Association between P-selectin gene polymorphisms and soluble P-selectin levels and their relation to coronary artery disease

Proteomic-Based Platelet Activation-Associated Protein SELP May Be a Novel Biomarker for Coagulation and Prognostic in Essential Thrombocythemia

Abnormal platelet activation can lead to thrombosis in essential thrombocythemia (ET) and thus impact patient prognosis. Platelet activation-associated proteins are key molecules for platelet activation. However, it is unclear which proteins are most closely associated with the disease's prognosis. To determine which platelet activation-related proteins can be employed as ET patient prognosis predictors, we used label-free quantification (LFQ) and parallel reaction monitoring (PRM) technology and first determined the serum proteomic expression levels and the differential proteins of ET patients. Then, based on the IPSET (International Prognostic Score for ET), the differential protein associated with the prognostic score was found. To investigate potential processes affecting prognosis, the connection of this protein with prognostic markers, such as thrombotic history, age, white blood cell count, coagulation factors, and inflammatory factors, were further examined. The levels of platelet activation-related proteins GPIbα, SELP, PF4, MMP1, and FLNA were significantly higher in ET patients, according to LFQ and PRM analyses (p < 0.01). Based on regression analysis of the IPSET prognostic score, it is suggested that the SELP level was positively correlated with the prognostic score and prognostic risk factor analysis (p < 0.05). Further regression analysis of SELP with coagulation factors showed that antithrombin (AT-III) was negatively correlated with SELP levels (p < 0.05). Further regression analysis of the inflammatory factors with AT-III and SELP revealed that IL-10, IL-12P70, and IL-31 were negatively correlated with AT-III and SELP (p < 0.01). Platelet activation pathway-related proteins are expressed more frequently in ET patients, and serum SELP may be a prognostic marker for these individuals by encouraging leukocyte increase and inflammatory factor expression and causing aberrant coagulation.

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.

Increased levels of platelet activation markers are positively associated with carotid wall thickness and other atherosclerotic risk factors in obese patients

The role of platelets in the development of atherosclerosis and obesity-related prothrombotic state is still under investigation. In this cross-sectional cohort study, we measured the levels of different platelet activation markers and evaluated their relationship with carotid intima-media thickness (IMT) along with other atherosclerotic risk factors in obese patients with or without atherosclerotic co-morbidities. We enrolled 154 obese patients, including 98 with either hypertension, type 2 diabetes mellitus or dyslipidaemia, 56 without these co-morbidities and 62 age- and sex-matched healthy controls. Platelet P-selectin expression and the number of platelet-derived microparticles (PMPs) were measured by flow cytometry; soluble P-selectin levels were analysed by ELISA and Thr715Pro P-selectin polymorphism was determined by PCR-RFLP. Carotid IMT was examined by ultrasonography. The levels of platelet activation parameters were significantly elevated in all obese subjects with increased carotid IMT compared to healthy controls. There was no effect of Thr715Pro genotype on soluble P-selectin levels in obese individuals contrary to normal subjects. Significant and positive association was revealed between carotid IMT and platelet P-selectin (p<0.0001), soluble P-selectin (p=0.039) and PMP (p=0.0001) levels. After adjusting for multiple variables, independent association was found between soluble P-selectin and fibrinogen (p=0.007), PMP levels and body mass index (p<0.0001) as well as platelet P-selectin and carotid IMT (p=0.012) plus plasminogen activator inhibitor-1 (p=0.009). In conclusion, P-selectin and PMP levels showed positive associations with abnormal carotid IMT and other risk factors in obesity suggesting a critical role of enhanced platelet reactivity in atherosclerotic wall alteration.

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.

