Association between senescence-related uncoupling protein 2 gene polymorphisms and abdominal obesity in Japanese subjects: The Tanno and Sobetsu study

Background:   Uncoupling protein 2 ( UCP2 ) plays an important role in regulating body weight, energy expenditure and insulin secretion. UCP2 is upregulated in white fat in response to fat feeding, and negatively controls insulin secretion. UCP2 also has a function that protects cells from apoptosis and oxidative stress, which shows UCP2 might be a senescence-related gene. Previously, UCP2 -866G/A polymorphism in the promoter region has been reported to alter adipose tissue mRNA expression and is associated with obesity in Caucasians.
Methods:   In this study, we investigated the association between this polymorphism and obesity, insulin secretion and hypertension in the general Japanese population.
Results:   The allele frequency of UCP2 -866G/A polymorphism was significantly higher in Japanese subjects compared to Caucasians. It revealed that subjects only in the obese group with the AA type of UCP2 -866G/A polymorphism had significantly higher levels of body mass index (BMI) and waist circumference. Multiple logistic regression analysis showed that this polymorphism was independently associated with waist circumference. This positive association remained in the analysis of the subgroup younger than 65 years, but not in the older group. This polymorphism did not affect levels of insulin and homeostasis model assessment ratio (HOMA-R).
Conclusions:   These results suggest that the AA type of UCP2 -866G/A polymorphism is related to abdominal obesity, which indicates the possible role of this polymorphism in causing metabolic syndromes.     

解偶联蛋白2基因-866G／A多态性与2型糖尿病代谢表型相关性的核心家系研究

目的探讨解偶联蛋白2（UCP2）基因-866G／A多态性与2型糖尿病及相关代谢异常性状的关系。方法2005年5月至2007年9月,通过先证者引荐法在北京市房山区农村社区共募集287个2型糖尿病家系。应用聚合酶链反应结合限制性片段长度多态性方法进行UCP2基因-866（3／A多态性鉴定。采用非参数同胞对连锁分析和以家庭为基础的关联分析进行基因多态性与表型的相关性检验。结果2型糖尿病家系人群中UCP2基因-866G／A多态性AA、GA和GG三种基因型频率分别为19．7％、52．9％和27．4％,A、G等位基因频率分别为0．461和0．539;非参数连锁分析未发现阳性结果;以家庭为基础的关联分析发现G等位基因具有传递优势,与代谢综合征和中心性肥胖两表型相关（Z=2．28、2．01,均P〈0．05）,AA基因型也与上述两表型相关（Z=-2．22、-2．01,均P〈0．05）。结论UCP2基因-866G／A多态性与2型糖尿病家系人群的代谢综合征和中心性肥胖相关,与2型糖尿病及血脂异常无关。     

Association of the C825T polymorphism of the G-protein beta3 subunit gene with hypertension, obesity, hyperlipidemia, insulin resistance, diabetes, diabetic complications, and diabetic therapies among Japanese

A C825T polymorphism of the gene encoding the G-protein beta3 subunit (GNB3) is associated with increased intracellular signal transduction. We know that this C825T polymorphism may influence hypertension and obesity. In whites, the C825T polymorphism has been reported to induce hypertension, obesity, and diabetic nephropathy. Thus, we investigated how genetic variation in the GNB3 gene is associated with hypertension, obesity, insulin resistance, diabetes, diabetic complications, and diabetic therapies in 427 Japanese subjects with type 2 diabetes mellitus and in 368 Japanese subjects who underwent general health examinations. The frequency of the GNB3 gene polymorphism was 0.48 and 0.47 in subjects with diabetes and in those who had general health examinations, respectively. The amount of hyperlipidemia of the CT allele was significantly lower than the amount in the CC allele in the Japanese subjects with diabetes. Our results suggest that the C825T polymorphism influences lipid metabolism and is not associated with hypertension, obesity, insulin resistance, diabetes, diabetic complications, or diabetic therapies.     

Phenotypic characterization of the beta3-adrenergic receptor mutation and the uncoupling protein 1 polymorphism in Japanese men.

