Interactions between the regulatory peptide 26RFa (QRFP) and insulin in the regulation of glucose homeostasis in two complementary models: The high fat 26RFa-deficient mice and the streptozotocin insulin-deficient mice.

The regulatory peptide 26RFa (QRFP) is involved in the control of glucose homeostasis at the periphery by acting as an incretin, and in the brain by mediating the central antihyperglycemic effect of insulin, indicating the occurrence of a close relationship between 26RFa and insulin in the regulation of glucose metabolism. Here, we investigated the physiological interactions between 26RFa and insulin in two complementary models i.e. a model of obese/hyperglycemic mice deficient for 26RFa and a model of diabetic mice deficient for insulin. For this, transgenic 26RFa-deficient mice were made obese and chronically hyperglycemic by a 3-month high fat diet (HFD) and second group of mice was made diabetic by destruction of the ß cells of the pancreatic islets using a single injection of streptozotocin. Our data reveal that 26RFa deficiency does not impact significantly the "glycemic" phenotype of the HFD mice. The pancreatic islets, liver, white adipose tissue masses are not altered by the lack of 26RFa production but the brown adipose tissue (BAT) weight is significantly increased in these animals. In diabetic insulin-deficient mice, the injection of 26RFa does not exhibit any beneficial effect on the impaired glucose homeostasis characterizing this model. Finally, we show that streptozotocin diabetic mice display lowered plasma 26RFa levels as compared to untreated mice, whereas the expression of the peptide in the duodenum is not affected. Taken together, the present results indicate that dysregulation of glucose homeostasis in obese/hyperglycemic mice is not aggravated by the absence of 26RFa that may be compensated by the increase of BAT mass. In diabetic insulin-deficient mice, the antihypergycemic effect of 26RFa is totally blunted probably as a result of the impaired insulin production characterizing this model, avoiding therefore the action of the peptide.

Acute but Not Chronic Central Administration of the Neuropeptide 26RFa (QRFP) Improves Glucose Homeostasis in Obese/Diabetic Mice.

INTRODUCTION: The aim of the study is to investigate whether acute or chronic central administration of the hypothalamic neuropeptide 26RFa may ameliorate the glycemic control of obese/diabetic mice. METHODS: Mice were treated for 4 months with a high-fat (HF) diet and received a single i.c.v. injection of 26RFa (3 µg) or a chronic i.c.v. administration of the peptide during 28 days via osmotic minipumps (25 µg/day). i.p. and oral glucose (GLU) tolerance tests, insulin (INS) tolerance test, glucose-stimulated insulin secretion (GSIS), food/water intake, horizontal/vertical activity, energy expenditure, meal pattern, and whole-body composition were monitored. In addition, 26RFa and GPR103 mRNA expressions as well as plasma 26RFa levels were evaluated by RT-QPCR and radioimmunoassay. RESULTS: Acute administration of 26RFa in HF mice induced a robust antihyperglycemic effect by enhancing INS secretion, whereas chronic administration of the neuropeptide is unable to improve glucose homeostasis in these obese/diabetogenic conditions. By contrast, chronic 26RFa treatment induced an increase of the body weight accompanied with an enhanced food intake and a decreased energy expenditure. Finally, we show that the HF diet does not alter the hypothalamic expression of the 26RFa/GPR103 neuropeptidergic system nor the levels of circulating 26RFa. CONCLUSION: Our data indicate that the central beneficial effect of 26RFa on glucose homeostasis, by potentiating GSIS, is preserved in HF mice. However, chronic administration of the neuropeptide is unable to balance glycemia in these pathophysiological conditions, suggesting that the hypothalamic 26RFa/GPR103 neuropeptidergic system mainly affects short-term regulation of glucose metabolism.

The neuropeptide 26RFa in the human gut and pancreas: potential involvement in glucose homeostasis.

