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1.
In skeletal muscle, adenosine monophosphate (AMP) is mainly deaminated by AMP deaminase. However, the C34T mutation in the AMPD1 gene severely reduces AMP deaminase activity. Alternatively, intracellular AMP is dephosphorylated to adenosine via cytosolic AMP 5'-nucleotidase (cN-I). In individuals with a homozygous C34T mutation, cN-I might be a more important pathway for AMP removal. We determined activities of AMP deaminase, cN-I, total cytosolic 5'-nucleotidase (total cN), ecto-5'-nucleotidase (ectoN) and whole homogenate 5'-nucleotidase activity in skeletal muscle biopsies from patients with different AMPD1 genotypes [homozygotes for C34T mutation (TT); heterozygotes for C34T mutation (CT); and homozygotes for wild type (CC): diseased controls CC; and normal controls CC]. AMP deaminase activity showed genotype-dependent differences. Total cN activity in normal controls accounted for 57+/-22% of whole homogenate 5'-nucleotidase activity and was not significantly different from the other groups. A weak inverse correlation was found between AMP deaminase and cN-I activities (r2=0.18, p<0.01). There were no significant differences between different groups in the activities of cN-I, whole homogenate 5'-nucleotidase and ectoN, or in cN-I expression on Western blots. No correlation for age, fibre type distribution and AMPD1 genotype was found for whole homogenate nucleotidase, total cN and cN-I using multiple linear regression analysis. There was no gender-specific difference in the activities of whole homogenate nucleotidase, total cN and cN-I. The results indicate no changes in the relative expression or catalytic behaviour of cN-I in AMP deaminase-deficient human skeletal muscle, but suggest that increased turnover of AMP by cN-I in working skeletal muscle is due to higher substrate availability of AMP.  相似文献   

2.
The C34T mutation in the gene encoding for the skeletal muscle-specific isoform of AMP deaminase (AMPD1) is a common mutation among Caucasians (i.e., one of five individuals) that can impair exercise capacity. The purpose of this study was twofold. First, we determined the frequency distribution of the C34T mutation in a group of top-level Caucasian (Spanish) male endurance athletes (cyclists and runners, n = 104). This group was compared with randomly selected Caucasian (Spanish) healthy (asymptomatic) nonathletes (n = 100). The second aim of this study was to compare common laboratory indexes of endurance performance (maximal oxygen uptake or ventilatory thresholds) within the group of athletes depending on their C34T AMPD1 genotype. The frequency of the mutant T allele was lower (P < 0.05) in the group of athletes (4.3%) compared with controls (8.5%). On the other hand, indexes of endurance performance did not differ (P > 0.05) between athlete carriers or noncarriers of the C34T mutation (e.g., maximal oxygen uptake 72.3 +/- 4.6 vs. 73.5 +/- 5.9 ml.kg(-1).min(-1), respectively). In conclusion, although the frequency distribution of the mutant T allele of the AMPD1 genotype is lower in Caucasian elite endurance athletes than in controls, the C34T mutation does not significantly impair endurance performance once the elite-level status has been reached in sports.  相似文献   

3.
Possession of the nonsense mutation in AMPD 1 C34T gene has been linked to improved survival in patients with heart failure, possibly by promoting the formation of adenosine. This mutation is known to decrease the activity of AMP-deaminase in skeletal muscle. We have found that the AMPD1 mutation decreases the activity of AMP-deaminase in the heart without changing the activity of any other enzymes of adenine nucleotide metabolism. Protective mechanism of this mutation may be thus induced by local cardiac metabolic changes.  相似文献   

4.
Possession of the nonsense mutation in AMPD1 C34T gene has been linked to improved survival in patients with heart failure, possibly by promoting the formation of adenosine. This mutation is known to decrease the activity of AMP-deaminase in skeletal muscle. We have found that the AMPD1 mutation decreases the activity of AMP-deaminase in the heart without changing the activity of any other enzymes of adenine nucleotide metabolism. Protective mechanism of this mutation may be thus induced by local cardiac metabolic changes.  相似文献   

