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1.
Aims/hypothesis. The UCP2-UCP3 gene region has been previously associated with obesity and diabetes. In a large representative cohort of Northern France (MONICA project), we studied the effect of a recently reported C/T polymorphism located in the 5' sequences of the UCP3 gene on anthropometric measurements and lipid profile. We also examined the association of this polymorphism with obesity and Type II (non-insulin-dependent) diabetes mellitus.¶Methods. The –55 C/T polymorphism of the UCP3 gene has been genotyped in 1155 subjects from the MONICA project. Association studies were done with diabetes, obesity and related phenotypes. Results were ascertained in a second cohort of well-characterized Type II diabetic and control subjects.¶Results. The variant T allele was associated with a decreased risk of developing Type II diabetes. Frequencies of the T allele were 13.3 % compared with 22 %, p = 0.04, in the diabetic and control groups, respectively. This observation was confirmed in the second cohort of French Type II diabetic (n = 171) and control (n = 124) subjects: 17.8 % compared with 25 %, p = 0.03. Moreover, subjects bearing the TT genotype had higher plasma total cholesterol and LDL-cholesterol concentrations (p = 0.0006 and p = 0.001, respectively) than subjects bearing wild or heterozygous genotypes.¶Conclusion/interpretation. The UCP3–55 C/T polymorphism was associated with a higher atherogenic profile and modified the risk for the development of Type II diabetes. [Diabetologia (2000) 43: 1424–1428]  相似文献   

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Aims/hypothesis. We aimed to quantify changes in insulin action and insulin secretion associated with long-term gain, loss, regain, and maintenance of body weight in subjects with normal (NGT) or impaired (IGT) glucose tolerance.¶Methods. Insulin action (hyperinsulinaemic clamp) and insulin secretion (intravenous glucose challenge) were measured longitudinally in 209 Pima Indians [body weight 94.4 ± 22.8 kg (means ± SD) 89 women/120 men, 151 NGT/58 IGT], who either lost (n = 110) or gained (n = 99) weight (–23 % to + 29 %) over 2.6 ± 2.0 years. Insulin action and insulin secretion were reassessed on a third occasion in 33 subjects who lost at least 5 % body weight over 1.5 ± 0.8 years and then either regained or maintained weight over the subsequent 1.8 ± 1.1 years.¶Results. There was a linear negative relation between changes in body weight and changes in insulin-stimulated glucose disposal in subjects with normal glucose tolerance (r = – 0.51, p < 0.0001) and impaired glucose tolerance (r = – 0.54, p < 0.0001). In contrast, changes in the acute insulin response were positively related to weight changes in subjects with normal glucose tolerance (r = + 0.26, p < 0.005) but negatively in those with impaired glucose tolerance (r = – 0.51, p < 0.0001). Improvements in insulin action after an average of 10 % weight loss were lost with weight regain but largely preserved with weight maintenance.¶Conclusion/interpretation. Improvements in insulin action are proportional to the amount of weight loss, similar in magnitude to the impairment in insulin action with weight gain, preserved with long-term weight maintenance and similar between subjects with normal and with impaired glucose tolerance. Weight gain could, however, have more detrimental effects in people with impaired glucose tolerance, in whom insulin secretion decreases rather than increases to compensate for the decreased insulin action. [Diabetologia (2000) 43: 36–46]  相似文献   

