• Title/Summary/Keyword: Receptor protein

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Effect of Acutely Increased Glucose Uptake on Insulin Sensitivity in Rats (단기간의 당섭취 증가가 인슐린 감수성에 미치는 영향)

  • Kim, Yong-Woon;Ma, In-Youl;Lee, Suck-Kang
    • Journal of Yeungnam Medical Science
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    • v.14 no.1
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    • pp.53-66
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    • 1997
  • Insulin resistance is a prominent feature of diabetic state and has heterogeneous nature. However, the pathogenetic sequence of events leading to the emergence of the defect in insulin action remains controversial. It is well-known that prolonged hyperglycemia and hyperinsulinemia are one of the causes of development of insulin resistance, but both hyperglycemia and hyperinsulinemia stimulate glucose uptake in peripheral tissue. Therefore, it is hypothesized that insulin resistance may be generated by a kind of protective mechanism preventing cellular hypertrophy. In this study, to evaluate whether the acutely increased glucose uptake inhibits further glucose transport stimulated by insulin, insulin sensitivity was measured after preloaded glucose infusion for 2 hours at various conditions in rats. And also, to evaluate the mechanism of decreased insulin sensitivity, insulin receptor binding affinity and glucose transporter 4 (GLUT4) protein of plasma membrane of gastrocnemius muscle were assayed after hyperinsulinemic euglycemic clamp studies. Experimental animals were divided into five groups according to conditions of preloaded glucose infusion: group I, basal insulin ($14{\pm}1.9{\mu}U/ml$) and basal glucose ($75{\pm}0.7mg/dl$), by normal saline infusion; group II, normal insulin ($33{\pm}3.8{\mu}U/ml$) and hyperglycemia ($207{\pm}6.3mg/dl$), by somatostatin and glucose infusion; group III, hyperinsulinemia ($134{\pm}34.8{\mu}U/ml$) and hyperglycemia ($204{\pm}4.6mg/dl$), by glucose infusion; group IV, supramaximal insulin ($5006{\pm}396.1{\mu}U/ml$) and euglycemia ($l00{\pm}2.2mg/dl$), by insulin and glucose infusion; group V, supramaximal insulin ($4813{\pm}687.9{\mu}U/ml$) and hyperglycemia ($233{\pm}3.1mg/dl$), by insulin and glucose infusion. Insulin sensitivity was assessed with hyperinsulinemic euglycemic clamp technique. The amounts of preloaded glucose infusion(gm/kg) were $1.88{\pm}0.151$ in group II, $2.69{\pm}0.239$ in group III, $3.54{\pm}0.198$ in group IV, and $4.32{\pm}0.621$ in group V. Disappearance rates of glucose (Rd, mg/kg/min) at steady state of hyperinsulinemic euglycemic clamp studies were $16.9{\pm}3.88$ in group I, $13.5{\pm}1.05$ in group II, $11.2{\pm}1.17$ in group III, $13.2{\pm}2.05$ in group IV, and $10.4{\pm}1.01$ in group V. A negative correlation was observed between amount of preloaded glucose and Rd (r=-0.701, p<0.001) when all studies were combined. Insulin receptor binding affinity and content of GLUT4 were not significantly different in all experimental groups. These results suggest that increased glucose uptake may inhibit further glucose transport and lead to decreased insulin sensitivity.

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Generation of a transgenic mouse model to study cranial suture development; Apert syndrome (두개봉합 발육 연구를 위한 형질변환 쥐의 개발 : 어퍼트 신드롬)

  • Lee, Kee-Joon;Ratisoontorn, Chootima;Baik, Hyoung-Seon;Park, Young-Chel;Park, Kwang-Kyun;Nah, Hyun-Duck
    • The korean journal of orthodontics
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    • v.33 no.6 s.101
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    • pp.485-497
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    • 2003
  • The form and function of the craniofacial structure critically depend on genetic information. With recent advances in the molecular technology, genes that are important for normal growth and morphogenesis of the craniofacial skeleton are being rapidly uncovered, shaping up modem craniofacial biology. One of them is fibroblast growth factor receptor 2 (FGFR2). Specific point mutations in the. FGFR2 gene have been linked to Apert syndrome, which is characterized by premature closure of cranial sutures and craniofacial anomalies as well as limb deformities. To study pathogenic mechanisms underlying craniosynostosis phenotype of Apert syndrome, we used a transgenic approach; an FGFR2 minigene construct containing an Apert mutation (a point mutation that substitute proline at the position 253 to arginine; P253R) was introduced into fertilized mouse germ cells by DNA microinjection. The injected cells were then allowed to develop into transgenic mice. We used a bone-specific promoter (a DNA fragment from the type I collagen gene) to confine the expression of mutant FGFR2 gene to the bone tissue, and asked whether expression of mutant FGFR2 in bone is sufficient to cause the craniosynostosis phenotype in mice. Initial characterization of these mice shows prematurely closed cranial sutures with facial deformities expected from Apert patients. We also demonstrate that the transgene produces mutant FGFR2 protein with increased functional activities. Having this useful mouse model, we now can ask questions regarding the role of FGFR2 in normal and abnormal development of cranial bones and sutures.