5.
Peripheral vasculature resistance can play an important role in affecting blood pressure and the development of cardiovascular disease. A better understanding of the genes that encode vasodilators, such as adenosine, will provide insight into the mechanisms underlying cardiovascular disease. We tested whether the adenosine monophosphate deaminase-1 (AMPD1) C34T gene polymorphism was associated with the vasodilatory response to ischemia in Caucasian females aged 18-35 years. Blood samples (n = 58) were analyzed for the C34T variant and resulted in the following genotype groups: CC (n = 45) and CT (n = 13). Mean blood pressure (MBP), heart rate, and forearm blood flow (FBF) measured by venous occlusion plethysmography were measured at baseline and at 1 (peak FBF), 2 and 3 min of vasodilation during reactive hyperemia following 5 min of arm ischemia. To control for interindividual variability in baseline FBF and forearm vascular resistance (FVR) the percent change in FBF and FVR were calculated for each min. The percent decrease in FVR was significantly greater in the CT compared to the CC genotype group (-40+/-4% vs. -24+/-3%, P = 0.01) during the 2nd min of reactive hyperemia. The percent increase in FBF tended to be greater in the CT compared to the CC genotype group (+69+/-9% vs. +42+/-9%, P = 0.07) during the 2nd min of reactive hyperemia after adjustment for percent body fat. Consistent with previous findings of increased production of adenosine during exercise in individuals carrying a T allele, our findings suggest that the AMPD1 C34T polymorphism is associated with vasodilatory response to ischemia in the peripheral vasculature because individuals with the T allele had a greater vasodilatory response to ischemia.  相似文献   

6.
Possession of the C34T mutation in AMP deaminase (AMPD1) gene has been shown to be associated with attenuation of the progression of heart failure and improved survival in ischemic heart disease. In this study, we examined the frequency of the mutation in the heart with good and poor cardiac function and in healthy controls. We found that there was no difference in the frequency of the mutation between the patients with heart failure and healthy controls. However, the frequency of the mutation in the healthy donor hearts was much higher when compared to healthy controls or donors with failing hearts.  相似文献   

7.
8.
Coronary artery disease (CAD) is a major health concern and the leading cause of death in individuals with type-2 diabetes mellitus (T2DM). Glutathione peroxidase-1 (GPx-1) and NAD(P)H: quinone oxidoreductase (NQO1) are known for its broad range of detoxification. The role of functional variants of these genes in the development of various disorders is proven. Hereby, we investigated the possible role of these variants in the development of CAD in T2DM patients of South Indian population. In this case-control study, a total of 539 patients (T2DM = 241; T2DM-CAD = 298) and 285 controls were included. The C198T GPx-1 and C609T NQO1 single-nucleotide polymorphisms were analyzed by PCR-RFLP. Further, these genotypes were correlated with blood lipid profile. Regression analysis showed that GPx1-C/T genotype is associated with a 1.35-fold increase (95% CI = 1.000-1.824; P = 0.048) and GPx1-T/T genotype is associated with a 1.76-fold increase (95% CI = 1.011 to 3.066; P = 0.046) to the T2DM development. Increased odds ratio showed that NQO1-T/T genotype had a higher occurrence of CAD in diabetic patients with CAD (95% CI = 1.003-2.674, P = 0.049) than T2DM patients without CAD. The level of triglycerides alone showed significant increase for GPx-1-C/T and -T/T genotypes in Tukey's Post hoc analysis (177.1 ± 19.2 vs. 184 ± 23.5; P = 0.039 and 177.1 ± 19.2 vs. 190 ± 22.4; P = 0.006) among the patients with T2DM-CAD. Our work concludes that GPx-1 variants might contribute to the development of diabetes and both GPx-1 and NQO1 variants confirm the association of CAD in people with T2DM of South Indian population.  相似文献   