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PURPOSE: Findings recently have shown coupling protein-3 (UCP3) content to be decreased in the skeletal muscle of patients with chronic obstructive pulmonary disease (COPD). Uncoupling protein-3 mRNA exists as two isoforms: long (UCP3L) and short (UCP3S). The UCP3 protein is expressed the least in oxidative and the most in glycolytic muscle fibers. Levels of UCP3 have been associated positively with intramyocellular triglyceride (IMTG) contents in conditions of altered fatty acid metabolism. As a source for muscle free fatty acid metabolism, IMTG is decreased in COPD. The current study completely characterized all the parameters of UCP3 expression (ie, UCP3L and UCP3S mRNA expression in whole muscle samples) and UCP3 protein content as well as IMTG content in the different fiber types in patients with COPD and healthy control subjects. METHODS: Using real-time polymerase chain reaction, UCP3 gene expression was quantified. Skeletal muscle fiber type and UCP3 protein and IMTG content were measured using immunofluorescence and Oil red oil staining, respectively. RESULTS: The findings showed that UCP3L mRNA expression was 44% lower (P < .005) in the patients with COPD than in the control subjects, whereas the UCP3S mRNA content was similar in the two groups. As compared with control subjects, UCP3 protein content was decreased by 89% and 83% and the IMTG content by 64% and 54%, respectively, in types I and IIa fibers (P < .0167) of patients with COPD, whereas they were unchanged in IIx fibers. CONCLUSIONS: The reduced UCP3 and IMTG content in the more oxidative fibers may be linked to the altered muscle fatty acid metabolism associated with COPD. Further studies are required to determine the exact role and clinical relevance of the reduced UCP3 content in patients with COPD.  相似文献   

4.
Aims/hypothesis. In obese French Caucasian subjects we previously described a silent UCP3 Tyr99Tyr mutation, associated with body mass index. We hypothesised that an unknown polymorphism in the vicinity of the gene could contribute to obesity.¶Methods. Morbidly obese subjects were screened for mutations in 1 kb upstream from the UCP3 gene. Association studies were done between a variant and obesity in 401 morbidly obese and 231 control subjects.¶Results. We detected three rare genetic variants and one polymorphism: a + 5 G→A in exon 1, a –155 C→T, a –439 A insertion and a –55 C→T located 6 bp from the putative TATA box. This variant was in linkage disequilibrium with the Tyr99Tyr polymorphism. Frequencies of the variant allele at the –55 locus were similar in the obese and control groups (0.23 vs 0.21). The –55 polymorphism was associated with BMI in the obese group (p = 0.0031): BMI was higher in TT than in CC or CT patients. Likewise control subjects with a TT genotype had a higher BMI (p = 0.03). In the obese group, homozygocity for this variant is a risk factor for high BMI (odds ratio: 1:75, p = 0.02). Obese patients were divided into tertiles according to physical activity. In the group with a wild C/C genotype, BMI was negatively associated with physical activity (p = 0.015).¶Conclusion/interpretation. The C→T polymorphism in the 5 ′ sequences of the UCP3 gene might contribute to the corpulence in obese and normal weight subjects and alter the benefit of physical activity. The UCP3 gene can be considered as a gene modifying corpulence. [Diabetologia (2000) 43: 245–249]  相似文献   

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OBJECTIVE: In rodents, adaptive thermogenesis in response to cold exposure and high-fat feeding is accomplished by the activation of the brown adipose tissue specific mitochondrial uncoupling protein, UCP1. The recently discovered human uncoupling protein 3 is a possible candidate for adaptive thermogenesis in humans. In the present study we examined the effect of mild cold exposure on the mRNA and protein expression of UCP3. SUBJECTS: Ten healthy male volunteers (age 24.4 +/- 1.6 y; height 1.83 +/- 0.02 m; weight 77.3 +/- 3.0 kg; percentage body fat 19 +/- 2). DESIGN: Subjects stayed twice in the respiration chamber for 60 h (20.00-8.00 h); once at 22 degrees C (72 degrees F), and once at 16 degrees C (61 degrees F). After leaving the respiration chamber, muscle biopsies were taken and RT-competitive-PCR and Western blotting was used to measure UCP3 mRNA and protein expression respectively. RESULTS: Twenty-four-hour energy expenditure was significantly increased at 16 degrees C compared to 22 degrees C (P<0.05). At 16 degrees C, UCP3T (4.6 +/- 1.0 vs 7.7 +/- 1.5 amol/microg RNA, P=0.07), UCP3L (2.0 +/- 0.5 vs 3.5 +/- 0.9 amol/microg RNA, P=0.1) and UCP3S (2.6 +/- 0.6 vs 4.2 +/- 0.7 amol/microg RNA, P=0.07) mRNA expression tended to be lower compared with at 22 degrees C, whereas UCP3 protein content was, on average, not different. However, the individual differences in UCP3 protein content (16-22 degrees C) correlated positively with the differences in 24 h energy expenditure (r=0.86, P<0.05). CONCLUSION: The present study suggests that UCP3 protein content is related to energy metabolism in humans and might help in the metabolic adaptation to cold exposure. However, the down-regulation of UCP3 mRNA with mild cold exposure suggests that prolonged cold exposure will lead to lower UCP3 protein content. What the function of such down-regulation of UCP3 could be is presently unknown.  相似文献   