Anti-adipogenic Activity of Cortex ulmi pumilae Extract in 3T3-L1 Preadipocytes (유근피 추출물의 3T3-L1지방전구세포의 분화 억제 효능에 관한 연구)

  • Jeong, Hyun Young;Jin, Soojung;Nam, Soo Wan;Hyun, Sook Kyung;Kim, Sung Gu;Kim, Byung Woo;Kwon, Hyun Ju
    • Journal of Life Science
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    • v.24 no.2
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    • pp.137-147
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    • 2014
  • Cortex ulmi pumilae, the cortex of Ulmus davidiana var. japonica, has been used in traditional folk medicine for its anti-inflammatory effect. Although its various bioactivities such as anti-inflammatory, anti-microbial, and anti-cancer, have been reported, the anti-adipogenic activity of cortex ulmi pumilae remains unclarified. In the present study, we investigated the effect of cortex ulmi pumilae extract on adipocyte differentiation in 3T3-L1 preadipocytes. Treatment with cortex ulmi pumilae extract significantly reduced the formation of lipid droplets and triglyceride content in a dose-dependent manner; this is associated with an inhibition of the adipogenic transcription factors, CCAAT/enhancer binding protein ${\alpha}$ ($C/EBP{\alpha}$), $C/EBP{\beta}$, and peroxisome proliferator-activated receptor ${\gamma}$ ($PPAR{\gamma}$). In addition, cortex ulmi pumilae extract treatment during the early stage of adipogenesis showed more efficient anti-adipogenic activity than treatment during other stages of adipogenesis. Cortex ulmi pumilae extract also inhibited cell proliferation and induced G1 arrest of 3T3-L1 cells in the early stage of adipogenesis. This was associated with upregulated expression of Cdk inhibitor p21 and downregulated expression of cyclin E and phospho-Rb, indicating that cortex ulmi pumilae extract blocks mitotic clonal expansion by cell cycle regulation. Taken together, these results suggest that cortex ulmi pumilae extract possesses anti-adipogenic activity through the inhibition of adipocyte differentiation by blocking mitotic clonal expansion.

The Effects of Several Halophytes on Insulin Resistance in Otsuka Long-evans Tokushima Fatty Rats (OLETF 쥐에서 칠면초와 세발나물의 인슐린 저항성 개선 효과)

  • Cho, Jeong-Yong;Huang, Zhangjun;Park, Sun-Young;Park, Kyung-Hee;Pai, Tong-Kun;Kim, So-Young;Kim, Haeng-Ran;Ham, Kyung-Sik
    • Korean Journal of Food Science and Technology
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    • v.46 no.1
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    • pp.100-107
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    • 2014
  • We evaluated preventive effects of Suaeda japonica (SJ) and Spergularia marina Griseb (SMG) on the insulin resistance in Otsuka Long-Evans Tokushima Fatty (OLETF) rats. The 10-week old OLETF rats were fed diets containing 3% (w/w) SJ and SMG for 18 weeks. Fasting blood glucose levels in SJ and SMG groups, measured using the oral glucose tolerance test, were lower than that of the control rats. The SMG group showed significantly lower levels of insulin, glycated hemoglobin, triglyceride, and total cholesterol than the control group. In addition, these levels were relatively lower in the SJ group than those in the control rats. The SJ and SMG groups had relatively lower protein levels of nuclear factor-kappa B (NF-${\kappa}B$) p65 in adipose tissue and serine phosphorylated insulin receptor substrate 1 (IRS-1) in skeletal muscle than the control group. These results suggest that SJ and SMG prevent insulin resistance and SMG in particular reduces blood triglyceride and total cholesterol levels.

