To establish the Chang liver cell line stably overexpressing human uncoupling protein 2 (UCP2) and observe the effect of UCP2 on mitochondrial membrane potential (MMP) and reactive oxygen species (ROS). The Chang liver cell line was transfected with recombinant plasmid containing full-length human UCP2 cDNA (pcDNA3.1-hUCP2) or pcDNA3.1 empty vector. The stable cell line was established by antibiotic screening with Zeocin. UCP2 expression was detected by Western blotting and immunocytochemistry. The UCP2 overexpressing cells were pretreated with genipin at various doses (25, 50 and 100 munol/L). MMP and intracellular ROS were detected by fluorescence spectrophotometry. The total normalized protein content in UCP2 overexpressing cells was 1.6-fold higher than that in unmanipulated normal cells. The fluorescence intensities of Rhodamine123 and DCFH-DA in UCP2 overexpressing Chang liver cells (11.11+/-2.76 and 4.97+/-0.62, respectively) were significantly lower than those in unmanipulated normal cells (15.56+/-2.55, P less than 0.01 and 6.14+/-1.25, P less than 0.05, respectively) and in cells transfected with empty vector (16.11+/-2.93, P less than 0.01 and 6.23+/-1.13, P less than 0.05, respectively). Treatment of UCP2 overexpressing cells with 25, 50 and 100 munol/L genipin caused a dose-dependent increase in fluorescence intensities of Rhodamine123 (14.89+/-2.89, 17.89+/-2.93 and 24.00+/-2.55, respectively, all P less than 0.01) and DCFH-DA (9.16+/-0.78, 10.84+/-1.09 and 11.83+/-1.25, respectively, all P less than 0.01). The Chang liver cell line stably overexpressing UCP2 was established successfully. Using this cell system, UCP2 was found to play a role in mitochondrial function by regulating MMP and ROS.
Cell Line ; Hepatocytes ; metabolism ; Humans ; Ion Channels ; biosynthesis ; Membrane Potential, Mitochondrial ; Mitochondrial Proteins ; biosynthesis ; Reactive Oxygen Species ; metabolism ; Uncoupling Protein 2

OBJECTIVETo investigate the effects of maternal nutritional manipulation on fetal mRNA abundance of uncoupling protein UCP2, UCP3 and carnitine palmityl transferase 1 (CPT1), and find out an optimal maternal diet and targets for pharmacological prevention and treatment of obesity.

METHODSWistar pregnant rats were assigned to two groups which received a standard diet (SD) and a high protein diet (HPD) during pregnancy, respectively. After delivery, the male offspring were assigned to control group (CON) and high protein group (HP) according to their maternal diet, which were suckled by dams that received SD during pregnancy. Offspring were fed with SD from weaning (week 3) to week 8. Then CON were allocated to two groups: CON (SD during the whole experiment); HFCON (high fat control). HFCON and HP group rats were fed with high-fat diet (HFD) for 6 wk to induce obesity. At 0, 3, 8 and 14 wk of age, blood and tissue were collected for analyzing blood fat and abundance of UCP2, 3 and CPT1 mRNA.

RESULTSIn HP body weight and TG were decreased after weaning (F = 4.589, P = 0.039; F = 27.001, P = 0.000) and HFD (F = 16.076, P = 0.00; F = 71.518, P = 0.000). Obesity rates were significantly decreased in HP after HFD (chi2 = 8.076, P = 0.004). The abundance of UCP3 and CPT1 mRNA was persistently higher in HP than in CON or HFCON, and the abundance of UCP2 mRNA was also persistently higher than in CON or HFCON after weaning. Moreover the abundance of CPT1 mRNA was significantly increased after weaning and HFD compared with that after SD, the abundance of UCP2, UCP3 mRNA was also increased after HFD compared with that after SD.

