Soluble P-selectin levels, P-selectin polymorphisms and cardiovascular disease

Association of the rs3917647 polymorphism of the SELP gene with malnutrition in gastric cancer

BACKGROUND

Malnutrition and cachexia are common syndromes in patients with gastric cancer (GC) and are associated with poor quality of life and poor disease prognosis. However, there is still a lack of molecular factors that can predict malnutrition or cachexia in cancer. Studies have shown that among the potential contributors to the development of cancer cachexia, the level of the inflammatory response to P-selectin is regulated by single nucleotide polymorphisms (SNPs) located in the promoter region of the SELP gene. The aim of this study was to evaluate the association between the single nucleotide polymorphism (SNP)-2028 A/G of the SELP gene and malnutrition in patients receiving chemotherapy for gastric cancer (GC).

METHODS

The study group consisted of 220 GC patients treated with chemotherapy at Jinhua Municipal Central Hospital. DNA was extracted from peripheral leukocytes of whole blood samples using an animal DNA extraction kit. DNA was amplified using a 1.1 × T3 Super PCR mix, and loci corresponding to the peaks were genotyped using SNP1 software.

RESULTS

Patients carrying the A allele had a reduced risk of developing malnutrition compared to patients with the GG genotype (P < 0.001; OR = 3.411; 95% CI = 1.785-6.516). In addition, multivariate analysis indicated that the AA genotype significantly (more than 16-fold) reduced the risk of developing malnutrition (P < 0.001; OR = 0.062; 95% CI = 0.015-0.255).

CONCLUSION

SELP -2028A/G SNP may be a useful marker for assessing the risk of malnutrition in GC patients.

Panax Notoginseng Saponins Combined with Dual Antiplatelet Drugs Potentiates Anti-Thrombotic Effect with Alleviated Gastric Injury in A Carotid Artery Thrombosis Rat Model

OBJECTIVE

To observe the combination effects of Panax notoginseng saponins (PNS)and dual antiplatelet drugs (DAPT), and to explore the mechanism via cyclooxygenase /prostaglandin pathway.

METHODS

Right carotid artery thrombosis was induced in Wistar rats by infiltration with 70% FeCl₃, and the animals were randomly divided into sham group, model group, DAPT group and PNS + DAPT group, intragastrically treated for 4 weeks. The cerebral pia mater microcirculation was observed in vivo after anesthetizing by anatomical microscope. The wet weight of carotid artery thrombosis was measured. Gastric mucosal injury was observed by hematoxylin and eosin staining. Platelet aggregation rate was detected with adenosine diphosphate -induced turbidimetry. Platelet CD62p expression was detected by flow cytometry. Concentrations of 6-Ketoprostaglandin F1 alpha, prostaglandin E₂ in gastric mucosa and thromboxane B₂, 6-Ketoprostaglandin F1 alpha, tissue plasminogen activator, plasminogen activator inhibitor, and fibrin fragment D in the plasma were measured by radioimmunoassay.

RESULTS

PNS and DAPT increased the blood flow volume of cerebral pia mater and decreased erythrocyte aggregation and leukocyte adhesion of model rats. Compared to DAPT, PNS and DAPT further reduced the weight of carotid artery thrombosis with enhanced inhibition of platelet aggregation, increased tissue plasminogen activator levels and decreased fibrin fragment D levels. PNS and DAPT alleviated gastric injury induced by dual antiplatelet drugs and upregulated the expression of 6-Ketoprostaglandin F1 alpha in the gastric mucosa compared with DAPT.

CONCLUSIONS

PNS combined with DAPT increased anti-thrombosis effects of DAPT and mitigated DAPT-related gastric injury. The underlying mechanisms may be associated with enhanced antiplatelet aggregation and activation of the fibrinolytic system and up-regulation of 6-Ketoprostaglandin F1 alpha expression in gastric mucosa.

Quantile-Specific Heritability of Inflammatory and Oxidative Stress Biomarkers Linked to Cardiovascular Disease

PURPOSE

Heritability (h2 , the proportion of the phenotypic variance attributable to additive genetic effects) is traditionally assumed to be constant throughout the distribution of the phenotype. However, the heritabilities of circulating C-reactive protein, interleukin-6, plasminogen activator inhibitor type-1 (PAI-1), and monocyte chemoattractant protein-1 (MCP-1) concentrations depend upon whether the phenotype is high or low relative to their distributions (quantile-dependent expressivity), which may account for apparent gene-environment interactions. Whether the heritabilities of other inflammatory biomarkers linked to cardiovascular disease are quantile-dependent remain to be determined.

PATIENTS AND METHODS

Quantile-specific offspring-parent (βOP) and full-sib regression slopes (βFS) were estimated by applying quantile regression to the age- and sex-adjusted phenotypes of families surveyed as part of the Framingham Heart Study. Quantile-specific heritabilities were calculated as: h2 =2βOP/(1+rspouse) and h2 ={(1+8rspouseβFS)0.5-1}/(2rspouse).

RESULTS

Heritability (h2 ± SE) of lipoprotein-associated phospholipase A2 (Lp-PLA2) mass concentrations increased from 0.11 ± 0.03 at the 10th percentile, 0.08 ± 0.03 at the 25th, 0.12 ± 0.03 at the 50th, 0.20 ± 0.04 at the 75th, and 0.26 ± 0.06 at the 90th percentile, or 0.0023 ± 0.0006 per each one-percent increase in the phenotype distribution (Plinear trend= 0.0004). Similarly, h2 increased 0.0029 ± 0.0011 (Plinear trend= 0.01) for sP-selectin, 0.0032 ± 0.0009 (Plinear trend= 0.0001) for soluble intercellular adhesion molecule 1 (sICAM-1), and 0.0026 ± 0.0006 for tumor necrosis factor receptor 2 (TNFR2) (Plinear trend= 5.0 × 10-6) per each one-percent increase in their distributions when estimated from βOP. Osteoprotegerin and soluble ST2 heritability also increased significantly with increasing percentiles of their distributions when estimated from βFS. Lp-PLA2 activity, CD40 ligand, TNFα, interleukin-18, and myeloperoxidase heritability showed no significant quantile-dependence.

CONCLUSION

The heritabilities of circulating Lp-PLA2-mass, sP-selectin, sICAM-1, TNFR2, osteoprotegerin and soluble ST2 concentrations are quantile-dependent, which may contribute to purported genetic modulations of: 1) sP-selectin's relationships to venous thrombosis, pulmonary hypertension, type 2 diabetes and atorvastatin treatment; 2) sICAM-I's relationships to brain abscess and atorvastatin treatment; and 3) Lp-PLA2's relationships to myocardial infarction and preeclampsia.

Putative functional non-coding polymorphisms in SELP significantly modulate sP-selectin levels, arterial stiffness and type 2 diabetes mellitus susceptibility

BACKGROUND

P-selectin, encoded by SELP, has been implicated as an important molecule in the development of arterial stiffness, consequently leading to vascular complications in T2DM. SELP polymorphisms and increased levels of soluble P-selectin (sP-selectin) have been shown to be associated with several inflammatory diseases. The present work was designed to assess nine putative functional non-coding SELP variants in relation to sP-selectin levels and arterial stiffness in T2DM.