The Trp64Arg mutation of the beta3-adrenergic receptor (beta3AR) gene and A to G polymorphism of the uncoupling protein 1 (UCP1) gene are reported to be associated with weight gain, and both have been shown to have an additive effect on weight gain in Caucasians. Racial differences have also been noted in the beta3AR mutation; however, the effect of UCP1 polymorphism on body weight is not obvious in the Japanese. Thus, we investigated the association of genetic variations in beta3AR and UCP1 genes and the additive effects of these two genes in 214 Japanese men. The frequency of the Trp64Arg allele was 0.19, and serum triglyceride was significantly higher in Arg64 homozygotes versus Trp64 homozygotes. The frequency of the G allele was 0.51, and the body mass index (BMI) was significantly higher in subjects with the G allele (GG homozygotes and AG heterozygotes) versus those without it (AA homozygotes). The beta3AR mutation and UCP1 polymorphism were not found to have additive effects, and they were not related to glucose tolerance patterns and insulin resistance. Our results suggest that the beta3AR mutation is associated with hypertriglyceridemia and the UCP1 polymorphism may be a weak contributing factor to obesity in Japanese men.     

Variants of uncoupling protein-2 gene and obesity: interaction with peroxisome proliferator-activated receptorgamma2

OBJECTIVE: To analyse the association of the UCP2 gene, alone or in combination with the PPARgamma2 gene, with obesity. DESIGN: Cross-sectional, case-control study. STUDY POPULATION: From a working population of 4500 Italian Caucasian employees of the Italian telephone company participating in a firm-sponsored health screening programme, we selected all those with obesity [n = 122; body mass index (BMI) > or = 30 kg/m2]. For each case, three nonobese age- and sex-matched individuals were selected as controls from the same population (n = 374). Included in the study were also 76 severely obese (BMI > or = 40 kg/m2) patients consecutively admitted to the obesity clinic of the department. Diabetic individuals were excluded. MEASUREMENTS: The -866G/A UCP2 and the Pro12Ala PPARgamma2 polymorphisms were determined on genomic DNA of the studied individuals. Several metabolic and anthropometric measures were also obtained, like plasma glucose, insulin, triglycerides, total cholesterol, high-density lipoprotein (HDL) cholesterol and BMI. RESULTS: BMI, plasma glucose, insulin, triglycerides, total and HDL cholesterol were not significantly different in carriers and noncarriers of the -866G/A variant. No significant association was observed between the -866G/A UCP2 gene polymorphism and moderate or severe obesity. This was also observed when the UCP2 polymorphism was analysed in combination with the PPARgamma2 polymorphisms. CONCLUSIONS: The -866G/A variants of the UCP2 gene are not associated with either obesity or other features of the metabolic syndrome in the studied groups of the Italian population. This negative finding is not modified after a combined analysis of the UCP2 polymorphism and the Pro12Ala polymorphism of PPARgamma2.     

The common -866G/A polymorphism in the promoter region of the UCP-2 gene is associated with reduced risk of type 2 diabetes in Caucasians from Italy

Uncoupling protein-2 (UCP2) regulates insulin secretion and may play an important role in linking obesity to type 2 diabetes (T2D). Previous studies of the role of the UCP2 promoter -866G/A single nucleotide polymorphisms (SNP) in T2D have given opposite results. We tested the distribution of the -866G/A SNP in 746 T2D patients and 327 healthy unrelated Caucasians from Italy. We also tested for an effect of the P12A variant of the peroxisomal proliferator-activated receptor-gamma 2 (PPAR gamma 2) gene on diabetes risk given by the UCP2 SNP. Compared with -866G/G carriers, a progressively reduced (P = 0.01) risk of T2D was observed in -866G/A and -866A/A subjects, with the latter showing an approximately 50% risk reduction [odd ratio (OR), 0.51; 95% confidence interval (CI), 0.3-0.8; P = 0.003]. Conversely, the -866G/G genotype was associated with increased risk (OR, 1.31; 95% CI, 1.01-1.71). Overall, the population risk attributable to the UCP2 -866G/G genotype was about 12%. After stratifying for the PPAR gamma 2 polymorphism, the increased risk conferred by the UCP2 G/G genotype was still evident among P12/P12 homozygous subjects (n = 801; OR, 1.38; 95% CI, 1.04-1.83), but seemed to disappear among the X12/A12 subjects (i.e. P12/A12 heterozygous or A12/A12 homozygous subjects; n = 137; OR, 0.87; 95% CI, 0.40-1.91). Whether this apparent difference is entirely due to the different number of carriers of the two PPAR gamma 2 genotypes is a likely possibility that deserves deeper investigation. In conclusion, in our population, the -866G/A SNP is associated with T2D. Additional studies in larger samples are needed to investigate the possibility of a concomitant effect of modifier genes such as PPAR gamma 2.     

