CXCL5 polymorphisms are associated with variable blood pressure in cardiovascular disease-free adults.

OBJECTIVE: Leukocyte count has been associated with blood pressure, hypertension, and hypertensive complications. We hypothesized that polymorphisms in the CXCL5 gene, which encodes the neutrophilic chemokine ENA-78, are associated with blood pressure in cardiovascular disease (CVD)-free adults and that these polymorphisms are functional. METHODS AND RESULTS: A total of 192 community-dwelling participants without CVD or risk equivalents were enrolled. Two CXCL5 polymorphisms (-156 G > C (rs352046) and 398 G > A (rs425535)) were tested for associations with blood pressure. Allele-specific mRNA expression in leukocytes was also measured to determine whether heterozygosity was associated with allelic expression imbalance. In -156 C variant carriers, systolic blood pressure (SBP) was 7 mmHg higher than in -156 G/G wild-type homozygotes (131 ± 17 vs. 124 ± 14 mmHg; P = 0.008). Similarly, diastolic blood pressure (DBP) was 4 mmHg higher in -156 C variant carriers (78 ± 11 vs. 74 ± 11 mmHg; P = 0.013). In multivariate analysis of SBP, age, sex, body mass index, and the -156 G > C polymorphism were identified as significant variables. Age, sex, and the -156 G > C SNP were further associated with DBP, along with white blood cells. Allelic expression imbalance and significantly higher circulating ENA-78 concentrations were noted for variant carriers. CONCLUSION: CXCL5 gene polymorphisms are functional and associated with variable blood pressure in CVD-free individuals. The role of CXCL5 as a hypertension- and CVD-susceptibility gene should be further explored.

Development and cross-validation of sequencing-based assays for genotyping common polymorphisms of the CXCL5 gene.

BACKGROUND: Epithelial neutrophil activating peptide (ENA-78) is encoded by the polymorphic CXCL5 gene and is a recruiter and activator of neutrophils. Furthermore, ENA-78 may be involved in pathological inflammatory processes and variable drug responses. METHODS: To facilitate future disease-gene and pharmacogenetic investigation of ENA-78, we developed and cross-validated medium- to high-throughput genotyping assays for 2 commonly occurring CXCL5 polymorphisms (rs352046 and rs425535). Furthermore, we compared allele and genotype frequencies in a U.S. population with those of a previously studied European population. RESULTS: There was 100% genotype concordance between the 2 methods used (Pyrosequencing and TaqMan). Variant allele frequencies for rs352046 were consistent between the U.S. (16%) and European (16%) populations, while the rs425535 variant allele was more than twice as high in the European cohort (38% vs. 16%). There was complete linkage of genotypes at both loci in our population. CONCLUSIONS: The distribution of variant alleles for the 2 polymorphisms studied should be further evaluated in other populations. In addition, our data highlight the importance of assay validation using multiple platforms.

Complementary and alternative medicine use among individuals participating in research: implications for research and practice.

STUDY OBJECTIVES: To determine the frequency and type of complementary and alternative medicine (CAM) use among healthy volunteers participating in research, and to investigate the potential for interactions between commonly used CAM modalities and various drugs. DESIGN: Prospective evaluation. SETTING: University general clinical research center. SUBJECTS: Sixty healthy adults participating in an ongoing drug study. MEASUREMENTS AND MAIN RESULTS: The clinical study database was queried to determine the use and type of existing and newly started CAM throughout the study period. Baseline characteristics were compared between users and nonusers of CAM to identify differences between them. Potential CAM-drug interactions were classified based on curated databases and primary literature sources. Of the 60 subjects enrolled, 30 (50%) used CAM during the study. Of these, 26 (87%) were using CAM at study entry. Baseline CAM users were on average 7 years older than nonusers (p=0.03) and had high-density lipoprotein cholesterol concentrations 10 mg/dl higher than those of nonusers (p=0.04). The group using CAM had more women and nonsmokers than the other group. Several potential CAM-drug interactions were identified. CONCLUSION: Because of high rates of CAM use (50% of the subjects were using biologically based CAM) and the many potential CAM-drug interactions, CAM use should be rigorously addressed in clinical practice and research. Failure to capture this information may have clinical repercussions through pharmacokinetic and pharmacodynamic interference of clinical response and clinical trial results. Clinicians and researchers may be able to identify those most likely to use CAM by their baseline characteristics; this would help target those patients and research subjects for more thorough assessment and follow-up.

