© 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd

Clin Transplant 2014: 28: 223–228 DOI: 10.1111/ctr.12302

Clinical Transplantation

Endothelial nitric oxide synthase polymorphism influences renal allograft outcome Uyar M, Sezer S, Ozdemir FN, Kulah E, Arat Z, Atac FB, Haberal M. Endothelial nitric oxide synthase polymorphism influences renal allograft outcome. Abstract: Background: Atherosclerotic lesions within the graft are considered to be a major cause of interstitial fibrosis/tubular atrophy (IF/ TA). We evaluated the factors that influence the development of IF/TA and three- and five-yr graft survival including nitric oxide synthase (eNOS) and angiotensin II type 1 and type 2 receptor gene polymorphism. Methods: Seventy-one male and 35 female patients (age: 34.9  11.2 yr) who underwent living-related renal transplantation were included. Angiotensin type 1 and type 2 receptor gene polymorphisms and eNOS intron 4 gene polymorphism were analyzed. The pre- and post-transplant laboratory data, patient characteristics, acute rejection episodes, and presence of IF/TA were evaluated. Results: Patients with the bb allele of eNOS gene had a lower prevalence of post-transplant third year (12.6% and 38.5%, p = 0.005) and fifth year IF/TA (46.6% and 82.3%, p = 0.02) and a lower incidence of five-yr graft failure (35.4% and 55.6%, p < 0.005). The eNOS gene polymorphism was independent and was the most prominent factor associated with third and fifth year IF/TA (p = 0.01, RR: 29.72, and p = 0.03, RR: 4.1, respectively). No significant relationship existed when angiotensin II gene polymorphisms were considered. Conclusions: We concluded that recipient eNOS gene polymorphism can predict IF/TA, and the presence of the bb allele is associated with better graft outcome.

Despite the recent dramatic improvements in graft survival rates, interstitial fibrosis/tubular atrophy (IF/TA) remains a major concern. One of the major manifestations of IF/TA leading to graft loss is accelerated onset of atherosclerotic lesions within the graft. It has been hypothesized that genetic polymorphisms that regulate endothelial responses, which have been implicated in the pathogenesis of native atherosclerosis and hypertension, may also influence kidney graft survival. Response to, or local concentration of, molecules such as nitric oxide (NO) and angiotensin II mediates the effect of polymorphisms on graft survival. NO plays an important role in endothelial function, where its production is catalyzed by endothelial nitric oxide synthase (eNOS). NO seems to inhibit the early stages of atherosclerosis by down-regulating the expression of adhesion molecules and chemokines that promote monocyte–endothelial cell interaction (1). Varying

Murathan Uyara, Siren Sezera, Fatma Nurhan Ozdemira, Eyup Kulaha, Zubeyde Arata, Fatma Belgin Atacb and Mehmet Haberalc a

Department of Nephrology, Baskent University Faculty of Medicine, bDepartment of Molecular Biology, Baskent University Faculty of Medicine and cDepartment of General Surgery, Baskent University Faculty of Medicine, Ankara, Turkey

Key words: interstitial fibrosis/tubular atrophy – eNos gene polymorphism – renal transplantation Corresponding author: Murathan Uyar, MD, Department of Nephrology, Baskent University Faculty of Medicine, 28. Sokak, 4/3, Bahcelievler, 06490, Ankara, Turkey. Tel.: +90 312 212 68 68; fax: +90 312 213 00 34; e-mail: [email protected] Conflict of interest: None. Accepted for publication 21 November 2013

levels of NO have been shown in patients with hypertension, with or without coronary artery disease, and normal subjects with eNOS intron 4a polymorphism (2, 3). Thus, genetic variations in the eNOS gene may influence hypertension and atherosclerotic disease (3, 4), ultimately leading to IF/TA in renal transplantation patients. The eNOS intron 4 polymorphism has been found to be associated with different eNOS mRNA levels and enzyme activities (5, 6). Two alleles of the intron 4 of the eNOS gene have been identified, a and b. In some studies, the a allele of the eNOS gene is associated with coronary artery disease risk, atherosclerosis, and hypertension in patients with type 2 diabetes mellitus and those undergoing hemodialysis with or without coronary artery disease (7–9). Other studies have failed to show this association (10–12). Angiotensin II (AII), as the end product of the renin-angiotensin system (RAS), is also involved in

