内皮型一氧化氮合成酶基因Glu298Asp多态性与糖尿病肾脏病的关系

目的探讨内皮型一氧化氮合成酶（eNOS）基因Glu298Asp多态性与糖尿病肾脏病（DIcD）的关系。方法采用聚合酶链反应（PCR）后限制性内切酶消化技术,对在我院就诊的326例中国汉族2型糖尿病（T2DM）患者和215名健康体检者进行Glu298Asp基因型分析。根据尿白蛋白排泄率（UAER）水平将T2DM患者分为3组：UAER正常组（DM组）102例,微量白蛋白尿组（MAU组）81例,临床肾病组（DKD组）143例。选择同时期本院健康体检者215名为对照组。用多因素Logistic回归分析法判定DKD的独立危险因素。结果DKD组与对照组Glu298Asp基因型频率分布存在显著性差异（GG72．72％、GT26．57％、TT0．70％比GG83．41％、GT16．10％、TT0．49％,P=0．019）,而DM组和MAU组则与对照组无差异（P〉0．05）。Logistic回归分析显示,年龄、平均动脉压、GT基因型是DKD发生的独立危险因素。结论eNOS Glu298Asp基因与中国汉族T2DM患者DKD具有相关性。     

Associations between endothelial nitric oxide synthase polymorphisms and risk of diabetic nephropathy: an updated meta-analysis

Abstract

Background: Genetic polymorphism of endothelial nitric oxide synthase (eNOS) has been implicated in the risk of diabetic nephropathy (DN), but the published findings were inconsistent. We performed a comprehensive meta-analysis to derive a more precise estimation of the association between genetic polymorphisms of eNOS and the risk of DN. Methods: Six online database were researched on the associations between polymorphisms of eNOS (T786C, G894T, 4b/4a) and DN risk. PRISMA statement and Hardy–Weinberg equilibrium assessment were used in this report. Odds ratio and 95% confidence interval were estimated based on the following genetic contrast/models: allelic model, dominant model, recessive model and co-dominant model. The publication bias and sensitivity analysis were also performed to guarantee the statistical power. Results: A total of 49 case–control studies with 11,990/9754/5131 participants for DN/DM/HC group were eligible for meta-analysis (7/25/31 studies for T786C/G984T/4b/a). For the eNOS-T786C, C allele showed a weak association between C allele and DN risk in DN/T2DM group. For eNOS-G894T, there was an association between T allele and DN risk in the global, Asian and African population in DN/T2DM group. For the eNOS-4b/4a, 4a allele was found contributing significantly to increased DN risk in the global population. Conclusion: Our comprehensive meta-analysis suggests that three polymorphisms of eNOS may be the increased risk factors of DN development, especially in Asian population and T2DM group.     

Association of endothelial nitric oxide synthase gene intron 4 polymorphism with end-stage renal disease

BACKGROUND: Nitric oxide (NO) released from endothelial cells is related to the maintenance of physiological vascular tone. The impairment of endothelial NO generation brought about by gene polymorphism is considered one of the deterioration factors in progressive renal disease. In the endothelial nitric oxide synthase (eNOS) intron 4 polymorphism, the presence of the aa genotype has been associated with cardiovascular and renal disease. The aim of this study was to investigate the presence of eNOS gene intron 4 polymorphism in patients with end-stage renal disease (ESRD). METHODS: A total of 114 patients and 94 controls were studied. DNA specimens were extracted from blood and amplified by polymerase chain reaction. The alleles were separated by agarose gel electrophoresis. Genotype distribution and allele frequencies were compared between groups using the chi-squared test. RESULTS: Statistical analysis revealed that the frequency of the eNOS4 genotype aa was significantly different in ESRD patients and in controls (P=0.016, OR=2.07, CI 95%: 1.14-3.74). There was also a statistically significant difference between ESRD patients and controls regarding allele carriers (P=0.004; OR=2.26; CI 95%: 1.29-3.96). When the frequencies of allele carriers in the diabetic nephropathy group and in the control group were compared, a significant difference was found (P=0.034, OR=2.28; CI 95%: 1.04-5.00). CONCLUSION: This study showed a strong correlation between eNOS4a polymorphism and end-stage renal disease.     