Atorvastatin effect on circulating and leukocyte-produced CD40 ligand concentrations in people with normal cholesterol levels: a pilot study.

STUDY OBJECTIVES: To investigate whether atorvastatin decreases serum or leukocyte-produced CD40 ligand (CD40L) levels and whether these effects are dependent on reduction in low-density lipoprotein cholesterol (LDL) levels in people without overt dyslipidemia. DESIGN: Prospective pilot study. SETTING: University research center. SUBJECTS: Twenty-five normocholesterolemic volunteers (mean age 32 +/- 11 yrs; 15 women, 10 men) without cardiovascular disease. INTERVENTION: After a 2-week drug-free run-in period, subjects received atorvastatin 80 mg/day orally for 16 weeks. MEASUREMENTS AND MAIN RESULTS: All lipoprotein level measurements were performed with the subject in the fasting state. The CD40L concentrations were measured by immunofluorescence detection in serum and leukocyte culture supernates after 24-hour incubation, and treatment effect was analyzed. Baseline mean +/- SD total cholesterol, LDL, high-density lipoprotein cholesterol, and triglyceride levels were 179 +/- 33, 97 +/- 29, 62 +/- 20, and 102 +/- 69 mg/dl, respectively. Mean changes in each of these levels, respectively, after 16 weeks of atorvastatin were -34%, -59%, +3%, and -23%. The median serum CD40L level was lower at 16 weeks (2.3 ng/ml, interquartile range [IQR] 1.2-5.0 ng/ml) than at baseline (3.0 ng/ml, IQR 2.1-3.7 ng/ml), but the change was not significant (p=0.24). However, atorvastatin significantly lowered CD40L produced from leukocytes by 57% (21 pg/mg of protein [IQR 10-38 pg/mg] vs 49 pg/mg [IQR 21-149 pg/mg], p=0.045). Effects were independent of reduction in cholesterol levels. CONCLUSION: Although atorvastatin did not significantly lower serum CD40L levels, significant reduction in leukocyte production was seen independent of degree of LDL reduction. These pilot data suggest a potential benefit in normocholesterolemic individuals that should be further investigated, and that leukocyte CD40L concentrations should be considered in the drug response.

Modulatory effects of atorvastatin on endothelial cell-derived chemokines, cytokines, and angiogenic factors.

STUDY OBJECTIVE: To investigate the immunomodulatory effects of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) by determining whether atorvastatin alters the production of specific endothelium-derived immunoactive proteins and whether its treatment effects depend on its concentration and/or inhibition of 3-hydroxy-3-methylglutaryl coenzyme A reductase. DESIGN: In vitro study using a multiplexing method for protein measurement. SETTING: University laboratory. MEASUREMENTS AND MAIN RESULTS: Human umbilical vein endothelial cells were cultured to approximately 80% confluence and treated with atorvastatin 1-50 microM alone or with mevalonate for 24 hours. Untreated cells served as controls. Culture-conditioned media were removed and multiplex assayed for protein content of epithelial neutrophil-activating peptide-78, interleukin-8, monocyte chemotactic protein-1, interleukin-6, interleukin-10, fibroblast growth factor, and granulocyte colony stimulating factor. Atorvastatin significantly reduced the production of epithelial neutrophil-activating peptide-78, interleukin-6, interleukin-8, and monocyte chemotactic protein-1 (p<0.001 to p<0.05) in a concentration-dependent manner without affecting basal production of interleukin-10, fibroblast growth factor, and granulocyte colony stimulating factor. The treatment effects of atorvastatin were reversed with concurrent mevalonate therapy. CONCLUSION: By inhibiting 3-hydroxy-3-methylglutaryl coenzyme A reductase, atorvastatin lowered concentrations of several inflammatory molecules derived from basal-state endothelial cells in a concentration-dependent manner. The in vivo importance of these immunomodulatory effects needs further investigation.