Production of Nitric Oxide in Raw 264.7 Macrophages treated with Ganoderan, the ${\beta}-Glucan$ of Ganoderma lucidum (영지의 균사체성 ${\beta}-glucan$에 의한 Raw 264.7 대식세포의 Nitric Oxide생성)

  • Han, Man-Deuk;Lee, Eun-Sook;Kim, Young-Kweon;Lee, June-Woo;Jeong, Hoon;Yoon, Kyung-Ha
    • The Korean Journal of Mycology
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    • v.26 no.2 s.85
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    • pp.246-255
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    • 1998
  • Ganoderan (GAN), an immunomodulating ${\beta}-glucan$ of G. lucidum, induces potent antitumor immunity in tumor-bearing mice. This study was set up to elucidate the ability of macrophage activation of GANs. GAN-treated Raw 264.7 macrophages showed enhanced production of nitric oxide (NO). The ability of GANs to produce NO was based on differences in chemical composition of GANs obtained from the mycelium on various carbon sources and mycelial fractionation. The highest NO production was observed in CW-AS-WS polysaccharide which was extracted from the mycelial wall. GAN-treated Raw 264.7 cells gave a 2-to 5-fold (24 hr) formation of NO levels compared with those treated with medium only. Partial removal of the protein in the extracellular GAN by TCA treatment did appreciably reduce its capacity to secrete NO. The mixture effect of GAN and LPS increased the nitric oxide secretion from RAW 264.7. The cell proliferation of GAN-treated Raw 264.7 cell tines inhibited as compared with its control. Of the culture supernatant of macrophage activated by GAN, the percentage of cytotoxicity against mouse leukemia L1210 cells was slightly dependent on the amount of NO in the culture supernatants of the activated-macrophages. These results indicate that the ${\beta}-glucan-related$ polysaccharides of the higher fungus activate macrophage and release nitric oxide. It also suggests that murine macrophages possess certain receptors for ${\beta}-anomeric$ glucans and play a critical role of ${\beta}-glucan-related$ tumor killing mechanism.

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Studies on the Antibacterial Activity of Enzymatic Hydrolyzates of Lactoferrin Derived from Bovine Colostrum (유우 Lactoferrin 효소가수분해물 항균 활성에 관한 연구)

  • Han, Su Yeon;Kim, Jong Woo
    • Korean Journal of Agricultural Science
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    • v.25 no.1
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    • pp.52-67
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    • 1998
  • The investigative research on the mammalian milk purely consisted of the physiological quality of lactoferrin was conducted to reveal the antimicrobial ativity of specifically functional foods with antibiotic characteristics as a basic data in food manufacturing. Bovine lactoferrin were isolated from raw milk samples, and was digested with pepsin, trypsin and chymotrypsin. It was necessary then to separate and purify lactoferrin from bovine raw milk, and in order to analyze the antimicrobial activity of the enzyme-treated bovine lactoferrin in their required quantitative fraction. Afterwards Escherichia coli and Staphylococcus aureus was incubated in it. It was that investigated to enzyme-treated fractions molecular weight and the peptide fragment with antimicrobial effect. 1. The purity of enzyme-treated bovine lactoferrin(BLF) was tested by SDS-PAGE. As a results of 12% SDS-PAGE assay, pepsin-treated LF did not exhibited band until if reaches 14 KDa, while trypsin and chymotrypsin treated LF, known to contain the non-digestive lactoferrin exhibited band at a molecular weight of 33 KDa. 2. Bovine lactoferrin was sucessfully purified through the use of Sephadex G-50 Column. In order to assay LF through the Sephadex G-50 column chromatography, the digestive bovine lactoferrin (BLFs) was eluted with a linear gradient of 0.05% Tris-HCl. When the gel-filtration analysis, pepsin, trypsin and chymotrypsin treatments of BLF fragments was showed 2, 3, and 2 peak, respectively. The results of the HPLC analysis confirmed that had a non-digestive lactoferrin receptor, and trypsin and chymotrypsin treated BLFs has an antimicrobial effect. 3. To measure the strength of the antimicrobial effect of enzyme treated lactoferrin it was compared to the antimicrobial activity taking place at the incubated Escherichia coli and Staphylococcus aureus. This might explain the resistance of the microorganisms for peptide fragment. The pepsin-treated of bovine lactoferrin was markedly reduced by incubation of the cells. Trypsin-treated of BLF was similar to chymotrypsin-treated of BLF. However, trypsin and chymotrypsin treatments of BLFs were showed the antimicrobial effect until eight hours incubation for native bovine lactoferrin. Therefore the enzyme-treated lactoferrin have an antimicrobial effect even non-digestive lactoferrin. 4. The digestive bovine lactoferrin fragments assay was carried out by the use of Sephadex G-50 column chromatography and SDS-PAGE. The pepsin and chymotrypsin-treated fragments has a low molecular weight and trypsin-treated lactoferrin was only showed a band. It was described that characteristics of digestive protein. It appeared that there may be a relation between virulence and resistance to enzyme-treated BLF.