The Trp64Arg polymorphism of the beta3-adrenergic receptor gene and obesity in Chinese subjects with components of the metabolic syndrome

BACKGROUND: In regions such as Hong Kong, rapid economic development has led to lifestyle alterations characterized by increases in energy and fat intake and reduction in physical activity. These changes have been associated with a dramatic increase in the prevalence of diabetes and related diseases of the metabolic syndrome. OBJECTIVE: To investigate if a common polymorphism (Trp64Arg) of the beta3-adrenergic receptor gene, previously implicated as predisposing to type 2 diabetes mellitus or obesity in other populations, has a role in the apparent susceptibility of Hong Kong Chinese to diabetes and related disorders. METHOD: A PCR-based protocol was used to genotype 802 Southern Chinese subjects who were either healthy or had one or more of the metabolic disorders including diabetes, hypertension or dyslipidaemia. RESULTS: The frequencies of the mutant A allele (12.7%) and AA genotype (1.7%) did not differ, by the chi2 test, in any patient group with diabetes, hypertension or dyslipidaemia, alone or in combination, compared to healthy controls. Using the t-test in the 802 subjects, those carrying the mutant A allele had evidence of increased obesity with a significantly (all P<0.05) higher body mass index (BMI, kg/m2) and also lower HDL-cholesterol. BMI was also elevated in subjects with the A allele in the separate groups with diabetes, dyslipidaemia or hypertension. Stepwise multiple regression showed this polymorphism to be an independent predictor of BMI. CONCLUSION: These data do not support any direct involvement of the Trp64Arg polymorphism in the development of diabetes, hypertension or dyslipidaemia in Chinese subjects, but do suggest a relationship with obesity.     

Variation of the fatty acid binding protein 2 gene is not associated with obesity and insulin resistance in Japanese subjects.

An alanine to threonine substitution at codon 54 of the fatty acid binding protein 2 (FABP2) gene has been associated with insulin resistance in Pima Indians and with obesity in aboriginal Canadians. We investigated whether this polymorphism contributes to obesity and insulin resistance in 258 Japanese subjects. Thirty-six subjects (13.9%) were homozygous for the Thr54 allele, 106 (41.1%) were heterozygous for the Ala54/Thr54 allele, and 116 (45.0%) were homozygous for the Ala54 allele. The frequency of the Thr54 allele was 0.34 and did not differ significantly between men and women. The incidence of non-insulin-dependent diabetes mellitus (NIDDM) was not different among the three genotypes. The variation at codon 54 of the FABP2 gene was not associated with obesity, hypertension, dyslipidemia, hyperuricemia, or hyperinsulinemia. These results suggest that the polymorphism at codon 54 of the FABP2 gene is not a major contributing factor to obesity and insulin resistance in Japanese subjects.     

The Trp64Arg beta3-adrenergic receptor amino-acid variant is not associated with overweight and type 2 diabetes mellitus in Polish population.