9.
Hyperhomocysteinemia is associated with increased coronary artery disease (CAD) risk. Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme in the metabolism of homocysteine and presents a common mutation (C677T) that leads to a thermolabile enzyme, mild hyperhomocysteinemia, and increased CAD risk. The C677T MTHFR mutation was studied in 772 subjects (480 Caucasian Brazilians and 292 African Brazilians) who underwent coronary angiography at the hemodynamic center of the Santa Izabel Hospital in Salvador, Bahia State, Brazil. The 677T allele frequency was increased in Caucasian Brazilians (28.1%) compared to the frequency observed in African Brazilians (18.3%; p < 0.001). In Caucasian Brazilians the frequency of the 677T homozygous genotype was increased in CAD cases (10.4%) compared to control subjects (1.4%; p = 0.014) in males but not in females. In African Brazilians the mutation was not associated with CAD in either sex. The multivariate logistic regression analysis of all the samples shows that the 677T homozygous interaction with sex was a significant CAD predictor, independent of other classical risk factors and ethnic group. The odds ratio associated with male 677T homozygotes was increased 9.2-fold (p = 0.021) compared to the 677C carriers. The present study suggests that the C677T MTHFR mutation is associated with increased CAD risk in a sex-dependent manner in Brazilians.  相似文献   

10.
Hsu LA  Ko YL  Wang SM  Chang CJ  Hsu TS  Chiang CW  Lee YS 《Human heredity》2001,51(1-2):41-45
OBJECTIVES: We sought to investigate the association between the methylenetetrahydrofolate reductase (MTHFR) gene C677T mutation and the risk of coronary artery disease (CAD), myocardial infarction (MI) and venous thrombosis (VT) in a Chinese population in Taiwan. METHODS: The subjects included 218 CAD patients, 107 VT patients, and their age- and sex-matched controls. DNA was extracted from the blood and genotypes were determined by polymerase chain reaction, restriction mapping with HinfI and gel electrophoresis. RESULTS: The distribution of MTHFR genotypes was similar in the CAD cases and controls; the genotype TT was present in 6.0% of CAD patients, as compared to 6.9% of CAD control subjects (p = 0.165; odds ratio = 0. 86; 95% confidence interval = 0.40-1.85). The frequency of the T allele was also similar in CAD cases and controls (25.5% vs. 24.8%; p = 0.788). There was no significant association between TT homozygosity and the risk of MI. The genotype distributions and the frequency of the T allele were also similar in VT cases and controls. CONCLUSIONS: Our data suggest that there is no association between the C677T mutation of the human MTHFR gene and the risk of CAD or VT among Chinese in Taiwan.  相似文献   

11.
Hudson LL  Rocca K  Song YW  Pandey JP 《Human genetics》2002,111(4-5):452-455
The cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4; CD 152) is a negative regulator of T-lymphocyte activation. Particular genotypes of the locus encoding the CTLA-4 glycoprotein have been associated with susceptibility to various autoimmune diseases. To determine their role in susceptibility to systemic lupus erythematosus (SLE), we genotyped 130 patients and 200 ethnically matched controls for allelic determinants at four polymorphic sites, viz., three in the promoter region at positions -1722 (T/C), -1661 (A/G), and -318 (C/T), and one within the first exon at position +49 (A/G), by restriction fragment length polymorphism methods. All genotype frequencies were in Hardy-Weinberg equilibrium. The genotypes at position -1722 were significantly associated with SLE. The frequency of T/T homozygotes was higher in patients than in controls (56% vs 33%, P=0.00003). Conversely, the frequencies of C/C homozygotes and C/T heterozygotes were higher in controls than in patients (15.5% vs 7%, P=0.019; 51.5% vs 37%, P=0.009). Genotypes at positions +49, -318, or -1661 were not significantly associated with SLE. These results show that allelic variation at the -1722 site influences susceptibility to SLE. This is the first report to our knowledge implicating CTLA-4 genotypes at the -1722 locus in susceptibility to any disease.  相似文献   

12.
Receptor for advanced glycation end products (RAGE) plays a role in atherosclerosis in diabetics. There are two functional polymorphisms in the promoter of the RAGE gene (-429T/C and -374T/A). The aim of this study was to look for a relationship between the -429T/C and the -374T/A gene polymorphisms of the RAGE gene and the development of coronary artery disease (CAD) in the Slovene population with type 2 diabetes of duration longer than 10 years. One hundred and sixty-eight subjects with diabetes and CAD were compared to 241 diabetic subjects without CAD. The -429T/C and the -374T/A RAGE genotype distributions in patients with CAD (-429T/C: CC: 3%, TC: 31%, TT: 66.0%; -374T/A:AA: 7.7%, TA: 48.2%, TT: 44.1%) were not significantly different from those in patients without CAD (-429 T/C: CC: 1.7%, TC: 26.1%, TT: 72.2%; -374T/A: AA: 11.2%, TA: 43.2%, TT: 45.6%). Our study failed to demonstrate an association between either the -429T/C or the -374T/A gene polymorphism of the RAGE gene and CAD in the Slovene population with type 2 diabetes of duration longer than 10 years.  相似文献   