Structural and functional impact of SNPs in P-selectin gene: A comprehensive in silico analysis

P-selectin is an adhesion molecule which plays an important role in the development of inflammation. It is encoded by the SELP gene located on chromosome 1q21-q24. Various single nucleotide polymorphisms (SNPs) ofSELPhave been reported to be associated with various inflammatory disease conditions. The genetics behind these diseases could be better understood by knowing the structural and functional impact of various genetic determinants ofSELP. So far, this is the first comprehensive and systematicin silicoanalysis of SNPs inSELP. A total of 2780 SNPs ofSELPwere retrieved from NCBI dbSNP. Only conserved and validated SNPs with minor allele frequency (MAF) ≥ 0.05 were subjected to further analysis. Based on these criteria, we selected 4 non-synonymous SNPs (nsSNPs) and 119 non-coding SNPs (ncSNPs). The nsSNPs were analyzed for deleterious effects using SIFT, Polyphen-2, nsSNPAnalyzer, SNP & Go, SNPs3, Mutperd and I-mutant web tools. The template prediction for variant structure modeling was performed using MUSTER and SWISS-MODEL. The functional impact of ncSNPs was analyzed by SNPinfo and RegulomeDB. Thein silicoanalysis predicted 3 nsSNPs and 21 ncSNPs as potential candidates for future case-control association studies and functional analysis ofSELP.

ABO blood group associations with markers of endothelial dysfunction in the Multi-Ethnic Study of Atherosclerosis

BACKGROUND AND AIMS

ABO blood type is associated with cardiovascular disease, although the underlying mechanisms are presumed to be complex. While the relationship between non-O blood types and von Willebrand Factor (vWF) is well-established, associations with cellular adhesion molecules (CAMs) across diverse populations are understudied.

METHODS

We genetically inferred ABO alleles for N = 6202 participants from the Multi-Ethnic Study of Atherosclerosis. Linear regression was used to evaluate associations between major ABO allele dosages and log-transformed measurements of vWF (N = 924), soluble E-selectin (sE-selectin, N = 925), soluble P-selectin (sP-selectin, N = 2392), and soluble ICAM-1 (sICAM-1, N = 2236) by race/ethnicity.

RESULTS

For the selectins, the A1 allele was associated with significantly lower levels for all races/ethnicities, with each additional allele resulting in a 28-39% decrease in sE-selectin and 10-18% decrease in sP-selectin relative to Type O subjects. However, the A2 allele demonstrated effect heterogeneity across race/ethnicity for sE-selectin, with lower levels for non-Hispanic whites (p = 0.0011) but higher levels for Hispanics (p = 0.0021). We also identified elevated sP-selectin levels for B-allele carriers solely in Hispanic participants (p = 1.0E-04). ABO-by-race/ethnicity interactions were significant for both selectins (p < 0.0125). More modest associations were observed between A1 allele dosage and levels of sICAM-1, with ABO alleles explaining 0.8-1.1% of the total phenotypic variation within race/ethnicity. ABO associations with vWF activity were consistent across race/ethnicity, with B allele carriers corresponding to the highest vWF activity levels.

CONCLUSIONS

ABO blood type demonstrates complex associations with endothelial markers that are largely generalizable across diverse populations.

Platelets as Predictors of Vascular Risk: Is There a Practical Index of Platelet Activity?

Activated platelets play a role in the pathogenesis of coronary heart disease (CHD). Following activation, platelets change shape, aggregate, and release several bioactive substances. The aim of this review is to identify if there is a simple and cost-effective method that indicates platelet activation and predicts the risk of CHD and vascular events. The rationale for identifying high-risk patients is to reduce their risk of vascular events by administering appropriate and effective antiplatelet treatment, like aspirin, clopidogrel, or combination regimens. Many laboratory tests estimating platelet activity have been described. Some are relatively simple, such as spontaneous or agonist-induced platelet aggregation. Other tests include measuring the mean platelet volume (MPV) or plasma soluble P-selectin levels. Some more complex tests include flow cytometry to determine platelet GP Ilb/Illa receptors, platelet surface P-selectin, plateletmonocyte aggregates, and microparticles. Only few prospective studies assessed the predictive value of platelet activation in healthy individuals. Although the MPV seems an 'easy method, there are insufficient data supporting its ability to predict the risk of a vascular event in healthy adults. Platelet aggregation, in whole blood or in platelet-rich plasma was not consistently predictive of vascular risk. Soluble P-selectin measurement is a promising method but it needs further evaluation. Flow cytometry methods are costly, time-consuming, and need specialized equipment. Thus, they are unlikely to be useful in estimating the risk in large numbers of patients. There is as yet no ideal test for the detection of platelet activation. Each currently available test has merits and disadvantages. Simple methods such as the MPV and the determination of platelet release products need further evaluation.