Effect of combination endothelial nitric oxide synthase gene therapy and sildenafil on erectile function in diabetic rats

Erectile dysfunction associated with diabetes mellitus is caused in part by disordered endothelial smooth muscle relaxation, neuropathy, and a decrease in cavernosal nitric oxide synthase (NOS) activity. The purpose of this study was to determine whether a combination of sildenafil and adenoviral gene transfer of endothelial NOS (eNOS) could enhance the erectile response in diabetic rats. Five groups of animals were utilized: (1) age-matched control rats, (2) streptozotocin (STZ)-induced diabetic rats (60 mg/kg i.p.), (3) STZ-rats + sildenafil (2 mg/kg i.v.), (4) STZ-rats transfected with AdCMVbetagal or AdCMVeNOS, and (5) STZ-rats transfected with AdCMVeNOS +sildenafil (2 mg/kg i.v.). At 2 months after i.p. injection of STZ, groups 4 and 5 were transfected with the adenoviruses and 1-2 days after transfection, all animals underwent cavernosal nerve stimulation (CNS) to assess erectile function. Cyclic 3',5'-guanosine monophosphate (cGMP) levels were assessed in the cavernosal tissue. STZ-diabetic rats had a significant decrease in erectile function as determined by the peak intracavernosal pressure (ICP) and total ICP (area under the erectile curve; AUC) after CNS when compared to control rats. STZ-diabetic rats+AdCMVeNOS had a peak ICP and AUC, which were similar to control animals. STZ-diabetic rats administered sildenafil demonstrated a significant increase in peak ICP at the 5 and 7.5 V settings, while the AUC was significantly increased at all voltage (V) settings. The increase in both ICP and AUC of STZ-diabetic rats transfected with AdCMVeNOS at all V settings was greater than STZ-diabetic rats transfected with AdCMVbetagal. STZ-diabetic rats transfected with AdCMVeNOS and administered sildenafil had a significant increase in total ICP that was greater than eNOS gene therapy alone. Cavernosal cGMP levels were significantly decreased in STZ-diabetic rats, but were increased after transfection with AdCMVeNOS to values greater than control animals. In conclusion, overexpression of eNOS and cGMP in combination with sildenafil significantly increased both the peak ICP and total ICP to CNS in the STZ-diabetic rat, which was similar to the response observed in control rats. Moreover, the total erectile response was greater in STZ-diabetic rats receiving eNOS gene therapy plus sildenafil than STZ-rats receiving sildenafil or eNOS gene therapy alone.     

Noncholinergic penile erection in mice lacking the gene for endothelial nitric oxide synthase.

With the current understanding that nitric oxide (NO) mediates penile erection, the endothelial isoform of NO synthase (eNOS) has been implicated in this function. We undertook this study applying transgenic mice with targeted deletion of the eNOS gene (eNOS-/- mice) as an experimental approach to evaluate the importance of eNOS in cholinergically stimulated erectile function in vivo. Combined pharmacostimulation with intracavernosal carbachol (3 ng) administration and submaximal cavernous nerve (CN) electrical stimulation (16 Hz, 5 millisecond, 1 V) simultaneous with intracavernosal pressure (ICP) monitoring, and both biochemical assay of NO synthase activity and Western blot analysis of eNOS protein content in penile tissue, were performed on eNOS-/- mice and wild-type controls. Combined intracavernosal carbachol administration and submaximal CN electrical stimulation raised the recorded ICP, elicited by CN electrical stimulation alone in wild-type mice (from 35.7 +/- 2.7 to 48.1 +/- 5.5 mm Hg, P < .05) but not in eNOS-/ - mice (from 54.9 +/- 6.3 to 51.0 +/- 9.5 mm Hg, not significant [NS]). Pretreatment with the nonselective nitric oxide synthase inhibitor nitro-L-arginine methyl ester (L-NAME; 100 mg intracavernosally) blocked electrically stimulated ICP responses in eNOS-/- mice to baseline levels (37.8 +/- 4.4 vs 12.7 +/- 4.0 mm Hg, P < .05). In penes of eNOS-/- mice, approximately 60% NO synthase activity of wild-type penis levels was retained (NS), and eNOS protein was absent. We concluded that eNOS-/- mice preserve erectile function on the basis of a noncholinergic but NO-dependent mechanism and that eNOS physiologically mediates penile erection under cholinergic stimulation.     

