissue, and femur of OVX rats. The present findings suggest that TSE may offer potential therapeutic effects for symptoms related to menopause and osteoporosis in females.

Cryptotanshinone promotes brown fat activity by AMPK activation to inhibit obesity

  • Jie Ni;Aili Ye;Liya Gong;Xiafei Zhao;Sisi Fu;Jieya Guo
    • Nutrition Research and Practice
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    • v.18 no.4
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    • pp.479-497
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    • 2024
  • BACKGROUND/OBJECTIVES: Activating brown adipose tissue (BAT) and browning of white adipose tissue (WAT) can protect against obesity and obesity-related metabolic conditions. Cryptotanshinone (CT) regulates lipid metabolism and significantly ameliorates insulin resistance. Adenosine-5'-monophosphate (AMP)-activated protein kinase (AMPK), a receptor for cellular energy metabolism, is believed to regulate brown fat activity in humans. MATERIALS/METHODS: The in vivo study included high-fat-fed obese mice administered orally 200/400 mg/kg/d CT. They were evaluated through weight measurement, the intraperitoneal glucose tolerance test (IPGTT), intraperitoneal insulin tolerance test (IPITT), cold stimulation test, serum lipid (total cholesterol, triglycerides, and low-density lipoprotein) measurement, hematoxylin and eosin staining, and immunohistochemistry. Furthermore, the in vitro study investigated primary adipose mesenchymal stem cells (MSCs) with incubation of CT and AMPK agonists (acadesine)/inhibitor (Compound C). Cells were evaluated using Oil Red O staining, Alizarin red staining, flow cytometry, and immunofluorescence staining to identify and observe the osteogenic versus adipogenic differentiation. Quantitative real-time polymerase chain reaction and the Western blot were used to observe related gene expression. RESULTS: In the diet-induced obesity mouse model mice CT suppressed body weight, food intake, glucose levels in the IPGTT and IPTT, serum lipids, the volume of adipose tissue, and increased thermogenesis, uncoupling protein 1, and the AMPK pathway expression. In the in vitro study, CT prevented the formation of lipid droplets from MSCs while activating brown genes and the AMPK pathway. AMPK activator enhanced CT's effects, while the AMPK inhibitor reversed the effects of CT. CONCLUSION: CT promotes adipose tissue browning to increase body thermogenesis and reduce obesity by activating the AMPK pathway. This study provides an experimental foundation for the use of CT in obesity treatment.

Association between Genetic Polymorphism of Peroxisome Proliferator-Activated Receptor Alpha Leu162Val and Metabolioc Syndrome in Korean (한국인에서 peroxisome proliferator-activated receptor alpha Leu162Val 유전자 다형성과 대사증후군간의 관련성)

  • Shin Soung-Cheal;Song Hye-Soon;Hong Young-Seoub;Kwak Jong-Young;Yoo Byung-Chul;Lee Yong-Hwan
    • Journal of Life Science
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    • v.16 no.2 s.75
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    • pp.199-205
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    • 2006
  • Peroxisome proliferator activated receptor (PPAR)-$\alpha$ of three PPAR subtypes ($-\alpha,\;-\beta/-\gamma,\;-\delta$), which are members of the nuclear hormone receptor superfamily of ligand-activated transcription factors, plays a key role in lipoprotein and glucose homeostasis. A variation in the PPAR-a gene expression has been suggested to influence the development of metabolic syndrome through alterations in lipid concentrations. The aim of our study was to investigate the association between the PPAR-a and metabolic syndrome among South Korean. A total of 542 health screen examinees were enrolled in this study who were examined in Kosin University Gospel Hospital from December, 2004 to July, 2005. The height, weight, waist circumference, and systolic and diastolic blood pressure of the subjects were examined and fasting blood glucose, total cholesterol, HDL cholesterol, LDL cholesterol, triglyceride were measured by-sampling in venous blood. The metabolic syndrome was defined as the presence of three or more of the following : waist circumference men ${\geq}90cm$, women ${\geq}80cm$, blood pressure ${\geq}130/85mmHg$, fasting glucose ${\geq}110mg/dL$, HDL cholesterol men <40 mg/dL, women <50 mg/dL, triglyceride ${\geq}150mg/dL$. The blood pressure, fasting glucose, HDL cholesterol, triglyceride were evaluated by using the criteria of NECP ATP III and waist circumference was assessed by using the criteria of WHO Asia-Western Pacific. And the author compared the frequency of the PPAR-$\alpha$ mutation of L162V ($C{\rightarrow}G$ variant in exon 5) in a sample of 542 subjects with and without the metabolic syndrome by polymerase chain reaction allele-specific oligonucleotide (PCR-ASO) method. One (0.2%) hetero-isotype among high risk of metabolic syndrome was identified. The values of waist circumference, body mass index and low density lipoprotein cholesterol of the mutant were 100 cm, 28.6 $kg/m^2$ and 120 mg/dL, respectively. Although the author failed to see significant association between the presence of the PPAR-$\alpha$ L162V polymorphism and metabolic syndrome, one PPAR-$\alpha$ L162V polymorphism in metabolic syndrome patients was found.

Vitamin E improves antioxidant status but not lipid metabolism in laying hens fed a aged corn-containing diet

  • Ding, X.M.;Mu, Y.D.;Zhang, K.Y.;Wang, J.P.;Bai, S.P.;Zeng, Q.F.;Peng, H.W.
    • Animal Bioscience
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    • v.34 no.2
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    • pp.276-284
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    • 2021
  • Objective: The objective of this study was to determine whether a dietary vitamin E (VE) supplement could alleviate any detrimental effects of aged corn on lipid metabolism and antioxidant status in laying hens. Methods: The experiment consisted of a 2×3 factorial design with two corn types (normal corn and aged corn (stored for 4 yr) and three concentrations of VE (0, 20, and 100 IU/kg). A total of 216 Lohmann laying hens (50 wk of age) were randomly allocated into six treatment diets for 12 wk. Each treatment had 6 replicates of 6 hens per replicate. Results: The results show that aged corn significantly decreased the content of low-density lipoprotein cholesterol (p<0.05), and reduced chemokine-like receptor 1 (CMKLR1) mRNA expression (p<0.05) in the liver compared to controls. Diet with VE did not alter the content of crude fat and cholesterol (p>0.05), or acetyl-CoA carboxylase, lipoprotein lipase, fatty acid synthase or CMKLR1 mRNA expression (p>0.05) in the liver among treatment groups. Aged corn significantly increased the content of malondialdehyde (MDA) (p<0.05) and decreased superoxide dismutase (SOD) activity (p<0.05) in the liver. The VE increased the content of MDA (p<0.05) but decreased glutathione peroxidase (GSH-Px) activity in serum (p<0.01) and in the ovaries (p<0.05). Adding VE at 20 and 100 IU/kg significantly increased GSH-Px activity (p<0.05) in liver and in serum (p<0.01), 100 IU/kg VE significantly increased SOD activity (p<0.05) in serum. Aged corn had no significant effects on GSH-Px mRNA or SOD mRNA expression (p<0.01) in the liver and ovaries. Addition of 100 IU/kg VE could significantly increase SOD mRNA expression (p<0.01) in the liver and ovary. Conclusion: Aged corn affected lipid metabolism and decreased the antioxidant function of laying hens. Dietary VE supplementation was unable to counteract the negative effects of aged corn on lipid metabolism. However, addition of 100 IU/kg VE prevented aged corninduced lipid peroxidation in the organs of laying hens.