The Trp64Arg amino-acid variant of the beta3 adrenoreceptor gene may be associated with a genetic predisposition to human obesity and related disorders, including type 2 diabetes mellitus. This relationship has been reported in various ethnic groups, however it was not extensively studied in Polish population. Therefore, the aim of the study was to investigate the association of Trp64Arg polymorphism of the beta3 adrenergic receptor gene with overweight and type 2 diabetes mellitus in polish subjects. The Trp64Arg polymorphism was determined by PCR-based MspI restriction fragment length polymorphism (PCR-RFLP). The study population consisted of 358 subjects, among whom 200 were diagnosed as overweight (BMI > 27 kg/m (2)). Among overweight subjects 111 presented with type 2 diabetes mellitus and 89 with normal glucose metabolism. All study participants were unrelated Caucasians and inhabited the city of Lodz, Poland. The frequency of the Arg allele did not differ significantly between overweight and normal weight patients (13 % vs. 11 %, OR 1.17, CI 0.74 - 1.85). The same applied to overweight diabetic patients vs. overweight patients without diabetes mellitus (13 % vs. 13 %, OR 0.97, CI 0.54 - 1.76). The obtained results suggest no association between Trp64Arg polymorphism of the beta3-AR gene and the incidence of overweight and type 2 diabetes mellitus in Polish population.     

Preproghrelin Leu72Met polymorphism in patients with type 2 diabetes mellitus

OBJECTIVES: The association between the Leu72Met polymorphism of the preproghrelin gene and diabetic complications was examined in patients with type 2 diabetes mellitus. SUBJECTS AND METHODS: A total of 258 patients with type 2 diabetes mellitus and 522 control subjects were screened. Genotypes were determined by polymerase chain reaction technique. The diagnosis of coronary heart disease was based on clinical and ECG criteria. Laboratory analyses were carried out in the hospital laboratory. RESULTS: No differences in the genotype distributions and allele frequencies of the preproghrelin Leu72Met polymorphism were found between type 2 diabetes mellitus patients and controls. The polymorphism was not associated with macro- or micro-angiopathy or hypertension. However, Leu72Met polymorphism was associated with serum creatinine (P = 0.006) and lipoprotein(a) [Lp(a)] levels (P = 0.006) with Leu72Leu subjects showing the highest values. This association was observed only amongst diabetic group. CONCLUSIONS: The Leu72Met polymorphism of the preproghrelin gene was not related to cardiovascular disease in type 2 diabetes mellitus patients. Leu72Met polymorphism was, however, associated with serum creatinine and Lp(a) levels in diabetic patients. The mechanism might be associated with a possible change in ghrelin product and its somatotropic effect.     

Cardiovascular risk in healthy men and markers of oxidative stress in diabetic men are associated with common variation in the gene for uncoupling protein 2.

BACKGROUND: Oxidative stress reduces total antioxidant status (TAOS) and is implicated in atherogenesis. Mitochondrial uncoupling protein 2 (UCP2) negatively regulates reactive oxygen species generation. The UCP2 gene demonstrates a common functional promoter variant (-866G>A). METHODS AND RESULTS: Amongst 465 diabetic men (age 61.7 +/- 13.3 years), an association of the UCP2-866A allele with significantly lower TAOS in those without CHD was even more pronounced in those with CHD (TAOS 30.1 +/- 16.1% vs. 41.6 +/- 12.4% for AA vs. GG; P=0.016). In a sample of 20 diabetic men selected for homozygosity for the UCP2-866G>A variant, matched for baseline characteristics, plasma markers of oxidative stress in those with CHD were significantly higher in AA genotype men (TAOS 31.7 +/- 7.3% vs. 52.6 +/- 6.3%; P=0.001 and F2-isoprostanes 220.6 +/- 37.2 pg ml(-1) vs. 109.9 +/- 51.1 pg ml(-1); P=0.005 for AA vs. GG). Amongst 2695 healthy men (age 56.1 +/- 3.5 years) prospectively studied for a median 10.2 years, AA homozygotes had a highly significant doubling in CHD risk after adjustment for established risk factors (HR 1.99 [1.37-2.90]; P=0.002). Risk associated with this genotype was substantially increased by the presence of other risk factors (obesity, hypertension and diabetes). CONCLUSIONS: This study provides the first in vivo evidence of a role for UCP2 in modifying oxidative stress and CHD risk in humans.     