13.
The C1431T polymorphism in peroxisome proliferator-activated receptor-γ (PPARγ) has been shown to be associated with diabetes, obesity, and metabolic syndrome. However, it is unclear whether this polymorphism is associated with coronary artery disease (CAD). Therefore, we conducted a hospital-based case–control study with 864 CAD patients and 1008 controls to explore the association between the PPARγ C1431T polymorphism and risk of CAD in Chinese Han population. Subjects with the variant genotypes (CT + TT) had a 39% decreased risk of CAD relative to CC carriers (adjusted odds ratio, 0.61; 95% confidence interval, 0.49–0.76). Our results suggested that the C1431T polymorphism was associated with a higher body mass index in both CAD patients and controls. Moreover, this polymorphism was also found to be associated with a higher HDL cholesterol level and a lower blood glucose level in CAD patients. In stratified analyses, the T allele was significantly associated with reduced risk of CAD in males, subjects with age <62 years, and non-smokers. In conclusion, the PPARγ C1431T polymorphism is associated with decreased risk of CAD in Chinese Han population.  相似文献   

14.
Although a strong correlation between type-2 diabetes and obesity has been found, no comparative analysis between diabetes and obesity has been performed with respect to mitochondrial DNA (mtDNA) polymorphisms. To test the hypothesis that certain mitochondrial single nucleotide polymorphisms (mtSNPs) might be associated with obesity or type-2 diabetes, we determined the entire sequences of the mitochondrial genomes from 96 patients with type-2 diabetes and those from 96 young obese adults by direct sequencing and compared the frequencies of mtSNPs between these two groups. A mtSNP, 8684C > T (T53I) in the mitochondrial ATP synthase subunit 6 gene (ATP6), was detected in 5 of the 96 patients with type-2 diabetes, whereas this substitution was not detected in any of the 96 young obese adults. Two mtSNPs, 3497C > T (A64V) in NADH dehydrogenase subunit 1 gene (ND1) and 1119T > C (472U > C) in the 12S rRNA gene, were detected in 5 of the 96 young obese adults, whereas these substitutions were not detected in any of the 96 diabetic patients. The 8684C > T transition associated with type-2 diabetes represents haplogroup M8a, and the 3497C > T and 1119T > C transitions predisposing to obesity represent haplogroup B4c. These results suggest that distinct mtSNPs contribute to susceptibility to type-2 diabetes or obesity, pointing out the necessity of large-scale case control studies.  相似文献   

15.
Stimulation of endogenous opiate secretion worsens circulatory dysfunction in several forms of shock, in part by inhibiting sympathetic activity. To investigate whether endogenous opiates have a similar effect in chronic heart failure (HF), we measured beta-endorphin concentrations and hemodynamic responses to naloxone infusion (2 mg/kg bolus + 2 mg.kg-1 x h-1) in six control (C) dogs and eight dogs with low-output HF produced by 3 wk of rapid ventricular pacing. The dogs with HF exhibited reduced arterial blood pressure (C, 123 +/- 4 vs. HF, 85 +/- 7 mmHg; P < 0.01) and cardiac outputs (C, 179 +/- 14 vs. HF, 76 +/- 2 ml.min-1 x kg-1; P < 0.01) and elevated plasma norepinephrine concentrations (C, 99 +/- 12 vs. HF, 996 +/- 178 pg/ml; P < 0.01) but normal beta-endorphin concentrations (C, 30 +/- 11 vs. HF, 34 +/- 12 pg/ml; P = NS). Naloxone produced similar transitory increases in blood pressure (C, 14 +/- 5 vs. HF, 26 +/- 25%) and cardiac output (C, 37 +/- 13 vs. HF, 22 +/- 15%) in both groups (both P = NS). No significant changes in norepinephrine concentration or systemic vascular resistance were observed in either group. These findings suggest that beta-endorphin secretion does not exacerbate circulatory dysfunction in chronic heart failure.  相似文献   

