Association of the NOS3 intron-4 VNTR polymorphism with aneurysmal subarachnoid hemorrhage

Patients with Invasive Tumors and eNOS Gene Polymorphisms with Subarachnoid Hemorrhage Tend to Have Poorer Prognosis

Context  Endothelial nitric oxide synthase ( eNOS) gene polymorphisms are found to predict predisposition to aneurysmal rupture and development of vasospasm in a patient of subarachnoid hemorrhage (SAH). eNOS gene polymorphisms are also found to predict invasiveness of malignant cells. Studies are not available in literature to describe the effect of eNOS gene polymorphisms and correlation between aneurysm and carcinoma. This study aims to investigate whether positive cancer history influences clinical outcome following SAH and eNOS gene polymorphisms.

Materials and Methods  The eNOS gene polymorphisms were analyzed in seven consecutive patients (mean age, 52.28 ± 20 years) with a diagnosis of invasive systemic tumors from 2011 to 2017. The eNOS 4a/4b eNOS -786T> eNOS 894G > T polymorphisms of the eNOS gene were determined by polymerase chain reaction and restriction fragment length polymorphism.

Results  Seven patients of aneurysmal SAH in association with malignancies were studied for eNOS polymorphisms expression and outcome. Three patients had carcinoma cervix: one patient of carcinoma breast and one each of transitional cell carcinoma of urinary bladder, spindle cell carcinoma of left kidney, and untreated patient of atypical pituitary (adenoma). A genotype study of eNOS gene polymorphisms in these patients shows common polymorphisms are involved in the determination of disease progression in malignancies and aneurysmal SAH.

Conclusion  Patients who expressed 4ab, eNOS -786T > TT/CC/TC, eNOS 894G > T GG/GT polymorphisms did better than patients who expressed only 4bb, though both were associated with poor prognosis.

Epigenetic response of endothelial cells to different wall shear stress magnitudes: A report of new mechano-miRNAs

Endothelial cells (ECs) respond to flow stress via a variety of mechanisms, leading to various intracellular responses that can modulate the vessel wall and lead to diseases if the flow is disturbed. Mechano-microRNAs (miRNAs) are a subset of miRNAs in the ECs that are flow responsive. Mechano-miRNAs were shown to be related to atherosclerosis pathophysiology, and a number of them were identified as pathologic. Here, we exposed human carotid ECs to different wall shear stresses (WSS), high and low, and evaluated the response of miRNAs by microarray and quantitative polymerase chain reaction analysis. We discovered five new mechano-miRNAs that were not reported in that context previously to the best of our knowledge. Moreover, functional pathway analysis revealed that under low WSS conditions, several pathways regulating apoptosis are affected. In addition, KLF2 and KLF4, known atheroprotective genes, were downregulated under low WSS and upregulated under high WSS. KLF2 and VCAM1, both angiogenic, were upregulated under high WSS. NOS3, which is vascular protective, was also upregulated with higher WSS. On the contrary, ICAM-1 and E-selectin, both atherogenic and proinflammatory, were upregulated with high WSS. Collectively, the epigenetic landscape with the gene expression analysis reveals that low WSS is associated with a proapoptotic state, while high WSS is associated with a proliferative and proinflammatory state.

The Correlation of Endothelial Nitric Oxide Synthase (eNOS) Polymorphism and Other Risk Factors with Aneurysmal Subarachnoid Hemorrhage: A Case-Control Study

Objective

Endothelial nitric oxide synthase gene (eNOS) polymorphism is an association with cerebral aneurysm formation, rupture, and vasospasm and plays a role in the a functional outcome.

Patients and Methods

The aim of the study was to evaluate the role of eNOS gene polymorphism and further assess the predictors of outcome in the aneurysmal subarachnoid hemorrhage (aSAH). A prospective case-control study was conducted from 2009 to 2012 among those who presented with aSAH. A serum sample was collected from aSAH patients along with age and sex-matched healthy controls. The frequency of polymorphism of eNOS gene and other factors (demographic and aneurysmal) were correlated with functional outcome at six month of follow-up.

Results

100 patients with aSAH and 100 healthy controls were enrolled in the cohort. The mean age of the patient group was 51.61 years and control group was 45.81 years with a male:female ratio of 1:1.38 and 1:1.08 for patients and controls, respectively. Among all eNOS polymorphisms, 4BB (65%) 24-VNTR, TT (71%) of T-786C, and GG (71%) of G947T were the most common and frequency was similar in the control group. The occurrences of hypertension, smoking, diabetes were 32%, 37%, and 7% respectively in the patient group. Maximum patients were in WFNS grade 1 (53%) followed by 23% grade 2 and only 10% in grade 4. Fisher grade 3 (57%) was the most common followed by Fisher grade 4 (28%). Most aneurysms (97%) were in anterior circulation. 83% of the aneurysms were clipped and 10% underwent coiling. Size-wise most of the aneurysms were in the middle group (6-9 mm) followed by bigger group (>10 mm) (37%); only 6% aneurysms were in the small aneurysm (<6 mm) group. 33% of the patients had evidence of vasospasm. TT of G894T polymorphism (60%) had the highest incidence of vasospasm. Univariate analysis showed smoking (OR: 3.19, CI: 1.19-8.84, P = 0.01), 4AA (OR: 12.15, CI: 1.13-624.9, P = 0.03) variety of 24-VNTR polymorphism, CC (OR: 15.39, CI: 1.60-762.8, P = 0.01) variety of T786C polymorphism, Fisher grade 4 (OR: 3.43, CI: 1.24-9.68, P = 0.01), WFNS grade (poor vs. good) (OR: 3.42, CI: 1.17-10.12, P = 0.02), vasospasm (OR: 3.84, CI: 1.42-10.75, P = 0.006), intraoperative rupture (OR: 4.77, CI: 1.55-15.27, P = 0.004) were significantly related with unfavorable outcome at 6 months follow-up. In regression analysis, smoking (CI: 0.06-0.69, P = 0.01), Fisher grade 4 (CI: 0.09-1.00, P = 0.05), and intraoperative rupture (CI: 0.05-0.89, P = 0.03) were correlated with an unfavorable outcome at 6 months follow-up.

