Epistasis analysis for estrogen metabolic and signaling pathway genes on young ischemic stroke patients

SULT genetic polymorphisms: physiological, pharmacological and clinical implications

INTRODUCTION

Cytosolic sulfotransferases (SULTs)-mediated sulfation is critically involved in the metabolism of key endogenous compounds, such as catecholamines and thyroid/steroid hormones, as well as a variety of drugs and other xenobiotics. Studies performed in the past three decades have yielded a good understanding about the enzymology of the SULTs and their structural biology, phylogenetic relationships, tissue/organ-specific/developmental expression, as well as the regulation of the SULT gene expression. An emerging area is related to the functional impact of the SULT genetic polymorphisms.

AREAS COVERED

The current review aims to summarize our current knowledge about the above-mentioned aspects of the SULT research. An emphasis is on the information concerning the effects of the polymorphisms of the SULT genes on the functional activity of the SULT allozymes and the associated physiological, pharmacological, and clinical implications.

EXPERT OPINION

Elucidation of how SULT SNPs may influence the drug-sulfating activity of SULT allozymes will help understand the differential drug metabolism and eventually aid in formulating personalized drug regimens. Moreover, the information concerning the differential sulfating activities of SULT allozymes toward endogenous compounds may allow for the development of strategies for mitigating anomalies in the metabolism of these endogenous compounds in individuals with certain SULT genotypes.

Combined Effects of MMP-7, MMP-8 and MMP-26 on the Risk of Ischemic Stroke

Ischemic stroke (IS) is multifactorial causation combining with traditional cardiovascular disease (CVD) and genetic risk factors. Combined effects of MMP-7, MMP-8 and MMP-26 on the risk of IS remain incompletely understood. We aimed to assess individual and joint effects for IS risk by weighted genetic risk score (wGRS) from these three genes and traditional CVD risk factors. A case-control study including 500 cases with IS and 500 stroke-free healthy controls frequency-matched with cases by age and sex was conducted. The wGRS was a weighted average of the number of risk genotype across selected SNPs from MMP-7, MMP-8 and MMP-26. Multivariate logistic regression models were used to analyze the relationship between wGRS and risk of IS. A wGRS in the second tertile was associated with a 1.5-fold increased risk of IS compared with the lowest tertile after adjusting for traditional CVD risk factors. Compared to subjects with low genetic and low modifiable CVD risk, those with high genetic and high modifiable CVD risk had the highest risk of IS (adjusted-OR = 5.75). In conclusion, higher wGRS was significantly associated with an increased risk for IS. A significant interaction between genetic and traditional CVD risk factors was also found on the risk of IS.

Association of Catechol-O-methyltransferase (COMT Val158Met) with future risk of cardiovascular disease in depressed individuals - a Swedish population-based cohort study

Background

Catechol-O-methyltransferase (COMT Val¹⁵⁸Met) has been implicated in both depression and cardiovascular disease. The purpose of this study was to assess if COMT Val¹⁵⁸Met, which influences the COMT enzyme activity, has an effect on the risk of cardiovascular disease (CVD) in individuals with a history of depression and also to determine if the risk differs depending on gender.

Methods

Data from a longitudinal cohort study of mental health among Swedish adults was used. Depression was assessed twice 3 years apart for each participant, in 1998–2001 and 2001–2003. Saliva DNA was contributed by 4349 (41.7%) of the participants and 3525 was successfully genotyped for COMT Val¹⁵⁸Met. Participants were followed up until December 2014 from the National Patient register with regard to cardiovascular outcomes (hypertensive or ischemic heart disease, and stroke).

Results

Those with depression and the high COMT enzyme activity genotype (Val/Val) had almost a three-fold increased risk of later CVD (OR 3.6; 95% CI: 2.0-6.6) compared to those non-depressed carrying the Val/Val allele. This effect on risk for CVD was higher in women compared to men (OR 7.0; 95% CI: 3.0-14.0 versus OR 2.1; 95% CI: 1.0-6.8). Both additive interaction (attributable proportion (AP) = 0.56; 95% CI: 0.24-0.90 and synergy index (SI) = 4.39; 1.0-18.7) and multiplicative interaction (log likelihood test p = 0.1) was present between depression and COMT Val¹⁵⁸Met in predicting risk of later CVD.

Conclusion

High COMT activity genotype Val¹⁵⁸Met increased the risk of CVD in depressed persons. The risk was higher in women compared to men.

Capturing pair-wise epistatic effects associated with three agronomic traits in barley

Genetic association mapping has been widely applied to determine genetic markers favorably associated with a trait of interest and provide information for marker-assisted selection. Many association mapping studies commonly focus on main effects due to intolerable computing intensity. This study aims to select several sets of DNA markers with potential epistasis to maximize genetic variations of some key agronomic traits in barley. By doing so, we integrated a MDR (multifactor dimensionality reduction) method with a forward variable selection approach. This integrated approach was used to determine single nucleotide polymorphism pairs with epistasis effects associated with three agronomic traits: heading date, plant height, and grain yield in barley from the barley Coordinated Agricultural Project. Our results showed that four, seven, and five SNP pairs accounted for 51.06, 45.66 and 40.42% for heading date, plant height, and grain yield, respectively with epistasis being considered, while corresponding contributions to these three traits were 45.32, 31.39, 31.31%, respectively without epistasis being included. The results suggested that epistasis model was more effective than non-epistasis model in this study and can be more preferred for other applications.