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OBJECTIVE: To test the hypothesis that consumption of a high-fat diet leads to an increase in UCP mRNA expression in human skeletal muscle. In a group of endurance athletes, with a range in fiber type distribution, we hypothesized that the effect of the high-fat diet on UCP2 and UCP3 mRNA expression is more pronounced in muscle fibers which are known to have a high capacity to shift from carbohydrate to fat oxidation (type IIA fibers). DESIGN: Ten healthy trained athletes (five males, five females) consumed a low-fat diet (17+/-0.9 en% of fat) and high-fat diet (41.4+/-1.4 en% fat) for 4 weeks, separated by a 4 week wash-out period. Muscle biopsies were collected at the end of both dietary periods. MEASUREMENTS: Using RT-PCR, levels of UCP2 and UCP3 mRNA expression were measured and the percentage of type I, IIA and IIB fibers were determined using the myofibrillar ATPase method in all subjects. RESULTS: UCP3L mRNA expression tended to be higher on the high-fat diet, an effect which reached significance when only males were considered (P=0.037). Furthermore, diet-induced change in mRNA expression of UCP3T (r: 0.66, P=0.037), UCP3L (r: 0.61, P=0.06) and UCP2 (r: 0.70, P=0.025), but not UCP3S, correlated significantly with percentage dietary fat on the high-fat diet. Plasma FFA levels were not different during the two diets. Finally, the percentage of type IIA fibers was positively correlated with the diet-induced change in mRNA expression for UCP2 (r: 0.7, P=0.03), UCP3L (r: 0.73, P=0.016) and UCP3T (r: 0.68, P=0.03) but not with UCP3S (r: 0.06, NS). CONCLUSION: UCP2 and UCP3 mRNAs are upregulated by a high-fat diet. This upregulation is more pronounced in humans with high proportions of type IIA fibers, suggesting a role for UCPs in lipid utilization.  相似文献   

8.
Aims: Associations between a 45 bp 3 ′untranslated insertion polymorphism in the uncoupling protein 2 (UCP2) gene and both body mass index (BMI) and sleeping metabolic rate have previously been reported. We investigated the impact of this polymorphism on BMI and long-term body weight changes.¶Methods. The allelic frequency of the UCP2 insertion variant was determined in a cohort of 744 obese Danish Caucasian men who had a BMI of at least 31 kg/m2 at the draft-board examinations and a randomly selected control cohort consisting of 872 draftees. Follow-up measurements of BMI were done on average 26 years after the draft-board examinations.¶Results. The prevalence of the insertion allele was 30.4 % (95 % confidence interval: 28.0–32.8 %) among the obese and 29.6 % (27.4–31.8 %) in the control group (p = 0.6). In a lean group selected as the 354 subjects with a BMI less than 25 kg/m2 at 46 years of age from the control group, the frequency of insertion allele was 29.0 % (27.2–30.8 %) (p = 0.5 compared with the obese cohort). The BMI at the ages of 20 and 46 years did not differ between genotypes either in the obese or the control group. Similarly, the changes in BMI/year between examinations at 20 and 46 years of age did not differ between genotypes in either group.¶Conclusion/interpretation. In a large group of Danish Caucasian men we found no association between a 3 ′untranslated insertion polymorphism in the UCP2 gene and obesity. Neither did we identify a relation between this variant and BMI changes during adult age. [Diabetologia (1999) 42: 1413–1416]  相似文献   

