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Biomedical subjects

M Parmentier

Publications and source records attributed to M Parmentier.

At least 19 recordsLinked to original sources

[Pain management in bone metastasis of pulmonary origin: new interventional and metabolic techniques].

Invasion of bone by a metastatic lesion is the most common cause of pain in cancer patients. Pain management in these patients is an important and difficult task. The pain is not always properly controlled by high doses of specific medication, radiation therapy or chemotherapy. When these therapies do not provide adequate pain relief, percutaneous vertebroplasty, cementoplasty, radiofrequency ablation and internal radiotherapy appear to be elegant and efficient complementary alternative pain control methods.

Bone Cements↗

[Smoking and pregnancy: survey among women enrolled in an independent worker insurance program].

OBJECTIVES: In order to further improve its prevention program entitled "Maternity childhood follow-up", the Paris region health insurance program for independent workers carried out a survey among female participants. The survey was designed to assess women's smoking behavior and evaluate reception of information concerning smoking-related risks and support available to stop smoking. The women's suggestions were also collected. MATERIALS AND METHODS: A questionnaire was sent by the physicians in charge of the Ile de France region to the 3525 women who had reported a pregnancy. RESULTS: 1099 answers were received (31%) The mean age of responders was 34.3 4.7 years. Their educational level was high (76% had a university degree). Before pregnancy, 37% were smokers. At the first trimester of pregnancy, 17% were smokers, 15% at the second trimester and 14% at the third trimester. Two years after childbirth, 20.5% were smokers. The proportion of women who stopped smoking was higher for those with a low Fagerström score. 29% of women said they did not receive any information about the harmful consequences of smoking. To cease smoking during pregnancy, 70% are helped by family and friends, 20% by health professionals; 3.5% took nicotine substitutes. CONCLUSION: This survey emphasises the need for improving information to pregnant women for alerting them to the dangers of smoking and for training the relevant health professionals.

Adult↗

[Characterization of new chemoattractant agents in leukocytes].

G protein-coupled receptors constitute one of the largest gene families in mammals. About a hundred orphan receptors still exist, for which the ligands and functions are unknown. We have recently identified the natural ligands of two orphan receptors expressed in dendritic cells and monocytes/macrophages. Chemerin, product of the gene Tig-2, was characterized as the ligand of the chemR23 receptor. The protein is synthesized as an inactive precursor, prochemerin, which requires the proteolytic removal of the last 6 or 7 amino acids, in order to generate a high affinity ligand of chemR23. Two neutrophil proteases, elastase and cathepsin G, are able to mediate this conversion. Besides, a peptide derived from the intracellular protein heme-binding protein (HBP) has been characterized as the first specific ligand of the FPRL2 receptor. The role of these two new systems in the control of physiological and pathological inflammatory reactions is presently being studied.

Amino Acid Sequence↗

Immunodetection of proteins from grapes and yeast in a white wine.

The objective of this study was to analyze the origin of proteins of a Chardonnay wine. Three various polyclonal antibodies raised against must, yeast, and bacteria proteins were produced. For microorganisms, only the secreted macromolecules were used. To this end, yeast and bacteria were cultured in a model medium under conditions close to those of winemaking. Results obtained using these specific antibodies indicate that most of the wine proteins came from grapes and many of them were glycoproteins. Some proteins of this Chardonnay wine came from the yeast; they were released during the alcoholic fermentation and consisted of high molecular weight mannoproteins. In contrast, no bacteria proteins were detected in this Chardonnay wine.

Animals↗

Caffeine reduces hypnotic effects of alcohol through adenosine A2A receptor blockade.

The role of the adenosine A(2A) receptor in the hypnotic effects of ethanol was assessed in mice. The duration of the loss of righting reflex following acute ethanol administration was shorter for A(2A) receptor-deficient mice (A(2A)R KO) than for wild-type mice (A(2A)R WT), whereas the fall in body temperature was not different between the two phenotypes. In contrast, the duration of the loss of righting reflex was increased in A(2A)R KO mice versus controls after administration of pentobarbital. Dipyridamole, an inhibitor of adenosine uptake, increased the sleep time observed following administration of ethanol in CD1 mice and in A(2A)R WT but not in A(2A)R KO mice. SCH 58261, a selective A(2A) receptor antagonist, unlike DPCPX, a selective A(1) receptor antagonist, shortened the duration of the loss of righting reflex induced by ethanol, thus mimicking the lack of receptor in deficient mice. Finally, the non-selective adenosine receptor antagonist caffeine (25 mg/kg) reduced ethanol-induced hypnotic effects. These results indicate that the activation of A(2A) receptors that follows an increase in extracellular adenosine levels caused by the administration of high doses of ethanol plays a role in its hypnotic effects. Thus, A(2A) receptor antagonists may be useful therapeutic agents for alleviating ethylic coma.

