Effect of LSR polymorphism on blood lipid levels and age-specific epistatic interaction with the APOE common polymorphism

The lipolysis stimulated lipoprotein receptor (LSR) is an apolipoprotein (Apo) B and ApoE receptor that participates in the removal of triglyceride-rich lipoproteins during the postprandial phase. LSR gene is located upstream of APOE, an important risk factor for cardiovascular disease (CVD). Since the APOE common polymorphism significantly affects the variability of lipid metabolism, this study aimed to determine the potential impact of a functional SNP rs916147 in LSR gene on lipid traits in healthy subjects and to investigate potential epistatic interaction between LSR and APOE. Unrelated healthy adults (N = 432) and children (N = 328, <18 years old) from the STANISLAS Family Study were used. Age-specific epistasis was observed between APOE and LSR, reversing the protective effect of APOE ε2 allele on cholesterol, ApoE and low-density lipoprotein levels (β: .114, P: .777 × 10^-8 , β: .125, P: .639 × 10^-3 , β: .059, P: .531 × 10^-3 , respectively). This interaction was verified in an independent adult population (n = 1744). These results highlight the importance of the LSR polymorphism and reveal the existence of complex molecular links between LSR and ApoE for the regulation of lipid levels, revealing potential new pathways of interest in type III hyperlipidemia and its involvement in CVD pathology.

The Role of Genetics in Defining Reference Values and Health Status

Since its establishment, the Center for Preventive Medicine in Vandoeuvre-les-Nancy, France, performed specific studies on healthy humans, and its approach was very useful for defining reference values. Prevention should extend its interest to chronic diseases. The majority of important adult disorders are partially genetically determined. Genetic markers are also useful as exclusion or as partition criteria in the production of reference values. Results are presented that were obtained for apolipoproteins E, B and AIV, frequencies of these polymorphisms in the Lorraine population, and relationships between these polymorphisms and lipid metabolism-related parameters. Health checkup centers, in particular those involved in family screening, are well suited for reassembling many data concerning environmental factors: tobacco consumption, alimentation habits, or alcohol and drug consumption. Simultaneous determination of genetic markers could allow the determination of an individual’s susceptibility or resistance to developing a disease and to prepare a preventive action.

Progress in pharmacogenetics: consortiums and new strategies

Pharmacogenetics (PGx), as a field dedicated to achieving the goal of personalized medicine (PM), is devoted to the study of genes involved in inter-individual response to drugs. Due to its nature, PGx requires access to large samples; therefore, in order to progress, the formation of collaborative consortia seems to be crucial. Some examples of this collective effort are the European Society of Pharmacogenomics and personalized Therapy and the Ibero-American network of Pharmacogenetics. As an emerging field, one of the major challenges that PGx faces is translating their discoveries from research bench to bedside. The development of genomic high-throughput technologies is generating a revolution and offers the possibility of producing vast amounts of genome-wide single nucleotide polymorphisms for each patient. Moreover, there is a need of identifying and replicating associations of new biomarkers, and, in addition, a greater effort must be invested in developing regulatory organizations to accomplish a correct standardization. In this review, we outline the current progress in PGx using examples to highlight both the importance of polymorphisms and the research strategies for their detection. These concepts need to be applied together with a proper dissemination of knowledge to improve clinician and patient understanding, in a multidisciplinary team-based approach.

Systems medicine, personalized health and therapy

The 7th Santorini Conference was held in Santorini, Greece, and brought together 200 participants from 40 countries in several continents, including Europe, USA but also Japan, Korea, Brazil and South Africa. The attendees had the opportunity to: listen to 60 oral presentations; participate in two lunch symposia; look at 103 posters, which were divided in two groups ('systems medicine and environment' and 'pharmacogenomics and cancer') and attend a dedicated exhibition with six companies. The meeting was organized by the Institut National de la Santé et de la Recherche Médicale (INSERM) U1122; IGE-PCV and by 'Biologie Prospective' with the collaboration of the European Society of Pharmacogenomics and Theranostics (ESPT), under the auspices of international organizations (e.g., International Federation of Clinical Chemistry and Laboratory medicine [IFCC], European Federation of Clinical Chemistry and Laboratory Medicine [EFLM], European Diagnostic Manufacturers Association [EDMA], Federation of European Pharmacological Societies [EPHAR], European Science Foundation [ESF]). The 3 days of the conference stimulated intensive discussions on systems biology and the influence of omics technologies on personalized health. Sixty speakers were invited or selected from early abstracts and gave presentations on the following topics: From systems biology to systems medicine/pharmacology; Omics/translating pharmacogenomics/proteomic biomarkers/metabolomics; Human nutrition and health/personalized medicine. We are summarizing here the main topics and presentations, according to the successive sessions.

