Association of the single-nucleotide polymorphism and haplotype of the P-selectin gene with ischemic stroke

Inflammatory biomarkers of ischemic stroke

Ischemic stroke remains the second leading cause of death and among the major causes of morbidity worldwide. Therapeutic options are currently limited to early reperfusion strategies, while pharmacological neuroprotective strategies despite showing promising results in the experimental setting constantly failed to enter the clinical arena. Inflammation plays an important role in the pathophysiology of ischemic stroke and mediators of inflammation have been longtime investigated as possible prognostic marker and therapeutic target for stroke patients. Here, we summarized available evidence on the role of cytokines, soluble adhesion molecules and adipokines in the pathophysiology, prognosis and therapy of ischemic stroke.

Development and validation of a rapid method for genotyping three P-selectin gene polymorphisms based on high resolution melting analysis

BACKGROUND

High resolution melting (HRM) analysis is one of the newer, reliable, and sensitive genotyping techniques, which offers considerable time and cost savings. P-selectin is an adhesion molecule that has a role in the initial phases of leukocyte adhesion to stimulated platelets and endothelial cells in inflammation. Multiple polymorphisms in P-selectin gene (SELP) that affect the protein sequence have been described. The aim of this study was to design, optimize, and validate a simple and rapid in-house HRM-based method for genotyping the NM_003005.3:c.992G>A (c.992G>A), NM_003005.3:c.1918G>T (c.1918G>T), and NM_003005.3:c.2266A>C (c.2266A>C) SELP polymorphisms.

METHODS

Initial genotyping of three SELP polymorphisms was performed by applying polymerase chain reaction (PCR) with sequence-specific primers (SSP), which was used as a reference method for determination of analytical sensitivity. PCR-HRM was performed with primers for c.2266A>C reported in the literature. Primers for the remaining two polymorphisms were designed using Primer-BLAST. Precision testing was performed using three samples with different genotypes. For accuracy, analytical sensitivity and specificity testing, 20 wild type, 10 heterozygous, and 10 homozygous samples were chosen per polymorphism. Results were expressed as percentage of concordance with the acceptability criterion ≥95%.

RESULTS

Agreement of results was 100% for all validation parameters except for analytical sensitivity for c.1918G>T and c.2266A>C, with agreement of 90%. Repeated analysis using both methods revealed an error in initial genotyping and correct genotyping by PCR-HRM, which was confirmed by Sanger sequencing.

CONCLUSION

The validation confirmed PCR-HRM as a precise, accurate, and specific method for genotyping the c.992G>A, c.1918G>T, and c.2266A>C SELP polymorphisms.

Biomarkers for arterial and venous thrombotic disorders

The haemostatic system maintains the blood in a fluid state, but allows rapid clot formation at sites of vascular injury to prevent excessive bleeding. Unbalances within the haemostatic system can lead to thrombosis. Inspite of successful research our understanding of the disease pathogenesis is still incomplete. There is great hope that genetic, genomic, and epigenetic discoveries will enhance the diagnostic capability, and improve the treatment options. During the preceding 20 years, the identification of polymorphisms and the elucidation of their role in arterial and venous thromboses became an important area of research. Today, a large body of data is available regarding associations of single nucleotide polymorphisms (SNPs) in candidate genes with plasma concentrations and e. g. the risk of ischaemic stroke or myocardial infarction. However, the results for individual polymorphisms and genes are often controversial. It is now well established that besides acquired also hereditary risk factors influence the occurrence of thrombotic events, and environmental factors may add to this risk. Currently available statistical methods are only able to identify combined risk genotypes if very large patient collectives (>10,000 cases) are tested, and appropriate algorithms to evaluate the data have yet to be developed. Further research is needed to understand the functional effects of genetic variants in genes of blood coagulation proteins that are critical to the pathogenesis of arterial and venous thrombotic disorders. In this review genetic variants in selected genes of the haemostatic system and their relevance for arterial and venous thrombosis will be discussed.

Association of PS gene polymorphism and soluble P-selectin levels in atrial fibrillation thromboembolism population in Xinjiang

To investigate the association between the polymorphism of P choose element (p. selectin, PS) and soluble P-selectin levels in atrial fibrillation (AF) thromboembolism in Han and Uigur population of Xinjiang.

METHOD

Using ELISA method determination of plasma level of sPs. The frequency distributions of SNP sP-selectin gene promoter (-2123C/G) and SNP in exon region (Thr715Pro) were investigated by polymerase chain reaction (PCR)-restriction fragment length polymorphism and direct DNA sequence analysis among 302 Xinjiang Uigur and 340 age- and sex-matched Han people.

RESULTS

Cases sPs exist significant difference serum level and the control group. The frequencies of the -2123C/G allele among the Uigur population had no significant differences from those of the Han population. Thr715Pro did not show any polymorphism in the two populations.

CONCLUSIONS

The sP-selectin gene polymorphisms are associated with serum sP-selectin levels or thromboembolic events, suggesting that the patients with nonvalvular AF and thromboembolic events may have genetic susceptibility.

The association of L-selectin polymorphisms with L-selectin serum levels and risk of ischemic stroke

L-selectin is a member of the selectin family of cell adhesion molecules which are important in the transient attachment of leukocytes to endothelial cells, which plays a role in inflammation processes and is one of the earliest events in the pathogenesis of atherosclerosis. No studies have examined the association of this polymorphism with ischemic stroke. Therefore, we investigated that L-selectin gene polymorphism and its soluble level are associated with ischemic stroke in Chinese population. We analyzed single nucleotide polymorphisms of L-selectin gene Pro213Ser (P213S) in 265 patients with ischemic stroke and 280 age and sex matched controls, using PCR-RFLP and DNA sequencing method, while soluble L-selectin levels were measured by ELISA. There were significant differences in the genotype and allele frequencies of L-selectin gene P213S polymorphism between the group of patients with ischemic stroke and the control group (P < 0.05). Soluble L-selectin levels were increased in patients with ischemic stroke compared with controls (P < 0.01). Moreover, The P213S polymorphism of L-selectin was significantly associated with sL-selectin levels, the serum levels of L-selectin PP genotype carriers was significantly higher than no carriers in patients with ischemic stroke (P < 0.05). The P213S polymorphism of L-selectin and its sL-selectin levels are associated with ischemic stroke in Chinese population. Our data suggests that L-selectin gene may play a role in the development of ischemic stroke.

Association of apolipoprotein M gene polymorphisms with ischemic stroke in a Han Chinese population

The apolipoprotein M (ApoM) gene is critical in the formation of pre-β-high-density lipoprotein (HDL) and cholesterol efflux to HDL. In this case and control study, 314 ischemic stroke patients and 389 healthy controls were analyzed for three ApoM gene single-nucleotide polymorphisms (SNPs), i.e., C-1065A, T-855C, and T-778C, using a SNaPshot Multiplex sequencing assay. The genotype and allele frequencies of the T-855C were similar in both ischemic stroke patients and the controls. But the frequency of the TC genotype, the C allele of T-778C, and the A allele of the C-1065A SNPs in ischemic stroke patients was significantly higher than that of the healthy controls. After adjusting for confounding risk factors (such as hypertension, diabetes, tobacco smoking, and alcohol consumption), the ApoM gene TC genotype, C allele of T-778C, and A allele of C-1065A were associated with a risk of ischemic stroke. Moreover, plasma levels of total cholesterol were significantly higher in patients with CC or CT genotypes of T-778C than those with TT genotype in the controls. The current data demonstrated that ApoM T-778 C and C-1065A SNPs were associated with increased risk of ischemic stroke in this Han Chinese population.