Epithelial neutrophil-activating peptide (ENA-78), acute coronary syndrome prognosis, and modulatory effect of statins.

Endothelial inflammation with chemokine involvement contributes to acute coronary syndromes (ACS). We tested the hypothesis that variation in the chemokine gene CXCL5, which encodes epithelial neutrophil-activating peptide (ENA-78), is associated with ACS prognosis. We also investigated whether statin use, a potent modulator of inflammation, modifies CXCL5's association with outcomes and characterized the in vitro effect of atorvastatin on endothelial ENA-78 production. Using a prospective cohort of ACS patients (n = 704) the association of the CXCL5 -156 G>C polymorphism (rs352046) with 3-year all-cause mortality was estimated with hazard ratios (HR). Models were stratified by genotype and race. To characterize the influence of statins on this association, a statin*genotype interaction was tested. To validate ENA-78 as a statin target in inflammation typical of ACS, endothelial cells (HUVECs) were treated with IL-1beta and atorvastatin with subsequent quantification of CXCL5 expression and ENA-78 protein concentrations. C/C genotype was associated with a 2.7-fold increase in 3-year all-cause mortality compared to G/G+G/C (95%CI 1.19-5.87; p = 0.017). Statins significantly reduced mortality in G/G individuals only (58% relative risk reduction; p = 0.0009). In HUVECs, atorvastatin dose-dependently decreased IL-1beta-stimulated ENA-78 concentrations (p<0.0001). Drug effects persisted over 48 hours (p<0.01). CXCL5 genotype is associated with outcomes after ACS with potential statin modification of this effect. Atorvastatin lowered endothelial ENA-78 production during inflammation typical of ACS. These findings implicate CXCL5/ENA-78 in ACS and the statin response.

Evaluation of hawthorn extract on immunomodulatory biomarkers in a pressure overload model of heart failure.

BACKGROUND: Hawthorn extract (Crataegeus sp.) a botanical complementary and alternative medicine is often used to treat heart failure. The mechanism(s) by which hawthorn extract may treat heart failure is unknown but may include, theoretically, immunological effects. Therefore, the purpose of this study is to determine the effect of hawthorn extract on the immunomodulatory response in a pressure overload model of heart failure. MATERIAL/METHODS: A total of 62 male Sprague-Dawley rats were randomized to either aortic constriction + vehicle (AC; n=15), aortic constriction + hawthorn 1.3 mg/kg (HL, n=17), aortic constriction + hawthorn 13 mg/kg (HM, n=15), or aortic constriction + hawthorn 130 mg/kg (HH, n=15). Six months after surgical procedure animals were sacrificed and plasma samples obtained for the measurement of the following immunomodulatory markers: interleukin (IL) IL-1ss, IL-2, IL-6, IL-10; and leptin. RESULTS: The mortality rate following 6 months of aortic constriction was 40% in the AC group compared to 41%, 60%, and 53% for the HL, HM, and HH groups respectively (P>0.05 compared to AC). Aortic constriction produced a similar increase in the left ventricle/body weight ratio for all groups. Hawthorn extract had no effect on the immunomodulatory markers measured in this study, although there appeared to be a trend suggesting suppression of IL-2 plasma concentrations. CONCLUSIONS: In this animal model of heart failure, hawthorn extract failed to significantly affect the immunomodulatory response characterized after 6 months of pressure overload at a time when approximately 50% mortality was exhibited. Mechanisms other than immunological may better define hawthorn's effect in treating heart failure.