Genetic determined low response to thienopyridines is associated with higher systemic inflammation in smokers

AIM

To investigate whether the interactions of CYP2C19*2 and CYP2C19*17 with smoking are associated with the levels of P2Y12 receptor inhibition and CRP, in on-thienopyridine post-stenting patients.

METHODS & RESULTS

At 1-month follow-up, the interactions of smoking and CYP2C19 polymorphisms on the vasodilator-stimulated phosphoprotein - platelet reactivity index (VASP PRI), and CRP were explored in three metabolizing groups (1128 patients) as follow: poor metabolizers (*2 carriers/*17 noncarriers); intermediate metabolizers (*2 carriers/*17 carriers or *2 noncarriers/*17 noncarriers); and ultrarapidmetabolizers (*2 allele noncarriers/*17 carriers). The interactions of metabolizing status and smoking was significant for CRP (p = 0.001) but not for VASP PRI (p = 0.734).

CONCLUSION

Interaction between CYP2C19 polymorphisms and smoking modifies on-treatment CRP level of post-stenting, on-thienopyridine patients. This effect seems to be independent to the level of P2Y12 receptor inhibition.

Conference scene: pharmacogenomics: from cell to clinic (part 2)

Second International ESPT Meeting Lisbon, Portugal, 26-28 September 2013 The second European Society of Pharmacogenomics and Theranostics (ESPT) conference was organized in Lisbon, Portugal, and attracted 250 participants from 37 different countries. The participants could listen to 50 oral presentations, participate in five lunch symposia and were able to view 83 posters and an exhibition. Part 1 of this Conference Scene was presented in the previous issue of Pharmacogenomics. This second part will focus on: clinical implementation of pharmacogenomics tests; transporters and pharmacogenomics; stem cells and other new tools for pharmacogenomics and drug discovery; from system pharmacogenomics to personalized medicine; and, finally, we will discuss the Posters and Awards that were presented at the conference.

Pharmacogenomics: from cell to clinic (Part 1)

The second international European Society of Pharmacogenomics and Theranostics (ESPT) conference was organized in Lisbon, Portugal, and attracted 250 participants from 37 different countries. The participants could listen to 50 oral presentations, participate in five lunch symposia and were able to view 83 posters and an exhibition. The first part of this Conference Scene will focus on the pharmacogenomics and biomarkers used in medical oncology, and in particular solid tumors. In addition, this article covers the two keynote conference introductory lectures by Ann K Daly and Magnus Ingelman-Sundberg. The second part of this article will discuss the clinical implementation of pharmacogenomic tests; the role of transports and pharmacogenomics; how stem cells and other new tools are helping the development of pharmacogenomics and drug discovery; and an update on the clinical translation of pharmacogenomics to personalized medicine. Part two of this Conference Scene will be featured in the next issue of Pharmacogenomics.

Conference Scene: Systems biology and personalized health science and translation

After a 1-day advanced course on systems biology, the main themes of this 3-day colloquium were developed: from systems biology to systems medicine with special applications to cancer; pharmacogenomics in drug discovery and clinical application; and epigenomics and genome-wide association studies in cardiovascular diseases. In two roundtable discussions on pharmacogenomics and genome-wide association studies, the progress and the difficulties in the implementation of omics technologies in clinical practice were discussed. Three workshops were also organized on technical tools linked to the meeting themes.