METHODS

The genetic distribution of rs3917655, rs3917657, rs3917739, rs2235302, rs3917843 was determined by restriction fragment length polymorphism-polymerase chain reaction (RFLP-PCR). Genotyping of rs3917779 was performed by tetra primer amplification-refractory mutation system (ARMS)- PCR. Three SNPs i.e. rs3917853, rs3917854, rs3917855 were genotyped by Sanger sequencing. Construction of haplotypes was performed using PHASE software. The data thus obtained was analyzed by appropriate statistical tools.

RESULTS

Two non-coding variants i.e. rs3917657 and rs3917854 of SELP were found to be associated with 2 and 1.7 -fold risk of disease development respectively. However, one non-coding variant rs2235302 was found to provide protection against disease development. Furthermore, variant allele of rs3917854 in T2DM patients was found to be associated with 2.07-fold very high vascular risk. Non-coding haplotype GCAGGCCGC was conferring 4.14-fold risk of disease development. Furthermore, overall sP-selectin levels were higher in T2DM patients when segregated according to genotypes as well as haplotypes. Significant genotype- phenotype correlation was observed for rs3917655 as well as rs3917739 variant in patients and for rs3917854 in controls. In vascular risk categories, a significant genotype- phenotype correlation was observed for rs3917655 and rs2235302. Furthermore, patients with CCGGGCCGC haplotype in high risk category were observed with higher levels of sP-selectin as compared to other haplotypes (p < 0.05).

CONCLUSIONS

Non-coding SELP variants may significantly modulate sP-selectin levels, vascular risk and T2DM susceptibility.

Correlation between P-selectin rs1800807 and rs1800808 Gene polymorphisms and plasma soluble P-selectin concentrations in patients with atrial fibrillation complicated with thromboembolism in Xinjiang, China

This study is to investigate the relationship of P-selectin (Ps) gene rs1800807 and rs1800808 polymorphisms with plasma soluble P-selectin (sPs) in Han, Uygur, and Kazakh people with atrial fibrillation (AF) and thromboembolism (TE) in Xinjiang, China.A total of 778 Han patients (including 131 patients with AF and TE, 229 patients with AF and 418 healthy individuals), 660 Uygur patients (including 118 patients with AF and TE, 232 patients with AF and 310 healthy individuals), and 505 Kazakh patients (including 42 patients with AF and TE, 156 patients with AF and 307 healthy individuals) were enrolled in this study. Polymerase chain reaction-restriction fragment length polymorphism and direct DNA sequence analysis were used to analyze the polymorphisms of rs1800807 and rs1800808 of Ps gene. ELISA was used to determine the plasma sPs level. The association between plasma sPs levels and Ps gene polymorphisms was further analyzed.The sPs concentrations of GG genotype at rs1800807 locus in the Han, Uygur and Kazakh ethnic groups in Xinjiang, China were significantly higher than those of the CC genotype and CG genotype (P < .05). In the rs1800808 locus, plasma sPs concentrations of the heterozygous mutant CT genotypes in Han and Uygur populations were significantly higher than those in the CC and TT genotypes, whereas the plasma sPs concentrations in Kazakh TT genotypes were significantly higher than those in the CC and CT genotypes (P < .05). Among different ethnic groups, there were significant differences in sPs levels of rs1800807 and rs1800808 genotypes (P < .05).Plasma sPs concentrations are associated with Ps genotypes and sPs concentration of the same genotype shows racial differences.

Association of SELP Polymorphisms with Soluble P-Selectin Levels and Vascular Risk in Patients with Type 2 Diabetes Mellitus: A Case-Control Study

P-selectin, an adhesion molecule, is encoded by SELP and known as biomarker of endothelial as well as platelet dysfunction. SELP polymorphisms (rs6136, rs6127, and rs6125) and raised levels of soluble P-selectin (sP-selectin) have been associated with several disease conditions. The present study was aimed to determine the association of SELP variants and sP-selectin levels as well as vascular risk in Type 2 diabetes mellitus (T2DM) patients. The frequency of rs6136, rs6127, and rs6125 was assessed by restriction fragment length polymorphism-polymerase chain reaction (RFLP-PCR). sP-selectin levels were measured using commercially available kits. Haplotypes were constructed using PHASE software. The data obtained from the above-said analyses was subjected to suitable statistical analyses. sP-selectin levels (ng/ml) were significantly higher in patients as compared to controls (p < 0.001). Out of total, 22% of patients were found to have very high vascular risk, 43.2% with high vascular risk, while 34.4% with moderate vascular risk. For both rs6136 and rs6127, frequency of variant allele was found to be significantly higher in patients as compared to controls and accounted for 2.4- and 1.5-fold risk of disease development, respectively. CAG was found to be associated with 4.5-fold risk towards disease development. In contrast, AGG was conferring the protective effect. Significantly high sP-levels were observed in patients with homozygous wild genotype of rs6136, all genotypes of rs6127, and heterozygous genotype of rs6125 as compared to respective controls. Significant difference was observed in P-selectin levels within moderate-risk category for rs6136. When compared between the categories, significant difference was observed for rs6136 and rs6127. Furthermore, patients with haplotypes AAA, AGA, and AGG were found to have significantly high sP-selectin levels as compared to controls. Significant difference in sP-selectin levels was observed within very high-risk as well as high-risk category. When compared between the categories, significant difference was observed for AGA and AGG haplotypes. The studied polymorphisms of SELP have shown significant association with sP-selectin levels as well as vascular risk in T2DM patients.

Resveratrol combined with total flavones of hawthorn alleviate the endothelial cells injury after coronary bypass graft surgery

OBJECTIVE

To explore the preventive and therapeutic effects of Resveratrol combined with total flavones of hawthorn, compatibility of traditional Chinese medicines, on the endothelial cells injury after artery bypass graft surgery.

METHODS

The animal model of coronary artery bypass grafting (CABG) was prepared by transplanting a segment of autologous jugular vein onto the transected common carotid artery in rabbits. After CABG surgery, the rabbits were administrated with saline (model group), aspirin (Aspirin group), resveratrol (Res group), total flavones of hawthorn (Haw group) and resveratrol combined with total flavones of hawthorn (Res+Haw group) once a day for eight weeks, respectively. Eight weeks later, the grafting arteries from all group were obtained for the pathomorphism observation, peripheral blood was collected to detect circulating endothelial cells (CECs) by flow cytometry. And the concentration of albumen and mRNA of ICAM-1 in the serum were measured by western blot and quantitative real-time polymerase chain reaction, respectively.

RESULTS

Compared with the model group, the level of CECs density and the expressions of albumen and mRNA of ICAM-1 were significantly decreased in the aspirin,resveratrol,total flavones of hawthorn and resveratrol combined with total flavones of hawthorn groups (P < .05). Of note, above all parameters were lower in Res group than aspirin group.

CONCLUSION

The Resveratrol combined with total flavones of hawthorn could protect the endothelial cells after coronary artery bypass graft.

The Interaction of Selectins and PSGL-1 as a Key Component in Thrombus Formation and Cancer Progression

Cellular interaction is inevitable in the pathomechanism of human disease. Formation of heterotypic cellular aggregates, between distinct cells of hematopoietic and nonhematopoietic origin, may be involved in events leading to inflammation and the complex process of cancer progression. Among adhesion receptors, the family of selectins with their ligands have been considered as one of the major contributors to cell-cell interactions. Consequently, the inhibition of the interplay between selectins and their ligands may have potential therapeutic benefits. In this review, we focus on the current evidence on the selectins as crucial modulators of inflammatory, thrombotic, and malignant disorders. Knowing that there is promiscuity in selectin binding, we outline the importance of a key protein that serves as a ligand for all selectins. This dimeric mucin, the P-selectin glycoprotein ligand 1 (PSGL-1), has emerged as a major player in inflammation, thrombus, and cancer development. We discuss the interaction of PSGL-1 with various selectins in physiological and pathological processes with particular emphasis on mechanisms that lead to severe disease.