The A3 allele of the HLA-DQA1 locus is associated with susceptibility to type 1 diabetes in Japanese.

Analysis of the frequencies of class II HLA-DR and HLA-DQ alleles by serological and DNA typing in 49 Japanese patients with type 1 (insulin-dependent) diabetes and 31 Japanese controls indicates the following. (i) Susceptibility is more strongly associated with the HLA-DQ subregion than with the HLA-DR subregion. (ii) Of the class II alleles detected, the A3 allele of the DQA1 locus was the most strongly associated with disease. Ninety-six percent of the patients were positive for the A3 allele compared to 53% of the controls (P = 0.001; relative risk = 19.7; confidence limits = 3.72-188.64). (iii) The DQw8 allele of the DQB1 locus, which is associated with susceptibility to type 1 diabetes in Caucasians and Blacks, was not increased in frequency in Japanese patients (22%) versus controls (19%). (iv) Asp-57-encoding DQB1 alleles are associated with reduced susceptibility to type 1 diabetes in Caucasians. The major predisposing haplotypes in Japanese are DR4 and DR9. By DNA sequence analysis, both of these Japanese haplotypes have Asp-57-encoding DQB1 alleles. Oligonucleotide dot blot analysis showed that all, except 1, of the 49 Japanese patients and all of the 31 controls have at least one Asp-57-encoding DQB1 allele. In addition, 40% of the patients were homozygous for Asp-57-encoding DQB1 alleles versus 35% of the controls. The high frequencies of Asp-57-encoding DQB1 alleles in this ethnic group may account for the rarity of type 1 diabetes in Japan.     

二乙基对硝基苯磷酯酶2基因G/A148多态性与2型糖尿病及血脂的关系

目的：了解二乙基对硝基苯磷酯酶（PON）2基因G／A148多态性与中国北方地区人群2型糖尿病的相关性及其与血脂等的关系。方法：采用配偶对的病例－对照研究设计，用聚合酶链反应（PCR）－长度多态性的方法检测PON2基因G／A148多态性。结果：PON2基因G／A148多态性的基因型频率和等位基因频率在2型糖尿病组和对照组间差异无显著性意义。与非肥胖、无G等位基因相比，肥胖无G等位基因时，发生2型糖尿病的危害险度（OR）值为2．04；肥胖有G等位基因时，OR增至3．18。在对照人群中，含G等位基因组的总胆固醇（TC）、低密度脂蛋白（LDL）及载脂蛋白B（ApoB)水平均比AA基因型组高。G等位基因对高脂血症的OR为2．48，P＝0．5。结论：在中国北方地区人群中PON2基因G／A148多态性与肥胖有协同促进2型糖尿病发生的作用。在非糖尿病人群中，此多态性与总胆固醇等血脂水平显著相关。     

Association of LMNA 1908C/T polymorphism with cerebral vascular disease and diabetic nephropathy in Japanese men with type 2 diabetes

OBJECTIVE: The LMNA 1908C/T polymorphism has been reported to be associated with dyslipidaemia, metabolic syndrome, adipose tissue metabolism and obesity phenotypes, suggesting that this polymorphism presents an increased risk of atherosclerosis and vascular diseases. However, there have been no previous reports on the relationship between the LMNA 1908C/T polymorphism and vascular diseases. The aim of this study therefore was to investigate the association between the LMNA 1908C/T polymorphism and the prevalence of vascular disease in Japanese patients with type 2 diabetes. DESIGN: A cross-sectional, hospital-based study of diabetic complications with an LMNA gene background. PATIENTS: One hundred and sixty-six Japanese men with type 2 diabetes. Measurements LMNA 1908C/T polymorphism (by polymerase chain reaction restriction fragment length polymorphism, PCR-RFLP); diabetic retinopathy (by standard fundus photography); diabetic nephropathy (by urinary albumin excretion rate); diabetic neuropathy (by signs, symptoms and/or nerve conduction velocity); coronary heart disease (by symptoms of typical chest pain and/or history of myocardial infarction, and ischaemic electrocardiographic alteration and/or coronary artery bypass graft surgery); cerebral vascular disease (by ultrasonography, computed tomography and/or magnetic resonance imaging). RESULTS: Carriers of the LMNA 1908T allele manifested a significantly higher prevalence of diabetic nephropathy and cerebral vascular disease than carriers of the C allele. Multiple regression analysis showed that the LMNA 1908T allele tended to be associated with cerebral vascular disease, but was independent of age, hypertension, total cholesterol or triglyceride [odds ratio (OR) 7.03, P=0.0611]. Similarly, the LMNA 1908T allele showed a significant association with diabetic nephropathy, not independent of total cholesterol or triglyceride. CONCLUSIONS: The LMNA 1908C/T polymorphism plays an important role in the development of cerebral vascular disease and diabetic nephropathy in Japanese men with type 2 diabetes.     