Influence of genetic variations on levels of inflammatory markers of healthy subjects at baseline and one week after clopidogrel therapy; results of a preliminary study

We aimed to assess the association between the most common polymorphisms of cytochrome P450 (CYP) epoxygenases on the plasma levels of inflammatory markers in a population of healthy subjects. We also sought to determine whether CYP2C19*2 polymorphism is associated with the anti-inflammatory response to clopidogrel. In a population of 49 healthy young males, the baseline plasma levels of inflammatory markers including C-reactive protein, haptoglobin, orosomucoid acid, CD-40 were compared in carriers vs. non-carriers of the most frequent CYP epoxygenase polymorphisms: CYP2C9*2, CYP2C9*3, CYP2C19*2, CYP2C8*2 and CYP2J2*7. Also, the variation of inflammatory markers from baseline to 7 days after administration of 75 mg per day of clopidogrel were compared in carriers vs. non-carriers of CYP2C19* allele and also in responders vs. hypo-responders to clopidogrel, determined by platelet reactivity tests. There was no significant association between epoxygenase polymorphisms and the baseline levels of inflammatory markers. Likewise, CYP2C19* allele was not associated with anti-inflammatory response to clopidogrel. Our findings did not support the notion that the genetic variations of CYP epoxygenases are associated with the level of inflammatory markers. Moreover, our results did not support the hypothesis that CYP2C19*2 polymorphism is associated with the variability in response to the anti-inflammatory properties of clopidogrel.

Epistatic study reveals two genetic interactions in blood pressure regulation

Background

Although numerous candidate gene and genome-wide association studies have been performed on blood pressure, a small number of regulating genetic variants having a limited effect have been identified. This phenomenon can partially be explained by possible gene-gene/epistasis interactions that were little investigated so far.

Methods

We performed a pre-planned two-phase investigation: in phase 1, one hundred single nucleotide polymorphisms (SNPs) in 65 candidate genes were genotyped in 1,912 French unrelated adults in order to study their two-locus combined effects on blood pressure (BP) levels. In phase 2, the significant epistatic interactions observed in phase 1 were tested in an independent population gathering 1,755 unrelated European adults.

Results

Among the 9 genetic variants significantly associated with systolic and diastolic BP in phase 1, some may act through altering the corresponding protein levels: SNPs rs5742910 (P_adjusted≤0.03) and rs6046 (P_adjusted =0.044) in F7 and rs1800469 (P_adjusted ≤0.036) in TGFB1; whereas some may be functional through altering the corresponding protein structure: rs1800590 (P_adjusted =0.028, SE=0.088) in LPL and rs2228570 (P_adjusted ≤9.48×10^-4) in VDR. The two epistatic interactions found for systolic and diastolic BP in the discovery phase: VCAM1 (rs1041163) * APOB (rs1367117), and SCGB1A1 (rs3741240) * LPL (rs1800590), were tested in the replication population and we observed significant interactions on DBP. In silico analyses yielded putative functional properties of the SNPs involved in these epistatic interactions trough the alteration of corresponding protein structures.

Conclusions

These findings support the hypothesis that different pathways and then different genes may act synergistically in order to modify BP. This could highlight novel pathophysiologic mechanisms underlying hypertension.

Dairy product consumption, calcium intakes, and metabolic syndrome-related factors over 5 years in the STANISLAS study

OBJECTIVE

We assessed the associations of total dairy products; milk, yogurt, and cottage cheese; cheese; and calcium with 5-y changes in components of the metabolic syndrome.

METHODS

Two hundred eighty-eight men and 300 women 28 to 60 y of age from the suivi temporaire annuel non invasif de la santé des lorrains assurés sociaux (STANISLAS) cohort completed at baseline a 3-d dietary record. Statistics were performed using multivariate regression analysis.

RESULTS

In men, no relation was found between the four dietary indices and components of the metabolic syndrome measured at baseline. Conversely, the consumption of milk, yogurt, and cottage cheese at entry was inversely associated with 5-y changes in glucose levels (P ≤ 0.05, P ≤ 0.01 for sex interaction) and positively with 5-y changes in high-density lipoprotein cholesterol (P ≤ 0.05). Higher calcium intakes were significantly related to a lower 5-y increase of the body mass index (BMI) and waist circumference in men (P ≤ 0.01, P ≤ 0.05 for sex interaction). In addition, changes in diastolic blood pressure were inversely associated with the consumption of milk, yogurt, and cottage cheese only in men with a normal BMI (P ≤ 0.05 for BMI interaction). In women, unlike men, associations were shown for some components measured at baseline: total dairy positively related to BMI and waist circumference; total dairy, milk, yogurt, and cottage cheese, and calcium were positively related to triacylglycerols and negatively to high-density lipoprotein cholesterol. However, no significant association was found for any 5-y-changes.

