• BMB Reports
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• v.40 no.6
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• pp.921-927
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• 2007

UCP2 and UCP3 are members of the uncoupling protein family, which may play roles in energy homeostasis. In order to determine the regulation of the predominant expression of UCP3 in skeletal muscle, the effects of differentiation and myogenic regulatory factors on the promoter activities of the mouse UCP2 and UCP3 genes were studied. Reporter plasmids, containing approximately 3 kb of the 5'-upstream region of the mouse UCP2 and UCP3 genes, were transfected into C2C12 myoblasts, which were then induced to differentiate. Differentiation positively induced the reporter expression about 20-fold via the UCP3 promoter, but by only 2-fold via the UCP2 promoter. C2C12 myoblasts were cotransfected with expression vectors for myogenin and/or MyoD as well as reporter constructs. The simultaneous expression of myogenin and MyoD caused an additional 20-fold increase in the reporter expression via the UCP3 promoter, but only a weak effect via the UCP2 promoter. In L6 myoblasts, only MyoD activated the UCP3 promoter, but in 3T3-L1 cells neither factor activated the UCP3 promoter, indicating that additional cofactors are required, which are present only in C2C12 myoblasts. The expression of UCP2 and UCP3 is differentially regulated during muscle differentiation due to the different responsiveness of their promoter regions to myogenin and MyoD.

• Molecules and Cells
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• v.38 no.7
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• pp.657-662
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• 2015

Rapid and efficient engulfment of apoptotic cells is an essential property of phagocytes for removal of the large number of apoptotic cells generated in multicellular organisms. To achieve this, phagocytes need to be able to continuously uptake apoptotic cells. It was recently reported that uncoupling protein 2 (Ucp2) promotes engulfment of apoptotic cells by increasing the phagocytic capacity, thereby allowing cells to continuously ingest apoptotic cells. However, the functions of Ucp2, beyond its possible role in dissipating the mitochondrial membrane potential, that contribute to elevation of the phagocytic capacity have not been determined. Here, we report that the anion transfer or nucleotide binding activity of Ucp2, as well as its dissipation of the mitochondrial membrane potential, is necessary for Ucp2-mediated engulfment of apoptotic cells. To study these properties, we generated Ucp2 mutations that affected three different functions of Ucp2, namely, dissipation of the mitochondrial membrane potential, transfer of anions, and binding of purine nucleotides. Mutations of Ucp2 that affected the proton leak did not enhance the engulfment of apoptotic cells. Although anion transfer and nucleotide binding mutations did not affect the mitochondrial membrane potential, they exerted a dominant-negative effect on Ucp2-mediated engulfment. Furthermore, none of our Ucp2 mutations increased the phagocytic capacity. We conclude that dissipation of the proton gradient by Ucp2 is not the only determinant of the phagocytic capacity and that anion transfer or nucleotide binding by Ucp2 is also essential for Ucp2-mediated engulfment of apoptotic cells.

• The Korean Journal of Food And Nutrition
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• v.30 no.3
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• pp.531-538
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• 2017

This study was performed to investigate the effects of garlic on uncoupling protein 2 (UCP2) transcriptional regulation of UCP2-luciferase transgenic mice fed on a high fat diet to induce obesity. To examine the transcriptional regulation of UCP2, we generated transgenic mice with a UCP2 promoter (-1,830/+30 bp) containing luciferase as a reporter gene. UCP2-luciferase transgenic mice were fed a 45% high-fat diet for 8 weeks to induce obesity. Subsequently, mice were maintained on either a high-fat control diet (TG-CON), or high-fat diets supplemented with 2% (TG-GL2) or 5% (TG-GL5) garlic for a further 8 weeks. Dietary garlic reduced body weight and energy efficiency ratio in the TG-GL5 group, compared to the TG-CON group. Furthermore, garlic supplementation significantly decreased white adipose tissue fat mass and plasma levels of triglycerides, total cholesterol, and leptin in the TG-GL2 and TG-GL5 groups, compared to the TG-CON group. Specifically, UCP2 promoter activity in metabolic tissues such as liver, white adipose tissue, brown adipose tissue, and skeletal muscle was increased by garlic supplementation. These results suggest that dietary garlic was partially associated with an increase of UCP2 transcriptional activity in metabolic tissues for decreasing obesity.

