Association of G894T polymorphism in endothelial nitric oxide synthase gene with the risk of ischemic stroke: A meta-analysis

Effects of Nitric Oxide Synthase 3 Gene Polymorphisms on Cardiovascular Events in a General Japanese Population ― The Yamagata (Takahata) Study ―

Background: Single nucleotide polymorphisms (SNPs) in nitric oxide synthase 3 (NOS3) are associated with cardiovascular risk factors. However, it is not clear whether the NOS3 SNP is a genetic risk factor for cardiovascular diseases.

Methods and Results: This prospective cohort study included 2,726 subjects aged ≥40 years who participated in a community-based health checkup. We genotyped 639 SNPs, including 2 NOS3 SNPs (rs1799983 and rs1808593). All subjects were monitored prospectively over a median follow-up period of 16.0 years, with the endpoint being cardiovascular events, including cardiovascular death and/or non-fatal myocardial infarction. Kaplan-Meier analysis demonstrated that both rs1799983 GT/TT and rs1808593 GG carriers had a higher risk of the endpoint than non-carriers. Univariate and multivariate Cox proportional hazard regression analyses revealed that both rs1799983 GT/TT and rs1808593 GG were independently associated with cardiovascular events after adjusting for confounding risk factors. The net reclassification index and integrated discrimination index were significantly improved by the addition of NOS3 SNPs as cardiovascular risk factors.

Conclusions:NOS3 gene polymorphisms could be genetic risk factors for cardiovascular events in the general Japanese population, and could be used to facilitate the early identification of individuals at high risk of cardiovascular events.

Sequence Variation in the DDAH1 Gene Predisposes for Delayed Cerebral Ischemia in Subarachnoidal Hemorrhage

Delayed cerebral ischemia (DCI) often causes poor long-term neurological outcome after subarachnoidal hemorrhage (SAH). Asymmetric dimethylarginine (ADMA) inhibits nitric oxide synthase (NOS) and is associated with DCI after SAH. We studied single nucleotide polymorphisms (SNPs) in the NOS3, DDAH1, DDAH2, PRMT1, and AGXT2 genes that are part of the L-arginine–ADMA–NO pathway, and their association with DCI. We measured L-arginine, ADMA and symmetric dimethylarginine (SDMA) in plasma and cerebrospinal fluid (CSF) of 51 SAH patients at admission; follow-up was until 30 days post-discharge. The primary outcome was the incidence of DCI, defined as new infarctions on cranial computed tomography, which occurred in 18 of 51 patients. Clinical scores did not significantly differ in patients with or without DCI. However, DCI patients had higher plasma ADMA and SDMA levels and higher CSF SDMA levels at admission. DDAH1 SNPs were associated with plasma ADMA, whilst AGXT2 SNPs were associated with plasma SDMA. Carriers of the minor allele of DDAH1 rs233112 had a significantly increased relative risk of DCI (Relative Risk = 2.61 (1.25–5.43), p = 0.002). We conclude that the DDAH1 gene is associated with ADMA concentration and the incidence of DCI in SAH patients, suggesting a pathophysiological link between gene, biomarker, and clinical outcome in patients with SAH.

Influence of interleukin-1 beta gene polymorphisms on the risk of myocardial infarction and ischemic stroke at young age in vivo and in vitro

In this study, by using vivo and vitro model, we assessed whether interleukin (IL)-1beta gene polymorphisms influence on the risk of myocardial infarction and ischemic stroke at young age. 147 patients (age < 45 years) with a first episode of MI and 56 patients (age < 45 years) with first-ever cerebral ischemia consecutively were admitted to this study from the Department of Chinese PLA General Hospital. Meanwhile, 91 normal volunteers without MI or stroke were deeded as control group and greed to give blood samples for DNA analysis and biochemical measurements by written informed consent. IL-1β-511 wild type (WT, CC) and SNP (TT) were established and transfected into Rat myocardial H9c2 cell and Mouse brain endothelial bEND.3 cells. In Young Age MI or stroke patients, the IL-1β levels of patients with 511CC are higher than that of patients with 511TT. In our study, NF-κB miRNA, iNOS activity, NF-κB, iNOS and Bax protein expressions of MI-induced H9c2 cell or stroke-induced bEND.3 cells in IL-1β-511TT group were lower than those of IL-1β-511CC. Additionally, the protein expression of MMP-2 of MI-induced H9c2 cell or stroke-induced bEND.3 cells in IL-1β-511TT group were higher than that of IL-1β 511CC group. In conclusion, our data indicate that IL-1β-511TT/CC influence on the risk of myocardial infarction and ischemic stroke at young age through NF-κB, iNOS, MMP-2 and Bax.

Genetic Contributions to the Development of Complications in Preterm Newborns

Aim

We aimed to identify specific polymorphisms of genes encoding for vascular endothelial growth factor A (VEGFA), endothelial nitric oxide synthase (eNOS), renin-angiotensin system (angiotensinogen gene [AGT], angiotensinogen type 1 receptor [AGTR1], angiotensin-converting enzyme [ACE]), and heme oxygenase-1 (HMOX-1) in a cohort of preterm infants and correlate their presence with the development of respiratory distress syndrome (RDS) requiring mechanical ventilation (MV), bronchopulmonary dysplasia (BPD), intraventricular hemorrhage (IVH) and retinopathy of prematurity (ROP).

Study Design

We carried out a retrospective study to evaluate the allele frequency and genotype distribution of polymorphisms of VEGFA, eNOS, AGT, AGTR1, ACE, and HMOX-1 in a population of preterm neonates (n=342) with a gestational age ≤28 weeks according to the presence or absence of RDS requiring MV, BPD, IVH, or ROP. Moreover, we evaluated through the haplotype reconstruction analysis whether combinations of the selected polymorphisms are related to the occurrence of RDS, BPD, IVH and ROP.

Results

In our population 157 infants developed RDS requiring MV, 71 BPD, 70 IVH, and 43 ROP. We found that TC+CC rs2070744 eNOS (41.7 vs. 25.4%, p=0.01) and GT+TT rs1799983 eNOS (51.8 vs. 35.2%, p=0.01) polymorphisms are independent risk factors for BPD. Haplotype reconstruction showed that haplotypes in VEGF and eNOS are significantly associated with different effects on RDS, BPD, IVH, and ROP in our population.

Conclusions

We found that TC+CC rs2070744 eNOS and GT+TT rs1799983 eNOS polymorphisms are independent predictors of an increased risk of developing BPD. Haplotypes of VEGFA and eNOS may be independent protective or risk markers for prematurity complications.