CONCLUSION

In men only, a higher consumption of dairy products was associated with positive changes in the metabolic profile in a 5-y period; a higher calcium consumption was associated with a lower 5-y increase of the BMI and waist circumference.

Availability of pharmacogenetic and pharmacogenomic information in anticancer drug monographs in France: personalized cancer therapy

Aim: To determine the availability of pharmacogenetic and pharmacogenomic information for healthcare professionals in France during 2009 for anticancer drugs. Materials & methods: We searched in the informatic version of the VIDAL dictionary which is currently used by healthcare professionals in France. We then compared this with data available in the PubMed database. Results: Among the 109 anticancer molecules available in France during 2009, 13 have pharmacogenomic or pharmacogenetic information in their monographs. In the scientific literature, we found numerous pharmacogenomic and pharmacogenetic biomarkers concerning 43 of the 109 anticancer agents. Some are pharmacogenomic biomarkers related to drug effectiveness, others are pharmacogenetic biomarkers related to drug toxicity. Conclusion: We believe that the lack of pharmacogenomic and pharmacogenetic information in drug monographs reflects the relative newness of the discipline. However, pharmacogenetics and pharmacogenomics can offer valuable information for improving the safety of drugs, reducing toxicity and predicting nonresponders. The drugs might then be incorporated into clinical practice through several strategies, including increased drug labeling and better education of healthcare professionals.

Functional genomics towards personalized healthcare and systems medicine

The 5th Biologie Prospective Santorini Conference explored the themes of systems biology, nutrigenomics and pharmacogenomics, all of which are related to personalized health, personalized therapy and personalized medicine. The conference started with a satellite meeting on genome-wide scan studies where the need for simplified models, the quality of the phenotypes and the input of epigenetics were dominant remarks. All of the omics approaches were then applied during the 3 days' sessions to multifactorial diseases (e.g., diabetes, atherosclerosis, cancer and inflammation) and often focused on gene-gene and gene-environment interactions. Afterwards, a fundamental session on drug metabolism, theranostics and pharmacogenetics and their practical aspects showed that the translation to clinical practice is finally happening although much slower than expected.

Hydroxylation of Debrisoquine Using Perfused Liver Isolated from Sprague Dawley and DA Rats: Comparison With In-vivo Results

The hydroxylation of debrisoquine was investigated in Sprague-Dawley (SD) and Dark-Agouti (DA) rats. Female and male rats were phenotyped in-vivo with debrisoquine six times during their growth. The ratios debrisoquine/4-hydroxydebrisoquine of the female DA rats increased until the 15th week and then decreased; but the values of the metabolic ratios never exceeded 2. Female DA rats cannot be considered as genetically deficient for hydroxylation of debrisoquine in regard to the metabolic ratio, but the percentage of debrisoquine excretion is up to ten fold higher than that in the other strains. Therefore SD and DA rat livers were perfused for 2 h when the clearance of debrisoquine was significantly lower in the female DA group than in the other groups. 4-Hydroxydebrisoquine in the perfusate increased with time, but the amount after 120 min was 12 fold lower in the female DA rat group than in the female SD rat group. The results of the male DA group fell between. This study confirms that female DA rats present a lower debrisoquine 4-hydroxylating capacity than other rats but shows that urinary metabolic ratio is not sufficient to assess the deficiency of debrisoquine hydroxylation.

Sex-dependent associations of leptin with metabolic syndrome-related variables: the Stanislas study

Serum leptin has been reported to be associated in a sex-dependent manner with C-reactive protein (CRP), independently of adiposity. We tested the hypothesis that leptin is associated, independently of anthropometry indexes and in a sex-dependent way, with other inflammatory markers and variables related to metabolic syndrome (MS). In 384 healthy middle-aged adults (192 men and 192 women) total fat mass (FM), waist circumference (WC), serum leptin and 15 MS-related parameters (systolic and diastolic blood pressure, triglycerides, cholesterol, high density lipoprotein (HDL)-cholesterol, apo AI and B, fasting glucose, uric acid, CRP, orosomucoid and haptoglobin levels and aspartate aminotransferase (ASAT), alanine aminotransferase (ALAT) and gamma-glutamyl transferase (GGT) activities) were measured. After adjustment for age, alcohol and cigarette consumption, WC, and total FM, leptin concentration was significantly associated with serum triglycerides, total cholesterol, apo B, uric acid and haptoglobin concentrations and liver enzyme activity only in men, and with apo AI, HDL-cholesterol (only borderline) and CRP only in women. Sex interaction terms were significant for total cholesterol, apo B, HDL cholesterol, uric acid, ALAT and GGT, and borderline significant for triglycerides, apo AI and ASAT. In this healthy population, leptin is significantly associated with various MS factors, independently of WC and total FM, depending on gender. Our study provides further evidence of sex-related differences mediated by leptin in inflammatory mechanisms and other MS-related metabolic pathways.

