Endothelial nitric oxide synthase tagging single nucleotide polymorphisms and recovery from 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.

Association between Endothelial nitric oxide synthase and Hepatic lipase gene polymorphisms with the risk of coronary artery disease in Southern Iran population - A case control study

Coronary artery disease is a multifactorial genetic disease caused by the interaction between genetic and environmental factors. Angiography is the gold standard method for the diagnosis and determining the stage of cardiac disorder. The rs1800588 at the Hepatic Lipase gene and rs1799983 at the endothelial nitric oxide synthase (eNOS) gene are two candidate SNP that result in increased risk of this disease. The aim of this study was to find out the associations of the two mentioned polymorphisms with angiographically proven coronary artery patients in a southern Iranian population. In this study, this two polymorphisms in 287 patients and 229 matched controls were confirmed by angiography and analyzed. Genotype analysis was carried out by PCR and RFLP. Data showed that a significant difference for the eNOS gene polymorphism (p = 0.004) and a non-significant difference for the Hepatic lipase polymorphism (p = 0.261) and increasing severity of angiographic evidences of coronary artery disease were observed. Conclusively the significant association of the G894T with the narrowing of two or three coronary vessels of this patients in an Iranian population have been detected.

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.

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.

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

To discuss the association of the T786C and G894T polymorphisms of endothelial nitric oxide synthase (eNOS) with the occurrence and prognosis of aneurismal subarachnoid hemorrhage (aSAH). One hundred sixty-nine patients with aSAH were collected as the case group, which was divided into the good prognosis group and adverse prognosis group according to the condition 3 months after the treatment. One hundred fifty-six healthy volunteers were collected as the control group. The allele and genotype of T786C and G894T polymorphisms of eNOS were detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The genotype and allele frequency of eNOS were compared between different groups. And then, the risk factors of aSAH occurrence and prognosis were analyzed by using the logistic regression model. Both the genotype and allele frequency distributions of T786C and G894T between the case group and control group were significantly different (P < 0.05). There were significant differences in the distribution of G894T and T786C allele frequency and G894T genotype between the good prognosis group and adverse prognosis group, and there was no difference in T786C genotype. The results of the logistic regression analysis indicated that T786C and G894T polymorphisms of eNOS were independent influencing factors on the occurrence of aSAH and the G894T polymorphism was also closely related to the prognosis. T786C and G894T polymorphisms of eNOS gene were correlated with the occurrence and prognosis of aSAH, and the G894T polymorphism might be an independent influencing factor.

Genetics and Genomics of Acute Neurologic Disorders

Neurologic diseases and injuries are complex and multifactorial, making risk prediction, targeted treatment modalities, and outcome prognostication difficult and elusive. Genetics and genomics have affected clinical practice in many aspects in medicine, particularly cancer treatment. Advancements in knowledge of genetic and genomic variability in neurologic disease and injury are growing rapidly. Although these data are not yet ready for use in clinical practice, research continues to progress and elucidate information that eventually will provide answers to complex neurologic questions and serve as a platform to provide individualized care plans aimed at improving outcomes. This article provides a focused review of relevant literature on genetics, genomics, and common complex neurologic disease and injury likely to be seen in the acute care setting.

Biological Markers in Nursing Research

INTRODUCTION

Biobehavioral research requires the ability to objectively measure the presence and/or severity of disease, symptoms and their burden, or to determine the effect of treatment on outcomes. Biomarker research has advanced care for patients across the lifespan. There have been significant advancements in biological marker use for nursing research in recent years. The purposes of this article are to define the characteristics of a valid biomarker; review common biological sources of genetic, hormonal, and proteomic biomarkers with attention to practical strengths, weaknesses, and challenges for specimen selection and quality; and discuss potential use of biomarkers in clinical and research settings.

METHODS

Authors draw on the literature and research experiences to address the issues relevant to incorporating biomarkers into nursing research.

RESULTS AND DISCUSSION

An overview of the practical aspects of incorporating biomarkers into nursing research, and the resultant actual and potential clinical applications, are discussed.

Role of Genetic Polymorphisms in Predicting Delayed Cerebral Ischemia and Radiographic Vasospasm After Aneurysmal Subarachnoid Hemorrhage: A Meta-Analysis

OBJECTIVE

The pathophysiology on cerebral vasospasm and delayed cerebral ischemia (DCI) remains poorly understood. Much research has been dedicated to finding genetic loci associated with vasospasm and ischemia. We present a systematic review and meta-analysis to identify genetic polymorphisms associated with delayed ischemic neurologic deficit (DIND), radiographic infarction attributed to ischemia, and radiographic vasospasm.

METHODS

PubMed, the Cochrane Library, and Excerpta Medica dataBASE (EMBASE) databases were used to identify relevant studies published up to March 2015 containing the subject terms cerebral or intracranial vasospasm and DCI in combination with genetics, gene, polymorphism or marker. Meta-analyses were performed using a random-effects model to calculate summary odds ratio (ORs) and 95% confidence intervals for each respective gene.