OBJECTIVE: Recent studies performed in mice revealed that the neuropeptide 26RFa regulates glucose homeostasis by acting as an incretin and by increasing insulin sensitivity. However, in humans, an association between 26RFa and the regulation of glucose homeostasis is poorly documented. In this study, we have thus investigated in detail the distribution of 26RFa and its receptor, GPR103, in the gut and the pancreas, and determined the response of this peptidergic system to an oral glucose challenge in obese patients. DESIGN AND METHODS: Distribution of 26RFa and GPR103 was examined by immunohistochemistry using gut and pancreas tissue sections. Circulating 26RFa was determined using a specific radioimmunoassay in plasma samples collected during an oral glucose tolerance test. RESULTS: 26RFa and GPR103 are present all along the gut but are more abundant in the stomach and duodenum. In the stomach, the peptide and its receptor are highly expressed in the gastric glands, whereas in the duodenum, ileum and colon they are present in the enterocytes and the goblet cells. In the pancreatic islets, the 26RFa/GPR103 system is mostly present in the ß cells. During an oral glucose tolerance test, plasma 26RFa profile is different between obese patients and healthy volunteers, and we found strong positive correlations between 26RFa blood levels and the BMI, and with various parameters of insulin secretion and insulin resistance. CONCLUSION: The present data suggest an involvement of the 26RFa/GPR103 peptidergic system in the control of human glucose homeostasis.

Neuropeptide 26RFa (QRFP) is a key regulator of glucose homeostasis and its activity is markedly altered in obese/hyperglycemic mice.

Recent studies have shown that the hypothalamic neuropeptide 26RFa regulates glucose homeostasis by acting as an incretin and increasing insulin sensitivity. In this study, we further characterized the role of the 26RFa/GPR103 peptidergic system in the global regulation of glucose homeostasis using a 26RFa receptor antagonist and also assessed whether a dysfunction of the 26RFa/GPR103 system occurs in obese hyperglycemic mice. First, we demonstrate that administration of the GPR103 antagonist reduces the global glucose-induced incretin effect and insulin sensitivity whereas, conversely, administration of exogenous 26RFa attenuates glucose-induced hyperglycemia. Using a mouse model of high-fat diet-induced obesity and hyperglycemia, we found a loss of the antihyperglcemic effect and insulinotropic activity of 26RFa, accompanied with a marked reduction of its insulin-sensitive effect. Interestingly, this resistance to 26RFa is associated with a downregulation of the 26RFa receptor in the pancreatic islets, and insulin target tissues. Finally, we observed that the production and release kinetics of 26RFa after an oral glucose challenge is profoundly altered in the high-fat mice. Altogether, the present findings support the view that 26RFa is a key regulator of glucose homeostasis whose activity is markedly altered under obese/hyperglycemic conditions.

The Neuropeptide 26RFa (QRFP) and Its Role in the Regulation of Energy Homeostasis: A Mini-Review.

This mini-review deals with the neuropeptide 26RFa (or QRFP) which is a member of the RFamide peptide family discovered simultaneously by three groups in 2003. 26RFa (or its N-extended form 43RFa) was subsequently shown to be the endogenous ligand of the human orphan receptor GPR103. In the brain, 26RFa and GPR103mRNA are primarily expressed in hypothalamic nuclei involved in the control of feeding behavior, and at the periphery, the neuropeptide and its receptor are present in abundance in the gut and the pancreatic islets, suggesting that 26RFa is involved in the regulation of energy metabolism. Indeed, 26RFa stimulates food intake when injected centrally, and its orexigenic effect is even more pronounced in obese animals. The expression of 26RFa is up-regulated in the hypothalamus of obese animals, supporting that the 26RFa/GPR103 system may play a role in the development and/or maintenance of the obese status. Recent data indicate that 26RFa is also involved in the regulation of glucose homeostasis. 26RFa reduces glucose-induced hyperglycemia, increases insulin sensitivity and insulinemia. Furthermore, an oral ingestion of glucose strongly stimulates 26RFa release by the gut, indicating that 26RFa is a novel incretin. Finally, 26RFa is able to prevent pancreatic ß cell death and apoptosis. This brief overview reveals that 26RFa is a key neuropeptide in the regulation of energy metabolism. Further fields of research are suggested including the pathophysiological implication of the 26RFa/GPR103 system.

[The neuropeptide 26RFa and its role in the regulation of energy metabolism]. / Le neuropeptide 26RFa : un nouveau régulateur de l'homéostasie énergétique.