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Apolipoprotein A1 Inhibits TGF-β1-Induced Epithelial-to-Mesenchymal Transition of Alveolar Epithelial Cells

  • Baek, Ae Rin;Lee, Ji Min;Seo, Hyun Jung;Park, Jong Sook;Lee, June Hyuk;Park, Sung Woo;Jang, An Soo;Kim, Do Jin;Koh, Eun Suk;Uh, Soo Taek;Kim, Yong Hoon;Park, Choon Sik
    • Tuberculosis and Respiratory Diseases
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    • v.79 no.3
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    • pp.143-152
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    • 2016
  • Background: Idiopathic pulmonary fibrosis (IPF) is a progressive and lethal lung disease characterized by the accumulation of excessive fibroblasts and myofibroblasts in the extracellular matrix. The transforming growth factor ${\beta}1$ (TGF-${\beta}1$)-induced epithelial-to-mesenchymal transition (EMT) is thought to be a possible source of fibroblasts/myofibroblasts in IPF lungs. We have previously reported that apolipoprotein A1 (ApoA1) has anti-fibrotic activity in experimental lung fibrosis. In this study, we determine whether ApoA1 modulates TGF-${\beta}1$-induced EMT in experimental lung fibrosis and clarify its mechanism of action. Methods: The A549 alveolar epithelial cell line was treated with TGF-${\beta}1$ with or without ApoA1. Morphological changes and expression of EMT-related markers, including E-cadherin, N-cadherin, and ${\alpha}$-smooth muscle actin were evaluated. Expressions of Smad and non-Smad mediators and TGF-${\beta}1$ receptor type 1 ($T{\beta}RI$) and type 2 ($T{\beta}RII$) were measured. The silica-induced lung fibrosis model was established using ApoA1 overexpressing transgenic mice. Results: TGF-${\beta}1$-treated A549 cells were changed to the mesenchymal morphology with less E-cadherin and more N-cadherin expression. The addition of ApoA1 inhibited the TGF-${\beta}1$-induced change of the EMT phenotype. ApoA1 inhibited the TGF-${\beta}1$-induced increase in the phosphorylation of Smad2 and 3 as well as that of ERK and p38 mitogen-activated protein kinase mediators. In addition, ApoA1 reduced the TGF-${\beta}1$-induced increase in $T{\beta}RI$ and $T{\beta}RII$ expression. In a mouse model of silica-induced lung fibrosis, ApoA1 overexpression reduced the silica-mediated effects, which were increased N-cadherin and decreased E-cadherin expression in the alveolar epithelium. Conclusion: Our data demonstrate that ApoA1 inhibits TGF-${\beta}1$-induced EMT in experimental lung fibrosis.

Human IL-27p28 Gene Polymorphisms are Associated with the Serum Total IgE Levels of Allergic Rhinitis Patients (사람의 IL-27p28 유전자 다형성은 알레르기성 비염 환자 혈청의 IgE 양과 연관됨)

  • Yu, Ji-In;Han, Weon-Cheol;Lee, Jae-Hoon;Kim, Hun-Soo;Yun, Ki-Jung;Lee, Jae-Hoon;Moon, Hyung-Bae;Chae, Soo-Cheon
    • Journal of Life Science
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    • v.19 no.3
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    • pp.299-304
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    • 2009
  • Interleukin 27 (IL-27) was discovered as a heterodimeric cytokine of the IL-12 family, and is composed of two subunits - Epstein-Barr virus induced gene 3 (EBI3) and p28. It acts as a versatile cytokine in the early regulation of Th1 initiation and in the negative regulation of the Th2 factor GATA binding protein 3 (GATA-3). This cytokine is mediated by the IL-27 receptor (WSX-1), which is highly expressed on $CD4^+$ T lymphocytes and NK cells. We previously identified four polymorphisms in the human IL-27p28 gene and suggested that the polymorphism of IL-27p28 is associated with susceptibility to asthma. To determine whether these IL-27p28 SNPs are associated with susceptibility to allergic rhinitis, the genotype and allele frequencies of IL-27p28 SNPs were analyzed between allergic rhinitis patients and healthy controls. Although the genotype and allele frequencies of IL-27p28 SNPs in allergic rhinitis patients were not significantly different from those of the control group, there was a suggestive difference (P=0.037) between these groups in total serum IgE levels in the g.2905T>G SNP of the IL-27p28 gene. Our result implies that the g.2905T>G SNP of the IL-27p28 gene might have an affect on IgE production in allergic rhinitis patients.