CONCLUSIONSIncreasing protein intake during pregnancy might prevent offspring from HFD-induced obesity in adult, moreover might increase offspring the expression of UCP2, UCP3 and CPT1 mRNA. UCP2, UCP3 and CPT1 might participate in prevention and treatment of obesity by mediating fatty acid oxidation.

Animal Feed ; Animals ; Animals, Newborn ; Carnitine O-Palmitoyltransferase ; metabolism ; Dietary Proteins ; Female ; Fertile Period ; Ion Channels ; metabolism ; Male ; Mitochondrial Proteins ; metabolism ; Obesity ; metabolism ; Pregnancy ; RNA, Messenger ; genetics ; Rats ; Rats, Wistar ; Uncoupling Protein 2 ; Uncoupling Protein 3

OBJECTIVETo investigate the additive effects of uncoupling protein 2 (UCP2) gene Ala55Val variation and ADR beta(3) gene Trp64Arg variation on the obesity in Chinese Han population.

METHODSThe UCP2 gene Ala55Val variation and ADR beta(3) gene Trp64Arg variation were examined by polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP) in 119 obese subject with mean BMI (27.9+/-2.98)kg/m(2) and in 177 control subjects with mean BMI(21.9+/-1.9)kg/m(2). The additive effects of the two gene mutations were analyzed.

RESULTS(1) The frequency of ADR beta(3) gene Trp64Arg variation in obese subjects was not significantly different from that in control subjects. In control subjects, the Trp64Arg variation carriers had higher fasting glucose level and 2-hour-post-prandial glucose level than did non-carriers. (2) The frequency of homozygote of UCP2 gene Ala55Val variation in obese subjects was higher than that in the control subjects (OR=3.71, P=0.001). In control subjects the Ala55Val variation carriers had higher BMI. (3) When there was only UCP2 gene or ADR beta(3) gene mutation, the frequency of gene mutation in obese subjects was not significantly different from that in control subjects (P>0.05). But when there were simultaneously two gene mutations, the frequency of gene mutations was higher in obese subjects than in control subjects (OR=2.57, P=0.009). (4) The genotype carriers with Val/Val+ Trp/Arg were the greatest relation to obese obesity (OR=8.58, P=0.002).

CONCLUSIONThe homozygote of UCP2 gene Ala55Val mutation increases the risk of obesity. Though the UCP2 gene mutation alone or the ADR beta(3) gene mutation alone is not associated with obesity, the possible additive effects of the two micro-genes increase the occurring of obesity.

Adult ; Aged ; Female ; Humans ; Ion Channels ; Male ; Membrane Transport Proteins ; genetics ; Middle Aged ; Mitochondrial Proteins ; genetics ; Mutation ; Obesity ; genetics ; Receptors, Adrenergic, beta-3 ; genetics ; Uncoupling Protein 2

OBJECTIVETo explore the expression changes of mRNA and protein of uncoupling protein 2 (UCP2) in adipose tissues and uncoupling protein 3 (UCP3) in muscle tissues of rats which were treated with repeated fasting/refeeding and followed by fed with high-fat diet, and their possible mechanism on lipid metabolism.

METHODSThe model of repeating fasting/refeeding rats (repeated cycles of 1-day fasting and 1-day refeeding for 6 weeks fed with common-fat diet, RFR) was designed. At the end of the 6th week, the RFR rats were switched to high-fat diet every day (RFR-CF/HF). Moreover, the control rats were randomly divided into two groups and then fed with high-fat diet (HF) and common-fat diet (CF) respectively for 6 weeks. All rats were killed at the end of the 6th and the 12th week, serum and plasma samples were taken from abdominal aorta, and then the concentration of serum lipids, glucose, free fatty acid (FFA), and plasma insulin were measured. The histomorphological changes of liver tissues were observed by HE staining. The expression level of mRNA and protein of UCP2 in adipose tissues and UCP3 in muscle tissues was respectively measured by RT-PCR and Western blot.

