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

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 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

OBJECTIVE: In this study, the combined effect of two stressors, namely, electromagnetic fields (EMFs) from mobile phones and fructose consumption, on hypothalamic and hepatic master metabolic regulators of the AMPK/SIRT1-UCP2/FOXO1 pathway were elucidated to delineate the underlying molecular mechanisms of insulin resistance. METHODS: Weaned Wistar rats (28 days old) were divided into 4 groups: Normal, Exposure Only (ExpO), Fructose Only (FruO), and Exposure and Fructose (EF). Each group was provided standard laboratory chow ad libitum for 8 weeks . Additionally, the control groups, namely, the Normal and FruO groups, had unrestricted access to drinking water and fructose solution (15%), respectively. Furthermore, the respective treatment groups, namely, the ExpO and EF groups, received EMF exposure (1,760 MHz, 2 h/day x 8 weeks). In early adulthood, mitochondrial function, insulin receptor signaling, and oxidative stress signals in hypothalamic and hepatic tissues were assessed using western blotting and biochemical analysis. RESULT: In the hypothalamic tissue of EF, SIRT1, FOXO 1, p-PI3K, p-AKT, Complex III, UCP2, MnSOD, and catalase expressions and OXPHOS and GSH activities were significantly decreased ( P < 0.05) compared to the Normal, ExpO, and FruO groups. In hepatic tissue of EF, the p-AMPKα, SIRT1, FOXO1, IRS1, p-PI3K, Complex I, II, III, IV, V, UCP2, and MnSOD expressions and the activity of OXPHOS, SOD, catalase, and GSH were significantly reduced compared to the Normal group ( P < 0.05). CONCLUSION The findings suggest that the combination of EMF exposure and fructose consumption during childhood and adolescence in Wistar rats disrupts the closely interlinked and multi-regulated crosstalk of insulin receptor signals, mitochondrial OXPHOS, and the antioxidant defense system in the hypothalamus and liver.
Humans ; Rats ; Animals ; Adult ; Rats, Wistar ; Fructose/metabolism* ; Catalase ; Receptor, Insulin/metabolism* ; AMP-Activated Protein Kinases/metabolism* ; Electromagnetic Fields/adverse effects* ; Sirtuin 1/metabolism* ; Cell Phone ; Phosphatidylinositol 3-Kinases/metabolism* ; Forkhead Box Protein O1/metabolism* ; Uncoupling Protein 2

OBJECTIVETo observe the effects of beta3-adrenergic receptor(beta3-AR) antagonist on myocardial uncoupling protein 2 (UCP2) expression and energy metabolism in chronic heart failure rats.

METHODSSeven weight-matched normal adult rats (control group), 18 isoproterenol (ISO) induced heat failure (HR) rats (ISO group) and 21 ISO induced heart failure rats but received specific beta3-AR inhibitor SR59230A (ISO+ SR59230A group) for 6 weeks were included in this research. At the end of the study, echocardiography was performed, the ratio of left ventricular weight and body weight (LVW/BW) was calculated. The expression of beta3-AR ad UCP2 mRNA in myocardium were detected by reverse transcription-polymerase chain reaction (RT-PCR), the UCP2 protein in myocardium were detected by Western blot. The myocardial contents of creatine phosphate (PCr) and adenosine triphosphate (ATP) were measured by high performance liquid chromatography (HPLC).

RESULTSCompared with control group, the cardiac function was significantly reduced and myocardial beta3-AR mRNA significantly increased, UCP2 mRNA and protein were also significantly increased in ISO group, this change could be attenuated by the treatment with SR59230A, and the expression of myocardial UCP2 protein negatively correlated with the ratio of PCr/ATP.

CONCLUSIONIn the chronic stage of HF, the expression of UCP2 increases, which causes myocardial energy shortage, SR59230A improves myocardia energy efficiency and cardiac function by means of suppressing the expression of UCP2.