Conclusion

The eNOS gene polymorphism, smoking, clinical grade (WFNS), Fisher grade, intraoperative rupture, and vasospasm play a role in functional outcome after the treatment of cerebral aneurysms.

Sex differences in risk factors for aneurysmal subarachnoid haemorrhage: Systematic review and meta-analysis

BACKGROUND

Aneurysmal subarachnoid haemorrhage (aSAH) disproportionally affects women. We conducted a systematic review and meta-analysis to explore sex differences in aSAH risk factors.

METHODS

Case-control/cohort studies were searched to November 2017 with sex-specific risk factors for aSAH. Meta-analysis was performed when a risk factor was reported in ≥2 studies.

RESULTS

Of 31 studies, 22 were eligible for meta-analysis. Female sex was associated with greater odds of aSAH (HR_adjusted 1.90 [1.47-2.46]. There was no detectable difference between the sexes for hypertension (OR_adjusted: men 3.13 [2.26-4.34]; women 3.65 [2.87-4.63], p = .18), smoking (OR_adjusted: men 2.96 [1.68-5.21]; women 3.11 [1.21-7.97], p = .95), aSAH family history, systolic blood pressure, age and some genetic variations. Alcohol (OR_adjusted: men 1.50 [1.04-2.17]; women 0.83 [0.48-1.45], p = .003), high alanine aminotransferase levels, and some gene variants increased the risk of aSAH in men. Reproductive factors, divorce and some genetic variations increased the risk in women. High aspartate aminotransferase levels in men and, diabetes (OR_adjusted: men 0.57 [0.32-1.01]; women 0.24 [0.13-0.43], p = .01) and parity in women reduced aSAH risk.

CONCLUSION

We recommend sex-specific re-analysis of existing studies of aSAH risk factors. Known aSAH risk factors (hypertension, smoking and alcohol consumption) should be targeted to prevent aSAH in men and women. Registration PROSPERO (ID: CRD42018091521).

Genetic associations of intracranial aneurysm formation and sub-arachnoid hemorrhage

Risk factors for cerebral aneurysms typically include age, hypertension, smoking, and alcohol usage. However, the possible connection of aneurysms with genetic conditions such as Marfan's syndrome, polycystic kidney disease, and neurofibromatosis raises the question of possible genetic risk factors for aneurysm, and additionally, genetic risk factors for rupture. We conducted a literature review using the PubMed database for studies regarding genetic correlation with cerebral aneurysm formation as well as rupture from December 2008 to Jun 2015. Twenty-one studies related to IA formation and 10 concerning IA rupture that met our criteria were found and tabulated. The most studied gene and the strongest association was 9p21/CDKN2, which is involved in vessel wall remodelling. Other possible genes that may contribute to IA formation include EDNRA and SOX17; however, these factors were not studied as robustly as CDKN2. Multiple factors contribute to aneurysm formation and rupture and the contributions of blood flow dynamics and comorbidities as mentioned previously, cannot be ignored. While these elements are important to development and rupture of aneurysms, genetic influence may predispose certain patients to formation of aneurysms and eventual rupture.

Association between three eNOS polymorphisms and intracranial aneurysms risk: a meta-analysis

Endothelial nitric oxide synthase (eNOS) is the catalyst of endothelial nitric oxide (NO) synthesis. Polymorphisms in the eNOS gene may influence the risk of intracranial aneurysm (IA), but the results of existing researches are still inconsistent. Thus, we performed the present meta-analysis to derive a more precise estimation between eNOS polymorphisms (T786C, G894T, 27-bp-variable number of tandem repeat [VNTR]) and IA risk. Case-control studies evaluating the association between the eNOS polymorphisms and IA risk were searched in PubMed, Ovid & Embase, Web of Science, and Chinese Wanfang datasets with the last search up to July 15, 2014. The pooled odds ratios (ORs) for the association between eNOS polymorphisms and IA and their corresponding 95% confidence intervals (CIs) were estimated using the random or fixed-effects model. Finally, 10 studies for T786C polymorphism (1819 cases and 1893 controls), 9 studies for G894T polymorphism (1393 cases and 1508 controls), and 7 studies for 27-bp-VNTR polymorphism (1281 cases and 1406 controls) were included in the meta-analyses. In the overall analysis, no evidence of association between eNOS polymorphisms and susceptibility of IA was found. When subgrouped by race descent, significantly increased risk was detected among Asians for T786C polymorphism (heterozygous comparison of codominant model: OR = 1.294, 95% CI = 1.025-1.634; dominant model: OR = 1.277, 95% CI = 1.019-1.600), but not in Caucasians or the other 2 polymorphisms. Our meta-analysis suggested that T786C polymorphism was associated with increased risk of IA among Asians, whereas G894T and 27-bp-VNTR polymorphisms might have no influence on the susceptibility of IA.