Transcriptome Profiling Reveals Disruption of Innate Immunity in Chronic Heavy Ethanol Consuming Female Rhesus Macaques

It is well established that heavy ethanol consumption interferes with the immune system and inflammatory processes, resulting in increased risk for infectious and chronic diseases. However, these processes have yet to be systematically studied in a dose and sex-dependent manner. In this study, we investigated the impact of chronic heavy ethanol consumption on gene expression using RNA-seq in peripheral blood mononuclear cells isolated from female rhesus macaques with daily consumption of 4% ethanol available 22hr/day for 12 months resulting in average ethanol consumption of 4.3 g/kg/day (considered heavy drinking). Differential gene expression analysis was performed using edgeR and gene enrichment analysis using MetaCore™. We identified 1106 differentially expressed genes, meeting the criterion of ≥ two-fold change and p-value ≤ 0.05 in expression (445 up- and 661 down-regulated). Pathway analysis of the 879 genes with characterized identifiers showed that the most enriched gene ontology processes were "response to wounding", "blood coagulation", "immune system process", and "regulation of signaling". Changes in gene expression were seen despite the lack of differences in the frequency of any major immune cell subtype between ethanol and controls, suggesting that heavy ethanol consumption modulates gene expression at the cellular level rather than altering the distribution of peripheral blood mononuclear cells. Collectively, these observations provide mechanisms to explain the higher incidence of infection, delay in wound healing, and increase in cardiovascular disease seen in subjects with Alcohol use disorder.

Novel association of soluble intercellular adhesion molecule 1 and soluble P-selectin with the ABO blood group in a Chinese population

Recent studies have reported that the ABO gene can affect circulating expression levels of soluble intercellular adhesion molecule 1 (sICAM-1) and soluble P-selectin (sP-selectin) in Caucasians. However, several factors may affect the association, including the distribution and variations of the ABO gene, ethnic diversity and the inflammatory response status. The aim of the present study was to investigate this issue in Asian subjects of various blood groups. A total of 800 blood samples were randomly selected from healthy blood donors. The ABO blood groups were examined using standard serological tests, and ABO genotypes of group A and group AB specimens were analyzed. Plasma concentrations of sICAM-1 and sP-selectin were detected by standard enzyme-linked immunosorbent assays. In healthy Chinese individuals, blood group A was detected to be significantly associated with lower circulating expression levels of sICAM-1 and sP-selectin, compared with group O. Individuals with ≥1 A1 allele had significantly lower expression levels of sICAM-1 and sP-selectin compared with all other ABO groups. The data indicate the significant association of ABO blood group antigens with sICAM-1 and sP-selectin expression levels in a healthy Chinese population, independent of the specific variations and distributions of ABO blood groups among ethnic populations. This result provides evidence for the previously unidentified role of ABO blood group antigens in the regulation of the inflammatory adhesion process. Accordingly, it can be proposed that ABO blood groups may require consideration when soluble adhesion molecules are identified as predictors for cardiovascular disease.

Regular plateletpheresis increased basal concentrations of soluble P-selectin in healthy donors: Possible involvement of endothelial cell activation?

BACKGROUND

We explored the effects of repeated plateletpheresis on the platelet P-selectin expression and soluble P-selectin (sP-selectin) concentrations in platelet donors.

METHODS

Totally 289 platelet donors and 97 first-time whole blood (WB) donors were enrolled from the blood donor registry at the Fujian provincial blood center, China. The accumulative numbers of plateletpheresis in the last 2 y for participants were recorded, and the basal concentrations of platelet count, sP-selectin and total platelet P-selectin (pP-selectin) were determined.

RESULTS

Platelet donors had significantly higher basal concentrations of sP-selectin compared to WB donors (24.12±7.33ng/mL vs. 20.74±5.44ng/mL, P<0.0001), with no difference in platelet count and pP-selectin concentrations. Increased numbers of platelet donation were correlated with a steady increase of sP-selectin (r=0.18, P=0.002). Multivariate regression analysis identified that the frequency of plateletpheresis is an independent factor for the rise of the sP-selectin concentration (t=2.64, P=0.009) while no association was found for pP-selectin and platelet count.

CONCLUSIONS

Repeated plateletpheresis could result in an increased basal concentration of sP-selectin in blood donors whereas not an alteration in the concentrations of total platelet P-selectin. It remains to be determined whether this might be a consequence of endothelial activation or platelet activation or some other phenomenon.

Influence of two common polymorphisms in the EPHX1 gene on warfarin maintenance dosage: a meta-analysis

We conducted a meta-analysis to investigate the influence of two common single nucleotide polymorphisms (SNPs) (rs2292566 G>A and rs4653436 A>G) in the EPHX1 gene on warfarin maintenance dosages. Relevant literatures were searched using the PubMed, Embase, Web of Science, Cochrane Library, CISCOM, CINAHL, Google Scholar, CBM, and CNKI databases without any language restrictions. STATA Version 12.0 software (Stata Corporation, College Station, TX, USA) was used for this meta-analysis. Standard mean difference and its corresponding 95% confidence interval (95% CI) were calculated. Seven studies met the inclusion criteria, including 2,063 warfarin-treated patients. Meta-analysis results illustrated that EPHX1 rs2292566 G>A polymorphism might be strongly correlated with a higher maintenance dose of warfarin. However, no interaction of EPHX1 rs4653436 A>G polymorphism with warfarin maintenance dosage was detected. A further subgroup analysis based on stratification by ethnicity indicated that EPHX1 rs2292566 G>A polymorphism was positively correlated with warfarin maintenance dosage among Caucasians, but not Asians. No associations were observed between EPHX1 rs4653436 A>G polymorphism warfarin maintenance dosage among both Caucasians and Asians. Our meta-analysis provides robust and unambiguous evidence that EPHX1 rs2292566 polymorphism may affect the maintenance dose of warfarin in Caucasians.

Population-based study of blood biomarkers in prediction of subacute recurrent stroke

BACKGROUND AND PURPOSE

Risk of recurrent stroke is high in the first few weeks after transient ischemic attack or stroke and clinical risk prediction tools have only limited accuracy, particularly after the hyperacute phase. Previous studies of the predictive value of biomarkers have been small, been done in selected populations, and have not concentrated on the acute phase or on intensively treated populations. We aimed to determine the predictive value of a panel of blood biomarkers in intensively treated patients early after transient ischemic attack and stroke.

METHODS

We studied 14 blood biomarkers related to inflammation, thrombosis, atherogenesis, and cardiac or neuronal cell damage in early transient ischemic attack or ischemic stroke in a population-based study (Oxford Vascular Study). Biomarker levels were related to 90-day risk of recurrent stroke as hazard ratio (95% confidence interval) per decile increase, adjusted for age and sex.