223

Uyar et al.

proinflammatory cytokine production, vascular smooth muscle cell proliferation, vascular endothelial dysfunction, and apoptosis—all of which are important mechanisms in the formation and progression of atherosclerosis (13). Given the important regulatory effects of NO and AII on endothelial function and the association of atherogenesis with graft loss, we evaluated the association of nitric oxide synthase (eNOS) and the AII type 1 and type 2 receptor gene polymorphisms with the development of IF/TA and three- and five-yr graft survival. Materials and methods

This study was conducted according to the guidelines of the Declaration of Helsinki and was approved by Baskent University Research Ethics Committee. Seventy-one male and 35 female patients (aged 34.9  11.2 yr) who underwent living-related renal transplantation between 1997 and 1999 at our institution with a mean post-transplant follow-up time of 63.8  29.1 months (range, 34–64 months) and a functioning graft for longer than six months were included. All recipients had been followed for a minimum of three yr post-transplantation. The primary causes of chronic renal failure are listed in Table 1. The exclusion criteria included graft loss within six months post-transplantation, recurrence of denovo disease, non-compliance with medical therapy, presence of chronic inflammatory disease, advanced liver disease, and/or malignancy. Angiotensin type 1 and type 2 receptor gene polymorphisms and eNOS intron 4 gene polymorphism of the patients were analyzed. Patients were grouped according to the presence of the most frequently seen allele, and the other alleles for each genotype and were compared to find any influence of genetic polymorphisms on post-transplant clinical and laboratory data. Age at transplantation, donor characteristics, mismatch number, ischemia time, blood pressure, antihypertensive drug use, immunosuppression

Table 1. Etiologies of renal failure Primary disease

(%)

Unknown Glomerulonephritis Alport syndrome Vesicoureteral reflux Hypertension Amyloidosis Nephrolithiasis

33 32.1 8.5 3.8 13.2 2.8 6.6

224

received, acute rejection (AR) episodes, development of post-transplant diabetes mellitus that can influence IF/TA, and graft failure were evaluated. Additionally, the pre- and post-transplant-determined laboratory values of hemoglobin, creatinine, C-reactive protein (CRP), albumin, fibrinogen, lipid profile, intact parathyroid hormone (iPTH), and proteinuria were retrospectively recorded, and the mean values for each year were calculated for each patient. According to our protocol, patients’ hemoglobin and creatinine levels were determined twice weekly in the first three months, every 15 d in the fourth month, monthly up to the 12th month, and every three months up to the fifth year after transplantation. Serum CRP and albumin levels were detected monthly up to the 6th month, every two months for 6–12 months, and every three months after the first year of transplantation. Patients’ fibrinogen, lipid profile, iPTH, and proteinuria levels were determined every three months in the first two yr after transplantation. These parameters were measured every six months after the second year of transplantation. Venous blood samples were drawn after a 12-h overnight fast. Hemoglobin, creatinine, albumin, fibrinogen, and lipid profile, as well as aminotransferases and proteinuria were measured by standard methods at Baskent University Hospital. Serum CRP levels were measured using the turbidimetric latex agglutination method (Biosystems SA, Barcelona, Spain); the upper normal limit was set by the laboratory at 10 mg/L. iPTH levels were determined by DSL-8000 ACTIVE Intact PTH IRMA Kit (Diagnostic Systems Laboratories Inc, Webster, TX, USA). All patients had received a triple drug regimen of prednisone, azathioprine (AZA), and cyclosporine (CsA) for maintenance immunosuppression. The treatment was started 48 h before transplantation. The initial immunosuppressive therapy regimen consisted of CsA, AZA, and prednisolone. Cyclosporine was initiated at 8–10 mg/kg/d p.o. in two divided doses and then adjusted to maintain whole-blood trough levels between 100 and 200 ng/mL using a modular ISE 900 machine with homogenous enzyme immunoassay system (CEDIA Cyclosporine Assay, Roche Diagnostic Corp, Indianapolis, IN, USA). Prednisolone was initiated at 1–2 mg/kg/d p.o. and then tapered over six months to a maintenance dosage of 10 mg/d. AR episodes were suspected on clinical grounds and were always confirmed by kidney biopsy. These episodes were treated with methylprednisolone pulses (10 mg/kg/d for three d). Steroid-resistant cases were treated with OKT3 monoclonal antibody. Chronic rejection was diagnosed if the