RESULTS

Of 269 articles initially identified, 20 studies with 1670 patients were included in our comprehensive review, including 27 polymorphisms in 11 genes. The following 6 polymorphisms in 3 genes were selected for subsequent meta-analyses: apolipoprotein E (ApoE2, E4); endothelial nitric oxide (eNOS T786C, VNTR intron 4 a/b, G894T); and haptoglobin (Hp) 1/2 phenotypes. The eNOS VNTR a allele was associated with DIND (a vs. b allele: OR 1.92 [1.31-2.81], padj = 0.008). The Hp 2-2 allele was associated with radiographic vasospasm (2-2 vs. 2-1 and 1-1: OR 3.86 [1.86-8.03], padj = 0.003) but did not reach significance for DIND.

CONCLUSIONS

This is the first systemic review and meta-analysis to study and evaluate the associations between genetic polymorphism with DCI and radiographic vasospasm independently. In our study, eNOS VNTR and Hp polymorphisms appear to have the strongest associations with DIND and radiographic vasospasm, respectively.

CT perfusion-derived mean transit time of cortical brain has a negative correlation with the plasma level of Nitric Oxide after subarachnoid hemorrhage

BACKGROUND

Vasospasm of both large and small parenchymal arteries may contribute to the occurrence of delayed ischemic neurological deficits, and nitric oxide(NO) is an important mediators in the development of cerebral vasospasm after subarachnoid hemorrhage (SAH). We used a rabbit two-hemorrhage model to investigate changes in plasma NO after SAH, and the relationship between NO and brain microcirculation.

METHODS

SAH was induced in rabbits and a control group was sham operated. There were 32 rabbits in each group that survived the second operation, and they were randomly assigned to four groups of eight rabbits each for follow-up assessments on Days 1, 4, 7, or 14, respectively. Cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) were calculated at six regions of interest (ROIs): symmetrical areas of the frontal, parietal-occipital, and temporal lobes. Before the contrast CT scan, blood was drawn from the central artery of the ear for measurement of plasma NO.

RESULTS

In the control group, there was no difference in CBV, CBF, and MTT in the six ROIs, and plasma NO was unchanged. Compared to controls, in the SAH group, CBV decreased slightly in the six ROIs (P > 0.05), frontal lobe CBF decreased, MTT increased (P < 0.05, for both), and NO plasma levels were significantly lower (P < 0.01).

CONCLUSIONS

There was a significant correlation between the increase in MTT and the decrease in plasma NO (P < 0.05), We hypothesized that normalization of NO might have a positive influence on brain microcirculation following SAH.

Haptoglobin genotype and functional outcome after aneurysmal subarachnoid hemorrhage

OBJECT

Haptoglobin allele heterogeneity has been implicated in differential reactive oxidant inhibition and inflammation. Haptoglobin α2-α2 has a lower affinity for binding hemoglobin, and when bound to hemoglobin, is cleared less easily by the body. The authors hypothesized that haptoglobin α2-α2 genotype should be less protective for downstream injury after aneurysmal subarachnoid hemorrhage (aSAH) and should portend a worse outcome.

METHODS

Patients with Fisher Grade 2 or higher aSAH were enrolled in the study. Genotyping for haptoglobin genotype was performed from blood and/or CSF. Demographic information, medical condition variables, and hospital course were abstracted from the medical record upon enrollment into the study. Outcome data (modified Rankin Scale score, Glasgow Outcome Scale score, and mortality) were collected at 3 months posthemorrhage.

RESULTS

The authors enrolled 193 patients who ranged in age from 18 to 75 years. Only Caucasians were used in this analysis to minimize bias from variable haptoglobin allele frequencies in populations of different ancestral backgrounds. The sample had more women than men (overall mean age 54.45 years). Haptoglobin α2 homozygotes were older than the other individuals in the study sample (57.27 vs 53.2 years, respectively; p = 0.02) and were more likely to have Fisher Grade 3 SAH (p = 0.02). Haptoglobin α2-α2 genotype, along with Fisher grade and Hunt and Hess grade, was associated with a worse 3-month outcome compared to those with the haptoglobin α1-α1 genotype according to modified Rankin Scale score after controlling for covariates (OR 4.138, p = 0.0463).

CONCLUSIONS

Patients with aSAH who carry the haptoglobin α2-α2 genotype had a worse outcome. Interestingly, the presence of a single α-2 allele was associated with worse outcome, suggesting that the haptoglobin α-2 protein may play a role in the pathology of brain injury following aSAH, although the mechanism for this finding requires further research. The haptoglobin genotype may provide additional information on individual risk of secondary injury and recovery to guide care focused on improving outcomes.