16.
Paternal obesity increases, while paternal exercise decreases, offspring obesity and type 2 diabetes (T2D) risk; however, no studies have determined whether a paternal high-fat (HF) diet and exercise interact to alter offspring body weight (BW), adiposity and T2D risk. Three-week-old male C57BL/6 mice were fed a normal-fat (NF) diet (16% fat) or an HF diet (45% fat) and assigned to either voluntary wheel running exercise or cage activity for 3 months prior to mating with NF-diet-fed dams. After weaning, male offspring were fed an NF or HF diet for an additional 3 months. F1 male mice whose fathers ate an HF diet had decreased % body fat accompanied by decreased gene expression of beige adipocyte marker FGF21. However, paternal HF-diet-induced reductions in F1 offspring % body fat normalized but did not reduce T2D risk. Exercise was protective against paternal HF-diet-induced insulin resistance by increasing the expression of insulin signaling (GLUT4, IRS1 and PI3K) markers in skeletal muscle resulting in normal T2D risk. When fathers were fed an HF diet and exercised, a postnatal HF diet increased beiging (PPARγ). Thus, these findings show that increases in T2D risk in male offspring when the father consumes an HF diet can be normalized when the father also exercises preconception and that this protection may occur by increases in insulin signaling potential within offspring skeletal muscle. Future studies should further determine the physiological mechanism(s) underlying the beneficial effects of exercise through the paternal lineage.  相似文献   

17.
The aim of this study was to examine the association of homozygosity for the methylenetetrahydrofolate reductase (MTHFR) C677T mutation and vitamin B12 deficiency in 360 asymptomatic individuals and to investigate forearm endothelial function in C677T homozygotes. MTHFR C677T mutation and levels of vitamin B12, folic acid, and homocysteine were measured in study participants. Frequency of homozygosity for the C677T mutation was 67/360 (18.6%). Homocysteine levels were elevated in homozygous compared with heterozygous subjects or those without the mutation (20.6 +/- 18.8 vs. 9.4 +/- 3.2 mumol/l; P < 0.0001). The number of subjects with vitamin B12 deficiency (<150 pmol/l) was significantly higher among the homozygote than the heterozygote subjects or subjects without mutation [20/67 (29.8%) vs. 27/293 (9.2%); P < 0.0001]. Homozygote subjects had 4.2 times higher probability of having B12 deficiency (95% confidence interval = 2.1-8.3). Forearm endothelial function was assessed in 33 homozygote and 12 control subjects. Abnormal endothelial function was observed in homozygous subjects and was worse in homozygote subjects with vitamin B12 deficiency. Endothelial function was normalized after B12 and folic acid treatment. We found that homozygosity for the C677T mutation is strongly associated with B12 deficiency. Coexistence of homozygosity for the C677T mutation and B12 deficiency is associated with endothelial dysfunction and can be corrected with vitamin B12 and folic acid treatment.  相似文献   

18.

Background

A number of investigators have evaluated the association between the ABCB1 polymorphism and clopidogrel responding, but the results have been inconclusive. To examine the risk of high platelet activity and poor clinical outcomes associated with the ABCB1 C3435T polymorphism in CAD patients on clopidogrel, all available studies were included in the present meta-analysis.

Methods

We performed a systematic search of PubMed, Scopus and the Cochrane library database for eligible studies. Articles meeting the inclusion criteria were comprehensively reviewed, and the available data were accumulated by the meta-analysis.

Results

It was demonstrated that the ABCB1 C3435T variation was associated with the risk of early major adverse cardiovascular events (MACE) (T vs. C OR, 1.34; 95% CI, 1.10 to 1.62; P = 0.003; TT vs. CC: OR, 1.77; 95% CI, 1.19 to 2.63; P = 0.005; CT + TT vs.CC: OR, 1.48; 95% CI, 1.06 to 2.06; P = 0.02) and the polymorphism was also associated with the risk of the long-term MACE in patients on clopidogrel LD 300 mg (T vs. C: OR, 1.28; 95% CI, 1.10 to 1.48; P = 0.001; TT vs. CC: OR, 1.59; 95% CI, 1.19 to 2.13; P = 0.002; CT + TT vs.CC: OR, 1.39; 95% CI, 1.08 to 1.79; P = 0.01). The comparison of TT vs. CC was associated with a reduction in the outcome of bleeding (TT vs. CC: OR, 0.51; 95% CI, 0.40 to 0.66; P<0.00001). However, the association between ABCB1 C3435T polymorphism and platelet activity and other risk of poor clinical outcomes was not significant.