eNOS polymorphism in renal transplant patient met at least one of the following criteria: progressive deterioration of renal allograft function or histologically documented features of chronic rejection (14). Renal biopsy was not performed in those patients who had normal and stable renal functions according to the laboratory results from the time of transplantation until now. These patients were considered practically IF/TA absent (14). Determination of the eNOS and AII receptor gene polymorphisms

Genotyping of a and b alleles of eNOS intron 4 VNTR, and the type 1 (1166A?C) (rs5186) and type 2 (3123C?A) (rs11091046) AII receptor gene polymorphisms was performed. Genomic DNA was prepared from leukocyte pellets by sodium dodecyl sulfate lysis, ammonium acetate extraction, and ethanol precipitation. The DNA was used as a template for gene polymorphism analysis. All amplifications were performed using polymerase chain reaction (PCR) sequence-specific primers and appropriate restriction enzymes as described previously (15, 16). The angiotensin type I (ATR1, II [ATR2] and eNOS genotyping primers, and PCR cycling conditions are given in Table 2. Briefly, for the analysis of the ATR1 A1166C polymorphism, a 410-bp PCR product was digested with DdeI enzyme. The 1166A allele lacks the DdeI site. However, the 1166C variant has two bands corresponding with both 292 bp and 118 bp (17). A 321-bp PCR product was cut with AluI for the ATR2 C3123A polymorphism. The uncut product (321 bp) shows the presence of the C allele. If the PCR product was cut into two fragments of 217 bp and 107 bp, it revealed the A allele. The PCR products of the b and a alleles for eNOS intron 4 VNTR genotyping were identified by the presence of 420-bp and 393-bp bands on 2% agarose gel electrophoresis, respectively (18).

Statistical analysis

All calculations were performed with SPSS software (Statistical Package for the Social Sciences, Version 10.0, SPSS Inc, Chicago, IL, USA). Categorical variables were analyzed using chi-square or Fisher’s exact probability test, as appropriate. Differences between groups were tested with the Student’s t-test or Mann–Whitney U-test. Variables that may have an influence on IF/TA were first tested with univariate analyses and subsequently tested with multivariate analyses to construct a stepwise procedure. Values are expressed as mean  SD, and a value for p < 0.05 was considered statistically significant. Results

Patient characteristics and gene polymorphism distributions are shown in Tables 3 and 4. The most frequently seen genotypes were the bb allele (74.5%) for the eNOS gene and the AA allele (59%) and the CC allele (70.7%) for the ATR1 and ATR2 genes, respectively. Patients were grouped as those with the bb allele (n = 79) and those with the aa + ab allele (n = 27) for the eNOS intron 4 gene polymorphism, those with the AA allele and the A/C + C/C alleles for ATR1, and those with the C/C allele and the A/C + A/A alleles for ATR2 gene polymorphisms. When univariate analysis was performed to identify predictors of IF/TA, patients with the bb allele had a lower prevalence of post-transplant third year (12.6% and 38.4%, p = 0.005) and fifth year IF/TA (46.6% and 82.3%, p = 0.02), and a lower incidence of graft failure at year 5 (35.4% and 55.6%, p < 0.005) when the patients who were followed up more than five yr are considered (n = 47) (Table 5). Graft function was not associated with ATR1 and ATR2 gene polymorphisms (p > 0.05). Additionally, patients with the bb allele exhibited lower post-transplant diastolic blood