Soluble P-Selectin During a Single Hemodialysis Session in Patients With Chronic Renal Failure and Erythropoietin Treatment

In several studies, hemodialysis (HD) patients treated with recombinant human erythropoietin (rHuEPO) because of renal anemia showed increased levels of soluble adhesion molecules. The purpose of the study was to investigate the changes of soluble P-selectin (sSELP) and its relationship to platelet activation during a single HD session in patients with long-term rHuEPO treatment. Fifty-two HD patients with chronic renal failure were involved—26 with rHuEPO treatment (EPO group) and 26 without (non-EPO group). Thirty healthy subjects served as the control group. The sSELP, β-thromboglobulin, and platelet factor 4 plasma levels were measured before and after a single 4-hour HD session on a cuprophane dialyzer. The basal β-thromboglobulin and platelet factor 4 plasma levels were significantly increased in both HD groups compared with healthy controls but did not change after a single HD session, except for a significant decrease of platelet factor 4 in the non-EPO group. The predialysis sSELP plasma levels did not differ significantly compared with those of the healthy controls, but there was a significant increase of sSELP levels after a single HD session in both groups (EPO, P < .005; non-EPO, P < .05, respectively). These results suppose that the increased sSELP level was released from platelets during the course of a single HD session. The more significant increase of the sSELP plasma levels in EPO group during HD indicates that platelets are more activated in patients with long-term rHuEPO treatment, and this fact could partially explain the suspected tendency for thrombosis in these patients.

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.

Association of ABO blood group with P-selectin levels in Chinese Han healthy volunteers

BACKGROUND

Recent genome-wide association studies in Caucasians suggested that an association exists between the ABO gene locus and soluble levels of P-selectin (sP-selectin). However, it is unclear if the relationship corresponds to the phenotypic expression of ABO groups or is present in different ethnic groups. The aim of this study was to verify this observation at both genotypic and phenotypic levels in a healthy Chinese population.

STUDY DESIGN AND METHODS

The ABO blood groups were determined by both phenotypes and genotypes in 440 healthy Chinese Han volunteers, while P-selectin levels were evaluated for sP-selectin and total platelet P-selectin (pP-selectin).

RESULTS

ABO phenotyping and quantitative analysis of individual sP-selectin plasma levels were combined to demonstrate that individuals phenotypically expressing the A antigen have approximately 20% lower sP-selectin plasma levels than those carrying the B or O phenotype (p < 0.0001), but that no difference exists between A and AB and between B and O phenotypes. Genotyping data revealed that the presence of the A gene could be attributed to the observed difference in phenotype comparison, with no difference between A/A, A/B, and A/O genotypes. There were also no associations between ABO blood groups, either phenotypes or genotypes, and pP-selectin levels.

CONCLUSION

This study demonstrated an association between sP-selectin levels and ABO groups in a Chinese Han population, implicating its generalizability to other ethnic groups. This finding will improve the understanding of the mechanism of ABO blood group-associated diseases.

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.

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.

Patterns of circulating inflammatory biomarkers in older persons with varying levels of physical performance: a partial least squares-discriminant analysis approach

Background: Chronic, low-grade inflammation and declining physical function are hallmarks of the aging process. However, previous attempts to correlate individual inflammatory biomarkers with physical performance in older people have produced mixed results. Given the complexity of the inflammatory response, the simultaneous analysis of an array of inflammatory mediators may provide more insights into the relationship between inflammation and age-related physical function decline. This study was designed to explore the association between a panel of inflammatory markers and physical performance in older adults through a multivariate statistical approach.