Association of human cathelicidin (hCAP-18/LL-37) gene expression with cardiovascular disease risk factors

BACKGROUND AND AIMS

Antimicrobial peptides (AMPs) are components of the innate immune system. In addition, evidence suggests that these peptides are associated with various inflammatory diseases. We examined whether expression of the cathelicidin LL-37 in peripheral blood mononuclear cells (PBMCs) is associated with cardiovascular risk factors.

METHODS AND RESULTS

A total of 90 men and 87 women selected from STANISLAS cohort were studied. Expression of LL-37 mRNA isolated from PBMCs of these subjects was quantified by quantitative RT-PCR. Anthropometric measurements and biochemical profiles were assessed for each individual. In women, LL-37 mRNA expression was significantly and positively correlated with body mass index (BMI) (p<or=0.001); waist circumference (WC) (p<or=0.01); systolic blood pressure (SBP) (p<or=0.05) and triglycerides (TG) level (p<or=0.05) and negatively with plasma levels of HDL-C (p<or=0.05). In men however, LL-37 was positively associated with waist to hip ratio (WHR) (p<or=0.05); SBP (p<or=0.001); TG (p<or=0.05); fasting glucose levels (p<or=0.01); alanine aminotransferase (ALT) activity (p<or=0.01); neutrophils counts (p<or=0.01) and negatively with lymphocyte counts (p<or=0.001); serum HDL-C (p<or=0.001) and apoA-I (p<or=0.05) levels. After adjustment for WC and BMI, multiple regression analysis showed that LL-37 remained significantly associated with SBP; HDL-C; fasting glucose level; ALT activity; neutrophil and lymphocyte counts (p<or=0.001 to p<or=0.05) in men.

CONCLUSION

Our results suggest that LL-37 gene expression may be closely associated with cardiovascular risk factors independently of BMI and WC. However, functional studies are required to confirm these data.

Human formyl peptide receptor 1 (FPR1) c.32C>T SNP is associated with decreased soluble E-selectin levels

Aims: The human formyl peptide receptor (FPR) is a G protein-coupled chemoattractant receptor that is thought to mediate inflammatory responses. The FPR1 gene is highly polymorphic. In a recent study, the FPR1 c.32C>T SNP, resulting in the amino-acid substitution I11T, was reported to be significantly associated with C-reactive protein levels. Therefore, this study sought to determine if the impact of such a genetic variation extends to other clinical parameters associated with inflammation, including cytokines, adhesion molecules and inflammatory markers. Materials & methods: This study was carried out on a subsample of 325 adults selected from the STANISLAS cohort study. The FPR1 c.32C>T SNP was genotyped using PCR amplification followed by restriction enzyme digestion. Anthropometric measurements and biochemical profiles were assessed for each individual. Results: The allele frequencies of FPR1 c.32C>T were 0.74 for the 32C allele and 0.26 for the 32T allele. Genotype frequencies were 0.55 for C/C, 0.38 for C/T and 0.07 for T/T. After adjusting for age, sex, BMI, alcohol and cigarette consumption, oral contraceptive, antibiotics and anti-inflammatory drug use, statistical analysis (under a recessive model of inheritance) demonstrated that serum E-selectin levels were 68% lower in individuals homozygous for T/T than in those with C/T or C/C genotypes (p = 0.001). However, no significant correlations were found for C-reactive protein or the other 18 tested clinical parameters that were analyzed in this study. Conclusion: The FPR1 c.32C>T SNP may be associated with E-selectin levels in the French population. Although of importance, these findings need confirmation in larger studies.