内皮细胞型一氧化氮合酶基因多态性与前列腺癌的相关性研究

目的 探讨内皮细胞型一氧化氮合酶(ecNOS)基因多态性与前列腺癌(PCa)是否存在相关性.方法 分别采用聚合酶链反应-限制性片段长度多态性方法(PCR-RFLP)和序列特异性引物扩增方法(PCR-SSP),检测78例PCa患者和88例前列腺增生(BPH)患者的ecNOS基因G894T和ecNOS 4a/b VNTR多态性,分析两组ecNOS G894T和ecNOS 4a/b VNTR的基因型频率与等位基因频率的差异.结果 ecNOSG894T存在G、T 2种等位基因以及GG、GT、TT 3种基因型,ecNOS4a/b VNTR存在a、b 2种等位基因以及aa、ab及bb 3种基因型.PCa组与BPH组相比,ecNOS G894T和ecNOS4a/b VNTR的基因型频率及等位基因频率差异无统计学意义(P均>0.05).结论 ecNOS基因多态性不是前列腺癌发病的遗传危险因素.     

Gene transfer of endothelial nitric oxide synthase partially restores nitric oxide synthesis and erectile function in streptozotocin diabetic rats

PURPOSE: We determined whether adenoviral gene transfer of endothelial nitric oxide synthase (eNOS) to the penis of streptozotocin induced diabetic rats could improve the impaired erectile response. MATERIALS AND METHODS: Two experimental groups of animals were transfected with adenoviruses, including streptozotocin (Sigma Chemical Company, St. Louis, Missouri) diabetic rats with AdCMVbetagal and streptozotocin diabetic rats with AdCMVeNOS. At 1 to 2 days after transfection these study animals underwent cavernous nerve stimulation to assess erectile function and their responses were compared with those of age matched control rats. In control and transfected streptozotocin diabetic rats eNOS and neuronal NOS (nNOS) were examined by Western blot analysis. Constitutive and inducible NOS activities were evaluated in the presence and absence of calcium by L-arginine to L-citrulline conversion and nitrate plus nitrite levels were measured. In control and streptozotocin diabetic penes beta-galactosidase activity and localization were determined. RESULTS: After transfection with AdCMVbetagal beta-galactosidase was localized to the endothelium and smooth muscle cells of the streptozotocin diabetic rat penis. Streptozotocin diabetic rats had a significant decrease in erectile function, as determined by peak and total intracavernous pressure (area under the curve) after cavernous nerve stimulation compared with control rats. Streptozotocin diabetic rats transfected with AdCMVeNOS had peak intracavernous pressure and area under the curve similar to those in control animals. This change in erectile function was a result of eNOS over expression with an increase in eNOS protein expression and constitutive NOS activity as well as an increase in nitric oxide biosynthesis, as reflected by an increase in cavernous nitrate plus nitrite formation. There was no change in nNOS protein expression or calcium independent conversion of NOS (inducible NOS activity). CONCLUSIONS: Adenoviral gene transfer of eNOS significantly increased peak and total intracavernous pressure to cavernous nerve stimulation in streptozotocin diabetic rats to a value similar to the response observed in control rats. Our results suggest that eNOS contributes significantly to the physiology of penile erection. These data demonstrate that in vivo adenoviral gene transfer of eNOS can physiologically improve erectile function in the streptozotocin diabetic rat.     

Temporal changes in myocardial endothelial nitric oxide synthase expression following human heart transplantation.

