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J Bard

Publications and source records attributed to J Bard.

At least 19 recordsLinked to original sources
PubMed1999

Odortypes: their origin and composition.

Odors that distinguish one individual from another member of the species and are determined by polymorphic genes are called odortypes. Odortypes and their considerable societal significance have been studied intimately only in mice and mainly with respect to the genes of the major histocompatibility complex. Further understanding and the matter of human relevance have been hampered by the apparent restriction of odortype expression to urine. The present finding that odorants comprising prerenal odortypes are already present in blood, albeit in masked form, affords the basis of a comprehensive view of odortypes. Accordingly, major histocompatibility complex and other polymorphic genes of antiquity are seen inter alia as agents of normal variation, which entails quantitative variation in output of odorant metabolites. Relatively few such normal variations should suffice for a vast range of compound odors whose specificity is determined by combinative assortment of the same set of individual volatile compounds.

Animals↗
PubMed1998

Molecular biology and pharmacology of multiple NPY Y5 receptor species homologs.

NPY is a 36-amino acid peptide which exerts its physiological effects through the activation of a family of G-protein coupled receptors. In vivo and in vitro characterization of the recently cloned rat Y5 receptor suggests that it is a primary mediator of NPY-induced feeding (Gerald et al., Nature 1996;382:168-171). We now report the molecular cloning and pharmacological characterization of the human, dog and mouse homologs of the Y5 receptor. With the exception of a 21 amino acid repeat in the amino terminus of the mouse Y5 receptor, the sequence of the four species homologs appear to be highly conserved, with 88% to 97% amino acid identities between any two species. Similarly, the pharmacological profiles of the four species homologs as determined in porcine 125I-PYY binding assays show a great deal of conservation, with the following rank order of affinity: human or porcine NPY, PYY, [Leu31,Pro34]NPY, NPY(2-36), human PP > human [D-Trp32]NPY > rat PP, C2-NPY. Northern blot analysis reveals that the Y5 receptor is widely distributed in the human brain, with the strongest signals detected in the cortex, putamen and caudate nucleus. The chromosomal localization of the human Y5 receptor, previously shown to be overlapping and in the opposite orientation to the Y1 receptor, is determined to be 4q31, the same locus as previously demonstrated for the human Y1 receptor (Herzog et al., J Biol Chem 1993;268:6703-6707), suggesting that these receptors may be coregulated. These Y5 species homologs along with corresponding animal models may be useful in the search for novel therapeutics in the treatment of obesity and related feeding disorders.

Amino Acid Sequence↗
PubMed1998

Cloned human and rat galanin GALR3 receptors. Pharmacology and activation of G-protein inwardly rectifying K+ channels.

The neuropeptide galanin has been implicated in the regulation of processes such as nociception, cognition, feeding behavior, and hormone secretion. Multiple galanin receptors are predicted to mediate its effects, but only two functionally coupled receptors have been reported. We now report the cloning of a third galanin receptor distinct from GALR1 and GALR2. The receptor, termed GALR3, was isolated from a rat hypothalamus cDNA library by both expression and homology cloning approaches. The rat GALR3 receptor cDNA can encode a protein of 370 amino acids with 35% and 52% identity to GALR1 and GALR2, respectively. Localization of mRNA by solution hybridization/RNase protection demonstrates that the GALR3 transcript is widely distributed, but expressed at low abundance, with the highest levels in the hypothalamus and pituitary. We also isolated the gene encoding the human homologue of GALR3. The human GALR3 receptor is 90% identical to rat GALR3 and contains 368 amino acids. Binding of porcine 125I-galanin to stably expressed rat and human GALR3 receptors is saturable (rat KD = 0.98 nM and human KD = 2.23 nM) and displaceable by galanin peptides and analogues in the following rank order: rat galanin, porcine galanin approximately M32, M35 approximately porcine galanin-(-7 to +29), galantide, human galanin > M40, galanin-(1-16) > [D-Trp2]galanin-(1-29), galanin-(3-29). This profile resembles that of the rat GALR1 and GALR2 receptors with the notable exception that human galanin, galanin-(1-16), and M40 show lower affinity at GALR3. In Xenopus oocytes, activation of rat and human GALR3 receptors co-expressed with potassium channel subunits GIRK1 and GIRK4 resulted in inward K+ currents characteristic of Gi/Go-coupled receptors. These data confirm the functional efficacy of GALR3 receptors and further suggest that GALR3 signaling pathways resemble those of GALR1 in that both can activate potassium channels linked to the regulation of neurotransmitter release.

Amino Acid Sequence↗
PubMed1998

Cloning and characterization of the human galanin GALR2 receptor.