The neuropeptide 26RFa, also referred to as QRFP (for pyroglutamilated RFamide peptide), is the latest member of the RFamide peptide family to be discovered. 26RFa and its N-extended form, 43RFa, have been characterized in all vertebrate classes as the endogenous ligands of the human orphan receptor GPR103. In the brain, 26RFa and GPR103mRNA are primarily expressed in hypothalamic nuclei involved in the control of feeding behavior, and in the periphery, the neuropeptide and its receptor are present in abundance in the gut and the pancreatic islets, suggesting that 26RFa is involved in the regulation of energy metabolism. Indeed, 26RFa stimulates food intake when centrally injected, and its orexigenic effect is even more pronounced in obese animals. The expression of 26RFa is up-regulated in the hypothalamus of obese animals, supporting the view that 26RFa may play a role in the development and/or maintenance of the obese status. Recent data indicate that 26RFa is also involved in the regulation of glucose homeostasis. 26RFa reduces glucose-induced hyperglycemia, increases insulin sensitivity and insulinemia. Furthermore, an oral ingestion of glucose strongly stimulates 26RFa release by the gut, indicating that 26RFa is a novel incretin. Finally, 26RFa is able to prevent pancreatic ß cell death and apoptosis. In conclusion, this overview of the literature reveals that 26RFa is a key neuropeptide in the regulation of energy metabolism. Further fields of research are suggested including the pathophysiological implication of the 26RFa/GPR103 system.

Hypothalamic Neuropeptide 26RFa Acts as an Incretin to Regulate Glucose Homeostasis.

26RFa is a hypothalamic neuropeptide that promotes food intake. 26RFa is upregulated in obese animal models, and its orexigenic activity is accentuated in rodents fed a high-fat diet, suggesting that this neuropeptide might play a role in the development and maintenance of the obese status. As obesity is frequently associated with type 2 diabetes, we investigated whether 26RFa may be involved in the regulation of glucose homeostasis. In the current study, we show a moderate positive correlation between plasma 26RFa levels and plasma insulin in patients with diabetes. Plasma 26RFa concentration also increases in response to an oral glucose tolerance test. In addition, we found that 26RFa and its receptor GPR103 are present in human pancreatic ß-cells as well as in the gut. In mice, 26RFa attenuates the hyperglycemia induced by a glucose load, potentiates insulin sensitivity, and increases plasma insulin concentrations. Consistent with these data, 26RFa stimulates insulin production by MIN6 insulinoma cells. Finally, we show, using in vivo and in vitro approaches, that a glucose load induces a massive secretion of 26RFa by the small intestine. Altogether, the present data indicate that 26RFa acts as an incretin to regulate glucose homeostasis.

Metabolic syndrome-related composite factors over 5 years in the STANISLAS family study: genetic heritability and common environmental influences.

BACKGROUND: We estimated genetic heritability and common environmental influences for various traits related to metabolic syndrome in young families from France. METHODS: At entrance and after 5 years, nineteen traits related to metabolic syndrome were measured in a sample of families drawn from the STANISLAS study. In addition, 5 aggregates of these traits were identified using factor analysis. RESULTS: At entrance, genetic heritability was high (20 to 44%) for plasma lipids and lipoproteins, uric acid, fasting glucose, and the related clusters "risk lipids" and "protective lipids". Intermediate or low genetic heritability (less than 20%) was shown for triglycerides, adiposity indices, blood pressure, hepatic enzyme activity, inflammatory makers and the related clusters: "liver enzymes", "adiposity/blood pressure" and "inflammation". Moreover, common environmental influences were significant for all the parameters. With regard to 5-year changes, polygenic variance was low and not statistically significant for any of the individual variables or clusters whereas shared environment influence was significant. CONCLUSIONS: In these young families, genetic heritability of metabolic syndrome-related traits was generally lower than previously reported while the common environmental influences were greater. In addition, only shared environment contributed to short-term changes of these traits.

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 between EGF and lipid concentrations: a benefit role in the atherosclerotic process?

CONTEXT AND OBJECTIVE: Previous in vitro studies have shown a relationship between epidermal growth factor (EGF) and lipid metabolism. Indeed, EGF is able to modulate lipoprotein fractions in human fetal intestine and hepatic-derived cell lines. The aim of this study was to search for potential associations between EGF concentrations and lipid parameters in both plasma and peripheral blood mononuclear cells (PBMCs) among healthy individuals. DESIGN: EGF concentrations were quantified in plasma of 273 men and 279 women and in PBMCs of 57 men and 62 women from the STANISLAS cohort. In addition, basic blood constituents including lipid parameters (apolipoproteins A1, and B, total and high-density lipid (HDL)-cholesterols and triglycerides) were measured. RESULTS: Plasma EGF concentrations were significantly and positively correlated with apolipoprotein A1 and HDL-cholesterol concentrations after adjustment for age, sex, and body mass index (r=0.155, P=0.0003; and r=0.112, P=0.0086, respectively). They were also negatively correlated with the apolipoprotein B/A1 ratio (r=-0.107, P=0.012). In addition, EGF concentrations in PBMCs were negatively correlated with apolipoprotein B, total and low-density lipid-cholesterols, and triglyceride concentrations, and apolipoprotein B/A1 ratio (P=0.0018, P=0.0137, P=0.0142, P=0.0162, and P=0.0077, respectively, with r ranging between -0.287 and -0.222). No interactions were found with gender. CONCLUSION: New associations between EGF and lipid concentrations have been reported, providing new perspectives with regard to the role of EGF in atherosclerosis.