Table 2. Primers of RAS and eNOS genotyping and PCR cycling conditions Genetic variant ATR1 A1166C Sense Anti-sense ATR2 C3123A Sense Anti-sense eNOS intron 4a/b Sense Anti-sense

PCR cycling conditions

5′AGAAGCCTGCACCATGTTTTGAG3′ 5′CCTGTTGCTCCTCTAACGATTTA3′

309 (94°C 60 s, 57°C 30 s, 72°C 30 s)

5′GGATTCAGATTTCTCTTTGAA3′ 5′GCATAGGAGTATGATTTAATC3′

309 (94°C 45 s, 53°C 60 s, 72°C 60 s)

5′AGGCCCTATGGTAGTGCCTTT3′ 5′TCTCTTAGTGCTGTGGTCAC3′

309 (94°C 60 s, 58°C 60 s, 72°C 60 s)

eNOS, endothelial nitric oxide synthase; PCR, polymerase chain reaction; RAS, renin-angiotensin system.

225

Uyar et al. Table 3. Patient characteristics Mean (SD; for continuous variables) or counts (for categorical variables)

Table 5. Comparison of the b/b and a variant of the eNOS gene in terms of pre-transplantation and mean of post-transplantation three yr eNOS (n = 106)

Age (yr) Age at transplantation (yr) Sex (male/female) Pre-transplant dialysis duration (months) Transplantation duration (months) Presence of acute rejection (%) Third year IF/TA (%) Fifth year IF/TA (%) Post-transplant diabetes mellitus (+/ ) Systolic blood pressure (mm Hg) Diastolic blood pressure (mm Hg)

34.9  11.2 29.5  10.3

b/b

71/35 19.2  22.3 63.8  59.1 41.3 18.8 35 8/106 128.1  19.4 81.5  8.9

IF/TA, interstitial fibrosis/tubular atrophy.

Table 4. Distribution of gene polymorphism Polymorphism

Genotype

(%)

eNOS

a/a a/b b/b AA AC CC AA AC CC

2.8 22.7 74.5 59 36 5 8.1 21.2 70.7

ATR1

ATR2

eNOS, endothelial nitric oxide synthase.

pressure (p = 0.04) and CRP levels (p = 0.02). The relationship between development of CAD and mean levels of serum albumin, serum aminotransferases, parathyroid hormone, hematocrit, total cholesterol, and triglyceride measured at pre-transplant and at yearly intervals throughout follow-up did not reach statistical significance (p > 0.05). When patients were grouped according to ATR1 and ATR2 gene polymorphism distribution, there was no significant relationship among the parameters. When multiple logistic regression analysis was performed, the eNOS gene polymorphism was independent and was the single most prominent factor associated with third and fifth year IF/TA (p = 0.01, RR: 29.72, and p = 0.03, RR: 4.1, respectively).

226

Age at transplantation (yr) Pre-transplant CRP (mg/dL) Pre-transplant PTH (pg/mL) Creatinine (mg/dL) Proteinuria (mg/d) CRP (mg/dL) iPTH (mg/dL) Cholesterol (mg/dL) Systolic blood pressure (mm Hg) Diastolic blood pressure (mm Hg) Antihypertensive (%) Third year IF/TA (%) Fifth year IF/TA (%) (47 patient) Graft loss (%)

a variant

p-Value

30.5  10.5

26.5  9.5

0.04

14.6  14.7

15.3  15.7

>0.05

235.3  189

>0.05

3.7  3.6

6.4  3.8

0.04

1074.5  1420.3

1023.6  1046.3

>0.05

6.0  5.4 194.4  264.7 196.4  47.7

15.8  11.7 535.0  317.1 202  38.8

0.001 >0.05 >0.05

129.9  15.4

122.6  27.9

>0.05

78.8  8.3

82.5  9.07

0.04

225.7  239.7

>0.05

88.1

96.2

12.6 46.6

38.4 82.3

0.005 0.02

3.7

22.2

0.08

CRP, C-reactive protein; eNOS,endothelial nitric oxide synthase; IF/TA, interstitial fibrosis/tubular atrophy; iPTH, intact parathyroid hormone.