Mitochondrial 5178A/C genotype is associated with acute myocardial infarction.

A single nucleotide polymorphism of mitochondrial 5178A/C, causing a Met to Leu replacement within the NADH dehydrogenase subunit, is reported to be associated with longevity. The purpose of the present study was to assess the contribution of mitochondrial polymorphisms, particularly the 5178A/C genotype, to the susceptibility to acute myocardial infarction (AMI) in a Japanese study population. There were 4 groups: 150 patients with AMI, 150 with essential hypertension, 100 with diabetes mellitus, and 150 subjects matched for age and sex who served as the control group. Mitochondrial 5178A/C was detected by the polymerase chain reaction restriction fragment length polymorphism method. The allelic frequency of 5178C was significantly higher in the AMI group than in the control group, and this difference was more marked in younger patients. There were differences in allelic frequencies among the essential hypertension group, diabetes mellitus group and control group, but a higher frequency of the C allele was seen in the AMI group compared with the essential hypertension and diabetes mellitus groups. This particular polymorphism was found to be associated with development of AMI, especially in younger patients and constitutes a new risk factor for AMI.     

Genetic variation in UCP2 (uncoupling protein-2) is associated with energy metabolism in Pima Indians

Aims/hypothesis Uncoupling protein-2 (UCP2) is thought to play a role in insulin secretion and the development of obesity. In this study, we investigated the effects of genetic variation in UCP2 on type 2 diabetes and obesity, as well as on metabolic phenotypes related to these diseases, in Pima Indians.Methods The coding and untranslated regions of UCP2, and approximately 1 kb of the 5 upstream region, were sequenced in DNA samples taken from 83 extremely obese Pima Indians who were not first-degree relatives.Results Five variants were identified: (1) a –866G/A in the 5 upstream region; (2) a G/A in exon 2; (3) a C/T resulting in an Ala55Val substitution in exon 4; and (4, 5) two insertion/deletions (ins/del; 45-bp and 3-bp) in the 3 untranslated region. Among the 83 subjects whose DNA was sequenced, the –866G/A was in complete genotypic concordance with the Ala55Val and the 3-bp ins/del polymorphism. The G/A polymorphism in exon 2 was extremely rare. To capture the common variation in this gene for association analyses, the –866G/A variant (as a representative of Ala55Val and the 3-bp ins/del polymorphism) and the 45-bp ins/del were also genotyped for 864 full-blooded Pima Indians. Neither of these variants was associated with type 2 diabetes or body mass index. However, in a subgroup of 185 subjects who had undergone detailed metabolic measurements, these variants were associated with 24-h energy expenditure as measured in a human metabolic chamber (p=0.007 for the 45-bp ins/del and p=0.03 for the –866G/A after adjusting for age, sex, family membership, fat-free mass and fat mass).Conclusions/interpretation Our data indicate that variation in UCP2 may play a role in energy metabolism, but this gene does not contribute significantly to the aetiology of type 2 diabetes and/or obesity in Pima Indians.     