Genetic profiling of human cell lines used as in vitro model to study cardiovascular pathophysiology and pharmacotoxicology.

BACKGROUND: Cell lines are widely used to monitor drug pharmacokinetics and pharmacodynamics and to investigate a number of biochemical mechanisms. However, little is known about the genetic profile of these in vitro models. OBJECTIVES: To analyze genetic profile of Thp1, U937, HL60, K562, HepG2, Kyn2, and Caco2 human cell lines with a focus on genetic variations within genes involved in the development of cardiovascular pathologies and drug treatment response. METHODS: Multiplex polymerase chain reaction (PCR), PCR-restriction fragment length polymorphism and TaqMan assays were used to genotype 120 polymorphisms within 68 genes previously shown to be involved in various processes such as inflammation, lipid metabolism, and blood pressure. RESULTS: We provide here a list of potential polymorphisms known to be associated with cardiovascular disease. Our results show that the seven cell lines examined carry several of these mutations within genes of interest. Due to the abundance of these variations, only two examples will be given in this abstract. For instance, U937 cells are homozygous for APOE varepsilon4, a mutant associated with higher susceptibility to cardiovascular diseases and lower response to statins. Our study also showed that deletion in intron 16 of the ACE gene, which is associated with susceptibility to hypertension and variation of response to ACE inhibitors, can be found in all considered cells but Kyn2 cells. CONCLUSION: We provide here a data bank of different cell lines genetic profile. In our opinion, this useful information may bring insights into the design and choice of an adequate in vitro model and may help to explain mysterious discrepancies in data from different laboratories.

[Preanalytical variations of proteic biomarkers]. / Variations pré-analytiques des biomarqueurs protéiques.

In the area of proteomic, results of analysis were for a long time dependant on analytical variations. Nowadays, due to the emergence of new technologies and controls of data, these variations are less important than those due to preanalytical conditions, which are difficult to overcome. The reasons are due to the number of parameters and to the fact that the biologist is not always fully informed. In this document, we present the main preanalytical factors of variation, and their effects on the results of analysis. New technologies involving mass spectrometry are very promising, but they are very sensitive to parameters like the stability of samples and the choice of the clotting agent. Thus, it is more and more necessary to take these data into account.

Peripheral blood mononuclear cells (PBMCs): a possible model for studying cardiovascular biology systems.

BACKGROUND: The inflammation system, alone or in relation to or interaction with other cardiovascular pathways, is suggested to be the central pathway in the development and progression of cardiovascular diseases. The aim of the present investigation was to propose a specific and informative model for exploring this hypothesis. METHODS: In a biological system approach, we studied the expression of 182 candidate cardiovascular genes in peripheral blood mononuclear cells (PBMCs), cells that provide specific information on the inflammatory pathway. We explored their expression in 20 individuals with or without risk factors (obesity, hypertension) for cardiovascular disease. RESULTS: We found that: 1) 166 among the 182 selected genes were expressed in at least one individual's PBMCs, some of them being detected for the first time in this tissue; 2) all pathways were represented by the majority of their genes selected; 3) genes were expressed at a level sufficient for further study of the inter-individual variations in their mRNA to determine their biological variation; and 4) 15 genes discriminated hypertensive from obese or controls. CONCLUSIONS: The results of the present investigation support our proposal of a promising novel strategy based on PBMC transcriptomic studies to elucidate the complexity of the cardiovascular system in relation to inflammation. Preliminary data support the usefulness of the PBMC model in hypertension/inflammation research.

Association of classical and related inflammatory markers with high-sensitivity C-reactive protein in healthy individuals: results from the Stanislas cohort.

