Franck Desmoulin

The vasoactive peptide adrenomedullin is secreted by adipocytes and inhibits lipolysis through NO-mediated β-adrenergic agonist oxidation

Adipocytes are known to secrete a number of adipokines, but many adipocyte secretions and their functional importance remain to be characterized. This work shows that human white adipocytes and 3T3‐F442A‐derived adipocytes produce adrenomedullin (AM) and that AM acts in an autocrine/paracrine way on lipid metabolism by extracellular inactivation of isoproterenol, a β‐adrenergic agonist. AM is described as a counter‐regulatory factor involved in the control of cardiovascular homeostasis. This peptide is believed to protect the heart from several complications implicated in obesity‐linked cardiomorbidity, such as arterial hypertension, cardiac fibrosis, and decreased sinusal variability. The exact source of circulating AM remains a matter of debate, although endothelial and vascular smooth muscle cells seem to be important sites of production. We show that human adipose cells and 3T3‐F442A‐derived adipocytes express AM receptors and secrete AM. The function of this feature was investigated in 3T3‐F442A cell line at the level of lipolysis regulation. AM inhibited β‐adrenergic‐stimulated lipolysis by a nitric oxide (NO)‐dependent mechanism, inducing a significant decrease in pD2 value for isoproterenol (8.6 ± 0.2 vs. 9.8 ± 0.1, P<0.001). This effect is cGMP‐independent since it occurred in the presence of the NO‐sensitive guanylate cyclase inhibitor ODQ. It is apparently mediated by a novel extracellular mechanism. Liquid chromatography‐tandem mass spectrometry (LC‐MS/MS) demonstrated that AM‐produced NO oxidized isoproterenol to generate its aminochrome, namely isoprenochrome. Isoprenochrome amounts were increased 3.62 ± 1.13‐fold in cell culture media (P<0.05). We describe for the first time that AM down‐regulates lipolysis in adipocytes through the chemical modification of a β‐agonist.

Apolipoprotein O is mitochondrial and promotes lipotoxicity in heart

Diabetic cardiomyopathy is a secondary complication of diabetes with an unclear etiology. Based on a functional genomic evaluation of obesity-associated cardiac gene expression, we previously identified and cloned the gene encoding apolipoprotein O (APOO), which is overexpressed in hearts from diabetic patients. Here, we generated APOO-Tg mice, transgenic mouse lines that expresses physiological levels of human APOO in heart tissue. APOO-Tg mice fed a high-fat diet exhibited depressed ventricular function with reduced fractional shortening and ejection fraction, and myocardial sections from APOO-Tg mice revealed mitochondrial degenerative changes. In vivo fluorescent labeling and subcellular fractionation revealed that APOO localizes with mitochondria. Furthermore, APOO enhanced mitochondrial uncoupling and respiration, both of which were reduced by deletion of the N-terminus and by targeted knockdown of APOO. Consequently, fatty acid metabolism and ROS production were enhanced, leading to increased AMPK phosphorylation and Ppara and Pgc1a expression. Finally, we demonstrated that the APOO-induced cascade of events generates a mitochondrial metabolic sink whereby accumulation of lipotoxic byproducts leads to lipoapoptosis, loss of cardiac cells, and cardiomyopathy, mimicking the diabetic heart-associated metabolic phenotypes. Our data suggest that APOO represents a link between impaired mitochondrial function and cardiomyopathy onset, and targeting APOO-dependent metabolic remodeling has potential as a strategy to adjust heart metabolism and protect the myocardium from impaired contractility.

In vivo 31P and 1H HR-MAS NMR spectroscopy analysis of the unstarved Aporrectodea caliginosa (Lumbricidae)

This study demonstrates that 31P and 1H high resolution-magic angle spinning (HR-MAS) nuclear magnetic resonance (NMR), a recently developed NMR technique, can be applied to the in vivo analysis of metabolites from an unstarved earthworm. The endogeic earthworm Aporrectodea caliginosa was cut into lengths and then the different body parts (anterior, middle, posterior) with the gut content were analyzed. With the HR-MAS NMR, metabolites show well-resolved signals, whereas, with conventional NMR, spectra are highly dependent on the gut content. 31P HR-MAS NMR has been used to evaluate the effect of an acute exposure of the earthworm to glyphosate. Our observations support a low toxicity of the herbicide and suggest that glyphosate could be trapped in the cutaneous mucus. Earthworms could therefore play a role in horizontal dispersion and stabilization of glyphosate in the drilosphere. Phosphorylated metabolites, such as phospholombricine and lombricine, were clearly identified and their amount measured during experiments. The 1H HR-MAS NMR method offers the opportunity to measure, on the same sample and simultaneously, both the hydrosoluble metabolites and lipids. The data on lipid location and relative succinate concentration shed light on the physiological and metabolic functions of the different body parts of the earthworm.

Blood signature of pre-heart failure: a microarrays study.

