• Molecules and Cells
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• v.40 no.11
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• pp.864-870
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• 2017

The uncoupling protein 4 (ucp-4) gene is involved in age-dependent neurodegeneration in C. elegans. Therefore, we aimed to investigate the mechanism underlying the association between mitochondrial uncoupling and neurodegeneration by examining the effects of uncoupling agents and ucp-4 overexpression in C. elegans. Treatment with either DNP or CCCP improved neuronal defects in wild type during aging. Uncoupling agents also restored neuronal phenotypes of ucp-4 mutants to those exhibited by wild type, while ucp-4 overexpression attenuated the severity of age-dependent neurodegeneration. Neuronal improvements were further associated with reductions in mitochondrial membrane potentials. However, these age-dependent neuroprotective effects were limited in mitophagy-deficient mutant, pink-1, background. These results suggest that membrane uncoupling can attenuate age-dependent neurodegeneration by stimulating mitophagy.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.8
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• pp.1062-1068
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• 2004

Leptin has a major role in the regulation of food intake and energy homeostasis. In addition, leptin participates in many physiological functions including regulation of lipid metabolism. Bovine recombinant leptin protein was produced in E. coli cells in order to understand function of leptin in the regulation of lipid metabolism. The leptin expression vector was constructed in pGEX-4T-3 vector and transformed into E. coli BL21 cells. Expression of the GST-leptin fusion protein was induced with IPTG. The fusion protein was purified using glutathione sepharose 4B batch method, and the recombinant leptin was eluted after thrombin protease digestion. The effect of leptin on glucose transport was examined in the differentiated adipocytes of 3T3-L1 cells. Leptin had no effect on basal and insulin-stimulated glucose transport in 3T3-L1 cells (p>0.05). Effect of recombinant leptin on glucose and acetate transport was examined in adipose tissues of Korean cattle (Hanwoo). Insulin stimulated glucose transport in both intramuscular and subcutaneous adipose tissues (p<0.05), but leptin did not affect glucose transport in both adipose tissues (p>0.05). Insulin stimulated acetate transport in bovine adipose tissues (p<0.05), but leptin did not affect acetate transport (p>0.05). Northern and RT-PCR analyses showed that mRNA levels of uncoupling protein-2 were increased by leptin treatment in 3T3-L1 cells without statistical difference (p>0.05). In conclusion, bovine recombinant leptin did not affect glucose and acetate transport in both 3T3-L1 adipocytes and bovine adipose tissues, while it stimulates UCP-2 mRNA expression in 3T3-L1 cells.

• Journal of Ginseng Research
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• v.43 no.4
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• pp.589-599
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• 2019

Background: Panax ginseng Meyer is known as a conventional herbal medicine, and ginsenoside Rg1, a steroid glycoside, is one of its components. Although Rg1 has been proved to have an antiobesity effect, the mechanism of this effect and whether it involves adipose browning have not been elucidated. Methods: 3T3-L1 and subcutaneous white adipocytes from mice were used to access the thermogenic effect of Rg1. Adipose mitochondria and uncoupling protein 1 (UCP1) expression were analyzed by immunofluorescence. Protein level and mRNA of UCP1 were also evaluated by Western blotting and realtime polymerase chain reaction, respectively. Results: Rg1 dramatically enhanced expression of brown adipocyte-especific markers, such as UCP1 and fatty acid oxidation genes, including carnitine palmitoyltransferase 1. In addition, it modulated lipid metabolism, activated 5' adenosine monophosphate (AMP)-activated protein kinase, and promoted lipid droplet dispersion. Conclusions: Rg1 increases UCP1 expression and mitochondrial biogenesis in 3T3-L1 and subcutaneous white adipose cells isolated from C57BL/6 mice. We suggest that Rg1 exerts its antiobesity effects by promoting adipocyte browning through activation of the AMP-activated protein kinase pathway.

• Biomolecules & Therapeutics
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• v.4 no.1
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• pp.103-109
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• 1996

To investigate the effect of the third intracellular loop (i3 loop) peptide of human $\beta$$_2$-adrenergic receptor on receptor agonist binding, we expressed third intracellular loop region of human $\beta$$_2$-adrenergic receptor as glutathione S-transferase fusion protein in E. coli. DNA fragment of the receptor gene which encodes amino acid 221-274 of human $\beta$$_2$-adrenergic receptor was amplified by polymerase chain reaction and subcloned into the bacterial fusion protein expression vector pGEX-CS and expressed as a form of glutathione-S-transferase (GST) fusion protein in E. coli DH5$\alpha$. The receptor fusion protein was identified by SDS-PAGE and Western blot using monoclonal anti-GST antibody. The fusion protein expressed in this study was purified to an apparent homogeneity by glutathione Sepharose CL-4B affinity chromatography. The purified i3 loop fusion proteins at a concentration of 10 $\mu\textrm{g}$/ι caused right shift of the isoproterenol competition curve of [$^3$H]Dihydroalprenolol binding to hamster lung $\beta$$_2$-adrenergic receptor indicating lowered affinity of isoproterenol to $\beta$$_2$-adrenergic receptor possibly due to the uncoupling of receptor and G protein in the presence of the fusion protein. The uncoupling of receptor and G protein suggests that i3 loop region plays a critical role on $\beta$$_2$-adrenergic receptor G protein coupling.