Conclusions

The evidence from our meta-analysis indicated that the ABCB1 C3435T polymorphism might be a risk factor for the MACE in patients on clopidogrel LD 300 mg, and that TT homozygotes decreased the outcome of bleeding compared with CC homozygotes.  相似文献   

19.
The relation of Two single nucleotide polymorphisms (SNPs) at the adiponectin locus (+45T/G and +276G/T) with coronary artery disease (CAD) is controversial. The aim of the present study was to evaluate the genetic influence of the adiponectin gene polymorphisms in the development of CAD among patients with Type 2 diabetes (T2D). The adiponectin genotypes were detected by polymerase chain reaction and restriction analysis (PCR-RFLP) in our patients. Two adiponectin gene (ADIPOQ) SNPs (i.e. SNPs +45T>G and +276G>T) were genotyped in 114 Type 2 diabetic subjects with CAD, and 127 Type 2 diabetic patients without CAD. Demographic and anthropometric data along with plasma biochemistry including lipids, glycemic indices, and adiponectin were collected. There was a significant difference in the distribution of genotypes of +45T/G and +276G/T between CAD and non-CAD individuals (P < 0.05). Based on our results SNP+276G>T is associated with decreased risk of CAD after adjustment for potential confounding factors [adjusted OR = 0.39 (95%CI: 0.22–0.68); P = 0.001]. Similar findings were not observed for the +45T>G SNP. Two haplotypes 45T-276T and 45G-276T were associated with a decreased risk of CAD [adjusted OR = 0.47 (95% CI: 0.32–0.94); P = 0.03 and adjusted OR = 0.33 (95% CI: 0.13–0.83); P = 0.02 respectively]. No significant difference was observed between HOMA-IR, BMI, waist circumference, history of hypertension, HbA1C, and lipid concentrations regarding the two SNPs. In conclusion, these findings suggest that T allele of +276G>T SNP is significantly associated with decreased risk of CAD in T2D Patients. Also Haplotype analysis showed that two haplotypes 45T-276T and 45G-276T were associated with a decreased risk of CAD.  相似文献   

20.
The impact of obesity on cardiovascular disease (CVD) outcomes in patients with type 2 diabetes mellitus (T2DM) and established coronary artery disease (CAD) is controversial; whether BMI and/or waist circumference correlate with atherothrombotic risk factors in such patients is uncertain. We sought to evaluate whether higher BMI or waist circumference are associated with specific risk factors among 2,273 Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) study participants with T2DM and documented CAD (baseline data, mean age 62 years, 66% non‐Hispanic white, 71% men). Multiple linear regression models were constructed after adjusting for sex, age, race/ethnicity, US vs. non‐US site, diabetes duration, exercise, smoking, alcohol, and relevant medication use. First‐order partial correlations of BMI with risk factors after controlling for waist circumference and of waist circumference with risk factors after controlling for BMI were also evaluated. Ninety percent of the patients were overweight (BMI ≥25 kg/m2); 68% of men and 89% of women had high‐risk waist circumference measures (≥102 and ≥88 cm, respectively). BMI and waist circumference, in separate models, explained significant variation in metabolic (insulin, lipids, blood pressure (BP)) and inflammatory/procoagulation (C‐reactive protein, PAI‐1 activity and antigen, and fibrinogen) risk factors. In partial correlation analyses BMI was independently associated with BP and inflammatory/procoagulation factors, waist circumference with lipids, and both BMI and waist circumference with insulin. We conclude that, in cross‐sectional analyses, both BMI and waist circumference, independently, are associated with increased atherothrombotic risk in centrally obese cohorts such as the BARI 2D patients with T2DM and CAD.  相似文献   

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