RESULTS

Among 1292 eligible patients, there were 53 recurrent ischemic strokes within 90 days. There were moderate correlations (r=0.40-0.61; P<0.0001) between the inflammatory biomarkers and between the cell damage and thrombotic subsets. Associations with risk of early recurrent stroke were weak, with significant associations limited to interleukin-6 (adjusted hazard ratio, 1.12; 1.01-1.24; P=0.033) and C-reactive protein (adjusted hazard ratio, 1.15; 1.02-1.30; P=0.022) after adjusting for age, sex, hypertension, smoking, and diabetes mellitus although P-selectin seemed to predict stroke after transient ischemic attack (adjusted hazard ratio, 1.28; 1.00-1.63; P=0.046).

CONCLUSIONS

In the largest study to date, we found limited predictive use for early recurrent stroke for a panel of inflammatory, thrombotic, and cell damage biomarkers.

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.

SELP genetic polymorphisms may contribute to the pathogenesis of coronary heart disease and myocardial infarction: a meta-analysis

We conducted a meta-analysis of case-control studies to determine whether SELP genetic polymorphisms contribute to the pathogenesis of coronary heart disease (CHD) and myocardial infarction (MI). A range of electronic databases were searched: MEDLINE (1966-2013), the Cochrane Library Database (Issue 12, 2013), EMBASE (1980-2013), CINAHL (1982-2013), Web of Science (1945-2013) and the Chinese biomedical database (1982-2013) without language restrictions. Meta-analysis was performed with the use of the STATA statistical software. Nine case-control studies with a total of 3,154 CHD patients, 1,608 MI patients and 17,304 healthy controls were involved in this meta-analysis. Six common polymorphisms in the SELE gene were assessed, including -1969G/A (rs1800805 G>A), -1817T/C (rs1800808 T>C), -2123C/G (rs1800807 C>G), Thr715Pro (rs6136 A>C), Leu599Val (rs6133 G>T), and Ser290Asn (rs6131 C>T). Our findings illustrated significantly positive associations of SELE genetic polymorphisms with the development of CHD and MI. The results of subgroup analysis by SNP type indicated that -1969G/A, -1817T/C, -2123C/G, Thr715Pro and Ser290Asn in the SELP gene might be strongly correlated with CHD and MI risk, but no similar results were found in SELP Leu599Val polymorphism. In the subgroup analysis by ethnicity, our results indicated significant relationships between SELE genetic polymorphisms and the pathogenesis of CHD and MI among Asians and Caucasians. However, we observed no significant associations between SELP genetic polymorphisms and the risk of CHD and MI among Africans. Our findings provide empirical evidence that SELE genetic polymorphisms may contribute to the pathogenesis of CHD and MI, especially among Asians and Caucasians. Thus, SELP genetic polymorphisms could be potential and practical biomarkers for early diagnosis of CHD and MI.

Heterogeneous effect of two selectin gene polymorphisms on coronary artery disease risk: a meta-analysis

Background

The selectins play important roles in the inflammatory process of coronary artery disease (CAD) and myocardial infarction (MI). Previous studies have shown ambiguous findings regarding a possible association between the selectin genes and CAD. The E-selectin Ser128Arg polymorphism and the P-selectin Thr715Pro polymorphism have been investigated widely but with inconsistent results. We performed a comprehensive meta-analysis to shed light on this issue.

Methods

Data were extracted by searches of MEDLINE, Embase, CNKI, Wanfang, Google Scholar, PORTA, GeNii, CiNii, J-STAGE, Nurimedia and Koreanstudies Information Service System [Kiss] up to October 2013, in which 10 studies on the Ser128Arg polymorphism with 3369 cases and 2577 controls and 10 studies on the Thr715Pro polymorphism with 5886 cases and 18345 controls. A random-effects model was used to calculate the combined odds ratios. The between-study heterogeneity and publication bias were addressed.

Results

The 128Arg carriers had a significant increased risk of CAD (allele comparison: P = 0.02, OR = 1.33, 95%CI 1.04–1.69, P_{heterogeneity} = 0.01); The 715Pro conferred a non-significant risk reduction relative to the 715Thr (allele comparison: P = 0.40, OR = 0.94, 95%CI 0.82–1.08, P_{heterogeneity} = 0.03).Subgroup analyses demonstrated that the 128Arg carriers had a significant increased risk of CAD among Asians (allele comparison: P = 0.001, OR = 2.07, 95%CI 1.33–3.24, P_{heterogeneity} = 0.77) but not among Caucasians (allele comparison: P = 0.33, OR = 1.13, 95%CI 0.88–1.45, P_{heterogeneity} = 0.08). Carrier status for the 715Pro was significantly associated with reduced risk of MI (allele comparison: P = 0.04, OR =  0.81, 95%CI 0.67–0.99, P_{heterogeneity} = 0.14). The asymmetric funnel plot and the Egger's test (P = 0.041) suggested the presence of publication bias for the Ser128Arg polymorphism.

Conclusion

Our results suggested there is an increase in the risk of CAD conferred by the Ser128Arg polymorphism and the thr715Pro polymorphism may be a protective factor of MI.

The Thr715Pro variant impairs terminal glycosylation of P-selectin

P-selectin variant 715Pro is associated with lower concentrations of plasma P-selectin and reduced risk for thrombosis. We examined the influence of 715Pro on P-selectin synthesis, post-translational processing, surface expression and function using HEK293 cells, which do not express endogenous P-selectin. Mass spectrometry revealed that HEK293 cells produced recombinant P-selectin which has a glycosylation pattern comparable to platelet P-selectin. Compared to wild-type transfectants, 715Pro transfectants have ~50% less terminally glycosylated P-selectin and accumulate more immature P-selectin in Golgi. Following Brefeldin A treatment, the majority of 715Pro P-selectin is not modified by Golgi enzymes, while wild-type P-selectin undergoes complete modification. Flow cytometry revealed that 715Pro transfectants have ~20% less P-selectin on the cell surface compared to wild-type transfectants. Secretion of P-selectin by 715Pro transfectants was about 38% lower compared to wild-type transfectants. Binding of HL-60 cells to 715Pro transfectants was ~29% lower than to wild-type transfectants. This observation was confirmed by the presence of fewer platelet-monocyte aggregates (PMA) in the blood of healthy individuals and patients with angiographically proven atherosclerosis, carrying 715Pro P-selectin compared to individuals with wild-type P-selectin. We conclude that the 715Pro variant impairs terminal glycosylation of P-selectin in Golgi, leading to reduced amounts of mature P-selectin and subsequently less surface expression and secretion of P-selectin. The reduced surface expression of 715Pro P-selectin contributes to inefficient adhesion to HL-60 cells or monocytes.

Contribution of SELP and PSGL-1 genotypes and haplotypes to the presence of coronary heart disease in Tunisians

P-selectin (SELP) and its counter-receptor, P-selectin glycoprotein ligand-1 (PSGL-1), play key role in the transient attachment of leukocytes to endothelial cells predisposing to coronary heart disease (CHD). In the current report, 293 angiographically proven CHD patients and 327 age, gender, and race-matched controls were included. Our aim was to evaluate the contribution to CHD of the following SNPs: C-2123G, G-1969A and T715P in SELP, Met62Ile and the VNTR variants in PSGL-1 gene in a North African population from Tunisia. While there were no significant differences in the distribution of SELP or PSGL-1 alleles or genotypes between patients and controls, a trend for a significant association of the C-2123G genotypes distribution with incident CHD was observed (P=0.06). Assuming an additive model of transmission, the risk was 74% higher among subjects carrying the GG genotypes in comparison to those carrying the CC genotype (OR=1.74 [1.01-2.98], P=0.04) and 80% higher in the recessive model (OR=1.80 [1.08-3.01], P=0.02). Haplotype analysis did not identify any specific SELP or PSGL-1 haplotypes to be associated with CHD. The present study demonstrated no evidence of association between individual SELP or PSGL-1 SNPs or haplotypes with incident CHD. However, this study replicates absence of association of the mostly studied SNP, T715P, previously reported in individuals with African origin.