Adenosine A1 Receptor Antagonists↗

Adenosine A2A receptor gene disruption provokes marked changes in melanocortin content and pro-opiomelanocortin gene expression.

A2A receptor knockout (A2AR-/-) mice are more anxious and aggressive, and exhibit reduced exploratory activity than their wild-type littermates (A2AR+/+). Because alpha-melanocyte-stimulating hormone (alpha-MSH) influences anxiety, aggressiveness and motor activity, we investigated the effect of A2AR gene disruption on alpha-MSH content in discrete brain regions and pro-opiomelanocortin (POMC) expression in the hypothalamus and pituitary. No modification in alpha-MSH content was observed in the hypothalamus and medulla oblongata where POMC-expressing perikarya are located. In the arcuate nucleus of the hypothalamus, POMC mRNA levels were not affected by A2AR disruption. Conversely, in A2AR-/- mice, a significant increase in alpha-MSH content was observed in the amygdala and cerebral cortex, two regions that are innervated by POMC terminals. In the pars intermedia of the pituitary, A2AR disruption provoked a significant reduction of POMC mRNA expression associated with a decrease in alpha-MSH content. By contrast, in the anterior lobe of the pituitary, a substantial increase in POMC mRNA and adrenocorticotropin hormone concentrations was observed, and plasma corticosterone concentration was significantly higher in A2AR-/- mice, revealing hyperactivity of their pituitary-adrenocortical axis. Together, these results suggest that adenosine, acting through A2A receptors, may modulate the release of alpha-MSH in the cerebral cortex and amygdala. The data also indicate that A2A receptors are involved in the control of POMC gene expression and biosynthesis of POMC-derived peptides in pituitary melanotrophs and corticotrophs.

Animals↗

Lack of CB1 cannabinoid receptors modifies nicotine behavioural responses, but not nicotine abstinence.

Cannabis is the most widely consumed illicit drug and its consumption is currently associated with tobacco, which contains another psychoactive compound, namely nicotine. Interactions between cannabinoids and other drugs of abuse, such as opioids, have been previously reported. The aim of the present study was to evaluate the possible role of CB1 cannabinoid receptor in responses induced by acute and repeated nicotine administration by using knockout mice lacking the CB1 cannabinoid receptor and their wild-type littermates. Acute nicotine (0.5, 1, 3 and 6 mg/kg, sc) administration decreased locomotor activity and induced antinociceptive responses in the tail-immersion and the hot-plate test, in wild-type animals. The antinociceptive effects in the tail-immersion test were significantly enhanced in CB1 knockout mice. In wild-type mice nicotine (0.5 mg/kg, sc) produced a significant rewarding effect, as measured by a conditioned place preference paradigm. This response was absent in CB1 knockout mice. Finally, a model of mecamylamine-induced abstinence in chronic nicotine-treated mice (10 mg/kg/day, sc) was developed. Mecamylamine (1 and 2 mg/kg, sc) precipitated several somatic signs of nicotine withdrawal in wild-type dependent mice. However, no difference in the severity of nicotine withdrawal was observed in CB1 knockout mice. These results demonstrate that some acute effects and motivational responses elicited by nicotine can be modulated by the endogenous cannabinoid system and support the existence of a physiological interaction between these two systems.

Analgesics↗

[Secondary prevention of myocardial infarction in the Ile de France].