We present the molecular cloning and characterization of the human galanin receptor, hGALR2. hGALR2 shares 85%, 39%, and 57% amino acid identities to rGALR2, hGALR1, and hGALR3, respectively. hGALR2, along with rGALR2, can be distinguished from the other cloned galanin receptors by a tolerance for both N-terminal extension and C-terminal deletion of galanin, as well as by a primary signaling mechanism involving phosphatidyl inositol hydrolysis and calcium mobilization. By RT-PCR, GALR2 mRNA was abundant in human hippocampus, hypothalamus, heart, kidney, liver, and small intestine. A weak GALR2 mRNA signal was detected in human retina, and no signal was detected in cerebral cortex, lung, spleen, stomach, or pituitary.

Amino Acid Sequence↗
PubMed1998

Functional characterization of the recombinant human 5-hydroxytryptamine7(a) receptor isoform coupled to adenylate cyclase stimulation.

Functional characterization of the recombinant human 5-hydroxytryptamine7(a) (h5-HT7(a)) receptor isoform was performed using stably transfected LM(tk-) cells. Expression levels of the h5-HT7(a) receptor determined from saturation studies using either a labeled agonist ([3H]5-HT) or antagonist ([3H]LSD) were very similar (Bmax = 160-190 fmol/mg protein), suggesting that all receptors may exist in the high affinity (G protein-coupled) state. In intact cells, 5-HT produced a concentration-dependent elevation of intracellular cAMP levels ([cAMP]i) with an EC50 value of 80 nM and a maximal response of 5-fold increase above basal levels. The rank order of agonist potencies in the second messenger assay paralleled their rank order of binding affinities: 5-carboxamidotryptamine > 5-hydroxytryptamine >/= 5-methoxytryptamine > 8-hydroxy N,N-dipropyl aminotetralin > sumatriptan. Agonist potencies (EC50 values) to stimulate [cAMP]i were more than 25-fold lower relative to their respective binding affinities (Ki values) obtained in [3H]5-HT competition assays. In contrast, antagonist potencies (Kb values) to block 5-HT-stimulated [cAMP]i were in close agreement with their corresponding Ki values. These data may indicate low efficiency of receptor-effector coupling to adenylate cyclase stimulation. Pretreatment of stably transfected cells with cholera toxin abolished the 5-HT-mediated elevation of [cAMP]i, indicating that the 5-HT7(a) subtype directly interacts with Galphas protein(s) to activate adenylate cyclase(s). Clonal cell lines stably expressing h5-HT7 receptor isoforms will serve as valuable cellular models to study their function and regulation, as well as assist in the development of selective 5-HT7 receptor agents to uncover the biological roles and potential therapeutic applications of this novel receptor subtype.

Adenylyl Cyclases↗
PubMed1997

Expression cloning of a rat hypothalamic galanin receptor coupled to phosphoinositide turnover.

The neuropeptide galanin is widely distributed throughout the central and peripheral nervous systems and participates in the regulation of processes such as nociception, cognition, feeding behavior, and insulin secretion. Multiple galanin receptors are predicted to underlie its physiological effects. We now report the isolation by expression cloning of a rat galanin receptor cDNA distinct from GALR1. The receptor, termed GALR2, was isolated from a rat hypothalamus cDNA library using a 125I-porcine galanin (125I-pGAL) binding assay. The GALR2 cDNA encoded a protein of 372 amino acids exhibiting 38% amino acid identity with rat GALR1. Binding of 125I-pGAL to transiently expressed GALR2 receptors was saturable (KD = 0.15 nM) and displaceable by galanin peptides and analogues in rank order: porcine galanin approximately M32 approximately M35 approximately M40 >/= galanin-(1-16) approximately M15 approximately [D-Trp2]galanin-(1-29) > C7 >> galanin-(3-29). This profile resembles that of the rat GALR1 receptor with the notable exception that [D-Trp2]galanin exhibited significant selectivity for GALR2 over GALR1. Activation of GALR2 receptors with porcine galanin and other galanin analogues increased inositol phospholipid turnover and intracellular calcium levels in stably transfected Chinese hamster ovary cells and generated calcium-activated chloride currents in Xenopus oocytes, suggesting that the rat GALR2 receptor is primarily coupled to the activation of phospholipase C.

Amino Acid Sequence↗
PubMed1997

Oligonucleotide-mediated inhibition of CD28 expression induces human T cell hyporesponsiveness and manifests impaired contact hypersensitivity in mice.