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Larsson H  Ahrén B 《Diabetologia》2000,43(2):194-202
Aims/hypothesis. To study the pathophysiological importance of changes in insulin sensitivity and islet function over time for alterations in glucose tolerance in a randomly selected large group of non-diabetic women aged 57–59 years over a 3-year period.¶Methods. At baseline and at the 3-year follow-up, glucose tolerance (WHO 75 g oral glucose), insulin sensitivity (euglycaemic, hyperinsulinaemic clamp) and insulin and glucagon secretion (2 to 5-min responses to 5 g i. v. arginine at fasting, 14 and > 25 mmol/l glucose) were measured.¶Results. At baseline, women with impaired glucose tolerance (IGT, n = 28) had lower insulin sensitivity (p = 0.048) than normal women (NGT, n = 58). The arginine-induced insulin responses (AIR) were inversely associated with insulin sensitivity (r≥– 0.55, p < 0.001). When related to the 3-year follow-up, the baseline product of AIR at 14 mmol/l glucose times insulin sensitivity, insulin effect index (IE) (r = – 0.40, p < 0.001) and the arginine-induced glucagon response at 14 mmol/l glucose (AGR, r = 0.28, p = 0.009) both correlated with follow-up 2-h glucose. In a multiple regression model, baseline 2-h glucose, insulin effect index and arginine-induced glucagon response independently predicted 2-h glucose at follow-up (total r = 0.668, p < 0.001). Furthermore, Δinsulin sensitivity (i. e. follow-up minus baseline) correlated with Δinsulin secretion (r = – 0.30, p = 0.006), whereas Δglucagon secretion correlated with Δ2-h glucose (r = 0.30, p = 0.006) over the 3 years. In a multiple regression, alterations in 2-h glucose over the 3 years were independently determined by changes in fasting insulin and glucagon secretion (r = 0.424, p < 0.001).¶Conclusion/interpretation. Low insulin secretion, when judged in relation to insulin sensitivity, and high glucagon secretion, determine glucose tolerance over time in the individual subject. These processes are therefore potential targets for prevention of deterioration in glucose tolerance. [Diabetologia (2000) 43: 194–202]  相似文献   

12.
In the present investigation we describe the life span characteristics and phenotypic traits of ad libitum-fed mice that overexpress UCP2/3 (Positive-TG), their non-overexpressing littermates (Negative-TG), mice that do not expression UCP2 (UCP2KO) or UCP3 (UCP3KO), and wild-type C57BL/6J mice (WT-Control). We also included a group of C57BL/6J mice calorie-restricted to 70% of ad libitum-fed mice in order to test partially the hypothesis that UCPs contribute to the life extension properties of CR. Mean survival was slightly, but significantly, greater in Positive-TG, than that observed in Negative-TG or WT-Control; mean life span did not significantly differ from that of the UCP3KO mice. Maximal life span did not differ among the ad libitum-fed groups. Genotype did not significantly affect body weight, food intake, or the type of pathology at time of death. Calorie restriction increased significantly mean and maximal life span, and the expression of UCP2 and UCP3. The lack of difference in maximal life spans among the Positive-TG, Negative-TG, and UCP3KO suggests that UCP3 does not significantly affect longevity in mice.  相似文献   

13.
OBJECTIVE: To analyse the impact of vitamin A supplementation of both a normal fat (NF) diet and a high fat (HF) diet and of acute retinoic acid (RA)-treatment on the expression of uncoupling protein 3 (UCP3) in mice. DESIGN: C57BL/6J mice were fed for 18 weeks a NF or a HF diet (10 and 45 energy% as fat, respectively), both with the normal vitamin A content or an excess vitamin A (8 mg and 320 mg retinyl palmitate/kg diet, respectively). Body weight and energy intake were recorded periodically. UCP3 mRNA and UCP3 protein levels in skeletal muscle (soleus/gastrocnemius) were analysed, as well as UCP1, UCP2 and UCP3 mRNA levels in interscapular brown adipose tissue (BAT), and UCP2 mRNA, UCP2 protein and leptin mRNA levels in white adipose tissue (WAT) depots. The effect of acute RA-treatment (100 mg/kg/day, 4 days) on UCP3 mRNA levels in skeletal muscle and BAT of NMRI mice was also assessed. RESULTS: Vitamin A supplementation of a NF diet led to increased levels of UCP3 mRNA and UCP3 protein in muscle, UCP1 mRNA in BAT, and UCP2 mRNA in inguinal WAT, but had no impact on body weight or adiposity of B6 mice. HF diet promoted obesity and increased levels of UCP3 mRNA and UCP3 protein in skeletal muscle, and of the mRNAs for all three UCPs in BAT. Supplementing the HF diet with vitamin A had little effect on the final obesity reached and did not lead to further increases of muscle UCP3 mRNA nor BAT UCP1 mRNA over the levels achieved with the non-supplemented HF diet. Adipose leptin mRNA levels were down regulated after vitamin A supplementation, independently of the fat content of the diet. Up-regulation of muscle, but not BAT, UCP3 mRNA levels was also found after acute RA-treatment in NMRI mice. CONCLUSION: The results provide evidence of a stimulatory effect of retinoids on muscle UCP3 expression in vivo, and a differential retinoid-regulation of the UCP3 gene in muscle and BAT.  相似文献   