Discussion

Chronic allograft nephropathy is still a major concern leading to decreased graft survival. Much effort has been spent in preventing the development of IF/TA and increasing graft survival. An interesting and testable hypothesis for the clinical heterogeneity and differential responsiveness in allograft recipients is genetic variation. Polymorphisms located in genes contributing to endothelial function may be excellent candidates for differential clinical phenotypes. Various investigations have demonstrated that the protective effects and plasma levels of NO are lower with the eNOS non-b (aa + ab) allele compared with the eNOS bb genotype (19). Based on the hypothesis that lower NO levels in the presence of the non-bb allele are associated with accelerated atherosclerosis, and hence poorer renal allograft outcome, we searched for an association between our findings and renal allograft outcome.

eNOS polymorphism in renal transplant In the present study, analysis of the patients with IF/TA (excluding alloantigen-dependent variables) revealed that the presence of the bb allele of eNOS intron 4 gene may be considered protective against IF/TA, whereas the non-b allele may not. It is possible that increased production of NO leads to suppression of inflammation and control of blood pressure. We found that the bb allele was associated with lower CRP levels and lower blood pressure, which can be explained by the production of higher levels of NO by the bb genotype. This elevated level of NO may prevent vascular damage, leading to less IF/TA and longer graft survival rates. Additionally, microvascular effects of NO may play a role in the preservation of graft function. Different factors have been shown to affect endothelial response of eNOS expression. Local factors such as shear stress and transforming growth factor-b have been shown to increase eNOS expression, whereas tumor necrosis factora, which is an inflammatory mediator, causes a decrease in expression of the eNOS gene (20). Regulation and expression of the eNOS gene may be altered as a response to local factors in the presence of different polymorphisms of the eNOS gene. Therefore, it is highly probable that these macro- and microvascular effects of NO are favored in the presence of the bb genotype. Interestingly, the effect of NO on graft function may also be explained by the increased NO levels caused by immunosuppressive agents. Besides its immunosuppressive effects, CsA has been shown to increase eNOS expression in vitro, and this increase may exert an additional protective effect on graft function by causing increased NO levels (21). Further in vivo studies are needed to examine these effects on eNOS gene expression and graft function. There are a limited number of studies concerning the effect of gene polymorphisms on transplantation and IF/TA. In these studies, the eNOS G894T and T-786C gene polymorphisms did not influence long-term renal allograft outcome (22, 23). This lack of association may be partly explained by the different transcription levels of eNOS in different ethnic groups. Previous studies have suggested that genetic variations in the eNOS gene, particularly Glu298Asp, are associated with the development of atherosclerotic diseases, including CAD, myocardial infarction, and hypertension (4, 5, 7, 8). Several different eNOS gene polymorphisms such as T-786C, VBTR intron 4, Glu298Asp, and G894T have been studied with regard to