This enquiry was carried out to evaluate the measures of secondary prevention at 6 months and over of myocardial infarction in the ile de France region with respect to the recommendations of scientific societies and results of large scale therapeutic trials. A questionnaire was completed for the 1,215 patients selected from data obtained from the hospital discharge summary, interrogation and examination of the patient, and a telephone conversation with the attending physician. The data covered cardiovascular risk factors, the main clinical parameters, the results of biological tests and investigations carried out for risk stratification, plus different elements of therapeutic management. Compared with previous studies of the same type, this enquiry showed a favourable tendency towards the prescription of antithrombotic drugs and betablockers (98.3% and 82.4% of patients, respectively), and to patients with reputedly normal blood pressure values (84.7%). A positive result concerning the reduction in the number of smokers (17.4%) and the increase in lipid lowering prescriptions should be tempered by the fact that advice about stopping smoking was rarely given and that the quantitative target of LDL cholesterol was often ignored. Finally, the prescriptions of ACE inhibitors, physical exercise and cardiac rehabilitation remained well below the recommendations or recent scientific data.

Adrenergic beta-Antagonists↗

Amino-terminal truncation of CXCR3 agonists impairs receptor signaling and lymphocyte chemotaxis, while preserving antiangiogenic properties.

The interferon (IFN)-inducible chemokines, specifically, IFN-gamma-inducible protein-10 (IP-10), monokine induced by IFN-gamma (Mig), and IFN-inducible T-cell alpha-chemoattractant (I-TAC), share a unique CXC chemokine receptor (CXCR3). Recently, the highly specific membrane-bound protease and lymphocyte surface marker CD26/dipeptidyl peptidase IV (DPP IV) was found to be responsible for posttranslational processing of chemokines. Removal of NH(2)-terminal dipeptides by CD26/DPP IV alters chemokine receptor binding and signaling, and hence inflammatory and anti-human immunodeficiency virus (HIV) activities. CD26/DPP IV and CXCR3 are both markers for Th1 lymphocytes and, moreover, CD26/DPP IV is present in a soluble, active form in human plasma. This study reports that at physiologic enzyme concentrations CD26/DPP IV cleaved 50% of I-TAC within 2 minutes, whereas for IP-10 and Mig the kinetics were 3- and 10-fold slower, respectively. Processing of IP-10 and I-TAC by CD26/DPP IV resulted in reduced CXCR3-binding properties, loss of calcium-signaling capacity through CXCR3, and more than 10-fold reduced chemotactic potency. Moreover, IP-10 and I-TAC cleaved by CD26/DPP IV acted as chemotaxis antagonists and CD26/DPP IV-truncated IP-10 and Mig retained their ability to inhibit the angiogenic activity of interleukin-8 in the rabbit cornea micropocket model. These data demonstrate a negative feedback regulation by CD26/DPP IV in CXCR3-mediated chemotaxis without affecting the angiostatic potential of the CXCR3 ligands IP-10 and Mig.

Angiogenesis Inhibitors↗

Distribution of an orphan G-protein coupled receptor (JP05) mRNA in the human brain.

JP05, also called GPR72 or GIR, is an orphan G-protein-coupled receptor, GPCR, showing significant structural similarity to the tachykinin receptors. The anatomical distribution of JP05 mRNA was first described in the central nervous system of the mouse, and recently the human JP05 orphan receptor gene has been cloned. In the present study the distribution of JP05 mRNA was examined in the human forebrain using in situ hybridization analysis. The results revealed a wide but discrete distribution of the transcript with strongly JP05 mRNA expressing cells, presumably neurons, present in the cerebral cortex (layer II), hippocampus (pyramidal CA3 neurons and granule cells), amygdala (basal and periamygdaloid cortical nuclei), in the endopiriform nucleus, diagonal band of Broca, thalamus (nucleus reuniens, parafascicular nucleus) and hypothalamus (posterior, dorsal, and around the medial mammillary). Weaker signals were detected in the deeper cortical layers and throughout the striatum. A few positive cells were evident in the raphe but not in the substantia nigra or pontine nuclei. The results indicate significant similarities between human and mouse brain with regard to JP05 mRNA expression. The distribution patterns of JP05 mRNA in the human brain suggest involvement in control of emotions and of neuroendocrine, cognitive and motor functions.

Brain↗

Urokinase plasminogen activator and plasmin efficiently convert hemofiltrate CC chemokine 1 into its active.