Adrenergic Antagonists ; pharmacology ; Animals ; Energy Metabolism ; Heart Failure ; metabolism ; Ion Channels ; metabolism ; Male ; Mitochondrial Proteins ; metabolism ; Myocardium ; metabolism ; Rats ; Rats, Wistar ; Receptors, Adrenergic, beta-3 ; metabolism ; Uncoupling Protein 2

OBJECTIVETo investigate the relationship of the C to T variant at the -55 site of the promoter region of uncoupling protein 3 gene (UCP3) with the resting energy expenditure and the parameters of body fat in Chinese population.

METHODSThree hundred Chinese (91 normal weight subjects, 209 overweight/obesity subjects) were genotyped for the UCP3 gene -55(C>T) by using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Resting energy expenditure (REE), fat mass (FM), fat free mass (FFM) and the parameters for regional adipose tissue distribution were measured.

RESULTSGenotype frequencies of UCP3 gene -55(C>T) were not associated with obesity and different types of obesity. The REE level in normal weight subjects with TT homozygotes was higher than that in those with CT heterozygotes and CC homozygotes (P=0.0200). Similar tendency was also observed in overweight/obesity subjects. The FM/FFM exhibited significant difference between the overweight/obesity subjects with a TT genotype and those with a CT or CC genotype (P=0.0096).

CONCLUSIONThe level of difference in REE caused by the polymorphism of promoter region of UCP3 -55(C>T) may play a role in energy metabolism in Chinese.

Adipose Tissue ; metabolism ; Asian Continental Ancestry Group ; genetics ; China ; Energy Metabolism ; physiology ; Female ; Humans ; Ion Channels ; genetics ; physiology ; Male ; Middle Aged ; Mitochondrial Proteins ; genetics ; physiology ; Polymerase Chain Reaction ; Polymorphism, Restriction Fragment Length ; Polymorphism, Single Nucleotide ; Uncoupling Protein 3

The physiological significance of skeletal muscle mitochondrial uncoupling protein 3 (UCP3) in hypoxia is elusive. In the current study, UCP3 mRNA and protein expressions were investigated along with mitochondrial respiratory function, reactive oxygen species (ROS) generation, as well as manganese superoxide dismutase (MnSOD) expression in rat skeletal muscle with or without endurance training after an acute and severe hypobaric hypoxia exposure for different time. Acute hypoxia induced a series of impairments in skeletal muscle mitochondrial bioenergetics. In untrained rats, UCP3 protein content increased by 60% above resting level at 4 h hypoxia, whereas MnSOD protein content and activity were unaltered. UCP3 upregulation increased mitochondrial uncoupling respiration thus reducing O2(.-) generation, but inevitably decreased ATP production. Training decreased acute hypoxia-induced upregulation of UCP3 protein (67% vs 42%) in rat skeletal muscle. ROS production in trained rats also showed a dramatic decrease at 2 h, 4 h and 6 h, respectively, compared with that in untrained rats. MnSOD protein contents and activities were significantly (50% and 34%) higher in trained than those in untrained rats. Training adaptation of MnSOD may enhance the mitochondrial tolerance to ROS production, and reduce UCP3 activation during severe hypoxia, thus maintaining the efficiency of oxidative phosphorylation. In trained rats, mitochondrial respiratory control (RCR) and P/O ratios were maintained relatively constant despite severe hypoxia, whereas in untrained rats RCR and P/O ratios were significantly decreased. These results indicate that (1) UCP3 mRNA and protein expression in rat skeletal muscle are upregulated during acute and severe hypobaric hypoxia, which may reduce the increased cross-membrane potential (Deltapsi) and thus ROS production; (2) Endurance training can blunt hypoxia-induced UCP3 upregulation, and improve mitochondrial efficiency of oxidative phosphorylation due to increased removal of ROS.
Animals ; Energy Metabolism ; Ion Channels ; physiology ; Membrane Potentials ; Mitochondria, Muscle ; physiology ; Mitochondrial Proteins ; physiology ; Physical Conditioning, Animal ; Physical Endurance ; Rats ; Reactive Oxygen Species ; metabolism ; Superoxide Dismutase ; metabolism ; Uncoupling Protein 3

OBJECTIVETo observe the effect and mechanism of Pingtang Recipe containing drug-serum (DS-PTR) in improving INS-1 beta pancreatic cells lipoapoptosis.