Methods: Community-dwelling older persons were categorized into “normal walkers” (NWs; n = 27) or “slow walkers” (SWs; n = 11) groups using 0.8 m s⁻¹ as the 4-m gait speed cutoff. A panel of 14 circulating inflammatory biomarkers was assayed by multiplex analysis. Partial least squares-discriminant analysis (PLS-DA) was used to identify patterns of inflammatory mediators associated with gait speed categories.

Results: The optimal complexity of the PLS-DA model was found to be five latent variables. The proportion of correct classification was 88.9% for NW subjects (74.1% in cross-validation) and 90.9% for SW individuals (81.8% in cross-validation). Discriminant biomarkers in the model were interleukin 8, myeloperoxidase, and tumor necrosis factor alpha (all higher in the SW group), and P-selectin, interferon gamma, and granulocyte–macrophage colony-stimulating factor (all higher in the NW group).

Conclusion: Distinct profiles of circulating inflammatory biomarkers characterize older subjects with different levels of physical performance. The dissection of these patterns may provide novel insights into the role played by inflammation in the disabling cascade and possible new targets for interventions.

Genetics of coronary heart disease with reference to ApoAI-CIII-AIV gene region

Cardiovascular diseases are affected by multiple factors like genetic as well as environmental hence they reveal factorial nature. The evidences that genetic factors are susceptible for developing cardiovascular diseases come from twin studies and familial aggregation. Different ethnic populations reveal differences in the prevalence coronary artery disease (CAD) pointing towards the genetic susceptibility. With progression in molecular techniques different developments have been made to comprehend the disease physiology. Molecular markers have also assisted to recognize genes that may provide evidences to evaluate the role of genetic factors in causation of susceptibility towards CAD. Numerous studies suggest the contribution of specific “candidate genes”, which correlate with various roles/pathways that are involved in the coronary heart disease. Different studies have revealed that there are large numbers of genes which are involved towards the predisposition of CAD. However, these reports are not consistent. One of the reasons could be weak contribution of genetic susceptibility of these genes. Genome wide associations show different chromosomal locations which dock, earlier unknown, genes which may attribute to CAD. In the present review different ApoAI-CIII-AIV gene clusters have been discussed.

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.

Correlations of SELE genetic polymorphisms with risk of coronary heart disease and myocardial infarction: a meta-analysis

This meta-analysis of case-control studies was conducted to determine whether SELE genetic polymorphisms contribute to the pathogenesis of coronary heart disease (CHD) and myocardial infarction (MI). The PubMed, CISCOM, CINAHL, Web of Science, Google Scholar, EBSCO, Cochrane Library, and CBM databases were searched for relevant articles published before November 1st, 2013 without any language restrictions. Meta-analysis was conducted using the STATA 12.0 software. Twenty case-control studies met the inclusion criteria, with a total of 2,292 CHD patients, 901 MI patients and 3,233 healthy controls. Six common polymorphisms in the SELE gene were evaluated, including 554L/F, 98G/T, 128S/R, 2692G/A, 1901C/T, and 1856A/G. The results of our meta-analysis suggest that SELE genetic polymorphisms might be strongly correlated with an increased risk of CHD (allele model: OR 2.08, 95% CI 1.67-2.58, P<0.001; dominant model: OR 2.12, 95% CI 1.68-2.68, P<0.001; respectively), especially the SELE 554L/F, 98G/T and 128S/R polymorphisms. Furthermore, our findings indicated that SELE genetic polymorphisms were closely linked to the risk of CHD in Asians but not Caucasians. However, our findings reveal no positive correlations between SELE genetic polymorphisms and MI risk (allele model: OR 1.39, 95% CI 1.00-1.94, P=0.054; dominant model: OR 1.40, 95% CI 0.96-2.04, P=0.081; respectively). The current meta-analysis suggests that SELE genetic polymorphisms may contribute to an increased risk of CHD, especially the SELE 554L/F, 98G/T and 128S/R polymorphisms in Asians. However, SELE genetic polymorphisms may not be important determinants of susceptibility to MI.