Detection of a large deletion in the P-selectin (SELP) gene

P-selectin is an adhesion molecule involved in the pathogenesis of inflammation, thrombosis, and oncogenesis. In this study of 51 polymorphisms in candidate genes for cardiovascular disease in 1561 individuals, we identified a new allelic variant of the SELP gene, g.18196_20704del, that determined the lack of genotyping for one polymorphism in one individual. It is a deletion of 2509 nucleotides which starts in intron 6 and ends in intron 8. Re-genotyping of 1023 apparent homozygotes indicated an overall allele frequency of 0.27%. The inclusion of this allelic variant in genetic association studies will avoid genotyping errors and marginally improve the sensitivity.

P-selectin 1087G/A polymorphism is associated with neuropsychological test performance in older adults with cardiovascular disease

BACKGROUND AND PURPOSE

There is growing evidence that the cell adhesion molecule P-selectin (SELP) contributes to the adverse vascular processes that promote cognitive impairment in individuals with cardiovascular disease. Previous research has shown that SELP genotypes moderate circulating levels of P-selectin and that patients undergoing coronary artery bypass graft with the SELP 1087A allele were less likely to show postoperative cognitive decline and more likely to exhibit lower levels of C-reactive protein than noncarriers. Thus, we expected that carriers of the 1087A allele (n=43) would exhibit better cognitive functioning than persons with 2 1087G alleles (n=77) and that C-reactive protein levels would be important for this relationship.

METHODS

One hundred twenty older adults with diagnosed cardiovascular disease were recruited from outpatient cardiology clinics. Each participant underwent a comprehensive neuropsychological test battery and a blood draw.

RESULTS

Participants with the SELP 1087A allele performed more poorly on tests of attention (Trail Making Test A: t[116]=3.20, P=0.002), executive function (Trail Making Test B: t[116]=2.89, P=0.005), psychomotor speed (Digit-Symbol Coding: t[117]=2.54, P=0.012), and memory (California Verbal Learning Test Discrimination: t[116]=2.05, P=0.04). There were no significant differences between the SELP genotype groups on demographic/medical variables or C-reactive protein levels.

CONCLUSIONS

Contrary to expectations, the present analyses showed that older patients with cardiovascular disease with the SELP 1087A allele performed more poorly on neuropsychological testing. Findings from the present study were counter to previous research with coronary artery bypass graft candidates. Further work using neuroimaging and alternative measures of cardiovascular function is needed to clarify the mechanisms of this association.

SELP and SELPLG genetic variation is associated with cell surface measures of SELP and SELPLG: the Atherosclerosis Risk in Communities Carotid MRI Study

BACKGROUND

P-selectin (SELP) and its ligand, P-selectin glycoprotein ligand 1 (SELPLG), play key roles in both the inflammatory response and the atherosclerotic process. Previous studies have shown genetic variation in the SELP gene [selectin P (granule membrane protein 140 kDa, antigen CD62)] to be associated with plasma SELP concentrations; however, the major biological function of SELP (and SELPLG) is at the cell surface. We therefore investigated the association of SELP polymorphisms with platelet SELP measures and polymorphisms in the SELPLG gene (selectin P ligand) with lymphocyte, granulocyte, and monocyte SELPLG measures among 1870 participants in the Atherosclerosis Risk in Communities (ARIC) Carotid MRI Study.

METHODS

Whole-blood flow cytometry was used to analyze leukocyte and platelet markers in the ARIC Carotid MRI Study. The allele frequencies for the SELP and SELPLG polymorphisms of whites and African Americans were markedly different; therefore, all analyses were race specific.

RESULTS

SELP T715P was significantly associated with lower values for platelet SELP measures in whites (P = 0.0001), whereas SELP N562D was significantly associated with higher values for SELP measures in African Americans (P = 0.02). SELPLG M62I was significantly associated with lower granulocyte and monocyte SELPLG measures in African Americans (P = 0.003 and P = 0.0002, respectively) and with lower lymphocyte SELPLG measures in whites (P = 0.01).

CONCLUSIONS

Specific SELP and SELPLG polymorphisms were associated with cell surface measures of SELP and SELPLG in both whites and African Americans in the ARIC Carotid MRI Study. To our knowledge, this study is the first to examine the association of SELP and SELPLG genetic variation with measures of cell surface SELP and SELPLG.

P-selectin gene polymorphisms and risk of coronary heart disease among Tunisians

P-selectin plays a key role in inflammation and atherosclerosis, and polymorphic variants of P-selectin were implicated in the pathogenesis of atherosclerotic and inflammatory changes, including coronary heart disease (CHD) in many ethnic groups. We investigated the contribution of P-selectin promoter (-2123C/G, -1969G/A) and exon (Ser290Asn, Asn562Asp, Thr715Pro) polymorphisms to CHD genetic susceptibility among 298 Tunisian CHD patients and 339 controls. Minor allele and genotype frequencies of the five P-selectin SNPs were comparable between patients and controls, except for -2123G/G genotype which was more frequent in cases. The 715Pro allele was present at lower frequency in Tunisians than in Europeans, and was not protective of CHD. Linkage disequilibrium was seen between -1969G/A, and both Ser290Asn and Asn562Asp. Five-loci haplotype analysis did not identify any CHD-protective or CHD-susceptible haplotypes. To our knowledge, this was the first case-control study to be performed on an Arab/North-African population, and demonstrates that none of the five P-selectin polymorphisms investigated influence CHD susceptibility in Tunisian Arabs.

Soluble P-selectin, SELP polymorphisms, and atherosclerotic risk in European-American and African-African young adults: the Coronary Artery Risk Development in Young Adults (CARDIA) Study

OBJECTIVE

To characterize the genetic and clinical correlates of soluble P-selectin, and the relationship of P-selectin to atherosclerotic risk, in young European-American (EA) and African-American (AA) adults.

METHODS AND RESULTS

We assessed the interrelationships between 25 common SELP polymorphisms, soluble P-selectin, and atherosclerotic risk in 1222 EA and 1072 AA from the longitudinal population-based CARDIA study. Male sex, smoking, blood pressure, and metabolic status were strong cross-sectional correlates of soluble P-selectin among CARDIA subjects aged 33 to 45 years, explaining 13% of the variance. Among EAs, higher soluble P-selectin predicted carotid intima-media thickness (IMT) measured 5 years later, even after accounting for traditional risk factors. Common SELP nucleotide sequence variants explained 11% and 5% of the interindividual variation in soluble P-selectin levels in EAs and AAs, respectively. Four distinct variants contributed to P-selectin phenotype in EAs, including a polymorphism of the 5' SELP haplotype block associated with carotid IMT. Half of the phenotypic variation attributable to SELP in EAs could be explained by the Thr715Pro polymorphism, whereas Val599Leu was more strongly associated with soluble P-selectin among AAs.