development of hypertension, CAD, cardiovascular events, insulin resistance, and renal or cardiac transplant outcome. These studies have produced conflicting results. Tanus-Santos et al. studied the distribution of genetic variants of the eNOS gene polymorphism (T-786C, VNTR intron 4, and Glu298Asp) in whites, African Americans, and Asians (24). Marked interethnic differences have been found in the distribution of eNOS variants, haplotype distribution, and association between variants (24, 25). In the present study, in addition to the eNOS gene polymorphism, no significant effect on IF/TA was found when AII receptor gene polymorphisms were considered. It is possible that genetic variants of the AII receptor gene may not cause functional changes that contribute to the pathogenesis of IF/ TA. While there is strong functional evidence for the effect of AII on native atherosclerosis, AII probably plays a less pivotal role in IF/TA, and thus, variations in its receptor transcription are of less importance. The present study may not be entirely exhaustive for the AII receptor gene polymorphisms; further confirmation by other investigations is needed. An important factor is the younger age of our patients and relative absence of comorbid illnesses compared with other studies. Therefore, it may be difficult to extrapolate our findings to all renal transplantation populations. This fact is because of the relatively young age of dialysis patients in Turkey. The data presented here may remain unique to identifying the influence of genetic polymorphisms and renal allograft outcome in such patient populations. In conclusion, the eNOS intron 4 gene bb variant has a major protective effect on IF/TA and may influence graft survival. Our results may help identify those transplant recipients at a high risk of developing IF/TA, and graft loss may decrease with close follow-up of this patient group. Furthermore, because ACE inhibition has been shown to increase NO levels in vitro, prophylactic and therapeutic approaches with ACE or ATR1 inhibitors may prove beneficial in these patients. Authors’ contributions

Murathan Uyar: Concept, data interpretation, drafting the article; Siren Sezer: Concept, critical € review; Fatma Nurhan Ozdemir: Critical review and approval of the article; Eyup Kulah: Data collection; Zubeyde Arat: Statistical analysis; Fatma Belgin Atacß: PCR and laboratory testing; Mehmet Haberal: Approval of the article.

227

Uyar et al. References 1. TSAO PS, LEWIS N, ALPERT S, COOKE JP. Exposure to shear stress alters endothelial adhesiveness. Role of nitric oxide. Circulation 1995: 92: 3513. 2. TSUKADA T, YOKOYAMA K, ARAI T et al. Evidence of association of the ecNOS gene polymorphism with plasma NO metabolite levels in humans. Biochem Biophys Res Commun 1998: 245: 190. 3. FORTUNO A, OLIVAN S, BELOQUI O et al. Association of increased phagocytic NADPH oxidase-dependent superoxide production with diminished nitric oxide generation in essential hypertension. J Hypertens 2004: 22: 2169. 4. LEMBO G, DE LUCA N, BATTAGLI C et al. A common variant of endothelial nitric oxide synthase (Glu298Asp) is an independent risk factor for carotid atherosclerosis. Stroke 2001: 32: 735. 5. RODRIGUEZ-ESPARRAGON FJ, RODRIGUEZ-PEREZ JC, MACIAS-REYES A, ALAMO-SANTANA F. Peroxisome proliferator-activated receptor-gamma2-Pro12Ala and endothelial nitric oxide synthase-4a/b gene polymorphisms are associated with essential hypertension. J Hypertens 2003: 21: 1649. 6. WANG XL, SIM AS, WANG MX, MURRELL GA, TRUDINGER B, WANG J. Genotype dependent and cigarette specific effects on endothelial nitric oxide synthase gene expression and enzyme activity. FEBS Lett 2000: 471: 45. 7. PULKKINEN A, VIITANEN L, KAREINEN A, LEHTO S, VAUHKONEN I, LAAKSO M. Intron 4 polymorphism of the endothelial nitric oxide synthase gene is associated with elevated blood pressure in type 2 diabetic patients with coronary heart disease. J Mol Med 2000: 78: 372. 8. ASAKIMORI Y, YORIOKA N, TANAKA J, KOHNO N. Effect of polymorphism of the endothelial nitric oxide synthase and apolipoprotein E genes on carotid atherosclerosis in hemodialysis patients. Am J Kidney Dis 2003: 41: 822. 9. WANG XL, SIM AS, BADENHOP RF, MCCREDIE RM, WILCKEN DE. A smoking-dependent risk of coronary artery disease associated with a polymorphism of the endothelial nitric oxide synthase gene. Nat Med 1996: 2: 41. 10. GOUNI-BERTHOLD I, GIANNAKIDOU E, MULLER-WIELAND D et al. Peroxisome proliferator-activated receptor-gamma2 Pro12Ala and endothelial nitric oxide synthase-4a/b gene polymorphisms are not associated with hypertension in diabetes mellitus type 2. J Hypertens 2005: 23: 301. 11. MATYAR S, ATTILA G, ACARTURK E, AKPINAR O, INAL T. eNOS gene intron 4 a/b VNTR polymorphism is a risk factor for coronary artery disease in Southern Turkey. Clin Chim Acta 2005: 354: 153. 12. KUNNAS TA, ILVESKOSKI E, NISKAKANGAS T et al. Association of the endothelial nitric oxide synthase gene polymor-