BACKGROUND: The incidence of cardiac allograft vasculopathy increases with time after heart transplantation. Allograft vasculopathy is associated with endothelial dysfunction and reduced endothelium-dependent nitric oxide-mediated vascular effects. In this study, temporal changes in endothelial nitric oxide synthase (NOS3) expression in human myocardial biopsies were investigated during the first 3 years after heart transplantation. METHODS: In each patient (n = 7), the immunohistochemical presence of NOS3 and inducible nitric oxide synthase were examined in serial biopsies taken at 1, 4, and 26 weeks and at 1, 2, and 3 years after transplantation. RESULTS: Endothelial nitric oxide synthase was present in vascular endothelial cells in all biopsies at the time of transplantation. A rapid fall within the first months in the number of NOS3-positive biopsies was observed, with a possible difference in the rate of disappearance among the capillaries, the arterial endothelium, and the venous endothelium. After 2 years, very little NOS3 could be detected. Inducible nitric oxide synthase was present in vascular smooth muscle cells throughout the study period and did not change. CONCLUSION: Endothelial nitric oxide synthase immunoreactivity is gradually lost after heart transplantation. These changes may be responsible for the coronary endothelial dysfunction often seen after human cardiac transplantation.     

Risk of advanced diabetic nephropathy in type 1 diabetes is associated with endothelial nitric oxide synthase gene polymorphism

Risk of advanced diabetic nephropathy in type 1 diabetes is associated with endothelial nitric oxide synthase gene polymorphism. BACKGROUND: Polymorphisms in the endothelial nitric oxide synthase gene (eNOS) may be implicated in the development of nephropathy in patients with type 1 or insulin-dependent diabetes mellitus (IDDM). METHODS: Three groups of IDDM patients were selected to study this hypothesis: cases with advanced diabetic nephropathy (N = 78), cases with overt proteinuria but normal serum creatinine (N = 74), and controls with normoalbuminuria despite 15 years of diabetes (N = 195). Parents of 132 cases and 53 controls were also examined and were used for the transmission disequilibrium test, a family-based study design to test association. RESULTS: We examined four eNOS polymorphisms, and two were associated with diabetic nephropathy in the case-control comparisons: a T to C substitution in the promoter at position -786 and the a-deletion/b-insertion in intron 4. For the former, the risk of developing advanced nephropathy was higher for C allele homozygotes than for the other two genotypes (odds ratio 2.8, 95% CI, 1.4 to 5.6). For the latter polymorphism, it was the a-deletion carriers that had the higher risk (odds ratio 2.3, 95% CI, 1.3 to 4.0) in comparison with noncarriers. Both polymorphisms were analyzed together as haplotypes in a family-based study using the transmission disequilibrium test. The C/a-deletion haplotype was transmitted from heterozygous parents to cases with advanced diabetic nephropathy with a significantly higher frequency than expected (P = 0.004). CONCLUSION: The findings of the case-control and family-based studies demonstrate clearly that DNA sequence differences in eNOS influence the risk of advanced nephropathy in type 1 diabetes.     

左旋精氨酸恢复eNOS和iNOS平衡并抑制肺动脉高压的研究

目的 探讨诱导型一氧化氮合酶(iNOS)在中、晚期肺动脉高压(PH)发病中的作用机制及左旋精氨酸 (L-Arg)对其产生的影响.方法 30只雄性SD大鼠随机均分为5组,对照组(C组)、MCT3组(M3组)、MCT5组(M5组)、L-Arg3/MCT3组(L3组)、L-Arg5/MCT5组(L5组).除C组外其他组大鼠均用野百合碱一次性腹腔注射诱导PH模型.此后L3组和L5组分别连续每天腹腔注射L-Arg 3周和5周,M3组和M5组分别连续每天腹腔注射与L-Arg等量的生理盐水3周和5周,C组连续每天腹腔注射与L-Arg等量的生理盐水共5周.实验周期结束则用右心导管法测定右心室收缩压(RVSP),间接反映肺动脉压力,然后取大鼠肺组织做免疫组化,检测各组iNOS、内皮一氧化氮合酶(eNOS)和弹性蛋白(elastin)的表达变化.结果 M3和M5组中iNOS和elastin的表达明显高于C组,而eNOS表达明显少于C组;L3和L5组iNOS和elastin的表达少于相应M3和M5组,但L5组两种蛋白表达仍高于C组,L3和L5组eNOS的减少明显比相应M3和M5组少,但不及C组.结论 PH形成的中、晚期,肺组织中eNOS表达减少,而此时iNOS的表达增高可能产生大量一氧化氮(NO),但并没有改善PH的病情,而L-Arg能够恢复eNOS和iNOS之间的平衡并有效抑制PH的进展.     