CONCLUSIONS

Common SELP polymorphisms were associated with soluble P-selectin and carotid IMT in young adults, but the patterns of association differed between EAs and AAs. These results support the role of P-selectin in the preclinical stages of atherosclerosis.

P-selectin polymorphisms' influences on P-selectin serum concentrations and on their familial correlation: the STANISLAS family study

BACKGROUND

P-selectin is an adhesion molecule known to be involved in the pathogenesis of several diseases through its major role in the initial phase of leukocytes recruitment during inflammation. However, genetic characterization of soluble P-selectin remains unclear.

OBJECTIVES

In the STANISLAS cohort, we study the familial correlations of P-selectin levels and investigate the association of six P-selectin polymorphisms (C-2123G, A-1969G, S290N, N562D, V599L and T715P) and cardiovascular risk factors with P-selectin concentrations.

PATIENTS/METHODS

Full phenotypic and genotypic information was available for 136 healthy families composed of both natural parents and at least one child (boys, n = 125; and girls, n = 139) aged more than 4 years.

RESULTS

While no correlation was observed between spouses, family correlations of P-selectin concentrations were highly significant for sibling (0.50 +/- 0.12, P < 10(-3)) and child-parent pairs (0.42 +/- 0.04, P < 10(-3)). P-selectin haplotypes explained about 25% of the variability of P-selectin concentrations, this effect being mainly due to the additive effects of two polymorphisms, V599L and T715P. After adjusting for the effect of the P-selectin polymorphisms, the sibling and child-parent correlations decreased to (0.39 +/- 0.08, P < 10(-4)) and (0.32 +/- 0.06, P < 10(-4)), respectively.

CONCLUSIONS

In the present study, we showed that two P-selectin polymorphisms, V599L and T715P, explained about 25% of the variability of P-selectin concentrations and accounted for about 40% of their family resemblance. These results would suggest a genetic influence on P-selectin concentrations beyond the contribution of the P-selectin gene.

Selectin haplotypes and the risk of venous thrombosis: influence of linkage disequilibrium with the factor V Leiden mutation

BACKGROUND

Selectins (E-, L- and P-selectin) and their most important counter-receptor P-selectin glycoprotein ligand (SELPLG) facilitate the interaction of platelets, leukocytes and endothelial cells at inflammatory sites. Selectin polymorphisms/haplotypes have been associated with cardiovascular disease.

OBJECTIVES

We investigated the association between haplotypes (H) of these four genes and deep venous thrombosis (DVT) risk. We additionally explored the effect of linkage disequilibrium (LD) with the nearby Factor V Leiden mutation (FVL). Furthermore, interactions between SELPLG polymorphisms and selectin polymorphisms were investigated.

PATIENTS/METHODS

Leiden Thrombophilia Study (LETS) subjects were genotyped for 24 polymorphisms by TaqMan or PCR-RFLP, detecting all common haplotypes in four blocks. P-selectin was analyzed in two blocks, upstream (SELPup) and downstream (SELPdown) of the recombination hotspot.

RESULTS

In E- and L-selectin, none of the haplotypes was associated with DVT risk. In SELPup, H2-carriers had a 1.3-fold increased risk (95% CI, 1.0-1.7), whereas H4-carriers had a 1.4-fold decreased risk (95% CI, 0.5-1.0). In SELPdown, H2-carriers had a 1.3-fold increased risk (95% CI, 1.0-1.7). Because of LD with FVL, we subsequently excluded all FVL-carriers and all risks disappeared. Mutual adjustment within a logistic regression model resulted in disappearance of the risks for the SELP haplotypes, whereas FVL risk remained.

CONCLUSIONS

After adjustment for LD with FVL, none of the selectin haplotypes was associated with DVT risk, showing that the increased risks of the selectin haplotypes were a reflection of the effect of FVL on thrombosis risk.

Clinical and genetic correlates of soluble P-selectin in the community

BACKGROUND

P-selectin is a cell adhesion molecule that is involved in atherogenesis, and soluble concentrations of this biomarker reflect cardiovascular risk. However, the clinical correlates and genetic characterization of soluble P-selectin have not been clearly elucidated.

OBJECTIVE

To describe clinical and genetic correlates of circulating P-selectin in the community.

METHODS

In Framingham Heart Study Offspring (European descent) and Omni (ethnic/racial minority) participants, we examined the association of cardiovascular risk factors with soluble P-selectin concentrations. In Offspring participants, we evaluated heritability, linkage and association of 29 SELP single-nucleotide polymorphisms (SNPs) with adjusted P-selectin concentrations.

RESULTS

In multivariable analysis of 3,690 participants (54% women, mean age 60 +/- 10 years), higher log-transformed P-selectin concentrations were inversely associated with female sex and hormone replacement therapy, and positively associated with age, ethnic/racial minority status, cigarette smoking, waist circumference, systolic blood pressure, fasting glucose, and total/high-density lipoprotein cholesterol and triglyceride concentrations. Clinical factors explained 10.4% of the interindividual variability in P-selectin concentrations. In 571 extended pedigrees (n = 1,841) with >or= 2 phenotyped members per family, multivariable-adjusted heritability was 45.4 +/- 5.8%. Among the SELP SNPs examined, a non-synonymous SNP (rs6136) encoding a threonine-to-proline substitution at position 715 was highly significantly associated with decreased P-selectin concentrations (P = 5.2 x 10(-39)), explaining 9.7% of variation after adjustment for clinical factors.

CONCLUSIONS

Multiple clinical factors and an SNP in the SELP gene were significantly associated with circulating P-selectin concentrations. One SNP in SELP explained significant variation in circulating P-selectin concentrations, even after accounting for known clinical correlates.

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

Inflammation has recently proven to be associated with the pathogenesis of atherosclerosis and inflammatory genes are good candidates for the risk of developing atherosclerosis. The early phase of atherosclerosis involves the recruitment of inflammatory cells from the circulation and their transendothelial migration. This process is mainly mediated by cellular adhesion molecules. The adhesion molecule P-selectin may play a role in the pathogenesis of atherosclerosis. Polymorphism of P-selectin gene, which may affect the production level of the adhesion molecule, has been associated with a number of atherosclerotic disease. To test this hypothesis, we investigated the relationship of P-selectin gene polymorphisms and ischemic stroke in a Chinese population. We analyzed single nucleotide polymorphisms of P-selectin gene -2,123 G/C, -1,969 G/A, -1,817 T/C and Thr715Pro in three hundred and five patients with ischemic stroke and 280 age and sex matched controls, using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and DNA sequencing method. There were no significant differences in the genotype, allele and haplotype frequencies of P-selectin gene polymorphisms between the group of patients with ischemic stroke and the control group. Furthermore, there was no significant association of genotype, allele and haplotype at any of the polymorphism in relation to any subtype of ischemic stroke. We did not observe an association between P-selectin gene polymorphisms and ischemic stroke or any subtype of ischemic stroke. However, further studies are needed to explore the complex interaction between environmental factors and P-selectin gene polymorphisms in the risk of ischemic stroke, particularly in ethnically different populations.

