OBJECTIVE: To investigate the effects of uncoupling protein 2 (UCP2) overexpression on mitochondrial dynamics (mitochondrial division and fusion) of sepsis myocardial injury in rats. METHODS: Forty male Sprague-Dawley (SD) rats were randomly divided into four groups (n = 10): sham operation group (Sham group) using normal saline instead of transfection and simulating cecal ligation and perforation (CLP); CLP group using normal saline instead of transfection, performing CLP to induce sepsis; adeno-associated virus (AAV) group using CLP after myocardial transfection with empty virus; UCP2 overexpression group (UCP2 group) CLP was performed 3 weeks after AAV-UCP2 (1×10¹⁵ vg/L, a total of 60 μL) myocardial transfection. The rats in each group were examined by echocardiography at 24 hours after the CLP, and then the rats were sacrificed immediately to harvest myocardial tissue. Myocardial ultrastructural changes were observed under the electron microscope, the expression of regulatory proteins related to myocardial mitochondrial dynamics [optic atrophy 1 (Opa1), dynamin-related protein 1 (Drp1) and fission 1 (Fis1)] were detected by Western Blot, and the level of mitochondrial adenosine triphosphate (ATP) production was detected by chemiluminescence. RESULTS: (1) The echocardiographic results showed that there was no significant difference in left ventricular mass (LVM) and stroke volume (SV). Compared with Sham group, left ventricular diastolic anterior wall thickness (LVAWd), left ventricular systolic anterior wall thickness (LVAWs), left ventricular diastolic posterior wall thickness (LVPWd), left ventricular systolic posterior wall thickness (LVPWs), left ventricular ejection fraction (LVEF) and left ventricular short axis shortening rate (LVFS) were significantly increased in CLP group and AAV group, while left ventricular systolic diameter (LVEDs), left ventricular diastolic diameter (LVEDd), left ventricular end-systolic volume (LVESV), and left ventricular end-diastolic volume (LVEDV) were significantly decreased. Compared with CLP group and AAV group, LVAWs, LVEF, LVFS were significantly decreased in UCP2 group, and LVEDs, LVEDV and LVESV were significantly increased [LVAWs (mm): 3.82±0.42 vs. 4.34±0.30, 4.44±0.12; LVEF: 0.921±0.038 vs. 0.979±0.019, 0.991±0.010; LVFS: (65.33±6.56)% vs. (80.11±8.23)%, (85.31±6.11)%; LVEDs (mm): 1.81±0.36 vs. 0.89±0.54, 0.60±0.17; LVEDV (μL): 137.09±50.05 vs. 89.72±53.04, 85.42±40.99; LVESV (μL): 10.48±4.59 vs. 2.48±3.52, 2.58±2.50, all P < 0.05]. (2) Electron microscope showed that the structure of myocardial fibers in the Sham group was clear and aligned with complete intervertebral disc and mitochondrial structure, no damage to mitochondrial membranes, and tight arrangement of cristae. In CLP group and AAV group, muscle fiber breakage, sarcoplasmic reticulum expansion, severe mitochondrial swelling and even cristage structure disorder were observed. In the UCP2 group, only myocardial fiber edema was observed, and the muscle fiber structure was more complete than that of Sham group and AAV group. The mitochondria were slightly swollen and the cristae were intact. (3) Western Blot showed that there was no significant difference in the expression of Opa1 and Fis1 in the four groups. The expression of Drp1 in CLP group and AAV group were significantly higher than that in Sham group. The expression of Drp1 in UCP2 group was significantly lower than that in CLP group and AAV group (Drp1/β-actin: 1.01±0.03 vs. 1.39±0.03, 1.49±0.03, both P < 0.05). (4) The results of immunofluorescence showed that the ATP content of CLP group and AAV group were significantly lower than that of Sham group; the ATP content of UCP2 group was significantly higher than that of CLP group and AAV group (μmol/L: 1.99±0.15 vs. 1.10±0.17, 1.13±0.19, both P < 0.05). CONCLUSIONS UCP2 overexpression can significantly improve the systemic systolic function of myocardium in sepsis rats, protect myocardial mitochondrial ultrastructure, inhibit mitochondrial division, and improve mitochondrial ATP synthesis.
Animals ; Male ; Mitochondria, Heart ; Mitochondrial Dynamics ; Myocardium ; Rats ; Rats, Sprague-Dawley ; Sepsis ; Uncoupling Protein 2/metabolism*

OBJECTIVETo explore the association between rs659366 polymorphisms and the outcomes of patients after surgery for colorectal cancer.

METHODSThe study was conducted among a cohort of 501 patients with primary colorectal cancer who had surgery in Sichuan Cancer Hospital during March 2010 and July 2013. The outcomes of the patients were followed up. The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was applied to detect rs659366 genotypes. The log-rank test was performed to analyze the effects of clinical features on patients' outcomes. The correlation between rs659366 polymorphisms and the outcomes of patients was analyzed using the Cox proportional hazard model.

RESULTSIn this study, the median of follow-up time was 44.23(0.13-78.53)months, and 101 out of 501 (20.2%) patients failed to follow-up. The log-rank test showed the tumor site, TNM stage, vascular invasion, perineural invasion and the preoperative carcino-embryonic antigen(CEA) level were significantly associated with the outcome of colorectal cancer (<0.05 or <0.01). The overall survival rate of patients with AA, GA and GG genotypes were 62.7%, 69.9% and 75.5%, respectively. Multivariate analysis according to Cox proportional hazard model taking the GG genotype as the reference indicated that the AA genotype increased risks for survival of patients (=1.823); under the dominant genetic model taking GG genotype as reference, GA+AA genotypes increased risks for the poorer outcomes of patients (=1.498); the addictive genetic model showed that allele A increased the hazard for the poorer outcomes (=1.787).

CONCLUSIONSThe rs659366 polymorphisms are significantly associated with the outcome of patients with colorectal cancer.

Colorectal Neoplasms ; Genotype ; Humans ; Polymerase Chain Reaction ; Polymorphism, Genetic ; Proportional Hazards Models ; Survival Rate ; Uncoupling Protein 2

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

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

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

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