Susceptibility Loci Associations with Prostate Cancer Risk in Northern Chinese Men

  • Wang, Na-Na;Xu, Yong;Yang, Kuo;Wei, Dong;Zhang, Yao-Guang;Liu, Ming;Shi, Xiao-Hong;Liang, Si-Ying;Sun, Liang;Zhu, Xiao-Quan;Yang, Yi-Ge;Tang, Lei;Zhao, Cheng-Xiao;Wang, Xin;Chen, Xin;Hui, Juan;Zhang, Yu-Hong;Zhu, Ling;Yang, Fan;Zhang, Yu-Rong;Yang, Ze;Wang, Jian-Ye
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.5
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    • pp.3075-3078
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    • 2013
  • Background: KLK3 gene products, like human prostate-specific antigen (PSA), are important biomarkers in the clinical diagnosis of prostate cancer (PCa). G protein-coupled receptor RFX6, C2orf43 and FOXP4 signaling plays important roles in the development of PCa. However, associations of these genes with PCa in northern Chinese men remain to be detailed. This study aimed to investigate their impact on occurrence and level of malignancy. Methods: All subjects were from Beijing and Tianjin, including 266 cases with prostate cancer and 288 normal individuals as controls. We evaluated associations between clinical covariates (age at diagnosis, prostate specific antigen, Gleason score, tumor stage and aggressive) and 6 candidate PCa risk loci, genotyped by PCR- high resolution melting curve and sequencing methods. Results: Case-control analysis of allelic frequency of PCa associated with PCa showed that one of the 6 candidate risk loci, rs339331 in the RFX6 gene, was associated with reduced risk of prostate cancer (odds ratio (OR) = 0.73, 95% confidence interval (CI) =0.57-0.94, P = 0.013) in northern Chinese men. In addition, subjects with CX (CC+TC) genotypes had a decreased risk for prostrate cancer compared to those carrying the TT homozygote (OR =0.64, 95% CI = 0.45- 0.90, P = 0.008). The TT genotype of 13q22 (rs9600079, T) was associated with tumor stage (P=0.044, OR=2.34, 95% CI=0.94-5.87). Other SNPs were not significantly associated with clinical covariates in prostate cancer (P > 0.05). Conclusions. rs339331 in the RFX6 gene may be associated with prostate cancer as a susceptibility locus in northern Chinese men.

Anti-Lipogenic Effect of Functional Cereal Samples on High Sucrose Diet-Induced Non-Alcoholic Fatty Liver Disease in Mice (고당식이로 유도된 비알코올성 지방간 마우스에서 기능성 잡곡의 지질 대사 개선 효과)

  • Lee, Ko-Eun;Song, Jia-Le;Jeong, Byung-Jin;Jeong, Jong-Sung;Huh, Tae-Gon;Park, Kun-Young
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.45 no.6
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    • pp.789-796
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    • 2016
  • The anti-lipogenic effect of cereal samples on high sucrose diet (HSD)-induced non-alcoholic fatty liver disease (NAFLD) in mice was studied. We divided C57BL/6 mice into various groups based on 8 weeks of treatment with three types of cereal samples (HSD+WR, HSD diet containing 40% white rice; HSD+MCG, HSD diet containing 40% mixed cereal grain; HSD+AO-MCG, HSD diet containing 40% mixed antiobesity-cereal grain). After the experimental period, body weight changes, liver weights, serum lipid profiles, and hepatic fatty acid metabolism-related gene expression levels were determined. We found that HSD+WR, HSD+MCG, and HSD+AO-MCG treatments reduced body weight and liver weight, especially HSD+MCG and HSD+AO-MCG effectively reduced levels of serum triglycerides, total cholesterol, and low-density lipoprotein cholesterol. However, high density lipoprotein cholesterol levels increased compared to the control group. Furthermore, expression of hepatic lipogenic genes such as sterol regulatory element-binding protein-1c, acetyl-coenzyme A carboxylase, fatty acid synthase, stearoyl-coenzyme A desaturase-1, cluster of differentiation, and $PPAR-{\gamma}$ (peroxisome proliferator activated receptor ${\gamma}$) decreased, whereas expression of ${\beta}-oxidation$ genes such as $PPAR-{\alpha}$ and carnitine palmitoyl transferase-1 increased following HSD+MCG and HSD+AO-MCG treatment compared with levels in HSD+WR and control groups. These results suggest that the functional cereal samples, especially HSD+AO-MCG treatment, improved hepatic steatosis triggered by an HSD-induced imbalance in hepatic lipid metabolism.