Specific P-selectin and P-selectin glycoprotein ligand-1 genotypes/haplotypes are associated with risk of incident CHD and ischemic stroke: the Atherosclerosis Risk in Communities (ARIC) study

OBJECTIVE

P-selectin (PSEL) and its ligand, P-selectin glycoprotein ligand-1 (PSGL-1), play key roles in both the inflammatory response and the atherosclerotic process, but there are conflicting results regarding the affect of PSEL and PSGL-1 gene variation on risk for cardiovascular and cerebrovascular disease. We tested the association of four PSEL and two PSGL-1 polymorphisms with incident coronary heart disease (CHD) and ischemic stroke among 13,875 participants in the prospective Atherosclerosis Risk in Communities (ARIC) study. We also tested common haplotypes in the PSEL and PSGL-1 genes to assess associations with incident CHD and ischemic stroke.

METHODS AND RESULTS

Incident ischemic stroke and CHD were identified through annual telephone calls and hospital and death certificate surveillance. Five hundred and twenty-five validated ischemic stroke and 1654 CHD events were identified. Allele frequencies for all PSEL and PSGL-1 polymorphisms were markedly different between whites and African Americans; therefore, all analyses were performed race-specific. Independent analyses showed the PSEL 290NN genotype to be a significant predictor of CHD in whites (HRR 1.30, 95%CI 1.00-1.70, P=0.05). PSGL-1 genotypes carrying the 62I allele were significantly protective for incident CHD (HRR 0.53, 95%CI 0.31-0.92, P=0.02) and ischemic stroke (HRR 0.73, 95%CI 0.55-0.97, P=0.03) in African Americans. Haplotype analyses showed the PSEL NNVP haplotype to be a significant predictor of incident CHD in whites (HRR 2.09, 95%CI 1.23-3.55, P=0.006). No significant haplotype findings were observed in African Americans.

CONCLUSIONS

PSEL S290N, in single polymorphism analysis and in the haplotypic background with T715P, was associated with increased risk of incident CHD in whites. The PSGL-1 M62I polymorphism was associated with decreased risk of both incident CHD and stroke in African Americans. These findings illustrate the complex relationship between genetic variation and disease in different racial groups.

High concentrations of soluble P-selectin are associated with risk of venous thromboembolism and the P-selectin Thr715 variant

BACKGROUND

The cell adhesion molecule P-selectin has an important role in the pathophysiology of thrombosis. The effect on venous thromboembolism (VTE) of increased circulating concentrations of soluble P-selectin (sP-selectin) and their association with the P-selectin variant Thr715Pro is still uncertain.

METHODS

This study was a case-control study of 116 patients with confirmed recurrent VTE and at least 1 event of unprovoked deep venous thrombosis or pulmonary embolism, and 129 age- and sex-matched healthy individuals. We measured sP-selectin by ELISA and P-selectin gene (SELP) variation by genotyping and sampled blood after a mean interval of 2.55 years after the most recent VTE event.

RESULTS

The mean (SD) sP-selectin concentration was higher in patients than in controls: 47.3 (15.0) microg/L vs 36.8 (11.0) microg/L, P <0.001. The unadjusted odds ratio (OR) for sP-selectin >55.1 microg/L, representing the 95th percentile for controls, was 8.5 (95% CI, 3.7-23.3; P <0.001) and increased after adjustment for factor V Leiden, the prothrombin G20210A variant, increased factor VIII, and hyperhomocysteinemia (OR, 10.6; 95% CI, 4.1-31.2; P <0.001). Pro715 carriers were more prevalent among controls than patients (21.7% vs 14.7%). sP-selectin concentrations were lower in this subgroup than in noncarriers: 31.3 (7.9) microg/L vs 44.1 (14.1) microg/L; P <0.001).

CONCLUSIONS

Increased sP-selectin concentrations are associated with VTE and genotype status. sP-selectin concentrations are lower in individuals carrying the P-selectin Pro715 variant than in those without this variant.

Genetic Variants in P-Selectin and C-Reactive Protein Influence Susceptibility to Cognitive Decline After Cardiac Surgery

OBJECTIVES

We hypothesized that candidate gene polymorphisms in biologic pathways regulating inflammation, cell matrix adhesion/interaction, coagulation-thrombosis, lipid metabolism, and vascular reactivity are associated with postoperative cognitive deficit (POCD).

BACKGROUND

Cognitive decline is a common complication of coronary artery bypass graft (CABG) surgery and is associated with a reduced quality of life.

METHODS

In a prospective cohort study of 513 patients (86% European American) undergoing CABG surgery with cardiopulmonary bypass, a panel of 37 single-nucleotide polymorphisms (SNPs) was genotyped by mass spectrometry. Association between these SNPs and cognitive deficit at 6 weeks after surgery was tested using multiple logistic regression accounting for age, level of education, baseline cognition, and population structure. Permutation analysis was used to account for multiple testing.

RESULTS

We found that minor alleles of the CRP 1059G/C SNP (odds ratio [OR] 0.37, 95% confidence interval [CI] 0.16 to 0.78; p = 0.013) and the SELP 1087G/A SNP (OR 0.51, 95% CI 0.30 to 0.85; p = 0.011) were associated with a reduction in cognitive deficit in European Americans (n = 443). The absolute risk reduction in the observed incidence of POCD was 20.6% for carriers of the CRP 1059C allele and 15.2% for carriers of the SELP 1087A allele. Perioperative serum C-reactive protein (CRP) and degree of platelet activation were also significantly lower in patients with a copy of the minor alleles, providing biologic support for the observed allelic association.

CONCLUSIONS

The results suggest a contribution of P-selectin and CRP genes in modulating susceptibility to cognitive decline after cardiac surgery, with potential implications for identifying populations at risk who might benefit from targeted perioperative antiinflammatory strategies.

Genetic susceptibility to thrombosis

Thrombosis is associated with atherosclerosis, sepsis, cancer, and numerous other inflammatory diseases. Complications of thrombosis, such as myocardial infarction, stroke, and venous thromboembolism, contribute significantly to morbidity and mortality. Susceptibility to thrombosis is conferred by both genetic and environmental factors. Tissue factor is the primary cellular initiator of blood coagulation and is a major contributor to thrombosis. In this review, we discuss the association between various polymorphisms and the risk for thrombosis.

SELPLG and SELP single-nucleotide polymorphisms in multiple sclerosis

P-Selectin (SELP) and P-selectin glycoprotein ligand-1 (SELPLG) constitute a receptor/ligand complex involved in the recruitment of activated lymphocytes, a critical event in the pathogenesis of multiple sclerosis (MS). In order to determine whether genetic variation in these pivotal molecules influences susceptibility to MS, we genotyped 214 Italian patients compared with 220 Italian controls for three single-nucleotide polymorphisms (SNPs): SELPLG Met62Ile, SELP C-2123G and SELP Thr715Pro. No significant differences in both SELP SNPs were found between patients and controls, whereas a decreased frequency of the Met62Ile SNP was found in patients versus controls in the Italian population (P = 0.025). To confirm these preliminary findings, the Met62Ile SNP was analysed in 938 UK trio families. This SNP did not show evidence for association with susceptibility to MS in the larger UK cohort. Therefore, none of the SNPs investigated is associated with MS, although this analysis does not conclusively exclude SELPLG and SELP as genetic risk factors for MS as much variation remains untested.

P-selectin gene haplotype associations with albuminuria in the Diabetes Heart Study

BACKGROUND

Adhesion molecules, such as P-selectin, play a pivotal role in leukocyte adhesion to the endothelium during inflammation. We investigated the relationship between P-selectin gene polymorphisms and albuminuria in 565 European American siblings (84% with type 2 diabetes) from 227 families participating in the Diabetes Heart Study (DHS).