Ligation of CD28 provides a costimulatory signal essential for Ag-mediated T cell activation via the TCR. Blocking CD28 ligation can inhibit cytokine expression and elicits a state of T cell hyporesponsiveness. In this study, we examined the effect of inhibiting CD28 expression on in vitro and in vivo T cell responses. To address this, we have synthesized a series of G-rich phosphorothioate oligonucleotides that inhibited activation-induced transcription and cell surface expression of CD28 on human T cells. CD28 blockade was selective, as expression of other activation-induced receptors was unaffected by oligonucleotide treatment. Using strategic changes to base composition, we identified a minimal 12-mer sequence, containing two sets of four contiguous guanosines separated by 3 to 5 bases, which conferred activity in vitro. Furthermore, inhibition of CD28 expression mediated by one representative active oligonucleotide, GR1, resulted in a concomitant dose-dependent diminution of anti-CD3/PMA-induced cytokine (IL-2, IFN-gamma, IL-8) production. Inhibition of IL-2 synthesis was dependent on CD28 expression, as GR1 failed to abrogate activated IL-2 production in a CD28-deficient T cell line, HUT 78. The inhibitory activity of GR1 reduced T cell proliferative responses in MLR and induced Ag-specific T cell hyporesponsiveness to alloantigens. Finally, s.c. administration of GR1 impaired in vivo contact hypersensitivity responses in mice and was associated with substantially decreased CD28 and IFN-gamma mRNA expression in lymph node cells. Collectively, our studies show the tolerogenic potential of oligonucleotide-mediated CD28 inhibition on T cell activation, in vitro and in vivo.

Animals↗
PubMed1997

The mouse atlas and graphical gene-expression database

The large amounts of gene-expression data on mouse development are now too extensive to be stored in any format other than that of a database. Furthermore, as this data is intrinsically graphical and as, in the early developmental stages at least, its boundaries do not map directly to those of anatomical tissues, the natural way to store it is in graphical format. We are therefore constructing a database able to handle such graphical gene-expression data by mapping it onto 3-D reconstructions of mouse embryos whose tissues have been delineated. This article reviews the progress that has been made in this project and describes its two major components, CD-ROMs of the 3-D reconstructions to be held on the user's computer and a gene-expression database that will be maintained at a host site, the two being linked over the internet by a complex Java-based interface for submitting data and querying the database.Copyright 1997 Academic Press Limited Copyright 1997Academic Press Limited

Journal Article↗
PubMed1997

A structure-activity analysis of the cloned rat and human Y4 receptors for pancreatic polypeptide.

We cloned and expressed the rat Y4 receptor for pancreatic polypeptide (PP). Structure-activity profiles derived from 125I-PP binding assays and [cAMP] radioimmunoassays reveal a selective receptor interaction with rat PP vs. neuropeptide Y (NPY) or peptide YY (PYY). Rat and human Y4 receptor clones share 75% amino acid identity. Based on [cAMP] radioimmunoassay, the human Y4 receptor exhibits a less selective interaction with rat PP vs. NPY or PYY and a greater dependence on N-terminal PP residues, relative to rat Y4. Differences in sequence and structure-activity profiles suggest the rat be used with caution to model human Y4 receptor function.

Animals↗
PubMed1997

Oligonucleotide biological activity: relationship to the cell cycle and nuclear transport.

Previous studies suggest that oligodeoxynucleotide (ODN) cellular uptake is cell cycle-dependent which may have important implications in cancer cell targeting. To further our understanding of ODN transport and activity, this study examines the relationships between the cell cycle, ODN cellular uptake, intracellular transport, and activity. An antisense c-myc ODN 21-mer was used to study ODN cellular uptake in Rauscher erythroleukemia cells synchronized by either chemical methods or flow cytometry. ODN uptake was examined using subcellular fractionation and confocal fluorescence microscopy. Western blot analysis was used to measure ODN-mediated decreases in c-myc protein levels. Intracellular ODN distribution and extent of uptake was influenced by the phase of the cell cycle, but the mechanism of uptake was not. The relative activity of the antisense ODN was positively correlated to ODN distribution to the cytosol, but negatively correlated to total cellular uptake. Although ODN total cellular uptake is positively influenced by the cell cycle, retention of the ODN in the cytosol (presumably extra-vesicularly) appeared to be relevant in determining the activity of an antisense ODN. Novel methods to target cytosol-acting drugs to the cytoplasm may therefore be warranted.

Biological Transport↗
PubMed1996

A new role for the stromal cells in kidney development.

New observations by Hatini et al. on the 'winged helix' transcription factor BF-2 will make us change our views about kidney development. This gene is only expressed in stromal cells associated with the kidney medulla and cortex, but the BF-2 knockout has unexpected abnormalities. Although the stromal cells appear normal, the kidney is small, the ducts have limited branching and, instead of the many normal nephrogenic aggregates, there are relatively few large mesenchymal aggregates that fail to differentiate. The stromal cells thus seem to produce factors regulating other aspects of kidney development, while the abnormalities highlight a series of unsolved problems in kidney morphogenesis.