We have previously isolated from human hemofiltrate an N-terminally truncated form of the hemofiltrate CC chemokine 1 (HCC-1), and characterized HCC-1[9-74] as a strong agonist of CCR1, CCR5, and to a lower extent CCR3. In this study, we show that conditioned media from human tumor cell lines PC-3 and 143B contain proteolytic activities that convert HCC-1 into the [9-74] form. This activity was fully inhibited by inhibitors of urokinase-type plasminogen activator (uPA), including PA inhibitor-1, an anti-uPA mAb, and amiloride. Pure preparations of uPA processed HCC-1 with high efficiency, without further degrading HCC-1[9-74]. Plasmin could also generate HCC-1[9-74], but degraded the active product as well. The kinetics of HCC-1 cleavage by uPA and plasmin (Michaelis constant, K(m), of 0.76 +/- 0.4 microM for uPA, and 0.096 +/- 0.05 microM for plasmin; catalytic rate constant, k(cat): 3.36 +/- 0.96 s(-1) for uPA and 6 +/- 3.6 s(-1) for plasmin) are fully compatible with a role in vivo. The activation of an abundant inactive precursor into a broad-spectrum chemokine by uPA and plasmin directly links the production of uPA by numerous tumors and their ability to recruit mononuclear leukocytes, without the need for the transcriptional activation of chemokine genes.

Aequorin↗

Identification of a novel human ADP receptor coupled to G(i).

We have cloned and expressed a novel human G-protein-coupled receptor closely related to the human P2Y(12) receptor. It corresponds to the orphan receptor called GPR86. GPR86 proved to be a G(i)-coupled receptor displaying a high affinity for ADP, similar to the P2Y(12) receptor and can therefore be tentatively called P2Y(13). In 1321N1 cells, the P2Y(13) receptor coupled to the phosphoinositide pathway only when coexpressed with Galpha(16). Inositol trisphosphate formation was stimulated equipotently by nanomolar concentrations of ADP and 2MeSADP, whereas 2MeSATP and ATP were inactive. In CHO-K1 cells expressing the P2Y(13) receptor, ADP and 2MeSADP had a biphasic effect on the forskolin-stimulated accumulation of cAMP: inhibition at nanomolar concentrations and potentiation at micromolar levels. In the same cells, ADP and 2MeSADP also stimulated the phosphorylation of Erk1 and Erk2, in a pertussis toxin-sensitive way. The tissue distribution of P2Y(13) was investigated by reverse transcriptase-polymerase chain reaction, and the predominant signals were obtained in spleen and brain. Although these can be discriminated by tissue distribution and some pharmacological features, the P2Y(12) and P2Y(13) receptors form a subgroup of related P2Y subtypes that is structurally different from the other P2Y subtypes but share coupling to G(i) and a high affinity for ADP.

Adenosine Diphosphate↗

HIV-1 glycoprotein 120 induces the MMP-9 cytopathogenic factor production that is abolished by inhibition of the p38 mitogen-activated protein kinase signaling pathway.

It has been previously shown that the HIV-1 envelope glycoprotein 120 (gp120) activates cell signaling by CXCR4, independently of CD4. The present study examines the involvement of different intracellular signaling pathways and their physiopathologic consequences following the CD4-independent interaction between CXCR4 or CCR5 and gp120 in different cell types: primary T cells, CD4(-)/CXCR4(+)/CCR5(+) T cells, or glioma cells. These interactions were compared with those obtained with natural ligands, stromal cell-derived factor 1 alpha (SDF-1alpha) (CXCL12) and macrophage inflammatory protein 1 beta (MIP-1beta) (CCL4) of their respective coreceptors. Thus, both p38 and SAPK/Jun N-terminal kinase mitogen-activated protein kinases (MAPKs) are activated on stimulation of these cells with either T- or M-tropic gp120, as well as with SDF-1alpha or MIP-1beta. In contrast, extracellular signal-related kinase 1 and 2 MAPKs are only activated by MIP-1beta but not by M-tropic gp120. Importantly, T- and M-tropic gp120 are able to induce the secretion of matrix metalloproteinase 9 (MMP-9), an extracellular metalloproteinase present in cerebrospinal fluid of patients with HIV-1 by T cells or glioma cells. Specific inhibition of MAPK p38 activation resulted in a complete abrogation of the induction of the MMP-9 pathogenic factor expression by gp120 or chemokines in both cell types. Because neurodegenerative features in acquired immune deficiency syndrome dementia may involve demyelinization by MMP-9, the specific targeting of p38 could provide a novel means to control HIV-induced cytopathogenic effects and cell homing to viral replication sites. (Blood. 2001;98:541-547)

Animals↗

Dual role of Fyn in the regulation of FAK+6,7 by cannabinoids in hippocampus.