BACKGROUND: Although high-sensitivity C-reactive protein (hs-CRP) has emerged as a cardiovascular marker, questions arise regarding the relative information provided by other inflammatory molecules. Therefore, as a first step, we examined interrelationships between serum hs-CRP concentrations and inflammatory, adhesion and growth factors in healthy adults. METHODS: Circulating concentrations of hs-CRP, haptoglobin, orosomucoid, interleukin-6 (IL-6), IL-8, IL-18, tumor necrosis factor-alpha (TNF-alpha), TNF-receptor II (TNF-RII), E-, P-, and L-selectins, intercellular adhesion molecule-1 (ICAM-1), monocyte chemoattractant protein-1, endothelial growth factor (EGF), vascular EGF (VEGF), insulin-like growth factor-1 (IGF-1) and IGF-binding protein (IGFBP-3) were measured in 154 men and 161 women of the Stanislas cohort. Leukocyte and platelet counts were also determined. RESULTS: Correlations were significant between hs-CRP concentrations and leukocyte and platelet counts, as well as haptoglobin, orosomucoid, IL-6, and ICAM-1 concentrations (p< or =0.001). Correlation coefficients for ICAM-1 were higher in men than in women (p< or =0.05). When stratifying subjects according to hs-CRP levels, the group with high hs-CRP levels had significantly higher haptoglobin and orosomucoid concentrations than the others, in addition to higher leukocyte counts and IL-6 concentrations in women, and platelet counts and ICAM-1 concentrations in men. CONCLUSIONS: Further studies are warranted to explain the association pattern for hs-CRP. Partition of these factors according to their association with hs-CRP concentration opens a new perspective for choice of the best factors in terms of cardiovascular risk in relation to hs-CRP, while non-associated markers could be used to give additional information.

Heritability for plasma VEGF concentration in the Stanislas family study.

Vascular endothelial growth factor (VEGF), a key regulator of blood vessel function during angiogenesis, has been related to various diseases including atherosclerosis, neurodegenerative disorders and cancers. However, data about genetic determinants of its concentration in blood are scarce. The present study aimed at estimating additive genetic heritability, household component effect and the influence of 3 common VEGF polymorphisms on plasma VEGF concentration. A random sub-sample of 160 nuclear families (647 individuals), aging from 5 to 57, was obtained from the Stanislas Family Study. Plasma VEGF concentration was measured by a multiplexing ELISA and genotyping of the polymorphisms C(-460)T, G(405)C and C(936)T of the VEGF gene was carried out by RFLP. After adjustment for the influence of known environmental covariates, significant familial correlations were observed for plasma VEGF concentration (P< or = 0.01 and P< or = 0.001) for all the various pairs of relatives, except between spouses. In addition, variance component analysis showed no significant household common environment contribution to variability of this trait, while the genetic contribution accounted for 60.6% regardless of the 4 classes of relatives. Taking the three polymorphisms into account did not modify the variance components. These results show that plasma VEGF concentrations are under genetic control in healthy families and that none of the 3 candidate polymorphisms significantly altered heritability.

Association between TNF and IL-1 bloc polymorphisms and plasma MCP-1 concentration.

BACKGROUND: Circulating MCP-1 concentration was found to be increased in cardiovascular diseases and is of high interest in the list of biomarkers of atherosclerosis. TNF-alpha, LT-alpha, IL-1alpha and IL-1beta are four proinflammatory cytokines that regulate MCP-1 concentration in vitro. We hypothesized that specific genetic polymorphisms in TNF, LTA, IL-1A and IL-1B genes could modulate plasma MCP-1 concentration. METHODS: Plasma MCP-1 concentration was quantified with a biochip array analyzer in 395 adults from the Stanislas family study. TNF -308G>A, LTA 252A>G (A=TNFB2, G=TNFB1), IL-1A -889C>T and IL-1B 3954C>T were genotyped with a prototypic multilocus genotyping assay. RESULTS: Among the four polymorphisms studied only LTA 252A>G and TNF -308G>A were significantly associated with plasma MCP-1 concentration (p=0.005 and p=0.038, respectively) after adjustment for covariates (age, sex, smoking, monocyte count and hematocrit). Carriers of the 252A allele or the -308G had lower MCP-1 concentrations than carriers of the 252G or the -308A alleles, respectively. Moreover, as TNF and LTA genes were in linkage disequilibrium, the TNF bloc haplotypes were compared with respect to MCP-1 concentration, and a significant association (p=0.021) was observed, due only to the LTA polymorphism. This association remained significant even after adjustment for TNF-alpha and hs-CRP concentrations. CONCLUSION: A functional polymorphism within the TNF bloc could modulate MCP-1 concentration and seems more likely to be near to the LTA 252A>G polymorphism than to the TNF -308G>A one. In addition, the association found in healthy French adults is independent of other actors of inflammation such as TNF-alpha and hs-CRP.