Pharmacogenomic association of nonsynonymous SNPs in SIGLEC12, A1BG, and the selectin region and cardiovascular outcomes

We sought to identify novel pharmacogenetic markers associated with cardiovascular outcomes in patients with hypertension on antihypertensive therapy. We genotyped a 1:4 case:control cohort (n=1345) on the Illumina HumanCVD Beadchip from the INternational VErapamil SR-Trandolapril STudy (INVEST), where participants were randomized to a β-blocker strategy or a calcium channel blocker strategy. Genome-spanning single nucleotide polymorphism (SNP)×treatment interaction analyses of nonsynonymous SNPs were conducted in white and Hispanic race/ethnic groups. Top hits from whites were tested in Hispanics for consistency. A genetic risk score was constructed from the top 3 signals and tested in the Nordic Diltiazem study. SIGLEC12 rs16982743 and A1BG rs893184 had a significant interaction with treatment strategy for adverse cardiovascular outcomes (INVEST whites and Hispanics combined interaction P=0.0038 and 0.0036, respectively). A genetic risk score, including rs16982743, rs893184, and rs4525 in F5, was significantly associated with treatment-related adverse cardiovascular outcomes in whites and Hispanics from the INVEST study and in the Nordic Diltiazem study (meta-analysis interaction P=2.39×10(-5)). In patients with a genetic risk score of 0 or 1, calcium channel blocker treatment was associated with lower risk (odds ratio [95% confidence interval]=0.60 [0.42-0.86]), and in those with a genetic risk score of 2 to 3, calcium channel blocker treatment was associated with higher risk (odds ratio [95% confidence interval]=1.31 [1.08-1.59]). These results suggest that cardiovascular outcomes may differ based on SIGLEC12, A1BG, F5 genotypes, and antihypertensive treatment strategy. These specific genetic associations and our risk score provide insight into a potential approach to personalized antihypertensive treatment selection.

ABO Blood Groups and Cardiovascular Diseases

ABO blood groups have been associated with various disease phenotypes, particularly cardiovascular diseases. Cardiovascular diseases are the most common causes of death in developed countries and their prevalence rate is rapidly growing in developing countries. There have been substantial historical associations between non-O blood group status and an increase in some cardiovascular disorders. Recent GWASs have identified ABO as a locus for thrombosis, myocardial infarction, and multiple cardiovascular risk biomarkers, refocusing attention on mechanisms and potential for clinical advances. As we highlight in this paper, more recent work is beginning to probe the molecular basis of the disease associations observed in these observational studies. Advances in our understanding of the physiologic importance of various endothelial and platelet-derived circulating glycoproteins are elucidating the mechanisms through which the ABO blood group may determine overall cardiovascular disease risk. The role of blood group antigens in the pathogenesis of various cardiovascular disorders remains a fascinating subject with potential to lead to novel therapeutics and prognostics and to reduce the global burden of cardiovascular diseases.

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.

ABO blood group and risk of coronary heart disease in two prospective cohort studies

OBJECTIVE

Epidemiological data regarding the association between ABO blood groups and risk of coronary heart disease (CHD) have been inconsistent. We sought to investigate the associations between ABO blood group and CHD risk in prospective cohort studies.

METHODS AND RESULTS

Two large, prospective cohort studies (the Nurses' Health Study [NHS] including 62 073 women and the Health Professionals Follow-up Study [HPFS] including 27 428 men) were conducted with more than 20 years of follow-up (26 years in NHS and 24 years in HPFS). A meta-analysis was performed to summarize the associations from the present study and previous studies. In NHS, during 1 567 144 person-years of follow-up, 2055 participants developed CHD; in HPFS, 2015 participants developed CHD during 517 312 person-years of follow-up. ABO blood group was significantly associated with the risk of developing CHD in both women and men (log-rank test; P=0.0048 and 0.0002, respectively). In the combined analysis adjusted for cardiovascular risk factors, compared with participants with blood group O, those with blood groups A, B, or AB were more likely to develop CHD (adjusted hazard ratios [95% CI] for incident CHD were 1.06 [0.99-1.15], 1.15 [1.04-1.26], and 1.23 [1.11-1.36], respectively). Overall, 6.27% of the CHD cases were attributable to inheriting a non-O blood group. Meta-analysis indicated that non-O blood group had higher risk of CHD (relative risk =1.11; 95% CI, 1.05-1.18; P=0.001) compared with O blood group.