In hippocampus endocannabinoids modulate synaptic function and plasticity and increase tyrosine phosphorylation of several proteins, including focal adhesion kinase (FAK). Autophosphorylation of FAK on Tyr-397 is generally a critical step for its activation, allowing the recruitment of Src family kinases, and phosphorylation of FAK and associated proteins. We have examined the mechanisms of the regulation of FAK by cannabinoids in rat and mouse hippocampal slices. Anandamide and 2-arachidonoylglycerol, two endocannabinoids, and Delta9-tetrahydrocannabinol, stimulated tyrosine phosphorylation of FAK+6,7, a neuronal splice isoform of FAK, on several residues including Tyr-397. Cannabinoids increased phosphorylation of p130-Cas, a protein associated with FAK, but had no effect on PYK2, a tyrosine kinase related to FAK and enriched in hippocampus. Pharmacological experiments and the use of knockout mice demonstrated that the effects of cannabinoids were mediated through CB1 receptors. These effects were sensitive to manipulation of cAMP-dependent protein kinase, suggesting that they were mediated by inhibition of a cAMP pathway. PP2, an Src family kinase inhibitor, prevented the effects of cannabinoids on p130-Cas and on FAK+6,7 tyrosines 577 and 925, but not 397, indicating that FAK autophosphorylation was upstream of Src family kinases in response to CB1-R stimulation. Endocannabinoids increased the association of Fyn, but not Src, with FAK+6,7. In hippocampal slices from Fyn -/- mice, the levels of p130-Cas were increased, and the effects of endocannabinoids on tyrosine phosphorylation, including of Tyr-397, were completely abolished. These results demonstrate the specific functional association of Fyn with FAK+6,7 in a pathway regulated by endocannabinoids, in which Fyn may play roles dependent and independent of its catalytic activity.

Animals↗

The metastasis suppressor gene KiSS-1 encodes kisspeptins, the natural ligands of the orphan G protein-coupled receptor GPR54.

Natural peptides displaying agonist activity on the orphan G protein-coupled receptor GPR54 were isolated from human placenta. These 54-, 14,- and 13-amino acid peptides, with a common RF-amide C terminus, derive from the product of KiSS-1, a metastasis suppressor gene for melanoma cells, and were therefore designated kisspeptins. They bound with low nanomolar affinities to rat and human GPR54 expressed in Chinese hamster ovary K1 cells and stimulated PIP(2) hydrolysis, Ca(2+) mobilization, arachidonic acid release, ERK1/2 and p38 MAP kinase phosphorylation, and stress fiber formation but inhibited cell proliferation. Human GPR54 was highly expressed in placenta, pituitary, pancreas, and spinal cord, suggesting a role in the regulation of endocrine function. Stimulation of oxytocin secretion after kisspeptin administration to rats confirmed this hypothesis.

Amino Acid Sequence↗

Structural and functional analysis of the RANTES-glycosaminoglycans interactions.

Chemokines mediate their biological activity through activation of G protein coupled receptors, but most chemokines, including RANTES, are also able to bind glycosaminoglycans (GAGs). Here, we have investigated, by site-directed mutagenesis and chemical acetylation, the role of RANTES basic residues in the interaction with GAGs using surface plasmon resonance kinetic analysis. Our results indicate that (i) RANTES exhibited selectivity in GAGs binding with highest affinity (K(d) = 32.1 nM) for heparin, (ii) RANTES uses the side chains of residues R44, K45, and R47 for heparin binding, and blocking these residues in combination abolished heparin binding. The biological relevance of RANTES-GAGs interaction was investigated in CHO-K1 cells expressing CCR5, CCR1, or CCR3 and the various GAGs that bind RANTES. Our results indicate that the heparin binding site, defined as the 40s loop, is only marginally involved in CCR5 binding and activation, but largely overlaps the CCR1 and CCR3 binding and activation domain in RANTES. In addition, enzymatic removal of cell surface GAGs by glycosidases did not affect CCR5 binding and Ca(2+) response. Furthermore, addition of soluble GAGs inhibited both CCR5 binding and functional response, with a rank of potency similar to that found in surface plasmon resonance experiments. Thus, cell surface GAGs is not a prerequisite for receptor binding or signaling, but soluble GAGs can inhibit the binding and the functional response of RANTES to CCR5 expressing cells. However, the marked selectivity of RANTES for different GAGs may serve, in vivo, to control the concentration of specific chemokines in inflammatory situations and locations.