Biological determinants of and reference values for plasma interleukin-8, monocyte chemoattractant protein-1, epidermal growth factor, and vascular endothelial growth factor: Results from the STANISLAS cohort.

BACKGROUND: Interleukin-8 (IL-8), monocyte chemoattractant protein-1 (MCP-1), epidermal growth factor (EGF), and vascular endothelial growth factor (VEGF) are known to be involved in various diseases related to inflammation, vascular remodeling, or growth deregulation. In addition, increases in plasma concentrations of these cytokines appear to provide useful diagnostic and prognostic information. We therefore investigated which factors most strongly influence the biological variations of plasma IL-8, MCP-1, EGF, and VEGF concentrations. METHODS: We used the Evidence biochip array analyzer to quantify plasma IL-8, MCP-1, EGF, and VEGF concentrations in a subsample of 304 children (age range, 4-17 years) and 540 adults (age range, 18-55 years) from the STANISLAS family study. We also calculated reference intervals for the 4 cytokines. RESULTS: We found the following associations with plasma marker concentrations: Age, neutrophil count, and glucose concentration were positively associated with IL-8 concentrations in children and adults, as were smoking and platelet count in adults. MCP-1 concentrations were associated with age and smoking in both children and adults, monocyte count in children, and sex and hematocrit in adults. EGF concentrations were associated with platelet count in children and monocyte count and glucose in adults. VEGF concentrations were associated with age in children and adults and platelet count and alanine aminotransferase activity in adults. CONCLUSION: Our results for IL-8, MCP-1, EGF, and VEGF may be useful for interpretation of patients' laboratory results and for understanding the regulation of concentrations of these cytokines in physiologic conditions.

Pharmacogenomics and cardiovascular drugs: need for integrated biological system with phenotypes and proteomic markers.

Personalized medicine is based on a better knowledge of biological variability, considering the important part due to genetics. When trying to identify involved genes and their products in differential cardiovascular drug responses, a five-step strategy is to be followed: 1) Pharmacokinetic-related genes and phenotypes (2) Pharmacodynamic targets, genes and products (3) Cardiovascular diseases and risks depending on specific or large metabolic cycles (4) Physiological variations of previously identified genes and proteins (5) Environment influences on them. After summarizing the most well-known genes involved in drug metabolism, we will take as example of drugs, the statins, considered as very important drugs from a Public-Health standpoint, but also for economical reasons. These drugs respond differently in human depending on multiple polymorphisms. We will give examples with common ApoE polymorphisms influencing the hypolipemic effects of statins. These drugs also have pleiotropic effects and decrease inflammatory markers. This illustrates the need to separate clinical diseases phenotypes in specific metabolic pathways, which could propose other classifications, of diseases and related genes. Hypertension is also a good example of clinical phenotype which should be followed after various therapeutic approaches by genes polymorphisms and proteins markers. Gene products are under clear environmental expression variations such as age, body mass index and obesity, alcohol, tobacco and dietary interventions which are the first therapeutical actions taken in cardiovascular diseases. But at each of the five steps, within a pharmacoproteomic strategy, we also need to use available information from peptides, proteins and metabolites, which usually are the gene products. A profiling approach, i.e., dealing with genomics, but now also with proteomics, is to be used. In conclusion, the profiling, as well as the large amount of data, will more than before render necessary an organized interpretation of DNA, RNA as well as proteins variations, both at individual and population level.

Inter-individual variation of inflammatory markers of cardiovascular risks and diseases.

Cardiovascular diseases are a real public health problem and have multifactorial origin. Full comprehension of these diseases is very difficult because of their clinical and biological heterogeneity. The best way to understand the development of these diseases is to first investigate each biological system involved in the diseases and secondly, interactions between them. Studying intermediate phenotype variation for these biological systems is a new and promising approach for their elucidation. Among these metabolic systems, inflammation is known to be implicated in the occurrence and worsening of cardiovascular diseases. For this review, we chose to report the most important results concerning environmental, genetic and epigenetic determinants that influence intermediate phenotypes (protein and RNA levels) of inflammation. Indeed, numerous studies have investigated these determinants in healthy populations, in other words, without the influence of either disease or medication. This new approach will help to better understand the regulation of these intermediate phenotypes and to identify a panel of risk markers, which may be useful in predicting and warning those at risk and in giving adequate treatment to each patient.