• Journal of Marine Life Science
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• v.8 no.2
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• pp.186-189
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• 2023

Uncoupling protein 1 (UCP1) is a unique mitochondrial membranous protein expressed in brown adipose tissue (BAT) in mammals. While its expression in response to cold temperatures and adipogenic inducers is well-characterized in mammals and human infants, the molecular characterization and expression of UCP1 in fish remain unexplored. To address this gap, we analyzed UCP1 expression in response to adipogenic inducers in a fish cell line, rainbow trout gonadal cells (RTG-2), and compared it with UCP1 expression in three mammalian preadipocytes, 3T3-L1, T37i, and WT1 exposed to the Peroxisome proliferator-activated receptor gamma (PPARγ) agonists, rosiglitazone (Rosi). In mammalian preadipocytes, UCP1 protein was highly expressed by Rosi, with an induction of adipogenesis observed in a time-dependent manner. This suggests that UCP1 plays a significant role in adipogenesis in mammals. However, RTG-2 cells showed no response to adipogenic inducers and exhibited only marginal expressions of UCP1. These results imply that RTG-2 cells may lack crucial responsive mechanisms to adipogenic signals or that the adipogenic response is regulated by other mechanisms. Further studies are needed to confirm these phenomena in fish preadipocytes when an appropriate cell line is established in future research.

• Journal of Korean Medicine for Obesity Research
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• v.6 no.2
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• pp.59-73
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• 2006

Objectives: This study was conducted to investigate the effects of Uncoupling protein (UCP) polymorphisms on weight loss. We analyzed associations between polymorphisms of UCP-2, 3 and changes in percentage of obesity phenotypes (Body mass index and percent body fat) after treatment. Materials and Methods: A total of 207 Korean women (BMI over 25) were recruited from the obesity clinic in Kirin Oriental Medical Hospital (Seoul, Korea). All patients were treated with a very low calorie diet and oriental medical therapy for one month. The effect of UCP polymorphisms on changes in obesity-phenotypes were analyzed. For the genotyping of a single nucleotide polymorphism (SNPs), genomic DNA from each subject was extracted from whole blood and genotyped using the TaqMan Method. Associations between changes in percentage of obesity phenotypes (BMI and percent body fat) and UCP polymorphisms were analyzed using age-adjusted general linear model. Results and Conclusions: In this study, AG, GG type of UCP-2 -866A>G, CC, CT type of UCP-2 +4787C>T, CG, GG type of UCP-3 +2564C>G, AG, GG type of UCP-3 +3106A>G, and TC, CC type of UCP-3 +4589T>C played a role as a resistance gene to weight loss.

• Biomedical Science Letters
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• v.14 no.4
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• pp.239-242
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• 2008

Obesity results from a combination of genetic, environmental, and behavioral factors. Uncoupling proteins (UCP) are members of the larger family of mitochondrial anion carrier proteins (MACP). UCP separates oxidative phosphorylation from ATP synthesis with energy dissipated as heat, also referred to as the mitochondrial proton leak. UCP facilitates the transfer of anions from the inner to the outer mitochondrial membrane and the return transfer of protons from the outer to the inner mitochondrial membrane. Therefore, we investigated the genotype for the G>A polymorphism at the position -866 of UCP2 gene in Koreans and compared genotype of patients with control group. 50 patients (Male 22, Female 28), who previously underwent type 2 diabetcs (T2DM) and 30 controls (Male 14, Female 16) participated in this study. There was a weak significant association between -866 G>A polymorphism in UCP2 gene and T2DM. The present study shows that UCP2 -866 G>A polymorphism may not be associated with the pathogenesis of T2DM as opposed to the previous reports in other countries. Further studies with larger population may be needed for the development of diagnostic methods at genetic level such as DNA chip.

• BMB Reports
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• v.55 no.10
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• pp.500-505
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• 2022

Uncoupling protein 2 (Ucp2) was first introduced as a member of Uncoupling protein family and a regulator of ROS formation; however, its role in adipose tissue is not fully understood. In the present study, we have investigated the role of Ucp2 against high-fat diet (HFD)-induced obesity in epididymal white adipose tissue (eWAT) and browning of inguinal white adipose tissue (iWAT). Diet-induced obesity is closely related to macrophage infiltration and the secretion of pro-inflammatory cytokines. Macrophages surround adipocytes and form a crown-like-structure (CLS). Some reports have suggested that CLS formation requires adipocyte apoptosis. After 12 weeks of HFD challenge, Ucp2 knockout (KO) mice maintained relatively lean phenotypes compared to wild-type (WT) mice. In eWAT, macrophage infiltration, CLS formation, and inflammatory cytokines were reduced in HFD KO mice compared to HFD WT mice. Surprisingly, we found that apoptotic signals were also reduced in the Ucp2 KO mice. Our study suggests that Ucp2 deficiency may prevent diet-induced obesity by regulating adipocyte apoptosis. However, Ucp2 deficiency did not affect the browning capacity of iWAT.