• Journal of Life Science
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• v.21 no.1
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• pp.155-158
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• 2011

Uncoupling protein (UCP) 3 has a number of proposed roles in the regulation of fatty acid metabolism. A number of polymorphisms in the human UCP3 gene have been identified, and the correlation with obesity related phenotypes evaluated. The objective of this study was to identify SNP in porcine UCP3 gene and to investigate the effect of the SNP on economic traits. The sequencing analysis method was used to identify nucleotide polymorphisms at position 1405 bp (Genebank accession No : AY739704) in porcine UCP3 gene. The SNP (G150R), located in the exon 3, changed the amino acid to glycine (GGG) from arginine (AGG). This G150R showed three genotypes - GG, GR and RR - by digestion with the restriction enzyme Sma Ⅰ using the PCR-RFLP method. The G150R showed significant effects only on back fat (P<0.05). Animals with the genotype GG had significantly higher back fat thickness (1.358 cm) than animals with the genotype GR (1.288 cm, P<0.05) and RR (1.286 cm, P<0.05). However, the genotypes had no significant association with ADG and days to 90kg. According to results of this study, a G allele of the G150R was found to have a significant effect on back fat thickness. It will be possible to use SNP markers on selected pigs to improve backfat thickness, an important economic trait.

• Preventive Nutrition and Food Science
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• v.10 no.3
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• pp.279-284
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• 2005

Uncoupling protein-1 (UCP-1) plays a major role in thermogenesis, and has been implicated in the pathogenesis of obesity and metabolic disorders. The aim of this study was to estimate the effects of A-3826G polymorphism of UCP-1 gene on body fat distribution. Two hundred forty eight Korean female overweight subjects with BMI more than 25 kgfm2 participated in this study. The areas of abdominal subcutaneous and visceral fat of all subjects were measured from computed tomography cross sectional pictures of the umbilical region. Subcutaneous fat areas of upper and lower thigh were also measured. Body composition was measured by bio-impedance analysis, and serum concentrations of biochemical parameters, such as glucose, triglyceride, cholesterol etc, were also measured. Genotype of UCP-1 was analyzed by polymerase chain reaction (PCR) restriction fragment length polymorphism (RFLP) method. The frequencies of UCP-1 genotypes were AA type; $27.8\%,\;AG\;type;\;51.2\%\;and\;GG\;type;\;21.0\%,$ and the frequency of G allele was 0.47. Body weight, BMI, WHR, SBP, DBP and body compositions were not significantly different by UCP-1 genotype. Abdominal visceral fat area was significantly higher in AG and GG type compared with AA type (p=0.009), but subcutaneous fat areas were not significantly different by UCP-1 genotype. Among biochemical parameters, LDL cholesterol level was significantly higher in GG type compared with AA and AG types (p=0.033). Among all subjects, 121 subjects finished 1 month weight loss program containing hypocaloric diet and exercise. The reduction of body weight and BMI were lower in GG type compared with AA/AG type even though statistical significances were not found (p > 0.05). These results suggest that UCP-1 genotype has a significant effect on visceral fat accumulation among Korean female overweight subjects with BMI more than $25\;kg/m^2$.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.3
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• pp.506-514
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• 2020

Objective: We tested the hypothesis that increasing dietary copper (Cu) to gravid ewes would enhance brown adipose tissue (BAT) thermogenesis in their offspring. Methods: Twin-bearing ewes were assigned on d 70 of gestation to diets containing 3, 10, or 20 ppm dietary Cu (n = 8 per group). Twin lambs were assigned at birth to a cold (6℃) or warm (28℃) environmental chamber for 48 h. Blood was collected from ewes and from lambs and perirenal BAT was collected after 48 h in the environmental chambers. Results: Prenatal Cu exposure increased ewe plasma triiodothyronine (T₃) and thyroxine concentration (T₄) (p<0.01) but prenatal Cu exposure had no effect on lamb plasma concentrations of T₃, T₄, glucose, or nonesterified fatty acid concentration (p≥0.08). The high level of prenatal Cu exposure depressed 48-h rectal temperature (p = 0.03). Cold exposure decreased BAT norepinephrine (NE) and increased BAT dopamine (p≤0.01), but prenatal Cu exposure had no effect on BAT cytochrome C oxidase activity or BAT NE or dopamine (p≥0.07). However, BAT of lambs from high-Cu ewes maintained higher uncoupling protein-1 (UCP1) gene expression than BAT of lambs from low- and medium-Cu ewes following warm or cold exposure in environmental chambers (p = 0.02). Cold exposure caused near depletion of BAT lipid by 48 h (p<0.001), increased BAT cytochrome c oxidase activity (p<0.01), and depressed plasma fatty acid concentrations (p<0.001). Conclusion: Although prenatal Cu exposure increased BAT UCP1 expression during warm and cold exposure, prenatal cold Cu exposure depressed 48-h rectal temperature. Cold exposure decreased BAT lipid content by over 80% and decreased lamb plasma fatty acid concentration by over 40%, indicating that fuel reserves for thermogenesis were nearly depleted by 48 h of cold exposure.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.8
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• pp.1065-1070
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• 2006