14.
Aims/hypothesis. Alterations in the regulation of gene expression could be involved in the development of Type II (non-insulin-dependent) diabetes mellitus.¶Methods. We compared the mRNA concentrations of eight genes encoding proteins involved in insulin action and intermediary metabolism in skeletal muscle of healthy volunteers and Type II diabetic patients. The in vivo regulation of the expression of these genes was investigated after 5 days of hypocaloric diet (1045 kJ/day).¶Results. In the basal state, diabetic muscle showed reduced insulin receptor (–38 %), hexokinase II (–73 %), glycogen synthase (–45 %) and lipoprotein lipase (–70 %) mRNA expression. There was no difference in the mRNA abundances of IRS-1, GLUT 4, p85α phosphatidylinositol-3-kinase (p85αPI3K) or Rad. In both groups, caloric restriction induced weight loss, reduced glycaemia and increased plasma ketone body concentrations. The diet also increased plasma concentrations of fatty acids and decreased whole-body insulin sensitivity in control subjects. In control subjects, the diet increased p85αPI3K ( + 146 %), insulin receptor ( + 100 %) and Rad ( + 40 %) mRNA concentrations in muscle. In Type II diabetic patients, the diet increased insulin receptor ( + 41 %) and Rad ( + 31 %) mRNAs but the expression of p85αPI3K was not modified.¶Conclusion/interpretation. The regulation of the expression of p85αPI3K is altered during caloric restriction in skeletal muscle of Type II diabetic patients. Because we have shown in an earlier study that there is also a defective regulation of p85αPI3K gene expression in response to insulin, these data support the hypothesis that alterations in the regulation of gene expression could be involved in the pathogenesis of Type II diabetes. [Diabetologia (2000) 43: 356–363]  相似文献   

15.
Aims/hypothesis It has been suggested that uncoupling protein 3 (UCP3) can increase energy expenditure, thereby regulating body weight. Although studies on UCP3 knock-out mice suggest that lack of UCP3 function does not cause obesity or Type 2 diabetes, it is possible that up-regulation of UCP3 function improves these disorders or their clinical sequelae. A 10- to 20-fold increase of UCP3 gene expression is achievable through physiological or pharmacological stimuli. We examined the phenotype of transgenic mice with approximately 18-fold overexpression of mouse UCP3 mRNA in skeletal muscle.Methods We generated transgenic mice with approximately 18-fold overexpression of mouse UCP3 mRNA in skeletal muscle under control of the skeletal muscle-specific muscle creatine kinase gene promoter. The phenotype of these mice was analysed either on a standard diet or on a 4-week high-fat diet.Results In mice on standard chow, there was no difference in body weight, oxygen consumption and mitochondrial protonmotive force between transgenic mice and non-transgenic littermates. However, transgenic mice tended to have lower body weight, increased oxygen consumption and decreased mitochondrial protonmotive force than the control mice. Transgenic mice on a 4-week high-fat diet consumed much more oxygen and had noticeably less weight gain and less epididymal fat, as well as better glucose tolerance than non-transgenic littermates.Conclusions/interpretation Our study shows that 18-fold overexpression of UCP3 mRNA in the skeletal muscle reduced diet-induced obesity. An 18-fold increase of UCP3 mRNA can be attained by physiological or pharmacological stimuli, suggesting that UCP3 has therapeutic potential in the treatment of obesity.Abbreviations UCP3 uncoupling protein 3 - UCP2 uncoupling protein 2 - UCP1 uncoupling protein 1 - PPAR peroxisome-proliferator-activated receptor - MCK muscle creatine kinase - p mitochondrial protonmotive force  相似文献   