RESULTS(1) The concentration of serum glucose in RFR group was significantly lower than that in control group (P < 0.05), while the concentration of serum FFA, expression level of UCP2 mRNA, UCP3 mRNA and protein were significantly higher than those in control group (P < 0.05). (2) The concentration of serum total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), and plasma insulin in RFR-CF/HF group was significantly lower than that in HF group, but significantly higher than that in CF group (P < 0.05). The concentration of serum FFA was significantly lower than that of HF and CF groups (P < 0.01). The expression level in UCP2, UCP3 mRNA and protein was significantly higher than that of HF group, but significantly lower than that of CF group (P < 0.05).

CONCLUSIONThe feeding pattern of repeated fasting/refeeding can decrease the obese degree induced by high-fat diet, increase the mRNA and protein expression of UCP2 in adipose tissues and UCP3 in muscle tissues, up-regulate the proton leak caused by obesity, and improve the rate of basic energy metabolism in rats.

Adipose Tissue ; metabolism ; Animals ; Fasting ; metabolism ; Feeding Methods ; Ion Channels ; metabolism ; Lipid Metabolism ; Male ; Mitochondrial Proteins ; metabolism ; Muscles ; metabolism ; Obesity ; metabolism ; Rats ; Rats, Sprague-Dawley ; Uncoupling Protein 2 ; Uncoupling Protein 3

OBJECTIVETo investigate the expression of uncoupling protein (UCP)-2, 3 mRNA in skeletal muscle of the scalded rats after escharectomy at different post scalding stages.

METHODSOne hundred and twenty Wistar rats were employed in the study, in which 8 served as normal control (C) and 112 were subjected to 30% TBSA 3rd degree scalding and then again, divided into 4 groups. The rats in A group were sacrificed on 8th, 24th, 96th, 120th and 168th post scalding hours (PSHs) without escharectomy. The rats in B group underwent escharectomy at 8 PSH, and those in C group underwent escharectomy at 24 PSH. All the rats in both groups were sacrificed on 96, 120 and 168 PSHs after escharectomy, Escharectomy was performed at 96 PSH in rats of D group, and they were sacrificed on 120 and 168 PSHs after escharectomy. The serum levels of leptin and TNFalpha, and the expression level of UCP2 mRNA were determined at all time points in all groups of rats.

RESULTS(1) The serum levels of leptin in A group were obviously lower than that in C group (P < 0.01) during 24 approximately 168 PSHs, while those in B, C and D groups were much higher than those in A group (P < 0.01) during 24 approximately 168 PSH. (2) The serum TNFalpha levels in A group at all time points were higher than that in control group, while that in B group at all time points were lower than that in A group (P < 0.05 or 0.01), and that in C group at 168 PSH was lower than that in A group (P < 0.05). (3) The UCP2 mRNA expression in skeletal muscle in A group was increased evidently since 8 PSH (P < 0.01), peaking at 24 PSH and lowering thereafter, while that in B and C groups at 168PSH was significantly lower than that in A group at the same time points (0.32 and 0.35 vs 0.71, P < 0.05). The trend of the change in UCP3 mRNA expression in skeletal muscle was similar to that of UCP2.

CONCLUSIONThe postburn up-regulation of UCP mRNA expression might play important roles in the increase of metabolic rate. Escharectomy during shock stage could lower down the expression of UCP2 and UCP3 mRNA expression, and it could be beneficial by lowering metabolic rate.

Animals ; Burns ; metabolism ; surgery ; Cicatrix ; metabolism ; surgery ; Ion Channels ; metabolism ; Male ; Mitochondrial Proteins ; metabolism ; Muscle, Skeletal ; metabolism ; RNA, Messenger ; metabolism ; Rats ; Rats, Wistar ; Time Factors ; Uncoupling Protein 2 ; Uncoupling Protein 3

Animals ; Ethanol ; pharmacology ; Ion Channels ; metabolism ; Liver ; metabolism ; Liver Diseases, Alcoholic ; metabolism ; Male ; Mitochondrial Proteins ; metabolism ; Oxidative Stress ; Rats ; Rats, Wistar ; Uncoupling Protein 2