Cannabinoid Receptor 1 (CNR1) 4895 C/T Genetic Polymorphism was Associated with Obesity in Japanese Men

Aim: The aim of this study was to investigate the association of cannabinoid receptor 1 (CNR1) 4895 C/T gene polymorphism with obesity and obesity-related cardiovascular disease (CVD) risk factors in Japanese.Method: This study included 1,452 Japanese (678 men and 774 women, aged 25 to 74) from rural communities in Shimane Prefecture, Japan.Results: The frequency of the C minor allele of CNR1 4895 C/T polymorphism was 47%. In men, the CC genotype carriers showed significantly greater body mass index (BMI) and waist circumference (WC) values than T allele carriers, even after adjusting for age and medications for hypertension, dyslipidemia and type 2 diabetes. The frequency of obesity (BMI ≥25 kg/m(2)) in CC genotype carriers was significantly greater than in T allele carriers (31.8% vs 21.5%), but the frequency of central obesity (WC ≥85 for men and WC ≥90 cm for women) was not significant by CNR1 4895 C/T genotype. CC genotype carriers of CNR1 4895 C/T showed, in logistic regression analysis, significantly greater odds for obesity than T allele carriers, even after adjustment for age and the above-mentioned medications. Systolic blood pressure (SBP) values were also significantly different between the CC genotype and T allele carriers after controlling for age, medications for hypertension, dyslipidemia, and type 2 diabetes, and BMI or WC.Conclusion: This study supports the association of CNR1 4895 C/T with interindividual differences in obesity in men.     

Screening for variants of the uncoupling protein 2 gene in Japanese patients with non-insulin-dependent diabetes mellitus.

We examined genetic mutations in the coding regions of the uncoupling protein 2 (UCP2) gene in 100 patients with non-insulin-dependent diabetes mellitus (NIDDM). The sequences of each exon-intron boundary were detected by polymerase chain reaction (PCR) using specific primer pairs designed in the cDNA sequence of UCP2 and a cycle-sequence method. Using the specific primer pairs in the intron 5'- or 3'-untranslated region, each exon with its exon-intron boundaries was amplified with the PCR method, and the PCR products were analyzed using a single-strand conformation polymorphism (SSCP) method. One nucleotide substitution in exon 4 was found, which exchanged Ala (gcc) at position 55 of the amino acid sequence for Val (gtc), previously reported in Denmark by Urhammer et al in 1997. The polymorphism was reanalyzed in all patients and 120 normal subjects using a PCR-restriction fragment length polymorphism method. There was no difference in the genotype distribution between patients and normal subjects, and our genotype distribution was similar to the Danish study. Furthermore, there were no clinical differences between genotype groups among the patients. No other mutation including the exon-intron boundary was found in these patients. Genetic mutations of UCP2 may not be commonly associated with obesity or diabetes in Japanese subjects.     

An uncoupling protein 3 gene polymorphism associated with a lower risk of developing Type II diabetes and with atherogenic lipid profile in a French cohort

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]     

Analysis of the insulin-sensitive phosphodiesterase 3B gene in type 2 diabetes

We screened for mutations in the gene of insulin-sensitive phosphodiesterase 3B (PDE3B), which regulates antilipolytic actions of insulin via reduction of intracellular cyclic AMP levels, in Japanese patients with type 2 diabetes mellitus and lipoatrophic diabetes mellitus using single-stranded conformation polymorphism analysis and Southern analysis and investigated frequencies of variable number of tandem repeats. A silent polymorphism at the Arg463 codon (AGG-->AGA) in exon 4 was identified after examining all 16 exons and exon-intron splicing junctions of the gene. This polymorphism was found in 53 of 100 subjects with type 2 diabetes mellitus, 2 of 5 lipoatrophic diabetic patients and 24 of 50 control subjects, without any significant difference in allele frequency between groups. An EcoRI restriction fragment length polymorphism was identified in patients with type 2 diabetes mellitus and control subjects, again with no differences in occurrence. The allelic distribution of two polymorphic tandem repeats sequences in introns 5 and 12 of the gene did not differ significantly between patients with type 2 diabetes mellitus and control subjects. In conclusion, alterations in the PDE3B gene are unlikely to contribute importantly to the pathogenesis of type 2 diabetes mellitus or lipoatrophic diabetes mellitus in Japan.