Altered endothelial nitric oxide synthase targeting and conformation and caveolin-1 expression in the diabetic kidney

Experimental diabetes is associated with complex changes in renal nitric oxide (NO) bioavailability. We explored the effect of diabetes on renal cortical protein expression of endothelial NO synthase (eNOS) with respect to several determinants of its enzymatic function, such as eNOS expression, membrane localization, phosphorylation, and dimerization, in moderately hyperglycemic streptozotocin-induced diabetic rats compared with nondiabetic control rats and diabetic rats with intensive insulin treatment to achieve near-normal metabolic control. We studied renal cortical expression and localization of caveolin-1 (CAV-1), an endogenous modulator of eNOS function. Despite similar whole-cell eNOS expression in all groups, eNOS monomer and dimer in membrane fractions were reduced in moderately hyperglycemic diabetic rats compared with control rats; the opposite trend was apparent in the cytosol. Stimulatory phosphorylation of eNOS (Ser1177) was also reduced in moderately hyperglycemic diabetic rats. eNOS colocalized and interacted with CAV-1 in endothelial cells throughout the renal vascular tree both in control and moderately hyperglycemic diabetic rats. However, the abundance of membrane-localized CAV-1 was decreased in diabetic kidneys. Intensive insulin treatment reversed the effects of diabetes on each of these parameters. In summary, we observed diabetes-mediated alterations in eNOS and CAV-1 expression that are consistent with the view of decreased bioavailability of renal eNOS-derived NO.     

内皮型一氧化氮合酶在大鼠糖尿病膀胱病变中的作用

目的 探讨大鼠糖尿病膀胱病变组织中内皮型一氧化氮合酶(eNOS)的表达及意义.方法 雄性SD大鼠36只.随机分为正常组、多尿组和糖尿病组,每组12只.采用尿动力学方法对大鼠膀胱容量、单次排尿量、膀胱内最大压力、残尿壁和排尿率等指标进行评价,应用RT-PCR和蛋白质印迹方法检测大鼠膀胱组织中eNOS mRNA和蛋白质的表达水平,统计学分析其与膀胱功能的相关性.结果 6周时正常组大鼠最大膀胱容量、单次排尿量、残余尿量分别为(0.75±0.04)、(0.70±0.02)和(0.06±0.00)ml,多尿组分别为(1.62±0.15)、(1.52±0.30)和(0.11±0.01)ml,糖尿病组分别为(2.29±0.16)、(2.06±0.25)和(0.23±0.01)ml,与正常组和多尿组相比,差异具有统计学意义(P＜0.01);12周时正常组上述指标分别为(0.86±0.06)、(0.80±0.04)和(0.07±0.00)ml,多尿组分别为(1.93±0.10)、(1.77±0.11)和(0.13±0.02)ml,糖尿病组分别为(2.65±0.26)、(2.09±0.21)和(0.56±0.06)ml,各组间差异具有统计学意义(P＜0.01).糖尿病组与6周时相比,各指标增加,其中残余尿量差异具有统计学意义(P＜0.01).6周时3组排尿率分别为(93.3±2.1)%、(93.2±2.7)%和(90.0±2.5)%,组间差异无统计学意义(P＞0.05);12周时分别为(93.1±2.2)%、(93.8±3.2)%和(78.1±2.6)%,糖尿病组小于其他2组(P＜0.05).各组膀胱内压力差异无统计学意义.糖尿病组膀胱压力曲线出现压力小波动,曲线不规则.6周时各组膀胱组织中eNOSmRNA表达相对灰度值分别为0.81±0.12、0.90±0.12和1.98±0.16,糖尿病组高于其他2组,差异具有统计学意义(P＜0.01);12周时为0.87±0.17、1.05±0.11和2.89±0.23,糖尿病组与6周时相比增加(P＜0.01).6周时各组eNOS蛋白表达相对灰度值分别为0.98±0.12、0.93±0.14和2.28±0.16,糖尿病组高于其他2组(P＜0.01);12周时为1.03±0.13、1.14±0.11和3.12±0.20,糖尿病组与6周时相比增加(P＜0.01).糖尿病组大鼠膀胱eNOS蛋白表达强度与排尿率旱负相关(r=-0.669,P＜0.01).结论 膀胱组织中eNOS mRNA和蛋白表达上调可能参与了糖尿病膀胱病变的发生发展.     