Animals ; Fatty Liver ; metabolism ; Humans ; Ion Channels ; biosynthesis ; genetics ; physiology ; Mitochondrial Proteins ; biosynthesis ; genetics ; physiology ; RNA, Messenger ; biosynthesis ; genetics ; Uncoupling Protein 2

OBJECTIVEGerm cells are much more susceptible to oxidative stress than somatic cells. Accumulating evidence indicates that uncoupling protein 2 (UCP2) prevents the apoptosis of multiple types of cells induced by reactive oxygen species (ROS). The present study aimed to evaluate the protective effect of uncoupling protein 2 (UCP2) against oxidative damage to human sperm.

METHODSSemen parameters were obtained from 97 semen samples by computer assisted sperm analysis (CASA), and the samples, based on the percentage of grade a + b sperm, allotted to Groups I (n = 25, grade a + b sperm > 50%), II (n = 24, grade a + b sperm 25%-50%), III (n = 24, grade a + b sperm 10-25%) and IV (n = 24, grade a + b sperm < 10%). The expressions of sperm UCP2 mRNA was detected by RT-PCR, and the malonaldehyde (MDA) content in ROS was determined in the sperm suspension.

RESULTSThe expressions of UCP2 mRNA in sperm were 1.51 +/- 0.24, 1.28 +/- 0.15, 1.17 +/- 0.20 and 0.69 +/- 0.18, and the MDA contents were (14.66 +/- 2.55), (16.00 +/- 2.09), (17.44 +/- 1.40) and (21.20 +/- 3.50) nmol/10(8) sperm in Groups I, II, III and lV, respectively. There was a significant negative correlation between the expression of UCP2 mRNA and the content of MDA (r = -0.633, P < 0.01), the former obviously reduced while the latter remarkably increased in the groups of lower sperm motility (P < 0.01).

CONCLUSIONUCP2 plays an important protective role against oxidative stress damage to human sperm by diminishing ROS production.

Adult ; Humans ; Ion Channels ; metabolism ; Male ; Middle Aged ; Mitochondrial Proteins ; metabolism ; Oxidative Stress ; Reactive Oxygen Species ; metabolism ; Sperm Count ; Sperm Motility ; Spermatozoa ; metabolism ; Uncoupling Protein 2

OBJECTIVETo review the current advances on the role of uncoupling protein (UCP) in the pathogenesis and progress of nonalcoholic fatty liver disease (NAFLD).

DATA SOURCESA comprehensive search of the PubMed literature without restriction on the publication date was carried out using keywords such as UCP and NAFLD.

STUDY SELECTIONArticles containing information related to NAFLD and UCP were selected and carefully analyzed.

RESULTSThe typical concepts, up-to-date findings, and existing controversies of UCP2 in NAFLD were summarized. Besides, the effect of a novel subtype of UCP (hepatocellular down regulated mitochondrial carrier protein, HDMCP) in NAFLD was also analyzed. Finally, the concept that any mitochondrial inner membrane carrier protein may have, more or less, the uncoupling ability was reinforced.

CONCLUSIONSConsidering the importance of NAFLD in clinics and UCP in energy metabolism, we believe that this review may raise research enthusiasm on the effect of UCP in NAFLD and provide a novel mechanism and therapeutic target for NAFLD.

Animals ; Fatty Acids, Nonesterified ; metabolism ; Fatty Liver ; etiology ; metabolism ; Humans ; Ion Channels ; physiology ; Mitochondrial Proteins ; analysis ; chemistry ; physiology ; Non-alcoholic Fatty Liver Disease ; Uncoupling Protein 2

Animals ; Fatty Liver ; metabolism ; Insulin ; metabolism ; Insulin Resistance ; Ion Channels ; metabolism ; Male ; Mitochondrial Proteins ; metabolism ; Rats ; Rats, Wistar ; Uncoupling Protein 2