• Journal of Aquaculture
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• v.17 no.1
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• pp.1-7
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• 2004

A rainbow trout uncoupling protein 3 (UCP3) cDNA clone, encoding a 310 amino acid protein, was cloned and sequenced from a liver cDNA library. Two different splice variants designated UCP3-vl and UCP3-v2, were identified through liver cDNA library screening using rainbow trout UCP3 cDNA clone as a probe. UCP3-vl has 3 insertions in the UCP3 cDNA: the first insertion (133 bp), the second (141 bp), and the third (370 bp) were located 126 bp, 334 bp and 532 bp downstream from the start codon, respectively. UCP3-v2 contained a single insertion, identical in sequence and location to the second insertion of UCP3-vl. UCP3, a mitochondrial protein, functions to modulate the efficiency of oxidative phosphorylation. UCP3 has been detected from heart, testis, spinal cord, eye, retina, colon, muscle, brown adipose tissue and white adipose tissue in mammalian animals. Human and rodent UCP3s are highly expressed in skeletal muscle and brown adipose tissue, while they show weak expression of UCP3 in heart and white adipose tissue. In contrast to mammalian studies, RT-PCR and Southern blot analysis of the rainbow trout demonstrated that UCP3 is strongly expressed in liver and heart. UCP3, UCP3-vl, and UCP3-v2 all contain an Ava III short interspersed element (SINE), located in the 3'untraslated region (UTR). PCR using primers from the Ava III SINE and the UCP3 3'UTR region indicates that the UCP3 cDNA is structurally conserved among salmonids and that these primers may be useful for salmonid species genotyping.

• Journal of Korean Medicine for Obesity Research
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• v.6 no.1
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• pp.81-92
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• 2006

Objectives : Recent studies have provided some clues with regard to the relationship existing between uncoupling proteins (UCPs) and blood pressure in animal experiments. In an attempt to determine the genetic polymorphisms of UCPs that are associated with blood pressure in humans, we have analyzed genetic polymorphisms in members of the UCP family, including UCP1, UCP2 and UCP3. Methods : In this study, we assessed the association between UCP genotypes and systolic blood pressure (SBP) and diastolic blood pressure (DBP), in a population comprised of 832 Korean female subjects, using a general linear model, which was adjusted for both age and BMI. Results : Among 14 SNPs and the haplotypes constructed from them, haplotype3 of UCP1 (UCP1-ht3) evidenced significant associations with SBP (P=0.0053) and DBP (P=0.0130). However, this haplotype was not significantly associated with obesity phenotypes, including BMI or fat mass (P>0.05), thereby suggesting that its association with blood pressure was not mediated by obesity phenotypes. Conclusions : The source of variations in SBP were determined to occur in the following order: BMI (12.8 %), age (1.2 %) and UCP1-ht3 (1.1 %). Although BMI appears to exert greater effects on blood pressure, the UCP1-ht3 genotype was also found to exert a significant effect.

• International Commerce and Information Review
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• v.9 no.1
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• pp.381-399
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• 2007

UCP 600 will now come into effect on 1 July 2007, giving practitioners more than six months to prepare for the change. The vote on the UCP was also a favourable vote on eUCP Version 1.1 which was amended to bring it into conformity with the new rules. ICC Banking commission unanimeusly approved the revised UCP 600 on 26 October 2006 in paris convention. The most important revision of UCP600 have altered the technical and difficult to understand wording of UCP500 into plain simple precise and concise language, The singuler achievement of UCP600 is its elimination of phrase like "reasonable care" "reasonable time" and "an it's face" from the rule. The introduction of separate articles 2 and 3 on "Definitions" and "Interpretation" which contain the concept of "honour" along with the inclusion of certain ISBP wording in UCP, should bring about far greater clarity and precision than in many of the contentions articles in UCP500. The definition of negotiation should help lay to rest the controversies surrounding the terms of negotiation. The removal of reasonable time and the replacement by five banking days should speed the process and make L/Cs more attractive in the market, nevertheless UCP600 have many problems in appling it in practical field. For example the definition of credit, negotiation and purchase it's accepted or undertaken payment draft by accepting bank or deferred payment bank, the second advising bark's position etc. so, I will introduce in this thesis the important revised articles of UCP600 and investigate the problems in applying it in practicle field with reference to the specialist's opinion of the practical field and ICC opinions of drafting Group.