METHODS

Three common missense P-selectin polymorphisms (S290N, N562D, and T715P) were genotyped. Albuminuria was defined as an albumin:creatinine ratio (ACR) > or = 17 mg/g in males, and > or = 25 mg/g in females. Tests of association were based on generalized estimating equations (GEE1) and tests of linkage disequilibrium were based on the quantitative pedigree disequilibrium test (QPDT).

RESULTS

Each copy of the 290Asn (S290N) allele was associated with a 45% absolute increase in ACR (P= 0.007), and a higher risk for the presence of albuminuria [odds ratio (OR), 1.71 for each 290A sn allele] (P= 0.002). Adjustment for other determinants of ACR, including stratification by age, gender, and presence of diabetes, did not alter these results. Haploytpe analyses using both GEE1 and QPDT methods revealed that the N-N-T haplotype, containing asparagine codons at sites S290N and N562D, was associated with an increased risk of albuminuria (OR 1.77) (P= 0.005, for each additional copy of the N-N-T haplotype).

CONCLUSION

The 290Asn (S290N) variant of P-selectin was associated with a higher prevalence and greater degree of albuminuria in European American siblings of type 2 diabetic families.

Interaction between inflammation-related gene polymorphisms and cigarette smoking on the risk of myocardial infarction in the Physician’s Health Study

Inflammation is known to be a major component of atherosclerosis, and cigarette smoking is known to induce a systemic inflammatory response. We therefore, investigated possible gene-environment interactions between various inflammation-related gene polymorphisms and cigarette smoking on the risk of myocardial infarction (MI) in the Physician's Health Study (PHS), a cohort of initially healthy middle-aged men. We used a nested case-control design consisting of 522 MI cases and 2,089 controls derived from PHS. Eleven inflammatory polymorphisms were studied using logistic regression analysis: eotaxin (ala23thr), intercellular adhesion molecule 1 (gly241arg), interleukin-4 (582C>T), interleukin-4 receptor (ile75val, gln576arg), interleukin-6 (-174G>C), interleukin-10 (-571C>A), P-selectin (val640leu, thr756pro, ser330asn), and vascular cell adhesion molecule 1 (-1594T>C). Interactions of smoking with all the three modes of inheritance (additive, dominant, recessive) were tested. Statistically significant (P<0.05) interaction terms were found for interleukin-4 receptor (ile75val), with odds ratios of 0.52 (95%CI:0.29-0.95) for Ile-Val and 0.34 (95%CI:0.14-0.83) for Val-Val, compared to the wildtype Ile-Ile; for interleukin-6 (-174G>C) with odds ratios of 2.16 (1.14-4.09) for GC and 0.81 (0.31-2.12) for CC, compared to the wildtype GG; and for P-selectin (ser330asn) with odds ratios of 0.48 (0.24-0.95) for Ser-Asn and 1.08 (0.29-3.93) for Asn-Asn, compared to the wildtype Ser-Ser, with these effects occurring only among the smokers. These data raise the possibility of interaction between the smoking status and certain inflammatory polymorphisms on the risk of MI in men. However, these results should be interpreted with caution due to the potential for false positive results that can arise from analyses with multiple comparisons.

P-selectin Thr715Pro polymorphism predicts P-selectin levels but not risk of incident coronary heart disease or ischemic stroke in a cohort of 14595 participants: the Atherosclerosis Risk in Communities Study

OBJECTIVE

Inflammation, characterized by the recruitment/adhesion of circulating leukocytes by cellular adhesion molecules, plays an important role in the pathogenesis of atherosclerosis. Genetic analyses of P-selectin, a key adhesion molecule in the progression of atherosclerosis, have provided conflicting results regarding the role of variation within the P-selectin gene and risk for heart disease. No studies have examined the association of this polymorphism with stroke. Therefore, we examined the association of the P-selectin Thr715Pro polymorphism with incident coronary heart disease (CHD) and ischemic stroke among 14595 participants in the prospective cohort of the Atherosclerosis Risk in Communities (ARIC) Study.

METHODS AND RESULTS

Incidences of ischemic stroke and CHD were determined through annual telephone calls and hospital and death certificate surveillance. Four hundred fifty-six validated ischemic stroke and 1533 CHD events were identified. P-selectin Pro715 allele frequency was determined in whites and African-Americans, respectively, for CHD cases (0.11, 0.02), CHD non-cases (0.11, 0.02), ischemic stroke cases (0.11, 0.02) and stroke non-cases (0.11, 0.02). The P-selectin Pro715 allele was not associated with risk of CHD or stroke in whites or African-Americans. P-selectin levels, however, were associated with the P-selectin Thr715Pro variant in whites, but not in African-Americans.

CONCLUSIONS

Genotypes carrying the P-selectin Pro715 variant allele are associated with decreased P-selectin levels compared to the homozygous wild-type genotype in whites. The P-selectin Thr715Pro polymorphism is not associated with incident CHD or ischemic stroke in either whites or African-Americans.

Quantitative genetic analysis of cellular adhesion molecules: the Fels Longitudinal Study

Circulating concentrations of inflammatory markers predict cardiovascular disease (CVD) risk and are closely associated with obesity. However, little is known concerning genetic influences on serum levels of inflammatory markers. In this study, we estimated the heritability (h2) of soluble cellular adhesion molecule (sCAM) concentrations and examined the correlational architecture between different sCAMs. The study population included 234 men and 270 women aged 18-76 years, belonging to 121 families participating in the Fels Longitudinal Study. Serum levels of soluble intercellular adhesion molecule-1 (sICAM-1), vascular cell adhesion molecule-1 (sVCAM-1), E-selectin (sESEL-1) and P-selectin (sPSEL-1) were assayed using commercially available kits. A variance components-based maximum likelihood method was used to estimate the h2 of the different serum inflammatory markers while simultaneously adjusting for the effects of known CVD risk factors, such as age and smoking. Additionally, we used bivariate extensions of these methods to estimate genetic and random environmental correlations among sCAMs. Levels of sCAMs were significantly heritable: h2=0.24+/-0.10 for sICAM-1, h2=0.22+/-0.10 for sVCAM-1, h2=0.50+/-0.11 for sESEL-1, and h2=0.46+/-0.10 for sPSEL-1. In addition, a significant genetic correlation (rho(G)=0.63) was found between sICAM-1 and sVCAM-1 indicating some degree of shared genetic control. In the Fels Longitudinal Study, the levels of four sCAMs are significantly influenced by genetic effects, and sICAM-1 shares a common genetic background with sVCAM-1.

Candidate-based proteomics in the search for biomarkers of cardiovascular disease

The key concept of proteomics (looking at many proteins at once) opens new avenues in the search for clinically useful biomarkers of disease, treatment response and ageing. As the number of proteins that can be detected in plasma or serum (the primary clinical diagnostic samples) increases towards 1000, a paradoxical decline has occurred in the number of new protein markers approved for diagnostic use in clinical laboratories. This review explores the limitations of current proteomics protein discovery platforms, and proposes an alternative approach, applicable to a range of biological/physiological problems, in which quantitative mass spectrometric methods developed for analytical chemistry are employed to measure limited sets of candidate markers in large sets of clinical samples. A set of 177 candidate biomarker proteins with reported associations to cardiovascular disease and stroke are presented as a starting point for such a 'directed proteomics' approach.