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The relationship between interscapular brown adipose tissue (IBAT) thermogenic potential and vitamin A status was investigated by studying the effects of feeding a vitamin A-deficient diet and all-trans retinoic acid (tRA) treatment on body weight and IBAT parameters in mice. Feeding a vitamin A-deficient diet tended to trigger opposite effects to those of tRA treatment, namely increased body weight, IBAT weight, adiposity and leptin mRNA expression, and reduced IBAT thermogenic potential in terms of uncoupling protein 1 (UCP1) mRNA and UCP2 mRNA expression. The results emphasize the importance of retinoids as physiological regulators of brown adipose tissue.  相似文献   

19.
Summary Massive overweight is an increasing health problem and underlies several complications which in turn result in premature death. The mechanisms underlying the imbalance between energy intake and energy expenditure, that lead to obesity in humans, are still only partly understood. In rodents, heat generation and the burning of calories by the mitochondrial uncoupling protein 1 (UCP1) are important for metabolic control. However, UCP1 is exclusively expressed in brown fat which is only present in limited amounts in human adults. The recent characterization of two new uncoupling proteins, UCP2 and UCP3, may elucidate potentially important pathways for energy expenditure regulation in man. The aim of this study was to investigate whether obesity is accompanied by aberrations in UCP2 and UCP3 regulation. Expression of these two genes was examined using in situ hybridization in six lean and six obese, but otherwise healthy, men. The UCP2 expression was decreased by 28 % (p = 0.001) in the abdominal muscle of the obese subjects. No differences in UCP3 expression were observed between obese and control subjects, although there was great variation in the expression between subjects. In conclusion, these data suggest an impaired activity of the mitochondrial uncoupling protein UCP2, but probably not UCP3, in obese subjects. This may result in decreased energy expenditure and contribute to the development and maintenance of obesity. [Diabetologia (1998) 41: 935–939] Received: 5 December 1997 and in revised form: 18 February 1998  相似文献   

20.
The synthetic compound NO-1886 (ibrolipim, [4-(4-bromo-2-cyano-phenylcarbamoyl)-benzyl]-phosphonic acid diethyl ester, CAS 133208-93-2) is a lipoprotein lipase (LPL)-promoting agent that decreases plasma triglycerides, increases high-density lipoprotein cholesterol levels, and prevents fat accumulation in high fat-fed rats. However, the effect of NO-1886 on body weight, fat accumulation, and energy expenditure in ovariectomized (OVX) rats is not clear. The primary aim of this study was to ascertain whether NO-1886 ameliorated obesity in OVX rats and to examine the effects on fatty acid oxidation-related enzymes. NO-1886 decreased accumulation of visceral fat and suppressed the increase in body weight resulting from the ovariectomy. NO-1886 decreased the respiratory quotient and increased expression of the fatty acid translocase messenger RNA (mRNA) in the liver, soleus muscle, and mesenteric fat. NO-1886 also increased the expression of fatty acid-binding protein mRNA in the liver and soleus muscle and the expression of the uncoupling protein 3 (UCP3) mRNA in the heart, soleus muscle, and mesenteric fat, but not in the brown adipose tissue. Furthermore, NO-1886 did not affect UCP1 and UCP2 in brown adipose tissue. Therefore, amelioration of obesity by NO-1886 in OVX rats is possibly because of an the increased expression of fatty acid oxidation-related enzymes and UCP3, both of which are related to fatty acid transfer and fat use. Our study indicates that the LPL-promoting agent NO-1886 may be potentially beneficial in the treatment of obesity and obesity-linked health problems in postmenopausal women.  相似文献   

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