Parental precocious influences on offspring cardiovascular risk markers: an exploratory study in the STANISLAS Cohort

Familial history of cardiovascular disease is acknowledged as a risk indicator in offspring. The aim of this study was to assess whether the cardiovascular risk factors in parents predicted the risk of their children developing cardiovascular disease in a French population: the STANISLAS Cohort, in which Caucasian biparental families with at least two siblings were followed for 5 years. Silent risk factors (blood pressure, lipid traits, glycemia, BMI and waist circumference) of children were compared according to their parents' risk status in a subsample of 693 families. All of these traits, with the exception of glucose, were significantly higher in children who had parents at a high risk than in children with parents at a low risk at the first health examination, and these results were confirmed again 5 years later at the second health examination. Thus, silent cardio-metabolic risk factors can be screened in children according to the risk status of their parents for early prevention. The influence of parents' variants on their offspring underlined the need to initiate familial prevention strategies, with a particular follow-up of young individuals between childhood and adolescence.

Association of ABCB1 gene polymorphisms with plasma lipid and apolipoprotein concentrations in the STANISLAS cohort

BACKGROUND

While involvement of ABCB1 is well known in drug transport, its metabolite transport role is not so well understood. Like other ABC transporters, ABCB1 might be implicated in cholesterol homeostasis and ABCB1 polymorphisms which are responsible for drug resistance might affect lipid homeostasis. Our objective was thus to investigate the implication of ABCB1 polymorphisms and haplotypes in the genetic variability of lipid constituents in healthy people.

METHODS

T-129C, G-1A, A61G, G1199A, C1236T, T-76A, G2677T/A and C3435T polymorphisms were genotyped in 371 supposed healthy individuals from the STANISLAS cohort. Each polymorphism was tested with plasma concentrations of total cholesterol, HDL and LDL cholesterol, triglycerides and apolipoproteins A1, B, C3 and E.

RESULTS

After adjustment for covariates, carriers of at least one 3435T allele had a significant higher level of apolipoprotein A1 (p = 0.005). In addition, significant correlations were observed in a sex-dependent manner. Women carrying either T-76 or 1236T allele (tendency with G-1 and 2677T/A) had lower total cholesterol (p < or = 0.01) and apolipoprotein B (T-76 exclusively, p=0.002). Haplotypes analysis was not more informative than the single polymorphisms except G2677T/A-C3435T haplotypes for apolipoprotein A1 concentration.

CONCLUSION

ABCB1 polymorphisms contribute to the genetic variability of plasma values of lipids and lipoproteins in healthy people.

The STANISLAS Cohort: a 10-year follow-up of supposed healthy families. Gene-environment interactions, reference values and evaluation of biomarkers in prevention of cardiovascular diseases

The description of this familial longitudinal cohort was published in this journal 10 years ago, in 1998. To date, 117 publications on the STANISLAS Cohort (SC) have appeared, corresponding to five main categories of results: familial resemblance and heritability; genetics and gene-environment interactions; mRNA and proteins as gene products; reference values and biological variations of proteins; and finally preventive medicine and prepathological epidemiological data. More than 600 data values on demographic and laboratory data have been collected on each individual taking part out of the 1006 families at the beginning and for all three recruitments. Serum and plasma are stored in liquid nitrogen for all participants for all three recruitments. DNA has been extracted from all participants and mRNA from 357 families. They are stored at -80 degrees C. Owing to the SC study, heritability and many gene-environment interactions have been described. The expression of 166 genes related to cardiovascular diseases was measured in peripheral blood mononuclear cells RNA. Reference values for proteins and vitamins have been established in addition to reference values for the carotid and femoral intima media thickness in adults and children. The data obtained contribute to a better understanding of the relation between the studied polymorphisms (161 polymorphic sites) and health, and predisposition to obesity, high blood pressure and metabolic syndrome. To the best of our knowledge, the SC study is internationally the only longitudinal family cohort of subjects who are presumed to be healthy, which enables the study of the chain DNA-RNA-proteins.

Drug effects on clinical laboratory tests

Drugs and xenobiotics can affect clinical laboratory test results either by interfering with the analytical systems themselves, or by influencing endogenous constituents. National and international bodies have brought widespread recognition to this problem and have proposed protocols for its thorough scientific study. In this survey the authors discuss studies in their laboratories concerning the effects of drugs on thousands of patients undergoing a routine clinical screen. A database is described for storing both patient information and a detailed analysis of the published literature on drug effects. Analytical interferences in clinical tests must be examined in validating the procedure. However, highly specific analytical techniques are increasingly helping to reduce such interferences. Biological effects can be classified as physiological, pharmacological or toxicological. In some cases, biological effects can be used to advantage in monitoring treatment by potentially hazardous drugs, such as the cardiac glycosides. The requirement for a well-defined reference population for each drug and for access to all clinical and medical data for each patient is discussed. The need for greater awareness of the influence of drugs on clinical laboratory results is considered, together with the suggestion that the health professions should try to exploit such effects in monitoring possible toxicity problems, in defining genetic constitution and in designing medication programmes.