The avian uncoupling protein (avUCP) is a member of the mitochondrial transporter superfamily that uncouples proton entry in the mitochondrial matrix from ATP synthesis. The sequencing analysis method was used to identify nucleotide polymorphisms within the avUCP gene in Korean native chicken (KNC). This study identified ten single nucleotide polymorphisms (SNPs) in the avUCP gene. We analyzed the SNPs of the avUCP gene to investigate whether polymorphism in the gene might be responsible for quantitative variations in economic traits in KNC. Three significant polymorphic sites for economic traits were avUCP C+282T (mean body weight, p<0.05), avUCP C+433T (daily percent lay, p<0.05), and avUCP T+1316C (daily percent lay, p<0.05). The frequency of each SNP was 0.125 (C+282T in avUCP gene exon 1 region), 0.150 (C+433T in avUCP gene intron 1 region), and 0.15 (T+1316C in avUCP gene exon 3 region), respectively. Among the identified SNPs, one pair of SNPs (genotype CC, C+282T and TT, avUCP C+433T) showed the highest daily percent lay (p<0.05) and mean body weight (p<0.05) and the frequency was 0.067. This study of the avUCP gene could be useful for genetic studies of this gene and selection on economic traits for KNC.

• Nutritional Sciences
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• v.5 no.1
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• pp.13-19
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• 2002

A mutation in the promoter region of uncoupling protein 3 (UCF3), specifically the -55C longrightarrow T transition, may influence an individual's energy metabolism and body weight. The objective of this study was to investigate the effect of a weight reduction program on endocrine functions and body fat distribution, related to UCP3 promoter genotype. Ninety overweight pre-menopausal female subjects participated in the weight reduction program at Yonsei University Hospital, and were placed on a calorie-restricted diet (300 kcal less than their daily requirements) for 12 weeks. After 12 weeks, all subjects on the program lost approximately 5% of their initial body weights and had lower Body Mass Index (BMI) values. Among the 90 women, 56 had a normal (without mutation) UCP3 genotype, while 34 women had mutations in the promoter region of UCP3. Despite similar weight reductions in both groups, a significantly higher decrease in abdominal adipose tissue was observed in the normal UCP3 genotype group, compared to the group with mutations. In particular, there was a significant reduction of fat at the lumbar 1 (Ll) level in the without-mutation group. Serum levels of total cholesterol, apolipoprotein Al were significantly decreased in the without-mutation group, by 4.4% and 5.7% respectively. Serum levels of hormones were not significantly changed in both groups artier the intervention. However, in the group without the mutations, the leptin level significantly reduced by 23.4% (p<0.001). Serum free fatty acid (FFA) concentration was significantly increased in the group with mutation following the weight reduction program. On the other hand, FFA responses were shown similar increases in both groups. In conclusion, although no difference was found in the magnitude of weight reduction in both groups, there were significant differences in body fat distribution and in endocrine function between the groups.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.2
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• pp.170-175
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• 2019

Objective: Uncoupling protein 3 gene (UCP3) is a candidate gene associated with the meat quality of pigs. The aim of this study was to explore the regulation mechanism of UCP3 expression and provide a theoretical basis for the research of the function of porcine UCP3 gene in meat quality. Methods: Bisulfite sequencing polymerase chain reaction (PCR) and quantitative real-time PCR (Q-PCR) were used to analyze the methylation of UCP3 5′-flanking region and UCP3 mRNA expression in the adipose tissue or skeletal muscle of three pig breeds at different ages (1, 90, 210-day-old Putian Black pig; 90-day-old Duroc; and 90-day-old Dupu). Results: Results showed that two cytosine-guanine dinucleotide (CpG) islands are present in the promoter region of porcine UCP3 gene. The second CpG island located in the core promoter region contained 9 CpG sites. The methylation level of CpG island 2 was lower in the adipose tissue and skeletal muscle of 90-day-old Putian Black pigs compared with 1-day-old and 210-day-old Putian Black pigs, and the difference also existed in the skeletal muscle among the three 90-day-old pig breeds. Furthermore, the obvious changing difference of UCP3 mRNA expression was observed in the skeletal muscle of different groups. However, the difference of methylation status and expression level of UCP3 gene was not significant in the adipose tissue. Conclusion: Our data indicate that UCP3 mRNA expression level was associated with the methylation status of UCP3 promoter in the skeletal muscle of pigs.