228

13. 14.

15.

16.

17.

18.

19.

20.

21.

22.

23.

24.

25.

phism with risk of coronary artery disease and myocardial infarction in middle-aged men. J Mol Med 2002: 80: 605. WEISS D, SORESCO D, TAYLOR WR. Angiotensin II and atherosclerosis. Am J Cardiol 2001: 87: 25C. KREIS HA, PONTICELLI C. Causes of late renal allograft loss: chronic allograft dysfunction, death, and other factors. Transplantation 2001: 71: S5. LOVATI E, RICHARD A, FREY BM, FREY FJ, FERRARI P. Genetic polymorphisms of the renin-angiotensin-aldosterone system in end-stage renal disease. Kidney Int 2001: 60: 46. MARSDEN PA, HENG HH, SCHERER SW et al. Structure and chromosomal localization of the human constitutive endothelial nitric oxide synthase gene. J Biol Chem 1993: 268: 17478. ABDI R, HUONG TTB, ZEE R, BRENNER BM, MILFORD EL. Angiotensin gene polymorphism as a determinant of posttransplantation renal dysfunction and hypertension. Transplantation 2001: 72: 726. THOMAS S, BRUCE C, BIRKHEAD A, WANG L. Effect of ecNOS polymorphisms and coronary artery disease upon exhaled nitric oxide. J Mol Med 2002: 80: 181. WANG XL, MAHANEY MC, SIM AS et al. Genetic contribution of the endothelial constitutive nitric oxide synthase gene to plasma nitric oxide levels. Arterioscler Thromb Vasc Biol 1997: 17: 3147. TAI SC, ROBB GB, MARSTEN PA. Endothelial nitric oxide synthase: A new paradigm for gene regulation in the injured blood vessel. Arterioscler Thromb Vasc Biol 2004: 24: 405. NAVARRO-ANTOLIN J, REY-CAMPOS J, LAMAS S. Transcriptional induction of endothelial nitric oxide gene by cyclosporine A. A role for activator protein-1. J Biol Chem 2000: 275: 3075. SHENKER NS, HALDAR NA, REILLY JJ, BUNCE M, WELSH KI, MARSHALL SE. The impact of endothelial nitric oxide synthase polymorphisms on long-term renal allograft outcome. Transpl Int 2003: 16: 391. VIKLICKY O, HUBACEK JA, VITKO S et al. G-protein beta-3subunit and eNOS gene polymorphism in transplant recipients with long-term renal graft function. Kidney Blood Press Res 2002: 25: 245. TANUS-SANTOS JE, DESAI M, FLOCKHART DA. Effects of ethnicity on the distribution of clinically relevant endothelial nitric oxide variants. Pharmacogenetics 2001: 11: 719. CASAS JP, BAUTISTA LE, HUMPHRIES SE, HINGORANI AD. Endothelial nitric oxide synthase genotype and ischemic heart disease: meta-analysis of 26 studies involving 23028 subjects. Circulation 2004: 109: 1359.

Endothelial nitric oxide synthase polymorphism influences renal allograft outcome.

Atherosclerotic lesions within the graft are considered to be a major cause of interstitial fibrosis/tubular atrophy (IF/TA). We evaluated the factors...
99KB Sizes 0 Downloads 0 Views