Genetic Polymorphism of CYP2C19 gene in the Stanislas cohort. A link with inflammation

CYP2C19, a member of the cytochrome P450 family, metabolises arachidonic acid to produce epoxyeicosanoid acids, which are involved in vascular tone and inflammation. Thus, this study describes the possible relationship between a CYP2C19 polymorphism (681G>A) and three inflammatory markers: interleukin (IL)-6, tumor necrosis factor-alpha (TNF-alpha) and high sensitivity C-reactive protein (hs-CRP) in healthy individuals. In a sub-sample of 178 men and 181 women from the Stanislas study, we quantified plasma IL-6 and TNF-alpha concentrations by using an enzyme-linked immunosorbent assay, and serum hs-CRP concentration by immunonephelometry. The CYP2C19 681G>A polymorphism was genotyped using the kinetic thermocycling allele specific PCR method. In the Stanislas cohort, the frequency of the allele CYP2C19*2 (681A) was 17.8%. Circulating levels of inflammatory factors were increased in individuals homozygous for the defective allele CYP2C19*2 (A) notably IL-6 in the whole sample (P= 0.0008) and hs-CRP only in women (P= 0.008), with a significant interaction with sex (P= 0.005), in comparison to carriers of one copy or more of the wild type allele CYP2C19*1 (G). Only a trend of association (P= 0.089) was found between this polymorphism and TNF-alpha concentration in the whole sample. The association between CYP2C19*2 polymorphism and inflammatory markers' concentrations could suggest that CYP2C19 may be considered as a new candidate gene for cardiovascular risks via inflammation.

Pharmacogenomics and antihypertensive drugs: a path toward personalized medicine

Pharmacogenomics focuses on genes and the transcriptome and proteome. It has the potential to enhance healthcare management by improving disease diagnosis and implementing treatments adapted to each patient. Previously, pharmacogenetics of candidate genes focused on clinical research. It is now extended by using genome-wide approaches to elucidate the inherited basis of differences between individuals in their response to drugs. We summarize relevant polymorphisms of genes involved in the pharmacokinetics and pharmacodynamics of antihypertensive drugs and we give an overview of the state of pharmacogenomic research in hypertension medicine. Even if things are getting better, current pharmacogenetic studies still lack power, adequate selection of candidate genes and knowledge of their functions at the physiological level. Finally, some specific end point phenotypes (i.e., peptides or proteins related to the metabolic cycle targeted by the drug) should be integrated to propose data that are easily applicable to personalized medicine.

Effect of HMGCoA reductase inhibitors on cytochrome P450 expression in endothelial cell line

Endothelial cells and smooth muscle cells are the major cells that constitute blood vessels, and endothelial cells line the lumen of blood vessels. These 2 types of cells also play an integral role in the regional specialization of vascular structure. On the basis of these observations, we designed our study to investigate the effect of various statins on CYP expression in endothelial cells. 3-hydroxymethyl coenzyme A reductase inhibitors play an important role in vascular function. The majority of the statins available on the market show extensive metabolism by cytochrome P450 (CYP) enzymes. Both cell types are involved in the bioconversion of arachidonic acid into vasoactive compounds. The aim of this study was to demonstrate the effect of statins on cytochrome P450 expression in endothelial cells. Our results show that endothelial cells expressed both CYPs involved in epoxyeicosatrienoic acids (EETs) and hydroxyeicosatetraenoic acids (HETEs) production and the nuclear receptor implicated in cytochrome P450 regulation. Treatment of endothelial cells with lovastatin increased CYP2C9 expression. After 96 hours of treatment, fluvastatin and lovastatin clearly increased CYP2C9 protein level. CAR but not PXR was expressed in endothelial cells, indicating that the upregulating effect of statins on CYP2C9 in endothelial cells could be mediated through CAR only due to the lack of expression of PXR in these cells.