Background The preclinical stage of systolic heart failure (HF), known as asymptomatic left ventricular dysfunction (ALVD), is diagnosed only by echocardiography, frequent in the general population and leads to a high risk of developing severe HF. Large scale screening for ALVD is a difficult task and represents a major unmet clinical challenge that requires the determination of ALVD biomarkers. Methodology/Principal Findings 294 individuals were screened by echocardiography. We identified 9 ALVD cases out of 128 subjects with cardiovascular risk factors. White blood cell gene expression profiling was performed using pangenomic microarrays. Data were analyzed using principal component analysis (PCA) and Significant Analysis of Microarrays (SAM). To build an ALVD classifier model, we used the nearest centroid classification method (NCCM) with the ClaNC software package. Classification performance was determined using the leave-one-out cross-validation method. Blood transcriptome analysis provided a specific molecular signature for ALVD which defined a model based on 7 genes capable of discriminating ALVD cases. Analysis of an ALVD patients validation group demonstrated that these genes are accurate diagnostic predictors for ALVD with 87% accuracy and 100% precision. Furthermore, Receiver Operating Characteristic curves of expression levels confirmed that 6 out of 7 genes discriminate for left ventricular dysfunction classification. Conclusions/Significance These targets could serve to enhance the ability to efficiently detect ALVD by general care practitioners to facilitate preemptive initiation of medical treatment preventing the development of HF.

Interest of Fluorine-19 Nuclear Magnetic Resonance Spectroscopy in the Detection, Identification and Quantification of Metabolites of Anticancer and Antifungal Fluoropyrimidine Drugs in Human Biofluids

Background: The metabolism of fluorouracil and fluorocytosine, two 5-fluoropyrimidine drugs in clinical use, was investigated. Methods:19F nuclear magnetic resonance (NMR) spectroscopy was used as an analytical technique for the detection, identification and quantification of fluorinated metabolites of these drugs in intact human biofluids as well as fluorinated degradation compounds of fluorouracil in commercial vials. Results:19F NMR provides a highly specific tool for the detection and absolute quantification, in a single run, of all the fluorinated species, including unexpected substances, present in biofluids of patients treated with fluorouracil or fluorocytosine. Besides the parent drug and the already known fluorinated metabolites, nine new metabolites were identified for the first time with 19F NMR in human biofluids. Six of them can only be observed with this technique: fluoride ion, N-carboxy-α-fluoro-β-alanine, α-fluoro-β-alanine conjugate with deoxycholic acid, 2-fluoro-3-hydroxypropanoic acid, fluoroacetic acid, O2-β-glucuronide of fluorocytosine. Conclusion:19F NMR studies of biological fluids of patients treated with anticancer fluorouracil or antifungal fluorocytosine have furthered the understanding of their catabolic pathways.

Benefits of cardiac rehabilitation in heart failure patients according to etiology: INCARD French study.

AbstractWe investigated the impact of heart failure (HF) etiology on the outcome of cardiac rehabilitation (CR) assessed by functional and clinical parameters.Treatment of chronic HF requires multidisciplinary approaches with a recognized role for CR. INCARD is a French study aimed at evaluating the benefits of sustainable CR in coronary (C) and noncoronary patients (NC) treated and educated during a 24-month period of follow-up.Prospective, monocentric patients with HF underwent inpatient physical training followed by a home-based program. Evaluations were performed at inclusion, discharge, 3 months after discharge, and subsequently every 6 months over the 24 months of outpatient rehabilitation.A total of 147 HF patients with left ventricular ejection fraction (LVEF) <40 were admitted to the CR center, 63 accepted to join INCARD (29 C and 34 NC).Although the C participants C having both an echocardiographic LVEF and an initially lower peak VO2, inpatient rehabilitation improved all functional parameters. Only NC showed an improved LVEF during the first 3 months of outpatient-follow-up. The main outcome of the outpatient rehabilitation was a trend toward stabilization of clinical and laboratory parameters with no significant difference between C and NC.This study confirms the benefits of initial HF inpatient rehabilitation and encourages prolonged outpatient monitoring. The results on functional parameters suggest exercise training should be conducted regardless of the HF etiology.

