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.

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.

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.

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.

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.

[The neuropeptide 26RFa and its role in the regulation of energy metabolism].

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.

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.

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.

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.

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.

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.

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.

[Preanalytical variations of proteic biomarkers].

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.

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.

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.

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.

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.

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.

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.