The influence of the endothelin-converting enzyme-1 gene polymorphism on the progression of autosomal dominant polycystic kidney disease

Endothelin-1 gene polymorphism (G8002A) and endothelial monocyte-activating polypeptide II: Role in vascular dysfunction in pediatric patients with β-thalassemia major

BACKGROUND

Endothelin-1 (ET-1), a potent endogenous vasoconstrictor, stimulates production of reactive oxygen species. Endothelial monocyte-activating polypeptide-II (EMAP-II) is a multifunctional polypeptide.

AIM

To assess ET-1 gene polymorphism (G8002A) in pediatric patients with β-thalassemia major (β-TM) as a potential genetic marker for vascular dysfunction and its possible relation to EMAP II, oxidative stress and vascular complications.

METHODS

β-TM patients (n = 95) without symptomatic cardiac or renal disease were compared with 95 healthy controls. Markers of hemolysis, serum ferritin, urinary albumin-to-creatinine ratio, serum EMAP II, malondialdehyde (MDA) and antioxidant enzymes; superoxide dismutase (SOD), glutathione peroxidase (GPx), reduced glutathione (GSH), glutathione reductase and catalase were measured. ET-1 gene polymorphism (G8002A) was determined using polymerase chain reaction‑restriction fragment length polymorphism.

RESULTS

β-TM patients had significantly higher EMAP II than healthy controls. EMAP II was significantly higher among patients with cardiac disease, pulmonary hypertension (PH) risk, nephropathy, poor compliance to therapy and ferritin ≥ 2500 μg/L. There were significant correlations between EMAP II and transfusion index, LDH, ferritin and oxidative stress markers. The AA genotype of ET-1 gene polymorphism (G8002A) was significantly higher among β-TM patients than controls. The number of patients with cardiac disease, PH risk or nephropathy was significantly higher among AA genotype compared with GG and GA genotypes. Lactate dehydrogenase (LDH), serum ferritin, EMAP II, MDA, SOD and GPx were significantly higher in AA genotype.

CONCLUSION

ET-1 gene polymorphism (G8002A) could be a possible genetic marker for prediction of increased susceptibility to cardiopulmonary and renal complications among pediatric patients with β-TM.

Endothelin-1 RS5370 gene polymorphism in primary nephrotic syndrome: A case-control study

INTRODUCTION

Primary nephrotic syndrome (NS) is a common glomerular disease in children. We assessed the genotypes and frequency of the rs5370 allelic variant of the EDN1 gene in children with primary NS.

PATIENTS AND METHODS

We conducted a case-control study in Mansoura University Children's Hospital, Egypt between December 2015 and January 2018. We recruited 50 patients with steroid-sensitive NS (SSNS) and 50 patients with steroid-resistant NS (SRNS) in addition to 100 healthy controls. The patients underwent clinical evaluations and tests including measurement of serum albumin, cholesterol, creatinine and urea levels and a 24-h urinary protein test. We used polymerase chain reaction methods to assess the genotypes of rs5370 variants of the EDN1 gene (GG, GT and TT) and alleles (T and G) in the groups under study.

RESULTS

The most frequent genotype of the EDN1 gene at the locus of interest in the control group was the GT genotype (88%; P=.001) while the GG genotype was more frequent in the NS group compared to the control group (P=.02). We did not find statistically significant differences between the NS and control groups in regard to the EDN1 rs5370 alleles (P=.69). The GG genotype was more frequent in the SSNS group compared to the SRNS and control groups (P=.03). When we compared allele frequencies between the control, SSNS and SRNS groups, we did not find significant differences (P=.89). The GT genotype was associated with normal blood pressure in children with NS (P=.007), while the GG genotype was associated with hypertension (P<.001). We did not find statistically significant differences in renal histopathology or serum cholesterol levels based on the genotype.

CONCLUSIONS

The GG genotype at the rs5370 locus of the EDN1 gene may be associated with an increased risk of primary NS and a better response to steroid therapy.

[Endothelin-1 rs5370 gene polymorphism in primary nephrotic syndrome: A case-control study]

INTRODUCTION

Primary nephrotic syndrome (NS) is a common glomerular disease in children. We assessed the genotypes and frequency of the rs5370 allelic variant of the EDN1 gene in children with primary NS.

PATIENTS AND METHODS

We conducted a case-control study in Mansoura University Children's Hospital, Egypt, between December 2015 and January 2018. We recruited 50 patients with steroid-sensitive NS (SSNS) and 50 patients with steroid-resistant NS (SRNS) in addition to 100 healthy controls. The patients underwent clinical evaluations and tests including measurement of serum albumin, cholesterol, creatinine and urea levels and a 24-hour urinary protein test. We used polymerase chain reaction methods to assess the genotypes of rs5370 variants of the EDN1 gene (GG, GT and TT) and alleles (T and G) in the groups under study.

RESULTS

The most frequent genotype of the EDN1 gene at the locus of interest in the control group was the GT genotype (88%; P=.001) while the GG genotype was more frequent in the NS group compared to the control group (P=.02). We did not find statistically significant differences between the NS and control groups in regard to the EDN1 rs5370 alleles (P=.69). The GG genotype was more frequent in the SSNS group compared to the SRNS and control groups (P=.03). When we compared allele frequencies between the control, SSNS and SRNS groups, we did not find significant differences (P=.89). The GT genotype was associated with normal blood pressure in children with NS (P=.007), while the GG genotype was associated with hypertension (P<.001). We did not find statistically significant differences in renal histopathology or serum cholesterol levels based on the genotype.