A tailed primers protocol to identify the association of eNOS gene variable number of tandem repeats polymorphism with ischemic stroke in Chinese Han population by capillary electrophoresis

Endothelial nitric oxide synthase (eNOS) plays an important role in mediating endothelium-dependent vasodilatation and antithrombotic action and is thus involved in the development of ischemic stroke (IS). Controversial results regarding the association of eNOS gene variable number of tandem repeats (VNTR) polymorphism with IS have been reported by conventional PCR-polyacrylamide gel electrophoresis methods. We aimed to identify any common association of eNOS gene VNTR polymorphism with IS in Chinese Han population by capillary electrophoresis (CE). The VNTR polymorphism of 27 bp within the eNOS intron-4 was determined by CE with specially designed tailed primers in Chinese Han patients with IS (n=457) and matched elderly controls without IS (n=457). Significant differences in BMI, WHR, hypertension, diabetes, smoking, TG, HDL, LDL, LDL, and FBG were observed between cases and controls. The distributions of eNOS VNTR polymorphism were not significantly associated with IS after adjustment for cardiovascular risk factors (OR=1.18, 95% CI: 0.82-1.69). This finding was consistent with the further meta-analysis in Asians. The meta-analysis in Americans demonstrated that 4a/4b+4a/4a genotype was significantly associated with IS risk with an OR of 1.54 (95% CI, 1.09-2.17) compared with the 4b/4b genotype. Our data suggests that BMI, WHR, hypertension, diabetes, smoking, TG, LDL, and FBG may increase the risk of IS. However, eNOS VNTR polymorphism may be not an independent major contributor for IS in Chinese Han population. The VNTR polymorphism might be associated with IS in Americans based on meta-analysis.

The importance of early brain injury after subarachnoid hemorrhage

Aneurysmal subarachnoid hemorrhage (aSAH) is a medical emergency that accounts for 5% of all stroke cases. Individuals affected are typically in the prime of their lives (mean age 50 years). Approximately 12% of patients die before receiving medical attention, 33% within 48 h and 50% within 30 days of aSAH. Of the survivors 50% suffer from permanent disability with an estimated lifetime cost more than double that of an ischemic stroke. Traditionally, spasm that develops in large cerebral arteries 3-7 days after aneurysm rupture is considered the most important determinant of brain injury and outcome after aSAH. However, recent studies show that prevention of delayed vasospasm does not improve outcome in aSAH patients. This finding has finally brought in focus the influence of early brain injury on outcome of aSAH. A substantial amount of evidence indicates that brain injury begins at the aneurysm rupture, evolves with time and plays an important role in patients' outcome. In this manuscript we review early brain injury after aSAH. Due to the early nature, most of the information on this injury comes from animals and few only from autopsy of patients who died within days after aSAH. Consequently, we began with a review of animal models of early brain injury, next we review the mechanisms of brain injury according to the sequence of their temporal appearance and finally we discuss the failure of clinical translation of therapies successful in animal models of aSAH.

Fibrinogen polymorphisms associated with sporadic cerebral hemorrhage in a Chinese population

Fibrinogen plays an important role in the intrinsic and extrinsic pathways of blood coagulation. This study investigated the association between common variants in the fibrinogen gene and the risk of developing sporadic cerebral hemorrhage (CH). We performed genotyping analyses for three single nucleotide polymorphisms (SNP) in the fibrinogen gene in a case-controlled study involving 195 patients with CH and 116 control participants; both groups were of southern Han-Chinese origin. Logistic regression analysis indicated that haplotypes ATA (rs1800790+rs1800787+rs6050), AA (rs1800790+rs6050) and TA (rs1800787+rs6050) could nearly double the risk of sporadic CH (odds ratio [OR]=1.738, 95% confidence interval [CI]: 1.103-2.740, p=0.017; adjusted OR=1.762, 95% CI: 1.042-2.982, p=0.035), although the three SNP were not associated with sporadic CH when analyzed separately. These findings indicate that rs1800790, rs1800787 and rs6050 polymorphisms may contribute to the etiology of sporadic CH in the Chinese population.

Genomic, transcriptomic, and epigenomic approaches to recovery after acquired brain injury

Genomics and its related fields have expanded rapidly, primarily because of the potential utility for clinical decision making and improving our understanding of the pathophysiology of complex conditions. The state of the science and technology associated with this field is such that current and future health care providers, when consulting with new patients about their acquired brain injury and options for rehabilitation, will use genetic information as a routine part of the process, which may include information received from a laboratory report that uses transcriptomic data, informs regarding patient prognosis, and makes recommendations for individualized therapeutic approaches to optimize recovery. This may sound like science fiction, but, in the field of oncology, it is the norm for breast cancer and, more recently, for colon cancer, with expansion to other types of cancer on the horizon as research data continue to contribute to the understanding of the pathophysiology of these conditions. Something similar for rehabilitation after acquired brain injury is much further off on the horizon. However, it is a possibility that will never be realized if the community of scientists and health care providers who work with these patients do not have the knowledge or expertise to embrace genomics and related approaches. This article discusses these approaches, some practical considerations for using such approaches, and what is currently published in this area with regard to brain injury.