CONCLUSIONS

These data suggest that ABO blood group is significantly associated with CHD risk. Compared with other blood groups, those with the blood type O have moderately lower risk of developing CHD.

Common polymorphisms in the P-selectin gene in women with recurrent spontaneous abortions

BACKGROUND

To investigate possible associations of P-selectin polymorphisms with idiopathic recurrent pregnancy loss (RPL).

METHODS

Study subjects comprised 270 consecutive RPL cases attending outpatient maternity services, and 322 multi-parous control women. P-selectin genotyping was done by PCR-RFLP and PCR-ASA methods.

RESULTS

The P-selectin variants rs1800807, rs1800805, and rs6127, were in Hardy Weinberg equilibrium, and low linkage disequilibrium was noted between the three studied SNPs. The frequency of rs6127 A allele (P<0.001I), but not rs1800807 C allele (P=0.957) or rs1800805 A allele (P=0.760), was higher in RPL cases than in control women. Significant differences in the distribution of rs6127 (P<0.001), but not rs1800807 (P=0.444) or rs1800805 (P=0.391) genotypes were seen between cases and controls, and only rs6127 showed a significant association with RPL, with increments of 2.65 and 4.96 in disease risk seen for heterozygous and homozygous carriers, respectively. Among the 8 three-locus Pselectin haplotypes constructed (rs1800807/rs1800805/rs6127), increased frequency of GGG (Pc=0.0249), CGG (Pc=0.0256), and CAG (Pc=0.0174) haplotypes, and lower frequency of CGA haplotype (Pc=0.0091) were seen in RPL cases, thus conferring disease susceptibility and protective nature to these haplotypes, respectively.

CONCLUSIONS

P-selectin gene polymorphisms and haplotypes contribute to RPL development.

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.

Large-scale genomic studies reveal central role of ABO in sP-selectin and sICAM-1 levels

P-selectin and intercellular adhesion molecule-1 (ICAM-1) participate in inflammatory processes by promoting adhesion of leukocytes to vascular wall endothelium. Their soluble levels have been associated with adverse cardiovascular events. To identify loci affecting soluble levels of P-selectin (sP-selectin) and ICAM-1 (sICAM-1), we performed a genome-wide association study in a sample of 4115 (sP-selectin) and 9813 (sICAM-1) individuals of European ancestry as a part of The Cohorts for Heart and Aging Research in Genome Epidemiology consortium. The most significant SNP association for sP-selectin was within the SELP gene (rs6136, P = 4.05 x 10(-61)) and for sICAM-1 levels within the ICAM-1 gene (rs3093030, P = 3.53 x 10(-23)). Both sP-selectin and sICAM-1 were associated with ABO gene variants (rs579459, P = 1.86 x 10(-41) and rs649129, P = 1.22 x 10(-15), respectively) and in both cases the observed associations could be accounted for by the A1 allele of the ABO blood group. The absence of an association between ABO blood group and platelet-bound P-selectin levels in an independent subsample (N = 1088) from the ARIC study, suggests that the ABO blood group may influence cleavage of the P-selectin protein from the cell surface or clearance from the circulation, rather than its production and cellular presentation. These results provide new insights into adhesion molecule biology.

Association of the 98T ELAM-1 polymorphism with increased bleeding after cardiac surgery

OBJECTIVE

Hemorrhage continues to be a major problem after cardiac surgery despite the routine use of antifibrinolytic drugs, with striking inter-patient variability poorly explained by already known risk factors. The authors tested the hypothesis that genetic polymorphisms of inflammatory mediators and cellular adhesion molecules are associated with bleeding after cardiac surgery.

DESIGN

Prospective, observational study.

SETTING

Single, tertiary referral university heart center.

PARTICIPANTS

Adult patients undergoing aortocoronary surgery with cardiopulmonary bypass.