Acetylation↗

Palmitoylation of CCR5 is critical for receptor trafficking and efficient activation of intracellular signaling pathways.

CCR5 is a CC chemokine receptor expressed on memory lymphocytes, macrophages, and dendritic cells and also constitutes the main coreceptor for macrophage-tropic (or R5) strains of human immunodeficiency viruses. In the present study, we investigated whether CCR5 was palmitoylated in its carboxyl-terminal domain by generating alanine substitution mutants for the three cysteine residues present in this region, individually or in combination. We found that wild-type CCR5 was palmitoylated, but a mutant lacking all three Cys residues was not. Through the use of green fluorescent fusion proteins and immunofluorescence studies, we found that the absence of receptor palmitoylation resulted in sequestration of CCR5 in intracellular biosynthetic compartments. By using the fluorescence recovery after photobleaching technique, we showed that the non-palmitoylated mutant had impaired diffusion properties within the endoplasmic reticulum. We next studied the ability of the mutants to bind and signal in response to chemokines. Chemokines binding and activation of G(i)-mediated signaling pathways, such as calcium mobilization and inhibition of adenylate cyclase, were not affected. However, the duration of the functional response, as measured by a microphysiometer, and the ability to increase [(35)S]guanosine 5'-3-O-(thio)triphosphate binding to membranes were severely affected for the non-palmitoylated mutant. The ability of RANTES (regulated on activation normal T cell expressed and secreted) and aminooxypentane-RANTES to promote CCR5 endocytosis was not altered by cysteine replacements. Finally, we found that the absence of receptor palmitoylation reduced the human immunodeficiency viruses coreceptor function of CCR5, but this effect was secondary to the reduction in surface expression. In conclusion, we found that palmitoylated cysteines play an important role in the intracellular trafficking of CCR5 and are likely necessary for efficient coupling of the receptor to part of its repertoire of signaling cascades.

Acylation↗

Importance of basic residues and quaternary structure in the function of MIP-1 beta: CCR5 binding and cell surface sugar interactions.

Chemokines direct immune cells toward sites of infection by establishing a gradient across the extracellular matrix of the tissue. This gradient is thought to be stabilized by ligation of chemokines to sulfated polysaccharides known as glycosaminoglycans (GAGs) that are found on the surface of endothelial and other cells as well as in the tissue matrix. GAGs interact with chemokines and in some cases cause them to aggregate. The interaction between cell surface GAGs and chemokines has also been postulated to play a role in the anti-HIV activity of some chemokines, including MIP-1beta. Since many proteins interact with GAGs by utilizing basic residues, we mutated R18, K45, R46, and K48 in MIP-1beta to investigate the role of these residues in GAG binding and CCR5 function. We find that no single amino acid substitution alone has a dramatic effect on heparin binding, although change at R46 has a moderate effect. However, binding to heparin is completely abrogated in a mutant (K45A/R46A/K48A) in which the entire "40's loop" has been neutralized. A functional study of these mutants reveals that the charged residues in this 40's loop, particularly K48 and R46, are critical mediators of MIP-1beta binding to its receptor CCR5. However, despite the partially overlapping function of the residues in the 40's loop in binding to both CCR5 and heparin, the presence of cell surface sugars does not appear to be necessary for the ability of MIP-1beta to function on its receptor CCR5, as enzymatic removal of GAGs from cells results in little effect on MIP-1beta activity. Because the means by which the chemokine gradient transmits information to the recruited cells is not well defined, we also mutated the basic residues in MIP(9), a truncated form of MIP-1beta that is impaired in its ability to dimerize, to probe whether the quaternary structure of this chemokine influences its ability to bind heparin. None of the truncated variants bound as well as the full-length proteins containing the same mutation, suggesting that the MIP-1beta dimer participates in heparin binding.

Amino Acids↗