Animals↗
PubMed1995

Evidence suggesting that the odortypes of pregnant women are a compound of maternal and fetal odortypes.

Odortypes--namely, body odors that distinguish one individual from another on the basis of genetic polymorphism at the major histocompatibility complex and other loci--are a fundamental element in the social life and reproductive behavior of the mouse, including familial imprinting, mate choice, and control of early pregnancy. Odortypes are strongly represented in urine. During mouse pregnancy, an outcrossed mother's urine acquires fetal major histocompatibility complex odortypes of paternal origin, an observation that we took as the focus of a search for odortypes in humans, using a fully automated computer-programmed olfactometer in which trained rats are known to distinguish precisely the odortypes of another species. Five women provided urine samples before and after birth, which in each case appropriately trained rats were found to distinguish in the olfactometer. Whether this olfactory distinction of mothers' urine before and after birth reflects in part the odortype and hence genotype of the fetus, and not just the state of pregnancy per se, was tested in a second study in which each mother's postpartum urine was mixed either with urine from her own infant or with urine of a different, same-aged infant. Responses of trained rats were more positive with respect to the former (congruous) mixtures than to the latter (incongruous) mixtures, implying that, as in the mouse, human fetal odortypes of paternal genomic origin are represented in the odortype of the mother, doubtless by circulatory transfer of the pertinent odorants.

Animals↗
PubMed1994

Discrimination of odortypes determined by the major histocompatibility complex among outbred mice.

Genetically determined body odors that distinguish one mouse from another are termed odortypes. The best known odortypes, highly expressed in urine, are those specified by H-2, the major histocompatibility complex of the mouse, but other odortypes originate from unidentified loci in the rest of the genome, including both sex chromosomes. The definition of H-2 odortypes and evidence that their perception affects reproductive behavior have so far depended on studies with inbred mouse strains whose genetic differences are confined to the H-2 complex of genes. To simulate feral conditions more closely, a freely segregating population was bred from crosses involving four unrelated inbred strains contributing four different H-2 haplotypes. After H-2 typing, this outbred population was divided into four groups of freely segregating mice, comprising the four distinct H-2 genotypes represented, to serve as conventional donors of urine for evaluation in the standard Y-maze system used in the training and testing of mice for H-2 odortype discrimination. With respect to utility in training mice for H-2 odortype discrimination, and to degrees of concordance attained in the Y-maze by trained mice, these urinary H-2 odortype sources from outbred mice were no less effective than urines customarily obtained for those purposes from nonsegregating inbred donors. We conclude that discrimination of H-2 odortypes is not appreciably affected or impaired by the usual concurrent segregation within the genome as a whole.

Animals↗
PubMed1994

Fetal H-2 odortypes are evident in the urine of pregnant female mice.

The major histocompatibility complex (MHC) imparts to each mouse an individual urinary odor, called "odortype", which reflects its MHC genotype. Perception of odortypes affects mate selection and embryonic implantation. Recent findings that odortypes are expressed as early as one day of age suggested that they might already be expressed in utero. We now report that at 9-12 days of gestation, odortypes specified by paternal (non-maternal) MHC haplotypes become apparent in maternal urine. Thus, odortypes are expressed in utero, can be sensed even before birth, and may serve in familial identification and communication.

Animals↗
PubMed1994

Immunoreactivity of umbilical cord blood and post-partum maternal peripheral blood with regard to HLA-haploidentical transplantation.

Recent clinical reports have demonstrated that umbilical cord blood (CB) may be utilized as a source of transplantable hematopoietic stem cells when bone marrow is not available. However, it is not apparent that CB can be used to transplant partially HLA-matched siblings or matched, non-familial recipients. In this study the immunoreactivity of CB has been investigated within familial confines; 14 families were analyzed at the time of birth of their child and six of these families were reassessed at 6 months post-partum. In mixed lymphocyte reactions, CB was unable to significantly respond to stimulation with cells from either the mother or father. Furthermore, unlike adult peripheral blood, CB displayed depressed immune responses to alloantigen and T cell mitogen. At 6 months, the immune responses of the infant demonstrated normal development in terms of alloantigen and mitogen responses. However, at 6 months both the mother and the infant demonstrated a continued immune tolerance to one another. The data suggest that CB could be used in familial transplant situations when siblings are HLA-haploidentical if the donor/recipients are chosen based on the paternal haplotype. Furthermore, maternal bone marrow harvested during the 6 months immediately following delivery of a child also should be suitable as a stem cell graft in haploidentical situations.

Cytotoxicity, Immunologic↗