CONCLUSIONS

The GG genotype at the rs5370 locus of the EDN1 gene may be associated with an increased risk of primary NS and a better response to steroid therapy.

Association of Endothelin-1 rs5370 G>T gene polymorphism with the risk of nephrotic syndrome in children

Background:

Primary nephrotic syndrome (NS) is a common kidney disease in children. Objectives: The present study was aimed to investigate whether rs5370 G>T (lys198Asn) genetic variant of endothelin-1 (ET-1) is involved in the susceptibility to NS.

Patients and Methods:

This case-control study was performed on 138 patients with NS and 150 healthy children. Genomic DNA was extracted from whole blood using salting out method. Polymorphism of the ET-1 rs5370 G>T (lys198Asn) polymorphism detected by T-ARMS-PCR as well as PCR-RFLP method.

Results:

The results showed that the genotype and allelic frequencies of the ET-1 rs5370 G>T variant were not significantly different between cases and controls. Furthermore, subgroup analysis showed that rs5370 G>T variant was not associated with gender of patients. In NS patients the genotype was not associated with cholesterol, triglyceride, total protein and albumin levels.

Conclusions:

In conclusion, our findings indicate that ET-1 rs5370 G>T is not associated with NS. Further studies with larger sample sizes and different ethnicities are required to validate our findings.

ET-1 actions in the kidney: evidence for sex differences

Hypertension and chronic kidney disease are more common in men than in premenopausal women at the same age. In animal models, females are relatively protected against genetic or pharmacological procedures that produce high blood pressure and renal injury. Overactivation or dysfunction of the endothelin (ET) system modulates the progression of hypertension or kidney diseases with the ET(A) receptor primarily mediating vasoconstriction, injury and anti-natriuresis, and ET(B) receptors having opposite effects. The purpose of this review is to examine the role of the ET system in the kidney with a focus on the inequality between the sexes associated with the susceptibility to and progression of hypertension and kidney diseases. In most animal models, males have higher renal ET-1 mRNA expression, greater ET(A) -mediated responses, including renal medullary vasoconstriction, and increased renal injury. These differences are reduced following gonadectomy suggesting a role for sex hormones, mainly testosterone. In contrast, females are relatively protected from high blood pressure and kidney damage via increased ET(B) versus ET(A) receptor function. Furthermore, ET(A) receptors may have a favourable effect on sodium excretion and reducing renal damage in females. In human studies, the genetic polymorphisms of the ET system are more associated with hypertension and renal injury in women. However, the knowledge of sex differences in the efficacy or adverse events of ET(A) antagonists in the treatment of hypertension and kidney disease is poorly described. Increased understanding how the ET system acts differently in the kidneys between sexes, especially with regard to receptor subtype function, could lead to better treatments for hypertension and renal disease. LINKED ARTICLES This article is part of a themed section on Endothelin. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2013.168.issue-1.

Association of endothelin-converting enzyme-1b C-338A polymorphism with gastric cancer risk: a case-control study

To investigate the association between endothelin-converting enzyme-1b (ECE-1b) C-338A polymorphism and gastric cancer risk, we conducted a hospital-based case-control study of 256 gastric cancer cases and 256 controls matched on age and gender. The genotypes were identified by polymerase chain reaction-restriction fragment length polymorphism. We found that the genotype frequencies were significantly different (P=0.005) between cases and controls. Compared with the wild genotype CC, the variant genotypes (CA+AA) were associated with a 64% increased risk of gastric cancer [adjusted odds ratio (OR)=1.64, 95% confidence interval (CI) 1.15-2.33]. Further stratification analyses indicated that the increased risk was especially noteworthy in older subjects (age 58) (adjusted OR=1.91, 95% CI 1.18-3.09), women (adjusted OR=2.30, 95% CI 1.11-4.79) and non-smokers (adjusted OR=1.79, 95% CI 1.19-2.67). Our results suggest that the ECE-1b C-338A polymorphism may be associated with increased risk of gastric cancer.

Endothelin-converting enzyme-1b C-338A polymorphism is associated with the increased risk of coronary artery disease in Chinese population

BACKGROUND

Endothelin-converting enzyme-1 (ECE-1), the key enzyme responsible for endothelin-1 generation, has been linked to coronary artery disease (CAD). Recently, a genetic polymorphism (ECE-1b C-338A) located in ECE-1 gene promoter was identified. However, it is unclear whether this polymorphism is associated with the risk of CAD.

METHODS

We conducted a study with CAD patients and controls matched by age and sex to examine the prevalence of ECE-1b C-338A polymorphism in CAD.

RESULTS

The frequencies of ECE-1b-338CC, CA, and AA genotypes in cases (40.1%, 42.2%, and 17.7%) were significantly different from those of controls (50.6%, 40.5%, and 8.9%, chi2=9.989, P=0.007). Subjects with the variant genotypes (CA+ AA) had a 58% increased risk of CAD relative to CC carriers (adjusted OR=1.58, 95% CI=1.07-2.32). Furthermore, the adjusted OR of AA genotype for CAD was 2.33 (95% CI=1.25-4.35). In stratified analyses, the A allele was significantly associated with increased risk of CAD in female (adjusted OR=2.86, 95% CI=1.40-5.84) and subjects with age >or= 64 y (adjusted OR=2.96, 95% CI=1.73-5.08). Moreover, the frequency of patients with variant genotypes increased gradually from single- to triple-vessel disease although without statistical significance (P=0.069 for trend).

CONCLUSION

Our results suggested that ECE-1b-338C to A variant might be associated with increased risk of CAD in Chinese population.