Paradoxical Effect of Nonalcoholic Red Wine Polyphenol Extract, Provinols™, in the Regulation of Cyclooxygenases in Vessels from Zucker Fatty Rats (fa/fa)

The aim of this work was to study the vascular effects of dietary supplementation of a nonalcoholic red wine polyphenol extract, Provinols, in Zucker fatty (ZF) obese rats. ZF or lean rats received diet supplemented or not with Provinols for 8 weeks. Vasoconstriction in response to phenylephrine (Phe) was then assessed in small mesenteric arteries (SMA) and the aorta with emphasis on the contribution of cyclooxygenases (COX). Although no difference in vasoconstriction was observed between ZF and lean rats both in SMA and the aorta, Provinols affected the contribution of COX-derived vasoconstrictor agents. The nonselective COX inhibitor, indomethacin, reduced vasoconstriction in vessels from both groups; however, lower efficacy was observed in Provinols-treated rats. This was associated with a reduction in thromboxane-A2 and 8-isoprostane release. The selective COX-2 inhibitor, NS398, reduced to the same extent vasoconstriction in aortas from ZF and Provinols-treated ZF rats. However, NS398 reduced response to Phe only in SMA from ZF rats. This was associated with a reduction in 8-isoprostane and prostaglandin-E release. Paradoxically, Provinols decreased COX-2 expression in the aorta, while it increased its expression in SMA. We provide here evidence of a subtle and paradoxical regulation of COX pathway by Provinols vessels from obese rats to maintain vascular tone within a physiological range.

Increased mean aliphatic lipid chain length in left ventricular hypertrophy secondary to arterial hypertension: A cross-sectional study.

AbstractAbout 77.9 million (1 in 4) American adults have high blood pressure. High blood pressure is the primary cause of left ventricular hypertrophy (LVH), which represents a strong predictor of future heart failure and cardiovascular mortality. Previous studies have shown an altered metabolic profile in hypertensive patients with LVH. The goal of this study was to identify blood metabolomic LVH biomarkers by 1H NMR to provide novel diagnostic tools for rapid LVH detection in populations of hypertensive individuals. This cross-sectional study included 48 hypertensive patients with LVH matched with 48 hypertensive patients with normal LV size, and 24 healthy controls. Two-dimensional targeted M-mode echocardiography was performed to measure left ventricular mass index. Partial least squares discriminant analysis was used for the multivariate analysis of the 1H NMR spectral data. From the 1H NMR-based metabolomic profiling, signals coming from methylene (–CH2–) and methyl (–CH3) moieties of aliphatic chains from plasma lipids were identified as discriminant variables. The –CH2–/–CH3 ratio, an indicator of the mean length of the aliphatic lipid chains, was significantly higher (P < 0.001) in the LVH group than in the hypertensive group without LVH and controls. Receiver operating characteristic curve showed that a cutoff of 2.34 provided a 52.08% sensitivity and 85.42% specificity for discriminating LVH (AUC = 0.703, P-value < 0.001). We propose the –CH2–/–CH3 ratio from plasma aliphatic lipid chains as a biomarker for the diagnosis of left ventricular remodeling in hypertension.

103 White blood cell genes expressions provide a molecular signature for pre-heart failure

Fatima Smih (1), Franck Desmoulin (2), Matthieu Berry (1), Annie Turkieh (2), Romain Harmancey (1), Jason Iacovoni (2), Charlotte Trouillet (1), Clement Delmas (1), Atul Pathak (2), Olivier Lairez (2), Francois Koukoui(1), Pierre Massabuau (1), Jean Ferrieres (3), Michel Galinier (1), Philippe Rouet [Orateur] (1) (1) INSERM U1048, Equipe 7 “Obesite et insuffisance cardiaque”, Toulouse, France – (2) I2MC Inserm UMR 1048, Toulouse, France – (3) Inserm U1027, CHU Toulouse, Cardiologie, Toulouse, France

Metabolism of a novel nucleoside analogue, OGT 719, in the isolated perfused rat liver model, in rats, in tumour models and in patients.

1. The metabolic pathway(s) of OGT 719, a novel nucleoside analogue in which galactose is covalently attached to the N1 of 5-fluorouracil (FU), have been investigated with 19 F-NMR spectroscopy in (1) the isolated perfused rat liver (IPRL) model, (2) normal rats, (3) rats bearing the HSN LV10 sarcoma, (4) nude mice xenografted with the human hepatoma HepG2 and (5) urine from patients. 2. The administration of OGT 719 results in the formation of small amounts of FU. IPRL experiments with OGT 719 in combination with asialofetuin, a natural asialoglycoprotein receptor (ASGP-r), suggest competitive binding of OGT 719 to the ASGP-r. 3. The data obtained in non-tumour rats also demonstrated an extremely low metabolization of OGT 719 into FU and α -fluoro- β -alanine, the well-known major metabolite of FU. 4. A comparison of tumour extracts from rats bearing the HSN LV10 sarcoma treated with FU or OGT 719 showed the incorporation of FU into RNA in rats treated with FU but not in rats treated with OGT 719; nevertheless, the incorporation of FU into RNA was observed in the liver from rats treated with OGT 719. 5. In a human hepatoma xenografted to nude mice, both the OGT 719 and FU contents of the tumour were markedly higher than in the corresponding liver, suggesting a tumour-specific trapping of OGT 719 in hepatoma. 6. The metabolism of OGT 719 was also extremely low in patients. 7. In conclusion, the present study shows the value of 19 F-NMR for demonstrating for the first time that OGT 719 is a prodrug of FU although very poorly metabolized.