Association of miR-146a, miR-149, miR-196a2, miR-499 gene polymorphisms with ischemic stroke in a Chinese people

This study aimed to investigate genetic polymorphisms of miR-146a, miR-149, miR-196a2, and miR-499 and genetic susceptibility of ischemic stroke in the population of Guangxi in China. A case–control study was used to investigate miRNAs genetic polymorphisms in 298 patients with ischemic stroke and 303 healthy controls. Single-base extension polymerase chain reaction genotyping principle was used to detect genetic polymorphisms of miRNAs,and the relationship of genotype in each group and blood lipid was compared and analyzed. The genetic polymorphism of miR-499A>G (rs3746444) was associated with ischemic stroke (P < 0.05), and the risk of ischemic stroke was high in patients with G allele (OR = 1.455; 95% CI = 0.531–2.381; P = 0.039) and AG (OR = 1.339; 95% CI = 1.126–1.967; P = 0.037) genotype. The levels of low-density lipoprotein cholesterol, very-low-density lipoprotein cholesterol, homocysteine, and lipoprotein in the ischemic stroke group were higher than those in the control group (P < 0.05). The genetic polymorphism of miR-499A>G (rs3746444) was related to ischemic stroke, and G allele and AG genotype may increase the risk of ischemic stroke in the population of Guangxi in China.

Tumor necrosis factor beta NcoI polymorphism (rs909253) is associated with inflammatory and metabolic markers in acute ischemic stroke

Polymorphisms in genes coding for pro-inflammatory molecules represent important factors for the pathogenesis and outcome of stroke. The aim of this study was to evaluate the relationship between the tumor necrosis factor beta (TNF-β) NcoI (rs909253) polymorphism with inflammatory and metabolic markers in acute ischemic stroke. Ninety-three patients and 134 controls were included. The TNF-β polymorphism was determined using PCR-RFLP with NcoI restriction enzyme. Stroke subtypes and neurological deficit score were evaluated. White blood cell counts, erythrocyte sedimentation rate (ESR), plasma levels of IL-6 and TNF-α, serum high sensitivity C-reactive Protein (hsCRP), serum lipid profile, plasma levels of glucose and insulin, and homeostatic model assessment of insulin resistance (HOMA-IR) were determined. Stroke patients presented higher white blood cell counts, hsCRP, ESR, glucose, insulin, and HOMA-IR, and lower HDL cholesterol than controls (p < 0.01). There was no difference in genotypic and allelic frequency of TNF-β NcoI polymorphism among patients and controls (p > 0.05). However, stroke patients carrying the TNFB2/B2 genotype presented higher levels of TNF-α, white blood cell counts, total cholesterol, LDL cholesterol, glucose, insulin, and HOMA-IR than those with other genotypes (p < 0.05). White blood cells, IL-6, hsCRP, and ESR were positively correlated with the neurological deficit of the patients (p < 0.05). Taken together, TNF-β NcoI polymorphism, by itself, was not associated with increased susceptibility for stroke development. However, the homozygous genotype for the allele TNFB2 was associated with higher expression of classical inflammatory and metabolic markers of development and outcome of stroke than other genotypes. The identification of variant alleles might allow both better prediction of susceptibility for stroke as well the identification of novel stroke mechanisms that could be target to new therapeutic approaches. Stroke patients carrying the TNFB2 variant allele could have a beneficial effect with the anti-inflammatory therapies in the early inflammatory phase of stroke.

Genetic polymorphisms in the ESR1 gene and cerebral infarction risk: a meta-analysis

A number of studies have documented that estrogen receptor α (ESR1) may play an important role in the development and progression of cerebral infarction, but many existing studies have yielded inconclusive results. This meta-analysis was performed to evaluate the relationships between ESR1 genetic polymorphisms and cerebral infarction risk. The PubMed, CISCOM, CINAHL, Web of Science, Google Scholar, EBSCO, Cochrane Library, and CBM databases were searched for relevant articles published before October 1, 2013, without any language restrictions. Meta-analysis was conducted using the STATA 12.0 software. Seven case-control studies were included with a total of 1471 patients with cerebral infarction and 4688 healthy control subjects. Two common single-nucleotide polymorphisms (SNPs) in the ESR1 gene (rs2234693 T>C and rs9340799 A>G) were assessed. Our meta-analysis results revealed that ESR1 genetic polymorphisms might increase the risk of cerebral infarction. Subgroup analysis by SNP type indicated that both rs2234693 and rs9340799 polymorphisms in the ESR1 gene were strongly associated with an increased risk of cerebral infarction. Further subgroup analysis by ethnicity showed significant associations between ESR1 genetic polymorphisms and increased risk of cerebral infarction among both Asians and Caucasians. In the stratified subgroup analysis by gender, the results suggested that ESR1 genetic polymorphisms were associated with an increased risk of cerebral infarction in the female population. However, there were no statistically significant associations between ESR1 genetic polymorphisms and cerebral infarction risk in the male population. Meta-regression analyses also confirmed that gender might be a main source of heterogeneity. Our findings indicate that ESR1 genetic polymorphisms may contribute to the development of cerebral infarction, especially in the female population.