INTERVENTIONS

Patients (n = 759) had 10 mL of blood drawn preoperatively and genomic DNA isolated then genotyped for 17 polymorphisms in 7 candidate genes: tumor necrosis factor, interleukins 1beta and 6, interleukin 1 receptor antagonist, intercellular adhesion molecule-1 (ICAM-1), P-selectin and endothelial leucocyte adhesion molecule-1 (E-selectin). Multivariate analyses were used to relate clinical and genetic factors to bleeding and transfusion.

MEASUREMENTS AND MAIN RESULTS

The 98G/T polymorphism of the E-selectin gene was independently associated with bleeding after cardiac surgery (p = 0.002), after adjusting for significant clinical predictors (patient size and baseline hemoglobin concentration). There was a gene dose effect according to the number of minor alleles in the genotype; carriers of the minor allele bled 17% (GT) and 54% (TT) more than wild type (GG) genotypes, respectively (p = 0.01). Carriers of the minor allele also had longer activated partial thromboplastin times (p = 0.0023) and increased fresh frozen plasma transfusion (p = 0.03) compared with wild type.

CONCLUSIONS

The authors found a dose-related association between the 98T E-selectin polymorphism and bleeding after cardiac surgery, independent of and additive to standard clinical risk factors.

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.

Endothelial activation, inflammation and premature atherosclerosis in children with familial dyslipidemia

OBJECTIVES

Prospective studies demonstrated an increased cardiovascular risk in subjects with high levels of either the endothelial-platelet activation marker P-selectin or high-sensitivity C-reactive protein (hs-CRP). Both children with heterozygous familial hypercholesterolemia (FH) and those with familial combined hyperlipidemia (FCHL) are prone to premature atherosclerosis. Our objective was to investigate in children with either FH or FCHL whether P-selectin and hs-CRP contribute to carotid intima-media thickness (IMT), along with increased plasma lipid levels.

METHODS

Carotid IMT, serum lipids and soluble P-selectin and hs-CRP levels were measured in 88 children (mean age 10.5+/-4.3 years) including 44 dyslipidemic children (25 with FH and 19 with FCHL) and 44 non-dyslipidemic controls.

RESULTS

Carotid IMT was significantly higher among dyslipidemic than in control children (0.46+/-0.06mm vs 0.43+/-0.06mm, p=0.003) and serum P-selectin levels as well [129(50-254)ng/mL vs 50(24.5-130)ng/mL, p<0.001]. FH but not FCHL children had higher hs-CRP levels than controls [0.7(0.01-6.9)mg/L vs 0.3(0.1-1.2)mg/L, p=0.006]. In the entire sample of dyslipidemic children, carotid IMT was positively associated with soluble P-selectin levels (rho=0.30, p=0.049), but not with hs-CRP. The association between P-selectin and carotid IMT was independent from confounders, including plasma lipid levels.

CONCLUSION

Endothelial-platelet activation, more than low-grade systemic inflammation, correlates with premature atherosclerosis among children with familial dyslipidemia, this association being independent from plasma lipid levels.

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.

The relation of genetic and environmental factors to systemic inflammatory biomarker concentrations

BACKGROUND

Environmental and genetic correlates of inflammatory marker variability are incompletely understood. In the family-based Framingham Heart Study, we investigated heritability and candidate gene associations of systemic inflammatory biomarkers.