Association of endothelial nitric oxide synthase gene polymorphisms with end-stage renal disease: a systematic review and meta-analysis

Background and objective: Endothelial nitric oxide synthase (eNOS) is one of the potent regulators of intra renal hemodynamics. Polymorphisms of eNOS gene may be involved in the progression of renal disease, and may be the causative factors that contribute to the deterioration of renal functions. During the past decades, several studies investigated the association of eNOS polymorphisms with the risk of end-stage renal disease (ESRD), but the results remain unclear and the mechanisms are not defined. Our study was designed to examine the role of different eNOS genetic polymorphisms in the progression of ESRD. Materials and methods: Relevant studies were identified through PubMed, Embase, Medline and CNKI (China National Knowledge Infrastructure) database published between January 2000 and November 2013. The association between eNOS polymorphisms and ESRD susceptibility was assessed by pooled odds ratios (ORs) and 95% confidence intervals (95% CI) in fixed or random effects models. Results: Sixteen articles were identified for the analysis of association between eNOS gene polymorphisms and ESRD risk. A total of 2729 patients and 2190 controls for 4b/a, 851 patients and 1171 controls for G894T, and 513 patients and 487 controls for T786C were included in our analysis. Overall, 4a allele of 4b/a polymorphism produced a significant association in the global population (OR?=?1.47, 95% CI?=?1.05–2.06, p?=?0.03) in a random-effect model; T allele of G894T was also significantly associated with ESRD susceptibility in overall populations (OR?=?2.12, 95% CI?=?1.44–3.12, p?=?0.0001). Furthermore, 4a and T carriers were significantly associated with ESRD risk as well. No association was found between T786C polymorphism and ESRD. Conclusion: The evidence accumulated suggested that 4b/a and G894T polymorphisms in the eNOS gene were associated with ESRD susceptibility, indicating that 4a and T allele carriers might become significant genetic molecular markers for the onset of ESRD in overall populations. However, more studies should be performed in the further studies.     

T-786C polymorphism of the endothelial nitric oxide synthase gene is associated with albuminuria in the diabetes heart study

Albuminuria demonstrates significant heritability in multiply affected hypertensive and diabetic families. The role of endothelial nitric oxide synthase (eNOS) gene variants as risk factors for albuminuria was investigated in 590 European American siblings from 230 families in the Diabetes Heart Study. Two polymorphisms in the eNOS gene (T-786C in the promoter region and Glu298Asp in exon 7) were genotyped. Albuminuria was defined as an albumin:creatinine ratio (ACR) >/=17 mg/g in men and >/=25 mg/g in women. Tests of association were based on generalized estimating equations, and tests of linkage disequilibrium were based on the quantitative pedigree disequilibrium test. A total of 83% of participants had type 2 diabetes. The median ACR was 10.7 mg/g (interquartile range, 5.1 to 32.8), and 34% (202 of 590) of participants had an elevated ACR. The eNOS -786C allele but not the Glu298Asp was associated with increased ACR (31% increase in absolute level of ACR for each additional copy of the -786C allele; P < 0.0001) and a higher risk for albuminuria (odds ratio, 1.55 for each additional copy of the -786C allele; P = 0.0005). Adjustment for the nongenetic determinants of ACR had no significant effect on the results; neither did stratification by gender, presence of diabetes, and the Glu298Asp genotype. Results were confirmed by quantitative pedigree disequilibrium test analysis and were consistent with haplotype analysis. The -786C eNOS variant was positively correlated with a higher prevalence and a greater degree of albuminuria in European American families in both diabetic and nondiabetic family members.     

The correlation between gene polymorphisms of endothelial nitric oxide synthase and aneurismal subarachnoid hemorrhage

Neurosurgical Review - To discuss the association of the T786C and G894T polymorphisms of endothelial nitric oxide synthase (eNOS) with the occurrence and prognosis of aneurismal subarachnoid...