METHODSExperimental INS-1 beta cells were divided into 5 groups (6 pools for each group), namely, the blank control group treated with rat's serum (C), the other 4 model groups induced into lipoapoptosis by palmitic acid and treated respectively by rat's serum (M), high, middle and low dose DS-PTR (DSh, DSm and DSI). Cell apoptosis was detected by TUNEL staining; Caspase-3 activity of cells was measured by chemiluminescence method; intracellular production of reactive oxygen species (ROS) was detected by DCHF-DA incorporation, and expressions of uncoupling protein-2 (UCP-2) was determined by RT-PCR.

RESULTSINS-1 beta cell apoptosis in Group M was significantly higher than that in Group C (P < 0.01), while that showed a decreased trend in the three DS-PTR treated groups. Caspase-3 activity was enhanced in Group M, it decreased significantly in Group DSm (P < 0.05). The over-produced ROS in cells after modeling was inhibited in Groups DSm and DSI (P < 0.05), meantime, expression of UCP-2 excited by PA (2.244 +/- 0.421) was reduced significantly in Group DSI and Group DSm to 1.286 +/- 0.373 (P < 0.01) and 1.627 +/- 0.348 (P < 0.05) respectively.

CONCLUSIONDS-PTR shows a protective effect on INS-1 beta pancrentic cells against lipoapoptosis, which is possibly play its mechanism through regulating ROS and UCP-2.

Animals ; Apoptosis ; drug effects ; Caspase 3 ; metabolism ; Cell Line ; Drugs, Chinese Herbal ; pharmacology ; Insulin-Secreting Cells ; cytology ; Ion Channels ; genetics ; metabolism ; Male ; Mitochondrial Proteins ; genetics ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley ; Reactive Oxygen Species ; metabolism ; Serum ; Uncoupling Protein 2

OBJECTIVETo investigate the relationship of UCP3 gene -55 C-->T variant with lipid metabolism, body fat, its distribution and non-insulin-dependent diabetes mellitus(NIDDM) in Chinese.

METHODSPolymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP) was used to detect the genotype of UCP3 gene -55 C-->T in a total of 316 Chinese including 165 individuals with normal glucose tolerance(NGT) and 151 patients with type 2 diabetes). MRI was used to detect local body fat; the enzyme method and sulfate-sephadex-manganese precipitation method were used to detect TC and HDL-C, and then LDL-C was calculated with corresponding formula.

RESULTS(1)No difference was seen on comparing allele and genotype frequencies of Chinese with those of Caucasian (P=0.1120 and P=0.0646, respectively), whereas significant difference in these frequencies was seen between Chinese and Pima Indians(P=0.0 105 and P=0.0314, respectively). (2)Stepwise regression analysis revealed that the independent variables to UCP3 gene -55 C-->T were: HDL-C(P= 0.013)and LDL-C(P=0.012) in male NGT subgroup FA(P=0.023) in female NGT subgroup TG(P=0.004)in male DM subgroup, and waist to hip ratio (WHR)(P=0)in female DM subg roup. (3)The allele frequency of DM group was significantly different from that of NGT(P =0.0358). The odd ratio for the T allele carrier with NIDDM was 1.434 (95%CI 1.031-1.995).

CONCLUSIONAlthough UCP3 gene 55 C-->T variant is associated with lipid metabolism, body fat and its distribution in Chinese, the association is dependent on sex and disease status. The variant is also associated with NIDDM in Chinese.

Adipose Tissue ; metabolism ; Adult ; Aged ; Alleles ; Body Constitution ; Body Mass Index ; Carrier Proteins ; genetics ; China ; Cholesterol ; metabolism ; Cholesterol, HDL ; metabolism ; Cholesterol, LDL ; metabolism ; Diabetes Mellitus, Type 2 ; genetics ; metabolism ; Female ; Gene Frequency ; Genotype ; Humans ; Ion Channels ; Lipid Metabolism ; Male ; Middle Aged ; Mitochondrial Proteins ; Point Mutation ; Regression Analysis ; Triglycerides ; metabolism ; Uncoupling Protein 3