METHODS AND RESULTS

In offspring participants (n=3710), we examined 11 inflammatory biomarkers (CD40 ligand, C-reactive protein, intercellular adhesion molecule-1, interleukin-6, urinary isoprostanes, monocyte chemoattractant protein-1, myeloperoxidase, P-selectin, tumor necrosis factor-alpha, tumor necrosis factor receptor II, fibrinogen). Heritability and bivariate genetic and environmental correlations were assessed by Sequential Oligogenic Linkage Analysis routines in 1012 family members. We examined 1943 tagging single-nucleotide polymorphisms in 233 inflammatory pathway genes with >or=5 minor allele carriers using a general genetic linear model. Clinical correlates explained 2.4% (CD40 ligand) to 28.5% (C-reactive protein) of the variability in inflammatory biomarkers. Estimated heritability ranged from 10.9% (isoprostanes) to 44.8% (P-selectin). Most correlations between biomarkers were weak although statistically significant. A total of 45 single-nucleotide polymorphism-biomarker associations met the q-value threshold of 0.25. Novel top single-nucleotide polymorphisms were observed in ICAM1 gene in relation to intercellular adhesion molecule-1 concentrations (rs1799969, P=1.32 x 10(-8)) and MPO in relation to myeloperoxidase (rs28730837, P=1.9 x 10(-5)). Lowest P values for trans-acting single-nucleotide polymorphisms were observed for APCS with monocyte chemoattractant protein-1 concentrations (rs1374486, P=1.01 x 10(-7)) and confirmed for IL6R with interleukin-6 concentrations (rs8192284, P=3.36 x 10(-5)). Novel potential candidates (APCS, MPO) need to be replicated.

CONCLUSIONS

Our community-based data support the relevance of clinical and genetic factors for explaining variation in inflammatory biomarker traits.

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.

Cytokines and coronary artery disease: the state of the art

Initiation and progression of coronary atherosclerosis has been associated with inflammation and cytokines balance. The objective of this study is to understand the role of cytokines in the pathophysiology and management of coronary artery disease. Coronary artery disease has been revisited with revision of the pertinent published articles in the Medline, Scopus, and EBSCO Host research from 1987 to 2007. The 2 groups of cytokines (proinflammatory and anti-inflammatory) have been detected in human atherosclerotic plaques. The balance between the 2 groups may reflect the intensity of occult plaque inflammation and the vulnerability to rupture. Multiple studies have determined that a diverse set of proinflammatory biomarkers can furnish prognostic information beyond the traditional risk factors. Inflammatory responses after coronary revascularization are known to play key role in vascular lesion formation early in atherosclerosis and restenosis. Clinical utilization of cytokines remains promising yet incompletely explored and need more studies.

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.

Soluble but not platelet P-selectin correlates with spontaneous platelet aggregation: a pilot study

BACKGROUND

P-selectin (PS) is a marker of platelet activation measured on the platelet surface as platelet PS (pPS) or in serum as soluble PS (sPS). Controversy remains over the exact relationship between sPS, pPS, and other markers such as spontaneous platelet aggregation (SPA).

OBJECTIVE

To investigate correlations between pPS, sPS, and SPA in patients with peripheral arterial disease.

METHODS

SPA, pPS, and sPS levels were measured in venous blood sampled from patients following intermittent claudication (n = 18) or an acute stroke (n = 18).

RESULTS

SPA and sPS correlated significantly in the claudicants (Pearson correlation coefficient, r = 0.661; P = .0020) and stroke patients (r = 0.514; P = .020). No significant correlation was identified between pPS and SPA, or sPS and pPS.

CONCLUSIONS

The 2 methods of assessing PS are not comparable. Although pPS is accepted as a platelet activation marker, sPS may be a better indicator of aggregation represented by SPA.

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.

Plasma levels of P-selectin are determined by platelet turn-over and the P-selectin Thr715Pro polymorphism

BACKGROUND

Plasma levels of soluble P-selectin (sP-selectin) are often used to demonstrate platelet activation.

METHODS

We determined sP-selectin in a variety of disorders characterized by high or low platelet counts and compared their levels with those in healthy subjects. Furthermore, we determined the Thr715Pro polymorphism in all subjects.

RESULTS

Total concentrations of sP-selectin were clearly associated with levels of platelet counts. Thus, calculation of sP-selectin per platelet showed that these levels in patients with thrombocytopenia due to marrow failure and in patients with increased platelet counts were similar to those in controls. Only patients with an increased platelet turn-over had elevated sP-selectin per platelet. While carriers of the Pro715 polymorphism had lower sP-selectin levels than non-carriers, this genetic disposition was over-ruled in patients with increased platelet turn-over.

CONCLUSION

For the demonstration of platelet activation it is preferable to define sP-selectin based on platelet counts under the consideration of the Pro715Thr polymorphism.

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.